Advancing the care of individuals with cancer through innovation & technology: Proceedings from the cardiology oncology innovation summit 2020 and 2021.

As cancer therapies increase in effectiveness and patients' life expectancies improve, balancing oncologic efficacy while reducing acute and long-term cardiovascular toxicities has become of paramount importance. To address this pressing need, the Cardiology Oncology Innovation Network (COIN) was formed to bring together domain experts with the overarching goal of collaboratively investigating, applying, and educating widely on various forms of innovation to improve the quality of life and cardiovascular healthcare of patients undergoing and surviving cancer therapies. The COIN mission pillars of innovation, collaboration, and education have been implemented with cross-collaboration among academic institutions, private and public establishments, and industry and technology companies. In this report, we summarize proceedings from the first two annual COIN summits (inaugural in 2020 and subsequent in 2021) including educational sessions on technological innovations for establishing best practices and aligning resources. Herein, we highlight emerging areas for innovation and defining unmet needs to further improve the outcome for cancer patients and survivors of all ages. Additionally, we provide actionable suggestions for advancing innovation, collaboration, and education in cardio-oncology in the digital era.

Structure, sequon recognition and mechanism of tryptophan C-mannosyltransferase.

C-linked glycosylation is essential for the trafficking, folding and function of secretory and transmembrane proteins involved in cellular communication processes. The tryptophan C-mannosyltransferase (CMT) enzymes that install the modification attach a mannose to the first tryptophan of WxxW/C sequons in nascent polypeptide chains by an unknown mechanism. Here, we report cryogenic-electron microscopy structures of Caenorhabditis elegans CMT in four key states: apo, acceptor peptide-bound, donor-substrate analog-bound and as a trapped ternary complex with both peptide and a donor-substrate mimic bound. The structures indicate how the C-mannosylation sequon is recognized by this CMT and its paralogs, and how sequon binding triggers conformational activation of the donor substrate: a process relevant to all glycosyltransferase C superfamily enzymes. Our structural data further indicate that the CMTs adopt an unprecedented electrophilic aromatic substitution mechanism to enable the C-glycosylation of proteins. These results afford opportunities for understanding human disease and therapeutic targeting of specific CMT paralogs.

VA-ECMO-assisted aspiration thrombectomy in a patient presenting with acute massive PE with absolute contraindications to thrombolytics.

Massive pulmonary embolism (PE) is a life-threatening complication of major surgery with a mortality rate up to 50%. First-line therapy for massive PE is systemic thrombolytics, but surgical patients are at high bleeding risk with absolute contraindications. As surgical thrombectomy carries a high burden of morbidity and mortality, endovascular interventions are becoming more common in these clinical scenarios. We report a case of a neurosurgical patient whose postoperative course was complicated by massive PE and subsequent cardiac arrest that required emergent venoarterial extracorporeal membrane oxygenation, followed by aspiration thrombectomy with the Inari FlowTriever Device (Inari Medical). The patient had immediate hemodynamic improvement with eventual recovery to baseline functional status.

Cardiovascular Imaging in Cardio-Oncology: The Role of Echocardiography and Cardiac MRI in Modern Cardio-Oncology.

Cardiovascular (CV) events are an increasingly common limitation of effective anticancer therapy. Over the last decade imaging has become essential to patients receiving contemporary cancer therapy. Herein we discuss the current state of CV imaging in cardio-oncology. We also provide a practical apparatus for the use of imaging in everyday cardiovascular care of oncology patients to improve outcomes for those at risk for cardiotoxicity, or with established cardiovascular disease. Finally, we consider future directions in the field given the wave of new anticancer therapies.

Critical role for isoprenoids in apicoplast biogenesis by malaria parasites.

Isopentenyl pyrophosphate (IPP) is an essential metabolic output of the apicoplast organelle in Plasmodium falciparum malaria parasites and is required for prenylation-dependent vesicular trafficking and other cellular processes. We have elucidated a critical and previously uncharacterized role for IPP in apicoplast biogenesis. Inhibiting IPP synthesis blocks apicoplast elongation and inheritance by daughter merozoites, and apicoplast biogenesis is rescued by exogenous IPP and polyprenols. Knockout of the only known isoprenoid-dependent apicoplast pathway, tRNA prenylation by MiaA, has no effect on blood-stage parasites and thus cannot explain apicoplast reliance on IPP. However, we have localized an annotated polyprenyl synthase (PPS) to the apicoplast. PPS knockdown is lethal to parasites, rescued by IPP and long- (C50) but not short-chain (≤C20) prenyl alcohols, and blocks apicoplast biogenesis, thus explaining apicoplast dependence on isoprenoid synthesis. We hypothesize that PPS synthesizes long-chain polyprenols critical for apicoplast membrane fluidity and biogenesis. This work critically expands the paradigm for isoprenoid utilization in malaria parasites and identifies a novel essential branch of apicoplast metabolism suitable for therapeutic targeting.

Case report of a coronary artery-right ventricular fistula following repeat endomyocardial biopsies in a heart transplant patient.

BACKGROUND: Endomyocardial biopsy (EMB) remains the gold standard for cellular rejection surveillance in heart transplant recipients. Coronary artery fistula formation is a rare late and potentially catastrophic complication of repeated endomyocardial biopsies, without contemporary evidence on incidence or management. CASE SUMMARY: A 47-year-old male was found to have a fistula between his right ventricle and his left anterior descending artery on an angiogram that was performed as a part of regular screening of coronary allograft vasculopathy. Given the low shunt fraction, asymptomatic nature, and lack of guidelines on definitive management, the patient is undergoing conservative management with regular surveillance. DISCUSSION: Coronary artery fistulas were once thought to be rare complications of repeated EMB, but the true prevalence is likely to be higher than previously believed. Ideal treatment and monitoring is unknown given the relative rarity of the condition.

Yeast- and antibody-based tools for studying tryptophan C-mannosylation.

Tryptophan C-mannosylation is an unusual co-translational protein modification performed by metazoans and apicomplexan protists. The prevalence and biological functions of this modification are poorly understood, with progress in the field hampered by a dearth of convenient tools for installing and detecting the modification. Here, we engineer a yeast system to produce a diverse array of proteins with and without tryptophan C-mannosylation and interrogate the modification's influence on protein stability and function. This system also enabled mutagenesis studies to identify residues of the glycosyltransferase and its protein substrates that are crucial for catalysis. The collection of modified proteins accrued during this work facilitated the generation and thorough characterization of monoclonal antibodies against tryptophan C-mannosylation. These antibodies empowered proteomic analyses of the brain C-glycome by enriching for peptides possessing tryptophan C-mannosylation. This study revealed many new modification sites on proteins throughout the secretory pathway with both conventional and non-canonical consensus sequences.

Clinical efficacy of direct-acting antiviral therapy for recurrent hepatitis C virus infection after liver transplantation in patients with hepatocellular carcinoma.

BACKGROUND: Recurrent hepatitis C virus (HCV) infection of transplanted liver allografts is universal in patients with detectable HCV viremia at the time of transplantation. Direct-acting antiviral (DAA) therapy has been adopted as the standard of care for recurrent HCV infection in the post-transplant setting. However, there are insufficient data regarding its efficacy in liver transplant (LT) recipients with a history of hepatocellular carcinoma (HCC), and the risk of HCC recurrence after DAA therapy is unknown. AIM: To demonstrate predictors of DAA treatment failure and HCC recurrence in LT recipients. METHODS: A total of 106 LT recipients given DAAs for recurrent HCV infection from 2015 to 2019 were identified (68 with and 38 without HCC). Descriptive statistics and logistic regression models were used to estimate the multivariate odds ratios and respective 95% confidence intervals for predictors of treatment failure and HCC recurrence. RESULTS: Six patients (6%) experienced DAA therapy failure post-LT and 100 (94%) had a sustained virologic response at follow-up week 12. A high alanine transaminase level > 35 U/L at treatment week 4 was a significant predictor of treatment failure. Relapse to pre-LT DAA therapy is a predictor of post-LT HCC recurrence, P = 0.04. DAA relapse post-LT was also associated with post-transplantation HCC recurrence, P = 0.05. CONCLUSION: DAAs are effective and safe in the treatment of recurrent HCV infection in LT recipients with history of HCC. Relapse to pre- and post-LT DAA therapy is associated with post-transplantation HCC recurrence.

Structural basis of substrate recognition and catalysis by fucosyltransferase 8.

Fucosylation of the innermost GlcNAc of N-glycans by fucosyltransferase 8 (FUT8) is an important step in the maturation of complex and hybrid N-glycans. This simple modification can dramatically affect the activities and half-lives of glycoproteins, effects that are relevant to understanding the invasiveness of some cancers, development of mAb therapeutics, and the etiology of a congenital glycosylation disorder. The acceptor substrate preferences of FUT8 are well-characterized and provide a framework for understanding N-glycan maturation in the Golgi; however, the structural basis of these substrate preferences and the mechanism through which catalysis is achieved remain unknown. Here we describe several structures of mouse and human FUT8 in the apo state and in complex with GDP, a mimic of the donor substrate, and with a glycopeptide acceptor substrate at 1.80-2.50 Å resolution. These structures provide insights into a unique conformational change associated with donor substrate binding, common strategies employed by fucosyltransferases to coordinate GDP, features that define acceptor substrate preferences, and a likely mechanism for enzyme catalysis. Together with molecular dynamics simulations, the structures also revealed how FUT8 dimerization plays an important role in defining the acceptor substrate-binding site. Collectively, this information significantly builds on our understanding of the core fucosylation process.

Glutamine via α-ketoglutarate dehydrogenase provides succinyl-CoA for heme synthesis during erythropoiesis.

During erythroid differentiation, the erythron must remodel its protein constituents so that the mature red cell contains hemoglobin as the chief cytoplasmic protein component. For this, ∼109 molecules of heme must be synthesized, consuming 1010 molecules of succinyl-CoA. It has long been assumed that the source of succinyl-coenzyme A (CoA) for heme synthesis in all cell types is the tricarboxylic acid (TCA) cycle. Based upon the observation that 1 subunit of succinyl-CoA synthetase (SCS) physically interacts with the first enzyme of heme synthesis (5-aminolevulinate synthase 2, ALAS2) in erythroid cells, it has been posited that succinyl-CoA for ALA synthesis is provided by the adenosine triphosphate-dependent reverse SCS reaction. We have now demonstrated that this is not the manner by which developing erythroid cells provide succinyl-CoA for ALA synthesis. Instead, during late stages of erythropoiesis, cellular metabolism is remodeled so that glutamine is the precursor for ALA following deamination to α-ketoglutarate and conversion to succinyl-CoA by α-ketoglutarate dehydrogenase (KDH) without equilibration or passage through the TCA cycle. This may be facilitated by a direct interaction between ALAS2 and KDH. Succinate is not an effective precursor for heme, indicating that the SCS reverse reaction does not play a role in providing succinyl-CoA for heme synthesis. Inhibition of succinate dehydrogenase by itaconate, which has been shown in macrophages to dramatically increase the concentration of intracellular succinate, does not stimulate heme synthesis as might be anticipated, but actually inhibits hemoglobinization during late erythropoiesis.

Synthesis and use of 6,6,6-trifluoro-L-fucose to block core-fucosylation in hybridoma cell lines.

Many monoclonal antibodies (mAbs) used in cancer immunotherapy mediate tumour cell lysis by recruiting natural killer (NK) cells; a phenomenon known as antibody-dependent cellular cytotoxicity (ADCC). Eliminating core-fucose from the N-glycans of a mAb enhances its capacity to induce ADCC. As such, inhibitors of fucosylation are highly desirable for the production of mAbs for research and therapeutic use. Herein, we describe a simple synthesis of 6,6,6-trifluoro-l-fucose (F3Fuc), a metabolic inhibitor of fucosylation, and demonstrate the utility of this molecule in the production of low-fucose mAbs from murine hybridoma cell lines.

Orthotopic liver transplantation for Sensenbrenner syndrome.

Sensenbrenner syndrome, or cranioectodermal dysplasia, is a rare heterogeneic autosomal recessive disorder, affecting ~1 of 1 000 000 live births. The syndrome usually manifests within the first year of life and can present with progressive liver and renal involvement. For all Sensenbrenner patients, renal and liver diseases are the main contributors of morbidity and mortality. In this report, we present the case of a 7-year-old boy with congenital liver disease progressing to liver failure secondary to Sensenbrenner syndrome. For this patient, evidence of liver dysfunction was evident from 2 months of age and progressed to frank cirrhosis and severe portal hypertension with multiple episodes of life-threatening variceal bleeding by age 6. This report illustrates the capability of orthotopic liver transplantation as a viable therapy for those pediatric patients suffering from severe liver failure secondary to a congenital ciliopathy, such as Sensenbrenner syndrome. In fact, early emphasis should be placed on the renal and liver involvement associated with Sensenbrenner syndrome with particular consideration for early referral for transplantation in cases with severe disease. Although the condition is rare, clinicians should be aware of it and its association with fatal liver disease to facilitate appropriate evaluation and referral.

Chronic obstructive pulmonary disease as a risk factor for ventricular arrhythmias independent of left ventricular function.

BACKGROUND: The association between chronic obstructive pulmonary disease (COPD) and sudden cardiac death has not been fully elucidated. OBJECTIVE: The purpose of this study was to investigate whether decreased left ventricular ejection fraction (LVEF) can explain the increased rate of ventricular tachycardia (VT) in COPD. METHODS: This retrospective study included consecutive adult patients who underwent pulmonary function testing (PFT), Holter monitoring, and transthoracic echocardiography. COPD was correlated with the frequency of VT in a multivariate analysis that adjusted for known confounders including LVEF. Long-term all-cause mortality of patients with COPD and VT was examined. RESULTS: Of the 6351 patients included in this study (age 66 ± 15 years; 48% woman; 92% Caucasian, LVEF 59% ± 12%), 2800 (44%) had PFT indicative of COPD. VT was nearly twice as likely to occur during Holter monitoring in COPD patients (13% vs 23%; P <.001), and the severity of COPD correlated with the risk of VT (21% vs 28% vs 37% for mild-moderate, severe, and very severe COPD; P <.001). COPD and VT remained independently associated (P <.001) even after adjusting for LVEF, demographics, and comorbidities (age, sex, body mass index, hypertension, chronic kidney disease, coronary artery disease, cancer history, diabetes mellitus). COPD was associated with all-cause mortality independently of LVEF (P <.001). CONCLUSION: COPD patients are at higher risk for VT and mortality. This may not be fully attributed to the confounding effect of systolic heart failure measured by LVEF. Further studies are needed to explore the mechanistic interactions between VT and COPD in order to determine whether antiarrhythmic strategies would apply especially to patients with severe COPD.

REST/NRSF Knockdown Alters Survival, Lineage Differentiation and Signaling in Human Embryonic Stem Cells.

REST (RE1 silencing transcription factor), also known as NRSF (neuron-restrictive silencer factor), is a well-known transcriptional repressor of neural genes in non-neural tissues and stem cells. Dysregulation of REST activity is thought to play a role in diverse diseases including epilepsy, cancer, Down's syndrome and Huntington's disease. The role of REST/NRSF in control of human embryonic stem cell (hESC) fate has never been examined. To evaluate the role of REST in hESCs we developed an inducible REST knockdown system and examined both growth and differentiation over short and long term culture. Interestingly, we have found that altering REST levels in multiple hESC lines does not result in loss of self-renewal but instead leads to increased survival. During differentiation, REST knockdown resulted in increased MAPK/ERK and WNT signaling and increased expression of mesendoderm differentiation markers. Therefore we have uncovered a new role for REST in regulation of growth and early differentiation decisions in human embryonic stem cells.

Primary clear cell carcinoma of the rete testis: 1st report.

Primary tumours of the rete testis, either benign or malignant, are very rare. Such lesions require careful scrutiny including immunohistochemical analysis to exclude malignant lesions such as mesothelioma or papillary serous carcinoma. To the best of our knowledge this is the first report of a primary clear cell carcinoma of the rete testis. The possibility of a primary renal cell carcinoma or other primary site with metastatic spread to rete testis was excluded by thorough clinical and radiological work-up.

Consequence of the tumor-associated conversion to cyclin D1b.

Clinical evidence suggests that cyclin D1b, a variant of cyclin D1, is associated with tumor progression and poor outcome. However, the underlying molecular basis was unknown. Here, novel models were created to generate a genetic switch from cyclin D1 to cyclin D1b. Extensive analyses uncovered overlapping but non-redundant functions of cyclin D1b compared to cyclin D1 on developmental phenotypes, and illustrated the importance of the transcriptional regulatory functions of cyclin D1b in vivo. Data obtained identify cyclin D1b as an oncogene, wherein cyclin D1b expression under the endogenous promoter induced cellular transformation and further cooperated with known oncogenes to promote tumor growth in vivo. Further molecular interrogation uncovered unexpected links between cyclin D1b and the DNA damage/PARP1 regulatory networks, which could be exploited to suppress cyclin D1b-driven tumors. Collectively, these data are the first to define the consequence of cyclin D1b expression on normal cellular function, present evidence for cyclin D1b as an oncogene, and provide pre-clinical evidence of effective methods to thwart growth of cells dependent upon this oncogenic variant.

Radical prostatectomy in the presence of ongoing refractory ESBL Escherichia coli bacterial prostatitis.

A 44-year-old Indian national with a prostate-specific antigen of 5.4 ng/mL underwent 12-core transrectal ultrasound-guided prostate biopsies. Following this, he had three hospital admissions with severe urosepsis secondary to extended spectrum ß lactamase (ESBL) producing Escherichia coli. He had recurrent sepsis immediately after discontinuation of intravenous meropenem to which the ESBL was sensitive. He proceeded to radical prostatectomy for intermediate-high risk Gleason 7 prostate cancer, while still on intravenous meropenem, 2 months after his biopsy. His prostatectomy involved a difficult dissection due to inflammatory changes and fibrosis after multiple septic episodes. He had complete resolution of infection after surgery with discontinuation of antibiotics on the third postoperative day, without any recurrence of sepsis.

Surgical management of metastatic long bone fractures: principles and techniques.

Management of metastatic long bone fractures requires identification of the lesion and the use of sound fracture fixation principles to relieve pain and restore function. The treating surgeon must understand the principles of pathologic fracture fixation before initiating treatment. Because these fractures occur in the context of a progressive systemic disease, management typically involves a multidisciplinary approach. When considering surgical stabilization of these fractures, the abnormal (or absent) healing environment associated with diseased bone and the overall condition of the patient must be taken into account. The goal of surgery is to obtain a rigid mechanical construct, which allows for early mobility and weight bearing. This can be achieved using internal fixation with polymethyl methacrylate cement or segmental resection and joint reconstruction. Prosthetic joint arthroplasty is a more reliable means of fracture management when insufficient bone is present for fixation. Prophylactic stabilization of impending pathologic fractures can reduce the morbidity associated with metastatic lesions.

Estimation of clinically significant prostate volumes by digital rectal examination: a comparative prospective study.

INTRODUCTION: Reliable quantification of prostate volume is important to correctly select patients with benign prostatic hyperplasia (BPH) most likely to benefit from medical therapy [e.g. 5 alpha-reductase inhibitors (5-ARIs)] and in selecting appropriate surgical approach. We aim to determine the reliability of digital rectal examination (DRE) in estimation of prostate volume which may be helpful in patient selection for 5-ARIs therapy. MATERIALS AND METHODS: Patients requiring transrectal ultrasound (TRUS) guided prostate biopsy were recruited in this prospective study. DRE was performed twice for each patient. Clinicians categorized prostate volume on DRE into small, medium and large, and estimated prostate volume. Volume estimated by DRE at the first examination was intentionally unavailable at second DRE. TRUS volumes were measured using 2101 Falcon ultrasound machine. RESULTS: Comparative analysis of prostate volume (n = 248) by DRE and TRUS was performed. There was no significant difference between DRE-estimated prostate volume at the first and second examinations (p = 0.8). DRE-estimated volumes for prostates categorized as small, medium or large were underestimated in 59%, 58% and 53% of patients respectively. However, for clinical relevant volumes (> 30 cc), 94.5% patients were accurately estimated on DRE. CONCLUSIONS: We have shown that DRE had positive predictive value of 94% in identifying prostate above 30 cc. Hence, when considering treatment with 5-ARIs, DRE may be sufficient to identify suitable patients for 5-ARIs therapy. However, for prostate volumes between 25 cc-30 cc and above 80 cc, TRUS may be required.