|
|
Spontaneous Regression of Melanoma in Pigs of the MeLiM Strain
Plánská, Daniela
Melanoma is a skin tumour arising from melanocytes - skin cells bearing pigment melanin. Melanoma belongs among immunogenic tumours, which is probably associated with a relatively high incidence of partial spontaneous regression (SR). Melanoma-bearing Libechov Minipigs (MeLiM) represent a specially bred animal model that is mostly affected by nodular melanomas, which fully regressed in about 2/3 of the affected animals. Our interest was to examine immune response (associated with melanoma cell destruction) and the role of proteins related to the extracellular matrix (reflecting tissue remodeling) during SR of MeLiM melanoma. We performed an extensive time-lapse study of skin melanomas taken from individuals of the MeLiM strain at 3, 4, 6, 8, 10, 12, 20 and 32 weeks (5-10 samples in each age category) in which we immunohistochemically detected the expression of collagen IV, laminin, fibronectin, tenascin C, as well as MMP-2 and we monitored the proportion of basic immune subpopulations in blood and tumour by flow cytometry. The higher expression of collagen IV, laminin and MMP-2 positively correlated with the appearance of melanoma cells. The expression of collagen IV and laminin indicates a possible survival of tumour cells due to the interaction with these proteins, the presence of MMP-2 in these...
|
|
|
Spontaneous Regression of Melanoma in Pigs of the MeLiM Strain
Plánská, Daniela ; Horák, Vratislav (advisor) ; Smetana, Karel (referee) ; Bartůňková, Jiřina (referee)
Melanoma is a skin tumour arising from melanocytes - skin cells bearing pigment melanin. Melanoma belongs among immunogenic tumours, which is probably associated with a relatively high incidence of partial spontaneous regression (SR). Melanoma-bearing Libechov Minipigs (MeLiM) represent a specially bred animal model that is mostly affected by nodular melanomas, which fully regressed in about 2/3 of the affected animals. Our interest was to examine immune response (associated with melanoma cell destruction) and the role of proteins related to the extracellular matrix (reflecting tissue remodeling) during SR of MeLiM melanoma. We performed an extensive time-lapse study of skin melanomas taken from individuals of the MeLiM strain at 3, 4, 6, 8, 10, 12, 20 and 32 weeks (5-10 samples in each age category) in which we immunohistochemically detected the expression of collagen IV, laminin, fibronectin, tenascin C, as well as MMP-2 and we monitored the proportion of basic immune subpopulations in blood and tumour by flow cytometry. The higher expression of collagen IV, laminin and MMP-2 positively correlated with the appearance of melanoma cells. The expression of collagen IV and laminin indicates a possible survival of tumour cells due to the interaction with these proteins, the presence of MMP-2 in these...
|
|
|
Cytokine expression in regressive melanoma on porcine MeLiM model
Miltrová, Veronika ; Skalníková, Helena (advisor) ; Krulová, Magdaléna (referee)
Cutaneous melanoma is a very aggressive cancer with increasing incidence. It originates from transformed pigmented skin cells (melanocytes). The main risk factor for melanoma development is exposure to UV light and repeated sunburns. In approximately 10 % of cases, melanoma occurs on hereditary basis. Patients with cutaneous melanoma diagnosed in early stages have very good prognosis, with surgical resection of the primary tumour being mostly sufficient for treatment. In contrast, the advanced melanoma stages with metastases are often progressive and refractory to conventional therapies. Cutaneous melanoma is referred to as an immunogenic tumour that is frequently infiltrated by cells of the immune system. Tumours with immune cell infiltration show better prognosis. Spontaneous regression may occur. Over the last few years, progress has been made in the treatment of melanoma using checkpoints molecules (anti-CTLA-4 and anti-PD-1) to activate patients own immune system to recognize tumour lesions. In the tumour microenvironment, cytokines play an important role, enabling communication between cells and regulation of cell proliferation and migration and thus the tumour development. Cytokines (IL-2, IFNα) can be used in adjuvant therapy of melanoma. This work analysed levels of expressed cytokines in...
|
|
|
Examination of the Spatial Structure of Pigs' Melanoma in Tissue Sections Based on Histology and Mass Spectrometry
Anýz, J. ; Vysloužilová, L. ; Horák, Vratislav ; Štěpánková, O. ; Vaculovič, T. ; Adam, V.
We examine the spatial structure of the melanoma in tissue sections. The pigs melanoma was examined in 10 tissue samples obtained from animals of age between 4 and 22 weeks. The tissue sections were measured by light microscopy and Laser Ablation Ion Inductively Coupled Plasma Mass Spectrometry to obtain spatial metal (Cu, Zn) distribution. The exploratory analysis of the tissue sections indicates there is clearly a pattern in the spatial structure. Different projections of the spatial structure of the melanoma are obtained by the different measurement methods. The spectral clustering on the data was utilized to describe the structure in the data. According to the clustering results, there are distinct clusters of observations in the histological data. The spatial elemental distribution of the metals Cu and Zn cannot be clustered -the data form one compact cluster. The clustering of the histological images produces clusters which are related to the annotation of the biological samples in broader terms -the differences between fibrous and cancerous tissue.
|
|
|
Changes in functional morphology of reproductive organs in MeLiM sows
Strnadová, Kristýna ; Chmelíková, Eva (advisor) ; Vilma, Vilma (referee)
A melanoma is a tumor disease, which can attack besides the skin also other organs, for example eye, gastrointestinal and urogenital tract. Aggressive progression and therapy resistance are characteristic for the melanoma. There is a continuous growth of the incidence of this disease in the world. That is one of the reasons why there is a growth in number
of studies conducted on animal models, which are affected by this disease. MeLiM (Melanoma-bearing Libechov Minipigs) is great example of suitable animal model
for studying this tumor disease. In these pigs occurs a hereditary melanoma. The peculiarity of this pig strain is, that there is described a complete spontaneous tumor regression usually within three months after birth. Complete spontaneous tumor regression is very rare
in humans. However, there were discovered similarities between melanoma occurring in this pig strain and melanoma affecting humans in biochemistry and histopathology. The animal model MeLiM is very suitable for tumor disease research because of these similarities.
Reproduction in the animal model MeLiM is not well understood. It can be assumed, in the MeLiM strain sows with hereditary melanoma occurs changes in the functional morphology of the reproductive organs and there are abnormalities in meiotic maturation
of oocytes. The aim of this study was to determine if there are changes in the functional morphology of the reproductive organs in the MeLiM strain sows and if there
are abnormalities in meiotic maturation of oocytes.
We confirmed in our study that the reproductive organs in MeLiM strain sows
are smaller than the reproductive organs in common strain of pigs described
in the publications. On the ovary of sows were observed ovarian cysts, but there were
no abnormalities in meiotic maturation of MeLiM oocytes, even when the number of oocytes was smaller.
|
guest ::
