Figure 3.

CRYM is inversely correlated with cytoplasmatic free T3 levels. The cytoplasmatic thyroid hormone binding protein μ-Crystallin (CRYM) binds T3 with high affinity. (Left) In normal tissues, the overexpression of T3-buffering CRYM leads to attenuating the growth-promoting effect of T3 by blocking its binding to thyroid hormone nuclear receptors (THR). (Right) In prostate cancer (PCa), the reduction of CRYM levels causes an enhanced cytoplasmatic availability of T3 resulting in an increase in the growth-promoting effect of T3 mediated by the binding to THR. CRYM, thyroid hormone binding protein μ-Crystallin; T3, tri-iodothyronine; THR, thyroid hormone receptor.