Reverse transcription-PCR analysis of laser-captured cells points to potential paracrine and autocrine actions of neurotrophins in pancreatic cancer.
OBJECTIVE
Neurotrophins (NTs) can stimulate cell proliferation and differentiation in various cell types, and play a role in certain human cancers. In this study we analyzed the expression and localization of NTs and their receptors in microdissected pancreatic cancer tissue samples, and studied their ability to stimulate cell growth.


METHODS
The expression of nerve growth factor, brain-derived neurotrophic factor, NT-3, and NT-4/5, and the receptors tropomyosin receptor kinase A, B, and C, and P75 was studied in pancreatic cancer cell lines, and normal and pancreatic ductal adenocarcinoma (PDAC) tissue samples by quantitative reverse transcription-PCR. Laser capture microdissection was performed in 21 PDAC samples, and mRNA levels were determined in cancer cells, acinar cells, desmoplastic stroma areas, and nerve fibers. Cell growth assays with NTs and in coculture with dorsal root ganglia were performed.


RESULTS
NT receptors were differentially expressed in the cancer cell lines, whereas tropomyosin receptor kinase C was not detectable. NTs modulated pancreatic cancer cell growth. Analysis of nonmicrodissected samples revealed that all of the receptors and tested ligands were overexpressed in PDAC when compared with normal pancreas. Analysis of laser captured samples revealed that NTs and their receptors were expressed in the cancer cells but were especially abundant in the intratumoral nerves. Coculture of dorsal root ganglia with T3M4 cells significantly enhanced the proliferation of this cell line.


CONCLUSIONS
The abundance of NTs in the intratumoral nerves in PDAC and the presence of NT receptors in the cancer cells, in conjunction with the ability of NTs to modulate pancreatic cancer cell growth, point to potential paracrine and autocrine effects of NTs in PDAC. Thus, our findings provide additional evidence that blocking NT actions may have a therapeutic potential in PDAC.
Ketterer
Knut
K
Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of California, Irvine, California 92697, USA.
Rao
Shyam
S
Friess
Helmut
H
Weiss
John
J
Büchler
Markus W
MW
Korc
Murray
M
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D019898:Autocrine Communication; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism; D044584:Carcinoma, Ductal / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002455:Cell Division; D018920:Coculture Techniques; D005727:Ganglia, Spinal / Q000378:metabolism; D006801:Humans; D007834:Lasers; D009412:Nerve Fibers / Q000378:metabolism; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism*; D020933:Neurotrophin 3 / Q000235:genetics / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D019899:Paracrine Communication; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020800:Receptor, Nerve Growth Factor; D020917:Receptor, trkA / Q000235:genetics / Q000378:metabolism; D020813:Receptor, trkB / Q000235:genetics / Q000378:metabolism; D020812:Receptor, trkC / Q000235:genetics / Q000378:metabolism; D017475:Receptors, Nerve Growth Factor / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000378:metabolism; D014407:Tumor Cells, Cultured
D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D020933:Neurotrophin 3; D012333:RNA, Messenger; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D020917:Receptor, trkA; D020813:Receptor, trkB; D020812:Receptor, trkC; C073922:neurotrophin 4