Slit3 Inhibits Invasion And Metastasis Of Human Fibrosarcoma Cells By Regulating Secretion Of TIMP2

Secretory protein Slits and their receptor Robo were first discovered in the nervous system,which acts as a guide to the axons of neurons during the progress of the nervous system.In recent years,abnormal expression of Slit/Robo signal was found in most of the tumor tissues,suggesting that Slit/Robo signal pathway also plays an significance role in the development of tumors.Current studies have shown that the effect of Slit3 on tumors,whether inhibited or promoted,is signaled by Robo receptors.In the preliminary results of the laboratory,it was found that Slit2 inhibits the proliferation and migration of liver cancer cells,while Robol plays a promoting role,which is different from the reported role of Slit/Robo signaling pathway in inhibiting or promoting the development of tumor cells.We speculate that there may be a mechanism in which a Slit does not depend on the Robo receptor in liver cancer cells.Slit3 is a homolog of Slit2.In previous studies,we have demonstrated that overexpression of Slit3 significantly inhibits the proliferation and metastasis of fibrosarcoma cell line HT1080.This study knocked down Robo1 and Robo4 on the basis of HT1080 cells overexpressing Slit3.The results showed that knockdown of Robo1 and Robo4 receptors further enhanced the inhibitory effect of Slit3 on proliferation,migration and invasion of HT1080 cells,indicating that in HT1080 cells,Slit3 does not function completely through Robo receptors,and may also There are other mechanisms or pathways to perform their functions.In addition,we also found that Slit3 can inhibit tumor cell migration and invasion by inhibiting the expression of MMP9 or promoting the secretion of TIMP2.In order to further explore the mechanism of slit3 promoting TIMP2 secretion,we performed transcriptome sequencing on HT1080-GFP and HT1080-Slit3 cells,and screened three genes related to cell secretion and significantly up-regulated Hsp90B1,Hyou1,Pdia4,etc.The expression of these three genes was low,and the TIMP2 content in the supernatant was detected.The results showed that only the knockdown of Hyou1 gene inhibited the secretion of TIMP2,indicating that the secretion of TIMP2 is closely related to Hyou1.The addition of PI3k/Akt and MAPK signaling pathway inhibitors in HT1080 cells detected TIMP2 levels in cell supernatants,confirming that ERK and JNK are involved in the regulation of TIMP2 secretion by Slit3.This paper firstly proposed a mechanism in which Slit3 may not regulate the secretion of TIMP2 through Robo receptor mediated and affect the invasion and metastasis of HT1080 cells,and further explore the anti-oncogene Slit3 and its inhibitory mechanism on tumor cells.Provide a theoretical reference for inquiry.