Effect of verteporfin-PDT on the Notch signaling pathway in cholangiocarcinoma (CCA) cell lines

Accumulating preclinical and clinical evidence supports a pro-oncogenic function for Notch signaling in several solid tumors. Therefore, Notch inhibitory agents, such as gamma-secretase inhibitors (GSI), are being investigated as cancer therapeutic agents and a potential adjuvant to conventional chemo/radiotherapy. To date, no in vitro data are available on the cellular response and effect of either photodynamic therapy (PDT) or GSI on human cholangiocarcinoma (CCA). Consequently, we aimed to study the: (i) constitutive expression of Notch signaling pathway in CCA cell lines; (ii) response to Verteporfin-PDT and to GSI, as single agents on CCA cell lines; (iii) effect of Verteporfin-PDT on Notch signaling pathway expression. Expression of Notch signaling components was studied in two cholangiocarcinoma cell lines, HuCCT1 and TFK-1 (intra- and extrahepatic, respectively). No difference in basal expression of Notch1, 2 and Jagged1 was observed in either cell line. In contrast, Notch3 was found to be weakly and highly expressed in HuCCT1 and TFK-1 cells, respectively - supporting our recent microarray data which showed Notch3 overexpression in biliary brushings from patients with extrahepatic CCA. HuCCT1 and TFK-1 differentially responded to Verteporfin-PDT treatment; preliminary data showed no clear effect of GSI on proliferation/apoptosis in either cell line following short exposure (6 and 24h). Following Verteporfin-PDT, Notch1, 2 and Jagged-1 expression was down-regulated in both cell lines, while Notch3 expression was unaffected in HuCCT1 cells and down-regulated in TFK-1 cells. The Notch signaling pathway could represent a potential target for combination therapy in CCA treatment.

[1]  Christel Brou,et al.  Signalling downstream of activated mammalian Notch , 1995, Nature.

[2]  Thomas Gridley,et al.  A mouse model of Alagille syndrome: Notch2 as a genetic modifier of Jag1 haploinsufficiency. , 2002, Development.

[3]  B. Trask,et al.  Cloning, characterization, and the complete 56.8-kilobase DNA sequence of the human NOTCH4 gene. , 1998, Genomics.

[4]  F. Kuo,et al.  Isolation and functional analysis of a cDNA for human Jagged2, a gene encoding a ligand for the Notch1 receptor , 1997, Molecular and cellular biology.

[5]  T. Kudo,et al.  Presenilins mediate a dual intramembranous γ‐secretase cleavage of Notch‐1 , 2002 .

[6]  E. Lander,et al.  Mutations in the human Delta homologue, DLL3, cause axial skeletal defects in spondylocostal dysostosis , 2000, Nature Genetics.

[7]  William J. Ray,et al.  A presenilin-1-dependent γ-secretase-like protease mediates release of Notch intracellular domain , 1999, Nature.

[8]  P. van Eyken,et al.  Hepatic jagged1 expression studies , 1999, Hepatology.

[9]  R. Hruban,et al.  Notch mediates TGF alpha-induced changes in epithelial differentiation during pancreatic tumorigenesis. , 2003, Cancer cell.

[10]  D. Ward,et al.  Human ligands of the Notch receptor. , 1999, The American journal of pathology.

[11]  Kenji Matsuno,et al.  Notch signaling. , 1995, Science.

[12]  J. Weissenbach,et al.  Notch3 mutations in CADASIL, a hereditary adult-onset condition causing stroke and dementia , 1996, Nature.

[13]  M. Bosenberg,et al.  lag-1, a gene required for lin-12 and glp-1 signaling in Caenorhabditis elegans, is homologous to human CBF1 and Drosophila Su(H). , 1996, Development.

[14]  W. Richards,et al.  Dll4, a novel Notch ligand expressed in arterial endothelium. , 2000, Genes & development.

[15]  F. Hoffmann,et al.  Homologs of vertebrate growth factors in Drosophila melanogaster and other invertebrates. , 1990, Current topics in developmental biology.

[16]  Paul S. Meltzer,et al.  Mutations in the human Jagged1 gene are responsible for Alagille syndrome , 1997, Nature Genetics.

[17]  B. Osborne,et al.  Notch signaling as a therapeutic target in cancer: a new approach to the development of cell fate modifying agents , 2003, Oncogene.

[18]  S. Artavanis-Tsakonas,et al.  Notch Signaling : Cell Fate Control and Signal Integration in Development , 1999 .

[19]  J. Sklar,et al.  TAN-1, the human homolog of the Drosophila Notch gene, is broken by chromosomal translocations in T lymphoblastic neoplasms , 1991, Cell.

[20]  L. L. Reed,et al.  Gamma secretase inhibitor blocks Notch activation and induces apoptosis in Kaposi's sarcoma tumor cells , 2005, Oncogene.

[21]  S. Leach,et al.  Notch in malignancy. , 2003, Cancer treatment and research.

[22]  Stefano Stifani,et al.  Human homologs of a Drosophila Enhancer of Split gene product define a novel family of nuclear proteins , 1992, Nature Genetics.

[23]  G. Weinmaster,et al.  The Ins and Outs of Notch Signaling , 1997, Molecular and Cellular Neuroscience.

[24]  Hans Clevers,et al.  Notch/γ-secretase inhibition turns proliferative cells in intestinal crypts and adenomas into goblet cells , 2005, Nature.

[25]  F. Kelleher,et al.  Common critical pathways in embryogenesis and cancer , 2006, Acta oncologica.

[26]  M. Masu,et al.  Conversion of biliary system to pancreatic tissue in Hes1-deficient mice , 2004, Nature Genetics.

[27]  Raphael Kopan,et al.  The Notch pathway: democracy and aristocracy in the selection of cell fate , 1996, Current Opinion in Neurobiology.