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Abstract Background Plasmacytoid urothelial carcinoma (PUC) is a rare and aggressive subtype that often presents at advanced stages with poor prognosis. This study investigated tumor invasion to better understand tumor behavior and potentially to improve management strategies by comparing the clinicopathologic characteristics of PUC with positive ureter resection margin (+ URM) with PUC with negative URMs (-URM). Methods This retrospective analysis used pathology reports from 2017 to 2023 for cases diagnosed with PUC during radical cystectomy (RC). All applicable H&E slides of RC specimens were reviewed. Cases with a plasmacytoid component greater than 25% in the RC specimens were analyzed. Frozen section analyses (FSAs) and permanent section analyses (PSAs) of ureter resection margins were performed. Results Fifteen patients with a plasmacytoid component greater than 25% in their RC specimens were identified. Compared with -URM PUC cases, +URM PUC cases were located more frequently at the trigone or bladder neck, and all + URM cases exhibited ureter orifice involvement. Among 6 PSA-positive cases, three (50%) cases showed discrepancies with FSA. Three + URM cases exhibited PUC tumor cells along the submucosa and muscularis propria layer, and the 3 remaining cases showed PUC tumor cells along the adventitia. We observed a consistent adventitia invasion in all the discordant cases, with sectioning errors and misinterpretation identified as the primary causal factors. Conclusion To the best of our knowledge, this is the first study to demonstrate two separate patterns of tumor infiltration along the ureter and to discuss the significance of comparing FSA with PSA in PUC. The significance of comprehensive management strategies for PUC patients, including a thorough evaluation of ureteral margins and accurate interpretation of periureteral fat tissue, is highlighted. Large, well-designed studies are needed to strengthen the evidence and to establish optimal management strategies for patients with PUC.

Abstract Background Aerobic glycolysis is a tumor cell phenotype and a hallmark in cancer research. The alternative splicing of the pyruvate kinase M (PKM) gene regulates the expressions of PKM1/2 isoforms and the aerobic glycolysis of tumors. Polypyrimidine tract binding protein (PTBP1) is critical in this process; however, its impact and underlying mechanisms in colorectal cancer (CRC) remain unclear. This study aimed to investigate the role of PTBP1 crotonylation in CRC progression. Methods The crotonylation levels of PTBP1 in human CRC tissues and cell lines were analyzed using crotonylation proteomics and immunoprecipitation. The main crotonylation sites were identified by immunoprecipitation and immunofluorescent staining. The glycolytic capacities of CRC cells were evaluated by measuring the glucose uptake, lactate production, extracellular acidification rate, and glycolytic proton efflux rate. The role and mechanism of PTBP1 crotonylation in PKM alternative splicing were determined by Western blot, quantitative real-time PCR (RT-qPCR), RNA immunoprecipitation, and immunoprecipitation. The effects of PTBP1 crotonylation on the behaviors of CRC cells and CRC progression were assessed using CCK-8, colony formation, cell invasion, wound healing assays, xenograft model construction, and immunohistochemistry. Results The crotonylation level of PTBP1 was elevated in human CRC tissues compared to peritumor tissues. In CRC tissues and cells, PTBP1 was mainly crotonylated at K266 (PTBP1 K266-Cr), and lysine acetyltransferase 2B (KAT2B) acted as the crotonyltranferase. PTBP1 K266-Cr promoted glycolysis and lactic acid production, increasing the PKM2/PKM1 ratio in CRC tissues and cells. Mechanistically, PTBP1 K266-Cr enhanced the interaction of PTBP1 with heterogeneous nuclear ribonucleoprotein A1 and A2 (hnRNPA1/2), thus affecting the PKM alternative splicing. PTBP1 K266-Cr facilitated CRC cell proliferation, migration, and metastasis in vitro and in vivo. Pathologically, a high level of PTBP1 K266-Cr was associated with poor prognosis in CRC patients. Conclusions Crotonylation of PTBP1 coordinates tumor cell glycolysis and promotes CRC progression by regulating PKM alternative splicing and increasing PKM2 expression.

Abstract Direct cardiac reprogramming represents a novel therapeutic strategy to convert non-cardiac cells such as fibroblasts into cardiomyocytes (CMs). This process involves essential transcription factors, such as Mef2c, Gata4, Tbx5 (MGT), MESP1, and MYOCD (MGTMM). However, the small molecules responsible for inducing immature induced CMs (iCMs) and the signaling mechanisms driving their maturation remain elusive. Our study explored the effects of various small molecules on iCM induction and discovered that the combination of FGF4 and ascorbic acid (FA) enhances CM markers, exhibits organized sarcomere and T-tubule structures, and improves cardiac function. Transcriptome analysis emphasized the importance of ECM-integrin-focal adhesions and the upregulation of the JAK2–STAT3 and TGFB signaling pathways in FA-treated iCMs. Notably, JAK2–STAT3 knockdown affected TGFB signaling and the ECM and downregulated mature CM markers in FA-treated iCMs. Our findings underscore the critical role of the JAK2–STAT3 signaling pathway in activating TGFB signaling and ECM synthesis in directly reprogrammed CMs. Schematic showing FA enhances direct cardiac reprogramming and JAK–STAT3 signaling pathways underlying cardiomyocyte maturation.

Abstract The prevalence of myopia is rapidly increasing, significantly impacting the quality of life of affected individuals. Prior research by our group revealed reactive gliosis in Müller cells within myopic retina, prompting further investigation of their role in myopia, which remains unclear. In this study, we analyzed protein expression changes in CD29+ Müller cells isolated from a form deprivation-induced rabbit model of myopia using magnetic activated cell sorting to investigate the role of these cells in myopia. As the principal glial cells in the retina, Müller cells exhibited significant alterations in the components of metabolic pathways, particularly glycolysis and angiogenesis, including the upregulation of glycolytic enzymes, such as lactate dehydrogenase A and pyruvate kinase, implicated in the adaptation to increased metabolic demands under myopic stress. Additionally, a decrease in the expression of proteins associated with oxygen transport suggested enhanced vulnerability to oxidative stress. These findings highlight the proactive role of CD29+ Müller cells in modifying the retinal environment in response to myopic stress and provide valuable insights into mechanisms that could help mitigate myopia progression.

Abstract Ferritin, comprising heavy (FTH1) and light (FTL) chains, is the main iron storage protein, and pancreatic cancer patients exhibit elevated serum ferritin levels. Specifically, higher ferritin levels are correlated with poorer pancreatic ductal adenocarcinoma (PDAC) prognosis; however, the underlying mechanism and metabolic programming of ferritin involved in KRAS-mutant PDAC progression remain unclear. Here, we observed a direct correlation between FTH1 expression and cell viability and clonogenicity in KRAS-mutant PDAC cell lines as well as with in vivo tumor growth through the control of proline metabolism. Our investigation highlights the intricate relationship between FTH1 and pyrroline-5-carboxylate reductase 1 (PYCR1), a crucial mitochondrial enzyme facilitating the glutamate-to-proline conversion, underscoring its impact on proline metabolic imbalance in KRAS-mutant PDAC. This regulation is further reversed by miR-5000-3p, whose dysregulation results in the disruption of proline metabolism, thereby accentuating the progression of KRAS-mutant PDAC. Additionally, our study demonstrated that deferasirox, an oral iron chelator, significantly diminishes cell viability and tumor growth in KRAS-mutant PDAC by targeting FTH1-mediated pathways and altering the PYCR1/PRODH expression ratio. These findings underscore the novel role of FTH1 in proline metabolism and its potential as a target for PDAC therapy development.

Background/Aims: We investigated how interactions between humans and computer-aided detection (CADe) systems are influenced by the user’s experience and polyp characteristics.Methods: We developed a CADe system using YOLOv4, trained on 16,996 polyp images from 1,914 patients and 1,800 synthesized sessile serrated lesion (SSL) images. The performance of polyp detection with CADe assistance was evaluated using a computerized test module. Eighteen participants were grouped by colonoscopy experience (nurses, fellows, and experts). The value added by CADe based on the histopathology and detection difficulty of polyps were analyzed.Results: The area under the curve for CADe was 0.87 (95% confidence interval [CI], 0.83 to 0.91). CADe assistance increased overall polyp detection accuracy from 69.7% to 77.7% (odds ratio [OR], 1.88; 95% CI, 1.69 to 2.09). However, accuracy decreased when CADe inaccurately detected a polyp (OR, 0.72; 95% CI, 0.58 to 0.87). The impact of CADe assistance was most and least prominent in the nurses (OR, 1.97; 95% CI, 1.71 to 2.27) and the experts (OR, 1.42; 95% CI, 1.15 to 1.74), respectively. Participants demonstrated better sensitivity with CADe assistance, achieving 81.7% for adenomas and 92.4% for easy-to-detect polyps, surpassing the standalone CADe performance of 79.7% and 89.8%, respectively. For SSLs and difficult-to-detect polyps, participants' sensitivities with CADe assistance (66.5% and 71.5%, respectively) were below those of standalone CADe (81.1% and 74.4%). Compared to the other two groups (56.1% and 61.7%), the expert group showed sensitivity closest to that of standalone CADe in detecting SSLs (79.7% vs 81.1%, respectively).Conclusions: CADe assistance boosts polyp detection significantly, but its effectiveness depends on the user’s experience, particularly for challenging lesions.