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)

Rats treated with the alkylating agent methylnitrosourea (MNU) develop multiple, hormonally dependent mammary tumors. Roughly 50% of the tumors have Ha-ras mutation, whereas 50% do not. The MNU-induced rat mammary tumor model was employed to examine the therapeutic efficacy of the farnesyltransferase inhibitor (FTI), R115777, and to examine the use of genomics in identifying susceptible tumors as well as identifying genes whose expression are modulated by FTI treatment. In animals bearing palpable mammary tumors (< 7 mm diameter), we performed a surgical biopsy, and 3 days following the biopsy, rats were treated with R115777 (50 mg/kg body wt/day) by gavage. Tumors with Ha-ras mutations underwent profound regression, with nearly 90% showing complete regressions within 4 weeks. In contrast, the non-Ha-ras mutation-bearing tumors yielded a more variable response, although roughly half of the non-Ha-ras mutation tumors underwent significant regression. These results show that although all tumors appear to respond to the FTI inhibitor the tumors with Ha-ras mutations were exquisitely sensitive. We employed a microarray approach to define potential targets and the mechanism of action of R115777 in Ha-ras mutant or wildtype tumors following treatment with FTI. In addition, we determined whether gene expression prior to FTI treatment can be used to differentiate highly sensitive tumors (Ha-ras mutant) and tumors with variable sensitivity (Ha-ras wildtype). Untreated or FTI-treated (4 days at 50 mg/kg body wt) tumors (Ha-ras mutant or wildtype) were examined using oligonucleotide arrays. A significant number of genes were differentially expressed in control rat mammary tumors with or without an activated Ha-ras mutation, suggesting that a microarray analysis might differentiate highly sensitive and variably sensitive tumors. Most of the genes whose expressions were modulated by FTI in tumors were independent of Ha-ras status and were presumably modulated by effects on farnesylation of proteins other than Ha-ras. However, treatment of Ha-ras-mutated mammary tumors with R155777 results in preferential modulation of genes involved in ras-MAP kinase signal transduction pathway and in decreased expression of many genes involved with cell proliferation. In contrast, several classes of genes are altered in rat mammary tumors without a mutated Ha-ras, suggesting that non-ras targets are involved. Ras pathway related genes, p53, WT1 and PCNA, were preferentially modulated in Ha-ras-mutated tumors, whereas modulation of genes in the G-protein pathway, various cytochrome p450s and RB1 are involved in Ha-ras wildtype tumors. Elucidation of gene expression changes in FTI-treated or control rat mammary adenocarcinomas will help in identifying potential pharmacodynamic markers of FTI treatment as well as potential molecular targets of R115777 and other FTIs.
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PMID:Efficacy of the farnesyltransferase inhibitor R115777 in a rat mammary tumor model: role of Ha-ras mutations and use of microarray analysis in identifying potential targets. 1640 72

Recent data showed that epidermal growth factor receptor (EGFR) inhibitors, such as ZD1839, alone or in combination with chemotherapeutic agents for androgen-independent prostate cancer (AIPC) did not produce promising results in clinical settings. More effective regimens involving novel stronger inhibitor of EGFR and better combinations are needed. The anti-tumor activity of PD168393, an irreversible EGFR inhibitor, with or without chemotherapeutic agents for the treatment of AIPC was investigated in vitro. In results, both the androgen-independent cell lines PC-3 and DU145 expressed higher levels of EGFR than the androgen-dependent MDA PCa 2b and androgen-responsive LNCaP cells by Western blotting. DU145 was much more sensitive to PD168393 and ZD1839 than MDA PCa 2b. PD168393, but not ZD1839, significantly potentiated paclitaxel cytotoxicity against DU145 by MTT assay and median-effect analysis. The combination of PD168393 or ZD1839 with other cytotoxic agents including docetaxel and 5-fluorouracil, however, was either additive or antagonistic. Compared to paclitaxel alone, PD168393 significantly enhanced paclitaxel-induced DNA fragmentation, sub-G1 fraction accumulation, mitochondrial membrane dysfunction, cytochrome C release, caspase-3 activation and eventually apoptosis. These molecular events were accompanied by Bad up-regulation, p53 and p21Waf1/Cip1 induction, ERK1/2 inactivation and inhibition of EGFR phosphorylation in the presence of PD168393. These effects did not involve significant alteration in the Akt1/2 and STAT3 signaling pathway. In conclusion, the combination of paclitaxel and PD168393 produced a profound synergistic growth inhibition of AIPC cells. Combining PD168393 with paclitaxel may have clinical benefits and warrants further investigation.
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PMID:Epidermal growth factor receptor inhibitor (PD168393) potentiates cytotoxic effects of paclitaxel against androgen-independent prostate cancer cells. 1641 5

The major event in human immunodeficiency virus type 1 (HIV-1) infection is the death of many cells related to host immune response. The demise of these cells is normally explained by cell suicide mechanism, apoptosis. Interestingly, the decrease in the number of immune cells, such as non-CD4(+) cells as well as CD4(+) T cells, in HIV infection usually occurs in uninfected bystander cells, not in directly infected cells. It has, therefore, been suggested that several soluble factors, including viral protein R (Vpr), are released from the infected cells and induce the death of bystander cells. Some studies show that Vpr interacts directly with adenine nucleotide translocator (ANT) to induce mitochondrial membrane permeabilization (MMP). The MMP results in release of some apoptogenic factors such as cytochrome-c (cyt-c) and apoptosis-inducing factor (AIF). Vpr also has indirect effect on mitochondria through enhancing the level of caspase-9 transcription and suppressing nuclear factor-kappa B (NF-kB). The involvement of p53 in Vpr-induced apoptosis remains to be studied. On the other hand, low level of Vpr expression has anti-apoptotic effect, whereas it's high level of expression induces apoptosis. Extracellular Vpr also exhibits cytotoxicity to uninfected bystander cells through apoptotic or necrotic mechanism. The facts that Vpr has cytotoxic effect on both infected cells and bystander cells, and that it exhibits both pro- and anti-apoptotic activity may explain its role in viral survival and disease progression.
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PMID:Role of HIV Vpr as a regulator of apoptosis and an effector on bystander cells. 1651 42

Repeated frying of food produces numerous carcinogens including polycyclic aromatic hydrocarbons (PAHs). Our prior studies have shown that repeated fish fried oil extract (RFFE) induces cytochrome P (CYP)-450 1A1/2 isozymes thereby causing increased generation of electrophilic reactive metabolites of PAHs and subsequent binding to DNA. In the present study, molecular events associated with DNA damage, apoptosis, and proliferation following topical exposure to RFFE have been investigated in mice. Single topical application of RFFE (500 microg) for 24-48 h caused significant DNA damage with Comet assay in terms of olive tail moment (OTM) (204-246%), tail DNA (253-293%), and tail length (172-195%). Overexpression of p53 and p21WAF1 proteins was observed in skin cells following single topical exposure of RFFE for 24-72 h, which was similar to that of benzo(a)pyrene (BP) exposure (24 h). Though RFFE and BP exposure separately, did not result in G(0)/G(1) arrest, but a significant increase in the proportion of cells in S-phase was observed. Apoptotic induction was noticed in skin cells, with maximum induction after 48 h of exposure to RFFE. Further, topical treatment of mice with RFFE (500 microg) for 6 h significantly increased orinithine decarboxylase (ODC) activity by 7.5-fold when compared to control. These results indicate that RFFE exposure caused ODC induction accompanied by increased levels of p53 and p21WAF1 proteins leading of apoptosis and delay of cells in S-phase thereby indicating the possible carcinogenic potential of RFFE.
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PMID:Induction of P53, P21Waf1, orinithine decorboxylase activity, and DNA damage leading to cell-cycle arrest and apoptosis following topical application of repeated fish fried oil extract to mice. 1686 78

Aurora-A is frequently altered in epithelial malignancies. Overexpressing Aurora-A induces centrosome amplification and G2/M cell cycle progression. We have previously shown elevated level of Aurora-A in ovarian cancer and activation of telomerase by Aurora-A in human mammary and ovarian epithelia. Here we report that Aurora-A protects ovarian cancer cells from apoptosis induced by chemotherapeutic agent and activates Akt pathway in a p53-dependent manner. Ectopic expression of Aurora-A renders cells resistant to cisplatin (CDDP), etoposide and paclitaxel-induced apoptosis and stimulates Akt1 and Akt2 activity in wild-type p53 but not p53-null ovarian cancer cells. Aurora-A inhibits cytochrome C release and Bax conformational change induced by CDDP. Knockdown of Aurora-A by RNAi sensitizes cells to CDDP-induced apoptosis and decreases phospho-Akt level in wild-type p53 cells. Reintroduction of p53 decreases Akt1 and Akt2 activation and restores CDDP sensitivity in p53-null but not p53-null-Aurora-A cells. Inhibition of Akt by small molecule inhibitor, API-2, overcomes the effects of Aurora-A-on cell survival and Bax mitochondrial translocation. Taken collectively, these data indicate that Aurora-A activates Akt and induces chemoresistance in a p53-dependent manner and that inhibition of Akt may be an effective means of overcoming Aurora-A-associated chemoresistance in ovarian cancer cells expressing wild-type p53.
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PMID:Aurora-A induces cell survival and chemoresistance by activation of Akt through a p53-dependent manner in ovarian cancer cells. 3081 57

Curcumin (diferuloylmethane), the yellow pigment in turmeric (Curcuma longa), is known to inhibit proliferation of cancer cells by arresting them at various phases of the cell cycle and to induce apoptosis in tumor cells. Curcumin-induced apoptosis mainly involves the activation of caspase-3 and mitochondria-mediated pathway in various cancer cells of different tissue origin. In the present study, the induction of apoptosis and cytotoxicity by curcumin in colon cancer colo 205 cells was investigated by using flow cytometry. The results demonstrated that curcumin induced cytotoxicity and apoptosis dose- and time-depedently. Curcumin induced the production of reactive oxygen species (ROS) and Ca+2, decreased the levels of mitochondria membrane potential and induced caspase-3 activity. Curcumin also promoted the expression of Bax, cytochrome C, p53 and p21 but inhibited the expression of Bcl-2. These observations suggest that curcumin may have a possible therapeutic potential in colon cancer patients.
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PMID:Curcumin-induced apoptosis of human colon cancer colo 205 cells through the production of ROS, Ca2+ and the activation of caspase-3. 1720 Nov 58

Meclizine (MEC), a histamine H1 antagonist, is used for the treatment of motion sickness and vertigo. In this study, we demonstrate that MEC dose-dependently induced apoptosis in human colon cancer cell lines (COLO 205 and HT 29 cells). Results of a DNA ladder assay revealed that DNA ladders appeared with MEC treatment in COLO 205 cells at dosage of >50 microM. In addition, the total cell number decreased dose-dependently after treatment with MEC in COLO 205 and HT 29 cells. Using flow cytometry, the percentage of COLO 205 cells arrested at G0/G1 phase increased dose-dependently. Analysis of changes in cell-cycle arrest-associated proteins with Western blotting showed that p53 and p21 were upregulated after treatment with MEC. The kinase activities of cyclin-dependent kinase 2 (CDK2) and CDK4 were suppressed in MEC-treated cells. As for apoptosis, MEC may induce upregulation of p53 and downregulation of Bcl-2, thus causing the release of cytochrome C from mitochondria and the translocation of apoptosis-inducing factor (AIF) to the nucleus. This resulted in the activation of caspase 3, 8, and 9. Our results provide the molecular basis of MEC-induced apoptosis and cell-cycle arrest in human colon cancer cells.
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PMID:Induction of apoptosis and cell-cycle arrest in human colon cancer cells by meclizine. 1722 94

The cytotoxic effects of a new compound, ethyl 2-[N-p-chlorobenzyl-(2'-methyl)] aniline-4-oxo-4,5-dihydrofuran-3-carboxylate (JOT01007) have been tested in mouse leukemia WEHI-3 cells. In this study, the mechanisms by which JOT01007 acts on a human cervical cancer cell line (Ca Ski) to bring about an increase in the ratio of Bax/Bcl-2, reduction of the mitochondrial membrane potential (MMP), increase in the levels of cytoplasmic Ca2+, activation of caspases and fragmentation of DNA, and apoptosis were investigated. Flow cytometric analysis demonstrated that JOT01007 induced a decrease of MMP in Ca Ski cells. JOT01007 induced an increase in the level of cytoplasmic Ca2+, which was inhibited by BAPTA (calcium chelator), and BAPTA accelerated the MMP reduction, and significantly blocked JOT01007-induced apoptosis. Western blotting demonstrated that JOT01007 induced an increase in the levels of p53, p2I, cytochrome-c, caspase-3 and Bax, but decreased the level of Bcl-2. In conclusion, our data demonstrate that JOT01007-induced apoptosis occurs via a mitochondria-dependent pathway closely related to the level of cytoplasmic Ca2+ in Ca Ski cells.
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PMID:Ethyl 2- [N-p-chlorobenzyl- (2'-methyl)] anilino-4-oxo-4,5-dihydrofuran-3-carboxylate (JOT01007)induces apoptosis in human cervical cancer Ca Ski cells. 1743 94

Both the resistance of tumor cells to cisplatin and dose-related toxicity remain two of the most important problems in the chemotherapy of clinical oral squamous cell carcinoma (OSCC). Researchers have been seeking a combinative treatment regimen to improve the effect of chemotherapy. As potent new anti-cancer drugs, histone deacetylase inhibitors (HDACI(S)) have been reported to be associated with chromatin modification and display synergistic activities with some traditional chemotherapeutic agents. In this study, we evaluated the potential combinative effect of low dose cisplatin and suberoylanilide hydroxamic acid (SAHA, one of the most potent HDACI(S)) in OSCC cell lines. Cell viability and apoptotic assay were examined. Compared with either cisplatin (4 microg/ml) or SAHA (2 microM) treated alone, co-administration of both drugs synergistically induces cytotoxicity and apoptosis in both Tca8113 and KB cell lines. Furthermore, diverse apoptosis-associated proteins, including p53, BID, cytochrome C and caspase-3 were involved in the induction of apoptosis. Our results suggest that concurrent treatment with SAHA enhances tumor cell sensitivity to subtoxic doses of cisplatin. This may be regarded as a novel strategy for treatment of OSCC.
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PMID:Enhancement of cisplatin induced apoptosis by suberoylanilide hydroxamic acid in human oral squamous cell carcinoma cell lines. 1744 79

Smoking induces mutations via the formation of DNA-adducts in the bronchial and alveolar epithelium and contributes to the development of lung cancer. Benz(a)pyrene and nitrosamine, typical carcinogens in cigarette smoke, undergo metabolic activation by the phase I enzymes, such as cytochrome P450 (CYP) 1A1, CYP2A6 and CYP2E1. The transcriptional regulation of these phase I enzymes is regulated by arylhydrocarbon receptor (AH-R) which binds many well-known carcinogens. To identify a cause and effect relationship, the expression of cytochrome CYP and AH-R in the bronchial epithelium was correlated with the history of cigarette smoking in patients with non-small cell lung carcinoma (NSCLC). Although CYP3A+ cells were absent in the bronchial epithelium of all patients, there were many CYP2E1+ cells in heavy (>1000 cigarette/day x year) smokers (38.5%). In contra-distinction, there was significantly less number of CYP2E1+ cells in light (less than 1000 cigarette/day x year) smokers (15.6%) or non-smokers (10.0%). Similarly, there were more CYP1A1+ (19.2%) and CYP2A6+ cells in heavy (65.4%) smokers as compared to non-smokers. The number of AH-R+ cells was also significantly higher in cases with p53 mutation (62.5%) than those without (12.2%) mutation. Since in patients with early NSCLC, CYP positivity showed a close correlation with a poor survival (p less than 0.01), expression of CYP in bronchial epithelium has a prognostic potential.
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PMID:Increased cytochrome P450 and aryl hydrocarbon receptor in bronchial epithelium of heavy smokers with non-small cell lung carcinoma carries a poor prognosis. 1748 91


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