Retracted: Effects of RNA interference‐mediated silencing of toll‐like receptor 4 gene on proliferation and apoptosis of human breast cancer MCF‐7 and MDA‐MB‐231 cells: An in vitro study

Abstract

Breast cancer is known as the most prevalent cancer in women worldwide, and has an undeniable negative impact on public health, both physically, and mentally. This study aims to investigate the effects of toll-like receptor 4 (TLR4) gene silencing on proliferation and apoptosis of human breast cancer cells to explore for a new theoretical basis for its treatment. TLR4 small interference RNA (siRNA) fragment recombinant plasmids were constructed, including TLR4 siRNA-1, TLR4 siRNA-2, and TLR4 siRNA-3. Human breast cancer MCF-7 and MDA-MB-231 cells were assigned into blank, negative control (NC), TLR4 siRNA-1, TLR4 siRNA-2, and TLR4 siRNA-3 groups. MCF-7 and MDA-MB-231 cell growth was detected by MTT assay. Apoptosis and cell cycle were determined by flow cytometry. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were conducted to determine the expression of TLR4, CDK4, cyclin D1, Livin, Bcl-2, p53, c-FLIP, and caspase-3. In comparison with the NC and blank groups, the TLR4 siRNA-1, TLR4 siRNA-2, and TLR4 siRNA-3 groups showed decreased the expression of TLR4, inhibited proliferation of MCF-7 and MDA-MB-231 cells and promoted MCF-7 and MDA-MB-231 cell apoptosis, and the cells were blocked in G1 phase. In comparison with the NC and blank groups, in the TLR4 siRNA-1, TLR4 siRNA-2, and TLR4 siRNA-3 groups, siRNA-TLR4 significantly increased expression of p53 and caspase-3 in MCF-7 and MDA-MB-231 cells, while it decreased the expressions of CDK4, cyclinD1, Livin, Bal-2, and c-FLIP. The study demonstrates that TLR4 gene silencing inhibits proliferation and induces apoptosis of MCF-7 and MDA-MB-231 cells.

ERα36–GPER1 Collaboration Inhibits TLR4/NFκB-Induced Pro-Inflammatory Activity in Breast Cancer Cells

“…Several immune-related molecules have been found to be important for breast cancer progression-related mechanisms. Among them is the TLR4/myD88 pathway, which is expressed in tumor cells and has been linked to axillary lymph node metastasis and histological grade [ 8 ], while the inhibition of TLR4 expression impedes proliferation and promotes apoptosis of breast cancer cells [ 9 ]. Furthermore, activation of nuclear factor-kappaB (NFκB) is also common in breast cancer and has been associated with resistance to therapy and is present in more aggressive tumors.…”