Chitosan, a multipurpose
biomaterial, has been shown to exert effects against several types of
cancer including
oral cancer. However, the mechanisms underlying the anticancer activities of
chitosan on
oral squamous cell carcinoma (SCC) cells remain largely unknown. The present study aimed to compare the effects of low-molecular-weight
chitosan (LMWC) and
cisplatin on oral SCC Ca9-22 and non-
cancer keratinocyte HaCaT cell lines. Cell viability and cell cycle profiles were measured by MTT assay and
laser scanning cytometry, respectively. Apoptosis was examined by TUNEL assay and electron microscopy, followed by analysis of
caspase activity. LMWC exhibited cytotoxic effects on Ca9-22, but not HaCaT cells, whereas
cisplatin induced apoptosis in both types of cells. Exposure of Ca9-22 cells to LMWC led to G1/S cell cycle arrest and an increase of TUNEL-positive cells accompanied by an early apoptotic cell morphology and subtle increases of
caspase activity. Short-term LMWC exposure was less cytotoxic to HaCaT cells than to Ca9-22 cells, and anticancer activity was exerted through induction of apoptosis and cell cycle arrest, suggesting that LMWC could be a promising natural
anticancer agent with fewer side effects on normal cells.