Lactate Induces Production of the tRNA(His) Half to Promote B-lymphoblastic Cell Proliferation
MOLECULAR THERAPY
Authors: Mo, Xiaohui; Du, Shujuan; Chen, Xiaoting; Wang, Yuyan; Liu, Xiaoqing; Zhang, Chongqi; Zhu, Caixia; Ding, Ling; Li, Ying; Tong, Yin; Ju, Qiang; Qu, Di; Tan, Fei; Wei, Fang; Cai, Qiliang
Abstract
High plasma lactate is emerging as a critical regulator in development and progression of many human malignancies. Small RNAs derived from cleavage of mature tRNAs have been implicated in many cellular stresses, but the detailed mechanisms that respond to lactic acid (LA; acidic lactate) are not well defined. Here, using an Epstein-Barr virus (EBV)-immortalized B lymphoblastic cell line (LCL) as a model, we report that LA induces cleavage of mature tRNA at the anticodon loop, particularly production of three 5'-tRNA halves (5'-His-GUG, 5'-ValAAC, and 5'-GlyGCC), along with increased expression of RNA polymerase III and angiogenin (ANG). Of these, only the 5'-HisGUG half binds to the chromatin regulator argonaute-2 (AGO2) instead of the AGO1 protein for stability. Notably, the levels of ANG and 5'-HisGUG half expression in peripheral blood mononuclear cells from B cell lymphoma patients are tightly correlated with lactate dehydrogenase (LDH; a lactate indicator) in plasma. Silencing production of the 5'-HisGUG half by small interfering RNA or inhibition of ANG significantly reduces colony formation and growth of LA-induced tumor cells in vitro and in vivo using a murine xenograft model. Overall, our findings identify a novel molecular therapeutic target for the diagnosis and treatment of B cell lymphoma.
Aberrant Expression of Prohibitin Is Related to Prognosis of Nasal Extranodal Natural Killer/T Cell Lymphoma, Nasal Type
ONCOLOGY RESEARCH AND TREATMENT
Authors: Guo, Wen Wen; Chen, Ling Hui; Yin, Wu; Mo, Lan Xiang
Abstract
Introduction:Nasal extranodal natural killer (NK)/T cell lymphoma, nasal type (ENKTCL) is a high-grade Epstein-Barr virus (EBV)-associated malignancy with poor outcomes. There are few biomarkers for the accurate diagnosis and prognostic prediction of the disease. The aim of this study was to investigate the clinicopathological significance of prohibitin (PHB) expression in nasal ENKTCL.Methods:The expression level of PHB was detected via immunohistochemical staining in 49 nasal ENKTCL tissues and age- and sex-matched controls of 30 nasal mucosa-reactive lymphoid hyperplasia (NRLH) tissues. The correlations between the PHB expression and clinicopathological features of patients with nasal ENKTCL were evaluated.Results:The results indicated a significantly decreased expression of PHB in nasal ENKTCL tissues compared with in NRLH tissues. Low-level PHB expression was significantly associated with younger age and fever (p= 0.008 and 0.018, respectively). The Kaplan-Meier analysis showed that the cytoplasm expression level of PHB in nasal ENKTCL was inversely related to overall survival (p= 0.046).Conclusions:PHB may be a potential diagnostic marker and prognostic predictor of nasal ENKTCL.