It has become increasingly clear that tumor microenvironment plays a critical role in carcinogenesis. Accumulation of genetic alterations is typical not only for cancer epithelial cells but tumor-associated fibroblasts as well. Tumor epithelia, tumor-associated stroma from prostatectomy specimens of patients with prostate cancer and cells from prostatic intraepithelial neoplasia (PIN) and adjacent stroma from males with PIN were isolated by using laser capture microdissection. Microsatellite allelotyping was evaluated using 4 highly polymorphic markers for chromosomal regions 8p22, 16q23-24 and 13q14. Incidences of alterations (loss of heterozygosity or allelic imbalance) were 48% for region 8p22, 72% for 16q23 and 37% for 13q14. The LOH frequencies in tumor-associated stroma cells were very similar. Alterations at chromosome 13q were significantly associated with advanced tumor stage, whereas AI at 16q was also associated with high Gleason score and lymph node metastasis. We find some incidences of allelic imbalance in premalignant lesions in epithelial (16-27%) and stromal (7-22%) components. Our results show that the frequencies of genetic aberrations are as high in stromal cells as in tumor cells.

Renal cell carcinoma is the most common variant of the kidney cancer, which accounts approximately 75% patients with this disease. The majority of those tumors are characterized by inactivation of the VHL gene suppressor as a result of mutations, allelic deletions and/or methylation. We have conducted the complex molecular-genetic analysis of 64 samples obtained from patients with the clear cell renal cancer. VHL mutations were detected by single strand conformation polymorphism and subsequent sequencing, loss of heterozygosity was analyzed using two STR-markers, methylation was tested by methylsensitive polymerase chain reaction. All revealed variations were statistically analyzed in respect to the parameters of primary tumors in various groups of patients. Seventeen VHL somatic mutations were detected, 12 from which were described for the first time. Allelic deletions of VHL were found in 31.6%, and methylation--in 7.8% samples of the renal cancer. As a whole, VHL inactivating events were presented in 46.9% cases of disease, in 51.7% -among renal cancer patients with first stage. We have not observed any association of mutations, loss of heterozygosity and methylation with clinical-pathological parameters of disease. Results of this investigation specify for expediency of further studies of molecular genetics aberrations in the VHL gene. Perhaps, it would promote renal cancer molecular markers evaluation, for example, a determination of suppressor genes methylated in renal cancer.

Peculiarities of the incidence and spread of main non-infectious diseases (MNID) are in one or another way connected with the conception of "normal" and "successful" aging. The age-related increase in the frequency of MNID, associated with estrogen deficiency or excess, can be explained by the presence of estrogen effect switching phenomenon. The increase in the genotoxic effect of estrogens, isolated or combined with the weakening of the hormonal effect, can worsen the clinical course of MNID (including malignant tumors of hormone-dependent tissues). The effects of two other endocrine-genotoxic switchings (the joker function of glucose and adipogenotoxicosis) may realize in the same direction. The three mentioned phenomena form the so called basic triad, separate elements of which can interact. Endocrine-genotoxic switchings and their inductors are targets for prophylactic measures and, possibly, therapeutic ones. Both approaches may be divided into several groups with different points of application, whereas their ultimate goal is optimal balance between hormonal and DNA-damaging effects of estrogens, glucose, and adipose tissue-associated factors.

Poly(ADP-ribose) polymerases (PARP) is enzyme family repairing single or double DNA strand breaks induced by different alkylating agents, ionizing- or UV-irradiation as well as by oxidative stress. Poly(ADP-ribose) polymerase-1 (PARP-1) is the most studied enzyme involved in a number of pathways including DNA replication and repair, recombination, gene transcription, cell proliferation and death. A positive correlation between the PARP-activity and the life span of different mammalians has been detected. PARP inhibition in vitro with inhibitors of PARP activity (3-aminobenzamide, nicotinamide, picolinamide e.t.c.) in cells from wild type or PARP-1(-/-) mice was followed by high genomic instability (i.e. aneuploidy, gene amplifications and deletions, micronuclei formation, sister chromatic exchange, cell ploidy and centrosome number increase) and increased sensitivity to mutagens. Life span reduction, latency period of spontaneous tumors development shortening and the increase in susceptibility to carcinogens have been observed in PARP-knockout mice. Treatment with PARP inhibitors stimulated chemical and radiation carcinogenesis in animals. The PARP-1(-/-) mice being additionally disrupted in WRN, p53, DNA-PKcs or Ku80 genes the promotion of spontaneous carcinogenesis was observed as compared with a single gene-disrupted mice. Available data suggest a significant role of PARP in maintenance of genomic stability, preventing of aging and carcinogenesis.

Meningiomas of the sphenoid wing (SW) frequently show an invasive pattern of growth and cause destruction of the adjacent structures. As a result, the rate of recurrent SW meningiomas is as high as 30%. Cytogenetic investigations showed no aberrations specific to invasively growing meningiomas. During this study, the authors evaluated 10 invasive and 5 non-invasive SW meningiomas via comparative genome hybridization (CGH) (matrix CGH), by using the gene chips of GenoSensor Array micromatrixes. The mean number of aberrations in the tumor cells was much greater in case of invasive meningiomas (67.4 versus 40.5 in case of non-invasive SW meningiomas. Furthermore, in invasive SW meningiomas, there were frequently losses in loci 1p, 6q, and 14q and gains in loci 15q and 10, which had been predetermined as molecular markers of stepwise progression of meningioma. Thus, the presence of a complex cytogenetic profile and progression-associated chromosome aberrations in benign SW meningiomas is linked with the increase of their invasive potential. Due to the fact that there are no well-defined adjuvant therapy regimens for recurring meningiomas at present, the revealed genomic aberrations may become potential targets for searching for drugs and a therapeutic intervention in future.

The incidence of mutations in the BRCA1 and BRCA2 genes in the studied sampling of 74 patients with ovarian cancer was 19%. The incidence of mutations in the Russian sampling of patients, formed without consideration for the family history, is one of the highest in European countries. Retrospective analysis showed that 9% patients carrying mutation had no family history of ovarian or breast cancer. The majority of mutations (86%) were detected in BRCA1 gene, where 5382insC mutation predominated (58%). These data suggest the possibility and advisability of screening for mutations in the BRCA1/2 genes in patients with ovarian cancer, particularly because this population includes patients without family history of ovarian and/or breast cancer.

Genomic DNA methylation pattern (methylome) represents epigenetic program of a cell. It controls expression of genetic information. In tumor cells, significant alterations in DNA methylation take place, which can be identified as one of the earliest and most consistent features of tumorigenesis. Detailed survey of methylcytosines' distribution in genome is extremely important for understanding of real tumor etiology and early diagnostics. Progress in the field has been hampered by the unavailability of methods for large-scale determination of methylation patterns. Nowadays, variety of techniques is in development that allow for highly parallel regime of samples analysis (high-throughput analysis) or large loci DNA profiling (large-scale analysis). Aim of the work is to consider the main trends in the field of new methods development. The principles of the most frequently used approaches to DNA methylation studies are reviewed as well as their application and results. Most attention is paid to DNA microarrays as a technology of choice for epigenetic tumor analysis (oligonucleotide microarrays, BAC-arrays etc.). Alternative DNA sequencing based techniques are discussed, which can soon take on the leadership. Results of a large-scale analysis can be used for identification of new epigenetic markers and epigenetic classification of neoplasia.

This study involved 525 breast cancer (BC) patients of T2-4N0-2M0 stages at the age of 35 years and older. Significant differences in clinical and pathological characteristics between premenopausal and postmenopausal BC patients were found. Mostly marked differences were shown for positive lymph node correlation with distant metastasis, multicentric growth and local recurrence depending on menopause status. The prevalence of various morphological structures in primary tumors was appeared to be associated with different forms of tumor progression in pre- and postmenopausal women. We have studied polymorphisms in 15 genes involved in major cancer related pathways (apoptosis, interleukins, folate metabolism enzymes genes). We found that variant genotypes of MTHFR and DHFR genes were associated with an increased BC risk among premenopausal women while polymorphism in IL-18, p53 genes were associated with BC among postmenopausal women. These results demonstrate novel biological information, which points the different mechanisms contributed to breast cancer progression in premenopausal and postmenopausal women.

The KLRB1 gene encodes the CD161 receptor of natural killer cells (NK-cells). The gene is also expressed in the NKT-cells. The two cell types are cytotoxic and capable of recognizing and eliminating various cell species, e.g. tumorous, virus-infected, and allotransplants. The biological function of human CD161 is still insufficiently understood; probably it is involved in regulation of the cytotoxic functions of the cells and in regulation of cytokine production. Because immune system, in particular, the activity of cytotoxic cells, is suppressed in most cancer patients, it was suggested that the KLRB1 expression might be suppressed in cancerous cells. The results of this work demonstrated that the transcription of the KLRB1 was suppressed in tumor tissues in 68% patients with nonsmall-lung-cancer (p < 0.0001) and 57% patients with esophageal squamous-cell carcinoma (p = 0.0003). High frequency of the KLRB1 transcription suppression upon cancers makes it possible to use this parameter as a highly informative marker of lung and esophageal cancers.

The rate of DNA and protein biosynthesis in murine hepatoma HA-1 was accelerated when steroid hormones, containing a reduced delta4,3-keto group in the A-ring, were used in combination with apolipoprotein A-1. That was demonstrated for apolipoprotein A-1 complexes with dehydroepiandrosterone, dehydroepiandrosterone sulfate and tetrahydrocortisol. Apolipoprotein A-1 complexes serve as a vehicle for steroids penetration into cells to influence protein biosynthesis.

Specimens of tumor with K-RAS mutations were used to compare SSCP and NIRCA efficiencies in screening long target regions for dispersed point mutations. K-RAS mutations were detected in 5 out of 10 tumor tissue samples from colorectal cancer patients (in codon 12-4 and codon 13-1). Mutant alleles occurred most frequently in adenocarcinoma of the ascending colon and rectum. Both methods proved equally efficient. In certain situations, they may be combined or used as complementary. NIRCA is suitable for screening relatively long sequences (up to 1kb) while SSCP is less sophisticated, robust and allows for mutant bands to be extracted from polyacrylamide gel when required.

A new method of evaluation of immunohistochemical markers of cellular cycle (K-67, topoisomerase-II-alpha, P21/wafl), adhesion molecules (E-cadherin, CD33v6), oncoprotein HER-2, and estrogen and progesterone receptors of tumor is presented. High-precision count of tumor cells, which express each marker, was carried out using serial paraffin sections and Leica CTR5000 morphometric station and Leica Quin Plus program, to identify tumor sensitivity to anthracyclines and taxanes. Proliferative potential, tumor sensitivity to key chemical drugs and prognosis were evaluated on the basis of the evidence obtained and, in particular, the role of the proteins under study played in cellular cycle.

Breast cancer course may be influenced by a profile of steroids and peptides produced by mammary fat. The study was concerned with assessment of hormonal (leptin and adiponectin production, adipocyte diameter and aromatase level) and progenotoxic factors which characterize DNA damage (8-OHdG) and such cancer promoters as tumor necrosis (TNF-alpha), interleukin-6 (IL-6), nitric oxide (NO), thiobarbiturate reactive products (TRP), macrophage/histiocyte infiltration, estrogen 4-hydroxylase expression (CYP1B1) in mammary fat located 1.5-2 cm or not less than 5 cm away from tumor edge. Thirty-three pairs of mammary fat samples from 23 menopausal and 10 cycling patients were used. Closer proximity of mammary fat involved intensified biosynthesis of estrogens (as shown by aromatase level) and their conversion to catechol derivatives (as shown by CYP1B1 concentration) as well as accumulation of 8-OH-dG. Smoking and hyperglycemic patients and those with considerable mammary fat volume revealed accumulations of anti-inflammatory and progenotoxic cytokines (IL-6 or TNF-alpha). Hence, hormonal/progenotoxic ratio in mammary fat can be identified both by topographic, systemic and environmental factors.

Earlier the authors demonstrated that the process of tumor progression in vivo may be inhibited or accelerated depending on the conditions of tumor growth (accelerated by tumor cell dissemination or delayed in locally growing tumors). It was also shown that tumor progression is inhibited in case of bcl-2 gene transduction in tumor cells. In this study, the research into mechanisms of the acceleration or inhibition of tumor progression and the role that Bcl-2 family proteins may play in these phenomena was continued. The results of the study demonstrated the following 1) immediate in vivo activation of endogenous proapoptotic Bax protein in disseminated tumor cells, not protected by Bcl-2 against apoptosis, and its correlation with accelerated tumor progression; 2) complete suppression of in vivo Bax activation in tumor cells protected by Bcl-expression, and inhibited tumor progression; 3) alternative character of Bcl-2 and Bax expression under the conditions of accelerated and inhibited tumor progression. Thus, the data presented support the hypothesis that the rates of tumor progression in vivo are regulated depending on the initial anti- and proapoptotic programs of tumor cells.

The correlation between DRB1, DQA1, and DQB1 genes of HLA class II, and the development of germ cell tumors (GCTs), as well as serological response to HERV-K proteins were investigated. Genomic DNA prepared from 99 GST patients was subjected to HLA typing by polymerase chain reaction (PCR) using the set of sequence specific primers (PCR-SSP). This set of primers made it possible to detect 14 specificities of DRB 1 locus, 12 alleles and groups of alleles of DQB 1 locus, and 8 alleles of DQA1 locus. Alongside with the definition of the occurrence of HLA markers in the total group of patients, the frequency of the occurrence of HLA-DR-DQ alleles was calculated in: 1) patients with different morphological forms of GSTs (seminomas and non-seminomas); 2) GCT patients producing or non-producing antibodies to Gag and/or Env HERV-K proteins. The comparison group consisted of 300 Moscow blood donors. The study did not reveal statistically significant differences in the frequency of the occurrence of DRB1, DQA1, and DQB1 alleles between the total group of GCT patients, its subgroup, and the control group. Thus, the data obtained demonstrated the absence of a strict correlation between the distribution of HLA class II alleles and GCT occurrence in the Russian population, as well as the ability of GCT patients to develop an antibody to HERV-K proteins, though more numerous observations are required to confirm this conclusion.

Infection with high risk papilloma viruses (HPV types 16, 18, and relative ones) initiates the development and progression of uterine neck cancer. The viral genome is found in pre-tumorous lesions (stage I to III intraepithelial neoplasias--CIN) and carcinomas, persisting in cells in episomal or integrated state. In all tumors, there is the expression of two viral transforming genes, E6 and E7, the main function of which is the inactivation of genes that suppress tumoral growth, p53 and retinoblastoma gene. In CIN and carcinomas, losses of heterozygosity are found in various chromosomes, mainly in the areas of suppressor genes; some of them can be specific for certain stages of the malignant process. Among epigenetic alterations, the main significance for the progress of the disease belongs to the methylation of the promoter areas of the genes involved in the process of cell division, which may be specific for each separate tumor and appears in approximately 30 to 40% of tumors. Another important epigenetic alteration is the increase in the expression of p16ink4a gene, which is the inhibitor of cyclin-dependent kinases; this appears at CIN I stage and may serve as an additional early diagnostic marker. Telomerase activity has been identified in all uterine neck tumors, but each tumor has its own spectrum of spliced RNA coding this enzyme. Expression microchip technique has shown that each tumor is individual according to the spectrum of "working" genes, and this spectrum varies in the process of tumor progression.

Malignant tumor develop from cells with distorted signaling pathways controlling proliferation, migration, viability, differentiation, and genome integrity, as well as their influence on microenvironment. Progress in understanding molecular mechanisms of such alterations has led to the elaboration of new methods of anti-tumor therapy based on the modulation of the activity of molecules playing a key role in tumor development (so-called "target therapy"). The paper describes basic mechanisms of the development of cell features determining malignant phenotype and new possibilities for its correction. In particular, recent finding concerning the role of reactive oxygen species in oncogenesis and anti-tumor therapy are considered.