Unlocking the potential of HHLA2: identifying functional immune infiltrating cells in the tumor microenvironment and predicting clinical outcomes in laryngeal squamous cell carcinoma.

BACKGROUND: HHLA2 (human endogenous retrovirus-H long terminal repeat-associating protein 2) represents a recently identified member of the B7 immune checkpoint family, characterized by limited expression in normal tissues but notable overexpression in various cancer types. Nevertheless, the precise function and interaction with immune cells remain poorly understood, particularly in laryngeal squamous cell carcinoma (LSCC). This investigation endeavored to elucidate the biological significance of HHLA2 within the tumor microenvironment of human LSCC tissues and delineate the clinical relevance and functional roles of HHLA2 in LSCC pathogenesis. METHODS: Through multiplexed immunohistochemistry analyses conducted on tissue microarrays sourced from LSCC patients (n = 72), the analysis was executed to assess the expression levels of HHLA2, density and spatial patterns of CD68+HLA-DR+CD163- (M1 macrophages), CTLA-4+CD4+FoxP3+ (CTLA-4+Treg cells), CTLA-4+CD4+FoxP3- (CTLA-4+Tcon cells), exhausted CD8+T cells, and terminally exhausted CD8+T cells in LSCC tissues. Survival analysis was conducted to evaluate the prognostic significance of HHLA2 and these immune checkpoints or immune cell populations, employing COX regression analysis to identify independent prognostic factors. RESULTS: Kaplan-Meier (K-M) survival curves revealed a significant association between HHLA2 expression and overall survival (OS) in LSCC. Elevated levels of HHLA2 were linked to reduced patient survival, indicating its potential as a prognostic marker (HR: 3.230, 95%CI 0.9205-11.34, P = 0.0067). Notably, increased infiltration of CD68+ cells (total macrophages), STING+CD68+HLA-DR+CD163- (STING+M1 macrophages), CTLA-4+CD4+FoxP3+, CTLA-4+CD4+FoxP3-, PD-1+LAG-3+CD8+T cells, and PD-1+LAG-3+TIM-3+CD8+T cells strongly linked to poorer survival outcomes (P < 0.05). A discernible trend was observed between the levels of these immune cell populations, STING+CD68+ (STING+ total macrophages), CD68+HLA-DR+CD163-, STING+CD68+CD163+HLA-DR- (STING+M2 macrophages), PD-1+LAG-3-CD8+T cells, PD-1+TIM-3+CD8+T cells, and PD-1+LAG-3+TIM-3-CD8+T cells and prognosis. Importantly, multivariate COX analysis identified HHLA2 as an independent predictive factor for OS in LSCC patients (HR = 3.86, 95% CI 1.08-13.80, P = 0.038). This underscored the potential of HHLA2 as a critical marker for predicting patient outcomes in LSCC. CONCLUSIONS: HHLA2 emerged as a detrimental prognostic biomarker for assessing OS in LSCC patients. Relative to other immune checkpoints, HHLA2 exhibited heightened predictive efficacy for the prognosis of LSCC patients.

Prognostic value of lactate dehydrogenase to absolute lymphocyte count ratio and albumin to fibrinogen ratio in diffuse large B-cell lymphoma.

With the continuous improvement of treatment strategy, the prognostic value of international prognostic index (IPI) alone is limited for diffuse large B-cell lymphoma (DLBCL). Our study aims to explore the effect of lactate dehydrogenase (LDH)to absolute lymphocyte count (ALC) ratio (LAR) and albumin to fibrinogen ratio (AFR) on the prognosis of patients with DLBCL. The venous blood LDH, ALC, albumin and fibrinogen within 1 week before the first chemotherapy in 74 DLBCL patients were collected to calculate the LAR and AFR values. The impact of LAR and AFR on the progression-free survival (PFS) of patients with DLBCL was studied by the survival analysis. The area under the receiver operating characteristic curve (AUC) and concordance index (C-index) were used to analyze the predictive efficiency of each model for the PFS of DLBCL patients. Cox univariate analysis suggested that elevated LAR (P < .001) and decreased AFR (P < .001) were risk factors for PFS in DLBCL patients. Multivariate analysis revealed that LAR (P < .001) and AFR (P = .004) were 2 independent prognostic parameters. The AUC values of IPI, AFR + IPI, LAR + IPI and AFR + LAR + IPI to predict the PFS of DLBCL patients were 0.806 (95%CI 0.707-0.905, P < .001), 0.839 (95%CI 0.747-0.932, P < .001), 0.851 (95%CI 0.764-0.938, P < .001), and 0.869 (95%CI 0.787-0.952, P < .001), respectively. The C-index values of above 4 models were 0.802 (95%CI 0.629-0.975, P < .001), 0.842 (95% CI 0.735-0.949, P < .001), 0.846 (95%CI 0.716-0.976, P < .001), and 0.864 (95%CI 0.781-0.941, P < .001), respectively. The results suggest that both LAR and AFR are independent prognostic factors for PFS in DLBCL patients. Furthermore, their combination with IPI has better predictive efficiency for the prognosis of DLBCL patients.

CircHIF1A induces cetuximab resistance in colorectal cancer by promoting HIF1α-mediated glycometabolism alteration.

Epidermal growth factor receptor (EGFR)-targeted therapy is an important treatment for RAS wild-type metastatic colorectal cancer (mCRC), but the resistance mechanism remains unclear. Here, the differential expression of circRNAs between Cetuximab sensitive and resistant cell lines was analyzed using whole-transcriptome sequencing. We identified that the expression of circHIF1A was significantly higher in LIM1215-R than in LIM1215. When treated with Cetuximab, downregulation of circHIF1A level weakened the proliferation and clonal formation ability of LIM1215-R, caused more cells to enter G0-G1 phase, and significantly reduced the basal respiration, ATP production, and maximal respiration, as well as the glycolytic capacity and glycolytic reserve. The response rate and prognosis of circHIF1A-positive patients were inferior to those of negative patients. Mechanistically, circHIF1A can upregulate the level of hypoxia-inducible factor 1 A (HIF1A) by competitively binding to miR-361-5p, inducing the overexpression of enzymes such as glucose transporter 1 (GLUT1) and lactate dehydrogenase A (LDHA). In a xenograft model, inhibition of circHIF1A expression increased the sensitivity to Cetuximab treatment. In conclusion, circHIF1A can promote HIF1α-mediated glycometabolism alteration to induce Cetuximab resistance in CRC. It has the potential to become a screening indicator for the Cetuximab beneficial population in mCRC and a new therapeutic target for enhancing treatment efficacy.

The m6A demethylase FTO targets POLQ to promote ccRCC cell proliferation and genome stability maintenance.

BACKGROUND AND AIM: As the first identified m6A demethylase, FTO has been implicated in the progression of various cancers. However, the specific mechanism of FTO in clear cell renal cell carcinoma (ccRCC) remains incompletely understood. In this study, we aimed to explore the potential molecular mechanisms influencing the progression of ccRCC. METHODS: We initially assessed the expression of FTO in tumor and adjacent tissues using TCGA database, RT-qPCR, and Western blot. We then conducted CCK-8, cell cycle analysis, and colony formation assay to investigate the impact of FTO on ccRCC cell proliferation. MeRIP-seq and RNA-seq were employed to identify potential downstream targets of FTO in ccRCC, and these findings were further validated through dual-luciferase reporter assays and MeRIP-qPCR. Then, DNA damage and cell death were assessed separately through gammaH2AX immunofluorescence detection and the LIVE/DEAD Fixable Dead Cell Stain assay, respectively. Subsequently, we identified downstream pathways influenced by FTO's regulation of POLQ through TCGA database analysis and GSEA enrichment analysis. Validation was carried out through Western blot. RESULTS: FTO is highly expressed in ccRCC tissues and cell lines. Furthermore, ROC curve demonstrates that FTO contributes to the diagnosis of ccRCC. FTO modulates m6A modification, consequently influencing the expression of POLQ, thus facilitating cell proliferation and maintaining genome stability in ccRCC. CONCLUSION: FTO could potentially serve as a diagnostic marker for ccRCC. FTO promotes the progression of ccRCC by regulating m6A modification, making the inhibition of FTO a potential novel therapeutic strategy in ccRCC.