Cetuximab, an EGFR-blocking antibody, is currently approved for treatment of metastatic head and neck squamous cell carcinoma (HNSCC), but its response rate is limited. In addition to blocking EGFR-stimulated cell signaling, cetuximab can induce endocytosis of ASCT2, a glutamine transporter associated with EGFR in a complex, leading to glutathione biosynthesis inhibition and cellular sensitization to ROS. Pyruvate dehydrogenase kinase-1 (PDK1), a key mitochondrial enzyme overexpressed in cancer cells, redirects glucose metabolism from oxidative phosphorylation toward aerobic glycolysis. In this study, we tested the hypothesis that targeting PDK1 is a rational approach to synergize with cetuximab through ROS overproduction. We found that combination of PDK1 knockdown or inhibition by dichloroacetic acid (DCA) with ASCT2 knockdown or with cetuximab treatment induced ROS overproduction and apoptosis in HNSCC cells, and this effect was independent of effective inhibition of EGFR downstream pathways but could be lessened by N-acetyl cysteine, an anti-oxidative agent. In several cetuximab-resistant HNSCC xenograft models, DCA plus cetuximab induced marked tumor regression, whereas either agent alone failed to induce tumor regression. Our findings call for potentially novel clinical trials of combining cetuximab and DCA in patients with cetuximab-sensitive EGFR-overexpressing tumors and patients with cetuximab-resistant EGFR-overexpressing tumors.
Haiquan Lu, Yang Lu, Yangyiran Xie, Songbo Qiu, Xinqun Li, Zhen Fan
Meningiomas are the most common adult primary tumor of the central nervous system, but there are no known effective medical therapies for recurrent meningioma, particularly for WHO grade II and III tumors. Meningiomas arise from the meninges, located outside the blood-brain barrier, and therefore may be directly targeted by antibody-mediated immunotherapy. We found that PD-L1 was highly expressed in multiple human malignant meningioma cell lines and patient tumor samples. PD-L1 was targeted with the anti-PD-L1 antibody avelumab and directed natural killer cells to mediate antibody-dependent cellular cytotoxicity (ADCC) of PD-L1-expressing meningioma tumors both in vitro and in vivo. ADCC of meningioma cells was significantly increased in target cells that upregulated PD-L1 expression and, conversely, abrogated in tumor cells that were depleted of PD-L1. Additionally, the high-affinity natural killer cell line, haNK, outperformed healthy donor NK cells in meningioma ADCC. Together, these data support a clinical trial designed to target PD-L1 with avelumab and haNK cells, potentially offering a novel immunotherapeutic approach for patients with malignant meningioma.
Amber J. Giles, Shuyu Hao, Michelle R. Padget, Hua Song, Wei Zhang, John Lynes, Victoria E. Sanchez, Yang Liu, Jinkyu Jung, Xiaoyu Cao, Rika Fujii, Randy L. Jensen, David Gillespie, Jeffrey Schlom, Mark R. Gilbert, Edjah K. Nduom, Chunzhang Yang, John H. Lee, Patrick Soon-Shiong, James W. Hodge, Deric M. Park
Aberrant activation of the NF-κB transcription factors underlies chemoresistance in various cancer types including colorectal cancer (CRC). Targeting the activating mechanisms, particularly with inhibitors to the upstream IκB kinase (IKK) complex, is a promising strategy to augment the effect of chemotherapy. However, clinical success has been limited largely due to low specificity and toxicities of tested compounds. In solid cancers, the IKK kinases is driven predominantly by the Toll-like/Interlekin-1 receptor family members, which signal through the Interleukin-1 Receptor-Associated Kinases (IRAKs), with isoform 4 (or IRAK4) being the most critical. The pathogenic role and therapeutic value of IRAK4 in CRC has not been investigated. We found that IRAK4 inhibition significantly abrogates colitis-induced neoplasm in APCMin/+ mice, and bone marrow transplant experiments showed an essential role of IRAK4 in immune cells during neoplastic progression. Chemotherapy significantly enhances IRAK4 and NF-κB activity in CRC cells through upregulating TLR9 expression, which can in turn be suppressed by IRAK4 and IKK inhibitors, suggesting a feedforward pathway that protects CRC cells from chemotherapy. Lastly, increased tumor phospho-IRAK4 staining or IRAK4 mRNA expression are associated with significantly worse survival in CRC patients. Our results support targeting IRAK4 to improve the effects of chemotherapy and outcomes in CRC.
Qiong Li, Yali Chen, Daoxiang Zhang, Julie Grossman, Lin Li, Namrata Khurana, Hongmei Jiang, Patrick Grierson, John Herndon, David G. DeNardo, Grant A. Challen, Jingxia Liu, Marianna B. Ruzinova, Ryan C. Fields, Kian-Huat Lim
Sustained therapeutic responses from traditional and next-generation antiandrogen therapies remain elusive in clinical practice due to inherent and/or acquired resistance resulting in persistent androgen receptor (AR) activity. Antisense oligonucleotides (ASO) have the ability to block target gene expression and associated protein products and provide an alternate treatment strategy for castration-resistant prostate cancer (CRPC). We demonstrate the efficacy and therapeutic potential of this approach with a Generation-2.5 ASO targeting the mouse AR in genetically engineered models of prostate cancer. Furthermore, reciprocal feedback between AR and PI3K/AKT signaling was circumvented using a combination approach of AR-ASO therapy with the potent pan-AKT inhibitor, AZD5363. This treatment strategy effectively improved treatment responses and prolonged survival in a clinically relevant mouse model of advanced CRPC. Thus, our data provide preclinical evidence to support a combination strategy of next-generation ASOs targeting AR in combination with AKT inhibition as a potentially beneficial treatment approach for CRPC.
Marco A. De Velasco, Yurie Kura, Kazuko Sakai, Yuji Hatanaka, Barry R. Davies, Hayley Campbell, Stephanie Klein, Youngsoo Kim, A. Robert MacLeod, Koichi Sugimoto, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura
Broadly neutralizing antibodies (bNAbs) against HIV-1 are under evaluation for both prevention and therapy. HIV-1 sequence diversity observed in most HIV-infected individuals and archived variations in critical bNAb epitopes present a major challenge for the clinical application of bNAbs, as preexistent resistant viral strains can emerge, resulting in bNAb failure to control HIV. In order to identify viral resistance in patients prior to antibody therapy and to guide the selection of effective bNAb combination regimens, we developed what we believe to be a novel Bayesian machine-learning model that uses HIV-1 envelope protein sequences and foremost approximated glycan occupancy information as variables to quantitatively predict the half-maximal inhibitory concentrations (IC50) of 126 neutralizing antibodies against a variety of cross clade viruses. We then applied this model to peripheral blood mononuclear cell–derived proviral Env sequences from 25 HIV-1–infected individuals mapping the landscape of neutralization resistance within each individual’s reservoir and determined the predicted ideal bNAb combination to achieve 100% neutralization at IC50 values <1 μg/ml. Furthermore, predicted cellular viral reservoir neutralization signatures of individuals before an analytical antiretroviral treatment interruption were consistent with the measured neutralization susceptibilities of the respective plasma rebound viruses, validating our model as a potentially novel tool to facilitate the advancement of bNAbs into the clinic.
Wen-Han Yu, David Su, Julia Torabi, Christine M. Fennessey, Andrea Shiakolas, Rebecca Lynch, Tae-Wook Chun, Nicole Doria-Rose, Galit Alter, Michael S. Seaman, Brandon F. Keele, Douglas A. Lauffenburger, Boris Julg
Aberrant accumulation and activation of eosinophils and potentially mast cells (MCs) contribute to the pathogenesis of eosinophilic gastrointestinal diseases (EGIDs), including eosinophilic esophagitis (EoE), gastritis (EG), and gastroenteritis (EGE). Current treatment options such as diet restriction and corticosteroids have limited efficacy and are often inappropriate for chronic use. One promising new approach is to deplete eosinophils and inhibit MCs with a monoclonal antibody (mAb) against Siglec-8, an inhibitory receptor selectively expressed on MCs and eosinophils. Here, we characterize MCs and eosinophils from human EG and EoE biopsies using flow cytometry and evaluate the effects of an anti-Siglec-8 mAb using a novel Siglec-8 transgenic mouse model in which EG/EGE was induced by ovalbumin sensitization and intragastric challenge. Mast cells and eosinophils were significantly increased and activated in human EG and EoE biopsies compared to healthy controls. Similar observations were made in EG/EGE mice. In Siglec-8 transgenic mice, anti-Siglec-8 mAb administration significantly reduced eosinophils and MCs in the stomach, small intestine, and mesenteric lymph nodes, and decreased levels of inflammatory mediators. In summary, these findings suggest a role for both MCs and eosinophils in EGID pathogenesis and support the evaluation of anti-Siglec-8 as a therapeutic approach that targets both eosinophils and MCs.
Bradford A. Youngblood, Emily C. Brock, John Leung, Rustom Falahati, Bruce S. Bochner, Henrik S. Rasmussen, Kathryn Peterson, Christopher Bebbington, Nenad Tomasevic
The synucleinopathies Parkinson’s disease (PD) and Multiple system atrophy (MSA) — characterized by α-synuclein intracytoplasmic inclusions into, respectively, neurons and oligodendrocytes — are associated with impairment of the autophagy-lysosomal pathways (ALP). Increased expression of the master regulator of ALP, transcription factor EB (TFEB), is hypothesized to promote the clearance of WT α-synuclein and survival of dopaminergic neurons. Here, we explore the efficacy of targeted TFEB overexpression either in neurons or oligodendrocytes to reduce the pathological burden of α-synuclein in a PD rat model and a MSA mouse model. While TFEB neuronal expression was sufficient to prevent neurodegeneration in the PD model, we show that only TFEB oligodendroglial overexpression leads to neuroprotective effects in the MSA model. These beneficial effects were associated with a decreased accumulation of α-synuclein into oligodendrocytes through recovery of the ALP machinery. Our study demonstrates that the cell type where α-synuclein aggregates dictates the target of TFEB overexpression in order to be protective, paving the way for adapted therapies.
Marie-Laure Arotcarena, Mathieu Bourdenx, Nathalie Dutheil, Marie-Laure Thiolat, Evelyne Doudnikoff, Sandra Dovero, Andrea Ballabio, Pierre-Olivier Fernagut, Wassilios G. Meissner, Erwan Bezard, Benjamin Dehay
Background: Circadian timing of treatments can largely improve tolerability and efficacy in patients. Thus, drug metabolism and cell cycle are controlled by molecular clocks in each cell, and coordinated by the core body temperature 24-hour rhythm, which is generated by the hypothalamic pacemaker. Individual circadian phase is currently estimated with questionnaire-based chronotype, center-of-rest time, dim light melatonin onset (DLMO), or timing of CBT maximum (acrophase) or minimum (bathyphase). Methods: We aimed at circadian phase determination and read-out during daily routine in volunteers stratified by sex and age. We measured (i) chronotype; (ii) q1min CBT using two electronic pills swallowed 24-hours apart; (iii) DLMO through hourly salivary samples from 18:00 to bedtime; (iv) q1min accelerations and surface temperature at anterior chest level for seven days, using a tele-transmitting sensor. Circadian phases were computed using cosinor and Hidden-Markov modelling. Multivariate regression identified the combination of biomarkers that best predicted core temperature circadian bathyphase. Results: Amongst the 33 participants, individual circadian phases were spread over 5h10min (DLMO), 7h (CBT bathyphase) and 9h10 min (surface temperature acrophase). CBT bathyphase was accurately predicted, i.e. with an error <1h for 78.8% of the subjects, using a new digital health algorithm (INTime), combining time-invariant sex and chronotype score, with computed center-of-rest time and surface temperature bathyphase (adjusted R-squared = 0.637). Conclusion: INTime provided a continuous and reliable circadian phase estimate in real time. This model helps integrate circadian clocks into precision medicine and will enable treatment timing personalisation following further validation.
Sandra Komarzynski, Matei Bolborea, Qi Huang, Bärbel Finkenstädt, Francis Lévi
Type 2 diabetes mellitus (T2DM), also known as adult-onset diabetes, is characterized by ineffective insulin action due to insulin resistance in key metabolic tissues. Insulin receptor (IR) plays an important role in insulin signal transduction, defect of which has been considered the fundamental cause of T2DM. IR content reduction in diabetes is one key contributor to the defective insulin signaling and diabetes progression. Rescuing IR levels by transgenic complementation has not been considered as a treatment option because it is limited by uncontrollable expression level, tissue selectivity, or developmental defects. In the current study, we demonstrated that single-dose adeno-associated virus (AAV) vector delivered expression of human IR (hIR) in the liver of inducible IR-knockout mice and significantly improved the diabetic phenotype caused by IR deletion during adulthood. Such an approach was also applied, for the first time to our knowledge, to treating ob/ob mice, a model of severe T2DM attributed to superfluous calorie intake and insulin resistance. Interestingly, similar treatment with AAV-hIR had no obvious effect in healthy animals, indicative of low hypoglycemic risk as a consequence of potential excessive insulin action. The results described here support restoration of IR expression as a safe and effective T2DM therapeutic with a long-lasting profile.
Yichen Wang, Heather Zhou, Oksana Palyha, James Mu
Aminoglycoside (AG) antibiotics are widely used to prevent life-threatening infections, and cisplatin is used in the treatment of various cancers, but both are ototoxic and result in loss of sensory hair cells from the inner ear. ORC-13661 is a new drug that was derived from PROTO-1, a compound first identified as protective in a large-scale screen utilizing hair cells in the lateral line organs of zebrafish larvae. Here, we demonstrate, in zebrafish larvae and in mouse cochlear cultures, that ORC-13661 provides robust protection of hair cells against both ototoxins, the AGs and cisplatin. ORC-13661 also prevents both hearing loss in a dose-dependent manner in rats treated with amikacin and the loading of neomycin-Texas Red into lateral line hair cells. In addition, patch-clamp recordings in mouse cochlear cultures reveal that ORC-13661 is a high-affinity permeant blocker of the mechanoelectrical transducer (MET) channel in outer hair cells, suggesting that it may reduce the toxicity of AGs by directly competing for entry at the level of the MET channel and of cisplatin by a MET-dependent mechanism. ORC-13661 is therefore a promising and versatile protectant that reversibly blocks the hair cell MET channel and operates across multiple species and toxins.
Siân R. Kitcher, Nerissa K. Kirkwood, Esra D. Camci, Patricia Wu, Robin M. Gibson, Van A. Redila, Julian A. Simon, Edwin W. Rubel, David W. Raible, Guy P. Richardson, Corné J. Kros
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