I need to use validated PPI data in my research. Is there any database of such validated (like Mass Spectrometry) database for cancer?
One of the most popular databases of PPI data is STRING. It is not only for cancer though, but since many research is done in the field of cancer, you will find a lot of data derived from cancer research.
This site provides a platform to facilitate discovery of new mechanisms to control tumorigenesis through the integration of genomic, pharmacological, clinical, and structural data with the network of cancer-associated protein-protein interactions experimentally detected in cancer cells.
Li et al. (2017) The OncoPPi network of cancer-focused protein-protein interactions to inform biological insights and therapeutic strategies. Nat Commun 16: 14356.