Apatinib, an inhibitor of vascular endothelial growth factor receptor-2, has been shown to promote anti-cancer action across a wide range of malignancies, including gastric, lung, and breast cancers. Our previous study showed that apatinib increases apoptosis in anaplastic thyroid carcinoma (ATC), but the direct functional mechanism of tumor lethality mediated by apatinib is still unknown. In this study, we demonstrated that apatinib induced both autophagy and apoptosis in human ATC cells through downregulation of p-AKT and p-mTOR signals via the AKT/mTOR pathway. Moreover, inhibition of apatinib-induced autophagy increased apatinib-induced apoptosis in ATC cells, and additional tumor suppression was critically produced by the combination of apatinib and the autophagy inhibitor chloroquine in vivo and in vitro. These findings showed that both autophagy and AKT/mTOR signals were engaged in ATC cell death evoked by apatinib. ATC patients might benefit from the new anti-cancer drug, and molecular targeted treatment in combination with autophagy inhibitors shows promise as a treatment improvement.
ObjectiveHepatic stellate cells (HSCs) transdifferentiation and subsequent inflammation are important pathological processes involved in the formation of cirrhotic portal hypertension. This study characterizes the pathogenetic mechanisms leading to cholestatic liver fibrosis and portal hypertension, and focuses on mammalian target of rapamycin (mTOR) pathway as a potential modulator in the early phase of cirrhotic portal hypertension.MethodsEarly cirrhotic portal hypertension was induced by bile duct ligation (BDL) for three weeks. One week after operation, sham-operated (SHAM) and BDL rats received rapamycin (2 mg/kg/day) by intraperitoneal injection for fourteen days. Vehicle-treated SHAM and BDL rats served as controls. Fibrosis, inflammation, and portal pressure were evaluated by histology, morphometry, and hemodynamics. Expressions of pro-fibrogenic and pro-inflammatory genes in liver were measured by RT-PCR; alpha smooth muscle actin (α-SMA) and antigen Ki67 were detected by immunohistochemistry; expressions of AKT/mTOR signaling molecules, extracellular-signal-regulated kinase 1/2 (ERK1/2), p-ERK1/2, and interleukin-1 beta (IL-1β) were assessed by western blot.ResultsThe AKT/mTOR signaling pathway was markedly activated in the early phase of cirrhotic portal hypertension induced by BDL in rats. mTOR blockade by rapamycin profoundly improved liver function by limiting inflammation, fibrosis and portal pressure. Rapamycin significantly inhibited the expressions of phosphorylated 70KD ribosomal protein S6 kinase (p-P70S6K) and phosphorylated ribosomal protein S6 (p-S6) but not p-AKT Ser473 relative to their total proteins in BDL-Ra rats. Those results suggested that mTOR Complex 1 (mTORC1) rather than mTORC2 was inhibited by rapamycin. Interestingly, we also found that the level of p-ERK1/2 to ERK1/2 was significantly increased in BDL rats, which was little affected by rapamycin.ConclusionsThe AKT/mTOR signaling pathway played an important role in the early phase of cirrhotic portal hypertension in rats, which could be a potential target for therapeutic intervention in the early phase of such pathophysiological progress.
Mesenchymal stem cell (MSC) therapy can prevent hepatic parenchymal cell loss and promote tissue repair. However, poor MSC engraftment is one of the primary barriers to the effectiveness of cell therapy because culture-expanded MSCs progressively downregulate C-X-C chemokine receptor type 4 (CXCR4) expression and lose their ability to migrate toward a concentration gradient of stromal cell-derived factor 1a (SDF1a). In this study, we investigated whether a CXCR4-MSC infusion could protect hepatocytes and stimulate regeneration in 50% reduced size liver transplantation (RSLT). Rats that underwent 50% RSLT were randomly divided into 3 groups: a phosphate-buffered solution group (PBS), a green fluorescent protein (GFP)-MSC group, and a CXCR4-MSC group. Rats received 1 mL of PBS with or without a resuspension of GFP-MSCs or CXCR4-MSCs. The factors secreted by MSCs, the graft function, the apoptosis and proliferation of hepatocytes, the efficacy of MSC engraftment, and the expression of SDF1a, albumin (Alb), and cytokeratin 18 (CK18) in engrafted GFP-positive MSCs were assessed. A systemic infusion of GFP-MSCs led to a reduction of the release of liver injury biomarkers and apoptosis of hepatocytes; CXCR4 overexpression did not further reduce the liver injury. However, CXCR4 overexpression enhanced MSC engraftment in liver grafts, improved the effect on the proliferation of hepatocytes, and thus provided a significant 1-week survival benefit. SDF1a expression in grafts was elevated after transplanted CXCR4-MSCs were recruited to the remnant liver. However, engrafted MSCs did not express the markers of hepatocytes, including Alb and CK18, in vivo 168 hours after transplantation. CXCR4 overexpression enhanced the mobilization and engraftment of MSCs into small-for-size liver grafts, in which these cells promoted the early regeneration of the remnant liver not by direct differentiation but perhaps by a paracrine mechanism.
BackgroundThe therapeutic potential of mesenchymal stem cells (MSCs) has been highlighted recently for treatment of acute or chronic liver injury, by possibly differentiating into hepatocyte-like cells, reducing inflammation, and enhancing tissue repair. Despite recent progress, exact mechanisms of action are not clearly elucidated. In this study, we attempted to explore whether and how MSCs protected hepatocytes and stimulated allograft regeneration in small-for-size liver transplantation (SFSLT).MethodsSFSLT model was established with a 30% partial liver transplantation (30PLT) in rats. The differentiation potential and characteristics of bone marrow derived MSCs were explored in vitro. MSCs were infused transvenously immediately after graft implantation in therapy group. Expressions of apoptosis-, inflammatory-, anti-inflammatory-, and growth factor-related genes were measured by RT-PCR, activities of transcription factors AP-1 and NF-κB were analyzed by EMSA, and proliferative responses of the hepatic graft were evaluated by immunohistochemistry and western blot.ResultsMSCs were successfully induced into hepatocyte-like cells, osteoblasts and adipocytes in vitro. MSCs therapy could not only alleviate ischemia reperfusion injury and acute inflammation to promote liver regeneration, but also profoundly improve one week survival rate. It markedly up-regulated the mRNA expressions of HGF, Bcl-2, Bcl-XL, IL-6, IL-10, IP-10, and CXCR2, however, down-regulated TNF-α. Increased activities of AP-1 and NF-κB, as well as elevated expressions of p-c-Jun, cyclin D1, and proliferating cell nuclear antigen (PCNA), were also found in MSCs therapy group.ConclusionThese data suggest that MSCs therapy promotes hepatocyte proliferation and prolongs survival in SFSLT by reducing ischemia reperfusion injury and acute inflammation, and sustaining early increased expressions of c-Jun N-terminal Kinase, Cyclin D1, and NF-κB.
MicroRNAs are beneficial for cancer therapy as they can simultaneously downregulate multiple targets involved in diverse biological pathways related to tumor development. In papillary thyroid cancer, many microRNAs were identified as differentially expressed factors in tumor tissues. In another way, recent studies revealed cell proliferation, cell cycling, apoptosis, and autophagy are critical pathways controlling papillary thyroid cancer development and progression. As miR‐524‐5p was approved as a cancer suppressor targeting multiple genes in several types of cancer cells, this study aims to characterize the role of miR‐524‐5p in the thyroid cancer cell. The expression of miR‐524‐5p was decreased in the papillary thyroid cancer tissues and cell lines, while forkhead box E1 (FOXE1) and ITGA3 were increased. In the clinical case, expression of miR‐524‐5p, FOXE1, and ITGA3 were significantly correlated with papillary thyroid cancer development and progression. FOXE1 and ITGA3 were approved as direct targets of miR‐524‐5p. miR‐524‐5p could inhibit papillary thyroid cancer cell viability, migration, invasion, and apoptosis through targeting FOXE1 and ITGA3. Cell cycling and autophagy pathways were disturbed by downregulation of FOXE1 and ITGA3, respectively. Collectively, miR‐524‐5p targeting on FOXE1 and ITGA3 prevents thyroid cancer progression through different pathways including cell cycling and autophagy.
The aim of this study was to investigate the changes in splanchnic hemodynamics after LDLT and their relationship with graft regeneration. Eighteen patients with LDLT December 2006 and June 2008 were enrolled, and color Doppler ultrasonography was performed preoperatively and on postoperative days (PODs) 1, 3, 5, 7, 30, and 90 after transplantation. The changes in the portal blood flow mean velocity (PBV) and portal blood flow volume (PBF) were monitored, and their effects on hepatic function were observed simultaneously. Graft sizes were measured on PODs 7, 30, and 90 after the operation. The regeneration rates of grafts were calculated. PBF increased in the recipient group from 1081.17 +/- 277.50 to 2171.44 +/- 613.15 mL/minute, and PBV increased from 15.01 +/- 5.67 to 56.00 +/- 22.11 cm/s; they were both significantly higher than those in the donor group (P < 0.01). On POD 1, serum aspartic aminotransferase, alanine aminotransferase, and total bilirubin all peaked; however, these indices in patients with PBF/graft weight (GW) > 300 mL/minute . 100 g were significantly higher than those in patients with PBF/GW < 300 mL/minute . 100 g. Livers in the recipient group regenerated rapidly. The graft regeneration rate reached 119.40% +/- 28.21% as early as 1 month post-transplantation. PBF and PBV on PODs 1 and 3 were greatly related to liver regeneration at 30 days. The portal venous flow in patients with portal hypertension after LDLT showed a high perfusion state, which could promote graft regeneration, but PBF/GW after the operation should be controlled below 300 mL/minute . 100 g in order to protect grafts from hyperperfusion injury.
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