Studies on the biological functions of CPS1 in AFB1 induced hepatocarcinogenesis

The histone demethylase JMJD1C regulates CPS1 expression and promotes the proliferation of paroxysmal nocturnal haemoglobinuria clones through cell metabolic reprogramming

Paroxysmal nocturnal haemoglobinuria (PNH) is a disorder resulting from erythrocyte membrane deficiencies caused by PIG-A gene mutations. While current treatments alleviate symptoms, they fail to address the underlying cause of the disease-the pathogenic PNH clones. In this study, we found that the expression of carbamoyl phosphate synthetase 1 (CPS1) was downregulated in PNH clones, and the level of CPS1 was negatively correlated with the proportion of PNH clones. Using PIG-A knockout K562 (K562 KO) cells, we demonstrated that CPS1 knockdown increased cell proliferation and altered cell metabolism, suggesting that CPS1 participates in PNH clonal proliferation through metabolic reprogramming. Furthermore, we observed an increase in the expression levels of the histone demethylase JMJD1C in PNH clones, and JMJD1C expression was negatively correlated with CPS1 expression. Knocking down JMJD1C in K562 KO cells upregulated CPS1 and H3K36me3 expression, decreased cell proliferation and increased cell apoptosis. Chromatin immunoprecipitation analysis further demonstrated that H3K36me3 regulated CPS1 expression. Finally, we demonstrated that histone demethylase inhibitor JIB-04 can suppressed K562 KO cell proliferation and reduced the proportion of PNH clones in PNH mice. In conclusion, aberrant regulation of the JMJD1C-H3K36me3-CPS1 axis contributes to PNH clonal proliferation. Targeting JMJD1C with a specific inhibitor unveils a potential strategy for treating PNH patients.

AFB1 Triggers Lipid Metabolism Disorders through the PI3K/Akt Pathway and Mediates Apoptosis Leading to Hepatotoxicity

As the most prevalent mycotoxin in agricultural products, aflatoxin B1 not only causes significant economic losses but also poses a substantial threat to human and animal health. AFB1 has been shown to increase the risk of hepatocellular carcinoma (HCC) but the underlying mechanism is not thoroughly researched. Here, we explored the toxicity mechanism of AFB1 on human hepatocytes following low-dose exposure based on transcriptomics and lipidomics. Apoptosis-related pathways were significantly upregulated after AFB1 exposure in all three hES-Hep, HepaRG, and HepG2 hepatogenic cell lines. By conducting a comparative analysis with the TCGA-LIHC database, four biomarkers (MTCH1, PPM1D, TP53I3, and UBC) shared by AFB1 and HCC were identified (hazard ratio > 1), which can be used to monitor the degree of AFB1-induced hepatotoxicity. Simultaneously, AFB1 induced abnormal metabolism of glycerolipids, sphingolipids, and glycerophospholipids in HepG2 cells (FDR < 0.05, impact > 0.1). Furthermore, combined analysis revealed strong regulatory effects between PIK3R1 and sphingolipids (correlation coefficient > 0.9), suggesting potential mediation by the phosphatidylinositol 3 kinase (PI3K) /protein kinase B (AKT) signaling pathway within mitochondria. This study revealed the dysregulation of lipid metabolism induced by AFB1 and found novel target genes associated with AFB-induced HCC development, providing reliable evidence for elucidating the hepatotoxicity of AFB as well as assessing food safety risks.

Metabolic dysregulation and emerging therapeutical targets for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an aggressive human cancer with increasing incidence worldwide. Multiple efforts have been made to explore pharmaceutical therapies to treat HCC, such as targeted tyrosine kinase inhibitors, immune based therapies and combination of chemotherapy. However, limitations exist in current strategies including chemoresistance for instance. Tumor initiation and progression is driven by reprogramming of metabolism, in particular during HCC development. Recently, metabolic associated fatty liver disease (MAFLD), a reappraisal of new nomenclature for non-alcoholic fatty liver disease (NAFLD), indicates growing appreciation of metabolism in the pathogenesis of liver disease, including HCC, thereby suggesting new strategies by targeting abnormal metabolism for HCC treatment. In this review, we introduce directions by highlighting the metabolic targets in glucose, fatty acid, amino acid and glutamine metabolism, which are suitable for HCC pharmaceutical intervention. We also summarize and discuss current pharmaceutical agents and studies targeting deregulated metabolism during HCC treatment. Furthermore, opportunities and challenges in the discovery and development of HCC therapy targeting metabolism are discussed.

Tandem Mass Tag-Based Proteomic Analysis of Potential Biomarkers for Hepatocellular Carcinoma Differentiation

Purpose

The poor prognosis of hepatocellular carcinoma (HCC) urgent us to discover early and effective biomarkers. In this study, we applied tandem mass tag (TMT)-based proteomic analysis to discover potential protein markers for HCC identification and differentiation.

Patients and Methods

Fifteen patients, well-differentiated (G1, N = 5), moderate-differentiated (G2, N = 5), and poorly differentiated (G3, N = 5), with 30 matched pair tissues (both tumor and adjacent non-tumor tissues derived from the same patient) were enrolled. All samples were subjected to TMT labeling and LC−MS/MS analysis. The identified proteins were subsequently assigned to GO and KEGG for predicting function. The identified protein candidates were validated using immunohistochemistry (IHC).

Results

A total of 1010 proteins were identified. Of these, 154 differentially expressed proteins (DEPs), 100 up-regulated and 54 down-regulated, were found between tumor and adjacent non-tumor tissues; 12 DEPs, 9 up-regulated and 3 down-regulated, were found between G1 and G3 tissues; 8 DEPs, 5 up-regulated and 3 down-regulated, were found between G1 and G2 tissues; 11 DEPs, 8 up-regulated and 3 down-regulated, were found between G2 and G3 tissues. Among them, ASS1 and CPS1 were significantly up-regulated while UROD and HBB were significantly down-regulated in G3 compared with G1 and G2 tumors. Three proteins, CYB5A, FKBP11 and YBX1, were significantly up-regulated in G1 compared with both G2 and G3 tumors. The 7 biomarker candidates were further verified by IHC.

Conclusion

A variety of DEPs related to the histological differentiation of HCC were identified, among which ASS1, CPS1, URPD and HBB proteins were potential biomarkers for distinguishing poorly differentiated HCC, while CYB5A, FKBP11 and YBX1 were potential biomarkers for distinguishing well-differentiated HCC. Our findings may further provide a new insight facilitating the diagnosis and prognosis of HCC.

CPS1 expression and its prognostic significance in lung adenocarcinoma

Background

Studies have increasingly shown that carbamoyl phosphate synthetase 1 (CPS1) plays a vital role in the occurrence and development of human malignant disease. Unfortunately, the detailed function of CPS1 in the development and prognosis of lung cancer, especially lung adenocarcinoma (LADC), is still not fully understood. In this research, we performed a comprehensive bioinformatics analysis with respect to the function of CPS1 in human LADC.

Methods

Several biological databases including UALCAN, GEPIA and Oncomine were used to analyze the expression of CPS1 in LADC. Meanwhile, TCGA and GEO databases were utilized to analyze relevant clinical data. In addition, databases including Methsurv, etc., were used to analyze CPS1 methylation levels in LADC.

Results

The Oncomine platform, UALCAN and gene expression profiling interactive analysis (GEPIA) were used and revealed that the expression levels of CPS1 were significantly increased in LADC tissues. Furthermore, we analyzed the methylation level of CPS1 in LADC and found that cases with high levels of CPS1 showed hypomethylated CPS1. The clinical data from the Wanderer database, which is linked to The Cancer Genome Atlas (TCGA) database, demonstrated that the expression and methylation values of CPS1 were both significantly related to the clinical characteristics and prognosis of LADC. Through analysis of the dataset from the Gene Expression Omnibus (GEO) database, we found that the expression level of CPS1 was markedly downregulated in human A549 lung cancer cells treated with the chemotherapeutic drug motexafin gadolinium (MGd) in a time-dependent manner.

Conclusions

Our work indicated that CPS1 is upregulated in LADC samples and that CPS1 might be used as a potential biomarker for the diagnostic and prognostic evaluation of LADC. Determining the detailed biological function of CPS1 in LADC tissues will provide promising and insightful information for our further study.

Expression and clinical significance of CPS1 in glioblastoma multiforme

Carbamoyl phosphate synthetase-1 (CPS1), the first rate-limiting mitochondrial enzyme in the urea cycle, regulates proliferation and differentiation during tumor progression. However, the detailed function of CPS1 in glioblastoma Multiforme (GBM) is still unclear. Here, we highlight mechanisms for CPS1 upregulation and the effects of upregulated CPS1 on GBM tumorigenesis. The transcriptome data from several public databases, such as Oncomine and GEPIA, revealed that CPS1 transcriptional level was significantly upregulated in GBM tissues and cells. Moreover, CPS1 was hypomethylated in GBM tissues. The Wanderer database, linked to the Cancer Genome Atlas (TCGA), showed the association between CPS1 expression or its methylation values and the clinicopathological parameters in GBM patients. Our work fully demonstrated that CPS1 expression was upregulated in GBM and this gene could be used as a potential diagnostic and prognosis indicator for GBM.