Chromatin , Gene , and RNA Regulation S 100 A 14 : Novel Modulator of Terminal Differentiation in Esophageal Cancer

Aberrant keratinocyte differentiation is a key mechanism in the initiation of cancer. Because activities regulating differentiation exhibit altered or reduced capacity in esophageal cancer cells, it is vital to pinpoint those genes that control epidermal proliferation and terminal differentiation to better understand esophageal carcinogenesis. S100A14 is a member of the S100 calcium-binding protein family and has been suggested to be involved in cell proliferation, apoptosis, and invasion. The present study used immunohistochemistry analysis of S100A14 in clinical specimens of esophageal squamous cell carcinoma (ESCC) to show that decreased S100A14 is strongly correlated with poor differentiation. Furthermore, both mRNA and protein expression of S100A14 was drastically increased upon 12-O-tetra-decanoylphorbol-13-acetate (TPA) and calcium-induced esophageal cancer cell differentiation.Overexpression of S100A14 resulted in aG1-phase cell cycle arrest and promoted calcium-inhibited cell growth. Conversely, decreasing S100A14 expression significantly promoted G1–S transition and prevented the morphologic changes associated with calcium-induced cell differentiation. Molecular investigation demonstrated that S100A14 altered the calcium-induced expression of late markers of differentiation, with the most prominent effect on involucrin (IVL) and filaggrin (FLG). Finally, it was determined that S100A14 is transcriptionally regulated by JunB and that S100A14 and JunB status significantly correlated in ESCC tissue. In summary, these data demonstrate that S100A14 is transcriptionally regulated by JunB and involved in ESCC cell differentiation. Implications: This study further differentiates the molecular mechanism controlling the development and progression of esophageal cancer. Mol Cancer Res; 11(12); 1542–53. 2013 AACR. Introduction Ranking eighth in incidence and sixth in cancer-related mortality worldwide, esophageal cancer is among the most aggressive cancers occurring with such high frequency (1). More than 80% of esophageal cancers occur in developing countries, but these malignancies are particularly prevalent in China and other countries in Asian, where esophageal squamous cell carcinoma (ESCC) is most common (1, 2). Accumulating evidence shows that a variety of biologic abnormalities including altered gene expression, gene mutations, aberrant signaling pathways, and genetic alterations contribute to the development and progression of ESCCs (3). In addition, the disruption of epithelial differentiation may be one of the primary mechanisms for ESCC (4). Our previous studies have clearly shown that a series of genes involved in squamous cell differentiation were coordinately downregulated in ESCCs (5). Among them, S100 calciumbinding proteins have attracted additional attention as they are implicated in a variety of biologic events closely related to tumorigenesis and cancer progression. Most S100 proteins are clustered at the chromosomal region 1q21 and constitute important components of the epidermal differentiation complex (EDC; ref. 6). S100 proteins are therefore involved in the process of terminal differentiation of human epidermis and have been implicated in cancer as altered expression levels of several S100 proteins have been reported to correlate with tumor differentiation including ESCCs (7–14). We have recently reported on the role of the S100 family member, S100A14, in driving esophageal carcinogenesis, showing that extracellular S100A14 affects esophageal cancer cell proliferation and apoptosis via interaction with RAGE, and intracellular S100A14 regulates cell invasion by MMP2 in a p53-dependent manner (15, 16). Moreover, the 461G>A SNP located in the 50-untranslated region (UTR) of S100A14 is associated with ESCC susceptibility in aChinese Authors' Affiliations: State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; and Department of Molecular and Cellular Biochemistry and the Comprehensive Cancer Center, The Ohio State University College of Medicine, Columbus, Ohio Note: Supplementary data for this article are available at Molecular Cancer Research Online (http://mcr.aacrjournals.org/). Corresponding Author: Zhihua Liu, State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences, Beijing 100021, China. Phone: 8610-87788490; Fax: 861067723789; E-mail: liuzh@cicams.ac. cn doi: 10.1158/1541-7786.MCR-13-0317 2013 American Association for Cancer Research. Molecular Cancer Research Mol Cancer Res; 11(12) December 2013 1542 on June 16, 2017. © 2013 American Association for Cancer Research. mcr.aacrjournals. org Downloaded from Published OnlineFirst October 9, 2013; DOI: 10.1158/1541-7786.MCR-13-0317