Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemiological evidence suggests that flavonoids may play an important role in the decreased risk of chronic diseases associated with a diet rich in plant-derived foods. Flavonoids are also common constituents of plants used in traditional medicine to treat a wide range of diseases. The purpose of this article is to summarize the distribution and biological activities of one of the most common flavonoids: luteolin. This flavonoid and its glycosides are widely distributed in the plant kingdom; they are present in many plant families and have been identified in Bryophyta, Pteridophyta, Pinophyta and Magnoliophyta. Dietary sources of luteolin include, for instance, carrots, peppers, celery, olive oil, peppermint, thyme, rosemary and oregano. Preclinical studies have shown that this flavone possesses a variety of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial and anticancer activities. The ability of luteolin to inhibit angiogenesis, to induce apoptosis, to prevent carcinogenesis in animal models, to reduce tumor growth in vivo and to sensitize tumor cells to the cytotoxic effects of some anticancer drugs suggests that this flavonoid has cancer chemopreventive and chemotherapeutic potential. Modulation of ROS levels, inhibition of topoisomerases I and II, reduction of NF-kappaB and AP-1 activity, stabilization of p53, and inhibition of PI3K, STAT3, IGF1R and HER2 are possible mechanisms involved in the biological activities of luteolin.
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PMID:Distribution and biological activities of the flavonoid luteolin. 1914 59

Cetuximab (Erbitux) is an anti-epidermal growth factor receptor (EGFR) monoclonal antibody whose activity is related to the inhibition of EGFR downstream signaling pathways. P53 and phosphatase and tensin homologue deleted on chromosome 10 (PTEN) have been reported to control the functionality of PI3K/AKT signaling. In this study we evaluated whether reintroducing P53 using non-viral gene transfer enhances PTEN-mediated inhibition of PI3K/AKT signaling by cetuximab in PC3 prostate adenocarcinoma cell line bearing p53 and pten mutations. Signaling phosphoproteins expression was analyzed using Bio-Plex phosphoprotein array and western blot. Apoptosis induction was evaluated from BAX expression, caspase-3 activation and DNA fragmentation analyses. The results presented show that p53 and pten gene transfer additionally mediated cell growth inhibition and apoptosis induction by restoral of signaling functionality, which enabled the control of PI3K/AKT and MAPKinase signaling pathways by cetuximab in PC3 cells. These results highlight the interest of the analysis of signaling phosphoproteins expression as molecular predictive markers for response to cetuximab and show that p53 and pten mutations could be key determinants of cell response to cetuximab through the functional impact of these mutations on cell signaling.
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PMID:P53 and PTEN expression contribute to the inhibition of EGFR downstream signaling pathway by cetuximab. 1916 35

Cellular senescence is a potent anti-cancer mechanism controlled by tumor suppressor genes, particularly p53 and pRb, which is characterized by the irreversible loss of proliferation. Senescence induced by DNA damage, oncogenic stimulation, or excessive mitogenic input, serves as a barrier that counteracts cancer progression. Emerging evidence in cellular and in in vivo models revealed the involvement of additional signaling players in senescence, including PML, CK2, Bcl-2, PI3K effectors such as Rheb, Rho small GTPases, and cytokines. Recent studies have also implicated protein kinase C (PKC) isozymes as modulators of senescence phenotypes and showed that phorbol esters, widely used PKC activators, can induce senescence in a number of cancer cells. These novel findings suggest a complex array of cross-talks between senescence pathways and may have significant implications in cancer therapy.
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PMID:Hallmarks for senescence in carcinogenesis: novel signaling players. 1916 23

The PTEN (phosphatase and tensin homolog deleted on chromosome ten) tumor suppressor gene is mutated in a wide range of malignancies and recent studies have demonstrated that PTEN prevents tumorigenesis through multiple mechanisms. PTEN functions as a plasma-membrane lipid phosphatase that antagonizes the PI3K (phosphoinositide 3 kinase)-AKT pathway. PTEN physically and genetically interacts with the central genome guardian p53. PTEN also associates with the centromeric protein CENP-C to maintain centromere integrity and suppresses chromosomal instability from DNA double-strand breaks (DSBs) through transcriptional regulation of Rad51 (radiosensitive yeast mutant 51). Moreover PTEN controls the growth and proliferation of haematopoietic stem cells (HSC) and restrains cells from leukemia in an mTOR (mammalian target of rapamycin) dependent manner. Thus, restoring PTEN functions in cancer cells directly or indirectly holds great promise for cancer therapy.
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PMID:PTEN mutation: many birds with one stone in tumorigenesis. 1918 42

Endometrial cancer is the most common gynecological malignancy in developed countries and represents the eighth leading cause of cancer related death in women. The growing incidence of endometrial cancer leads scientists and oncologists to identify effective preventive measures and also molecular markers for diagnosis and prognosis. Chemotherapy and hormone therapy is the mainstay treatment option for advanced and recurrent endometrial cancer and response to therapy is one of the most important factor which favors prognosis and overall survival. In recent years, there have been major advances in the treatment of patients with endometrial cancer. Despite advances made in the treatment of this cancer, the overall survival of patients has not significantly improved because considerable number of patients harbor tumor refractory to these therapies and the majority of the initially responsive tumors become refractory to treatments. Therefore, determination of sensitivity/resistance is becoming increasingly important for individualization of endometrial cancer therapy. The aim of this review is to present the existing knowledge about the molecular markers that could play a crucial role in determining resistance to chemo- and hormone therapy. Extensive literature search for the cell signaling pathways and factors responsible for chemoresistance have been performed and reviewed. Several recent studies suggest that deregulations in the apoptotic pathways (such as p53, Fas/FasL, Bcl-2 family proteins, inhibitor of apoptosis proteins), survival pathways (PI3K/AKT, MAPK), hormone receptor signaling pathways (progesterone receptor), Cyclooxygenase-2 and Her-2 are considered as key factors involved in the onset and maintenance of therapeutic resistance, suggesting that resistance is a multi-factorial phenomenon.
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PMID:Resistance to chemotherapy and hormone therapy in endometrial cancer. 1919 80

Hepatocellular carcinoma (HCC) is a major health problem, being the sixth most common cancer world-wide. Dysregulation of the balance between proliferation and cell death represents a pro-tumorigenic principle in human hepatocarcinogenesis. This review updates the recent relevant contributions reporting molecular alterations for HCC that induce an imbalance in the regulation of apoptosis. Alterations in the expression and/or activation of p53 are frequent in HCC cells, which confer on them resistance to chemotherapeutic drugs. Many HCCs are also insensitive to apoptosis induced either by death receptor ligands, such as FasL or TRAIL, or by transforming growth factor-beta (TGF-beta). Although the expression of some pro-apoptotic genes is decreased, the balance between death and survival is dysregulated in HCC mainly due to overactivation of anti-apoptotic pathways. Indeed, some molecules involved in counteracting apoptosis, such as Bcl-X(L), Mcl-1, c-IAP1, XIAP or survivin are over-expressed in HCC cells. Furthermore, some growth factors that mediate cell survival are up-regulated in HCC, as well as the molecules involved in the machinery responsible for cleavage of their pro-forms to an active peptide. The expression and/or activation of the JAK/STAT, PI3K/AKT and RAS/ERKs pathways are enhanced in many HCC cells, conferring on them resistance to apoptotic stimuli. Finally, recent evidence indicates that inflammatory processes, as well as the epithelial-mesenchymal transitions that occur in HCC cells to facilitate their dissemination, are related to cell survival. Therefore, therapeutic strategies to selectively inhibit anti-apoptotic signals in liver tumor cells have the potential to provide powerful tools to treat HCC.
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PMID:Dysregulation of apoptosis in hepatocellular carcinoma cells. 1919 51

The transcriptional regulator TBX2 is genetically amplified in several cancers and has, in addition, important roles in development. In carcinogenesis, TBX2 regulates the cell cycle by suppressing the expression of cyclin-dependent kinase (CDK) inhibitors and destabilizes p53 by suppressing expression of ARF. In embryogenesis, however, TBX2 appears to act independently of the cell cycle or p53 and is regulated by growth factors. Tumorigenic functions of TBX2 that are independent of p53 or cell cycle regulation remain poorly understood. Here we used SW13 carcinoma cells which express inactive p53 and have no detectable p16 or p21 CDK-inhibitors as a model to study these functions. Expression of TBX2 in SW13 cells had no effect on the cell cycle but promoted anchorage-independence and increased resistance to apoptotic stimuli including UV-irradiation, the cytotoxic drug doxorubicin and lethal endoplasmic-reticulum stress. This is a cell type-dependent effect as TBX2 overexpression in PANC1 pancreatic cancer cells which are p53-negative has no effect on colony formation or survival after irradiation. Mechanistically, in SW13 cells, TBX2 overexpression strongly reduced the activation of caspase 3, 8 and 9 following UV-irradiation but without altering the expression of the corresponding procaspases. There were, however, dramatic and specific decreases in the expression of procaspases 1 and 4. The expression of the inhibitor of apoptosis, cIAP2/BIRC3, increased in TBX2-overexpressing cells. TBX2 was upregulated in a PI3K-dependent manner by growth factors that are tumorigenic for SW13. Inhibition of Akt phosphorylation abrogates upregulation of TBX2 by FGF-4. Our findings identify TBX2 as a cell type-dependent survival factor under a p53-negative background, and are indicative of a potentially wider role for TBX2 in carcinogenesis than hitherto described.
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PMID:Expression of TBX2 promotes anchorage-independent growth and survival in the p53-negative SW13 adrenocortical carcinoma. 1921 23

The status of p53 and the phosphatidylinositol 3-kinase-AKT (PI3K-AKT) signaling pathway was investigated in 132 endometrial carcinomas, including endometrioid endometrial carcinomas, non-endometrioid endometrial carcinomas, and mixed endometrioid adenocarcinomas-non-endometrioid adenocarcinomas. Results were compared with the clinicopathologic parameters associated with prognosis, patients' follow-up, and other genetic alterations found frequently in these tumors. Molecular genetic differences between low-grade and high-grade endometrioid adenocarcinomas were encountered; ie, PIK3CA mutations were detected in 26 and 34% of cases, respectively. We found p53 alterations in only 17% of high-grade endometrioid adenocarcinomas. In contrast, non-endometrioid adenocarcinomas had a higher frequency of p53 alterations (54%), PIK3CA mRNA overexpression (45%), and exon 20 PIK3CA mutations (21%). In the mixed endometrioid adenocarcinomas-non-endometrioid adenocarcinomas, the most frequent alterations were p53 (50%) and PIK3CA (44%) mutations, followed by PTEN mutations (38%). In some cases, p53 and PIK3CA alterations coexisted, but they rarely coexisted with the PTEN mutations. Our findings suggest that the PIK3CA mutations are frequent events in endometrial carcinomas of any histological type. However, location of the PIK3CA mutations, either in exon 9 or exon 20, varies significantly according to the histologic grade and type of carcinoma. Carcinomas with exon 20 PIK3CA mutations or PIK3CA mRNA overexpression were often high-grade carcinomas associated with myometrial invasion; in contrast, tumors that carried exon 9 mutations were more likely to be low-grade carcinomas. The Kaplan-Meier analysis suggested that p53 alterations (strong immunoexpression or mutations) conferred a worse prognosis (P=0.000). Although alterations in the PI3K-AKT signaling pathway alone did not influence overall survival, patients with deregulated PI3K-AKT pathway (PIK3CA and/or PTEN alterations) and p53 alterations had shorter survival (P=0.000) than patients with only p53 alterations. Such a relationship was lost when we considered exon 9 PIK3CA mutations. Our results contribute to further characterize the molecular genetic model for endometrial carcinogenesis.
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PMID:Concomitant PI3K-AKT and p53 alterations in endometrial carcinomas are associated with poor prognosis. 1923 38

Transferrin receptor (CD71) is involved in the cellular uptake of iron and is expressed on cells with high proliferation. It may be implicated in promoting the growth of endocrine resistant phenotypes within ER+/luminal-like breast cancer. We used a panel of in vitro cell models of acquired resistance to tamoxifen (TAMR), Faslodex (FASR) or severe oestrogen deprivation (MCF-7X) and the ER+ luminal MCF-7 parental line to determine CD71 mRNA expression and to study transferrin (Tf) effects on in vitro tumour growth and its inhibition. Furthermore, CD71 protein expression was assessed in a well-characterized series of patients with invasive breast carcinoma using tissue microarrays. Our results demonstrated a striking elevation of CD71 in all cell models of acquired resistance. Exogenous Tf significantly promoted growth in MCF-7-X and MCF-7 cells but more so in MCF-7-X; this growth was significantly reduced by Faslodex (FAS) or a phosphoinositide-3 kinase inhibitor (LY294002). Increased CD71 expression was associated with poor NPI score, tumour proliferation, basal CKs, p53, EGFR, HER2, steroid receptor negativity and shortened breast cancer specific survival (P < 0.001). On multivariate analysis, CD71 was found to be an independent prognostic factor in the ER+ cohort of patients. In conclusion, therapies of current interest in breast cancer (e.g. FAS, PI3K-inhibitors) appear able to partially impact on transferrin/CD71-promoted growth, but further investigation of this important mitogenic mechanism may assist in designing new therapeutic strategies to target highly proliferative, endocrine resistant breast cancers. CD71 appears to be a candidate marker of a subgroup of ER+/luminal-like breast cancer characterised by poor outcome and resistance to tamoxifen.
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PMID:Transferrin receptor (CD71) is a marker of poor prognosis in breast cancer and can predict response to tamoxifen. 1923 37

The proteomic profiles from two distinct ovarian endometrioid tumor-derived cell lines, (MDAH-2774 and TOV-112D) each with different morphological characteristics and genetic mutations, have been studied. Characterization of the differential global protein expression between these two cell lines has important implications for the understanding of the pathogenesis of ovarian endometrioid carcinoma. In this comparative proteomic study, extensive fractionation of peptides generated from whole-cell trypsin digestion was achieved by coupling cIEF in the first-dimensional separation with capillary LC (RP-HPLC) in the second dimensional separation. Online analysis was performed using tandem mass spectra acquired by a linear ion trap mass spectrometer from triplicate runs. A total of 1749 and 1955 proteins with protein probability above 0.95 were identified from MDAH-2774 and TOV-112D after filtering through Peptide Prophet/Protein Prophet software. Differentially expressed proteins were further investigated by ingenuity pathway analysis (IPA) to reveal the association with important biological functions. Canonical pathway analysis using IPA demonstrates that important signaling pathways are highly associated with one of these two cell lines versus the other, such as the PI3K/AKT pathway, which is found to be significantly predominant in MDAH-2774 but not in TOV-112D. Also, protein network analysis using IPA highlights p53 as a central hub relating to other proteins from the connectivity map. These results illustrate the utility of high throughput proteomics methods using large-scale proteome profiling combined with bioinformatics tools to identify differential signaling pathways, thus contributing to the understanding of mechanisms of deregulation in neoplastic cells.
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PMID:Comparative proteomic study of two closely related ovarian endometrioid adenocarcinoma cell lines using cIEF fractionation and pathway analysis. 1928 85


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