Abstract:

Objective To study the differential expression of the lipid metabolism⁃related gene PRKAA2 in several common tumor cells and white blood cells（WBC），in order to provide a theoretical basis for the identifi⁃ cation of circulating tumor cells（CTCs）using PRKAA2. Methods RNA⁃sequencing data from The Human Protein Atlas（THPA）were used to infer the expression abundance of PRKAA2 in WBCs. The expression of PRKAA2 in multiple cancer cells and WBCs were evaluated with real ⁃time fluorescent quantitative polymerase chain reaction （qRT⁃PCR）. In situ padlock probe hybridization technology was used to visually detect the PRKAA2 expression of HepG2，U87，Hela，PC⁃3 and healthy individuals WBCs. We finally spiked tumor cells in WBCs to mimic the clinical samples to verify the accuracy of PRKAA2 used to identify tumor cells. Results Compared with WBC of healthy individuals，the expression of PRAKK2 in HepG2，U87，Hela，and PC⁃3 cells was significantly up⁃regulated， and the difference was statistically significant（all P < 0.05）. In situ padlock probe hybridization experiments showed a clear distinction of the molecular expression between HepG2，U87，Hela，PC⁃3 cells（all PRKAA2+）and WBC（PRKAA2⁃）. The PRKAA2 signal and CFSE fluorescence co⁃localized supporting the accuracy of PRKAA2 for the detection of tumor cells from Peripheral blood，which was confirmed using confocal microscopy. Conclusions The expression level of PRKAA2 in tumor cell lines HepG2，U87，Hela，PC⁃3 was significantly higher than that of WBC，and the difference in the fluorescence signal of PRKAA2 mRNA can be used to accurately identify tumor cells from a large number of WBCs.

Key words:

circulating tumor cells, lipid metabolism, biomarker, PRKAA2