Nasopharyngeal carcinoma as a paradigm of cancer genetics

Human glutathione peroxidase codon 198 variant increases nasopharyngeal carcinoma risk and progression

PURPOSE

Glutathione peroxidase 1 (GPx-1) is a selenium-dependent detoxifying enzyme involved in the protection of cells against oxidative damage. Some genetic association studies reported significant associations between GPx-1 Pro198Leu variant and carcinogenesis across different populations; however, the impact of this variant on nasopharyngeal carcinoma (NPC) has not been explored. Therefore, the present study was planned to evaluate the potential involvement of the GPx-1 Pro198Leu variant and plasma GPx activity in the risk of developing NPC in a Tunisian population.

METHODS

The GPx-1 Pro198Leu genotype was determined in 327 NPC patients and 150 healthy controls by the RFLP-PCR analysis. The correlation between the GPx-1 variant and the clinicopathological parameters was examined. GPx activity was assessed in the plasma of 119 NPC patients and 58 healthy control subjects and according to GPx-1 genotypes and clinicopathological characteristics of NPC patients.

RESULTS

A significant association was found between GPx-1 Pro198Leu variant and NPC risk in a Tunisian population. The allelic frequencies of Pro and Leu alleles were 32% versus 68% and 41% versus 59% in NPC cases and controls, respectively. Thus, the minor 198 Leu allele increased significantly in NPC patients and appeared as a potential risk factor for NPC occurrence (OR = 1.48, CI 95% = 1.14-1.91, p = 0.002). The plasma GPx activity was significantly higher in NPC patients than in controls (p = 0.03). According to the clinicopathological characteristics of NPC patients, GPx activity decreased significantly in patients with lymph node metastasis (p = 0.004).

CONCLUSION

This is the first study showing a strong association between GPx-1 Pro198Leu genetic variant and NPC risk. GPx-1 Pro198Leu variant increased the development of regional lymph node metastasis. Plasma GPx activity was higher in NPC patients. Thus, GPx-1 gene could be considered as a determinant factor influencing NPC risk and progression.

Rare tumors: Retinoblastoma, nasopharyngeal cancer, and adrenocorticoid tumors

The role of surgery, chemotherapy, and radiation therapy for retinoblastoma has evolved considerably over the years with the efficacy of intraarterial chemotherapy and the high incidence of secondary malignant neoplasms following radiation therapy. The use of spot scanning intensity-modulated proton therapy may reduce the risk of secondary malignancies. For pediatric nasopharyngeal carcinoma, the current standard of care is induction chemotherapy followed by chemoradiation therapy. For adrenocortical carcinoma, the mainstay of treatment is surgery and chemotherapy. The role of radiation therapy remains to be defined.

Transcriptome Profile of Next-Generation Sequencing Data Relate to Proliferation Aberration of Nasopharyngeal Carcinoma Patients in Indonesia

OBJECTIVE

Nasopharyngeal carcinoma (NPC) is the most common cancer arising from epithelial cells of the nasopharynx in  Indonesia. This study aims to determine the differential level of gene expression in NPC patients when compared with normal individuals. Transcriptome profiling analysis was performed using RNA-Seq technology to determine the differential gene expression relate to proliferation aberration that occurs in NPC patients compared with normal individuals. So we get the transcriptomic profile of Indonesia NPC patients.

METHODS

In this study, we used 9 samples, 7 NPC samples and 2 normal samples as control.  Fresh tissue of tumor samples was collected from biopsy, and normal samples were collected brushing technique. The total RNA was isolated from fresh tissue samples and brushing samples using the Rneasy® RNA Extraction Mini Kit. The cDNA library was generated using TruSeq® RNA Library Preparation Kit V2, and its concentration was determined using qPCR. The library was sequenced using the Next-Generation Sequencing (NGS) Illumina Next Seq 550 platform. The raw sequence data quality was analyzed using FastQC and interpreted using HISAT2, HTSeq, edgeR, and PANTHER.

RESULTS

From the analysis, 25493 gene transcripts were expressed, with 1956 genes were significantly upregulated, 90 genes were significantly downregulated in NPC samples, and 23897 genes didn't change the expression level significantly (p <0.05), 10 of which genes were associated with cell proliferation. These genes are involved in the regulation of cancer cell proliferation through several signaling pathways, which are the apoptosis signaling pathway, IGF signaling pathway, Notch signaling pathway, and P13K signaling pathway.

CONCLUSION

There were significant differences in gene expression levels between NPC patients and normal individuals. Each gene that has changed the expression level plays a role in regulating various pathways that lead to cell proliferation aberration in NPC cases.

Pediatric Nasopharyngeal Carcinoma: A Rare Tumor in a Developing Country-What Do We Learn?

BACKGROUND/AIM

Nasopharyngeal carcinoma (NPC) is rare in children, accounting for 1% of pediatric malignancies. The 5-fluorouracil Cisplatin regimen could be considered as a standard of care induction chemotherapy followed by concomitant chemoradiotherapy. This study aimed at detecting the survival outcome in correlation with different prognostic factors together with the toxicity of different treatment modalities.

PATIENTS AND METHODS

This was a retrospective study carried out from 2007 to 2016 that included all NPC patients below 18 years treated at the National Cancer Institute, Egypt.

RESULTS

A total of 21 patients were included with a median follow-up period of 33.9 months. The median age was 14.8 years (range: 9 to 18). All patients were treated by neoadjuvant chemotherapy with cisplatin and 5- fluorouracil, followed by concurrent radiotherapy (median dose: 61.2 Gy) and cisplatin as a radiosensitizer. After induction chemotherapy, the response rate was 53%. After completion of treatment, 67% had a complete response; partial response was seen in 14%; and progressive disease was seen in 19%. By the end of the study, 7 (33.3%) patients had progression/relapse; 4 of them died from disease. The 3-year overall survival and event-free survival were 85.7% and 66.7%, respectively.

CONCLUSIONS

Neoadjuvant chemotherapy followed by concurrent chemoradiotherapy was an effective strategy in the treatment of pediatric NPC with good overall survival and event-free survival. High systemic failure (33.3%) remains another challenge to solve. More efforts should be made to improve survival by developing more efficient systemic treatment modalities, especially for progressive/relapsed disease. Multicenter studies on a larger number of patients are needed to identify different prognostic factors and standardize treatment strategies.

X-chromosome association study reveals genetic susceptibility loci of nasopharyngeal carcinoma

Background

The male predominance in the incidence of nasopharyngeal carcinoma (NPC) suggests the contribution of the X chromosome to the susceptibility of NPC. However, no X-linked susceptibility loci have been examined by genome-wide association studies (GWASs) for NPC by far.

Methods

To understand the contribution of the X chromosome in NPC susceptibility, we conducted an X chromosome-wide association analysis on 1615 NPC patients and 1025 healthy controls of Guangdong Chinese, followed by two validation analyses in Taiwan Chinese (n = 562) and Malaysian Chinese (n = 716).

Results

Firstly, the proportion of variance of X-linked loci over phenotypic variance was estimated in the discovery samples, which revealed that the phenotypic variance explained by X chromosome polymorphisms was estimated to be 12.63% (non-dosage compensation model) in males, as compared with 0.0001% in females. This suggested that the contribution of X chromosome to the genetic variance of NPC should not be neglected. Secondly, association analysis revealed that rs5927056 in DMD gene achieved X chromosome-wide association significance in the discovery sample (OR = 0.81, 95% CI 0.73–0.89, P = 1.49 × 10⁻⁵). Combined analysis revealed rs5927056 for DMD gene with suggestive significance (P = 9.44 × 10⁻⁵). Moreover, the female-specific association of rs5933886 in ARHGAP6 gene (OR = 0.62, 95%CI: 0.47–0.81, P = 4.37 × 10⁻⁴) was successfully replicated in Taiwan Chinese (P = 1.64 × 10⁻²). rs5933886 also showed nominally significant gender × SNP interaction in both Guangdong (P = 6.25 × 10⁻⁴) and Taiwan datasets (P = 2.99 × 10⁻²).

Conclusion

Our finding reveals new susceptibility loci at the X chromosome conferring risk of NPC and supports the value of including the X chromosome in large-scale association studies.

Electronic supplementary material

The online version of this article (10.1186/s13293-019-0227-9) contains supplementary material, which is available to authorized users.

Reproductive history and risk of nasopharyngeal carcinoma: A population-based case-control study in southern China

OBJECTS

Nasopharyngeal carcinoma (NPC) incidence exhibits a remarkable sex disparity, with higher risk among males. Whether this pattern can be partly explained by female reproductive history is unclear.

METHODS

A population-based case-control study of NPC was conducted in southern China between 2010 and 2014, including 674 histopathologically verified female NPC cases and 690 female controls randomly selected from population-based registries. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression after adjusting for potential confounders.

RESULTS

Women who had 3, 4, or ≥5 pregnancies compared with 2 pregnancies were at significantly increased risk for NPC (ORs 1.56, 1.45 and 1.88, respectively). History of deliveries was similarly associated with a greater risk of NPC. These positive associations were more prominent in women who were younger than 50 years, had less than 10 years of education, or were white-collar workers. Increasing time since menopause was associated with a diminished NPC risk (P_trend = 0.010). Women more than 15 years after menopause had a 0.35-fold (95% CI: 0.16-0.75) NPC risk compared with those 0-3 years after menopause.

CONCLUSION

Contrary to our hypothesis, a history of pregnancy or delivery increased the risk of NPC and the risk decreased with increasing time since menopause. However, the non-linear relationship and no consistent risk patterns across strata indicate that the observed associations are unlikely to be causal, and may at least partially be ascribed to residual confounding by socioeconomic factors.

Dinitrosopiperazine-decreased PKP3 through upregulating miR-149 participates in nasopharyngeal carcinoma metastasis

Nasopharyngeal carcinoma (NPC) has a high metastatic clinicopathological feature. As a carcinogen factor, N,N'-dinitrosopiperazine (DNP) is involved in NPC metastasis, but its precise mechanism has not been fully elucidated. Herein, we showed that DNP promotes NPC metastasis through upregulating miR-149. DNP was found to decrease Plakophilin3 (PKP3) expression, further DNP-decreased PKP3 was verified to be through upregulating miR-149. We also found that DNP induced proliferation, adhesion, migration and invasion of NPC cell, which was inhibited by miR-149-inhibitor. DNP may promote NPC metastasis through miR-149-decreased PKP3 expression. Therefore, DNP-increased miR-149 expression may be an important factor of NPC high metastasis, and miR-149 may serve as a molecular target for anti-metastasis therapy of NPC.

Childhood Nasopharyngeal Carcinoma: State-of-the-Art, and Questions for the Future

In children, nasopharyngeal carcinoma (NPC) is a very rare tumor, mostly Epstein-Barr Virus related and quite always diagnosed at a locally advanced stage. With current protocols associating induction cisplatin-based chemotherapy and concomitant chemoradiotherapy, prognosis is excellent with overall survival higher than 85%. However, long-term toxicities are frequent. Improvement in radiation therapy modalities like intensity-modulated radiation therapy and new strategies with radiation dose adaptation to chemotherapy response have been introduced to reduce acute and long-term toxicities. Actually, 2 main questions remain: is it possible to pursue a therapeutic deescalation in children with low-risk NPC or very good response to induction chemotherapy in order to reduce the risk of late effects? Could an immunologic maintenance treatment improve prognosis of children with high-risk NPC? International collaborative groups and prospective trials including biological studies are necessary to answer these questions to improve childhood NPC treatment and knowledge.

Risk factors and clinical outcomes of pediatric liver transplant recipients with post-transplant lymphoproliferative disease in a multi-ethnic Asian cohort

BACKGROUND

We aimed to evaluate clinical characteristics, risk factors, and disease outcomes for liver transplant recipients (LTR) with post-transplant lymphoproliferative disease (PTLD) at our center.

METHODS

Retrospective review of data of all pediatric LTR (1991-2015) was conducted.

RESULTS

The overall incidence of PTLD was 16.4% (18/110), the majority (13/18) were early lesions, while 3/18 were polymorphic/monomorphic PTLD. The risk factors significant on univariate analysis were as follows: mean age (years) at transplant (1.66 vs 4.76, P = .006); age <2 years at transplant (odds ratio [OR] 3.53 [95% confidence interval [CI]: 1.16-10.73], P = .026); cytomegalovirus (CMV) primary infection (OR 11.39 [95% CI: 3.44-37.7], P < .001); recipient CMV seronegativity (OR 7.50 [95% CI: 2.02-27.78], P = .003); presence of CMV end-organ disease (OR 4.00 [95% CI: 1.22-13.16], P = .022); Chinese ethnicity; and higher mean duration of intravenous ganciclovir prophylaxis. In multivariate analysis, CMV primary infection (OR 5.22 [95% CI: 1.25-21.87], P = .024), CMV seronegativity (OR 5.91 [95% CI: 1.13-30.90, P = .035]), and having acute cellular rejections (ACR) prior to PTLD (OR 5.53 [95% CI: 1.43-21.48, P = .013]) were significant risk factors for PTLD, with the latter two factors having a synergistic effect in increasing PTLD risk in a stratified analysis. The final multivariate model in predicting the risk of PTLD, utilizing CMV primary infection, recipient CMV seronegativity, and ACR before PTLD as predictive variables, was statistically significant (likelihood ratio chi square statistic = 25.18, P < .0001 with df = 3).

CONCLUSIONS

We report a unique clinicopathologic and risk factor profile in our cohort-early lesion PTLD accounts for the majority and the incidence of monomorphic PTLD remains low. In addition, we show a synergism between CMV naivety and ACR on PTLD risk, a higher prevalence of gastrointestinal manifestations, and a lack of significant association with Epstein-Barr virus seronegativity.

Knockdown of GRP78 enhances cell death by cisplatin and radiotherapy in nasopharyngeal cells

Radiotherapy and adjuvant cisplatin chemotherapy are the mainstream approaches in the treatment of nasopharyngeal carcinoma (NPC). These have been shown to effectively improve the outcome and reduce tumor recurrence. However, radiotherapy and chemotherapy resistance during the course of treatment has become more common recently, resulting in the failure of NPC therapy. Therefore, new therapeutic strategies or adjuvant drugs are urgently needed. The current study was designed to look for new treatment strategies or auxiliary drugs in the treatment of NPC. Two human NPC cell lines, HNE1 and HNE1/DDP, were used to examine the relationship between endoplasmic reticulum stress and cell resistance to ionizing radiation (IR) and cisplatin (DDP). Cell proliferation was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Meanwhile, propidium iodide (PI) staining and PI/Annexin V staining were used to observe cell apoptosis. Finally, western blot was used to detect the endogenous expression of glucose-regulated protein 78 (GRP78) and other apoptosis-related proteins. GRP78 small interference RNA was transfected using Lipofectamine 2000. Compared with HNE1/DDP, IR and DDP increased the cell apoptosis and inhibited the cell proliferation of HNE1. Inhibition of GRP78 can reverse IR and DDP resistance in NPC cells by PI/Annexin V staining. Knockdown of GRP78 upregulates the expression of pro-apoptotic proteins and downregulates the expression of antiapoptotic proteins. These results indicate that HNE1 is more sensitive to DDP and IR than HNE1/DDP. Knockdown GRP78 can reverse IR and DDP resistance in NPC cells. Inhibition of GRP78 gives us a new target to overcome resistance to radiotherapy and chemotherapy of NPC cells. Thus, this study should be further explored in vivo and assessed for possible clinical applications.

Familial aggregation of nasopharyngeal carcinoma in Taiwan

BACKGROUND

The incidence of nasopharyngeal carcinoma (NPC) is higher in Chinese than in Caucasian populations. Genetic, viral, and lifestyle factors may explain these ethnic differences in the incidence of NPC. In the present study, we examined the familial aggregation, heritability, and relative risks (RRs) of NPC using a nationwide database in Taiwan.

METHODS

A population-based family study was conducted using the Taiwan National Health Insurance Research Database. Participants included all individuals (N=23,422,955) registered with that database in 2013; of these, 17,653 had NPC. Among them, 47.45%, 57.45%, 47.29%, and 1.51% had a parent, child, sibling, and twin, respectively, with NPC.

RESULTS

Among the approximately 23 million Taiwan NHI beneficiaries in 2013, the relative risks (RRs) (95% confidence intervals) for NPC were 34.46 (5.12-231.77) for twins of the patients, 9.23 (6.34-13.43) for siblings, 3.80 (2.97-4.86) for parents, 3.74 (2.60-5.37) for offspring, and 1.78 (1.16-2.74) for spouses without genetic similarity. The mean age of onset in first-degree relative-affected NPC patients was 35.5years compared to 39.0years for NPC patients without affected first-degree relatives (p≤0.0001). Using a threshold liability model, the accountability for phenotypic variance of NPC was estimated to be 61.3% for genetic factors (heritability), 13.9% for shared environmental factors, and 24.8% for non-shared environmental factors. The probability of a patient with NPC to be sporadic was 82.8%.

CONCLUSION

This population-based analysis suggested a strong familial tendency in the development of NPC. Screening of first-degree relatives of NPC patients is recommended, particularly in endemic regions.

No association between TGF-β1 polymorphisms and risk of nasopharyngeal carcinoma in a large North African case-control study

Background

Genetic susceptibility plays a key role in the development of nasopharyngeal carcinoma (NPC) and in fact the disease presents with an unusually high incidence in certain regions of the world like North Africa. We investigated the association between polymorphism of the Transforming growth factor-β1 (TGF-β1) and risk of NPC in North Africa. TGF-β1 is a multifunctional cytokine that acts as both a tumor suppressor and a stimulator of cancer development; it has been shown to influence risk of numerous other carcinomas including lung, breast and prostate cancer.

Methods

TGF-β1 polymorphisms C-509T and T869C were studied in a large North African sample of 384 NPC cases and 361 controls, matched for age, sex and urban or rural residence in childhood. Genotypes were determined using polymerase chain reaction–restriction fragment length polymorphism.

Results

No association was observed between individual single nucleotide polymorphisms or their haplotypes and NPC susceptibility (for TGF-β1 C-509T: OR = 0.74; 95 % CI 0.46 − 1.18; for TGF-β1 T869C: OR = 0.86; 95 % CI 0.56 − 1.31), even when the samples were stratified by age, gender and TNM stage.

Conclusion

Contrary to what has been observed in Asian samples, in our North African sample, the TGF-β1 C-509T and T869C polymorphisms did not substantially influence NPC susceptibility.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-016-0337-8) contains supplementary material, which is available to authorized users.

Clusterin induced by N,N'-Dinitrosopiperazine is involved in nasopharyngeal carcinoma metastasis

Nasopharyngeal carcinoma (NPC) has a high metastatic clinicopathological feature. As a carcinogen factor, N,N'-Dinitrosopiperazine (DNP) is involved in NPC metastasis, but its precise mechanism has not been fully elucidated. Herein, we showed that DNP promotes NPC metastasis through up-regulating anterior clusterin (CLU). DNP was found to increase CLU, matrix metalloproteinases (MMP) 9 and vascular endothelial growth factor (VEGF) expression and activity, further DNP-increased MMP-9 and VEGF expression was through up-regulating CLU. We also found that DNP increased the binding of CLU with MMP-9 or VEGF. DNP induced the motility and invasion of NPC cell, which was inhibited by siRNA-CLU. The clinical investigation showed that CLU, MMP-9 and VEGF were positively correlated with the tumor-node -metastasis (TNM) classification. These results indicate that DNP may promote NPC tumor metastasis through up-regulating CLU, MMP-9 and VEGF expression. Therefore, DNP-increased CLU expression may be an important factor of NPC-high metastasis, and CLU may serve as a biomarker for NPC metastasis.

N,N'-dinitrosopiperazine-mediated AGR2 is involved in metastasis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) has a high metastatic character in the clinic, but its mechanism is not clear. As a carcinogen with organ specificity for the nasopharyngeal epithelium, N,N'-Dinitrosopiperazine (DNP) is involved in NPC metastasis. Herein, our data revealed that anterior gradient 2 (AGR2) was overexpressed in human NPC tissues, particularly in cervical lymph node metastatic NPC (LMNPC). High AGR2 expression was associated with NPC metastasis. Importantly, DNP induced AGR2 expression, and increased cell motility and invasion in the NPC cell line 6-10B. However, DNP-mediated cell motility and invasion was dramatically decreased when transfected with siRNA-AGR2. Further, AGR2 directly regulated cathepsin (CTS) B and D by binding them in vitro. These results indicate that DNP induces AGR2 expression, regulates CTSB and CTSD, increases cell motility and invasion, and promotes NPC tumor metastasis. Therefore, DNP-mediated AGR2 expression may be an important factor in prolific NPC metastasis.

Trends of cervical cancer in Greenland: a 60-year overview

BACKGROUND

Due to its extraordinarily fast economic and social transition, virtually closed borders before 1940 and, moreover, that 85% of the population has the distinctive genetics of the Inuit, Greenland is a very interesting country to study cervical cancer from a historical perspective. Nevertheless, little has been reported about long-term cancer trends in Greenland. Our aim was to describe and interpret the incidence of cervical cancer from 1950 to 2009.

MATERIAL AND METHODS

We systematically searched PubMed for articles reporting the incidence of cervical cancer in Greenland. We supplemented this with data for 1980-2009 obtained from the Chief Medical Officer of Greenland.

RESULTS

Incidence of cervical cancer was around 10 per 100 000 women (age-standardised, world population, ASW) in the 1950s, 30 per 100 000 in the 1960s, and in the 1980s around 60 per 100 000. From 1985 onwards, the incidence of cervical cancer started decreasing to the current level of 25 per 100 000.

CONCLUSION

The steep increase in the incidence of cervical cancer from the 1950s onwards is unlikely to be explained by increasing completeness of data. In parallel with the economic development, however, out-of-wedlock births (proxy for sexual behaviour) increased dramatically from 1935 onwards while tobacco use increased from the 1950s onwards. From the late 1960s to around 1990, data suggested rather stable but high levels of sexual habits. The decrease in the incidence of cervical cancer since 1985 is consistent with the introduction of screening. The data strongly suggested that the increased burden of cervical cancer in Greenlandic women was real and followed earlier changes in sexual behaviour; these changes were likely a consequence of the tremendous societal changes.

Inhibition of autophagy by 3-MA enhances endoplasmic reticulum stress-induced apoptosis in human nasopharyngeal carcinoma cells

Radiotherapy and adjuvant cisplatin chemotherapy are the mainstream treatments for nasopharyngeal carcinoma (NPC), which effectively improve the outcome and reduce tumor recurrence. However, the resistance mechanism(s) involved in radiotherapy and chemotherapy, which is the main barrier in NPC treatment, remains undefined. Therefore, there is an urgent requirement for the identification of new therapeutic strategies or adjuvant drugs. In the present study, the effects of autophagy inhibitors on endoplasmic reticulum (ER) stress-induced autophagy was investigated. Combining 3-methyladenine (3-MA) with cisplatin (DDP), ionizing radiation (IR), 2-deoxy-D-glucose (2-DG) or tunicamycin (TM) resulted in enhanced cell death, as revealed by MTT and colony formation assays. Flow cytometry results demonstrated that the sensitivity of NPC cells to DDP- and IR-induced apoptosis was not significant. DDP, IR, 2-DG and TM induced ER stress and autophagy. Using fluorescence microscopy, 3-MA was identified to increase the apoptotic cell death induced by DDP, IR, 2-DG or TM. In addition, 3-MA inhibited the increased autophagy induced by DDP, IR, 2-DG or TM, as demonstrated by western blot analysis and immunocytochemistry results. Results of the present study indicate that autophagy acts as a protective mechanism response to the apoptosis induced by DDP, IR, 2-DG or TM.

Proteomic analysis on N, N'-dinitrosopiperazine-mediated metastasis of nasopharyngeal carcinoma 6-10B cells

BACKGROUND

Nasopharyngeal carcinoma (NPC) has a high metastatic feature. N,N'-Dinitrosopiperazine (DNP) is involved in NPC metastasis, but its mechanism is not clear. The aim of this study is to reveal the pathogenesis of DNP-involved metastasis. 6-10B cells with low metastasis are from NPC cell line SUNE-1, were used to investigate the mechanism of DNP-mediated NPC metastasis.

RESULTS

6-10B cells were grown in DMEM containing 2H4-L-lysine and 13C 6 15 N4-L-arginine or conventional L-lysine and L-arginine, and identified the incorporation of amino acid by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Labeled 6-10B cells were treated with DNP at 0 -18 μM to establish the non-cytotoxic concentration (NCC) range. NCC was 0 -10 μM. Following treatment with DNP at this range, the motility and invasion of cells were detected in vitro, and DNP-mediated metastasis was confirmed in the nude mice. DNP increased 6-10B cell metastasis in vitro and vivo. DNP-induced protein expression was investigated using a quantitative proteomic. The SILAC-based approach quantified 2698 proteins, 371 of which showed significant change after DNP treatment (172 up-regulated and 199 down-regulated proteins). DNP induced the change in abundance of mitochondrial proteins, mediated the status of oxidative stress and the imbalance of redox state, increased cytoskeletal protein, cathepsin, anterior gradient-2, and clusterin expression. DNP also increased the expression of secretory AKR1B10, cathepsin B and clusterin 6-10B cells. Gene Ontology and Ingenuity Pathway analysis showed that DNP may regulate protein synthesis, cellular movement, lipid metabolism, molecular transport, cellular growth and proliferation signaling pathways.

CONCLUSION

DNP may regulate cytoskeletal protein, cathepsin, anterior gradient-2, and clusterin expression, increase NPC cells motility and invasion, is involved NPC metastasis.

Why are East Asians more susceptible to several infection-associated cancers (carcinomas of the nasopharynx, stomach, liver, adenocarcinoma of the lung, nasal NK/T-cell lymphomas)?

There are at least five cancers with uniquely high incidence amongst East and Southeast Asian ethnic groups - namely nasopharyngeal carcinoma (NPC); gastric carcinoma; hepatocellular carcinoma (HCC); adeno-carcinoma of the lung in female non-smokers and nasal NK/T-cell lymphomas. They all appear to be related to an infective cause (Epstein Barr Virus, Helicobacter pylori, hepatitis B virus). We hypothesize that a genetic bottleneck 30,000years ago at the Last Glacial Maximum could have resulted in unique genetic polymorphisms in Toll-like receptor 8, making East Asians more vulnerable to these infective associated cancers. This bottleneck could have been caused by the presence of malaria in the southern Himalayan conduit between central and East Asia; and only those with an attenuated innate immune response to the malarial parasite (perhaps reflected by the TLR8 polymorphism) were spared the ravages of cerebral malaria; allowing these people to cross into east Asia, but then rendering them susceptible to later endemic infections and their associated cancers.

The promoter methylation of the Syk gene in nasopharyngeal carcinoma cell lines

The aim of this study was to investigate the mRNA and protein expression levels of the Syk gene as well as its promoter methylation in nasopharyngeal carcinoma (NPC) cell lines. The CNE-1 (highly differentiated), CNE-2 (poorly differentiated) and NP69 (non-cancerous human immortalized nasopharyngeal epithelial cells) cell lines were used in the present study. The MS-PCR, Q-RT-PCR and western blotting methods were used to examine the Syk gene promoter methylation levels and mRNA and protein expression in the three cell lines. The promoter methylation levels in CNE-1, CNE-2 and NP69 cells were 36%, 62% and 0, respectively. The mRNA levels in CNE-1 and CNE-2 cells were 42±3.5 and 28±2% of that in NP69, respectively; the protein levels in CNE-1 and CNE-2 cells were 36±4.5 and 16±2.5 of that in NP69, respectively; the statistical differences between groups were significant. The lower differentiation levels of the NPC cell lines correlate with lower levels of mRNA and protein expression of the Syk gene, as well as higher promoter methylation levels.

High incidence of nasopharyngeal cancer: similarity for 60% of mitochondrial DNA signatures between the Bidayuhs of Borneo and the Bai-yue of Southern China

Populations in Southern China (Bai-yue) and Borneo (Bidayuh) with high incidence of nasopharyngeal cancer (NPC) share similar mitochondrial DNA signatures, supporting the hypothesis that these two populations may share the same genetic predisposition for NPC, which may have first appeared in a common ancestral reference population before the sea levels rose after the last ice age.

Sex difference in the incidence of nasopharyngeal carcinoma in Hong Kong 1983-2008: suggestion of a potential protective role of oestrogen

BACKGROUND

Nasopharyngeal carcinoma (NPC) shows a male predominance in incidence while the underlying reasons have rarely been explored.

METHODS

We analysed incident cases of NPC recorded in Hong Kong Cancer Registry during the period 1983-2008. All cases were divided into 5-year age groups. Age group specific incidence rates of NPC by sex and male to female ratios in incidence rate by age group were calculated. A curve fitting approach was taken to quantitatively describe the age-specific incidence rates of NPC using non-linear regressions.

RESULTS

During the period 1983-2008, a total of 27,579 new cases of NPC were identified (20,060 males and 7519 females) in Hong Kong. The overall male to female ratio of the annual age-standardised incidence rates of NPC ranged 2.2-3.1. The male to female ratio of NPC incidence increased with age until peaking at ages 55-59 years and showed a decline thereafter. An additional minor increase at ages 15-19 years was also observed. Modelling of the age-specific incidence curves suggested divergent slopes for men and women and a delay in increasing incidence with age among females, by around 5-10 years before menopause ages.

CONCLUSION

The age-dependent pattern of the sex difference in the incidence of NPC could not be completely explained by known risk factors for NPC. The contributions of intrinsic exposures, such as sex hormones, merit consideration and further investigations.

Lowered risk of nasopharyngeal carcinoma and intake of plant vitamin, fresh fish, green tea and coffee: a case-control study in Taiwan

BACKGROUND

A case-control study was conducted to evaluate the role of adult diet on nasopharyngeal carcinoma (NPC) in Taiwan.

METHODS

A total of 375 incident NPC cases and 327 controls matched to the cases on sex, age, and residence were recruited between July 1991 and December 1994. A structured questionnaire inquiring complete dietary history, socio-demographic characteristics, and other potential confounding factors was used in the personal interview. Unconditional logistic regression analysis was used to estimate multivariate-adjusted odds ratio (OR(adj)) with 95% confidence interval (CI) after accounting for known risk factors.

RESULTS

Fresh fish (OR(adj), 0.56; 95% CI, 0.38-0.83 for the highest vs. lowest tertile of intake), green tea (OR(adj), 0.61; 95% CI, 0.40-0.91 for drinking ≥1 times/week vs. never) and coffee (OR(adj), 0.56; 95% CI, 0.37-0.85 for drinking ≥0.5 times/week vs. never) were inversely associated with the NPC risk. No association with NPC risk was observed for the intake of meats, salted fish, fresh vegetables, fruits and milk. Intake of vitamin A from plant sources was associated with a decreased NPC risk (OR(adj), 0.62; 95% CI, 0.41-0.94 for the highest vs. lowest tertile).

CONCLUSION

The study findings suggest that certain adult dietary patterns might protect against the development of NPC.

Familial and large-scale case-control studies identify genes associated with nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy and has a remarkable geographic distribution, which is highly prevalent in southern China, Southeast Asia, and North Africa. Although most of the NPC are sporadic cases, the familial clustering of NPC has been demonstrated worldwide. Accumulating studies have proposed that the etiology of NPC is multi-stage and multi-factorial, involving genetic lesions, Epstein-Barr virus infection, and environmental exposure. Genetic variations result in differences in gene function, which in turn lead to different susceptibility to disease. Many studies have been carried out to dissect the genetic variants that contribute to NPC susceptibility. This article reviews the current progress of genetic studies to identify genes associated with NPC, focusing on the familial linkage and large-scale case-control study designs.

On the trails of markers and proxies: the socio-cognitive technologies of human movement, knowledge assemblage, and their relevance to the etiology of nasopharyngeal carcinoma

Bacteria, pigs, rats, pots, plants, words, bones, stones, earrings, diseases, and genetic indicators of all varieties are markers and proxies for the complexity of interweaving trails and stories integral to understanding human movement and knowledge assemblage in Southeast Asia and around the world. Understanding human movement and knowledge assemblage is central to comprehending the genetic basis of disease, especially of a cancer like nasopharyngeal carcinoma. The problem is that the markers and trails, taken in isolation, do not all tell the same story. Human movement and knowledge assemblage are in constant interaction in an adaptive process of co-production with genes, terrain, climate, sea level changes, kinship relations, diet, materials, food and transport technologies, social and cognitive technologies, and knowledge strategies and transmission. Nasopharyngeal carcinoma is the outcome of an adaptive process involving physical, social, and genetic components.