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To investigate the effect of the down-regulated expression of pituitary tumor-transforming gene 1 (PTTG1) on the senescence of human castration-resistant prostate cancer LNCaP-AI cells.Human castration-resistant prostate cancer LNCaP-AI cells were induced in vitro and transfected with siRNA targeting PTTG1 (the siRNA-PTTG1 group), the reagent lip3000 only (the mock group) or siRNA negative control vector (the NC group). All the cells were cultured in fetal bovine serum (FBS) or charcoal-stripped bovine serum (CSS) and counted with the cell counting chamber. The senescence characteristics of the transfected LNCaP-AI cells were examined by senescence-associated β-galactosidase (SA-β-Gal) staining, and the expressions of the senescence-related β-galactosidase-1-like proteins (Glb1), the cyclin-dependent kinase inhibitors p-21CIP1 and p-27Kip1, and the chromatin-regulating heterochromatin protein 1γ (HP1γ) were detected by Western blot.The expression of PTTG1 in the human prostate cancer LNCaP-AI cells was significantly reduced in the siRNA-PTTG1 group compared with those in the mock and NC groups (0.21 ± 0.01 vs 0.56 ± 0.02 and 0.61 ± 0.02, P0.05). Culture with FBS markedly increased while that with CSS decreased the number of LNCaP-AI cells transfected with siRNA, but both FBS and CSS enhanced the proliferation of the LNCaP-AI cells in the mock and NC groups. SA-β-Gal staining revealed that reducing the expression of PTTG1 induced a remarkably higher positive rate of the LNCaP-AI cells in the siRNA-PTTG1 than in the mock and NC groups (［63.5 ± 2.35］% vs ［11.3 ± 1.24］% and ［12.4 ± 1.15］%, P0.05). The siRNA-PTTG1 group, in comparison with the mock and NC groups, showed a significantly down-regulated expression of PTTG1 (0.21 ± 0.01 vs 0.56 ± 0.02 and 0.61 ± 0.02, P0.05), but up-regulated expressions of p-21CIP1 (0.32 ± 0.03 vs 0.20 ± 0.02 and 0.21 ± 0.03, P0.05), p-27Kip1 (0.38 ± 0.02 vs 0.20 ± 0.03 and 0.22 ± 0.01, P0.05), Glb1 (0.24 ± 0.01 vs 0.13 ± 0.01 and 0.15 ± 0.01, P0.05), and HP1γ (0.41 ± 0.01 vs 0.26 ± 0.01 and 0.27 ± 0.02, P0.05) in the LNCaP-AI cells.Down-regulated expression of PTTG1 induces senescence of human castration-resistant prostate cancer LNCaP-AI cells.

To investigate the effects of down-regulation of PTTG1 expression on the proliferation, invasiveness and apoptosis of androgen-independent human prostate cancer LNCaP-AI cells and their sensitivity to androgen antagonists.Human prostate cancer LNCaP-AI cells were transfected with siRNA targeting the PTTG1 gene using the Lipofectamine 2000 transfection reagent. The proliferation, invasiveness and apoptosis of the cells were detected by MTT, Transwell assay and flow cytometry, respectively. The protein expressions of PTTG1, p-Akt, and p-ERK were determined by Western blot and the mRNA expression of PTTG1 measured by agarose gel electrophoresis.The siRNA expression vector markedly down-regulated the expression of PTTG1, which effectively suppressed the proliferation of the LNCaP-AI cells, with the inhibition rates of (19.47 ± 2.12), (24.01 ± 2.13) and (48.02 ± 2.22)% at 24, 48 and 72 hours, respectively, after transfection, with statistically significant differences among the three groups (P0.05). The number of the cells passing through the polycarbonate film was remarkably decreased at 24, 48 and 72 hours (74.67 ± 9.85, 56.44 ± 8.66 and 37.33 ± 6.14) as compared with the baseline (111.11 ± 13.47) (P0.01), while the apoptosis rate of the cells was significantly increased at 24, 48 and 72 hours (18.32 ± 0.94), (19.94 ± 1.30) and (21.73 ± 1.88)% in comparison with the baseline (［2.17 ± 0.49］%)， (P0.05). PTTG1 siRNA combined with androgen antagonist flumatide exhibited even more significant effects in inhibiting the proliferation and promoting the apoptosis of the LNCaP-AI cells than either used alone, and in a flumatide dose-dependent manner. The inhibition and apoptosis rates of the LNCaP-AI cells treated with 50 nmol/L flumatide were (27.13 ± 3.52) and (3.94 ± 0.48)%, and those treated with siRNA + 50 nmol/L flumatide were (67.51 ± 5.13) and (19.93 ± 1.72)%, respectively, both with statistically significant differences between the two groups (P0.05). The inhibition and apoptosis rates of the cells treated with 100 nmol/L flumatide were (43.72 ± 3.90) and (5.33 ± 0.66)%, and those treated with siRNA + 100 nmol/L flumatide were (73.19 ± 4.78) and (23.43 ± 1.76)%, respectively, both with statistically significant differences between the two groups (P0.05).The siRNA expression vector can down-regulate the expression of PTTG1, which can inhibit the proliferation and invasiveness of LNCaP-AI cells, promote their apoptosis, and increase their sensibility to androgen antagonists. Suppressing the expression of PTTG1 may enhance the effect of androgen-deprivation therapy on advanced prostate cancer.目的： 探讨下调垂体肿瘤转化基因1（PTTG1）表达对雄激素非依赖性前列腺癌LNCaP-AI细胞增殖、侵袭、凋亡，以及对雄激素拮抗剂敏感性的影响。方法： LNCaP-AI细胞转染靶向PTTG1基因的siRNA，MTT法检测细胞增殖，Transwell法检测细胞侵袭，流式细胞术检测细胞凋亡，Western印迹检测PTTG1、p-Akt、p-ERK等蛋白表达水平，琼脂糖凝胶电泳法检测PTTG1 mRNA表达水平。结果： siRNA有效抑制了PTTG1的表达；下调PTTG1表达有效抑制了LNCaP-AI细胞在去雄激素培养液中的增殖，24、48、72 h抑制率分别为（19.47±2.12）%、 （24.01±2.13）% 、(48.02±2.22) %，组间比较有显著性差异（P0.05）；降低其侵袭力，Transwell试验显示，对照组、转染24、48、72 h后穿过聚碳酸酯膜细胞个数分别为111.11±13.47、74.67±9.85、56.44±8.66、37.33±6.14，组间比较有显著性差异（P0.01）；siRNA-PTTG1转染LNCaP-AI细胞后，空白对照组、转染24、48、72 h后凋亡率分别为(2.17±0.49)%、(18.32±0.94)%、(19.94±1.30)%、(21.73±1.88)%，各组间比较有显著性差异（P0.05）。siRNA联合氟他胺组对LNCaP-AI增殖的抑制作用和促凋亡作用显著强于siRNA或者氟他胺组，并呈氟他胺浓度相关性；50 nmol/L氟他胺、siRNA联合50 nmol/L氟他胺对LNCaP-AI的抑制率分别为（27.13±3.52）%、（67.51±5.13）%，两组间比较有显著性差异（P0.05）；凋亡率分别为（3.94±0.48）%、（19.93±1.72）%，两组间比较有显著性差异（P0.05）；100 nmol/L氟他胺、siRNA联合100 nmol/L氟他胺的抑制率分别为（43.72±3.90）%、（73.19±4.78）%，两组间比较有显著性差异（P0.05）；凋亡率分别为（5.33±0.66）%、（23.43±1.76）%，两组间比较有显著性差异（P0.05）。结论： siRNA下调PTTG1表达能够抑制LNCaP-AI的增殖和侵袭，促进凋亡，提高了LNCaP-AI细胞对雄激素拮抗剂氟他胺的敏感性，抑制PTTG1表达可能会强化雄激素剥夺治疗晚期前列腺癌的作用。.

To explore the expression of pituitary tumor transforming gene 1 (PTTG1) during the transformation of prostate cancer from androgen-dependent (ADPC) to androgen-independent (AIPC).We established an AIPC cell model LNCaP-AI by culturing the androgen-dependent LNCaP cell line in the hormone-deprived medium for over 3 months. The cell model was verified and the PTTG1 expression in the LNCaP cells was detected by Western blot and RT-PCR during hormone deprivation.The AIPC cell model LNCaP-AI was successfully established. The PTTG1 expression was gradually increased in the LNCaP cells with the prolonged time of hormone deprivation and the expressions of matrix metalloproteinases MMP-2 and -9 were elevated at the same time.The expression of PTTG1 is increased gradually in AIPC, which may be a target of gene therapy for advanced prostate cancer.目的： 探讨垂体肿瘤转化基因1(PTTG1)在前列腺癌由激素依赖性转化为激素非依赖性过程中的表达变化。方法： 通过在去雄激素培养条件下长期培养雄激素依赖性前列腺癌细胞株LNCaP，建立并验证雄激素非依赖性亚系LNCaP-AI细胞模型，用Western印迹、RT-PCR方法每2周检测在去雄激素培养过程中PTTG1的表达改变。结果： 经过3个月培养，成功建立雄激素非依赖性亚系LNCaP-AI细胞模型；在LNCaP细胞中，随着去雄激素培养时间延长，PTTG1的表达水平逐渐升高，基质金属蛋白酶-2(MMP-2)和MMP-9表达有同步升高趋势。结论： PTTG1表达在雄激素非依赖性前列腺癌发生过程中逐渐增强，可能是晚期前列腺癌基因治疗的靶标之一。.

We investigated the prognostic value of pituitary tumor transforming gene 1 (PTTG1) expression according to clinicopathological features among localized or locally advanced prostate cancer cases receiving hormone therapy. A retrospective study involved 64 patients receiving combined androgen blockade treatment was performed. PTTG1 expression was determined by immunohistochemical staining using initial needle biopsy specimens for diagnosis. Associations of PTTG1 with various clinicopathological features and disease-free survival were examined via uni- and multivariate analyses. No association between PTTG1 expression and clinical T stage, Gleason score, pretreatment PSA levels, risk groups was found (p =0.682, 0.184, 0.487, 0.571, respectively). Univariate analysis revealed that increased PTTG1 expression, T3 stage and high risk group were associated with increased risk of disease progression (p =0.000, 0.042, and 0.001), and high PSA level had a tendency to predict disease progression (p =0.056). Cox hazard ratio analysis showed that PTTG1 low expression (p =0.002), PTTG1 high expression (p =0.000) and high risk group (p =0.0147) were significantly related to decreased diseasefree survival. In conclusion, PTTG1 expression determined by immunohistochemical staining in needle biopsy specimens for diagnosis is a negative prognostic factor for progression in localized or locally advanced prostate cancer receiving hormone therapy.

To evaluate the detection of prostate cancer in different prostate specific antigen (PSA) level and the predict value of PSA, digital rectal examination (DRE), transrectal ultrasound scan (TRUS) and PSA density (PSAD).The clinical data of 634 cases who had underwent transrectal ultrasound guided systematic sextant prostate biopsies between April 1996 to December 2002 due to being suspicious of prostate cancer were retrospectively analyzed. The detection of prostate cancer in different PSA groups, namely PSAor = 4.0, 4.1-, 10.1-,20.0 microg/L, and the predict values of PSA, DRE, TRUS and PSAD were statistically analyzed using t test, chi2 test and logistic regression analysis.The rates of prostate cancer detection in different PSA groups were 11.6%, 26.8%, 39.8% and 68.6%, respectively. The higher the PSA, the higher the rate of prostate cancer detection, the same was the positive predictive value of DRE and TRUS. The sensitivity and specificity of PSA4.0 microg/L were 93.0% and 33.0%, and the efficiency of DRE and TRUS were very low. Logistic regression analysis indicated that PSAD was the most risk factor of prostate cancer in the group of PSA 4.1-20.0 microg/L (OR = 687.09 +/- 646.96, P = 0.000).The rates of prostate cancer detection in different PSA groups are different compared with other countries. The screening roles of DRE and TRUS are dependent on PSA level. Utilization of the screening protocol which to stratify cases into three PSA groups, namely PSAor = 4.0, 4.1 - 20.0,20.0 microg/L, can elevate the positive rate of prostate biopsies without sacrificing cancers detected.

To investigate the usefulness of percentage of free prostate specific antigen (FPSA/TPSA) in serum/PSA density [(F/T)/PSAD] in the diagnosis of prostate cancer.Two hundred and four patients who had been carried out transrectal ultrasound guided prostate biopsy, were involved in this study. Among them, 90 patients were proved to be suffering from prostate cancer, and other 114 patients were identified as benign prostate hypertrophy. The effect of total serum PSA level, FPSA/TPSA, PSAD and (F/T)/PSAD in the diagnosis of prostate cancer were investigated, and at the same time, selecting patients who should be carried out a prostate biopsy.The mean values of (F/T)/PSAD were significantly lower for patients with prostate cancer in different PSA levels (4.0, 4.0-, 10.1-,20.0 microg/L), when compared with benign prostate hypertrophy patients. This difference has arrived statistical significance (P0.05). (F/T)/PSAD could provide higher specificity for diagnosing prostate cancer than FPSA/TPSA or PSAD. Among all patients, at the same higher sensitivity (about 90%), the specificity of FPSA/TPSA, PSAD and (F/T)/PSAD was 31.6%, 45.6% and 64.0%, respectively. At the same time, it was suggested that clinicians use different cutoffs for (F/T)/PSAD in different PSA level. When PSA level of patients was no more than 4.0 microg/L, 2.5 as the commended cutoff for (F/T)/PSAD was preferred; if PSA level was between 4.0 microg/L and 20.0 microg/L, 0.8 was a more suitable cutoff; 0.5 also could be taken as an appropriate cutoff in case of PSA level being higher than 20.0 microg/L.Keeping high sensitivity, using of (F/T)/PSAD can improve the diagnostic specificity of prostate cancer significantly.