MiR-205 and MiR-373 Are Associated with Aggressive Human Mucinous Colorectal Cancer.
Mucinous adenocarcinoma (MAC) represents a distinct histopathological entity of colorectal cancer (CRC), which is associated with disease progression and poor prognosis. Here, we found that expression levels of miR-205 and miR-373 were specifically upregulated only in patients with mucinous colon cancers, but not in CRC that lack mucinous components. To investigate the effects of miR-205 and miR-373 on intestinal epithelial cell (IEC) biology by gain- and loss-of-function experiments in a proof-of-concept approach, we chose previously established in-vitro human Caco-2-based models of differentiated, non-invasive (expressing TLR4 wild-type; termed Caco-2[WT]) versus undifferentiated, invasive (expressing TLR4 mutant D299G; termed Caco-2[D299G]) IEC. Enterocyte-like Caco-2[WT] showed low levels of miR-205 and miR-373 expression, while both miRNAs were significantly upregulated in colorectal carcinoma-like Caco-2[D299G], thus resembling the miRNA expression pattern of paired normal versus tumor samples from MAC patients. Using stable transfection, we generated miR-205- or miR-373-expressing and miR-205- or miR-373-inhibiting subclones of these IEC lines. We found that introduction of miR-205 into Caco-2[WT] led to expansion of mucus-secreting goblet cell-like cells, which was associated with induction of KLF4, MUC2 and TGFβ1 expression. Activation of miR-205 in Caco-2[WT] induced chemoresistance, while inhibition of miR-205 in Caco-2[D299G] promoted chemosensitivity. Caco-2[WT] overexpressing miR-373 showed mitotic abnormalities and underwent morphologic changes (loss of epithelial polarity, cytoskeletal reorganization, and junctional disruption) associated with epithelial-mesenchymal transition and progression to inflammation-associated colonic carcinoma, which correlated with induction of phosphorylated STAT3 and N-CADHERIN expression. Functionally, introduction of miR-373 into Caco-2[WT] mediated loss of cell-cell adhesion and increased proliferation and invasion. Reversely, inhibition of miR-373 allowed mesenchymal IEC to regain epithelial properties, which correlated with absence of neoplastic progression. Using xenografts in mice demonstrated miR-373-mediated acceleration of malignant intestinal tumor growth. In conclusion, our results provide first evidence that miR-205 and miR-373 may differentially contribute to the aggressive phenotype of MAC in CRC.
Department of Gastroenterology and Hepatology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Annette
A
Eyking
Institute of Pathology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Henning
H
Reis
Department of Gastroenterology and Hepatology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Magdalena
M
Frank
Department of Gastroenterology and Hepatology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Guido
G
Gerken
Institute of Pathology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Kurt W
KW
Schmid
Department of Gastroenterology and Hepatology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Elke
E
Cario
D002288:Adenocarcinoma, Mucinous / Q000235:genetics* / Q000473:pathology*; D000818:Animals; D018938:Caco-2 Cells; D002478:Cells, Cultured; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D045325:HCT116 Cells; D019073:HT29 Cells; D006801:Humans; D000090062:Kruppel-Like Factor 4; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000502:physiology*; D009361:Neoplasm Invasiveness
D000090062:Kruppel-Like Factor 4; D035683:MicroRNAs; C000715467:KLF4 protein, human; C000715468:Klf4 protein, mouse; C534425:MIR205, human; C527114:MIRN373 microRNA, human