JAK1/2 pathway inhibition suppresses M2 polarization and overcomes resistance of myeloma to lenalidomide by reducing TRIB1, MUC1, CD44, CXCL12, and CXCR4 expression

Abstract

Monocytes polarize into pro-inflammatory macrophage-1 (M1) or alternative macrophage-2 (M2) states with distinct phenotypes and physiological functions. M2 cells promote tumour growth and metastasis whereas M1 macrophages show anti-tumour effects. We found that M2 cells were increased whereas M1 cells were decreased in bone marrow (BM) from multiple myeloma (MM) patients with progressive disease (PD) compared to those in complete remission (CR). Gene expression of Tribbles homolog 1 (TRIB1) protein kinase, an inducer of M2 polarization, was increased in BM from MM patients with PD compared to those in CR. Ruxolitinib (RUX) is an inhibitor of the Janus kinase family of protein tyrosine kinases (JAKs) and is effective for treating patients with myeloproliferative disorders. RUX markedly reduces both M2 polarization and TRIB1 gene expression in MM both in vitro and in vivo in human MM xenografts in severe combined immunodeficient mice. RUX also downregulates the expression of CXCL12, CXCR4, MUC1, and CD44 in MM cells and monocytes co-cultured with MM tumour cells; overexpression of these genes is associated with resistance of MM cells to the immunomodulatory agent lenalidomide. These results provide the rationale for evaluation of JAK inhibitors, including MM BM in combination with lenalidomide, for the treatment of MM patients.

Ruxolitinib reverses checkpoint inhibition by reducing programmed cell death ligand‐1 (PD‐L1) expression and increases anti‐tumour effects of T cells in multiple myeloma

“…38 We have recently reported that one potential mechanism through which RUX may provide anti-MM effects is inhibition of M2 polarisation of macrophages. 18 Interestingly, an increase in PD-L1 in the maternal blood initiates PD-L1/PD-1-mediated polarisation of macrophages toward M2 and leads to immune tolerance during gestation. 39 We have found another novel way to regulate the PD-L1/ PD-1 pathway.…”

“…Reverse transcription polymerase chain reaction (RT-PCR) and quantitative analysis were performed as previously described. 18 Total RNA was extracted using the RNeasy kit (Qiagen, Louisville, KY, USA). The complementary DNA (cDNA) was synthesised using a Superscript III reverse transcriptase kit (Life Technology, Grand Island, NY, USA).…”

Combined anti-fibrotic and anti-inflammatory properties of JAK-inhibitors on macrophages in vitro and in vivo: Perspectives for scleroderma-associated interstitial lung disease

“…Total RNA were extracted from cells with Nucleospin RNA extraction Kit (Macherey-Nagel) and reverse transcribed using the High-Capacity cDNA Reverse Transcription Kit (Applied Biosystems, Thermo Fisher Scientific). qPCR assays were next performed using the fluorescent dye SYBR Green methodology and a CFX384 Real-Time PCR detector (Bio-Rad Laboratories, Marnes-la-Coquette, France), as previously described (18). The KiCqStart® SYBR® Green primers for human and mouse cDNA were provided by Sigma-Aldrich.…”

“…A systematic phenotypic and functional evaluation of the impact of different JAK inhibitors on the broad spectrum of activations states of macrophages is therefore mandatory. Moreover, there are conflicting results in the literature concerning in vivo effects of JAK inhibitors, as some studies report a switch from M1 to M2 activation after exposure to JAK3/JAK2 inhibitors such as tofacitinib (17) whereas a decrease of M2 polarization markers has been described after JAK2/1 inhibition by ruxolitinib (18). The precise impact of JAK inhibitors on a wide spectrum of activation states of macrophages is all the more important as the concept of a mutually exclusive M1/M2 polarization profile is more and more controverted, with a constant need of new relevant in vivo models to better approach this issue (19).…”

Janus kinase 2 (JAK2) inhibitors in the treatment of multiple myeloma: modulating the myeloma immune microenvironment

“…27 The same research group showed that ruxolitinib may provide anti-myeloma effects by inhibiting M2 polarisation of macrophages. 28 Importantly, in vitro data suggests that tofacitinib may be better at reversing the bone marrow microenvironmental effects seen in myeloma than ruxolitinib, indicating the importance exploring a range of JAK2 inhibitors in experimental models. 29 Ruxolitinib has been shown to upregulate CD38 expression and increased daratumumab activity in vitro, 30 identifying the need for future combination studies with anti-CD38 monoclonal antibodies such as daratumumab and isatuximab.…”