Experiment Studies Of Antitumor Action Of BPI-1095 And Its Mechanism Of Action On HCT-8 Cell

Objective: Colorectal cancer is one of the most common malignant gastrointestinal cancers, and is the second leading cause of cancer death in many developed countries. Rencent investigations have shown that colorectal cancer ranks the fourth among the most common cancers in China and the incidence has been on the rise in the past years. With more attention to early discovery and diagnosis, there is an obvious decrease of its mortality, yet we still have lots of trouble in treating it. Finding new and effective methods to decrease its incidence and mortality is badly needed. ASA, showed by lots of evidence, has the effect of suppressing tumor proliferation and inducing apoptosis besides its effect of anti-inflammation, relieving pain, and anti-coagulation of platelets. ASA long-term using can obviously decrease the mortality of colonic adenocarcinoma. BPI-1095, consisting of a known nonsteroidal anti-inflammatory drug (ASA) and a nitric oxide-releasing group, can breakdown into ASA and NO in vivo. As it combines the pharmacological activity of ASA and NO, it can prevent tumorigenesis and tumor-development. Compared with its parent compound (ASA), BPI-1095 can not only improve the pharmacologic effects, but also be safer to all over the body system. Our experiments try to observe the effects of BPI-1095 on many cancer cells (including HCT-8), and to explore the underlining mechanism. Methods: The growth inhibition rate of BPI-1095 on several cell lines (including HCT-8 cell line) was evaluated by MTT reduction assay; Apoptosis induced by BPI-1095 on HCT-8 cell was determined by applying light microscope, Fluorescence microscope and agarose gel eletrophoresis. The effect of BPI-1095 on cell cycle and apoptotic rate measured by flow cytometry (FCM); In vivo study on the pharmacological activity of BPI-1095 was performed by using athymic mouse transplantation tumor model. Results: (1) The inhibition rate of BPI-1095 on several cells'proliferation increased as its concentration increasing; (2) The inhibition rate of BPI-1095 on HCT-8 cell proliferation increased as incubation time and BPI-1095 concentration increasing; (3) The analysis results of cell cycle indicates, treated with various concentration BPI-1095, the percentage of G1 phase increased from 41.1% to 59.5%; the percentage of G2 phase decreased from 13.3% to 1.2%; the percentage of S phase decreased from 45.6% to 39.3%; (4) The FCM result showed that the apoptosis rate of HCT-8 increased as BPI-1095 concentration increasing; (5) Apoptotic morphological change and DNA ladder electrophoresis fragment on HCT-8 cell were observed under the concentrations of 0.1~0.4 mol·L-1 BPI-1095 for 48 hours; (6) In vivo experiments showed that the tumorweight and size of all the treated groups were decreased as compared with that of the blank control group. The mean tumor weights of BPI-1095 groups were all significantly lower than that of control group. Conclusions: From all above results, we conclude that BPI-1095 exhibits a potent antitumor activity both in vivo and in vitro model: BPI-1095 has inhibitory effect on several cancer cell lines. Especially the inhibition rate was significantly increased as the time and dose increasing. Compared with its parent there is an obvious superiority. Inducing apoptosis may be one of mechanisms by which BPI-1095 exerts its tumor chemopreventive and therapeutic. And the mechanism of BPI-1095 inducing apoptosis may be related to disturb cell cycle.