In Vivo PAkt Detection and in Silico Molecular Docking to Determine the Potential of BYL as an PI3K Inhibitor to Block Growth Signal Cascade and in Breast Cancer MCF Cell Line

Abstract

Comparison of genome between normal and breast cancer cell line shows that there are mutations across PI3Ka that probably cause breast cancer. PI3Ka is a kinase that plays a significant role in cell signalling transduction by phosphorylation cascade and produce an effect on cell. SH2 domain on PI3Ka binds to activated phosphor-tyrosine amino acids in growth factors, activating PI3Ka p110 catalytic domain, which recruits PIP2 to membrane and phosphorylates it to PIP3. This leads to cell signalling outcomes, including activation of PDK which phosphorylates Akt, cell proliferation and death. Protein/lipid phosphorylation levels are tightly controlled by phosphorylases and kinases; therefore, transduction levels can be turned on/off via altering kinases or phosphorylases and PI3K can be a target for treating breast cancer. However, we need find out which PI3K inhibitor (A66, TGX and unknown inhibitor BYL) shows that greatest potency and efficacy against PI3Ka with respect to pAkt in MCF-7 cell line. Here we show BYL has the potential to be a PI3Ka inhibitor and all of them inhibit pAkt. Using in silico technique of molecular docking, we explain that BYL shows the same amount of four hydrogen bonds as A66. By carrying out an experiment that generate a concentration-response curve, we demonstrate that BYL has the highest potency and efficacy with respect to pAkt level among the three inhibitors, greater than A66 which is known previously to be a potent and efficacy PI3Ka inhibitor. Our results demonstrate BYL and A66 show higher potency and efficacy than TGX; TGX with less hydrogen bonds between drug-protein interactions reveals lower potency and efficacy. Our assay accessed the inhibition of pAkt caused by three PI3Ka inhibitors (A66, TGX and BYL) in breast cancer cell line MCF-7 and found out that tumour derived stimulation of pAkt were responsive to all three inhibitors with BYL exhibits the greatest inhibition, followed by A66 and TGX in vivo due to different drug-protein interaction. Furthermore, PI3Ka inhibition has the potential to block growth signalling cascade in breast cancer and is a major target of anti-breast cancer development.