Do you know of any databases or research articles that measure changes in gene expression following an si- or sh-RNA perturbation on transcription factors?

One source I could find is Fantom4, where 52 transcription factors were knocked down in the THP-1 cell line and expression was measured afterwards. This is, however, only one cell line.

Another approach could be to search GEO/ArrayExpress for the keywords, but there were (a) surprisingly few results for a given well-known TF and (b) fantom4 data was for instance not deposited there.