Immunohistochemical and molecular characterizations in urothelial carcinoma of bladder in patients less than 45 years.

Bladder tumours in early-onset patients are rare and seem to exhibit unique clinicopathological features. Only few studies have investigated somatic alterations in this specific age of onset group and evidence is accumulating of a distinct molecular behaviour of early-onset bladder tumours. We collected the largest cohort of early-onset tumours of patients 45 years old or younger and aimed to test genomic alterations typically found in bladder cancer. Tumours of 118 early-onset patients were compared with a consecutive group of 113 cases. Immunohistochemistry of TP53, CK20 and Ki-67 was carried out. Molecular analysis was conducted to test for loss of heterozygosity of chromosome 9 and 17, as well as TP53 and FGFR3 mutations. Fisher´s exact and chi-squared test were appropriately used. No differences in grade/stage characteristics were observed. Overexpressed TP53 was differentially distributed between the two groups. TP53 nuclear accumulation was significantly more frequent in early-onset papillomas, PUNLMPs and pTa low-grade tumours compared to the consecutive cohort (p=0.005). Moreover, chromosome 9 deletions (29.5% vs. 44.6%) and FGFR3 mutations (34.5% vs. 63.7%) were less often detected in early-onset patients (p=0.05 and p<0.0001). By comparing the largest cohort of early-onset bladder cancer patients with an unselected group, we demonstrated that the typical molecular features are not independent of age at diagnosis. Our study supports the hypothesis of a distinct biological behaviour in early-onset tumours.

Positive fibroblast growth factor receptor 3 immunoreactivity is associated with low-grade non-invasive urothelial bladder cancer.

In addition to conventional clinicopathological parameters, molecular markers are also required in order to predict the course of disease in patients with urothelial bladder cancer (BC). Little is known about fibroblast growth factor receptor 3 (FGFR3) immunoreactivity and the clinical significance it may possess with regard to BC. The present study aimed to investigate the immunoreactivity of FGFR3 in primary urothelial bladder tumours, with regard to clinicopathological features and FGFR3 mutation status. Tissue microarrays were used to immunohistochemically analyse FGFR3 expression in 255 primary, unselected patients with BC. FGFR3 mutations were detected using SNaPshot analysis. Positive FGFR3 immunoreactivity was identified in 113/207 analysable cases (54.6%), and was significantly associated with FGFR3 mutation (P<0.001), low tumour stage (P<0.001), low histological grade (P<0.001) and a papillary growth pattern (P<0.001). Positive FGFR3 immunostaining (P=0.002) and FGFR3 mutation (P=0.002) were found to be significantly associated with increased disease-specific survival following univariate analysis, demonstrating a median follow-up period of 75 months. Using multivariate analyses, FGFR3 immunoreactivity was found not to be independent of classical pathological parameters. Immunohistochemical expression of FGFR3 is an early occurrence during the carcinogenesis of papillary non-invasive BC. The presence of FGFR3 immunoreactivity in non-invasive papillary urothelial carcinomas may be utilised as an indicator of tumours possessing low-grade features and good prognosis.

Low frequency of HNPCC-associated microsatellite instability and aberrant MMR protein expression in early-onset bladder cancer.

OBJECTIVES: Recently, it was shown that patients with Lynch syndrome due to an MSH2 mutation are at increased risk for the development of bladder cancer. To further this discussion, we screened the largest investigated cohort of patients with early-onset bladder cancer for microsatellite instability (MSI) and mismatch repair (MMR) deficiency to determine a possible role of Lynch syndrome in young patients with bladder cancer. METHODS: A total of 109 cases of bladder tumors from young patients (aged <45 years) were examined for MSI (Bethesda consensus panel). Expression of MMR proteins (hMLH1, hMSH2, and hMSH6) was evaluated by immunohistochemistry using a tissue microarray. Results were compared with a series of unselected consecutive bladder tumors (n = 95). RESULTS: Regarding the frequency of MSI high (1% vs 0%) or abnormal expression of MMR proteins (2% vs 6.5%), no significant difference between the early-onset and unselected patient group was found. CONCLUSIONS: In young patients with bladder tumors, MSI and defects in MMR protein expression were not more frequent than in a series of consecutive bladder tumors. Most bladder tumors in young patients are not to be attributed to Lynch syndrome.

Immunologic and metabolic characteristics of HPV-negative and HPV-positive head and neck squamous cell carcinomas are strikingly different.

An HPV infection is involved in the etiology of about 25 % of head and neck squamous cell carcinomas (HNSCC). It has been postulated that a strong antitumoral immune response in HPV-positive tumors represents an important underlying mechanism for their good response to therapy. Recently, the Warburg phenomenon has returned to the center of attention because it affects antitumoral immune response and response to therapy. Accumulation of tumor cell-derived lactate inhibits cytotoxic T cells, as these, analogous to cancer cells, depend on glycolysis and lactate secretion for fulfillment of energy needs. Sparse information exists on the Warburg effect in HNSCC. This study aimed to characterize the metabolic and immunological features of HPV-negative and HPV-positive HNSCC. An immunohistochemical analysis of oropharyngeal carcinomas showed an enhanced antitumoral immune response (CD8/CD4 ratio) together with increased levels of proteins involved in transmembranous metabolite transportation (GLUT1 and CD147) and respiratory metabolism (COX5B) in HPV-positive tumors as compared to HPV-negative tumors. mRNA and Western blot analyses of an HPV-positive and HPV-negative HNSCC cell line revealed metabolic characteristics similar to the in vivo situation. Additionally, the HPV-negative cell line showed stronger extracellular lactate accumulation. In contrast, the HPV-positive cell line presented with better adaption to lactic acidosis suggesting an ability to metabolize lactate. Our results indicate that HPV-positive and HPV-negative carcinomas do not only differ in terms of tumor immune microenvironment, but also in terms of tumor metabolism, characterized by an increased glucose and respiratory metabolism together with decreased lactate accumulation in HPV-positive HNSCC. Therefore, targeting metabolic pathways could represent a promising adjunct in the therapy of HPV-positive HNSCC.

Comparison of HPV prevalence in HNSCC patients with regard to regional and socioeconomic factors.

HPV infection is considered as an independent risk factor for head and neck squamous cell carcinomas (HNSCC). Due to highly variable prevalence results in numerous studies, it is, however, difficult to estimate the relevance of HPV infection as risk factor for a specific patient collective. This study aimed to elucidate the disparities of HPV prevalence by analyzing socioeconomically and regionally different patient collectives. Two age, gender, stage and tumor location matched cohorts of 18 private health insured (PHIP) and 16 statutory health insured patients (SIP) suffering from an oropharyngeal squamous cell carcinoma (OSCC) and treated at a university hospital were screened for p16 overexpression and HPV infection by immunohistochemistry and PCR. In addition 85 HNSCC patients of an otolaryngology private practice (PPP) in a rural area were screened for p16 overexpression and positive cases were tested for HPV infection. HPV prevalence was 72.2% in the PHIP collective in comparison to 25.0% (p = 0.015) in the SIP collective with a significantly improved 5-year overall survival (p = 0.003) of the PHIP collective. The total HPV prevalence of PPP group was 7.1% with the highest infection rate in tonsillar carcinomas (33.3%) and a larger percentage of female patients in the HPV positive group (p = 0.037). This study shows that variable HPV infection rates in HNSCC can be caused by the selection of particular patient collectives, which suggest taking socioeconomic and regional factors into account for a decision on HPV testing, if it is not performed on a routine basis.

Male infertility: assessment of juvenile testicular dysfunction and risk for malignancy in cryptorchid boys based on resin section evaluation.

Infertility is sometimes more a man's problem than a woman's, failure of one or both of the testes to descend (cryptorchidism) being the most frequent genital malformation in boys. Untreated, the undescended testis impairs germ cell development and significantly reduces adult fertility. A-dark spermatogonia are the stem cells for all future spermatozoa, and their depletion can be reliably estimated in resin semithin sections. Additionally, there is an increased risk of testicular preneoplasia in the form of carcinoma in situ (CIS) cells. The authors report how the pathologic biopsy examination of juvenile cryptorchid testes can assess infertility and malignancy risk.

Persistent histological changes in the exstrophic bladder after primary closure-a cause for concern?

PURPOSE: We investigated bladder biopsies from patients with classic bladder exstrophy for the histological features and discuss the potential clinical significance of the findings. MATERIALS AND METHODS: Bladder tissues were collected from patients with bladder exstrophy between 2004 and 2011. These specimens were obtained at primary bladder closure (group 1, 29 patients), during secondary reconstructive procedures (group 2, 27) or during cystectomy for failed reconstruction (group 3, 15). All tissue specimens were investigated for inflammatory, proliferative, metaplastic and dysplastic changes. Expression of urothelial differentiation markers CK13 and CK20 was determined by immunohistochemical analysis. RESULTS: Inflammatory, proliferative and metaplastic changes were found in bladder specimens of all subgroups. Neither dysplasia nor neoplasia was present. Severe epithelial changes such as cystitis glandularis and intestinal metaplasia were observed in up to 62% of bladders several years after primary closure. Aberrant expression patterns of CK13 and CK20 suggesting abnormal urothelial differentiation were shown to be present in the urothelium of all subgroups. CONCLUSIONS: Our findings provide prima facie evidence that the epithelial changes observed in the unclosed bladder template persist or even progress in a subset of bladders after primary closure. Although the malignant potential of cystitis glandularis and intestinal metaplasia is controversial, some patients may be at increased risk for dysplasia/neoplasia in the long term. Since the natural history of these lesions in the exstrophic bladder is unknown, these patients require lifelong surveillance.

NAD(P)H:quinone oxidoreductase 1 (NQO1) P187S polymorphism and prostate cancer risk in Caucasians.

NAD(P)H:quinone oxidoreductase 1 (NQO1) catalyses the reduction of quinoid compounds to hydroquinones, preventing the generation of free radicals and reactive oxygen. A "C" to "T" transversion at position 609 of NQO1, leading to a nonsynonymous amino acid change (Pro187Ser, P187S), results in an altered enzyme activity. No NQO1 protein activity was detected in NQO1(609)TT genotype, and low to intermediate activity was detected in NQO1(609)CT genotype compared with (609)CC genotype. Thus, this polymorphism may result in altered cancer predisposition. For prostate cancer, only sparse data are available. We therefore analyzed the distribution of the NQO1 P187S SNP (single nucleotide polymorphism) in prostate cancer patients and a healthy control group. Allelic variants were determined using RFLP analysis. Overall, 232 patients without any malignancy and 119 consecutive prostate cancer patients were investigated. The genotype distribution in our cohorts followed the Hardy-Weinberg equilibrium in cases and controls. The distribution of the NQO1 codon 187 SNP did not differ significantly between prostate cancer patients and the control group (p = 0.242). There was also no association between the allelic variants and stage or Gleason score of the tumors. The NQO1 P187S SNP was not significantly associated with an increased prostate cancer risk in our cohorts. The SNP has also no influence on histopathological characteristics of the tumors. A combined analysis of all available data from published European studies also showed no significant differences in the genotype distribution between controls and prostate cancer patients. Our data suggest a minor role of the NQO1 nucleotide 609 polymorphism in prostate carcinogenesis.

Expression and potential clinical significance of urothelial cytodifferentiation markers in the exstrophic bladder.

PURPOSE: We characterize the urothelium from patients with classic bladder exstrophy-epispadias complex for the expression of proteins associated with urothelial differentiation, and discuss a potential impact of urothelial phenotype on the structural and functional properties of the bladder template following bladder closure. MATERIALS AND METHODS: From 2005 to 2010 bladder biopsies from 32 infants with bladder exstrophy-epispadias complex obtained at primary bladder closure were collected. After histological assessment immunochemistry was used to investigate the expression of uroplakin IIIa, cytokeratin differentiation restricted antigens CK13 and CK20, and tight junction protein claudin 4. RESULTS: Overall tissue morphology showed gross alterations with inflammatory, proliferative and metaplastic changes in most specimens. Sections of intact epithelium were present in 78% of biopsies. With respect to urothelial phenotype, CK13 was expressed in all specimens, whereas UPIIIa and CK20 were absent in 76% of the tissues examined. Of the biopsies 52% revealed an irregular expression pattern of tight junction protein Cl-4. CONCLUSIONS: This is the first study to our knowledge to characterize the urothelium from infants with bladder exstrophy-epispadias complex for the expression of urothelial differentiation associated antigens. Our findings suggest urothelial differentiation changes in a majority of exstrophic bladders, at least at primary bladder closure. Although the underlying etiology remains to be established, abnormal urothelial differentiation may result in a dysfunctional urothelial barrier with implications for the structural and functional properties of the bladder template. Despite the study limitations, our preliminary findings provide a platform for further investigation of the significance of the urothelium for the exstrophic bladder.

Mismatch repair proteins hMLH1 and hMSH2 are differently expressed in the three main subtypes of sporadic renal cell carcinoma.

OBJECTIVES: We studied the role of minor mismatch repair proteins (MMR) human MutL homologue 1 (hMLH1) and human MutS homologue 2 (hMSH2) in the main subtypes of renal cell carcinoma (RCC). METHODS: Expression of MMR proteins hMLH1 and hMSH2 were investigated in 166 RCC tumors, containing the main subtypes by immunohistochemistry. Furthermore, each tumor was screened for microsatellite instability (MSI) using the National Cancer Institute consensus panel for hereditary non-polyposis colon carcinoma as well as for elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) by 10 additional markers. RESULTS: MSI was found only in 2.0% of analyzable cases and EMAST was detected only in 1 patient. hMLH1 and hMSH2 expression was reduced in 83.7 (118/141) and 51.2% (65/127) of cases, respectively, in a subtype-specific manner. None of the clear cell RCC tumors retained a high hMLH1 expression and 92.0% lost hMLH1 completely, while papillary and chromophobe RCC preserved the expression in 25.0 and 33.3% of cases (p < 0.001). Subtype specificity was also present in hMSH2 staining, where chromophobe RCC retained a high expression in 41.7% of cases, while clear cell and papillary tumors did not (29.9 and 23.1%; p = 0.01). CONCLUSION: MSI and EMAST are rare events in sporadic RCC, whereas diminished MMR protein expression is linked to tumor entity and might contribute to the different biological behavior of the RCC subtypes.

Substaging by estimating the size of invasive tumour can improve risk stratification in pT1 urothelial bladder cancer-evaluation of a large hospital-based single-centre series.

AIMS: The outcome of patients with pT1 bladder cancer cannot yet be reliably estimated. The aim of this study was to evaluate several parameters in one of the largest series of initial pT1 bladder cancers. METHODS AND RESULTS: Specimens of 309 patients with pT1 urothelial carcinoma were re-evaluated histologically, including size of infiltrating tumour area estimated as equal to or smaller than one high-power field (HPF) or larger than one HPF, and tumour infiltration in relation to the muscularis mucosae (pT1a/b). Results were correlated with clinical follow-up. Substaging by HPF was associated with tumour recurrence, progression and survival in univariate analysis, and with recurrence and progression in multivariate analysis. According to the World Health Organization (WHO) 1973 grading, 220 tumours were G3, 89 were G2, and none was G1. Tumour grading was an independent prognostic marker of survival. Substaging by HPF revealed G2 and G3 tumours as distinct prognostic groups with regard to recurrence and progression. No significance was found for substaging pT1a/pT1b. An infiltrative growth pattern was significantly correlated with progression and survival in univariate analysis. CONCLUSIONS: Comparison of two systems of substaging pT1 bladder cancer shows that measurement of the size of infiltrating tumour area by HPFs may improve risk stratification. An infiltrative growth pattern on the invasion front should be documented in the pathological report, indicating a worse outcome. Additional studies are needed to find further parameters detecting high-risk tumours.

P53 codon 72 (Arg72Pro) polymorphism and prostate cancer risk: association between disease onset and proline genotype.

The tumor suppressor gene p53 plays an important role in the stress response of the cell and is mutated in 50% of all human tumors. The p53 Arg72Pro single-nucleotide polymorphism (SNP) was found to be associated with an increased risk of various malignancies. Biochemical and biological differences between the 2 polymorphic variants of wild-type P53 might lead to distinct susceptibility to HPV- and non-HPV-induced tumors. For prostate cancer, only limited data are available, especially in the Caucasian population. Therefore, we determined the distribution of the Arg72Pro SNP in a Caucasian case-control study including 118 prostate cancer patients and 194 male controls without any malignancy using restriction fragment length polymorphism analysis. A subset of 33 tumors was tested for HPV infection, and no HPV DNA was found. Cases and controls showed similar distributions of alleles in the SNP (p = 0.720). Regarding the onset of the disease, patients diagnosed at ≤60 years of age and older patients (>60 years of age) showed a significant difference in genotype distribution (p = 0.035); there was also an increased occurrence of risk allele Pro72 in cases aged ≤60 years (p = 0.045). A subset of 64 prostate tumors was stained immunohistochemically for P53. 5 of 64 prostate tumors (7.8%) were positive for P53 expression, indicating integrity of the protein in the majority of cases. Genotype distribution showed no association with the Gleason score or additional histopathological characteristics. This study shows that the overall risk of prostate cancer was not associated with Arg72Pro SNP and HPV infection in our cohort. However, disease onset might be modulated by the p53 Pro72 allele, suggesting an important role of apoptosis regulation in prostate carcinogenesis.

Patients with localised prostate cancer (t1 - t2) show improved overall long-term survival compared to the normal population.

BACKGROUND: Little information is available on the long-term outcomes of patients with localised prostate cancer. OBJECTIVE: To examine the long-term survival of patients with localised prostate gland carcinoma T1 - T2, N0, M0 (UICC stage I and II) compared to the normal population. DESIGN: Retrospective cohort. SETTING: Regensburg, Germany. PARTICIPANTS: Data on 2121 patients with histologically-confirmed, localised prostate cancer diagnosed between 1998 and 2007 were extracted from the cancer registry of the tumour centre in Regensburg, Germany. MEASUREMENTS: Overall survival rate in the patient cohort was estimated and compared to the expected survival rate of a comparable group in the general population derived from the official life-tables of Germany stratified by age, sex and calendar year. RESULTS: Ten years after diagnosis, patients with stage I and II localised prostate gland carcinoma had an approximately 10% increase in survival compared to the normal male population (Relative Survival = 110.7%, 95%-CI 106.6 - 114.8%). LIMITATIONS: We did not examine the effect of cancer treatment or cancer aggressiveness on the overall survival of patients. We did not assess the incidence of subsequent non-primary cancers in our patient population or how this incidence affects the patients' follow-up care and survival. CONCLUSIONS: Patients with stage I+II localised prostate gland carcinoma have improved survival compared with the normal male population. This finding cannot be explained solely by the administration of prostate carcinoma treatments, suggesting that men who participate in PSA screening may have better overall health behaviors and care than men who do not participate in screening. Future research should examine how treatment choice, especially an "active surveillance" approach to care, affects survival in these patients more than ten years after diagnosis.

The plasmacytoid carcinoma of the bladder--rare variant of aggressive urothelial carcinoma.

The WHO 2004 classification defines new histological and molecular variants of urothelial carcinoma. However, there are limited data available on the clinicopathological characteristics or prognosis of these variants. We present histopathological, molecular and clinical data of 32 plasmacytoid carcinomas of the bladder (PUC) showing that PUC is a high-grade tumor with molecular features of aggressive urothelial carcinoma, usually diagnosed in advanced pathological stage (64% pT3, 23% pT4) showing metastases in 60% of the patients. Average survival of our cohort of PUC treated with radical cystectomy and adjuvant chemotherapy was lower than what is typically seen for comparable conventional urothelial carcinomas. Eighty-seven percent of the PUCs showed a negative or strongly reduced membranous staining of E-cadherin. ß-Catenin staining was negative in 22.5%, and 16.7% of the remaining tumors showed nuclear accumulation. Aberrant CK20 expression (negative or >10% of cells stained) and negative CK7 staining was found in 100% and 22.6%, respectively. Ninety-seven percent revealed positive staining for PAN-CK. CD138 was positive in 78%, whereas MUM-1 expression was negative in all cases. Multitarget fluorescence in situ hybridization showed all PUCs to be highly aneuploid and polysomic. Deletions on chromosome 9p21 seem to play an important role in this variant. FGFR3 and PIK3CA mutation analyses yielded no mutations in any of the PUCs analyzed. TP53 mutation analysis showed mutations in 29%. In summary, PUC is an aggressive variant of bladder cancer with molecular features of advanced bladder cancer and evidence of WNT pathway activation in some of the cases.

Importance of CCL2-CCR2A/2B signaling for monocyte migration into spheroids of breast cancer-derived fibroblasts.

A considerable fraction of tumor-associated macrophages (TAM) is located in the fibroblast-rich stromal compartment of desmoplastic breast carcinoma. We analyzed the migratory activity of blood monocytes (MO), the precursor cells of TAM, into 3-D cultures of carcinoma cells and fibroblasts from breast tumor origin. MO migration into breast tumor spheroids was highly variable: Hs578T spheroids showed high MO infiltration rates, T47D cultures were intermediate, whereas BT549, BT474 and MCF-7 spheroids were poorly infiltrated. MO infiltration was also high in tumor-derived fibroblast spheroids; however, no MO subpopulation with specific infiltrative potential was identified by CD14/CD16 expression profile. The infiltration of MO could be inhibited by pre-exposure to pertussis and cholera toxins, but only pertussis toxin, which blocks G(i) protein function, entirely inhibited MO migration. The G(i) coupled CCL2 receptor CCR2A/2B was expressed on roughly all MO. Furthermore, highly infiltrated tumor-derived fibroblast and Hs578T spheroids secreted considerable amounts of CCL2. In line with this, the infiltration of MO into fibroblast spheroids was suppressed by either addition of recombinant CCL2 to disturb the CCL2 gradient or by pre-incubation of MO with a CCR2A/2B blocking antibody. MO infiltration of Hs578T spheroids, however, could not be inhibited by CCL2 receptor blockade. Our study clearly shows that the CCL2-CCR2A/2B pathway is crucial for the recruitment of blood MO into tumor fibroblastic areas, whereas additional factors may be relevant for the migration of MO into tumor cell sites.

Methylthioadenosine phosphorylase represents a predictive marker for response to adjuvant interferon therapy in patients with malignant melanoma.

Using tissue microarrays assembling 465 nevi, primary melanomas and metastases, we investigated whether expression of methylthioadenosine phosphorylase (MTAP), a recently suggested biomarker of malignant melanoma, has prognostic significance and may predict responsiveness to adjuvant interferon therapy in patients with melanoma. Because of its association with MTAP activity and interferon signalling pathways, signal transducer and activator of transcription 1 (STAT1) immunohistochemistry was analysed, too. MTAP expression was significantly reduced in melanomas and metastases compared with nevi (P < 0.001); STAT1 expression significantly increased. In melanomas, loss of MTAP expression was significantly related to Clark level (P < 0.05) and tumor thickness (P < 0.01); whereas STAT1 immunoreactivity was significantly related to gender (p < 0.05) and tumor thickness (P < 0.05). Interestingly, subgroup analysis of patients with a tumor thickness of 1.5-4.0 mm revealed a significant survival benefit from adjuvant interferon treatment regarding recurrence-free survival (RFS; P < 0.05) if MTAP expression was observed in the primary melanoma. Patients with STAT1-positive melanomas also tended to benefit from interferon concerning RFS (P = 0.074) and showed a significant benefit concerning overall survival (OS; P < 0.05). According to Cox analysis, MTAP expression in contrast to STAT1 was an independent positive prognostic marker for RFS and OS. In conclusion, MTAP represents a highly promising immunohistochemical marker for prognosis and interferon response of patients with malignant melanoma.

Multichromatic phenotyping of HER receptor coexpression in breast tumor tissue samples using flow cytometry--possibilities and limitations.

The prognostic significance of HER2 expression in human breast carcinomas is beyond dispute nowadays. The HER family of receptor tyrosine kinases comprises four members (HER1/ErbB1/EGFR, HER2/ErbB2, HER3/ErbB3, and HER4/ErbB4) that act in concert via transactivation and consequently compose a functional signaling unit. Besides HER2 overexpression, coexpression of other HER receptors has substantial impact on course of disease and potential therapeutic benefit. This observation is substantiated by numerous preclinical studies and retrospective studies done on patients with breast cancer. Against this background, the quantification of all HER receptor expressions at the same time would significantly extend the information content revealed by routine diagnosis of breast cancer tissues. Moreover, the knowledge of HER receptor coexpression profiles in primary tumor samples could provide the basis to design and develop highly specific antireceptor treatment strategies. Here, we report on a simultaneous flow cytometric detection of all four HER receptors on carcinoma cells isolated from primary breast cancer tissues and separated from nonepithelial cells by cytokeratin staining. Combined with DNA, i.e. ploidy quantification, the approach resulted in a six-parameter assay that could complement the diagnosis of a variety of diseases in which HER receptor expression has a pivotal impact on the degree of malignancy.

Association of HLA class I antigen abnormalities with disease progression and early recurrence in prostate cancer.

Defects in HLA class I antigen processing machinery (APM) component expression often have a negative impact on the clinical course of tumors and on the response to T cell-based immunotherapy. Since only scant information is available about the frequency and clinical significance of HLA class I APM component abnormalities in prostate cancer, the APM component expression pattern was analyzed in 59 primary prostate carcinoma, adjacent normal tissues, as well as in prostate carcinoma cell lines. The IFN-gamma inducible proteasome subunits LMP2 and LMP7, TAP1, TAP2, calnexin, calreticulin, ERp57, and tapasin are strongly expressed in the cytoplasm of normal prostate cells, whereas HLA class I heavy chain (HC) and beta(2)-microglobulin are expressed on the cell surface. Most of the APM components were downregulated in a substantial number of prostate cancers. With the exception of HLA class I HC, TAP2 and ERp57 not detectable in about 0.5% of tumor lesions, all other APM components were not detected in at least 21% of lesions analyzed. These APM component defects were associated with a higher Gleason grade of tumors and an early disease recurrence. Prostate carcinoma cell lines also exhibit a heterogeneous, but reduced constitutive APM component expression pattern associated with lack or reduced HLA class I surface antigens, which could be upregulated by IFN-gamma. Our results suggest that HLA class I APM component abnormalities are mainly due to regulatory mechanisms, play a role in the clinical course of prostate cancer and on the outcome of T cell-based immunotherapies.

Presence of HER4 associates with increased sensitivity to Herceptin in patients with metastatic breast cancer.

INTRODUCTION: HER2 overexpression, or rather HER2 gene amplification, is indicative for Herceptin therapy in both metastatic and pre-metastatic breast cancer patients. Patient's individual sensitivity to Herceptin treatment, however, varies enormously and spans from effectual responsiveness over acquired insensitivity to complete resistance from the outset. Thus no predictive information can be deduced from HER2 determination so that molecular biomarkers indicative for Herceptin sensitivity or resistance need to be identified. Both ErbB receptor-dependent signalling molecules as well as HER2-related ErbB receptor tyrosine kinases, known to mutually interact and to cross-regulate each other are prime candidates to be involved in cellular susceptibility to Herceptin. METHODS: Using immunohistochemistry and fluorescence in situ hybridisation, we retrospectively investigated primary breast cancer tissues from 48 patients who were under Herceptin treatment. We quantified the gene copy numbers of all HER receptors and evaluated their coexpression profile. Moreover the HER2 phosphorylation state, the ratio of native to truncated HER2, p27(kip1) and PTEN expression were objects of this study. RESULTS: Above all markers investigated in this study Kaplan-Meier and Cox regression analysis revealed a significant positive impact of HER4 (co-)expression on overall survival from beginning of antibody therapy. Both HER4 expression and HER4 gene amplification emerged as independent prognostic markers in Herceptin-treated breast cancer patients and responsiveness to Herceptin turned out to be more efficient if tumour cells show HER4 expression. CONCLUSIONS: Although HER4 is known to potentially exert a tumour cell killing activity and in turn to have a favourable impact in breast cancer patients we demonstrate here the first time that HER4 expression prolongs overall survival in Herceptin-treated patients. Elucidating HER4 receptor function in the context of Herceptin treatment will advance the design of highly efficient receptor targeting. By then we need to extend the analysis of breast cancer by allowing for HER2/HER4 coexpression by which valuable additional prognostic and predictive information might possibly be revealed.