Displaying publications 81 - 100 of 656 in total

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  1. Fulltext Pair-wise comparison analysis of differential expression of mRNAs in early and advanced stage primary colorectal adenocarcinomas
    Lau TP, Roslani AC, Lian LH, Chai HC, Lee PC, Hilmi I, et al.
    BMJ Open, 2014;4(8):e004930.
    PMID: 25107436 DOI: 10.1136/bmjopen-2014-004930
    To characterise the mRNA expression patterns of early and advanced stage colorectal adenocarcinomas of Malaysian patients.
    Matched MeSH terms: Colorectal Neoplasms/genetics*
  2. Fulltext Newcastle disease virus interaction in targeted therapy against proliferation and invasion pathways of glioblastoma multiforme
    Abdullah JM, Mustafa Z, Ideris A
    Biomed Res Int, 2014;2014:386470.
    PMID: 25243137 DOI: 10.1155/2014/386470
    Glioblastoma multiforme (GBM), or grade IV glioma, is one of the most lethal forms of human brain cancer. Current bioscience has begun to depict more clearly the signalling pathways that are responsible for high-grade glioma initiation, migration, and invasion, opening the door for molecular-based targeted therapy. As such, the application of viruses such as Newcastle disease virus (NDV) as a novel biological bullet to specifically target aberrant signalling in GBM has brought new hope. The abnormal proliferation and aggressive invasion behaviour of GBM is reported to be associated with aberrant Rac1 protein signalling. NDV interacts with Rac1 upon viral entry, syncytium induction, and actin reorganization of the infected cell as part of the replication process. Ultimately, intracellular stress leads the infected glioma cell to undergo cell death. In this review, we describe the characteristics of malignant glioma and the aberrant genetics that drive its aggressive phenotype, and we focus on the use of oncolytic NDV in GBM-targeted therapy and the interaction of NDV in GBM signalling that leads to inhibition of GBM proliferation and invasion, and subsequently, cell death.
    Matched MeSH terms: Brain Neoplasms/genetics
  3. Fulltext HLA-A SNPs and amino acid variants are associated with nasopharyngeal carcinoma in Malaysian Chinese
    Chin YM, Mushiroda T, Takahashi A, Kubo M, Krishnan G, Yap LF, et al.
    Int J Cancer, 2015 Feb 1;136(3):678-87.
    PMID: 24947555 DOI: 10.1002/ijc.29035
    Nasopharyngeal carcinoma (NPC) arises from the mucosal epithelium of the nasopharynx and is constantly associated with Epstein-Barr virus type 1 (EBV-1) infection. We carried out a genome-wide association study (GWAS) of 575,247 autosomal SNPs in 184 NPC patients and 236 healthy controls of Malaysian Chinese ethnicity. Potential association signals were replicated in a separate cohort of 260 NPC patients and 245 healthy controls. We confirmed the association of HLA-A to NPC with the strongest signal detected in rs3869062 (p = 1.73 × 10(-9)). HLA-A fine mapping revealed associations in the amino acid variants as well as its corresponding SNPs in the antigen peptide binding groove (p(HLA-A-aa-site-99) = 3.79 × 10(-8), p(rs1136697) = 3.79 × 10(-8)) and T-cell receptor binding site (p(HLA-A-aa-site-145) = 1.41 × 10(-4), p(rs1059520) = 1.41 × 10(-4)) of the HLA-A. We also detected strong association signals in the 5'-UTR region with predicted active promoter states (p(rs41545520) = 7.91 × 10(-8)). SNP rs41545520 is a potential binding site for repressor ATF3, with increased binding affinity for rs41545520-G correlated with reduced HLA-A expression. Multivariate logistic regression diminished the effects of HLA-A amino acid variants and SNPs, indicating a correlation with the effects of HLA-A*11:01, and to a lesser extent HLA-A*02:07. We report the strong genetic influence of HLA-A on NPC susceptibility in the Malaysian Chinese.
    Matched MeSH terms: Nasopharyngeal Neoplasms/genetics*
  4. Fulltext PIK3CA gene amplification and PI3K p110α protein expression in breast carcinoma
    Firoozinia M, Zareian Jahromi M, Moghadamtousi SZ, Nikzad S, Abdul Kadir H
    Int J Med Sci, 2014;11(6):620-5.
    PMID: 24782652 DOI: 10.7150/ijms.8251
    A family of PI3Ks is the lipid kinases, which enhance intracellular pools of phosphatidyl inositol 3,4,5-tri-phosphate (PIP3) through phosphorylating its precursor. Amplifications and deletions of genes, as well as somatic missense of the PIK3CA gene have been described in many human cancer varieties, including of the brain, colon, liver, lung and stomach. Immunohistochemistry and Real-time quantitative PCR tests were used to determine the PIK3CA gene amplification (gene copy number) and to detect protein expression, respectively. The results obtained were analysed and the ratio of PIK3CA to β-actin gene copy number was calculated. Positive gene amplification of PIK3CA was appointed as a copy number of ≥4. Also, PI3K p110α protein expression was scored from 0 to 3+ and the scores of 2+ and 3+ were considered as positive for PI3K p110α protein expression. We studied 50 breast carcinoma samples for PI3K p110α protein expression and PIK3CA gene copy numbers. In general, 36 out of 50 (72%) breast carcinoma samples showed a significant increase in PIK3CA gene amplification. 12 out of 50 (24%) showed positive staining, and 38 out of 50 (76%) showed negative staining for PI3K p110α expression. We have identified no significant relationship between PIK3CA amplification, race (p= 0.630) and histological type (p=0. 731) in breast carcinoma, but correlation of PIK3CA amplification and age showed a significant relationship (p=0. 003) between them. No significant relationship has been identified in correlation of PI3K p110α protein expression compared to age (p=0. 284), race (p=0. 546) and histological type (p=0. 285). Amplification of PIK3CA was frequent in breast carcinoma and occurs in stages of breast carcinoma. Our result shows that there is a relationship between gene amplification and age in breast carcinoma. We suggest that PIK3CA is significant in breast tumorigenesis serve as a prevalent mechanism contributes to the oncogenic activation pathway of PIK3CA in breast cancer.
    Matched MeSH terms: Breast Neoplasms/genetics*
  5. Genomic DNA copy number alterations from precursor oral lesions to oral squamous cell carcinoma
    Salahshourifar I, Vincent-Chong VK, Kallarakkal TG, Zain RB
    Oral Oncol, 2014 May;50(5):404-12.
    PMID: 24613650 DOI: 10.1016/j.oraloncology.2014.02.005
    Oral cancer is a multifactorial disease in which both environmental and genetic factors contribute to the aetiopathogenesis. Oral cancer is the sixth most common cancer worldwide with a higher incidence among Melanesian and South Asian countries. More than 90% of oral cancers are oral squamous cell carcinoma (OSCC). The present study aimed to determine common genomic copy number alterations (CNAs) and their frequency by including 12 studies that have been conducted on OSCCs using array comparative genomic hybridization (aCGH). In addition, we reviewed the literature dealing with CNAs that drive oral precursor lesions to the invasive tumors. Results showed a sequential accumulation of genetic changes from oral precursor lesions to invasive tumors. With the disease progression, accumulation of genetic changes increases in terms of frequency, type and size of the abnormalities, even on different regions of the same chromosome. Gains in 3q (36.5%), 5p (23%), 7p (21%), 8q (47%), 11q (45%), 20q (31%) and losses in 3p (37%), 8p (18%), 9p (10%) and 18q (11%) were the most common observations among those studies. However, losses are less frequent than gains but it appears that they might be the primary clonal events in causing oral cancer.
    Matched MeSH terms: Mouth Neoplasms/genetics*
  6. Fulltext Analysis of TP53 gene expression and p53 level of human hypopharyngeal FaDu (HTB-43) head and neck cancer cell line after microRNA-181a inhibition
    Cheah YK, Cheng RW, Yeap SK, Khoo CH, See HS
    Genet. Mol. Res., 2014;13(1):1679-83.
    PMID: 24535903 DOI: 10.4238/2014.January.22.4
    The identification of new biomarkers for early detection of highly recurrent head and neck cancer is urgently needed. MicroRNAs (miRNAs) are small and non-coding RNAs that regulate cancer-related gene expression, such as tumor protein 53 (TP53) gene expression. This study was carried out to analyze TP53 gene expression using real-time PCR and to determine changes in intracellular p53 level by flow cytometry after downregulation of miRNA-181a miRNA inhibitor in the FaDu cell line. TP53 gene expression showed a 3-fold increment and the p53 protein level was also increased in the miRNA-181a-treated cells. In conclusion, miRNA-181a binds to the TP53 gene and inhibits its expression, decreasing the synthesis of p53.
    Matched MeSH terms: Head and Neck Neoplasms/genetics*
  7. Exploring cancer development in adulthood: cholinesterase depression and genotoxic effect from chronic exposure to organophosphate pesticides among rural farm children
    How V, Hashim Z, Ismail P, Md Said S, Omar D, Bahri Mohd Tamrin S
    J Agromedicine, 2014;19(1):35-43.
    PMID: 24417530 DOI: 10.1080/1059924X.2013.866917
    Children are the vulnerable group in the agricultural community due to their early exposure to pesticides through the dynamic interplay between genetic predisposition, environment, and host-related factors. This study aims to identify the possible association between the depression in blood cholinesterase level and genotoxic effect among farm children. The results of micronuclei assay and comet assay showed that the reduced blood cholinesterase level from organophosphate pesticide exposure is significantly associated with an increase in chromosome breakage and DNA strand breaks. These genotoxicity end points suggest that farm children's cells experience early DNA damage that may lead to uncontrolled cell proliferation during their adulthood. Thus, farm children who grow up near pesticide-treated farmland have a higher probability of developing cancer than children with minimal or zero exposure to pesticides.
    Matched MeSH terms: Neoplasms/genetics
  8. Fulltext RsaI but not DraI polymorphism in CYP2E1 gene increases the risk of gastrointestinal cancer in Malaysians: a case-control study
    Chong ET, Lee CC, Chua KH, Chuah JA, Lee PC
    BMJ Open, 2014;4(1):e004109.
    PMID: 24394801 DOI: 10.1136/bmjopen-2013-004109
    Our study aimed to investigate the association of CYP2E1 C-1019T RsaI and T7678A DraI polymorphisms and factors such as age, gender and ethnicity to the risk of gastrointestinal cancer (GIC) in Malaysians.
    Matched MeSH terms: Gastrointestinal Neoplasms/genetics*
  9. Fulltext Functional roles of fibroblast growth factor receptors (FGFRs) signaling in human cancers
    Tiong KH, Mah LY, Leong CO
    Apoptosis, 2013 Dec;18(12):1447-68.
    PMID: 23900974 DOI: 10.1007/s10495-013-0886-7
    The fibroblast growth factor receptors (FGFRs) regulate important biological processes including cell proliferation and differentiation during development and tissue repair. Over the past decades, numerous pathological conditions and developmental syndromes have emerged as a consequence of deregulation in the FGFRs signaling network. This review aims to provide an overview of FGFR family, their complex signaling pathways in tumorigenesis, and the current development and application of therapeutics targeting the FGFRs signaling for treatment of refractory human cancers.
    Matched MeSH terms: Neoplasms/genetics
  10. Fulltext SNP array technology: an array of hope in breast cancer research
    Ho CC, Mun KS, Naidu R
    Malays J Pathol, 2013 Jun;35(1):33-43.
    PMID: 23817393 MyJurnal
    Breast cancer is the most common malignancy in women worldwide. The incidence of breast cancer in Malaysia is lower compared to international statistics, with peak occurrence in the age group between 50 to 59 years of age and mortality rates of 18.6%. Despite current diagnostic and prognostic methods, the outcome for individual subjects remain poor. This is in part due to breast cancers' wide genetic heterogeneity. Various platforms for genetics studies are now employed to determine the identity of these genetic abnormalities, including microarray methods like high density single-nucleotide-polymorphism (SNP) oligonucleotide arrays which combine the power of chromosomal comparative genomic hybridization (cCGH) and loss of heterozygosity (LOH) in the offering of higher-resolution mappings. These platforms and their applications in highlighting the genomic alteration frameworks manifested in breast carcinoma will be discussed.
    Matched MeSH terms: Breast Neoplasms/genetics*
  11. Strategies and challenges for systematically mapping biologically significant molecular pathways regulating carcinoma epithelial-mesenchymal transition
    Said NA, Simpson KJ, Williams ED
    Cells Tissues Organs (Print), 2013;197(6):424-34.
    PMID: 23774256 DOI: 10.1159/000351717
    Enormous progress has been made towards understanding the role of specific factors in the process of epithelial-mesenchymal transition (EMT); however, the complex underlying pathways and the transient nature of the transition continues to present significant challenges. Targeting tumour cell plasticity underpinning EMT is an attractive strategy to combat metastasis. Global gene expression profiling and high-content analyses are among the strategies employed to identify novel EMT regulators. In this review, we highlight several approaches to systematically interrogate key pathways involved in EMT, with particular emphasis on the features of multiparametric, high-content imaging screening strategies that lend themselves to the systematic discovery of highly significant modulators of tumour cell plasticity.
    Matched MeSH terms: Neoplasms/genetics
  12. Fulltext Oral cancer prognosis based on clinicopathologic and genomic markers using a hybrid of feature selection and machine learning methods
    Chang SW, Abdul-Kareem S, Merican AF, Zain RB
    BMC Bioinformatics, 2013;14:170.
    PMID: 23725313 DOI: 10.1186/1471-2105-14-170
    Machine learning techniques are becoming useful as an alternative approach to conventional medical diagnosis or prognosis as they are good for handling noisy and incomplete data, and significant results can be attained despite a small sample size. Traditionally, clinicians make prognostic decisions based on clinicopathologic markers. However, it is not easy for the most skilful clinician to come out with an accurate prognosis by using these markers alone. Thus, there is a need to use genomic markers to improve the accuracy of prognosis. The main aim of this research is to apply a hybrid of feature selection and machine learning methods in oral cancer prognosis based on the parameters of the correlation of clinicopathologic and genomic markers.
    Matched MeSH terms: Mouth Neoplasms/genetics
  13. Dysregulation of miR-31 and miR-375 expression is associated with clinical outcomes in oral carcinoma
    Siow MY, Ng LP, Vincent-Chong VK, Jamaludin M, Abraham MT, Abdul Rahman ZA, et al.
    Oral Dis, 2014 May;20(4):345-51.
    PMID: 23651447 DOI: 10.1111/odi.12118
    To identify differentially expressed miRNA between oral squamous cell carcinoma (OSCC) and non-cancer (NC) and to associate these with clinico-pathological parameters.
    Matched MeSH terms: Mouth Neoplasms/genetics*
  14. Fulltext Detection of epidermal growth factor receptor mutations in formalin fixed paraffin embedded biopsies in Malaysian non-small cell lung cancer patients
    Shi Yeen TN, Pathmanathan R, Shiran MS, Ahmad Zaid FA, Cheah YK
    J Biomed Sci, 2013 Apr 16;20:22.
    PMID: 23590575 DOI: 10.1186/1423-0127-20-22
    BACKGROUND: Somatic mutations of the epidermal growth factor receptor (EGFR) are reportedly associated with various responses in non-small cell lung cancer (NSCLC) patients receiving the anti-EGFR agents. Detection of the mutation therefore plays an important role in therapeutic decision making. The aim of this study was to detect EGFR mutations in formalin fixed paraffin embedded (FFPE) samples using both Scorpion ARMS and high resolution melt (HRM) assay, and to compare the sensitivity of these methods.

    RESULTS: All of the mutations were found in adenocarcinoma, except one that was in squamous cell carcinoma. The mutation rate was 45.7% (221/484). Complex mutations were also observed, wherein 8 tumours carried 2 mutations and 1 tumour carried 3 mutations.

    CONCLUSIONS: Both methods detected EGFR mutations in FFPE samples. HRM assays gave more EGFR positive results compared to Scorpion ARMS.

    Matched MeSH terms: Lung Neoplasms/genetics*
  15. Influences of multiple genetic polymorphisms on ovarian cancer risk in Malaysia
    Velapasamy S, Alex L, Chahil JK, Lye SH, Munretnam K, Hashim NA, et al.
    Genet Test Mol Biomarkers, 2013 Jan;17(1):62-8.
    PMID: 23113749 DOI: 10.1089/gtmb.2012.0223
    The identification of high-risk individuals can help to improve early cancer detection and patient survival. Risk assessment, however, can only be accomplished if the risk factors are known. To date, the genetic risk factors for ovarian cancer, other than mutations in the BRCA1/2 genes, have never been systematically explored in Malaysia. The present study aims to identify from a panel of cancer-associated single-nucleotide polymorphisms (SNPs), those associated with ovarian cancer risk in Malaysia.
    Matched MeSH terms: Ovarian Neoplasms/genetics*
  16. Early detection of pancreatic cancer: a possibility in some cases but not a reality in most
    Goh KL, Yoon BK
    J Dig Dis, 2012 Aug;13(8):389-92.
    PMID: 22788923 DOI: 10.1111/j.1751-2980.2012.00609.x
    Pancreatic cancer is notoriously difficult to diagnose until a late stage when curative options are no longer available. Owing to its relatively low incidence and the lack of sensitivity of current diagnostic tool, screening of pancreatic cancer in the general population is not recommended. However, in high-risk individuals, especially those with well-described genetic syndromes and a strong family history of pancreatic cancer, screening can be carried out. Detection of a lesion of the diameter 
    Matched MeSH terms: Pancreatic Neoplasms/genetics
  17. Fulltext The inference of breast cancer metastasis through gene regulatory networks
    Ahmad FK, Deris S, Othman NH
    J Biomed Inform, 2012 Apr;45(2):350-62.
    PMID: 22179053 DOI: 10.1016/j.jbi.2011.11.015
    Understanding the mechanisms of gene regulation during breast cancer is one of the most difficult problems among oncologists because this regulation is likely comprised of complex genetic interactions. Given this complexity, a computational study using the Bayesian network technique has been employed to construct a gene regulatory network from microarray data. Although the Bayesian network has been notified as a prominent method to infer gene regulatory processes, learning the Bayesian network structure is NP hard and computationally intricate. Therefore, we propose a novel inference method based on low-order conditional independence that extends to the case of the Bayesian network to deal with a large number of genes and an insufficient sample size. This method has been evaluated and compared with full-order conditional independence and different prognostic indices on a publicly available breast cancer data set. Our results suggest that the low-order conditional independence method will be able to handle a large number of genes in a small sample size with the least mean square error. In addition, this proposed method performs significantly better than other methods, including the full-order conditional independence and the St. Gallen consensus criteria. The proposed method achieved an area under the ROC curve of 0.79203, whereas the full-order conditional independence and the St. Gallen consensus criteria obtained 0.76438 and 0.73810, respectively. Furthermore, our empirical evaluation using the low-order conditional independence method has demonstrated a promising relationship between six gene regulators and two regulated genes and will be further investigated as potential breast cancer metastasis prognostic markers.
    Matched MeSH terms: Breast Neoplasms/genetics*
  18. A modified binary particle swarm optimization for selecting the small subset of informative genes from gene expression data
    Mohamad MS, Omatu S, Deris S, Yoshioka M
    IEEE Trans Inf Technol Biomed, 2011 Nov;15(6):813-22.
    PMID: 21914573 DOI: 10.1109/TITB.2011.2167756
    Gene expression data are expected to be of significant help in the development of efficient cancer diagnoses and classification platforms. In order to select a small subset of informative genes from the data for cancer classification, recently, many researchers are analyzing gene expression data using various computational intelligence methods. However, due to the small number of samples compared to the huge number of genes (high dimension), irrelevant genes, and noisy genes, many of the computational methods face difficulties to select the small subset. Thus, we propose an improved (modified) binary particle swarm optimization to select the small subset of informative genes that is relevant for the cancer classification. In this proposed method, we introduce particles' speed for giving the rate at which a particle changes its position, and we propose a rule for updating particle's positions. By performing experiments on ten different gene expression datasets, we have found that the performance of the proposed method is superior to other previous related works, including the conventional version of binary particle swarm optimization (BPSO) in terms of classification accuracy and the number of selected genes. The proposed method also produces lower running times compared to BPSO.
    Matched MeSH terms: Neoplasms/genetics
  19. Fulltext The contribution of reproductive factors and family history towards premenopausal breast cancer risk in Kuala Lumpur, Malaysia
    Razif SM, Sulaiman S, Hanie SS, Aina EN, Rohaizak M, Fuad I, et al.
    Med J Malaysia, 2011 Aug;66(3):220-6.
    PMID: 22111444 MyJurnal
    Breast cancer is the most common cancer among Malaysian women. This study aimed to determine the reproductive for premenopausal breast cancer risk in Kuala Lumpur, Malaysia. A case-control study was conducted in 216 histopathologically confirmed cases of premenopausal breast cancer and 216 community-based controls that were matched by age within a 5-year period and ethnicity. The results of this study showed that premenopausal breast cancer risks were strongly related to parity, number of live births and family history of breast cancer. Premenopausal women with these known reproductive and family history risk factors should take extra measures to undergo appropriate screening method for early detection of breast cancer.
    Matched MeSH terms: Breast Neoplasms/genetics
  20. Chromosomal alterations in Malaysian patients with nasopharyngeal carcinoma analyzed by comparative genomic hybridization
    Natasya Naili MN, Hasnita CH, Shamim AK, Hasnan J, Fauziah MI, Narazah MY, et al.
    Cancer Genet. Cytogenet., 2010 Dec;203(2):309-12.
    PMID: 21156250 DOI: 10.1016/j.cancergencyto.2010.07.136
    Nasopharyngeal carcinoma (NPC) is one of the most common cancers in Malaysia, mainly occurring among the Chinese population. To detect common genetic alterations in NPC, we screened seven cases of NPC using the comparative genomic hybridization (CGH) technique. Before proceeding to the CGH technique, the tumors were first confirmed to consist of 75% tumor cells or more. In brief, the technique consists of binding tumor DNA with normal DNA and human Cot-1 DNA, which is then hybridized to normal metaphase spreads. The slides were then counterstained with 4,6 diamino-2-phenylindole (DAPI II) for detection. Analyses were performed using CGH software (Cytovision). We found genetic alterations in all seven NPC samples. The common chromosomal gains (57%, four cases) were found on chromosome arms 1q, 4p, 5, 7q, 11, 14p, 15q, 18p, and 21p, and common chromosomal losses (43%, three cases) were found on chromosome arm 16p. Our results showed chromosomal alterations in all seven NPC cases in the Malaysian population. This result provides the platform for further investigations to locate tumor suppressor genes and oncogenes at specific chromosomal regions in Malaysian NPC patients.
    Matched MeSH terms: Nasopharyngeal Neoplasms/genetics
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