High grade aggressive lymphomas have high mortality. By their nature, more than 40% of patients die from these diseases even with the improved treatment strategies currently available for oncology patients. The characteristic feature is that they are functionally heterogeneous and therefore have different biological and molecular signatures which make it difficult for all groups to respond to same line of treatment. Based on the above, I set out to look at the impact of viral and cellular gene products on these groups of diseases: In chapter 3 I developed monoclonal antibodies against HERV‐K10. I subsequently investigated their expressions in aggressive lymphomas including Diffuse Large B‐cell lymphoma, Hodgkin’s lymphoma and Primary CNS lymphomas. I showed HERV‐K10 is expressed in cell lines of aggressive lymphomas, but not in paraffin‐embedded tissues. In chapter 4 I showed that the expression of ATM using immune‐histochemistry techniques in aggressive lymphomas does offer a guide to prognosis and treatment. Nearly 30% of Diffuse Large B‐cell lymphomas express ATM, 55% of Hodgkin’s lymphomas and more than 80% of Primary CNS lymphomas. I also showed there is a correlation of ATM expression and EBV‐driven aggressive lymphomas and that this has a poor prognostic significance. Chapter 5 analysed the results obtained by generating, validating and evaluating data base of DLBCL and PCNSL from a retrospective cohort over a 17‐year period. The results confirmed that prognostic indicators including ATM, S1PR2, Autotaxin and EBV using immuno‐histochemistry techniques help with categorising aggressive lymphomas into different prognostic groups and does influence future management. In summary, my results showed there is a critical place for immuno‐histochemistry techniques in convincingly helping understand the expressions of viral and cellular gene products in aggressive lymphomas and in contributing positively to their management.

Präeklampsie (PE) ist eine Komplikation, die während der Schwangerschaft auftritt, fast 2-8% aller Schwangerschaften betrifft und human spezifisch ist. PE ist eine der Hauptursachen für den Tod von Mutter und Kind. Eine abnormale Plazentaentwicklung aufgrund einer verminderten Trophoblasteninvasion und einem gestörten Umbau der Spiralarterien trägt zur Pathogenese der PE bei. Klinisch wird die PE durch Bluthochdruck und Proteinurie, auftretendnach der 20. Schwangerschaftswoche, diagnostiziert und kann durch eine Funktionsstörung von Organen begleitet werden. Bei besonders schweren Verläufen ist die frühzeitige Endbindung die letzte Möglichkeit das Überleben der Mutter zu gewährleisten. Das Ziel dieser Studie ist es, weitere Gene zu identifizieren, die durch ERVs in der menschlichen Plazenta spezifisch reguliert werden und in PE dysreguliert sind. Um dieses Ziel zu erreichen, wurde das Transkriptom von primären menschlichen Trophoblastenzellen von 5 gesunden und 5 früh einsetzenden PE-Plazenten mittels RNA-Sequenzierung analysiert. Es wurden 335 Gene identifiziert, welche eine höhere Expression in den Trophoblastenzellen im Vergleich zu anderen Geweben aufwiesen. Zusätzlich zeigten einige der Gene (n=88) eine Co-Regulation der Expression durch retrovirale LTRs (10-kb 5‘ des transcription start side (TSS) des Gens). Hauptinteresse lag hierbei auf den Genen, welche ebenfalls eine Dysregulation in der PE aufwiesen (n = 16). Diese Studie identifizierte EPS8L1, das durch primaten-spezifisches ERV-LTR (MLT1G1) in Trophoblastenzellen reguliert wird, als einen wichtigen Faktor in der Entwicklung der menschlichen Plazenta. EPS8L1 ist in der PE Plazenta dysreguliert und involviert in mehrere Signalwege und die Funktionalität von Trophoblasten wie Invasion, Angiogenese und Redoxhomöostase. Hierdurch führt diese Arbeit zu einem besseren Verständnis der PE und deren human-spezifischer Natur. / Preeclampsia (PE) is a complication that occurs during pregnancy and affects almost 2-8% of all pregnancies and is often regarded as a human-specific disorder.1,2 PE is one of the major causes of maternal and fetal death.1 Failure of the trophoblast cells to invade into the maternal decidua results in the improper remodeling of spiral arteries leading to PE pathogenesis. Clinically, it is diagnosed as a maternal syndrome, diagnosed by the new-onset of hypertension and proteinuria or other end-organ dysfunction after the 20th week of pregnancy. So far, the only effective treatment of the disorder is the removal of the placenta tissue and delivery of the infant. The aim of this study is to identify additional genes that are regulated by the human ERV-LTRs in the human placenta specifically, and are dysregulated in PE. To achieve this aim, the transcriptome of primary human trophoblast cells of 5 healthy and 5 early-onset PE placentas were analyzed by RNA sequencing (RNA-seq). RNA-seq analysis identified genes (n=335) with stronger expression in the trophoblast cells as compared to other human body tissues. Additionally, some of the genes (n=88) showed co-regulation of expression by the human ERV-LTRs in their vicinity (10-kb upstream of transcription start side (TSS) of the gene). Since my interest was to identify the new targets of PE pathogenesis, so I focused on genes (n=16) with dysregulated expression in women presented with PE. This study identified a new gene EPS8L1, regulated by primate-specific ERV-LTR in trophoblast cells that has a predominant role in the human placenta development and demonstrated that its dysregulation affected multiple pathways involved in trophoblast function like invasion, angiogenesis and maintenance of cell redox homeostasis. Furthermore, this study leads to the better understanding of the disease by explaining certain aspects of human-specific nature of PE.