Are there databases or resources that contain expression of proteins or genes before and after cancer treatment? Are there databases that contain information about gene or protein expression before and after targeted therapy or chemotherapy? 

I am curious about different cancer cell lines or cancer types. 

Any suggestion on a set of resources I should look into?
One such database/tool is “[PharmacoGx][1]: an R package for analysis of large pharmacogenomic datasets.” Bioinformatics (Oxford, England).

They brought together a large compendium of experimental data (cell lines and the like if I remember correctly from a talk), standardized these and made available within a special object class. I think there is genomic and transcriptomic data, not sure if there is proteomic data though.