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Germline mutations of BRCA1/2 genes cause the predisposition of their carriers to breast or/and ovary cancers (BC or/and OC) during the lifetime. Identification of these mutations is a basis of molecular diagnosis for BC susceptibility. Rapid genotyping technique using microarrays for identification of BRCA1 185delAG, 300T>G, 4153delA, 5382insC mutations and 4158 A>G sequence variant; BRCA2 695insT and 6174delT mutations; 1100delC mutation in CHEK2 gene was applied for 412 randomly collected breast cancer samples from the central region of European area of Russia. In 25 (6.0%) patients (6.0%) BC was associated with other tumours: OC, cervical cancer, colorectal cancer etc. BRCA1/2 and CHEK2 mutations were found in 33 (8.0%) BC patients. The most frequent mutation was BRCA1 5382insC, occurred in 16 (3.9%) BC patients, and CHEK2 1100delC, revealed in 7 (1.7%) BC patients. An application of diagnostic BC-microarray for genetic testing of BRCA1/2 and CHEK2 founder mutations has been discussed.

Germline mutations of BRCA1/2 genes cause the predisposition of their carriers to breast or/and ovary cancers (BC or/and OC) during the lifetime. Identification of these mutations is a basis of molecular diagnosis for BC susceptibility. Rapid genotyping technique using microarrays for identification of BRCA1 185delAG, 300TG, 4153delA, 5382insC mutations and 4158 AG sequence variant; BRCA2 695insT and 6174delT mutations; 1100delC mutation in CHEK2 gene was applied for 412 randomly collected breast cancer samples from the central region of European area of Russia. In 25 (6.0%) patients (6.0%) BC was associated with other tumours: OC, cervical cancer, colorectal cancer etc. BRCA1/2 and CHEK2 mutations were found in 33 (8.0%) BC patients. The most frequent mutation was BRCA1 5382insC, occurred in 16 (3.9%) BC patients, and CHEK2 1100delC, revealed in 7 (1.7%) BC patients. An application of diagnostic BC-microarray for genetic testing of BRCA1/2 and CHEK2 founder mutations has been discussed.

State Research Center "GosNIIgenetika", Moscow, 117545 Russia). Association of polymorphic markers Arg72Pro of TP53 gene and T309G of MDM2 gene with risk of non small cell lung cancer has been studied in Russians of Moscow region. We found an association of minor Pro/Pro genotype of polymorphic marker Arg72Pro (OR = 5.46, p = 8 x 10(-6)) and TG genotype of polymorphic marker T309G (OR = 5.57, p = 0.007) with non small cell lung cancer development. We have also showed a strong association of both Pro/Pro and TG genotypes with development of adenocarcinoma (OR = 8.71, p = 3 x 10(-6) and OR = 8.13, p = 0.003) and squamous-cell lung cancer (OR = 4.2, p = 0.001 and OR = 7.02, p = 0.002). We have finally found highly reliable association of combined susceptible genotypes of polymorphic markers Arg72Pro and T309G of TP53 and MDM2 genes with non small cell lung cancer and both its subtypes (OR = 7.9, p = 0.01; OR = 9.12,p = 0.02; OR = 7.31, p = 0.03, respectively).

To determine the genetic forms of follicular cell thyroid carcinoma (FCTC) (papillary and follicular thyroid carcinoma (PTC and FTC)), to identify criteria to individually predict the development of the same disease for relatives, and to assess the role of molecular markers in the diagnosis, prognosis, and treatment of this disease.One hundred and ninety adult patients aged 20 to 84 years with histologically verified PTC and FTC and 20 children (12 patients with PTC and 8 with benign thyroid tumors) aged 2 to 16 years were examined. To assess the role of the BRAF gene as a molecular marker for thyroid carcinoma, DNA was isolated from the thyroid tumor tissue of 29 patients, which had been obtained by fine-needle aspiration biopsy (FNAB) and scraping and swabbing the cytological specimen previously showing an area containing tumor cells. A BRAF c.1799TA (p.V600E) mutation in the FNAB specimens was tested by allele-specific ligation, followed by PCR amplification.The examinees' families were found to have a segregation of benign thyroid tumor and nontumor diseases (13.6%). Neoplasias of different sites were observed in 15% of the patients' relatives. Multiple primary tumors were detected in 6.1% of the patients and in 25% of the examined children (3/12). PTC was ascertained to accumulate as two clinical forms in the families. One form belongs to familial PTC (FPTC) in which two or three generations of relatives in the family are afflicted by only PTC and have a more severe phenotype of the disease. The other includes an association of FPTC with papillary kidney cancer. Furthermore, FPTC and PTC may be a component of multitumor syndromes, such as multiple endocrine neoplasia type 1, Cowden syndrome, and familial adenomatous polyposis. The familial hereditary forms of FCTC were generally revealed in 4.2% of the patients. BRAF v600E mutations were found in only 3 patients with Stages II and III PTC and were not in all the 12 children with PTC.The found clinical manifestation of the hereditary forms of FCTC permits the identification of people at high risk for this disease. No correlation between somatic BRAF mutations with a less favorable course in PTC can be noticed because there are few observations. Analysis of published data on the role of molecular markers in FCTC has shown that the existing specific somatic changes complement information in the differential cytological diagnosis when examining FNAB specimens.

A 5-year survival of patients with Stage III colon cancer with prophylactic panhysterectomy in anamnesis was 83.3%, significantly higher than that of patients with Stage III colon cancer without panhysterectomy (69.3%) and than in colon cancer patients with metachronous ovarian metastases (42%). In families of patients with primary multiple malignant tumors (PMMT) of colon, endometrium and/or ovaries as well as in cases of accumulation in the same family of solitary tumors of the above locations it is necessary to carry out genetic testing to identify mutations in genes MSH2, MLH1, MSH6. Carriers of mutations in genes of mismatch repair MSH2, MLH1, MSH6 should be assumed to the high-risk group for the development of malignancies both PMMT of colon and organs of the female reproductive system and solitary tumors of the above locations. All women suffering from colon cancer, especially in the presence of mutations in genes of mismatch repair, in pre- and menopause should be undergone simultaneous prophylactic surgery: panhysterectomy. The question about the greater omentum should be decided situationally.

MicroRNA regulates gene expression, is involved in many cellular processes, and plays an important role in the development of cancer. The regulation of the expression of miRNA genes can be achieved by methylating their CpG islands, which is shown in different types of tumors. The methylation of miRNA genes in clear cell renal cell carcinoma (CCRCC) has mainly been studied for the miR-9 and miR-34 families. The methylation of six miRNA genes (miR-124a-2, -124a-3, -9-1, -9-3, -34b/c, -129-2) was investigated with the use of representative set of CCRCC samples (46 cases). Methylation of three genes miR-124a-2, -124a-3, and -129-2 was studied in kidney tumors for the first time. Methylation analysis was performed using methyl specific PCR. It is shown that the frequency of methylation of six genes (miR-124a-2, -124a-3, -9-1, -9-3, -34b/c and -129-2) was significantly higher in tumor samples than in samples of histologically normal tissue (P3 x 10(-5) by Fisher's exact test). These results suggest the properties of tumor suppressors for the six miRNA genes indicated in CCRCC. We also found correlations between the methylation frequency of some miRNA genes and signs of the progression of CCRCC (tumor size, clinical stage, loss of differentiation, and metastasis).

Somatic mutations in the KRAS gene are important markers of some types of tumors, for example, pancreatic cancer, and may be useful in early diagnostics. A biochip has been developed which allows determining most frequent mutations in 12, 13 and 61 codons of the KRAS gene. To increase the sensitivity of the method and to make possible the analysis of minor fractions of tumor cells in clinical samples the method of blocking a wild type sequence PCR amplification by LNA-oligonucleotides has been used. The product of LNA-clamp PCR was further hybridized with oligonucleotide probes, immobilized on biochip. Biochip was tested with 42 clinical DNA samples from patients with pancreatic cancer, mostly ductal adenocarcinomas. As reference methods, the RFLP analysis and sequencing were used. The developed approach allows detecting somatic mutations in the KRAS gene if the portion of tumor cells with mutation is at least 1% of whole cell population.

The purpose of this study was to investigate informativety and clinical significance of most frequent somatic alterations in K-ras, TP53, CDKN2A, MADH4 and more uncommon mutations in BRCA1, BRCA2, CHEK2 genes, which arise on preinvasive stage in sporadic pancreatic adenocarcinomas (PA), in Russian patients. We examined surgically resected and manually microdissected primary PA tissue samples and samples of normal pancreatic tissue for 37 individuals. K-ras mutations in codon 12 were found in 24 tumors (0.65) and none of normal tissue samples. No mutations were detected in BRCA1(185delAG, 300TG, 4153delA, 4158AG,5382insC), BRCA2 (695insT, 6174delT) and CHEK2 (1100delC) genes. Informativety for allelic loss of three tumor suppressor genes studied had not statistically significant differences: 60% - for TP53 (GDB186817) and CDKN2A (D9S974 + D9S162); and 65.7% - for MADH4 (D18S363 + D18S474) (t = 0.48). Maximal frequency of loss of heterozygosity (LOH) was observed for CDKN2A - 0.95. For TP53 and MADH4 it was 0.62 and 0.70 respectively. The tumors included 80% cases showing LOH on different chromosomal loci. The combination of K-ras mutations (c.12) and LOH at 9p, 17p and 18q resulted in a high informativety of selected molecular markers: 85.7%. Instability of microsatellites was found only in 9% of PA.

Ovarian cancer (OC) is one of the leading cause of cancer death in women. Inherited BRCA1 and BRCA2 mutations strikingly increase OC risk (with lifetime risk estimates ranging at 10-60%). Mutation 1100delC in CHEK2 gene was shown to be associated with breast cancer in women carrying this mutation. Knowledge of the nature and frequency of population-specific mutations in these genes is a critical step in the development of simple and inexpensive diagnostic approaches to DNA analysis. The frequencies of 185delAG, 300TG, 4153delA, 4158AG, 5382insC mutations in BRCA1 gene, 695insT and 6174delT mutations in BRCA2 gene and 1100delC mutation in CHEK2 gene were analyzed using biochips in Russian OC patients. We studied 68 women who received a diagnosis of epithelial OC and 19 women with primary multiple tumors involving the ovaries. The 185delAG, 300TG, 4153delA and 5382insC in BRCA1 gene were identified. The most prevailing mutation was 5382insC in BRCA1 gene (87.5% of all BRCA1 mutations OC patients, 50.0% in patients with primary multiple tumors involving the ovaries). No mutations in BRCA2 and CHEK2 genes were detected.

The identification of hereditary variants of cutaneous melanoma and analysis of the role of hereditary factors and syndromes predisposing to cutaneous melanoma were carried out. The involvement of individual nevus phenotypes in the development of this disease was determined. Based on a survey of recent molecular biological data and our studies, the etiological and genetic heterogeneity of cutaneous melanoma is reported. In relatives of patients with cutaneous melanoma and persons with multiple pigmented nevi, the malignant tumors proved to be differentiated in the direction of the neural crist tissues and/or derivatives of cutaneous mesenchyma. Based on the evidence obtained, the approaches have been developed to formation of risk groups for the purpose of early diagnostics of cutaneous melanoma.

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.

The paper reviews the data on the molecular structure of the protooncogene RET encoding for receptor-type protein kinase, on the mechanism of transformation of the normal protooncogene RET to a dominant transforming oncogene, and on RET mutations detected in patients with the MEN-2 syndrome. Moreover, it presents the authors' own findings. The familial medullary thyroid carcinoma burdened genealogy shows a new point mutation TCG(Ser)--GCG(Ala) in codon 891, in the exon 15 of the protooncogene RET. This mutation was not detected in the chromosomes of healthy individuals. Analyzing the linkage with two known and two new polymorphic markers showed that there was a cisaggregation of informative polymorphic markers, phenotypic manifestation of the disease, and mutations in the genealogy in question. In the protooncogene RET, there were two new polymorphisms: G/A at position 24 in intron 14 and C/T in codon 836 (exon 14). The rate of the polymorphism encountered in codon 836 proved to be similar for the Russians and the Germans (0.96%), which was also seen for two earlier described polymorphisms in codon 691 (0.80 and 0.81, respectively) and in codon 904 (0.21 and 0.22). At the same time, there were statistically significant differences in the rates of intron 14 polymorphism (0.87 and 0.77, respectively). In a family having MEN 2, a proband displayed TGC--CGC mutation in codon 634 of the gene RET in the heterozygous state. The mutation results in substitution of cysteine amino acid residue in the cysteine-rich extracellular domain of protein kinase encoded by the gene RET for arginine. The results of molecular analysis were used to confirm its clinical diagnosis and to indicate that effective care should be delivered in MEN 2a.

Segregation analysis of inheritance of adenomas, colorectal cancer (CRC), and multiple primary malignant tumors (MPMT) revealed their low penetrance: from 3.2 to 29% for homozygotes and from 2.0 to 14.4% for heterozygotes. This cast a doubt on the monogenic type of their inheritance, although it formally corresponded to the quasidominant type, i.e., only a fraction of heterozygotes was expressed. Therefore, the multifactorial model of inheritance was tested, which seemed more adequate because genetic heterogeneity of adenomas, CRC, and MPMT was suggested from the data on genetic correlations between various clinical forms. Predisposition to various clinical forms of adenomas, CRC, and MPMT was shown to be specific, i.e., the ratio between genetic and environmental predisposition-determining factors reflected pathogenetic differences between these diseases. However, analysis of variance which revealed genetic (pathogenetic) distinctions between adenomas, CRC, and MPMT is insufficient to confirm complete nosologic identity of each of these clinical forms.

A clinical/genealogical study of colorectal adenomas (CRA) and cancer (CRC), and multiple primary malignant tumors (MPMT) was performed. The CRA prevalence in the population was 4.7 +/- 1.4% (single CRA--6.3% and multiple CRA--3.0%). The frequencies of malignant adenomas, 0.7% CRC, and MPMT were 0.7, 0.17 +/- 0.07%, and 0.004 +/- 0.003%, respectively. The prevalence of cancer of the female reproductive organs was also estimated (cancer of uterine body, 0.2 +/- 0.1%; cancer of ovaries, 0.08 +/- 0.1%; cancer of uterine cervix, 0.55 +/- 0.1%; cancer of mammary gland 0.57 +/- 0.1%). The main parameters of the familial inheritance of adenomas, CRC, and MPMT were also studied in general and at various clinical variants of these pathologies. Among the first-degree relatives of patients with solitary and multiple adenomas, the adenoma frequencies were 5.9 +/- 0.6 and 3.7 +/- 0.5%, respectively. The CRC frequency among the first-degree relatives of patients with adenoma was 3.0 +/- 0.6% and the frequency of MPMT was 5.8 +/- 0.6%. On the basis of the data obtained on frequencies of malignant tumors in various groups of relatives, the following conclusions were made: (1) in families of each proband group, specific pathology was accumulated; (2) the familial frequency of malignant tumors increased with an increase in proliferative processes and the severity of a pathology in probands.

Epidemiologic and clinical genetic data on cutaneous malignant melanoma (CMM) are presented. The incidence of CMM in Moscow from 1983 to 1987 was analyzed. Cumulative incidence (cumulative risk) was calculated for various life periods on the basis of estimates for various age groups, which were used as population frequencies. By the age of 85, these frequencies were 0.35% for males and 0.38% for females. Among relatives of patients, the incidence of CMM was 1.420 +/- 0.498% for males and 1.110 +/- 0.348% for females; i.e., the incidence exceeded the population frequency by a factor of 3 or 4. As a whole, the familial frequency of cancer was equal to 13.3% for male probands and 14.2% for female probands, i.e., more than three times higher than the population frequency. The data obtained formed the basis for the development of CMM classification. hereditary and nonhereditary variants of cutaneous melanoma were identified. Familial cases and CMM that occurred against the background of inherited disease or syndromes were classified as hereditary variants of CMM; taken together, they accounted for 38.8%. The data provided grounds for identification of families at increased risk for the development of CMM.

Evidence for the role of dysplastic nevi (DN) in the development of cutaneous malignant melanoma (CMM) is presented. Primary multiple foci of CMM were found considerably more frequently in individuals with DN. The frequency of primary multiple CMM was found to be 3.1% in males with DN and 0.9% in males without DN; in females, 6.8 and 0.6%, respectively. Genetic correlation analysis was performed to determine the genetic interrelation between DN and CMM. In general, the genetic correlation coefficient was 0.9; i.e., predisposition to DN and CMM is determined by common genes for 90%. The frequency and distribution of constitutive fragile sites in chromosomes of peripheral lymphocytes was studied by the method of principal components for discrete variables. The site 1p22 is responsible for variability of the traits CMM and DN for 98.5%. On the one hand, this suggests that one of the supposed genes for CMM can be located at 1p22; on the other hand, CMM and DN are likely to have a common genetic determination or to be very tightly linked. Estimates of risk for the development of CMM in patients' relatives are given with reference to the variants of CMM manifestation and presence of DN.

The results of familial population analysis of stomach cancer and multiple primary malignant tumors (MPMTs) are presented. The data obtained provide evidence for the multifactorial nature of stomach cancer. Hereditary factors accounted for 32% of the general predisposition of individuals to stomach cancer. The age-related character of stomach cancer was established. Genetic heterogeneity of this tumor is suggested by the data obtained. Significant genetic commonness in the inheritance of stomach, colon, Genetic Analysis and Prognosis for Malignant Tumors in breast, endometrial, and ovarian cancer in families of MPMT patients was demonstrated on the basis of the obtained genetic correlations between tumor types in MPMT patients and solitary tumors in members of their families. The greatest genetic load was shown for families of MPMT patients, as compared with families of patients with solitary tumors, the coefficient of MPMT inheritance being equal to 77.4%. The data on the genetic character of stomach cancer and MPMT formed the basis for the identification of criteria for developing methodological approaches to the screening of individuals from risk groups to facilitate early diagnosis and prevention of cancer.

Clinical-genetic examination of 305 patients with multiple primary tumors aimed at determining the rate of genetic burden to their development and community of joint accumulation of tumors in families of these patients has revealed a significant genetic community of inheritance of breast cancer, carcinomas of colon, endometrium, ovaries and stomach in the families of patients with multiple primary tumors. Comparative analysis of genetic correlations has shown the greatest genetic burden in families of patients with multiple primary tumours as against the families of patients with solitary cancer.

The results of a complex family and population epidemiologic study of gastric cancer pointed to inheritance as an important factor of the incidence of this disease. However, there may be different combinations of genetic factors, on the one hand, and genetic and environmental ones, on the other, versus age and sex. This should be considered in conducting screening for families at genetic risk for stomach cancer and taking measures aimed at eliminating carcinogenic factors which increase the likelihood of familial cancer incidence. Such considerations should contribute to a certain degree to early diagnosis and prevention of the disease.

The authors sum up the results of clinical and genealogic examinations of 2460 patients with most prevalent tumors, i.e. gastric and mammary carcinomas, melanomas. The obtained values of segregation frequencies for these tumors have proved to be lower than the theoretically expected values for monogenic types of inheritance. A genetic and epidemiologic approach, employed in the tumors analysis, has demonstrated the multifactorial nature of these tumors: the contribution of the genetic factors in mammary carcinoma has made up 52%, in gastric carcinoma 22% for male and 41.1% for female subjects, with the X-chromosome-linked genetic components making up 19%. The studies have shown the possibility of genetic heterogeneity of the tumor forms, identically localized. Basing on these data, the authors have plotted 'repeated risk tables' to assess the potentiality of new cases of the disease in the patients' families; such tables may be useful for practical medicogenetic counselling.