Enhanced Therapeutic Potential of the Secretome Released from Adipose-Derived Stem Cells by PGC-1α-Driven Upregulation of Mitochondrial Proliferation.

Peroxisome proliferator activated receptor λ coactivator 1α (PGC-1α) is a potent regulator of mitochondrial biogenesis and energy metabolism. In this study, we investigated the therapeutic potential of the secretome released from the adipose-derived stem cells (ASCs) transfected with PGC-1α (PGC-secretome). We first generated PGC-1α-overexpressing ASCs by transfecting ASCs with the plasmids harboring the gene encoding PGC-1α. Secretory materials released from PGC-1α-overexpressing ASCs were collected and their therapeutic potential was determined using in vitro (thioacetamide (TAA)-treated AML12 cells) and in vivo (70% partial hepatectomized mice) models of liver injury. In the TAA-treated AML12 cells, the PGC-secretome significantly increased cell viability, promoted expression of proliferation-related markers, such as PCNA and p-STAT, and significantly reduced the levels of reactive oxygen species (ROS). In the mice, PGC-secretome injections significantly increased liver tissue expression of proliferation-related markers more than normal secretome injections did (p < 0.05). We demonstrated that the PGC-secretome does not only have higher antioxidant and anti-inflammatory properties, but also has the potential of significantly enhancing liver regeneration in both in vivo and in vitro models of liver injury. Thus, reinforcing the mitochondrial antioxidant potential by transfecting ASCs with PGC-1α could be one of the effective strategies to enhance the therapeutic potential of ASCs.

Hedgehog signaling between cancer cells and hepatic stellate cells in promoting cholangiocarcinoma.

BACKGROUND: Aberrant Hedgehog (HH) signaling activation is important in cancer growth and mediates the interaction between cancer cells and the surrounding stromal cells. This study investigated the role of HH signaling on the growth of cholangiocarcinoma (CC), focusing on the interaction of CC cells with stromal cells. METHODS: To evaluate the interaction between human CC cells (SNU-1196, SNU-246, SNU-308, SNU-1079, and HuCCT-1) and stromal cells (hepatic stellate cell line, Lx-2), co-culture proliferation, migration, and invasion assays were performed. In vivo nude mice experiments were conducted using two groups-HuCCT-1 single implant xenograft (SX) and co-implant xenograft (CX) with HuCCT-1 and Lx-2. RESULTS: When HuCCT-1 cells were co-cultured with Lx-2 cells, the expression of HH signaling-related proteins increased in both HuCCT-1 and Lx-2 cells. Co-culture with Lx-2 cells stimulated the proliferation, migration, and invasion of CC cells, and these effects were mediated by HH signaling. Co-culture of HuCCT-1 and Lx-2 cells increased the secretion of several cytokines. In an ectopic xenograft model, Lx-2 co-implantation increased CC tumor growth and stimulated angiogenesis. Cyclopamine attenuated tumor growth in the CX group, but not in the HuCCT-1 mono-implant (SX) group. Cyclopamine treatment decreased CC cell proliferation, suppressed microvessel density, and increased tumor necrosis in the CX group, but not in the SX group. CONCLUSION: Hepatic stellate cells stimulate the proliferation, migration, and invasion of CC cells, promote angiogenesis through HH signaling activation, and render CC more susceptible to necrosis by HH inhibitor.

Starfish polysaccharides downregulate metastatic activity through the MAPK signaling pathway in MCF-7 human breast cancer cells.

We investigated the effects of starfish (Asterina pectinifera) polysaccharides on metastatic activity in MCF-7 estrogen receptor (ER)-positive human breast cancer cells. In wound healing assay, 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cell migration was dose-dependently decreased by the starfish polysaccharides (PS). Transcription of aromatase, which catalyzes estrogen synthesis from androgen, was reduced by PS. Also, transcription of TPA-induced cyclooxygenase-2 (COX-2), which enhances breast cancer progression and metastasis via the increase of prostaglandin E2 biosynthesis, was downregulated by the PS in a dose-dependent manner. PS decreased the expression and activity of matrix metalloproteinase (MMP)-9, an important factor in the degradation of basement membrane and extracellular matrix in the metastasis process. In contrast, mRNA expression of tissue inhibitor of matrix metalloproteinase (TIMP)-1, a MMP inhibitor, was increased by 10-120 µg/ml of PS but not that of TIMP-2. We also found that PS reversed the phosphorylations of p38, ERK and JNK but not IκBα and NF-κB. These results demonstrate that PS successfully inhibits PKC-mediated cell migration and metastatic activities in MCF-7 ER-positive human breast cancer cells via downregulation of MMP-9 activity mediated by TIMP-1 upregulation and inhibition of aromatase and COX-2 expression. Also, COX-2 and MMP-9 expressions are attenuated through the inhibition of AP-1 transcription activity via the downregulation of c-Jun expression regulated by p38, ERK and JNK signaling. In conclusion, the present investigation shows that PS may prevent COX-2- and MMP-9-mediated metastatic activities in MCF-7 ER-positive breast cancer cells through the downregulation of MAPK signaling pathways.

Potentiation of the Anticancer Effects by Combining Docetaxel with Ku-0063794 against Triple-Negative Breast Cancer Cells.

PURPOSE: mTORC1 and mTORC2 inhibition by Ku-0063794 could confer profound anticancer effects against cancer cells because it eliminates feedback activation of Akt. Herein, we aimed to determine anticancer effects of docetaxel and Ku-0063794, individually or in combination, against breast cancer cells, especially triple-negative breast cancer (TNBC) cells. MATERIALS AND METHODS: MCF-7 breast cancer and MDA-MB-231 TNBC cell lines for in vitro studies and mouse xenograft model for in vivo studies were used to investigate the effect of docetaxel, Ku-0063794, or their combination. RESULTS: In the in vitro experiments, combination therapy synergistically reduced cell viability and induced higher apoptotic cell death in breast cancer cells than the individual monotherapies (p < 0.05). Western blot analysis and flow cytometric analysis showed that the combination therapy induced higher apoptotic cell death than the individual monotherapies (p < 0.05). In the in vivo experiment, docetaxel and Ku-0063794 combination therapy reduced the growth of MDA-MB-231 cells xenografted in the nude mice better than in the individual monotherapies (p < 0.05). Immunohistochemistry showed that the combination therapy induced the highest expression of cleaved caspase-3 and the lowest expression of Bcl-xL in the MDA-MB-231 cells xenografted in the nude mice (p < 0.05). Western blot analysis and immunofluorescence, incorporating both in vitro and in vivo experiments, consistently validated that unlike individual monotherapies, docetaxel and Ku-0063794 combination therapy significantly inhibited epithelial-mesenchymal transition (EMT) and autophagy (p < 0.05). CONCLUSION: These data suggest that docetaxel and Ku-0063794 combination therapy has higher anticancer activities over individual monotherapies against MDA-MB-231 TNBC cells through a greater inhibition of autophagy and EMT.