Clones of immortalized human fibroblasts with an extended life span in culture and a capability of subloning were obtained after the infection with a temperature sensitive mutant (tsA 239) of SV40 virus and pSV3neo plasmid. As compared with the parental cells, the obtained clones exhibited increased plating efficiency, decreased doubling time, and serum dependence. We did not obtained the colony formation during cultivation of immortalized cells in semiliquid agar. This means that our cells were not completely malignant. The PCR (polymerase chain reaction)-analysis has revealed the presence of viral DNA at early passages (25th passage) after the infection by tsA SV40, and its absence after a prolonged cultivation (46th passage). PCR-analysis of the clones obtained after pSV3neo transfection has revealed the presence of gene A sequences either at early (9-15), or later (62) passages. The expression of the gene A product in cells of these clones was revealed only early passages (11 and 35). Possible mechanisms of immortal phenotype origin in human diploid cells after the action of ts-mutant and other constructions of SV40 are discussed.

HpaII/MspI blot-hybridization analysis of the 5'-end region of the calcitonin (CT) gene methylation in cells of bone marrow and peripheral blood of patients with acute lymphoblastic leukemias (ALL) has been carried out. ALLs are accompanied by hypermethylation of the inner cytosine in the CCGG sequences of this region of the CT gene. The level of hypermethylation of the CT gene corresponded to the degree of disease progression and malignancy. At a long-term remission, hypermethylation of the CT gene is not observed. In case of primary resistance or if the complete remission has not been achieved the CT gene remained hypermethylated. It has been shown that in relapse the normal CT gene methylation pattern reversed to hypermethylation. This phenomenon was detected 1-8 months before the obvious clinical and laboratory signs of the disease progression (relapse). The large size of abnormal HpaII-fragments of the 5'-end region of the calcitonin gene had a direct correlation with the malignancy status of ALL.

PCR-based typing of Hras1 minisatellite alleles was carried out in 226 non-small cell lung cancer (NSCLC) patients and 207 unaffected controls. Application of this method permitted detection of four common (a1 to a4) and 25 other alleles, differing from any common allele by one or more repeat units. Depending on their frequency in control group, these alleles were defined as intermediate or rare (the frequency over 0.5% or less than 0.5%, respectively). It was established that the frequency of rare alleles in the group of NSCLC patients (7.1%) was statistically significantly higher than in healthy individuals (2.2%, p = 0.002), while the difference in the distribution of common and intermediate alleles between the compared groups was not statistically significant. In addition, rare Hras1 alleles were more frequent (p = 0.02) among nonsmoking patients compared to the patients subjected to of tobacco carcinogens. The presence of "heavy" (a3-a4) alleles was associated with an increased risk of low-differentiated and/or actively metastasizing tumors and also with the risk of lung cancer in the patients under 50 years of age (p < 0.05). These data indicate that an approach including application of modern highly sensitive techniques of Hras1 allele typing in combination with preliminary examination of healthy control population can be employed for identifying carcinogenic risk groups as well as for prognosis of the NSCLC clinical course.

The presented study is devoted to investigation of molecular mechanisms regulating alpha-fetoprotein (AFP) gene expression at transcriptional level. The study was carried out on AFP-positive and AFP-negative clones of rat hepatoma McA-RH 7777 that also differ in hepatocyte nuclear factors (HNF) 1 and 4 transcription levels. To examine a hypothesis of existence in AFP-non-producing clones a transcriptional factor that downregulates this gene expression, we have obtained somatic hybrids of AFP-positive and AFP-negative clones. In the obtained hybrids AFP gene expression is decreased while expression of HNF1, one of the main AFP promoter activators, is maintained. These data indicate an existence of a repressor in AFP-negative clones that determines AFP gene downregulation regardless of the HNF1 expression level.

The recent data on the phenomenon of the induced germline genomic instability at mini- and microsatellites in animals were considered. Natural hypervariability of the minisatellites and microsatellites and their abundance in eukaryotic genome provide it's utility as the useful genetic markers for evaluation of the germline mutation frequency induced by treatment with different type of genotoxic factors at the low doses. High sensitivity of assays and possibility for direct determinations of the mutations, without the necessity to use extrapolation, are ensured. Some discussion is presented on the role of non-targeted mechanisms for the radiation-prone DNA lesions in the induction of germline genomic instability and also on the involving in this process the recombination events upon meiosis or during the early development stages of embryos. It is proposed that quantitative determination of germline genomic instability rate may be used as an acceptable variant for the genetic risk assessment and as indicator of increased probability for cancer and other pathologies at the offspring born to irradiated parents.

The heterogeneity of hepatoma MH-22a cell line was studied by clonal analysis on the basis of the following factors: splenocyte-induced apoptosis of tumor hepatocytes, tumor hepatocyte-induced apoptosis of splenocytes and profile of B1-associated DNA fragments. Induction of apoptosis of tumor hepatocytes by splenocytes and of splenocytes--by tumor hepatocytes was carried out in the main population of hepatocytes and in five clonal lines of hepatoma MH-22a. Genetic heterogeneity was studied using the same material and PCR primed for murine B1-elements. It was shown that apoptosis of hepatocytes of the main population and two clonal lines of hepatoma MH-22a was induced by splenocytes. The ability to induce apoptosis of splenocytes was observed in the same clonal lines and population of tumor hepatocytes. The latter involved enhanced genetic heterogeneity which was identified by B1-PCR analysis. Thus, a correlation was established in tumor hepatocytes between apoptosis-related characteristics and frequency of genome rearrangements.

The mechanisms of possible cytoskeletal reorganizations leading to morphological transformations of cells of two types, epitheliocytes and fibroblasts, are discussed. It is suggested that the non-transformed cells of these types can exist in two morphological forms, sedentary and migratory, and that genetic changes occurring with carcinogenesis block the ability of cells to undergo transitions from the sedentary form to the migratory one.

The paper presents recent data on the role of oncogenes and suppressive genes, receptors of steroidal hormones, secretory protein pS2, cathepsin D, urokinase and tissue plasminogen activators and their inhibitor PAI-I, polypeptide growth factors and somatostatin and their receptors in the evaluation of proliferative activity and drug therapy responses and in the prediction of disease and on the simultaneous estimation of the limited number of mutually complementing parameters that can characterize the proliferative activity of a tumor, its metastatic potential and sensitivity to different types of overall and regional regulation. The main task for investigators engaged in this area is to choose a qualitatively and quantitatively optimal ratio of molecular markers of breast cancer to evaluate the biological behavior of a tumor.

The paper deals with a role of inherited factors responsible for the occurrence of malignant tumors. Inherited types of cancer are shown to occur virtually at its sites and averaged 5-15%. Formalized criteria for identifying inherited cancer diseases and their etiological and genetic heterogeneity are presented. A role of genes that genetically predispose to particular forms of cancer is shown, which allows for early (preclinical) diagnosis and prevention of cancer diseases.

Vaccination with autologous cancer cells expressing a potent foreign antigen is promising for immunotherapy of tumors. A construct was obtained to transfect cancer cells with the hemagglutinin-neuraminidase (HN) gene of the Newcastle disease virus (NDV). Specific primers were designed, and the HN cDNA was amplified from RNA isolated from the allantoid fluid of NDV-infected embryonated chicken eggs. The amplified fragment was cloned in pCR2.1, sequenced, and recloned in expression vector pCDNA3.1/Zeo(+). The resulting construct was used to transfect mouse myeloma cells SP2/0. Production of HN was checked by ELISA and by a neuraminidase activity assay. Cell agglutination on ice was proposed as a test for surface HN.

Since deletions of the short arm of chromosome 17 are the most common genetic defects in human colorectal carcinoma (CC), we tested the YNZ22 locus (D17S30, 17p13.3) for loss of heterozygosity (LH) in adenocarcinoma and in the normal colonic mucosa of 49 CC patients, and studied the association of LH with clinicomorphological features of the tumor. Allele frequency distribution of YNZ22 did not differ for the patients and healthy people. LH in YNZ22 in the tumor was found in 33% (13/39) of all informative cases, its frequency being thrice higher in men than in women (chi 2 = 5.21, p = 0.022). The defect was associated with moderate or poor histological differentiation (P2 = 0.0055) and polyploidy > 3n (P2 = 0.0035) of tumor cells and with high incidence of post-surgery relapse or metastasis. Analysis of both YNZ22 and Alu-VpA/MycL1 (1p34.3) loci in the tumor allowed reliable relapse prognosis in 76% of the CC patients. The probability of post-surgery relapse or metastasis was estimated at no less than 67% for patients with LH in at least one of the two loci in the tumor, and at somewhat more than 20% for patients without LH.

Complex clinic-genealogical and genetic-mathematical investigation of 482 patients with uterus cancer from Chernovtsy region was carried out. It was proved that primary in the population is multifactoral origin of uterus cancer. Percentage of genetic component in general susceptibility to disease was 11.40 9.40. Recurrent risk of the malignant tumor in progeny has been estimated. Results of the investigation are the base for development and execution of uterus cancer precaution and segregated with it oncopathology in proband relatives.

The study of the prognostic criteria of hormone-resistant prostatic cancer (PC) by specifying expression of androgen receptor protein as well as Bcl-2 and p53 proteins, apoptosis regulators, has demonstrated that tumor cells of hormone-sensitive and hormone-resistant PC forms have different variants of immunophenotype. Hormone-resistance is typical for tumors from urothelial, basal and neuroendocrine PC cells, glandular epithelium cells which lost androgen receptors (AR) and tumors consisting of cells which retain AR but simultaneously express Bcl-2 and/or p53 genes. The discovery of androgen-resistant cancer from glandular epithelium which has immunophenotype characteristics of a hormone-dependent tumor indicates the existence of other mechanisms of protection against apoptosis. The development of hormone-resistant cancer 2.5-3 years after hormonal therapy is associated with changes in immunophenotype of tumor cells. They become Bcl-2- and/or p53-positive while part of them lose AR. Thus, immunophenotype of tumor cells may serve a prognostic marker of hormonal resistance of the tumor and dictate the treatment policy.