Abstract LB-435: Double-blind randomized clinical trial of vitamin D3 showing effects on tissue calcitriol levels, gene expression and proliferation immunohistochemistry in prostate cancer
Bibliographic record
Abstract
Abstract Background: Preclinical data suggest that vitamin D plays a favourable role in prostate cancer prevention and prognosis, but its putative anticancer effects have not been validated in clinical prostate tissue samples. Here, we report the results from a randomized clinical trial (RCT). Objectives: We conducted an RCT to determine whether simple cholecalciferol (vitamin D3) consumed orally elicits effects on prostate cancer pathology in prostate tissue obtained at surgery. Methods: Prostate cancer patients (n=66) with Gleason scores 6 or 7 and scheduled for radical prostatectomy were randomized to daily vitamin D doses of 400, 10,000, or 40,000 IU for 3-8 wk before surgery. Results: Laser-capture microdissected paraffin-embedded prostate tissue showed differential expression, between benign and cancerous regions, for the cancer-related mRNAs and miRNAs, as well as for the Ki-67 proliferation marker (p0.07 among groups). The group consuming 40,000 IU/d vitamin D exhibited the highest levels of both calcitriol and its precursor as measured in frozen prostate tissue and in serum (p<0.02 each). Prostate tissue calcitriol correlated strongly with the expression of androgen receptor mRNA (r = -0.58, p=0.001), NKX3.1 mRNA (r = -0.39, p=0.02), miR-100 (r = 0.44, p=0.01), miR-125b (r = 0.37, p=0.03), Let-7a (r = 0.47, p=0.03), miR-141 (r = 0.51, p=0.002), miR-106b (r = 0.45, p=0.01), and miR-331-3p (r = 0.47, p=0.005). Automated digital analysis of immunohistochemically stained prostate cancer regions showed that prostate tissue calcitriol related negatively with Ki67 intensity (r = -0.38, p =0.02) and percent of nuclei stained strongly positive (3+) for Ki67 (r = -0.41, p=0.008). A threshold effect was evident such that patients at the highest quartile of prostate tissue calcitriol (≥ 37 pmol/kg) had significantly lower AR mRNA (p<0.001), NKX3.1 mRNA (p=0.01), and Ki67 measures (p<0.05), as well as higher levels of the correlated miRNAs (p<0.05), compared to those with lower levels. Conclusions: We provide level-1 clinical evidence that higher oral vitamin D doses produce higher levels of calcitriol within prostate tissue, and that higher prostate calcitriol relates to lower androgen receptor mRNA, higher miRNA signalling, and diminished expression of the proliferation marker Ki67 in prostate cancer. These RCT results justify a need to explore strategies that may maximize calcitriol within prostate for cancer chemoprevention. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-435. doi:1538-7445.AM2012-LB-435
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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 | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.005 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.014 | 0.001 |
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".