MDM2 and cancer: PNC-27-HDM-2 Complexes occur in Pores in the Plasma Membranes of Cancer Cells. To determine further if PNC-27 occurs in complexes with HDM-2 in transmembrane pores, we performed the same experiment as in Figure 3A, except that the PNC-27 treatment was reduced to 3 min and we also labeled HDM-2 with a 15 nm gold-labeled antibody.