Dynamic changes of different phenotypic and genetic circulating tumor cells as a biomarker for evaluating the...

Circulating tumor cells (CTCs) and relevant autophagy Beclin-1 genes expression are critical biomarkers for tumorigenesis and tumor progress. Here we investigated the relationship of dynamic changes of CTCs and Beclin-1 expression of CTCs with renal cell carcinoma (RCC) prognosis.

A total of 69 patients with RCC were enrolled and divided into two groups based on the postoperative status of distant metastasis, including metastasis-free group (n = 58) and metastatic group (n = 11). Demographic characteristics of each patient were recorded in detail. All 69 enrolled patients had received multiple CTC tests and peripheral blood samples were obtained at three different time points (1 day before operation, 6 months and 12 months after operation). Peripheral blood samples were drawn before each time point and CTCs were separated by using Can Patrol CTC enrichment technique. CTCs were divided into epithelial, mesenchymal and mixed phenotype based on different surface biomarkers. RNA in situ hybridization assay was used to detect the expression of Beclin1 gene.

The percentages of epithelial, mesenchymal and mixed CTCs were 11.64%, 28.04% and 60.32%, respectively. There were no significant differences of initial CTCs counts between metastasis-free group (8.43 ± 5.15) and metastatic group (7.71 ± 3.82) (P > 0.05). As for metastatic group, the number of mixed CTCs at 12 months postoperatively was significantly higher than that of mixed CTCs preoperatively and 6 months postoperatively (P < 0.05). In the metastatic group, the number of Beclin1 positive CTCs was significantly higher than that of Beclin1 negative CTCs preoperatively (P < 0.05), moreover, there were several significantly changes of Beclin1 positive CTCs with different types and at different time points.

The recurrence or metastasis of RCC was uncorrelated with initial CTCs counts, but probably related with the variation trend of CTCs, especially mesenchymal CTCs and Beclin1 positive CTCs.