Check our recent publication introducing an improved Cas9-based method for silencing of long non-coding RNA genes:

'Cas9-mediated excision of proximal DNaseI/H3K4me3 signatures conferse robust silencing of microRNA and long non-coding RNA genes'

Janga H, Aznaourova M, Boldt F, Damm K, Grünweller A, Schulte LN

https://doi.org/10.1371/journal.pone.0193066