Activation of the Canonical Wnt Signaling Pathway Induces Cementum Regeneration

Canonical Wnt signaling is important in tooth development but it is unclear whether it can induce cementogenesis and promote the regeneration of periodontal tissues lost because of disease. Therefore, the aim of this study is to investigate the influence of canonical Wnt signaling enhancers on human periodontal ligament cell (hPDLCs) cementogenic differentiation in vitro and cementum repair in a rat periodontal defect model. Canonical Wnt signaling was induced by (1) local injection of lithium chloride; (2) local injection of sclerostin antibody; and (3) local injection of a lentiviral construct overexpressing β‐catenin. The results showed that the local activation of canonical Wnt signaling resulted in significant new cellular cementum deposition and the formation of well‐organized periodontal ligament fibers, which was absent in the control group. In vitro experiments using hPDLCs showed that the Wnt signaling pathway activators significantly increased mineralization, alkaline phosphatase (ALP) activity, and gene and protein expression of the bone and cementum markers osteocalcin (OCN), osteopontin (OPN), cementum protein 1 (CEMP1), and cementum attachment protein (CAP). Our results show that the activation of the canonical Wnt signaling pathway can induce in vivo cementum regeneration and in vitro cementogenic differentiation of hPDLCs. © 2014 American Society for Bone and Mineral Research © 2015 American Society for Bone and Mineral Research     

caveolin-1通过阻断PI3K/Akt信号的激活抑制胰腺癌细胞增殖

目的研究caveolin-1对胰腺癌Panc1细胞在体外生长和增殖的影响,并初步探讨其机理。方法选用人类胰腺癌Panc1细胞,通过基因转染技术培育过表达caveolin-1细胞株Panc1/cav-1作为实验组,空载体细胞株Panc1/vec和亲本细胞株Panc1作为对照组。Western blot方法检测各组细胞内caveolin-1、Akt和p-Akt的表达,绘制细胞生长曲线并计算细胞倍增时间,流式细胞仪分析细胞周期,软琼脂集落形成实验检测细胞增殖克隆的能力。结果①caveolin-1在实验组细胞中稳定表达,其表达量明显高于对照组细胞(P<0.01),而对照组的Panc1/vec细胞和Panc1细胞之间差异无统计学意义(P>0.05)。②实验组细胞的生长速度明显慢于对照组细胞(P<0.05),其倍增时间明显长于对照组细胞(P<0.01)。③细胞周期显示,实验组细胞被抑制于G0/G1期(P<0.05),进入S期的细胞比率明显减少(P<0.01),实验组细胞的增殖指数较对照组明显降低(P<0.01)。④实验组细胞在软琼脂中形成的集落数目较对照组明显减少(P<0.01),体积较小。⑤实验组细胞中Akt表达量与对照组之间差异无统计学意义(P>0.05),而实验组细胞中p-Akt表达量明显低于对照组(P<0.05)。结论 caveo-lin-1通过抑制PI3K/Akt信号激活抑制Panc1细胞生长和增殖。     

IGF信号通路和雄激素受体在前列腺癌发展过程中的相互作用

靶点的抗体应用于临床研究.本文将分析前列腺癌细胞中IGF-IR信号通路如何调节AR结构,从而改变AR活性的研究进展,为以IGF-IR为靶点的治疗AIPC的前景作一综述.     

IGF信号通路和雄激素受体在前列腺癌发展过程中的相互作用

靶点的抗体应用于临床研究.本文将分析前列腺癌细胞中IGF-IR信号通路如何调节AR结构,从而改变AR活性的研究进展,为以IGF-IR为靶点的治疗AIPC的前景作一综述.     

The Hypoxic Environment in Tumor-Stromal Cells Accelerates Pancreatic Cancer Progression via the Activation of Paracrine Hepatocyte Growth Factor/c-Met Signaling

Background

Pancreatic cancer is one of the representative solid tumors, in which the hypoxic microenvironment plays a crucial role in malignant progression. We previously demonstrated that tumor-stromal interaction under hypoxia enhances the invasiveness of pancreatic cancer cells through hepatocyte growth factor (HGF)/c-Met signaling.

Methods

We investigated the immunohistochemical expression of hypoxia inducible factor-1α (HIF-1α) c-Met, and HGF in both cancer and stromal cells using 41 pancreatic cancer tissue specimens, and tried to identify any correlations with the clinical features and survival.

Results

Positive staining for HIF-1α was observed in both pancreatic cancer and the surrounding stromal cells in more than 30% of the cases, and it significantly correlated with lymph node metastasis (P < .05). A significant correlation was observed between the expression of HIF-1α and HGF in stromal cells (P < .05). In addition, the c-Met expression in cancer cells was found to significantly correlate with the HGF expression in not only cancer but also stromal cells. The disease-free survival rates of the patients with HIF-1α in cancer, stromal, c-Met in cancer, and an HGF expression in stromal cells was significantly worse than those without such expressions (P < .05).

Conclusions

These data suggest that the HGF/c-Met signaling via HIF-1α ?may therefore negatively affect the prognosis in patients with pancreatic cancer, and targeting tumor stroma under hypoxia might thus be potentially useful as a novel therapy for this cancer.

     

mTOR Signaling Pathway Is a Target for the Treatment of Colorectal Cancer

Background  mTOR signaling has been suggested to be an important factor involved in tumorigenesis, but its role in human colorectal cancer (CRC) has not been completely elucidated. Herein, the purpose of this study was to analyze the distribution pattern of mTOR signaling components in CRC and adenoma and to determine whether targeted inhibition of mTOR could be a potential therapeutic strategy for CRC. Methods  Immunohistochemical analysis was performed on human CRC and adenoma for mTOR signaling components, including mTOR, p70s6 K, and 4EBP1. HCT116 and SW480 human CRC cell lines were treated with siRNA directed against mTOR, and cell viability, cell cycle, and apoptosis were assessed. HCT116 and SW480 cells were injected into athymic nude mice to establish a CRC xenograft model. Mice were randomly transfected with either nontargeting control or mTOR siRNA, and tumor volume, mTOR signaling activity, and apoptosis were evaluated. Results  mTOR signaling components, including mTOR, p70s6 K, and 4EBP1, were highly activated in glandular elements of CRC and colorectal adenomas with high-grade intraepithelial neoplasia (HIN), with a correlation between staining intensity and depth of infiltration in CRC. Inhibition of mTOR expression using a specific mTOR siRNA resulted in considerably decreased in vitro and in vivo cell growth. Conclusions  mTOR signaling is associated with the clinical pathological parameters of human CRC. siRNA-mediated gene silencing of mTOR may be a novel therapeutic strategy for CRC.     

A Novel Osteogenic Oxysterol Compound for Therapeutic Development to Promote Bone Growth: Activation of Hedgehog Signaling and Osteogenesis Through Smoothened Binding

Osteogenic factors are often used in orthopedics to promote bone growth, improve fracture healing, and induce spine fusion. Osteogenic oxysterols are naturally occurring molecules that were shown to induce osteogenic differentiation in vitro and promote spine fusion in vivo. The purpose of this study was to identify an osteogenic oxysterol more suitable for clinical development than those previously reported, and evaluate its ability to promote osteogenesis in vitro and spine fusion in rats in vivo. Among more than 100 oxysterol analogues synthesized, Oxy133 induced significant expression of osteogenic markers Runx2, osterix (OSX), alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OCN) in C3H10T1/2 mouse embryonic fibroblasts and in M2‐10B4 mouse marrow stromal cells. Oxy133‐induced activation of an 8X‐Gli luciferase reporter, its direct binding to Smoothened, and the inhibition of Oxy133‐induced osteogenic effects by the Hedgehog (Hh) pathway inhibitor, cyclopamine, demonstrated the role of Hh pathway in mediating osteogenic responses to Oxy133. Oxy133 did not stimulate osteogenesis via BMP or Wnt signaling. Oxy133 induced the expression of OSX, BSP, and OCN, and stimulated robust mineralization in primary human mesenchymal stem cells. In vivo, bilateral spine fusion occurred through endochondral ossification and was observed in animals treated with Oxy133 at the fusion site on X‐ray after 4 weeks and confirmed with manual assessment, micro‐CT (µCT), and histology after 8 weeks, with equal efficiency to recombinant human bone morphogenetic protein‐2 (rhBMP‐2). Unlike rhBMP‐2, Oxy133 did not induce adipogenesis in the fusion mass and resulted in denser bone evidenced by greater bone volume/tissue volume (BV/TV) ratio and smaller trabecular separation. Findings here suggest that Oxy133 has significant potential as an osteogenic molecule with greater ease of synthesis and improved time to fusion compared to previously studied oxysterols. Small molecule osteogenic oxysterols may serve as the next generation of bone anabolic agents for therapeutic development. © 2014 American Society for Bone and Mineral Research.     

Prognostic Value of Diametrically Polarized Tumor-Associated Macrophages in Renal Cell Carcinoma

Background

As the most abundant tumor-infiltrating immune cells, tumor-associated macrophages (TAMs) are significant for fostering tumor progression. CD68⁺ TAMs display diversely polarized programs comprising CD11c⁺ proinflammatory macrophages (M1) and CD206⁺ immunosuppressive macrophages (M2). The aim of this study was to determine the survival impact of diametrically polarized TAMs in clear-cell renal cell carcinoma (ccRCC) and their application to stratification of patients according to their prognostic values.

Methods

The study included 185 consecutive patients with ccRCC who underwent nephrectomy between 1999 and 2001. CD68⁺ total and diametrically polarized (CD11c⁺ M1 and CD206⁺ M2) TAM densities were assessed by immunohistochemistry, and the relationships with clinicopathologic features and prognosis were evaluated.

Results

Low CD11c⁺ TAM density and high CD206⁺ TAM density were associated with reduced cancer-specific survival (P = 0.043 and P = 0.017, respectively), whereas CD68⁺ TAM density only had borderline prognostic significance (P = 0.062). Furthermore, combined analysis of CD11c⁺ and CD206⁺ TAMs (CD11c/CD206 signature) had a better power to predict patients’ outcome (P = 0.010). Together with TNM stage, tumor necrosis, and performance status, CD11c/CD206 signature was an independent prognostic factor (P = 0.010). When applied to the University of California Integrated Staging System intermediate-/high-risk group for localized ccRCC, CD11c/CD206 signature could further distinguish patients with dismal prognosis (P = 0.004).

Conclusions

Intratumoral balance of diametrically polarized TAMs is a novel independent predictor for survival in patients with ccRCC. Tipping the balance toward an antitumoral phenotype might be a promising target of postoperative adjuvant therapy.     

Activation of Sympathetic Signaling in Macrophages Blocks Systemic Inflammation and Protects against Renal Ischemia-Reperfusion Injury

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TWEAK Signaling Pathway Blockade Slows Cyst Growth and Disease Progression in Autosomal Dominant Polycystic Kidney Disease

BackgroundIn autosomal dominant polycystic kidney disease (ADPKD), cyst development and enlargement lead to ESKD. Macrophage recruitment and interstitial inflammation promote cyst growth. TWEAK is a TNF superfamily (TNFSF) cytokine that regulates inflammatory responses, cell proliferation, and cell death, and its receptor Fn14 (TNFRSF12a) is expressed in macrophage and nephron epithelia.MethodsTo evaluate the role of the TWEAK signaling pathway in cystic disease, we evaluated Fn14 expression in human and in an orthologous murine model of ADPKD. We also explored the cystic response to TWEAK signaling pathway activation and inhibition by peritoneal injection.ResultsMeta-analysis of published animal-model data of cystic disease reveals mRNA upregulation of several components of the TWEAK signaling pathway. We also observed that TWEAK and Fn14 were overexpressed in mouse ADPKD kidney cysts, and TWEAK was significantly high in urine and cystic fluid from patients with ADPKD. TWEAK administration induced cystogenesis and increased cystic growth, worsening the phenotype in a murine ADPKD model. Anti-TWEAK antibodies significantly slowed the progression of ADPKD, preserved renal function, and improved survival. Furthermore, the anti-TWEAK cystogenesis reduction is related to decreased cell proliferation–related MAPK signaling, decreased NF-κB pathway activation, a slight reduction of fibrosis and apoptosis, and an indirect decrease in macrophage recruitment.ConclusionsThis study identifies the TWEAK signaling pathway as a new disease mechanism involved in cystogenesis and cystic growth and may lead to a new therapeutic approach in ADPKD.     

胰腺发育和胰腺癌中Notch信号通路作用的研究进展

目的探讨Notch信号通路在胰腺发育和胰腺癌发生、发展中所起的作用。方法复习国内、外相关文献并进行综述、分析。结果 Notch信号通路在胰腺早期发育中可能起着维持胰腺上皮细胞处于祖细胞状态,延迟其分化直至时机成熟的作用;Notch信号通路在胰腺癌的起始、发生及进展中均明显活化。结论 Notch信号通路在胰腺发育中起重要作用;持续激活的Notch信号通路促进了胰腺癌的发展,且可能为胰腺癌发生的始动因素之一。     

P120连环蛋白/转录抑制因子Kaiso与Wnt信号通路在肿瘤发病机制中的作用

异常的经典的Wnt信号通路的激活可以促进肿瘤的发生。P120连环蛋白/转录抑制因子Kaiso对Wnt信号通路的靶基因具有调控作用,影响Wnt信号通路的活动,从而影响肿瘤发生的过程。     

Tumor-Associated Macrophage Correlated with Angiogenesis and Progression of Mucoepidermoid Carcinoma of Salivary Glands

Background   There is considerable controversy about whether tumor-associated macrophages (TAMs) promote or inhibit tumor progression. The present study examined the clinicopathologic significance of TAMs and their association with tumor angiogenesis, cell proliferation, and apoptosis in mucoepidermoid carcinoma (MEC). The potential effect of TAMs on cancer cells was also investigated. Methods  CD68, CD34, Ki-67, and vascular endothelial growth factor (VEGF)-A immunohistochemical staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) were applied to samples from 41 MEC patients. The biologic effect of macrophages on MEC cancer cells was examined in a co-culture system. Results  The proliferation index (PI) was 11.7 ± 5.9%, and the apoptotic index (AI) was 4.1 ± 2.3% in cancer patients. PI was significantly correlated with tumor grade, and the PI/AI ratio was significantly correlated with tumor size and stage. The distributions of intratumoral TAMs and microvessel density (MVD) were heterogeneous. TAM count associated strongly with tumor size, grading, and MEC staging. A greater intratumoral MVD was observed frequently in patients with large, intermediate/high-grade, and advanced-stage tumors. VEGF-A expression correlated significantly with tumor size and stage. MVD count was closely associated with TAM count and VEGF-A expression. Co-cultured cancer cells with macrophages increased migration and invasion ability of cancer cells. Co-cultured endothelial cells with cancer cells elevated VEGF-A expression, proliferation, and migration, and tube formation of endothelial cells. Conclusion  Our data suggest that TAMs play a tumor-promoting role in MEC. The TAM count, intratumoral MVD, and PI/AI ratio are potentially useful markers of progression in patients with MEC.