ABSTRACT
Ovarian cancer is the leading cause of death in women worldwide. Cisplatin is the core of first-line chemotherapy for patients with advanced ovarian cancer. Many patients eventually become resistant to cisplatin, diminishing its therapeutic effect. MicroRNAs (miRNAs) have critical functions in diverse biological processes. Using miRNA profiling and polymerase chain reaction validation, we identified a panel of differentially expressed miRNAs and their potential targets in cisplatin-resistant SKOV3/DDP ovarian cancer cells relative to cisplatin-sensitive SKOV3 parental cells. More specifically, our results revealed significant changes in the expression of 13 of 663 miRNAs analyzed, including 11 that were up-regulated and 2 that were down-regulated in SKOV3/DDP cells with or without cisplatin treatment compared with SKOV3 cells with or without cisplatin treatment. miRNA array and mRNA array data were further analyzed using Ingenuity Pathway Analysis software. Bioinformatics analysis suggests that the genes ANKRD17, SMC1A, SUMO1, GTF2H1, and TP73, which are involved in DNA damage signaling pathways, are potential targets of miRNAs in promoting cisplatin resistance. This study highlights candidate miRNA-mRNA interactions that may contribute to cisplatin resistance in ovarian cancer.
Subject(s)
Female , Humans , Cell Cycle Proteins , Cell Line, Tumor , Chromosomal Proteins, Non-Histone , Cisplatin , Cysteine Endopeptidases , DNA-Binding Proteins , Down-Regulation , Drug Resistance, Neoplasm , Endopeptidases , MicroRNAs , Nuclear Proteins , Ovarian Neoplasms , Phosphoproteins , RNA, Messenger , Signal Transduction , Transcription Factors, TFII , Tumor Protein p73 , Tumor Suppressor Proteins , Up-RegulationABSTRACT
<p><b>OBJECTIVE</b>To explore a new approach in gene therapy of ovarian cancer, we used RNAi to inhibit survivin gene expression, and explore the effect of survivin and neu RNAi on growth, apoptosis and chemosensitivity of ovarian cancer cell line SKOV3/DDP cells.</p><p><b>METHODS</b>Expression vector of survivin gene-targeting siRNA was constructed using pSilencer 1.0-U6 vector containing U6 promotor (pSilencer-survivin) and transfected into SKOV3/DDP cells by lipofectamine. The untransfected group and pSilencer-control group were used as control. The expressions of survivin mRNA and protein were identified by RT-PCR and Western blot assay. The proliferation of SKOV3/DDP cells was determined by MTT assay. The apoptosis rate and cell cycle distribution were analyzed by flow cytometry. Cisplatin (DDP) resistance experiment was performed in SKOV3/DDP cells with RNAi.</p><p><b>RESULTS</b>Survivin RNAi plasmid knocked-down survivin expression in SKOV3/DDP cells obviously, arrested the cells at G(1)/G(0) phase, inhibited the cell proliferation and promoted cell apoptosis. The IC(50) of DDP to SKOV3/DDP cells transfected with survivin siRNA was dropped.</p><p><b>CONCLUSION</b>Survivin RNAi can partly suppress the expression of survivin in SKOV3/DDP cells, inhibit the cell proliferation and promote cell apoptosis. Survivin RNAi can enhance the cell sensitivity to apoptosis induced by cisplatin, which implies that survivin RNAi may partly reverse the drug resistance of ovarian cancer. RNAi could be a new approach for gene therapy of cancer.</p>
Subject(s)
Female , Humans , Antineoplastic Agents , Pharmacology , Apoptosis , Cell Cycle , Cell Line, Tumor , Cell Proliferation , Cisplatin , Pharmacology , Drug Resistance, Neoplasm , Inhibitor of Apoptosis Proteins , Inhibitory Concentration 50 , Microtubule-Associated Proteins , Genetics , Metabolism , Ovarian Neoplasms , Metabolism , Pathology , RNA Interference , RNA, Messenger , Metabolism , RNA, Small Interfering , Genetics , TransfectionABSTRACT
Human papillomavirus (HPV) is a common small DNA tumor virus that specifically infects squamous epithelial cells and causes benign or malignant epithelial lesions such as genital warts and cervical cancer. High-risk HPV is detected in specimens of more than 90% of cervical cancer. In the 7. 9 kb genome of HPV, E6 and E7 are the crucial viral oncoproteins that consistently maintained after viral integration into host cell genome. These two proteins interfere with cell proliferation and differentiation through interacting with important tumor suppressors including p53 and pRb. High-risk HPV E6/E7 also induces genomic instability, facilitating cell transformation.
Subject(s)
Female , Humans , Cell Differentiation , Cell Proliferation , Cell Transformation, Neoplastic , Metabolism , Pathology , Genomic Instability , Host-Pathogen Interactions , Oncogene Proteins, Viral , Genetics , Physiology , Papillomaviridae , Genetics , Physiology , Papillomavirus Infections , Metabolism , Pathology , Uterine Cervical Neoplasms , Metabolism , Pathology , VirologyABSTRACT
<p><b>OBJECTIVE</b>To detect the expression of survivin in esophageal cancer and elucidate its function in esophageal cancer.</p><p><b>METHODS</b>Expression of surviv in was detected in paired normal and tumor tissues from patients with esophageal cancer by semi-quantitative RT-PCR. A dominant-negative survivin (surT34A) was transfected into esophageal cancer EC9706 cells (EC9706surT34A). Colony formation and apoptosis of the parental and surT34A-transfected EC9706 cells were examined in soft agar and by flow cytometry, respectively.</p><p><b>RESULTS</b>Survivin mRNA expression of tumor tissues was higher than normal tissues in 18/27 (66.7%) samples. The expression level of survivin mRNA in tumor tissues (2.08 +/- 1.32) was significantly higher than that in normal tissues (1.22 +/- 1.09). EC9706 surT34A cells formed fewer colonies on agar than the non-transfected ones. After serum withdrawal, EC9706surT34A had higher apoptotic ratio than control, but survivin could reduce the apoptotic ratio.</p><p><b>CONCLUSION</b>Overexpression of survivin is a common eventin esophageal cancer. The dominant-negative survivin can partially inhibit the malignant phenotype of esophageal cancer.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Apoptosis , Carcinoma, Squamous Cell , Metabolism , Pathology , Cell Line, Tumor , Esophageal Neoplasms , Metabolism , Pathology , Gene Expression Regulation, Neoplastic , Inhibitor of Apoptosis Proteins , Microtubule-Associated Proteins , Genetics , Physiology , Mutation , Neoplasm Proteins , Genetics , Physiology , RNA, Messenger , Genetics , TransfectionABSTRACT
<p><b>OBJECTIVE</b>To study the inhibitory effect of RNA interference (RNAi) on c-myc expression in hepatocellular carcinoma cell line, HepG2.</p><p><b>METHODS</b>Expression vector of c-myc gene-targeting small interference RNA (siRNA) was constructed (psilencer-c-myc) and transfected into HepG2 cells by lipofectamine, and the unloaded vector was used as control (mock). The expression of c-myc mRNA and protein was identified by quantitive PCR and Western blot. Apoptosis of the transfected cells was examined by flow cytometry and immunofluorescent microscopy.</p><p><b>RESULTS</b>After HepG2 cells were transfected with psilencer-c-myc, the expression of c-myc mRNA and protein was suppressed with an inhibition rate of 67% compared with the mock-transfected cells. Apoptosis was identified in the transfected HepG2 cells.</p><p><b>CONCLUSION</b>The expression of c-myc at transcriptional and translational levels in HepG2 cells transfected with siRNA is markedly inhibited, which may be associated with the induction of apoptosis.</p>