Down-regulation of Hsp27 radiosensitizes human prostate cancer cells

AIM: In this study, we examined whether human Hsp27 is involved in the radiation sensitization induced by gamma radiation in cultured human prostate cancer cells. METHODS: We transfected DU145 cells with full length Hsp27 antisense cDNA to obtain viable cell lines which expressed reduced Hsp27. Selected individual clones were subjected to western blot analyses to confirm reduced expression of Hsp27. RESULTS: Hsp27 belongs to a family of abundant and ubiquitous stress proteins, the small heat shock proteins. It has been shown that Hsp27 can inhibit apoptosis both in a caspase-dependent and independent manner. Colony assays showed that the cells engineered to express reduced Hsp27 levels had a significantly increased sensitivity to gamma radiation compared with control cells that were transfected with the vector alone. However, there was also a significant difference in viability of cells with reduced Hsp27 levels and control cells 72 h after gamma-irradiation. CONCLUSIONS: Our results suggest the possible application of antisense Hsp27 cDNA or other methods to reduce Hsp27 expression as a radiation sensitizer in radiation oncology.     

Prognostic significance of microscopic bladder neck invasion in prostate cancer

OBJECTIVE

To assess the prognostic significance of microscopic bladder neck invasion (BNI+) after radical prostatectomy (RP).

PATIENTS AND METHODS

From January 1988 to December 2006, 1480 patients with clinically localized prostate cancer were surgically treated at one tertiary university hospital. The risk of biochemical progression, defined as a prostate‐specific antigen (PSA) level after RP of >0.2 ng/mL, was assessed with univariate and multivariate analyses for clinical and pathological variables. We compared the biochemical progression‐free survival (bPFS) of patients with BNI+ vs stages pT2, pT3a, pT3b and positive lymph nodes (N+). In a second analysis, we evaluated the bPFS of patients in different stages associated with BNI+ and compared them with those in the same stages with no BNI.

RESULTS

BNI+ was found in 132 (9%) patients; the 5‐year bPFS was 86%, 54%, 26% and 10% for stages pT2, pT3a, pT3b and N+, respectively, while it was 30% for BNI+ (P < 0.001). There was no difference in the 5‐year bPFS between stage pT2 and pT2 + BNI (P = 0.32). Stages pT3a and pT3b had a better 5‐year bPFS than stage pT3a + BNI (P = 0.003) and pT3b + BNI (P = 0.001), respectively. In the univariate analysis all variables were associated with BP. In the multivariate analysis, only BNI+ had no association with BP (odds ratio 1.14, 95% confidence interval 0.70–1.85; P = 0.59).

CONCLUSIONS

Microscopic BNI+ in prostate cancer is not an independent risk factor for biochemical progression and should be regarded as a factor that worsens the prognosis of the underlying tumour stage. A longer follow‐up is necessary to confirm these findings.     

Stable lower PAR expression decreased DU145 prostate cancer cell growth in SCID mice.

BACKGROUND: PAR is a novel gene ubiquitously expressed in normal and malignant tissues with a trend towards higher expression in tumor cells. PAR biological function is unknown. Here we report the effect of lowering PAR expression on in vitro and in vivo proliferation of DU145 cells. METHODS: Decreased PAR expression was achieved by stable transfection of DU145 cells with antisense PAR cDNA cloned in pCMV-Script expression vector. The proliferative potential of DU145 transfectants was studied by cell counts, colony formation in soft agar, flow cytometry, and growth in severe combined immunodeficient (SCID) mice. RESULTS: DU145 transfectants exhibited a decreased cell proliferation in tissue culture and a low efficiency of colony formation in soft agar. Flow cytometry revealed an arrest of these cells in G2-M phase of mitotic cycle. A dramatic decrease of tumor growth was observed when DU145 transfectant cells were inoculated in SCID mice, compared with controls. Histological examination of these tumors showed a marked decrease in cell density and in number of mitoses while control tumors showed a high cell density and numerous mitoses. CONCLUSIONS: The data presented here provide the first evidence for PAR gene cellular function and its possible implication in malignant transformation.     

iNOS基因转染对雄激素非依赖性前列腺癌细胞DU145生长的影响

目的:观察诱导型一氧化氮合酶(iNOS)基因转染对雄激素非依赖性前列腺癌细胞DU145生物学行为的影响。方法:将iNOS基因转染到DU145细胞并筛选出阳性细胞进行扩增,并设空载体组和对照组。观察细胞的形态变化,MTT法绘制生长曲线;流式细胞术检测细胞凋亡率;了解NOS抑制剂对转染细胞的影响。结果:转染iNOS后,DU145细胞分泌的NO[(272.50±15.82)μmol/L]显著高于空载体组[(122.00±18.93)μmol/L]和对照组[(121.00±6.98)μmol/L](P<0.05)。流式细胞术检测结果提示转染iNOS组细胞凋亡率[(42.78±2.01)%]明显高于空载体组[(30.65±1.46)%]和对照组[(28.96±1.50)%](P<0.05)。MTT测定结果提示转染组细胞生长较空载体组和对照组减慢(P<0.05),NOS抑制剂可以加快其生长,但无显著性差异(P>0.05)。结论:iNOS基因转染可以使DU145细胞分泌较高浓度的NO,诱导细胞凋亡,抑制细胞生长,为晚期雄激素非依赖性前列腺癌的基因治疗提供一个有效的靶点。     

组织激肽释放酶基因7在前列腺癌组织中的表达

目的 探讨组织激肽释放酶基因7(KLK7)在不同前列腺组织中的表达情况.方法运用逆转录聚合酶链反应法检测正常前列腺(5例)、良性前列腺增生(BPH)及BPH细胞株(BPH1,13例)、前列腺癌及前列腺癌细胞株(8例)的上皮细胞中KLK7mRNA表达水平;蛋白质印迹法检测不同前列腺组织上皮细胞中KLK7蛋白表达水平;免疫组化分析正常前列腺(20例)、BPH(50例)、前列腺癌(103例)组织中KLK表达水平.根据染色强度分为4个等级(-,+,++,+++)进行半定量分析,染色强度++及+++者判定为阳性.结果 正常组、BPH组和前列腺癌组KLK7 mRNA表达相对值分别为0.59、0.52、0.02,组间比较差异有统计学意义(F=13.03,P＜0.01),前列腺癌上皮中KLK7 mRNA表达下调(P＜0.01),正常前列腺和BPH上皮中KLK7 mRNA表达差异无统计学意义(P＞0.05).KLK7蛋白在正常前列腺、增生前列腺、DU145、LNCaP、PC3、22RV1、BPH细胞株中表达水平相对值分别为0.22、0.40、0.01、0.05、0、0.03、0.14.免疫组化染色结果 显示正常前列腺组织、BPH组织、前列腺癌中KLK7蛋白表达阳性率分别为65.0%(13/20)、76.0%(38/50)、17.5%(18/103),前列腺癌组与前2组比较差异均有统计学意义(P＜0.01),前2组间比较差异无统计学意义(P＞0.05).结论 KLK7在前列腺癌组织中表达下调,提示KLK7在前列癌的发生和进展中可能起一定作用.     

Impact of uni- or multifocal perineural invasion in prostate cancer at radical prostatectomy

BackgroundAim of this study was to correlate perineural invasion (PNI) with other clinical-pathological parameters in terms of prognostic indicators in prostate cancer (PC) cases at the time of radical prostatectomy (RP).MethodsProspective study of 288 consecutive PC cases undergoing RP. PNI determination was performed either in biopsy or in RP specimens classifying as uni- and multifocal PNI. The median follow-up time was 22 (range, 6–36) months.ResultsAt biopsy PNI was found in 34 (11.8%) cases and in 202 (70.1%) cases at the time of surgery. Among those identified at RP 133 (46.1%) and 69 (23.9%) cases had uni- and multi-PNI, respectively. Presence of PNI was significantly (P<0.05) correlated with unfavorable pathological parameters such higher stage and grade. The percentage of extracapsular extension in PNI negative RP specimens was 18.6% vs. 60.4% of PNI positive specimens. However, the distribution of pathological staging and International Society of Urological Pathology (ISUP) grading did not vary according to whether PNI was uni- or multifocal. The risk of biochemical progression increased 2.3 times in PNI positive cases was significantly associated with the risk of biochemical progression (r=0.136; P=0.04). However, at multivariate analysis PNI was not significantly associated with biochemical progression [hazard ratio (HR): 1.87, 95% confidence interval (CI): 0.68–3.12; P=0.089]. Within patients with intermediate risk disease, multifocal PNI was able to predict cases with lower mean time to biochemical and progression free survival (chi-square 5.95; P=0.04).ConclusionsPNI at biopsy is not a good predictor of the PNI incidence at the time of RP. PNI detection in surgical specimens may help stratify intermediate risk cases for the risk of biochemical progression.     

Perineural invasion in prostate cancer biopsies is not associated with higher rates of positive surgical margins

PURPOSE: High rates of extracapsular tumor extension have been reported with biopsy perineural invasion (PNI), leading some to advocate routine resection of the ipsilateral neurovascular bundle (NVB) with radical retropubic prostatectomy (RRP) to assure negative surgical margins. The contemporary rates of extracapsular tumor extension (ECE) and margin status associated with biopsy PNI were investigated. MATERIALS AND METHODS: The prostate needle biopsies, RRP specimens, and operative reports of 452 consecutive patients undergoing RRP by a single surgeon were reviewed to determine the presence of PNI invasion, presence of ECE, margin status, and preservation of NVB. Patients were excluded from the analysis if they underwent preoperative hormonal ablation or if their original biopsy was not reviewed by the pathologists at our institution. Both univariate and multivariate analyses were performed to determine the effect of PNI on extracapsular extension, the likelihood of performing a bilateral nerve-sparing technique, and the result of a positive surgical margin. RESULTS: In the 402 evaluable cases, based on multivariate models PNI showed only a marginal association with positive surgical margin (+SM) (P = 0.10) and bilateral nerve-sparing (B-NS) (P = 0.07), but was significantly associated with organ confinement (P = 0.03). The odds ratio (OR) of PNI for +SM, although not statistically significant, was 0.36. Although showing a higher level of statistical significance, PNI for OC had an odds ratio of 0.50. Similarly, the odds ratio was 0.54 for B-NS. CONCLUSIONS: Although biopsy PNI alone was associated with a higher probability of ECE, it is not predictive of bilateral nerve-sparing technique or a positive surgical margin in an individual patient.     

Prognostic significance of capsular invasion and capsular penetration in patients with clinically localized prostate cancer undergoing radical prostatectomy

One hundred thirty patients with an observed follow-up of more than 10 years after radical prostatectomy were restaged with regard to local extent of the tumor in relation to the prostate capsule. Of 112 patients with surgically staged negative pelvic lymph nodes, 62 had a tumor-free prostate capsule, 24 had capsular invasion without penetration, and 26 had tumors extending through the capsule of the prostate. Observed overall and disease-free 10-year-survival rates were 79% and 69.4%, respectively, in patients with absence of capsular involvement and 70.8% and 66.7%, respectively, in patients with capsular invasion alone. In patients with capsular penetration, however, the survival rates significantly decreased to 57.7% (P = 0.018) and to 38.5 (P = 0.017), respectively. The overall progression rate was found to be significantly higher in patients with tumors extending through the prostatic capsule (46.2%), as compared to those with absence of capsular involvement (21%; P = 0.014) as well as to those with capsular invasion alone without penetration (25%; P = 0.034). Thus, in contrast to capsular invasion alone, capsular penetration means a poor prognostic indicator, which accounts for a reduced survival expectancy and a higher progression rate following radical prostatectomy. Therefore, tumors with capsular invasion and those with capsular penetration should not be grouped together in the same tumor stage as done in the 1987 edition of the TNM tumor clasification system. © 1995 Wiley-Liss, Inc.     

茶多酚对前列腺癌细胞DU145生长的影响

目的:探讨茶多酚对前列腺癌细胞生长的影响及其作用机制。方法:选取激素非依赖性前列腺癌细胞系DU145为研究对象,在药物组的培养基中加入茶多酚使其终浓度分别为50、100、250、500μg/ml,对照组加入正常细胞培养基。各组细胞培养48 h后,采用MTT比色法检测细胞生存率,然后通过Western印迹分析和荧光定量RT-PCR法检测各组细胞survivin基因表达情况。结果:加入茶多酚溶液48 h后,各药物组细胞存活率分别为0.97±0.12、0.71±0.07、0.20±0.03和0.08±0.01,与对照组相比,除50μg/ml组(P=0.42)外,其余3个药物组细胞存活率均明显低于对照组(P﹤0.01)。随茶多酚作用时间增加,各组细胞存活率呈现下降趋势,到96 h时,除50μg/ml组,其余3组细胞存活率均在5%以下。加药48 h后,对照组、100、250、500μg/ml药物组的sur-vivin表达条带灰度值分别为15 075±48、13 425±31、2 017±24、1 274±22,与对照组相比,3个药物组survivin蛋白表达均明显减少(P均﹤0.01)。另外,50、100、250、500μg/ml药物组给药48 h时的survivin mRNA量分别为0.74±0.03、0.64±0.02、0.52±0.01、0.21±0.02,均明显少于对照组(P均﹤0.01)。结论:茶多酚可以抑制前列腺癌DU145细胞的生长,且这种作用可能与survivin基因表达减少有关。     

Perioperative complications of radical retropubic prostatectomy in patients with locally advanced prostate cancer: a comparison with clinically localized prostate cancer

Radical prostatectomy (RP) continues to be an effective surgical therapy for prostate carcinoma, particularly for organ-confined prostate cancer (PCa). Recently, RP has also been used in the treatment of locally advanced prostate cancer. However, little research has been performed to elucidate the perioperative complications associated with RP in patients with clinically localized or locally advanced PCa. We sought to analyse the incidence of complications in these two groups after radical retropubic prostatectomy (RRP). From June 2002 to July 2010, we reviewed 379 PCa patients who underwent RRP in our hospital. Among these cases, 196 had clinically localized PCa (T_1a–T_2c: group 1), and 183 had locally advanced PCa (≥T_3a: group 2). The overall complication incidence was 21.9%, which was lower than other studies have reported. Perioperative complications in patients with locally advanced PCa mirror those in patients with clinically localized PCa (26.2% vs. 17.8%, P=0.91). Our results showed that perioperative complications could not be regarded as a factor to consider in regarding RP in patients with cT₃ or greater.     

Tumor suppressor gene P53 mutations in human prostate cancer

The genetic background underlying the growth and development of human prostatic cancer is not yet clear. Here we searched for possible mutations in the entire coding region of tumor suppressor gene p53 in primary human prostatic carcinomas, using polymerase chain reaction and single-strand conformational polymorphism analysis of RNA. We found p53 gene mutations in 4 of 21 cases (19%). DNA sequencing of the polymerase chain reaction products revealed missense point mutations that resulted in amino acid changes in exon 5 or 3 in three cases and single base deletions in exon 7 in two cases. One case contained both a missense point mutation and a single base deletion. Three of these four cases were pathologically diagnosed as poorly differentiated adenocarcinomas, and three of the four cases were clinically localized to stage C or D. None of seven noncancerous prostate tissues nor three well-differentiated adenocarcinoma tissues showed any mutations. The present results suggest that p53 gene mutation is involved in the late progression steps of human prostate carcinogenesis. © 1995 Wiley-Liss, Inc.     

Microvascular invasion of the seminal vesicles in adenocarcinoma of the prostate

The objective of this article is to determine the relationship between microvascular invasion and seminal vesicle invasion in prostatic adenocarcinoma. Radical prostatectomies with seminal vesicle involvement were examined histologically and immunohistochemically with antibodies directed against S-100 protein and factor VIII. Microvascular invasion of the seminal vesicles showed a positive correlation with microvascular and capsular invasion of the prostate (P = 0.006 and 0.048, respectively) and lymph node metastases. Tumor progression was found in 8 of 14 (57%) patients with microvascular invasion of the seminal vesicles, compared with 3 of 22 (14%) without microvascular invasion (P = 0.001). Microvascular invasion of the seminal vesicles is predictive of tumor progression and lymph node metastases in prostatic adenocarcinoma. © 1996 Wiley-Liss, Inc.