title: Downregulation of miR-33a-5p in Hepatocellular Carcinoma: A Possible Mechanism for Chemotherapy Resistance.
abstract: BACKGROUND Multi-drug resistance is one of the major problems limiting the efficacy of cisplatin (CDDP) in treatment of hepatocellular carcinoma (HCC), and abnormal microRNA (miRNA) expression in drug-resistant cell lines plays an important role in liver cancer chemotherapy resistance. MATERIAL AND METHODS We established stable Hep3B and 97L HCC cell strains resistant to CDDP, both in vitro and in vivo. A combination of microRNA microarray and RT-qPCR experiments were used to screen differentially expressed miRNAs in HCC cell strains. A CCK-8 assay was carried out to detect and calculate the survival rates and relative inhibitory rates. Oligonucleotide transfection was used to confirm the regulatory function of the miRNA in HCC drug resistance. RESULTS The IC50 of Hep3B/CDDP(v), 97L/CDDP(v), Hep3B/CDDP(s), and 97L/CDDP(s) were significantly higher than that of their parental cells. Moreover, the doubling time of drug-resistant cells increased compared with their parent cells. MiRCURYTM LNA Array (v 16.0) high-throughput tests of resistant cell models and their parent cells showed that there were 5 downregulated microRNAs in the 4 drug-resistant cell lines, and we chose hsa-miR-33a-5p as our target for further study. Oligonucleotide transfection showed that miR-33a-5p overexpression increased the cisplatin sensitivity of Hep3B/CDDP(v) and 97L/CDDP(v) drug-resistant cells and reduced their resistance. Additionally, inhibition of miR-33a-5p expression reduced cisplatin sensitivity in Hep3B and 97L and increased their drug resistance. CONCLUSIONS This study confirmed that the most downregulated microRNA, miR-33a-5p, can mediate the cisplatin resistance of HCC cells, providing a new and feasible direction for research into combatting liver cancer chemotherapy resistance.
authors.affiliation: Department of Hepatic Surgery and Liver Transplantation Center of The Third Affiliated Hospital, Organ Transplantation Institute, Sun Yat-sen University; Organ Transplantation Research Center of Guangdong Province, Guangzhou, Guangdong, China (mainland).
authors.forename: Wei
authors.initials: W
authors.lastname: Meng
authors.affiliation: Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China (mainland).
authors.forename: Yan
authors.initials: Y
authors.lastname: Tai
authors.affiliation: Department of Hepatic Surgery and Liver transplantation Center of The Third Affiliated Hospital, Organ Transplantation Institute, Sun Yat-sen University; Organ Transplantation Research Center of Guangdong Province, Guangzhou, Guangdong, China (mainland).
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Hepatic Surgery and Liver transplantation Center of The Third Affiliated Hospital, Organ Transplantation Institute, Sun Yat-sen University; Organ Transplantation Research Center of Guangdong Province, Guangzhou, Guangdong, China (mainland).
authors.forename: Binsheng
authors.initials: B
authors.lastname: Fu
authors.affiliation: Department of Hepatic Surgery and Liver transplantation Center of The Third Affiliated Hospital, Organ Transplantation Institute, Sun Yat-sen University; Organ Transplantation Research Center of Guangdong Province, Guangzhou, Guangdong, China (mainland).
authors.forename: Tong
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China (mainland).
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Hepatic Surgery and Liver transplantation Center of The Third Affiliated Hospital, Organ Transplantation Institute, Sun Yat-sen University; Organ Transplantation Research Center of Guangdong Province, Guangzhou, Guangdong, China (mainland).
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Hepatic Surgery and Liver transplantation Center of The Third Affiliated Hospital, Organ Transplantation Institute, Sun Yat-sen University; Organ Transplantation Research Center of Guangdong Province, Guangzhou, Guangdong, China (mainland).|Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China (mainland).|Cell-Gene Therapy Translational Medicine Research Center, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China (mainland).
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China (mainland).|Cell-Gene Therapy Translational Medicine Research Center, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China (mainland).
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Jackson Laboratory-Genomic Medicine, Farmington, CT, USA.
authors.forename: Yuliang
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Department of Hepatic Surgery and Liver transplantation Center of The Third Affiliated Hospital, Organ Transplantation Institute, Sun Yat-sen University; Organ Transplantation Research Center of Guangdong Province, Guangzhou, Guangdong, China (mainland).|Guangdong Key Laboratory of Liver Disease Research, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China (mainland).|Cell-Gene Therapy Translational Medicine Research Center, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China (mainland).
authors.forename: Guihua
authors.initials: G
authors.lastname: Chen
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; C550416:MIRN33a microRNA, human; D035683:MicroRNAs; D002945:Cisplatin