PubMed Health⌕ Search

Biomedical subjects

Axel Wellmann

Publications and source records attributed to Axel Wellmann.

12 recordsLinked to original sources
PubMed2006

Tumour-stroma interactions between metastatic prostate cancer cells and fibroblasts.

Previous work has shown the importance of tumour-stroma interactions for prostate cancer development at the primary site. The aim of the present study was to find out whether evidence can be found for a tumour-stroma cross- talk also between metastatic prostate cancer cell lines and non-prostatic stromal fibroblasts which are encountered by metastatic cells at most sites. We addressed this issue in cell culture systems using 3 metastatic human prostate cancer cell lines (LnCaP, PC-3 and DU-145) on the one hand, and a human fibroblast line (HFF, human foreskin fibroblasts) on the other. We incubated fibroblasts with tumour cell- and tumour cells with fibroblast-conditioned media and evaluated several parameters important for the establishment of metastases such as cell proliferation, migration and expression of matrix degrading proteases. We also determined in the conditioned media the concentrations of several growth factors and cytokines which might be responsible for the observed effects. We found that media conditioned by all 3 metastatic prostate cancer cell lines stimulated fibroblast proliferation which corresponds to fibrous stroma induction in vivo. DU-145 cell conditioned media induced in fibroblasts expression of mmp-1 mRNA known to be important for tumour invasion. ELISA assays revealed that tumour cells secrete bFGF, PDGF and TNFalpha known to stimulate fibroblast proliferation and/or MMP-1 expression. Cultivation of DU-145 carcinoma cells in fibroblast conditioned medium resulted in an enhanced proliferation and anchorage-independent growth of this cell line in soft agar. Fibroblast conditioned medium also increased migration of PC-3 cells in the wound assay and slightly augmented mmp-1 expression. KGF (able to stimulate proliferation of normal and neoplastic prostate epithelial cells) was secreted by fibroblasts at higher concentrations than by all 3 tumour cell lines. In addition, fibroblasts secreted TNFalpha, bFGF, PDGF, HGF and also VEGF, the most important factor for tumour vascularization. Our results provide evidence that tumour-stroma interactions do not only exist at the primary site but also between metastatic prostate cancer cell lines and their fibroblastic microenvironment. These interactions, which are mediated through secreted factors, affect several steps of the metastatic cascade including proliferation, anchorage-independent growth, migration and the secretion of matrix-degrading proteases.

Carcinoma↗
PubMed2005

Diagnostic and prognostic information in prostate cancer with the help of a small set of hypermethylated gene loci.

PURPOSE: Our study was designed to evaluate promoter CpG island hypermethylation in the diagnosis and prognosis of prostate cancer. EXPERIMENTAL DESIGN: Primary prostate cancers from 53 patients, pelvic lymph nodes, noncancerous prostate tissues, and prostate cell lines were analyzed. Real-time methylation-specific PCR was used to identify CpG island hypermethylation at five promising gene loci (i.e., GSTP1, APC, PTGS2, MDR1, and RASSF1a). RESULTS: At three gene loci (GSTP1, APC, and PTGS1) and CpG island, hypermethylation was highly prevalent in prostate cancers (71-91%), and analysis of receiver operator curves showed that hypermethylation at these three gene loci can distinguish between prostate cancer and noncancerous prostatic tissue (i.e., benign hyperplasia) with a sensitivity of 71.1% to 96.2% and a specificity of 92.9% to 100%. Using sensitive SYBR green methylation-specific PCR technology, we observed a respective 28% and 71% hypermethylation rate at the RASSF1a and MDR1 loci in benign prostate hyperplasia, which may represent early nonaggressive carcinogenesis. Methylation characteristics in prostate cancer metastases (i.e., pelvic lymph nodes) were comparable to the respective primary cancer. Statistical analysis showed no correlation between the methylation status of a single gene locus and clinicopathologic variables (e.g., preoperative prostate specific antigen levels, Gleason score, capsular penetration, involvement of seminal vesicle, and age). In contrast, the methylation of two (GSTP1/APC; GSTP1/PTGS2) or three (GSTP1/APC/PTGS2) gene loci correlated with prognostic indicators (i.e., pathologic stage, extraprostatic extension, and Gleason score, but not with prostate specific antigen levels). CONCLUSIONS: Our data suggest that the evaluation of DNA hypermethylation at three gene loci (i.e., GSTP1, APC, and PTGS2) is of diagnostic and prognostic value in prostate cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

A novel component of the ubiquitin pathway, ubiquitin carboxyl extension protein 1 is overexpressed in prostate cancer.

Prostate cancer is among the most common tumors in industrialized nations. However, little is known about the molecular events underlying its development. In the present study we used suppressive subtraction hybridization (SSH) in combination with laser-assisted microdissection in order to compare gene expression between prostate carcinoma and the normal prostate proper. Both are mixed tissues which consist of an epithelial and a stromal compartment. We first compared mRNA (cDNA) expression by SSH and then used real-time quantitative RT-PCR analysis of microdissected tissue probes in order to verify differential expression of subtracted cDNA clones. We also used differentially expressed cDNAs for the synthesis of radiolabelled riboprobes in order to attribute differential expression to specific cell types in tissue sections by in situ hybridization. Using this approach we found an up-regulation of ubiquitin carboxyl extension protein 1 (UBCEP-1) mRNA in prostate carcinoma cells compared to the normal glandular epithelium of the prostate proper. UBCEP-1 mediated ubiquitin chain elongation may promote prostate carcinoma development by increasing via the proteasome pathway the degradation of proteins which are involved in growth inhibition or apoptosis.

Aged↗
PubMed2005

Cellular retinoic acid-binding protein 2 is down-regulated in prostate cancer.

Prostate cancer is among the most frequent tumours in industrialized nations and many questions remain open concerning the molecular events underlying its development and progression. In the present study we have combined cDNA array hybridization to laser-assisted microdissection (LAM) in order to investigate differences in gene expression between epithelial and stromal cells of prostate cancer and normal peripheral prostate tissue. Results have been verified for selected candidate genes by quantitative real-time RT-PCR. Using this approach and immunohistochemistry we could demonstrate a down-regulation of cellular retinoic acid binding protein 2 (CRABP2) mRNA and protein in carcinoma cells compared to normal glandular cells. CRABP2 is a main regulator of anti-carcinogenic activities of retinoic acid and may become a novel diagnostic marker and experimental therapeutic tool for prostate cancer. In addition, results of cDNA array hybridization suggest an up-regulation of 34 further genes and a down-regulation of 6 genes in cancer tissues compared to normal peripheral prostate tissues. Several of these genes have already been reported to be associated with carcinogenesis in organs such as the prostate.

Aged↗
PubMed2004

PKN3 is required for malignant prostate cell growth downstream of activated PI 3-kinase.

Chronic activation of the phosphoinositide 3-kinase (PI3K)/PTEN signal transduction pathway contributes to metastatic cell growth, but up to now effectors mediating this response are poorly defined. By simulating chronic activation of PI3K signaling experimentally, combined with three-dimensional (3D) culture conditions and gene expression profiling, we aimed to identify novel effectors that contribute to malignant cell growth. Using this approach we identified and validated PKN3, a barely characterized protein kinase C-related molecule, as a novel effector mediating malignant cell growth downstream of activated PI3K. PKN3 is required for invasive prostate cell growth as assessed by 3D cell culture assays and in an orthotopic mouse tumor model by inducible expression of short hairpin RNA (shRNA). We demonstrate that PKN3 is regulated by PI3K at both the expression level and the catalytic activity level. Therefore, PKN3 might represent a preferred target for therapeutic intervention in cancers that lack tumor suppressor PTEN function or depend on chronic activation of PI3K.

Animals↗
PubMed2003

Stromal expression of invasion-promoting, matrix-degrading proteases MMP-1 and -9 and the Ets 1 transcription factor in HNPCC carcinomas and sporadic colorectal cancers.

Hereditary nonpolyposis colorectal cancers (HNPCCs) are an important subgroup of colorectal carcinomas. Compared to sporadic variants, they present several particular features, the most important of which are less invasive and metastatic properties linked to a more favorable prognosis. This contrasts to the generally poor differentiation of the epithelial tumor component. Since matrix-degrading proteases secreted by stromal fibroblasts contribute significantly to tumor invasion, we analyzed the stromal expression of 2 matrix metalloproteinases (MMP-1 and -9) and of one of their regulators, the Ets 1 transcription factor, by both immunohistochemistry and in situ hybridization in sporadic colorectal carcinomas and HNPCC tumors. We found that MMP-1 and -9 as well as Ets 1 are upregulated in the fibroblastic stroma during the development from sporadic adenomas to invasive carcinomas. HNPCC tumors exhibited a significantly lower expression of Ets 1, MMP-1 and -9. These findings on the basis of lower matrix-degrading properties of the fibroblastic tumor stroma in HNPCC tumors might help to explain why, in spite of their less differentiated phenotype, HNPCC tumors have a less invasive and metastatic potential compared to sporadic cancers.

Adenoma↗
PubMed2003

Long-term benzimidazole treatment of alveolar echinococcosis with hematogenic subcutaneous and bone dissemination.

We report a case of advanced alveolar echinococcosis (AE) that presented like a malignant tumor. It was diagnosed histologically from a subcutaneous nodule with skin inflammation on the right leg. Additionally, the patient showed bone metastases in the lower thoracic spine and the left third toe. This is the first case with proven hematogenic spread of AE to a subcutaneous site. The patient was treated with albendazole and remained stable for 6 years. When progression of AE occurred the therapy was changed to mebendazole, resulting in a stable condition for further 4 years.

Albendazole↗
PubMed2002

Analysis of microdissected prostate tissue with ProteinChip arrays--a way to new insights into carcinogenesis and to diagnostic tools.

Prostate carcinomas are one of the most common malignancies in western societies. The pathogenesis of this tumor is still poorly understood. These tumors present with two characteristic features: epithelial-mesenchymal interactions, which play a pivotal role for tumor development and most of clinically manifest cancers arise in prostate proper compared to a minority of tumors which develop in the transitional zone. Deciphering the epithelial-mesenchymal cross talk and identification of molecular pecularities of the sub-populations of cells in different zones can therefore help understanding carcinogenesis and development of new, non-invasive tools for the diagnosis and prognosis of prostate carcinomas which has remained a challenge until today. A ProteinChip array technology (SELDI = surface enhanced laser desorption ionization) has been developed recently by Ciphergen Biosystems enabling analysis and profiling of complex protein mixtures from a few cells. This study describes the analysis of approximately 500-1000 freshly obtained prostate cells by SELDI-TOF-MS (surface enhanced laser desorption ionization time-of-flight mass spectrometry). Pure cell populations of stroma, epithelium and tumor cells were selected by laser assisted microdissection. Multiple specific protein patterns were reproducibly detected in the range from 1.5 to 30 kDa in 28 sub-populations of 4 tumorous prostates and 1 control. A specific 4.3 kDa peak was increased in the prostate tumor stroma compared to normal prostate proper and transitional zone stroma and increased in prostate tumor glands compared to normal prostate proper and transitional zone glands. Coupling laser assisted microdissection with SELDI provides tremendous opportunities to identify cell and tumor specific proteins to understand molecular events underlying prostate carcinoma development. It underlines the vast potential of this technology to better understand pathogenesis and identify potential candidates for new specific biomarkers in general which could help to screen for and distinguish disease entities, i.e. between clinically significant and insignificant carcinomas of the prostate.

Aged↗
PubMedDate not supplied

Economical data and advanced prostate carcinoma: do we need new guidelines for decision making?

Based on epidemiological data of incidence, estimated prevalence of advanced prostate carcinoma in Germany, and the cost of androgen deprivation of different regimens were determined in a study model. We analyzed data, published by the Tumor Registry of Munich, which indicate that from 3,838 patients with carcinomas of the prostate, 38% has been treated exclusively with hormone suppression therapy, 14% of patients had undergone a combined radiation therapy and hormone suppression therapy and 9% underwent combined surgical therapy and hormone suppression therapy. The mean survival time of patients treated with medical therapy alone, for patients treated with combined radiation therapy and medical therapy were 60, 24, and 120 months, respectively. The cost for orchiectomy was estimated as $1,072, and for LH-RH therapy as $224/month. We estimated an incidence of 17,700 (per year) and a prevalence of 115,000 patients with advanced prostate cancer for Germany. Provided all patients received LH-RH treatment a total cost of $308,000,000/year would arise. Provided, all patients underwent surgery a total cost of $19,000.000/year would arise. If all patients received LH-RH agonists, the treatment would amount to $16,944 per patient, independently of the prognostic group; and for surgery $1,072 per patient would arise. Limited health care budgets mandate critical determination and evaluation of costs to provide a component for the complex decision making process. However, they must be complimented by validated data of quality of life, which can than be a basis for new guidelines of decision making.

Adenocarcinoma↗
PubMedDate not supplied

ProteinChip Array analysis of microdissected colorectal carcinoma and associated tumor stroma shows specific protein bands in the 3.4 to 3.6 kDa range.

Multiple pathways of carcinogenesis have been associated with colorectal carcinomas, including the adenoma-carcinoma sequence. The non polyposis coli gene has also been implicated in the pathogenesis of these tumors. Identification of the epithelial-mesenchymal interaction may help in understanding the pathways of invasion and may lead to the development of new, non-invasive tools for the diagnosis and prognosis of colon carcinomas. A ProteinChip Array technology (SELDI=Surface Enhanced Laser Desorption Ionization) has been developed enabling analysis and profiling of complex protein mixtures from a few cells. This study describes the protein analysis of approximately 500-1000 freshly obtained cells from normal and malignant colonic epithelium and its associated stroma by SELDI-TOF-MS (Surface Enhanced Laser Desorption Ionization Time-of-Flight Mass Spectrometry). Pure cell populations of normal and malignant epithelium as well as stroma (without tumor cells) were selected by microdissection from 9 patients. A pattern of 3 peptides of 3.48, 3.55 and 3.6 kDa, which were increased in the colon tumor epithelium and stroma compared to associated normal colon and stroma in all 9 patients, was observed. Coupling microdissection with SELDI represents a powerful tool to identify cell and tumor specific proteins and to understand molecular events underlying the invasive event in colorectal carcinomas. The presence of certain proteins in invasive carcinomas may lead to the development of non invasive biomarkers for the identification or detection of recurrence of colorectal malignancies.

Adenocarcinoma↗
PubMedDate not supplied

Mice transgenic for NPM-ALK develop non-Hodgkin lymphomas.

BACKGROUND: The t(2;5)(p23;q35) translocation is associated with a high percentage of anaplastic large-cell lymphomas (ALCL) of T- or null-cell phenotype. The translocation produces an 80 kDa hyperphosphorylated chimeric protein (p80) derived from the fusion of the anaplastic lymphoma kinase (ALK) with nucleophosmin (NPM). The NPM-ALK chimeric protein is an activated tyrosine kinase that has been shown to be a potent oncogene and presumably plays a causative role in lymphomagenesis. MATERIALS AND METHODS: A transgenic mouse line was generated, where the human NPM-ALK cDNA is driven by the lck promoter conferring transgene expression to early T-cells. RESULTS: Mice rapidly developed large cell lymphoblastic lymphomas with a median latency of 8 weeks, primarily involving the thymus, with lymph node as well as histologically evident extranodal organ infiltration by large tumor cells. CONCLUSION: The transgenic approach described provides direct evidence for the strong transforming potential of NPM-ALK in T-cells and furthermore represents a system for the analysis of the oncogenic events mediated by NPM-ALK in vivo, which might be instrumental in the development of tyrosine kinase inhibitor therapies of potential clinical use.

Animals↗