AU714209B2 - Method of cancer treatment by p53 protein control - Google Patents

Description

p. WO 95/33060 1 PCT/FR95/00670 METHOD OF TREATING CANCER BY REGULATION OF THE P53

PROTEIN

The present invention relates to a new method for the treatment of cancer. More particularly, it relates to a method of treating cancer by regulating the cellular levels of the p53 protein. It also relates to vectors for gene therapy which make it possible to regulate the p53 protein, as well as the pharmaceutical compositions containing them.

For the past fifteen years, the molecular characterization of oncogenes and of tumour suppressor genes has made it possible to view the process of carcinogenesis in a new light. Thus, the increasingly detailed knowledge of the regulation of these genes and of the function of the corresponding proteins makes it possible to conceive new therapeutic approaches.

More particularly, the elucidation of the breakdown of the oncogenic and anti-oncogenic proteins represents a major challenge in terms of the fight against cancer since it presages, in the case of oncogenic proteins, the possibility of accelerating their degradation and therefore of annihilating their action, in the case of tumour suppressors, inhibiting their degradation and therefore increasing their antiproliferative or anti-tumour effect, in the case of mutated proteins, potentiating their antigenic presentation by molecules of the Major 2 Histocompatibility Complex and thereby stimulating a tumour-specific immune response, and, in the case where the high expression of the oncogene or of the antioncogene is capable of inducing programmed cell death, the possibility of stabilizing these proteins so as to trigger the apoptotic process.

Originally, the p53 protein was classified as a nuclear oncogene since it could, in transfection experiments, extend the life of rodent cells in culture as well as cooperate with activated oncogenes such as ras to transform cells in primary culture. Indeed, the genes used in these first experiments were mutated and led to the expression of variant p53 proteins characterized by a gain in function. Without excluding functions which might still be discovered, it is now known that the p53 protein, at least in its wild-type form, is a transcription factor which negatively regulates growth and cell division and which, in certain situations, is capable of inducing apoptosis (Yonish-Rouach et al., Nature, 352, 345-347, 1991).

Given that these properties manifest themselves in a stress situation where the integrity of the cellular DNA is threatened, it has been suggested that p 53 is a "guardian of the genome". The presence of mutated p53 proteins in about 40 of human tumours, all types taken together, reinforces this hypothesis and underlines the probably critical role which mutations of this gene play in the tumour development (for r reviews, see Montenarh, Oncogene, 7, 1673-1680, 1992; Oren, FASEB 6, 3169-3176, 1992; Zambetti and Levine, FASEB 7, 855-865, 1993).

The wild-type p53 protein is subject to a complex regulation which involves the control of its synthesis and of its breakdown as well as that of its intracellular location and of its post translational modifications (see the reviews cited above). The wildtype p53 protein is extremely unstable with a half-life of a few minutes. In contrast, some mutated proteins which accumulate at a high level in tumours have a significantly extended half-life. Little has been clearly established as regards the degradation of p53.

Indeed, neither the intracellular sites of degradation, nor the number and the nature of the catabolic pathways taken, nor the peptide units labelling p53 for its degradation are known. To our knowledge, the only information available relates to the involvement of the enzyme El of the ubiquitin cycle under certain experimental conditions (Ciechanover et al., Proc.

Natl. Acad. Sci. USA 88, 139-143, 1991; Chowdary et al., Molec. Cell. Biol. 14, 1997-2003, 1994). Moreover, it has been shown that certain proteolytic products derived from p53 may be presented in an antigenic manner.

The present invention results partly from the demonstration that the p53 proteins are substrates for calcium-dependent proteases: the calpains. It results Q:\OPER\EJH\IPEA.307 3/11/99 -4more particularly from the demonstration that the p53 proteins are degraded specifically by m-calpain or u-calpain. This is the first demonstration of a mechanism for regulating the cellular levels of the p53 proteins and thus offers a new particularly effective and specific approach for modulating the levels of this protein in pathological situations such as especially certain cancers.

The new approach allows the treatment of cancer based on the use of compounds which modulate the activity of calpains on the p53 proteins, which make it possible either to activate the degradation of the mutated p53 proteins, in order to block their tumorigenic effect and/or to enhance the presentation of immunogenic peptides, or to stabilize the wild-type p53 protein, in order to counterbalance the tumorigenic effect of the mutated proteins expressed in the tumours and/or in order to induce the apoptosis of the tumour cells.

The invention thus provides use of a compound capable of modulating the activity of calpain for the preparation of a pharmaceutical composition for a method of treatment by regulating the cellular levels of the p53 protein. Typically the treatment is of a cancer. The invention provides a method of treating by regulating the cellular levels of the p53 protein comprising administering the compound.

C C 20 Calpains are ubiquitous enzymes found in most mammalian cells (for a review, see Croall and *deMartino, Physiol. Rev., 71,813-847, 1991). They are deMartino, Physiol. Rev., 71, 813-847, 1991). They are C CC Q:\OPER\EJH\IPEA.307 3/11/99 essentially cytoplasmic but they can penetrate into the nucleus by virtue of the destruction of the nuclear envelope during mitosis or following certain stimuli. As indicated above, the proteolytic activity of calpains is dependent on the presence of calcium.

The compounds capable of modulating the activity of calpain may be of several types.

Typically the compound is a protein or a polypeptide which is an inhibitor of the activity of calpain, or a nucleic acid sequence encoding such a polypeptide or protein.

The compounds may be capable of inhibiting the activity of the calpain on the p53 proteins.

These compounds are particulary advantageous since they can be used to inhibit, at least in part, the degradation of the wild-type p53 protein. Thus typically the compound is a protein or a polypeptide which is a specific inhibitor of the activity of calpain on the wild-type p53 protein, or a nucleic acid sequence encoding such a polypeptide or protein. These compounds therefore make it possible to stabilize intracellularly the wild-type p53 protein and to counterbalance the effect of the mutated forms. Among the inhibitory compounds which can be used there may be mentioned the protease inhibitors (leupeptin, aprotinin or PMSF), the calcium chelators (EGTA or EDTA) or more specific inhibitors such as calpastatin or any fragment or derivative thereof. Calpastatin is a known inhibitor of the calpains. Its sequence has been described in the prior art (SEQ ID No. A particularly advantageous embodiment 20 of the present invention consists in transferring into the tumours a vector carrying all or part of the sequence encoding calpastatin. This approach is particularly adapted to the treatment of 6 cancers which always have a wild-type p53 allele, such as colic or bronchial carcinomas for example. Various fragments or derivatives of calpastatin can be used within the framework of the present invention. Such fragments or derivatives may be any molecule obtained from the sequence SEQ ID No. 1 by modification(s) of a genetic and/or chemical nature, preserving the capacity to inhibit, at least in part, the activity of a calpain. Modification of a genetic and/or chemical nature is understood to mean any mutation, deletion, substitution, addition and/or modification of one or more nucleotides. Such modifications may be carried out with various ends, especially that of preparing sequences adapted to expression in a specific type of vector or host, that of reducing the size of the sequence so as to facilitate their cellular penetration, that of increasing the inhibitory activity, or, in a particularly advantageous manner, of increasing the selectivity of the inhibitor towards the activity of the calpains on the degradation of the wild-type p53 protein.

Such modifications may be carried out, for example, by in vitro mutagenesis, by introduction of additional constituents or of synthetic sequences, or by deletions or substitutions of the original constituents. When a derivative as defined above is prepared, its activity as inhibitor of the activity of the calpains on p53 proteins can be demonstrated in Q:\OPER\EJH\IPEA.307 3/11/99 -7several ways, and in particular by bringing into contact the said inhibitor and the various forms of p53 proteins, and then by detecting the degradation products obtained (see Examples 1 to Any other techniques known to persons skilled in the art can obviously be used to this effect.

In one embodiment all or part of calpastatin, or a nucleic acid encoding all or part of calpastatin is used as inhibitor. Still more particularly, a peptide or nucleic acid comprising all or part of the sequence SEQ ID No. 1 or of a derivative thereof is used.

As regards the derivatives, there may be mentioned, by way of example, the compound of sequence ID No. 2, which corresponds to fragment of calpastain. There is advantageously used any derivative composed of the sequence SEQ ID No. 1 or 2 which is capable of specifically or preferentially inhibiting the degradation of the wild-type p53 protein by calpain.

In one embodiment a nucleic acid with the sequence of SEQ ID No. 1 or 2 is used.

9* 4 The compounds capable of modulating the activity of calpain on the p53 proteins may also be derivative of calpain capable of specifically or preferentially degrading the mutated p53 20 proteins. Such derivatives are also very advantageous since they make it possible to activate the degradation of the mutated p53 proteins, in order to block their tumorigenic 4* *t 4 4 effect and/or to increase the presentation of the immunogenic peptides, without significantly affecting the cellular levels of the wild-type p53 protein. Such derivatives may be obtained from calpain, by structural modification(s) of a genetic and/or chemical nature.

The capacity of the derivatives thus obtained to specifically or preferentially degrade the mutated p53 proteins may then be demonstrated as described in Examples 1 to 3.

Preferably, the modulators used within the framework of the invention are proteins or polypeptides, or nucleic acid sequences encoding these polypeptides or proteins. Still more preferably, the modulatory compounds are proteins or polypeptides which are specific inhibitors of the activity of calpain on the wild-type p53 protein or forms of calpains, modified or otherwise, for specifically degrading the mutated p53 proteins.

In a particularly advantageous manner, the invention consists in the possibility of bringing about the expression in cancer cells having both a wild-type p53 allele and a mutated p53 allele of nucleic sequences encoding inhibitors of calpain, such as calpastatin or part of calpastatin, or forms of calpains, modified or otherwise, for specifically degrading the mutated p53 proteins.

The nucleic acid sequence used within the framework of the present invention may be administered Q:\OPER\EJH\IPEA.307 3/11/99 -9as such, in the form of naked DNA according to the technique described in Application W090/11092. It can also be administered in a form complexed, for example, with DEAEdextran (Pagano et al., J. Virol. 1 (1967) 891), with nuclear proteins (Kaneda et al., Science 243 (1989) 375), with lipids (Felger et al., PNAS 84 (1987) 7413 or in the formof liposomes (Fraley et al., J Biol, Chem. 255 (1980) 10431). Preferably, the nucleic acid is part of a vector. The use of such a vector indeed makes it possible to improve the administration of the nucleic acid into the cells to be treated, and also to increase its stability in the said cells.

Which makes it possible to obtain a lasting therapeutic effect.

Further more, it is possible to introduce several nucleic acid sequences into the same vector, which also increases the efficiency of the treatment.

The vector used may be of various origin, as long as it is capable of transforming animal cells, preferably human cancer cells. Typically the nucleic acid is part of a lipid liposomal vector. In a preferred embodiment a viral vector is used which may be chosen from adenoviruses, retroviruses, adeno-associated viruses (AAV) or the herpes virus.

In this regard, the subject of the present invention is any recombinant virus comprising, *o 0 J inserted into its genome, a nucleic acid encoding a compound capable of modulating the 20 activity of calpain when used in a method of treatment by regulating the cellular levels of the p53 protein.

0 e Preferably, the viruses used within the framework of the invention are defective, that is to say that they are incapable of replicating autonomously in the infected cell. Generally, the genome of the defective viruses used within the framework of the present invention therefore lacks at least the sequences necessary for the replication of the said virus in the infected cell. These regions may be either removed (completely or in part), or made nonfunctional, or substituted by other sequences and especially by the sequence encoding the modulator of the calpains.

Preferably, the defective virus retains, nevertheless, the sequences of its genome which are necessary for the encapsidation of the viral particles.

As regards more particularly adenoviruses, various serotypes, whose structure and properties vary somewhat, have been characterized. Among these serotypes, the use of the type 2 or 5 human adenoviruses (Ad 2 or Ad 5) or of the adenoviruses of animal origin (see application FR 93 05954) is preferred within the framework of the present invention. Among the adenoviruses of animal origin which can be used within the framework of the present invention, there may be mentioned adenoviruses of canine, bovine, murine (example: MVA1, Beard et al., Virology 75 (1990) 81), ovine, porcine, avian or alternatively simian (example: SAV) origin. Preferably, the adenovirus of animal origin is a canine adenovirus, or more preferably a CAV2 adenovirus [Manhattan strain or A26/61 (ATCC VR-800) for example]. Preferably, adenoviruses of human or canine or mixed origin are used within the framework of the invention.

Preferably, the defective adenoviruses of the invention comprise the ITRs, a sequence allowing the encapsidation and the sequence encoding the modulator of the calpains. Still more preferably, in the genome of the adenoviruses of the invention, the El gene and at least one of the genes E2, E4, L1-L5 are nonfunctional. The viral gene considered can be rendered non-functional by any technique known to persons skilled in the art, and especially by total suppression, by substitution or partial deletion, or by addition of one or more bases in the gene(s) considered. Such modifications can be obtained in vitro (on the isolated DNA) or in situ, for example by means of genetic engineering techniques, or alternatively by treating with mutagenic agents.

The defective recombinant adenoviruses according to the invention can be prepared by any technique known to persons skilled in the art (Levrero et al., Gene 101 (1991) 195, EP 185 573; Graham, EMBO J. 3 (1984) 2917). In particular, they can be prepared by homologous recombination between an adenovirus and a plasmid carrying, inter alia, the DNA sequence encoding the modulator of the calpains. The homologous recombination occurs after co-transfection of the said adenoviruses and plasmid into an appropriate cell line. The cell line used should preferably be transformable by the said elements, and (ii) contain the sequences capable of complementing the defective adenovirus genome part, preferably in integrated form in order to avoid risks of recombination. As an example of a cell line, there may be mentioned the human embryonic kidney line 293 (Graham et al., J. Gen. Virol. 36 (1977) 59) which contains especially, integrated in its genome, the left hand part of the genome of an Ad5 adenovirus (12 Strategies for constructing vectors derived from adenoviruses have also been described in Applications Nos. FR 93 05954 and FR 93 08596.

Next, the adenoviruses which have multiplied are recovered and purified according to conventional molecular biology techniques as illustrated in the examples.

As regards the adeno-associated viruses (AAV), they are relatively small DNA viruses which become integrated into the genome of the cells which they infect, in a stable and site-specific manner. They are capable of infecting a broad spectrum of cells, without inducing any effect on cell growth, morphology or differentiation. Moreover, they do not seem to be involved in pathologies in man. The genome of the AAVs has been cloned, sequenced and characterized. It k comprises about 4700 bases and contains, at each end, an inverted repeat region (ITR) of about 145 bases which serves as replication origin for the virus. The remainder of the genome is divided into 2 essential regions carrying the encapsidation functions: the left hand part of the genome, which contains the rep gene involved in the viral replication and the expression of the viral genes; the right hand part of the genome, which contains the cap gene encoding the virus capsid proteins.

The use of vectors derived from AAVs for the transfer of genes in vitro and in vivo has been described in the literature (see especially WO 91/18088; WO 93/09239; US 4,797,368, US 5,139,941, EP 488 528). These applications describe various constructs derived from AAVs, from which the rep and/or cap genes are deleted and replaced by a gene of interest, and their use for the transfer in vitro (on cells in culture) or in vivo (directly in an organism) of the said gene of interest. The defective recombinant AAVs according to the invention can be prepared by co-transfection, into a cell line infected by a human helper virus (for example an adenovirus), of a plasmid containing the sequence encoding the modulator of the calpains bordered by two AAV inverted repeat regions (ITR), and of a plasmid carrying the AAV encapsidation genes (rep and cap genes). The recombinant AAVs produced are then purified by conventional techniques.

As regards the herpes viruses and the retroviruses, the construction of recombinant vectors has been widely described in the literature: see especially Breakfield et al., New Biologist 3 (1991) 203; EP 453242, EP 178220, Bernstein et al. Genet. Eng.

7 (1985) 235; McCormick, BioTechnology 3 (1985) 689, and the like.

For carrying out the present invention, it is most particularly advantageous to use a defective recombinant retrovirus or adenovirus. These vectors indeed have particularly advantageous properties for the transfer of genes into tumour cells.

Advantageously, in the vectors of the invention, the sequence encoding the modulator of the calpains is placed under the control of signals allowing its expression in tumour cells. Preferably, these are heterologous expression signals, that is to say signals different from those which are naturally responsible for the expression of the modulator. They may be in particular sequences responsible for the expression of other proteins, or synthetic sequences.

In particular, they may be promoter sequences of eukaryotic or viral genes. For example, they may be promoter sequences derived from the genome of the cell which it is desired to infect. Likewise, they may be promoter sequences derived from the genome of a virus, including the virus used. In this regard, the E1A, MLP, CMV, RSV-LTR promoters and the like may be mentioned for example. In addition, these expression sequences Q:\OPER\EJH\IPEA.307 3/11/99 may be modified by addition of activating or regulatory sequences or of sequences allowing a tissue-specific expression. It may indeed be particularly advantageous to use expression signals which are active specifically or predominantly in tumour cells, so that the DNA sequence is expressed or produces its effect only when the virus has effectively infected a tumour cell.

In a specific embodiment, the invention relates to a defective recombinant virus comprising a cDNA sequence encoding a modulator of the calpains under the control of a viral promoter, preferably chosen from the RSV-LTR and CMV promoter.

Still in a preferred embodiment, the invention relates to a defective recombinant virus comprising a DNA sequence encoding a modulator of the calpains under the control of a promoter allowing predominant expression in tumour cells.

The expression is considered to be predominant for the purpose of the invention when, even if a residual expression is observed in other cell types, the expression levels are greater in the tumour cells.

S.*

S

S The present invention also relates to any pharmaceutical composition comprising one or more o 20 defective recombinant viruses as described above and a pharmaceutically acceptable carrier or diluent when used in a method of treatment by regulating the cellular levels of the p53 :protein. These pharmaceutical compositions may be formulated for administrations via the topical, oral, parenteral, intranasal, intravenous, intramuscular, subcutaneous, *S25e Soo 16 intraocular or transdermal route and the like.

Preferably, the pharmaceutical compositions of the invention contain a vehicle pharmaceutically acceptable for an injectable formulation, especially for a direct injection into the patient's tumour. This may be in particular isotonic sterile solutions, or dry, especially freeze-dried, conpositions which, upon addition, depending on the case, of sterile water or of physiological saline, allow the preparation of injectable solutions. Direct injection into the patient's tumour is advantageous because it makes it possible to concentrate the therapeutic effect at the level of the affected tissues.

The doses of defective recombinant virus which are used for the injection may be adapted according to various parameters, and especially according to the viral vector, the mode of administration used, the relevant pathology or alternatively the desired duration of the treatment. In general, the recombinant adenoviruses according to the invention are formulated and administered in the form of doses of between 10 4 to 1014 pfu/ml, and preferably 106 to 1010 pfu/ml. The term pfu ("plaque forming unit") corresponds to the infectivity of a virus solution, and is determined by infecting an appropriate cell culture and measuring, generally after 48 hours, the number of plaques of infected cells. The techniques for determining the pfu titre of a viral solution are well documented in the literature. As regards the retroviruses, the compositions according to the invention may directly comprise the producing cells, for their implantation.

The present invention is particularly adapted to the treatment of cancers in which the mutated forms of p53 are observed. More specifically, the present invention is particularly advantageous for the treatment of cancers in which the wild-type and mutated alleles of p53 are present. Such cancers are especially colorectal cancer, breast cancer, lung cancer, gastric cancer, oesophageal cancer, B lymphomas, ovarian cancer, cancer of the bladder and the like.

The present invention will be more fully described with the aid of the following Examples which should be considered as illustrative and nonlimiting.

Legend to the Fiqures Figure 1: Study of the regulation of the p53 protein by calpain. The reaction is carried out in a final volume of 30 l1, of which 1 comes from the translation mixture. Line 1: TO; line 2: 30 min in the presence of 1 mM Calcium 20 Ag/ml Calpain; line 4: 30 min in the presence of 1 mM Calcium 20 Ag/ml Calpain 0.5 mg/ml calpastatin; line 5: 30 min in the presence of 1 mM Calcium 20 Ag/ml Calpain 10 mM EGTA; line 6: PBS; line 7: PBS calcium; line 8: PBS calpastatin.

General molecular biology techniques The methods conventionally used in molecular biology, such as preparative extractions of plasmid DNA, centrifugation of plasmid DNA in caesium chloride gradient, agarose or acrylamide gel electrophoresis, purification of DNA fragments by electroelution, phenol or phenol-chloroform extraction of proteins, ethanol or isopropanol precipitation of DNA in saline medium, transformation in Escherichia coli and the like, are well known to persons skilled in the art and are widely described in the literature [Maniatis T. et al., "Molecular Cloning, a Laboratory Manual", Cold Spring Harbor Laboratory, Cold Spring Harbor, 1982; Ausubel F.M. et al. (eds), "Current Protocols in Molecular Biology", John Wiley Sons, New York, 1987].

The pBR322 and pUC type plasmids and the phages of the M13 series are of commercial origin (Bethesda Research Laboratories).

For the ligations, the DNA fragments can be separated according to their size by agarose or acrylamide gel electrophoresis, extracted with phenol or with a phenol/chloroform mixture, precipitated with ethanol and then incubated in the presence of phage T4 DNA ligase (Biolabs) according to the recommendations of the supplier.

The filling of the protruding 5' ends can be performed with the Klenow fragment of E. coli DNA polymerase I (Biolabs) according to the specifications of the supplier. The destruction of the protruding 3' ends is performed in the presence of phage T4 DNA polymerase (Biolabs) used according to the recommendations of the manufacturer. The destruction of the protruding 5' ends is performed by a controlled treatment with S1 nuclease.

Site-directed mutagenesis in vitro by synthetic oligodeoxynucleotides can be performed according to the method developed by Taylor et al.

[Nucleic Acids Res. 13 (1985) 8749-8764] using the kit distributed by Amersham.

The enzymatic amplification of the DNA fragments by the so-called PCR technique [Polymerasecatalyzed Chain Reaction, Saiki R.K. et al., Science 230 (1985) 1350-1354; Mullis K.B. and Faloona F.A., Meth. Enzym. 155 (1987) 335-350] can be performed using a DNA thermal cycler (Perkin Elmer Cetus) according to the specifications of the manufacturer.

The verification of the nucleotide sequences can be performed by the method developed by Sanger et al. [Proc. Natl. Acad. Sci. USA, 74 (1977) 5463- 5467] using the kit distributed by Amersham.

Examples Example 1 This example shows that the addition of m-calpain to rabbit reticulocyte lysate induces the degradation of the wild-type p53 protein as well as that of certain mutated forms. This example also shows that inhibitors of calpains are capable of inhibiting the degradation of p53 and therefore of modulating the activity of this protein.

1.1. Demonstration of the degradation: mouse and human wild-type p53 proteins as well as various mutated p53 proteins (human proteins C273, H273, H175, 1247) were translated in the rabbit reticulocyte lysate. The proteins thus obtained are resistant to any degradation, even in the presence of a high concentration of calcium (cofactor essential for the calpains). The addition of bovine m-calpain (Sigma) to the reticulocyte lysate in the presence of calcium led to the rapid disappearance of the neosynthesized proteins and the appearance of proteolytic fragments which are resolvable by electrophoresis. The degradation resistance of other proteins such as dihydrofolate reductase or glyceraldehyde-3-phosphate dehydrogenase under the same experimental conditions indicates the substrate specificity of the reaction.

1.2. Use of inhibitors of calpain for modulating the levels of p53 proteins: in the above Example it was shown that the addition of m-calpain induced degradation of the p53 proteins. In this example, in addition to m-calpain, various compounds were introduced into the medium in order to test their capacity to inhibit the activity of calpain.

The results obtained show that the addition of a calcium chelator (EGTA) as well as of a peptide which is a specific inhibitor of the calpains (derivative of a physiological inhibitor, calpastatin; Maki et al., J.

Biol. Chem., 254, 18866-18869, 1989) are capable of inhibiting the degradation of the p53 proteins which is induced by the exogenous calpain.

Example 2 In the preceding example, it was shown that the addition of exogenous calpain to a solution of p53 proteins brought about their degradation. This example shows that the degradation of the wild-type p53 protein as well as that of certain mutated forms may be induced by the endogenous calpains in cytoplasmic extracts.

This example also shows that inhibitors of the calpains are capable, in the presence of endogenous calpain, of inhibiting the degradation of p53 and therefore of modulating the activity of this protein.

2.1. Degradation by the endogenous calpains: mouse and human wild-type p53 proteins, as well as certain mutated forms (cf Example 1) were translated in the reticulocyte lysate and were then incubated in the presence of cytoplasmic extracts of Daudi or Jurkat human lymphoblastoid cells. The cytoplasmic extracts were prepared in the following manner: the cells (available at the ATCC) were cultured in DMEM medium supplemented with 10 foetal calf serum. The cells were then harvested, washed in PBS buffer and then incubated for 5 min in a detergent-free hypotonic lysis buffer (HEPES 20 mM, pH 7.5; KOAc 10 mM; MgOAc 1.5 mM; 2 ml per 5 x 108 cells). The lysis was completed using a Dounce homogenizer and then checked under a microscope. The nuclei were then removed by centrifugation at 2000 g for 5 min, and the supernatants were centrifuged at 10,000 g for 1 hour (Beckman SW60). The cytoplasmic extracts were then aliquoted in an amount of 5 to 12 mg/ml.

When the lysate of reticulocutes was incubated in the presence of cytoplasmic extracts, in the absence of calcium, no degradation was observed. On the other hand, in the presence of calcium, a very rapid degradation of the p53 proteins was observed, with the appearance of a characteristic proteolytic product profile similar to that obtained in Example 1.

This experiment indeed shows that the p53 proteins are degraded by the endogenous calpains.

2.2. Use of calpain inhibitors to modulate the levels of p53 proteins: the chelation of calcium by EGTA, as well as the use of a whole range of protease inhibitors (leupeptin, aprotinin, soybean trypsin inhibitor and PMSF) and especially the peptide calpastatin show that the degradation of these proteins is dependent on the calpains of the cytoplasmic extract, and that various compounds capable of modulating the activity of the calpains may be used to regulate the p53 protein levels.

Example 3 This example demonstrates that the mouse and human wild-type p53 proteins are direct substrates for the calpains in the cytoplasmic extracts.

Examples 1 and 2 show that the calpains can induce the degradation of p53 in complex reaction mixtures. These experiments do not exclude, however, that under the conditions used, the calpains activate secondary proteases which are those which actually act on p53. In this example, the following experiment was conducted: the mouse and human wild-type p53 proteins neosynthesized in the rabbit reticulocyte lysate were incubated for 30 minutes in the presence of a cytoplasmic extract of Daudi cells as well as in the presence of calcium to activate the calpains as in Example 2, p 53 protein was then added to the reaction mixture and the reaction was continued for minutes under conditions permissive (same reaction conditions) or otherwise (addition either of EGTA to chelate the calcium, or of calpastatin peptide) for the calpains. In the presence of calcium, the newly added p53 protein is completely degraded, indicating that the protease activity is functional throughout the experiment. When the calpains are inhibited by the presence of EGTA or, more significantly, of the calpastatin peptide, the newly added p53 protein is, on the other hand, no longer degraded. This latter observation therefore excludes the possibility that in the first part of the experiment, the calpains induced a second protease responsible for the degradation of p53 (Figure 1).

24 Example 4 This example describes the construction of a recombinant adenovirus comprising a nucleic acid sequence encoding calpastatin. This adenovirus is constructed by homologous recombination between the defective adenovirus Ad-d11324 and a plasmid carrying the sequence SEQ ID No. 1 under the control of the RSV promoter.

4.1. Construction of the plasmid SEQ ID No. 1 The plasmid SEQ ID No. 1 comprises the sequence encoding calpastatin under the control of the RSV-LTR promoter, as well as regions of the adenovirus which allow homologous recombination. It is constructed by inserting the sequence SEQ ID No. 1 into the plasmid pAd.RSVgal. The plasmid pAd.RSVAGal contains, in the orientation, the PvuII fragment corresponding to the left hand end of the Ad5 adenovirus comprising: the ITR sequence, the replication origin, the encapsidation signals and the enhancer E1A; the gene encoding P-galactosidase under the control of the RSV promoter (Rous sarcoma virus), a second fragment of the Ad5 adenovirus genome which allows homologous recombination between the plasmid pAd.RSV#Gal and the adenovirus d1324. The plasmid pAd.RSVAGal has been described by Stratford- Perricaudet et al. Clin. Invest. 90 (1992) 626).

4.2. Construction of the recombinant adenovirus The vector described in 4.1. is linearized and cotransfected with a deficient adenoviral vector into the helper cells (line 293) providing in trans the functions encoded by the adenovirus El regions (E1A and E11B).

More specifically, the recombinant adenovirus is obtained by homologous recombination in vivo between the mutant adenovirus Ad-d11324 (Thimmappaya et al., Cell 31 (1982) 543) and the vector described in Example according to the following procedure: the plasmid SEQ ID No. 1 and the adenovirus Ad-d11324, linearized by the enzyme Clal, are cotransfected into the line 293 in the presence of calcium phosphate, so as to allow the homologous recombination. The recombinant adenoviruses thus generated are then selected by plaque purification. After isolation, the recombinant adenovirus DNA is amplified in the cell line 293, leading to a culture supernatant containing the unpurified recombinant defective adenovirus having a titre of about 1010 pfu/ml.

The viral particles are purified by centrifugation on a caesium chloride gradient according to known techniques (see especially Graham et al., Virology 52 (1973) 456). The adenovirus obtained may be stored at -80 0 C in 20 glycerol.

26 SEQUENCE LISTING GENERAL INFORMATION:

APPLICANT:

NAME: RHONE-POULENC RORER S.A.

STREET: 20, avenue Raymond ARON CITY: ANTONY COUNTRY: FRANCE POSTAL CODE: 92165 (ii) TITLE OF THE INVENTION: Method of treating cancer by regulation of the p53 protein.

(iii) NUMBER OF SEQUENCES: 2 (iv) COMPUTER READABLE FORM: MEDIUM TYPE: Tape COMPUTER: IBM PC compatible OPERATING SYSTEM: PC-DOS/MS-DOS SOFTWARE: PatentIn Release Version #1.30 (EPO) INFORMATION FOR SEQ ID No.: 1: SEQUENCE CHARACTERISTICS: LENGTH: 2085 base pairs TYPE: nucleotide STRANDEDNESS: double TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (iv) ANTISENSE: NO ORIGINAL SOURCE: 27 ORGANISM: Homo sapiens (ix) FEATURE: NAME/KEY: CDS LOCATION: 1..2085 OTHER INFORMATION: /product "human calpastatin"

ATG

Met 1

GTA

Val

GTT

Val

CCA

Pro

CAC

His

AAA

Lys

GGA

Gly

AAG

Lys

AAA

Lys

GAC

Asp 145

ACA

Thr

ATA

Ile (xi) GAA GGA Glu Gly AAA ACA Lys Thr CAT GAG His Glu AAA AGC Lys Ser AAT AAA Asn Lys TCA ACA Ser Thr GAG AGT Glu Ser AAA AAA Lys Lys 115 CCG GAT Pro Asp 130 TTA ATA Leu lie ACG TAT Thr Tyr GAG GAA Glu Glu SEQUENCE DESCRIPTION: SEQ CCA CAT CTT CCT AAC AAG AAA AAA Pro His Leu Pro Asn Lys Lys Lys 5 10 GAA CCT GAG AAG AAG TCA CAG TCA Glu Pro Glu Lys Lys Ser Gin Ser 25 AAA AAA TCC CAA GAA GGA AAG CCA Lys Lys Ser Gin Glu Gly Lys Pro 40 CTA CCC AAG CAG GCA TCA GAT ACA Leu Pro Lys Gin Ala Ser Asp Thr ID No.: 1:

GCT

Ala

CAA

Gin

ATA

Ile

CCA

Pro

GGC

Gly

GAA

Glu

GAT

Asp 170

ACA

Thr CAC AAA AAA His Lys Lys ACC AAG CTG Thr Lys Leu AAA GAA CAC Lys Glu His GGA AGT AAC Gly Ser Asn CAG CAG CCA Gin Gin Pro ATG ATT TCT Met Ile Ser GGC AAG CCG Gly Lys Pro 110 GTG CCA GTT Val Pro Val 125 GAT GCT GCT Asp Ala Ala 140 ACT GAA GAA Thr Glu Glu ATG AGT TCC Met Ser Ser CCT CCA AAA Pro Pro Lys 190

CAG

Gin

TCT

Ser

ACA

Thr

GAT

Asp

TCA

Ser

GCT

Ala

GGT

Gly

GAA

Glu

TTG

Leu

GAA

Glu

ACC

Thr 175

TAT

Tyr

GCT

Ala

GTG

Val

GAG

Glu

GCT

Ala

GAG

Glu

GGT

Gly

GAC

Asp

TCT

Ser

GAT

Asp

AAT

Asn 160

TAC

Tyr

AGG

Arg 48 96 144 192 240 288 336 384 432 480 528 576 GAA CTA TTG Glu Leu Leu 195 GCT AAA AAG GAA Ala Lys Lys Glu

GGG

Gly 200 ATC ACA GGG CCT Ile Thr Gly Pro CCT GCA GAC TCT Pro Ala Asp Ser 205 ?CA AAA Ser Lys 210 CCC ATA CG Pro Ile Gly CCA GAT GAT Pro Asp Asp 215 TTrC Phe 225

GAA

Glu

GCT

Ala

AGT

Ser

GCA

Ala

AAA

Lys 305

ATC

Ile

CCA

Pro

GAA

Glu

GAG

Glu

GCT

Ala 385

ATA

Ile

GAT

Asp J GAT C Asp I

AAA

Lys G 4

CCT

Pro 465

ACC

Thz

TO

Sex GC3 Ala

GAT

Asp

GAA

Glu 290

GCT

Ala

CCA

Pro

CTA

Leu

CTC

Lou

AAA

Lys 370

CCA

Pro

:AG

;ln

AT

~sp

:CA

~ro

PAA

lu ~50 ,sp

TO~

Cys

AC)

Thr

CCA

Pro

'CAA

Gln 275

CCI

IPro

AAA

Lys

TCT

Ser

TTG

Lou

ATT

le 355

CCA

Pro

GCT

Ala

TCA

Ser

GCT

Ala

GAA

Glu 435

GAA

Glu

TAT

Tyr

GGG

Gly

GAA

Glu

CCC

Pro 260

GCA

Ala

GAG

Glu

GAA

Glu

GAG

Glu

CCA

Pro 340

GAT

Asp

TCT

Ser CCT4 Pro

GCA

Ala

GTA

Val 420 GAT C Asp C GAC C Asp) AGA Arg L

TO(

Se Va.

24! Glz

CT(

Let

CT(

Let GAl G11

TAC

Tyr 325

GAG

Gu

GAA

Glu

AAG

Lys

GTG

6ral

:CC

ro 105

PAA

;lu

;GA

;iy

~GT

Lrg

TA

,eu

.CCT

r Pro 230

!TTA

LLau

SGAG

i Glu

:GAG

I Glu

GAC

Asp

~AAA

Lys 310

AGA

Arg

CCT

Pro

CT?

Lou

CCA

Pro

TCG

Ser 390

CCT

Pro

GCC

Ala

AAAI

Lys

GAA

Glu

GAA

Glu C 470 ThV Lyi

LT-

GM~

Ali

CT(

Lei 291

CTJ

Lei

TV)

Let

GA)

Gll

TCA

Ser

ACT

Thr 375

GAG

Glu.

GAG

Glu

I'TG

Lau

CCT

Pro kAG 155

;AG

SAla

'GCT

SAla

AAA

LYS

LCTG

280

CGC

1Arg

SGAG

1Glu

LAAA

Lys

LGAA

Glu

GAA

Glu 360

GAA

Glu

GCT

Ala

CCG

Pro GCT4 Ala

GTG

Val 440 CTT c Lou C

GTC

Val

C

Ala

GCT

Ala

CAG

Gin

AGA

Arg 26.5

TCG

Ser

TCA

Ser

AAG

Lys

CCA

Pro

AAA

Lys 345

GAT

Asp

AAG

Lys

GTG

Val

GCT

Ala

GAT

425 4et

;GT

;iy c L AG G qs A AT4

CI

Glj

TOI

Sex 250

AMC

Lys elm Ala

ATT

le

TGTI

Cys

GCC

Ala 330

CCC

Pro Phe

ACA

Thr rCT 6cr

KCC

rhr 410 kJGC 3cr

"AT

ksp GAC GCC Asp Ala 220 ~AAG AAA Lye Lys 235 SGCA GGG Ala Gly GTG GAG Val Glu TCA CTG Sor Lou AAd GAA Lys Glu 300 GGT GAG Gly Glu 315 ACG GAT Thr Asp AAG CCT Lys Pro GAC CGC Asp Arg GAA GAA Giu Glu 380 COG ACC Arg Thr 395 TTG AAGc Lou Lys C CTG CGG Lou Gly I AAA GTC Lys Val L

TC

Lau

ACT

Thr

ACA

Thr

AAG

Lys

GGC

Gly 285

GTC

Val

GAT

Asp

AAA

Lys

CGG

Arg

I'CT

Scr 365

TCA

Ser

GAA

Glu

GTC

Val

GAT

Asp 270

ACC

Thr

GAT

Asp

CAT

Asp

GAT

Asp

AC?

Sor 350

GAA

Glu

TCII

Ser

AAA

Lys

AGA

Arg 255

ACA

?hr

CGG

Arg

GAG

Glu

OAA

Glu

GGA

Gly 335

GAA

Glu

TGT

Cys

GAC

Asp

*GAG

Glu 240

*AG?

Ser

ATG

met

CAA

Gin

GCA

Ala

ACA

Thr 320

AAA

Lys

TCA

Ser

AAA

Lys 672 720 768 816 864 912 960 1 008 1 056 1104 1152 1 200 1248 1296 1344 1 392 1440

TCT

Scr 3er

;GC

LAG

lye

'AA

iu

GA

ly

*AAG

Lys

ATG

Met

ACA

Thr

AAG

Lys 430

GAG

Glu

ACA

Thr

AAG

Lys CCC GCT Ala Ala TGT AG? Cys Ser 400 GTG CCA Val Pro 415 GAA GCA Glu Ala AAG CC Lys Ala ATT CC? Ile Pro CCA CTC Pro Lou 480

CAA

Glu 460

GAT

Asp 4

G

G

G

CTG

Lau CCA AAA GAG TCT Pro Lys Glu Ser AAG GAA CAG CTT Lys Glii Gln Lou

CCA

Pro 490 CCC ATG AGT GAA Pro Met Ser Glu GAG TTC Asp Phe 495 1 488

CTT

Lau

TCT

Ser

GTT

Val

GAT

Asp 545

GAT

Asp

AAA

Lys 515

CAA

Gin

TCG

Sar

GCT

Ala 500

TTT

Phe

ACC

Thr

CAG

Gin

TCT

Ser

GAT

As p

GCT

Ala

GAC

Asp 550

GAC

Asp

AAA

Lys 520

ACG

Thr

GAC

Asp TCT GAC Ser Asp ATG GGA Met Gly CTr GGA Lou Gly GAT GAT Asp Asp 610 GAG GAT Giu Asp 625 TCA GGA Ser Gly ACA GCA Thr Ala AAG AAT Lys Asn TCC AAG Ser Lys 690 ACT CTA GGA CAA AGG CAG Ser

GAT

Asp

GAA

Glu 595

AAT

Asn

TCA

Ser

GAT

Asp

AAG

LYS

GGA

Gly 675 Leu

AAA

Lys 580

AGA

Arq

GGA

Gly

AAG

Lys

CTG

Lau

GAT

Asp 660

GGT

Gly Gly Gin 565 GTA AAG Vai Lys GAT GAC Asp Asp CAG GAC Gin Asp AAA CCT Lys Pro 630 GAG AGC Asp Ser 645 MAG TGC Lys Cys AAA GCG Lys Ala Arg

GAA

Glu

ACT

Thr

AAA

LYS

615

GCA

Ala

TGT

Cys

AAG

Lys

MAG

LYS

TMA

695 Gin

AAA

LYS

ATC

le 600

CCA

Pro

GAT

Asp

CCC

Pro

MAG

LYS

GAT

Asp 680

TTC

Phe 505

CTT

Lou

ACC

Thr

CTC

Lou,

CCT

Pro

GCT

Ala 585

CCA

Pro

GTG

Val

GAC

Asp

TCC

Ser

GCT

Ala 665

TCA

Ser

TCT

Ser

GCT

Ala

CMA

Gin

GAT

Asp

GAC

Asp 57.0

AMA

Lys

CCT

Pro

MAG

Lys

CMA

Gin

ACT

Thr 650

GCT

Ala

GCA

Ala

GGT

Gly

GCT

Ala

GCT

Ala

GAT

Asp 555

CCA

Pro

GCT

Ala

GMA

Glu

CCA

Pro

GAC

Asp 635

ACA

Thr

TCC

Ser

MAG

Lys

CCA

Pro

GCC

Ala

GGA

Gly 540

GCC

Ala

GAT

Asp

GMA

Giu

TAC

Tyr

CCT

Pro 620

CCC

Pro

GMA

Giu

AGC

Ser

AICA

Thr Gin As~n 510 ATC TCT le Ser 525 GCC CCA Ala Pro TTG GAT Lou Asp GAG MAC Giu Asn CAT AGA His Arg .590 AGA CAT Arg His 605 ACA MAG Thr Lys ATT GAT le Asp ACC TCA Thr Ser TCC AMA Ser Lys 670 ACA GAG Thr Giu 685

GCT

Ala

GMA

Giu

CCC

Pro

AAA

Lys

MA

Lys 575

GAC

Asp

CTC

Leu

AMA

Lys

GCT

Ala

CAG

Gin 655

GCA

Ala

GMA

Giu

TCA

Ser

GTG

Val

CGT

Arg

CTC

Leu 560

CCA

Pro

MAG

Lys

CTG

Leu

TCA

Ser

CTC

Leu 640

MAC

Asn

CCT

Pro

ACT

Thr 1 536 1 584 1632 1680 1728 1776 1824 1 872 1 920 1968 2016 2064 2085 CCA AMA GAT GAC Pro Lys Asp Asp INFORMATION FOR SEQ ID NO.: 2: ()SEQUENCE

CHARACTERISTICS:

LENGTH: 399 base pairs TYPE: nucleotide STRANDEDNESS: double TOPOLOGY: linear (i)MOLECULE TYPE: cDNA ii)HYPOTHETICAL: NO (iv) ANTISENSE: NO (vi) ORIGINAL SOURCE: ORGANISM: homo sapiens (ix) FEATURE: NAME/KEY: CDS LOCATION: 1..399 (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 3: TCA GGC ATG GAT GCT GCT TTG GAT GAC TTk ATA GAT ACT TTA GGA GGA 48 Ser Gly Met Asp Ala Ala Leu Asp Asp Lou le Asp Thr Lou Gly Gly 700 705 710 CCT GAA GAA ACT GAA GAA GAA AAT ACA ACG TAT ACT GGA CCA GAA GTT 96 Pro Giu Glu Thr Glu Glu Giu Asn Thr Thr Tyr Thr Gly Pro Giu Val 715 720 725 TCA GAT CCA ATG AGT TCC ACC TAC ATA GAG GAA TTG GGT AAA AGA GAA 144 Ser Asp Pro Met Ser Ser Thr Tyr le Giu Glu Lou Gly Lys Arg Giu 730 735 740 GTC ACA ATT CCT CCA AAA TAT AGG GAA CTA TTG GCT AAA AAG GAA GGG 192 Val Thr Ile Pro Pro Lys Tyr Arg Glu Lou Lou Ala Lys Lys Giu Giy 745 750 755 ATC ACA GGG CCT CCT GCA GAC TCT TCA AAA CCC ATA GGG CCA GAT GAT 2.40 Ile Thr Gly Pro Pro Ala Asp Ser Ser Lys Pro Ile Gly Pro Asp Asp 760 765 770 775 GCT ATA GAC GCC TTG TCA TCT GAC TTC ACC TGT GGG TCG CCT ACA GCT 288 Ala Ile Asp Ala Lou Ser Ser Asp Phe Thr Cys Gly Ser Pro Thr Ala 780 785 790 GCT GGA AAG AAA ACT GAA AAA GAG GAA TCT ACA GAA GTT TTA AAA GCT 336 Ala Gly Lys Lys Thr Glu Lys Glu Glu Ser Thr Giu Val Leu Lys Ala 795 800 805 CAG TCA GCA GGG ACA GTC AGA AGT GCT GCT CCA CCC CAA GAG AAG AAA 384 Gin Ser Ala Gly Thr Val Arg Ser Ala Ala Pro Pro Gin Giu Lys Lys 810 815 820 AGA AAG GTG GAG AAG 399 Arg Lys Val Giu Lys 825

Claims (17)

1. Use of a compound capable of modulating the activity of calpain for the preparation of a pharmaceutical composition for a method of treatment by regulating the cellular levels of the p53 protein.

2. Use according to claim 1, characterised in that the compound is a protein or a polypeptide which is an inhibitor of the activity of calpain, or a nucleic acid sequence encoding such a polypeptide or protein.

3. Use according to claim 2, characterized in that the compound is a protein or a polypeptide which is a specific inhibitor of the activity of calpain on the wild-type p53 protein, or a nucleic acid sequence encoding such a polypeptide or protein.

4. Use according to claim 2 or 3, characterized in that the nucleic acid is part of a vector. 5 Use according to claim 4, characterized in that the nucleic acid is part of a viral vector, chosen from adenoviruses, retroviruses and adeno-associated viruses.

6. Use according to claim 4, characterized in that the nucleic acid is part of a lipid liposomal vector.

7. Use according to one of the preceding claims, characterized in that the compound is a nucleic acid encoding all or part of calpastatin.

8. Use according to claim 7, characterized in that the nucleic acid comprises all or part of the sequence SEQ ID No.1 or a derivative thereof.

9. Use according to claim 8, characterized in that the nucleic acid is SEQ ID No. 1 or Q:\OPER\EJH\IPEA.307 3/11/99 -32- Use according to claim 8, characterized in that the nucleic acid is chosen from the derivatives of the sequences SEQ ID No. 1 or 2 encoding specific inhibitors of the degradation of the wild-type p53 protein.

11. Use according to any one of claims 1 to 6, characterized in that the compound is a derivative of calpain capable of specifically degrading the mutated p53 proteins.

12. Viral vector comprising a nucleic acid sequence encoding a protein or a polypeptide which is an inhibitor of the activity of calpain and chosen from the adenoviruses, retroviruses and adeno-associated viruses when used in a method of treatment by regulating the cellular levels of the p53 protein.

13. Vector according to claim 12, characterized in that it comprises a sequence encoding all or part of calpastatin when used in a method of treatment by regulating the cellular levels of the p53 protein.

14. Vector according to claim 12, characterized in that it comprises a sequence encoding a derivative of calpain capable of specifically degrading the mutated p53 proteins when used in a method of treatment by regulating the cellular levels of the p53 protein.

15. Pharmaceutical composition comprising a nucleic acid sequence encoding all or part of calpastatin, or (ii) a derivative of Calpain capable of specifically degrading the mutated p53 proteins, and a pharmaceutically acceptable diluent or carrier when used in a S: :method of treatment by regulating the cellular levels of the p53 protein. *Ppppp

16. Composition according to claim 15, formulated for intra-tumor administration when used in a method of treatment by regulating the cellular levels of the p53 protein.

17. Use of a vector or composition according to any one of claims 12 to 16 for the preparation of a pharmaceutical composition for a method of treatment by regulating the s cellular levels of the p53 protein. Q:\OPER\EJH\IPEA.307 3/11/99 -33-

18. Method of treating by regulating the cellular levels of the p53 protein comprising administering a compound, protein or polypeptide, nucleic acid, vector or composition as defined in any one of claims 1 to 16.

19. Use according to claim 1 substantially as described hereinbefore in any one of the Examples. Method according to claim 18 substantially as described herinbefore on any one of the Examples. DATED This 3rd day of November 1999. OWNER Rhone-Poulenc Rorer S.A. By Davies Collison Cave Patent Attorney for the Applicant eg* C C e C C