The safety and potential efficacy of exosomes overexpressing CD24 (EXO-CD24) in mild-moderate COVID-19 related ARDS

INTRODUCTION

EXO-CD24 are exosomes genetically manipulated to over-express Cluster of Differentiation (CD) 24. It consists of two breakthrough technologies: CD24, the drug, as a novel immunomodulator that is smarter than steroids without any side effects, and exosomes as the ideal natural drug carrier.

METHODS

A randomized, single blind, dose-finding phase IIb trial in hospitalized patients with mild to moderate Coronavirus disease 2019 (COVID-19) related Acute Respiratory Distress Syndrome (ARDS) was carried out in two medical centers in Athens. Patients received either 109 or 1010 exosome particles of EXO-CD24, daily, for five consecutive days and monitored for 28 days. Efficacy was assessed at day 7 among 91 patients who underwent randomization. The outcome was also compared in a post-hoc analysis with an income control group (n = 202) that fit the inclusion and exclusion criteria.

RESULTS

The mean age was 49.4 (± 13.2) years and 74.4% were male. By day 7, 83.7% showed improved respiratory signs and 64% had better oxygen saturation (SpO2) (p < 0.05). There were significant reductions in all inflammatory markers, most notably in C-reactive protein (CRP), lactate dehydrogenase (LDH), ferritin, fibrinogen and an array of cytokines. Conversely, levels of the anti-inflammatory cytokine Interleukin-10 (IL-10) were increased (p < 0.05). Of all the documented adverse events, none were considered treatment related. No drug-drug interactions were noted. Two patients succumbed to COVID-19. Post-hoc analysis revealed that EXO-CD24 patients exhibited greater improvements in clinical and laboratory outcomes compared to an observational income control group.

CONCLUSIONS

EXO-CD24 presents a promising therapeutic approach for hyper-inflammatory state and in particular ARDS. Its unique combination of exosomes, as a drug carrier, and CD24, as an immunomodulator, coupled with inhalation administration, warrants further investigation in a larger, international, randomized, quadri-blind trial against a placebo.

Inhaled CD24-Enriched Exosomes (EXO-CD24) as a Novel Immune Modulator in Respiratory Disease

Acute Respiratory Distress Syndrome (ARDS) is a major health concern with urgent unmet need for treatment options. There are three million new ARDS cases annually, and the disease's mortality rate is high (35-46%). Cluster of differentiation 24 (CD24), a long-known protein with multifaceted functions, is a small, heavily glycosylated, membrane-anchored protein which functions as an immune checkpoint control. CD24 allows for immune discrimination between Damage-Associated Molecular Patterns and Pathogen-Associated Molecular Patterns derived from pathogens. Exosomes are intraluminal vesicles which play an important role in intercellular communication. Exosomes offer the advantage of targeted delivery, which improves safety and efficacy. The safety and efficacy of EXO-CD24 is promising, as was shown in >180 ARDS patients in phase 1b/2a, phase 2b, and compassionate use. CD24 binds Damage-associated molecular patterns (DAMPs) and inhibits the activation of the NF-ĸB pathway, a pivotal mediator of inflammatory responses. In contrast to anti-inflammatory therapies that are cytokine-specific or steroids that shut down the entire immune system, EXO-CD24 acts upstream, reverting the immune system back to normal activity. Herein, the safety and efficacy of mEXO-CD24 is shown in murine models of several pulmonary diseases (sepsis, allergic asthma, Chronic Obstructive Pulmonary Disease(COPD), fibrosis). EXO CD24 can suppress the hyperinflammatory response in the lungs in several pulmonary diseases with a significant unmet need for treatment options.

CD24 in Head and Neck Malignancies-An Uprising Biomarker?

INTRODUCTION

CD24 is often overexpressed in human tumors as a regulator of cell migration, invasion and proliferation. It has been associated with poor prognosis and chemoresistance in laryngeal cancer. In oral cavity tumors, it was correlated with better overall survival. In this study, we aimed to evaluate the role of CD24 in peripheral blood leukocytes (PBLs) as a potential marker for head and neck malignancies.

MATERIALS AND METHODS

CD24/CD11b expression in peripheral blood leukocytes (PBLs) of head and neck cancer patients and matched healthy controls was analyzed via flow cytometry. Tumors and healthy tissues were immune-stained for CD24 expression and the intensity of stain was ranked. Clinical data including tumor site, size, locoregional or metastatic spread, histopathological characteristics and recurrence events were analyzed.

RESULTS

CD24 expression in PBLs was significantly higher in a cohort of 101 head and neck cancer patients compared with 101 matched healthy controls (26.9 ± 12.9 vs. 22.4 ± 13.8; p = 0.02). No significant differences in CD24 levels in PBLs were found between different head and neck subsites involved with malignancy. Higher CD24 levels did not correlate with any adverse feature, i.e., perineural invasion or lymphovascular invasion, advanced T stage or regional spread. Immunohistochemistry analysis demonstrated that CD24 was highly expressed in tumor tissue in comparison to healthy surrounding tissue.

CONCLUSIONS

CD24 is a possible uprising marker for tumor identification, overexpressed in PBLs and is intensely stained in tumor tissue and pre-malignant lesions. Tumor-PBLs should be further studied.

Inhaled Exosomes Genetically Manipulated to Overexpress CD24 (EXO-CD24) as a Compassionate Use in Severe ARDS Patients

RATIONALE

Acute respiratory distress syndrome (ARDS) is a major global health concern with a significant unmet need. EXO-CD24 is delivered via inhalation-reduced cytokines and chemokine secretion and lung injury in ARDS and improved survival in mice models of ARDS, influenza, and sepsis.

OBJECTIVES

This clinical paper aims to evaluate the potential of EXO-CD24, a novel immunomodulatory treatment, in the compassionate care of critically ill, intubated patients with post-infection-induced acute respiratory distress syndrome (ARDS).

METHODS

Eleven critically ill patients diagnosed with post-infection ARDS (10 with COVID-19 and one with an adenovirus-associated infection) were administered EXO-CD24 in four medical centers across Israel. The patients had multiple co-morbidities, including cancer, hypertension, diabetes, and ischemic heart disease, and met the criteria for severe ARDS according to the Berlin classification. EXO-CD24 was administered via inhalation, and adverse events related to its use were carefully monitored.

MEASUREMENTS AND MAIN RESULTS

The administration of EXO-CD24 did not result in any recorded adverse events. The median hospitalization duration was 11.5 days, and the overall mortality rate was 36%. Notably, patients treated at the Tel Aviv Medical Center (TASMC) showed a lower mortality rate of 12.5%. The WBC and CRP levels decreased in comparison to baseline levels at hospitalization, and rapid responses occurred even in patients with kidney transplants who were off the ventilator within a few days and discharged shortly thereafter. The production of cytokines and chemokines was significantly suppressed in all patients, including those who died. Among the patients at TASMC, four had kidney transplants and were on immunosuppressive drugs, and all of them fully recovered and were discharged from the hospital.

CONCLUSIONS

EXO-CD24 holds promise as a potential therapeutic agent for all stages of ARDS, even in severe intubated cases. Importantly, EXO-CD24 demonstrated a favorable safety profile without any apparent side effects with promising efficacy. Furthermore, the potential of EXO-CD24 as a platform for addressing hyper-inflammatory states warrants exploration. Further research and larger-scale clinical trials are warranted to validate these preliminary findings.

Renal Tubular CD24 Upregulation Aggravates Folic Acid Induced Acute Kidney Injury: A Possible Role for T Regulatory Cells Inhibition in Mice

Acute kidney injury (AKI) is characterized by cell death and inflammation. CD24 is a protein induced during tissue damage and is not expressed in mature renal tissue. We explored the role of CD24 in the pathogenesis of folic acid-induced AKI (FA-AKI) in mice. A single Intraperitoneal (IP) injection of folic acid induced AKI in WT and CD24^-/- mice. Renal function tests, histological analysis, immunohistochemistry, Western blot analysis, and ELISA were performed to assess the severity of renal damage and the intensity of the inflammatory response. FA-AKI induced CD24 in the distal tubular epithelial cells. Compared to WT mice, FA-AKI CD24^-/- mice exhibited an attenuated reduction in renal function and histological injury, lower serum IL-10 and interferon γ, and decreased expression of renal TNFα. In contrast, renal and systemic IL-33 upregulation were augmented. CD24^-/- FA-AKI animals exhibited increased splenic margination and renal infiltration of regulatory T cells (Tregs). At day 7, FA-AKI CD24^-/- mice exhibited increased expression of tubular pro-apoptotic and decreased anti-apoptotic proteins compared to WT animals. Anti-CD24 antibody administration to FA-AKI mice attenuated the decrease in renal function as well as the histological injury. Renal biopsies from patients with ATN stained strongly for CD24 in the distal tubules. In conclusion, during AKI, upregulation of CD24 promotes renal inflammation through inhibition of Treg infiltration and diversion of cell death towards necrosis rather than apoptosis. Neutralization of CD24 may prove a target for future therapies in AKI.

Data From a One-Stop-Shop Comprehensive Cancer Screening Center

PURPOSE

Cancer is the second leading cause of death globally. However, by implementing evidence-based prevention strategies, 30%-50% of cancers can be detected early with improved outcomes. At the integrated cancer prevention center (ICPC), we aimed to increase early detection by screening for multiple cancers during one visit.

METHODS

Self-referred asymptomatic individuals, age 20-80 years, were included prospectively. Clinical, laboratory, and epidemiological data were obtained by multiple specialists, and further testing was obtained based on symptoms, family history, individual risk factors, and abnormalities identified during the visit. Follow-up recommendations and diagnoses were given as appropriate.

RESULTS

Between January 1, 2006, and December 31, 2019, 8,618 men and 8,486 women, average age 47.11 ± 11.71 years, were screened. Of 259 cancers detected through the ICPC, 49 (19.8%) were stage 0, 113 (45.6%) stage I, 30 (12.1%) stage II, 25 (10.1%) stage III, and 31(12.5%) stage IV. Seventeen cancers were missed, six of which were within the scope of the ICPC. Compared with the Israeli registry, at the ICPC, less cancers were diagnosed at a metastatic stage for breast (none v 3.7%), lung (6.7% v 11.4%), colon (20.0% v 46.2%), prostate (5.6% v 10.5%), and cervical/uterine (none v 8.5%) cancers. When compared with the average stage of detection in the United States, detection was earlier for breast, lung, prostate, and female reproductive cancers. Patient satisfaction rate was 8.35 ± 1.85 (scale 1-10).

CONCLUSION

We present a proof of concept study for a one-stop-shop approach to cancer screening in a multidisciplinary outpatient clinic. We successfully detected cancers at an early stage, which has the potential to reduce morbidity and mortality as well as offer substantial cost savings.

1153. Safety and Potential Efficacy of Exosomes Overexpressing CD24 (EXO-CD24) for the Prevention of Clinical Deterioration in Patients with Moderate or Severe COVID-19: A Phase II, Randomized, Single-blinded Study

Background

EXO-CD24 is a novel inhaled drug of exosomes displaying CD24, a protein with anti-inflammatory properties. We evaluated the safety and potential efficacy of EXO-CD24, in a phase II, randomized, single-blinded clinical trial of EXO-CD24 in hospitalized patients with moderate or severe COVID-19, following the preliminary safety and efficacy results of a phase 1 study (ClinicalTrials.gov: NCT04747574).

Methods

Two tertiary care hospitals in Athens, Greece participated. Patients received either 10⁹ or 10¹⁰ exosome particles per dose, once per day for 5 days and were followed for 28 days. Safety and efficacy measures (including respiratory rate < 23 b/min and pulse oximetry SpO₂≥ 94% on room air, oxygen need and levels of inflammatory biomarkers i.e. CRP, LDH, ferritin, fibrinogen and d-dimers) were compared between groups at days 3, 5 and 7. A separate analysis was conducted comparing the clinical course of treated patients with that of a control cohort (n=70 patients) matched by propensity scoring out of a similar period hospitalized cohort (n=202) that did not participate in the study.

Results

Between June 9th and August 3rd 2021, 91 patients underwent randomization: 45 in group A and 46 in group B (10⁹vs. 10¹⁰ exosome particles per dose). Mean age was 49.4 (± 13.2) years and 74.4% were male. Mean time from symptom onset to randomization was 8 days. Improvement in respiratory rate and pulse oximetry was noted in 72 out of 86 (83.7%) and 55 out of 86 (64%) analyzed patients. Day 7 inflammatory indices levels dropped at least 50% from baseline admission values in 72 out of 86 (82.8%) analyzed patients (p< 0.001). No treatment-related adverse events were reported. Comparison with the propensity score matched group showed statistically significant differences in the same parameters (p≤ 0.01 for all comparisons).

Conclusion

Our results suggest safety and potential efficacy of EXO-CD24 on clinical and laboratory parameters of moderate or severe COVID-19, that deserve further investigation in a phase 3 study. (Funded by Athens Medical Society. ClinicalTrials.gov: NCT04902183, EU Clinical Trials Register EudraCT Number 2021-002184-22).

Disclosures

All Authors: No reported disclosures.

Digital coping of parents in conflict-affected communities: a path to maintain health and well-being

Background

Mobile apps such as WhatsApp have become significant resources for information and social support in times of crisis. Little is known about the role WhatsApp groups play in the context of living in conflict-affected regions. Living in such areas is associated with myriad mental health impacts, and recent studies have identified parents of young children as highly vulnerable in this regard. The study’s aim was to examine parents’ digital coping with political violence in southern Israel.

Methods

In-depth interviews were conducted with 21 parents of young children (<17) residing in communities near the Israel-Gaza border and who are members of local online parents’ groups on WhatsApp. Data were analyzed to answer questions regarding the benefits and disadvantages that parents assign to online groups; and regarding the role of digital communication in maintaining health and well-being.

Results

The findings reveal that online groups are often discussed as a shared and ubiquitous coping resource that supports mental health and well-being. Parents report they use the group to share ways to deal with the situation effectively and exchange social support, and as a space that facilitates community cohesion. Furthermore, during escalations, members perceived the group as the most trustworthy source of information. The groups’ continuous availability had drawbacks as well. Some participants pointed to digital stress caused by the fear of missing out on information, or by information overload.

Conclusions

Our results demonstrate the effectiveness of digital environments in helping parents cope with a collective stressor: a particularly worthy goal given that social media apps now constitute the primary online connection for most individuals. This has broad impacts on health promotion efforts for mental health issues related to political violence as well as other large-scale health crises such as the COVID-19 pandemic.

Key messages

• Digital environments can serve as a platform for successful coping with collective stressors.

• Health practitioners should consider drawbacks when planning digital support efforts.

Insights into CD24 and Exosome Physiology and Potential Role in View of Recent Advances in COVID-19 Therapeutics: A Narrative Review

Cluster of differentiation (CD) 24, a long-known protein with multifaceted functions, has gained attention as a possible treatment for Coronavirus Disease 19 (COVID-19) due to its known anti-inflammatory action. Extracellular vesicles (EVs), such as exosomes and microvesicles, may serve as candidate drug delivery platforms for novel therapeutic approaches in COVID-19 and various other diseases due to their unique characteristics. In the current review, we describe the physiology of CD24 and EVs and try to elucidate their role, both independently and as a combination, in COVID-19 therapeutics. CD24 may act as an important immune regulator in diseases with complex physiologies characterized by excessive inflammation. Very recent data outline a possible therapeutic role not only in COVID-19 but also in other similar disease states, e.g., acute respiratory distress syndrome (ARDS) and sepsis where immune dysregulation plays a key pathophysiologic role. On the other hand, CD24, as well as other therapeutic molecules, can be administered with the use of exosomes, exploiting their unique characteristics to create a novel drug delivery platform as outlined in recent clinical efforts. The implications for human therapeutics in general are huge with regard to pharmacodynamics, pharmacokinetics, safety, and efficacy that will be further elucidated in future randomized controlled trials (RCTs).

A novel platform for attenuating immune hyperactivity using EXO-CD24 in Covid-19 and beyond

A small but significant proportion of Covid19 patients develop life-threatening cytokine storm. We have developed a new anti-inflammatory drug, EXO-CD24, a combination of an immune checkpoint (CD24) and a delivery platform (exosomes). CD24 inhibits the NF-kB pathway and the production of cytokines/chemokines. EXO-CD24 discriminates Damage- from Pathogen-Associated Molecular Patterns (DAMPs and PAMPs) therefore does not interfere with viral clearance. EXO-CD24 was produced and purified from CD24-expressing 293-TREx™ cells. Exosomes displaying murine CD24 (mCD24) were also created. EXO-CD24/mCD24 were characterized and examined, for safety and efficacy, in vitro and in vivo. In a phase Ib/IIa study, 35 patients with moderate-high severity COVID-19 were recruited and given escalating doses, 10⁸ -10¹⁰ , of EXO-CD24 by inhalation, QD, for five days. No adverse events related to the drug were observed up to 443-575 days. EXO-CD24 effectively reduced inflammatory markers and cytokine/chemokine, though randomized studies are required. EXO CD24 may be a treatment strategy to suppress the hyper-inflammatory response in the lungs of Covid-19 patients and further serve as a therapeutic platform for other pulmonary and systemic diseases characterized by cytokine storm.

An improved molecular inversion probe based targeted sequencing approach for low variant allele frequency

Deep targeted sequencing technologies are still not widely used in clinical practice due to the complexity of the methods and their cost. The Molecular Inversion Probes (MIP) technology is cost effective and scalable in the number of targets, however, suffers from low overall performance especially in GC rich regions. In order to improve the MIP performance, we sequenced a large cohort of healthy individuals (n = 4417), with a panel of 616 MIPs, at high depth in duplicates. To improve the previous state-of-the-art statistical model for low variant allele frequency, we selected 4635 potentially positive variants and validated them using amplicon sequencing. Using machine learning prediction tools, we significantly improved precision of 10–56.25% (P < 0.0004) to detect variants with VAF > 0.005. We further developed biochemically modified MIP protocol and improved its turn-around-time to ∼4 h. Our new biochemistry significantly improved uniformity, GC-Rich regions coverage, and enabled 95% on target reads in a large MIP panel of 8349 genomic targets. Overall, we demonstrate an enhancement of the MIP targeted sequencing approach in both detection of low frequency variants and in other key parameters, paving its way to become an ultrafast cost-effective research and clinical diagnostic tool.

Feasibly of CD24/CD11b as a Screening Test for Hematological Malignancies

An estimated 1.24 million blood cancer cases occur annually worldwide, accounting for approximately 6% of all cancer cases. Currently, there are no standardized hematology cancer screening tests that are recommended for the general population. CD24 is a mucin-like cell surface molecule and P-selectin ligand, which plays a significant role in the maturation of B-lymphocytes and was found to be overexpressed in a number of hematological malignancies. Our primary aim was to assess the sensitivity and specificity of the CD24/CD11b-based blood test for the detection of hematological malignancies. Our cohort included 488 subjects with positive hematological cancer diagnosis (n = 122) and healthy subjects (n = 366). CD24/CD11b expression in peripheral blood leukocytes (PBLs) obtained from blood samples of participants was analyzed by flow cytometry. Our results demonstrated that the average levels of CD24/CD11b in healthy patients (21.7 ± 9.0) were statistically significantly lower compared to levels of CD24/CD11b in cancer patients (29.5 ± 18.7, p < 0.001). The highest levels of CD24/CD11b were found in multiple myeloma (39.1 ± 23.6), followed by chronic myeloid leukemia (33.0 ± 13.7) and non-Hodgkin lymphoma (32.3 ± 13.3). The test had an overall sensitivity for hematologic cancers of 78.5% (95% CI, 70.7-86.3%) and specificity of 80.2% (95% CI, 76.1-84.3%). In conclusion, our findings indicate the feasibility of a CD24/CD11b-based blood test as a screening test of hematological malignancies.

Innovative dual system approach for selective eradication of cancer cells using viral-based delivery of natural bacterial toxin-antitoxin system

The inactivation of p53, a tumor suppressor, and the activation of the RAS oncogene are the most frequent genetic alterations in cancer. We have shown that a unique E. coli MazF-MazE toxin–antitoxin (TA) system can be used for selective and effective eradication of RAS-mutated cancer cells. This out of the box strategy holds great promise for effective cancer treatment and management. We provide proof of concept for a novel platform to selectively eradicate cancer cells using an adenoviral delivery system based on the adjusted natural bacterial system. We generated adenoviral vectors carrying the mazF toxin (pAdEasy-Py4-SV40mP-mCherry-MazF) and the antitoxin mazE (pAdEasy-RGC-SV40mP-MazE-IRES-GFP) under the regulation of RAS and p53, resp. The control vector carries the toxin without the RAS-responsive element (pAdEasy-ΔPy4-SV40mP-mCherry-MazF). In vitro, the mazF-mazE TA system (Py4-SV40mP-mCherry-MazF+RGC-SV40mP-MazE-IRES-GFP) induced massive, dose-dependent cell death, at 69% compared to 19% for the control vector, in a co-infected HCT116 cell line. In vivo, the system caused significant tumor growth inhibition of HCT116 (KRAS^mut/p53^mut) tumors at 73 and 65% compared to PBS and ΔPY4 control groups, resp. In addition, we demonstrate 65% tumor growth inhibition in HCT116 (KRAS^mut/p53^wt) cells, compared to the other two control groups, indicating a contribution of the antitoxin in blocking system leakage in WT RAS cells. These data provide evidence of the feasibility of using mutations in the p53 and RAS pathway to efficiently kill cancer cells. The platform, through its combination of the antitoxin (mazE) with the toxin (mazF), provides effective protection of normal cells from basal low activity or leakage of mazF.

One-stop-shop for cancer screening: A model for the future

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Background: Cancer is the second leading cause of death globally. Early detection will often greatly reduce mortality for many cancers, increase treatment effectiveness, and improve the quality of life for cancer patients, and, by implementing evidence-based prevention strategies, 30–50% of cancers can be prevented. Screening for different cancer types separately is inefficient. A solution is the Integrated Cancer Prevention Center (ICPC), a program with specialists in each discipline who test for multiple cancers during one visit. Methods: This is a prospective cohort study of 17,104 self-referred, asymptomatic patients who visited the Integrative Cancer Prevention Center (ICPC) between January 1, 2006, and December 31, 2019. Clinical, laboratory, and epidemiological data were recorded by multiple specialists. Patients were given follow-up recommendations and diagnoses when appropriate. The primary measure was the detection and staging of new malignant lesions. Secondary measures included cost-benefit and mortality benefit. Results: We screened 8618 men and 8486 women with an average age of 47.11 ± 11.71 years. Of 259 cancers detected through the ICPC, 49 (18.9%) were stage 0, 115 (44.4%) were stage I, 31 (12%) were stage II, 25 (9.7%) were stage III, and 32 (12.4%) were stage IV. Seventeen cancers were missed, only six of which were within the scope of the ICPC, and 189 cancers developed > one year after the last visit to the ICPC. Compared to the stage of detection for cancers in the US, all cancers except for colon were detected at an earlier stage at the ICPC. Lung was the most significant with 86.7% of cancers detected at stage 0, I, or II at the ICPC compared to only 49.3% caught at those stages in the US. Conclusions: This is a proof of concept for a one-stop-shop approach to asymptomatic cancer screening in a multidisciplinary outpatient clinic. It offers evidence that this screening framework can and should be replicated in other healthcare settings and on a national policy level as it saves lives and money. The encouraging results presented here should further the conversation about the utility of screening and add momentum to the movement for increased screening.[Table: see text]

Integrase-derived peptides together with CD24-targeted lentiviral particles inhibit the growth of CD24 expressing cancer cells

The integration of viral DNA into the host genome is mediated by viral integrase, resulting in the accumulation of double-strand breaks. Integrase-derived peptides (INS and INR) increase the number of integration events, leading to escalated genomic instability that induces apoptosis. CD24 is a surface protein expressed mostly in cancer cells and is very rarely found in normal cells. Here, we propose a novel targeted cancer therapeutic platform based on the lentiviral integrase, stimulated by integrase-derived peptides, that are specifically delivered to cancerous cells via CD24 antigen-antibody targeting. INS and INR were synthesized and humanized and anti-CD24 antibodies were fused to the lentivirus envelope. The activity, permeability, stability, solubility, and toxicity of these components were analyzed. Cell death was measured by fluorescent microscopy and enzymatic assays and potency were tested in vitro and in vivo. Lentivirus particles, containing non-functional DNA led to massive cell death (40–70%). Raltegravir, an antiretroviral drug, inhibited the induction of apoptosis. In vivo, single and repeated administrations of INS/INR were well tolerated without any adverse effects. Tumor development in nude mice was significantly inhibited (by 50%) as compared to the vehicle arm. In summary, a novel and generic therapeutic platform for selective cancer cell eradication with excellent efficacy and safety are presented.

Behavioral Characterizing of CD24 Knockout Mouse-Cognitive and Emotional Alternations

CD24 is a small, glycophosphatidylinositol-anchored cell surface protein, mostly investigated with respect to cancer, inflammation, and autoimmune diseases. CD24 knockdown or inhibition has been used to test various biochemical mechanisms and neurological conditions; however, the association between CD24 and behavioral phenotypes has not yet been examined. This study aims to characterize cognitive and emotional functions of CD24 knockout mice (CD24-/-) compared with CD24 wild-type mice at three time-points: adolescence, young adulthood, and adulthood. Our results show that CD24-/- mice exhibited better cognitive performance and less anxiety-like behavior compared with WT mice, with no effect on depression-like behavior. This phenotype was constant from childhood (2 months old) to adulthood (6 months old). The results from our study suggest that CD24 may influence important behavioral aspects at the whole-organism level, which should be taken into consideration when using CD24 knockout models.

High Expression Level of PPARγ in CD24 Knockout Mice and Gender-Specific Metabolic Changes: A Model of Insulin-Sensitive Obesity

Background: The heat-stable HSA/CD24 gene encodes a protein that shows high expression levels in adipocyte precursor cells but low levels in terminally differentiated adipocytes. Its high expression in many types of human cancer suggests an association between cancer, diabetes, and obesity, which is currently unclear. In addition, peroxisome proliferator-activated receptor gamma (PPARγ) is a regulator of adipogenesis that plays a role in insulin sensitivity, lipid metabolism, and adipokine expression in adipocytes. Aim: To assess gender-dependent changes in CD24 KO and its association with PPARγ expression. Experimental approach: WT and CD24 KO mice were monitored from birth up to 12 months, and various physiological and molecular characteristics were analysed. Mean body weight and adipose mass were higher in KO mice than in WT mice. Male, but not female, KO mice showed increased insulin sensitivity, glucose uptake, adipocyte size, and PPARγ expression than WT mice. In addition, enteric bacterial populations, assessed through high-throughput sequencing of stool 16S rRNA genes, were significantly different between male KO and WT mice. Conclusions: CD24 may negatively regulate PPARγ expression in male mice. Furthermore, the association between the CD24 and insulin sensitivity suggests a possible mechanism for diabetes as a cancer risk factor. Finally, CD24 KO male mice may serve as a model of obesity and insulin hyper-sensitivity.

A Dinucleotide Deletion in the CD24 Gene Is a Potential Risk Factor for Colorectal Cancer

BACKGROUND

CD24 is a sialoglycoprotein anchored to the cell surface via glycosylphosphatidylinositol and is involved in intracellular signaling processes. It plays an important role in the early stages of the multistep process of colorectal carcinogenesis. Several single nucleotide polymorphisms in the CD24 gene are reported to exert a diverse effect on cancer risk. We aimed to elucidate whether CD24 TG/del genetic variants are associated with susceptibility to colorectal cancer (CRC).

METHODS

The study included 179 subjects, 36 with CRC (prior to surgery) and 143 healthy control subjects. Deoxyribonucleic acid was purified from peripheral blood leukocytes, and by using restriction fragment length polymorphism analysis, the CD24 gene was genotyped for the specific genetic variant, TG deletion. Additionally, CD24 protein expression levels were determined by Western blotting analysis.

RESULTS

The incidence of the TG/del was higher among the CRC patients compared with healthy controls, 14% and 10%, respectively (P = .54). CD24 protein levels were significantly higher among CRC patients. There were no significant differences in CD24 expression between CRC patients at different stages of the disease or between patients who carry the mutation and those who did not.

CONCLUSIONS

CD24 genetic variant might be of clinical value for risk assessment as part of cancer prevention programs. Further study on larger populations is needed to validate the importance of this dinucleotide deletion in CRC development. Overexpression of CD24 protein occurs early along the multistep process of CRC carcinogenesis, and a simple blood sample based on CD24 expression on peripheral blood leukocytes can contribute to early diagnosis.

The dark age of single organ screening is over: CD24 is a novel universal simple blood test for early detection of cancer

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Background: More than 1.8 million new cancer cases are expected to be diagnosed in 2020. Only in the U.S, about 606,520 Americans are expected to die this year, which translates to about 1,660 deaths per day. However, when found early, in the asymptomatic phase, cancer is often effectively treated or even cured. The few cancer screens available today, including mammograms and colonoscopies, each look for a single type of cancer. CD24 is hardly expressed in normal cells (but to B-lymphocytes, differentiating neuroblasts and neutrophils) but is overexpressed in numerous human cancers. Aim: To establish a universal cancer screening blood test. Methods: Blood samples were obtained from consecutive patients and healthy volunteers. 1x106 leukocytes were stained using anti-CD11b-PerCp-Cy5.5 and anti-CD24-FITC and analyzed by flow cytometry (CyFlow Cube 6, Sysmex, Germany). Percentage of positive cells was determined by subtracting the percentage of CD24 and CD11b-positive cells (dual stain) from CD24-positive cells (single stain). The cut off for cancer detection was 25. Healthy subjects underwent a thorough evaluation at the health promotion center and integrated cancer prevention center. All cancers were verified histologically. Results: CD24/CD11b expression in the healthy population was evaluated in 337 women and 408 men, ages 20-85. There were 222 cancer patients. After excluding thyroid and bladder cancers, the assay detected 146 out of 196 (75%) cancers at all stages and even in 31 out of colonic adenomas (table). The levels of CD24 drop back to near normal level following successful surgery/chemotherapy. The test score was not affected by age, gender, fasting and the time of the day that the blood sample is taken. In 55 cases the test was performed twice, with similar results, as well as when the test was performed in another flow cytometry, after 1d, 1w, 1m after freezing . Conclusions: 1. CD24 is a universal cancer screening. 2. It can detect pre malignant lesions like adenomas in the colon. 3. Preliminary results suggest that it can serve as a predictive marker. [Table: see text]

Abstract 2297: Anti-labyrinthin monoclonal antibody reduces human adenocarcinoma circulating tumor cells in the blood of patient-derived xenograft models and inhibits the growth of adenocarcinoma cell cultures

Labyrinthin is a 255-amino acid protein antigen that is expressed on the cell-surface of most adenocarcinoma tumors and is not expressed on the surface of most normal cells, which makes it an attractive candidate for targeted therapy. Originally, labyrinthin had been deduced to be a product of a large deletion in the gene coding for junctate. We found that the junctate gene in labyrinthin-expressing adenocarcinoma cells does not have any deletion, and we propose that the labyrinthin protein is a splice variant of the junctate gene. This study aimed to determine the effects of an anti-labyrinthin monoclonal antibody, on adenocarcinoma cells in vitro and on patient-derived xenograft (PDX) models in vivo. Lung, breast and colorectal adenocarcinoma cell lines, as well as a primary-cell culture of a colorectal adenocarcinoma patient, were assessed for cell surface expression of labyrinthin. The cells were then incubated in the presence of the anti-labyrinthin antibody and growth rate was monitored by live imaging methods. Untreated primary-cell cultures of the colorectal adenocarcinoma patient were also grafted to immunodeficient mice to produce PDX tumors. When establishment of palpable tumors was observed, the mice were injected with the antibody. Peripheral blood was sampled from the mice and circulating tumor cells (CTCs) were quantified by flow cytometry. A significant reduction of approximately 60% was detected in the number of CTCs in the peripheral blood of the antibody-treated PDX mice compared to untreated control PDX mice. Additionally, a significant reduction was measured in the growth-rate of cultured primary cells and in lung, breast and colorectal adenocarcinoma cell lines in the presence of the antibody. We conclude that the anti-labyrinthin antibody has an inhibitory effect on the formation of adenocarcinoma CTCs in vivo as well as on the growth rate of cultured adenocarcinoma tumor cells.

Citation Format: Natalia Saleev, Netta R. Blondheim-Shraga, Evgeny Solomonov, Shiran Shapira, Izhak Haviv, Solomon M. Stemmer, Hanoch Slor. Anti-labyrinthin monoclonal antibody reduces human adenocarcinoma circulating tumor cells in the blood of patient-derived xenograft models and inhibits the growth of adenocarcinoma cell cultures [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2297.

Pancreatic cancer in bloom syndrome

Bloom syndrome is a rare autosomal recessive disorder characterized by distinct physical features, such as short stature, genomic instability, and predisposition to numerous cancers. The BLM gene encodes for the RecQ helicase that plays an important role in genome editing, maintenance, and stability. Mutations in the BLM gene cause genomic instability that exposes the carriers to a variety of cancers, and in particular hematological and gastrointestinal cancers. Herein, we report the first case of pancreatic cancer in a 32-year-old patient with bloom syndrome.

Innovative dual system for selective eradication of cancer cells using exosomes carrying natural bacterial toxin-antitoxin (TA)

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Background: Inactivation of P53 and activation of ras are frequent genetic alterations in cancer. We have shown in vitro and in vivo, that the TA system can selectively and effectively eradicate RAS-mutated cancer cells. Aim: Selective killing of cancer cells while sparing the normal cells based on tumor genetic signature. Methods: A “first generation” ΔE1/ΔE3 human type-5 adenoviral-vectors for gene delivery were designed and constructed to specifically target cancer cells. They are designated as "PY4-mazF-mCherry" (PY4, ras responsive element), "ΔPY4-mazF-mCherry" (control viruses) and "RGC-mazE-IRES-GFP" (RGC, P53 responsive element). Their potency was tested in vitro, by the enzymatic MTT assay, microscopic observation, colony formation assay and FACS analysis, and in a xenograft model of CRC. Next, we generated, small natural vesicles, exosomes, that directly targeted cancer through specific small antibody fragments against CD24 that is expressed in most cancer cells and rarely on normal cells. Results: The TA system ("PY4-mazF-mCherry"+"RGC-mazE-IRES-GFP") induced a massive cell death, in a dose-dependent manner in vitro, 69% as compared to 19% in control co-infected ("ΔPY4-mazF-mCherry"+"RGC-mazE-IRES-GFP") HCT116 CRC cells (mutated RAS and p53). In vivo, growth of HCT116-/- ( KRASmutand P53mut) and HCT116+/+ ( KRASmut and P53wt) tumors were significantly inhibited (70% and 65%, respectively). Conclusions: 1. Abusing the P53 genetic status and the activated Ras pathway holds promising effective and safe strategy to target tumor cells while sparing normal tissues. 2. It is a proof of concept for personalized cancer therapy based on the tumor genetic profile.

The chick embryo chorioallantoic membrane assay: In ovo model for personalized assessment and evaluation of the most effective therapeutic approach in cancer therapy

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Background: "Personalized medicine,” is the tailoring of medical treatment to a single person aiming to maximize efficacy and minimize toxicity. Currently there is no good prediction for response to therapy. The Chick Chorioallantoic Membrane (CAM) is naturally immuno-deficient and rich in vascularity therefore an ideal system, allowing generate 3D cancerous “organoids” in a very efficient, reproducible and cost-effective manner and translates basic research to the clinic. Aims: Generate a “personalized” HTP system for a quick, reliable and effective evaluation of different therapeutic options using 3D tumors in a "humanized egg" instead of mouse PDX model. Methods: Fertilized eggs were incubated until day 3 (37°C, 75-90% humidity). Then, 2ml of albumin was pulled out to separate the CAM from the eggshell and a small window in the eggshell has been made. To destroy the chicken immune system development, the eggs were irradiated at day 5 and human immune cells were then inoculated onto the CAM. On day 7, single cells suspension or tissues, derived from cancer patients, were transplanted onto the CAM and visible tumors were performed ("CAM-PDX"). Drugs, mAbs and chemotherapy, were applied via the yolk sac. Tumor growth was measured, weighted and monitored by caliper and IVIS fluorescent imaging platform. IHC was performed and confirmed the response of the particular specimens to the tested regiment. Results: Histology and IHC analysis confirmed that the established tumors retained their characteristics. Positive Ki-67 staining confirmed that cancer cells proliferate while the treated tumors showed reduced staining. Anti-CD24 mAb, FOLFOX, cetuximab, Foflorinox and Gemcitabine, given as single agent or combinations, successfully inhibited CR and pancreatic tumors (by 70-75%). Detection of active caspase 3 confirmed those results. Biopsies from human specimens, were successfully established and expanded by serial passages allows generation of bio-bank. The stimulated human PBMCs demonstrated enhanced proliferation in vitro and in ovo, even after 5 days in the egg. Irradiated eggs showed no functional immune system even after 2 weeks of development. Conclusions: The CAM is an ideal, effective, economical and powerful avatar-based precision medicine approach to predict the best protocol for cancer therapy.

Data from an integrated cancer prevention center screening for multiple cancer types

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Background: Cancer is the second leading cause of death globally, and was responsible for ~9.6 million deaths in 2018. Importantly, between 30–50% of cancers can be prevented by avoiding risk factors and implementing existing evidence-based prevention strategies. Methods: We present the results of 15758 adults who came to our clinic between 2006 and 2018. Patients were counseled on reducing risk factors and screened for early detection of 11 of the most common cancer types. Patients were examined by specialists in internal medicine, surgery, plastic surgery, OBGYN, urology, oncology, oral surgery, gastroenterology, and others. Women underwent vaginal US, pap smear, mammography (40yr) and US/MRI of the breast with a clinical indication. Men underwent PSA/free PSA ( > 40yr). LDCT for moderate smokers. Colonoscopy was recommended to all subjects ( > 40yr). Results: A total of 7900 (50.1%) men and 7857 women (49.9%) mean age 46.9±11.3 years were screened. A total of 418 (2.7%) malignant lesions were detected in patients who had been screened, 245 (1.6%) of which were detected through our screening: skin 66 (0.4%), prostate 30 (0.2%), thyroid 28 (0.2%), breast 28 (0.2%), colorectal 19 (0.1%), urinary 13 (0.08%), lung 11 (0.07%), cervical 11 (0.07%), other/unknown 9 (0.06%), hematologic 8 (0.05%), ovarian 5 (0.03%), uterine 5 (0.03%), pancreas 3 (0.02%), testicular 3 (0.02%), oropharyngeal 2 (0.01%), hepatobiliary 2 (0.01%), stomach 1 (0.01%), larynx 1 (0.01%). A total of 17 (0.1%) malignant lesions were missed: breast 3 (0.02%), colorectal 3 (0.02%), skin 2 (0.01%), thyroid 2 (0.01%), hematologic 2 (0.01%), pancreas 2 (0.01%), kidney 1 (0.01%), lung 1 (0.01%), brain 1 (0.01%). A total of 147 (0.9%) malignant lesions developed > 1year after a visit. Only forty-nine of the cancer patients (12.5%) died after 18.9±17.8 months at a mean age of 66.5±12.2 years. Significantly, better than the expected cancer mortality in general. First-degree family member with cancer (HR = 1.46) and advanced age (HR = 21.8) was associated with increased cancer risk (P < 0.05). Conclusions: One stop shop cancer screening, in the setting of a multidisciplinary outpatient clinic is feasible, can detect cancer at an early stage, and can significantly improve survival.

Activated Eosinophils Exert Antitumorigenic Activities in Colorectal Cancer

Immunotherapies targeting T lymphocytes are revolutionizing cancer therapy but only benefit a subset of patients, especially in colorectal cancer. Thus, additional insight into the tumor microenvironment (TME) is required. Eosinophils are bone marrow-derived cells that have been largely studied in the context of allergic diseases and parasite infections. Although tumor-associated eosinophilia has been described in various solid tumors including colorectal cancer, knowledge is still missing regarding eosinophil activities and even the basic question of whether the TME promotes eosinophil recruitment without additional manipulation (e.g., immunotherapy) is unclear. Herein, we report that eosinophils are recruited into developing tumors during induction of inflammation-induced colorectal cancer and in mice with the Apc^{min /+} genotype, which develop spontaneous intestinal adenomas. Using adoptive transfer and cytokine neutralization experiments, we demonstrate that the TME supported prolonged eosinophil survival independent of IL5, an eosinophil survival cytokine. Tumor-infiltrating eosinophils consisted of degranulating eosinophils and were essential for tumor rejection independently of CD8⁺ T cells. Transcriptome and proteomic analysis revealed an IFNγ-linked signature for intratumoral eosinophils that was different from that of macrophages. Our data establish antitumorigenic roles for eosinophils in colorectal cancer. These findings may facilitate the development of pharmacologic treatments that could unleash antitumor responses by eosinophils, especially in colorectal cancer patients displaying eosinophilia.

Design Principles for Bispecific IgGs, Opportunities and Pitfalls of Artificial Disulfide Bonds

Bispecific antibodies (bsAbs) are antibodies with two binding sites directed at different antigens, enabling therapeutic strategies not achievable with conventional monoclonal antibodies (mAbs). Since bispecific antibodies are regarded as promising therapeutic agents, many different bispecific design modalities have been evaluated, but as many of them are small recombinant fragments, their utility could be limited. For some therapeutic applications, full-size IgGs may be the optimal format. Two challenges should be met to make bispecific IgGs; one is that each heavy chain will only pair with the heavy chain of the second specificity and that homodimerization be prevented. The second is that each heavy chain will only pair with the light chain of its own specificity and not with the light chain of the second specificity. The first solution to the first criterion (knobs into holes, KIH) was presented in 1996 by Paul Carter's group from Genentech. Additional solutions were presented later on. However, until recently, out of >120 published bsAb formats, only a handful of solutions for the second criterion that make it possible to produce a bispecific IgG by a single expressing cell were suggested. We present a solution for the second challenge-correct pairing of heavy and light chains of bispecific IgGs; an engineered (artificial) disulfide bond between the antibodies' variable domains that asymmetrically replaces the natural disulfide bond between CH1 and CL. We name antibodies produced according to this design "BIClonals". Bispecific IgGs where the artificial disulfide bond is placed in the CH1-CL interface are also presented. Briefly, we found that an artificial disulfide bond between V_H position 44 to V_L position 100 provides for effective and correct H-L chain pairing while also preventing the formation of wrong H-L chain pairs. When the artificial disulfide bond links the CH1 with the CL domain, effective H-L chain pairing also occurs, but in some cases, wrong H-L pairing is not totally prevented. We conclude that H-L chain pairing seems to be driven by V_H-V_L interfacial interactions that differ between different antibodies, hence, there is no single optimal solution for effective and precise assembly of bispecific IgGs, making it necessary to carefully evaluate the optimal solution for each new antibody.

Abstract 1168: The “humanized” chicken embryo chorioallantoic membrane (CAM) as a personalized platform for high-throughput (HTP) screening of cancer therapeutics

Background

Every day, millions of people are taking medications that will not help them. “Personalized medicine,” is the tailoring of medical treatment to a single person, shape his response to a particular treatment and aims to better target intervention, maximize benefit and minimize harm. Several techniques are available to grow primary cell cultures from tumors; however, very few have been found to be promising. Novel, cost-effective model that similarly mimic tumor biology and provide faster information on the activity of anticancer therapies could therefore make an important contribution to the advancement of personalized medicine. Chick Chorioallantoic Membrane (CAM) assays have been used to study the process and therapeutics involving angiogenesis, tumor cell invasion and metastasis. The CAM is naturally immuno-deficient and rich in vascularity therefore an ideal system, allowing to generate 3D cancerous “organoids” in a very efficient, reproducible and cost-effective manner and translates basic research to the clinic.

Aim

1) Generate a “personalized medicine” HTP system for a quick and reliable evaluation of the effectiveness of different therapeutic options on of 3D "organoid" tumors; 2) Using the "humanized egg" as a low-cost and highly efficient mimetic of the mouse PDX model ".

Methods

Fertilized eggs were incubated until day 3 (37°C, 75-90% humidity). 2ml of albumin was pulled from the egg to separate the CAM membrane from the egg shell. Then, a small window in the egg shell has been made, and resealed with adhesive tape. On day 7, 3-5x106 tumor cells were transplanted onto the CAM membrane. The cancer cells become a visible tumor after 3 days. Different therapeutics (such as Erbitux, anti-CD24 mAb) were tested. Tumor growth was monitored by "live imaging" device.

Results

The efficiency and reproducibility of human cancer cell lines engraftment has been demonstrated. LV-GFP-Puro plasmid was constructed and used to generate GFP-encoded lentiviruses which then were used to generate a stable colorectal cancer cell line expressing GFP. The CAM tumors were evaluated histopathologicaly and IVIS fluorescent imaging.

Anti-CD24 mAb inhibited tumor growth by ~70%.The presence of the humanized mAb in the engrafted tissue was confirmed by western blot analysis and IHC.

Conclusions

The ability to evaluate ex-vivo cancer tissue response to potential therapeutics in “humanized” settings within days is a very powerful tool.

Citation Format: Shiran Shapira, Oren Bogin, Nadir Arber. The “humanized” chicken embryo chorioallantoic membrane (CAM) as a personalized platform for high-throughput (HTP) screening of cancer therapeutics [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 1168.

Abstract 5922: "Gammora": Selective killing of cancer cells bearing CD24 by viral integrase

The HIV integrase is important in the integration of viral DNA to the host genome resulting in double-stranded breaks (DSB). Only 1-2 copies are integrated, due to inhibition of HIV-1 Rev protein, making the cells invisible to the immune system. CD24 is mostly expressed on cancer and not normal cells. We hypothesize that specific targeting of the viral particles using mAb to CD24 together with stimulating the enzyme activity and increasing the frequency of integration events, would increase the occurrence of DSB, that will lead to genomic instability, and ultimately to apoptosis of the target cells.

Aim

To develop a therapeutic platform, for selective eradication of cancer cells, which consists of targeted lentivirus particles and IN-derived peptides.

Methods

Integrase derived peptides (designated as INR2 and INS) were synthesized. Humanized anti-CD24 antibody (scFv) was engineered and fused to the lentivirus envelope. Stability, solubility and toxicity of the peptides were analyzed by HPLC-MS and MTD, respectively, as well as their activity and permeability into cells. Cell death was measured qualitatively by fluorescent microscopy and quantified by the enzymatic MTT assay. Colorectal, pancreatic and lung cancer cells were used for testing the potency of the lentiviral-based system. The efficacy of the suggested system was assessed in vivo, in nude mice bearing xenografts of lung cancer. The mice were treated systemically twice weekly.

Results

INS and INR2 stimulate viral integrase in vitro. A single IV administration of INR2 and INS was well tolerated without adverse effects. These lentivirus particles contain nonfunctional DNA with flanked LTRs allowing their integration into the target cells DNA and formation of DSB due to the action of the integrase whose activity was stimulated by the IN-derived peptides. Massive cell death (40-70%) in a dose-

dependent manner was achieved. Raltegravir, an antiretroviral FDA-approved drug, was able to inhibit cell death (2-3 times). In vivo, the INR2 and INS combination led to a significant reduction (50%) in tumor volume. Live imaging (IVIS device) of the tumors and selected organs confirmed that the viruses indeed reach the tumor after systemic injection and that the anti-CD24 enhanced the selectivity of infection.

Conclusions

The use of IN-derived peptides together with the CD24-targeted lenti-therapy approach suggests a novel strategy that specifically promotes killing and removal of a wide range of cancer cells.

Citation Format: Shiran Shapira, Eynat Finkelshtein, Abraham Loyter, Nadir Arber. "Gammora": Selective killing of cancer cells bearing CD24 by viral integrase [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 5922.

Selective eradication of cancer cells by delivery of adenovirus-based toxins

Background and objective

KRAS mutation is an early event in colorectal cancer carcinogenesis. We previously reported that a recombinant adenovirus, carrying a pro-apoptotic gene (PUMA) under the regulation of Ets/AP1 (RAS-responsive elements) suppressed the growth of cancer cells harboring hyperactive KRAS. We propose to exploit the hyperactive RAS pathway, rather than to inhibit it as was previously tried and failed repeatedly. We aim to improve efficacy by substituting PUMA with a more potent toxin, the bacterial MazF-MazE toxin-antitoxin system, under a very tight regulation.

Results

A massive cell death, in a dose-dependent manner, reaching 73% at MOI 10 was seen in KRAS cells as compared to 22% in WT cells. Increase expression of MazE (the anti-toxin) protected normal cells from any possible internal or external leakage of the system and confirmed the selectivity, specificity and safety of the targeting system. Considerable tumor shrinkage (61%) was demonstrated in vivo following MazEF-encoding adenovirus treatment without any side effects.

Design

Efficient vectors for cancer-directed gene delivery were constructed; “pAdEasy-Py4-SV40mP-mCherry-MazF”“pAdEasy-Py4-SV40mP-mCherry-MazF-IRES-TetR-CMVmp-MazE-IRES-EGFP“,“pAdEasy-ΔPy4-SV40mP-mCherry-MazF-IRES-TetR-CMVmp-MazE-IRES-EGFP “and “pAdEasy-mCherry”. Virus particles were produced and their potency was tested. Cell death was measured qualitatively by using the fluorescent microscopy and colony formation assay, and was quantified by MTT. FACS analysis using annexin V and RedDot2 dyes was performed for measuring apoptotic and dead cells, respectively. In vivo tumor formation was measured in a xenograft model.

Conclusions

A proof of concept for a novel cancer safe and effective gene therapy exploiting an aberrant hyperactive pathway is achievable.

Oncologists' identification of mental health distress in cancer patients: Strategies and barriers

The purpose of this research was to examine oncologists' perspectives on indicators of mental health distress in patients: what strategies they use to identify these indicators, and what barriers they face in this task. Twenty-three oncologists were interviewed, and the grounded theory method of data collection and analysis was used. Oncologists perceived distress to be a normative part of having cancer and looked for affective, physical, verbal and behavioural indicators using a number of strategies. Barriers to identification of mental health distress included difficulty in differentiating between mental health distress and symptoms of the disease, and lack of training. A systematic, time-efficient assessment of symptoms of emotional distress is critical for identification of psychiatric disorders among patients and differentiating normative emotional responses from psychopathology. Clinical bias and misdiagnosis can be a consequence of an ad hoc, intuitive approach to assessment, which can have consequences for patients and their families. Once elevated risk is identified for mental health distress, the patient can be referred to specialised care that can offer evidence-based treatments.

Of mice and men: a novel dietary supplement for the treatment of ulcerative colitis

BACKGROUND

Curcumin, green tea polyphenols and selenium possess anti-inflammatory and anti-oxidant properties. Individually they have demonstrated some efficacy in animal models and human subjects with inflammatory bowel disease (IBD). To evaluate the efficacy and safety of Coltect [Curcumin (500 mg), green tea (250 mg) and selenium (100 µg)] in vivo and in patients with ulcerative colitis (UC).

METHODS

Each component was compared to placebo in a DSS mice colitis model. The efficacy was validated in a 2,4,6-trinitrobenzenesulfonic acid (TNBS) rat colitis model. Twenty patients with mild-to-moderate UC received two Coltect tablets twice daily for 8 weeks. Enrollees underwent sigmoidoscopy at study entrance and closure, and physical and laboratory evaluation at baseline, 4 and 8 weeks.

RESULTS

Coltect showed a synergistic therapeutic effect in the DSS and TNBS models. Disease activity was significantly higher in the placebo versus the treated group (p < 0.05). Selenium was the more active component. The contribution of green tea was minor. In the TNBS model, the Wallace scores for macroscopic lesions were 4.8 ± 1.5 (treatment) and 8.2 ± 0.5 (placebo) (p = 0.01). In humans, Coltect was well tolerated and effective. Fourteen subjects (70%) improved: nine (45%) went into complete remission, four (20%) experienced marked improvement and one (5%) experienced moderate improvement at the end of the trial. Clinical activity index decreased significantly at 4 and 8 weeks (p < 0.001). Two patients had no change in their symptoms, and one withdrew after 4 weeks. Flare-up in four subjects caused three to withdraw from the study after less than 4 weeks. Endoscopic improvement was observed in 11 (69%) patients, and four patients (25%) achieved complete remission.

CONCLUSIONS

Coltect may serve as a first-line or add-on therapy in patients with mild-to-moderate UC.

Ten year experience of an integrated cancer prevention center screening for multiple cancer types

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Background: Cancer is the leading cause of mortality worldwide. Prevention and early detection are pivotal tools for reducing cancer burden. Methods: We describe the 10 year experience (2006-2016) of an integrated cancer prevention center that provides screening for prevention and early detection of 11 most common cancer types. Healthy individuals (20-80 yr) were included. Extensive clinical and epidemiological data was obtained. DNA was extracted from all participants and genotyped for APC I1307K and E1317Q. Patients were examined by specialists in internal medicine, surgery, plastic surgery, OBGYN, urology, oncology, oral surgery, gastroenterology, and others. Women underwent vaginal US and pap smear and (40yr) mammography and US/MRI with a clinical indication. PSA and free PSA for Men ( > 40yr). LDCT for heavy smokers. Colonoscopy was recommended to all subjects ( > 40yr). Results: A total of 6258 (49%) men and 6461 (51%) women mean age 47.0±11.5 year were screened. New malignant lesions were detected in 389 (1.75%) of screeners. The most common cancers were of skin (74, 0.6%), prostate (62, 0.5%), thyroid (51, 0.4%), breast (36, 0.3%), colorectal (22, 0.2%), ovarian (19, 0.1%), uterus (14, 0.1%), testis (12, 0.09%) urinary (9, 0.07%) and lung (10, 0.08%). In 28 patients (0.22%) more than one cancer was detected. Twenty eight of the cancer patients (7.2%) died after 32.4±28.1 months at a mean age of 69.4±14.2 years. Significantly, better than the expected cancer mortality. The APC I1307K and E1317Q variants were detected in 572 (4.8%) and 182 (1.5%) subjects respectively. First degree family member with cancer (OR = 2.02), I1307K carrier ship (OR = 1.53), female gender (OR = 1.23) and advanced age (OR = 1.06) were all associated with statistically significant (P < 0.05) increased cancer risk. Advanced age and first degree family history were also associated with detection of more than one cancer types. Conclusions: One stop shop screening, in the setting of a multidisciplinary outpatient clinic, is feasible and can prevent and detect cancer at an early stage. It significantly improve morbidity and mortality. Impressively the APC I1307K carries an overall increase cancer risk.

Abstract 3854: Successful selective eradication of colorectal cancer cells by adenovirus-based delivery of toxins

Background: K-Ras gene mutation is an early event in the development of colorectal cancer (CRC) and occurs in ∼50% of CRC cases. We propose a strategy that exploits the Ras hyperactive pathway, rather than inhibiting it as was tried and failed many times. We have previously reported that recombinant adenovirus, carrying a pro-apoptotic gene under the regulation of Ras-responsive elements (Ets/AP1), suppressed the growth of cancer cells displaying hyperactive K-Ras (Biomed Pharm, 2005,Cancer Gene Ther,2012, Exp Cell Res,2012). TA systems are evolutionarily successful entities that are prevalent in lower organisms and play important roles in a diverse range of cellular activities.

im: To establish a tight control and improved ras responsive element based on the bacterial MazEF system

Methods: Efficient vectors for cancer-directed gene delivery were constructed and cloned into a “first generation” ΔE1/ΔE3 human type-5 adenoviral-vector. Virus particles were produced, their titer was calculated by the End-Point Dilution Assay (EPDA) and their potency was tested. Cell death was measured qualitatively by using the fluorescent microscopy and colony formation assay, and was quantified by MTT. FACS analysis using annexin V and RedDot2 dyes was performed for measuring apoptosis and dead cells, respectively. In vivo tumor formation was measured in xenograft model. Ad-Py4-SV40-MazEF and Ad-ΔPY4-CMV-MazEF viruses (1×109pfu) or PBS were administrated intraperitoneal twice with a 3-day interval between injections.

Results: Adenovirus therapy induced massive cell death, in a dose-dependent manner; 73% with a titer of 10 MOI in cells with activated K-Ras as compared to 22% in tumor cells having the WT K-Ras. The cytotoxic effect was confirmed qualitatively by colony formation assay. In the absence of K-ras-responsive DNA element increase expression of MazE, the anti-toxin, protected normal cells from any possible internal or external leakage of the system and confirmed the selectivity, specificity and safety of the targeting system. FACS analysis confirmed massive cell death, 55% apoptosis and 82% dead cells, following infection with the full toxin-antitoxin encoding viruses.

Control viruses lacking the K-ras responsive element a modest toxicity was seen (18% and 10%, respectively). Impressive tumor shrinkage was demonstrated in vivo following treatment with Ad-Py4-SV40-MazEF-encoding adenovirus (61%) without any toxic or side effects. Ad-ΔPY4-SV40-MazEF treated mice (control group) tumor volume was reduced only by 27% (P&lt;0.05). No growth inhibition was seen following injection of PBS.

Conclusions: A proof-of-concept for a novel cancer gene therapy by exploiting aberrant K-Ras hyperactive pathway was successfully demonstrated. The lack of toxicity holds promise for effective and safe therapy of human cancers carrying K-Ras mutations.

Citation Format: Shiran Shapira, Assaf Shapira, Dina Kazanov, Ilana Nabiochtchikov, Sarah R. Kraus, Nadir Arber. Successful selective eradication of colorectal cancer cells by adenovirus-based delivery of toxins. [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 3854.

Abstract 3805: A novel anti-CD24 monoclonal antibody, humanized and affinity maturated for targeting gastrointestinal cancers

Background: CD24 is a cell-surface heavily glycosylated GPI-anchored protein. We had previously shown that CD24 in an important player in the multistep process of GI carcinogenesis (Gastro 2006, Clin Can Res 2007, Can Res 2008). The creation of chimeric, humanized or fully human antibodies was a major breakthrough and led to a wave of US FDA-approved antibodies.

Aim: To further improve the efficacy of the humanized anti-CD24 mAb by increasing its binding strength and thereby generating a novel therapy tool for GI malignancy

Methods: From murine to humanized, unarmed and conjugated, small derivatives and full IgG antibodies were recombinantly engineered. The antibody genes were recovered, amplified and cloned into appropriate vectors. Then the vectors were introduced into a host (mammalian and E.coli) and adequate amounts of functional antibody were achieved. Sequence analysis of the CDR loops was the base for library designing. Affinity maturation was performed in two-steps selection (CDR walking) and by using phage display technique. The binding of the different derivatives were evaluated on full Glycan array in which more than 70 sugar moieties were printed.

Results: In vivo antibody targeting and accumulation within a CD24 positive tumor and its excess clearance was clearly demonstrated using live imaging device (Maestro Cri device). High-affinity antibodies were selected and created from combinatorial phage-displayed antibody libraries that contain varying degrees of diversity at randomized positions. A chosen matured clone was isolated and showed higher binding strength (1.8×10-8), compared to the parental murine and humanized Abs. The matured antibody showed selective recognition and binding to the CD24 antigen which proves that the genetic manipulations carried out did not affect its properties. Its stability was enhanced following the maturation process,as well as its pharmacokinetics parameters which showed a long serum half-life.The matured antibody mediates ADCC (antibody-dependent cell cytotoxicity), 75% of target cell lysis was demonstrated. Combined treatment with standard chemotherapy and natural products, such as monoterpenes (terpinen-4-ol), showed significant reduction in cell viability (90% cell death). Binding of anti-CD24 Ab to glycan microarray could not be detected while high binding intensities were observed where the whole CD24 protein was printed, indicating that the antibodies bind to the core peptide and not to its sugar residues.

Conclusion: Targeting CD24 may be a promising treatment for GI malignancies in combination with chemotherapy and natural agents. The resulted matured humanized anti-CD24 mAb proved to be more effective than the murine parental Ab. The long serum half-life is desirable as it would decrease the need for repetitive injections.

Citation Format: Shiran Shapira, Dina Kazanov, Vered Padler Karavani, Itai Benhar, Nadir Arber. A novel anti-CD24 monoclonal antibody, humanized and affinity maturated for targeting gastrointestinal cancers. [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 3805.

Long-Term Study of Brain Lesions Following Soman, in Comparison to DFP and Metrazol Poisoning

The long-term histopathological effects of acute lethal (95 μg kg-1) and sublethal (56 μg kg-1) doses of soman were studied in rats and were compared to lesions caused by equipotent doses of either another cholinesterase (ChE) inhibitor, DFP (1.8 mg kg-1), or a non-organophosphorus convulsant, metrazol (100 mg kg-1). Severe toxic signs were noted following one LD50 dose administration of all the compounds, yet only soman induced brain lesions. Moreover, even when administered at a sublethal dose (0.5 LD50), soman induced some histological changes without any clinical signs of intoxication.

Soman-induced brain lesions were assessed quantitatively using a computerized image analyser. The analysis was carried out for up to 3 months following administration, and a dynamic pattern of pathology was shown. The cortical thickness and area of CA1 and CA3 cells declined significantly as early as 1 week post-exposure. No pathological findings were detected following DFP and metrazol administration. It is therefore suggested that brain lesions are not common for all ChE inhibitors and that convulsions per se are not the only factor leading to brain damage following the administration of soman. The degenerative process (found also with the sublethal dose of soman) might be due to a secondary effect, unrelated to soman's clinical toxicity, but leading to long-term brain injuries.

Terpinen-4-ol: A Novel and Promising Therapeutic Agent for Human Gastrointestinal Cancers

Background

Terpinen-4-ol, a naturally occurring monoterpene is the main bioactive component of tea-tree oil and has been shown to have many biological activities.

Aim

To study the antitumor effects of terpinen-4-ol and its mechanism of action in prostate and GI malignancies, alone and in combination with chemotherapeutic and biological agents.

Methods

Terpinen-4-ol was administrated alone or combined with standard chemotherapy (Oxaliplatin, Fluorouracil, Gemcitabine, Tarceva) and biological agent (Cetuximab). It was also combined with humanized anti-CD24 mAbs (was developed by us). Killing effects were measured qualitatively by light microscopy and quantitatively using the MTT and FACS analysis, following treatment of colorectal, pancreatic, gastric and prostate cancer cells. Terpinen-4-ol effect on tumor development was evaluated in xenograft model.

Results

Terpinen-4-ol induces a significant growth inhibition of colorectal, pancreatic, prostate and gastric cancer cells in a dose-dependent manner (10–90% in 0.005–0.1%). Terpinen-4-ol and various anti-cancer agents (0.2μM oxaliplatin and 0.5μM fluorouracil) demonstrated a synergistic inhibitory effect (83% and 91%, respectively) on cancer cell proliferation. In KRAS mutated colorectal cancer cells, which are resistant to anti-EGFR therapy, combining of terpinen-4-ol with cetuximab (1 μM) resulted in impressive efficacy of 80–90% growth inhibition. Sub-toxic concentrations of terpinen-4-ol potentiate anti-CD24 mAb (150μg/ml)-induced growth inhibition (90%). Considerable reduction in tumor volume was seen following terpinen-4-ol (0.2%) treatment alone and with cetuximab (10mg/kg) (40% and 63%, respectively) as compare to the control group.

Conclusion

Terpinen-4-ol significantly enhances the effect of several chemotherapeutic and biological agents. The possible molecular mechanism for its activity involves induction of cell-death rendering this compound as a potential anti-cancer drug alone and in combination in the treatment of numerous malignancies. Terpinen-4-ol restores the activity of cetuximab in cancers with mutated KRAS.

Ambulatory physical activity during the initial training phase in a Naval Commando Unit

BACKGROUND

There is a positive correlation between the volume of physical activity performed and the incidence of lower extremity overuse injuries. Difficulty in evaluating the amount of activity in which highly specialised military units are engaged has prevented the implementation of a strict training programme designed to minimise overuse injuries.

PURPOSE

To quantify the ambulatory physical activity performed by trainees during the initial training phase in a Naval Commando Unit, with a view to developing more exact physical performance guidelines for the unit and the Israel Defense Forces, in general.

METHODS

Twenty-four accelerometers were worn by two teams each day. Trainees were instructed to wear the device on their non-dominant wrist 24 h a day, during all types of activities. Twice a week, the devices were collected, checked for damage and recharged, and the data were transferred to a computer.

RESULTS

Six trainees failed to complete the 9-week training period. Of the total 1512 accelerometer-days, 1075 readings (71%) were included in the study data. Trainees ambulated on average a distance of 15.5±8.61 km/day and 95.5 km/week. Accelerometer readings (estimated distances) were averaged each week for the two teams. The total distance measured over the 9-week study period was 911.15 km in team A and 808.38 km in team B. The total distance measured in both teams was, thus, almost double the planned 440 km (p=0.001).

CONCLUSIONS

Trainees greatly exceeded the planned safe distance. High variability was observed between trainees from the same team.

The APC I1307K allele conveys a significant increased risk for cancer

This study is the first attempt to evaluate the association between the APC I1307K variant and overall cancer risk. It is unique in both its large sample size and in the reliability of data in the control group. The findings described in this article have major implications in terms of identifying asymptomatic individuals who are at increased risk to harbor cancer and therefore targeted to be enrolled in specific early detection and prevention programs. The prevalence of the APC I1307K missense mutation among Ashkenazi Jews is ∼ 6%. Carriers are at an increased risk for colorectal neoplasia. In this study, we examined the association of this variant with non-colorectal cancers. Consecutive 13,013 healthy subjects who underwent screening at the Integrated Cancer Prevention Center between 2006 and 2014 were enrolled. This population was supplemented with 1,611 cancer patients from the same institution. Demographics, medical history, and pathological data were recorded. Mortality data were obtained from the Ministry of Health's registry. The prevalence of APC I1307K in cancer patients and healthy subjects was compared. The APC I1307K variant was detected in 189 (11.8%) cancer patients compared to 614 (4.7%) healthy subjects, reflecting an adjusted age and sex odds ratio (OR) of 2.53 (p < 0.0001). History of two or more cancer types was associated with a positive carrier prevalence (OR = 4.38 p < 0.0001). Males had significantly increased carrier prevalence in lung, urologic, pancreatic, and skin cancers. The carrier prevalence among females was significantly higher only in breast and skin cancers. Female carriers developed cancer at a significantly older age compared to non-carriers (average 62.7 years vs. 57.8, respectively, p = 0.027), had better survival rates (HR = 0.58, p = 0.022) and overall increased longevity (average age of death 78.8 vs. 70.4 years, respectively, p = 0.003). In conclusion, the APC I1307K variant is a reliable marker for overall cancer risk (OR 2.53). Further studies are needed to evaluate its use for specific cancer types-particularly in males. Female carriers have better prognosis and increased lifespan.

Delayed Wound Healing in Heat Stable Antigen (HSA/CD24)-Deficient Mice

Background

Healthy individuals rarely have problems with wound healing. Most skin lesions heal rapidly and efficiently within one to two weeks. However, many medical and surgical complications can be attributed to deficiencies in wound repair. Open wounds have lost the barrier that protects tissues from bacterial invasion and allows the escape of vital fluids. Without expeditious healing, infections become more frequent. The CD24 gene encodes a heavily-glycosylated cell surface protein anchored to the membrane by phosphatidylinositol. CD24 plays an important role in the adaptive immune response and controls an important genetic checkpoint for homeostasis and autoimmune diseases in both mice and humans. We have previously shown that overexpression of CD24 results in increased proliferation and migration rates.

Aim

To examine the role of CD24 in the wound healing process.

Methods

An excisional model of wound healing was used and delayed wound healing was studied in genetically modified heat stable antigen (HSA/CD24)-deficient mice (HSA^-/-) compared to wild-type (WT) mice.

Results

Large full-thickness skin wounds, excised on the back of mice, exhibited a significant delay in the formation of granulation tissue, and in wound closure when compared to their WTHSA^+/+ littermates. Wounds were histologically analyzed and scored, based on the degree of cellular invasion, granulation tissue formation, vascularity, and re-epithelialization. Additionally, in stitched wounds, the HSA^-/- mice failed to maintain their stitches; they did not hold and fell already 24 hours, revealing erythematous wound fields. Re-expression of HSA, delivered by lentivirus, restored the normal healing phenotype, within 24 hours post-injury, and even improved the healing in WT, and in BalbC mice.

Conclusions

Delayed wound-healing in the absence of HSA/CD24 suggests that CD24 plays an important role in this process. Increased expression of CD24, even in the normal state, may be used to enhance wound repair.

Abstract 3532: Selective eradication of colorectal cancer cells by adenovirus-based delivery of toxins

Background: K-Ras gene mutation is an early event in the development of colorectal cancer (CRC) and occurs in ∼50% of CRC cases. We propose a strategy that exploits the Ras hyperactive pathway, rather than inhibiting it. We have previously shown that recombinant adenovirus, carrying a pro-apoptotic gene under the regulation of Ras-responsive elements (RREs; Ets/AP1), suppressed the growth of tumor cells displaying hyperactive K-Ras (Naumov, 2012; Lisiansky, 2012). Toxin-antitoxin (TA) systems are evolutionarily successful entities, prevalent in lower organisms that play important roles in a diverse range of cellular activities

Aim: To establish an improved tightly regulated RRE-cassette based on the bacterial MazEF TA system.

Methods: Efficient vectors for targeted gene delivery were constructed and cloned into a “1st generation” ΔE1/ΔE3 human type-5 adenoviral vector. Virus particles were produced their titer was calculated, by the end-point dilution assay, and tested for their potency. Cell death was measured qualitatively by fluorescent microscopy and colony formation assay, and quantified by MTT. Apoptosis was determined by FACS using annexin V and RedDot2 dyes. In vivo tumor formation was examined in xenografts. Ad-Py4-SV40-MazEF and Ad-ΔPY4-CMV-MazEF viruses (1×109pfu) or PBS were administrated i.p. twice with a 3-day interval between injections.

Results: Adenovirus treatment induced massive cell death, in a dose-dependent manner; 73% in K-Ras-mutated compared to 22% in WT K-Ras tumor cells, at 10 MOI. The cytotoxic effect was confirmed qualitatively by colony formation assay. In the absence of RRE, MazE anti-toxin expression was increased, protecting normal cells from any possible system leakage and confirming the selectivity, specificity, and safety of the targeting system. FACS analysis showed massive cell death, 55% apoptosis and 82% dead cells, following infection with the full TA-encoding viruses. In control RRE-lacking viruses a modest toxicity was seen (18% and 10%, respectively). Impressive tumor shrinkage was demonstrated in vivo following treatment with Ad-Py4-SV40-MazEF-encoding adenovirus (61%) without any toxic side effects. The tumor volume in the Ad-ΔPY4-SV40-MazEF-treated mice (control group) was reduced only by 27% (p&lt;0.05). No growth inhibition was seen following injection of PBS.

Conclusions: A proof-of-concept for a novel cancer gene therapy by exploiting aberrant K-Ras hyperactive pathway was successfully demonstrated. The lack of toxicity holds promise for effective and safe therapy of human cancers carrying K-Ras mutations.

Note: This abstract was not presented at the meeting.

Citation Format: Shiran Shapira, Assaf Shapira, Dina Kazanov, Ilana Nabiochtchikov, Nadir Arber, Sarah R. Kraus. Selective eradication of colorectal cancer cells by adenovirus-based delivery of toxins. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3532. doi:10.1158/1538-7445.AM2015-3532

Protective effects of rosuvastatin in a rat model of lung contusion: Stimulation of the cyclooxygenase 2-prostaglandin E-2 pathway

BACKGROUND

Lung contusion, which can occur in patients with blunt thoracic trauma, is a leading risk factor for development of acute lung injury (ALI) and acute respiratory distress syndrome. Statins are lipid-lowering drugs with many beneficial antiinflammatory and antioxidative effects. We therefore hypothesized that the administration of statins immediately after trauma will inhibit the production of inflammatory mediators, and thereby alleviate the severity of lung injury.

METHODS

A model of blunt chest injury in rat was employed. The effects of statins (rosuvastatin) and cyclooxygenase-2 (COX-2) inhibitors (meloxicam) on ALI were assessed by measuring inflammatory mediator levels in the serum and in the bronchoalveolar space. Animals were killed at the end of day 3. Histologic evaluation of lung tissue was performed to confirm the presence and severity of lung contusion as well as the effects of statins, nonsteroidal antiinflammatory drugs, and their combination.

RESULTS

Administration of meloxicam after lung contusion decreased the amount of neutrophil infiltration; however, marked hemorrhage and edema were still noticed. Administration of rosuvastatin decreased significantly cytokine levels that were increased after the blunt chest trauma. Rosuvastatin increased the expression of inducible nitric oxide (iNOS), COX-2, heme oxygenase-1 (HO-1), and prostaglandin E2 (PGE-2) in the bronchoalveolar lavage fluid of the rat contused lungs. Coadministration of meloxicam prevented these changes.

CONCLUSION

Rosuvastatin treatment after lung contusion attenuated several features of ALI. The enhanced activity of iNOS, COX-2, and HO-1 in the lung may reflect the advent of protective processes that took place in the contused lung. To our knowledge, this is the first demonstration that prostaglandin pathways play an essential role in the effects of statins in lung injury.

Peptides for diagnosis and treatment of colorectal cancer

Colorectal cancer (CRC) is a major health concern worldwide, as it is the third most frequently diagnosed cancer and the second leading cause of cancer-related death. There are a number of treatment options for CRC, however many of them are disappointing. Therefore, significant efforts are directed towards the development of new biological therapies with improved efficacy. The use of peptides in CRC treatment holds promise as emerging novel anti-cancer agents. Targeted therapy based on the use of peptides that can directly target tumor cells without affecting normal cells is evolving as an alternative strategy to conventional therapies and particularly, chemotherapy. The main advantages of peptides are their relatively easy and rapid synthesis process, and the vast possibilities for chemical modifications that can be exploited for novel peptide design and improved delivery. Peptides can be utilized directly as cytotoxic agents or indirectly as they can act as carriers of cytotoxic agents, drugs, or radioisotopes by specifically targeting tumor cells. They can also be used for diagnostic purposes. Current research focuses on developing peptides that can serve as tumor targeting moieties, permeabilize membranes to induce cytotoxicy, radiolabeled peptides, and peptide vaccines. In addition, improving targeting to tumors, reducing side effects, due to non-specific toxicity, and unraveling the pharmacokinetic characteristics of potential peptides, for either therapeutic or diagnostic use, are also subjects of intensive investigation. This review provides a brief overview on the role of peptides in CRC diagnosis and therapy that are currently being investigated, and their potential applications in the clinical setting.

Aspirin but not meloxicam attenuates early atherosclerosis in apolipoprotein E knockout mice

BACKGROUND

Atherosclerosis is a complex vascular inflammatory disease. In the last decade it was suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) and in particular inhibition of cyclooxygenase (COX)-2 are associated with an increase in cardiovascular morbidity and mortality. Aspirin is known to reduce the incidence and mortality from ischemic heart disease and is a mainstay in the prevention of vascular complications of atherosclerosis.

OBJECTIVES

To examine the effect of meloxicam, a selective COX-2 inhibitor, or low dose aspirin on the development of experimental atherosclerosis in apoE knockout (KO) compared to wild-type (WT) mice. We aimed to test the hypothesis that meloxicam, a potential vasculitis inducer, would exacerbate atherosclerotic lesions while aspirin, which is known to reduce the incidence of thrombosis occlusive events, would increase protection in this model.

METHODS

We randomly divided 36 male apoE KO and 36 WT mice, 8 weeks old. Mice were treated for 10 weeks with 0.1 mg/ml aspirin, or 0.05 mg/ml meloxicam, dissolved in their drinking water. Control groups received regular drinking water. At sacrifice, the hearts were removed for histochemical staining and plaque size and composition were examined.

RESULTS

Aspirin-treated animals displayed a decreased atherosclerotic lesion area compared to the untreated control mice, while meloxicam had a null effect on the extent of atherosclerosis in Apo E KO mice.

CONCLUSIONS

These results suggest that low dose aspirin reduces early atherosclerosis, while inhibition of COX-2 by meloxicam is not associated with an increase in atherosclerotic plaque size in this mouse model.

CD24 knockout prevents colorectal cancer in chemically induced colon carcinogenesis and in APC(Min)/CD24 double knockout transgenic mice

Increased expression of CD24 is seen in a large variety of solid tumors, including up to 90% of gastrointestinal (GI) tumors. Stable derivatives of SW480 colorectal cancer (CRC) cells that overexpress CD24 proliferate faster, and increase cell motility, saturation density, plating efficiency, and growth in soft agar. They also produce larger tumors in nude mice as compared to the parental SW480 cells. Most significantly, even depletion of one copy of the CD24 allele in the APC(Min/+) mice of a transgenic mouse model led to a dramatic reduction in tumor burden in all sections of the small intestine. Homozygous deletion of both CD24 alleles resulted in complete abolishment of tumor formation. Moreover, CD24 knockout mice exhibited resistance to chemically induced inflammation-associated CRC. Finally, a new signal transduction pathway is suggested: namely, CD24 expression downstream to COX2 and PGE2 synthesis, which is directly regulated by β-catenin. CD24 is shown in vitro and in vivo as being an important oncogene in the gut, and one that plays a critical role in the initiation and progression of carcinogenesis.