Below are examples of prior art to the 2003 p16 patent from MTM Labs...how does that patent get granted?
This answer is a "teach you how to fish" answer rather than a "I got you a fish" answer.
You can dig into this and possibly answer or at least narrow your question. The image file wrapper for this application shows that the applicant put many patents and much non-patent literature in front of the examiner and of course the examiner searched also. In fact at least one of the two references you point to:
Int J Cancer. 1995 Oct 9;63(2):226-30. CDKN2 in HPV-positive and HPV-negative cervical-carcinoma cell lines. Kelley MJ, Otterson GA, Kaye FJ, Popescu NC, Johnson BE, Dipaolo JA.
is listed on the applicant's first filed Information Disclosure Statement.
You can get all of the back and forth between the applicant and inventor at Public PAIR at the USPTO or, in the specific case of this patent, I see that google patents has a link to the PAIR data in zip form. With your knowledge of the field you may be able to see if a key reference was not considered at all.
You can download it here.