Androgen receptor W741C and T877A mutations in AIDL cells, an androgen-independent subline of prostate cancer LNCaP cells

The androgen-independent LNCaP (AIDL) cell line was generated by maintaining prostate cancer LNCaP cells in a hormone-deprived medium. Notably, synthetic androgen R1881-related gene response is attenuated in AIDL cells as compared to the parental LNCaP cells. The aim of this study was to clarify the mechanisms underlying androgen sensitivity in AIDL cells. We first examined the expression of androgen receptor (AR) and its co-regulators. However, no significant difference in mRNA expression was found between LNCaP and AIDL cells. Remarkably, AR protein levels were induced by R1881 and DHT in LNCaP cells, but not in AIDL cells. We next performed the cDNA sequencing to detect mutations in the AR gene. The T877A mutation was detected both in LNCaP and AIDL cells. Furthermore, AIDL cells harbored a missense substitution (TGG → TGT) in the AR gene, which caused a point mutation at codon 741 (W741C). Double T877A and W741C AR mutants have been previously reported to exhibit reduced androgen sensitivity. Hence, the low-androgen-sensitive responses of AIDL cells may be explained, at least in part, by AR gene mutations.