Newsman I sent back around unknown UK region (8)
I believe the answer is:
tyneside
'uk region' is the definition.
(region around the River Tyne in North East England)
'newsman i sent back around unknown' is the wordplay.
'newsman' becomes 'ed' (short for editor).
'back' says the letters should be written in reverse.
'around' means one lot of letters goes inside another.
'unknown' becomes 'y' (algebra).
'ed'+'i'+'sent'='edisent'
'edisent' reversed gives 'tneside'.
'tneside' placed around 'y' is 'TYNESIDE'.
(Other definitions for tyneside that I've seen before include "Geordie area" , "North-eastern region" , "This area of England" , "NE English region" , "Northeastern area" .)