p16<sup><i>ink4a</i></sup> and retinoic acid modulate rhoA and GFAP expression during induction of a stellate phenotype in U343 MG‐A astrocytoma cells
Bibliographic record
Abstract
We previously showed that the expression of p16(ink4a) (p16), in conjunction with retinoic acid (RA) treatment in the p16-deficient astrocytoma cell line, U343 MG-A, induced a potent cell cycle arrest in G(1) associated with changes in morphology. In this study, we investigated the effects of p16 expression and RA treatment on the expression and distribution of actin, glial fibrillary acidic protein (GFAP), and vimentin within the U343 MG-A astrocytoma cytoskeleton. Changes in expression and location of the small GTPase, rhoA, were also examined after p16 expression and RA treatment. We showed that p16 expression and RA treatment led to an increase in the expression of GFAP, as well as its reorganization but that it did not significantly affect actin or vimentin expression. p16 induction in combination with RA treatment resulted in a decreased expression and activation of rhoA as determined by immunocytochemistry and Western blot analysis of soluble and insoluble fractions of cell lysates. Endogenous levels of rhoA expression varied among samples in a panel of astrocytoma cell lines as determined by Western blot analysis. Introduction of a dominant active rhoA mutant into p16-induced, RA-treated U343 MG-A astrocytoma cells was associated with the loss of long astrocytic processes and stellate morphology. These data are among the first to report the pattern of rhoA expression in human astrocytoma cell lines. They furthermore suggest that the stellate cell phenotype observed in U343 MG-A astrocytoma cells after cyclin-dependent kinase inhibitor (CKI) induction and RA treatment is accompanied by an inhibition and inactivation of rhoA in this cell system.
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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) | 0.001 | 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".