EXPRESSION PROFILE OF miR-145, -182, -21, -27a, -29b, and -34a IN BREAST CANCER PATIENTS OF YOUNG AGE.

BACKGROUND: Breast cancer (BC) in young women remains a significant public health concern. While progress has been made in understanding the etiology, diagnosis, and treatment of BC in this population, challenges persist. The identification and utilization of prognostic biomarkers offer valuable tools for tailoring treatment strategies and improving outcomes for BC patients. AIM: To evaluate the relationship between the expression of tumor-associated microRNAs and the clinical and pathological features of BC in young patients. MATERIALS AND METHODS: The work is based on the results of the examination and treatment of 50 women younger than 45 years with stage I-II BC. miR-145, -182, -21, -27a, -29b, and -34a expression in tumor samples was analyzed by the real-time reverse transcription polymerase chain reaction. RESULTS: Higher expression of miR-182, -21, and -29b and lower levels of miR-27a were associated with tumor stage in young BC patients. Patients without lymph node metastases (N0) had significantly higher levels of miR-182, -27a, and -34a and lower levels of miR-29b compared to N1 cases (p < 0.05). Expression of miR-145, -182, -21, -27a, and -29b was associated with molecular BC subtypes. CONCLUSION: Obtained results show that a high malignancy degree of BC in young women is associated with an increase in the miR-182, -21, -29b, and -34a expressions and a decrease in the miR-27a level in the tumor tissue, which indicates the prospects of the use of them for predicting the aggressiveness of the disease.

FEATURES OF COL1A1 EXPRESSION IN BREAST CANCER TISSUE OF YOUNG PATIENTS.

BACKGROUND: In the last decades, the incidence of breast cancer (BCa) in young women has been increasing steadily. The quantitative indicators of expression of collagen, which play important role in stromal microenvironment, and their association with the age and survival rates of BCa patients have not been yet definitively clarified. AIM: To investigate the relationship between the COL1A1 gene expression at the mRNA and protein levels in BCa tissue and the clinicopatological features and survival rates of BCa patients of different age groups. MATERIALS AND METHODS: The study was conducted on the clinical material of 50 patients with stage I-III BCa. COL1A1 gene expression at the mRNA and protein levels in BCa tissue were studied using the real-time PCR and immunohistochemical methods, as well as the bioinformatic analysis (UALCAN and Kaplan - Meier Plotter databases). RESULTS: The bioinformatic analysis showed that BCa tissue is characterized by 6.0 times (p < 0.05) higher level of COL1A1 mRNA compared to normal breast tissue. The correlation of COL1A1 expression at the mRNA and protein levels with the molecular subtype of neoplasms was demonstrated. According to Kaplan - Meier Plotter database, a low level of expression of COL1A1 protein level in BCa tissue is associated with lower rates of relapse-free survival of patients. The ex vivo study of the clinical material revealed a decrease in COL1A1 protein expression in tumor tissue of young patients with BCa of T3 category (p < 0.0374), low differentiation grade (p < 0.0163) and basal molecular subtype (p < 0.0001). A correlation between the expression of COL1A1 at the mRNA and protein levels and the expression status of estrogen receptors (p < 0.0001) and progesterone receptors (p < 0.0040) was established. The relapse-free 3-year survival rate of young BCa patients is significantly lower in the presence of a low COL1A1 optical density index in the tumor tissue. CONCLUSIONS: The identified relationship between COL1A1 expression and such indicators of BCa malignancy as tumor size, differentiation grade, molecular subtype, receptor status, and the recurrencefree survival of patients indicates the prospects of its use to predict the aggressiveness of the BCa course in young patients.