The Tumorigenic Effect of Sphingosine Kinase 1 and Its Potential Therapeutic Target.

Sphingosine kinase 1 (SPHK1) regulates cell proliferation and survival by converting sphingosine to the signaling mediator sphingosine 1-phosphate (S1P). SPHK1 is widely overexpressed in most cancers, promoting tumor progression and is associated with clinical prognosis. Numerous studies have explored SPHK1 as a promising target for cancer therapy. However, due to insufficient knowledge of SPHK1 oncogenic mechanisms, its inhibitors' therapeutic potential in preventing and treating cancer still needs further investigation. In this review, we summarized the metabolic balance regulated by the SPHK1/S1P signaling pathway and highlighted the oncogenic mechanisms of SPHK1 via the upregulation of autophagy, proliferation, and survival, migration, angiogenesis and inflammation, and inhibition of apoptosis. Drug candidates targeting SPHK1 were also discussed at the end. This review provides new insights into the oncogenic effect of SPHK1 and sheds light on the future direction for targeting SPHK1 as cancer therapy.

miR-375 affects the proliferation and invasion of hepatoma cells via targetingYAP / 中国肿瘤生物治疗杂志

@# Objective: To investigate the mechanisms of miR-375 affecting the proliferation and invasion of hepatoma cells via targeting YAP (Yes-associated protein). Methods: The cancerous tissues and corresponding para-cancerous tissues of 70 patients with hepatocellular carcinoma (HCC) who underwent surgical resection at the Second Affiliated Hospital of Henan University of Traditional Chinese Medicine from January 2015 to December 2016, as well as the hepatoma cell lines SMMC-7721, Hb611, HepG2 and BEL-7405 were collected for this study. qPCR method was used to detect the expression level of miR-375 in collected HCC tissues and different hepatoma cell lines; Dual luciferase reporter gene assay was used to verify the interaction between miR-375 and YAP; The relationship between miR-375 and clinicopathological features of HCC patients was also analyzed; MTT assay was used to detect the effect of miR375 on the proliferation of hepatoma cells; Transwell invasion assay was used to detect the invasive ability of hepatoma cells after inhibiting the expression of miR-375; Western blotting was used to detect the expression of YAP in HepG2 cells. The nude mouse model of subcutaneously transplanted xenograft was established, and the tumor volume and mass of transplanted hepatoma cells were detected after inhibiting the expression of miR-375. The expression of YAP in xenograft of nude mice was detected by immunohistochemistry and Western blotting. Results: The expression of miR-375 and YAP in HCC tissues was significantly higher than that in para-cancerous tissues (all P<0.05). The expression of miR-375 in HepG2 cells was the highest (P<0.05). miR-375 could specifically bind to the 3' UTR of YAP and regulate the expression activity of YAP. After inhibiting the expression of miR-375, the proliferation and invasion abilities of HepG2 cells were reduced (all P<0.05); The tumor volume and mass of transplanted xenografts were significantly reduced (both P<0.05); The expression of YAP protein in the transplanted xenografts was down-regulated (P<0.05). Conclusion: miR-375 plays an important role in the occurrence and development of liver cancer, and can influence the malignant biological behaviors of hepatoma cells by targeting and regulating the expression ofYAP.