The Immune Microenvironment in Multiple Myeloma: Friend or Foe?
by
, , , and
Raquel Lopes
1,2
,
Joana Caetano
1,3,4
,
Bruna Ferreira
1,4,
Filipa Barahona
1,4,
Emilie Arnault Carneiro
1 and
Cristina João
1,3,4,* 
1
Lymphoma and Myeloma Research Programme, Champalimaud Centre for the Unknown, 1400-038 Lisbon, Portugal
2
Faculty of Medicine, University of Lisbon, 1649-028 Lisbon, Portugal
3
Hemato-Oncology Department, Champalimaud Centre for the Unknown, 1400-038 Lisbon, Portugal
4
Faculty of Medical Sciences, NOVA Medical School, 1169-056 Lisbon, Portugal
*
Author to whom correspondence should be addressed.
Cancers 2021, 13(4), 625; https://doi.org/10.3390/cancers13040625
Submission received: 4 January 2021
/
Revised: 27 January 2021
/
Accepted: 2 February 2021
/
Published: 5 February 2021
(This article belongs to the Special Issue Tumor Microenvironment and Exacerbation Mechanism in Multiple Myeloma)
Simple Summary
The crosstalk between multiple myeloma and immune cells within the bone marrow niche has been identified as an emerging hallmark of this hematological disease. As our knowledge on this interplay increases, it becomes more evident that successful treatment approaches need to boost the body’s natural defenses through immunotherapy. The present review will focus on the mechanisms by which myeloma cancer cells turn immune populations into their “partners in crime”. Additionally, we will provide an overview of currently ongoing pre-clinical studies targeting the bone marrow immune microenvironment.
Abstract
Multiple myeloma (MM) is one of the most prevalent hematological cancers worldwide, characterized by the clonal expansion of neoplastic plasma cells in the bone marrow (BM). A combination of factors is implicated in disease progression, including BM immune microenvironment changes. Increasing evidence suggests that the disruption of immunological processes responsible for myeloma control ultimately leads to the escape from immune surveillance and resistance to immune effector function, resulting in an active form of myeloma. In fact, one of the hallmarks of MM is the development of a permissive BM milieu that provides a growth advantage to the malignant cells. Consequently, a better understanding of how myeloma cells interact with the BM niche compartments and disrupt the immune homeostasis is of utmost importance to develop more effective treatments. This review focuses on the most up-to-date knowledge regarding microenvironment-related mechanisms behind MM immune evasion and suppression, as well as promising molecules that are currently under pre-clinical tests targeting immune populations.
