ABSTRACT

Gene therapy has attracted much interest since the first submissions of phase I clinical trials in the early 1990s, for the treatment of inherited genetic diseases. Preliminary results were very encouraging and prompted many investigators to submit protocols for phase I and phase II clinical trials for the treatment of inherited genetic diseases and cancer. The possible application of gene transfer technology to treat AIDS, cardiopathies, and neurologic diseases is under evaluation. Some viral vectors have already been used to deliver HIV-1 subunits to immunize volunteers who are participating in the AIDS vaccine programs in the USA. However, gene delivery systems still need to be optimized in order to achieve effective therapeutic interventions. The purpose of this review is to summarize the latest achievements in improving gene delivery systems, their current application in preclinical studies and in therapy, and the most pressing issues that must be addressed in the area of vector design.

Imatinib (IM) is considered the gold standard for chronic myeloid leukemia (CML) treatment, although resistance is emerging as a significant problem. The proinflammatory cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8) play an important role in cell proliferation, survival, and resistance to glucocorticoid-mediated cell death. Several transcription factors such as NF-KB and AP-1 are activated in response to physiopathological increases and modulation of intracellular calcium levels. Our previous study demonstrated that lymphocytes from CML patients showed dysregulated calcium homeostasis and oxidative stress. Alteration in ionized calcium concentration in the cytosol has been implicated in the initiation of secretion, contraction, and cell proliferation. In this study, we hypothesized that IL-6, IL-8, NF-kB, AP-1, and intracellular calcium may be used as selective and prognostic factors to address the follow-up in CML patients treated with imatinib. Our results demonstrated a significant down-regulation in IL-6 and IL-8 release as well as NF-kB and AP-1 activation in lymphomonocytes from Imatinib-treated patients, compared to samples from untreated patients. In parallel, IM treatment, in vivo and in vitro, were able to modulate the intracellular calcium concentration of peripheral blood mononuclear cells of CML patients by acting at the level of InsP(3) receptor in the endoplasmic reticulum and at the level of the purinergic receptors on plasma membrane. The results of this study show that measurements of NF-kB, AP-1, IL-6, IL-8, and intracellular calcium in CML patients treated with Imatinib may give important information to the hematologist on diagnostic criteria and are highly predictive in patients with newly diagnosed CML.