Nitrogen Permease Regulator-Like-2 Exhibited Anti-Tumor Effects And Enhanced The Sensitivity Of Colorectal Cancer Cells To Oxaliplatin And 5-Fluorouracil

NPRL2 down-regulation facilitates the growth of hepatocellular carcinoma via the mTOR pathway and autophagy suppression

Hepatocellular carcinoma (HCC) is a highly invasive malignancy. Recently, GATOR1 (Gap Activity TOward Rags 1) complexes have been shown to play an important role in regulating tumor growth. NPRL2 is a critical component of the GATOR1 complex. Therefore, this study used NPRL2 knockdown to investigate how GATORC1 regulates the prognosis and development of HCC via the mammalian target of rapamycin (mTOR) and autophagy signaling pathways. We established HepG2 cells with NPRL2 knockdown using small interfering RNA (siRNA) and short hairpin RNA (shRNA) systems. The siRNA-mediated and shRNA-mediated NPRL2 down-regulation significantly reduced the expression of NPRL2 and two other GATPOR1 complex components, NPRL3 and DEPDC5, in HepG2 cells; furthermore, the efficient down-regulation of NPRL2 protein expression by both the shRNA and siRNA systems enhanced the proliferation, migration, and colony formation in vitro. Additionally, the NPRL2 down-regulation significantly increased HCC growth in the subcutaneous and orthotopic xenograft mouse models. The NPRL2 down-regulation increased the Rag GTPases and mTOR activation and inhibited autophagy in vitro and in vivo. Moreover, the NPRL2 level in the tumors was significantly associated with mortality, recurrence, the serum alpha fetoprotein level, the tumor size, the American Joint Committee on Cancer stage, and the Barcelona Clinic Liver Cancer stage. Low NPRL2, NPRL3, DEPDC5, and LC3, and high p62 and mTOR protein expression in the tumors was significantly associated with disease-free survival and overall survival in 300 patients with HCC after surgical resection. Conclusion: The efficient down-regulation of NPRL2 significantly increased HCC proliferation, migration, and colony formation in vitro, and increased HCC growth in vivo. Low NPRL2 protein expression in the tumors was closely correlated with poorer clinical outcomes in patients with HCC. These results provide a mechanistic understanding of HCC and aid the development of treatments for HCC.

SEA and GATOR 10 Years Later

The SEA complex was described for the first time in yeast Saccharomyces cerevisiae ten years ago, and its human homologue GATOR complex two years later. During the past decade, many advances on the SEA/GATOR biology in different organisms have been made that allowed its role as an essential upstream regulator of the mTORC1 pathway to be defined. In this review, we describe these advances in relation to the identification of multiple functions of the SEA/GATOR complex in nutrient response and beyond and highlight the consequence of GATOR mutations in cancer and neurodegenerative diseases.

Improving anti-tumor outcomes for colorectal cancer therapy through in situ thermosensitive gel loading harmine

Colorectal cancer is a common malignant tumor that seriously endangers human health. Harmine (HM), a natural product, has been shown to have a significant inhibitory effect on various cancers. However, systemic injection of HM can cause central nervous toxicity, which limits its clinical application. Local administration of HM overcomes this problem to a certain extent. In this study, we prepared an in situ thermosensitive HM gel preparation (HM gel), and used it to treat colon cancer with reduced toxic side effects and prolonged residence time of HM at the tumor site. We employed a central composite design and response surface methodology to optimize the formulation, and evaluated the physicochemical properties, rectal retention capacity, and in vitro and in vivo antitumor effects of HM gel on colon 26 tumor cells. The results showed that HM gel had a significant inhibitory effect on the growth of colon 26 cells in vitro. In an orthotopic tumor-bearing mouse model, HM gel exhibited an obvious inhibitory effect on tumor growth and metastasis, and significantly prolonged the survival period. In conclusion, HM gel exhibited significant anti-tumor effects on colon cancer, and therefore presents a promising formulation for the treatment of colorectal cancer.