Beta-Catenin in Non-Small Cells Lung Cancer and Its Association with Proteasomes

NOVA1 promotes NSCLC proliferation and invasion by activating Wnt/β-catenin signaling

BACKGROUND

Neuro-oncological ventral antigen 1 (NOVA1) is a neuron-specific RNA-binding protein which regulates alternative splicing in the developing nervous system. Recent research has found that NOVA1 plays a significant role in carcinogenesis. In this paper, we examine the role of NOVA1 in non-small cell lung cancer (NSCLC) and its underlying molecular mechanisms.

METHODS

The expression of NOVA1 in NSCLC was detected by immunohistochemistry and correlations between NOVA1 expression and clinicopathological factors were analyzed by chi-square tests. Kaplan-Meier survival analysis and the Cox regression model were used to evaluate the predictive effect of prognostic factors. Western blotting, Cell Counting Kit-8, colony formation, apoptosis, migration and invasion assays were used to detect the effects of silencing (si)NOVA1 RNA on Wnt/β-catenin signaling and biological behavior in NSCLC cell lines.

RESULTS

Our study showed that expression of NOVA1 was up-regulated and significantly correlated with poor differentiation (p = 0.020), advanced TNM stage (P = 0.001), T stage (P = 0.001) and lymph node metastasis (P = 0.000) as well as the expression of β-catenin (P = 0.012) in NSCLC. The down-regulation of NSCLC by siRNA significantly inhibited proliferation, migration and invasion and promoted apoptosis in NSCLC cells. Expression of Wnt signaling molecules, including β-catenin, activated β-catenin, cyclin D1, matrix metalloproteinase (MMP)-2 and MMP-7, was also significantly reduced by siNOVA1. The inhibition of Wnt/β-catenin signaling in A549 and H1299 cells by siNOVA1 was reversed after treatment with a β-catenin expression plasmid.

CONCLUSION

The present study suggests that NOVA1 may serve as a potential prognosis biomarker in NSCLC. High NOVA1 expression was associated with poor survival rate. Finally, in vitro experiments verified that NOVA1 promotes NSCLC cell proliferation and invasion by regulating Wnt/β-catenin signaling.

Loss of DSTYK activates Wnt/β-catenin signaling and glycolysis in lung adenocarcinoma

Aberrant activation of Wnt/β-catenin signaling and dysregulation of metabolism have been frequently observed in lung cancer. However, the molecular mechanism by which Wnt/β-catenin signaling is regulated and the link between Wnt/β-catenin signaling and cancer metabolism are not fully understood. In this study, we showed that the loss of dual serine/threonine tyrosine protein kinase (DSTYK) led to the activation of Wnt/β-catenin signaling and upregulation of its target gene, lactate dehydrogenase (LDHA), and thus the elevation of lactate. DSTYK phosphorylated the N-terminal domain of β-catenin and inhibited Wnt/β-catenin signaling, which led to the inhibition of cell growth, colony formation and tumorigenesis in a lung adenocarcinoma mouse model. DSTYK was downregulated in lung cancer tissues, and its expression was positively correlated with the survival of patients with lung adenocarcinoma. Taken together, these results demonstrate that the loss of DSTYK activates Wnt/β-catenin/LDHA signaling to promote the tumorigenesis of lung cancer and that DSTYK may be a therapeutic target.

Screening Study on the Anti-Angiogenic Effects of Traditional Chinese Medicine - Part II: Wild Chrysanthemum

Background and Aims: Part 2 of our ongoing research with anti-angiogenic effects focuses on Wild chrysanthemum; a heat-clearing and detoxicating Traditional Chinese Medicine (TCM). We screened six heat-clearing and detoxicating TCM and noticed that wild chrysanthemum has a potent anti-angiogenic effect in zebrafish. This study aims to determine the genetic mechanisms underlying the anti-angiogenic effects of wild chrysanthemum.

Methods:Wild chrysanthemum was decocted, concentrated, sieved and desiccated to attain the water extract. 200μg/mL wild chrysanthemum water extract (WCWE) was diluted in 0.1% dimethyl sulfoxide (DMSO) and given to zebrafish via fish water. 48h post-fertilization (hpf) fli1a-EGFP transgenic zebrafish were used to assay angiogenesis. mRNA-seq, qRT-PCR assay and a parallel reaction monitor (PRM) were carried out to reveal the underlying mechanisms.

Results: WCWE showed a significant anti-angiogenic effect in zebrafish. The results of mRNA-seq showed that there were 1119 genes up-regulated and 1332 genes down-regulated by WCWE. The bioinformatic analysis based on mRNA-seq demonstrated that the proteasome signaling pathway was significantly down-regulated. The results of the qRT-PCR assay were consistent with those of the mRNA-seq assay. The results of the PRM assay showed that nine proteins involved in proteasome signaling and the protein expression level of ctnnb2 were significantly down-regulated. The results of the KEGG pathway analysis based on PRM assay demonstrated that WCWE may have an inhibitory action on the regulatory particle of the proteasome.

Conclusion:Wild chrysanthemum has a significant anti-angiogenic effect in zebrafish and it may have an inhibitory action on the regulatory particle of the proteasome. The mechanisms underlying the anti-angiogenic effects of wild chrysanthemum may be related to the down-regulation of proteasome/β-catenin signaling in zebrafish.