confirmed positive Ames test results

This differential regulation of cytokine activity, and specially IL 6 activity, offers the foundation for lenalidomide altering the bone marrow micro-environment where the aberrant expression of pro-inflammatory cytokines is important for the survival Foretinib and development of MM cells. More over, inhibition of VEGF by lenalidomide may possibly alter the bone-marrow microvasculature, thus making the tumor micro-environment less hospitable for MM cell progress, migration, and survival. VEGF inhibition likely does occur via the PI3K/Akt signaling pathway, which commonly becomes phosphorylated in response to VEGF stimulation. Lenalidomide is up to 2000 times more potent than thalidomide in stimulating the expansion of T cells and up to times more potent at increasing the release of interferon and IL 2. This T cell costimulatory Skin infection activity implies that lenalidomide can become an adjuvant to promote type 1 cell mediated antitumor immune responses involving CD8 cytotoxic T cells and equally CD4 T helper cells. The power of NF B action in antigen primed T cells and lenalidomide to improve activator protein 1 has been proposed as a T cell costimulatory process, which may not simply over come T cell anergy, but also potentiates any non T cell receptor mediated signaling. Along with bolstering the adaptive immune response, there's also evidence that lenalidomide can improve natural immunity and natural killer cell mediated lysis of MM cells in particular via its consequences on IL 2 production by T cells. Lenalidomide continues to be shown to specifically potentiate apoptosis of MM cells via a few paths. Included in these are inhibition of expression of the cellular inhibitor of apoptosis protein 2, potentiation of the activities of other apoptosis inducers including TNF related apoptosisinducing ligand, increased sensitivity to Fas induction, and increased caspase 8 activation. Caspase 8, a built-in component IPA-3 of Fas mediated apoptosis, is greatly upregulated by lenalidomide. 63 In addition, dexamethasone activates caspase 9 suggesting that the two drugs in combination generate double indicators with the capacity of increased cell death. Lenalidomide has been associated with direct anti-proliferative action against MM cells in the absence of immune cells or proapoptotic things by causing G1 growth arrest. Notably, lenalidomide inhibits the proliferation of malignant B cells while protecting normal CD34 progenitor cells. The many mechanisms of action of lenalidomide are described in Figure 4. Clinical evidence for lenalidomide in MM Newly identified disease Lenalidomide isn't yet accepted for use in patients with previously untreated disease. Nevertheless, a few clinical studies have reported promising response and survival benefits in this group of patients.