Growth of astrocytomas in the human tumor clonogenic assay and sensitivity to mismatched dsRNA and interferons.

Nine astrocytoma specimens were received from seven patients and processed for testing in the human tumor clonogenic assay (HTCA). Cells derived from these specimens were challenged with human natural alpha-interferon (alpha-IFN) and beta interferon (beta-IFN), recombinant beta interferon (beta ser-IFN), and mismatched double-stranded (ds) RNA (Ampligen). Six of the astrocytoma specimens formed adequate colonies for drug sensitivity testing (greater than or equal to 30 colonies/plate), and all were high-grade (III-IV) tumors.

Human neuroblastomas and abnormalities of chromosomes 1 and 17.

Structural rearrangements of chromosome 1p have been reported previously as a frequent finding in human neuroblastomas. In a review of karyotypes from 35 neuroblastomas (including 29 published cases and 6 unpublished tumors and cell lines), it was found that, in addition to the abnormalities of chromosome 1p (found in approximately 70% of cases), abnormalities involving only 2 other chromosome segments occurred with significant frequency (in 20% or more of cases) in this cancer. These abnormalities involved trisomies for the long arms of chromosomes 1 and 17.

Antiproliferative effect of natural beta interferon on fresh tumor cells analyzed in a clonogenic assay.

Natural beta interferon (beta IFN), derived from diploid fibroblasts, has been evaluated for its antiproliferative activity using a panel of twelve different histologic types of fresh human tumor cells. Thirty-nine percent (9/23) of the tumors showed a 70% or greater decrease in colony formation following exposure to 500 international reference units per ml of natural beta IFN, a concentration which is in the clinically achievable range. Interesting, is that leiomyosarcoma, a tumor relatively resistant to conventional chemotherapy, was uniformly sensitive (3/3) to natural beta IFN.