Diethylaminoethyl chitosan induces apoptosis in HeLa cells via activation of caspase-3 and p53 expression

In our previous study, diethylaminoethyl chitosan (DEAEC) was found to inhibit the viability of HeLa cells, a human uterine cervix cancer cell line. To identify the anti-proliferation activity of DEAEC, its mode of action was studied in further detail in HeLa cells. After incubation for 24 h, DEAEC had significantly inhibited HeLa cell growth with an IC50 of 23.2 μg/mL and showed strong apoptotic activity. After Hoechst 33258 staining, morphological changes and DNA degradation were observed. Cell cycle analysis and an Annexin V assay by flow cytometry revealed that DEAEC induced apoptosis in the HeLa cells by sub-G1 involving early stage apoptosis. RT-PCR and Western blotting analysis results showed that DEAEC induced apoptosis in the HeLa cells via up-regulation of caspase family enzyme (caspase-3, -8 and -9), p53, and Bax protein expressions, and down-regulation of Bcl-2 protein expression.