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1.
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Systemic deletion of senescent cells leads to robust improvements in cognitive, cardiovascular, and whole‐body metabolism, but their role in tissue reparative processes is incompletely understood. We hypothesized that senolytic drugs would enhance regeneration in aged skeletal muscle. Young (3 months) and old (20 months) male C57Bl/6J mice were administered the senolytics dasatinib (5 mg/kg) and quercetin (50 mg/kg) or vehicle bi‐weekly for 4 months. Tibialis anterior (TA) was then injected with 1.2% BaCl2 or PBS 7‐ or 28 days prior to euthanization. Senescence‐associated β‐Galactosidase positive (SA β‐Gal+) cell abundance was low in muscle from both young and old mice and increased similarly 7 days following injury in both age groups, with no effect of D+Q. Most SA β‐Gal+ cells were also CD11b+ in young and old mice 7‐ and 14 days following injury, suggesting they are infiltrating immune cells. By 14 days, SA β‐Gal+/CD11b+ cells from old mice expressed senescence genes, whereas those from young mice expressed higher levels of genes characteristic of anti‐inflammatory macrophages. SA β‐Gal+ cells remained elevated in old compared to young mice 28 days following injury, which were reduced by D+Q only in the old mice. In D+Q‐treated old mice, muscle regenerated following injury to a greater extent compared to vehicle‐treated old mice, having larger fiber cross‐sectional area after 28 days. Conversely, D+Q blunted regeneration in young mice. In vitro experiments suggested D+Q directly improve myogenic progenitor cell proliferation. Enhanced physical function and improved muscle regeneration demonstrate that senolytics have beneficial effects only in old mice.  相似文献   

3.

Purpose

The current study examines the effect of fever-range hyperthermia and mild hypothermia on human cancer cells focusing on cell viability, proliferation and HSP90 expression.

Materials and Methods

A549 and H1299 lung carcinoma, MCF7 breast adenocarcinoma, U87MG and T98G glioblastoma, DU145 and PC3 prostate carcinoma and MRC5 normal fetal lung fibroblasts cell lines were studied. After 3-day exposure to 34°C, 37°C and 40°C, cell viability was determined. Cell proliferation (ki67 index), apoptosis (Caspase 9) and HSP90 expression was studied by confocal microscopy.

Results

Viability/proliferation experiments demonstrated that MRC5 fibroblasts were extremely sensitive to hyperthermia, while they were the most resistant to hypothermia. T98G and A549 were thermo-tolerant, the remaining being thermo-sensitive to a varying degree. Nonetheless, as a universal effect, hypothermia reduced viability/proliferation in all cell lines. Hyperthermia sharply induced Caspase 9 in the U87MG most thermo-sensitive cell line. In T98G and A549 thermo-tolerant cell lines, the levels of Caspase 9 declined. Moreover, hyperthermia strongly induced the HSP90 levels in T98G, whilst a sharp decrease was recorded in the thermo-sensitive PC3 and U87MG cell lines. Hyperthermia sensitized thermo-sensitive cancer cell lines to cisplatin and temozolomide, whilst its sensitizing effect was diminished in thermo-tolerant cell lines.

Conclusions

The existence of thermo-tolerant and thermo-sensitive cancer cell lines was confirmed, which further encourages research to classify human tumor thermic predilection for patient stratification in clinical trials. Of interest, mild hypothermia had a universal suppressing effect on cancer cell proliferation, further supporting the radio-sensitization hypothesis through reduction of oxygen and metabolic demands.  相似文献   

4.
We have previously shown that fibroblast expression of α11β1 integrin stimulates A549 carcinoma cell growth in a xenograft tumor model. To understand the molecular mechanisms whereby a collagen receptor on fibroblast can regulate tumor growth we have used a 3D heterospheroid system composed of A549 tumor cells and fibroblasts without (α11+/+) or with a deletion (α11-/-) in integrin α11 gene. Our data show that α11-/-/A549 spheroids are larger than α11+/+/A549 spheroids, and that A549 cell number, cell migration and cell invasion in a collagen I gel are decreased in α11-/-/A549 spheroids. Gene expression profiling of differentially expressed genes in fibroblast/A549 spheroids identified CXCL5 as one molecule down-regulated in A549 cells in the absence of α11 on the fibroblasts. Blocking CXCL5 function with the CXCR2 inhibitor SB225002 reduced cell proliferation and cell migration of A549 cells within spheroids, demonstrating that the fibroblast integrin α11β1 in a 3D heterospheroid context affects carcinoma cell growth and invasion by stimulating autocrine secretion of CXCL5. We furthermore suggest that fibroblast α11β1 in fibroblast/A549 spheroids regulates interstitial fluid pressure by compacting the collagen matrix, in turn implying a role for stromal collagen receptors in regulating tensional hemostasis in tumors. In summary, blocking stromal α11β1 integrin function might thus be a stroma-targeted therapeutic strategy to increase the efficacy of chemotherapy.  相似文献   

5.
The role of peroxisome proliferator – activated receptor- δ (PPAR δ) gene in colon carcinogenesis remains highly controversial. Here, we established nude mice xenograft model using a human colon cancer cell line KM12C either with PPAR δ silenced or normal. The xenografts in PPAR δ-silenced group grew significantly larger and heavier with less differentiation, promoted cell proliferation, increased expression of vascular endothelial growth factor (VEGF) and similar apoptosis index compared with those of PPAR δ-normal group. After treated with the specific VEGF inhibitor bevacizumab, the capacities of growth and proliferation of xenografts were decreased in both groups while still significantly higher in PPAR δ-silenced group than in PPAR δ-normal group. Administration of PPAR δ agonist significantly decreased VEGF expression in PPAR δ-normal KM12C cells but not in PPAR δ-silenced cells. These findings demonstrate that, knockdown of PPAR δ promotes the growth of colon cancer by inducing less differentiation, accelerating the proliferation and VEGF expression of tumor cells in vivo, and reduces tumor sensitivity to bevacizumab. This study indicates that PPAR δ attenuates colon carcinogenesis.  相似文献   

6.
We have examined the concentration of β-carotene in the fat of isolated abdominal subcutaneous adipocytes obtained from lean (BMI<23 kg/m2), non-obese with higher BMI (23≤BMI<28 kg/m2), obese (BMI≥28 kg/m2), and from a group of obese subjects with type 2 diabetes. The concentration of β-carotene was 50% lower in the adipocytes from the obese and obese/diabetic groups compared with the lean and non-obese groups. Interestingly, the total amount of β-carotene in the adipocyte stores of each subject was constant among all groups. Triacylglycerol constituted 92±1% (by weight) of the adipocyte lipids in the lean group and this was increased to 99±2% in the obese group with diabetes (p<0.05). The concentration of cholesteryl esters was in all cases <0.1 g per 100 g of total lipids, demonstrating that mature human adipocytes have negligible stores of cholesteryl ester. Our findings demonstrate that adipocyte concentrations of β-carotene are reduced in obese subjects. The lower concentrations in adipocytes from subjects with type 2 diabetes apparently reflect subjectś obesity. Our finding that whole-body stores of β-carotene in adipocytes are constant raises new questions regarding what function it serves, as well as the mechanisms for maintaining constant levels in the face of varied adipose tissue mass among individuals over a period of time.  相似文献   

7.

Aims

It has been shown that nerve growth factor-β (NGF-β) promoted the initiation and progression of many tumors, and we have previously demonstrated that the expression of NGF-β was associated with tumor stage, nerve infiltration and lymph node metastasis in human hilar cholangiocarcinoma. However, whether NGF-β promotes tumor progression in human cholangiocarcinoma requires further investigation. Therefore, we aimed to determine the effects of NGF-β on the progression of human cholangiocarcinoma.

Methods

Human cholangiocarcinoma QBC939 stable cell lines with over-expressed or silenced NGF-β genes were generated with pEGFP-N1-NGF-β and pGPU6/GFP/Neo-NGF-β-shRNA recombinant plasmids. Cell proliferation assay, colony formation assay, cell cycle analysis, apoptosis assay and tumorigenicity assay were performed to evaluate the role of NGF-β in the progression of human cholangiocarcinoma. In addition, human lymphatic endothelial cells were co-cultured with QBC939 culture supernatants, and the cell proliferation and migration abilities of the lymphatic endothelial cells were evaluated.

Results

Forced expression of NGF-β in QBC939 cell lines promoted proliferation, colony formation and tumorigenicity in these cells and inhibited the apoptosis. However, down-regulation of NGF-β inhibited proliferation, colony formation and tumorigenicity, and increased the apoptotic rate of QBC939 cells. In addition, the NGF-β gain-of-function induced a high expression of vascular endothelial growth factor C and enhanced the proliferation and migration of lymphatic endothelial cells, while NGF-β loss-of-function showed opposite effects.

Conclusions

We concluded that NGF-β promoted tumor progression in human cholangiocarcinoma QBC939 cells. Our results provided a new concept to understand the role of NGF-β in cholangiocarcinoma progression, and might provide important information for the development of new targeted therapies in human cholangiocarcinoma.  相似文献   

8.
Human γδ T cells are potent effectors against glioma cell lines in vitro and in human/mouse xenograft models of glioblastoma, however, this effect has not been investigated in an immunocompetent mouse model. In this report, we established GL261 intracranial gliomas in syngeneic WT C57BL/6 mice and measured circulating γδ T cell count, phenotype, Vγ/Vδ repertoire, tumor histopathology, NKG2D ligands expression, and T cell invasion at day 10–12 post-injection and at end stage. Circulating γδ T cells transiently increased and upregulated Annexin V expression at post-tumor day 10–12 followed by a dramatic decline in γδ T cell count at end stage. T cell receptor repertoire showed no changes in Vγ1, Vγ4, Vγ7 or Vδ1 subsets from controls at post-tumor day 10–12 or at end stage except for an end-stage increase in the Vδ4 population. Approximately 12% of γδ T cells produced IFN-γ. IL-17 and IL-4 producing γδ T cells were not detected. Tumor progression was the same in TCRδ-/- C57BL/6 mice as that observed in WT mice, suggesting that γδ T cells exerted neither a regulatory nor a sustainable cytotoxic effect on the tumor. WT mice that received an intracranial injection of γδ T cells 15m following tumor placement showed evidence of local tumor growth inhibition but this was insufficient to confer a survival advantage over untreated controls. Taken together, our findings suggest that an early nonspecific proliferation of γδ T cells followed by their depletion occurs in mice implanted with syngeneic GL261 gliomas. The mechanism by which γδ T cell expansion occurs remains a subject for further investigation of the mechanisms responsible for this immune response in the setting of high-grade glioma.  相似文献   

9.
It is known that obese adipose tissues are hypoxic and express hypoxia-inducible factor (HIF)-1α. Although some studies have shown that the expression of HIF-1α in adipocytes induces glucose intolerance, the mechanisms are still not clear. In this study, we examined its effects on the development of type 2 diabetes by using adipocyte-specific HIF-1α knockout (ahKO) mice. ahKO mice showed improved glucose tolerance compared with wild type (WT) mice. Macrophage infiltration and mRNA levels of monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor α (TNFα) were decreased in the epididymal adipose tissues of high fat diet induced obese ahKO mice. The results indicated that the obesity-induced adipose tissue inflammation was suppressed in ahKO mice. In addition, in the ahKO mice, serum insulin levels were increased under the free-feeding but not the fasting condition, indicating that postprandial insulin secretion was enhanced. Serum glucagon-like peptide-1 (GLP-1) levels were also increased in the ahKO mice. Interestingly, adiponectin, whose serum levels were increased in the obese ahKO mice compared with the obese WT mice, stimulated GLP-1 secretion from cultured intestinal L cells. Therefore, insulin secretion may have been enhanced through the adiponectin-GLP-1 pathway in the ahKO mice. Our results suggest that the deletion of HIF-1α in adipocytes improves glucose tolerance by enhancing insulin secretion through the GLP-1 pathway and by reducing macrophage infiltration and inflammation in adipose tissue.  相似文献   

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Chemoresistance and migration represent major obstacles in the therapy of non‐small‐cell lung cancer (NSCLC), which accounts for approximately 85% of lung cancer patients in clinic. In the present study, we report that the compound C1632 is preferentially distributed in the lung after oral administration in vivo with high bioavailability and limited inhibitory effects on CYP450 isoenzymes. We found that C1632 could simultaneously inhibit the expression of LIN28 and block FGFR1 signalling transduction in NSCLC A549 and A549R cells, resulting in significant decreases in the phosphorylation of focal adhesion kinase and the expression of matrix metalloproteinase‐9. Consequently, C1632 effectively inhibited the migration and invasion of A549 and A549R cells. Meanwhile, C1632 significantly suppressed the cell viability and the colony formation of A549 and A549R cells by inhibiting DNA replication and inducing G0/G1 cell cycle arrest. Interestingly, compared with A549 cells, C1632 possesses the same or even better anti‐migration and anti‐proliferation effects on A549R cells, regardless of drug resistance. In addition, C1632 also displayed the capacity to inhibit the growth of A549R xenograft tumours in mice. Altogether, these findings reveal the potential of C1632 as a promising anti‐NSCLC agent, especially for chemotherapy‐resistant NSCLC treatment.  相似文献   

12.
Lung cancer remains the leading cause of cancer deaths in the United States and the rest of the world. The advent of molecularly directed therapies holds promise for improvement in therapeutic efficacy. Cytosolic phospholipase A2 (cPLA2) is associated with tumor progression and radioresistance in mouse tumor models. Utilizing the cPLA2 specific inhibitor PLA-695, we determined if cPLA2 inhibition radiosensitizes non small cell lung cancer (NSCLC) cells and tumors. Treatment with PLA-695 attenuated radiation induced increases of phospho-ERK and phospho-Akt in endothelial cells. NSCLC cells (LLC and A549) co-cultured with endothelial cells (bEND3 and HUVEC) and pre-treated with PLA-695 showed radiosensitization. PLA-695 in combination with irradiation (IR) significantly reduced migration and proliferation in endothelial cells (HUVEC & bEND3) and induced cell death and attenuated invasion by tumor cells (LLC &A549). In a heterotopic tumor model, the combination of PLA-695 and radiation delayed growth in both LLC and A549 tumors. LLC and A549 tumors treated with a combination of PLA-695 and radiation displayed reduced tumor vasculature. In a dorsal skin fold model of LLC tumors, inhibition of cPLA2 in combination with radiation led to enhanced destruction of tumor blood vessels. The anti-angiogenic effects of PLA-695 and its enhancement of the efficacy of radiotherapy in mouse models of NSCLC suggest that clinical trials for its capacity to improve radiotherapy outcomes are warranted.  相似文献   

13.
There were studies investigating the effects of broadband infrared radiation (IR) on cancer cell, while the influences of middle-infrared radiation (MIR) are still unknown. In this study, a MIR emitter with emission wavelength band in the 3–5 µm region was developed to irradiate A549 lung adenocarcinoma cells. It was found that MIR exposure inhibited cell proliferation and induced morphological changes by altering the cellular distribution of cytoskeletal components. Using quantitative PCR, we found that MIR promoted the expression levels of ATM (ataxia telangiectasia mutated), ATR (ataxia-telangiectasia and Rad3-related and Rad3-related), TP53 (tumor protein p53), p21 (CDKN1A, cyclin-dependent kinase inhibitor 1A) and GADD45 (growth arrest and DNA-damage inducible), but decreased the expression levels of cyclin B coding genes, CCNB1 and CCNB2, as well as CDK1 (Cyclin-dependent kinase 1). The reduction of protein expression levels of CDC25C, cyclin B1 and the phosphorylation of CDK1 at Thr-161 altogether suggest G2/M arrest occurred in A549 cells by MIR. DNA repair foci formation of DNA double-strand breaks (DSB) marker γ-H2AX and sensor 53BP1 was induced by MIR treatment, it implies the MIR induced G2/M cell cycle arrest resulted from DSB. This study illustrates a potential role for the use of MIR in lung cancer therapy by initiating DSB and blocking cell cycle progression.  相似文献   

14.
Alzheimer''s disease (AD) is characterized by neuronal loss and accumulation of β-amyloid-protein (Aβ) in the brain parenchyma. Sleep impairment is associated with AD and affects about 25–40% of patients in the mild-to-moderate stages of the disease. Sleep deprivation leads to increased Aβ production; however, its mechanism remains largely unknown. We hypothesized that the increase in core body temperature induced by sleep deprivation may promote Aβ production. Here, we report temperature-dependent regulation of Aβ production. We found that an increase in temperature, from 37 °C to 39 °C, significantly increased Aβ production in amyloid precursor protein-overexpressing cells. We also found that high temperature (39 °C) significantly increased the expression levels of heat shock protein 90 (Hsp90) and the C-terminal fragment of presenilin 1 (PS1-CTF) and promoted γ-secretase complex formation. Interestingly, Hsp90 was associated with the components of the premature γ-secretase complex, anterior pharynx-defective-1 (APH-1), and nicastrin (NCT) but was not associated with PS1-CTF or presenilin enhancer-2. Hsp90 knockdown abolished the increased level of Aβ production and the increased formation of the γ-secretase complex at high temperature in culture. Furthermore, with in vivo experiments, we observed increases in the levels of Hsp90, PS1-CTF, NCT, and the γ-secretase complex in the cortex of mice housed at higher room temperature (30 °C) compared with those housed at standard room temperature (23 °C). Our results suggest that high temperature regulates Aβ production by modulating γ-secretase complex formation through the binding of Hsp90 to NCT/APH-1.  相似文献   

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Transforming growth factor-β1 (TGF-β1) and -β2 are correlated with poorer prognosis in gastric cancer (GC), which act in both tumor and immune cells. However, their expressions in precancer and tumor-cell interactions with peripheral blood mononuclear cells (PBMCs) remain unclear. Protein levels of TGF-β1 and -β2 were analyzed by immunohistochemistry and corresponding mRNA levels were determined by quantitative real-time polymerase chain reaction in 93 surgical and biopsy specimens. Serum TGF-β concentration was detected by enzyme-linked immunosorbent assays. AGS and MKN45 cell lines were directly or indirectly cocultured with PBMCs in vitro. TGF-β and Smad molecules were detected after cocultures and the growths of GC cells and PBMCs were assessed by cell proliferation assay. The results showed positive staining for TGF-β1 was detected in 20% of control samples, 52.3% of precancer, 59.1% of early GC and 66.7% of advanced GC samples, correlated with lesion progression (χ2 = 9.487, P = 0.002). All tissues were positive for TGF-β2. TGF-β1 mRNA levels were increased in advanced cancers, while TGF-β2 increased earlier. TGF-β1 mRNA levels were higher in tumor than in peritumor, which positively correlated with Smad2 and Smad7. Serum TGF-β levels were significantly higher in patients with early and advanced cancers compared to controls (TGF-β1∶50.08±4.38 and 45.76±5.00 vs. 27.78±6.11 ng/mL; TGF-β2∶133.61±21.90 and 111.34±15.76 vs. 59.41±15.42 ng/mL, both P<0.05). The levels of TGF-β1 mRNA and cytokine secretion were higher in GC cells after direct coculture compared to indirect culture. TGF-β1 was decreased and TGF-β2 was increased in PBMCs after cocultures. Moreover, TGF-β1 inhibited the viability of PBMCs but not cancer cells. Collectively, neoplastic transformation may be an early event involving the increase of TGF-β1 in the general and local environment. TGF-β1 production is promoted by the direct interaction between GC cells and PBMCs, which might facilitate cancer development.  相似文献   

17.
Melanoma is one of the most aggressive and life‐threatening skin cancers, and in this research, we aimed to explore the functional role of circular RNA VANGL1 (circVANGL1) in melanoma progression. The expression levels of circVANGL1 were observed to be significantly increased in clinical melanoma tissues and cell lines. Moreover, circVANGL1 knockdown suppressed, while circVANGL1 overexpression promoted the proliferation, migration and invasion abilities of melanoma cells. Further investigations confirmed the direct binding relation between circVANGL1 and miR‐150‐5p in melanoma, and restoration of miR‐150‐5p blocked the effects of circVANGL1 overexpression in melanoma cells. We further found that circVANGL1 was up‐regulated by TGF‐β treatment, and the enhanced EMT of TGF‐β‐treated melanoma cells was blocked by circVANGL1 knockdown. In conclusion, these results indicated that circVANGL1 might serve as a promising therapeutic target for melanoma.  相似文献   

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Mutations of oncogenes and tumor suppressor genes which activate mTOR through several downstream signaling pathways are common to cancer. Activation of mTOR when combined with inhibition of cell cycle progression or DNA replication stress has previously been shown to promote cell senescence. In the present study, we examined the conditions under which human non-small cell lung carcinoma A549 cells can undergo senescence when treated with the DNA alkylating agent mitomycin C (MMC). While exposure of A549 cells to 0.1 or 0.5 µg/ml of MMC led to their arrest in S phase of the cell cycle and subsequent apoptosis, exposure to 0.01 or 0.02 µg/ml for 6 d resulted in induction of cell senescence and near total (0.01 µg/ml) or total (0.02 µg/ml) elimination of their reproductive potential. During exposure to these low concentrations of MMC, the cells demonstrated evidence of DNA replication stress manifested by expression of γH2AX, p21WAF1 and a very low level of EdU incorporation into DNA. The data are consistent with the notion that enduring DNA replication stress in cells known to have activated oncogenes leads to their senescence. It is reasonable to expect that tumors having constitutive activation of oncogenes triggering mTOR signaling may be particularly predisposed to undergoing senescence following prolonged treatment with low doses of DNA damaging drugs.  相似文献   

20.
Hypercholesterolemia impairs the quantity and function of endothelial progenitor cell. We hypothesized that glycogen synthase kinase 3β activity is involved in regulating biological function of endothelial progenitor cells in hypercholesterolemia microenvironment. For study, endothelial progenitor cells derived from apolipoprotein E-deficient mice fed with high-fat diet were used. Glycogen synthase kinase 3β activity was interfered with glycogen synthase kinase 3β inhibitor lithium chloride or transduced with replication defective adenovirus vector expressing catalytically inactive glycogen synthase kinase 3β (GSK3β-KM). Functions of endothelial progenitor cells, proliferation, migration, secretion and network formation of endothelial progenitor cells were assessed in vitro. The expression of phospho-glycogen synthase kinase 3β, β-catenin and cyclinD1 in endothelial progenitor cells was detected by Western blot. The in vivo function re-endothelialization and vasodilation were also analyzed by artery injury model transplanted with glycogen synthase kinase 3β-inhibited endothelial progenitor cells. We demonstrated that while the proliferation, migration, network formation as well as VEGF and NO secretion were impaired in apolipoprotein E-deficient endothelial progenitor cells, glycogen synthase kinase 3β inhibition significantly improved all these functions. Apolipoprotein E-deficient endothelial progenitor cells showed decreased phospho-glycogen synthase kinase 3β, β-catenin and cyclinD1 expression, whereas these signals were enhanced by glycogen synthase kinase 3β inhibition and accompanied with β-catenin nuclear translocation. Our in vivo model showed that glycogen synthase kinase 3β inhibition remarkably increased re-endothelial and vasodilation. Taken together, our data suggest that inhibition of glycogen synthase kinase 3β is associated with endothelial progenitor cell biological functions both in vitro and in vivo. It might be an important interference target in hypercholesterolemia microenvironment.  相似文献   

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