Purpose: NOTCH signaling pathway is essential in T-cell development and NOTCH1 mutations are frequently present inT-cell acute lymphoblastic leukemia (T-ALL). To gain insight into its clinical significance, NOTCH1 mutation was investigated in 77 patients withT-ALL. Experimental Design: Detection of NOTCH1 mutation was done using reverse transcription-PCR amplification and direct sequencing, and thereby compared according to the clinical/ biological data of the patients. Results: Thirty-two mutations were identified in 29 patients (with dual mutations in 3 cases), involving not only the heterodimerization and proline/glutamic acid/serine/threonine domains as previously reported but also the transcription activation and ankyrin repeat domains revealed for the first time. These mutations were significantly associated with elevated WBC count at diagnosis and independently linked to short survival time. Interestingly, the statistically significant difference of survival according to NOTCH1 mutations was only observed in adult patients (>18 years) but not in pediatric patients (V18 years), possibly due to the relatively good overall response of childhoodT-ALL to the current chemotherapy. NOTCH1 mutations could coexist with HOX11, HOX11L2, or SIL-TAL1 expression. The negative effect of NOTCH1 mutation on prognosis was potentiated by HOX11L2 but was attenuated by HOX11. Conclusion: NOTCH1 mutation is an important prognostic marker in T-ALL and its predictive value could be even further increased if coevaluated with other T-cell-related regulatory genes. NOTCH pathway thus acts combinatorially with oncogenic transcriptional factors on T-ALL pathogenesis.

Familiar clustering of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) has been frequently reported. However, limited information is available about the underlying molecular mechanisms in HBV-related HCC patients with family history of HCC. In our previous study, Agilent miRNA Base 16.0 microarray showed miRNA profiles of the plasma of HBV-related HCC patients who had a family history of HCC. This study aims to explore the expression, function, and mechanisms of miR-3188 in HCC that might provide novel insights into the role of family history on the risk of HCC. The expression levels of miR-3188 were markedly overexpressed in HCC tissues, HBV transgenic mice, and HepG2.215 cells. We knocked out miR-3188 in HCC cell lines using the CRISPR/Cas9 system, and demonstrated that miR-3188 knockout (KO) suppressed cell growth, migration, and invasion, and inhibited xenografts tumor growth in nude mice. Next, we determined that miR-3188 KO exerts antitumor functions by directly repressing ZHX2. It has been reported that HBV X protein (HBx) plays a critical role in HBV-related HCC, promoting CREB-mediated activation of miR-3188 and activation of Notch signaling through repressing ZHX2. Finally, we verified that ZHX2 functions as a transcriptional repressor to Notch1 via interaction with NF-YA. Our data demonstrate that the HBx–miR-3188–ZHX2-Notch1 signaling pathway plays an important role in the pathogenesis and progression of HBV-related HCC with family history of HCC. These findings have important implications for identifying new therapeutic targets in HBV-related HCC.

Background:Accumulating evidence indicates that N-cadherin is a cell adhesion molecule that has critical roles in tumour progression. However, the role of N-cadherin in hepatocellular carcinoma (HCC) remains controversial.Methods:This study aims to investigate the expression status of N-cadherin and its molecular mechanisms in HCC.Results:The expression of N-cadherin was markedly overexpressed in HCC tissues and cell lines. We identified that miR-199b-5p binds to the 3′-UTR of N-cadherin mRNA, thus decreasing N-cadherin expression in HCC cells. We also found the downregulation of miR-199b-5p in HCC specimens, which was inversely correlated with N-cadherin upregulation, predicted poor clinical outcomes in HCC patients. Next, we determined that miR-199b-5p overexpression promoted cell aggregation, suppressed cell migration and invasion in HCC cells, and inhibited xenografts tumour metastasis in nude mice. Moreover, we demonstrated that miR-199b-5p attenuated TGF-β1 induced epithelial–mesenchymal transition (EMT) -associated traits, while its effects could be partially reversed by N-cadherin restoration. Finally, we examined that N-cadherin downregulation or miR-199b-5p overexpression suppressed TGF-β1-induced Akt phosphorylation, and inhibition of PI3K/Akt pathway blocked TGF-β1-induced N-cadherin overexpression in HCC cells.Conclusions:Our data demonstrate that N-Cadherin was markedly overexpressed and miR-199b-5p was significantly downregulated in HCC. MiR-199b-5p exerts inhibitory effects on EMT, and directly targets N-cadherin in HCC, supporting the potential utility of miR-199b-5p as a promising strategy to treat HCC. Also, a positive regulatory loop exists between N-cadherin and Akt signalling represents a novel mechanism of TGF-β1-mediated EMT in HCC cells.