Biomedical subjects

Francesco Trapasso

Publications and source records attributed to Francesco Trapasso.

At least 19 recordsLinked to original sources

PubMed2025

Cytogenetic and molecular characterization of an atypical ETP-ALL case with BCL2 dependency: therapeutic implications for Venetoclax use.

BACKGROUND: Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a rare, high-risk subtype of T-ALL characterized by distinctive immunophenotypic and genomic features. It is often associated with induction failure and frequent relapses. Despite recent advances in its molecular characterization, the prognosis remains dismal, and effective targeted therapies are limited. METHODS AND RESULTS: We report a pediatric, multi-refractory ETP-ALL case with novel cytogenetic alterations, including a 4q deletion and a t(16;18)(q24;q21) translocation. Molecular profiling revealed progressive activation of the BCL2 pathway and disruption of Th17-related immune markers. Ex vivo sensitivity assays performed at different disease stages demonstrated increasing BCL2 dependency. Based on these findings, venetoclax was administered on a compassionate-use basis, resulting in rapid hematologic recovery and a marked reduction in blast percentage. CONCLUSIONS: This case highlights the role of clonal evolution and immune deregulation in accompanying BCL2 addiction in relapsed ETP-ALL. Altogether, our findings underscore the therapeutic potential of venetoclax in refractory pediatric ETP-ALL cases with progressive BCL2 dependency.

Humans↗

PubMed2006

Physical association with WWOX suppresses c-Jun transcriptional activity.

WWOX is a tumor suppressor that functions as a modular protein partner of transcription factors. WWOX contains two WW domains that mediate protein-protein interactions. In this report, we show that WWOX, via its first WW domain, specifically associates with the proline-rich motif of c-Jun proto-oncogene. Our data show that phosphorylation of c-Jun caused by overexpression of mitogen-activated protein kinase kinase kinase 1 (Mekk1), an upstream activator of c-Jun, enhances the interaction of c-Jun with WWOX. Furthermore, exposure of HaCaT keratinocytes to UVC radiation resulted in the association of endogenous WWOX and c-Jun. The WWOX-c-Jun complexes mainly occur in the cytoplasm. Expression of WWOX attenuates the ability of MEKK1 to increase the activity of a c-Jun-driven activating protein-1 (AP-1)-luciferase reporter plasmid. In contrast, a point mutation in the first WW domain of WWOX has no effect on transactivation of AP-1 when coexpressed with c-Jun protein. Our findings reveal a novel functional cross-talk between c-Jun transcription factor and WWOX tumor suppressor protein.

Cell Line↗

PubMed2006

Fhit modulates the DNA damage checkpoint response.

In preneoplastic lesions, the DNA damage checkpoint is induced and loss of heterozygosity at the FRA3B/FHIT common chromosome fragile region precedes or is coincident with activation of the checkpoint response in these early stages. Introduction of exogenous Fhit into cells in vitro led to modulation of expression of checkpoint proteins Hus1 and Chk1 at mid-S checkpoint, a modulation that led to induction of apoptosis in esophageal cancer cells but not in noncancerous primary cultures. Mutation of the conserved Fhit tyrosine 114 resulted in failure of this function, confirming the importance of this residue. The results suggest that the DNA damage-susceptible FRA3B/FHIT chromosome fragile region, paradoxically, encodes a protein that is necessary for protecting cells from accumulation of DNA damage through its role in modulation of checkpoint proteins, and inactivation of Fhit contributes to accumulation of abnormal checkpoint phenotypes in cancer development.

Acid Anhydride Hydrolases↗

PubMed2006

Alterations of the tumor suppressor gene ARLTS1 in ovarian cancer.

ARLTS1 is a tumor suppressor gene initially described as a low-penetrance cancer gene: a truncated Trp149Stop (MUT) polymorphism is associated with general familial cancer aggregation and, particularly, high-risk familial breast cancer. DNA hypermethylation has been identified as a mechanism of ARLTS1 expression down-regulation in lung carcinomas and B-cell chronic lymphocytic leukemia. We found that, in the majority of ovarian carcinomas (61.5%) and in a significant proportion of ovarian and breast cancer cell lines (45%), ARLTS1 is strongly down-regulated due to DNA methylation in its promoter region. After ARLTS1 restoration by adenoviral transduction, only the negative TOV-112 and the homozygously mutated (MUT) MCF7 cells, but not the OV-90 cells expressing a normal ARLTS1 product, underwent apoptosis and inhibition of cell growth. Furthermore, ARLTS1 reexpression significantly reduced the tumorigenic potential of TOV-112 in nude mice. On the contrary, the ARLTS1-MUT induced significantly lower levels of apoptosis in infected cells and reduced in vivo tumorigenesis only partially, supporting the hypothesis that Trp149Stop polymorphism is retained in the general population and predisposes to cancer because of a reduction, but not full loss, of normal ARLTS1 function.

ADP-Ribosylation Factors↗

PubMed2006

Biological functions of mammalian Nit1, the counterpart of the invertebrate NitFhit Rosetta stone protein, a possible tumor suppressor.

The "Rosetta Stone" hypothesis proposes that the existence of a fusion protein in some organisms predicts that the separate polypeptides function in the same biochemical pathway in other organisms and may physically interact. In Drosophila melanogaster and Caenorhabditis elegans, NitFhit protein is composed of two domains, a fragile histidine triad homolog and a bacterial and plant nitrilase homolog. We assessed the biological effects of mammalian Nit1 expression in comparison with Fhit and observed that: 1) Nit1 expression was observed in most normal tissues and overlapped partially with Fhit expression; 2) Nit1-deficient mouse kidney cells exhibited accelerated proliferation, resistance to DNA damage stress, and increased cyclin D1 expression; 3) cyclin D1 was up-regulated in Nit1 null mammary gland and skin; 4) Nit1 overexpression induced caspase-dependent apoptosis in vitro; and 5) Nit1 allele deficiency led to increased incidence of N-nitrosomethylbenzylamine-induced murine forestomach tumors. Thus, the biological effects of Nit1 expression are similar to Fhit effects. Adenoviruses carrying recombinant NIT1 and FHIT induced apoptosis in Fhit- and Nit1-deficient cells, respectively, suggesting that Nit1-Fhit interaction is not essential for function of either protein. The results suggest that Nit1 and Fhit share tumor suppressor signaling pathways, while localization of the NIT1 gene at a stable, rather than fragile, chromosome site explains the paucity of gene alterations and in frequent loss of expression of the NIT1 gene in human malignancies.

Acid Anhydride Hydrolases↗

PubMed2006

The receptor-type protein tyrosine phosphatase J antagonizes the biochemical and biological effects of RET-derived oncoproteins.

Thyroid cancer is frequently associated with the oncogenic conversion of the RET receptor tyrosine kinase. RET gene rearrangements, which lead to the generation of chimeric RET/papillary thyroid carcinoma (PTC) oncogenes, occur in PTC, whereas RET point mutations occur in familial multiple endocrine neoplasia type 2 (MEN2) and sporadic medullary thyroid carcinomas (MTC). We showed previously that the expression of the receptor-type protein tyrosine phosphatase J (PTPRJ) is suppressed in neoplastically transformed follicular thyroid cells. We now report that PTPRJ coimmunoprecipitates with wild-type RET and with the MEN2A-associated RET(C634R) oncoprotein but not with the RET/PTC1 and RET-MEN2B isoforms. Using mutated forms of PTPRJ and RET-MEN2A, we show that the integrity of the respective catalytic domains is required for the PTPRJ/RET-MEN2A interaction. PTPRJ expression induces dephosphorylation of the RET(C634R) and, probably via an indirect mechanism, RET/PTC1 oncoproteins on two key RET autophosphorylation sites (Tyr1062 and Tyr905). This results in a significant decrease of RET-induced Shc and extracellular signal-regulated kinase 1/2 phosphorylation levels. In line with this finding, adoptive PTPRJ expression reduced the oncogenic activity of RET(C634R) in an in vitro focus formation assay of NIH3T3 cells. As expected from the coimmunoprecipitation results, the RET(M918T) oncoprotein, which is associated to MEN2B and sporadic MTC, was resistant to the dephosphorylating activity of PTPRJ. Taken together, these findings identify RET as a novel substrate of PTPRJ and suggest that PTPRJ expression levels may affect tumor phenotype associated with RET/PTC1 and RET(C634R) mutants. On the other hand, resistance to PTPRJ may be part of the mechanism of RET oncogenic conversion secondary to the M918T mutation.

Cell Line, Tumor↗

PubMed2006

Preclinical assessment of FHIT gene replacement therapy in human leukemia using a chimeric adenovirus, Ad5/F35.

PURPOSE: Expression of the FHIT protein is lost or reduced in most solid tumors and a significant fraction of hematopoietic malignancies. Adenovirus 5 (Ad5) virus or adeno-associated viral vectors have been used to study the tumor suppressor function of FHIT in solid tumors, but these tools have not been effective in leukemias. We have generated a chimeric FHIT-containing adenovirus composed of Ad5 and the group B adenovirus called F35 with which we have been able to efficiently infect hematopoietic cells. EXPERIMENTAL DESIGN: Infection efficiency of Ad5/F35-FHIT and Ad5/F35-GFP viruses was tested in leukemia cell lines that lacked FHIT expression, and biological effects of successful infection were assessed. An acute myelogenous leukemia, a chronic myelogenous leukemia, and four acute lymphoblastic leukemia human cell lines were examined as well as two EBV-transformed B lymphoblastoid cell lines that expressed endogenous FHIT. RESULTS: Two of four acute lymphoblastic leukemia cell lines, Jurkat and MV4;11, which were efficiently infected with Ad5/F35-FHIT, underwent growth suppression and massive induction of apoptosis without apparent activation of caspase-8 or caspase-2 and late activation of caspase-3. Treatment of infected cells with caspase-9 and caspase-3 inhibitors partially blocked FHIT-induced apoptosis. The two remaining infected acute lymphoblastic leukemia cell lines, Molt-3 and RS4;11, were apparently unaffected. Restoration of FHIT expression in the chronic myelogenous leukemia K562 cell line and the acute myelogenous leukemia KG1a cell line also induced apoptosis but at later time points than seen in the acute lymphoblastic leukemia Jurkat and MV4;11 cell lines. I.v. injection of Ad5/F35-FHIT-infected Jurkat cells resulted in abrogation of tumorigenicity in the NOD/SCID xenogeneic engraftment model. CONCLUSION: FHIT restoration in some FHIT-deficient leukemia cells induces both antiproliferative and proapoptotic effects involving the intrinsic caspase apoptotic pathway.

Acid Anhydride Hydrolases↗

PubMed2006

Genetic ablation of Ptprj, a mouse cancer susceptibility gene, results in normal growth and development and does not predispose to spontaneous tumorigenesis.

Ptprj is a ubiquitously expressed murine gene encoding a receptor-type protein tyrosine phosphatase, which has recently been proposed as a candidate gene on the locus Scc1 for colon cancer susceptibility. It has been demonstrated that PTPRJ, the human homologue of Ptprj, is involved in the control of cell growth and adhesion, being furthermore altered in several types of cancer including mammary, thyroid, lung, colon, and pancreatic cancers. To investigate the biological functions of Ptprj, we have generated mice deficient in this receptor protein tyrosine phosphatase. Ptprj-deficient mice are viable, fertile, and show no gross anatomical alterations. Furthermore, neither changes in life span nor spontaneous tumor appearance were observed in Ptprj-null mice. Our results indicate that Ptprj is dispensable for normal growth and development in mice.

Animals↗

PubMed2005

WWOX gene restoration prevents lung cancer growth in vitro and in vivo.

The WWOX (WW domain containing oxidoreductase) gene at the common fragile site, FRA16D, is altered in many types of cancer, including lung cancer. We have examined the tumor suppressor function of WWOX in preclinical lung cancer models. The WWOX gene was expressed in lung cancer cell lines through recombinant adenovirus (Ad) infection (Ad-WWOX), and through a drug [ponasterone A, (ponA)]-inducible system. After WWOX restoration in vitro, endogenous Wwox protein-negative cell lines (A549, H460, and H1299) underwent apoptosis through activation of the intrinsic apoptotic caspase cascade in A549 and H460 cells. Ectopic expression of Wwox caused dramatic suppression of tumorigenicity of A549, H460, and H1299 cells in nude mice after Ad-WWOX infection and after ponA induction of Wwox expression in H1299 lung cancer cells. Tumorigenicity and in vitro growth of U2020 (Wwox-positive) lung cancer cells was unaffected by Wwox overexpression. This study confirms that WWOX is a tumor suppressor gene and is highly effective in preventing growth of lung cancer xenografts, whether introduced through viral infection or by induction of a silent WWOX transgene.

Adenoviridae↗

PubMed2005

WW domain-containing proteins, WWOX and YAP, compete for interaction with ErbB-4 and modulate its transcriptional function.

The WW domain-containing oxidoreductase, WWOX, is a tumor suppressor that is deleted or altered in several cancer types. We recently showed that WWOX interacts with p73 and AP-2gamma and suppresses their transcriptional activity. Yes-associated protein (YAP), also containing WW domains, was shown to associate with p73 and enhance its transcriptional activity. In addition, YAP interacts with ErbB-4 receptor tyrosine kinase and acts as transcriptional coactivator of the COOH-terminal fragment (CTF) of ErbB-4. Stimulation of ErbB-4-expressing cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) results in the proteolytic cleavage of its cytoplasmic domain and translocation of this domain to the nucleus. Here we report that WWOX physically associates with the full-length ErbB-4 via its first WW domain. Coexpression of WWOX and ErbB-4 in HeLa cells followed by treatment with TPA results in the retention of ErbB-4 in the cytoplasm. Moreover, in MCF-7 breast carcinoma cells, expressing high levels of endogenous WWOX, endogenous ErbB-4 is also retained in the cytoplasm. In addition, our results show that interaction of WWOX and ErbB-4 suppresses transcriptional coactivation of CTF by YAP in a dose-dependent manner. A mutant form of WWOX lacking interaction with ErbB-4 has no effect on this coactivation of ErbB-4. Furthermore, WWOX is able to inhibit coactivation of p73 by YAP. In summary, our data indicate that WWOX antagonizes the function of YAP by competing for interaction with ErbB-4 and other targets and thus affect its transcriptional activity.

Amino Acid Sequence↗

PubMed2005

Knockout mice reveal a tumor suppressor function for Testin.

The Testin (TES) gene was previously identified as a putative human tumor suppressor gene at 7q31.2, a region that is frequently deleted in hematopoietic malignancies, as well as in epithelial tumors. To determine whether TES acts as a tumor suppressor in vivo, we generated a Tes knockout mouse and then used it in an established model of carcinogen-induced gastric cancer. In mice a zinc-deficient (ZD) diet enhances cellular proliferation in the forestomach and susceptibility to N-nitrosomethylbenzylamine (NMBA)-induced carcinogenesis. Five-week-old Tes wild-type (+/+), heterozygous (+/-), and homozygous (-/-) mice were divided into four groups: mice fed a zinc-sufficient diet (ZS); mice fed a ZD diet; ZS fed plus NMBA-treated mice (ZS+NMBA), and ZD fed plus NMBA-treated mice (ZD+NMBA). After 4 weeks, the ZS+NMBA and ZD+NMBA groups were treated with three intragastric doses of NMBA. Animals were killed 8 weeks after NMBA administration: 25% of +/+ mice developed benign lesions; 88% of +/- showed multiple papillomas, atypical glandular metaplasia, and squamous cell carcinomasl; and 81% of -/- mice displayed very large papillomas, squamous cell carcinomas, and adenocarcinomas. A statistically significant difference in tumor incidence was found between +/- versus +/+ and -/- versus +/+ (P < 0.0001). These data suggest that Tes functions as a tumor suppressor gene in vivo.

Adenocarcinoma↗

PubMed2005

The rat tyrosine phosphatase eta increases cell adhesion by activating c-Src through dephosphorylation of its inhibitory phosphotyrosine residue.

The expression of the receptor protein tyrosine phosphatase r-PTPeta is drastically reduced in rat and human malignant thyroid cells, whereas its restoration reverts the neoplastic phenotype of retrovirally transformed rat thyroid cells. Moreover, reduced levels and loss of heterozygosity of DEP-1, the human homolog of r-PTPeta, have been found in many human neoplasias. Here, we report that the r-PTPeta protein binds to c-Src in living cells and dephosphorylates the c-Src inhibitory tyrosine phosphorylation site (Tyr 529), thereby increasing c-Src tyrosine kinase activity in malignant rat thyroid cells stably transfected with r-PTPeta. Tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin was enhanced in r-PTPeta-expressing cells. This was associated with increased adhesion of malignant r-PTPeta-transfected thyroid cells vs both untransfected cells and cells stably transfected with an inactive r-PTPeta mutant. Treatment of rat thyroid cells with the c-Src inhibitor PP2 decreased cell adhesion to a higher extent in r-PTPeta-transfected cells than in mock-transfected or stably transfected cells with the inactive r-PTPeta mutant, indicating that r-PTPeta regulates cell-substratum adhesion by activating c-Src. Interestingly, the extent of both c-Src dephosphorylation at Tyr 529, FAK and paxillin phosphorylation, and the increased cell adhesion were associated with the degree of r-PTPeta expression.

Animals↗

PubMed2005

Familial cancer associated with a polymorphism in ARLTS1.

BACKGROUND: The finding of hemizygous or homozygous deletions at band 14 on chromosome 13 in a variety of neoplasms suggests the presence of a tumor-suppressor locus telomeric to the RB1 gene. METHODS: We studied samples from 216 patients with various types of sporadic tumors or idiopathic pancytopenia, peripheral-blood samples from 109 patients with familial cancer or multiple cancers, and control blood samples from 475 healthy people or patients with diseases other than cancer. We performed functional studies of cell lines lacking ARLTS1 expression with the use of both the full-length ARLTS1 gene and a truncated variant. RESULTS: We found a gene at 13q14, ARLTS1, a member of the ADP-ribosylation factor family, with properties of a tumor-suppressor gene. We analyzed 800 DNA samples from tumors and blood cells from patients with sporadic or familial cancer and controls and found that the frequency of a nonsense polymorphism, G446A (Trp149Stop), was similar in controls and patients with sporadic tumors but was significantly more common among patients with familial cancer than among those in the other two groups (P=0.02; odds ratio, 5.7; 95 percent confidence interval, 1.3 to 24.8). ARLTS1 was down-regulated by promoter methylation in 25 percent of the primary tumors we analyzed. Transfection of wild-type ARLTS1 into A549 lung-cancer cells suppressed tumor formation in immunodeficient mice and induced apoptosis, whereas transfection of truncated ARLTS1 had a limited effect on apoptosis and tumor suppression. Microarray analysis revealed that the wild-type and Trp149Stop-transfected clones had different expression profiles. CONCLUSIONS: A genetic variant of ARLTS1 predisposes patients to familial cancer.

ADP-Ribosylation Factors↗

PubMed2004

The tyrosine phosphatase PTPRJ/DEP-1 genotype affects thyroid carcinogenesis.

We recently isolated the r-PTPeta gene, which encodes a receptor-type tyrosine phosphatase protein that suppresses the neoplastic phenotype of retrovirally transformed rat thyroid cells. The human homologue gene PTPRJ/DEP-1 is deleted in various tumors. Moreover, the Gln276Pro polymorphism, located in the extracellular region of the gene, seems to play a critical role in susceptibility to some human neoplasias. Here we report the loss of heterozygosity (LOH) of PTPRJ in 11/76 (14.5%) informative thyroid tumors (including adenomas and carcinomas). We also looked for the Gln276Pro, Arg326Gln and Asp872Glu polymorphisms in exons 5, 6 and 13 of PTPRJ in 88 patients with thyroid tumors and in 54 healthy individuals. We found that the PTPRJ genotypes homozygous for the Gln276Pro and Arg326Gln polymorphisms, and the Asp872 allele were more frequent in thyroid carcinoma patients than in healthy individuals (P=0.032). In addition, PTPRJ LOH was more frequent in thyroid carcinomas of heterozygotes for Gln276Pro and Arg326Gln compared with homozygotes (P=0.006). This suggests that the presence of hemizygosity for these polymorphisms in the tumor facilitates tumor progression. These results indicate that the genotypic profile of PTPRJ affects susceptibility to thyroid carcinomas, and that allelic loss of this gene is involved in thyroid carcinogenesis.

Adenoma↗

PubMed2004

Restoration of receptor-type protein tyrosine phosphatase eta function inhibits human pancreatic carcinoma cell growth in vitro and in vivo.

DEP-1/HPTPeta, a receptor-type protein tyrosine phosphatase, is a candidate tumor suppressor gene because its expression was blocked in rat and human thyroid transformed cells, and its restoration reverted their neoplastic phenotype. In addition, loss of DEP-1/HPTPeta heterozygosity has been described in mammary, lung and colon primary tumors. We now show that DEP-1/HPTPeta is drastically reduced in several cell lines originating from human epithelial pancreatic carcinomas compared with normal pancreatic tissue. We also show that the infection of AsPC1 and PSN1 cells with a recombinant adenovirus carrying r-PTPeta cDNA (the rat homolog of DEP-1/HPTPeta) inhibits their proliferation. Flow cytometric analysis of the infected cells demonstrated that restoration of r-PTPeta activity disrupts their cell cycle and leads to apoptosis. Finally, the growth of PSN1 xenograft tumors was blocked by the intratumoral injection of a recombinant adeno-associated virus carrying r-PTPeta. The data suggest that restoration of DEP-1/HPTPeta expression could be a useful tool for the gene therapy of human pancreatic cancers.

Animals↗

PubMed2004

Loss of WWOX expression in gastric carcinoma.

PURPOSE: WW domain-containing oxidoreductase (WWOX) is a tumor suppressor gene that maps to the common fragile site FRA16D on chromosome 16q23.3-24.1. To investigate the role of the WWOX gene in the development of gastric carcinoma, we examined a large series of primary adenocarcinomas and nine gastric cancer cell lines for the expression of Wwox. EXPERIMENTAL DESIGN: Loss of heterozygosity, reverse-transcription-PCR, and immunohistochemistry were used to assess the role of WWOX in stomach cancer. A total of 81 primary gastric adenocarcinoma were analyzed. RESULTS: Loss of heterozygosity was observed in 31% of the cases and loss of Wwox protein expression was found in 65% of gastric adenocarcinoma primary specimens and 33% of gastric cancer cell lines. In addition, we found a high correlation between Wwox and Fhit protein expression. CONCLUSIONS: Our results indicate that alterations of the WWOX gene may be involved quite frequently in gastric tumorigenesis. Our data could be used in future studies to develop diagnostic and targeted therapy of stomach cancer.

Adenocarcinoma↗

PubMed2004

The tumor suppressor gene WWOX at FRA16D is involved in pancreatic carcinogenesis.

PURPOSE: WWOX (WW domain containing oxidoreductase) is a tumor suppressor gene that maps to the common fragile site FRA16D. We showed previously that WWOX is frequently altered in human lung and esophageal cancers. The purpose of this study was to delineate more precisely the role of WWOX in pancreatic carcinogenesis. EXPERIMENTAL DESIGN: We analyzed 15 paired pancreatic adenocarcinoma samples and 9 pancreatic cancer cell lines for WWOX alterations. Colony assay and cell cycle analysis were also performed to evaluate the role of the WWOX as a tumor suppressor gene. RESULTS: Loss of heterozygosity at the WWOX locus was observed in 4 primary tumors (27%). Methylation analysis showed that site-specific promoter hypermethylation was detected in 2 cell lines (22%) and treatment with the demethylating agent 5-aza-2'-deoxycytidine demonstrated an increase in the expression of WWOX. In addition, 2 primary tumor samples (13%) showed promoter hypermethylation including the position of site-specific methylation. Transcripts missing WWOX exons were detected in 4 cell lines (44%) and in 2 tumor samples (13%). Real-time reverse transcription PCR revealed a significant reduction of WWOX expression in all of the cell lines and in 6 primary tumors (40%). Western blot analysis showed a significant reduction of the WWOX protein in all of the cell lines. Furthermore, transfection with WWOX inhibited colony formation of pancreatic cancer cell lines by triggering apoptosis. CONCLUSION: These results indicate that the WWOX gene may play an important role in pancreatic tumor development.

Adenocarcinoma↗

PubMed2004

Functional association between Wwox tumor suppressor protein and p73, a p53 homolog.

The WWOX gene is a recently cloned tumor suppressor gene that spans the FRA16D fragile region. Wwox protein contains two WW domains that are generally known to mediate protein-protein interaction. Here we show that Wwox physically interacts via its first WW domain with the p53 homolog, p73. The tyrosine kinase, Src, phosphorylates Wwox at tyrosine 33 in the first WW domain and enhances its binding to p73. Our results further demonstrate that Wwox expression triggers redistribution of nuclear p73 to the cytoplasm and, hence, suppresses its transcriptional activity. In addition, we show that cytoplasmic p73 contributes to the proapoptotic activity of Wwox. Our findings reveal a functional cross-talk between p73 and Wwox tumor suppressor protein.

Cell Line↗