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[Abstract ] Objective Difficulties with the preparation of gastric cancer stem cells (CSCs) have been a main obstacle to the studies of gastric cancer .This article addresses the technology of the serum-free medium suspension cultivation of the MKN-45 gastric cancer cell line and screening of stem cells from the cell line based on the biomarkers of gastric CSCs . Methods MKN-45 cells were cultured in serum-free medium for 8 weeks and those in the logarithmic phase cultivated with hoechst 33342 followed by detection of the side cells by flow cytometry .When the side population cells reached 25%, all the cell microspheres were collected , hatched with CD133 and CD44, and subjected to fluorescence-activated cell sorting.The CDl33 +and CD44 +cells were selected as gastric CSCs . Results About 40%of the MKN-45 gastric CSCs were alive , prolif-erated, and formed floating cell balls .Side population cells constitu-ted 3.4% of the MKN-45 cells and 26.9% of the cell balls.The CDl33 +and CD44 +cells made up 11.2% of the MKN-45 cells and 90.3%of the cell balls. Conclusion Cell balls rich in CSCs can be successfully obtained by serum-free medium suspension culti-vation and CSCs can be screened out with hoechst 33342 and surface markers , which may serve as an experimental ground for the stud-ies of gastric CSCs .
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OBJECTIVE: To design and prepare a novel polymeric micelles preparation for hydrophobic salinomycin (SAL), then evaluate the effects of SAL micelles on cancer stem cells in vitro. METHODS: SAL was entrapped into polymeric micelles constructed from amphiphilic diblock copolymer of poly (ethylene glycol)-block-poly (ε-caprolactone) (mPEG-b-PCL). Firstly, the process of preparing micelles and formulation composition were optimized. Then, the physicochemical properties such as particle size distribution, shape and surface morphology, stability and release rates of SAL-loaded micelles were studied. Finally, the side population (SP) cells were analyzed to evaluate the effects of SAL micelles on the MCF-7 cells. RESULTS: The optimal formulation of drug-loaded micelles was mPEG-b-PCL copolymers and SAL (20:1, w/w); the average particle size of SAL-loaded micelles was less than 30 nm, with narrow size distribution, uniform spherical shape and good stability. In vitro studies demonstrated that SAL-loaded micelles were able to decrease the proportion of SP cells. CONCLUSION: Polymeric micelles are capable of overcoming the poor solubility of SAL, and SAL-loaded micelles can selectively deplete breast cancer stem cells.
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Objective To analysis the malignant performance characteristics of tumor stem cell-like side popula-tion cells in patients with cervical cancer. Methods The cervical cancer cells were obtained from surgical resection tumor tissue. The tumor stem cell-like side population cells were isolated by flow cytometry. The cell growth curve was drawn by MTT assay. The invasion ability of tumor cells was compared by transwell assay. The clonogenic capacity was detected by clone formation in soft agar. The expression level of ABCG2 protein, a drug-resistant gene, was detected by immunofluores-cence method. Finally, these cells were transplated into the subcutaneous of de thymus mice. The rate of tumor formation was compared between groups. Results The results from flow cytometry assay showed the percentage of cervical cancer stem cell-like side population cells was 1.39%. Compared with the non-side population cells, the side population cells grow quickly, showed the enhanced invasion ability and colony forming ability. There was more high expression level in ABCG 2 protein of side population cells. The tumor form rate was 100%(10/10) in the side population cells and the non-side popula-tion cells was 20%(2/10). Conclusion The cervical cancer stem cell-like side population cells have more malignant perfor-mance characteristics than that of non-side population cells, which maybe a core target for cancer gene therapy in the future.
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Objective To separate the side population cells(SP) from breast cancer MCF-7 cell line,and observe its biological characteristics.Methods Flow cytometry and Hcechst 33342 dye efflux assay were used to isolate SP cells and non-SP cells from the MCF-7 cell line of human breast cancer.Tumorigenicity of the two subpopulations was observed by a soft agar cloning method.Results The results of FACS analysis indicated that (6.5 ± 0.4 ) ％of the MCF-7 cells were SP cells;The vitro colony formation rate of SP cells was(38.5 ±9.4)％,and higher than that of non-SP cells ( 8.4 ± 2.6 ) ％ ( t =5.34,P ＜ 0,05 ).Concluslon The SP cells sorted from MCF-7 cell line enriched tunor stem cells,which exhibited high tumorigenicity.It indicated that SP cells should play a principal role in breast cancer.
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Objective To study the tumorigenetic characteristics of side population (SP) cells and their exsistence in gastric cancer cell lines and tissues.Methods Flow cytometry and the DNA-binding dye Hoechst 33342 staining were used to analyze sorted SP cells in 3 gastric cancer cell lines(SGC-7901,BCIC-823 and MKN28).SP cells and non-SP cells(main population cells)isolated from SGC-7901 cell line weresubcutaneously injected into 36 nude mice with 500,5000 or 50 000 cells per mouse,respectively.Thetumorigenity was observed 8 weeks after injection.The expression of ATP-binding cassette sub-family Gmember 2(ABcG2)mRNA in three gastric cell lines and its level in gastric cancer tissues were detected by real-time PCR and immunostaining.respectively.Results The proportion of SP cells was accounted for 1.0%in SGC-7901 cells and 1.3%in BGc-823 cells.No SP cell was found in MKN28 cells.As low as 500 SP cells or 50 000 non-SP cells could initiate tumors in mice.The expression of ABcG2 mRNA was higher in SGC-7901(O.162)and BGC-823(O.096)cell lines than that in MKN28 cell line(0.005).The value of AtCG2 mRNA/beta-aetin mRNA and protein in gastric cancer tissues was different from those in gastritis tissues.Condasimm SP cells have strong ability of tumorigenesis compared with non-SP cells.The expression of ABCG2 is found in gastric cancer tissues and part gastritis tissues.The more the SP cells in gastric cell lines,the higher the expression of ABCG2.
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Objective To isolate and identify side population (SP) cells like cancer stem cell from human pancreatic cancer cell line SW1990, for the purpose of further evaluation of their biological characteristics. Methods Cell suspension was stained with Hoechst 33342 and PI. Then SP cells were analyzed in the fluorescence activated cell sorter. Cell growth viability was measured by MTT. Stem cell marker CD133 was determined by flow cytometry. Cloning forming efficiency was determined by cloning plating. Expression of ABCG2 protein was detected by Western blot analysis. Results The proportion of SP cells was 2.7%, however it could be completely blocked by verapamil. 9 days later, the value of A492 of SP cells was 2.1, the cloning forming efficiency was (38.7 ± 6.8) % , the positive rate of CD133 was 69.63%, which were significantly higher than cells 0. 5, ( 15.5 ± 2.8)%, 16.71% of corresponding non-SP( P <0.05). The expression of ABCG2 in SP cells was significantly higher than that in non-SP cells. Conclusions SP cells existed in human pancreatic cancer cells SW1990.
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Background and purpose:The theory of cancer stem cell offers us a new thought about tumors, more and more kinds of cancer stem cell were isolated and indentif ied from corresponding cancer tissue. Our aim was to investigate the content of side population cells in SW480 human colorectal cancer ce11 line and to enrich cancer stem- like cells in SW480 through serum-free medium (SFM) culture. Methods:The percentage of side population cells in human colorectal cancer cell line SW480 was detected with ? ow cytometry. SW480 cell line was cultivated in serum- free medium(SFM) supplemented with growth factors and the cancer stem-like cells reforming into ? oating spheres were isolated. The isolated cancer stem-like cells were identifi ed by limited-dilution assay, differentiation assay, self- renewal assay, and alternative cultivation assay. Results:The percentage of SP cells was 1.2% in SW480,In the absence of serum, a minority (0.54%-0.62%) of cancer stem-like cells in SW480 cells survived, proliferated and formed into the suspended tumor cell spheres. SW480 cancer stem-like cells possessed proliferative, self-renewal and differentiation potential, which were responsible for the ? oating tumor clone. Serum addition into SFM resulted in the proliferation of cancer stem-like cells; after several generations and alternated cultivation in SSM and SFM, cancer stem-like cells maintained their characteristics. Conclusions:SW480 cell line contains a tiny minority of SP cells with stem cell properties.The cancer stem-like cells in SW480 line can be maintained in SFM using a floating culture method.