Oglethorpe University

ABSTRACTCentipedes locomote through complex obstacle‐rich environments by propagating waves of body bending and limb stepping. However, little is known about how collisions with obstacles influence locomotion. In terrestrial environments such as branches or leaf litter, obstacles can both cause drag and offer affordances for the animals to generate thrust. In laboratory experiments, we challenged Scolopendra polymorpha (∼9 cm long, ∼1 cm wide) to negotiate model heterogeneous terrains, hexagonal and square lattices composed of thin posts. The centipedes maintained rapid motion (∼0.2 body lengths per cycle, comparable to flat ground speed) across lattices of different spacings by altering their body and limb postures in response to collisions. Several behaviors minimized deleterious limb and head collisions: the first was “prolonged limb adduction,” in which consecutive limbs fold to the body after a leading limb collides with a post, while other limbs maintained a stepping pattern. The second, occurring in narrower lattices, was “body twisting,” in which the animal propagated local body twists to locomote on its side using the posts as footholds. In some cases, the animals used a peristaltic‐like gait, previously undocumented for this species. We propose that the principles discovered here can improve morphologies and control schemes for elongate robots tasked with navigating similar terradynamic scenarios.

Abstract Moore swabs have been used extensively for passive sampling in wastewater surveillance, typically yielding presence/absence information for targets of interest. Quantitative analysis of Moore swab data is only possible if target uptake is well characterized, specifically the relationship between quantity of the target in the liquid sample matrix and the quantity of target sorbing to the Moore swab as a function of time. The mechanism of Moore swab absorption remains unclear and is important to understand toward using them more quantitatively. We conducted viral adsorption and desorption experiments using nonpathogenic SARS-CoV-2 surrogates: Φ6, MHV, and BCoV as well as heat-inactivated Zika virus (ZIKV). We fit empirical adsorption data from batch experiments to Langmuir, Freundlich and Redlich-Peterson isotherm models. We observed the adsorption behavior of viral targets onto Moore swabs is best characterized by the Redlich-Peterson isotherm model. Moore swabs retained the highest viral RNA concentrations after exposure durations between 9-12 hours in the presence of target microbes during kinetic viral adsorption experiments. The results inform current and future use of Moore swabs to produce quantitative data during wastewater surveillance, especially in settings where composite sampling remains infeasible.ImportanceThis paper describes the adsorption behavior of viruses and bacteriophages to Moore swabs. Passive sampling via Moore swabs is among the most scalable form of passive wastewater sampling, considered critical to advance wastewater surveillance globally. But key unknowns constrain the utility of Moore swabs and all passive sampling approaches, including the quantitative relationship between targets in wastewater and recovery via Moore swabs. Practical questions such as how long they should be deployed and whether they can be interpreted quantitatively really depend on a characterization of viral target loading behaviors on Moore swab material as a function of time and concentration in the wastewater. Here, we use an approach that is seldom applied to microbial targets to examine adsorption behavior of viruses to Moore swabs, deriving isotherms that describe the relationships between concentration of the viral targets in wastewater and time on attachment to swab material. This is a critical step in advancing the application of Moore swab passive sampling for wastewater surveillance, with potential relevance to other microbial targets of interest.

Abstract Both GLS1 and c-Myc are upregulated in head and neck squamous cell carcinoma (HNSCC) primary tumors and further increased in metastatic tumors. However, the regulation between these two molecules remains largely unknown. GLS1 is a critical enzyme that regulates glutamate, which plays an important role in cancer metabolism that supports cancer growth and survival. Our bioinformatic analysis of the TCGA HNSCC cohort revealed a strong correlation between c-Myc and GLS1 expression. We describe the importance of c-Myc in regulating GLS1 and vice versa. c-Myc protein directly binds to the promoter of the GLS1 gene and upregulates its expression at the transcriptional level. Interestingly, blocking GLS1 signaling in HNSCC cells by lentiviral shRNA knockdown or CB-839 treatment downregulates USP1, one of the best characterized human DUBs, which in turn reduces c-Myc protein stability via the ubiquitin-proteasome pathway. The GLS1-c-Myc axis thus represents a novel positive feedback loop that is critical for driving the aggressiveness of HNSCC. As the treatment of HNSCC remains a major challenge, these novel findings provide the molecular basis for combining GLS1-specific inhibitors with c-Myc-targeted therapy for the treatment of HNSCC patients. Citation Format: Jianqiang Yang, Fanghui Chen, Fan Yang, Yong Teng. A positive feedback loop between GLS1 and c-Myc drives tumor aggressiveness [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 3061.

To identify proteins specific to the proximal ciliary axoneme, we used iTRAQ to compare short (~2 μm) and full-length (~11 μm) axonemes of Chlamydomonas. Known components of the proximal axoneme such as minor dynein heavy chains and LF5 kinase as well as the ciliary tip proteins FAP256 (CEP104) and EB1 were enriched in short axonemes whereas proteins present along the length of the axoneme were of similar abundance in both samples. The iTRAQ analysis revealed that FAP93, a protein of unknown function, and protein phosphatase 2A (PP2A) are enriched in the short axonemes. Consistently, immunoblots show enrichment of FAP93 and PP2A in short axonemes and immunofluorescence confirms the localization of FAP93 and enrichment of PP2A at the proximal axoneme. Ciliary regeneration reveals that FAP93 assembles continuously but more slowly than other axonemal structures and terminates at 1.03 μm in steady-state axonemes. The length of FAP93 assembly correlates with ciliary length, demonstrating ciliary length-dependent assembly of FAP93. Dikaryon rescue experiments show that FAP93 can assemble independently of IFT transport. In addition, FRAP analysis of GFP-tagged FAP93 demonstrates that FAP93 is stably anchored in the axoneme. FAP93 may function as a scaffold for assembly of other specific proteins at the proximal axoneme.

Abstract Background: Neuropsychological factors (NPF) (i.e., fatigue, pain, cognitive dysfunction, depression, stress, and sleep disturbance) are common in head and neck cancer (HNC) and often cluster together. They can impair a patient’s functional status and quality of life and are an obstacle to effective treatment and a full recovery. Metabolism and inflammation may be underlying mechanisms but may work differently across HPV-related and unrelated HNC. We explored the joint interaction of metabolism, inflammation, and NPF via a stratified multiomics network analysis of the pretreatment plasma metabolome, lipidome, and inflammation cytokines across HPV-related and unrelated HNC. Methods: HNC patients completed validated symptom questionnaires (e.g., Multidimensional Fatigue Inventory, Patient Health Questionnaire-8, Perceived Stress Scale, Pittsburg Sleep Quality Index) and donated blood for untargeted (metabolome) and targeted (lipids and cytokines) assays prior to chemoradiotherapy. Metabolites and lipids were measured by liquid-chromatography high resolution mass spectrometry and the cytokines were measured via multiplex assays. A multiomics network analysis algorithm (xMWAS) plotted network graphs for HPV-related and unrelated HNC separately, by estimating pair-wise partial least squares correlations between the metabolites, lipids, cytokines, and NPF variables. To interpret each network, a multilevel community detection algorithm identified highly correlated clusters of variables, representing possible biological relatedness. Metabolic pathway analysis provided functional interpretation of the metabolite-lipid-cytokine-NPF clusters. Results: There were 82 subjects (59 years mean age, 72% male, 81% white, 48% HPV-related) in which, 186 metabolites, 78 lipids, 7 cytokines (C-reactive protein, Tumor necrosis factor-α, interleukin-1β, IL6, IL10, IL1 receptor antagonist, and TNF receptor-1) and 6 NPF were analyzed. We required a minimum correlation of 0.3 and P-value <0.05 to be included in the network. xMWAS modeled 525 correlations in HPV-related HNC compared to 419 correlations in HPV-unrelated. Three clusters were identified for HPV-related HNC: all 6 NPF were contained in a single cluster with 51 metabolites, 10 lipids, but 0 cytokines. Pathway analysis found enriched levels of aminoacyl-tRNA biosynthesis (P<.001), valine, leucine, and isoleucine biosynthesis (P<.001), and glycine, serine and threonine metabolism (P=0.003). Comparatively, five clusters were identified for HPV-unrelated HNC: the 6 NPF were dispersed between two closely linked clusters along with 23 metabolites, 4 lipids, and 4 cytokines (CRP, IL1β, IL10, IL1ra). Enriched pathways included aminoacyl-tRNA biosynthesis (P<.0001), glycine, serine, and threonine metabolism (P<.0001), cysteine and methionine metabolism (P<.0001). Conclusions: In both HPV-related and unrelated HNC, NPF were closely linked via metabolites enriched in amino acid metabolic pathways, suggesting that NPF may have an amino acid metabolic foundation. Cytokines may play a larger role in HPV unrelated HNC. Citation Format: Ronald C. Eldridge, Yufen Lin, Nabil F. Saba, Andrew Miller, Evanthia C. Wommack, Jennifer Felger, Deborah W. Bruner, Canhua Xiao. Metabolic-inflammatory investigation of head and neck cancer patient reported neuropsychological factors via multiomics integration of the plasma metabolome, lipidome, and circulating inflammation cytokines [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Innovating through Basic, Clinical, and Translational Research; 2023 Jul 7-8; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2023;29(18_Suppl):Abstract nr PO-038.

is one of our leading students of the role of religion in American history, politics, and constitutional law. As such, he is one of a handful of people capable of writing Proclaim Liberty Throughout All the Land, a sweeping, synoptic, and (perhaps most importantly) widely accessible account of how, as the subtitle says, "Christianity has advanced freedom and equality for all Americans."

Abstract KRAS and LKB1 are frequently co-mutated in lung adenocarcinoma and characterize a particularly aggressive, metastatic, and treatment-resistant subtype of this disease. We recently published that the outputs of biological rhythm pathways downstream of the AMPK kinase are altered in KRAS/LKB1-mutant tumors. In a live-cell phenotyping screen we used RNAseq to identify the circadian clock genes PER1 and PER2 as uniquely upregulated in partially transformed and invasive KRAS/LKB1-mutant human bronchial epithelial cells. We have analyzed expression of individual circadian clock genes in KRAS-mutant and KRAS/LKB1-mutant patient tumors and found that expression of the PER genes, particularly PER1, is increased in the KRAS/LKB1 subtype of lung adenocarcinoma. At the protein level, PER1 expression is increased in KRAS/LKB1-mutant HBECs as compared to KRAS-mutant cells. Addback of wild-type LKB1 in A549 cells, which are KRAS/LKB1-mutant, results in a decrease in PER1 protein levels, confirming that LKB1 has a role in controlling PER1 levels. Multiple phosphorylation events lead to PER1 nuclear translocation to control its role as a transcriptional repressor in the core clock. In circadian-synced HBECs, PER1 enters the nucleus in KRAS-mutant cells, but remains cytosolic in KRAS/LKB1-mutant cells. In circadian-synced A549 cells, we also observed a lack of nuclear PER1 localization. Addback of wild-type LKB1 restored nuclear localization of PER1, as did expression of kinase-dead LKB1, suggesting that LKB1’s regulation of PER1 localization is kinase-independent. Our current and future experiments aim to determine how clock-controlled gene expression may be altered in KRAS/LKB1-mutant cells, what the functional impact of altered PER1 expression and localization is on growth of KRAS/LKB1-mutant tumors, and whether pharmacological manipulation of LKB1-related signaling pathways can restore nuclear localization of PER1. Citation Format: Rebecca E. Parker, Junghui Koo, Bhakti Dwivedi, Adam I. Marcus, Melissa Gilbert-Ross. Defining the role of PER1 and circadian rhythm dysregulation in KRAS/LKB1-mutant lung adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference: Targeting RAS; 2023 Mar 5-8; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Res 2023;21(5_Suppl):Abstract nr A027.

Abstract Induction of apoptosis is a critical mechanism underlying the durable efficacy of cancer treatment agents. Bax is a major proapoptotic protein whose activation is required for apoptotic cell death. We have recently discovered that small molecule Bax activator CYD-2-11 targets the S184 structural pocket in the c-terminal tail of Bax, directly activates its proapoptotic activity via conformational change and formation of Bax homo-oligomers in mitochondrial membranes. CYD-2-11 has potent anti-tumor activity against lung cancer in various animal models. Here we found that CYD-2-11 in combination with radiation, cisplatin or BH3 mimetic Bcl2 inhibitor venetoclax (ABT-199) synergistically suppressed tumor growth in non-small cell lung cancer (NSCLC) xenograft models. It is known that LKB1 mutations or deficiency are associated with therapeutic resistance to PD-1/PD-L1 checkpoint blockade immunotherapy. To test whether Bax activator CYD-2-11 reverses resistance to immunotherapy in immunologically “cold” genetically engineered LSL-KRASG12D LKB1 fl/fl (KL) mouse model, KL mice were treated with CYD-2-11, PD-L1 antibody or in combination. Results indicate that PD-L1 antibody alone has no significant anti-tumor effect in KL mice. CYD-2-11 alone can reduce tumor burden, but combination of CYD-2-11 with PD-L1 antibody has very strong synergistic effect and produces maximum efficacy in tumor burden reduction and significantly prolongs survival of KL mice. Mechanistically, combined treatment with CYD-2-11 and PD-L1 antibody enhances T cell infiltration in tumor tissues. These findings provide preclinical evidence for pharmacologic combinations of small molecule Bax activator with chemoradiotherapy, Bcl-2 inhibitor or PD-L1 antibody as novel strategies to treat lung cancer more effectively. Citation Format: Abu Syed Md Anisuzzaman, Muhammad Waliul Talukdar, Xingming Deng. Small molecule Bax activator enhances immunotherapy against lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5089.

Abstract MERTK is a transmembrane receptor that belongs to the TAM (TYRO3, AXL, MERTK) family of receptor tyrosine kinases. The role of MERTK in cancer progression and resistance to therapies are reported in many cancer types, including non-small cell lung cancer (NSCLC). In canonical signaling, MERTK is localized at the cell membrane and mediates intracellular signal transduction pathways. Non-canonical signaling of receptor tyrosine kinases (RTKs) has been reported, including signaling which occurs when RTKs translocate to the nucleus. Our group previously reported nuclear localization of MERTK in leukemia cells and we now extend these findings to non-small cell lung cancer. We found exogenous MERTK localized to the nucleus in cells transfected with a plasmid expressing wild-type MERTK. Additionally, endogenous nuclear MERTK was phosphorylated, suggesting that MERTK may have a functional role in the nucleus. MERTK kinase inhibitor MRX-2843 modulates its nuclear translocation. Introducing point mutations to MERTK autophosphorylation sites diminished nuclear translocation in comparison to cells transfected with wild-type MERTK. Our analysis of proteins that may interact with MERTK to regulate nuclear localization and function demonstrated co-immunoprecipitation of nuclear MERTK and STAT1. Current studies are underway to further explore nuclear MERTK functions and how these roles may be modulated upon interaction with STAT1. Citation Format: K.M. Tanim, Deborah DeRyckere, Douglas K. Graham. Phosphorylation of MERTK is required for nuclear localization in non-small cell lung cancer (NSCLC). [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4991.