AIM To investigate the distribution of neuropeptide-immunoreactive nerve fibers in esophageal and cardiaccarcinoma as well as their relationship with tumor cells soas to explore if there is nerve innervation in esophageal andcardiac carcinoma.METHODS:Esophageal and cardiac carcinoma specimenswere collected from surgical operation.One part of themwere fixed immediately with 4 % paraformaldehyde andthen cut with a cryostat into 40-μm-thick sections to performimmunohistochemical analysis.Antibodies of ten kinds ofneuropeptide including calcitonin gene-related peptide(CGRP),galanin(GAL),substance P(SP),etc.were usedfor immunostaining of nerve fibers.The other part of thetumor specimens were cut into little blocks(1 mm~3)and co-cultured with chick embryo dorsal root ganglia(DRG)toinvestigate if the tumor blocks could induce the neurons ofDRG to extend processes,so as to probe into the possiblereasons for the nerve fibers growing into tumors.RESULTS:Substantial amounts of neuropeptide includingGAL-,NPY-,SP-immunoreactive nerve bundles and scatterednerve fibers were distributed in esophageal and cardiaccarcinomas.The scattered nerve fibers waved their way amongtumor cells and contacted with tumor cells closely.Some ofthem even encircled tumor cells.There were many varicositiesaligned on the nerve fibers like beads.They were also closelyrelated to tumor cells.In the co-culture group,about 63 %and 67 % of DRG co-cultured with esophageal and cardiactumor blocks respectively extended enormous processes,especially on the side adjacent to the tumor,whereas in thecontrol group(without tumor blocks),no processes grew out.CONCLUSION:Esophageal and cardiac carcinomas maybe innervated by peptidergic nerve fibers,and they caninduce neurons of DRG to extend processes in vitro. AIM To investigate the distribution of neuropeptide-immunoreactive nerve fibers in esophageal and cardiaccarcinoma as well as their relationship with tumor cells soas to explore if there is nerve innervation in esophageal and cardiac carcinoma. METHODS: Esophageal and cardiac carcinoma specimenswere collected from surgical operation. One part of themwere fixed immediately with 4% paraformaldehyde and then cut with a cryostat into 40-μm-thick sections to perform immunohistochemical analysis. Antibodies of ten kinds of uropeptide including calcitonin gene-related peptide (CGRP), galanin (GAL), substance P etc.were used for immunostaining of nerve fibers. the other part of the tumor of were cut into little blocks (1 mm ~ 3) and co-cultured with chick embryo dorsal root ganglia (DRG) to investigate if the tumor blocks could induce the neurons of DRG to extend processes, so as to probe into the possible reasons for the nerve fibers growing into tumors .RESULTS: Substantial amounts of neuropeptide inclu dingGAL-, NPY-, SP-immunoreactive nerve bundles and scatterednerve fibers were distributed in esophageal and cardiaccarcinomas. The scattered nerve fibers waved their way among tumor cells and contacted with tumor cells. Same of the even erupted tumor cells. There were many varicosities of signed on the nerve fibers like beads. They were also closelyrelated to tumor cells. In the co-culture group, about 63% and 67% of DRG co-cultured with esophageal and cardiactumor blocks respectively extended enormous processes, especially on the side adjacent to the tumor, while in thecontrol group (without tumor blocks), no processes grew out. CONCLUSION: Esophageal and cardiac carcinomas maybe innervated by peptidergic nerve fibers, and they can canuce neurons of DRG to extend processes in vitro.