u-0126 and Uterine-Cervical-Neoplasms

The p53:miR-34a:E2F positive feed-forward loop and the p53:miR-605:Mdm2 positive feed-back loop have been identified to be crucial oncogenesis/tumor suppressor-regulating signaling pathways. In this study, we sought to examine the hypothesis that neoadjuvant chemotherapy (NAC) is a better approach with improved prognosis and outcomes after laparoscopical radical hysterectomy (LRH) on patients with cervical cancer and to elucidate the potential roles of the p53:miR-34a:E2F1 and the p53:miR-605:Mdm2 signaling pathways in this therapy.. Twenty-one patients with stage IIB cervical cancer were recruited to this study and they were randomly divided into two groups: LRH (n=10) and NAC+LRH (n=11) groups. The NAC+LRH group consisted of 4 cycles of cisplatin, paclitaxel and carboplatin. Complication rates and NAC outcomes (tumor size changes, 2-year disease-free survival rate, and 2-year overall survival rate) were compared between the two groups. Expression of p53, Mdm2, E2F1, miR-34a, and miR-605 at mRNA and protein levels from the tumor tissues was analyzed.. We observed that the diameter of tumors following chemotherapy was substantially smaller in the NAC+LRH patients than in LRH patients. No recurrence or metastasis after surgery was observed in the NAC+LRH patients, whereas 2 out of 10 LRH patients had recurrences and 1 had metastasis. The 2-year disease-free and overall survival rates were apparently higher in the NAC+LRH group than in the LRH group. Furthermore, molecular biology analyses revealed that the protein and mRNA levels of p53 were both markedly increased in patients who received NAC than those who did not, and oppositely, the levels of E2F1 and Mdm2 were significantly lower in the NAC+LRH patients than in the LRH patients. The levels of miR-34a and miR-605 were considerably higher with NAC relative to without NAC. Among the three anti-cancer drugs included in NAC, cisplatin was found to be the main component that caused increases in p53 protein levels, miR-34a and miR-605 miRNA levels, and decreases in Mdm2 and E2F1 protein levels. Furthermore, ERK1/2 inhibitor U0126 or TAB1 siRNA mitigated these changes induced by cisplatin.. These findings not only indicate NAC as a rational approach for better treatment of cervical cancer with improved therapeutic outcomes, due partly to the ability of cisplatin to promote the p53:miR-34a:E2F1 positive feed-forward loop and the p53:miR-605:Mdm2 positive feedback loop.

Topics: Adaptor Proteins, Signal Transducing; Adult; Antineoplastic Combined Chemotherapy Protocols; Butadienes; Cisplatin; Disease-Free Survival; E2F1 Transcription Factor; Female; Gene Expression Regulation, Neoplastic; Genes, p53; Humans; Hysterectomy; MicroRNAs; Middle Aged; Neoadjuvant Therapy; Nitriles; Prognosis; Proto-Oncogene Proteins c-mdm2; Uterine Cervical Neoplasms

Topics: Butadienes; Case-Control Studies; Enzyme Inhibitors; Female; Human papillomavirus 16; Humans; Mitogen-Activated Protein Kinase 12; Neoplasm Proteins; Nitriles; Papillomavirus Infections; RNA Interference; Signal Transduction; Uterine Cervical Neoplasms

In this study, we examined whether the peroxisome proliferator-activated receptor γ (PPARγ) agonists, ciglitazone (CGZ) and troglitazone (TGZ), induce cell death in human cervical cancer HeLa cells. The cells were treated with a range of CGZ or TGZ doses for 24 or 48 h. Low concentrations of CGZ (≤10 μM) or TGZ (≤20 μM) had no effect on cell viability whereas higher doses induced cell death in a time- and dose-dependent manner as evidenced by the detection of activated caspase-3 and PARP cleavage. Treatment with the PPARγ antagonist GW9662 followed by PPARγ agonists did not increase CGZ- or TGZ-induced cell death, indicating that PPARγ agonists induced HeLa cell death independently of PPARγ. Moreover, ERK1/2 activation was observed at a CGZ concentration of 25 μM and a TGZ concentration of 35 μM, both of which induced cell death. To elucidate the role of ERK1/2 activated by the two PPARγ agonists, the effect of U0126, an inhibitor of ERK1/2, on PPARγ-agonist-induced cell death was examined. Treatment with 10 or 20 μM U0126 followed by CGZ or TGZ induced the down-regulation of ERK1/2 activity and a decrease in Bcl-2 expression accompanied by the collapse of mitochondrial membrane potential, which in turn significantly enhanced CGZ- or TGZ-induced apoptotic cell death. Our results suggest that PPARγ agonists are capable of inducing apoptotic cell death in HeLa cells independently of PPARγ and that inhibition of ERK1/2 activity offers a strategy to enhance the cytotoxicity of PPARγ agonists in the treatment of cervical cancer.

Topics: Antineoplastic Agents; Apoptosis; Butadienes; Caspase 3; Cell Survival; Cervix Uteri; Chromans; Drug Synergism; Enzyme Inhibitors; Female; HeLa Cells; Humans; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Nitriles; PPAR gamma; Thiazolidinediones; Troglitazone; Uterine Cervical Neoplasms

Small-molecule inhibitors targeted MAPK have been wildly used for some cancer therapeutics as a biologically viable model, but no one has been used for cervical caner. ERK1/2, one of MAPK kinases, is expressed high in cervical cancer tissue. The aim of the present study was to evaluate the effects of ERK1/2 inhibitor U0126 on proliferation and apoptosis of cervical cancer cells and appraise the correlated mechanism of the effects. In this study, the cell proliferation of Hela and C33A cervical cancer cells was tested by Cell Counting Kit-8 (CCK8) assay and cell counting after treated with ERK1/2 inhibitor U0126. The cell cycle and apoptosis were evaluated by flow cytometry (FCM). The protein levels of ERK1/2 and c-Fos and c-Jun were detected by Western blot. The results indicated that after down-regulating ERK1/2 proteins with the inhibitor U0126, Hela and C33A cells proliferation was inhibited, cell apoptosis was promoted, the proportions of G0/G1 stage in cell cycle increased, and G2/M stages decreased. After down-regulating ERK1/2 proteins of Hela and C33A cells, the expression levels of p-c-Fos protein decreased, while p-c-Jun protein increased. The results of this study indicated that ERK1/2 may promote the development of cervical cancer cells, suggesting ERK1/2 inhibitor may be used as an effective target for cervical cancer therapies working for. It might inhibit cervical cancer cells growth via regulating the transcription factors expression of c-Fos and c-Jun.

Topics: Apoptosis; Butadienes; Cell Cycle; Cell Proliferation; Enzyme Inhibitors; Female; HeLa Cells; Humans; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Nitriles; Proto-Oncogene Proteins c-fos; Proto-Oncogene Proteins c-jun; Uterine Cervical Neoplasms

Naturally-occurring chemopreventive agent phenethyl isothiocyanate (PEITC), derived primarily from watercress, has been shown to inhibit cell growth and induce apoptosis in cancer cells. In this study, we examined the potential of PEITC in enhancing cisplatin-induced apoptosis in cervical cancer cells and its mechanisms.. HeLa cells were exposed to PEITC, cisplatin or both. Pretreatment of cells with PEITC strongly enhanced cisplatin-induced cytotoxicity. PEITC activated the mitogen-activated protein kinases, including c-Jun N-terminal kinase (JNK), extracellular signal-related kinase (ERK), and p38. Caspase-3 activity assay demonstrated that the synergistic induction of apoptosis was significantly attenuated by MEK1/2 inhibitor U0126, but not by JNK or p38 inhibitor, suggesting that ERK activation is responsible for the synergistic effect. We found that NF-κB signaling pathway is not involved in the synergistic effect. Sulforaphane and benzyl isothiocyanate, two other members of the isothiocyanate family, also sensitize HeLa cells to apoptosis induced by cisplatin. Furthermore, we found that the synergistic effect was also observed in cervical cancer C33A and breast cancer MCF-7 cells but not in normal mammary epithelial MCF-10A cells. Finally, we demonstrated that Noxa induction was associated with apoptosis induced by PEITC plus cisplatin.. Taken together, this study shows that PEITC can sensitize cancer cells to apoptosis induced by cisplatin and this effect is mediated through ERK activation, suggesting the potential of PEITC to be used as an adjuvant with cisplatin in combination therapeutic treatments.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Breast Neoplasms; Butadienes; Caspase 3; Cell Line, Tumor; Cisplatin; Drug Synergism; Female; HeLa Cells; Humans; Isothiocyanates; JNK Mitogen-Activated Protein Kinases; MAP Kinase Kinase 1; NF-kappa B; Nitriles; p38 Mitogen-Activated Protein Kinases; Proto-Oncogene Proteins c-bcl-2; Uterine Cervical Neoplasms