Significance of expression of tumor-associated microRNA-21 and -375 for predicting the course of cancer of oral cavity.

AIM: To investigate the features of expression of miRNA-21 and miRNA-375 in tumor cells of patients with cancer of oral cavity (COC) and to determine the possibility of their use to predict the aggressiveness of COC course. MATERIALS AND METHODS: The work is based on the results of examination and treatment of 50 patients with stage II-IV COC. miRNA expression in tumor cells was analyzed by real time reverse transcription polymerase chain reaction. RESULTS: High levels of miRNA-21 expression (> 0.26 a.u.) and miRNA-375 (> 0.36 a.u.) were determined in 72.0% and 63.0% of cases. We revealed a tendency to decreased miRNA-21 expression and increased miRNA-375 expression in tumors of patients with recurrence-free survival less than 12 months and the presence of metastatic lesions in regional lymph nodes. In patients with COC of low differentiation grade, the level of miRNA-21 was 2.0 times lower compared with tumors of moderate differentiation grade (p < 0.05), while the expression of miRNA-375, on the contrary, was higher in tumors of low differentiation grade. A decreased expression of miRNA-21 (< 0.26 a.u.) against the background of decreased levels of miRNA-375 (< 0.36 a.u.) in tumor cells was associated with worse recurrence-free survival. CONCLUSIONS: The obtained results indicate the relation between the main clinical and pathological characteristics of patients with COC and the levels of miRNA-21 and -375 expression in tumor tissue, which indicates the involvement of these miRNAs in the formation of COC malignancy evidencing on their potential usefulness as additional prognostic markers.

Association of circulating miR-21, -205, and -182 with response of luminal breast cancers to neoadjuvant FAC and AC treatment.

AIM: To identify the association of serum miRNAs with neoadjuvant polychemotherapy response in patients with breast cancer of luminal A and B subtypes. MATERIALS AND METHODS: We analyzed the expression levels of circulating miR-21, -155, -182, -373, -199a, -205, -375 in serum of 182 breast cancer patients using real-time polymerase chain reaction. Each case was characterized by TMN criteria using morphological and immunohistochemical analyses. RESULTS: Serum levels of miR-205 and -375 are associated with the response of luminal A tumors and miR-205 and -21 with the response of luminal B tumors to neoadjuvant polychemotherapy in fluorouracil + doxorubicin + cyclophosphamide and doxorubicin + cyclophosphamide regimens. In addition, we found correlation of miR-155, -182, -199a, -375 with 3-year relapse-free survival of patients. Based on the obtained data, we developed innovative prognostic and predictive panels to assess the drug sensitivity of tumors and lower the risk of breast cancer recurrence, which would significantly improve the treatment outcomes and the quality of life of patients. CONCLUSIONS: Serum levels of miR-155, -182, -199a, -205, -375 can be used as predictive and prognostic panel for monitoring BC course in Ukrainian population.