siRNA-mediated Bcl-2 and Bcl-xl gene silencing sensitizes human hepatoblastoma cells to chemotherapeutic drugs.
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.
Lei
Xiao-Yong
XY
Institute of Pharmacy and Pharmacology, University of South China, Hengyang, Hunan, China. lei_xiaoyong@yahoo.com.cn
Zhong
Miao
M
Feng
Lan-Fang
LF
Zhu
Bing-Yang
BY
Tang
Sheng-Song
SS
Liao
Duan-Fang
DF
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
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