CA9 transcriptional expression determines prognosis and tumour grade in tongue squamous cell carcinoma patients

CA9 is a member of the carbonic anhydrases’ family, that is often expressed in cancer cells under hypoxic condition. However, the role of CA9 in the molecular mechanisms of tongue squamous cell carcinoma (TSCC) pathogenesis remains unclear. CA9 expression was analysed using the TCGA database, and its influence on survival was performed using Kaplan-Meier, LASSO and COX regression analyses. The correlation between CA9 and immune infiltration was investigated by CIBERSORT and ESTIMATE. Moreover, the relationship between CA9 expression and downstream molecular regulation pathways was analysed by GSEA, GO and WGCNA. CA9 expression correlated with clinical prognosis and tumour grade in TSCC. Moreover, CA9 expression potentially contributes to the regulation of cancer cell differentiation and mediates tumour-associated genes and signalling pathways, including apoptosis, hypoxia, G2M checkpoint, PI3K/AKR/mTOR signalling and TGF-beta signalling pathways. However, the follicular helper T cells, regulatory T cells, immune and stromal scores showed no significance between high and low CA9 expression groups. These findings suggested that CA9 plays a critical role of TSCC prognosis and tumour grade. CA9 expression significantly correlated with the regulation of cell differentiation, various oncogenes and cancer-associated pathways.     

Differential response to hepatic differentiation stimuli of amniotic epithelial cells isolated from four regions of the amniotic membrane

Human Amniotic Epithelial Cells (hAEC) isolated from term placenta are a promising source for regenerative medicine. However, it has long been debated whether the hAEC population consists of heterogeneous or homogeneous cells. In a previous study, we investigated the characteristics of hAEC isolated from four different regions of the amniotic membrane finding significant heterogeneity. The aim of this study was to evaluate the hepatic differentiation capability of hAEC isolated from these four regions. Human term placentae were collected after caesarean section and hAEC were isolated from four regions of the amniotic membrane (R1-R4, according to their relative distance from the umbilical cord) and treated in hepatic differentiation conditions for 14 days. hAEC-derived hepatocyte-like cells showed marked differences in the expression of hepatic markers: R4 showed higher levels of Albumin and Hepatocyte Nuclear Factor (HNF) 4α whereas R1 expressed higher Cytochrome P450 enzymes, both at the gene and protein level. These preliminary results suggest that hAEC isolated from R1 and R4 of the amniotic membrane are more prone to hepatic differentiation. Therefore, the use of hAEC from a specific region of the amniotic membrane should be taken into consideration as it could have an impact on the outcome of therapeutic applications.     

Human endothelial cells produce a plasminogen activator inhibitor and a tissue-type plasminogen activator-inhibitor complex

Serum-free conditioned media and cell extracts from cultured human umbilical vein endothelial cells were analyzed for plasminogen activator by SDS-polyacrylamide gel electrophoresis and enzymography on fibrin-indicator gels. Active bands of free and complexed tissue-type plasminogen activator (t-PA) or urokinase-type plasminogen activator (u-PA) were identified by the incorporation of specific antibodies against, respectively, t-PA or u-PA in the indicator gel. The endothelial cells predominantly released a high-molecular-weight t-PA (95000–135000). This t-PA form was converted to M_r-72000 t-PA by 1.5 M NH₄OH/39 mM SDS. A component with high affinity for both t-PA and u-PA could be demonstrated in serum-free conditioned medium and endothelial cell extract. The complex between this component and M_r-72000 t-PA comigrated with high-molecular-weight t-PA. From the increase in M_r of t-PA or u-PA upon complex formation, the M_r of the endothelial cell component was estimated to be 50000–70000. The reaction between t-PA or u-PA and the plasminogen activator-binding component was blocked by 5 mM p-aminobenzamidine, while the complexes, once formed, could be cleaved by 1.5 M NH₄OH/39 mM SDS. These observations indicated that the active center of plasminogen activator was involed in the complex formation. It was further noted that serum-free conditioned medium of endothelial cell extract inhibited plasminogen activator activity when assayed by the fibrin-plate method. Evidence is provided that the plasminogen activator-binding component was different from a number of the known plasma serine proteinase inhibitors, the placenta inhibitor and the fibroblast surface protein, proteinase-nexin. We conclude that cultured endothelial cells produce a rapid inhibitor of u-PA and t-PA as well as a t-PA-inhibitor complex.     

Human umbilical cord mesenchymal stem cells as treatment of adjuvant rheumatoid arthritis in a rat model

AIM:To investigate the effect of human umbilical cord stem cells,both mesenchymal and hematopoietic(CD34+),in the treatment of arthritis.METHODS:Mesenchymal stem cells(MSCs) and hematopoietic(CD34+) stem cells(HSC) were isolated from human umbilical cord blood obtained from the umbilical cord of healthy pregnant donors undergoing fullterm normal vaginal delivery.MSC,HSC,methotrexate(MTX) and sterile saline were injected intra-articularly into the rat hindpaw with complete freunds adjuvant(CFA) induced arthritis after the onset of disease(day 34),when arthritis had become well established(arthritis score ≥ 2).Arthritic indices were evaluated and the levels of interleukin(IL)-1,tumor necrosis factor(TNF)-α and interferon(IFN)-γ and anti-inflammatory cytokine IL-10 in serum were determined using enzyme-linked immunosorbent assay.Animals of all groups were sacrificed 34 d after beginning treatment,except positive control(PC) which was sacrificed at 10,21 and 34 d for microscopic observation of disease progression.We used hematoxylin,eosin and Masson's trichrome stains for histopathological examination of cartilage and synovium.RESULTS:The mean arthritis scores were similar in all groups at 12 and 34 d post immunization,with no statistical significant difference.Upon the injection of stem cells(hematopoietic and mesenchymal),the overall arthritis signs were significantly improved around 21 d after receiving the injection and totally disappeared at day 34 post treatment in MSC group.Mean hindpaw diameter(mm) in the MSC rats was about half that of the PC and MTX groups(P = 0.007 and P = 0.021,respectively) and 0.6 mm less than the HSC group(P = 0.047),as indicated by paw swelling.Associated with these findings,serum levels of TNF-α,IFN-γ and IL-1 decreased significantly in HSC and MSC groups compared to PC and MTX groups(P 0.05),while the expression of IL-10 was increased.Histopathological examination with H and E stain revealed that the MTX treated group showed significant reduction of leucocytic infiltrate and hypertrophy of the synovial tissue with moderate obliteration of the joint cavity.Stem cells treated groups(both hematopoietic CD34+ and mesenchymal),showed significant reduction in leucocytic infiltrate and hypertrophy of the synovial tissue with mild obliteration of the joint cavity.With Masson's trichrome,stain sections from the PC group showed evidence of vascular edema of almost all vessels within the synovium in nearly all arthritic rats.Vacuoles were also visible in the outer vessel wall.The vessel became hemorrhagic and finally necrotic.In addition,there was extensive fibrosis completely obliterating the joint cavity.The mean color area percentage of collagen in this group was 0.324 ± 0.096,which was significantly increased when compared to the negative control group.The mean color area percentage of collagen in hematopoietic CD34+ and mesenchymal groups was 0.176 ± 0.0137 and 0.174 ± 0.0197 respectively,which showed a marked decrement compared to the PC group,denoting a mild increase in synovial tissue collagen fibers.CONCLUSION:MSC enhance the efficacy of CFAinduced arthritis treatment,most likely through the modulation of the expression of cytokines and amelioration of pathological changes in joints.     

Periostin Promotes Colorectal Tumorigenesis through Integrin-FAK-Src Pathway-Mediated YAP/TAZ Activation

1. Download : Download high-res image (201KB)
2. Download : Download full-size image

     

Ehrlich ascites tumour cells become refractory to alpha-difluoromethylornithine at a certain stage of growth

When Ehrlich ascites tumour cells are induced to proliferate by serum stimulation, the ornithine decarboxylase (ODC) activity increases rapidly and reaches two to three peaks during the first 24 h. Inhibition of the first peak in ODC activity (occurring at 4 h) by adding alpha-difluoromethylornithine (DFMO) within 2 h of serum stimulation, results in maximal growth inhibition. Under these conditions, similar degrees of polyamine depletion are achieved. When DFMO is added 3 h after seeding, however, enough polyamines have already accumulated during the initial burst in ODC activity to reduce the antiproliferative effect of the drug. The antiproliferative effect is further reduced when DFMO is added 6 h after seeding. When DFMO is added 23 h after seeding, i.e. after maximal accumulation of polyamines, there is no inhibition of cell proliferation. These findings are important to consider both when designing experimental as well as clinical regimens for this drug.     

Immunocytochemical localization of tubulin with colloidal gold in cilia of rabbit tracheal epithelial cultures

Ciliated tracheal epithelia cell cultures were investigated immunocytochemically with anti-tubulin and colloidal gold. When rabbit tracheal cultures were fixed in paraformaldehyde, treated with acetone, anti-tubulin and a second antibody coupled to FITC, fluorescence was associated with cytoskeletal and axonemal microtubules. Cilia covering the apical surface of the ciliated tracheal cells fluoresced very brightly thus facilitating identification of this cell type. Electron microscopy of tracheal cultures fixed as above, treated with Triton-X 100 and incubated in anti-tubulin and protein A coupled to colloidal gold resulted in the highly specific localization of tubulin in ciliary axonemes and basal bodies. Omission of primary or secondary antibody resulted in extremely low levels of fluorescence while no colloidal gold particles could be detected in cultures at the electron microscopy level when rabbit anti-tubulin was omitted.     

Bioelectrochemical fuel cells

In the past 20 years, inorganic fuel cells have been transformed from novelty devices to practical energy transfer-energy storage units. However, the advantage of the high operating efficiency afforded by these fuel cells is partially offset by (a) the limited viability and high cost of the catalysts, (b) the highly corrosive electrolytes, and (c) the elevated operating temperatures. The possibility exists to reduce some of these problems through the development of bioelectrochemical fuel cells. Such biological/electrochemical systems incorporate either microorganisms or enzymes as an active component within the specified electrode compartments. Recent studies with microorganisms as part of the anode compartment have been aimed at defining the mechanism of the observed electrochemical reactions. Recent investigations on the use of cell-free enzyme preparations in the electrode compartments have dealt primarily with developing methodology and defining mechanisms for enhancing the rate of electron transfer from the enzyme-cofactor active site to the solid electrode surface. Applications of this developing technology have been envisioned for analytical chemistry, medical devices, energy transfer, electrochemical synthesis, and detoxification. In this review, the theory and problems of bioelectrochemical fuel cells are described and related to research, both recent and proposed, for the practical development of this area.