Mesenchymal stem cells seldomly fuse with hepatocellular carcinoma cells and are mainly distributed in the tumor stroma in mouse models

Mesenchymal stem cells (MSCs) can have an effect on the growth and metastasis of human malignancies, including hepatocellular carcinoma (HCC); however, their mechanisms of action are not yet fully understood. The cell fusion of stem cell derived from bone marrow with other cells has been increasingly emphasized. The purpose of this study was to investigate the distribution of MSCs in mouse models of HCC, as well as the cell fusion between MSCs and HCC cells. We labeled HCC cells and MSCs with green fluorescence protein (GFP), red fluorescence protein (RFP), 4',6-diamidino-2-phenylindole (DAPI) and 5-bromo-2'-deoxyuridine (BrdU). We found that MSCs fused with HCC cells at a low frequency in vitro. MSCs were found to be merged into HCC tissues after intravenous injection, and compared with the mice not injected with MSCs, the MSCs were mainly distributed in the tumor stroma; Following the injection of the MSCs, the tumor stroma was found to have expanded in size, and the rate of pulmonary metastasis in the MSC-injected group was significantly lower (20%) compared to that in the group not injected with MSCs (100%, P=0.01). These data suggest that cell fusion between MSCs and HCC after engraftment is not one of the main mechanisms of action of the MSCs, while stromal differentiation is a major mechanism of action of the MSCs, leading to the inhibition of the pulmonary metastasis of HCC.

Hepatitis B virus and hepatitis C virus play different prognostic roles in intrahepatic cholangiocarcinoma: A meta-analysis

AIM: To identify the prognostic value of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in patients with intrahepatic cholangiocarcinoma.

METHODS: A search was performed for relevant publications in PubMed, EMBASE and Web of Science databases. The pooled effects were calculated from the available information to identify the relationship between HBV or HCV infection and the prognosis and clinicopathological features. The χ² and I² tests were used to evaluate heterogeneity between studies. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated by a fixed-effects model, if no heterogeneity existed. If there was heterogeneity, a random-effects model was applied.

RESULTS: In total, 14 studies involving 2842 cases were enrolled in this meta-analysis. The patients with HBV infection presented better overall and disease-free survival, and the pooled HRs were significant at 0.76 (95%CI: 0.70-0.83) and 0.78 (95%CI: 0.66-0.94), respectively. Additionally, our study revealed that HCV infection was correlated with shortened overall survival in comparison with the control group (HR = 2.64, 95%CI: 1.77-3.93). We also found that HBV infection occurred more frequently in male patients [odds ratio (OR) = 1.91, 95%CI: 1.06-3.44] and was correlated with higher levels of serum aspartate transaminase (AST) and alpha-fetoprotein (AFP) (OR = 1.93, 95%CI: 1.11-3.35; OR = 3.86, 95%CI: 2.58-5.78) and a lower level of serum carbohydrate antigen 19-9 (CA19-9) (OR = 0.47, 95%CI: 0.34-0.65). Moreover, HBV infection was associated with cirrhosis (OR = 6.44, 95%CI: 4.33-9.56), a higher proportion of capsule formation (OR = 6.04, 95%CI: 3.56-10.26), and a lower rate of lymph node metastasis (OR = 0.39, 95%CI: 0.25-0.58). No significant publication bias was seen in any of the enrolled studies.

CONCLUSION: HBV infection may indicate a favorable prognosis in patients with intrahepatic cholangiocarcinoma, while HCV infection suggests a poor prognosis.

Prospero-related homeobox 1 drives angiogenesis of hepatocellular carcinoma through selectively activating interleukin-8 expression

Angiogenesis has been proven to play an important role in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanism underlying HCC angiogenesis is not well understood. In this study, Prospero-related homeobox 1 (PROX1) was identified as a novel proangiogenic factor in HCC cell lines and tissues. A strong positive correlation was found between the levels of PROX1 and microvessel density in HCC tissues. Knockdown of PROX1 expression in HCC cells significantly inhibited the in vitro capillary tube formation by human vascular endothelial cells and in vivo angiogenesis of HCC, while overexpression of PROX1 in HCC cells induced the opposite effects. PROX1 and nuclear factor κB p65 expression levels were positively correlated in both HCC tissues and cell lines. PROX1 enhances the nuclear accumulation of p65 and stabilizes p65 by recruiting ubiquitin-specific protease 7 to prevent p65 ubiquitination. Consequently, PROX1 activated nuclear factor κB signaling and selectively promoted expression of the proangiogenic interleukin-8 (IL-8) by epigenetically stimulating the IL-8 promoter. Finally, progression of high PROX1 expression HCC in tumor xenograft mice could be effectively contained by an anti-IL-8 monoclonal antibody.

CONCLUSIONS

We have identified PROX1 as a crucial promoter of HCC angiogenesis; our study provides an insight into PROX1's function in HCC progression and the potential therapeutic application of anti-IL-8 antibody in high PROX1 expression HCC patients. (Hepatology 2017;66:1894-1909).

Driver mutations of intrahepatic cholangiocarcinoma shape clinically relevant genomic clusters with distinct molecular features and therapeutic vulnerabilities

Purpose: To establish a clinically applicable genomic clustering system, we investigated the interactive landscape of driver mutations in intrahepatic cholangiocarcinoma (ICC).

Methods: The genomic data of 1481 ICCs from diverse populations was analyzed to investigate the pair-wise co-occurrences or mutual exclusivities among recurrent driver mutations. Clinicopathological features and outcomes were compared among different clusters. Gene expression and DNA methylation profiling datasets were analyzed to investigate the molecular distinctions among mutational clusters. ICC cell lines with different gene mutation backgrounds were used to evaluate the cluster specific biological behaviors and drug sensitivities.

Results: Statistically significant mutation-pairs were identified across 21 combinations of genes. Seven most recurrent driver mutations (TP53, KRAS, SMAD4, IDH1/2, FGFR2-fus and BAP1) showed pair-wise co-occurrences or mutual exclusivities and could aggregate into three genetic clusters: Cluster1: represented by tripartite interaction of KRAS, TP53 and SMAD4 mutations, exhibited large bile duct histological phenotype with high CA19-9 level and dismal prognosis; Cluster2: co-association of IDH/BAP1 or FGFR2-fus/BAP1 mutation, was characterized by small bile duct phenotype, low CA19-9 level and optimal prognosis; Cluster3: mutation-free ICC cases with intermediate clinicopathological features. These clusters showed distinct molecular traits, biological behaviors and responses to therapeutic drugs. Finally, we identified S100P and KRT17 as “cluster-specific”, “lineage-dictating” and “prognosis-related” biomarkers, which in combination with CA19-9 could well stratify Cluster3 ICCs into two biologically and clinically distinct subtypes.

Conclusions: This clinically applicable clustering system can be instructive to ICC prognostic stratification, molecular classification, and therapeutic optimization.

The prognostic significance of preoperative plasma levels of osteopontin in patients with TNM stage-I of hepatocellular carcinoma

PURPOSE

To evaluate the prognostic value of preoperative plasma osteopontin (OPN) levels in patients with early stage of hepatocellular carcinoma (HCC).

METHODS

Preoperative plasma levels of OPN were detected by ELISA in 68 patients with tumor-node metastasis system stage-I of HBV-related HCC, and their association with tumor recurrence or patients' survival was analyzed.

RESULTS

The median plasma OPN level of patients was 82.51 ng/ml (25–75% interquartile range, 63.15–110.45 ng/ml). Plasma OPN levels in patients with tumor size C5 cm in diameter were significantly higher than that of patients with tumor size\5 cm in diameter (104.76 vs.75.16 ng/ml, P = 0.003). When the 100 ng/ml was used asa cut-off value to divide the patients into two groups: the higher plasma OPN group and the lower plasma OPN group, the tumor recurrence rate of the higher plasma OPN group was significantly higher than that of the lower plasma OPN group (52.17 vs. 24.44%, P = 0.022). Meanwhile, the recurrence rate of the patients with positive alpha fetoprotein (AFP) (45.5%) was significantly higher than that of those negative AFP patients (12.5%,P = 0.006). A higher plasma OPN level was one leading independent prognostic factor for both overall survival(OS) and relapse-free survival in multivariate Cox models.

CONCLUSION

The preoperative plasma OPN level and serum AFP level in patients with early stage of HCC can be used as a prognostic marker for early stage of HCC.

RA190, a Proteasome Subunit ADRM1 Inhibitor, Suppresses Intrahepatic Cholangiocarcinoma by Inducing NF-KB-Mediated Cell Apoptosis

BACKGROUND/AIMS

Effective drug treatment for intrahepatic cholangiocarcinoma (ICC) is currently lacking. Therefore, there is an urgent need for new targets and new drugs that can prolong patient survival. Recently targeting the ubiquitin proteasome pathway has become an attractive anti-cancer strategy. In this study, we aimed to evaluate the therapeutic effect of and identify the potential mechanisms involved in targeting the proteasome subunit ADRM1 for ICC.

METHODS

The expression of ADRM1 and its prognostic value in ICC was analyzed using GEO and TCGA datasets, tumor tissues, and tumor tissue arrays. The effects of RA190 on the proliferation and survival of both established ICC cell lines and primary ICC cells were examined in vitro. Annexin V/propidium iodide staining, western blotting and immunohistochemical staining were performed. The in vivo anti-tumor effect of RA190 on ICC was validated in subcutaneous xenograft and patient-derived xenograft (PDX) models.

RESULTS

ADRM1 levels were significantly higher in ICC tissues than in normal bile duct tissues. ICC patients with high ADRM1 levels had worse overall survival (hazard ratio [HR] = 2.383, 95% confidence interval [CI] =1.357 to 4.188) and recurrence-free survival (HR = 1.710, 95% CI =1.045 to 2.796). ADRM1 knockdown significantly inhibited ICC growth in vitro and in vivo. The specific inhibitor RA190 targeting ADRM1 suppressed proliferation and reduced cell vitality of ICC cell lines and primary ICC cells significantly in vitro. Furthermore, RA190 significantly inhibited the proteasome by inactivating ADRM1, and the consequent accumulation of ADRM1 substrates decreased the activating levels of NF-κB to aggravate cell apoptosis. The therapeutic benefits of RA190 treatment were further demonstrated in both subcutaneous implantation and PDX models.

CONCLUSIONS

Our findings indicate that up-regulated ADRM1 was involved in ICC progression and suggest the potential clinical application of ADRM1 inhibitors (e.g., RA190 and KDT-11) for ICC treatment.

Postoperative serum osteopontin level is a novel monitor for treatment response and tumor recurrence after resection of hepatitis B-related hepatocellular carcinoma

BACKGROUND

Presurgery serum osteopontin (OPN) level has been demonstrated to correlate to tumor recurrence and survival of hepatocellular carcinoma (HCC) patients. This study investigated the postoperative dynamic changes of serum OPN level and its clinical significance in HCC patients.

METHODS

Presurgery serum OPN levels were measured by enzyme-linked immunosorbent assay in cohort A of 179 HCC patients and were compared with the multiple controls including different kinds of liver diseases and healthy individuals. In cohort B of 110 patients with resectable HCCs, besides preoperative assays, serum OPN was monitored at 1 week, 1, and ≥2 months after operation.

RESULTS

The baseline presurgery serum OPN of HCC patients was significantly higher than that of the patients with the other kinds of liver diseases (p < 0.0001). The prognostic values of presurgery serum OPN level in HCC patients were further confirmed. The postsurgery OPN levels were significantly elevated within 1 week after HCC resection, then decreased at 1 month and reached the nadir later than 2 months after operations. It increased again at the time of tumor recurrence, then declined after the second removal of recurrent HCCs. Moreover, postoperative OPN in α-fetoprotein-negative and -positive HCC patients had the same changing pattern; it only correlated to liver function and C-reactive protein level.

CONCLUSIONS

After a transient fluctuation, serum OPN levels significantly decrease after curative resection of HCCs. Postoperative serum OPN could serve as a surrogate serologic biomarker for monitoring treatment response and tumor recurrence after HCC resection, including α-fetoprotein-negative ones.

Cholesterol suppresses GOLM1-dependent selective autophagy of RTKs in hepatocellular carcinoma

Aberrant activation of receptor tyrosine kinases (RTKs) and the subsequent metabolic reprogramming play critical roles in cancer progression. Our previous study has shown that Golgi membrane protein 1 (GOLM1) promotes hepatocellular carcinoma (HCC) metastasis by enhancing the recycling of RTKs. However, how this RTK recycling process is regulated and coupled with RTK degradation remains poorly defined. Here, we demonstrate that cholesterol suppresses the autophagic degradation of RTKs in a GOLM1-dependent manner. Further mechanistic studies reveal that GOLM1 mediates the selective autophagy of RTKs by interacting with LC3 through an LC3-interacting region (LIR), which is regulated by a cholesterol-mTORC1 axis. Lowering cholesterol by statins improves the efficacy of multiple tyrosine kinase inhibitors (TKIs) in vivo. Our findings indicate that cholesterol serves as a signal to switch GOLM1-RTK degradation to GOLM1-RTK recycling and suggest that lowering cholesterol by statin may be a promising combination strategy to improve the TKI efficiency in HCC.

CXCR6 predicts poor prognosis in gastric cancer and promotes tumor metastasis through epithelial-mesenchymal transition

Chemokines and their receptors have been confirmed to be involved in several types of cancer. However, little is known concerning the role of CXCL16 and its receptor CXCR6 in gastric cancer (GC) progression and metastasis. In the present study, expression of CXCL16 and CXCR6 in GC tumor and peritumoral tissues was detected by immunohistochemistry (IHC) in a cohort of 352 GC patients who underwent gastrectomy, and the correlation between CXCL16/CXCR6 expression and clinicopathological characteristics was further analyzed. To evaluate the function of CXCR6, we overexpressed and knocked down CXCR6 in GC cell lines. Results showed that expression of CXCR6, but not CXCL16, was significantly upregulated in GC tumor tissues, and was significantly correlated with lymph node and distant metastases, and advanced clinical stage in the GC patients. Survival analysis showed that large tumor size (>5 cm), elevated preoperative serum carcinoembryonic antigen (CEA) level, advanced TNM stage and high CXCR6 expression indicated worse overall survival (OS) and disease-free survival (DFS) in GC, and CXCR6 was an independent predictor for both OS and DFS in GC. In vitro experiments showed that CXCR6 overexpression induced cell migration and invasion ability, and promoted epithelial-mesenchymal transition of GC cells by upregulation of mesenchymal markers and inhibition of epithelial markers. In contrast, knockdown of CXCR6 in GC cells resulted in inhibition of cell proliferation, migration and invasion ability, and reversal of epithelial-mesenchymal transition (EMT) phenomenon. Our results demonstrated that CXCR6 is an independent prognostic factor for poor survival in GC patients, and may promote GC metastasis through EMT.

Correlation and prognostic value of osteopontin and Bcl-2 in hepatocellular carcinoma patients after curative resection

Osteopontin (OPN) may facilitate tumorigenesis and metastasis through prevention of tumor cells from apoptosis. Although previous studies have suggested involvement of enhanced Bcl-2 protein family expression, the role of OPN together with Bcl-2 in hepatocellular carcinoma (HCC) remains unknown. In this study, we used western blotting to detect the OPN and Bcl-2 expression levels in cell lines with different OPN backgrounds and HCC tissues, and tumor tissue microarrays to examine OPN and Bcl-2 expression levels in 454 HCC cases. The Kaplan-Meier method and log-rank test were applied to investigate the predictive values of OPN and Bcl-2 in HCC patients. In vitro assays indicated that OPN expression increased concordantly with increasing metastatic potential in MHCC97-H, MHCC97-L, HepG2 and SMMC-7721 cell lines by western blotting, whereas Bcl-2 expression declined. In addition, Bcl-2 was highly upregulated in OPN knockdown MHCC97-H cell lines. Furthermore, in HCC tissues, it was confirmed that OPN levels were also significantly higher in recurrent tumor tissues compared to non-recurrent tissues by western blotting (p<0.001), whereas the contrary occurred in Bcl-2 (p=0.046). Using immunohistochemistry analysis, patients with higher OPN levels had significantly shorter median survival time and recurrence time compared to the lower ones, although the opposite occurred in Bcl-2 levels. Of note, when OPN and Bcl-2 were combined, we found that the co-index of OPN/Bcl-2 was an independent prognostic factor for both overall survival (p<0.001) and time to recurrence (p<0.001). Our findings demonstrate that OPN/Bcl-2 expression is a promising independent predictor of recurrence and survival in HCC. Additionally, Bcl-2 levels may be regulated by OPN in the HCC microenvironment.

Association of specific genotypes in metastatic suppressor HTPAP with tumor metastasis and clinical prognosis in hepatocellular carcinoma

The phosphatidic acid phosphatase HTPAP has been defined as a metastatic suppressor of hepatocellular carcinoma (HCC), but little is known about its function or potential applications as a prognostic marker. In this study, we analyzed patterns of HTPAP genetic variation and gene expression in 864 patients who underwent HCC resection, assessing these patterns for correlations to tumor metastasis potential. Focusing on two tagSNPs that were selected (+357G/C and +1838A/G), we found that only the +357G/C genotype was significantly associated with HTPAP mRNA and protein expression levels and the probability of metastasis. In an independent cohort of 665 HCC patients, we determined that the +357G/C genotype was associated with shorter time to recurrence and overall survival. Together, these results indicated that the HTPAP tagSNP +357 GG+GC genotypes may influence HCC metastatic potential and clinical prognosis by down-regulating HTPAP expression. Extending these results, a global expression profiling analysis identified 41 genes including the pro-inflammatory genes IL-8 and TLR2 that were significantly overexpressed in the +357 GG+GC group, as possible coregulated markers with HTPAP. Together, our findings identify an HTPAP genotype and associated gene expression pattern that favors metastasis progression and that could be used to predict tumor metastasis and prognosis in HCC patients.

Bcl-2 expression is a poor predictor for hepatocellular carcinoma prognosis of andropause-age patients

OBJECTIVE

The expression of B-cell lymphoma 2 (Bcl-2) seems to be influenced by the endocrine environment. Numerous reports demonstrate the diverse expression of Bcl-2 family members under sex steroid regulation. With the exception of estrogen-related tumors, androgen-related tumors have shown their characteristics in Bcl-2 expression. In this study, the status of Bcl-2 expression in male hepatocellular carcinoma (HCC) patients was examined to verify the high incidence of HCC in males.

METHODS

Tumor tissue microarray was used to examine Bcl-2 expression levels in 374 HCC cases including 306 males and 68 females. Kaplan-Meier method, log-rank test, and Cox proportional hazards model were applied to investigate the predictive value of Bcl-2 in HCC patients.

RESULTS

Immunohistochemistry analysis showed that male patients with higher Bcl-2 levels had significantly longer median survival time and recurrence time than those with lower levels. However, no significant differences in outcomes were found between different Bcl-2 levels in female patients. When the male patients were stratified into several age points, the level of Bcl-2 expression showed poorer predictive efficiency in the 45-49 and 55-60 age groups in andropause-age patients compared with other age groups. Bcl-2 was an independent prognostic factor for both overall survival (P < 0.0001) and recurrence time (P = 0.0001) in male patients. After excluding male patients in the 45-60 age group, the predictive efficiency was enhanced (n = 147, OS, P = 0.0002, TTR, P < 0.0001).

CONCLUSIONS

Bcl-2 expression is an independent predictor of survival and recurrence in male HCC. Bcl-2 levels may also be regulated by androgens or androgen receptors in male HCC patients. Bcl-2 levels change and exhibit poor predictive efficiency when androgen levels vary dramatically (andropause age).

Advance in metabolism and target therapy in breast cancer stem cells

Breast cancer, like many other cancers, is believed to be driven by a population of cells that display stem cell properties. Recent studies suggest that cancer stem cells (CSCs) are essential for tumor progression, and tumor relapse is thought to be caused by the presence of these cells. CSC-targeted therapies have also been proposed to overcome therapeutic resistance in breast cancer after the traditional therapies. Additionally, the metabolic properties of cancer cells differ markedly from those of normal cells. The efficacy of metabolic targeted therapy has been shown to enhance anti-cancer treatment or overcome therapeutic resistance of breast cancer cells. Metabolic targeting of breast CSCs (BCSCs) may be a very effective strategy for anti-cancer treatment of breast cancer cells. Thus, in this review, we focus on discussing the studies involving metabolism and targeted therapy in BCSCs.

Properties and feasibility of using cancer stem cells in clinical cancer treatment

Cancer treatment failure, drug resistance, or metastatic recurrence are thought to be caused mainly by the existence of a very small number of cancer stem cells (CSCs). The characteristics of this subgroup of cells include self-renewal, tumorigenesis, multiple differentiation and high invasiveness, metastasis, and drug resistance potential. Many studies have demonstrated that CSCs play important roles in tumor growth, spread and metastatic relapse after treatment, and are closely related to the prognosis of patients. From a therapeutic viewpoint, deep insights into the CSCs biology, development of specific therapeutic strategies for targeting CSCs, and characterization of their microenvironment could be an ideal way to combat cancer.

Downregulation of HTPAP transcript variant 1 correlates with tumor metastasis and poor survival in patients with hepatocellular carcinoma

Our previous study has identified HTPAP as a novel metastasis suppressor from chromosome 8p which is often deleted in metastatic HCC. We sought to further evaluate the expression levels of transcript variants of HTPAP (HTPAP-1, HTPAP-2 and HTPAP-3) in 67 HCC tumor tissues and 11 normal liver tissues by RT-PCR with specific TaqMan probes and primer sets, and explore their association with HCC metastasis and survival. We found that the expression levels of three HTPAP transcript variants were quite different in HCCs. Only HTPAP-1 was found to be significantly associated with HCC metastasis (P=0.00053), overall survival (P=0.0023) and time to recurrence (P=0.010) of HCC. Patients with a lower expression of HTPAP-1 were inclined to accompany intrahepatic metastases and tumor thrombi (P<0.05) and had a poor prognosis. In vitro, three fusion pEGFP-N1 vectors encoding HTPAP-1, HTPAP-2 and HTPAP-3 were introduced into HCC cells respectively to track HTPAPs' expressions and identify their function. We found overexpression of HTPAP-1 conferred HCC cells reduced ability of invasion without significant impact on cell proliferation, and also displayed a distinct cell location on cell membrane and in cytoplasm, which were different from two other variants. Consequently, HTPAP-1 may be the transcript of HTPAP to exhibit a suppressive role on HCC metastasis, and can be a prognostic marker for HCC.

Abstract 1058: Mutations in isocitrate dehydrogenase 1 and 2 are associated with DNA hypermethylation in intrahepatic cholangiocarcinomas

Cholangiocarcinomas are rare but aggressive cancers, with an increasing incidence and a dismal 5-year survival rate of less than 5%. Mutations in the genes encoding isocitrate dehydrogenase, IDH1 and IDH2, have been reported in ∼70% of gliomas, ∼20% of myeloid leukemias, ∼56% of chondrosarcomas, and ∼10% of melanomas. We discovered IDH1 and IDH2 mutations in 29 of 305 (9%) intrahepatic cholangiocarcinomas. Tumors with mutations in IDH1 or IDH2 had lower 5-hydroxymethylcytosine and higher 5-methylcytosine levels, as well as increased dimethylation of histone H3K79. Mutations in IDH1 or IDH2 were independently associated with longer time to recurrence of cholangiocarcinoma in multivariate analysis (p = 0.046). We identified 2,267 genes that were significantly hypermethylated in tumors with mutations in IDH1 or IDH2. Hypermethylated CpG sites were significantly enriched in CpG shores and in the 1500 bp upstream of annotated transcription start sites, suggesting a global regulation of transcriptional potential. Gene expression profiling of 7 IDH1/2-mutant and 20 IDH1/2-wildtype tumors revealed increased expression of citric acid cycle and oxidative phosphorylation enzymes, as well as decreased expression of cytoskeleton organization genes. Integrated analyses of DNA methylation and gene expression identified interleukin-6 and several of its downstream targets as candidates for silencing by DNA methylation. Conclusions: Cholangiocarcinomas with mutations in IDH1 or IDH2 represent a molecular subclass with distinct signaling pathway alterations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1058. doi:1538-7445.AM2012-1058

Genomic aberrations in the HTPAP promoter affect tumor metastasis and clinical prognosis of hepatocellular carcinoma

We previously reported that the intronic tagSNP +357G/C in the metastasis suppressor HTPAP is associated with metastasis and prognosis of hepatocellular carcinoma (HCC). The aim of this study was to investigate whether SNPs in the HTPAP promoter modulate HTPAP expression and prognosis of HCC. Genomic DNA from 572 microdissected HCCs were genotyped by pyrosequencing and verified by direct sequencing. Haplotype blocks were analyzed. Reporter plasmids were constructed and transfected into HCC cell lines. Transcriptional activities of plasmids were analyzed by dual-luciferase reporter systems. HTPAP expression was measured by real-time quantitative PCR, western blots, and tissue microarrays. Invasion was assessed by Matrigel assays. The prognostic values of HTPAP promoter SNPs in HCC were evaluated by Kaplan-Meier and Cox regression analyses. We identified six SNPs, including -1053A/G and +64G/C, in the HTPAP promoter. The SNPs were in complete linkage disequilibrium, resulting in three promoter haplotypes (promoter I:-1053AA/+64GG, promoter II: -1053AG/+64GC, and promoter III: -1053GG/+64CC). Promoter I manifested the highest luciferase index (p<0.005). However, no significant difference was observed between promoters II and III. We consistently found that HTPAP mRNA and protein levels were significantly higher in promoter I than that of promoter II+III (p<0.001). Invasion was increased in HCC cells transfected with promoters II+III compared to those transfected with promoter I (p<0.05). The HTPAP promoter II+III haplotype was associated with significantly increased metastasis compared to that of promoter I (p = 0.023). The postoperative five-year overall survival of patients with promoters II+III was lower than that of patients with promoter I (p = 0.006). Multivariate analysis showed that the promoter II+III haplotype was an adverse prognostic marker in HCC. The genetic variants at loci –1053 and +64 of the HTPAP promoter affect the expression of HTPAP, which might be a novel determinant and target for HCC prognosis.

Abstract A16: Thrombin promotes hepatocellular carcinoma metastasis via mediating osteopontin-dependent tumor growth and adhesion activity

In our previous study, osteopontin (OPN) was identified as one of the leading genes that promote the metastasis of hepatocellular carcinoma (HCC), and a potential therapeutic target for HCC metastasis. The serine protease thrombin can interact with OPN and modify its biologic activity. To explore the role of thrombin alone or collaborating with OPN in HCC, we investigated the thrombin level and its correlation to the prognosis of 72 HCCs with different OPN backgrounds using real-time PCR and Western blot, and evaluated the effects of OPN fragments formed by thrombin cleavage on in vitro proliferation and adhesion of HCC cells. We found that the expression level of thrombin was positively related to the metastatic potentials of HCC cell lines, and was remarkably overexpressed in HCCs compared with the adjacent nontumor tissues. In addition, HCC tissues from patients with recurrent disease displayed much higher thrombin levels, particularly in those with OPN overexpressed. In the immunohistochemical study of 230 HCCs, only in those with a higher OPN level, a significant association was found between the higher thrombin level and the overall survival (OS; P &lt; 0.01) and time to recurrence (TTR; P &lt; 0.0001) of patients. Assays in vitro demonstrated that thrombin could promote the proliferation and adhesion of OPN+ HCC cells. And N-terminal of OPN showed better effects on the proliferation and adhesion abilities of HCC cells than the intact protein. Thrombin treatment could activate FAK pathway of OPN+ HCC cells, and this activation was blocked by the inhibition of integrin β1. Conclusions: Thrombin plays an important role in OPN-mediated aggressive phenotype and poor prognosis of HCC, which may be through the activation of the integrin β1 -FAK signaling. So, thrombin might be a potential therapeutic target to combat HCC progression in thrombin+/OPN+ patients.

Citation Information: Clin Cancer Res 2010;16(14 Suppl):A16.

Cirrhotic-extracellular matrix attenuates aPD-1 treatment response by initiating immunosuppressive neutrophil extracellular traps formation in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is closely associatedwith chronic liver diseases, particularly liver cirrhosis, which has an altered extracellular matrix (ECM) composition. The influence and its mechanism of the cirrhotic-ECM on the response of HCC to immune checkpoint inhibitor (ICI) remains less clarified.

METHODS

In silico, proteomic and pathological assessment of alteration of cirrhotic-ECM were applied in clinical cohort. Multiple pre-clinical models with ECM manipulation were used to evaluate cirrhotic-ECM's effect on ICI treatment. In silico, flow cytometry and IHC were applied to explore how cirrhotic-ECM affect HCC microenvironment. In vitro and in vivo experiments were carried out to identify the mechanism of how cirrhotic-ECM undermined ICI treatment.

RESULTS

We defined "a pro-tumor cirrhotic-ECM" which was featured as the up-regulation of collagen type 1 (Col1). Cirrhotic-ECM/Col1 was closely related to impaired T cell function and limited anti PD-1 (aPD-1) response of HCC patients from the TCGA pan cancer cohort and the authors' institution, as well as in multiple pre-clinical models. Mechanically, cirrhotic-ECM/Col1 orchestrated an immunosuppressive microenvironment (TME) by triggering Col1-DDR1-NFκB-CXCL8 axis, which initiated neutrophil extracellular traps (NETs) formation to shield HCC cells from attacking T cells and impede approaching T cells. Nilotinib, an inhibitor of DDR1, reversed the neutrophils/NETs dominant TME and efficiently enhanced the response of HCC to aPD-1.

CONCLUSIONS

Cirrhotic-ECM modulated a NETs enriched TME in HCC, produced an immune suppressive TME and weakened ICI efficiency. Col1 receptor DDR1 could be a potential target synergically used with ICI to overcome ECM mediated ICI resistance. These provide a mechanical insight and novel strategy to overcome the ICI resistance of HCC.

Interleukin-6 enhances cancer stemness and promotes metastasis of hepatocellular carcinoma via up-regulating osteopontin expression

Interleukin-6 (IL-6), one of the most important inflammatory cytokines, plays a pivotal role in metastasis and stemness of solid tumors. However, the underlying mechanisms of IL-6 in HCC metastasis remain unclear. In the present study, we demonstrated that stemness and metastatic potential of HCC cells were significantly enhanced after IL-6 stimulation. IL-6 could induce expression of osteopontin (OPN), along with other stemness-related genes, including HIF1α, BMI1, and HEY1. Block of OPN induction could significantly abrogate the effect of IL-6 on stemness and metastasis of HCC cells. Furthermore, IL-6 level was positively correlated with OPN in HCC. Patients with high plasma IL-6 or OPN level had poorer prognosis. In multivariate analysis, IL-6 and OPN were demonstrated to be independent prognostic indicators for HCC patients, and their combination had a better prognostic performance than IL-6 or OPN alone. Collectively, our findings indicate that IL-6 could enhance stemness and promote metastasis of HCC via up-regulating OPN expression, which can be a potential therapeutic target for combating HCC metastasis, and the combination of IL-6 and OPN serves as a promising prognostic predictor for HCC.