title: siRNA-mediated Bcl-2 and Bcl-xl gene silencing sensitizes human hepatoblastoma cells to chemotherapeutic drugs.
abstract: 1. The aim of the present study was to investigate the changes in chemotherapeutic drug sensitivity of HepG2 cells transfected with Bcl-2 and Bcl-xl siRNA expression vectors. 2. Bcl-2 and Bcl-xl siRNA and negative siRNA expression vectors were constructed and stably transfected into HepG2 cells. Reverse transcriptase-polymerase chain reaction was used to detect the target gene expression, and the Bcl-2, Bcl-xl, Bax and caspase-3 protein levels were measured using western blots and immunofluorescence. The sensitivity of the cells to the chemotherapeutic drugs 5-fluorouracil (5-FU) and 10-hydroxycamptothecin (HCPT) was analysed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazoliumbromide (MTT) and flow cytometry. 3. The Bcl-2 and Bcl-xl gene expression and corresponding protein levels in Bcl-2 siRNA, Bcl-xl siRNA and Bcl-2/Bcl-xl siRNA transfected cells were reduced compared with negative siRNA transfected or untreated cells. The Bax protein level remained unaltered but the caspase-3 level was enhanced when Bcl-2 and Bcl-xl protein levels were reduced. The MTT results demonstrated that Bcl-2 and Bcl-xl transfected cells exhibited increased sensitivity to 5-FU or HCPT. Flow cytometry demonstrated that the sub G1 cell population increased in Bcl-2/Bcl-xl siRNA co-transfected and Bcl-xl siRNA and Bcl-2 siRNA transfected cells when compared with negative siRNA or untreated cells. The latter trend was strengthened further in the presence of 5-FU or HCPT. 4. Thus, Bcl-2 and Bcl-xl siRNA-mediated gene silencing, in combination with chemotherapy, may be a potential therapeutic strategy against human hepatoblastoma.
authors: Institute of Pharmacy and Pharmacology, University of South China, Hengyang, Hunan, China. lei_xiaoyong@yahoo.com.cn
authors: Xiao-Yong
authors: XY
authors: Lei
authors: Miao
authors: M
authors: Zhong
authors: Lan-Fang
authors: LF
authors: Feng
authors: Bing-Yang
authors: BY
authors: Zhu
authors: Sheng-Song
authors: SS
authors: Tang
authors: Duan-Fang
authors: DF
authors: Liao
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002166:Camptothecin / Q000031:analogs & derivatives / Q000494:pharmacology; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D015536:Down-Regulation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D005434:Flow Cytometry; D005472:Fluorouracil / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D020868:Gene Silencing; D006801:Humans; D008856:Microscopy, Fluorescence; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics*; D013997:Time Factors; D014162:Transfection; D051020:bcl-X Protein / Q000235:genetics* / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051020:bcl-X Protein; C028098:10-hydroxycamptothecin; D053148:Caspase 3; D005472:Fluorouracil; D002166:Camptothecin