Valproic acid exhibits anti-tumor activity selectively against EGFR/ErbB2/ErbB3-coexpressing pancreatic cancer via induction of ErbB family members-targeting microRNAs

• Published in: Journal of experimental & clinical cancer research Vol. 38; no. 1; p. 150
• Main Authors: Lin, Tingting, Ren, Qun, Zuo, Weimin, Jia, Ruxue, Xie, Linhui, Lin, Rong, Zhao, Hu, Chen, Jin, Lei, Yan, Wang, Ping, Dong, Huiyue, Huang, Lianghu, Cai, Jinquan, Peng, Yonghai, Yu, Zongyang, Tan, Jianming, Wang, Shuiliang
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 08-04-2019; BioMed Central; BMC
• Subjects: Acids; Apoptosis; Breast cancer; Cancer cells; Cancer patients; Cell culture; DNA; DNA methylation; Enzyme-linked immunosorbent assay; Enzymes; Epidermal growth factor; ErbB family members; Exhibitions; Gene amplification; Gene expression; Genes; Genetic research; Immunoglobulins; Kinases; Messenger RNA; MicroRNA; microRNAs; Mutation; Pancreatic cancer; Proteins; Tumors; Valproic acid; United States > US; microRNAs; Valproic acid; Pancreatic cancer; ErbB family members
• ISSN: 1756-9966; 0392-9078; 1756-9966
• DOI: 10.1186/s13046-019-1160-9

Deregulated ErbB signaling plays an important role in tumorigenesis of pancreatic cancer. However, patients with pancreatic cancer benefit little from current existed therapies targeting the ErbB signaling. Here, we explore the potential anti-tumor activity of Valproic acid against pancreatic cancer via targeting ErbB family members.
Cell viability assay and apoptosis evaluation were carried out to determine the efficacy of VPA on pancreatic cancer cells. Western blot analyses were performed to determine the expression and activation of proteins. Apoptosis enzyme-linked immunosorbent assay was used to quantify cytoplasmic histone associated DNA fragments. Lentiviral expression system was used to introduce overexpression of exogeneous genes or gene-targeting short hairpin RNAs (shRNAs). qRT-PCR was carried out to analyze the mRNAs and miRNAs expression levels. Tumor xenograft model was established to evaluate the in vivo anti-pancreatic cancer activity of VPA.
VPA preferentially inhibited cell proliferation/survival of, and induced apoptosis in EGFR/ErbB2/ErbB3-coexpressing pancreatic cancer cells within its clinically achievable range [40~100 mg/L (0.24~0.6 mmol/L)]. Mechanistic investigations revealed that VPA treatment resulted in simultaneous significant down-regulation of EGFR, ErbB2, and ErbB3 in pancreatic cancer cells likely via induction of ErbB family members-targeting microRNAs. Moreover, the anti-pancreatic cancer activity of VPA was further validated in tumor xenograft model.
Our data strongly suggest that VPA may be added to the treatment regimens for pancreatic cancer patients with co-overexpression of the ErbB family members.