Sex differences in corneal neovascularization in response to superficial corneal cautery in the rat.

Sex-based differences in susceptibility have been reported for a number of neovascular ocular diseases. We quantified corneal neovascularization, induced by superficial silver nitrate cautery, in male and female inbred albino Sprague-Dawley, inbred albino Fischer 344, outbred pigmented Hooded Wistar and inbred pigmented Dark Agouti rats of a range of ages. Corneal neovascular area was quantified on haematoxylin-stained corneal flatmounts by image analysis. Pro-and anti-angiogenic gene expression was measured early in the neovascular response by quantitative real-time polymerase chain reaction. Androgen and estrogen receptor expression was assessed by immunohistochemistry. Male rats from all strains, with or without ocular pigmentation, exhibited significantly greater corneal neovascular area than females: Sprague-Dawley males 43±12% (n = 8), females 25±5% (n = 12), p = 0.001; Fischer 344 males 38±10% (n = 12) females 27±8% (n = 8) p = 0.043; Hooded Wistar males 32±6% (n = 8) females 22±5% (n = 12) p = 0.002; Dark Agouti males 37±11% (n = 9) females 26±7% (n = 9) p = 0.015. Corneal vascular endothelial cells expressed neither androgen nor estrogen receptor. The expression in cornea post-cautery of Cox-2, Vegf-a and Vegf-r2 was significantly higher in males compared with females and Vegf-r1 was significantly lower in the cornea of males compared to females, p<0.001 for each comparison. These data suggest that male corneas are primed for angiogenesis through a signalling nexus involving Cox-2, Vegf-a, and Vegf receptors 1 and 2. Our findings re-enforce that pre-clinical animal models of human diseases should account for sex-based differences in their design and highlight the need for well characterized and reproducible pre-clinical studies that include both male and female animals

EUS-directed transgastric interventions in Roux-En-Y Gastric Bypass anatomy: a multicenter experience

Background and Aims Placement of a Lumen Apposing Metal Stent (LAMS) between the gastric pouch and the excluded stomach allows for EUS Guided Transgastric Interventions (EDGI) in patients with Roux-en-Y gastric bypass (RYGB). Although EUS guided transgastric ERCP (EDGE) outcomes have been reported, there is a paucity of data on other endoscopic interventions. We aimed to evaluate the outcomes and safety of EDGI. Methods This is a retrospective study involving 9 centers (8 USA, 1 Europe) and included patients with RYGB who underwent EDGI between 06/2015 and 09/2021. The primary outcome was the technical success of EDGI. Secondary outcomes included adverse events, length of hospital stay, and fistula follow-up and management. Results 54 EDGI procedures were performed in 47 patients (mean age 61yr, F 72%), most commonly for the evaluation of a pancreatic mass (n=16) and management of pancreatic fluid collections (n=10). A 20mm LAMS was utilized in 26 patients and a 15mm LAMS in 21, creating a gastrogastrostomy (GG) in 37 patients and jejunogastrostomy (JG) in 10. Most patients (n=30, 64%) underwent a dual-session EDGI, with a median interval of 17d between the 2 procedures. Single-session EDGI was performed in 17 patients, of whom 10 (59%) had anchoring of the LAMS. The most common interventions were diagnostic EUS (+/-FNA/B) (n=28) and EUS-guided cystgastrostomy (n=8). The mean procedural time was 97.6 ± 78.9 mins. Technical success was achieved in 52 (96%). AEs occurred in 5 (10.6%) patients, of which only 1 (2.1%) was graded as severe. Intraprocedural LAMS migration was the most common AE, occurring in 3 patients (6.4%), while delayed spontaneous LAMS migration occurred in 2 (4.3%). 4 of the 5 LAMS migration events were managed endoscopically, and one required surgical repair. LAMS anchoring was found to be protective against LAMS migration (p=0.001). The median duration of hospital stay was 2.1 ± 3.7d. Of the 17 patients who underwent objective fistula assessment endoscopically/radiologically after LAMS removal, 2 (11.7%) were found to have persistent fistulas. In one case the fistula was intentionally left open to assist with weight gain. The other fistula was successfully closed endoscopically. Conclusion EDGI is effective and safe for the diagnosis and management of pancreatobiliary and foregut disorders in RYGB patients. It is associated with high rates of technical success and low rates of severe AEs. LAMS migration is the most common AE with evidence that anchoring can be protective against its occurrence. Persistent fistulas may occur, but endoscopic closure seems effective

Factors predictive of persistent fistulas in EUS-Directed transgastric ERCP: A multicenter matched case-control study

BACKGROUND: EUS-directed transgastric ERCP (EDGE) is an established method for managing pancreaticobiliary pathology in Roux-en-Y gastric bypass patients, with high rates of technical success and low rates of serious adverse events (AEs). However widespread adoption of the technique has been limited due to concerns about the development of persistent gastrogastric (GG) or jejunogastric (JG) fistulas. GG/GJ fistulas have been reported in up to 20% of cases in some series, but predictive risk factors and long-term management/outcomes are lacking. AIMS: To assess (1) factors associated with the development of persistent fistulas; (2) technical success of endoscopic fistula closure. PATIENTS AND METHODS: This is a case-control study involving 9 centers (8 USA, 1 Europe) from 02/2015 to 09/2021. Cases of persistent fistulas were defined as endoscopic or imaging evidence of fistula more than 8 weeks after lumen-apposing metal stent (LAMS) removal. Controls were defined as endoscopic or imaging confirmation of no fistula more than 8 weeks after LAMS removal. AEs were defined/graded according to ASGE lexicon. RESULTS: 25 patients identified to have evidence of a persistent fistula on follow-up surveillance (cases) were matched with 50 patients with no evidence of a persistent fistula on follow-up surveillance (controls) based on age and sex. Mean LAMS dwell time was 74.7±106.2d. Following LAMS removal, argon plasma coagulation (APC) ablation of the fistula was performed in 46 (61.3%). Primary closure of the fistula was performed in 26.7% (n=20, endoscopic suturing in 17, endoscopic tacking in 2 and over-the-scope clips + endoscopic suturing in 1). When comparing cases to controls, there was no difference in baseline demographics, fistula site, LAMS size, or primary closure frequency between the two groups (p\u3e0.05). However, in the persistent fistula group, the mean LAMS dwell time was significantly longer (127 d vs 48 d, p=0.02), and more patients had ≥5% total body weight gain (33.3% vs 10.3%; p=0.03). LAMS dwell time was a significant predictor of persistent fistula (OR=4.5 after \u3e40 days in situ, p=0.01). The odds of developing a persistent fistula increased by 9.5% for every 7 days that the LAMS was left in situ. In patients with a persistent fistula, endoscopic closure was attempted in 76% (n=19) with successful resolution in 14 (73.7%). CONCLUSIONS: Longer LAMS dwell time was found to be associated with a higher risk of persistent fistulas in EDGE patients. APC or primary closure of the fistula on LAMS removal was not found to be protective against developing a persistent fistula, which if present, can be effectively managed through endoscopic closure in most cases

Human DECR1 is an androgen-repressed survival factor that regulates PUFA oxidation to Protect prostate tumor cells from ferroptosis

Fatty acid β-oxidation (FAO) is the main bioenergetic pathway in human prostate cancer (PCa) and a promising novel therapeutic vulnerability. Here we demonstrate therapeutic efficacy of targeting FAO in clinical prostate tumors cultured ex vivo, and identify DECR1, encoding the rate-limiting enzyme for oxidation of polyunsaturated fatty acids (PUFAs), as robustly overexpressed in PCa tissues and associated with shorter relapse-free survival. DECR1 is a negatively-regulated androgen receptor (AR) target gene and, therefore, may promote PCa cell survival and resistance to AR targeting therapeutics. DECR1 knockdown selectively inhibited β-oxidation of PUFAs, inhibited proliferation and migration of PCa cells, including treatment resistant lines, and suppressed tumor cell proliferation and metastasis in mouse xenograft models. Mechanistically, targeting of DECR1 caused cellular accumulation of PUFAs, enhanced mitochondrial oxidative stress and lipid peroxidation, and induced ferroptosis. These findings implicate PUFA oxidation via DECR1 as an unexplored facet of FAO that promotes survival of PCa cells.status: publishe

Reciprocal signaling between mTORC1 and MNK2 controls cell growth and oncogenesis

eIF4E plays key roles in protein synthesis and tumorigenesis. It is phosphorylated by the kinases MNK1 and MNK2. Binding of MNKs to eIF4G enhances their ability to phosphorylate eIF4E. Here, we show that mTORC1, a key regulator of mRNA translation and oncogenesis, directly phosphorylates MNK2 on Ser74. This suppresses MNK2 activity and impairs binding of MNK2 to eIF4G. These effects provide a novel mechanism by which mTORC1 signaling impairs the function of MNK2 and thereby decreases eIF4E phosphorylation. MNK2[S74A] knock-in cells show enhanced phosphorylation of eIF4E and S6K1 (i.e., increased mTORC1 signaling), enlarged cell size, and increased invasive and transformative capacities. MNK2[Ser74] phosphorylation was inversely correlated with disease progression in human prostate tumors. MNK inhibition exerted anti-proliferative effects in prostate cancer cells in vitro. These findings define a novel feedback loop whereby mTORC1 represses MNK2 activity and oncogenic signaling through eIF4E phosphorylation, allowing reciprocal regulation of these two oncogenic pathways

A Novel Role for DNA-PK in Metabolism by Regulating Glycolysis in Castration Resistant Prostate Cancer.

PURPOSE: DNA-dependent kinase catalytic subunit (DNA-PKcs, herein referred as DNA-PK) is a multifunctional kinase of high cancer relevance. DNA-PK is deregulated in multiple tumor types, including prostate cancer (PCa), and is associated with poor outcomes. DNA-PK was previously nominated as a therapeutic target and DNA-PK inhibitors are currently undergoing clinical investigation. While DNA-PK is well studied in DNA repair and transcriptional regulation, much remains to be understood about the way by which DNA-PK drives aggressive disease phenotypes. EXPERIMENTAL DESIGN: Here, unbiased proteomic and metabolomic approaches in clinically relevant tumor models uncovered a novel role of DNA-PK in metabolic regulation of cancer progression. DNA-PK regulation of metabolism was interrogated using pharmacological and genetic perturbation using in vitro cell models, in vivo xenografts, and ex vivo in patient-derived explants (PDE). RESULTS: Key findings reveal: i) the first-in-field DNA-PK protein-protein interactome; ii) numerous DNA-PK novel partners involved in glycolysis, iii) DNA-PK interacts with, phosphorylates (in vitro) and increases the enzymatic activity of glycolytic enzymes ALDOA and PKM2, iv) DNA-PK drives synthesis of glucose-derived pyruvate and lactate, v) DNA-PK regulates glycolysis in vitro, in vivo and ex vivo, and vi) combination of DNA-PK inhibitor with glycolytic inhibitor 2-deoxyglucose leads to additive anti-proliferative effects in aggressive disease. CONCLUSIONS: Findings herein unveil novel DNA-PK partners, substrates, and function in PCa. The role of DNA-PK impacts glycolysis through direct interaction with glycolytic enzymes and modulation of enzymatic activity. These events support energy production that may contribute to generation and/or maintenance of DNA-PK-mediated aggressive disease phenotypes

Lipidomic Profiling of Clinical Prostate Cancer Reveals Targetable Alterations in Membrane Lipid Composition.

peer reviewedDysregulated lipid metabolism is a prominent feature of prostate cancer that is driven by androgen receptor (AR) signaling. Here we used quantitative mass spectrometry to define the "lipidome" in prostate tumors with matched benign tissues (n = 21), independent unmatched tissues (n = 47), and primary prostate explants cultured with the clinical AR antagonist enzalutamide (n = 43). Significant differences in lipid composition were detected and spatially visualized in tumors compared with matched benign samples. Notably, tumors featured higher proportions of monounsaturated lipids overall and elongated fatty acid chains in phosphatidylinositol and phosphatidylserine lipids. Significant associations between lipid profile and malignancy were validated in unmatched samples, and phospholipid composition was characteristically altered in patient tissues that responded to AR inhibition. Importantly, targeting tumor-related lipid features via inhibition of acetyl-CoA carboxylase 1 significantly reduced cellular proliferation and induced apoptosis in tissue explants. This characterization of the prostate cancer lipidome in clinical tissues reveals enhanced fatty acid synthesis, elongation, and desaturation as tumor-defining features, with potential for therapeutic targeting. SIGNIFICANCE: This study identifies malignancy and treatment-associated changes in lipid composition of clinical prostate cancer tissues, suggesting that mediators of these lipidomic changes could be targeted using existing metabolic agents