Melanoma and immunotherapy bridge 2015
Bibliographic record
Abstract
The PI3K/AKT/mTOR signaling pathway has been implicated in multiple cancers, and as a regulator of many key oncogenic processes. Our studies implicate a role for this pathway in resistance to both targeted and immune therapies for melanoma. Materials and methods: Melanoma cell lines and clinical specimens were utilized to study the significance and functional consequences of the PI3K/AKT/mTOR pathway. Analyses of clinical specimens were performed under institution review board-approved protocols. Results: Pilot whole genome expression profiling and synthetic lethality screens implicated oxidative phosphorylation (OxPhos) in resistance to BRAF and MEK inhibitors in BRAF-mutant human melanoma cell lines. Characterization of panels of human cell lines with de novo or acquired resistance to MAPK pathway inhibitors demonstrated that ~50 % of the cell lines exhibited a high OxPhos phenotype. The presence of high OxPhos correlated with increased expression of PGC1-alpha and with sensitivity to combined inhibition of the MAPK pathway and mTORC1/2. mTORC1/2 inhibition caused cytoplasmic sequestration of MITF and subsequent decreased expression of MITF-regulated genes, including PGC1-alpha. In vitro testing demonstrated that a direct OxPhos inhibitor similarly achieved growth inhibition and apoptosis in some human melanoma cell lines with high OxPhos. Further, the OxPhos inhibitor abrogated the growth of inhibitor-resistant BRAF mutant human melanoma cell lines in vivo. Activation of the PI3K/AKT/mTOR pathway by loss of PTEN was also shown to promote resistance to T cell mediated cell killing in vitro and in vivo. Loss of PTEN correlated with decreased CD8 cell infiltrates in clinical specimens and increased expression of immunosuppressive cytokines. While pan-PI3K inhibitors inhibited immune cell viability and function, isoform-selective inhibitors did not significantly affect immune function and they produced synergy with immunotherapy. Conclusions: The PI3K/AKT/mTOR signaling pathway is an important regulator of key cellular processes in melanoma, and should be considered as a candidate combinatorial partner for both targeted and immune therapies.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 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) | 0.005 | 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 teacher head, 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".