YUMURTALIK KANSERLİ HASTALARIN PERİFERİK DOLAŞIMINDA YÜKSEK MİR-27A-3P DÜZEYİ

Kadınların çoğunda yumurtalık kanseri tanısı, erken evrede asemptomatik olması ve yeterlierken teşhis tarama yöntemlerinin bulunmaması sebebiyle ileri evrede tanı almaktadır.Yumurtalık kanserinin erken tanısı, tedavisi ve takibi için hastalığın moleküler patogenezininaçıklanması gerekmektedir. Bu sayede yeni biyolojik belirteçlere gereksinim duyulmaktadır.MikroRNA'lar, post-transkripsiyonel seviyede gen ekspresyonunu düzenleyen küçük (18-25nükelotid uzunluğunda) kodlayıcı olmayan RNA molekülü sınıfıdır. miRNA’larınonkogenezde hücre çoğalmasını, hücre farklılaşmasını ve onkogen veya tümör baskılayıcıolarak apoptozu düzenleyerek çok önemli bir işlevleri olduğu bilinmektedir. Yumurtalıkkanseri oluşumunda çok sayıda miRNA’nın değişiklik gösterdiği bildirilmiş ve bu genlerinbazılarının tanı, prognoz ve tedavi için ideal hedefler olabileceği gösterilmiştir. Çalışmadayumurtalık kanserinde önemli olduğu saptanan miRNA’lar arasından seçilen miR-27a-3p’ninekspresyon düzeyi, yumurtalık kanserli hastalarda ve sağlıklı kişilerin periferik kanında araştırıldı. RT-PCR tekniği kullanılarak yapılan ekspresyon analizi SPSS v21.0 programıkullanılarak istatiksel olarak değerlendirildi. Mann-WhitneyU testi sonucunda sağlıklıkontroller ile yumurtalık kanserli hasta grupları arasında miR-27a-3p ekspresyonu açısındanbelirgin bir farkın olduğu saptandı. Yumurtalık kanseri hastalarında kontrol grubuna göremiR-27a-3p ekspresyonunun 1,95 kat arttığı ve istatistiksel açıdan anlamlı (p<0,05) olduğugörüldü. Literatürde, miR-27a-3p’nin yumurtalık kanseri dahil birçok kanser türünün doku vehücrelerinde aşırı eksprese edildiği bildirilmiş olmakla beraber, yumurtalık kanserli hastalarınperiferik dolaşımda miR-27a-3p seviyesindeki artış ilk kez bu çalışma ile gösterilmiştir.Çalışmamızda ilave olarak miR-27a-3p molekülünün yumurtalık kanseri için biyolojikbelirteç olma potansiyeli yapılan ROC analizi ile de kanıtlanmıştır. Özetle, periferikdolaşımdaki miR-23a-3p’nin yüksek ekpresyonunun yumurtalık kanserinin erken tanısındatedavinin izlenmesinde hatta yumurtalık kanseri için terapötik bir hedef olarakkullanılabileceğini düşündürmektedir

miRNA Sequence Analysis in Patients With Kaposi’s Sarcoma-Associated Herpesvirus

MicroRNAs (miRNAs) are the non-coding RNAs that can both attach to the untranslated and coding sections of target mRNAs, triggering destruction or post-transcriptional alteration. miRNAs regulate various cellular processes such as immune function, apoptosis, and tumorigenesis. About 35,000 miRNAs have been discovered in the human genome. The increasing evidence suggests that the dysregulation of human miRNAs may have a role in the etiology of some disorders including cancer. Only a small sub-set of human miRNAs has functionally been validated in the pathogenesis of oncogenic viruses such as Kaposi’s sarcoma-associated herpesvirus (KSHV). KSHV is the cause of various human malignancies including primary effusion lymphoma (PEL) and Kaposi’s sarcoma (KS), which are mainly seen in AIDS patients or other immunocompromised people. We aimed to identify the miRNAs in Kaposi’s sarcoma cases, with the comparison of KSHV seropositive and seronegative tumors with the controls and in each other in Turkish Kaposi’s sarcoma patients. We performed the miRNA-sequencing at genome level in the peripheral blood mononuclear cells of 16 Kaposi’s sarcoma patients, and in 8 healthy controls matched for age, gender, and ethnicity. A total of 642 miRNA molecules with different expression profiles were identified between the patients and the healthy controls. Currently, out of 642 miRNAs, 7 miRNAs (miR-92b-3p, miR-490-3p, miR-615-3p, miR-629-5p, miR-1908, miR-3180, miR-4433b-3p) which have not been described in the literature in the context of Kaposi’s sarcoma were addressed in the study for the first time and 9 novel miRNAs, not found previously in the database, have been detected in Kaposi’s sarcoma using the miRNA-sequencing technique. This study demonstrates the identification of differently expressed miRNAs which might be the new therapeutic targets for Kaposi’s sarcoma, that has limited treatment options and can be used in the etiology, diagnosis, and prognosis of this cancer

Methylation Changes of Primary Tumors, Monolayer, and Spheroid Tissue Culture Environments in Malignant Melanoma and Breast Carcinoma

Epigenetic changes have major role in the normal development and programming of gene expression. Aberrant methylation results in carcinogenesis. The primary objective of our study is to determine whether primary tumor tissue and cultured tumor cells in 2D and 3D tissue culture systems have the same methylation signature for PAX5, TMPRSS2, and SBDS. These findings will play an important role in developing in vitro model system to understand the effect of methylation inhibitors on primary tumor tissue. In a previous study PAX5, TMPRSS2, and SBDS genes that we are investigating were reported to be methylated more than 60% in breast cancer and malignant melanoma cell lines. However, these genes have never been studied in primary tumor tissues. Thus, primary tumor tissues of breast cancer and malignant melanoma were first grown in 2D and 3D cultures. Then these two types of tumor tissues and their 2D and 3D cultures were investigated for changes considering methylation levels in PAX5, TMPRSS2, and SBDS genes using real-time polymerase chain reaction. No differences were observed in the primary tissues and culture systems for both PAX5 and TMPRSS2 in malignant melanoma tissues. We found that PAX5 gene was an efficient marker to measure the effects of methylation inhibitors for in vitro systems for malignant melanoma tissue

HIGH miR-142-3p EXPRESSION IN PERIPHERAL BLOOD OF PATIENTS WITH OVARIAN CARCINOMA

Objectives: The fact that ovarian cancer manifests itself in the late stage and is characterized by a poor prognosis, is caused death in the majority of cases. miRNAs being as the biomarker candidates in diagnosis, and their use in treatment as the inhibitors of the molecules mimicking the miRNA showed that they may be used as the new therapeutic target and agents. Present study aims to determine the effect of expresion level of miR-142-3p in ovarian cancer patients. Material-Methods: We detected with our group in our prior study conducted with disconcordant ovarian cancer twins that many miRNA molecules were different in ovarian cancer compared with the molecules in healthy sibling. The expression level of miR-142-3p that was selected from the miRNAs detected in the previous study was compared, and investigated in a wider ovarian cancer group, and in healthy control group. miR-142-3p expression level was investigated using the real-time PCR method in the present study involving 147 patients, and 100 healthy control group. The differences in the expression levels of miR-142-3p detected in the peripheral blood lymphocytes of ovarian cancer patients, and healthy control were statisticaly evaluated. Results: The expression level of miR-142-3p was detected to have increased 3.11 fold in ovarian cancer patients compared with the levels in healthy controls, and the difference was statistically significant (p:0.00). We suggest that this microRNA showing high expression promoted the oncogenesis of ovarian cells by behaving such an oncogene. miR-142-3p expression level, and the clinical data,diagnosis, and family histories were analysed in details. Conclusions: These results suggest that miR-142-3p that was found significantly increased in the peripheral blood samples of ovarian cancer patients compared with the healthy controls might be used as a sensitive, noninvasive biomarker in the early diagnosis, and treatment and follow up of ovarian cancer

EVALUATING THE METHYLATION STATUS OF RB1 GENE PATIENTS WITH RETINOBLASTOMA

OBJECTIVES: The most frequently diagnosed malignant ocular tumor of infancy and childhood is Retinoblastoma. Due to the mutation on the q14 on chromosome 13 causes the retinoblastoma. There are two types of basic gene mutations: genetic and sporadic. This cancer is initiated by RB1 mutation, responsible for the cell cycle regulation and genome stability in the cells of the retina in children under 5 years old. The retinoblastoma comprises about 40% inherited mutations, 10% of germline mutations of RB1 inherited from an affected parent, and 30% from de-novo germline mutations. MATERIAL&METHODS: Methylation of the RB1 gene on promoter region is unknown. The results obtained by MLPA analysis and sequence analysis were investigated for RB1 gene methylation in patients without RB1 mutation. The methylation determination is done with OneStep qMethyl-PCR Kit using a Real-Time PCR system. Methylation changes were investigated in peripheral blood samples of 60 patients with retinoblastoma, 18% of the patients (11/60) had bilateral and 82% of patients (49/60) had unilateral disease and 52 healthy controls. RESULTS: The mean methylation levels of 60 retinoblastoma patients and 52 healthy controls were 35% and 34%, respectively. Mann Whitney U test was compared between the patient and healthy controls and no statistically significant difference was detected between the two groups (p = 0.882). CONCLUSIONS: The promoter methylation levels in RB1 gene patients having familial history was believed to be large deletion and duplication and small indel absence mutations in the RB1 gene are not effective especially in the etiology of heritable retinoblastoma. Keywords: Retinoblastoma, RB1 gene mutation, Promoter Methylatio

Metastatik Akciğer Kanserli Hastaların Periferik Kanında Yeni Aday Biyomarker: Yüksek DICER1 Ekspresyon Düzeyi

Amaç: Akciğer kanseri, dünyada kansere bağlı insidans ve mortalite açısından birinci sırada yer almaktadır. Kanserin multifaktoriyel bir hastalık olması nedeniyle kanserle ilişkili mekanizmaların aydınlatılmaya çalışılması oldukça önem taşımaktadır. Kanserle yakından ilgili olan miRNA aktivitesinin çeşitli mekanizmalarla bozulduğu bilinmektedir. Bu mekanizmalardan biri de miRNA işlenmesi sırasında meydana gelen moleküler değişikliklerdir. DICER1, microRNA biyogenezinde önemli bir yere sahiptir. Çalışmamızda, akciğer kanserli hastaların periferik kan lenfositlerinde DICER1 gen ifade düzeyinin sağlıklı kişilerle karşılaştırılarak metastatik akciğer kanseri gelişimindeki etkisinin araştırılması amaçlanmıştır. Materyal ve Metot: Çalışma grubu yeni tanı almış ve daha önce hiç tedavi görmemiş 47 akciğer kanserli hasta ile 45 sağlıklı kişinin periferik kan örneklerinden oluşturuldu. Araştırılan DICER1 hedef geni, HPRT1 referans geni ile eş zamanlı olarak Gerçek-Zamanlı PCR yöntemiyle incelendi. Akciğer kanser hastalarına ait gen ekspresyon düzeyi ile sağlıklı kişilerden oluşan kontrol grubu DICER1 gen ekspresyon sonuçları karşılaştırıldı. Sonuçlar 2-ΔΔCT metodu kullanılarak değerlendirildi. Sonuçlar: Akciğer kanser hastalarının periferik kan lenfositlerinde DICER1 gen ifade düzeyinin (2-ΔΔCt) kontrol grubuna göre 1,756 kat arttığı, bu artmış ekspresyon düzeyinin istatistiksel açıdan anlamlı (p< 0,05) olduğu görüldü. Tartışma: Metastatik akciğer kanserli hastaların periferik kan lenfositlerinde yapılan çalışmamızdan çıkan sonuçlar literatürde tümör dokusunda yapılan çalışma ile korelasyon göstermektedir. Bu bağlamda periferik kan lenfositlerindeki DICER1 ekspresyon düzeyinin, metastatik akciğer hastalarının tümör dokusundaki DICER1 gen ekspresyon düzeyi hakkında bilgi vereceğini ve dokusuna ulaşılamayan hastalar için iyi bir uygulama olacağını düşündürmektedir. Ayrıca çalışma literatürde akciğer kanserli hastaların periferik kan örneklerinde DICER1 ekspresyonunun araştırıldığı ilk çalışma niteliği taşımaktadır

Evaluation of BRCA1/2 Gene Mutations in Patients With High-Risk Breast and/or Ovarian Cancer in Turkey

Objectives To find BRCA1/2 test selection criteria unique to the Turkish population, as well as to provide the BRCA1/2 gene mutation distributions of patient population to the literature. Methods Genetic counseling was given to 2,373 cases with a family history of high-risk breast and/or ovarian cancer who applied to Istanbul University, Oncology Institute, Department of Cancer Genetics between 1994 and 2021 and selected by NCCN Guidelines for the BRCA1/2 test criteria. In our clinic, mutation screenings in BRCA1/2 genes were performed by Sanger sequencing method in patients admitted between 1994 and 2014 and by NGS method in patients admitted between 2015 and 2021. Results The overall mutation rate in our patient group selected from high-risk patients was 16.5% (391/2,373) after BRCA1/2 gene mutation screening performed in 2,373 cases who applied to the Cancer Genetics clinic. Of the patients with mutations, 57.5% (225/391) had BRCA1 mutation, 41.9% (164/391) had BRCA2 mutation, and 0.6% (2/391) had both BRCA1 and BRCA2 pathogenic mutations. People diagnosed before the age of 60 who have a history of triple-negative breast cancer had a 28.5% overall mutation rate. Conclusions BRCA1/2 mutation in Turkish population were evaluated in accordance with NCCN BRCA1/2 genetic test selection criteria; we discovered that all of our study results were statistically significant (p<0.05)