The presence of LC3B puncta and HMGB1 expression in malignant cells correlate with the immune infiltrate in breast cancer.

Fiche publication

Date publication

mai 2016

Journal

Autophagy

Auteurs

Membres identifiés du Cancéropôle Est :
Dr ARNOULD Laurent , Pr GHIRINGHELLI François , Dr LADOIRE Sylvain

Tous les auteurs :
Ladoire S, Enot D, Senovilla L, Ghiringhelli F, Poirier-Colame V, Chaba K, Semeraro M, Chaix M, Penault-Llorca F, Arnould L, Poillot ML, Arveux P, Delaloge S, Andre F, Zitvogel L, Kroemer G

Lien Pubmed

https://www.ncbi.nlm.nih.gov/pubmed/26979828

Résumé

Several cell-intrinsic alterations have poor prognostic features in human breast cancer, as exemplified by the absence of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β)-positive puncta in the cytoplasm (which indicates reduced autophagic flux) or the loss of nuclear HMGB1 expression by malignant cells. It is well established that breast cancer is under strong immunosurveillance, as reflected by the fact that scarce infiltration of the malignant lesion by CD8(+) cytotoxic T lymphocytes or comparatively dense infiltration by immunosuppressive cell types (such as FOXP3(+) regulatory T cells or CD68(+) tumor-associated macrophages), resulting in low CD8(+):FOXP3(+) or CD8(+):CD68(+) ratios, has a negative prognostic impact. Here, we reveal the surprising finding that cell-intrinsic features may influence the composition of the immune infiltrate in human breast cancer. Thus, the absence of LC3B puncta is correlated with intratumoral (but not peritumoral) infiltration by fewer CD8(+) cells and more FOXP3(+) or CD68(+) cells, resulting in a major drop in the CD8(+):FOXP3(+) or CD8(+):CD68(+) ratios. Moreover, absence of HMGB1 expression in nuclei correlated with a general drop in all immune effectors, in particular FOXP3(+) and CD68(+) cells, both within the tumor and close to it. Combined analysis of LC3B puncta and HMGB1 expression allowed for improved stratification of patients with respect to the characteristics of their immune infiltrate as well as overall and metastasis-free survival. It can be speculated that blocked autophagy in, or HMGB1 loss from, cancer cells may favor tumor progression due to their negative impact on anticancer immunosurveillance.