DNA damage-induced genes in KMS12PE cells

The major histocompatibility complex class II (MHC II) is important for the adaptive immune response because it presents processed antigens to CD4-positive T-cells. Conventional chemotherapeutic agents (e.g., melphalan, adriamycin, hydroxyurea) induce tumor cell death by causing DNA double strand breaks (DSBs), which are crucial for anti-tumor effects. However, the cellular response induced at low doses of these agents that do not cause immediate cell death is unclear. We have employed microarray expression profiling to identify genes which are induced by low dose of chemotherapeutic agents. Multiple myeloma cell line KMS12PE was treated with vehicle, 2 μM melphalan, or 50 nM adriamycin. These agents transcriptionally induced the major histocompatibility complex class II (MHC II) genes. They also increased the expressions of MHC class II transactivator (CIITA), the master regulator of MHC II genes and interferon regulatory factor 1 (IRF1), a transcription factor for CIITA. We treated multiple myeloma cell line KMS12PE with vehicle, 2 μM melphalan or 50 nM adriamycin for 5 days