Purpose  Recent studies have emphasized etiogenic correlations between microRNA (miRNA) deregulation and cancer development. In conjunctival MALT (mucosa-associated lymphoid tissue, MALT) lymphoma, the differentially expressed miRNA remained largely undefined.
Methods  miRNA expression profile of surgically removed conjunctival MALT lymphoma tissue and their adjacent conjunctival control from 4 patients were identified using high throughput miRNA microarray. The deregulated miRNAs were confirmed in additional 10 samples using quantitative RT-PCR. The functional effect of miR-200 was examined further. A luciferase reporter assay was performed to confirm the predicted target.
Results  miR-150 and -155 are markedly upregulated and miR-184, -200a, -200b, -200c, and -205 are markedly repressed in all the tumor samples compared to their matched adjacent conjunctival controls. Moreover, cyclin E2, whose expression accelerates G1 progression and was reported to be overexpressed in various tumors, is identified as a target of miR-200a, -200b, and -200c.
Conclusions  Our results revealed the specific deregulated miRNAs in conjunctival MALT lymphoma and underscored the repressed miR-200 might contribute to the upregulation of cyclin E2.