Cellular Retinoic Acid Binding Protein 2 Is Strikingly Downregulated in Human Esophageal Squamous Cell Carcinoma and Functions as a Tumor Suppressor

PLoS One. 2016 Feb 3;11(2):e0148381. doi: 10.1371/journal.pone.0148381. eCollection 2016.

Abstract

Esophageal squamous cell carcinoma (ESCC) is the predominant pathotype of esophageal carcinoma (EC) in China, especially in Henan province, with poor prognosis and limited 5-year survival rate. Cellular retinoic acid binding protein 2 (CRABP2) is a member of the retinoic acid (RA) and lipocalin/cytosolic fatty-acid binding protein family and plays a completely contrary role in tumorigenesis through the retinoid signaling pathway, depending on the nuclear RA receptors (RAR) and PPARbeta/delta receptors. Presently, the biological role of CRABP2 in the development of ESCC has never been reported. Here, we firstly evaluated the expression of CRABP2 at both mRNA and protein levels and showed that it was remarkably downregulated in clinical ESCC tissues and closely correlated with the occurrence position, pathology, TNM stage, size, infiltration depth and cell differentiation of the tumor. Additionally, the biological function assays demonstrated that CRABP2 acted as a tumor suppressor in esophageal squamous carcinogenesis by significantly inhibiting cell growth, inducing cell apoptosis and blocking cell metastasis both in vitro and in vivo. All in all, our finding simplicate that CRABP2 is possibly an efficient molecular marker for diagnosing and predicting the development of ESCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / genetics
  • Biomarkers, Tumor / biosynthesis*
  • Biomarkers, Tumor / genetics
  • Carcinoma, Squamous Cell / genetics
  • Carcinoma, Squamous Cell / metabolism*
  • Carcinoma, Squamous Cell / pathology
  • Cell Line, Tumor
  • Down-Regulation
  • Esophageal Neoplasms / genetics
  • Esophageal Neoplasms / metabolism*
  • Esophageal Neoplasms / pathology
  • Gene Expression Regulation, Neoplastic*
  • Heterografts
  • Humans
  • Mice
  • Mice, Nude
  • Neoplasm Metastasis
  • Neoplasm Transplantation
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • RNA, Neoplasm / biosynthesis
  • RNA, Neoplasm / genetics
  • Receptors, Retinoic Acid / biosynthesis*
  • Receptors, Retinoic Acid / genetics
  • Tumor Suppressor Proteins / biosynthesis*
  • Tumor Suppressor Proteins / genetics

Substances

  • Biomarkers, Tumor
  • RNA, Messenger
  • RNA, Neoplasm
  • Receptors, Retinoic Acid
  • Tumor Suppressor Proteins
  • retinoic acid binding protein II, cellular

Grants and funding

Funding for this work came from National natural science foundation of China http://www.nsfc.gov.cn/ to Fenyong Sun and Qiuhui Pan, 81272292, 81371913, 81472624, 81472124, 81502425; and Shanghai Young Science and Technology Talents Sailing Program, to Qingyuan Yang, http://www.stcsm.gov.cn/, 15YF1409300.