The Effect of <i>p53</i> Status on Radio-Sensitivity of Quiescent Tumor Cell Population Irradiated With γ-Rays at Various Dose Rates
Bibliographic record
Abstract
Background: The aim of the study was to clarify the effect of p53 status of tumor cells on radio-sensitivity of solid tumors following Gamma-ray irradiation at various dose rates, referring to the response of intratumor quiescent (Q) cells. Methods: Human head and neck squamous cell carcinoma cells transfected with mutant TP53 (SAS/ mp53 ) or with neo vector (SAS/ neo ) were injected subcutaneously into hind legs of nude mice. Tumor bearing mice received 5-bromo- 2’ -deoxyuridine (BrdU) continuously to label all intratumor proliferating (P) cells. They received gamma-rays at a high, middle or low dose rate. Immediately or 9 h after the high dose-rate irradiation (HDR, 2.5 Gy/min), or immediately after the middle (MDR, 0.039 Gy/min) or low (LDR, 0.00098 Gy/min) dose-rate irradiation, the tumor cells were isolated and incubated with a cytokinesis blocker, and the micronucleus (MN) frequency in cells without BrdU labeling (Q cells) was determined using immunofluorescence staining for BrdU. Results: Following Gamma-ray irradiation, SAS/ neo tumor cells, especially intratumor Q cells, showed a marked reduction in sensitivity due to the recovery from radiation-induced damage, compared with the total or Q cells within SAS/ mp53 tumors that showed little repair capacity. The recovery capacities following γ-ray irradiation were greater in Q than total cell population and increased in the following order of 9 h after HDR < MDR < LDR. Thus, the difference in radio-sensitivity between the total (P + Q) and Q cells after gamma-ray irradiation increased in the same order. Conclusion: To secure controlling solid tumors as a whole, difference in sensitivity between total and Q tumor cells especially in solid tumors irrespective of p53 status has to be suppressed as irradiation dose rate decreases, for instance, through employing combined method for enhancing the response of Q tumor cells. J Clin Med Res. 2018;10(11):815-821 doi: https://doi.org/10.14740/jocmr3610w
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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) | 0.002 | 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".