Bioactivity of Recombinant Human SPARC Protein Against SKM-1 Cell

Secreted protein acidic and rich in cysteine (SPARC) has a complicated and pleiotropic biological role in cellular senescence during disease. However, the role of SPARC in secondary acute myeloid leukemia (sAML) is not yet fully understood. A high-efficiency HEK293F expression system was established to purify recombinant human SPARC (rh-SPARC), and Auto VP-capillary differential scanning calorimetry, CCK-8 kit, flow cytometry, and Western blot analyses were used to assess the characteristics and bioactivity of rh-SPARC. Isothermal titration calorimetry was performed to observe whether there was a direct interaction between rh-SPARC and cytarabine (Ara-C). The cell lines used in this study included SKM-1 and K562. The rh-SPARC protein suppressed the proliferation of SKM-1 cells in a concentration-dependent manner and suppressed the SKM-1 cell cycle in the G0/G1 phase, with a more significant observed when rh-SPARC and Ara-C were used in combination. In addition, the combination of rh-SPARC and Ara-C significantly reduced the relative levels of the pAkt protein in SKM-1 cells compared to rh-SPARC or Ara-C alone. The results indicated that rh-SPARC has a selective inhibition activity towards leukemia cells, as it could suppress the sAML cell line SKM-1 in the G0/G1 phase in a concentration-dependent manner. In addition, there a synergistic effect between rh-SPARC and Ara-C was observed, and rh-SPARC may enhance the sensitivity of SKM-1 cells to Ara-C by decreasing the phosphorylation of Akt.

CSTR: 32200.14.cjcb.2019.04.0010