Abstract:

Objective

To investigate the impact of high expression of twist gene on the stemness related characteristics of breast cancer SUM159 cells.

Methods

We established a twist-overexpression breast cancer SUM159 cell line as experimental group (SUM159/twist), and the cells with blank vector construction served as control group (SUM159/vector). The twist mRNA level were detected before and after twist gene transfection using RT-PCR. The proportion of cancer stem cells was investigated by flat clone formation,mammosphere assay and flow cytometry. The mRNA expressions of stemness-related genes SOX2, OCT4 and BMI1 were detected by RT-PCR. All data were expressed as ¯x±s and processed by t test.

Results

SUM159 cells with twist gene overexpression were successfully established. The relative expression of twist mRNA in SUM159/twist cells was 2.04±0.15, significantly higher than 0.49±0.45 in SUM159/vector cells(t=-16.33,P＜0.001).The colony number of clone formation was 92.75±4.85 in SUM159/twist cells, significantly higher than 44.50±5.19 in SUM159/vector cells(t=13.56, P＜0.001).The mammosphere number was 46.75±4.11 in SUM159/twist cells and 22.50±3.41 in SUM159/vector cells, and the difference was statistically significant(t=9.07, P＜0.001). Flow cytometry results showed that the proportion of ALDH1⁺ was (9.63±0.89)% in SUM159/twist cells and (2.31±0.21)% in SUM159/vector cells, indicating a significant difference(t =13.85, P＜0.001). The relative mRNA expressions of SOX2, OCT4 and BMI1 in SUM159/twist cells were 12.39±0.63,13.35±1.56 and 6.48±0.96, significantly higher than 1.61±0.33,2.67±0.28 and 2.70±0.35 in SUM159/vector cells respectively(t=-29.68,-11.61,6.43,all P＜0.001).

Conclusion

The twist gene promotes the stemness related capability of breast cancer SUM159 cells.

Key words: Breast neoplasms, Transcription factor, Neoplastic stem cells