Anti-IL-8 monoclonal antibodies inhibits the autophagic activity and cancer stem cells maintenance within breast cancer tumor microenvironment.

Background: Breast cancer tumor microenvironment (TME) is a promising target for immunotherapy. Autophagy, and cancer stem cells (CSCs) maintenance are essential processes involved in tumorigenesis, tumor survival, invasion, and treatment resistance. Overexpression of angiogenic chemokine interleukin-8 (IL-8) in breast cancer TME is associated with oncogenic signaling pathways, increased tumor growth, metastasis, and poor prognosis.

Objective: Thus, we aimed to investigate the possible anti-tumor effect of neutralizing antibodies against IL-8 by evaluating its efficacy on autophagic activity and breast CSC maintenance.

Methods: IL-8 monoclonal antibody supplemented tumor tissue culture systems from 15 females undergoing mastectomy were used to evaluate the expression of LC3B as a specific biomarker of autophagy and CD44, CD24 as cell surface markers of breast CSCs using immunofluorescence technique.

Results: Our results revealed that anti-IL-8 mAb significantly decreased the level of LC3B in the cultured tumor tissues compared to its non-significant decrease in the normal breast tissues.Anti-IL-8 mAb also significantly decreased the CD44 expression in either breast tumors or normal cultured tissues. While it caused a non-significant decrease in CD24 expression in cultured breast tumor tissue and a significant decrease in its expression in the corresponding normal ones.

Conclusions: Anti-IL-8 monoclonal antibody exhibits promising immunotherapeutic properties through targeting both autophagy and CSCs maintenance within breast cancer TME.