28-30 Cyclopamine

(2.5 mg/kg body weight; 0.5 mL), complexed with 2-hydroxypropyl-β-cyclodextrin (Tocris, Ellisville, MO), as previously described, 33, 34 or vehicle was given intraperitoneally every day for 1 week (first injection: postoperative day 7; seventh injection: postoperative day 13). Twenty-four hours after receiving Napabucasin price the last injection, rats were euthanized and livers were removed for further analysis, including histopathology and mRNA extraction. To assess the numbers of metastases-free and metastases-bearing rats, abdominal cavities, retroperitoneal spaces, and thoracic cavities were thoroughly examined as previously described.29 Materials, generation of shSMO KMCH-1 cells, quantitation of PDGF-BB and cAMP, coculture experiments, quantitation Cetuximab research buy of apoptosis, immunoblotting analysis, immunohistochemistry for α-SMA, PDGFR-β, PDGF-BB, and cytokeratin 7 (CK7), as well as reverse-transcriptase polymerase chain reaction (RT-PCR), the genome-wide mRNA expression assay, and statistical analysis are described in the Supporting Information.

Initially, we assessed basal PDGF-BB secretion by two human CCA cell lines, KMCH-1 and KMBC, primary HSC cells, and the human MFB cell line, LX-2, by enzyme-linked immunosorbent assay (ELISA) (monoculture conditions; Fig. 1A). The MFB cells secreted significantly higher levels of PDGF-BB than the CCA cell lines. Because many cancer cells do not express PDGF receptors, 35 we next examined KMCH-1

cells for the presence of PDGFR-β and its activating phosphorylation by PDGF-BB (Fig. 1B). Immunoblotting analysis confirmed the protein expression of PDGFR-β in KMCH-1 cells (Fig. 1B, lower), whereas PDGFR-α was not detectable (data not shown). PDGFR-β also displayed receptor phosphorylation Tideglusib (Tyr857) upon PDGF-BB treatment (Fig. 1B, upper). In addition, we confirmed the mRNA expression of PDGFR-β in KMCH-1 cells and four other human CCA cell lines (KMBC, HuCCT-1, TFK-1, and MzChA-1), as well as in the ErbB-2/neu-transformed malignant rat cholangiocyte cell line, BDEneu (employed in the in vivo CCA model; Supporting Fig. 1). To characterize the expression of α-SMA, PDGFR-β, and PDGF-BB in vivo, we performed immunohistochemistry for these proteins in human CCA specimens (Fig. 1C). Numerous α-SMA-positive MFBs were present in the stromal tumor microenvironment in all human CCA samples examined (Fig. 1C, left). Moreover, PDGFR-β immunoreactivity was confirmed in CCA cell glands in approximately half of the samples (Fig. 1C, middle), whereas PDGF-BB was expressed in MFBs in two-thirds of the samples (Fig. 1C, right). Thus, PDGF-BB was shown to be secreted by MFBs and its receptor was expressed by CCA cells.