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Fulltext Establishment and analysis of the 3-dimensional (3D) spheroids generated from the Nasopharyngeal Carcinoma cell line HK1

Muniandy, Kalaivani, Sankar, Prabu Siva, Lian, Benedict Shi Xiang, Khoo, Alan Soo-Beng, Balakrishnan, Venugopal, Mohana-Kumaran, Nethia

Trop Life Sci Res, 2016;27(11):125-130.
MyJurnal

Spheroids have been shown to recapitulate the tumour in vivo with properties
such as the tumour microenvironment, concentration gradients, and tumour phenotype. As
such, it can serve as a platform for determining the growth and invasion behaviour pattern
of the cancer cells as well as be utilised for drug sensitivity assays; capable of exhibiting
results that are closer to what is observed in vivo compared to two-dimensional (2D) cell
culture assays. This study focused on establishing a three-dimensional (3D) cell culture
model using the Nasopharyngeal Carcinoma (NPC) cell line, HK1 and analysing its growth
and invasion phenotypes. The spheroids will also serve as a model to elucidate their
sensitivity to the chemotherapeutic drug, Flavopiridol. The liquid overlay method was
employed to generate the spheroids which was embedded in bovine collagen I matrix for
growth and invasion phenotypes observation. The HK1 cells formed compact spheroids
within 72 hours. Our observation from the 3 days experiments revealed that the spheroids
gradually grew and invaded into the collagen matrix, showing that the HK1 spheroids are
capable of growth and invasion. Progressing from these experiments, the HK1 spheroids
were employed to perform a drug sensitivity assay using the chemotherapeutic drug,
Flavopiridol. The drug had a dose-dependent inhibition on spheroid growth and invasion.
Fulltext Evaluation of extraction kits and RT-qPCR systems adapted to high-throughput platform for circulating miRNAs

Tan GW, Khoo AS, Tan LP

Sci Rep, 2015;5:9430.
PMID: 25800946 DOI: 10.1038/srep09430

MicroRNAs regulate gene expression at the post-transcriptional level. Differential expression of miRNAs can potentially be used as biomarkers for early diagnosis and prediction for outcomes. Failure in validation of miRNA profiles is often caused by variations in experimental parameters. In this study, the performance of five extraction kits and three RT-qPCR systems were evaluated using BioMark high-throughput platform and the effects of different experimental parameters on circulating miRNA levels were determined. Differences in the performance of extraction kits as well as varying accuracy, sensitivity and reproducibility in qPCR systems were observed. Normalisation of RT-qPCR data to spike-in controls can reduce extraction bias. However, the extent of correlation for different qPCR systems varies in different assays. At different time points, there was no significant fold change in eight of the plasma miRNAs that we evaluated. Higher level of miRNAs was detected in plasma as compared to serum of the same cohort. In summary, we demonstrated that high-throughput RT-qPCR with pre-amplification step had increased sensitivity and can be achieved with accuracy and high reproducibility through stringent experimental controls. The information provided here is useful for planning biomarker validation studies involving circulating miRNAs.
Fulltext Pathogenic Role of Exosomes in Epstein-Barr Virus (EBV)-Associated Cancers

Teow SY, Liew K, Khoo AS, Peh SC

Int J Biol Sci, 2017;13(10):1276-1286.
PMID: 29104494 DOI: 10.7150/ijbs.19531

Exosomes are 40- to 100-nm membrane-bound small vesicles that carry a great variety of cellular cargoes including proteins, DNA, messenger RNAs (mRNAs), and microRNAs (miRNAs). These nanovesicles are detected in various biological fluids such as serum, urine, saliva, and seminal fluids. Exosomes serve as key mediators in intercellular communication by facilitating the transfer and exchange of cellular components from cells to cells. They contain various pathogenic factors whereby their adverse effects have been implicated in multiple viral infections and cancers. Interestingly, accumulating evidences showed that exosomes derived from tumour viruses or oncoviruses, exacerbate virus-associated cancers by remodelling the tumour microenvironment. In this review, we summarize the contributing factors of Epstein-Barr virus (EBV) products-containing exosomes in viral pathogenesis and their potential implications in EBV-driven malignancies. Understanding the biological role of these exosomes in the disease would undoubtedly boost the development of a more comprehensive strategy to combat EBV-associated cancers and to better predict the therapeutic outcomes. Furthermore, we also highlight the potentials and challenges of EBV products-containing exosomes being employed as diagnostic markers and therapeutic targets for EBV-related cancers. Since these aspects are rather underexplored, we attempt to underline interesting areas that warrant further investigations in the future.
Fulltext Nutlin-3, A p53-Mdm2 antagonist for nasopharyngeal carcinoma treatment

Voon YL, Wong PF, Khoo ASB

Mini Rev Med Chem, 2018;18(2):173-183.
PMID: 28714398 DOI: 10.2174/1389557517666170717125821

Nasopharyngeal carcinoma (NPC) is a form of head and neck cancer of multifactorial etiologies that is highly prevalent among men in the population of Southern China and Southeast Asia. NPC has claimed many thousands of lives worldwide; but the low awareness of NPC remains a hindrance in early diagnosis and prevention of the disease. NPC is highly responsive to radiotherapy and chemotherapy, but radiocurable NPC is still dependent on concurrent treatment of megavoltage radiotherapy with chemotherapy. Despite a significant reduction in loco-regional and distant metastases, radiotherapy alone has failed to provide a significant improvement in the overall survival rate of NPC, compared to chemotherapy. In addition, chemo-resistance persists as the major challenge in the management of metastatic NPC although the survival rate of advanced metastatic NPC has significantly improved with the administration of chemotherapy adjunctive to radiotherapy. In this regard, targeted molecular therapy could be explored for the discovery of alternative NPC therapies. Nutlin-3, a small molecule inhibitor that specifically targets p53-Mdm2 interaction offers new therapeutic opportunities by enhancing cancer cell growth arrest and apoptosis through the restoration of the p53-mediated tumor suppression pathway while producing minimal cytotoxicity and side effects. This review discusses the potential use of Nutlin-3 as a p53-activating drug and the future directions of its clinical research for NPC treatment.
Fulltext Oxidative stress-induced chromosome breaks within the ABL gene: a model for chromosome rearrangement in nasopharyngeal carcinoma

Tan SN, Sim SP, Khoo AS

Hum Genomics, 2018 06 18;12(1):29.
PMID: 29914565 DOI: 10.1186/s40246-018-0160-8

BACKGROUND: The mechanism underlying chromosome rearrangement in nasopharyngeal carcinoma (NPC) remains elusive. It is known that most of the aetiological factors of NPC trigger oxidative stress. Oxidative stress is a potent apoptotic inducer. During apoptosis, chromatin cleavage and DNA fragmentation occur. However, cells may undergo DNA repair and survive apoptosis. Non-homologous end joining (NHEJ) pathway has been known as the primary DNA repair system in human cells. The NHEJ process may repair DNA ends without any homology, although region of microhomology (a few nucleotides) is usually utilised by this DNA repair system. Cells that evade apoptosis via erroneous DNA repair may carry chromosomal aberration. Apoptotic nuclease was found to be associated with nuclear matrix during apoptosis. Matrix association region/scaffold attachment region (MAR/SAR) is the binding site of the chromosomal DNA loop structure to the nuclear matrix. When apoptotic nuclease is associated with nuclear matrix during apoptosis, it potentially cleaves at MAR/SAR. Cells that survive apoptosis via compromised DNA repair may carry chromosome rearrangement contributing to NPC tumourigenesis. The Abelson murine leukaemia (ABL) gene at 9q34 was targeted in this study as 9q34 is a common region of loss in NPC. This study aimed to identify the chromosome breakages and/or rearrangements in the ABL gene in cells undergoing oxidative stress-induced apoptosis.
RESULTS: In the present study, in silico prediction of MAR/SAR was performed in the ABL gene. More than 80% of the predicted MAR/SAR sites are closely associated with previously reported patient breakpoint cluster regions (BCR). By using inverse polymerase chain reaction (IPCR), we demonstrated that hydrogen peroxide (H2O2)-induced apoptosis in normal nasopharyngeal epithelial and NPC cells led to chromosomal breakages within the ABL BCR that contains a MAR/SAR. Intriguingly, we detected two translocations in H2O2-treated cells. Region of microhomology was found at the translocation junctions. This observation is consistent with the operation of microhomology-mediated NHEJ.
CONCLUSIONS: Our findings suggested that oxidative stress-induced apoptosis may participate in chromosome rearrangements of NPC. A revised model for oxidative stress-induced apoptosis mediating chromosome rearrangement in NPC is proposed.
Fulltext Factor IX mutations in haemophilia B patients in Malaysia: a preliminary study

Balraj P, Ahmad M, Khoo AS, Ayob Y

Malays J Pathol, 2012 Jun;34(1):67-9.
PMID: 22870602 MyJurnal

Haemophilia B is caused by coagulation defects in the factor IX gene located in Xq27.1 on the X chromosome. Identification of mutations contributing to defective factor IX may be advantageous for precise carrier and prenatal diagnosis. We studied 16 patients from 11 families, consisting of 8 patients of the Malay ethnic group, of which 6 were siblings. Factor IX mutations have not been previously reported in the Malay ethnic group. The functional region of the factor IX gene was sequenced and mutations were identified in either the exon or intronic regions in 15 of the patients. One novel mutation, 6660_6664delTTCTT was identified in siblings with moderate form of haemophilia B. Mutations identified in our patients when linked with disease severity were similar to findings in other populations. In summary, this preliminary data will be used to build a Malaysian mutation database which would facilitate genetic counseling.
Fulltext Deregulation of lipid metabolism pathway genes in nasopharyngeal carcinoma cells

Daker M, Bhuvanendran S, Ahmad M, Takada K, Khoo AS

Mol Med Rep, 2013 Mar;7(3):731-41.
PMID: 23292678 DOI: 10.3892/mmr.2012.1253

Nasopharyngeal carcinoma (NPC) is a unique tumour of epithelial origin with a distinct geographical distribution, closely associated with the Epstein‑Barr virus (EBV). EBV‑encoded RNAs (EBERs) are small non‑polyadenylated RNAs that are abundantly expressed in latent EBV‑infected NPC cells. To study the role of EBERs in NPC, we established stable expression of EBERs in HK1, an EBV‑negative NPC cell line. Cells expressing EBERs consistently exhibited an increased growth rate. However, EBERs did not confer resistance towards cisplatin‑induced apoptosis or promote migration or invasion ability in the cells tested. Using microarray gene expression profiling, we identified potential candidate genes that were deregulated in NPC cells expressing EBERs. Gene Ontology analysis of the data set revealed that EBERs upregulate the cellular lipid metabolic process. Upregulation of low‑density lipoprotein receptor (LDLR) and fatty acid synthase (FASN) was observed in EBER‑expressing cells. NPC cells exhibited LDL‑dependent cell proliferation. In addition, a polyphenolic flavonoid compound, quercetin, known to inhibit FASN, was found to inhibit proliferation of NPC cells.
Fulltext Lack of Rb2/p130 genetic alteration in Malaysian nasopharyngeal carcinoma

Hoe SL, Lee ES, Khoo AS, Peh SC

Malays J Pathol, 2009 Jun;31(1):53-6.
PMID: 19694314 MyJurnal

The retinoblastoma-related gene Rb2/p130 has been reported to be mutated in several malignancies such as lung cancer and Burkitt's lymphoma. Nasopharyngeal carcinoma (NPC) is a common cancer in Malaysia especially amongst the ethnic Chinese. We screened for Rb2/p130 gene (exons 19 to 21) mutations in 53 archival NPC samples via PCR-SSCP-direct sequencing approach. Only one sample had a base change which involved a serine to glycine substitution at codon 995 (S995G). We conclude that Rb2/p130 genetic alterations are infrequent in NPC and may not be essential for the pathogenesis of the disease.
Fulltext Molecular analysis of 2009 pandemic influenza A(H1N1) in Malaysia associated with mild and severe infections

Balraj P, Sidek H, Suppiah J, Khoo AS, Saat Z

Malays J Pathol, 2011 Jun;33(1):7-12.
PMID: 21874745 MyJurnal

The 2009 pandemic influenza A(H1N1) was first detected in Malaysia in May 2009. It quickly spread in the general population and contributed to a number of influenza-like illness. The objective of the study is to characterize genetic changes in early Malaysian isolates of mild and severe illness of the novel influenza, and to compare sequences of viruses circulating in Malaysia to those in other countries between May to September 2009. Viral isolates of 56 mild cases and 10 severe (intensive care unit or fatal) cases were sequenced for haemagglutinin (HA) and neuraminidase (NA). Genome sequencing of the viral RNA was conducted on 5 isolates (3 were from fatal cases). Highly conserved sequences with few sporadic variations were identified in HA and NA. E374K and D222N were identified in 2 viral isolates from patients with severe illness. Phylogenetic analysis showed close genetic relatedness to the vaccine strain A/California/07/09 and other isolates circulating worldwide during the same period. Sporadic variations were identified in the viral isolates, however a larger sample size is required to make associations with disease severity.
Fulltext Exosomes in Human Immunodeficiency Virus Type I Pathogenesis: Threat or Opportunity?

Teow SY, Nordin AC, Ali SA, Khoo AS

Adv Virol, 2016;2016:9852494.
PMID: 26981123 DOI: 10.1155/2016/9852494

Nanometre-sized vesicles, also known as exosomes, are derived from endosomes of diverse cell types and present in multiple biological fluids. Depending on their cellular origins, the membrane-bound exosomes packed a variety of functional proteins and RNA species. These microvesicles are secreted into the extracellular space to facilitate intercellular communication. Collective findings demonstrated that exosomes from HIV-infected subjects share many commonalities with Human Immunodeficiency Virus Type I (HIV-1) particles in terms of proteomics and lipid profiles. These observations postulated that HIV-resembled exosomes may contribute to HIV pathogenesis. Interestingly, recent reports illustrated that exosomes from body fluids could inhibit HIV infection, which then bring up a new paradigm for HIV/AIDS therapy. Accumulative findings suggested that the cellular origin of exosomes may define their effects towards HIV-1. This review summarizes the two distinctive roles of exosomes in regulating HIV pathogenesis. We also highlighted several additional factors that govern the exosomal functions. Deeper understanding on how exosomes promote or abate HIV infection can significantly contribute to the development of new and potent antiviral therapeutic strategy and vaccine designs.
Fulltext Kisspeptin Activates Ankrd 26 Gene Expression in Migrating Embryonic GnRH Neurons

Soga T, Lim WL, Khoo AS, Parhar IS

Front Endocrinol (Lausanne), 2016;7:15.
PMID: 26973595 DOI: 10.3389/fendo.2016.00015

Kisspeptin, a newly discovered neuropeptide, regulates gonadotropin-releasing hormone (GnRH). Kisspeptins are a large RF-amide family of peptides. The kisspeptin coded by KiSS-1 gene is a 145-amino acid protein that is cleaved to C-terminal peptide kisspeptin-10. G-protein-coupled receptor 54 (GPR54) has been identified as a kisspeptin receptor, and it is expressed in GnRH neurons and in a variety of cancer cells. In this study, enhanced green fluorescent protein (EGFP) labeled GnRH cells with migratory properties, which express GPR54, served as a model to study the effects of kisspeptin on cell migration. We monitored EGFP-GnRH neuronal migration in brain slide culture of embryonic day 14 transgenic rat by live cell imaging system and studied the effects of kisspeptin-10 (1 nM) treatment for 36 h on GnRH migration. Furthermore, to determine kisspeptin-induced molecular pathways related with apoptosis and cytoskeletal changes during neuronal migration, we studied the expression levels of candidate genes in laser-captured EGFP-GnRH neurons by real-time PCR. We found that there was no change in the expression level of genes related to cell proliferation and apoptosis. The expression of ankyrin repeat domain-containing protein (ankrd) 26 in EGFP-GnRH neurons was upregulated by the exposure to kisspeptin. These studies suggest that ankrd 26 gene plays an unidentified role in regulating neuronal movement mediated by kisspeptin-GPR54 signaling, which could be a potential pathway to suppress cell migration.
Metabolic regulation of the tumour and its microenvironment: The role of Epstein-Barr virus

Lee SH, Khoo AS, Griffiths JR, Mat Lazim N

Int J Cancer, 2025 Feb 01;156(3):488-498.
PMID: 39291683 DOI: 10.1002/ijc.35192

The Epstein-Barr virus (EBV), the first identified human tumour virus, infects over 95% of the individuals globally and has the potential to induce different types of cancers. It is increasingly recognised that EBV infection not only alters cellular metabolism, contributing to neoplastic transformation, but also utilises several non-cell autonomous mechanisms to shape the metabolic milieu in the tumour microenvironment (TME) and its constituent stromal and immune cells. In this review, we explore how EBV modulates metabolism to shape the interactions between cancer cells, stromal cells, and immune cells within a hypoxic and acidic TME. We highlight how metabolites resulting from EBV infection act as paracrine factors to regulate the TME, and how targeting them can disrupt barriers to immunotherapy.
Antibacterial Action of Curcumin against Staphylococcus aureus: A Brief Review

Teow SY, Liew K, Ali SA, Khoo AS, Peh SC

J Trop Med, 2016;2016:2853045.
PMID: 27956904

Curcumin, the major constituent of Curcuma longa L. (Zingiberaceae family) or turmeric, commonly used for cooking in Asian cuisine, is known to possess a broad range of pharmacological properties at relatively nontoxic doses. Curcumin is found to be effective against Staphylococcus aureus (S. aureus). As demonstrated by in vitro experiment, curcumin exerts even more potent effects when used in combination with various other antibacterial agents. Hence, curcumin which is a natural product derived from plant is believed to have profound medicinal benefits and could be potentially developed into a naturally derived antibiotic in the future. However, there are several noteworthy challenges in the development of curcumin as a medicine. S. aureus infections, particularly those caused by the multidrug-resistant strains, have emerged as a global health issue and urgent action is needed. This review focuses on the antibacterial activities of curcumin against both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). We also attempt to highlight the potential challenges in the effort of developing curcumin into a therapeutic antibacterial agent.
Cytotoxic Activity of Boesenbergia rotunda Extracts against Nasopharyngeal Carcinoma Cells (HK1). Cardamonin, a Boesenbergia rotunda Constituent, Inhibits Growth and Migration of HK1 Cells by Inducing Caspase-Dependent Apoptosis and G2/M-Phase Arrest

Break MKB, Chiang M, Wiart C, Chin CF, Khoo ASB, Khoo TJ

Nutr Cancer, 2021;73(3):473-483.
PMID: 32270712 DOI: 10.1080/01635581.2020.1751217

Boesenbergia rotunda (L.) Mansf. is an edible herb that is commonly used in the cuisine of several Asian countries. Studies have shown that it possesses high bioactivity against a variety of cancer cells. In this study, we investigated the cytotoxic activity of Boesenbergia rotunda rhizomes and some of its constituents on nasopharyngeal carcinoma cells (HK1). MTT assay results showed that the methanolic and hexane extracts of Boesenbergia rotunda decreased HK1 cell viability with IC50 values of 136 µg/ml and 66 µg/ml, respectively. Cardamonin, a constituent of Boesenbergia rotunda, exhibited the highest cytotoxic activity with an IC50 value of 27 μg/ml. Further studies on cardamonin revealed that it inhibited the migration of HK1 cells, caused G2/M-phase arrest and induced apoptosis. Apoptosis was induced via activating caspase-8 and caspase-3, but independent of caspase-9. This indicated that cardamonin induced extrinsic apoptosis. Western blot analysis further showed that cardamonin caused extrinsic apoptosis, as the expression levels of intrinsic apoptosis-related proteins (Bcl-XL, Bcl-2 and Bax), were not affected. Finally, JC-1 staining of HK1 cells revealed an increase in the mitochondrial membrane potential after treatment, further proving that cardamonin did not induce apoptosis via the intrinsic pathway. These results reflect cardamonin's potential as an anticancer agent.
Fulltext Current Status and Future Perspectives about Molecular Biomarkers of Nasopharyngeal Carcinoma

Siak PY, Khoo AS, Leong CO, Hoh BP, Cheah SC

Cancers (Basel), 2021 Jul 12;13(14).
PMID: 34298701 DOI: 10.3390/cancers13143490

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy that shows a remarkable ethnic and geographical distribution. It is one of the major public health problems in some countries, especially Southern China and Southeast Asia, but rare in most Western countries. Multifactorial interactions such as Epstein-Barr virus infection, individual's genetic susceptibility, as well as environmental and dietary factors may facilitate the pathogenesis of this malignancy. Late presentation and the complex nature of the disease have led it to become a major cause of mortality. Therefore, an effective, sensitive, and specific molecular biomarker is urgently needed for early disease diagnosis, prognosis, and prediction of metastasis and recurrence after treatment. In this review, we discuss the recent research status of potential biomarker discovery and the problems that need to be explored further for better NPC management. By studying the aberrant pattern of these candidate biomarkers that promote NPC development and progression, we are able to understand the complexity of this malignancy better, hence positing our stands better towards strategies that may provide a way forward to the discovery of more reliable and specific biomarkers for diagnosis and targeted therapeutic development.
Fulltext Nasopharyngeal carcinoma among the Bidayuh of Sarawak, Malaysia: History and risk factors

Linton RE, Daker M, Khoo AS, Choo DCY, Viljoen M, Neilsen PM

Oncol Lett, 2021 Jul;22(1):514.
PMID: 33986874 DOI: 10.3892/ol.2021.12775

Nasopharyngeal carcinoma (NPC) is a cancer of the epithelial cells lining the nasopharynx. The incidence of NPC has a distinct geographical distribution, mainly affecting the Chinese population of Southern China. In Malaysia, this cancer is exceptionally prevalent among males. There is a high incidence rate of NPC among the Bidayuh natives in Sarawak, Malaysia. Other than epidemiology reports, there has not been an article describing plausible cancer risk factors contributing to NPC within this native group. Researchers are still trying to understand the reasons the Bidayuh and Southern Chinese are highly susceptible to NPC. This article discusses the risk factors of developing NPC: Epstein-Barr virus infection, genetic predisposition, diet, environmental exposure and tobacco smoking. There is a need to improve the understanding of the role of risk factors to identify new ways to prevent cancer, especially among high-risk groups.
Suppression of BCL-2 synergizes cisplatin sensitivity in nasopharyngeal carcinoma cells

Low SY, Tan BS, Choo HL, Tiong KH, Khoo AS, Leong CO

Cancer Lett, 2012 Jan 28;314(2):166-75.
PMID: 22033244 DOI: 10.1016/j.canlet.2011.09.025

The efficacy of cisplatin for treating nasopharyngeal carcinoma (NPC) is limited by the dose-related toxicities and the development of resistance to cisplatin. Recent studies have shown that B cell lymphoma-2 (BCL-2) is overexpressed and confers chemoresistance in NPC. Thus, targeted therapy against BCL-2 may enhance the antitumour effects of chemotherapy by sensitizing the tumor cells to undergo apoptosis. This study evaluated the combined effects of BCL-2 inhibition and cisplatin in NPC cells. Our results demonstrate that inhibition of BCL-2 by small-hairpin RNA (shRNA) or the BCL-2 inhibitor YC137, synergizes cisplatin sensitivity in NPC cells that overexpress BCL-2. We also show that YC137 enhance cisplatin-induced apoptosis in HK1 and CNE1 cells through suppression of BCL-2 protein expression, induction of mitochondrial depolarization and activation of caspase 9 and caspase 3/7. These findings suggest that the combination of BCL-2 inhibition and cisplatin represents a promising strategy for treating NPC.
Fulltext Expression trend of selected ribosomal protein genes in nasopharyngeal carcinoma

Ma XR, Sim EU, Ling TY, Tiong TS, Subramaniam SK, Khoo AS

Malays J Med Sci, 2012 Oct;19(4):23-30.
PMID: 23613646 MyJurnal

Ribosomal proteins are traditionally associated with protein biosynthesis until recent studies that implicated their extraribosomal functions in human diseases and cancers. Our previous studies using GeneFishing™ DEG method and microarray revealed underexpression of three ribosomal protein genes, RPS26, RPS27, and RPL32 in cancer of the nasopharynx. Herein, we investigated the expression pattern and nucleotide sequence integrity of these genes in nasopharyngeal carcinoma to further delineate their involvement in tumourigenesis. The relationship of expression level with clinicopathologic factors was also statistically studied.
Fulltext Gonadotropin‑releasing hormone inhibits the proliferation and motility of nasopharyngeal carcinoma cells

Teng LH, Ahmad M, Ng WT, Sabaratnam S, Rasan MI, Parhar I, et al.

Mol Med Rep, 2015 Oct;12(4):4909-16.
PMID: 26151677 DOI: 10.3892/mmr.2015.4043

Gonadotropin‑releasing hormone (GnRH), or its analogues have been demonstrated to exhibit anti‑proliferative effects on tumour cells in ovarian, endometrial and breast cancer through GnRH‑receptors (GnRH‑R). However, the role of GnRH in nasopharyngeal carcinoma (NPC) remains to be elucidated. In order to investigate the effects of GnRH in NPC, the present study examined the expression of the GnRH‑R transcript in NPC and investigated the phenotypic changes in HK1 cells, a recurrent NPC‑derived cell line, upon receiving GnRH treatment. Firstly, the GnRH‑R transcript was demonstrated in the NPC cell lines and four snap frozen biopsies using reverse transcription‑quantitative polymerase chain reaction. In addition, immunohistochemistry revealed the expression of GnRH‑R in two of the eight (25%) NPC specimens. Treatment with GnRH induced a rapid increase in intracellular ionised calcium concentration in the NPC cells. GnRH and its agonists, triptorelin and leuprolide, exerted anti‑proliferative effects on the NPC cells, as determined using an MTS assay. GnRH did not induce any cell cycle arrest in the HK1 cells under the conditions assessed in the present study. Time‑lapse imaging demonstrated a reduction in cell motility in the GnRH‑treated cells. In conclusion, GnRH, or its analogues may have antitumour effects on NPC cells. The consequences of alterations in the levels of GnRH on the progression of NPC require further examination.
Selective anticancer copper(II)-mixed ligand complexes: targeting of ROS and proteasomes

Ng CH, Kong SM, Tiong YL, Maah MJ, Sukram N, Ahmad M, et al.

Metallomics, 2014 Apr;6(4):892-906.
PMID: 24549332 DOI: 10.1039/c3mt00276d

Copper compounds can be alternatives to platinum-based anticancer drugs. This study investigated the effects of a series of ternary copper(II) complexes, [Cu(phen)(aa)(H2O)]NO3·xH2O 1-4 (phen = 1,10-phenanthroline; aa = gly (1), DL-ala (2), sar (3), C-dmg (4)), on metastatic and cisplatin-resistant MDA-MB-231 breast cancer cells and MCF10A non-cancerous breast cells, and some aspects of the mechanisms. These complexes were distinctively more antiproliferative towards and induced greater apoptotic cell death in MDA-MB-231 than in MCF10A cells. 2 and 4 could induce cell cycle arrest only in cancer cells. Further evidence from DCFH-DA assay showed higher induction of reactive oxygen species (ROS) in treated cancer cells but minimal ROS increase in normal cells. DNA double-strand breaks, via a γ-H2AX assay, were only detected in cancer cells treated with 5 μM of the complexes. These complexes poorly inhibited chymotrypsin-like activity in the 20S rabbit proteasome while they did not inhibit the three proteolytic sites of MDA-MB-231 cells at 10 μM. However, the complexes could inhibit degradation of ubiquinated proteins of MDA-MB-231 cells. In addition, compound 4 was found to be effective against cervical (Hela), ovarian (SKOV3), lung (A549, PC9), NPC (Hone1, HK1, C666-1), breast (MCF7, T47D), lymphoma and leukemia (Nalmawa, HL60) and colorectal (SW480, SW48, HCT118) cancer cell lines with IC50 values (24 h) in the 1.7-19.0 μM range. Single dose NCI60 screening of 4 showed the complex to be highly cytotoxic to most cancer cell types and more effective than cisplatin.

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