Matrix metalloproteinases 9 and 10 inhibit protein kinase C-potentiated, p53-mediated apoptosis.
p53, a major sensor of DNA damage, is a transcription factor that, depending on its phosphorylation status, regulates the cell cycle, DNA repair, or apoptosis. The protein kinase C (PKC) family of isozymes is also implicated in cell cycle and programmed cell death (PCD) control and has recently been shown to influence p53 function. Using three human colon adenocarcinoma cell lines SW480, EB-1, and HCT116 that either lack p53 function and were engineered to express inducible wild-type p53 (wt p53), or that constitutively express wt p53, we show that phorbol ester-mediated PKC activation potentiates p53-induced PCD. Despite the effectiveness of PKC/p53 synergy in inducing SW480 tumor cell death, however, a fraction of the cells invariably survive. To address the putative mechanisms that underlie resistance to PKC/p53-induced cell death, we generated a phorbol 12-myristate 13-acetate/p53-resistant SW480 subline and compared the gene expression profile of resistant and parental cells by DNA microarray analysis. The results of these experiments show that PKC/p53-resistant cells express a higher level of several matrix metalloproteinases (MMP), including MMP-9, MMP-10, and MMP-12, and corresponding real-time PCR assays indicate that p53 is a negative regulator of MMP-9 gene expression. Using MMP inhibitors and MMP-specific small interfering RNA, we show that MMP function confers protection from PKC/p53-induced apoptosis and identify the protective MMPs as MMP-9 and MMP-10. Taken together, these observations provide evidence that MMPs are implicated in tumor cell resistance to the synergistic proapoptotic effect of PKC and p53.
Meyer
Eric
E
Division of Experimental Pathology, Institut Universitaire de Pathologie, Université de Lausanne, Lausanne, Switzerland.
Vollmer
Jean-Yves
JY
Bovey
Raymonde
R
Stamenkovic
Ivan
I
D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology*; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000473:pathology*; D015536:Down-Regulation; D006801:Humans; D007425:Intracellular Membranes / Q000187:drug effects / Q000502:physiology; D053506:Matrix Metalloproteinase 10; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008666:Metalloendopeptidases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D010718:Phosphatidylserines / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D013752:Tetracycline / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*
D010718:Phosphatidylserines; D034741:RNA, Small Interfering; D016159:Tumor Suppressor Protein p53; D011493:Protein Kinase C; D020169:Caspases; D008666:Metalloendopeptidases; D053506:Matrix Metalloproteinase 10; D020780:Matrix Metalloproteinase 9; D013752:Tetracycline; D013755:Tetradecanoylphorbol Acetate