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>

Sorting of CD133(+) subset cells in human gastric cancer and the identification of their tumor initiating cell-like properties / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To sort CD133(+) subset cells in human gastric cancer (GC) and to identify their tumor initiating cell-like properties.</p><p><b>METHODS</b>The tissues of GC and normal tissues adjacent to GC were obtained from 50 patients. Samples were stained for CD133 by immunohistochemistry. Likewise, assessments of CD133 were undertaken by Western blot. Flow cytometry was used to determine the proportion of CD133(+) cells in four GC cell lines therein the KATO-III was sorted by magnetic activated cell sorting (MACS) method. The growing characteristics and the tumorigenic ability of CD133(+) cells were evaluated in vitro and in vivo. Meanwhile, the growth of single cells in suspension culture was observed and expression of stem cell-specific marker were determined using reverse transcription-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>The expression of CD133 was demonstrated on the cell membranes in the mucosa and submucosa of primary GC, which were higher than those in the normal gastric tissues adjacent to cancer (P<0.05). Four GC cell lines including KATO-III, SGC-7901, AGS and MKN-45 were found to contain (28 ± 2)%, (17 ± 2)%, (6 ± 2)%, and (4 ± 2)% of CD133(+) cells respectively. In addition, the purity of CD133(+) cells isolated from KATO-III by MACS was (91 ± 3)% and up to(95 ± 2)% after 1-week culture. CCK-8 detection showed that population doubling time of the CD133(+) cells was (21 ± 3)h, significantly shorter than that of the CD133(-) cells[(40 ± 8)h, P<0.05]. Notably, there was a remarkable difference of tumor formation rate between CD133(+) cells (100%), non-sorted cells (80%), and CD133(-) cells(0). The average mass and volume of tumor in group of CD133(+) cells was larger and heavier than those in non-sorted cells (P<0.05, P<0.05). Furthermore, the single cell proliferated well, formed the big sphere and semi-quantitative RT-PCR showed expression of stem cell markers such as Oct-4, Nanog, Sox-2, Musashi-1 and EGFR.</p><p><b>CONCLUSIONS</b>CD133 protein expression in primary lesions is higher than those in the normal gastric tissues. CD133(+) subset cells can be isolated, purified, and amplified in human GC, and possess some properties including the ability of self-renewal, proliferation, and higher tumorigenic ability in vivo and can express some stem cell markers.</p>