Publications by authors named "Suet Lin Chia"

19 Publications

  • Page 1 of 1

Inhibition of Autophagy Does Not Affect Innate Cytokine Production in Human Lung Epithelial Cells During Respiratory Syncytial Virus Infection.

Viral Immunol 2021 Apr 9. Epub 2021 Apr 9.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Malaysia.

Human respiratory syncytial virus (RSV) is one of the major causes of childhood acute lower respiratory tract infection worldwide. Autophagy is an intracellular pathway involved in nutrient recycling. Recently, autophagy has been reported to play a role in regulating host cytokine response to several viruses, including vesicular stomatitis virus and human immunodeficiency virus. Previous studies using mouse model has shown that inhibition of autophagy reduces RSV-induced cytokine production. However, the role of autophagy in modulating RSV-induced cytokine response in human cells has not been reported. We investigated the role of autophagy in regulating the production of the cytokines C-X-C motif ligand 8 (CXCL8) and C-C motif ligand 5 (CCL5), in RSV-infected human bronchial epithelium BEAS-2B cells. Fluorescent microscopic analysis showed that RSV infection induced autophagosome formation in BEAS-2B cells. This autophagy inducing ability of RSV was further confirmed by flow cytometry. The effects of pharmacological inhibition of autophagy by SAR405 or chloroquine on cell death and cytokine release were quantified using lactate dehydrogenase assay and enzyme-linked immunosorbent assay (ELISA), respectively. We found that SAR405 or chloroquine did not cause cell death. Importantly, ELISA analysis showed that pharmacological inhibition of autophagy by SAR405 or chloroquine did not affect the productions of both CXCL5 and CXCL8. In contrast to the previous studies using mouse model, our data suggest that pharmacological inhibition of autophagy may not be a suitable strategy in controlling RSV-induced airway inflammation.
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http://dx.doi.org/10.1089/vim.2020.0217DOI Listing
April 2021

Development of a T7 RNA polymerase expressing cell line using lentivirus vectors for the recovery of recombinant Newcastle disease virus.

J Virol Methods 2021 05 13;291:114099. Epub 2021 Feb 13.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia; UPM-MAKNA Cancer Research Laboratory, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia. Electronic address:

The development of a T7 RNA polymerase (T7 RNAP) expressing cell line i.e. BSR T7/5 cells marks an improvement of reverse genetics for the recovery of recombinant Newcastle disease virus (rNDV). BSR T7/5 is developed by transient transfection of plasmid encoding T7 RNAP gene for rNDV rescue. However, the gene expression decreases gradually over multiple passages and eventually hinders the rescue of rNDV. To address this issue, lentiviral vector was used to develop T7 RNAP-expressing HEK293-TA (HEK293-TA-Lv-T7) and SW620 (SW620-Lv-T7) cell lines, evidenced by the expression of T7 RNAP after subsequent 20 passages. rNDV was rescued successfully using HEK293-TA-Lv-T7 clones (R1D3, R1D8, R5B9) and SW620-Lv-T7 clones (R1C11, R3C5) by reverse transfection, yielding comparable virus rescue efficiency and virus titres to that of BSR T7/5. This study provides new tools for rNDV rescue and insights into cell line development and virology by reverse genetics.
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http://dx.doi.org/10.1016/j.jviromet.2021.114099DOI Listing
May 2021

Synthesis and Optimization of Mesoporous Silica Nanoparticles for Ruthenium Polypyridyl Drug Delivery.

Pharmaceutics 2021 Jan 24;13(2). Epub 2021 Jan 24.

Department of Chemistry, Swansea University, Swansea SA2 8PP, UK.

The ruthenium polypyridyl complex [Ru(dppz)PIP] (dppz: dipyridophenazine, PIP: (2-(phenyl)-imidazo[4,5-f ][1,10]phenanthroline), or Ru-PIP, is a potential anticancer drug that acts by inhibiting DNA replication. Due to the poor dissolution of Ru-PIP in aqueous media, a drug delivery agent would be a useful approach to overcome its limited bioavailability. Mesoporous silica nanoparticles (MSNs) were synthesized via a co-condensation method by using a phenanthrolinium salt with a 16 carbon length chain (Phen-C) as the template. Optimization of the synthesis conditions by Box-Behnken design (BBD) generated MSNs with high surface area response at 833.9 mg. Ru-PIP was effectively entrapped in MSNs at 18.84%. Drug release profile analysis showed that Ru-PIP is gradually released, with a cumulative release percentage of approximately 50% at 72 h. The release kinetic profile implied that Ru-PIP was released from MSN by diffusion. The in vitro cytotoxicity of Ru-PIP, both free and MSN-encapsulated, was studied in Hela, A549, and T24 cancer cell lines. While treatment of Ru-PIP alone is moderately cytotoxic, encapsulated Ru-PIP exerted significant cytotoxicity upon all the cell lines, with half maximal inhibitory concentration (IC) values determined by MTT (([3-(4,5-dimethylthiazol-2-yl)-2,5-dephenyltetrazolium bromide]) assay at 48 h exposure substantially decreasing from >30 µM to <10 µM as a result of MSN encapsulation. The mechanistic potential of cytotoxicity on cell cycle distribution showed an increase in G1/S phase populations in all three cell lines. The findings indicate that MSN is an ideal drug delivery agent, as it is able to sustainably release Ru-PIP by diffusion in a prolonged treatment period.
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http://dx.doi.org/10.3390/pharmaceutics13020150DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7910993PMC
January 2021

Oncolytic effects of the recombinant Newcastle disease virus, rAF-IL12, against colon cancer cells in vitro and in tumor-challenged NCr-Foxn1nu nude mice.

PeerJ 2020 8;8:e9761. Epub 2020 Dec 8.

Universiti Putra Malaysia, Serdang, Malaysia.

Colon cancer remains one of the main cancers causing death in men and women worldwide as certain colon cancer subtypes are resistant to conventional treatments and the development of new cancer therapies remains elusive. Alternative modalities such as the use of viral-based therapeutic cancer vaccine is still limited, with only the herpes simplex virus (HSV) expressing granulocyte-macrophage colony- stimulating factor (GM-CSF) or talimogene laherparepvec (T-Vec) being approved in the USA and Europe so far. Therefore, it is imperative to continue the search for a new treatment modality. This current study evaluates a combinatorial therapy between the oncolytic Newcastle disease virus (NDV) and interleukin-12 (IL-12) cytokine as a potential therapeutic vaccine to the current anti-cancer drugs. Several in vitro analyses such as MTT assay, Annexin V/FITC flow cytometry, and cell cycle assay were performed to evaluate the cytotoxicity effect of recombinant NDV, rAF-IL12. Meanwhile, serum cytokine, serum biochemical, histopathology of organs and TUNEL assay were carried out to assess the anti-tumoral effects of rAF-IL12 in HT29 tumor-challenged nude mice. The apoptosis mechanism underlying the effect of rAF-IL12 treatment was also investigated using NanoString Gene expression analysis. The recombinant NDV, rAF-IL12 replicated in HT29 colon cancer cells as did its parental virus, AF2240-i. The rAF-IL12 treatment had slightly better cytotoxicity effects towards HT29 cancer cells when compared to the AF2240-i as revealed by the MTT, Annexin V FITC and cell cycle assay. Meanwhile, the 28-day treatment with rAF-IL12 had significantly ( < 0.05) perturbed the growth and progression of HT29 tumor in NCr-Foxn1nu nude mice when compared to the untreated and parental wild-type NDV strain AF2240-i. The rAF-IL12 also modulated the immune system in nude mice by significantly ( < 0.05) increased the level of IL-2, IL-12, and IFN-γ cytokines. Treatment with rAF-IL12 had also significantly ( < 0.05) increased the expression level of apoptosis-related genes such as Fas, caspase-8, BID, BAX, Smad3 and granzyme B in vitro and in vivo. Besides, rAF-IL12 intra-tumoral delivery was considered safe and was not hazardous to the host as evidenced in pathophysiology of the normal tissues and organs of the mice as well as from the serum biochemistry profile of liver and kidney. Therefore, this study proves that rAF-IL12 had better cytotoxicity effects than its parental AF2240-i and could potentially be an ideal treatment for colon cancer in the near future.
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http://dx.doi.org/10.7717/peerj.9761DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7731658PMC
December 2020

In-Vitro and In-Silico Evaluations of Heterocyclic-Containing Diarylpentanoids as Bcl-2 Inhibitors Against LoVo Colorectal Cancer Cells.

Molecules 2020 Aug 26;25(17). Epub 2020 Aug 26.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, UPM Serdang 43400, Selangor Darul Ehsan, Malaysia.

In the present study, we investigated the in-vitro anti-cancer potential of six diarylpentanoids against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, SW620, LoVo, HT29, NCI-H508, RKO, and LS411N cells. Structure-activity relationship study suggested that the insertions of tetrahydro-4-thiopyran-4-one and brominated phenyl moieties are essential for better cytotoxicity. Among the evaluated analogs, has been identified as the lead compound due to its low IC values of approximately 1 µM across all cancer cell lines and high chemotherapeutic index of 7.1. Anti-proliferative studies on LoVo cells showed that could inhibit cell proliferation and colony formations by inducing G2/M cell cycle arrest. Subsequent cell apoptosis assay confirmed that is a Bcl-2 inhibitor that could induce intrinsic cell apoptosis by creating a cellular redox imbalance through its direct inhibition on the Bcl-2 protein. Further molecular docking studies revealed that the bromophenyl moieties of could interact with the Bcl-2 surface pocket through hydrophobic interaction, while the tetrahydro-4-thiopyran-4-one fragment could form additional Pi-sulfur and Pi-alkyl interactions in the same binding site. In all, the present results suggest that could be a potent lead that deserves further modification and investigation in the development of a new Bcl-2 inhibitor.
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http://dx.doi.org/10.3390/molecules25173877DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7504466PMC
August 2020

Cytotoxicity study of the interleukin-12-expressing recombinant Newcastle disease virus strain, rAF-IL12, towards CT26 colon cancer cells in vitro and in vivo.

Cancer Cell Int 2020 29;20:278. Epub 2020 Jun 29.

Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan 43400 Malaysia.

Background: Oncolytic viruses have emerged as an alternative therapeutic modality for cancer as they can replicate specifically in tumour cells and induce toxic effects leading to apoptosis. Despite the great potentials and promising results shown in multiple studies, it appears that their efficacy is still moderate and deemed as not sufficient in clinical studies. In addressing this issue, genetic/molecular engineering approach has paved its way to improve the therapeutic efficacy as observed in the case of herpes simplex virus (HSV) expressing granulocyte-macrophage colony-stimulating factor (GM-CSF). This study aimed to explore the cytotoxicity effects of recombinant NDV strain AF2240-i expressing interleukin-12 (rAF-IL12) against CT26 colon cancer cells.

Methods: The cytotoxicity effect of rAF-IL12 against CT26 colon cancer cell line was determined by MTT assay. Based on the IC value from the anti-proliferative assay, further downward assays such as Annexin V FITC and cell cycle progression were carried out and measured by flow cytometry. Then, the in vivo study was conducted where the rAF-IL12 viral injections were given at the intra-tumoral site of the CT26 tumour-burden mice. At the end of the experiment, serum biochemical, T cell immunophenotyping, serum cytokine, histopathology of tumour and organ section, TUNEL assay, and Nanostring gene expression analysis were performed.

Results: The rAF-IL12 induced apoptosis of CT26 colon cancer cells in vitro as revealed in the Annexin V FITC analysis and also arrested the cancer cells progression at G phase of the cell cycle analysis. On the other hand, the rAF-IL12 significantly (p < 0.05) inhibited the growth of CT26 tumour in Balb/c mice and had regulated the immune system by increasing the level of CD4 + , CD8 + , IL-2, IL-12, and IFN-γ. Furthermore, the expression level of apoptosis-related genes (bax and p53) was up-regulated as a result of the rAF-IL12 treatment. Additionally, the rAF-IL12 had also down-regulated the expression level of KRAS, BRAF, MAPK1, Notch1, CCL2, and VEGF oncogenes. Besides, rAF-IL12 intra-tumoral delivery was considered safe and not hazardous to the host as evidenced in pathophysiology of the normal tissues and organs of the mice as well as from the serum biochemistry profile of liver and kidney.

Conclusions: These results indicated that rAF-IL12 had better anti-tumoral and cytotoxicity effects compared to its parental wild-type, AF2240-i in combatting the CT26 colon cancer model.
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http://dx.doi.org/10.1186/s12935-020-01372-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7325054PMC
June 2020

Synthesis and in-vitro anti-cancer evaluations of multi-methoxylated asymmetrical diarylpentanoids as intrinsic apoptosis inducer against colorectal cancer.

Bioorg Med Chem Lett 2020 04 26;30(8):127065. Epub 2020 Feb 26.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia; Malaysia Genome Institute (MGI), National Institute of Biotechnology Malaysia (NIBM), Jalan Bangi, 43000 Kajang, Selangor Darul Ehsan, Malaysia.

In the present study, a series of nine stable 3,4,5-methoxylphenyl-containing asymmetrical diarylpentanoids, derivatives of curcuminoids, have been synthesized, characterized and evaluated for their in-vitro anti-cancer potential against a panel of BRAF- and KRAS-mutated colorectal cancer cell lines including T84, LoVo and SW620, HT29, RKO and NCI-H508, respectively. Structure-activity relationship study on cytotoxicity of tested compounds suggested that the presence of meta-hydroxyl and adjacent dimethoxyl groups are crucial for enhanced cytotoxicity of diarylpentanoids. Among the evaluated analogs, 8 has been identified as the lead compound due to its highest chemotherapeutic index of 9.9 and nano molar scale cytotoxicity against SW620 and RKO. Colonies formation and cell cycle analyses on 8-treated RKO cells showed that 8 exhibits strong anti-proliferative activity by inducing G2/M-phase cell arrest. Subsequent flow cytometry based annexin-V and DCFHDA studies suggested that 8 could induce apoptosis through intracellular ROS-dependent pathway. Further Western blot studies confirmed that 8 has induced intrinsic apoptosis in RKO cells through the up-regulations of Bad and Bax pro-apoptotic proteins and down-regulations of Bcl-2 and Bcl-xL pro-survival proteins. In all, the present results suggest that 8 could be a potent lead which deserves further modification and investigation in the development of small molecule-based anti-colorectal cancer agents.
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http://dx.doi.org/10.1016/j.bmcl.2020.127065DOI Listing
April 2020

An improved method for the rescue of recombinant Newcastle disease virus.

Biotechniques 2020 02 15;68(2):96-100. Epub 2020 Jan 15.

Department of Microbiology, Faculty of Biotechnology & Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.

Reverse genetics has been used to generate recombinant Newcastle disease virus with enhanced immunogenic properties for vaccine development. The system, which involves co-transfecting the viral antigenomic plasmid with three helper plasmids into a T7 RNA polymerase-expressing cell to produce viral progenies, poses a great challenge. We have modified the standard transfection method to improve the transfection efficiency of the plasmids, resulting in a higher titer of virus progeny production. Two transfection reagents (i.e., lipofectamine and polyethylenimine) were used to compare the transfection efficiency of the four plasmids. The virus progenies produced were quantitated with flow cytometry analysis of the infectious virus unit. The modified transfection method increased the titer of virus progenies compared with that of the standard transfection method.
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http://dx.doi.org/10.2144/btn-2019-0110DOI Listing
February 2020

Metallointercalator [Ru(dppz)(PIP)] Renders BRCA Wild-Type Triple-Negative Breast Cancer Cells Hypersensitive to PARP Inhibition.

ACS Chem Biol 2020 02 14;15(2):378-387. Epub 2020 Jan 14.

Department of Chemistry, Faculty of Science , Universiti Putra Malaysia , 43400 UPM Serdang , Selangor , Malaysia.

There is a need to improve and extend the use of clinically approved poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi), including for BRCA wild-type triple-negative breast cancer (TNBC). The demonstration that ruthenium(II) polypyridyl complex (RPC) metallointercalators can rapidly stall DNA replication fork progression provides the rationale for their combination alongside DNA damage response (DDR) inhibitors to achieve synergism in cancer cells. The aim of the present study was to evaluate use of the multi-intercalator [Ru(dppz)(PIP)] (dppz = dipyrido[3,2-:2',3'-]phenazine, PIP = (2-(phenyl)imidazo[4,5-][1,10]phenanthroline, Ru-PIP) alongside the PARPi olaparib and NU1025. Cell proliferation and clonogenic survival assays indicated a synergistic relationship between Ru-PIP and olaparib in MDA-MB-231 TNBC and MCF7 human breast cancer cells. Strikingly, low dose Ru-PIP renders both cell lines hypersensitive to olaparib, with a >300-fold increase in olaparib potency in TNBC, the largest nongenetic PARPi enhancement effect described to date. A negligible impact on the viability of normal human fibroblasts was observed for any combination tested. Increased levels of DNA double-strand break (DSB) damage and olaparib abrogation of Ru-PIP-activated pChk1 signaling are consistent with PARPi-facilitated collapse of Ru-PIP-associated stalled replication forks. This results in enhanced G2/M cell-cycle arrest, apoptosis, and decreased cell motility for the combination treatment compared to single-agent conditions. This work establishes that an RPC metallointercalator can be combined with PARPi for potent synergy in BRCA-proficient breast cancer cells, including TNBC.
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http://dx.doi.org/10.1021/acschembio.9b00843DOI Listing
February 2020

Evaluation of a Recombinant Newcastle Disease Virus Expressing Human IL12 against Human Breast Cancer.

Sci Rep 2019 Sep 30;9(1):13999. Epub 2019 Sep 30.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor Darul Ehsan, Malaysia.

The Newcastle disease virus (NDV) strain AF2240 is an avian avulavirus that has been demonstrated to possess oncolytic activity against cancer cells. However, to illicit a greater anti-cancer immune response, it is believed that the incorporation of immunostimulatory genes such as IL12 into a recombinant NDV backbone will enhance its oncolytic effect. In this study, a newly developed recombinant NDV that expresses IL12 (rAF-IL12) was tested for its safety, stability and cytotoxicity. The stability of rAF-IL12 was maintained when passaged in specific pathogen free (SPF) chicken eggs from passage 1 to passage 10; with an HA titer of 2. Based on the results obtained from the MTT cytotoxic assay, rAF-IL12 was determined to be safe as it only induced cytotoxic effects against normal chicken cell lines and human breast cancer cells while sparing normal cells. Significant tumor growth inhibition (52%) was observed in the rAF-IL12-treated mice. The in vivo safety profile of rAF-IL12 was confirmed through histological observation and viral load titer assay. The concentration and presence of the expressed IL12 was quantified and verified via ELISA assay. In summary, rAF-IL12 was proven to be safe, selectively replicating in chicken and cancer cells and was able to maintain its stability throughout several passages; thus enhancing its potential as an anti-breast cancer vaccine.
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http://dx.doi.org/10.1038/s41598-019-50222-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6768883PMC
September 2019

Virotherapy: Current Trends and Future Prospects for Treatment of Colon and Rectal Malignancies.

Cancer Invest 2019 10;37(8):393-414. Epub 2019 Sep 10.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universit Putra Malaysia , Serdang , Malaysia.

Colorectal cancer (CRC) is one of the most common malignancies. In recent decades, early diagnosis and conventional therapies have resulted in a significant reduction in mortality. However, late stage metastatic disease still has very limited effective treatment options. There is a growing interest in using viruses to help target therapies to tumour sites. In recent years the evolution of immunotherapy has emphasised the importance of directing the immune system to eliminate tumour cells; we aim to give a state-of-the-art over-view of the diverse viruses that have been investigated as potential oncolytic agents for the treatment of CRC.
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http://dx.doi.org/10.1080/07357907.2019.1660887DOI Listing
October 2019

Turning cold tumours hot: oncolytic virotherapy gets up close and personal with other therapeutics at the 11th Oncolytic Virus Conference.

Cancer Gene Ther 2019 03 4;26(3-4):59-73. Epub 2018 Sep 4.

Department of Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK.

The 11th International Oncolytic Virus Conference (IOVC) was held from April 9-12, 2018 in Oxford, UK. This is part of the high-profile academic-led series of meetings that was started back in 2002 by Steve Russell and John Bell, with most of the previous meetings being held in North America (often in Banff). The conference brought together many of the major players in oncolytic virotherapy from all over the world, addressing all stages of research and development-from aspects of basic science and cellular immunology all the way through to early- and late-phase clinical trials. The meeting welcomed 352 delegates from 24 countries. The top seven delegate countries, namely, the UK, US, Canada, The Netherlands, Germany, Japan and South Korea, contributed 291 delegates while smaller numbers coming from Australia, Austria, Bulgaria, China, Finland, France, Iraq, Ireland, Israel, Italy, Latvia, Malaysia, Poland, Slovenia, Spain, Sweden and Switzerland. Academics comprised about half of the attendees, industry 30% and students 20%. The next IOVC is scheduled to be held on Vancouver Island in autumn 2019. Here we share brief summaries of the oral presentations from invited speakers and proffered papers in the different subtopics presented at IOVC 2018.
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http://dx.doi.org/10.1038/s41417-018-0042-1DOI Listing
March 2019

Asymmetrical meta-methoxylated diarylpentanoids: Rational design, synthesis and anti-cancer evaluation in-vitro.

Eur J Med Chem 2018 Sep 16;157:716-728. Epub 2018 Aug 16.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor Darul Ehsan, Malaysia; Malaysia Genome Institute (MGI), National Institute of Biotechnology Malaysia (NIBM), Jalan Bangi, 43000 Kajang, Selangor Darul Ehsan, Malaysia. Electronic address:

In the present study, a series of forty-five asymmetrical meta-methoxylated diarylpentanoids have been synthesized, characterized and evaluated for their in-vitro anti-cancer potential. Among the forty-five analogs, three compounds (20, 33 and 42) have been identified as lead compounds due to their excellent inhibition against five human cancer cell lines including SW620, A549, EJ28, HT1080 and MCF-7. Structure-activity relationship study on cytotoxicity of tested compounds suggested that the presence of meta-oxygenated phenyl ring played a critical role in enhancing their cytotoxic effects. Compounds 33 and 42 in particular, exhibited strongest cytotoxicity against tested cell lines with the IC values ranging from 1.1 to 4.3 μM. Subsequent colony formation assay on SW620 cell line showed that both compounds 33 and 42 possessed strong anti-proliferative activity. In addition, flow cytometry based experiments revealed that these compounds could trigger intracellular ROS production thus inducing G2/M-phase cell arrest and apoptosis. All these results suggested that poly meta-oxygenated diarylpentnoid is a promising scaffold which deserved further modification and investigation in the development of natural product-based anti-cancer drug.
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http://dx.doi.org/10.1016/j.ejmech.2018.08.039DOI Listing
September 2018

Newcastle disease virus strain AF2240 as an oncolytic virus: A review.

Acta Trop 2018 Jul 4;183:126-133. Epub 2018 Apr 4.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor D.E., Malaysia; Malaysian Genome Institute, Jalan Bangi, 43000 Kajang, Selangor D.E., Malaysia; Institute of Bioscience, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor D.E., Malaysia. Electronic address:

The discovery of tumour selective virus-mediated apoptosis marked the birth of an alternative cancer treatment in the form of oncolytic viruses. Even though, its oncolytic efficiency was demonstrated more than 50 years ago, safety concerns which resulted from mild to lethal side effects hampered the progress of oncolytic virus research. Since the classical oncolytic virus studies rely heavily on its natural oncolytic ability, virus manipulation was limited, thereby, restricted efforts to improve its safety. In order to circumvent such restriction, experiments involving non-human viruses such as the avian Newcastle disease virus (NDV) was conducted using cultured cells, animal models and human subjects. The corresponding reports on its significant tumour cytotoxicity along with impressive safety profile initiated immense research interest in the field of oncolytic NDV. The varying degree of oncolytic efficiency and virulency among NDV strains encouraged researchers from all around the world to experiment with their respective local NDV isolates in order to develop an oncolytic virus with desirable characteristics. Such desirable features include high tumour-killing ability, selectivity and low systemic cytotoxicity. The Malaysian field outbreak isolate, NDV strain AF2240, also currently, receives significant research attention. Apart from its high cytotoxicity against tumour cells, this strain also provided fundamental insight into NDV-mediated apoptosis mechanism which involves Bax protein recruitment as well as death receptor engagement. Studies on its ability to selectively induce apoptosis in tumour cells also resulted in a proposed p38 MAPK/NF-κB/IκBα pathway. The immunogenicity of AF2240 was also investigated through PBMC stimulation and macrophage infection. In addition, the enhanced oncolytic ability of this strain under hypoxic condition signifies its dynamic tumour tropism. This review is aimed to introduce and discuss the aforementioned details of the oncolytic AF2240 strain along with its current challenges which outlines the future research direction of this virus.
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http://dx.doi.org/10.1016/j.actatropica.2018.04.007DOI Listing
July 2018

Oncolytic Group B Adenovirus Enadenotucirev Mediates Non-apoptotic Cell Death with Membrane Disruption and Release of Inflammatory Mediators.

Mol Ther Oncolytics 2017 Mar 10;4:18-30. Epub 2016 Dec 10.

Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK.

Enadenotucirev (EnAd) is a chimeric group B adenovirus isolated by bioselection from a library of adenovirus serotypes. It replicates selectively in and kills a diverse range of carcinoma cells, shows effective anticancer activity in preclinical systems, and is currently undergoing phase I/II clinical trials. EnAd kills cells more quickly than type 5 adenovirus, and speed of cytotoxicity is dose dependent. The EnAd death pathway does not involve p53, is predominantly caspase independent, and appears to involve a rapid fall in cellular ATP. Infected cells show early loss of membrane integrity; increased exposure of calreticulin; extracellular release of ATP, HSP70, and HMGB1; and influx of calcium. The virus also causes an obvious single membrane blister reminiscent of ischemic cell death by oncosis. In human tumor biopsies maintained in ex vivo culture, EnAd mediated release of pro-inflammatory mediators such as TNF-α, IL-6, and HMGB1. In accordance with this, EnAd-infected tumor cells showed potent stimulation of dendritic cells and CD4 T cells in a mixed tumor-leukocyte reaction in vitro. Whereas many viruses have evolved for efficient propagation with minimal inflammation, bioselection of EnAd for rapid killing has yielded a virus with a short life cycle that combines potent cytotoxicity with a proinflammatory mechanism of cell death.
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http://dx.doi.org/10.1016/j.omto.2016.11.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5363721PMC
March 2017

Group B adenovirus enadenotucirev infects polarised colorectal cancer cells efficiently from the basolateral surface expected to be encountered during intravenous delivery to treat disseminated cancer.

Virology 2017 05 3;505:162-171. Epub 2017 Mar 3.

Department of Oncology, University of Oxford, Oxford, United Kingdom. Electronic address:

Enadenotucirev (EnAd) is a group B oncolytic adenovirus developed for systemic delivery and currently undergoing clinical evaluation for advanced cancer therapy. For differentiated carcinomas, systemic delivery would likely expose virus particles to the basolateral surface of cancer cells rather than the apical surface encountered during natural infection. Here, we compare the ability of EnAd and adenovirus type-5 (Ad5) to infect polarised colorectal carcinoma cells from the apical or basolateral surfaces. Whereas Ad5 infection was more efficient via the apical than basolateral surface, EnAd readily infected cells from either surface. Progeny particles from EnAd were released preferentially via the apical surface for all cell lines and routes of infection. These data further support the utility of group B adenoviruses for systemic delivery and suggest that progeny virus are more likely to be released into the tumour rather than back through the basolateral surface into the blood stream.
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http://dx.doi.org/10.1016/j.virol.2017.02.011DOI Listing
May 2017

Surface display of glycosylated Tyrosinase related protein-2 (TRP-2) tumour antigen on Lactococcus lactis.

BMC Biotechnol 2015 Dec 29;15:113. Epub 2015 Dec 29.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor Darul Ehsan, Malaysia.

Background: The exploitation of the surface display system of food and commensal lactic acid bacteria (LAB) for bacterial, viral, or protozoan antigen delivery has received strong interest recently. The Generally Regarded as Safe (GRAS) status of the Lactococcus lactis coupled with a non-recombinant strategy of in-trans surface display, provide a safe platform for therapeutic drug and vaccine development. However, production of therapeutic proteins fused with cell-wall anchoring motifs is predominantly limited to prokaryotic expression systems. This presents a major disadvantage in the surface display system particularly when glycosylation has been recently identified to significantly enhance epitope presentation. In this study, the glycosylated murine Tyrosinase related protein-2 (TRP-2) with the ability to anchor onto the L. lactis cell wall was produced in suspension adapted Chinese Hamster Ovary (CHO-S) cells by expressing TRP-2 fused with cell wall anchoring LysM motif (cA) at the C-terminus.

Results: A total amount of 33 μg of partially purified TRP-2-cA from ~6.0 g in wet weight of CHO-S cells was purified by His-tag affinity chromatography. The purified TRP-2-cA protein was shown to be N-glycosylated and successfully anchored to the L. lactis cell wall.

Conclusions: Thus cell surface presentation of glycosylated mammalian antigens may now permit development of novel and inexpensive vaccine platforms.
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http://dx.doi.org/10.1186/s12896-015-0231-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4696278PMC
December 2015

Viral persistence in colorectal cancer cells infected by Newcastle disease virus.

Virol J 2014 May 16;11:91. Epub 2014 May 16.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia.

Background: Newcastle disease virus (NDV), a single-stranded RNA virus of the family Paramyxoviridae, is a candidate virotherapy agent in cancer treatment. Promising responses were observed in clinical studies. Despite its high potential, the possibility of the virus to develop a persistent form of infection in cancer cells has not been investigated. Occurrence of persistent infection by NDV in cancer cells may cause the cells to be less susceptible to the virus killing. This would give rise to a population of cancer cells that remains viable and resistant to treatment.

Results: During infection experiment in a series of colorectal cancer cell lines, we adventitiously observed a development of persistent infection by NDV in SW480 cells, but not in other cell lines tested. This cell population, designated as SW480P, showed resistancy towards NDV killing in a re-infection experiment. The SW480P cells retained NDV genome and produced virus progeny with reduced plaque forming ability.

Conclusion: These observations showed that NDV could develop persistent infection in cancer cells and this factor needs to be taken into consideration when using NDV in clinical settings.
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http://dx.doi.org/10.1186/1743-422X-11-91DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4030049PMC
May 2014

Structural analysis of peptides that interact with Newcastle disease virus.

Peptides 2006 Jun 27;27(6):1217-25. Epub 2005 Dec 27.

Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Malaysia.

A peptide with the sequence CTLTTKLYC has previously been identified to inhibit the propagation of Newcastle disease virus (NDV) in embryonated chicken eggs and tissue culture. NDV has been classified into two main groups: the velogenic group, and mesogenic with lentogenic strains as the other group based on its dissociation constants. In this study the peptide, CTLTTKLYC, displayed on the pIII protein of a filamentous M13 phage was synthesized and mutated in order to identify the amino acid residues involved in the interactions with NDV. Mutations of C1 and K6 to A1 and A6 did not affect the binding significantly, but substitution of Y8 with A8 dramatically reduced the interaction. This suggests that Y8 plays an important role in the peptide-virus interaction. The three-dimensional structure of the peptide was determined using circular dichroism (CD), nuclear magnetic resonance (NMR), and molecular modeling. The peptide exhibited two possible conformers. One that consists of consecutive beta-turns around T2-L3-T4-T5 and K6-L7-Y8-C9. The other conformer exhibited a beta-hairpin bend type of structure with a bend around L3-T4-T5-K6.
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http://dx.doi.org/10.1016/j.peptides.2005.11.018DOI Listing
June 2006