Umbilical cord fibroblasts: Could they be considered as mesenchymal stem cells?

Table 1 Immunophenotype and differentiation potential comparison between umbilical cord matrix derived fibroblasts and bone-marrow-mesenchymal stem cells

		Immunophenotype	Gene expression	Differentiation potential
BM-MSC	Positive for:	CD90, CD73, CD105, CD13, CD44[1]	CTSB, CTSD, PHB[10], BSP[7], Leptin[12]	No report for osteo-, adipo or chondrogenic differentiation failure
		SSEA-4, LNGFR[6], CD146+++[7]	HOX-gene[7], DLK-1[16], pSmad2 (low and modulated)[12]
	Negative for:	CD14, CD34[1], CD56[7]
UC-MSC	Positive for:	CD90, CD73, CD105, CD13, CD44[1]	PAI-1, MnSOD[10], HOX-gene (different expression pattern)[7]	Reports for adipo-[13,15] and osteogenic[7,12] differentiation failure
		CD56, CD146++[7]	pSmad2 (high and constitutive)[12]
	Negative for:	CD14, CD34[1], SSEA-4, LNGFR[6]	CTSB, CTSD, PHB[10], BSP[7], Leptin[12], DLK-1 (or weakly)[16]

UC-MSC: Umbilical cord-mesenchymal stem cells; BM-MSC: Bone marrow-mesenchymal stem cell.