Objective To study the altered radiobiological effect of simulative intensity-modulated radiotherapy (SIMR) in cultured human nasopharyngeal carcinoma (NPC) cells and the related mechanism. Methods Single cell suspension of exponentially growing CNE-2 cells, a poor differentiated NPC cell line, was seeded and cultured for 12 hours, then the cells were irradiated in two different models by 6 MV X-ray beams at 3 Gy/min. In single fraction irradiation (SFR) model, cells were irradiated a single fraction of 0, 2, 4, 6 or 8 Gy within 0 to 3 minutes. In S1MR model, cells were irradiated 0, 2, 4, 6 or 8 Gy in 5 frac-tions with interval of 8.0-8.5 minutes between. Clonogenic assay was performed to determine the radiosen-sitivity. Cellular apoptosis was measured by flow cytometry. RT-PCR was used to detect mRNA expressions of Bax and Bcl-2, Respectively. Results Compared with SFR group, the survival fraction in SIMR group was higher at all the dose levels. The values of α, β, D0 and Dq were higher in SIMR group than in SFR group. At dose levels of 2 Gy, 4 Gy and 6 Gy, The early and late apoptotic cells in SIMR group were lower than in SFR group (21.20%: 15.89%, F=18.51, P=0.020;13.00%: 10.20, F=15.67, P=0.040).The mRNA expression of Bax was upregulated in a dose-dependent manner in the both groups. Compared with SFR group, the mRNA expression of Bax in SIMR group was lower at all the dose levels (Mean value of 76.75% : 62.50%, F =36.57, P =0.000). Bcl-2 mRNA expression at every dose level had no significant difference between the two groups (Mean value of 29.25% : 29.75%, F=0.74, P=0.800). Conclusions Prolonged delivery time in SIMR model can decrease the radiobiological effects.

Background and purpose:Multiple microRNAs (miRNAs) are abnormally expressed in breast cancer and play an important role in the regulation of breast cancer. miRNAs may be a new target for the treatment of breast cancer. This study aimed to investigate the expression of miR-199a-3p in breast cancer and the effect of miR-199a-3p on proliferation and apoptosis of breast cancer.Methods:Real-time PCR was used to test the expression of miR-199a-3p in breast cancer tissues, normal breast tissues, breast cancer cells and normal breast cells. Overexpression (or silencing the expression) of miR-199a-3p was conducted by transfecting MDA-MB-231 with miR-199a-3p mimics (or inhibitors). The proliferation of MDA-MB-231 was detected by MTT method. The apoptosis of MDA-MB-231 was investigated by Hoechst staining and caspase-3 activity assay kit.Results:Compared to corresponding non-tumor breast tissues (or normal breast cell HBL-100), lower levels of miR-199a-3p were expressed in breast cancer tissues or breast cancer cells. Overexpression of miR-199a-3p induced by miR-199a-3p mimic inhibited the proliferation and promoted the apoptosis of MDA-MB-231, while silencing the expression of miR-199a-3p induced by miR-199a-3p in-hibitor increased the proliferation and suppressed the apoptosis of MDA-MB-231.Conclusion:The expression of miR-199a-3p is lower in breast cancer, which shows its tumor suppression effect by regulating the proliferation and apoptosis of breast cancer cells.

Objective To compare the dose distribution of mantle-field radiotherapy using conven-tional radiotherapy(CRT) and four intensity-modulated radiotherapy(IMRT) techniques in stage Ⅰ and Ⅱ Hodgkin's lymphoma(HL). Methods Ten patients with patholocally proved early stage HL underwent CT simulation. Then both CRT and IMRT planning performed using ECLIPS treatment planning system(TPS). The dosimetric parameters of different irradiation plans were analyzed, including conformal index (CI), homo-geneity index (HI), D95 and V95 of planning target volume (PTV), Dmax,Dmean,Dmin,V5,V10,V20 and V30 of the lung, as well as Dmax of the spinal cord. Results The isodose distribution and homogeneity of PTV were better in IMRT plans when compared with CRT plans. Target coverage, target dose conformity and homogene-ity were similar among all the four IMRT techniques. The V30 of the lung using IMRT was lower than using CRT,but the low-dose volume of the lung was higher. Among the four IMRT technique plans,the lung V20 and V30 were lower in plans with more-field technique,but the V5 and V10 were higher. The Dmax of the spinal cord using IMRT was all lower than that using CRT. Conclusions IMRT is better than CRT in target cov-erage, conformity, homogeneity and normal tissue sparing, especially in protecting the spinal cord and decrea-sing high-dose lung volume,though the low-dose lung volume is higher. Seven-field IMRT technique for man-de-field radiotherapy is recommanded.

OBJECTIVETo detect the infection of human papillomavirus (HPV) 6/11, 16/18, 31/33 in patients with head and neck squamous cell carcinoma and explore the relationship between HPV infection and expression of p16 and EGFR in the tumor tissue and their clinical significance.

METHODSThe infection of HPV6/11, 16/18, 31/33 was detected by in situ hybridization (ISH), and expression of p16 and EGFR was assessed by immunohistochemistry in biopsy or surgical specimens of 43 cases of head and neck squamous cell carcinoma, and analyzed its impact on the prognosis. Spearman rank correlation method was used for analysis of the relationship. Overall survival rate of the patients was estimated by Kaplan-Meier analysis. Cox regression model was used for multivariate analysis.

RESULTSHPV6/11, 16/18, 31/33 were detected in 25.6% (11/43) of this group of patients, among them, HPV16/18 accounted for 63.6%, HPV31/33 accounted for 27.3%, and HPV6/11 accounted for 0. EGFR was expressed in 69.8% and p16 was expressed in 53.5% of the patients. The difference was statistically significant between the HPV-positive and HPV-negative groups in ethnicity, smoking, alcohol consumption (P = 0.045, 0.040, 0.011, respectively). HPV infection was found to be positively correlated with p16 expression and inversely correlated with EGFR expression (P = 0.029, P = 0.009). The expression of p16 protein was negatively correlated with EGFR protein expression (r = -0.447, P = 0.003). The 3-year overall survival rate was 60.0% in the HPV-positive group and 59.7% in the negative group (P = 0.789); 72.2% in the p16-positive patients and 43.9% in the p16-negative patients (P = 0.012); 48.8% in the EGFR-positive patients and 81.8% in the EGFR-negative patients (P = 0.037).

CONCLUSIONSThe results of our study suggest that the HPV infection rate, HPV subtypes and clinicopathological features of HPV-positive SCCHN are in accordance with those reported in Western literatures. There may be differences between the HPV infections in Uygur and Han nationalities. HPV infection is positively correlated with p16 and negatively correlated with EGFR expressions. The prognosis of p16-positive patients is significantly better than that of negative cases, and p16 is an independent prognostic factor for head and neck squamous cell carcinoma.

Carcinoma, Squamous Cell ; mortality ; virology ; Cyclin-Dependent Kinase Inhibitor p16 ; metabolism ; Head and Neck Neoplasms ; mortality ; virology ; Human papillomavirus 16 ; Humans ; Papillomavirus Infections ; metabolism ; Prognosis ; Receptor, Epidermal Growth Factor ; metabolism ; Survival Analysis