MicroRNA expression signature profile and its clinical significance in endometrioid carcinoma

Abstract

To determine the microRNA (miRNA) expression signature and its clinical significance in endometrioid carcinoma (EC). The miRNA profiles were analyzed by miRNA microarray in 73 cases of EC. The expression level of the eight selected miRNAs were measured by real-time fluorescent quatitative PCR(qRT-PCR). Immunohistochemistry (IHC) was performed to assess the status of PTEN, a potential target of the selected miRNAs. (1) Using TaqMan low-density arrays, 47 miRNAs that differed between EC and normal controls were identified, including 26 down-regulated and 21 up-regulated miRNAs. (2) To confirm the miRNA expression pattern in typeIEC, the expression levels of the eight selected miRNAs were evaluated in a new set of 58 cases of typeIEC by individual miRNA qRT-PCR assays. Three miRNAs (miR-141, miR-200a, miR-205) were up-regulated and two miRNAs (miR-143, miR-145) were down-regulated. These were significantly differentially expressed in typeIEC and normal controls (P < 0.05), whereas such difference was not present in type II tumors compared to normal controls. (3) In typeIEC, loss of PTEN was more frequent in the miR-141 or miR-200a up-regulated subgroups, and the correlation between the PTEN and miR-200a status in typeItumors was statistically significant (P < 0.05). EC may have a unique miRNA expression profile. The expression levels of the five miRNAs (miR-141, miR-200a, miR-205, miR-143, miR-145) are significantly deregulated in typeIEC compared to normal control but not in typeIItumors. The findings suggest that the miRNAs related to type Iand typeIIEC might be different. PTEN might be a potential target of miR-141 and miR-200a in endometrial carcinogenesis.