Melanoma specific killing was in the order; ZnO > B4C ≥ Cu > MgO > Co3O4 > Fe2O3 > NiO, ZnO-NP inhibiting B16F10 and A375 cells as well as ERK enzyme (>90%) and several other cancer-associated kinases (AKT, CREB, p70S6K).
Activated PI3K-AKT pathway may contribute to decrease sensitivity to inhibitors of key pathogenetic effectors (mutated BRAF, active NRAS or MEK) in melanoma.
Although the classic RAS-RAF-MEK pathway is thought to be the main pathway involved in melanoma pathogenesis, genetic alterations in the phosphatidylinositol 3-kinase-AKT pathway, including PTEN-regulated signaling, are also thought to contribute.
CDKL1 is a member of the cell division cycle 2 (CDC2)-related serine threonine protein kinase family and is overexpressed in malignant tumors such as melanoma, breast cancer, and gastric cancer.
Finally, use of inhibitors to target downstream signaling through mitogen-activated protein kinase kinase and phosphatidylinositol 3-OH kinase or AKT are now entering clinical trials, and if these combinations can be safely delivered at sufficient dose to inhibit the targets, there is significant potential to target NRAS mutant melanoma.
Further studies in melanoma cultures and mouse xenografts showed that fisetin-mediated growth inhibition was associated with dephosphorylation of AKT, mTOR and p70S6K proteins.
Furthermore, the results showed that the mRNA and protein expression levels of AKT1 were downregulated in the melanoma cell lines when miR429 was overexpressed according to qRT-PCR and western bolt, indicating MicroRNA-429 may directly target AKT1 in melanoma.
Furthermore, we found that RGS1 may promote melanoma progression through the downstream effects of Gαs signaling, such as the increased phosphorylation of AKT and ERK by western blotting.
Given that p53 is capable of antagonising PI3K/AKT activation we hypothesised that pharmacological restoration of p53 activity may increase the sensitivity of BRAF-mutant melanoma to MAPK-targeted therapy and eventually delay and/or prevent acquisition of drug resistance.
Herein, we examined whether targeting the RAS-RAF-MEK-ERK pathway with the RAF inhibitor sorafenib and/or the PI3K-AKT-mTOR pathway with the mTOR inhibitor rapamycin has therapeutic effects against melanoma.
Identification of mutations in the gene encoding the serine/threonine-protein kinase, BRAF, and constitutive activation of the mitogen-activated protein kinase (MAPK) pathway in around 50% of malignant melanomas have led to the development and regulatory approval of targeted pathway inhibitor drugs.