Identification of novel key genes associated with the metastasis of prostate cancer based on bioinformatics prediction and validation

Feifeng Song,Yiwen Zhang,Xiaoping Hu,Haibin Wei,Ping Huang,Yaodong Yi,Zongfu Pan,Xiaochun Zheng

doi:10.1186/s12935-021-02258-3

Abstract

BackgroundMetastatic prostate cancer (PCa) is a lethal tumor. However, the molecular mechanisms underlying PCa progression have not been fully elucidated.MethodsTranscriptome expression profiling and clinical information on primary and metastatic PCa samples were obtained from TCGA. R software was used to screen the DEGs, and LASSO logistical regression method was utilized to identify the pivotal PCa metastasis-related DEGs. The transcriptional expression levels of the key genes were analyzed using the UALCAN database, and the corresponding protein expression were validated by Immunohistochemistry (IHC). Survival analysis of the key genes was performed using the GEPIA database. Wound healing assay and Transwell assay were conducted to determine whether knockdown of the key genes influence the migration and invasion abilities of PCa cells (22Rv1 and PC3). GSEA was performed to predict key genes-mediated signaling pathways for the development of PCa. Western blotting was used to evaluate the expression changes of E-cadherin, Twist1, and Vimentin in PCa cells with the key genes silencing. An in vivo mouse metastatic model for PCa was also generated to verify the important role of ISG15 and CST2 in PCa metastasis.ResultsA comparison between primary and metastatic PCa tissues was conducted, and 19 DEGs were screened. Among these, three key genes were identified that might be closely associated with PCa progression according to the LASSO logistical analysis, namely ISG15, DNAH8, and CST2. Further functional experiments revealed that knockdown of ISG15 and CST2 suppressed wound healing, migration, and invasion of PCa cells. To explore the molecular mechanism of ISG15 and CST2 in the development of PCa, GSEA was performed, and it was found that both genes play crucial roles in cell adhesion molecules, extracellular matrix-receptor interaction, and focal adhesion. Western blotting results exhibited that inhibiting ISG15 and CST2 led to increase the expression of E-cadherin and decrease the expression of Twist1 and Vimentin. Additionally, the metastatic in vivo study demonstrated that both PC3 and 22Rv1 cells expressing with luciferase-shISG15 and luciferase-shCST2 had significantly lower detectable bioluminescence than that in the control PCa cells.ConclusionISG15 and CST2 may participate in PCa metastasis by regulating the epithelial-mesenchymal transition (EMT) signaling pathway. These findings may help to better understand the pathogenetic mechanisms governing PCa and provide promising therapeutic targets for metastatic PCa therapy.

Highlights

Metastatic prostate cancer (PCa) is a lethal tumor
Identification of Differentially expressed gene (DEG) associated with PCa metastasis The procedure of the present study is shown in the following flowchart (Fig. 1a)
To further investigate the importance of these DEGs, Least absolute shrinkage and selection operator (LASSO) logistic regression was performed to select the key genes for PCa metastasis

Summary

Introduction

Metastatic prostate cancer (PCa) is a lethal tumor. the molecular mechanisms underlying PCa progression have not been fully elucidated. The response of patients with metastatic PCa to ADT is only maintained in a short term, and almost all patients develop resistance to ADT therapy within several years [4, 5]. Chemotherapy or radiotherapy, such as mitoxantrone and docetaxel, are commonly adopted for ADT-nonresponsive or metastatic PCa patients, but their efficacy in extending recurrence and decreasing toxicity is limited [6, 7]. There is an urgent need to identify novel molecules associated with PCa metastasis and understand the underlying molecular mechanism, which will be developed as potential therapeutic targets for metastatic PCa therapy

Methods

Results

Discussion

Conclusion