Swim bladder as a primary site of mycobacterial infection in Nothobranchius 'belly sliders'.

The swim bladder inflates early after fish hatching via its interconnection with the digestive tract (ductus pneumaticus). This interconnection may serve as a portal to foreign particles, including bacteria, causing deficiencies in primary swim bladder inflation. We histologically examined 134 African annual killifish (genus Nothobranchius) with secondary loss of swim bladder function ('belly sliders'). We demonstrate that these fish lost the ability of air regulation in their swim bladders likely due to Mycobacterium spp. infection at an individual-specific age. Nearly all examined belly sliders had thickened swim bladder walls, and their swim bladder was filled with material containing mycobacteria, cell debris, young monocytic cells and phagocyting macrophages. Mycobacterial infection was restricted to the swim bladder in juveniles, where mycobacteria likely enter the host through the ductus pneumaticus. Infection in adults was systemic and mycobacteria were present in all examined organs. Presence of mycobacteria in the epithelial lining and submucosal layers of the digestive tract of adults suggests that it may also serve as the entrance site of infection. We suspect 2 sources of Mycobacterium contamination: dietary (with bloodworms) and/or contaminated hatching substrate. These sources of contamination may be eliminated by use of laboratory dry feed and egg disinfection prior to hatching.

Effective Immunotherapy of Glioblastoma in an Adolescent with Constitutional Mismatch Repair-Deficiency Syndrome.

BACKGROUND: Individuals with constitutional mismatch repair-deficiency syndrome (CMMR-D) are characterised by early occurrence of colon cancer, haematological malignancies, and brain tumors (malignant gliomas, high-grade gliomas) in childhood, adolescence, and early adulthood. High mutational tumor burden is typical of glioblastoma in CMMR-D patients and could be a reason why this type of glioblastoma responds well to immunotherapies, including those that employ checkpoint inhibitors. OBSERVATION: We describe a case of an adolescent with CMMR-D that had been genetically proven by whole exome sequencing (c.2T>A/p.M1K and c.2521delT/p.W841fs PMS2 gene mutation). The patient presented successively with colon cancer and glioblastoma with a high mutational burden. The individualized glioblastoma therapy was based on the biological tumor profile and included immunotherapy with a combination of vaccination with autologous dendritic cells producing IL-12 and nivolumab, in addition to radiotherapy with metronomic temozolomide. The patient is still alive 21 months after the initial glioblastoma diagnosis and shows a complete therapeutic response documented by repeated magnetic resonance examinations. CONCLUSION: Individuals with CMMR-D should be regularly examined using established algorithms. Whole body magnetic resonance imaging can play a key role, because it enables the early diagnosis of malignancy during the asymptomatic period. Malignancies in CMMR-D patients usually exhibit a hypermutated genotype and respond to immunotherapy. Conventional glioblastoma therapy is only palliative. Patients can benefit from an individualized therapeutic plan based on the tumor biological profile. Extensive molecular analysis of the tumor tissue is necessary. Key words hereditary cancer predisposition syndromes - glioblastoma - whole exome sequencing - immunotherapy - vaccines - checkpoint inhibitors This study was supported by the research project of the Czech Ministry of Health AZV 16-33209A (Next generation sequencing and express profiling as diagnostic tools for personalized therapeutic plans in children with solid tumors). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 26. 9. 2018 Accepted: 18. 11. 2018.

Effect of Tumor Size and p16 Status on Treatment Outcomes - Achievement of Complete Remission in Prospectively Followed Patients with Oropharyngeal Tumors.

BACKGROUND: Oropharyngeal squamous cell tumors associated with human papillomavirus infection (p16 positive tumors) have better prognosis than p16 negative tumors regardless of the more advanced stage of the disease. Tumor volume (GTVt+n) is generally an important factor affecting treatment results of ionizing radiation. The aim of this prospective non-randomized study is to evaluate the effect of tumor volume on the (chemo)radiation treatment results in a group of patients with p16 negative and p16 positive oropharyngeal tumors. PATIENTS AND METHODS: Patients with confirmed squamous cell tumor of the oropharynx of stages III and IV, according to the 7th version of the TNM (tumor-nodes-metastases) classification, were eligible for this study. The main exclusion criteria were palliative treatment, neoadjuvant chemotherapy or planned concomitant therapy with cetuximab. Patients were treated according to standardized protocols with curative intent. Primary tumor volume (GTVt) and involved nodes volume (GTVn) were obtained from radiotherapy planning system for further statistical analysis. The differences in tumor volumes between the groups according to p16 expression were assessed with subsequent testing of probability to achieve complete remission (CR) of the disease in both groups. RESULTS: In total, 49 patients - 84% men, median age 60.5 years, 25 (51%) patients p16 positive, 40 (82%) underwent concomitant chemoradiotherapy. Median of GTVt in the whole patients group is 40.2 ccm, GTVn 11.78 ccm and median volume of the whole tumor burden (GTVt+n) 70.21 ccm (range 11.05-249). Median of GTVn was greater in the p16 positive cohort (p = 0.041). In the entire group, the median time to reach CR was 91 days (95% CI 86-107 days) from the end of radiotherapy. In the group of p16 negative patients, 14 achieved CR (61%) out of 23 patients, in p16 positive group 20 (80%) out of 25 patients (p = 0.111). P16 negative patients had a longer time to CR (p = 0.196, HR 1.58, 95% CI 0.79-3.18). None of the independently assessed volumetric parameters of the tumor (GTVt, GTVn, GTVt+n) affected CR in the p16 positive patients group, while there was a significant impact of the whole tumor burden (GTVt+n) in the p16 negative cohort (median 58.1 ccm in CR patients vs. 101.9 ccm, p = 0.018). CONCLUSION: We have showed less GTVt+n dependence to achieve CR in p16 positive tumors in comparison with p16 negative tumors. Thus, p16 positive oropharyngeal squamous cell cancers should not be withdrawn from the curative treatment intent based on the greater GTVt+n. Key words oropharyngeal neoplasms - p16 status - treatment outcome - tumor burden - complete remission This work was supported by grant of the Ministry of Health of the Czech Republic AZV 15-31627A and by grant of the Ministry of Health of the Czech Republic - Conceptual development of a research organization (MMCI 00209805). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 2. 11. 2018 Accepted: 11. 11. 2018.

[Usage of Cerebrospinal Fluid for microRNA Analysis]. / Vyuzití mozkomísního moku pro analýzu mikroRNA.

BACKGROUNDS: Deregulated levels of miRNAs, short noncoding RNAs associated with pathogenesis of many diseases, have been observed in cerebrospinal fluid (CSF). Therefore, the analysis of CSF miRNAs in patients affected by tumors of central nervous system (CNS) might help to develop new diagnostic platform enabling more precise diagnosis. Thus, in our study we tried to optimize methodical approaches to be used for miRNA detection as RNA isolation and selection of suitable technology for global high-throughput miRNA profiling. MATERIAL AND METHODS: In the optimization phase of RNA isolation from CSF, various commercially available kits with different protocol modifications were compared. Two quantitative polymerase chain reaction panels and Next Generation Sequencing method were tested for selection of the most suitable method for miRNA comprehensive profiling. RESULTS: The Urine miRNA Purification kit (Norgen) and Next Generation Sequencing was selected as the most suitable kit for RNA extraction from CSF and method for miRNA comprehensive profiling, resp. CONCLUSION: We established a protocol for RNA isolation and miRNA comprehensive profiling in CSF clinical specimens.Key words: brain neoplasm - cerebrospinal fluid - microRNA The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. This study was supported by Ministry of Health of the Czech Republic, grant No. 15-34553A. All rights reserved.Submitted: 19. 3. 2018Accepted: 10. 4. 2018.

[Pilot Study on MicroRNAs as Biomarkers of Response to Sunitinib Treatment in Patients with Metastatic Renall Cell Carcinoma]. / MikroRNA jako biomarkery odpovedi na lécbu sunitinibem u pacientu s metastatickým karcinomem ledvin - pilotní studie.

BACKGROUND: Renal cell carcinoma (RCC) accounts for 2-3% of all malignant tumours. Metastatic RCC (mRCC) is commonly treated with tyrosine kinase inhibitors (TKI). Effective TKIs administration can be achieved only by accurate prediction of therapeutical response. Therefore, the aim of this study was to analyse papers concerning predictive potential of microRNA (miRNA). MATERIAL AND METHODS: We chose seven candidate miRNAs and analysed their expression on 44 patients divided into cohort with poor and good response to sunitinib treatment. Patients were divided into two groups according to progression-free survival. RNA from tissue samples was isolated and expression of selected miRNAs was measured using quantitative PCR with miRNA-specific TaqMan probes. RESULTS: We successfully validated two miRNAs to be differentially expressed in responding and non-responding patients to sunitinib treatment. Other analysed miRNAs have not shown predictive potential. CONCLUSION: From miRNAs studied so far, two miRNAs had predictive value according to present study.Key words: microRNA - renal cell carcinoma - sunitib The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Supported by Ministry of Health of the Czech Republic, grant No. 15-34678A. All rights reserved.Submitted: 19. 3. 2018Accepted: 20. 3. 2018.

[Dysregulation of Long Non-coding RNAs in Glioblastoma Multiforme and Their Study Through Use of Modern Molecular-Genetic Approaches]. / Dysregulace dlouhých nekódujících RNA u multiformního glioblastomu a jejich studium s vyuzitím moderních molekulárne-genetických prístupu.

BACKGROUND: Glioblastoma (GBM) is the most frequent primary brain tumor characterized by an unfavourable prognosis despite multimodal therapy. Therefore, a lot of efforts and financial resources are dedicated to the research of new therapeutic targets and prognostic or predictive biomarkers. Long non-coding RNAs (lncRNAs) are regulators of gene expression which play a significant role in GBM pathology and, thus, present promising candidates. MATERIAL AND METHODS: Our study included 14 patients with GBM and 8 patients with intractable epilepsy from whom we acquired brain tissues during surgical intervention. Ribosomal RNA depleted RNA was used for sequencing by NextSeq 500 instrument (Illumina). Statistical analysis evaluated 24,087 protein-coding and 8,414 non-coding RNAs and their sequential variants with non-zero reads per kilobase per million mapped reads (RPKM) at least in one sample. CLC Genomic Workbench was used for the alignment and target counts. Targeted downregulation of up-regulated ZFAS1, one of the identified lncRNA, level has been carried out by the transient transfection of specific small interfering RNA (siRNA) in GBM stable cell lines (A172, U87MG, T98G). The success of transfection and viability were analyzed in vitro using quantitative real time polymerase chain reaction and MTT assay, resp. RESULTS: Statistical analysis has revealed 274 (p < 0.01) dysregulated lncRNAs in GBMs in comparison with non-tumor brain tissues. Moreover, the results have showed 489 dysregulated mRNAs (p < 0.0001) and 26 mRNAs (p < 0.000001). Transfection of ZFAS1 inhibitor led to successful downregulation of ZFAS1 expression level, although it did not have a significant effect on proliferation of GBM cells. CONCLUSION: We described a significant dysregulation of lncRNAs and mRNAs in GBM tissue in comparison with non-tumor tissue. We also succesfully decreased expression level of ZFAS1, which in turn, however, had no impact on the viability of GBM cell lines.Key words: glioblastoma - long non-coding RNA - next-generation sequencing The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. This tudy was supported by Ministry of Health of the Czech Republic, grant No. 15-33158A. All rights reserved.Submitted: 19. 3. 2018Accepted: 10. 4. 2018.

[MicroRNAs in Prediction of Response to Radiotherapy in Head and Neck Cancer Patients - Pilot Study]. / MikroRNA v predikci odpovedi na radioterapii u pacientu s nádory hlavy a krku - pilotní studie.

BACKGROUND: Radiotherapy plays a key role in the treatment of squamous cell head and neck cancers (HNSCC). The effectivity of radiation therapy is often limited by radioresistance of these tumours. microRNAs (miRNAs) are endogenous, evolutionary conserved, small non-coding RNAs involved in regulation of cellular processes associated with radioresistance. The objective of this study was to identify miRNA profile enabling to predict the radiation treatment outcomes in HNSCC patients. MATERIAL AND METHODS: The retrospective study included HNSCC patients who underwent a definitive radiotherapy. Patients were divided into two groups according to loco-regional control (LRC) as follows - short LRC (n = 22; median 5.1 months (min. 1.3, max, 18.6)) vs. long LRC (n = 21; 60.4 (min. 46.8, max. 98.8)) group. Global miRNA expression profiles were obtained by use of Affymetrix microarray technology (GeneChip miRNA 4.0 Array). RESULTS: We identified 24 miRNAs to be significantly associated with LRC (p < 0.05), all of these miRNAs were upregulated in patients with short LRC. Out of these miRNAs, 12 miRNAs with p < 0.025 and 4 miRNAs with p < 0.01 have been identified. CONCLUSION: miRNAs seems to be promising as potential biomarkers predicting radiotherapy treatment outcomes in patients with HNSCC.Key words: microRNAs - radiotherapy - head and neck cancer The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Supported by Ministry of Health of the Czech Republic, grant No. 15-31627A. All rights reserved.Submitted: 19. 3. 2018Accepted: 20. 3. 2018.

[Urinary MicroRNAs as Potential Biomarkers of Bladder Cancer]. / Mocové mikroRNA jako potenciální biomarkery karcinomu mocového mechýre.

BACKGROUND: Currently, there are no urinary-based tumour markers with sufficient sensitivity and specificity to replace cystoscopy in the detection of bladder cancer (BCA). Urinary microRNAs are emerging as clinically useful class of biomarkers for early and non-invasive detection of urologic malignancies. PATIENTS AND METHODS: In this study, 155 patients with BCA and 83 healthy controls were enrolled. Expression profiles of urinary miRNAs were obtained using Affymetrix miRNA microarrays and candidate miRNAs further validated in independent cohort using specific TaqMan assays and quantitative real-time polymerase chain reaction method. RESULTS: Whole-genome profiling identified miRNA signature with significantly different concentrations in urine of BCA compared to controls (p < 0.01). In the independent validation phase of the study, three miRNAs were confirmed to have significantly higher levels in urine of patients with BCA in comparison with control groups (p < 0.0001). In addition, we observed significant decrease in two miRNAs (p < 0.01) concentrations in the urinary samples collected 3 months after surgery compared to pre-operative samples. CONCLUSION: We identified and validated miRNAs to have significantly higher concentrations in urine of patients with BCA in comparison with controls. Our data have shown that urinary miRNAs could serve as sensitive and specific biomarkers enabling non-invasive detection of BCA.Key words: urinary microRNAs - biomarkers - bladder cancer The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. This study was supported by Ministry of Health of the Czech Republic, grant No. 15-31071A. All rights reserved.Submitted: 19. 3. 2018Accepted: 20. 3. 2018.

[MicroRNA Analysis for Extramedullary Multiple Myeloma Relapse]. / Analýza mikroRNA u extramedulárního relapsu mnohocetného myelomu.

INTRODUCTION AND AIMS: Multiple myeloma (MM) is the second most common hematooncological disease. Patient survival has been greatly improved by the introduction of new drugs into clinical practice, but survival is negatively affected by the so-called extramedullary relapse (EM), caused by the loss of plasma cell dependence on the bone marrow microenvironment and their migration out of the bone marrow. The nature and causes of this process are currently unclear. MicroRNAs (miRNAs) are short, non-coding RNA molecules involved in many physiological and pathological processes. Their significance in the pathogenesis of MM has been demonstrated by several studies. We assume that they are also involved in the development of the EM. The aim of this study was to analyze different miRNA expression between MM and EM patients. MATERIAL AND METHODS: Using next generation sequencing, we analyzed 39 samples of bone marrow cells from MM patients at diagnosis and 9 bone marrow plasma samples of EM patients. RESULTS: In total, 2,278 miRNA were sequenced, but only 658 miRNAs were analyzed as they were expressed in all samples and had at least 20 reads. Expression data were generated using the Chimira tool from fastq data. All sequences were mapped using miRBase v20. Further analyses were performed using the R/Bioconductor package. The Bayesian procedure was used for normalization of expression. P values were adjusted using the Benjamini-Hochberg method. Analysis found 10 miRNA (p < 0.0005) that are statistically significantly expressed in EM vs. MM patients - these are miR-26a-5p, miR-26b-5p, miR-30e-5p, miR-424-3p, miR-503-5p, miR-767-5p, miR-105-5p, miR-5695-5p, miR-450b-5p and miR-92b-3p. These miRNAs will be further verified by qPCR method on a larger set of MM and EM patients. CONCLUSION: Our pilot study has shown that there are differentially expressed miRNAs between MM and EM patients.Key words: multiple myeloma - microRNA - carcinogenesis - next generation sequencing The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papersThis work was supported by grant MZ CR AZV 17- 29343A. Submitted: 17. 3. 2018Accepted: 20. 3. 2018.

[Current Possibilities for Predicting Responses to EGFR Blockade in Metastatic Colorectal Cancer]. / Soucasné moznosti predikce odpovedi na cílenou anti-EGFR lécbu metastatického kolorektálního karcinomu.

BACKGROUND: The combination of modern systemic chemotherapy and anti-EGFR monoclonal antibodies improves overall survival and quality of life for patients with metastatic colorecal cancer. By contrast, the addition of anti-EGFR therapy to the treatment regime of resistant patients may lead to worse progression-free survival and overall survival. Therefore, identifying sensitive and resistant patients prior to targeted therapy of metastatic colorecal cancer is a key point during the initial decision making process. Previous research shows that primary resistance to EGFR blockade is in most cases caused by constitutive activation of signaling pathways downstream of EGFR. Of all relevant factors (mutation of KRAS, NRAS, BRAF, and PIK3CA oncogenes, inactivation of tumor suppressors PTEN and TP53, amplification of EGFR and HER2, and expression of epiregulin and amphiregulin, mikroRNA miR-31-3p, and miR-31-5p), only evaluation of KRAS and NRAS mutations has entered routine clinical practice. The role of the other markers still needs to be validated. The ongoing benefit of anti-EGFR therapy could be indicated by specific clinical parameters measured after the initiation of targeted therapy, including early tumor shrinkage, the deepness of the response, or hypomagnesemia. The accuracy of predictive dia-gnostic tools could be also increased by examining a combination of predictive markers using next generation sequencing methods. However, unjustified investigation of many molecular markers should be resisted as this may complicate interpretation of the results, particularly in terms of their specific clinical relevance. AIM: The aim of this review is to describe current possibilities with respect to predicting responses to EGFR blockade in the context of the EGFR pathway, and the utilization of such results in routine clinical practice.

[Involvement of PIWI-interacting RNAs in Cancerogenesis via the Regulation of Gene Expression]. / Zapojení PIWI-interagujících RNA do procesu kancerogeneze prostrednictvím regulace genové exprese.

BACKGROUND: In the past few years, a number of studies have suggested that small non-coding RNAs could be promising diagnostic, prognostic and predictive biomarkers in oncology. Recently, small RNAs interacting with PIWI proteins (piRNAs) have been described. These small RNAs regulate gene expression at transcriptional and post-transcriptional levels; however, they appear to be specifically involved in silencing the transposable elements LINE and SINE and are thus considered to contribute to genomic stability. Furthermore, piRNAs participate also in other important biological processes, such as gametogenesis, chromosome segregation, and stem cell self-renewal. Although their expression was first noted in germ line cells, they are now known to be present in all tissue types and their expression is highly tissue-specific. In addition, piRNA expression is dysregulated in tumor tissues. Nevertheless, the exact function of these molecules in cancerogenesis is not known. Recently, free circulating piRNAs were reported to be stably present in body fluids, suggesting that they could serve as promising noninvasive biomarkers to enable early diagnosis, therapy response prediction, and accurate prognosis prediction of cancer patients. AIM: The aim of this review is to summarize current knowledge about piRNA biogenesis and their functions in the regulation of gene expression and transposons silencing. In addition, the review focuses on piRNAs that show dysregulated expression in different types of cancers and that could serve as potential diagnostic biomarkers and/or therapeutic targets.Key words: PIWI-interacting RNAs - piRNA - biogenesis - cancer - transposon silencing - biomarkers - therapeutic targetsThe results of this research have been acquired within CEITEC 2020 (LQ1601) project with financial contribution made by the Ministry of Education, Youths and Sports of the Czech Republic within special support paid from the National Programme for Sustainability II funds.The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study.The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 23. 11. 2016Accepted: 5. 12. 2016.

[The Relevance of MicroRNAs in Glioblastoma Stem Cells]. / Význam mikroRNA u glioblastomových kmenových bunek.

Glioblastoma multiforme is the most common intracranial malignity of astrocyte origin in adults. Despite complex therapy consisting of maximal surgical resection, adjuvant concomitant chemoradiotherapy with temozolomide followed by temozolomide in monotherapy, the median of survival ranges between 12 and 15 months from dia-gnosis. This infaust prognosis is very often caused by both impossibility of achieving of sufficient radical surgical resection and tumor resistance to adjuvant therapy, which relates to the presence of glioblastoma stem cells. Similarly to normal stem cells, glioblastoma stem cells are capable of self -renewal, differentiation, and unlimited slow proliferation. Their resistance to conventional therapy is also due to higher expressions of DNA repair enzymes, antiapoptotic factors and multidrug transporters. Therefore, targeting these unique properties could be a novel promising therapeutic approach leading to more effective therapy and better prognosis of glioblastoma multiforme patients. One of the approaches how to successfully regulate above -mentioned properties is targeted regulation of microRNAs (miRNAs). These small noncoding RNA molecules posttranscriptionally regulate expression of more than 2/ 3 of all human genes that are also involved in stem cell associated signaling pathways. Moreover, deregulated expression of some miRNAs has been observed in many cancers, including glioblastoma multiforme.

[Immunotherapy for the Prevention and Treatment of Breast Cancer]. / Imunoterapie v prevenci a lécbe karcinomu prsu.

The immune system is believed to play a dual role in carcinogenesis. On one hand, it could prompt tumorigenesis and cancer progression, on the other hand, it has the capacity to eradicate tumor cells. There has been an evidence of natural immunogenicity in breast cancer and we have also witnessed several attempts to stimulate non-specific antitumor immune response (Coleys toxin, BCG vaccine etc.). New technologies and further knowledge of molecular basis of immune system and its function encouraged the development of effective immunotherapy capable of inducing a solid antitumor activity. These agents appear promissing in the prevention and therapy of breast carcinoma as well. The assumption is based on the results of several antitumor vaccine trials targeted against HER2, MUC1, CEA and mammaglobin-A, as well as immune checkpoint inhibitors (e.g. CTLA-4, PD-1/ PD-L1, LAG3). With regards to different mech-anisms of action of these agents, their combination might bring about synergistic antitumor effects. Nonetheless, monoclonal antibodies and cytostatic agents already approved for breast cancer treatment might be exploited for their immunomodulation effect as well. This article addresses prospects for immunotherapy of breast carcinoma in detail.

[The role of MicroRNAs in the pathophysiology of neuroblastoma and their possible use in diagnosis, prognosis and therapy]. / Role mikroRNA v patofyziologii neuroblastomu a moznosti jejich vyuzití pro dia-gnostiku, odhad prognózy a terapii.

Neuroblastoma (NBL) is a typical childhood tumor developing from the precursor cells of the sympathetic nervous tissue and accounting for approximately 7% of total malignancies in pediatrics and 15% of deaths associated with this malignancy. MicroRNAs (miRNAs) are small single-stranded RNA molecules that are involved in posttranscriptional regulation of gene expression, whereas the pathophysiology of neuroblastoma tumor growth involves both upregulation of the protooncogenic miRNAs as well as downregulation of the tumor-suppresor ones. Comparison of the expression profiles of miRNAs in specific subtypes of neuroblastoma seems to be a useful tool adding to the classification of the diseases, and the assessment of the levels of specific miRNAs may be useful for estimation of the individual treatment response as well as prognosis of the patient. This paper provides the basic review of the studies focused on the role of miRNAs in pathogenesis of neuroblastoma and provides a survey of current/ possible use of these miRNAs in diagnostics, therapy or prognosis estimation in the neuroblastoma patients.

[The role of microRNAs in molecular pathology of esophageal cancer and their potential usage in clinical oncology]. / Role mikroRNA v molekulární patologii karcinomu jícnu a jejich potenciální vyuzití v klinické onkologii.

MicroRNAs are an abundant class of noncoding RNAs (approx. 18- 25 nucleotides in length) that suppress translation through binding to their target mRNAs, eventually leading to mRNAs degradation. Sequences of these endogenous RNA molecules are highly conserved, even among unrelated species, indicating their involvement in basic bio-logical processes, such as development, differentiation, proliferation or apoptosis. MiRNAs also participate on regulation of cancer stem cell functioning, immune system and malignant transformation. This review provides a comprehensive overview of miRNAs functions in esophageal cancer, their roles in key pathogenetic pathways and disease development, as well as their potential usage in clinical routine as bio-markers improving dia-gnosis, prognosis and prediction of therapeutic response. Through regulation of signaling pathways important in malignant transformation, miRNAs present also promising therapeutic targets.

Significance of aberrant DNA methylation for cancer diagnostics and therapy.

BACKGROUND: Epigenetics is a scientific field that covers changes in gene expression that are not caused by the alteration of the nucleotide sequence in the DNA strand. Together with sequential changes, epigenetic reprogramming is a recognized cancer hallmark driving carcinogenesis. The underlying mechanisms of epigenetically-driven gene expression changes are diverse. However, one of the most extensively studied mechanisms is a change in DNA methylation. Under physiological conditions, DNA methylation ensures tissue-specific gene silencing and helps to maintain genome stability. With malignant transformation, genomic DNA undergoes global hypomethylation as well as locus-specific hypermethylation in promoters of tumor suppressor genes. In the last few decades, specific aberrant DNA methylation changes have emerged as both cancer-associated biomarkers and therapeutic targets and prompted ongoing efforts to enhance both diagnostic and therapeutic means in oncology. PURPOSE: The main purpose of this review is to introduce both established and emerging DNA methylation-based biomarkers for cancer diagnostics with a focus on biomarkers that are either routinely used or have been developed as commercial tests with certification for their use within in vitro diagnostics. Furthermore, therapeutic options for targeting aberrant DNA methylation are described, including both approved compounds and newly developed agents undergoing clinical investigation.

[Epidemiological and clinico-pathological characteristics of patients with renal carcinoma: a single institution analysis of 544 cases]. / Epidemiologická a klinicko-patologická charakteristika pacientu s renálním karcinomem: analýza 544 prípadu z jednoho centra.

BACKGROUND: The incidence of renal cell carcinoma in the Czech Republic is one of the highest in the world. Curative treatment is still possible only surgically, while in the palliative treatment, partial success was reached using targeted therapies. While prognostic factors and models are commonly used in clinical practice, unfortunately, predictive biomarkers have not been found. The aim of our study was to verify the validity of selected prognostic factors on a consecutive patient cohort from the Czech population. PATIENTS AND METHODS: The patient cohort consisted of 544 patients with RCC diagnosed and/or treated at our institute from 2003 to 2010. Individual clinical and histological prognostic factors and Heng prognostic model were validated. RESULTS: Median time of follow-up for our cohort was 42 months (range 0.3-326 months), median age at diagnosis was 62 years, and almost 64% of patients were men. Distribution of clinical stages was as follows: 46.5% of I, II. 10.7%, III. 13.1%, IV. 20%. 26.4% of patients in stage I-III relapsed. We diagnosed mainly clear cell (84.6%) and papillary carcinoma (9.2%). Initially, 95.8% of patients underwent surgical treatment, systemic adjuvant and palliative treatment was applied in 3.7 and 37.7% of patients, respectively. Palliative targeted therapy was received by a total of 163 patients (30%). In first-line targeted therapy, the following median TTP was reached (in months): 10.8 for sunitinib, 6.3 for sorafenib and 5.2 months for immunotherapy. The most significant prognostic factors (p < 0.00001) were: stage of disease (HR = 9.61), size of the primary tumor (HR = 5.83), lymph nodes (HR = 8.26), presence of sarcomatoid tumor sections in the tumor (HR = 7.29), and tumor grade (HR = 4.0). Besides these, we also confirmed the prognostic importance of presence of eosinophilic granulations in the tumor (HR = 1.91, p = 0.02). When applying the Heng prognostic model, we achieved similar results for patients treated with targeted therapies. CONCLUSION: The obtained epidemiological and clinico-pathological data are consistent with previously published data. These prognostic factors can be used for a differentiated approach to patients with RCC, both for establishing follow-up plan for patients after surgery as well as indication for targeted therapies.

Biomarkers as prognostic and predictive factors in patients with hepatocellular carcinoma undergoing radiological oncological interventions.

BACKGROUND: Hepatocellular carcinoma is the most common malignant liver tumor in adults and thermal ablation and transarterial embolization are important methods of therapy. Thermal ablation can be used in early stages. Methods based on the transarterial approach, especially transarterial chemoembolization, play an important role in intermediate stage diseases. The success of procedures depends not only on the biological nature and the size of the tumor, on the technical design of the procedure and on the patient's response to treatment, but also on the molecular changes associated with these procedures. In addition to classic predictive and prognostic factors including age, patient comorbidities, Child-Pugh score, tumor characteristics, presence of large surrounding vessels, and portal vein thrombosis, molecular prognostic and predictive factors (serum biomarkers) are often mentioned in studies. Currently, only a-fetoprotein is routinely used as a prognostic biomarker; however, there are studies referring to new serum biomarkers that can potentially help to classical markers and imaging methods to determine the cancer prognosis and predict the success of therapy. These biomarkers most often include g-glutamyltranspeptidase, des- g-carboxyprothrombin, some types of microRNAs, inflammatory and hypoxic substances, whose serum levels are changed by the intervention therapies. Evaluation of these molecules could lead to the optimization of the medical intervention (choice of therapy method, timing of treatment) or change the management of patient follow-up after interventions. Although several biomarkers have shown promising results, most serum biomarkers still require validation in phase III studies. PURPOSE: The aim of this work is to present a comprehensive overview of classical and molecular biomarkers that could potentially help in the prognostic stratification of patients and better predict the success and effect of radiological intervention methods.

Molecular testing of endometrial carcinoma in real-world clinical practice.

BACKGROUND: Molecular classification has brought significant changes in the management of endometrial cancer (EC). In this article, we aim to analyze our first experience with an implementation of molecular testing into daily clinical practice. MATERIALS AND METHODS: In all newly diagnosed EC, the status of mismatch repair (MMR) and p53 proteins has been evaluated immunohistochemically as a part of the routine histopathological examination since May 2021. In tumors that do not meet clinical criteria for a low risk and those with MMR deficiency or p53 mutation, the molecular genetic testing of the POLE gene is performed as well. Recommendations for adjuvant treatment or follow-up are subsequently made based on the risk of recurrence. Genetic counselling is proposed to all patients with MMR-deficient tumors or family history of cancer. RESULTS: A total of 85 patients with newly diagnosed EC between May 2021 and May 2022 were enrolled in the analysis. The median age was 66 years. The results of molecular testing were as follows: 22 (26%) MMR-deficient, 8 (9%) p53-mutated and none POLE-ultramutated of those 40 tumors with performed POLE sequencing. A total of 46 (51%) patient had a low risk, 2 (2%) intermediate, 14 (16%) high-intermediate and 20 (24%) patients had a high risk of recurrence. Advanced or metastatic diseases were diagnosed in 6 (7%) patients. The median time between surgery and multidisciplinary tumor board decision was 21 days (8-36). A total of 76 (90%) patients underwent the whole treatment plan according to the recurrence risk. At the time of analysis, the results of genetic testing were available in 18 patients and revealed 4 (22%) carriers of a pathogenic variant in any of the genes associated with Lynch syndrome. CONCLUSION: Molecular testing combining immunohistochemical analyses of MMR and p53 proteins in all newly diagnosed EC patients with sequencing analysis of POLE in those with non-low-risk disease is feasible and does not prolong the time needed for treatment decision.

Expression levels of transcribed ultraconserved regions uc.73 and uc.388 are altered in colorectal cancer.

OBJECTIVES: The development of colorectal cancer (CRC) is characterized by multiple genetic alterations. Transcribed ultraconserved regions (T-UCRs) are a subset of 481 sequences longer than 200 bp, which are absolutely conserved between orthologous regions of human, rat and mouse genomes, and are actively transcribed. It has recently been proven in cancer systems that differentially expressed T-UCRs could alter the functional characteristics of malignant cells. Genome-wide profiling revealed that T-UCRs have distinct signatures in human leukemia and carcinoma. METHODS: In our study, we examined the expression levels of uc.43, uc.73, uc.134, uc.230, uc.339, uc.388 and uc.399 in 54 samples of primary colorectal carcinomas and 15 samples of non-tumoral adjacent tissues by real-time PCR. T-UCR expression levels were also correlated with commonly used clinicopathological features of CRC. RESULTS: Expression levels of uc.73 (p = 0.0139) and uc.388 (p = 0.0325) were significantly decreased in CRC tissue, and uc.73 indicated a positive correlation with overall survival (p = 0.0315). The lower expression of uc.388 was associated with the distal location of CRC (p = 0.0183), but no correlation of any evaluated T-UCR with clinical stage, grade and tumor diameter was observed. CONCLUSION: Our preliminary results suggest that uc.73 and uc.388 could be potential diagnostic and prognostic biomarkers in CRC patients.