RUNX3 Controls a Metastatic Switch in Pancreatic Ductal Adenocarcinoma.

For the majority of patients with pancreas cancer, the high metastatic proclivity is life limiting. Some patients, however, present with and succumb to locally destructive disease. A molecular understanding of these distinct disease manifestations can critically inform patient management. Using genetically engineered mouse models, we show that heterozygous mutation of Dpc4/Smad4 attenuates the metastatic potential of Kras(G12D/+);Trp53(R172H/+) pancreatic ductal adenocarcinomas while increasing their proliferation. Subsequent loss of heterozygosity of Dpc4 restores metastatic competency while further unleashing proliferation, creating a highly lethal combination. Expression levels of Runx3 respond to and combine with Dpc4 status to coordinately regulate the balance between cancer cell division and dissemination. Thus, Runx3 serves as both a tumor suppressor and promoter in slowing proliferation while orchestrating a metastatic program to stimulate cell migration, invasion, and secretion of proteins that favor distant colonization. These findings suggest a model to anticipate likely disease behaviors in patients and tailor treatment strategies accordingly.

Progress in the Management of Pancreatic Neuroendocrine Tumors.

Pancreatic neuroendocrine tumors (PNETs) are a heterogeneous and orphan group of neoplasms that vary in their histology, clinical features, prognosis, and management. The treatment of PNETs is highly dependent on the stage at presentation, tumor grade and differentiation, presence of symptoms from hormonal overproduction or from local growth, tumor burden, and rate of progression. The US Food and Drug Administration has recently approved many novel treatments, which have altered decision making and positively impacted the care and prognosis of these patients. In this review, we focus on the significant progress made in the management of PNETs over the past decade, as well as the active areas of research.

Peroxisomal support of mitochondrial respiratory efficiency promotes ER stress survival.

Endoplasmic reticulum stress (ERS) occurs when cellular demand for protein folding exceeds the capacity of the organelle. Adaptation and cell survival in response to ERS requires a critical contribution by mitochondria and peroxisomes. During ERS responses, mitochondrial respiration increases to ameliorate reactive oxygen species (ROS) accumulation. We now show in yeast that peroxisome abundance also increases to promote an adaptive response. In pox1Δ cells, which are defective in peroxisomal ß-oxidation of fatty acids, the respiratory response to ERS is impaired and ROS accrues. However, the respiratory response to ERS is rescued and ROS production is mitigated in pox1Δ cells overexpressing Mpc1, the mitochondrial pyruvate carrier that provides another source of acetyl CoA to fuel the tricarboxylic acid cycle and oxidative phosphorylation. Using proteomics, select mitochondrial proteins were identified that undergo upregulation upon ERS to remodel the respiratory machinery. The abundance of several peroxisome-based proteins was also increased, corroborating the role of peroxisomes in ERS adaptation. Finally, ERS stimulates assembly of respiratory complexes into higher-order supercomplexes, underlying increased electron transfer efficiency. Our results highlight peroxisomal and mitochondrial support for ERS adaptation to favor cell survival.

Electrophoresis of a dielectric droplet with constant surface charge density.

Electrophoresis of a dielectric fluid droplet with constant surface charge density is investigated theoretically in this study. A pseudo-spectral method based on Chebyshev polynomials is adopted to solve the governing electrokinetic equations. It is found, among other things, that the larger the electrolyte strength in the ambient solution is, the slower the droplet moves in general. This is due to the strong screening effect of the large amount of indifferent counterions in the neighborhood of the droplet, with no reinforcement of potential-determining ions adsorbing to the droplet surface. The droplet comes to a complete halt eventually. Critical points are discovered for highly charged droplets, at which the droplet surface becomes immobile and the interior fluid stops recirculating. The droplet moves like a rigid particle with constant mobility regardless of its viscosity, a situation referred to as the "solidification phenomenon." The deadlock between the spinning motions on the charged droplet surface induced by the electric driving force and the hydrodynamic driving force respectively is responsible for this peculiar phenomenon. This is also observed for a dielectric droplet with constant surface electric potential. We demonstrate here that it occurs in the constant surface charge density situation as well.

Quality-adjusted survival in women with gynecologic malignancies receiving IMRT after surgery: A Ppatient Rreported Ooutcome study of NRG oncology's RTOG 1203.

INTRODUCTION: NRG/RTOG 1203 compared 3-D conformal radiotherapy (3D CRT) to intensity-modulated radiotherapy (IMRT) in patients with endometrial or cervical cancer requiring post-operative radiotherapy after hysterectomy. The purpose of this study was to report the first quality-adjusted survival analysis comparing the two treatments. METHODS: NRG/RTOG 1203 randomized patients having undergone hysterectomy to either 3DCRT or IMRT. Stratification factors included RT dose, chemotherapy, and disease site. The EQ-5D, both index and visual analog scale (VAS), were obtained at baseline, 5 weeks after the start of RT, 4-6 weeks post RT and 1 and 3-years post RT. EQ-5D index and VAS scores along with quality-adjusted survival (QAS) were compared between treatment arms using the t-test at a two-sided significance level of 0.05. RESULTS: NRG/RTOG 1203 enrolled 289 patients of which 236 consented to participate in the patient reported outcome (PRO) assessments. QAS was higher in women treated with IMRT, 1374 vs 1333 days (p = 0.5) compared to patients treated with 3DCRT, but this difference was not statistically different. Patients treated with IMRT had less of a decline in VAS score 5 weeks post RT, -5.04, compared to patients treated with 3DCRT, -7.48, although not statistically significant (p = 0.38). CONCLUSION: This is the first report of the use of the EQ-5D comparing two radiotherapy techniques in the treatment of gynecologic malignancies after surgery. While there were no significant differences in QAS and VAS scores between patients who received IMRT vs. 3DCRT, RTOG 1203 was not powered to show statistical differences in these secondary endpoints.

Diffusiophoresis of a Weakly Charged Liquid Metal Droplet.

Diffusiophoresis of a weakly charged liquid metal droplet (LMD) is investigated theoretically, motivated by its potential application in drug delivery. A general analytical formula valid for weakly charged condition is adopted to explore the droplet phoretic behavior. We determined that a liquid metal droplet, which is a special category of the conducting droplet in general, always moves up along the chemical gradient in sole chemiphoresis, contrary to a dielectric droplet where the droplet tends to move down the chemical gradient most of the time. This suggests a therapeutic nanomedicine such as a gallium LMD is inherently superior to a corresponding dielectric liposome droplet in drug delivery in terms of self-guiding to its desired destination. The droplet moving direction can still be manipulated via the polarity dependence; however, there should be an induced diffusion potential present in the electrolyte solution under consideration, which spontaneously generates an extra electrophoresis component. Moreover, the smaller the conducting liquid metal droplet is, the faster it moves in general, which means a smaller LMD nanomedicine is preferred. These findings demonstrate the superior features of an LMD nanomedicine in drug delivery.

Retrograde signaling mediates an adaptive survival response to endoplasmic reticulum stress in Saccharomyces cerevisiae.

One major cause of endoplasmic reticulum (ER) stress is homeostatic imbalance between biosynthetic protein folding and protein folding capacity. Cells utilize mechanisms such as the unfolded protein response (UPR) to cope with ER stress. Nevertheless, when ER stress is prolonged or severe, cell death may occur, accompanied by production of mitochondrial reactive oxygen species (ROS). Using a yeast model (Saccharomyces cerevisiae), we describe an innate, adaptive response to ER stress to increase select mitochondrial proteins, O2 consumption and cell survival. The mitochondrial response allows cells to resist additional ER stress. The ER stress-induced mitochondrial response is mediated by activation of retrograde (RTG) signaling to enhance anapleurotic reactions of the tricarboxylic acid cycle. Mitochondrial response to ER stress is accompanied by inactivation of the conserved TORC1 pathway, and activation of Snf1/AMPK, the conserved energy sensor and regulator of metabolism. Our results provide new insight into the role of respiration in cell survival in the face of ER stress, and should help in developing therapeutic strategies to limit cell death in disorders linked to ER stress.This article has an associated First Person interview with the first author of the paper.

BSAC Vanguard Series: Artificial intelligence and antibiotic stewardship.

Antimicrobial stewardship is a key facet in preventing antimicrobial resistance but can be difficult to put into practice. Frontline providers are faced with the unknowns of pending culture data plus the urgency of appropriate antibiotic choice to prevent sepsis-related mortality; this often leads to broad-spectrum antibiotic prescribing. Currently available resources lack a customized approach to individual patients. Artificial intelligence (AI) focused on antimicrobial stewardship may create a unique opportunity to provide individualized, real-time recommendations to providers on appropriate, but narrower spectrum, antibiotic options. We envision that, with further advances in AI, personalized clinical decision support tools to optimize antibiotic prescribing could be available within the next decade.

Dynamics of living cells in a cytomorphological state space.

Cells are nonequilibrium systems that exchange matter and energy with the environment to sustain their metabolic needs. The nonequilibrium nature of this system presents considerable challenges to developing a general theory describing its behavior; however, when studied at appropriate spatiotemporal scales, the behavior of ensembles of nonequilibrium systems can resemble that of a system at equilibrium. Here we apply this principle to a population of cells within a cytomorphological state space and demonstrate that cellular transition dynamics within this space can be described using equilibrium formalisms. We use this framework to map the effective energy landscape underlying the cytomorphological state space of a population of mouse embryonic fibroblasts (MEFs) and identify topographical nonuniformity in this space, indicating nonuniform occupation of cytomorphological states within an isogenic population. The introduction of exogenous apoptotic agents fundamentally altered this energy landscape, inducing formation of additional energy minima that correlated directly with changes in sensitivity to apoptosis induction. An equilibrium framework allows us to describe the behavior of an ensemble of single cells, suggesting that although cells are complex nonequilibrium systems, the application of formalisms derived from equilibrium thermodynamics can provide insight into the basis of nongenetic heterogeneities within cell populations, as well as the relationship between cytomorphological and functional heterogeneity.

Thyrocyte cell survival and adaptation to chronic endoplasmic reticulum stress due to misfolded thyroglobulin.

The large secretory glycoprotein thyroglobulin is the primary translation product of thyroid follicular cells. This difficult-to-fold protein is susceptible to structural alterations that disable export of the misfolded thyroglobulin from the endoplasmic reticulum (ER), which is a known cause of congenital hypothyroidism characterized by severe chronic thyrocyte ER stress. Nevertheless, individuals with this disease commonly grow a goiter, indicating thyroid cell survival and adaptation. To model these processes, here we continuously exposed rat PCCL3 thyrocytes to tunicamycin, which causes a significant degree of ER stress that is specifically attributable to thyroglobulin misfolding. We found that, in response, PCCL3 cells down-regulate expression of the "tunicamycin transporter" (major facilitator superfamily domain containing-2A, Mfsd2a). Following CRISPR/Cas9-mediated Mfsd2a deletion, PCCL3 cells could no longer escape the chronic effects of high-dose tunicamycin, as demonstrated by persistent accumulation of unglycosylated thyroglobulin; nevertheless, these thyrocytes survived and grew. A proteomic analysis of these cells adapted to chronic ER protein misfolding revealed many hundreds of up-regulated proteins, indicating stimulation of ER chaperones, oxidoreductases, stress responses, and lipid biosynthesis pathways. Further, we noted increased phospho-AMP-kinase, suggesting up-regulated AMP-kinase activity, and decreased phospho-S6-kinase and protein translation, suggesting decreased mTOR activity. These changes are consistent with conserved cell survival/adaptation pathways. We also observed a less-differentiated thyrocyte phenotype with decreased PAX8, FOXE1, and TPO protein levels, along with decreased thyroglobulin mRNA levels. In summary, we have developed a model of thyrocyte survival and growth during chronic continuous ER stress that recapitulates features of congenital hypothyroid goiter caused by mutant thyroglobulin.

NUT Midline Carcinoma of the Lung: Computed Tomography Findings in 10 Patients.

OBJECTIVE: The aim of the study was to evaluate computed tomography (CT) findings of pulmonary NUT midline carcinoma. METHODS: We assessed clinical and CT features of pulmonary NUT carcinoma in 10 consecutive patients (M:F, 7:3; mean, 39 years). RESULTS: The primary tumors (size range, 15-65 mm) manifested as either a peripheral tumor (5/10) or a central tumor (5/10). All tumors showed relatively low-attenuation at contrast-enhanced CT (mean net enhancement, 26 HU). Associated CT findings were metastatic hilar or mediastinal lymphadenopathy (8/10), ipsilateral pleural seeding with malignant pleural effusion (2/10), and distant metastasis (2/10). Five patients with low tumor-node-metastasis stages after optimal treatment showed no evidence of disease (50%) for 6 to 35 months. CONCLUSIONS: Pulmonary NUT carcinoma presented as a peripheral or a central lung mass showing mild degree of contrast enhancement, frequent metastatic regional lymphadenopathy, affecting relatively young adults. Although known to be highly aggressive, an early diagnosis in low TNM stages can lead to a favorable prognosis.

Cardiovascular Complications in Patients with COVID-19: Consequences of Viral Toxicities and Host Immune Response.

PURPOSE OF REVIEW: Coronavirus disease of 2019 (COVID-19) is a cause of significant morbidity and mortality worldwide. While cardiac injury has been demonstrated in critically ill COVID-19 patients, the mechanism of injury remains unclear. Here, we review our current knowledge of the biology of SARS-CoV-2 and the potential mechanisms of myocardial injury due to viral toxicities and host immune responses. RECENT FINDINGS: A number of studies have reported an epidemiological association between history of cardiac disease and worsened outcome during COVID infection. Development of new onset myocardial injury during COVID-19 also increases mortality. While limited data exist, potential mechanisms of cardiac injury include direct viral entry through the angiotensin-converting enzyme 2 (ACE2) receptor and toxicity in host cells, hypoxia-related myocyte injury, and immune-mediated cytokine release syndrome. Potential treatments for reducing viral infection and excessive immune responses are also discussed. COVID patients with cardiac disease history or acquire new cardiac injury are at an increased risk for in-hospital morbidity and mortality. More studies are needed to address the mechanism of cardiotoxicity and the treatments that can minimize permanent damage to the cardiovascular system.

Correction to: Cardiovascular Complications in Patients with COVID-19: Consequences of Viral Toxicities and Host Immune Response.

It has been pointed out that the second paragraph of the section "Treatments for SARS-CoV-2 Infection" contains an error. The original article has been corrected.

Organelles - understanding noise and heterogeneity in cell biology at an intermediate scale.

Many studies over the years have shown that non-genetic mechanisms for producing cell-to-cell variation can lead to highly variable behaviors across genetically identical populations of cells. Most work to date has focused on gene expression noise as the primary source of phenotypic heterogeneity, yet other sources may also contribute. In this Commentary, we explore organelle-level heterogeneity as a potential secondary source of cellular 'noise' that contributes to phenotypic heterogeneity. We explore mechanisms for generating organelle heterogeneity and present evidence of functional links between organelle morphology and cellular behavior. Given the many instances in which molecular-level heterogeneity has been linked to phenotypic heterogeneity, we posit that organelle heterogeneity may similarly contribute to overall phenotypic heterogeneity and underline the importance of studying organelle heterogeneity to develop a more comprehensive understanding of phenotypic heterogeneity. Finally, we conclude with a discussion of the medical challenges associated with phenotypic heterogeneity and outline how improved methods for characterizing and controlling this heterogeneity may lead to improved therapeutic strategies and outcomes for patients.

Expanded validation of the EPIC bowel and urinary domains for use in women with gynecologic cancer undergoing postoperative radiotherapy.

OBJECTIVE: Women with endometrial or cervical cancer at risk for recurrence receive postoperative radiation therapy (RT). A patient reported outcomes (PRO) instrument to assess bowel and urinary toxicities is the Expanded Prostate Cancer Index Composite (EPIC), which has been validated in men with prostate cancer. As this instrument specifically measures bowel toxicity and the degree to which this is a problem, it was used in NRG Oncology/RTOG 1203 to compare intensity modulated RT (IMRT) to standard RT. This paper reports on the expanded validation of EPIC for use in women receiving pelvic RT. METHODS: In addition to the EPIC bowel domain, urinary toxicity (EPIC urinary domain), patient reported bowel toxicities (PRO-CTCAE) and quality of life (Functional Assessment of Cancer Therapy (FACT)) were completed before, during and after treatment. Sensitivity, reliability and concurrent validity were assessed. RESULTS: Mean bowel and urinary scores among 278 women enrolled were significantly worse during treatment and differed between groups. Acceptable to good reliability for bowel and urinary domain scores were obtained at all time points with the exception of one at baseline. Correlations between function and bother scores within the bowel and urinary domains were consistently stronger than those across domains. Correlations between bowel domain scores and PRO-CTCAE during treatment were stronger than those with the FACT. CONCLUSION: Correlations within and among the instruments indicate EPIC bowel and urinary domains are measuring conceptually discrete components of health. These EPIC domains are valid, reliable and sensitive instruments to measure PRO among women undergoing pelvic radiation.

Inferring cell state by quantitative motility analysis reveals a dynamic state system and broken detailed balance.

Cell populations display heterogeneous and dynamic phenotypic states at multiple scales. Similar to molecular features commonly used to explore cell heterogeneity, cell behavior is a rich phenotypic space that may allow for identification of relevant cell states. Inference of cell state from cell behavior across a time course may enable the investigation of dynamics of transitions between heterogeneous cell states, a task difficult to perform with destructive molecular observations. Cell motility is one such easily observed cell behavior with known biomedical relevance. To investigate heterogenous cell states and their dynamics through the lens of cell behavior, we developed Heteromotility, a software tool to extract quantitative motility features from timelapse cell images. In mouse embryonic fibroblasts (MEFs), myoblasts, and muscle stem cells (MuSCs), Heteromotility analysis identifies multiple motility phenotypes within the population. In all three systems, the motility state identity of individual cells is dynamic. Quantification of state transitions reveals that MuSCs undergoing activation transition through progressive motility states toward the myoblast phenotype. Transition rates during MuSC activation suggest non-linear kinetics. By probability flux analysis, we find that this MuSC motility state system breaks detailed balance, while the MEF and myoblast systems do not. Balanced behavior state transitions can be captured by equilibrium formalisms, while unbalanced switching between states violates equilibrium conditions and would require an external driving force. Our data indicate that the system regulating cell behavior can be decomposed into a set of attractor states which depend on the identity of the cell, together with a set of transitions between states. These results support a conceptual view of cell populations as dynamical systems, responding to inputs from signaling pathways and generating outputs in the form of state transitions and observable motile behaviors.

Hyperthermia-enhanced targeted drug delivery using magnetic resonance-guided focussed ultrasound: a pre-clinical study in a genetic model of pancreatic cancer.

PURPOSE: The lack of effective treatment options for pancreatic cancer has led to a 5-year survival rate of just 8%. Here, we evaluate the ability to enhance targeted drug delivery using mild hyperthermia in combination with the systemic administration of a low-temperature sensitive liposomal formulation of doxorubicin (LTSL-Dox) using a relevant model for pancreas cancer. MATERIALS AND METHODS: Experiments were performed in a genetically engineered mouse model of pancreatic cancer (KPC mice: LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre). LTSL-Dox or free doxorubicin (Dox) was administered via a tail vein catheter. A clinical magnetic resonance-guided high intensity focussed ultrasound (MR-HIFU) system was used to plan treatment, apply the HIFU-induce hyperthermia and monitor therapy. Post-therapy, total Dox concentration in tumour tissue was determined by HPLC and confirmed with fluorescence microscopy. RESULTS: Localized hyperthermia was successfully applied and monitored with a clinical MR-HIFU system. The mild hyperthermia heating algorithm administered by the MR-HIFU system resulted in homogenous heating within the region of interest. MR-HIFU, in combination with LTSL-Dox, resulted in a 23-fold increase in the localised drug concentration and nuclear uptake of doxorubicin within the tumour tissue of KPC mice compared to LTSL-Dox alone. Hyperthermia, in combination with free Dox, resulted in a 2-fold increase compared to Dox alone. CONCLUSION: This study demonstrates that HIFU-induced hyperthermia in combination with LTSL-Dox can be a non-invasive and effective method in enhancing the localised delivery and penetration of doxorubicin into pancreatic tumours.