Role of asparagine synthetase in doxorubicin-induced resistance

Research has shown drug resistance as the major cause of failure of cancer chemotherapy. In this study, doxorubicin-sensitive human uterine cancer cell (hUCC) MES/SA, as well as doxorubicin-resistant hUCC MES/SA-DxR 2μM and MES/SA-DxR 8μM were used. Subsequently, asparagine synthetase (ASNS), a protein that had previously been proposed to be a putative cancer drug target in our laboratory, was silenced by siRNA knockdown to study the mechanism of doxorubicin-induced resistance further. After potent knockdown of ASNS, cell viability in two doxorubicin-resistant cell lines MES/SA-DxR 2μM and MES/SA-DxR 8μM was decreased, as indicated by an MTT cell proliferation assay. By coupling two-dimensional differential gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry, proteins that play a vital role in ASNS signaling network and development of doxorubicin-induced resistance were identified. Among all the proteins that we have identified, GRP78 and AKR1C1 appear to be involved in drug resistance, replication factor C appears to participate in DNA repairing, and PP6C is proposed to play a role in cell cycle arrest.