IGF1R/IR Mediates Resistance to BRAF and MEK Inhibitors in BRAF-Mutant Melanoma

Patel, Hima; Mishra, Rosalin; Yacoub, Nour; Alanazi, Samar; Kilroy, Mary Kate; Garrett, Joan T.

doi:10.3390/cancers13225863

Cited by 19 publications

(16 citation statements)

References 63 publications

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“…6 A–C). IGF1R [ 52 ], RIPK1 [ 53 ], and PSEN2 [ 54 ] are already known to contribute to vemurafenib resistance, suggesting that our new analysis method using v reliably identified hits whose ablation can sensitize melanoma to vemurafenib. We similarly used FC and v values as input for the DrugZ analysis [ 55 ] (Fig.…”

Section: Resultsmentioning

confidence: 99%

Efficient prioritization of CRISPR screen hits by accounting for targeting efficiency of guide RNA

et al. 2023

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Background CRISPR-based screens are revolutionizing drug discovery as tools to identify genes whose ablation induces a phenotype of interest. For instance, CRISPR-Cas9 screening has been successfully used to identify novel therapeutic targets in cancer where disruption of genes leads to decreased viability of malignant cells. However, low-activity guide RNAs may give rise to variable changes in phenotype, preventing easy identification of hits and leading to false negative results. Therefore, correcting the effects of bias due to differences in guide RNA efficiency in CRISPR screening data can improve the efficiency of prioritizing hits for further validation. Here, we developed an approach to identify hits from negative CRISPR screens by correcting the fold changes (FC) in gRNA frequency by the actual, observed frequency of indel mutations generated by gRNA. Results Each gRNA was coupled with the “reporter sequence” that can be targeted by the same gRNA so that the frequency of mutations in the reporter sequence can be used as a proxy for the endogenous target gene. The measured gRNA activity was used to correct the FC. We identified indel generation efficiency as the dominant factor contributing significant bias to screening results, and our method significantly removed such bias and was better at identifying essential genes when compared to conventional fold change analysis. We successfully applied our gRNA activity data to previously published gRNA screening data, and identified novel genes whose ablation could synergize with vemurafenib in the A375 melanoma cell line. Our method identified nicotinamide N-methyltransferase, lactate dehydrogenase B, and polypyrimidine tract-binding protein 1 as synergistic targets whose ablation sensitized A375 cells to vemurafenib. Conclusions We identified the variations in target cleavage efficiency, even in optimized sgRNA libraries, that pose a strong bias in phenotype and developed an analysis method that corrects phenotype score by the measured differences in the targeting efficiency among sgRNAs. Collectively, we expect that our new analysis method will more accurately identify genes that confer the phenotype of interest.

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Section: Resultsmentioning

confidence: 99%

Efficient prioritization of CRISPR screen hits by accounting for targeting efficiency of guide RNA

et al. 2023

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“…TDR cells were generated as previously described [10]. A375 cells were cultured in Dulbecco’s Modified Eagle Medium (cat# MT15017CV; Corning, New York, USA); WM115 cells were cultured in MEM (cat# MT10009CV; Corning); WM983B cells were cultured in RPMI-1640 medium (cat# MT10040CM; Corning) supplemented with 10% (vol/vol) fetal bovine serum (FBS) (cat# 89510-188; VWR) and 1% penicillin–streptomycin solution 100× (cat# 30-002-CI; Corning).…”

Section: Methodsmentioning

confidence: 99%

RIDR-PI-103, ROS-activated prodrug PI3K inhibitor inhibits cell growth and impairs the PI3K/Akt pathway in BRAF and MEK inhibitor-resistant BRAF-mutant melanoma cells

et al. 2023

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Reactive oxygen species (ROS) levels are elevated after acquisition of resistance to v-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors including dabrafenib and MEK inhibitors such as trametinib in BRAF-mutant melanoma. To circumvent toxicity to PI-103 (a pan PI3K inhibitor), we utilized a novel ROS-induced drug release (RIDR)-PI-103, with a self-cyclizing moiety linked to PI-103. Under high ROS conditions, RIDR-PI-103 releases PI-103, which inhibits conversion of phosphatidylinositol 4,5-bisphosphate (PIP2) to phosphatidylinositol 3,4,5-triphosphate (PIP3). Previous findings demonstrate that trametinib and dabrafenib-resistant (TDR) cells maintain p-Akt levels compared to parental counterparts and have significantly higher ROS. This is a rationale to explore the efficacy RIDR-PI-103 in TDR cells. We tested the effect of RIDR-PI-103 on melanocytes and TDR cells. RIDR-PI-103 exhibited less toxicity compared to PI-103 at 5 µM in melanocytes. RIDR-PI-103 significantly inhibited TDR cell proliferation at 5 and 10 µM. Twenty-four hour treatment with RIDR-PI-103 inhibited p-Akt, p-S6 (Ser240/244) and p-S6 (Ser235/236). We assessed the mechanism of activation of RIDR-PI-103, using glutathione or t-butyl hydrogen peroxide (TBHP) on the TDR cells in the presence or absence of RIDR-PI-103. Addition of the ROS scavenger glutathione to RIDR-PI-103 significantly rescued the cell proliferation in TDR cell lines while addition of the ROS inducer TBHP and RIDR-PI-103 inhibited cell proliferation in WM115 and WM983B TDR cell lines. Examining the efficacy of RIDR-PI-103 on BRAF and MEK inhibitor-resistant cells will expand possible treatment options and open avenues for the development of new ROS-based treatment therapies for BRAF-mutant melanoma patients.

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“…EGFR activation binds to specific tyrosine residues on the receptor and results in a conformation change of Sos protein, thereby recruiting and activating RAS-GDP, and finally ERK activation induces cell proliferation ( 96 ). Besides, the upregulation of IGF1R/IR in BRAF and MEK inhibitor resistant cells and the maintenance of P-ERK and P-Akt suggest that IGF1R/IR may mediate resistance to inhibitors through the reactivation of MAPK ( 97 ).…”

Section: The Evolution Of Braf Activationmentioning

confidence: 99%

The Evolution of BRAF Activation in Non-Small-Cell Lung Cancer

et al. 2022

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Non-small-cell lung cancer (NSCLC) is the most common subtype of lung cancer, of which approximate 4% had BRAF activation, with an option for targeted therapy. BRAF activation comprises of V600 and non-V600 mutations, fusion, rearrangement, in-frame deletions, insertions, and co-mutations. In addition, BRAF primary activation and secondary activation presents with different biological phenotypes, medical senses and subsequent treatments. BRAF primary activation plays a critical role in proliferation and metastasis as a driver gene of NSCLC, while secondary activation mediates acquired resistance to other targeted therapy, especially for epidermal growth factor tyrosine kinase inhibitor (EGFR-TKI). Treatment options for different activation of BRAF are diverse. Targeted therapy, especially two-drug combination therapy, is an important option. Besides, immune checkpoint inhibitors (ICIs) would be another option since BRAF activation would be a positive biomarker of tumor response of ICIs therapy. To date, no high level evidences support targeted therapy or immunotherapy as prioritized recommendation. After targeted therapy, the evolution of BRAF includes the activation of the upstream, downstream and bypass pathways of BRAF. In this review, therapeutic modalities and post-therapeutic evolutionary pathways of BRAF are discussed, and future research directions are also provided.

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IGF1R/IR Mediates Resistance to BRAF and MEK Inhibitors in BRAF-Mutant Melanoma

Cited by 19 publications

References 63 publications

Efficient prioritization of CRISPR screen hits by accounting for targeting efficiency of guide RNA

Efficient prioritization of CRISPR screen hits by accounting for targeting efficiency of guide RNA

RIDR-PI-103, ROS-activated prodrug PI3K inhibitor inhibits cell growth and impairs the PI3K/Akt pathway in BRAF and MEK inhibitor-resistant BRAF-mutant melanoma cells

The Evolution of BRAF Activation in Non-Small-Cell Lung Cancer

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