The pathological significance and potential mechanism of ACLY in cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a rare cancer, yet its incidence and mortality rates have been steadily increasing globally over the past few decades. Currently, there are no effective targeted treatment strategies available for patients. ACLY (ATP Citrate Lyase), a key enzyme in de novo lipogenesis, is aberrantly expressed in several tumors and is associated with malignant progression. However, its role and mechanisms in CCA have not yet been elucidated. The expression of ACLY in CCA was assessed using transcriptomic profiles and tissue microarrays. Kaplan-Meier curves were employed to evaluate the prognostic significance of ACLY in CCA. Functional enrichment analysis was used to explore the potential mechanisms of ACLY in CCA. A series of assays were conducted to examine the effects of ACLY on the proliferation and migration of CCA cells. Ferroptosis inducers and inhibitors, along with lipid peroxide probes and MDA assay kits, were utilized to explore the role of ACLY in ferroptosis within CCA. Additionally, lipid-depleted fetal bovine serum and several fatty acids were used to evaluate the impact of fatty acids on ferroptosis induced by ACLY inhibition. Correlation analyses were performed to elucidate the relationship between ACLY and tumor stemness as well as tumor microenvironment. The expression of ACLY was found to be higher in CCA tissues compared to adjacent normal tissues. Patients with elevated ACLY expression demonstrated poorer overall survival outcomes. ACLY were closed associated with fatty acid metabolism and tumor-initiating cells. Knockdown of ACLY did not significantly impact the proliferation and migration of CCA cells. However, ACLY inhibition led to increased accumulation of lipid peroxides and enhanced sensitivity of CCA cells to ferroptosis inducers. Polyunsaturated fatty acids were observed to inhibit the proliferation of ACLY-knockdown cells; nonetheless, this inhibitory effect was diminished when the cells were cultured in medium supplemented with lipid-depleted fetal bovine serum. Additionally, ACLY expression was negatively correlated with immune cell infiltration and immune scores in CCA. ACLY promotes ferroptosis by disrupting the balance of saturated and unsaturated fatty acids. ACLY may therefore serve as a potential diagnostic and therapeutic target for CCA.

Sun X ，Zhao X ，Wang S ，Liu Q ，Wei W ，Xu J ，Wang H ，Yang W ... -  《Frontiers in Immunology》

miR-378 serves as a prognostic biomarker in cholangiocarcinoma and promotes tumor proliferation, migration, and invasion.

Zhou Z ，Ma J 《-》

HSDL2 knockdown promotes the progression of cholangiocarcinoma by inhibiting ferroptosis through the P53/SLC7A11 axis.

Human hydroxysteroid dehydrogenase-like 2 (HSDL2), which regulates cancer progression, is involved in lipid metabolism. However, the role of HSDL2 in cholangiocarcinoma (CCA) and the mechanism by which it regulates CCA progression by modulating ferroptosis are unclear. HSDL2 expression levels in CCA cells and tissues were determined by quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry. The overall survival and disease-free survival of patients with high vs. low HSDL2 expression were evaluated using Kaplan-Meier curves. The proliferation, migration, and invasion of CCA cells were assessed using Cell Counting Kit-8, colony formation, 5-ethynyl-2'-deoxyuridine DNA synthesis, and transwell assays. The effect of p53 on tumor growth was explored using a xenograft mouse model. The expression of SLC7A11 in patients with CCA was analyzed using immunofluorescence. Ferroptosis levels were measured by flow cytometry, malondialdehyde assay, and glutathione assay. HSDL2-regulated signaling pathways were analyzed by transcriptome sequencing. The correlation between p53 and SLC7A11 was assessed using bioinformatics and luciferase reporter assays. HSDL2 expression was lower in primary human CCA tissues than in matched adjacent non-tumorous bile duct tissues. HSDL2 downregulation was a significant risk factor for shorter overall survival and disease-free survival in patients with CCA. In addition, HSDL2 knockdown enhanced the proliferation, migration, and invasion of CCA cells. The transcriptome analysis of HSDL2 knockdown cells showed that differentially expressed genes were significantly enriched in the p53 signaling pathway, and HSDL2 downregulation increased SLC7A11 levels. These findings were consistent with the qRT-PCR and western blotting results. Other experiments showed that p53 expression modulated the effect of HSDL2 on CCA proliferation in vivo and in vitro and that p53 bound to the SLC7A11 promoter to inhibit ferroptosis. HSDL2 knockdown promotes CCA progression by inhibiting ferroptosis through the p53/SLC7A11 axis. Thus, HSDL2 is a potential prognostic marker and therapeutic target for CCA.

Ma S ，Ma Y ，Qi F ，Lei J ，Chen F ，Sun W ，Wang D ，Zhou S ，Liu Z ，Lu Z ，Zhang D ... -  《World Journal of Surgical Oncology》

Long non-coding RNA MIR22HG inhibits cell proliferation and migration in cholangiocarcinoma by negatively regulating the Wnt/β-catenin signaling pathway.

Cholangiocarcinoma (CCA) is one of the most common primary biliary malignant tumors with a high mortality. MIR22HG has been reported to act as a tumor-suppressor gene in several types of cancers. However, the role and molecular regulatory mechanism of MIR22HG in CCA still remains unclear. The present study aimed to investigate the role and underlying mechanism of MIR22HG in CCA. The expression of MIR22HG was detected by RT-qPCR assayin CCA tissues and cells. CCK-8, colony formation and transwell assays were performed to study the biological function of MIR22HG in CCA. Western blot and immunofluorescence assays were performed to detect the expression ofWnt/β-catenin signaling pathway markers. In vivo assays were conducted to explore the biological role of MIR22HG. We first found that MIR22HG expression was significantly down-regulated in CCA tissues and cell lines. Moreover, MIR22HG expression was related to TNM stage and bore prognostic significance in CCA patients. Function experiments demonstrated that overexpression of MIR22HG inhibited cell proliferation, migration and invasion in CCA, whereas knockdown of MIR22HG caused the opposite result. It was found that MIR22HG negatively regulated mRNA and the expression levels of proteins in the Wnt/β-catenin signaling pathway (β-catenin, cyclin D1 and c-myc). The effect of MIR22HG overexpression on CCA progression could be partly rescued by activating the Wnt/β-catenin signaling pathway. MIR22HG suppressed CCA tumorigenesis in vivo. In summary, the results of the present study show that MIR22HG repressed cell proliferation, migration and invasion in CCA by negatively regulating the Wnt/β-catenin signaling pathway. MIR22HG may be a novel target for diagnosis and therapy in CCA.

Hu X ，Tan Z ，Yang Y ，Yang P ... -  《-》

ATP-citrate lyase regulates stemness and metastasis in hepatocellular carcinoma via the Wnt/β-catenin signaling pathway.

Hepatocellular carcinoma (HCC) is one of the most highly malignant tumors. Liver tumor-initiating cells (LTICs) have been considered to contribute to HCC progression and metastasis. ATP-citrate lyase (ACLY), as a key enzyme for de novo lipogenesis, has been reported to be upregulated in various tumors. However, its expression and role in HCC and LTICs remain unknown. The expressions of ACLY in HCC tissues were detected by quantitative real-time PCR (qRT-PCR), Western blotting and immunohistochemistry. Kaplan-Meier curves and Chi-square test were used to determine the clinical significance of ACLY expression in HCC patients. A series of assays were performed to determine the function of ACLY on stemness, migration and invasion of HCC cells. Luciferase reporter assay, Western blotting and immunoprecipitation were used to study the regulation of the Wnt/β-catenin signaling by ACLY. Rescue experiments were performed to investigate whether β-catenin was the mediator of ACLY-regulated stemness and migration in HCC cells. ACLY was highly expressed in HCC tissues and LTICs. Overexpression of ACLY was significantly correlated with poor prognosis, progression and metastasis of HCC patients. Knockdown of ACLY remarkably suppressed stemness properties, migration and invasion in HCC cells. Mechanistically, ACLY could regulate the canonical Wnt pathway by affecting the stability of β-catenin, and Lys49 acetylation of β-catenin might mediate ACLY-regulated β-catenin level in HCC cells. ACLY is a potent regulator of Wnt/β-catenin signaling in modulating LTICs stemness and metastasis in HCC. ACLY may serve as a new target for the diagnosis and treatment of HCC.

Han Q ，Chen CA ，Yang W ，Liang D ，Lv HW ，Lv GS ，Zong QN ，Wang HY ... -  《-》