Fig. 4: Pharmacological and genetic activation of autophagy enhances the cytolytic activity of NK cells in vivo.

A Tumor model and treatment scheme of tumor-bearing mice with NK cells, treated or not with Metformin. B, C Tumor growth curves (B) and tumor volume at the end of the experiment (C) referred to mice treated as described in A (n = 5 control, n = 10 untreated NK cells, n = 12 Metformin-treated NK cells). D–F Graphs showing NK cell maturation status (D), frequency of LC3B⁺ cells (E), and effector molecule expression in tumor-infiltrating NK cells. n = 9 mice NK cells, n = 11 mice Metformin-treated NK cells. G Tumor model and treatment scheme of tumor-bearing mice with NK-92 cells, treated or not with Metformin. H, I Tumor growth curves (H) and tumor volume at the end of the experiment (I) referred to mice treated as described in G (n = 11 control, n = 11 NK-92 cells, n = 12 Metformin-treated NK-92 cells, data pooled from two independent experiments). J, K Graph showing the absolute number (J) and effector function expression (K) of tumor-infiltrating NK-92 cells. n = 11 control, n = 11 NK-92 cells, n = 12 Metformin-treated NK-92 cells. L, M Tumor growth curves (L) and tumor volume at the end of the experiment (M) referred to mice treated as described in G (n = 9 scramble NK-92 cells, n = 9 BECN1 overexpressing NK-92 cells). N Graph showing the absolute number of tumor-infiltrating NK-92 cells. n = 9 scramble NK-92 cells, n = 9 BECN1 overexpressing NK-92 cells. O, P Graphs showing the frequency of LC3B⁺ cells (O) and effector function expression (P) in tumor-infiltrating NK-92 cells. n = 9 scramble NK-92 cells, n = 9 BECN1 overexpressing NK-92 cells. Q Graph showing the frequency, referred to live cell gate, of circulating NK-92 cells in mice injected with control or BECN1 overexpressing NK-92 cells (n = 12 mice/group). R, S Graph showing the frequency of LC3B⁺ cells (R) and effector function expression (S) in peripheral blood circulating NK-92 cells. n = 12 sample/group. Symbols in (B), (H), and (L) represent mean and error bars indicate SEM; one-way ANOVA test with Holm-Šídák’s multiple-comparisons test (B, H) or two-tailed unpaired t test (L), comparing area under the curve (AUC). Data in (C) and (I) are presented as Min to Max box-and-whisker plot, the box extends from the 25th to 75th percentiles, and the whiskers reach the sample maximum and minimum values, the median indicated is at center line and the mean value is indicated as “+”; one-way ANOVA test with Holm-Šídák’s multiple-comparisons test. Data in (D–F), (J), (K), and (M–S) are presented as Min to Max box-and-whisker plot, the box extends from the 25th to 75th percentiles and the whiskers reach the sample maximum and minimum values, the median is indicated at center line and the mean value is indicated as “+”; two-tailed unpaired t test.