Abstract 653P
Background
This abstract presents the molecular profiling of prostate adenocarcinoma after surgical or combination treatment.
Methods
The study included 66 formalin-fixed paraffin-embedded (FFPE) tissue specimens of prostate cancer (PCa) (tumor volume at least 75% of the total material volume, without areas of necrosis and hemorrhages): 31 samples were taken after 6 cycles of neoadjuvant therapy with docetaxel and degarelix followed by radical prostatectomy (NCHT/RPE group) and the control group (RPE) included 35 samples after only surgery. The microdissection size was from 3 to 20 μm. It was performed by a local pathologist. RNA supernatant was isolated from paraffin sections by dewaxing with mineral oil. RNA supernatant concentration was assessed on a Qubit 2.0 fluorimeter (Invitrogen), protocol #0001987. Profiling of all samples were performed on the miRCURY LNA™ Universal RT(Exiqon) test system with real-time polymerase chain reaction (PCR) with SYBR® green on CFX96 Real Time System (“Bio-Rad”) thermocycler, protocol #6.2. In the calculations, a semi-quantitative assessment of the level of miRNA expression was used relative to the average expression level of all samples (ΔΔCt).
Results
The average concentration of RNA supernatant in the NCHT/RPE group was lower than the control group (P=0.002): ΔС=3.77±4.51ng/ml (0.05-1.1) against ΔС (RPE group) = 19.66±15.69 ng/ml (2.88-66.0). Profiling showed differences in PCR cycles (ΔCt>1.5) for miRNA primers: hsa-mir-181a-5p, hsa-mir-126-3p, hsa-mir-200c-3p, hsa-mir-106b-5p, hsa-mir221-3p, hsa-mir34. The ΔΔCt of these miRNAs were different (P>0.05) into groups except miRNA-200c: ΔΔCt=4.75±4.00ed. against 3.34 ± 3.83ed. (P=0.14). The correlation analysis revealed association with ΔΔCt-miRNA126 and the frequency of the positive surgical margin (F= 10.34, P = 0.015). Decreasing ΔΔCt-miRNA126 from 10.82±6.0ed. to 7.37±5.46ed. was noted after neoadjuvant treatment (U-test P=0.012). The equation of the dependence of overall survival (OS) was formulated during regression analysis on the ΔΔCt-miRNA-106b indices: OS=24+ 2.2*MIR106B, which was able to predict OS in 19.2% of patients.
Conclusions
The analysis revealed that overexpression of some miRNAs is blocked in prostate cancer patients receiving combined treatment.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.