Methylation of the HOXA10 Promoter Directs miR-196b-5p-Dependent Cell Proliferation and Invasion of Gastric Cancer Cells

• Published in: Molecular cancer research 2018-04, Vol.16 (4), p.696-706
• Main Authors: Shao, Linlin, Chen, Zheng, Peng, Dunfa, Soutto, Mohammed, Zhu, Shoumin, Bates, Andreia, Zhang, Shutian, El-Rifai, Wael
• Format: Article
• Language: English
• Subjects: Animal tissues; Animals; Cancer; Cell growth; Cell Line, Tumor; Cell proliferation; Cell Proliferation - drug effects; Chromosome 5; Crosstalk; Decitabine - pharmacology; Demethylation; Deoxyribonucleic acid; DNA; DNA methylation; DNA Methylation - drug effects; Epigenesis, Genetic; Epigenetics; Gastric cancer; Gastric mucosa; Gene expression; Gene Expression Regulation, Neoplastic - drug effects; Homeobox; Homeodomain Proteins - genetics; Humans; Mice; Mice, Knockout; MicroRNAs - genetics; miRNA; Neoplasm Invasiveness; Prognosis; Promoter Regions, Genetic - drug effects; Rodents; Stomach Neoplasms - genetics; Survival Analysis; Trefoil Factor-1 - genetics; Tumorigenesis; Tumors; Up-Regulation - drug effects
• ISSN: 1541-7786; 1557-3125
• DOI: 10.1158/1541-7786.MCR-17-0655

The cross-talk between epigenetics and miRNA expression plays an important role in human tumorigenesis. Herein, the regulation and role of miR-196b-5p in gastric cancer was investigated. qRT-PCR demonstrated that miR-196b-5p is significantly overexpressed in human gastric cancer tissues ( < 0.01). In addition, it was determined that HOXA10, a homeobox family member and host gene for miR-196b-5p, is overexpressed and positively correlated with miR-196b-5p expression levels ( < 0.001). Quantitative pyrosequencing methylation analysis demonstrated significantly lower levels of DNA methylation at the HOXA10 promoter in gastric cancer, as compared with nonneoplastic gastric mucosa specimens. 5-Aza-2'-deoxycytidine treatment confirmed that demethylation of HOXA10 promoter induces the expression of HOXA10 and miR-196b-5p in gastric cancer cell model systems. Using the Tff1 knockout mouse model of gastric neoplasia, hypomethylation and overexpression of HOXA10 and miR-196b-5p in gastric tumors was observed, as compared with normal gastric mucosa from Tff1 wild-type mice. Mechanistically, reconstitution of TFF1 in human gastric cancer cells led to an increased HOXA10 promoter methylation with reduced expression of HOXA10 and miR-196b-5p. Functionally, miR-196b-5p reconstitution promoted human gastric cancer cell proliferation and invasion In summary, the current data demonstrate overexpression of miR-196b-5p in gastric cancer and suggest that TFF1 plays an important role in suppressing the expression of miR-196b-5p by mediating DNA methylation of the HOXA10 promoter. Loss of TFF1 expression may promote proliferation and invasion of gastric cancer cells through induction of promoter hypomethylation and expression of the HOXA10/miR-196b-5p axis. This study indicates that loss of TFF1 promotes the aberrant overexpression of HOXA10 and miR-196b-5p by demethylation of the HOXA10 promoter, which provides a new perspective of TFF1/HOXA10/miR-196b-5p functions in human gastric cancer. .