Corrigendum: Cancer Cell Mitochondria Targeting by Pancratistatin Analogs is Dependent on Functional Complex II and III.

This corrects the article DOI: 10.1038/srep42957.

Exploiting mitochondrial and oxidative vulnerabilities with a synthetic analog of pancratistatin in combination with piperlongumine for cancer therapy.

Harsh adverse effects as a result of nonspecific targeting of chemotherapeutics currently pose obstacles in cancer therapy; thus, it would be invaluable to devise novel approaches to specifically target cancer cells. The natural compound pancratistatin (PST) has been shown to preferentially induce apoptosis in a variety of cancer cell types. Recently, several analogs of PST were shown to be efficacious in inducing apoptosis in a variety of aggressive cancer cell types via cancer cell mitochondrial targeting; it caused dissipation of mitochondrial membrane potential and decreased oxygen consumption, and with isolated mitochondria, it induced the release of apoptogenic factors. The natural compound piperlongumine has been shown to target the stress response to reactive oxygen species in cancer cells. We explored the combinatorial potential of two small molecules (SVTH-6 and piperlongumine) that target these vulnerabilities in cancer cells. Interestingly, when combined with the PST analog, SVTH-6, an increase in mitochondrial dysfunction was observed, leading to an enhanced cytotoxic effect against several human cancer cell types. Additionally, this combination treatment was effective in reducing cancer cell growth in physiologically more relevant 3-dimensional spheroid cell cultures. This enhanced effect was found to be dependent on reactive oxygen species generation because an antioxidant could rescue cancer cells from this combination treatment. Importantly, noncancerous cells were markedly less sensitive to this combination treatment. Thus, targeting mitochondrial and oxidative stress vulnerabilities of cancer cells could be an effective strategy for cancer therapy.-Ma, D., Gilbert, T., Pignanelli, C., Tarade, D., Noel, M., Mansour, F., Gupta, M., Ma, S., Ropat, J., Curran, C., Vshyvenko, S., Hudlicky, T., Pandey. S. Exploiting mitochondrial and oxidative vulnerabilities with a synthetic analog of pancratistatin in combination with piperlongumine for cancer therapy.

Selective Targeting of Cancer Cells by Oxidative Vulnerabilities with Novel Curcumin Analogs.

Recently, research has focused on targeting the oxidative and metabolic vulnerabilities in cancer cells. Natural compounds like curcumin that target such susceptibilities have failed further clinical advancements due to the poor stability and bioavailability as well as the need of high effective doses. We have synthesized and evaluated the anti-cancer activity of several monocarbonyl analogs of curcumin. Interestingly, two novel analogs (Compound A and I) in comparison to curcumin, have increased chemical stability and have greater anti-cancer activity in a variety of human cancer cells, including triple-negative, inflammatory breast cancer cells. In particular, the generation of reactive oxygen species was selective to cancer cells and occurred upstream of mitochondrial collapse and execution of apoptosis. Furthermore, Compound A in combination with another cancer-selective/pro-oxidant, piperlongumine, caused an enhanced anti-cancer effect. Most importantly, Compound A was well tolerated by mice and was effective in inhibiting the growth of human triple-negative breast cancer and leukemia xenografts in vivo when administered intraperitoneally. Thus, exploiting oxidative vulnerabilities in cancer cells could be a selective and efficacious means to eradicate malignant cells as demonstrated by the curcumin analogs presented in this report with high therapeutic potential.

Cancer Cell Mitochondria Targeting by Pancratistatin Analogs is Dependent on Functional Complex II and III.

Enhanced mitochondrial stability and decreased dependence on oxidative phosphorylation confer an acquired resistance to apoptosis in cancer cells, but may present opportunities for therapeutic intervention. The compound pancratistatin (PST) has been shown to selectively induce apoptosis in cancer cells. However, its low availability in nature has hindered its clinical advancement. We synthesized PST analogs and a medium-throughput screen was completed. Analogs SVTH-7, -6, and -5 demonstrated potent anti-cancer activity greater than PST and several standard chemotherapeutics. They disrupted mitochondrial function, activated the intrinsic apoptotic pathway, and reduced growth of tumor xenografts in vivo. Interestingly, the pro-apoptotic effects of SVTH-7 on cancer cells and mitochondria were abrogated with the inhibition of mitochondrial complex II and III, suggesting mitochondrial or metabolic vulnerabilities may be exploited by this analog. This work provides a scaffold for characterizing distinct mitochondrial and metabolic features of cancer cells and reveals several lead compounds with high therapeutic potential.

Cymbopogon citratus and Camellia sinensis extracts selectively induce apoptosis in cancer cells and reduce growth of lymphoma xenografts in vivo.

Cancer cells are reported to have elevated levels of reactive oxygen species (ROS) and are highly dependent on cellular defense mechanisms against oxidative stress. Numerous nutraceuticals and natural polyphenolic compounds have a wide range of abilities to alter cellular redox states with potential implications in various diseases. Furthermore, therapeutic options for cancers are mostly nonselective treatments including genotoxic or tubulin-targeting compounds. Some of the natural extracts, containing multiple bioactive compounds, could target multiple pathways in cancer cells to selectively induce cell death. Cymbopogon citratus (lemongrass) and Camellia sinensis (white tea) extracts have been shown to have medicinal properties, however, their activity against lymphoma and leukemia, as well as mechanistic details, have not been fully characterized. Herein, we report potent anti-cancer properties in dose and time-dependent manners of ethanolic lemongrass and hot water white tea extracts in lymphoma and leukemia models. Both extracts were able to effectively induce apoptosis selectively in these human cancer cell types. Interestingly, ethanolic lemongrass extract induces apoptosis primarily by the extrinsic pathway and was found to be dependent on the generation of ROS. Conversely, apoptotic induction by hot water white tea extract was independent of ROS. Furthermore, both of these extracts caused mitochondrial depolarization and decreased rates of oxygen consumption in lymphoma and leukemia cells, leading to cell death. Most importantly, both these extracts were effective in reducing tumor growth in human lymphoma xenograft models when administered orally. Thus, these natural extracts could have potential for being nontoxic alternatives for the treatment of cancer.

Quality improvement practices to institutionalize supply chain best practices for iCCM: Evidence from Rwanda and Malawi.

BACKGROUND: Supply chain bottlenecks that prevent community health workers (CHWs) from accessing essential medicines significantly increase under-5 child mortality, particularly in poor and rural areas. OBJECTIVE: Using implementation research, interventions aimed at improving supply chain practices and access to medicines were tested in Malawi and Rwanda. These interventions included simple demand-based resupply procedures, using mobile technology and traditional methods for communication, and multilevel, performance-driven quality improvement (QI) teams. METHODS: Mixed-method evaluations were conducted at baseline (2010), midline (2013), and endline (2014). Baseline assessments identified common bottlenecks and established performance levels. Midline assessments identified which intervention package had the greatest impact. Endline surveys measured the progress of scale-up and institutionalization of each innovation. RESULTS: In both Rwanda and Malawi CHWs, health center staff, and district managers all cited many benefits of the establishment of resupply procedures and QI teams: such as providing structure and processes, a means to analyze and discuss problems and enhance collaboration between staff. CONCLUSIONS: Implementing simple, streamlined, demand-based resupply procedures formed the basis for informed and regular resupply, and increased the visibility of appropriate and timely community logistics data. QI teams played a critical role in reinforcing resupply procedures and routinely unlocking the bottlenecks that prevent the continuous flow of critical health products. While simple, streamlined, demand-based resupply procedures provide the basis for regular, functional, and efficient resupply of CHWs, the procedures alone are not sufficient to create consistent change in product availability. Supporting these procedures with multilevel QI teams reinforces the correct and consistent use of resupply procedures.

Making products available among community health workers: Evidence for improving community health supply chains from Ethiopia, Malawi, and Rwanda.

BACKGROUND: A UNICEF review of the challenges to scaling up integrated community case management (iCCM) found that drug shortages were a common bottleneck. In many settings, little thought has gone into the design of supply chains to the community level and limited evidence exists for how to address these unique challenges. SC4CCM's purpose was to conduct intervention research to identify proven, simple, affordable solutions that address the unique supply chain challenges faced by CHWs and to demonstrate that supply chain constraints at the community level can be overcome. METHODS: SC4CCM selected three countries to implement supply chain innovations and developed a theory of change (TOC) framework for the learning phase, which identified the main drivers of product availability and was used for baseline assessments, design, implementation and evaluation of interventions in Ethiopia, Malawi, and Rwanda. Interventions were developed in each country and tested over 12-24 months. Mixed-method follow up assessments were conducted in each country in 2012-2013. The Supply Chain for Community Case Management (SC4CCM) Project then simplified the TOC into a Community Health Supply Chain (CHSC) framework to enable cross country analysis. RESULTS: The findings from interventions in the three countries suggest that the greatest supply chain benefits are realized when all three CHSC framework elements (data flow, product flow, and effective people) are in place and working together. The synergistic effect of these three elements on supply chain performance was most effectively demonstrated by results from the Enhanced Management and Quality Collaborative interventions in Malawi and Rwanda, respectively, which were characterized by lower mean stockout rates and higher in stock rates on day of visit, when compared to other interventions. CONCLUSIONS: Many conditions are necessary to ensure continuous product availability at the community level, however a supply chain works best when three key elements (product flow, data flow, and effective people) are deliberately included as an integral part of the system design. Although these elements may be designed differently in different settings, streamlining and synchronizing them while ensuring inclusion of all components for each element improves supply chain performance and promotes product availability at the community level.

Strengthening community health supply chain performance through an integrated approach: Using mHealth technology and multilevel teams in Malawi.

BACKGROUND: In 2010, 7.6 million children under five died globally - largely due to preventable diseases. Majority of these deaths occurred in sub-Saharan Africa. As a strategy to reduce child mortality, the Government of Malawi, in 2008, initiated integrated community case management allowing health surveillance assistants (HSAs) to treat sick children in communities. Malawi however, faces health infrastructure challenges, including weak supply chain systems leading to low product availability. A baseline assessment conducted in 2010 identified data visibility, transport and motivation of HSAs as challenges to continuous product availability. The project designed a mHealth tool as part of two interventions to address these challenges. METHODS: A mobile health (mHealth) technology - cStock, for reporting on community stock data - was designed and implemented as an integral component of Enhanced Management (EM) and Efficient Product Transport (EPT) interventions. We developed a feasibility and acceptability framework to evaluate the effectiveness and predict the likelihood of scalability and ownership of the interventions. Mixed methods were used to conduct baseline and follow up assessments in May 2010 and February 2013, respectively. Routine monitoring data on community stock level reports, from cStock, were used to analyze supply chain performance over 18-month period in the intervention groups. RESULTS: Mean stock reporting rate by HSAs was 94% in EM group (n = 393) and 79% in EPT group (n = 253); mean reporting completeness was 85% and 65%, respectively. Lead time for HSA drug resupply over the 18-month period was, on average, 12.8 days in EM and 26.4 days in EPT, and mean stock out rate for 6 tracer products was significantly lower in EM compared to EPT group. CONCLUSIONS: Results demonstrate that cStock was feasible and acceptable to test users in Malawi, and that based on comparison with the EPT group, the team component of the EM group was an essential pairing with cStock to achieve the best possible supply chain performance and supply reliability. Establishing multi-level teams serves to connect HSAs with decision makers at higher levels of the health system, align objectives, clarify roles and promote trust and collaboration, thereby promoting country ownership and scalability of a cStock-like system.

Factors affecting availability of essential medicines among community health workers in Ethiopia, Malawi, and Rwanda: solving the last mile puzzle.

To understand how supply chain factors affect product availability at the community level, the Improving Supply Chains for Community Case Management of Pneumonia and Other Common Diseases of Childhood Project developed a theory of change (TOC) framework for gathering, organizing, and interpreting evidence about supply constraints to community case management (CCM). Baseline assessments in Ethiopia, Malawi, and Rwanda conducted in 2010 provided information on the strengths and weaknesses of existing CCM supply chains for five main products: antibiotics for pneumonia, oral rehydration solution, ready to use therapeutic food, zinc, and artemether/lumefantrine. The assessments tested the strength and validity of causal pathways identified in the TOC that were believed to influence availability of CCM products among community health workers (CHWs) for treating common childhood illnesses. Results of the assessments showed product availability to be weak in each country, with more than half of CHWs stocked out of at least one tracer product on the day of the assessment. This report will focus on the findings related to three key preconditions of the TOC and how these were used to inform the design of the CCM supply chain improvement strategy in each country. The three key preconditions include product availability at CHW resupply points, supply chain knowledge and capacity among CHWs and their supervisors, and availability of appropriate transportation.

Gonadotropin-releasing hormone neuroterminals and their microenvironment in the median eminence: effects of aging and estradiol treatment.

The GnRH decapeptide controls reproductive function through its release from neuroendocrine terminals in the median eminence, a site where there is a convergence of numerous nerve terminals and glial cells. Previous work showed dynamic changes in the GnRH-glial-capillary network in the median eminence under different physiological conditions. Because aging in rats is associated with a diminution of GnRH release and responsiveness to estradiol feedback, we examined effects of age and estradiol treatment on these anatomical interactions. Rats were ovariectomized at young (4 months), middle-aged (11 months), or old (22-23 months) ages, allowed 4 wk to recover, and then treated with vehicle or estradiol for 72 h followed by perfusion. Immunofluorescence of GnRH was measured, and immunogold electron microscopic analyses were performed to study the ultrastructural properties of GnRH neuroterminals and their microenvironment. Although the GnRH immunofluorescent signal showed no significant changes with age and estradiol treatment, we found that the median eminence underwent both qualitative and quantitative structural changes with age, including a disorganization of cytoarchitecture with aging and a decrease in the apposition of GnRH neuroterminals to glia with age and estradiol treatment. Thus, although GnRH neurons can continue to synthesize and transport peptide, changes in the GnRH neuroterminal-glial-capillary machinery occur during reproductive senescence in a manner consistent with a disconnection of these elements and a potential dysregulation of GnRH neurosecretion.