Repository logo

Browsing by Author "Silva, Andreia Cristina Martins"

Now showing 1 - 1 of 1
  • Contribution of the intracellular cholesterol levels for the expression of VEGF-C and VEGFR-3 in acute myeloid leukemia
    Publication . Silva, Andreia Cristina Martins; Silva, Gabriela
    Some subsets of Acute Myeloid Leukemia (AML) cells express the Vascular Endothelial Receptor 3 (VEGFR-3), a receptor for the Vascular Endothelial Growth Factor-C (VEGF-C). The VEGFR-3/VEGF-C axis has been related to many cancers, including leukemia, due to the promotion of cell proliferation, chemotherapy resistance and tumor aggressiveness. At the molecular level VEGF-C signaling has been shown to induce the expression of the Bcl-2 anti-apoptotic factor. Cholesterol has been reported to modulate the expression of VEGFR’s in AML. Here, we hypothesize that intracellular cholesterol levels could modulate signaling through the VEGFR-3/VEGF-C axis, contributing towards increased leukemia aggressiveness. To test this hypothesis we either enriched or partially depleted cholesterol from the THP-1 and HEL cell lines with Methyl-β-Cyclodextrin + cholesterol complexes and Methyl-β-Cyclodextrin alone, respectively. It was seen that Methyl-β-Cyclodextrin compromises cell viability, so we tested concentrations of 0,2 mM. In these conditions we looked at VEGFR-3, VEGF-C and Bcl-2 expression by RQ-PCR and Western Blot; VEGFR-3 expression was also assessed by flow cytometry. Our preliminary results show that cholesterol enrichment of cells leads to a decrease of VEGFR-3 mRNA levels, while cholesterol depletion leads to an increase of VEGF-C mRNA levels. No differences in Bcl-2 have been detected. We are now confirming these results at the protein level. By flow cytometry VEGFR-3 expression didn’t show differences between conditions. Subsequent experiments will include in vitro functional assays to assess cell viability, proliferation and resistance to apoptosis. This work may contribute to better understand how VEGF-C signaling pathways are regulated in leukemia. As VEGF-C expression has been associated with resistance to chemotherapy by AML cells, this work may contribute to better understand how resistance is achieved.
    2013Master thesis Open Access Show more