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Comparison of sequence variations in genes of biotransfromation enzymes in some carcinoma
Turková, Lucie ; Tavandzis, Spiros (referee) ; Bóday, Arpád (advisor)
Xenobiotic biotransformation process and its capacity is crucial for xenobiotic chemicals elimination that may cause damage toward cell structures. The effectiveness of the enzymes included in this process depends on the gene variants that encodes them. The aim of this work was to compare certain polymorphisms of selected genes between cases and control groups. Studied polymorphisms were null genotypes of the glutathione S-transferase gene M1 and T1 and the insertion of TA dinucleotide in the promotor region of UDP-glucuronosyl transferase 1A1. The number of cases group was six included patients with colorectal, lung, prostate, breast, pancreatic and head and neck cancer. Total number of analysed individuals was 1 118 for cancer cases and 470 for healthy controls. The control group was divided into two groups, the first one was called general and the second one was called special included healthy individuals with no cancer history in their closest family members. Gilbert syndrome (GS) is caused by homozygous insertion of the TA dinucleotide in the TATA box of the gene UGT1A1 and it causes elevated bilirubin levels. Bilirubin is a potent antioxidant in human body, so the aim was to attest its protective effect toward cancer. We expected lower frequency of GS as a protective factor in the cases groups compared with controls. This hypothesis was confirmed in the breast cancer group (GS frequency 10,0 %) and pancreatic cancer group (GS frequency 11,1 %). In the general and special control groups the frequency of GS was 16,0 % and 15,4 % respectively. Although the other case groups show lower frequency of GS, the results weren´t statistically significant. Null GSTM1 genotype was observed with 50,4 % frequency in the general control groups and with 55,3 % frequency in the special control group. Neither the one of the cases groups hasn´t showed significantly lower percentage of null genotype. Despite expectation we observed statistically significant lower frequency of null genotype in the group of lung and pancreatic cancer group (37,4 % and 39,3 % respectively). According to this study, we can say that the lack of glutathione S-transferase M1 activity is not a risk factor for cancer development. Null genotype of GSTT1 wasn´t identified in both control groups at all. In case groups of breast and prostate cancer, there was only one individual carrying the null GSTT1 genotype. Statistically significant higher frequency of this polymorphism was observed in patients with colorectal cancer (9,7 %), lung cancer (17,2 %), pancreatic cancer (3,0 %) and head and neck cancer (15,9 %). In these groups the lack of glutathion S-transferase T1 activity might be considered as risk factor for cancer development. Nevertheless, for further verification it needs to take more investigation in this field, especially enlarge the number of patient in the case groups of head and neck, lung and pancreatic cancer.
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A DNA double-strand break repair and it's disorders with a relationship to the cancerogenesis
Komžák, Josef ; Ševčík, Jan (advisor) ; Vopálenský, Václav (referee)
The DNA-double strand break (DSB) repair has an essential importance for the genomic integrity maintenance. The main DSB repair pathways are homologous recombination (HR), non-homologous end joining (NHEJ) and single-strand annealing (SSA). The most important protein factors contributing to the maintenance of genomic integrity by direct participation in DSB repair are MRN, ATM, Rad51, BRCA1/2 and PALB2 in the case of HR; Ku70/80 DNA-PKcs, XRCC4 and DNA ligase IV in the case of NHEJ and Msh2-Msh3 and Rad1- Rad10 in the case of SSA. If mutated, these proteins can cause the inability to repair DNA lesions leading to a malignant transformation. The predominant phenotype manifestation of BRCA1/2 inactivation is the hereditary breast and/or ovarian cancer (HBOC). Mutations in ATM have been described as a cause of ataxia telangiectasia and inactivation of NBN gene (Nbs1 protein) causes the Nijmegen breakage syndrome. Other syndromes connected with defects in a DSB repair pathways are Fanconi anemia and Werner syndrome. Detail knowledge of DSB repair process is a mandatory for diagnostics and effective therapy of a number of malignances. An example of practical and clinically relevant utilization of current knowledge about the DSB repair process is the concept of a synthetic lethality as a specific therapy. This...
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From the search for new oncogenes to the effort of redefining the cancerogenesis phenomenon
Pajer, Petr ; Dvořák, Michal (advisor) ; Vodička, Pavel (referee) ; Eckschlager, Tomáš (referee)
The described experimental model of clonal tumors induced through the insertional mutagenesis with MAV-2 proved to be a valid and rich source of information describing the process of transformation of normal into tumor cell. We have mapped more than 2000 individual clonal VISs from several hundreds of tumor tissue samples. We have analyzed five tumor types of different histology and tissue of origin along with their derivative tissue cultures. Furthermore, we have discovered the industasis phenomenon and described it during the course of the study. The goal of my study was to uncover common reasons for neoplastic transformation of the cell. The results of my study led me to the paradoxical conclusion that the significance of genetic changes as the primary cause of induction of neoplastic transformation is being overestimated. Although studying the functions of individual genes and search for new tumor markers and therapeutical targets are still beneficial, I believe that the traditional perception of tumor formation as a function/result of mutation accumulation and selection is becoming a serious drawback in further investigations. These conclusions are further discussed in the last section of the presented Ph.D. thesis.
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Comparison of sequence variations in genes of biotransfromation enzymes in some carcinoma
Turková, Lucie ; Tavandzis, Spiros (referee) ; Bóday, Arpád (advisor)
Xenobiotic biotransformation process and its capacity is crucial for xenobiotic chemicals elimination that may cause damage toward cell structures. The effectiveness of the enzymes included in this process depends on the gene variants that encodes them. The aim of this work was to compare certain polymorphisms of selected genes between cases and control groups. Studied polymorphisms were null genotypes of the glutathione S-transferase gene M1 and T1 and the insertion of TA dinucleotide in the promotor region of UDP-glucuronosyl transferase 1A1. The number of cases group was six included patients with colorectal, lung, prostate, breast, pancreatic and head and neck cancer. Total number of analysed individuals was 1 118 for cancer cases and 470 for healthy controls. The control group was divided into two groups, the first one was called general and the second one was called special included healthy individuals with no cancer history in their closest family members. Gilbert syndrome (GS) is caused by homozygous insertion of the TA dinucleotide in the TATA box of the gene UGT1A1 and it causes elevated bilirubin levels. Bilirubin is a potent antioxidant in human body, so the aim was to attest its protective effect toward cancer. We expected lower frequency of GS as a protective factor in the cases groups compared with controls. This hypothesis was confirmed in the breast cancer group (GS frequency 10,0 %) and pancreatic cancer group (GS frequency 11,1 %). In the general and special control groups the frequency of GS was 16,0 % and 15,4 % respectively. Although the other case groups show lower frequency of GS, the results weren´t statistically significant. Null GSTM1 genotype was observed with 50,4 % frequency in the general control groups and with 55,3 % frequency in the special control group. Neither the one of the cases groups hasn´t showed significantly lower percentage of null genotype. Despite expectation we observed statistically significant lower frequency of null genotype in the group of lung and pancreatic cancer group (37,4 % and 39,3 % respectively). According to this study, we can say that the lack of glutathione S-transferase M1 activity is not a risk factor for cancer development. Null genotype of GSTT1 wasn´t identified in both control groups at all. In case groups of breast and prostate cancer, there was only one individual carrying the null GSTT1 genotype. Statistically significant higher frequency of this polymorphism was observed in patients with colorectal cancer (9,7 %), lung cancer (17,2 %), pancreatic cancer (3,0 %) and head and neck cancer (15,9 %). In these groups the lack of glutathion S-transferase T1 activity might be considered as risk factor for cancer development. Nevertheless, for further verification it needs to take more investigation in this field, especially enlarge the number of patient in the case groups of head and neck, lung and pancreatic cancer.
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Cell fusion and carcinogenesis
MARŠÍKOVÁ, Hana
The origin of cancer remains enigmatic. The object of this study was to find out the impact of BMDCs fusion without any carcinogens on cancer progression. The arising instability of genome could give rise to malignancy.
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