title: Bcl-XL small interfering RNA enhances sensitivity of Hepg2 hepatocellular carcinoma cells to 5-fluorouracil and hydroxycamptothecin.
abstract: Changes in drug sensitivity in Bcl-XL small interfering RNA (siRNA) transfected Hepg2 hepatocellular carcinoma cells were investigated in this study. Bcl-XL siRNA and negative siRNA expression vector were constructed and stably transfected into Hepg2 cells. Reverse transcription (RT)-PCR, western blot and immunofluorescence were used to detect the target gene expression at mRNA and protein levels. Drug sensitivity of the cells to 5-fluorouracil (5-FU) and hydroxycamptothecin (HCPT) were evaluated with MTT. The Bcl-XL mRNA and protein expression levels in Bcl-XL siRNA transfectants were reduced compared with negative siRNA transfectants or mock cells. MTT results showed that Bcl-XL siRNA transfected cells have a higher cell inhibition rate than negative vector transfected cells or untreated cells after treatment with 13, 130, 1300 and 13,000 mg/L of 5-FU. Bcl-XL siRNA transfected cells also showed increased drug-sensitivity compared with negative vector transfected cells or untreated cells after treatment with 0.18, 0.36, 0.72 and 1.44 mg/L HCPT. Flow cytometry (FCM) results demonstrated that the sub-G1 population increased in the Bcl-XL siRNA group, compared with the negative siRNA group and untreated control group, after the addition of 5-FU (1300 mg/L) and HCPT (0.72 mg/L). siRNA targeting Bcl-XL gene can specifically down-regulate Bcl-XL expression in Hepg2 cells, and can increase spontaneous cell apoptosis and sensitize cells to 5-FU or HCPT.
authors.affiliation: Institute of Pharmacy and Pharmacology, Nanhua University, Hengyang 421001, China. lei_xiaoyong@yahoo.com.cn
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Lei
authors.forename: Miao
authors.initials: M
authors.lastname: Zhong
authors.forename: Lan-Fang
authors.initials: LF
authors.lastname: Feng
authors.forename: Bing-Yang
authors.initials: BY
authors.lastname: Zhu
authors.forename: Sheng-Song
authors.initials: SS
authors.lastname: Tang
authors.forename: Duan-Fang
authors.initials: DF
authors.lastname: Liao
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002166:Camptothecin / Q000031:analogs & derivatives / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy*; D045744:Cell Line, Tumor; D005472:Fluorouracil / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy*; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000502:physiology*; D051020:bcl-X Protein / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D000964:Antimetabolites, Antineoplastic; D000972:Antineoplastic Agents, Phytogenic; C494811:BCL2L1 protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051020:bcl-X Protein; D005472:Fluorouracil; D002166:Camptothecin