Researchers from the National Cancer Institute reported in the May 15 issue of Cancer Cell an in-depth study on the use of human glioblastoma stem cell lines as a research tool for studying brain cancers. The authors noted that freshly isolated glioblastoma cells grown in culture media containing serum result in the propagation of a heterogeneous population of cells with morphologies that are reminiscent of fibroblasts and epithelial cells. However, if the glioma cells were grown in serum-free culture media supplemented with bFGF and EGF, the cells were clonogenic and had the potential for multilineage differentiation. The scientists described these cells as tumor stem cells (TSCs). In contrast, glioma cells grown in serum lost its tumorigenic potential. It was further noted that primary glioblastoma isolates grown in culture "bear remarkable similarity to neural stem cells." These similarities were reflected in the studies in which the scientists demonstrated that TSCs grown in serum-free defined media had the ability to form neurospheres in vitro, the potential for unlimited self-renewal, the ability to terminally differentiate into glial and neuronal lineages, and gene expression profiles that were similar to normal neural stem cells. The authors proposed that studies on the natural history of cancer and its etiology should in the future consist of tissue assay systems where the TSCs or primary cancer tissue isolates are studied in culture conditions that do not contain serum. (It was proposed over a decade ago that cancer biologists were on the wrong track by using transformed cell lines to study various forms of cancers. Gerald B. Dermer, Ph.D. in his 1994 book, "The Immortal Cell: Why Cancer Research Fails" describes the failure of cancer research to recognize that using transformed cell lines to conduct cancer research was a path doomed for failure. Dermer noted that the transformed cells were artifacts and thus, the data being published were not meaningful with respect to cancer biology. Similarly, it should be noted that the above paper supports the concept that serum is a wound-healing inductive agent that leads to stem cell cultures giving rise to a heterogenous population of lineage committed cells.)