Actin Gamma 1 Promotes Metastasis And Proliferation Of Prostate Cancer

ObjectiveWe want to investigate the effect of abnormal expression of ACTG1(Actin gamma 1)on prostate cell proliferation and metastasis during prostate cancer progression,and to explore the molecular mechanism of how to regulate it.MethodsFirst,serum levels of ACTG1 were found to be higher in patients with advanced prostate cancer by proteomics and ELISA in patients with early prostate cancer and those with advanced metastatic prostate cancer.Then,the expression of ACTG1 in normal prostate tissues and prostate cancer tissues was predicted in the TCGA database.The expression of ACTG1 in prostate hyperplasia,early prostate cancer and advanced prostate cancer was detected by immunohistochemistry,and then by RT-q PCR and Western Blot technique was used to detect the difference in expression between normal prostate cell line RWP-1 and different malignant prostate cancer cell lines LNCa P,C4-2,DU-145 and PC-3,and to determine the role of ACTG1 in prostate cancer.Using si RNA to knock down ACTG1 in prostate cancer cell lines PC-3 and DU-145,respectively,to reduce the expression of ACTG1,and then observe and compare the behavioral changes of prostate cancer cells before and after ACTG1 knockdown.The changes of cell migration ability and invasion ability were detected by scratch test and Transwell test,respectively,and the cell proliferation ability was detected by CCK-8 test.To further explore how ACTG1 affects the metastasis of prostate cancer cells,we examined changes in the levels of EMT(epithelial-mesenchymal transition)molecular markers in cell lines that knocked down ACTG1.By querying a large number of literatures,we learned that the MAPK/ERK pathway has a significant effect on EMT,so we examined changes in ERK1/2 phosphorylation levels after knockdown of ACTG1.In addition,we used ERK1/2 phosphorylation inhibitors to inhibit phosphorylation of ERK1/2 in prostate cancer cell lines,knocking down or not knocking down ACTG1,and then detecting changes in cell migration and invasion by Transwell assay.Finally,we transfected theACTG1 knockdown lentivirus and the empty virus in the DU-145 cell line.After screening the stably transfected cell line with puromycin,the screened cells were inoculated into the right upper extremity of 4 weeks old nude mice.Next,after the tumor is formed,the position and size of the tumor are observed by a small animal imaging system,and then the tumor is removed,and a wax block is prepared,and the level of EMT markers in different groups is detected by immunohistochemistry.ResultACTG1 was found to have higher serum levels in patients with advanced prostate cancer by ELISA.The TCGA database also showed that ACTG1 was less expressed in normal prostate tissue than in prostate cancer.We demonstrate that ACTG1 is highly expressed in the aggressive prostate cancer cell lines DU-145 and PC-3.Moreover,we found that ACTG1 is more highly expressed in high-grade prostate cancer than in benign prostatic hyperplasia or in low-grade prostate cancer tissues.When ACTG1 expression was knocked down in DU-145 and PC-3 cells,we noticed that the proliferative and metastatic abilities of prostate cancer cells were repressed.We also showed that ACTG1 knockdown was able to reverse EMT and reduce the expression of its associated markers.EMT plays an important role in facilitating metastasis of a variety of tumors including prostate cancer.We also found that silencing ACTG1 decreased the level of p-ERK.Furthermore,inhibiting the MAPK/ERK signaling pathway with U0126 reduced ACTG1-mediated EMT,cell migration,and cell proliferation.This suggests that ACTG1 utilizes MAPK/ERK signaling pathway to induce EMT,thereby promoting metastasis in prostate cancer.However,the exact mechanism by which ACTG1 mediates prostate cancer cell proliferation remains unclear and needs to be further studied.ConclusionOur data demonstrates that ACTG1 is overexpressed in prostate cancer cells.ACTG1 induces EMT and metastasis in prostate cancer cells via the MAPK/ERK pathway.We also showed that ACTG1 stimulates the growth of prostate cancer cells in vitro and prostate tumor growth in vivo.The present study providesevidence showing that ACTG1 may be potentially valuable for early detection and therapy of prostate cancer.