Polymorphisms in Genes of Tricarboxylic Acid Cycle Key Enzymes Are Associated with Early Recurrence of Hepatocellular Carcinoma

A novel cuproptosis-related immune checkpoint gene signature identification and experimental validation in hepatocellular carcinoma

Copper-induced death, also termed cuproptosis, is a novel form of programmed cell death and is promising as a new strategy for cancer therapeutics. Elevated copper levels in tumor cells are positively associated with high PD-L1 expression. Nonetheless, the prognostic significance of cuproptosis-related immune checkpoint genes (CRICGs) in hepatocellular carcinoma remains to be further clarified. This study aimed to construct the prognostic CRICG signature to predict the immunotherapy response and outcomes of HCC patients. The co-expressed CRICGs were first screened through Pearson correlation analysis. Based on the least absolute shrinkage and selection operator-COX regression analyses, we identified a prognostic 5-CRICGs model, which closely correlates with poor outcomes, cancer development, and immune response to hepatocellular carcinoma. External validation was conducted using the GSE14520 dataset. Lastly, qRT-PCR was performed to determine the expression of the CRICGs in HCC. In summary, we developed and validated a novel prognostic CRICG model based on 5 CRICGs. This prognostic signature could effectively forecast the outcomes and immune response of HCC patients, which may serve as biomarkers for anticancer therapy.

A prognostic signature of cuproptosis and TCA-related genes for hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the most common malignant tumor of the liver. Cuproptosis is a newly defined form of cell death. Copper ion induces cell death by binding to the tricarboxylic acid cycle (TCA). The effect of cuproptosis-related and TCA-related genes on the clinical prognosis of HCC is still unclear. In this study, we explores the genetic changes of cuproptosis-related genes that affect the TCA process and their potential therapeutic value in HCC patients.

Methods

The cuproptosis and TCA-related genes were obtained from cuproptosis-related articles and the molecular signatures database. The prognosis signatures of eight related genes were constructed using the last absolute shrinkage and selection operator (LASSO), and Receiver Operating Characteristic (ROC) curves were used to evaluate the signature. In addition, we analyzed downstream functional enrichment and immune infiltration to explore cuproptosis-inducing drugs and immunotherapeutic responses. All these analyses were validated using multiple datasets of the International Cancer Genome Consortium (ICGC).

Results

TCA and copper malnutrition-related genes (CDKN2A, IDH1, OGDHL, IDH3G, IDH3B, GLS, DLAT, LIPT1) were finally included. According to the risk score, they were divided into high-risk and low-risk groups. Survival analysis showed that the overall survival (OS) of the high-risk group was significantly lower than that of the low-risk group. We established a risk prognostic feature to predict the OS of patients with HCC. Based on this feature and the clinical stage, we constructed a nomogram. Functional enrichment analysis revealed pathways related to organelle division and the cell cycle. Different risk scores had different immune abundances in immune cells (including macrophages and regulatory T-cells) and immune pathways (including antigen-presenting cells co-stimulation). Moreover, the drug sensitivity of eleschomol and PD-L1 in the high-risk group was better than that in the low-risk group. The status of TP53 somatic mutation was also closely related to the risk score.

Conclusion

In this study, we established a new prediction signature of eight genes related to cuproptosis and the TCA process, which can effectively predict the prognosis of HCC patients.

Atypical immunometabolism and metabolic reprogramming in liver cancer: Deciphering the role of gut microbiome

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related mortality worldwide. Much recent research has delved into understanding the underlying molecular mechanisms of HCC pathogenesis, which has revealed to be heterogenous and complex. Two major hallmarks of HCC include: (i) a hijacked immunometabolism and (ii) a reprogramming in metabolic processes. We posit that the gut microbiota is a third component in an entanglement triangle contributing to HCC progression. Besides metagenomic studies highlighting the diagnostic potential in the gut microbiota profile, recent research is pinpointing the gut microbiota as an instigator, not just a mere bystander, in HCC. In this chapter, we discuss mechanistic insights on atypical immunometabolism and metabolic reprogramming in HCC, including the examination of tumor-associated macrophages and neutrophils, tumor-infiltrating lymphocytes (e.g., T-cell exhaustion, regulatory T-cells, natural killer T-cells), the Warburg effect, rewiring of the tricarboxylic acid cycle, and glutamine addiction. We further discuss the potential involvement of the gut microbiota in these characteristics of hepatocarcinogenesis. An immediate highlight is that microbiota metabolites (e.g., short chain fatty acids, secondary bile acids) can impair anti-tumor responses, which aggravates HCC. Lastly, we describe the rising 'new era' of immunotherapies (e.g., immune checkpoint inhibitors, adoptive T-cell transfer) and discuss for the potential incorporation of gut microbiota targeted therapeutics (e.g., probiotics, fecal microbiota transplantation) to alleviate HCC. Altogether, this chapter invigorates for continuous research to decipher the role of gut microbiome in HCC from its influence on immunometabolism and metabolic reprogramming.

Association between the functional polymorphism Ile31Phe in the AURKA gene and susceptibility of hepatocellular carcinoma in chronic hepatitis B virus carriers

Aurora kinase A (AURKA) is a serine threonine kinase which affects chromosomal separation and mitotic spindle stability through interaction with the centrosome during mitosis. Two functional nonsynonymous polymorphisms of the AURKA gene (Ile31Phe and Val57Ile) have been reported recently. We analyzed the association between the two polymorphisms and risk of the occurrence of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) in the Guangxi population consisting of 348 patients with HCC and 359 control subjects, and then validated the significant association in the Guangdong population consisting of 440 cases and 456 controls. All of the participants were of Chinese origin and HBV carriers. The two polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism assay or Sequenom MassARRAY iPLEX platform. In the Guangxi population, carriers of the AURKA 31Phe allele (Ile/Phe + Phe/Phe) were significantly associated with decreased susceptibility to HBV-related HCC when compared with noncarriers (Ile/Ile) (odds ratio [OR] = 0.63, 95% confidence interval [CI] = 0.46-0.86, P = 3.4 × 10^-3). On the contrary, no significant association was found between Val57Ile and HBV-related HCC occurrence. The association of Ile31Phe with HBV-related HCC occurrence was confirmed in the Guangdong population (OR = 0.64, 95% CI = 0.49-0.83, P = 8.0 × 10^-4). The pooled analysis gave a joint P value of 5.5 × 10^-6 (joint OR = 0.63, 95% CI = 0.52-0.77). Our findings suggest that AURKA Ile31Phe may play a role in mediating the susceptibility to HBV-related HCC among Chinese.