Human antigen GA733-1, defined as 40 kDa cell glycoprotein, is one of the antigens associated with gastrointestinal carcinomas. Its studies may contribute to the tumor etiology and therapy effects in animal model.
The purpose of this study was searching for sequences similar to bovine leukaemia virus genome in the genome of BLV-free cattle. The study was performed using PCR method and hybridisation. Products of amplification with starters specific for BLV genome was discovered. The presence of these sequences was confirmed by hybridisation with molecular probe complementary to BLV genome. It cannot be ruled out that these are endogenous sequences similar to bovine leukaemia virus in the genome of BLV-free cattle.
Expression of GA733-1 and GA733-2 genes in gastrointestinal tumours was investigated. Twelve cases of colorectal and stomach cancers were analysed. The Northern blot and RT-PCR methods were used. The second method appeared to be much more sensitive and useful in these investigations. No expression of GA733-1 gene was found in the investigated cases. GA733-2 expression was observed in 83% of colon cancers (five to six analysed cases) and in 33% of stomach cancers (two to six analysed cases). No correlation was found between the expression and clinical properties of tumours. Moreover, in two cases the presence of GA733-2 mRNA was observed in the surrounding morphologically normal tissue. These results indicate that GA733-2 gene can be a good marker of colon but not stomach cancers.
The aim of the study was to assess the expression of TNFRp55 mRNA and to examine if the antisense inhibition of Epstein-Barr virus (EBV) encoded EBNA1 gene product alters the expression of gene encoding TNFRp55 in lymphoblastoid cell line (LCL). The experiment was performed on LCL derived from EBV infected human peripheral blood B lymphocytes. The lymphocytes were isolated and cultured. RNA was isolated and examined according to the RNase protection assay. The hybridisation was done with HCR-4 probe. RNA was quantified by densitometry and presented in extinction units. The level of expression was calculated with TotalLab software programme. The results of the study suggest that EBV gene, responsible for the synthesis of EBNA1 protein, has an inhibitory effect on human TNFRp55 gene expression in LCL.
Telomeres are the end fragments of chromosomes formed by a number of non-coding double-stranded TTAGGG repeats in vertebrates. During cell division the number of repeats decreases, leading to cell senescence or apoptosis. In immortal cells, including cancer cells, the telomere length is stable and maintained by, among other factors, telomerase. The aim of the study is to compare telomerase activity in normal lymphocytes and in leukaemic cells. Samples of acute leukaemia cells, HL 60 cell line and the lymphocytes of healthy volunteers were examined. Telomerase analysis was performed using TeloTAGGG Telomerase PCR ELISAplus (Roche). The relative telomerase activities (RTA) in leukaemic and normal cells were analysed. A high level of RTA was observed in leukaemic cells.