Publication Date:
2012-09-14
Description:
Disruption of E-cadherin ( CDH1 gene) expression, subcellular localization or function arises during initiation and progression of almost 90% of all epithelial carcinomas. Nevertheless, the mechanisms through which this occurs are largely unknown. Previous studies showed the importance of CDH1 intron 2 sequences for proper gene and protein expression, supporting these as E-cadherin cis -modulators. Through RACE and RT-PCR, we searched for transcription events arising from CDH1 intron 2 and discovered several new transcripts. One, named CDH1a , with high expression in spleen and absent from normal stomach, was demonstrated to be translated into a novel isoform, differing from canonical E-cadherin in its N-terminal, as determined by mass spectrometry. Quantitative and functional assays showed that when overexpressed in an E-cadherin negative context, CDH1a replaced canonical protein interactions and functions. However, when co-expressed with canonical E-cadherin, CDH1a increased cell invasion and angiogenesis. Further, interferon-induced gene IFITM1 and IFI27 levels were increased upon CDH1a overexpression. Effects on invasion and IFITM1 and IFI27 expression were reverted upon CDH1a -specific knockdown. Importantly, CDH1a was de novo expressed in gastric cancer cell lines. This study presents a new mechanism by which E-cadherin functions are impaired by cis -regulatory mechanisms possibly with the involvement of inflammatory machinery. If confirmed in other cancer models, our data enclose potential for designing targeted therapies to rescue E-cadherin function.
Print ISSN:
0964-6906
Electronic ISSN:
1460-2083
Topics:
Biology
,
Medicine
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