全國中小學科展

醫學與健康科學

Understanding the Modern Diagnoses of Protein C Deficiency "Pcd" with Unknown Gene Plays a Critical Role in the Inherited Thrombophilia

Protein C deficiency (PCD) is found in 1 out of 200 to 500 persons in the general global population which is also one of the common conditions of Inherited thrombophilia, it’s characterized by an increased tendency of blood to clot in human blood vessels. It is caused by several factors including mutations in the genes involved in thrombin binding, protein c activation and numerous clotting factors. This includes F5 (Factor 5 Leiden) gene on chromosome 1q24.2, F7 (Prothrombin) gene on chromosome 13q34, SERPINC1 (serpin peptidase inhibitor C) on chromosome 1q25.2, SERPIND1 (serpin peptidase inhibitor D) on chromosome 22q11.21, HRG (Histidine Rich Glycoprotein) on chromosome 3q27.3, PLAT (Plasminogen Activator) on chromosome 8q11.21 and THBD (Thrombomodulin) gene on chromosome 20p11.21. In the current study, a three Saudi families with inherited thrombophilia has been recruited to identify the underlying cause of this special condition. Whole exome sequencing, targeting all coding exons of the human genome, was performed using Illumina Nextera library preparation kits followed by paired-end sequencing on Illumina NextSeq500 instrument. Reads quality control was performed and reads were aligned to the reference genome using BWA software. Variants calling and annotation was performed using GATK. All known genes involved in causing inherited thrombophilia All known genes involved in causing PCD were excluded by whole exome sequencing. The genes that were previously reported to be involved in inherited thrombophilia were checked for any causative variant. No mutation has been identified in known genes. identifying a novel gene underlying PCD. The Result of this study will hopefully pave the way to better understanding the disease pathophysiology and help in developing DNA based diagnosis, carrier screening and somatic gene therapy.

綠茶多酚EGCG對小腦萎縮抗氧化保護之探究

小腦萎縮症第三型SCA3為體染色體顯性遺傳疾病。已知為CAG三核甘酸重複序列數目過多的動態突變,造成polyQ在腦部神經細胞核內形成包含體,這種蛋白在細胞內長期堆積會導致細胞退化並死亡。此外,在SCA3熱休克蛋白的表現量較低,使蛋白不正常聚集造成細胞大量釋放氧化性刺激,促使細胞走向凋亡。根據先前研究發現低劑量綠茶多酚EGCG (epigallocatechin-3-gallate) 具有抗氧化且選擇性保護神經細胞的功能,避免氧化壓力導致細胞凋亡。此研究以SCA3患者與正常人的淋巴母細胞株來研究,給予EGCG保護來觀察EGCG在患者與正常人的細胞內對H2O2氧化壓力的耐受性差異,進一步探討EGCG對SCA3熱休克蛋白的表現量,同時觀察EGCG是否影響抗凋亡蛋白的表現。

Chitosan Defies Death

Gangrene is the death of tissue of certain parts of the body. In Indonesia, people who suffer from Diabetes will also often suffer from Gangrene, which usually affects a patient’s feet. The medication for it is not affordable for everybody. I have chosen the Horseshoe Crab, simply because it’s known widely in Indonesian and can be found easily. Also, due to the fact that, among all crustaceans, the Horseshoe Crab contains the highest levels of Chitin. By using the Chitin found in the shell of the Horseshoe Crab, I shall endeavor to heal the Gangrene of Diabetic Patients.

Antiviral Therapy for Hepatitis C Virus (HCV): Black Mustard Seeds

Hepatitis C Virus (HCV) is an RNA virus, which is considered the main cause of progressive chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC) worldwide. The number of the patients who are infected with this sleeping virus is increasing rapidly every year, as the unsuitability of the current therapy – interferon α and ribavirin – for most of the genotypes is the main cause of these high rates. Hence, the recent researches are focusing on finding out a new immunotherapy to affect this virus. In this research work, Black Mustard (Brassica nigra) has been used as powdered spice samples to prepare aqueous extracts; One of the included phytochemicals in the black mustard; glucosinolates and their hydrolysis products, was proposed to be used for the HCV patients to prevent the virus progression. Also, the Isothiocyanates are shown with chemotherapeutic and anti-tumor properties. Moreover, some of the structure-related isothiocyanates have the ability to induce the enzyme paraoxonase-1 (PON-1) that is considered hepato-protective agent against liver impairment, inflammation, fibrosis and liver disease mediated by monocyte chemoattractant protein-1 (MCP-1), and is thought to affect the entry of the virus into the hepatocytes. The effect of the black mustard and the produced myrosinase enzyme on the HCV RNA replication is still unknown. In conclusion, the black mustard is thought to affect the progression and the fluidity of the HCV envelope resulting in impairment of viral binding and fusion.

葉酸缺乏及葉酸補充調控乳癌細胞轉化成癌幹細胞並促進體外腫瘤形成

研究指出葉酸營養狀態與乳癌的風險有相互關聯且癌幹細胞是扮演癌症轉移的主要角色。葉酸缺乏和葉酸補充皆能促進癌細胞的轉移。本研究探討葉酸營養不良和葉酸補充是否會促進乳腺癌細胞轉變成癌幹細胞,將乳癌細胞株養於正常葉酸、低葉酸和高葉酸中,藉以模仿癌症病人的葉酸營養狀態。細胞在每個葉酸濃度中培養2、 4 、 8 天後再培養於腫瘤球體培養液中並測量四種幹細胞標記-mTOR,SHH,Sox2和Nanog。結果顯示:低葉酸會導致癌細胞的生長停滯,藉由標記的表達增加顯示長期低葉酸會促進細胞轉變成癌幹細胞。於腫瘤球體培養液時,低葉酸組亦較對照組於體外產生較大及較多的腫瘤球。高葉酸組會加速癌細胞的增殖和向癌幹細胞的轉變且細胞增生較快並表達較多的標記,其腫瘤球體亦是最大和豐富的。總之,低葉酸和高葉酸都增強了乳腺癌細胞的腫瘤生成和轉變成癌幹細胞。

Development of Biomimetic Skins

The objective of the project is to develop a novel biomimetic membrane and/or a scaffold for the said membrane. The approach of the project is to use animal skin from the domesticated pig or fish as a scaffold material for the adherence and growth of human skin fibroblasts to create a biomimetic membrane that can be used in medical applications as an alternative to today’s gold standards of Xenograft, Allograft and Autograft procedures. The biomimetic skin membrane can be used to treat victims of burns or scarring with a natural material that would be eliminated via natural bodily functions while eliminating the side effects and drawbacks such as scarring, secondary infections and tissue damage resulting from the current gold standard graft procedures on donor sites. Pig and fish skins were treated with ethanol and dehydrated followed by perfusion with Phosphate buffer solution and Cell culture media. Human skin fibroblasts (NF3 cells) were seeded on the animal skin scaffold. The human skin fibroblasts were then observed to determine their morphology and membrane formation properties. It was observed that the human skin fibroblasts were able to adhere to the non-human skin scaffolding and proliferate. More research is needed to determine their viability as a biomimetic membrane.

CHST11基因表現量對於肺癌細胞產生上皮間質轉化(EMT)之影響 The Expression of CHST11 Controls Epithelial-to-Mesenchymal Transition in lung cancer cells

肺癌的轉移是治療失敗的主因之一,因此了解癌細胞轉移的機制對於治療肺癌極為重要。上皮間質轉化(EMT)是癌細胞轉移的起始,且代謝體異常更是影響肺癌細胞EMT的關鍵,然而相關機制仍不明確。本研究對肺腺癌細胞EMT前後的基因體學資料(GSE49644),以及臨床上246位肺腺癌病人的EMT狀態(GSE31210),分析其關聯性以及預後指標意義。根據分析結果,並進一步查閱相關文獻後發現CHST11在癌症中角色極不明確,因此,我們針對CHST11基因進行進一步的研究,探討CHST11表現量與肺癌細胞發生EMT的關係以及其可能機制。 根據實驗結果,本研究發現:一、葡萄胺聚糖生合成路徑與非小細胞肺癌的 EMT高度相關; 二、CHST11- SNAI2路徑可調控肺癌細胞EMT過程; 三、 CHST11可做為肺癌病人的不良預後指標。這些結果或許能幫助我們更了解在肺癌細胞的代謝體異常對於肺癌細胞EMT過程中的作用。

味噌萃取物Soyasaponin I 抑制肺癌細胞轉移並且減少細胞激素分泌及抑制惡體質進展

研究指出Soyasaponin I 是味噌中的一種成分,其效果可以抗發炎,因此,本實驗想使用Soyasaponin I 探討其是否能應用於肺癌治療,及其對肺癌的轉移及癌症引起惡體質影響。 方式:使用肺癌細胞A549和H1299及正常的肺細胞HEL299進行WST-8試驗,測試Soyasaponin I 對三種細胞的存活率影響,用螢光試驗及免疫染色確認死亡方式,用Western blot及免疫螢光染色測試Soyasaponin I 對p-NF-κB入核的效果,進行boyden chamber模型測試Soyasaponin I 對於A549和H1299的侵犯速度的作用,並使用ELISA測出癌症引起惡體質的細胞分泌的IL-6細胞激素濃度。為了研究Soyasaponin I對於cachexia (惡體質)的影響,我們以人類脂肪組織利用原始培養出脂肪細胞,加入Soyasaponin I於脂肪細胞,以免疫染色研究。 成果:在細胞存活實驗發現高濃度Soyasaponin I 的濃度以細胞自噬引發癌細胞死亡,且不傷害正常肺部細胞,另外低濃度的Soyasaponin I 則使兩種肺癌細胞的突觸皆縮短及細胞變圓形;用Western blotting 證明Soyasaponin I 治療後mesenchymal的標記 (N-cadherin)明顯減少,而epithelial 的標記 (E-cadherin)明顯增加,接著在boyden chamber模型發現Soyasaponin I 會引發肺癌細胞發生間質-上皮細胞轉型,轉換成爬行較慢的上皮細胞型細胞; Soyasaponin I 減少肺癌細胞IL-6的分泌,抑制發炎。用免疫組織染色證明Soyasaponin I 治療後,原始培養脂肪細胞的惡體質標記 (UCP-1)明顯減少,減少棕色脂肪細胞形成,減少能量消耗及惡體質發生。

Novel Approach to Screening Mutations Causing Retinoblastoma, a Childhood Cancer of Retina

Retinoblastoma (RB) is a childhood retinal cancer caused by mutations in the RB1 gene. Molecular diagnosis is crucial for early detection and treatment. Current DNA diagnostic screening requires substantial amounts of tumour and blood samples. However current screening methods face the challenges of limited DNA templates from minute retinal tumours and too much blood samples drawn from young patients. In addition, the starting DNA template amount and quality are important to ensure confident detection of disease-causing mutations. As the majority of RB1 mutations are unique and distributed throughout the RB1 gene with no real hot spots, the entire gene needs to be thoroughly analysed. This investigation proposes to enrich DNA samples using a whole genome amplification (WGA) step prior to RB1 mutation screening by RB1 gene-specific PCR amplification as well as high resolution melt (HRM) analysis and sequencing. It also identifies RB1 mutations in two RB patients and explores whether WGA and saliva products can be a source of DNA templates for RB1 analysis. In addition, this study was conducted based on the hypotheses that RB1 mutations were the underlying cause of the disease in the two patients, and that the products from WGA could be used specifically for RB1 gene analysis to overcome the constraint of insufficient DNA samples. Two anonymised genomic DNA samples from two unrelated RB patients and five normal healthy DNA samples were used in this project. WGA kits were compared according to three criteria, namely amplification yield, product fragment size and whether DNA is amplifiable. Prior to and after amplification, the optical density of two normal samples was measured to determine the increase in DNA yield. The amplicons were subjected to gel electrophoresis to determine the product fragment size. Exons 6, 14 and 25 of the original and amplified samples undergone PCR, and were examined again using gel electrophoresis to ascertain that the amplicons were amplifiable. Mutation analysis using HRM was carried out with pre-existing primers for all 27 exons and the promoter of RB1. Samples from patients were analysed against 83 saliva DNAs extracted using Oragene•DNA (OG-500) Kit. REPLI-g was observed to produce higher yield and products of reliable fragment size. Single distinct bands were also seen for exons amplified using REPLI-g, indicating that REPLI-g is more accurate and suitable in the amplification of DNA. Abnormal melt profiles were obtained for exon 6 in RB477 and exon 14 in RB572 for HRM. These exons were sequenced to determine the exact mutation. Exon 6 was found to have a splice-site mutation g.607+1G>T, while a point mutation, g.1363C>T (p.Arg455X) was identified in exon 14. Both the uses of saliva as a non-invasive DNA source and the WGA approach for enriching DNA sample for application in RB1 gene analysis have never been reported for RB. Although HRM analysis has been used for other diseases, this is its first instance applied in work on RB1 gene. In short, this report offers novel and promising approaches which would contribute significantly to the molecular analysis of mutations in RB.

An investigation of the inhibitory potential of Dronedarone on CYP2J2 mediated astemizole metabolism

Dronedarone is an anti-arrhythmic drug approved in 2009 for paroxysmal and persistent atrial fibrillation. It is less toxic than its predecessor Amiodarone as it does not cause systemic toxicity but has the same pharmacological activity. However the administration of dronedarone to permanent AF and heart failure patients leads to increased risk of stroke and cardiac death. The exact mechanism of the toxicity is currently unknown. Extrahepatic Cytochrome P450 enzymes play a dominant role in organ-specific drug metabolism and toxicity. Cytochrome P450 2J2 (CYP2J2) enzyme, a predominant enzyme found in human cardiac myocytes, metabolizes endogenous arachidonic acid (AA) into epoxyeicosatrienoic acids (EETs) which play an important role in maintaining normal cardiac physiology. Inhibition of CYP2J2 and perturbation of AA metabolic pathway could result in exacerbation of cardiac failure. This research aims to find out whether dronedarone inhibits CYP2J2 in a suitable cell model (H9C2) using astemizole as a probe substrate. Our in-house studies using recombinant CYP2J2 enzyme have shown that dronedarone potently inhibits CYP2J2. Rat myoblast cells (H9C2) will be seeded in 12-well plate and differentiated for 4 days. The cells will be then treated with different concentrations of astemizole and incubated for 24 h. The cells will then be harvested, lysed, and the cell lysate will be analyzed using liquid chromatography-mass spectrometry (LCMS). Using multi-reaction monitoring (MRM) on the LCMS, astemizole concentration as well as its CYP2J2-specific metabolite O-desmethylastemizole concentrations will be measured. The presence of O-desmethylastemizole confirms the metabolism of astemizole by CYP2J2 in H9C2 cells. By plotting a Michaelis-Menten kinetics curve, we will be able to determine the Michaelis constant (KM) and maximum rate of reaction (Vmax). H9C2 cells will be then treated with fixed concentration of astemizole while varying the dronedarone concentration. A decrease in metabolite O-desmethylastemizole conce ntration, indicates inhibition of CYP2J2 metabolism by dronedarone. Using this data, Lineweaver-Burke graph will be plotted, to determine the mode and potency of the inhibition. Our preliminary studies showed that the KM value was 2.7μM. This study will be useful in understanding if dronedarone inhibits CYP2J2 which may lead to clinically significant drug-drug interactions, one of the dangers of polypharmacy. Finally this study will shed a new light on the mechanisms for dronedarone mediated cardiac failure exacerbation.