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Gamez, B.

Publications and source records attributed to Gamez, B..

2 recordsLinked to original sources

Bisphosphonates Trigger Anti-Ageing Effects Across Multiple Cell Types and Protect Against Senescence

Bisphosphonates (BPs) have been the major class of medicines used to treat disorders of excessive bone loss for over five decades. Recently it has been recognized that BPs may also have additional significant beneficial extra-skeletal effects. These include a reduction of all-cause mortality and of conditions commonly linked to ageing, such as cancer and cardiovascular disease. Here we show that bisphosphonates co-localize with lysosomal and endosomal organelles in non-skeletal cells and stimulate cell growth at low doses. In vivo spatial transcriptomic analysis revealed differentially expressed senescence markers in multiple organs of aged BP-treated mice, and a shift in cellular composition toward those of young counterparts. Similarly, a 5000-plex plasma proteome analysis from osteopenic patients before and after BP-treatment showed significant alterations in [~]400 proteins including GTPase regulators and markers of senescence, autophagy, apoptosis, and inflammatory responses. Furthermore, treatment with BPs protected against the onset of senescence in vitro. Proteome-wide target deconvolution using 2D thermal profiling revealed novel BP-binding targets (PHB2, ASAH1), and combined with RNA- and ATAC-seq of BP-treated cells and patient data, suggests downstream regulation of the MEF2A transcription factor within the heart. Collectively, these results indicate how BPs may beneficially modify the human plasma proteome, and directly impact multiple non-skeletal cell types through previously unidentified proteins, thereby influencing a range of pathways related to senescence and ageing.

cell biology↗

High cholesterol increases myeloma tumour burden and promotes resistance to bortezomib

Multiple myeloma (MM) is an incurable hematologic cancer where malignant plasma cells accumulate in the bone marrow (BM), with disease progression highly dependent on cellular interactions. Obesity is a major risk factor for myeloma, however the underlying mechanisms are unclear. Here we used a murine myeloma model to show that a high cholesterol diet increases local and circulating levels of low density lipoprotein cholesterol (LDL), increasing bone marrow tumour burden in vivo. Exogenous LDL induced bortezomib-specific drug resistance in metabolically stressed myeloma cells in vitro and ex vivo. RNA-seq analysis revealed bortezomib-induced changes in the cholesterol biosynthesis/homeostasis pathway that were completely reverted with LDL pretreatment. In silico analysis of patient data supported a role for cholesterol in response to bortezomib-based therapies. Targeted proteome profiling revealed changes in expression of the adipokine resistin in the bone marrow of cholesterol-treated or myeloma-bearing mice, with elevated resistin expression observed in MGUS patients. Bone marrow adipocytes were found to be a major source of resistin, which was further increased in response to LDL. In summary, we demonstrate that high cholesterol promotes both myeloma development and bortezomib resistance, identifying resistin as a potential mediator so revealing new mechanisms underlying myeloma pathogenesis.

cancer biology↗