Abstract 5436: Oct4 interaction with Hmgb2 regulates Akt signaling and the pluripotent gene expression signature.
Bibliographic record
Abstract
Abstract Akt signaling impacts multiple cellular functions associated with the hallmark characteristics of pluripotency such as cell cycle progression, cell growth, and enhanced cellular survival. Constitutive Akt activation promotes the pluripotent state and has also been implicated in several forms of cancer. Recent studies have suggested that while Akt activation may be a positive factor, the active nuclear form of Akt is associated with poor prognosis for many cancers, including lung cancer. Here, we describe a novel transcriptional regulatory feedback loop between Oct4, Hmgb2, and Akt. We show that Akt signaling promotes Oct4 phosphorylation and stability. This maintains interaction with Akt, Hmbg2 and other members of the SET complex such as Nme1 and Set. Upon differentiation, when Akt is inactive, their decreased interaction is observed. A functional genomics approach was therefore employed to determine the relevance of Oct4 interaction with Hmgb2 in maintaining the pluripotent state. Despite its previously described role in Polycomb group recruitment and transcriptional repression in Drosophila, we find that Hmgb2 knockdown results in decreased Akt signaling and decreased expression of many Oct4 transcriptional targets including genes implicated in cell cycle regulation, DNA repair, chromatin structure, as well as the pluripotency regulators Oct4, Sox2, and Nanog. Taken together, our results suggest that Oct4, Hmgb2, and the SET complex participate in a PTM-dependent feed forward regulatory loop that promotes active Akt signaling and the pluripotent gene expression signature. Future work will be focused upon dissecting the role of this network in maintaining constitutive nuclear Akt activation and promoting the primitive epigenetic state found in cancer. These findings may provide insight into the role of Akt in lung cancer chemoresistance and suggest alternate targets for more efficacious treatment. Citation Format: Pearl A. Campbell, David J. Stewart, Michael A. Rudnicki. Oct4 interaction with Hmgb2 regulates Akt signaling and the pluripotent gene expression signature. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5436. doi:10.1158/1538-7445.AM2013-5436
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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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".