| miR‐143 is a tumor suppressor miRNA which its downregulation is frequently
reported in colorectal cancer (CRC). This miRNA is a negative regulator of K‐RAS,
c‐MYC, BCL‐2, and MMP‐9 genes which are engaged in tumor growth and metastasis.
In the present study, miR‐143 restoration was performed by transfection of the
pCMV‐miR‐143 vector into the SW‐480 CRC cells. Subsequently, alterations in
proliferative and migratory potential of the cells were investigated by the
3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) and wound‐healing
assays, respectively. Moreover, to detect apoptosis incidence in the transfected cells,
4',6‐diamidino‐2‐phenylindole (DAPI) staining was used. Furthermore, mRNA levels of
c‐MYC, K‐RAS, MMP‐9, and BCL‐2, as potential targets of miR‐143, were assessed by
quantitative Real‐Time PCR (qRT‐PCR). Also the expression levels of c‐MYC, K‐RAS, and
MMP‐9 proteins were investigated by the western blot analysis. Finally, the ratio of BAX to
BCL‐2 expression, as a potential marker of the response to apoptosis stimuli, was
compared between the control and test groups. Furthermore, the trypan blue test was
performed to determine the cell viability in cell suspension. According to the results, a
decreased viability and migratory potential was observed for the miR‐143 receiving cells.
The DAPI staining also confirmed the occurrence of apoptosis. Moreover, BCL‐2, K‐RAS,
MMP‐9, and c‐MYC mRNAs were significantly downregulated in the miR‐143 grafted cells.
The BAX/BCL‐2 ratio also indicated a notable increase in the cells with miR‐143
overexpression. In brief, miR‐143 replacement could be considered as an effective strategy
for the management of CRC and attenuating its invasive features. |