Experimental study of a novel photosensitizer for sensitive and multidrug-resistant gastric cancer treatment / 国际生物医学工程杂志

ABSTRACT

Objective To study the photodynamic therapeutical efficacy of a novel photosensitizer DTP on sensitive gastric cancer cells (SGC7901) and vincristine-resistant gastric cancer cells (SGC7901/VCR).Methods The P-gp expression on the SGC7901 and SGC7901/VCR cell membrane was indirectly confirmed by fluorescence microscopy.The survival rates of SGC7901 and SGC7901/VCR cells were evaluated by cell counting kit (CCK-8) after photodynamic therapy with DTP.The intracellular DTP uptake levels of two types of cell were determined using a fluorescence spectrophotometer,and the intracellular DTP distributions were observed by laser scanning confocal microscopy.Results The novel photosensitizer DTP has considerable photodynamic cytotoxic effect on SGC7901 and SGC7901/VCR cells.However,this effect on the SGC7901NCR cells was relatively weak (P＜0.05),and could not be enhanced by P-gp inhibitor verapamil or cyclosporine A(P＞0.05).The DTP uptake level in SGC7901 cells was higher than that in SGC7901/VCR cells (P＜0.05),and could not be enhanced by P-gp inhibitor verapamil and cyclosporin A (P＞0.05).It was found that DTP distributed in the lysosomes of SGC7901 cells and in the lysosomes and mitochondria of SGC7901/VCR cells.Conclusions The novel photosensitizer DTP is not the substrate of multidrug transporter P-gp,and its weaker photodynamic cytotoxic effect on SGC7901/VCR cells is independent of the P-gp overexpression on its cell membrane,which may be related to the distribution of intracellular DTP in the two types of cell.