Probable Role of Non-exosomal Extracellular Vesicles in Colorectal Cancer Metastasis to Kidney: An In Vitro Cell Line Based Study and Image Analysis

Abstract

Metastasis of colorectal carcinoma to the kidney is a rare phenomenon and least-investigated mechanistically. Both exosomal and non-exosomal vesicles (NEVs) from tumor tissues have been proven to be important metastatic mediators. In this light, the current work focuses on the investigation of the role of NEVs obtained from colorectal cancer cell line HCT116 in developing metastatic traits in normal human embryonic kidney cell line HEK293. ECVs were isolated via filtration method from spent media of HCT116 culture. Dynamic light scattering (DLS) analysis showed ECVs which are obtained as a retentate of 220 nm filters had an average size of 147 nm and hence may be classified as non-exosomal vesicles. NEVs obtained from HCT116 spent media were poured onto compact culture plates of HEK293 cell lines. A systematic image analysis of crystal violet-stained plates was done using the snake model for segmentation by MATLAB and analysis by ImageJ. It is evident from the image analysis data that the number of disseminated cells/colony of cells was more in NEVs treated wells than that of the untreated ones. The average distance of centrifugal cell migration (analogous to invasion) was also found to be higher in case of nECV-treated HEK293 compact cultures. Although early, but in conclusion, it can be said that NEVs from colon carcinoma could be a metastatic mediator for human kidney cells. Secondly, it is indicated that 2D compact culture in combination with inexpensive image analytics can be a potential tool in anti-metaplastic drug discovery applications.