Abstract A029 Investigating the role of environmental toxicant exposures and STAG2 loss in sarcomagenesis
Bibliographic record
Abstract
Abstract Humans are exposed to a variety of environmental toxicants which have been implicated in contributing to cancer development. A possible explanation for this link is that adaptive epigenetic changes occur in stem cell populations upon toxicant exposure. These cells are particularly vulnerable during developmental stages, leading to abnormal gene expression later in life. Environmental exposures have been associated with the initiation of sarcoma development. This study will focus on Ewing Sarcoma (ES), as this malignancy has a low mutational burden relative to other cancer types and is thought to be linked to agricultural chemicals. We are also focusing on stromal antigen 2 (STAG2), which is found to be frequently mutated in ES in addition to multiple other tumor types. Patients with STAG2-mutated ES have higher rates of metastatic disease and worse outcomes, but the reason for this remains poorly understood. STAG2 plays a role in the regulation of genomic organization, DNA repair, and modulation of replication stress (RS). It has also been shown that STAG2 loss may lead to dysregulation of the cGAS-STING pathway, which is critical for tumor immunosurveillance. We are testing the effects of environmental toxicants in mesenchymal stem cells (MSCs), the putative cell of origin for ES and many other sarcomas. We have successfully used CRISPR/Cas9 to generate STAG2 knockout MSCs. With this model, we are testing the effects of STAG2 loss and toxicant exposure on levels of RS, epigenomic instability, and innate immune suppression in MSCs. Our results indicate that these toxicants alter the cell cycle dynamics of MSCs, and that these alterations change depending on STAG2 status. We have also observed changes in the DNA damage response of STAG2-mutant MSCs when exposed to environmental toxicants. Interestingly, effects were seen even at sub-lethal doses that may reflect common, low-level exposures. We believe that our data will contribute to the understanding of the mechanism by which environmental toxicants facilitate malignant transformation of Ewing sarcoma and other pediatric sarcomas. Citation Format: Rachael Kohrn, Joyce Ohm. Investigating the role of environmental toxicant exposures and STAG2 loss in sarcomagenesis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pediatric Cancer Research; 2024 Sep 5-8; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl):Abstract nr A029.
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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 | 0.001 | 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) | 0.005 | 0.001 |
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".