Photodynamic Therapy For Colon Cancer Caco-2 Cell Killing Effect And Its Mechanism

Objective: PDT(Photodynamic therapy, PDT) started in the late 19 th century and in recent years has developed a new helper method for cancer treatment. DTPP is a novel lipophilic photosensitizer; tumor cells than quiescent cells express more LDLP, lipophilic DTPP photosensitizers can concentrated on the tumor cells, the mechanisms of tumor treatment reported fewer. DTPP studies focused on cytotoxicity and cellular metabolism, and studied DTPP photosensitizers, in colon cancer Caco-2 cells as a model study of DTPP-PDT concentration of photosensitizer and laser energy density in relation to observation of the apoptosis in colon cancer Caco-2 cells and expression of apoptosis-related protein track designed to provide theoretical evidence for the clinical application of photodynamic therapy for colon cancer.Methods: By MTT method without concentration of photosensitizer and light doses on human colon cancer Caco-2 cell 24 h the cell survival rate after using DAPI staining of cell apoptosis; single cell gel electrophoresis study of different doses of DTPP-PDT colon cancer Caco-2 cells when DNA breaks; analysis of DNA Ladder DTPP-PDT induced apoptosis of Caco-2 cells is detected again; Western Blotting on DTPP-PDT-treated Caco-2 cell proliferation and protein expression of, the proliferating cell nuclear antigen(PCNA) has been evaluated.Results: After Photodynamic therapy on Caco-2 cells after 24 hours of action, suffered different degrees of Caco-2 cell survival rates drop 24 hours of DTPP-PDT, characteristics of apoptosis in Caco-2 cells become increasingly evident, while the placebo group, light group and photosensitizers group with no obvious morphological differences between normal Caco-2 cells cultured in, cell growth is in good condition. Dang photosensitive agent DTPP concentration for 10 μg g/m L, light time 1 minutes and 2 minutes, light energy respectively for 1.2J/cm2 and 2.4J/cm2 Shi, in fluorescent microscope Xia observation Comet image Shi, visible thick set shiny of head and dispersed Dim of tail, and with light power role enhanced, dang cell injury effect over its itself DNA repair Shi, Comet cell number gradually increased, Hui tail gradually elongated. Placebo group, light group and photosensitizers group Caco-2, no significant change. Cells treated with different doses of DTPP-PDT Caco-2 DNA ladder stripe appear after 24 hours. Westernblot analysis showed that DTPP 10ug/ml treated Caco-2 cells, different illumination time, its PCNA downward.Conclusions: When we choose the right kind of photosensitizer concentration and light energy, the DTPP-PDT can be effective in killing colon cancer Caco-2 cell. Cell apoptosis caused by this effect in addition, but also mediated inhibition of Caco-2 cell proliferation.