Laparoscopic versus open surgery in treating patients with gallbladder cancer: a systematic review and meta-analysis.

Background: Concerns over the security of laparoscopic radical operation for gallbladder cancer (GBC) persist. This systematic review and meta-analysis attempted to compare the safety and efficacy of laparoscopic surgery (LS) versus open surgery (OS) in the treatment of GBC. Methods: The PubMed, EMBASE, and Web of Science were searched from inception to July 18, 2022. Literature search, quality assessment, and data extraction were completed independently and in duplicate. Effect-size estimates expressed as weighted mean difference (WMD) or odds ratio (OR) with 95% confidence interval (CI) were derived under the random-effects model. Results: A total of 27 independent studies including 2,868 participants were meta-analyzed. Significance was noted for intraoperative blood loss (WMD: -117.194, 95% CI: -170.188 to 64.201, P<0.001), harvested lymph nodes (WMD: -1.023, 95% CI: -1.776 to -0.269, P=0.008), postoperative hospital stay (WMD: -3.555, 95% CI: -4.509 to -2.601, P<0.001), postoperative morbidity (OR: 0.596, 95% CI: 0.407 to 0.871, P=0.008), overall survival rate at 2-year (OR: 1.524, 95% CI: 1.143 to 2.031, P=0.004), T2 survival at 1-year (OR: 1.799, 95% CI: 1.777 to 2.749, P<0.01) and 2-year (OR: 2.026, 95% CI: 1.392 to 2.949, P<0.001), as well as T3 survival at 1-year (OR: 2.669, 95% CI: 1.564 to 4.555, P<0.001) and 2-year (OR: 2.300, 95% CI: 1.308 to 4.046, P=0.004). Subgroup analyses revealed that ethnicity, incidental GBC, sample size, and follow-up period were possible sources of heterogeneity. There was a low probability of publication bias for all outcomes except postoperative morbidity. Conclusions: Our findings indicated that LS statistically had better 2-year survival rates, less intraoperative bleeding, shorter hospitalization times, and lower rates of complications than OS. However, the superiority and even the safety of LS still remain an open question due to the impact of incidental GBC, unaccounted heterogeneity, publication bias, lymph node dissection, and port-site metastasis.

In silico analysis unveiling potential biomarkers in gallbladder carcinogenesis.

Gallbladder cancer (GBC) is a rare but very aggressive most common digestive tract cancer with a high mortality rate due to delayed diagnosis at the advanced stage. Moreover, GBC progression shows asymptomatic characteristics making it impossible to detect at an early stage. In these circumstances, conventional therapy like surgery, chemotherapy, and radiotherapy becomes refractive. However, few studies reported some molecular markers like KRAS (Kirsten Rat Sarcoma) mutation, upregulation of HER2/neu, EGFR (Epidermal Growth Factor Receptor), and microRNAs in GBC. However, the absence of some specific early diagnostic and prognostic markers is the biggest hurdle for the therapy of GBC to date. The present study has been designed to identify some specific molecular markers for precise diagnosis, and prognosis, for successful treatment of the GBC. By In Silico a network-centric analysis of two microarray datasets; (GSE202479) and (GSE13222) from the Gene Expression Omnibus (GEO) database, shows 50 differentially expressed genes (DEGs) associated with GBC. Further network analysis revealed that 12 genes are highly interconnected based on the highest MCODE (Molecular Complex Detection) value, among all three genes; TRIP13 (Thyroid Receptor Interacting Protein), NEK2 (Never in Mitosis gene-A related Kinase 2), and TPX2 (Targeting Protein for Xklp2) having highest network interaction with transcription factors and miRNA suggesting critically associated with GBC. Further survival analysis data corroborate the association of these genes; TRIP13, NEK2, and TPX2 with GBC. Thus, TRIP13, NEK2, and TPX2 genes are significantly correlated with a greater risk of mortality, transforming them from mere biomarkers of the GBC for early detections and may emerge as prognostic markers for treatment.

Advanced gallbladder cancer with high tumor mutation burden: a case report and literature review.

Background: Gallbladder cancer (GBC) is a common malignant tumor of the biliary system. It is characterised by insidious onset, rapid progression and poor prognosis. Symptoms often indicate advanced or late-stage disease, with a 5-year survival rate of only 5-15%. Case Description: We present a case study of a patient with GBC who had a tumor mutation burden (TMB) of 32.5/MB (≥10 muts/MB). The patient received mFOLFIRINOX as first-line chemotherapy, which demonstrated significant efficacy. After stabilizing the disease, a sequential chemotherapy regimen was chosen. This regimen combined the immune checkpoint inhibitor (ICI) toripalimab (JS001), a humanised IgG4 monoclonal antibody targeting programmed cell death protein 1 (PD-1), with S-1 therapy, an oral fluoropyrimidine derivative. However, this treatment did not provide any significant clinical benefit for the patient. Therefore, we hypothesise that combining immunotherapy with chemotherapy may be more effective as a first line treatment for high-TMB advanced GBC. This hypothesis needs to be validated in large-scale clinical studies. Conclusions: In summary, mFOLFIRINOX is a safe and effective first-line chemotherapy regimen for advanced GBC. The timing of combining immunotherapy with chemotherapy requires careful consideration. Further clinical trials involving immunotherapy in advanced GBC are necessary to identify biomarkers that can guide clinical decisions.

Micro-RNAs With Prognostic Significance in Gallbladder Cancer: A Systematic Review and Meta-Analysis.

Gallbladder cancer (GBC) stands out as one of the most widespread malignancies impacting the biliary tract globally. Despite increasing interest, to the best of our knowledge, no meta-analysis has been undertaken to amalgamate the existing data concerning the prognostic significance of micro-RNAs (miRNAs) in GBC in comparison to studies on miRNAs in other cancers. Hence, this systematic review and meta-analysis aimed at determining the prognostic significance of miRNAs in GBC patients. Comprehensive literature searches were conducted across PubMed, Cochrane Library, Ovid, Scopus, and Science Direct databases. Studies that evaluated the association between miRNAs and overall survival in GBC patients were included. Random-effect meta-analysis was employed to pool hazard ratios (HRs) and their 95% confidence intervals (CIs) across studies. A total of 15 studies, encompassing 16 miRs, were included for our analysis. The pooled analysis revealed that a high expression of miR-204, miR-7-2-3p, miR-29c-3p, miR-125b, miR-20a, miR-139-5p, miR-141, miR-92b-3p, miR-335, and miR-372 was significantly associated with poor prognosis and increased risk (HR>1 and the upper bound of the 95% CI>1). Additionally, these miRNAs were associated with the overall survival (HR = 1.56, 95% CI = 0.91-2.20, I2 = 91.82%). Significant heterogeneity was observed and could be attributed to the limited number of studies available on the GBC and significant reliance on quantitative real-time PCR for the detection of miRNAs. In conclusion, specific miRNAs exhibit prognostic significance in GBC, with potential implications for patient stratification and targeted therapeutic interventions. However, due to the heterogeneity among studies, these findings should be interpreted cautiously and validated in larger cohorts.

Hepatic arterial infusion chemotherapy combined with bevacizumab plus a PD-1 inhibitor for gallbladder cancer with hepatic oligometastasis: a real-world study.

Background: Gallbladder cancer (GBC) is different from other biliary tract cancers in terms of molecular phenotype and microenvironment. Specific treatments for GBC need to be urgently explored. This study preliminarily investigated the clinical value of hepatic artery infusion chemotherapy (HAIC) combined with bevacizumab plus a programmed death receptor-1 (PD-1) inhibitor for treatment of GBC with hepatic oligometastasis. Methods: We retrospectively collected data on GBC patients with hepatic oligometastasis, who received this combination therapy. The clinical data, conversion rate, treatment response, adverse events (AEs), and short-term survival were summarized. The responses of primary gallbladder lesions and hepatic metastasis, and their effect on prognosis, were investigated. Results: A total of 27 patients were included in the analysis. No grade 4 AEs were observed. The overall objective response rate (ORR) was 55.6% and the disease control rate (DCR) was 85.2%. Median overall survival (OS) time was 15.0 months and the 1-year survival rate was 64.0%. Median progression-free survival (PFS) time was 7.0 months and the 1-year PFS rate was 16.2%. Six patients (22.2%) were successfully converted to resection. Compared with primary gallbladder lesions, it appeared more difficult for patients with hepatic metastasis to achieve remission (ORR: 40.7% vs. 77.8%; P=0.012), but its response appeared to be closely related to the prognosis [median OS: 16.0 months in the complete response (CR) or partial response (PR) group vs. 11.0 months in the stable disease (SD) or progressive disease (PD) group, P=0.070; median PFS: 12.0 months in the CR or PR group vs. 6.5 months in the SD or PD group, P<0.001]. Preoperative CA19-9 of >1,900 U/mL and >5 cm metastatic lesions were associated with an unsatisfactory response, whereas a significant decrease of 18F-fluorodeoxyglucose (18F-FDG) uptake may be a marker of tumor remission. Conclusions: The combination of HAIC, a PD-1 inhibitor, and bevacizumab shows potential for advanced GBC with hepatic oligometastasis. The therapeutic response of hepatic metastasis had a greater influence on prognosis than that of primary gallbladder lesions.

Volume electron microscopy reveals age-related ultrastructural differences of globular bush cell axons in mouse central auditory system.

In mammals, thick axonal calibers wrapped with heavy myelin sheaths are prevalent in the auditory nervous system. These features are crucial for fast traveling of nerve impulses with minimal attenuation required for sound signal transmission. In particular, the long-range projections from the cochlear nucleus - the axons of globular bush cells (GBCs) - to the medial nucleus of the trapezoid body (MNTB) are tonotopically organized. However, it remains controversial in gerbils and mice whether structural and functional adaptations are present among the GBC axons targeting different MNTB frequency regions. By means of high-throughput volume electron microscopy, we compared the GBC axons in full-tonotopy-ranged MNTB slices from the C57BL/6 mice at different ages. Our quantification reveals distinct caliber diameter and myelin profile of the GBC axons with endings at lateral and medial MNTB, arguing for modulation of functionally heterogeneous axon subgroups. In addition, we reported axon-specific differences in axon caliber, node of Ranvier, and myelin sheath among juvenile, adult, and old mice, indicating the age-related changes of GBC axon morphology over time. These findings provide structural insight into the maturation and degeneration of GBC axons with frequency tuning across the lifespan of mice.

Long non­coding RNAs in gallbladder cancer: From mechanisms to therapeutic opportunities (Review).

Due to the lack of specific symptoms, characteristic diagnostic markers and effective comprehensive treatment, gallbladder cancer (GBC) is currently considered one of the most malignant abdominal tumors. With the rapid development of biological technologies, long non­coding RNAs (lncRNAs), once regarded as transcriptional junk, have been demonstrated to participate in almost the whole process of the central dogma of molecular biology. The central dogma deals with the transfer of sequential information at the level of individual residues. LncRNAs have an effect on multiple cancer types. However, evidence of dysregulated lncRNA functions in GBC is limited. In the present review, the regulatory mechanisms of lncRNA function on gene expression were examined, including epigenetic modification, transcriptional regulation and post­translational modulation. These mechanisms are strongly associated with tumor development and metastasis. Next, it was summarized how lncRNAs affect GBC diverse malignant phenotypes through various mechanisms. Moreover, predictions of lncRNA interactions with other functional molecules in malignancies were made using several valuable databases, including crosstalk between lncRNA and DNA, mRNA, microRNA, and protein. Additionally, several potential therapeutic methods targeting pathological lncRNAs in tumors were identified. Finally, perspectives about lncRNA research and applications in GBC were presented in the current study, including viewpoints of coding potential of lncRNAs and feasible usage of micropeptides encoded by lncRNAs; roles of lncRNAs in tumor cell metabolic reprogramming and tumor microenvironment; and function of lncRNAs as possible biomarkers and therapeutic targets for improving GBC diagnosis, treatment and prognosis.

Clinical Significance of Frequently Down-Regulated Phosphatidylethanolamine-Binding Protein-1 in Gallbladder Cancer.

BACKGROUND: Promoter hypermethylation of tumor suppressor genes has been demonstrated to be one of the major mechanisms of their epigenetic regulation in various reports. We have studied the promoter methylation status of PEBP1 and evaluated its correlation with gallbladder carcinogenesis. AIMS: PEBP1, an endogenous inhibitor of Raf/MEK/ERK signaling pathway, is a tumor suppressor gene. We aimed to study the expression profile of PEBP1 and understand the mechanism and significance of its deregulation in gallbladder cancer. METHODS: PEBP1 expression analysis and its promoter methylation status were investigated in 77 gallbladder carcinoma (GBC) and tissue biopsies from 28 patients of gallstone disease by RT-PCR and MS-PCR, respectively. RESULTS: Our results of the mRNA expression profiling demonstrate that PEBP1 is down-regulated in 62.3% (48/77), while 31.2% (24/77) of the gallbladder cancer biopsies show no significant change and 6.5% (5/77) show up-regulated expression compared to tissue samples of gallstone diseases. In GBC, 48.1% (N = 37) GBC biopsy samples exhibited significantly heterozygous promoter hypermethylation compared to tissue samples from gallstone diseases which show promoter hypermethylation in 3 (10.7%) samples only. In gallbladder cancer, the PEBP1 methylation is significantly associated with lymph node metastasis and shorter period of survival. CONCLUSION: PEBP1 is frequently down-regulated and hypermethylated in gallbladder cancer and its promoter hypermethylation is a frequent and early inactivating mechanism in GBC.

Erratum: Preoperative immunological plasma markers TRAIL, CSF1, and TIE2 predict survival after resection for biliary tract cancer.

[This corrects the article DOI: 10.3389/fonc.2023.1169537.].

FASN promotes gallbladder cancer progression and reduces cancer cell sensitivity to gemcitabine through PI3K/AKT signaling.

Lipid metabolism plays an important role in the growth and development of tumors. However, the role of lipid metabolism in gallbladder cancer (GBC) has not been clearly clarified. Here, we demonstrated that fatty acid synthase (FASN), a key enzyme in de novo fatty acid biosynthesis, had upregulated expression in GBC samples both at protein and mRNA levels. Analysis of clinical data indicated the association between elevated FASN expression and poorer histology grades. Furthermore, FASN activity impairment through FASN knockdown or treatment with orlistat resulted in the inhibition of cell proliferation and migration, as well as increased sensitivity to gemcitabine. Both FASN knockdown and orlistat treatment induced cell apoptosis. Mechanistically, impairment of FASN activity suppressed the activation of the PI3K/AKT signaling pathway, which led to increased cell apoptosis and sensitivity to gemcitabine. These findings were also validated through nude mouse xenograft models, thus highlighting the potential of targeting FASN as a clinical treatment strategy. Collectively, the present study underscores the crucial role of FASN in the progression of gallbladder cancer via the PI3K/AKT pathway.

The potential role of miRNAs in the pathogenesis of gallbladder cancer - A focus on signaling pathways interplay.

microRNAs (also known as miRNAs or miRs) are a class of small non-coding RNAs that play a critical role in post-transcriptional gene regulation as negative gene regulators by binding complementary sequences in the 3'-UTR of target messenger RNAs (mRNAs) leading to translational repression and/or target degradation a wide range of genes and biological processes, including cell proliferation, invasion, migration, and apoptosis. The development and progression of cancer have been linked to the anomalous expression of miRNAs. According to recent studies, miRNAs have been found to regulate the expression of cancer-related genes through multiple signaling pathways in gallbladder cancer (GBC). Besides, miRNAs are implicated in several modulatory signaling pathways of GBC, including the Notch signaling pathway, JAK/STAT signaling pathway, protein kinase B (AKT), and Hedgehog signaling pathway. This review summarizes our current knowledge of the functions of miRNAs in the mechanisms underlying the pathogenic symptoms of GBC and illustrates their potential significance as treatment targets.

Preoperative immunological plasma markers TRAIL, CSF1 and TIE2 predict survival after resection for biliary tract cancer.

Introduction: Systemic inflammatory markers have been validated as prognostic factors for patients with biliary tract cancer (BTC). The aim of this study was to evaluate specific immunologic prognostic markers and immune responses by analyzing preoperative plasma samples from a large prospectively collected biobank. Methods: Expression of 92 proteins representing adaptive and innate immune responses was investigated in plasma from 102 patients undergoing resection for BTC 2009-2017 (perihilar cholangiocarcinoma n=46, intrahepatic cholangiocarcinoma n=27, gallbladder cancer n=29), by means of a high-throughput multiplexed immunoassay. Association with overall survival was analyzed by Cox regression, with internal validation and calibration. Tumor tissue bulk and single-cell gene expression of identified markers and receptors/ligands was analyzed in external cohorts. Results: Three preoperative plasma markers were independently associated with survival: TRAIL, TIE2 and CSF1, with hazard ratios (95% confidence intervals) 0.30 (0.16-0.56), 2.78 (1.20-6.48) and 4.02 (1.40-11.59) respectively. The discrimination of a preoperative prognostic model with the three plasma markers was assessed with concordance-index 0.70, while the concordance-index of a postoperative model with histopathological staging was 0.66. Accounting for subgroup differences, prognostic factors were assessed for each type of BTC. TRAIL and CSF1 were prognostic factors in intrahepatic cholangiocarcinoma. In independent cohorts, TRAIL-receptor expression was higher in tumor tissue and seen in malignant cells, with TRAIL and CSF1 expressed by intra- and peritumoral immune cells. Intratumoral TRAIL-activity was decreased compared to peritumoral immune cells, while CSF1-activity was increased. The highest CSF1 activity was seen in intratumoral macrophages, while the highest TRAIL-activity was seen in peritumoral T-cells. Discussion: In conclusion, three preoperative immunological plasma markers were prognostic for survival after surgery for BTC, providing good discrimination, even compared to postoperative pathology. TRAIL and CSF1, prognostic factors in intrahepatic cholangiocarcinoma, showed marked differences in expression and activity between intra- and peritumoral immune cells.

miRNAs orchestration of gallbladder cancer - Particular emphasis on diagnosis, progression and drug resistance.

Gallbladder cancer (GBC) is characterized by a highly invasive nature and a poor prognosis, with adenocarcinoma being the main histological subtype. According to statistical data, patients diagnosed with advanced GBC have a survival rate of less than 5% for 5 years. Despite the novel therapeutic techniques, the unsatisfactory results could be related to the underlying biology of tumor cells and resistance to chemotherapy. Early diagnosis is more important than clinical therapy as it assists in determining the pathological stage of cancer and facilitates the selection of appropriate medication. Hence, it is very important to understand the precise pathogenesis of GBC and to discover potential novel biomarkers for early diagnosis of GBC. Non-coding RNAs, such as microRNAs, long non-coding RNAs, and circular RNAs, have been found to influence the transcriptional regulation of target genes associated with cancer, either directly or indirectly. microRNAs are a group of small, non-coding, single-stranded RNAs that are expressed endogenously. miRNAs play significant roles in various fundamental cellular processes. Therefore, miRNAs have the potential to serve as valuable biomarkers and therapeutic targets for GBC.

Multi-clinical index classifier combined with AI algorithm model to predict the prognosis of gallbladder cancer.

Objectives: It is significant to develop effective prognostic strategies and techniques for improving the survival rate of gallbladder carcinoma (GBC). We aim to develop the prediction model from multi-clinical indicators combined artificial intelligence (AI) algorithm for the prognosis of GBC. Methods: A total of 122 patients with GBC from January 2015 to December 2019 were collected in this study. Based on the analysis of correlation, relative risk, receiver operator characteristic curve, and importance by AI algorithm analysis between clinical factors and recurrence and survival, the two multi-index classifiers (MIC1 and MIC2) were obtained. The two classifiers combined eight AI algorithms to model the recurrence and survival. The two models with the highest area under the curve (AUC) were selected to test the performance of prognosis prediction in the testing dataset. Results: The MIC1 has ten indicators, and the MIC2 has nine indicators. The combination of the MIC1 classifier and the "avNNet" model can predict recurrence with an AUC of 0.944. The MIC2 classifier and "glmet" model combination can predict survival with an AUC of 0.882. The Kaplan-Meier analysis shows that MIC1 and MIC2 indicators can effectively predict the median survival of DFS and OS, and there is no statistically significant difference in the prediction results of the indicators (MIC1: χ2 = 6.849, P = 0.653; MIC2: χ2 = 9.14, P = 0.519). Conclusions: The MIC1 and MIC2 combined with avNNet and mda models have high sensitivity and specificity in predicting the prognosis of GBC.

The oncogenic role of NF1 in gallbladder cancer through regulation of YAP1 stability by direct interaction with YAP1.

BACKGROUND: Gallbladder cancer (GBC) is the most prevalent and invasive biliary tract malignancy. As a GTPase-activating protein, Neurofibromin 1 (NF1) is a tumor suppressor that negatively regulates the RAS signaling pathway, and its abnormality leads to neurofibromatosis type 1 (NF-1) disease. However, the role of NF1 playing in GBC and the underlying molecular mechanism has not been defined yet. METHODS: A combination of NOZ and EH-GB1 cell lines as well as nude mice, were utilized in this study. mRNA expression and protein levels of NF1 and YAP1 were evaluated by quantitative real-time PCR (qRT-PCR), western blot (WB), and immunohistochemistry (IHC). In vitro and in vivo assays were performed to explore the biological effects of NF1 in NOZ and EH-GB1 cells via siRNA or lv-shRNA mediated knockdown. Direct interaction between NF1 and YAP1 was detected by confocal microscopy and co-immunoprecipitation (Co-IP), and further confirmed by GST pull-down assay and isothermal titration calorimetry assay (ITC). The stability of proteins was measured by western blot (WB) in the presence of cycloheximide. RESULTS: This study showed that a higher level of NF1 and YAP1 was found in GBC samples than in normal tissues and associated with worse prognoses. The NF1 knockdown impaired the proliferation and migration of NOZ in vivo and in vitro by downregulating YAP1 expression. Moreover, NF1 co-localized with YAP1 in NOZ and EH-GB1 cells, and the WW domains of YAP1 specifically recognized the PPQY motif of NF1. The structural modeling also indicated the hydrophobic interactions between YAP1 and NF1. On the other hand, YAP1 knockdown also impaired the proliferation of NOZ in vitro, phenocopying the effects of NF1 knockdown. Overexpression of YAP1 can partially rescue the impaired proliferation in NF1 stably knockdown cells. In mechanism, NF1 interacted with YAP1 and increased the stability of YAP1 by preventing ubiquitination. CONCLUSIONS: Our findings discovered a novel oncogenic function of NF1 by directly interacting with YAP1 protein and stabilizing YAP1 to protect it from proteasome degradation in NOZ cells. NF1 may serve as a potential therapeutic target in GBC.

Label-free surface-enhanced Raman spectroscopy of serum with machine-learning algorithms for gallbladder cancer diagnosis.

Gallbladder cancer (GBC) is a rare but frequently fatal biliary tract malignancy that is typically discovered when it is already advanced. In this study, we investigated a novel technique for the quick and non-invasive diagnosis of GBC based on serum surface-enhanced Raman spectroscopy (SERS). SERS spectra of serum from 41 patients with GBC and 72 normal subjects were recorded. Principal component analysis-linear discriminant analysis (PCA-LDA), and PCA-support vector machine (PCA-SVM), Linear SVM and Gaussian radial basis function-SVM (RBF-SVM) algorithms were used to establish the classification models, respectively. When the Linear SVM was used, the overall diagnostic accuracy for classifying the two groups could achieve 97.1%, and when RBF-SVM was used, the diagnostic sensitivity of GBC was 100%. The results demonstrated that SERS combination with a machine learning algorithm is a promising candidate to be one of the diagnostic tools for GBC in the future.

Case report: Preliminary response to tislelizumab plus S-1 in patients with metastatic gallbladder carcinoma: A report of five cases and a literature review.

Gallbladder cancer (GBC) and cholangiocarcinoma are common cancers of the biliary system and are associated with a poor prognosis. Surgery and chemotherapy provide limited benefit to patients with advanced biliary tract carcinoma. Novel immunotherapies and molecularly targeted therapies are more effective options; however, few patients benefit and drug resistance is a concern. Here, we report five cases of advanced GBC with either high programmed death-ligand 1 (PD-L1) expression or a high tumor mutation burden (TMB-H). The patients were treated with a combination therapy of tislelizumab and S-1. The tumors were effectively controlled in most patients. One patient developed immune-related pneumonia (irP) during treatment, which resolved after hormone therapy, and the patient underwent surgery. Tislelizumab and S-1 were administered again after surgery; however, recurrent irP required discontinuation, and the tumor progressed after drug withdrawal. These cases demonstrate that combined therapy of anti-programmed cell death protein-1 (PD-1) antibodies and S-1 is a safe and effective regimen with few side effects for GBC patients, especially for sensitive populations (patients with TMB-H, microsatellite instability, deficient mismatch repair, or high expression of PD-L1). To our knowledge, this is the first time that tislelizumab in combination with S-1 has been used to treat patients with advanced GBC.

YKL-40 derived from infiltrating macrophages cooperates with GDF15 to establish an immune suppressive microenvironment in gallbladder cancer.

Despite of the high lethality of gallbladder cancer (GBC), little is known regarding molecular regulation of the tumor immunosuppressive microenvironment. Here, we determined tumor expression levels of YKL-40 and the molecular mechanisms by which YKL-40 regulates escape of anti-tumor immune surveillance. We found that elevated expression levels of YKL-40 in plasma and tissue were correlated with tumor size, stage IV and lymph node metastasis. Single cell transcriptome analysis revealed that YKL-40 was predominantly derived from M2-like subtype of infiltrating macrophages. Blockade of M2-like macrophage differentiation of THP-1 cells with YKL-40 shRNA resulted in reprogramming to M1-like macrophages and restricting tumor development. YKL-40 induced tumor cell expression and secretion of growth differentiation factor 15 (GDF15), thus coordinating to promote PD-L1 expression mediated by PI3K, AKT and/or Erk activation. Interestingly, extracellular GDF15 inhibited intracellular expression of GDF15 that suppressed PD-L1 expression. Thus, YKL-40 disrupted the balance of pro- and anti-PD-L1 regulation to enhance expression of PD-L1 and inhibition of T cell cytotoxicity, leading to tumor immune evasion. The data suggest that YKL-40 and GDF15 could serve as diagnostic biomarkers and immunotherapeutic targets for GBC.

Prognostic Relevance of PDL1 and CA19-9 Expression in Gallbladder Cancer vs. Inflammatory Lesions.

Chronic inflammation in the gallbladder leading to persistent epithelium damage promotes invasive cancer. The study aimed to assess the prognostic value of PDL1 and CA19-9 markers in cancer/inflammatory lesions of the gallbladder. A total of 29 cases (19 cancer and 10 inflammatory) were included. The PDL1 protein concentration level and mRNA expression were assessed in the tissues' lysates by ELISA and real-time PCR, respectively. PDL1 and CA19-9 concentration levels were compared and statistically related with clinico-pathological variables. The PDL1 protein level and its relative mRNA expression were correlated. Kaplan-Meir survival and Cox regression analyses were conducted for predicting prognosis. This study investigated the PDL1 and CA19-9 marker expression in both cancer and inflammatory cases of the gallbladder (p = 0.48 and p = 0.17 respectively). PDL1 protein expression was significantly associated with the hormonal profile of the cases (p = 0.04) at an optimum cut-off value of 13 pg/mL, while the CA19-9 marker expression was correlated with the status of liver metastasis (p = 0.0043) and size of the tumor (p = 0.004). A low PDL1 concentration was found when compared to the CA19-9 level among cancer cases (p = 0.12) and proportional in the inflammatory lesions (p = 0.63). A significant positive correlation was found between the PDL1 protein and its relative mRNA expressions in the inflammatory lesions (p = 0.029) when compared to cancer cases (p = 0.069). Our results showed that a protein-based assay for PDL1 expression would be more sensitive compared to RNA based assays for GBC risk stratifications. Overall survival was predicted with CA19-9 and PDL1 levels (p = 0.0074, p = 0.23, respectively). PDL1 and CA19-9 may act as a probable predictor of a poor prognosis in gallbladder cancer (GBC) cases.