Group Members

The project is designed to find genetic and environmental factors that increase susceptibility to drug use disorder as well as to develop a pharmacogenetic database for the application of personalised medicine. The information can later be applied to identify individuals most likely to develop drug use disorder towards which preventive efforts can be focussed. Ethnic and geographical differences in pharmacogenetics are well known. Many pharmacogenetic-based normograms have been derived using selected and limited populations and are not generalizable. Specifically data from this region is lacking. This project aims to fill the gaps by investigating the types and frequencies of relevant genetic polymorphism in several important sub-population of South East Asia. The data thus generated will be used to investigate the genetic relatedness of the study populations. Association with drug use disorder will also be investigated using suitable bioinformatic tools. The genes to be investigated include OPRD1, OPRK1, OPRM1, HLA-B and 5HT. The populations to be studied include Orang Asli (Mah Meri tribe), Malay, Chinese and Indian in Malaysia and Javanese in Indonesia. Apart from the usual outputs of new knowledge generated, research publications, human resource training, this project will generate a pharmacogenetic resource database for use by other researchers and drug manufacturers.

Lung diseases remains the commonest cause of death worldwide, thus finding alternative approaches for a better treatment needs to be done. Aerosolization technique is carried out in this study to deliver akin-derived fibroblast cells and airway epithelial cells to repair the damaged trachea. A lot of studies had reported a problem of donor-derived cells engraftment, which mentioned low retention and engraftment of delivered cells are persistent obstacles in cells transplantation applications. Thus, using aerosolization technique, cells will be easily delivered into the surface of the trachea and lungs, then integrated and replaced the damaged tissue. Direct application of the cells into the lung makes this technique a more reliable and efficient means of delivering cells. The injury caused by a tracheal brushing technique that has been established in our group, induces perturbation on the rabbit tracheal epithelium structure. The fibroblast cells derived from rabbit skin and epithelium cells from a dissociated rabbit trachea will be propagated until a few passages. Both cells will be labelled with Bromo-deoxyuridine (BrdU) then administered into an injured rabbits using MicroSprayer® Aerosolizer. Immuno-staining using anti-BrdU specific antibody permits BrdU to be detected in cell nucleus. Following aerosolization, survival, engraftment, and localization of delivered cells will be observed and we hypothesise the administered cells will participate in dedifferentiation, migration, proliferation, and redifferentiation to form a new layer of epithelial cells. Therefore, the application of this method is believed to create a promising technique of cell-based delivery for future therapy in lung related diseases.

A research study of cancer continually surprises people with new findings and treatment. Until these days, there is still no solid cure for cancer disease. As been discussing above, cancer can spread from one vital organ to another organ or known to be metastasis. This metastasis happen due to cell-cell communication and notch signalling is known to be one of the crucial pathways involve in metastasis activity. The understanding of the notch signalling pathway in controlling metastasis of lung cancer stem cell will be beneficial in cancer therapy and drug development that can target on specific molecule or stages in the lung cancer development. Curcumin, a naturally occurring polyphenol extracted from the rhizome Curcuma longa has a long history of use as an Asian spice as well as in traditional therapies. Apart from that, curcumin also possess high antimetastatic effect. It enhances the expression of antimetastatic proteins TIMP-2, Nm23, and E-cadherin, which reduce the metastatic tendency of melanoma cells. Curcumin inhibited the expression of COX-2 and MMP-9, which in turn altered the invasive and metastatic properties of the cells. This study is design to investigate the small population of CSCs that reside in lung cancer cells that possess the characteristic of resistance toward conventional chemotherapy drugs and the ability of these stem cells to develop lung cancer in vitro as well as to study the potential of Curcumin as drug sensitizer and metastasis inhibitor on isolated cancer stem. Basically, methods used involve culturing, propagation and maintenance the cancer cell. Following this is flow cytometry and Semi-Quantitative PCR which is used to observe the expression level of cancer and cancer stem cell after treatment with curcumin. The importance of this study is to investigate the role of curcumin as a sensitizer which help in killing the cancer stem cells.

Most cancers comprise a heterogenous population of cells with marked differences in their potential to proliferate as well as the ability to reconstitute the tumor upon transplantation. Upon cancer treatments, these small populations of cancer cells show resistance to therapies, therefore can grow and repopulate the cancer cell population thus spread the cancer cells to various organs. These chemo-resistant and ‘cancer-initiating cells’ is called cancer stem cells (CSCs). CSCs have similarity with normal stem cell features and we postulate that normal stem cell and CSCs possess similar self-renewal mechanism and differentiation. This study was designed to identify and isolate isolate putative CSCs from NSCLC type of lung cancer and to test their capability to develop lung cancer in vitro and in vivo. Using in vitro model system, we want to study on the basic mechanism of CSCs initiating cancer cell population either through fusion with normal airway epithelial cells and/or CSCs stands as its own entity by accelerating its growth in cell culture condition using co-culture technique of air-liquid interface (ALI) culture. The isolated cancer and normal stem cells will also be analyzed using whole genome expression study using microarray as to further understand the molecular signatures of lung CSCs by investigating the transcriptomic and signaling cascades that composes and maintains the CSC properties that unique in cancer versus normal stem cells. For in vivo study, we aim to understand the ability of isolated putative lung CSCs to develop lung cancer in NOD/SCID mice model and whether or not the injected CSCs have the ability to metastasize. Understanding the biology of lung CSCs and whether these lung CSCs initiate lung cancer development may open up a new approach in lung cancer treatment that specifically target these cancer initiating cells.

Asthma is one of the chronic lung diseases that have become pandemic around the world. Drug-based therapy has become the common treatment in alleviating asthmatic attacks. However, prolong usage of drug may lead to several side effects such as oropharyngeal candidiasis, dysphonia, headache, growth retardation and others. Thus, it is crucial to find alternative treatment to replace corticosteroid. Honey has been proved having many biological properties that can be used in treating other illness including cough and fever. In fact, previous finding also suggest the effectiveness of honey nebulisation in alleviating acute asthma in paediatric patients. However, the effect of honey in reducing asthma at both cellular and molecular level has never been investigated. Thus, this study aims to assess the effect of aerosolised-honey on histopathological changes of airway in animal models of asthma and genes that involved in the occurrence of asthma. To achieve this, two models has been developed to determine whether honey can act as preventive agent by preventing the occurrence of asthma or to act as rescue by reducing asthma related symptoms. Rabbits are used as model for asthma induced by ovalbumin given via intra-peritoneal injection and inhalation. Once injury has been developed, animals then are treated with aerosolized honey by using nebulizer. The effects of honey treatments towards reducing asthma-related symptoms like goblet cell hyperplasia, mucus overproduction, and inflammatory cells infiltration will be assessed and compared with salbutamol-treated rabbits.It is hope that therapeutic properties contained in honey will be able to reduce the airway inflammation and thus replacing the usage of drug therapy in treating asthma. 

Asthma is one of the chronic lung diseases which mostly attack on children and elder. The treatment available in reducing asthma is drug based and long exposure to the drug is believed can give side effect to the patients. The main objectives of this study is to observe the effects of aerosolized VCO in reducing the asthma symptoms such as goblet cell hyperplasia and inflammatory responses as well as to find an alternative treatment for asthmatic patients by using natural products, which is and VCO. VCO has been used widely in traditional treatment even in ancient time. In order to mimic the asthma attack in human, normal New Zealand White rabbits will be sensitized with ovalbumin together with aluminium hydroxide, one of the allergen that can trigger the onset of the asthma. The sensitized rabbit then will be exposed to aerosolized VCO within a certain time point. This allows the cells to react with the bioactive and polyphenols in the VCO that later can reduce the inflammation of the cells. In determining the effect of aerosolized VCO on sensitized rabbits, several methods assessing the histological changes, protein production and genes involved during onset of the inflammation will be used. This includes H&E, AB-PAS and IHC staining, ELISA, western blot and also qPCR.

Mesenchymal stem cells (MSCs) hold a tremendous potential for therapeutic use in stem cell-based gene therapy. Given the plasticity of these stem cells, it is not surprising that they engraft as different cell types in response to different types and degree of injury. These suggest that if these stem cells can be stably transduced and maintained their plasticity, they could be an ideal population for the delivery of therapeutic genes to non haematopietic tissues. The route of stem cell delivery to the target organ i.e the lung must be very effective in the sense that the technique should be very specific and direct to the target region of the lung. For this purpose, this study will apply the intratracheal administration of adipose derived-MSCs using microsprayer in which the stem cells is transformed in an aerosol form direct to the lung thus could enhance the stem cell delivery and engraftment. ANGP1 is a gene encoded for human angiopoeitin protein 1 (Ang1). Studies have shown that the expression of Ang 1 reduces the permeability of endothelial cells and inflammation in acute lung diseases as well as in asthma. Given its anti-inflammatory, anti-permeability and endothelial-protective characteristics, we hypothesize that ANGP1 gene transfer may be beneficial in the treatment of chronic lung disease. Combining this huge potential of MSCs for stem cell therapy with ANGP1 of gene therapy might provide large benefits as to reduce the inflammatory response of the lung following repeated exposure to ovalbumin which leads to increase homing capabilities of MSCs in regeneration and repair of damaged airway epithelium. Therefore, the aim of this study is to evaluate the effect of MSCs with and without a combination with the ANGP1 on lung inflammation and injury induced by repeated exposure to ovalbumin in rabbit model of chronic lung disease.

Lung cancer is the most common cause of cancer-related mortality worldwide with 1.37 million deaths. Despite advances in therapies, lung cancer is remained as the third highest percentage of cancer in Malaysia with the non-small cell lung cancer (NSCLC) type comprises approximately 80% out of total lung cancer incidence. This indicates the existence of a small cell population that are resistant towards current therapies. These chemo-resistant cells are called cancer stem cells. Cancer stem cell is believed to have similar capacity as normal stem cell in term of self-renewal and initiating a tumour. Opposite to cancer stem cells that have capacity to initiate the tumour, retinoids is believed to have tumour suppressor activity that function to suppress tumorigenicity. In order to play its function in regulating cell growth and cell apoptosis, retinoids require its nuclear retinoids. Loss of expression of Retinoid acid beta (RARB), which is one of the nuclear retinoids, in a NSCLC is a prognostic factor of a poor clinical outcome. Therefore, this study was designed to identify and characterize the putative cancer stem cells with the recognized cell markers; CD166, CD44 and EpCAM in NSCLC cell line; A549 and H2170 and to investigate the effect of RARβ that is believed to have tumour suppressor capacity on the stemness of isolated cancer stem cells in vitro and in vivo. Understanding the contribution and function of RARβ gene in cancer stem cell maintenance and function may lead us to improved diagnosis and treatment of NSCLC.

Airway respiratory system has been constantly challenged and exposes to various irritant. This condition leads to impairment of respiratory function. In order to withstand from harsh environment, the system well-equip with epithelial layer which primarily act as a biological barrier. Disruption on epithelial layer proved to be the factor that leads to pathological condition. In the normal state, airway epithelial cell has lower turnover calculated only 1%. Given this condition, it is crucial to induce an injury to encourage cell participate in the repairing process. Upon an injury, repairing process begins with cellular dedifferentiation, follow by migration and finally, redifferentiation that form back normal epithelial layer. Apart from that, molecular aspect may play important role in each of that process. Some of the gene highy expressed in the beginning while decrease on the later stage and vice versa. Understanding the process will give a better knowledge on how the cell works in such situation. Thus, in this study we will investigate a cellular and molecular mechanism involvement in the repair and regeneration process.  Tracheal brushing technique was used to inflict injury on rabbit trachea. Following injury, rabbit will be euthanized when reach on certain time point. There are six groups of rabbit, one is non-injured group and the rest are injured group which divided into five groups based on time point. Analysis was done using histological and molecular technique.  An understanding the cellular behave and molecular work will help in finding a better solution that can enhance the repair process.