Activation of the Ig Iα1 promoter by the transcription factor Ets-1 triggers Ig Iα1-Cα1 germline transcription in epithelial cancer cells.

Abstract

Immunoglobulins (Igs) are known to be synthesized and secreted only by B lymphocytes. Class switch recombination (CSR) is a key event that enables B cells to express Igs, and one of the crucial steps for CSR initiation is the germline transcription of Ig genes. Surprisingly, recent studies have demonstrated that the Ig genes are also expressed in some epithelial cancer cells; however, the mechanisms underlying how cancer cells initiate CSR and express Igs are still unknown. In this study, we confirmed that the Ig Iα1 promoter in cancer cell lines was activated by the Ets-1 transcription factor, and the activity of the Ig Iα1 promoter and Ig Iα1-Cα1 germline transcription were attenuated after knockdown of Ets-1 by specific small interfering RNAs (siRNA). Furthermore, the expression of Ets-1 and Igα heavy chain in cancer cells was dose dependently upregulated by TGF-β1. These results indicate that activation of the Ig Iα1 promoter by the transcription factor Ets-1 is a critical pathway and provides a novel mechanism for Ig expression in non-B cell cancers.

• Authors: Zhi Duan, Hui Zheng, San Xu, Yiqun Jiang, Haidan Liu, Ming Li, Duosha Hu, Wei Li, Ann M Bode, Zigang Dong, Ya Cao
• Journal: Cellular & molecular immunology (Cell Mol Immunol) Vol. 11 Issue 2 Pg. 197-205 (Mar 2014) ISSN: 2042-0226 [Electronic] China
• PMID: 24185710 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• ETS1 protein, human
• Immunoglobulin A
• Immunoglobulin Constant Regions
• Immunoglobulin alpha-Chains
• Proto-Oncogene Protein c-ets-1
• RNA, Small Interfering
• Transforming Growth Factor beta1

Topics

• Carcinoma (immunology)
• Epithelial Cells (immunology)
• Gene Expression Regulation, Neoplastic (genetics)
• HeLa Cells
• Humans
• Immunoglobulin A (genetics, metabolism)
• Immunoglobulin Constant Regions (genetics, metabolism)
• Immunoglobulin alpha-Chains (genetics, metabolism)
• Organ Specificity
• Promoter Regions, Genetic (genetics)
• Proto-Oncogene Protein c-ets-1 (genetics, metabolism)
• RNA, Small Interfering (genetics)
• Transcriptional Activation (genetics)
• Transforming Growth Factor beta1 (immunology)
• Up-Regulation