RESUMEN
Several studies have demonstrated that the serum of patients with cancer contains antibodies that react with a group of autoantigens denominated tumor-associated antigens (TAA). TAA can be detected prior to clinical diagnosis; thus, they would be ideal biomarkers for early detection of cancer, using only a few microliters of a patient's serum. In the current study, we used an immune proteomic approach, combining two-dimensional (2D) electrophoresis, Western blot, and matrix-associated laser desorption/ionization-mass spectrometry (MALDI-MS) methods to identify TAA in the sera of patients diagnosed with breast cancer. Sera were obtained from 36 newly diagnosed patients with stage II breast cancer and those from 36 healthy volunteers were evaluated for the presence of the TAA. Alpha 2HS-glycoprotein (AHSG) antibodies were detected in 33 of 36 patients with breast cancer (91.7%) and in only 3 of 36 healthy patients (controls, 8.3%). Sensitivity of detection of autoantibodies against AHSG in patients with breast cancer was 91.7%. AHSG was detected in cancer tissue by immunohistochemistry. Our results strongly suggest that the presence of serum autoantibodies against AHSG protein may be useful as serum biomarkers for early-stage breast cancer screening and minimally invasive diagnosis in Mexican populations. BIOLOGICAL SIGNIFICANCE: In the present study, 2D immunoblot analysis was used to make a screening in samples of sera from patients with a diagnosis of early-stage breast cancer, in order to identify some autoantibodies that react against TAA. Proteins identified in the present study, particularly alpha 2HS-glycoprotein (AHSG), might be useful as potential biomarkers for breast cancer in early stages for Mexican populations.
Asunto(s)
Anticuerpos Antineoplásicos/sangre , Antígenos de Neoplasias/sangre , Autoanticuerpos/sangre , Neoplasias de la Mama/sangre , alfa-2-Glicoproteína-HS/metabolismo , Biomarcadores de Tumor/sangre , Femenino , Humanos , México , Estadificación de Neoplasias , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
The midgut of anopheline mosquito is the entry of Plasmodium, the causative agent of malaria.When the mosquito feeds on parasite infected host, Plasmodium parasites reach the midgut and must confront digestive enzymes, the innate immune response and go across the peritrophic matrix (PM), a thick extracellular sheath secreted by the mosquito midgut epithelial cells. Then, to continue its development, the parasite must reach the salivary glands to achieve transmission to a vertebrate host. We report here the morphological and biochemical descriptions of the midgut changes after a blood meal in Anopheles albimanus. Before blood feeding, midgut epithelial cells contained numerous electrondense vesicles distributed in the central to apical side. These vesicles were secreted to the luminal side of the midgut after a blood meal. At early times after blood ingest, the PM is formed near microvilli as a granulous amorphous material and after it consolidates forming a highly organized fibrillar structure, constituted by layers of electrondense and electronlucent regions. Proteomic comparative analysis of sugar and blood fed midguts showed several molecules that modify their abundance after blood intake; these include innate immunity, cytoskeletal, stress response, signaling, and digestive, detoxifying and metabolism enzymes. Biological significance In the midgut of mosquitoes during bloodfeeding, many simultaneous processes occur, including digestion, innate immune activities, cytoskeleton modifications, construction of a peritrophic matrix and hormone production, between others. Mechanical forces are very intense during bloodfeeding and epithelial and muscular cells must resist the stress, modifying the actin cytoskeleton and coordinating intracellular responses by signaling. Microorganisms present in midgut contents reproduce and interact with epithelial cells triggering innate immune response. When infectious agents are present in the blood meal they must traverse the peritrophic matrix, an envelope formed from secretion products of epithelial cells, and evade the immune system in order to reach the epithelium and continue their journey towards salivary glands, in preparation for the transmission to the new hosts. During all these processes, proteins of mosquitoes are modified in order to deal with mechanical and biological challenges, and the aim of this work is to study these changes.