We observed that melanoma PDXs resistant to CDK4/6i frequently displayed activation of the phosphatidylinositol 3-kinase (PI3K)-AKT pathway, and inhibition of this pathway improved CDK4/6i response in a p21-dependent manner.
Functional analyses of differentially expressed genes (DEGs), obtained from the GEO (Gene Expression Omnibus) database, indicated that high proliferative and metastatic abilities are the main characteristics of melanoma and that the PI3K and MAPK pathways play essential roles in melanoma progression.
Mutations in EGFR, KRAS, BRAF, and PIK3CA genes are widely analyzed in solid tumors such as lung cancer, colorectal cancer, breast cancer, and melanoma.
Collectively, our results indicated that Lyn plays a carcinogenic role in multiple cellular functions during melanoma development through regulating apoptosis and autophagy via the PI3K/Akt pathway and may be a valuable potential target for the clinical treatment of melanoma.
In conclusion, our study demonstrated that SCH-527123, a small-molecule antagonist for CXCR1 and CXCR2 inhibited cell proliferation, migration and invasion in melanoma via PI3K/AKT pathway.
Here, we show that constitutive activation of the small GTPase ARF6 (ARF6<sup>Q67L</sup>) is sufficient to accelerate metastasis in mice with BRAF<sup>V600E</sup>/Cdkn2a<sup>NULL</sup> melanoma at a similar incidence and severity to <i>Pten</i> loss, a major driver of PI3K activation and melanoma metastasis.
In this analysis BRAF, KIT, NRAS, and PIK3CA mutations were examined by next generation sequencing (NGS) in 446 melanomas in a clinical diagnostic setting.
The mitogen‑activated protein kinase (MAPK) pathway, phosphoinositol‑3‑kinase (PI3K) pathway promote the development of melanoma through numerous genomic alterations on different components of these pathways.
Somatic alterations sequentially induced mitogen-activated protein kinase (MAPK) pathway activation, upregulation of telomerase, modulation of the chromatin landscape, G1/S checkpoint override, ramp-up of MAPK signaling, disruption of the p53 pathway, and activation of the PI3K pathway; no mutations were specifically associated with metastatic progression, as these pathways were perturbed during the evolution of primary melanomas.
In this study, we found that Ashitaba (<i>Angelica keiskei</i>) chalcones, 4-hydroxyderricin (4HD) and xanthoangelol (XAG), suppressed melanoma development by directly targeting both BRAFV600E and PI3K, which blocked the activation of downstream signaling.
Although PI3K inhibition resulted in cytostatic effects on xenografted NRAS<sup>Q61H</sup> /PIK3CA<sup>H1047R</sup> melanoma, combined inhibition of MEK1/2 plus PI3K elicited significant melanoma regression.
These results demonstrate that the combination of HSP90 and PI3K/mTOR inhibitors could be an effective therapeutic strategy that target the main survival pathways in melanoma and must be considered to overcome resistance to BRAF inhibitors in melanoma patients.
Our data indicate that in mucosal melanomas RAS/NF1 alterations are frequent, implying a significant pathogenetic role for MAPK and potentially PI3K pathway activation in these tumors.
Finally, we describe findings of high translational significance by demonstrating that Abl/Arg cooperate with PI3K/Akt/PTEN, a parallel pathway that is associated with intrinsic resistance to BRAFi and immunotherapy, as Abl/Arg and Akt inhibitors cooperate to prevent viability, cell cycle progression and in vivo growth of melanomas harboring mutant BRAF/PTEN.