Stem Cell Transplantation for Multiple Myeloma

Paclitaxel-releasing mesenchymal stromal cells inhibit the growth of multiple myeloma cells in a dynamic 3D culture system

Multiple myeloma is an aggressive tumour able to suppress osteoblastogenesis probably mediated by bone marrow mesenchymal stromal cells (BM-MSCs) that can also support plasma cell growth/survival. The use of MSCs for multiple myeloma therapy is a controversial topic because of the contradictory results on the capacity of MSCs to inhibit or to promote cancer growth. Our previous studies demonstrated that MSCs could be loaded with Paclitaxel (PTX) and used to deliver the drug in situ in amount affecting tumour growth (in vitro and in vivo). Therefore, independently on the discussed action of MSCs in myeloma, MSCs could represent a 'trojan horse' to vehicle and deliver anti-tumour agents into bone marrow. This study confirms, by an in vitro 3D dynamic culture system, that PTX loaded BM-MSCs (PTXr-MSCs) are active on the proliferation of RPMI 8226, a human myeloma cell line. Our results demonstrated a dramatic suppression of myeloma cell growth by PTXr-MSCs, suggesting that drug loaded MSCs could be a tool to deliver drug into the bone marrow. Drug releasing MSCs provide a therapeutic approach to potentiate the existing treatments against a very aggressive malignancy as multiple myeloma. Copyright © 2016 John Wiley & Sons, Ltd.

Mesenchymal stem cells inhibit multiple myeloma cells via the Fas/Fas ligand pathway

Introduction

Cell-based therapy represents a new frontier in the treatment of a wide variety of human diseases traditionally associated with morbidity outcomes, including those involving inflammation, autoimmunity, tissue damage, and cancer. However, the use of mesenchymal stem cells (MSCs) to treat multiple myeloma (MM) bone disease has raised concerns. Specifically, evidence has shown that infused MSCs might support tumor growth and metastasis.

Methods

In this study, we used a standard disseminated MM model in mice to identify the in vivo effects of intravenous MSC infusion. In addition, a series of in vitro co-culture assays were preformed to explore whether Fas/Fas ligand (Fas-L) is involved in the inhibitory effects of MSCs on MM cells.

Results

In the MM mouse model, treatment of MSCs with highly expressed Fas ligand (Fas-L^high MSCs) showed remarkable inhibitory effects on MM indenization in terms of extending the mouse survival rate and inhibiting tumor growth, bone resorption in the lumbus and collum femoris, and MM cell metastasis in the lungs and kidneys. In addition, reduced proliferation and increased apoptosis of MM cells was observed when co-cultured with Fas-L^high MSCs in vitro. Furthermore, mechanistically, the binding between Fas and Fas-L significantly induced apoptosis in MM cells, as evidenced through an increase in the expression of apoptosis marker and Fas in MM cells. In contrast, Fas-L^null MSCs promote MM growth.

Conclusions

These data suggest that Fas/Fas-L-induced MM apoptosis plays a crucial role in the MSC-based inhibition of MM growth. Although whether MSCs inhibit or promote cancer growth remains controversial, the levels of Fas-L expression in MSCs determine, at least partially, the effects of MSCs on MM cell growth.

Dissecting the role of bone marrow stromal cells on bone metastases

Tumor-induced bone disease is a dynamic process that involves interactions with many cell types. Once metastatic cancer cells reach the bone, they are in contact with many different cell types that are present in the cell-rich bone marrow. These cells include the immune cells, myeloid cells, fibroblasts, osteoblasts, osteoclasts, and mesenchymal stem cells. Each of these cell populations can influence the behavior or gene expression of both the tumor cells and the bone microenvironment. Additionally, the tumor itself can alter the behavior of these bone marrow cells which further alters both the microenvironment and the tumor cells. While many groups focus on studying these interactions, much remains unknown. A better understanding of the interactions between the tumor cells and the bone microenvironment will improve our knowledge on how tumors establish in bone and may lead to improvements in diagnosing and treating bone metastases. This review details our current knowledge on the interactions between tumor cells that reside in bone and their microenvironment.

Autologous Hematopoietic Stem Cell Transplantation for Multiple Myeloma without Cryopreservation

High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation is considered the standard of care for multiple myeloma patients who are eligible for transplantation. The process of autografting comprises the following steps: control of the primary disease by using a certain induction therapeutic protocol, mobilization of stem cells, collection of mobilized stem cells by apheresis, cryopreservation of the apheresis product, administration of high-dose pretransplant conditioning therapy, and finally infusion of the cryopreserved stem cells after thawing. However, in cancer centers that treat patients with multiple myeloma and have transplantation capabilities but lack or are in the process of acquiring cryopreservation facilities, alternatively noncryopreserved autologous stem cell therapy has been performed with remarkable success as the pretransplant conditioning therapy is usually brief.

Three palonosetron regimens to prevent CINV in myeloma patients receiving multiple-day high-dose melphalan and hematopoietic stem cell transplantation

BACKGROUND

Explore safety and efficacy of three palonosetron-containing regimens for emesis prevention over 7 days in multiple myeloma (MM) patients receiving melphalan (100 mg/m(2)) and hematopoietic stem cell transplantation (HSCT).

PATIENTS AND METHODS

Randomized, double-blind pilot study in MM patients (n=73) receiving 1, 2, or 3 days of 0.25 mg palonosetron (30-s i.v. bolus) 30 min before melphalan (days -2 and -1) and HSCT (day 0). Patients received dexamethasone (20 mg i.v., days -2 and -1) immediately before or after study drug/placebo. Daily diaries recorded emesis, rescue medication, nausea duration, and adverse events (AEs).

RESULTS

Seven-day complete protection (no emesis) occurred in 41.7% [95% confidence interval (CI) 22.1% to 63.4%], 41.7% (95% CI 22.1% to 63.4%), and 44.0% (95% CI 24.2% to 65.1%) of patients receiving 1, 2, or 3 days of palonosetron, respectively (P=0.43). Complete response (emesis free without rescue medication) occurred in 8.3%, 20.8%, and 20.0% (P=0.14). Common AEs (≥10%) were mild-to-moderate diarrhea, constipation, headache, insomnia, and flatulence. No serious AEs occurred.

CONCLUSIONS

Palonosetron with dexamethasone was safe and effective in preventing emesis in MM patients receiving melphalan and HSCT. This pilot study with a limited number of patients suggests that multiple doses of palonosetron could be more effective than a single dose in making patients emesis free without need for rescue medication. However, even multiple doses of palonosetron resulted in only 20% of patients being emesis free without rescue medication, suggesting that further improvement will require development of more effective combination antiemetic therapy.

Ifosfamide, epirubicin, and etoposide (IEV) mobilize peripheral blood stem cells more efficiently than cyclophosphamide/etoposide

High-dose chemotherapy with autologous stem cell support is an effective treatment in advanced multiple myeloma. In this study, we compare chemotherapy with ifosfamide, epirubicin, and etoposide (IEV) or cyclophosphamide and etoposide (CE) in 47 patients with multiple myeloma with regard to stem cell mobilization, toxicity, and tumor response. The proportion of patients reaching the threshold of >6 x 10(6) CD34+ cells/kg body weight was significantly higher in the IEV group (97% vs 71%), and more CD34+ cells (10 x 10(6) vs 3.5 x 10(6) cells/kg; p = 0.002) could be collected by the first leukapheresis associated with less leukaphereses needed. Non-hematopoietic side effects were mild with nausea being more frequent after IEV treatment (30% vs 7%). Grade 3/4 neutropenia (thrombocytopenia) occurred in 89 and 100% (55 and 44%) of the patients. There was one treatment-related death due to septic shock in the IEV group. Grade 3/4 anemia was more frequent in the IEV group (19% vs 0%). Forty-two percent (IEV) and 50% (CE) received inpatient treatment for neutropenic fever. In 20 and 7% of the patients, a partial response was observed after IEV and CE. However, the overall response rate (complete response and partial tumor response) after mobilization and tandem high-dose chemotherapy was 75% after IEV and 78% after CE and, thus, independent of the mobilization. In summary, both treatment protocols can readily be used for the mobilization of peripheral blood stem cells with comparable major toxicities and similar tumor response rates. However, the efficiency of the stem cell mobilization was significantly higher after IEV treatment.