The Effects of Mesenchymal Stem Cells on Antimelanoma Immunity Depend on the Timing of Their Administration

Figure 1

MSC-based modulation of melanoma growth depends on the time of MSC administration. Delayed tumor growth, observed in B16F10+MSC^1d-treated mice, and rapid melanoma growth, noticed in B16F10+MSC^14d-treated animals from day 18, were evidenced by the measurement of tumor volumes at different days after tumor induction (a). Significantly lower average tumor volume (b) and tumor weight (c) were observed in B16F10+MSC^1d-treated mice than in B16F10+PBS^1d-treated animals at day 28. Oppositely, average tumor volume (b) and tumor weight (c) were significantly greater in B16F10+MSC^14d-treated mice than in B16F10+PBS^14d-treated animals at day 28. The lowest survival rate was noticed in B16F10+MSC^14d-treated animals, while all of B16F10+MSC^1d-treated mice survived to the last, 28^th day of experiment (d). The difference in the survival between experimental groups was statistically nonsignificant (“ns”). Average animal weight at different days after tumor induction demonstrates reduced weight loss in MSC-treated, melanoma-bearing mice (e). The ratios of proinflammatory to anti-inflammatory cytokines (TNF-α : IL-10, TNF-α : TGF-β, IFN-γ : IL-10, IFN-γ : TGF-β, IL-12 : IL-10, and IL-12 : TGF-β) were significantly lower in plasma samples of B16F10+PBS^1d-treated mice than in plasma samples of B16F10+PBS^14d-treated animals (f). Plasma samples were collected 24 h and 14 days after tumor induction. Values are presented as the ; mice/group. , .

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