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  1. Fulltext Potentially malignant disorders of the oral cavity: current practice and future directions in the clinic and laboratory
    Dionne KR, Warnakulasuriya S, Zain RB, Cheong SC
    Int J Cancer, 2015 Feb 1;136(3):503-15.
    PMID: 24482244 DOI: 10.1002/ijc.28754
    Despite commendable progress in the prevention, detection, and treatment of a wide variety of solid tumor types, oral squamous cell carcinoma (OSCC) remains a significant health burden across the globe. OSCC carcinogenesis involves accumulation of genetic alterations that coincide with the multistep malignant transformation of normal oral epithelium. OSCC is often first diagnosed at late stages of the disease (advanced regional disease and/or metastasis). Delayed diagnosis precludes successful treatment and favorable outcomes. In clinical practice, opportunities exist to identify patients with oral potentially malignant disorders (OPMDs), which precede the development of cancer. This review addresses the current status of laboratory and clinical research on OPMDs, with emphasis on leukoplakia and erythroplakia. OSF is also presented, though there is a paucity of published studies on this disorder. We focus on findings that could translate into earlier diagnosis and more efficacious treatment of those lesions with significant malignant potential. We explore how markers of OPMD malignant transformation might be implemented into current diagnostic practice to help clinicians objectively stratify patients into treatment/follow-up groups according to relative risk. We provide an overview of recently concluded and ongoing OPMD chemoprevention trials. We describe laboratory OPMD models that can be used to not only to reveal the genetic and molecular intricacies of oral cancer but also to develop novel screening methods and therapeutic approaches. Finally, we call for targeted screening programs of at-risk populations in order to facilitate diagnosis and treatment of OPMD and early OSCC.
  2. Human telomerase reverse transcriptase expression in oral carcinogenesis--a preliminary report
    Kumar SK, Zain RB, Ismail SM, Cheong SC
    J Exp Clin Cancer Res, 2005 Dec;24(4):639-46.
    PMID: 16471328
    Human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase, is strongly associated with telomerase activity implicated in cellular immortalization and tumorigenesis. In situ detection of hTERT will aid in determining the localization of telomerase positive cells. The aim of this study was to detect hTERT protein expression in multistep oral carcinogenesis using paraffin embedded tissue samples, and to study the relationship of hTERT expression with different histological stages in oral carcinogenesis. Normal (n = 4), hyperplastic (n = 4), dysplastic (n = 4) and neoplastic (n = 10) oral epithelia representing different histological stages in oral carcinogenesis were included in the study. hTERT protein detection was done by immunohistochemistry (IHC) technique. Nuclear staining intensities were noted and the hTERT-labelling index was determined. Dysplastic and neoplastic oral epithelia showed an increased percentage of hTERT positive cells (Grade 4: > 50% positive staining nuclei) with intense staining in the basal, parabasal and superficial layers of the epithelia, unlike normal oral mucosa which showed intense staining only in the basal and parabasal cell layers, which are the normal proliferative progenitor compartments. hTERT protein expression was elevated with the corresponding advancement of the histological stages of oral carcinogenesis, from normal to hyperplasia to dysplasia to carcinoma. There seems to be an upregulation of hTERT protein expression during the progression of oral cancer, therefore, this may indicate the feasibility of IHC detection of hTERT protein in oral carcinogenesis as a potential diagnostic or prognostic marker.
  3. Translational genomics and recent advances in oral squamous cell carcinoma
    Chai AWY, Lim KP, Cheong SC
    Semin Cancer Biol, 2020 04;61:71-83.
    PMID: 31542510 DOI: 10.1016/j.semcancer.2019.09.011
    Oral squamous cell carcinomas (OSCC) are a heterogeneous group of cancers arising from the mucosal lining of the oral cavity. A majority of these cancers are associated with lifestyle risk habits including smoking, excessive alcohol consumption and betel quid chewing. Cetuximab, targeting the epidermal growth factor receptor was approved for the treatment of OSCC in 2006, and remains the only molecular targeted therapy available for OSCC. Here, we reviewed the current findings from genomic analyses of OSCC and discuss how these studies inform on the biological mechanisms underlying OSCC. Exome sequencing revealed that the significantly mutated genes are mainly tumour suppressors. Mutations in FAT1, CASP8, CDKN2A, and NOTCH1 are more frequently found in OSCC when compared to non-OSCC head and neck cancers and other squamous cell carcinomas, and HRAS and PIK3CA are the only significantly mutated oncogenes. The distribution of these mutations also differs in populations with distinct risk habits. Gene expression-based molecular classification showed that OSCC can be divided into distinct subtypes and these have a preferential response to different types of therapies, suggesting that these classifications could have clinical implications. More recently, with the approval of checkpoint inhibitors for the treatment of cancers including OSCC, genomics studies also dissected the genetic signatures of the immune compartment to delineate immune-active and -exhausted subtypes that could inform on the immune status of OSCC patients and guide the development of novel therapies to improve response to immunotherapy. Taken together, genomics studies are informing on the biology of both the epithelial and stromal compartments underlying OSCC development, and we discuss the opportunities and challenges in using these to derive clinical benefit for OSCC patients.
  4. Targeting the genetic landscape of oral potentially malignant disorders has the potential as a preventative strategy in oral cancer
    Prime SS, Cirillo N, Cheong SC, Prime MS, Parkinson EK
    Cancer Lett, 2021 10 10;518:102-114.
    PMID: 34139286 DOI: 10.1016/j.canlet.2021.05.025
    This study reviews the molecular landscape of oral potentially malignant disorders (OPMD). We examine the impact of tumour heterogeneity, the spectrum of driver mutations (TP53, CDKN2A, TERT, NOTCH1, AJUBA, PIK3CA, CASP8) and gene transcription on tumour progression. We comment on how some of these mutations impact cellular senescence, field cancerization and cancer stem cells. We propose that OPMD can be monitored more closely and more dynamically through the use of liquid biopsies using an appropriate biomarker of transformation. We describe new gene interactions through the use of a systems biology approach and we highlight some of the first studies to identify functional genes using CRISPR-Cas9 technology. We believe that this information has translational implications for the use of re-purposed existing drugs and/or new drug development. Further, we argue that the use of digital technology encompassing clinical and laboratory-based data will create relevant datasets for machine learning/artificial intelligence. We believe that therapeutic intervention at an early molecular premalignant stage should be an important preventative strategy to inhibit the development of oral squamous cell carcinoma and that this approach is applicable to other aerodigestive tract cancers.
  5. Fulltext Uncovering drug repurposing candidates for head and neck cancers: insights from systematic pharmacogenomics data analysis
    Chai AWY, Tan AC, Cheong SC
    Sci Rep, 2021 12 14;11(1):23933.
    PMID: 34907286 DOI: 10.1038/s41598-021-03418-1
    Effective treatment options for head and neck squamous cell carcinoma (HNSCC) are currently lacking. We exploited the drug response and genomic data of the 28 HNSCC cell lines, screened with 4,518 compounds, from the PRISM repurposing dataset to uncover repurposing drug candidates for HNSCC. A total of 886 active compounds, comprising of 418 targeted cancer, 404 non-oncology, and 64 chemotherapy compounds were identified for HNSCC. Top classes of mechanism of action amongst targeted cancer compounds included PI3K/AKT/MTOR, EGFR, and HDAC inhibitors. We have shortlisted 36 compounds with enriched killing activities for repurposing in HNSCC. The integrative analysis confirmed that the average expression of EGFR ligands (AREG, EREG, HBEGF, TGFA, and EPGN) is associated with osimertinib sensitivity. Novel putative biomarkers of response including those involved in immune signalling and cell cycle were found to be associated with sensitivity and resistance to MEK inhibitors respectively. We have also developed an RShiny webpage facilitating interactive visualization to fuel further hypothesis generation for drug repurposing in HNSCC. Our study provides a rich reference database of HNSCC drug sensitivity profiles, affording an opportunity to explore potential biomarkers of response in prioritized drug candidates. Our approach could also reveal insights for drug repurposing in other cancers.
  6. Dentists' perception of the role they play in early detection of oral cancer
    Saleh A, Kong YH, Vengu N, Badrudeen H, Zain RB, Cheong SC
    Asian Pac J Cancer Prev, 2014;15(1):229-37.
    PMID: 24528031
    BACKGROUND: Dentists are typically the first professionals who are approached to treat ailments within the oral cavity. Therefore they should be well-equipped in detecting suspicious lesions during routine clinical practice. This study determined the levels of knowledge on early signs and risk factors associated with oral cancer and identified which factors influenced dentist participation in prevention and early detection of oral cancer.

    MATERIALS AND METHODS: A survey on dentists' knowledge and their practices in prevention and early detection of oral cancer was conducted using a 26-item self-administered questionnaire.

    RESULTS AND CONCLUSIONS: A response rate of 41.7% was achieved. The level of knowledge on early signs and risk habits associated with oral cancer was high and the majority reported to have conducted opportunistic screening and advised patients on risk habit cessation. Factors that influenced the dentist in practising prevention and early detection of oral cancer were continuous education on oral cancer, age, nature of practice and recent graduation. Notably, dentists were receptive to further training in the area of oral cancer detection and cessation of risk habits. Taken together, the study demonstrated that the dental clinic is a good avenue to conduct programs on opportunistic screening, and continuous education in these areas is necessary to adequately equip dentists in running these programs. Further, this study also highlighted knowledge deficits and practice shortcomings which will help in planning and developing programs that further encourage better participation of dentists in prevention and early detection of oral cancer.

  7. Fulltext Comparative proteomics analysis of oral cancer cell lines: identification of cancer associated proteins
    Karsani SA, Saihen NA, Zain RB, Cheong SC, Abdul Rahman M
    Proteome Sci, 2014;12(1):3.
    PMID: 24422745 DOI: 10.1186/1477-5956-12-3
    A limiting factor in performing proteomics analysis on cancerous cells is the difficulty in obtaining sufficient amounts of starting material. Cell lines can be used as a simplified model system for studying changes that accompany tumorigenesis. This study used two-dimensional gel electrophoresis (2DE) to compare the whole cell proteome of oral cancer cell lines vs normal cells in an attempt to identify cancer associated proteins.
  8. Oral cancer secretome: identification of cancer-associated proteins
    Chang HY, Hor SY, Lim KP, Zain RB, Cheong SC, Rahman MA, et al.
    Electrophoresis, 2013 Aug;34(15):2199-208.
    PMID: 23712713 DOI: 10.1002/elps.201300126
    This study aims to identify cancer-associated proteins in the secretome of oral cancer cell lines. We have successfully established four primary cell cultures of normal cells with a limited lifespan without human telomerase reverse transcriptase (hTERT) immortalization. The secretome of these primary cell cultures were compared with that of oral cancer cell lines using 2DE. Thirty five protein spots were found to have changed in abundance. Unambiguous identification of these proteins was achieved by MALDI TOF/TOF. In silico analysis predicted that 24 of these proteins were secreted via classical or nonclassical mechanisms. The mRNA expression of six genes was found to correlate with the corresponding protein abundance. Ingenuity Pathway Analysis (IPA) core analysis revealed that the identified proteins were relevant in, and related to, cancer development with likely involvements in tumor growth, metastasis, hyperproliferation, tumorigenesis, neoplasia, hyperplasia, and cell transformation. In conclusion, we have demonstrated that a comparative study of the secretome of cancer versus normal cell lines can be used to identify cancer-associated proteins.
  9. Combined effects of isothiocyanate intake, glutathione S-transferase polymorphisms and risk habits for age of oral squamous cell carcinoma development
    Karen-Ng LP, Marhazlinda J, Rahman ZA, Yang YH, Jalil N, Cheong SC, et al.
    Asian Pac J Cancer Prev, 2011;12(5):1161-6.
    PMID: 21875259
    Dietary isothiocyanates (ITCs) found in cruciferous vegetables (Brassica spp.) has been reported to reduce cancer risk by inducing phase II conjugating enzymes, in particular glutathione S-transferases (GSTs). This case-control study was aimed at determining associations between dietary ITCs, GSTs polymorphisms and risk habits (cigarette smoking, alcohol drinking and betel-quid chewing) with oral cancer in 115 cases and 116 controls. Information on dietary ITC intake from cruciferous vegetables was collected via a semi-quantitative food frequency questionnaire (FFQ). Peripheral blood lymphocytes were obtained for genotyping of GSTM1, GSTT1 and GSTP1 using PCR multiplex and PCR-RFLP. Chi-square and logistic regression were performed to determine the association of ITC and GSTs polymorphism and risk of oral cancer. When dietary ITC was categorized into high (greater than/equal to median) and low (less than median) intake, there was no significant difference between cases and control group. Logistic regression yielding odd ratios resulted in no significant association between dietary ITC intake, GSTM1, GSTT1 or GSTP1 genotypes with oral cancer risk overall. However, GSTP1 wild-type genotype was associated with later disease onset in women above 55 years of age (p= 0.017). Among the men above 45 years of age, there was clinical significant difference of 17 years in the age of onset of oral cancer between GSTP1 wild-type + low ITC intake and GSTP1 polymorphism + high ITC intake (p= 0.001). Similar conditions were also seen among men above 45 years of age with risk habits like drinking and chewing as the earlier disease onset associated with GSTP1 polymorphism and high ITC intake (p< 0.001). This study suggests that combination effects between dietary ITCs, GSTP1 polymorphism and risk habits may be associated with the risk of oral cancer and modulate the age of disease onset.
  10. HPV infection and the alterations of the pRB pathway in oral carcinogenesis
    Lim KP, Hamid S, Lau SH, Teo SH, Cheong SC
    Oncol Rep, 2007 Jun;17(6):1321-6.
    PMID: 17487385 DOI: 10.3892/or.17.6.1321
    Inactivation of the retinoblastoma (pRB) pathway is a common event in oral squamous cell carcinoma particularly through the aberrant expression of the components within this pathway. This study examines the alterations of molecules within the pRB pathway by looking at the presence of homozygous deletions in p16(INK4A) and the expression patterns of pRB, cyclin D1 and CDK4, as well as the presence of human papillomavirus (HPV) in our samples. In our study, 5/20 samples demonstrated deletions of p16(INK4A) exon 1alpha. pRB overexpression was found in 20/20 samples, the expression was mainly observed in all layers of the epithelia, particularly in the basal layer where cells are actively dividing and aberrant pRB expression was found in 12/20 samples. Cyclin D1 and CDK4 overexpression was detected in 6/20 and 2/20 samples respectively in comparison to hyperplasias where both proteins were either not expressed or expressed at minimal levels (<10%). Strikingly, HPV was found to be present in all of our samples, suggesting that HPV plays a significant role in driving oral carcinogenesis. Notably, 17/20 of our samples showed more than one alteration in the pRB pathway, however, we did not find any significant relationship between the presence of HPV, homozygous deletion of p16(INK4A) and overexpression of pRB, cyclin D1 and CDK4. Collectively, this data demonstrates that alterations in the pRB pathway are a common event and involve the aberration of more than one molecule within the pathway. Furthermore, the involvement of HPV in all our samples suggests that HPV infection may play an important role in oral carcinogenesis.
  11. Alterations of the p14ARF-p53-MDM2 pathway in oral squamous cell carcinoma: MDM2 overexpression is a common event
    Lim KP, Sharifah H, Lau SH, Teo SH, Cheong SC
    Oncol Rep, 2005 Oct;14(4):963-8.
    PMID: 16142358 DOI: 10.3892/or.14.4.963
    The majority of global incidences of oral cancer occur in Asia, and the aetiology of oral cancer is different in Asia as it is in the West. However, whereas there is a growing understanding of the molecular mechanisms of oral cancer progression in the West, there is little progress in this understanding in Asia. In particular, the role of the p53 pathway in modulating cancer progression in Asian oral cancer remains unclear. In this study, we micro-dissected and analysed 20 well-differentiated oral squamous cell carcinoma specimens for alterations in the p53 pathway. We found that 6/20 samples contained mutations in the p53 gene which occurred in three hotspots, at codon 203, 218 and 296. Furthermore, 6/20 samples had a homozygous deletion of p14ARF, but notably p14ARF deletion and p53 mutation events were often independent and mutually exclusive. Strikingly, MDM2 was upregulated in 20/20 samples, but not in 3/3 normal tissue specimens. Taken together, these data suggest that inactivation of the p53 pathway is a frequent event in oral squamous cell carcinoma, which occurs by an aberration in one of a number of players in the p53 pathway.
  12. Fulltext Provider cost of treating oral potentially malignant disorders and oral cancer in Malaysian public hospitals
    Raman S, Shafie AA, Abraham MT, Shim CK, Maling TH, Rajendran S, et al.
    PLoS One, 2021;16(5):e0251760.
    PMID: 33984051 DOI: 10.1371/journal.pone.0251760
    Oral cancer has been recognized as a significant challenge to healthcare. In Malaysia, numerous patients frequently present with later stages of cancers to the highly subsidized public healthcare facilities. Such a trend contributes to a substantial social and economic burden. This study aims to determine the cost of treating oral potentially malignant disorders (OPMD) and oral cancer from a public healthcare provider's perspective. Medical records from two tertiary public hospitals were systematically abstracted to identify events and resources consumed retrospectively from August 2019 to January 2020. The cost accrued was used to estimate annual initial and maintenance costs via two different methods- inverse probability weighting (IPW) and unweighted average. A total of 86 OPMD and 148 oral cancer cases were included. The initial phase mean unadjusted cost was USD 2,861 (SD = 2,548) in OPMD and USD 38,762 (SD = 12,770) for the treatment of cancer. Further annual estimate of initial phase cost based on IPW method for OPMD, early and late-stage cancer was USD 3,561 (SD = 4,154), USD 32,530 (SD = 12,658) and USD 44,304 (SD = 16,240) respectively. Overall cost of late-stage cancer was significantly higher than early-stage by USD 11,740; 95% CI [6,853 to 16,695]; p< 0.001. Higher surgical care and personnel cost predominantly contributed to the larger expenditure. In contrast, no significant difference was identified between both cancer stages in the maintenance phase, USD 700; 95% CI [-1,142 to 2,541]; p = 0.457. A crude comparison of IPW estimate with unweighted average displayed a significant difference in the initial phase, with the latter being continuously higher across all groups. IPW method was shown to be able to use data more efficiently by adjusting cost according to survival and follow-up. While cost is not a primary consideration in treatment recommendations, our analysis demonstrates the potential economic benefit of investing in preventive medicine and early detection.
  13. Oral cancer screening in private dental practices in a developing country: opportunities and challenges
    Saleh A, Kong YH, Haron N, Aripin SF, Vadiveloo M, Hussaini H, et al.
    Community Dent Oral Epidemiol, 2017 04;45(2):112-119.
    PMID: 27805279 DOI: 10.1111/cdoe.12266
    OBJECTIVES: Private dental practitioners constitute approximately 40% of all registered dentists in Malaysia, and this group affords an avenue for prevention and early detection of oral cancer. However, such activities are still limited. This study investigated the feasibility of incorporating opportunistic screening of oral cancer in the private dental setting.

    METHODS: Dentists were recruited through two main dental associations in Malaysia and attended a 1-day training session on recognizing abnormalities within the oral cavity. Following the training, the dentists conducted screening and provided risk habits cessation advice at their respective clinics for 6 months. The impact of the program was evaluated by determining the number of patients who were screened and/or provided with risk habits cessation advice.

    RESULTS: Twenty-six dentists took part in the program and conducted opportunistic screening on a total of 2603 individuals. On average, they screened about 23.0% of their patients and 5.1% were given risk habits cessation advice. Notably, dentists who had lower patient load were more likely to conduct opportunistic screening.

    CONCLUSIONS: While the participating private dentists state that they have a role in performing opportunistic screening and providing risk habits cessation advice, these activities are still not a priority area in the private clinics, strongly suggesting that strategies to motivate dentists in this setting are urgently needed.

  14. World Workshop on Oral Medicine VII: Functional pathways involving differentially expressed lncRNAs in oral squamous cell carcinoma
    Pentenero M, Bowers L, Jayasinghe R, Cheong SC, Farah CS, Kerr AR, et al.
    Oral Dis, 2019 Jun;25 Suppl 1:79-87.
    PMID: 31140691 DOI: 10.1111/odi.13051
    Long non-coding RNAs (lncRNA) modulate gene expression at the epigenetic, transcriptional and post-transcriptional levels and are involved in tumorigenesis. They can form complex secondary and tertiary structures and have been shown to act as precursors, enhancers, reservoirs and decoys in the complex endogenous RNA network. They were first reported in relation to oral squamous cell carcinoma (OSCC) in 2013. Here, we summarise the functional roles and pathways of the most commonly studied lncRNAs in OSCC. Existing research demonstrates the involvement of lncRNA within pivotal pathways leading to the development and spread of OSCC, including interactions with key cancer-associated microRNAs such as miR-21. The number of studies on lncRNA and OSCC remains limited in this new field. As evidence grows, the tissue-specific expression patterns of lncRNAs should further advance our understanding of the altered regulatory networks in OSCC and possibly reveal new biomarkers and therapeutic targets.
  15. The establishment of the Asia-Pacific Oral Cancer Network-Inaugural stakeholders' Meeting
    Syed Mohd Sobri SNS, Kanapathy J, Liew CS, Cheong SC
    Oral Dis, 2020 Jul;26(5):1094-1097.
    PMID: 32145142 DOI: 10.1111/odi.13320
    The majority of oral cancer cases occur in Asia and the incidence is expected to continue to rise. Oral cancer is amenable to early detection through visual oral examination yet in many Asian countries, the disease presents at a late stage. The barriers to early detection are similar across the Asia-Pacific countries therefore, strategies to address these could be more effective if there were concerted efforts and joint resources amongst the countries. To facilitate better engagement and collaboration between stakeholders in oral cancer detection and management, the Asia-Pacific Oral Cancer Network (APOCNET) was established and the inaugural meeting was held in Kuala Lumpur on the 13th to 15th of September 2019. In this meeting, we identified the challenges faced in the early detection and management of oral cancer amongst the stakeholder countries, showcased the successful oral cancer programs in the region and identified strategic areas for collaboration. For this, notable international speakers and those from local universities and the Ministry of Health Malaysia were invited to share their experiences. The lessons learned from our neighbouring countries could lead to the implementation of similar programs that could help reduce the oral cancer burden in the region.
  16. Fulltext World Workshop on Oral Medicine VII: Clinical evidence of differential expression of lncRNAs in oral squamous cell carcinoma: A scoping review
    Pentenero M, Bowers LM, Jayasinghe R, Yap T, Cheong SC, Kerr AR, et al.
    Oral Dis, 2019 Jun;25 Suppl 1(Suppl 1):88-101.
    PMID: 31140697 DOI: 10.1111/odi.13076
    BACKGROUND: Long non-coding RNAs (lncRNAs) have important roles in regulating gene expression pertaining to cell proliferation, survival, migration and genomic stability. Dysregulated expression of lncRNAs is implicated in cancer initiation, progression and metastasis.

    OBJECTIVES: To explore, map and summarize the extent of evidence from clinical studies investigating the differential expression of lncRNAs in oral/tongue squamous cell carcinoma.

    METHODS: PubMed, Scopus and Web of Science were used as search engines. Clinical, full-length, English language studies were included. PRISMA-ScR protocol was used to evaluate and present results. The present scoping review summarizes relationships of the differential expression of lncRNAs with the presence of tumour and with clinicopathological features including survival.

    RESULTS: Almost half of the investigated transcripts have been explored in more than one study, yet not always with consistent results. The collected data were also compared to the limited studies investigating oral epithelial dysplasia. Data are not easily comparable, first because of different methods used to define what differential expression is, and second because only a limited number of studies performed multivariate analyses to identify clinicopathological features associated with the differentially expressed lncRNAs.

    CONCLUSIONS: Standard methods and more appropriate data analyses are needed in order to achieve reliable results from future studies.

  17. Teledentistry may help in detecting oral cancers in current GP and dentist shortages
    Bradley P, Deane J, O'Hara J, Kennedy M, Carrard VC, Cheong SC, et al.
    BMJ, 2024 Mar 01;384:q512.
    PMID: 38428988 DOI: 10.1136/bmj.q512
  18. Fulltext In Vitro Growth of Human Keratinocytes and Oral Cancer Cells into Microtissues: An Aerosol-Based Microencapsulation Technique
    Leong WY, Soon CF, Wong SC, Tee KS, Cheong SC, Gan SH, et al.
    Bioengineering (Basel), 2017 May 14;4(2).
    PMID: 28952522 DOI: 10.3390/bioengineering4020043
    Cells encapsulation is a micro-technology widely applied in cell and tissue research, tissue transplantation, and regenerative medicine. In this paper, we proposed a growth of microtissue model for the human keratinocytes (HaCaT) cell line and an oral squamous cell carcinoma (OSCC) cell line (ORL-48) based on a simple aerosol microencapsulation technique. At an extrusion rate of 20 μL/min and air flow rate of 0.3 L/min programmed in the aerosol system, HaCaT and ORL-48 cells in alginate microcapsules were encapsulated in microcapsules with a diameter ranging from 200 to 300 μm. Both cell lines were successfully grown into microtissues in the microcapsules of alginate within 16 days of culture. The microtissues were characterized by using a live/dead cell viability assay, field emission-scanning electron microscopy (FE-SEM), fluorescence staining, and cell re-plating experiments. The microtissues of both cell types were viable after being extracted from the alginate membrane using alginate lyase. However, the microtissues of HaCaT and ORL-48 demonstrated differences in both nucleus size and morphology. The microtissues with re-associated cells in spheroids are potentially useful as a cell model for pharmacological studies.
  19. ERG oncoprotein expression in prostate carcinoma patients of different ethnicities
    Kelly GM, Kong YH, Dobi A, Srivastava S, Sesterhenn IA, Pathmanathan R, et al.
    Molecular and clinical oncology, 2015 Jan;3(1):23-30.
    PMID: 25469265
    Overexpression of the erythroblast transformation-specific-related gene (ERG) oncoprotein due to transmembrane protease, serine 2 (TMPRSS2)-ERG fusion, the most prevalent genomic alteration in prostate cancer (CaP), is more frequently observed among Caucasian patients compared to patients of African or Asian descent. To the best of our knowledge, this is the first study to investigate the prevalence of ERG alterations in a multiethnic cohort of CaP patients. A total of 191 formalin-fixed paraffin-embedded sections of transrectal ultrasound-guided prostate biopsy specimens, collected from 120 patients treated at the Sime Darby Medical Centre, Subang Jaya, Malaysia, were analyzed for ERG protein expression by immunohistochemistry using the anti-ERG monoclonal antibody 9FY as a surrogate for the detection of ERG fusion events. The overall frequency of ERG protein expression in the population evaluated in this study was 39.2%. Although seemingly similar to rates reported in other Asian communities, the expression of ERG was distinct amongst different ethnic groups (P=0.004). Malaysian Indian (MI) patients exhibited exceedingly high expression of ERG in their tumors, almost doubling that of Malaysian Chinese (MC) patients, whereas ERG expression was very low amongst Malay patients (12.5%). When collectively analyzing data, we observed a significant correlation between younger patients and higher ERG expression (P=0.04). The prevalence of ERG expression was significantly different amongst CaP patients of different ethnicities. The higher number of ERG-expressing tumors among MI patients suggested that the TMPRSS2-ERG fusion may be particularly important in the pathogenesis of CaP amongst this group of patients. Furthermore, the more frequent expression of ERG among the younger patients analyzed suggested an involvement of ERG in the early onset of CaP. The results of this study underline the value of using ERG status to better understand the differences in the etiology of CaP initiation and progression between ethnic groups.
  20. Fulltext Identification of immunogenic MAGED4B peptides for vaccine development in oral cancer immunotherapy
    Lim KP, Chun NA, Gan CP, Teo SH, Rahman ZA, Abraham MT, et al.
    Hum Vaccin Immunother, 2014;10(11):3214-23.
    PMID: 25483651 DOI: 10.4161/hv.29226
    The ever-increasing number of tumor-associated antigens has provided a major stimulus for the development of therapeutic peptides vaccines. Tumor-associated peptides can induce high immune response rates and have been developed as vaccines for several types of solid tumors, and many are at various stages of clinical testing. MAGED4B, a melanoma antigen, is overexpressed in oral squamous cell carcinoma (OSCC) and this expression promotes proliferation and cell migration. In this study, we have identified 9 short peptides derived from MAGED4B protein that are restricted in binding to the HLA subtypes common in the Asian population (HLA-A2, A11, and A24). The peptides had good binding affinity with the MHC-Class I molecules and stimulated ex-vivo IFN-gamma and Granzyme-B production in blood samples from OSCC patients, suggesting that they are immunogenic. Further, T cells stimulated with peptide-pulsed dendritic cells showed enhanced T-cell cytotoxic activity against MAGED4B-overexpressing OSCC cell lines. In summary, we have identified MAGED4B peptides that induce anti-tumor immune responses advocating that they could be further developed as vaccine candidates for the treatment of OSCC.
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