call into question vs challenge

call into question is not a noun while challenge is a noun.

Word	Noun	Adjective	Verb	Adverb
call into question	No	No	Yes	No
challenge	Yes	No	Yes	No

As verbs, challenge is a hypernym of call into question; that is, challenge is a word with a broader meaning than call into question:

call into question (noun)	challenge (noun)
	a call to engage in a contest or fight
	questioning a statement and demanding an explanation
	a formal objection to the selection of a particular person as a juror
	a demand by a sentry for a password or identification
	a demanding or stimulating situation

call into question (verb)	challenge (verb)
challenge the accuracy, probity, or propriety of	issue a challenge to
	take exception to
	raise a formal objection in a court of law
	ask for identification