RESUMEN
Endocan, previously called endothelial cell specific molecule-1, is a soluble proteoglycan of 50 kDa, constituted of a mature polypeptide of 165 amino acids and a single dermatan sulphate chain covalently linked to the serine residue at position 137. This dermatan sulphate proteoglycan, which is expressed by the vascular endothelium, has been found freely circulating in the bloodstream of healthy subjects. Experimental evidence is accumulating that implicates endocan as a key player in the regulation of major processes such as cell adhesion, in inflammatory disorders and tumor progression. Inflammatory cytokines such as TNF-alpha, and pro-angiogenic growth factors such as VEGF, FGF-2 and HGF/SF, strongly increased the expression, synthesis or the secretion of endocan by human endothelial cells. Endocan is clearly overexpressed in human tumors, with elevated serum levels being observed in late-stage lung cancer patients, as measured by enzyme-linked immunoassay, and with its overexpression in experimental tumors being evident by immunohistochemistry. Recently, the mRNA levels of endocan have also been recognized as being one of the most significant molecular signatures of a bad prognosis in several types of cancer including lung cancer. Overexpression of this dermatan sulphate proteoglycan has also been shown to be directly involved in tumor progression as observed in mouse models of human tumor xenografts. Collectively, these results suggest that endocan could be a biomarker for both inflammatory disorders and tumor progression as well as a validated therapeutic target in cancer. On the basis of the recent successes of immunotherapeutic approaches in cancer, the preclinical data on endocan suggests that an antibody raised against the protein core of endocan could be a promising cancer therapy.
Asunto(s)
Antineoplásicos/administración & dosificación , Biomarcadores de Tumor/metabolismo , Sistemas de Liberación de Medicamentos , Células Endoteliales/metabolismo , Proteínas de Neoplasias/metabolismo , Proteoglicanos/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular Tumoral , Transformación Celular Neoplásica/efectos de los fármacos , Transformación Celular Neoplásica/metabolismo , Regulación de la Expresión Génica , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Datos de Secuencia Molecular , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Conformación Proteica , Proteoglicanos/química , Proteoglicanos/genética , Transcripción GenéticaRESUMEN
The procedure used to establish in situ (without cell trypsinization) the growth kinetics characteristics of anchorage-dependent cells propagated on microcarriers by Aperture Impedance Pulse Spectroscopy can be replaced by a novel method based on the time-dependent shifts of the size distribution histograms of cell-laden microcarriers. This we have named Laser Diffraction Particle Sizing.
RESUMEN
Immunogenicity and protective efficacy of a DNA vaccine encoding Ag85A from Mycobacterium tuberculosis were compared in BALB/c and C57BL (B6 and B10) mice immunized by intramuscular (i.m.) needle injection or epidermal gene gun (gg) bombardment. In BALB/c mice, gg immunization could induce elevated antibody and cytotoxic T lymphocyte responses with plasmid doses 50-fold lower than those required for i.m. immunization. Interleukin-2 (IL-2) and gamma interferon (IFN-gamma) secretion, however, was much lower in gg-immunized than in i.m.-immunized BALB/c mice. On the other hand, C57BL mice reacted only very weakly to gg immunization, whereas elevated Ag85A-specific antibody, IL-2, and IFN-gamma responses (significantly higher than in BALB/c mice) were detected following vaccination by the i.m. route. Antibody isotypes were indicative of Th2 activation following gg injection of BALB/c and of Th1 activation following i.m. injection of C57BL mice. Finally, C57BL but not BALB/c mice were protected by i.m. Ag85A DNA immunization against intravenous M. tuberculosis challenge, as measured by reduced numbers of CFU in spleen and lungs, compared to animals vaccinated with control DNA. Gene gun immunization was not effective in either BALB/c or C57BL mice. These results indicate that i.m. DNA vaccination is the method of choice for the induction of protective Th1 type immune responses with the Ag85A tuberculosis DNA vaccine.