FORWARD AND UNBIASED RNA-INTERFERENCE SCREEN

RNA-interference (Fire et al. 1998) is a popular ‘reverse-genetics’ screening strategy applied in Caenorhabditis elegans. Genome-wide RNAi screens are presently carried using RNAi feeding libraries. Here, we report on a complementary resource facilitating an approach to RNAi screen relying on an unbiased ‘forward-genetics’ strategy. We conclude the forward RNA interference screening is useful and feasible, with the strong expectation the presented screening mode will complement and extend on the existing, currently available, genome-wide RNAi resources.

Topologically Associating Domain Boundaries are Commonly Required for Normal Genome Function

Topologically associating domain (TAD) boundaries are thought to partition the genome into distinct regulatory territories. Anecdotal evidence suggests that their disruption may interfere with normal gene expression and cause disease phenotype, but the overall extent to which this occurs remains unknown. Here we show that TAD boundary deletions commonly disrupt normal genome function in vivo. We used CRISPR genome editing in mice to individually delete eight TAD boundaries (11-80kb in size) from the genome in mice. All deletions examined resulted in at least one detectable molecular or organismal phenotype, which included altered chromatin interactions or gene expression, reduced viability, and anatomical phenotypes. For 5 of 8 (62%) loci examined, boundary deletions were associated with increased embryonic lethality or other developmental phenotypes. For example, a TAD boundary deletion near Smad3/Smad6 caused complete embryonic lethality, while a deletion near Tbx5/Lhx5 resulted in a severe lung malformation. Our findings demonstrate the importance of TAD boundary sequences for in vivo genome function and suggest that noncoding deletions affecting TAD boundaries should be carefully considered for potential pathogenicity in clinical genetics screening.

A novel gene-diet interaction promotes organismal lifespan and host protection during infection via the mitochondrial UPR

Cells use a variety of mechanisms to maintain optimal mitochondrial function including the mitochondrial unfolded protein response (UPRmt). The UPRmt mitigates mitochondrial dysfunction by differentially regulating mitoprotective gene expression through the transcription factor ATFS-1. Since UPRmt activation is commensurate with organismal benefits such as extended lifespan and host protection during infection, we sought to identify pathways that promote its stimulation. Using unbiased forward genetics screening, we isolated novel mutant alleles that could activate the UPRmt. Interestingly, we identified one reduction of function mutant allele (osa3) in the mitochondrial ribosomal gene mrpl-2 that activated the UPRmt in a diet-dependent manner. We find that mrpl-2(osa3) mutants lived longer and survived better during pathogen infection depending on the diet they were fed. A diet containing low levels of vitamin B12 could activate the UPRmt in mrpl-2(osa3) animals. Also, we find that the vitamin B12-dependent enzyme methionine synthase intersects with mrpl-2(osa3) to activate the UPRmt and confer animal lifespan extension at the level of ATFS-1. Thus, we present a novel gene-diet pairing that promotes animal longevity that is mediated by the UPRmt.

First year outcomes of an initiative to increase BRCA testing among NCCN guideline-eligible breast cancer patients within a large community OCM practice.

1540 Background: Pathogenic variants in BRCA1/BRCA2 can affect a breast CA pts care: preventative interventions, surgical decisions, medical treatments, screening, and family counseling. National data suggests significant non-adherence to NCCN testing guidelines, with only 1/3 of eligible pts referred for genetic services. In 2018, OHC (Cincinnati) launched an APP-centric genetics program. Specially trained APPs carry out genetic counseling and order NCCN-compliant testing. Early data suggested a significant deficit in physician-driven referrals. From 1/01/18 - 07/31/18, 138 new breast pts were estimated to be NCCN guideline-eligible. Only 28 (20%) pts received genetic services. Methods: In 2019, the OHC genetics team implemented a standardized screening process for every new breast CA pt. An EMR template (iKnowMed G2) that included NCCN guidelines was created for initial breast CA consultation and Oncology Care Model (OCM) treatment planning. All pts, not just OCM pts, are subject to OCM treatment planning. This automated screening method ensured all breast CA pts were screened, drastically increasing compliance. Through integration of genetics screening into the templates, pts meeting NCCN criteria for testing are reflexively referred for genetic counseling. With USON/McKesson, integrated data fields were developed in the EMR to automate data collection. Results: From 01/01/19 – 12/31/19, 717 new breast CA pts were seen at OHC. 676/717 (94%) were screened. Of those screened, 279 new breast CA pts met NCCN criteria for BRCA testing. 140 (50%) eligible new pts had appts with the genetics team. Another 50 (18%) had confirmed testing outside of OHC. 57 (20%) refused appts and/or testing. 32 (11%) did not have appts, representing screen fails. Referrals in non-breast CA pts also increased by 127%; 604 (2019) vs 264 (2018) suggesting a halo effect. Analyses suggest the program to be economically viable, with a financial growth rate of 127%. Conclusions: EMR templates embedded with the NCCN guidelines for reflex genetics referral can appropriately increase the utilization of genetic services. Breast genetics screening and resultant appt/testing rates increased significantly 2019 vs 2018. Success in BRCA testing in breast CA will lead to expansion to other cancers and genes. Implementation of structured EMR genetics data fields can automate data collection and measure compliance. Integration of genetics screening into universal OCM treatment planning is feasible, economically viable and scalable.

A Review of Pancreatic Cancer: Epidemiology, Genetics, Screening, and Management

Pancreatic cancer ranks among the causes of cancer-related deaths. The average size of pancreatic cancer during diagnosis is about 31 mm and has not changed significantly over the past 30 years. Poor early diagnosis of a tumour has been attributed to the late-presenting symptoms. Over the years, improvement in the diagnosis of pancreatic cancer has been observed, and this can be linked to advancement in imaging techniques as well as the increasing knowledge of cancer history and genetics. Magnetic Resonance Imaging, Endoscopic Ultrasound, and Computer Topography are the approved imaging modalities utilised in the diagnosing of pancreatic cancer. Over the years, the management of patients with pancreatic cancer has seen remarkable improvement as reliable techniques can now be harnessed and implemented in determining the resectability of cancer. However, only about 10% of pancreatic adenocarcinomas are resectable at the time of diagnosis and will highly benefit from a microscopic margin-negative surgical resection. Overall, the failure of early tumour identification will result in considerable morbidity and mortality.

Một số đặc điểm rối loạn nhiễm sắc thể ở phôi ngày năm thụ tinh trong ống nghiệm

Sàng lọc di truyền trước chuyển phôi (Preimplantation Genetics Screening – PGS) là phương pháp sử dụng các kỹ thuật sàng lọc phân tích bản chất di truyền bên trong của phôi để chọn được những phôi bình thường về di truyền giúp tăng tỉ lệ chuyển phôi thành công trong thụ tinh trong ống nghiệm (In Vitro Fertilization - IVF). Mục tiêu: Đánh giá tình trạng bất thường NST của phôi ngày năm bằng kỹ thuật giải trình tự thế hệ mới (NGS). Phương pháp: Phân tích bộ NST của 50 mẫu tế bào được sinh thiết từ các phôi hiến tặng ngày 5 bằng bộ Veriseq (Illumina) trên hệ thống giải trình tự Miseq và phần mềm Multi Bluefuse 4.4. Kết quả: Kết quả phân tích cho thấy tỷ lệ phôi có bộ NST bình thường là 24%, tỷ lệ phôi có bộ NST bất thường là 76% trong đó 30% bất thường số lượng NST và 24% số phôi có bất thường về cấu trúc, 22% số phôi có cả 2 loại rối loạn cấu trúc và sô lượng NST. Kết luận: Bất thường NST chiếm tỷ lệ cao ở phôi ngày 5. Vì vậy, sàng lọc di truyền trước chuyển phôi nhằm tăng tỷ lệ thành công của thụ tinh trong ống nghiệm là rất cần thiết.