C-Met as a Molecular Marker for Esophageal Squamous Cell Carcinoma and Its Association with Clinical Outcome

Prognostic value of c-MET in oesophageal squamous cell carcinoma: a study based on the mRNA expression in TCGA database and a meta-analysis

Objective

This study aims to assess the mesenchymal-epithelial transition factor's (c-MET) prognostic value in oesophageal carcinoma (ESCA) through a meta-analysis and bioinformatics.

Methods

We analysed c-MET expression in ESCA tissues using data from The Cancer Genome Atlas (TCGA) and conducted a meta-analysis to evaluate its association with clinicopathological factors and survival outcomes. The meta-analysis included studies reporting hazard ratios (HRs) and odds ratios (ORs) for survival and metastatic outcomes.

Results

The Cancer Genome Atlas analysis revealed elevated c-MET expression in ESCA, which was significantly correlated with lymph node metastasis, tumour grade and stage, though not with overall survival (OS). In the meta-analysis, 278 publications were identified, and 89 duplicates were removed. After screening, 176 articles were excluded, leaving 13 for full-text review. Of these, 5 studies lacked sufficient survival data, resulting in 8 eligible studies with a total of 1,488 patients. Meta-analysis findings indicated that high c-MET expression was associated with worse OS (HR = 1.54, 95% confidence interval [CI]: 1.17-2.01; p = 0.002), distant metastasis (OR = 1.97, 95% CI: 1.14-3.40; p = 0.02) and advanced stage (OR = 2.23, 95% CI: 1.41-3.53; p = 0.0006).

Conclusion

High c-MET expression is associated with poor prognosis and advanced disease in ESCA, highlighting its potential as a biomarker for risk stratification. Further studies are needed to confirm its prognostic value and explore therapeutic implications.

Therapeutic implications of signaling pathways and tumor microenvironment interactions in esophageal cancer

Esophageal cancer (EC) is significantly influenced by the tumor microenvironment (TME) and altered signaling pathways. Downregulating these pathways in EC is essential for suppressing tumor development, preventing metastasis, and enhancing therapeutic outcomes. This approach can increase tumor sensitivity to treatments, enhance patient outcomes, and inhibit cancer cell proliferation and spread. The TME, comprising cellular and non-cellular elements surrounding the tumor, significantly influences EC's development, course, and treatment responsiveness. Understanding the complex relationships within the TME is crucial for developing successful EC treatments. Immunotherapy is a vital TME treatment for EC. However, the heterogeneity within the TME limits the application of anticancer drugs outside clinical settings. Therefore, identifying reliable microenvironmental biomarkers that can detect therapeutic responses before initiating therapy is crucial. Combining approaches focusing on EC signaling pathways with TME can enhance treatment outcomes. This integrated strategy aims to interfere with essential signaling pathways promoting cancer spread while disrupting factors encouraging tumor development. Unraveling aberrant signaling pathways and TME components can lead to more focused and efficient treatment approaches, identifying specific cellular targets for treatments. Targeting the TME and signaling pathways may reduce metastasis risk by interfering with mechanisms facilitating cancer cell invasion and dissemination. In conclusion, this integrative strategy has significant potential for improving patient outcomes and advancing EC research and therapy. This review discusses the altered signaling pathways and TME in EC, focusing on potential future therapeutics.

Combined treatment with crizotinib and temsirolimus is an effective strategy in mantle cell lymphoma and can overcome acquired resistance to temsirolimus

Constitutive activation of the PI3K/AKT/mTOR-pathway plays an important role in the pathogenesis of mantle cell lymphoma (MCL), leading to approval of the mTOR inhibitor temsirolimus for relapsed or refractory MCL. Yet, despite favorable initial response rates, early relapses under treatment have been observed. Therefore, understanding the underlying mechanisms of temsirolimus resistance and developing strategies to overcome it is highly warranted. Here, we established a new temsirolimus-resistant MCL cell line to evaluate the molecular background of resistance to this drug. Transcriptome profiling and gene set enrichment analysis comparing temsirolimus-sensitive and -resistant cell lines showed significant upregulation of PI3K/AKT/mTor-, RAS signaling- and the RTK-dependent PDGFR-, FGFR-, Met- and ALK-signaling-pathways in the resistant cells. Furthermore, MET, known as important proto-oncogene and mediator of drug resistance, was among the most upregulated genes in the resistant cells. Importantly, Met protein was overexpressed in both, MCL cells with acquired as well as intrinsic temsirolimus resistance, but could not be detected in any of the temsirolimus sensitive ones. Combined pharmacological inhibition of mTOR and Met signaling with temsirolimus and the RTK inhibitor crizotinib significantly restored sensitivity to temsirolimus. Furthermore, this combined treatment proved to be synergistic in all MCL cell lines investigated and was also active in primary MCL cells. In summary, we showed for the first time that overexpression of MET plays an important role for mediating temsirolimus resistance in MCL and combined treatment with temsirolimus and crizotinib is a very promising therapeutic approach for MCL and an effective strategy to overcome temsirolimus resistance.

Targeting MET amplification in Gastro-oesophageal (GO) malignancies and overcoming MET inhibitor resistance: challenges and opportunities

INTRODUCTION

MET, the hepatocyte growth factor receptor is amplified in 8% of gastroesophageal (GO) malignancies and associated with poor prognosis. Therapeutic targeting of MET amplification and MET mutations has the potential to improve outcomes for patients with GO cancers (GOC).

AREAS COVERED

The efficacy of MET inhibition (METi) in preclinical studies has yet to translate into meaningful improvements in the treatment paradigm for unselected GOC. MET amplification has been proposed as a superior modality for patient selection; however even if confirmed, frequency and duration of response to METi are limited by rapid activation of primary and secondary resistance pathways. These observations illustrate the challenges inherent in the application of precision oncology predicated on the theory of oncogenic addiction.

EXPERT OPINION

A standardized definition of MET positivity is critical to enhance patient selection. Early successes targeting the METex14 skipping mutation demonstrate the potent therapeutic effects of METi in a clearly molecularly defined cohort. There is robust preclinical rationale and early-phase data supporting exploitation of immune system interaction with MET. Pragmatic investigation of rational therapeutic combinations based on molecular profiling of both primary and metastatic disease sites with sequential circulating tumor DNA analysis can inform successful clinical development of METi agents in GOC.

Prognostic Value of an Immunohistochemical Signature in Patients With Head and Neck Mucosal Melanoma

Purpose

We aimed to develop a prognostic immunohistochemistry (IHC) signature for patients with head and neck mucosal melanoma (MMHN).

Methods

In total, 190 patients with nonmetastatic MMHN with complete clinical and pathological data before treatment were included in our retrospective study.

Results

We extracted five IHC markers associated with overall survival (OS) and then constructed a signature in the training set (n=116) with the least absolute shrinkage and selection operator (LASSO) regression model. The validation set (n=74) was further built to confirm the prognostic significance of this classifier. We then divided patients into high- and low-risk groups according to the IHC score. In the training set, the 5-year OS rate was 22.0% (95% confidence interval [CI]: 11.2%- 43.2%) for the high-risk group and 54.1% (95% CI: 41.8%-69.9%) for the low-risk group (P<0.001), and in the validation set, the 5-year OS rate was 38.1% (95% CI: 17.9%-81.1%) for the high-risk group and 43.1% (95% CI: 30.0%-61.9%) for the low-risk group (P=0.26). Multivariable analysis revealed that IHC score, T stage, and primary tumor site were independent variables for predicting OS (all P<0.05). We developed a nomogram incorporating clinicopathological risk factors (primary site and T stage) and the IHC score to predict 3-, 5-, and 10-year OS.

Conclusions

A nomogram was generated and confirmed to be of clinical value. Our IHC classifier integrating five IHC markers could help clinicians make decisions and determine optimal treatments for patients with MMHN.

MET overexpression and intratumor heterogeneity in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is among the ten most frequent and deadly cancers, without effective therapies for most patients. More recently, drugs targeting deregulated growth factor signaling receptors have been developed, such as HGF-MET targeted therapy. We assessed MET and HGF genetic alterations and gene and protein expression profiles in ESCC patients from the Brazilian National Cancer Institute and publicly available datasets, as well as the intratumor heterogeneity of the alterations found. Our analyses showed that HGF and MET genetic alterations, both copy number and mutations, are not common in ESCC, affecting 5 and 6% of the cases, respectively. HGF showed a variable mRNA expression profile between datasets, with no alterations (GSE20347), downregulation (GSE45670), and upregulation in ESCC (our dataset and GSE75241). On the other hand, MET was found consistently upregulated in ESCC compared to non-tumor surrounding tissue, with median fold-changes of 5.96 (GSE20347), 3.83 (GSE45670), 6.02 (GSE75241), and 5.0 (our dataset). Among our patients, 84% of the tumors showed at least a two-fold increase in MET expression. This observation was corroborated by protein levels, with 55% of cases exhibiting positivity in 100% of the tumor cells. Intratumor heterogeneity was evaluated in at least four tumor biopsies from five patients and two cases showed a consistent increase in MET expression (at least two-fold) in all tumor samples. Our data suggested that HGF-MET signaling pathway was likely to be overactivated in ESCC, representing a potential therapeutic target, but eligibility for this therapy should consider intratumor heterogeneity.

Near-infrared fluorescence-guided resection of micrometastases derived from esophageal squamous cell carcinoma using a c-Met-targeted probe in a preclinical xenograft model

The postoperative survival of esophageal squamous cell carcinoma (eSCC) is notably hindered by cancer recurrence due to difficulty in identifying occult metastases. Cellular mesenchymal-epithelial transition factor (c-Met), which is highly expressed in different cancers, including eSCC, has become a target for the development of imaging probes and therapeutic antibodies. In this study, we synthesized an optical probe (SHRmAb-IR800) containing a near-infrared fluorescence (NIRF) dye and c-Met antibody, which may help in NIRF-guided resection of micrometastases derived from eSCC. Cellular uptake of SHRmAb-IR800 was assessed by flow cytometry and confocal microscopy. In vivo accumulation of SHRmAb-IR800 and the potential application of NIRF-guided surgery were evaluated in eSCC xenograft tumor models. c-Met expression in human eSCC samples and lymph node metastases (LNMs) was analyzed via immunohistochemistry (IHC). Cellular accumulation of SHRmAb-IR800 was higher in c-Met-positive EC109 eSCC cells than in c-Met-negative A2780 cells. Infusion of SHRmAb-IR800 produced higher fluorescence intensity and a higher tumor-to-background ratio (TBR) than the control probe in EC109 subcutaneous tumors (P < 0.05). The TBRs of orthotopic EC109 tumors and LNMs were 3.01 ± 0.17 and 2.77 ± 0.56, respectively. The sensitivity and specificity of NIRF-guided resection of metastases derived from orthotopic cancers were 92.00% and 89.74%, respectively. IHC results demonstrated positive staining in 97.64% (124/127) of eSCC samples and 91.67% (55/60) of LNMs. Notably, increased c-Met expression was observed in LNMs compared to normal lymph nodes (P < 0.0001). Taken together, the results of this study indicated that SHRmAb-IR800 facilitated the resection of micrometastases of eSCC in the xenograft tumor model. This c-Met-targeted probe possesses translational potential in NIRF-guided surgery due to the high positive rate of c-Met protein in human eSCCs.

Sticking to the Problem: Engineering Adhesion in Molecular Endoscopic Imaging

Cancers of the digestive tract cause nearly one quarter of the cancer deaths worldwide, and nearly half of these are due to cancers of the esophagus and colon. Early detection of cancer significantly increases the rate of survival, and thus it is critical that cancer within these organs is detected early. In this regard, endoscopy is routinely used to screen for transforming/cancerous (i.e. dysplastic to fully cancerous) tissue. Numerous studies have revealed that the biochemistry of the luminal surface of such tissue within the colon and esophagus becomes altered throughout disease progression. Molecular endoscopic imaging (MEI), an emerging technology, seeks to exploit these changes for the early detection of cancer. The general approach for MEI is as follows: the luminal surface of an organ is exposed to molecular ligands, or particulate probes bearing a ligand, cognate to biochemistry unique to pre-cancerous/cancerous tissue. After a wash, the tissue is imaged to determine the presence of the probes. Detection of the probes post-washing suggests pathologic tissue. In the current review we provide a succinct, but extensive, review of ligands and target moieties that could be, or are currently being investigated, as possible cognate chemistries for MEI. This is followed by a review of the biophysics that determines, in large part, the success of a particular MEI design. The work draws an analogy between MEI and the well-advanced field of cell adhesion and provides a road map for engineering MEI to achieve assays that yield highly selective recognition of transforming/cancerous tissue in situ.

Cabozantinib (XL184) and R428 (BGB324) Inhibit the Growth of Esophageal Squamous Cell Carcinoma (ESCC)

Esophageal squamous cell carcinoma (ESCC) is a deadly disease for which no effective targeted therapeutic agent has been approved. Both AXL and c-MET have been reported to be independent prognostic factors for ESCC. Thus, inhibitors of AXL/c-MET might have great potential as targeted therapy for ESCC. In the current study, we evaluated the therapeutic potential of the AXL/c-MET selective inhibitors, R428 and cabozantinib, in cell and mouse xenograft models. We demonstrated that both R428 and cabozantinib significantly inhibited the growth of CE81T and KYSE-70 ESCC cells and showed by wound-healing assay that they both inhibited ESCC cell migration. In the animal model, ESCC xenograft models were established by injecting KYSE-70 cells with Matrigel into the upper back region of NOD-SCID male mice followed by treatment with vehicle control, R428 (50 mg/kg/day), cisplatin (1.0 mg/kg), or cabozantinib (30 mg/kg/day) for the indicated number of days. R428 alone significantly inhibited ESCC tumor growth compared to the vehicle; however, no synergistic effect with cisplatin was observed. Notably, the dramatic efficacy of cabozantinib alone was observed in the mouse xenograft model. Collectively, our study demonstrated that both cabozantinib and R428 inhibit ESCC growth in cell and xenograft models. The results reveal the great potential of using cabozantinib for targeted therapy of ESCC.

Effect of c-Met and CD44v6 Expression in Resistance to Chemotherapy in Esophageal Squamous Cell Carcinoma

BACKGROUND

c-Met relies on CD44v6 for its activation and signaling in several cancer cell lines. However, the correlation of c-Met and CD44v6 expression and its biological significance in esophageal squamous cell carcinoma (ESCC) remains unknown.

METHODS

Expression of c-Met and CD44v6 was examined by immunohistochemistry (IHC) in 147 ESCC specimens. We analyzed the impact of c-Met and CD44v6 expression on clinicopathological parameters, including chemoresistance or prognosis in ESCC.

RESULTS

High expression of c-Met and CD44v6 in cancerous lesions was identified in 49.7% and 50.3% of all patients, respectively. The c-Met-high group comprised more advanced pT and pM stages than the c-Met-low group. In addition, more patients in the c-Met-high group received neoadjuvant chemotherapy (NACT) than the c-Met-low group (64.4% vs. 43.2%, P = 0.010). On the other hand, the CD44v6-high group was associated with more advanced pT/pN stages and a poorer clinical response to NACT (response rate 53.5% vs. 77.8%, P = 0.025) than the CD44v6-low group. Double-positive immunostaining of c-Met and CD44v6 was identified in 28.6% of all cases, and multivariate analysis of overall survival (OS) identified them (hazard ratio 1.79, 95% confidence interval 1.03-3.04, P = 0.038) as independent prognostic factors in addition to pN and pM stage.

CONCLUSIONS

c-Met/CD44v6 were associated with tumor progression or chemoresistance. Double-positive expression of c-Met and CD44v6 negatively impacted patient prognosis in ESCC, implying that c-Met and CD44v6 are candidates for targeted therapy in ESCC.

Molecular landscape of esophageal cancer: implications for early detection and personalized therapy

Esophageal cancer (EC) is one of the most lethal cancers and a public health concern worldwide, owing to late diagnosis and lack of efficient treatment. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are main histopathological subtypes of EC that show striking differences in geographical distribution, possibly due to differences in exposure to risk factors and lifestyles. ESCC and EAC are distinct diseases in terms of cell of origin, epidemiology, and molecular architecture of tumor cells. Past efforts aimed at translating potential molecular candidates into clinical practice proved to be challenging, underscoring the need for identifying novel candidates for early diagnosis and therapy of EC. Several major international efforts have brought about important advances in identifying molecular landscapes of ESCC and EAC toward understanding molecular mechanisms and critical molecular events driving the progression and pathological features of the disease. In our review, we summarize recent advances in the areas of genomics and epigenomics of ESCC and EAC, their mutational signatures and immunotherapy. We also discuss implications of recent advances in characterizing the genome and epigenome of EC for the discovery of diagnostic/prognostic biomarkers and development of new targets for personalized treatment and prevention.

c-MET expression potentially contributes to the poor prognosis of rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is one of the most common soft-tissue sarcomas with a poor prognosis. c-MET is a prognostic biomarker associated with growth, proliferation, invasion, and metastasis in various carcinomas. In this study, we aim to investigate the expression of c-MET in RMS and its effect on the prognosis of patients with rhabdomyosarcoma. We performed immunohistochemistry and a quantitative real-time polymerase chain reaction (qRT-PCR) to determine the expression levels of c-MET proteins and mRNAs. Results indicated that the c-MET protein and mRNA expression levels in the RMS samples were significantly higher than those in normal controls (P<0.01 and P=0.0492). However, the correlation between c-MET expression and any other clinicopathological parameter and survival was not significant (P=0.837). Nevertheless, c-MET expression had a significant influence on the overall survival rates of patients with ERMS (χ²=9.673, P=0.002) and fusion gene-negative patients (χ²=5.400, P=0.020). These findings suggest that c-MET may serve as a promising biomarker capable of predicting poor prognosis in patients with RMS.

Tissue protein biomarker candidates to predict progression of esophageal squamous cell carcinoma and precancerous lesions

Esophageal squamous cell carcinoma (ESCC) is one of the most predominant malignancies worldwide. The 5-year survival rate is still relatively low due to few symptoms presenting with the early disease, diagnosis at middle to late stage, and high risk of recurrence after therapy. Novel protein biomarkers for early detection and treatment of ESCC have the potential to reduce incidence and mortality rates, and significantly prolong the 5-year survival rate. To date, several ESCC biomarkers are being investigated for screening, diagnosis, and treatment to decrease the disease burden. This review summarizes recent developments in candidate protein biomarkers for early diagnosis, predictors for precancerous disease progression, and prognosis of ESCC. Protein biomarkers that enable identification of the different pathologic grades of ESCC will need to be identified. ESCC biomarkers have the potential to improve screening and treatment strategies; multicenter prospective studies with large sample sizes will be required to confirm the usefulness of these candidate biomarkers.

Prognostic value of an immunohistochemical signature in patients with esophageal squamous cell carcinoma undergoing radical esophagectomy

Here, we aimed to identify an immunohistochemical (IHC)‐based classifier as a prognostic factor in patients with esophageal squamous cell carcinoma (ESCC). A cohort of 235 patients with ESCC undergoing radical esophagectomy (with complete clinical and pathological information) were enrolled in the study. Using the least absolute shrinkage and selection operator (LASSO) regression model, we extracted six IHC features associated with progression‐free survival (PFS) and then built a classifier in the discovery cohort (n = 141). The prognostic value of this classifier was further confirmed in the validation cohort (n = 94). Additionally, we developed a nomogram integrating the IHC‐based classifier to predict the PFS. We used the IHC‐based classifier to stratify patients into high‐ and low‐risk groups. In the discovery cohort, 5‐year PFS was 22.4% (95% CI: 0.14–0.36) for the high‐risk group and 43.3% (95% CI: 0.32–0.58) for the low‐risk group (P = 0.00064), and in the validation cohort, 5‐year PFS was 20.58% (95% CI: 0.12–0.36) for the high‐risk group and 36.43% (95% CI: 0.22–0.60) for the low‐risk group (P = 0.0082). Multivariable analysis demonstrated that the IHC‐based classifier was an independent prognostic factor for predicting PFS of patients with ESCC. We further developed a nomogram integrating the IHC‐based classifier and clinicopathological risk factors (gender, American Joint Committee on Cancer staging, and vascular invasion status) to predict the 3‐ and 5‐year PFS. The performance of the nomogram was evaluated and proved to be clinically useful. Our 6‐IHC marker‐based classifier is a reliable prognostic tool to facilitate the individual management of patients with ESCC after radical esophagectomy.

Large-scale comprehensive immunohistochemical biomarker analyses in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a heterogeneous disease in the sense that the biological behavior is regulated by the activation of various signaling pathways. The aim of this study was to investigate the relationships between the expressions of various targetable proteins and the clinicopathological characteristics of ESCC patients.

METHODS

A total of 286 patients with ESCC who had undergone curative surgical resection without neoadjuvant therapy were enrolled in this study. The protein expressions of EGFR, HER2, MET, IGF1R, FGFR2, p53, and PD-L1 were immunohistochemically evaluated in a tissue microarray analysis. The relationships between the expression statuses of each of the above molecules, and the PD-L1 expression status as well as the clinicopathological characteristics, including the survival outcome were assessed.

RESULTS

The expression frequencies of EGFR, HER2, MET, IGF1R, FGFR2, p53, and PD-L1 were as follows: 90.9, 1.0, 2.4, 71.0, 16.1, 62.9 and 23.4%. The overlapping expressions of two or more receptor tyrosine kinases were observed in 72.0%. MET expression was the only poor prognostic factor of recurrence-free survival [hazard ratio (HR) 1.89, 95% confidence interval (CI) 1.15-3.11]; in contrast, PD-L1 was the only favorable prognostic factor for both recurrence-free survival (HR 0.57, 95% CI 0.38-0.87) and overall survival (HR 0.56, 95% CI 0.35-0.89). No correlation was observed between the expressions of PD-L1 and the other molecules.

CONCLUSIONS

This large cohort study demonstrated that multiple molecules were co-expressed in most of the ESCC cases, suggesting that combining molecular targeted agents for these co-expressed molecules should be considered.

A Phase II Study of the c-Met Inhibitor Tivantinib in Combination with FOLFOX for the Treatment of Patients with Previously Untreated Metastatic Adenocarcinoma of the Distal Esophagus, Gastroesophageal Junction, or Stomach

BACKGROUND

This phase I/II study was designed to determine the maximum tolerated dose of tivantinib in combination with standard dose FOLFOX for the treatment of patients with advanced solid tumors and to evaluate the safety and efficacy of this combination for patients with previously untreated metastatic adenocarcinoma of the distal esophagus, gastroesophageal (GE) junction, or stomach.

METHODS

Patients with advanced solid tumors for which FOLFOX would be appropriate chemotherapy received escalating doses of tivantinib BID (days 1-14) in a standard 3 + 3 design in phase I. In phase II, patients with advanced GE cancer received standard FOLFOX day 1 and tivantinib (360 mg PO BID) days 1-14 of each 2-week cycle. Restaging occurred every four cycles. The primary phase II endpoint was response rate (RR).

RESULTS

Forty-nine patients were enrolled (15 on phase I and 34 on phase II). The expansion dose was established as tivantinib 360 mg BID in combination with FOLFOX. Thirty-two phase II patients were treated for a median of eight cycles (range, 1-38), with an overall RR of 38%. Treatment-related toxicities included neutropenia, fatigue, diarrhea, nausea, and peripheral neuropathy. Median progression-free survival (PFS) was 6.1 hmonths with a median time to progression of 7.0 months. Median overall survival was 9.6 months. Two patients remain on study at the time of this analysis.

CONCLUSIONS

The combination treatment of tivantinib plus FOLFOX in patients with advanced GE cancer showed a response and PFS in the range of historical controls for first-line FOLFOX therapy. However, two patients had extended time on study treatment (36 and 45 cycles) at the time of data cutoff.

Suppression of osteopontin inhibits chemically induced hepatic carcinogenesis by induction of apoptosis in mice

Previous clinical reports have found elevated osteopontin (OPN) levels in tumor tissues to be indicative of greater malignancy in human hepatocellular carcinoma (HCC). However, the role of OPN on carcinogenesis and its underlying mechanism remain unclear. In the present study, we investigated the oncogenic role of OPN in diethylnitrosamine (DEN)-induced hepatic carcinogenesis in mice. The overall incidence of hepatic tumors at 36 weeks was significantly lower in OPN knockout (KO) mice than in wild-type (WT) mice. Apoptosis was significantly enhanced in OPN KO mice, and was accompanied by the downregulation of epidermal growth factor receptor (EGFR). In the in vitro study, OPN suppression also led to lower mRNA and protein levels of EGFR associated with the downregulation of c-Jun in Hep3B and Huh7 human HCC cells lines, which resulted in increased apoptotic cell death in both cell lines. Moreover, a positive correlation was clearly identified between the expression of OPN and EGFR in human HCC tissues. These data demonstrate that the OPN deficiency reduced the incidence of chemically induced HCC by suppressing EGFR-mediated anti-apoptotic signaling. An important implication of our findings is that OPN positively contributes to hepatic carcinogenesis.