INTRODUCTION: Telomerase is an enzyme that is required for maintenance of telomeres. This enzyme has been shown to be present in germline tissues and majority of tumors and tumor cell lines. The regulation of telomerase is an area of active investigation in different models because, potentially, inhibition of this enzyme could be important in cancer therapy. To study the regulation of this enzyme in lymphoma cell lines, we used DMSO to produce a reversible G0/G1 arrest in Raji cell line, as shown earlier [Sawai M, Takase K, Teraoka H, Tsukada K. Reversible G1 arrest in the cell cycle of human lymphoid cell lines by dimethyl sulphoxide. Exp Cell Res 1990;187:4-10]. METHODS: In this study, we use a highly quantifiable conventional (non-amplified) assay to study the effect of DMSO on telomerase. In addition, we studied cellular proliferation and cell cycle profiles of the cells treated and, subsequently, released from DMSO induced blockage. RESULTS: In this model, DMSO reversibly inhibited telomerase activity that could be restored after release from the blockage. The inhibition of telomerase seems to parallel cellular proliferation and it appears that telomerase is regulated upon entry into the cell cycle. This view is consistent with other previously published views on relationship of telomerase with exit from cell cycle. CONCLUSION: Our observations demonstrate a novel effect of DMSO on cellular mechanisms in Raji cell line. It may provide an attractive model to further study regulation of telomerase in this cell line.
INTRODUCTION: Telomerase is an enzyme that is required for maintenance of telomeres. This enzyme has been shown to be present in germline tissues and majority of tumors and tumor cell lines. The regulation of telomerase is an area of active investigation in different models because, potentially, inhibition of this enzyme could be important in cancer therapy. To study the regulation of this enzyme in lymphoma cell lines, we used DMSO to produce a reversible G0/G1 arrest in Raji cell line, as shown earlier [Sawai M, Takase K, Teraoka H, Tsukada K. Reversible G1 arrest in the cell cycle of human lymphoid cell lines by dimethyl sulphoxide. Exp Cell Res 1990;187:4-10]. METHODS: In this study, we use a highly quantifiable conventional (non-amplified) assay to study the effect of DMSO on telomerase. In addition, we studied cellular proliferation and cell cycle profiles of the cells treated and, subsequently, released from DMSO induced blockage. RESULTS: In this model, DMSO reversibly inhibited telomerase activity that could be restored after release from the blockage. The inhibition of telomerase seems to parallel cellular proliferation and it appears that telomerase is regulated upon entry into the cell cycle. This view is consistent with other previously published views on relationship of telomerase with exit from cell cycle. CONCLUSION: Our observations demonstrate a novel effect of DMSO on cellular mechanisms in Raji cell line. It may provide an attractive model to further study regulation of telomerase in this cell line.