The Mechanism Of IGF1 Upregulation In CAF Of Colon Cancer Through ?-KG-Dependent Dioxygenase PeiXiaoMeng

In the preliminary study,it was found that the expression of IGF1 in CAF induced by TGF?1 was significantly up-regulated using cytokine microarray antibody and real-time fluorescence quantitative PCR.Immunohistochemistry was used to detect the expression of cytokine IGF1 in CAF from multiple clinical samples of colon cancer.Metabolic reprogramming is involved CAF metabolism,which is mainly embodied in the inhibition of a-KG-dependent dioxygenases activity in the process of tricarboxylic acid cycle.We hypothesized that there might be some relationships between the a-KG-dependent dioxygenases and the regulation of cytokine IGF1.In our previous study,it was observed that ?-KG could inhibited the expression of IGF1,and Fumarate and Succinate could promote the expression of IGF1.The activity of a-KG-dependent dioxygenases were promoted by ?-KG,while the activity of Fumarate and Succinate were inhibited by the?-KG-dependent dioxygenases.Thus,it was hinted that there may have the relationship between the expression of IGF1 and the activity of ?-KG-dependent dioxygenases.In the subsequent experiments,cell lines with the ?-KG-dependent dioxygenases knockdown were constructed,and the expression of IGF1 was increased in both mRNA and protein levels.When the activity of KDM6A was inhibited,the expression of IGF1 also was significantly up-regulated.The expression of KDM6A was low in clinically isolated CAF.The low expression of KDM6A was found to be coincident with the high expression of IGF1 in clinical samples by immunohistochemistry.Subsequently,the mutated cell lines with the active sites of KDM6A histone demethylase was constructed to detect whether KDM6A demethylase regulated the expression of IGF1.The results showed that there was no dramatic difference in the expression of IGF1 between the mutation group and the control which suggested that the effect of KDM6A histone demethylase was not involved in the regulation of IGF 1 expression.Other possible roles of KDM6A in the expression regulation of IGF1 will be further explored.