Clinical Significance of Acylphosphatase 1 Expression in Combined HCC-iCCA, HCC, and iCCA

Targeting ACYP1-mediated glycolysis reverses lenvatinib resistance and restricts hepatocellular carcinoma progression

Acylphosphatase 1 (ACYP1), a protein located in the mammalian cell cytoplasm, has been shown to be associated with tumor initiation and progression by functioning as a metabolism-related gene. Here we explored the potential mechanisms by which ACYP1 regulates the development of HCC and participates in the resistance to lenvatinib. ACYP1 can promote the proliferation, invasion, and migration capacities of HCC cells in vitro and in vivo. RNA sequencing reveals that ACYP1 markedly enhances the expression of genes related to aerobic glycolysis, and LDHA is identified as the downstream gene of ACYP1. Overexpression of ACYP1 upregulates LDHA levels, which then increases the malignancy potential of HCC cells. GSEA data analysis reveals the enrichment of differentially expressed genes in the MYC pathway, indicating a positive correlation between MYC and ACYP1 levels. Mechanistically, ACYP1 exerts its tumor-promoting roles by regulating the Warburg effect through activating the MYC/LDHA axis. Mass spectrometry analysis and Co-IP assays confirm that ACYP1 can bind to HSP90. The regulation of c-Myc protein expression and stability by ACYP1 is HSP90 dependent. Importantly, lenvatinib resistance is associated with ACYP1, and targeting ACYP1 remarkably decreases lenvatinib resistance and inhibits progression of HCC tumors with high ACYP1 expression when combined with lenvatinib in vitro and in vivo. These results illustrate that ACYP1 has a direct regulatory role in glycolysis and drives lenvatinib resistance and HCC progression via the ACYP1/HSP90/MYC/LDHA axis. Targeting ACYP1 could synergize with lenvatinib to treat HCC more effectively.

Development and Verification of a Combined Immune- and Metabolism-Related Prognostic Signature for Hepatocellular Carcinoma

Immune escape and metabolic reprogramming are becoming important characteristics of tumor biology, which play critical roles in tumor initiation and progression. However, the integrative analysis of immune and metabolic characteristics for the tumor microenvironment in hepatocellular carcinoma (HCC) remains unclear. Herein, by univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses, a prognostic signature associated with tumor microenvironment was established based on five immune- and metabolism-related genes (IMRGs), which was fully verified and evaluated in both internal and external cohorts. The C-index was superior to previously published HCC signatures, indicating the robustness and reliability of IMRGs prognostic signature. A nomogram was built based on IMRGs prognostic signature and various clinical parameters, such as age and T stage. The AUCs of nomogram at 1-, 3-, and 5-year (AUC = 0.829, 0.749, 0.749) were slightly better than that of IMRGs signature (AUC = 0.809, 0.734, 0.711). The relationship of risk score (RS) with immune checkpoint expressions, immunophenoscore (IPS), as well as microsatellite instability (MSI) together accurately predicted the treatment efficacy. Collectively, the IMRGs signature might have the potential to better predict prognostic risk, evaluate immunotherapy efficacy, and help personalize immunotherapy for HCC patients.

ACYP1 Is a Pancancer Prognostic Indicator and Affects the Immune Microenvironment in LIHC

Background

ACYP1 plays important physiological and metabolic roles in glycolysis and membrane ion pump activity by catalyzing acyl phosphate hydrolysis. ACYP1 is related to tumorigenesis and progression and poor prognosis in gastrointestinal cancer. However, its pancancer roles and mechanisms are unclear. Our study aimed to understand the ACYP1 expression signature and prognostic value across cancers and investigate immune infiltration patterns in liver hepatocellular carcinoma (LIHC) and verify them in LIHC samples.

Methods

Transcriptional expression profiles of ACYP1 across cancers were analyzed using Oncomine and TIMER. The prognostic value of ACYP1 was assessed across PrognoScan, Kaplan—Meier Plotter, and GEPIA. Significant pathways associated with ACYP1 in LIHC were obtained via Gene Set Enrichment Analysis. The correlation between ACYP1 expression and immune infiltration in LIHC was investigated using TIMER. We validated ACYP1 expression, prognostic value, and association with immune cells in tumor tissues by immunohistochemistry and flow cytometry.

Results

ACYP1 was overexpressed across cancers. High expression of ACYP1 correlated with a poor prognosis in most tumor types, especially in LIHC. ACYP1 was significantly implicated in immune and metabolic related pathways. High ACYP1 expression showed significant correlations with the abundances of Th2 cells, Tregs, macrophages, dendritic cells, and myeloid-derived suppressor cells in LIHC. LIHC patients with high ACYP1 expression showed significantly shorter overall survival and relapse-free survival rates concomitant with increased infiltration of CD4+ T cells. Mouse subcutaneous tumors with ACYP1 overexpression exhibited significantly accelerated tumor progression with increased aggregation of CD4+ T cells.

Conclusion

Overall, ACYP1 may serve as a vital prognostic biomarker and play an immunoregulatory role in LIHC.