Coronary Artery Disease: Association Study of 5 Loci with Angiographic Indices of Disease Severity

Background. Different common gene variants were related to coronary artery disease (CAD) in many studies. Yet, the relation of these loci to the severity of CAD is not completely elucidated. Methods. We enrolled 520 subjects (315 CAD cases and 205 controls). CAD presence and extension were assessed by coronary angiography (CAG). Genotyping of five SNPs (namely, rs2230806 (1051G > A) in ABCA1 on chromosome 9, rs2075291 (553G > T) in ApoA5 on chromosome 11, rs320 in LPL on chromosome 8 intron (T → G at position 481), rs10757278 (c.22114477A > G), and rs2383206 (c.22115026 A > G) on chromosome 9p21 locus) was performed by allele-specific PCR. The degree and site of arterial lesions were used to classify patients, tested for association with CAD severity, and related to allele dosage. Results. The polymorphisms rs2383206 and rs10757278 showed significant associations with 2- and 3-vessel coronary disease (p =0.003 and 0.006, respectively). The homozygous GG genotypes of rs10757278 was associated with higher frequency of left anterior descending (LAD), right coronary artery (RCA) and left circumflex (LCX) diseases (p =0.002, 0.016 and 0.002, respectively). The GG genotypes of rs2383206 were found in higher percentage in patients with left main (LM) trunk and left circumflex (LCX) diseases ( p = 0.013 and 0.002, respectively). Conclusion. SNPs rs10757278 and rs2383206 allele dosage could predict CAD severity in the Saudi Arab population.

The CAD risk locus 9p21 increases the risk of vascular calcification in an iPSC-derived VSMC model

Background Coronary artery disease (CAD) is the leading cause of death worldwide. Chromosome locus 9p21 was the first to be associated with increased risk of CAD and coronary artery calcification (CAC). Vascular calcification increases the risk for CAD. Vascular smooth muscle cells (VSMCs) are one of the major cell types involved in the development of vascular calcification. Methods So far, mainly animal models or primary SMCs have been used to model human vascular calcification. In this study, a human in vitro assay using iPSC-derived VSMCs was developed to examine vascular calcification. Human iPSCs were derived from a healthy non-risk (NR) and risk (R) donor carrying SNPs in the 9p21 locus. Additionally, 9p21 locus knockouts of each donor iPSC line (NR and R) were used. Following differentiation, the iPSC-derived VSMCs were characterized based on cell type, proliferation, and migration rate, along with calcium phosphate (CaP) deposits. CaP deposits were confirmed using Calcein and Alizarin Red S staining and then quantified. Results The data demonstrated significantly more proliferation, migration, and CaP deposition in VSMCs derived from the R and both KO iPSC lines than in those derived from the NR line. Molecular analyses confirmed upregulation of calcification markers. These results are consistent with recent data demonstrating increased calcification when the 9p21 murine ortholog is knocked-out. Conclusion Therefore, in conclusion, genetic variation or deletion of the CAD risk locus leads to an increased risk of vascular calcification. This in vitro human iPSC model of calcification could be used to develop new drug screening strategies to combat CAC.

Novel synthetic lethality (SL) anti-cancer drug target in urothelial bladder cancer (UCB) based on MTAP genomic loss: Incidence and correlations in standard of care (SOC).

485 Background: When UCB presents or progresses to chemorefractory metastatic disease, the search for new therapy targets is paramount. Targeting PRMT5 arginine methyltransferase accumulation in tumors with MTAP (methylthioadenosine Phosphorylase) genomic loss has been proposed as a new SL based anti-tumor strategy and under consideration for development for UCB. We sought to evaluate the incidence of patients with candidate SL and correlate to treatment-guiding biomarkers currently evaluated in SOC. Methods: 2,683 cases of clinically advanced UCB underwent hybrid-capture based comprehensive genomic profiling in a standard of care setting using the F1CDx FDA-approved assay to evaluate all classes of genomic alterations (GA) among 324 genes. Tumor mutational burden (TMB) was determined on 0.8 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 95 loci. PD-L1 expression was determined by IHC (Dako 22C3). Results: 650 (24%) of UCB feature MTAP loss (MTAP-) (Table). The gene and age distributions were similar MTAP intact (MTAP+) and MTAP- UCB. The GA/tumor was higher in MTAP- UCB likely reflecting the significant GA co-deletions of CDKN2A/ B at the 9p21 locus. Of potential therapeutic targets, FGFR3 and PTEN GA were more frequent in the MTAP- UCB. In contrast, biomarkers of immunotherapy (IO) response included higher frequencies of high TMB and high PD-L1 IHC staining in the MTAP+ UCB. Conclusions: When compared with MATP+ UCB, MTAP- UCB differs in genomic signatures including an increase in potential for targeted therapies but a lower potential for IO drug benefit. Thus, the genomic landscape in MTAP- UCB may play a significant role in the design of clinical trials incorporating SL strategies when targeting PRMT5 in MTAP deficient tumors. [Table: see text]

The CAD risk locus 9p21 increases the risk of vascular calcification in an iPSC-derived VSMC model

Background: Coronary artery disease (CAD) is the leading cause of death worldwide. Chromosome locus 9p21 was the first to be associated with increased risk of CAD and coronary artery calcification (CAC). Vascular calcification increases the risk for CAD. Vascular smooth muscle cells (VSMCs) are one of the major cell types involved in the development of vascular calcification. Methods: So far, mainly animal models or primary SMCs have been used to model human vascular calcification. In this study, a human in vitro assay using iPSC-derived VSMCs was developed to examine vascular calcification. Human iPSCs were derived from a healthy non-risk (NR) and risk (R) donor carrying SNPs in the 9p21 locus. Additionally, 9p21 locus knockouts of each donor iPSC line (NR and R) were used. Following differentiation, the iPSC-derived VSMCs were characterized based on cell type, proliferation and migration rate, along with calcium phosphate (CaP) deposits. CaP deposits were confirmed using Calcein and Alizarin Red S staining and then quantified. Results: The data demonstrated significantly more proliferation, migration, and CaP deposition in VSMCs derived from the R and both KO iPSC lines than in those derived from the NR line. Molecular analyses confirmed upregulation of calcification markers. These results are consistent with recent data demonstrating increased calcification when the 9p21 murine ortholog is knocked-out. Conclusion: Therefore, in conclusion, genetic variation or deletion of the CAD risk locus leads to an increased risk of vascular calcification. This in vitro human iPSC model of calcification could be used to develop new drug screening strategies to combat CAC.

Genetics of Adult Onset Stroke Subtypes: A Review of Current Knowldege and Future Prospects

The genetic contribution in stroke onset depends on the stroke subtypes. Understanding the genetic mechanism may influence the future direction in stroke management. There is complex interplay of genetic and environmental factors for any stroke event. Very small proportion of stroke is attributable to mendelian disorders. Stroke may also manifest as part of a syndromic disease in the form of single gene multisystem disorder. But there is no direct contribution of genetic polymorphism in conventional stroke subtypes. Specific genetic loci increase the suspectibility to development of hypertension, diabetes, dyslipideamia or influence the coagulation pathway or chance of atheroma formation and embolism. While chr9p21 locus or PITX2 and ZFHX3 are related to cardioemetabolic, HDAC9, TSPAN2 and 9p21 locus are responsible for the large vessel occlusion. On the otherhand, genome-wide significant locus on chromosome 1q22 the APOE locus are found to have significant association with intracerebral hemorrhage. But the direct pathophysiologic relationship of genetic plymorphirsm may be linked to onset of sub arachnoid hemorrhage. MMP-3, endothelial nitric oxide synthase (eNOS), tumor necrosis factor (TNF)-α, VCAM-1 etc have been found to be responsible for intracranial aneurysm formation, growth and risk of rupture. Journal of National Institute of Neurosciences Bangladesh, January 2021, Vol. 7, No. 1, pp. 75-86

An assessment of chromosomal alterations detected by fluorescence in situ hybridisation in pancreatobiliary tract malignancy

Background Using fluorescence in situ hybridisation (FISH) to detect any gain of chromosomes 3, 7, or 17 and loss of the 9p21 locus has been proven to be sensitive in the diagnosis of pancreatobiliary tumors. However, both genetic and environmental factors contribute to the pathogenesis of pancreatobiliary tumors. Therefore, it is unknown whether this method is suitable for Chinese patients with pancreatobiliary tumors. This study aims to compare the sensitivity, specificity, predictive values and accuracy of cytology, ERCP/MRCP and FISH based on Chinese patients with pancreatobiliary tumors,and to analyze differences between brushing-based and formalin-fixed paraffin-embedded (FFPE)-based FISH. Methods A total of 66 brush cytology specimens obtained during ERCP were detected by FISH and cytology test respectively to compare the sensitivity, specificity, predictive values and accuracy. Besides, FFPE-based FISH was performed on 46 corresponding paraffin sections of pancreatobiliary tumors obtained by surgical resection. Results Our findings demonstrate that FISH greatly improves diagnostic sensitivity and negative predictive value compared to ERCP/MRCP and cytology without much reduction in specificity and positive predictive value. However, our results also indicate that FFPE-based FISH could not effectively identify the false-negative of brushing-based FISH. Conclusions We believe that FISH can effectively distinguish true positive and false positive results of cytological or radiological suspicions of malignancy. However, FFPE-based FISH still does not precisely recognize the false-negative of brushing-based FISH. Both cytology-based and PPFE-based FISH had limitation in some specimens.