Specific expression of the ras-related rab3A gene in human normal and malignant neuroendocrine cells.

The authors originally demonstrated the tissue-specific expression of the rab3A gene in the mouse brain. In the current study, they analyze the activity of this gene in fresh human tumors associated with neuronal phenotype compared with normal and malignant cells from other origins.,The authors studied the transcription levels of the rab3A gene by Northern blot in 81 fresh tumors.,A high rab3A gene expression was observed in tumor samples derived from the neural tube (i.e., neuroblastomas, ganglioneuroblastomas, and adult nervous system neoplasms). In addition, this tissue-specific expression extended to neuroendocrine tumors of the gut, small cell lung cancers, and pheochromocytomas.,These results suggest a specific restriction pattern to human cells derived from the neural tube and neural crests. The GTP/GDP-binding rab3A protein may be a useful differentiation marker of neuro-endocrine cells in the characterization of undifferentiated neoplasms.