Background. Nowadays, hematology is a dynamically developing science due to the in-depth study of the molecular mechanisms of a particular disease. A better understanding of oncohematological diseases biology makes it possible to synthesize new targeted drugs, which have a favorable therapeutic effect. In particular, in multiple myeloma, after the introduction of proteasome inhibitors and immunomodulatory drugs into clinical practice, an improvement in overall survival was observed. However, characteristics of the mechanisms of transformation normal plasma cells into malignant ones are still difficult; therefore, the study of the pathobiological basis of multiple myeloma is currently an urgent task.The objective: to evaluate the possible influence of MAGE-C1 gene expression and the presence of mage-c1 protein in patients with newly diagnosed multiple myeloma on the anti-tumor response after bortezomib-containing therapy.Materials and methods. A prospective study included 33 multiple myeloma patients. The diagnosis was established according to International Myeloma Working Group criteria (IMWG, 2014). In 32 patients the induction therapy included bortezomib-containing courses, in one patient lenalidomide was included in the first-line regimens. The MAGE-C1 gene expression by real-time polymerase chain reaction and mage-c1 protein by immunohistochemistry in plasma cells bone marrow, were determined for all patients at the debut of multiple myeloma. As a control group was examined the bone marrow material of healthy donors.Results. When assessment the statistical relationship between the expression of MAGE-C1 gene and mage-c1 protein, it was found that there was no high expression of mage-c1 protein at low values of MAGE-C1 gene expression. At the same time, high expression of the gene was always associated with protein expression above normal values. The analysis aimed at finding the relationship between MAGE-C1 gene and mage-c1 protein detection and the degree of antitumor response after 6 courses of induction therapy showed that high expression of the studied parameters was associated with a worse response to bortezomib-containing treatment.Conclusion. We confirmed that the results of the two methods were comparable. Single factor analysis showed that patients with decreased MAGE-C1 gene and mage-c1 protein expression levels achieved a significantly higher antitumor response to bortezomib-containing regimens, while high expression was accompanied by refractoriness to bortezomib.

Introduction. Autologous haematopoietic stem cell transplantation (auto-HSCT) is a highly effective treatment for multiple myeloma (MM). Auto-HSCT allows a signifi cant improvement of haematological response leading to higher overall survival and quality of life in MM patients. Nonetheless, the majority of patients develop relapse.Aim — a comparison of clinical MM relapses developing at variant terms after auto-HSCT.Patients and methods. A retrospective study enrolled 65 MM patients aged between 39 and 64 years. All patients had auto-HSCT during 2009–2019, all had achieved complete response (CR) or very good partial response (VGPR) and all since developed immunochemical MM relapse in laboratory evidence. Patients were divided in two cohorts by relapse term, the early (within 12 months of auto-HSCT) and late relapse.Results. Early immunochemical relapse was diagnosed in 13 (20 %), late relapse — in 52 (80 %) patients. The dependence between relapse term and depth of post-auto-HSCT antitumour response has been determined. The proportion of CR patients was signifi cantly higher in late than in early relapse (55.8 vs. 23 %). In follow-up, 60 patients (92.3 %) were initiated on antirelapse therapy, all early relapse and 90.3 % late relapse patients. On day +100 of auto-HSCT, CR patients had later relapse vs. VGPR individuals (median 24 vs. 19.9 months, p = 0.08) with signifi cantly weaker paraprotein secretion resembling the clinical course of monoclonal gammopathy of unclear signifi cance (MGUS).Conclusion. Auto-HSCT allows long-term control of the disease. A signifi cant prognostic factor is antitumour response on +100 day of auto-HSCT. Patients attaining CR have later relapse progressing in a MGUS-like manner. Patients with late indolent relapse can be managed long-term without antitumour therapy.

Group of tumor-associated antigens, which is normally expressed in placental cells and testicular germ cells, is called cancer-testis antigens. To date, more than 40 gene families have been identified that encode cancer-testis antigens, and their expression has been studied in many types of malignant diseases. It is assumed that the expression of cancer-testis antigens can contribute to the development of the tumor transformation process, including hematological diseases. Of particular interest in the pathogenesis of multiple myeloma is the MAGE-C1/CT7 antigen, the expression of which is most often detected in this case. According to data published by various authors, the expression of MAGEC1 in multiple myeloma can be considered as an additional marker of a poor disease prognosis, represent the effectiveness of chemotherapy approaches, and, possibly, be an earlier predictor of relapse or progression.

The relationship between the type of antitumor response to induction therapy in patients with multiple myeloma (MM) and/or monoclonal gammopathy of undetermined significance (MGUS) and the level of c-MYC gene expression at the moment of disease diagnosis is studied. The expression of c-MYC in bone marrow cells was evaluated by multiplex RT-PCR. The mean levels of c-MYC gene expression in CD138(+) cells of patients with MM/MGOO are higher than in donors (p = 0.011). Relationship between the depth of antitumor response and level of C-myc expression in CD138(+) cells is detected.