Abstract 3091: Relevance of iNOS expression in bladder cancer stem cells
Bibliographic record
Abstract
Abstract Background: Bladder cancer (BC) is one of the most common tumors of the male urogenital tract and an important worldwide cause of death. Increasing evidence has indicated the presence of cancer stem cells (CSCs) in many types of tumors, associated with aggressiveness, chemoresistance and relapse. The expression of inducible nitric oxide (NO) synthase (iNOS) in human BC is a poor prognostic factor associated with increased invasion and tumor recurrence. Although there is evidence supporting the role of NO/iNOS in the promotion and progression of BC, the possibility that there are CSCs dependent on endogenous NO generation was not yet been clearly defined. In this study we evaluate the role of NO in CSC maintenance, modulating its production, using pharmacological inhibitors or silencing iNOS expression in a murine BC model. Also, we analyzed the correlation between iNOS expression and stemness-related genes (SG) in human BC samples with different invasion grades. Methods: iNOS pharmacological inhibitors (pan-NOS or iNOS specific) or shRNA were used on murine BC model with different iNOS expression and invasiveness grade: MB49 [iNOS+, non-muscle invasive (NMI)] and MB49-I [iNOS++, muscle invasive (MI)], in order to analyze cell proliferation, number of CSC determined as spheres forming efficiency (SFE) and SG (Sox 2, Oct4 and Nanog expression) by qPCR. iNOS expression and SG were also analyzed in human BC samples (16 NMI low grade (LG), 10 NMI high grade (HG) and 17 MI). Results: The number of CSCs was higher in MB49-I than NMI MB49 line (p<0.05), in concordance with the higher expression of iNOS and Sox2, Oct4 and Nanog (p<0.001). iNOS inhibition diminished CSC in both cell lines (p<0.05 vs MB49; p<0.001 vs MB49-I). Inhibition of SG was only observed in MB49-I line (p<0.05). Moreover, the reduction of CSC and SG were more evident in MB49-I-shiNOS (p<0.0001 vs MB49-I scr; p<0.001 vs MB49-I-scr). The in vivo tumorigenic potential of cells derived from MB49-I spheres were higher than the cells growing in monolayers. MB49-I spheres cells treated with iNOS inhibitors did not developed tumors in vivo. Furthermore, MB49-I shiNOS spheres showed an incipient growth and regressed about 5 weeks post inoculation, in correlation with low iNOS and SG expression. Regarding human samples, iNOS was expressed in 78% of MI, 55% HG and 50% LGNMI (p<0.05 vs NMI). SG expression were significantly higher in MI than in NMI LG. Sox2 was expressed 82% in MI, 25% LG and 40% HG in NMI (p=0.0002). 76% of MI samples were positive for Nanog and Oct4 (p<0.05 vs NMI LG). A positive correlation between iNOS and SG expression was found (sox2: p<0.0001; Oct4: p<0.0001 and Nanog: p<0.05). Conclusion: Together, this results show that iNOS plays an important role in maintenance of CSC and in vivo BC growth by regulating stemness and self-renewal ability. Thus, iNOS identification and inhibition could be a potential target to eradicate CSC, responsible for tumor recurrences. Citation Format: Denise Belgorosky, Yanina Langle, Julie Girouard, Jovane Hamelin-Morrissette, Lina Marino, Eduardo I. Agüero, Héctor Malagrino, Carlos Reyes-Moreno, Ana M. Eiján. Relevance of iNOS expression in bladder cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3091.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".