title: Anticancer drugs are synergistic with freezing in induction of apoptosis in HCC cells.
abstract: Cryotherapy has been shown to be an important therapeutic alternative to surgery in the treatment of hepatocellular carcinoma (HCC). Here, the influence of cryo-chemotherapy on HCC was examined in vitro using the human HCC cell line Bel-7402, a drug-resistant HCC cell line originating from Bel-7402 cells (Bel-7402/R), as well as two control cell lines, the HCC cell line SMMC-7721 and a colorectal tumor cell line HIC-251. Cells were treated with either exposure to different freezing temperatures (ranging from -15 to -80 degrees C for 20 min), exposure to sub-lethal concentrations of anticancer chemotherapy drugs or a combination of cryotherapy and chemotherapy. Cell viability and apoptosis under each condition were investigated. We found that the combined treatment resulted in increases in both cell death and apoptosis compared to either treatment alone. The increased level of apoptosis observed in Bel-7402 cells after cryo-chemotherapy was inhibited in the presence of caspase inhibitors. Furthermore, Bax expression was increased 2- to 3-fold in cells exposed to the combination treatment compared with cells treated by freezing or drugs alone. In contrast, Bcl-2 levels remained constant. Although Bel-7402/R cells originated from the Bel-7402 cell line, they were more sensitive to the freezing procedure than the parental cell line. The level of Bax expression in Bel-7402/R cells was also higher than that observed in the parental cell line. In addition, we found that Bel-7402/R cells had lower levels of survivin mRNA than the parental Bel-7402 cells, in both untreated and treated cells. In conclusion, our data show that in HCC cells, apoptosis induced by cryotherapy can be synergistically enhanced using anticancer drugs.
authors.affiliation: Institute of Liver Surgery, DongFeng Hospital, YunYang Medical College, 10# Daling Road, Shiyan, Hubei 442008, China.
authors.forename: FangJun
authors.initials: F
authors.lastname: Yuan
authors.forename: Wenbo
authors.initials: W
authors.lastname: Zhou
authors.forename: Jifa
authors.initials: J
authors.lastname: Zhang
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Zhang
authors.forename: Can
authors.initials: C
authors.lastname: Zou
authors.forename: Ling
authors.initials: L
authors.lastname: Huang
authors.forename: YouShun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zongqing
authors.initials: Z
authors.lastname: Dai
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000473:pathology / Q000628:therapy*; D016923:Cell Death; D045744:Cell Line, Tumor; D002470:Cell Survival; D003131:Combined Modality Therapy; D017679:Cryotherapy; D005615:Freezing; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008113:Liver Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000628:therapy*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D000077022:Survivin; D015854:Up-Regulation; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D017304:Annexin A5; D000970:Antineoplastic Agents; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D000077022:Survivin; D051028:bcl-2-Associated X Protein