Yu Liang, Li Ting, Zhang Heng, Ma Zhenhua, Wu Shengli
Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi'an Jiaotong University Xi'an 710061, Shaanxi, P. R. China.
Tumor Diagnosis and Treatment Center, Yulin First Hospital Yulin 719000, Shaanxi, P. R. China.
Am J Transl Res. 2023 Jul 15;15(7):4521-4532. eCollection 2023.
Hypoxia is a significant feature of many solid tumors and can activate hypoxia-inducible factor 1α (HIF-1α)/vascular epidermal growth factor (VEGF) signaling pathway, which is closely related to the occurrence and development of primary liver cancer (PLC). Silymarin (SM) had been used as a traditional liver protective drug for decades. Recent studies have found that SM has chemopreventive and chemosensitizing effects on multiple cancers. In this study, we investigated the effects of SM on HIF-1α/VEGF signaling in human hepatocellular carcinoma cells under hypoxia conditions.
HepG2 and Hep3B cells were divided into different experimental groups according to different culture conditions (aerobic or anaerobic) and the concentration of SM in the culture medium. The cellular proliferation, migration, invasion, colony formation, and apoptosis were observed by using methyl thiazolyl tetrazolium (MTT) assay, cell migration assay, invasion assay, soft agar colony formation assay, and Annexin V apoptosis assay, respectively. The cellular expressions of HIF-1α and VEGF were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) and western blot (WB) analyses.
SM reduced cellular proliferation, migration, invasion, and colony formation, but induced apoptosis in HepG2 and Hep3B cells under hypoxia conditions. The half inhibitory concentrations (IC) of SM on HepG2 and Hep3B cells were 58.46 and 75.13 umol/L, respectively. SM also suppressed cellular expressions of HIF-1α and VEGF in HepG2 and Hep3B cells under hypoxia conditions at the mRNA and protein levels. All these effects of SM were dose dependent.
The inhibitory effect of SM on HepG2 and Hep3B cells under hypoxia is partially via downregulating HIF-1α/VEGF signaling, which may serve as a potential drug therapy target for liver cancer based on SM.
缺氧是许多实体瘤的一个显著特征，可激活缺氧诱导因子1α（HIF-1α）/血管内皮生长因子（VEGF）信号通路，这与原发性肝癌（PLC）的发生发展密切相关。水飞蓟素（SM）作为一种传统的肝脏保护药物已使用数十年。最近的研究发现，SM对多种癌症具有化学预防和化学增敏作用。在本研究中，我们研究了SM在缺氧条件下对人肝癌细胞中HIF-1α/VEGF信号的影响。
根据不同的培养条件（有氧或无氧）和培养基中SM的浓度，将HepG2和Hep3B细胞分为不同的实验组。分别采用甲基噻唑基四氮唑（MTT）法、细胞迁移试验、侵袭试验、软琼脂集落形成试验和膜联蛋白V凋亡试验观察细胞增殖、迁移、侵袭、集落形成和凋亡情况。通过实时逆转录-聚合酶链反应（RT-PCR）和蛋白质免疫印迹（WB）分析测定HIF-1α和VEGF的细胞表达。
在缺氧条件下，SM可降低HepG2和Hep3B细胞的增殖、迁移、侵袭和集落形成，但诱导细胞凋亡。SM对HepG2和Hep3B细胞的半数抑制浓度（IC）分别为58.46和75.13 μmol/L。在缺氧条件下，SM还在mRNA和蛋白质水平上抑制HepG2和Hep3B细胞中HIF-1α和VEGF的细胞表达。SM的所有这些作用均呈剂量依赖性。
SM在缺氧条件下对HepG2和Hep3B细胞的抑制作用部分是通过下调HIF-1α/VEGF信号通路实现的，这可能使SM成为一种潜在的肝癌药物治疗靶点。
