Need For Novel Therapeutic Options Research Articles

Arnicolide D Inhibits Proliferation and Induces Apoptosis of Osteosarcoma Cells through PI3K/Akt/mTOR Pathway.

Osteosarcoma is considered as the most prevalent form of primary malignant bone cancer, prompting a pressing need for novel therapeutic options. Arnicolide D, a sesquiterpene lactone derived from the traditional Chinese herbal medicine Centipeda minima (known as E Bu Shi Cao in Chinese), showed anticancer efficacy against several kinds of cancers. However, its effect on osteosarcoma remains unclear. This study aimed to investigate the anticancer activity of arnicolide D and the underlying molecular mechanism of its action in osteosarcoma cells, MG63 and U2OS. Cell viability and proliferation were evaluated through MTT assay and colony formation assay following 24 h and 48 h treatment with different concentrations of arnicolide D. Flow cytometry was employed to examine cell cycle progression and apoptosis after 24 h treatment of arnicolide D. Western blotting was performed to determine the expression of the PI3k, Akt and m-TOR and their phosphorylated forms. Our findings revealed that arnicolide D treatment resulted in a significant reduction in cell viability, the inhibition of proliferation, and the induction of apoptosis and cell cycle arrest in the G2/M phase. Furthermore, arnicolide D could inhibit the activation of PI3K/Akt/mTOR pathway in osteosarcoma cells. Based on our results, arnicolide D demonstrated significant anti-osteosarcoma activity and held the potential to be considered as a therapeutic candidate for osteosarcoma in the future.

Non-human primate studies for cardiomyocyte transplantation-ready for translation?

Non-human primates (NHP) are valuable models for late translational pre-clinical studies, often seen as a last step before clinical application. The unique similarity between NHPs and humans is often the subject of ethical concerns. However, it is precisely this analogy in anatomy, physiology, and the immune system that narrows the translational gap to other animal models in the cardiovascular field. Cell and gene therapy approaches are two dominant strategies investigated in the research field of cardiac regeneration. Focusing on the cell therapy approach, several xeno- and allogeneic cell transplantation studies with a translational motivation have been realized in macaque species. This is based on the pressing need for novel therapeutic options for heart failure patients. Stem cell-based remuscularization of the injured heart can be achieved via direct injection of cardiomyocytes (CMs) or patch application. Both CM delivery approaches are in the late preclinical stage, and the first clinical trials have started. However, are we already ready for the clinical area? The present review concentrates on CM transplantation studies conducted in NHPs, discusses the main sources and discoveries, and provides a perspective about human translation.

Repurposing hemostatic drug desmopressin in AVPR2-expressing triple-negative breast cancer: Target expression analysis and preclinical antineoplastic effects on tumor growth and metastatic progression.

e15087 Background: Desmopressin (dDAVP) is a hemostatic drug that acts as an agonist of the arginine vasopressin receptor 2 (AVPR2) that is present in vascular and malignant cells. Preclinical data show that dDAVP triggers cytostatic mechanisms, blocking angiogenesis and reducing metastases by limiting the survival of circulating tumor cells. Triple-negative breast cancer (TNBC) is associated with poor prognosis due to limited response to therapy and frequent early metastatic recurrence. Considering the unsatisfied clinical need for novel therapeutic options in TNBC, we evaluated the antitumoral activity of dDAVP on experimental models of TNBC, alone or in addition to chemotherapy. We also assessed the expression and clinical impact of AVPR2 in breast cancer samples. Methods: Human and murine TNBC cell lines were used for in vitro experiments. Target expression was assessed by qPCR and immunohistochemistry (IHC), in experimental or clinical tumors (NCT01606072). Effects of dDAVP were evaluated by proliferation, clonogenic, 3D growth and chemotaxis assays, qPCR arrays, and confocal microscopy. Local and distant tumor progression were assessed in vivo in nude or BALB/c mice. TIMER2.0 and UCSC Xena platforms (BRCA TCGA /n = 1260) were used for bioinformatic studies. Results: dDAVP significantly reduced growth and chemotaxis of AVPR2-expressing TNBC cells. Cytostatic effects of dDAVP were associated with altered actin cytoskeleton dynamics and differential expression of angiogenesis and metastasis-related genes. Cooperative effects were observed in vitro and in vivo after combining dDAVP with taxane or alkylating therapy. Tumor-bearing mice were treated with intravenous injections of dDAVP (0.3 µg/kg, thrice weekly) in combination with weekly cycles of paclitaxel (10 mg/kg i.p.) or carmustine (25 mg/kg i.p.). Combination regimens resulted in greater survival and tumor growth and metastasis inhibition. Bioinformatic analysis of the TCGA database showed that AVPR2 had a positive prognostic impact on overall survival in breast cancer patients, especially in the basal-like molecular subtype. AVPR2 also correlated with different immune cell infiltrates such as NK and dendritic cells, and CD4+ and CD8+ T cells. Moreover, AVPR2 expression was detected by IHC in 6/18 breast cancer clinical samples using a small cohort of surgical specimens. Conclusions: AVPR2 expression is associated with improved outcomes in patients with TNBC. Agonist activation of AVPR2 using dDAVP leads to cancer cell growth inhibition in TNBC cell lines and mouse models. We propose dDAVP as a potential novel therapeutic option for treating TNBC either as monotherapy or in combination with chemotherapy. The therapeutic impact of its addition to immune checkpoint inhibitors remains to be explored.

Abstract 1359: Rewiring CD8+T cell responses to PD-1 immune checkpoint blockade in PDAC by preventing terminal exhaustion via the inhibitory receptor PSGL-1

Abstract Pancreatic ductal adenocarcinoma (PDAC) is an aggressive, poorly immunogenic cancer with increasing incidence and a poor 5-year survival rate of 12%. PDAC tumors are refractory to all currently available treatments, including immune checkpoint blockade (ICB) therapies, and demonstrate limited infiltration of cytotoxic CD8+ T cells that kill tumor cells. There is therefore an urgent, unmet need for novel therapeutic options. Analysis of single-cell RNA-sequencing data of patient PDAC revealed high expression of the novel immune checkpoint, PSGL-1, on infiltrating CD8+ T cells. We hypothesize that PSGL-1-mediated immune suppression is a critical barrier to effective anti-tumor immunity in PDAC. To test this, we utilized a preclinical model of PDAC where orthotopic injection of the KPC.4662 tumor cell line into pancreata recapitulates patient tumor responses with limited T cell infiltrates and uncontrolled tumor growth in C57BL/6 (wildtype) control mice and compared to PSGL-1KO (C57BL/6 background) mice. At endpoint, tumor burden in PSGL-1KO mice was reduced by >50% compared to controls, with 45% of PSGL-1KO animals exhibiting >70% reduction. Total immune infiltration (CD45+) was 2-fold greater in tumors from PSGL-1KO mice, with a significant increase in infiltrating CD3+ T cells. Detailed analyses revealed that infiltrating CD8+ T cells from PSGL-1KO mice were not only more abundant, but also less differentiated towards terminal exhaustion with sustained TCT-1 expression compared to controls. Moreover, PSGL-1KO mice showed protection against metastatic disease. Since our data support a critical role for T cell driven anti-tumor immunity to PDAC, we transiently depleted CD4+ T cells, CD8+ T cells, or both just prior to tumor cell implantation. While depletion of CD8+ T cells did not impede tumor control by PSGL-1KO mice, depletion of all T cells or only CD4+ T cells resulted in the loss of PDAC tumor growth inhibition, demonstrating a key role of CD4+ cells in the response. Given our previous studies demonstrating an intrinsic role for PSGL-1 in development of terminal T cell exhaustion in melanoma, including loss of TCF-1+ CD8+ T cells, we hypothesized that PSGL-1-deficiency would promote responsiveness to PD-1 ICB, which is ineffective as a monotherapy in PDAC patients and mouse models. To test this prediction, PD-1 ICB was therapeutically administered to control and PSGL-1KO mice. While treatment with anti-PD-1 had no effect on the tumor growth in the control animals, PD-1 ICB resulted in complete tumor ablation in 85% of PSGL-1KO animals, demonstrating a profound synergistic effect of PD-1 inhibition in the absence of PSGL-1. From these studies, we conclude that PSGL-1 is a critical inhibitor of T cell anti-tumor responses in PDAC. PSGL-1 therefore represents a novel ICB target with high translational potential for promoting immune responses to PDAC tumors. Citation Format: Jennifer L. Hope, Yijuan Zhang, Hannah A. Hetrick, Gabriele Romano, Sreeja Roy, Michelle Lin, Ashley B. Palete, Swetha Maganti, Dennis C. Otero, Cosimo Commisso, Linda M. Bradley. Rewiring CD8+T cell responses to PD-1 immune checkpoint blockade in PDAC by preventing terminal exhaustion via the inhibitory receptor PSGL-1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1359.

Structure-based design, and development of amidinyl, amidoximyl and hydroxamic acid based organic molecules as novel antimalarial drug candidates

Malaria remains a significant global health concern causing numerous fatalities and the emergence of antimalarial drug resistance highlights the urgent need for novel therapeutic options with innovative mechanisms of action and targets. This study aimed to design potential inhibitors of Plasmodium falciparum 6-pyruvoyltetrahydropterin synthase (PfPTPS), synthesize them, and experimentally validate their efficacy as antimalarial agents. A structure-based approach was employed to design a series of novel derivatives, including amidinyl, amidoximyl and hydroxamic acid analogs (1c, 1d, 2b, and 3b), with a focus on their ability to bind to the Zn2+ present in the active site of PfPTPS. The syntheses of these compounds were accomplished through various multi-step synthetic pathways and their structural identities were confirmed using 1H and 13C NMR spectra, mass spectra, and elemental analysis. The compounds were screened for their antiplasmodial activity against the NF54 strain of P. falciparum and in vitro cytotoxicity testing was performed using L-6 cells. The in vivo acute toxicity of the compounds was evaluated in mice. Docking studies of the compounds with the 3D structure of PfPTPS revealed their strong binding affinities, with compound 3b exhibiting notable metal–acceptor interaction with the Zn2+ in the protein binding pocket thereby positioning it as a lead compound for PfPTPS inhibition. The in vitro antiplasmodial studies revealed moderate efficacies against the Pf NF54 strain, particularly compounds 1d and 3b which displayed IC50 < 0.2 μM. No significant cytotoxicity was noted on the L-6 rat cell line. Moreover, in vivo studies suggested that compound 3b exhibited both safety and efficacy in treating rodent malaria. The identified lead compound in this study represents a possible candidate for antimalarial drug development and can be further explored in the search for alternative antifolate drugs to combat the malaria menace.

Real-World Progression-Free Survival and Treatment Patterns for t(11;14) Positive Patients with Multiple Myeloma with at Least 2 Prior Lines of Treatment

Background : Multiple myeloma (MM) is a subclonal disease characterized by large heterogeneity with a complex treatment landscape. Patients with MM have a myriad of available treatment options, prescribed based on several factors, including genetic testing, comorbidities, risk status, age, patient preference, and/or prior treatment failures. Cytogenetic abnormalities determines risk stratification and prognosis. The prognostic significance of t(11;14)-positivity has been debated and it is currently considered a standard-risk abnormality; however, testing for t(11;14) may be of potential therapeutic significance. Despite recent advances in treatment that have improved response rates and survival, MM remains incurable. This results in a continuous treat-to-failure approach that eventually leads to a lack of effective therapeutic options. Treatment patterns and outcomes for patients by lines of therapy (LOT) in real-world settings provide important benchmarks for assessments of future targeted therapies. Methods : Data were retrospectively collected from the ConcertAI Patient360 database containing aggregated electronic health record data of patients treated in primarily community-based oncology centers in the US. Adults diagnosed with MM (2011-2022) who received a National Comprehensive Cancer Network-guideline recommended treatment and had ≥2-months follow up were included; this analysis focused on patients with relapsed or refractory (RR) MM who are t(11;14)-positive and received ≥2 prior lines of systemic therapy. Baseline characteristics were determined for the third-line plus (3L+) subgroup of patients with t(11;14) RRMM. Real-world progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Results were stratified by the use of doublet or triplet regimens, in which patients were treated with 2 or 3 classes of treatments among 6 options (ie, proteasome inhibitors [PI], immunomodulatory imide drugs [IMID], anti-CD38 monoclonal antibodies, chemotherapy, BCL-2 inhibitors, exportin-1 inhibitors, or steroid therapy), respectively, at any time during the LOT. Results : Eighty-four patients with t(11;14) RRMM received 3L+ of therapy. Of patients, 43% were female, 20% were Black, and 75% were White. The median (range) age at diagnosis was 64 (37-84), and the median (range) follow-up since diagnosis was 76 (10-209) months. At 24 months since the initiation of treatment, the median (range) PFS for all t(11;14)-positive patients that received 3L+ of therapy was 7.5 (5.9-9.4) months, and the median (range) PFS rate was 14.8% (9.7%-22.5%) (Figure); the median (range) OS for all t(11;14)-positive patients that received 3L+ of therapy was 32.1 (25.4-48.0) months, and the median (range) OS rate was 58.3% (51.0%-66.6%). The most common treatment regimens used in 3L+ included Daratumumab + Pomalidomide ± Dexamethasone (12%), Venetoclax monotherapy (9%), Pomalidomide ± Dexamethasone (7%), and Bortezomib ± Dexamethasone (7%). Of doublet regimens used in 3L+ (n = 69 LOT), 18 (26%) were IMID + steroid, 14 (20%) were PI + steroid, and 11 (16%) monoclonal antibody (MA)+ steroid. For triplet regimens used at 3L+ (n = 97 LOT), 28 (29%) were IMID + MA + steroid, 23 (24%) were IMID + PI + steroid, and 12 (12%) were MA + PI + steroid. Triplet regimen use increased from 52% in 3L to 61% in 4L and was associated with slightly longer PFS in 3L, relative to doublet regimen use. For patients that received 3L+ therapies, the median (95% CI) PFS was 6.7 (5.4-11.1) months for patients receiving doublet regimens, and 7.7 (5.9-11.3) months for patients receiving triplet regimens. Conclusions: Triplet regimens were more commonly used than doublet regimens as 3L+ therapy. Triplets were also associated with slightly longer PFS in 3L; however, PFS rates were low and did not translate into longer OS, suggesting an unmet need for novel therapeutic options for patients with t(11;14) RRMM.

Enhanced fungal specificity and in vivo therapeutic efficacy of a C-22-modified FK520 analog against C. neoformans.

Fungal infections cause significant morbidity and mortality globally. The therapeutic armamentarium against these infections is limited, and the development of antifungal drugs has been hindered by the evolutionary conservation between fungi and the human host. With rising resistance to the current antifungal arsenal and an increasing at-risk population, there is an urgent need for the development of new antifungal compounds. The FK520 analogs described in this study display potent antifungal activity as a novel class of antifungals centered on modifying an existing orally active FDA-approved therapy. This research advances the development of much-needed newer antifungal treatment options with novel mechanisms of action.

Targeting Metabolic Syndrome in Hidradenitis Suppurativa by Phytochemicals as a Potential Complementary Therapeutic Strategy.

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by the appearance of painful inflamed nodules, abscesses, and pus-draining sinus tracts in the intertriginous skin of the groins, buttocks, and perianal and axillary regions. Despite its high prevalence of ~0.4-1%, therapeutic options for HS are still limited. Over the past 10 years, it has become clear that HS is a systemic disease, associated with various comorbidities, including metabolic syndrome (MetS) and its sequelae. Accordingly, the life expectancy of HS patients is significantly reduced. MetS, in particular, obesity, can support sustained inflammation and thereby exacerbate skin manifestations and the chronification of HS. However, MetS actually lacks necessary attention in HS therapy, underlining the high medical need for novel therapeutic options. This review directs attention towards the relevance of MetS in HS and evaluates the potential of phytomedical drug candidates to alleviate its components. It starts by describing key facts about HS, the specifics of metabolic alterations in HS patients, and mechanisms by which obesity may exacerbate HS skin alterations. Then, the results from the preclinical studies with phytochemicals on MetS parameters are evaluated and the outcomes of respective randomized controlled clinical trials in healthy people and patients without HS are presented.

The Utility of Human Milk Oligosaccharides against Group B Streptococcus Infections of Reproductive Tissues and Cognate Adverse Pregnancy Outcomes.

Preterm birth affects nearly 10% of all pregnancies in the United States, with 40% of those due, in part, to infections. Streptococcus agalactiae (Group B Streptococcus, GBS) is one of the most common perinatal pathogens responsible for these infections. Current therapeutic techniques aimed to ameliorate invasive GBS infections are less than desirable and can result in complications in both the neonate and the mother. To this end, the need for novel therapeutic options is urgent. Human milk oligosaccharides (HMOs), an integral component of human breast milk, have been previously shown to possess antiadhesive and antimicrobial properties. To interrogate these characteristics, we examined HMO-mediated outcomes in both in vivo and ex vivo models of GBS infection utilizing a murine model of ascending GBS infection, an EpiVaginal human organoid tissue model, and ex vivo human gestational membranes. Supplementation of HMOs resulted in diminished adverse pregnancy outcomes, decreased GBS adherence to gestational tissues, decreased colonization within the reproductive tract, and reduced proinflammatory immune responses to GBS infection. Taken together, these results highlight the potential of HMOs as promising therapeutic interventions in perinatal health.

Physician Perceptions of the Clinical, Economic and Humanistic Burden of Disease and Unmet Needs in Myelofibrosis: Preliminary Findings from the MPN Landmark Survey in Indonesia.

A cross-sectional survey was designed and administered between November and December 2021 among practicing Haematologists-Medical Oncologists who are experienced in treating patients with MF. The objectives of the survey were to assess physician's understanding of the overall diagnosis of MF, the disease burden, current treatment practices and remaining unmet needs. Outcomes were analysed descriptively. The survey was completed by 30 respondents. The findings suggest that symptom burden is high and has a significant negative impact on quality-of-life. Treatment burden is also high which can result in high healthcare resource utilisation. Physicians expressed need for novel therapeutic options and improved access and coverage for such options. There is also a need to improve access and coverage for JAK V617F testing locally and local hospital infrastructures should be upgraded to ensure MF is accurately diagnosed. Patient may benefit from information on MPN, which may result in earlier presentation, diagnosis and treatment which can improve outcomes. The findings align with previous international research reporting that symptoms and treatment burden are high, and that novel therapeutic options are needed. Additional patient research might be required to better understand the patient experience of MF and how this can be improved.

A randomized trial of olaparib, durvalumab, and cancer vaccine, UV1, as maintenance therapy in patients with BRCAwt with recurrent ovarian cancer: ENGOT-OV56/NSGO-CTU-DOVACC trial.

TPS5615 Background: Most ovarian cancers (OC) are diagnosed at an advanced stage and despite initial therapy, the disease will often relapse and require further treatment Thus, there is a need for novel therapeutic options. PARP inhibitors lead to increasing tumour neoantigen, and modulation of the tumour microenvironment, which may facilitate a more profound antitumour immune response. UV1 is a therapeutic cancer vaccine directed against telomerase. Since telomerase is an essential enzyme and universally expressed by most tumor cells, it represents a unique cancer antigen as a basis for immunotherapy (IO). The rationale for integrating immunotherapy as maintenance therapy following chemotherapy is based on preclinical studies which have shown that chemotherapy induces immunogenic cell death leading to increased recognition of the tumor by the immune system. The proposed study is evaluating the use of the therapeutic cancer vaccine UV1 in combination with olaparib and the PD-L1 inhibitor, durvalumab as maintenance therapy after response to platinum-based chemotherapy. Methods: The primary objective is to demonstrate efficacy of UV1-olaparib-durvalumab combination maintenance therapy against olaparib in maintenance after platinum combination therapy for BRCAwt patients with relapsed ovarian cancer. Key eligibility criteria include: histologically confirmed, platinim sensitive recurrent OC in response to last platinum-containing chemotherapy, BRCAwt. Patients may be previously treated with PARPi, however prior IO is not permitted. Patients are stratified by HRD status and previous use of PARPi. 184 patients are randomized to three arms (1:1:2): arm A: olaparib single agent, arm B: olaparib-durvalumab and arm C: olaparib, durvalumab-UV1. Duration of therapy: olaparib until progression of disease; durvalumab for 24 months; intradermal UV1, 8 doses within 5 months. Intradermal sargramostim is used as vaccine adjuvant. Primary endpoint is progression-free survival (PFS) of arm C versus arm A. Key secondary endpoints include PFS arm B versus C, patient reported outcomes, and overall survival. This NSGO-CTU sponsored trial is enrolling patients in 11 countries. The following cooperative groups are participating: NSGO-CTU (DK, FIN, NOR, SWE, LTU), BGOG (BE), HeGOG (GRC, CYP), NOGGO (DE), AGO-A (AUT) &amp; DGOG (NL). Clinical trial information: NCT04742075 .

Lactiplantibacillus plantarum Lac16 Attenuates Enterohemorrhagic Escherichia coli O157:H7 Infection by Inhibiting Virulence Traits and Improving Intestinal Epithelial Barrier Function.

Large-scale use of antimicrobials in agriculture and medicine contributes to antibiotic residues in raw foods, the spread of antimicrobial resistance (AMR) and drug pollution, which seriously threatens human health and imposes significant economic burdens on society, suggesting the need for novel therapeutic options that prevent or control zoonoses. In this study, four probiotics were selected to assess their capability to alleviate pathogen-induced damage. Results showed that a simulated gastrointestinal juice and bile tolerated L. plantarum Lac16 with high lactic acid secretion can significantly inhibit the growth of multiple zoonotic pathogens. Lac16 also significantly inhibited the biofilm formation and mRNA expression of virulence traits (genes related to virulence, toxins, flagella biogenesis and motility, antibiotic resistance, biofilm formation and AI-2 quorum sensing) of enterohemorrhagic E. coli O157:H7 (EHEC). Furthermore, Lac16 and Lac26 significantly protected C. elegans against zoonotic pathogen-induced (EHEC, S. typhimurium, C. perfringens) deaths. Moreover, Lac16 significantly promoted epithelial repair and ameliorated lipopolysaccharide (LPS)-induced intestinal epithelial apoptosis and barrier dysfunction by activating the Wnt/β-catenin signaling pathway, and markedly reduced LPS-induced inflammatory responses by inhibiting the TLR4/MyD88 signaling pathway. The present results indicate that Lac16 attenuates enterohemorrhagic E. coli infection-induced damage by inhibiting key virulence traits of E. coli, promoting epithelial repair and improving intestinal epithelial barrier function, which may be mediated by the activated Wnt/β-catenin signaling pathway and the inhibited TLR4/MyD88 signaling pathway of the intestinal epithelium.

Metabolic Barriers to Glioblastoma Immunotherapy.

Glioblastoma (GBM) is the most common primary brain tumor with a poor prognosis with the current standard of care treatment. To address the need for novel therapeutic options in GBM, immunotherapies which target cancer cells through stimulating an anti-tumoral immune response have been investigated in GBM. However, immunotherapies in GBM have not met with anywhere near the level of success they have encountered in other cancers. The immunosuppressive tumor microenvironment in GBM is thought to contribute significantly to resistance to immunotherapy. Metabolic alterations employed by cancer cells to promote their own growth and proliferation have been shown to impact the distribution and function of immune cells in the tumor microenvironment. More recently, the diminished function of anti-tumoral effector immune cells and promotion of immunosuppressive populations resulting from metabolic alterations have been investigated as contributory to therapeutic resistance. The GBM tumor cell metabolism of four nutrients (glucose, glutamine, tryptophan, and lipids) has recently been described as contributory to an immunosuppressive tumor microenvironment and immunotherapy resistance. Understanding metabolic mechanisms of resistance to immunotherapy in GBM can provide insight into future directions targeting the anti-tumor immune response in combination with tumor metabolism.

Discovery of lead natural products for developing pan-SARS-CoV-2 therapeutics

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global public health crisis. The reduced efficacy of therapeutic monoclonal antibodies against emerging SARS-CoV-2 variants of concern (VOCs), such as omicron BA.5 subvariants, has underlined the need to explore a novel spectrum of antivirals that are effective against existing and evolving SARS-CoV-2 VOCs. To address the need for novel therapeutic options, we applied cell-based high-content screening to a library of natural products (NPs) obtained from plants, fungi, bacteria, and marine sponges, which represent a considerable diversity of chemical scaffolds. The antiviral effect of 373 NPs was evaluated using the mNeonGreen (mNG) reporter SARS-CoV-2 virus in a lung epithelial cell line (Calu-3). The screening identified 26 NPs with half-maximal effective concentrations (EC50) below 50 μM against mNG-SARS-CoV-2; 16 of these had EC50 values below 10 μM and three NPs (holyrine A, alotaketal C, and bafilomycin D) had EC50 values in the nanomolar range. We demonstrated the pan-SARS-CoV-2 activity of these three lead antivirals against SARS-CoV-2 highly transmissible Omicron subvariants (BA.5, BA.2 and BA.1) and highly pathogenic Delta VOCs in human Calu-3 lung cells. Notably, holyrine A, alotaketal C, and bafilomycin D, are potent nanomolar inhibitors of SARS-CoV-2 Omicron subvariants BA.5 and BA.2. The pan-SARS-CoV-2 activity of alotaketal C [protein kinase C (PKC) activator] and bafilomycin D (V-ATPase inhibitor) suggest that these two NPs are acting as host-directed antivirals (HDAs). Future research should explore whether PKC regulation impacts human susceptibility to and the severity of SARS-CoV-2 infection, and it should confirm the important role of human V-ATPase in the VOC lifecycle. Interestingly, we observed a synergistic action of bafilomycin D and N-0385 (a highly potent inhibitor of human TMPRSS2 protease) against Omicron subvariant BA.2 in human Calu-3 lung cells, which suggests that these two highly potent HDAs are targeting two different mechanisms of SARS-CoV-2 entry. Overall, our study provides insight into the potential of NPs with highly diverse chemical structures as valuable inspirational starting points for developing pan-SARS-CoV-2 therapeutics and for unravelling potential host factors and pathways regulating SARS-CoV-2 VOC infection including emerging omicron BA.5 subvariants.

CHD4 Loss Alters Chromatin Accessibility Giving Rise to Sensitivity to DNA Damage Repair Compounds in Acute Myeloid Leukaemia

Background: Acute Myeloid Leukaemia (AML) is a heterogeneous group of blood and bone marrow disorders arising from myeloid precursors. Responses to current therapeutic options remain sub-optimal for many individuals, highlighting the need for novel therapeutic options; alongside stratifying patients by (epi)genetic alterations. Chromatin remodelling complexes (e.g. nucleosome remodelling and deacetylation complex (NuRD)), that control chromatin organization and gene expression, have emerged as key players in cancer. Cancer genome studies highlighted that modifications in NuRD occur in > 20% of cancers. NuRD regulates chromatin accessibility; CHD4, a core subunit, has a multitude of functions including epigenetic regulation, DNA Damage Repair (DDR), replication and cell cycle progression. Aims: To explore the molecular and epigenetic functions of CHD4 in AML using CRISPR-Cas9 isogenic knockout models (CHD4-/-), particularly the role of CHD4 on AML development and progression and evaluate if there is targetable therapeutic potential. Methods: TGCA datasets were assessed to identify impact of CHD4 expression on AML patient prognosis. Isogenic CHD4-/- models were generated using CRISPR-Cas9 in two AML cell lines (OCI AML 2 and OCI AML 3). Knockout models underwent functional phenotyping studies before inducing DNA damage at clinically relevant doses. Epigenetic mechanisms of CHD4 were assessed using multi-omic approaches including ATAC sequencing, RNA sequencing and proteomic analysis. A DNA Damage/Repair Compound Library (Selleckchem) was screened on CHD4-/- and CHD4 WT models using CellTox™ Green to identify DNA damage compounds that showed significant sensitivity in CHD-/- models and validation was assessed using CellTiter® Glo viability assay and co-culture assays. Combination indices (CI) were calculated using CompuSyn software. Results: Analysis of TCGA AML transcriptomic data (N=173), found that AML patients with intermediate risk cytogenetics and low CHD4 expression had a poorer 5-year survival compared to similar risk group patients with higher CHD4 levels (P=0.032). This indicates that lower CHD4 levels may result in a link between altered cellular transcription and patient survival causing a more aggressive disease phenotype in these patients. Phenotypical analysis of CHD4-/- models showed increased 53BP1 (P= 0.026) and PARP indicating DDR defect characterised by unrepaired dsDNA breaks. Defective DDR was shown by reduced proliferation with cell cycle analysis showing inter-S phase defect with accumulation in G1 and reduction in cells entering S and G2/M phases in the CHD4-/- models. With this profile being further exacerbated under cell exposure to clinically relevant irradiation induced stress. Chromatin accessibility was assessed via ATAC sequencing and showed enhanced open chromatin at areas impacting immune regulation within CHD4-/- cells. RNA and proteomic analysis both showed upregulation of genes involved in immune activation (P=6.96e-8) and cellular senescence (P=5.6e-5) pathways suggesting an altered immune profile in CHD4-/- cells with a potential to exploit this therapeutically. To identify potential therapeutic vulnerabilities in CHD4-/- cells we performed high throughput screening using a 160 compound DNA damaging library which showed an increased sensitivity of CHD4-/- cells to compounds targeting DNA/RNA synthesis pathways, including Mitomycin C, this indicated that loss of CHD4 results in hyper-increase in damage. Further investigation with Mitomycin C found that when in combination with Cytarabine yielded enhanced synergistic effects in CHD4-/- cells (CI 0.001-0.37) when compared to CHD4 WT (CI 0.002-3.1). There was also significantly less viable cells (P=0.016) 24-hours post combination treatment in CHD4-/- compared to WT (33% vs 56%), indicating that CHD4 loss is furthering the damage caused by improper cell cycle leading to cell death. Conclusion A cohort of AML patients with intermediate risk cytogenetics along with lower CHD4 levels have poorer 5-year survival. Lack of CHD4 is shown to cause epigenetic restructuring, gene abnormalities and defective DDR. We have identified Mitomycin C as a therapeutic potential in combination with Cytarabine in CHD4-/- models. Further investigation of this in combination and the mechanism of action could lead to improved outcome for this sub-group of patients.

Sickle Cell Disease (SCD) Burden on Patients Treated With Hydroxyurea (HU): Results from the Real-World Assessment Survey for SCD in Saudi (ROARS)

The prevalence of SCD in the Kingdom of Saudi Arabia (KSA) is one of the highest in the world with up to 2.6% of the population affected. The Real-World Assessment Survey for Sickle Cell Disease in Saudi (ROARS) was conducted to evaluate the impact of SCD on the quality of life (QoL) of this population. Here, we present data on the QoL burden experienced by patients with SCD in KSA treated with hydroxyurea (HU). Between September and December 2021, patients in KSA with SCD (age: 5-65 years) were surveyed (caregivers were surveyed for patients 5-14 years) using structured, bilingual ROARS questionnaires (English/Arabic) through personal quantitative web-assisted telephone interviews. The survey includes the Patient-Reported Outcomes Measurement Information System (PROMIS) global health domain, a validated tool for assessing QoL among SCD patients and caregivers. The survey evaluated topics such as the impact of SCD on QoL, symptoms, impact of SCD on productivity at work/school, and treatment goals. A total of 1011 responses to the survey were collected; of these, 32.3% (n=327) of patients were currently being treated with HU (47% of adult and 17% of pediatric patients surveyed) and are the focus of this analysis. Amongst these patients, the median age (range) was 25 (5-83) years. Patients were responsible for reporting their SCD genotype: 58% of respondents were diagnosed with HbSS (n=189), 26% with HbSC (n=86), 2% with HbSβ0 thalassemia (n=8), and 5% with HbSβ+ thalassemia (n=15). Overall, 35% (adults, n=84; pediatric n=25) of patients in the eastern province were treated with HU, 27% (adult, n=71; pediatric, n=17) in the western province, 24% (adult, n=55; pediatric, n=24) in the southern province, and 14% (adult, n=29; pediatric, n=22) in the central province. Among HU-treated patients, 64% reported never ceasing/stopping treatment, 21% rarely ceased/stopped treatment and 15% of patients cease/stop treatment sometimes, often, or all the time. The most common reason for patients ceasing/stopping treatment was forgetting to take their medication (79%). Of patients who cease/stop treatment sometimes, often, or all the time (n=48), 17% of these stated that their medication was not available while 4% could not afford their medication. The mean (SD) number of VOCs reported by HU-treated patients in the 12 months prior to survey completion was 4.6 (4.09), while 32% (n=104) of these patients reported experiencing ≥5 VOCs in the same period. The most common SCD symptoms (other than VOCs) experienced by HU-treated patients were bone ache (reported by 92% of respondents), fatigue/tiredness (85%), headache (79%), anxiety (61%), joint stiffness (56%) and numbness/tingling (51%). Most HU-treated patients reported poor/fair or good health for all QoL metrics assessed (Figure 1). Almost half of patients (49%) reported that their SCD was impactful/extremely impactful on their emotional wellbeing. Of those treated with HU, 71% of patients reported that HU is effective in treating their SCD symptoms. However, 84% of patients report a desire for alternatives to their current pain management medication while 72% report concerns about the long-term side effects of HU. The most important treatment goals for these patients were improvement in quality of life (82%), improvement in overall symptoms (79%), and reduction in the number of severe pain crises and increase in the number of days free from severe pain crises (79%). A total of 48% of HU-treated patients were bothered by limitations in performing everyday activities; 48% and 55% of patients also reported that their SCD has prevented them from progressing in their career or education, respectively. Patients treated with HU reported missing a mean (SD) of 6.9 (10.4) hours of work in the 7 days prior to survey completion because of their SCD. Access to HU treatment continues to be a challenge, with approximately 70% of patients surveyed not receiving HU. Despite the observed clinical benefit in symptom control, patients receiving HU continue to experience disease burden including substantial impact on QoL and productivity at work/school (as evident from the treatment goals identified by patients). These data highlight the necessity of optimizing HU accessibility and treatment strategies to improve patient outcomes. These data also illustrate the need for novel therapeutic options and management strategies for patients with SCD to target patient-reported treatment goals. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Nor 3'-Demethoxyisoguaiacin from Larrea tridentata Is a Potential Alternative against Multidrug-Resistant Bacteria Associated with Bovine Mastitis.

Bovine mastitis is one of the most common diseases in dairy cows, and it causes significant economic losses in dairy industries worldwide. Gram-positive and Gram-negative bacteria can cause bovine mastitis, and many of them have developed antimicrobial resistance. There is an urgent need for novel therapeutic options to treat the disease. Larrea tridentata-derived compounds represent an important potential alternative treatment. The aim of the present study was to isolate and characterize antibacterial compounds from Larrea tridentata against multidrug-resistant bacteria associated with bovine mastitis. The L. tridentata hydroalcoholic extract (LTHE) exhibited antibacterial activity. The extract was subjected to a bipartition, giving an aqueous fraction (moderate antibacterial activity) and an organic fraction (higher antibacterial activity). Chromatographic separation of the organic fraction enabled us to obtain four active sub-fractions. Chemical analyses through HPLC techniques were conducted for the LTHE, fractions, and sub-fraction Ltc1-F3, from which we isolated two compounds, characterized by 1H and 13C NMR analyses. Compound nor-3 demethoxyisoguaiacin exhibited the best antibacterial activity against the evaluated bacteria (MIC: 0.01–3.12 mg/mL; MBC: 0.02–3.12 mg/mL). The results indicated that nor-3 demethoxyisoguaiacin can be used as an alternative treatment for multidrug-resistant bacteria associated with mastitis.

Zafirlukast Induces VHL- and HIF-2α-Dependent Oxidative Cell Death in 786-O Clear Cell Renal Carcinoma Cells.

Mutations in the Von Hippel–Lindau (VHL) gene are the driving force in many forms of clear cell renal cell carcinoma (ccRCC) and promote hypoxia-inducible factor (HIF)-dependent tumor proliferation, metastasis and angiogenesis. Despite the progress that has already been made, ccRCC generally remain resistant to conventional therapies and ccRCC patients suffer from metastasis and acquired resistance, highlighting the need for novel therapeutic options. Cysteinyl leukotriene receptor 1 (CysLTR1) antagonists, like zafirlukast, are administered in bronchial asthma to control eicosanoid signaling. Intriguingly, long-term use of zafirlukast decreases cancer risk and leukotriene receptor antagonists inhibit tumor growth, but the mechanisms still remain unexplored. Therefore, we aim to understand the mechanisms of zafirlukast-mediated cell death in ccRCC cells. We show that zafirlukast induces VHL-dependent and TNFα-independent non-apoptotic and non-necroptotic cell death in ccRCC cells. Cell death triggered by zafirlukast could be rescued with antioxidants and the PARP-1 inhibitor Olaparib, and additionally relies on HIF-2α. Finally, MG-132-mediated proteasome inhibition sensitized VHL wild-type cells to zafirlukast-induced cell death and inhibition of HIF-2α rescued zafirlukast- and MG-132-triggered cell death. Together, these results highlight the importance of VHL, HIF and proteasomal degradation in zafirlukast-induced oxidative cell death with potentially novel therapeutic implications for ccRCC.

Targeting the PSGL-1 Immune Checkpoint Promotes Immunity to PD-1-Resistant Melanoma.

Immune-checkpoint inhibitors have had impressive efficacy in some patients with cancer, reinvigorating long-term durable immune responses against tumors. Despite the clinical success of these therapies, most patients with cancer continue to be unresponsive to these treatments, highlighting the need for novel therapeutic options. Although P-selectin glycoprotein ligand-1 (PSGL-1) has been shown to inhibit immune responses in a variety of disease models, previous work has yet to address whether PSGL-1 can be targeted therapeutically to promote antitumor immunity. Using an aggressive melanoma tumor model, we targeted PSGL-1 in tumor-bearing mice and found increased effector CD4+ and CD8+ T-cell responses and decreased regulatory T cells (Treg) in tumors. T cells exhibited increased effector function, activation, and proliferation, which delayed tumor growth in mice after anti-PSGL-1 treatment. Targeting PD-1 in PSGL-1-deficient, tumor-bearing mice led to an increased frequency of mice with complete tumor eradication. Targeting both PSGL-1 and PD-1 in wild-type tumor-bearing mice also showed enhanced antitumor immunity and slowed melanoma tumor growth. Our findings showed that therapeutically targeting the PSGL-1 immune checkpoint can reinvigorate antitumor immunity and suggest that targeting PSGL-1 may represent a new therapeutic strategy for cancer treatment.

Targeting the Ghrelin Receptor as a Novel Therapeutic Option for Epilepsy.

Epilepsy is a neurological disease affecting more than 50 million individuals worldwide. Notwithstanding the availability of a broad array of antiseizure drugs (ASDs), 30% of patients suffer from pharmacoresistant epilepsy. This highlights the urgent need for novel therapeutic options, preferably with an emphasis on new targets, since “me too” drugs have been shown to be of no avail. One of the appealing novel targets for ASDs is the ghrelin receptor (ghrelin-R). In epilepsy patients, alterations in the plasma levels of its endogenous ligand, ghrelin, have been described, and various ghrelin-R ligands are anticonvulsant in preclinical seizure and epilepsy models. Up until now, the exact mechanism-of-action of ghrelin-R-mediated anticonvulsant effects has remained poorly understood and is further complicated by multiple downstream signaling pathways and the heteromerization properties of the receptor. This review compiles current knowledge, and discusses the potential mechanisms-of-action of the anticonvulsant effects mediated by the ghrelin-R.