Influence of CD133

Objective: To investigate the influence of CD133

Effect of RNA interference inhibition to expression of CD133 on tumor cell biological characteristics in KATO-III CD133(+) cells of human gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the changes in proliferation, invasiveness, clone sphere formation and chemosensitivity of human gastric cancer cell lines of KATO-III CD133(+) cells transfected with small interfering RNA (siRNA) against CD133 gene.</p><p><b>METHODS</b>CD133(+) cells of KATO-III cell lines were isolated by magnetic activated cell sorting (MACS). CD133 siRNA was designed and synthesized, and then transfected into KATO-III CD133(+) cells. Cell fluorescence counting under confocal laser scanning microscope was used to determine the transfection efficiency after transfection with the CD133 FITC-siRNA. The knock-down effect of the CD133 gene and expression of epithelial-mesenchymal transition (EMT)-related factors were detected by RT-PCR and Western blotting. Cell counting kit-8 assay (CCK-8), transwell chamber and colony sphere forming assay were performed to measure the variation of cell proliferative, invasive, colony formation viability and chemosensitivity to 5-FU after the above-mentioned treatment.</p><p><b>RESULTS</b>The transfection efficiency was (87.7±8.1)%. The CD133 mRNA and protein expression levels in the interference group were lower than those in negative control group. Twenty-four, 48 and 72 hours after transfection, cells proliferation activity was significantly inhibited in the interference group compared with negative control group, (all P<0.01). Seventy-two hours after transfection, compared with negative control group, cells proliferation activity was reduced by (52.1±8.0)%. The invasive cell number reduced (41.7±6.0 vs. 130.3±11.0, P<0.05) and clone formation rate decreased significantly [(24.3±4.3)% vs. (45.1±6.4)%, P<0.01] in the interference group. EMT-related gene E-cadherin protein expression increased, while the Snail and N-cadherin protein expression reduced in the interference group (all P<0.01). The cells sensitivity to 5-FU was significantly enhanced in the interference group, and the cell inhibition rate of 5-Fu was (62.4±3.3)%, higher than that in negative control group [(21.5±2.2)%, P<0.01].</p><p><b>CONCLUSIONS</b>The expression of CD133 gene plays an important role in cell proliferation, invasiveness, colony formation and resistance to chemotherapy of KATO-III CD133(+) gastric cancer cells. It suggests that CD133 can be used as one of surface markers for detection of gastric cancer stem cells. Inhibition of CD133 expression may be a promising way for gastric cancer biotherapy.</p>

CD133 promotes the invasion and metastasis of gastric cancer via epithelial-mesenchymal transition / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To examine the association between CD133 expression and invasion of gastric cancer, and to elucidate whether CD133 can promote the invasion and metastasis of gastric cancer via epithelial-mesenchymal transition (EMT).</p><p><b>METHODS</b>The CD133(+) and CD133(-) KATO-III( cells were sorted by magnetic activated cell sorting (MACS). The invasion ability was detected by Transwell method. RT-PCR and Western blot were used to detect the expression of EMT-related factors in KATO-III( cells before and after CD133 was knocked out by siRNA method. The expressions of CD133 and EMT-related proteins of cancer and adjacent normal tissues in 50 patients with gastric cancer were detected by Western blot, and correlations among protein expressions were also analyzed.</p><p><b>RESULTS</b>As compared to CD133(-) cells, the number of broken-membrane cells was significantly higher (67.7±10.5 vs. 13.3±6.8, P=0.001) and the invasion ability was stronger (P<0.05) in CD133(+) cells, while the mRNA expression levels of Snail and N-cadherin were significantly higher in CD133(+) cells (0.311±0.015 vs. 0.223±0.016, P=0.040; 0.581±0.020 vs. 0.270±0.018,P=0.004), and the protein expression levels of Snail and N-cadherin were significantly higher in CD133(+) cells as well (0.513±0.015 vs. 0.179±0.023, P=0.030; 0.538±0.028 vs. 0.202±0.032, P=0.020), but E-cadherin mRNA and protein levels were significantly lower in CD133(+) cells (0.231±0.009 vs. 0.460±0.015, P=0.040; 0.426±0.030 vs. 0.748±0.027, P=0.040). After CD133 knock-out, the expressions of Snail and N-cadherin were down-regulated (P<0.05) and the expression of E-cadherin was up-regulated (P<0.05). As compared to normal mucosal tissues, the protein expression levels of Snail, N-cadherin and CD133 in gastric cancer tissues were significantly higher(0.635±0.119 vs. 0.485±0.116, P=0.029; 0.599±0.114 vs. 0.259±0.108, P=0.020; 0.754±0.154 vs. 0.329±0.134, P=0.001), while the protein expression of E-cadherin in gastric cancer tissues was lower (0.378±0.123 vs. 0.752±0.156, P=0.003). The protein expressions of Snail and N-cadherin were positively correlated with CD133 expression (r=0.278, P=0.048; r=0.406, P=0.003) and the protein expression of E-cadherin was negatively correlated with CD133 expression (r=-0.504, P=0.000).</p><p><b>CONCLUSION</b>CD133(+) cells in primary lesion of gastric cancer have relatively higher invasion ability, which may promote the metastasis of gastric cancer via up-regulation of EMT-related factors.</p>