Objecfive Most prostate cancer contains two or more widely separate turnors.To study the origin of prostate cancer based on the analysis of microsatellite alteration in separate tumors from the same prostate.Methods A polymerase chain reaction (PCR) was used to examine the allelic loss pattern of 4 microsatellite polymorphic markers on chromosome 8p (D8S133,D8S136,D8S137) and 17q (D17S855) in multifocal tumors of prostate from 19 patients.DNA samples were obtained from different regions of distinctly separate tumors on single case using microdissection technique.Results The overall frequence of LOH at D8S133,D8S136,D8S137 and D17S855 for all informative cases was 74%,38%,86% and 46%respectively in 40 separate tumors of prostate from 19 patients.The pattern of allelic loss was not identical in 15 of 18 (83%) informative cases. It showed that the different regions of prostate cancer were independent origin respectively.Discordant pattern of histology was observe in distantly separate regions.whereas the same allele was consistently lost in samples from different regions of the same tumor in 3 cases. Condusion Current data supports independent origin of multiple tumors in most prostate cancer patients.

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia(ALSP)is a clinically rare autosomal dominant genetic disease,and its specific pathogenesis is not yet clear.The colony-stimulating factor 1 receptor(CSF1R)is a transmembrane tyrosine kinase receptor on the cell surface and mutations in the gene encoding it have been identified as potential pathogenic factors for ALSP.However,the specific mechanisms by which CSF1R gene mutations lead to the onset of ALSP are still unclear.After reviewing the mutation sites and pathogenic mechanisms of CSF1R in the pathogenesis of ALSP,CSF1R mutations have been shown to cause microglial dysfunction through mechanisms such as dominant-negative effects,loss of function,haploinsufficiency,and gain of function,thereby leading to the onset of ALSP.A deeper understanding of the causes of ALSP will help in exploring potential treatment methods.