Daten des humanen Genomprojektes zeigen, dass ca. 8% des gesamten humanen Genoms aus retroviralen Sequenzen besteht. Der überwiegende Teil dieser Proviren ist aufgrund verschiedener Mutationen defekt. Im Gegensatz zu allen anderen HERV Proviren scheinen einige HERV-K Proviren intakt zu sein und besitzen offene Leserahmen für alle viralen Proteine. Die Familie des humanen endogenen Retrovirus K HML2 umfasst ca. 30 eng verwandte Proviren. Zusätzlich zu den Strukturproteinen Gag und Env und der Reversen Transkriptase, exprimiert HERV-K zwei regulatorische Proteine, Rec und Np9. Beide sind im Nukleus lokalisiert und tumorigene Eigenschaften bzw. eine Expression in Assoziation mit Tumorgeweben wurde nachgewiesen. Neben Zelllinien, wie die Teratokarzinomzelllinie GH und einigen Brustkrebszelllinien, für die die Expression von HERV-K mRNA und die Produktion von Viruspartikeln bekannt ist, konnte die Expression von HERV-K Proteinen und Partikeln für Melanomzellen gezeigt werden. Volllängen mRNA von HERV-K war in allen untersuchten humanen Proben nachweisbar. Gespleißtes env und rec war in 39% der Gewebe und in 38% der Melanomzelllinien exprimiert. Zusätzlich werden HERV-H, -R und -W exprimiert. Von den auf spezifische Antikörper gegen HERV-K Proteine untersuchten Seren der Melanompatienten waren 16% positiv für das transmembrane Hüllprotein, jedoch reagierte kein Serum mit Re oder Np9. Da im Zuge der Entstehung von Tumoren immer auch eine Dedifferenzierung der entarteten Zellen diskutiert wird, wurde die Expression von HERVs in undifferenzierten, embryonalen Stammzellen bestimmt. In den untersuchten embryonalen Stammzellen lässt sich Volllängen mRNA, sowie gespleißte env, rec und np9 mRNA nachweisen. Während der Differenzierung zu neuronalen Vorläuferzellen sinkt die Expression jedoch wieder auf ein mit normalen Zellen vergleichbares Niveau. Obwohl gespleißte RNA und virale Proteine von HERV-K vor allem in Tumoren und Tumorzelllinien exprimiert werden, ist deren Funktion während der Tumorentstehung noch immer ungeklärt. Auch die Bedeutung der HERV-K Expression in humanen Stammzellen ist noch unklar, insbesondere in Hinblick auf eine mögliche Tumorigenität. / In contrast to all other human endogenous retroviruses, proviruses of the human endogenous retrovirus family HERV-K have maintained open reading frames for all viral proteins. Although most proviruses are defective, structural proteins Gag and Env, the reverse transcriptase and two regulatory proteins, Rec and Np9, have been described. Rec resembles the Rev protein of HIV and tumourigenic potential was confirmed. Np9 as well is located in the nucleus and expression in association with tumour tissues was observed. Additionally to cell lines known to produce HERV-K virus particles, such as the teratocarcinoma cell line GH and breast cancer cell lines, recently melanoma cells were described to express HERV-K proteins and particles. In order to study the expression of HERV-K, -H, -R and -W, in melanoma cell lines and biopsies primer sets were used. Antisera specific for HERV-K proteins were used for immunohistochemistry and sera from melanoma patients were investigated for HERV-K specific antibodies. Full length mRNAs of all HERVs were found in all human cells. Spliced env and rec of HERV-K were detected in 39% of the melanoma biopsies and in 38% of the melanoma cell lines. Expression of HERV-K in situ was shown by immunohistochemistry. In addition, 16% of the patients sera tested showed antibodies against the HERV-K transmembrane envelope protein, but no antibodies against Np9 or Rec could be detected. A certain dedifferentiation of cells as a consequence of tumour development is discussed. Therefore the expression of HERV-K in undifferentiated embryonic stem cells was investigated. The investigated stem cells showed expression of HERV-K full length, env, rec and np9 mRNA. Although the expression decreased with differentiation to neuronal precursor cells. Even though HERV-K mRNA and proteins were expressed in a high percentage of melanomas their function in tumour development is still unclear. As well as the meaning of the HERV-K expression in embryonic stem cells, particularly for a tumourigenic potential.

The motivation of this research is to propose innovative nonlinear and optimal control design algorithms, which can be used in real life. The algorithms need to be computationally efficient, should deal with control constraints and should operate under state feedback. To show the efficacy of algorithms, automatic therapy for different cancer problems is chosen to be the field of application. In this thesis, first an advanced control design technique called ’optimal dynamic in-version’ has been successfully experimented with control constraints. The proposed approach has subsequently been shown to be quite effective in proposing automatic drug delivery schemes with simultaneous application of chemo and immunotherapy drugs for complete elimination of cancer cells in melanoma (a skin cancer) as well as glioma (a brain cancer). As per the current practice, the amount of drug dosages are generally given based on some apriori statistical study with a very small sample size, which in reality may either also lead to drug toxicity (due to excessive drug) or may become ineffective (due to insufficient drug) for a particular patient. Subject to the fidelity of the mathematical model (which has been taken from published literature), it has been shown in this thesis that nonlinear control theory can be used for computation of drug dosages, which can then be used in a feedback strategy, thereby customizing the drug for the patient’s condition, to cure the disease successfully. Next, attention has been shifted to impulsive control of systems. Such impulsive con-trol systems appear in many other applications such as control of swings, control of spacecrafts and rockets using reaction control system, radiotherapy in cancer treatment and so on. Two impulsive control design philosophies are proposed in this thesis. In one approach, recently proposed model predictive static programming (MPSP) has been extended for impulsive control systems and has been named as impulsive-MPSP (I-MPSP). In other approach, another recent development, namely the Pseudospectral method has been utilized to consider both the magnitude of the control impulses as well as the time instants at which they are applied as the decision variables. It can be noted, that to the best of the knowledge of the author, the time instants of control application, being considered as decision variables is being proposed for the first time in the nonlinear and optimal control framework. Both I-MPSP and Pseudospectral methods are computationally quite efficient and hence can be used for feedback control (I-MPSP happens to be computationally more efficient than the Pseudospectral method). Applicability of the proposed extensions have been shown by solving various benchmark problems such as (i) a scalar linear problem, (ii) Van der Pol’s oscillator problem and (iii) an inverted pendulum problem. Finally the applicability of the proposed I-MPSP strategy has been shown by solving challenging problems such as radiotherapy treatment of head and neck and adenocarcimona cancers. Radio-therapy model is considered with oxygen effect, in which radiosensitivity parameters are considered in different forms. Head and neck cancer is considered with constant radiosensitivity parameters and adenocarcinoma is considered with constant, linear, quadratic and saturation model of radiosensitivity parameters. Note that toxicity constraints on normal tissue, which are nonlinear control constraints, are also successfully incorporated in this control design.

Made available in DSpace on 2014-08-20T14:37:54Z (GMT). No. of bitstreams: 1 tese_maria_cecilia_florisbal_dame.pdf: 53923 bytes, checksum: e82c085a8b324064158221bf46a754ba (MD5) Previous issue date: 2013-12-12 / This thesis is a continuation of a research project started with a diagnosis of dermatosis mechano-bullosa in a herd of buffaloes from a farm in southern Rio Grande do Sul. After this diagnostic it was created an experimental herd where several congenital defects and / or hereditary disorders have been diagnosed during more than two decades. These diseases were studied by a research group which the author of this thesis is a member. Thus, three papers are presented: the first one is a literature review about what has been diagnosed in Brazil on congenital defects and hereditary diseases in buffalo. It was concluded that undesirable genes are widespread in the population of buffaloes in the country; the second was a study conducted in partnership with UNESP / Jaboticabal, SP and UFCG / CSTR-Patos, PB to identify the mutation in the gene that determines the oculo-cutaneous albinism in Murrah buffalo. Another paper was accomplished to describe the occurrence of malignant melanoma in two albino buffalo. Although it is not a congenital or hereditary disease it was observed only in the buffalo with oculocutaneous albinism and probably the condition is associated with a predisposition of these animals to develop tumors in the skin. / Esta tese dá continuidade a um projeto de pesquisa iniciado com o diagnóstico de dermatose mecanobolhosa em 1985 em um rebanho de búfalos pertencente a uma propriedade da zona sul do Rio Grande do Sul. A partir desse diagnóstico foi criado um rebanho experimental no qual por mais de duas décadas foram diagnosticados diversos defeitos congênitos e/ou hereditários que foram estudados por um grupo de pesquisa do qual faz parte a autora desta tese. Assim sendo, são apresentados três artigos científicos: o primeiro trata-se de uma revisão bibliográfica sobre o que foi diagnosticado no Brasil em relação a defeitos congênitos/doenças hereditárias em bubalinos concluindo-se que alguns genes indesejáveis estão disseminados na população de búfalos no País; o segundo foi um trabalho realizado em parceria com a UNESP/Jaboticabal, SP e com a UFCG/CSTR-Patos, PB que identificou a alteração no gene que determina o albinismo óculo-cutâneo em búfalos da raça Murrah. O terceiro artigo trata-se da descrição de melanoma maligno observado em dois búfalos albinos. Embora não seja um defeito congênito ou hereditário este neoplasma ocorreu somente nos búfalos com albinismo óculo-cutâneo do rebanho e acredita-se que a condição esteja associada à predisposição desses animais a desenvolverem tumores de pele.

Beside tumor cells themselves, tumors consist of many non-malignantly transformed cellular elements and an extracellular matrix. This so-called tumor microenvironment, or stroma, significantly influences the biological properties of the tumor through intercellular interactions. In this thesis I have focused on the study of tumor-associated fibroblasts in squamous cell carcinomas of the head and neck, malignant melanoma and glioblastoma. The data show the presence of cells with mesenchymal characteristics, present even in the glioblastoma stroma, which could potentially have a positive effect on proliferative activity and invasiveness of glioblastoma cells. In malignant melanoma, the presence of keratinocytes should also be considered, as they are the major cells of the epidermis influencing tumor melanocytes. The conditioned medium from UVB irradiated keratinocytes and non-irradiated fibroblasts stimulates the invasion of malignant melanoma cells. Targeting the tumor stroma may be a new direction in oncological therapy, so we have focused on the influence of synthetic polyamine on the formation of myofibroblasts, which are an active part of the population of tumor-associated fibroblasts. The tested polyamine prevents the formation of myofibroblasts but has no effect on those already formed nor on...

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