Combinatorial Control of Transgene Expression by Hypoxia-Responsive Promoter and MicroRNA Regulation for Neural Stem Cell-Based Cancer Therapy

Figure 2

NSCs response to tumor hypoxia. (a) mRNA expression level of hypoxia-related signal receptors, c-Met, CXCR4, c-Kit, and VEGFR2, in NSCs cultured 24 h under normoxic and hypoxic conditions is quantified by qPCR. (b) Migration rates of NSCs towards MCF-7 breast cancer cells under normoxic and hypoxic conditions are quantified by Boyden chamber cell migration assays. MCF-7 cells were seeded in the lower chamber, and blank medium in the lower chamber was used for the negative control group. NSCs were stained with calcein-AM and seeded in the upper chamber. After 24 h, the labelled NSCs which migrated toward the lower chamber were evaluated (𝑛=5). Top: percentage of migrated NSCs. Bottom: fluorescence images showing the migration of NSCs toward the lower chambers. Error bars: s.d. ^∗𝑃<0.05, ^∗∗𝑃<0.01.

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