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Anti‐cancer activity of anti‐p185 HER‐2 ricin A chain immunotoxin on gastric cancer cells
Author(s) -
Zhou XinXin,
Ji Feng,
Zhao JingLi,
Cheng LinFang,
Xu ChengFu
Publication year - 2010
Publication title -
journal of gastroenterology and hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.214
H-Index - 130
eISSN - 1440-1746
pISSN - 0815-9319
DOI - 10.1111/j.1440-1746.2010.06287.x
Subject(s) - immunotoxin , propidium iodide , microbiology and biotechnology , cancer cell , flow cytometry , annexin , apoptosis , cancer research , medicine , monoclonal antibody , cancer , antibody , biology , programmed cell death , biochemistry , immunology
Background and Aim: Overexpression of the human epidermal growth factor receptor 2 (HER‐2) protein has been detected in gastric cancer and has been associated with an unfavorable prognosis. We investigated the anti‐cancer effects of anti‐p185 HER‐2 ricin A chain (RTA) immunotoxin, alone or in combination with 5‐flurouracil on SGC7901‐HER‐2+ cells. Methods: SGC7901‐HER‐2+ cells were obtained by transfecting SGC7901 cells with HER‐2‐pcDNA3.1. Anti‐p185 HER‐2 ‐RTA was prepared by chemical conjugation of anti‐HER‐2 monoclonal antibody (mAb) and RTA. The SGC7901‐HER‐2+ cells were incubated with RTA, anti‐p185 HER‐2 ‐RTA, and/or 5‐flurouracil. The effects of drugs on cells were evaluated by MTT assay and Annexin V‐fluorescein isothiocyanate and propidium iodide double staining flow cytometry. The expression of caspase‐3, caspase‐9, cyclooxygenase‐2, and nuclear factor‐κB/p65 were assayed by western blot. SGC7901‐HER‐2+ cells were transplanted into BALB/c nude mice to produce solid tumors in an attempt to study the immunotoxin activity in vivo . Results: In vitro , anti‐p185 HER‐2 ‐RTA inhibited cell growth and induced apoptosis in SGC7901‐HER‐2+ cells. Anti‐p185 HER‐2 ‐RTA enhanced caspase‐3 and caspase‐9 activity, while downregulating the expression of cyclooxygenase‐2 and nuclear factor‐κB/p65. Its combination with 5‐flurouracil further inhibited the growth of SGC7901‐HER‐2+ cells. In vivo , our data showed that anti‐p185 HER‐2 ‐RTA significantly inhibited the growth of SGC7901‐HER‐2+ cells‐transplanted tumors. Conclusions: Anti‐p185 HER‐2 ‐RTA inhibits the growth of SGC7901‐HER‐2+ cells. The effect may be related to the activation of caspase‐3 and caspase‐9 and inhibition of cyclooxygenase‐2 and nuclear factor‐κB/p65. Anti‐p185 HER‐2 ‐RTA plus 5‐FU enhance anti‐cancer activity, suggesting useful clues for further study for the treatment of HER‐2 positive gastric cancers.