19 research outputs found
Polymer Micelle Formulation for the Proteasome Inhibitor Drug Carfilzomib: Anticancer Efficacy and Pharmacokinetic Studies in Mice
Carfilzomib (CFZ) is a peptide epoxyketone proteasome inhibitor approved for the treatment of multiple myeloma (MM). Despite the remarkable efficacy of CFZ against MM, the clinical trials in patients with solid cancers yielded rather disappointing results with minimal clinical benefits. Rapid degradation of CFZ in vivo and its poor penetration to tumor sites are considered to be major factors limiting its efficacy against solid cancers. We previously reported that polymer micelles (PMs) composed of biodegradable block copolymers poly(ethylene glycol) (PEG) and poly(caprolactone) (PCL) can improve the metabolic stability of CFZ in vitro. Here, we prepared the CFZ-loaded PM, PEG-PCL-deoxycholic acid (CFZ-PM) and assessed its in vivo anticancer efficacy and pharmacokinetic profiles. Despite in vitro metabolic protection of CFZ, CFZ-PM did not display in vivo anticancer efficacy in mice bearing human lung cancer xenograft (H460) superior to that of the clinically used cyclodextrin-based CFZ (CFZ-CD) formulation. The plasma pharmacokinetic profiles of CFZ-PM were also comparable to those of CFZ-CD and the residual tumors that persisted in xenograft mice receiving CFZ-PM displayed an incomplete proteasome inhibition. In summary, our results showed that despite its favorable in vitroperformances, the current CFZ-PM formulation did not improve in vivo anticancer efficacy and accessibility of active CFZ to solid cancer tissues over CFZ-CD. Careful consideration of the current results and potential confounding factors may provide valuable insights into the future efforts to validate the potential of CFZ-based therapy for solid cancer and to develop effective CFZ delivery strategies that can be used to treat solid cancers
CSF total tau/α-synuclein ratio improved the diagnostic performance for Alzheimers disease as an indicator of tau phosphorylation
Abstract
Background
Recently, several studies suggested potential involvements of α-synuclein in Alzheimers disease (AD) pathophysiology. Higher concentrations of α-synuclein were reported in cerebrospinal fluid (CSF) of AD patients with a positive correlation towards CSF tau, indicating its possible role in AD. We analyzed the CSF biomarkers to verify whether α-synuclein could be an additional supported biomarker in AD diagnosis.
Methods
In this cross-sectional study, CSF samples of 71 early-onset AD, 34 late-onset AD, 11 mild cognitive impairment, 17 subjective cognitive decline, 45 Parkinsons disease, and 32 healthy control (HC) were collected. CSF amyloid-β1-42 (A), total tau (N), and phosphorylated tau181 (T) were measured by commercial ELISA kits, and in-house ELISA kit was developed to quantify α-synuclein. The cognitive assessments and amyloid-PET imaging were also performed.
Results
CSF α-synuclein manifested a tendency to increase in AD and to decreased in Parkinsons disease compared to HC. The equilibrium states of total tau and α-synuclein concentrations were changed significantly in AD, and the ratio of total tau/α-synuclein (N/αS) was dramatically increased in AD than HC. Remarkably, N/αS revealed a strong positive correlation with tau phosphorylation rate. Also, the combination of N/αS with amyloid-β1-42/phosphorylated tau181ratio had the best diagnosis performance (AUC = 0.956, sensitivity = 96%, specificity = 87%). In concordance analysis, N/αS showed the higher diagnostic agreement with amyloid-β1-42 and amyloid-PET. Analysis of biomarker profiling with N/αS had distinctive characteristics and clustering of each group. Especially, among the group of suspected non-Alzheimers disease pathophysiology, all A−T+N+ patients with N/αS+ were reintegrated into AD.
Conclusions
The high correlation of α-synuclein with tau and the elevated N/αS in AD supported the involvement of α-synuclein in AD pathophysiology. Importantly, N/αS improved the diagnostic performance, confirming the needs of incorporating α-synuclein as a biomarker for neurodegenerative disorders. The incorporation of a biomarker group [N/αS] could contribute to provide better understanding and diagnosis of neurodegenerative disorders
IS6110-Restriction Fragment Length Polymorphism and Spoligotyping Analysis of Mycobacterium tuberculosis Clinical Isolates for Investigating Epidemiologic Distribution in Korea
The Beijing family of Mycobacterium tuberculosis has been emerging in the world. However, there are few nationwide data of genotypic distribution in Korea. This study aimed to identify the genotypic diversity of clinical isolates of M. tuberculosis and to demonstrate the population of Beijing family in Korea. We collected 96 clinical M. tuberculosis isolates from 11 university hospitals nationwide in Korea from 2008 to 2009. We observed 24 clusters in IS6110-RFLP analysis and 19 patterns in spoligotyping. Seventy-five isolates were confirmed to be Beijing family. Two isolates of the K strain and 12 isolates of the K family strain were also found. We found that drug resistance phenotypes were more strongly associated with Beijing family than non-Beijing family (P=0.003). This study gives an overview of the distribution of genotypes of M. tuberculosis in Korea. These findings indicate that we have to pay more attention to control of M. tuberculosis strains associated with the Beijing family
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Improving system performance by utilizing heterogeneous memories
As device technologies scale in the nanometer era, the current off-chip DRAM technologies are very close to reaching the physical limits where they cannot scale anymore. In order to continue the memory scaling, vendors are beginning to use new emerging memory technologies such as die-stacked DRAM. Although each type of memory technology has advantages and disadvantages, none has characteristics that are identical to conventional DRAM. For example, High Bandwidth Memory (HBM) has better bandwidth but lower capacity than DRAM whereas non-volatile memories offer more capacity, but are much slower than DRAM. With the emergence of such disparate memory technologies, future memory systems are certain to be heterogeneous where the main memory is composed of two or more types of memory. Recent and current trends show that the number of cores in a processor has been rising constantly. On the other hand, the off-chip DRAM bandwidth has not been scaling at the same rate as the bandwidth is limited mainly by the pin count. This trend has resulted in lower bandwidth per core in today's system where the bandwidth available to each core is lower than the system in the past. This has effectively created the “Bandwidth Wall” where the bandwidth per core does not scale anymore. Consequently, memory vendors are introducing HBM in order to enable the bandwidth scaling. The adoption of such high bandwidth memory and other emerging memory technologies has provided rich opportunities to explore how such heterogeneous main memory systems can be used effectively. In this dissertation, different ways to effectively use such heterogeneous memory systems, especially those containing off-chip DRAM and die-stacked DRAM such as HBM, are presented. First, hardware as well as software driven data management schemes are presented where either hardware or software explicitly migrates data between the two different memories. The hardware managed scheme does not use a fixed granularity migration scheme, but rather migrates variable amount of data between two different memories depending on the memory access characteristics. This approach achieves low off-chip memory bandwidth usage while maintaining a high hit rate in the more desirable memory. Similarly, a software driven scheme varies the migration granularity without any additional hardware support by monitoring the spatial locality characteristics of the running applications. In both solutions, the goal is to migrate just the right amount of data into capacity constrained memory to achieve the low off-chip memory bandwidth usage while still keeping the high hit rate. While the capacity of die-stacked DRAM is not sufficient to meet the demands of a server-class system, it is still non-trivial in size ranging from 8 to 16 GBs in typical configurations, so a fraction of the storage can be used for non-conventional uses such as storing address translations. With increasing deployment of virtual machines for cloud services and server applications, one major contributor of performance overheads in virtualized environments is memory address translation. An application executing on a guest OS generates guest virtual addresses that need to be translated to host physical addresses. In x86 architectures, both the guest and host page tables employ a 4-level radix-tree table organization. Translating a virtual address to physical address takes 4 memory references in a bare metal case using a radix-4 table, and in the virtualized case, it becomes a full 2D translation with up to 24 memory accesses. A method to use a fraction of die-stacked DRAM as a very large TLB is presented in this dissertation, so that almost all page table walks are eliminated. This leads to a substantial performance improvement in virtualized systems where the address translation takes a considerable fraction of execution time.Electrical and Computer Engineerin
Containment Domains: A Scalable, Efficient and Flexible Resilience Scheme for Exascale Systems
This paper describes and evaluates a scalable and efficient resilience scheme based on the concept of containment domains. Containment domains are a programming construct that enable applications to express resilience needs and to interact with the system to tune and specialize error detection, state preservation and restoration, and recovery schemes. Containment domains have weak transactional semantics and are nested to take advantage of the machine and application hierarchies and to enable hierarchical state preservation, restoration and recovery. We evaluate the scalability and efficiency of containment domains using generalized trace-driven simulation and analytical analysis and show that containment domains are superior to both checkpoint restart and redundant execution approaches
Veratramine Inhibits the Cell Cycle Progression, Migration, and Invasion via ATM/ATR Pathway in Androgen-Independent Prostate Cancer
Prostate cancer (PC) is the second leading cause of cancer-related death among men. Treatment of PC becomes difficult after progression because PC that used to be androgen-dependent becomes androgen-independent prostate cancer (AIPC). Veratramine, an alkaloid extracted from the root of the Veratrum genus, has recently been reported to have anticancer effects that work against various cancers; however, its anticancer effects and the underlying mechanism of action in PC remain unknown. We investigated the anticancer effects of veratramine on AIPC using PC3 and DU145 cell lines, as well as a xenograft mouse model. The antitumor effects of veratramine were evaluated using the CCK-8, anchorage-independent colony formation, trans-well, wound healing assays, and flow cytometry in AIPC cell lines. Microarray and proteomics analyses were performed to investigate the differentially expressed genes and proteins induced by veratramine in AIPC cells. A xenograft mouse model was used to confirm the therapeutic response and in vivo efficacy of veratramine. Veratramine dose dependently reduced the proliferation of cancer cells both in vitro and in vivo. Moreover, veratramine treatment effectively suppressed the migration and invasion of PC cells. The immunoblot analysis revealed that veratramine significantly downregulated Cdk4/6 and cyclin D1 via the ATM/ATR and Akt pathways, both of which induce a DNA damage response that eventually leads to G1 phase arrest. In this study, we discovered that veratramine exerted antitumor effects on AIPC cells. We demonstrated that veratramine significantly inhibited the proliferation of cancer cells via G0/G1 phase arrest induced by the ATM/ATR and Akt pathways. These results suggest that veratramine is a promising natural therapeutic agent for AIPC. © 2023 World Scientific Publishing Company.FALS
Jazf1 promotes prostate cancer progression by activating JNK/Slug
Juxtaposed with another zinc finger protein 1 (Jazf1) is a zinc finger protein and is known to affect both prostate cancer and type 2 diabetes. Jazf1 inhibits testicular nuclear receptor 4 (TR4) activation through protein-protein interaction, which results in weight loss and alleviates diabetes. However, the role of Jazf1 in prostate cancer is still poorly understood. Hence, we investigated whether the expression of Jazf1 is associated with prostate cancer progression. We confirmed the upregulation of Jazf1 expression in human prostate tissue samples. In addition, using Jazf1 overexpressing prostate cancer cell lines, DU145 and LNCaP, we found Jazf1 promoted cell proliferation and colony formation ability. We also observed that Jazf1 dramatically enhanced cell migration and invasion in transwell assays. Additionally, we checked the upregulation of vimentin and downregulation of E-cadherin expression in Jazf1- overexpressing DU145 and LNCaP cells. Moreover, we found that Slug, which is known to be regulated by JNK/c-Jun phosphorylation, was upregulated in the microarray analysis of two prostate cancer cell lines. Jazf1 promotes the phosphorylation of JNK/ c-Jun, likely promoting cell proliferation and invasion through Slug. In a xenograft model, tumors overexpressing Jazf1 were larger than control tumors, and tumors with decreased Jazf1 were smaller. These data indicated that Jazf1 enhances prostate cancer progression and metastasis via regulating JNK/Slug signaling. Taken together, these results suggest that Jazf1 plays an important role in both androgen dependent and independent prostate cancer. © Sung et al.1