title: C4.4A is associated with tumor budding and epithelial-mesenchymal transition of colorectal cancer.
abstract: C4.4A is a glycolipid-anchored membrane protein expressed in several human malignancies. The aim of this study was to explore the association between C4.4A expression at the invasion front of colorectal cancer (CRC) and tumor budding, a putative hallmark of cell invasion of CRC. Advanced CRCs (T2-4, n = 126) had a budding count of 3.66 ± 5.66, which was significantly higher than that of T1 early CRCs (1.75 ± 2.78, n = 87). C4.4A-positive CRC specimens showed a larger budding cell number than C4.4A-negative CRC specimens in T1 CRCs, and especially advanced CRCs (9.45 ± 5.83 vs 1.60 ± 3.93). Furthermore, we found a correlation between the percentage of C4.4A-positive cases and budding count in advanced CRC. Multivariate analysis for patients' survival showed that C4.4A was superior to tumor budding as a prognostic factor. With siRNA treatment, C4.4A levels were associated with cell invasion, but not with proliferation, in HCT116 and DLD1 cell lines. An immunohistochemical study in a subset of CRCs showed no relationship between C4.4A and Ki-67 proliferation marker. In vitro assays using HCT116 indicated that C4.4A levels correlated well with epithelial-mesenchymal transition (EMT) with regard to cell morphology and alterations of EMT markers including E-cadherin, vimentin, and partially N-cadherin. We also found that C4.4A expression was significantly associated with loss of E-cadherin and gain of β-catenin in clinical CRC tissue samples. These findings suggest that a tight association between C4.4A and tumor budding may, in part, be due to C4.4A promoting EMT at the invasive front of CRC.
authors.affiliation: Department of Surgery, Gastroenterological Surgery, Graduate School of Medicine, Osaka University, Osaka, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Oshiro
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Masahisa
authors.initials: M
authors.lastname: Ohtsuka
authors.forename: Xin
authors.initials: X
authors.lastname: Wu
authors.forename: Junichi
authors.initials: J
authors.lastname: Nishimura
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takemasa
authors.forename: Tsunekazu
authors.initials: T
authors.lastname: Mizushima
authors.forename: Masataka
authors.initials: M
authors.lastname: Ikeda
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Sekimoto
authors.forename: Nariaki
authors.initials: N
authors.lastname: Matsuura
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Doki
authors.forename: Masaki
authors.initials: M
authors.lastname: Mori
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D015820:Cadherins / Q000096:biosynthesis; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D058750:Epithelial-Mesenchymal Transition; D058851:GPI-Linked Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D019394:Ki-67 Antigen / Q000096:biosynthesis; D008565:Membrane Proteins / Q000096:biosynthesis; D009361:Neoplasm Invasiveness; D011379:Prognosis; D034622:RNA Interference; D034741:RNA, Small Interfering; D014746:Vimentin / Q000096:biosynthesis; D051176:beta Catenin / Q000096:biosynthesis
chemical_list: D014408:Biomarkers, Tumor; D015820:Cadherins; D015815:Cell Adhesion Molecules; D058851:GPI-Linked Proteins; D019394:Ki-67 Antigen; C472589:LYPD3 protein, human; D008565:Membrane Proteins; D034741:RNA, Small Interfering; D014746:Vimentin; D051176:beta Catenin