Accuracy and Reliability of Chatbot Responses to Physician Questions.

Importance: Natural language processing tools, such as ChatGPT (generative pretrained transformer, hereafter referred to as chatbot), have the potential to radically enhance the accessibility of medical information for health professionals and patients. Assessing the safety and efficacy of these tools in answering physician-generated questions is critical to determining their suitability in clinical settings, facilitating complex decision-making, and optimizing health care efficiency. Objective: To assess the accuracy and comprehensiveness of chatbot-generated responses to physician-developed medical queries, highlighting the reliability and limitations of artificial intelligence-generated medical information. Design, Setting, and Participants: Thirty-three physicians across 17 specialties generated 284 medical questions that they subjectively classified as easy, medium, or hard with either binary (yes or no) or descriptive answers. The physicians then graded the chatbot-generated answers to these questions for accuracy (6-point Likert scale with 1 being completely incorrect and 6 being completely correct) and completeness (3-point Likert scale, with 1 being incomplete and 3 being complete plus additional context). Scores were summarized with descriptive statistics and compared using the Mann-Whitney U test or the Kruskal-Wallis test. The study (including data analysis) was conducted from January to May 2023. Main Outcomes and Measures: Accuracy, completeness, and consistency over time and between 2 different versions (GPT-3.5 and GPT-4) of chatbot-generated medical responses. Results: Across all questions (n = 284) generated by 33 physicians (31 faculty members and 2 recent graduates from residency or fellowship programs) across 17 specialties, the median accuracy score was 5.5 (IQR, 4.0-6.0) (between almost completely and complete correct) with a mean (SD) score of 4.8 (1.6) (between mostly and almost completely correct). The median completeness score was 3.0 (IQR, 2.0-3.0) (complete and comprehensive) with a mean (SD) score of 2.5 (0.7). For questions rated easy, medium, and hard, the median accuracy scores were 6.0 (IQR, 5.0-6.0), 5.5 (IQR, 5.0-6.0), and 5.0 (IQR, 4.0-6.0), respectively (mean [SD] scores were 5.0 [1.5], 4.7 [1.7], and 4.6 [1.6], respectively; P = .05). Accuracy scores for binary and descriptive questions were similar (median score, 6.0 [IQR, 4.0-6.0] vs 5.0 [IQR, 3.4-6.0]; mean [SD] score, 4.9 [1.6] vs 4.7 [1.6]; P = .07). Of 36 questions with scores of 1.0 to 2.0, 34 were requeried or regraded 8 to 17 days later with substantial improvement (median score 2.0 [IQR, 1.0-3.0] vs 4.0 [IQR, 2.0-5.3]; P < .01). A subset of questions, regardless of initial scores (version 3.5), were regenerated and rescored using version 4 with improvement (mean accuracy [SD] score, 5.2 [1.5] vs 5.7 [0.8]; median score, 6.0 [IQR, 5.0-6.0] for original and 6.0 [IQR, 6.0-6.0] for rescored; P = .002). Conclusions and Relevance: In this cross-sectional study, chatbot generated largely accurate information to diverse medical queries as judged by academic physician specialists with improvement over time, although it had important limitations. Further research and model development are needed to correct inaccuracies and for validation.

Assessing the Accuracy and Reliability of AI-Generated Medical Responses: An Evaluation of the Chat-GPT Model.

Background: Natural language processing models such as ChatGPT can generate text-based content and are poised to become a major information source in medicine and beyond. The accuracy and completeness of ChatGPT for medical queries is not known. Methods: Thirty-three physicians across 17 specialties generated 284 medical questions that they subjectively classified as easy, medium, or hard with either binary (yes/no) or descriptive answers. The physicians then graded ChatGPT-generated answers to these questions for accuracy (6-point Likert scale; range 1 - completely incorrect to 6 - completely correct) and completeness (3-point Likert scale; range 1 - incomplete to 3 - complete plus additional context). Scores were summarized with descriptive statistics and compared using Mann-Whitney U or Kruskal-Wallis testing. Results: Across all questions (n=284), median accuracy score was 5.5 (between almost completely and completely correct) with mean score of 4.8 (between mostly and almost completely correct). Median completeness score was 3 (complete and comprehensive) with mean score of 2.5. For questions rated easy, medium, and hard, median accuracy scores were 6, 5.5, and 5 (mean 5.0, 4.7, and 4.6; p=0.05). Accuracy scores for binary and descriptive questions were similar (median 6 vs. 5; mean 4.9 vs. 4.7; p=0.07). Of 36 questions with scores of 1-2, 34 were re-queried/re-graded 8-17 days later with substantial improvement (median 2 vs. 4; p<0.01). Conclusions: ChatGPT generated largely accurate information to diverse medical queries as judged by academic physician specialists although with important limitations. Further research and model development are needed to correct inaccuracies and for validation.

Interpreting the risk analysis index of frailty in the context of surgical oncology.

BACKGROUND AND OBJECTIVES: The Risk Analysis Index (RAI) accurately predicts adverse postoperative outcomes but the inclusion of cancer status in the RAI has raised two key concerns about its suitability for use in surgical oncology: (1) the potential over classification of cancer patients as frail, and (2) the potential overestimation of postoperative mortality for patients with surgically curable cancers. METHODS: We performed a retrospective cohort analysis to assess the RAI's power to appropriately identify frailty and predict postoperative mortality in cancer patients. We assessed discrimination for mortality and calibration across five RAI models-the complete RAI and four variants that removed different cancer-related variables. RESULTS: We found that the presence of disseminated cancer was a key variable driving the RAI's power to predict postoperative mortality. The model including only this variable [RAI (disseminated cancer)] was similar to the complete RAI in the overall sample (c = 0.842 vs. 0.840) and outperformed the complete RAI in the cancer subgroup (c = 0.736 vs 0.704, respectively, p < 0.0001, Max R2 = 19.3% vs. 15.1%, respectively). CONCLUSION: The RAI demonstrates somewhat less discrimination when applied exclusively to cancer patients, but remains a strong predictor of postoperative mortality, especially in the setting of disseminated cancer.

Stapled Full-Thickness Diaphragm Resection: A Novel Approach to Diaphragmatic Resection in Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy.

Full-thickness diaphragm resection (FT-DR) during cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is sometimes required to achieve a complete cytoreduction. It is conventionally performed with electrocautery with primary repair or mesh repair. FT-DR using a linear cutting stapler is a novel technique that avoids entry to the chest cavity and minimizes the use of electrocautery on the diaphragm. We performed an institutional retrospective review of a prospectively maintained database of 145 patients who underwent CRS-HIPEC between 2013 and 2019. Patients were divided into the Conventional or Stapled group based on the FT-DR approach indicated in the operative report. Of the 145 patients who underwent CRS-HIPEC, 27 underwent FT-DR, with 63% (n = 17) in the Stapled group. There were no significant demographic or oncologic differences between the 2 groups. Patients in the Stapled group underwent tube thoracostomy (13.3% vs 60%; p = 0.008), were diagnosed with pneumonia (12% vs 50%; p = 0.04), required reintubation (6% vs 40%; p = 0.03), and required mechanical ventilation more than 48 hours (6% vs 50%; p = 0.02) less frequently than the Conventional group. There was no difference in pleural recurrence between the 2 groups (Conventional 20% vs Stapled 12%, p = 0.56). Stapled full-thickness diaphragm resection is a novel approach to achieving a complete cytoreduction that excludes the pleural cavity, minimizes diaphragm manipulation, and is associated with improved postoperative pulmonary outcomes in patients undergoing CRS-HIPEC.

The Role of Simulation in Attaining Proficiency in Minimally Invasive Hepatopancreatobiliary Surgery.

The implementation of robotic surgery in the field of hepato-pancreato-biliary (HPB) has been a slow but significant process. HPB procedures offer a unique challenge when for new technologies, as the surgeries themselves are complex, with long learning curves. Yet the benefits of the robotic approach for this patient population are notable: decreased length of stay, blood loss, postoperative complications, and improving quality of life. The use of robotic simulation focused curriculum plays a crucial role in mentoring experienced surgeons and surgical trainees. Although further study remains, early studies suggest a structured simulation curriculum decreases time, technical errors, and improves proficiency, ultimately leading to a more expedited and safe implementation of robotic techniques in the HPB field.

Non-Invasive Venous waveform Analysis (NIVA) for volume assessment during complex cranial vault reconstruction: A proof-of-concept study in children.

BACKGROUND: Non-Invasive Venous waveform Analysis (NIVA) is novel technology that captures and analyzes changes in venous waveforms from a piezoelectric sensor on the wrist for hemodynamic volume assessment. Complex cranial vault reconstruction is performed in children with craniosynostosis and is associated with extensive blood loss, potential life-threatening risks, and significant morbidity. In this preliminary study, we hypothesized that NIVA will provide a reliable, non-invasive, quantitative assessment of intravascular volume changes in children undergoing complex cranial vault reconstruction. OBJECTIVE: To present proof-of-concept results of a novel technology in the pediatric population. METHODS: The NIVA prototype was placed on each subject's wrist, and venous waveforms were collected intraoperatively. Estimated blood loss and fluid/blood product administration were recorded in real time. Venous waveforms were analyzed into a NIVA value and then correlated, along with mean arterial pressure (MAP), to volume changes. Concordance was quantified to determine if the direction of change in volume was similar to the direction of change in MAP or change in NIVA. RESULTS: Of 18 patients enrolled, 14 had usable venous waveforms, and there was a significant correlation between change in NIVA value and change in volume. Change in MAP did not correlate with change in volume. The concordance between change in MAP and change in volume was less than the concordance between change in NIVA and change in volume. CONCLUSION: NIVA values correlate more closely to intravascular volume changes in pediatric craniofacial patients than MAP. This initial study suggests that NIVA is a potential safe, reliable, non-invasive quantitative method of measuring intravascular volume changes for children undergoing surgery.

Primary Tumor Resection Offers Survival Benefit in Patients with Metastatic Midgut Neuroendocrine Tumors.

BACKGROUND: Approximately 35% of patients with midgut neuroendocrine tumors (MNET) present with distant metastases. Although successful resection of these metastatic foci improves overall survival (OS), the role of primary tumor resection (PTR) in patients with unresectable metastatic disease is unclear. The aim of this study is to evaluate prevalence and survival impact of PTR in patients with unresectable metastatic MNET. PATIENTS AND METHODS: A retrospective cohort study of patients with metastatic MNET was performed using the National Cancer Database (2004-2014). Demographic and clinicopathologic variables were compared between patients who did and did not undergo PTR. Survival analysis was performed using Kaplan-Meier and log-rank tests. Multivariable regression analysis was used to assess factors associated with PTR and all-cause mortality. RESULTS: The cohort included 4076 patients; 2520 (61.8%) underwent PTR. Patients more likely to undergo PTR were younger and diagnosed earlier, underwent treatment at a nonacademic facility, lived on the West Coast or in the Central USA, and presented with smaller lower-grade small bowel primary tumors. Median OS was improved for patients who underwent PTR compared with those who did not (71 vs. 29 months, p < 0.001). On multivariable analysis, younger age, Black race, higher income, later year of diagnosis, treatment at an academic facility, private insurance, fewer comorbidities, small bowel primary, lower grade, and PTR (hazard ratio 0.63, 95% confidence interval 0.51-0.78, p < 0.001) were associated with lower mortality. CONCLUSIONS: PTR was associated with improved OS. Further study is needed to understand how clinicians select patients for PTR.

Reversible deficits in apical transporter trafficking associated with deficiency in diacylglycerol acyltransferase.

Deficiency in diacylglycerol acyltransferase (DGAT1) is a rare cause of neonatal diarrhea, without a known mechanism or in vitro model. A patient presenting at our institution at 7 weeks of life with failure to thrive and diarrhea was found by whole-exome sequencing to have a homozygous DGAT1 truncation mutation. Duodenal biopsies showed loss of DGAT1 and deficits in apical membrane transporters and junctional proteins in enterocytes. When placed on a very low-fat diet, the patient's diarrhea resolved with normalization of brush border transporter localization in endoscopic biopsies. DGAT1 knockdown in Caco2-BBe cells modeled the deficits in apical trafficking, with loss of apical DPPIV and junctional occludin. Elevation in cellular lipid levels, including diacylglycerol (DAG) and phospholipid metabolites of DAG, was documented by lipid analysis in DGAT1 knockdown cells. Culture of the DGAT1 knockdown cells in lipid-depleted media led to re-establishment of occludin and return of apical DPPIV. DGAT1 loss appears to elicit global changes in enterocyte polarized trafficking that could account for deficits in absorption seen in the patient. The in vitro modeling of this disease should allow for investigation of possible therapeutic targets.

Evolution of a level I pediatric trauma center: Changes in injury mechanisms and improved outcomes.

BACKGROUND: Trauma is the leading cause of mortality among children, underscoring the need for specialized child-centered care. The impact on presenting mechanisms of injury and outcomes during the evolution of independent pediatric trauma centers is unknown. The aim of this study was to evaluate the impact of our single center transition from an adult to American College of Surgeons-verified pediatric trauma center. METHODS: A retrospective analysis was performed of 1,190 children who presented as level I trauma activations between 2005 and 2016. Patients were divided into 3 chronological treatment eras: adult trauma center, early pediatric trauma center, and late pediatric trauma center after American College of Surgeons verification review. Comparisons were made using Pearson χ2, Wilcoxon rank sum, and Kruskal-Wallis tests. RESULTS: The predominant mechanism of injury was motor vehicle crash, with increases noted in assault/abuse (2% adult trauma center, 11% late pediatric trauma center). A decrease in intensive care admissions was identified during late pediatric trauma center compared with early pediatric trauma center and adult trauma center (51% vs 62.4% vs 67%, P < .001), with concomitant increases in admissions to the floor and immediate operative interventions, but overall mortality was unchanged. CONCLUSION: Transition to a verified pediatric trauma center maintains the safety expected of the American College of Surgeons certification, but with notable changes identified in mechanism of injury and improvements in resource utilization.

Meta-analysis of surgeon-performed central line placement: Real-time ultrasound versus landmark technique.

BACKGROUND: Major health care agencies recommend real-time ultrasound (RTUS) guidance during insertion of percutaneous central venous catheters (CVC) based on studies in which CVCs were placed by nonsurgeons. We conducted a meta-analysis to compare outcomes for surgeon-performed RTUS-guided CVC insertion versus traditional landmark technique. METHODS: A systematic review of the literature was performed, identifying randomized controlled trials (RCT) and prospective "safety studies" of surgeon-performed CVC insertions comparing landmark to RTUS techniques. Searches were conducted in MEDLINE, Cochrane, and Web of Science, with additional relevant articles identified through examination of the bibliographies and citations of the included studies. Two independent reviewers selected relevant studies that matched inclusion criteria, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. A meta-analysis was conducted using random effects models to compare success and complication rates. RESULTS: Three RCTs were identified totaling 456 patients. The RTUS guidance was associated with better first attempt success (odds ratio [OR], 4.7; 95% confidence interval [CI], 1.5-14.7, p = 0.008) and overall success (OR 6.5, 95% CI: 2.7-15.7, p < 0.0001). However, there were no differences in overall complication (OR 1.9 (95% CI, 0.8-4.4, p = 0.14)) or arterial puncture (OR 2.0 (95% CI, 0.7-5.6, p = 0.18) rates between the two methods. CONCLUSION: Despite many studies involving nonsurgeons, there are only three RCTs comparing RTUS versus landmark technique for surgeon-performed CVC placement. The RTUS guidance is associated with better success than landmark technique, but no difference in complication rates. No study evaluated how RTUS was implemented. Larger studies examining RTUS use during surgeon-performed CVC placements are needed. LEVEL OF EVIDENCE: Systematic review and meta-analysis, level III.

Apical Membrane Alterations in Non-intestinal Organs in Microvillus Inclusion Disease.

OBJECTIVES: Microvillus inclusion disease (MVID) is a severe form of neonatal diarrhea, caused mainly by mutations in MYO5B. Inactivating mutations in MYO5B causes depolarization of enterocytes in the small intestine, which gives rise to chronic, unremitting secretory diarrhea. While the pathology of the small intestine in MVID patients is well described, little is known about extraintestinal effects of MYO5B mutation. METHODS: We examined stomach, liver, pancreas, colon, and kidney in Navajo MVID patients, who share a single homozygous MYO5B-P660L (1979C>T p.Pro660Leu, exon 16). Sections were stained for markers of the apical membrane to assess polarized trafficking. RESULTS: Navajo MVID patients showed notable changes in H/K-ATPase-containing tubulovesicle structure in the stomach parietal cells. Colonic mucosa was morphologically normal, but did show losses in apical ezrin and Syntaxin 3. Hepatocytes in the MVID patients displayed aberrant canalicular expression of the essential transporters MRP2 and BSEP. The pancreas showed small fragmented islets and a decrease in apical ezrin in pancreatic ducts. Kidney showed normal primary cilia. CONCLUSIONS: These findings indicate that the effects of the P660L mutation in MYO5B in Navajo MVID patients are not limited to the small intestine, but that certain tissues may be able to compensate functionally for alterations in apical trafficking.

A signalling cascade of IL-33 to IL-13 regulates metaplasia in the mouse stomach.

OBJECTIVE: Alternatively activated macrophages (M2) are associated with the progression of spasmolytic polypeptide-expressing metaplasia (SPEM) in the stomach. However, the precise mechanism(s) and critical mediators that induce SPEM are unknown. DESIGN: To determine candidate genes important in these processes, macrophages from the stomach corpus of mice with SPEM (DMP-777-treated) or advanced SPEM (L635-treated) were isolated and RNA sequenced. Effects on metaplasia development after acute parietal cell loss induced by L635 were evaluated in interleukin (IL)-33, IL-33 receptor (ST2) and IL-13 knockout (KO) mice. RESULTS: Profiling of metaplasia-associated macrophages in the stomach identified an M2a-polarised macrophage population. Expression of IL-33 was significantly upregulated in macrophages associated with advanced SPEM. L635 induced metaplasia in the stomachs of wild-type mice, but not in the stomachs of IL-33 and ST2 KO mice. While IL-5 and IL-9 were not required for metaplasia induction, IL-13 KO mice did not develop metaplasia in response to L635. Administration of IL-13 to ST2 KO mice re-established the induction of metaplasia following acute parietal cell loss. CONCLUSIONS: Metaplasia induction and macrophage polarisation after parietal cell loss is coordinated through a cytokine signalling network of IL-33 and IL-13, linking a combined response to injury by both intrinsic mucosal mechanisms and infiltrating M2 macrophages.

Ambulatory bilateral neck exploration for primary hyperparathyroidism: is it safe?

BACKGROUND: We sought to determine if bilateral neck exploration (BNE) for hyperparathyroidism could be performed safely in an ambulatory setting (same-day discharge) when compared with focused parathyroidectomy. METHODS: A retrospective review of 503 patients who underwent parathyroidectomy from 2010 to 2015 was performed. Focused parathyroidectomy was compared with BNE. Only patients with positive localization and no prior operations were included. RESULTS: Forty-nine percent of patients underwent focused parathyroidectomy and 51% had BNE. BNE patients were more likely to have 1 or more glands removed (35% vs 14%, P < .01) and longer operative times (median 50 vs 41 minutes, P < .01). There were no differences in the rate of same-day discharge, transient hypocalcemia, emergency department visits, and readmissions. CONCLUSIONS: In this study, BNE for hyperparathyroidism was associated with excision of more parathyroid glands and slightly longer operative times. However, BNE had equal rates of same-day discharges and safety profile.

Does concomitant thyroidectomy increase risks of parathyroidectomy?

BACKGROUND: Concomitant thyroid pathology in patients with primary hyperparathyroidism is common. This study compares complications of patients who underwent parathyroidectomy to those who underwent parathyroidectomy with a concomitant thyroidectomy. METHODS: A retrospective review of prospectively collected data on 709 patients who underwent parathyroidectomy was performed. Patients who had prior thyroid or parathyroid procedures were excluded. Chi-square, Fisher's exact, Student's t-test, and Wilcoxon rank-sum tests were used to compare cohorts. RESULTS: Of the 641 patients included, 90% underwent parathyroidectomy alone and 10% underwent parathyroidectomy with a concomitant thyroidectomy. Overall, 49% had preoperative thyroid disease and 22% of patients with thyroid disease had a thyroid procedure. When compared with parathyroidectomy alone, parathyroidectomy with a concomitant thyroidectomy was associated with longer operative times (91 min versus 57 min, P < 0.001), increased rate of overnight stay (69% versus 17%, P < 0.001), and increased rate of transient hypocalcemia (15% versus 3%, P < 0.001). CONCLUSIONS: Parathyroidectomy with a concomitant thyroidectomy is associated with longer operative times, increased rate of overnight stay, and increased transient hypocalcemia.

Akt2 regulates metastatic potential in neuroblastoma.

Activation of PI3K/AKT pathway correlates with poor prognosis in patients with neuroblastoma. Our previous studies have demonstrated that PI3K/AKT signaling is critical for the oncogenic transformations induced by gastrin-releasing peptide (GRP) and its receptor, GRP-R, in neuroblastoma. Moreover, PI3K/AKT-dependent oncogenic transformations require N-myc, an extensively studied oncogene in neuroblastoma. Whether AKT directly regulates the expression of N-myc oncogene is yet to be determined. Here, we report a novel finding that of the three AKT isoforms, AKT2 specifically regulated N-myc expression in neuroblastoma cells. We also confirmed that GRP-R is upstream of AKT2 and in turn, regulated N-myc expression via AKT2 in neuroblastoma cells. Functional assays demonstrated that attenuation of AKT2 impaired cell proliferation and anchorage-independent cell growth, and decreased the secretion of angiogenic factor VEGF in vitro. Furthermore, silencing AKT2 inhibited migration and invasion of neuroblastoma cells in vitro. Xenografts established by injecting AKT2 silenced human neuroblastoma cells into murine spleen expressed decreased levels of AKT2 and resulted in fewer liver metastases compared to controls in vivo. Hence, our study highlights the potential molecular mechanism(s) mediating the oncogenic role of GRP/GRP-R and demonstrates a novel role for AKT2 in neuroblastoma tumorigenesis, indicating that targeting the GRP/GRP-R/AKT2 axis may be important for developing novel therapeutics in the treatment of clinically aggressive neuroblastoma.

Protein kinase C regulates bombesin-induced rapid VEGF secretion in neuroblastoma cells.

BACKGROUND: Intracellular signaling responsible for gastrin-releasing peptide (GRP) receptor-mediated neovascularization is not clearly understood. We sought to determine the cellular mechanisms involved in the GRP receptor regulation of vascular endothelial growth factor (VEGF) release in neuroblastoma cells. MATERIALS AND METHODS: BE(2)-C cells were treated with bombesin (BBS), the amphibian equivalent of GRP, Phorbol myristate acetate (PMA) a PKC agonist, or GF109293X (GFX), and analyses were performed for VEGF secretion, phosphorylated protein kinase B (AKT), extracellular signal-regulated kinases (ERK) and protein kinase D (PKD) expression. RESULTS: BBS rapidly increased VEGF secretion at 30 min. Pre-treatment with PMA alone produced similar results; this effect was synergistic with the addition of GRP. Conversely, GFX blocked PMA-stimulated increase in VEGF secretion. Immunofluorescent staining for VEGF correlated to BBS, PMA and GFX. CONCLUSION: PKC is critically responsible for rapid VEGF secretion by GRP receptor signaling in neuroblastoma cells. Inhibition of VEGF significantly reduced GRP-mediated cell proliferation, suggesting its crucial role in neuroblastoma tumorigenesis.

Congenital lung anomalies: can we postpone resection?

BACKGROUND/PURPOSE: The management of asymptomatic congenital lung lesions is controversial. It is unclear whether elective resection provides a significant benefit. We sought to determine whether early vs delayed resection of asymptomatic congenital lung malformations resulted in complications. METHODS: Institutional billing records were queried for patients with lung malformations over a 10-year period. Medical records were reviewed for demographics, type of anomaly, symptoms, management, and procedural or disease-related complications. RESULTS: Eighty-seven patients were identified. The diagnoses included congenital cystic adenomatoid malformation (41%), bronchogenic cyst (19.3%), sequestration (13.2%), and congenital lobar emphysema (12.0%). Fifty patients were observed for some period. Eleven became symptomatic, and 47 underwent resection at a mean age of 11 months. There was no difference in the type of resection, length of hospitalization, or complication rate between patients who underwent early vs delayed resection. There were no occurrences of malignancy or death. CONCLUSIONS: In our series, there was no difference in measurable outcomes between early and delayed resection of congenital lung lesions. These data provide some support for a management strategy that might include observation with delayed resection for asymptomatic patients.

Integrin-linked kinase regulates phosphatase and tensin homologue activity to promote tumorigenesis in neuroblastoma cells.

BACKGROUND: The phosphatidylinositol 3-kinase (PI3K), a critical intracellular pathway, is negatively regulated by phosphatase and tensin homologue (PTEN). Integrin-linked kinase (ILK) induces phosphorylation of Akt leading to an increase in cell survival. However, a potential interaction between ILK and PTEN activity in neuroblastoma cells is unknown. We sought to examine the relationship between ILK and PTEN in the PI3K/Akt signaling pathway in neuroblastoma tumorigenesis. METHODS: The human neuroblastoma cell line, BE(2)-C, was transfected with small interfering or short hairpin RNA to silence ILK expression. A plasmid containing the ILK wild-type (ILK wt) gene was transfected to overexpress ILK. Cell proliferation was assessed, and anchorage independence was measured by soft agar assay. Insulin-like growth factor-1 was used to stimulate the PI3K/Akt pathway. Protein levels were determined by Western blotting. RESULTS: Transient silencing of ILK produced correlative decreases in PTEN expression, cell proliferation, and soft agar colony formation. Conversely, stably transfected ILK knockdown cells showed an increase in phospho-Akt levels, leading to cell proliferation. CONCLUSION: ILK plays an important role in the regulation of PI3K/Akt pathway via PTEN or an upstream effector of PTEN. The effects of ILK silencing on PTEN expression seem to be critically dependent on duration of ILK dysregulation.