RasV12 induces Survivin/AuroraB pathway conferring tumor cell apoptosis resistance.
Several cancers are treated by interferons alpha and gamma in association with conventional chemotherapy due to the resistance observed with interferon treatment alone. The frequency of un-sensitive cancer depends on tumor origin and oncogenic genes. Preclinical studies have highlighted interferon resistance in many cancers such as colon carcinoma due to oncogenic Ras. However, the resistance mechanism remains elusive. Apoptosis and proliferation of Ras(wt) and mutated Ras(V12) transformed colon carcinoma cells treated with several recombinant interferon combinations were analyzed by flow cytometer and immunoblot. Apoptotic pathways of resistant Ras(V12) cells were investigated using siRNA strategy to determine key proteins involved in this process. We show that interferons alpha and gamma synergized to induce human Ras(wt) colon carcinoma cell (HT29) apoptosis by caspases and PARP-1 cleavages in contrast to Ras(V12) mutated colon carcinoma cells (SW480, HT29 clone). However, Ras(V12) siRNA restored interferon sensitivity of Ras(V12)-HT29 clone to apoptosis. Survivin siRNA increased interferon apoptosis in Ras(wt) cells demonstrating the key role of this protein in cell survival. Ras(V12) mutation in HT29 clone neutralized the interferon effect on Survivin suppression and maintained high level of phospho-Aurora-B/Histone H3, which protected cells from apoptosis. SiRNA strategy against both Aurora-B and Survivin in Ras(V12) cells synergized to restore interferon -induced apoptosis. Ras(V12) cells are less sensitive than Ras(wt) cells to interferon induced cell apoptosis due to a Survivin/Aurora-B survival alternative pathway. Taken together, these results may provide interest in siRNA-therapeutic strategy and diagnostic relevance for therapy.
Hadj-Slimane
Réda
R
Université Paris Descartes, INSERM Unité 648, CNRS UMR 8601, Chimie et Biochimie Pharmacologique et Toxicologique, Faculté de Médecine, 45 rue des Saints-Pères, 75006 Paris, France.
Pamonsinlapatham
Perayot
P
Herbeuval
Jean-Philippe
JP
Garbay
Christiane
C
Lepelletier
Yves
Y
Raynaud
Françoise
F
D017209:Apoptosis; D064107:Aurora Kinase B; D064127:Aurora Kinases; D002277:Carcinoma / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D061945:Caspase Inhibitors; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D016898:Interferon-alpha / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009154:Mutation; D015689:Oncogene Protein p21(ras) / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D015398:Signal Transduction; D000077022:Survivin
C107489:BIRC5 protein, human; D061945:Caspase Inhibitors; D015853:Cysteine Proteinase Inhibitors; D051034:Inhibitor of Apoptosis Proteins; D016898:Interferon-alpha; D008869:Microtubule-Associated Proteins; D000077022:Survivin; D007371:Interferon-gamma; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D015689:Oncogene Protein p21(ras)