Does Ta Low Grade Urothelial Carcinoma of the Bladder with Focal High-Grade Features Carry Worse Prognosis? The Roswell Park Comprehensive Cancer Center Experience.

OBJECTIVES: To describe the management and outcomes of patients with Ta predominantly low-grade urothelial carcinoma with focal high-grade features (FHG) (<5%), compared to those with Ta low grade (LG) and Ta high grade (HG). METHODS: Retrospective review of all patients who underwent transurethral resection of bladder tumor (TURBT) between 2005 and 2023. Patients with Ta disease were identified and categorized into LG, FHG, and HG. Kaplan Meier method was used to depict high-grade recurrence, T-stage progression, and radical cystectomy-free survival. RESULTS: 449 patients with Ta disease were identified (LG 48%, FHG 12%, and HG 40%). Patients with FHG (32%) had a second-look TURBT more frequently compared to LG (7%) and HG (29%) (p<0.01). They received intravesical therapy more frequently compared to LG (36% vs 20%) but lower than HG (55%) (p<0.01). They received radical cystectomy less frequently (7% compared to 20% for HG and 11% for LG, p=0.01). HG recurrence-free survival at 1, 3, and 5 years was HG (68%, 52%, and 43%), FHG (74%, 53%, and 49%), and LG (87%, 79%, and 73%) (log-rank p<0.01). T progression-free survival at 1, 3, and 5 years was HG (84%, 77%, and 70%), FHG (92%, 82%, and 82%), and LG (94%, 89%, and 85%) (log-rank p=0.02). Cystectomy-free survival at 1, 3, and 5 years was HG (92%, 84%, and 80%), FHG (96%, 94%, and 94%), and LG (99%, 95%, and 92%) (log-rank p<0.01) CONCLUSION: Patients with Ta FHG seem to behave more like Ta HG disease in terms of high-grade recurrences, but they are less likely to experience T stage progression and convert to cystectomy.

Commensal segmented filamentous bacteria-derived retinoic acid primes host defense to intestinal infection.

Interactions between the microbiota and mammalian host are essential for defense against infection, but the microbial-derived cues that mediate this relationship remain unclear. Here, we find that intestinal epithelial cell (IEC)-associated commensal bacteria, segmented filamentous bacteria (SFB), promote early protection against the pathogen Citrobacter rodentium, independent of CD4+ T cells. SFB induced histone modifications in IECs at sites enriched for retinoic acid receptor motifs, suggesting that SFB may enhance defense through retinoic acid (RA). Consistent with this, inhibiting RA signaling suppressed SFB-induced protection. Intestinal RA levels were elevated in SFB mice, despite the inhibition of mammalian RA production, indicating that SFB directly modulate RA. Interestingly, RA was produced by intestinal bacteria, and the loss of bacterial-intrinsic aldehyde dehydrogenase activity decreased the RA levels and increased infection. These data reveal RA as an unexpected microbiota-derived metabolite that primes innate defense and suggests that pre- and probiotic approaches to elevate RA could prevent or combat infections.

Microbiota Inhibit Epithelial Pathogen Adherence by Epigenetically Regulating C-Type Lectin Expression.

Numerous bacterial pathogens infect the mammalian host by initially associating with epithelial cells that line the intestinal lumen. Recent work has revealed that commensal bacteria that reside in the intestine promote defense against pathogenic infection, however whether the microbiota direct host pathways that alter pathogen adherence is not well-understood. Here, by comparing germ-free mice, we identify that the microbiota decrease bacterial pathogen adherence and dampen epithelial expression of the cell surface glycoprotein C-type lectin 2e (Clec2e). Functional studies revealed that overexpression of this lectin promotes adherence of intestinal bacterial pathogens to mammalian cells. Interestingly, microbiota-sensitive downregulation of Clec2e corresponds with decreased histone acetylation of the Clec2e gene in intestinal epithelial cells. Histone deacetylation and transcriptional regulation of Clec2e depends on expression and recruitment of the histone deacetylase HDAC3. Thus, commensal bacteria epigenetically instruct epithelial cells to decrease expression of a C-type lectin that promotes pathogen adherence, revealing a novel mechanism for how the microbiota promote innate defense against infection.

Microbiota-sensitive epigenetic signature predicts inflammation in Crohn's disease.

Altered response to the intestinal microbiota strongly associates with inflammatory bowel disease (IBD); however, how commensal microbial cues are integrated by the host during the pathogenesis of IBD is not understood. Epigenetics represents a potential mechanism that could enable intestinal microbes to modulate transcriptional output during the development of IBD. Here, we reveal a histone methylation signature of intestinal epithelial cells isolated from the terminal ilea of newly diagnosed pediatric IBD patients. Genes characterized by significant alterations in histone H3-lysine 4 trimethylation (H3K4me3) showed differential enrichment in pathways involving immunoregulation, cell survival and signaling, and metabolism. Interestingly, a large subset of these genes was epigenetically regulated by microbiota in mice and several microbiota-sensitive epigenetic targets demonstrated altered expression in IBD patients. Remarkably though, a substantial proportion of these genes exhibited H3K4me3 levels that correlated with the severity of intestinal inflammation in IBD, despite lacking significant differential expression. Collectively, these data uncover a previously unrecognized epigenetic profile of IBD that can be primed by commensal microbes and indicate sensitive targets in the epithelium that may underlie how microbiota predispose to subsequent intestinal inflammation and disease.

Disruption of Epithelial HDAC3 in Intestine Prevents Diet-Induced Obesity in Mice.

BACKGROUND & AIMS: Intestinal microbiota modulate metabolism and associate closely with epithelial cells in the intestine. In intestinal epithelial cells (IECs), histone deacetylase 3 (HDAC3) integrates microbiota-derived signals to control intestinal homeostasis. We investigated whether HDAC3 in IECs regulates metabolism and the development of obesity in mice. METHODS: Adult C57BL/6 (control) mice and mice with constitutive or inducible IEC-specific disruption of Hdac3 (HDAC3ΔIEC mice) were placed on a standard chow or high-fat diet (HFD, 60% kcal from fat). We measured body composition, weight, glucose tolerance, and energy expenditure. IECs were isolated from small intestine and gene expression, and lipid levels were analyzed. HDAC3 levels were determined in 43 pediatric patient ileal biopsy samples and compared with body weight. RESULTS: Control mice fed an HFD gained weight, became obese, and had reduced glucose tolerance with increased serum insulin, whereas HFD-fed HDAC3ΔIEC mice did not develop obesity. Serum levels of triglycerides were reduced in HDAC3ΔIEC mice, and these mice had less liver fat and smaller adipocytes, compared with HFD-fed control mice. HDAC3ΔIEC mice had similar food intake and activity as control mice, but higher energy expenditure because of increased catabolism. IECs from HDAC3ΔIEC mice had altered expression levels of genes that regulate metabolism in response to the microbiota (such as Chka, Mttp, Apoa1, and Pck1) and accumulated triglycerides compared with IECs from control mice. The microbiota-derived short-chain fatty acid butyrate was decreased in obese mice. Butyrate significantly reduced the activity of HDAC3 and increased Pck1 expression in only control IECs. Administration of butyrate to control mice with diet-induced obesity, but not HDAC3ΔIEC mice, led to significant weight loss. Disruption of HDAC3 in IECs of mice after they became obese led to weight loss and improved metabolic profile. Levels of HDAC3 in intestinal biopsy samples correlated with patient weight. CONCLUSIONS: We found that epithelial HDAC3 promotes development of diet-induced obesity in studies of mice and that butyrate reduces activity of HDAC3 in IECs to prevent diet-induced obesity. This pathway might be manipulated to prevent or reduce obesity-associated disease.