To the editor,


We read with great interest the paper by Pan et al. “LLY17, a novel small molecule STAT3 inhibitor induces apoptosis and suppresses cell migration and tumor growth in triple-negative breast cancer” [1] published in the latest issue of Breast Cancer Research and Treatment. We would like to congratulate Pan et al. for designing a novel small molecule STAT3 inhibitor (LLY17) that can inhibit growth of triple-negative breast cancer. LLY17 may provide a new candidate for triple-negative breast cancer treatment. There are, however, issues raised in this paper that are worthy of comment and attention.

In Fig. 3b, SUM159 cells were transfected with Control siRNA or STAT3 siRNA. The authors found that cell viability of Control siRNA decreased to nearly 50% after treatment with LLY17 (0.25 or 1 μM) for 48 h. However, the authors claimed that LLY17-treated cells showed significant inhibition of cell migration in SUM159 cells without obvious changes of cell viability, which was almost up to 100% after treatment with higher concentrations (2.5 or 5 μM) of LLY17 for 42 h (Fig. 5c). Although Control siRNA SUM159 cells and SUM159 cells, 42 h and 48 h were not exactly the same, the cell viability in high concentration group should not be higher than that in low concentration group. The similar phenomenon also occurred in MDA-MB-231 cells. These results confused us.


Yours sincerely,


Renba Liang Ph.D.


Guangxi Medical University Cancer Hospital