Specific protein and miRNA patterns characterise tumour-associated fibroblasts in bladder cancer

Tumour development and progression are strongly affected by interaction of tumour cells and tumour stroma. Different tumour models demonstrate a supportive effect of tumour-associated fibroblasts (TAF) on the tumour genesis. Aims of the present study are the isolation of TAF from primary urinary bladder tumour specimens and the proteomic and epigenetic characterisation. TAF were isolated from cultured urinary bladder tumour specimens. Therefore, primary tumour material was treated with EDTA followed by two separated detachment steps. Non-tumour fibroblasts were isolated from foreskin and normal bladder tissues. Proteins and total RNA were isolated from cultured fibroblasts. Protein pattern analyses were carried out by SELDI-TOF-MS. The miRNA expression profile was analysed by miRNA microarray. By optimising cell culture routines, we achieved to isolate and subsequently cultivate TAF from primary tumour material of the urinary bladder. SELDI-TOF-MS measurements reveal distinct differences in the proteomic patterns of TAF and non-tumour fibroblasts. Microarray analyses indicate specific expression of several miRNAs in TAF and non-tumour fibroblasts. In summary, we determined proteomic and epigenetic differences between non-tumour fibroblasts and TAF of urinary bladder carcinoma and identified specific protein expression patterns as well as miRNA profiles of TAF in comparison with non-tumour fibroblasts. These findings provide more insights into the complex tumour network and a good starting point for the identification of markers for the prediction of tumour development and progression based on specific TAF expression patterns.