Cancer remains one of the leading causes of mortality and a major barrier to increasing life expectancy worldwide. Liver cancer is the sixth most common cancer and the fourth leading cause of cancer-related deaths globally. The HCC is the most prevalent primary liver cancer, typically associated with poor prognosis. The five-year survival rate after surgery for early-stage HCC ranges between 25% and 50%, but drops below 5% for patients with distant metastases. Despite surgery, approximately 70% of patients experience recurrence or distant metastasis within two years (
30). Chronic infection with HBV or HCV constitutes the primary risk factors for HCC. Globally, over 3% of the population lives with chronic HBV infection, contributing to more than 780,000 deaths annually due to HBV-related complications including fibrosis, cirrhosis, and HCC. Although antiviral therapies reduce the short- and mid-term risk of HCC, they do not eliminate it entirely, emphasizing the importance of early detection of HBV-related HCC to improve survival through timely tumor resection or liver transplantation (
31). Current surveillance strategies, such as ultrasonography and serum AFP measurements every six months, are recommended for at-risk individuals. However, these methods suffer from limited sensitivity in detecting early-stage HCC. Ultrasonography sensitivity diminishes with smaller tumors or in obese patients, while AFP levels may be unreliable due to underlying chronic liver diseases or other malignancies (
32). Hence, there is an urgent need for novel serum biomarkers that can enhance early diagnosis of HBV-related HCC.
The HBV promotes hepatocarcinogenesis via direct and indirect mechanisms. It induces genomic instability, epigenetic remodeling, and aberrant expression of oncogenes and tumor suppressors through viral DNA integration and mutation induction (
33). Simultaneously, chronic HBV infection triggers a persistent inflammatory microenvironment, facilitating immune evasion and disease progression from inflammation to tumor formation. Hepatic fibrosis is a critical step in this cascade, mediated by hematopoietic stem cell activation and differentiation into myofibroblast-like cells via fibrogenic cytokines and growth factors, including the transforming growth factor beta pathway (
34).
The ITGBL1, a secreted glycoprotein structurally similar to β-integrins and containing epidermal growth factor-like repeats, has emerged as a key player in fibrosis and cancer progression. The ITGBL1 promotes tumorigenesis by activating transforming growth factor beta signaling, as demonstrated in ovarian, breast, and gastrointestinal cancers (
3). In HBV-related liver fibrosis and cirrhosis, ITGBL1 expression is significantly elevated, correlating with enhanced HCC cell proliferation, invasion, and metastasis (
2).
Our study confirmed a significant upregulation of ITGBL1 mRNA expression in HBV-related HCC compared to control, HBV-only, and HCC groups without HBV infection (P < 0.01). These findings align with previous reports of increased serum ITGBL1 levels in HBV-HCC patients and its superior diagnostic accuracy compared to AFP for early-stage HBV-HCC detection (
2). Notably, while Ye et al. (
2) observed lower serum ITGBL1 protein in HBV-HCC (
1), our mRNA data showed upregulation, highlighting post-transcriptional mechanisms that may suppress translation in advanced disease stages.
However, our results differ in that ITGBL1 expression was higher in HBV-HCC than in patients with HBV-related liver cirrhosis, suggesting a progressive increase in ITGBL1 expression along the disease spectrum. Similarly, Wang et al. (
35) identified ITGBL1 as a critical gene associated with HBV-related liver fibrosis, showing its positive regulation of hematopoietic stem cell activation through transforming growth factor beta 1 signaling. Our findings further support the notion that elevated ITGBL1 expression may reflect enhanced fibrogenic and oncogenic signaling in HBV-related HCC. Functional studies (
5) demonstrated that ITGBL1 overexpression promotes HCC cell migration and invasion via activation of the transforming growth factor beta/Smads pathway and induction of EMT. Knockdown of ITGBL1 inhibited these malignant behaviors, highlighting its potential as a prognostic biomarker and therapeutic target in HCC. Our study’s observation that ITGBL1 interference suppresses transforming growth factor beta/Smads signaling corroborates this mechanism. Mechanistically, ITGBL1's activation of the transforming growth factor beta/Smads pathway not only drives EMT and fibrosis but also translates to adverse clinical outcomes, such as increased tumor invasiveness and reduced post-resection survival in HBV-HCC patients. This biochemical-clinical nexus underscores ITGBL1's dual role as a molecular driver and prognostic indicator (
36). Elevated ITGBL1 expression further correlates with portal vein tumor thrombosis, a critical predictor of poor prognosis in HCC, as ITGBL1 overexpression enhances vascular invasion via transforming growth factor beta-mediated endothelial remodeling. In HBV-related HCC cohorts, high serum ITGBL1 levels were independently associated with risk of portal vein tumor thrombosis (odds ratio = 2.45, 95% confidence interval: 1.67 - 3.59, P < 0.001), supporting its inclusion in multimodal risk models for early metastasis detection. This link highlights ITGBL1's potential to stratify patients for aggressive interventions, such as transarterial chemoembolization.
Our findings align with emerging evidence that ITGBL1 functions as a key mediator in HBV-related hepatocarcinogenesis through modulation of critical molecular pathways. The ITGBL1 has been shown to activate the transforming growth factor beta/Smads signaling cascade, a central driver of epithelial-to-mesenchymal transition, fibrosis, and tumor progression in HBV-infected livers (
3). This pathway facilitates oncogenic transformation by promoting cellular proliferation, invasion, and metastasis. Emerging evidence highlights the role of microRNAs in HBV-related HCC, complementing the oncogenic and fibrogenic roles of ITGBL1. For instance, microRNA-642a-5p has been shown to suppress HBV-HCC progression by targeting DNA damage-inducible transcript 4, reducing HBV DNA replication, cell proliferation, and invasion, while promoting apoptosis (
37). This microRNA-642a-5p/DNA damage-inducible transcript 4 axis parallels ITGBL1’s regulation of transforming growth factor beta/Smads signaling, suggesting a broader network of molecular interactions that could be leveraged for combined biomarker panels or therapeutic strategies in HBV-HCC.
Furthermore, ITGBL1 is implicated in enhancing tumor angiogenesis through interactions with vascular endothelial growth factor and fibroblast growth factor signaling pathways, which stimulate vascular remodeling and sustain tumor growth (
8). These angiogenic processes are essential for tumor survival and expansion within the hypoxic microenvironment characteristic of HCC. Additionally, recent studies have highlighted the role of HBV in impairing autophagy, a cellular homeostasis mechanism, thereby amplifying oncogenic signaling cascades involving ITGBL1 (
10,
12). The convergence of these pathways suggests a multifaceted role for ITGBL1 in bridging chronic viral infection, fibrogenesis, and tumor microenvironment remodeling.
In addition to the aforementioned pathways, ITGBL1 may play a role in modulating immune responses and autophagy, both of which are critical in the progression of HBV-related HCC. Recent evidence suggests that ITGBL1 can interact with transforming growth factor beta signaling to influence immune checkpoint regulation, potentially facilitating tumor immune evasion and disease progression (
15). Furthermore, dysregulation of autophagy induced by chronic HBV infection may amplify ITGBL1-dependent oncogenic signaling cascades (
10). While these hypotheses require further experimental validation, they indicate a multifaceted role for ITGBL1 in balancing interactions between the virus, host immune system, and key cellular pathways in HCC. Understanding these mechanisms could aid in developing more targeted therapeutic strategies for patients with HBV-associated HCC. Taken together, ITGBL1 emerges as a promising molecular target not only for early detection but also for therapeutic intervention aimed at disrupting the intricate oncogenic and angiogenic networks in HBV-associated HCC.
Our findings, together with recent evidence, suggest that ITGBL1 could serve synergistically with established and emerging biomarkers such as AFP and PSMD12 to enhance diagnostic accuracy for HBV-related HCC. While AFP remains the most widely used serum biomarker, its limited sensitivity, especially in early-stage HCC, restricts its standalone utility. Peng et al. (
17) have identified PSMD12 as a promising molecular regulator with potential diagnostic value in HCC, adding mechanistic depth to biomarker panels. In our study, serum ITGBL1 demonstrated a sensitivity of 64.3% and specificity of 90.4%, outperforming AFP in certain contexts. The complementary diagnostic profiles of ITGBL1, AFP, and PSMD12 imply that their combined use in a multi-biomarker panel could improve early detection rates, reduce false negatives, and better stratify patients for surveillance and treatment. Future large-scale and prospective studies are warranted to validate the clinical performance and cost-effectiveness of such integrated biomarker panels, potentially paving the way for more personalized and timely management of HBV-related HCC.
The synthesized evidence from the systematic review underscores ITGBL1's consistent upregulation across diverse cancers, particularly in gastrointestinal malignancies and HCC, where it correlates with aggressive phenotypes such as EMT, invasion, and metastasis (
3,
21). In HCC, especially HBV-associated cases, elevated serum ITGBL1 mRNA emerges as a promising noninvasive biomarker, outperforming traditional markers such as AFP in specificity, though with moderate sensitivity. This aligns with findings in gastric and colorectal cancers, where ITGBL1's prognostic value is evident through hazard ratios indicating poorer survival and associations with advanced stages (
23,
25,
26).
Our analysis revealed that ITGBL1 expression levels were significantly higher in poorly differentiated HBV-related HCC tumors, suggesting a potential association with more aggressive tumor phenotypes. However, due to the focus on early-stage HCC patients in our cohort, we were unable to comprehensively assess correlations between ITGBL1 expression and tumor metastasis or therapeutic response. Previous studies, such as Huang et al. (
3), have indicated that elevated ITGBL1 may be linked to enhanced tumor invasiveness and resistance to certain therapies, highlighting its possible role in disease progression and treatment outcomes. We acknowledge this limitation in our study and recommend that future research should include larger, longitudinal cohorts to evaluate ITGBL1’s predictive value for metastasis risk and responsiveness to emerging therapeutic modalities, including immune checkpoint inhibitors and targeted treatments. Understanding these associations will be crucial to fully elucidate ITGBL1’s clinical utility as a prognostic biomarker and potential therapeutic target in HBV-related HCC.
Mechanistically, ITGBL1's involvement in transforming growth factor beta/Smads and Wnt/β-catenin pathways explains its role in tumor progression, as corroborated by functional assays showing reduced migration upon knockdown (
22,
24). In non-gastrointestinal cancers such as melanoma and ovarian cancer, ITGBL1 modulates immune evasion and chemoresistance, broadening its oncogenic implications (
27,
28). The RUNX2/ITGBL1 axis in breast cancer further highlights transcriptional regulation contributing to metastasis (
29).
Beyond liver cancer, elevated ITGBL1 expression has been implicated in other gastrointestinal malignancies. Li et al. (
21) reported higher ITGBL1 expression correlating with advanced tumor stage and poorer prognosis in gastric cancer, mediated by EMT and KRAS signaling. Similarly, Qi et al. (
22) showed that ITGBL1 promotes colorectal cancer metastasis through interactions with the Wnt/β-catenin pathway. Du et al. (
38) revealed that in pancreatic cancer, ITGBL1 promotes tumor progression via the transforming growth factor beta/Smad pathway and is transcriptionally repressed by JDP2. These studies collectively suggest that ITGBL1 plays a pivotal role in gastrointestinal cancer pathogenesis and progression.
In conclusion, this study highlights a significant association between ITGBL1 gene expression and HBV-related HCC. Our results indicate that ITGBL1 expression may serve as a valuable diagnostic biomarker with high sensitivity and specificity for early detection of HBV-related HCC. Although our study focused specifically on HBV-related HCC, emerging evidence suggests that ITGBL1 elevation is not unique to this etiology. As reported by Ning et al. (
39), increased ITGBL1 expression has also been observed in HCC cases associated with non-alcoholic fatty liver disease and HCV infection. However, in our cohort, ITGBL1 levels were significantly higher in HBV-HCC compared to non-HBV etiologies, indicating a potentially stronger association with HBV-driven tumorigenesis. This distinction may reflect differences in underlying fibrogenic and oncogenic mechanisms across etiologies.
Given the noninvasive nature of serum sampling, ITGBL1 could provide a reliable tool for monitoring HBV-infected patients and identifying those at risk for HCC development. The ITGBL1's downregulation in HCC offers potential integration with fluorescent imaging for enhanced detection. The ITGBL1-targeting nanobodies could be conjugated to near-infrared activatable probes responsive to HCC-specific enzymes, enabling real-time intraoperative visualization of sub-centimeter lesions with high specificity (
40). This hybrid approach would improve fluorescence-guided resection and reduce recurrence rates. Further large-scale studies are warranted to validate ITGBL1 as a diagnostic and prognostic marker and to explore its therapeutic potential.
In addition to ITGBL1, emerging biomarkers such as PSMD12 and immune-related indices like the neutrophil-to-lymphocyte ratio have shown potential in improving diagnostic accuracy for HBV-related HCC (
17). Our study demonstrated that ITGBL1 possesses high specificity (90.4%) and moderate sensitivity (64.3%), which compares favorably to PSMD12 and the neutrophil-to-lymphocyte ratio reported in recent studies. While ITGBL1 shows promise as a diagnostic biomarker, direct head-to-head comparisons with PSMD12 and immune indices in larger cohorts are needed to validate its clinical utility and determine whether combining these markers could further enhance early detection and patient stratification.
Future research should focus on the molecular biology of liver cancer and comparative analyses among different HBV genotypes to refine biomolecular diagnostic markers. Investigations into tissue structural changes, cellular profiles, and serum biomarker levels across HBV genotypes may deepen understanding of carcinogenesis mechanisms. Moreover, multiethnic cohort studies are essential to evaluate the diagnostic accuracy of ITGBL1-based algorithms globally, ensuring broader clinical applicability. To enhance the generalizability and clinical relevance of our findings, future research should aim to validate ITGBL1 expression patterns and prognostic value using large-scale transcriptomic datasets such as TCGA and Gene Expression Omnibus. These databases provide comprehensive multi-omics profiles across diverse populations and tumor stages, enabling robust cross-validation of biomarker candidates. For example, Huang and Yu (
15) successfully utilized TCGA to confirm ITGBL1 overexpression and its association with poor prognosis in liver cancer. Applying similar bioinformatics analyses in HBV-stratified HCC subgroups could reveal deeper insights into ITGBL1’s expression dynamics, co-regulated gene networks, and potential interactions with clinical variables such as tumor grade, metastasis, and treatment response. Such validation would strengthen the biomarker potential of ITGBL1 and guide its future integration into diagnostic and prognostic frameworks.