Polymorphisms in prostate stem cell antigen gene rs2294008 increase gastric cancer risk in Chinese

A recent genome‐wide study identified a strong association between polymorphisms in the prostate stem cell antigen (PSCA) gene and the risk of diffuse‐type of gastric cancer in Japanese and Korean population. In this case–control study, we aimed to investigate the possible association between PSCA rs2294008 C/T with clinicopathological features and the prognosis of gastric cancer in a Southern Chinese population. Genotypes of 460 gastric cancer patients and 549 controls were determined by PCR‐restriction fragment length polymorphism (PCR‐RFLP) and DNA sequencing. We found that individuals with at least one copy of the rs2294008T allele (CT or TT genotype) had an increased risk for gastric cancer compared with CC genotype (OR = 1.42, 95% CI = 1.10–1.82, P = 0.006). Further stratification analyses indicated that the effect of PSCA rs2294008T carriers was noteworthy in intestinal type (OR = 1.55, 95% CI = 1.18–2.04, P = 0.002), poorly differentiated (OR = 1.59, 95% CI = 1.19–2.13, P = 0.002), noncardia (OR = 1.55, 95% CI = 1.17–2.04, P = 0.002) subtypes of gastric cancer. Cox proportional hazards analyses demonstrated that TT genotype (HR = 2.12, 95% CI = 1.22–3.69, P = 0.008) as well as TNM staging were prognostic factors of gastric cancer patients. In conclusion, The T allele of PSCA rs2294008 is associated with increased risk of gastric cancer, especially intestinal type, poorly differentiated, early onset, and noncardia gastric cancer in Chinese population. TNM staging and TT genotype might be involved in the prognosis of gastric cancer patients. Mol. Carcinog. © 2011 Wiley‐Liss, Inc.     

前列腺干细胞抗原在前列腺癌诊断与治疗中的应用

人们对前列腺癌理想的诊断和治疗方式的探寻从未停止.近些年来,随着对前列腺干细胞抗原(prostate stem cell antigen,PSCA)研究地不断深入,特别是应用于前列腺癌诊治方面的新成果不断推出,使人们对PSCA充满期望.本文重点对PSCA的生物学特性及其在前列腺癌诊断方法和免疫治疗方面的新进展进行综述.     

Association of prostate stem cell antigen gene polymorphisms with the risk of stomach cancer in Japanese

A recent whole‐genome association study identified a strong association between polymorphisms in the prostate stem cell antigen (PSCA) gene and stomach cancer risk. In this case‐control study, we aimed to validate this association, and further to explore environmental factors possibly interacting with PSCA polymorphisms in 708 incident stomach cancer cases and 708 age–sex matched controls. The association between PSCA polymorphisms and Helicobacter pylori infection was also examined. We found that rs2294008 and rs2976392, which were strongly linked to each other (D′ = 1.00), were significantly associated with stomach cancer risk. Per allele odds ratio for rs2994008 was 1.40 (95% confidence interval: 1.19–1.65; p = 3.7 × 10^?5). We found significant interaction with a family history of stomach cancer in first‐degree relatives (p‐heterogeneity = 0.009). Similar to originally reported association, we found significant heterogeneity between diffuse and intestinal type (p‐heterogeneity = 0.007). No association was seen between PSCA polymorphisms and H. pylori infection. In conclusion, PSCA polymorphisms are associated with stomach cancer risk in Japanese. A possible interaction with family history warrants further evaluation. © 2009 UICC     

Flutamide reduced prostate cancer development and prostate stem cell antigen mRNA expression in high grade prostatic intraepithelial neoplasia

High-grade prostatic intraepithelial neoplasia (HGPIN) appears to represent an ideal target for chemoprevention of prostate cancer (PCa). HGPIN responds to androgen ablation and has prostate stem cell antigen (PSCA) mRNA expression. One hundred and seventy two patients with isolated HGPIN were randomized in a double-blind manner to receive flutamide 250 mg/day (86 cases) or a placebo (86 cases) for 12 months and were rebiopsied at 12 and 60 months. PSCA mRNA expression was assessed in the prestudy and 12-month biopsies by in situ hybridization. The incidence of subsequent PCa was 11.6% in the flutamide group when compared with 30.2% in the placebo group over a follow-up period of 5 years (p = 0.0027). PSCA mRNA expression levels were significantly declined after treatment compared with that before treatment (p < 0.001). After treatment, 66 patients had reduced PSCA mRNA expression, in whom none was found with cancer on follow-up, however, 13 cases had increased PSCA mRNA expression levels, in whom 11 were found with cancer. Cox regression analysis demonstrated that HGPIN with increased PSCA mRNA expression after flutamide had an increased relative risk of 4.33 to develop subsequent cancer (95% confidence intervals: 2.48-7.36; p < 0.001). Seventeen (19.8%) cases had the flutamide-associated side effects, which were graded as mild, but all did not discontinue study. Flutamide can effectively and safely reduce PCa development and significantly suppress PSCA mRNA expression in men with isolated HGPIN, whereas the increased PSCA mRNA expression after therapy may be a clinically adverse predictor for cancer onset.     

Prostate stem cell antigen: Identification of immunogenic peptides and assessment of reactive CD8+ T cells in prostate cancer patients

Identification of TAAs recognized by CD8(+) CTLs paved the way for new concepts in cancer therapy. In view of the heterogeneity of tumors and their diverse escape mechanisms, CTL-based cancer therapy largely depends on an appropriate number of TAAs. In prostate cancer, the number of antigens defined as suitable targets of CTLs remains rather limited. PSCA is widely distributed in prostate cancer. In this report, we define immunogenic peptides of PSCA which are recognized by circulating CD8(+) T cells from prostate cancer patients and able to activate CTLs in vitro. Screening the amino acid sequence of PSCA for peptides containing a binding motif for HLA-A*0201 resulted in 8 candidate peptides. Specificity and affinity of peptide binding were verified in a competition assay. Frequencies of CD8(+) T lymphocytes reactive against selected epitopes were determined in the blood of prostate cancer patients using the ELISPOT assay. Increased frequencies were revealed for CD8(+) T cells recognizing the peptides ALQPGTALL and AILALLPAL. CTLs from prostate cancer patients were raised against these 2 peptides in vitro when presented by autologous DCs. They specifically recognized peptide-pulsed T2 target cells and prostate cancer cells that were HLA-A*0201- and PSCA-positive, indicating that these peptides were naturally generated by tumor cells. These data suggest that PSCA is a promising target for the immunotherapy of prostate cancer.     

Transrectal ultrasound in detecting prostate cancer compared with serum total prostate-specific antigen levels

We carried out a retrospective study to review the efficiency of grey-scale transrectal ultrasonography (TRUS) in detecting prostate cancer compared with the data in recent published work, including alternative imaging methods of the prostate gland. Our study group consisted of 830 patients who underwent TRUS-guided biopsy of the prostate between May 2000 and June 2004. The relation between abnormal TRUS findings and serum total prostate-specific antigen (tPSA) levels was evaluated in patients with prostate cancer who were divided into three different groups according to serum tPSA levels. Group I included patients with tPSA levels of 4-9.9 ng/mL, group II included tPSA levels of 10-19.9 ng/mL and group III included patients with tPSA levels of 20 ng/mL or more. In general, TRUS detected 185 (64%) of 291 cancers with a specificity of 89%, a PPV of 76% and an accuracy of 80%. TRUS findings enabled the correct identification of 22 (56%) of the 39 cancers in group I, 28 (30%) of the 93 cancers in group II and 135 (85%) of the 159 cancers in group III. In conclusion, TRUS alone has a limited potential to identify prostate cancer, especially in patients with tPSA levels lower than 20 ng/mL. Therefore, increased numbers of systematically placed biopsy cores must be taken or alternative imaging methods are required to direct TRUS-guided biopsy for improving prostate cancer detection.     

Prostate cancer progression in the presence of undetectable or low serum prostate-specific antigen level

BACKGROUND: The serum prostate-specific antigen (PSA) level after definitive treatment for prostate cancer (PC) is a powerful predictor of outcome. Occasionally, PC progression can occur despite low or undetectable PSA levels. The authors report on the clinical and pathologic characteristics of patients who experienced PC progression with undetectable or low PSA levels. METHODS: From an electronic database of all patients with PC who were treated at The University of Texas M. D. Anderson Cancer Center between 1999 and 2004, a group of 46 patients was identified who had progression to metastatic PC detected with concomitant PSA levels from 0.1 ng/mL to 2 ng/mL. Patient charts were reviewed for tumor stage, Gleason score, pretreatment PSA level, and the presence of atypical histologic variants (ie, ductal, sarcomatoid, or small cell cancers). The nadir PSA level after treatment and the PSA level at the time metastatic PC was detected were determined. The patients were followed semiannually, and imaging studies were obtained at the discretion of treating physicians. The sites of metastasis and histologic confirmation were reported when available. RESULTS: Twenty-three of 46 patients underwent radical prostatectomy, 11 patients received radiation therapy, and 12 received hormone treatment as their initial form of therapy. Progression to metastatic disease with concomitant, undetectable PSA levels occurred in 10 patients, including 3 patients who had not received treatment with hormones. The sites of metastasis included bone (n = 35 patients), liver (n = 7 patients), retroperitoneal lymph nodes (n = 5 patients), lungs (n = 4 patients), and brain (n = 1 patient). Aggressive and locally advanced PC were common features in these patients: Eighty-five percent had Gleason scores >or=7, 63% had clinical T3 or T4 tumors, and 41% had pretreatment PSA levels >10 ng/mL. Atypical histologic variants were observed in 21 patients (46%) and in 8 of 10 patients who progressed with undetectable PSA levels. In 10 patients (22%), metastasis were detected in the presence of an undetectable PSA level. Eight of those patients had small cell carcinoma. In 19 patients (41%), progression to metastasis occurred without any increase in their PSA from the nadir level. Thirty-one patients (67%) were asymptomatic at the time metastasis was detected, and the detection of metastasis in these patients occurred only because of routine imaging studies. CONCLUSIONS: Progression of PC may occur despite undetectable or low PSA levels. Complete physical evaluation and imaging studies may be indicated in the surveillance of patients with high-grade, locally advanced tumors, especially when atypical histologic variants are present.     

Vaccination of advanced prostate cancer patients with PSCA and PSA peptide-loaded dendritic cells induces DTH responses that correlate with superior overall survival

Prostate stem cell antigen (PSCA) and prostate-specific antigen (PSA) are overexpressed in most prostate cancers. PSCA- and PSA-derived, HLA-A2 binding peptides are specific targets for T-cell responses in vitro. A phase I/II trial was performed to demonstrate feasibility, safety and induction of antigen-specific immunity by vaccination with dendritic cells (DC) presenting PSCA and PSA peptides in patients with hormone- and chemotherapy-refractory prostate cancer. Patients received 4 vaccinations with a median of 2.7 x 10(7) peptide-loaded mature DC s.c. in biweekly intervals. Clinical responses were assessed 2 weeks after the 4th vaccination. Immune monitoring was performed by DTH and HLA multimer analysis. Twelve patients completed vaccination without relevant toxicities. Six patients had stable disease after 4 vaccinations. One patient had a complete disappearance of lymphadenopathy despite rising PSA. Four patients with SD and 1 progressor developed a positive DTH after the 4th vaccination. With a median survival of all patients of 13.4 months, DTH-positivity was associated with significantly superior survival (p = 0.003). HLA tetramer analysis detected high frequencies of peptide-specific T cells after 2 vaccinations in 1 patient who was also the sole responder to concomitant hepatitis B vaccination as an indicator of immune competence and survived 27 months after start of vaccination. Vaccination with PSA/PSCA peptide-loaded, autologous DCs may induce cellular responses primarily in immunocompetent patients, which appear to be associated with clinical benefit. Testing of DC-based vaccination is warranted for patients at earlier stages of prostate cancer.     

Clinical significance of the LacdiNAc‐glycosylated prostate‐specific antigen assay for prostate cancer detection

To reduce unnecessary prostate biopsies (Pbx), better discrimination is needed. To identify clinically significant prostate cancer (CSPC) we determined the performance of LacdiNAc‐glycosylated prostate‐specific antigen (LDN‐PSA) and LDN‐PSA normalized by prostate volume (LDN‐PSAD). We retrospectively measured LDN‐PSA, total PSA (tPSA), and free PSA/tPSA (F/T PSA) values in 718 men who underwent a Pbx in 3 academic urology clinics in Japan and Canada (Pbx cohort) and in 174 PC patients who subsequently underwent radical prostatectomy in Australia (preop‐PSA cohort). The assays were evaluated using the area under the receiver operating characteristics curve (AUC) and decision curve analyses to discriminate CSPC. In the Pbx cohort, LDN‐PSAD (AUC 0.860) provided significantly better clinical performance for discriminating CSPC compared with LDN‐PSA (AUC 0.827, P = 0.0024), PSAD (AUC 0.809, P < 0.0001), tPSA (AUC 0.712, P < 0.0001), and F/T PSA (AUC 0.661, P < 0.0001). The decision curve analysis showed that using a risk threshold of 20% and adding LDN‐PSA and LDN‐PSAD to the base model (age, digital rectal examination status, tPSA, and F/T PSA) permitted avoidance of even more biopsies without missing CSPC (9.89% and 18.11%, respectively vs 2.23% [base model]). In the preop‐PSA cohort, LDN‐PSA values positively correlated with tumor volume and tPSA and were significantly higher in pT3, pathological Gleason score ≥ 7. Limitations include limited sample size, retrospective nature, and no family history information prior to biopsy. LacdiNAc‐glycosylated PSA is significantly better than the conventional PSA test in identifying patients with CSPC. This study was approved by the ethics committee of each institution (“The Study about Carbohydrate Structure Change in Urological Disease”; approval no. 2014‐195).     

Combining 33 genetic variants with prostate-specific antigen for prediction of prostate cancer: longitudinal study

The aim of this study was to investigate if a genetic risk score including 33 common genetic variants improves prediction of prostate cancer when added to measures of prostate-specific antigen (PSA). We conducted a case-control study nested within the Northern Sweden Health and Disease Cohort (NSHDC), a prospective cohort in northern Sweden. A total of 520 cases and 988 controls matched for age, and date of blood draw were identified by linkage between the regional cancer register and the NSHDC. Receiver operating characteristic curves with area under curve (AUC) estimates were used as measures of prostate cancer prediction. The AUC for the genetic risk score was 64.3% [95% confidence interval (CI) = 61.4-67.2], and the AUC for total PSA and the ratio of free to total PSA was 86.2% (95% CI = 84.4-88.1). A model including the genetic risk score, total PSA and the ratio of free to total PSA increased the AUC to 87.2% (95% CI = 85.4-89.0, p difference = 0.002). The addition of a genetic risk score to PSA resulted in a marginal improvement in prostate cancer prediction that would not seem useful for clinical risk assessment.     

Induction of prostate specific antigen production by steroids and tamoxifen in breast cancer cell lines

Summary We demonstrate that the steroid hormone receptor-positive breast carcinoma cell lines T-47D and MCF-7 can be induced by androgens, progestins, mineralocorticosteroids, glucocorticosteroids, and antiestrogens, to produce prostate specific antigen (PSA). Estrogens failed to induce such stimulation in both cell lines and, in addition, were able to block the induction by androgens in the cell line T-47D. These data support and extend our previous report on PSA production by breast tumors and describe anin vitro system which can be used to study the phenomenon for possible application in prognosis and design of new therapy.     

前列腺癌PC-3细胞株蛙皮素受体的检测

目的:观察前列腺癌PC-3细胞株蛙皮素(Bombesin,BBS)受体蛋白和受体mRNA的表达。方法:采用免疫组织化学方法检测PC-3细胞中蛙皮素受体蛋白的表达,逆转录聚合酶链反应(RT-PCR)观察前列腺癌PC-3细胞株蛙皮素受体(BBS-R)mRNA的表达。结果:免疫组化方法检测PC-3细胞中有BBS-R蛋白的表达;RT-PCR产物与预期的BBS-R的cDNA分子量完全相符。结论:实验证明PC-3细胞存在有蛙皮素特异性受体,为探索蛙皮素和蛙皮素受体的拮抗剂应用于肿瘤研究以及蛙皮素作用后细胞内信息传递途径提供了基础。     

实时荧光定量逆转录聚合酶链反应检测结肠癌中Syndecan-1 m RNA和HPA-1 m RNA的表达及临床意义

背景与目的:侵袭转移是导致结肠癌死亡率增加的主要原因,如何阻断肿瘤的侵袭转移成为目前研究的热点。本研究旨在检测Syndecan-1基因和HPA-1基因在结肠癌组织中的表达水平,探讨二者与结肠癌侵袭转移及预后的关系。方法:用实时荧光定量逆转录聚合酶链反应(RT-PCR)分别检测49例结肠癌、49例配对的癌旁组织(距癌2cm)和49例配对远离结肠癌的手术切缘正常组织(距癌5cm以上)的Syndecan-1和HPA-1基因的表达水平,分析二者与结肠癌临床病理特征的关系。结果:结肠癌中HPA-1mRNA的表达水平(40.56±11.75)显著高于癌旁组织(18.28±11.33)和正常组织(10.80±10.20)(P均<0.001),癌旁组织明显高于正常组织(P<0.05);正常结肠组织中Syndecan-1mRNA表达水平(61.21±12.96)显著高于癌旁组织(14.35±11.06)和结肠癌组织(10.12±8.58)(P均<0.001),癌旁组织明显高于结肠癌组织(P<0.05)。Syndecan-1mRNA的表达减弱和HPA-1的表达增强与肿瘤的分化程度、浸润深度、淋巴结转移、远处转移及TNM分期显著相...