No. There is only one way to pronounce "PNAS" (other than spelling it), and it sounds exactly like "penis". Not "cock", "dong", "member", "wang", or any other arguably childish euphemism. It sounds exactly like the proper English noun for male genitalia.

And this has nothing to do with you me or the parent thinking it sounds like "penis". EVERYBODY WE TALK TO will think we're saying "penis". Believe me, I get this enough with Coq (the theorem prover) and "cock"'s merely slang.