241 research outputs found

    In vitro effect of hyperthermic Ag and Au Fe₃O₄ nanoparticles in cancer cells

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    PURPOSE: To investigate the anti-cancer efficacy of hyperthermic Ag and Au Fe3O4 core nanoparticles via cytotoxicity study (MTT assay) and the underlying molecular mechanism of action (changes in gene expression via quantitive real time PCR (qRT-PCR). METHODS: HEK293, HCT116, 4T1 and HUH7 human cell lines and 4T1 musculus mammary gland cell line were incubated with Fe3O4 core Ag(Au) shell nanoparticles (NPs) prior to a hyperthermia session. MTT assay was performed to estimate the cytotoxic effects of these NPs. RNA extraction and cDNA synthesis followed so as to quantify mRNA fold change of hsp-70, p53, bcl-2 and casp-3 via qRT-PCR. RESULTS: Fe3O4 core Au shell (concentrations of 400 and 600μg/mL) produced the greatest reduction of viability on HCT116 and 4T1 cells while Fe3O4 core Ag shell (200, 400 and 600μg/mL) reduce viability on HUH7 cells. Hsp-70, p53 and casp-3 were up-regulated while bcl-2 was downregulated in most cases. CONCLUSIONS: Fe3O4 core Ag (Au) shell induced apoptosis on cancer cells (HCT116 and HUH7) via the p53/bcl-2/casp-3 pathway. 4T1 cells also underwent apoptosis via a p53-independent pathway

    Tissue detection of natural killer cells in colorectal adenocarcinoma

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    BACKGROUND: Natural killer (NK) cells represent a first line of defence against a developing cancer; however, their exact role in colorectal cancer remains undetermined. The aim of the present study was to evaluate the expression of CD16 and CD57 [immunohistochemical markers of natural NK cells] in colorectal adenocarcinoma. METHODS: Presence of NK cells was investigated in 82 colorectal adenocarcinomas. Immunohistochemical analysis was performed, using 2 monoclonal antibodies (anti-Fc Gamma Receptor II, CD16 and an equivalent to Leu-7, specific for CD-57). The number of immunopositive cells (%) was evaluated by image analysis. The cases were characterized according to: patient gender and age, tumor location, size, grade, bowel wall invasion, lymph node metastases and Dukes' stage. RESULTS: NK cells were detected in 79/82 cases at the primary tumor site, 27/33 metastatic lymph nodes and 3/4 hepatic metastases; they were detected in levels similar to those reported in the literature, but their presence was not correlated to the clinical or pathological characteristics of the series, except for a negative association with the patients' age (p = 0.031). CONCLUSIONS: Our data do not support an association of NK cell tissue presence with clinical or pathological variables of colorectal adenocarcinoma, except for a negative association with the patients' age; this might possibly be attributed to decreased adhesion molecule expression in older ages

    The dynamic clustering of insulin receptor underlies its signaling and is disrupted in insulin resistance

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    Insulin receptor (IR) signaling is central to normal metabolic control and is dysregulated in metabolic diseases such as type 2 diabetes. We report here that IR is incorporated into dynamic clusters at the plasma membrane, in the cytoplasm and in the nucleus of human hepatocytes and adipocytes. Insulin stimulation promotes further incorporation of IR into these dynamic clusters in insulin-sensitive cells but not in insulin-resistant cells, where both IR accumulation and dynamic behavior are reduced. Treatment of insulin-resistant cells with metformin, a first-line drug used to treat type 2 diabetes, can rescue IR accumulation and the dynamic behavior of these clusters. This rescue is associated with metformin’s role in reducing reactive oxygen species that interfere with normal dynamics. These results indicate that changes in the physico-mechanical features of IR clusters contribute to insulin resistance and have implications for improved therapeutic approaches

    HER 2/neu protein expression in colorectal cancer

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    BACKGROUND: Conflicting data exist about the prevalence of HER-2/neu overexpression in colorectal cancer ranging from 0 to 83 %. In our study we tried to clarify the extent of expression and its relationship to clinicopathological parameters. METHODS: This study involved 77 specimens of malignant colorectal cancer lesions of surgically resected patients. HER-2/neu immunohistochemistry was performed using the Hercep-Test Kit. RESULTS: Out of 77 specimens, 56 were Her-2/neu negative (70%), 20 (26%) showed a barely immunostaining (1+), only 1 (1%) was moderately (2+) and 2 (3%) were strongly positive (3+). Her-2/neu staining (moderately and strongly positive) was only detected in primary tumours of patients with confirmed metastases. No relationship was found between membranous HER-2 expression and patients' gender or differentiation. The median survival time of patients with positive HER-2/neu immunostaining was 21 versus 39 months in patients without HER-2/neu expression (p = 0.088). CONCLUSION: The c-erbB protein expression was observed in colorectal cancer but rarely in the therapeutic range (2+ and 3+). There was no significant association with tumour grade, gender, localization of the primary tumour or survival. These data indicate that c-erbB-2 is unlikely to play a major role in the therapeutic management of colorectal cancer

    Vessel co-option mediates resistance to anti-angiogenic therapy in liver metastases

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    The efficacy of angiogenesis inhibitors in cancer is limited by resistance mechanisms that are poorly understood. Notably, instead of through the induction of angiogenesis, tumor vascularization can occur through the nonangiogenic mechanism of vessel co-option. Here we show that vessel co-option is associated with a poor response to the anti-angiogenic agent bevacizumab in patients with colorectal cancer liver metastases. Moreover, we find that vessel co-option is also prevalent in human breast cancer liver metastases, a setting in which results with anti-angiogenic therapy have been disappointing. In preclinical mechanistic studies, we found that cancer cell motility mediated by the actin-related protein 2/3 complex (Arp2/3) is required for vessel co-option in liver metastases in vivo and that, in this setting, combined inhibition of angiogenesis and vessel co-option is more effective than the inhibition of angiogenesis alone. Vessel co-option is therefore a clinically relevant mechanism of resistance to anti-angiogenic therapy and combined inhibition of angiogenesis and vessel co-option might be a warranted therapeutic strategy

    The Translation Factor eIF6 Is a Notch-Dependent Regulator of Cell Migration and Invasion

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    A growing body of evidence indicates that protein factors controlling translation play an important role in tumorigenesis. The protein known as eIF6 is a ribosome anti-association factor that has been implicated in translational initiation and in ribosome synthesis. Over-expression of eIF6 is observed in many natural tumours, and causes developmental and differentiation defects in certain animal models. Here we show that the transcription of the gene encoding eIF6 is modulated by the receptor Notch-1, a protein involved in embryonic development and cell differentiation, as well as in many neoplasms. Inhibition of Notch-1 signalling by γ-secretase inhibitors slowed down cell-cycle progression and reduced the amount of eIF6 in lymphoblastoid and ovarian cancer cell lines. Cultured ovarian cancer cell lines engineered to stably over-expressing eIF6 did not show significant changes in proliferation rate, but displayed an enhanced motility and invasive capacity. Inhibition of Notch-1 signalling in the cells over-expressing eIF6 was effective in slowing down the cell cycle, but did not reduce cell migration and invasion. On the whole, the results suggest that eIF6 is one of the downstream effectors of Notch-1 in the pathway that controls cell motility and invasiveness

    A pathological fracture and a solitary mass in the right clavicle: an unusual first presentation of HCC and the role of immunohistochemistry

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    <p>Absrtract</p> <p>Hepatocellular carcinoma (HCC) is an aggressive malignant tumor that occurs throughout the world. Îœetastases from hepatocellular carcinoma (HCC) were generally considered to be rare in the past, because the carcinoma had an aggressive clinical course. In our era, has been reported that extra-hepatic metastases occur in 13.5%-41.7% of HCC patients and this is considered as terminal-stage cancer. The prognosis for patients at this stage continues to be poor due to limited effective treatment. The common sites of extrahepatic metastases in patients with HCC are the lungs, regional lymph nodes, kidney, bone marrow and adrenals. We present here an extremely infrequent case of a patient, without known liver disease, in which the presenting symptom was a pathological-in retrospect-fracture of his right clavicle which wasn't properly evaluated, until he presented a bulky mass in the region 6 months later. For our patient, the added diagnostic difficulty alongside the unknown liver disease, has been that the clavicular metastases was the first presentation of any metastatic disease, rather than the more common sites of HCC spread to adjacent lung or lymph nodes.</p

    Decreased Hsp90 expression in infiltrative lobular carcinoma: an immunohistochemical study

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    Background: Elevated Hsp90 expression has been documented in breast ductal carcinomas, whereas decreased Hsp90 expression has been reported in precursor lobular lesions. This study aims to assess Hsp90 expression in infiltrative lobular carcinomas of the breast. Methods: Tissue specimens were taken from 32 patients with infiltrative lobular carcinoma. Immunohistochemical assessment of Hsp90 was performed both in the lesion and the adjacent normal breast ducts and lobules; the latter serving as control. Concerning Hsp90 assessment: i) the percentage of positive cells and ii) the intensity were separately analyzed. Subsequently, the Allred score was adopted and calculated. The intensity was treated as a
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