Abstract: Objective: To investigate the apoptosis-inducing and proliferation-inhibitory effect glycosaminoglycan PG-II extracted from Pinctada martensi Dunker on HeLa cells. Methods: The growth-inhibitory effect was tested by MTT assay. Morphological observations on HeLa cells apoptosis were carried out under inverted microscope and inverted fluorescence microscope. The biochemical changes of HeLa cell DNA during apoptosis were observed by agarose gel electrophoresis. The percentage of apoptotic cells and cell cycle blockage were detected by flow cytometry. Results: PG-Ⅱ could inhibit the proliferation of HeLa cells as determined by MTT assay. Morphological changes in apoptotic HeLa cells were observed under inverted microscope and inverted fluorescence microscope. The agarose gel electropherogram of HeLa cells treated with PG-II for 24 h displayed characteristic DNA ladders from apoptotic HeLa cells with molecular mass between 200 bp and 2000 bp. The results of flow cytometry indicated that PG-Ⅱ could block the HeLa cell cycle at the G1 phase and that the largest blocking effect was achieved after treatment for 24 h at the dose of 100 mg/L with an apoptosis index of 42.6%. Conclusion: PG-Ⅱ can induce apoptosis in HeLa cells and consequently inhibit their proliferation.

Key words: glycosaminoglycan from Pinctada martensi Dunker, HeLa cell, apoptosis