Epithelial-to-mesenchymal transition and resistance to ingenol 3-angelate, a novel protein kinase C modulator, in colon cancer cells.
Acquired resistance to protein kinase C (PKC) modulators may explain the failure of clinical trials in patients with cancer. Herein, we established a human colon cancer cell line resistant to PEP005, a drug that inhibits PKCalpha and activates PKCdelta. Colo205-R cells, selected by stepwise exposure to PEP005, were >300-fold more resistant to PEP005 than parental Colo205-S cells and were cross-resistant to phorbol 12-myristate 13-acetate, bryostatin, bistratene A, and staurosporine. No PKCalpha or PKCdelta mutation was detected in Colo205-S and Colo205-R cells. Changes in Colo205-R cells were reminiscent of the epithelial-to-mesenchymal transition (EMT) phenotype. Accordingly, Colo205-R cells were more invasive than Colo205-S in Matrigel assays and in mouse xenografts. We also found an increased mRNA expression of several EMT genes, such as those encoding for transforming growth factor-beta and vimentin, along with a decreased mRNA expression of genes involved in epithelial differentiation, such as CDH1 (E-cadherin), CLDN4 (claudin 4), S100A4, and MUC1, in Colo205-R compared with Colo205-S cells in vitro and in vivo. Interestingly, high expression of ET-1 was shown in Colo205-R cells and correlated with low sensitivity to PEP005 and staurosporine in a panel of 10 human cancer cell lines. Inhibition of the ET-1 receptor ETR-A with bosentan restored the antiproliferative effects of PEP005 in Colo205-R cells and decreased the invasive properties of this cell line. Exogenous exposure to ET-1 and silencing ET-1 expression using small interfering RNA modulated cell signaling in Colo205-S and Colo205-R. In summary, acquired resistance to PEP005 was associated with expression of EMT markers and activates the ET-1/ETR-A cell signaling.
Institut National de la Sante et de la Recherche Medicale U728, RayLab, and Department of Medical Oncology, Beaujon and Saint-Louis University Hospital (AP-HP-Paris 7 Diderot), Clichy, France.
Aïda
A
Ghoul
Maria
M
Serova
Lucile
L
Astorgues-Xerri
Ivan
I
Bieche
Guilhem
G
Bousquet
Mariana
M
Varna
Michel
M
Vidaud
Edelmira
E
Phillips
Sophie
S
Weill
Karim A
KA
Benhadji
François
F
Lokiec
Esteban
E
Cvitkovic
Sandrine
S
Faivre
Eric
E
Raymond
D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D004224:Diterpenes / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology*; D005091:Exons; D005260:Female; D006801:Humans; D020782:Matrix Metalloproteinases / Q000187:drug effects / Q000378:metabolism; D008648:Mesoderm / Q000187:drug effects / Q000473:pathology*; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism; D051571:Protein Kinase C-alpha / Q000187:drug effects / Q000235:genetics*; D051745:Protein Kinase C-delta / Q000187:drug effects / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014183:Transplantation, Heterologous
C486592:3-ingenyl angelate; D004224:Diterpenes; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; D020782:Matrix Metalloproteinases