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Recent studies support the development of cancer therapeutics to target Globo H-ceramide, the most prevalent tumor-associated carbohydrate antigen in epithelial cancers. Herein, we evaluated the expression of Globo H and its prognostic significance in intrahepatic cholangiocarcinoma (ICC) and conducted preclinical studies to assess the antitumor activity of Globo H-specific antibody in thioacetamide (TAA)-induced ICC in rats. Globo H-ceramide in tumor specimens was detected by immunohistochemistry (IHC) and mass spectrometry. Antitumor efficacy of anti-Globo H mAbVK9 was evaluated in TAA-induced ICC in rat. Natural killer (NK) cells and their related genes were analyzed by IHC and quantitative real-time polymerase chain reaction. Data mining revealed that B3GALT5 and FUT2, the key enzymes for Globo H biosynthesis, were significantly up-regulated in human ICC. In addition, Globo H expression was detected in 41% (63 of 155) of ICC tumor specimens by IHC staining, and validated by mass spectrometric analysis of two IHC-positive tumors. Patients with Globo H positive tumors had significantly shorter relapse-free survival (RFS) and overall survival (P = 0.0003 and P = 0.002, respectively). Multivariable Cox regression analysis identified Globo H expression as an independent unfavorable predictor for RFS (hazard ratio: 1.66, 95% confidence interval: 1.08-2.36, P = 0.02) in ICC. Furthermore, gradual emergence of Globo H in liver tissues over 6 months in TAA-treated rats recapitulated the multistage progression of ICC in vivo. Importantly, administration of anti-Globo H mAbVK9 in rats bearing TAA-induced ICC significantly suppressed tumor growth with increased NK cells in the tumor microenvironment. Conclusion: Globo H is a theranostic marker in ICC.

Inappropriate c-MET signaling in cancer can enhance tumor cell proliferation, survival, motility, and invasion. Inhibition of c-MET signaling induces apoptosis in a variety of cancers. It has also been recognized as a novel anticancer therapy approach. Furthermore, reports have also indicated that constitutive expression of P-glycoprotein (ABCB1) is involved in the HGF/c-MET-related pathway of multidrug resistance ABCB1-positive human hepatocellular carcinoma cell lines. We previously reported that elevated expression levels of PKCδ and AP-1 downstream genes, and HGF receptor (c-MET) and ABCB1, in the drug-resistant MES-SA/Dx5 cells. Moreover, leukemia cell lines overexpressing ABCB1 have also been shown to be more resistant to the tyrosine kinase inhibitor imatinib mesylate. These findings suggest that chemoresistant cancer cells may also develop a similar mechanism against chemotherapy agents. To circumvent clinical complications arising from drug resistance during cancer therapy, the present study was designed to investigate apoptosis induction in ABCB1-overexpressed cancer cells using c-MET-targeted RNA interference technology in vitro and in vivo. The results showed that cell viability decreased and apoptosis rate increased in c-MET shRNA-transfected HGF/c-MET pathway-positive MES-SA/Dx5 and MCF-7/ADR2 cell lines in a dose-dependent manner. In vivo reduction of tumor volume in mice harboring c-MET shRNA-knockdown MES-SA/Dx5 cells was clearly demonstrated. Our study demonstrated that downregulation of c-MET by shRNA-induced apoptosis in a multidrug resistance cell line.

The echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion gene is an important biomarker for target therapy. The aim of this study is to better understand the clinical and molecular features of the EML4-ALK fusion gene in lung cancer patients in Taiwan and therefore to generate an efficient algorithm for the detection of ALK translocation. In the first cohort, ALK translocation was identified in 1 adenocarcinoma from 100 lung cancer patients by using break apart fluorescent in situ hybridization (FISH). Next, we detected 6 ALK translocations in another 40 EGFR wild type adenocarcinomas but not in 40 cases with EGFR mutation. Histological analysis revealed that solid growth with signet-ring cells or cribriform glands with extracellular mucin were noted in all the 7 ALK translocated cases. One ALK positive cancer with mucinous cribriform pattern had no ALK expression. ALK expression was correlated with ALK translocation (p < 0.001), but not with ALK gene copy number gain (CNG) (P = 0.838). ALK translocation was also mutually exclusive with EGFR mutation in Taiwanese non-small cell lung cancer (P = 0.033). These results indicate that screening tests for EGFR mutation status and/or ALK expression could help efficiently select ALK translocated patients for target therapy.

Multidrug resistance in cancer cells arises from altered drug permeability of the cell. We previously reported activation of the Wnt pathway in ABCB1-overexpressed human uterus sarcoma drug-resistant MES-SA/Dx5 cells through active β-catenin and associated transactivation activities, and upregulation of Wnt-targeting genes. In this study, Wnt5A was found to be significantly upregulated in MES-SA/Dx5 and MCF7/ADR2 cells, suggesting an important role for the Wnt5A signaling pathway in cancer drug resistance. Higher cAMP response elements and Tcf/Lef transcription activities were shown in the drug-resistant cancer cells. However, expression of Wnt target genes and CRE activities was downregulated in Wnt5A shRNA stably-transfected MES-SA/Dx5 cells. Cell viability of the drug-resistant cancer cells was also reduced by doxorubicin treatment and Wnt5A shRNA transfection, or by Wnt5A depletion. The in vitro data were supported by immunohistochemical analysis of 24 paired breast cancer biopsies obtained pre- and post-chemotherapeutic treatment. Wnt5A, VEGF and/or ABCB1 were significantly overexpressed after treatment, consistent with clinical chemoresistance. Taken together, the Wnt5A signaling pathway was shown to contribute to regulating the drug-resistance protein ABCB1 and β-catenin-related genes in antagonizing the toxic effects of doxorubicin in the MDR cell lines and in clinical breast cancer samples.

Introduction Idiopathic pulmonary fibrosis is a progressive diffuse parenchymal lung disorder of unknown etiology. Mesenchymal stem cell (MSC)-based therapy is a novel approach with great therapeutic potential for the treatment of lung diseases. Despite demonstration of MSC grafting, the populations of engrafted MSCs have been shown to decrease dramatically 24 hours post-transplantation due to exposure to harsh microenvironments. Hypoxia is known to induce expression of cytoprotective genes and also secretion of anti-inflammatory, anti-apoptotic and anti-fibrotic factors. Hypoxic preconditioning is thought to enhance the therapeutic potency and duration of survival of engrafted MSCs. In this work, we aimed to prolong the duration of survival of engrafted MSCs and to enhance the effectiveness of idiopathic pulmonary fibrosis transplantation therapy by the use of hypoxia-preconditioned MSCs. Methods Hypoxic preconditioning was achieved in MSCs under an optimal hypoxic environment. The expression levels of cytoprotective factors and their biological effects on damaged alveolar epithelial cells or transforming growth factor-beta 1-treated fibroblast cells were studied in co-culture experiments in vitro. Furthermore, hypoxia-preconditioned MSCs (HP-MSCs) were intratracheally instilled into bleomycin-induced pulmonary fibrosis mice at day 3, and lung functions, cellular, molecular and pathological changes were assessed at 7 and 21 days after bleomycin administration. Results The expression of genes for pro-survival, anti-apoptotic, anti-oxidant and growth factors was upregulated in MSCs under hypoxic conditions. In transforming growth factor-beta 1-treated MRC-5 fibroblast cells, hypoxia-preconditioned MSCs attenuated extracellular matrix production through paracrine effects. The pulmonary respiratory functions significantly improved for up to 18 days of hypoxia-preconditioned MSC treatment. Expression of inflammatory factors and fibrotic factor were all downregulated in the lung tissues of the hypoxia-preconditioned MSC-treated mice. Histopathologic examination observed a significant amelioration of the lung fibrosis. Several LacZ-labeled MSCs were observed within the lungs in the hypoxia-preconditioned MSC treatment groups at day 21, but no signals were detected in the normoxic MSC group. Our data further demonstrated that upregulation of hepatocyte growth factor possibly played an important role in mediating the therapeutic effects of transplanted hypoxia-preconditioned MSCs. Conclusion Transplantation of hypoxia-preconditioned MSCs exerted better therapeutic effects in bleomycin-induced pulmonary fibrotic mice and enhanced the survival rate of engrafted MSCs, partially due to the upregulation of hepatocyte growth factor.

Several studies of stem cell-based gene therapy have indicated that long-lasting regeneration following vessel ischemia may be stimulated through VEGFA gene therapy and/or MSC transplantation for reduction of ischemic injury in limb ischemia and heart failure. The therapeutic potential of MSC transplantation can be further improved by genetically modifying MSCs with genes which enhance angiogenesis following ischemic injury. In the present study, we aimed to develop an approach in MSC-based therapy for repair and mitigation of ischemic injury and regeneration of damaged tissues in ischemic disease. HSP70 promoter-driven VEGFA expression was induced by resveratrol (RSV) in MSCs, and in combination with known RSV biological functions, the protective effects of our approach were investigated by using ex vivo aortic ring coculture system and a 3D scaffolds in vivo model. Results of this investigation demonstrated that HSP promoter-driven VEGFA expression in MSC increased approximately 2-fold over the background VEGFA levels upon HSP70 promoter induction by RSV. Exposure of HUVEC cells to medium containing MSC in which VEGFA had been induced by cis-RSV enhanced tube formation in the treated HUVEC cells. RSV-treated MSC cells differentiated into endothelial-like phenotypes, exhibiting markedly elevated expression of endothelial cell markers. These MSCs also induced aortic ring sprouting, characteristic of neovascular formation from pre-existing vessels, and additionally promoted neovascularization at the MSC transplantation site in a mouse model. These observations support a hypothesis that VEGFA expression induced by cis-RSV acting on the HSP70 promoter in transplanted MSC augments the angiogenic effects of stem cell gene therapy. The use of an inducible system also vastly reduces possible clinical risks associated with constitutive VEGFA expression.

Multiple drug resistance (MDR) is a major obstacle to attenuating the effectiveness of chemotherapy to many human malignancies. Proteasome inhibition induces apoptosis in a variety of cancer cells and is recognized as a novel anticancer therapy approach. Despite its success, some multiple myeloma patients are resistant or become refractory to ongoing treatment by bortezomib suggesting that chemoresistant cancer cells may have developed a novel mechanism directed against the proteasome inhibitor. The present study aimed to investigate potential mechanism(s) of attenuation in a MDR cell line, MES-SA/Dx5. We found that compared to the parental human uterus sarcoma cell line MES-SA cells, MES-SA/Dx5 cells highly expressed the ABCB1 was more resistant to MG132 and bortezomib, escaping the proteasome inhibitor-induced apoptosis pathway. The resistance was reversed by co-treatment of MG132 and the ABCB1 inhibitor verapamil. The data indicated that ABCB1 might play a role in the efflux of MG132 from the MES-SA/Dx5 cells to reduce MG132-induced apoptosis. Furthermore, the canonical Wnt pathway was found activated only in the MES-SA/Dx5 cells through active β-catenin and related transactivation activities. Western blot analysis demonstrated that Wnt-targeting genes, including c-Myc and cyclin D1, were upregulated and were relevant in inhibiting the expression of p21 in MES-SA/Dx5 cells. On the other hand, MES-SA cells expressed high levels of p21 and downregulated cyclin D1 and caused cell cycle arrest. Together, our study demonstrated the existence and participation of ABCB1 and the Wnt pathway in an MDR cell line that attenuated proteasome inhibitor-induced apoptosis.

Multidrug-resistant (MDR) cancer is a major clinical problem in chemotherapy of cancer patients. We have noted inappropriate PKCδ hypomethylation and overexpression of genes in the PKCδ/AP-1 pathway in the human uterus sarcoma drug-resistant cell line, MES-SA/Dx5 cells, which also overexpress p-glycoprotein (ABCB1). Recent studies have indicated that FZD1 is overexpressed in both multidrug-resistant cancer cell lines and in clinical tumor samples. These data have led us to hypothesize that the FZD1-mediated PKCδ signal-transduction pathway may play an important role in drug resistance in MES-SA/Dx5 cells. In this work, the PKCδ inhibitor Rottlerin was found to reduce ABCB1 expression and to inhibit the MDR drug pumping ability in the MES-SA/Dx5 cells when compared with the doxorubicin-sensitive parental cell line, MES-SA. PKCδ was up-regulated with concurrent up-regulation of the mRNA levels of the AP-1-related factors, c-JUN and c-FOS. Activation of AP-1 also correlated with up-regulation of the AP-1 downstream genes HGF and EGR1. Furthermore, AP-1 activities were reduced and the AP-1 downstream genes were down-regulated in Rottlerin-treated or PKCδ shRNA-transfected cells. MES-SA/Dx5 cells were resensitized to doxorubicin-induced toxicity by co-treatment with doxorubicin and Rottlerin or PKCδ shRNA. In addition, cell viability and drug pump-out ability were significantly reduced in the FZD1 inhibitor curcumin-treated and FZD1 shRNA-knockdown MES-SA/Dx5 cells, indicating involvement of PKCδ in FZD1-modulated ABCB1 expression pathway. Taken together, our data demonstrate that FZD1 regulates PKCδ, and the PKCδ/AP-1 signalling transduction pathway plays an important role in drug resistance in MES-SA/Dx5 cells.

c-MET signaling is implicated in a wide variety of human malignancies. Hepatocyte growth factor (HGF) binding to the proto-oncogenic c-MET receptor lead to activate multiple tyrosine kinase signaling pathway. Inappropriate c-MET signaling in cancer can enhance tumor cell proliferation, survival, motility, and invasion. Recently, several reports have indicated that inhibition of c-MET signaling induced apoptosis in a variety of cancer cells and recognized as a novel anticancer therapy approach. Previous study from our laboratory also showed that the higher mRNA expression level of HGF, and its downstream genes including HGF receptor (c-Met) and urokinase (uPA) were detected in drug resistant Dx5-C5 cell compared with parental human uterus sarcoma MES-SA cell line. Furthermore, report indicated that the constitutive expression of P-glycoprotein (P-gp) is involved in the HGF/MET related pathway of MDR-positive human hepatocellular carcinoma cell line. Moreover, MDR1 gene overexpressed leukemia cell line also shown more resistance to tyrosine kinase inhibitor imatinib mesylate. These finding suggested that chemoresistant cancer cells may also develop a similar mechanism to against c-MET inhibitor. Our results shown: when treated both cell cancer lines with c-MET inhibitor PHA665752, we found that compared to parental MES-SA cells, the Dx5-C5 cells with highly expressed P-gp was more resistant to PHA665752, the resistance was also reversed by co-treatment of MDR inhibitor verapamil and PHA665752. In addition, when transfection of c-MET shRNA into Dx5-C5 and MES-SA cell line for 48 hrs, we found that the viability was decreased in the c-MET shRNA transfected Dx5-C5 cell line in a dose dependent manner but not in the MES-SA cell line. In conclusion, our study demonstrated that existence of P-glycoprotein in MDR cell line would attenuate c-MET inhibitor induced cell death and may help us to develop a new strategy for treatment of multiple drug resistance cancer cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1908. doi:1538-7445.AM2012-1908

Multiple drug resistance (MDR) is a major issue to attenuate the effectiveness of chemotherapy to many human malignancies. Despite extensively investigation, MDR inhibitors have been discovered serve side effect. Recently, scientists have reported that proteasome inhibitor, Bertezomib (PS-341), induced apoptosis in a variety of cancer cells and recognized as a novel anticancer therapy approach. Previous study revealed that bertezomib inhibits DNA methyltransferase and led to DNA hypomethylation in myeloid leukemia. Despite its success, some patients are resistant to ongoing proteasome inhibitor treatment. These reports suggested that chemoresistant cell line may develop a novel mechanism to against proteasome inhibitor. To verify the hypothesis, we used human CpG island microarray to indentify epigenetic change and genes expression profile in parental human uterus sarcoma cell line (MES-SA) and MES-SA variant drug resistant cell line (Dx5-C5) Our data has shown that the global genes were hypomethylated in both PS-341 treated MES-SA and Dx5-C5 cell line. Furthermore, the Wnt signalling pathway and cell cycle related gene have significant altered in DNA methylation pattern of Dx5-C5. In summary, our study demonstrated that the cell cycle related gene(s) and upstream gene(s) of Wnt pathway altered its DNA methylation pattern and mRNA expression level in MDR cell line. These data may help us to develop a new strategy for treatment of multiple drug resistance cancer cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4914.