TY - JOUR
T1 - Identification of non-coding RNAs embracing microRNA-143/145 cluster
AU - Iio, Akio
AU - Nakagawa, Yoshihito
AU - Hirata, Ichiro
AU - Naoe, Tomoki
AU - Akao, Yukihiro
N1 - Funding Information:
We thank Dr. Takagi and Dr. Tanigawa (Osaka Medical College Hospital) for supplying clinical samples. This work was supported in part by a grant-in-aid for scientific research (No. 21659104 to A.I.) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.
PY - 2010/6/2
Y1 - 2010/6/2
N2 - In a variety of cancers, altered patterns of microRNA (miRNA) expression are reported and may affect the cell cycle and cell survival. Recent studies suggest that the expression level of miRNAs that act as tumor suppressors is frequently reduced in cancers because of chromosome deletions, epigenetical changes, aberrant transcription and disturbances in miRNA processing. miR-143 and -145, which are located approximately 1.3 kb from each other at chromosome 5q33, are highly expressed in several tissues, but down-regulated in most cancers. However, the mechanism of this down-regulation has not been investigated in detail. Here, we show that both miRNAs were expressed well under the same control program in human tissues, but were down-regulated equally in the most of the cancer cell lines tested. Then we identified the host gene encoding both miRNAs. The transcripts of this gene were approximately 11, 7.5, and 5.5 kb long; and the expression of these transcripts was coordinated with that of its resident miRNAs and down-regulated in the cancer cell lines tested as well as in colorectal cancer tissue samples. These data demonstrate that the host gene can function as a primary miRNA transcript and suggest that the down-regulation of host gene expression caused the low-expression of its encoded microRNAs-143 and -145 in human cancer cell lines and in cancer tissues.
AB - In a variety of cancers, altered patterns of microRNA (miRNA) expression are reported and may affect the cell cycle and cell survival. Recent studies suggest that the expression level of miRNAs that act as tumor suppressors is frequently reduced in cancers because of chromosome deletions, epigenetical changes, aberrant transcription and disturbances in miRNA processing. miR-143 and -145, which are located approximately 1.3 kb from each other at chromosome 5q33, are highly expressed in several tissues, but down-regulated in most cancers. However, the mechanism of this down-regulation has not been investigated in detail. Here, we show that both miRNAs were expressed well under the same control program in human tissues, but were down-regulated equally in the most of the cancer cell lines tested. Then we identified the host gene encoding both miRNAs. The transcripts of this gene were approximately 11, 7.5, and 5.5 kb long; and the expression of these transcripts was coordinated with that of its resident miRNAs and down-regulated in the cancer cell lines tested as well as in colorectal cancer tissue samples. These data demonstrate that the host gene can function as a primary miRNA transcript and suggest that the down-regulation of host gene expression caused the low-expression of its encoded microRNAs-143 and -145 in human cancer cell lines and in cancer tissues.
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U2 - 10.1186/1476-4598-9-136
DO - 10.1186/1476-4598-9-136
M3 - Article
C2 - 20525177
AN - SCOPUS:77954592709
SN - 1476-4598
VL - 9
JO - Molecular Cancer
JF - Molecular Cancer
M1 - 136
ER -
