Fig. 3: In vitro growth of MM cells is suppressed by MSCs, but suppression inversely correlates with the level of MSC senescence.

A Luciferase-expressing MM cell lines were cultured alone (monoculture) or in coculture with MSCs from young non-cancer controls (KMM1, RPMI-8226) or eight-week-old mice (5TGM1). After 3 days, the relative number of MM cells was quantified by bioluminescence imaging (BLI). Graphs depict mean ± SEM of three (KMM1, RPMI-8226) or four independent experiments (5TGM1). B Luciferase-expressing MM cell lines were cultured in conditioned media (CM) from MSCs from young non-cancer controls (KMM1, RPMI-8226) or eight-week-old mice (5TGM1) or non-conditioned medium (αMEM media). After 3 days, the relative number of MM cells was quantified by BLI. Graphs depict mean ± SEM of three independent experiments (KMM1, RPMI-8226) or mean ± range of two independent experiments (5TGM1). C MSCs from young (n = 8) or aged (n = 8) non-cancer controls or MGUS (n = 8) or MM (n = 8) patients were seeded 24 hours prior to adding luciferase-expressing KMM1 cells. After 3 days, relative KMM1 cell numbers per well were quantitated using BLI and normalised to KMM1 cell numbers in monoculture. Box and whisker plots depict median and interquartile ranges. Scatter dot plots showing correlation of MSC % β-gal positivity (D) and CDKN2A expression (E) with relative KMM1 cell number in coculture with MSCs from young and aged non-cancer controls and MGUS and MM patients, normalised to cell numbers in monoculture. p values are shown for pairedt tests (A, B), Kruskal-Wallis test with Dunn’s post-test (C) or Pearson’s correlation (D, E).