Hepatocellular carcinoma (HCC) is one of the dominating tumors causing death due to lack of timely discovery and valid treatment. Abnormal increase of Rac GTPase activating protein 1 (RACGAP1) has been verified to be an oncogene in plenty tumors. The profound mechanism of RACGAP1 was rarely reported in HCC. In this study, we explored the function and mechanism of RACGAP1 in HCC through multiple analysis and experiments. RACGAP1 expression was up‐regulated in HCC samples and the high expression of RACGAP1 was an independent prognostic risk factor for HCC patients. Meanwhile, RACGAP1 promoted developments of HCC both in vitro and in vivo. We verified that RACGAP1 promoted proliferation of HCC via PI3K/AKT/CDK2 and PI3K/AKT/GSK3β/Cyclin D1 signaling pathway. RACGAP1 accelerated the invasion and metastasis of HCC via phosphorylation of GSK3β and nuclear translocation of β‐catenin. Furthermore, by luciferase reporter assay and Chromatin immunoprecipitation (ChIP) assay, we confirmed Recombinant GA Binding Protein Transcription Factor Alpha (GABPA) regulated the transcription of RACGAP1. All these findings revealed that RACGAP1 promotes the progression of HCC through a novel mechanism, which might be a new therapeutic target for HCC patients.

Recurrence remains a major cause of failure after curative-intent therapy for hepatocellular carcinoma (HCC), including resection, ablation, and liver transplantation. Current surveillance relies on imaging and serum biomarkers, but radiologic relapse may lag behind biological recurrence. This gap has focused attention on circulating tumor DNA (ctDNA) and related cell-free DNA (cfDNA) approaches as candidate tools for minimal residual disease (MRD) assessment and molecular surveillance. In HCC, however, recurrence is biologically heterogeneous. Post-treatment relapse may arise from residual malignant clones, occult intrahepatic spread, or de novo hepatocarcinogenesis in a chronically injured liver. This complexity shapes assay selection, result interpretation, and the need for multimodal risk assessment. Tumor-informed ctDNA assays are best suited to tracking residual clonal disease, whereas methylation-based and composite cfDNA approaches may also capture low-shedding disease and recurrence-prone liver-field biology. Available studies suggest that postoperative ctDNA positivity, persistent serial positivity, rising molecular burden, and selected high-risk methylation signals are associated with recurrence risk after curative-intent therapy. Yet the evidence base is uneven across treatment settings and assay classes, laboratory methods are not yet standardized, and binary detectable-versus-undetectable reporting is rarely sufficient for clinical interpretation. The central translational question is therefore how ctDNA/cfDNA information should be used in realistic HCC surveillance pathways. Current evidence supports these assays as adjunctive molecular risk signals, not as standalone treatment triggers. This review synthesizes the evidence, compares assay strategies, outlines multimodal implementation barriers including standardization and cost, and proposes a cautious roadmap for ctDNA-guided recurrence surveillance in HCC.

Introduction: Hepatocellular carcinoma (HCC) has posed a serious threat to public health worldwide over the past decades. Despite advances in surgery, targeted therapy, and immunotherapy, the prognosis of patients with HCC remains poor. Therefore, more accurate prognostic models are urgently needed. Objective: To explore the relationship between hypoxia and HCC and construct a hypoxia-related gene prognostic model. To predict the overall survival of HCC patients by our model. Methods: Gene set variation analysis (GSVA) was performed using the GSE14520 dataset to identify the Hallmark gene set most strongly associated with the prognosis of HCC patients. A hypoxia-related gene (HRG) signature was then established and validated through multiple bioinformatics approaches. Gene set enrichment analysis was conducted to explore the potential signaling pathways associated with this novel five-gene HRG signature. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess the expression of the five HRGs in HCC patients. Results: GSVA identified the hypoxia Hallmark gene set as the factor most significantly correlated with HCC prognosis. A novel five-gene HRG signature was developed and validated across datasets. The area under the curve values for predicting 1–5-year survival were consistently >0.7. Both the five-gene HRG signature and tumor–node–metastasis (TNM) stage were independent prognostic factors in The Cancer Genome Atlas and GSE14520 cohorts. The Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed enrichment in cell cycle, fatty acid metabolism, and peroxisome proliferator-activated receptor signaling pathways. qRT-PCR results indicated that most HRGs (except Lactate Dehydrogenase A (LDHA)) were differentially expressed between HCC and adjacent normal tissues. Conclusion: We constructed and validated a novel five-gene HRG signature and a prognostic nomogram. Combining this HRG signature with TNM stage improved the accuracy of prognostic prediction for HCC patients.

Background: Cancer-associated fibroblasts (CAFs) and vascular mural cells may shape extracellular matrix organization in colorectal cancer. However, single-cell comparisons are susceptible to unequal cell recovery, ambient RNA, doublets, treatment-stage mixing, and repeated sampling within patients. We investigated fibrovascular remodeling using patients as the inferential unit and distinguished reproducible signals from donor-concentrated and context-dependent findings. Methods: We reanalyzed a published single-cell RNA sequencing cohort of 22 patients, including 20 with colorectal cancer and 2 with duodenal carcinoma. The primary pericyte analysis included 14 pretreatment matched normal-tumor pairs with at least three pericytes per tissue. We assessed ambient contamination and doublets using DecontX and scDblFinder. CAFs were reclustered at six response-blind resolutions, and the stable parent population was tested by patient-blocked pseudobulk analysis after excluding its dominant donor. Independent CRC single-cell and spatial datasets, a cross-cancer immunotherapy cohort, and TCGA were used for external testing. Results: After DecontX correction, tumor pericytes had higher ECM6 scores (median paired change 0.309; false discovery rate [FDR] 0.018). Scores were also higher for the matrix stiffness transcriptional proxy (0.277; FDR 0.012) and the hypoxia/angiogenesis transcriptional program (0.255; FDR 0.028). All three signatures remained significant at the five-pericyte threshold (n=13). COL1A1 and FN1 increased in the analysis, although COL1A1 was borderline in the five-cell sensitivity analysis. Response-blind stability analysis identified a 2,983-cell ECM-remodeling CAF population represented in all 22 patients. After excluding P02, patient-blocked pseudobulk analysis in 15 patients showed higher matrix, inflammatory, and myCAF-related programs and a lower iCAF program. Neither SPP1 nor baseline enrichment in stable disease was supported. In GSE205506, a disjoint 10-gene fibroblast gate retained higher inflammatory and composite CAF scores in non-pCR samples. The highest-scoring unsupervised cluster was donor-concentrated and showed no patient-level association with response. Spatial and cross-cancer analyses yielded mixed or null results. Conclusions: These results support pretreatment fibrovascular transcriptional remodeling at the patient level. They do not establish an SPP1-high response biomarker, a mechanical stiffness phenotype, or causal CAF-to-pericyte signaling. Donor-aware analysis places the rare-cluster observation within a broader, reproducible ECM-remodeling CAF program while defining its evidential limits.