通过构建间充质干细胞（MSC）与乳腺癌细胞间相互作用的共培养模型，探讨MSC对乳腺癌细胞生长的影响。

用含荧光基因第三代自身失活慢病毒载体感染人类脐带分离提取的MSC和乳腺癌细胞MDA-MB-231、MCF-7，以单独培养的乳腺癌细胞MDA-MB-231和MCF-7分别设立对照，2种乳腺癌细胞分别与MSC共培养，检测乳腺癌细胞在MSC作用下增生能力的改变，流式细胞术检测共培养后细胞表面标记物表达。两组间比较采用独立样本t检验，多组间比较采用单因素方差分析，多重比较采用Dunnet-t检验。

MSC在与乳腺癌细胞共培养过程中促进肿瘤细胞生长，第3天共培养组乳腺癌MDA-MB-231细胞数高于单独MDA-MB-231培养组[（5.50±0.71）×10³个比（1.63±0.41）×10³个]，培养至第7天，两组间MDA-MB-231细胞数差异进一步增大[（81.25±7.40）×10³个比（26.25±4.15）× 10³个]，差异具有统计学意义（P均< 0.001）；共培养后MSC促进乳腺癌细胞表达干细胞特有标记物CD90，MCF-7从共培养第2天CD90表达率（1.38±0.30）﹪升高至第9天（92.45±2.04）﹪。在共培养中MSC围绕肿瘤细胞集落方式生长，在形态上变长，并发现一种新型混合细胞（hybrid融合细胞）同时表达绿色和红色荧光，且对化疗药物更敏感。

MSC促进乳腺癌细胞的生长，伴随MSC形态学改变和hybrid融合细胞出现，乳腺癌细胞获得MSC特有CD90表达。

To investigate the effect of MSCs on the growth of breast cancer cells by constructing a co-culture model of the interaction between MSCs and breast cancer cells.

Human umbilical cord was infected with the third generation of sin lentivirus vector containing fluorescent gene, and then MSCs and breast cancer cells MDA-MB-231, MCF-7 were extracted. Breast cancer cells MDA-MB-231 and MCF-7 were cultured respectively, and then control groups were established. Two breast cancer cells were co-cultured with MSCs respectively, to detect the change of proliferation ability of breast cancer cells under the effect of MSCs. Flow cytometry (FACS) was used to detect the expression of cell surface markers. Independent sample t-test was used for comparison between two groups, one-way ANOVA was used for comparison between multiple groups, and Dunnet-t test was used for multiple comparisons.

MSCs promote tumor cell growth during co-culture with breast cancer cells. After 3 days co-cultre, the number of MDA-MB-231 cells in the co-culture group was significantly higher than that in the single MDA-MB-231 culture group (5.50 ± 0.71) × 10³ vs (1.63 ± 0.41) × 10³. The difference became more significantly at 7 days co-culture (81.25 ± 7.40) × 10³ vs (26.25 ± 4.15) × 10³ (P < 0.001) .After co-culture, the expression of stem cell specific marker CD90 could be promoted by MSCs. The expression rate of MCF-7 was only (1.38±0.30) ﹪ at 2 days co-culture and (92.45±2.04) ﹪ at 9 days co-culture. The stem cells grew around the tumor cells and became longer. Meanwhile, a new hybrid cell (hybrid fusion cell) was found, which can simultaneously express green and red fluorescence and was more sensitive to chemotherapeutic drugs.

Human MSCs could promote the growth of breast cancer cells, accompanied by the morphological changes of MSCs and the appearance of hybrid fusion cells. Breast cancer cells could express CD90 and only in MSCs.