Oncogenic Activity of Wrap53 in Human Colorectal Cancer In Vitro and in Nude Mouse Xenografts
MEDICAL SCIENCE MONITOR
Authors: Zhu, Yu; Ding, Lei; Chen, Bai-Feng; Song, Jian-Gen; Yao, Ying-Shui
Abstract
Background: WD40-encoding RNA antisense to p53 (Wrap53) has been implicated in cancer development. However, the role of Wrap53 remains unknown in colorectal cancer. The aim of this study was to elucidate the function of Wrap53 in colorectal cancer tumorigenesis and development. Material/Methods: This study analyzed Wrap53 expression in colorectal cancer tissue specimens using The Cancer Genome Atlas data and tumor cell lines and assessed the effects of Wrap53 knockdown on regulation of cancer cell malignant phenotypes in vitro and in nude mouse xenografts. Results: Wrap53 expression was upregulated in colorectal cancer tissue specimens and cell lines. Knockdown of Wrap53 expression induced colorectal cancer cell line apoptosis and cell cycle arrest in the G1 phase, but reduced tumor cell line proliferation and invasion in vitro. Knockdown of Wrap53 in a nude mouse xenograft assay inhibited tumor cell line xenograft formation and growth. Conclusions: Wrap53 is likely a potential oncogene or possesses oncogenic activity in colorectal cancer, promoting colorectal tumorigenesis. Targeting Wrap53 expression may represent a novel strategy for the control of colorectal cancer.
Nuclear expression of WRAP53 beta is associated with a positive response to radiotherapy and improved overall survival in patients with head and neck squamous cell carcinoma
ORAL ONCOLOGY
Authors: Garvin, Stina; Tiefenbock, Katharina; Farnebo, Lovisa; Thunell, Lena K.; Farnebo, Marianne; Roberg, Karin
Abstract
Objectives: Today there are no reliable predictive markers for radiotherapy response in head and neck squamous cell carcinoma (HNSCC), leading to both under-and over-treatment of patients, personal suffering, and negative socioeconomic effects. Inherited mutation in WRAP53 beta (WD40 encoding RNA Antisense to p53), a protein involved in intracellular trafficking, dramatically increases the risk of developing HNSCC. The purpose of this study was to investigate whether WRAP53 beta can predict response to radiotherapy in patients with HNSCC. Materials and methods: Tumor biopsies from patients with HNSCC classified as responders or non-responders to radiotherapy were examined for the expression of the WRAP53 beta protein and single nucleotide polymorphisms in the corresponding gene employing immunohistochemistry and allelic discrimination, respectively. In addition, the effect of RNAi-mediated downregulation of WRAP53 beta on the intrinsic radiosensitivity of two HNSCC cell lines was assed using crystal violet and clonogenic assays. Results: Nuclear expression of WRAP53 beta was significantly associated with better response to radiotherapy and improved patient survival. Downregulation of WRAP53 beta with siRNA in vitro enhanced cellular resistance to radiation. Conclusions: Our findings suggest that nuclear expression of WRAP53 beta promotes tumor cell death in response to radiotherapy and is a promising predictor of radiotherapy response in patients with HNSCC. (C) 2014 Elsevier Ltd. All rights reserved.