Abstract 5507: Investigation of the effects of alterations in the glutamate receptor, GRIK2 on osteosarcoma tumorigenesis
Bibliographic record
Abstract
Abstract Osteosarcoma is a primary, malignant bone tumour mainly affecting young adults with a five-year survival rate of 60-70% depending on presentation of metastasis at diagnosis. Tumours are marked by genetic instability and heterogeneity and for this reason, molecular subtypes have yet to be characterized. Survival rates have remained consistent over the past few decades and novel molecular targets for treatment are needed. Current genomic strategies have identified recurrent copy number alterations. In a study of 44 flash frozen osteosarcoma tumours which were obtained at the time of biopsy and 25 blood-matched samples we identified recurrent copy number losses including a region at 6q16.3 in 14% of tumours. Focal deletions were observed in the 5’ intergenic space and first intron of the GRIK2 gene and do not overlap with any coding sequence. The relationship between alterations in this region and osteosarcoma tumourigenesis has yet to be explored in depth. GRIK2 encodes an ionotropic glutamate receptor that has been implicated as a tumour suppressor in gastric cancer. An interesting feature of the tumours was the overlap of focal deletions with a SETDB1 histone methyltransferase binding site indicating a potential connection with epigenetic regulation of GRIK2. The goal of this study is to examine the effects of non-coding, focal deletions on GRIK2 gene expression, function and regulation in osteosarcoma cells. GRIK2 transcript levels were measured in osteosarcoma tumours and cell lines using qRT-PCR. Functional assays were performed to characterize the role of GRIK2 in osteosarcoma cell proliferation, migration and apoptosis in vitro. Gene editing with CRISPR/cas9 was performed to examine the link between non-coding deletions and GRIK2 expression. GRIK2 transcript levels varied in tumours; several tumours with focal deletions had increased transcript levels relative to cell lines which demonstrated low expression levels. Due to the observation of low transcript levels, a gain of function approach was employed to examine GRIK2 function in vitro. Overexpression of GRIK2 decreased proliferation, migration and increased apoptosis in osteosarcoma cells. Gene editing of the SETDB1 binding site resulted in increased GRIK2 transcript levels relative to untreated cells. This study suggests that non-coding focal deletions are linked to high expression levels of GRIK2 which may confer a less aggressive phenotype and are involved in epigenetic regulation of the gene. Citation Format: Justin G. Mayers, Nalan Gokgoz, Jay S. Wunder, Irene L. Andrulis. Investigation of the effects of alterations in the glutamate receptor, GRIK2 on osteosarcoma tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5507. doi:10.1158/1538-7445.AM2017-5507
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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".