Open Access

ARTICLE

Inhibition of apoptosis-regulatory protein Siva-1 reverses multidrug resistance in gastric cancer by targeting PCBP1

by FANBIAO KONG^1,2,#, KUN WU^3,4,#, LIMING PANG^2,#, YULIANG HUANG^2,#, LEI LI³, JING XU², FEITONG LI², YAN QING², ZHONGYU WANG², XIURONG HUANG³, SHENG XU², XIAOGANG ZHONG², ZHOU ZHU², XIAOTONG WANG^3,*, JIANRONG YANG^5,*

1 Department of General Surgery, The First Affiliated Hospital of Jinan University, Guangzhou, 510630, China
2 Department of Colorectal and Anal Surgery, The People’s Hospital of Guangxi Zhuang Autonomous Region & Institute of Minimally Invasive Technology and Applications, Guangxi Academy of Medical Sciences, Nanning, 530021, China
3 Departments of Gastrointestinal, Hernia and Enterofistula Surgery, People’s Hospital of Guangxi Zhuang Autonomous Region & Institute of Minimally Invasive Technology and Applications, Guangxi Academy of Medical Sciences, Nanning, 530021, China
4 Departments of Hepatobiliary and Gastrointestinal Surgery, Minzu Hospital of Guangxi Autonomous Region, Nanning, 530001, China
5 Department of Hepatobiliary, Pancreas and Spleen Surgery, The People’s Hospital of Guangxi Zhuang Autonomous Region & Institute of Minimally Invasive Technology and Applications, Guangxi Academy of Medical Sciences, Nanning, 530021, China

* Corresponding Authors: Xiaotong Wang, ; Jianrong Yang,
# These authors contributed equally

Oncology Research 2022, 30(6), 277-288. https://doi.org/10.32604/or.2022.027301

Received 24 October 2022; Accepted 06 February 2023; Issue published 09 February 2023

Abstract

Introduction: Siva-1, as a pro-apoptotic protein, has been shown to induce extensive apoptosis in a number of different cell lines. In our previous study, we showed that overexpressed Siva-1 decreased the apoptosis of gastric cancer cells. So, we believe that it can also work as an anti-apoptotic protein. The present study aimed to determine the specific role of Siva-1 in anticancer drug resistance in gastric cancer in vivo and in vitro and preliminarily reveal the mechanism. Materials and Methods: A vincristine-resistant MKN-28/VCR gastric cancer cell line with stably downregulated Siva-1 was established. The effect of Siva-1 downregulation on chemotherapeutic drug resistance was assessed by measuring the IC50 and pump rate of doxorubicin. Proliferation, apoptosis of cells, and cell cycle were detected via colony formation assay and flow cytometry, respectively. Additionally, migration and invasion of cells was detected via wound healing and transwell assays. Moreover, we determined in vivo effects of LV-Siva-1-RNAi on tumor size, and apoptotic cells in tumor tissues were detected using TUNEL and hematoxylin and eosin staining. Results: Siva-1 downregulation reduced the pump rate of doxorubicin and enhanced the response to drug treatment. Siva-1 negatively regulated proliferation and promoted apoptosis of cells by potentiality G2-M phase arresting. Inhibition of Siva-1 expression in MKN-28/VCR cells significantly weakened wound healing ability and decreased invasion ability. Poly(C)-binding protein 1 (PCBP1) was identified as a Siva-1-interacting protein in yeast two-hybrid screening. Semiquantitative RTPCR and western blotting revealed that Siva-1 downregulation could inhibit expression of PCBP1, Akt, and NF-κB and eventually decrease the expression of MDR1 and MRP1. Conclusion: The current study demonstrated that the downregulation of Siva-1, which functions as a regulator of MDR1 and MRP1 gene expression in gastric cancer cells by inhibiting PCBP1/Akt/NF-κB signaling pathway expression, enhanced the sensitivity of gastric cancer cells to certain chemotherapies.

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