title: Invadopodia formation by bladder tumor cells.
abstract: A major cause of death in patients with bladder tumors is recurrence with metastasis. Bladder tumor metastasis is largely dependent upon the invasive capacity of tumor cells. Tumor cell invasion is mainly mediated by actin-rich protrusive membrane structures called invadopodia. The formation of invadopodia was observed in various types of invasive tumors such as breast cancer and melanomas. However, invadopodia formation so far has not been described in bladder tumor cells. We here report that human bladder tumor cells form functionally active invadopodia. By using a confocal laser scanning microscope, we demonstrated that invasive bladder tumor cell lines, YTS-1 and T24, with high Matrigel degradation activity form invadopodia but that noninvasive bladder tumor cell lines, RT4 and KK-47, form no detectable invadopodia. Invadopodia formed by YTS-1 cells had the ability to secrete matrix metalloproteases and degrade extracellular matrix to invade surrounding areas. Moreover, we observed that primary tumor cells obtained from patients with invasive bladder tumors also form invadopodia, validating the results from bladder tumor cell lines. Our results provide evidence that invasive human bladder tumor cells form invadopodia for tumor invasion.
authors.affiliation: Department of Biochemistry, Oyokyo Kidney Research Institute, Hirosaki, Aomori, Japan.
authors.forename: Mihoko
authors.initials: M
authors.lastname: Sutoh
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hashimoto
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yoneyama
authors.forename: Hayato
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Shingo
authors.initials: S
authors.lastname: Hatakeyama
authors.forename: Takuya
authors.initials: T
authors.lastname: Koie
authors.forename: Akiko
authors.initials: A
authors.lastname: Okamoto
authors.forename: Kanemitsu
authors.initials: K
authors.lastname: Yamaya
authors.forename: Hisao
authors.initials: H
authors.lastname: Saitoh
authors.forename: Tomihisa
authors.initials: T
authors.lastname: Funyu
authors.forename: Toshiya
authors.initials: T
authors.lastname: Nakamura
authors.forename: Tatsusuke
authors.initials: T
authors.lastname: Sato
authors.forename: Chikara
authors.initials: C
authors.lastname: Ohyama
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tsuboi
mesh_terms: D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000473:pathology; D005109:Extracellular Matrix / Q000502:physiology; D006801:Humans; D009361:Neoplasm Invasiveness; D001749:Urinary Bladder Neoplasms / Q000473:pathology*