Folding of the SARS‐CoV‐2 RNA Polymerase by the Cytosolic Chaperonin CCT

The ongoing Covid‐19 pandemic, caused by the highly transmissible SARS‐CoV‐2 virus, constitutes the worst global public health crisis of the past century. Although effective vaccines have been developed, administration has been slow, new variants continue to emerge, and there remains a lack of effective antivirals to treat severe cases. Thus, there remains a significant need to understand the mechanisms of SARS‐CoV‐2 infection and replication to identify new potential therapeutic targets. To this end, we investigated whether SARS‐CoV‐2 might depend on the host cell chaperone system, particularly the essential cytosolic chaperonin, CCT, to fold or assemble any of its proteins. CCT has previously been shown to be required for the replication of several other viruses including reoviruses and zika virus. We screened likely candidates among the SARS‐CoV‐2 proteins for co‐immunoprecipitation with CCT and identified an interaction with the RNA‐dependent RNA polymerase, Nsp12. To confirm Nsp12 was a substrate, we depleted cells of CCT, then transfected with Nsp12 and observed a 40% decrease in Nsp12 expression in CCT‐depleted cells compared to the control. This decrease is consistent with what we have observed for other known CCT substrates. Additionally, CCT‐depleted cells infected with live SARS‐CoV‐2 produced a 50% decrease in viral titer compared to controls, indicating that CCT is important for viral replication. A preliminary cryo‐EM structure of the Nsp12‐CCT complex shows a very large mass identifiable as Nsp12 inside of CCT that extends from the equatorial domains up and out through one of the two folding cavities. The structure stands to both reveal an important step in SARS‐CoV‐2 replication and to answer a long‐standing question regarding how CCT can accommodate very large substrates.

7X multiplexed, optofluidic detection of nucleic acids for antibiotic-resistance bacterial screening

Rapid and accurate diagnosis of bacterial infections resistant to multiple antibiotics requires development of new bio-sensors for differentiated detection of multiple targets. This work demonstrates 7x multiplexed detection for antibiotic-resistance bacterial screening on an optofluidic platform. We utilize spectrally multiplexed multi-spot excitation for simultaneous detection of nucleic acid strands corresponding to bacterial targets and resistance genes. This is enabled by multi-mode interference (MMI) waveguides integrated in an optofluidic device. We employ a combinatorial three-color labeling scheme for the nucleic acid assays to scale up their multiplexing capability to seven different nucleic acids, representing three species and four resistance genes.

Lowering the transmission and spread of human coronavirus

The emergence of the severe acute respiratory syndrome coronavirus 2 pandemic has created an unprecedented healthcare, social, and economic disaster. Wearing of masks and social distancing can significantly decrease transmission and spread, however, due to circumstances such as medical or dental intervention and personal choice these practices have not been universally adopted. Additional strategies are required to lessen transmission. Nasal rinses and mouthwashes, which directly impact the major sites of reception and transmission of human coronaviruses (HCoV), may provide an additional level of protection against the virus. Common over-the-counter nasal rinses and mouthwashes/gargles were tested for their ability to inactivate high concentrations of HCoV using contact times of 30 s, 1 min, and 2 min. Reductions in titers were measured by using the tissue culture infectious dose 50 (TCID₅₀ ) assay. A 1% baby shampoo nasal rinse solution inactivated HCoV greater than 99.9% with a 2-min contact time. Several over-the-counter mouthwash/gargle products including Listerine and Listerine-like products were highly effective at inactivating infectious virus with greater than 99.9% even with a 30-s contact time. In the current manuscript we have demonstrated that several commonly available healthcare products have significant virucidal properties with respect to HCoV.

Ethanol and isopropanol inactivation of human coronavirus on hard surfaces

BACKGROUND

The coronavirus disease 2019 pandemic has greatly increased the frequency of disinfecting surfaces in public places, causing a strain on the ability to obtain disinfectant solutions. An alternative is to use plain alcohols (EtOH and IPA) or sodium hypochlorite (SH).

AIM

To determine the efficacy of various concentrations of EtOH, IPA and SH on a human coronavirus (HCoV) dried on to surfaces using short contact times.

METHODS

High concentrations of infectious HCoV were dried on to porcelain and ceramic tiles, then treated with various concentrations of the alcohols for contact times of 15 s, 30 s and 1 min. Three concentrations of SH were also tested. Reductions in titres were measured using the tissue culture infectious dose 50 assay.

FINDINGS

Concentrations of EtOH and IPA from 62% to 80% were very efficient at inactivating high concentrations of HCoV dried on to tile surfaces, even with a 15-s contact time. Concentrations of 95% dehydrated the virus, allowing infectious virus to survive. The dilutions of SH recommended by the Centers for Disease Control and Prevention (1/10 and 1/50) were efficient at inactivating high concentrations of HCoV dried on to tile surfaces, whereas a 1/100 dilution had substantially lower activity.

CONCLUSIONS

Multiple concentrations of EtOH, IPA and SH efficiently inactivated infectious HCoV on hard surfaces, typical of those found in public places. Often no remaining infectious HCoV could be detected.

The ability of two chlorine dioxide chemistries to inactivate human papillomavirus-contaminated endocavitary ultrasound probes and nasendoscopes

Sexual transmission is the most common pathway for the spread of Human papillomavirus (HPV). However, the potential for iatrogenic HPV infections is also real. Even though cleared by the Food and Drug Administration and recommended by the World Federation for Ultrasound in Medicine and Biology, several disinfectants including glutaraldehyde and o-phthalaldehyde have shown a lack of efficacy for inactivating HPV. Other methods such as ultraviolet C and concentrated hydrogen peroxide have been shown highly effective at inactivating infectious HPV. In this study, two chlorine dioxide systems are also shown to be highly efficacious at inactivating HPV. An important difference in these present studies is that as opposed to testing in suspension or using a carrier, we dried the infectious virus directly onto endocavitary ultrasound probes and nasendoscopes, therefore, validating a more realistic system to demonstrate disinfectant efficacy.

Abstract 5160: Identifying TK1 localization in immortalized placental cell lines and in conditioned placental tissue

Many parallels in growth pattern can be observed between placental and cancer development. In fact, placental trophoblast and cancer cells share similarities in migration and invasion patterns, immune escape strategies, and angiogenesis induction. A common feature of pregnancy complication is aberrant trophoblast behavior. Understanding trophoblast cell behavior can help us identify common patterns in cancer gene and protein regulation. Thymidine kinase 1 (TK1) has been extensively studied as a serum and tissue cancer biomarker. Recently, TK1 has been shown to be upregulated in some cancer tissues and localized on the surface of certain cancer cell lines, and has been suggested as a possible immunotherapeutic target in some cancers. Our goal for this study was to investigate TK1 correlation to placental invasive potential, and therefore establish a function for TK1 localization in these tissues. To do this, we wanted to investigate TK1 placental tissue expression/ localization during normal and obstetric complications and its expression in current placental cell lines. We obtained human placental tissue from various pregnancy conditions including preeclampsia (PE), diabetes (GDM; treated with diet (D) or Insulin (I)) and intrauterine growth restriction (IUGR). For our cell study, immortalized placental cell lines, SW71, JEG-3 and BeWo were used. Immunofluorescence was used for TK1 cell expression in human placental sections. Flow cytometry was performed for TK1 presence in cultured cells. We observed high staining for nuclear and cytosolic expression of TK1 in the control placenta tissues. Compared to controls, there was a marked reduction in TK1 staining in the IUGR and GDM-I placentas which lack nuclear expression of TK1. A decreased for both nuclear and cytosolic TK1 staining, was present in the PE and GDM-D placenta. Flow cytometry showed that SW71 cells had high expression of TK1 on their surface (56%), JEG-3 had low expression of TK1 on their surface (12%), and BeWo cells did not express TK1 on their surface. These findings are interesting because they suggest TK1 surface expression directly correlates with the invasive potential. TK1 protein expression was also measured using standard western blotting techniques to support the data obtained by immunohistochemistry. Furthermore, we established the invasion potential of these placental cell lines using the xCELLigence RTCA DP system between the TK1 positive and negative placenta cell lines. Further confirmation is required; however, these results could assist in understanding the placental/trophoblast invasive mechanism and its correlation in cancer development.

Citation Format: Eliza E. Lawrence, Evita G. Weagel, Juan F. Mejia, Juan Arroyo, Shalee Killpack, Kim L. O'Neill, Richard Robison. Identifying TK1 localization in immortalized placental cell lines and in conditioned placental tissue [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5160.

UVC radiation as an effective disinfectant method to inactivate human papillomaviruses

Endocavitary ultrasound probes are part of a commonly used procedure in the clinical arena. The cavities examined, vaginal canal and cervix, anal canal, and oral cavity are all areas commonly infected with the human papillomavirus (HPV), thus making them susceptible to contamination by HPV. It has been demonstrated that these probes can remain contaminated with high-risk HPV even when approved disinfection protocols have been performed. we have previously shown that HPV is resistant to some high-level disinfectant (HLD). In our present study we analyzed efficacy of using high-level ultra-violet C (UVC) radiation against HPV16 and HPV18 using a hard-surface carrier test. Stocks of infectious authentic HPV16 and HPV18 virions were dried onto carriers with a 5% (v/v) protein soil or 4ppm hard water. Efficacy testing were performed with the automated device, Antigermix S1 device (UVC radiation at 253.7nm) and 0.55% OPA in quadruplicate with matched input, neutralization, and cytotoxicity controls. Hypochlorite was included as a positive control for viral deactivation. Infectivity was determined by the abundance (qRT-PCR) of the spliced E1^E4 transcript in infected recipient cells. The automated Antigermix S1 device showed excellent efficacy against HPV16 and HPV18 whereas OPA showed minimal efficacy. While HPV is highly resistant to OPA, high-level UVC radiation offers an effective disinfection practice for ultrasound probes. Our results suggest that healthcare facilities using endocavitary ultrasound probes need to strongly consider disinfection methods that are effective against HPV.

Abstract 1949: Salvage pathway enzyme HPRT as a molecular marker for Burkitt’s Lymphoma

The aim of this study is to investigate the potential of Hypoxanthine phosphoribosyltransferase (HPRT) as a surface biomarker and target for future immunotherapies in Burkitt’s B-cell Lymphoma. B-cell malignancies are the most common type of childhood cancer. Development of immunotherapies could improve current treatment. HPRT is a cytosolic transferase involved in nucleotide production via the purine salvage pathway. Altered expression of TK1, a salvage pathway enzyme, is an indicator of prognosis and diagnosis in multiple cancer types due to active proliferation of cells and the resulting elevated nucleotide demand. It has previously been reported that some salvage pathway enzymes are found on the surface of Burkitt’s Lymphoma cells. HPRT presence on the surface of this B-cell lymphoma subtype could provide a target for adoptive cell transfer and other immunotherapies. The potential surface presentation of HPRT was assessed using flow cytometry, scanning electron microscopy (SEM), and cytoplasmic staining on both healthy lymphocytes and Burkitt’s Lymphoma cells (Raji). Flow cytometry experiments with HPRT antibodies and fluorescent-labeled secondary antibodies show that Raji cells exhibit an 81.4% (p-value .0001) positive fluorescence shift when compared to IgG controls (1.5%). Healthy lymphocytes had a fluorescence shift of 2.38% (p-value .9787). The presence of HPRT on the surface of both Raji cells and healthy lymphocytes was further confirmed using gold-labeled antibodies. Utilizing a scanning electron microscope, the presence of the protein on the surface was evaluated and quantified via increases in gold weight percentage of the sample. When treated with antibodies against HPRT, there was a significant increase in gold binding along with an increase in gold weight percentage. These results suggest a direct relationship between HPRT and the surface of Burkitt’s lymphoma cells, indicating HPRT as a potential target for future immunotherapeutic treatment in Burkitt’s B-cell lymphoma pediatric patients.

Citation Format: Michelle H. Townsend, John Ellis Lattin, Michael D. Anderson, Abigail Felsted, Edwin Velazquez, Evita Weagel, Richard Robison, Kim L. O'Neill. Salvage pathway enzyme HPRT as a molecular marker for Burkitt’s Lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1949. doi:10.1158/1538-7445.AM2017-1949

Evaluation of various glyphosate concentrations on DNA damage in human Raji cells and its impact on cytotoxicity

Glyphosate is a highly used active compound in agriculturally based pesticides. The literature regarding the toxicity of glyphosate to human cells has been highly inconsistent. We studied the resulting DNA damage and cytotoxicity of various glyphosate concentrations on human cells to evaluate DNA damaging potential. Utilizing human Raji cells, DNA damage was quantified using the comet assay, while cytotoxicity was further analyzed using MTT viability assays. Several glyphosate concentrations were assessed, ranging from 15 mM to 0.1 μM. We found that glyphosate treatment is lethal to Raji cells at concentrations above 10 mM, yet has no cytotoxic effects at concentrations at or below 100 μM. Treatment concentrations of 1 mM and 5 mM induce statistically significant DNA damage to Raji cells following 30-60 min of treatment, however, cells show a slow recovery from initial damage and cell viability is unaffected after 2 h. At these same concentrations, cells treated with additional compound did not recover and maintained high levels of DNA damage. While the cytotoxicity of glyphosate appears to be minimal for physiologically relevant concentrations, the compound has a definitive cytotoxic nature in human cells at high concentrations. Our data also suggests a mammalian metabolic pathway for the degradation of glyphosate may be present.

The wide spectrum high biocidal potency of Bioxy formulation when dissolved in water at different concentrations

Traditional surface disinfectants that have long been applied in medicine, animal husbandry, manufacturing and institutions are inconvenient at best and dangerous at worst. Moreover, some of these substances have adverse environmental impacts: for example, quaternary ammonium compounds ("quats") are reproductive toxicants in both fish and mammals. Halogens are corrosive both to metals and living tissues, are highly reactive, can be readily neutralized by metals, and react with organic matter to form toxic, persistent by-products such as dioxins and furans. Aldehydes may be carcinogenic to both human and animals upon repeated exposures, are corrosive, cross-link living tissues and many synthetic materials, and may lose efficacy when pathogens enzymatically adapt to them. Alcohols are flammable and volatile and can be enzymatically degraded by certain bacterial pathogens. Quats are highly irritating to mucous membranes and over time can induce pathogen resistance, especially if they are not alternated with functionally different disinfectants. In contrast, peracetic acid (PAA), a potent oxidizer, liberates hydrogen peroxide (itself a disinfectant), biodegrades to carbon dioxide, water and oxygen, and is at least as efficacious as contact biocides e.g., halogens and aldehydes. Nevertheless, the standard form of liquid PAA is highly corrosive, is neutralized by metals and organic matter, gives off noxious odours and must be stored in vented containers. For the reasons stated above, Bioxy formulations were developed, a series of powder forms of PAA, which are odourless, stable in storage and safe to transport and handle. They generate up to 10% PAA in situ when dissolved in water. A 0.2% aqueous solution of Bioxy (equivalent to 200 ppm PAA) effected a 6.76 log reduction in Methicillin-resistant Staphylococcus aureus (MRSA) within 2 minutes after application. A 5% aqueous solution of Bioxy achieved a 3.93 log reduction in the bovine tuberculosis bacillus Mycobacterium bovis, within 10 minutes after contact. A 1% solution of Bioxy reduced vancomycin-resistant enterococci (VRE) and Pseudomonas aeruginosa by 6.31 and 7.18 logs, respectively, within 3 minutes after application. A 0.5% solution of Bioxy inactivated porcine epidemic diarrhea virus (PEDV) within 15 minutes of contact, and a 5% solution of Bioxy realized a 5.36 log reduction in the spores of Clostridium difficile within 10 minutes of application. In summary, Bioxy is safe and easy to transport and store, poses negligible human, animal and environmental health risks, shows high levels of pathogen control efficacy and does not induce microbial resistance. Further investigations are recommended to explore its use as an industrial biocide.

Abstract 1273: A novel molecular target for lung cancer

The purpose of this study is to provide further evidence that Thymidine Kinase I (TK1) is selectively expressed on the surface of lung cancer cells, and therefore could be utilized as a potential molecular target. TK1 is an enzyme in the pyrimidine salvage pathway whose expression is closely correlated with cell proliferation and cell turnover. It has previously been shown that upregulation of TK1 is an early event in the development of most cancers. Additionally TK1 serum levels in cancer patients correlate with tumor progression and cancer aggressiveness. Moreover TK1 levels in the original tumors have also been shown to correlate directly with tumor recurrence thus making TK1 a useful prognostic marker in clinical oncology. Recent studies in our lab have provided evidence that TK1 is localized on the plasma membrane in lung cancer cells. Using scanning electron microscopy (SEM), flow cytometry, confocal microscopy and tissue staining, we confirmed the presence of TK1 on the cell surface of H460 cells. Using normal lymphocytes as a comparative control we found TK1 expression on lung cancer cells to be significantly increased compared to control cells. For this investigation, we used three custom designed monoclonal antibodies against human TK1 conjugated with FITC, namely CB1, A72 and A74. Using flow cytometry we confirmed the presence of TK1 on the cell surface, our data shows that H460 cells stained positive for TK1 (12% for A72, 19% for A74, and 29% for CB1). Furthermore, confocal microscopy indicated a positive fluorescent signal for A72, A74 and CB1, suggesting the presence of TK1 on the plasma membrane. SEM images of lung cancer cells and normal lymphocytes stained with TK1 antibodies and gold labeling reported a positive gold signal on H460 cells with relatively no signal from human lymphocytes. Immunohistochemistry staining of carcinoma tissue array panels compared with normal tissue array panels indicated a statistical significant difference of expression levels of TK1 between normal lung tissue and lung carcinoma (P value <0.05). Positive staining was considered if more than 5% of the cells were stained. There was negligible staining in normal lung tissue. Using these techniques we confirmed that TK1 is selectively expressed on the surface of H460 cells and not on normal cells. These results suggest that TK1 could be used as a possible molecular target in lung cancer therapy. Further studies are currently ongoing to monitor TK1 expression and progression to help to elucidate the mechanisms behind it's over expression in cancer cells and to track its progression and movement from the cytosol to the cell surface.

Citation Format: Edwin J. Velazquez, Evita G. Weagel, Wei Meng, Michelle H. Townsend, Alex Cummonck, Craig Chandler, Michael R. Downey, Richard Robison, Kim L. O’Neill. A novel molecular target for lung cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1273.

Susceptibility of HPV16 and 18 to high level disinfectants indicated for semi-critical ultrasound probes

Ultrasound probes used in endocavitary procedures have been shown to be contaminated with high‐risk HPV after routine use and HPV is also known to be resistant to some high level disinfectants (HLDs). This study compared efficacy of two leading ultrasound probe HLD methods; liquid ortho‐phthalaldehyde (Cidex® OPA) and an automated device using sonicated hydrogen peroxide (trophon® EPR) against HPV16 and HPV18 in a hard‐surface carrier test. Native HPV16 and HPV18 virions were generated in organotypic epithelial raft cultures. Viral lysates were dried onto carriers with a 5% (v/v) protein soil. Efficacy tests were performed against the automated device at 35% and 31.5% H₂O₂ and 0.55% OPA in quadruplicate with matched input, neutralization, and cytotoxicity controls. Hypochlorite was included as a positive control. Infectivity was determined by the abundance (qRT‐PCR) of the spliced E1^E4 transcript in infected recipient cells. The automated HLD device showed excellent efficacy against HPV16 and HPV18 (>5 log₁₀ reductions in infectivity) whereas OPA showed minimal efficacy (<0.6 log₁₀ reductions). While HPV is highly resistant to OPA, sonicated hydrogen peroxide offers an effective disinfection solution for ultrasound probes. Disinfection methods that are effective against HPV should be adopted where possible. J. Med. Virol. 88:1076–1080, 2016. © 2015 The Authors. Journal of Medical Virology Published by Wiley Periodicals, Inc.

Discriminant ability of the Eating Assessment Tool-10 to detect aspiration in individuals with amyotrophic lateral sclerosis

BACKGROUND

Oropharyngeal dysphagia is prevalent in individuals with amyotrophic lateral sclerosis (ALS) leading to malnutrition, aspiration pneumonia, and death. These factors necessitate early detection of at-risk patients to prolong maintenance of safe oral intake and pulmonary function. This study aimed to evaluate the discriminant ability of the Eating Assessment Tool (EAT-10) to identify ALS patients with unsafe airway protection during swallowing.

METHODS

Seventy ALS patients completed the EAT-10 survey and underwent a standardized videofluoroscopic evaluation of swallowing. Two blinded raters determined airway safety using the Penetration Aspiration Scale (PAS). A between groups anova (safe vs penetrators vs aspirators) was conducted and sensitivity, specificity, area under the curve (AUC), and likelihood ratios calculated.

KEY RESULTS

Mean EAT-10 scores for safe swallowers, penetrators, and aspirators (SEM) were: 4.28 (0.79) vs 7.10 (1.79) vs 20.50 (3.19), respectively, with significant differences noted for aspirators vs safe swallowers and aspirators vs penetrators (p < 0.001). The EAT-10 demonstrated good discriminant ability to accurately identify ALS penetrator/aspirators (PAS ≥3) with a cut off score of 3 (AUC: 0.77, sensitivity: 88%, specificity: 57%). The EAT-10 demonstrated excellent accuracy at identifying aspirators (PAS ≥6) utilizing a cut off score of 8 (AUC: 0.88, sensitivity: 86%, specificity: 72%, likelihood ratio: 3.1, negative predictive value: 95.5%).

CONCLUSIONS & INFERENCES

The EAT-10 differentiated safe vs unsafe swallowing in ALS patients. This patient self-report scale could represent a quick and meaningful aide to dysphagia screening in busy ALS clinics for the identification and referral of dysphagic patients for further instrumental evaluation.

Letharia vulpina, a vulpinic acid containing lichen, targets cell membrane and cell division processes in methicillin-resistant Staphylococcus aureus

CONTEXT

Antibiotic resistance in humans is a major concern. Drugs that target traditional sites and pathways are becoming obsolete; thus, compounds affecting novel targets are needed. Screening lichen metabolites for antimicrobials has yielded promising antimicrobial compounds, yet their mode of action is poorly understood. Letharia vulpina (L.) Hue (Parmeliaceae) has traditionally been used to poison predators, and treat stomach disorders; more recently L. vulpina extracts have demonstrated promising antimicrobial properties.

OBJECTIVE

This study investigates the mode of action of L. vulpina acetone extract against a methicillin-resistant Staphylococcus aureus (MRSA).

MATERIAL AND METHODS

We treated MRSA with L. vulpina extracts at 1×, 5×, and 10 × MIC values (MIC = 31.25 µg/ml) for 24 h and optical density (OD660) was measured over time to determine bacteriolytic activity; counted colony forming units (CFUs) to determine time kill dynamics; the propidium iodide (PI) assay and transmission electron microscopy were used to assess membrane-damage potential, and thin-layer chromatography was used to identify secondary compounds.

RESULTS

Bacteriolytic assays showed that L. vulpina extracts, containing only vulpinic acid, do not cause cell lysis, even at 10 × MIC values but there was 92% reduction in bacterial CFUs when treated with increased concentrations of lichen extracts over 24 h at 4 h intervals. Our data indicate that the L. vulpina extract compromises membrane integrity of the MRSA isolate and disrupts cell division processes.

DISCUSSION AND CONCLUSION

Based on this study, detailed examination of acetone extracts of L. vulpina as well as pure extracts of vulpinic acid as potential antibacterial compounds merit further study.

Abstract 3220: Lichen derived polyphenols as potential anticancer drugs

Polyphenols such as resveratrol, curcumin, (-)-epigallocatechin 3-gallate (EGCG) etc. have been shown to have anticancer properties. The anticancer activities of polyphenols include, but are not limited to, anti-oxidative effects, pro-apoptosis, DNA damage, anti-angiogenic effects, and immunostimulation. Lichens, symbiotic systems involving a fungus and an alga and/or cyanobacterium, are a rich source of polyphenols. Based on our previous research we have demonstrated that crude extracts of different lichen species affect cell proliferation, cell cycle dynamics, and cause apoptosis in Burkitt's lymphoma (Raji cells). This research examines the effects of a lichen-derived polyphenol compound, usnic acid, on human colon adenocarcinoma (HT-29) cells. We treated HT-29 cells with various concentrations (10, 30 and 50 µg/ml) of usnic acid for 24 hours. Although the viability was not affected by the treatment, there was a significant decrease in cell proliferation in dose-dependent manner. We also observed that after treatment, the morphology of treated cells was completely different from that of untreated control cells. Using transmission electron microscopy (TEM), we studied the morphological differences between control and treated HT-29 cells. The TEM micrographs clearly show that usnic acid damaged the mitochondria, reduced the amount of free ribosomes, and also distorted the shape of the nucleus. As the treatment of HT-29 with usnic acid reduced the rate of cell proliferation significantly, we investigated the effects of usnic acid on HT-29 cell cycle dynamics. Our results indicate that with the higher usnic acid concentrations (30 and 50 µg/ml) the cell cycle was stopped at the G0/G1 stage. These results further document the pattern of decreasing proliferation of HT-29 cells treated with usnic acid. With the distortion of the nucleus following exposure to usnic acid, we also investigated the effects of usnic acid on DNA the HT-29 cells. We performed a single cell gel electrophoresis (Comet Assay) to study the DNA damaging effects of various concentrations of usnic acid. Our results showed that there was a dose dependent increase in damage to the HT-29 cells' DNA resulting in 56.7% of the total DNA moving into the comet tail at 50 µg/ml concentration of usnic acid.

These preliminary results suggest that lichen derived polyphenols could be a potential source of anticancer drug therapies. However, additional research is needed to further validate these findings.

Citation Format: Gajendra Shrestha, Michael Xiao, Richard Robison, Larry L. St. Clair, Kim O'Neill. Lichen derived polyphenols as potential anticancer drugs. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3220. doi:10.1158/1538-7445.AM2014-3220

Susceptibility of high-risk human papillomavirus type 16 to clinical disinfectants

OBJECTIVES

Little to nothing is known about human papillomavirus (HPV) susceptibility to disinfection. HPV is estimated to be among the most common sexually transmitted diseases in humans. HPV is also the causative agent of cervical cancers and other anogenital cancers and is responsible for a significant portion of oropharyngeal cancers. While sexual transmission is well documented, vertical and non-sexual transmission may also be important.

METHODS

Using recombinant HPV16 particles (quasivirions) and authentic HPV16 grown in three-dimensional organotypic human epithelial culture, we tested the susceptibility of high-risk HPV to clinical disinfectants. Infectious viral particles were incubated with 11 common clinical disinfectants, appropriate neutralizers were added to inactivate the disinfectant and solutions were filter centrifuged. Changes in the infectivity titres of the disinfectant-treated virus were measured compared with untreated virus.

RESULTS

HPV16 is a highly resistant virus; more so than other non-enveloped viruses previously tested. The HPV16 quasivirions showed similar resistance to native virions, except for being susceptible to isopropanol, the triple phenolic and the lower concentration peracetic acid-silver (PAA-silver)-based disinfectant. Authentic virus and quasivirus were resistant to glutaraldehyde and ortho-phthalaldehyde and susceptible to hypochlorite and the higher concentration PAA-silver-based disinfectant.

CONCLUSIONS

We present the first disinfectant susceptibility data on HPV16 native virions, which show that commonly used clinical disinfectants, including those used as sterilants in medical and dental healthcare facilities, have no effect on HPV16 infectivity. Policy changes concerning disinfectant use are needed. The unusually high resistance of HPV16 to disinfection supports other data suggesting the possibility of fomite or non-sexual transmission of HPV16.

Abstract 2250: Cytototoxicity and mode of action of extract from of two lichens, Tuckermannopsis ciliaria (Ach.) Gyelnik and Xanthoparmelia chlorochroa (Tuck.) Hale against Burkitt's Lymphoma (Raji) cells and the Human colon cancer (HT-29) cell line

Natural products from various plants, microorganisms, fungi etc. have provided considerable value to the pharmaceutical industry over the past half century. But there still remains a vast potential reservoir of possible useful therapeutics, yet to be identifed. Among them, lichens (symbiotic associations between a fungus and an alga and/or a cyanobacterium), which produce more than a 1000 secondary chemicals. The United States is home to a diverse assemblage of lichen species. Lichens play many biological roles; however, their full potential as a source of anticancer drugs has been largely unexplored. To examine the possible anticancer role of several lichen species, we assessed the cytotoxic activity of 17 species collected from various parts of the US. Secondary compounds of these lichens were extracted with acetone and screened against Burkitt's Lymphoma cells (Raji) and the human colon cancer cell line (HT-29). Based on the cytotoxcity of these lichen extracts we selected two species Tuckermannopsis ciliaris and Xanthoparmelia chlorochroa for further testing. IC50 values for these two species showed particular promise - 28.8 and 28.6 μg/ml for Raji cells and 60 and 40 μg/ml for HT-29 cells respectively. The viability and cell growth of both cell lines was significantly reduced by the extracts from these two lichens but these extracts did not affect the viability and growth of normal lymphocytes. We performed morphological detection of apoptosis using Acridine orange and Propidium Iodide. Extracts from both lichens were found to induce apoptosis in both cancer cell lines when treated with the concentrations equivalent to the IC50. Cell proliferation of Raji and HT-29 cells, as measured by 3H-thymidine incorporation, was significantly reduced in treated cells (P &lt;0.05) over 24 hours as compared with controls. To further investigate apoptosis we measured DNA fragmentation using gel electrophoresis. Within 24 hours of treatment, there was partial DNA degradation. Using flow cytometry, it was discovered that extracts from both lichens arrested cell-cycle progression in S phase. Using RT-PCR, it was found that the p53 gene was up-regulated in the treated cells during G1 phase while the DNA repair enzyme Thymidine kinase 1 (TK1) was down regulated.

In conclusion, extracts from T. ciliaris and X. chlorochroa were both cytotoxic and induced apoptosis in cancer cells but not in normal cells. Hence extracts from these two lichens could hold potential as a non-toxic anticancer therapy. However, more research is required to further elucidate the molecular mechanisms behind these preliminary findings.

Citation Format: Gajendra Shrestha, Atif M. El-Naggar, Sean C. Derenthal, Michael R. Boswell, Evita Weagel, Larry L. St. Clair, Richard Robison, Kim L. O'Neill. Cytototoxicity and mode of action of extract from of two lichens, Tuckermannopsis ciliaria (Ach.) Gyelnik and Xanthoparmelia chlorochroa (Tuck.) Hale against Burkitt's Lymphoma (Raji) cells and the Human colon cancer (HT-29) cell line. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2250. doi:10.1158/1538-7445.AM2013-2250

A Comparison of Antioxidant Properties in Organic and Conventional Blueberries

<em>Vacciniumcyanococcus</em>, most commonly known as blueberry, is a fruit native to North America that is known for its unique taste and high antioxidant content. The skin, seed and juice of both organically and conventionally grown blueberry extract were analyzed for antioxidant content using both the Hydrophilic and Lipophilic Oxygen Radical Absorbance Capacity (ORAC) assays. Results from the Hydrophilic ORAC test showed that conventionally grown blueberries had a higher antioxidant capacity across all samples, while the Lipophilic ORAC assay showed that the antioxidant concentration of organically cultivated blueberry juice was highest, but conventionally grown blueberry seed and skin extract showed higher antioxidant content. The vitamin C content of both conventional and organic blueberries was analyzed using High Performance Liquid Chromatography (HPLC), where the organic blueberries showed a higher vitamin C concentration. In general, both organic and conventional blueberries are rich in antioxidants, and therefore, possess potential health benefits that require further study.

Abstract 5437: Blueberries: Conventional cancer prevention

Coronary heart disease and cancer, besides remaining the two leading causes of death in the United States, share another common trait: they can both be attributed to lifestyle choices that increase their risk. Epidemiological studies suggest that the consumption of both an antioxidant and phytochemical-rich diet contribute towards the reduction of heart disease and several cancer types. There has been a substantial amount of interest in Vaccinium corymbosum, also known as blueberries, due to their high antioxidant levels which have been show to help prevent cancer of the colon, breast, and prostate. Blueberries exhibit a high content of both phytochemicals such as flavonoids and tannins; and antioxidants such as phenolic acid and resveratrol. Antioxidants provide protection against oxidative stress, a condition that has been suggested to contribute to a variety of diseases, including atherosclerosis, Parkinson's disease, and cancer. The purpose of this study was to explore the health benefits of organic vs. conventional blueberry consumption by comparing the antioxidant content of their individual components, including pulp, skin, seed, and juice using both the Hydrophilic Oxygen Radical Absorbance Capacity (H-ORAC) and the Lipophilic Oxygen Radical Absorbance Capacity (L-ORAC) assay. High-Performance Liquid Chromatography (HPLC) was also used to identify and quantify the amount of Vitamin C in both the organic and conventional blueberries. Blueberry samples were obtained from local distributors and the assays were replicated with five different lots of blueberries. Results indicated that conventional blueberries (33,388 TE/100g pulp, seed, skin and 607,700 TE/L juice) have higher antioxidant levels than organic blueberries (25,800 TE/100g pulp, seed, skin and 415,608 TE/L juice) across all samples. Conversely, HPLC determined a slightly higher Vitamin C content in the organically grown blueberries (592.879 μg/g) compared to conventional blueberries (386.947 μg/g). These results suggest that conventional blueberries may have a higher health benefit potential in preventing cancer and many other degenerative diseases that plague the world.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5437. doi:1538-7445.AM2012-5437

Abstract 4614: The organic panic

In today's market place organic foods have become a very popular topic of discussion. Some studies have compared the different benefits of organic foods vs. conventional foods in disease prevention, including cancer. Although differences have been examined, no broad or concrete conclusions have been reached. Studies have shown that consumption of antioxidants can decrease the risk of oxidative damage, degenerative conditions, and cancer. In this study, antioxidant levels between organic blueberries and conventional blueberries were analyzed and compared in their skin, seed, and juice using the Oxygen Radical Absorbance Capacity assay (ORAC). Data indicate that, in each sample category, conventional samples showed higher antioxidant activities overall when compared to organic samples. 15 organic samples and 15 conventional samples were taken for measurement of antioxidant activity. All values are reported as Trolox Equivalents per 100 grams sample (TE/100g). Conventional blueberry skin revealed highest overall antioxidant activity (7258 TE/100g, s=1024), while organic blueberry seed revealed the lowest (494 TE/100g, s=160). Conventional skin (7258 TE/100g, s=1024) revealed higher values than organic skin (3891 TE/100g, s=288). Conventional seed (1308 TE/100g, s=597) revealed higher values than organic seed (494 TE/100g, s=160). Conventional juice (5077 TE/100g) revealed higher values than organic juice (2205 TE/100g, s=276). Student's t-test analysis revealed statistically significant differences between conventional and organic samples in all three groups (organic vs. conventional skin, p=1.3×10-5, organic vs. conventional seed, p=0.008; organic vs. conventional juice, p=0.022). Data from this study suggest that consumption of organic fruits may not provide higher antioxidant protection when compared to consumption of conventional samples; consumption on conventional blueberries may prove to be most beneficial. Further studies on other fruit samples may provide additional insight on the antioxidant benefits of organic and conventional fruits and vegetables.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4614. doi:10.1158/1538-7445.AM2011-4614

Abstract 803: Microsphere engulfment by macrophages when exposed to breast and colon tumor microenvironments

The microenvironment of most tumors is filled with a large population of macrophages. In breast cancer, studies have found that macrophages can account for &gt;50% of the tumor mass. Their presence within the tumor microenvironment, in some cases, has been proven to increase metastasis, angiogenesis, and immunosuppression. However, colorectal cancer has been seen in some cases to exhibit decreased tumor growth and proliferation when a larger number of macrophages are associated with the tumor. Previous studies have suggested that cytokines and chemokines released by the tumor cells in the tumor microenvironment influence the polarization of the macrophages present. The M1 phenotype will often lead to aggressive destruction of the tumor, while an M2 phenotype will in fact aid tumor survival. M2 macrophages have been suggested to have a reduced phagocytic function. In this study, we investigated overall phagocytosis of microspheres by U-937 derived macrophages when exposed to nutrient-depleted media from both breast and colon cancer cell lines as well as when exposed to nutrient-depleted media containing cancer cells themselves. U-937's were stained with Efluor 670 dye for identification and then stimulated using phorbol 12-myristate 13-acetate (PMA). Macrophages were then incubated for various time periods with cancer cells seeded in 6-well plates. Engulfment was measured by adding fluorescent latex microspheres to samples and assayed using a flow cytometer. Overall engulfment was measured as the percent of macrophages in a sample that engulfed microspheres while aggressiveness was measured as the amount of beads that macrophages were seen to phagocytose. Controls indicate that 5-10% of cancer cells non-specifically bind microspheres and that approximately 20% of unstimulated U937's engulf beads, whereas positive controls indicate that 80% of PMA stimulated U937's engulf microspheres. Further results show that incubation in spent media from both breast and colon cell lines did not significantly alter overall phagocytosis or aggressiveness. However, when incubated with either colon or breast cancer cell lines in spent media, there is as high as a 30% reduction in overall engulfment, indicating a shift toward an M2 phenotype. When macrophages are co-cultured with non-cancerous lymphocytes, the overall engulfment stays consistent with positive controls. Also, highly aggressive macrophages engulfed significantly less aggressively when exposed to tumor microenvironments as compared to positive controls. This study suggests that the microenvironment influences the polarization of macrophages via cell to cell contact and that both overall engulfment and aggressiveness of macrophages are affected. It also suggests that the microenvironments of both breast and colon cancer are equally able to polarize macrophages toward M2.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 803. doi:10.1158/1538-7445.AM2011-803

Genome-wide linkage in Utah autism pedigrees

Genetic studies of autism over the past decade suggest a complex landscape of multiple genes. In the face of this heterogeneity, studies that include large extended pedigrees may offer valuable insights, as the relatively few susceptibility genes within single large families may be more easily discerned. This genome-wide screen of 70 families includes 20 large extended pedigrees of 6-9 generations, 6 moderate-sized families of 4-5 generations and 44 smaller families of 2-3 generations. The Center for Inherited Disease Research (CIDR) provided genotyping using the Illumina Linkage Panel 12, a 6K single-nucleotide polymorphism (SNP) platform. Results from 192 subjects with an autism spectrum disorder (ASD) and 461 of their relatives revealed genome-wide significance on chromosome 15q, with three possibly distinct peaks: 15q13.1-q14 (heterogeneity LOD (HLOD)=4.09 at 29 459 872 bp); 15q14-q21.1 (HLOD=3.59 at 36 837 208 bp); and 15q21.1-q22.2 (HLOD=5.31 at 55 629 733 bp). Two of these peaks replicate earlier findings. There were additional suggestive results on chromosomes 2p25.3-p24.1 (HLOD=1.87), 7q31.31-q32.3 (HLOD=1.97) and 13q12.11-q12.3 (HLOD=1.93). Affected subjects in families supporting the linkage peaks found in this study did not reveal strong evidence for distinct phenotypic subgroups.

Abstract 3820: Inhibition of M1 macrophages may aid the conversion process to M2, which may aid tumor survival and growth

Macrophages perform a variety of functions, from phagocytosis to the repair and remodeling of damaged tissues. Two phenotypes have been proposed: M1 and M2. The M1 macrophage performs phagocytosis of tumor cells and releases pro-inflammatory cytokines. The M2 macrophage acts as a support cell by promoting the healing of damaged cells by angiogenesis and tissue remodeling. The transition from M1 to M2 may be facilitated by tumor environments. To further study the relationship between cancer and macrophages we developed a live-cell migration assay, which measures cancer's ability to recruit macrophages. We hypothesize that cancer cell lines have varied abilities to recruit macrophages and convert them into M2, and that this ability corresponds to the aggressiveness of the cell line. Macrophages were derived from the human mononuclear phagocyte cell line U937, after addition of phorbol 12-myristate 13-acetate (PMA). These U937 cells were incubated with three adenocarcinomas of varying aggressivity. The adenocarcinomas were MDA-MB-435, MDA-MB-231, and MCF7. The U937 cells were separated from the three cell lines by 3.0 µm trans-permeable polycarbonate membranes (Corning Inc.) which allowed the U937 cells to migrate to the cell lines. After 1 hour non-migratory U937 cells were isolated and counted by means of a hemocytometer. The control without cancer caused 73.86% of U937 cells to remain, MDA-MB-435 69.28% (N=24, P=0.29), MCF7 61.09% (N=24, P&lt;0.01), and MDA-MB-231 55.83% (N=24, P&lt;0.01). This data was then compared with expression levels of macrophage Migration Inhibition Factor (MIF) analyzed from Real Time PCR data. These samples consisted of monocytes, from human blood, which were co-incubated with the cell lines for 48 hours. The cells were separated by 0.4 µm trans-permeable polycarbonate membranes (Corning Inc.) to prevent cells from coming into contact and allowing signal exchange. The RT-PCR data correlated with the migration data. The amount of MIF increased 7.56 fold, (N=9) in MDA-MB-435 when compared to controls, 3.13 fold for MCF7 (N=9), and 1.33 fold for MDA- MB-231 (N=9). This data suggests that the more aggressive the cancer the more MIF emitted and the greater the potential to inhibit macrophages. Previous studies have shown Interleukin-10, (IL-10), IL-6, IL-4, and prostaglandin F2 (PGF2) to be released from tumors and inhibit the cytotoxic activity of macrophages. This exposure to IL-10 has been suggested to convert M1 macrophages to a M2 phenotype. The migration inhibition observed from this study might be the initial step in the conversion process from M1 to M2.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3820.

Volatile antimicrobials from Muscodor crispans, a novel endophytic fungus

Muscodor crispans is a recently described novel endophytic fungus of Ananas ananassoides (wild pineapple) growing in the Bolivian Amazon Basin. The fungus produces a mixture of volatile organic compounds (VOCs); some of the major components of this mixture, as determined by GC/MS, are propanoic acid, 2-methyl-, methyl ester; propanoic acid, 2-methyl-; 1-butanol, 3-methyl-;1-butanol, 3-methyl-, acetate; propanoic acid, 2-methyl-, 2-methylbutyl ester; and ethanol. The fungus does not, however, produce naphthalene or azulene derivatives as has been observed with many other members of the genus Muscodor. The mixture of VOCs produced by M. crispans cultures possesses antibiotic properties, as does an artificial mixture of a majority of the components. The VOCs of the fungus are effective against a wide range of plant pathogens, including the fungi Pythium ultimum, Phytophthora cinnamomi, Sclerotinia sclerotiorum and Mycosphaerella fijiensis (the black sigatoka pathogen of bananas), and the serious bacterial pathogen of citrus, Xanthomonas axonopodis pv. citri. In addition, the VOCs of M. crispans killed several human pathogens, including Yersinia pestis, Mycobacterium tuberculosis and Staphylococcus aureus. Artificial mixtures of the fungal VOCs were both inhibitory and lethal to a number of human and plant pathogens, including three drug-resistant strains of Mycobacterium tuberculosis. The gaseous products of Muscodor crispans potentially could prove to be beneficial in the fields of medicine, agriculture, and industry.

A quadruplex real-time PCR assay for the detection of Yersinia pestis and its plasmids

Yersinia pestis, the aetiological agent of the plague, causes sporadic disease in endemic areas of the world and is classified as a National Institute of Allergy and Infectious Diseases Category A Priority Pathogen because of its potential to be used as a bioweapon. Health departments, hospitals and government agencies need the ability to rapidly identify and characterize cultured isolates of this bacterium. Assays have been developed to perform this function; however, they are limited in their ability to distinguish Y. pestis from Yersinia pseudotuberculosis. This report describes the creation of a real-time PCR assay using Taqman probes that exclusively identifies Y. pestis using a unique target sequence of the yihN gene on the chromosome. As with other Y. pestis PCR assays, three major genes located on each of the three virulence plasmids were included: lcrV on pCD1, caf1 on pMT1 and pla on pPCP1. The quadruplex assay was validated on a collection of 192 Y. pestis isolates and 52 near-neighbour isolates. It was discovered that only 72 % of natural plague isolates from the states of New Mexico and Utah harboured all three virulence plasmids. This quadruplex assay proved to be 100 % successful in differentiating Y. pestis from all near neighbours tested and was able to reveal which of the three virulence plasmids a particular isolate possessed.