title: Tumor-stromal interactions with direct cell contacts enhance proliferation of human pancreatic carcinoma cells.
abstract: Pancreatic ductal adenocarcinoma is often characterized by an abundant desmoplastic stroma that is partially induced by activated pancreatic stellate cells (PSCs). Indirect co-culture has often been used to investigate the effects of cancer-stromal interactions on the proliferation of cancer cells, but the effects of cell-cell adhesion and juxtacrine signaling between cancer and stromal cells cannot be evaluated using this method. This study aimed to establish a simplified direct co-culture system that could be used to quantify populations of cancer cells in co-culture with PSCs, and to evaluate the effects of direct cell contact on the proliferation of cancer cells. We established three green fluorescent protein (GFP)-expressing pancreatic cancer cell lines and were able to quantify them with high reliability and reproducibility, even when co-cultured directly with PSCs, using a color plate reader. We assessed the differential effects of direct and indirect co-culture with PSCs on the proliferation of cancer cells, and found that the proliferation of GFP-expressing pancreatic cancer cell lines was dramatically enhanced by direct co-culture with PSCs, compared with the indirect co-culture system. We also found that direct co-culture of cancer cells and PSCs activated the Notch signaling pathway in both cell types. Direct cell contact between cancer cells and PSCs plays an important role in the control of cancer cell proliferation, and is essential to the understanding of tumor-stromal interactions.
authors.affiliation: Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Fujita
authors.forename: Kenoki
authors.initials: K
authors.lastname: Ohuchida
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Mizumoto
authors.forename: Takuya
authors.initials: T
authors.lastname: Egami
authors.forename: Kei
authors.initials: K
authors.lastname: Miyoshi
authors.forename: Taiki
authors.initials: T
authors.lastname: Moriyama
authors.forename: Lin
authors.initials: L
authors.lastname: Cui
authors.forename: Jun
authors.initials: J
authors.lastname: Yu
authors.forename: Ming
authors.initials: M
authors.lastname: Zhao
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Manabe
authors.forename: Masao
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D000199:Actins / Q000235:genetics; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000473:pathology*; D002450:Cell Communication; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D024042:Collagen Type I / Q000235:genetics; D006801:Humans; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000032:analysis; D051881:Receptor, Notch1 / Q000502:physiology; D015398:Signal Transduction; D017154:Stromal Cells / Q000502:physiology
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D024042:Collagen Type I; C497761:NOTCH1 protein, human; D012333:RNA, Messenger; D051881:Receptor, Notch1