Epstein–Barr virus LMP1 oncogene polymorphism in tatar and slavic populations in Russian Federation impacting on some malignant tumours

Objective: To compare genetic structure of the main Epstein–Barr virus (EBV) oncogene, latent membrane protein 1 (LMP1), in EBV strains circulating in two genetically distinct ethnic populations in Russian Federation, Tatars and Slavs, as well as assess an impact of diverse LMP1 variants on incidence and mortality rate for some malignant tumors partially associated with EBV infection. Materials and methods. Oral washing samples were collected from 60 ethnic Kazan Tatars and 65 ethnic Moscow Slavics. Carboxy-terminal nucleotide sequences (41 and 40 sequences, respectively) derived from hypervariable LMP1 gene region were amplified from EBV DNA samples. Next, final nucleotide sequences were translated into amino acid sequences and analyzed according to classification by Edwards et al. Results. Analysis of 41 and 40 LMP1 samples obtained from ethnic Kasan Tatars and ethnic Moscow Slavics, respectively, revealed significant difference in relevant amino acid structures. In particular, all LMP1 samples derived from Moscow Slavics were found to belong to the four protein variants: B95.8/A, Med–, China1 and NC. Among them, low-transforming variant B95.8/A was dominant (82.5%). In contrast, solely 21 out of 41 LMP1 samples derived from ethnic Tatars were classified as B95.8/A, Med– and China1 variants. Importantly, the percentage of low-transforming B95.8/A variant among ethnic Tatar samples was significantly lower compared to that one found in Moscow Slavics (29.3% vs. 82.5%). On the other hand, seven (17.1%) out of 20 other samples formed a unique protein mono group characterized by LMP1 amino acid sequence differed from that one available in the GenBank database. Such group of variants was designated as LMP1-TatK. The remaining 13 samples (31.7%) did not match either protein variants, thereby forming the “beyond classification” (LMP1-TatBC) group. Conclusion. The data obtained suggest that various LMP1 variants exist in EBV strains persisting in ethnic Tatrs and ethnic Slavics examined in Russian Federation. It was also found that EBV strains isolated from ethnic Tatars contained a unique LMP1 gene variant encoding protein LMP1-TatK lacked in EBV strains derived from ethnic Moscow Slavics. Taking into account the genealogy of Tatars, it cannot be ruled out that EBV strain bearing LMP1-TatK variant represented ethnically specific EBV strain that might circulate many centuries ago among their historical human predecessors called Mongol-Tatar tribes. In addition, it was shown that the LMP1 variants in EBV strains isolated from ethnic Kazan Tatars and ethnic Moscow Slavics did not affect the incidence and mortality of different forms of cancer consisting of EBV-associated cases

Вирус Эпштейна-Барр у адыгейцев и славян в России: типы вируса, варианты LMP1 и злокачественные новообразования

Introduction. It is known that the structural features of the Epstein-Barr virus (EBV) affect the manifestation of its biological properties. Based on differences in the sequences of the EBNA2, EBNA3A, -B, and -C genes, two types of the virus, EBV-1 and EBV-2, have been identified that have different ability to transform B cells in vitro and possibly playing certain role in the development of EBV-associated neoplasms.Aim. To study the prevalence of EBV-1 and EBV-2 in two ethnic groups, Аdygeans and Slavs, as well as the contribution of EBV-associated tumors to the overall incidence of malignant neoplasms certain organs and tissues.Materials and methods. DNA samples were extracted from 59 oral lavages of ethnic Аdygeans from Republic of Adygea and 40 such from oral cavity of ethnic Slavs of Moscow city. These samples were used for amplification of EBV DNA, determination of the concentration of viral DNA copies per 1 cell washout, as well as for amplification of EBV LMP1 followed by sequencing of the resulting gene samples and determination of their protein variant (LMP1).Results. Studies have shown that among the representatives of the Аdygeans the 2nd EBV type prevails, and among the Slavs, the 1st one. Epstein-Barr virus isolates in representatives of the two ethnic groups also differed in the structure of LMP1. Among the Slavs, a set of its LMP1 variants (B95.8/A, China, Med- and NC) was identified. However, among the Adygeans, the only variant - B95.8 and its subtype - B95.8/A was identified. EBV-1, which prevails among the representatives of the Slavs and has the ability to transform B-cells, was projected onto a higher incidence of tumors of the pharynx, stomach, Hodgkin's and non-Hodgkin's lymphomas (where EBV-associated cases cam occur) in the population of Moscow than in the population of the Republic of Adygea. However, the differences between incidence rates for these neoplasms (with the exception for the stomach tumors) were not statistically significant (p >0.5). A higher and statistically significantly different incidence rate of stomach cancer in residents of Moscow city, compared with that in residents of the Republic of Adygea, in our opinion, is not due to EBV-1 type and/or LMP1 variants, but rather is associated with a genetic predisposition the population of Moscow city to this tumor.Conclusion. The fact that two ethnic groups of Russia were found to be prevails by different types of EBV raises the question of their ethno-geographical association and their role in the induction of EBV-associated tumors. To resolve this issue additional studies in other geographical regions of Russia among representatives of different ethnic groups are required.Введение. Известно, что структурные особенности вируса Эпштейна-Барр (ВЭБ) влияют на проявление его биологических свойств. На основе различий в последовательностях генов EBNA2, EBNA3A, -B и -C идентифицированы 2 типа вируса, 1-й (ВЭБ-1) и 2-й (ВЭБ-2), обладающие разной способностью трансформировать В-клетки in vitro и, возможно, играющие определенную роль в возникновении ВЭБ-ассоциированных новообразований.Цель исследования - изучение распространенности ВЭБ-1 и вЭБ-2 у 2 этносов, адыгейцев и славян, а также вклада ассоциированных с ВЭБ случаев в общую заболеваемость злокачественными новообразованиями определенных органов и тканей.Материалы и методы. Из 59 смывов полости рта этнических адыгейцев Республики Адыгея и 40 таковых этнических славян Москвы экстрагировали образцы ДНК. Эти образцы использовали для амплификации ДНК ВЭБ, определения концентрации копий вирусной ДНК на 1 клетку смыва, а также для амплификации LMP1 ВЭБ с последующим секвенированием полученных образцов гена и выявления их белкового варианта (LMP1).Результаты. Исследования показали, что у представителей адыгейцев преобладает ВЭБ-2, а у славян - ВЭБ-1. изоляты ВЭБ у представителей 2 этносов также различались по структуре его LMP1: у славян выявлен целый набор его белковых вариантов ( В95.8/А, China, Med- и NC), а у адыгейцев - единственный вариант - B95.8 и его подтип -B95.8/A. доминирующий у представителей славян ВЭБ-1, обладающий способностью трансформировать в-клетки, проецировался на более высокую у населения Москвы, чем у населения Республики Адыгея, заболеваемость опухолями глотки, желудка, лимфомой Ходжкина и неходжкинскими лимфомами, в которых встречаются ВЭБ-ассоциированные случаи. Однако различия между показателями заболеваемости для указанных патологий (за исключением данных для желудка) были статистически недостоверными (p >0,5). Более высокий и статистически достоверно отличающийся показатель заболеваемости раком желудка у жителей Москвы по сравнению с таковым у жителей Республики Адыгея, по нашему мнению, не обусловлен ВЭБ-1 и/или вариантами LMP1, а скорее связан с генетической предрасположенностью к этой опухоли населения Москвы.Заключение. Факт обнаружения у 2 этносов России превалирования различных типов ВЭБ поднимает вопрос об их этногеографической ассоциации и роли в индукции ВЭБ-ассоциированных новообразований. для решения этого вопроса необходимо проведение дополнительных исследований в других географических регионах России у представителей разных этносов

Вирус Эпштейна–Барр у этнических татар: инфицированность и сиквенсные варианты онкогена LMP1

Objective of the investigation was to study the infection of ethnic Tatars with the Epstein–Barr virus (EBV) and to analyze the genetic structure of the oncogene of the virus, the latent membrane protein 1 (LMP1), in the virus strains of Tatar origin. Materials and methods. The materials for the study were samples of boucle flushes of 60 students from the Kazan State Medical University who are ethnic Tatars (Tatars no less than in the 3rd generation). Amplified from DNA of boucle flushes the nucleotide sequences of the LMP1 samples translated into DNA amino acid sequences, have undergone classification based on the well-known and widely used in literature the R.H. Edwards et al. classification. Results. The analysis of nucleotide and deductive amino acid sequences of the 41 LMP1 amplicons revealed their homology with only three gene variants from the R.H. Edwards et al. classification (1999): 95.8/A (29.3 %; 12/41), Med– (14.6 %; 6/41) and China1 (7.3 %, 3/41). Such variants of LMP1 as Alaskan, Med+, Chinа2, China3 and NC, were not found. Among the LMP1 samples of Tatar origin in 20 cases (48.8 %), the composition of the mutations found did not allow them to be assigned to any of the oncogene variants listed above. Out of this number, in 7 (17.1 %) cases a mono group of LMP1 samples was found, differing not only from representatives of the Slavs, inhabitants of the European part of Russia, but also from other Kazan samples, and was designated as LMP1-TatK. The remaining 13 samples of LMP1 (31.7 %), not belonging to any of the known classifications, formed the group designated by us as an LMP1 group beside the classification (LMP1BC). Conclusion. Continuation of the study of the molecular-biological and functional properties of LMP1 in TatK and BC groups, which constitute 48.8 % of the number of gene samples studied, and an analysis of the peculiarities of the ethnic Tatar genotype, will probably help to clarify whether certain EBV strains influence morbidity and mortality in Tatar population with malignant neoplasms, which include EBVassociated cases.Цель исследования – изучение инфицированности вирусом Эпштейна–Барр (ВЭБ) этнических татар и анализ генетической структуры онкогена вируса, латентного мембранного белка 1 (LMP1), в штаммах вируса татарского происхождения. Материалы и методы. Материалом для исследования служили буккальные смывы 60 студентов Казанского государственного медицинского университета, являющихся этническими татарами (не менее чем в III поколении). Выделенную из смывов ДНК использовали для амплификаци LMP1. Амплифицированные из ДНК буккальных смывов нуклеотидные последовательности образцов LMP1, транслированные в аминокислотные последовательности, подверглись классификации на основании известной и широко используемой в литературе классификации R.H. Edwards и соавт. Результаты. Анализ нуклеотидных и транслированных аминокислотных последовательностей 41-го ампликона LMP1 выявил их гомологию только с 3 вариантами гена из классификации R.H. Edwards и соавт.: 95.8/А (29,3 %; 12/41), Med– (14,6 %; 6/41) и China1 (7,3 %; 3/41). Такие варианты LMP1, как Alaskan, Med+, Chinа2, China3 и NC, не обнаружены. В остальных 20 случаях (48,8 %) спектр обнаруженных мутаций в образцах LMP1 татарского происхождения не позволил их отнести ни к одному из перечисленных выше вариантов онкогена. Из них в 7 случаях (17,1 % всех исследованных образцов) обнаружена моногруппа вариантов LMP1, отличающаяся не только от представителей славян, жителей европейской части России, но и от других казанских образцов, и обозначенная нами, как LMP1-TatK. Остальные 13 образцов LMP1 (31,7 %), не относящихся ни к одной из известных классификаций, сформировали группу, обозначенную нами, как группа LMP1 вне классификации (LMP1ВК). Заключение. Дальнейшее изучение молекулярно-биологических и функциональных свойств LMP1 в группах ВК и TatK, составляющих 48,8 % от числа изученных образцов онкобелка, и анализ особенностей генотипа этнических татар, вероятно, позволят выяснить, оказывают ли определенные штаммы ВЭБ влияние на показатели заболеваемости и смертности злокачественными новообразованиями, в состав которых входят ВЭБ-ассоциированные случаи, у татарского населения

Epstein–Barr virus in the ethnic Tatars population: the infection and sequence variants of LMP1 oncogene

Objective of the investigation was to study the infection of ethnic Tatars with the Epstein–Barr virus (EBV) and to analyze the genetic structure of the oncogene of the virus, the latent membrane protein 1 (LMP1), in the virus strains of Tatar origin. Materials and methods. The materials for the study were samples of boucle flushes of 60 students from the Kazan State Medical University who are ethnic Tatars (Tatars no less than in the 3rd generation). Amplified from DNA of boucle flushes the nucleotide sequences of the LMP1 samples translated into DNA amino acid sequences, have undergone classification based on the well-known and widely used in literature the R.H. Edwards et al. classification. Results. The analysis of nucleotide and deductive amino acid sequences of the 41 LMP1 amplicons revealed their homology with only three gene variants from the R.H. Edwards et al. classification (1999): 95.8/A (29.3 %; 12/41), Med– (14.6 %; 6/41) and China1 (7.3 %, 3/41). Such variants of LMP1 as Alaskan, Med+, Chinа2, China3 and NC, were not found. Among the LMP1 samples of Tatar origin in 20 cases (48.8 %), the composition of the mutations found did not allow them to be assigned to any of the oncogene variants listed above. Out of this number, in 7 (17.1 %) cases a mono group of LMP1 samples was found, differing not only from representatives of the Slavs, inhabitants of the European part of Russia, but also from other Kazan samples, and was designated as LMP1-TatK. The remaining 13 samples of LMP1 (31.7 %), not belonging to any of the known classifications, formed the group designated by us as an LMP1 group beside the classification (LMP1BC). Conclusion. Continuation of the study of the molecular-biological and functional properties of LMP1 in TatK and BC groups, which constitute 48.8 % of the number of gene samples studied, and an analysis of the peculiarities of the ethnic Tatar genotype, will probably help to clarify whether certain EBV strains influence morbidity and mortality in Tatar population with malignant neoplasms, which include EBVassociated cases