Cell surface CD55 traffics to the nucleus leading to cisplatin resistance and stemness by inducing PRC2 and H3K27 trimethylation on chromatin in ovarian cancer.

BACKGROUND: Platinum resistance is the primary cause of poor survival in ovarian cancer (OC) patients. Targeted therapies and biomarkers of chemoresistance are critical for the treatment of OC patients. Our previous studies identified cell surface CD55, a member of the complement regulatory proteins, drives chemoresistance and maintenance of cancer stem cells (CSCs). CSCs are implicated in tumor recurrence and metastasis in multiple cancers. METHODS: Protein localization assays including immunofluorescence and subcellular fractionation were used to identify CD55 at the cell surface and nucleus of cancer cells. Protein half-life determinations were used to compare cell surface and nuclear CD55 stability. CD55 deletion mutants were generated and introduced into cancer cells to identify the nuclear trafficking code, cisplatin sensitivity, and stem cell frequency that were assayed using in vitro and in vivo models. Detection of CD55 binding proteins was analyzed by immunoprecipitation followed by mass spectrometry. Target pathways activated by CD55 were identified by RNA sequencing. RESULTS: CD55 localizes to the nucleus of a subset of OC specimens, ascites from chemoresistant patients, and enriched in chemoresistant OC cells. We determined that nuclear CD55 is glycosylated and derived from the cell surface pool of CD55. Nuclear localization is driven by a trafficking code containing the serine/threonine (S/T) domain of CD55. Nuclear CD55 is necessary for cisplatin resistance, stemness, and cell proliferation in OC cells. CD55 S/T domain is necessary for nuclear entry and inducing chemoresistance to cisplatin in both in vitro and in vivo models. Deletion of the CD55 S/T domain is sufficient to sensitize chemoresistant OC cells to cisplatin. In the nucleus, CD55 binds and attenuates the epigenetic regulator and tumor suppressor ZMYND8 with a parallel increase in H3K27 trimethylation and members of the Polycomb Repressive Complex 2. CONCLUSIONS: For the first time, we show CD55 localizes to the nucleus in OC and promotes CSC and chemoresistance. Our studies identify a therapeutic mechanism for treating platinum resistant ovarian cancer by blocking CD55 nuclear entry.

Cross-neutralizing antibody against emerging Omicron subvariants of SARS-CoV-2 in infection-naïve individuals with homologous BNT162b2 or BNT162b2(WT + BA.4/5) bivalent booster vaccination.

Since the emergence of SARS-CoV-2, different variants and subvariants successively emerged to dominate global virus circulation as a result of immune evasion, replication fitness or both. COVID-19 vaccines continue to be updated in response to the emergence of antigenically divergent viruses, the first being the bivalent RNA vaccines that encodes for both the Wuhan-like and Omicron BA.5 subvariant spike proteins. Repeated infections and vaccine breakthrough infections have led to complex immune landscapes in populations making it increasingly difficult to assess the intrinsic neutralizing antibody responses elicited by the vaccines. Hong Kong's intensive COVID-19 containment policy through 2020-2021 permitted us to identify sera from a small number of infection-naïve individuals who received 3 doses of the RNA BNT162b2 vaccine encoding the Wuhan-like spike (WT) and were boosted with a fourth dose of the WT vaccine or the bivalent WT and BA.4/5 spike (WT + BA.4/5). While neutralizing antibody to wild-type virus was comparable in both vaccine groups, BNT162b2 (WT + BA.4/BA.5) bivalent vaccine elicited significantly higher plaque neutralizing antibodies to Omicron subvariants BA.5, XBB.1.5, XBB.1.16, XBB.1.9.1, XBB.2.3.2, EG.5.1, HK.3, BA.2.86 and JN.1, compared to BNT162b2 monovalent vaccine. The single amino acid substitution that differentiates the spike of JN.1 from BA.2.86 resulted in a profound antigenic change.

Robotic living donor nephrectomy is associated with reduced post-operative opioid use compared to hand-assisted laparoscopic approach.

BACKGROUND: Robotic donor nephrectomy (RDN) has emerged as a safe alternative to laparoscopic donor nephrectomy (LDN). Having previously demonstrated comparable efficacy, this study aims to examine postoperative analgesia use (opioid and non-opioid) in the two groups. METHODS: We conducted a retrospective review of 300 living donor nephrectomies performed at our center, comparing 150 RDN's with a contemporary cohort of 150 hand-assisted LDN's. In addition to clinical and demographic information, data on postoperative inpatient opioid and non-opioid analgesia (from patient's arrival to the surgical floor after surgery till the time of discharge) was collected. Opioid dosages were standardized by conversion to morphine milligram equivalents (MME). All patients were managed post-operatively under a standardized ERAS pathway for living donor nephrectomy patients. RESULTS: There were no significant differences in donor age, gender, and BMI between RDN and LDN groups. Total post-operative opioid use (MME's) was significantly lower in RDN patients (RDN 27.1 vs. LDN 46.3; P < 0.0001). Breakdown of opioid use with post-operative (POD) day demonstrated significantly lower use in RDN group on POD1 (RDN 8.6 vs. LDN 17.0; P < 0.05), and POD2 (RDN 3.9 vs LDN 10; P < 0.05). RDN patients had a shorter post-operative length of stay (LOS) (RDN 1.69 days vs. LDN 1.98; P = 0.0003). There were no differences between groups in non-opioid medication use, complications, and readmission rates. CONCLUSION: RDN has comparable safety to hand-assist LDN and offers additional benefits of lower postoperative opioid requirement and a shorter hospital LOS.

Normothermic machine perfusion for liver transplantation: current state and future directions.

PURPOSE OF REVIEW: The number of patients on the liver transplant waitlist continues to grow and far exceeds the number of livers available for transplantation. Normothermic machine perfusion (NMP) allows for ex-vivo perfusion under physiologic conditions with the potential to significantly increase organ yield and expand the donor pool. RECENT FINDINGS: Several studies have found increased utilization of donation after cardiac death and extended criteria brain-dead donor livers with implementation of NMP, largely due to the ability to perform viability testing during machine perfusion. Recently, proposed viability criteria include lactate clearance, maintenance of perfusate pH more than 7.2, ALT less than 6000 u/l, evidence of glucose metabolism and bile production. Optimization of liver grafts during NMP is an active area of research and includes interventions for defatting steatotic livers, preventing ischemic cholangiopathy and rejection, and minimizing ischemia reperfusion injury. SUMMARY: NMP has resulted in increased organ utilization from marginal donors with acceptable outcomes. The added flexibility of prolonged organ storage times has the potential to improve time constraints and transplant logistics. Further research to determine ideal viability criteria and investigate ways to optimize marginal and otherwise nontransplantable liver grafts during NMP is warranted.

Downstaging Hepatocellular Carcinoma before Transplantation: Role of Immunotherapy Versus Locoregional Approaches.

Hepatocellular carcinoma (HCC) continues to be a leading cause of cancer-related death in the United States. With advances in locoregional therapy for unresectable HCC during the last 2 decades and the recent expansion of transplant criteria for HCC, as well as ongoing organ shortages, patients are spending more time on the waitlist, which has resulted in an increased usage of locoregional therapies. The plethora of molecularly targeted therapies and immune checkpoint inhibitors under investigation represent the new horizon of treatment of HCC not only in advanced stages but also potentially at every stage of diagnosis and management.

Primary Non-Function of Hepatic Allograft With Preexisting Microvesicular Steatosis/Foamy Degeneration and Mild Large-Droplet Macrovesicular Steatosis.

It has been established that more than mild large-droplet macrovesicular steatosis (LD-MAS) is associated with increased risk of graft non-function. In contrast, even severe small-droplet macrovesicular steatosis (SD-MAS) has been found to be less prognostically significant. It remains unclear if a donor liver with diffuse microvesicular steatosis is associated with an increased risk of graft dysfunction. A 56-year-old male with alcoholic cirrhosis was transplanted with a liver from a 42-year-old overweight male donor after brain death. The frozen section of the donor liver biopsy taken at harvest showed diffusely enlarged clear/foamy hepatocytes and mild LD-MAS (about 5-10% of total tissue). The reperfusion liver biopsy taken at time 0 of transplantation showed hemorrhage, pale and enlarged hepatocytes, and mild LD-MAS (about 10% of total tissue) with lipopeliosis. The graft became non-functional, and the patient was re-transplanted 24 h after the initial transplantation. Histologic examination of the failed liver allograft showed extensive hemorrhagic necrosis, neutrophilic inflammation, diffuse microvesicular steatosis, and large extracellular fat droplets (about 20% of total tissue). This case demonstrates that precautions are needed to avoid using livers with diffuse and severe microvesicular steatosis.

Predictive analytics for cardiovascular patient readmission and mortality: An explainable approach.

BACKGROUND: Cardiovascular patients experience high rates of adverse outcomes following discharge from hospital, which may be preventable through early identification and targeted action. This study aimed to investigate the effectiveness and explainability of machine learning algorithms in predicting unplanned readmission and death in cardiovascular patients at 30 days and 180 days from discharge. METHODS: Gradient boosting machines were trained and evaluated using data from hospital electronic medical records linked to hospital administrative and mortality data for 39,255 patients admitted to four hospitals in New South Wales, Australia between 2017 and 2021. Sociodemographic variables, admission history, and clinical information were used as potential predictors. The performance was compared to LASSO regression, as well as the HOSPITAL and LACE risk score indices. Important risk factors identified by the gradient-boosting machine model were explored using Shapley values. RESULTS: The models performed well, especially for the mortality outcomes. Area under the receiver operating characteristic curve values were 0.70 for readmission and 0.87-0.90 for mortality using the full gradient boosting machine algorithms. Among the top predictors for 30-day and 180-day readmission were increased red cell distribution width, old age (especially above 80 years), high measured troponin and urea levels, not being married or in a relationship, and low albumin levels. For mortality, these included increased red cell distribution width, old age (especially older than 70 years), high measured troponin and urea levels, high neutrophil and monocyte counts, and low eosinophil and lymphocyte counts. The Shapley values gave clear insight into the dynamics of decision-tree-based models. CONCLUSIONS: We demonstrated an explainable predictive algorithm to identify cardiovascular patients who are at high risk of readmission or death at discharge from the hospital and identified key risk factors.

nSEA: n-Node Subnetwork Enumeration Algorithm Identifies Lower Grade Glioma Subtypes with Altered Subnetworks and Distinct Prognostics.

Advances in molecular characterization have reshaped our understanding of low-grade glioma (LGG) subtypes, emphasizing the need for comprehensive classification beyond histology. Lever-aging this, we present a novel approach, network-based Subnetwork Enumeration, and Analysis (nSEA), to identify distinct LGG patient groups based on dysregulated molecular pathways. Using gene expression profiles from 516 patients and a protein-protein interaction network we generated 25 million sub-networks. Through our unsupervised bottom-up approach, we selected 92 subnetworks that categorized LGG patients into five groups. Notably, a new LGG patient group with a lack of mutations in EGFR, NF1, and PTEN emerged as a previously unidentified patient subgroup with unique clinical features and subnetwork states. Validation of the patient groups on an independent dataset demonstrated the robustness of our approach and revealed consistent survival traits across different patient populations. This study offers a comprehensive molecular classification of LGG, providing insights beyond traditional genetic markers. By integrating network analysis with patient clustering, we unveil a previously overlooked patient subgroup with potential implications for prognosis and treatment strategies. Our approach sheds light on the synergistic nature of driver genes and highlights the biological relevance of the identified subnetworks. With broad implications for glioma research, our findings pave the way for further investigations into the mechanistic underpinnings of LGG subtypes and their clinical relevance.Availability: Source code and supplementary data are available at https://github.com/bebeklab/nSEA.

Improving Pediatric Fellows' Feedback Skills and Confidence Through Objective Structured Examinations.

Background Medical trainees must learn how to provide effective feedback as an essential communication skill, yet few models exist for training and assessing these skills. Objective To develop an observed structured feedback examination (OSFE) to provide feedback training to pediatric fellows and assess changes in skills and self-reported confidence. Methods This educational study was conducted from 2019 to 2020 at an academic children's hospital. Our team developed the OSFE and trained standardized feedback recipients and faculty. Fellows completed baseline self-assessments (31 items) on prior exposure to feedback training, application of skills, and confidence. They then participated in the OSFE, giving feedback to a standardized recipient using a standardized scenario, and were scored by faculty and recipients using a 15-item checklist for performance. Next, fellows participated in feedback training and received individualized feedback, after which they repeated the OSFE and confidence self-assessment. Three months later, fellows completed self-assessments on confidence and application of skills and another OSFE to assess retention. Descriptive statistics and signed rank sum test were used for analysis. Results Of 60 eligible fellows, 19 participated (32%), with 100% follow-up. After training and individualized feedback, all fellows improved feedback skills as measured by OSFE performance (mean change +0.89). All items, measured on a 5-point Likert scale, were sustained 3 months later (mean change +0.92). All fellows reported improved confidence in feedback knowledge (mean change +2.07 post, +1.67 3 months post). Conclusions Feedback training using simulation and individualized feedback moderately improved fellows' performance, confidence, and 3-month retention of feedback skills.

Long non-coding RNA lung cancer-associated transcript-1 promotes glioblastoma progression by enhancing Hypoxia-inducible factor 1 alpha activity.

BACKGROUND: Hypoxia is associated with poor prognosis in many cancers including glioblastoma (GBM). Glioma stem-like cells (GSCs) often reside in hypoxic regions and serve as reservoirs for disease progression. Long non-coding RNAs (lncRNAs) have been implicated in GBM. However, the lncRNAs that modulate GSC adaptations to hypoxia are poorly understood. Identification of these lncRNAs may provide new therapeutic strategies to target GSCs under hypoxia. METHODS: lncRNAs induced by hypoxia in GSCs were identified by RNA-seq. Lung cancer-associated transcript-1 (LUCAT1) expression was assessed by qPCR, RNA-seq, Northern blot, single molecule FISH in GSCs, and interrogated in IvyGAP, The Cancer Genome Atlas, and CGGA databases. LUCAT1 was depleted by shRNA, CRISPR/Cas9, and CRISPR/Cas13d. RNA-seq, Western blot, immunohistochemistry, co-IP, ChIP, ChIP-seq, RNA immunoprecipitation, and proximity ligation assay were performed to investigate mechanisms of action of LUCAT1. GSC viability, limiting dilution assay, and tumorigenic potential in orthotopic GBM xenograft models were performed to assess the functional consequences of depleting LUCAT1. RESULTS: A new isoform of Lucat1 is induced by Hypoxia inducible factor 1 alpha (HIF1α) and Nuclear factor erythroid 2-related factor 2 (NRF2) in GSCs under hypoxia. LUCAT1 is highly expressed in hypoxic regions in GBM. Mechanistically, LUCAT1 formed a complex with HIF1α and its co-activator CBP to regulate HIF1α target gene expression and GSC adaptation to hypoxia. Depletion of LUCAT1 impaired GSC self-renewal. Silencing LUCAT1 decreased tumor growth and prolonged mouse survival in GBM xenograft models. CONCLUSIONS: A HIF1α-LUCAT1 axis forms a positive feedback loop to amplify HIF1α signaling in GSCs under hypoxia. LUCAT1 promotes GSC self-renewal and GBM tumor growth. LUCAT1 is a potential therapeutic target in GBM.

Phase I trial of dose escalation for preoperative stereotactic radiosurgery for patients with large brain metastases.

BACKGROUND: Single session stereotactic radiosurgery (SRS) or surgical resection alone for brain metastases larger than 2 cm results in unsatisfactory local control. We conducted a phase I trial for brain metastases(>2cm) to determine the safety of preoperative SRS at escalating doses. METHODS: Radiosurgery dose was escalated at 3 Gy increments for 3 cohorts based on maximum tumor dimension starting at: 18 Gy for >2-3 cm, 15 Gy for >3-4 cm, and 12 Gy for >4-6 cm. Dose limiting toxicity (DLT) was defined as grade III or greater acute toxicity. RESULTS: A total of 35 patients/36 lesions were enrolled. For tumor size >2-3 cm, patients were enrolled up to the second dose level (21 Gy); for >3-4 cm and >4-6 cm cohorts the third dose level (21 Gy and 18 Gy, respectively) was reached. There were 2 DLTs in the >3-4 cm arm at 21Gy. The maximum tolerated dose (MTD) of SRS for >2-3 cm was not reached; and was 18 Gy for both >3-4 cm arm and >4-6 cm arm. With a median follow-up of 64.0 months, the 6- and 12-month local control rates were 85.9% and 76.6%, respectively. One patient developed grade 3 radiation necrosis at 5 months. The 2-year rate of leptomeningeal disease (LMD) was 0%. CONCLUSION: Preoperative SRS with dose escalation followed by surgical resection for brain metastases greater than 2 cm in size demonstrates acceptable acute toxicity. The phase II portion of the trial will be conducted at the maximum tolerated SRS doses.

Robotic performance metrics model fellow proficiency in living donor nephrectomy.

We investigated the use of robotic objective performance metrics (OPM) to predict number of cases to proficiency and independence among abdominal transplant fellows performing robot-assisted donor nephrectomy (RDN). 101 RDNs were performed by 5 transplant fellows from September 2020 to October 2023. OPM included fellow percent active control time (%ACT) and handoff counts (HC). Proficiency was defined as ACT ≥ 80% and HC ≤ 2, and independence as ACT ≥ 99% and HC ≤ 1. Case number was significantly associated with increasing fellow %ACT, with proficiency estimated at 14 cases and independence at 32 cases (R2 = 0.56, p < 0.001). Similarly, case number was significantly associated with decreasing HC, with proficiency at 18 cases and independence at 33 cases (R2 = 0.29, p < 0.001). Case number was not associated with total active console time (p = 0.91). Patient demographics, operative characteristics, and outcomes were not associated with OPM, except for donor estimated blood loss (EBL), which positively correlated with HC. Abdominal transplant fellows demonstrated proficiency at 14-18 cases and independence at 32-33 cases. Total active console time remained unchanged, suggesting that increasing fellow autonomy does not impede operative efficiency. These findings may serve as a benchmark for training abdominal transplant surgery fellows independently and safely in RDN.

Cross-fellowship Inter-institutional Exchange: Answering the Call for Hepatopancreatobiliary Training Standardization.

OBJECTIVE: General surgery trainees interested in performing hepatopancreatobiliary (HPB) surgery can choose from multiple fellowship pathways, namely HPB, surgical oncology (SO), and abdominal transplant-HPB (TXP-HPB). Although focused on similar operations, each program offers distinct clinical and technical emphases. DESIGN: An annual inter-institutional exchange between TXP-HPB and SO fellowships, starting in 2014. SETTING AND PARTICIPANTS: TXP-HPB fellows from Washington University in St. Louis (WUSTL) and SO fellows from Memorial Sloan Kettering Cancer Center (MSKCC). RESULTS: About 14 fellows have participated in the exchange so far, 13 of whom responded to our survey. At MSKCC, TXP-HPB fellows performed a median of 24 cases, including 6 major pancreatic resections, 3 major hepatectomies, 4 hepatic artery infusion pump insertions, and 1 major biliary case. At WUSTL, SO fellows performed a median of 16 cases, including 5 liver transplants, 2 major pancreatic resections, 2 major hepatectomies, and 2 major biliary cases. About 92.3% of respondents stated they would repeat the rotation, with SO fellows emphasizing the exposure to vascular anastomoses and transplant-HPB fellows appreciating the oncologic focus. CONCLUSIONS: A monthlong inter-institutional exchange offers a unique opportunity to standardize and improve HPB education.