• 생명과학회지
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• 제23권10호
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• pp.1183-1191
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• 2013

APEX-1 (인간 apyrimidinic/apurinic 효소)은 염기성 사이트 및 DNA단일 가닥 결손으로 손상된 DNA을 복구 할 수 있는 다기능 단백질이다. 또한 APEX-1은 많은 전사 인자들의 redox-modifying factor (산화 환원 수정 요소)로서의 역할을 한다고 알려져 있다. 이런 APEX-1의 전사 타겟을 동정하는 것은 APEX-1의 다양한 세포 내 작용 메커니즘을 이해하는데 필수적이다. 따라서 이 논문에서는 먼저 Expression array analysis를 통해 glial cell-derived neurotropic factor receptor ${\alpha}1$ ($GFR{\alpha}1$)을 동정하였다. $GFR{\alpha}1$은 glial cell-derived neurotropic factor (GDNF) family 수용체이며 APEX-1에 의해 발현이 증가된다. APEX-1이 과발현된 세포에서 GDNF처리에 의해 GDNF/$GFR{\alpha}1$ 시그널 타겟인 c-Src가 Tyr418잔기에서 인산화 됨을 관찰하였다. 또한 APEX-1이 과발현된 세포에 GDNF처리하면, 세포증식이 증가함을 보았다. 반면, APEX-1 발현을 siRNA을 이용하여 감소시키면 $GFR{\alpha}1$ 발현과 GDNF에 의한 c-Src 인산화 및 세포증식이 감소함을 확인하였다. 이상의 결과는 APEX-1은 GDNF/$GFR{\alpha}1$ 시그널을 통해 세포 생존과 증식을 조절함을 증명하였다. 따라서 본 연구를 통해 APEX-1의 세포 증식을 조절하는 새로운 기전을 규명하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권18호
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• pp.7589-7595
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• 2014

Apurinic/apyrimidinic endonuclease 1 (APEX1) is a multifunctional protein which plays a central role in the BER pathway. APEX1 gene being highly polymorphic in cancer patients and has been indicated to have a contributive role in Apurinic/apyrimidinic (AP) site accumulation in DNA and consequently an increased risk of cancer development. In this case-control study, all exons of the APEX1 gene and its exon/intron boundaries were amplified in 530 breast cancer patients and 395 matched healthy controls and then analyzed by single-stranded conformational polymorphism followed by sequencing. Sequence analysis revealed fourteen heterozygous mutations, seven 5'UTR, one 3'UTR, two intronic and four missense. Among identified mutations one 5'UTR (rs41561214), one 3'UTR (rs17112002) and one missense mutation (Ser129Arg, Mahjabeen et al., 2013) had already been reported while the remaining eleven mutations. Six novel mutations (g.20923366T>G, g.20923435G>A, g.20923462G>A, g.20923516G>A, 20923539G>A, g.20923529C>T) were observed in 5'UTR region, two (g.20923585T>G, g.20923589T>G) in intron1 and three missense (Glu101Lys, Ala121Pro, Ser123Trp) in exon 4. Frequencues of 5'UTR mutations; g.20923366T>G, g.20923435G>A and 3'UTR (rs17112002) were calculated as 0.13, 0.1 and 0.1 respectively. Whereas, the frequency of missense mutations Glu101Lys, Ser123Trp and Ser129Arg was calculated as 0.05. A significant association was observed between APEX1 mutations and increased breast cancer by ~9 fold (OR=8.68, 95%CI=2.64 to 28.5) with g.20923435G>A (5'UTR), ~13 fold (OR= 12.6, 95%CI=3.01 to 53.0) with g.20923539G>A (5'UTR) and~5 fold increase with three missense mutations [Glu101Lys (OR=4.82, 95%CI=1.97 to 11.80), Ser123Trp (OR=4.62, 95%CI=1.7 to 12.19), Ser129Arg (OR=4.86, 95%CI=1.43 to 16.53)]. The incidence of observed mutations was found higher in patients with family history and with early menopause. In conclusion, our study demonstrates a significant association between germ line APEX1 mutations and breast cancer patients in the Pakistani population.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권1호
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• pp.8-18
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• 2006

Purpose: The purpose of this study was to verify that the expressions of angiogenin, transforming growth factor-beta(TGF-${\beta}$), vascular endothelial growth factor(VEGF), human apurinic/apyrimidinic endonuclease(APEX) and tumor necrosis factor-alpha(TNF-${\alpha}$) were associated with the tumorigenesis of the oral squamous cell carcinoma(OSCC). Materials and Methods: Fifty-one samples of OSCC and fifteen normal oral mucosae were obtained to analyze the expression levels of above five factors. mRNA expressions were quantified by the quantitative competitive PCR(QC-PCR) method. After 2% agarose gel electrophoresis stained with ethidium bromide, the concentration of mRNA was calculated by a digital image analysis system. The expression levels of angiogenin, TGF-${\beta}$, VEGF, APEX and TNF-${\alpha}$ were compared by unpaired Student's t-tests between cancer and normal tissues. We analyzed statistically to find the cut-off values that would be useful as diagnostic markers, and the linear regression analysis between every two factors of these five factors by SAS system. Results: All of these five factors (angiogenin: P<0.0037, TGF-${\beta}$: P<0.0001, VEGF: P<0.0102, APEX: P<0.0023, TNF-${\alpha}$: P<0.0074) were significantly correlated with OSCC. In the analysis to find the cut-off values for the diagnosis, we could not find any value that had a reasonable sensitivity and specificity. In the linear regression analysis, there were correlations between angiogenin and TNF-${\alpha}$, TGF-${\beta}$ and VEGF, TGF-${\beta}$ and APEX, TGF-${\beta}$ and TNF-${\alpha}$, VEGF and APEX, VEGF and TNF-${\alpha}$, APEX and TNF-${\alpha}$. Conclusion: Our results suggest that not only angiogenin, TGF-${\beta}$, VEGF, APEX and TNF-${\alpha}$ are significantly associated with the tumorigenesis, but also the close relationship between these factors might enhance the tumorigenesis of OSCC. We can not find clinical availability for diagnosis.