Expression antimikrobieller Peptide in Bronchialkarzinomen

Antimicroial peptides (AMPs) are effector molecules of the innate host defense system. They are produced by epithelial and host defense cells. AMPs inactivate microbes and, in addition, impact on cellular processes such as angiogenesis, inflammation, or cell growth. These findings implicate a role of AMPs in cancer biology. Defensins and cathelicidins are families of AMPs that are expressed in the human lung and thus potentially also in epithelial lung cancers. It has been the aim of this study to examine whether AMPs are expressed in lung cancer. Paraffin-embedded samples of human lung cancer were immunostained for LL-37, hBD-1, hBD-2, FPRL-1, HLA, Ki-67 and vWF using polyclonal antibodies. The results are analysed quantitative and qualitative. This study showes, that AMPs are expressed in NSCLC. HBD-1 was detected in 91%, hBD-2 in 38% and LL-37 in 55%. In SCLC there are not any expression. If LL-37, hBD-1 and hBD-2 were positive, there were more dendritic cell and cells with Ki-67. This study shows a significant correlation between the expression of LL-37 and FPRL-1 in lung carcinomas. If LL-37 was positive, there were more vessels, whereas hBD-1 showed no and hBD-2 a reversed result. LL-37/hCAP-18 could favour the tumour vasculogenese, also there was no significance. The vascularisation could be by a direct effect from FPRL-1 at the endothelial cells. LL-37 could support the tumour growth in two ways: It could activate tumour cells direct or indirect through vessel proliferation. In summary, AMPs of the defensin and cathelicidin family are expressed in human lung cancer. They potentially are involved in tumor generation and growth.