Human Wharton's jelly mesenchymal stem cell secretome display antiproliferative effect on leukemia cell line and produce additive cytotoxic effect in combination with doxorubicin

• We isolated and cultured human Wharton's jelly mesenchymal stem cells and collected their secretome.
• We investigated effect of MSC secretome on K562 leukemia cell line.
• MSC secretome significantly reduce leukemia cell proliferation.
• MSC secretome display additive cytotoxic effect in combination with doxorubicin.

Mesenchymal stem cell (MSC) therapy moves toward clinic progressively. Recent evidences establish anticancer effect of mesenchymal stem cells. However multiple factors including type of cancer, MSC source, study design, and animal model play role in final outcome. Wharton's jelly – a newly approved source of MSCs – possesses superiorities to bone marrow as the conventional source; therefore investigation of its medical effects can produce beneficial results. In this survey we examined cytotoxic and proapoptotic effect of human Wharton's jelly MSC secretome on K562 human leukemia cells.MSCs were isolated from human Wharton's jelly of umbilical cord by explant culture method, then characterized according to ISCT criteria (morphology and plastic adherence, surface antigenicity and differentiation potential). MSC secretome was collected and its cytotoxic and proapoptotic effects on K562 cells in combination with doxorubicin were evaluated using BrdU cell proliferation assay and Annexin V–PI staining.Our results showed antiproliferative effect of mesenchymal stem cell secretome on K562 cancer cells, the effect was also added to cytotoxic effect of doxorubicin without induction of drug resistance. Human Wharton's jelly derived mesenchymal stem cells exerted cytotoxic effect on leukemia cells. Addition of that effect to anticancer effect of chemotherapeutic agents can leads to cytotoxic drug dose reduction and diminished side effects.