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TP73; tumor protein p73 (1p36.3)

Gene Summary

Gene:TP73; tumor protein p73
Aliases: P73
Location:1p36.3
Summary:This gene encodes a member of the p53 family of transcription factors involved in cellular responses to stress and development. It maps to a region on chromosome 1p36 that is frequently deleted in neuroblastoma and other tumors, and thought to contain multiple tumor suppressor genes. The demonstration that this gene is monoallelically expressed (likely from the maternal allele), supports the notion that it is a candidate gene for neuroblastoma. Many transcript variants resulting from alternative splicing and/or use of alternate promoters have been found for this gene, but the biological validity and the full-length nature of some variants have not been determined. [provided by RefSeq, Feb 2011]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:tumor protein p73
HPRD
Source:NCBI
Updated:14 December, 2014

Gene
Ontology:

What does this gene/protein do?
Show (48)

Pathways:

What pathways are this gene/protein implicaed in?
- ATM Signaling Pathway BIOCARTA
Data from KEGG and BioCarta [BIOCARTA terms] via CGAP

Cancer Overview

Research Indicators

Publications Per Year (1989-2014)
Graph generated 14 December 2014 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

Tag cloud generated 14 December, 2014 using data from PubMed, MeSH and CancerIndex

Notable (5)

Scope includes mutations and abnormal protein expression.

Entity Topic PubMed Papers
-TP73 and Adenocarcinoma View Publications20
Breast CancerTP73 and Breast Cancer View Publications9
NeuroblastomaTP73 and Neuroblastoma
TP73 was a candidate tumour suppresser gene for neuroblastoma given that a) the gene is homologous to TP53 and b) TP73 is located in the 1p36 region which is frequently deleted in neuroblastoma. However, research suggests that TP73 is infrequently mutated in neuroblastoma; in a study including tumours detected by mass screening (Ichimiya et al, 1999) only 2 out of 140 neuroblastomas had TP73 mutations; though LOH for TP73 was seen in 19% of tumours with LOH more frequent in neuroblastomas which were sporadic (not detected by screening), MYCN amplified, and advanced stages. While TP73 may not be a classic Knudson's type tumour supressor gene for neuroblastoma its role in the disease remains to be clarified.
View Publications6
Lung CancerTP73 and Lung Cancer View Publications5
Bladder CancerTP73 Overexpression in Bladder Cancer View Publications2

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Related Links

Latest Publications: TP73 (cancer-related)

Costanzo A, Pediconi N, Narcisi A, et al.
TP63 and TP73 in cancer, an unresolved "family" puzzle of complexity, redundancy and hierarchy.
FEBS Lett. 2014; 588(16):2590-9 [PubMed] Related Publications
TP53 belongs to a small gene family that includes, in mammals, two additional paralogs, TP63 and TP73. The p63 and p73 proteins are structurally and functionally similar to p53 and their activity as transcription factors is regulated by a wide repertoire of shared and unique post-translational modifications and interactions with regulatory cofactors. p63 and p73 have important functions in embryonic development and differentiation but are also involved in tumor suppression. The biology of p63 and p73 is complex since both TP63 and TP73 genes are transcribed into a variety of different isoforms that give rise to proteins with antagonistic properties, the TA-isoforms that act as tumor-suppressors and DN-isoforms that behave as proto-oncogenes. The p53 family as a whole behaves as a signaling "network" that integrates developmental, metabolic and stress signals to control cell metabolism, differentiation, longevity, proliferation and death. Despite the progress of our knowledge, the unresolved puzzle of complexity, redundancy and hierarchy in the p53 family continues to represent a formidable challenge.

Related: Cancer Prevention and Risk Reduction TP53


Park GB, Choi Y, Kim YS, et al.
Silencing of PKCη induces cycle arrest of EBV(+) B lymphoma cells by upregulating expression of p38-MAPK/TAp73/GADD45α and increases susceptibility to chemotherapeutic agents.
Cancer Lett. 2014; 350(1-2):5-14 [PubMed] Related Publications
PKCη is involved in proliferation, differentiation, and drug resistance. However, PKCη function in EBV(+) B lymphoma remains poorly understood. Gene silencing of PKCη through siRNA knockdown inhibited cellular proliferation, induced cell cycle arrest in G0/G1 and G2/M phases, and sensitized cells to chemotherapeutic drugs. Upon PKCη knockdown, expression levels of p21, GADD45α, and TAp73 were all increased, whereas expression levels of CDK2, CDK4, CDK6, cyclin E, cyclin B1, and cdc2 were all downregulated. PKCη silencing also activated p38-MAPK, which in turn contributed to the expression of cell cycle arrest-related molecules. These results suggest that siRNA-mediated silencing of PKCη can be a potent tool to complement existing chemotherapy regimens for treating EBV(+) B lymphoma.

Related: Apoptosis CDKN1A Bortezomib Sorafenib (Nexavar)


Weissmueller S, Manchado E, Saborowski M, et al.
Mutant p53 drives pancreatic cancer metastasis through cell-autonomous PDGF receptor β signaling.
Cell. 2014; 157(2):382-94 [PubMed] Article available free on PMC after 10/04/2015 Related Publications
Missense mutations in the p53 tumor suppressor inactivate its antiproliferative properties but can also promote metastasis through a gain-of-function activity. We show that sustained expression of mutant p53 is required to maintain the prometastatic phenotype of a murine model of pancreatic cancer, a highly metastatic disease that frequently displays p53 mutations. Transcriptional profiling and functional screening identified the platelet-derived growth factor receptor b (PDGFRb) as both necessary and sufficient to mediate these effects. Mutant p53 induced PDGFRb through a cell-autonomous mechanism involving inhibition of a p73/NF-Y complex that represses PDGFRb expression in p53-deficient, noninvasive cells. Blocking PDGFRb signaling by RNA interference or by small molecule inhibitors prevented pancreatic cancer cell invasion in vitro and metastasis formation in vivo. Finally, high PDGFRb expression correlates with poor disease-free survival in pancreatic, colon, and ovarian cancer patients, implicating PDGFRb as a prognostic marker and possible target for attenuating metastasis in p53 mutant tumors.

Related: Cancer of the Pancreas Pancreatic Cancer TP53


Polato F, Rusconi P, Zangrossi S, et al.
DRAGO (KIAA0247), a new DNA damage-responsive, p53-inducible gene that cooperates with p53 as oncosuppressor. [Corrected].
J Natl Cancer Inst. 2014; 106(4):dju053 [PubMed] Article available free on PMC after 01/04/2015 Related Publications
BACKGROUND: p53 influences genomic stability, apoptosis, autophagy, response to stress, and DNA damage. New p53-target genes could elucidate mechanisms through which p53 controls cell integrity and response to damage.
METHODS: DRAGO (drug-activated gene overexpressed, KIAA0247) was characterized by bioinformatics methods as well as by real-time polymerase chain reaction, chromatin immunoprecipitation and luciferase assays, time-lapse microscopy, and cell viability assays. Transgenic mice (94 p53(-/-) and 107 p53(+/-) mice on a C57BL/6J background) were used to assess DRAGO activity in vivo. Survival analyses were performed using Kaplan-Meier curves and the Mantel-Haenszel test. All statistical tests were two-sided.
RESULTS: We identified DRAGO as a new p53-responsive gene induced upon treatment with DNA-damaging agents. DRAGO is highly conserved, and its ectopic overexpression resulted in growth suppression and cell death. DRAGO(-/-) mice are viable without macroscopic alterations. However, in p53(-/-) or p53(+/-) mice, the deletion of both DRAGO alleles statistically significantly accelerated tumor development and shortened lifespan compared with p53(-/-) or p53(+/-) mice bearing wild-type DRAGO alleles (p53(-/-), DRAGO(-/-) mice: hazard ratio [HR] = 3.25, 95% confidence interval [CI] = 1.7 to 6.1, P < .001; p53(+/-), DRAGO(-/-) mice: HR = 2.35, 95% CI = 1.3 to 4.0, P < .001; both groups compared with DRAGO(+/+) counterparts). DRAGO mRNA levels were statistically significantly reduced in advanced-stage, compared with early-stage, ovarian tumors, but no mutations were found in several human tumors. We show that DRAGO expression is regulated both at transcriptional-through p53 (and p73) and methylation-dependent control-and post-transcriptional levels by miRNAs.
CONCLUSIONS: DRAGO represents a new p53-dependent gene highly regulated in human cells and whose expression cooperates with p53 in tumor suppressor functions.

Related: Apoptosis Ovarian Cancer


Zhang X, Cao P, Zhai Y, et al.
Association between the p73 G4C14-to-A4T14 polymorphism and risk of nasopharyngeal carcinoma: a case-control and family-based study.
Carcinogenesis. 2014; 35(9):1977-82 [PubMed] Related Publications
p73, a structural and functional homolog of p53, plays an important role in modulating cell cycle control and apoptosis. We examined whether the p73 G4C14-to-A4T14 polymorphism was related to the risk of nasopharyngeal carcinoma (NPC) among Chinese populations. The G4C14-to-A4T14 polymorphism was genotyped in 593 NPC cases and 480 controls, and in 102 NPC trios. Logistic regression analysis and transmission/disequilibrium tests (TDT) were performed to evaluate whether there was an association between the polymorphism and NPC, respectively. Functional analyses were conducted to verify the biological relevance of the polymorphism. We observed that compared with the GC/GC genotype, the genotypes containing AT allele (GC/AT + AT/AT genotypes) were associated with significantly increased susceptibility to NPC [odds ratio (OR) = 1.51; 95% confidence interval (CI) = 1.16-1.95; P = 0.002]. Furthermore, compared with the GC/GC genotype, the GC/AT + AT/AT genotypes were significantly associated with the advanced lymph node metastasis (OR = 1.47; 95% CI = 1.02-2.11; P = 0.041). A significantly greater than expected transmission of the AT allele from heterozygous parents to offspring was also observed (P = 0.049) using the TDT. By using the TdT-mediated dUPT-biotin nick end labeling assay, we observed lower apoptosis in NPC tissues from the AT allele carriers compared with that from non-carriers. Furthermore, the relative TAp73 RNA levels of the AT allele were lower than those of the GC allele in heterozygous cells. Our findings suggest that the p73 G4C14-to-A4T14 polymorphism may play a role in mediating the susceptibility to NPC in Chinese populations.

Related: Apoptosis Nasopharyngeal Cancer Polymorphisms


Shi K, An J, Shan L, et al.
Survivin-2B promotes autophagy by accumulating IKK alpha in the nucleus of selenite-treated NB4 cells.
Cell Death Dis. 2014; 5:e1071 [PubMed] Article available free on PMC after 01/04/2015 Related Publications
Survivin-2B, a known splice variant of survivin, has been reported to promote cell death in some cancer cells, although it keeps prosurvival function in others, and the mechanisms are unclear. In this report, we discovered that selenite, an antitumor agent, switched protective autophagy to apoptosis in NB4 cells. In this process, the level of survivin-2B was decreased and the interaction between IKK alpha and survivin-2B in the nucleus was attenuated, which further led to the decrease of nuclear IKK alpha. As a result, P73, a known transcript factor of UVRAG, was downregulated. Therefore, the expression of UVRAG, one of the initiators of autophagy, was inhibited. The regulatory status of survivin-2B was also proved in NB4 cells after different chemicals' exposure and in other tumor cell lines (Jurkat, HCT116). Finally, experiments in vivo confirmed that the alterations of survivin-2B, IKK alpha, P73 and UVRAG were the same as that in vitro. Taken together, survivin-2B promoted autophagy and further regulated cell death by accumulating and stabilizing IKK alpha in the nucleus.

Related: Leukemia Signal Transduction BIRC5


Guo M, Jia Y, Yu Z, et al.
Epigenetic changes associated with neoplasms of the exocrine and endocrine pancreas.
Discov Med. 2014; 17(92):67-73 [PubMed] Article available free on PMC after 01/04/2015 Related Publications
Early detection and multi-modality curative treatment for pancreatic cancer remain unsatisfactory due to the insufficient understanding of the mechanisms underlying tumor progression. Epigenetic events, including aberrant methylation of tumor suppressor gene promoter regions, may contribute to tumorigenesis involving both the exocrine and endocrine pancreas. Methylation changes of specific gene promoter regions were examined in 48 resected neoplasms of the exocrine and endocrine pancreas, which were obtained as paraffin-embedded tissue samples. The pancreatic neoplasms included acinar cell carcinoma (n=12), adenocarcinoma (n=18), and islet cell tumors (n=18). DNA methylation was determined with a nested methylation-specific PCR (MSP) technique incorporating an initial bisulfite modification of tumor DNA for the promoter regions associated with 14 tumor suppressor genes. In decreasing order, the 6 most frequently methylated genes were: APC 50%, BRCA1 46%, p16INK4a 35%, p15INK4b 35%, RARβ 35%, and p73 33%. Overall, 94% of the tumors had methylation of at least one gene, and methylation of two or more genes was present in 69% of pancreatic tumors. Pancreatic adenocarcinomas had patterns of gene methylation that differed from pancreatic endocrine tumors. These differences were most notable for the APC and hMLH1 genes.

Related: Cancer of the Pancreas Pancreatic Cancer


Missero C, Antonini D
Crosstalk among p53 family members in cutaneous carcinoma.
Exp Dermatol. 2014; 23(3):143-6 [PubMed] Related Publications
Cutaneous squamous cell carcinoma (cSCC) is the second most common human cancer with a frequency increasing worldwide. The risk of developing cSCC has been strongly associated with chronic sun exposure, especially in light skin people. The aim of this viewpoint is to discuss the contribution of the tumor suppressor p53 and its homologues p63 and p73 in the formation and progression of cSCC. Mutations in the p53 gene are early and frequent events in skin carcinogenesis mainly as a consequence of UV light exposure, often followed by loss of function of the second allele. Although rarely mutated in cancer, p63 and p73 play key roles in human cancers, with their truncated isoforms lacking the N-terminal transactivating domain (∆N) being often upregulated as compared to normal tissues. ∆Np63 is abundantly expressed in cSCC, and it is likely to favour tumor initiation and progression. The function of p73 in cSCC is more enigmatic and awaits further studies. Interestingly, an intimate interplay exists between both p53 and p63, and the Notch signalling pathway, often inactivated in cSCC. Here, we summarize our current knowledge about the biological activities of p53 family members in cSCC and propose that integration of their signalling with Notch is key to cSCC formation and progression.

Related: Signal Transduction Skin Cancer TP53


Yong KJ, Milenic DE, Baidoo KE, et al.
Gene expression profiling upon (212) Pb-TCMC-trastuzumab treatment in the LS-174T i.p. xenograft model.
Cancer Med. 2013; 2(5):646-53 [PubMed] Article available free on PMC after 01/04/2015 Related Publications
Recent studies have demonstrated that therapy with (212) Pb-TCMC-trastuzumab resulted in (1) induction of apoptosis, (2) G2/M arrest, and (3) blockage of double-strand DNA damage repair in LS-174T i.p. (intraperitoneal) xenografts. To further understand the molecular basis of the cell killing efficacy of (212) Pb-TCMC-trastuzumab, gene expression profiling was performed with LS-174T xenografts 24 h after exposure to (212) Pb-TCMC-trastuzumab. DNA damage response genes (84) were screened using a quantitative real-time polymerase chain reaction array (qRT-PCR array). Differentially regulated genes were identified following exposure to (212) Pb-TCMC-trastuzumab. These included genes involved in apoptosis (ABL, GADD45α, GADD45γ, PCBP4, and p73), cell cycle (ATM, DDIT3, GADD45α, GTSE1, MKK6, PCBP4, and SESN1), and damaged DNA binding (DDB) and repair (ATM and BTG2). The stressful growth arrest conditions provoked by (212) Pb-TCMC-trastuzumab were found to induce genes involved in apoptosis and cell cycle arrest in the G2/M phase. The expression of genes involved in DDB and single-strand DNA breaks was also enhanced by (212) Pb-TCMC-trastuzumab while no modulation of genes involved in double-strand break repair was apparent. Furthermore, the p73/GADD45 signaling pathway mediated by p38 kinase signaling may be involved in the cellular response, as evidenced by the enhanced expression of genes and proteins of this pathway. These results further support the previously described cell killing mechanism by (212) Pb-TCMC-trastuzumab in the same LS-174T i.p. xenograft. Insight into these mechanisms could lead to improved strategies for rational application of radioimmunotherapy using α-particle emitters.

Related: Apoptosis Signal Transduction Trastuzumab (Herceptin)


He S, Pham MH, Pease M, et al.
A review of epigenetic and gene expression alterations associated with intracranial meningiomas.
Neurosurg Focus. 2013; 35(6):E5 [PubMed] Related Publications
OBJECT: A more comprehensive understanding of the epigenetic abnormalities associated with meningioma tumorigenesis, growth, and invasion may provide useful targets for molecular classification and development of targeted therapies for meningiomas.
METHODS: The authors performed a review of the current literature to identify the epigenetic modifications associated with the formation and/or progression of meningiomas.
RESULTS: Several epigenomic alterations, mainly pertaining to DNA methylation, have been associated with meningiomas. Hypermethylation of TIMP3 inactivates its tumor suppression activity while CDKN2 (p14[ARF]) and TP73 gene hypermethylation and HIST1H1c upregulation interact with the p53 regulation of cell cycle control. Other factors such as HOX, IGF, WNK2, and TGF-β epigenetic modifications allow either upregulation or downregulation of critical pathways for meningioma development, progression, and recurrence.
CONCLUSIONS: Genome-wide methylation profiling demonstrated that global hypomethylation correlates with tumor grades and severity. Identification of additional epigenetic changes, such as histone modification and higher-order chromosomal structure, may allow for a more thorough understanding of tumorigenesis and enable future individualized treatment strategies for meningiomas.


Casadio V, Molinari C, Calistri D, et al.
DNA Methylation profiles as predictors of recurrence in non muscle invasive bladder cancer: an MS-MLPA approach.
J Exp Clin Cancer Res. 2013; 32:94 [PubMed] Article available free on PMC after 01/04/2015 Related Publications
BACKGROUND: Although non muscle invasive bladder cancer (NMIBC) generally has a good long-term prognosis, up to 80% of patients will nevertheless experience local recurrence after the primary tumor resection. The search for markers capable of accurately identifying patients at high risk of recurrence is ongoing. We retrospectively evaluated the methylation status of a panel of 24 tumor suppressor genes (TIMP3, APC, CDKN2A, MLH1, ATM, RARB, CDKN2B, HIC1, CHFR, BRCA1, CASP8, CDKN1B, PTEN, BRCA2, CD44, RASSF1, DAPK1, FHIT, VHL, ESR1, TP73, IGSF4, GSTP1 and CDH13) in primary lesions to obtain information about their role in predicting local recurrence in NMIBC.
METHODS: Formaldehyde-fixed paraffin-embedded (FFPE) samples from 74 patients operated on for bladder cancer were analyzed by methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA): 36 patients had relapsed and 38 were disease-free at the 5-year follow up. Methylation status was considered as a dichotomous variable and genes showing methylation ≥20% were defined as "positive".
RESULTS: Methylation frequencies were higher in non recurring than recurring tumors. A statistically significant difference was observed for HIC1 (P = 0.03), GSTP1 (P = 0.02) and RASSF1 (P = 0.03). The combination of the three genes showed 78% sensitivity and 66% specificity in identifying recurrent patients, with an overall accuracy of 72%.
CONCLUSIONS: Our preliminary data suggest a potential role of HIC1, GSTP1 and RASSF1 in predicting local recurrence in NMIBC. Such information could help clinicians to identify patients at high risk of recurrence who require close monitoring during follow up.

Related: Bladder Cancer Bladder Cancer - Molecular Biology


Park GB, Kim YS, Kim D, et al.
Melphalan-induced apoptosis of EBV-transformed B cells through upregulation of TAp73 and XAF1 and nuclear import of XPA.
J Immunol. 2013; 191(12):6281-91 [PubMed] Related Publications
Melphalan (Mel) is widely used to treat patients with hematologic cancer, including multiple myeloma, but its mechanism of action in EBV-transformed B cells is poorly described. In this study, we demonstrate a novel mechanism by which transcriptionally active p73 (TAp73) induces translocation of X-linked inhibitor of apoptosis protein-associated factor 1 (XAF1) and xeroderma pigmentosum group A (XPA) during apoptosis caused by Mel treatment. We observed that Mel induced significant generation of reactive oxygen species (ROS) and subsequent apoptosis, as well as an early phosphorylation of p38 MAPK that preceded expression of the mitochondria membrane potential disruption-related molecules and the cleavage of caspases. In particular, Mel led to upregulation of TAp73, XAF1, and Puma and induced XPA nuclear import and translocation of Bax into mitochondria. Mel-induced apoptosis was inhibited by pretreatment with the ROS scavenger 4-amino-2,4-pyrrolidine-dicarboxylic acid (APDC) and the p38 MAPK inhibitor SB203580. We supposed that ROS generation might be the first event in Mel-induced apoptosis, because APDC blocked the increase in ROS, p38 MAPK, and TAp73, but SB203580 did not block ROS generation. Moreover, Mel elicited activation of ATR, and APDC inhibited phosphorylation of ATR but not SB203580. APDC and SB203580 completely blocked XPA and Bax translocation. We conclude that Mel promotes TAp73-mediated XAF1 and Puma expression via ROS generation and ATR/p38 MAPK pathway activation, thereby triggering apoptosis. Our results provide evidence of a novel alternate regulatory mechanism of TAp73 and reveal that Mel may be a therapeutic drug for curing EBV-related malignancies.

Related: Apoptosis Melphalan Mitochondrial Mutations in Cancer


Papadogianni D, Soulitzis N, Delakas D, Spandidos DA
Expression of p53 family genes in urinary bladder cancer: correlation with disease aggressiveness and recurrence.
Tumour Biol. 2014; 35(3):2481-9 [PubMed] Related Publications
p53 is a tumour suppressor gene with an established role in the majority of human neoplasias. Its homologues-p63 and p73-cannot be classified as tumour suppressors, since they encode isoforms with oncogenic properties as well. p63 plays a crucial role in epithelial cell differentiation and p73 is essential for neuronal cell development. The p63 and p73 expressions have been investigated in a variety of human tumours including bladder carcinomas; yet, this is the first study to simultaneously analyse the transcriptional levels of all p53 family members in bladder cancer. Using quantitative real-time polymerase chain reaction, we measured the mRNA expression of p53, p63 and p73 in 30 bladder tumours, each paired with adjacent normal tissue. All three studied genes were up-regulated in malignant specimens, p53 by 1.9-fold, p63 by threefold and p73 by twofold, respectively. Further analysis suggested that p63 and p73 act independently of p53 in the malignant bladder epithelium. Statistical analysis revealed that p63 overexpression was more frequent in recurrent bladder tumours (p = 0.045) and in older patients (p = 0.022). Papillary tumours also exhibited abnormal p63 expression (p = 0.026). Finally, p73 was up-regulated in Grade III one-site tumours (p = 0.040). Our results indicate that all p53 family members are abnormally expressed in bladder cancer but do not act synergistically. High levels of p63 correlate with non-muscle invasive tumours with frequent relapses, whereas p73 overexpression is associated with a more aggressive tumour phenotype.

Related: TP53 Bladder Cancer Bladder Cancer - Molecular Biology


Bid HK, Roberts RD, Cam M, et al.
ΔNp63 promotes pediatric neuroblastoma and osteosarcoma by regulating tumor angiogenesis.
Cancer Res. 2014; 74(1):320-9 [PubMed] Article available free on PMC after 01/01/2015 Related Publications
The tumor suppressor gene p53 and its family members p63/p73 are critical determinants of tumorigenesis. ΔNp63 is a splice variant of p63, which lacks the N-terminal transactivation domain. It is thought to antagonize p53-, p63-, and p73-dependent translation, thus blocking their tumor suppressor activity. In our studies of the pediatric solid tumors neuroblastoma and osteosarcoma, we find overexpression of ΔNp63; however, there is no correlation of ΔNp63 expression with p53 mutation status. Our data suggest that ΔNp63 itself endows cells with a gain-of-function that leads to malignant transformation, a function independent of any p53 antagonism. Here, we demonstrate that ΔNp63 overexpression, independent of p53, increases secretion of interleukin (IL)-6 and IL-8, leading to elevated phosphorylation of STAT3 (Tyr-705). We show that elevated phosphorylation of STAT3 leads to stabilization of hypoxia-inducible factor 1α (HIF-1α) protein, resulting in VEGF secretion. We also show human clinical data, which suggest a mechanistic role for ΔNp63 in osteosarcoma metastasis. In summary, our studies reveal the mechanism by which ΔNp63, as a master transcription factor, modulates tumor angiogenesis.

Related: Bone Cancers Angiogenesis and Cancer Neuroblastoma Osteosarcoma TP53


Steder M, Alla V, Meier C, et al.
DNp73 exerts function in metastasis initiation by disconnecting the inhibitory role of EPLIN on IGF1R-AKT/STAT3 signaling.
Cancer Cell. 2013; 24(4):512-27 [PubMed] Related Publications
Dissemination of cancer cells from primary tumors is the key event in metastasis, but specific determinants are widely unknown. Here, we show that DNp73, an inhibitor of the p53 tumor suppressor family, drives migration and invasion of nonmetastatic melanoma cells. Knockdown of endogenous DNp73 reduces this behavior in highly metastatic cell lines. Tumor xenografts expressing DNp73 show a higher ability to invade and metastasize, while growth remains unaffected. DNp73 facilitates an EMT-like phenotype with loss of E-cadherin and Slug upregulation. We provide mechanistic insight toward regulation of LIMA1/EPLIN by p73/DNp73 and demonstrate a direct link between the DNp73-EPLIN axis and IGF1R-AKT/STAT3 activation. These findings establish initiation of the invasion-metastasis cascade via EPLIN-dependent IGF1R regulation as major activity of DNp73.

Related: Melanoma AKT1 IGF1R Signal Transduction Skin Cancer TP53


Wei D, Zhang X, Zou H, et al.
WW domain containing oxidoreductase induces apoptosis in gallbladder-derived malignant cell by upregulating expression of P73 and PUMA.
Tumour Biol. 2014; 35(2):1539-50 [PubMed] Related Publications
Gallbladder cancer (GBC) is one leading cause of cancer-related death worldwide. WW domain-containing oxidoreductase (WWOX) is a tumor suppressor gene which can suppress proliferation of a variety of tumors. However, little was known about the relationships between WWOX and gallbladder cancer. In the current study, we intended to investigate the tumor suppressive role of WWOX in gallbladder malignant cells both in vitro and in vivo, and explore the potential mechanism of tumor toxic function of WWOX. Our results have shown that WWOX triggerred apoptosis in GBC cells and increased the expression of P73 and PUMA in cytoplasm. We also have found that Bax has been upregulated after overexpression of WWOX, whereas, Bcl-2 was downregulated by WWOX. To further validate the results in vivo, we evaluated the tumor suppressive role of WWOX in mouse model of gallbladder cancer. The results have shown that the proliferation of the tumor was inhibited after delivery of WWOX, and the expressions of P73 and PUMA were upregulated in target tissues. The mice models administrated with WWOX have shown better prognosis than mice in negative control groups. The results from our study indicated that WWOX could be used as a therapeutic agent in the gene therapy of gallbladder cancer.

Related: Apoptosis Gallbladder Cancer


Płuciennik E, Kośla K, Wójcik-Krowiranda K, et al.
The WWOX tumor suppressor gene in endometrial adenocarcinoma.
Int J Mol Med. 2013; 32(6):1458-64 [PubMed] Related Publications
Endometrial cancer is a lethal malignancy, the causes of which remain to be determined. The aim of the present study, carried out on tumor samples from 79 patients, was to evaluate the role of the WWOX tumor suppressor gene in endometrial adenocarcinoma. The expression levels of WWOX and its protein content were assessed in normal endometrium and cancer samples. Quantitative PCR was used to assess the correlation between the expression levels of WWOX and the genes involved in the proliferation (MKI67), apoptosis (BAX, BCL2), signal transduction (EGFR), cell cycle (CCNE1, CCND1), cell adhesion (CDH1) and transcription regulation (TP73, NCOR1). The relationship between loss of hetero-zygosity (LOH) and WWOX mRNA levels was also investigated using high resolution melting. Results of the present study demonstrated a positive correlation of WWOX expression with BCL2 and CCND1 and a negative correlation with BAX, CDH1, NCOR1 and BCL2/BAX ratio. The results also showed that loss of heterozygosity at two analyzed loci of the WWOX gene is frequent in patients with endometrial cancer and that WWOX expression levels are lower in tumor samples than in normal tissue. In conclusion, WWOX may be involved in endometrial cancer.

Related: Endometrial (Uterus) Cancer Endometrial Cancer


Guerrieri F, Piconese S, Lacoste C, et al.
The sodium/iodide symporter NIS is a transcriptional target of the p53-family members in liver cancer cells.
Cell Death Dis. 2013; 4:e807 [PubMed] Article available free on PMC after 01/01/2015 Related Publications
Thyroid iodide accumulation via the sodium/iodide symporter (NIS; SLC5A5) has been the basis for the longtime use of radio-iodide in the diagnosis and treatment of thyroid cancers. NIS is also expressed, but poorly functional, in some non-thyroid human cancers. In particular, it is much more strongly expressed in cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC) cell lines than in primary human hepatocytes (PHH). The transcription factors and signaling pathways that control NIS overexpression in these cancers is largely unknown. We identified two putative regulatory clusters of p53-responsive elements (p53REs) in the NIS core promoter, and investigated the regulation of NIS transcription by p53-family members in liver cancer cells. NIS promoter activity and endogenous NIS mRNA expression are stimulated by exogenously expressed p53-family members and significantly reduced by member-specific siRNAs. Chromatin immunoprecipitation analysis shows that the p53-REs clusters in the NIS promoter are differentially occupied by the p53-family members to regulate basal and DNA damage-induced NIS transcription. Doxorubicin strongly induces p53 and p73 binding to the NIS promoter, leading to an increased expression of endogenous NIS mRNA and protein in HCC and CCA cells, but not in PHH. Silencing NIS expression reduced doxorubicin-induced apoptosis in HCC cells, pointing to a possible role of a p53-family-dependent expression of NIS in apoptotic cell death. Altogether, these results indicate that the NIS gene is a direct target of the p53 family and suggests that the modulation of NIS by DNA-damaging agents is potentially exploitable to boost NIS upregulation in vivo.

Related: Apoptosis Doxorubicin Liver Cancer TP53


Puri N, Pitman RT, Mulnix RE, et al.
Non-small cell lung cancer is susceptible to induction of DNA damage responses and inhibition of angiogenesis by telomere overhang oligonucleotides.
Cancer Lett. 2014; 343(1):14-23 [PubMed] Related Publications
Exposure of the telomere overhang acts as a DNA damage signal, and exogenous administration of an 11-base oligonucleotide homologous to the 3'-telomere overhang sequence (T-oligo) mimics the effects of overhang exposure by inducing senescence and cell death in non-small cell lung cancer (NSCLC) cells, but not in normal bronchial epithelial cells. T-oligo-induced decrease in cellular proliferation in NSCLC is likely directed through both p53 and its homolog, p73, with subsequent induction of senescence and expression of senescence-associated proteins, p21, p33(ING), and p27(Kip1) both in vivo and in vitro. Additionally, T-oligo decreases tumor size and inhibits angiogenesis through decreased VEGF signaling and increased TSP-1 expression.

Related: Non-Small Cell Lung Cancer CDKN1A CDKN1B Angiogenesis and Cancer Signal Transduction VEGFA ING1


Saha MN, Jiang H, Yang Y, et al.
PRIMA-1Met/APR-246 displays high antitumor activity in multiple myeloma by induction of p73 and Noxa.
Mol Cancer Ther. 2013; 12(11):2331-41 [PubMed] Related Publications
Targeting p53 by the small-molecule PRIMA-1(Met)/APR-246 has shown promising preclinical activity in various cancer types. However, the mechanism of PRIMA-1(Met)-induced apoptosis is not completely understood and its effect on multiple myeloma cells is unknown. In this study, we evaluated antitumor effect of PRIMA-1(Met) alone or its combination with current antimyeloma agents in multiple myeloma cell lines, patient samples, and a mouse xenograft model. Results of our study showed that PRIMA-1(Met) decreased the viability of multiple myeloma cells irrespective of p53 status, with limited cytotoxicity toward normal hematopoietic cells. Treatment of multiple myeloma cells with PRIMA-1(Met) resulted in induction of apoptosis, inhibition of colony formation, and migration. PRIMA-1(Met) restored wild-type conformation of mutant p53 and induced activation of p73 upregulating Noxa and downregulating Mcl-1 without significant modulation of p53 level. siRNA-mediated silencing of p53 showed a little effect on apoptotic response of PRIMA-1(Met), whereas knockdown of p73 led to substantial attenuation of apoptotic activity in multiple myeloma cells, indicating that PRIMA-1(Met)-induced apoptosis is, at least in part, p73-dependent. Importantly, PRIMA-1(Met) delayed tumor growth and prolonged survival of mice bearing multiple myeloma tumor. Furthermore, combined treatment of PRIMA-1(Met) with dexamethasone or doxorubicin displayed synergistic effects in both multiple myeloma cell lines and primary multiple myeloma samples. Consistent with our in vitro observations, cotreatment with PRIMA-1(Met) and dexamethasone resulted in enhanced antitumor activity in vivo. Our study for the first time shows antimyeloma activity of PRIMA-1(Met) and provides the rationale for its clinical evaluation in patients with multiple myeloma, including the high-risk group with p53 mutation/deletion.

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Bahnassy AA, Zekri AR, Salem SE, et al.
Differential expression of p53 family proteins in colorectal adenomas and carcinomas: Prognostic and predictive values.
Histol Histopathol. 2014; 29(2):207-16 [PubMed] Related Publications
BACKGROUND: We studied the contribution of p53 family proteins and their isoforms to the development and progression of colorectal carcinoma in relation to VEGF.
METHODS: p53, p63, p73 and VEGF proteins were assessed in 45 colorectal adenomas (CRAs), 80 carcinomas (CRCs) and 36 normal colonic tissue samples (NCT) by immunohistochemistry. Different p63 and p73 isoforms were assessed by RT-PCR. Aberrant protein and RNA expressions were correlated to patients' characteristics, disease free and overall survival (DFS and OS).
RESULTS: p53, p63, p73 and VEGF proteins were detected in 22.2%, 73.3%, 33.3%, 46.7% CRAs; in 68.8%, 38.8%, 62.5%, 62.5% CRCs and 16.7%, 83.3%; 13.9%, 41.7% NCT (p<0.05 except for VEGF). Commonest isoforms were TAp63α, ΔNp63, TAp73α in CRA and ΔNp63, TAp63α, ΔNp73, TAp73β in CRC. Significant correlations were found between aggressive tumor phenotypes and aberrations in p73, p53, p63, VEGF. DFS correlated with advanced stage, p73 and VEGF aberrations. While advanced stage, positive lymph nodes, p73 and p53 correlated with OS. Prognosis was worse in patients with aberrant p63 and p73 than in those with normal p63 and p73 expression regardless of p53 gene status (p⟨0.05).
CONCLUSIONS: p53 family proteins and VEGF play a pivotal role in colorectal carcinogenesis. p53 prognostic potential is augmented by p73 and p63 aberrations indicating a synergistic effect between the three family members. Nodal status, stage, p73, VEGF and p53 could be used as predictors of DFS and OS.

Related: Colorectal (Bowel) Cancer TP53 VEGFA


Soldevilla B, Millán CS, Bonilla F, Domínguez G
The TP73 complex network: ready for clinical translation in cancer?
Genes Chromosomes Cancer. 2013; 52(11):989-1006 [PubMed] Related Publications
TP73 is a member of the TP53 family, whose deregulated expression has been reported in a wide variety of cancers and linked to patients' outcome. The fact that TP73 encodes a complex number of isoforms (TAp73 and ΔTAp73) with opposing functions and the cross-talk with other members of the family (TP53 and TP63) make it difficult to determine its clinical relevance. Here, we review the molecular mechanisms driving TAp73 and ΔTAp73 expression and how these variants inhibit or promote carcinogenesis. We also highlight the intricate interplay between TP53 family members. In addition, we comment on current pharmacological approaches targeting the TP73 pathway and those affecting the TAp73/ΔTAp73 ratio. Finally, we discuss the current data available in the literature that provide evidence on the role of TP73 variants in predicting prognosis. To date, most of the studies that evaluate the status levels of TP73 isoforms have been based on limited-size series. Despite this limitation, these publications highlight the correlation between high levels of the oncogenic forms and failure to respond to chemotherapy and/or shorter survival. Finally, we emphasize the need for studies to evaluate the significance of combining the deregulation of various members of the TP53 family in order to define patient outcome or their responsiveness to specific therapies.

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Jacobs DI, Mao Y, Fu A, et al.
Dysregulated methylation at imprinted genes in prostate tumor tissue detected by methylation microarray.
BMC Urol. 2013; 13(1):37 [PubMed] Article available free on PMC after 01/01/2015 Related Publications
BACKGROUND: Imprinting is an important epigenetic regulator of gene expression that is often disrupted in cancer. While loss of imprinting (LOI) has been reported for two genes in prostate cancer (IGF2 and TFPI2), disease-related changes in methylation across all imprinted gene regions has not been investigated.
METHODS: Using an Illumina Infinium Methylation Assay, we analyzed methylation of 396 CpG sites in the promoter regions of 56 genes in a pooled sample of 12 pairs of prostate tumor and adjacent normal tissue. Selected LOI identified from the array was validated using the Sequenom EpiTYPER assay for individual samples and further confirmed by expression data from publicly available datasets.
RESULTS: Methylation significantly increased in 52 sites and significantly decreased in 17 sites across 28 unique genes (P < 0.05), and the strongest evidence for loss of imprinting was demonstrated in tumor suppressor genes DLK1, PLAGL1, SLC22A18, TP73, and WT1. Differential expression of these five genes in prostate tumor versus normal tissue using array data from a publicly available database were consistent with the observed LOI patterns, and WT1 hypermethylation was confirmed using quantitative DNA methylation analysis.
CONCLUSIONS: Together, these findings suggest a more widespread dysregulation of genetic imprinting in prostate cancer than previously reported and warrant further investigation.

Related: Prostate Cancer


Santoni M, Amantini C, Morelli MB, et al.
Pazopanib and sunitinib trigger autophagic and non-autophagic death of bladder tumour cells.
Br J Cancer. 2013; 109(4):1040-50 [PubMed] Article available free on PMC after 01/01/2015 Related Publications
BACKGROUND: Tyrosine kinase inhibitors (TKI) such as sunitinib and pazopanib display their efficacy in a variety of solid tumours. However, their use in therapy is limited by the lack of evidence about the ability to induce cell death in cancer cells. Our aim was to evaluate cytotoxic effects induced by sunitinib and pazopanib in 5637 and J82 bladder cancer cell lines.
METHODS: Cell viability was tested by MTT assay. Autophagy was evaluated by western blot using anti-LC3 and anti-p62 antibodies, acridine orange staining and FACS analysis. Oxygen radical generation and necrosis were determined by FACS analysis using DCFDA and PI staining. Cathepsin B activation was evaluated by western blot and fluorogenic Z-Arg-Arg-AMC peptide. Finally, gene expression was performed using RT-PCR Profiler array.
RESULTS: We found that sunitinib treatment for 24 h triggers incomplete autophagy, impairs cathepsin B activation and stimulates a lysosomal-dependent necrosis. By contrast, treatment for 48 h with pazopanib induces cathepsin B activation and autophagic cell death, markedly reversed by CA074-Me and 3-MA, cathepsin B and autophagic inhibitors, respectively. Finally, pazopanib upregulates the α-glucosidase and downregulates the TP73 mRNA expression.
CONCLUSION: Our results showing distinct cell death mechanisms activated by different TKIs, provide the biological basis for novel molecularly targeted approaches.

Related: Transitional Cell Cancer of the Renal Pelvis and Ureter Bladder Cancer Bladder Cancer - Molecular Biology Sunitinib (Sutent) Pazopanib (Votrient)


Nekulova M, Holcakova J, Nenutil R, et al.
Characterization of specific p63 and p63-N-terminal isoform antibodies and their application for immunohistochemistry.
Virchows Arch. 2013; 463(3):415-25 [PubMed] Related Publications
The TP63 gene gives rise to protein isoforms with different properties and functions due to the presence (TAp63) or absence (ΔNp63) of an N-terminal p53-like transactivation domain. Immunohistochemistry for p63 has clinical value for certain tumour types, but investigations have been hampered by a lack of well characterized antibodies and the inability to discriminate between these N-terminal isoforms with opposite functional properties. We have extensively characterized a series of monoclonal antibodies to recombinant human TAp63 and two commercial p63 monoclonals by Western blot, immunostaining and phage display epitope mapping. Twenty-eight of 29 (96.6 %) novel monoclonals that recognized all p63 isoforms showed substantial cross-reactivity with p73, as did the commercial antibody, 4A4. One novel clone, PANp63-6.1, showed slight cross-reaction with p73 by Western blotting but not immunohistochemistry and the SFI-6 monoclonal did not cross-react with p73 or p53. Phage display revealed that the PANp63-6.1 epitope has one amino acid difference between p63 and p73, the 4A4 epitope is identical in both, whereas the SFI-6 epitope is unique to p63, accounting for these findings. We also produced and characterized a TAp63-specific clone that does not recognize p53 or p73, and we prepared polyclonal sera specific for ΔNp63 isoforms. Immunohistochemistry demonstrated that TAp63 is expressed in a variety of epithelial and other cell types during development, often in a converse pattern to ΔNp63, but has a very limited expression in normal adult tissues and is independent of ΔNp63. TAp63 was expressed in 17.6 % of squamous cancers of cervix that expressed p63, unlike normal cervix where TAp63 was not expressed. TAp63 did not associate with proliferative index, but cervical carcinomas with TAp63 expression showed improved survival. These data highlight the need for rigorous antibody characterization and indicate that p63-isoform identification may improve the clinical value of p63 expression analyses.

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Chen C, Hu SY, Luo DQ, et al.
Potential antitumor agent from the endophytic fungus Pestalotiopsis photiniae induces apoptosis via the mitochondrial pathway in HeLa cells.
Oncol Rep. 2013; 30(4):1773-81 [PubMed] Related Publications
4-(3',3'-Dimethylallyloxy)-5-methyl-6-methoxy-phthalide (DMMP) has previously been isolated from the endophytic fungus Pestalotiopsis photiniae. Although the cytotoxic activities of DMMP have been reported, little is known concerning the molecular mechanism of its cytotoxic effect. In the present study, we investigated the effect of DMMP on the growth of several types of cancer cell lines and investigated the mechanism of its antiproliferative effect. DMMP caused the growth inhibition of human cancer lines HeLa, MCF7 and MDA-MB-231, but had little antiproliferative effect on MRC5 normal lung cells. DMMP also significantly caused cell cycle arrest in the G1 phase and upregulated the cyclin-dependent kinase inhibitor p27KIPI protein in the HeLa cells. Moreover DMMP was able to induce marked nuclear apoptotic morphology in HeLa cells. DMMP induced apoptosis and loss of mitochondrial membrane potential (ΔΨm) in the HeLa cells. Although the activated forms of caspase-9 and -3 in HeLa cells were detected, pretreatment with caspase inhibitors (Ac-DEVD-CHO and Z-VAD-FMK) failed to attenuate DMMP-induced cell death. In addition, protein levels of the p53 family members, p53 and p73, were upregulated, and DMMP significantly increased the mRNA expression of pro-apoptotic Bcl-2 family genes (PUMA, NOXA, Bax, Bad and Bim). HPV E6-E7 mRNA levels were reduced. In conclusion, DMMP demonstrates potential for use in the treatment of cervical cancer.

Related: Apoptosis CASP3 CDKN1B Mitochondrial Mutations in Cancer TP53 Cervical Cancer BAD PMAIP1


Yeo CI, Ooi KK, Akim AM, et al.
The influence of R substituents in triphenylphosphinegold(I) carbonimidothioates, Ph3PAu[SC(OR)=NPh] (R=Me, Et and iPr), upon in vitro cytotoxicity against the HT-29 colon cancer cell line and upon apoptotic pathways.
J Inorg Biochem. 2013; 127:24-38 [PubMed] Related Publications
The Ph3PAu[SC(OR)=NPh], R=Me (1), Et (2) and iPr (3), compounds are significantly cytotoxic to the HT-29 cancer cell line with 1 being the most active. Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis is demonstrated and both the extrinsic and intrinsic pathways of apoptosis have been shown to occur. Compound 1 activates the p73 gene, whereas each of 2 and 3 activates the p53 gene. An additional apoptotic mechanism is exhibited by 2, that is, via the JNK/MAP pathway.

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Okada T, Nakamura M, Nishikawa J, et al.
Identification of genes specifically methylated in Epstein-Barr virus-associated gastric carcinomas.
Cancer Sci. 2013; 104(10):1309-14 [PubMed] Related Publications
We studied the comprehensive DNA methylation status in the naturally derived gastric adenocarcinoma cell line SNU-719, which was infected with the Epstein-Barr virus (EBV) by methylated CpG island recovery on chip assay. To identify genes specifically methylated in EBV-associated gastric carcinomas (EBVaGC), we focused on seven genes, TP73, BLU, FSD1, BCL7A, MARK1, SCRN1, and NKX3.1, based on the results of methylated CpG island recovery on chip assay. We confirmed DNA methylation of the genes by methylation-specific PCR and bisulfite sequencing in SNU-719. The expression of the genes, except for BCL7A, was upregulated by a combination of 5-Aza-2'-deoxycytidine and trichostatin A treatment in SNU-719. After the treatment, unmethylated DNA became detectable in all seven genes by methylation-specific PCR. We verified DNA methylation of the genes in 75 primary gastric cancer tissues from 25 patients with EBVaGC and 50 EBV-negative patients who were controls. The methylation frequencies of TP73, BLU, FSD1, BCL7A, MARK1, SCRN1, and NKX3.1 were significantly higher in EBVaGC than in EBV-negative gastric carcinoma. We identified seven genes with promoter regions that were specifically methylated in EBVaGC. Inactivation of these genes may suppress their function as tumor suppressor genes or tumor-associated antigens and help to develop and maintain EBVaGC.

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Fernández-Pérez MP, Montenegro MF, Sáez-Ayala M, et al.
Suppression of antifolate resistance by targeting the myosin Va trafficking pathway in melanoma.
Neoplasia. 2013; 15(7):826-39 [PubMed] Article available free on PMC after 01/01/2015 Related Publications
Human melanoma is a significant clinical problem. As most melanoma patients relapse with lethal drug-resistant disease, understanding and preventing mechanism(s) of resistance is one of the highest priorities to improve melanoma therapy. Melanosomal sequestration and the cellular exportation of cytotoxic drugs have been proposed to be important melanoma-specific mechanisms that contribute to multidrug resistance in melanoma. Concretely, we found that treatment of melanoma with methotrexate (MTX) altered melanogenesis and accelerated the exportation of melanosomes; however, the cellular and molecular processes by which MTX is trapped into melanosomes and exported out of cells have not been elucidated. In this study, we identified myosin Va (MyoVa) as a possible mediator of these cellular processes. The results demonstrated that melanoma treatment with MTX leads to Akt2-dependent MyoVa phosphorylation, which enhances its ability to interact with melanosomes and accelerates their exportation. To understand the mechanism(s) by which MTX activates Akt2, we examined the effects of this drug on the activity of protein phosphatase 2A, an Akt inhibitor activated by the methylation of its catalytic subunit. Taken together, this study identified a novel trafficking pathway in melanoma that promotes tumor resistance through Akt2/MyoVa activation. Because of these findings, we explored several MTX combination therapies to increase the susceptibility of melanoma to this drug. By avoiding MTX exportation, we observed that the E2F1 apoptotic pathway is functional in melanoma, and its induction activates p73 and apoptosis protease-activating factor 1 following a p53-autonomous proapoptotic signaling event.

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England B, Huang T, Karsy M
Current understanding of the role and targeting of tumor suppressor p53 in glioblastoma multiforme.
Tumour Biol. 2013; 34(4):2063-74 [PubMed] Related Publications
Glioblastoma multiforme (GBM) is the most common primary malignancy in the brain and confers a uniformly poor prognosis. Despite decades of research on the topic, limited progress has been made to improve the poor survival associated with this disease. GBM arises de novo (primary GBM) or via dedifferentiation of lower grade glioma (secondary GBM). While distinct mutations are predominant in each subtype, alterations of tumor suppressor p53 are the most common, seen in 25-30 % of primary GBM and 60-70 % of secondary GBM. Various roles of p53 that protect against neoplastic transformation include modulation of cell cycle, DNA repair, apoptosis, senescence, angiogenesis, and metabolism, resulting in an extremely complex signaling network. Mutations of p53 in GBM are most common in the DNA-binding domain, namely within six hotspot mutation sites (codons 175, 245, 248, 249, 273, and 282). These alterations generally result in loss-of-function, gain-of-function, and dominant-negative mutational effects for p53, however, the distinct effect of these mutation types in GBM pathogenesis remain unclear. Signaling alterations downstream from p53 (e.g., MDM2, MDM4, INK4/ARF), p53 isoforms (e.g., p63, p73), and microRNAs (e.g., miR-34) also play critical roles in modulating the p53 pathway. Despite novel mouse models of GBM showing that p53 combined with other mutation generate tumors de novo, the role of p53 as a molecular marker of GBM remains controversial with most studies failing to show an association with prognosis. Regarding treatment in GBM, p53 targeted-gene therapy and vaccinations have reached phase I clinical trials while therapeutic drugs are still in preclinical development. This review aims to discuss the most recent findings regarding the impact of p53 mutations on GBM pathogenesis, prognosis, and treatment.

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Cite this page: Cotterill SJ. TP73, Cancer Genetics Web: http://www.cancerindex.org/geneweb/TP73.htm Accessed: date

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