Joo Moon Kyung, Park Jong-Jae, Kim Sung Ho, Yoo Hyo Soon, Lee Beom Jae, Chun Hoon Jai, Lee Sang Woo, Bak Young-Tae
Division of Gastroenterology, Department of Internal Medicine, Korea University College of Medicine, Guro Hospital, Seoul 152‑703, Republic of Korea.
Division of Gastroenterology, Department of Internal Medicine, Korea University College of Medicine, Anam Hospital, Seoul 136‑705, Republic of Korea.
Int J Oncol. 2015;46(6):2380-8. doi: 10.3892/ijo.2015.2935. Epub 2015 Mar 26.
A recent study reported that plumbagin downregulated the activity of Janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) pathway to show various antitumor effects in multiple myeloma cells. We aimed in this in vitro study to demonstrate the inhibition of JAK2/STAT3 pathway by plumbagin through inducing SH2-containing protein tyrosine phosphatase 1 (SHP1) expression in the MKN-28 gastric cancer cell line. We performed western blot analysis to measure SHP1, phosphor-JAK2/STAT3 level, and observed that plumbagin induced SHP1 expression and simultaneously downregulated phosphor-JAK2/STAT3 in MKN-28 cells, with negative SHP1 expression. This effect was consistent when JAK2/STAT3 signaling was activated by interleukin-6 (IL-6), and ameliorated when cells were treated with prevanadate, a protein tyrosin phosphatase inhibitor. Furthermore, plumbagin significantly reduced gene expression of cyclin D1, vascular endothelial growth factor (VEGF)-1, Bcl-xL, survivin and matrix metalloproteinase-9 (MMP-9), known target products of STAT3 activation in gastric carcinogenesis by reverse transcription-polymerase chain reaction (RT-PCR). Several functional studies such as water soluble tetrazolium salt-1 (WST-1) assay, wound closure assay, Matrigel invasion assay and Annexin V assay were also performed, and we validated the functional effect of plumbagin for inhibition of cell proliferation, migration and invasion, and induction of apoptosis. Collectively, our findings suggest that plumbagin is a potential regulator of cellular growth, migration, invasion and apoptosis by inhibiting both constitutive and inducible STAT3 activity through induction of SHP1 in gastric cancer cells.
最近一项研究报道，白花丹醌可下调Janus激酶2（JAK2）-信号转导子和转录激活子3（STAT3）通路的活性，从而在多发性骨髓瘤细胞中表现出多种抗肿瘤作用。在这项体外研究中，我们旨在证明白花丹醌通过诱导MKN-28胃癌细胞系中含SH2结构域的蛋白酪氨酸磷酸酶1（SHP1）的表达来抑制JAK2/STAT3通路。我们进行了蛋白质印迹分析以检测SHP1、磷酸化JAK2/STAT3水平，并观察到白花丹醌在MKN-28细胞中诱导SHP1表达，同时下调磷酸化JAK2/STAT3，而SHP1表达呈阴性。当JAK2/STAT3信号被白细胞介素-6（IL-6）激活时，这种效应是一致的，而当细胞用蛋白酪氨酸磷酸酶抑制剂原钒酸钠处理时，这种效应得到改善。此外，通过逆转录-聚合酶链反应（RT-PCR），白花丹醌显著降低了细胞周期蛋白D1、血管内皮生长因子（VEGF）-1、Bcl-xL、生存素和基质金属蛋白酶-9（MMP-9）的基因表达，这些都是胃癌发生过程中STAT3激活的已知靶标产物。我们还进行了多项功能研究，如水溶性四氮唑盐-1（WST-1）检测、伤口愈合检测、基质胶侵袭检测和膜联蛋白V检测，并验证了白花丹醌对细胞增殖、迁移和侵袭的抑制作用以及对细胞凋亡的诱导作用。总的来说，我们的研究结果表明，白花丹醌可能是一种潜在的细胞生长、迁移、侵袭和凋亡的调节剂，它通过在胃癌细胞中诱导SHP1来抑制组成型和诱导型STAT3活性。
