SQL (MySQL): Match first letter of any word in a string?

SELECT * FROM `articles` WHERE `body` REGEXP '[[:<:]][acgj]'

SELECT
  StringCol
FROM
  MyTable
WHERE
  ' ' + StringCol LIKE '% ' + MyLetterParam + '%'

'[acgj]'

WHERE
  ' ' + StringCol LIKE '%['+' '+CHAR(9)+CHAR(10)+CHAR(13)+CHAR(160)+'][acgj]%'