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Lymphomas comprise a variety of entities with remarkable clinical heterogeneity. This review summarizes the current knowledge on the pathogenesis of major mature B-cell lymphoma subtypes for clinicians working outside the field of hemato-oncology. The understanding of the pathogenesis of lymphomas is linked to the knowledge on normal B-cell differentiation. The clinical diversity is manifested in the different mechanisms involved in lymphomagenesis that include characteristic chromosomal translocations deregulating proto-oncogenes, and inactivation of tumor suppressor genes through deletions and mutations. Gene-expression profiling has dissected certain lymphomas into morphologically indistinguishable, but clinically important subgroups and uncovered pathways suitable for specific therapeutic interventions.

Die Expression von Genen, die Zellwachstum und -proliferation regulieren, ist bei Krebserkrankungen verändert oder mutiert und führt zu unkontrollierter Zellzyklus-Progression. Zu den potentesten Wachstumsregulatoren zählen sowohl TGF-β1 als auch p21 und c-myc. TGF-β1 (Transforming Growth Factor beta 1) reguliert in Assoziation mit seinem Bindungsprotein sLTBP-4 (»short form« des Latent TGF-β Binding Protein 4), das als wichtigster Modulator der TGF-β1-Bioverfügbarkeit gilt, verschiedenste Funktionen in epithelialen Zellen, wobei seine antiproliferative und somit tumorsuppressive Wirkung eine Hauptfunktion darstellt. Ein Mangel an TGF-β1 führt sowohl zu einer reduzierten Expression des tumorsuppressiven CDKI (Cyclin-abhängigen Kinaseinhibitoren) p21, als auch zu einer vermehrten Expression des Protoonkogens c-myc. Beide Mechanismen bedingen sich gegenseitig, sind somit prokanzerogen und induzieren eine verstärkte und ungehemmte Proliferation epithelialer Zellen. In einem in vitro-Modell mit der epithelialen Zelllinie HEK293T wurde in der vorliegenden Arbeit mittels quantitativer Expressionsanalyse untersucht, inwiefern p21 und c-myc in Zellen mit einer modulierten LTBP-4-Expression einer differentiellen Expression unterliegen. Ziel war hierbei das nähere Verständnis der Korrelation des TGF-β1-Bindungsproteins LTBP-4 mit dem CDKI p21 und dem Protoonkogen c-myc in der Karzinogenese epithelialer Zellen. Im Rahmen der molekularbiologischen Untersuchungen wurde zunächst das Genesilencing sowie die Überexpression des sLTBP-4-Gens in HEK293T-Zellen etabliert. Die Ergebnisse der proteinbiochemischen Untersuchungen ergänzten auf qualitativer Basis den molekularbiologischen, quantitativen Nachweis einer erfolgreichen sLTBP-4-Überexpression in HEK293T Zellen. In diesen Zellen wurde das sL4-V5-Fusionsprotein regelmäßig detektiert, was eine erfolgreiche Translation dokumentiert. In den folgenden qPCR-Analysen unterlagen die Gene TGF-β1, p21 und c-myc im vorliegenden in vitro - Modell des sLTBP-4-knock-down entgegen den Erwartungen keiner Expressionsregulation. In sLTBP-4-überexprimierten Zellen wurde eine vermehrte Genexpression von TGF-β1 und p21 sowie eine verminderte c-myc-Expression wie erwartet festgestellt. Die Ergebnisse zeigen somit eine Wechselbeziehung der untersuchten Zielgene im sLTBP-4-Überexpressionsmodell und verdeutlichen deren Expressionskorrelation in der Karzinogenese epithelialer Tumoren., The expression of genes regulating cell growth and proliferation, such as TGF-β1, p21, and c-myc, can be altered or modified in the process of carcinogenesis in epithelial tumors and therefore results in uncontrolled cell cycle progression. TGF-β1 (transforming growth factor beta 1) in association to its binding protein sLTBP-4 (»short form« of latent TGF-β binding protein 4) which is an important modulator of TGF-β1-bioavailability regulates different functions in epithelial cells. Its antiproliferative and therefore tumorsuppressive effects represent a major cellular function. A reduced availability of TGF-β1 results in reduced expression of tumorsuppressive CDKI`s (cyclin dependent kinase inhibitors), in particular p21, as well as in augmented expression of protooncogenes, in particular c-myc. Both mechanisms depend on each other, are procancerogenic and induce enhanced and unarrested proliferation of epithelial cells. In the present project it was analyzed using an in vitro model with the epithelial cell line HEK293T, wether p21 and c-myc in cells with altered LTBP-4-expression undergo a differential expression pattern themselves. The aim of this project was to get a closer insight into the correlation of the TGF-β binding protein LTBP-4 with the CDKI p21 and the protooncogene c-myc during the carcinogenic process of epithelial cells. Gene silencing as well as transient overexpression of the sLTBP-4-gene in HEK293T cells was established under in vitro conditions. The quantitative molecular biological proof of sLTBP-4 overexpression in HEK293T cells through qPCR inquisition was supported by western blot analysis. These proteinbiochemical investigations completed the qPCR survey on a qualitative basis. The sL4-V5 fusion protein was regularly detected, which documents a successful translation. The following qPCR analysis showed contrary to the expectations that there was no regulation of expression of the genes TGF-β1, p21, and c-myc in the model of sLTBP-4-knock-down. Further on it was expected to detect an enhanced gene expression of TGF-β1 and p21, as well as a reduced expression of c-myc in sLTBP-4-overexpressed cells. In this case the analysis showed an upregulation of TGF-β1- as well as p21-expression and a slightly reduced expression of the c-myc-gene. The results of this study indicate a correlation of the tested target genes in the model of sLTBP-4-overexpression and clarify their interdependency in the process of carcinogenesis in epithelial neoplasia.

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies worldwide and shows increasing incidence. Multimodal strategies against HCC include primary (e.g. immunisation) and secondary (e. g. antiviral therapy) prevention, surgical approaches, novel specific systemic therapies (targeted therapy), and the treatment of comorbidity (cirrhosis). New molecular approaches are currently under development and tackle several specific targets. In this context pathology is needed in many aspects: experimental strategies, development of valid tumor-relevant diagnostic tests as well as morphological evaluation in the context of clinical studies and finally in routine diagnosis.

The goal of the present research study is to investigate the m-RNA-patterns of the proto oncogenes c-jun, c-myc and c-fos after balloon dilatation by semiquantitative RT-PCR in a porcine model. We generated successfully a simple and applicable method for this study. This method allowed us to determine short sequences of porcine c-myc and c-jun gene. We could not detect any change in m-RNA patterns due to a too small number of vessels used in this study. Nevertheless we saw a reduction in m-RNA expression of c-jun and an increase in m-RNA expression of c-fos after balloon dilatation. We could not find the so far describes increase in c-jun and c-myc gene expression. Additionally we could proof by a histological preparation of the vessels that dilatated and control-vessels are not damaged by dilatation and preparation. Further all vessel walls were found to be intact. There was no proof of denudation., Ziel der Arbeit war die Ermittlung der mRNA Muster dreier Proto-Onkogene nach Ballondilatation in einem serumfreien Modell mit Hilfe einer zu etablierenden semiquantitativen RT PCR ohne die Verwendung radioaktiver oder fluoreszierender Substanzen. Zunächst konnten dafür die noch nicht bekannte c-jun und c-myc Gene des Schweins in kurzen Sequenzabschnitten erfolgreich ansequenziert werden. Um für die Sequenzierung geeignete homogene Fragmente zu erhalten, wurde mit Primern, die durch Vergleiche bekannter c-myc bzw. c-jun Sequenzen anderer Spezies konstruiert wurden, eine spezifische PCR durchgeführt. Anschließend konnten die Fragmente aus den Agarosegelen in sehr guter Qualität eluiert werden, wobei diese Methode bisher nicht genutzt wurde und hier zunächst optimiert werden mußte. Als problematisch erwiesen sich in den Vorversuchen die anfangs verwendeten Schlachthofgefäße. Mechanische Belastungen der Gefäße während der Entnahme aus den Schweinen im Schlachthof waren nicht zu verhindern. Um eine Verzerrung der Ergebnisse zu vermeiden, wurden für die semiquantitativen PCRs sowie für den Nachweis der Primerspezifität ausschließlich Karotiden verwendet, die unter OP Bedingungen durch Tierärzte des MPI Bad Nauheim entnommen wurden. Diese Gefäße wurden nach einer standardisierten Methode präpariert, dilatiert sowie teilweise mit Kollagenase A behandelt und anschließend inkubiert. Die RNA-Isolierung erfolgte auf chemischen Weg mittels Phenollösungen. Auch dieses Protokoll mußte hier erst optimiert werden. Zudem konnte ein effizientes Verfahren der Homogenisierung, alternativ zur Zerkleinerung, mit Hilfe von Ultraturax oder Ultraschall etabliert werden. Für die nachfolgenden PCRs konnten spezifische Primer entsprechend den beiden sequenzierten Abschnitten sowie für c fos, dessen Sequenz der Gendatenbank entnommen wurde, konstruiert werden. Nachdem der Nachweis der Primerspezifität gelang, konnten mit semiquantitativen PCRs, die in Vorversuchen optimiert wurden, Rückschlüsse auf die mRNA Spiegel in den Ausgangsproben gezogen werden. Die im Verlauf dieser Arbeit entwickelte Methode zur semiquantitativen Analyse von Genexpressionen mittels RT PCR ist gut geeignet, um unterschiedliche mRNA Spiegel nachzuweisen. Voraussetzungen sind, daß man Vergleiche zum Zeitpunkt des exponentiellen Reaktionsverlaufs der PCR trifft und daß gleiche Mengen an cDNA in die Reaktion einsetzt werden. Als Ergebnis der semiquantitativen PCRs fand sich eine verminderte Genablesung des c jun Gens bei den vom Endothel befreiten Gefäßen bei einer Dilatation und Inkubation in serumfreien Medien sowie eine Erhöhung der c fos Expression bei Gefäßen ohne Kollagenasebehandlung, die jedoch aufgrund der geringen Fallzahl nicht statistisch signifikant war. Die bislang unter in vivo-Bedingungen – d.h. unter dem Einfluß von Faktoren des Serums und aus Thrombozyten - beschriebene Steigerung der c-jun- und c-myc-Genexpression endothelhaltiger Gefäße konnte nicht nachgewiesen werden. Weiterhin zeigte sich eine deutliche Hochregulation des Aktin Gens in beiden Versuchsreihen, eine Hochregulation des sm MLCK Gens sowie eine verminderte Expression des GAPDH Gens bei den endothellosen Gefäßen. Diese nachgewiesenen Veränderungen der mRNA-Spiegel der Proto-Onkogene jun, myc und fos nach Ballondilatation wurden erstmalig in einem thrombozyten- und serumfreien Tiermodell beobachtet. Bisher in der aktuellen Literatur beschriebene Modelle sind immer in serum- oder thrombozytenhaltigem Milieu durchgeführt worden. Damit ist das Ergebnis im Einklang mit den diesbezüglichen aktuellen Veröffentlichungen in der Literatur. Zusätzlich konnte mit histologischen Präparaten von den Gefäßen in HE- und EvG/Elastica-Färbungen belegt werden, daß sowohl dilatierte als auch Kontrollgefäße nicht bei der Präparation zerstört wurden und die Gefäßwand nach Dilatation intakt war. Beweise für eine Denudation zeigten sich nicht.

Phosphoinositide 3-kinase (PI3-K) is a heterodimeric enzyme involved in the regulation of mitogenesis, apoptosis, cell adhesion, and motility. PI3-K was suggested as a protooncogene in human cancer. To determine the expression of PI3-K during cancerogenesis and tumor invasion of HNSCC, we investigated normal and dysplastic epithelium of the oral cavity, squamous cell carcinoma and lymph node metastasis by immunohistochemistry. The strongest immunoreactivity for p85alpha and p110alpha was found in invasive tumors and their metastases. Carcinomas in situ showed a focal positivity. Dysplasias and normal epithelium reacted predominantly negatively. The PI3-K inhibitor LY294002 inhibited proliferation and invasion of the HNSCC cell line CAL-27 and induced apoptosis in vitro. Our data suggest PI3-K as a marker of malignancy and tumor invasion. We suggest including PI3-K in the multistep carcinogenesis model of HNSCC. In addition, PI3-K is a potential target for pharmacological intervention.

Hereditary medullary thyroid carcinoma (MTC) is caused by germline mutations of the RET proto-oncogene. A genotype - phenotype correlation has been established, showing clustering of mutations in exons 10 and 11 in classical MEN 2 A syndrome, in exon 16 codon 918 in MEN 2 B syndrome and in exons 13-15 in familial MTC. A line of evidence suggested that the development and the aggressiveness of MTC in the different cancer syndromes is variable. Aim of this study was to compare the phenotype of exon 13-15 mutations with that of exon 11 mutation and possibly draw therapeutical consequences.We compared the phenotype of 47 patients with mutations in exon 13-15 with 66 patients with exon 11, codon 634 mutation, the classical MEN2A. Patients were further subdivided as index and screening patients.Mean age of 19 index patients with codon 790, 791, 804 or 891 mutation was significant higher compared with 18 index patients with codon 634 mutation (mean age at diagnosis 50+/-12 years; range 30-69 y vs mean age 31+/-9 years; range 17-49 y), tumor stage at operation was favourable (C-cell hyperplasia n = 1; stage I n = 8; II n = 3; III n = 2; IV n = 2; no operation n = 1; no information n = 2 vs stage I n = 3; stage II n = 6; stage III n = 4, no information n =5), cure rate was better (56 % vs 38 %) and the death rate was lower (n = 2 vs n = 4). In screening patients no differences concerning the age, tumor stage, cure and death rate between patients with exons 13-15 and codon 634 mutations were seen.MTC in patients with exon 790, 791, 804, 891 mutations displayed a late onset and an indolent course compared to codon 634 mutation, this has to be taken into account when recommending timing and extent of prophylactic surgery.

The development of cancer is one of the most intensively studied areas of medical research resulting in an immense quantity of data. Therefore, the purpose of this article is to give an overview of the basic principles of cancer development. Key words such as multi-step carcinogenesis, cell cycle, protooncogene, tumor suppressor gene, DNA repair gene, apoptosis and telomeres are explained and described in examples. This paper aims to connect recent information of molecular and cellular biology in an overview of cancer origin and development.

The Ets 1 transcription factor, the founder of the ets gene family of transcriptional regulators, has strongly been supposed to play a role in angiogenesis under both physiological and pathological conditions including tumor vascularization. An in vivo role has nevertheless not yet been proven. We therefore investigated whether an Ets 1 antisense oligodesoxynucleotide (ODN) blockade effectively inhibits in vivo angiogenesis in the chicken chorioallantois membrane-assay. We used a 20-mer phosphorothioate directed against the AUG initiation codon and a short 3' sequence of the c-ets 1 mRNA (5'-AGATCGACGGCCGCCTTCAT-3') in order to block Ets 1 expression. Three quantities of either antisense or negative control sense ODNs were directly applied on the chorioallantois membrane on day five of development and results evaluated on day seven. No effect on angiogenesis was seen in the antisense group treated with 2.5 micrograms ODN/egg compared to the sense control group. In contrast chorioallantoic blood vessel numbers and diameters were considerably reduced after application of 5 micrograms antisense ODN. 10 micrograms of either antisense or sense ODNs turned out to be toxic: all 6 embryos had died on day seven. Our results are the first proof that the Ets 1 transcription factor is actually necessary for the regulation of in vivo angiogenesis. Its role is probably not restricted to development but also concerns new blood vessel formation during chronic inflammation and tumor vascularization.

When multiple endocrine neoplasia type 2 (MEN2) is suspected, genetic tests are at the centre of screening procedures. It was the aim of this study to compare the diagnostic value of molecular biological investigations with that of conventional biochemical tests.The study cohort consisted of all 144 patients cared for in our department since 1990 with the suspected diagnosis of MEN2 (evidence of a medullary thyroid carcinoma [MTC]), coexistence of two MEN2 tumours or a family history of MEN2. 14 of the 144 patients (from 12 families) were already known to have an hereditary MTC, while the remaining 130 had been referred for further diagnostic investigations.An hereditary MTC was diagnosed in 22 of the 130 patients, a sporadic MTC in 32, while no definitive classification was possible in 20 MTC patients without a positive family history and on whom no mutation analysis had been performed. MEN2 was excluded in 56 family members. All 22 patients with newly diagnosed MTC had abnormally high calcitonin levels. A germ-line mutation in the RET proto-oncogene was found in 8 of the 9 families who had undergone molecular biological tests. The investigate results led to a thyroidectomy in 19 of the 22 patients with hereditary MTC; in all of them the surgical specimen showed C-cell hyperplasia and/o MTC.These results emphasize the importance of genetic tests in family screening. Preoperative measurement of calcitonin remains essential in MEN2 families in whom a germ-line mutation is not known. The choice of the appropriate diagnostic test must be individualized to the particular patients so that optimal results are obtained.

Osteosarcoma is one of the most commonly biopsied primary tumor of bone. High-grade osteosarcomas in particular exhibit a wide spectrum of cytogenetic changes. Molecular cytogenetic studies on osteosarcomas have shown that genomic amplification, especially of both the TP53-binding MDM2 gene and the flanking SAS gene, plays an important role in the biology of these tumors. We applied CGH in order to obtain a global view of DNA-sequence losses and gains in osteosarcoma. CGH was performed on 20 high-grade medullary osteosarcomas (13 primary tumors prior to chemotherapy, 5 tumors after chemotherapy, 2 established cell lines [MB63, HOS58]) using genomic DNA of snap-frozen tumor specimens. CGH revealed DNA copy number aberrations, mostly gains, in all the tumors studied with an average of 18.5 aberrations/tumor (range 8-32). High-level amplifications were observed in all cases (average 4.1 amplifications/tumor [range 1-10]). Amplicons affecting at least five tumors were mapped to 1p21-31 (9/20 cases), 3q25-qter (6/20), 6p12-21 (6/20), 8q12-qter (10/20), 12p11-12 (9/20), 12q12-15 (enclosing MDM2 and SAS loci, 7/20). Losses were most frequently seen at 3p, 10q, 11p and 13 (all 10/20). In conclusion, our CGH data indicated that genomic amplification plays an important role in the biology of osteosarcoma. CGH demonstrated the complexity of genetic aberrations in osteosarcomas. The detection of novel non-random DNA amplifications in our study has defined regions for further targeted molecular genetic research aimed at identifying those oncogenes that are characteristic of osteosarcoma development.

Leiomyosarcoma (LMS) is a rare type of malignant soft tissue tumor occurring predominantly in adults. Up to now only few zytogenetic data resulting from chromosomal banding analyses were obtained from this tumor type. In general, highly complex karyotypes were observed, but no recurrent chromosomal aberrations could be identified. The aim of the present study was to analyze chromosomal imbalances in 14 cases of LMS using comparative genomic hybridization (CGH). Imbalances were detected in all cases analyzed, with chromosomal gains occurring more frequently than losses (9.9 gains/case vs. 6.9 losses/case, respectively). Chromosome arms predominantly overrepresented included Xp (9/14 cases), 5p and 8q (8/14 each), as well as 17p and 17q (6/14 each). Nineteen distinct high level amplifications, indicative for the location of relevant proto-oncogenes in LMS, were identified in nine different tumors. Interestingly, in three cases chromosomal arm 17p was involved. Interphase analysis with probes derived from the commonly amplified region 17p11-p12 revealed, that the tre oncogene is co-amplified and therefore could play a relevant role in LMS development. With regard to losses chromosome 13q was affected in 12/14, 10q in 8/14, and 2p as well as 2q in 7/14 tumors, respectively. The frequent deletions of chromosome 13 with a minimal affected region 13q14-q15 strongly support preliminary molecular evidence, that loss of the RB1 tumor suppressor gene is a critical step in LMS tumorigenesis.

Histological differentiation between chondroma and chondrosarcoma is a common problem in surgical pathology. In a former study (3) we were able to show, that immuno-histochemical p53-accumulation in chondromatous neoplasias might be an additional hint for malignancy. Now we tried to find out, whether p53-accumulation is caused by TP53-aberrations or functional inactivation of p53-wildtype protein by MDM2. For this purpose, paraffin-embedded material of 80 chondromatous neoplasms (18 chondromas, 18 chondromatous neoplasms of uncertain dignity (i.e. cytologically suspicious but without definite invasive growth), and 44 chondrosarcomas (24 GI, 13 GII, 7 GIII)) were screened for TP53 gene-aberrations by means of DGGE (denaturing gradient gel electrophoresis; exons 5-8). The results were correlated with immunohistochemical p53-accumulation (DO-7, DAKO) and MDM2-expression (AB-1, Oncogene). A total of 43% of all chondromatous neoplasms showed TP53-aberrations in DGGE-analysis, i.e. 27% of chondromas, 50% of chondromatous neoplasms of uncertain dignity, 46% of GI-, 46% of GII- and 71% of GIII-chondrosarcomas. Exon 6 (58% of all cases with aberrations) and exon 8 (47%) were affected most frequently. No significant correlation between TP53-aberration and either p53-accumulation or MDM2-expression was present. A statistically significant correlation could be found between p53-accumulation and MDM2-expression (p0.0001). Regarding histological tumor-classification, p53-accumulation and MDM2-expression discriminated between chondromas/chondromatous neoplasms of uncertain dignity and well differentiated chondrosarcomas in a statistically significant manner. In the subgroup of p53-positive and MDM2-negative cases significantly more TP53-aberrations were detected by DGGE-analysis than in the other groups. Interestingly, the subgroup of p53- and MDM2-negative cases showed the second highest rate of TP53-DGGE-aberrations. Nearly 50% of these aberrations, however, were localized in exon 8, a mutation that is known to cause no p53-protein-accumulation. In conclusion, TP53-aberrations occur frequently in chondromatous neoplasms and show no significant association to either immunohistochemical p53-accumulation or MDM2-expression. Functional inactivation of p53 wildtype protein by MDM2-expression seems to be the major cause of p53-accumulation in chondromatous neoplasms and emphasizes the role of these parameters as additional hint for malignancy.

Bone is a common site for metastasis of malignant tumors. These can be recognized radiologically as either lytic or sclerotic lesions since the tumor cells stimulate resident bone cells to cause excessive local resorption or new bone formation. The osteoclast, as the only cell being capable of resorbing bone, is of major importance for the homing of tumor cells in bone and progression of metastasis due to bone destruction. Thus, the improvement of our means of therapeutic intervention towards prevention of tumor progression and pathological fractures will depend on our better understanding of both the molecular basis of bone resorption and the cellbiology of the osteoclast. This article presents our current opinion of the molecular mechanisms of bone resorption by the osteoclast. After describing the morphological features of the osteoclast, aspects such as cell mobility, attachment, enzymes synthesis, transmembrane transport, osteoclast differentiation and function, as well as the protooncogenes c-src and c-cbl and their role in bone resorption are presented in detail.

According to a considerable amount of publications apoptosis plays an important role for radio- and chemotherapy. The most important results related to this issue will be described in 2 independent articles, covering the following topics: Part I: I. definition, morphology, biochemical processes, II. clinical relevant detection assays, III. signal transduction. Part II: significance of apoptosis for radio- and chemotherapy.

Papillary thyroid carcinomas were observed in children living in the Gomel region of Belarus at the time of the Chernobyl reactor accident in April 1986. Radioactive fallout, iodine-131 in particular, led to thyroid doses of10 Gy in some cases. Till now, more than 400 thyroid carcinomas developed. They provide a unique possibility to search for characteristic molecular aberrations. Small fresh frozen thyroid tumor samples from 59 children were available. cDNA after reverse transcription of mRNA was amplified by multiplex PCR and analyzed for the presence of RET rearrangement (PTC1, 2 or 3) by identification-PCR with specific primers and by direct sequencing. A significantly higher prevalence of RET rearrangement was found in the thyroid carcinomas of radiation-exposed children than formerly described for adult thyroid carcinomas. While the prevailing type of RET rearrangement in adult thyroid carcinomas is PTC1 involving RET and the H4 gene, the majority of tumors in radiation-exposed children shows PTC3. In this type of rearrangement the 3'-tyrosin kinase domain of RET becomes dependent on the 5'-regulatory part of the ELE gene. Different breakpoints were found in the ELE gene. Besides ELE/RET transcripts, reciprocal RET/ELE transcripts were expressed indicating a complete inversion of the two genes after double stand break and their functional activity in both rearranged forms. Paracentric inversion on chromosome 10 bringing the functional tyrosine kinase domain of c-RET under the regulatory control of the ubiquitously expressed ELE gene appears to be a typical molecular lesion in thyroid carcinomas of children after radiation. This rearrangement is thought to endow juvenile thyrocytes with a clonal growth advantage and may be a critical initiating event of thyroid carcinogenesis in radiation-exposed children.

In the pig short coronary occlusions induce molecular damage on the protein level in the myocardium, which elicit repair mechanisms by increased transcription and translation, including the activation of potential transcription factors (protooncogenes), genes involved in repair processes (heat shock genes) or calcium-binding genes. Additionally, some growth factors like insulin-like growth factor II show increased transcription in accordance with their function as trophic factors for reversibly injured myocardium. Changes in mRNA levels mostly are due to increased transcription rates and rarely due to prolonged half-life of the mRNA. However, at present our data do not allow us to conclude which genes are causative for myocardial stunning and/or ischemic preconditioning.

Cytogenetic studies and analysis of restriction fragment polymorphism (RFLP) have revealed that chromosomes 9, 11 and 17 are frequently altered in urothelial tumors. There are several tumor suppressor genes that might be involved in the oncogenesis of these tumors. The retinoblastoma suppressor gene and p53 have been the subjects of several recent investigations and have been seen to be altered or inactivated in a significant number of tumors. Proto-oncogenes of the ras family have been studied extensively, and c-Ha-ras alterations have been demonstrated in approximately 10% of urothelial tumors. Other proto-oncogenes seem to be involved less frequently. Although correlations between these molecular genetic findings and clinical parameters have been shown by some investigators, further studies are needed to establish whether molecular data are clinically relevant for prognosis, diagnosis and therapy. The sensitivity of molecular genetic techniques combined with the relatively easy access to primary tumor cells (by biopsy or cytology) make this tumor type an ideal system for further investigation of the molecular genetic basis in the development of human neoplasms.

IL-8 is a chemotactic cytokine with proinflammatory and growth-promoting activities. Recently it has been shown to influence several functions of keratinocytes, including HLA-DR expression, chemotaxis, and proliferation by binding to a specific receptor. Because psoriasis vulgaris is characterized by epidermal hyperproliferation and infiltration of inflammatory cells, we investigated the expression of IL-8 and its receptor in normal and psoriatic epidermis using semiquantitative reverse-transcriptase-polymerase chain reaction. In addition the mRNA levels of the proto-oncogenes c-ras, c-raf, c-myc, and HER-2 were also investigated as potential growth-promoting stimuli in psoriatic epidermis. IL-8 mRNA was only detected in lesional psoriatic epidermis, and IL-8R-specific mRNA was found to be 10 times increased in lesional psoriatic epidermis. There was no significant difference in the protooncogene mRNA levels. In order to test the relevance of the massively increased IL-8R levels in psoriatic epidermis, we investigated the effect of the antipsoriatic drug FK-506 on specific IL-8 and IL-8R mRNA expression. FK-506 dose dependently inhibited IL-8R expression and function. Our data suggest that in psoriatic skin, elevated IL-8 levels and markedly increased IL-8R expression may act in concert to induce the cardinal signs of psoriasis--epidermal hyperproliferation and leukocyte infiltration. IL-8R may prove a molecular target for antipsoriatic drugs such as FK-506.

The human genome contains so-called protooncogenes which can be activated to oncogenes by mutations. Oncogenes contribute to the development of tumours of the nervous system. Some of the oncogenes are related to growth factors or to cytogenetic changes in tumours. A survey is given of current research on oncogene loci in neuroepithelial tumours by recombinant DNA techniques. In neuroblastomas the amplification of the oncogene N-myc is associated with a poorer prognosis. In neuroepithelial tumours the amplification of c-erbB, which is in part homologous to the epidermal growth factor receptor gene, is restricted to malignant neoplasias. An enhanced expression of the oncogene c-sis, which codes for the platelet-derived growth factor, is found in 85% of malignant gliomas. Many studies of relatively fewer cases suggest the influence of other, further oncogenes in the group of neuroepithelial tumours.

The hormonally induced changes in the breast during pregnancy make the diagnosis of breast cancer difficult. Furthermore, examinations during pregnancy tend to concentrate only on the pregnancy itself. In this report the clinical, pathological and immunohistochemical results from 7 patients with breast cancer during pregnancy are presented. All women first noticed the tumor by self-examination. The time periods between discovery of the tumor and medical treatment were between 4 and 22 weeks. An overexpression of c-erbB-2-oncogene coded transmembrane protein p185 could be demonstrated in 4 cases. Of the seven patients, 5 have already passed away. Three of the deceased had p185-positive tumors, and died 4, 8 and 21 months after diagnosis. The two p185-negative patients lived 34 and 65 months post diagnosis. Despite the small amount of cases presented, a trend can be seen that p185 may be an additional prognostic factor for breast cancer in pregnancy.

Premalignant and malignant lesions of the cervix uteri and endometrium were analyzed for the presence of human papillomavirus (HPV) DNA and c-myc or c-erbB2/neu oncogene expression. HPV DNA was detected by PCR in 100% of the cervical carcinomas and CIN lesions, but also in endometrial lesions (3/8 adenocarcinomas, two hyperplasias and one adenomyosis uteri). Myc-overexpression was found in 25-30% of the cervical carcinomas and severe dysplasias, but not in endometrial lesions. C-erbB2 was overexpressed in 4/11 endometrial carcinomas and 3/19 CIN3 lesions. The implications of these results are discussed.

Proto-oncogenes, the normal equivalents to the transforming genes of mammalian tumorigenic retroviruses, are implicated in essential biological processes of normal human cells, like differentiation and proliferation. In vivo and in vitro studies clearly demonstrate that activation of proto-oncogenes with subsequent transformation in tumorigenic oncogenes plays an important role in induction and acceleration of the malignant disease, and also determines metastatic spread and development of resistance to chemotherapy in certain neoplasias. Investigation of these genes and analysis of their activation state should routinely be introduced in staging of hematological neoplasias, thus contributing to refinement of histopathological classification, clearer discrimination between reactive and neoplastic conditions and understanding of pathophysiological processes. Furthermore, impact on definition of high risk patients and novel therapeutic concepts based on a better definition of tumour biology may be expected from these studies. "Molecular cytology" combines detection of oncogenetic mRNA and the relevant oncoprotein on the single cell level by using "mRNA-in situ hybridization" and immuno-histochemistry. Application of this technique will allow to determine the mechanisms regulating the expression of oncogenes to define functional heterogeneity of tumour cell subsets and to clarify the relevance of minimal residual disease.

Diagnosis- and/or prognosis-related alterations of (proto) oncogenes may be detected in neuroblastoma (N-myc), carcinoma of breast and ovary (HER2/neu), NHL (c-myc, bcl-2), CML (c-abl/bcr), and some other neoplasias. A wide variety of methods for the detection of gene alterations can be applied. The methods of detection have to be chosen according to the expected mechanisms of oncogene activation, the availability of adequately prepared tissue, and the technical standard of the laboratory. The sensitivity, specificity, and quantitation of morphological techniques (immunohistochemistry and in situ hybridization) is restricted and their results have to be interpreted most carefully. Whenever possible, at least two different techniques should be used, preferably on two different levels, i.e. RNA/DNA and protein. Furthermore, the combination of morphological and non morphological methods should be aspired.

In each cytoblast of mammals about 30 protooncogenes are present which during the embryonic, the fetal and the postnatal development, respectively, in certain cell types may temporarily or permanently be used for the formation of certain proteins. A part of these proteins is of importance for the furthering of the division (DNA-replication) and the differentiation of the cells. According to the qualities in the proteins formed by protooncogenes the protein kinases, the GTP binding proteins and the DNA binding proteins are differentiated. Under the influence of carcinogens and of cocarcinogens several protooncogenes are changed in their structure and displaced, respectively, within certain chromosomes. Thus they are transduced into oncogenes and evoke an increased formation of transforming proteins which initiate a dysregulation of the transcription in the nucleus. Several aspects of the activation of protooncogenes, of the development of tumours as well as of the origination of tumours by recessive mutation are described.

Three examples are presented to illustrate the importance of retroviruses and associated oncogenes in neoplasms of the immune system. In adult T-cell leukemia/lymphoma the HTLV I-provirus is often integrated in the human genome on chromosome 8 adjacent to the c-myc protooncogene. Cytogenetic studies of Burkitt's lymphoma (translocation of a chromosome 8 fragment) and a case of mycosis fungoides (trisomy of chromosome 8) indicate that the same oncogene may possibly be activated not only by retroviruses, but also by chromosomal aberrations.

Chromosomal findings in malignant lymphomas are correlated to the histopathology and the immunologic phenotype of lymphoma subgroups. The prognostic significance of a cytogenetic analysis and its value for therapy planning are discussed. With respect to tumorigenesis it is emphasized that a number of proto-oncogenes and genes for cell differentiation, such as immunoglobulin and T-cell receptor genes, have been localized at sites of recurring chromosomal rearrangements. One chapter deals with cytogenetic data in correlation to findings of DNA recombination studies in Hodgkin's disease.

Non-random, specific chromosome aberrations can be found by direct preparation in the karyotype of the malignant cell populations of the various leukemias and solid tumors in childhood. These chromosomal deletions in neuroblastoma, Wilms-Tumor, reticlassification and prognosis. There are mainly chromosomal deletions in neuroblastoma, Wilms-Tumor, retinoblastoma whereas translocations predominate in leukemias and lymphomas.

This short review article discusses methods and results of oncogene research in yeast. Current knowledge of the sequence, expression and biological function of ras-homologous genes of the yeast Saccharomyces cerevisiae is presented, as well as the implications of these findings for oncogene research in mammals. We review recent examples of highly conserved eukaryotic genes involved in growth control and mitosis control, including recent work from our own laboratories.