Genomic ERBB2/ERBB3 mutations promote PD-L1-mediated immune escape in gallbladder cancer: a whole-exome sequencing analysis

Mining of RNA Methylation-Related Genes and Elucidation of Their Molecular Biology in Gallbladder Carcinoma

Gallbladder carcinoma (GBC), which has high invasion and metastasis risks, remains the most common biliary tract malignancy. Surgical resection for GBC is the only effective treatment, but most patients miss the opportunity for curative surgery because of a lack of timely diagnosis. The aim of this study was to identify and verify early candidate diagnostic and prognostic RNA methylation related genes for GBC via integrated transcriptome bioinformatics analysis. Lists of GBC-related genes and methylation-related genes were collected from public databases to screen differentially expressed genes (DEGs) by using the limma package and the RobustRankAggreg (RRA) package. The core genes were collected with batch effects corrected by the RRA algorithm through protein interaction network analysis, signaling pathway enrichment analysis and gene ranking. Four modules obtained from four public microarray datasets were found to be related to GBC, and FGA, F2, HAO1, CFH, PIPOX, ITIH4, GNMT, MAT1A, MTHFD1, HPX, CTH, EPHX2, HSD17B6, AKR1C4, CFHR3, ENNP1, and NAT2 were revealed to be potential hub genes involved in methylation-related pathways and bile metabolism-related pathways. Among these, FGA, CFH, F2, HPX, and PIPOX were predicted to be methylated genes in GBC, but POPIX had no modification sites for RNA methylation. Furthermore, survival analysis of TCGA (the Cancer Genome Atlas) database showed that six genes among the hub genes, FGA, CFH, ENPP1, CFHR3, ITIH4, and NAT2, were highly expressed and significantly correlated with worse prognosis. Gene correlation analysis revealed that the FGA was positively correlated with the ENPP1, NAT2, and CFHR3, while CFH was positively correlated with the NAT2, CFHR3, and FGA. In addition, the results of immunohistochemistry (IHC) showed that the expressions of FGA, F2, CFH, PIPOX, ITIH4, GNMT, MAT1A, MTHFD1, HPX, CFHR3, NAT2, and ENPP1 were higher in GBC tissues than that in control tissues. In conclusion, two genes, FGA and CFH, were identified as RNA methylation-related genes also involved in bile metabolism in GBC, which may be novel biomarkers to early diagnose and evaluate prognosis for GBC.

Whole-exome mutational landscape of neuroendocrine carcinomas of the gallbladder

Neuroendocrine carcinoma (NEC) of the gallbladder (GB-NEC) is a rare but extremely malignant subtype of gallbladder cancer (GBC). The genetic and molecular signatures of GB-NEC are poorly understood; thus, molecular targeting is currently unavailable. In the present study, we applied whole-exome sequencing (WES) technology to detect gene mutations and predicted somatic single-nucleotide variants (SNVs) in 15 cases of GB-NEC and 22 cases of general GBC. In 15 GB-NECs, the C > T mutation was predominant among the 6 types of SNVs. TP53 showed the highest mutation frequency (73%, 11/15). Compared with neuroendocrine carcinomas of other organs, significantly mutated genes (SMGs) in GB-NECs were more similar to those in pulmonary large-cell neuroendocrine carcinomas (LCNECs), with driver roles for TP53 and RB1. In the COSMIC database of cancer-related genes, 211 genes were mutated. Strikingly, RB1 (4/15, 27%) and NAB2 (3/15, 20%) mutations were found specifically in GB-NECs; in contrast, mutations in 29 genes, including ERBB2 and ERBB3, were identified exclusively in GBC. Mutations in RB1 and NAB2 were significantly related to downregulation of the RB1 and NAB2 proteins, respectively, according to immunohistochemical (IHC) data (p values = 0.0453 and 0.0303). Clinically actionable genes indicated 23 mutated genes, including ALK, BRCA1, and BRCA2. In addition, potential somatic SNVs predicted by ISOWN and SomVarIUS constituted 6 primary COSMIC mutation signatures (1, 3, 30, 6, 7, and 13) in GB-NEC. Genes carrying somatic SNVs were enriched mainly in oncogenic signaling pathways involving the Notch, WNT, Hippo, and RTK-RAS pathways. In summary, we have systematically identified the mutation landscape of GB-NEC, and these findings may provide mechanistic insights into the specific pathogenesis of this deadly disease.

Biliary tract cancer

Biliary tract cancers, including intrahepatic, perihilar, and distal cholangiocarcinoma as well as gallbladder cancer, are low-incidence malignancies in most high-income countries, but represent a major health problem in endemic areas; moreover, the incidence of intrahepatic cholangiocarcinoma is rising globally. Surgery is the cornerstone of cure; the optimal approach depends on the anatomical site of the primary tumour and the best outcomes are achieved through management by specialist multidisciplinary teams. Unfortunately, most patients present with locally advanced or metastatic disease. Most studies in advanced disease have pooled the various subtypes of biliary tract cancer by necessity to achieve adequate sample sizes; however, differences in epidemiology, clinical presentation, natural history, surgical therapy, response to treatment, and prognosis have long been recognised. Additionally, the identification of distinct patient subgroups harbouring unique molecular alterations with corresponding targeted therapies (such as isocitrate dehydrogenase-1 mutations and fibroblast growth factor receptor-2 fusions in intrahepatic cholangiocarcinoma, among others) is changing the treatment paradigm. In this Seminar we present an update of the causes, diagnosis, molecular classification, and treatment of biliary tract cancer.

Gastric Cancer Harboring an ERBB3 Mutation Treated with a Pyrotinib-Irinotecan Combo: A Case Study

Gastric cancer is common, especially in East Asian countries, and is associated with high recurrence and mortality rates. Currently, there is no standard third-line treatment for metastatic gastric cancer. In this report, we present the case of a 69-year-old man with advanced gastric cancer, whose tumor was negative for human epidermal growth factor receptor 2 (HER2) according to immunohistochemical analysis. Next-generation sequencing performed on paraffin sections of the postoperative tumor samples indicated the presence of the ERBB3 V104L mutation. The patient received irinotecan plus pyrotinib as a third-line therapy and achieved a progression-free survival of 7.6 months with a high quality of life. Therefore, the combined administration of irinotecan and pyrotinib may improve the clinical condition of patients with gastric cancer harboring an ERBB3 mutation. Moreover, ERBB3 could be a potential therapeutic target for gastric cancer.

KIF11 promotes cell proliferation via ERBB2/PI3K/AKT signaling pathway in gallbladder cancer

Proliferation is one of the significant hallmarks of gallbladder cancer, which is a relatively rare but fatal malignance. Aim of this study was to examine the biological impact and molecular mechanism of the candidate hub-gene on the proliferation and tumorigenesis of gallbladder cancer. We analyzed the differentially expressed genes and the correlation between these genes with MKI67, and showed that KIF11 is one of the major upregulated regulators of proliferation in gallbladder cancer (GBC). The Gene Ontology, Gene Sets Enrichment Analysis and KEGG Pathway analysis indicated that KIF11 may promote GBC cell proliferation through the ERBB2/PI3K/AKT signaling pathway. Gain-of-function and loss-of-function assay demonstrated that KIF11 regulated GBC cell cycle and cancer cell proliferation in vitro. GBC cells exhibited G2M phase cell cycle arrest, cell proliferation and clone formation ability reduction after treatment with Monastrol, a specific inhibitor of KIF11. Xenograft model showed that KIF11 promotes GBC growth in vivo. Rescue experiments showed that KIF11-induced GBC cell proliferation dependented on ERBB2/PI3K/AKT pathway. Moreover, we found that H3K27ac signals are enriched among the promoter region of KIF11 in the UCSC Genome Browser Database. Differentially expressed analysis showed that EP300, a major histone acetyltransferase modifying H3K27ac signal, is highly expressed in gallbladder cancer and correlation analysis illustrated that EP300 is positively related with KIF11 in almost all the cancer types. We further found that KIF11 was significantly downregulated in a dose-dependent and time-dependent manner after histone acetylation inhibitor treatment. The present results highlight that high KIF11 expression promotes GBC cell proliferation through the ERBB2/PI3K/AKT signaling pathway. The findings may help deepen our understanding of mechanism underlying GBC cancer development and development of novel diagnostic and therapeutic target.

Immunotherapies in clinical development for biliary tract cancer

Introduction: Cancers of the biliary tract (BTC) are aggressive malignancies with limited treatment options and an overall dismal prognosis. In recent years, two concepts, namely precision oncology and immune oncology (IO) have profoundly influenced and, in some cancers, even revolutionized tumor treatments. While positive data from randomized trials have led to the incorporation of targeted concepts for genetically select BTC patients, IO is not yet implemented in clinical practice.Areas covered: We discuss published results from completed, as well as from ongoing studies on IO in BTC, based on a literature search on Pubmed and information provided by clinicaltrials.gov in October 2020. Apart from monotherapy, we outline IO-based combination approaches and highlight pivotal studies whose results will likely influence the future development of relevant concepts in BTC.Expert opinion: Despite partially positive signals, IO thus far disappointed in unselected BTC populations and should currently not be considered as a preferred systemic treatment in patients with microsatellite stable disease outside of clinical trials. In the coming years, a better understanding of the molecular mechanisms underlying resistance to checkpoint inhibition, and the identification of positive predictive biomarkers will be important for the successful integration of IO into treatment concepts for BTC patients.

Carboxyl-terminal polypeptide fragment of MUC16 combing stathmin1 promotes gallbladder cancer cell migration and invasion

CA-125, coded by MUC16 gene, is responsible to many kinds of tumor metastasis. However, the related mechanism remains unclear. We have established a novel manner to reveal gallbladder cancer metastasis related to serum CA-125 levels through the C-terminal polypeptide of MUC16 gene production. MUC16 C-terminal polypeptide significantly promoted gallbladder cancer cell migration and invasion in vitro. Mass spectrum indicated that interaction of MUC16 C-terminal fragment with the C-terminal domain of stathmin1 inhibited the phosphorylation of stathmin1 to promote the combination with tubulin. Stathmin1 knockdown inhibited the migration and invasion of gallbladder cancer cells in vitro and lung metastasis in vivo induced by MUC16 C-terminal polypeptide. The high expression level of MUC16c consistent with stathmin1 was also confirmed in gallbladder cancer tissues. Our study revealed the underlying mechanism of gallbladder cancer metastasis related to CA-125 levels, which was beneficial for CA-125 in gallbladder cancer diagnose and therapy.

Combining Immunoscore with Clinicopathologic Features in Cholangiocarcinoma: An Influential Prognostic Nomogram

PURPOSE

The aim of this study was to determine the Immunoscore as an independent prognostic factor for cholangiocarcinoma and establish a useful prognostic model for postoperative patients.

METHODS

This retrospective study was performed to assess the correlation between the clinicopathological features, tumor immune microenvironment, and prognosis of 76 patients with cholangiocarcinoma. Multivariate analysis was used to identify independent factors significantly associated with local recurrence-free survival (LRFS) and overall survival (OS). Finally, we constructed a nomogram combining the Immunoscore with clinicopathologic features to predict postoperative recurrence and OS.

RESULTS

The present study showed that immune cell infiltration was negatively correlated with tumor size, peripheral vascular invasion, lymph node metastasis, and tumor staging. Kaplan-Meier curves indicated that a decreased Immunoscore was associated with poor prognosis. Multivariate analysis demonstrated that resection type, number of tumors, lymph node metastasis, TNM staging, and the Immunoscore were significantly associated with LRFS. For OS, the significantly correlated factors included resection type, peripheral vascular invasion, TNM staging, and the Immunoscore. Immunoscore was superior to TNM staging in predicting both LRFS and OS according to the receiver operating characteristic analysis. Based on the results of the Cox regression analysis, a prognostic nomogram for the postoperative recurrence of cholangiocarcinoma and OS of patients was established.

CONCLUSION

The results of this study suggest that the Immunoscore may be used as an independent predictor of postoperative recurrence and OS of patients with cholangiocarcinoma. The Immunoscore appears to offer distinct advantages over the TNM staging system. By combining the Immunoscore and clinicopathological features, the proposed nomogram provides a more accurate predictive tool for postoperative patients with cholangiocarcinoma.

New insights into ErbB3 function and therapeutic targeting in cancer

INTRODUCTION

The importance of ErbB3 receptor tyrosine kinase in cancer progression, primary and acquired drug resistance, has become steadily evident since its discovery in 1989. ErbB3 overexpression in various solid organ malignancies is associated with shorter survival of patients. However, initial strategies to therapeutically target ErbB3 have not been rewarding.

AREAS COVERED

Here, we provide an overview of ErbB3 biology in carcinogenesis. We outline the role of ErbB3 as a critical pathway for resistance to other anti-cancer drugs. We focus on emerging clinical data, which will steer the potential future development of ErbB3 directed therapies.

EXPERT OPINION

Initial approaches to ErbB3 targeting have been challenging. However, the lack of success of anti-ErbB3 therapies in ongoing clinical trials may relate more to the complex biology of the receptor and challenges with the biomarkers used to date. Furthermore, it seems certain that the expression of the receptor per se is necessary but not sufficient for the response to ErbB3 therapies. Emerging data suggest that more sophisticated biomarkers are needed. Nonetheless, it is also likely that ErbB3 therapies may have the most efficacy in combination therapy, and their favorable toxicity profile makes this feasible.

Overview of current targeted therapy in gallbladder cancer

Gallbladder cancer (GBC) is rare, but is the most malignant type of biliary tract tumor. Unfortunately, only a small population of cancer patients is acceptable for the surgical resection, the current effective regimen; thus, the high mortality rate has been static for decades. To substantially circumvent the stagnant scenario, a number of therapeutic approaches owing to the creation of advanced technologic measures (e.g., next-generation sequencing, transcriptomics, proteomics) have been intensively innovated, which include targeted therapy, immunotherapy, and nanoparticle-based delivery systems. In the current review, we primarily focus on the targeted therapy capable of specifically inhibiting individual key molecules that govern aberrant signaling cascades in GBC. Global clinical trials of targeted therapy in GBC are updated and may offer great value for novel pathologic and therapeutic insights of this deadly disease, ultimately improving the efficacy of treatment.

Topoisomerase II alpha promotes gallbladder cancer proliferation and metastasis through activating phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway

BACKGROUND

Topoisomerase II alpha (TOP2A) has been reported to play a crucial role in the tumorigenesis of various cancer types. However, the biological role of TOP2A in gallbladder cancer (GBC) remains unknown. The current study aimed to explore the function and potential mechanism of TOP2A in GBC.

METHODS

Based on Gene Expression Profiling Interactive Analysis data, we found TOP2A was significantly up-regulated in GBC tissues and resulting in shorter overall survival. Quantitative real-time polymerase chain reaction and immunohistochemistry were conducted to detect the expression of TOP2A in 45 pairs of GBC tissues and adjacent non-tumor tissues. In vitro, cell proliferation, migration, and invasion ability were examined by cell counting kit-8 and transwell assay, respectively. Epithelial-mesenchymal transition (EMT) related and phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway-related markers were measured by Western blotting. Xenograft model assay was performed to evaluate the effect of TOP2A in vivo.

RESULTS

TOP2A was found up-regulated in GBC (tumor vs. normal, 12.62 vs. 0.34) and correlated with the late tumor node metastasis stage (P = 0.0032), present of lymph node metastasis (P = 0.0273), and poor prognosis in GBC patients (log-rank P = 0.028). In vitro and in vivo assays showed that knockdown of TOP2A notably inhibited cell proliferation, migration, invasion, EMT process, and tumor growth in GBC. In addition, TOP2A down-regulation significantly decreased the protein levels of phosphor (p)-PI3K, p-Akt, and p-mTOR.

CONCLUSION

Our study demonstrates that TOP2A was overexpressed in GBC and associated with poor prognosis in GBC patients. TOP2A promotes GBC cell proliferation, migration, invasion, EMT process, and tumor growth through activating PI3K/Akt/mTOR signaling pathway, and may serve as a novel prognostic biomarker and therapeutic target for GBC.

MUC16 C-terminal binding with ALDOC disrupts the ability of ALDOC to sense glucose and promotes gallbladder carcinoma growth

The MUC16 C-terminal (MUC16c) level is associated with tumor serum CA-125 levels, however, the roles remain unclear in gallbladder carcinoma (GBC). In this study, we found that MUC16c promoted glucose uptake and glycolysis for GBC cell proliferation. Mass spectrometry analysis suggested that MUC16c could combine with aldolase. The ALDOC mRNA and protein are overexpressed in GBC tumors. The IHC results also showed the consistent up-regulation of. ALDOC and MUC16c level in GBC tumor tissues than in peritumor tissues. We determined that MUC16c combining with ALDOC promoted ALDOC protein stability and disrupted the ability of ALDOC sensing glucose deficiency, which activated AMPK pathway and increased GBC cell proliferation. ALDOC knockdown significantly inhibited the glucose uptake and glycolysis induced by MUC16c. Our study established important roles of MUC16c promoting GBC cell glycolysis and proliferation and revealed the underlying mechanism of CA-125-related heavy tumor metabolic burden in GBC.

Integrated genomic analysis reveals mutated ELF3 as a potential gallbladder cancer vaccine candidate

Gallbladder cancer (GBC) is an aggressive gastrointestinal malignancy with no approved targeted therapy. Here, we analyze exomes (n = 160), transcriptomes (n = 115), and low pass whole genomes (n = 146) from 167 gallbladder cancers (GBCs) from patients in Korea, India and Chile. In addition, we also sequence samples from 39 GBC high-risk patients and detect evidence of early cancer-related genomic lesions. Among the several significantly mutated genes not previously linked to GBC are ETS domain genes ELF3 and EHF, CTNNB1, APC, NSD1, KAT8, STK11 and NFE2L2. A majority of ELF3 alterations are frame-shift mutations that result in several cancer-specific neoantigens that activate T-cells indicating that they are cancer vaccine candidates. In addition, we identify recurrent alterations in KEAP1/NFE2L2 and WNT pathway in GBC. Taken together, these define multiple targetable therapeutic interventions opportunities for GBC treatment and management.

High Systemic Inflammation Response Index (SIRI) Indicates Poor Outcome in Gallbladder Cancer Patients with Surgical Resection: A Single Institution Experience in China

PURPOSE

The systemic inflammation response index (SIRI) has been reported to have prognostic ability in various solid tumors but has not been studied in gallbladder cancer (GBC). We aimed to determine its prognostic value in GBC.

Materials and Methods

From 2003 to 2017, patients with confirmed GBC were recruited. To determine the SIRI's optimal cutoff value, a time-dependent receiver operating characteristic curve was applied. Univariate and multivariate Cox analyses were performed for the recognition of significant factors. Then the cohort was randomly divided into the training and the validation set. A nomogram was constructed using the SIRI and other selected indicators in the training set, and compared with the TNM staging system. C-index, calibration plots, and decision curve analysis were performed to assess the nomogram's clinical utility.

RESULTS

One hundred twenty-four patients were included. The SIRI's optimal cutoff value divided patients into high (≥ 0.89) and low SIRI (< 0.89) groups. Kaplan-Meier curves according to SIRI levels were significantly different (p < 0.001). The high SIRI group tended to stay longer in hospital and lost more blood during surgery. SIRI, body mass index, weight loss, carbohydrate antigen 19-9, radical surgery, and TNM stage were combined to generate a nomogram (C-index, 0.821 in the training cohort, 0.828 in the validation cohort) that was significantly superior to the TNM staging system both in the training (C-index, 0.655) and validation cohort (C-index, 0.649).

CONCLUSION

The SIRI is an independent predictor of prognosis in GBC. A nomogram based on the SIRI may help physicians to precisely stratify patients and implement individualized treatment.

TBL1XR1 induces cell proliferation and inhibit cell apoptosis by the PI3K/AKT pathway in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest solid tumors. Identification of diagnostic and therapeutic biomarkers for PDAC is urgently needed. Transducin (β)-like 1 X-linked receptor 1 (TBL1XR1) has been linked to the progression of various human cancers. Nevertheless, the function and role of TBL1XR1 in pancreatic cancers are unclear.

AIM

To elucidate the function and potential mechanism of TBL1XR1 in the development of PDAC.

METHODS

Ninety patients with histologically-confirmed PDAC were included in this study. PDAC tumor samples and cell lines were used to determine the expression of TBL1XR1. CCK-8 assays and colony formation assays were carried out to assess PDAC cell viability. Flow cytometry was performed to measure the changes in the cell cycle and cell apoptosis. Changes in related protein expression were measured by western blot analysis. Animal analysis was conducted to confirm the impact of TBL1XR1 in vivo.

RESULTS

Patients with TBL1XR1-positive tumors had worse overall survival than those with TBL1XR1-negative tumors. Moreover, we found that TBL1XR1 strongly promoted PDAC cell proliferation and inhibited PDAC cell apoptosis. Moreover, knockdown of TBL1XR1 induced G0/G1 phase arrest. In vivo animal studies confirmed that TBL1XR1 accelerated tumor cell growth. The results of western blot analysis showed that TBL1XR1 might play a key role in regulating PDAC cell proliferation and apoptosis via the PI3K/AKT pathway.

CONCLUSION

TBL1XR1 promoted PDAC cell progression and might be an effective diagnostic and therapeutic marker for pancreatic cancer.

A metagenomic study of biliary microbiome change along the cholecystitis-carcinoma sequence

Background

Gallbladder cancer (GBC) is the most common cancer type of the biliary tract, and an association has been found between chronic calculous cholecystitis (CCC) and an increased incidence of GBC mortality. An understanding of the relationship between CCC and its carcinogenesis may enable us to prevent and cure GBC. In this study, we attempted to explore changes in the microbiome profile that take place during the transition from chronic cholecystitis mucosa to malignant lesions.

Results

Seven paired human GBC and CCC samples were provided by patients who had undergone laparoscopic cholecystectomy or radical cholecystectomy. Mucosal DNA extraction and metagenomic sequencing were performed to evaluate changes in the microbiota between the two groups. We found that GBC patients and CCC patients shared similar stable and permanent dominant species and showed apparent differences in their biliary microbial composition and gene function. Peptostreptococcus stomatis and Enterococcus faecium may potentially play a role in GBC progression. In addition, the metagenomic species profiles, co‐abundance and co‐exclusion correlations, and CAZyme prevalence showed significant differences between the CCC and GBC groups.

Conclusion

Our data suggested that changes in the microbiota between CCC and GBC may help deepen our understanding of the complex spectrum of different microbiotas involved in the development of GBC. Although the cohort size was small, this study has presented the first evidence of the existence of an altered biliary microbiota in GBC, which is clearly different from that in CCC patients.

Role of PI3K/AKT pathway in cancer: the framework of malignant behavior

Given that the PI3K/AKT pathway has manifested its compelling influence on multiple cellular process, we further review the roles of hyperactivation of PI3K/AKT pathway in various human cancers. We state the abnormalities of PI3K/AKT pathway in different cancers, which are closely related with tumorigenesis, proliferation, growth, apoptosis, invasion, metastasis, epithelial-mesenchymal transition, stem-like phenotype, immune microenvironment and drug resistance of cancer cells. In addition, we investigated the current clinical trials of inhibitors against PI3K/AKT pathway in cancers and found that the clinical efficacy of these inhibitors as monotherapy has so far been limited despite of the promising preclinical activity, which means combinations of targeted therapy may achieve better efficacies in cancers. In short, we hope to feature PI3K/AKT pathway in cancers to the clinic and bring the new promising to patients for targeted therapies.

Genomic Landscape and Targeted Treatment of Gallbladder Cancer: Results of a First Ongoing Prospective Study

Background  Prognosis of gallbladder cancer (GBC) has not changed in the past 20 years. Comprehensive genomic profiling (CGP) carries potential to determine the actionability for multiple targets, including ERBB2 , ERBB3 , MET , ROSI , FGFR , and PIK3 . This study evaluates the role of CGP and targeted therapies. Methods  This is a multicenter, prospective, single-arm study. All consecutive patients of unresectable and/or metastatic GBC of age ≥18 years were enrolled. Hybrid capture-based CGP was performed by Foundation Medicine CDx. All patients received first-line chemotherapy with gemcitabine-cisplatin regimen. Patients with ERBB2/3 amplification received trastuzumab with capecitabine or nab-paclitaxel, and patients with MET amplification were treated with crizotinib. For ERBB2/3 mutations, lapatinib plus capecitabine regimen was used. Results  Fifty patients were studied with a median age of 56 years (range 26-83) and a male-to-female ratio of 1:1.6. ERBB2 and ERBB3 amplification was seen in 9 (18%) and 2 (4%) patients, respectively. Four patients with ERBB2 amplification received trastuzumab and/or lapatinib, showed partial response, and maintained response beyond 12 weeks. One patient had mixed response, whereas two patients progressed on trastuzumab and lapatinib. Three patients with ERBB3 mutations showed response to lapatinib-capecitabine. One patient with MET amplification responded to crizotinib for 4 weeks. PIK3 mutations were present in 14% of cases and were independent of ERBB aberrations. Conclusion  GBC is enriched in 28% of patients with ERBB2 and ERBB3 amplifications and/or mutations. Responses are seen with lapatinib in concurrent ERBB2 mutation and amplification. ERBB3 mutation showed response to lapatinib. MET and PIK3 are new findings in GBC, which may be targeted.

Prognostic Significance of the Preoperative Lymphocyte to Monocyte Ratio in Patients with Gallbladder Carcinoma

Background

This study was designed to investigate the prognostic value of the lymphocyte to monocyte ratio (LMR) in patients with gallbladder carcinoma (GBC).

Patients and Methods

We retrospectively enrolled 154 consecutive GBC patients from 2005 to 2017 in this study. The LMR of preoperative blood samples was calculated by dividing the lymphocyte count by the monocyte count. A receiver operating characteristic (ROC) curve was employed to identify the optimal cut-off value of the LMR in the determination of overall survival (OS). The Kaplan–Meier method was utilized to assess OS, and the Log rank test was employed to compare survival differences. Univariate and multivariate Cox regression analyses were conducted to detect independent prognostic indicators.

Results

The optimal cut-off point for the LMR was 4.76 according to the ROC curve. Patients ≤60 years old with an LMR ≤4.76 experienced significantly worse OS than those with an LMR >4.76 (hazard ratio (HR): 0.399, 95% confidence interval (CI): 0.265–0.602, P<0.001); however, the prognostic value of the LMR was not determined in patients >60 years old or among the entire study cohort (both P>0.05). Significantly poorer OS was observed in patients >60 years with an LMR ≤4.21 compared to those with an LMR >4.21 (HR: 1.830, 95% CI: 1.129–2.967, P=0.014). Multivariate Cox regression analysis indicated that both the high and low LMR cut-off values were independent risk factors for OS (HR: 0.272, 95% CI: 0.105–0.704, P=0.007; HR: 0.544, 95% CI: 0.330–0.895, P=0.017).

Conclusion

The LMR is an independent prognostic indicator for GBC patients, the cut-off value of which is age dependent.

Targeting gallbladder cancer: a pathway based perspective

Gallbladder cancer (GBC) has a poor prognosis with a 5-year survival rate suggesting the need for more effective treatment strategies. Studying the cross-talk of several pathways involved in crucial cellular and biological processes such as cell growth, proliferation, migration and apoptosis would prove beneficial in identifying key players of GBC progression and targeting them. This review highlights several pathways known to be dysregulated in GBC onset and progression and describes known and potential targets. Within these pathways, there are proteins involved in the signalling cascade, which may be targeted as potential biomarkers and drug targets. Furthermore, the cross-talk of these pathways is investigated in the context of GBC and the implications thereof. A better understanding of the pathways involved in GBC pathogenesis will aid clinicians in the prognosis, diagnosis and treatment of patients. There are significant clinical implications of GBC pathway-based studies as they permit the understanding of onset and progression of the disease.

TASP1 Promotes Gallbladder Cancer Cell Proliferation and Metastasis by Up-regulating FAM49B via PI3K/AKT Pathway

The highly conserved protease TASP1 not only takes part in critical site-specific proteolysis, but also plays an important role in numerous liquid and solid malignancies. However, the TASP1 expression and its biological regulation function in malignant gallbladder carcinoma (GBC) remain fully unknown. Here we observed that TASP1 levels were substantially overexpressed in GBC samples compared with non-tumor tissues. High TASP1 level was closely associated with T stage and metastasis, and was also correlated with poor prognosis in GBC patients. The depletion of TASP1 inhibited GBC cell proliferation and metastasis in vitro and in vivo. Furthermore, we first revealed that FAM49B had biological function and was positively regulated by TASP1 activating PI3K/AKT signaling pathway in GBC. At the same time, FAM49B also promoted GBC cell proliferation and migration. Inhibition of PI3K/AKT with LY294002 or FAM49B expression abrogated Myc-TASP1/Lv-shTASP1-induced GBC cell proliferation and motility. In conclusion, these findings demonstrate that TASP1 is critical for GBC progression via TASP1-PI3K/AKT-FAM49B axis and it may be a novel prognostic factor. The therapeutic targeting TASP1 may be a potential treatment approach for GBC patients.

Potent Antitumor Activity of Liposomal Irinotecan in an Organoid- and CRISPR-Cas9-Based Murine Model of Gallbladder Cancer

Gallbladder cancer is associated with a dismal prognosis, and accurate in vivo models will be elemental to improve our understanding of this deadly disease and develop better treatment options. We have generated a transplantation-based murine model for gallbladder cancer that histologically mimics the human disease, including the development of distant metastasis. Murine gallbladder–derived organoids are genetically modified by either retroviral transduction or transfection with CRISPR/Cas9 encoding plasmids, thereby allowing the rapid generation of complex cancer genotypes. We characterize the model in the presence of two of the most frequent oncogenic drivers—Kras and ERBB2—and provide evidence that the tumor histology is highly dependent on the driver oncogene. Further, we demonstrate the utility of the model for the preclinical assessment of novel therapeutic approaches by showing that liposomal Irinotecan (Nal-IRI) is retained in tumor cells and significantly prolongs the survival of gallbladder cancer–bearing mice compared to conventional irinotecan.

Biallelic ERBB3 loss-of-function variants are associated with a novel multisystem syndrome without congenital contracture

Background

Gain-of-function pathogenic variants of the Erb-B2 receptor tyrosine kinase 3 (ERBB3) gene contribute to the occurrence and development of a variety of human carcinomas through activation of phosphatidylinositol 3-kinase (PI3K)/AKT and extracellular signal-regulated kinase (ERK) signaling. ERBB3 gene homozygous germline variants, whose loss of function may cause autosomal recessive congenital contractural syndrome, were recently identified. This study aims to identify the disease-causing gene in a Chinese pedigree with variable phenotypes involving multiple systems, including developmental delay, postnatal growth retardation, transient lower limb asymmetry, facial malformations, atrioventricular canal malformation, bilateral nystagmus and amblyopia, feeding difficulties, immunodeficiency, anemia, and liver damage, but without congenital contracture.

Methods

Trio-whole exome sequencing (WES) was performed to identify the disease-causing gene in a 24-month-old Chinese female patient. The pathogenicity of the identified variants was evaluated using in silico tools and in vitro functional studies.

Results

Trio-WES revealed compound heterozygous variants of c.1253 T > C (p.I418T) and c.3182dupA (p.N1061Kfs*16) in the ERBB3 gene. Functional studies showed that p.I418T resulted in normal expression of ERBB3, which was capable of interacting with ERBB2. However, the variant impaired ERBB3 phosphorylation, consequently blocking ERBB2 phosphorylation and AKT and ERK activation. The truncated protein resulting from the c.3182dupA variant also lacked the capacity to activate downstream signaling pathways.

Conclusions

We report the first patient with a novel multisystem syndrome disorder without congenital contracture resulting from biallelic loss-of-function variants of ERBB3.

NOP2/Sun RNA methyltransferase 2 promotes tumor progression via its interacting partner RPL6 in gallbladder carcinoma

NOP2/Sun domain family, member 2 (NSUN2) is a nuclear RNA methyl-transferase catalyzing 5-methylcytosine formation. Evidence shows that NSUN2 is correlated with cell unlimited proliferation. However, its functional role in gallbladder carcinoma (GBC), which is the most common biliary tract malignancy and has a poor prognosis, remains to be determined. Here we found that NSUN2 was highly expressed in GBC tissues as well as cell lines. NSUN2 silencing repressed GBC cell proliferation and tumorigenesis both in vitro and in vivo. Conversely, upregulation of NSUN2 enhanced GBC cell growth and colony formation. We further discovered that RPL6 was a closely interacting partner with NSUN2. Silencing RPL6 resulted in insufficient NSUN2 translational level and accumulative NSUN2 transcriptional level. Exogenous expression of NSUN2 partially rescued the effect of RPL6 in gallbladder cancer progression. Taken together, our data provided novel mechanic insights into the function of NSUN2 in GBC, thus pointing to NSUN2 as a potential and effective therapeutic approach to GBC treatment.

The Role of the Lymphocyte Functional Crosstalk and Regulation in the Context of Checkpoint Inhibitor Treatment-Review

During the last decade, the dynamics of the cellular crosstalk have highlighted the significance of the host vs. tumor interaction. This resulted in the development of novel immunotherapeutic strategies in order to modulate/inhibit the mechanisms leading to escape of tumor cells from immune surveillance. Different monoclonal antibodies directed against immune checkpoints, e.g., the T lymphocyte antigen 4 and the programmed cell death protein 1/ programmed cell death ligand 1 have been successfully implemented for the treatment of cancer. Despite their broad activity in many solid and hematologic tumor types, only 20–40% of patients demonstrated a durable treatment response. This might be due to an impaired T cell tumor interaction mediated by immune escape mechanisms of tumor and immune cells as well as alterations in the composition of the tumor microenvironment, peripheral blood, and microbiome. These different factors dynamically regulate different steps of the cancer immune process thereby negatively interfering with the T cell –mediated anti-tumoral immune responses. Therefore, this review will summarize the current knowledge of the different players involved in inhibiting tumor immunogenicity and mounting resistance to checkpoint inhibitors with focus on the role of tumor T cell interaction. A better insight of this process might lead to the development of strategies to revert these inhibitory processes and represent the rational for the design of novel immunotherapies and combinations in order to improve their efficacy.

Precision oncology for gallbladder cancer: insights from genetic alterations and clinical practice

Background

Gallbladder cancer (GBC) is an uncommon but highly fatal malignancy, with limited adjuvant therapy. The present study aims to explore the actionable alterations and precision oncology for GBC patients.

Methods

Patients with pathologically confirmed GBC who progressed after first-line systemic treatment were enrolled. Genomic alterations were captured by ultra-deep targeted next-generation sequencing (tNGS). The actionabilities of alterations and the therapeutic regimens were evaluated by a multidisciplinary tumor board (MDTB).

Results

Sixty patients with GBC were enrolled and analyzed. tNGS was successfully achieved in all patients. The median tumor mutation burden for GBC patients was 5.4 (range: 0.8-36.74) mutations/Mb, and the most common mutations were in TP53 (73%), CDKN2A (25%) and PIK3CA (20%). The most frequently copy-number altered genes were CDKN2A deletion (11.7%) and ERBB2 amplification (13.3%). 23% of the patients displayed gene fusion; 17 fusion events were identified, and 14 of the 17 fusion events co-occurred with mutations in driver genes. In total, 46 of the 60 (76%) patients were identified as possessing at least one actionable target to proceed precision oncology.

Conclusions

The present study revealed the mutational profile for the clinical practice of precision oncology in GBC patients.

ERBB2 and KRAS alterations mediate response to EGFR inhibitors in early stage gallbladder cancer

The uncommonness of gallbladder cancer in the developed world has contributed to the generally poor understanding of the disease. Our integrated analysis of whole exome sequencing, copy number alterations, immunohistochemical, and phospho-proteome array profiling indicates ERBB2 alterations in 40% early-stage rare gallbladder tumors, among an ethnically distinct population not studied before, that occurs through overexpression in 24% (n = 25) and recurrent mutations in 14% tumors (n = 44); along with co-occurring KRAS mutation in 7% tumors (n = 44). We demonstrate that ERBB2 heterodimerizes with EGFR to constitutively activate the ErbB signaling pathway in gallbladder cells. Consistent with this, treatment with ERBB2-specific, EGFR-specific shRNA or with a covalent EGFR family inhibitor Afatinib inhibits tumor-associated characteristics of the gallbladder cancer cells. Furthermore, we observe an in vivo reduction in tumor size of gallbladder xenografts in response to Afatinib is paralleled by a reduction in the amounts of phospho-ERK, in tumors harboring KRAS (G13D) mutation but not in KRAS (G12V) mutation, supporting an essential role of the ErbB pathway. In overall, besides implicating ERBB2 as an important therapeutic target under neo-adjuvant or adjuvant settings, we present the first evidence that the presence of KRAS mutations may preclude gallbladder cancer patients to respond to anti-EGFR treatment, similar to a clinical algorithm commonly practiced to opt for anti-EGFR treatment in colorectal cancer.

SLC25A22 promotes proliferation and metastasis by activating MAPK/ERK pathway in gallbladder cancer

Background

SLC25A22, a member of mitochondrial carrier system (MCS) family encoding a mitochondrial glutamate transporter, has been reported to have vital roles in promoting proliferation and migration in cancer. Gallbladder cancer (GBC) is the most common biliary tract malignancy and has a poor prognosis. We aimed to determine the expression and function of SLC25A22 in GBC.

Methods

Immunohistochemistry (IHC) staining analysis and quantitative real-time PCR (qRT-PCR) were conducted to determine the expression of SLC25A22 in GBC tissues. Human NOZ and GBC-SD cells were used to perform the experiments. The protein expression was detected by western-blot analysis. Cell viability was evaluated via CCK-8 assay and colony formation assay. Cell migration and invasion in vitro were investigated by wound healing and transwell assay. Annexin V/PI staining assay for apoptosis were measured by flow cytometry. The effect of SLC25A22 in vivo was conducted with subcutaneous xenograft.

Results

We indicated that the expression of SLC25A22 was significantly upregulated in GBC tumor tissues as well as cell lines. Downregulation of SLC25A22 inhibited GBC cell growth and proliferation in vitro and in vivo and also had an effect on metastasis of GBC cells through the EMT processes. In addition, inhibition of SLC25A22 promoted mitochondrial apoptosis via downregulating BCL-2 and upregulating cleaved PARP, Cytochrome-c, and BAX mediated by MAPK/ERK pathway.

Conclusions

Our study identified that SLC25A22 promoted development of GBC activating MAPK/ERK pathway. SLC25A22 has a potential to be used as a target for cancer diagnosis of GBC and related therapies.