Biomedical subjects

Lars Egevad

Publications and source records attributed to Lars Egevad.

At least 19 recordsLinked to original sources

PubMed2006

CD4+CD25high T cells are enriched in the tumor and peripheral blood of prostate cancer patients.

In this study, we investigated whether CD4+CD25high regulatory T cells (Treg) are increased in the tumor tissue and peripheral blood of early-stage prostate cancer patients undergoing prostatectomy. We show that the prevalence of CD4+CD25high T cells inside the prostate was significantly higher in the tumor compared with benign tissue from the same prostate. Furthermore, the frequency of CD4+CD25high T cells in peripheral blood was significantly higher in prostate cancer patients compared with normal donors. A proportion of the CD4+CD25high T cells was also shown to be glucocorticoid-induced TNF receptor, ICOS, and FOXP3 positive. Moreover, CD4+CD25+ T cells from blood and supernatants from cultured prostate tumor tissue samples exhibited immunosuppressive function in vitro. Furthermore, supernatants from cultured prostate tissue samples and prostate cancer ascites fluid induced migration of CD4+CD25+ T cells and were shown to contain the regulatory T cell chemokine CCL22 by ELISA. Our findings indicate that Tregs are an important cellular component of early-stage prostate tumors, and thus new therapeutic strategies aimed at inhibition or depletion of Tregs may improve prostate cancer immunotherapy.

Aged↗

PubMed2006

The significance of modified Gleason grading of prostatic carcinoma in biopsy and radical prostatectomy specimens.

At an International Society of Urological Pathology consensus conference in 2005, the Gleason grading system for prostatic carcinoma underwent its first major revision. Gleason pattern 4 now includes most cribriform patterns and also fused and poorly formed glands. Our aims were to compare the grade distributions and assess the agreement between biopsy and radical prostatectomy specimens for the modified and conventional Gleason grading. More than 3,000 radical prostatectomy (RP), needle biopsies (NB) and transurethral resection specimens were assigned modified Gleason score (GS). In NB, modified GS 3 + 3 = 6 and 3 + 4 = 7a were almost equally common, while in RP, 3 + 4 = 7a was most common followed by 4 + 3 = 7b. After application of the modified GS on NB, a substantial shift in GS distribution occurred: The proportion of GS 6 and 7 were 48 and 26%, respectively, with conventional Gleason grading as compared to 22 and 68%, respectively, with modified grading. In 368 men, the agreement between NB and RP with a modified GS 6, 7a, 7b and 8-10 in NB was 28, 88, 68 and 64-100%, respectively. The overall agreement improved from 58 to 72% (p < 0.001) compared to conventional GS. The higher agreement with modified Gleason grading may facilitate therapeutic decisions.

Biopsy↗

PubMed2006

Tumor specific phage particles promote tumor regression in a mouse melanoma model.

Within cancer research, phage display libraries have been widely used for the identification of tumor targeting peptides and antibodies. Additionally, phages are known to be highly immunogenic; therefore we evaluated the immunotherapeutic potential of tumor specific phages to treat established solid tumors in a mouse model of melanoma. We developed two tumor specific phages, one derived from a peptide phage display library and one Fab expressing phage with known specificity, for the treatment of mice bearing palpable B16-F10 or B16/A2K(b) tumors. Therapy in B16-F10 tumor bearing mice with tumor specific phages was superior to treatment with non-tumor specific phages and lead to delayed tumor growth and increased survival. In B16/A2K(b )tumor bearing mice, therapy with tumor specific phages resulted in complete tumor regression and long-term survival in 50% of the mice. Histological analysis of tumors undergoing treatment with tumor specific phages revealed that phage administration induced a massive infiltration of polymorphonuclear neutrophils. Furthermore, phages induced secretion of IL-12 (p70) and IFN-gamma as measured in mouse splenocyte culture supernatants. These results demonstrate a novel, immunotherapeutic cancer treatment showing that tumor specific phages can promote regression of established tumors by recruitment of inflammatory cells and induction of Th1 cytokines.

Animals↗

PubMed2006

Tissue shrinkage after fixation with formalin injection of prostatectomy specimens.

Prostate cancer volume correlates with stage, grade, and progression after prostatectomy. When tumor volume is measured planimetrically, results are multiplied by a correction factor to compensate for tissue shrinkage caused by processing. Injection of formalin into prostatectomy specimens was suggested for improved fixation. Our aim was to investigate how this affects the prostate volume. We studied 142 radical prostatectomy specimens. All prostates were immersed in 10% formalin. In 84 prostates (59%) we also injected 20 ml of formalin before routine fixation. The prostates were weighed unfixed after injection and after final fixation. The specimens were sliced and totally embedded. The transverse diameters of the prostates were measured on unfixed specimens and microscopic sections. The average weight loss after final fixation was 5.8 and 8.6% for formalin-injected specimens and standard-fixed specimens, respectively (p<0.001). However, when total shrinkage was estimated from the transverse diameters, there was no difference related to fixation technique (p=0.59). The average linear shrinkage was 4.5%, corresponding to a volume correction factor of 1.15. We conclude that formalin injection for fixation of prostate tissue does not influence tumor volume calculation compared to conventional fixation.

Artifacts↗

PubMed2006

Switch to full-length of XAF1 mRNA expression in prostate cancer cells by the DNA methylation inhibitor.

X-linked inhibitor of apoptosis protein (XIAP) suppresses apoptotic cell death by binding to caspases and inhibiting their functions, while the XIAP-associated factor1 (XAF1), a zinc finger protein, antagonizes XIAP activities, thereby promoting apoptosis. The aberrant silence of the XAF1 gene has recently been found in various types of cancer cells, which is suggested to be one of the potential mechanisms underlying survival advantages of malignant cells. In the present study, we investigated the XAF1 expression in prostate cancer cells. Compared with normal tissues where a full-length of XAF1 mRNA is predominant, LNCaP and DU145 prostate cancer cell lines only expressed a short form of XAF1 transcripts, whereas PC3 cells exhibited a complete silence of the XAF1 gene. Inhibition of DNA methylation led to a switch to the full length of XAF1 mRNA expression in LNCaP and DU145 cells. The down-regulation of XAF1 expression was also observed in 6/8 tumor samples derived from patients with prostate cancer. Our findings suggest that splicing alterations or downregulation of the XAF1 transcript may occur during the development of prostate cancers due to the aberrant DNA methylation. The alternative splicing of XAF1 mRNA leads to formation of a truncated XAF1 protein with 19 amino acid deletion in its zinc finger domain, which likely affects its functional interaction with XIAP, and consequently, contributes to the pathogenesis of prostate cancers by disrupting balance of the apoptosis machinery.

Adaptor Proteins, Signal Transducing↗

PubMed2006

Cytological features of prostatic intraepithelial neoplasia.

Fine-needle aspiration cytology (FNAC) is an acknowledged method for diagnosing prostate cancer. False-positive results are uncommon, but concerns have been raised that prostatic intraepithelial neoplasia (PIN) could be misinterpreted as carcinoma. Therefore, we attempted to describe cytological features of PIN. Cells were scraped from macroscopically normal areas of 177 radical prostatectomy specimens, smeared and Giemsa-stained. Histological slides from these areas were reviewed, and 17 samples with high-grade PIN and with no invasive cancer were selected. Smears from 17 invasive cancers were used for comparison. Cancer showed high cellularity and dissociation, while PIN smears only contained a few clusters of atypical cells. Pronounced nuclear atypia, prominent or multiple nucleoli and mucin were more common in cancer, while cytoplasmic granules, crystalloids and cluster size did not distinguish between PIN and cancer. In conclusion, PIN should not be diagnosed by FNAC alone. However, a highly cellular smear with pronounced atypia seems to preclude PIN.

Adenocarcinoma↗

PubMed2006

Evaluation of two sample preparation methods for prostate proteome analysis.

For laboratory techniques that require well-preserved proteins, such as 2-DE, fresh tissue must be harvested and processed as fast as possible to avoid proteolytic degradation. We describe a modified method for harvesting tissue from radical prostatectomy specimens for proteome analysis and compare it with the standard technique. Cells were scraped from cut surfaces of 11 prostate specimens. A fraction of the material was smeared on a glass slide and Giemsa stained for morphological control. The sample was collected in a medium with protease inhibitors, and the protein material was prepared for 2-DE. Filtering and Percoll centrifugation were omitted. Sample locations were noted on a specimen map. From the same area, a tissue block was harvested for comparison. The block was processed with the conventional technique including mechanical disintegration, filtering and Percoll centrifugation. Quality measures of 2-DE were similar with both methods. With the scrape sampling technique, control smears showed abundant epithelial cells and a cleaner background and processing was faster than with tissue block sampling. For proteomic analysis, the scrape sample technique has several advantages over the tissue block method.

Electrophoresis, Gel, Two-Dimensional↗

PubMed2006

Correlation of protein expression, Gleason score and DNA ploidy in prostate cancer.

The prognosis of prostate cancer correlates with tumor differentiation. Gleason score and DNA ploidy are two prognostic factors that correlate with prognosis. We analyzed differences in protein expression in prostate cancer of high and low aggressiveness according to these measures. From 35 prostatectomy specimens, 29 cancer samples and 10 benign samples were harvested by scraping cells from cut surfaces. DNA ploidy was assessed by image cytometry. Protein preparations from cell suspensions were examined by 2-DE. Protein spots that differed quantitatively between sample groups were identified by MS fingerprinting of tryptic fragments and MS/MS sequence analysis. We found 39 protein spots with expression levels that were raised or lowered in correlation with Gleason score and/or DNA ploidy pattern (31 overexpressed in high-malignant cancer, 8 underexpressed). Of these, 30 were identified by MS. Among overexpressed proteins were heat-shock, structural and membrane proteins and enzymes involved in gene silencing, protein synthesis/degradation, mitochondrial protein import (metaxin 2), detoxification (GST-pi) and energy metabolism. Stroma-associated proteins were generally underexpressed. The protein expression of prostate cancer correlates with tumor differentiation. Potential prognostic markers may be found among proteins that are differentially expressed and the clinical value of these should be validated.

Aged↗

PubMed2006

Current practice of diagnosis and reporting of prostate cancer on needle biopsy among genitourinary pathologists.

As there is a lack of hard data in the literature about many of the issues relating to diagnosing and reporting prostate cancer, we sought to survey current practices. A questionnaire was sent to 93 genitourinary pathologists with a response rate of 69%. Almost all respondents (95%) used formalin as fixative for needle biopsies. Unstained intervening sections were retained by 47%. Three levels of needle biopsies were used routinely by 63%. For verification of a diagnosis of cancer, high-molecular-weight cytokeratin was still the most commonly used immunohistochemical marker (91%), followed by p63 (58%) and alpha-methylacyl-CoA-racemase (50%). Features considered pathognomonic for cancer were glomeruloid bodies (58%), collagenous micronodules (64%), circumferential perineural invasion (84%), and growth in fat (36%). With none of these present, 39% required a minimum of 2 to 10 glands (median, 3) to diagnose cancer, whereas the others had no lower limit. A Gleason score was always given to even minute cancer foci by 86% and typically a Gleason score 6 was assigned (77%). Perineural invasion was mentioned by 86%. The extent of cancer on needle biopsies was quantified by all respondents with number of involved cores (80%) being the most commonly used measure. Linear extent was estimated by almost all, either as a percentage (80%) or millimeters of cancer length (41%) or both (22%). Measuring cancer from end to end or subtracting intervening benign tissue were almost equally common. For those general pathologists who would like to be in the mainstream of most urological pathologists, our survey data provide a guideline on how to diagnose and report prostate cancer.

Biopsy, Needle↗

PubMed2006

Proteomic analysis of tumor establishment and growth in the B16-F10 mouse melanoma model.

The B16-F10 mouse model of melanoma is a widely used model to study many aspects of cancer biology and therapeutics in a solid tumor. Melanomas aggressively progress within a dynamic microenvironment containing in addition to tumor cells, stroma cells and components such as fibroblasts, immune cells, vascular cells, extracellular matrix (ECM) and extracellular molecules. The goal of this study was to elucidate the processes of tumor progression by identifying differentially expressed proteins in the tumor mass during specific stages of tumor growth. A comparative proteome analysis was performed on B16-F10 derived tumors in C57BL/6 mice at days 3, 5, 7, and 10. Statistical approaches were used to determine quantitative differential protein expression at each tumor time stage. Hierarchical clustering of 44 protein spots (p < 0.01) revealed a progressive change in the tumor mass when all 4 time stages were classified together, but there was a clear switch in expression of these proteins between the day 5 and the day 7 tumors. A trend analysis showed 53 protein spots (p < 0.001) following 6 predominant kinetic paths of expression as the tumor progressed. The protein spots were then identified using MALDI-TOF mass spectrometry. Proteins involved in glycolysis, inflammation, wounding, superoxide metabolism, and chemotaxis increased during tumorigenesis. From day 3 to day 7 VEGF and active cathepsin D were induced 7-fold and 4-fold, respectively. Proteins involved in electron transport, protein folding, blood coagulation, and transport decreased during tumorigenesis. This work illustrates changes in the biology of the B16-F10 tumor mass during tumor progression.

Animals↗

PubMed2006

Current practice of diagnosis and reporting of prostatic intraepithelial neoplasia and glandular atypia among genitourinary pathologists.

The criteria for diagnosing prostatic intraepithelial neoplasia (PIN) and lesions suspicious for cancer are described in the literature. However, it is unknown how these are applied in practice by experts in genitourinary (GU) pathology. A questionnaire was sent to 93 GU pathologists in countries around the world with the purpose of surveying current practices. The response rate was 69% including 40 North American pathologists and 24 from other continents. For preneoplastic lesions, the term PIN was universally endorsed by the respondents. PIN was graded by 83%, usually as low/high-grade PIN (LGPIN/HGPIN) or as HGPIN only. Most respondents would usually not report lesions that may qualify for LGPIN. A majority (81%) did not specify architectural patterns of PIN. With both HGPIN and invasive cancer present, 69% would still mention HGPIN. Among the diagnostic criteria for HGPIN were any nucleoli visible (52%), or nucleoli seen in at least 10% of cells (33%). However, 56% would diagnose HGPIN in the absence of prominent nucleoli, most commonly based on prominent pleomorphism, marked hyperchromasia or mitotic figures. The number of cores involved with HGPIN was specified by 50%. Lesions suspicious for but not diagnostic of carcinoma were reported by 45% as atypia, atypical glands or suspicious for cancer and by 42% as atypical small acinar proliferation. The degree of suspicion was further defined by 41%. Our survey data may serve as a guideline to general pathologists on how to diagnose and report atypia and PIN in prostate biopsies.

Adult↗

PubMed2006

Prediction of percent Gleason grade 4/5 by multiple core biopsies.

OBJECTIVE: To evaluate whether percent Gleason grade 4/5 (i.e. the proportion of a tumor occupied by high-grade cancer) can be predicted by multiple needle biopsies. MATERIAL AND METHODS: In 115 men, 8-14 (mean 10) biopsies were taken, including eight from standardized positions (apex, mid-medial, mid-lateral and base). Biopsies were reviewed and cancer lengths measured. All men underwent radical prostatectomy. The prostatectomy specimens were totally embedded and tumor volume measured planimetrically. Gleason scores and percent Gleason grade 4/5 were assessed for both biopsy and prostatectomy specimens. RESULTS: Percent Gleason grade 4/5 in prostatectomy specimens was predicted correctly in 34% of cases and within 10%, 20% and 30% in 55%, 64% and 73% of cases, respectively. Biopsies had a sensitivity, specificity and accuracy for Gleason grade 4/5 of 62%, 87% and 69%, respectively. Positive and negative predictive values were 93% and 45%, respectively. The weighted kappa value for agreement was slightly higher for Gleason score (0.685) than for percent Gleason grade 4/5 (0.573). The univariate correlation for percent Gleason grade 4/5 in biopsies and the main tumor was r=0.62, r(2)=0.39 (p<0.001). In univariate logistic regression, percent Gleason grade 4/5 on biopsies predicted the presence of any Gleason grade 4/5 cancer in the main tumor (p=0.009). CONCLUSIONS: Gleason grade 4/5 in prostatectomy specimens correlates with findings in preoperative biopsies. Whether this measure will be used in routine practice remains to be seen.

Biopsy, Needle↗

PubMed2006

A working group classification of focal prostate atrophy lesions.

Focal atrophy is extremely common in prostate specimens. Although there are distinct histologic variants, the terminology is currently nonstandardized and no formal classification has been tested for interobserver reliability. This lack of standardization hampers the ability to study the biologic and clinical significance of these lesions. After informal and formal meetings by a number of the authors, focal atrophy lesions were categorized into 4 distinct subtypes as follows: (i) simple atrophy, (ii) simple atrophy with cyst formation, (iii) postatrophic hyperplasia, and (iv) partial atrophy. In phase 1 of the study, pathologists with varying levels of experience in prostate pathology were invited to view via the Internet a set of "training" images with associated descriptions of lesions considered typical of each subtype. In phase 2 of the study, each participant provided diagnoses on a series of 140 distinct "test" images that were viewed over the Internet. These test images consisted of the 4 subtypes of atrophy and images of normal epithelium, high grade prostatic intraepithelial neoplasia, and carcinoma. The diagnoses for each image from each pathologist were compared with a set of "standard" diagnoses and the kappa statistic was computed. Thirty-four pathologists completed both phases of the study. The interobserver reliability (median kappa) for classification of lesions as normal, cancer, prostatic intraepithelial neoplasia, or focal atrophy was 0.97. The median kappa for the classification of atrophy lesions into the 4 subtypes was 0.80. The median percent agreement with the standard diagnosis for the atrophy subtypes were: simple 60.6%, simple with cyst formation 100%; postatrophic hyperplasia 87.5%; partial atrophy 93.9%. The lower percentage for simple atrophy reflected a propensity to diagnose some of these as simple atrophy with cyst formation. Seven pathologists completed the phase 2 analysis a second time, and their intraobserver reproducibility was excellent. Three of 4 pathologists with low agreement with the standard diagnosis for simple atrophy improved their scores after repeating the analysis after re-examination of the "training set" of images. In conclusion, these criteria for variants of focal prostate atrophy may facilitate studies to examine the relation between various patterns of prostate atrophy and prostate cancer.

Atrophy↗

PubMed2005

Presence and specificity of tumor associated lymphocytes from ascites fluid in prostate cancer.

BACKGROUND: In the present study, we had the rare opportunity to study immunological responses of TAL from ascites fluid in a patient with hormone-refractory prostate cancer. METHODS: We evaluated tumor antigen-specific T-cell responses, induced by either prostate specific antigen (PSA) pulsed dendritic cells (DCs) or PSA peptides, in TAL and peripheral blood lymphocytes. RESULTS: DC stimulation with PSA protein induced recognition of naturally processed PSA epitopes by both blood and ascites T cells. In contrast, only ascites T cells recognized the PSA-3 peptide, after stimulation with PSA-pulsed DCs or peptides. Finally, although IFNgamma secreting T cells were detectable in both blood and ascites by ELISPOT, multiplex cytokine assay detected the presence of predominantly Th2 cytokines. CONCLUSIONS: Although tumor antigen-specific TAL were detected in ascites fluid, these cells were producing immunosuppressive cytokines which may contribute to tumor escape from recognition and/or destruction by the immune system.

Ascitic Fluid↗

PubMed2005

Ezrin expression in prostate cancer and benign prostatic tissue.

BACKGROUND: The membrane-linking protein ezrin is highly expressed in several types of human cancers and correlations between its immunoreactivity and histopathological data as well as patient outcome have previously been shown. However, such studies have not yet been done on human prostate cancer. This study assesses ezrin protein expression in a series of clinical specimens. METHODS: Immunohistochemical analysis was used to characterize patterns of ezrin expression in prostatic carcinoma and benign epithelium in 103 radical prostatectomy specimens. Ezrin immunoreactivity (IR) was scored 0 to 3 (absent, weak, moderate or strong staining). Agreement between three independent observers was calculated. RESULTS: Ezrin IR in prostate cancers was moderate or strong in 70% of specimens while negative or only weakly positive in benign epithelium. Interobserver agreement of IR score was substantial (mean weighted kappa 0.70, range 0.67-0.73). Ezrin expression correlated with Gleason score (p=0.016) and seminal vesicle invasion (p=0.006) but not with extraprostatic extension or margin status. No correlation with biochemical recurrence after prostatectomy was found (p=0.19). Urothelial and squamous metaplasia invariably showed moderate or strong ezrin expression. Epithelium of seminal vesicles and ejaculatory ducts was always intensely positive. CONCLUSION: Ezrin was expressed in the majority of prostate cancers and correlated with adverse prognostic factors. Interestingly, high levels of ezrin IR were observed in benign metaplastic epithelium and in seminal vesicles.

Aged↗

PubMed2005

Angiopoietin 2 expression is related to histological grade, vascular density, metastases, and outcome in prostate cancer.

BACKGROUND: In several malignant tissues, the angiopoietins are principal regulators of vascular growth and regression, but in normal prostate and prostate tumors the role of the angiopoietins is unknown. METHODS: Angiopoietin (ang) 1 and 2 were immunolocalized in TUR-diagnosed prostate tumors with long follow-up and the expression was related to vascular density and clinicopathological variables. RESULTS: Ang 1 was strongly expressed in the basal epithelial cell layer in non-malignant tissue, whereas tumors had lower levels localized to the epithelial cells. A weak ang 2 immunoreaction was observed in non-malignant tissue and in low to intermediate Gleason score (GS) tumors, with a similar expression pattern. However, most high GS tumors showed an intense ang 2 staining. Ang 2 was significantly correlated to GS, density of endoglin stained blood vessels, metastases, and to cancer specific survival. CONCLUSIONS: We conclude that ang 2 probably is an important regulator of angiogenesis in prostate cancer.

Aged↗

PubMed2005

Induction of PSA-specific CTLs and anti-tumor immunity by a genetic prostate cancer vaccine.

BACKGROUND: Prostate cancer is the most common malignancy in Swedish and American men. Effective curative treatment modalities are debilitating and available only for localized disease. As an immunotherapy approach, DNA encoding prostate-specific antigen (PSA), was used to immunize mice and induce PSA-specific cellular immunity. METHODS: A plasmid expressing PSA, alone or in combination with plasmids coding for GM-CSF and/or IL-2, was used for DNA immunization. Cr-release, intracellular IFN-gamma cytokine staining, and tumor challenge assays were used to evaluate the immune response. RESULTS: The DNA vaccine induces PSA-specific cytotoxic T lymphocytes (CTLs) and when co-injected with IL-2 and GM-CSF it protects four of five mice against a PSA-expressing tumor challenge. CONCLUSIONS: We demonstrate that immunization with a PSA DNA vaccine can evoke PSA-specific cellular immune responses. We also show, for the first time, that a PSA DNA vaccine can induce anti-tumor immunity in vivo.

Adjuvants, Immunologic↗

PubMed2005

Differential protein expression in anatomical zones of the prostate.

The prostate has three anatomical zones: the peripheral (PZ), the transition (TZ), and the central (CZ) zone. It is proposed that the CZ may be of mesodermal origin, whereas the other two are of endodermal origin. Proteome patterns in the zones were characterized to test for differences. Cells were scraped from macroscopically normal areas of PZ, TZ, and CZ in radical prostatectomy specimens. After exclusion of samples with cancer or prostatic intraepithelial neoplasia, 18 cases remained for analysis. Cells were collected in a medium with protease inhibitors, and the protein material was prepared for two-dimensional gel electrophoresis. The proteins in spots that differed quantitatively between regions were identified via mass spectrometric fingerprinting of tryptic fragments and selected tandem mass spectrometry sequence analysis. Ten proteins with significant zonal differential expression were identified, eight with underexpression in the CZ versus the PZ and the TZ (arginase II, ATP synthase, cytokeratin 8, lamin A/C, peroxiredoxin 4, protein disulfide isomerase A3, tropomyosin, and vimentin), and two with overexpression in the CZ (peroxiredoxin 2 and creatine kinase B). The PZ and TZ, although differing in terms of incidence of cancer and hyperplasia, have epithelium with highly similar major protein expression profiles. However, the protein profile of the CZ differs from that of the other regions, suggesting functional differences.

Aged↗