Nasopharyngeal carcinoma among the Bidayuh of Sarawak, Malaysia: History and risk factors

Mechanism of HOXA10 in nasopharyngeal carcinoma cell proliferation through the PTPRG-AS1/USP1 axis

Nasopharyngeal carcinoma (NPC) is an epithelial carcinoma arising from the nasopharyngeal mucosal lining. The present study sought to analyze the mechanism by which homeobox A10 (HOXA10) affects NPC cell proliferation. The expression levels of HOXA10/long noncoding RNA (lncRNA) PTPRG antisense RNA 1 (PTPRG-AS1)/ubiquitin-specific peptidase 1 (USP1) in NPC tissues and cells were determined. Cell proliferation was evaluated. The enrichment of HOXA10 on the PTPRG-AS1 promoter was determined. The binding of PTPRG-AS1, HuR, and USP1 to each other was analyzed via RNA immunoprecipitation. USP1 mRNA stability was determined after actinomycin D treatment. The role of the PTPRG-AS1/USP1 axis in NPC cell proliferation was analyzed in combined experiments. The role of HOXA10 in vivo was confirmed in xenograft tumor models. The results revealed that HOXA10 was overexpressed in NPC. HOXA10 downregulation reduced NPC cell proliferation. PTPRG-AS1 and USP1 were upregulated in NPC. HOXA10 bound to the PTPRG-AS1 promoter to increase PTPRG-AS1 expression, and the binding of PTPRG-AS1 to HuR increased USP1 expression. PTPRG-AS1 or USP1 overexpression attenuated the inhibitory effects of HOXA10 downregulation on NPC cell proliferation. HOXA10 downregulation inhibited in vivo NPC proliferation through the PTPRG-AS1/USP1 axis. In conclusion, HOXA10 facilitates NPC cell proliferation in vitro and in vivo through the PTPRG-AS1/USP1 axis.

Nasopharyngeal carcinoma in Sarawak : a 10-year review and update

AIM

Nasopharyngeal carcinoma (NPC) is prevalent in certain regions, particularly Southeast Asia and Southern China. In Malaysia, it is notably frequent among the Bidayuh community. This study presents a comprehensive review of NPC cases diagnosed and treated at Sarawak General Hospital from 2010 to 2020.

METHOD

A retrospective data collection was conducted using the clinical records of patients who were histopathologically diagnosed with NPC at the Otolaryngology-Head & Neck Clinic and the Radiotherapy & Oncology Clinic at Sarawak General Hospital.

RESULT

The study comprised a total of 892 patients from 2010 to 2020. Males outnumbered females 3-to-1, with a mean age of 51 years (standard deviation: 13.9). The largest groups of patients were the Iban (34%) and the Bidayuh (21%), followed by the Chinese (19%) and the Malay (15%). The Bidayuh had the highest incidence rate with 81 cases per 100,000. Only 10% of the study population had a family history of NPC. The most common presentation was a neck lump (64.5%). Distant metastasis was discovered in 20% of patients. 82% of the cases were stage 3 or 4 at the time of presentation. The histological types of the 892 cases were mainly undifferentiated carcinoma (73%). Eighty-six patients developed recurrence, with 83% experiencing local recurrence, 10% developing distant metastasis, and 7% developing regional recurrence. Treatment for recurrence included nasopharyngectomy, neck dissection, and chemotherapy.

CONCLUSION

The study highlights a significant incidence of NPC among the Bidayuh. Emphasis on screening and early detection is crucial for better outcomes, with lifelong follow-up recommended.

Epidemiology of nasopharyngeal carcinoma: current insights and future outlook

Nasopharyngeal carcinoma (NPC) is characterised by its remarkable geographical and ethnic distribution. The interplay between genetic susceptibility, environmental exposures, and Epstein-Barr virus (EBV) infections is indicated in the development of NPC. Exposure to tobacco smoking, dietary factors, and inhalants has been associated with the risk of NPC. Genetic association studies have revealed NPC-associated susceptibility loci, including genes involved in immune responses, xenobiotic metabolism, genome maintenance, and cell cycle regulation. EBV exposure timing and strain variation might play a role in its carcinogenicity, although further investigations are required. Other factors including medical history and oral hygiene have been implicated in NPC. Prevention strategies, including primary prevention and secondary prevention through early detection, are vital in reducing mortality and morbidity of NPC. The current review discusses the global and regional distribution of NPC incidences, the risk factors associated with NPC, and the public health implications of these insights. Future investigations should consider international, large-scale prospective studies to elucidate the mechanisms underlying NPC pathogenesis and develop individualized interventions for NPC.

Establishment and Characterization of an Epstein-Barr Virus-positive Cell Line from a Non-keratinizing Differentiated Primary Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC), a cancer that is etiologically associated with the Epstein-Barr virus (EBV), is endemic in Southern China and Southeast Asia. The scarcity of representative NPC cell lines owing to the frequent loss of EBV episomes following prolonged propagation and compromised authenticity of previous models underscores the critical need for new EBV-positive NPC models. Herein, we describe the establishment of a new EBV-positive NPC cell line, designated NPC268 from a primary non-keratinizing, differentiated NPC tissue. NPC268 can undergo productive lytic reactivation of EBV and is highly tumorigenic in immunodeficient mice. Whole-genome sequencing revealed close similarities with the tissue of origin, including large chromosomal rearrangements, while whole-genome bisulfite sequencing and RNA sequencing demonstrated a hypomethylated genome and enrichment in immune-related pathways, respectively. Drug screening of NPC268 together with six other NPC cell lines using 339 compounds, representing the largest high-throughput drug testing in NPC, revealed biomarkers associated with specific drug classes. NPC268 represents the first and only available EBV-positive non-keratinizing differentiated NPC model, and extensive genomic, methylomic, transcriptomic, and drug response data should facilitate research in EBV and NPC, where current models are limited.

SIGNIFICANCE

NPC268 is the first and only EBV-positive cell line derived from a primary non-keratinizing, differentiated nasopharyngeal carcinoma, an understudied but important subtype in Southeast Asian countries. This model adds to the limited number of authentic EBV-positive lines globally that will facilitate mechanistic studies and drug development for NPC.

Role of long non-coding RNA in chemoradiotherapy resistance of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor originating from the nasopharyngeal epithelial cells. Common treatment methods for NPC include radiotherapy, chemotherapy, and surgical intervention. Despite these approaches, the prognosis for NPC remains poor due to treatment resistance and recurrence. Hence, there is a crucial need for more comprehensive research into the mechanisms underlying treatment resistance in NPC. Long non coding RNAs (LncRNAs) are elongated RNA molecules that do not encode proteins. They paly significant roles in various biological processes within tumors, such as chemotherapy resistance, radiation resistance, and tumor recurrence. Recent studies have increasingly unveiled the mechanisms through which LncRNAs contribute to treatment resistance in NPC. Consequently, LncRNAs hold promise as potential biomarkers and therapeutic targets for diagnosing NPC. This review provides an overview of the role of LncRNAs in NPC treatment resistance and explores their potential as therapeutic targets for managing NPC.

Epidemiology of Nasopharyngeal Carcinoma in Sarawak, East Malaysia

OBJECTIVES

This analysis provides an epidemiological update for nasopharyngeal carcinomas the state of Sarawak and an analysis of the trend over a 20 years period.

METHOD

Data between 1996 to 2015 from a population-based cancer registry in Sarawak Malaysia was analyzed. Crude incidence rates and age-standardized rates (ASR) were calculated and compared between ethnic groups and locations (administrative division) and Joinpoint regression analysis was done to analyze trends.

RESULT

A total of 3643 cases of NPC were recorded with male to female ratio of 2.5:1. Annualised age-standardized incidence rates able 2) for men is 13.2 cases per 100,000 population (95% CI: 12.6, 13.7) and for women is 5.3 cases per 100,000 population (95% CI: 5.0, 5.6). The highest incidence rates were reported among the Bidayuh population and it ranks among the highest in the world. Trend analysis noted an overall reduction of cases, with a significant decrease between 1996 and 2003 (annual percentage reduction of incidence by 3.9%). Analysis of individual ethnic groups also shows a general reduction with exception of Iban males showing an average 5.48 per cent case increase between 2009 to 2015, though not statistically significant.

CONCLUSION

Comparing the incidences with other registries, the Bidayuh population in Sarawak remained among the highest in the world and warrants close attention for early screening and prevention strategies.

The epidemiology of haematological cancers in Sarawak, Malaysia (1996 to 2015)

BACKGROUND

Published epidemiological studies of haematological cancers are few. Hereby we present a 20-year epidemiological data of haematological cancers in Sarawak from a population-based cancer registry.

METHODS

Haematological cancer cases with ICD-10 coded C81-C96 and ICD-O coded /3 diagnosed from 1996 to 2015 were retrieved from Sarawak Cancer Registry. Adult was defined as those 15 years and above. Incidence rate (IR) was calculated based on yearly Sarawak citizen population stratified to age, gender, and ethnic groups. Age-standardised IR (ASR) was calculated using Segi World Standard Population.

RESULTS

A total of 3,947 cases were retrieved and analysed. ASR was 10 and male predominance (IR ratio 1.32, 95%CI 1.24,1.41). Haematological cancers generally had a U-shaped distribution with lowest IR at age 10-14 years and exponential increment from age 40 years onwards, except acute lymphoblastic leukaemia (ALL) with highest IR in paediatric 2.8 versus adult 0.5. There was a significant difference in ethnic and specific categories of haematological cancers, of which, in general, Bidayuh (IR ratio 1.13, 95%CI 1.00, 1.27) and Melanau (IR ratio 0.54, 95%CI 0.45, 0.65) had the highest and lowest ethnic-specific IR, respectively, in comparison to Malay. The ASR (non-Hodgkin lymphoma, acute myeloid leukaemia, ALL, chronic myeloid leukaemia, and plasma cell neoplasm) showed a decreasing trend over the 20 years, -2.09 in general, while Hodgkin lymphoma showed an increasing trend of + 2.80. There was crude rate difference between the 11 administrative divisions of Sarawak.

CONCLUSIONS

This study provided the IR and ASR of haematological cancers in Sarawak for comparison to other regions of the world. Ethnic diversity in Sarawak resulted in significant differences in IR and ASR.

Development and validation of the health belief model questionnaire to promote smoking cessation for nasopharyngeal cancer prevention: a cross-sectional study

OBJECTIVE

Lifestyle-induced nasopharyngeal carcinoma is a serious but preventable risk factor. This study serves to develop and validate a questionnaire that aims to predict the health behavioural intention on smoking cessation in Sarawak, Malaysia using the Health Belief Model (HBM).

DESIGN

A cross-sectional study.

SETTING

Urban and suburban areas in Sarawak, Malaysia.

PARTICIPANTS

The preliminary items of the instrument were developed after extensive literature review. The instrument was translated into the Malay language using the forward-backwards method before commencing with the content validity by a panel of 10 experts. Face validity was done both quantitatively and qualitatively by 10 smokers. The construct validity of the instrument was evaluated through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). A total of 100 smokers participated in phase 1 for EFA, while 171 smokers participated in phase 2 for CFA. Internal consistency was measured using Cronbach's alpha coefficients to evaluate the reliability.

RESULTS

In the exploratory stage, the factor loading of each item remained within the acceptable threshold. The final revised CFA yielded appropriate fit of the seven-factor model with the following model fit indices: χ²=641.705; df=500; p<0.001; comparative fit index=0.953; Tucker-Lewis Index=0.948; root mean square error of approximation=0.041. Satisfactory convergent validity and divergent validity were shown, with the exception of one pairwise construct. The internal reliability of these scales was above the desirable threshold, with Cronbach's alpha coefficients ranging from 0.705 to 0.864 and 0.838 to 0.889 in phases 1 and 2, respectively.

CONCLUSIONS

The study substantiated the instrument to be valid and reliable for predicting smokers' health behavioural intention to reduce cancer risk. The instrument is made up of 34 items, categorised into two sections, six HBM constructs and health behavioural intention. The instrument can be utilised for other smoking cessation-related cancers in different at-risk populations.

Epidemiology of indigenous Plasmodium knowlesi infection in Sarawak, 2011-2019

OBJECTIVES

To characterize the state-wide epidemiology of indigenous knowlesi malaria in Sarawak from 2011-2019.

METHODS

Longitudinal retrospective study based on Sarawak knowlesi malaria surveillance data recorded 2011-2019. Only indigenous cases were included and information extracted for analysis comprised age, sex, occupation, ethnicity, case severity, hospital admission, and parasite density.

RESULTS

Over the 9 years 8473 indigenous knowlesi malaria cases were recorded. Age group 40 to 49 years, males, plantation workers, and Iban communities recorded the highest percentage of cases in each demographic variable. Most of the cases were uncomplicated (85.9%) and 89.5% of the total cases were reported with ≤20,000 parasites/μL of blood. Age group and ethnic group are associated with severity of knowlesi malaria in Sarawak. Multivariable logistic regression indicated that the age group 60+ years had the highest odds of developing severe knowlesi malaria compared to other age groups (AOR 2.48; 95% CI 1.22, 5.02; p=0.012). Bidayuh patients were more likely to develop severe knowlesi malaria than Ibans, the largest ethnic group among knowlesi malaria patients (AOR 1.97; 95% CI 1.31, 2.97; p=0.001).

CONCLUSIONS

Identification of risk groups is important for the implementation of prevention programs and treatments targeting at specific group to combat knowlesi malaria effectively.

Nasopharyngeal Carcinoma and Its Microenvironment: Past, Current, and Future Perspectives

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy that raises public health concerns in endemic countries. Despite breakthroughs in therapeutic strategies, late diagnosis and drug resistance often lead to unsatisfactory clinical outcomes in NPC patients. The tumor microenvironment (TME) is a complex niche consisting of tumor-associated cells, such as fibroblasts, endothelial cells, leukocytes, that influences tumor initiation, progression, invasion, and metastasis. Cells in the TME communicate through various mechanisms, of note, exosomes, ligand-receptor interactions, cytokines and chemokines are active players in the construction of TME, characterized by an abundance of immune infiltrates with suppressed immune activities. The NPC microenvironment serves as a target-rich niche for the discovery of potential promising predictive or diagnostic biomarkers and the development of therapeutic strategies. Thus, huge efforts have been made to exploit the role of the NPC microenvironment. The whole picture of the NPC microenvironment remains to be portrayed to understand the mechanisms underlying tumor biology and implement research into clinical practice. The current review discusses the recent insights into the role of TME in the development and progression of NPC which results in different clinical outcomes of patients. Clinical interventions with the use of TME components as potential biomarkers or therapeutic targets, their challenges, and future perspectives will be introduced. This review anticipates to provide insights to the researchers for future preclinical, translational and clinical research on the NPC microenvironment.