IKBKE, NFkB and HIF1A Activation in TLR-9 Invasive Ductal Carcinomas: Relationship with Epithelio-Mesenchymal Transition
D Meseure, F Lerebours, K Drak-Alsibai, M Trassard, V Suciu, C Andre, C Le Ray, S Vacher, R Lidereau, JM Guinebretiere, I Bieche. Centre Rene Huguenin, St Cloud, France; Institut Andre Godinot, Reims, France
Background: TLR-9, a pattern recognition receptor (PRR) first identified in innate/adaptative immunity, recognizes motifs of DNA and RNA released by necrotic/apoptotic cells.TLR-9 also mediates dorso-ventral patterning in embryo by Epithelio-Mesenchymal Transition(EMT) mechanisms. Recent studies suggest that neoplastic cells acquire a functional TLR-9 pathway during cancer progression.
Design: mRNA expression of 18 genes of the TLR-9 pathway (TLR-9, MyD88, TICAM1, TRAF3, TKB1, IRAK4, IKBKE, IRF3, IRF7, TRAF6, IRAK1, IRAK2, TAK1, IKKa, IKKb, NEMO, cREL, NFkB1), 8 genes implicated in EMT(TWIST1, ZEB1, FOXC2, HIF1A, GLUT1, CDH1, VIM, ACTA2/SMA)and IL1, IL6, IL8, IFN, TNF, STAT1, SOX1, SOX2, SOX9, CD133, was performed by real time quantitative RT-PCR in forty invasive carcinomas. TLR-9/CD289, IKBKE, ZEB1, FOXC2, E Cadherin, Vimentin, ACTA2/SMA, MMP13 and HIF1 protein expressions were sought by immunohistochemistry(ICH).
Results: Real time RT-PCR revealed high mRNA levels of (i) both TIR-containing adaptor TRIF/TICAM1 and MyD88 (ii) downstream signaling pathways complex components including the breast oncogene IKBKE and NFkB1(iii) IL1, IL6, IL8, IFN, HIF1A, GLUT1 and (iv) 7 EMT genes (TWIST1, FOXC2, CDH1, VIM, ACTA2, HIF1A, GLUT1). IHC showed that TLR-9 and IKBKE protein expressions were respectively increased in 23/40 (57%) and 21/40(52%) cases with a diffuse cytoplasmic staining(score 3/4+), particularly in the triple negative carcinomas (TNC). Among TNC, 5/13 (38%) cases presented an intermediate EMT phenotype (E Cadherin +/-, Vimentin+, ZEB1-/+, Twist1+, FOXC2+). High positive correlation was observed between (i) TLR-9 and IKBKE at mRNA and protein levels (p<0.05), (ii) TLR-9, NFkB1, HIF1A and GLUT1 coexpression (p<10-7), (iii)TLR-9, NFkB1, HIF1A and GLUT1 coexpression and acquisition of an EMT phenotype (P<10-6). (i) and (ii) were further obtained from a large series of 371 ductal breast carcinomas.
Conclusions: A functional and activated TLR-9 pathway was identified in invasive breast carcinomas, particularly in the TNC subgroup. Analysis of the downstream molecular actors suggests that neoplastic cells acquire immune, survival and EMT properties through activation of the IKBKE/NFkB1/HIF1A/GLUT1 pathway.
Wednesday, March 24, 2010 1:00 PM
Poster Session VI # 3, Wednesday Afternoon