Methylation of an intronic region regulates miR-199a in testicular tumor malignancy

HH Cheung, AJ Davis, TL Lee, AL Pang, S Nagrani… - Oncogene, 2011 - nature.com
HH Cheung, AJ Davis, TL Lee, AL Pang, S Nagrani, OM Rennert, WY Chan
Oncogene, 2011nature.com
In the testicular cancer cell line, NT2, we previously demonstrated that differentially
methylated regions were located in introns or intergenic regions, and postulated these might
regulate non-coding RNAs. Three microRNAs and three small nucleolar RNAs were
differentially methylated; one, miR-199a, was associated with the progression and prognosis
of gastric and ovarian cancers. In this report we document, by epigenomic profiling of
testicular tissue, that miR-199a is transcribed as antisense of dynamin 3 (chromosome 1q24 …
Abstract
In the testicular cancer cell line, NT2, we previously demonstrated that differentially methylated regions were located in introns or intergenic regions, and postulated these might regulate non-coding RNAs. Three microRNAs and three small nucleolar RNAs were differentially methylated; one, miR-199a, was associated with the progression and prognosis of gastric and ovarian cancers. In this report we document, by epigenomic profiling of testicular tissue, that miR-199a is transcribed as antisense of dynamin 3 (chromosome 1q24. 3), and hypermethylation of this region is correlated with miR-199a-5p/3p repression and tumor malignancy. Re-expression of miR-199a in testicular cancer cells led to suppression of cell growth, cancer migration, invasion and metastasis. The miR-199a-5p, one of two mature miRNA species derived from miR-199a, is associated with tumor malignancy. We further identified the embryonal carcinoma antigen podocalyxin-like protein 1 (PODXL), an anti-adhesive protein expressed in aggressive tumors, as a target of miR-199a-5p. We demonstrated PODXL is overexpressed in malignant testicular tumor, and cellular depletion of PODXL resulted in suppression of cancer invasion. The inverse relationship between PODXL and miR-199a-5p expression suggests PODXL is a downstream effector mediating the action of miR199a-5p. This report identifies DNA methylation, miR-199a dysregulation and PODXL as critical factors in tumor malignancy.
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