At IC50 for HAase activity inhibition (5-20 μg/ml [0.4-1.7 μM]), sHA-F significantly inhibited proliferation, motility and invasion of HYAL-1 expressing BCa cells (253J-Lung, HT1376, UMUC-3), P<0.001. sHA-F did not affect the growth of HYAL-1 non-expressing BCa (5637, RT4, T24, TCCSUP) and normal urothelial (Urotsa, SV-HUC1) cells. sHA-F treatment induced apoptosis by death receptor pathway. sHA-F downregulated transcript and/or protein levels of HA receptors (CD44, RHAMM), p-AKT, β-catenin, pβ-Catenin(S552), Snail and Twist but increased levels of pβ-Catenin(T41/S45), pGSK-3α/β(S21/S9) and E-cadherin. sHA-F also inhibited CD44/Phosphoinositide 3-kinase (PI-3K) complex formation and PI-3K activity.
Among the HA family members, transcript levels of the HA synthases, HYAL-1, CD44v, and RHAMM were 4- to 16-fold higher in BCa tissues than in normal tissues (P < .0001); however, CD44s levels were lower.