Carcinoma of the gallbladder

Role of m5C methylation in digestive system tumors (Review)

Currently, the incidence of digestive system tumors has been increasing annually, thus becoming a prevalent cause of cancer‑related mortalities. Although significant strides have been made in targeting the molecular mechanisms that underpin the development of these tumors, their treatment and prognosis still pose substantial challenges. This is primarily due to the ambiguity of early diagnostic indicators and the fact that most digestive system tumors are detected at an advanced stage. However, epigenetic modifications are capable of altering the expression of oncogenes and regulating biological processes in cancer. In recent years, the study of methylation in relation to tumor pathogenesis has become a focus of prominent research. Among the various types of methylation, 5‑methylcytosine (m5C) methylation plays a crucial role in the development of digestive system tumors and is anticipated to serve as a novel therapeutic target. However, to date, a comprehensive and systematic review concerning the role of m5C methylation in digestive system tumors is lacking. Consequently, the present study reviewed the role of m5C methylation in digestive system tumors such as esophageal cancer, gastric cancer and hepatocellular carcinoma, with the aim of providing a valuable reference for future research endeavors.

Perforated Calculous Cholecystitis and Incidental Squamous Cell Carcinoma of the Gallbladder-A Complex Relationship with a Difficult Management in the Acute Setting

The worldwide prevalence of gallstones (GSs) is estimated to be between 10% and 15% in the general population. Gallbladder carcinoma (GBC) is the most common biliary tract neoplasia, and it is characterized by highly aggressive behavior and poor overall prognosis. Long-standing GSs and chronic inflammatory state represent the most common risk factors for GBC, promoting a carcinogenic microenvironment. Long-standing GSs expose patients to potentially severe surgical and oncological complications. A 71-year-old gentleman, who had never experienced biliary symptoms and had diabetes mellitus (DM), presented with severe peritonitis due to perforated acute calculous cholecystitis. The patient underwent an emergent laparotomic cholecystectomy. Histopathology found a rare pT2b poorly differentiated squamocellular carcinoma of the gallbladder. Although more difficult due to the concomitant inflammatory context, it is critical to identify suspicious lesions during preoperative imaging in patients at high risk of malignancy presenting with complex acute gallbladder pathologies. A review of the literature was conducted to gain a deeper insight into the relationship between long-standing GSs and GBC, evaluating also the difficult diagnosis and management of malignancy in the acute setting. Considering the existing literature, the choice to pursue a prophylactic cholecystectomy may be justifiable in selected asymptomatic GS patients at high risk for GBC.

Incidental T1a Gallbladder Cancer with Signet Ring Cell Carcinoma Following Laparoscopic Cholecystectomy: A Case Report

INTRODUCTION

Signet ring cell carcinoma (SRC) of the gallbladder is a rare type of gallbladder cancer. We report a case of SRC of the gallbladder that was characterized by the diffuse presence of SRC on the gallbladder mucosa and diagnosed after cholecystectomy.

CASE PRESENTATION

A 40-year-old man was referred to our department with upper abdominal pain and vomiting. Based on the findings of blood tests, computed tomography, and magnetic resonance imaging, acute cholecystitis was suspected, and emergency laparoscopic cholecystectomy was performed. Intraoperative findings showed mild inflammation. Although the tumor remained within the mucosa, tumor cell infiltration was suspected at the edge of cystic duct pathologically. Although additional endoscopic ultrasound and endoscopic retrograde cholangiography showed that horizontal extension into the residual cholecystic duct was suspected, there was no evidence of invasion into the common bile duct, lymph node metastasis, or distant metastasis. One and a half months after cholecystectomy, the patient underwent extrahepatic bile duct resection, lymph node dissection, and bile duct jejunal anastomosis. The postoperative course was uneventful, and the patient was discharged on the 10th postoperative day. Postoperative pathological analysis showed no obvious residual tumor tissue in the common bile duct or choledochal duct margins, and no metastasis in the submitted lymph nodes. Based on the above, a diagnosis of pT1aN0M0, pStage IA SRC was made. As no lymph node metastasis was observed, it was decided to follow up the patient without initiating postoperative chemotherapy, and the patient has been recurrence-free for 12 months after surgery.

CONCLUSIONS

We describe an incidentally discovered case of intramucosal SRC diffusely spreading throughout the gallbladder after cholecystectomy for acute cholecystitis.

Prediabetes persistence or remission and subsequent risk of gallbladder cancer: A nationwide cohort study

BACKGROUND & AIMS

Hyperglycemia is associated with an increased risk of gallbladder cancer (GBC), potentially by inhibiting gallbladder motility and inducing prolonged cholestasis. Although intermediate hyperglycemia (or prediabetes) is highly reversible, evidence is lacking about whether prediabetes persistence or remission is associated with an altered GBC risk.

METHODS

This nationwide cohort study included 6058,662 adults without diabetes or cancer who underwent national health examinations twice in 2-year intervals between 2009 (S1) and 2011 (S2) and were followed-up until 2018. Prediabetes was defined as a fasting plasma glucose level of 100-125 mg/dL. We categorized changes in prediabetes status into: stable normoglycemia, new-onset prediabetes, prediabetes remission, and persistent prediabetes groups. GBC risk was estimated using Cox proportional hazards models, after adjusting for potential confounders.

RESULTS

During 38.6 million person-years (median 6.4 years) of follow-up, 1349 new GBC cases were identified. Among 1409,474 individuals with prediabetes at S1, 768,515 achieved prediabetes remission at S2, outnumbering the 640,959 individuals with persistent prediabetes. GBC incidence probability was consistently higher among individuals with persistent prediabetes than in individuals with stable normoglycemia or prediabetes remission (all log-rank P < 0.01). Compared with stable normoglycemia, persistent prediabetes was associated with increased GBC risk (adjusted hazard ratio [aHR], 95 % CI: 1.21, 1.04 to 1.41). The aHRs of GBC were 1.14 (95 % CI, 0.99 to 1.33) and 1.03 (95 % CI, 0.88 to 1.21) for new-onset prediabetes and prediabetes remission, respectively.

CONCLUSIONS

Individuals with persistent prediabetes had a significantly increased risk of GBC, whereas those with prediabetes remission had no increased risk. Achieving prediabetes remission has a significant potential to reduce the risk of GBC.

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 the circFOXP1/miR-4477a/PD-L1 signaling axis. Besides, Rg3 administration induced lipid oxidation and ROS reduction as detected by Flow cytometry, resulting in ferroptosis via the inactivation 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 the circFOXP1-miR-4477a-PD-L1 signaling axis in vivo. Rg3 inactivated the circFOXP1-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.

Analysis of neoadjuvant therapy effect on 30-day postoperative outcomes in gallbladder cancer

Background

The role of neoadjuvant therapy (NAT) in gallbladder cancer (GBC) is not well established. We sought to evaluate the effect of NAT on postoperative outcomes following surgical resection of GBC. We hypothesized that patients receiving NAT would have similar rates of 30-day mortality, readmission, and postoperative complications (e.g. bile leakage and liver failure) compared to those who did not receive NAT.

Methods

The 2014-2017 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) Procedure-Targeted Hepatectomy database was queried for patients that underwent surgery for GBC. Propensity scores were calculated to match patients in a 1:2 ratio based on age, comorbidities, functional status, and tumor staging.

Results

A total of 37 patients undergoing NAT were matched to 74 patients without NAT. There was no difference in any matched characteristics. Compared to the NAT group, the no NAT cohort had similar rates of postoperative bile leakage (NAT 13.5 % vs. no NAT 10.8 %, p = 0.31), postoperative liver failure (5.4 %, vs. 8.1 %, p = 0.60), 30-day readmission (10.8 % vs. 10.8 %, p = 1.00), and 30-day mortality (10.8 % vs. 2.7 %, p = 0.075). All 30-day complications were similar except for a higher rate of postoperative blood transfusion (NAT 32.4 % vs. no NAT 10.8 %, p = 0.005).

Conclusion

In patients undergoing surgical resection for GBC, those with and without NAT had similar rates of readmission and 30-day mortality, however NAT was associated with an increased risk for transfusion. Despite use of a large national database, this study may be underpowered to adequately assess the effect of NAT on perioperative GBC outcomes and thus warrants further investigation.

Is cross-species horizontal gene transfer responsible for gallbladder carcinogenesis

BACKGROUND

Cross-species horizontal gene transfer (HGT) involves the transfer of genetic material between different species of organisms. In recent years, mounting evidence has emerged that cross-species HGT does take place and may play a role in the development and progression of diseases.

METHODS

Transcriptomic data obtained from patients with gallbladder cancer (GBC) was assessed for the differential expression of antisense RNAs (asRNAs). The Basic Local Alignment Search Tool (BLAST) was used for cross-species analysis with viral, bacterial, fungal, and ancient human genomes to elucidate the evolutionary cross species origins of these differential asRNAs. Functional enrichment analysis and text mining were conducted and a network of asRNAs targeting mRNAs was constructed to understand the function of differential asRNAs better.

RESULTS

A total of 17 differentially expressed antisense RNAs (asRNAs) were identified in gallbladder cancer tissue compared to that of normal gallbladder. BLAST analysis of 15 of these asRNAs (AFAP1-AS1, HMGA2-AS1, MNX1-AS1, SLC2A1-AS1, BBOX1-AS1, ELFN1-AS1, TRPM2-AS, DNAH17-AS1, DCST1-AS1, VPS9D1-AS1, MIR1-1HG-AS1, HAND2-AS1, PGM5P4-AS1, PGM5P3-AS1, and MAGI2-AS) showed varying degree of similarities with bacterial and viral genomes, except for UNC5B-AS1 and SOX21-AS1, which were conserved during evolution. Two of these 15 asRNAs, (VPS9D1-AS1 and SLC2A1-AS1) exhibited a high degree of similarity with viral genomes (Chikungunya virus, Human immunodeficiency virus 1, Stealth virus 1, and Zika virus) and bacterial genomes including (Staphylococcus sp., Bradyrhizobium sp., Pasteurella multocida sp., and, Klebsiella pneumoniae sp.), indicating potential HGT during evolution.

CONCLUSION

The results provide novel evidence supporting the hypothesis that differentially expressed asRNAs in GBC exhibit varying sequence similarity with bacterial, viral, and ancient human genomes, indicating a potential shared evolutionary origin. These non-coding genes are enriched with methylation and were found to be associated with cancer-related pathways, including the P53 and PI3K-AKT signaling pathways, suggesting their possible involvement in tumor development.

Risk Factors and Prognostic Factors in GBC

Background: Gallbladder cancer (GBC) is a rare entity with a poor prognosis, usually discovered late due to nonspecific symptoms; therefore, over the last years, attention has been focused on identifying the risk factors for developing this malignancy in order to provide an early diagnosis, as well as new prognostic factors in order to modulate the long-term evolution of such cases. The aim of this review is to discuss both major risk factors and prognostic factors in GBC for a better understanding and integration of relevant and currently available information. Methods: A literature search was performed using Cochrane Library, PubMed, Google Scholar, Elsevier, and Web of Science; studies published after the year of 2000, in English, were reviewed. Results: Over time, risk factors associated with the development of GBC have been identified, which outline the profile of patients with this disease. The most important prognostic factors in GBC remain TNM staging, safety margin, and R0 status, along with perineural invasion and lymphovascular invasion. Both the technique and experience of the surgeons and a pathological examination that ensures final staging are particularly important and increase the chances of survival of the patients. Conclusions: improvements in surgical techniques and pathological analyses might provide better and more consistent guidance for medical staff in the management of patients with GBC.

Incidentally Detected Gallbladder Carcinoma: Can F-18 FDG PET/CT Aid in Staging and Prognostication?

Purpose

Incidental gallbladder carcinoma (IGBC) is diagnosed in post-cholecystectomy specimens for benign indications, where the role of 2-fluro-2-deoxyglucose positron emission tomography/computed tomography(FDG-PET/CT) is not clearly defined. The present study aimed to assess the benefits of staging and prognosticating with FDG-PET/CT in IGBC.

Materials and Methods

A retrospective observational study from a tertiary-care center from January 2010 to July 2020 was performed. The demographic, clinical, histopathological, and treatment-related histories were collected. FDG-PET/CT-image findings were compared with survival outcomes through telephonic follow-up. The chi-square test was used for comparing frequencies. The univariate and multivariate survival estimates were analyzed using the Kaplan-Meier analysis and the Cox-proportional hazard model, respectively. Log-rank test was used to compare the Kaplan-Meier curves.

Results

The study included 280 postcholecystectomy participants (mean age: 52 ± 11 years; women: 227) of whom 52.1% had open surgery(146/280). Residual disease in the gallbladder fossa (54.8% vs. 36.6%, p = 0.002) and liver infiltration (32.9% vs. 22.4%, p = 0.05) were seen more frequently in open surgery compared to laparoscopic surgery, while anterior abdominal wall deposits were more common in laparoscopy(35.1% vs. 24%,p = 0.041). FDG-PET/CT changed the management in 10% (n = 28) of patients compared to contrast-enhanced CT. The median survival was 14 months (95%CI-10.3-17.7). A higher stage of the disease on the FDG-PET/CT (loco-regional disease-HR 4.86, p = 0.006; metastatic disease-HR 7.53, p < 0.001) and the presence of liver infiltration (HR-1.92, p = 0.003) were independent predictors of poor survival outcomes.

Conclusion

FDG-PET/CT detects residual and metastatic disease in patients with IGBC, enabling the institution of appropriate management and acting as a tool for prognostication of survival.

Prognostic Insights and Survival Analysis of Gallbladder Cancer in Bihar, India: a Prospective Observational Study Emphasizing the Impact of Surgical Intervention on Overall Survival

The aim of this study was to determine the 1- and 3-year overall survival rates. This prospective observational study was conducted at a tertiary care center in Bihar state, India. The study analyzed 228 patients in Bihar with a median age at diagnosis of 55 ± 12.05 years. The most common symptoms included upper abdominal pain (26.3%), weight loss (14%), and ascites (13.6%). The majority of patients presented at stage IV (72.8%), with liver metastasis being prevalent (61.4%). Interventional biliary drainage was performed in 9.6% of cases, and systemic chemotherapy was received by 84.64%, while 15.36% opted for best supportive care. Univariate Cox regression analysis identified Eastern Cooperative Oncology Group (ECOG) performance status, stage, gallstone disease, and surgical intervention as significant risk factors influencing overall survival (OS) (p < 0.001). Multivariate Cox regression analysis confirmed ECOG performance status (p < 0.001), stage (p = 0.039), and surgical intervention (p = 0.038) as independent factors impacting OS. One-year OS rates for stages II, III, and IV were 100%, 97%, and 44%, respectively, while 3-year OS rates were 29%, 4%, and 0%. Surgical intervention significantly influenced OS (p < 0.001). OS for surgical intervention was 28 months, and for inoperable cases, it was 12 months. One- and 3-year OS for surgical intervention were 95% and 11%, while for inoperable cases, they were 41% and 0%, respectively. Patients with gallbladder cancer, particularly in Bihar's Gangetic plains, face poor survival, especially with advanced disease. Adequate surgery improves outcomes, prompting a call for enhanced strategies, particularly for locally advanced GBC.

Deep-learning enabled ultrasound based detection of gallbladder cancer in northern India: a prospective diagnostic study

Background

Gallbladder cancer (GBC) is highly aggressive. Diagnosis of GBC is challenging as benign gallbladder lesions can have similar imaging features. We aim to develop and validate a deep learning (DL) model for the automatic detection of GBC at abdominal ultrasound (US) and compare its diagnostic performance with that of radiologists.

Methods

In this prospective study, a multiscale, second-order pooling-based DL classifier model was trained (training and validation cohorts) using the US data of patients with gallbladder lesions acquired between August 2019 and June 2021 at the Postgraduate Institute of Medical Education and research, a tertiary care hospital in North India. The performance of the DL model to detect GBC was evaluated in a temporally independent test cohort (July 2021-September 2022) and was compared with that of two radiologists.

Findings

The study included 233 patients in the training set (mean age, 48 ± (2SD) 23 years; 142 women), 59 patients in the validation set (mean age, 51.4 ± 19.2 years; 38 women), and 273 patients in the test set (mean age, 50.4 ± 22.1 years; 177 women). In the test set, the DL model had sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of 92.3% (95% CI, 88.1-95.6), 74.4% (95% CI, 65.3-79.9), and 0.887 (95% CI, 0.844-0.930), respectively for detecting GBC which was comparable to both the radiologists. The DL-based approach showed high sensitivity (89.8-93%) and AUC (0.810-0.890) for detecting GBC in the presence of stones, contracted gallbladders, lesion size <10 mm, and neck lesions, which was comparable to both the radiologists (p = 0.052-0.738 for sensitivity and p = 0.061-0.745 for AUC). The sensitivity for DL-based detection of mural thickening type of GBC was significantly greater than one of the radiologists (87.8% vs. 72.8%, p = 0.012), despite a reduced specificity.

Interpretation

The DL-based approach demonstrated diagnostic performance comparable to experienced radiologists in detecting GBC using US. However, multicentre studies are warranted to explore the potential of DL-based diagnosis of GBC fully.

Funding

None.

Treatment Outcomes of Incidental Gallbladder Cancer - Results from a High-Volume Tertiary Care Centre in North India

Gallbladder cancer (GBC) is a lethal disease. Incidentally detected gallbladder cancer (IGBC) presents a unique opportunity for early management and better outcomes. We present the institutional experience of a high-volume tertiary care center in northern India. Retrospective analysis of a prospectively maintained database was performed and data of all IGBC patients between January 2014 to December 2021 was analyzed. There were 125 patients of IGBC among the 750 patients of GBC seen during the study period. Of these 125 patients, 72 (57.6%) patients were not eligible for surgery. Successful completion radical cholecystectomy (CRC) was possible in 37 (69.8%) of the 53 patients who underwent surgery. On univariate analysis, thickness of gallbladder wall 10 mm or more (p < 0.001, OR 19.0, 95% CI 4.58-78.76), pathological stage (p < 0.001, OR 5.8, 95% CI 2.45-14.98) and median delay of 16 weeks or more (p < 0.001, OR 17.0, 95% CI = 4.08-70.76), were associated with inoperability. However, on multivariate analysis only gallbladder wall thickness of 10 mm or more (p < 0.001, AOR 17.9, 95% CI 3.24-98.78) and median delay of 16 weeks or more (p < 0.001, AOR 32.33, 95% CI 6.05-172.66) remained significant. Median time to recurrence (TTR) and overall survival (OS) was not reached after a median follow up of 30 months in patients undergoing successful CRC. Successful outcomes of IGBC are dependent on several factors. Diligent workup of suspicious thickening before simple cholecystectomy for gallstone disease and timely referral of IGBC to tertiary care are the keystones for good outcomes.

Relationship of Diet and Addiction with Gall Bladder Carcinoma-a Case-Control Study at a Tertiary Health Care Centre, India

Some dietary elements, tobacco use, have long been suspected as risk factors for gall bladder carcinoma. The objective of the study was to describe the dietary pattern of the patients with gall bladder carcinoma and to compare the dietary ingredients, and addiction between the cases and controls. Fifty-six gall bladder carcinoma cases and 56 matched controls were compared for diet and addiction patterns. Fried food, junk food, vanaspati, frozen fish, dried fish, red meat, kheer, milled mustard oil, puffed rice containing urea, chili powder, less water consumption, extra salt, tobacco exposure, betel leaf, and alcohol consumption were significantly related with gall bladder carcinoma. Green tea, sunflower oil, butter, ghee, fish intake more than twice weekly, sea fish, packaged milk, some fruits, and vegetables were found protective. Some dietary elements and addiction are related to gall bladder carcinoma, whereas some food items have a protective role.

Diagnostic performance of the gallbladder reporting and data system combined with color doppler flow imaging for gallbladder cancer in the Asian population

Purpose

Evaluating the performance of the Gallbladder Reporting and Data System (GB-RADS) combined with Color Doppler Flow Imaging (CDFI) for the diagnosis of gallbladder wall thickening disease in an Asian population.

Methods

In this study, the lesions were classified and the actual incidence rate of malignant tumors was calculated for each GB-RADS category, following the guidelines provided by GB-RADS. To evaluate the diagnostic performance of GB-RADS and GB-RADS combined with CDFI, we plotted Receiver Operator Characteristic (ROC) curves. The sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), and accuracy (AC) were also calculated. Inter-observer agreement (IRA) between the two observers was assessed using Kappa values.

Results

The incidence of malignancy risk for GB-RADS 2, 3, 4, and 5 was 9%, 12.5%, 72.2%, and 100%. The AUC for GB-RADS was 0.855 (95% CI: 0.800-0.900), with a sensitivity of 82.5%, a specificity of 84.6%, and an accuracy of 83.8%. The AUC of GB-RADS combined with CDFI was 0.965 (95% CI: 0.930-0.985), with a sensitivity of 96.2%, a specificity of 94.6%, and an accuracy of 95.2%. The AUC, sensitivity, specificity, and accuracy of GB-RADS combined with CDFI for diagnosing gallbladder malignancy were higher than those of GB-RADS alone, and the differences were statistically significant (all P < 0.05). The IRA was excellent between the two observers (Kappa = 0.870).

Conclusions

GB-RADS combined with CDFI demonstrated excellent diagnostic accuracy when it comes to distinguishing various diseases that caused gallbladder wall thickening in the Asian population, which has good clinical value and can improve the detection rate of malignant tumors in patients with gallbladder wall thickening.

Machine learning-based diagnostic model for preoperative differentiation between xanthogranulomatous cholecystitis and gallbladder carcinoma: a multicenter retrospective cohort study

Background

Xanthogranulomatous cholecystitis (XGC) and gallbladder carcinoma (GBC) share similar imaging and serological profiles, posing significant challenges in accurate preoperative diagnosis. This study aimed to identify reliable indicators and develop a predictive model to differentiate between XGC and GBC.

Methods

This retrospective study involved 436 patients from Zhejiang Provincial People's Hospital and The Affiliated Lihuili Hospital of Ningbo University. Comprehensive preoperative imaging, including ultrasound, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and blood tests, were analyzed. Machine learning (Random Forest method) was employed for variable selection, and a multivariate logistic regression analysis was used to construct a nomogram for predicting GBC. Statistical analyses were performed using SPSS and RStudio software.

Results

The study identified gender, Murphy's sign, absolute neutrophil count, glutamyl transpeptidase level, carcinoembryonic antigen level, and comprehensive imaging diagnosis as potential risk factors for GBC. A nomogram incorporating these factors demonstrated high predictive accuracy for GBC, outperforming individual or combined traditional diagnostic methods. External validation of the nomogram showed consistent results.

Conclusion

The study successfully developed a predictive nomogram for distinguishing GBC from XGC with high accuracy. This model, integrating multiple clinical and imaging indicators, offers a valuable tool for clinicians in making informed diagnostic decisions. The findings advocate for the use of comprehensive preoperative evaluations combined with advanced analytical tools to improve diagnostic accuracy in complex medical conditions.

E2F5 Targeted by Let-7d-5p Facilitates Cell Proliferation, Metastasis and Immune Escape in Gallbladder Cancer

BACKGROUND

Gallbladder cancer (GBC) remains a serious cause of cancer-related mortality across the globe. E2F5 has been identified to as a known oncogene in various cancers. However, the special functions of E2F5 have not been investigated in GBC.

AIMS

To explore the regulatory functions of E2F5 and its related molecular regulatory mechanism in GBC progression.

METHODS

The expression of genes were examined through qRT-PCR, western blot and IHC assay. The cell proliferation was assessed through CCK-8 and EDU assays. The cytotoxicity was tested through LDH assay. The percentage of CD8+ T cells and cell apoptosis were evaluated through flow cytometry. The binding ability was detected through luciferase reporter assay. The tumor growth was assessed through in vivo assays.

RESULTS

In this study, it was demonstrated that E2F5 expression was evaluated in GBC, and resulted into poor prognosis. Bioinformatics analysis revealed E2F5 as a target for let-7d-5p, which when overexpressed, suppressed the metastasis and proliferation of GBC through the downregulation of E2F5. It was discovered that E2F5 activates JAK2/STAT3 signaling which is suppressed by let-7d-5p, implicating this pathway as one of the effectors of the oncogenic effects of ESF5 in GBC. E2F5 had been confirmed to aggravate tumor growth in vivo.

CONCLUSION

E2F5 targeted by let-7d-5p facilitated cell proliferation, metastasis and immune escape in GBC through the JAK2/STAT3 pathway.

Risk stratification of gallbladder masses by machine learning-based ultrasound radiomics models: a prospective and multi-institutional study

OBJECTIVE

This study aimed to evaluate the diagnostic performance of machine learning (ML)-based ultrasound (US) radiomics models for risk stratification of gallbladder (GB) masses.

METHODS

We prospectively examined 640 pathologically confirmed GB masses obtained from 640 patients between August 2019 and October 2022 at four institutions. Radiomics features were extracted from grayscale US images and germane features were selected. Subsequently, 11 ML algorithms were separately used with the selected features to construct optimum US radiomics models for risk stratification of the GB masses. Furthermore, we compared the diagnostic performance of these models with the conventional US and contrast-enhanced US (CEUS) models.

RESULTS

The optimal XGBoost-based US radiomics model for discriminating neoplastic from non-neoplastic GB lesions showed higher diagnostic performance in terms of areas under the curves (AUCs) than the conventional US model (0.822-0.853 vs. 0.642-0.706, p < 0.05) and potentially decreased unnecessary cholecystectomy rate in a speculative comparison with performing cholecystectomy for lesions sized over 10 mm (2.7-13.8% vs. 53.6-64.9%, p < 0.05) in the validation and test sets. The AUCs of the XGBoost-based US radiomics model for discriminating carcinomas from benign GB lesions were higher than the conventional US model (0.904-0.979 vs. 0.706-0.766, p < 0.05). The XGBoost-US radiomics model performed better than the CEUS model in discriminating GB carcinomas (AUC: 0.995 vs. 0.902, p = 0.011).

CONCLUSIONS

The proposed ML-based US radiomics models possess the potential capacity for risk stratification of GB masses and may reduce the unnecessary cholecystectomy rate and use of CEUS.

CLINICAL RELEVANCE STATEMENT

The machine learning-based ultrasound radiomics models have potential for risk stratification of gallbladder masses and may potentially reduce unnecessary cholecystectomies.

KEY POINTS

• The XGBoost-based US radiomics models are useful for the risk stratification of GB masses. • The XGBoost-based US radiomics model is superior to the conventional US model for discriminating neoplastic from non-neoplastic GB lesions and may potentially decrease unnecessary cholecystectomy rate for lesions sized over 10 mm in comparison with the current consensus guideline. • The XGBoost-based US radiomics model could overmatch CEUS model in discriminating GB carcinomas from benign GB lesions.

Gallbladder Cancer in Simple Cholecystectomy Specimens-an Analysis of 8227 Gallbladders from an Endemic Region

Gallbladder cancers (GBCs) detected at pathological examination for suspected benign gallbladder disease are known as incidental GBCs. These post-cholecystectomy GBCs (PCGBCs) constitute a small fraction of all cholecystectomies. The proportion of these PCGBCs is unknown in endemic regions like North India. We planned to study the proportion and epidemiology of these PCGBCs in a high-volume center in North India. We reviewed the histopathology reports of gallbladder specimens for a 5-year period between 1 January 2014 and 31 December 2018, from a prospectively maintained pathology database. Patient demographics, place of referral (academic/non-academic center), and tumor characteristics were recorded. Descriptive statistics are used to demonstrate the distribution of various factors. Of the 8227 gallbladder specimens examined, cancer was found in 162 specimens. Thus, the proportions of GBC in these cases were 1.96%. The T stage of the tumor was T1a in 6 (3.8%), T1b in 35 (22.2%), T2 in 61 (38.8%), and T3 in 55 (35%). Liver bed margins were positive in 32/103 (31%). Of the evaluable 108 cystic duct margins, 16 (14.8%) were positive. Both margins were positive in 7/77 (9%) specimens and at least one margin was positive in 26/77 (33.7%) patients. This is the first study to demonstrate the high proportion of PCGBCs in high incidence area. This study provides a compelling reason to investigate this high PCGBC numbers. Routine histopathological evaluation of gallbladder should be done with diligence as this could alter the prognosis of a patient, especially in areas of high GBC incidence.

Identification of characteristic genes and construction of regulatory network in gallbladder carcinoma

BACKGROUND

Gallbladder carcinoma (GBC) is a highly malignant tumor with a poor overall prognosis. This study aimed to identify the characteristic microRNAs (miRNAs) of GBC and the competing endogenous RNA (ceRNA) regulatory mechanisms.

METHODS

The microarray data of GBC tissue samples and normal gallbladder (NGB) tissue samples from the Gene Expression Omnibus (GEO) database was downloaded. GBC-related differentially expressed miRNAs (DE-miRNAs) were identified by inter-group differential expression analysis and weighted gene co-expression network analysis (WGCNA). Machine learning algorithms were used to screen the characteristic miRNA based on the intersect between least absolute shrinkage and selection operator (LASSO) and Support vector machine-recursive feature elimination (SVM-RFE). Based on the differential expression analysis of GEO database, the ceRNA network of characteristic miRNA was predicted and constructed. The biological functions of the ceRNA network were revealed by carrying out the gene enrichment analysis was implemented. We further screened the key genes of ceRNA network and constructed a protein-protein interaction (PPI) network, and predicted and generated the transcription factors (TFs) network of signature miRNAs. The expression of characteristic miRNA in clinical samples was verified by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

A total of 131 GBC-related DE-miRNAs were obtained. The hsa-miR-4770 was defined as characteristic miRNA for GBC. The ceRNA network containing 211 mRNAs, one miRNA, two lncRNAs, and 48 circRNAs was created. Gene enrichment analysis suggested that the downstream genes were mainly involved in actin filament organization, cell-substrate adhesion, cell-matrix adhesion, reactive oxygen species metabolic process, glutamine metabolic process and extracellular matrix (ECM)-receptor interaction pathway. 10 key genes in the network were found to be most correlated with disease, and involved in cell cycle-related processes, p53, and extrinsic apoptotic signaling pathways. The qRT-PCR result demonstrated that hsa-miR-4770 is down-regulated in GBC, and the expression trend is consistent with the public database.

CONCLUSIONS

We identified hsa-miR-4770 as the characteristic miRNA for GBC. The ceRNA network of hsa-miR-4770 may play key roles in GBC. This study provided some basis for potential pathogenesis of GBC.

Metabolic dysfunction-associated gallstone disease: expecting more from critical care manifestations

About 20% of adults worldwide have gallstones which are solid conglomerates in the biliary tree made of cholesterol monohydrate crystals, mucin, calcium bilirubinate, and protein aggregates. About 20% of gallstone patients will definitively develop gallstone disease, a condition which consists of gallstone-related symptoms and/or complications requiring medical therapy, endoscopic procedures, and/or cholecystectomy. Gallstones represent one of the most prevalent digestive disorders in Western countries and patients with gallstone disease are one of the largest categories admitted to European hospitals. About 80% of gallstones in Western countries are made of cholesterol due to disturbed cholesterol homeostasis which involves the liver, the gallbladder and the intestine on a genetic background. The incidence of cholesterol gallstones is dramatically increasing in parallel with the global epidemic of insulin resistance, type 2 diabetes, expansion of visceral adiposity, obesity, and metabolic syndrome. In this context, gallstones can be largely considered a metabolic dysfunction-associated gallstone disease, a condition prone to specific and systemic preventive measures. In this review we discuss the key pathogenic and clinical aspects of gallstones, as the main clinical consequences of metabolic dysfunction-associated disease.

Drug resistance and new therapies in gallbladder cancer

Gallbladder cancer (GBC) is a highly aggressive malignancy, which poses significant challenges for timely diagnosis, resulting in a dismal prognosis. Chemotherapy serves as a primary treatment option in cases where surgery is not feasible. However, the emergence of chemoresistance poses a significant challenge to the effectiveness of chemotherapy, ultimately resulting in a poor prognosis. Despite extensive research on mechanisms of chemotherapeutic resistance in oncology, the underlying mechanisms of chemoresistance in GBC remain poorly understood. In this review, we present the findings from the last decade on the molecular mechanisms of chemotherapeutic resistance in GBC. We hope that these insights may provide novel therapeutic and experimental targets for further investigations into this lethal disease.

Practice patterns in diagnostics, staging, and management strategies of gallbladder cancer among Nordic tertiary centers

BACKGROUND AND OBJECTIVE

Gallbladder cancer (GBC) is a rare malignancy in the Nordic countries and no common Nordic treatment guidelines exist. This study aimed to characterize the current diagnostic and treatment strategies in the Nordic countries and disclose differences in these strategies.

METHODS

This was a survey study with a cross-sectional questionnaire of all 19 university hospitals providing curative-intent surgery for GBC in Sweden, Norway, Denmark, and Finland.

RESULTS

In all Nordic countries except Sweden, neoadjuvant/downstaging chemotherapy was used in GBC patients. In T1b and T2, majority of the centers (15-18/19) performed extended cholecystectomy. In T3, majority of the centers (13/19) performed cholecystectomy with resection of segments 4b and 5. In T4, majority of the centers (12-14/19) chose palliative/oncological care. The centers in Sweden extended lymphadenectomy beyond the hepatoduodenal ligament, whereas all other Nordic centers usually limited lymphadenectomy to the hepatoduodenal ligament. All Nordic centers except those in Norway used adjuvant chemotherapy routinely for GBC. There were no major differences between the Nordic centers in diagnostics and follow-up.

CONCLUSIONS

The surgical and oncological treatment strategies of GBC vary considerably between the Nordic centers and countries.

Aprepitant inhibits the development and metastasis of gallbladder cancer via ROS and MAPK activation

BACKGROUND

Aprepitant, as a neurokinin-1 receptor (NK-1R) antagonist, originally applied for curing chemotherapy-induced nausea and vomiting, has been reported to have significant antitumor effect on several malignant tumors. However, the effect of aprepitant on gallbladder cancer (GBC) is not clear yet. This study aimed to investigate the anti-tumor activity of aprepitant on GBC and the potential mechanisms.

METHODS

The NK-1R expression of gallbladder cancer cells were examined by immunofluorescence. MTT assay, wound healing and transwell migration assay were applied to detect the effect of aprepitant on cell proliferation, migration and invasion. Flow cytometry was used to detect the apoptosis rate. The effects of aprepitant on the expressions of cytokine were examined by real-time quantitative PCR and MAPK activation were detected via immunofluorescence and western blotting. Besides, xenograft model was established to investigate the effect of aprepitant in vivo.

RESULTS

Our results indicated that NK-1R was markedly expressed in gallbladder cancer cells and aprepitant effectively inhibited the proliferation, migration and invasion. Furthermore, the apoptosis, ROS and inflammation response were significantly boosted by aprepitant in GBC. Aprepitant induced NF-κB p65 nuclear translocationin and increased the expressions of p-P65, p-Akt, p-JNK, p-ERK and p-P38, as well as the mRNA levels of inflammatory cytokines IL-1β, IL-6 and TNF-α. Consistently, aprepitant suppressed the growth of GBC in xenograft mice model.

CONCLUSION

Our study demonstrated that aprepitant could inhibit the development of gallbladder cancer via inducing ROS and MAPK activation, which suggested that aprepitant may become a promising therapeutic drug against GBC.

Arsenic causing gallbladder cancer disease in Bihar

In recent times Gallbladder cancer (GBC) incidences increased many folds in India and are being reported from arsenic hotspots identified in Bihar. The study aims to establish association between arsenic exposure and gallbladder carcinogenesis. In the present study, n = 200 were control volunteers and n = 152 confirmed gallbladder cancer cases. The studied GBC patient's biological samples-gallbladder tissue, gallbladder stone, bile, blood and hair samples were collected for arsenic estimation. Moreover, n = 512 gallbladder cancer patients blood samples were also evaluated for the presence of arsenic to understand exposure level in the population. A significantly high arsenic concentration (p < 0.05) was detected in the blood samples with maximum concentration 389 µg/L in GBC cases in comparison to control. Similarly, in the gallbladder cancer patients, there was significantly high arsenic concentration observed in gallbladder tissue with highest concentration of 2166 µg/kg, in gallbladder stones 635 µg/kg, in bile samples 483 µg/L and in hair samples 6980 µg/kg respectively. Moreover, the n = 512 gallbladder cancer patient's blood samples study revealed very significant arsenic concentration in the population of Bihar with maximum arsenic concentration as 746 µg/L. The raised arsenic concentration in the gallbladder cancer patients' biological samples-gallbladder tissue, gallbladder stone, bile, blood, and hair samples was significantly very high in the arsenic exposed area. The study denotes that the gallbladder disease burden is very high in the arsenic exposed area of Bihar. The findings do provide a strong link between arsenic contamination and increased gallbladder carcinogenesis.

Threshold dose-response association between smoking pack-years and the risk of gallbladder cancer: A nationwide cohort study

BACKGROUND AND AIMS

The association between smoking and gallbladder cancer (GBC) risk is unclear. We investigated the association between smoking (including pack-years) and GBC risk. We also examined the combined effects of smoking and diabetes or prediabetes on GBC risk.

METHODS

This Korean nationwide cohort study included 9,520,629 adults without cancer who underwent national health screening in 2009 and were followed-up until 2018. Multivariable Cox proportional hazards models were used to determine risk estimates after adjusting for potential confounders.

RESULTS

During 78.4 million person-years (mean 8.2 ± 0.9 years) of follow-up, we identified 6066 patients with newly diagnosed GBC. Current and former smokers were associated with increased GBC risk (hazard ratio [HR], 95% confidence interval [CI]: 1.117, 1.029-1.212 and 1.105, 1.016-1.202, respectively). Smoking of 20 to <30 and ≥30 pack-years was independently associated with increased GBC risk compared with never smoking (HR, 95% CI; 1.241, 1.100-1.400 and 1.231, 1.107-1.370, respectively). However, smoking of <10 and 10 to <20 pack-years was not. This threshold dose-response association between smoking pack-years and GBC risk was observed regardless of the glycaemic status (all P < 0.01). Furthermore, smoking of ≥20 pack-years and hyperglycaemia had a synergistic effect on the GBC risk (all P < 0.01). Smokers with ≥20 pack-years with diabetes had the highest risk of GBC compared to never smokers with normoglycaemia (HR, 1.658; 95% CI, 1.437-1.914).

CONCLUSIONS

Smoking was associated with increased GBC risk with a threshold dose-response effect for smoking pack-years. The risk of GBC increases synergistically when smoking and hyperglycaemia coexist. More individualised cancer prevention education is required to reduce GBC risk.

Incidental gallbladder cancer: what is the prevalence and how do we perform cholecystectomy for presumably benign biliary disease?

OBJECTIVE

to determine the prevalence of incidental gallbladder cancer (IGBC) in cholecystectomies performed in a tertiary public hospital and to describe technical and epidemiological aspects of performing cholecystectomies for presumably benign disease.

METHOD

descriptive, retrospective observational study, based on analysis of medical records of patients undergoing cholecystectomy with preoperative hypothesis of benign disease between January 2018 and January 2022.

RESULTS

prevalence of gallbladder adenocarcinoma in our sample was 0.16%, similar to data in the literature. Technical aspects during cholecystectomy were also described with a frequency similar to that found in the literature.

CONCLUSION

despite a rare disease, IGBC is relevant in the routine of the General Surgeon. Its diagnosis, staging and treatment directly affect the prognosis. Technical aspects during cholecystectomy are not always remembered by surgeons and can interfere with the prognosis and subsequent treatment of the patient.

Development and validation of prognostic nomograms in patients with gallbladder mucinous adenocarcinoma: A population-based study

Background

Gallbladder mucinous adenocarcinoma (GBMAC) is an uncommon malignant gallbladder tumor. There are few studies on its prognosis, with the majority consisting of small series or individual cases. We sought to develop and validate nomograms for predicting overall survival (OS) and cancer-specific survival (CSS) in GBMAC patients.

Methods

The clinicopathological data of GBMAC patients from 1975 to 2019 was extracted from the Surveillance, Epidemiology, and End Results (SEER) database, and all patients were randomly divided into a training cohort (70%) and a validation cohort (30%). Using multivariate Cox regression analyses based on Akaike information criterion (AIC), prognostic and important variables for GBMAC were determined. On the basis of these factors, nomograms were developed to predict the 1-, 3-, and 5-year OS and CSS rates of patients with GBMAC. Multiple parameters, including the area under the subject operating characteristic curve (AUC), the calibration plots, and the decision curve analysis (DCA), were then used to evaluate the accuracy of nomograms.

Results

Following exclusion, a total of 707 GBMAC patients were enrolled, and the training cohort (490, 70%) and validation cohort (217, 30%) were randomly assigned. Grade, surgery, radiation, and SEER stage were predictive factors for patients with GBMAC, as indicated by univariate and multivariate Cox regression analyses based on AIC. We created nomograms for predicting OS and CSS in GBMAC using the four factors. The calibration curves and area under the curves (AUCs) indicated that our nomograms have a moderate degree of predictive accuracy and capability. The results of the DCA revealed that the nomogram has a high predictive value.

Conclusion

We established the first nomograms for predicting 1-, 3-, and 5-year OS and CSS in GBMAC patients, thereby contributing to the prognostication of patients and clinical management.

A clinicoepidemiological and management profile of metastatic carcinoma gallbladder in the northeast part of Indian patients in a tertiary care center

Introduction

Metastatic gallbladder cancer (GBC) is a highly fatal malignancy and it is difficult to treat the advanced stage of GBC. In India, northern and northeastern states are the worst affected by this disease. We, hereby, report the clinicoepidemiological and management profile of 242 patients of metastatic carcinoma of GB.

Materials and Methods

In this study, a total of 242 cases of metastatic GBC (detected either on the first presentation or during follow-up) were managed at the Department of Medical Oncology tertiary care oncology center in the northeast part of India from May 2018 to September 2019. On presentation, all patients were subjected to detailed history and clinical examination, followed by requisite investigations and were treated as per the existent guidelines.

Results

One-hundred and forty-two patients were female, while 100 patients were male out of 242 patients. Female patients with metastatic GBC presented with the mean age of 54, while for males, 51.4 years. The most common presentation was pain abdomen (81.8%), while the second most common was anorexia (77.2%), followed by weight loss (62.8%) and mass per abdomen (60.7%). The most common site of metastasis recorded in our study was the liver (79.7%), followed by nonregional abdominal lymph node (69.4%) and ascites (64.4%). Out of the 242 patients, 24 patients had presented in poor Eastern Cooperative Oncology Group Performance Status (≥3) hence were deemed unfit for any oncological interventions. About 136 (56.1%) patients had presented with features of obstructive jaundice, however only 108 patients were subjected to biliary drainage procedure. After the biliary drainage procedures, only one-third (38 out of 136; 35.1%) of patients were finally able to receive chemotherapy.

Conclusion

In India, unfortunately, many patients present very late during the course of their illness. There is a need for the development of effective chemotherapy or targeted therapy and also there is an unmet need for patients' education. There has been an increase in the incidence of this malignancy, especially in the Northeast part of India; hence, it is the need of the hour to study various epidemiological and causative factors of the disease. Furthermore, the development of therapies for the effective management of this malignancy is really required.

Ubiquitin-specific protease 3 facilitates cell proliferation by deubiquitinating pyruvate kinase L/R in gallbladder cancer

Ubiquitin-specific protease 3 (USP3), a kind of cysteine protease, is a crucial family member of deubiquitinating enzymes. USP3 is aberrantly expressed in several tumors, which may contribute to cancer progression. However, the role of USP3 in gallbladder cancer (GBC) is still unknown. In the current study, we detected the expression of USP3 in GBC tissues, measured its contribution to the cell proliferation in GBC progression, and further studied the underlying mechanism of USP3 in GBC through pyruvate kinase L/R (PKLR; a kind of glycolytic enzyme). We found that the expression of USP3 in GBC tissues were higher than that of adjacent tissues, and the protein levels of USP3 and PKLR were positively correlated. Additionally, overexpressed USP3 significantly promoted cell proliferation in vitro and tumor growth in vivo, while the silencing of USP3 inhibited proliferation and tumor growth. Glycolysis in GBC cells ws promoted by the USP3 overexpression and inhibited bye USP3 downregulation. Moreover, the loss of USP3 promoted the ubiquitination and weakened the stability of PKLR. Results of the rescue assay confirmed that PKLR knockdown suppressed USP3-induced oncogenic activity in USP3 overexpressed GBC cells. These findings imply that USP3 is an essential positive regulator in GBC progression, and USP3-PKLR plays a vital role in the progression and metabolism of GBC.

Single-cell RNA sequencing highlights the functional role of human endogenous retroviruses in gallbladder cancer

Background

Gallbladder cancer (GBC), the most common malignancy of the biliary tract, shows late diagnosis and low survival rate and requires continued search for new diagnostic biomarkers and therapeutic targets. Human endogenous retroviruses (HERVs) are specifically prone to be reactivated in diverse cancers and are implicated in cancer progression and immunotherapy.

Methods

Single-cell RNA sequencing was performed on tumor tissues and paired adjacent tissues from 4 GBC patients. Dual-luciferase reporter assay was applied to measure enhancer activity of HERV sequences.

Findings

We dissected the cellular diversity and described the HERV transcriptomic landscape for GBC. We found that HERVs were transcribed in a cell type-specific manner and different HERV families were associated with diverse biological effects. HERVs could function as enhancers, presumably causing altered expression of neighboring genes. The transcription level of HERVH was gradually elevated with the malignant transformation of epithelial cells, suggesting HERVH may be a potential early diagnostic biomarker of GBC. HHLA2, a newly emerging immune checkpoint, was derived by HERVH, exhibited an expressional correlation with HERVH, and was identified as a promising target for immunotherapy.

Interpretation

Exploring the transcriptional landscape and potential functional impact of HERVs highlights the important role of HERVs in GBC and provides a fresh perspective on managing GBC.

Funding

This study was supported by the National Natural Science Foundation of China (31970176, 81972256) and the research grants from the Innovation Capacity Building Project of Jiangsu province (BM2020019).

Associations between external beam radiotherapy and overall survival in patients with gallbladder cancer: A population-based study

Background

There is a lack of studies regarding radiotherapy (RT) in patients with gallbladder cancer (GBC) on the survival benefit after surgery and nonsurgical treatment. Therefore, this study evaluated the impact of external beam RT on the overall survival (OS) of patients with GBC in a real-world setting.

Methods

Patients with GBC enrolled from the Surveillance, Epidemiology, and End Results (SEER) database were examined through Kaplan-Meier survival curves and multivariable Cox regression analyses.

Results

A total of 7,866 patients with GBC were screened for the current analysis, of whom 2,130 (27.1%) did not undergo RT or surgery, 209 (2.7%) underwent RT, 4,511 (57.3%) underwent surgery, and 1,016 (12.9%) underwent both RT and surgery. The median OS times were 4 months, 8 months, 16 months, and 22 months (p < 0.0001). OS was significantly different between adjuvant RT (p = 0.0002) and palliative RT (p < 0.0001). Multifactorial analysis (controlling for age, sex, year of diagnosis, marital status, race, grade, and stage) showed that both adjuvant RT (surgery and adjuvant RT vs. surgery alone; HR, 0.75; 95% CI, 0.69-0.82, p < 0.001) and palliative RT (RT alone vs. no treatment; HR, 0.80; 95% CI, 0.69-0.92, p = 0.003) had a significant impact on patient OS. The results remained stable following sensitivity analyses.

Conclusion

The study results indicate that adjuvant and palliative radiation treatment was associated with a survival benefit. GBC patients can derive a survival benefit from external beam RT.

A Review of the Etiology and Epidemiology of Gallbladder Cancer: What You Need to Know

Gallbladder cancer (GBC) is the sixth most prevalent cancer of the gastrointestinal system but the most prevalent cancer of the biliary tract. This tumor is a highly fatal condition. The importance of early diagnosis cannot be overstated because GBC develops quietly with late detection. Several genetic and environmental variables have been associated with the onset of GBC. Cholelithiasis and chronic inflammation from the biliary tract and parasite infections are prime examples of environmental factors that significantly influence the development of GBC. Abnormal pancreaticobiliary duct junction and biliary cysts are examples of congenital causes. In the past decade, new imaging technologies and a more radical and aggressive surgical approach have improved patient outcomes and aided prolonged survival for GBC patients. This review article focuses on the epidemiology of GBC, its risk factors, and clinical characteristics.

Inhibition of AMPK/PFKFB3 mediated glycolysis synergizes with penfluridol to suppress gallbladder cancer growth

BACKGROUND

Penfluridol (PF) is an FDA-approved antipsychotic drug that has recently been shown to have anticancer activity. However, the anticancer effects and underlying mechanisms of PF are not well-established in gallbladder cancer (GBC).

METHODS

The anticancer efficacy of PF on GBC was investigated via a series of cell functions experiments, including cell viability, colony formation, apoptosis assays, and so on. The corresponding signaling changes after PF treatment were explored by western blotting. Then, nude mice were utilized to study and test the anticancer activity of PF in vivo. Besides, glucose consumption and lactic production assays were used to detect the glycolysis alteration.

RESULTS

In this study, we discovered that PF greatly inhibited the proliferation and invasion ability of GBC cells (GBCs). The glucose consumption and lactic generation ability of GBCs were dramatically elevated following PF treatment. Additionally, we discovered that inhibiting glycolysis could improve PF's anticancer efficacy. Further studies established that the activation of the AMPK/PFKFB3 signaling pathway medicated glycolysis after PF treatment. We proved mechanistically that inhibition of AMPK/PFKFB3 singling pathway mediated glycolysis was a potential synergetic strategy to improve the anticancer efficacy of PF on GBC.

CONCLUSIONS

By inhibiting AMPK, the anticancer effects of PF on GBCs were amplified. As a result, our investigations shed new light on the possibility of repurposing PF as an anticancer drug for GBC, and AMPK inhibition in combination with PF may represent a novel therapeutic strategy for GBC. Video abstract.

Postoperative recurrent patterns of gallbladder cancer: possible implications for adjuvant therapy

BACKGROUND

Gallbladder cancer (GBC) is an uncommon malignancy with high recurrent rate and poor prognosis. This study investigates the recurrent patterns of postoperative GBC, with the aim to guide the adjuvant treatments, including the radiotherapy.

METHODS

Retrospectively analyzed the 109 GBC patients who underwent surgery in our institution from January 2013 to 2018. Clinical follow-up revealed 54 recurrent cases, of which 40 had detailed locations of recurrence. The sites of recurrence were recorded and divided into the tumor bed, corresponding lymphatic drainage area, intrahepatic recurrence, and the other distant metastasis.

RESULTS

The median follow-up time is 34 months (IQR: 11-64). The median disease-free survival (DFS) and overall survival (OS) were 48.8 months and 53.7 months, respectively. Through univariate analysis, risk factors for DFS and OS include tumor markers (CA199 and CEA), hepatic invasion, perineural invasion, lymphovascular invasion, TNM staging and tumor differentiation. Through multivariate analysis, risk factors for DFS include hepatic invasion and TNM staging, and for OS is TNM staging only. Of the 40 cases with specific recurrent sites, 29 patients (29/40, 72.5%) had recurrence in the potential target volume of postoperative radiotherapy (PORT), which include tumor bed and corresponding lymphatic drainage area. The common recurrent lymph node groups included abdominal para-aortic lymph node (No.16, 15/29), hepatoduodenal ligament lymph node (No.12, 8/29), retro-pancreatic head lymph node (No.13, 7/29) and celiac axis lymph node (No.9, 4/29). Twenty cases with recurrences inside the potential PORT target volume were accompanied by distant metastasis. Another 11 cases had distant metastasis alone, so totally 31 cases developed distant metastasis (31/40, 77.5%), including 18 cases with hepatic metastasis.

CONCLUSION

The recurrence and metastasis rates are high in GBC and adjuvant therapy is needed. Up to 75% of the recurrent cases occurred in the potential target volume of postoperative radiotherapy, suggesting that postoperative radiotherapy has the possible value of improving local-regional control. The potential target volume of radiotherapy should include the tumor bed, No.8, No.9, No.11, No.12, No.13, No.14, No. 16a2, No. 16b1 lymph node groups.

METTL3-mediated N6-methyladenosine modification of DUSP5 mRNA promotes gallbladder-cancer progression

N⁶-methyladenosine (m⁶A) RNA methylation and its associated methyltransferase METTL3 play an important role in tumorigenesis of a series of tumors. However, dysregulation of METTL3 in gallbladder cancer (GBC) remains obscure. Here, we showed that upregulated METTL3 level predicted poor prognosis and correlated with increased lymphatic metastasis and high TNM stage. Functionally, we found that METTL3 could promote cell proliferation, invasion, and migration of GBC-SD and NOZ cells. Mechanistically, we revealed the METTL3-mediated m⁶A-modification profile in GBC cells and identified DUSP5 as the downstream gene of METTL3. METTL3 promoted the degradation of DUSP5 mRNA in a YTHDF2-dependent manner. Rescue assays showed that downregulation of DUSP5 could attenuate the knockdown METTL3-mediated inhibition of cell proliferation, invasion, and migration of GBC-SD and NOZ cells. Thus, our finding shows that elevated METTL3 expression contributes to tumor aggression in GBC, suggesting that METTL3 is a possible prognostic predictor and therapeutic target against GBC.

Reproductive factors and gall-bladder cancer, and the effect of common genetic variants on these associations: a case-control study in India

BACKGROUND

In India, as elsewhere, the incidence of gall-bladder cancer (GBC) is substantially higher in women than in men. Yet, the relevance of reproductive factors to GBC remains poorly understood.

METHODS

We used logistic regression adjusted for age, education and area to examine associations between reproductive factors and GBC risk, using 790 cases of histologically confirmed GBC and group-matched 1726 visitor controls. We tested the interaction of these associations by genetic variants known to increase the risk of GBC.

RESULTS

Parity was strongly positively associated with GBC risk: each additional pregnancy was associated with an ∼25% higher risk {odds ratio [OR] 1.26 [95% confidence interval (95% CI) 1.17-1.37]}. After controlling for parity, GBC risk was weakly positively associated with later age of menarche [postmenopausal women, OR 1.11 (95% CI 1.00-1.22) per year], earlier menopause [OR 1.03 (95% CI 1.00-1.06) per year] and shorter reproductive lifespan [OR 1.04 (95% CI 1.01-1.07) per year], but there was little evidence of an association with breastfeeding duration or years since last pregnancy. Risk alleles of single-nucleotide polymorphisms in the ABCB4 and ABCB1 genetic regions had a multiplicative effect on the association with parity, but did not interact with other reproductive factors.

CONCLUSIONS

We observed higher GBC risk with higher parity and shorter reproductive lifespan, suggesting an important role for reproductive and hormonal factors.

A case of undifferentiated carcinoma of the gallbladder with severe inflammation and difficult preoperative chemotherapy

Undifferentiated carcinoma (UC) is relatively rare among gallbladder cancers, and the prognosis is poor compared to gallbladder adenocarcinoma. We report a 64-year-old man with gallbladder UC who underwent radical surgery and achieved long-term survival. He presented with a chief complaint of abdominal distension and loss of appetite. An abdominal computed tomography (CT) scan revealed a gallbladder tumor with a major axis of 120 mm that appeared to directly infiltrate the hepatic bed. No major vascular infiltration was noted, but the left and right intrahepatic bile ducts were dilated. On admission, the serum CRP level was 16.5 mg/dL; cholangitis and cholecystitis were suspected. He was hospitalized, treated with antibiotics, and underwent bile duct drainage; however, inflammation recurred and chemotherapy was not possible. Thus, three right liver areas, the caudate lobe, and the gallbladder were extirpated. Histopathologic examination showed a 130 × 90 mm tumor with extensive infiltration, hemorrhage, and necrosis in the liver. In the area occupied by the tumor, multinucleated cell proliferation, and polygonal and spindle-shaped tumor cells were noted. Based on the above findings, a diagnosis of UC was established. Postoperatively, gemcitabine and cisplatin were continued as adjuvant chemotherapy. No tumor recurrence has been detected after 24 months of follow-up care.

Bortezomib-Encapsulated Dual Responsive Copolymeric Nanoparticles for Gallbladder Cancer Targeted Therapy

Gallbladder cancer (GBC) is a rare but the most malignant type of biliary tract tumor. It is usually diagnosed at an advanced stage and conventional treatments are unsatisfactory. As a proteasome inhibitor, bortezomib (BTZ) exhibits excellent antitumor ability in GBC. However, the long-term treatment efficacy is limited by its resistance, poor stability, and high toxicity. Herein, BTZ-encapsulated pH-responsive copolymeric nanoparticles with estrone (ES-NP_{(BTZ; Ce6)} ) for GBC-specific targeted therapy is reported. Due to the high estrogen receptor expression in GBC, ES-NP_{(BTZ; Ce6)} can rapidly enter the cells and accumulate near the nucleus via ES-mediated endocytosis. Under acidic tumor microenvironment (TME) and 808 nm laser irradiation, BTZ is released and ROS is generated by Ce6 to destroy the "bounce-back" response pathway proteins, such as DDI2 and p97, which can effectively inhibit proteasomes and increase apoptosis. Compared to the traditional treatment using BTZ monotherapy, ES-NP_{(BTZ; Ce6)} can significantly impede disease progression at lower BTZ concentrations and improve its resistance. Moreover, ES-NP_{(BTZ; Ce6)} demonstrates similar antitumor abilities in patient-derived xenograft animal models and five other types of solid tumor cells, revealing its potential as a broad-spectrum antitumor formulation.

Radical surgery for de novo gallbladder carcinoma-Single-center analysis of prognostic factors and survival outcomes from an endemic region

BACKGROUND AND OBJECTIVE

Gallbladder cancer (GBC) is an aggressive malignancy where curative resection is possible in few and survival is poor. There are limited data on outcomes in patients with de novo GBC from endemic regions undergoing surgery for curative intent. We report survival outcomes in this group of patients from a region with high incidence of disease.

METHODS

We reviewed the records of all GBC patients (2014-2018) and included those who underwent radical cholecystectomy (RC) for de novo GBC. Univariable and multivariable analyses were performed to identify factors influencing recurrence and survival.

RESULTS

A total of 649 patients with GBC were evaluated for surgery and curative intent surgery was attempted in 246 (38%) patients. Of these 246 patients, RC was performed in 115 patients, with histologically confirmed de novo GBC. Locally advanced disease (≥stage IIIB) was present in 52 (45.2%) patients. Median time to recurrence and overall survival (OS) were 31 and 36 months, respectively. Lymph node positivity (p = 0.005) and grade significantly influenced OS on multivariable analysis.

CONCLUSION

Satisfactory survival outcomes are possible after RC for de novo GBC. Extended resections performed in high volume centers combined with appropriate adjuvant treatment can offer significant survival benefits, with acceptable morbidity and mortality rates.

Role of Dual-Energy Computed Tomography in Gallbladder Disease: A Review

Gallbladder diseases are common and include a spectrum ranging from benign to cancer. Imaging plays an integral role in the diagnosis and in guiding appropriate management. While most patients with gallstone (GS) diseases can be evaluated with ultrasound, those with complicated GS disease, suspicion of cancer, or staging of cancer need additional cross-sectional imaging. Computed tomography (CT) is widely available and is often the imaging test of choice following an equivocal ultrasound or negative ultrasound in patients with unexplained symptoms. Conventional CT has limited sensitivity in detecting GS or common bile duct stones. In other scenarios, including diagnosis of acute cholecystitis (AC) and characterization of gallbladder wall thickening, an increase in accuracy using novel techniques is desirable. Dual-energy computed tomography (DECT) is increasingly incorporated into clinical practice. DECT has shown promising results in the detection of cholesterol stones that otherwise go unnoticed on conventional CT. However, its role beyond GS disease has largely been unexplored. In this review, we discuss the available literature on the DECT in biliary diseases and discuss the potential applications of this technique.

HER2 Positivity Is Affected by the Papillary Structure and Has a Bidirectional Prognostic Value for Gallbladder Carcinoma

Gallbladder carcinoma (GBC) is responsible for 80%–95% of biliary tract malignancies and has a dismal prognosis. Human epidermal growth factor receptor 2 (HER2) is a promising therapeutic target of GBC. Through immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) methods, HER2 expression and gene amplification were identified on high-output tissue microarrays (TMAs) developed in 306 GBC cases to investigate its relationship with GBC and clinicopathological characteristics. Adenocarcinomas accounted for 223 (72.9%) of the cases, with 62 (27.8%) being papillary adenocarcinoma or having partial papillary structure. HER2 positivity was studied in 16.1% (36/223) of patients with adenocarcinoma and 41.9% (26/62) in adenocarcinoma with papillary structures. For 143 radically resected primary GBC cases with 24 HER2-positive tumors, survival data were valid; the median survival time was not reached, and the 5-year survival rate was 52.9%. All patients in stages 0–I survived, and the results of the HER2-positive group and the stage II HER2-negative group were similar (p = 0.354). However, in stage III, the mortality rate in the HER2-positive group was reduced (p = 0.005) and that in stage IV was higher (p = 0.005). In conclusion, HER2 positivity was significantly higher in patients with papillary GBC. The predictive value of HER2 varies by clinical stage, with no prediction in the early stages, better in stage III, and worse in stage IV.

Prospective Randomized Controlled Trial Comparing Adjuvant Chemotherapy vs. No Chemotherapy for Patients with Carcinoma of Gallbladder Undergoing Curative Resection

BACKGROUND

Gallbladder carcinoma (GBC) has a dismal prognosis even after curative resection. The objective of the study was to evaluate the effect of adjuvant chemotherapy in patients with GBC undergoing curative resection in a randomized control trial (RCT).

METHODS

A single-center open-labeled prospective RCT was done from January 2012 to June 2018. R0 curative resected GBC patients were randomized in 1:1 to either surveillance alone (control group) or adjuvant chemotherapy (gemcitabine and cisplatin (GemCis group)) for 6 cycles. The primary outcome was disease-free survival (DFS), and the secondary outcomes were overall survival (OS) and toxicity profile.

RESULTS

On the evaluation of 362 patients with GBC, 50 patients were enrolled in each control or GemCis group. Per protocol (PP), it comprised 96 patients. The demographic and clinical profile was similar between the two groups except in the lower nodal stage where patients were higher in the control group (p = 0.01). Recurrences were similar between groups (control 44% vs GemCis 56%; p = 0.23). On the intention to treat (ITT), analyses of median DFS (not reached vs. 24 months, p = 0.14) and OS (not reached vs. 31 months, p = 0.10) were similar between groups. On PP, analyses of median DFS (not reached vs. 24 months, p = 0.16) and OS (not reached vs. 31 months, p = 0.09) were similar between groups. The common toxicity profile was hematological followed by gastrointestinal symptoms.

CONCLUSIONS

Adjuvant GemCis therapy for 6 cycles does not improve DFS or OS than R0 surgery alone patients with GBC.

TRIAL REGISTRATION

NCT02778308 ( https://www.clinicaltrials.gov ).

A Propensity Score Analysis of Chemotherapy Use in Patients With Resectable Gallbladder Cancer

IMPORTANCE

Gallbladder cancer is uncommon but highly fatal. Surgery remains the only potentially curative treatment for localized or locoregionally advanced gallbladder cancer. The rate of use of neoadjuvant and adjuvant chemotherapy in resectable gallbladder cancer is unknown.

OBJECTIVE

To assess factors associated with the use of neoadjuvant and adjuvant chemotherapy in patients with resectable gallbladder cancer and survival outcomes.

DESIGN, SETTING, AND PARTICIPANTS

The National Cancer Database was used to identify 6391 adults who underwent definitive surgical resection for gallbladder cancers between January 1, 2004, and January 1, 2016. Data analysis was performed from January 15 to February 15, 2020. Patients with localized or locoregionally advanced gallbladder cancers (ie, categories cTx-cT4, cN0-2, and cM0) were categorized as receiving neoadjuvant chemotherapy, adjuvant chemotherapy, or surgery alone. Categorical variables were compared using the χ2 test, with 1:3 nearest-neighbor propensity score matching based on neoadjuvant chemotherapy. Survival outcomes between groups were compared using Kaplan-Meier and Cox proportional hazards regression analyses.

MAIN OUTCOMES AND MEASURES

The use and survival outcomes of adjuvant and neoadjuvant chemotherapy.

RESULTS

Of 6391 patients who underwent definitive surgery for gallbladder cancer, 4559 were women (71.3%); median age was 68 (IQR, 59-77) years. A total of 3145 patients (49.2%) received adjuvant chemotherapy, 3145 patients (49.2%) underwent surgery without chemotherapy, and 101 patients (1.6%) received neoadjuvant chemotherapy. Neoadjuvant chemotherapy use was associated with treatment at an academic facility (61 patients [60%] vs 38 patients [38%] treated in a nonacademic facility; P < .001) and in those with private insurance (65 patients [65%] vs 11 patients [11%] with Medicaid insurance; P < .001). Surgery alone was frequently used in older patients (median age, 72 [IQR, 63-81] years vs 59 [IQR, 52-66] years in patients with neoadjuvant chemotherapy; P < .001), those with Medicare insurance (1925 patients [57%] vs 1438 patients [43%] with adjuvant chemotherapy; P < .001), and patients with a higher comorbidity index score (326 patients [62%] vs 197 patients [38%] with adjuvant chemotherapy; P < .001). Adjuvant or neoadjuvant chemotherapy was used more frequently than surgery in patients with node-positive cancer (1482 [67.2%] vs 53 [65.4%] vs 912 [49.7%]). On propensity score matching analysis, adjuvant chemotherapy was associated with longer survival than surgery alone (22 vs 18 months, hazard ratio [HR], 0.78; 95% CI, 0.63-0.96); survival with neoadjuvant chemotherapy was not statistically significant compared with surgery alone and adjuvant chemotherapy groups (27 months, HR, 0.78; 95% CI, 0.58-1.04). However, in patients with node-positive gallbladder cancer, neoadjuvant therapy was associated with longer median overall survival (30 months [95% CI, 24-36 months] vs 14 months [95% CI, 11-17] in patients with surgery alone; P = .002).

CONCLUSIONS AND RELEVANCE

In this cohort study, use of adjuvant and neoadjuvant chemotherapy was low in patients with surgically resected gallbladder cancers. Chemotherapy was used more frequently than surgery in lymph node-positive disease compared with lymph node-negative disease. Adjuvant chemotherapy was associated with a survival advantage in resectable gallbladder cancer, and neoadjuvant chemotherapy was associated with increased survival in node-positive gallbladder cancers. These findings suggest that adjuvant chemotherapy and neoadjuvant chemotherapy should be considered in treatment of gallbladder cancer.

Locally advanced gallbladder cancer treated with effective chemotherapy and subsequent curative resection: a case report

Background

Surgical resection of gallbladder cancer with negative margins is the only potentially curative therapy. Most patients with gallbladder cancer are diagnosed in an advanced stage and, despite the availability of several chemotherapies, the prognosis remains dismal. We report a case of locally advanced gallbladder cancer that was successfully treated with effective cisplatin plus gemcitabine, followed by curative resection.

Case presentation

A 55-year-old Japanese female was hospitalized with right hypochondrial pain. Enhanced computed tomography revealed a 49 × 47 mm mass at the neck of the gallbladder, with suspected invasion of the liver and right hepatic artery. Endoscopic retrograde cholangiopancreatography demonstrated displacement of the upper bile duct. Intraductal ultrasonography showed irregular wall thickening and disappearance of the wall structure in bile ducts from the B4 branch to distal B2 and B3. Percutaneous transhepatic biliary biopsy revealed a poorly differentiated carcinoma. The patient was diagnosed with unresectable gallbladder cancer (T4N0M0 stage IVA). Cisplatin plus gemcitabine chemotherapy was initiated. After six courses of chemotherapy, enhanced computed tomography showed that the mass in the neck of the gallbladder had shrunk to 30 mm, Endoscopic retrograde cholangiopancreatography showed improvement of the hilar duct stenosis. A biopsy of the bile duct mucosa showed no malignant cells in the branch of the left and right hepatic ducts, the left hepatic duct, or the intrapancreatic ducts. The patient underwent conversion surgery with right and segment 4a liver resection, extrahepatic duct resection, and cholangiojejunostomy. The histopathologic diagnosis showed that the tumor cells had shrunk to 2 × 1 mm, and that R0 resection of the T2aN0M0 stage IIA tumor was successful.

Conclusion

Although conversion surgery for gallbladder cancer is rarely possible, curative resection may offer a better prognosis, and it is important to regularly pursue possibilities for surgical resection even during chemotherapy.

Association and functional significance of genetic variants present in regulatory elements of SERPINB5 gene in gallbladder cancer

SERPINB5 is a mammary serine protease inhibitor, which is involved in various cellular functions. The aberrant expression of SERPINB5 is reported in many cancers along with GBC but limited information is available about its role in genetic predisposition for GBC. We carried out case-control study in 206 cases and 219 controls. Promoter SNPs were genotyped by Sanger's sequencing. In-silico promoter analysis and luciferase reporter assay were done to elucidate the role of promoter variants in regulation of SERPINB5 expression. Out of four SNPs, three SERPINB5 promoter variants showed association with GBC in different models. The 'C' allele of variant rs17071138 was found to be significantly associated with GBC (p = 0.017). The 'T' allele of rs3744940 significantly increased the risk for GBC in dominant (p = 0.035) and additive models (p = 0.005). Also, rs3744941 'T' allele increased the risk for GBC by dominant (p = 0.042) as well as additive models (p = 0.016). In-silico promoter analysis and luciferase reporter assay revealed the probable regulatory role of the SERPINB5 promoter variant rs17071138 on the expression. Overall, our study reveals the genetic association of SERPINB5 promoter variants with GBC and possible role of rs17071138 in the regulation of expression.

Axillary nodal metastasis of operated gallbladder carcinoma: remote site of aggression-a case report

BACKGROUND

Gallbladder cancer is a very aggressive type of biliary tract cancer. The only curative treatment is complete surgical excision of the tumour. However, even after surgery, there is still a risk of recurrence of the cancer.

CASE PRESENTATION

A 63-year-old gentleman presented with the complaint of a non-healing ulcer at upper abdomen for the last 1 month. He had undergone a laparoscopic cholecystectomy at a private centre 4 months ago. Investigations confirmed the diagnosis of epigastric port site metastasis from a primary from gall bladder adenocarcinoma. After undergoing completion radical cholecystectomy with wide local excision of the epigastric ulcer, he received 6 cycles of concurrent chemoradiotherapy. Eighteen months later, he presented to us with bilateral axillary swellings. Investigations confirmed isolated bilateral axillary metastasis and the patient underwent a bilateral axillary lymphadenectomy (Level 3). However, PET scan after 6 months showed widespread metastasis and the patient succumbed to the illness 1 month later.

CONCLUSION

Axillary metastasis probably occurs due to the presence of microscopic systemic metastasis at the time of development of port site metastasis. An R0 resection of the malignancy is the only viable option for effective therapy. The present case highlights the rare involvement of isolated bilateral axillary lymph nodes as a distant metastatic site with no evidence of disease in the locoregional site. However, the prognosis after metastasis remains dismal despite multiple treatment modalities.

OLFM4 depletion sensitizes gallbladder cancer cells to cisplatin through the ARL6IP1/caspase-3 axis

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OLFM4 is involved in development of gallbladder cancer.

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Depletion of OLFM4 sensitizes gallbladder cancer cells to cisplatin by regulating apoptosis.

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Low expression of OLFM4 in GBC patients indicates longer survival.

Background

Gallbladder cancer (GBC) is a highly lethal malignancy that carries an extremely poor prognosis due to its chemoresistant nature. Cisplatin (CDDP) is a first-line chemotherapeutic for GBC; however, patients experienced no benefit when treated with CDDP alone. The underlying mechanisms of CDDP resistance in GBC remain largely unknown.

Methods

Agilent mRNA microarray analysis was performed between paired GBC and paracarcinoma to explore differentially expressed genes that might underlie drug resistance. Gene Set Enrichment Analysis (GSEA) was employed to identify key genes mediating CDDP resistance in GBC, and immunohistochemistry was performed to validate protein expression and test correlations with clinicopathological features. In vitro and in vivo functional assays were performed to investigate the proteins’ roles in CDDP resistance.

Results

Olfactomedin 4 (OLFM4) was differentially expressed between GBC and paracarcinoma and had the highest rank metric score in the GSEA. OLFM4 expression was increasingly upregulated from chronic cholecystitis to GBC in clinical tissue samples, and OLFM4 depletion decreased GBC cell proliferation and invasion. Interestingly, downregulation of OLFM4 reduced ARL6IP1 (antiapoptotic factor) expression and sensitized GBC cells to CDDP both in vitro and in vivo. The evidence indicated that CDDP could significantly increase Bax and Bad expression and activate caspase-3 cascade in OLFM4-depleted GBC cells through ARL6IP1. Clinically, lower OLFM4 expression was associated with good prognosis of GBC patients.

Conclusions

Our results suggest that OLFM4 is an essential gene that contributes to GBC chemoresistance and could serve as a prognostic biomarker for GBC. Importantly, OLFM4 could be a potential chemotherapeutic target.