Serpil TAHERİ, Yusuf ÖZKUL, Nazife TAŞÇIOĞLU, Çetin SAATÇİ

Gastrointestinal sistem kanserlerinde metilenterahidrofolat redüktaz geni 677C -- t polimorfizminin incelenmesi

Metilentetrahidrofolat redüktaz (MTHFR) geni folat metobolizmasının anahtar rolü oynayan genlerindendir. MTHFR geninde 677C-+T polimorflzmi en yaygın görülen polimorfızimdir. Çalışmamızda gastrointestinal sistem(GİS) kanserli hastalarda;MTHFR geni 677C->T polimorfıziminin araştırılması amaçlandı.Bu amaçla GİS kanserli 64 hastanın (41 kolon ve 23 mide karsinomlu vaka) ve 40 sağlıklı kontrolün periferal kan örnekleri alınarak DNA izolasyonu yapıldı. MTHFR geninde 677C-+T polimorflzmi PCR RFLP yöntemi kullanılarak belirlendi. 64 GİS kanserli hastada MTHFR 677CC, 677CT, 677TT genotipleri sırasıyla 26(%41), 31(% 48), 7(%11); kontrol grubunda ise 15(%37.5), 23(% 57,5), 2(%5) olarak tespit edildi. GİS kanserlerinde MTHFR 677TT(homozigot mutant) genotipi kontrol grubuyla karşılaştırıldığında yaklaşık iki kat artmış olarak bulundu.Sonuçlar Ki Kare testi ile değerlendirildiğinde gruplar arasında anlamlı fark bulunamadı(P>0,05) Gruplar arası farkın istatistiksel anlam ifade etmemesinin çalışma gurubunun küçüklüğünden kaynaklandığı dolayısıyla MTHFR 677C-+T polimorfızminin GİS kanserlerinde önemli olabileceği düşünülmüştür. Sonuç olarak; geniş hasta grubuna sahip ileri çalışmalarda bu gen polimorfızmininaraştırılmasınıngerektiği kanısındayız.

The investigation of methylenetetrahydrofolate reductase gene 677C $rightarrow$ polymorphism in gastrointestinal cancer

Methylenetetrahydrofolate reductase (MTHFR) gene plays a key role in folate metabolism. The most common polymorphism in MTHFR gene is 677C-+T substitution. In our study, peripheral blood samples were obtained from 64 Gastrointestinal (GIS) cancer (41 colon and 23 stomach cancers) cases and 40 healthy controls and DNA was extracted from these samples. MTHFR 677C-^ T variant allele was determined by PCR-RFLP assay. Frequencies of MTHFR 677CC, 677CT and 677TT genotypes were 26 (%41), 31 (%48) and 7 (%11) in the GIS cancer's cases and 15 (%37,5), 23 (%57,5) and 2 (%5) in the controls. MTHFR 677TT (homozygous) genotype was found approximately two fold increased in GIS cancers when compared with control group. However, no significant difference were found between these groups according to Chi Square test (p>0,05). It is thought that differences between these groups don't mean statistical value due to insufficient number of subjects. Therefore, MTHFR 677C~>T polymorphism can be very important in GIS carcinomas. As a conclusion, we think there is a need for research of this polymorphism in larger populations.

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