Alterations of several microRNA (miRNA) have been linked to cancer development and its biology. To search for unique miRNA that might play a role in the development of anaplastic thyroid carcinoma (ATC), we examined the expression of multiple miRNA and their functional effects on target genes in human thyroid carcinoma cell lines. We quantitatively evaluated the expression of multiple miRNA in 10 ATC and five papillary thyroid carcinoma (PTC) cell lines, as well as primary tumors from 11 thyroid carcinoma patients (three ATC and eight PTC), using the stem-loop-mediated reverse transcription real-time polymerase chain reaction method. We also examined the target gene specificity of unique miRNA that showed differences in expression between ATC and PTC cell lines.

Abstract. Aberrant expression of class III ß-tubulin, TUBB3, has been reported to be one of the important mechanisms responsible for taxane resistance in diverse human malignancies. We investigated aberrant TUBB3 expression and its epigenetic modification in 66 primary tumors and 3 cell lines (OVCAR-3, JHOC-5 and JHOC-8) of ovarian cancers. Overexpression of TUBB3 protein was observed in 56 (85%) of the 66 ovarian cancers, and was significantly associated with aggressive tumor behavior (advanced stage, presence of ascites, suboptimal cytoreduction at surgery and presence of lymph node metastasis) (P<0.05). Responses to treatment with a demethylating agent (5-aza-2'-deoxycytidine, 5-Aza-CdR) and a histone deacetylase inhibitor (4-phenylbutyric acid, PBA) differed among the ovarian cancer cell lines. In 2 cell lines with weak expression of TUBB3 protein (OVCAR-3 and JHOC-8), TUBB3 induction was independently induced by treatment with 5-Aza-CdR (JHOC-8) or PBA (OVCAR-3), while neither agent markedly altered TUBB3 mRNA/protein expression in a strongly TUBB3-expressing cell line (JHOC-5). A CpG island within intron 1 was hypermethylated in 1 cell line (JHOC-8) that expressed TUBB3 weakly and required 5-Aza-CdR treatment for gene expression. A CpG island of another cell line showing faint expression of TUBB3 protein (OVCAR-3), in which a significant gain of TUBB3 expression was induced by treatment with PBA but not with 5-Aza-CdR, was hypomethylated, similarly to a cell line showing constitutive expression of TUBB3. We evaluated methylation status in this region in 14 primary tumors using methylationspecific PCR, but there was no significant relationship with TUBB3 immunoreactivity. These findings suggest that aberrant expression of TUBB3 protein might be associated with aggressive behavior of ovarian cancers, and that epigenetic modulation (DNA methylation and chromatin acetylation) might be partly involved in TUBB3 expression.

Our findings indicate that human telomerase reverse transcriptase expression is the rate-limiting determinant of telomerase activity in chorionic villi during the first trimester. Telomerase activity was not detected in placentas with intrauterine growth retardation, whereas human telomerase reverse transcriptase was expressed in some placentas with intrauterine growth retardation.

Aberrant expression of class III ß-tubulin, TUBB3, has been reported to be one of the important mechanisms responsible for taxane resistance in diverse human malignancies. We investigated aberrant TUBB3 expression and its epigenetic modification in 66 primary tumors and 3 cell lines (OVCAR-3, JHOC-5 and JHOC-8) of ovarian cancers. Overexpression of TUBB3 protein was observed in 56 (85%) of the 66 ovarian cancers, and was significantly associated with aggressive tumor behavior (advanced stage, presence of ascites, suboptimal cytoreduction at surgery and presence of lymph node metastasis) (P<0.05). Responses to treatment with a demethylating agent (5-aza-2'-deoxycytidine, 5-Aza-CdR) and a histone deacetylase inhibitor (4-phenylbutyric acid, PBA) differed among the ovarian cancer cell lines. In 2 cell lines with weak expression of TUBB3 protein (OVCAR-3 and JHOC-8), TUBB3 induction was independently induced by treatment with 5-Aza-CdR (JHOC-8) or PBA (OVCAR-3), while neither agent markedly altered TUBB3 mRNA/protein expression in a strongly TUBB3expressing cell line (JHOC-5). A CpG island within intron 1 was hypermethylated in 1 cell line (JHOC-8) that expressed TUBB3 weakly and required 5-Aza-CdR treatment for gene expression. A CpG island of another cell line showing faint expression of TUBB3 protein (OVCAR-3), in which a significant gain of TUBB3 expression was induced by treatment with PBA but not with 5-Aza-CdR, was hypomethylated, similarly to a cell line (JHOC-5) showing constitutive expression of TUBB3. We evaluated methylation status in this region in 14 primary tumors using methylation-specific PCR, but there was no significant relationship with TUBB3 immunoreactivity. These findings suggest that aberrant expression of TUBB3 protein might be associated with aggressive behavior of ovarian cancers, and that epigenetic modulation (DNA methylation and chromatin acetylation) might be partly involved in TUBB3 expression.