REVIEWS Hereditary Breast-Ovarian Cancer Syndrome in Russia A. P. Sokolenko1,2, A. G. Iyevleva1,2, N. V. Mitiushkina1, E. N. Suspitsin1,2, E.`V. Preobrazhenskaya1, E. Sh. Kuligina1, D. A. Voskresenskiy2, O. S. Lobeiko1, N. Yu. Krylova1, T. V. Gorodnova1, K. G. Buslov2, E. M. Bit-Sava1, G. D. Dolmatov4, N. V. Porhanova5, I. S. Polyakov5, S. N. Abysheva1, A. S. Katanugina1, D. V. Baholdin1, G. A. Yanus1,2, A. V. Togo1, V. M. Moiseyenko1,3, S. Ya. Maximov1, V. F. Semiglazov1, E. N. Imyanitov1,2,3* 1Petrov Institute of Oncology, St. Petersburg 2State Pediatric Medical Academy, St. Petersburg 3Medical Academy for Postgraduate Studies, St. Petersburg 4City Oncological Hospital, St. Petersburg 5Kuban State Medical University, Krasnodar *E-mail: [email protected] Received 20.09.2010 Copyright © 2010 Park-media, Ltd. This is an open access article distributed under the Creative Commons Attribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Hereditary breast-ovarian cancer syndrome contributes to as much as 5–7% of breast cancer (BC) and 10–15% of ovarian cancer (OC) incidence. Mutations in the “canonical” genes BRCA1 and BRCA2 occur in 20–30% of affected pedigrees. In addition to BRCA1 and BRCA2 mutations, germ-line lesions in the CHEK2, NBS1, and PALB2 genes also contribute to familial BC clustering. The epidemiology of hereditary breast-ovarian cancer in Russia has some specific features. The impact of the “founder” effect is surprisingly remarkable: a sin- gle mutation, BRCA1 5382insC, accounts for the vast majority of BRCA1 defects across the country. In addition, there are two other recurrent BRCA1 alleles: BRCA1 4153delA and BRCA1 185delAG. Besides BRCA1, in Russia breast cancer is often caused by germ-line alterations in the CHEK2 and NBS1 genes. In contrast to BRCA1 and BRCA2, the CHEK2 and NBS1 heterozygosity does not significantly increase the OC risk. Several Russian breast cancer clinics recently started to investigate the efficacy of cisplatin in the therapy of BRCA1-related cancers; initial results show a unique sensitivity of BRCA1-associated tumours to this compound. KEYWORDS breast cancer, ovarian cancer, hereditary cancer syndromes, BRCA1, CHEK2, NBS. INTRODUCTION diseases are the main components of the most frequent Breast cancer (BC) and ovarian cancer (OC) contrib- genetic disease – hereditary breast-ovarian cancer ute significantly to cancer incidence and mortality. BC (HBOC) syndrome [3]. is the most frequent malignant pathology in women, HBOC has been intensively studied since the early with the lifetime risk reaching approximately 10%. In 1990s. In 1994, the first gene associated with this syn- some cases, BC can be easily diagnosed at early stages drome was discovered and named BRCA1 (BReast and ultimately cured. Unfortunately, even with the CAncer 1) [4], and the second gene, BRCA2, was dis- implementation of total population screening, the BC covered a year later [5]. Although BRCA1 and BRCA2 related mortality rate has not decreased significantly, code for different proteins, their products play a key due to insufficient sensitivity of available diagnostic role in preserving genome integrity by participating in methods, as well as the high metastatic potential of DNA repair [6]. Notably, BRCA1 or BRCA2 mutations some BC forms [1]. OC is a much rarer disease than BC, occur only in 20–30% of familial BC/OC cases. There being found only in 1.5% of women around the world; has been an active search for other hereditary BC/OC however, it is almost always diagnosed at late (incur- genes. The effort has already helped to identify several able) stages. Early ovarian tumours do not cause symp- new relevant genes, e.g. CHEK2, NBS1, PALB2 etc. [7]. toms and are often missed by ultrasound examination The first studies on the contribution of the BRCA1 and СА-125 biomarker assay [2]. Both BC and OC are and BRCA2 genes in BC and OC incidence were per- diseases of the reproductive system; therefore, their formed on European and North American women. The hormonal, metabolic, and behavioural risk factors are mutations in these genes are very diverse [8], which common to a certain extent. Interestingly, these two complicates BRCA diagnostics. Indeed, to perform the VOL. 2 № 4 (7) 2010 | ACTA NATURAE | 31 REVIEWS complete analysis of BRCA1 and BRCA2, one needs not counts for up to 90% of all BRCA1 mutations in women only to perform full sequencing of these long genes, but living in distant regions of Russia, ranging from Mos- also to find rearrangements using the MPLA method cow to St. Petersburg, Krasnodar, Tomsk, etc. [12, 18– (multiplex ligation-dependent probe amplification). 20, 22–24, 26]. Moreover, this mutation is dominant in In the mid-1990s, it was established that the so-called neighboring countries with a mostly Slavic population “founder effect” was present in some small isolated such as Poland, Belarus, Latvia, and Lithuania [14–17]. ethnic groups. For example, in females Ashkenazi Jew Notably, the relative genetic homogeneity of the Slavs nearly all BRCA1 and BRCA2 mutations are represent- is in accordance with the results of general popula- ed by only 3 recurrent alleles, i.e. BRCA1 185delAG, tion studies on the genetic diversity of people living in BRCA1 5382insC, BRCA2 6174delT; BRCA2 999del5 is Russia [31]. The BRCA1 5382insC allele frequency in a prevailing mutation in Icelandic females [9, 10]. Pop- healthy women is approximately 0.1%. This variant ac- ulation-specific distribution of hereditary cancer mu- counts for approximately 2–5% of total BC cancer inci- tations may significantly affect the design of genetic dence. Among the high-risk patients (familial cancers, studies. In countries without a strong founder effect, bilateral breast tumours, or early onset cancers), this only cancer cases with a high probability of detecting mutation is observed in 10% of patients. The BRCA1 the mutation are usually taken into the analysis; they 5382insC contribution to the OC rate is even bigger: include oncological patients with a proven cancer his- this mutation is found in 10–15% of patients (Table). tory in their family and/or patients with multiple pri- It is important to note that in contrast to the BC, the mary tumours and/or young women with BC or OC. BRCA1 5382insC distribution in women with OC is in- The presence of the founder effect greatly simplifies dependent of age, family history, and the number of the DNA testing procedure, enabling comprehensive primary tumours [26]. Therefore, while DNA testing of studies, such as revealing the influence of hereditary BC patients can be restricted by high-risk cases, all OC cancer gene mutations on the overall BC/OC incidence patients have to undergo BRCA testing. rate, as well as analyzing the gene mutations in healthy In the pioneering report [12], the relatively frequent women [11]. BRCA1 4153delA (4154delA) mutation was described. The mutation was found not only in Russian patients, EPIDEMIOLOGY OF THE BRCA1, BRCA2, but also in those from other neighboring Slavic coun- CHEK2 AND NBS1 MUTATIONS IN RUSSIA tries [14–17]. The BRCA1 4153delA frequency in Rus- In Russia, the studies of the HBOC syndrome were sian patients, however, is an order of magnitude lower initiated later than in the U.S. and Europe but they than that of the BRCA1 5382insC mutation, which produced rather unexpected results. The first paper complicates the study of the BRCA1 4153delA epide- published in 1997 reported on the results obtained in miology. Polish scientists had reported on the prefer- patients with familial OC living in Moscow and sev- ential association of BRCA1 4153delA with OC [14, 32]; eral other regions of the former Soviet Union [12], the however, their observations could not be confirmed in main result being the extremely high frequency of the later studies [21]. BRCA1 5382insC mutation. As was mentioned above, A number of Russian studies indicate that there is this mutation had been first found in Jewish women; a relatively high frequency of the “Jewish” BRCA1 therefore, it had been for many years considered in the 185delAG allele in Russian patients [20, 23, 24, 26]. In context of that particular ethnic group [13]. However, contrast to the BRCA1 5382insC mutation, however, it appeared that the BRCA1 5382insC mutation was this mutation is not dominant and could be better ex- not of Jewish origin. This mutation is found not only plained by interethnic marriages. in females living in various regions of Russia, but also The BRCA1 gene mutations in familial BC/OC pa- in native populations of Poland, Lithuania, Latvia, and tients have been repeatedly analyzed by sequencing of Belarus [14–17]. It is perhaps more accurate to say that all coding sections, with similar results obtained in Mos- the BRCA1 5382insC mutation is of Slavic origin, and cow, St. Petersburg, and Tomsk. It has been shown that that the relatively high frequency of this mutation in non-founder mutations are much rarer in Russia than Ashkenazi Jews observed mostly in Eastern Europe in Europe and North America [12, 18–20, 23, 33]. Given is likely due to the long coexistence of the Slavic and the rapidly falling costs of DNA analysis, it is logical Jewish peoples in the Baltic region and adjacent ter- to expect an increase in the use of BRCA1 sequencing ritories. even for the patients with low probability of cancer The epidemiology of the BRCA1 5382insC mutation genetic predisposition. So far, there has been only one is surprising, to say the least, since it contradicts the study on gross rearrangements of the BRCA1 gene, and stereotype of the multinational culture in the Russian the data indicate a low frequency of such mutations in Empire and the Soviet Union. BRCA1 5382insC ac- Russian patients with hereditary BC/OC [33]. 32 | ACTA NATURAE | VOL. 2 № 4 (7) 2010 REVIEWS Table. Hereditary breast-ovarian cancer genes in Russia Frequency in “high-risk” Frequency in Frequency Frequency Major (familial and/or bilat- non-selected in ovar- Gene in healthy References mutations eral and/or young-onset) breast cancer ian cancer subjects breast cancer patients patients patients BRCA1 5382insC, 4153delA, 185delAG ~ 0.1% ~ 10% 2–4% > 10% [18–26] CHEK2 1100delC, IVS2+1G>A < 1% ~ 5% ~ 2% <1% [26–29] NBS1 657del5 0.5% ~ 1% 0.7% <1% [29, 30] While the BRCA1 gene has been systematically It is believed that timely detection of the genetic defect analyzed, data on the BRCA2 mutations in Russia are can help to avoid fatal cancer outcome. Women with het- scarce. In Siberia, there have been several reported erozygous BRCA1 and BRCA2 genes are under regular cases of BRCA2 being inactivated in hereditary BC/ observation for early BC/OC diagnostics. In addition, OC patients [18]; at the same time, studies performed preventive surgical removal of target tissues is recom- in Moscow revealed no connection between this gene mended [40] to women with a BRC A mutation [40]. and hereditary BC/OR in the European part of Russia Healthy carriers of hereditary cancer genes are usu- [23]. Polish scientists performed comprehensive studies ally found during the examination of relatives of BC showing that the BRCA2 mutations contributed very or OC patients with the genetic defect. According to little to BC and OC aetiology in Slavs [34]. current ethical standards, the patient herself should Another interesting feature of Russian patients is the encourage her relatives to undergo DNA analysis. Our frequent occurrence of CHEK2 mutations. This gene, experience shows that very few relatives of the BRCA as BRCA1 and BRCA2, participates in the maintain- mutation carriers undergo DNA testing. This could be ing of genomic integrity. Heterozygous CHEK2 muta- because either hereditary cancer patients conceal their tions are frequent in Finland, the Netherlands, Poland, condition to their relatives or the healthy women avoid and several other countries [14, 35]. In Russia, CHEK2 medical procedures aimed at determining cancer risk. mutations are found in fewer than 2% of “random” Even more surprising is the fact that the majority of BC patients, and in up to 5% of hereditary cancer pa- healthy women with BRCA1 mutations monitored by tients [27]. In contrast to the situation with BRCA1 and us are extremely careless when it comes to undergoing BRCA2, heterozygous inactivation of CHEK2 does not preventive screening. Preventive surgery presents the increase the risk of OC [21, 26]. biggest challenge. While it has become a routine clinical Another important gene for Russia is NBS1 (NBN). practice in the U.S., Canada, Western and Eastern Eu- Homozygous defects of this gene were found in pa- rope, Israel, Australia, South Africa, Japan, Korea and tients with serious immunodeficiency, the so-called Ni- other countries, yet in Russia the discussion of such an jmegen breakage syndrome [36]. Heterozygous NBS1 option is suppressed or distorted not only by ordinary mutations are observed mostly in Slavs, and they are people but even by the medical community. associated with an increased BC risk [30, 37, 38]. No in- While preventive measures for BRCA carriers are creased frequency of this gene defect is observed in OC frequently neglected, many doctors are enthusiastic to patients [26]. Nevertheless, in the only reported case try novel therapeutic schemes for HBOC patients. In of combined germ-line heterozygosity for BRCA1 and 2009, Polish scientists published the results of clinical NBS1 genes in ovarian tumor, there was somatic inac- studies showing the unique sensitivity of BRCA1-asso- tivation of the NBS1 gene, whereas the BRCA1 gene ciated tumors to cisplatin [41]. This is possible because remained intact [39]. This observation may be an argu- of unique therapeutic window. In tumors of the BRCA1 ment speaking in favor of the involvement of the NBS1 mutation carriers, complete inactivation of this gene gene in the degree of OC risk. is observed. It causes a homologous recombination de- fect. BRCA1-deficient cells are extremely vulnerable MEDICAL ASPECTS OF HEREDITARY to cisplatin, a well-known DNA crosslinking compound BC AND OC IN RUSSIA causing double-strand breaks. It is important that nor- The main goal of hereditary cancer syndrome diagnostics mal tissues, in contrast to neoplasms, retain hetero- is to find healthy women with corresponding mutations. zygous BRCA1 status, the presence of a single func- VOL. 2 № 4 (7) 2010 | ACTA NATURAE | 33 REVIEWS tional copy of the gene being sufficient for performing This work was supported by the Ministry of Education its functions. Russian scientists were the first to provide and Science (contract № 02.740.11.0780), the Russian independent confirmation of the results of Byrski et al. Foundation for Basic Research (grants № 08-04- [42]. Cisplatin is now commonly used for the therapy of 00369, 09-04-90402, 10-04-92110, 10-04-92601), and BRCA1-associated tumors in several Russian clinics. the Government of Moscow (project 15/10-Gene-M). REFERENCES Russ. J. Genet. 2005. V. 41. P. 318–322. 1. Benson J.R., Jatoi I., Keisch M., Esteva F.J., Makris A., 20. Loginova A.N., Pospekhova N.I., Lyubchenko L.N., Jordan V.C. // Lancet. 2009. V. 373. P. 1463–1479. Budilov A.V., Zakhar'ev V.M., Gar'kavtseva R.F., Ginter 2. Kristensen G.B., Tropé C. // Lancet. 1997. V. 349. P. 113–117. E.K., Karpukhin A.V. // Bull. Exp. Biol. Med. 2003. V. 136. 3. Narod S.A., Foulkes W.D. // Nat. Rev. Cancer. 2004. V. 4. P. 276–278. P. 665–676. 21. Krylova N.Y., Lobeiko O.S., Sokolenko A.P., Iyevleva A.G., 4. Miki Y., Swensen J., Shattuck-Eidens D., Futreal P.A., Rozanov M.E., Mitiushkina N.V., Gergova M.M., Porhanova Harshman K., Tavtigian S., Liu Q., Cochran C., Bennett L.M., T.V., Urmancheyeva A.F., Maximov S.Y., Togo A.V., Imyani- Ding W., Bell R., Rosenthal J., Hussey C., Tran T., McClure M., tov E.N. // Hered. Cancer. Clin. Pract. 2006. V. 4. P. 193–196. Frye C., Hattier T., Phelps R., Haugen-Strano A., Katcher H., 22. Sokolenko A.P., Mitiushkina N.V., Buslov K.G., Bit-Sava Yakumo K., Gholami Z., Shaffer D., Stone S., Bayer S., Wray E.M., Iyevleva A.G., Chekmariova E.V., Kuligina E.Sh., C., Bogden R., Dayananth P., Ward J., Tonin P., Narod S., Ulibina Y.M., Rozanov M.E., Suspitsin E.N., Matsko D.E., Bristow P.K., Norris F.H., Helvering L., Morrison P., Rosteck Chagunava O.L., Trofimov D.Y., Devilee P., Cornelisse C., P., Lai M., Barrett J.C., Lewis C., Neuhausen S., Cannon-Al- Togo A.V., Semiglazov V.F., Imyanitov E.N. // Eur. J. Cancer. bright L., Goldgar D., Wiseman R., Kamb A., Skolnick M.H. // 2006. V. 42. P. 1380–1384. Science. 1994. V. 266. P. 66–71. 23. SSmmiirrnnoovvaa TT..YY..,, PPoossppeekkhhoovvaa NN..II..,, LLyyuubbcchheennkkoo LL..NN..,, TTjjuu-- 5. Wooster R., Bignell G., Lancaster J., Swift S., Seal S., landin S.A., Gar’kavtseva R.F., Ginter E.K., Karpukhin A.V. Mangion J., Collins N., Gregory S., Gumbs C., Micklem G. // // Bull. Exp. Biol. Med. 2007. V. 144. P. 83–85. Nature. 1995. V. 378. P. 789–792. 24. SSookkoolleennkkoo AA..PP..,, RRoozzaannoovv MM..EE..,, MMiittiiuusshhkkiinnaa NN..VV..,, SShhee-- 6. Gudmundsdottir K., Ashworth A. // Oncogene. 2006. V. 25. rina N.Y., Iyevleva A.G., Chekmariova E.V., Buslov K.G., P. 5864–5874. Shilov E.S., Togo A.V., Bit-Sava E.M., Voskresenskiy D.A., 7. Oldenburg R.A., Meijers-Heijboer H., Cornelisse C.J., Devi- Chagunava O.L., Devilee P., Cornelisse C., Semiglazov V.F., lee P. // Crit. Rev. Oncol. Hematol. 2007. V. 63. P. 125–149. Imyanitov E.N. // Fam. Cancer. 2007. V. 6. P. 281–286. 8. Fackenthal J.D., Olopade O.I. // Nat. Rev. Cancer. 2007. V. 7. 25. Mitrofanov D.V., Chasovnikova O.B., Kovalenko S.P., P. 937–948. Liakhovich V.V. // Mol. Biol. (Mosk). 2009. V. 43. P. 930–936. 9. Neuhausen S.L. // Breast Cancer Res. 2000. V. 2. P. 77–81. 26. SSuussppiittssiinn EE..NN..,, SShheerriinnaa NN..YY..,, PPoonnoommaarriioovvaa DD..NN..,, SSookkoo-- 10. Ferla R., Calò V., Cascio S., Rinaldi G., Badalamenti G., lenko A.P., Iyevleva A.G., Gorodnova T.V., Zaitseva O.A., Carreca I., Surmacz E., Colucci G., Bazan V., Russo A. // Yatsuk O.S., Togo A.V., Tkachenko N.N., Shiyanov G.A., Ann. Oncol. 2007. V. 18. Suppl 6. P. vi93–vi98. Lobeiko O.S., Krylova N.Y., Matsko D.E., Maximov S.Y., Ur- 11. Abbott A. // Nature. 2000. V. 406. P. 340–342. mancheyeva A.F., Porhanova N.V., Imyanitov E.N. // Hered. 12. Gayther S.A., Harrington P., Russell P., Kharkevich G., Cancer Clin. Pract. 2009. V. 7. P. 5. Garkavtseva R.F., Ponder B.A. // Am. J. Hum. Genet. 1997. 27. Chekmariova E.V., Sokolenko A.P., Buslov K.G., Iyevleva V. 60. P. 1239–1242. A.G., Ulibina Y.M., Rozanov M.E., Mitiushkina N.V., Togo 13. Roa B.B., Boyd A.A., Volcik K., Richards C.S. // Nat. A.V., Matsko D.E., Voskresenskiy D.A., Chagunava O.L., Genet. 1996. V. 14. P. 185–187. Devilee P., Cornelisse C., Semiglazov V.F., Imyanitov E.N. // 14. Górski B., Cybulski C., Huzarski T., Byrski T., Gronwald Breast Cancer Res. Treat. 2006. V. 100. P. 99–102. J., Jakubowska A., Stawicka M., Gozdecka-Grodecka S., 28. FFeeddoorroovvaa OO..EE..,, LLiiuubbcchheennkkoo LL..NN..,, PPaaiiaaddiinnii IIuu..GG..,, KKaazzuubbss-- Szwiec M., Urbański K., Mituś J., Marczyk E., Dziuba J., kaia T.P., Amosenko F.A., Gar’kavtseva R.F., Zasedate- Wandzel P., Surdyka D., Haus O., Janiszewska H., Debniak lev A.S., Nasedkina T.V. // Mol. Biol. (Mosk). 2007. V. 41. T., Tołoczko-Grabarek A., Medrek K., Masojć B., Mierze- P. 32–36. jewski M., Kowalska E., Narod S.A., Lubiński J. // Breast 29. KKrryylloovvaa NN..YY..,, PPoonnoommaarriioovvaa DD..NN..,, SShheerriinnaa NN..YY..,, OOggoorroodd-- Cancer Res. Treat. 2005. V. 92. P. 19–24. nikova N.Y., Logvinov D.A., Porhanova N.V., Lobeiko O.S., 15. Tikhomirova L., Sinicka O., Smite D., Eglitis J., Hodgson Urmancheyeva A.F., Maximov S.Y., Togo A.V., Suspitsin S.V., Stengrevics A. // Fam. Cancer. 2005. V. 4. P. 77–84. E.N., Imyanitov E.N. // Hered. Cancer. Clin. Pract. 2007. V. 5. 16. EEllssaakkoovv PP..,, KKuurrttiinnaaiittiiss JJ..,, PPeettrraaiittiiss SS..,, OOssttaappeennkkoo VV..,, RRaa-- P. 153–156. zumas M., Razumas T., Meskauskas R., Petrulis K., Luksite 30. Buslov K.G., Iyevleva A.G., Chekmariova E.V., Suspitsin A., Lubiński J., Górski B., Narod S.A., Gronwald J. // Clin. E.N., Togo A.V., Kuligina E.Sh., Sokolenko A.P., Matsko Genet. 2010. V. 78. P. 373-376. D.E., Turkevich E.A., Lazareva Y.R., Chagunava O.L., 17. Uglanitsa N., Oszurek O., Uglanitsa K., Savonievich E., Bit-Sava E.M., Semiglazov V.F., Devilee P., Cornelisse C., Lubiński J., Cybulski C., Debniak T., Narod S.A., Gronwald Hanson K.P., Imyanitov E.N. // Int. J. Cancer. 2005. V. 114. J. // Clin. Genet. 2010 (in press). P. 585–589. 18. Tereschenko I.V., Basham V.M., Ponder B.A., Pharoah P.D. 31. Balanovsky O., Rootsi S., Pshenichnov A., Kivisild T., // Hum. Mutat. 2002. V. 19. P. 184. Churnosov M., Evseeva I., Pocheshkhova E., Boldyreva M., 19. GGrruuddiinniinnaa NN..AA..,, GGoolluubbkkoovv VV..II..,, TTiikkhhoommiirroovvaa OO..SS..,, BBrreezzhh-- Yankovsky N., Balanovska E., Villems R. // Am. J. Hum. neva T.V., Hanson K.P., Vasilyev V.B., Mandelshtam M.Y. // Genet. 2008. V. 82. P. 236–250. 34 | ACTA NATURAE | VOL. 2 № 4 (7) 2010 REVIEWS 32. Menkiszak J., Gronwald J., Górski B., Jakubowska A., 37. Steffen J., Nowakowska D., Niwińska A., Czapczak D., Huzarski T., Byrski T., Foszczyńska-Kłoda M., Haus O., Kluska A., Piatkowska M., Wiśniewska A., Paszko Z. // Int. Janiszewska H., Perkowska M., Brozek I., Grzybowska E., J. Cancer. 2006. V. 119. P. 472–475. Zientek H., Góźdź S., Kozak-Klonowska B., Urbański K., 38. Bogdanova N., Feshchenko S., Schürmann P., Waltes R., Miturski R., Kowalczyk J., Pluzańska A., Niepsuj S., Koc Wieland B., Hillemanns P., Rogov Y.I., Dammann O., Bre- J., Szwiec M., Drosik K., Mackiewicz A., Lamperska K., mer M., Karstens J.H., Sohn C., Varon R., Dörk T. // Int. J. Strózyk E., Godlewski D., Stawicka M., Waśko B., Bebenek Cancer. 2008. V. 122. P. 802–806. M., Rozmiarek A., Rzepka-Górska I., Narod S.A., Lubiński 39. PPoorrhhaannoovvaa NN..VV..,, SSookkoolleennkkoo AA..PP..,, SShheerriinnaa NN..YY..,, PPoonnoommaa-- J. // Int. J. Cancer. 2003. V. 106. P. 942–945. riova D.N., Tkachenko N.N., Matsko D.E., Imyanitov E.N. // 33. Iyevleva A.G., Suspitsin E.N., Kroeze K., Gorodnova T.V., Cancer Genet. Cytogenet. 2008. V. 186. P. 122–124. Sokolenko A.P., Buslov K.G., Voskresenskiy D.A., Togo A.V., 40. Dent R., Warner E. // Semin. Oncol. 2007. V. 34. P. 392– Kovalenko S.P., van der Stoep N., Devilee P., Imyanitov 400. E.N. // Cancer Lett. 2010. V. 298. Р. 258–263. 41. Byrski T., Huzarski T., Dent R., Gronwald J., Zuziak D., 34. Górski B., Byrski T., Huzarski T., Jakubowska A., Men- Cybulski C., Kladny J., Gorski B., Lubinski J., Narod S.A. // kiszak J., Gronwald J., Pluzańska A., Bebenek M., Fischer- Breast Cancer Res. Treat. 2009. V. 115. P. 359–363. Maliszewska L., Grzybowska E., Narod S.A., Lubiński J. // 42. Moiseyenko V.M., Protsenko S.A., Brezhnev N.V., Maxi- Am. J. Hum. Genet. 2000. V. 66. P. 1963–1968. mov S.Y., Gershveld E.D., Hudyakova M.A., Lobeiko O.S., 35. CHEK2 Breast Cancer Case-Control Consortium. // Am. Gergova M.M., Krzhivitskiy P.I., Semionov I.I., Matsko D.E., J. Hum. Genet. 2004. V. 74. 1175–1182. Iyevleva A.G., Sokolenko A.P., Sherina N.Y., Kuligina E.Sh., 36. Varon R., Seemanova E., Chrzanowska K., Hnateyko Suspitsin E.N., Togo A.V., Imyanitov E.N. // Cancer Genet. O., Piekutowska-Abramczuk D., Krajewska-Walasek M., Cytogenet. 2010. V. 197. P. 91–94. Sykut-Cegielska J., Sperling K., Reis A. // Eur. J. Hum. Genet. 2000. V. 8. P. 900–902. VOL. 2 № 4 (7) 2010 | ACTA NATURAE | 35