Progress in epigenetic modification of mRNA and the function of m6A modification / 生物工程学报

Messenger RNA (mRNA) can be modified by more than 100 chemical modifications. Among these modifications, N6-methyladenosine (m⁶A) is one of the most prevalent modifications. During the processes of cells differentiation, embryo development or stress, m⁶A can be modified on key mRNAs and regulate the progress of cells through modulating mRNA metabolism and translation. Other mRNA modifications, including N1-methyladenosine (m¹A), 5-methylcytosine (m⁵C) and pseudouridine, together with m⁶A form the epitranscriptome of mRNA that accurately modulate the mRNA translation. Here we review the types and characteristic of mRNA epigenetic modifications, especially the recent progresses of the function of m⁶A, we also expect the main research direction of m⁶A epigenetic modification in the future.

Relationship between osteopontin gene genetic polymorphisms and susceptibility of nasopharyngeal carcinoma in Guangxi Zhuang people / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate the relationship between osteopontin gene genetic polymorphisms and susceptibility of nasopharyngeal carcinoma in Guangxi Zhuang people.</p><p><b>METHODS</b>With a hospital based case-control study, osteopontin gene polymorphisms were compared between patients with nasopharyngeal carcinoma and healthy outpatients as a controls in Zhuang population in Guangxi. The single nucleotide polymorphisms at rs1126772 and rs9138 sites of the osteopontin gene were determined by polymerase chain reaction-single base extension technique (PCR-SBE) and DNA sequencing technology. The comparison between genotype and allele frequency distribution differences in case and control group was accomplished by a χ(2) test. The frequencies of haplotypes in osteopontin gene in different groups were analyzed.</p><p><b>RESULTS</b>There were no differences between the patients and controls in the genotype or allele frequencies of osteopontin gene rs1126772 site (</p><p><b>GA/GG</b>OR = 0.94, 95%CI 0.37-2.37, χ(2) = 0.182, P = 0.891; AA/GG:OR = 0.86, 95%CI 0.35-2.12, χ(2) = 0.834, P = 0.773) or rs9138 site (</p><p><b>CA/CC</b>OR = 1.42, 95%CI 0.88-2.29, χ(2) = 2.023, P = 0.155; AA/CC:OR = 1.77, 95%CI 0.78-4.01, χ(2) = 1.901, P = 0.168). The frequency of GA haplotype in the patients was significantly higher than that in the controls (P = 0.003), and the GA haplotype was associated with a significantly increased risk of nasopharyngeal carcinoma (OR = 4.84, 95%CI 1.59-14.71).</p><p><b>CONCLUSION</b>The haplotype GA of osteopontin gene rs1126772 and rs9138 sites increases the risk of nasopharyngeal carcinoma in Guangxi Zhuang people.</p>

Effect of nicotine intake on the periodontal tissue during orthodontic tooth movement / 中国组织工程研究

BACKGROUND:Cigarette smoking can seriously damage the periodontal tissues and root, and the nicotine in tobacco accelerates the progression of periodontal diseases. OBJECTIVE: To investigate the effect of different doses of nicotine on the expression of cyclooxygenase-2 mRNA in the periodontal tissue during orthodontic tooth movement. METHODS: Totaly 110 Sprague-Dawley rats were randomly divided into blank control group (n=10), normal saline group (n=25), 0.5 mg/kg nicotine group (n=25), 0.75 mg/kg nicotine group (n=25), 1 mg/kg nicotine group (n=25). Rats in the normal saline groups were injected intraperitonealy with 0.1 mL normal saline, and those in the three nicotine groups were respectively injected with 0.5, 0.75, 1 mg/kg nicotine tartrate solution. Except the blank control group, the unilateral maxilary first molars of rats in the other four groups were exposed to 50 g force. At 1, 3, 5, 7, 14 days under force, the rats were sacrificed to take the maxilary tissues. Hematoxylin-eosin staining was used to observe the changes of periodontal tissues, immunohistochemical staining was employed to count positive cels, andin situ hybridization staining was adopted to detect the mean absorbance value of cyclooxygenase-2 in the periodontal tissues. RESULTTS AND CONCLUSION:The number of odontoclasts and the expression of cyclooxygenase-2 in the nicotine groups were higher than those in the non-nicotine groups. With the increasing dose of nicotine, the number of odontoclasts gradualy increased, and the difference was statisticaly significant (P < 0.05). At 7 days under force, the number of odontoclasts reached the peak. With the increasing dose of nicotine, the positive expression intensity of cyclooxygenase-2 was also increased, and the difference was statisticaly significant (P < 0.05). The expression of cyclooxygenase-2 reached peak at 5 days under force. These findings indicate that with the increasing dose of nicotine, the number of odontoclasts and the expression intensity of cyclooxygenase-2 are both increased at the same time point under force. During the orthodontic tooth movement, the intake of nicotine can damage the periodontal tissue, and the dose of nicotine can directly influence the severity of damage to the periodontal tissue.