This study experimentally validated that PDIA6 promotes the proliferation and metastasis of HCC cells and uncovered the HCC-promoting mechanism of the PDIA6-AKAP12-Wnt signaling axis and highlights its great potential for the development of therapeutic targets in HCC.
Abstract
The continuously rising incidence and persistently high mortality of hepatocellular carcinoma (HCC) have created an urgent need for a deeper understanding of the molecular mechanisms underlying this disease. In the present study, leveraging multiple HCC transcriptome databases, we employed expression analysis, correlation analysis, Gene Set Variation Analysis (GSVA), and cox regression analysis to identify that aberrant upregulation of PDIA6 represents a promising prognostic biomarker associated with adverse clinical outcomes in HCC. Using a series of in vitro oncology research approaches, as well as nude mouse models of subcutaneous tumor formation and lung metastasis, we experimentally validated that PDIA6 promotes the proliferation and metastasis of HCC cells. Through transcriptome sequencing analysis and subsequent rescue experiments, we further confirmed that PDIA6 enhances HCC cell proliferation and migration by activating the Wnt signaling pathway. Combined analysis via immunoprecipitation-mass spectrometry and proteomics revealed that PDIA6 significantly downregulates the expression of the tumor suppressor gene AKAP12. Subsequent rescue experiments demonstrated that PDIA6 drives HCC progression in a manner dependent on the reduced expression of AKAP12. Utilizing protein half-life assays, ubiquitination assays, and co-IP experiments, we uncovered the underlying mechanism: PDIA6 competitively binds to the UCH domain of USP24, which impairs the deubiquitinating activity of USP24 towards AKAP12. This ultimately leads to enhanced K48-linked ubiquitination of AKAP12 and its subsequent proteasomal degradation. We further verified, using specific activators, that AKAP12 inhibits the Wnt signaling pathway in a PKA-dependent manner. In vivo, targeted inhibition of PDIA6 exhibited a more potent therapeutic effect on Wnt-positive HCC tumors.Conclusion Collectively, our study demonstrates the HCC-promoting mechanism of the PDIA6-AKAP12-Wnt signaling axis and highlights its great potential for the development of therapeutic targets in HCC.
HCC (Hepatocellular carcinoma) is one of the malignant tumors with high morbidity and mortality worldwide. Its pathogenesis is complex and the efficacy of existing treatments is limited. Therefore, in-depth exploration of key regulatory molecules and their mechanisms is of great significance for the early diagnosis and targeted therapy of HCC. In this study, HCC cell lines Huh-7 and HepG2 were used as research models to systematically investigate the biological function and molecular regulatory mechanism of FAM117B (family with sequence similarity 117 member B) in HCC progression through gene knockdown and overexpression, cell functional assays, co-immunoprecipitation coupled with mass spectrometry, post-translational modification detection, transcriptome sequencing and nude mouse subcutaneous tumorigenesis assays. High FAM117B expression predicted poor prognosis and positively correlated with pathological grade; functionally, FAM117B exhibited robust oncogenic activity, where its knockdown suppressed proliferation, clonogenicity, invasion, and migration, and its overexpression enhanced these phenotypes. Mechanistic studies revealed that FAM117B directly physically interacted with NAT10 (N-acetyltransferase 10), an acetyltransferase, forming a bidirectional regulatory loop: on the one hand, FAM117B maintained the protein stability of NAT10 by inhibiting its K48-linked ubiquitination and subsequent proteasomal degradation; on the other hand, NAT10, as a key acetyltransferase, specifically mediated the acetylation of FAM117B at lysine 429, providing a molecular basis for the functional role of FAM117B. Transcriptome sequencing and molecular verification demonstrated that the FAM117B/NAT10 axis targeted and regulated JAK2 (Janus kinase 2) expression, activated the downstream JAK-STAT3 (signal transducer and activator of transcription 3) signaling pathway, and thereby drove the malignant biological behaviors of HCC cells. In vivo, dual knockdown of FAM117B and NAT10 significantly reduced xenograft growth, decreased Ki67, and increased apoptosis; notably, NAT10 depletion abrogated the tumor-promoting effects of FAM117B overexpression. In conclusion, this study reveals the molecular mechanism by which FAM117B promotes HCC progression via forming a bidirectional regulatory loop with NAT10 and activating the JAK-STAT3 signaling pathway through acetylation modification, providing a novel potential target and theoretical basis for targeted therapy of HCC.
DBF4B holds promise as both a prognostic biomarker and a novel therapeutic target for HCC after functional experiments demonstrated that silencing DBF4B markedly suppressed the proliferative and migratory capabilities of HCC cells.
Bing Dong, Pengju Xi, Guang-Xin Yang et al.· Molecular Biology Reports· 0 citations
Hepatocellular carcinoma (HCC) is particularly aggressive and difficult to treat. Due to the lack of early clinical diagnosis and the unsatisfactory clinical treatment effect, it is particularly important to identify novel markers that can predict tumor behavior in HCC. biogenesis of ribosomes BRX1 (BRIX1) is abundant in various tissues of the human body. However, the regulatory mechanisms and its role in various tissues are not fully understood. Here, we analyzed the expression pattern of BRIX1 in HCC from public gene expression databases and tissue samples from clinical HCC. We confirmed that BRIX1 was upregulated in both HCC cell lines and HCC paraffin section samples. BRIX1 depletion significantly dicreased the capacity of cells to grow and migrate in vitro, and knockdown BRIX1 suppressed tumor growth in xenograft tumor model. Mechanistically, BRIX1 depletion suppressed the MAPK/ERK pathway, as reflected by reduced phosphorylated ERK (p-ERK) levels. In summary, we provide a rational clue for the further investigation of BRIX1 as an invaluable biological marker for diagnosing and predicting prognosis of patients with HCC.
In this study, we investigated the role of ALKBH5 in the pathogenesis of hepatocellular carcinoma (HCC), focusing on the underlying molecular mechanisms. Comparative analysis of ALKBH5 expression profiles between hepatocellular carcinoma (HCC) tissues and adjacent non-tumorous liver tissues revealed a significant downregulation of ALKBH5 in malignant tissues. To investigate the functional significance of ALKBH5 in HCC pathogenesis, we employed both gain-of-function and loss-of-function approaches in HCC cell lines, utilizing overexpression and RNA interference strategies. Clinical correlation studies demonstrated that decreased ALKBH5 expression levels were significantly associated with reduced overall survival rates in HCC patients, suggesting its potential role as a prognostic biomarker. Furthermore, upregulation of ALKBH5 expression inhibited HCC cell proliferation and induced apoptosis. Through mechanistic studies, we identified SOCS3 as a downstream target of ALKBH5, which negatively regulates the STAT3 signaling pathway. In conclusion, our findings suggest that ALKBH5, as a demethylase, suppresses HCC cell proliferation and promotes apoptosis by reducing methylation levels and modulating the SOCS3/STAT3 pathway. These insights deepen our understanding of the molecular mechanisms underlying HCC and provide potential avenues for future therapeutic development.
Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality worldwide, with limited biomarkers available for early diagnosis and targeted therapy. AKR1B15, a lesser-studied member of the aldo-keto reductase family, shares high sequence similarity with AKR1B10, but its role in HCC remains unclear. Therefore, this study aimed to investigate the biological function of AKR1B15 in HCC and its involvement in oncogenic signaling pathways. Bioinformatic analysis of gene expression datasets and patient tissue samples was used to evaluate AKR1B15 expression and prognostic relevance. Functional assays were conducted following AKR1B15 knockdown, including CCK-8, colony formation, transwell, wound healing, flow cytometry, and xenograft models. Western blotting and immunofluorescence were employed to assess phosphorylation of key signaling molecules. AKR1B15 expression was significantly elevated in HCC tissues and associated with higher pathologic T stage and worse disease-specific survival (P < 0.05). AKR1B15 knockdown inhibited HCC cell proliferation, invasion, and migration (P < 0.01), and promoted apoptosis (P < 0.001). In vivo, AKR1B15 depletion suppressed tumor growth and reduced Ki-67 expression. Mechanistically, silencing AKR1B15 decreased phosphorylation of p53 (Ser15), PI3K (Tyr458/199), AKT (Ser473), mTOR (Ser2448), and E2F1 (S364), indicating inhibition of the p53-PI3K-AKT-mTOR-E2F1 axis. AKR1B15 promotes HCC progression and is associated with activation of the p53-PI3K-AKT-mTOR-E2F1 signaling pathway. It may serve as a novel diagnostic marker and therapeutic target in hepatocellular carcinoma.
Jie Li, Wei-Lai Chen, Pin-Ting Wu et al.· Scientific Reports· 0 citations
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