OBJECTIVETo investigate the expression of the Pim-1 gene in the LNCaP cells of the animal model of orthotopically implanted prostate cancer by surgical castration simulating androgen-deprivation therapy.

METHODSWe equally allocated 32 male BALBc-nu mice into 4 groups, androgen-dependent prostate cancer (ADPC), androgen-deprivation therapy (ADT) , castration-resistant prostate cancer (CRPC) and blank control, and established the models of orthotopically implanted tumor using human prostate cancer LNCaP cells. We detected and ,compared the expressions of Pim-1, PSA, and androgen receptor (AR) in the tumor tissues of different groups by RT-PCR. qRT-PCR, ELSIA and immunohistochemistry.

RESULTSThe relative gray scales in the ADPC and CRPC groups were 0.59 ± 0.01 and 1.14 ± 0.02, with statistically significant differences from 0.62 ± 0.03 in the ADT group (P < 0.05), and the Δ Ct values of Pim-1 were 6.15 ± 0.34 and 4.56 ± 0.23 in the former two groups, also with significant differences from 5.11 ± 0.21 in the latter (P < 0.05). The results of 2-ΔΔ Ct relative quantification analysis showed that the amplification products of Pim-1 in the ADT and CRPC groups increased 2.05 and 3.01 times respectively that of the ADPC group. The concentration of PSA was significantly higher in the ADPC ([480 ± 25] pg/ml) and CRPC ([870 ± 23] pg/ml) than in the ADT ([170 ± 32] pg/ml) and blank control groups (0 µg/L) (P < 0.01). The mean optical densities of Pim-1 and AR proteins were 0.017 ± 0.002 and 0.032 ± 0.009 in the ADPC group and 0.024 ± 0.002 and 0.040 ± 0.011 in the CRPC group, both with significant differences from those in the ADT group (0.018 ± 0.001 and 0.019 ± 0.006) (P < 0.01).

CONCLUSIONPim-1 is highly expressed in nude mice with prostate cancer receiving androgen-deprivation therapy and plays an important role in the progression and metastasis of prostate cancer.