Involvement of Small Non-Coding RNA and Cell Antigens in Pathogenesis of Extramedullary Multiple Myeloma.

Extramedullary multiple myeloma (EMD) is an aggressive disease; malignant plasma cells lose their dependence in the bone marrow microenvironment and migrate into tissues. EMD is a negative prognostic factor of survival. Using flow cytometry and next-generation sequencing, we aimed to identify antigens and microRNAs (miRNAs) involved in EMD pathogenesis. Flow cytometry analysis revealed significant differences in the level of clonal plasma cells between MM and EMD patients, while the expression of CD markers was comparable between these two groups. Further, miR-26a-5p and miR-30e-5p were found to be significantly down-regulated in EMD compared to MM. Based on the expression of miR-26a-5p, we were able to distinguish these two groups of patients with high sensitivity and specificity. In addition, the involvement of deregulated miRNAs in cell cycle regulation, ubiquitin-mediated proteolysis and signaling pathways associated with infections or neurological disorders was observed using GO and KEGG pathways enrichment analysis. Subsequently, a correlation between the expression of analyzed miRNAs and the levels of CD molecules was observed. Finally, clinicopathological characteristics as well as CD antigens associated with the prognosis of MM and EMD patients were identified. Altogether, we identified several molecules possibly involved in the transformation of MM into EMD.

Salivary microRNAs identified by small RNA sequencing as potential predictors of response to intensity-modulated radiotherapy in head and neck cancer patients.

PURPOSE: Progress in radiation therapy of head and neck squamous cell carcinomas (HNSCCs) is logically linked to the development of molecular predictors that would help to enhance individually tailored treatment. MicroRNA (miRNA) expression profiles in tumors have repeatedly been tested to optimize the molecular diagnostics of HNSCC. In addition to tumor tissues, miRNAs are stably present in body fluids, including saliva, and can thus be collected non-invasively. The aim of our current study was to evaluate whether salivary miRNAs have potential as response predictors in HNSCC patients treated with intensity modulated radiation therapy (IMRT). METHODS: In total 48 HNSCC patients treated by definitive IMRT were enrolled in our prospective study. To identify predictive salivary miRNAs, we used small RNA sequencing in 14 saliva samples of HNSCC patients and qRT-PCR validation of selected miRNA candidates in an independent set of 34 patients. RESULTS: We found that salivary miR-15a-5p and miR-15b-5p exhibited differential levels between patients with and without complete remission (p = 0.025 and p = 0.028, respectively). Subsequent Kaplan-Meier analysis confirmed that patients with higher levels of miR-15a-5p reached a significantly longer locoregional progression-free survival (LPFS) than those with low levels (p = 0.024). Finally, multivariate Cox regression analysis revealed that miR-15a-5p may serve as an independent predictive biomarker of LPFS in HNSCC patients treated with IMRT (HR 0.104; 95% CI 0.004-0.911; p = 0.04). CONCLUSIONS: We conclude that salivary miR-15a-5p may represent a potential biomarker for individualized treatment decision-making in HNSCC patients.

MicroRNA-15b-5p Predicts Locoregional Relapse in Head and Neck Carcinoma Patients Treated With Intensity-modulated Radiotherapy.

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.