Positive Loop Research Articles

Aberrant DNA methylation-mediated NF-κB/fatty acid-binding protein 5 (FABP5) feed-forward loop promotes malignancy of colorectal cancer cells

Fatty acid-binding proteins (FABPs) are intracellular lipid-binding proteins that play roles in fatty acid transport and the regulation of gene expression. Dysregulated FABP expression and/or activity have been associated with cancer pathogenesis; in particular, epidermal-type FABP (FABP5) is upregulated in many types of cancer. However, the mechanisms regulating FABP5 expression and its involvement in cancer remain largely unknown. Here, we examined the regulation of FABP5 gene expression in non-metastatic and metastatic human colorectal cancer (CRC) cells. We found that FABP5 expression was upregulated in metastatic compared with non-metastatic CRC cells as well as in human CRC tissues compared with adjacent normal tissue. Analysis of the DNA methylation status of the FABP5 promoter showed that hypomethylation correlated with the malignant potential of the CRC cell lines. Moreover, FABP5 promoter hypomethylation also correlated with the expression pattern of splice variants of the DNA methyltransferase DNMT3B. ChIP assays and luciferase reporter assays demonstrated that the transcription factor nuclear factor-kappa B (NF-κB) was involved in regulating FABP5 expression. FABP5 expression could be upregulated in metastatic CRC cells by sequential promotion of DNA demethylation followed by activation of NF-κB. We also found that upregulated FABP5 in turn controlled NF-κB activity through IL-8 production. Collectively, these findings suggest the existence of a DNA methylation-dependent NF-κB /FABP5 positive feed-forward loop that may lead to constitutive activation of NF-κB signaling pathway and play a crucial role in CRC progression.

Adiponectin affects the migration ability of bone marrow-derived mesenchymal stem cells via the regulation of hypoxia inducible factor 1α

BackgroundBone marrow (BM) is progressively filled with adipocytes during aging process. Thus, BM adipocytes-derived adiponectin (APN) affects the function of bone marrow-derived mesenchymal stem cells (BMSCs). However, little is known about the effect of APN on migration ability of BMSCs cultured under hypoxic conditions, which is similar to the BM microenvironment.ResultsWe found that the population and migration ability of BMSCs from APN KO mice was higher than that of WT mice due to increased stability of hypoxia inducible factor 1α (HIF1α). Stem cell factor (SCF)-activated STAT3 stimulated the induction of HIF1α which further stimulated SCF production, indicating that the SCF/STAT3/HIF1α positive loop was highly activated in the absence of APN. It implies that APN negatively regulated this positive loop by stimulating HIF1α degradation via the inactivation of GSK3β. Furthermore, APN KO BMSCs were highly migratory toward EL-4 lymphoma, and the interaction between CD44 in BMSCs and hyaluronic acid (HA) from EL-4 enhanced the migration of BMSCs. On the other hand, the migrated BMSCs recruited CD8+ T cells into the EL-4 tumor tissue, resulting in the retardation of tumor growth. Additionally, gradually increased APN in BM on the aging process affects migration and related functions of BMSCs, thus aged APN KO mice showed more significant suppression of EL-4 growth than young APN KO mice due to higher migration and recruitment of CD8+ T cells.ConclusionAPN deficiency enhances CD44-mediated migration ability of BMSCs in the hypoxic conditions by the SCF/STAT3/HIF1α positive loop and influences the migration ability of BMSCs for a longer time depending on the aging process.-wn2w_GA2ifVC_AsP9w8ntVideo

MicroR-9c-5p and novel-mir50 co-target Akt to regulate Lasioderma serricorne reproduction.

High fecundity is a common characteristic of insect pests which increases the difficulty of population control. Serine/threonine kinase Akt is an indispensable component of the insulin signaling pathway. Silencing of LsAkt severely hinders reproduction in Lasioderma serricorne, a stored product insect pest. However, the post-transcriptional pathway of LsAkt in L. serricorne remains unknown. This study identified 2 binding sites of miR-9c-5p and novel-mir50 in the coding sequences of LsAkt. The expression profiles of 2 microRNAs (miRNAs) and LsAkt displayed an opposite pattern during the adult stages. Luciferase reporter assay showed that novel-mir50 and miR-9c-5p could downregulate the expression of LsAkt. Overexpression of miR-9c-5p and novel-mir50 by injection of mimics inhibited the expression of LsAkt and reduced oviposition, decreased egg hatchability, and blocked ovarian development. It also decreased the expression of genes involved in ovarian development (LsVg and LsVgR) and the nutritional signaling pathway (LsTOR, LsS6K, and Ls4EBP), and reduced the phosphorylation of Akt. Conversely, injection of miR-9c-5p and novel-mir50 inhibitors induced the expressions of LsAkt, LsVg, LsVgR, LsTOR, LsS6K, and Ls4EBP, enhanced Akt phosphorylation level, and accelerated ovarian development. Injection of bovine insulin downregulated the expression of miR-9c-5p and novel-mir50 and upregulated the LsAkt expression. It also rescued the reproductive development defects associated with miR-9c-5p/novel-mir50 overexpression, forming a positive regulatory loop of insulin signaling. These results indicate that miR-9c-5p/novel-mir50 regulates the female reproduction of L. serricorne by targeting Akt in response to insulin signaling. The data also demonstrate the effects of the insulin/miRNA/Akt regulatory axis in insect reproduction.

MdMPK3 and MdMPK6 fine-tune MdWRKY17-mediated transcriptional activation of the melatonin biosynthesis gene MdASMT7.

Melatonin (N-acetyl-5-methoxytryptamine) is a potent reactive oxygen species (ROS) scavenger that increases the biotic and abiotic stress tolerance in plants. The signaling and regulation pathways of melatonin in plants remain elusive. Here, we report that transgenic apple (Malus domestica) plants overexpressing the transcription factor gene, MdWRKY17, have higher melatonin contents and lower ROS levels than those of control, while the MdWRKY17 RNA interference (RNAi) lines show the reversed phenotype. The binding of MdWRKY17 to N-acetylserotonin O-methyltransferase7 (MdASMT7) directly promotes the MdASMT7 expression in the in vitro and in vivo. MdASMT7is a melatonin synthase that localizes to the plasma membrane. MdASMT7 overexpression rescued the lower melatonin contents of MdWRKY17-RNAi lines, confirming the role of MdWRKY17-MdASMT7 module in melatonin biosynthesis in apple. Furthermore, melatonin treatment activated the mitogen-activated kinases (MPKs) MdMPK3 and MdMPK6, which phosphorylate MdWRKY17 to promote transcriptional activation of MdASMT7. RNAi-mediated silencing of MdMPK3/6 decreases MdASMT7 expression in transgenic apple plants overexpressing MdWRKY17, which further confirms MdMPK3/6 fine-tunes MdWRKY17-mediated MdASMT7 transcription. This also forms a positive loop that melatonin activates MdMPK3/6 and thus accelerates the biosynthesis of itself via triggering MdMPK3/6-MdWRKY17-MdASMT7 pathway. This novel melatonin regulatory pathway not only have dissected the molecular mechanisms of melatonin biosynthesis but also provided an alternative approach for generating transgenic melatonin-rich apples which may benefits to human health.

Induction of filopodia formation by α-Actinin-2 via RelA with a feedforward activation loop promoting overt bone marrow metastasis of gastric cancer

BackgroundBone marrow metastasis (BMM) is underestimated in gastric cancer (GC). GC with BMM frequently complicate critical hematological abnormalities like diffused intravascular coagulation and microangiopathic hemolytic anemia, which constitute a highly aggressive GC (HAGC) subtype. HAGC present a very poor prognosis with peculiar clinical and pathological features when compared with not otherwise specified advanced GC (NAGC). But the molecular mechanisms underlying BMM from GC remain rudimentary.MethodsThe transcriptomic difference between HAGC and NAGC were analyzed. Genes that were specifically upregulated in HAGC were identified, and their effect on cell migration and invasion was studied. The function of ACTN2 gene were confirmed by GC cell lines, bone-metastatic animal model and patients’ tissues. Furthermore, the molecular mechanism of ACTN2 derived-BMM was explored by multiple immunofluorescence staining, western blot, chromatin immunoprecipitation, and luciferase reporter assays.ResultsWe elucidated the key mechanisms of BMM depending on the transcriptomic difference between HAGC and NAGC. Five genes specifically upregulated in HAGC were assessed their effect on cell migration and invasion. The ACTN2 gene encoding protein α-Actinin-2 was detected enhanced the metastatic capability and induced BMM of GC cells in mouse models. Mechanically, α-Actinin-2 was involved in filopodia formation where it promoted the Actin filament cross-linking by replacing α-Actinin-1 to form α-Actinin-2:α-Actinin-4 complexes in GC cells. Moreover, NF-κB subunit RelA and α-Actinin-2 formed heterotrimers in the nuclei of GC cells. As a direct target of RelA:α-Actinin-2 heterotrimers, the ACTN2 gene was a positive auto-regulatory loop for α-Actinin-2 expression.ConclusionsWe demonstrated a link between filopodia, BMM and ACTN2 activation, where a feedforward activation loop between ACTN2 and RelA is established via actin in response to distant metastasis. Given the novel filopodia formation function and the new mechanism of BMM in GC, we propose ACTN2 as a druggable molecular vulnerability that may provide potential therapeutic benefit against BMM of GC.

Comprehensive fault reporting for three-terminal transmission line using adaptive estimation of line parameters

In this study, the post-fault synchronized phasors acquired from the local phasor measurement units (PMUs) are used to provide comprehensive fault reporting in Three terminal transmission line system (TTTL). The reporting data incorporates the classification, section identification, and localization of the fault based on the post-fault measurements of positive, negative, and zero sequence quantities. For accurate reporting, a proposed algorithm computes transmission line parameters, on hourly basis, to account for fluctuations in characteristics caused by temperature influences arising from either the loading factor or the climatic vagaries. Upon fault occurrence, the algorithm firstly determines fault classification and faulty section. Thereafter, localization of symmetrical faults is achieved via the positive sequence quantities to solve the positive sequence fault loop equation while that of asymmetrical faults is obtained through the negative sequence quantities to solve the negative sequence fault loop equation. The fault localization speed of the reporting proposed algorithm is attributed to the fact that synchronized data are obtained after one and half cycles from the fault onset. PSCAD/EMTDC platform is dedicated for time-domain investigations, while the proposed algorithm is carried out in MATLAB. The proposed algorithm was tested against 1537 fault characteristics at different locations along the TTTL, including varying fault resistances, loading conditions, and network configurations, in addition to assessing its sensitivity to changes in the TTTL parameters. These tests confirmed the algorithm’s reliability to be used with confidence in a variety of scenarios as the only 13 tests were observed with an error of estimation greater than 1%.

Targeting Trop2 by Bruceine D suppresses breast cancer metastasis by blocking Trop2/β-catenin positive feedback loop

IntroductionTumor-associated calcium signal transducer 2 (Trop2) has been used as a transport gate for cytotoxic agents into cells in antibody–drug conjugate designs because of its expression in a wide range of solid tumors. However, the specific role of Trop2 itself in breast cancer progression remains unclear and small molecules targeting Trop2 have not yet been reported. ObjectivesTo screen small molecules targeting Trop2, and to reveal its pharmacological effects and the molecular mechanisms of action. MethodsSmall molecule targeting Trop2 was identified by cell membrane chromatography, and validated by cellular thermal shift assay and point mutation analyses. We investigated the pharmacological effects of Trop2 inhibitor using RNA-seq, human foreskin fibroblast (HFF)-derived extracellular matrix (ECM), Matrigel drop invasion assays, colony-forming assay, xenograft tumor model, 4T1 orthotopic metastasis model and 4T1 experimental metastasis model. The molecular mechanism was determined using immunoprecipitation, mass spectrometry, immunofluorescence, immunohistochemistry and Western blotting. ResultsHere we identified Bruceine D (BD) as the inhibitor of Trop2, and demonstrated anti-metastasis effects of BD in breast cancer. Notably, Lys307 and Glu310 residues of Trop2 acted as critical sites for BD binding. Mechanistically, BD suppressed Trop2-induced cancer metastasis by blocking the formation of Trop2/β-catenin positive loop, in which the Trop2/β-catenin complex prevented β-catenin from being degraded via the ubiquitin-proteosome pathway. Destabilized β-catenin caused by BD reduced nucleus translocation, leading to the reduction of transcription of Trop2, the reversal of epithelial-mesenchymal transition (EMT) process, and the inhibition of ECM remodeling, further inhibiting cancer metastasis. Additionally, the inhibitory effects of BD on lung metastatic colonization and the beneficial effects of BD on prolongation of survival were validated in 4T1 experimental metastasis model. ConclusionsThese results support the tumor-promoting role of Trop2 in breast cancer by stabilizing β-catenin in Trop2/β-catenin positive loop, and suggest Bruceine D as a promising candidate for Trop2 inhibition.

On the thixotropy of mature fine tailings

The rheological behavior of mature fine tailings (MFTs) is investigated using transient and steady shear flow fields. The structure breakdown of intact MFT samples is examined by a startup flow experiment at various shear rates. The yield stress of MFTs is estimated by the steady shear stress values at low shear rates. Oscillatory shear (strain amplitude sweep) is also used to verify the obtained yield stress value. MFT samples exhibit thixotropy and a positive hysteresis loop at short shearing time intervals in increasing and decreasing stepwise shear rate tests. The observed hysteresis loops and thixotropy disappear by increasing the shearing time intervals, as the system reaches its equilibrium steady-state structure. The time-dependent rheological behavior of MFTs is quantified by a structural kinetics model through the dimensionless structure parameter, λ. [Toorman, “Modelling the thixotropic behaviour of dense cohesive sediment suspensions,” Rheol. Acta 36, 56–65 (1997).] The kinetic parameters are estimated based on steady-state stresses, elucidating the relative effects of shear rate and Brownian motion on buildup and breakdown of the structure. The flow behavior of MFTs predicted by the structural kinetics model is in agreement with the experimental data.

Modi-1, anti-citrullinated neoepitope vaccine, alone and combined with checkpoint inhibitors in patients with head and neck, breast, renal, and ovarian cancers: ModiFy phase I/II basket clinical trial—Report after completion of monotherapy dose-finding.

2566 Background: Stressful conditions in the tumor microenvironment induce autophagy, resulting in high levels of calcium in autophagosomes, in turn activating peptidylarginine deiminase enzymes; these convert arginine residues within polypeptides to citrulline and alter proteolytic cleavage. MHC-II presents these citrullinated peptides to CD4+ T cells. Modi-1 comprising three citrullinated, adjuvanted peptides targeting vimentin and enolase to inducing and expanding CD4+ T cells. At the tumor site the CD4+ T cells release proinflammatory cytokines including INFγ, further upregulating MHC class II. This enables presentation of endogenous citrullinated peptides on the tumor cells in a positive feed-forward loop. Methods: ModiFY is an open-label, multicohort, multicenter, adaptive Phase I/II basket trial for patients with unresectable Head and Neck Squamous Cell Carcinoma (SCCHN), Triple Negative Breast Cancer (TNBC), Renal Cell Carcinoma and High Grade Serous Ovarian Carcinoma (HGSOC). Patients are treated with Modi-1 alone or - if eligible for standard of care checkpoint inhibitor (CPI) monotherapy - Modi-1 + SoC CPI. The Modi-1 only expansion cohorts will recruit 16 patients per tumor type, Modi-1+CPI will recruit 21 patients per tumor type. Study objectives are safety, the breadth and strength of the cellular immune response, ORR, duration of response, PFS, and OS. Results: As of February 2023, the monotherapy dose-finding has completed. 3 patients received Mod1-1v (vimentin only) 80 µg/peptide and 3 patients received Modi-1 at 400 µg/peptide (vimentin + enolase peptides) as part of the monotherapy dose escalation. No DLTs were observed, triggering enrolment into the monotherapy expansion cohorts. 20 evaluable pts have received Modi-1v (3 pts Modi-1v 80 µg/peptide, 17 Modi-1 400 µg/peptide): 16 had HGSOC, 2 TNBC, 2 SCCHN with 53 doses received; 2 patients have been treated beyond 24 weeks. All patients had skin reactions consistent with a delayed-type hypersensitivity reaction at injection sites. Vaccinations have been well tolerated with 71 adverse reactions in 15 patients reported. All were Grade 1 or 2 except for four Grade 3 reactions in 3 patients (anemia, fatigue, and injection site reactions). There have been no SAEs. Elevation in anti-CCP antibodies has not been seen. In 13 response-evaluable patients, best overall response by RECIST v1.1 included 1 PR (SCCHN), 6 SD and 6 PD. The study is currently enrolling into the combination with checkpoint inhibition dose escalation cohorts and the monotherapy expansion cohorts. Conclusions: Modi-1 is well tolerated, and the early monotherapy efficacy data are encouraging. Safety and early efficacy data are supportive of further development of combination with CPI. Clinical trial information: NCT05329532 .

CCN-Hippo YAP signaling in vision and its role in neuronal, glial and vascular cell function and behavior.

The retina is a highly specialized tissue composed of a network of neurons, glia, and vascular and epithelial cells; all working together to coordinate and transduce visual signals to the brain. The retinal extracellular matrix (ECM) shapes the structural environment in the retina but also supplies resident cells with proper chemical and mechanical signals to regulate cell function and behavior and maintain tissue homeostasis. As such, the ECM affects virtually all aspects of retina development, function and pathology. ECM-derived regulatory cues influence intracellular signaling and cell function. Reversibly, changes in intracellular signaling programs result in alteration of the ECM and downstream ECM-mediated signaling network. Our functional studies in vitro, genetic studies in mice, and multi omics analyses have provided evidence that a subset of ECM proteins referred to as cellular communication network (CCN) affects several aspects of retinal neuronal and vascular development and function. Retinal progenitor, glia and vascular cells are major sources of CCN proteins particularly CCN1 and CCN2. We found that expression of the CCN1 and CCN2 genes is dependent on the activity of YAP, the core component of the hippo-YAP signaling pathway. Central to the Hippo pathway is a conserved cascade of inhibitory kinases that regulate the activity of YAP, the final transducer of this pathway. Reversibly, YAP expression and/or activity is dependent on CCN1 and CCN2 downstream signaling, which creates a positive or negative feedforward loop driving developmental processes (e.g., neurogenesis, gliogenesis, angiogenesis, barriergenesis) and, when dysregulated, disease progression in a range of retinal neurovascular disorders. Here we describe mechanistic hints involving the CCN-Hippo-YAP regulatory axis in retina development and function. This regulatory pathway represents an opportunity for targeted therapies in neurovascular and neurodegenerative diseases. The CCN-YAP regulatory loop in development and pathology.

MiR‑27a‑3p upregulation by p65 facilitates cervical tumorigenesis by increasing TAB3 expression and is involved in the positive feedback loop of NF‑κB signaling.

An altered microRNA (miRNA/miR)‑27a‑3p expression has been identified in cervical cancer, while the exact regulatory mechanisms responsible for the dysregulation of miR‑27a‑3p remain to be fully elucidated. In the present study, a NF‑κB/p65 binding site was identified upstream of the miR‑23a/27a/24‑2 cluster and p65 binding enhanced the transcription of pri‑miR‑23a/27a/24‑2, as well as the expression levels of mature miRNAs, including miR‑27a‑3p in HeLa cells. Mechanistically, using bioinformatics analyses and experimental validation, TGF‑β activated kinase 1 binding protein 3 (TAB3) was identified as a direct target of miR‑27a‑3p. By binding to the 3'UTR of TAB3, miR‑27a‑3p significantly enhanced TAB3 expression. Functionally, it was found that the overexpression of miR‑27a‑3p and TAB3 promoted the malignant potential of cervical cancer cells, as evaluated using cell growth, migration and invasion assays, and specific cell marker determinations in the epithelial mesenchymal transition progression, and vice versa. Further rescue experiments revealed that the enhanced malignant effects induced by miR‑27a‑3p were mediated via its upregulation of TAB3 expression. Moreover, miR‑27a‑3p and TAB3 also activated the NF‑κB signaling pathway and formed a positive feedback regulatory loop composing of p65/miR‑27a‑3p/TAB3/NF‑κB. On the whole, the findings presented herein may provide novel insight into the underlying cervical tumorigenesis and novel biomarker identification for clinical applications.

Identification and Characterization of a New Regulator, TagR, for Environmental Stress Resistance Based on the DNA Methylome of Streptomyces roseosporus.

DNA methylation is a defense that microorganisms use against extreme environmental stress, and improving resistance against environmental stress is essential for industrial actinomycetes. However, research on strain optimization utilizing DNA methylation for breakthroughs is rare. Based on DNA methylome analysis and KEGG pathway assignment in Streptomyces roseosporus, we discovered an environmental stress resistance regulator, TagR. A series of in vivo and in vitro experiments identified TagR as a negative regulator, and it is the first reported regulator of the wall teichoic acid (WTA) ABC transport system. Further study showed that TagR had a positive self-regulatory loop and m4C methylation in the promoter improved its expression. The ΔtagR mutant exhibited better hyperosmotic resistance and higher decanoic acid tolerance than the wild type, which led to a 100% increase in the yield of daptomycin. Moreover, enhancing the expression of the WTA transporter resulted in better osmotic stress resistance in Streptomyces lividans TK24, indicating the potential for wide application of the TagR-WTA transporter regulatory pathway. This research confirmed the feasibility and effectiveness of mining regulators of environmental stress resistance based on the DNA methylome, characterized the mechanism of TagR, and improved the resistance and daptomycin yield of strains. Furthermore, this research provides a new perspective on the optimization of industrial actinomycetes. IMPORTANCE This study established a novel strategy for screening regulators of environmental stress resistance based on the DNA methylome and discovered a new regulator, TagR. The TagR-WTA transporter regulatory pathway improved the resistance and antibiotic yield of strains and has the potential for wide application. Our research provides a new perspective on the optimization and reconstruction of industrial actinomycetes.

Abstract CT256: Modi-1, anti-citrullinated neoepitope vaccine alone and combined with checkpoint inhibitors in patients with head and neck, breast, renal and ovarian carcinoma: protocol for the ModiFY phase I/II basket clinical Ttial

Abstract Stressful conditions in the tumor microenvironment induce autophagy in cancer cells as a mechanism to promote their survival. High levels of calcium within autophagosomes activates peptidylarginine deaminase enzymes which convert arginine residues within polypeptides to citrulline and alters proteolytic cleavage. In the presence of inflammation, the MHC-II pathway presents these new citrullinated peptides to CD4 T cells. Modi-1 vaccine comprising three citrullinated, adjuvanted peptides induces and expands a population of activated CD4 T cells. On reaching the tumor site the CD4 T cells release proinflammatory cytokines including, INFγ, which upregulates MHC class II and the same, but endogenous, modified peptides are presented on the tumor cell surface. This likely causes a positive feed-forward loop with killing of tumor cells. The objective of this study is to evaluate the safety, tolerability, cellular immune and tumor response to 2 citrullinated vimentin and one citrullinated enolase peptide each conjugated to the toll-like receptor 1/2 adjuvant Amplivant® ModiFY is an open-label, prospective, multicohort, multicenter, phase I/II basket trial. Eligible patients have unresectable disease in one of the following tumor types: Squamous Cell Carcinoma of the Head and Neck (SCCHN), Triple Negative Breast Cancer, Renal Cell Carcinoma and High Grade Serous Ovarian Carcinoma. Depending on the status of the disease and eligibility for standard of care (SOC) checkpoint inhibitor (CPI) monotherapy, patients will be treated either with Modi-1 alone or Modi-1 +SOC CPI. A randomized neoadjuvant sub-study in patients with SCCHN scheduled to have tumor resection surgery is included in the protocol. These patients are randomized 1:1 to receive either Modi-1 alone or Modi-1+ pembrolizumab. The primary endpoints are the adverse event rate as measured by CTCAE v5.0 in the initial dose escalation cohorts and the strength of the cellular immune response IFNγ enzyme-linked immune absorbent spot (ELISpot) assay in the dose expansion cohorts. Secondary endpoints (RECIST 1.1 and iRECIST), are objective response rate duration of response, progression-free survival, and overall survival. In the SCCHN neoadjuvant cohort, tumor infiltrating lymphocytes in resected tumor tissue will be profiled using scRNAseq and immunohistochemistry. The study is an adaptive trial, comprising 3+3 dose escalation cohorts followed by a Simon 2-stage design in the dose expansion cohorts. The Modi-1 only dose expansion cohort will recruit 16 patients of each of the target tumor types, whilst the Modi-1+CPI will recruit a total of 21 patients. A total of 21/138 patients have been treated to date. ClinicalTrials.gov NCT05329532 Citation Format: Lindy G. Durrant, Fayaz Masters, Samantha Paston, Robert Miller, David J. Pinato, Rebecca Herbertson, Anne Armstrong, Stefan Symeonides, Christian Ottensmeier. Modi-1, anti-citrullinated neoepitope vaccine alone and combined with checkpoint inhibitors in patients with head and neck, breast, renal and ovarian carcinoma: protocol for the ModiFY phase I/II basket clinical Ttial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT256.

Regener-Eyes® Ophthalmic Solution: A New Therapeutic Agent to Relieve Dryness of the Eye for Tear Hyperosmolarity-Induced Pathological Changes in the Eyes of Patients Suffering From Dry Eye Discomfort

Tear hyperosmolarity is an initial and crucial step in the development, progression and aggravation of dry eye discomfort. Decreased tear secretion or altered tear composition leads to tear film instability/imbalance which in Dry Eye (DE) patients results in abnormally rapid breakup of the tear film after blinking. Numerous structural changes in epithelial cells and mucin-producing goblet cells develop as a consequence of exposition of these cells to the hyperosmolar tears. Tear hyperosmolarity causes oxidative stress, disruption of DNA repair system and induces DNA damage in the cells of ocular surface and lacrimal system, leading to their apoptosis. An injury of lacrimal glands results in decreased tear secretion, enabling the creation of “positive loop” that leads to the DE progression and aggravation. Accordingly, eye drops, which alleviate tear hyperosmolarity and restore tear homeostasis at corneal surface, will break up vicious DEcycle and will relieve eye pain, irritation, discomfort, and vision disturbance in DE patients. Regener-Eyes® Ophthalmic Solution is a hypotonic solution enriched with osmoprotectants (that address the hyperosmolarity of a tear film), which helps support tear stability and contribute to relieve dryness of the eye in DE patients. In this article, we summarized current knowledge and future perspectives about topical administration of Regener-Eyes® Ophthalmic Solution to relieve dryness of the eye in DE patients.

Abstract 2832: Plk1 signaling as a therapeutic target for HPV- head and neck cancer

Abstract Current frontline chemotherapy and radiotherapy for head and neck cancer (HNC) is insufficient as ~60% of patients relapse within two years, indicating a need to identify novel targeted therapies to improve survival outcomes for HNC patients. Human papilloma virus (HPV) incidence is a major cause of head and neck squamous cell carcinoma (HNSCC) in addition to tobacco use. HPV- HNSCC patients are less responsive to frontline treatment than HPV+ HNSCC patients. However, HPV- and HPV+ HNSCC patients are treated similarly. The cell cycle serine-threonine kinase polo-like kinase 1 (Plk1) is known to be overexpressed in HNC. The Cancer Genome Atlas (TCGA) revealed that high expression of Plk1 correlates with worse survival in HNSCC patients (p<0.05). Yet, Plk1 is expressed at similar levels when comparing HPV- and HPV+ HNSCC patients. Therefore, in this study we sought to establish if Plk1 inhibition with onvansertib (currently in Phase I/II clinical trials) alone and in combination with radiation would inhibit HPV- and HPV+ HNSCC growth. We used two HPV+ (UMSCC47, UDSCC2), and two HPV- (HN5, Cal27) human HNSCC cell lines. First, we confirmed that Plk1 inhibition with onvansertib stalls HNSCC cells at the G2/M phase of the cell cycle (n=3). Then, we determined that HNSCC cell viability is reduced in a dose-dependent manner after Plk1 inhibition with onvansertib. Surprisingly, HPV- HNSCC cells exhibited a 2-fold decrease in cell viability as compared to HPV+ HNSCC cells (n=3). These findings were confirmed when assessing 3D spheroid growth of HNSCC cells. Plk1 inhibition with onvansertib (25nM) reduced HPV- HNSCC spheroid growth more than HPV+ (n=2). Combining Plk1 inhibition with radiation also reduced colony formation (n=3, p<0.0001) and increased G2/M stalling (n=3) compared to either single agent in HPV- HNSCC cells. Functionally, onvansertib induces cleaved PARP and pPlk1 expression in HNSCC cells. However, pPlk1 is induced to a higher degree in HPV+ HNSCC cells potentially indicating a positive feedforward loop leading to decreased sensitivity to Plk1 inhibition. In HPV- but not HPV+ HNSCC cells, Plk1 expression is also increased after radiation emphasizing Plk1 as an attractive target to mitigate radioresistance in HPV- HNSCCs (n=3). Our findings that HPV+ HNSCC cells are more resistant to Plk1 inhibition than HPV- HNSCC cells provides novel mechanistic insight into these disease subtypes. As HPV- HNSCC is typically more resistant to standard therapies, these results support a novel combinatorial approach using an already approved Plk1 inhibitor with radiation to improve HPV- HNSCC patient outcomes. Citation Format: Julianna Korns, Samuel Thompson, Trisha Wise-Draper, Vinita Takiar. Plk1 signaling as a therapeutic target for HPV- head and neck 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 2832.

Abstract 2433: SERPINA12 promotes the tumorigenic capacity of hepatocellular carcinoma stem cells through hyperactivation of AKT/β-catenin signaling

Abstract Hepatocellular carcinoma (HCC) is an aggressive disease with a poor clinical outcome. Understanding the mechanisms that drive cancer stemness, which we now know is the root cause of therapy failure and tumor recurrence, is fundamental for designing improved therapeutic strategies. The aim of this study is to identify molecular players specific to CD133+ HCC to better design drugs that can precisely interfere with cancer stem cells (CSCs) but not normal stem cell function. Transcriptome profiling of epithelial-specific ‘normal’ CD133+ cells isolated from fetal and regenerating liver against ‘HCC’ CD133+ cells isolated from proto-oncogene driven and inflammation-associated HCC revealed preferential overexpression of SERPINA12 in HCC but not fetal and regenerating liver cells. SERPINA12 upregulation in HCC is tightly associated with aggressive clinical and stemness features, including survival, tumor stage, cirrhosis, and stemness signatures related to embryonic stem cells, oncogenic dedifferentiation and undifferentiated HCC status. Enrichment of SERPINA12 in HCC is mediated by promoter binding of the well-recognized β-catenin effector TCF7L2 to drive SERPINA12 transcriptional activity. Functional characterization identified a unique and novel role of endogenous SERPINA12 in promoting self-renewal, therapy resistance and metastatic abilities. Mechanistically, SERPINA12 functioned through binding to GRP78, resulting in a hyperactivated AKT/GSK3β/β-catenin signaling cascade, forming a positive feed-forward loop. Intravenous administration of rAVV8-shSERPINA12 sensitized HCC cells to sorafenib and impeded the CSC subset in an immunocompetent HCC mouse model. Collectively, our findings revealed that SERPINA12 is preferentially overexpressed in epithelial HCC CD133+ cells and is a key contributor to HCC initiation and progression by driving an AKT/β-catenin feed-forward loop. Citation Format: Huajian Yu, Lei Zhou, Jane Ho-Chun Loong, Ka-Hei Lam, Tin-Lok Wong, Kai-Yu Ng, Man Tong, Victor WS Ma, Yanyan Wang, Xiang Zhang, Terence K Lee, Jing-Ping Yun, Jun Yu, Stephanie Ma. SERPINA12 promotes the tumorigenic capacity of hepatocellular carcinoma stem cells through hyperactivation of AKT/β-catenin signaling [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 2433.

A 5-μA Low Power Over-Temperature Protection Circuit With High Voltage and Process Stabilities for Line Driver in PLC Applications

This paper introduces a over-temperature protection (OTP) circuit used in line driver chip for PLC applications. For the limitations of the BJT process, the proposed circuit adopts a current distribution structure with a positive loop to realize state switching if the temperature exceeds the threshold or recovers, instead of the traditional structures with integrated comparators in the CMOS process. The method minimizes quiescent current (IQ) and transistor consumptions of the circuit. In addition, due to no comparator exists, there is no need for reference voltage, so that the process and voltage stabilities of the circuit are improved. The OTP circuit is implemented by SOI-BJT process, and relies on a line driver chip for verification. The module consumes 5-μA IQ, which only accounts for 0.02% of the whole chip. The measured maximum temperature drift of the circuit is 0.167 ∘C/V under the power supply voltage range of 6-30V, and the average hysteretic temperature drift of 6 random sampled chips is 0.15 ∘C.

Engineering a modular double-transmembrane synthetic receptor system for customizing cellular programs

Implementation of designer receptors in engineered cells confers them to sense a particular physiological or disease state and respond with user-defined programs. To expand the therapeutic application scope of engineered cells, synthetic receptors realized through different strategies are in great demand. Here, we develop a synthetic receptor system that exerts dual control by incorporating two transmembrane helices for the signal chain. Together with a sensor-actuator device with minimal background signals and a positive loop circuit, this receptor system can sensitively respond to extracellular protein signals. We demonstrate that this synthetic receptor system can be readily adapted to respond to various inputs, such as interleukin-1 (IL-1), programmed death ligand 1 (PD-L1), and HER2, and release customized outputs, including fluorescence signals and the therapeutic molecule IL-2. The robust signaling ability and generality of this receptor system promise it to be a useful tool in the field of cell engineering for fundamental research and translational applications.

Dimethyl fumarate abrogates striatal endoplasmic reticulum stress in experimentally induced late-stage Huntington's disease: Focus on the IRE1α/JNK and PERK/CHOP trajectories.

Introduction: Dimethyl fumarate (DMF) is FDA-approved for use in patients with relapsing multiple sclerosis, and it processes neuroprotection in several experimental settings; however, its impact on combating Huntington's disease (HD) remains elusive. This study aimed to explore the role of DMF post-treatment on HD mediated endoplasmic reticulum (ER) stress response in a selective striatal degeneration HD model. Methods: Rats, exposed to 3-nitropropionic acid, were either left untreated or post-treated with DMF for 14days. Results and Discussion: DMF reduced locomotion deficits in both the open field and beam walk paradigms, boosted the striatal dopamine (DA) content, improved its architecture at the microscopic level, and hindered astrogliosis. Mechanistically, DMF limited the activation of two of the ER stress arms in the striatum by reducing p-IRE1α, p-JNK, and p-PERK protein expressions besides the CHOP/GADD153 content. Downstream from both ER stress arms' suppression, DMF inhibited the intrinsic apoptotic pathway, as shown by the decrease in Bax and active caspase-3 while raising Bcl-2. DMF also decreased oxidative stress markers indicated by a decline in both reactive oxygen species and malondialdehyde while boosting glutathione. Meanwhile, it enhanced p-AKT to activate /phosphorylate mTOR and stimulate the CREB/BDNF/TrkB trajectory, which, in a positive feedforward loop, activates AKT again. DMF also downregulated the expression of miRNA-634, which negatively regulates AKT, to foster survival kinase activation. Conclusion: This study features a focal novel point on the DMF therapeutic ability to reduce HD motor manifestations via its ability to enhance DA and suppress the IRE1α/JNK and PERK/CHOP/GADD153 hubs to inhibit the mitochondrial apoptotic pathway through activating the AKT/mTOR and BDNF/TrkB/AKT/CREB signaling pathways and abating miRNA-634 and oxidative stress.

IFITM2 Presents Antiviral Response through Enhancing Type I IFN Signaling Pathway.

Interferon (IFN) helps cells fight viral infections by further inducing the expression of many downstream IFN-stimulated genes (ISGs). Human interferon-inducible transmembrane proteins (IFITM) are one of these ISGs. The antiviral function of human IFITM1, IFITM2, and IFITM3 are well known. In this study, we report that IFITM can significantly inhibit EMCV infectivity in HEK293 cells. Overexpression of IFITM proteins could promote IFN-β production. Meanwhile, IFITMs facilitated type I IFN signaling pathway adaptor MDA5 expression. We detected the binding of IFITM2 to MDA5 in a co-immunoprecipitation assay. It was also found that the ability of IFITM2 to activate IFN-β was significantly inhibited after interfering with MDA5 expression, suggesting that MDA5 may play an important role in the activation of the IFN-β signaling pathway by IFITM2. Moreover, the N-terminal domain plays an active role in the antiviral activity and the activation of IFN-β by IFITM2. These findings suggest that IFITM2 plays a vital role in antiviral signaling transduction. In addition, a positive feed-forward loop between IFITM2 and type I IFN establishes a key role for IFITM2 in enforcing innate immune responses.