Displaying publications 81 - 100 of 154 in total

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  1. Khosravi Y, Loke MF, Goh KL, Vadivelu J
    Front Microbiol, 2016;7:1462.
    PMID: 27695448
    Helicobacter pylori is the dominant species of the human gastric microbiota and is present in the stomach of more than half of the human population worldwide. Colonization by H. pylori causes persistent inflammatory response and H. pylori-induced gastritis is the strongest singular risk factor for the development of gastric adenocarcinoma. However, only a small proportion of infected individuals develop malignancy. Besides H. pylori, other microbial species have also been shown to be related to gastritis. We previously reported that interspecies microbial interaction between H. pylori and S. mitis resulted in alteration of their metabolite profiles. In this study, we followed up by analyzing the changing protein profiles of H. pylori and S. mitis by LC/Q-TOF mass spectrometry to understand the different response of the two bacterial species in a multi-species micro-environment. Differentially-expressed proteins in mono- and co-cultures could be mapped into 18 biological pathways. The number of proteins involve in RNA degradation, nucleotide excision repair, mismatch repair, and lipopolysaccharide (LPS) biosynthesis were increased in co-cultured H. pylori. On the other hand, fewer proteins involve in citrate cycle, glycolysis/ gluconeogenesis, aminoacyl-tRNA biosynthesis, translation, metabolism, and cell signaling were detected in co-cultured H. pylori. This is consistent with our previous observation that in the presence of S. mitis, H. pylori was transformed to coccoid. Interestingly, phosphoglycerate kinase (PGK), a major enzyme used in glycolysis, was found in abundance in co-cultured S. mitis and this may have enhanced the survival of S. mitis in the multi-species microenvironment. On the other hand, thioredoxin (TrxA) and other redox-regulating enzymes of H. pylori were less abundant in co-culture possibly suggesting reduced oxidative stress. Oxidative stress plays an important role in tissue damage and carcinogenesis. Using the in vitro co-culture model, this study emphasized the possibility that pathogen-microbiota interaction may have a protective effect against H. pylori-associated carcinogenesis.
    Matched MeSH terms: Carcinogenesis
  2. Chia, W.K., Zubaidah, Z., Reena Rahayu Md Zin, Rohaizak, M., Asmiati, A., Rafie, M.K., et al.
    Medicine & Health, 2012;7(1):47-56.
    MyJurnal
    Aneusomy is an early genetic event and a characteristic feature of many solid tumors. It is often associated with poor prognosis in cancer patients. The involvement of PAX8-PPARγ rearrangement in tumorigenesis of follicular thyroid lesions has been widely assessed. However, there were few reports on aneusomy of the PPARγ gene at the 3p25 locus in follicular thyroid lesions. It remains undetermined whether these abnormalities can be translated into improved diagnosis, classification, or outcome prediction. Herein, we report three cases of follicular thyroid neoplasms [two follicular thyroid carcinomas (FTCs) and one Hurthle cell adenoma (HCA)] with 3p25 aneusomy detected by fluorescence in situ hybridization (FISH). 3p25 trisomy was observed in one FTC and one HCA while 3p25 tetrasomy was observed in one FTC. Furthermore, all three lesions did not show overexpression of PPARγ protein. Hurthle cell neoplasms (HCN) are distinct clinically and histologically from other follicular thyroid neoplasms (FTN). However, the presence of the aneusomy in HCA and FTC indicates that there could be a biological continuum between the two and chromosomal gains might play an important role in the pathogenesis of these two types of neoplasms. Despite their differences, HCN and FTN may share the same early genetic event in tumour development.
    Matched MeSH terms: Carcinogenesis
  3. Mdzin, R., Lau, T.Y., Rohaizak, M., Sharifah, N.A.
    Medicine & Health, 2012;7(1):32-40.
    MyJurnal
    The tumour suppressor gene p53 and the proto-oncogene Bcl-2 encode respectively, for a nuclear phosphoprotein and for a mitochondrial membrane protein involved in multiple cellular functions. Both proteins are linked to programmed cell death pathways and provide prognostic information on breast carcinoma. Our aim is to study the expression of p53 and Bcl-2 oncoproteins in breast carcinoma and correlate with patients’ age, tumour size, disease stage and histological grade. Fifty nine cases of breast carcinomas from Universiti Kebangsaan Malaysia Medical Centre (UKMMC) were studied with the immunohistochemical method. Our results showed 45.8% (27 of 59) and 40.7% (24 of 59) of the breast carcinomas were immunopositive for p53 and Bcl-2 respectively. There was significant correlation between Bcl-2 expression with early tumour stage (p=0.01). No significant relationship was seen with other variables. Results also showed an inverse relationship between p53 and Bcl-2 expression (p=0.001). These findings indicate a down regulation of Bcl-2 by p53 in breast carcinogenesis.
    Matched MeSH terms: Carcinogenesis
  4. Ma, M.S.
    Malaysian Dental Journal, 2007;28(2):78-82.
    MyJurnal
    Squamous cell carcinoma (SCC) is the commonest cancer in the mouth. Multiple risk factors, such as smoking, alcohol consumption, irradiation, viruses infection and chronic irritation are thought to be responsible for the formation of oral squamous cell carcinoma. Although SCC can develop through a series of precancerous stages manifested as various degrees of epithelial dysplasia, this is not always the case. p53 is the commonest mutated gene in human cancers. Mis-sense mutation of the gene or complexing of the protein with viral or cellular proteins prolongs its half-life and leads to its detection by immunohistochemistry. This study was designed with the aim of demonstrating any possible relationship between p53 and oral squamous cell carcinoma by immunohistochemical staining techniques. A total of 66 specimens from the oral cavity (10 normal mucosa, 11 hyperkeratosis without dysplasia, 11 mild dysplasia, 11 moderate dysplasia, 10 severe dysplasia and 13 SCC) were examined for the presence of p53. The results show p53 was not expressed in normal mucosa, but was found with increasing frequency in increasingly severe dysplasia and SCC. In conclusion, this study shows p53 mutation is common in oral squamous cell carcinoma and probably occurs early in the multisteps of oral carcinogenesis.
    Matched MeSH terms: Carcinogenesis
  5. Lau MF, Vellasamy S, Chua KH, Sabaratnam V, Kuppusamy UR
    EXCLI J, 2018;17:186-199.
    PMID: 29743857 DOI: 10.17179/excli2018-1011
    Colorectal cancer (CRC) is the third most leading cause of morbidity and mortality throughout the world. 5-fluorouracil (5-FU), which is often administrated to disrupt carcinogenesis, was found to elevate blood glucose level among CRC patients. Thus, this study was conducted to evaluate the influence of rosiglitazone on antiproliferative effect of 5-FU using cellular model. Two human colonic carcinoma cell lines (HCT 116 and HT 29) were cultured in the presence of 5-FU, rosiglitazone or in combination under normal and high glucose concentration. The drug cytotoxicity was evaluated using the MTT assay whereas the assessment of cell cycle was carried out using the flow cytometry technique. Combination index (CI) method was used to determine the drug interaction between rosiglitazone and 5-FU. High glucose diminished the cytotoxic effect of 5-FU but at a high drug dosage, this effect could be overcome. Cell cycle analysis demonstrated that 5-FU and rosiglitazone caused G1-phase arrest and S-phase arrest, respectively. CI values indicated that rosiglitazone exerted synergistic effect on 5-FU regardless of glucose levels. This study is the first to demonstrate the influence of rosiglitazone on cytotoxicity of 5-FU under normal or high glucose level. Rosiglitazone may be a promising drug for enhancing the efficacy of 5-FU in the treatment of CRC associated with hyperglycemia.
    Matched MeSH terms: Carcinogenesis
  6. Faiz NM, Cortes AL, Guy JS, Reddy SM, Gimeno IM
    J Gen Virol, 2018 07;99(7):927-936.
    PMID: 29767614 DOI: 10.1099/jgv.0.001076
    Marek's disease virus (MDV) is a herpesvirus that induces lymphoma and a variety of non-neoplastic syndromes in chickens. Furthermore, very virulent plus (vv+) MDVs induce a form of immunosuppression (late-MDV-IS) that might involve both neoplastic and non-neoplastic mechanisms. The objective of this study was to evaluate whether the attenuation of MDV-induced tumours and late-MDV-IS occurs simultaneously or can be dissociated. The immunosuppressive ability of three viruses derived from vv+ MDV strain 686 (wild-type 686, the somewhat attenuated molecular clone 686-BAC, and the nononcogenic molecular clone lacking the two copies of the oncogene meq 686-BACΔMEQ) was evaluated. Late-MDV-IS was evaluated indirectly by assessing the negative effect of MDV strains on the protection conferred by infectious laryngotracheitis (ILT) vaccines. Our results showed that the ability to induce late-MDV-IS was attenuated before the ability to induce tumours. Strain 686 induced both tumours and late-MDV-IS, 686-BAC induced tumours but did not induce late-MDV-IS and 686-BACΔMEQ did not induce either tumours or late-MDV-IS. Further comparison of strains 686 and 686-BAC revealed that strain 686 reduced the humoral immune responses to ILTV (1132 vs 2167) more severely, showed higher levels of meq transcripts (2.1E+09 vs 4.98E+8) and higher expression of MDV microRNAs (mdv1-miR-M4-5p and mdv1-miR-M2-3p) in the spleen, and further reduced the percentage of CD45+-MHC-I+splenocytes (13 vs32 %) compared to molecular clone 686-BAC. This study suggests that the immunosuppressive ability of MDV might follow a continuous spectrum and only the most virulent MDVs can overcome a certain threshold level and induce clinical MDV-IS in the ILT model.
    Matched MeSH terms: Carcinogenesis/genetics; Carcinogenesis/immunology*; Carcinogenesis/pathology
  7. Aminuddin A, Ng PY
    Front Pharmacol, 2016;7:244.
    PMID: 27570510 DOI: 10.3389/fphar.2016.00244
    Canonical Wnt signaling pathway, also known as Wnt/β-catenin signaling pathway, is a crucial mechanism for cellular maintenance and development. It regulates cell cycle progression, apoptosis, proliferation, migration, and differentiation. Dysregulation of this pathway correlates with oncogenesis in various tissues including breast, colon, pancreatic as well as head and neck cancers. Furthermore, the canonical Wnt signaling pathway has also been described as one of the critical signaling pathways for regulation of normal stem cells as well as cancer cells with stem cell-like features, termed cancer stem cells (CSC). In this review, we will briefly describe the basic mechanisms of Wnt signaling pathway and its crucial roles in the normal regulation of cellular processes as well as in the development of cancer. Next, we will highlight the roles of canonical Wnt signaling pathway in the regulation of CSC properties namely self-renewal, differentiation, metastasis, and drug resistance abilities, particularly in head and neck squamous cell carcinoma. Finally, we will examine the findings of several recent studies which explore druggable targets in the canonical Wnt signaling pathway which could be valuable to improve the treatment outcome for head and neck cancer.
    Matched MeSH terms: Carcinogenesis
  8. Cheah PL, Li J, Looi LM, Teoh KH, Ong DB, Arends MJ
    PeerJ, 2018;6:e5530.
    PMID: 30221090 DOI: 10.7717/peerj.5530
    Background: Except for a few studies with contradictory observations, information is lacking on the possibility of association between DNA mismatch repair (MMR) status and the presence of cancer stem cells in colorectal carcinoma (CRC), two important aspects in colorectal carcinogenesis.

    Methods: Eighty (40 right-sided and 40 left-sided) formalin-fixed, paraffin-embedded primary CRC were immunohistochemically studied for CD133, a putative CRC stem cell marker, and MMR proteins MLH1, MSH2, MSH6 and PMS2. CD133 expression was semi-quantitated for proportion of tumor immunopositivity on a scale of 0-5 and staining intensity on a scale of 0-3 with a final score (units) being the product of proportion and intensity of tumor staining. The tumor was considered immunopositive only when the tumor demonstrated moderate to strong intensity of CD133 staining (a decision made after analysis of CD133 expression in normal colon). Deficient MMR (dMMR) was interpreted as unequivocal loss of tumor nuclear staining for any MMR protein despite immunoreactivity in the internal positive controls.

    Results: CD133 was expressed in 36 (90.0%) left-sided and 28 (70.0%) right-sided tumors (p  0.05).

    Conclusion: Proficient MMR correlated with high levels of CD133-marked putative cancer stem cells in both right- and left-sided tumors, whereas significantly lower levels of CD133-marked putative cancer stem cells were associated with deficient MMR status in colorectal carcinomas found on the right.

    Matched MeSH terms: Carcinogenesis
  9. Mohd Rohaizad Md Roduan, Norhafizah Mohtarrudin, Chong PP, Malina Osman, Noraini Mohd Dusa
    Sains Malaysiana, 2015;44:727-733.
    Inflammation plays an important role to the process of prostate carcinogenesis by increasing the rate of cell proliferation,
    which contributes to an aggressive tumour phenotype. Cyclooxygenase-2 (COX-2) has been found overexpressed in
    various types of cancer cells including prostate. The aim of this study was to investigate the COX-2 expressions in different
    types of human prostate tissues. Paraffin-embedded prostate tissues from 263 samples were examined for the expression
    of COX-2 marker by immunohistochemistry method. COX-2 was found highly expressed in prostate adenocarcinoma
    (p=0.001) as compared to benign and normal tissues. The score of COX-2 expressions in most of normal prostate was
    weak 49 (77.8%), while only 16 (16%) of BPH showed strong expression. 56 cases (56%) prostate cancer showed strong
    COX-2 expression. Prostate cancer cases showed significant differences in staining patterns as tumour grade increased.
    In addition, COX-2 expression was significantly correlated with Gleason score in cancerous tissues. This study suggests
    that COX-2 overexpression is associated with prostate cancer and higher grade tumour.
    Matched MeSH terms: Carcinogenesis
  10. Liu C, Hirakawa H, Tanaka K, Mohd Saaya F, Nenoi M, Fujimori A, et al.
    Dose Response, 2019 03 04;17(1):1559325819833840.
    PMID: 30858771 DOI: 10.1177/1559325819833840
    Radiotherapy (RT) treats cancer effectively with high doses of ionizing radiation (IR) to killing cancer cells and shrinking tumors while bearing the risk of developing different side effects, including secondary cancer, which is most concerning for long-term health consequences. Genomic instability (GI) is a characteristic of most cancer cells, and IR-induced GI can manifest as delayed homologous recombination (HR). Radioadaptive response (RAR) is capable of reducing genotoxicity, cell transformation, mutation, and carcinogenesis, but the rational evidence describing its contributions to the reduction of radiation risk, in particular, carcinogenesis, remains fragmented. In this work, to investigate the impact of RAR on high-dose, IR-induced GI measured as delayed HR, the frequency of recombinant cells was comparatively studied under RAR-inducible and -uninducible conditions in the nucleated cells in hematopoietic tissues (bone marrow and spleen) using the Rosa26 Direct Repeat-green fluorescent protein (RaDR-GFP) homozygote mice. Results demonstrated that the frequency of recombinant cells was significantly lower in hematopoietic tissues under RAR-inducible condition. These findings suggest that reduction in delayed HR may be at least a part of the mechanisms underlying decreased carcinogenesis by RAR, and application of RAR would contribute to a more rigorous and scientifically grounded system of radiation protection in RT.
    Matched MeSH terms: Carcinogenesis
  11. Thomson PJ, Goodson ML, Cocks K, Turner JE
    Int J Oral Maxillofac Surg, 2017 Mar;46(3):337-342.
    PMID: 27866683 DOI: 10.1016/j.ijom.2016.11.001
    Oral squamous cell carcinoma (OSCC) is a lethal disease, with rising incidence. There were 6767 new OSCC cases and 2056 deaths in the UK in 2011. Cancers are preceded by oral potentially malignant disorders (PMDs), recognizable mucosal diseases harbouring increased SCC risk, offering clinicians a 'therapeutic window' to intervene. Contemporary practice remains unable to predict lesion behaviour or quantify malignant transformation risk. No clear management guidelines exist and it is unclear from the literature whether early diagnosis and intervention prevents cancer. Between 1996 and 2014, 773 laser treatments were performed on 590 PMD patients in Newcastle maxillofacial surgery departments. The efficacy of the intervention was examined by review of the clinicopathological details and clinical outcomes of the patients (mean follow-up 7.3 years). Histopathology required up-grading in 36.1% on examining excision specimens. Seventy-five percent of patients were disease-free, mostly younger patients with low-grade dysplasia; 9% exhibited persistent disease and were generally older with proliferative verrucous leukoplakia. Disease-free status was less likely for erythroleukoplakia (P=0.022), 'high-grade' dysplasia (P<0.0001), and with lichenoid inflammation (P=0.028). Unexpected OSCC was identified in 12.0%, whilst 4.8% transformed to malignancy. Interventional laser surgery facilitates definitive diagnosis and treatment, allows early diagnosis of OSCC, identifies progressive disease, and defines outcome categories. Evidence is lacking that intervention halts carcinogenesis. Multicentre, prospective, randomized controlled trials are needed to confirm the efficacy of surgery.
    Matched MeSH terms: Carcinogenesis
  12. Mohamed Yusoff AA, Mohd Nasir KN, Haris K, Mohd Khair SZN, Abdul Ghani ARI, Idris Z, et al.
    Oncol Lett, 2017 Nov;14(5):5179-5188.
    PMID: 29098023 DOI: 10.3892/ol.2017.6851
    Although the role of nuclear-encoded gene alterations has been well documented in brain tumor development, the involvement of the mitochondrial genome in brain tumorigenesis has not yet been fully elucidated and remains controversial. The present study aimed to identify mutations in the mitochondrial DNA (mtDNA) control region D-loop in patients with brain tumors in Malaysia. A mutation analysis was performed in which DNA was extracted from paired tumor tissue and blood samples obtained from 49 patients with brain tumors. The D-loop region DNA was amplified using the PCR technique, and genetic data from DNA sequencing analyses were compared with the published revised Cambridge sequence to identify somatic mutations. Among the 49 brain tumor tissue samples evaluated, 25 cases (51%) had somatic mutations of the mtDNA D-loop, with a total of 48 mutations. Novel mutations that had not previously been identified in the D-loop region (176 A-deletion, 476 C>A, 566 C>A and 16405 A-deletion) were also classified. No significant associations between the D-loop mutation status and the clinicopathological parameters were observed. To the best of our knowledge, the current study presents the first evidence of alterations in the mtDNA D-loop regions in the brain tumors of Malaysian patients. These results may provide an overview and data regarding the incidence of mitochondrial genome alterations in Malaysian patients with brain tumors. In addition to nuclear genome aberrations, these specific mitochondrial genome alterations may also be considered as potential cancer biomarkers for the diagnosis and staging of brain cancers.
    Matched MeSH terms: Carcinogenesis
  13. Othman NH
    PMID: 22761637 DOI: 10.1155/2012/410406
    Honey and cancer has a sustainable inverse relationship. Carcinogenesis is a multistep process and has multifactorial causes. Among these are low immune status, chronic infection, chronic inflammation, chronic non healing ulcers, obesity, and so forth. There is now a sizeable evidence that honey is a natural immune booster, natural anti-inflammatory agent, natural antimicrobial agent, natural cancer "vaccine," and natural promoter for healing chronic ulcers and wounds. Though honey has substances of which the most predominant is a mixture of sugars, which itself is thought to be carcinogenic, it is understandable that its beneficial effect as anticancer agent raises skeptics. The positive scientific evidence for anticancer properties of honey is growing. The mechanism on how honey has anticancer effect is an area of great interest. Among the mechanisms suggested are inhibition of cell proliferation, induction of apoptosis, and cell-cycle arrest. Honey and cancer has sustainable inverse relationship in the setting of developing nations where resources for cancer prevention and treatment are limited.
    Matched MeSH terms: Carcinogenesis
  14. Movahedi A, Basir R, Rahmat A, Charaffedine M, Othman F
    PMID: 25197311 DOI: 10.1155/2014/726724
    The term cancer has been concomitant with despair, agony, and dreadful death. Like many other diseases, herbal therapy has been used to prevent or suppress cancer. The present study investigated the capability of the decoction of Teucrium polium L. from Lamiaceae family to protect liver cells against hepatocellular carcinoma in carcinogenesis-induced animal model. After 28 weeks of treatment with decoction of Teucrium polium L., serum biochemical markers including ALT, AST, AFP, GGT, ALP, HCY, TNF-α, α2MG, and CBG have been regulated auspiciously. Total antioxidant status also has been increased intensely. Liver lesion score in treated group was lessened and glucocorticoid activity has been intensified significantly. In conclusion, Teucrium polium L. decoction might inhibit or suppress liver cancer development.
    Matched MeSH terms: Carcinogenesis
  15. Baharuddin WNA, Yusoff AAM, Abdullah JM, Osman ZF, Ahmad F
    Malays J Med Sci, 2018 Nov;25(6):22-27.
    PMID: 30914876 DOI: 10.21315/mjms2018.25.6.3
    Glioblastoma multiforme (GBM) is one of the most common primary brain tumours in adults, accounting for almost 65% of all cases. Among solid tumours, GBM is characterised by strong angiogenesis, including the highest degree of vascular proliferation and endothelial cell hyperplasia. Despite numerous improvements in existing treatment approaches, the prognosis of GBM patients remains poor, with a mean survival of only 14.6 months. Growing evidence has shown significant overexpression of the ephrin type-A receptor 2 (EphA2) receptor in various malignancies, including GBM, as well as a correlation to poor prognoses. It is believed that EphA2 receptors play important roles in mediating GBM tumourigenesis, including invasion, metastasis, and angiogenesis. Despite the clinical and pathological importance of tumour-associated vasculature, the underlying mechanism involving EphA2 is poorly known. Here, we have summarised the current knowledge in the field regarding EphA2 receptors' roles in the angiogenesis of GBM.
    Matched MeSH terms: Carcinogenesis
  16. Rahmat A, Seam CK, Endrini S, Mansor SM
    Malays J Med Sci, 2001 Jan;8(1):41-5.
    PMID: 22973155
    Milk is a physiological fluid which has high nutritional value and soybean has strong antioxidant characteristics which is believed to inhibit carcinogenesis. The objective of this study was to investigate the effects of administration of soybean and goat's milk on hepatocarcinogenesis in rats (fed with diethylnitrosamine; DEN and acetylaminofluorene; AAF) by determining the activities of plasma gamma-glutamyl transpeptidase (GGT) and alkaline phosphatase (ALP). Thirty-six rats from the species Sprague-Dawley were divided into 6 groups : control, DEN/AAF, soybean, DEN/AAF with soybean treatment, goat's milk and DEN/AAF with goat's milk treatment. Soybean and goat's milk administrations were given 5 ml/day. The rats were sacrificed after 8 weeks and the blood was collected. Treatment with DEN/AAF caused an increase in ALP and GGT levels and a decrease in weight significantly (p<0.05). ALP and GGT activities decreased significantly after administration of soybean and goat's milk (p<0.05). Administration of goat's milk and soybean alone did not cause any changes in the enzyme activities. Comparison between the effect of soybean and goat's milk in reducing the enzyme activities (ALP and GGT) did not give significant values (p>0.05). However, a decrease in weight was observed in the rats given soybean as well as goat's milk. The results obtained suggested that soybean and goat's milk may work as anti cancer agents in hepatocarcinogenesis although further studies are required to further elucidate this aspect.
    Matched MeSH terms: Carcinogenesis
  17. Erejuwa OO, Sulaiman SA, Wahab MS
    Molecules, 2014;19(2):2497-522.
    PMID: 24566317 DOI: 10.3390/molecules19022497
    Honey is a natural product known for its varied biological or pharmacological activities-ranging from anti-inflammatory, antioxidant, antibacterial, antihypertensive to hypoglycemic effects. This review article focuses on the role of honey in modulating the development and progression of tumors or cancers. It reviews available evidence (some of which is very recent) with regards to the antimetastatic, antiproliferative and anticancer effects of honey in various forms of cancer. These effects of honey have been thoroughly investigated in certain cancers such as breast, liver and colorectal cancer cell lines. In contrast, limited but promising data are available for other forms of cancers including prostate, bladder, endometrial, kidney, skin, cervical, oral and bone cancer cells. The article also underscores the various possible mechanisms by which honey may inhibit growth and proliferation of tumors or cancers. These include regulation of cell cycle, activation of mitochondrial pathway, induction of mitochondrial outer membrane permeabilization, induction of apoptosis, modulation of oxidative stress, amelioration of inflammation, modulation of insulin signaling and inhibition of angiogenesis. Honey is highly cytotoxic against tumor or cancer cells while it is non-cytotoxic to normal cells. The data indicate that honey can inhibit carcinogenesis by modulating the molecular processes of initiation, promotion, and progression stages. Thus, it may serve as a potential and promising anticancer agent which warrants further experimental and clinical studies.
    Matched MeSH terms: Carcinogenesis/drug effects
  18. Isyraqiah F, Kutty MK, Durairajanayagam D, Singh HJ
    Mol Biol Rep, 2019 Dec;46(6):5967-5975.
    PMID: 31444698 DOI: 10.1007/s11033-019-05030-z
    Individuals who are obese are at a greater risk of developing gastric cancer. They are however also hyperleptinaemic. Chronic leptin treatment has been shown to upregulate numerous cancer-causing genes in the stomach of male Sprague-Dawley rats. It is however unclear if leptin enhances the effect of gastric carcinogens in vivo. This study was therefore done to investigate the effect of leptin on gastric carcinogenesis in rats treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Twenty-four, 6-week old male Sprague-Dawley rats were divided equally into three groups: G1 served as age-matched controls; G2 was treated with MNNG in drinking water ad libitum (200 mg L-1); G3 was given leptin and MNNG. Rats were euthanized after 40 weeks of treatment and their stomachs were removed for histopathology, microarray, and RT-qPCR analysis. Fisher's exact test and one-way ANOVA were used to analyse the data. Fifty percent of the MNNG-treated rats developed gastric hyperplasia (p 
    Matched MeSH terms: Carcinogenesis/pathology
  19. Md Roduan MR, Abd Hamid R, Mohtarrudin N
    BMC Complement Altern Med, 2019 Sep 03;19(1):238.
    PMID: 31481122 DOI: 10.1186/s12906-019-2650-1
    BACKGROUND: Annonacin, an annonaceous acetogenin isolated from Annona muricata has been reported to be strongly cytotoxic against various cell lines, in vitro. Nevertheless, its effect against in vivo tumor promoting activity has not been reported yet. Therefore, this study was aimed to investigate antitumor-promoting activity of annonacin via in vivo two-stage mouse skin tumorigenesis model and its molecular pathways involved.

    METHODS: Mice were initiated with single dose of 7,12-dimethylbenz[α]anthracene (DMBA) (390 nmol/100 μL) followed by, in subsequent week, repeated promotion (twice weekly; 22 weeks) with 12-O-tetradecanoylphorbol-13-acetate (TPA) (1.7 nmol/100 μL). Annonacin (85 nM) and curcumin (10 mg/kg; reference) were, respectively, applied topically to DMBA/TPA-induced mice 30 min before each TPA application for 22 weeks. Upon termination, histopathological examination of skin, liver and kidney as well as genes and proteins expression analysis were conducted to elucidate the potential mechanism of annonacin.

    RESULTS: With comparison to the carcinogen control, Annonacin significantly increased the tumor latency period and reduced the tumor incidence, tumor burden and tumor volume, respectively. In addition, it also suppressed tumorigenesis manifested by significant reduction of hyperkeratosis, dermal papillae and number of keratin pearls on skin tissues. Annonacin also appeared to be non-toxic to liver and kidney. Significant modulation of both AKT, ERK, mTOR, p38, PTEN and Src genes and proteins were also observed in annonacin-targeted signaling pathway(s) against tumorigenesis.

    CONCLUSIONS: Collectively, results of this study indicate that annonacin is a potential therapeutic compound targeting tumor promoting stage in skin tumorigenesis by modulating multiple gene and protein in cancer signaling pathways without apparent toxicity.

    Matched MeSH terms: Carcinogenesis/drug effects*
  20. Minning C, Mokhtar NM, Abdullah N, Muhammad R, Emran NA, Ali SA, et al.
    Int J Oncol, 2014 Nov;45(5):1959-68.
    PMID: 25175708 DOI: 10.3892/ijo.2014.2625
    There have been many DNA methylation studies on breast cancer which showed various methylation patterns involving tumour suppressor genes and oncogenes but only a few of those studies link the methylation data with gene expression. More data are required especially from the Asian region and to analyse how the epigenome data correlate with the transcriptome. DNA methylation profiling was carried out on 76 fresh frozen primary breast tumour tissues and 25 adjacent non-cancerous breast tissues using the Illumina Infinium(®) HumanMethylation27 BeadChip. Validation of methylation results was performed on 7 genes using either MS-MLPA or MS-qPCR. Gene expression profiling was done on 15 breast tumours and 5 adjacent non-cancerous breast tissues using the Affymetrix GeneChip(®) Human Gene 1.0 ST array. The overlapping genes between DNA methylation and gene expression datasets were further mapped to the KEGG database to identify the molecular pathways that linked these genes together. Supervised hierarchical cluster analysis revealed 1,389 hypermethylated CpG sites and 22 hypomethylated CpG sites in cancer compared to the normal samples. Gene expression microarray analysis using a fold-change of at least 1.5 and a false discovery rate (FDR) at p>0.05 identified 404 upregulated and 463 downregulated genes in cancer samples. Integration of both datasets identified 51 genes with hypermethylation with low expression (negative association) and 13 genes with hypermethylation with high expression (positive association). Most of the overlapping genes belong to the focal adhesion and extracellular matrix-receptor interaction that play important roles in breast carcinogenesis. The present study displayed the value of using multiple datasets in the same set of tissues and how the integrative analysis can create a list of well-focused genes as well as to show the correlation between epigenetic changes and gene expression. These gene signatures can help us understand the epigenetic regulation of gene expression and could be potential targets for therapeutic intervention in the future.
    Matched MeSH terms: Carcinogenesis/genetics*
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