The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium

The hyperplastic processes of the endometrium can arise not only against the background of excessive influence of estrogen, but also against the background of epigenetic damages that affect apoptosis, cell proliferation, differentiation, and adhesion, and DNA reparation. The aim of our study was to...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Experimental Oncology
Datum:2018
Hauptverfasser: Marichereda, V.G., Bykovа, N.A., Bubnov, V.V., Manasova, G.S., Moskalenko, T.Y., Volyanska, A.G., Shevchenko, I.M., Adamovska, T.M.
Format: Artikel
Sprache:English
Veröffentlicht: Інститут експериментальної патології, онкології і радіобіології ім. Р.Є. Кавецького НАН України 2018
Schlagworte:
Online Zugang:https://nasplib.isofts.kiev.ua/handle/123456789/145574
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Назва журналу:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Zitieren:The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium / V.G. Marichereda, N.A. Bykovа, V.V. Bubnov, G.S. Manasova, T.Y. Moskalenko, A.G. Volyanska, I.M. Shevchenko, T.M. Adamovska // Experimental Oncology. — 2018 — Т. 40, № 2. — С. 109–113. — Бібліогр.: 21 назв. — англ.

Institution

Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-145574
record_format dspace
spelling Marichereda, V.G.
Bykovа, N.A.
Bubnov, V.V.
Manasova, G.S.
Moskalenko, T.Y.
Volyanska, A.G.
Shevchenko, I.M.
Adamovska, T.M.
2019-01-24T08:40:07Z
2019-01-24T08:40:07Z
2018
The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium / V.G. Marichereda, N.A. Bykovа, V.V. Bubnov, G.S. Manasova, T.Y. Moskalenko, A.G. Volyanska, I.M. Shevchenko, T.M. Adamovska // Experimental Oncology. — 2018 — Т. 40, № 2. — С. 109–113. — Бібліогр.: 21 назв. — англ.
1812-9269
https://nasplib.isofts.kiev.ua/handle/123456789/145574
The hyperplastic processes of the endometrium can arise not only against the background of excessive influence of estrogen, but also against the background of epigenetic damages that affect apoptosis, cell proliferation, differentiation, and adhesion, and DNA reparation. The aim of our study was to investigate and analyze the status of methylation of the promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium. Materials and Methods: The study groups were the following: I — patients with endometrial hyperplasia (EH, n = 9); II — patients with endometrial intraepithelial neoplasia (EIN, n = 10), III — control groups: 1) with endometrial cancer (EC, n = 4), and 2) healthy women (n = 4). Determination of promoter methylation of SFRP2 gene was carried out by the semiquantitative method of methylation-specific PCR assay. Results: The maximum level of methylation of SFRP2 gene promoter had been revealed in patients with EC — 42.80 ± 3.55% (р < 0.05). The patients of the I group had the lowest values of methylation of SFRP2 gene promoter — 10.66 ± 0.85%, while in patients of the II group this indicator was higher — 20.60 ± 0.95% (р < 0.05). In healthy women of the control group, methylation of SFRP2 gene promoter was detected in none of the samples. Conclusion: The content of the methylated SFRP2 gene in endometrial tissue of patients with hyperplastic processes higher than 20–25% allows relate these women to the risk group of EC development and dictates the need of intensive observation of such patients. Key Words: methylation, SFRP2 gene, hyperplastic processes of the endometrium.
en
Інститут експериментальної патології, онкології і радіобіології ім. Р.Є. Кавецького НАН України
Experimental Oncology
Original contributions
The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium
spellingShingle The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium
Marichereda, V.G.
Bykovа, N.A.
Bubnov, V.V.
Manasova, G.S.
Moskalenko, T.Y.
Volyanska, A.G.
Shevchenko, I.M.
Adamovska, T.M.
Original contributions
title_short The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium
title_full The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium
title_fullStr The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium
title_full_unstemmed The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium
title_sort analysis of methylation of dna promoter of sfrp2 gene in patients with hyperplastic processes of the endometrium
author Marichereda, V.G.
Bykovа, N.A.
Bubnov, V.V.
Manasova, G.S.
Moskalenko, T.Y.
Volyanska, A.G.
Shevchenko, I.M.
Adamovska, T.M.
author_facet Marichereda, V.G.
Bykovа, N.A.
Bubnov, V.V.
Manasova, G.S.
Moskalenko, T.Y.
Volyanska, A.G.
Shevchenko, I.M.
Adamovska, T.M.
topic Original contributions
topic_facet Original contributions
publishDate 2018
language English
container_title Experimental Oncology
publisher Інститут експериментальної патології, онкології і радіобіології ім. Р.Є. Кавецького НАН України
format Article
description The hyperplastic processes of the endometrium can arise not only against the background of excessive influence of estrogen, but also against the background of epigenetic damages that affect apoptosis, cell proliferation, differentiation, and adhesion, and DNA reparation. The aim of our study was to investigate and analyze the status of methylation of the promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium. Materials and Methods: The study groups were the following: I — patients with endometrial hyperplasia (EH, n = 9); II — patients with endometrial intraepithelial neoplasia (EIN, n = 10), III — control groups: 1) with endometrial cancer (EC, n = 4), and 2) healthy women (n = 4). Determination of promoter methylation of SFRP2 gene was carried out by the semiquantitative method of methylation-specific PCR assay. Results: The maximum level of methylation of SFRP2 gene promoter had been revealed in patients with EC — 42.80 ± 3.55% (р < 0.05). The patients of the I group had the lowest values of methylation of SFRP2 gene promoter — 10.66 ± 0.85%, while in patients of the II group this indicator was higher — 20.60 ± 0.95% (р < 0.05). In healthy women of the control group, methylation of SFRP2 gene promoter was detected in none of the samples. Conclusion: The content of the methylated SFRP2 gene in endometrial tissue of patients with hyperplastic processes higher than 20–25% allows relate these women to the risk group of EC development and dictates the need of intensive observation of such patients. Key Words: methylation, SFRP2 gene, hyperplastic processes of the endometrium.
issn 1812-9269
url https://nasplib.isofts.kiev.ua/handle/123456789/145574
citation_txt The analysis of methylation of DNA promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium / V.G. Marichereda, N.A. Bykovа, V.V. Bubnov, G.S. Manasova, T.Y. Moskalenko, A.G. Volyanska, I.M. Shevchenko, T.M. Adamovska // Experimental Oncology. — 2018 — Т. 40, № 2. — С. 109–113. — Бібліогр.: 21 назв. — англ.
work_keys_str_mv AT maricheredavg theanalysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT bykovana theanalysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT bubnovvv theanalysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT manasovags theanalysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT moskalenkoty theanalysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT volyanskaag theanalysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT shevchenkoim theanalysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT adamovskatm theanalysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT maricheredavg analysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT bykovana analysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT bubnovvv analysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT manasovags analysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT moskalenkoty analysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT volyanskaag analysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT shevchenkoim analysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
AT adamovskatm analysisofmethylationofdnapromoterofsfrp2geneinpatientswithhyperplasticprocessesoftheendometrium
first_indexed 2025-11-24T02:38:48Z
last_indexed 2025-11-24T02:38:48Z
_version_ 1850836961934180352
fulltext Experimental Oncology 40, 109–113, 2018 (June) 109 THE ANALYSIS OF METHYLATION OF DNA PROMOTER OF SFRP2 GENE IN PATIENTS WITH HYPERPLASTIC PROCESSES OF THE ENDOMETRIUM V.G. Marichereda1, N.A. Bykovа1, V.V. Bubnov1, G.S. Manasova1, T.Y. Moskalenko2, A.G. Volyanska1, I.M. Shevchenko1, T.M. Adamovska1 1Odesa National Medical University, Odesa 65082, Ukraine 2Maternity Hospital № 7, Odesa 65082, Ukraine The hyperplastic processes of the endometrium can arise not only against the background of excessive influence of estrogen, but also against the background of epigenetic damages that affect apoptosis, cell proliferation, differentiation, and adhesion, and DNA reparation. The aim of our study was to investigate and analyze the status of methylation of the promoter of SFRP2 gene in patients with hyperplastic processes of the endometrium. Materials and Methods: The study groups were the following: I — patients with endometrial hyperplasia (EH, n = 9); II — patients with endometrial intraepithelial neoplasia (EIN, n = 10), III — control groups: 1) with endometrial cancer (EC, n = 4), and 2) healthy women (n = 4). Determination of promoter methylation of SFRP2 gene was carried out by the semiquantitative method of methylation-specific PCR assay. Results: The maximum level of methylation of SFRP2 gene promoter had been revealed in patients with EC — 42.80 ± 3.55% (р < 0.05). The patients of the I group had the lowest values of methylation of SFRP2 gene promoter — 10.66 ± 0.85%, while in patients of the II group this indicator was higher — 20.60 ± 0.95% (р < 0.05). In healthy women of the control group, methylation of SFRP2 gene promoter was detected in none of the samples. Conclusion: The content of the methylated SFRP2 gene in endometrial tissue of patients with hyperplastic processes higher than 20–25% allows relate these women to the risk group of EC development and dictates the need of intensive observation of such patients. Key Words: methylation, SFRP2 gene, hyperplastic processes of the endometrium. Hyperplastic processes of the endometrium (HPE) are related to the most actual problems in gynecology and require attention of obstetricians-gynecologists due to high risk of a malignization and recurrence [1, 2]. HPE is considered to be the pathology of the en- dometrium, which is characterized by diffuse or focal enlargement of the endometrium, and can arise not only at the background of excessive exposure to estrogen, but also via epigenetic disorders that affect apoptosis, inactivation of cell proliferation, differentiation, cell ad- hesion, DNA repair and as a result, lead to an imbalance of proliferation and apoptosis [3–6]. Also the tendency of “rejuvenation” of this patho- logy is supervised for last years. It is known, that endo- metrial cancer (EC) develops against the background of an endometrial hyperplasia (EH) in about 50% of cases. Different morphological types of the HPE (from a simple EH without atypia to an EC) represent the progressing changes in histo- and cytoarchitecto- nics with accumulation of the nosospecific molecular and genetic changes of cells [7, 8]. An abnormal methylation of DNA is the earliest event, which occurs in cell before the morphological manifestation of an EH. It is revealed that methylation of CpG-islands is the cause of loss of an expression of the corresponding genes due to the blocking of their transcription [7, 9]. Determination of the status of DNA methylation of nosospecific genes helps with early and differential diagnosis of tumors, and also is an impor- tant event for observation and the prognosis. The study [10] showed that methylat ion of FOXP3 gene promoter in patients with EC is around 56–77%. Another study [11] showed that the de- velopment of HPE is not associated with WIF1 gene methylation. SFRPs family secreting proteins are antagonists of a Wnt-regulatory pathway, they suppress this signal- ing pathway in healthy individuals. The Wnt-signaling pathway promotes the regulation of proliferation and differentiation of cells. It is proved that in some malignant tumors, such as a colorectal cancer, tu- mors of head and neck, gastric cancer, methylation of genes-antagonists of a Wnt-signaling pathway is the reason of uncontrollable cellular proliferation [12, 13]. Traditionally, ultrasound, endoscopic and patho- morphological methods of a research are used for diagnostics of HPE [14]. But none of these methods shows an exact assessment; even the discrepancy an atypical hyperplasia and EC in differential diagnos- tics by morphologists constitutes 11–20% of cases [7]. There is a need for search of more reliable, early cri- teria of HPE diagnostics by determination of a condi- tion of DNA methylation. Therefore, research of the methylation status of SFRP2 gene in patients with HPE and patients with EC is actual for modern gynecologic practice. The aim of our study was to investigate and analyze the DNA methylation status of the promoter of SFRP2 gene in patients with HPE. Submitted: January 16, 2017. *Correspondence: E-mail: dimitrovanatalie@gmail.com Abbreviations used: EC — endometrial cancer; EH — endometrial hyperplasia; EIN — endometrial intraepithelial neoplasia; HPE — hyperplastic processes of the endometrium; PE — proliferative endometrium; SE — secretory endometrium. Exp Oncol 2018 40, 2, 109–113 110 Experimental Oncology 40, 109–113, 2018 (June) MATERIALS AND METHODS 27 (100%) patients at the age of 18–76 years, have participated in a research, criteria of inclusion were the following: the informed patient’s consent to par- ticipation in a research; age — reproductive, peri- and postmenopausal; pathomorphologically confirmed diagnosis of HPE. Criteria of an exclusion were the age < 18 years or pregnancy. Involved in the research patients were treated in the Gynecology Department of Multidisciplinary Medical Center University Clinic # 1 of Odesa National Medi- cal University in a planned or urgent order and were operated thereon due to abnormal uterine bleeding, HPE. Diagnoses were confirmed by ultrasound dia- gnostics before an operative intervention. Preoperative examination and preparation of patients were carried out by standard principles according to the order of Ministry of Health Care of Ukraine No. 620 from 29.12.2003. The extent of an operative intervention was chosen individually for each patient. It depended on a clinical situation: a hysteroscopy with a biopsy of endometrium, curettage of a mucous cavity of the uterus, a hysterectomy with/without uterus appenda- ges, pipelle biopsy of the endometrium. The existence of HPE was confirmed pathomorphologically in all pa- tients who participated in a research according to EIN- classification of HPE: EH, endometrial intraepithelial neoplasia (EIN) and classification of histopathologi- cal subtypes of EC: endometrioid adenocarcinoma, mucinous carcinoma, serous carcinoma, clear cell carcinoma, squamous cell carcinoma, undifferentiated carcinoma, mixed carcinoma, metastatic carcinoma [1, 15–17]. Depending on the HPE morphological type, exam- ined patients were distributed into the groups: I) EH — 9 (33.3%) patients; II) EIN — 10 (37.1%) patients; III) control groups: 1) EC — 4 (14.8%) patients, and 2) healthy women — 4 (14.8%). The age of patients of the I group was 18–59 years, among them 6 (66.7%) patients were of reproductive age, 2 (22.2%) patients — of perimenopausal age, 1 (11.1%) patient of postmenopausal age. 3 (33.3%) patients, mainly perimenopausal and postmeno- pausal age, were observed by the therapist because of an idiopathic hypertension. 2 (22.2%) patients had high index of body weight — 29.2; 33.4. A hysteroscopy with a “cold” curettage of endometrium was carried out to 5 (55.6%) patients, indications to which were sterility in 2 (40.0%) cases and HPE according to an ultrasound examination in 3 (60.0%) cases. The hysteroscopy was carried out with the use of the endoscopic equipment Karl Storz (Germany). The fractional diagnostic curet- tage of endometrium was carried out to 3 (33.3%) women, due to an abnormal uterine bleeding. 1 (11.1%) patient underwent a hysterectomy without appendages (basic disease is hysteromyoma with a hemorrhagic syndrome). USE of organs of the small pelvis, which was carried out by the device ALOKA Pro Sound SSD 5000 (Japan), showed disharmony of thickness of en- dometrium to a phase of a menstrual cycle, heteroge- neity and hyperechogenicity of the endometrium. USE of organs of a small pelvis had shown the existence of non-uniform hyperechoic-thickened endometrium (11–19 mm — in reproductive age, 5–11 mm — in post- menopausal period). Also it was established that 1 (11.1%) patients had polycystic ovaries, 3 (33.3%) — hysteromyoma, 1 (11.1%) — adenomyosis. The age of patients of the II group was 39–64 years: 2 (20.0%) patients of reproductive age and 4 (40.0%) patients of perimenopausal and postmenopausal age. 5 (50.0%) women had high index of body weight — 28.3–37.4. 5 (50.0%) patients had normal weight. A half of patients were observed by the therapist because of a hypertension. 7 (70.0%) patients had appealed because of menstrual disorders, which turned into ab- normal uterine bleeding. 3 (30.0%) patients with a dis- ease of endometrium had no symptoms. USE of organs of a small pelvis had shown the existence of non-uniform hyperechoic thickened endometrium (14–23 mm in re- productive age, 9–17 mm — in postmenopausal period). Also ultrasound revealed uterine myoma in 5 (50.0%) women and 1 (10.0%) patient — adenomyosis. 4 (40.0%) patients had an operative intervention — a hysterectomy with appendages, 2 (20.0%) women had a hysteroscopic resection of the endometrium, and 4 (40.0%) patients — the dilation and curettage of the uterus. The age of patients of the control group with EC was 49–72 years. 3 (75.0%) patients were at postmeno- pause, 1 (25.0%) — of reproductive age. The index of body weight of patients with EC was more than 30, that confirmed an obesity; 2 (50.0%) patients were on the reg- ular medical check-up at the therapist because of an id- iopathic hypertension, 1 (25.0%) — under observation of the endocrinologist because of a II type diabetes mel- litus. All patients with EC had complained on menstrual disorders in the form of a heavy irregular menses and ab- normal uterine bleedings. 2 (50.0%) patients underwent the uterus curettage, 2 (50.0%) patients — a hystero- scopy for biopsy of endometrium. According to results of USE of organs of the small pelvis, which were carried out before an operative intervention, all 4 (100%) patients had the enlargement of the endometrium (in reproduc- tive age — 18–28 mm, 11–24 mm — at postmenopausal period), its heterogeneity, in equality of an external con- tour, absence of accurate margins between the tumor center and a myometrium. The hysteromyoma had been diagnosed in 2 (50.0%) patients, and adenomyosis had been diagnosed in 1 (25.0%) patient. The healthy women of the control group (4 (100.0%)) without pathology of the endometrium participated in the study and were examined in the clinic for prepara- tion to the in vitro fertilization program because of male infertility factor. The age of the examined control group was 29–36 years. The absence of the pathology of the endometrium is confirmed morphologically (pipelle biopsy of the endometrium) and by ultrasound of the pelvic organs (M-echo 5–13 mm). Genital and extra- genital pathology in the control group women were not detected. Experimental Oncology 40, 109–113, 2018 (June) 111 Determination of methylation of the DNA promoter of SFRP2 gene was carried out by the semiquantitative method of methylation-specific PCR assay. DNA from samples of endometrium tissues were isolated with use of DNeasy Blood & Tissue Kit (Qiagen, USA). Bisulfite processing of DNA was carried out with using EpiTect Bisulfite Kit (Qiagen, USA) according to the protocol of the manufacturer. The amount of DNA for bisulfite processing of DNA in all tests was 1 µg/ml. Amplification of DNA after bisulfite processing was car- ried out using Hot Start DNA Polymerase Kit according to the program 95 °C — 15 min; 95 °C — 30 s, 50 °C — for a unmethylated DNA and 56 °C — for the methylated DNA, 72 °C — 30 s, 39 cycles; 72 °C — 10 min (Table 1). Table 1. The sequence of primers for amplification of the methylation- specific site of SFRP2 promoter Type Sequence of primers t, °С For methylated SFRP2 gene F_M_GGGTCGGAGTTTTTCGGAGTTGCGC R_M_CCGCTCTCTTCGCTAAATACGACTCG 56 For unmethylated SFRP2 gene F_U_TTTGGGTTGGAGTTTTTTGGAGTTGTGT R_U_AACCCACTCTCTTCACTAAATACAACTCA 50 The PCR products were examined using 2% agarose gel electrophoresis, stained with ethidium bromide. The relative content the methylated and unmethylated DNA was assessed using the Quantity One 1D Analysis Software program (BIO-RAD, USA) on the device Versa Doc МР 4000 System (BIO-RAD, USA) according to the formula: M (%) = A • 100 / (A + B), where A — is the area of peak of methylated DNA, B — is the area of peak of unmethylated DNA, M — relative content the methylated DNA. The molecular-biological studies of the DNA methylation were controled by EpiTech Control DNA unmethylated (Qiagen, USA) and EpiTect Control DNA methylated (Qiagen, USA). Statistical analysis of the data obtained was validated using MedCalc 14.8.1 and Microsoft Excel 2010 packages with the AtteStat add-in 12.5. The average sample values of the quantitative attributes are given as M ± m, where M is the mean selective, m is the mean error. Taking into account the small number of observations in the groups for comparison of the main parameters, nonparametric methods were used — the medication test of Kruskal — Wallis, the Mann — Whitney test and the Wald — Wolfowitz series. RESULTS AND DISCUSSION The analysis of the obtained data on methylation of the promoter of SFRP2 gene has revealed significant differences between the patients with EH, EIN, EC and healthy women (Table 2, Fig. 1, 2). Table 2. The content of methylated DNA of a gene SFRP2 in the studied samples of endometrium Case Morphological type of the endometrium The content of SFRP2 gene methylation, % 1 EH 8 2 EH 12 3 EH 16 4 EH 9 5 EH 11 6 EH 11 7 EH 12 8 EH 8 9 EH 9 10 EIN 22 11 EIN 17 12 EIN 17 13 EIN 19 14 EIN 24 15 EIN 26 16 EIN 23 17 EIN 19 18 EIN 20 19 EIN 19 20 EC 33 21 EC 45 22 EC 49 23 EC 51 24 PE 0 25 PE 0 26 PE 0 27 SE 0 Notе: PE — proliferative endometrium; SE — secretory endometrium. 0 10 20 30 40 50 60 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 % Cases The level of DNA methylation of SFRP2 gene (%) Fig. 1. The level of methylated SFRP2 gene in the studied endometrial samples. Cases 1–9 — patients with EH, 10–19 — patients with EIN, 20–23 — patients with EC, 24–27 — healthy women 112 Experimental Oncology 40, 109–113, 2018 (June) The maximum level of methylation of the stud- ied gene had been found in patients with EC — 42.80 ± 3.55% (р < 0.05), that is nearly by 4-fold higher, than in patients with EH and by 2-fold than in patients with EIN. It was revealed that patients with EH had the lowest values of this index; the av- erage content of the methylated SFRP2 gene was 10.66 ± 0.85%, while in patients with EIN this index was 20.60 ± 0.95% (р < 0.05) (Fig. 1, 2, Table 2). In healthy women of the control group, methylation of the investigated gene was detected in none of the cases, therefore, the graphic representation of the results was not performed (Table 2). It is necessary to note that methylation of the pro- moter of SFRP2 gene didn’t depend on the age of the patients, existence of the accompanying gynecologic pathology (hysteromyoma, adenomyosis, polycystic ovaries). 5 10 15 20 25 30 35 40 45 50 55 Groups Le ve l o f D N A m et hy la tio n of th e SF RP 2 ge ne , % EC EH EIN Fig. 2. Methylation of the promoter of SFRP2 gene in patients with EH, EIN and EC Also, an assessment of the intensity of methylation of the promoter of SFRP2 gene confirmed the results (Fig. 3) shown above. The methylation of DNA in con- trol sample (№ 1) was taken as 50%. In comparison with the control, the minimum intensity of methylation was noted in patients with EH (samples № 3, № 4, № 5). The maximal intensity of DNA methylation was found in patients with EC (samples № 6, № 7), being higher in comparison with patients with EH (№ 3, № 4, № 5) and the EIN (№ 2). Fig. 3. Intensity of methylation of the promoter of SFRP2 gene in endometrial samples from different groups under study. M — methylated DNA; U — unmethylated DNA The dependence between the level of DNA methy- lation and a morphological stage of HPE has shown its lowest level in patients with EH, and the highest — in patients with EC. Average values of DNA methylation were characteristic for patients with EIN. The data on the status of SFRP2 methylation in patients with HPE and EC in the literature are scarce. In the paper of Di Domenico et al. [18] in has been shown that methylation of SFRP2 gene could not serve as a diagnostic criterion for the diagnosis of EC, as it was detected in 2 out of 39 examined patients with HPE and EC. There is a high incidence of methylation of another gene from the Secreted Frizzled Related Protein family, SFRP1, among the EC specimens and this index allow clearly distinguish benign and malignant areas of the mucosal tissue of the uterine cavity. The results of our study showed a high frequency of SFRP2 gene methylation among patients with HPE, with a direct relationship between the degree of methy lation and the morphological type of the endometrium pathology: EH → EIN → EC. There are some data that the state of SFRP2 gene methyla- tion could also be used to diagnosis of oncological processes of other localizations (colorectal, ovarian, lung cancer), not only EC [19–21]. CONCLUSION Thus, the presence of not only morphological changes in case of HPE, but also characteristic changes of SFRP2 methylation in different types of HPE, expands diagnostic criteria of this nosology. Low content of the methylated DNA (10.66 ± 0.85%) in case of EH and high content of the methylated DNA (42.80 ± 3.55%) in patients with EC, allow to use determination of relative content of the methylated SFRP2 gene as a marker of differential diagnostics of HPE and early prognosis of risk of its maligniza- tion. The SFRP2 gene can be used as a marker for the differential diagnosis of HPE and EC. The content of the methylated SFRP2 gene in endometrial tissue of patients with hyperplastic processes higher than 20–25% allows relate these women to the risk group of EC development and dictates the need of intensive observation of such patients. REFERENCES 1. Tatarchuk TF, Kalugina LV, Tutchenko TМ. Hyperplas- tic processes of endometrium: what’s new? Repr Endocrinol 2015; 5: 7–13 (in Russian). 2. Sidorova I, Unanyan A, Vlasov R, et al. Endometrial hyperplastic processes: clinical and therapeutic features. Doc- tor 2011; 6: 58–60 (in Russian). 3. Gulyaeva LF, Krasilnikov SE. Molecular mechanisms of endometrial carcinoma. Bull ESSC SD RAMS 2012; 3: 110–5 (in Russian). 4. Delpu Yа, Cordelier P, C. Cho W. DNA methylation and cancer diagnosis. Int J Mol Sci 2013; 14: 15029–58. 5. Gros C, Fahy J, Halby L, et al. DNA methylation in- hibitors in cancer: Recent and future approaches. Biochimie 2012; 94: 2280–96. 6. Sivova EN, Pachov АI, Bukreev AV, Fokina AP. Some questions of etiology and pathogenesis of endometrial prolif- erative processese. Siber Med Rev 2015; 1: 16–22 (in Russian). 7. Stanoyevich IV, Zemlyakova VV, Fen I, et al. Abnormal methylation of a number of genes in endometrial hyperplasia in the presence of chronic endometritis. Russ Bull Obst Gy- necol 2012; 1: 20–3 (in Russian). 8. Matias-Guiu X, Catasus L, Bussaglia E, et al. Molecular pathology of endometrial hyperplasia and carcinoma. Hum Pathol 2001; 32: 569–77. Experimental Oncology 40, 109–113, 2018 (June) 113 9. Prat J, Gallardo A, Cuatrecasas M, et al. Endometrial carcinoma: pathology and genetics. Pathology 2007; 39: 72–87. 10. Buchynska LG, Iurchenko NP, Verko NP, et al. FOXP3 gene promoter methylation in endometrial cancer cells. Exp Oncol 2015; 4: 246–9. 11. Zaporozhan VN, Dubinina VG, Bubnov VV, et al. Analysis of gene WIF1 methylation in women with hyperprolif- erative processes of endometrium and endometrial carcinoma. Ach Biol Med 2015; 2: 55–7 (in Russian). 12. Ma XY, Ma CX, Wang JN. Endometrial carcinogen- esis and molecular signaling pathways. Am J Mol Biol 2014; 4: 134–49. 13. Komiya Y, Habas R. Wnt signal transduction pathways. Organogenesis 2008; 4: 68–75. 14. Zaporozhan VN, Tatarchuk TF, Dubinina VG, et al. Modern diagnostics and treatment of endometrial hyperplastic processes. Repr Endocrinol 2012; 1: 5–12 (in Russian). 15. Khanna R, Rupala G, Khanna V, et al. Endometrial intraepithelial neoplasia and its correlation with WHO classi- fied endometrial hyperplasia. Int J Pathol 2010; 1: 1–4. 16. Ordi J, Bergeron C, Hardisson D, et al. Reproducibility of current classifications of endometrial endometrioid glan- dular proliferations: further evidence supporting a simplified classification. Histopathology 2013; 64: 284–92. 17. Salman MC, Usubutun A, Boynukalin K, Yuce K. Com- parison of WHO and endometrial intraepithelial neoplasia clas- sifications in predicting the presence of coexistent malignancy in endometrial hyperplasia. J Gynecol Oncol 2010; 21: 97–101. 18. Di Domenico M, Santoro A, Ricciardi C, et al. Epigenetic fingerprint in endometrial carcinogenesis: the hypothesis of a uterine field cancerization. Cancer Biol Ther 2011; 5: 447–57. 19. Shunlin L, Xiaoying C, Ruhua C, et al. Diagnostic role of Wnt pathway gene promoter methylation in non small cell lung cancer. Oncotarget 2017; 22: 36354–67. 20. Ashktorab H, Brim H. DNA methylation and colorec- tal cancer. Curr Colorectal Cancer Rep 2014; 10: 425–30. 21. Nikbakht M, Shabanizadeh A, Salehi M, et al. BRCA1 promoter methylation status in ovarian cancer. Lab Med 2012; 43: 18–21. Copyright © Experimental Oncology, 2018