Can permanent cell lines originate from low-grade astrocytomas: overgrowth of “glia-like“ cells in pilocytic and fibrillary (diffuse) astrocytoma cultures

Abstract

OBJECTIVES: Due inter alia to wide-spread cell lines cross-contamination it is not clear, which kind of normal or tumoral tissue give rise to permanent cell lines. BACKROUND: Few permanent cell lines have been established from low-grade astrocytomas. However, recently some of these have been identifi ed as being cross-contaminated with other cell lines. METHODS: Morphology, cell growth and GFAP immunophenotype of low-grade astrocytomas were examined on 9 pilocytic and 15 fi brillary (diffuse) tissue cultures. RESULTS: GFAP-positive process-bearing cells were present in all the cultures, mainly during the fi rst days in vitro (DIV). In pilocytic cultures, cells with hairy (piloid) processes were present. GFAP-positive cells completely disappeared by passages 3 to 5 and all the cultures contained only GFAP-negative "glia-like" cells, which underwent cellular senescence within passages 8 to 15. CONCLUSION: Key differences in the morphology and GFAP expression between the neoplastic astrocytes and normal "glia-like" cells allow the observation of perceptibly more rapid growth of normal cells in astrocytoma cultures. We caution that cultures prepared from macroscopically tumoral brain tissue may contain rapidly proliferating normal cells. Based on this and our previous studies in relation to the high percentage of cross-contaminated cell lines, we conclude that cells in low-grade astrocytoma cultures lack the capacity for spontaneous immortalization (Fig. 14, Ref. 15).