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Colorectal cancer (CRC) is one of the most common malignant tumours, with multiple driving factors and biological transitions involved in its development. Claudin-2 (CLDN2), a well-defined component of cellular tight junction, has been indicated to associate with CRC progression. However, the function of CLDN2 and the underlying mechanism whereby the downstream signalling transduction is regulated in CRC remains largely unclear. In this study, we demonstrated that CLDN2 is upregulated in CRC samples and associated with poor survival. And CLDN2 depletion significantly promotesN-myc downstreamregulated gene 1 (NDRG1) transcription, leading to termination of the CRC growth and metastasis in vitro and in vivo. Mechanistically, this process promotes CLDN2/ZO1/ZONAB complex dissociation and ZONAB shuttle into nucleus to enrich in the promoter of NDRG1. Thus, this study reveals a novel CLDN2/ZO1/ZONAB-NDRG1 axis in CRC by regulating the expression of EMTrelated genes and CDKIs, suggesting CLDN2 may serve as a promising target for CRC treatment. [ABSTRACT FROM AUTHOR]

Heterotrimeric G proteins, which are composed of Gα and Gβγ subunits, transduce signals sensed by the coupled surface receptors. Aberrant expressions of G proteins have been observed in many cancer types. This study aimed to determine the expression level of the stimulatoryGprotein alpha S subunit (Gαs, the main transcript encoded by the GNAS locus) and its biological function in renal cell carcinoma (RCC). Western blotting and quantitative reverse transcription-PCR results show that Gαs expression dramatically increased in RCC cell lines (ACHN, GRC-1, and 786-O) compared to normal renal epithelial cells HK-2. Knockdown of Gαs by small interferingRNA (siRNA) caused a significant inhibition on proliferation of ACHN cells as indicated by MTT assay and colony formation assay. Overexpression of Gαs in HK-2 cells promoted cell proliferation and led to a higher level of intracellular cyclic adenosine monophosphate (cAMP) in response to parathyroid hormone (PTH) compared to the cells transfected with empty vector. Notably, the growth of HK-2 cells overexpressing Gαs was efficiently inhibited in the presence of protein kinase A (PKA) inhibitor H89. Furthermore, in a xenograft model by subcutaneous injection of ACHN cells, tumor growth was also suppressed by H89. Taken together, these results suggest that Gαs plays a tumor-promoting role in RCC and possibly acts through a PKA-dependent pathway. Our findings may provide new clues for target therapy for RCC in the future. [ABSTRACT FROM AUTHOR]

Purpose: To elucidate the effect of IFN-α treatment on tumor growth and metastasis of hepatocellular carcinoma (HCC). Methods: IFN-α administration was conducted in nude mice using an orthotopic implantation model of human HCC, and the key molecular markers in the IFN-α treatment was detected by immunohistochemistry staining and PCR array. Results: Up to 12 weeks of IFN-α treatment significantly suppressed tumor growth of HCC, but relatively increased the number of circulating tumor cells, which might be due to the enhanced tumor hypoxia as well as up-regulation of metastasis-related genes, such as HIF-1α, c-met, u-PA, PDGF-A, and IL-8. However, IFN-α had no direct effect on migration and invasion of HCC cells. Conclusions: IFN-α has janus face of consistently suppressing HCC growth, however, promoting tumor metastasis capacity, which is of clinical indication for the scientific administration of IFN-α and the similar antiangiogenesis drugs for their dual effect on tumor growth and metastasis. [ABSTRACT FROM AUTHOR]

Translational regulation is one of the decisive steps in gene expression, and its dysregulation is closely related to tumorigenesis. Eukaryotic translation initiation factor 3 subunit i (eIF3i) promotes tumor growth by selectively regulating gene translation, but the underlying mechanisms are largely unknown. Here, we show that eIF3i is significantly increased in colorectal cancer (CRC) and reinforces the proliferation of CRC cells. Using ribosome profiling and proteomics analysis, several genes regulated by eIF3i at the translation level were identified, including D-3-phosphoglycerate dehydrogenase (PHGDH), a rate-limiting enzyme in the de novo serine synthesis pathway that participates in metabolic reprogramming of tumor cells. PHGDH knockdown significantly represses CRC cell proliferation and partially attenuates the excessive growth induced by eIF3i overexpression. Mechanistically, METTL3- mediated N6-methyladenosine modification on PHGDH mRNA promotes its binding with eIF3i, ultimately leading to a higher translational rate. In addition, knocking down eIF3i and PHGDH impedes tumor growth in vivo. Collectively, this study not only uncovered a novel regulatory mechanism for PHGDH translation but also demonstrated that eIF3i is a critical metabolic regulator in human cancer. [ABSTRACT FROM AUTHOR]

Human lactoferrin (hLF) is a multifunctional glycoprotein that can inhibit cancer growth. The molecular mechanism of hLF-induced tumor growth inhibition is incompletely understood. Moreover, the adenovirus vector-mediated hLF (Ad-hLF) gene therapy on cervical cancer has not been yet characterized. In this study, the replication-deficient Ad-hLF was used to explore tumor growth suppression effects on cervical cancer in vitroand in vivo.The results showed that the recombinant adenovirus encoding hLF delivery resulted in a more differential tumor growth inhibition, and this growth arrest was caused by cell cycle inhibition at G2/M phase. In addition, Fas, a death-inducing receptor, and Bax, a member of pro-apoptotic Bcl-2 family, were increased in the sample of cervical cancer tissue treated by Ad-hLF. Further, it was also observed that caspase-3 was activated and the expression of anti-apoptotic Bcl-2 was decreased. These results indicated that the growth inhibitory effects of Ad-hLF on cervical cancer were caused by elevated expression of Fas and decreased the ratio of anti- to pro-apoptotic molecule Bcl-2/Bax. [ABSTRACT FROM AUTHOR]