Laparoscopic vs open radical resection in management of gallbladder carcinoma: A systematic review and meta-analysis.

BACKGROUND: Radical resection offers the only hope for the long-term survival of patients with gallbladder carcinoma (GBC) above the T1b stage. However, whether it should be performed under laparoscopy for GBC is still controversial. AIM: To compare laparoscopic radical resection (LRR) with traditional open radical resection (ORR) in managing GBC. METHODS: A comprehensive search of online databases, including Medline (PubMed), Cochrane Library, and Web of Science, was conducted to identify comparative studies involving LRR and ORR in GBCs till March 2023. A meta-analysis was subsequently performed. RESULTS: A total of 18 retrospective studies were identified. In the long-term prognosis, the LRR group was comparable with the ORR group in terms of overall survival and tumor-free survival (TFS). LRR showed superiority in terms of TFS in the T2/tumor-node-metastasis (TNM) Ⅱ stage subgroup vs the ORR group (P = 0.04). In the short-term prognosis, the LRR group had superiority over the ORR group in the postoperative length of stay (POLS) (P < 0.001). The sensitivity analysis showed that all pooled results were robust. CONCLUSION: The meta-analysis results show that LRR is not inferior to ORR in all measured outcomes and is even superior in the TFS of patients with stage T2/TNM Ⅱ disease and POLS. Surgeons with sufficient laparoscopic experience can perform LRR as an alternative surgical strategy to ORR.

Formative objective structured clinical examination with immediate feedback improves surgical clerks' self-confidence and clinical competence.

OBJECTIVE: Clerkship is crucial for fourth-year medical students before entering the clinical environment. However, lack of confidence impairs clerks' performance during the clinical rotation. We assess the impact of formative Objective Structured Clinical Examination (OSCE) with immediate feedback on surgical clerks' self-confidence and clinical competence. METHODS: This is a prospective randomized controlled study. Thirty-eight fourth-year medical students starting their surgical clerkship were randomly divided into the control group (n = 19) and the OSCE group (n = 19), where an extra 6-station formative OSCE was given prior to the surgical rotation with immediate feedback on the participant's performance. Self-confidence assessment (SCA) was collected from each participant before, right after the formative OSCE and one month later. Clinical competence was assessed using a mini-clinical evaluation exercise (mini-CEX) with a case of acute abdominal pain and direct observation of procedural skills (DOPS) with incision and suture one month later. RESULTS: The SCAs were significantly improved in the OSCE group right after the training, and a month later, compared to the control group. The mini-CEX score was significantly higher in the OSCE group compared to the control group, but not the DOPS score of incision and suture. CONCLUSION: The formative OSCE with immediate feedback could significantly enhance surgical clerks' self-confidence and their clinical competence when taking the history, performing the physical examination, and in clinical reasoning; however, the formative OSCE did not improve their dexterity in performing the procedural skills.

Case report: Stent-first strategy as a potential approach in the management of malignant right-sided colonic obstruction with cardiovascular risks.

In obstructing left-sided colonic or rectal cancer, endoscopic stent placement with the purpose of decompression and bridge to elective colon resection has been widely utilized and accepted. However, in malignant right-sided colonic obstruction, stent placement prior to colectomy is still highly controversial, due to lower clinical success and high anastomotic leak. We report a case of malignant right-sided colonic obstruction based on the radiological findings of irregular thickening of ascending colon wall and dilation of proximal large bowel on enhanced computed tomography scan. The 72-year-old woman presented with obvious abdominal distension. Due to concerning cardiovascular complications as intermittent chest pain and a long history of type 2 diabetes, a three-step therapeutic plan was instigated. Initially, a self-expandable metallic stent was placed palliatively to relieve the bowel obstruction. Consecutively, coronary angiography was performed, and two coronary stents were implanted to alleviate more than 80% stenosis of two main coronary arteries. One month later, laparoscopic radical resection of right colon and lymphadenectomy were successfully performed, with a blood loss less than 50 millimeters and a harvest of 29 lymph nodes, 1 being positive. The patient was discharged one week postoperatively with no complications, and received adjuvant chemotherapy one month later. During a follow-up of more than one year, the patient was in complete remission with no recurrence and cardiovascular events. In patients presenting with malignant right-sided colonic obstruction and peril of high cardiovascular risks, we propose colonic and coronary stent-first strategy to emergency surgery as a potential approach so as to ensure sufficient cardiovascular preparation improving perioperative safety. Moreover, the anatomical location of the tumor would be significantly achievable thus granting high-quality radical colon resection and lymphadenectomy.

A putative causality of vitamin D in common diseases: A mendelian randomization study.

Backgrounds: Vitamin D is considered as a nutrient protecting individuals against an array of diseases based on observational studies. Such a protective effect, however, has not been demonstrated by randomized controlled trials. This study aims to explore a putative causal role of vitamin D in common diseases through a two-sample Mendelian randomization (MR) framework. Methods: Circulating vitamin D was predicted by 41 genetic variants discovered in European populations. Common diseases were verified through two ways, using information from Japanese patients of Biobank Japan and using information from European patients of FinnGen project. We additionally validated the results by replacing vitamin D-associated instrumental variables (IVs) of European population with that of an independent Japanese population and of an independent Indian population. Inverse-variance weighted method was used as the primary analytical approach while a series of MR methods including MR-Egger regression, weighted median, maximum likelihood, MR-PRESSO and multivariate MR were adopted to guarantee MR model assumptions and to detect horizontal pleiotropy. Results: Genetically predicted vitamin D was significantly associated with an increased risk of Graves' disease (OR = 1.71, 95%CI: 1.25-2.33, P = 0.001) and cataract (OR = 1.14, 95%CI: 1.03-1.28, P = 0.016); while with a decreased risk of esophageal cancer (OR = 0.66, 95%CI: 0.46-0.93, P = 0.019). This significant causal link between vitamin D and cataract was validated replacing IVs identified in the European population with those from Japanese population. No notable associations of vitamin D with other diseases were observed. Conclusions: Our findings indicate a potential causal role of vitamin D in common diseases, which needs further validation.

Evolution of Immunotherapy for Ovarian Cancer from a Bird's-Eye Perspective: A Text-Mining Analysis of Publication Trends and Topics.

Objectives: Ovarian tumors are among the most prominent gynecological malignancies and have a poor prognosis. Immunotherapy has undergone incredible progress in the past two decades. Our study aimed to use a bibliometric approach to identify research trends in ovarian cancer immunotherapy. Methods: Literature on this topic published from 2000-2020 was retrieved from the Web of Science Core Citation database and analyzed using the bibliometric analysis software VOSviewer and CiteSpace. Results: A total of 1729 articles on ovarian cancer immunotherapy published from January 2000 to December 2020 were identified. The number of published articles increased each year, from 40 in 2000 to 209 in 2020. These publications were from 61 countries, and the USA showed a dominant position in publication output, total citations, and average number of citations per paper. Co-citation networks revealed 14 subtopics. 'PD-L1 expression,' 'tumor reactive til,' and 'parp inhibitor' are the current potential subtopics. Furthermore, we determined research trends according to the timeline analysis. Conclusion: Our study exhaustively describes the development and summarizes the research trends of ovarian cancer immunotherapy over the past 20 years.

Radiomics-clinical nomogram for response to chemotherapy in synchronous liver metastasis of colorectal cancer: Good, but not good enough.

There remains a persistent unmet need to detect the disease nonresponse (nonDR) subgroup before adjuvant therapy in synchronous liver metastasis patients with colorectal cancer. Ma's radiomics-clinical nomogram shows potential for the early detection of nonDR subgroups, but it is not good enough owing to at least three limitaions, which we address in this letter to the editor. First, the study did not explore RAS/BRAF mutations, HER2 amplifications, etc. to complement the current nomogram. Second, the nomogram was not validated in left- and right-sided tumors separately. Third, the most critical factor for determining the success of adjuvant therapy should be resectability rather than tumor size shrinkage, which was used in the study.

Validation of a three-dimensional printed dry lab pancreaticojejunostomy model in surgical assessment: a cross-sectional study.

OBJECTIVES: Until now, there have been few tools to evaluate whether a surgeon was technically ready to perform a safe pancreaticojejunostomy (PJ). In the current study, we aimed to evaluate whether a three-dimensional model could mimic a real surgical situation and distinguish between surgeons of different levels of experiences. DESIGN: A three-dimensional PJ dry laboratory model was printed. Eight experienced pancreatic surgeons were tasked to evaluate the appearance and tactile sensation of the model. Proficiency was scored based on 15 surgeons with various levels of pancreatic experience performing a PJ on the three-dimensional model. Additionally, the time of manipulation and NASA Task Load Index (NASA-TLX) scores were recorded for each operation. SETTING: Our study was conducted in multimedical centre in China. RESULTS: Compared with real surgical situations, this model had similar appearance (3.96±0.55 out of five points) and tactile sensation (3.85±0.46 out of five points) according to the expert evaluation. Additionally, the chief surgeon group scored the best in proficiency (based on NASA-TLX scores and operative time), and there were statistical differences for performances among surgeons of various levels (p<0.05). CONCLUSION: The three-dimensional PJ model could mimic a real surgical situation and can distinguish between surgeons of different levels of experiences.

Laparoscopic surgery and robotic surgery for hilar cholangiocarcinoma: an updated systematic review.

BACKGROUND: The role of laparoscopic surgery (Lap) and robotic surgery (Rob) for radical resection of hilar cholangiocarcinoma (HC) is not clear. We summarized the safety and feasibility of Lap and Rob for HC. METHODS: A search of all HC studies in English published on PubMed up to April 2020 was conducted. References from retrieved articles were reviewed to broaden the search. RESULTS: In total, 23 reports were enrolled: 15 involving Lap, seven using Rob and one study reporting a minimally invasive approach (Lap or Rob, not specified). A total of 205 cases of HC were documented (Lap/Rob/not specified, 99/101/5): 37 cases of Bismuth type-I (Lap/Rob, 17/20), 22 cases of Bismuth type-II (Lap/Rob, 15/7), 68 cases of type-III (Lap/Rob, 39/29) and 13 cases of type-IV (Lap/Rob, 9/4). The pooled prevalence of R0 resection was 80.1% (Lap/Rob, 85.9%/71.0%). The weighted mean for operative time, blood loss and post-operative hospital stay was 458.4 min (Lap/Rob, 423.3/660.8 min), 615.3 mL (Lap/Rob, 521.0/1188.5 mL) and 14.0 days (Lap/Rob, 14.0/13.7 days), respectively. The pooled prevalence of conversion to open surgery, post-operative complications, and perioperative mortality was 9.1% (Lap/Rob, 12.2%/3.8%), 47.2% (Lap/Rob, 38.4%/61.3%) and 3.0% (Lap/Rob, 4.0%/2.0%), respectively. CONCLUSION: With innovations in technology and gradual accumulation of surgical experience, the feasibility and safety of performing Lap and Rob for HC will improve.

Association of circulating 25-Hydroxyvitamin D and its related genetic variations with hepatocellular carcinoma incidence and survival.

BACKGROUND: Vitamin D plays a key role of anti-cancer process, however, the association of vitamin D level and its related genetic variants with hepatocellular carcinoma (HCC) risk and prognosis is not fully understood. METHODS: We enrolled 100 HCC patients and 8,242 health controls from Sir Run Run Shaw Hospital. Logistic regression model was used to calculate the odds ratio (OR) and 95% CI for HCC risk according to serum 25(OH)D concentration. Mendelian randomization (MR) approach was also conducted to validate the potential causal association of 25(OH)D with HCC risk. Hazard ratio (HR) for the association of SNPs with overall survival and disease-free survival was assessed by multivariate Cox hazard proportional regression model. RESULTS: Plasma 25(OH)D level greater than 20 ng/mL increased HCC risk (OR =7.56, 95% CI: 4.58-12.50). MR analysis also showed a slightly increased risk of HCC by 25(OH)D increasing, yet did not reach statistical significance (OR =1.03, 95% CI: 0.31-3.47). With regard to HCC survival, compared to patients with rs8018720 GG genotype, patients with rs8018720 CC/CG genotype had a longer disease-free survival time (HR =0.39, 95% CI: 0.18-0.81). There was an interaction between rs12785878 and 25(OH)D level in continuous scale for HCC mortality. An interaction between rs12785878 and dichotomized 25(OH)D concentration for disease-free survival of HCC patients was also confirmed. CONCLUSIONS: There is hazard of circulating 25(OH)D concentration for HCC occurrence, but protective effect of the interaction between circulating 25(OH)D concentration and its related genetic variation for HCC prognosis. Further study is needed to confirm or refute these findings in a larger population.

Androgen receptor affects the response to immune checkpoint therapy by suppressing PD-L1 in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy with gender-related differences in onset and course. Androgen receptor (AR), a male hormone receptor, is critical in the initiation and progression of HCC. The role of AR in HCC has been mechanistically characterized and anti-AR therapies have been developed, showing limited efficacy. Immunotherapy targeting immune checkpoint proteins may substantially improve the clinical management of HCC. The mechanism by which AR influences HCC immune state remains unclear. In this study, we demonstrated that AR negatively regulated PD-L1, by acting as a transcriptional repressor of PD-L1. Notably, AR over-expression in HCC cells enhanced CD8+T function in vitro. We then verified the AR/PD-L1 correlation in patients. In animal experiment we found that lower AR expressed tumor achieved better response to PD-L1 inhibitor. Thus, AR suppressed PD-L1 expression, possibly contributing to gender disparity in HCC. Better understanding of the roles of AR during HCC initiation and progression will provide a novel angle to develop potential HCC immunotherapies.

Real-World Experience with AGA Guidelines in the Management of Crohn's Disease following Ileocolonic Resection: A Retrospective Cohort Study.

BACKGROUND: Postoperative endoscopic recurrence (PER) is common in patients with Crohn's disease (CD) after surgery. The impact of the American Gastroenterological Association (AGA) guideline adherence on PER in real life remains unclear. METHODS: The postoperative management of CD patients undergoing ileocolonic resection with anastomosis from 2017 to 2018 was conducted based on the AGA guidelines. Colonoscopies were performed within one year after surgery. Clinical data and risk factors for endoscopic recurrence were analyzed focusing on postoperative pharmacological prophylaxis. RESULTS: All patients were at a high risk of postoperative recurrence according to the AGA guidelines. PER occurred in 29 (28.7%) of these patients. The overall PER rate was 39.2% at one year. The PER rate in patients treated with nitroimidazole, thiopurines, infliximab, or a combination of thiopurines and infliximab for postoperative prophylaxis was 88.1%, 34.1%, 20.5%, and 0%, respectively. Cox regression showed that smoking at the time of surgery and AGA guideline adherence were independent factors associated with PER (HR: 3.75, 95% CI: 1.36-10.33, P = 0.01; HR: 0.36, 95% CI: 0.15-0.86, P = 0.02). In addition, further investigation revealed that educational background was the main factor related to patients' nonadherence to AGA guidelines. CONCLUSIONS: The majority of CD patients who undergo surgery in clinical practice may be at a high risk of disease recurrence. Thiopurines and infliximab are effective in preventing endoscopic recurrence. Guideline nonadherence is associated with PER at one year, thus indicating that there is room for improvement in adherence to the AGA guidelines.

A Comparison Between the Prognosis of Simultaneous and Salvage Radical Resection in Incidental Gallbladder Cancer.

PURPOSE: Incidental gallbladder cancer (IGBC) is defined as gallbladder cancer (GBC) that is accidentally discovered during cholecystectomy to treat benign lesions. We aimed to compare the prognosis of IGBC patients who underwent simultaneous radical resection (SIR) vs salvage radical resection (SAR). PATIENTS AND METHODS: We retrospectively reviewed data for IGBC patients admitted to Sir Run Run Shaw Hospital from January 2000 to May 2016. Survival analysis was performed using Kaplan-Meier (univariate) and COX regression (multivariate) analyses. RESULTS: Eighty-four patients with IGBC underwent radical resection; 43/84 underwent SIR, and 41/84 underwent SAR. Compared with SIR, the SAR group was more likely to receive comprehensive preoperative radiographic evaluation, port-site excision, and have more lymph nodes excised (all P < 0.05). Kaplan-Meier analysis indicated that the prognosis in the SAR group was better than that in SIR (overall survival: P = 0.050, recurrence-free survival: P = 0.028). Regression analysis indicated that the type of radical resection (SIR/SAR) was not an independent prognostic factor (overall survival: P = 0.737, recurrence-free survival: P = 0.957). CONCLUSION: Patients undergoing SAR had non-inferior survival compared with SIR. It is possible that patients in SAR underwent preoperative radiographical evaluations more comprehensively and the surgical operations were more well performed.

Is It Time to Consider Laparoscopic Hepatectomy for Intrahepatic Cholangiocarcinoma? A Meta-Analysis.

OBJECTIVES: The role of laparoscopic hepatectomy (LH) for intrahepatic cholangiocarcinoma (ICC) remains indefinite, though the utilization of this minimally invasive approach has been increasing for ICC. We herein performed a meta-analysis to investigate this issue. METHODS: Six retrospective studies including 384 patients who had undergone LH and 2147 patients who had undergone open hepatectomy (OH) for ICC were included. The fixed-effects or random-effects models were utilized for data analysis. RESULTS: Compared with patients who had undergone OH for ICC, patients who had undergone LH for ICC experienced more R0 resections (81.6 versus 73.8%, risk ratio (RR) = 1.08, 95% confidence interval (CI) 1.02-1.14; P = 0.008) but less major hepatectomies (37.7 versus 54.2%, RR = 0.69, 95% CI 0.60-0.79; P < 0.0001), less lymph node dissections (38.0 versus 61.5%, RR = 0.62, 95% CI 0.54-0.70; P < 0.0001), and smaller tumor size resected (4.14 versus 4.94 cm, weighted mean difference = - 0.80 cm, 95% CI - 1.38 to - 0.22 cm; P = 0.007). No significant difference was observed in other perioperative results (all P > 0.05) or overall survival (hazard ratio (HR) = 1.38, 95% CI 0.63-3.02; P = 0.43). CONCLUSIONS: LH has comparable safety, feasibility, and oncological efficacy to that of OH for ICC and has superiority in R0 resection over OH. It may be time to consider LH for ICC only if a more thorough effort on lymph node dissection is undertaken in selective patients at experienced centers.

Population-level utilization of anatomic resection in early hepatocellular carcinoma (≤5 cm): post-operative, middle- and long-term outcomes.

BACKGROUND: Most of previous researches on anatomic resection (AR) in early hepatocellular carcinoma (HCC) were conducted in high-volume centres with controversial results. This study aims to provide evidence of the utilization of AR in early HCC at population level. METHODS: The Surveillance, Epidemiology, and End Results 18 registries database (2004-2015) of the USA was utilized to identify early HCC cases ≤5 cm. Overall survival and cancer-specific survival were both analysed. RESULTS: A total of 976 AR and 409 wedge resection (WR) cases were identified. For the post-operative (death within 1 month) and middle-term (death within 3 years) survival, effect of AR was found to be similar to that of WR after adjusting other covariates. However, for the long-term (death within 5 years) survival, the therapeutic effect of AR proved to be superior to that of WR (relative risk (RR) 0.655 for overall survival; RR 0.658 for cancer-specific survival, both P < 0.05). Furthermore, subgroup analyses suggested that patients characterizing as male, tumour size 1-30 mm, vascular invasion and normal alpha-fetoprotein were more likely to benefit from AR in long-term prognosis (all P < 0.05). CONCLUSIONS: This study suggests that AR, when adopted at population level, is a better choice in comparison with WR in early HCC based on the evidences that it could provide equivalent post-operative, middle-term prognosis and superior long-term survival.

Cystic duct cancer: Should it be deemed as a type of gallbladder cancer?

BACKGROUND: According to the latest American Joint Committee on Cancer and Union for International Cancer Control manuals, cystic duct cancer (CC) is categorized as a type of gallbladder cancer (GC), which has the worst prognosis among all types of biliary cancers. We hypothesized that this categorization could be verified by using taxonomic methods. AIM: To investigate the categorization of CC based on population-level data. METHODS: Cases of biliary cancers were identified from the Surveillance, Epidemiology, and End Results 18 registries database. Together with routinely used statistical methods, three taxonomic methods, including Fisher's discriminant, binary logistics and artificial neuron network (ANN) models, were used to clarify the categorizing problem of CC. RESULTS: The T staging system of perihilar cholangiocarcinoma [a type of extrahepatic cholangiocarcinoma (EC)] better discriminated CC prognosis than that of GC. After adjusting other covariates, the hazard ratio of CC tended to be closer to that of EC, although not reaching statistical significance. To differentiate EC from GC, three taxonomic models were built and all showed good accuracies. The ANN model had an area under the receiver operating characteristic curve of 0.902. Using the three models, the majority (75.0%-77.8%) of CC cases were categorized as EC. CONCLUSION: Our study suggested that CC should be categorized as a type of EC, not GC. Aggressive surgical attitude might be considered in CC cases, to see whether long-term prognosis could be immensely improved like the situation in EC.

Wnt signaling in liver disease: emerging trends from a bibliometric perspective.

BACKGROUND: The Wnt signaling pathway, an evolutionarily conserved molecular transduction cascade, has been identified as playing a pivotal role in various physiological and pathological processes of the liver, including homeostasis, regeneration, cirrhosis, and hepatocellular carcinoma (HCC). In this study, we aimed to use a bibliometric method to evaluate the emerging trends on Wnt signaling in liver diseases. METHODS: Articles were retrieved from the Web of Science Core Collection. We used a bibliometric software, CiteSpace V 5.3.R4, to analyze the active countries or institutions in the research field, the landmark manuscripts, important subtopics, and evolution of scientific ideas. RESULTS: In total, 1,768 manuscripts were published, and each was cited 33.12 times on average. The U.S. published most of the articles, and the most active center was the University of Pittsburgh. The top 5 landmark papers were identified by four bibliometric indexes including citation, burstness, centrality, and usage 2013. The clustering process divided the whole area into nine research subtopics, and the two major important subtopics were "liver zonation" and "HCC." Using the "Part-of-Speech" technique, 1,743 terms representing scientific ideas were identified. After 2008, the bursting phrases were "liver development," "progenitor cells," "hepatic stellate cells," "liver regeneration," "liver fibrosis," "epithelial-mesenchymal transition," and etc. CONCLUSION: Using bibliometric methods, we quantitatively summarized the advancements and emerging trends in Wnt signaling in liver diseases. These bibliometric findings may pioneer the future direction of this field in the next few years, and further studies are needed.

DUSP1 inhibits cell proliferation, metastasis and invasion and angiogenesis in gallbladder cancer.

DUSP1/MKP1 is a dual-specific phosphatase that regulates MAPK activity and is known to play a key role in tumor biology. Its function in gallbladder cancer (GBC) remains largely unknown, however. By exploring its activities in two GBC cell lines (SGC996 and GBC-SD), DUSP1 was found to inhibit GBC cell proliferation, migration and invasion. Moreover, DUSP1 inhibited GBC growth and metastasis in nude mice subcutaneously xenografted with SGC996 cells. The tumor suppression appeared to be mediated via the DUSP1-pERK/MAPK-MMP2 signal pathway. Angiogenesis was associated with the tumor metastasis in the mouse model and was impaired by DUSP1, which suppressed VEGF expression. These results suggest that DUSP1 suppresses GBC growth and metastasis by targeting the DUSP1-pERK-MMP2/VEGF axis. Identification of the DUSP1-pERK-MMP2/VEGF signals may provide new biomarkers and/or therapeutic targets to better suppress GBC metastasis in the future.

Expression of transforming growth factor ß1 promotes cholangiocarcinoma development and progression.

BACKGROUND AND AIMS: The role of transforming growth factor beta 1 (TGFß1) in cholangiocarcinoma (CCA) initiation and growth requires further definition. METHODS: We employed pharmacological and genetic approaches to inhibit or enhance TGFß1 signaling, respectively, and determine the cellular mechanisms involved. RESULTS: It was observed that inhibiting TGFß1 activity with short hairpin RNA (shRNA) or pharmaceutical agents suppressed CCA development and growth, whereas overexpression of TGFß1 enhanced CCA tumor size and promoted intrahepatic metastasis in a rat model. Suppression of TGFß1 activity inhibits downstream target gene expression mediated by miR-34a that includes cyclin D1, CDK6, and c-Met. In addition, "knockdown" of TGFß1 expression revealed a miR-34a positive feedback mechanism for enhanced p21 expression in CCAs. A miR-34a inhibitor reversed the effects of "knocking down" TGFß1 on cell growth, migration, cyclin D1, CDK6 and c-Met expression, suggesting that TGFß1 mediated effects occur, in part, through this miR-34a signaling pathway. Overexpression of TGFß1 was associated with CCA tumor progression. CONCLUSIONS: This study suggests that TGFß1 is involved in CCA tumor progression and participates through miR-34a mediated downstream cascades, and is a target to inhibit CCA development and growth.

Anti-Tumor Effects of Second Generation ß-Hydroxylase Inhibitors on Cholangiocarcinoma Development and Progression.

Cholangiocarcinoma (CCA) has a poor prognosis due to widespread intrahepatic spread. Aspartate ß-hydroxylase (ASPH) is a transmembrane protein and catalyzes the hydroxylation of aspartyl and asparaginyl residues in calcium binding epidermal growth factor (cbEGF)-like domains of various proteins, including Notch receptors and ligands. ASPH is highly overexpressed (>95%) in human CCA tumors. We explored the molecular mechanisms by which ASPH mediated the CCA malignant phenotype and evaluated the potential of ASPH as a therapeutic target for CCA. The importance of expression and enzymatic activity of ASPH for CCA growth and progression was examined using shRNA "knockdown" and a mutant construct that reduced its catalytic activity. Second generation small molecule inhibitors (SMIs) of ß-hydroxylase activity were developed and used to target ASPH in vitro and in vivo. Subcutaneous and intrahepatic xenograft rodent models were employed to determine anti-tumor effects on CCA growth and development. It was found that the enzymatic activity of ASPH was critical for mediating CCA progression, as well as inhibiting apoptosis. Mechanistically, ASPH overexpression promoted Notch activation and modulated CCA progression through a Notch1-dependent cyclin D1 pathway. Targeting ASPH with shRNAs or a SMI significantly suppressed CCA growth in vivo.