The REPLACE() function replaces all occurrences of a substring within a string, with a new substring.
UPDATE your_table SET your_field = REPLACE(your_field, 'articles/updates/', 'articles/news/') WHERE your_field LIKE '%articles/updates/%'
Now rows that were like
http://www.example.com/articles/updates/43
will be
http://www.example.com/articles/news/43