title: Klotho suppresses growth and invasion of colon cancer cells through inhibition of IGF1R-mediated PI3K/AKT pathway.
abstract: Klotho (KL) was originally characterized as an aging suppressor gene, and has been identified as a tumor suppressor gene in a variety of cancers including colon cancer. However, the potential role and molecular events for KL in colon cancer remain unclear. The present study aimed to investigate the expression of KL in human colon cancer by immunohistochemistry, and to analyze the correlation between KL expression and clinicopathological characteristics of patients with colon cancer. Functional analysis after lentivirus-mediated gain of KL expression was used to assess the tumor growth and invasion in colon cancer cells in vitro and in vivo. The rate of KL expression was significantly decreased in cancer tissues compared with that in adjacent non-cancer tissues (ANCT) (60.3 vs.77.9%, P=0.022), and KL expression was negatively associated with Dukes staging (P=0.034) and depth of tumor invasion (P=0.008). Overexpression of KL in vitro inhibited cell proliferative activities and invasive potential in colon cancer cells, companied with decreased expression of p-IGF1R, p-PI3K, p-AKT, PCNA and MMP-2. In addition, the tumor volumes in the HT-29 subcutaneous tumor model treated with lentivirus‑mediated KL vector (Lv-KL) was significantly smaller than those of the negative control (NC) group (P<0.01). Taken together, our findings indicate that the expression of KL is downregulated in human colon caner and correlates with tumor invasion and Dukes staging, while overexpression of KL suppresses growth and invasion through inhibition of IGF1R-mediated PI3K/AKT pathway in colon cancer cells, suggesting that KL may serve as a potential therapeutic target for the treatment of colon cancer.
authors.affiliation: Department of Colorectal Surgery, Fudan University Shanghai Cancer Center and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China.
authors.forename: Xin-Xiang
authors.initials: XX
authors.lastname: Li
authors.affiliation: Department of Colorectal Surgery, Fudan University Shanghai Cancer Center and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China.
authors.forename: Li-Yong
authors.initials: LY
authors.lastname: Huang
authors.affiliation: Department of Colorectal Surgery, Fudan University Shanghai Cancer Center and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China.
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Peng
authors.affiliation: Department of Colorectal Surgery, Fudan University Shanghai Cancer Center and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Liang
authors.affiliation: Department of Colorectal Surgery, Fudan University Shanghai Cancer Center and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China.
authors.forename: De-Bing
authors.initials: DB
authors.lastname: Shi
authors.affiliation: Department of Colorectal Surgery, Fudan University Shanghai Cancer Center and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China.
authors.forename: Hong-Tu
authors.initials: HT
authors.lastname: Zheng
authors.affiliation: Department of Colorectal Surgery, Fudan University Shanghai Cancer Center and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, P.R. China.
authors.forename: San-Jun
authors.initials: SJ
authors.lastname: Cai
mesh_terms: D000368:Aged; D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis; D015153:Blotting, Western; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005966:Glucuronidase / Q000096:biosynthesis*; D064593:Heterografts; D006801:Humans; D007150:Immunohistochemistry; D000090265:Klotho Proteins; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D017526:Receptor, IGF Type 1 / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D005966:Glucuronidase; D000090265:Klotho Proteins; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D017526:Receptor, IGF Type 1