Neutrophil gelatinase-associated lipocalin in gastric carcinoma cells and its induction by TPA are controlled by C/EBPβ
Bibliographic record
Abstract
Neutrophil gelatinase-associated lipocalin (NGAL) expression has been found to be upregulated in a variety of tumors, but the mechanism of NGAL elevation in gastric carcinoma remains unknown. Here, immunohistochemistry was applied to analyze NGAL expression in gastric carcinoma patients. Reverse transcription PCR, Western blot, and enzyme-linked immunosorbent assay (ELISA) were performed to evaluate NGAL mRNA and protein levels before and after 12-O-tetradecanoylphorbol-13-acetate (TPA) induction. Luciferase reporter assay was carried out to identify the core cis element in NGAL promoter. The binding ability and specificity of transcription factors were analyzed by electrophoretic mobility-shift assay (EMSA) and chromatin immunoprecipitation (ChIP), respectively. Results showed that NGAL was overexpressed in gastric tumor tissues. Gastric cancer cells treated with TPA resulted in the transactivation of NGAL promoter and the upregulation of its mRNA and protein levels. We identified the -110 to -79 sequence segment upstream from the transcription initiation site of NGAL as a TPA responsive element (TRE) and confirmed that C/EBPβ was able to bind to the -87 to -79 segment. Forced expression of C/EBPβ significantly increased the promoter activity of NGAL as well as its mRNA level. These results suggest that NGAL is overexpressed in gastric cancer, the binding of C/EBPβ to the TRE of its gene promoter mediates its TPA-induced overexpression in gastric carcinoma cells.
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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 | 0.001 |
| 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".