Effects Of Meta-Tetrahydroxyphenylchlorin Photodynamic Therapy On The Cytoskeleton Of Colon Cancer With Different Metastatic Potential

Objective: To observe the effects of meta-tetrahydroxyphenylchlorin(m-THPC)photodynamic therapy(PDT)on cytoskeleton proteins of colon cancer SW480 and SW620 cells with different metastatic potential,which provides a scientific basis for further clarifying the mechanism of m-THPC photodynamic therapy for colorectal cancer.Methods: 1.Subcellular localization of m-THPC in SW480 and SW620 cells of colon cancer was observed with confocal laser scanning microscope;2.Morphology of SW480 and SW620 cells after m-THPC-PDT was observed with inverted fluorescence microscope;3.The survival rate of SW480 and SW620 cells after m-THPC-PDT and Jasplakinolide(JAS)combined m-THPC-PDT was detected by using MTT;4.Flow cytometry was used to detect the apoptosis rate of SW480 and SW620 cells after m-THPC-PDT;5.Western Blot was used to detect the expression of cytoskeleton proteins and apoptosis related protein in SW480 and SW620 cells after m-THPC-PDT and JAS combined m-THPC-PDT;6.The scratch test was used to detect the migration of SW480 and SW620 cells after JAS combined m-THPC-PDT.Results: 1.m-THPC was mainly located in the endoplasmic reticulum and lysosome of colon cancer SW480 cell,but mainly located in mitochondria and lysosome of colon cancer SW620 cell;2.After m-THPC-PDT,with the increase of m-THPC concentration,the normal morphology of SW480 and SW620 cells gradually changed,and showed typical morphological features of apoptosis;3.After m-THPC-PDT,survival rate of SW480 and SW620 cells decreased with the increase of m-THPC concentration(P<0.05);4.After m-THPC-PDT,apoptotic rate of SW480 and SW620 cells increased with the increase of m-THPC concentration(P<0.05),and the apoptotic rate of SW480 and SW620 cells varied greatly when m-THPC concentration was 8μg/ml(60.07% and 11.20%,P<0.05);the expression of Bcl-2 decreased with the increase ofm-THPC concentration(P<0.05);5.After m-THPC-PDT,the expression of F-actin,α-tubulin,β-tubulin and cytokeratin18 in SW480 cell decreased with the increase of m-THPC concentration(P<0.05);the expression of F-actin,α-tubulin and β-tubulin in SW620 cell decreased with the increase of m-THPC concentration(P<0.05),while the expression of cytokeratin18 increased(P<0.05);6.Compared to m-THPC-PDT group,the cell survival rate of SW480 and SW620 for JAS+m-THPC-PDT group did not changed(P>0.05);7.Compared to m-THPC-PDT group,expression of F-actin in SW480 decreased for JAS+m-THPC-PDT group(P<0.05),while Bcl-2 was not significantly decreased(P>0.05);however expression of F-actin and Bcl-2 in SW620 cell decreased for JAS+m-THPC-PDT group(P<0.05).8.The migration ability of SW480 and SW620 cells increased in group JAS+m-THPC-PDT compared to group m-THPC-PDT.Conclusions: 1.Photosensitizer m-THPC mainly localized in the endoplasmic reticulum and lysosome of SW480 cells,and mainly localized in lysosome and mitochondria of SW620 cells,location of the same photosensitizer in different cells may be different.2.In the process of m-THPC-PDT,with the increased of m-THPC concentration,the survival rate of two cells decreased,and the rate of apoptosis increased,m-THPC concentration was one of the key factor for determine the effect of m-THPC-PDT.3.m-THPC-PDT caused cytoskeleton destructions of two cells,especially the microfilaments and microtubules.4.In SW480 cells,microtubules may participate in the process of apoptosis induced by m-THPC-PDT,and microfilament may participate in the process of inhibiting cell migration by m-THPC-PDT;in SW620 cells,microfilament may be involved in the process of apoptosis and the inhibition of cell migration induced by m-THPC-PDT.