Milk Consumption Across Life Periods in Relation to Lower Risk of Nasopharyngeal Carcinoma: A Multicentre Case-Control Study

Background: The much higher incidence of nasopharyngeal carcinoma (NPC) in men suggests sex hormones as a risk factor, and dairy products contain measurable amounts of steroid hormones. Milk consumption has greatly increased in endemic regions of NPC. We investigated the association between NPC and milk consumption across life periods in Hong Kong.Methods: A multicentre case-control study included 815 histologically confirmed NPC incident cases and 1,502 controls who were frequency-matched on age and sex at five major hospitals in Hong Kong in 2014–2017. Odds ratios (ORs) of NPC (cases vs. controls) for milk consumption at different life periods were estimated by unconditional logistic regression, adjusting for sex, age, socioeconomic status score, smoking and alcohol drinking status, exposure to occupational hazards, family history of cancer, IgA against Epstein-Barr virus viral capsid antigen, and total energy intake.Results: Compared with abstainers, lower risks of NPC were consistently observed in regular users (consuming ≥5 glasses of milk [fresh and powdered combined] per month) across four life periods of age 6–12 (adjusted OR 0.74, 95% CI 0.54–0.86), 13–18 (0.68, 0.55–0.84), 19–30 (0.68, 0.55–0.84), and 10 years before recruitment (0.72, 0.59–0.87). Long-term average milk consumption of ≤2.5, >2.5, and ≤12.5, >12.5 glasses per month yielded adjusted OR (95% CI) of 1.00 (0.80–1.26), 0.98 (0.81–1.18), 0.95 (0.76–1.18), and 0.55 (0.43–0.70), respectively (all P-values for trend < 0.05).Conclusion: Consumption of milk across life periods was associated with lower risks of NPC. If confirmed to be causal, this has important implications for dairy product consumption and prevention of NPC

Review of the management of mucositis in the radiation treatment of head and neck cancer

© 2015 by Nova Science Publishers, Inc. Mucositis secondary to radiation in head and neck cancer is common. It has a negative impact on patient’s quality of life as well as various disease outcomes. A basic understanding of mechanism of its development and its proper assessment is essential in order to provide timely management.Link_to_subscribed_fulltex

Comparative methylome analysis in solid tumors reveals aberrant methylation at chromosome 6p in nasopharyngeal carcinoma

© 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd. Altered patterns of DNA methylation are key features of cancer. Nasopharyngeal carcinoma (NPC) has the highest incidence in Southern China. Aberrant methylation at the promoter region of tumor suppressors is frequently reported in NPC; however, genome-wide methylation changes have not been comprehensively investigated. Therefore, we systematically analyzed methylome data in 25 primary NPC tumors and nontumor counterparts using a high-throughput approach with the Illumina HumanMethylation450 BeadChip. Comparatively, we examined the methylome data of 11 types of solid tumors collected by The Cancer Genome Atlas (TCGA). In NPC, the hypermethylation pattern was more dominant than hypomethylation and the majority of de novo methylated loci were within or close to CpG islands in tumors. The comparative methylome analysis reveals hypermethylation at chromosome 6p21.3 frequently occurred in NPC (false discovery rate; FDR=1.33 × 10 -9 ), but was less obvious in other types of solid tumors except for prostate and Epstein-Barr virus (EBV)-positive gastric cancer (FDR < 10 -3 ). Bisulfite pyrosequencing results further confirmed the aberrant methylation at 6p in an additional patient cohort. Evident enrichment of the repressive mark H3K27me3 and active mark H3K4me3 derived from human embryonic stem cells were found at these regions, indicating both DNA methylation and histone modification function together, leading to epigenetic deregulation in NPC. Our study highlights the importance of epigenetic deregulation in NPC. Polycomb Complex 2 (PRC2), responsible for H3K27 trimethylation, is a promising therapeutic target. A key genomic region on 6p with aberrant methylation was identified. This region contains several important genes having potential use as biomarkers for NPC detection.Link_to_subscribed_fulltex

Female Breast Cancer Incidence among Asian and Western Populations: More Similar Than Expected

© 2015 Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US. Background: Previous reports suggested that female breast cancer is associated with earlier ages at onset among Asian than Western populations. However, most studies utilized cross-sectional analyses that may be confounded by calendar-period and/or birth cohort effects. We, therefore, considered a longitudinal (forward-looking) approach adjusted for calendar-period changes and conditioned upon birth cohort. Methods: Invasive female breast cancer data (1988-2009) were obtained from cancer registries in China, Hong Kong, South Korea, Taiwan, Singapore, and the United States. Age-period-cohort models were used to extrapolate longitudinal age-specific incidence rates for the 1920, 1944, and 1970 birth cohorts. Results: Cross-sectional age-specific incidence rates rose continuously until age 80 years among US white women, but plateaued or decreased after age 50 years among Asian women. In contrast, longitudinal age-specific rates were proportional (similar) among all Asian countries and the United States with incidence rates rising continuously until age 80 years. The extrapolated estimates for the most recent cohorts in some Asian countries actually showed later ages at onset than in the United States. Additionally, over successive birth cohorts, the incidence rate ratios (IRRs) for the longitudinal curves converged (narrowed) between Asian and US white women. Conclusions: Similar longitudinal age-specific incidence rates along with converging IRRs indicate that the age effects for invasive breast cancer are more similar among Asian and Western populations than might be expected from a solely cross-sectional analysis. Indeed, the Asian breast cancer rates in recent generations are even surpassing the historically high rates in the United States, highlighting an urgent need for efficient prevention and treatment strategies among Asian populations.Link_to_subscribed_fulltex

NF-κB p65 Subunit Is Modulated by Latent Transforming Growth Factor-β Binding Protein 2 (LTBP2) in Nasopharyngeal Carcinoma HONE1 and HK1 Cells.

NF-κB is a well-characterized transcription factor, widely known as a key player in tumor-derived inflammation and cancer development. Herein, we present the functional and molecular relevance of the canonical NF-κB p65 subunit in nasopharyngeal carcinoma (NPC). Loss- and gain-of-function approaches were utilized to reveal the functional characteristics of p65 in propagating tumor growth, tumor-associated angiogenesis, and epithelial-to-mesenchymal transition in NPC cells. Extracellular inflammatory stimuli are critical factors that trigger the NF-κB p65 signaling; hence, we investigated the components of the tumor microenvironment that might potentially influence the p65 signaling pathway. This led to the identification of an extracellular matrix (ECM) protein that was previously reported as a candidate tumor suppressor in NPC. Our studies on the Latent Transforming Growth Factor-β Binding Protein 2 (LTBP2) protein provides substantial evidence that it can modulate the p65 transcriptional activity. Re-expression of LTBP2 elicits tumor suppressive effects that parallel the inactivation of p65 in NPC cells. LTBP2 was able to reduce phosphorylation of p65 at Serine 536, inhibit nuclear localization of active phosphorylated p65, and impair the p65 DNA-binding ability. This results in a consequential down-regulation of p65-related gene expression. Therefore, the data suggest that the overall up-regulation of p65 expression and the loss of this candidate ECM tumor suppressor are milestone events contributing to NPC development

LTBP2 reduces angiogenesis <i>in vitro</i> and <i>in vivo</i>.

<p><b>(A)</b> Expression of secreted LTBP2 in conditioned media from HONE1 and HK1 LTBP2-transduced cells. Coomassie blue staining of total protein in conditioned media was used to indicate equal loading. <b>(B)</b> LTBP2-conditioned media from HONE1 and HK1 cells suppressed the tube formation ability of HUVEC cultures. Bar graph represents an average of triplicate experiments ± S.E.M. <b>(C)</b> Matrigel plug tumors were stained for CD34 to visualize the microvessels, as indicated by the black arrows. LTBP2-transduced cells displayed significantly fewer microvessels in matrigel plugs compared to VA cells, as indicated by the bar graphs. <b>(D)</b> Real-time PCR of HONE1 (top) and HK1 (bottom) LTBP2- and VA-transduced cells showed the down-regulation of angiogenesis-related genes with LTBP2 expression: <i>IL6</i>, <i>IL8</i>, <i>VEGF 165</i>, <i>VEGF 189</i>, <i>total VEGF</i>, <i>ANG</i>, <i>TSP1</i>, <i>uPAR</i>, <i>PDGB</i>, <i>RANTES</i>, and <i>MCP1</i>. The housekeeping gene, <i>GAPDH</i>, was used as an internal control. The above data were obtained from three independent experiments in duplicate and the (*) for all graphs indicate P-value < 0.05.</p

p65 signaling pathway regulates the protein expression of EGFR and EMT markers.

<p><b>(A)</b> Western blot analysis of p65shRNA- HONE1 cells showed reduced levels of phosphorylated p65 S536, total p65, and total IκBα compared to scramble control. IκBα-SR- HONE1 cells only showed a decreased amount of phosphorylated p65 S536, but did not affect the overall amount of total p65 when compared to pWPI-VA. Endogenous and exogenous IκBα are labeled as shown. The p84 was used as a loading control for scramble and p65 shRNA, pWPI-VA and IκBα-SR, separately. Protein expression of N-cadherin and total EGFR were all reduced in p65 shRNA and IκBα-SR HONE1 cells compared to scramble and pWPI-VA control. The (<b>^</b>) indicates the exogenous 3xHA-IκBα-SR. <b>(B)</b> Western blot analysis of p65 WT-overexpressing HONE1 cells showed increased acetylation at K310 and enhanced phosphorylation at S536 compared to VA cells. The p65 WT overexpression increases the protein levels of IκBα, snail, slug, twist, N-cadherin, and sox9, compared to VA cells. The p84 was used as a loading control. The (✚) indicates the exogenous RFP-p65 WT. The (★) indicates the acetylation band in the exogenously expressed RFP-p65 WT.</p