Fan Cong, Wang Yunshan, Liu Ziming, Sun Ying, Wang Xiuwen, Wei Guangwei, Wei Junmin
Department of Chemotherapy, Cancer Center, Qilu Hospital, Shandong University, Jinan, Shandong 250012, P.R. China.
Department of Human Anatomy and Key Laboratory of Experimental Teratology, Ministry of Education, Shandong University School of Medicine, Jinan, Shandong 250012, P.R. China.
Int J Mol Med. 2015 Jul;36(1):204-14. doi: 10.3892/ijmm.2015.2217. Epub 2015 May 21.
Metformin, a widely prescribed antidiabetic drug, has previously been shown to lower the risk of certain types of cancer, including that of breast cancer, and to improve prognosis. Its anticancer effects, which are mediated by the activation of AMP-activated protein kinase (AMPK), have become notable. The Sonic hedgehog (Shh) signaling pathway is involved in changes in mammary ducts and malignant transformation. The aim of the present study was to elucidate the role of the Shh pathway in mediating the anticancer effects of metformin and the correlation between AMPK and the Shh pathway. We investigated the effectiveness of metformin in inhibiting the proliferation, migration, invasion and stemness of breast cancer cells in vitro using RNA extraction and reverse transcription‑polymerase chain reaction (RT-PCR), western blot analysis, cell proliferation assay, scratch-wound assay (cell migration assay), cell invasion assay, mammosphere culture and flow cytometry. In in vivo experiments, a tumor xenograft model was used to detect the effects of metformin on cancer cell proliferation. The results revealed that the treatment of breast cancer cells with metformin led to the inhibition of the Shh signaling pathway. Importantly, metformin inhibited recombinant human Shh (rhShh)‑induced cell migration, invasion, and stemness, and impaired cell proliferation both in vitro and in vivo. Furthermore, the small interfering RNA (siRNA)‑mediated downregulation of AMPK reversed the inhibitory effects of metformin on rhShh‑induced Gli-1 expression and stemness. Our findings identified a role of the Shh signaling pathway in the anticancer effects of metformin in breast cancer. Furthermore, we revealed that the metformin-mediated inhibition of the Shh signaling pathway may be dependent on AMPK.
二甲双胍是一种广泛使用的抗糖尿病药物，此前已被证明可降低包括乳腺癌在内的某些类型癌症的风险，并改善预后。其通过激活AMP活化蛋白激酶（AMPK）介导的抗癌作用已备受关注。 Sonic hedgehog（Shh）信号通路参与乳腺导管的变化和恶性转化。本研究的目的是阐明Shh通路在介导二甲双胍抗癌作用中的作用以及AMPK与Shh通路之间的相关性。我们使用RNA提取和逆转录-聚合酶链反应（RT-PCR）、蛋白质免疫印迹分析、细胞增殖测定、划痕试验（细胞迁移测定）、细胞侵袭测定、乳腺球培养和流式细胞术，研究了二甲双胍在体外抑制乳腺癌细胞增殖、迁移、侵袭和干性的有效性。在体内实验中，使用肿瘤异种移植模型来检测二甲双胍对癌细胞增殖的影响。结果显示，用二甲双胍处理乳腺癌细胞导致Shh信号通路受到抑制。重要的是，二甲双胍在体外和体内均抑制重组人Shh（rhShh）诱导的细胞迁移、侵袭和干性，并损害细胞增殖。此外，小干扰RNA（siRNA）介导的AMPK下调逆转了二甲双胍对rhShh诱导的Gli-1表达和干性的抑制作用。我们的研究结果确定了Shh信号通路在二甲双胍对乳腺癌的抗癌作用中的作用。此外，我们揭示了二甲双胍介导的对Shh信号通路的抑制可能依赖于AMPK。
