Silencing RAB27a inhibits proliferation, invasion and adhesion of triple-negative breast cancer cells / 南方医科大学学报

OBJECTIVE@#To investigate the effect of inhibition of RAB27 protein family, which plays a pivotal role in exosome secretion, on biological behaviors of triple-negative breast cancer cells.@*METHODS@#Quantitative real-time PCR and Western blotting were used to examine the expressions of RAB27 family and exosome secretion in 3 triple-negative breast cancer cell lines (MDA-MB-231, MDA-MB-468, and Hs578T) and a normal breast epithelial cell line (MCF10A). The effect of small interfering RNA (siRNA)-mediated silencing of RAB27a and RAB27b on exosome secretion in the 3 breast cancer cell lines was detected using Western blotting, and the changes in cell proliferation, invasion and adhesion were evaluated.@*RESULTS@#Compared with normal breast epithelial cells, the 3 triple-negative breast cancer cell lines exhibited more active exosome secretion (P < 0.001) and showed significantly higher expressions of RAB27a and RAB27b at both the mRNA and protein levels (P < 0.01). Silencing of RAB27a in the breast cancer cells significantly down-regulated exosome secretion (P < 0.001), while silencing of RAB27b did not significantly affect exosome secretion. The 3 breast cancer cell lines with RAB27a silencing-induced down-regulation of exosome secretion showed obvious inhibition of proliferation, invasion and adhesion (P < 0.01) as compared with the cell lines with RAB27b silencing.@*CONCLUSION@#RAB27a plays central role in the exosome secretion in triple-negative breast cancer cells, and inhibiting RAB27a can inhibit the proliferation, invasion and adhesion of the cells.

The relationship between lumbar disc degeneration of lumbar spinal stenosis and the dural sac cross-sec-tional area by MRI measurement / 实用医学杂志

Objective To explore the relationship between lumbar disc degeneration (LDD) of lumbar spinal stenosis(LSS)and the dural sac cross-sectional area(DSCA)by MRI measurement. Methods 91 patients with central degenerative LSS were randomly selected and 91 age-and sex-matched people without LSS were select-ed as a control group. LDD was classified into five grades by MRI detection according to the method proposed by Pfirrmann and DSCA were measured. Results LDD was not associated with age in LSS. The proportion of severe degenerated disc in lower lumbar levels were higher than that of L2/3 in the two groups;DSCA in severe degenerat-ed disc group was significantly smaller than that in light degenerated group only in L2/3 and L3/4 in LSS. There were no statistical differences in every lumbar level in the control group. Conclusions LDD in L4/5 and L5/S1 of LSS is more severe than that of the normal people. DSCA and LDD are positively correlated in L2/3 and L3/4,but not in L4/5 and L5/S1 for LSS.