Androgen receptor amplification is associated with increased cell proliferation in prostate cancer

Mechanisms of prostate cancer progression during hormonal therapy and the pathobiologic consequences of androgen receptor (AR) gene amplification are inadequately known. To further investigate the hypothesis that AR gene amplification is associated with increased cell proliferation, we analyzed 123 paraffin-embedded prostate cancer specimens from men who experienced tumor relapse during androgen withdrawal therapy. We used fluorescence in situ hybridization to quantify AR gene copy number and Ki-67 immunohistochemistry to determine cell proliferation. One third of the tumors showed AR gene amplification. Among tumors with AR amplification, the mean cell proliferation rate was 19.8 (SD, 12.3; 95% confidence interval [CI], 15.4-24.1), whereas it was 13.0 (SD, 15.9; 95% CI, 9.1-16.8) in tumors without amplification (P = .032). In the best fitting logistic regression model, only proliferation remained significant (P = .040). When the median Ki-67 labeling index (6.7%) of all tumors was used as a cutoff point, the tumors with AR amplification were more frequently highly proliferating than tumors with no amplification (P = .010; odds ratio, 3.4; 95% CI, 1.4-8.3). Our results imply that progression of prostate cancer during androgen withdrawal therapy is associated with AR gene amplification and increased cell proliferation rate in one third of tumors. We suggest that AR gene amplification is an important molecular mechanism underlying the increase in proliferation rate of a substantial fraction of recurrent prostate carcinomas. However, efforts should be targeted to develop prostate cancer cell lines to study causal relationships between AR gene amplification and various biologic variables.     

Down-regulation of beta 1C integrin, an inhibitor of cell proliferation, in prostate carcinoma.

The beta 1C integrin, a member of the cell adhesion receptor superfamily, is an alternatively spliced variant of the beta 1A subunit and, in contrast to its wild-type counterpart, inhibits cell proliferation in vitro. The expression of beta 1C integrin in tumor cell growth was investigated. In benign and neoplastic human prostate tissues, immunohistochemical analysis performed using affinity-purified antibodies specific for beta 1C demonstrated a predominant epithelial expression of beta 1C in benign prostate glands with marked staining of the apical, basal, and lateral surfaces. In the adjacent prostate adenocarcinoma glands, the beta 1C variant was dramatically down-regulated in 27 of 34 (79%) analyzed cases, whereas the expression and distribution of its wild-type counterpart, beta 1A, remained unchanged. Tumors exhibiting different Gleason's patterns showed that beta 1C was down-regulated in comparison with the benign tissue regardless of the histological grade. Immunoblotting analysis, using affinity-purified antibodies specific for beta 1C, was performed, in a quantitative manner, to compare beta 1C expression in benign and tumor prostate tissue. The results showed that beta 1C was expressed in benign prostate tissue whereas it was undetectable in prostate adenocarcinoma. Taken together, these data show that beta 1C integrin down-regulation in prostate tissues correlates with a neoplastic phenotype consistent with its in vitro growth-inhibitory properties. These findings indicate a novel pathophysiological role for this integrin variant in tumorigenesis.     

Analysis of Gleason grade and scores in 90 Nigerian Africans with prostate cancer during the period 1994 to 2004

Objectives

To determine the relative frequency of prostate cancer among surgical specimens, and among prostate specimens received at the pathology department ,University Hospital Calabar.

Methods

Histology records were reviewed for the following: total number of histology specimens received; total number of prostate specimens; total number of prostate cancer; and the total number of cancers in males during the study period. Histology sections 4–5microns thick were cut from paraffin blocks and stained by Haematoxylin and Eosin (H&E). Histopathologic specimens were classified using the grading system of tumour differentiation described by Gleason and associates.

Results

One hundred and twenty three cancers of the prostate were received, constituting 2% of the total surgical specimens and 31% of prostate specimens. Thirty three cases (27%) could not be analyzed; therefore the study is based on 90 prostate cancer specimens. Eighty nine (99%) cases were epithelial tumours (adenocarcinoma.) There was a single mesenchymal tumour (rhabdomyosarcoma) (1%). The commonest grade in this study was the high grade (Gleason grade IV).

Conclusions

We observed that prostate cancer is a common among males (all sites) diagnosed at the University Hospital Calabar, with a peak incidence between the ages of 61 – 70 years (seventh decade).     

lncRNA PCAT1表达下调抑制口腔鳞状细胞癌细胞的增殖、生长、侵袭、迁移及上皮-间充质转化

目的:探讨长链非编码RNA(long non-coding RNA,lncRNA) PCAT1对口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)细胞的增殖、生长、侵袭及迁移的影响,并探讨其可能机制。方法:采用Lipofectamine 200将PCAT1 siRNA转染入OSCC细胞分别利用RT-qPCR和Western blot检测相关基因的mRNA及蛋白表达;分别利用CCK-8实验和集落形成实验检测OSCC细胞的增殖及生长能力;利用细胞侵袭实验和细胞迁移实验检测OSCC细胞的侵袭及迁移能力。结果:PCAT1在OSCC组织和细胞中的表达与癌旁正常组织和正常口腔细胞黏膜角质细胞相比显著上调(P 0. 05)。转染PCAT1 siRNA可以显著降低PCAT1在Tca8113和TSCCa细胞中的表达(P 0. 05)。PCAT1的低表达可以显著抑制Tca8133和TSCCa细胞的增殖、生长、侵袭及迁移(P 0. 05)。PCAT1在Tca8113和TSCCa细胞中的低表达可以抑制ZEB1、N-cadherin和vimentin的mRNA及蛋白表达,同时增加E-cadherin的mRNA及蛋白表达(P 0. 05)。结论:沉默PCAT1能够抑制OSCC细胞的增殖、生长及转移,该作用可能与调控上皮-间充质转化有关。     

Prognostic significance of architectural subtypes of Gleason grade 4 prostate cancer in radical prostatectomy: A semiquantitative method of evaluation

Studies have shown that Gleason grade 4 extent as well as architectural subtypes provide prognostic information. We aimed to evaluate the influence on biochemical recurrence following radical prostatectomy of patients with organ-confined tumor, Gleason score 7, and negative surgical margins. Total tumor extent, Gleason grade 4 total extent and the extent of each architectural subtype (fused glands, poorly defined glands, cribriform glands, and glomeruloid glands) were evaluated by a semiquantitative point-count method using different colors to identify each subtype. Microscopic morphology of glomeruloid glands was considered regardless of morphology: size (small or large), attachment (narrow or extensive), and cribriform or solid intraluminal protrusion. Gleason grade 4 total extent significantly predicted shorter time to biochemical recurrence in univariate and multivariate analysis. Stratifying extent, Gleason grade 4 with >30% of the total grade 4 extent was significantly predictive for time of recurrence. Considering architectural subtypes, cribriform and glomeruloid glands but not fused and poorly formed glands extent, significantly predicted shorter time to recurrence in univariate analysis. An important issue related to the studies on prognostic significance of Gleason grade 4 subtypes is the lack of uniformity in the definition of microscopic morphology of the subtypes particularly of the glomeruloid architecture.     

Reelin expression in human prostate cancer: a marker of tumor aggressiveness based on correlation with grade.

Reelin is a glycoprotein that plays a critical role in the regulation of neuronal migration during brain development and, since reelin has a role in the control of cell migration, it might represents an important factor in cancer pathology. In this study, 66 surgical specimens of prostate cancer were analyzed for reelin expression by immunohistochemical method. The reelin expression was correlated with Gleason score and individual Gleason patterns. Reelin expression was found in 39% prostate cancers. Stromal tissues, normal epithelial cells and prostate intraepithelial neoplasia (PIN) of any grade around and distant from cancer were always negative for reelin. Reelin was found in malignant prostatic epithelial glands of 50% cases Gleason score 10, 52% Gleason score 9, 56% Gleason score 8, 18% Gleason score 7, while no sample of prostate cancers with Gleason score 6 showed reelin expression (P=0,005). As reelin staining is frequently found in high Gleason score prostate cancers, we explored whether reelin expression is influenced by single Gleason patterns. While Gleason 3 pattern did not show reelin immunoreactivity, reelin expression was found in 35% Gleason 4 patterns and 45% Gleason 5 patterns (P<0.001). Our results demonstrated for the first time that reelin is expressed in prostate cancer and not in benign prostate tissue and its expression occurs in higher Gleason score and correlates significantly with increasing of single Gleason patterns. This suggests reelin may behave as a specific histological marker and may represent a useful biomarker to predict aggressive phenotypic behavior of prostatic cancer cells.     

Expression of carcinoembryonic antigen-related cell adhesion molecule 1(CEACAM1) and its correlation with angiogenesis in gastric cancer

Objective

To examine the expression of carcinoembryonic antigen-related cell adhesion molecule 1(CEACAM1) and CD34 in gastric adenocarcinoma, and to investigate their relations with clinical pathology-related factors.

Methods

Immunohistochemistry (IHC) was used to analyze the expression of CEACAM1 and CD34, and micro-vessel density (MVD) marked by CD34 was calculated in 208 cases of human gastric adenocarcinoma and in 56 cases of normal human gastric tissues.

Results

There was no expression of CEACAM1 in normal gastric mucosa. However, all of the gastric adenocarcinoma tissues expressed CEACAM1 with cytoplasmic and/or membranous staining. CEACAM1 expression was classified as high and low (137/208 vs. 71/208, 65.9% vs. 34.1%), the CD34-MVD value was significantly different between the two groups (P < 0.05). In addition, expressions of CEACAM1 and CD34 were significantly different from gastric adenocarcinoma to normal gastric tissues, respectively (P < 0.05). High CEACAM1 expression and high MVD value were positively associated with lymph nodes metastasis and TNM stage, but negatively related to pathological grade (P < 0.05). But they were irrelevant with tumor size, patients’ age and gender (P > 0.05).

Conclusions

The up-regulation of CEACAM1 expression may participate in tumorous angiogenesis, especially high expression of CEACAM1 promoted its capability of invasion and metastasis.     

Comparative influence of cribriform growth and percent Gleason 4 in prostatic biopsies with Gleason 3+4 cancer

The International Society of Urological Pathology endorses specifying presence of cribriform architecture in Gleason (G)4 prostate cancer because of cribriform's aggressiveness. The relative effect of cribriform presence versus percentage G4 within grade group (GG)2 or 3 was uncertain.194 men's biopsies with GG2 with or without cribriform (excluding glomeruloid from cribriform) and GG3 without cribriform (controls) from 4 years were reviewed. 173 cases had follow-up including 147 GG2 (15/147 or 10% had cribriform) and 26 GG3. Effects of total tumor specimen involvement, %Gleason 4, and cribriform were stratified into prostatectomy (n = 90), radiotherapy (n = 61), and watching waiting (n = 22) groups.Median follow-up duration was 3.32 years (range 1.90–6.18). Biochemical failures in the above 3 cohorts numbered 9 (9/90; 10%), 5 (5/61; 8%), and 13 (13/22; 59%) respectively. In all groups, (GG2+ GG3, n = 173), the HR for C pattern was 1.64. In GG2, cribriform presence (considering glomeruloid as non-cribriform) conferred a hazard ratio (HR) of 1.51 (p = 0.48). It was 1.38, excluding glomeruloid. In watchful waiting cohort only, presence of C conferred a HR of 2.62 (p = 0.086). All remaining comparisons including percent G4, remained not significant.Thus, only in WW group did cribriform pattern presence approach significance. Detection of differences otherwise was not feasible, probably because: 1) biochemical failure is too rare in GG2 cancer; 2) cribriform frequency was only 10% in GG2 (in current study), less than in higher-grade cancer. 3) Use of biopsy tissue is subject to sampling variation which may undersample cribriform pattern, though biopsy forms the basis of treatment decisions.     

Chrysin reduces proliferation and induces apoptosis in the human prostate cancer cell line pc-3

INTRODUCTION:

Honey is a common household product with many medicinal uses described in traditional medicine. Only recently has its antioxidant properties and preventive effects against disease been highlighted. Chrysin is a natural flavone commonly found in honey that has been shown to be an antioxidant agent. In this study, we investigated the antiproliferative and apoptotic effects of honey and chrysin on cultured human prostate cancer cells.

METHODS:

Cells were cultured in RPMI medium and treated with different concentrations of honey and chrysin for three consecutive days. Cell viability was quantitated by the 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. The percentage of apoptotic cells was determined by flow cytometry using Annexin V-fluorescein isothiocyanate.

RESULTS:

The MTT assay revealed that both compounds had an antiproliferative effect on PC-3 cells in a dose- and time-dependent manner. The IC₅₀ values for honey and chrysin against PC-3 cells were 2.5% and 24.5% after 48 h and 1.8% and 8.5% after 72 h, respectively. Chrysin induced apoptosis in PC-3 cells, as determined by flow cytometry.

CONCLUSION:

Our results suggest that honey has anti-proliferative effects on prostate cancer cells and the effects are mainly due to chrysin. Therefore, chrysin may be a potential compound for both cancer prevention and treatment. Further in vivo investigation is needed to support the use of chrysin in cancer therapy.     

Foamy gland adenocarcinoma of the prostate: incidence, Gleason grade, and early clinical outcome

Foamy gland carcinoma is a variant of prostatic acinar adenocarcinoma characterized by abundant foamy cytoplasm and often pyknotic nuclei. Limited data exist regarding outcome and the clinicopathologic attributes of this variant. We screened 477 radical prostatectomies for foamy gland carcinoma to determine the incidence, amount, and Gleason grade/score of foamy gland carcinoma within the prostate. Time until prostate-specific antigen biochemical recurrence after radical prostatectomy was compared for both foamy and control/nonfoamy cases. For validation of incidence, Gleason grade, and pathologic stage, a second series of 100 consecutive radical prostatectomies was screened for foamy gland carcinoma. Foamy gland carcinoma was found in 69 (14.5%) of 477 cases. The median Gleason score of the foamy component was 7, which was not significantly different from the Gleason score of the nonfoamy component within those cases or the 408 nonfoamy cases. The most common Gleason score was 7 (44/69). There was no difference between foamy gland and nonfoamy gland cases in recurrence rate (23% versus 22%) or the average time to prostate-specific antigen recurrence (130 versus 151 months). In the second series, foamy gland carcinoma was found in 23% of cases and had a median Gleason score of 7; and the most common Gleason score was 7 (11/23). Foamy gland carcinoma exists in a significant subset of prostatic carcinomas. This variant does not appear to harbor a different prognosis compared with usual acinar adenocarcinoma, but diagnostic recognition of foamy gland carcinoma is important because there is a Gleason grade 4 element in the majority of cases.     

Amplification and overexpression of vinculin are associated with increased tumour cell proliferation and progression in advanced prostate cancer

Androgen withdrawal is the standard treatment for advanced prostate cancer. Although this therapy is initially effective, nearly all prostate cancers become refractory to it. Approximately 15% of these castration-resistant prostate cancers harbour a genomic amplification at 10q22. The aim of this study was to explore the structure of the 10q22 amplicon and to determine the major driving genes. Application of high-resolution array-CGH using the 244k Agilent microarrays to cell lines with 10q22 amplification allowed us to narrow down the common amplified region to a region of 5.8 megabases. We silenced each of the genes of this region by an RNAi screen in the prostate cancer cell lines PC-3 and 22Rv1. We selected genes with a significant growth reduction in the 10q22 amplified cell line PC-3, but not in the non-amplified 22Rv1 cells, as putative target genes of this amplicon. Immunohistochemical analysis of the protein expression of these candidate genes on a tissue microarray enriched for 10q22 amplified prostate cancers revealed vinculin as the most promising target of this amplicon. We found a strong association between vinculin gene amplification and overexpression (p < 0.001). Further analysis of 443 specimens from across all stages of prostate cancer progression showed that vinculin expression was highest in castration-resistant prostate cancers, but negative or very low in benign prostatic hyperplasia (p < 0.0001). Additionally, high tumour cell proliferation measured by Ki67 expression was significantly associated with high vinculin expression in prostate cancer (p < 0.0001). Our data suggest that vinculin is a major driving gene of the 10q22 amplification in prostate cancer and that vinculin overexpression might contribute to prostate cancer progression by enhancing tumour cell proliferation.     

Nitric oxide synthase in human breast cancer is associated with tumor grade, proliferation rate, and expression of progesterone receptors.

Nitric oxide (NO) is generated by a family of isoenzymes named nitric oxide synthases (NOS) which includes a cytokine-inducible form, NOSII. NO is a free radical known to inhibit cell proliferation, to induce apoptosis, and to be a mediator of macrophage cytostatic and cytotoxic effects. We investigated NOS in 40 human breast carcinomas and 8 benign breast lesions. NOSII was localized in tumor cells by immunohistochemistry. NOS activity, measured with the citrulline assay, was detected in 27 of 40 tumors. Neither immunohistologic labeling nor NOS activity was detected in benign samples. NOS labeling and activity were significantly related (p < 0.02). For the first time, a significant negative relationship between NOS activity and tumor cell proliferation (p < 0.002) was found. We also showed that tumors with high NOS activity expressed progesterone receptors (p < 0.04). These results are consistent with the observation of high NOS activity in tumors with low grade (p < 0.05). These in vivo observations were related to in vitro data: cytokines (IL-1beta, IFN-gamma, and TNF-alpha) induced NOSII expression in human MCF-7 breast cancer cells, and NO inhibited their proliferation. Thus, we show herein that tumors with high NOS activity have low proliferation rate and low grade, which correlates with the in vitro observation of the inhibition of proliferation of human breast cancer cells by NO. These results may have future therapeutic implications.     

p53 gene mutational rate,Gleason score,and BK virus infection in prostate adenocarcinoma: Is there a correlation?

Prostate cancer represents the second leading cause of cancer deaths in Western countries. Viral infections could play a role in prostate carcinogenesis. Human polyomavirus BK (BKV) is a possible candidate because of its transforming properties. In this study, BKV sequences in urine, blood, fresh, and paraffin‐embedded prostate cancer samples from 26 patients were searched using Q‐PCR analysis. T antigen (TAg) and p53 localization in neoplastic cells were evaluated by immunohistochemical analysis. Also, the presence of mutations in 5–9 exons of p53 gene was analyzed. Results showed that BKV‐DNA was found in urine (54%), plasma (31%), and in fresh prostate cancer specimens (85%). The analysis of p53 gene evidenced several mutations in high Gleason patients, according to tumor advanced stage. Immunohistochemical analysis results evidenced the localization of p53 and TAg into cytoplasm, whereas in TAg‐negative tumors, p53 was nuclear. This study suggests that BKV acts as cofactor in the pathogenesis of prostate cancer. These observations emphasize previous studies regarding the cellular pathways that may be deregulated by BKV. J. Med. Virol. 80:2100–2107, 2008. © 2008 Wiley‐Liss, Inc.     

Numerical chromosomal aberrations in prostate cancer: correlation with morphology and cell kinetics

Eleven routinely processed radical prostatectomy specimens were studied for the presence of numerical chromosomal aberrations by means of in situ hybridization with nucleic acid probes specific for chromosomes 7, 10, 17, X, and Y. Cytogenetic information was correlated with morphology, tumour stage and volume as well as with cell kinetics, the latter being assessed by immunohistochemistry with antibodies raised against the proliferative cell nuclear antigen (PCNA) and against a formalin-resistant epitope of the Ki-67 antigen, MIB 1. In 5 of 11 cases, numerical aberrations of at least one chromosome were found. The cases with normal chromosome numbers were those with the smallest volumes of Gleason grade 4 and/or 5 tumour (mean 0.5 cm³) and represented tumours restricted to the prostate. Tumours with aberrations in the number of detected chromosomes showed advanced stages and large volumes of high-grade tumour (mean 12.5 cm³). All 4 tumours with positive surgical margins were recruited from a group with marked local heterogeneity in chromosome numbers. Immunostaining with MIB 1 and PCNA was most intense in areas of high-grade tumour and was positively correlated with the emergence of chromosomal aberrations. The data suggest that the appearance of numerical chromosomal aberrations in prostate cancer coincides with aggressive tumour behaviour and could be used as an additional prognostic marker.This work is part of E.K.'s doctoral thesis     

High expression of miR-21 in tumor stroma correlates with increased cancer cell proliferation in human breast cancer

Low-risk and high-risk breast cancer patients are stratified primarily according to their lymph node (LN) status and grading. However, some low-risk patients relapse, and some high-risk patients have a favorable clinical outcome, implying a need for better prognostic and predictive tests. Micro RNAs are often aberrantly expressed in cancer and microRNA-21 is upregulated in a variety of cancers, including breast cancer. High miR-21 levels have been associated with poor prognosis. To determine the cellular localization of miR-21 and to compare its expression levels with histopathological features, we performed in situ hybridization and semi-quantitative assessment of the miR-21 signal on 12 LN negative grade I (assumed low risk), and 12 LN positive grade II (high risk) breast cancers. miR-21 was predominantly seen in cancer associated fibroblast-like cells, with no difference in expression levels between grade I and grade II carcinomas. Immunohistochemical scoring of the prognostic proliferation marker Ki-67 and tumor suppressor p53 showed that the miR-21 expression levels significantly correlated with the Ki-67 score (p = 0.043), whereas no correlation between p53 and miR-21 was found. Our results indicate that miR-21 may contribute to improve clinical stratification according to growth rate and facilitate tailored treatment of breast cancer patients.     

前列腺癌组织中人腺体激肽释放酶2基因表达值与Gleason评分的相关性分析

目的探讨人腺体激肽释放酶(hK)2基因表达值与前列腺癌的Gleason评分的相关性及临床意义.方法运用实时荧光定量(FQ)PCR方法检测40例已知Gleason评分前列腺癌病理组织中hK2的基因表达值.结果前列腺癌组织中hK2基因表达值在不同的Gleason评分中有差异,随Gleason评分值升高而升高.结论前列腺癌组织中hK2基因表达值与Gleason评分呈正相关;hK2有望成为前列腺癌早期诊断,恶性程度评估以及预后判断的重要指标.