[CD44 expression patterns in primary and secondary brain tumors].

We investigated CD44 expression patterns in five types of primary brain tumors and brain metastases from more than ten organs by Northern blot, reverse transcription/polymerase chain reaction (RT/PCR) and immunocytochemical analyses. The results demonstrated that all of 72 primary brain tumors examined express standard form of CD44 (CD44s) but none of them express CD44v. In contrast, 22 of 26 brain metastases studied were found to express CD44v. Our data not only present a direct evidence of a general distribution of CD44 in primary brain tumors but also suggest that such expression is an extremely rare event in primary brain tumors. We conclude that CD44v may be a candidate marker for the evaluation of malignant potential of the tumors and the prognosis of cancer patients.