UPDATE `content` SET `title` = REPLACE( `title`, '<a href="telnet://*">', '' ) ;
SELECT CONCAT(SUBSTRING_INDEX(withLink,'<', 1), REPLACE(SUBSTRING_INDEX(withLink,'>', -2),'</a>','')) as withoutLink FROM ...
-- for testing
SELECT 'something <a href="telnet://192.168.1.1">some text</a> dasdsdgdfg' as withLink, (SELECT CONCAT(SUBSTRING_INDEX(withLink,'<', 1), REPLACE(SUBSTRING_INDEX(withLink,'>', -2),'</a>',''))) as withoutLink