Downregulation of MUC1 Inhibits Proliferation and Promotes Apoptosis by Inactivating NF-κB Signaling Pathway in Human Nasopharyngeal Carcinoma

Objective To investigate the effect of mucin 1(MUC1)on the proliferation and apoptosis of nasopharyngeal carcinoma(NPC)and its regulatory mechanism.Methods The 60 NPC and paired para-cancer normal tissues were collected from October 2020 to July 2021 in Quanzhou First Hospital.The expression of MUC1 was measured by real-time quantitative PCR(qPCR)in the patients with PNC.The 5-8F and HNE1 cells were transfected with siRNA control(si-control)or siRNA targeting MUC1(si-MUC1).Cell proliferation was analyzed by cell counting kit-8 and colony formation assay,and apoptosis was analyzed by flow cytometry analysis in the 5-8F and HNE1 cells.The qPCR and ELISA were executed to analyze the levels of TNF-αand IL-6.Western blot was performed to measure the expression of MUC1,NFкB and apoptosis-related proteins(Bax and Bcl-2).Results The expression of MUC1 was up-regulated in the NPC tissues,and NPC patients with the high MUC1 expression were inclined to EBV infection,growth and metastasis of NPC.Loss of MUC1 restrained malignant features,including the proliferation and apoptosis,downregulated the expression of p-IкB、p-P65 and Bcl-2 and upregulated the expression of Bax in the NPC cells.Conclusion Downregulation of MUC1 restrained biological characteristics of malignancy,including cell proliferation and apoptosis,by inactivating NF-κB signaling pathway in NPC.

Signal intensity changes of dentate nucleus on plain MR T1WI innasopharyngeal carcinoma patients after radiotherapy andmultiple injections of gadolinium-base contrast agent

Objective To observe changes of plain MR T1WI signal intensity of dentate nucleus in nasopharyngeal carcinoma patients after radiotherapy and multiple times of intravenous injection of gadolinium-based contrast agent(GBCA).Methods Fifty patients with pathologically confirmed nasopharyngeal carcinoma and received intensity-modulated radiotherapy were retrospectively enrolled as the nasopharyngeal carcinoma group,and 50 patients with other malignant tumors and without history of brain radiotherapy were retrospectively enrolled as the control group.All patients received yearly GBCA enhanced MR examinations for the nasopharynx or the head.T1WI signal intensities of the dentate nucleus and the pons on same plane were measured based on images in the year of confirmed diagnosis(recorded as the first year)and in the second to the fifth years.T1WI signal intensity ratio of year i(ranging from 1 to 5)was calculated with values of dentate nucleus divided by values of the pons(ΔSI i),while the percentage of relative changes of year j(ranging from 2 to 5)was calculated withΔSI j compared toΔSI 1(Rchange j).The values of these two parameters were compared,and the correlation ofΔSI and GBCA injection year-time was evaluated within each group.Results No significant difference of gender,age norΔSI 1 was found between groups(all P>0.05).The second to the fifth yearΔSI and Rchange in nasopharyngeal carcinoma group were all higher than those in control group(all P<0.05).Within both groups,ΔSI was positively correlated with GBCA injection year-time(both P<0.05).Conclusion Patients with nasopharyngeal carcinoma who underwent radiotherapy and multiple times of intravenous injection of GBCA tended to be found with gradually worsening GBCA deposition in dentate nucleus,for which radiotherapy might be a risk factor.

Isotropic volumetric MRI for displaying cranial perineural spread of cranial nerve in nasopharyngeal carcinoma

Objective To observe the value of isotropic volumetric MRI for displaying perineural spread(PNS)of cranial nerve(CN)in nasopharyngeal carcinoma.Methods Eighty-seven patients with pathologically proven nasopharyngeal carcinoma were prospectively enrolled.MR scanning,including three-dimensional liver acquisition with volume acceleration-flexible(3D LAVA_Flex)image,T2WI with fat suppression(T2WI-FS),T1WI,contrast enhancement(CE)T1WI-FS of nasopharynx and neck region were performed.The displaying rates of CN PNS were evaluated and compared between 3D LAVA_Flex and T2WI-FS,T1WI,CE-T1WI-FS at patient level,CN group level and neural level,respectively.Results The displaying rate of CN PNS in all 87 nasopharyngeal carcinoma patients by 3D LAVA_Flex sequence was 49.43%(43/87),higher than that of conventional MRI(30/87,34.48%,P=0.001).Among 59 patients with advanced nasopharyngeal carcinoma diagnosed with conventional sequences,the displaying rate of CN PNS was 71.19%(42/59)by 3D LAVA-Flex sequence,higher than that of conventional MRI(30/59,50.85%,P=0.001).At both patient level and posterior CN level,significant differences of the displaying rate of CN PNS were found between 3D LAVA-Flex sequence and T2WI-FS,T1WI,CE-T1WI-FS,while at CN level,the displaying rates of mandibular nerve PNS,CNⅨ—ⅪPNS in jugular foramen(P<0.05)and CNⅨ—ⅫPNS in carotid space of 3D LAVA_Flex sequence were all significantly higher than that of T2WI-FS,T1WI and CE-T1WI-FS(all P<0.05),of PNS of CNⅢ—Ⅴin cavernous sinus were higher than that of T2WI-FS(P<0.05),while of PNS of hypoglossal nerve were significantly higher than that of T2WI-FS and T1WI(both P<0.05).Conclusion 3D LAVA_Flex sequence could be used to effectively display CN PNS of nasopharyngeal carcinoma.

3-Methyladenine potentiates paclitaxel-induced apoptosis and phosphorylation of cyclin-dependent kinase 1 at thr161 in nasopharyngeal carcinoma cell

Background:Nasopharyngeal carcinoma(NPC)exhibits a significant prevalence in the southern regions of China,and paclitaxel(PTX)is frequently employed as a medication for managing advanced NPC.However,drug resistance is typically accompanied by a poor prognosis.Exploring the synergistic potential of combining multiple chemotherapeutic agents may represent a promising avenue for optimizing treatment efficacy.Methods:This study investigated whether 3-Methyladenine(3-MA)could potentiated the effect of PTX and its potential molecular mechanism.Samples were divided into the following categories:Negative control(NC)with the solvent dimethyl sulfoxide(DMSO,0.5%v/v),PTX(400 nM),3-MA(4 mM),and PTX(400 nM)+3-MA(4 mM).The viability of NPC cells was assessed using both the cell counting kit-8(CCK-8)assay and the colony formation assay.Microscopic observation was performed to identify morphological cell changes.Flow cytometry was used to assess cell cycle status,mitochondrial membrane potential(MMP),and apoptotic cells.Western blotting was conducted to quantify the protein expression.Results:3-MA enhanced PTX-specific inhibition of NPC cell proliferation.PTX,either alone or in combination with 3-MA,caused cell cycle halt at the G2/M phase in the majority of NPC cells,and the combination treatment of PTX with 3-MA induced a higher rate of NPC cell death compared to PTX alone.Western blotting results revealed the combination of PTX with 3-MA heightened activation of cyclin-dependent kinase 1(CDK1),a key molecule in shifting cells from mitotic arrest to apoptosis,led to a reduction in Myeloid Cell Leukemia 1(MCL-1)expression and an increase in Poly(ADP-ribose)polymerase(PARP)cleavage.Conclusion:The concurrent administration of PTX with 3-MA effectively enhances PTX’s inhibitory impact on NPC and activates the apoptosis signal regulated by CDK1.

Screening for nasopharyngeal carcinoma in high-incidence regions——Next steps

Epstein-Barr virus(EBV)infection is a well-established risk factor in the development of nonkeratinizing and undifferentiated forms of nasopharyngeal carcinoma(NPC)common in parts of China and Southeast Asia.Early detection of NPC can significantly improve survival rates,as the 5-year survival rate for patients diagnosed at an early stage can exceed 90%after treatment.Studies have demonstrated that screening for NPC using EBV markers is an effective tool for identifying individuals with the disease.Future efforts should focus on implementing screening programs in high-incidence populations,assessing and refining screening algorithms,and exploring new,potentially more cost-effective screening methods.It is crucial to ensure that any new approaches are validated as superior or non-inferior to existing protocol before being adopted on a wider scale.The success of these screening tools in reducing NPC-related morbidity and mortality will depend on their effective implementation and ensuring access for the populations most in need of preventive interventions.This opinion piece briefly summarizes the current evidence supporting EBV-based screening for NPC detection and discusses future steps,including:1)the implementation of effective NPC screening programs,2)the evaluation of improvements in screening methodologies,and 3)the consideration of novel approaches to screening.

Re-searching nasopharyngeal carcinoma

Nasopharyngeal carcinoma(NPC)has been a focus of medical research for more than 100 years,with significant interest emerging over the last 58 years following the identification of the link between the disease and Epstein-Barr virus(EBV)infection.NPC possesses several distinctive characteristics among human cancers,notably its well-documented global epidemiology,which reveals localized high-incidence regions primarily in Southeast Asia,particularly in the Southern provinces of China near the Pearl river,as well as in Greenland and North Africa.Epidemiological data indicate a marked male predominance,early disease onset,and a nearly 100%prevalence of latent EBV infection in the tumors.Due to lack of consistent pattern of cancer-related mutations in NPC genomes and excessive DNA-methylation in the tumor cells,NPC can be considered"an epigenetic cancer".Despite extensive researches,convincing biological explanations for these unique characteristics remain elusive.Recently,suggestive evidence has been published that specific local variants of EBV may represent major high risk factors.In spite of tumor and virus specific immunity,it has not been possible to use this for improved treatment.Ongoing studies on the role of the local microflora and tumor microenvironment are essential for a comprehensive understanding of host-EBV-tumor interactions.Ultimately,this knowledge aims to enhance diagnosis,disease fractionation,treatment strategies,and potentially prevention of NPC.

Treatment of nasopharyngeal carcinoma and prevention of nonalcoholic Wernicke’s disease:A case report and review of literature

BACKGROUND Wernicke encephalopathy is a neurological disorder caused by thiamine deficiency,commonly seen in alcoholic populations but also involving other circumstances that may lead to thiamine deficiency.The recognition of Wernicke encephalopathy often depends on clinicians’keen ability to detect its typical triad of features;however,most cases do not present with the full constellation of signs,which complicates the timely identification of Wernicke encephalopathy.CASE SUMMARY This case report describes a patient with nasopharyngeal carcinoma who developed abnormal ocular function and ataxia following concurrent chemoradiotherapy,without a history of alcohol abuse.With the aid of radiological examinations,he received a timely diagnosis and treatment;however,his symptoms did not fully resolve during follow-up.CONCLUSION For patients with malignant tumors exhibiting neurological symptoms,clinicians should consider the possibility of Wernicke encephalopathy and provide prophylactic thiamine therapy.

The role of glycoproteins in nasopharyngeal carcinoma pathogenesis

Nasopharyngeal carcinoma(NPC)is a malignant tumor arising from the nasopharyngeal epithelium.It consists of undifferentiated squamous cells in the nasopharynx.This type of epithelial cell neoplasm is globally distributed,with the highest prevalence observed in certain regions of the world.It has been known since ancient times.The incidence of NPC is steadily decreasing as data on the molecular factors involved in the pathogenesis of NPC accumulate.Glycoproteins are characterized by polymers of saccharides attached to the amino acid sequences of proteins during the process of glycosylation.They are present in all animal cells and are especially abundant on the surface of tumor cells.Alterations in expression of cellular glycoproteins have recently attracted attention as a key component of neoplastic progression.Tumor-associated glycoproteins may serve as a hallmark of cancer cells and thus represent novel diagnostic and even therapeutic targets.Interest in the role of glycoproteins in cancer in general and specifically in NPC pathology has steadily increased over the past fifty years,reaching over thousands and two hundred publications in the last five years,respectively.Here,data on a specific class of proteins,glycoproteins,involved in tumorigenesis of NPCs are summarized,with a focus on a few of the best-studied ones.Relevant studies performed mainly in the last five years were retrieved and collected through the PubMed system.

Predicting distant metastasis in nasopharyngeal carcinoma using gradient boosting tree model based on detailed magnetic resonance imaging reports

BACKGROUND Development of distant metastasis(DM)is a major concern during treatment of nasopharyngeal carcinoma(NPC).However,studies have demonstrated im-proved distant control and survival in patients with advanced NPC with the addition of chemotherapy to concomitant chemoradiotherapy.Therefore,precise prediction of metastasis in patients with NPC is crucial.AIM To develop a predictive model for metastasis in NPC using detailed magnetic resonance imaging(MRI)reports.METHODS This retrospective study included 792 patients with non-distant metastatic NPC.A total of 469 imaging variables were obtained from detailed MRI reports.Data were stratified and randomly split into training(50%)and testing sets.Gradient boosting tree(GBT)models were built and used to select variables for predicting DM.A full model comprising all variables and a reduced model with the top-five variables were built.Model performance was assessed by area under the curve(AUC).RESULTS Among the 792 patients,94 developed DM during follow-up.The number of metastatic cervical nodes(30.9%),tumor invasion in the posterior half of the nasal cavity(9.7%),two sides of the pharyngeal recess(6.2%),tubal torus(3.3%),and single side of the parapharyngeal space(2.7%)were the top-five contributors for predicting DM,based on their relative importance in GBT models.The testing AUC of the full model was 0.75(95%confidence interval[CI]:0.69-0.82).The testing AUC of the reduced model was 0.75(95%CI:0.68-0.82).For the whole dataset,the full(AUC=0.76,95%CI:0.72-0.82)and reduced models(AUC=0.76,95%CI:0.71-0.81)outperformed the tumor node-staging system(AUC=0.67,95%CI:0.61-0.73).CONCLUSION The GBT model outperformed the tumor node-staging system in predicting metastasis in NPC.The number of metastatic cervical nodes was identified as the principal contributing variable.

Changing Nasopharyngeal Carcinoma Survival in Southern China during 2000-2015: Results of a Retrospective Cohort Study

Objective: Around 50% of new nasopharyngeal carcinoma (NPC) cases come from China. The present study aimed to update the surveillance of NPC survival in southern China, and investigate the survival disparities between sexes within this patient population. Methods: Patients diagnosed with primary and invasive NPC between 2000 and 2015 were included in this study. Data on demographics, diagnosis, and follow-up to December 2020 were collected. Patients were stratified by diagnosis period, sex, and age at diagnosis. Survival analysis employed cohort and Life Table methods, Kaplan-Meier curves, log-rank tests, and Cox regression. Results: The study included 32,901 patients, of whom 69.6% were males. The overall 5-year survival rate rose from 69.6% in 2000-2003 to 83.3% in 2013-2015, with a consistent average increase of 3.3% every 3 years. For males, the 5-year survival rate increased from 66.3% to 82.0%, faster than females. Kaplan-Meier curves demonstrated a significantly higher survival rate for females than males, and subgroup analysis confirmed this advantage. The Cox proportional hazards model confirmed the lower mortality risk for females (HR 0.75, 95% CI: 0.71 - 0.78), patients with younger ages at diagnosis, and patients diagnosed in more recent years (All P Conclusions: The 5-year survival rate for NPC patients in southern China has significantly and steadily improved from 2000 to 2015, indicating the improved quality of cancer care in China. The survival advantage of female patients is not limited to younger patients but is also observed in postmenopausal patients, despite the gradual narrowing of the gender gap.

Clinical Analysis of Xerostomia in Patients with Nasopharyngeal Carcinoma after Radiation Therapy

Objective: To investigate the severity of xerostomia and its impact on the quality of life in patients with nasopharyngeal carcinoma after conventional radiation therapy. Methods: One hundred and thirty-six patients with nasopharyngeal carcinoma, treated by conventional radiation therapy in Cancer Center, Sun Yat-sen University, were surveyed by interview at the outpatient department. A questionnaire and a visual analog scale (VAS) were used to analyze xerostomia and xerostomia-related problems. Results: Of 136 patints, 73.5% experienced a moderate to severe degree of xerostomia; 82.4% had to sip water to facilitate speech; 92.6% had to sip water to facilitate chewing and swallowing; 91.2% changed their feeding pattern (eating only mashed food); 61.3% had to wake up to drink water because of dry mouth; 75.0% had dental lesions to varying degrees. Conclusion: 73.5% of the patients with nasopharyngeal carcinoma after conventional radiation therapy experienced a moderate to severe degree of xerostomia. Xerostomia has a significant impact on the patient's speech, deglutition, and sleep, and can increase the morbidity of the dental diseases.

Significance of the Expression of CyclinD1 and Ki67 Antigen in Nasopharyngeal Carcinoma

Objective: To detect the expression of cyclinD1 and Ki67 in nasopharyngeal carcinoma (NPC) and their correlation with the biological behaviors and prognosis. Methods: 56 cases of biopsy specimens of NPC which had been embedded with para?n in 1996 in our hospital were collected and immunostained with cyclinD1 and Ki67 monoclonal antibodies by means of the streptavidin peroxides method. The patients were followed up periodically, and then their biological behaviors and prognosis were statistically analyzed. Results: The percentage of cyclinD1 and Ki67 positive cells in the NPC specimens ranged from 0–54% and 0–31% respectively. The staining was nuclear. Of the 56 cases, 30 cases (56.6%) highly expressed cyclinD1 or Ki67 HPI and 26 cases (46.4%) lowly expressed cyclinD1, while only 16 cases (28.6%) showed Ki67 HPI (high proliferated index) and 40 cases (71.4%) showed Ki67 LPI (low proliferated index). Patients who lowly expressed cyclinD1 or highly expressed Ki67 had a higher radiosensitivity and a better prognosis. Conclusion: CyclinD1 and Ki67 immunohistochemical staining is considered to be useful, not only as an independent factor of radiosensitivity and prognosis respectively, but also as a means of determining the optimum treatment for each individual patient with NPC.

A Prospective Study on Therapeutic Gain by Concurrent Chemoradiotherapy for Stage Ⅱ-Ⅳa Nasopharyngeal Carcinoma

The benefit achieved by concurrent chemoradiotherapy（CCR） and sequential chemoradiotherapy（SCR） vs radiotherapy（RT） alone for patients with stage Ⅱ-Ⅳa nasopharyngeal carcinoma（NPC） was compared.A total of 113 patients with stage Ⅱ-Ⅳa NPC were allotted into CCR group（n=38）,SCR group（n=36） and RT alone group（n=39）.All patients were irradiated with the same RT technique to ≥66 Gy at 2 Gy per fraction,conventional 5 fractions/week in all groups.The CCR group received concurrent chemotherapy of weekly cisplatin for 7 weeks,and the SCR group received neoadjuvant and（or） adjuvant chemotherapy.The results showed that the 3-and 5-year overall survival rate was significantly higher in CCR group than in RT alone group（92.16% vs 61.54%,81.58% vs 51.28%,P〈0.005）.The median survival time was significantly longer in CCR group than in RT alone group（67.8 months vs 52.7 months,P〈0.005）.It was concluded that CCR could significantly improve overall survival rate,progression-free survival rate,and median survival time when compared with RT alone.

Expression of Cyclooxygenase-2 in Nasopharyngeal Carcinoma and Its Relation to Angiogenesis and Prognosis

Objective： The purpose of this study was to evaluate cyclooxygenase-2 （COX-2） expression in nasopharyngeal carcinoma （NPC） and its correlation with clinicopathologic features, angiogenesis, and prognosis. Methods： The expressions of COX-2 and vascular endothelial growth factor （VEGF） and microvascular density （MVD） were determined with immunohistochemical methods in eighty-six NPC patients followed up over 5 years. Results： Sixty-three tumors （73.3%） were classified as COX-2 positive. COX-2 expression was positively related to VEGF expression （r=0.438, P〈0.01） and correlated with the tumor pathological grade, extent of primary lesion, lymph node metastasis, distant metastasis and shorter survival. Conclusion： Our results suggest that COX-2, being highly expressed and strongly correlated with angiogenesis in nasopharyngeal carcinoma, is apt to be used as a predictor of prognosis, including local recurrence and distant metastasis.

Application of Support Vector Machine to Predict 5-year Survival Status of Patients with Nasopharyngeal Carcinoma after Treatment

Objective： Support Vector Machine （SVM） is a machine-learning method, based on the principle of structural risk minimization, which performs well when applied to data outside the training set. In this paper, SVM was applied to predict 5-year survival status of patients with nasopharyngeal carcinoma （NPC） after treatment, we expect to find a new way for prognosis studies in cancer so as to assist right clinical decision for individual patient. Methods： Two modelling methods were used in the study; SVM network and a standard parametric logistic regression were used to model 5-year survival status. And the two methods were compared on a prospective set of patients not used in model construction via receiver operating characteristic （ROC） curve analysis. Results： The SVM1, trained with the 25 original input variables without screening, yielded a ROC area of 0.868, at sensitivity to mortality of 79.2% and the specificity of 94.5%. Similarly, the SVM2, trained with 9 input variables which were obtained by optimal input variable selection from the 25 original variables by logistic regression screening, yielded a ROC area of 0.874, at a sensitivity to mortality of 79.2% and the specificity of 95.6%, while the logistic regression yielded a ROC area of 0.751 at a sensitivity to mortality of 66.7% and gave a specificity of 83.5%. Conclusion： SVM found a strong pattern in the database predictive of 5-year survival status. The logistic regression produces somewhat similar, but better, results. These results show that the SVM models have the potential to predict individual patient＇s 5-year survival status after treatment, and to assist the clinicians for making a good clinical decision.

Application of Superselective Artery Embolization in Nasopharyngeal Angiofibroma before Operation

Objective： To evaluate the clinical application of superselective transcatheter arterial embolization （TAE） in nasopharyngeal angiofibroma before operation. Methods： Superselective angiography was done via femoral. TAE with polyvinyl alcohol particles and/or gelfoam （GF） was performed in 12 patients with nasopharyngeal angiofibroma. All patients underwent surgical removal of devascularized tumors in 3 to 7 days after TAE. Results： During digital subtraction angiography, tumor staining was seen in 12 patients. Embolization of maxillary artery was performed in 12 cases and additional embolization of ascending pharyngeal artery in 8 cases. Conclusion： Superselective angiographic diagnosis, embolization and appropriate embolic particle size are important for successful treatment of nasopharyngeal angiofibroma. TAE is safe and effective in decreasing haemorrhage during surgical operation for nasopharyngeal angiofibroma.

Glutathione S-transferase M1 and T1 Gene Deletion Associated with Increased Susceptibility to Nasopharyngeal Carcinoma

Objective： To evaluate the association of Glutathione S-transferase （GST） M1 and T1 genetic polymorphisms and susceptibility to nasopharyngeal carcinoma （NPC） in a high risk area of Guangxi Zhuang Autonomous Region （province）, Southwest of China. Methods： A case-control study was conducted to investigate the genetic polymorphisms of these enzymes （GSTM1 and GSTT1 null genotypes）. A total of 127 NPC cases and 207 controls were recruited. Results： GSTM1 and GSTT1 null genotype frequencies were higher among NPC patients at a level of statistical significance （P〈0.005; P〈0.001 respectively）, and both GSTM1 and GSTT1 null genotype were even more significant （P〈0.001）. Conclusion： NPC is the most common cancer in Guangxi. GST enzymes are involved in the detoxification of many environmental carcinogens. Homozygous deletions of GSTM1 and GSTT1 have been associated with several types of cancer. The risk to develop NPC has been associated with environmental factors such as cigarette smoking and EB virus infection. The present results indicate that the GSTM1 and GSTT1 deletion polymorphisms are associated with an increase risk of susceptibility to NPC, and both detoxific enzyme genes deletion is more important than a single gene deletion for the susceptibility to NPC.

Clinical Effect of Biafine in Preventing and Treating Radioactive Skin Destruction of Nasopharyngeal Carcinoma Patients Caused by Concurrent Intensity- Modulated Radiotherapy and Chemotherapy

OBJECTIVE To observe the clinical effect of Biafine cream in preventing and treating radioactive skin destruction of nasopharyngeal carcinoma （NPC） patients induced by synchronized intensity-modulated radiotherapy and chemotherapy. METHODS The patients were treated with Varian-600CD 6 MV X-ray three-dimensional （3D） conformal intensity-modulation radiotherapy （IMRT）, with a 120-blade multiple leaf-blade grating and in combination with synchronal Capecitabine chemotherapy. Fifty-one patients undergoing radiotherapy and chemotherapy were randomized into 2 groups： 25 in the treatment group received a Biafine cream application following the first radiotherapy and / or chemotherapy, while the other 26, served as controls. They received no application of the cream, but only followed normal procedures for conventional radiotherapy and health education. RESULTS The rate of the skin-reaction was 100% in the patients of both groups. A mild radiation reaction （grade-Ⅰ and Ⅱ） occurred as follows： 88.0% （22/25 cases） in the treatment group and 57.7% （15/26 cases） in the control group. A grade-Ⅲ radiation reaction developed in 12.0% （3/25 cases） in the treatment group, and 42.3% （11/26 cases） in the controls. There was a significant difference, P〈0.01 between the two groups. Concerning the degree of the skin response before the patients received a dose of 40 Gy, the radiation reaction emerged in 32.0% （8/25） of the cases in the treatment group, and in 96.2% （25/26） of the cases of the control group. CONCLUSION Biafine cream can effectively reduce the acute irradiation or chemotherapy-induced dermal injury. It can alleviate the patients＇ suffering, improve their quality of life, and can ensure less injurious radiotherapy.

Magnetic Resonance Imaging Findings of Temporal Lobe Radiation Encephalopathy in Nasopharyngeal Carcinoma

Objective： To observe the magnetic resonance imaging （MRI） morphological features of radiation encephalopathy （REP） in nasopharyngeal carcinoma （NPC） and investigate their diagnostic value. Methods： The MRI data of 160 lesions from 104 NPC patients with the diagnosis of temporal lobe REP were retrospectively analyzed. The MRI was performed after radiation therapy of NPC with an interval ranged from 8 months to 13 years. The imaging sequences included T1-weighted imaging and T2-weighted imaging. Additionally T1-weighted imaging with injection of the contrast agent of Gd-DTPA was performed in 111 lesions and fluid attenuated inversion recovery （FLAIR） was performed on 37 lesions, and among them, 2 cases were subjected to MR perfusion weighted imaging （PWI）. Results： Unilateral temporal lobe was involved in 48 cases of REP, bilateral temporal lobe in 56 cases of REP respectively, with a total of 160 lesions. The REP in the white matter displayed hyper-intensity signal on T2-weighted imaging which could be homogenous, whereas areas with heterogeneous hypo-intensity signal could be seen in 59 of them otherwise with hyper-intensity signal, and 91 lesions of white matter were associated with gray matter lesions with an appearance of hypo-intensity signal on T1-weighted imaging and hyper-intensity signal on T2-weighted imaging. In 111 lesions with the Gd-DTPA enhanced T1-weigthed imaging, 91 showed the enhancement of brain parenchyma. Hemorrhage and hemosiderosis occurred in 5 lesions of REP. Conclusion： REP in NPC has a multiplicity of the imaging features on MRI, in addition to the common involvement of white matter, including other relatively frequent findings, such as the involvement of gray matter, hemorrhage, hemosiderosis and blood-brain barrier destruction, those could be clearly revealed on MRI.

Expression of DNA-dependent protein kinase in the nasopharyngeal tissue during carcinogenesis

Objective： To observe the expression of DNA-dependent protein kinase （DNA-PKcs） in the nasopharyngeal tissues during carcinogenesis. Methods： Patients including 30 cases of nasopharyngitis, 42 cases of nasopharyngeal atypical hyperplasia and 34 cases of nasopharyngeal carcinoma （NPC） were chosen from Zhongshan area in which there is high incidence rate of NPC. The expression of DNA-PKcs in the nasopharyngeal tissue was examined by immunohistochemistry. Results： The expression rates of DNA-PKcs in the nasopharyngitis tissue, the nasopharyngeal precancerous lesion and the NPC were 6.7%, 64.3% and 55.9%, respectively （P〈 0.001）. Conclusion： The expression of DNA-dependent protein kinase may play an important role in nasopharyngeal tissue carcinogenesis.