Zinc Depletion‐induced Apoptosis in Human Breast Cancer MDA‐MB‐231 Cells Is Calcium‐dependent
Bibliographic record
Abstract
We have previously observed an association between zinc depletion‐induced apoptosis and an elevated expression of eNOS in MDA‐MB‐231 cells. Since eNOS is sensitive to changes in intracellular [Ca 2+ ] i , we hypothesized that zinc depletion‐induced apoptosis is calcium‐dependent. To test this hypothesis, MDA‐MB‐231 cells were cultured in DMEM supplemented with FBS (10%) for 3 days. Zinc depletion was achieved by incubating the cells with TPEN (0 or 20 μM) for 0–6 h. Zinc depletion resulted in a sustained elevation in intracellular calcium level after 3 h and a 20‐fold increase in caspase‐3 activity at 6 h ( p < 0.05). Chelating intracellular Ca 2+ with BAPTA‐AM (10–50 μM) reduced caspase‐3 activity by 82%–96% ( p < 0.05). Further, zinc depletion also resulted in a 2‐fold increase in mitochondrial superoxide level ( p < 0.05). Blocking mitochondria calcium transport with Ruthenium red (25 μM) reduced caspase‐3 activity by 50% ( p < 0.05). Inhibiting intracellular Ca 2+ channel with 2‐APB (50–150 μM) and U‐73122 (2–20 μM) reduced caspase‐3 activity by 30–50% and 20–70%, respectively ( p < 0.05). In summary, these results showed that zinc depletion altered cellular calcium homeostasis resulting in an elevated intracellular calcium level required for apoptosis in MDA‐MB‐231 cells. ( Supported by NSERC ).
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| 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".