Phosphorylation of CAP1 regulates lung cancer proliferation, migration, and invasion

Jie Zeng,Shuanshuan Xie,Long Liang,Xuan Li,Changhui Wang,Hongxia Duan

doi:10.1007/s00432-021-03819-9

Abstract

PurposeCyclase-associated protein 1 (CAP1) is a ubiquitous protein which regulates actin dynamics. Previous studies have shown that S308 and S310 are the two major phosphorylated sites in human CAP1. In the present study, we aimed to investigate the role of CAP1 phosphorylation in lung cancer.MethodsMassive bioinformatics analysis was applied to determine CAP1’s role in different cancers and especially in lung cancer. Lung cancer patients’ serum and tissue were collected and analyzed in consideration of clinical background. CAP1 shRNA-lentivirus and siRNA were applied to CAP1 gene knockdown, and plasmids were constructed for CAP1 phosphorylation and de-phosphorylation. Microarray analysis was used for CAP1-associated difference analysis. Both in vitro and in vivo experiments were performed to investigate the roles of CAP1 phosphorylation and de-phosphorylation in lung cancer A549 cells.ResultsCAP1 is a kind of cancer-related protein. Its mRNA was overexpressed in most types of cancer tissues when compared with normal tissues. CAP1 high expression correlated with poor prognosis. Our results showed that serum CAP1 protein concentrations were significantly upregulated in non-small cell lung cancer (NSCLC) patients when compared with the healthy control group, higher serum CAP1 protein concentration correlated with shorter overall survival (OS) in NSCLC patients, and higher pCAP1 and CAP1 protein level were observed in lung cancer patients’ tumor tissue compared with adjacent normal tissue. Knockdown CAP1 in A549 cells can inhibit proliferation and migration, and the effect is validated in H1975 cells. It can also lead to an increase ratio of F-actin/G-actin. In addition, phosphorylated S308 and S310 in CAP1 promoted lung cancer cell proliferation, migration, and metastasis both in vitro and in vivo. When de-phosphorylated, these two sites in CAP1 showed the opposite effect. Phosphorylation of CAP1 can promote epithelial–mesenchymal transition (EMT).ConclusionThese findings indicated that CAP1 phosphorylation can promote lung cancer proliferation, migration, and invasion. Phosphorylation sites of CAP1 might be a novel target for lung cancer treatment.

Highlights

Global statistical data show that of newly diagnosed cancer cases, lung cancer is the most common and that it is the leading cause of death among the 36 cancers in the world (Bray et al 2018)
The p value was 0.012, HR was 1.5, and p (HR) was 0.012. These results revealed that Cyclase-associated protein 1 (CAP1)-high-expression correlated with poor diagnosis in non-small cell lung cancer (NSCLC) patients
We looked for more information on CAP1 expression in NSCLC from UALCAN

Summary

Introduction

Global statistical data show that of newly diagnosed cancer cases, lung cancer is the most common and that it is the leading cause of death among the 36 cancers in the world (Bray et al 2018). CAP1 is a cancer-associated protein, and according to UniProt and GO-Cellular component annotation, human CAP1 has an extensive expression. It is well known as a cytoskeleton protein, but it has been observed to be expressed in the membrane and can secrete to the extracellular region (Hasan and Zhou 2019). We investigated the role of CAP1 phosphorylation in lung cancer A549 cells and validated CAP1’s role in H1975 cells. Both in vitro and in vivo experiments showed that S308/S310 phosphorylation in CAP1 facilitated proliferation and metastasis of lung cancer cells. We found that phosphorylation of CAP1 promoted EMT, thereby facilitating lung cancer cells’ metastasis

Objectives

Methods

Results

Discussion

Conclusion