乳腺癌微环境中脂肪细胞可通过瘦素促进乳腺癌MDA-MB-231细胞的增殖与迁移

Adipocytes in Breast Cancer Microenvironment Can Promote the Proliferation and Migration of Breast Cancer Cells MDA-MB-231 by Leptin

为研究乳腺癌微环境中前脂肪细胞和成熟脂肪细胞对乳腺癌MDA-MB-231细胞增殖和迁移能力的影响,该研究将前脂肪细胞3T3-L1诱导为成熟脂肪细胞,再将前脂肪细胞和成熟脂肪细胞分别与乳腺癌MDA-MB-231细胞共培养,通过显微镜成像、油红O染色实验、MTT实验、Transwell实验分别观察肿瘤细胞形态、增殖及迁移能力的改变。Western blot和ELISA检测前脂肪细胞和成熟脂肪细胞瘦素(leptin)的表达水平。细胞免疫荧光法和Western blot分别检测肿瘤细胞中瘦素受体(leptin recepter,Ob-R)、瘦素信号通路关键分子及下游靶因子的表达水平变化。结果显示,共培养后,肿瘤细胞形态变得更加纤长,增殖能力增加(P<0.05),穿过小室的细胞数明显增多(P<0.05)。在成熟脂肪细胞共培养组的肿瘤细胞中还出现了明显的脂质累积。Western blot和ELISA检测发现,前脂肪细胞和成熟脂肪细胞均有瘦素的表达。与空白对照组相比,两个共培养组中肿瘤细胞的p-Akt、p-STAT3、cyclin D1和MMP9蛋白质水平均明显上调(P<0.05),而p-ERK1/2仅在前脂肪细胞共培养组中上调(P<0.001),在成熟脂肪细胞共培养组中没有明显变化。和共培养组相比,瘦素中和抗体处理后可以抑制肿瘤细胞中瘦素下游信号通路的激活。该研究表明,前脂肪细胞和成熟脂肪细胞均能促进乳腺癌MDA-MB-231细胞的增殖和迁移,且这一促进作用和瘦素信号通路有关。

To investigate the effect of pre-adipocytes and adipocytes on the proliferation and migration of breast cancer cells MDA-MB-231, we set up a transwell system. Pre-adipocytes or adipocytes were co-cultured with MDA-MB-231 cells in this system. As for MDA-MB-231 cells in different groups, morphological changes were observed by microscope, lipids accumulation were stained by Oil red O, the ability of poliferation was detected by MTT assay, and the ability of migration was estimated by Transwell assay. Western blot and ELISA assay were used to detect the expression of leptin in pre-adipocytes and adipocytes. Immunofluorescence staining was used toidentified the expression of leptin recepter（Ob-R） in MDA-MB-231 cells. The key molecules of leptin signaling pathway in MDA-MB-231 cells were detected by Western blot. The expression levels of key molecules in leptin signaling pathway after using leptin netralization were detected by Western blot. The results showed that compared with control group, MDA-MB-231 cells in the two co-culture groups became more spindly, the proliferation and migration ability of them were significantly enhanced（P〈0.05）. And lipids accumulation in MDA-MB-231 cells in adipocytes group can be observed. The levels of leptin could be detected in pre-adipocytes and adipocytes and their medium. Compared with control group, the expression of p-Akt, p-STAT3, cyclin D1 and MMP9 in MDA-MB-231 cells increased in the two co-cultre groups（P〈0.05）. But the expression of p-ERK in MDA-MB-231 cells only increased in pre-adipocytes group（P〈0.001）. Compared with co-culture groups, the expression of key molecules in leptin signaling decreased after treatment with leptin netralization. Our results suggested that either pre-adipocytes or adipocytes could promote the proliferation and migration of breast cancer cells MDA-MB-231, and leptin signaling pathway might be involved in this process.