Summary. Background: Classification of breast cancer (BC) in the molecular subtypes had the enormous impact on the development of the individualized therapy. Nevertheless, there is a need for additional biomarkers that would help to refine molecular subtypes of BC and propose the therapeutic approach for each patient. Aim: To study differential expression patterns of AIP, UCKL1, and PKN1 genes in blood sera and tumor tissue of patients with BC of different molecular subtypes. Materials and Methods: The total extracellular RNA was isolated from serum of 26 BC patients. cDNAs was synthesized and quantitative polymerase chain reaction was performed. Also, immunohistochemical studies of UCKL, AIP and PKN1 were performed on deparaffined tissue sections. The study was supplemented by a bioinformatic analysis of the publicly available databases. Results: AIP and UCKL-1 extracellular mRNA levels were 100–1000-fold increased in blood sera of all BC patients, compared to the healthy donors. The highest levels were detected in the luminal A and HER2 (ERRB2) BC subtypes. The highest levels of PKN1 were detected blood sera of the patients with luminal B and basal subtypes; its expression levels were just 10–100-fold higher in BC samples compared to healthy donors. Conclusions: The UCKL1, AIP, PKN1 genes are overexpressed at the mRNA level in blood sera of BC patients compared to the sera of healthy individuals. Among three genes under study, only for the AIP gene, the pattern of extracellular mRNA expression in sera paralleled to protein expression in BC tissues of each specified molecular subtype.

Background: The evolution of research on the therapy of prostate cancer (PC) depends on a study of molecules that are involved in the progression of this disease. Nevertheless, there is a need for additional biomarkers that would help to refine the molecular profile of PC and propose the personalized therapeutic approach. Aim: To study differential expression patterns of the AIP, UCKL1, and PKN1 genes in blood sera and tumor tissue of patients with PC with different Gleason scores. Materials and Methods: The total extracellular RNA was isolated from blood sera of 44 PC patients and 4 healthy donors. cDNAs were synthesized and quantitative polymerase chain reaction (qPCR) was performed. Immunohistochemical study of the UCKL, AIP and PKN1 proteins was performed on deparaffinized sections of tumors. The study was supplemented by a bioinformatic analysis of the publicly available databases. Results: The UCKL1, AIP, PKN1 genes were overexpressed at the mRNA level in blood sera of PC patients, compared to healthy donors. Extracellular mRNA levels of AIP and UCKL-1 were 100-1000-fold increased in all PC samples compared to the healthy donors but without significant inequality between the groups of PC cases differing by the Gleason score. The highest levels were detected in the samples from PC patients with the Gleason score > 9. The PKN1 expression was higher in PC patients compared with healthy donors but without significant difference between the groups. Conclusions: From the three chosen genes, AIP and UCKL1 showed similar pattern of expression assessed either by extracellular mRNA levels in patient sera or the protein in PC tissues. AIP was up to 1000-fold increased in all PC samples, compared to the healthy donors, with the highest levels in PC cases with Gleason score > 9. Expression levels of the AIP and UCKL1 genes in the PC patient sera may be used as an additional criterion for prognosis of tumor progression.