We investigated the relevance of p53 deletions to the clinical outcome of patients with multiple myeloma (MM) treated with high-dose chemotherapy and autologous stem cell transplantation. Hemizygous p53 gene deletions were detected by fluorescence in situ hybridization in 10 of 105 (9.5%) patients studied. p53 deletions were associated with higher serum calcium (P = .0062) and creatinine (P = .013) levels, but there were no association with patient age, gender, β2-microglobulin, C-reactive protein, hemoglobin, albumin or bone lytic lesions, or immunoglobulin isotype. There were no associations of p53 deletions with 13q deletions or translocations t(11;14) or t(4;14). Patients with p53 deletions had significantly shorter progression-free (median, 7.9 versus 25.7 months, P = .0324) and overall survival (median, 14.7 versus 48.1 months, P = .0008) than patients without a p53 deletion. A multivariate analysis confirmed p53 deletion was an independent prognostic factor predicting shortened progression-free (P = .0009) or overall survival (P = .0002) in patients with MM after high-dose chemotherapy and autologous stem cell transplantation. (Blood. 2005;105:358-360)

Summary: The frequency and prognostic relevance of translocations t(11;14) and t(4;14), the most common translocations involving the immunoglobulin heavy chain (IgH) gene in multiple myeloma (MM), were investigated in 128 patients treated with intensive chemotherapy and autologous stem cell transplant. Myeloma cells were identified by cytoplasmic light chain immunofluorescence combined with fluorescence in situ hybridization (cIg‐FISH) for detection of translocations t(11;14) and t(4;14). Overall, t(11;14) was detected in 16 of 125 (12·8%) and t(4;14) in 15 of 120 (12·5%) patients. Progression‐free and overall survivals were similar for patients with or without t(11;14). However, patients with t(4;14) had significantly shorter progression‐free (median 9·9 months vs. 25·8 months; P = 0·0003) and overall survivals (median 18·3 months vs. 48·1 months; P < 0·0001) than patients without t(4;14). The t(4;14) was associated with IgA and t(11;14) with light chain MM. There was no association between the t(11;14) or t(4;14) and other biological parameters including age, gender, haemoglobin, β‐2 microglobulin, C‐reactive protein, calcium, creatinine, albumin, or the percentage of bone marrow plasma cells. Multivariate analysis identified t(4;14) as the only adverse prognostic factor for both progression‐free survival and overall survival. Our results indicate that the t(4;14) detected by cIg‐FISH is associated with a poor prognosis in MM patients receiving intensive chemotherapy and autotransplant.

In the era of new and mostly effective therapeutic protocols, multiple myeloma still tends to be a hard-to-treat hematologic cancer. This hallmark of the disease is in fact a sequel to drug resistant phenotypes persisting initially or emerging in the course of treatment. Furthermore, the heterogeneous nature of multiple myeloma makes treating patients with the same drug challenging because finding a drugable oncogenic process common to all patients is not yet feasible, while our current knowledge of genetic/epigenetic basis of multiple myeloma pathogenesis is outstanding. Nonetheless, bone marrow microenvironment components are well known as playing critical roles in myeloma tumor cell survival and environment-mediated drug resistance happening most possibly in all myeloma patients. Generally speaking, however; real mechanisms underlying drug resistance in multiple myeloma are not completely understood. The present review will discuss the latest findings and concepts in this regard. It reviews the association of important chromosomal translocations, oncogenes (e.g. TP53) mutations and deranged signaling pathways (e.g. NFκB) with drug response in clinical and experimental investigations. It will also highlight how bone marrow microenvironment signals (Wnt, Notch) and myeloma cancer stem cells could contribute to drug resistance in multiple myeloma.

CD47, or integrin-associated protein, is a cell surface ligand expressed in low levels by nearly all cells of the body. It plays an integral role in various immune responses as well as autoimmunity, by sending a potent “don’t eat me” signal to prevent phagocytosis. A growing body of evidence demonstrates that CD47 is overexpressed in various hematological malignancies and its interaction with SIRPα on the phagocytic cells prevents phagocytosis of cancer cells. Additionally, it is expressed by different cell types in the tumor microenvironment and is required for establishing tumor metastasis. Overexpression of CD47 is thus often associated with poor clinical outcomes. CD47 has emerged as a potential therapeutic target and is being investigated in various preclinical studies as well as clinical trials to prove its safety and efficacy in treating hematological neoplasms. This review focuses on different therapeutic mechanisms to target CD47, either alone or in combination with other cell surface markers, and its pivotal role in impairing tumor growth and metastatic spread of various types of hematological malignancies.