Abstract 3269: Calpain knockdown in human breast carcinoma cells reduced xenograft tumor growth rates and inhibited in vitro cell migration and proliferation
Bibliographic record
Abstract
Abstract Ubiquitously expressed µ- and m-calpain are calcium dependent intracellular cysteine proteases that have been implicated in the regulation of cell proliferation, survival, apoptosis, migration, and invasion. Stable expression and proteolytic activity of the µ- and m-calpain catalytic subunits (encoded by capn1 and capn2 genes, respectively) requires a common regulatory subunit encoded by the capn4/capns1 gene; thus both µ- and m-calpain activities can be blocked by genetic knockout or knockdown of capn4 expression. Calpain is also regulated by an endogenously expressed inhibitor peptide, calpastain. We screened a panel of human breast cancer and normal epithelial cell lines for expression of calpain and calpastatin. µ- and m-calpain and calpastatin were abundantly expressed in MDA-MB-231, SKBR3, T47D, and MCF-7 breast cancer lines, as well as the normal human breast epithelial cell line MCF-10A. A stably expressed lentivirally encoded shRNA directed against the capn4 transcript was used to effectively knockdown µ- and m-calpain expression and activity in MDA-MB-231 breast cancer cells. This correlated with attenuated proliferation, migration and invasion, but resistance to anoikis. Biochemical analysis also suggests a role for calpain in the regulation of focal adhesion complex proteins such FAK, PTP-1B, talin and F-actin. Finally, knockdown of calpain in MDA-MB-231 cells significantly reduced their ability to form tumors when orthotopically injected into the mammary fat pads of nude mice. These observations provide direct genetic evidence that calpain plays a pro-tumorigenic role in the MDA-MB-231 breast cancer cell model system. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3269.
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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 | 0.001 | 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) | 0.000 | 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".