SLC35A2 expression drives breast cancer progression via ERK pathway activation.

Alterations in glycosylation are associated with breast tumor formation and progression. Nevertheless, the specific functions and mechanisms of the human major UDP-galactose transporter-encoding gene solute carrier family 35 member A2 (SLC35A2) in breast invasive carcinoma (BRCA) have not been fully determined. Here, we report that SLC35A2 promotes BRCA progression by activating extracellular signal regulated kinase (ERK). SLC35A2 expression and prognosis-predictive significance in pan-cancer were evaluated using public databases. The upstream non-coding RNAs (ncRNAs) of SLC35A2 were analyzed, and their expression and regulations were validated in breast tissues and cell lines by a quantitative PCR and dual-luciferase assays. We used bioinformatic tools to assess the link between SLC35A2 expression and immune infiltration and performed immunohistochemistry for validation. Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, transwell, flow cytometer and western blotting were used to assess the proliferation, motility, cell cycle and apoptosis of BRCA cells in vitro. The xenograft models were constructed to assess the effect of SLC35A2 on BRCA tumor growth in vivo. The results indicated that SLC35A2 expression was upregulated and linked to an unfavorable prognosis in BRCA. The most likely upstream ncRNA-associated pathway of SLC35A2 in BRCA was the AC074117.1/hsa-let-7b-5p axis. SLC35A2 expression had positive correlations with the presence of Th2 cells, regulatory T cells and immune checkpoints. Knockdown of SLC35A2 could reduce BRCA cell proliferation, motility, and cause G2/M arrest and cell apoptosis via ERK signaling. Moreover, ERK activation can rescue the inhibitory effects of knockdown SLC35A2 in BRCA. In conclusion, AC074117.1/hsa-let-7b-5p axis-mediated high expression of SLC35A2 acts as a tumor promoter in BRCA via ERK signaling, which provides a potential target for BRCA treatment.

Hepatitis B Virus Core Protein Mediates the Upregulation of C5α Receptor 1 via NF-κB Pathway to Facilitate the Growth and Migration of Hepatoma Cells.

PURPOSE: C5α receptor 1 (C5ΑR1) is associated with the development of various human cancers. However, whether it is involved in the development of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is poorly understood. We explored the expression, biological role, and associated mechanisms of C5AR1 in HBV-related hepatoma cells. MATERIALS AND METHODS: The expression of C5ΑR1 mediated by HBV and HBV core protein (HBc) was detected in hepatoma cells. The function of nuclear factor кB (NF-κB) pathway in HBc-induced C5AR1 expression was assessed. The roles of C5ΑR1 in the activation of intracellular signal pathways, the upregulation of inflammatory cytokines, and the growth and migration of hepatoma cells mediated by HBc, were investigated. The effect of C5α in the development of HCC mediated by C5AR1 was also measured. RESULTS: C5ΑR1 expression was increased in HBV-positive hepatoma cells. Dependent on HBc, HBV enhanced the expression of C5ΑR1 at the mRNA and protein levels. Besides, HBc could promote C5ΑR1 expression via the NF-κB pathway. Based on the C5ΑR1, HBc facilitated the activation of JNK and ERK pathways and the expression and secretion of interleukin-6 in hepatoma cells. Furthermore, C5ΑR1 was responsible for enhancing the growth and migration of hepatoma cells mediated by HBc. Except these, C5α could promote the malignant development of HBc-positive HCC via C5AR1. CONCLUSION: We provide new insight into the mechanisms of hepatocarcinogenesis mediated by HBc. C5ΑR1 has a significant role in the functional abnormality of hepatoma cells mediated by HBc, and might be utilized as a potential therapeutic target for HBV-related HCC.

Hepatitis B virus core protein promotes the expression of neuraminidase 1 to facilitate hepatocarcinogenesis.

Neuraminidase 1 (NEU1) has been reported to be associated with hepatocellular carcinoma (HCC). However, the function and associated molecular mechanisms of NEU1 in hepatitis B virus (HBV)-related HCC have not been well investigated. In the present study, the expression of NEU1 mediated by HBV and HBV core protein (HBc) was measured in hepatoma cells. The expression of NEU1 protein was detected via immunohistochemical analysis in HBV-associated HCC tissues. The role of NEU1 in the activation of signaling pathways and epithelial-mesenchymal transition (EMT) and the proliferation and migration of hepatoma cells mediated by HBc was assessed. We found that NEU1 was upregulated in HBV-positive hepatoma cells and HBV-related HCC tissues. HBV promoted NEU1 expression at the mRNA and protein level via HBc in hepatoma cells. Mechanistically, HBc was able to enhance the activity of the NEU1 promoter through NF-κB binding sites. In addition, through the increase in NEU1 expression, HBc contributed to activation of downstream signaling pathways and EMT in hepatoma cells. Moreover, NEU1 facilitated the proliferation and migration of hepatoma cells mediated by HBc. Taken together, our findings provide novel insight into the molecular mechanism underlying the oncogenesis mediated by HBc and demonstrate that NEU1 plays a vital role in HBc-mediated functional abnormality in HCC. Thus, NEU1 may serve as a potential therapeutic target in HBV-associated HCC.

Interleukin-34 mediated by hepatitis B virus X protein via CCAAT/enhancer-binding protein α contributes to the proliferation and migration of hepatoma cells.

OBJECTIVES: Interleukin-34 (IL-34) is associated with hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC). However, the role and associated mechanisms of IL-34 in HBV-related HCC remain unclear. In this study, the expression, biological function and associated mechanisms of IL-34 in HBV-related HCC cells were investigated. METHODS: IL-34 expression induced by HBV and HBV X (HBX) gene was measured in hepatoma cells. The role of CCAAT/enhancer-binding protein α (CEBP/α) in HBX-induced IL-34 expression was examined. The signal pathways involved in the expression of CEBP/α and IL-34 induced by HBX were assessed. The role of IL-34 in the proliferation and migration of HCC cells, and related mechanisms were explored. RESULTS: Dependent on HBX, HBV increased IL-34 expression in hepatoma cells, and HBX upregulated and interacted with CEBP/α to enhance the activity of IL-34 promoters. CEBP/α mediated by HBX was associated with the activation of PI3-K and NF-κB pathways to promote IL-34 expression. Via CSF1-R and CD138, IL-34 promoted the proliferation and migration of hepatoma cells, and contributed to the activation of ERK and STAT3 pathways and the upregulation of Bcl-xl and c-Myc mediated by HBX. CONCLUSION: We demonstrate that IL-34 contributes to HBX-mediated functional abnormality of HCC cells and provides a novel insight into the molecular mechanism of carcinogenesis mediated by HBX.