Absence of Lipopolysccharide (LPS) expression in Breast Cancer Cells

Abstract The association between bacterial activity and tumorigenesis has gained attention in recent years, alongside the well-established link between viruses and cancer. A recent study proposed the presence of intracellular bacteria in cancer cells, particularly in melanomas and breast cancers, with detectable bacterial DNA. The authors suggested that these bacteria contribute to the tumors’ development. We sought to replicate these findings using the same experimental methods on different tissue microarrays. Our investigation included 129 breast cancer samples, but we found no evidence of LPS expression within cancer cells. Instead, LPS immunoreactivity was observed in ducts or immune cells, specifically macrophages. The discrepancies in LPS staining warrant caution in interpreting the reported observations, and further research is needed to elucidate the potential role of intracellular bacteria in cancer development.