SET @id = 1;

SELECT news.*
FROM news, cats
WHERE (news.cat_id = cats.cat_id AND
        (
            ((SELECT cats.cat_id FROM cats WHERE cats.cat_id = @id) = cats.cat_id) OR
            ((SELECT cats.subcat_to FROM cats WHERE cats.cat_id = @id) = cats.cat_id) OR
            ((SELECT cats.subsubcat_to FROM cats WHERE cats.cat_id = @id) = cats.cat_id)
        )
    )