HIF1α regulates single differentiated glioma cell dedifferentiation to stem-like cell phenotypes with high tumorigenic potential under hypoxia

// Pan Wang 1 , Chuan Lan 1 , Shuanglong Xiong 2 , Xiuwen Zhao 1 , You’an Shan 1 , Rong Hu 1 , Wenwu Wan 1 , Shuangjiang Yu 1 , Bin Liao 1 , Guangzhi Li 1 , Junwei Wang 1 , Dewei Zou 1 , Bing Chen 3 , Hua Feng 1 , Nan Wu 1 1 Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing 400038, China 2 Department of Oncology, Cancer Hospital, Chongqing 400030, China 3 Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400038, China Correspondence to: Nan Wu, email: wunan881@tmmu.edu.cn Keywords: glioblastoma multiforme, hypoxia, dedifferentiation, glioma stem cell, HIF1α Received: April 10, 2016      Accepted: February 20, 2017      Published: March 03, 2017 ABSTRACT The standard treatment for Glioblastoma multiforme (GBM) is surgical resection and subsequent radiotherapy and chemotherapy. Surgical resection of GBM is typically restricted because of its invasive growth, which results in residual tumor cells including glioma stem cells (GSCs) and differentiated cells. Recurrence has been previously thought to occur as a result of these GSCs, and hypoxic microenvironment maintains the GSCs stemness also plays an important role. Summarizing traditional studies and we find many researchers ignored the influence of hypoxia on differentiated cells. We hypothesized that the residual differentiated cells may be dedifferentiated to GSC-like cells under hypoxia and play a crucial role in the rapid, high-frequency recurrence of GBM. Therefore, isolated CD133 – CD15 – NESTIN – cells were prepared as single-cell culture and treated with hypoxia. More than 95% of the surviving single differentiated CD133 – CD15 – NESTIN – cell dedifferentiated into tumorigenic CD133 + CD15 + NESTIN + GSCs, and this process was regulated by hypoxia inducible factor-1α. Moreover, the serum also played an important role in this dedifferentiation. These findings challenge the traditional glioma cell heterogeneity model, cell division model and glioma malignancy development model. Our study also highlights the mechanism of GBM recurrence and the importance of anti-hypoxia therapy. In addition to GSCs, residual differentiated tumor cells also substantially contribute to treatment resistance and the rapid, high recurrence of GBM.