Delineating the Mechanism of Fragility at BCL6 Breakpoint Region Associated With Translocations in Diffuse Large B Cell Lymphoma

BCL6 translocation is one of the most common chromosomal translocations in cancer and results in its enhanced expression in germinal center B cells. It involves the fusion of BCL6 with any of its twenty-six Ig and non-Ig translocation partners associated with diffuse large B cell lymphoma (DLBCL). Despite being discovered long back, the mechanism of BCL6 fragility is largely unknown. Analysis of the translocation breakpoints in 5\u27 UTR of BCL6 reveals the clustering of most of the breakpoints around a region termed Cluster II. In silico analysis of the breakpoint cluster sequence identified sequence motifs that could potentially fold into non-B DNA. Results revealed that the Cluster II sequence folded into overlapping hairpin structures and identified sequences that undergo base pairing at the stem region. Further, the formation of cruciform DNA blocked DNA replication. The sodium bisulfite modification assay revealed the single-strandedness of the region corresponding to hairpin DNA in both strands of the genome. Further, we report the formation of intramolecular parallel G4 and triplex DNA, at Cluster II. Taken together, our studies reveal that multiple non-canonical DNA structures exist at the BCL6 cluster II breakpoint region and contribute to the fragility leading to BCL6 translocation in DLBCL patients

Evaluation of potential role of R-loop and G-quadruplex DNA in the fragility of c-MYC during chromosomal translocation associated with Burkitt\u27s lymphoma

t(8;14) translocation is the hallmark of Burkitt\u27s lymphoma and results in c-MYC deregulation. During the translocation, c-MYC gene on chromosome 8 gets juxtaposed to the Ig switch regions on chromosome 14. Although the promoter of c-MYC has been investigated for its mechanism of fragility, little is known about other c-MYC breakpoint regions. We have analyzed the translocation break points at the exon 1/intron 1 of c-MYC locus from patients with Burkitt\u27s lymphoma. Results showed that the breakpoint region, when present on a plasmid, could fold into an R-loop confirmation in a transcription-dependent manner. Sodium bisulfite modification assay revealed significant single-strandedness on chromosomal DNA of Burkitt\u27s lymphoma cell line, Raji, and normal lymphocytes, revealing distinct R-loops covering up to 100 bp region. Besides, ChIP-DRIP analysis reveals that the R-loop antibody can bind to the breakpoint region. Further, we show the formation of stable parallel intramolecular G-quadruplex on non-template strand of the genome. Finally, incubation of purified AID in vitro or overexpression of AID within the cells led to enhanced mutation frequency at the c-MYC breakpoint region. Interestingly, anti-γH2AX can bind to DSBs generated at the c-MYC breakpoint region within the cells. The formation of R-loop and G-quadruplex was found to be mutually exclusive. Therefore, our results suggest that AID can bind to the single-stranded region of the R-loop and G4 DNA, leading to the deamination of cytosines to uracil and induction of DNA breaks in one of the DNA strands, leading to double-strand break, which could culminate in t(8;14) chromosomal translocation

Kawasaki disease and the environment: an enigmatic interplay

Kawasaki disease (KD) is a common systemic vasculitis of childhood. Although it has been almost 6 decades since Dr. Tomisaku Kawasaki reported the first case series of KD, the underlying cause remains a mystery. KD is a self-limiting disease. However, a dreaded complication is development of coronary artery abnormalities (CAAs). KD is the most common cause of acquired heart disease in children in the developed world and is being increasingly reported from developing countries too. Over the years, significant observations have been made about epidemiology of KD. It usually affects children below 5, has male preponderance and has significantly higher incidence in North East Asian countries. While several hypotheses have been proffered for etiology of KD, none have been conclusive. These include associations of KD epidemics in Japan and the United Stated with changes in tropospheric wind patterns suggesting wind-borne agents, global studies showing peaks of incidence related to season, and increased rates in populations with a higher socioeconomic profile related to hygiene hypothesis and vaccination. Furthermore, the self-limiting, febrile nature of KD suggests an infectious etiology, more so with sudden decline noted in cases in Japan with onset of COVID-19 mitigation measures. Finally, single nucleotide polymorphisms have been identified as possible risk alleles in patients with KD and their significance in the pathogenesis of this disease are also being defined. The purpose of this review is to elucidate the puzzling associations of KD with different environmental factors. Looking at patterns associated with KD may help us better predict and understand this disease

Exploring state-of-the-art advances in targeted nanomedicines for managing acute and chronic inflammatory lung diseases

Diagnosis and treatment of lung diseases pose serious challenges. Currently, diagnostic as well as therapeutic methods show poor efficacy toward drug-resistant bacterial infections, while chemotherapy causes toxicity and nonspecific delivery of drugs. Advanced treatment methods that cure lung-related diseases, by enabling drug bioavailability via nasal passages during mucosal formation, which interferes with drug penetration to targeted sites, are in demand. Nanotechnology confers several advantages. Currently, different nanoparticles, or their combinations, are being used to enhance targeted drug delivery. Nanomedicine, a combination of nanoparticles and therapeutic agents, that delivers drugs to targeted sites increases the bioavailability of drugs at these sites. Thus, nanotechnology is superior to conventional chemotherapeutic strategies. Here, the authors review the latest advancements in nanomedicine-based drug-delivery methods for managing acute and chronic inflammatory lung diseases

Development of a blended wing configuration MAV

Micro Air vehicles "MAV" belong to a class of aircraft currently designated with a maximum size of 300mm and are capable of operating at speeds of not less than 12 m/s. MAVs are expected to find applications in battlefield reconnaissance, visual surveillance, border patrol, etc. MAVs are typically characterized by a low aspect ratio wing operating at low Reynolds numbers (104~105). A camber plate MAV of 300mm wing span generates Cl of 0.7-0.8, comparatively Blended Wing MAV generates Cl of 1-1.3 this motivates the work to be carried out. This work contains the aerodynamic design, planform optimization, airframe modeling, production and development of a BLENDED WING MAV. Numbers of airfoils are analyzed using XFLR5 code and Martin Heppler-45 (MH-45) airfoil is selected due to its reflex at the trailing edge, very less camber of 1.17%, hence greater stability and also matches the requirements of the MAV. 2D CFD analysis is done using NAL RANS 3D code to validate the XFLR5 results of MH 45. Winglets were designed empirically using vertical tail volume coefficient (CVT). Polymer and Composite materials like- Acrylonitrile Butadiene Styrene (ABS), Kevlar & Rohacell, are used for fabrication of airframe and skin structure. An advanced technique like Rapid prototyping is used to produce the airframe and composite sandwich method is used for the skin material. Flight tests have been carried successfully and results are also discussed in this paper

Microbiome and Its Dysbiosis in Inborn Errors of Immunity

Inborn errors of immunity (IEI) can present with infections, autoimmunity, lymphoproliferation, granulomas, and malignancy. IEIs are due to genetic abnormalities that disrupt normal host-immune response or immune regulation. The microbiome appears essential for maintaining host immunity, especially in patients with a defective immune system. Altered gut microbiota in patients with IEI can lead to clinical symptoms. Microbial dysbiosis is the consequence of an increase in pro-inflammatory bacteria or a reduction in anti-inflammatory bacteria. However, functional and compositional differences in microbiota are also involved. Dysbiosis and a reduced alpha-diversity are well documented, particularly in conditions like common variable immunodeficiency. Deranged microbiota is also seen in Wiskott–Aldrich syndrome, severe combined immunodeficiency, chronic granulomatous disease, selective immunoglobulin-A deficiency, Hyper IgE syndrome (HIGES), X-linked lymphoproliferative disease-2, immunodysregulation, polyendocrinopathy, enteropathy, x-linked syndrome, and defects of IL10 signalling. Distinct gastrointestinal, respiratory, and cutaneous symptoms linked to dysbiosis are seen in several IEIs, emphasizing the importance of microbiome identification. In this study, we discuss the processes that maintain immunological homeostasis between commensals and the host and the disruptions thereof in patients with IEIs. As the connection between microbiota, host immunity, and infectious illnesses is better understood, microbiota manipulation as a treatment strategy or infection prevention method would be more readily employed. Therefore, optimal prebiotics, probiotics, postbiotics, and fecal microbial transplantation can be promising strategies to restore the microbiota and decrease disease pathology in patients with IEIs

Primary splenic angiosarcoma with liver metastasis: A rare neoplasm diagnosed on fine-needle aspiration cytology and cell block immunocytochemistry

Primary splenic angiosarcoma is a rare malignant vascular neoplasm of mesenchymal origin. The tumor is highly aggressive and has a high metastatic potential. It is usually diagnosed on histopathological examination of splenectomy specimen. Only few cases of angiosarcoma diagnosed by fine-needle aspiration (FNA) cytology alone have been reported in the literature. The cytologic features of angiosarcoma are heterogeneous, however, diagnosis can be suggested by FNA when vasoformative features are present. A 55-year-old female presented with abdominal pain and hepatosplenomegaly. Computed tomography scan revealed a heterogeneous splenic lesion with liver metastases. FNA from the splenic and liver lesions showed moderately pleomorphic tumor cells closely associated with anastomosing vascular channels. Cell block immunocytochemistry (ICC) showed tumor cells positive for CD31, CD34, CD68 as well as for CD99. FNA supplemented by cell block ICC can render a definite diagnosis of primary splenic angiosarcoma with liver metastasis

TUT0201 Course Replication of Diener, E., Ng, W., Harter, J., & Arora, R. (2010). - University of Toronto W19

This is a statistics course-based replication of Diener et al (2010) under the guidance of Professor Molly Metz at the University of Toronto. 20 student groups will each be responsible for sampling, data analysis, and reporting