BACKGROUND/AIM: Head and neck cancers are a heterogenous group of epithelial tumors represented mainly by squamous cell carcinomas (HNSCC), which are the sixth most common type of cancer worldwide. Surgery together with radiotherapy (RT) is among the basic treatment modalities for most HNSCC patients. Various biomarkers aiming to predict patients' response to RT are currently investigated. The reason behind this effort is, on one hand, to distinguish radioresistant patients that show weak benefit from RT and, on the other hand, reduce the ionizing radiation dose in less aggressive radiosensitive HNSCC with possibly less acute or late toxicity. MATERIALS AND METHODS: A total of 94 HNSCC patients treated by definitive intensity-modulated radiotherapy were included in our retrospective study. We used a global expression analysis of microRNAs (miRNAs) in 43 tumor samples and validated a series of selected miRNAs in an independent set of 51 tumors. RESULTS: We identified miR-15b-5p to be differentially expressed between patients with short and long time of locoregional control (LRC). Kaplan-Meier analysis confirmed that HNSCC patients with higher expression of miR-15b-5p reach a significantly longer locoregional relapse-free survival compared to patients expressing low levels. Finally, multivariable Cox regression analysis revealed that miR-15b-5p is an independent predictive biomarker of LRC in HNSCC patients (HR=0.25; 95% CI=0.05-0.78; p<0.016). CONCLUSION: miR-15b-5p represents a potentially helpful biomarker for individualized treatment decisions concerning the management of HNSCC patients.

• Klíčová slova
• Head and neck cancer, IMRT, locoregional control, miR-15b-5p, microRNA, radiotherapy,
• MeSH
• dlaždicobuněčné karcinomy hlavy a krku genetika   patologie   radioterapie   MeSH
• dospělí MeSH
• Kaplanův-Meierův odhad MeSH
• lidé středního věku MeSH
• lidé MeSH
• lokální recidiva nádoru genetika   patologie   radioterapie   MeSH
• mikro RNA genetika   MeSH
• nádorové biomarkery účinky záření   MeSH
• radioterapie s modulovanou intenzitou * MeSH
• regulace genové exprese u nádorů účinky záření   MeSH
• retrospektivní studie MeSH
• senioři MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• mikro RNA MeSH
• MIRN15 microRNA, human MeSH Prohlížeč
• nádorové biomarkery MeSH

BACKGROUND: Senescence is a fundamental biological process implicated in various pathologies, including cancer. Regarding carcinogenesis, senescence signifies, at least in its initial phases, an anti-tumor response that needs to be circumvented for cancer to progress. Micro-RNAs, a subclass of regulatory, non-coding RNAs, participate in senescence regulation. At the subcellular level micro-RNAs, similar to proteins, have been shown to traffic between organelles influencing cellular behavior. The differential function of micro-RNAs relative to their subcellular localization and their role in senescence biology raises concurrent in situ analysis of coding and non-coding gene products in senescent cells as a necessity. However, technical challenges have rendered in situ co-detection unfeasible until now. METHODS: In the present report we describe a methodology that bypasses these technical limitations achieving for the first time simultaneous detection of both a micro-RNA and a protein in the biological context of cellular senescence, utilizing the new commercially available SenTraGorTM compound. The method was applied in a prototypical human non-malignant epithelial model of oncogene-induced senescence that we generated for the purposes of the study. For the characterization of this novel system, we applied a wide range of cellular and molecular techniques, as well as high-throughput analysis of the transcriptome and micro-RNAs. RESULTS: This experimental setting has three advantages that are presented and discussed: i) it covers a "gap" in the molecular carcinogenesis field, as almost all corresponding in vitro models are fibroblast-based, even though the majority of neoplasms have epithelial origin, ii) it recapitulates the precancerous and cancerous phases of epithelial tumorigenesis within a short time frame under the light of natural selection and iii) it uses as an oncogenic signal, the replication licensing factor CDC6, implicated in both DNA replication and transcription when over-expressed, a characteristic that can be exploited to monitor RNA dynamics. CONCLUSIONS: Consequently, we demonstrate that our model is optimal for studying the molecular basis of epithelial carcinogenesis shedding light on the tumor-initiating events. The latter may reveal novel molecular targets with clinical benefit. Besides, since this method can be incorporated in a wide range of low, medium or high-throughput image-based approaches, we expect it to be broadly applicable.

• Klíčová slova
• CDC6, Cancer, DNA damage response, In situ hybridization, Micro-RNAs, Oncogene-induced senescence, R loops, Replication stress, SenTraGorTM, rDNA,
• MeSH
• epitelové buňky metabolismus   MeSH
• genom MeSH
• jaderné proteiny metabolismus   MeSH
• karcinogeneze MeSH
• kultivované buňky MeSH
• lidé MeSH
• mikro RNA metabolismus   MeSH
• nádory glandulární a epitelové genetika   patologie   ultrastruktura   MeSH
• onkogeny * MeSH
• proteiny buněčného cyklu metabolismus   MeSH
• proteiny metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• stárnutí buněk genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• CDC6 protein, human MeSH Prohlížeč
• jaderné proteiny MeSH
• mikro RNA MeSH
• proteiny buněčného cyklu MeSH
• proteiny MeSH

MicroRNAs are considered as promising prognostic and diagnostic biomarkers of human cancer since their profiles differ between tumor types. Most of the tumor profiling studies were performed on rarely available fresh frozen (FF) samples. Alternatively, archived formalin-fixed paraffin-embedded (FFPE) tissue samples are also well applicable to larger-scale retrospective miRNA profiling studies. The aim of this study was to perform systematic comparison of the miRNA expression profiles between FF and macrodissected FFPE tonsillar tumors using the TaqMan Low Density Array system, with the data processed by different software programs and two types of normalization methods. We observed a marked correlation between the miRNA expression profiles of paired FF and FFPE samples; however, only 27-38% of the differentially deregulated miRNAs overlapped between the two source systems. The comparison of the results with regard to the distinct modes of data normalization revealed an overlap in 58-67% of differentially expressed miRNAs, with no influence of the choice of software platform. Our study highlights the fact that for an accurate comparison of the miRNA expression profiles from published studies, it is important to use the same type of clinical material and to test and select the best-performing normalization method for data analysis.

• MeSH
• analýza hlavních komponent MeSH
• fixace tkání MeSH
• fixativa MeSH
• formaldehyd MeSH
• krční mandle metabolismus   MeSH
• kryoprezervace * MeSH
• lidé MeSH
• mikro RNA metabolismus   MeSH
• mikročipová analýza MeSH
• počítačové zpracování signálu MeSH
• software MeSH
• stanovení celkové genové exprese MeSH
• tonzilární nádory metabolismus   MeSH
• zalévání tkání do parafínu * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• fixativa MeSH
• formaldehyd MeSH
• mikro RNA MeSH