The effect of As2O3 on induction of apoptosis and inhibition of telomerase activity in colon cancer LS-174T cells / 中华肿瘤杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the impact of arsenic trioxide (As2O3) on human colorectal carcinoma LS-174T cells and their activity of telomerase.</p><p><b>METHODS</b>LS-174T cells and xenograft model of nude mice were treated with As2O3. The inhibitory effect of As2O3 on survival of LS-174T cells was determined by MTT assay. Apoptosis was determined by electron microscopy and fluorescence microscopy. Cell cycle was assessed by flow cytometry. Telomerase activity in LS-174T cells was determined by PCR-ELISA kit.</p><p><b>RESULTS</b>With the increasing concentration of As2O3, the ratio of living cells to dead cells decreased significantly, and the IC50 value was 5.23 micromol/L. Apoptosis curve appeared after 24 h and cells turned to apoptosis in a time-dependent manner. As2O3 inhibited the telomerase activity in cell extraction, obviously in a concentration-dependent and time-dependent manner. Inhibitiory effect of As2O3 on xenograft model of nude mice was observed by tumor volume and weight measurement, showing a significant difference between As2O3 and control groups (P < 0.05).</p><p><b>CONCLUSION</b>Both the experiments in vitro and in vivo showed an inhibitory effect of As2O3 on colonrectal cancer S-174T cell growth, probably by induction of apoptosis and inhibition of telomerase activity.</p>