Unraveling the role of the mitochondrial one-carbon pathway in undifferentiated thyroid cancer by multi-omics analyses

The role of the serine/glycine metabolic pathway (SGP) has recently been demonstrated in tumors; however, the pathological relevance of the SGP in thyroid cancer remains unexplored. Here, we perform metabolomic profiling of 17 tumor-normal pairs; bulk transcriptomics of 263 normal thyroid, 348 papillary, and 21 undifferentiated thyroid cancer samples; and single-cell transcriptomes from 15 cases, showing the impact of mitochondrial one-carbon metabolism in thyroid tumors. High expression of serine hydroxymethyltransferase-2 (SHMT2) and methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is associated with low thyroid differentiation scores and poor clinical features. A subpopulation of tumor cells with high mitochondrial one-carbon pathway activity is observed in the single-cell dataset. SHMT2 inhibition significantly compromises mitochondrial respiration and decreases cell proliferation and tumor size in vitro and in vivo. Collectively, our results highlight the importance of the mitochondrial one-carbon pathway in undifferentiated thyroid cancer and suggest that SHMT2 is a potent therapeutic target.

Tctp, a unique Ing5-binding partner, inhibits the chromatin binding of Enok in Drosophila

The MOZ/MORF histone acetyltransferase complex is highly conserved in eukaryotes and controls transcription, development, and tumorigenesis. However, little is known about how its chromatin localization is regulated. Inhibitor of growth 5 (ING5) tumor suppressor is a subunit of the MOZ/MORF complex. Nevertheless, the in vivo function of ING5 remains unclear. Here, we report an antagonistic interaction between Drosophila Translationally controlled tumor protein (TCTP) (Tctp) and ING5 (Ing5) required for chromatin localization of the MOZ/MORF (Enok) complex and H3K23 acetylation. Yeast two-hybrid screening using Tctp identified Ing5 as a unique binding partner. In vivo, Ing5 controlled differentiation and down-regulated epidermal growth factor receptor signaling, whereas it is required in the Yorkie (Yki) pathway to determine organ size. Ing5 and Enok mutants promoted tumor-like tissue overgrowth when combined with uncontrolled Yki activity. Tctp depletion rescued the abnormal phenotypes of the Ing5 mutation and increased the nuclear translocation of Ing5 and chromatin binding of Enok. Nonfunctional Enok promoted the nuclear translocation of Ing5 by reducing Tctp, indicating a feedback mechanism between Tctp, Ing5, and Enok to regulate histone acetylation. Therefore, Tctp is essential for H3K23 acetylation by controlling the nuclear translocation of Ing5 and chromatin localization of Enok, providing insights into the roles of human TCTP and ING5-MOZ/MORF in tumorigenesis.

Abstract 1388: Non-thermal plasma-activated medium induces ferroptotic cell death by intracellular ferrous iron overload in head and neck cancer

The notoriously high proliferation rate of cancer cells requires them to constantly deal with the balance adjustment between oxidative stress overload and upregulated protective antioxidant pathways. It puts them in a vulnerable state whenever one piece of this puzzle went out of control. Non-thermal plasma (NTP) is partially ionized gas operated at or around body temperature and has emerged as a new potential anti-cancer therapy due to its ability to release and induce ROS, RNS, and other free radicals as well as generate UV- photon and electromagnetic field; but the specific mechanism and its specificity to cancer cell are still controversial. Using transcriptomic analysis, we previously reported the link between NTP-activated media (NTPAM)and apoptosis; but the sequencing data also revealed a strong Ferroptotic response in all the 6Head and Neck cancer cell lines we checked. Ferroptosis is a newly identified oxidative-regulated cell death, characterized by the iron-dependent generation of lipid peroxidation. In this study, we found the prolonged treatment of NTPAM-induced cell death via the non-canonical ferroptosis pathway by directly increasing intracellular toxic ferrous Iron (Fe2+). We found that the excessive overexpression of HMOX1 under prolonged NTPAM-induced oxidative stress was actually responsible for the surge of intracellular Fe2+ due to the increase of heme degradation. Pharmacological inhibition or RNA silencing of HMOX1 was able to rescue 2 HNC cell lines from NTPAM-induced increased Iron concentration as well as ferroptosis cell death, both in vivo and in vitro. These results suggest NTP directly induces ferroptosis via an increase of Fe2+ concentration by triggering the over-responding of the NRF2 - HMOX1 antioxidant system. This finding could be exploited to develop future NTP-based cancer therapy as well as in combination with other Iron sensitive anti-neoplastic agents; and could be a potential method of overcoming conventional cancer treatment resistance.

Citation Format: QuocKhanh Nguyen, Chan Oh, Seung-Nam Jung, Yudan Piao, Mi Ae Lim, Young Il Kim, Yanli Jin, Hae Jong Kim, Bon Seok Koo. Non-thermal plasma-activated medium induces ferroptotic cell death by intracellular ferrous iron overload in 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 1388.

Mitochondrial ribosomal protein L14 promotes cell growth and invasion through modulating ROS in thyroid cancer

Objectives

The mitochondrial ribosomal protein L14 (MRPL14) is encoded by a nuclear gene and participates in mitochondrial protein translation. In this study, we aimed to investigate the role of MRPL14 in thyroid carcinoma.

Methods

We investigated the association of expression of MRPL14 and clinicopathological features using the The Cancer Genome Atlas (TCGA) and Chungnam National University Hospital (CNUH) databases. Functional studies of MRPL14, including proliferation, migration, invasion, mitochondrial oxidative phosphorylation and reactive oxygen species (ROS) production, were performed in papillary thyroid carcinoma (PTC) cell lines (B-CPAP and KTC-1).

Results

Based on TCGA dataset, PTC tissues lost mitochondrial integrity and showed dysregulated expression of overall mitoribosomal proteins (MRPs) compared with normal thyroid tissues. Of 78 MRPs, MRPL14 was highly expressed in thyroid carcinoma tissues. MRPL14 overexpression was significantly associated with advanced tumor stage, extrathyroidal extension, and lymph node metastasis. MRL14 increased cell proliferation of thyroid cancer and promoted cell migration via epithelial-mesenchymal transition-related proteins. Moreover, MRPL14 knockdown reduced the expression of oxidative phosphorylation complex IV (MTCO1) and increased the accumulation of ROS. Co-treatment with a ROS scavenger restored cell proliferation and migration reduced by MRPL14 knockdown, which imply that ROS functions as a key regulator of the oncogenic effects of MRPL14 in thyroid cancer cells.

Conclusion

Our findings indicate that MRPL14 may promote cell growth, migration, and invasion through modulating ROS in thyroid cancer cells.

Single Cell Analysis of Human Thyroid Reveals the Transcriptional Signatures of Aging

The thyroid gland plays a critical role in the maintenance of whole-body metabolism. However, aging frequently impairs homeostatic maintenance by thyroid hormones due to increased prevalence of subclinical hypothyroidism associated with mitochondrial dysfunction, inflammation, and fibrosis. To understand the specific aging-related changes of endocrine function in thyroid epithelial cells, we performed single-cell RNA sequencing (RNA-seq) of 54 726 cells derived from pathologically normal thyroid tissues from 7 patients who underwent thyroidectomy. Thyroid endocrine epithelial cells were clustered into 5 distinct subpopulations, and a subset of cells was found to be particularly vulnerable with aging, showing functional deterioration associated with the expression of metallothionein (MT) and major histocompatibility complex class II genes. We further validated that increased expression of MT family genes are highly correlated with thyroid gland aging in bulk RNAseq datasets. This study provides evidence that aging induces specific transcriptomic changes across multiple cell populations in the human thyroid gland.

Adrenomedullin2 stimulates progression of thyroid cancer in mice and humans under nutrient excess conditions

Thyroid cancer is associated with genetic alterations, e.g. BRAF^V600E , which may cause carcinomatous changes in hormone-secreting epithelial cells. Epidemiological studies have shown that overnutrition is related to the development and progression of cancer. In this study, we attempted to identify the cell nonautonomous factor responsible for the progression of BRAF^V600E thyroid cancer under overnutrition conditions. We developed a mouse model for inducible thyrocyte-specific activation of BRAF^V600E , which showed features similar to those of human papillary thyroid cancer. LSL-Braf^V600E ;TgCreER^T2 showed thyroid tumour development in the entire thyroid, and the tumour showed more abnormal cellular features with mitochondrial abnormalities in mice fed a high-fat diet (HFD). Transcriptomics revealed that adrenomedullin2 (Adm2) was increased in LSL-Braf^V600E ;TgCreER^T2 mice fed HFD. ADM2 was upregulated on the addition of a mitochondrial complex I inhibitor or palmitic acid with integrated stress response (ISR) in cancer cells. ADM2 stimulated protein kinase A and extracellular signal-regulated kinase in vitro. The knockdown of ADM2 suppressed the proliferation and migration of thyroid cancer cells. We searched The Cancer Genome Atlas and Genotype-Tissue Expression databases and found that increased ADM2 expression was associated with ISR and poor overall survival. Consistently, upregulated ADM2 expression in tumour cells and circulating ADM2 molecules were associated with aggressive clinicopathological parameters, including body mass index, in thyroid cancer patients. Collectively, we identified that ADM2 is released from cancer cells under mitochondrial stress resulting from overnutrition and acts as a secretory factor determining the progressive properties of thyroid cancer. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

SHMT2 Induces Stemness and Progression of Head and Neck Cancer

Various enzymes in the one-carbon metabolic pathway are closely related to the development of tumors, and they can all be potential targets for cancer therapy. Serine hydroxymethyltransferase2 (SHMT2), a key metabolic enzyme, is very important for the proliferation and growth of cancer cells. However, the function and mechanism of SHMT2 in head and neck cancer (HNC) are not clear. An analysis of The Cancer Genome Atlas (TCGA) data showed that the expression of SHMT2 was higher in tumor tissue than in normal tissue, and its expression was significantly associated with male sex, aggressive histological grade, lymph node metastasis, distant metastasis, advanced TNM stage, and lymphovascular invasion in HNC. SHMT2 knockdown in FADU and SNU1041 cell lines significantly inhibited cell proliferation, colony formation, migration, and invasion. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses using TCGA data revealed that SHMT2 was closely related to cancer stem cell regulation and maintenance. Furthermore, we found that silencing SHMT2 inhibited the expression of stemness markers and tumor spheroid formation compared with a control group. On the contrary, stemness markers were significantly increased after SHMT2 overexpression in HEP-2 cells. Interestingly, we found that knocking down SHMT2 reduced the expression of genes related to the Notch and Wnt pathways. Finally, silencing SHMT2 significantly reduced tumor growth and decreased stemness markers in a xenograft model. Taken together, our study suggests that targeting SHMT2 may play an important role in inhibiting HNC progression.

Transit time flow measurement (TTFM) as a predictor of graft failure and major adverse cardiac events following coronary artery bypass grafting (CABG)

Funding Acknowledgements

Type of funding sources: None.

Introduction

Post coronary artery bypass grafting (CABG), coronary angiography (CAG) is the gold standard for graft assessment to check the presence of occlusion or stenosis. Despite this, CAGs after a CABG in the nation are only conducted if patients show ischemic signs. Alternative to CAG, transit time flow measurement (TTFM) can be utilized to determine overall quality of blood flow in grafts. TTFM has yet been utilized to assess graft patency despite its availability in the nation.

Purpose

This study aims to provide TTFM profiles from CABG surgeries, including characterizing the differences in TTFM parameters between failed and normal grafts, as well as determining the association of TTFM parameters and related clinical factors to the likelihood of graft failure and major adverse cardiac events (MACE).

Methods

279 patients were admitted to the cardiology centre from 1 January 2017 to 31 December 2019. Mann-Whitney test was used to compare the differences in TTFM parameters across different graft types, as well as between failed and normal grafts. To determine the likelihood of a graft being normal or failed based on established TTFM parameter cutoffs, χ² test was used. Lastly, multivariate logistic regression was used to determine the association between TTFM parameters and MACE, specifically angina, myocardial infarction, and death.

Results

Different graft types exhibited significant differences in TTFM parameters, particularly pulsatility index (PI) and diastolic filling (%DF). Arterial grafts presented with higher quality of blood flow compared to venous grafts, with left-sided grafts (especially LIMA-LAD) being the graft type of highest quality (Refer to Fig.1).

However, there were no differences in TTFM parameters between failed and normal grafts (PI P = 0.893; DF% P = 0.143). Despite this, there was a greater number of failed grafts with PI > 5 (6.6%) compared to PI < 5 (2.6%) (χ²=4.021, P = 0.045).

Multivariate analysis showed no significant association between TTFM parameters and prevalence of MACE. Instead, an increased risk of graft failure is associated with the female gender (P = 0.031), history of congestive heart failure (P = 0.025) and poor renal function (P = 0.034). Also, an increased risk of MACE is associated with a history of coronary intervention (P = 0.041), left coronary dominance (P = 0.018) and renal function (P = 0.009).

Conclusion

This study provides an overview of the TTFM profiles among different graft types used in CABG surgeries. While TTFM are not indicative of failed grafts upon ischemic signs, patient comorbidities were informative. Follow-up studies should include a larger sample size of patients from an earlier timeframe to assess correlation of graft failure over a 5-to-10-year span post-CABG. Regardless of ischemic signs, routine CAG for all patients should be considered to determine the true prevalence of graft failure among CABG patients in the nation. Abstract Figure. Fig1.Median comparison TTFM Parameters  Abstract Figure. Fig2. Multivariate analysis models

The effect of Curcumin on multi-level immune checkpoint blockade and T cell dysfunction in head and neck cancer

BACKGROUND

Despite recent advances in understanding the complex immunologic dysfunction in the tumor microenvironment (TME), fewer than 20% of patients with head and neck squamous cell carcinoma (HNSCC) respond to immune checkpoint blockade (ICB). Thus, it is important to understand how inhibitory IC receptors maintain the suppressed dysfunctional TME, and to develop more effective combination immunotherapy. This study evaluated the immune-modulating effects of Curcumin, which has well-established anti-cancer and chemopreventive properties, and its long-term safety as a phytochemical drug.

METHODS

We carried out the western blot and small interfering RNA (siRNA) transfection assay to evaluate the effects of Curcumin on IC ligands and IC ligands function in HNSCC. Through T-cell cytotoxicity assay and measurements of cytokine secretion, we assessed the effects of combination of Curcumin with programmed death-ligand 1 (PD-L1) Ab on cancer cell killing. Flow cytometry were used to analyze the effects of Curcumin on the expression of programmed cell death protein 1 (PD-1) and T-cell immunoglobulin and mucin-domain3 (TIM-3) on CD4, CD8 and Treg. Immunofluorescence, immunohistochemistry and western blot were used to detecte the cytokine (IFN-γ, Granzyme B), IC receptors (PD-1 and TIM-3) and its ligands (PD-L1, PD-L2, Galectin-9) in xenograft mouse model and 4-nitroquinoline-1-oxide (4-NQO) oral cancer model.

RESULTS

We found that Curcumin decreased the expression of IC ligands such as PD-L1, PD-L2, and Galectin-9 in HNSCC, leading to regulation of epithelial-to-mesenchymal transition-associated tumor invasion. Curcumin also effectively restored the ability of CD8⁺ cytotoxic T cells to lyse cancer cells. To evaluate the effect of Curcumin on the TME further, the 4-NQO oral cancer model was used. Curcumin increased T-cell proliferation, tumor-infiltrating lymphocytes (TILs), and effector cytokines, and decreased the expression of PD-1, TIM-3, suppressive IC receptors and their ligands (PD-L1, PD-L2, and Galectin-9) in the TME, implying reinvigoration of the exhausted CD8⁺ T cells. In addition, Curcumin inhibited expression of CD4⁺CD25⁺FoxP3⁺ Treg cells as well as PD-1 and TIM-3.

CONCLUSIONS

These results show that Curcumin reinvigorates defective T cells via multiple (PD-1 and TIM-3) and multi-level (IC receptors and its ligands) IC axis suppression, thus providing a rationale to combine Curcumin with conventional targeted therapy or ICB as a multi-faceted approach for treating patients with HNSCC.

Transcriptional Regulation of GDF15 by EGR1 Promotes Head and Neck Cancer Progression through a Positive Feedback Loop

Growth and differentiation factor 15 (GDF15), a divergent member of the transforming growth factor-β (TGF-β) superfamily, has been reported to be overexpressed in different kinds of cancer types. However, the function and mechanism of GDF15 in head and neck cancer (HNC) remains unclear. The Cancer Genome Atlas (TCGA) data show that the expression of GDF15 is significantly associated with tumor AJCC stage, lymph vascular invasion and tumor grade in HNC. In this study, we confirmed that knockdown of GDF15 attenuated: cell proliferation, migration and invasion via regulation of EMT through a canonical pathway; SMAD2/3 and noncanonical pathways; PI3K/AKT and MEK/ERK in HNC cell lines. Furthermore, we found that early growth response 1 (EGR1) was a transcription factor of GDF15. Interestingly, we also demonstrated that GDF15 could regulate the expression of EGR1, which meant a positive feedback loop occurred between these two factors. Moreover, combined inhibition of both GDF15 and EGR1 in a HNC mouse xenograft model showed significantly decreased tumor volume compared to inhibition of EGR1 or GDF15 alone. Our study showed that the GDF15–EGR1 signaling axis may be a good target in HNC patients.

The association between serum prealbumin and poor outcome in COVID-19 - Systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the association between the prealbumin and severity and mortality in COVID-19.

MATERIALS AND METHODS

We performed a systematic literature search from PubMed, Embase, and Scopus databases up until 2 February 2021. The primary outcome was the poor outcome, a composite of mortality and severity. Severe COVID-19 was defined as COVID-19 that fulfill the criteria for severe pneumonia or patients with acute respiratory distress syndrome/disease progression/need for intensive care unit or mechanical ventilation. The effect estimates were a mean difference between patients with and without a poor outcome in mg/dL and odds ratio (OR) per 1 mg/dL decrease in prealbumin level. The effect estimates were reported with their 95% confidence interval (95% CI).

RESULTS

Nine studies comprising of 2104 patients were included in this systematic review and meta-analysis. Patients with poor outcome have lower prealbumin level (mean difference -71.48 mg/dL [95% CI -93.74, -49.22], p<0.001; I2: 85.9%). Every 1 mg/dL decrease in prealbumin level was associated with 1% increase in poor outcome (OR 0.992 [0.987, 0.997], p=0.004, I2: 81.7%). Meta-regression analysis showed that the association between the prealbumin level and poor outcome varies with gender (male) (coefficient: 3.50, R2: 100%, p<0.001), but not age, diabetes, hypertension, and chronic kidney disease.

CONCLUSIONS

Low serum prealbumin was associated with poor outcomes in patients with COVID-19.

Growth Differentiation Factor 15 is a Cancer Cell-Induced Mitokine That Primes Thyroid Cancer Cells for Invasiveness

Background: Mitochondrial stress is known to activate the mitochondrial unfolded protein response (UPR^mt). The UPR^mt results in the secretion of mitochondrial cytokines (mitokines), which can promote a hormetic response cell nonautonomously, and has been reported to be protumorigenic. Growth differentiation factor 15 (GDF15) is a well-characterized mitokine, which is reported to have a mitohormetic effect. Thus, we investigated whether GDF15 induction could prime a subpopulation of thyroid cancer cells to provide invasive advantages. Methods: The UPR^mt, including mitokine expression, was assessed in the context of thyroid cancer in vitro and in vivo. GDF15 expression in 266 patients with papillary thyroid carcinoma (PTC) was determined by immunohistochemistry. The serum levels of GDF15 were measured in healthy subjects and PTC patients. In addition, our own and The Cancer Genome Atlas data were analyzed to determine the expression level of GDF15 in thyroid cancers. The role of GDF15 in tumor aggressiveness was investigated by observing the effects of GDF15 knockdown in BCPAP, TPC-1, 8505C, and FRO cells. Results: Pharmacological inhibition of mitochondrial oxidative phosphorylation function in thyroid cancer cells robustly increased GDF15 expression. The expression of GDF15 was associated with activation of the mitochondrial integrated stress response pathway in PTC patients. Circulating GDF15 levels were significantly higher in PTC patients than in the controls, and tumor expression of GDF15 was related to tumor aggressiveness. In vitro and in vivo knockdown of GDF15 in a thyroid cancer model showed decreased viability, migration, and invasion compared with the control cells via regulation of STAT3. Conclusions: In this study, we demonstrated that GDF15 is a mitokine induced in thyroid cancer cells upon mitochondrial stress. GDF15-induced STAT3 activation determined tumor progression in thyroid cancer. The GDF15-STAT3 signaling axis may be a target in aggressiveness of thyroid cancer.

Effect of chronic obstructive pulmonary disease and smoking on the outcome of COVID-19

OBJECTIVE: To investigate the association between chronic obstructive pulmonary disease (COPD) and smoking with outcome in patients with COVID-19.METHODS: A systematic literature search was performed using PubMed, EuropePMC, SCOPUS and the Cochrane Central Database. A composite of poor outcome, mortality, severe COVID-19, the need for treatment in an intensive care unit (ICU) and disease progression were the outcomes of interest.RESULTS: Data on 4603 patients were pooled from 21 studies. COPD was associated with an increased risk for composite poor outcome (OR 5.01, 95%CI 3.06-8.22; P < 0.001; I² 0%), mortality (OR 4.36, 95%CI 1.45-13.10; P = 0.009; I² 0%), severe COVID-19 (OR 4.62, 95%CI 2.49-8.56; P < 0.001; I² 0%), ICU care (OR 8.33, 95%CI 1.27-54.56; P = 0.03; I² 0%), and disease progression (OR 8.42, 95%CI 1.60-44.27; P = 0.01; I² 0%). Smoking was found to increase the risk of composite poor outcome (OR 1.52, 95%CI 1.16-2.00; P = 0.005; I² 12%), and subgroup analysis showed that smoking was significant for increased risk of severe COVID-19 (OR 1.65, 95%CI 1.17-2.34; P = 0.004; I² 11%). Current smokers were at higher risk of composite poor outcomes (OR 1.58, 95%CI 1.10-2.27; P = 0.01; I² 0%) than former/non-smokers.CONCLUSION: Our systematic review and meta-analysis revealed that COPD and smoking were associated with poor outcomes in patients with COVID-19.

Effect of Urban Particulate Matter on Vocal Fold Fibrosis through the MAPK/NF-κB Signaling Pathway

Particulate matter (PM) is an environmental exposure factor that adversely affects human health. PM is a risk factor for various diseases. However, the mechanism by which PM affects the vocal folds (VF) has not yet been evaluated. Thus, we investigated the cytotoxic effects of PM on human vocal fold fibroblasts (hVFF) and the underlying signaling pathways. hVFF were isolated from human VF. The effect of PM on hVFF, and the underlying mechanism, were analyzed using Western blot, quantitative real-time polymerase chain reaction, and flow cytometry. In addition, a histological evaluation was performed in animal experiments. Cell proliferation decreased after the PM treatment. PM increased the expression of interleukin (IL)-6 and IL-1β. The generation of reactive oxygen species (ROS) in PM-treated hVFF and subsequent activation of the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways were confirmed. Furthermore, PM increased the expression of fibrosis-related markers and induced the accumulation of collagen in the extracellular matrix. As a result, PM exposure significantly enhances the inflammatory response on VF through the ROS-mediated activation of the MAPK and NF-κB signaling pathways. In addition, PM promotes differentiation into myofibroblasts and induces fibrosis. These results suggest that PM triggers an inflammatory reaction through ROS production and causes VF fibrosis.

Brn3a/Pou4f1 Functions as a Tumor Suppressor by Targeting c-MET/STAT3 Signaling in Thyroid Cancer

BACKGROUND

Brn3a/Pou4f1 is a class IV POU domain-containing transcription factor and has been found to be expressed in a variety of cancers. However, the mechanism and action of Brn3a in thyroid cancer has not been investigated.

PURPOSE

To investigate the role of Brn3a in thyroid cancer progression and its clinical implication.

METHODS

We examined Brn3a expression status in patients with thyroid cancer and analyzed relationships between Brn3a expression and clinicopathological findings using The Cancer Genome Atlas (TCGA) database. For functional in vitro analysis, proliferation, migration, invasion assay, and Western blotting were performed after overexpression or suppression of Brn3a.

RESULTS

The promoter hypermethylation of Brn3a was found in patients with aggressive thyroid cancer and Brn3a was downregulated in tissues of patients with thyroid cancer. In TCGA database, the low-Brn3a-expression group revealed a more aggressive phenotype, including T stage and extrathyroid extension when compared with the high-Brn3a-expression group. Overexpression of Brn3a suppressed cell migration and invasion via regulation of epithelial-mesenchymal transition (EMT)-associated proteins in thyroid cancer cell lines. Brn3a overexpression also downregulated signal transducer and activator of transcription 3 (STAT3) signaling through suppression of tyrosine-protein kinase Met (c-MET). In contrast, knockdown of Brn3a by small interfering ribonucleic acid (siRNA) significantly increased cell migration and invasion through upregulation of c-MET/STAT3. These results imply that Brn3a suppresses tumor metastasis via c-MET/STAT3 inhibition and EMT suppression in thyroid cancer.

CONCLUSIONS

Our findings show that Brn3a is a potential tumor suppressor that leads to reduced cancer cell migration and invasion in thyroid cancer. Elucidation of the Brn3a-regulated cancer pathways may therefore provide novel therapeutic strategies to control thyroid cancer metastasis.

Body mass index and outcome in patients with COVID-19: A dose-response meta-analysis

Background

There is mounting evidence related to the association between obesity and severity of COVID-19. However, the direct relationship of the increase in the severe COVID-19 risk factors, with an increase in body mass index (BMI), has not yet been evaluated.

Aim

This meta-analysis aims to evaluate the dose–response relationship between body mass index (BMI) and poor outcome in patients with COVID-19.

Methods

A systematic literature search was conducted using PubMed, Europe PMC, ProQuest, and the Cochrane Central Database. The primary outcome was composite poor outcome composed of mortality and severity. The secondary outcomes were mortality and severity.

Results

A total of 34,390 patients from 12 studies were included in this meta-analysis. The meta-analysis demonstrated that obesity was associated with composite poor outcome (OR 1.73 [1.40, 2.14], P < 0.001; I²: 55.6%), mortality (OR 1.55 [1.16, 2.06], P = 0.003; I²: 74.4%), and severity (OR 1.90 [1.45, 2.48], P < 0.001; I²: 5.2%) in patients with COVID-19. A pooled analysis of highest BMI versus reference BMI indicate that a higher BMI in the patients was associated with composite poor outcome (aOR 3.02 [1.82, 5.00], P < 0.001; I²: 59.8%), mortality (aOR 2.85 [1.17, 6.92], P = 0.002; I²: 79.7%), and severity (aOR 3.08 [1.78, 5.33], P < 0.001; I²: 11.7%). The dose–response meta-analysis showed an increased risk of composite poor outcome by aOR of 1.052 [1.028, 1.077], P < 0.001 for every 5 kg/m² increase in BMI (P_{non-linearity} < 0.001). The curve became steeper with increasing BMI.

Conclusion

Dose–response meta-analysis demonstrated that increased BMI was associated with increased poor outcome in patients with COVID-19.

Gas Sensor by Direct Growth and Functionalization of Metal Oxide/Metal Sulfide Core-Shell Nanowires on Flexible Substrates

We have developed a novel fabrication method for flexible gas sensors for toxic gases based on sequential wet chemical reaction. In specific, zinc oxide (ZnO) nanowires were locally synthesized and directly integrated on a flexible polymer substrate using localized hydrothermal synthesis methods and their surfaces were selectively functionalized with palladium (Pd) nanoparticles using a liquid phase deposition process. Because the entire process is conducted at a low temperature in a mild precursor solution, it can be applied for flexible substrates. Furthermore, the surface of ZnO nanowires was sulfurized by hydrogen sulfide (H₂S) gas to form zinc oxide/zinc sulfide (ZnO/ZnS) core-shell nanowires for stable sensing of H₂S gas. The locally synthesized ZnO/ZnS core-shell nanowires enable an ultracompact-sized device, and Pd nanoparticles improve the sensing performance and reduce the operating temperature (200 °C). The device shows a high sensitivity [(G_gas - G_air)/G_air × 100% = 4491% to 10 ppm], fast response (response/recovery time <100 s) to hydrogen sulfide, and outstanding selectivity (>100 times) to other toxic gases (e.g., carbon monoxide, acetone, ethanol, and toluene). Moreover, vertically synthesized nanowires provide a long bending path, which reduces the mechanical stresses on the structure. The devices showed stable gas sensing performance under 9 mm positive radius of curvature and 5 mm negative radius of curvature. The mechanical robustness of the device was also verified by numerical simulations which showed dramatic decrease of maximum stress and strain to 4.2 and 5.0%, respectively.

Abstract 795: GDF15, the putative mitokine factor, promotes tumor progression in thyroid cancer via STAT3 regulation

Purpose: As mitochondrial dysfunction is an integral component during the initial stages of tumorigenesis, mechanistic insight on the interaction between these two pathways may lead to novel therapeutic approaches. The aim of this study is to investigate the role of GDF15, the putative mitokine factor in thyroid tumorigenesis.

Methods: Expression levels of GDF15 was investigated using The Cancer Genome Atlas database. The role of GDF15 in tumor aggressiveness was investigated by analyzing the effects of knock-down of GDF15 on proliferation, migration, and invasion of thyroid cancer cells. Serum levels of GDF15 were measured in healthy subjects and patients with papillary thyroid cancer (PTC), and expression of GDF15 by IHC was investigated in PTC samples. To investigate the exact mechanism of GDF15 in thyroid cancer, both IPA analysis and GSEA analysis were performed using TCGA database and RNA seq data from Chungnam national university hospital.

Results: TCGA data revealed the higher expression of GDF15 in tumor samples compared to in paired non-tumor samples. Thyroid cancer cells with knock-down of GDF15 revealed the decrease of proliferation, migration, and invasion compared to control cells via regulation of STAT3. Higher serum levels of GDF15 were found in patients with thyroid cancer than in control participants, and were significantly associated with tumor stage, lymphovascular invasion, and recurrence. In addition, patients with high GDF15 expression by IHC revealed the aggressive phenotype compared to patients with low GDF15 expression.

Conclusions: GDF15 is a new biomarker for predicting tumor progression, and therapies targeting GDF15 may be effective for treating thyroid cancer.

Citation Format: Yea Eun Kang, Jae Won Chang, Lihua Liu, Kyoungmin Lee, Mi Ae Lim, Seung-Nam Jung, Chan Oh, Ho-Ryun Won, Minho Shong, Bon Seok Koo. GDF15, the putative mitokine factor, promotes tumor progression in thyroid cancer via STAT3 regulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 795.

A new route toward ultrasensitive, flexible chemical sensors: metal nanotubes by wet-chemical synthesis along sacrificial nanowire templates

We developed a novel low-temperature, wet-chemical process for the facile synthesis of metal nanotube arrays through the reduction of metal precursors along sacrificial metal oxide nanowire templates and demonstrated its applications to the ultrasensitive, low-power, mechanically robust, and flexible chemical sensors. The in situ dissolution of ZnO nanowire templates, which were hydrothermally grown on electrode surfaces, during the reaction allows the direct formation of tubular Pd nanostructures on the sensor devices without the need of complex processes for device integration or template removal. Moreover, this simple synthesis was carried out at low-temperature with mild chemical conditions; therefore we could make Pd nanotube devices not only on silicon substrates but also on flexible polymer substrates. The H(2) sensing of such Pd nanotube devices was investigated under various mechanical loading and showed excellent reliability and robustness. The sensitivity of our devices was found to be at least 2 orders of magnitude higher than literature values for H(2) sensors, which can be attributed to the high surface area and the well-formed interconnect of Pd tubular nanostructures in our devices.

Novel fabrication method of diverse one-dimensional Pt/ZnO hybrid nanostructures and its sensor application

A novel low-temperature, solution-phase method for the facile fabrication of a variety of one-dimensional (1D) metal/metal oxide hybrid nanostructures has been developed. This method is based on the wet chemical synthesis of metal oxide nanowires, followed by the surface coating of metal nanoparticles on metal oxide nanowire templates via reduction of metal ions along with controlled etching of metal oxide nanowires at the core, all in a low-temperature liquid environment. As a proof-of-concept, we applied this method to the fabrication of various 1D Pt/ZnO hybrid nanostructures including Pt nanoparticle-coated ZnO nanowires/nanotubes and Pt nanotubes on silicon and polymer substrates. The diverse morphology tuning is attributed to the control of pH in the solution with different metal precursor concentrations and amounts of reducing agent. The change of morphology, crystalline structure, and composition of various 1D Pt/ZnO hybrid nanostructures was observed by SEM, TEM (HRTEM), XRD and ICP-AES, respectively. Further, we have demonstrated a highly sensitive strain sensor (gauge factor = 15) with a Pt nanotube film fabricated by the developed method on a flexible polymer substrate.

The complete genome sequence and genome structure of frangipani mosaic virus

In this study, the complete sequence of the genomic RNA of frangipani mosaic virus (FrMV) has been determined and compared to those of other known tobamoviruses. The complete genome sequence of FrMV consisted of 6,643 nucleotides. The FrMV genomic RNA encoded four open reading frames (ORFs), for proteins of M(r) 128 kDa (1,147 aa), 186 kDa (1,651 aa), 30 kDa (257 aa) and 18 kDa (175 aa) from the 5' to the 3' end. Overall similarities for the four ORFs of FrMV-P ranged from 26.8 to 53.0% at the amino acid level when compared to those of 24 other tobamoviruses. Phylogenetic analysis of the FrMV replicase (186 kDa) and MP revealed that FrMV is closely related to SHMV and CMMoV, while the FrMV replicase (128 kDa) is more closely related to cucurbit-infecting and malvaceous-infecting tobamoviruses, and the FrMV CP is closely related to that of CMMoV and solanaceous-infecting tobamoviruses.

Clonidine, octopaminergic receptor agonist, reduces protein feeding in the blow fly, Phormia regina (Meigen)

Results in this study are consistent with those of Murdock and his colleagues who clearly demonstrated that clonidine, an agonist of octopaminergic receptors in some insects, significantly increases sucrose feeding. Their studies, however, did not examine the effect of clonidine on protein feeding. Injection of a 20 microg/microl/fly dose of clonidine significantly reduces protein feeding in both sexes of Phormia regina, instead of stimulating feeding as is observed with carbohydrate feeding. The manner in which the flies are fed prior to starvation and the method of testing influences the amounts of diet consumed. It is proposed that the biogenic amines influence the state of hunger (i.e., protein versus carbohydrates) while other chemicals and neural mechanisms (i.e., such as sulfakinins and stretch receptors, respectively) affect satiety.

Monitoring precursor chemicals of methamphetamine through enantiomer profiling

Smuggling of methamphetamine is affected by enforced regulation and international situation, resulting in changes of precursors and synthetic methods used. Enantiomer ratio of methamphetamine can provide information concerning its precursor and synthetic method. This information is useful for the prevention of smuggling methamphetamine and its precursor, and resultant reduction of methamphetamine abuse. In the present study, we investigated on the enantiomer ratios of 433 crystalline methamphetamine samples seized in Korea from 1994 to 2005. Excluding 17 samples of low purity, 416 samples were used for enantiomer profiling. The methamphetamine samples were derivatized with (S)-(+)-alpha-methoxy-alpha-(trifluoromethyl)phenylacetyl chloride ((S)-(+)-MTPACl), and the derivatives were analyzed by GCMS in selected ion monitoring (SIM) mode. The enantiomer ratios of the samples were calculated from the standard calibration curves of each enantiomer, both of which showed good linearity in the range of 0-1.2 microg. Most of the seizures were pure S(+)-enantiomer, but 21% (95 of 416 samples) contained R(-)-enantiomer above 1%. They began to appear from 1997, and increased continuously up to 50% in the year 2005 (55 of 111 samples). From this study, we could find out that alternative precursors have been used recently for the illicit manufacture of methamphetamine seized in Korea.

Ligand-dependent particle size control of PbSe quantum dots

Colloidal solutions of monodisperse PbSe quantum dots (QDs) were synthesized by a hot solution chemical method from a reaction mixture of lead oleate and TOPSe (TOP: tri-n-octylphosphine). The synthesis was carried out at a fixed temperature (170 degrees C) and time, while the particle sizes of the PbSe QDs were controlled by using two different kinds of organic ligands with varied chain length. It was seen that the tuning of PbSe QDs are possible by using the proper molar ratio of the co-ligands, such as acetic acid or hexanoic acid, at a fixed reaction temperature and time, verified by TEM and XRD as well as NIR absorption analysis. The effects of different organic acids were studied and the role of additional organic acids might be due to the extent of ligand exchange efficiency between the Pb oleate and acetic/hexanoic acid in the initial stage, which is caused by the steric hindrance effects of the acids.

Analysis of the impurities in the methamphetamine synthesized by three different methods from ephedrine and pseudoephedrine

Organic impurities of methamphetamine may show different patterns by synthesis. In the present study, we tried to find the impurities reflecting the conditions of synthesis by comparing impurity patterns of the methamphetamine samples synthesized by different methods. Sixteen methamphetamine samples were synthesized from ephedrine and pseudoephedrine by the three different manufacturing methods of Emde, Nagai and Moscow. The synthesized samples were extracted with ethyl acetate containing four internal standards, and the patterns of the organic impurities were investigated by GC-MS and GC-FID . Through the investigation, we found 10 peaks appearing in the latter part of GC chromatograms are characteristic to synthesis. The areas of the selected peaks were converted to the variables suitable for the statistical calculation, and the synthesized samples could be classified into four groups through the resultant cluster analysis.

Blood concentrations of amitriptyline and its metabolite in rats after acute oral administration of amitriptyline

Amitriptyline (AMT), a tricyclic antidepressant that is a dibenzocycloheptadine derivative, is frequently used. However, the case reports of AMT-related fatalities are increased, nowadays, due to the low levels of toxic and fatal concentration in blood. So, this study was carried out to determine the concentrations of AMT and its demethylated metabolite, nortriptyline (NTR), after acute single oral administration of AMT in rats. Blood samples were collected five times from the ophthalmic venous plexus at 0, 1, 2, 4, and 8 h after acute single oral administration of AMT in toxic doses of 10 (Group I) or 20 mg/kg (Group II), and the concentrations of AMT and NTR and the mean ratios of AMT to NTR (AMT/NTR) in the blood were periodically determined at designated times. The blood concentrations of AMT and NTR were identified and quantitated by gas chromatography with thermionic specific detection and gas chromatography-mass spectrometry after solid-phase extraction with a Clean Screen DAU column. The peak blood concentrations of AMT and NTR in Group I were 0.34 and 0.28 microg/mL, respectively, and those of AMT and NTR in Group II were 0.59 and 0.43 microg/mL, respectively, and were reached at 1 h after single oral administration.

Double-blind trial to find dose range using a fixed combination of mefloquine, sulfadoxine and pyrimethamine in falciparum malaria: a field study on adults in Burma

In a field study conducted in Burma, 60 semi-immune adults were randomly assigned to 2 treatment groups. The first (mean parasite count, 12717/mm3) received a single dose of a fixed combination of 500 mg mefloquine base, 1000 mg sulfadoxine and 50 mg pyrimethamine (2 tablets of 'Fansimef') plus 1 tablet placebo. The second group (mean parasite count, 11 863/mm3) were given 3 tablets of the same medication. The study was double-blind. Parasite count was checked daily for the first week and weekly for a further 3 weeks. Average times for parasite clearance were 1.47 d in patients receiving 2 tablets, and 1.87 d in those given 3 tablets. Asexual parasites reappeared on day 28 in one patient in each group, although they had been free of parasites during the previous 4 weeks; this could be due to reinfection. The drugs were generally well tolerated, though mild and transient giddiness was seen in 80% of patients in the first group and 96% in the second. Nausea was reported by 33% and 43% of patients respectively. No vomiting occurred in the first group but 8 patients vomited in the second (P less than 0.01). In conclusion it seems possible to treat falciparum malaria in semi-immune adults, weighing less than 60 kg, with a single dose of 500 mg mefloquine base, 1000 mg sulfadoxine and 50 mg pyrimethamine (2 tablets), instead of the higher dose (3 tablets) currently recommended. This reduces treatment cost and improves tolerance of the drugs.

Characteristics of normal labour among different racial groups in Malaysia

The characteristics of normal labour in 977 Malay, Chinese and Indian parturients were established from a retrospective study. Indian babies were found to be significantly smaller than Malay babies which were significantly smaller than Chinese babies (P less than 0-05, P less than 0-05). The mean duration of the first stage of labour taken from the time of admission to the labour ward was 3-4 hours in primiparae and 2-7 hours in multiparae. The mean durations of the second stage of labour were 23-7 minutes and 13-1 minutes respectively. Curves of mean dilatation of cervix and probit analysis at 80% revealed significant differences in the progress of normal labour in primiparae among the three racial groups. The Indian primiparae not only had a slower rate of cervical dilatation but seemed to reach the accelerated phase of dilatation later. No significant differences were noticed in the labours of multiparae.