Integrated proteomics and genomics analysis reveals a novel mesenchymal to epithelial reverting transition in leiomyosarcoma through regulation of slug.
Leiomyosarcoma is one of the most common mesenchymal tumors. Proteomics profiling analysis by reverse-phase protein lysate array surprisingly revealed that expression of the epithelial marker E-cadherin (encoded by CDH1) was significantly elevated in a subset of leiomyosarcomas. In contrast, E-cadherin was rarely expressed in the gastrointestinal stromal tumors, another major mesenchymal tumor type. We further sought to 1) validate this finding, 2) determine whether there is a mesenchymal to epithelial reverting transition (MErT) in leiomyosarcoma, and if so 3) elucidate the regulatory mechanism responsible for this MErT. Our data showed that the epithelial cell markers E-cadherin, epithelial membrane antigen, cytokeratin AE1/AE3, and pan-cytokeratin were often detected immunohistochemically in leiomyosarcoma tumor cells on tissue microarray. Interestingly, the E-cadherin protein expression was correlated with better survival in leiomyosarcoma patients. Whole genome microarray was used for transcriptomics analysis, and the epithelial gene expression signature was also associated with better survival. Bioinformatics analysis of transcriptome data showed an inverse correlation between E-cadherin and E-cadherin repressor Slug (SNAI2) expression in leiomyosarcoma, and this inverse correlation was validated on tissue microarray by immunohistochemical staining of E-cadherin and Slug. Knockdown of Slug expression in SK-LMS-1 leiomyosarcoma cells by siRNA significantly increased E-cadherin; decreased the mesenchymal markers vimentin and N-cadherin (encoded by CDH2); and significantly decreased cell proliferation, invasion, and migration. An increase in Slug expression by pCMV6-XL5-Slug transfection decreased E-cadherin and increased vimentin and N-cadherin. Thus, MErT, which is mediated through regulation of Slug, is a clinically significant phenotype in leiomyosarcoma.
Yang
Jilong
J
Department of Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA. jilongyang2003@yahoo.com.cn
Eddy
James A
JA
Pan
Yuan
Y
Hategan
Andrea
A
Tabus
Ioan
I
Wang
Yingmei
Y
Cogdell
David
D
Price
Nathan D
ND
Pollock
Raphael E
RE
Lazar
Alexander J F
AJ
Hunt
Kelly K
KK
Trent
Jonathan C
JC
Zhang
Wei
W
D015415:Biomarkers; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002465:Cell Movement; D049109:Cell Proliferation; D058750:Epithelial-Mesenchymal Transition; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D023281:Genomics / Q000379:methods*; D006801:Humans; D007890:Leiomyosarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D046228:Microarray Analysis; D040901:Proteomics / Q000379:methods*; D000071250:Snail Family Transcription Factors; D015996:Survival Rate; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014746:Vimentin / Q000378:metabolism
D015415:Biomarkers; D015820:Cadherins; C000604407:SNAI1 protein, human; C000604408:SNAI2 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D014746:Vimentin