CXCR4 and CD74 together enhance cell survival in response to macrophage migration-inhibitory factor in chronic lymphocytic leukemia

Macrophage Migration Inhibitory Factor (MIF) and D-Dopachrome Tautomerase (DDT): Pathways to Tumorigenesis and Therapeutic Opportunities

Discovered as inflammatory cytokines, MIF and DDT exhibit widespread expression and have emerged as critical mediators in the response to infection, inflammation, and more recently, in cancer. In this comprehensive review, we provide details on their structures, binding partners, regulatory mechanisms, and roles in cancer. We also elaborate on their significant impact in driving tumorigenesis across various cancer types, supported by extensive in vitro, in vivo, bioinformatic, and clinical studies. To date, only a limited number of clinical trials have explored MIF as a therapeutic target in cancer patients, and DDT has not been evaluated. The ongoing pursuit of optimal strategies for targeting MIF and DDT highlights their potential as promising antitumor candidates. Dual inhibition of MIF and DDT may allow for the most effective suppression of canonical and non-canonical signaling pathways, warranting further investigations and clinical exploration.

CXCR4 overexpression in chronic lymphocytic leukemia associates with poorer prognosis: A prospective, single-center, observational study

Controversial data have been reported on the prognostic value of C-X-C motif chemokine receptor 4 (CXCR4) in chronic lymphocytic leukemia (CLL). This prospective, single-center, observational study aimed to evaluate the role of CXCR4 in the pathophysiology of CLL and its prognostic role. A total of 158 patients of CLL were enrolled, and CXCR4 expression on CLL cells was detected by flow cytometry (FCM) at initial diagnosis. The patients were divided into 2 groups according to the CXCR4 mean fluorescence intensity (MFI) median. Also, four patient specimens from the CXCR4low and CXCR4high groups were selected for RNASeq analysis. The progression-free survival (PFS) of CLL patients in the CXCR4high group was significantly shorter than the CXCR4low group, with a median follow-up time of 27 months (log-rank P < 0.001). Moreover, CXCR4 overexpression (MFI > 3376) was an independent marker of poor PFS in CLL patients (P < 0.001). Analysis of RNASeq results revealed that CXCR4 plays an important role in the migration of CLL. Collectively, CXCR4 expression levels on leukemia cells can be detected rapidly by FCM. CXCR4 overexpression was significantly associated with poorer prognosis in CLL patients within a shorter follow-up time.

Analysis of CD74 Occurrence in Oncogenic Fusion Proteins

CD74 is a type II cell surface receptor found to be highly expressed in several hematological and solid cancers, due to its ability to activate pathways associated with tumor cell survival and proliferation. Over the past 16 years, CD74 has emerged as a commonly detected fusion partner in multiple oncogenic fusion proteins. Studies have found CD74 fusion proteins in a range of cancers, including lung adenocarcinoma, inflammatory breast cancer, and pediatric acute lymphoblastic leukemia. To date, there are five known CD74 fusion proteins, CD74-ROS1, CD74-NTRK1, CD74-NRG1, CD74-NRG2α, and CD74-PDGFRB, with a total of 16 different variants, each with unique genetic signatures. Importantly, the occurrence of CD74 in the formation of fusion proteins has not been well explored despite the fact that ROS1 and NRG1 families utilize CD74 as the primary partner for the formation of oncogenic fusions. Fusion proteins known to be oncogenic drivers, including those of CD74, are typically detected and targeted after standard chemotherapeutic plans fail and the disease relapses. The analysis reported herein provides insights into the early intervention of CD74 fusions and highlights the need for improved routine assessment methods so that targeted therapies can be applied while they are most effective.