Figure 3. GD2⁺ and CD44^hiCD24^lo cells have a similar gene signature.

(A) Heat maps derived from microarray analysis of CD44^hi/loCD24^lo/hi and GD2^+/– populations of HMLER cells. (B) Two hundred thirty-one genes of the top 600 differentially expressed genes were identical in GD2⁺ versus GD^– and CD44^hiCD24^lo versus CD44^loCD24^hi groups. These genes were cross-classified in a 2-by-2 table by GD2⁺ up-/downregulation and CD44^hiCD24^lo up-/downregulation. Pearson’s χ² test with a Yates continuity correction was applied to assess the association. Statistical significance was assessed at the 0.05 level. (C) Biosynthesis reaction of GD2. (D and E) To measure the expression of GD2S/GD3S mRNA, CD44^hiCD24^lo or CD44^loCD24^hi and GD2^+/– cells from HMLER (D) or MDA-MB-231 cells (E) were FACS sorted, and mRNA was analyzed using qRT-PCR. *P < 0.001.