Changes in circulating endothelial progenitor cells predict responses of multiple myeloma patients to treatment with bortezomib and dexamethasone

Impact of CD34/CD309 expression in circulating endothelial progenitor cells on prognosis and response to bortezomib therapy in multiple myeloma

Multiple myeloma (MM) is a prevalent yet incurable hematologic malignancy. Despite the proven efficacy of proteasome inhibitors in treating MM, resistance to Bortezomib-based treatments persists in a subset of patients. This case control study explores the potential of circulating endothelial progenitor cells (EPCs) as biomarkers for predicting response to Proteasome Inhibitor based therapy combined with Dexamethasone in MM patients. This study was conducted on 105 MM patients receiving bortezomib plus dexamethasone therapy and 90 healthy individuals as a control group. Utilizing 8-color multi-parameter flow cytometry, we assessed the levels of circulating EPCs, identified through CD34 FITC and CD309 PE markers at diagnosis and after one treatment cycle (4 weeks). Our findings revealed that patients exhibiting poor response to therapy showed significantly higher CD34/CD309 values than those with a good response (p < 0.001). The delineation of response based on CD34/CD309 expression was established with a cutoff ≤ 0.9 for percentage (yielding 100% sensitivity and 94.1% specificity) and ≤ 12.5 for absolute value (also with 100% sensitivity and 94.1% specificity). These results underscore the potential of EPC population levels, as quantified by CD34/CD309, to serve as a predictive biomarker for immunomodulatory treatment in MM patients undergoing Proteasome Inhibitor and Dexamethasone therapy.

Circulating Endothelial Cell Kinetic in Patients with Multiple Myeloma Who Receive Autologous Hematopoietic Stem Cell Transplantation

INTRODUCTION

Neoangiogenesis has a crucial role in multiple myeloma (MM), and circulating endothelial cells (CECs) contribute to neovascularization by inducing tumor progression and metastasis and by repairing damage to bone marrow vasculature after stem cell transplantation (HSC). We recently proved in a national multicenter study the possibility to reach a high-level standardization in CEC count and analysis based on a polychromatic flow cytometry Lyotube (BD). Our study aimed at assessing the kinetics of CECs in patients with MM undergoing autologous hematopoietic stem cell transplantation (Au-HSCT).

METHODS

Blood samples for analysis were collected at different time points before (T0, T1) and after (T2, T3, T4) Au-HSCT. For each sample, 20 × 106 leukocytes were processed as already described (Lanuti 2016 e 2018) through a multistep procedure. CECs were eventually identified as 7-ADDneg/Syto16pos/CD45neg/CD34pos/CD146pos.

RESULTS

Twenty-six MM patients were enrolled in the study. Overall, we observed a constant increase of CECs values from T0 to T3 (day of neutrophil engraftment) followed by decrease at T4 (100 days after transplantation). Using the median value of CECs at T3, we could define a cut-off concentration of 618/mL, with patients with more infective complications having CECs above that value (9/13 vs. 2/13; p = 0.005).

CONCLUSION

CECs value may be a function of endothelial damage caused by conditioning regimen, as suggested by the increase of their level during the engraftment period. A more severe endothelial damage is reflected by the increase of infective complications in patients with higher CECs value at T3.

Anti-VEGF Drugs in the Treatment of Multiple Myeloma Patients

The interaction between the bone marrow microenvironment and plasma cells plays an essential role in multiple myeloma progression and drug resistance. The vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) pathway in vascular endothelial cells activates and promotes angiogenesis. Moreover, VEGF activates and promotes vasculogenesis and vasculogenic mimicry when it interacts with VEGF receptors expressed in precursor cells and inflammatory cells, respectively. In myeloma bone marrow, VEGF and VEGF receptor expression are upregulated and hyperactive in the stromal and tumor cells. It has been demonstrated that several antiangiogenic agents can effectively target VEGF-related pathways in the preclinical phase. However, they are not successful in treating multiple myeloma, probably due to the vicarious action of other cytokines and signaling pathways. Thus, the simultaneous blocking of multiple cytokine pathways, including the VEGF/VEGFR pathway, may represent a valid strategy to treat multiple myeloma. This review aims to summarize recent advances in understanding the role of the VEGF/VEGFR pathway in multiple myeloma, and mainly focuses on the transcription pathway and on strategies that target this pathway.

Endothelial progenitor cells in multiple myeloma neovascularization: a brick to the wall

Multiple myeloma (MM) is characterized by the clonal expansion of plasma cells in the bone marrow that leads to events such as bone destruction, anaemia and renal failure. Despite the several therapeutic options available, there is still no effective cure, and the standard survival is up to 4 years. The evolution from the asymptomatic stage of monoclonal gammopathy of undetermined significance to MM and the progression of the disease itself are related to cellular and molecular alterations in the bone marrow microenvironment, including the development of the vasculature. Post-natal vasculogenesis is characterized by the recruitment to the tumour vasculature of bone marrow progenitors, known as endothelial progenitor cells (EPCs), which incorporate newly forming blood vessels and differentiate into endothelial cells. Several processes related to EPCs, such as recruitment, mobilization, adhesion and differentiation, are tightly controlled by cells and molecules in the bone marrow microenvironment. In this review, the bone marrow microenvironment and the mechanisms associated to the development of the neovasculature promoted by EPCs are discussed in detail in both a non-pathological scenario and in MM. The latest developments in therapy targeting the vasculature and EPCs in MM are also highlighted. The identification and characterization of the pathways relevant to the complex setting of MM are of utter importance to identify not only biomarkers for an early diagnosis and disease progression monitoring, but also to reveal intervention targets for more effective therapy directed to cancer cells and the endothelial mediators relevant to neovasculature development.

Novel panel of protein biomarkers to predict response to bortezomib-containing induction regimens in multiple myeloma patients

BACKGROUND

Multiple myeloma (MM) is a complex heterogeneous disease. Various risk stratification models have been recommended including cytogenetic and FISH analysis to identify high-risk patients who may benefit from novel treatments, but such facilities are not widely available. The International Scoring System (ISS) using beta-2-microglobulin and albumin remains a widely used prognostic scoring system in many clinical practices; however it is not useful in predicting response to treatment in MM. The aim of this study is to identify clinically useful biomarkers to predict response to treatment containing bortezomib.

METHODS

17 MM patient serum samples (9 responders/8 non-responders) were used for the discovery phase (label-free mass spectrometry) and an additional 20 MM patient serum samples were used for the ELISA-based validation phase (14 responders/6 non-responders).

RESULTS

CLU and ANG mean levels were higher in the responders group, while Complement C1q had lower concentrations. The combination of all standard biomarkers (albumin, beta-2-microglobulin (ß2M), paraprotein and kappa/lambda (K/L) ratio) had an AUC value of 0.71 with 65% correct classification, while an overall combination of new candidate protein biomarkers with standard biomarkers had an AUC value of 0.89 with 85.3% correct classification.

CONCLUSIONS

A combination of new and standard biomarkers consisting of CLU, ANG, C1Q, albumin, ß2M, paraprotein and K/L ratio may have potential as a novel panel of biomarkers to predict MM response to treatment containing bortezomib.

GENERAL SIGNIFICANCE

Use of this biomarker panel could facilitate a more personalized therapy approach and to minimize unnecessary side effects from ineffective drugs.

The lack of increases in circulating endothelial progenitor cell as a negative predictor for pathological response to neoadjuvant chemotherapy in breast cancer patients

Circulating endothelial progenitor cells are a potential surrogate marker for angiogenesis. Little is known about the alteration of circulating endothelial progenitor cell counts during neoadjuvant chemotherapy. Our goal was to reveal the alteration in CEP counts in association with response to neoadjuvant chemotherapy in patients with breast cancer. We measured the number of circulating endothelial progenitor cells (CD31⁺CD34⁺CD133⁺CD45^dim) by four-color flow cytometry using blood samples from 57 patients with breast cancer who received neoadjuvant chemotherapy (5-fluorouracil + epirubicin + cyclophosphamide (FEC), docetaxel + cyclophosphamide (TC), cisplatin + docetaxel (TP)). There was no significant difference in the baseline circulating endothelial progenitor cell counts with respect to the clinical and pathological background factors. Circulating endothelial progenitor cell counts increased after the initiation of chemotherapy (pre-1st vs. pre-2nd cycle, p = 0.0035; pre-1st vs. pre-4th cycle, p = 0.047). An increase of circulating endothelial progenitor cell counts from pre-1st to pre-2nd cycle was associated with pCR (p = 0.013 for χ² test). A multivariate analysis, including subtype, and clinical response showed that the lack of circulating endothelial progenitor cell increases from pre-1st to pre-2nd cycle was an independent negative predictor of pCR (p = 0.002). Our data suggest that alterations in circulating endothelial progenitor cell counts are associated with treatment response. The circulating endothelial progenitor cell count could be a useful biomarker for monitoring chemotherapeutic response.

Breast cancer patients do better after preoperative chemotherapy if their numbers of circulating endothelial progenitor cells (CEPs) go up. A team from Japan led by Takayuki Ueno from the Kyorin University School of Medicine in Tokyo studied 57 women who underwent neoadjuvant chemotherapy to shrink the size of their tumors before surgery. The researchers measured the number of CEPs—cells that derive from the bone marrow and can help build new blood vessels around tumors—both before and during chemotherapy. They found no link between overall CEP counts and treatment response. However, patients whose CEP numbers went up between cycles of chemotherapy had better outcomes. The authors suggest that CEP counts could be used as a diagnostic tool for predicting responses to neoadjuvant chemotherapy, although larger studies are needed to confirm their initial findings