The present invention relates to a method for screening for a cancer treatment agent by contacting a test material with pancreatic adenocarcinoma upregulated factor (PAUF) and GLRX3, SNAPIN, or UBL4A, as a binding partner for PAUF, and then analyzing whether or not the test material inhibits the binding of the PAUF and GLRX3, SNAPIN, or UBL4A serving as a binding partner therefor, thereby determining that the test material is a cancer treatment agent if the binding is inhibited. The invention also relates to a pharmaceutical composition containing the test material as an active ingredient for inhibiting and treating cancer. The pharmaceutical composition of the present invention, which contains, as an active ingredient, an inhibitor for inhibiting PAUF from binding with a binding partner, effectively inhibits PAUF signaling related to the onset of cancer, thus enabling various kinds of cancer (especially pancreatic cancer) to be treated.