Expression of TLR4 in normal human and SCC skin.

<p>The expression level of TLR4 was analyzed on formalin-fixed paraffin-embedded skin samples and tissue microarray samples by immunochistochemistry using specific anti human TLR4 antibody (HTA125, dilution 1:100). The expression was tested in 225 SCC patient samples (moderately or well differentiated) and in 23 samples from normal skin. (A) Positive staining for TLR4 in normal epidermis. (B) Positive staining for TLR4 in moderately differentiated SCC. (C) Positive staining for TLR4 in well differentiated SCC. TLR4 positive keratinocytes show red intensity staining. TLR4 expression is visible in the membrane regions and perinuclear (cytoplasmic) regions and pointed by arrows. (D) Positive staining for TLR4 found in normal skin and maintained in SCC. (E) Positive staining for TLR4 is found in SCC in different stages of differentiation (moderately and well differentiated SCC). (F) Positive correlation between TLR4 and IRF6 expression (staining intensity) in moderately versus well differentiated SCC epidermis. The intensity of staining was analyzed by arbitrary evaluation and presented as arbitrary units respectively as weak, middle and strong staining. The expression level (intensity) of TLR4, IRF6 and the IRF6/TLR4 correlation were evaluated using t-test and Anova. P-values below 0.0001 and 0.05 (p<0.05; p<0.0001) were considered as significant.