980 resultados para Colonic neoplasms


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Macrophage migration inhibitory factor (MIF), which inhibits apoptosis and promotes angiogenesis, is expressed in cancers suppressing immune surveillance. Its biological role in human glioblastoma is, however, only poorly understood. We examined in-vivo expression of MIF in 166 gliomas and 23 normal control brains by immunohistochemistry. MIF immunoreactivity was enhanced in neoplastic astrocytes in WHO grade II glioma and increased significantly in higher tumour grades (III-IV). MIF expression was further assessed in 12 glioma cell lines in vitro. Quantitative RT-PCR showed that MIF mRNA expression was elevated up to 800-fold in malignant glioma cells compared with normal brain. This translated into high protein levels as assessed by immunoblotting of total cell lysates and by ELISA-based measurement of secreted MIF. Wild-type p53-retaining glioma cell lines expressed higher levels of MIF, which may be connected with the previously described role of MIF as a negative regulator of wild-type p53 signalling in tumour cells. Stable knockdown of MIF by shRNA in glioma cells significantly increased tumour cell susceptibility towards NK cell-mediated cytotoxicity. Furthermore, supernatant from mock-transfected cells, but not from MIF knockdown cells, induced downregulation of the activating immune receptor NKG2D on NK and CD8+ T cells. We thus propose that human glioma cell-derived MIF contributes to the immune escape of malignant gliomas by counteracting NK and cytotoxic T-cell-mediated tumour immune surveillance. Considering its further cell-intrinsic and extrinsic tumour-promoting effects and the availability of small molecule inhibitors, MIF seems to be a promising candidate for future glioma therapy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Malignant tumors metabolize glucose to lactate even in the presence of oxygen (aerobic glycolysis). The metabolic switch from oxidative glycolysis to non-oxidative fermentation of glucose and proteins performed by the tumor cells seems to be associated with TKTL1 and pAkt overexpression. Therefore the aim of the present study was to investigate the expression of TKTL1 and pAkt in human specimens of endometrial cancer as compared to benign endometrium. Additionally, expression of the glucose transporter GLUT1 was also investigated as aerobic glycolysis is associated with an increased need for glucose.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Growth and differentiation factor (GDF)-15 is a member of the transforming growth factor (TGF)-beta family. GDF-15 is necessary for the maintenance of pregnancy but has also been linked to other physiologic and pathologic conditions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Although trastuzumab (Herceptin) has substantially improved the overall survival of patients with mammary carcinomas, even initially well-responding tumors often become resistant. Because natural killer (NK) cell-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) is thought to contribute to the therapeutic effects of trastuzumab, we have established a cell culture system to select for ADCC-resistant SK-OV-3 ovarian cancer and MCF7 mammary carcinoma cells. Ovarian cancer cells down-regulated HER2 expression, resulting in a more resistant phenotype. MCF7 breast cancer cells, however, failed to develop resistance in vitro. Instead, treatment with trastuzumab and polyclonal NK cells resulted in the preferential survival of individual sphere-forming cells that displayed a CD44(high)CD24(low) "cancer stem cell-like" phenotype and expressed significantly less HER2 compared with non-stem cells. Likewise, the CD44(high)CD24(low) population was also found to be more immunoresistant in SK-BR3, MDA-MB231, and BT474 breast cancer cell lines. When immunoselected MCF7 cells were then re-expanded, they mostly lost the observed phenotype to regenerate a tumor cell culture that displayed the initial HER2 surface expression and ADCC-susceptibility, but was enriched in CD44(high)CD24(low) cancer stem cells. This translated into increased clonogenicity in vitro and tumorigenicity in vivo. Thus, we provide evidence that the induction of ADCC by trastuzumab and NK cells may spare the actual tumor-initiating cells, which could explain clinical relapse and progress. Moreover, our observation that the "relapsed" in vitro cultures show practically identical HER2 surface expression and susceptibility toward ADCC suggests that the administration of trastuzumab beyond relapse might be considered, especially when combined with an immune-stimulatory treatment that targets the escape variants.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Cathelicidin is an antimicrobial peptide (AMP) and signaling molecule in innate immunity and a direct target of 1,25-dihydroxyvitamin D3 (1,25D3) in primary human keratinocytes (NHEK). The expression of cathelicidin is dysregulated in various skin diseases and its regulation differs depending on the epithelial cell type. The secondary bile acid lithocholic acid (LCA) is a ligand of the vitamin D receptor (VDR) and can carry out in vivo functions of vitamin D3. Therefore we analyzed cathelicidin mRNA- and peptide expression levels in NHEK and colonic epithelial cells (Caco-2) after stimulation with LCA. We found increased expression of cathelicidin mRNA and peptide in NHEK, in Caco-2 colon cells no effect was observed after LCA stimulation. The VDR as well as MEK-ERK signaled the upregulation of cathelicidin in NHEK induced by LCA. Collectively, our data indicate that cathelicidin induction upon LCA treatment differs in keratinocytes and colonic epithelial cells. Based on these observations LCA-like molecules targeting cathelicidin could be designed for the treatment of cutaneous diseases that are characterized by disturbed cathelicidin expression.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Perifosine is an orally active alkylphospholipid analog, which has shown anti-tumor activity in a variety of cancers by inhibition of AKT phosphorylation. The objective of the current study was to evaluate its efficacy in in vitro models of human endometrial cancer.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The proinflammatory cytokine macrophage migration inhibitory factor (MIF) stimulates tumor cell proliferation, migration, and metastasis; promotes tumor angiogenesis; suppresses p53-mediated apoptosis; and inhibits antitumor immunity by largely unknown mechanisms. We here describe an overexpression of MIF in ovarian cancer that correlates with malignancy and the presence of ascites. Functionally, we find that MIF may contribute to the immune escape of ovarian carcinoma by transcriptionally down-regulating NKG2D in vitro and in vivo which impairs NK cell cytotoxicity toward tumor cells. Together with the additional tumorigenic properties of MIF, this finding provides a rationale for novel small-molecule inhibitors of MIF to be used for the treatment of MIF-secreting cancers.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

DietCompLyf is a multi-centre prospective study designed to investigate associations between phytoestrogens - naturally occurring plant compounds with oestrogenic properties - and other diet and lifestyle factors with breast cancer recurrence and survival. 3159 women with grades I-III breast cancer were recruited 9-15 months post-diagnosis from 56 UK hospitals. Detailed information on clinico-pathological, diet, lifestyle and quality of life is collected annually up to 5 years. Biological samples have also been collected as a resource for subsequent evaluation. The characteristics of the patients and associations between pre-diagnosis intake of phytoestrogens (isoflavones and lignans; assessed using the EPIC-Norfolk UK 130 question food frequency questionnaire) and breast cancer (i) risk factors and (ii) prognostic factors are described for 1797 women who had complete data for all covariates and phytoestrogens of interest. Isoflavone intakes were higher in the patients who were younger at diagnosis, in the non-smokers, those who had breast-fed and those who took supplements. Lignan intakes were higher in patients with a higher age at diagnosis, in ex-smokers, those who had breast-fed, who took supplements, had a lower BMI at diagnosis, lower age at menarche and were nulliparous. No significant associations between pre-diagnosis phytoestrogen intake and factors associated with improved breast cancer prognosis were observed. The potential for further exploration of the relationship between phytoestrogens and breast cancer recurrence and survival, and for the establishment of evidence to improve dietary and lifestyle advice offered to patients following breast cancer diagnosis using DietCompLyf data is discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Nutritional biomarkers-biochemical, functional, or clinical indices of nutrient intake, status, or functional effects--are needed to support evidence-based clinical guidance and effective health programs and policies related to food, nutrition, and health. Such indices can reveal information about biological or physiological responses to dietary behavior or pathogenic processes, and can be used to monitor responses to therapeutic interventions and to provide information on interindividual differences in response to diet and nutrition. Many nutritional biomarkers are available; yet there has been no formal mechanism to establish consensus regarding the optimal biomarkers for particular nutrients and applications.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

High-risk HPVs were detected in both breast cancer tissues and cervical cells from 56 breast cancer patients. The results suggested that HPV infection did not coexist in breast and cervical tissues. HPV infection of the breast cancer tissue is more likely to happen in patients without cervical infection.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The myeloproliferative neoplasms, are characterised by overproduction of myeloid cells. Chronic myeloid leukaemia, polycythaemia vera, essential thrombocythaemia, myelofibrosis and the very rare disorders chronic neutrophilic leukaemia, chronic eosinophilic leukaemia not otherwise specified and mastocytosis are all included in the group. Incidence and prevalence rates reported in the worldwide literature are presented in this review. Survival data on each condition is described. Information on the aetiology of the disorders is discussed including body mass index, diet, smoking and alcohol, allergies, associated medical conditions, occupation and environmental exposures with focus on recent new studies. The aetiology of the myeloproliferative neoplasms remains unknown, and this review of the current state of knowledge highlights the need for further comprehensive research.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

OBJECTIVE: Cancer survivors (CSs) are at risk of developing late effects (LEs) associated with the disease and its treatment. This paper compares the health status, care needs and use of health services by CSs with LEs and CSs without LEs.

METHODS: Cancer survivors (n = 613) were identified via the Northern Ireland Cancer Registry and invited to participate in a postal survey that was administered by their general practitioner. The survey assessed self-reported LEs, health status, health service use and unmet care needs. A total of 289 (47%) CSs responded to the survey, and 93% of respondents completed a LEs scale.

RESULTS: Forty-one per cent (111/269) of CSs reported LEs. Survivors without LEs and survivors with LEs were comparable in terms of age and gender. The LEs group reported a significantly greater number of co-morbidities, lower physical health and mental health scores, greater overall health service use and more unmet needs. Unadjusted logistic regression analysis found that cancer site, time since diagnosis and treatment were significantly associated with reporting of LEs. CSs who received combination therapies compared with CSs who received single treatments were over two and a half times more likely to report LEs (OR = 2.63, 95% CI = 1.32-5.25) after controlling for all other variables.

CONCLUSIONS: The CS population with LEs comprises a particularly vulnerable group of survivors who have multiple health care problems and needs and who require tailored care plans that take account of LEs and their impact on health-related quality of life.