Abstract A010: Assay development to assess the efficiency and stability of candidate molecules for transcriptional gene silencing of FOXP3, using a human tumor-derived cell line
Bibliographic record
Abstract
Abstract Regulatory T cells play an important role to modulate the balance between immunotolerance and immunosurveillance. These cells have the property of inhibiting effector lymphocytes and may antagonize antitumor immunity. Regulatory T cells are originated in the thymus, or even converted from peripheral lymphocytes by factors produced in the tumor microenvironment. Clinical data suggests that regulatory T cell infiltration correlates with poor prognosis in the treatment of solid tumors. The FOXP3 transcription factor is considered a master key to control the phenotype of regulatory T cells. It was previously shown, that the ectopic expression of FOXP3 can induce an immunosuppressive phenotype in lymphocytes. In contrast, it has been observed that mutations in the FOXP3 gene can cause impaired immunosuppressive activity mediated by regulatory T cells, such as the autoimmunity syndrome known as IPEX. In this sense, the FOXP3 transcription factor may be an interesting target, looking for inactivation of the immunosuppressive phenotype of regulatory T cells, to potentiate antitumor response. In this work, we present an assay development to investigate the potential of transcriptional interference RNA candidates to silence FOXP3 expression. In contrast to post-transcriptional gene silencing method, which targets messenger RNA and depends on a constant supply or efficient turn-over of the inhibitory molecule, the transcriptional gene silencing targets the cellular DNA genome, inducing epigenetic changes that may control the target gene transcription. We employed the human MCF-7 tumor cell line, which has endogenous and constitutive expression of FOXP3 as a target model to test transcriptional gene silencing candidates. This cell line is transduced with lentiviral vectors harboring interfering RNA sequences driven to the FOXP3 promoter region. The RNA interference candidates are then evaluated for their ability to induce DNA methylation, by bisulfite method, and transcriptional gene silencing of FOXP3, by qPCR. We performed the screening of candidates for FOXP3 transcriptional silencing, in comparison to a post-transcriptional interference RNA control. The lentiviral transduced cells are easily expanded and allow a temporal analysis of target gene expression. In this model, we observed the possibility of finding transcriptional interference RNA candidates that exhibited high efficiency and stability, that may be used for research purposes, or even for the investigation of new therapeutic possibilities in immuno-oncology. Citation Format: Carolinne T Fogagnolo, Daniela S Mizobuti, Marcio C Bajgelman. Assay development to assess the efficiency and stability of candidate molecules for transcriptional gene silencing of FOXP3, using a human tumor-derived cell line [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr A010.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".