Long-Term Effects of the Synergistic Interaction of Cisplatin and Noise

As cancer treatments advance, more patients survive each year. Of these survivors, many have experienced treatment with chemotherapeutic drugs like cisplatin that have aided in and enabled their recovery. Cisplatin, a chemotherapeutic drug used to combat head, neck, and urological cancers, is highly ototoxic and causes significant high-frequency cochlear hearing loss, as well as increased susceptibility to noise damage, leading to even more severe hearing losses. The current study assessed whether rats that have been exposed to cisplatin see potentiated noise-induced hearing loss, and determined if the increased susceptibility to noise damage lasts for a period of time after the cisplatin treatment interval. The study found that subjects’ susceptibility to noise damage was still increased even four months after the end of cisplatin treatment, suggesting that the effects of this drug can last longer than only the duration of the drug administration itself. Further, the rats involved in this study experienced potentiated losses in frequencies indirectly affected by cisplatin (10, 15, and 20 kHz), indicating that the entirety of the cochlea was affected by the drug, and not merely the high frequencies. Further study is required to evaluate the clinical ramifications of these findings in humans and to develop appropriate counseling strategies to combat these effects, but the results provide an initial indication that clinical patients who have been administered cisplatin need to be educated on the long-term need for hearing protection from noise to avoid further hearing damage.Pelotonia Undergraduate FellowshipOffice of Undergraduate Research Summer FellowshipCollege of Arts and Sciences Research AwardDepartment of Social and Behavioral Sciences Research GrantUndergraduate Student Government Travel AwardNo embargoAcademic Major: Speech and Hearing Scienc

Heavily and Fully Modified RNAs Guide Efficient SpyCas9-Mediated Genome Editing [preprint]

RNA-based drugs depend on chemical modifications to increase potency and nuclease stability, and to decrease immunogenicity in vivo. Chemical modification will likely improve the guide RNAs involved in CRISPR-Cas9-based therapeutics as well. Cas9 orthologs are RNA-guided microbial effectors that cleave DNA. No studies have yet explored chemical modification at all positions of the crRNA guide and tracrRNA cofactor. Here, we have identified several heavily-modified versions of crRNA and tracrRNA that are more potent than their unmodified counterparts. In addition, we describe fully chemically modified crRNAs and tracrRNAs (containing no 2\u27-OH groups) that are functional in human cells. These designs demonstrate a significant breakthrough for Cas9-based therapeutics since heavily modified RNAs tend to be more stable in vivo (thus increasing potency). We anticipate that our designs will improve the use of Cas9 via RNP and mRNA delivery for in vivo and ex vivo purposes

Heavily and fully modified RNAs guide efficient SpyCas9-mediated genome editing

RNA-based drugs depend on chemical modifications to increase potency and to decrease immunogenicity in vivo. Chemical modification will likely improve the guide RNAs involved in CRISPR-Cas9-based therapeutics as well. Cas9 orthologs are RNA-guided microbial effectors that cleave DNA. Here, we explore chemical modifications at all positions of the crRNA guide and tracrRNA cofactor. We identify several heavily modified versions of crRNA and tracrRNA that are more potent than their unmodified counterparts. In addition, we describe fully chemically modified crRNAs and tracrRNAs (containing no 2\u27-OH groups) that are functional in human cells. These designs will contribute to Cas9-based therapeutics since heavily modified RNAs tend to be more stable in vivo (thus increasing potency). We anticipate that our designs will improve the use of Cas9 via RNP and mRNA delivery for in vivo and ex vivo purposes

FRA2A is a CGG repeat expansion associated with silencing of AFF3

Folate-sensitive fragile sites (FSFS) are a rare cytogenetically visible subset of dynamic mutations. Of the eight molecularly characterized FSFS, four are associated with intellectual disability (ID). Cytogenetic expression results from CGG tri-nucleotide-repeat expansion mutation associated with local CpG hypermethylation and transcriptional silencing. The best studied is the FRAXA site in the FMR1 gene, where large expansions cause fragile X syndrome, the most common inherited ID syndrome. Here we studied three families with FRA2A expression at 2q11 associated with a wide spectrum of neurodevelopmental phenotypes. We identified a polymorphic CGG repeat in a conserved, brain-active alternative promoter of the AFF3 gene, an autosomal homolog of the X-linked AFF2/FMR2 gene: Expansion of the AFF2 CGG repeat causes FRAXE ID. We found that FRA2A-expressing individuals have mosaic expansions of the AFF3 CGG repeat in the range of several hundred repeat units. Moreover, bisulfite sequencing and pyrosequencing both suggest AFF3 promoter hypermethylation. cSNP-analysis demonstrates monoallelic expression of the AFF3 gene in FRA2A carriers thus predicting that FRA2A expression results in functional haploinsufficiency for AFF3 at least in a subset of tissues. By whole-mount in situ hybridization the mouse AFF3 ortholog shows strong regional expression in the developing brain, somites and limb buds in 9.5-12.5dpc mouse embryos. Our data suggest that there may be an association between FRA2A and a delay in the acquisition of motor and language skills in the families studied here. However, additional cases are required to firmly establish a causal relationship

Risk Factors for Mycobacterium ulcerans Infection, Southeastern Australia

Epidemiologic evidence shows that mosquitoes play a role in transmission to humans