title: HAF drives the switch of HIF-1α to HIF-2α by activating the NF-κB pathway, leading to malignant behavior of T24 bladder cancer cells.
abstract: Hypoxia is a characteristic feature of solid tumors, leading to malignant behavior. During this process, HIF family members (HIFs) and the NF-κB pathway are activated. In addition, the hypoxia-associated factor (HAF) is reported to participate in the regulation of HIFs. However, the precise relationship among HIFs, HAF and the NF-κB pathway in bladder cancer (BC) remains unknown. In the current investigation, T24 BC cells were exposed to hypoxia, or by plasmid transfection to overexpress HAF or RelA (P65) to demonstrate their roles. The results indicate that hypoxia leads to the elevation of HAF plus activation of the NF-κB pathway, accompanied by the switch of HIF-1α to HIF-2α, resulting in the enhanced ability of malignancy in T24 cells. In order to further demonstrate the significance of this switch, HIF-1α and HIF-2α were co-transfected into T24 cells with HIF-β, respectively. The following results indicate that the T24hif-2α/β cells show enhanced ability of malignancy, accompanied by the maintenance of stem-cell markers, but the T24hif-1α/β cells show higher expression of metabolism-related genes. Boyden assays and wound-healing assays indicate the enhanced ability of malignancy for T24hif-2α/β. Thus, we conclude that on the hypoxic microenvironment, the switching of HIF-1α to HIF-2α, which is driven by HAF through activating the NF-κB pathway, contributes to the malignancy of T24 cells, accompanied by the maintenance of stem-cell markers. This provides us an avenue for understanding the progression of bladder cancer.
authors: Oncology Research Lab, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, P.R. China.
authors: Zhenfeng
authors: Z
authors: Guan
authors: Oncology Research Lab, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, P.R. China.
authors: Chen
authors: C
authors: Ding
authors: Oncology Research Lab, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, P.R. China.
authors: Yiqing
authors: Y
authors: Du
authors: Oncology Research Lab, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, P.R. China.
authors: Kai
authors: K
authors: Zhang
authors: Oncology Research Lab, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, P.R. China.
authors: Jian Ning
authors: JN
authors: Zhu
authors: Oncology Research Lab, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, P.R. China.
authors: Tingting
authors: T
authors: Zhang
authors: Department of Urology, The First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Xi'an, P.R. China.
authors: Dalin
authors: D
authors: He
authors: Oncology Research Lab, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, P.R. China.
authors: Shan
authors: S
authors: Xu
authors: Oncology Research Lab, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an, P.R. China.
authors: Xinyang
authors: X
authors: Wang
authors: Department of Urology, The First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Xi'an, P.R. China.
authors: Jinhai
authors: J
authors: Fan
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000502:physiology*; D002448:Cell Adhesion; D015687:Cell Hypoxia; D002465:Cell Movement; D058750:Epithelial-Mesenchymal Transition; D005455:Fluorescent Antibody Technique; D006801:Humans; D000860:Hypoxia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017411:Ribonucleoproteins, Small Nuclear; D014162:Transfection; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000378:metabolism / Q000473:pathology*; D014945:Wound Healing; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D002352:Carrier Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; D012333:RNA, Messenger; D017411:Ribonucleoproteins, Small Nuclear; D000099162:Endothelial PAS Domain-Containing Protein 1; C497442:HIF1A protein, human; C431323:SART1 protein, human