State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
Department of Clinical Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Life Sci. 2014 Mar 18;99(1-2):37-43. doi: 10.1016/j.lfs.2014.01.067. Epub 2014 Feb 7.
We have previously reported that elevated expression of sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase 2 (SERCA2) was related to the malignant degree of different types of human liposarcoma. Here, we investigated the effects of high SERCA2b expression on proliferation and differentiation of preadipocyte-like human liposarcoma cell line SW872 cells.
SW872 cells were stably transfected with human SERCA2b expressing plasmid. Adipocyte differentiation was assayed by adipogenic gene and protein expression. Cell proliferation, formation of reactive oxygen species (ROS) and phosphorylation of peroxisome proliferator activated receptor gamma (PPAR-γ) and extracellular signal-regulated kinase (ERK) were determined by MTT assay, 2, 7-dichlorofluorescein diacetate (DCF-DA) assay and western blot analysis, respectively.
High expression of SERCA2b promoted cell proliferation and blocked the differentiation potential of SW872 cells under both in vitro and in vivo differentiation-inducing environment. Moreover, high expression of SERCA2b induced accumulation of ROS and enhanced ERK signaling, thus leading to inactivation of PPAR-γ and down-regulation of adipocyte-specific genes.
The results revealed a novel role of SERCA2b in facilitating the blockade of human liposarcoma differentiation, which helps provide a molecular target for therapeutic interventions of human liposarcoma.
我们之前的研究报道，肌浆内质网 Ca(2+) -ATP 酶 2（SERCA2）的高表达与不同类型人脂肪肉瘤的恶性程度有关。在此，我们研究了高表达 SERCA2b 对人脂肪肉瘤前体细胞系 SW872 细胞增殖和分化的影响。
通过稳定转染人 SERCA2b 表达质粒，使 SW872 细胞高表达 SERCA2b。通过脂肪生成基因和蛋白表达来检测脂肪细胞分化。通过 MTT 检测、2,7-二氯二氢荧光素二乙酸酯（DCF-DA）检测和 Western blot 分析分别测定细胞增殖、活性氧（ROS）形成、过氧化物酶体增殖物激活受体 γ（PPAR-γ）和细胞外信号调节激酶（ERK）磷酸化。
SERCA2b 的高表达促进了 SW872 细胞在体外和体内诱导分化环境下的增殖，并阻断了其分化潜能。此外，SERCA2b 的高表达诱导了 ROS 的积累，并增强了 ERK 信号通路，从而导致 PPAR-γ失活和脂肪细胞特异性基因下调。
这些结果揭示了 SERCA2b 在促进人脂肪肉瘤分化阻滞中的新作用，有助于为人类脂肪肉瘤的治疗干预提供分子靶点。
