Epigenetic regulation of hybrid epithelial-mesenchymal cell states in cancer

Epithelial-to-mesenchymal transition (EMT) is a process by which cells lose their epithelial characteristics and gain mesenchymal phenotypes. In cancer, EMT is thought to drive tumor invasion and metastasis. Recent efforts to understand EMT biology have uncovered that cells undergoing EMT attain a spectrum of intermediate "hybrid E/M" states, which exist along an epithelial-mesenchymal continuum. Here, we summarize recent studies characterizing the epigenetic drivers of hybrid E/M states. We focus on the histone-modification writers, erasers, and readers that assist or oppose the canonical hybrid E/M transcription factors that modulate hybrid E/M state transitions. We also examine the role of chromatin remodelers and DNA methylation in hybrid E/M states. Finally, we highlight the challenges of targeting hybrid E/M pharmacologically, and we propose future directions that might reveal the specific and targetable mechanisms by which hybrid E/M drives metastasis in patients.

Electrocardiographic profile of asymptomatic adolescents by the TELE ECG system in Brazil: analysis of 11058 patients

Introduction

The search for markers that can serve as screening methods for young practitioners of physical activity has always raised an intense discussion between pediatricians and cardiologists. Thus, the ideal investigation algorithm should identify patients at high risk also among asymptomatic patients and be of low cost to society. This would only be possible by including a low cost diagnostic method and largely accessible. In this context, telemedicine systems and in particular tele-electrocardiogram (tele-EKG) systems have low cost and agility and can collaborate to solve this problem.

Purpose

To analyze the electrocardiographic pattern in asymptomatic patients aged between 10 and 20 years old who underwent EKG by the tele-EKG system between 2007 and 2014

Methods

All EKG valid results from asymptomatic patients aged between 10 and 20 years old from 2007 and 2014 sent to the tele-EKG system of a large tertiary hospital were analysed aiming to determine the prevalence of abnormal findings.

Results

Of the 797,115 exams on the analysed period 25,326 were from patients aged between 10 and 20 years old and 11,058 (55% male) of them were asymptomatic. Regarding disorders of rhythm, ventricular arrhythmias were found in 0.54% and atrial premature beats in 0.47% of the exams. There were 5 episodes of supraventricular tachycardia (0.04%) and one episode of atrial fibrillation. Atrioventricular blocks were: first degree (0.71%) and second degree (0.03%). There was 1 case of 2:1 AV Block and 1 case of advanced AV block. Short PR interval was observed in 0.76% of the exams, with 15 of them showing ventricular pre-excitation (0.13%). Regarding morphological changes in EKG pattern, right bundle branch disorders were present in 7.5% of the patients and left bundle branch in 0.04%. Right bundle branch block occurred in 0.63% and left bundle branch block in only 1 case. Repolarization changes occurred in 1.8% of patients. We found left ventricular overload in 0.25% and right ventricular overload in 0.14% of cases. Only 5 patients had typical EKG of septal hypertrophy (0.045%). There were 1751 diagnostics overall, representing 15.8% of the sample. The most prevalent was right bundle branch abnormalities, followed by repolarization abnormalities (graphic below).

Conclusion

EKG screening in asymptomatic adolescents is a low cost and feasible method to identify individuals with electrical alterations and who require detailed clinical evaluation. This also may contribute to reduce risk of sudden events during sports activities.

Funding Acknowledgement

Type of funding sources: None.

A genome-scale CRISPR screen reveals PRMT1 as a critical regulator of androgen receptor signaling in prostate cancer

Androgen receptor (AR) signaling is the central driver of prostate cancer across disease states. While androgen deprivation therapy (ADT) is effective in the initial treatment of prostate cancer, resistance to ADT or to next-generation androgen pathway inhibitors invariably arises, most commonly through the re-activation of the AR axis. Thus, orthogonal approaches to inhibit AR signaling in advanced prostate cancer are essential. Here, via genome-scale CRISPR-Cas9 screening, we identify protein arginine methyltransferase 1 (PRMT1) as a critical mediator of AR expression and signaling. PRMT1 regulates the recruitment of AR to genomic target sites and the inhibition of PRMT1 impairs AR binding at lineage-specific enhancers, leading to decreased expression of key oncogenes, including AR itself. In addition, AR-driven prostate cancer cells are uniquely susceptible to combined AR and PRMT1 inhibition. Our findings implicate PRMT1 as a key regulator of AR output and provide a preclinical framework for co-targeting of AR and PRMT1 in advanced prostate cancer.

Genome-scale analysis identifies paralog lethality as a vulnerability of chromosome 1p loss in cancer

Functional redundancy shared by paralog genes may afford protection against genetic perturbations, but it can also result in genetic vulnerabilities due to mutual interdependency1-5. Here, we surveyed genome-scale short hairpin RNA and CRISPR screening data on hundreds of cancer cell lines and identified MAGOH and MAGOHB, core members of the splicing-dependent exon junction complex, as top-ranked paralog dependencies6-8. MAGOHB is the top gene dependency in cells with hemizygous MAGOH deletion, a pervasive genetic event that frequently occurs due to chromosome 1p loss. Inhibition of MAGOHB in a MAGOH-deleted context compromises viability by globally perturbing alternative splicing and RNA surveillance. Dependency on IPO13, an importin-β receptor that mediates nuclear import of the MAGOH/B-Y14 heterodimer9, is highly correlated with dependency on both MAGOH and MAGOHB. Both MAGOHB and IPO13 represent dependencies in murine xenografts with hemizygous MAGOH deletion. Our results identify MAGOH and MAGOHB as reciprocal paralog dependencies across cancer types and suggest a rationale for targeting the MAGOHB-IPO13 axis in cancers with chromosome 1p deletion.

Embryo transfer in Bos indicus cattle

In the present short review superovulation treatments commonly used for Bos taurus and/or Bos indicus will be addressed with emphasis in recent superstimulation protocols associated with pharmacological manipulation of the follicular dynamics to improve donor management and potentially embryo yield. Results obtained after superovulation treatments in which the time of LH surge is selectively delayed as an attempt to improve embryo yield are presented and discussed.

Pathology of experimental mycoplasmosis in American alligators

Mycoplasma alligatoris was the suspected etiology of an epidemic of acute multisystemic inflammatory disease which emerged in captive American alligators (Alligator mississippiensis) in Florida (USA) in 1995. In an experimental inoculation study conducted from April through October 1999, 18 alligators were inoculated with 10(2), 10(4), or 10(6) colony forming units (CFU) of M. alligatoris by instillation into the glottis. As early as 1 wk post-inoculation (PI), mycoplasma were cultured from blood of three of six alligators inoculated with 10(6) CFU. Two of those died and the third was euthanatized within 4 wk PI. Necropsy gross findings included fibrinous polyserositis and polyarthritis. Histopathologic changes in affected individuals included pulmonary edema, interstitial pneumonia, pericarditis, myocarditis, meningitis, and synovitis. Mycoplasma were cultured quantitatively in high numbers from trachea, lung, coelomic cavity, liver, spleen, interior of pericardial sac, heart, blood, brain, and limb joints. In alligators inoculated with 10(6) CFU, heterophilia and moderate hyperglycemia peaked about 4 wk PI, and seroconversion occurred by 6 to 8 wk PI. Necropsy gross and histologic findings were generally unremarkable for the surviving alligators inoculated with 10(6) CFU, alligators inoculated with 10(2) or 10(4) CFU, and four uninoculated control alligators. Mycoplasma were not cultured at any time point from those alligators. The findings confirm that M. alligatoris can cause fulminant inflammatory disease and rapid death of alligators.

Experimental inoculation of broad-nosed caimans (Caiman latirostris) and Siamese crocodiles (Crocodylus siamensis) with Mycoplasma alligatoris

An outbreak of mycoplasmosis caused by Mycoplasma alligatoris resulted in the death or euthanasia of 60 American alligators (Alligator mississippiensis) from a population of 74 captive bull alligators in Florida in 1995. The natural reservoir, routes of transmission, and host range of M. alligatoris are unknown. This study was undertaken to determine whether crocodilian species other than American alligators are susceptible to M. alligatoris. Six broad-nosed caimans (Caiman latirostris) and six Siamese crocodiles (Crocodylus siamensis) were experimentally inoculated with 10(6) colony forming units (CFU) of M. alligatoris instilled through the glottis. Two caimans and two crocodiles were used as negative controls. Six and four American alligators were used as positive and negative controls, respectively. Three of six (50%) inoculated caimans died within 10 wk postinoculation (PI) of severe mycoplasmosis. Gross necropsy, histopathologic, and culture results were similar for broad-nosed caimans and American alligators. None of the inoculated Siamese crocodiles developed mycoplasmosis, though M. alligatoris was isolated from the tonsils in three of six (50%) animals at necropsy. All the inoculated crocodilians that survived showed significant seroconversion by 6-8-wk PI (P < 0.05). The infective dose 50% (ID50) and lethal dose 50% (LD50) of M. alligatoris for the broad-nosed caiman are 10(6) CFU when instilled through the glottis, which is similar to that of the American alligator. Although the host range of M. alligatoris is not restricted to the American alligator, the organism does not appear to be pathogenic for Siamese crocodiles. Other species of crocodilians may be susceptible to infection with M. alligatoris, and this organism should be considered when the rapid onset of clinical signs of pneumonia, polyarthritis, pericarditis, and death occur.

Detection of antibodies to a pathogenic mycoplasma in American alligators (Alligator mississippiensis), broad-nosed Caimans (Caiman latirostris), and Siamese crocodiles (Crocodylus siamensis)

An epidemic of pneumonia with fibrinous polyserositis and multifocal arthritis emerged in captive American alligators (Alligator mississippiensis) in Florida, United States, in 1995. Mycoplasma alligatoris sp. nov. was cultured from multiple organs, peripheral blood, synovial fluid, and cerebrospinal fluid of affected alligators. In a subsequent experimental inoculation study, the Henle-Koch-Evans postulates were fulfilled for M. alligatoris as the etiological agent of fatal mycoplasmosis of alligators. That finding was remarkable because mycoplasmal disease is rarely fatal in animals. An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies produced by alligators in response to M. alligatoris exposure was developed by using plasma obtained from naturally infected alligators during the original epidemic. The assay was validated by using plasma obtained during an experimental dose-response study and applied to analyze plasma obtained from captive and wild crocodilian species. The ELISA reliably detected alligator seroconversion (P < 0.05) beginning 6 weeks after inoculation. The ELISA also detected seroconversion (P < 0.05) in the relatively closely related broad-nosed caiman Caiman latirostris and the relatively distantly related Siamese crocodile Crocodylus siamensis following experimental inoculation with M. alligatoris. The ELISA may be used to monitor exposure to the lethal pathogen M. alligatoris among captive, repatriated, and wild crocodilian species.

Tumoral form of ascariasis: report of a case

The authors report a case of a tumoral form of ascariasis in a 7-year-old boy, simulating a benign neoplasm. Microscopic examination revealed a marked granulomatous inflammatory reaction associated with dense fibroblastic proliferation and abscess formation around viable, embryonated Ascaris lumbricoides eggs. Pathogenesis of this rare clinical form of ascariasis is discussed.

A simple and economical modification of the Masson-Fontana method for staining melanin granules and enterochromaffin cells

Enterochromaffin cells from the small intestine of man, guinea pig, dog, chicken, rabbit, cat and rat were stained using the Masson-Fontana ammoniacal silver method with varying dilutions of silver nitrate solution (0.25 to 5 g per 100 ml of distilled water) and incubation temperatures (60 C and 75 C). The 0.5% solution of silver nitrate gave an argentaffin pattern similar to that of the 5% solution and had two major advantages: economically, since much less silver nitrate is used, and methodologically, since low background resulted with tissue of those species (rat, cat and rabbit) that required unusually long incubation. The staining of melanocytes was similar for all dilutions at the usual staining time (15-30 min).