Thymidine kinase 1 (TK1),an enzyme of the pyrimidine remedial pathway,can catalyze phosphorylation of thymidine to thymidine monophosphate.It is closely related to cell cycle regulation and cell proliferation.A number of experiments show that TK1 can be used for physical examination,tumor screening,routine testing,effect monitoring and prognosis evaluation,which is considered to be a sensitive and useful marker for human tumor growth.

Nasopharyngeal carcinoma(NPC)is one of the most common malignant tumors of the head and neck.The therapies for nasopharyngeal carcinoma include the following aspects:conventional radiotherapy,chemotherapy,surgery and molecular target therapy,etc.The combined chemo-radiotherapy and molecular target therapy has gradually become the hotspot therapy for NPC.

Objective To explore the combined effects of fluoride and arsenite on the expression of Runx-related transcription 2 (Runx2) mRNA in bone of Sprague Dawley (SD) rats.Methods Fifty four SD rats were selected[body mass(109.71 ± 10.52)g,half male and half female].3 × 3 Factorial experimental design was used to evaluate the combined effects of fluoride and arsenite on the expression of Runx2 mRNA by random number talbe.Rats were exposed to NaF,NaAsO2 and NaF plus NaAsO2 for 6 months by oral perfusion at gradient doses,respectively:the control group(0 mg/kg NaF + 0.0 mg/kg NaAsO2),the low fluoride group(5 mg/kg NaF),the high fluoride group(20 mg/kg NaF),the low arsenite group(2.5 mg/kg NaAsO2),the high arsenite group(10.0 mg/kg NaAsO2),the low fluoride low arsenite group(5 mg/kg NaF + 2.5 mg/kg NaAsO2),the high fluoride low arsenite group(20 mg/kg NaF + 25 mg/kg NaAsO2),the low fluoride high arsenite group(5 mg/kg NaF + 10.0 mg/kg NaAsO2) and the high fluoride high arsenite group(20 mg/kg NaF + 10.0 mg/kg NaAsO2).The expression of Runx2 mRNA was determined by quantitative real-time RT-PCR.Results The expressions of Runx2 mRNA in the control,low fluoride,high fluoride,low arsenite,high arsenite,low fluoride low arsenite,low fluoride high arsenite,high fluoride low arsenite and high fluoride high arsenite groups were 1.024 ± 0.015,1.377 + 0.014,1.587 ± 0.012,1.182 ± 0.015,1.343 ± 0.010,1.444 ± 0.019,1.504 ± 0.013,1.608 ± 0.013 and 1.714 + 0.009,respectively.The expressions of Runx2 mRNA in experimental groups were higher than those in control group (all P ＜ 0.05),fluoride and arsenite were positively correlated with the expression of Runx2 mRNA(all P ＜ 0.01),and there was a dose-response relationship between Runx2 mRNA and fluoride-arsenite levels.Factorial analysis showed that fluorine or arsenic alone could affect the expression level of Runx2(F =46.967,8.317,all P ＜ 0.05),and there was a interaction between fluorine and arsenic to the expression of Runx2 mRNA (F =105.271,P ＜ 0.01).Conclusion Fluoride or arsenic could promote the expression of Runx2 mRNA in bone of rats; there is an interaction between fluorine and arsenic to the expression of Runx2 mRNA.

Objective:To explore the significance of the clinical target volume (CTV) dose optimization in the upper and middle neck in protecting the laryngopharynx, anterior and posterior rings during intensity-modulated radiotherapy (IMRT) and multimodal imaging system for nasopharyngeal carcinoma.Methods:Clinical data of 298 nasopharyngeal carcinoma patients admitted to Jiangsu Cancer Hospital from 2016 to 2018 were retrospectively analyzed. According to the following five strategies of CTV dose optimization in the upper and middle neck: group A, complete optimization of bilateral cervical lymph nodes (CLNs), that is, the CTV doses of bilateral CLNs were 50.4 Gy; group B, complete optimization of unilateral CLNs, that is, the CTV dose of unilateral CLNs was 50.4 Gy and the contralateral CLNs was 60 Gy; group C, incomplete optimization of bilateral CLNs, that is, the CTV doses of bilateral CLNs were 50.4 Gy, while the suspicious positive CLNs were selectively boosted to 60 Gy; group D, incomplete optimization of unilateral CLNs, that is, the CTV dose of unilateral CLNs was 50.4 Gy and the suspicious positive CLNs were selectively boosted to 60 Gy, and the CTV dose of contralateral side was 60 Gy; group E: no optimization, that is, the CTV doses of bilateral CLNs were 60 Gy.Results:Among 298 patients, 215 patients received dose optimization and 83 cases did not receive dose optimization. In the dose optimization schemes, 114 cases were assigned in group A, 36 cases in group B, 60 cases in group C and 5 cases in group D. The median (range) follow-up time was 28.5(6.0-46.3) months. The overall survival rate was 95.6%, the progression-free survival rate was 84.2% and the locoregional control rate of CLNs was 98.0%. Local relapse of CLNs occurred in six patients, including 1 case of retropharyngeal lymph node, 4 cases of Ⅱ area and 1 case of Ⅳ area. The P values of average dose of laryngopharynx in group A, group B, group C and group D compared with that in group E were<0.001, 0.016, 0.001 and 0.572, respectively. The P values of the average dose of the anterior ring in group A, group B, group C and group D compared with that in group E were<0.001, 0.011, <0.001 and 0.805, respectively. The P values of the average dose of the posterior ring in group A, group B, group C and group D compared with that in group E were<0.001, 0.004, <0.001 and 0.252, respectively.Conclusions:Combined with the metastatic rules of CLNs and multimodal imaging system, it is safe to optimize the CTV dose of the upper and middle neck during IMRT in nasopharyngeal carcinoma patients, which can significantly reduce the doses of laryngopharynx, anterior and posterior rings, thereby providing evidence for reducing the CTV dose in the upper and middle neck.