SIGLEC15, negatively correlated with PD-L1 in HCC, could induce CD8+ T cell apoptosis to promote immune evasion.

Functional roles of SIGLEC15 in hepatocellular carcinoma (HCC) were not clear, which was recently found to be an immune inhibitor with similar structure of inhibitory B7 family members. SIGLEC15 expression in HCC was explored in public databases and further examined by PCR analysis. SIGLEC15 and PD-L1 expression patterns were examined in HCC samples through immunohistochemistry. SIGLEC15 expression was knocked-down or over-expressed in HCC cell lines, and CCK8 tests were used to examine cell proliferative ability in vitro. Influences of SIGLEC15 expression on tumor growth were examined in immune deficient and immunocompetent mice respectively. Co-culture system of HCC cell lines and Jurkat cells, flow cytometry analysis of tumor infiltrated immune cells and further sequencing analyses were performed to investigate how SIGLEC15 could affect T cells in vitro and in vivo. We found SIGLEC15 was increased in HCC tumor tissues and was negatively correlated with PD-L1 in HCC samples. In vitro and in vivo models demonstrated inhibition of SIGLEC15 did not directly influence tumor proliferation. However, SIGLEC15 could promoted HCC immune evasion in immune competent mouse models. Knock-out of Siglec15 could inhibit tumor growth and reinvigorate CD8+ T cell cytotoxicity. Anti-SIGLEC15 treatment could effectively inhibit tumor growth in mouse models with or without mononuclear phagocyte deletion. Bulk and single-cell RNA sequencing data of treated mouse tumors demonstrated SIGLEC15 could interfere CD8+ T cell viability and induce cell apoptosis. In all, SIGLEC15 was negatively correlated with PD-L1 in HCC and mainly promote HCC immune evasion through inhibition of CD8+ T cell viability and cytotoxicity.

CRKL dictates anti-PD-1 resistance by mediating tumor-associated neutrophil infiltration in hepatocellular carcinoma.

BACKGROUND & AIMS: The effectiveness of immune checkpoint inhibitor (ICI) therapy for hepatocellular carcinoma (HCC) is limited by treatment resistance. However, the mechanisms underlying immunotherapy resistance remain elusive. We aimed to identify the role of CT10 regulator of kinase-like (CRKL) in resistance to anti-PD-1 therapy in HCC. METHODS: Gene expression in HCC specimens from 10 patients receiving anti-PD-1 therapy was identified by RNA-sequencing. A total of 404 HCC samples from tissue microarrays were analyzed by immunohistochemistry. Transgenic mice (Alb-Cre/Trp53fl/fl) received hydrodynamic tail vein injections of a CRKL-overexpressing vector. Mass cytometry by time of flight was used to profile the proportion and status of different immune cell lineages in the mouse tumor tissues. RESULTS: CRKL was identified as a candidate anti-PD-1-resistance gene using a pooled genetic screen. CRKL overexpression nullifies anti-PD-1 treatment efficacy by mobilizing tumor-associated neutrophils (TANs), which block the infiltration and function of CD8+ T cells. PD-L1+ TANs were found to be an essential subset of TANs that were regulated by CRKL expression and display an immunosuppressive phenotype. Mechanistically, CRKL inhibits APC (adenomatous polyposis coli)-mediated proteasomal degradation of ß-catenin by competitively decreasing Axin1 binding, and thus promotes VEGFα and CXCL1 expression. Using human HCC samples, we verified the positive correlations of CRKL/ß-catenin/VEGFα and CXCL1. Targeting CRKL using CRISPR-Cas9 gene editing (CRKL knockout) or its downstream regulators effectively restored the efficacy of anti-PD-1 therapy in an orthotopic mouse model and a patient-derived organotypic tumor spheroid model. CONCLUSIONS: Activation of the CRKL/ß-catenin/VEGFα and CXCL1 axis is a critical obstacle to successful anti-PD-1 therapy. Therefore, CRKL inhibitors combined with anti-PD-1 could be useful for the treatment of HCC. IMPACT AND IMPLICATIONS: Here, we found that CRKL was overexpressed in anti-PD-1-resistant hepatocellular carcinoma (HCC) and that CRKL upregulation promotes anti-PD-1 resistance in HCC. We identified that upregulation of the CRKL/ß-catenin/VEGFα and CXCL1 axis contributes to anti-PD-1 tolerance by promoting infiltration of tumor-associated neutrophils. These findings support the strategy of bevacizumab-based immune checkpoint inhibitor combination therapy, and CRKL inhibitors combined with anti-PD-1 therapy may be developed for the treatment of HCC.

Robotic versus open surgery for simultaneous resection of rectal cancer and liver metastases: a randomized controlled trial.

OBJECTIVE: This study aimed to compare the short-term and long-term outcomes between robotic-assisted simultaneous resection and open surgery in patients with rectal cancer and liver metastases. BACKGROUND: Open simultaneous resection of colorectal cancer and synchronous liver metastases is widely performed and the potential cure for eligible patients. However, the feasibility of robotic simultaneous resection of primary and secondary liver lesions has not been established as a treatment option for metastatic rectal cancer. PATIENTS AND METHODS: A single-center randomized controlled trial was conducted at a hospital in China. Enrolling patients were aged from 18 to 75 years and diagnosed with surgically resectable metastatic rectal cancer (distal extension to ≤15 cm from the anal margin). Patients selected for simultaneous resection were randomly assigned to have robotic or open surgery at a 1:1 ratio. The primary endpoint was the incidence rate of complications within 30 days after surgery. Secondary endpoints were bladder, sexual function, 3-year disease-free survival, and overall survival. RESULTS: A total of 171 patients were enrolled in this trial with 86 in the robotic group and 85 in the open group. As a result, patients in the robotic group demonstrated fewer complications within 30 days after surgery than those in the open group (31.4 vs. 57.6%, P =0.014) and no mortality seen in either group. Patients in the robotic group had less blood loss [mean (SD), 125.5 (38.3) vs. 211.6 (68.7) ml; P <0.001], faster bowel function recovery [mean (SD), 63.7 (27.4) vs. 93.8 (33.5) h P <0.001] and shorter hospital stay [mean (SD), 8.0 (2.2) vs. 10.7 (5.4) days; P <0.001] compared with those in the open group. The robotic group had a faster recovery of bladder and sexual function at 3 months after surgery than that of the open group. The 3-year disease-free survival rate (39.5 vs. 35.3%, P =0.739) and the 3-year overall survival rate (76.7 vs. 72.9%, P =0.712) were not statistically significant between the two groups. CONCLUSIONS: In our randomized clinical trial, robotic simultaneous resection treatment of patients with rectal cancer and liver metastases resulted in fewer surgical complications, and a faster recovery to those of open surgery. Oncological outcomes showed no significant difference between the two groups.

Impact of Surgical Management for Relapse After Conversion Hepatectomy for Initially Unresectable Colorectal Liver Metastasis: A Retrospective Cohort Study.

BACKGROUND: For patients with initially unresectable colorectal liver metastasis (IU-CRLM) receiving conversion therapy, disease relapse after conversion hepatectomy is common. However, few studies have focused on the assessment and management of relapse following conversion hepatectomy for IU-CRLM. METHODS: In the retrospective cohort study, 255 patients with IU-CRLM received conversion therapy and underwent subsequent R0 resection. The treatment effects of repeated liver-directed treatment (RLDT) versus non-RLDT for liver relapse were examined. Survival analysis was evaluated with the use of Cox proportional hazards methods. The importance of RLDT was further confirmed in the propensity score matching (PSM) and subgroup analyses. RESULTS: The 5-year overall survival (OS) rate after conversion hepatectomy was 34.9%. Liver relapse was observed in 208 patients. Of these patients, 106 underwent RLDT (65 underwent repeated hepatectomy and the remainder underwent ablation treatment), while 102 received only palliative chemotherapy. The relapse patients who underwent RLDT had a significantly longer OS than those who did not (hazard ratio (HR): 0.382, 95% CI: 0.259-0.563; P<0.001). In a multivariable analysis, RLDT was independently associated to prolonged survival (HR: 0.309, 95%CI: 0.181-0.529; P<0.001). In the PSM and subgroup analyses, RLDT consistently showed evidence of prolonging OS significantly. CONCLUSION: For IU-CRLM patients with liver relapse following conversion hepatectomy, the RLDT is essential for cure and prolonged survival. To avoid missing the opportunity for RLDT, intensive disease surveillance should be proposed.

Anatomical resection improves relapse-free survival in colorectal liver metastases in patients with KRAS/NRAS/BRAF mutations or right-sided colon cancer: a retrospective cohort study.

BACKGROUND: The type of liver resection (anatomical resection, AR or non-anatomical resection, NAR) for colorectal liver metastases (CRLM) is subject to debate. The debate may persist because some prognostic factors, associated with aggressive tumor biological behavior, have been overlooked. OBJECTIVE: Our study aimed to investigate the characteristics of patients who would benefit more from anatomical resection for CRLM. METHODS: Seven hundred twenty-nine patients who underwent hepatic resection of CRLM were retrospectively collected from June 2012 to May 2019. Treatment effects between AR and NAR were compared in full subgroup analyses. Tumor relapse-free survival (RFS) was evaluated by a stratified log-rank test and summarized with the use of Kaplan-Meier and Cox proportional hazards methods. RESULTS: Among 729 patients, 235 (32.2%) underwent AR and 494 (67.8%) underwent NAR. We showed favorable trends in RFS for AR compared with NAR in the patients with KRAS/NRAS/BRAF mutation (interaction P <0.001) or right-sidedness (interaction P <0.05). Patients who underwent AR had a markedly improved RFS compared with NAR in the cohorts of RAS/NRAS/BRAF mutation (median RFS 23.2 vs. 11.1 months, P <0.001) or right-sidedness (median RFS 31.6 vs. 11.5 months, P <0.001); upon the multivariable analyses, AR [gene mutation: hazard ratio (HR)=0.506, 95% CI=0.371-0.690, P <0.001; right-sidedness: HR=0.426, 95% CI=0.261-0.695, P =0.001) remained prognostic independently. In contrast, patients who underwent AR had a similar RFS compared with those who underwent NAR, in the cohorts of patients with gene wild-type tumors (median RFS 20.5 vs. 21.6 months, P =0.333). or left-sidedness (median RFS 15.8 vs. 19.5 months, P =0.294). CONCLUSIONS: CRLM patients with gene mutation or right-sidedness can benefit more from AR rather than from NAR.

Preoperative chemotherapy prior to primary tumour resection for asymptomatic synchronous unresectable colorectal liver-limited metastases: The RECUT multicenter randomised controlled trial.

PURPOSE: Primary tumour resection (PTR) is still a selection for patients with low tumour burden and good condition, especially with conversion therapy purpose for colorectal liver-limited metastases (CRLMs). The objective was to evaluate whether pre-PTR chemotherapy could improve progression-free survival (PFS) for patients with asymptomatic synchronous unresectable CRLMs. PATIENTS AND METHODS: Patients with asymptomatic synchronous unresectable CRLMs were randomly assigned to receive pre-PTR chemotherapy (arm A) or upfront PTR (arm B). Chemotherapy regimens of mFOLFOX6 plus cetuximab, mFOLFOX6 plus bevacizumab or mFOLFOX6 alone were chosen according to the RAS genotype. The primary end-point was PFS; secondary end-points included overall survival (OS), tumour response, disease control rate (DCR), liver metastases resection rate, surgical complications and chemotherapy toxicity. RESULTS: Three hundred and twenty patients were randomly assigned to arm A (160 patients) and arm B (160 patients). Patients in arm A had significantly improved the median PFS compared with arm B (10.5 versus 9.1 months; P = 0.013). Patients in arm A also had significantly better DCR (84.4% versus 75.0%; P = 0.037). The median OS (29.4 versus 27.2 months; P = 0.058), objective response rate (ORR) (53.1% versus 45.0%; P = 0.146) and liver metastases resection rate (21.9% versus 18.1%; P = 0.402) were not significantly different. The Clavien-Dindo 3-4 complications post PTR (4.5% versus 3.8%, P = 0.759) and the incidence of grade 3/4 chemotherapy events (42.2% versus 40.4%, P = 0.744) reached no statistical significance. CONCLUSIONS: For asymptomatic synchronous unresectable CRLMs, Pre-PTR chemotherapy improved the PFS compared with upfront PTR.

Whole-exome sequencing reveals the metastatic potential of hepatocellular carcinoma from the perspective of tumor and circulating tumor DNA.

BACKGROUND: Relapse of hepatocellular carcinoma (HCC) due to vascular invasion is common, but the genomic mechanisms remain unclear, and molecular determinants of high-risk relapse cases are lacking. We aimed to reveal the evolutionary trajectory of microvascular invasion (MVI) and develop a predictive signature for relapse in HCC. METHODS: Whole-exome sequencing was performed on tumor and peritumor tissues, portal vein tumor thrombus (PVTT), and circulating tumor DNA (ctDNA) to compare the genomic profiles between 5 HCC patients with MVI and 5 patients without MVI. We conducted an integrated analysis of exome and transcriptome to develop and validate a prognostic signature in two public cohorts and one cohort from Zhongshan Hospital, Fudan University. RESULTS: Shared genomic landscapes and identical clonal origins among tumor, PVTT, and ctDNA were observed in MVI ( +) HCC, suggesting that genomic changes favoring metastasis occur at the primary tumor stage and are inherited in metastatic lesions and ctDNA. There was no clonal relatedness between the primary tumor and ctDNA in MVI ( - ) HCC. HCC had dynamic mutation alterations during MVI and exhibited genetic heterogeneity between primary and metastatic tumors, which can be comprehensively reflected by ctDNA. A relapse-related gene signature named RGSHCC was developed based on the significantly mutated genes associated with MVI and shown to be a robust classifier of HCC relapse. CONCLUSIONS: We characterized the genomic alterations during HCC vascular invasion and revealed a previously undescribed evolution pattern of ctDNA in HCC. A novel multiomics-based signature was developed to identify high-risk relapse populations.

Perioperative and oncologic outcomes of laparoscopic versus open liver resection for combined hepatocellular-cholangiocarcinoma: a propensity score matching analysis.

BACKGROUND: Laparoscopic liver resection (LLR) has now been established as a safe and minimally invasive technique that is deemed feasible for treating hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). However, the role of LLR in treating combined hepatocellular-cholangiocarcinoma (cHCC-CC) patients has been rarely reported. This study aimed to assess the efficacy of LLR when compared with open liver resection (OLR) procedure for patients with cHCC-CC. METHODS: A total of 229 cHCC-CC patients who underwent hepatic resection (34 LLR and 195 OLR patients) from January 2014 to December 2018 in Zhongshan Hospital, Fudan University were enrolled and underwent a 1:2 propensity score matching (PSM) analysis between the LLR and OLR groups to compare perioperative and oncologic outcomes. Overall survival (OS) and recurrence-free survival (RFS) parameters were assessed by the log-rank test and the sensitivity analysis. RESULTS: A total of 34 LLR and 68 OLR patients were included after PSM analysis. The LLR group displayed a shorter postoperative hospital stay (6.61 vs. 8.26 days; p value < 0.001) when compared with the OLR group. No significant differences were observed in the postoperative complications' incidence or a negative surgical margin rate between the two groups (p value = 0.409 and p value = 1.000, respectively). The aspartate aminotransferase (AST), alanine aminotransferase (ALT), and inflammatory indicators in the LLR group were significantly lower than those in the OLR group on the first and third postoperative days. Additionally, OS and RFS were comparable in both the LLR and OLR groups (p value = 0.700 and p value = 0.780, respectively), and similar results were obtained by conducting a sensitivity analysis. CONCLUSION: LLR can impart less liver function damage, better inflammatory response attenuation contributing to a faster recovery, and parallel oncologic outcomes when compared with OLR. Therefore, LLR can be recommended as a safe and effective therapeutic modality for treating selected cHCC-CC patients, especially for those with small tumors in favorable location.

CYP1B1 promotes colorectal cancer liver metastasis by enhancing the growth of metastatic cancer cells via a fatty acids-dependent manner.

Background: Liver metastasis (LM) accounts for most colorectal cancer (CRC)-related deaths. However, how metastatic CRC cells gain the ability to survive and grow in liver remains largely unknown. Methods: First, we screened differentially expressed genes (DEGs) between LM and paired primary tumors (PTs) in Gene Expression Omnibus (GEO) database, and identified cytochrome P450 1B1 (CYP1B1) as the only common differential gene. Then, we verified messenger RNA (mRNA) and protein expression level in clinical specimens. After constructing stable up-regulated CYP1B1 versions of HCT116 and RKO CRC cells and stable down-regulated CYP1B1 versions of SW480 and HT29 CRC cells, cell proliferation assays, subcutaneous tumor formation, and mouse LM models were used to comprehend its function. Next, we used RNA-seq to uncover specific mechanisms of growth; cell cycle, polymerase chain reaction (PCR), western blot (WB) and GEO series (GSE) datasets were used to verify its mechanism. Last, gas chromatography tandem mass spectrometry (GC-MS/MS) was adopted to examine which fatty acids were changed. Results: A significantly higher level of CYP1B1 was found in LM than in PT in paired clinical CRC LM samples (P<0.05). After CYP1B1 overexpression in HCT116 and RKO cells, cell proliferation abilities in vitro and in vivo were enhanced; LM of NOD.Cg-PrkdcscidIl2rgem1Smoc (NSG) mice were enhanced. And knockdown of CYP1B1 in SW480 and HT29 cells, cell proliferation abilities in vitro and in vivo were reduced; LM of NSG mice were declined (P<0.05). RNA-seq showed 59 common genes from upregulated genes of RKO overexpression group and downregulated genes of SW480 knockdown group were enriched in cell cycle and DNA replication. Further investigation revealed CYP1B1 regulated alternation of MCM5, PCNA, and FEN1 genes, and G1/S transition in CRC cells. GC-MS/MS revealed long chain fatty acids (LCFAs) made a difference in SW480 knockdown group (P<0.05). Through adding LCFAs into SW480 and HT29 knockdown groups, cell proliferation abilities in vitro and in vivo were enhanced, and expressions of MCM5, PCNA, FEN1 were upregulated (P<0.05). Conclusions: CYP1B1 exerts a significant influence on LM of CRC by modulating tumor cell proliferation via "CYP1B1-LCFAs-G1/S transition". This finding suggests CYP1B1 could be a promising target for CRC LM.

Complement C5 is a novel biomarker for liver metastasis of colorectal cancer.

Background: Colorectal cancer (CRC) is one of the most prominent malignant diseases, with a high incidence and a dismal prognosis. Metastasis to the liver is the leading cause of death in CRC patients. This study aimed to identify accurate metastatic biomarkers of CRC and investigate the potential molecular mechanisms of liver metastasis of colorectal cancer (LMCRC). Methods: Three independent datasets were screened and downloaded from the Gene Expression Omnibus (GEO) database. The GEO2R tool was used to identify differentially expressed genes (DEGs) in CRC tissues and liver metastases. Next, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). Furthermore, the protein-protein interactions (PPIs) of the DEGs were analyzed using the Search Tool for the Retrieval of Interacting Genes (STRING) database, Cytoscape, and Molecular Complex Detection (MCODE). Next, the expression levels and Kaplan-Meier survival analysis of the target gene between normal colon and CRC tissues were performed by UALCAN. The expression of the target gene in tissues and cell lines was verified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry (IHC) assay. The impact of the target gene on the proliferation, invasion, and migration ability of COAD cells was explored in vitro. Results: A total of 92 common DEGs were found in the three independent datasets. GO/KEGG enrichment analysis showed that the DEGs were mainly involved in 14 different pathways. The protein-protein interaction (PPI) network revealed that complement 5 (C5), the upstream gene of C8A in the complement system, was associated with C8 and other key hub genes. Meanwhile, the online UALCAN resource showed that C5 was up-regulated and facilitated malignant progression in COAD samples. Next, we confirmed that C5 remarkably increased and promoted cell proliferation, migration, and invasion in CRC cell lines, SW620 and SW480. The IHC assay showed C5 was also highly expressed in a majority of LMCRC tissues compared with paired CRC tissues. Conclusions: The findings of our integrated bioinformatics study suggest that complement C5 might serve as a potential therapeutic target in patients with CRC.

A Novel mRNA Signature Related to Immunity to Predict Survival and Immunotherapy Response in Hepatocellular Carcinoma.

Background and Aims: Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the incidence and mortality rates are increasing. Given the limited treatments of HCC and promising application of immunotherapy for cancer, we aimed to identify an immune-related prognostic signature that can predict overall survival (OS) rates and immunotherapy response in HCC. Methods: The initial signature development was conducted using a training dataset from the Cancer Genome Atlas followed by independent internal and external validations from that resource and the Gene Expression Omnibus. A signature based nomogram was generated using multivariate Cox regression analysis. The associations of signature score with tumor immune phenotype and response to immunotherapy were analyzed using single-sample gene set enrichment analysis and tumor immune dysfunction and exclusion algorithm. A cohort from Zhongshan Hospital was employed to verify the predictive robustness of the signature regarding prognostic risk and immunotherapy response. Results: The prognostic signature, IGSHCC, consisting of 22 immune-related genes, had independent prognostic ability, with training and validation cohorts. Also, IGSHCC stratified HCC patients with different outcomes in subgroups. The prognostic accuracy of IGSHCC was better than three reported prognostic signatures. The IGSHCC-based nomogram had high accuracy and significant clinical benefits in predicting 3- and 5-year OS. IGSHCC reflected distinct immunosuppressive phenotypes in low- and high-score groups. Patients with low IGSHCC scores were more likely than those with high scores to benefit from immunotherapy. Conclusions: IGSHCC predicted HCC prognosis and response to immunotherapy, and contributed to individualized clinical management.

GTPBP4 promotes hepatocellular carcinoma progression and metastasis via the PKM2 dependent glucose metabolism.

Guanosine triphosphate binding protein 4 (GTPBP4) is a key regulator of cell cycle progression and MAPK activation. However, how its biological properties intersect with cellular metabolism in hepatocellular carcinoma (HCC) development remains poorly unexplained. Here, high GTPBP4 expression is found to be significantly associated with worse clinical outcomes in patients with HCC. Moreover, GTPBP4 upregulation is paralleled by DNA promoter hypomethylation and regulated by DNMT3A, a DNA methyltransferase. Additionally, both gain- and loss-of-function studies demonstrate that GTPBP4 promotes HCC growth and metastasis in vitro and in vivo. Mechanically, GTPBP4 can induce dimeric pyruvate kinase M2 (PKM2) formation through protein sumoylation modification to promote aerobic glycolysis in HCC. Notably, active GTPBP4 facilitates SUMO1 protein activation by UBA2, and acts as a linker bridging activated SUMO1 protein and PKM2 protein to induce PKM2 sumoylation. Furthermore, SUMO-modified PKM2 relocates from the cytoplasm to the nucleus may also could contribute to HCC progression through activating epithelial-mesenchymal transition (EMT) and STAT3 signaling pathway. Shikonin, a PKM2-specific inhibitor, can attenuate PKM2 dependent HCC glycolytic reprogramming, growth and metastasis promoted by GTPBP4, which offers a promising therapeutic candidate for HCC patients. Our findings indicate that GTPBP4-PKM2 regulatory axis plays a vital role in promoting HCC proliferation as well as metastasis by aerobic glycolysis and offer a promising therapeutic target for HCC patients.

Case report: immunotherapy successfully treated brain metastasis in intrahepatic cholangiocarcinoma and literature review.

Brain metastasis from intrahepatic cholangiocarcinoma (iCCA) is extremely rare, and no standard therapeutic strategy has been established. Camrelizumab is a programmed cell death protein 1 (PD-1) inhibitor that has been widely studied in treating liver cancer. Combined immunotherapy and targeted therapy are a promising approach for treating advanced iCCA. Despite that immune checkpoint inhibitor (ICI)-based neoadjuvant therapy on iCCA has shown a significant response rate and resection rate, few reports have shown the therapeutic efficacy of immunotherapy in treating brain metastasis from iCCA. Although PD-1 inhibitors such as pembrolizumab, nivolumab, or camrelizumab are increasingly applied in clinic practice to treat multiple malignancies, to the best of our knowledge, we report the first case of an iCCA patient with brain metastasis successfully treated with a combined immunotherapy and targeted therapy. The patient is a 54-year-old man with metastatic iCCA in brain treated though camrelizumab plus lenvatinib therapy with a complete response (CR). By the time of writing, he has had a progression-free survival of 17.5 months and did not experience any severe side effects related to this therapy. Camrelizumab plus lenvatinib therapy showed favorable efficacy and manageable toxicity for this patient with advanced iCCA and could be of interest for more prospective randomized trials to further verify the potential clinical benefits.

Tumor-derived PD1 and PD-L1 could promote hepatocellular carcinoma growth through autophagy induction in vitro.

BACKGROUNDS: Autophagy in tumor was also found to influence immune microenvironment. The relation between autophagy and cancer intrinsic PD1 and PD-L1 expression was not clear. METHODS: With data from TCGA and GTEx databases, mRNA expression levels of autophagy-related genes were compared between tumor samples and normal tissues, which were also correlated with survival status. Expression of autophagy-related genes were also associated with clinical traits in datasets of GSE14520 and ICGC LIRI. Single sample gene set enrichment analysis (ssGSEA) was used to calculate autophagy scores in tumor samples, using signatures from MSigDB database. Lentivirus (PD1 and PD-L1), siRNA (ATG13) and plasmids (LC3A/B) were used to target specific genes in tumor cells; Western blot was used to examine protein expression accordingly. Co-immunoprecipitation was performed to find PD1 or PD-L1 interacting proteins; colony formation and EdU analysis were used to evaluate tumor cell growth abilities. RESULTS: mRNA levels of autophagy markers were increased in tumor and correlated with worse survival of cancer patients. In hepatocellular carcinoma (HCC), high mRNA expression of autophagy markers was related to poor clinical status; increasing LC3 expression in HCC cell lines could promote tumor growth. Tumor intrinsic PD1 or PD-L1 were related to higher autophagy levels in specific tumor types; over-expression of PD1 or PD-L1 could increase autophagy in tumor cells through ATG13 interaction. CONCLUSION: Autophagy could promote tumor growth in specific cancer types. Tumor intrinsic PD1 or PD-L1 could both increase autophagy through ATG13 interaction.

PARG inhibition limits HCC progression and potentiates the efficacy of immune checkpoint therapy.

BACKGROUND & AIMS: Although the treatment of hepatocellular carcinoma (HCC) has been revolutionized by the advent of effective systemic therapies, the prognosis of patients with HCC remains dismal. Herein, we examined the pathophysiological role of PARG and assessed the utility of targeting dePARylation for HCC therapy. METHODS: The oncogenic function of PARG was evaluated in 2 orthotopic xenograft models and a Pargflox/flox mice model. The therapeutic efficacy of PARG inhibitors in combination with an anti-PD-1 antibody were assessed in murine orthotopic models. Microarray analysis was used to evaluate the pathological relevance of the PARG/DDB1/c-Myc/MMR axis. RESULTS: High PARG expression was strongly associated with poor HCC prognosis. Hepatocyte-specific PARG deletion significantly impaired liver tumorigenesis. PARG promoted HCC growth and metastasis through DDB1-dependent modulation of c-Myc. Specifically, PARG dePARylated DDB1 and consequently promoted DDB1 autoubiquitination, thus stabilizing the c-Myc protein in HCC cells. PARG downregulation attenuated c-Myc-induced MMR expression and PARG deficiency was correlated with a favorable prognosis in patients with HCC treated with anti-PD-1-based immunotherapy. In addition, PARG inhibitors could act in synergy with anti-PD-1 antibodies in orthotopic mouse models. CONCLUSIONS: PARG can act as an oncogene in HCC by modulating PARG/DDB1/c-Myc signaling and could be used as a biomarker to identify patients with HCC who may benefit from anti-PD-1 treatment. Our findings suggest that co-inhibition of PARG and PD-1 is an effective novel combination strategy for patients with HCC. LAY SUMMARY: The increase in deaths due to hepatocellular carcinoma (HCC) is a growing concern, with the mechanisms responsible for HCC development still incompletely understood. Herein, we identify a novel mechanism by which the protein PARG contributes to HCC development. Inhibition of PARG increased the efficacy of anti-PD-1 therapy (a type of immunotherapy) in HCC. These findings support the future clinical development of PARG inhibitors, potentially in combination with anti-PD-1 inhibitors.

PNOC Expressed by B Cells in Cholangiocarcinoma Was Survival Related and LAIR2 Could Be a T Cell Exhaustion Biomarker in Tumor Microenvironment: Characterization of Immune Microenvironment Combining Single-Cell and Bulk Sequencing Technology.

Background: Cholangiocarcinoma was a highly malignant liver cancer with poor prognosis, and immune infiltration status was considered an important factor in response to immunotherapy. In this investigation, we tried to locate immune infiltration related genes of cholangiocarcinoma through combination of bulk-sequencing and single-cell sequencing technology. Methods: Single sample gene set enrichment analysis was used to annotate immune infiltration status in datasets of TCGA CHOL, GSE32225, and GSE26566. Differentially expressed genes between high- and low-infiltrated groups in TCGA dataset were yielded and further compressed in other two datasets through backward stepwise regression in R environment. Single-cell sequencing data of GSE138709 was loaded by Seurat software and was used to examined the expression of infiltration-related gene set. Pathway changes in malignant cell populations were analyzed through scTPA web tool. Results: There were 43 genes differentially expressed between high- and low-immune infiltrated patients, and after further compression, PNOC and LAIR2 were significantly correlated with high immune infiltration status in cholangiocarcinoma. Through analysis of single-cell sequencing data, PNOC was mainly expressed by infiltrated B cells in tumor microenvironment, while LAIR2 was expressed by Treg cells and partial GZMB+ CD8 T cells, which were survival related and increased in tumor tissues. High B cell infiltration levels were related to better overall survival. Also, malignant cell populations demonstrated functionally different roles in tumor progression. Conclusion: PNOC and LAIR2 were biomarkers for immune infiltration evaluation in cholangiocarcinoma. PNOC, expressed by B cells, could predict better survival of patients, while LAIR2 was a potential marker for exhaustive T cell populations, correlating with worse survival of patients.

High serum gamma-glutamyl transpeptidase concentration associates with poor postoperative prognosis of patients with hepatitis B virus-associated intrahepatic cholangiocarcinoma.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) caused by chronic hepatitis B virus (HBV) infection has become prominent. Prospectively stratifying postoperative risk factors is a challenging task. METHODS: We retrospectively assessed the relationship between serum gamma-glutamyl transpeptidase (GGT) concentration and postoperative outcomes in 107 subjects with HBV-associated ICC. Cox proportionate hazard models and subgroup analyses were used to test the hypothesis with adjustment for potential confounders. RESULTS: Serum GGT concentration was negatively correlated with postoperative outcomes. For a 1-standard deviation (per-SD) (117 µ/L) increase of serum GGT concentration, the relative risk (RR) for overall survival (OS) and time to recurrence (TTR) were 1.72 [95% confidence interval (CI), 1.37 to 2.16] and 1.53 (95% CI, 1.22 to 1.91), respectively. In addition, the RRs of middle and top tertiles of GGT for death were 1.81 (95% CI, 0.98 to 3.32) and 3.56 (95% CI, 1.97 to 6.42), respectively (P for trend <0.001). Similarly, the RRs for recurrence of the corresponding tertiles were 1.70 (95% CI, 0.93 to 3.10) and 3.27 (95% CI, 1.77 to 6.06), respectively (P for trend =0.002). In our study, the negative correlation between serum GGT levels and OS did not differ significantly between groups stratified by age, sex, HBV DNA level, carbohydrate antigen 19-9 (CA19-9) level and liver resection type (all P for interaction >0.05); however, there was a significant interactive effect of serum GGT and adjuvant chemotherapy on OS (RR =0.64 vs. 1.77, P for interaction =0.04). CONCLUSIONS: High serum GGT concentration is associated with an increased risk of postoperative death and tumor recurrence in patients with HBV-associated ICC. However, this relationship became less significant with the implementation of adjuvant chemotherapy.

GOLM1 upregulates expression of PD-L1 through EGFR/STAT3 pathway in hepatocellular carcinoma.

GOLM1, a type II transmembrane protein, is associated with tumor progression, metastasis and immunosuppression. However, the relationship between GOLM1 and the immunosuppressive molecule PD-L1 in HCC remains largely unclear. Here, we revealed that GOLM1 acts as a novel positive regulator of PD-L1, whose abnormal expression plays a crucial role in cancer immune evasion and progression. We found that GOLM1 is overexpressed and positively correlated with PD-L1 expression in HCC. Mechanistically, we found that GOLM1 promotes the phosphorylation of STAT3 by enhancing the level of EGFR, which in turn upregulates the transcriptional expression of PD-L1. Taken together, we demonstrated that GOLM1 acts as a positive regulator of PD-L1 expression via the EGFR/STAT3 signaling pathway in human HCC cells. This study provides a new insight into the regulatory mechanism of PD-L1 expression in HCC, which may provide a novel therapeutic target for HCC immunotherapy.

Adjuvant apatinib treatment after resection of hepatocellular carcinoma with portal vein tumor thrombosis: a phase II trial.

BACKGROUND: Survival after resection of hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) still remains poor. Apatinib, a vascular endothelial cell growth factor receptor 2 inhibitor, has been shown to be safe and effective in patients with advanced HCC, so in the present study its efficacy and safety in the adjuvant setting was explored. METHODS: In this single-center, open-label phase II trial, the patients received apatinib (500 mg/day) until they experienced disease recurrence or intolerable toxicity. The primary endpoint was recurrence-free survival (RFS); the secondary endpoints included overall survival (OS) and safety. RESULTS: From a total of 49 patients who were screened between August 2017 and December 2018, 30 study participants received apatinib. According to the Liver Cancer Study Group of Japan classification of PVTT, there were 7, 11, and 12 participants with Vp1, Vp2, and Vp3, respectively. The median duration of treatment was 4.8 months [interquartile range (IQR): 2.0-8.8], and the median dose of apatinib was 339.7 mg/day (IQR: 267.7-500 mg/day). The median follow-up was 14.3 months (IQR: 12.3-19.3). The median RFS was 7.6 months [95% confidence interval (CI): 5.7-9.5 months]. The 1-year RFS rate and the 1-year OS rate were 36.1% and 93.3%, respectively. A total of 29 (96.7%) patients experienced adverse events, and 14 (46.7%) had grade 3 or 4 adverse events. No treatment-related deaths occurred. CONCLUSIONS: Apatinib was well tolerated in patients after resection of HCC with PVTT. The median RFS in this group was improved compared with that previously reported. TRIAL REGISTRATION: No.: NCT03261791 (ClinicalTrials.gov).

Tumor Derived SIGLEC Family Genes May Play Roles in Tumor Genesis, Progression, and Immune Microenvironment Regulation.

BACKGROUND: SIGLEC family genes can also be expressed on tumor cells in different cancer types, and though it has been found that SIGLEC genes expressed by immune cells can be exploited by tumors to escape immune surveillance, functions of tumor derived SIGLEC expression in tumor microenvironment (TME) were barely investigated, which could play roles in cancer patients' survival. METHODS: Using bioinformatic analysis, mutation status of SIGLEC family genes was explored through the cBioPortal database, and expression of them in different tumors was explored through the UALCAN database. The GEPIA database was used to compare SIGLEC family genes' mRNA between cancers and to generate a highly correlated gene list in tumors. A KM-plotter database was used to find the association between SIGLEC genes and survival of patients. The associations between SIGLEC family genes' expression, immune infiltration, and immune regulators' expression in TME were generated and examined by the TIMER 2.0 database; the differential fold changes of SIGLEC family genes in specific oncogenic mutation groups of different cancer types were also yielded by TIMER 2.0. The networks of SIGLEC family genes and highly correlated genes were constructed by the STRING database, and gene ontology and pathway annotation of SIGLEC family highly correlated genes were performed through the DAVID database. RESULTS: SIGLEC family genes were highly mutated and amplified in melanoma, endometrial carcinoma, non-small cell lung cancer, bladder urothelial carcinoma, and esophagogastric adenocarcinoma, while deep deletion of SIGLEC family genes was common in diffuse glioma. Alteration of SIGLEC family genes demonstrated different levels in specific tumors, and oncogenic mutation in different cancer types could influence SIGLEC family genes' expression. Most SIGLEC family genes were related to patients' overall survival and progression free survival. Also, tumor derived SIGLEC family genes were related to tumor immune cell infiltration and may regulate TME by influencing chemokine axis. CONCLUSION: Our computational analysis showed SIGLEC family genes expressed by tumor cells were associated with tumor behaviors, and they may also influence TME through chemokine axis, playing vital roles in patients' survival. Further experiments targeting tumor derived SIGLEC family genes are needed to confirm their influences on tumor growth, metastasis, and immune environment regulation.