Thymidylate synthase is functionally associated with ZEB1 and contributes to the epithelial-to-mesenchymal transition of cancer cells.
Thymidylate synthase (TS) is a fundamental enzyme of nucleotide metabolism and one of the oldest anti-cancer targets. Beginning from the analysis of gene array data from the NCI-60 panel of cancer cell lines, we identified a significant correlation at both gene and protein level between TS and the markers of epithelial-to-mesenchymal transition (EMT), a developmental process that allows cancer cells to acquire features of aggressiveness, like motility and chemoresistance. TS levels were found to be significantly augmented in mesenchymal-like compared to epithelial-like cancer cells, to be regulated by EMT induction, and to negatively correlate with micro-RNAs (miRNAs) usually expressed in epithelial-like cells and known to actively suppress EMT. Transfection of EMT-suppressing miRNAs reduced TS levels, and a specific role for miR-375 in targeting the TS 3'-untranslated region was identified. A particularly relevant association was found between TS and the powerful EMT driver ZEB1, the shRNA-mediated knockdown of which up-regulated miR-375 and reduced TS cellular levels. The TS-ZEB1 association was confirmed in clinical specimens from lung tumours and in a genetic mouse model of pancreatic cancer with ZEB1 deletion. Interestingly, TS itself appeared to have a regulatory role in EMT in cancer cells, as TS knockdown could directly reduce the EMT phenotype, the migratory ability of cells, the expression of stem-like markers, and chemoresistance. Taken together, these data indicate that the TS enzyme is functionally linked with EMT and cancer differentiation, with several potential translational implications. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Junior Research Group 1, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Aarif
A
Siddiqui
Junior Research Group 1, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Maria Eleni
ME
Vazakidou
Junior Research Group 1, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Annemarie
A
Schwab
Junior Research Group 1, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Francesca
F
Napoli
Junior Research Group 1, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Cristina
C
Fernandez-Molina
Pathology Unit, San Luigi Hospital, University of Turin, Turin, Italy.
Ida
I
Rapa
Experimental Medicine I, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Marc P
MP
Stemmler
Pathology Unit, San Luigi Hospital, University of Turin, Turin, Italy.
Marco
M
Volante
Experimental Medicine I, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Thomas
T
Brabletz
Junior Research Group 1, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Paolo
0000-0002-3632-8476
P
Ceppi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001483:Base Sequence; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D034741:RNA, Small Interfering / Q000235:genetics; D013940:Thymidylate Synthase / Q000235:genetics* / Q000378:metabolism; D000071799:Zinc Finger E-box-Binding Homeobox 1 / Q000235:genetics* / Q000378:metabolism
C540933:MIRN375 microRNA, human; D035683:MicroRNAs; D034741:RNA, Small Interfering; C486307:ZEB1 protein, human; D000071799:Zinc Finger E-box-Binding Homeobox 1; D013940:Thymidylate Synthase
ZEB1; epithelial-to-mesenchymal transition; micro-RNAs; solid tumours; thymidylate synthase