TP53 and gastric cancer: Further studies have shown that PLAB induces apoptosis via activation of c-Jun N-terminal kinase and caspase-3 in HeLa cells [12], through p53 upregulation in gastric carcinoma MGC803 cells [11], through Bcl-2 downregulation and caspase-3 activation in AGS gastric cancer cells [13], through p53 and Bax/Bcl-2 pathways in human melanoma A375-S2 cells [12] and through activation of JNK and inactivation of ERK in breast cancer MCF-7 cells [9].