Pathogenesis Of Gallbladder Cancer Research Articles

Ginsenoside Rg3 activates the immune function of CD8+ T cells via circFOXP1-miR-4477a-PD-L1 axis to induce ferroptosis in gallbladder cancer.

Gallbladder cancer (GBC) is the most common and leading cause of cancer-associated mortality among biliary tract carcinomas worldwide and there is no specific drug for treatment. Activation of CD8+ T cell immune activity is one of the strategies to improve GBC treatment. This study is aimed to investigate the role of Ginsenoside Rg3 on CD8+ T cell activation and pathogenesis of GBC. In GBC cells, Rg3 administration led to the significant reduction of circFOXP1 and PD-L1 as measured by Quantitative real-time polymerase chain reaction (RT-qPCR) and Western blotting. Mechanistically, circFOXP1 acted as the sponge of miR-4477a to regulate PD-L1 expression as demonstrated by RNA pull-down assay and dual luciferase reporter assay. Rg3 treatment enhanced the activity of CD8+ T cells by inhibiting thecircFOXP1/miR-4477a/PD-L1 signaling axis. Besides, Rg3 administration induced lipid oxidation and ROS reduction as detected by Flow cytometry, resulting in ferroptosis via theinactivation of circFOXP1/miR-4477a/PD-L1 axis. Ferroptosis inhibitor Fer-1 administration could reverse the beneficial effects caused by Rg3 treatment while ferroptosis inducer Erastin treatment enhanced the effects. Moreover, Rg3 gavage alleviated tumor growth and elevated ferroptosis and apoptosis in tumor tissues, which were prevented by PD-L1 overexpression. Furthermore, Rg3 was demonstrated to activate the function of CD8+ T cells via regulating thecircFOXP1-miR-4477a-PD-L1 signaling axis in vivo. Rg3 inactivated thecircFOXP1-miR-4477a-PD-L1 signaling axis to activate the immune function of CD8+ T cells, thereby inducing ferroptosis and apoptosis in GBC cells. This research recognizes the mechanism of Rg3-mediated anti-cancer effect and offers evidence for the potentiality of Rg3 in clinical application for GBC therapy.

Establishment and characterization of a novel human gallbladder cancer cell line, GBC-X1

In this study, we successfully established a novel gallbladder cancer cell line, designated as GBC-X1, derived from a primary tumor of a gallbladder cancer patient. By comprehensively analyzing the cell line’s phenotype, molecular characteristics, biomarkers, and histological characteristics, we confirmed that GBC-X1 serves as a valuable model for investigating the pathogenesis of gallbladder cancer and developing therapeutic agents. GBC-X1 has been continuously cultured for one year, with over 60 stable passages. Morphologically, GBC-X1 exhibits typical features of epithelial tumors. The population doubling time of GBC-X1 is 32 h. STR analysis validated a high consistency between GBC-X1 and the patient’s primary tumor. Karyotype analysis revealed an abnormal hypertetraploid karyotype for GBC-X1, characterized by representative karyotypes of 98, XXXX del (4) p (12) del (5) p (21) der (10). Under suspension culture conditions, GBC-X1 efficiently forms tumor balls, while subcutaneous inoculation of GBC-X1 cells into NXG mice leads to xenograft formation with a rate of 80%. Drug sensitivity testing demonstrated that GBC-X1 is resistant to oxaliplatin and sensitive to 5-FU, gemcitabine, and paclitaxel. Immunohistochemistry revealed positive expression of CK7, CK19, E-cadherin, MMP-2, CD44, SOX2, and TP53 in GBC-X1 cells, weak positive expression of Vimentin, and a Ki67 positive rate of 35%. Our research highlights GBC-X1 as a novel gallbladder cancer cell line and emphasizes its potential as an effective experimental model for investigating the pathogenesis of gallbladder cancer and drug development.

Expression Pattern of Estrogen Receptor Alpha and Progesterone Receptor in Gallbladder Carcinoma and Their Association with Clinicopathological Parameters and Overall Survival.

Gallbladder cancer (GBC) is a highly aggressive malignant tumor with a poor prognosis. Despite being first described two centuries ago, there are no targeted therapies available beyond conventional cytotoxic therapy. Epidemiological studies have shown that the incidence of gallbladder cancer is higher in females than males. This suggests that the gallbladder may be a female sex hormone-responsive organ, and these hormones might be involved in the pathogenesis of gallbladder cancer. Therefore, we aimed to analyze the expression of ERα and PR in GBC and correlate their expression with clinicopathological variables and overall survival. A total of 235 histopathologically diagnosed GBC cases were included in this hospital-based cross-sectional study. Clinicopathological data were collected, and the expression of ERα and PR was evaluated by immunohistochemistry. The mean age of this study population was 55.47 ± 8.45 with range 28-87years. Females were predominated over male with a male-to-female ratio of 1:3.5. Positive nuclear expression of the ERα and PR was found in 13 (5.5%) and eight (3.4%) cases, respectively. Apart from nuclear staining, cytoplasmic expression of ERα and PR was found in three (1.2%) and 31 (13.2%) cases, respectively. Higher percentage of positive nuclear expression of ER was found in < 50years age (p value = 0.04), parity > 4 (p value = 0.02), advanced pT stage (T3) (p value = 0.01), lymphovascular invasion (p value = 0.02), and liver invasion (p value = 0.04) which were statistically significant. Higher percentage of PR expression was also observed in < 50years age (p value = 0.01), and tumor associated with gallstone (p value = 0.04). There was no significant correlation between cytoplasmic expression of ER, PR, and clinicopathological variables. In multivariate analysis, there was no significant correlation between ER or PR positive expression and overall survival. Although nuclear expression of ERα was significantly associated with progressive disease factors but the positive expression was found in very small percentage of GBC cases. So anti-hormone therapy might be an option in patient with ER α positive gallbladder carcinoma.

Comprehensive single-cell analysis deciphered microenvironmental dynamics and immune regulator olfactomedin 4 in pathogenesis of gallbladder cancer

ObjectiveElucidating complex ecosystems and molecular features of gallbladder cancer (GBC) and benign gallbladder diseases is pivotal to proactive cancer prevention and optimal therapeutic intervention.DesignWe performed single-cell transcriptome analysis on 230...

Metagenomic Analysis of Biliary Microbial Flora in Patients with Gallbladder Cancer or Gallstones-Associated Chronic Cholecystitis

Biliary dysbiosis is associated with gallbladder cancer (GBC). We aimed to look for biliary bacteria specifically detected in GBC patients. We used 16S rRNA-based metagenomic analysis to elucidate biliary microbiota in 30 GBC and 30 gallstones-associated chronic cholecystitis patients. Relative abundance of five genera, Streptococcus, Enterococcus, Halomonas, Escherichia and Caulobacter was significantly associated with GBC. Of 15-species, 7 were detected significantly higher in GBC, Streptococcus anginosus, Streptococcus constellatus, Streptococcus intermedius, Actinomyces bowdenii, Actinomyces israelii, Actinomyces gerencseriae, and Escherichia fergusonii were biosafety level-2 infectious bacteria; other 8 species were biosafety level-1 bacteria. These bacterial species may be involved in pathogenesis of GBC.

Environmental and Metabolic Risk Factors Linked to Gallbladder Dysplasia.

Gallbladder disorders encompass a spectrum from congenital anomalies to inflammatory and neoplastic conditions, frequently requiring surgical intervention. Epithelial abnormalities like adenoma and metaplasia have the potential to progress to carcinoma, emphasizing the importance of histopathological assessment for early detection of malignancy. Gallbladder cancer (GBC) may be incidentally discovered during cholecystectomy for presumed benign conditions, underscoring the need for a thorough examination. However, the lack of clarity regarding the molecular mechanisms of GBC has impeded diagnostic and therapeutic advancements. Timely detection is crucial due to GBC's aggressive nature and poor prognosis. Chronic inflammation plays a central role in carcinogenesis, causing DNA damage and oncogenic alterations due to persistent insults. Inflammatory cytokines and microRNAs are among the various mediators contributing to this process. Gallbladder calcifications, particularly stippled ones, may signal malignancy and warrant preemptive removal. Molecular pathways involving mutations in oncogenes and tumor suppressor genes drive GBC pathogenesis, with proposed sequences such as gallstone-induced inflammation leading to carcinoma formation. Understanding these mechanisms, alongside evaluating mucin characteristics and gene mutations, can deepen comprehension of GBC's pathophysiology. This, in turn, facilitates the identification of high-risk individuals and the development of improved treatment strategies, ultimately enhancing patient outcomes. Thus, in this review, our aim has been to underscore the primary mechanisms underlying the development of gallbladder dysplasia and neoplasia.

Epidemiology of gallbladder cancer in India 2018–2023

ABSTRACT India is a high-incidence area for gallbladder cancer (GBC), contributing approximately 10% of the global GBC burden. Within the country, the incidence is notably high in North, North-East, Central, and Eastern regions, whereas it is less common in South and West India. The incidence has been steadily rising in both genders. Patients often present with advanced disease, which carries a dismal prognosis. Unlike the West, GBC in India typically affects younger patients in their fifth and sixth decades of life. Gallstones are present in 80% of Indian GBC patients, increasing the vulnerability of the gallbladder to mucosal injury. However, the incidence of GBC is disproportionate to the prevalence of gallstones in the country. Additional cofactors such as older age, lower socioeconomic status, chronic Salmonella typhi infection, Helicobacter pylori infection, exposure to pollutants, heavy metals, chemicals, adulterated mustard oil, and smoking in patients with gallstones have been identified as promoters of carcinogenesis. These risk factors act additively, resulting in a higher incidence of GBC and accelerating its development. Environmental risk factors, including soil and water contamination by industrial wastes, agricultural effluents, and human sewage, have also been identified as putative risk factors. The combination of a toxic environment, a vulnerable gallbladder, and a susceptible host plays a key role in the pathogenesis of GBC in India. Large multicentric comprehensive studies are required to assess the attributable risk of each identified putative risk factor. This will aid in formulating cost-effective national strategies to prevent GBC-related mortality in the country. Meanwhile, maintaining a high index of suspicion to detect incidental GBC and improving access to health-care facilities for appropriate management of gallstones will help reduce GBC-related mortality.

Gallbladder cancer-associated genetic variants rs1003349 and rs1004030 regulate MMP14 expression by altering SOX10 and MYB binding sites.

The pathogenesis of gallbladder cancer is complex, involving environmental and genetic risk factors. The matrix metallopeptidase 14 (MMP14) alters the tumor microenvironment and promotes tumorigenesis. In this study, we have characterized the role of the MMP14 promoter variants rs1004030 and rs1003049 in gallbladder cancer pathogenesis. Previously we have shown the association of rs1004030 and rs1003049 with GBC and allele-specific differential expression of MMP14 in GBC patients. These variants reside within the cis-Regulatory Element (CRE) with high DNase and H3K4me3 signals, suggesting an active regulatory role in MMP14 expression. The luciferase-based reporter assay showed the role of promoter variants on expression levels in two GBC cell lines. Deleting the 119bp promoter region surrounding the variants rs1004030 and rs1003049 by CRISPR-Cas9 genome editing resulted in reduced MMP14 expression in G415 cells. Electrophoretic mobility shift assay shows the presence of risk allele 'C'/'G' at rs1004030 and rs1003049 create binding sites for transcription factors SOX10 and MYB, respectively. Further, stable knockdown of these transcription factors in G415 and TGBC1TKB cells showed reduced expression of MMP14. However, in both GBC cells, ectopic expression of these transcription factors increased the expression of MMP14. Rescue of MYB and SOX10 expression levels showed a significant increase in luciferase activity only in risk allele carrying constructs. In conclusion, our study unveils a mechanistic role of the MMP14 promoter variants rs1004030 and rs1003049 in gallbladder cancer.

DNA methylation of RUNX3 promotes the progression of gallbladder cancer through repressing SLC7A11-mediated ferroptosis

Gallbladder cancer (GBC) is a type of rare but highly aggressive cancer with a dismal prognosis. Runt-related transcription factor 3 (RUNX3), a member of the runt-domain family, and its promoter methylation have been widely observed in a variety of human malignancies. However, the biological function and underlying mechanism of RUNX3 in GBC remain elusive. In this study, bisulfate sequencing PCR (BSP), Western blot, and qPCR were applied to identify the expression level and DNA methylation level of RUNX3 in GBC tissues and cells. The transcriptional relationship between RUNX3 and Inhibitor of growth 1 (ING1) was validated by dual-luciferase reporter assay and ChIP assay. A series of gain-of-function and loss-of-function assays were performed to detect the function and the regulatory relationship of RUNX3 in vitro and in vivo. RUNX3 was aberrantly downregulated in GBC cells and tissues caused by DNA Methyltransferase 1 (DNMT1)-mediated methylation, and downregulation of RUNX3 is associated with poor prognosis of GBC patients. Functional experiments reveal that RUNX3 can induce ferroptosis of GBC cells in vitro and in vivo. Mechanistically, RUNX3 induces ferroptosis by activating ING1 transcription, thereby repressing SLC7A11 in a p53-dependent manner. In conclusion, the downregulation of RUNX3 is mediated by DNA methylation, which promotes the pathogenesis of gallbladder cancer through attenuating SLC7A11-mediated ferroptosis. This study gives novel insights into the role of RUNX3 in the ferroptosis of GBC cells, which may contribute to developing potential treatment targets for GBC.

Non-coding RNAs as potential biomarkers of gallbladder cancer.

Gallbladder cancer (GBC) performs strongly invasive and poor prognosis, and adenocarcinoma is the most common histological type in it. Statistically, the 5-year survival rate of patients with advanced GBC is less than 5%. Such dismal outcome might be caused by chemotherapy resistance and native biology of tumor cells, regardless of emerging therapeutic strategies. Early diagnosis, depending on biomarkers, receptors and secretive proteins, is more important than clinical therapy, guiding the pathologic stage of cancer and the choice of medication. Therefore, it is in urgent need to understand the specific pathogenesis of GBC and strive to find promising novel biomarkers for early screening in GBC. Non-coding RNAs (ncRNAs), especially microRNAs (miRNAs, miRs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are confirmed to participate in and regulate the occurrence and development of GBC. Exceptionally, lncRNAs and circRNAs could act as competing endogenous RNAs (ceRNAs) containing binding sites for miRNAs and crosstalk with miRNAs to target regulatory downstream protein-coding messenger RNAs (mRNAs), thus affecting the expression levels of specific proteins to participate in and regulate the development and progression of GBC. It follows that ncRNAs may become promising biomarkers and potential therapeutic targets for GBC. In this review, we mainly summarize the recent research progress of miRNAs and lncRNAs in regulating the development and progression of GBC, chemoresistance, and predicting the prognosis of patients, and highlight the potential applications of the lncRNA/circRNA-miRNA-mRNA cross-regulatory networks in early diagnosis, chemoresistance, and prognostic evaluation, aiming to better understand the pathogenesis of GBC and develop new diagnostic and therapeutic strategies.

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.

MAP kinase and mammalian target of rapamycin are main pathways of gallbladder carcinogenesis: results from bioinformatic analysis of next generation sequencing data from a hospital-based cohort (NCT05404347).

Gallbladder Cancer (GBC) is one of the most common cancers of the biliary tract and the third commonest gastrointestinal (GI) malignancy worldwide. The disease is characterized by the late presentation and poor outcome despite treatment, and hence, newer therapies and targets need to be identified. The current study investigated various functionally enriched pathways in GBC pathogenesis involving the genes identified through Next Generation Sequencing (NGS) in a hospital-based cohort. The Pathway enrichment analysis and Gene Ontology (GO) were carried out after NGS, followed by the construction of the protein-protein interaction (PPI) network to discover associations among the genes. Of the thirty-three patients with GBC who were screened through next-generation sequencing (NGS), 27somatic mutations were identified. These mutations involved a total of 14 genes. The p53 and KRAS were commonly found to be mutated, while mutations in other genes were seen in one case each, the mean number of mutations were 1.2, and maximum mutation in a single case (eight) was seen in one case. The bioinformatics analysis identified MAP kinase, PI3K-AKT, EGF/EGFR, and Focal Adhesion PI3K-AKT-mTOR signaling pathways and cross-talk between these. The results suggest that the complex crosstalk between the mTOR, MAPK, and multiple interacting cell signaling cascades can promote GBC progression, and hence, mTOR-MAPK targeted treatment will be an attractive option.

Integrative network-based approaches identified systems-level molecular signatures associated with gallbladder cancer pathogenesis from gallstone diseases

Gallbladder cancer (GBC) is one of the most fatal malignancies of the biliary tract system and is ranked sixth among the neoplasms of the gastrointestinal tract. Gallstone disease (GSD) is considered the major risk factor for GBC. However, the underlying molecular mechanism of GBC pathogenesis from different stages of GSD is not yet clearly understood. We analyzed transcriptomic datasets of GBC with reference to GSD of three different follow-up periods, i.e.,GBC vs. GSD3 (1-3 years), GBCvs. GSD5 (5-10 years), andGBC vs. GSD10 (more than 10 years). We identified overlapping and specific molecular signatures in GBC compared with GSD at three different follow-up periods. Using integrative network biology approaches, such as protein-protein interaction network analysis, transcriptional regulatory network analysis, and miRNA-target gene network analysis, we have identified a few hub genes. The hub genes identified from GBC vs. GSD3, GBC vs. GSD5, and GBC vs. GSD10 were directly or indirectly associated with cancer progression and initiation from GSD. Functional enrichment analysis indicated significant correlation between GSD and GBC pathogenesis. The identified hub genes can be used for future targeted validation to develop potential diagnostic, prognostic, or therapeutic biomarkers in GBC.

DNA Methylation of RUNX3 Promotes Pathogenesis of Gallbladder Cancer through Attenuates β-Catenin/T Cell Factors

Introduction: Gallbladder cancer (GBC) is a highly aggressive malignancy of the biliary tract with poor prognosis and very dismal survival rates. DNA methylation is a key epigenetic reprogramming mechanism that plays a vital role in carcinogenesis. In this study we investigate the functional role, epigenetic change and its mechanism of RUNX3 in GBC.

LncRNA RP11-147L13.8 suppresses metastasis and chemo-resistance by modulating the phosphorylation of c-Jun protein in GBC

Long non-coding RNAs (lncRNAs) have been identified as critical contributors in tumor progression for many types of cancer. However, their functions in gallbladder cancer (GBC) have not been systematically clarified. In this study, the clinical significance, biological function, and underlying mechanism of lncRNA RP11-147L13.8 in GBC were investigated. The quantitative real-time PCR result indicated that lncRNA RP11-147L13.8 was found to be recurrently downregulated in GBC tumor samples. Kaplan-Meier analysis revealed that decreased lncRNA RP11-147L13.8 expression level was associated with poor survival of GBC patients (p = 0.025). Then, both in vitro and in vivo experiments elucidated that the overexpression of lncRNA RP11-147L13.8 suppressed the migration and invasion abilities of GBC cells and promoted the sensitivity to gemcitabine of GBC cells. Furthermore, we found that lncRNA RP11-147L13.8 physically interacted with c-Jun protein and decreased the phosphorylation on serine-73 (c-Jun-Ser73), which might cause the enhancement of the migration, invasion, and sensitivity to gemcitabine of GBC tumor cells. In conclusion, our study identified lncRNA RP11-147L13.8 as a promising prognostic indicator for patients with GBC, providing insights into the molecular pathogenesis of GBC. lncRNA RP11-147L13.8 is a potential therapeutic combination for gemcitabine in GBC treatment.

An Integrative Systems Biology Approach Identifies Molecular Signatures Associated with Gallbladder Cancer Pathogenesis

Gallbladder cancer (GBC) has a lower incidence rate among the population relative to other cancer types but is a major contributor to the total number of biliary tract system cancer cases. GBC is distinguished from other malignancies by its high mortality, marked geographical variation and poor prognosis. To date no systemic targeted therapy is available for GBC. The main objective of this study is to determine the molecular signatures correlated with GBC development using integrative systems level approaches. We performed analysis of publicly available transcriptomic data to identify differentially regulated genes and pathways. Differential co-expression network analysis and transcriptional regulatory network analysis was performed to identify hub genes and hub transcription factors (TFs) associated with GBC pathogenesis and progression. Subsequently, we assessed the epithelial-mesenchymal transition (EMT) status of the hub genes using a combination of three scoring methods. The identified hub genes including, CDC6, MAPK15, CCNB2, BIRC7, L3MBTL1 were found to be regulators of cell cycle components which suggested their potential role in GBC pathogenesis and progression.

Soluble cluster of differentiation 14 levels elevated in bile from gallbladder cancer cases from Shanghai, China

Elevated systemic levels of soluble cluster of differentiation 14 (sCD14) have been associated with gallbladder cancer (GBC), but the association with sCD14 levels within the gallbladder has not been investigated. Here, we evaluated sCD14 in the bile of 41 GBC cases and 117 gallstone controls with data on 65 bile inflammation markers. We examined the relationship between bile sCD14 levels and GBC using logistic regression and stratified the analysis by stage. We included GBC-associated inflammatory biomarkers in the model to evaluate the influence of local inflammation. Bile sCD14 levels (third versus first tertile) were associated with GBC (adjusted odds ratio [OR]: 3.0, 95% confidence interval [CI]: 1.2–8.0). The association was equally strong for stage I/II (OR: 3.3, 95% CI: 0.9–15.6) and stage III/IV (OR: 3.2, 95% CI: 1.0–12.4) cancers. Including the GBC-associated inflammatory markers in the model removed the association between bile sCD14 and GBC (OR: 1.0, 95% CI: 0.3–3.5). The findings suggest that immune activation within the gallbladder may be related to GBC development, and the effect of sCD14 is influenced by inflammation. Similar associations across tumor stages suggest that elevated bile sCD14 levels may reflect changes early in GBC pathogenesis. Associations between GBC and sCD14 levels in both bile and plasma suggest sCD14 could be a potential biomarker for GBC.

An overview on possible links between aflatoxin B1 exposure and gallbladder cancer.

Gallbladder cancer (GBC) is one of the most common sites for biliary tract cancers. It has a worldwide distribution being endemic in South America and Southern Asia. These high GBC rates have previously been linked to the determinants of health such as nutrition, genetics, lifestyle, and environment. Exposure to aflatoxin B1 (AFB1), a human carcinogen, is suggested to be involved with GBC development. This work aims to analyse the interplay of social, lifestyle, and genetic predisposing factors to GBC. AFB1 plays a pivotal role in carcinogenic onset by genetic and epigenetic modifications. AFB1 can induce molecular changes involved in the GBC pathogenesis, such as overexpression of UCHL1 gene, mutagenesis of TP53 gene, abnormal expression of oncogenes BCL-2, and aberrantly methylation of ERBB family receptors. However, a large-scale scientific cooperation is needed to confirm these molecular links through which AFB1 may increase the GBC risk. For that, monitoring AFB1 exposure through AF-albumin and AFB1-lysine will clarify the level of exposure of the population to AFB1 in the GBC hotspot. Further, analyses of AFB1-adduct concentrations in GBC cases (fatal and non-fatal) are needed to understanding if AF contamination can trigger gallbladder cancer.

Genetic association of MMP14 promoter variants and their functional significance in gallbladder cancer pathogenesis.

Gallbladder cancer (GBC) is relatively rare but shows high frequency in certain geographical regions and ethnic groups, which include Northern and Eastern states of India. Previous studies in India have indicated the possible role of genetic predisposition in GBC pathogenesis. Although matrix metalloproteinase-14 (MMP14) is known modulator of tumour microenvironment and tumorigenesis and TCGA data also suggests its upregulation yet, its role in genetic predisposition for GBC is completely unknown. We explored MMP14 promoter genetic variants as risk factors and their implication in expression modulation and the pathogenesis of GBC. We genotyped all single nucleotide polymorphisms of MMP14 promoter by Sanger's sequencing in approximately 300 GBC and 300 control study subjects of Indian ethnicity and, in 26 GBC tissue samples. Protein expression of MMP14 in GBC tissue samples was checked by immunohistochemistry. In vitro luciferase reporter assay was carried out to elucidate role of promoter genetic variants on expression levels in two different cell lines. MMP14 promoter variants, rs1003349 (p value = 0.0008) and rs1004030 (p value = 0.0001) were significantly associated with GBC. Luciferase reporter assay showed high expression for risk alleles of both the SNPs. Genotype-phenotype correlation for rs1003349 and rs1004030, in patient sample, confirmed that risk allele carriers had higher expression levels of MMP14; moreover, the correlation pattern matched with genetic association models. Overall, this study unravels the association of MMP14 promoter SNPs with GBC which contribute to pathogenesis by increasing its expression.

Deciphering the impact of missense mutations on structure and dynamics of SMAD4 protein involved in pathogenesis of gall bladder cancer

Gall bladder cancer (GBC) is the most common malignancy of biliary tract cancer associated with high mortality rate and poor prognosis due to lack of suitable biomarkers. In this study, we explored the structural and functional effects of different missense mutations occurs in SMAD4 that was associated with the development of GBC. We utilized in silico methods to predict the harmful effects of nonsynonymous missense mutations and monitored the stability of protein. We found that all mutations (D351N, G352E, R361C, R361H, E526Q) associated with SMAD4 were deleterious in nature resulting in the formation of deformed or unstable protein structure. Molecular dynamics simulation studies revealed how these mutations affect protein stability, structure, conformation and function. We observed, different mutants increase the compactness and rigidity of SMAD4 protein, alter secondary structure composition, decrease the surface area and protein-ligand interaction and affect its conformation. Findings of current work indicated that the analyzed mutations might affect the structure of protein and its caliber to interact with other molecules, which probably related to functional impairment of SMAD4 upon D351N, G352E, R361C, R361H, E526Q mutations and their involvement in cancer. Hence, the present study has significance of rational drug design and further increase our understanding of GBC development. Communicated by Ramaswamy H. Sarma