Isolation of Human CD138+ Microparticles from the Plasma of Patients with Multiple Myeloma

Abstract

The confinement of multiple myeloma (MM) to the bone marrow microenvironment requires an invasive bone marrow biopsy to monitor the malignant compartment. The existing clinical tools used to determine treatment response and tumor relapse are limited in sensitivity mainly because they indirectly measure tumor burden inside the bone marrow and fail to capture the patchy, multisite tumor infiltrates associated with MM. Microparticles (MPs) are 0.1- to 1.0-μm membrane vesicles, which contain the cellular content of their originating cell. MPs are functional mediators and convey prothrombotic, promalignant, proresistance, and proinflammatory messages, establishing intercellular cross talk and bypassing the need for direct cell-cell contact in many pathologies. In this study, we analyzed plasma cell–derived MPs (CD138+) from deidentified MM patients (n = 64) and normal subjects (n = 18) using flow cytometry. The morphology and size of the MPs were further analyzed using scanning electron microscopy. Our study shows the proof of a systemic signature of MPs in MM patients. We observed that the levels of MPs were significantly elevated in MM corresponding to the tumor burden. We provide the first evidence for the presence of MPs in the peripheral blood of MM patients with potential applications in personalized MM clinical monitoring.

Tumor Cell-Derived Microvesicles Induced Not Epithelial-Mesenchymal Transition but Apoptosis in Human Proximal Tubular (HK-2) Cells: Implications for Renal Impairment in Multiple Myeloma

“…In this study, we enrolled 61 de novo patients with MM (Table 1), and circulating MVs (cirMVs) in the peripheral blood were analyzed using a BD LSR II flow cytometer (BD Biosciences, San Jose, CA, USA) equipped with FACSDiva software. Based on the phenotypic characteristics of MM-MVs and the findings by Krishnan and collegues [23], we used CD138+ cirMVs to represent circulating MM-MVs in patients with MM. Meanwhile, according to the serum creatinine levels (SCr), the patients were classified into two groups (group 1, SCr < 2 mg/dL, n = 45; group 2, SCr ≥ 2 mg/dL, n = 16).…”

Ca2+ mediates extracellular vesicle biogenesis through alternate pathways in malignancy

“…A PBS blank buffer control was run to ensure baseline events were low (data not shown). The number of EVs per µL was calculated using the formula: N = (gated MV events/gated Trucount™ events) × total number of Trucount™ beads [11]. EV events were normalized to individual well cell counts to account for variation in cell numbers between samples as previously described [20].…”

“…Flow cytometry was used to interrogate the Ca 2+ signalling pathways regulating plasma membrane EV biogenesis. The gating parameters for the EV region were defined using 0.3 µm latex beads (R1: the lowest possible limit on forward scatter for BD LSRII) and 1.1 µm beads (R2: represents the upper limit for quantitation of the EV population; Figure 4(a)), as previously described [11]. We observed a significant, 1.5 fold increase in EV biogenesis in hCMEC-D3 cells following 300 nM TG treatment (Figure 4 (b)).…”

Exosome‐associated miRNA profile as a prognostic tool for therapy response monitoring in multiple sclerosis patients

“…Exosomes provide a means of cell-to-cell communication by transporting their cargo, including proteins, lipids, mRNAs, and microRNAs (miRNAs), and delivering it to target cells (10). Representing a molecular bioprint of their parental cells, blood-circulating exosomes are potentially noninvasive biomarkers for early diagnosis and prognosis of various types of diseases (11). Exosomes have been shown to contribute to a number of disease states, including cancer and neurodegenerative conditions (12)(13)(14).…”