Tumor-derived exosomes induce immunosuppressive macrophages to foster intrahepatic cholangiocarcinoma progression.

BACKGROUND AND AIMS: Macrophages are prominent components of solid tumors and exhibit distinct functions in different tumor microenvironments. Exosomes are emerging as necessary mediators of the cross-talk between tumor cells and the microenvironment. However, the underlying mechanisms of exosomes involving into crosstalk between tumor cells and macrophages during disease progression of intrahepatic cholangiocarcinoma (ICC) have not been yet fully realized. APPROACH AND RESULTS: We found that the macrophages of ICC tumor tissues up-regulated the expression levels of immunosuppressive molecule programmed death-ligand 1 (PD-L1). Increased PD-L1+ macrophages in tumor tissues effectively suppressed T-cell immunity and correlated with poor survival rates in patients with ICC. High-throughput RNA-sequencing analysis that was performed to identify differential levels of microRNAs (miRNAs) between exosomes derived from ICC cells and primary human intrahepatic biliary epithelial cells revealed that miR-183-5p was increased in ICC cell-derived exosomes. Exosomal miR-183-5p inhibited phosphatase and tensin homolog (PTEN) expression, to subsequently affect the elevations on both phosphorylated AKT and PD-L1 expression in macrophages. Furthermore, macrophages that treated with ICC cell-derived exosomes significantly suppressed T-cell immunity in vitro and contributed to the growth and progression of ICC in vivo, which were reversible through blockages on PD-L1 of these macrophages. Finally, clinical data showed that up-regulated levels of plasma exosomal miR-183-5p correlated with poor prognosis of patients with ICC after curative resection. CONCLUSIONS: Tumor-derived exosomal miR-183-5p up-regulates PD-L1-expressing macrophages to foster immune suppression and disease progression in ICC through the miR-183-5p/PTEN/AKT/PD-L1 pathway. Exosomal miR-183-5p is a potential predictive biomarker for ICC progression and a potential target for development of therapeutic strategies against immune tolerance feature of ICC.

A retrospective cohort study of preoperative lipid indices and their impact on new-onset diabetes after liver transplantation.

BACKGROUND: The correlation between preoperative lipid profiles and new-onset diabetes after transplantation (NODAT) remains relatively unexplored in liver transplant recipients (LTRs). Thus, we aimed to investigate the preoperative lipid profiles in Chinese LTRs and evaluate the different influences of preoperative total cholesterol, total triglycerides (TG), high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol on the development of NODAT in both sexes. METHODS: A total of 767 Chinese LTRs from Zhongshan Hospital were retrospectively evaluated. NODAT was defined according to the American Diabetes Association guidelines; the relationship between each preoperative lipid index and NODAT development was analyzed separately in men and women. RESULTS: Pretransplant hypotriglyceridemia was observed in 35.72% of the total LTRs. In men, only the preoperative TG level was significantly associated with incident NODAT after adjusting for potential confounders (hazard ratio 1.37, 95% confidence interval 1.13-1.66, P = .001). There was a nonlinear relationship between the preoperative TG level and NODAT risk. The risk of NODAT significantly increased with preoperative a TG level above 0.54 mmol/L (log-likelihood ratio test, P = .043). In women, no significant association was observed. CONCLUSION: Among male LTRs, a higher preoperative TG level, even at a low level within the normal range, was significantly and nonlinearly associated with an increased risk of NODAT.

Long non-coding RNA 00607 as a tumor suppressor by modulating NF-κB p65/p53 signaling axis in hepatocellular carcinoma.

Accumulating evidence suggests that long non-coding RNA (lncRNA) plays important roles in some malignant tumors. However, the mechanism underlying how lncRNA regulates hepatocellular carcinoma (HCC) process remains largely unknown. In this study, we explored the potential role of lncRNA 00607 as a novel tumor suppressor in HCC. In this study, we examined the regulation of lncRNA 00607 by the important inflammatory cytokine tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). We also determined the expression of LINC000607 in 159 HCC tumors and paired adjacent tissues. Effects of LINC000607 in HCC proliferation and apoptosis were examined in vitro in HCC cell lines and in vivo tumor xenografts. Furthermore, we also examine underlying mechanism by which lncRNA 00607 regulates NF-κB p65 and how LIN00607 exerts its tumor suppressor role in HCC. We found that lncRNA 00607 expression level is lower in HCC tumors compared with matched normal liver tissue, and its low expression predicts worse prognosis in HCC. Functionally, lncRNA 00607 overexpression leads to decreased HCC cell proliferation in vitro and in vivo, enhanced apoptosis and chemotherapeutic drug sensitivity. Mechanistically, lncRNA 00607 inhibits the p65 transcription by binding to the p65 promoter region, therefore contributing to increased p53 levels in HCC. Taken together, the findings of this study show that the TNF-α/IL-6-lncRNA 00607-NF-κB p65/p53 signaling axis represents a novel therapeutic avenue in cancer chemotherapy.

Circumventing intratumoral heterogeneity to identify potential therapeutic targets in hepatocellular carcinoma.

BACKGROUND & AIMS: Identifying target genetic mutations in hepatocellular carcinoma (HCC) for therapy is made challenging by intratumoral heterogeneity. Circulating cell-free DNAs (cfDNA) may contain a more complete mutational spectrum compared to a single tumor sample. This study aimed to identify the most efficient strategy to identify all the mutations within heterogeneous HCCs. METHODS: Whole exome sequencing (WES) and targeted deep sequencing (TDS) were carried out in 32 multi-regional tumor samples from five patients. Matched preoperative cfDNAs were sequenced accordingly. Intratumoral heterogeneity was measured using the average percentage of non-ubiquitous mutations (present in parts of tumor regions). Profiling efficiencies of single tumor specimen and cfDNA were compared. The strategy with the highest performance was used to screen for actionable mutations. RESULTS: Variable levels of heterogeneity with branched and parallel evolution patterns were observed. The heterogeneity decreased at higher sequencing depth of TDS compared to measurements by WES (28.1% vs. 34.9%, p<0.01) but remained unchanged when additional samples were analyzed. TDS of single tumor specimen identified an average of 70% of the total mutations from multi-regional tissues. Although genome profiling efficiency of cfDNA increased with sequencing depth, an average of 47.2% total mutations were identified using TDS, suggesting that tissue samples outperformed it. TDS of single tumor specimen in 66 patients and cfDNAs in four unresectable HCCs showed that 38.6% (26/66 and 1/4) of patients carried mutations that were potential therapeutic targets. CONCLUSIONS: TDS of single tumor specimen could identify actionable mutations targets for therapy in HCC. cfDNA may serve as secondary alternative in profiling HCC genome. LAY SUMMARY: Targeted deep sequencing of single tumor specimen is a more efficient method to identify mutations in hepatocellular carcinoma made from mixed subtypes compared to circulating cell-free DNA in blood. cfDNA may serve as secondary alternative in profiling HCC genome. Identifying mutations may help clinicians choose targeted therapy for better individual treatments.

Tumour-suppressive role of PTPN13 in hepatocellular carcinoma and its clinical significance.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer mortality and carries a dismal prognosis. The present study aimed to identify the tumour-suppressive role and clinical implications of PTPN13 in HCC progression. We tested the effects of PTPN13 expression in proliferation, invasion, epithelial-mesenchymal transition and associated pathways in HCC cell lines in vitro. Furthermore, its clinical relevance was evaluated in a tissue microarray analysis of samples from 282 HCC patients. Various HCC cell lines expressed relatively low PTPN13 protein levels in vitro. PTPN13 overexpression significantly inhibited the progression of HCC cells, possibly by inhibiting epithelial-mesenchymal transition through inactivation of the EGFR/ERK signalling pathway. Tissue microarray analysis revealed that high PTPN13 expression was correlated with a favourable prognosis in postoperative HCC patients. This study demonstrated the tumour suppressor, PTPN13, as an alternative therapeutic target for HCC.

Naive Treg-like CCR7(+) mononuclear cells indicate unfavorable prognosis in hepatocellular carcinoma.

Chemokine receptor-like 1 (CCRL1) has the potential in creating a low level of CCL19 and CCL21 to hinder CCR7(+) cell tracking to tumor tissue. Previously, we found a tumor suppressive role of CCRL1 by impairing CCR7-related chemotaxis of tumor cells in human hepatocellular carcinoma (HCC). Here, we reported a contribution of CCR7(+) mononuclear cells in the tumor microenvironment to the progression of disease. Immunohistochemistry was used to investigate the distribution and clinical significance of CCR7(+) cells in a cohort of 240 HCC patients. Furthermore, the phenotype, composition, and functional status of CCR7(+) cells were determined by flow cytometry, immunofluorescence, and in vitro co-culture assays. We found that CCR7(+) mononuclear cells were dispersed around tumor tissue and negatively related to tumoral expression of CCRL1 (P < 0.001, r = 0.391). High density of CCR7(+) mononuclear cells positively correlated with the absence of tumor capsule, vascular invasion, and poor differentiation (P < 0.05). Survival analyses revealed that increased number of CCR7(+) mononuclear cells was significantly associated with worse survival and increased recurrence. We found that CCR7(+) mononuclear cells featured a naive Treg-like phenotype (CD45RA(+)CD25(+)FOXP3(+)) and possessed tumor-promoting potential by producing TGF-ß1. Moreover, CCR7(+) cells were also composed of several immunocytes, a third of which were CD8(+) T cells. CCR7(+) Treg-like cells facilitate tumor growth and indicate unfavorable prognosis in HCC patients, but fortunately, their tracking to tumor tissue is under the control of CCRL1.

[Corrigendum] Macrophage­secreted IL­8 induces epithelial­mesen-chymal transition in hepatocellular carcinoma cells by activating the JAK2/STAT3/Snail pathway.

Subsequently to the publication of the above article, an interested reader drew to the authors' attention that a possible error had been identified in the selection of images in Figs. 1 and/or 7. After having consulted their original data, the authors realized that an erroneous image appeared on p. 593, in Fig. 7F [the 'Hep­G2 / IL­8 (5 ng/ml)' data panel], where part of this figure panel was overlapping with an image on p. 589 in Fig. 1C (the 'Hep­G2 Co­cultured' data panel). After a thorough review and verification of the data by all the authors, they have confirmed that the original data presented in the paper were accurate, and the error was solely due to the selection of an incorrect image during figure arrangement. The authors confirm that this mistake in image selection did not affect the overall conclusions reported in the article. A corrected version of Fig. 7, including the correct data for the 'Hep­G2 / IL­8 (5 ng/ml)' panel in Fig. 7F, is shown on the next page. The authors are grateful to the Editor of International Journal of Oncology for granting them the opportunity to publish this Corrigendum. All the authors agree to the publication of this Corrigendum, and apologize to the readership for any inconvenience caused. [International Journal of Oncology 46: 587­596, 2015; DOI: 10.3892/ijo.2014.2761].

Serial circulating tumor DNA profiling predicts tumor recurrence after liver transplantation for liver cancer.

BACKGROUND: Minimal residual disease (MRD) is proposed to be responsible for tumor recurrence. The role of circulating tumor DNA (ctDNA) to detect MRD, monitor recurrence, and predict prognosis in liver cancer patients undergoing liver transplantation (LT) remains unrevealed. METHODS: Serial blood samples were collected to profile ctDNA mutational changes. Baseline ctDNA mutational profiles were compared with those of matched tumor tissues. Correlations between ctDNA status and recurrence rate (RR) and recurrence-free survival (RFS) were analyzed, respectively. Dynamic change of ctDNA was monitored to predict tumor recurrence. RESULTS: Baseline mutational profiles of ctDNA were highly concordant with those of tumor tissues (median, 89.85%; range 46.2-100%) in the 74 patients. Before LT, positive ctDNA status was associated with higher RR (31.7% vs 11.5%; p = 0.001) and shorter RFS than negative ctDNA status (17.8 vs 19.4 months; p = 0.019). After LT, the percentage of ctDNA positivity decreased (17.6% vs 47.0%; p < 0.001) and patients with positive ctDNA status had higher RR (46.2% vs 21.3%; p < 0.001) and shorter RFS (17.2 vs 19.2 months; p = 0.010). Serial ctDNA profiling demonstrated patients with decreased or constant negative ctDNA status had lower RR (33.3% vs 50.0%; p = 0.015) and favorable RFS (18.2 vs 15.0 months, p = 0.003) than those with increased or constant positive ctDNA status. Serial ctDNA profiling predicted recurrence months ahead of imaging evidence and serum tumor biomarkers. CONCLUSIONS: ctDNA could effectively detect MRD and predict tumor recurrence in liver cancer patients undergone LT.

Macro CD5L+ deteriorates CD8+T cells exhaustion and impairs combination of Gemcitabine-Oxaliplatin-Lenvatinib-anti-PD1 therapy in intrahepatic cholangiocarcinoma.

Intratumoral immune status influences tumor therapeutic response, but it remains largely unclear how the status determines therapies for patients with intrahepatic cholangiocarcinoma. Here, we examine the single-cell transcriptional and TCR profiles of 18 tumor tissues pre- and post- therapy of gemcitabine plus oxaliplatin, in combination with lenvatinib and anti-PD1 antibody for intrahepatic cholangiocarcinoma. We find that high CD8 GZMB+ and CD8 proliferating proportions and a low Macro CD5L+ proportion predict good response to the therapy. In patients with a poor response, the CD8 GZMB+ and CD8 proliferating proportions are increased, but the CD8 GZMK+ proportion is decreased after the therapy. Transition of CD8 proliferating and CD8 GZMB+ to CD8 GZMK+ facilitates good response to the therapy, while Macro CD5L+-CD8 GZMB+ crosstalk impairs the response by increasing CTLA4 in CD8 GZMB+. Anti-CTLA4 antibody reverses resistance of the therapy in intrahepatic cholangiocarcinoma. Our data provide a resource for predicting response of the combination therapy and highlight the importance of CD8+T-cell status conversion and exhaustion induced by Macro CD5L+ in influencing the response, suggesting future avenues for cancer treatment optimization.

Loss of 5-hydroxymethylcytosine induces chemotherapy resistance in hepatocellular carcinoma via the 5-hmC/PCAF/AKT axis.

Multidrug resistance is a major challenge in treating advanced hepatocellular carcinoma (HCC). Although recent studies have reported that the multidrug resistance phenotype is associated with abnormal DNA methylation in cancer cells, the epigenetic mechanism underlying multidrug resistance remains unknown. Here, we reported that the level of 5-hydroxymethylcytosine (5-hmC) in human HCC tissues was significantly lower than that in adjacent liver tissues, and reduced 5-hmC significantly correlated with malignant phenotypes, including poor differentiation and microvascular invasion; additionally, loss of 5-hmC was related to chemotherapy resistance in post-transplantation HCC patients. Further, the 5-hmC level was regulated by ten-eleven translocation 2 (TET2), and the reduction of TET2 in HCC contributes to chemotherapy resistance through histone acetyltransferase P300/CBP-associated factor (PCAF) inhibition and AKT signaling hyperactivation. In conclusion, loss of 5-hmC induces chemotherapy resistance through PCAF/AKT axis and is a promising chemosensitivity prediction biomarker and therapeutic target for HCC patients.

The clinical implications and molecular features of intrahepatic cholangiocarcinoma with perineural invasion.

BACKGROUND: Perineural invasion (PNI) is associated with metastasis in malignancies, including intrahepatic cholangiocarcinoma (ICC), and is correlated with poor prognosis. METHODS: The study included three large cohorts: ZS-ICC and TMA cohorts from our team, MSK cohort from a public database, and a small cohort named cohort 4. Prognostic implications of PNI were investigated in MSK cohort and TMA cohort. PNI-related genomic and transcriptomic profiles were analyzed in MSK and ZS-ICC cohorts. GO, KEGG, and ssGSEA analyses were performed. Immunohistochemistry was used to investigate the relationship between PNI and markers of neurons, hydrolases, and immune cells. The efficacy of adjuvant therapy in ICC patients with PNI was also assessed. RESULTS: A total of 30.6% and 20.7% ICC patients had PNI in MSK and TMA cohorts respectively. Patients with PNI presented with malignant phenotypes such as high CA19-9, the large bile duct type, lymph node invasion, and shortened overall survival (OS) and relapse-free survival (RFS). Nerves involved in PNI positively express tyrosine hydroxylase (TH), a marker of sympathetic nerves. Patients with PNI showed high mutation frequency of KRAS and an immune suppressive metastasis prone niche of decreased NK cell, increased neutrophil, and elevated PD-L1, CD80, and CD86 expression. Patients with PNI had an extended OS after adjuvant therapy with TEGIO, GEMOX, or capecitabine. CONCLUSION: Our study deciphered the genomic features and the immune suppressive metastasis-prone niche in ICC with PNI. Patients with PNI showed a poor prognosis after surgery but a good response to adjuvant chemotherapy.

The Efficacy and Safety of Hepatic Arterial Infusion Chemotherapy Based on FOLFIRI for Advanced Intrahepatic Cholangiocarcinoma as Second-Line and Successive Treatment: A Real-World Study.

Objective: Intrahepatic cholangiocarcinoma (iCCA) is a primary liver malignancy with a poor prognosis and limited treatment. Cisplatin with gemcitabine is used as the standard first-line chemotherapy regimen; however, there is still no robust evidence for second-line and successive treatments. Although preliminary evidence suggests a vital role of precision therapy or immunotherapy in a subset of patients, the gene alteration rate is relatively low. Herein, we explored the second-line and successive treatments using hepatic arterial infusion chemotherapy (HAIC) based on FOLFIRI after the failure of gemcitabine and platinum combined with target and immunotherapy in refractory CCAs. Methods: Advanced patients with iCCAs confirmed by diagnostic pathology, who progressed at least on a gemcitabine/platinum doublet and/or other systemic chemotherapy combined with target therapy and immune checkpoint inhibitor, were included. All patients received infusional 5-fluorouracil/leucovorin with irinotecan (FOLFIRI) via HAIC until progression or unacceptable toxicity. The primary objective was the feasibility of treatment, with secondary objectives of disease control rate (DCR) and 6-month survival rate. Results: A total of 9 iCCA patients treated between Dec 2020 and May 2021 were enrolled; 2 patients suffered from distant metastasis, while 7 had local lymph node metastasis and portal vein or hepatic vein invasion. HAIC was delivered as second-line therapy in 6/9 patients, while a third or successive therapy in 3/9 patients. The patients accepted an average of 2.90 ± 1.69 cycles of HAIC. The objective response rate was 22.2%; the disease control rate was 55.5% (5/9); median progression-free survival was 5 months; and 6-month survival rate was 66.7% (6/9). Conclusions: Our results provide preliminary evidence that HAIC based on FOLFIRI regimen is efficient and safe in some patients progressing after previous treatment. Therefore, HAIC may be a promising and valuable complementary therapy for advanced CCAs as a second-line and successive therapy. Otherwise, the combination of HAIC with precision medicine may improve clinical benefits (clinical registration number: 2021BAT4857).

Immune checkpoint inhibitor plus tyrosine kinase inhibitor for unresectable hepatocellular carcinoma in the real world.

BACKGROUND: This study aimed to evaluate safety and efficacy of programmed death-1 (PD-1) inhibitor sintilimab plus tyrosine kinase inhibitors (TKI) in a real-word cohort of patients with unresectable hepatocellular carcinoma (uHCC). METHODS: A total of 60 patients treated with sintilimab plus TKI between February 2019 and December 2019 were enrolled. Radiological response was recorded by computed tomography (CT) or magnetic resonance imaging (MRI) at baseline and every 6-12 weeks after treatment initiation. Tumor response was assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and HCC-specific modified RECIST (mRECIST). RESULTS: As of the data cutoff on September 30st, 2020, the median duration of follow-up was 10.4 (4.3-23.9) months. The objective response rate (ORR) and disease control rate (DCR) were 36.7% (95% CI: 24.9-48.5%), 81.7% (95% CI: 71.9-91.5%) according to the RECIST 1.1, and 52.8% (95% CI: 39.1-66.5%), 83.0% (95% CI: 73.2-93.8%) according to mRECIST criteria. Among 36 HCC patients with multinodular HCC or locally-advanced HCC with portal vein tumor thrombus (PVTT), 14 patients received one session of transarterial chemoembolization (TACE) within 1 month before or after the combinational systemic therapies, and the rest 22 patients did not receive any local regional therapies. After propensity score matching, patients from the TACE group tended to have a longer PFS (median, 10.1 vs. 9.1 months, P=0.73) than those from the non-TACE group but without significant differences. A total of 8 patients received surgical resection after the combined systemic therapies and 3 patients achieved pathological CR. No recurrence or metastasis was observed in 6 patients. A total of 46 (76.7%) patients reported adverse event (AE) with any grade and 8 (13.3%) patients discontinued the combination therapy due to grade 3/4 severe adverse events. CONCLUSIONS: PD-1-targeted immunotherapy sintilimab plus TKIs exhibited promising efficacy with tolerable toxicity in unresectable HCC. The addition of TACE to the combined systemic therapies also resulted in a favorable tumor control and safety. For select responders, surgical resection might be a choice for radical treatment.

The mRNA-miRNA-lncRNA Regulatory Network and Factors Associated with Prognosis Prediction of Hepatocellular Carcinoma.

The aim of this study was to identify novel prognostic mRNA and microRNA (miRNA) biomarkers for hepatocellular carcinoma (HCC) using methods in systems biology. Differentially expressed mRNAs, miRNAs, and long non-coding RNAs (lncRNAs) were compared between HCC tumor tissues and normal liver tissues in The Cancer Genome Atlas (TCGA) database. Subsequently, a prognosis-associated mRNA co-expression network, an mRNA-miRNA regulatory network, and an mRNA-miRNA-lncRNA regulatory network were constructed to identify prognostic biomarkers for HCC through Cox survival analysis. Seven prognosis-associated mRNA co-expression modules were obtained by analyzing these differentially expressed mRNAs. An expression module including 120 mRNAs was significantly correlated with HCC patient survival. Combined with patient survival data, several mRNAs and miRNAs, including CHST4, SLC22A8, STC2, hsa-miR-326, and hsa-miR-21 were identified from the network to predict HCC patient prognosis. Clinical significance was investigated using tissue microarray analysis of samples from 258 patients with HCC. Functional annotation of hsa-miR-326 and hsa-miR-21-5p indicated specific associations with several cancer-related pathways. The present study provides a bioinformatics method for biomarker screening, leading to the identification of an integrated mRNA-miRNA-lncRNA regulatory network and their co-expression patterns in relation to predicting HCC patient survival.

Plasma MicroRNA Panel Predicts Early Tumor Recurrence in Patients with Hepatocellular Carcinoma after Liver Transplantation.

Background: This study aimed to evaluate the role of plasma microRNA panel (miR-122, miR-192, miR-21, miR-223, miR-26a, miR-27a and miR-801) for prediction and surveillance of early tumor recurrence in hepatocellular carcinoma (HCC) patients who had undergone liver transplantation (LT). Methods: The expression of plasma microRNA panel was assayed in 193 HCC patients (training cohort, n =151; validation cohort, n = 42). Sensitivity and specificity for detecting post-transplant HCC recurrence, and the relationship of microRNA panel expression with clinical characteristics were analyzed accordingly. The prognostic value of microRNA panel was compared with that of AFP (alpha-fetoprotein) and DCP (Des-gamma-carboxyprothrombin). Cox regression analyses were used to evaluate independent prognostic factors. Results: In the training cohort, the rate of positive plasma microRNA panel status at 7-14 days after LT (late phase; 44.2%) decreased than that before (76.2%, P < 0.001) and 1-6 days after LT (early phase; 78.5%, P < 0.001). At late phase, positive microRNA panel status correlated with higher early tumor recurrence rate (one year after LT) than negative status (45.9% vs 10.7%; P < 0.001). Patients with persistent positive microRNA panel status both before and after LT had the highest early tumor recurrence rate in this cohort (54.9%, P < 0.001). The results were consistent in the validation cohort. Cox regression analysis found that positive plasma microRNA panel status at late phase was the only independent risk factor for early recurrence (HR: 4.903, 95% CI = 2.195 - 10.951; P < 0.001). Dynamic monitoring demonstrated plasma microRNA panel status changed from negative to positive earlier than AFP and DCP upon recurrence, and the median time between positivity of plasma microRNA and imaging evidence of recurrence was 2.4 (0.5-10.0) months. Conclusions: Plasma microRNA panel could be a noninvasive biomarker for prediction and surveillance of early tumor recurrence in HCC patients who have undergone LT.

Characterization of immune infiltration in sarcomatoid hepatocellular carcinoma.

Sarcomatoid hepatocellular carcinoma (sHCC) is a rare type of liver malignancy. Currently, the tumor immune features of sHCC are poorly understood. We recruited 31 patients with resected sHCC for whom tissue samples and complete clinicopathologic and follow-up data were available. To understand the immune infiltration of sHCC, immunohistochemical staining was performed on the resected sHCC samples to compare the expressions of programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), B7-H3, indoleamine 2,3-dioxygenase (IDO), lymphocyte-activation gene 3 (LAG-3), CD8, FOXP3, and CD68 in tumor and peritumoral tissues. Kaplan-Meier and Cox regression analyses were used to assess the predictive value of immune markers. Sarcomatoid components were characterized with significantly higher expression of PD-L1 and B7-H3 in tumor cells than in conventional HCC components, as well as in peritumoral tissue. Additionally, sarcomatoid components had a higher density of FOXP3+ and LAG-3+ cells and a lower density of CD8+ cells than conventional HCC components or peritumoral tissue. Higher expression of PD-L1 in tumor cells significantly correlated with higher densities of CD8+, PD-1+, and LAG-3+ cells. Increased tumor PD-L1 expression and decreased CD8+ T-cell density were associated with poor overall survival (OS) and disease-free survival (DFS) in patients of sHCC. These findings suggest further characterization on relative mechanism of sHCC immune infiltration may identify therapeutic targets for immunotherapy.

Amplification of spatially isolated adenosine pathway by tumor-macrophage interaction induces anti-PD1 resistance in hepatocellular carcinoma.

BACKGROUND: Immune checkpoint blockade resistance narrows the efficacy of cancer immunotherapies, but the underlying mechanism remains elusive. Delineating the inherent mechanisms of anti-PD1 resistance is important to improve outcome of patients with advanced HCC. METHOD: The level of cricTMEM181 was measured in HCC patients with anti-PD1 therapy by RNA sequencing and then confirmed by qPCR and Sanger sequencing. Immune status in tumor microenvironment of HCC patients or mice models was evaluated by flow cytometry and IHC. Exosomes from HCC cell lines were isolated by ultracentrifugation, and their internalization by macrophage was confirmed by immunofluorescence. The underlying mechanism of HCC-derived exosomal circTMEM181 to macrophage was confirmed by SILAC, RNA FISH and RNA immunoprecipitation. The ATP-ADO pathway amplified by HCC-macrophage interaction was evaluated through ATP, AMP and ADO measurement and macrophage-specific CD39 knockout mice. The role of circTMEM181 in anti-PD1 therapy and its clinical significance were also determined in our retrospective HCC cohorts. RESULTS: Here, we found that circTMEM181 was elevated in hepatocellular carcinoma (HCC) patients responding poorly to anti-PD1 therapy and in HCC patients with a poor prognosis after operation. Moreover, we also found that high exosomal circTMEM181 favored the immunosuppressive microenvironment and endowed anti-PD1 resistance in HCC. Mechanistically, exosomal circTMEM181 sponged miR-488-3p and upregulated CD39 expression in macrophages. Using macrophage-specific CD39 knockout mice and pharmacologic approaches, we revealed a novel mode of anti-PD1 resistance in HCC. We discovered that cell-specific CD39 expression in macrophages and CD73 expression in HCC cells synergistically activated the eATP-adenosine pathway and produced more adenosine, thereby impairing CD8+ T cell function and driving anti-PD1 resistance. CONCLUSION: In summary, HCC-derived exosomal circTMEM181 contributes to immunosuppression and anti-PD1 resistance by elevating CD39 expression, and inhibiting the ATP-adenosine pathway by targeting CD39 on macrophages can rescue anti-PD1 therapy resistance in HCC.

CTLA-4 Synergizes With PD1/PD-L1 in the Inhibitory Tumor Microenvironment of Intrahepatic Cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is highly invasive and carries high mortality due to limited therapeutic strategies. In other solid tumors, immune checkpoint inhibitors (ICIs) target cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD1), and the PD1 ligand PD-L1 has revolutionized treatment and improved outcomes. However, the relationship and clinical significance of CTLA-4 and PD-L1 expression in ICC remains to be addressed. Deciphering CTLA-4 and PD-L1 interactions in ICC enable targeted therapy for this disease. In this study, immunohistochemistry (IHC) was used to detect and quantify CTLA-4, forkhead box protein P3 (FOXP3), and PD-L1 in samples from 290 patients with ICC. The prognostic capabilities of CTLA-4, FOXP3, and PD-L1 expression in ICC were investigated with the Kaplan-Meier method. Independent risk factors related to ICC survival and recurrence were assessed by the Cox proportional hazards models. Here, we identified that CTLA-4+ lymphocyte density was elevated in ICC tumors compared with peritumoral hepatic tissues (P <.001), and patients with a high density of CTLA-4+ tumor-infiltrating lymphocytes (TILsCTLA-4 High) showed a reduced overall survival (OS) rate and increased cumulative recurrence rate compared with patients with TILsCTLA-4 Low (P <.001 and P = .024, respectively). Similarly, patients with high FOXP3+ TILs (TILsFOXP3 High) had poorer prognoses than patients with low FOXP3+ TILs (P = .021, P = .034, respectively), and the density of CTLA-4+ TILs was positively correlated with FOXP3+ TILs (Pearson r = .31, P <.001). Furthermore, patients with high PD-L1 expression in tumors (TumorPD-L1 High) and/or TILsCTLA-4 High presented worse OS and a higher recurrence rate than patients with TILsCTLA-4 LowTumorPD-L1 Low. Moreover, multiple tumors, lymph node metastasis, and high TumorPD-L1/TILsCTLA-4 were independent risk factors of cumulative recurrence and OS for patients after ICC tumor resection. Furthermore, among ICC patients, those with hepatolithiasis had a higher expression of CTLA-4 and worse OS compared with patients with HBV infection or undefined risk factors (P = .018). In conclusion, CTLA-4 is increased in TILs in ICC and has an expression profile distinct from PD1/PD-L1. TumorPD-L1/TILsCTLA-4 is a predictive factor of OS and ICC recurrence, suggesting that combined therapy targeting PD1/PD-L1 and CTLA-4 may be useful in treating patients with ICC.