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

Identification of genes associated with gall bladder cell carcinogenesis: Implications in targeted therapy of gall bladder cancer

Gall bladder cancer (GBC) is becoming a very devastating form of hepatobiliary cancer in India. Every year new cases of GBC are quite high in India. Despite recent advanced multimodality treatment options, the survival of GBC patients is very low. If the disease is diagnosed at the advanced stage (with local nodal metastasis or distant metastasis) or surgical resection is inoperable, the prognosis of those patients is very poor. So, perspectives of targeted therapy are being taken. Targeted therapy includes hormone therapy, proteasome inhibitors, signal transduction and apoptosis inhibitors, angiogenesis inhibitors, and immunotherapeutic agents. One such signal transduction inhibitor is the specific short interfering RNA (siRNA) or short hairpin RNA (shRNA). For developing siRNA-mediated therapy shRNA, although several preclinical studies to evaluate the efficacy of these key molecules have been performed using gall bladder cells, many more clinical trials are required. To date, many such genes have been identified. This review will discuss the recently identified genes associated with GBC and those that have implications in its treatment by siRNA or shRNA.

Next generation sequencing uncovers multiple miRNAs associated molecular targets in gallbladder cancer patients

Gallbladder cancer (GBC) is a lethal disease with surgical resection as the only curative treatment. However, many patients are ineligible for surgery, and current adjuvant treatments exhibit limited effectiveness. Next-generation sequencing has improved our understanding of molecular pathways in cancer, sparking interest in microRNA-based gene regulation. The aim of the study is to identify dysregulated miRNAs in GBC and investigate their potential as therapeutic tools for effective and targeted treatment strategies. GBC and control tissue samples were sequenced for miRNA expression using the Illumina HiSeq platform. Biological processes and related pathways were determined using the Panther and Gene Ontology databases. 439 significantly differentially expressed miRNAs were identified; 19 of them were upregulated and 29 were downregulated. Key enriched biological processes included immune cell apoptosis, endoplasmic reticulum (ER) overload response, and negative regulation of the androgen receptor (AR) signaling pathway. Panther analysis revealed the insulin-like growth factor (IGF)-mitogen activated protein kinases (MAPK) cascade, p38 MAPK pathway, p53 pathway, and FAS (a subgroup of the tumor necrosis factor receptor) signaling pathway as highly enriched among dysregulated miRNAs. Kirsten rat sarcoma virus (KRAS), AR, and interferon gamma (IFN-γ) pathways were identified among the key pathways potentially amenable to targeted therapy. We concluded that a combination approach involving miRNA-based interventions could enhance therapeutic outcomes. Our research emphasizes the importance of precision medicine, targeting pathways using sense and anti-sense miRNAs as potential therapies in GBC.

miR-193a-3p Enhanced the Chemosensitivity to Trametinib in Gallbladder Carcinoma by Targeting KRAS and Downregulating ERK Signaling

Objective: In this study, the authors identified miR-193a-3p as a tumor-suppressing microRNA, and its effects on the chemosensitivity to trametinib in gallbladder carcinoma (GBC) were evaluated. Materials and Methods: The levels of miR-193a-3p in clinical GBC tissues and GBC cells were determined by quantitative real-time polymerase chain reaction. The protein levels of KRAS, ERK, and phosphorylated ERK (p-ERK) were examined by Western blot. Dual-luciferase reporter assays were performed to confirm the interaction between miR-193a-3p and KRAS. The effect of miR-193a-3p knockdown or overexpression on the malignant behaviors and chemosensitivity of GBC was determined by 3-(4,5-dimethlthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide and flow cytometry assays in vitro and further examined in a xenograft model. Results: The levels of miR-193a-3p were significantly decreased in GBC cell lines, especially with KRAS mutations. In addition, miR-193a-3p overexpression retarded cell proliferation of GBC, but induced cell apoptosis. Moreover, miR-193a-3p overexpression significantly improved the chemosensitivity of GBC to trametinib both in in vitro assays and in vivo xenograft mouse model. Further mechanisms disclosed that KRAS was a target of miR-193a-3p and levels of p-ERK were increased by treatment with miR-193a-3p inhibitor in GBC. Conclusions: These data suggested that miR-193a-3p enhanced the chemosensitivity to trametinib in GBC with wild-type KRAS or KRAS mutations by directly targeting KRAS and finally downregulated ERK signaling.

Afatinib in combination with GEMOX chemotherapy as the adjuvant treatment in patients with ErbB pathway mutated, resectable gallbladder cancer: study protocol for a ctDNA-based, multicentre, open-label, randomised, controlled, phase II trial

INTRODUCTION

Gallbladder cancer (GBC) is an aggressive type of digestive system cancer with a dismal outcome. Given the lack of effective treatment options, the disease rapidly reoccurs and 5-year survival rate is <5%. Our team previously found that a significant percentage of GBC tissues harboured mutations of the ErbB-related pathway. Afatinib is a chemically synthesised drug specifically targeting the ErbB pathway mutations. However, its efficacy in the treatment of patients with GBC remains unknown. Circulating tumour DNA (ctDNA) refers to a proportion of cell-free DNA in the blood which is released by apoptotic and necrotic cells from tumours in situ, metastatic foci or circulating tumour cells. ctDNA-based liquid biopsy is a non-invasive pathological detection method that offers additional value to evaluate the therapeutic efficacy of antitumour drugs.

METHODS AND ANALYSIS

We conduct a multicentre and randomised study on afatinib combined with gemcitabine and oxaliplatin (GEMOX) in patients with ErbB pathway mutated GBC. Clinical and biological evaluation involving ErbB pathway ctDNA detection will be made during the 3-year follow-up after participation. The primary objective of this clinical trial is to evaluate the clinical efficacy of afatinib. Disease-free survival is the primary end point and will be correlated with plasma ctDNA of patients in the treatment with afatinib. In addition, we will evaluate the sensitivity and specificity of plasma ctDNA for monitoring tumour recurrence and progression. Finally, we will assess the safety of afatinib by keeping an eye on the safety indicators.

ETHICS AND DISSEMINATION

The study was approved by the medical-ethical review committee of Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine and Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. The clinical trials results, even inconclusive, will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04183712.

Application value of whole exome sequencing in screening and identifying novel mutations of hypopharyngeal cancer

The research on targeted therapy of hypopharyngeal cancer is very scarce. The discovery of new targeted driver genes will promote the progress of hypopharyngeal cancer therapy to a great extent. In our research, whole-exome sequencing in 10 patients with hypopharyngeal cancer was performed to identify single nucleotide variations (SNVs) and insertions and deletions (INDELs). American College of Medical Genetics and Genomics (ACMG) guidelines were used to evaluate the pathogenicity of the selected variants. 8113 mutation sites in 5326 genes were identified after strict screening. We identified 72 pathogenic mutations in 53 genes according to the ACMG guidelines. Gene Ontology (GO) annotation and KEGG enrichment analysis show the effect of these genes on cancer. Protein-protein interaction (PPI) was analyzed by string online software. The validation results of the ualcan database showed that 22 of the 53 genes may be related to the poor prognosis of patients with hypopharyngeal cancer. RBM20 has the most significant correlation with hypopharyngeal cancer, and it is likely to be the driver gene of hypopharyngeal cancer. In conclusion, we found possible therapeutic targets for hypopharyngeal cancer, especially RBM20 and KMT2C. Our study provides a basis for the pathogenesis and targeted therapy of hypopharyngeal cancer.

Establishment and characterization of an immortalized epithelial cell line from human gallbladder

Background

Although a plethora of studies have employed multiple gallbladder cancer (GBC) cell lines, it is surprisingly noted that there is still lack of a normal gallbladder epithelial cell line as a normal counterpart, thus impeding substantially the progress of mechanistic studies on the transformation of normal epithelial cells to cancer. Here, we created a normal gallbladder epithelial cell line named L-2F7 from human gallbladder tissue.

Methods

Gallbladder tissues from a diagnosed cholecystitis female patient were collected, and epithelial cells were enriched by magnetic cell sorting. Then, the cells were immortalized by co-introduction of human telomerase reverse transcriptase (hTERT) and Simian virus 40 large T antigen (LT-SV40) via a lentivirus infection system. After clonal selection and isolation, L-2F7 cells were tested for epithelial markers CK7, CK19, CK20, and CD326, genomic feature, cell proliferation, and migration using Western blot, immunofluorescence, whole genome sequencing, karyotyping, and RNA sequencing. L-2F7 cells were also transplanted to Nude (nu/nu) mice to determine tumorigenicity.

Results

We successfully identified one single-cell clone named L-2F7 which highly expressed epithelial markers CD326, CK7, CK19, and CK20. This cell line proliferated with a doubling time of 23 h and the epithelial morphology sustained over 30 passages following immortalization. Transient gene transduction of L-2F7 cells led to expression of exogenous GFP and FLAG protein. L-2F7 cells exhibited both distinct non-synonymous mutations from those of gallbladder cancer tissues and differential non-cancerous gene expression patterns similar to normal tissue. Although they displayed unexpected mobility, L-2F7 cells still lacked the ability to develop tumors.

Conclusion

We developed a non-cancerous gallbladder epithelial cell line, offering a valuable system for the study of gallbladder cancer and other gallbladder-related disorders.

Gallbladder cancer

Gallbladder cancer (GBC) is the most common cancer of the biliary tract, characterized by a very poor prognosis when diagnosed at advanced stages owing to its aggressive behaviour and limited therapeutic options. Early detection at a curable stage remains challenging because patients rarely exhibit symptoms; indeed, most GBCs are discovered incidentally following cholecystectomy for symptomatic gallbladder stones. Long-standing chronic inflammation is an important driver of GBC, regardless of the lithiasic or non-lithiasic origin. Advances in omics technologies have provided a deeper understanding of GBC pathogenesis, uncovering mechanisms associated with inflammation-driven tumour initiation and progression. Surgical resection is the only treatment with curative intent for GBC but very few cases are suitable for resection and most adjuvant therapy has a very low response rate. Several unmet clinical needs require to be addressed to improve GBC management, including discovery and validation of reliable biomarkers for screening, therapy selection and prognosis. Standardization of preneoplastic and neoplastic lesion nomenclature, as well as surgical specimen processing and sampling, now provides reproducible and comparable research data that provide a basis for identifying and implementing early detection strategies and improving drug discovery. Advances in the understanding of next-generation sequencing, multidisciplinary care for GBC, neoadjuvant and adjuvant strategies, and novel systemic therapies including chemotherapy and immunotherapies are gradually changing the treatment paradigm and prognosis of this recalcitrant cancer.

Impact of Molecular Tumor Board on the Clinical Management of Patients With Cancer

PURPOSE

Multidisciplinary molecular tumor boards (MTBs) help in interpreting complex genomic data generated by molecular tumor profiling and improve patients' access to targeted therapies. The purpose of this study was to assess the impact of our institution's MTB on the clinical management of patients with cancer.

METHODS

This study was conducted at a tertiary cancer center in India. Cases to be discussed in the MTB were identified by molecular pathologists, scientists, or oncologists. On the basis of the clinical data and molecular test reports, a course of clinical management was recommended and made available to the treating oncologist. We determined the proportion of patients who were recommended a change in the clinical management. We also assessed compliance of the treating oncologists with MTB recommendations.

RESULTS

There were 339 discussions for 328 unique patients. The median age of the cohort was 54 years (range 17-87), and the majority of the patients were men (65.1%). Of 339 cases, 133 (39.2%) were recommended continuation of ongoing therapy while the remaining 206 (60.7%) were recommended a change in clinical management. Compliance with MTB recommendations for a change in clinical management was 58.5% (79 of 138 evaluable cases). Compliance and implementation for MTB's recommendation to start a new therapy in 104 evaluable cases were 60.5% and 44.2%, respectively. A total of 248 biopsies had at least one actionable mutation. A total of 646 mutations were identified in the cohort, with EGFR being the most frequently altered gene.

CONCLUSION

MTBs help in interpreting results of molecular tests, understanding the significance of molecular abnormalities, and assessing the benefits of available targeted therapies and clinical trials in the management of patients with targetable genetic alterations.

Fusobacterium nucleatum is associated with inflammation and poor survival in early-stage HPV-negative tongue cancer

Persistent pathogen infection is a known cause of malignancy, although with sparse systematic evaluation across tumor types. We present a comprehensive landscape of 1060 infectious pathogens across 239 whole exomes and 1168 transcriptomes of breast, lung, gallbladder, cervical, colorectal, and head and neck tumors. We identify known cancer-associated pathogens consistent with the literature. In addition, we identify a significant prevalence of Fusobacterium in head and neck tumors, comparable to colorectal tumors. The Fusobacterium-high subgroup of head and neck tumors occurs mutually exclusive to human papillomavirus, and is characterized by overexpression of miRNAs associated with inflammation, elevated innate immune cell fraction and nodal metastases. We validate the association of Fusobacterium with the inflammatory markers IL1B, IL6 and IL8, miRNAs hsa-mir-451a, hsa-mir-675 and hsa-mir-486-1, and MMP10 in the tongue tumor samples. A higher burden of Fusobacterium is also associated with poor survival, nodal metastases and extracapsular spread in tongue tumors defining a distinct subgroup of head and neck cancer.

Gallbladder Cancer: Current Insights in Genetic Alterations and Their Possible Therapeutic Implications

Simple Summary

Knowledge of genetic alterations in gallbladder cancer (GBC) continues to increase. This systematic review provides an overview of frequently occurring genetic alterations in GBC and describes their possible therapeutic implications. We detected three frequently (>5%) altered genes (ATM, ERBB2 and PIK3CA) for which targeted therapies are available in other cancer types. For solid cancers with microsatellite instability or a high tumor mutational burden pembrolizumab is FDA-approved. Altogether, these five biomarkers might be used in future molecular panels to enable precision medicine for patients with GBC. We found only nine clinical trials evaluating targeted therapies in GBC directed at frequently altered genes (ERBB2, ARID1A, ATM and KRAS). This underlines the challenges to perform such clinical trials in this rare, heterogeneous cancer type and emphasizes the need for multicenter clinical trials.

Abstract

Due to the fast progression in molecular technologies such as next-generation sequencing, knowledge of genetic alterations in gallbladder cancer (GBC) increases. This systematic review provides an overview of frequently occurring genetic alterations occurring in GBC and their possible therapeutic implications. A literature search was performed utilizing PubMed, EMBASE, Cochrane Library, and Web of Science. Only studies reporting genetic alterations in human GBC were included. In total, data were extracted from 62 articles, describing a total of 3893 GBC samples. Frequently detected genetic alterations (>5% in >5 samples across all studies) in GBC for which targeted therapies are available in other cancer types included mutations in ATM, ERBB2, and PIK3CA, and ERBB2 amplifications. High tumor mutational burden (TMB-H) and microsatellite instability (MSI-H) were infrequently observed in GBC (1.7% and 3.5%, respectively). For solid cancers with TMB-H or MSI-H pembrolizumab is FDA-approved and shows an objective response rates of 50% for TMB-H GBC and 41% for MSI-H biliary tract cancer. Only nine clinical trials evaluated targeted therapies in GBC directed at frequently altered genes (ERBB2, ARID1A, ATM, and KRAS). This underlines the challenges to perform such clinical trials in this rare, heterogeneous cancer type and emphasizes the need for multicenter clinical trials.

Molecular characterization of lung squamous cell carcinoma tumors reveals therapeutically relevant alterations

INTRODUCTION

Unlike lung adenocarcinoma patients, there is no FDA-approved targeted-therapy likely to benefit lung squamous cell carcinoma patients.

MATERIALS AND METHODS

We performed survival analyses of lung squamous cell carcinoma patients harboring therapeutically relevant alterations identified by whole exome sequencing and mass spectrometry-based validation across 430 lung squamous tumors.

RESULTS

We report a mean of 11.6 mutations/Mb with a characteristic smoking signature along with mutations in TP53 (65%), CDKN2A (20%), NFE2L2 (20%), FAT1 (15%), KMT2C (15%), LRP1B (15%), FGFR1 (14%), PTEN (10%) and PREX2 (5%) among lung squamous cell carcinoma patients of Indian descent. In addition, therapeutically relevant EGFR mutations occur in 5.8% patients, significantly higher than as reported among Caucasians. In overall, our data suggests 13.5% lung squamous patients harboring druggable mutations have lower median overall survival, and 19% patients with a mutation in at least one gene, known to be associated with cancer, result in significantly shorter median overall survival compared to those without mutations.

CONCLUSIONS

We present the first comprehensive landscape of genetic alterations underlying Indian lung squamous cell carcinoma patients and identify EGFR, PIK3CA, KRAS and FGFR1 as potentially important therapeutic and prognostic target.

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.

Raman spectroscopy-based detection of RNA viruses in saliva: A preliminary report

Several non-invasive Raman spectroscopy-based assays have been reported for rapid and sensitive detection of pathogens. We developed a novel statistical model for the detection of RNA viruses in saliva, based on an unbiased selection of a set of 65 Raman spectral features that mostly attribute to the RNA moieties, with a prediction accuracy of 91.6% (92.5% sensitivity and 88.8% specificity). Furthermore, to minimize variability and automate the downstream analysis of the Raman spectra, we developed a GUI-based analytical tool "RNA Virus Detector (RVD)." This conceptual framework to detect RNA viruses in saliva could form the basis for field application of Raman Spectroscopy in managing viral outbreaks, such as the ongoing COVID-19 pandemic. (http://www.actrec.gov.in/pi-webpages/AmitDutt/RVD/RVD.html).

Genomic Study of Chinese Quadruple-negative GISTs Using Next-generation Sequencing Technology

PURPOSE

Approximately 10% of gastrointestinal stromal tumors (GISTs) are devoid of KIT, PDGFRA (platelet-derived growth factor-alpha), BRAF, and SDH alterations. The aim of this study was to characterize molecular drivers in Chinese patients with quadruple-negative GISTs.

PATIENTS AND METHODS

In 1022 Chinese patients with GIST, mutations of KIT and PDGFRA were analyzed by direct sequencing. Of these mutations, 142 KIT/PDGFRA wild-type (WT) GISTs were detected, and succinate dehydrogenase (SDH) deficiency was determined using immunohistochemistry analysis of succinate dehydrogenase B. In 78 KIT/PDGFRA/SDH cases, we performed targeted 425 cancer-related gene analysis using next-generation sequencing. The correlation between molecular findings and clinicopathologic features was also analyzed.

RESULTS

We defined 72 quadruple-negative GISTs from enrollments. They featured nongastric localization with histologic characteristics of spindle cells and male predilection. An overall 27.78% (20/72) of quadruple-negative tumors carried TP53, and 25.00% (18/72) carried RB1 mutations, which were frequently associated with high mitotic index and large size. TP53 analyses demonstrated coexistence with mutational activation of other oncogenes in 12 of 20 cases. A total of 18 RB1-mutated cases were independent of TP53. Further, no tumors carried NF1 and BRAF mutations.

CONCLUSIONS

We report the genomic analysis of Chinese quadruple-negative patients. These databases may help advance our understanding of quadruple-negative GISTs' progression. Next-generation sequencing from GISTs is feasible to provide relevant data for guiding individualized therapy.

Genomic characteristics and drug screening among organoids derived from non-small cell lung cancer patients

BACKGROUND

Patient-derived organoid (PDO) models are highly valuable and have potentially widespread clinical applications. However, limited information is available regarding organoid models of non-small cell lung cancer (NSCLC). This study aimed to characterize the consistency between primary tumors in NSCLC and PDOs and to explore the applications of PDOs as preclinical models to understand and predict treatment response during lung cancer.

METHODS

Fresh tumor samples were harvested for organoid culture. Primary tumor samples and PDOs were analyzed via whole-exome sequencing. Paired samples were subjected to immunohistochemical analysis. There were 26 antineoplastic drugs tested in the PDOs. Cell viability was assessed using the Cell Titer Glo assay 7-10 days after drug treatment. A heatmap of log-transformed values of the half-maximal inhibitory concentrations was generated on the basis of drug responses of PDOs through nonlinear regression (curve fit). A total of 12 patients (stages I-III) were enrolled, and 7 paired surgical tumors and PDOs were analyzed.

RESULTS

PDOs retained the histological and genetic characteristics of the primary tumors. The concordance between tumors and PDOs in mutations in the top 20 NSCLC-related genes was >80% in five patients. Sample purity was significantly and positively associated with variant allele frequency (Pearson r = 0.82, P = 0.0005) and chromosome stability. The in vitro response to drug screening with PDOs revealed high correlation with the mutation profiles in the primary tumors.

CONCLUSIONS

PDOs are highly credible models for detecting NSCLC and for prospective prediction of the treatment response for personalized precision medicine.

KEY POINTS

Lung cancer organoid models could save precious time of drug testing on patients, and accurately select anticancer drugs according to the drug sensitivity results, so as to provide a powerful supplement and verification for the gene sequencing.

Gallbladder cancer with EGFR mutation and its response to GemOx with erlotinib: a case report and review of literature

Background

Gallbladder cancer (GBC) is the most common and aggressive extra hepatic biliary tree cancer (BTC) with dismal outcome. Complete surgical resection is the treatment of choice. Chemotherapy is used for palliation in advanced GBC where surgery is not possible, and the most commonly used agent is gemcitabine in combination with cisplatin or oxaliplatin or with capecitabine regimens. Complete remissions are hardly encountered in these cases; therefore, it is important to combine standard therapies with molecular targeting.

Case presentation

A 60-year-old woman presented with pain in abdomen and loss of appetite for 1 month, and imaging showed locally advanced gallbladder carcinoma with liver metastasis. After biopsy confirmation, patient was initially started on gemcitabine and oxaliplatin combination followed by gene sequencing, which showed Tp53 (exon 7—c.713 G > A and exon 5—c.376-2A > G) and EGFR (exon 20—T790M) mutation, and erlotinib was added to chemotherapy, after 6 cycles of chemotherapy patient showed a 90% partial radiological response as per RECIST criteria.

Conclusion

This case reports the possible efficacy of erlotinib in combination with gemcitabine and oxaliplatin in treating an EGFR-mutated GBC with liver metastasis. To our knowledge, this is the first article reporting the response to erlotinib combination therapy with this particular solitary mutation.

The Landmark Series: Gallbladder Cancer

Given the rarity of gallbladder carcinoma, level I evidence to guide the multimodal treatment of this disease is lacking. Since 2010, four randomized phase III clinical trials including ABC-02, PRODIGE-12/ACCORD-18, BILCAP, and BCAT, and a single-arm phase II trial (SWOG0809) have been reported on the use of adjuvant strategies for biliary malignancies. These trials have led to the recommendation that patients with resected biliary tract cancer should be offered adjuvant capecitabine chemotherapy and those with R1 margins could be considered for chemoradiotherapy. Because there is no level I evidence to guide neoadjuvant therapy or surgical management, current consensus is based on strong retrospective data. The following review summarizes available trials and highlights the best available evidence that form the basis of consensus statements for the multimodal management of gallbladder carcinoma.

Identification of Altered Genes in Gallbladder Cancer as Potential Driver Mutations for Diagnostic and Prognostic Purposes: A Computational Approach

Prognostic markers for cancer can assist in the evaluation of survival probability of patients and help clinicians to assess the available treatment modalities. Gallbladder cancer (GBC) is a rare tumor that causes 165 087 deaths in the world annually. It is the most common cancer of the biliary tract and has a particularly high incidence in Chile, Japan, and northern India. Currently, there is no accurate diagnosis test or effective molecular markers for GBC identification. Several studies have focused on the discovery of genetic alterations in important genes associated with GBC to propose novel diagnosis pathways and to create prognostic profiles. To achieve this, we performed data-mining of GBC in public repositories, harboring 133 samples of GBC, allowing us to describe relevant somatic mutations in important genes and to propose a genetic alteration atlas for GBC. In our results, we reported the 14 most altered genes in GBC: arid1a, arid2, atm, ctnnb1, erbb2, erbb3, kmt2c, kmt2d, kras, pik3ca, smad4, tert, tp53, and znf521 in samples from Japan, the United States, Chile, and China. Missense mutations are common among these genes. The annotations of many mutations revealed their importance in cancer development. The observed annotations mentioned that several mutations found in this repository are probably oncogenic, with a putative loss-of-function. In addition, they are hotspot mutations and are probably linked to poor prognosis in other cancers. We identified another 11 genes, which presented a copy number alteration in gallbladder database samples, which are ccnd1, ccnd3, ccne1, cdk12, cdkn2a, cdkn2b, erbb2, erbb3, kras, mdm2, and myc. The findings reported here can help to detect GBC cancer through the development of systems based on genetic alterations, for example, the development of a mutation panel specifically for GBC diagnosis, as well as the creation of prognostic profiles to accomplish the development of GBC and its prevalence.

Somatic genetic aberrations in gallbladder cancer: comparison between Chinese and US patients

Background

Gallbladder cancer (GBC) is often diagnosed at an advanced stage with limited therapeutic options and poor prognosis. The five-year survival rate of this cancer when diagnosed at an advanced stage is below 5%, and the median survival time is less than a year with standard gemcitabine-based chemotherapy. Survival benefit with second-line treatment is unknown. Thus, there is an urgent need for novel treatment strategies and targeted therapy based on next generation sequencing (NGS) may be of value.

Methods

Comprehensive genomic profiling (CGP) was performed with NGS panel on paraffin-embedded tumors from a cohort of 108 Chinese and 107 US GBC patients. Clinical data were collected using an IRB approved protocol from a single-center in US and from China.

Results

In Chinese and US GBC cohorts, an average of 6.4 vs. 3.8 genomic alterations (GAs) were identified per patient. The most frequent alterations were TP53 (69.4%), CDKN2A/B (26%), ERBB2 (18.5%), PIK3CA (17%) and CCNE1 (13%) in Chinese cohort, TP53 (57.9%), CDKN2A/B (25%), SMAD4 (17%), ARID1A (14%), PIK3CA (14%) and ERBB2 (13.1%) in US patients. NFE2L2 mutations were present in 6.5% of Chinese patients and not observed in the US cohort. Interestingly, ERBB2 genetic aberrations were significantly associated with better pathological tumor differentiation and tended to co-occurrence with CDKN2A/B mutations in both the Chinese and US GBC cases. Out of the top 9 dysregulated genetic pathways in cancer, Chinese patients harbored more frequent mutations in ERBB genes (30.6% vs. 19.0%, P=0.04). High frequency of PI3K/mTOR pathway variations was observed in both Chinese (37%) and US cohort (33%) (P=0.5). Additionally, both Chinese and US GBC patients exhibited a relatively high tumor mutational burden (TMB) (17.6% and 17.0%, respectively). In the Chinese cohort, a significant association was seen between direct repair gene alterations and TMB ≥10 muts/Mb (P=0.004).

Conclusions

In our study, over 83% Chinese and 68% US GBC patients had actionable alterations that could potentially guide and influence personalized treatment options. The identification of high TMB, ERBB2, CDKN2A/B, PI3K/mTOR pathway and DNA repair mutations indicated that both Chinese and US GBC patients may benefit from targeted or immune checkpoint inhibitors.

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.

Autologous tumor‑derived microvesicles influence gene expression profiles and enhance protumorigenic chemotactic potential, signal transduction and cellular respiration in gastric cancer cells

Tumor‑derived microvesicles (TMVs) interact with a variety of different cell types within the immune system, including lymphocytes, monocytes, dendritic cells and tumor cells that they have originated from. In the present study, the effects of autologous‑TMVs (auto‑TMVs) on gene expression, chemotaxis, intercellular signaling and cellular metabolism were examined in cells of the gastric cancer (GC) cell line 1415 (GC1415). The effects of auto‑TMVs on mRNA gene expression in GC1415 cells were assessed using pathway‑focused PCR arrays. A chemotaxis assay was performed using the HoloMonitor M4 System. Signaling pathways were evaluated using western blot analysis, and cellular respiration was measured using the Seahorse XF Cell Mito Stress Test. Exposure of the GC1415 cells to auto‑TMVs led to the overexpression (75 genes) and underexpression (96 genes) of genes that are associated with signal transduction, metabolism, chemotaxis, angiogenesis and metastasis. The auto‑TMVs were indicated to induce chemotaxis and activate the PI3K/AKT signaling pathway in GC1415 cells. However, the MAPK/ERK signaling pathway was not indicated to be activated. Furthermore, studies on cellular respiration in GC1415 cells exposed to auto‑TMVs demonstrated a metabolic shift to glycolysis. The results of the current study thus indicate that auto‑TMVs may exert an effect on tumor cell function.

Gallbladder cancer harboring ERBB2 mutation on the primary and metastatic site: A case report

BACKGROUND

Bile duct cancer constitutes gallbladder cancer (GBC), intrahepatic cholangiocarcinoma (ICA), and extrahepatic cholangiocarcinoma (ECA). These three entities show morphological and immunohistochemical resemblance so that it is difficult to differentiate between primary ICA and liver metastasis of GBC, which sometimes becomes a point of discussion in clinical practice. Although these cancers demonstrate significant differences in their mutational landscape, several reports demonstrated shared genomic alteration in paired primary and metastatic site aids in distinguishing metastatic recurrence from second primary cancers.

CASE SUMMARY

We present a 73-year-old female patient who underwent curative resection for GBC harboring epidermal growth factor receptor 2 (ERBB2) activating mutation on next-generation sequencing (NGS)-based genomic testing. One year later, a hepatic lesion was observed on follow-up imaging and she underwent surgical resection for a pathological diagnosis. The histological findings of the hepatic lesion were similar to those of the primary lesion. Additionally, using NGS panel testing, the hepatic lesion was found to have ERBB2 activating mutation, which is the identical mutation detected in the sequencing result of the primary site. ERBB2 activating mutation occurs more frequently in GBC than ICA and ECA. Therefore, in the present case, we think this molecular finding potentiated the diagnosis of the liver mass toward a metastatic recurrence. Additionally, this patient underwent HER2-targeted treatment with lapatinib in combination with capecitabin and obtained clinical benefit.

CONCLUSION

This case illustrated NGS panel usefulness in distinguishing GBC recurrence from second primary cancer and HER2-targeted agent efficacy on ERBB2 mutated GBC.