Seder Christopher W, Hartojo Wibisono, Lin Lin, Silvers Amy L, Wang Zhuwen, Thomas Dafydd G, Giordano Thomas J, Chen Guoan, Chang Andrew C, Orringer Mark B, Beer David G
Department of Surgery, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
J Thorac Oncol. 2009 Apr;4(4):455-62. doi: 10.1097/JTO.0b013e31819c791a.
The expression, mechanisms of regulation, and functional impact of activin (INHBA) in esophageal adenocarcinoma (EAC) have not been fully defined.
INHBA expression was examined in 46 esophageal samples (nine Barrett's metaplasia (BM); seven BM/low-grade dysplasia; eight low-grade dysplasia; seven high-grade dysplasia; 15 EAC) using oligonucleotide microarrays and real-time reverse transcription-polymerase chain reaction (RT-PCR) and in 90 tissue samples (79 EAC; 8 dysplastic; 3 BM) using immunohistochemistry (IHC). The proliferation of EAC cell lines FLO and OE-33 was examined after treatment with exogenous activin. The proliferation of OE-33 was also examined after treatment with the activin inhibitor follistatin and INHBA-targeting siRNA. OE-33 and FLO cells were treated with 5-aza-2'deoxycytidine (5-AZA) and trichostatin A to investigate the role of epigenetic regulation in INHBA expression.
Primary EACs expressed 5.7-times more INHBA mRNA than BM samples on oligonucleotide microarray. Transcript overexpression in EAC relative to BM was confirmed on real-time RT-PCR. IHC suggested higher INHBA protein expression in EAC (69.6%) than in the dysplastic (37.5%) and BM samples (33.3%). FLO and OE-33 treated with activin demonstrated increased proliferation, and OE-33 cells treated with follistatin and INHBA-targeting siRNA demonstrated reduced proliferation, relative to untreated controls. Treatment of FLO cells with trichostatin A and 5-AZA up-regulated INHBA mRNA and protein production by real time RT-PCR and IHC.
INHBA is overexpressed in EAC relative to dysplastic and BM tissue. INHBA overexpression may promote cell proliferation and may be affected by promoter demethylation and histone acetylation in EAC cell lines.
激活素（抑制素βA，INHBA）在食管腺癌（EAC）中的表达、调控机制及功能影响尚未完全明确。
使用寡核苷酸微阵列和实时逆转录聚合酶链反应（RT-PCR）检测了46份食管样本（9份巴雷特化生（BM）；7份BM/低级别发育异常；8份低级别发育异常；7份高级别发育异常；15份EAC）中的INHBA表达，并使用免疫组织化学（IHC）检测了90份组织样本（79份EAC；8份发育异常；3份BM）中的INHBA表达。用外源性激活素处理食管腺癌细胞系FLO和OE-33后，检测细胞增殖情况。用激活素抑制剂卵泡抑素和靶向INHBA的小干扰RNA（siRNA）处理OE-33后，也检测细胞增殖情况。用5-氮杂-2'-脱氧胞苷（5-AZA）和曲古抑菌素A处理OE-33和FLO细胞，以研究表观遗传调控在INHBA表达中的作用。
在寡核苷酸微阵列上，原发性EAC中INHBA mRNA的表达量比BM样本高5.7倍。实时RT-PCR证实了EAC相对于BM的转录本过表达。IHC显示EAC中INHBA蛋白表达（69.6%）高于发育异常样本（37.5%）和BM样本（33.3%）。与未处理的对照相比，用激活素处理的FLO和OE-33细胞增殖增加，用卵泡抑素和靶向INHBA的siRNA处理的OE-33细胞增殖减少。用曲古抑菌素A和5-AZA处理FLO细胞后，通过实时RT-PCR和IHC检测发现INHBA mRNA和蛋白产量上调。
相对于发育异常和BM组织，INHBA在EAC中过表达。INHBA过表达可能促进细胞增殖，且可能受EAC细胞系中启动子去甲基化和组蛋白乙酰化的影响。
