Inhibition of Protein Phosphatase 2A Sensitizes Mucoepidermoid Carcinoma to Chemotherapy via the PI3K-AKT Pathway in Response to Insulin Stimulus.

BACKGROUND/AIMS: Protein phosphatase 2A (PP2A) is a ubiquitous serine/threonine phosphatase that mediates cell cycle regulation and metabolism. Mounting evidence has indicated that PP2A inhibition exhibits considerable anticancer potency in multiple types of human cancers. However, the efficacy of PP2A inhibition remains unexplored in mucoepidermoid carcinoma (MEC), especially in locally advanced and metastatic cases with limited systemic treatment. In this study, we demonstrated the therapeutic potency of LB100 in mucoepidermoid carcinoma. METHODS: In this study, the expression of PP2A was evaluated using immunohistochemical (IHC) staining. The effects associated with LB100 alone and in combination with cisplatin for the treatment of mucoepidermoid carcinoma were investigated both in vitro, regarding metabolism, proliferation, and migration, and in vivo in a mucoepidermoid carcinoma xenograft model. In addition, with LB100 treatment and in response to an insulin stimulus, the expression levels and phosphorylation levels of targets in the PI3K-AKT pathway were determined using western blot analysis and immunoblotting. RESULTS: The expression of protein phosphatase 2A was significantly upregulated in the clinical specimens of high-grade MECs compared with those of low-/medium-grade MECs and normal controls. In this article, we report that a small molecule PP2A inhibitor, LB100, decreased cellular viability and glycolytic activity and induced G2/M cell cycle arrest. Importantly, LB100 enhanced the efficacy of cisplatin in mucoepidermoid carcinoma cells both in vitro and in vivo. PP2A inhibition by LB100 increased the phosphorylation of insulin receptor substrate 1(IRS-1) on serine residues, downregulated the expression of phosphatidylinositol 3-kinase (PI3K) p110 alpha subunit and dephosphorylated AKT at Ser473 and Thr308 in mucoepidermoid carcinoma cells in response to insulin stimulus. CONCLUSION: These results highlight the translational potential of PP2A inhibition to synergize with cisplatin in mucoepidermoid carcinoma treatment.

Genome Evolution Analysis of Recurrent Testicular Malignant Mesothelioma by Whole-Genome Sequencing.

BACKGROUND/AIMS: Malignant mesothelioma of the tunica vaginalis testis is a rare and lethal disease. The genomic characteristics and genetic changes of tumor cells during the progression of this disease are unknown. METHODS: we performed whole-genome sequencing of four successive tumor samples derived from surgery and a blood sample in a single patient. RESULTS: All tumors were found to have significant C-to-T and T-to-C mutations, and amplification of copy number in chromosomes 1 and 12 were notified in all tumor samples. Subclone analysis revealed a parallel evolution of the tumor in this patient. We also identified some mutations in mesothelioma-associated genes such as KIF25, AHNAK, and PRDM2. CONCLUSIONS: The results showed a comprehensive genomic change in malignant mesothelioma of the tunica vaginalis testis and provide a better understanding of the clonal evolution during tumor recurrence and metastasis.

Diameter and depth of femoral vessels by duplex ultrasound.

BACKGROUND: The anatomy of the femoral artery and vein plays an integral role in vascular access. Both technical feasibility and complication rates are associated with femoral vessel diameter and depth. The goal of this study is to establish normative values for common femoral artery (CFA) and vein (CFV) depth and diameter using a large, diverse patient population. METHODS: A retrospective review of all patients undergoing lower extremity venous duplex imaging over a 1 year period were reviewed. Patients with inadequate imaging or with evidence of deep vein thrombosis were excluded. The index image of all studies was a non-compressed view of the common femoral vein at the saphenous-femoral junction. All measurements were taken from this still. Vessel diameters were measured from intima to intima. Depth was measured from skin to intima. BMI and BSA were calculated using standard formulas. Chi square was used for univariate analysis. Linear regression was used to establish correlation. RESULTS: Over the 1 year period, 983 patients met criteria for inclusion. The majority were male (53%) with a mean age of 55. The patients were 47% white and 44% black. The majority had hypertension (53%). The mean BMI and BSA were 29 and 2, respectively. Mean CFA depth was 1.7 cm, while mean CFV depth was 1.8 cm. The mean CFA and CFV diameters were 0.9 and 1.1 cm, respectively. Amongst height, weight, BMI, and BSA, weight correlated best with CFA (R = 0.548) and CFV (R = 0.552) depth, while BSA correlated best for diameter for both CFA (R = 0.390) and CFV (R = 0.440). CONCLUSIONS: This study establishes mean diameters and depths for the common femoral artery and vein using a large, diverse patient group. BSA was most closely associated with vessel diameter, while weight was correlated with depth. This study provides normative diameter and depth values for the common femoral vasculature, which may assist in vascular access planning for providers.

New Developments in the Pathogenesis, Therapeutic Targeting, and Treatment of Pediatric Medulloblastoma.

Pediatric medulloblastoma (MB) is the most common pediatric brain tumor with varying prognoses depending on the distinct molecular subtype. The four consensus subgroups are WNT, Sonic hedgehog (SHH), Group 3, and Group 4, which underpin the current 2021 WHO classification of MB. While the field of knowledge for treating this disease has significantly advanced over the past decade, a deeper understanding is still required to improve the clinical outcomes for pediatric patients, who are often vulnerable in ways that adult patients are not. Here, we discuss how recent insights into the pathogenesis of pediatric medulloblastoma have directed current and future research. This review highlights new developments in understanding the four molecular subtypes' pathophysiology, epigenetics, and therapeutic targeting. In addition, we provide a focused discussion of recent developments in imaging, and in the surgery, chemotherapy, and radiotherapy of pediatric medulloblastoma. The article includes a brief explanation of healthcare costs associated with medulloblastoma treatment.

Discharge Opioid Prescribing Patterns in an Academic Orthopaedic Setting: Level of Training and Subspecialty Patterns.

INTRODUCTION: Despite increased research on opioids in the orthopaedic literature, little is known of the prescribing practices of orthopaedic providers based on their level of training. The purpose of this study was to describe the discharge opioid prescribing patterns of orthopaedic providers, stratifying by level of training and orthopaedic subspecialty, within a single medical system. METHODS: A retrospective review of orthopaedic surgical encounters was performed over a 1-year period for adults who received a discharge opioid prescription. Patient demographics and prescriber characteristics were collected, including the provider's level of training (attending, fellow, resident, physician assistant [PA], and nurse practitioner [NP]) and surgical subspecialty. Junior residents were postgraduate year 1 to 3, whereas senior residents/fellows were postgraduate year 4 to 6. Discharge opioids were converted to milligram morphine equivalents (MMEs). Overprescribing was defined as a prescribing more than a seven-day supply or >45 MMEs per day. Multivariable linear regression analysis determined the factors associated with discharge MMEs, whereas logistic regression determined the factors associated with overprescribing opioids. RESULTS: Of the 3,786 patients reviewed, 1,500 met the criteria for inclusion in the study. The greatest proportion of opioid prescriptions was written by junior residents (33.9%), followed by NPs (30.1%), PAs (24.1%), senior residents/fellows (10.6%), and attendings (1.2%). Compared with junior residents, senior residents prescribed -59.4 MMEs, NPs prescribed +104 MMEs, and attendings prescribed +168 MMEs (P < 0.05), whereas PAs prescribed similar amounts (P > 0.05). Orthopaedic subspecialty was also predictive of discharge MMEs (P < 0.05). Senior residents and attendings were more likely to prescribe more than seven days of opioids (P < 0.05), whereas NPs and PAs were more likely to prescribe >45 MMEs per day (P < 0.05). DISCUSSION: This study demonstrates significant variability in opioid prescribing practices according to provider level of training and subspecialty. National guidelines for opioid prescribing practices and educational programs may help reduce such variability. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Gen1 mutation caused kidney hypoplasia and defective ureter-bladder connections in mice.

Limited genetic factors were uncovered for the development of congenital anomalies of the kidney and urinary tract (CAKUT). We previously reported that a Holliday junction resolvase Gen1 was essential for early metanephric development in mice. This comprehensive follow-up study focused on the roles of Gen1 in late metanephric development. We found that Gen1 mutation impaired the late development of both kidney and urinary tract. In vivo and ex-vivo kidney primordia culture confirmed decreased ureteric bud branching in Gen1 mutants, which consequently caused hypoplasia. We also observed abnormal urinary tract development. Programmed apoptosis at the end of nephric duct disappeared in Gen1 mutants, which caused abnormal ureter-bladder connections, leading to vesicoureteral reflux (VUR) or ureterovesical junction obstruction (UVJO). Mechanistically, RNA-seq analysis proved that Gen1 mutation impaired the expression of multiple regulatory genes for the metanephric development, including Six2. Taken together, our study provides more insight into the roles of Gen1 in the development of the kidney and urinary tract, which may have potential clinical significance in the treatment and/or prevention of CAKUT.

Striatal Projection Neurons Require Huntingtin for Synaptic Connectivity and Survival.

Huntington's disease (HD) is caused by an autosomal dominant polyglutamine expansion mutation of Huntingtin (HTT). HD patients suffer from progressive motor, cognitive, and psychiatric impairments, along with significant degeneration of the striatal projection neurons (SPNs) of the striatum. HD is widely accepted to be caused by a toxic gain-of-function of mutant HTT. However, whether loss of HTT function, because of dominant-negative effects of the mutant protein, plays a role in HD and whether HTT is required for SPN health and function are not known. Here, we delete Htt from specific subpopulations of SPNs using the Cre-Lox system and find that SPNs require HTT for motor regulation, synaptic development, cell health, and survival during aging. Our results suggest that loss of HTT function in SPNs could play a critical role in HD pathogenesis.

A Transgenic Mouse Model of Pacak⁻Zhuang Syndrome with An Epas1 Gain-of-Function Mutation.

We previously identified a novel syndrome in patients characterized by paraganglioma, somatostatinoma, and polycythemia. In these patients, polycythemia occurs long before any tumor develops, and tumor removal only partially corrects polycythemia, with recurrence occurring shortly after surgery. Genetic mosaicism of gain-of-function mutations of the EPAS1 gene (encoding HIF2α) located in the oxygen degradation domain (ODD), typically p.530-532, was shown as the etiology of this syndrome. The aim of the present investigation was to demonstrate that these mutations are necessary and sufficient for the development of the symptoms. We developed transgenic mice with a gain-of-function Epas1A529V mutation (corresponding to human EPAS1A530V), which demonstrated elevated levels of erythropoietin and polycythemia, a decreased urinary metanephrine-to-normetanephrine ratio, and increased expression of somatostatin in the ampullary region of duodenum. Further, inhibition of HIF2α with its specific inhibitor PT2385 significantly reduced erythropoietin levels in the mutant mice. However, polycythemia persisted after PT2385 treatment, suggesting an alternative erythropoietin-independent mechanism of polycythemia. These findings demonstrate the vital roles of EPAS1 mutations in the syndrome development and the great potential of the Epas1A529V animal model for further pathogenesis and therapeutics studies.

Overexpression of leucine-rich repeat-containing G protein-coupled receptor 5 predicts poor prognosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common malignancies and the fifth leading cause of cancer-related death worldwide. Novel prognostic biomarkers are urgently needed for patients with HCC. Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) overexpression may promote tumor metastasis in HCC. However, few studies investigate the prognosis predictive role of LGR5 in patients with HCC. Herein, we aimed to examine the expression level of LGR5 in tumors and its correlation with clinical characteristics and survivals of patients with HCC. LGR5 expression in tumor specimens and adjacent tissue resected from 66 patients were detected by immunohistochemistry. The results showed that the expression of LGR5 was markedly higher in HCC than in normal adjacent tissues (P = .006). High expression of LGR5 was significantly correlated with later disease stage (P = .009). In addition, high LGR5 expression was remarkably correlated with short overall survival than those with low LGR5 expression (P < .05). The median overall survival of patients with high LGR5 expression was 12 months, whereas that of patients with low LGR5 expression was still not reached (longer than 70 months). Notably, in our limited cases, we did not detect any difference in tumor size, lymphatic invasion, or metastasis in patients with high or low expression of LGR5. In conclusion, high protein level of LGR5 was associated with poor prognosis of these patients. LGR5 appears to be a valuable prognostic predictor clinically and a potential target in HCC therapy.

Circulating tumor cell clusters: What we know and what we expect (Review).

The major cause of cancer-associated mortality is tumor metastasis, a disease that is far from understood. Many studies have observed circulating tumor cells (CTCs) in patients' circulation systems, and a few latest investigations showed that CTC clusters have a potentially high capacity of metastasis. The capture and analysis of CTC clusters offer new insights into tumor metastasis and can facilitate the development of cancer treatments. We reviewed the research history of the CTC clusters, as well as the technologies used for detecting and isolating CTC clusters. In addition, we discuss the characteristics of CTC clusters and their roles in tumor dissemination. Clinical relevance of CTC clusters was also implicated in currently limited data. Moving forward, the next frontier in this field is to develop more efficient capture methods and decipher conundrums of characterization of CTC clusters. This will ultimately identify the clinical value of CTC clusters as a biomarker and therapeutic target.

Safety of histamine-2 receptor blockers in hospitalized VLBW infants.

BACKGROUND: Histamine-2 receptor (H2) blockers are often used in very low birth weight infants despite lack of population specific efficacy and safety data. AIMS: We sought to describe safety and temporal trends in histamine-2 receptor (H2) blocker use in hospitalized very low birth weight (VLBW) infants. STUDY DESIGN: We conducted a retrospective cohort study using a clinical database populated by an electronic health record shared by 348 neonatal intensive care units in the United States. SUBJECTS: We included all VLBW infants without major congenital anomalies. OUTCOME MEASURES: We used multivariable logistic regression with generalizing estimating equations to evaluate the association between days of H2 blocker exposure and risk of: 1) death or necrotizing enterocolitis (NEC); 2) death or sepsis; and 3) death, NEC, or sepsis. RESULTS: Of 127,707 infants, 20,288 (16%) were exposed to H2 blockers for a total of 6,422,352days. Median gestational age for infants exposed to H2 blockers was 27weeks (25th 75th percentile 26, 29). H2 blocker use decreased from 18% of infants in 1997 to 8% in 2012 (p<0.001). On multivariable analysis, infants were at increased risk of the combined outcome of death, NEC, or sepsis on days exposed to H2 blockers (odds ratio=1.14) (95% confidence interval 1.08, 1.19). CONCLUSIONS: H2 blocker use is associated with increased risk of the combined outcome of death, NEC, or sepsis in hospitalized VLBW infants.