NAT10 Promotes Malignant Progression of Lung Cancer via the NF-κB Signaling Pathway.

BACKGROUND: NAT10 (N-acetyltransferase 10) is a newly identified novel acetyltransferase. Abnormal expression of NAT10 is associated with several human disorders, including cancer, autoimmune diseases, and cardiovascular disease. This study aimed to investigate the role of NAT10 in promoting lung cancer malignant progression through the NF-κB (nuclear factor κB) signaling pathway. METHODS: Cells lines BEAS-2B, NCI-H524, A549, PC-9, NCI-H23, and NCI-H258 were cultured for identification. Western blotting and PCR assays determined gene expression within the sample cells. Cellular functionality was assayed using CCK8 (Cell Counting Kit-8), Dual-Luciferase Reporter, and Colony formating. RESULTS: The PCR assay and Western blotting showed a significant elevation of NAT10 levels within tumor tissues compared to paraneoplastic tissues (p < 0.05). Specifically, NAT10 only affected the expression and content of RelA/p65 in lung cancer. Analysis from the TCGA (The Cancer Genome Atlas) database indicated that elevated expression levels of NAT10 in tumors can be a good prognostic indicator for lung cancer patients. The CCK8 assay showed that the knockdown of NAT10 significantly suppressed the A549 cells' progression rate (p < 0.05). The colony formation assays further confirmed that the overexpression of NAT10 significantly increased the generation of clones in the NCI-H524 cells (p < 0.05). The proliferation rate influenced by the overexpression of NAT10 was inhibited by blocking the NF-κB signaling pathway (p < 0.05). Dual-luciferase reporter gene assay results revealed NAT10's potential in promoting the NF-κB signaling pathway's activity in lung cancer. Immunohistochemical staining underscored a strong link between NAT10 protein expression and the NF-κB signaling pathway in lung cancer tissues. CONCLUSIONS: NAT10's expression is significantly upregulated in tumor tissues, supported by PCR results. NAT10 plays a role in the development and proliferation of lung cancer cells and can activate the NF-κB signaling pathway in lung cancer. Hence, NAT10's regulation of the NF-κB signaling pathway is critical in the malignant proliferation of lung cancer.

PIK3R6 Promotes Angiogenesis in Hepatocellular carcinoma by Activating STAT3 Signaling Pathway.

Objective: Abundant angiogenesis in hepatocellular carcinoma (HCC) is critical in its malignant course; however, its mechanism is incompletely understood. Meanwhile, the corresponding roles of PIK3R6 molecules in HCC have not been investigated. This study aims to explore the intrinsic mechanism of PIK3R6 and provide theoretical reference for the treatment of hepatocellular carcinoma. Methods: Differential expressions of PIK in ovarian cancer and normal ones were detected by Western blotting and quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Analyze the relationship between the expression of PIK3R6 and patient prognosis through the TCGA database. Subsequently constructed corresponding stable cell lines, combined with transcriptome sequencing and several cell biology experiments, we explored the inner mechanism and clinical significance of PIK3R6. Results: By analyzing multiple cohorts, we found that high PIK3R6 expression in tumor tissues negatively correlates with patient prognosis. PIK3R6 could increase angiogenesis in HCC by boosting the activity of the STAT3 signalling pathway to hasten the malignant progression of the disease, according to corresponding cellular and molecular experimental studies. Then again, immunohistochemistry on a series of tissue chips confirmed the important clinical significance of PIK3R6-STAT3 regulatory axis. Couclusions: This study initially addressed the clinical significance of PIK3R6 and revealed its mechanism for promoting angiogenesis in hepatocellular carcinoma, providing a reliable working foundation for future in-depth research and clinical translation.

RNA-binding motif 4 promotes angiogenesis in HCC by selectively activating VEGF-A expression.

Increased angiogenesis in the liver plays a critical role in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanism underlying increased angiogenesis in HCC is not well understood. Current study was designed to identify the potential angiogenic effect of RNA-binding motif 4 (RBM4)through a small-scale overexpression screening, followed by comparison of the expression level of RBM4 in cancer and adjacent tissues in multiple malignancies to explore the relationship between RBM4 and CD31 protein expression level and related clinical indicators, and understand the role of RBM4 in the hepatocellular carcinoma. To understand the specific mechanism of RBM4 in detail, transcriptome sequencing, mass spectrometry and multiple molecular cytological studies were performed. These cellular level results were verified by experiments in animal models of nude mice. The increased expression of RBM4 in cancer tissues, suggested its use as a prognostic biomarker. The RBM4 expression was found to be strongly correlated with tumor microvessel density. Mechanistically, RBM4 mediated its effects via interaction with HNRNP-M through the latter's WDR15 domain, which then stabilized RelA/p65 mRNA. Consequently, RBM4 induced the activation of the NF-kB signaling pathway, upregulating the expression of proangiogenic factor VEGF-A. The results confirmed the mechanism by which RBM4 promotes angiogenesis in hepatocellular carcinoma suggesting RBM4 as a crucial promoter of angiogenesis in HCC, helping understand regulation of NF-kB signaling in HCC.

DNAAF5 promotes hepatocellular carcinoma malignant progression by recruiting USP39 to improve PFKL protein stability.

Purposes: Dynein axonemal assembly factor 5 (DNAAF5) is the transcription factor of regulating the cytoskeleton and hydrodynamic protein complex assembly, however, it was not well elucidated in the malignant progression of hepatocellular carcinoma (HCC). Methods: We investigated the role of DNAAF5 in hepatocellular carcinoma by using multiple groups of clinical tissues combined with data from the TCGA database. Then we overexpressed DNAAF5 in hepatocellular carcinoma tumor tissues, which correlates with poor patient survival outcomes. Furthermore, we constructed stable cell lines of HCC cells to confirm the cancer-promoting effects of DNAAF5 in hepatocellular carcinoma. To explore the mechanisms of DNAAF5, transcriptome sequencing combined with mass spectrometry was also performed, which showed that DNAAF5 affects its downstream signaling pathway by interacting with PFKL and that DNAAF5 regulates PFKL protein stability by recruiting the deubiquitination protein, USP39. To corroborate these findings, the same series of tissue microarrays were used to confirm correlations between DNAAF5 and PFKL expressions. In animal experiments, DNAAF5 also promoted the proliferation of HCC cells. Results: We found that DNAAF5 expressions were markedly higher in HCC tissues, compared to the adjacent normal tissues. Increased levels of DNAAF5 were associated with significantly worse prognostic outcomes for HCC patients. Cell function experiments showed that HCC cells of overexpressing DNAAF5 exhibited faster proliferation rates, stronger clone formation abilities and higher drug resistance rates. However, tumor cell proliferation rates and colony formation were significantly decreased after DNAAF5 knockout, accompanied by an increase in sensitivity to sorafenib. In addition, the results of our study showed that DNAAF5 accelerates PFKL protein deubiquitination by recruiting USP39 in HCC cells. Furthermore, The overexpression of DNAAF5 could promote HCC cell proliferation in vivo and in vitro, whereas USP39 knockdown inhibited this effect. Overall, DNAAF5 serves as a scaffold protein to recruit USP39 to form a ternary complex by directly binding the PFKL protein, thereby improving the stability of the latter, which promotes the malignant process of hepatocellular carcinoma. Conclusions: These findings revealed DNAAF5 was negatively correlated with the prognosis of patients with hepatocellular carcinoma. It underlying mechanism showed that DNAAF5 directly binds PFKL and recruits the deubiquitinated protein (USP39) to improve the stability of the PFKL protein, thus enhancing abnormal glycolysis in HCC cells.

N4BP3 promotes angiogenesis in hepatocellular carcinoma by binding with KAT2B.

Although angiogenesis is a critical event in hepatocellular carcinoma (HCC), and this process provides the tumor with sufficient oxygen and nutrients, the precise molecular mechanism by which it occurs is not fully understood. NEDD4 binding protein 3 (N4BP3) was identified in this study as a novel pro-angiogenic factor in HCC cell lines and tissues. We discovered that N4BP3 was significantly expressed in HCC and that its level of expression was positively correlated with the density of tumor microvessels in HCC tissues. Cell biology experiments have shown that N4BP3 knockdown in HCC cells significantly inhibits the formation of complete tubular structures by HUVECs in vitro and HCC angiogenesis in vivo. In HCC cells, overexpression of N4BP3 has the opposite effects. Further cell and molecular biology experiments have revealed that N4BP3 interacts with KAT2B (lysine acetyltransferase 2B), increasing signal transducer and activator of transcription 3 (STAT3) expression by regulating the distribution of acetyl-histone H3 (Lys27) (H3K27ac) in its promoter region. This, in addition, regulates the activity of the STAT3 signaling pathway, which promotes the proliferation of microvessels in HCC and accelerates the malignant process of the tumor. In vivo experiments in nude mice have confirmed our findings, and also suggested that N4BP3 could be a potential target for the treatment of HCC in combination with sorafenib.

RBM23 Drives Hepatocellular Carcinoma by Activating NF-κB Signaling Pathway.

PURPOSE: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, and angiogenesis has been proven to be significantly involved in its progression. However, the molecular mechanism underlying HCC angiogenesis has not been well researched. In this study, RNA Binding Motif Protein 23 (RBM23) was identified as a novel proangiogenic factor in HCC cell lines and tissues. MATERIALS AND METHODS: Firstly, we analyzed the correlation of clinical specimens. In HCC tissues, the levels of RBM23 and microvessel density (MVD) showed a strong positive correlation. Furthermore, data from related cytology experiments showed that the knockdown of RBM23 expression in HCC cells significantly inhibited the tube formation by the human vascular endothelial cells in vitro. The mechanism of this phenomenon was found to be through increasing the mRNA of p65 and enhanced the nuclear accumulation of p65. Consequently, RBM23 activated the NF-κB signaling pathway and promoted expression of the proangiogenic cytokines selectively. Results and Conclusion. In summary, this study revealed that RBM23 promotes the angiogenesis properties of HCC via the NF-κB signaling pathway. It may, therefore, be a potential therapeutic target for the treatment of hepatocellular carcinoma.