Expression of c-fos and c-myc in Raji Burkitt's lymphoma cells during the progression of DMSO-induced G1 cells into S phase.
Using flow cytometry, we have recently found that dimethyl sulfoxide (DMSO) reversibly induces G1-arrest in the cell cycle of human lymphoid cell lines such as Raji, Akata, and Molt-4. Here we investigated c-fos and c-myc expression in Raji Burkitt's lymphoma cells at DMSO-induced G1 arrest and after release from DMSO. A small but significant accumulation of c-fos mRNA was observed in G1-arrested Raji cells after treatment with 1.5% DMSO for 96 h. When G1-arrested Raji cells were transferred to DMSO-free medium, a transient increase in c-fos transcripts was detected 30-60 min after the release. The steady state level of c-myc transcripts in G1-arrested Raji cells was found to be one-third that in the log-phase cells. After removal of DMSO, the level of c-myc mRNA was restored and reached a maximum at 4.5-6 h. Immunoblot analysis with a monoclonal antibody against human c-myc protein indicated that c-myc protein in the G1-arrested cells was decreased less than one-tenth that in the log-phase cells. The level of c-myc protein gradually increased after the release from DMSO and reached a maximum at 6-9 h.
Teraoka
H
H
Department of Pathological Biochemistry, Tokyo Medical and Dental University, Japan.
Sawai
M
M
Takase
K
K
Yamamoto
K
K
Nozaki
N
N
Okazaki
T
T
Tsukada
K
K
D015152:Blotting, Northern; D015153:Blotting, Western; D002051:Burkitt Lymphoma / Q000235:genetics / Q000473:pathology*; D002453:Cell Cycle / Q000187:drug effects*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016760:Proto-Oncogene Proteins c-fos; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics
D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D004121:Dimethyl Sulfoxide