Primary central nervous system non-Hodgkin's lymphoma (PCNSL): survival advantages with combined initial therapy? A final report of the North Central Cancer Treatment Group (NCCTG) Study 86-72-52.

PURPOSE: We herein report updated survival and toxicity data on the entire cohort of 53 eligible patients treated on North Central Cancer Treatment Group (NCCTG) protocol 86-72-52, which is now closed. METHODS AND MATERIALS: An initial report was published in this journal in 1995. No substantive changes in the conclusions of that report were identified in this analysis. Median survival was 9.6 months for the entire cohort; median survival for the 20 patients who completed the prescribed protocol treatment was 20.7 months. The hematologic and non-hematologic toxicity distributions are virtually the same as those reported in the original paper. RESULTS: Results are given for the entire group and for subsets defined by age < or = 60 versus > 60 years, and < 70 versus > or = 70 years of age. CONCLUSIONS: No significant differences were observed in any of the outcome variables by age group. There was, however, a nonsignificant suggestion of poorer outcome in those who were > 60 years of age.

Multiple cis-acting sequence elements are required for efficient splicing of simian virus 40 small-t antigen pre-mRNA.

We have determined the effects of a number of mutations in the small-t antigen mRNA intron on the alternative splicing pattern of the simian virus 40 early transcript. Expansion of the distance separating the small-t pre-mRNA lariat branch point and the shared large T-small t 3' splice site from 18 to 29 nucleotides (nt) resulted in a relative enhancement of small-t splicing in vivo. This finding, coupled with the observation that large-T pre-RNA splicing in vitro was not affected by this expansion, suggests that small-t splicing is specifically constrained by a short branch point-3' splice site distance. Similarly, the distance separating the 5' splice site and branch point (48 nt) was found to be at or near a minimum for small-t splicing, because deletions in this region as small as 2 nt dramatically reduced the ratio of small-t to large-T mRNA that accumulated in transfected cells. Finally, a specific sequence within the small-t intron, encompassing the upstream branch sites used in large-T splicing, was found to be an important element in the cell-specific pattern of early alternative splicing. Substitutions within this region reduced the ratio of small-t to large-T mRNA produced in HeLa cells but had only minor effects in human 293 cells.