Bacterial extracellular vesicles affect endocrine therapy in MCF7 cells

Area of Science:

• Microbiology
• Oncology
• Cell Biology

Background:

• The gut microbiome plays a crucial role in breast cancer development and progression.
• Investigating the influence of specific bacteria, like Klebsiella, on breast cancer treatment is essential.

Purpose of the Study:

• To examine the impact of Klebsiella-derived bacterial extracellular vesicles (EVs) on endocrine therapy efficacy in breast cancer.
• To determine the effect of Klebsiella EVs on tamoxifen treatment in MCF7 cells.

Main Methods:

• Next-generation sequencing was used to analyze microbiomes in breast cancer patients and healthy controls.
• MCF7 cells were treated with tamoxifen, with and without Klebsiella pneumoniae-derived EVs, followed by quantitative real-time PCR and Western blot analysis.

Main Results:

• Klebsiella was found to be more abundant in breast cancer patients, particularly in the luminal A subtype.
• The addition of K. pneumoniae EVs significantly enhanced the anti-hormonal effects of tamoxifen in MCF7 cells.
• This enhanced efficacy was linked to increased expression of Cyclin E2 and phosphorylated ERK (p-ERK).

Conclusions:

• Extracellular vesicles derived from K. pneumoniae play a significant role in hormone therapy response in breast cancer cells.
• These findings offer novel insights into breast cancer pathogenesis and the potential of targeting the microbiome for improved hormone therapy.