Integrated, genome-wide screening for hypomethylated oncogenes in salivary gland adenoid cystic carcinoma

Chunbo Shao, Wenyue Sun, Marietta Tan, Chad A. Glazer, Sheetal Bhan, Xiaoli Zhong, Carole Fakhry, Rajni Sharma, William H. Westra, Mohammad O. Hoque, Christopher A. Moskaluk, David Sidransky, Joseph A. Califano, Patrick K. Ha

Research output: Contribution to journalArticle

Abstract

Purpose: Salivary gland adenoid cystic carcinoma (ACC) is a rare malignancy that is poorly understood. To look for relevant oncogene candidates under the control of promoter methylation, an integrated, genome-wide screen was conducted. Experimental Design: Global demethylation of normal salivary gland cell strains using 5-aza-2′-deoxycytidine (5-aza-dC) and trichostatin A (TSA), followed by expression array analysis was conducted. ACC-specific expression profiling was generated using expression microarray analysis of primary ACC and normal samples. Next, the two profiles were integrated to identify a subset of genes for further validation of promoter demethylation in ACC versus normal. Finally, promising candidates were further validated for mRNA, protein, and promoter methylation levels in larger ACC cohorts. Functional validation was then conducted in cancer cell lines. Results: We found 159 genes that were significantly re-expressed after 5-aza-dC/TSA treatment and overexpressed in ACC. After initial validation, eight candidates showed hypomethylation in ACC: AQP1, CECR1, C1QR1, CTAG2, P53AIP1, TDRD12, BEX1, and DYNLT3. Aquaporin 1 (AQP1) showed the most significant hypomethylation and was further validated. AQP1 hypomethylation in ACC was confirmed with two independent cohorts. Of note, there was significant overexpression of AQP1 in both mRNA and protein in the paraffinembedded ACC cohort. Furthermore, AQP1 was upregulated in 5-aza-dC/TSA-treated SACC83. Finally, AQP1 promoted cell proliferation and colony formation in SACC83. Conclusions: Our integrated, genome-wide screening method proved to be an effective strategy for detecting novel oncogenes in ACC. AQP1 is a promising oncogene candidate for ACC and is transcriptionally regulated by promoter hypomethylation.

Original languageEnglish (US)
Pages (from-to)4320-4330
Number of pages11
JournalClinical Cancer Research
Volume17
Issue number13
DOIs
StatePublished - Jul 1 2011

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Fingerprint Dive into the research topics of 'Integrated, genome-wide screening for hypomethylated oncogenes in salivary gland adenoid cystic carcinoma'. Together they form a unique fingerprint.

  • Cite this

    Shao, C., Sun, W., Tan, M., Glazer, C. A., Bhan, S., Zhong, X., Fakhry, C., Sharma, R., Westra, W. H., Hoque, M. O., Moskaluk, C. A., Sidransky, D., Califano, J. A., & Ha, P. K. (2011). Integrated, genome-wide screening for hypomethylated oncogenes in salivary gland adenoid cystic carcinoma. Clinical Cancer Research, 17(13), 4320-4330. https://doi.org/10.1158/1078-0432.CCR-10-2992