471 research outputs found
Cure of mammary carcinomas in Her-2 transgenic mice through sequential stimulation of innate (neoadjuvant interleukin-12) and adaptive (DNA vaccine electroporation) immunity.
Purpose: Whereas neoadjuvant therapy is emerging as
a treatment option in early primary breast cancer, no data
are available on the use of antiangiogenic and immunomodulatory
agents in a neoadjuvant setting. In a model of
Her-2 spontaneous mammary cancer, we investigated the
efficacy of neoadjuvant interleukin 12 (IL-12) followed by
‘‘immune-surgery’’ of the residual tumor.
Experimental Design: Female BALB/c mice transgenic
for the rat Her-2 oncogene inexorably develop invasive
carcinomas in all their mammary glands by the 23rd week of
age. Mice with multifocal in situ carcinomas received four
weekly i.p. injections of 100 ng IL-12 followed by a 3-week
rest. This course was given four times. A few mice
additionally received DNA plasmids encoding portions of
the Her-2 receptor electroporated through transcutaneous
electric pulses.
Results: The protection elicited by IL-12 in combination
with two DNA vaccine electroporations kept 63% of
mice tumor-free. Complete protection of all 1-year-old mice
was achieved when IL-12-treated mice received four
vaccine electroporations. Pathologic findings, in vitro tests,
and the results from immunization of both IFN-; andimmunoglobulin gene knockout transgenic mice and of
adoptive transfer experiments all show that IL-12 augments
the B- and T-cell response elicited by vaccination and
slightly decreases the number of regulatory T cells. In
addition, IL-12 strongly inhibits tumor angiogenesis.
Conclusions: In Her-2 transgenic mice, IL-12 impairs
tumor progression and triggers innate immunity so markedly
that DNA vaccination becomes effective at late points in time
when it is ineffective on its own
High Methanol Oxidation Activity of Well-Dispersed Pt Nanoparticles on Carbon Nanotubes Using Nitrogen Doping
Pt nanoparticles (NPs) with the average size of 3.14 nm well dispersed on N-doped carbon nanotubes (CNTs) without any pretreatment have been demonstrated. Structural properties show the characteristic N bonding within CNTs, which provide the good support for uniform distribution of Pt NPs. In electrochemical characteristics, N-doped CNTs covered with Pt NPs show superior current density due to the fact that the so-called N incorporation could give rise to the formation of preferential sites within CNTs accompanied by the low interfacial energy for immobilizing Pt NPs. Therefore, the substantially enhanced methanol oxidation activity performed by N-incorporation technique is highly promising in energy-generation applications
Preparation and thermal conductivity of CuO nanofluid via a wet chemical method
In this article, a wet chemical method was developed to prepare stable CuO nanofluids. The influences of synthesis parameters, such as kinds and amounts of copper salts, reaction time, were studied. The thermal conductivities of CuO nanofluids were also investigated. The results showed that different copper salts resulted in different particle morphology. The concentration of copper acetate and reaction time affected the size and shape of clusters of primary nanoparticles. Nanofluids with different microstructures could be obtained by changing the synthesis parameters. The thermal conductivities of CuO nanofluids increased with the increase of particle loading
Breast cancer incidence highest in the range of one species of house mouse, Mus domesticus
Incidence of human breast cancer (HBC) varies geographically, but to date no environmental factor has explained this variation. Previously, we reported a 44% reduction in the incidence of breast cancer in women fully immunosuppressed following organ transplantation (Stewart et al (1995) Lancet346: 796–798). In mice infected with the mouse mammary tumour virus (MMTV), immunosuppression also reduces the incidence of mammary tumours. DNA with 95% identity to MMTV is detected in 40% of human breast tumours (Wang et al (1995) Cancer Res55: 5173–5179). These findings led us to ask whether the incidence of HBC could be correlated with the natural ranges of different species of wild mice. We found that the highest incidence of HBC worldwide occurs in lands where Mus domesticus is thse resident native or introduced species of house mouse. Given the similar responses of humans and mice to immunosuppression, the near identity between human and mouse MTV DNA sequences, and the close association between HBC incidence and mouse ranges, we propose that humans acquire MMTV from mice. This zoonotic theory for a mouse-viral cause of HBC allows testable predictions and has potential importance in prevention. © 2000 Cancer Research Campaig
ErbB2 and bone sialoprotein as markers for metastatic osteosarcoma cells
Osteosarcoma is the most common malignant bone neoplasia occurring in young patients in the first two decades of life, and represents 20% of all primitive malignant bone tumours. At present, treatment of metastatic osteosarcoma is unsatisfactory. High-dose chemotherapy followed by CD34+ leukapheresis rescue may improve these poor results. Neoplastic cells contaminating the apheresis may, however, contribute to relapse. To identify markers suitable for detecting osteosarcoma cells in aphereses we analysed the expression of bone-specific genes (Bone Sialoprotein (BSP) and Osteocalcin) and oncogenes (Met and ErbB2) in 22 patients with metastatic osteosarcoma and six healthy stem cell donors. The expression of these genes in aphereses of patients affected by metastatic osteosarcoma was assessed by RT–PCR and Southern blot analysis. Met and Osteocalcin proved to be not useful markers since they are positive in aphereses of both patients with metastatic osteosarcoma and healthy stem cell donors. On the contrary, BSP was expressed at significant levels in 85% of patients. Moreover, 18% of patients showed a strong and significantly positive (seven to 16 times higher than healthy stem cell donors) ErbB2 expression. In all positive cases, neoplastic tissue also expressed ErbB2. Our data show that ErbB2 can be a useful marker for tumour contamination in aphereses of patients affected by ErbB2-expressing osteosarcomas and that analysis of Bone Sialoprotein expression can be an alternative useful marker
Predicting Anatomical Therapeutic Chemical (ATC) Classification of Drugs by Integrating Chemical-Chemical Interactions and Similarities
The Anatomical Therapeutic Chemical (ATC) classification system, recommended by the World Health Organization, categories drugs into different classes according to their therapeutic and chemical characteristics. For a set of query compounds, how can we identify which ATC-class (or classes) they belong to? It is an important and challenging problem because the information thus obtained would be quite useful for drug development and utilization. By hybridizing the informations of chemical-chemical interactions and chemical-chemical similarities, a novel method was developed for such purpose. It was observed by the jackknife test on a benchmark dataset of 3,883 drug compounds that the overall success rate achieved by the prediction method was about 73% in identifying the drugs among the following 14 main ATC-classes: (1) alimentary tract and metabolism; (2) blood and blood forming organs; (3) cardiovascular system; (4) dermatologicals; (5) genitourinary system and sex hormones; (6) systemic hormonal preparations, excluding sex hormones and insulins; (7) anti-infectives for systemic use; (8) antineoplastic and immunomodulating agents; (9) musculoskeletal system; (10) nervous system; (11) antiparasitic products, insecticides and repellents; (12) respiratory system; (13) sensory organs; (14) various. Such a success rate is substantially higher than 7% by the random guess. It has not escaped our notice that the current method can be straightforwardly extended to identify the drugs for their 2nd-level, 3rd-level, 4th-level, and 5th-level ATC-classifications once the statistically significant benchmark data are available for these lower levels
Downregulation of FIP200 Induces Apoptosis of Glioblastoma Cells and Microvascular Endothelial Cells by Enhancing Pyk2 Activity
The expression of focal adhesion kinase family interacting protein of 200-kDa (FIP200) in normal brain is limited to some neurons and glial cells. On immunohistochemical analysis of biopsies of glioblastoma tumors, we detected FIP200 in the tumor cells, tumor-associated endothelial cells, and occasional glial cells. Human glioblastoma tumor cell lines and immortalized human astrocytes cultured in complete media also expressed FIP200 as did primary human brain microvessel endothelial cells (MvEC), which proliferate in culture and resemble reactive endothelial cells. Downregulation of endogenous expression of FIP200 using small interfering RNA resulted in induction of apoptosis in the human glioblastoma tumor cells, immortalized human astrocytes, and primary human brain MvEC. It has been shown by other investigators using cells from other tissues that FIP200 can interact directly with, and inhibit, proline-rich tyrosine kinase 2 (Pyk2) and focal adhesion kinase (FAK). In the human glioblastoma tumor cells, immortalized human astrocytes, and primary human brain MvEC, we found that downregulation of FIP200 increased the activity of Pyk2 without increasing its expression, but did not affect the activity or expression of FAK. Coimmunoprecipitation and colocalization studies indicated that the endogenous FIP200 was largely associated with Pyk2, rather than FAK, in the glioblastoma tumor cells and brain MvEC. Moreover, the pro-apoptotic effect of FIP200 downregulation was inhibited significantly by a TAT-Pyk2-fusion protein containing the Pyk2 autophosphorylation site in these cells. In summary, downregulation of endogenous FIP200 protein in glioblastoma tumor cells, astrocytes, and brain MvECs promotes apoptosis, most likely due to the removal of a direct interaction of FIP200 with Pyk2 that inhibits Pyk2 activation, suggesting that FIP200 expression may be required for the survival of all three cell types found in glioblastoma tumors
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