[Study on inhibitory effect of arsenic trioxide on growth of rat C6 glioma cells].

OBJECTIVE: To explore the inhibitory effect of arsenic trioxide (A(s2)O3) on the growth of rat C6 glioma cells (C6 cells) as well as finding out the feasibility of using As2O3 as chemotherapy of gliomas. METHOD: C6 cells were treated by different dose of As2O3 (1, 2, 4, 6 and 8 micromol L(-1)). MTT assay and staining for PCNA were used for cell proliferation. Cell apoptosis was determined by TUNEL method and Bcl-2 expression was studied by Western blot. Parental rat C6 cells (5 x 10(5)/15 microL) were implanted into right caudate nucleus of male SD rats as control group. Rats bearing cerebral C6 gliomas as treated group were treated with 1 mmol x L(-1) As2O3. The general manifestation, survival time, MRI dynamic scanning and histopathological changes of all rats were observed. RESULT: All the treated cells showed decreased proliferation in vitro as detected by MTT method (P < 0.01) and staining for PCNA. In situ labeling apoptotic DNA fragment of the treated cells demonatrated that the cell apoptosis significantly increased following treatment with As2O3 (P < 0.01). Western blot showed that the expression of Bcl-2 protein was decreased. All rats in control group died of cerebral gliomas within 3 weeks after implantation of C6 cells (17.8 +/- 0.92) d. Eight out of 10 rats in treated group died within 24-36 days (32.1 +/- 1.35) d and other 2 ones kept alive beyond 120 days with one treated rat being totally disappear of the tumor foci and another having a little residue of tumor. CONCLUSION: The result demonstrates the potential efficacy of As2O3 in the treatment of gliomas. It also suggests that As2O3 may be a good candidate for chemotherapy of human gliomas.