Demonstrate concern for the entertainment industry (4,8)
I believe the answer is:
show business
'the entertainment industry' is the definition.
('show business' can be a synonym of 'entertainment industry')
'demonstrate concern' is the wordplay.
'demonstrate' becomes 'show' ('show' can be a synonym of 'demonstrate').
'concern' becomes 'business' (business is a kind of concern**).
'show'+'business'='SHOW-BUSINESS'
'for' is the link.
(Other definitions for show business that I've seen before include "Entertainment industry" , "The world of entertainment" , "Theatre/music industry" .)