Vitexin suppresses renal cell carcinoma by regulating mTOR pathways

Yuhong Li; Qinghai Sun; Hui Li; Bin Yang; Meng Wang

doi:10.21037/tau-20-1094

Vitexin suppresses renal cell carcinoma by regulating mTOR pathways

Transl Androl Urol. 2020 Aug;9(4):1700-1711. doi: 10.21037/tau-20-1094.

Authors

Yuhong Li¹, Qinghai Sun², Hui Li³, Bin Yang⁴, Meng Wang³

Affiliations

¹ Department of Pharmacy, The First People's Hospital of Jingmen, Jingmen, China.
² Clinical Medicine Discipline, Weifang Traditional Chinese Hospital, Weifang, China.
³ Department of Medicine, Jining No. 1 People's Hospital, Jining, China.
⁴ Department of Vascular Surgery, Jining No. 1 People's Hospital, Jining, China.

Abstract

Background: Renal cell carcinoma (RCC) is one of the most common malignant tumors in the world. Vitexin (apigenin-8-C-D-glucopyranoside), a bioactive compound isolated from a variety of plants, has multiple protective effects on human health. The purpose of this study was to investigate the role of vitexin in RC and the related molecular mechanism.

Methods: Proliferation was tested with Cell Counting Kit-8 and Edu staining. Apoptosis was studied with flow cytometry. Immunofluorescent was applied to show LC3 spots. BALB/c nude mice bearing ACHN cells were established and immunohistochemical staining was applied to validate the in vivo effects of vitexin. All the effects and possible signaling pathways involved were validated with western blotting.

Results: Seventy micromole of vitexin started to show significant effect on the growth of normal renal tubular epithelial cells (HK-2), so 0, 10, 20 and 40 µM of vitexin were used in later experiments. Vitexin inhibited growth and induced apoptosis of ACHN and OS-RC-2 cells in a dose-dependent manner, and promoted excessive autophagy by reducing p62 levels and increasing Beclin1 and LC3II levels. Western blotting revealed that vitexin significantly increased the phosphorylation levels of Adenosine Monophosphate Activated Protein Kinase (AMPK) and c-Jun N-terminal kinase (JNK) in ACHN and OS-RC-2 cells, while decreasing the phosphorylation levels of phosphatidylinositol 3-kinase/activates protein kinase/mammalian target of rapamycin (PI3K/AKT/mTOR). In BALB/c nude mice bearing ACHN cells, vitexin inhibited tumor growth, reduced Ki67 and increased caspase-3 levels in the tumor tissues.

Conclusions: The results indicated that the tumor suppressive role of vitexin in ACHN and OS-RC-2 cells involved AMPK/mTOR, PI3K/AKT/mTOR, and JNK pathways. Therefore, vitexin may be a promising drug for the treatment of RCC.

Keywords: AMPK/mTOR; Renal cell carcinoma (RCC); autophagy; c-Jun N-terminal kinase (JNK); phosphatidylinositol 3-kinase/activates protein kinase/mammalian target of rapamycin (PI3K/AKT/mTOR); vitexin.