Chia-Ming Liu1, Cheng-Chia Yu2, Taichen Lin1, Yi-Wen Liao3, Pei-Ling Hsieh4, Chuan-Hang Yu5, Shiuan-Shinn Lee6. 1. School of Dentistry, Chung Shan Medical University, Taichung, Taiwan; Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan. 2. School of Dentistry, Chung Shan Medical University, Taichung, Taiwan; Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan; Institute of Oral Sciences, Chung Shan Medical University, Taichung, Taiwan. 3. School of Dentistry, Chung Shan Medical University, Taichung, Taiwan; Department of Medical Research, Chung Shan Medical University Hospital, Taichung. 4. Department of Anatomy, School of Medicine, China Medical University, Taichung, Taiwan. 5. School of Dentistry, Chung Shan Medical University, Taichung, Taiwan; Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan. Electronic address: tao2008@csmu.edu.tw. 6. Department of Public Health, Institute of Public Health, Chung Shan Medical University, Taichung, Taiwan. Electronic address: shinn@csmu.edu.tw.
Abstract
BACKGROUND/ PURPOSE: Oral cancer is amongst the most prevalent cancers worldwide with rising incidence. Various attempts have been made to elucidate its pathogenesis, and we sought to examine the function of a ubiquitin E3 ligase that was encoded by STUB1. METHODS: The mRNA expression of STUB1 in oral cancer samples and normal counterparts was determined by qRT-PCR. Numerous assays to assess the features of cancer cells, including self-renewal capacity, invasion and migration abilities were conducted following knockdown or overexpression of STUB1. RESULTS: The expression level of STUB1 was reduced in oral cancer, which was associated with a reduced relapse-free survival. Two oral cancer cell lines with low expression of STUB1 (SAS and HSC3) were chosen for the overexpression of STUB1. We showed that ectopic expression of STUB1 led to the downregulation of TGM2, a multifunctional protein that contributed to cancer progression in several cancers. Our results demonstrated that overexpression of STUB1 suppressed the cancer aggressiveness, while restoration of TGM2 reverted the effects. Last, we showed that STUB1 silencing resulted in enhanced cancer features. CONCLUSION: The abnormal downregulation of STUB1 may lessen its suppressive effect on TGM2, which induced the onset or exacerbated the progression of oral cancer. The therapeutic approach to enhance the expression of STUB1 could be a promising direction for cancer therapy.
BACKGROUND/ PURPOSE: Oral cancer is amongst the most prevalent cancers worldwide with rising incidence. Various attempts have been made to elucidate its pathogenesis, and we sought to examine the function of a ubiquitin E3 ligase that was encoded by STUB1. METHODS: The mRNA expression of STUB1 in oral cancer samples and normal counterparts was determined by qRT-PCR. Numerous assays to assess the features of cancer cells, including self-renewal capacity, invasion and migration abilities were conducted following knockdown or overexpression of STUB1. RESULTS: The expression level of STUB1 was reduced in oral cancer, which was associated with a reduced relapse-free survival. Two oral cancer cell lines with low expression of STUB1 (SAS and HSC3) were chosen for the overexpression of STUB1. We showed that ectopic expression of STUB1 led to the downregulation of TGM2, a multifunctional protein that contributed to cancer progression in several cancers. Our results demonstrated that overexpression of STUB1 suppressed the cancer aggressiveness, while restoration of TGM2 reverted the effects. Last, we showed that STUB1 silencing resulted in enhanced cancer features. CONCLUSION: The abnormal downregulation of STUB1 may lessen its suppressive effect on TGM2, which induced the onset or exacerbated the progression of oral cancer. The therapeutic approach to enhance the expression of STUB1 could be a promising direction for cancer therapy.