ABSTRACT
Cancer stem cells (CSCs) are associated with tumor progression, recurrence, and therapeutic resistance. To maintain their pool while promoting tumorigenesis, CSCs divide asymmetrically, producing a CSC and a highly proliferative, more differentiated transit-amplifying cell. Exhausting the CSC pool has been proposed as an effective antitumor strategy; however, the mechanism underlying CSC division remains poorly understood, thereby largely limiting its clinical application. Here, through cross-omics analysis, yin yang 2 (YY2) is identified as a novel negative regulator of CSC maintenance. It is shown that YY2 is downregulated in stem-like tumor spheres formed by hepatocarcinoma cells and in liver cancer, in which its expression is negatively correlated with disease progression and poor prognosis. Furthermore, it is revealed that YY2 overexpression suppressed liver CSC asymmetric division, leading to depletion of the CSC pool and decreased tumor-initiating capacity. Meanwhile, YY2 knock-out in stem-like tumor spheres caused enrichment in mitochondrial functions. Mechanistically, it is revealed that YY2 impaired mitochondrial fission, and consequently, liver CSC asymmetric division, by suppressing the transcription of dynamin-related protein 1. These results unravel a novel regulatory mechanism of mitochondrial dynamic-mediated CSCs asymmetric division and highlight the role of YY2 as a tumor suppressor and a therapeutic target in antitumor treatment.
Subject(s)
Liver Neoplasms , Mitochondrial Dynamics , Humans , Yin-Yang , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Cell Line , Neoplastic Stem Cells/metabolism , Transcription Factors/metabolismABSTRACT
BACKGROUND: Sorafenib is mainly used to treat patients with hepatocellular carcinoma (HCC) Barcelona Clinic Liver Cancer (BCLC) stage C, many of whom also have severe cirrhosis. However, hypersplenism and digestive tract hemorrhage are common complications of cirrhosis, which increase the risk and difficulty of treatment. METHODS: Nineteen patients with HCC BCLC stage C with hypersplenism were treated with sorafenib plus partial splenic embolism at Chongqing University Cancer Hospital, Chongqing, China, between January 2015 and June 2018. We analyzed the therapeutic effect and clinical safety of this treatment in these patients. RESULT: Hypersplenism was rectified in all patients. The incidence rates of hemorrhage and myelosuppression were 0%, and the mean survival time was 11.2 months. CONCLUSION: Sorafenib plus partial splenic embolism could relieve hypersplenism and prolong survival in patients with BCLC stage C HCC.