KIF4A on TGF-Β1/Smad3 Pathway: A Preliminary Investigation on the Proliferation and Immune Response in In-Vitro Cultured Breast Cancer Cells

Aim: This study aims to explore the relevant biomarkers in breast cancer (BC).

Background: Kinesin family member 4A (KIF4A) is a member of the Kinesin 4 subfamily of kinesin-related proteins, which has already been investigated in diverse types of tumors.

Objective: Our current study aims to investigate the involvement of KIF4A in BC.

Methods: KIF4A expression level was firstly predicted based on the data from the Cancer Genome Atlas (TCGA) and then assessed in BC cells. Subsequently, after silencing KIF4A, its effects on BC cell proliferation and metastasis, as well as on immune-related cytokines, were assessed by cell counting kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU) staining and quantitative Polymerase Chain Reaction (qPCR). Next, western blotting assays were used to detect the expression and phosphorylation levels of transforming growth factor-beta 1 (TGF-β1) and small mothers against decapentaplegic 3 (Smad3) in BC cells after KIF4A silencing and the role of the pathway was verified by Smad3 inhibitor (SIS3).

Results: KLF4A was highly expressed in BC, and silencing of KIF4A repressed the proliferation and metastasis potential of in-vitro cultured BC cells, concurrent with the reduction of CDH2, VIM, and SNAIL levels, yet the increase in the expression of CDH1. In the meantime, KIF4A knockdown diminished the levels of IL4, IL10, and TGFB while promoting those of IL1B and IL6 in BC cells. Further, enhanced phosphorylation of Smad3 was observed in BC cells, and the intervention of SIS3 restrained the proliferation and metastasis potential of BC cells and reduced the expression levels of CDH2, VIM, and Snail whilst promoting that of CDH1. Additionally, SIS3 intervention increased IL1B and IL6 levels and decreased IL4, IL10 and TGFB levels in BC cells.

Conclusion: This study preliminarily explored the involvement of KIF4A and TGF-β1/Smad3 together in BC, which may provide another insight into the management of BC in clinical practice.