Differential properties of human stromal cells from bone marrow, adipose, liver and cardiac tissues

Mesenchymal stromal cells (MSCs), derived from several tissues including bone marrow and adipose tissue, are being evaluated in clinical trials for a range of diseases. Virtually all tissues of the body contain stromal cells, yet it is unknown whether these sources are similar in phenotype and function.

We have isolated stromal cells from several human tissues including bone marrow (BM-MSCs), heart (heart stroma, HS), adipose (adipose stroma, AS) and liver (liver stroma, LS) and compared the morphology, phenotype and functional properties of these stromal cell populations.

The cellular phenotype of each population was identical, namely, CD105+, CD73+, CD90+, CD34- and CD45-. In addition, morphology and differentiation potential were comparable. Co-culture studies revealed similar supportive potential of BM-MSCs, AS and LS with hematopoietic cells or tumor cells. In contrast, significant inhibition of proliferation of both cells types was obtained with HS, with significant loss of viability with tumor cells, demonstrating a unique functional property of HS with regard to tumor cell proliferation.

Although stromal cells from different tissues have similar morphology and phenotype, their functional properties vary, requiring critical evaluation of stromal cells before use in non-homologous settings. HS may play a key role in inhibiting proliferation of tumor cells in the heart, providing the reason for the low occurrence of tumor development. Given the tumor-supportive property of BM-MSCs and AS, the use of these cells in cardiac tissue may result in replacement of a tumor-inhibitory stroma with a tumor-supportive microenvironment.