Isao Tamura

Purpose To investigate whether long noncoding RNAs (lncRNAs) are involved in the development or malignant behavior of ovarian high‐grade serous carcinoma (HGSC), we attempted to identify lncRNAs specific to HGSC. Methods Total RNAs were isolated from HGSC, normal ovarian, and fallopian tube tissue samples and were subjected to a PCR array that can analyze 84 cancer‐associated lncRNAs. The lncRNAs that were upregulated and downregulated in HGSC in comparison to multiple samples of normal ovary and fallopian tube were validated by real‐time RT‐PCR. To infer the function, ovarian cancer cell lines that overexpress the identified lncRNAs were established, and the activation of cell proliferation, migration, and invasion was analyzed. Results Eleven lncRNAs (ACTA2‐AS1, ADAMTS9‐AS2, CBR3‐AS1, HAND2‐AS1, IPW, LINC00312, LINC00887, MEG3, NBR2, TSIX, and XIST) were downregulated in HGSC samples. We established the cell lines that overexpress ADAMTS9‐AS2, CBR3‐AS1, or NBR2. In cell lines overexpressing ADAMTS9‐AS2, cell proliferation was suppressed, but migration and invasion were promoted. In cell lines overexpressing CBR3‐AS1 or NBR2, cell migration tended to be promoted, although cell proliferation and invasion were unchanged. Conclusion We identified eleven lncRNAs that were specifically downregulated in HGSC. Of these, CBR3‐AS1, NBR2, and ADAMTS9‐AS2 had unique functions in the malignant behaviors of HGSC.