Displaying publications 161 - 180 of 415 in total

Abstract:
Sort:
  1. Mohamed GA, Al-Abd AM, El-Halawany AM, Abdallah HM, Ibrahim SRM
    J Ethnopharmacol, 2017 Feb 23;198:302-312.
    PMID: 28108382 DOI: 10.1016/j.jep.2017.01.030
    ETHNOPHARMACOLOGICAL RELEVANCE: Cancer has proceeded to surpass one of the most chronic illnesses to be the major cause of mortality in both the developing and developed world. Garcinia mangostana L. (mangosteen, family Guttiferae) known as the queen of fruits, is one of the most popular tropical fruits. It is cultivated in Southeast Asian countries: Malaysia, Indonesia, Sri Lanka, Burma, Thailand, and Philippines. Traditionally, numerous parts of G. mangostana have been utilized to treat various ailments such as abdominal pain, haemorrhoids, food allergies, arthritis, leucorrhoea, gonorrhea, diarrhea, dysentery, wound infection, suppuration, and chronic ulcer.

    AIM OF STUDY: Although anticancer activity has been reported for the plant, the goal of the study was designed to isolate and characterize the active metabolites from G. mangostana and measure their cytotoxic properties. In this research, the mechanism of antiproliferative/cytotoxic effects of the tested compounds was investigated.

    MATERIALS AND METHODS: The CHCl3 fraction of the air-dried fruit hulls was repeatedly chromatographed on SiO2, RP18, Diaion HP-20, and polyamide columns to furnish fourteen compounds. The structures of these metabolites were proven by UV, IR, 1D, and 2D NMR measurements and HRESIMS. Additionally, the cytotoxic potential of all compounds was assessed against MCF-7, HCT-116, and HepG2 cell lines using SRB-U assay. Antiproliferative and cell cycle interference effects of potentially potent compounds were tested using DNA content flow cytometry. The mechanism of cell death induction was also studied using annexin-V/PI differential staining coupled with flow cytometry.

    RESULTS: The CHCl3 soluble fraction afforded two new xanthones: mangostanaxanthones V (1) and VI (2), along with twelve known compounds: mangostanaxanthone IV (3), β-mangostin (4), garcinone E (5), α-mangostin (6), nor-mangostin (7), garcimangosone D (8), aromadendrin-8-C-β-D-glucopyranoside (9), 1,2,4,5-tetrahydroxybenzene (10), 2,4,3`-trihydroxybenzophenone-6-O-β-glucopyranoside (11), maclurin-6-O-β-D-glucopyranoside (rhodanthenone) (12), epicatechin (13), and 2,4,6,3`,5`-pentahydroxybenzophenone (14). Only compound 5 showed considerable antiproliferative/cytotoxic effects with IC50's ranging from 15.8 to 16.7µM. Compounds 3, 4, and 6 showed moderate to weak cytotoxic effects (IC50's ranged from 45.7 to 116.4µM). Using DNA content flow cytometry, it was found that only 5 induced significant cell cycle arrest at G0/G1-phase which is indicative of its antiproliferative properties. Additionally, by using annexin V-FITC/PI differential staining, 5 induced cells killing effect via the induction of apoptosis and necrosis in both HepG2 and HCT116 cells. Compound 3 produce necrosis and apoptosis only in HCT116 cells. On contrary, 6 induced apoptosis and necrosis in HepG2 cells and moderate necrosis in HCT116 cells.

    CONCLUSION: Fourteen compounds were isolated from chloroform fraction of G. mangostana fruit hulls. Cytotoxic properties exhibited by the isolated xanthones from G. mangostana reinforce the avail of it as a natural cytotoxic agent against various cancers. These evidences could provide relevant bases for the scientific rationale of using G. mangostana in anti-cancer treatment.

    Matched MeSH terms: Colorectal Neoplasms/drug therapy; Colorectal Neoplasms/pathology
  2. Cheng KJ, Alshawsh MA, Mejia Mohamed EH, Thavagnanam S, Sinniah A, Ibrahim ZA
    Cell Oncol (Dordr), 2020 Apr;43(2):177-193.
    PMID: 31677065 DOI: 10.1007/s13402-019-00477-5
    BACKGROUND: In recent years, the high mobility group box-1 (HMGB1) protein, a damage-associated molecular pattern (DAMP) molecule, has been found to play multifunctional roles in the pathogenesis of colorectal cancer. Although much attention has been given to the diagnostic and prognostic values of HMGB1 in colorectal cancer, the exact functional roles of the protein as well as the mechanistic pathways involved have remained poorly defined. This systematic review aims to discuss what is currently known about the roles of HMGB1 in colorectal cancer development, growth and progression, and to highlight critical areas for future investigations. To achieve this, the bibliographic databases Pubmed, Scopus, Web of Science and ScienceDirect were systematically screened for articles from inception till June 2018, which address associations of HMGB1 with colorectal cancer.

    CONCLUSIONS: HMGB1 plays multiple roles in promoting the pathogenesis of colorectal cancer, despite a few contradicting studies. HMGB1 may differentially regulate disease-related processes, depending on the redox status of the protein in colorectal cancer. Binding of HMGB1 to various protein partners may alter the impact of HMGB1 on disease progression. As HMGB1 is heavily implicated in the pathogenesis of colorectal cancer, it is crucial to further improve our understanding of the functional roles of HMGB1 not only in colorectal cancer, but ultimately in all types of cancers.

    Matched MeSH terms: Colorectal Neoplasms/genetics*; Colorectal Neoplasms/metabolism; Colorectal Neoplasms/pathology
  3. Teo MYM, Ng JJC, Fong JY, Hwang JS, Song AA, Lim RLH, et al.
    PeerJ, 2021;9:e11063.
    PMID: 33959410 DOI: 10.7717/peerj.11063
    Background: KRAS oncogenes harboring codon G12 and G13 substitutions are considered gatekeeper mutations which drive oncogenesis in many cancers. To date, there are still no target-specific vaccines or drugs available against this genotype, thus reinforcing the need towards the development of targeted therapies such as immunotoxins.

    Methods: This study aims to develop a recombinant anti-mKRAS scFv-fused mutant Hydra actinoporin-like-toxin-1 (mHALT-1) immunotoxin that is capable of recognizing and eradicating codon-12 mutated k-ras antigen abnormal cells. One G13D peptide mimotope (164-D) and one G12V peptide mimotope (68-V) were designed to elicit antigen specific IgG titres against mutated K-ras antigens in immunised Balb/c mice. The RNA was extracted from splenocytes following ELISA confirmation on post-immunized mice sera and was reverse transcribed into cDNA. The scFv combinatorial library was constructed from cDNA repertoire of variable regions of heavy chain (VH) and light chain (VL) fusions connected by a flexible glycine-serine linker, using splicing by overlap extension PCR (SOE-PCR). Anti-mKRAS G12V and G13D scFvs were cloned in pCANTAB5E phagemid and superinfected with helper phage. After few rounds of bio-panning, a specific mKRAS G12V and G13D scFv antibody against G12V and G13D control mimotope was identified and confirmed using ELISA without any cross-reactivity with other mimotopes or controls. Subsequently, the anti-mKRAS scFv was fused to mHALT-1 using SOE-PCR and cloned in pET22b vector. Expressed recombinant immunotoxins were analyzed for their effects on cell proliferation by the MTT assay and targeted specificity by cell-based ELISA on KRAS-positive and KRAS-negative cancer cells.

    Results: The VH and VL genes from spleen RNA of mice immunized with 164-D and 68-V were amplified and randomly linked together, using SOE-PCR producing band sizes about 750 bp. Anti-mKRAS G12V and G13D scFvs were constructed in phagemid pCANTAB5E vectors with a library containing 3.4 × 106 and 2.9 × 106 individual clones, respectively. After three rounds of bio-panning, the anti-mKRAS G12V-34 scFv antibody against G12V control mimotope was identified and confirmed without any cross-reactivity with other controls using ELISA. Anti-mKRAS G12V-34 scFv fragment was fused to mHALT-1 toxin and cloned in pET22b vector with expression as inclusion bodies in E. coli BL21(DE3) (molecular weight of ~46.8 kDa). After successful solubilization and refolding, the mHALT-1-scFv immunotoxin exhibited cytotoxic effects on SW-480 colorectal cancer cells with IC50 of 25.39 μg/mL, with minimal cytotoxicity effect on NHDF cells.

    Discussion: These results suggested that the development of such immunotoxins is potentially useful as an immunotherapeutic application against KRAS-positive malignancies.

    Matched MeSH terms: Colorectal Neoplasms
  4. Wong YP, Shah SA, Shaari N, Mohamad Esa MS, Sagap I, Isa NM
    Asian Pac J Cancer Prev, 2014;15(4):1725-30.
    PMID: 24641399
    Management of patients with stage II colorectal carcinomas remains challenging as 20 - 30% of them will develop recurrence. It is postulated that these patients may harbour nodal micrometastases which are imperceptible by routine histopathological evaluation. The aims of our study were to evaluate (1) the feasibility of multilevel sectioning method utilizing haematoxylin and eosin stain and immunohistochemistry technique with cytokeratin AE1/AE3, in detecting micrometastases in histologically-negative lymph nodes, and (2) correlation between nodal micrometastases with clinicopathological parameters. Sixty two stage I and II cases with a total of 635 lymph nodes were reviewed. Five-level haematoxylin and eosin staining and one-level cytokeratin AE1/AE3 immunostaining were performed on all lymph nodes retrieved. The findings were correlated with clinicopathological parameters. Two (3.2%) lymph nodes in two patients (one in each) were found to harbour micrometastases detected by both methods. With cytokeratin AE1/AE3, we successfully identified four (6.5%) patients with isolated tumour cells, but none through the multilevel sectioning method. Nodal micrometastases detected by both multilevel sectioning and immunohistochemistry methods were not associated with larger tumour size, higher depth of invasion, poorer tumour grade, disease recurrence or distant metastasis. We conclude that there is no difference between the two methods in detecting nodal micrometastases. Therefore it is opined that multilevel sectioning is a feasible and yet inexpensive method that may be incorporated into routine practice to detect nodal micrometastases in centres with limited resources.
    Matched MeSH terms: Colorectal Neoplasms/pathology*; Colorectal Neoplasms/surgery
  5. Pandurangan AK, Saadatdoust Z, Esa NM, Hamzah H, Ismail A
    Biofactors, 2015 Jan-Feb;41(1):1-14.
    PMID: 25545372 DOI: 10.1002/biof.1195
    Colorectal cancer (CRC) is the third most common malignancy in males and the second most common cancer worldwide. Chronic colonic inflammation is a known risk factor for CRC. Cocoa contains many polyphenolic compounds that have beneficial effects in humans. The objective of this study is to explore the antioxidant properties of cocoa in the mouse model of azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colitis-associated cancer, focusing on the activation of Nrf2 signaling. Mice were treated with AOM/DSS and randomized to receive either a control diet or a 5 and 10% cocoa diet during the study period. On day 62 of the experiment, the entire colon was processed for biochemical and histopathological examination and further evaluations. Increased levels of malondialdehyde (MDA) were observed in AOM/DSS-induced mice; however, subsequent administration of cocoa decreased the MDA. Enzymatic and nonenzymatic antioxidants, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, were decreased in the AOM/DSS mice. Cocoa treatment increases the activities/levels of enzymatic and nonenzymatic antioxidants. Inflammatory mediators, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, were elevated during AOM/DSS-induction, and treatment with 5 and 10% cocoa effectively decreases the expression of iNOS and COX-2. The NF-E2-related factor 2 and its downstream targets, such as NQO1 and UDP-GT, were increased by cocoa treatment. The results of our study suggest that cocoa may merit further clinical investigation as a chemopreventive agent that helps prevent CAC.
    Matched MeSH terms: Colorectal Neoplasms/chemically induced; Colorectal Neoplasms/diet therapy; Colorectal Neoplasms/genetics; Colorectal Neoplasms/prevention & control*
  6. Ho K, Yazan LS, Ismail N, Ismail M
    Cancer Epidemiol, 2009 Aug;33(2):155-60.
    PMID: 19679064 DOI: 10.1016/j.canep.2009.06.003
    Vanillin is responsible for the flavor and smell of vanilla, a widely used flavoring agent. Previous studies showed that vanillin could enhance the repair of mutations and thus function as an anti-mutagen. However, its role in cancer, a disease that is closely related to mutation has not yet been fully elucidated.
    Matched MeSH terms: Colorectal Neoplasms/drug therapy*; Colorectal Neoplasms/pathology*
  7. Ho KL, Chong PP, Yazan LS, Ismail M
    J Med Food, 2012 Dec;15(12):1096-102.
    PMID: 23216109 DOI: 10.1089/jmf.2012.2245
    Vanillin is the substance responsible for the flavor and smell of vanilla, a widely used flavoring agent. Previous studies reported that vanillin is a good antimutagen and anticarcinogen. However, there are also some contradicting findings showing that vanillin was a comutagen and cocarcinogen. This study investigated whether vanillin is an anticarcinogen or a cocarcinogen in rats induced with azoxymethane (AOM). Rats induced with AOM will develop aberrant crypt foci (ACF). AOM-challenged rats were treated with vanillin orally and intraperitoneally at low and high concentrations and ACF density, multiplicity, and distribution were observed. The gene expression of 14 colorectal cancer-related genes was also studied. Results showed that vanillin consumed orally had no effect on ACF. However, high concentrations (300 mg/kg body weight) of vanillin administered through intraperitoneal injection could increase ACF density and ACF multiplicity. ACF were mainly found in the distal colon rather than in the mid-section and proximal colon. The expression of colorectal cancer biomarkers, protooncogenes, recombinational repair, mismatch repair, and cell cycle arrest, and tumor suppressor gene expression were also affected by vanillin. Vanillin was not cocarcinogenic when consumed orally. However, it was cocarcinogenic when being administered intraperitoneally at high concentration. Hence, the use of vanillin in food should be safe but might have cocarcinogenic potential when it is used in high concentration for therapeutic purposes.
    Matched MeSH terms: Colorectal Neoplasms/drug therapy*; Colorectal Neoplasms/pathology
  8. Yoshida N, Naito Y, Yasuda R, Murakami T, Hirose R, Ogiso K, et al.
    Int J Colorectal Dis, 2017 Sep;32(9):1253-1260.
    PMID: 28725959 DOI: 10.1007/s00384-017-2855-z
    PURPOSE: Linked color imaging (LCI) by laser endoscopy is a novel narrow band light observation. In this study, we analyzed the efficacy of LCI for improving the various featured colorectal polyp's visibility utilizing a subjective endoscopist's visibility scoring and objective color difference (CD) value.

    METHODS: We retrospectively reviewed two pictures both with white light (WL) and LCI for 54 consecutive neoplastic polyps 2-20 mm in size. All pictures were evaluated by four endoscopists according to a published polyp visibility score from four (excellent visibility) to one (poor visibility). Additionally, we calculated CD value between each polyp and surrounding mucosa in LCI and WL using an original software.

    RESULTS: The mean polyp visibility scores of LCI (3.11 ± 1.05) were significantly higher than those of WL (2.50 ± 1.09, P 

    Matched MeSH terms: Colorectal Neoplasms/pathology*
  9. Mollica MA, Mayer DK, Oeffinger KC, Kim Y, Buckenmaier SS, Sivaram S, et al.
    JCO Glob Oncol, 2020 09;6:1394-1411.
    PMID: 32955943 DOI: 10.1200/GO.20.00180
    PURPOSE: The purpose of this study was to describe follow-up care for breast and colorectal cancer survivors in countries with varying levels of resources and highlight challenges regarding posttreatment survivorship care.

    METHODS: We surveyed one key stakeholder from each of 27 countries with expertise in survivorship care on questions including the components/structure of follow-up care, delivery of treatment summaries and survivorship care plans, and involvement of primary care in survivorship. Descriptive analyses were performed to characterize results across countries and variations between the WHO income categories (low, middle, high). We also performed a qualitative content analysis of narratives related to survivorship care challenges to identify major themes.

    RESULTS: Seven low- or /lower-middle-income countries (LIC/LMIC), seven upper-middle-income countries (UMIC), and 13 high-income countries (HICs) were included in this study. Results indicate that 44.4% of countries with a National Cancer Control Plan currently address survivorship care. Additional findings indicate that HICs use guidelines more often than those in LICs/LMICs and UMICs. There was great variation among countries regardless of income level. Common challenges include issues with workforce, communication and care coordination, distance/transportation issues, psychosocial support, and lack of focus on follow-up care.

    CONCLUSION: This information can guide researchers, providers, and policy makers in efforts to improve the quality of survivorship care on a national and global basis. As the number of cancer survivors increases globally, countries will need to prioritize their long-term needs. Future efforts should focus on efforts to bridge oncology and primary care, building international partnerships, and implementation of guidelines.

    Matched MeSH terms: Colorectal Neoplasms
  10. Shah SA, Neoh HM, Rahim SS, Azhar ZI, Hassan MR, Safian N, et al.
    Asian Pac J Cancer Prev, 2014;15(3):1149-54.
    PMID: 24606433
    BACKGROUND: In Malaysia, data from the Malaysian Health Ministry showed colorectal cancer (CRC) to be the second most common type of cancer in 2007-2009, after breast cancer. The same was apparent after looking at males and females cases separately. In the present study, the Geographic Information System (GIS) was employed to describe the distribution of CRC cases in Kuala Lumpur (KL), Malaysia, according to socio-demographic factors (age, gender, ethnicity and district).

    MATERIALS AND METHODS: This retrospective review concerned data for patients diagnosed with colorectal cancer in the years 1995 to 2011 collected from the Wilayah Persekutuan Health Office, taken from the cancer notification form (NCR-2), and patient medical records from the Surgical Department, Universiti Kebangsaan Malaysia Medical Centre (UKMMC). A total of 146 cases were analyzed. All the data collected were analysed using ArcGIS version 10.0 and SPSS version 19.0.

    RESULTS: Patients aged 60 to 69 years accounted for the highest proportion of cases (34.2%) and males slightly predominated 76 (52.1%), Chinese had the highest number of registered cases at 108 (74.0%) and staging revealed most cases in the 3rd and 4th stages. Kernel density analysis showed more cases are concentrated up in the northern area of Petaling and Kuala Lumpur subdistricts. Spatial global pattern analysis by average nearest neighbour resulted in nearest neighbour ratio of 0.75, with Z-score of -5.59, p value of <0.01 and the z-score of -5.59. Spatial autocorrelation (Moran's I) showed clustering significant with p<0.01, Z score 3.14 and Moran's Index of 0.007. When mapping clusters with hotspot analysis (Getis-Ord Gi), hot and cold spots were identified. Hot spot areas fell on the northeast side of KL.

    CONCLUSIONS: This study demonstrated significant spatial patterns of cancer incidence in KL. Knowledge about these spatial patterns can provide useful information to policymakers in the planning of screening of CRC in the targeted population and improvement of healthcare facilities to provide better treatment for CRC patients.

    Matched MeSH terms: Colorectal Neoplasms/epidemiology*
  11. Kok-Sin T, Mokhtar NM, Ali Hassan NZ, Sagap I, Mohamed Rose I, Harun R, et al.
    Oncol Rep, 2015 Jul;34(1):22-32.
    PMID: 25997610 DOI: 10.3892/or.2015.3993
    Apart from genetic mutations, epigenetic alteration is a common phenomenon that contributes to neoplastic transformation in colorectal cancer. Transcriptional silencing of tumor-suppressor genes without changes in the DNA sequence is explained by the existence of promoter hypermethylation. To test this hypothesis, we integrated the epigenome and transcriptome data from a similar set of colorectal tissue samples. Methylation profiling was performed using the Illumina InfiniumHumanMethylation27 BeadChip on 55 paired cancer and adjacent normal epithelial cells. Fifteen of the 55 paired tissues were used for gene expression profiling using the Affymetrix GeneChip Human Gene 1.0 ST array. Validation was carried out on 150 colorectal tissues using the methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) technique. PCA and supervised hierarchical clustering in the two microarray datasets showed good separation between cancer and normal samples. Significant genes from the two analyses were obtained based on a ≥2-fold change and a false discovery rate (FDR) p-value of <0.05. We identified 1,081 differentially hypermethylated CpG sites and 36 hypomethylated CpG sites. We also found 709 upregulated and 699 downregulated genes from the gene expression profiling. A comparison of the two datasets revealed 32 overlapping genes with 27 being hypermethylated with downregulated expression and 4 hypermethylated with upregulated expression. One gene was found to be hypomethylated and downregulated. The most enriched molecular pathway identified was cell adhesion molecules that involved 4 overlapped genes, JAM2, NCAM1, ITGA8 and CNTN1. In the present study, we successfully identified a group of genes that showed methylation and gene expression changes in well-defined colorectal cancer tissues with high purity. The integrated analysis gives additional insight regarding the regulation of colorectal cancer-associated genes and their underlying mechanisms that contribute to colorectal carcinogenesis.
    Matched MeSH terms: Colorectal Neoplasms/genetics*; Colorectal Neoplasms/pathology
  12. Megat Mohd Azlan PI, Chin SF, Low TY, Neoh HM, Jamal R
    Proteomics, 2019 05;19(10):e1800176.
    PMID: 30557447 DOI: 10.1002/pmic.201800176
    Dysbiosis of gut microbiome can contribute to inflammation, and subsequently initiation and progression of colorectal cancer (CRC). Throughout these stages, various proteins and metabolites are secreted to the external environment by microorganisms or the hosts themselves. Studying these proteins may help enhance our understanding of the host-microorganism relationship or they may even serve as useful biomarkers for CRC. However, secretomic studies of gut microbiome of CRC patients, until now, are scarcely performed. In this review article, the focus is on the roles of gut microbiome in CRC, the current findings on CRC secretome are highlighted, and the emerging challenges and strategies to drive forward this area of research are addressed.
    Matched MeSH terms: Colorectal Neoplasms/diagnosis*; Colorectal Neoplasms/microbiology*
  13. Nawi AM, Chin SF, Mazlan L, Jamal R
    Sci Rep, 2020 10 29;10(1):18670.
    PMID: 33122698 DOI: 10.1038/s41598-020-75760-9
    The burden of colorectal cancer (CRC) is increasing worldwide especially in developing countries. This phenomenon may be attributable to lifestyle, dietary and environmental risk factors. We aimed to determine the level of 25 trace elements, their interaction with environmental risk factors, and subsequently develop a risk prediction model for CRC (RPM CRC). For the discovery phase, we used a hospital-based case-control study (CRC and non-CRC patients) and in the validation phase we analysed pre-symptomatic samples of CRC patients from The Malaysian Cohort Biobank. Information on the environmental risk factors were obtained and level of 25 trace elements measured using the ICP-MS method. CRC patients had lower Zn and Se levels but higher Li, Be, Al, Co, Cu, As, Cd, Rb, Ba, Hg, Tl, and Pb levels compared to non-CRC patients. The positive interaction between red meat intake ≥ 50 g/day and Co ≥ 4.77 µg/L (AP 0.97; 95% CI 0.91, 1.03) doubled the risk of CRC. A panel of 24 trace elements can predict simultaneously and accurate of high, moderate, and low risk of CRC (accuracy 100%, AUC 1.00). This study provides a new input on possible roles for various trace elements in CRC as well as using a panel of trace elements as a screening approach to CRC.
    Matched MeSH terms: Colorectal Neoplasms/etiology; Colorectal Neoplasms/mortality; Colorectal Neoplasms/epidemiology*
  14. Abu N, Othman N, Ab Razak NS, Bakarurraini NAAR, Nasir SN, Soh JEC, et al.
    Front Cell Dev Biol, 2020;8:564648.
    PMID: 33324632 DOI: 10.3389/fcell.2020.564648
    Colorectal cancer (CRC) is one of the most widely diagnosed cancers worldwide. It has been shown that the body-mass index (BMI) of the patients could influence the tumor microenvironment, treatment response, and overall survival rates. Nevertheless, the mechanism on how BMI affects the tumorigenesis process, particularly the tumor microenvironment is still elusive. Herein, we postulate that extracellular vesicles (EVs) from CRC patients and non-CRC volunteers with different BMI could affect immune cells differently, in CD8 T cells particularly. We isolated the EVs from the archived serum of CRC patients with high and low BMI, as well as healthy controls with similar BMI status. The EVs were further characterized via electron microscopy, western blot and dynamic light scattering. Then, functional analysis was performed on CD8 T cells including apoptosis, cell proliferation, gene expression profiling and cytokine release upon co-incubation with the different EVs. Our results suggest that CRC-derived EVs were able to regulate the CD8 T cells. In some assays, low BMI EVs were functionally different than high BMI EVs. This study highlights the possible difference in the regulatory mechanism of cancer patients-derived EVs, especially on CD8 T cells.
    Matched MeSH terms: Colorectal Neoplasms
  15. Abdul Murad NA, Othman Z, Khalid M, Abdul Razak Z, Hussain R, Nadesan S, et al.
    Dig Dis Sci, 2012 Nov;57(11):2863-72.
    PMID: 22669205 DOI: 10.1007/s10620-012-2240-2
    BACKGROUND: Colorectal cancer (CRC) is the third most common cancer worldwide with approximately 1 million cases diagnosed annually. In Malaysia, CRC is the second most common cancer in women and ranked first in men. The underlying cause of CRC remains unknown.

    AIMS: The aim of this study was to analyze the mutations in genes involved in CRC including MLH1, MSH2, KRAS, and APC genes.

    METHODS: A total of 76 patients were recruited. We used the polymerase chain reaction-denaturing high-performance liquid chromatography for the detection of mutations in the mismatch repair (MMR) and APC genes and the PCR single-strand conformation polymorphism for screening of the KRAS gene mutations.

    RESULTS: We identified 17 types of missense mutations in 38 out of 76 patients in our patients. Nine mutations were identified in the APC gene, five mutations were detected in the KRAS gene, and two mutations were identified in the MSH2 gene. Only one mutation was identified in MLH1. Out of these 17 mutations, eight mutations (47 %) were predicted to be pathogenic. Seven patients were identified with multiple mutations (3: MSH2 and KRAS, 1: KRAS and APC, 1: MLH1 and APC, 2: APC and APC).

    CONCLUSIONS: We have established the PCR-DHPLC and PCR-SSCP for screening of mutations in CRC patients. This study has given a snapshot of the spectrum of mutations in the four genes that were analyzed. Mutation screening in patients and their family members will help in the early detection of CRC and hence will reduce mortality due to CRC.

    Matched MeSH terms: Colorectal Neoplasms/genetics*
  16. Abu N, Othman N, W Hon K, Nazarie WF, Jamal R
    Biomark Med, 2020 05;14(7):525-537.
    PMID: 32462912 DOI: 10.2217/bmm-2019-0241
    Background: Finding a new target or a new drug to overcome chemoresistance is difficult due to the heterogenous nature of cancer. Meta-analysis was performed to combine the analysis of different microarray studies to get a robust discovery. Materials & methods: Herein, we analyzed three microarray datasets on combination of folinic acid, fluorouracil, and oxaliplatin drugs (FOLFOX) resistance that fit our inclusion/exclusion criteria and performed a meta-analysis using the OmiCC system. Results: We identified several deregulated genes and we discovered HNF4A as a hub gene. We performed functional validation and observed that by targeting HNF4A, HCT116 cells were more sensitive toward both oxaliplatin and 5-fluorouracil significantly. Conclusion: Our findings show that HNF4A could be a potential target in overcoming FOLFOX chemoresistance in colorectal cancer.
    Matched MeSH terms: Colorectal Neoplasms/drug therapy*; Colorectal Neoplasms/genetics*
  17. Baharudin R, Ab Mutalib NS, Othman SN, Sagap I, Rose IM, Mohd Mokhtar N, et al.
    Front Pharmacol, 2017;8:47.
    PMID: 28243201 DOI: 10.3389/fphar.2017.00047
    Resistance to 5-Fluorouracil (5-FU) is a major obstacle to the successful treatment of colorectal cancer (CRC) and posed an increased risk of recurrence. DNA methylation has been suggested as one of the underlying mechanisms for recurrent disease and its contribution to the development of drug resistance remains to be clarified. This study aimed to determine the methylation phenotype in CRC for identification of predictive markers for chemotherapy response. We performed DNA methylation profiling on 43 non-recurrent and five recurrent CRC patients using the Illumina Infinium HumanMethylation450 Beadchip assay. In addition, CRC cells with different genetic backgrounds, response to 5-FU and global methylation levels (HT29 and SW48) were treated with 5-FU and DNA methylation inhibitor 5-aza-2'-deoxycytidine (5-azadC). The singular and combined effects of these two drug classes on cell viability and global methylation profiles were investigated. Our genome-wide methylation study on the clinical specimens showed that recurrent CRCs exhibited higher methylation levels compared to non-recurrent CRCs. We identified 4787 significantly differentially methylated genes (P < 0.05); 3112 genes were hyper- while 1675 genes were hypomethylated in the recurrent group compared to the non-recurrent. Fifty eight and 47 of the significantly hypermethylated and hypomethylated genes have an absolute recurrent/non-recurrent methylation difference of ≥20%. Most of the hypermethylated genes were involved in the MAPK signaling pathway which is a key regulator for apoptosis while the hypomethylated genes were involved in the PI3K-AKT signaling pathway and proliferation process. We also demonstrate that 5-azadC treatment enhanced response to 5-FU which resulted in significant growth inhibition compared to 5-FU alone in hypermethylated cell lines SW48. In conclusion, we found the evidence of five potentially biologically important genes in recurrent CRCs that could possibly serve as a new potential therapeutic targets for patients with chemoresistance. We postulate that aberrant methylation of CCNEI, CCNDBP1, PON3, DDX43, and CHL1 in CRC might be associated with the recurrence of CRC and 5-azadC-mediated restoration of 5-FU sensitivity is mediated at least in part by MAPK signaling pathway.
    Matched MeSH terms: Colorectal Neoplasms
  18. Osman MA, Neoh HM, Ab Mutalib NS, Chin SF, Jamal R
    Front Microbiol, 2018;9:767.
    PMID: 29755427 DOI: 10.3389/fmicb.2018.00767
    The human gut holds the densest microbiome ecosystem essential in maintaining a healthy host physiology, whereby disruption of this ecosystem has been linked to the development of colorectal cancer (CRC). The advent of next-generation sequencing technologies such as the 16S rRNA gene sequencing has enabled characterization of the CRC gut microbiome architecture in an affordable and culture-free approach. Nevertheless, the lack of standardization in handling and storage of biospecimens, nucleic acid extraction, 16S rRNA gene primer selection, length, and depth of sequencing and bioinformatics analyses have contributed to discrepancies found in various published studies of this field. Accurate characterization of the CRC microbiome found in different stages of CRC has the potential to be developed into a screening tool in the clinical setting. This mini review aims to concisely compile all available CRC microbiome studies performed till end of 2016 and to suggest standardized protocols that are crucial in developing a gut microbiome screening panel for CRC.
    Matched MeSH terms: Colorectal Neoplasms
  19. Johdi NA, Ait-Tahar K, Sagap I, Jamal R
    Front Immunol, 2017;8:620.
    PMID: 28611777 DOI: 10.3389/fimmu.2017.00620
    Regulatory T cells (Tregs), a subset of CD4(+) or CD8(+) T cells, play a pivotal role in regulating immune homeostasis. An increase in Tregs was reported in many tumors to be associated with immune suppression and evasion in cancer patients. Despite the importance of Tregs, the molecular signatures that contributed to their pathophysiological relevance remain poorly understood and controversial. In this study, we explored the gene expression profiles in Tregs derived from patients with colorectal cancer [colorectal carcinoma (CRC), n = 15], colorectal polyps (P, n = 15), and in healthy volunteers (N, n = 15). Tregs were analyzed using CD4(+)CD25(+)CD127(low)FoxP3(+) antibody markers. Gene expression profiling analysis leads to the identification of 61 and 66 immune-related genes in Tregs derived from CRC and P patients, respectively, but not in N-derived Treg samples. Of these, 30 genes were differentially expressed both in CRC- and P-derived Tregs when compared to N-derived Tregs. Most of the identified genes were involved in cytokine/chemokine mediators of inflammation, chemokine receptor, lymphocyte activation, and T cell receptor (TCR) signaling pathways. This study highlights some of the molecular signatures that may affect Tregs' expansion and possible suppression of function in cancer development. Our findings may provide a better understanding of the immunomodulatory nature of Tregs and could, therefore, open up new avenues in immunotherapy.
    Matched MeSH terms: Colorectal Neoplasms
  20. Johdi NA, Mazlan L, Sagap I, Jamal R
    Cytokine, 2017 11;99:35-42.
    PMID: 28689023 DOI: 10.1016/j.cyto.2017.06.015
    Soluble proteins including cytokines, chemokines and growth factors are small proteins that mediate and regulate immunity. They involved in the pathogenesis of many diseases including cancers. The concentration of these proteins in biological fluids (serum or plasma) and tissues in diseases may suggest pathway activation that leads to inflammatory response or disease progression. Therefore, these soluble proteins may be useful as a tool for screening, diagnosis classification between stages of disease or surveillance for therapy. Enzyme-linked immunosorbent assays (ELISA) and bioassay have been used as a gold standard in cytokine level measurements in clinical practice. However, these methods allow only single cytokine detection at a time and ineffective for screening purposes. Hence, the innovation of multiplexing technology allows measurement of many these soluble proteins simultaneously, thus allowing rapid, cost effective and better efficiency by using a minute amount of sample. In this study, we explored the profiles of key inflammatory cytokines, chemokines and other soluble proteins from the serum derived from colorectal carcinoma (CRC, n=20), colorectal polyps (P, n=20) and healthy volunteers (N, n=20) using multiplexed bead-based immunoassays. We aimed to evaluate if the levels of these soluble proteins can classify these groups of populations and explore the possible application of the soluble proteins as biomarkers in early stage screening and/or surveillance. We observed significant high IL-4, MIP-1β, FasL and TGF-β1 levels but lower levels for RANTES in P-derived serum as compared to N-derived serum. Significant high IL-8, VEGF, MIP-1β, Eotaxin and G-CSF observed in CRC-derived serum when compared to N-derived serum. Between CRC- and P-derived serum, significantly higher levels of IL-8, Eotaxin and G-CSF but lower levels for TGF-β1 were detected in CRC-derived serum. These preliminary results were obtained from small sample size and could be further validated with larger sample size cohort to produce a panel of biomarkers for CRC and P patients. Our findings might be useful in developing a disease-specific panel for biomarker screening assay. This could be used for early diagnosis and/or treatment surveillance.
    Matched MeSH terms: Colorectal Neoplasms/blood*
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links