Cell surface GRP78 activation by anti‐GRP78 autoantibodies in relation to prostate tumour growth via tissue factor activation.
Bibliographic record
Abstract
Background Prostate cancer (PC) presentation is associated with the production of anti‐GRP78 autoantibodies that enhance tissue factor (TF) expression and procoagulant activity (PCA). We and others observed that GRP78 is expressed on the surface of PC cells where it functions as a signaling receptor to promote cell proliferation and survival. Normally, GRP78 is an endoplasmic reticulum resident chaperon that ensure the proper folding of newly synthesized polypeptides. We report that binding of these autoantibodies to cell surface GRP78 PC progression in mice, mediated by TF. Further, this observed increase in tumour growth can be reversed with the use of heparin or low molecular weight heparin molecules. We hypothesize that the disruption of the autoantibody/cell surface GRP78 complex represent a viable surrogate treatment of PC. Methods Wild type, TF knockdown DU145 cells, and NOD/SCID mouse model system was used to investigate the effect of anti‐GRP78 autoantibodies on tumor growth. Protein expression was determined using western blotting and qRT‐PCR. TF activity was determined using the TF PCA continuous assay. Blood samples from patients diagnosed with PC were obtained from the Ontario Tumour Bank and St. Joseph's Hamilton. Results ‐Anti‐GRP78 autoantibodies correlate with PC stage: PC patients demonstrated high levels of anti‐GRP78 autoantibodies (60–100 μg/ml, pre‐prostatectomy stage) vs. healthy individuals (5–10 μg/ml). These titers were significantly reduced 24‐weeks post‐prostatectomy. ‐Anti‐GRP78 autoantibodies drive tumour progression: We show here that anti‐GRP78 autoantibodies activate the unfolded protein response, a pro‐survival cellular pathway in cancer cells. Furthermore, these autoantibodies were shown to accelerate tumor growth in a NOD/SCID mouse model. ‐Heparin and low molecular weight heparin abolished the effect of anti‐GRP78 autoantiboides on PC progression. In vitro : We show that heparin and low molecular weight heparin inhibit the binding of anti‐GRP78 autoantibodies. In vivo : a low molecular weight heparin was used as an intervention treatment for anti‐GRP78 autoantibodies and was shown to reverse the effect of anti‐GRP78 autoantibodies on increased tumour growth. Conclusions We have identified the function of an agent in patients' blood, anti‐GRP78 autoantibodies, that correlate with PC stage in patients and increase TF PCA and promote PC progression in mice. The effect of this autoantibody can be reversed using heparin, thus, this acts as a new potential therapeutic target for PC. Support or Funding Information This work was supported in part by Prostate Cancer Canada (PCC) Discovery Grant (Discovery Grants # 2010‐590, and D2017‐1949), and McMaster Surgical Associate Grant 176725.
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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) | 0.001 | 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".