Sun, Zhong

Importance Elevated low-density lipoprotein cholesterol (LDL-C) is a modifiable risk factor for cardiovascular disease, the leading cause of premature death worldwide. Assessing the LDL-C–related burden is critical for guiding prevention and treatment strategies. Objectives To estimate the global, regional, and national burden of ischemic heart disease and ischemic stroke attributable to elevated LDL-C (relative to 35-54 mg/dL) from 1990 to 2023 and to quantify the contributions of population growth, aging, risk-deleted burden, and exposure changes to burden trends. Design, Setting, and Population This comparative risk assessment, part of the Global Burden of Disease Study 2023, estimated population-level LDL-C exposure and associated health loss in 204 countries and territories. Mean LDL-C levels were estimated using spatiotemporal gaussian process regression based on 806 studies across 161 countries. Relative risks were derived from meta-analyses of 38 randomized clinical trials. Population-attributable fractions for deaths and disability-adjusted life-years (DALYs) were estimated by age and sex for adults aged 25 years or older from 1990 to 2023, with 95% uncertainty intervals. Exposure Population-level LDL-C concentrations. Main Outcomes and Measures Population-attributable fractions, counts, and rates (all ages and age standardized per 100 000) of LDL-C–attributable deaths and DALYs from ischemic heart disease and ischemic stroke, with uncertainty intervals. Results In 2023, elevated LDL-C accounted for 3.6 million deaths (95% uncertainty interval, 2.2-5.4 million; 6.0% of global mortality) and 90.7 million DALYs (95% uncertainty interval, 58.9-123.3 million; 3.2% of DALYs). Although global all-ages rates remained stable, age-standardized death and DALY rates decreased by 45.6% and 39.5%, respectively, since 1990. In 2023, age-standardized LDL-C–attributable DALY rates were highest in Eastern Europe and lowest in high-income Asia-Pacific. One-third of the global LDL-C burden occurred in India and China. Population growth and aging drove the increasing burden, with notable regional disparities in LDL-C exposure and risk-deleted DALY rates shifting toward middle-sociodemographic settings. Conclusions and Relevance Despite declining age-standardized rates, the absolute LDL-C burden has increased since 1990 due to demographic changes and has shifted toward middle-sociodemographic countries. Measurement and surveillance gaps persist. Strengthened prevention, diagnosis, and treatment access strategies are essential to mitigate the health burden of LDL-C.

Importance Nontraumatic subarachnoid hemorrhage (SAH) represents the third most common stroke type with unique etiologies, risk factors, diagnostics, and treatments. Nevertheless, epidemiological studies often cluster SAH with other stroke types leaving its distinct burden estimates obscure. Objective To estimate the worldwide burden of SAH. Design, Setting, and Participants Based on the repeated cross-sectional Global Burden of Disease (GBD) 2021 study, the global burden of SAH in 1990 to 2021 was estimated. Moreover, the SAH burden was compared with other diseases, and its associations with 14 individual risk factors were investigated with available data in the GBD 2021 study. The GBD study included the burden estimates of nontraumatic SAH among all ages in 204 countries and territories between 1990 and 2021. Exposures SAH and 14 modifiable risk factors. Main Outcomes and Measures Absolute numbers and age-standardized rates with 95% uncertainty intervals (UIs) of SAH incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) as well as risk factor–specific population attributable fractions (PAFs). Results In 2021, the global age-standardized SAH incidence was 8.3 (95% UI, 7.3-9.5), prevalence was 92.2 (95% UI, 84.1-100.6), mortality was 4.2 (95% UI, 3.7-4.8), and DALY rate was 125.2 (95% UI, 110.5-142.6) per 100 000 people. The highest burden estimates were found in Latin America, the Caribbean, Oceania, and high-income Asia Pacific. Although the absolute number of SAH cases increased, especially in regions with a low sociodemographic index, all age-standardized burden rates decreased between 1990 and 2021: the incidence by 28.8% (95% UI, 25.7%-31.6%), prevalence by 16.1% (95% UI, 14.8%-17.7%), mortality by 56.1% (95% UI, 40.7%-64.3%), and DALY rate by 54.6% (95% UI, 42.8%-61.9%). Of 300 diseases, SAH ranked as the 36th most common cause of death and 59th most common cause of DALY in the world. Of all worldwide SAH-related DALYs, 71.6% (95% UI, 63.8%-78.6%) were associated with the 14 modeled risk factors of which high systolic blood pressure (population attributable fraction [PAF] = 51.6%; 95% UI, 38.0%-62.6%) and smoking (PAF = 14.4%; 95% UI, 12.4%-16.5%) had the highest attribution. Conclusions and Relevance Although the global age-standardized burden rates of SAH more than halved over the last 3 decades, SAH remained one of the most common cardiovascular and neurological causes of death and disabilities in the world, with increasing absolute case numbers. These findings suggest evidence for the potential health benefits of proactive public health planning and resource allocation toward the prevention of SAH.

Abstract Background: Hypusine is a unique amino acid present in all eukaryotes but found in only one highly conserved protein, eukaryotic translation initiation factor 5A. It is formed during a two-step post-translational modification of eIF5A. eIF5A has been identified as a critical factor for cell proliferation in yeast, as a modulator of p53, and recent studies indicate that the unhypusinated form of eIF5A is a pro-apoptotic protein. Because myeloma remains incurable, we hypothesized that induction of apoptosis by modulation of eIF5A may be a useful therapeutic approach. In this study we utilized PEI nanoparticles to deliver plasmid DNA and siRNA to myeloma tumor cells in vitro and in vivo. Methods: An siRNA was used to suppress levels of endogenous hypusinated eIF5A in tumors while an RNAi-resistant plasmid expressing a mutant of eIF5A (eIF5AK50R), that cannot be hypusinated, was used to increase levels of unhypusinated eIF5A which is proapoptotic. In vitro, KAS-6/1 myeloma cells were incubated with control siRNA/control plasmid, eIF5A siRNA alone, or eIF5A siRNA/eIF5AK50R for 72 hours in the presence or absence of IL-6. Apoptosis was quantitated using flow cytometry to detect annexin V/propidium iodide stained cells; results were corrected for percent apoptosis of the mock control to enable comparison between experiments. In vivo, SCID mice (3/group) were injected with 10 million KAS-6/1 cells SQ in the right flank and approximately 6 weeks later injected intratumorally twice weekly as follows: Group 1 control mice received 20 μg empty vector and 10 μg control siRNA. Group 2 received 20 μg eIF5AK50R plasmid and 10 μg control siRNA. Group 3 received 20 μg eIF5AK50R plasmid and 10 μg eIF5A siRNA. Tumor volumes were quantitated in mm3 using a2b/2 where a is the smaller dimension. Results: The in vitro results showed the following % apoptosis: Absence of IL-6 - Control: 6.5%, eIF5A siRNA/eIF5AK50R 30.3%. Presence of IL-6–Control:8.2%; eIF5A siRNA alone 36.5%; eIF5A siRNA/eIF5AK50R 45.2%. Western analysis demonstrated that the siRNA successfully inhibited the production of endogenous eIF5A. In vivo, after 24 days of monitoring tumor volume: group 1 mice showed that the KAS-6/1 cells grew from a mean tumor volume of 7±1 up to 102±16 mm3; tumors in group 2 mice remained relatively stable in size from 21±9 to 26±10 mm3. Group 3 mice showed a mean 92% tumor regression from 99±21 down to 7±1 mm3. Conclusions: Delivery of eIF5A siRNA and eIF5AK50R plasmid by PEI nanoparticles results in significant anti-tumoral reponses in vitro and in vivo. These studies may provide a novel therapy for myeloma patients with end stage disease that have failed standard treatments.

Abstract Abstract 2462 Poster Board II-439 The eukaryotic translation initiation factor 5A (eIF5A) is highly conserved and the only known protein to contain the amino acid hypusine. Hypusinated eIF5A and deoxyhypusine synthase, one of the enzymes mediating eIF5A post-translational hypusination, have been identified as markers of neoplastic growth and metastasis, respectively. However, recent studies have indicated that, in its unhypusinated form, eIF5A is pro-apoptotic and thus functionally distinct from hypusine-modified eIF5A. SNS01 is a cancer gene therapy biologic targeted to the treatment of multiple myeloma. SNS01 is comprised of three components: a DNA vector containing a B-cell-specific (B29) promoter driving expression of a pro-apoptotic mutant of eIF5A (eIF5AK50R) that cannot be hypusinated; an siRNA that targets the native hypusinated eIF5A that promotes growth of cancer cells; and a synthetic polymer called polyethylenimine (PEI). RT-qPCR experiments demonstrated that treatment of the human myeloma cell line, KAS-6/1, with SNS01 results in a 90 % reduction in the expression of eIF5A mRNA (mediated by the siRNA) as well as the accumulation of ∼ 22,000 copies of the plasmid-derived eIF5AK50R mRNA per ng of total RNA. SNS01 was found to induce apoptosis in both IL-6-dependent (KAS-6/1) and IL-6-independent (U266) myeloma cell lines and was found to be more effective at inducing apoptosis than PEI nanoparticles carrying either the eIF5A siRNA or the eIF5AK50R plasmid alone. Apoptosis assays were used to optimize the ratio of DNA:siRNA in the nanoparticles and a ratio of 2:1 was found to be optimal for the induction of apoptosis in myeloma cells. The anti-tumoral activity of SNS01 was assessed in SCID mice bearing subcutaneous human multiple myeloma (KAS-6/1) tumors using twice-weekly intra-venous injections and a dose range between 0.15 mg/kg and 1.5 mg/kg. Control mice treated with PEI nanoparticles containing a non-expressing plasmid and a non-targeting siRNA had an average tumor volume of 284 mm3 at the time of sacrifice, whereas mice treated with 1.5 mg/kg or 0.75 mg/kg SNS01 exhibited significant tumor regression and had average tumor volumes of 13 mm3 (95 % inhibition; *p = 0.026) and 24.5 mm3 (91 % inhibition; *p = 0.03), respectively. In addition, for mice treated with 1.5 mg/kg SNS01, there was no evidence of tumors under the skin. Lower doses of SNS01 also demonstrated anti-tumoral activity with mice treated with 0.38 mg/kg and 0.15 mg/kg exhibiting a 73 % and 61 % inhibition of tumor growth, respectively. TUNEL-labeling revealed evidence of apoptotic cells in the treated tumors indicating that tumor regression occurs through the induction of apoptosis. Twice weekly dosing of SNS01 was found to be critical for effective tumor control. In a separate study, twice weekly dosing of SNS01 at 1.5 mg/kg was found to inhibit tumor growth by 88 % (p = 0.01) while once weekly dosing did not significantly reduce tumor burden. Since SNS01 is intended as a therapy for multiple myeloma, a bone marrow neoplasm, the biodistribution of PEI nanoparticles containing a GFP plasmid with the B-cell-specific B29 promoter and a fluorescently (DY547)-labeled siRNA was assessed following i.v. administration in Balb/c mice. The fluorescent siRNA was observed in the liver, lung, spleen, and bone marrow, while GFP expression was primarily observed in the bone marrow. In summary, our preclinical data indicate that systemic administration of SNS01 is an effective anti-cancer therapy in an animal model of multiple myeloma. Additionally, since PEI nanoparticles are taken up by cells of the bone marrow following systemic delivery, SNS01 may be an effective treatment option for multiple myeloma patients and is currently being evaluated for use in clinical trials. Disclosures: Taylor: Senesco Technologies Inc.: Patents & Royalties, stock options. Lust:Senesco Technologies Inc.: Research Funding. Dondero:Senesco Technologies Inc.: Employment, Equity Ownership, Patents & Royalties. Galton:Senesco Technologies Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Donovan:Senesco Technologies Inc.: Research Funding. Thompson:Senesco Technologies Inc.: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

Abstract Introduction: The eukaryotic translation initiation factor 5A (eIF5A) is the only known protein to be regulated by post-translational addition of a hypusine residue. Both hypusinated eIF5A and the enzyme that mediates eIF5A hypusination have been identified as markers of neoplastic growth and metastasis. However, recent studies have indicated that, in its unhypusinated form, eIF5A is pro-apoptotic and thus functionally distinct from hypusine-modified eIF5A. In vitro cell studies and in vivo xenograft studies have demonstrated that simultaneous suppression of eIF5A expression and overexpression of a non-hypusinable mutant of eIF5A potently induces apoptosis in multiple cancer cell types. SNS01 is a nanoparticle specifically designed for the treatment of multiple myeloma. SNS01 is comprised of three components: a DNA vector containing a B-cell-specific (B29) promoter driving expression of a pro-apoptotic mutant of eIF5A (eIF5AK50R) that cannot be hypusinated; an siRNA that targets the native hypusinated eIF5A that promotes growth of cancer cells; and a synthetic polymer called polyethylenimine (PEI). Methods: Ethidium-bromide agarose gel electrophoresis was used to detect heparin-mediated release of nucleic acids from nanoparticles. Dynamic light scattering (DLS) was used to assess the short-term stability of SNS01 by monitoring changes in size distribution, polydispersity, and zeta potential. In vitro biological activity of SNS01 was assessed using RT-qPCR to measure eIF5A and eIF5AK50R transgene expression as well as FACS detection of AnnexinV-FITC labeled apoptotic cells. Anti-tumoral activity of SNS01 was evaluated using a subcutaneous human myeloma model (KAS-6/1 cells) in SCID mice with twice-weekly intra-venous injections of SNS01. Results: SNS01 nanoparticles were found to be relatively stable for as long as 48 hours at room temperature with no significant loss in nucleic acid integrity. The nanoparticles had an average diameter of 146.2 nm, a polydispersity of 0.287 and an average zeta potential of 35.3+0.7 mV. These parameters were quite stable over 48 hours. SNS01 could also be frozen at − 80°C for at least one month with no observable loss in biological activity. Twice-weekly intra-venous injections into myeloma tumor-bearing mice of a frozen SNS01 preparation was found to have anti-tumoral activity comparable to freshly prepared SNS01 (frozen SNS01: 89 % tumor inhibition, p = 0.00158; SNS01: 84 % tumor inhibition, p = 0.00003). Conclusions: SNS01 is relatively stable at room temperature and was also found to be stable and biologically active following freezing. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A196.