Zheng Wang1,2, Yujie Zhou1,2, Qi Han1, Xingchen Ye1, Yanyan Chen1,2, Yan Sun1,2, Yaqi Liu1,3, Jing Zou1,3, Guohai Qi4, Xuedong Zhou5,6, Lei Cheng7,8, Biao Ren9. 1. State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, 610041, China. 2. Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. 3. Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. 4. Radiotherapy Center, Sichuan Cancer Hospital, Chengdu, 610041, China. 5. State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, 610041, China. zhouxd@scu.edu.cn. 6. Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. zhouxd@scu.edu.cn. 7. State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, 610041, China. chenglei@scu.edu.cn. 8. Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China. chenglei@scu.edu.cn. 9. State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, Chengdu, 610041, China. renbiao@scu.edu.cn.
Abstract
BACKGROUND: The shift of oral microbiota is a critical factor of radiation caries in head and neck cancer patients after the radiotherapy. However, the direct effects of irradiation on the genome and virulence of cariogenic bacteria are poorly described. Here we investigated the genomic mutations and virulence change of Streptococcus mutans (S. mutans), the major cariogenic bacteria, exposed to the therapeutic doses of X-rays. RESULTS: X-ray reduced the survival fraction of S. mutans and impacted its biofilm formation. We isolated a biofilm formation-deficient mutant #858 whose genome only possessed three synonymous mutations (c.2043 T > C, c.2100C > T, c.2109A > G) in gtfB gene. The "silent mutation" of c.2043 T > C in gtfB gene can cause the down-regulation of all of the gtfs genes' expression and decrease the GtfB enzyme secretion without the effect on the growth due to the codon bias. #858 and synonymous point mutation strain gtfB 2043 T>C, similar to the gtfB gene null mutant Δ gtfB, can significantly decrease the extracellular polysaccharide production, biofilm formation and cariogenic capabilities both in vitro and in vivo compared with wild type. CONCLUSION: The direct exposure of X-ray radiation can affect the genome and virulence of oral bacteria even at therapeutic doses. The synonymous mutations of genome are negligent factors for gene expression and related protein translation due to the codon usage frequency.
BACKGROUND: The shift of oral microbiota is a critical factor of radiation caries in head and neck cancerpatients after the radiotherapy. However, the direct effects of irradiation on the genome and virulence of cariogenic bacteria are poorly described. Here we investigated the genomic mutations and virulence change of Streptococcus mutans (S. mutans), the major cariogenic bacteria, exposed to the therapeutic doses of X-rays. RESULTS: X-ray reduced the survival fraction of S. mutans and impacted its biofilm formation. We isolated a biofilm formation-deficient mutant #858 whose genome only possessed three synonymous mutations (c.2043 T > C, c.2100C > T, c.2109A > G) in gtfB gene. The "silent mutation" of c.2043 T > C in gtfB gene can cause the down-regulation of all of the gtfs genes' expression and decrease the GtfB enzyme secretion without the effect on the growth due to the codon bias. #858 and synonymous point mutation strain gtfB 2043 T>C, similar to the gtfB gene null mutant Δ gtfB, can significantly decrease the extracellular polysaccharide production, biofilm formation and cariogenic capabilities both in vitro and in vivo compared with wild type. CONCLUSION: The direct exposure of X-ray radiation can affect the genome and virulence of oral bacteria even at therapeutic doses. The synonymous mutations of genome are negligent factors for gene expression and related protein translation due to the codon usage frequency.
Authors: Joel B Epstein; Juliette Thariat; Rene-Jean Bensadoun; Andrei Barasch; Barbara A Murphy; Leanne Kolnick; Leslie Popplewell; Ellie Maghami Journal: CA Cancer J Clin Date: 2012-09-12 Impact factor: 508.702
Authors: Natália Rangel Palmier; César Augusto Migliorati; Ana Carolina Prado-Ribeiro; Maria Cecília Querido de Oliveira; Aljomar José Vechiato Filho; Mario Fernando de Goes; Thais Bianca Brandão; Marcio Ajudarte Lopes; Alan Roger Santos-Silva Journal: Oral Surg Oral Med Oral Pathol Oral Radiol Date: 2020-05-19
Authors: Caique Mariano Pedroso; Cesar Augusto Migliorati; Joel B Epstein; Ana Carolina Prado Ribeiro; Thaís Bianca Brandão; Márcio Ajudarte Lopes; Mário Fernando de Goes; Alan Roger Santos-Silva Journal: Front Oral Health Date: 2022-07-14