In this work the impact of substrate elasticity on the proliferation of two cell lines, a non-malignant transitional epithelium HCV-29 and a bladder transitional cell carcinoma T24 cultured individually and in co-culture was analyzed. A significantly stronger, highly cell-dependent impact of mechanical properties on cellular behavior was shown for cells co-cultured from the mixture. A more effective proliferation process observed for T24 cells was analyzed quantitatively for asymmetric HCV29: T24 mixtures co-cultured on soft substrate. The obtained results suggest that the proliferation of T24 cells is even 4 times more effective as compared to HCV29 cells and confirm strong invasiveness of metastatic T24 cells. The high adaptiveness of T24 cells to adverse environmental conditions enables easy and accurate discrimination between not isolated healthy and cancer cells.