[Daratumumab for the treatment of primary systemic amyloidosis: a multicenter retrospective analysis].

Objective: To analyze the efficacy and safety of Daratumumab for the treatment of primary AL light chain systemic amyloidosis. Methods: Twenty one patients who were diagnosed as primary AL light chain systemic amyloidosis and treated with Daratumumab from 7 centers were retrospectively analyzed. Daratumumab was administrated as first line therapy in seven patients and 14 patients with relapsed settings. Hematological response, safety and survival were analyzed. Results: All 7 patients achieved very good partial response (VGPR) or better with first-line application of daratumumab. Three patients died, and the other four achieved organ remission. Among 14 relapsed patients, 2 patients had a difference of free light chain (dFLC) less than 20 mg/L before treatment, and 9 with a dFLC of more than 50 mg/L. All patients reached partial response (PR) or better, including 4 patients with complete response (CR), 3 with VGPR and 2 with PR. The response rate was 100% in 3 patients with dFLC 20-50 mg/L at baseline. The organ remission rate was 50% in patients with heart involvement and 58.3% in patients with kidney impairment. The overall median follow-up period was 5.3 months, and 11 months in surviving patients. One patient died of severe infection and disseminated intravascular coagulation (DIC) with stable amyloidosis. One patient switched to other regimens because dFLC elevated but did not fulfill progressive disease after 2 year application. As to safety, no grade 3/4 infusion reaction developed, and grade 1 infusion reaction occurred in 3 cases during the first infusion. Lymphocytopenia was seen in 75% patients including grade 3 or more in 30% patients. Conclusion: Daratumumab is effective to eliminate serum free light chain in both newly diagnosed and relapsed patients with systemic amyloidosis.

Application of Virtual Anatomy Technology in Postmortem Examination of Medical Dispute Cases.

ABSTRACT: Objective To discuss the application value of CT scanning technology in cause of death determination of medical dispute cases. Methods From July 2017 to December 2018, postmortem CT imaging data of 12 medical dispute cases were collected. CT imaging diagnosis results and anatomy findings as well as differences between antemortem and postmortem CT diagnosis were compared. The advantages and disadvantages of CT routine tests of the cadavers in terms of the diagnosis of disease and damage were analyzed. Results The comparison between CT imaging diagnosis and anatomical findings showed that CT scans had advantages in the diagnosis of disease and damage with large differences in density changes, such as atelectasis, pneumonia, calcification, fracture and hemorrhage, etc. The comparison of CT diagnosis in antemortem and postmortem examination showed that the cadavers of medical dispute cases were well preserved and that postmortem CT scan was meaningful for the diagnosis of antemortem diseases. Conclusion Virtual anatomy technology has a relatively high application value in postmortem examination of medical dispute cases. It can provide effective information for the appraisers before the autopsy and can also provide a reference for cause of death analysis when the anatomy cannot be performed.

[Clinical analysis of rituximab-induced interstitial lung disease].

Objective: To investigate the clinical characteristics, diagnosis-treatment points and prognosis of rituximab-induced interstitial lung disease (R-ILD), and to improve the recognition of this disease. Methods: The clinical data on 4 cases of R-ILD were analyzed retrospectively, and the related literatures were reviewed. The literature review was carried out respectively in Wanfang Data, CNKI and PubMed by October 2016 with"rituximab"and"interstitial lung disease"or"interstitial pneumonitis"as the search terms. Results: The all 4 patients received chemotherapy including rituximab, had respiratory symptoms after 2 to 5 cycles chemotherapy respectively. The chest computerized tomography findings of all 4 cases showed diffuse ground glass opacities. In all of the patients, the diagnosis of R-ILD was made and glucocorticoids therapy was initiated. After treatment, the clinical symptoms improved promptly and follow-up chest computerized tomography showed pulmonary lesions significantly resolved. Literature review found 48 articles (2 reviews, 6 original articles, 39 case reports and 1 other article) . 50 cases of R-ILD were collected and the chief complaint were dyspnea, cough and fever. The ground-glass pattern on the CT scan of the chest was the important feature of this disease. Therapy included glucocorticoids, discontinuation of rituximab, and any other clinically necessary measures. Conclusions: Rituximab can cause interstitial lung disease. The diagnosis relies on clinical manifestation and radiological findings. The good prognosis depends on prompt discontinuation of rituximab and treatment with glucocorticoids.

Influence of interleukin-1ß and interleukin-6 gene polymorphisms on the development of acute pancreatitis.

We investigated the association between 3 main proinflammatory cytokines [interleukin (IL)-1ß and IL-6] and the risk of acute pancreatitis. Polymerase chain reaction-restriction fragment length polymorphism was used to genotype IL-1ß+3954 C/T (rs1143634) and IL-1ß-511 C/T (rs16944) and IL-6 -174 G/C (rs1800795) and IL-6 -634 C/G (rs1800796). The genotype distributions of IL-1ß+3954 C/T (rs1143634) and IL-1ß-511 C/T (rs16944) and IL-6 -174 G/C (rs1800795) and IL-6 -634 C/G (rs1800796) were in Hardy-Weinberg equilibrium for the control group. Multivariate regression analyses showed that subjects carrying the rs1143634 TT genotype had a significantly increased risk of acute pancreatitis, with an adjusted odds ratio (95% confidence interval) of 2.11 (1.03-4.51). Subjects carrying the IL-1ß rs1143634 TT genotype had a significantly increased risk of acute pancreatitis in our Chinese population.

Long non-coding RNA BCAR4 accelerates cell proliferation and suppresses cell apoptosis in gastric cancer via regulating MAPK/ERK signaling.

OBJECTIVE: As the fourth most common malignant tumor with high mortality rate, gastric cancer (GC) seriously threatens people's health and life quality worldwide. The aim of this study was to explore the functional role of long non-coding RNA (lncRNA) BCAR4 in GC. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay was used to detect the expression level of lncRNA BCAR4 in GC cell lines and tissues. Subsequently, cell counting kit-8 (CCK-8) assay, colony formation assay, and flow cytometry were recruited to investigate the role of lncRNA BCAR4 in the proliferation and apoptosis of GC cells, respectively. Western blotting was used to detect the protein expression level of mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinase (ERK) in GC. Besides, tumor formation assay was applied to examine the ability of lncRNA BCAR4 in vivo. RESULTS: LncRNA BCAR4 was highly expressed in both GC tissues and cell lines. CCK-8 assay, colony formation assay, and flow cytometry results indicated that up-regulated lncRNA BCAR4 significantly promoted cell proliferation and suppressed cell apoptosis in GC. Besides, over-expression of lncRNA BCAR4 could activate the MAPK/ERK signaling pathways. Tumor xenograft formation assay demonstrated that over-expression of lncRNA BCAR4 promoted tumor formation in vivo. CONCLUSIONS: LncRNA BCAR4 was proved significantly up-regulated in GC. Over-expression of lncRNA BCAR4 promoted cell proliferation and suppressed cell apoptosis in vitro and promoted tumor formation in vivo. Besides, Western blotting revealed that lncRNA BCAR4 played an oncogenic role in GC via regulating MAPK/ERK signaling.

Characteristics and prognostic significance of circRNA-100876 in patients with colorectal cancer.

OBJECTIVE: The purpose of this study was to explore the correlation between circRNA-100876 and the clinicopathological parameters of patients with colorectal cancer (Cc). PATIENTS AND METHODS: Quantitative real-time polymerase chain reaction (RT-qPCR) was applied to detect the circRNA-100876 expression in Cc tissues and cell lines. Overall survival analysis was carried out to explore the correlation between circRNA-100876 and the prognosis of Cc patients by Kaplan-Meier method and Log-rank method. Subsequently, Chi-square test was used to investigate the clinical significance of circRNA-100876 in the clinicopathological parameters of Cc patients. Moreover, the expression of circRNA-100876 was inhibited by small interfering RNAs (siRNAs) in loss-of-function assay. Finally, the invasion ability of Cc cells was determined by transwell assay. RESULTS: The results of this study manifested that circRNA-100876 was abnormally overexpressed in Cc tissues and cell lines, and the high expression of circRNA-100876 was clearly associated with the Clinical stage, T classification and Lymph node metastasis of Cc patients. Besides, Cc patients with high expression worsened overall survival. In addition, it was demonstrated that the inhibition of circRNA-100876 reduced the invasion ability of Cc cells. CONCLUSIONS: Acting as a tumor promoter, circRNA-100876 might be regarded as a new potential biomarker for the diagnosis and therapy of Cc.

[Associations of parental thalassemia with preterm birth and low birth weight].

Objective: To investigate the association between the preterm birth and low birth weight and parental thalassemia. Methods: Pregnant women and their husbands receiving prenatal examination in local hospitals or maternal and child health centers in Jingxi and Debao in Guangxi from January to December 2017 were selected as study subjects. A total of 758 pregnant women with pregnancy outcomes and their husbands, who were both or alone diagnosed with thalassemia through thalassemia gene detection, were selected as case group and 758 pregnant women with pregnancy outcomes and their husbands, who were negative in thalassemia gene detection and hemoglobin electrophoresis test were selected as control groups. The case group were further divided into mother group, father group and both mother and farther group. Clinical and pregnancy outcome data of the study subjects were collected for the analysis on the association between parental thalassaemia and preterm birth or low birth weight by the independent sample t test, χ(2) test and Cox regression analysis. Results: The incidence of preterm birth in case group and control group was about 6.5% and 1.6% and the incidence of low birth weight in case group and control group was about 7.3% and 0.8%. After adjusting for possible confounding factors, Cox regression analysis results showed that mother suffering from thalassemia (aRR=3.45, 95%CI: 1.35-8.81, P=0.010), fathers suffering from thalassemia (aRR=4.93, 95%CI: 2.16-11.21, P<0.001) and both mother and farther suffering from thalassemia (aRR=5.13, 95%CI: 2.62-10.04, P<0.001) were associated with preterm birth. Mother suffering from thalassemia (aRR=12.98, 95%CI: 4.91-34.30, P<0.001), fathers suffering from thalassemia (aRR=9.40, 95%CI: 3.40-25.95, P<0.001) and both mother and farther suffering from thalassemia (aRR=10.74, 95%CI: 4.44-26.00, P<0.001) were associated with low birth weight. The newborn whose parent all suffered from thalassemia had higher risks for preterm birth (χ(2)=22.72, P<0.001)and low birth weight (χ(2)=34.03, P<0.001) compared with those only with mother or father suffering from thalassemia. Conclusion: Parental thalassaemia, including both sides and single side, might increase the risks of preterm birth and low birth weight for newborn, and the risks might be higher in newborn with both mother and father suffering from thalassaemia.

[Dose-response relationship between maternal hemoglobin concentration and preterm birth, in pregnant women].

Objective: To investigate the dose-response relationship between hemoglobin concentration and preterm birth, during pregnancy. Methods: With Zhuang ethnicity, a total of 12 780 pregnant women and their infants that admitted to Wuming、Pingguo、Jingxi、Debao、Longan and Tiandong hospitals, were recruited, in Guangxi Zhuang Autonomous Region, from January 2015 to December 2017. Non-conditional logistic regression method was used to analyze the effect of anemia on preterm birth during pregnancy. Dose-response relationship between hemoglobin concentration and preterm birth was explored, using the restrictive cubic spline model. Results: After excluding 2 053 pregnant women with hypertension or aged 35 years and over, results from the non-conditional logistic regression analysis showed that the risk of preterm birth in the anemia group was 1.29 times (OR=1.29, 95%CI: 1.04-1.59, P=0.019) of the non-anemia group in the first trimester. Data from the restricted cubic sample showed that there appeared nonlinear "L" dose-response relationship between hemoglobin concentration and preterm birth in the first trimester and "U" shape in the third trimester (non-linearity test P<0.001). Conclusion: There appeared nonlinear dose-response relationship between the hemoglobin concentration and preterm birth, both in the first and third trimesters.

[Value of dual-energy CT-based volumetric iodine-uptake in the evaluation of chemotherapy efficacy in advanced gastric cancer].

Objective: To explore the value of dual-energy CT-based volumetric iodine-uptake (VIU) in the evaluation of chemotherapy efficacy in advanced gastric cancer. Methods: Inclusion criteria of subjects: (1) without previous systematic therapy; (2) with complete clinical information before and after chemotherapy; (3) without contraindications of chemotherapy. Exclusion criteria of subjects: (1) unfinished duration and times of chemotherapy; (2) unmeasurable primary lesions; (3) poor imaging quality or poor gastric filling. Clinical and image data of 52 patients with advanced gastric cancer who were diagnosed by pathology from gastroscopic biopsy, and needed chemotherapy evaluated by imaging and clinical information in the First Affiliated Hospital of Wenzhou Medical University from February 2017 to February 2018 were collected and analyzed. Of 52 patients, 38 were male and 14 were female with the median age of 65 (31-88) years old. All the patients underwent a dual-energy, dual phase-enhanced CT scanning before chemotherapy and after the third chemotherapy session. The parameters of the lesions measured before and after chemotherapy in portal vein phase were as follows: the maximum diameter (the largest diameter among those measured in the cross-sectional, coronal, and sagittal planes), average CT value (the regions of interest were manually pinpointed under cross-sectional planes with largest diameter of the tumor, which did not include regions less than 2 mm to the edge of the tumor) and VIU (lesion volume × iodine concentration). The change rates of maximum lesion diameter, average CT value and VIU before and after chemotherapy were calculated [(post-chemotherapy parameters-pre-chemotherapy parameters)/ pre-chemotherapy parameters]. The efficacy of chemotherapy was evaluated by RECIST 1.1 (the change of maximum tumor diameter after chemotherapy), Choi (the change of average CT value after chemotherapy) and VIU (the change of VIU after chemotherapy), respectively, which was categorized by complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). Patients with CR, PR, and SD were assigned to the effective group, while those with PD were classified as the ineffective group. Paired t - test or Wilcoxon signed ranks test was used to compare the changes of parameters before and after chemotherapy, whereas Spearman correlation analysis and Kappa test were used for the correlation analysis and the consistency test between the three evaluation criteria (Kappa≥0.75 indicated good consistency). Results: After chemotherapy, the average CT value [(74.01±16.75) HU vs. (81.06±15.87) HU, t=2.202, P=0.030] and median VIU (668.53×10(2) µg vs. 272.52×10(2) µg, Z=4.761, P<0.001) decreased significantly, while the difference of the maximum diameter was not statistically significant [(66.71±34.49) mm vs. (78.45±35.62) mm, t=1.708, P=0.091]. The median change rate of VIU (-53.33%) was greater than that of CT values (-5.75%) with significant difference (Z=-5.408, P<0.001). According to the RECIST 1.1 criteria, 47 patients (90.4%, including 19 with PR and 28 with SD) were effective and 5 patients (9.6%) were ineffective. According to the Choi criteria, 45 patients (86.5%, including 37 with PR and 8 with SD) were effective and 7 patients (13.5%) were ineffective. According to the VIU criteria, 46 patients (88.5%, including 41 with PR and 5 with SD) were effective and 6 patients (11.5%) were ineffective. Efficacy comparison among these three criteria showed no significant difference (χ(2)=0.377, P=0.828). As compared to RECIST 1.1 evaluation, the proportion of PR evaluated by Choi and VIU was significantly higher (χ(2)=16.861, P<0.001), whereas the proportion of SD was significantly lower (χ(2)=24.089, P<0.001). There was no significant difference in the proportions of PR and SD between VIU and Choi criteria (χ(2)=0.887, P=0.346). Consistency and correlation analysis showed that the VIU and Choi evaluation criteria presented the highest consistency and correlation (Kappa=0.912, P<0.001; r=0.916, P<0.001). Conclusion: VIU is a feasible parameter for the evaluation of chemotherapy efficacy in advanced gastric cancer, and may be more sensitive than the evaluation criteria based on maximum diameter or change of CT value in the tumor.

Identification of RASSF1A modulated genes in nasopharyngeal carcinoma.

RASSF1A is a tumor suppressor gene on 3p21.3 frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma (NPC). To identify RASSF1A target genes in NPC, we have investigated the expression profile of the stable RASSF1A transfectants and controls by high-density oligonucleotide array. A total of 57 genes showed differential expression in the RASSF1A-expressing cells. These RASSF1A target genes were involved in multiple cellular regulatory processes such as transcription, signal transduction, cell adhesion and RNA processing. The RASSF1A-modulated expression of eight selected genes with the highest fold changes (ATF5, TCRB, RGS1, activin betaE, HNRPH1, HNRPD, Id2 and CKS2) by RASSF1A was confirmed in both stable and transient transfectants. Compared with the RASSF1A transfectants, an inverse expression pattern of activin betaE, Id2 and ATF5 was shown in the immortalized nasopharyngeal epithelial cells treated with siRNA against RASSF1A. The findings imply that the expression of activin betaE, Id2 and ATF5 was tightly regulated by RASSF1A and may associate with its tumor suppressor function. Strikingly, overexpression of Id2 is common in NPC and RASSF1A-induced repression of Id2 was mediated by the overexpression of activin betaE. The results suggest a novel RASSF1A pathway in which both activin betaE and Id2 are involved.

[Efficacy and safety of IA regimen containing different doses of idarubicin in de-novo acute myeloid leukemia for adult patients].

Objective: To investigate the efficacy and safety of IA regimen which contains idarubicin (IDA) 8 mg/m(2), 10 mg/m(2) or 12 mg/m(2) as induction chemotherapy for adult patients with de-novo acute myeloid leukemia (AML) . Methods: A total of 1 215 newly diagnosed adult AML patients, ranging from May 2011 to March 2015 in the First Affiliated Hospital of Soochow University and other 36 clinical blood centers in China were enrolled in the multicenter, single-blind, non-randomized, clinical controlled study. To compare the response rate of complete remission (CR) , adverse events between different dose idarubicin combined with cytarabine (100 mg/m(2)) as induction chemotherapy in newly diagnosed patients of adult AML. Results: Of 1 207 evaluable AML patients were assigned to this analysis of CR rate. The CR rates of IDA 8 mg/m(2) group, IDA 10 mg/m(2) group and IDA 12 mg/m(2) group were 73.6% (215/292) , 84.1% (662/787) and 86.7% (111/128) , respectively (P<0.001) . After adjusted for age, blast ratio of bone marrow, FAB classification and risk stratification, the odds ratios (95% CI) of IDA 10 mg/m(2) group and IDA 12 mg/m(2) group were 0.49 (0.34-0.70) and 0.36 (0.18-0.71) , as compared with the IDA 8 mg/m(2) group (P<0.001, P=0.003) . In the intermediate and favorable groups, CR rates was 76.5% (163/213) , 86.9% (506/582) and 86.1% (68/79) in different doses of IDA (P=0.007) . Interestingly, IA regimen with IDA 10 mg/m(2) was the only beneficial factor affecting CR in this group after adjusted for age, blast ratio of bone marrow and FAB classification[OR=0.47 (95% CI 0.31-0.71) , P<0.001]. CR rates in adverse group was 50.0% (18/36) , 60.6% (43/71) and 81.8% (18/22) respectively (P=0.089) . However, the odds ratios (95% CI) of IDA 12 mg/m(2) when compared with the IDA 8 mg/m(2) was 0.22 (0.06-0.80) , after adjusted for age, blast ratio of bone marrow and FAB classification. The median time (days) of neutrophil count less than 0.5×10(9)/L in IDA 8 mg/m(2) group, IDA 10 mg/m(2) group and IDA 12 mg/m(2) group were 14 (11-18) , 15 (11-20) and 18 (14-22) , respectively (P=0.012) and of platelet count lower than 20×10(9)/L were 14 (7-17) , 15 (11-20) and 17 (15-21) , respectively (P=0.001) . The incidences of lung infection in the three groups were 9.8%, 13.5% and 25.2%, respectively (P<0.001) . Conclusions: For young adult patients (aged 18-60 years) with AML in China, intensifying induction therapy with idarubicin 10 mg/m(2) is clinically superior to IDA 8 mg/m(2) and IDA 12 mg/m(2) in favorable intermediate AML subgroup. However, idarubicin 12 mg/m(2) is more suitable to adverse AML subgroup.

p16 gene alterations in nasopharyngeal carcinoma.

In order to investigate the p16 gene alterations in nasopharyngeal carcinoma (NPC), we have examined for mutations and deletions of the p16 gene in samples of NPC including 3 cell lines, 3 xenografts, and 20 primary tumors with matched blood DNA as controls. Using single-strand conformation polymorphism and direct sequencing analysis, no p16 gene mutations were detected in the NPC primary tumors and xenografts. Mutations of the p16 gene were found in three NPC cell lines, but no normal allele was present in these samples. Homozygous deletion of the p16 gene has been identified in 2 (67%) of 3 cases of NPC xenografts and 7 (35%) of 20 cases of primary tumors by comparative multiplex PCR analysis. A homozygous deletion region distal to the p16 locus was observed in a case of NPC primary tumor. Our data document for the first time that alterations of the p16 gene were frequent in NPC and that homozygous deletion was the major mechanism for the inactivation of this gene. These findings suggest that complete inactivation of the p16 gene may play a role in the development of NPC. Moreover, inactivation of other putative tumor suppressor gene(s) outside of the p16 locus within chromosome 9p21-22 may also contribute to the pathogenesis of this disease.

Dexamethasone inhibition of rat hepatoma growth and alpha-fetoprotein synthesis.

The effect of dexamethasone on hepatoma growth and differentiation, as well as the production of alpha-fetoprotein (AFP) and albumin, was investigated. Treatment of rats with dexamethasone strongly reduced (by 83 to 98%) the serum levels of AFP in rats bearing Morris hepatomas 7777, 8994, 7288c , and 9618A2 . Reduced AFP levels were due in part to a large reduction in tumor load in dexamethasone-treated rats. Hepatoma weights, on the average, were reduced by 64 to 90% relative to controls, while a large bowel transplantable tumor was affected only slightly. Lower serum AFP levels in rats with hepatomas 7777, 8994, and 9618A2 also resulted from reduced AFP synthesis, as indicated by lower cytoplasmic AFP levels. Cytoplasmic albumin levels were higher in dexamethasone-treated rats bearing hepatomas 7777, 8994, and 7288c than they were in rats which did not receive dexamethasone. RNA dot hybridization also indicated that dexamethasone reduced the amount of AFP mRNA in hepatoma 7777 while increasing albumin mRNA. Two-dimensional gel electrophoresis of tumor cytosol proteins showed that dexamethasone reduced synthesis of all AFP variants which could be detected by this technique. A number of abundant hepatoma-associated and liver-associated proteins were not significantly affected by dexamethasone.

Molecular prognostication of nasopharyngeal carcinoma by quantitative analysis of circulating Epstein-Barr virus DNA.

We investigated the prognostic implication of pretreatment plasma/serum EBV DNA concentration, as measured by real-time quantitative PCR, in nasopharyngeal carcinoma (NPC). In 91 prospectively recruited NPC patients, those with recurrence or metastasis within the first year after treatment had a higher median plasma EBV DNA concentration than those without events (41,756 copies/ml versus 5,807 copies/ml; P < 0.001, Mann-Whitney rank-sum test). In multivariate logistic regression analysis, plasma EBV DNA was an independent prognostic indicator for early clinical events [relative risk = 3.8 (95% confidence interval, 1.6-9.2 for each 10-fold increase in plasma EBV DNA concentration; P = 0.003)]. In a second cohort of 139 NPC patients followed-up for a median period of 2,027 days (interquartile range, 597-2,335 days), serum EBV DNA was found to be a significant variable associated with NPC-related death in multivariate Cox's regression analysis [relative risk = 1.6 (95% confidence interval, 1.1-2.1 for each 10-fold increase in serum EBV DNA concentration; P = 0.007)]. The quantitation of circulating EBV DNA may thus allow improved prognostication of NPC.

Loss of heterozygosity on the long arm of chromosome 11 in nasopharyngeal carcinoma.

Loss of heterozygosity (LOH) on the long arm of chromosome 11 had been reported in many types of solid tumors. In this study, we investigated the LOH patterns of chromosome 11 on 52 primary nasopharyngeal carcinomas using 10 microsatellite polymorphic markers. The results revealed that 28 of the 52 cases (53.8%) demonstrated LOH on at least one of the nine 11q microsatellite loci studied. The highest frequencies of LOH were found at the two loci D11S2000 (36.1%) and D11S934 (34.5 %), both located at 11q22-24. Two distinct regions of deletion were found at 11q, with the first one defined by INT-2 and D11S900 at 11q13.3-22, and the second region located between D11S2000 and D11S934 at 11q22-24. The two deletion regions overlap with the common areas of deletion reported in other tumor types. This suggests the presence of multiple putative tumor suppressor genes on chromosome 11q that may play a role in the development of nasopharyngeal carcinomas.

Kinetics of plasma Epstein-Barr virus DNA during radiation therapy for nasopharyngeal carcinoma.

We studied the kinetics of circulating EBV DNA in the plasma of nasopharyngeal carcinoma (NPC) patients. Serial weekly sampling of 10 NPC patients revealed a rapid decline in plasma EBV DNA concentration after treatment. In two subjects, an initial rise in the circulating EBV DNA level was observed immediately after treatment initiation. Plasma EBV DNA levels were monitored daily during the first treatment week in a second cohort of five patients, and the results indicated that an initial rise in plasma EBV DNA concentration could be observed in all subjects during the first treatment week. This observation is consistent with the liberation of EBV DNA after therapy-induced cancer cell death. After this initial rise, plasma EBV DNA concentration was found to decay with a median half-life of 3.8 days (interquartile range, 2.4-4.4 days). Kinetic analysis of circulating tumor-derived DNA during treatment may be a powerful tool for evaluating the in vivo response of NPC and other tumors to antineoplastic treatment and may improve our understanding of the biology of plasma nucleic acids.

High resolution allelotype of microdissected primary nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a common cancer in South China but is rare in other parts of the world. To better understand the molecular basis of this cancer, we performed high-resolution allelotyping on 27 microdissected primary tumors using 382 microsatellite markers. We have detected high frequencies of allelic imbalance on 3p (96.3%), 9p (85.2%), 9q (88.9%), 11q (74.1%), 12q (70.4%), 13q (55.6%), 14q (85.2%), and 16q (55.6%). Nonrandom allelic changes of 12q and 16q were revealed for the first time. In addition, loss of heterozygosity on chromosomal arms 1p (37.0%), 5q (44.4%), and 12p (44.4%) were also common in NPC. Multiple minimally deleted regions, 7-40 cM, were identified at 3p14-24.2, 11q21-23, 13q12-14, 13q31-32, 14q24-32, and 16q22-23. Frequent deletions of these minimally deleted regions implied the presence of tumor suppressor genes that may be involved in the development of NPC. Consistent loss of heterozygosity on 3p, 9p, and 14q in almost all tumors suggested that such changes are critical events in NPC tumorigenesis.

Absence of p53 gene mutations in primary nasopharyngeal carcinomas.

Alterations in the p53 tumor suppressor gene and Epstein-Barr virus status were investigated in 15 nasopharyngeal carcinoma (NPC) biopsies, 4 xenografts, and 2 cell lines from the Cantonese region of southern China. One other established NPC cell line obtained from a northern Chinese patient was also studied. Restriction fragment length polymorphism analysis revealed a loss of heterozygosity for chromosome 17p, where the p53 gene resides, in only one of 15 NPC biopsies. Polymerase chain reaction-single-stranded conformational polymorphism analysis and direct sequencing failed to detect sequence alterations in exons 5 through 8 of the p53 gene in the 15 tumors and in the 4 NPC xenografts, all of which tested positive for Epstein-Barr virus. In contrast, the 3 NPC cell lines were all negative for Epstein-Barr virus and contained G----C transversions in the p53 gene, with cell lines CNE-1 and CNE-2 harboring identical AGA (arginine) to ACA (threonine) changes at codon 280. These results suggest that p53 inactivation is not a necessary component of nasopharyngeal carcinogenesis in Cantonese but may be important in the establishment of cell lines derived from these tumors.

Hypermethylation of the p16 gene in nasopharyngeal carcinoma.

We have recently reported that inactivation of the p16 gene by mutation and deletion is common in nasopharyngeal carcinoma (NPC). The present study demonstrates that hypermethylation of the 5' CpG island can serve as an alternative mechanism for inactivation of the p16 gene in this tumor. Using Southern blotting analysis and multiplex PCR, aberrant methylation of the 5' CpG island of the p16 gene was found in a NPC xenograft (xeno-666) and 6 (22%) of 27 primary tumors, but not in normal tissues of the nasopharynx. In the NPC xenograft (xeno-666) and its newly derived cell line (cell-666), both showing hypermethylation of the p16 gene, no p16 gene expression was found. After treatment with 5-aza-2'-deoxycytidine, reexpression of the p16 gene was detected in the cell line cell-666. These findings suggest that aberrant methylation of the 5' CpG island may participate in the transcriptional inactivation of the p16 gene in NPC. The present results further support that the p16 gene is the critical target on chromosome 9p21 for inactivation during the development of this disease.