Liquid Biopsies - the Clinics and the Molecules.

Unlike bone marrow biopsies, liquid biopsies represent a gentler, more accessible, less painful, repeatable and more comprehensive approach to get biologically relevant information about the entire tumor but also about treatment response and level of minimal residual disease. This is all possible since peripheral blood contains not only circulating tumor cells but also many circulating molecules of nucleic acids (microRNA, cell-free DNA, long non-coding RNA etc.). Multiple myeloma is a genetically heterogeneous disease characterized by multifocal tumor deposits in the bone marrow but also focal lesions elsewhere. Single-site biopsy of the bone marrow creates a sampling bias that provides a limited molecular profile as the biopsy cannot capture all subclones. Moreover, during disease progression and treatment, molecular profile is changed and subclones of multiple myeloma cells resistant to treatment are formed. Likewise, various clones found in extramedullary sites that are not present in the bone marrow respond differently to treatment directly influencing survival of patients. Thus, liquid biopsies seem to be a relevant and necessary next step for diseases such as multiple myeloma.Key words: multiple myeloma - minimal residual disease - prognosis - liquid biopsies - cell-free DNA - non-coding RNA.

[Potential of Long Non- coding RNA Molecules in Diagnosis of Tumors]. / Potenciál dlouhých nekódujících molekul RNA v diagnostice nádorových onemocnení.

Long non-coding RNA molecules (lncRNA) are defined as molecules over 200 nucleotides long that are localized in the nucleus and cytoplasm of cells. Although function of most lnRNA is not known, it is obvious that they are involved in various biological processes. LncRNA play a key role in transcriptional as well as posttranscriptional regulatory pathways and are involved in important cell processes, such as proliferation, differentiation, apoptosis but also pathogenesis of various diseases. Their dysregulation is important in steps of tumor transformation. In this review, we will describe the nature, function and molecular basis of these molecules as well as their diagnostic potential. The main focus of this review is the usage of these molecules in the most often diagnosed tumors in the Czech population--colorectal carcinoma, breast and prostate carcinomas.

[Potential of Cell-free Circulating DNA in Diagnosis of Cancer]. / Potenciál volné cirkulující DNA v diagnostice nádorových onemocnení.

Circulating cell-free DNA (cf-DNA) is characterized as extracellular DNA that may be present in the blood of healthy individuals in low concentrations. Cf-DNA is released by apoptosis or necrosis into the bloodstream. Increased levels are found in pathological conditions, such as inflammation, autoimmune diseases, or stress. Significant increase of cf-DNA is particularly evident in patients with malignancies, especially in the advanced stages of the disease. In this case, the tumor specific cf-DNA is released by necrosis from the cells of primary tumor and metastases. Recently, many studies concentrate on the so-called 'liquid biopsies' that allow detection of circulating tumor cells and circulating nucleic acids from peripheral blood for tumor diagnostics. Quantitative methods and detection of genetic and epigenetic alternations of cf-DNA in patients with different malignancies have potential applications in molecular diagnosis, prognosis, monitoring of disease progression and response to treatment. This review focuses on potential utility of cf-DNA as a blood biomarker in selected solid tumors and hematologic malignancies.

[Cereblon -  a new target of therapy in the treatment of multiple myeloma]. / Cereblon -  nový terapeutický ciel v liecbe mnohopocetného myelómu.

Treatment of multiple myeloma (MM), currently an incurable disease, aims to achieve complete remission. Immunomodulatory drugs (IMiDs), represented by thalidomide, are one class of very effective drugs. However, the mechanism of IMiDs action is not yet completely understood. Recent research suggests that cereblon (CRBN) plays an important role in mediating anti-tumor effects of IMiDs; therefore, our review focuses on this protein. CRBN is a substrate receptor of Cul4- E3 ubiquitin ligase complex, and thus recognizes proteins destined for degradation. Bind-ing of CRBN and IMiDs inhibits function of the entire ubiquitin proteasome complex which partly explains their anti-tumor effects. In addition, a correlation between CRBN gene expression and effectiveness of treatment in MM patients treated with IMiDs was confirmed. These findings suggest that CRBN expression could possibly serve as a bio-marker to predict response to IMiD in MM patients.

Impact of anakinra treatment on cytokine and lymphocytes/ monocytes profile of an Erdheim-Chester patient.

BACKGROUND: Erdheim-Chester disease (ECD) is a rare non-Langerhans cells histiocytosis associated with intense immune activation. In our clinical center, an ECD patient was treated with anakinra, IL1RA (interleukin1 receptor antagonist), resulting in clinical improvement and major decrease of pathological fatigue. The aim of the study was to evaluate changes in cytokine profile and shift of immune cells estimated by flow cytometric analysis of ECD patient before, during initial stages of anakinra treatment as well as after treatment ceased in comparison to healthy donors. METHODS: Singleplex reactions of 19 individual cytokines from serum of ECD patient were measured by FACS array. Flow cytometric analyses were performed on peripheral blood cells. RESULTS: The most striking result is substantial decrease of IL6 immediately after anakinra treatment started suggesting a major role of IL1 pathway in ECD pathophysiology. As for flow cytometric analysis, increased number of CD16+ monocytes before treatment is a new finding. CONCLUSION: Our results suggest that IL6 may be a marker of early treatment response of ECD patients treated with anakinra.

[Cytokine profiles of multiple myeloma and Waldenström macroglobulinemia]. / Cytokinové profily mnohocetného myelomu a Waldenströmovy makroglobulinemie.

Multiple myeloma (MM) and Waldenström macroglobulinemia (WM) are malignant disorders of B lymphocytes. These diseases are characterized by monoclonal immunoglobulin production and bone marrow infiltration, which further lead to disease manifestation mainly via osteolytic lesions and disruption of hematopoiesis. The bone marrow microenvironment plays a crucial role in pathogenesis of both of these diseases, as it is well known that interaction between malignant cells and bone marrow cells facilitates both survival and growth of these tumor cells. The interactions are mediated by several different factors, including cytokines. Their production leads to tumor cell growth, proliferation and survival contributing to pathogenesis of MM and WM. In this review, we focus on function of the most important cytokines in both these diseases.

[Cyclins D in regulation and dysregulation of the cell cycle in multiple myeloma]. / Cykliny D v regulaci a dysregulaci bunecného cyklu u mnohocetného myelomu.

Multiple myeloma is the second most common hematooncological disease characterized by clonal proliferation of plasma cells and monoclonal immunoglobulin production. It is a heterogenous disease; however, dysregulation of cyclins D seems to be an early unifying pathogenic event in multiple myeloma. In almost all patients, there is increased expression level of at least one of the cyclins D. Nevertheless, the mechanism of this increase is unknown in many cases. Next to wellknown roles of cyclins D in the cell cycle, they have many other functions contributing to tumor cell progression. Cyclins D are prognostic markers and are also used for subclassification of multiple myeloma. In this review, we focus on significance of cyclins D in multiple myeloma.

[Degradation of proteins by ubiquitin proteasome pathway]. / Degradace proteinu ubikvitinproteazomovou dráhou.

All intracellular and some extracellular proteins are continually degraded and replaced by synthesis of new proteins. Both these processes need to stay in equilibrium since their balance may lead to emergence of diseases. Cells contain many proteolytic systems that ensure highly specific and controlled degradation of proteins. One of these systems is the proteasome, a very complex molecular engine allowing degradation of proteins conjugated to ubiquitin. Since the first isolation of proteasome in 1968, many details about its function have been uncovered. In 2004, Nobel Prize for chemistry was awarded for these discoveries. In our review article, we aimed to summarize information about the mechanism of highly selective degradation of proteins by the ubiquitin proteasome pathway. Individual parts of the paper summarize current knowledge about highly selective degradation of proteins by the ubiquitin proteasome system, mechanisms of protein degradation regulation and bio-logical effects of proteasome inhibitors.

[Proteasome inhibitors in treatment of multiple myeloma]. / Inhibitory proteazomu v lécbe mnohocetného myelomu.

Multiple myeloma, a plasma cell malignancy, still remains a hard-to-treat hematological disease that desperately needs new therapy targeting plasmocytes but also the bone marrow microenvironment. Clonal plasmocytes are characterized by increased regulation of ubiquitin-proteasome pathway which augments their sensitivity to proteasome inhibitors. Treatment strategies based on proteasome inhibitors belong to the era of new drugs, and they have become increasingly important for treatment of multiple myeloma in recent years. Bortezomib became the first proteasome inhibitor approved for the treatment of multiple myeloma and showed remarkable anti-myeloma activity. However, despite its high efficiency, a large proportion of patients have became bortezomib resistant. The second generation of proteasome inhibitors - carfilzomib, marizomib and MLN9708 - were developed in an effort to overcome bortezomib-resistance and find proteasome inhibitors with a better toxic profile. These drugs brought a chance that multiple myeloma would become a chronic disease.