[Silencing of Adrm1 by RNA interference suppresses proliferation of colorectal cancer cells].
OBJECTIVE
To investigate the effects of the novel proteasome subunit Adrm1 knockdown by RNA interference on proliferation of colorectal cancer cells.


METHODS
The shRNA eukaryotic expression vector against Adrm1 was constructed and transfected into colon cancer RKO cells. The Adrm1-shRNA stable transfected clones were selected. Experimental cells were divided into 3 groups: the experimental group containing stable Adrm1-shRNA transfected cells, the control group containing only RKO colon cancer cells and stable empty vector transfected control group. The Adrm1 protein expression level was analyzed by Western blot. The colony-forming ability of the three groups was assessed by soft agar assay. The cell proliferation and apoptosis were analyzed by methyl thiazolyl tetrazolium (MTT) method and in situ end labeling (TUNEL) assay. Cell cycle changes were assayed by flow cytometry.


RESULTS
Adrm1-shRNA effectively suppressed Adrm1 expression in the experimental group. Silencing of Adrm1 in RKO cells significantly inhibited their anchorage-independent growth, only occasional individual colonies were formed. The apoptosis rate of experimental group was (12.4 +/- 1.1)%, significantly higher than that of the stable empty vector transfected control group. The proportion of G(0)/G(1) and S/G(2) phase cells in the experimental group was (41.2 +/- 1.1)% and (58.8 +/- 1.1)%, respectively. The cells were arrested at G(1) phase. In addition, Adrm1 RNA interference combined with 5-Fu treatment significantly suppressed colorectal cancer cell growth in vitro.


CONCLUSIONS
Silencing of Adrm1 by RNA interference can significantly suppress proliferation of RKO cells through inducing apoptosis and arresting the cell cycle. The combined application of Adrm1 RNA interference and chemotherapy may become as a novel therapeutic strategy for Adrm1 overexpressed colorectal cancer.
Biomedical Research Center, Sir Run Run Shaw Hospital, Hangzhou 310016, China.
Wei
W
Chen
Xiao-tong
XT
Hu
Qing-lan
QL
Shi
Fu-biao
FB
Zhang
Chao
C
He
D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D017209:Apoptosis; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D019008:Drug Resistance, Neoplasm; D005472:Fluorouracil / Q000494:pharmacology; D005822:Genetic Vectors; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D014162:Transfection
C500781:ADRM1 protein, human; D000964:Antimetabolites, Antineoplastic; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D034741:RNA, Small Interfering; D005472:Fluorouracil