title: Cancer-associated fibroblasts induce cancer cell apoptosis that regulates invasion mode of tumours.
abstract: In the process of cancer spreading, different modes of invasion exist. One is expansive invasion, in which a group of cancer cells gradually expands along with cancer cell proliferation. Invasion of cancer cells is also modified by their interaction with stromal cells including cancer-associated fibroblasts (CAFs). Cancer cells co-invade with CAFs, and invasion by CAFs frequently precede invasion by cancer cells, which indicates CAF-led cancer cell invasion. Here, we show that CAFs induce apoptosis in gastric cancer cells, which prevented expansive invasion by cancer cells and instead facilitated CAF-led invasion. Death receptor 4 and activation of caspase-8 in cancer cells mediated cancer cell apoptosis induced by CAFs, which was dependent on contact between cancer cells and CAFs. Apoptotic cancer cells in turn released apoptotic vesicles and stimulated invasion of CAFs. Accordingly, cancer cells followed the migrating CAFs. Treatment with a caspase inhibitor, ZVAD, or forced expression of a death domain fragment in cancer cells prevented cancer cell apoptosis induced by CAFs and increased expansive invasion by cancer cells in extracellular gel invasion assays, while the rate of cancer cell invasion led by CAFs was decreased. Death domain-fragment expression also prevented intramural invasion by gastric cancer cells in the stomach. Because CAF-led invasion is characterized by the movement of individual cancer cells away from the tumour, adequate cancer cell apoptosis may promote cancer dissemination.
authors.affiliation: Department of Molecular Medicine and Biochemistry, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: G
authors.initials: G
authors.lastname: Itoh
authors.affiliation: Bioscience Education and Research Support Center, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Chida
authors.affiliation: Division of Pathology, Exploratory Oncology Research &Clinical Trial Center, National Cancer Center, Chiba, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yanagihara
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Abeno-ku, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yashiro
authors.affiliation: Department of Molecular Medicine and Biochemistry, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Aiba
authors.affiliation: Department of Molecular Medicine and Biochemistry, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D017209:Apoptosis; D000072645:Cancer-Associated Fibroblasts / Q000502:physiology*; D053181:Caspase 8 / Q000502:physiology; D002450:Cell Communication; D045744:Cell Line, Tumor; D000067128:Extracellular Vesicles / Q000502:physiology; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D009361:Neoplasm Invasiveness; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000502:physiology; D013274:Stomach Neoplasms / Q000473:pathology*
chemical_list: D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053181:Caspase 8