This is a little ambiguous - is this dynamic to the value set in APEX meta-data, or dynamic as a result of user events on the page?
Here is the instructions for the former:
1) Create new hidden item called P6_REGION_TITLE. I placed it on the same region as my form items.
2) Create a computation for this item Before Header, with perhaps a SQL expression like
|Region title computation|
CASE :P6_MODE WHEN 'R' THEN 'View employee' WHEN 'E' THEN 'Edit employee' END
3) Modify the region title to
When the page renders, the region title will be set relevant to the edit mode.
Here is a post how to modify the title after the page has rendered - often useful for modal dialogs or master/detail pages.