• Asian Pacific Journal of Cancer Prevention
• /
• 제16권8호
• /
• pp.3293-3299
• /
• 2015

Background: Arm protein lost in epithelial cancers, on chromosome X (ALEX) is a novel subgroup within the armadillo (ARM) family, which has one or two ARM repeat domains as opposed to more than six-thirteen repeats in the classical Armadillo family members. Materials and Methods: In the study, we explore the biological functions of ALEX1 in breast cancer cells. Overexpression of ALEX1 and silencing of ALEX1 were performed with SK-BR3 and MCF-7 cell lines. Cell proliferation and colony formation assays, along with flow cytometry, were carried out to evaluate the roles of ALEX1. Results: ALEX1 overexpression in SK-BR3 breast cancer cells inhibited proliferation and induced apoptosis. Furthermore, depletion of ALEX1 in MCF-7 breast cancer cells increased proliferation and inhibited apoptosis. Additional analyses demonstrated that the overexpression of ALEX1 activated the intrinsic apoptosis cascades through up-regulating the expression of Bax, cytosol cytochrome c, active caspase-9 and active caspase-3 and down-regulating the levels of Bcl-2 and mitochondria cytochrome c. Simultaneouly, silencing of ALEX1 inhibited intrinsic apoptosis cascades through down-regulating the expression of Bax, cytosol cytochrome c, active caspase-9, and active caspase-3 and up-regulating the level of Bcl-2 and mitochondria cytochrome c. Conclusions: Our data suggest that ALEX1 as a crucial tumor suppressor gene has been involved in cell proliferation and apoptosis in breast cancer, which may serve as a novel candidate therapeutic target.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권12호
• /
• pp.4969-4976
• /
• 2014

Background: miR-152 is involved in the genesis and development of several malignancies. However, its role in HCC has not been fully clarified. The aim of this study was to investigate the clinicopathological significance of miR-152 and its effect on the malignant phenotype of HCC cells. Methods: miR-152 expression was detected using real-time quantitative RT-PCR in 89 pairs of HCC formalin-fixed paraffin-embedded and their adjacent tissues. Functionally, in vitro effects and mechanisms of action of miR-152 on proliferation, viability, caspase activity, apoptosis and motility were explored in HepG2, HepB3 and SNU449 cells, as assessed by spectrophotometry, fluorimetry, fluorescence microscopy, wound-healing and Western blotting, respectively. Results: miR-152 expression in HCC was downregulated remarkably compared to that in adjacent hepatic tissues. miR-152 levels in groups of advanced clinical stage, larger tumor size and positive HBV infection, were significantly lower than in other groups. A miR-152 mimic could suppress cell growth, inhibit cell motility and increase caspase activity and apoptosis in HCC cell lines. Furthermore, Western blotting showed that the miR-152 mimic downregulated Wnt-1, DNMT1, ERK1/2, AKT and TNFRS6B signaling. Intriguingly, inverse correlation of TNFRF6B and miR-152 expression was found in HCC and bioinformatics confirmed that TNFRF6B might be a target of miR-152. Conclusions: Underexpression of miR-152 plays a vital role in hepatocarcinogenesis and lack of miR-152 is related to the progression of HCC through deregulation of cell proliferation, motility and apoptosis. miR-152 may act as a tumor suppressor miRNA by also targeting TNFRSF6B and is therefore a potential candidate biomarker for HCC diagnosis, prognosis and molecular therapy.

• Tuberculosis and Respiratory Diseases
• /
• 제54권6호
• /
• pp.610-620
• /
• 2003

연구배경 : 폐암에서 가장 흔한 염색체 결손부위인 3p14.2 결손에 따른 FHIT 자체 기능 즉 암억제 기능의 소실이 폐암의 형성과정에 중요한 기능이 있으리라 생각된다. 흡연 여부, 병리조직학적, TNM 병기 진행에 따른 FHIT 소실여부를 확인하고, 또 흡연및 생존률과의 관계, FHIT의 기능 특히 암 세포의 세포고사, 세포분열에 미치는 영향을 확인하였다. 방 법 : 원발성 비소세포 폐암으로 근치적 절제술을 시행 받은 83례의 paraffin 보관 병리 조직을 절편하여 면역조직화학염색법으로 FHIT의 소실 여부를 확인한 후, 여러 임상적 인자들과의 관계를 파악하고, 유식세포 분석법에 의해, sub-G1 peak로서 세포고사의 정도를, S-phase fraction과 G1-phase fraction으로서 세포분열주기에 미치는 영향을 확인하였다. 결 과 : 전체 83례 중 36례(43%)에서 FHIT가 소실되었고, FHIT 소실율이 편평상피암 52%, 선암 22%; TNM I병기 30%, II병기 48%, III 병기 69%; 흡연경험자 54%, 비흡연자 22%로서, 선암보다는 편평상피암에서, TNM 병기가 진행할수록, 흡연의 경험이 있을수록 FHIT 소실율이 높았다. FHIT 소실군과 발현군의 중간 생존기간은 24개월, 25개월, 2년 생존율은 44%, 51%로서 FHIT 소실여부에 따른 생존율의 차이는 없었다. 세포고사율은 FHIT 소실군과 발현군에서 각각 50.72(${\pm}13.93$)%, 59.38(${\pm}14.33$)%로서 유의한 차이가 있었으며, FHIT 소실군과 발현군에서의 S-phase fraction은 각각 13.93(${\pm}7.35$)%, 15.65(${\pm}6.59$)% G1-phase fraction은 각각 51.50(${\pm}23.15$)%, 54.16(${\pm}20.25$)%로서 각 군간의 유의한 차이는 없었다. 결 론 : FHIT는 인체의 비소세포 폐암의 43%에서 소실되었고, 흡연의 경험이 있을수록, 선암보다는 편평상피암일수록, TNM 병기가 진행할수록 유의하게 FHIT 소실이 높았고, FHIT 소실여부에 따른 생존율의 차이는 없었다. FHIT 소실군에서 발현군보다 세포고사율이 유의하게 낮았으며, S 및 $G_1$ phase fraction의 차이는 없었다.

• 생명과학회지
• /
• 제15권5호
• /
• pp.802-808
• /
• 2005

사람의 Disabled-2 (Dab2)는 정상세포에서 c-Fos의 발현을 억제하여 세포 성장을 조절하는 암억제 유전자로 추정되어 지고 있다. 많은 암세포에서 Dab2는 유방과 난소의 정상세포에서는 발현이 되지만, 약 $85\%$의 유방과 난소의 종양세포에서는 발현이 줄어들거나, 발현이 억제되는 것으로 알려져 있다. 본 연구에서는 bisulfite 반응에 의한 염기서열 분석법과 MSP방법 등을 이용하여 유방암 세포주인 MDA MB-231세포에서 Dab2 유전자의 promoter상에 존재하는 Cpg island의 methylation된 상태를 분석하였다. 그 결과, 사람의 정상 자궁내막세포에서는 Dab2 promoter 부위가 완전하게 methylation되어 있지 않았다. 그러나 MDA MB-231세포에서는 TATA box 근처 의 CpG dinucleotide에서 비정상적으로 methylation되어 있었다. 이런 비정상적인 CpG dinucleotide의 methylation은 MDA MB-231세포를 5-azacytidine으로 처리하였을 때 methylation이 풀리고, Dab2의 발현이 회복되는 것으로 나타났다. 따라서 인간 유방암 세포주인 MBA MB-231세포에서 Dab2의 발현억제는 Dab2 유전자의 promoter부위의 CpG island의 비정상적인 methylation과 관련이 있는 것으로 여겨진다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권11호
• /
• pp.6721-6726
• /
• 2013

Background: Changes in DNA methylation patterns are believed to be early events in hepatocarcinogenesis. A better understanding of methylation states and how they correlate with disease progression will aid in finding potential strategies for early detection of HCC. The aim of our study was to analyze the methylation frequency of tumor suppressor genes, P14, P15, and P73, and a mismatch repair gene (O6MGMT) in HCV related chronic liver disease and HCC to identify candidate epigenetic biomarkers for HCC prediction. Materials and Methods: 516 Egyptian patients with HCV-related liver disease were recruited from Kasr Alaini multidisciplinary HCC clinic from April 2010 to January 2012. Subjects were divided into 4 different clinically defined groups - HCC group (n=208), liver cirrhosis group (n=108), chronic hepatitis C group (n=100), and control group (n=100) - to analyze the methylation status of the target genes in patient plasma using EpiTect Methyl qPCR Array technology. Methylation was considered to be hypermethylated if >10% and/or intermediately methylated if >60%. Results: In our series, a significant difference in the hypermethylation status of all studied genes was noted within the different stages of chronic liver disease and ultimately HCC. Hypermethylation of the P14 gene was detected in 100/208 (48.1%), 52/108 (48.1%), 16/100 (16%) and 8/100 (8%) among HCC, liver cirrhosis, chronic hepatitis and control groups, respectively, with a statistically significant difference between the studied groups (p-value 0.008). We also detected P15 hypermethylation in 92/208 (44.2%), 36/108 (33.3%), 20/100 (20%) and 4/100 (4%), respectively (p-value 0.006). In addition, hypermethylation of P73 was detected in 136/208 (65.4%), 72/108 (66.7%), 32/100 (32%) and 4/100 (4%) (p-value <0.001). Also, we detected O6MGMT hypermethylation in 84/208 (40.4%), 60/108 (55.3%), 20/100 (20%) and 4/100 (4%), respectively (p value <0.001. Conclusions: The epigenetic changes observed in this study indicate that HCC tumors exhibit specific DNA methylation signatures with potential clinical applications in diagnosis and prognosis. In addition, methylation frequency could be used to monitor whether a patient with chronic hepatitis C is likely to progress to liver cirrhosis or even HCC. We can conclude that methylation processes are not just early events in hepatocarcinogenesis but accumulate with progression to cancer.

• Journal of Acupuncture Research
• /
• 제21권2호
• /
• pp.41-55
• /
• 2004

Objective : To investigate the possible molecular mechanism (s) of melittin as a candidate of anti-cancer drug, we examined the effects of the compound on the growth of human lung carcinoma cell line A549. Methods : Growth inhibitory study, flow cytometry analysis, SDS-polyacrylamide gel electrophoresis and Western blot analysis, RT-PCR and in vitro caspases activity assay were performed. Results : Melittin treatment declined the cell viability of A549 cells in a concentration-dependent manner, which was associated with induction of apoptotic cell death. Melittin treatment down-regulated the levels of Bcl-XS/L mRNA and protein expression of A549 cells, an anti-apoptotic gene, however, the those of Bax, a pro-apoptotic gene, were up-regulated. Melittin induced the proteolytic cleavage and activation of caspase-3 and caspase-9 protease in a dose-dependent manner without alteration of inhibitor of apoptosis proteins family and Akt expression. Western blot analysis and RT-PCR data revealed that the levels of tumor suppressor p53 and cyclin-dependent kinase inhibitor p21 were also remained unchanged. Conclusions : Taken together, these findings suggest that melittin-induced inhibition of human lung cancer cell growth is associated with the induction of apoptotic cell death via regulation of several major growth regulatory gene products, and melittin may have therapeutic potential in human lung cancer.