Cripto-1 overexpression is involved in the tumorigenesis of nasopharyngeal carcinoma

<p>Abstract</p> <p>Background</p> <p>Human Cripto-1, a member of the EGF-CFC family, is indispensable for early embryonic development. Cripto-1 plays an important oncogenic role during tumorigenesis and is overexpressed in a wide range of epithelial carcinomas, yet little is known about Cripto-1 in nasopharyngeal carcinoma (NPC). The aim of this study was to analyze the roles of Cripto-1 in the progression and clinical characteristics in NPC clinical samples and cell lines.</p> <p>Methods</p> <p>The expression of Cripto-1 at mRNA level was detected by the reverse transcription-polymerase chain reaction (RT-PCR) and real time RT-PCR, and western blot was used to examine the protein expression. Cripto-1 expression and its clinical characteristics were investigated by performing immunohistochemical analysis on a total of 37 NPC clinical tissue samples. Lentiviral vectors were constructed to get an efficient expression of anti-Cripto-1 siRNA in CNE-2 and C666-1 cells, with invalid RNAi sequence as control. After the inhibition of the endogenous Cripto-1, the growth, cell cycle and invasion of cells were detected by MTT, FACS and Boyden chamber assay respectively. Moreover, <it>in vivo</it>, the proliferation of the tumor cells was evaluated in xenotransplant nude mice model with whole-body visualizing instrument.</p> <p>Results</p> <p>The results of real-time RT-PCR and western blot showed that the expression level of Cripto-1 was markedly higher in NPC cell lines than that in the immortalized nasopharyngeal epithelial cell at both mRNA and protein levels. RT-PCR of 17 NPC tissues showed a high expression rate in 76.5% (13/17) cases. In an immunohistochemical study, Cripto-1 was found to express in 54.1% (20/37) cases of NPC. In addition, Cripto-1 overexpression was significantly associated with N classification (<it>p </it>= 0.034), distant metastasis (<it>p </it>= 0.036), and clinical stage (<it>p = </it>0.007). Inhibition of endogenous Cripto-1 by lentivirus-mediated RNAi silencing technique suppressed NPC cell growth and invasion <it>in vitro</it>. <it>In vivo</it>, the average weight (<it>p </it>= 0.026) and volume (<it>p </it>= 0.044) of tumor in CNE-2/GFP⁺/Cripto-1^-xenotransplant mice group were significantly lower than those in the control group. The Ki67 index was obviously lower in Cripto-1 RNAi treated tumors (<it>p </it>< 0.01).</p> <p>Conclusion</p> <p>Data of this study suggest that Cripto-1 overexpression is connected with the tumorigenesis and progression of NPC, lentivector-mediated RNAi might be feasible for the inhibition of the growth and invasion of NPC.</p

Effects of Different Materials on the Tribological Performance of PVD TiN Films under Starved Lubrication Regime

Grit blasting is one simple but effective method to modify the morphology of material surface and can improve the tribological performance. In this study, a thick TiN film was prepared by arc ion plating on the steel disk treated with grit blasting, and the rough surface coated solid film was obtained. The tribological properties of solid film against different materials were evaluated under starved lubrication regime. The results showed that the friction coefficients of rough titanium nitride (TiN) films were lower than those of rough steel disks exclude alumina ball under starved lubrication, and the wear rates of TiN film were negligible due to the high hardness of TiN film and small contact area. For four kinds of balls including steel ball, silicon nitride, zirconia, and alumina, the wear scar diameter of steel ball is biggest, and the wear scar diameters of other balls are small. The hardness of steel ball is less than others, which results in the easy abrasion and increases the contact area to reduce the pressure. So the friction coefficient of TiN against steel is low and steady

Metastasis is an Early Event in Mouse Mammary Carcinomas and is Associated with Cells Bearing Stem Cell Markers

Introduction: It is still uncertain whether metastasis is predominantly an early or late event in tumor progression. The detection of early metastases and cells responsible for the dissemination may therefore have significant clinical implications. Methods: Lung dissemination and/or metastasis were investigated in mice carrying the polyomavirus middle-T oncogene (PyMT) during different stages of mammary tumorigenesis using the colony forming assay. Immunocytochemical or immunohistochemical staining was used to identify subpopulations of cells responsible for lung dissemination and metastasis. Histological examination was used to show primary and metastatic tumors. The tumor-initiating and metastatic capacity of cells expressing stem cell markers was assessed in syngeneic wild-type (WT) mice whose mammary fat pads were injected with these cells. Results: Metastatic mammary epithelial cells were detected in the lungs of mice carrying the PyMT oncogene (MMT mice). These cells were observed early in breast tumorigenesis when the mammary tree appeared by histological inspection to be normal (or at a premalignant stage), suggesting the possession of disseminating and metastatic capacity even before full malignant transformation. Some of the disseminated cells and lung metastases displayed surface stem cell markers. These findings suggest that stem cells from apparently precancerous primary lesions could be a source of metastasis. Indeed, injection of lung tissue cells from MMT mice into syngeneic WT mice resulted in the formation of mammary tumors. These tumors resembled their parent mammary tumors in the MMT donors as well as grafted tumors derived from mammary tumor cells. Furthermore, when we injected lung tissue cells from GFP MMT mice into the fat pads of recipient WT mice, disseminated or metastatic GFP-expressing cells were detected in the lungs, lymph nodes and blood of the recipient WT mice. We finally identified a subpopulation of mammary epithelial/tumor cells expressing CD44 and Sca1 that was largely responsible for dissemination and metastasis in MMT mice. Conclusions: The tumorigenic and metastatic potential of a subpopulation of mammary epithelial/tumor cells in MMT mice is endowed relatively early in mammary neoplasms and suggests a potential role for cancer stem cell sub-populations in metastasis

Extensive analysis of D7S486 in primary gastric cancer supports TESTIN as a candidate tumor suppressor gene

<p>Abstract</p> <p>Background</p> <p>High frequency of loss of heterozygosity (LOH) was found at D7S486 in primary gastric cancer (GC). And we found a high frequency of LOH region on 7q31 in primary GC from China, and identified D7S486 to be the most frequent LOH locus. This study was aimed to determine what genes were affected by the LOH and served as tumor suppressor genes (TSGs) in this region. Here, a high-throughput single nucleotide polymorphisms (SNPs) microarray fabricated in-house was used to analyze the LOH status around D7S486 on 7q31 in 75 patients with primary GC. Western blot, immunohistochemistry, and RT-PCR were used to assess the protein and mRNA expression of TESTIN (TES) in 50 and 140 primary GC samples, respectively. MTS assay was used to investigate the effect of TES overexpression on the proliferation of GC cell lines. Mutation and methylation analysis were performed to explore possible mechanisms of TES inactivation in GC.</p> <p>Results</p> <p>LOH analysis discovered five candidate genes (<it>ST7</it>, <it>FOXP2</it>, <it>MDFIC</it>, <it>TES </it>and <it>CAV1</it>) whose frequencies of LOH were higher than 30%. However, only <it>TES </it>showed the potential to be a TSG associated with GC. Among 140 pairs of GC samples, decreased <it>TES </it>mRNA level was found in 96 (68.6%) tumor tissues when compared with matched non-tumor tissues (<it>p </it>< 0.001). Also, reduced TES protein level was detected in 36 (72.0%) of all 50 tumor tissues by Western blot (<it>p </it>= 0.001). In addition, immunohistochemical staining result was in agreement with that of RT-PCR and Western blot. Down regulation of TES was shown to be correlated with tumor differentiation (<it>p </it>= 0.035) and prognosis (<it>p </it>= 0.035, log-rank test). Its overexpression inhibited the growth of three GC cell lines. Hypermethylation of <it>TES </it>promoter was a frequent event in primary GC and GC cell lines. However, no specific gene mutation was observed in the coding region of the <it>TES </it>gene.</p> <p>Conclusions</p> <p>Collectively, all results support the role of <it>TES </it>as a TSG in gastric carcinogenesis and that <it>TES </it>is inactivated primarily by LOH and CpG island methylation.</p

Genotoxic stress induces Sca‐1‐expressing metastatic mammary cancer cells

We describe a cell damage‐induced phenotype in mammary carcinoma cells involving acquisition of enhanced migratory and metastatic properties. Induction of this state by radiation required increased activity of the Ptgs2 gene product cyclooxygenase 2 (Cox2), secretion of its bioactive lipid product prostaglandin E2 (PGE2), and the activity of the PGE2 receptor EP4. Although largely transient, decaying to low levels in a few days to a week, this phenotype was cumulative with damage and levels of cell markers Sca‐1 and ALDH1 increased with treatment dose. The Sca‐1+, metastatic phenotype was inhibited by both Cox2 inhibitors and PGE2 receptor antagonists, suggesting novel approaches to radiosensitization

Sub-picosecond photo-induced displacive phase transition in two-dimensional MoTe 2

Abstract: Photo-induced phase transitions (PIPTs) provide an ultrafast, energy-efficient way for precisely manipulating the topological properties of transition-metal ditellurides and can be used to stabilize a topological phase in an otherwise semiconducting material. Using first-principles calculations, we demonstrate that the PIPT in monolayer MoTe2 from the semiconducting 2H phase to the topological 1T′ phase can be triggered purely by electronic excitations that soften multiple lattice vibrational modes. These softenings, driven by a Peierls-like mechanism within the conduction bands, lead to structural symmetry breaking within sub-picosecond timescales, which is shorter than the timescale of a thermally driven phase transition. The transition is predicted to be triggered by photons with energies over 1.96 eV, with an associated excited carrier density of 3.4 × 1014 cm−2, which enables a controllable phase transformation by varying the laser wavelength. Our results provide insight into the underlying physics of the phase transition in 2D transition-metal ditellurides and show an ultrafast phase-transition mechanism for manipulation of the topological properties of 2D systems

Lenvatinib improves anti-PD-1 therapeutic efficacy by promoting vascular normalization via the NRP-1-PDGFRβ complex in hepatocellular carcinoma

IntroductionThe limited response to immune checkpoint blockades (ICBs) in patients with hepatocellular carcinoma (HCC) highlights the urgent need for broadening the scope of current immunotherapy approaches. Lenvatinib has been shown a potential synergistic effect with ICBs. This study investigated the optimal method for combining these two therapeutic agents and the underlying mechanisms.MethodsThe effect of lenvatinib at three different doses on promoting tissue perfusion and vascular normalization was evaluated in both immunodeficient and immunocompetent mouse models. The underlying mechanisms were investigated by analyzing the vascular morphology of endothelial cells and pericytes. The enhanced immune infiltration of optimal-dose lenvatinib and its synergistic effect of lenvatinib and anti-PD-1 antibody was further evaluated by flow cytometry and immunofluorescence imaging.ResultsThere was an optimal dose that superiorly normalized tumor vasculature and increased immune cell infiltration in both immunodeficient and immunocompetent mouse models. An adequate concentration of lenvatinib strengthened the integrity of human umbilical vein endothelial cells by inducing the formation of the NRP-1-PDGFRβ complex and activating the Crkl-C3G-Rap1 signaling pathway in endothelial cells. Additionally, it promoted the interaction between endothelial cells and pericytes by inducing tyrosine-phosphorylation in pericytes. Furthermore, the combination of an optimal dose of lenvatinib and an anti-PD-1 antibody robustly suppressed tumor growth.ConclusionsOur study proposes a mechanism that explains how the optimal dose of lenvatinib induces vascular normalization and confirms its enhanced synergistic effect with ICBs