Fit-for-purpose characterization of air-liquid-interface (ALI) in vitro exposure systems for e-vapor aerosol

Air-liquid-interface (ALI) exposure systems deliver aerosol to the apical surface of cells which mimics the in vivo inhalation exposure conditions. It is necessary, however, to quantify the delivered amount of aerosol for ALI-based in vitro toxicity assessment. In this study, we evaluated two commercially available ALI exposure systems, a Vitrocell® Ames 48 (Ames 48) and a Vitrocell® 24/48 (VC 24/48), and the Vitrocell® VC1/7 smoking machine using a cig-a-like cartridge-based e-vapor device with a prototype formulation (containing 4% nicotine by weight). We characterized aerosol particle-size distribution, aerosol mass, and major chemical components (nicotine, propylene glycol, and glycerol) at the generation source and verified the repeatability of the aerosol generation. We determined aerosol delivery at the ALI by gravimetric analysis of mass collected on Cambridge filter pads and analytical quantitation of the buffer medium which showed that both aerosol mass and nicotine to an exposure insert linearly increased up to 400 puffs. The delivered aerosol mass covered a wide range of 0.8-3.4 mg per insert in the Ames 48 with variability (relative standard deviation, RSD) up to 12% and 1.1-6.4 mg per insert in the VC 24/48 with variability up to 15%. The delivered nicotine ranged approximately up to 200 μg per insert in both exposure systems. These results provided operation and aerosol delivery information of these ALI exposure systems for subsequent in vitro testing of e-vapor aerosols.

Network modeling of anxiety and psychological characteristics on suicidal behavior: Cross-sectional study

BACKGROUND

Suicide is influenced by complex interactions among various psychopathological features. We aimed to examine the relationship between suicide risk and psychological risk factors such as defense mechanisms, personality, and anxiety.

METHODS

We established a psychiatric database by utilizing the Observational Medical Outcomes Partnership Common Data Model. We conducted a 1:1 propensity score matching with age, sex, and depression severity, and identified a sample (n = 258) with two groups: those with suicidal behavior and those with non-suicidal behavior. Using principal component analysis, we extracted nine psychological scales and applied network analysis to compare relationships among psychological factors between the two groups.

RESULTS

Patients with non-suicidal behaviors showed associations between trait anxiety and defense mechanisms, while those with suicidal behaviors did not. For patients with suicidal ideation there was an association between somatization and trait anxiety. Patients with suicide attempts showed associations between paranoia and dissociation connected to trait anxiety.

LIMITATIONS

Longitudinal research is required to fully observe transitions from suicidal ideation to attempts and recurrent suicidal events. In addition, these networks may not generalize suicidal behaviors because the group participants are not homogeneous. Lastly, data from self-report questionnaires limits the reliability of responses.

CONCLUSIONS

We presented important new insights on suicidal behavior by estimating psychological networks. Patients with non-suicidal behavior may exhibit discrete relationships between defense mechanisms and anxiety, compared to those with suicidal behavior. Patients with suicidal ideation and suicide attempts may show distinct associations between anxiety and psychopathological features.

Abstract PD3-07: Combined inhibition of CDK4/6 and AKT is effective in Rb-intact triple-negative breast cancer of the luminal androgen receptor (LAR) subtype

Background: Triple-negative breast cancer (TNBC) is a heterogeneous disease group with variable clinico-pathologic features. Based on gene expression profiles, TNBCs are grouped into 6 major subtypes. The Luminal androgen receptor (LAR) subtype is enriched for potentially targetable biomarkers, including high androgen receptor (AR) expression, high rates of PIK3CA mutations, and intact Rb. The purpose of this study was to investigate the most effective combinations of CDK4/6, AR, and PI3K-AKT inhibitors in pre-clinical models of LAR TNBC for future clinical trial design. Methods: MDA-MB-453 and MFM-223 (both Rb-intact/PTEN-intact/PIK3CA-mutant) and CAL-148 (Rb-null/PTEN-null/PIK3CA-mutant) LAR TNBC cell lines were treated with the CDK4/6 inhibitor palbociclib, the PI3Kα inhibitor alpelisib, the AKT inhibitor capivasertib, and the AR antagonist enzalutamide, each alone or in different combinations. Drug sensitivity was determined by coulter counter cell counts in 2D, colony formation, and the CellTiterGlo cell viability assay. The combination index (CI) which defines synergism (CI < 1), additive effect (CI = 1) and antagonism (CI > 1), calculated by the CompuSyn method, was used to evaluate the synergistic effects of drug combinations. Expression of cell cycle and PI3K-AKT downstream signaling molecules was measured by western blot analysis. An androgen response element (ARE) luciferase-based reporter assay was used to evaluate AR transcriptional activity. Results: Rb-intact LAR TNBC cell lines were sensitive to single-agent palbociclib, alpelisib or capivasertib (IC50, ~500 nM). Enzalutamide had minimal growth inhibitory activity (IC50, 15-25 μM). Palbociclib combined with either alpelisib or capivasertib synergistically inhibited proliferation of LAR TNBC cells (CI values, 0.07-0.86). Treatment of Rb-intact LAR TNBC cells with palbociclib monotherapy suppressed Rb phosphorylation and resulted in adaptive phosphorylation/activation of S473 AKT and AKT substrates GSKβ and PRAS40 at 24h. These responses were not observed in Rb-null CAL-148 cells. Palbociclib-induced phosphorylation of AKT substrates as well as induction P-S6 and P-4EBP1 were better suppressed by capivasertib than by alpelisib over a dose range. Addition of the PI3Kβ/δ inhibitor AZD8186 to alpelisib markedly enhanced the inhibition of P-AKT, P-PRAS40 and P-Sin, suggesting inhibition of PI3Kα is inadequate to block the adaptive response to palbociclib in these cells. Mean CI values showed that the combination of palbociclib/capivasertib was more synergistic against LAR TNBC cells compared to palbociclib/alpelisib (mean CI, 0.29 vs. 0.78). ARE reporter activity did not change upon inhibition of PI3K or AKT with alpelisib or capivasertib, respectively. Conclusions: Our results suggest that addition of an AKT inhibitor to palbociclib suppresses the rebound activation of AKT following treatment with the CDK4/6i and is effective in LAR TNBC with wild type Rb. In vivo studies are underway to investigate the antitumor activity of the combination of palbociclib and capivasertib in LAR TNBC xenografts.

Citation Format: Gun Min Kim, Kyung-min Lee, Dhivya Sudhan, Albert Lin, Arnaldo Marin, Sumanta Chatterjee, Dan Ye, Vishal Kandagatla, Saurabh Mendiratta, Ariella Hanker, Carlos Arteaga. Combined inhibition of CDK4/6 and AKT is effective in Rb-intact triple-negative breast cancer of the luminal androgen receptor (LAR) subtype [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD3-07.

Abstract P5-17-09: A genome-wide CRISPR screen identifies PRMT5 as a novel therapeutic target in ER+/RB1-deficient breast cancer

Background: CDK4/6 inhibitors (CDK4/6i) have improved survival of patients with advanced estrogen receptor-positive (ER+) breast cancer. However, this benefit is transient as virtually all these tumors eventually develop drug resistance and recur. Clinical studies have reported an association of RB1 loss-of-function genomic alterations with acquired resistance to CDK4/6i. Given the enrichment of RB1 alterations post CDK4/6i treatment, ER+/RB1-deficient breast cancer will become a rising patient population in need of discovery of novel treatment strategies. In this study, we sought to identify actionable vulnerabilities for this refractory breast cancer subtype using a genome-wide CRISPR screen. Methods: RB1 was knocked out in ER+ MCF-7 and T47D breast cancer cells using CRISPR-Cas9; complete gene knockout was confirmed by PCR-based genotyping, Sanger sequencing, and immunoblot analysis. Isogenic RB1 knockout (RBKO) and wild-type (WT) T47D cells were used for the genome-wide CRISPR screen. MAGeCKFlute was used to identify differentially essential genes in T47D RBKO vs WT cells; Gene Ontology (GO) analysis was used to prioritize hits. MCF-7 and T47D RBKO cells were used for validating and studying the function of the identified genes. Results: Knockout of RB1 in MCF-7 and T47D cells increased IC50 of abemaciclib, palbociclib, and ribociclib 10-200 fold compared to WT cells. RNA-seq analysis showed upregulation of E2F target gene expression in RBKO vs WT cells. The CRISPR screen revealed that CCND1 and CDK4 lost their essentiality in T47D RBKO cells, suggesting that loss of RB1 uncouples the CDK4/Cyclin D1 complex from E2F-regulated transcription. GO analysis of the top 50 differentially essential hits of RBKO vs WT cells showed an enrichment of protein arginine methyltransferase activity, primarily PRMT5, which post-translationally mono-methylates and symmetrically di-methylates protein arginine. In agreement with this finding, PRMT5 knockout by three individual sgRNAs resulted in more potent growth inhibition of MCF-7 and T47D RBKO cells than WT cells. Further, transfection of PRMT5 siRNA or treatment with the PRMT5 small molecule inhibitor GSK3326595 - currently in clinical trials - resulted in G1 arrest of MCF-7 and T47D RBKO cells as assayed by propidium iodide staining but did not induce caspase 3/7 or PARP cleavage (apoptosis). RNA-seq of PRMT5 siRNA vs control siRNA in MCF-7 and T47D RBKO cells exhibited significant downregulation of E2F Hallmark gene signature, further suggesting PRMT5 inhibition as a strategy to suppress E2F-regulated gene expression when cells lose Rb. The CRISPR screen also revealed that transcription factors that drive ER signaling, such as FOXA1, GATA3, MYC, SPDEF, and ESR1 (the gene encoding ERα), were commonly essential in both T47D WT and RBKO cells. Estrogen deprivation or treatment with fulvestrant inhibited estrogen responsive element (ERE) luciferase reporter activity, expression of putative E2F target genes, and proliferation of both WT and RBKO cells, suggesting that ER+ cells still rely on ERα irrespective of RB1 status. Treatment of MCF-7 and T47D RBKO cells with fulvestrant and GSK3326595 resulted in more potent growth inhibition than each drug alone, suggesting a novel approach to treat ER+/RB1-deficient breast cancer. We are currently testing the antitumor activity of fulvestrant plus GSK3326595 against RBKO xenografts as well as the requirement of arginine methyltransferase activity associated with PRMT5 for growth of ER+/RB1-deficient breast cancer cells. Conclusion: PRMT5 is essential for proliferation of ER+/RB1-deficient breast cancer cells. Targeting PRMT5 in combination with anti-estrogens is a novel and testable strategy to suppress E2F-regulated cell cycle progression of this CDK4/6 inhibitor-resistant breast cancer subtype.

Citation Format: Chang-Ching Lin, Tsung-Cheng Chang, Alberto Servetto, Kyung-min Lee, He Zhang, Yunguan Wang, Dan Ye, Sumanta Chatterjee, Dhivya R Sudhan, Hiroaki Akamatsu, Yang Xie, Joshua T Mendell, Ariella B Hanker, Carlos L Arteaga. A genome-wide CRISPR screen identifies PRMT5 as a novel therapeutic target in ER+/RB1-deficient breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-17-09.

Abstract GS3-09: Loss of ASXL1 tumor suppressor promotes resistance to CDK4/6 inhibitors in ER+ breast cancer

Background: CDK4/6 inhibitors (CDK4/6i) in combination with antiestrogens have prolonged survival of patients with ER+ metastatic breast cancer. However, this combination is not curative mainly due to acquired drug resistance. Knowledge about mechanisms of such resistance remains quite incomplete. We report herein a forward-genetics screen to discover a broad spectrum of novel somatic mutations causal to CDK4/6i resistance. Methods: We used CRISPR/Cas9 to delete the DNA mismatch repair (MMR) gene MSH2 in MCF7 and T47D ER+ breast cancer cells. Deficiency of DNA MMR proteins such as MSH2 results in a high nucleotide substitution rate which, in turn, predisposes cells to acquire drug resistance-associated mutations. MSH2-/- MCF7 and T47D cells were infected with a lentiviral barcode library containing ~1000 unique DNA barcodes. MSH2-/- barcoded cells were expanded for ~25 doublings to allow the accumulation of random mutations. Clones resistant to CDK4/6i were selected in the presence of IC90 of palbociclib (200 nM) or abemaciclib (500 nM) for 4-6 weeks. CDK4/6i resistant clones with unique barcode IDs were subjected to whole exome sequencing (WES). Results: Following drug selection, ~73 uniquely barcoded resistant colonies emerged from MCF7 and T47D MSH2-/- clonal lines. As expected, MCF7 and T47D MSH2-/- clones harbored a high mutation burden compared to parental cells. Candidate variants were distilled based on (a) functionality prediction and (b) mutation frequency in Project GENIE. We observed RB1 (5/73 clones; 6.8%) mutations in CDK4/6i resistant clones, providing proof-of-principle that this approach can identify clinically-relevant drug resistant alterations. Overall, we identified non-synonymous alterations in 2,206 genes in T47D palbociclib-resistant, 2,195 genes in T47D abemaciclib-resistant, and 1,312 genes in MCF7 palbociclib-resistant lines. A secondary screen of the 10 genes recurrently mutated in all three CDK4/6i resistant groups identified loss of ASXL1 as top hit. ASXL1 encodes a polycomb repressive complex protein that regulates chromatin accessibility. Loss of ASXL1 has been implicated in myeloid transformation through epigenetic reprogramming. WES of 76 CDK4/6i resistant tumor biopsies (DFCI/MBCproject cohort) identified ASXL1 alterations in two and four patients with acquired and primary resistance, respectively (6/76=7.9%). One of the tumors that progressed after an initial response to palbociclib had acquired the same ASXL1 R549C mutation that was identified in our screen. Among 1,769 tumors from patients treated with CDK4/6i (TEMPUS database), 37 exhibited ASXL1 alterations (4 frameshift, 6 truncating, 3 in-frame del, 24 missense mutations). DNAseq of patient-derived organoids established from post-CDK4/6i metastases identified ASXL1 mutations in 2/7 organoids (29%). ASXL1-/- MCF7 and T47D cells were cross-resistant to fulvestrant. GSEA analysis of RNA-seq data showed upregulation of E2F targets in palbociclib-treated cells stably transduced with ASXL1 shRNA but not control shRNA (Enrichment score=0.75, q=1.00E-09). This was associated with maintenance of RB phosphorylation in the presence of CDK4/6i, markedly higher levels of CDK2, CDK6, cyclins E and A, and downregulation of p21 and p27. Finally, siRNAs targeting CDK2 or cyclin A reduced the viability of ASXL1-deficient T47D cells by 50% and 90%, respectively. Conclusions: An accelerated mutagenesis approach using MMR-deficient ER+ breast cancer cells identified loss of ASXL1 as a novel mechanism of resistance to CDK4/6i. ASXL1 alterations were found in ~8% of tumors from patients with de novo or acquired resistance to CDK4/6i. Knockdown of CDK2 and cyclin A restored sensitivity to CDK4/6i and reduced viability of ASXL1 deficient cells, suggesting CDK2 inhibitors are a treatment approach against these drug-resistant tumors.

Citation Format: Dhivya R. Sudhan, Sumanta Chatterjee, Jiwoong Kim, Yunguan Wang, Vishal Kandagatla, Dan Ye, Chang-Ching Lin, Jorge Gomez Tejeda Zanudo, Esha Jain, Arnaldo Marin, Alberto Servetto, Kyung-min Lee, Juan Manuel Povedano, David McFadden, Alex Barrett, Nikhil Wagle, Ariella B. Hanker, Carlos L. Arteaga. Loss of ASXL1 tumor suppressor promotes resistance to CDK4/6 inhibitors in ER+ breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS3-09.

A Deep Learning Algorithm for Classifying Diabetic Retinopathy Using Optical Coherence Tomography Angiography

Purpose

To develop an automated diabetic retinopathy (DR) staging system using optical coherence tomography angiography (OCTA) images with a convolutional neural network (CNN) and to verify the feasibility of the system.

Methods

In this retrospective cross-sectional study, a total of 918 data sets of 3 × 3 mm² OCTA images and 917 data sets of 6 × 6 mm² OCTA images were obtained from 1118 eyes. A deep CNN and four traditional machine learning models were trained with annotations made by a retinal specialist based on ultra-widefield fluorescein angiography. Separately, the same images of the test data sets were independently graded by two human experts. The results of the CNN algorithm were compared with those of traditional machine learning–based classifiers and human experts.

Results

The proposed CNN achieved an accuracy of 0.728, a sensitivity of 0.675, a specificity of 0.944, an F1 score of 0.683, and a quadratic weighted κ of 0.908 for a six-level staging task, which were far superior to the results of traditional machine learning methods or human experts. The CNN algorithm showed a better performance using 6 × 6 mm² rather than 3 × 3 mm² sized OCTA images and using combined data rather than a separate OCTA layer alone.

Conclusions

CNN-based classification using OCTA images can provide reliable assistance to clinicians for DR classification.

Translational Relevance

This CNN algorithm can guide the clinical decision for invasive angiography or referrals to ophthalmology specialists, helping to create more efficient diagnostic workflow in primary care settings.

Hyperpolarization-activated cyclic nucleotide-gated channels working as pacemaker channels in colonic interstitial cells of Cajal

Hyperpolarization‐activated cyclic nucleotide‐gated (HCN) channels function as pacemaker channels in spontaneously active cells. We studied the existence of HCN channels and their functional roles in the interstitial cells of Cajal (ICC) from the mouse colon using electrophysiological, immunohistochemical and molecular techniques. HCN1 and HCN3 channels were detected in anoctamin‐1 (Ca²⁺‐activated Cl⁻ channel; ANO1)‐positive cells within the muscular and myenteric layers in colonic tissues. The mRNA transcripts of HCN1 and HCN3 channels were expressed in ANO1‐positive ICC. In the deletion of HCN1 and HCN3 channels in colonic ICC, the pacemaking potential frequency was reduced. Basal cellular adenylate cyclase activity was decreased by adenylate cyclase inhibitor in colonic ICC, whereas cAMP‐specific phosphodiesterase inhibitors increased it. 8‐Bromo‐cyclic AMP and rolipram increased spontaneous intracellular Ca²⁺ oscillations. In addition, Ca²⁺‐dependent adenylate cyclase 1 (AC1) mRNA was detected in colonic ICC. Sulprostone, a PGE₂‐EP₃ agonist, increased the pacemaking potential frequency, maximum rate of rise of resting membrane in pacemaker potentials and basal cellular adenylate cyclase activity in colonic ICC. These results indicate that HCN channels exist in colonic ICC and participate in generating pacemaking potentials. Thus, HCN channels may be therapeutic targets in disturbed colonic motility disorders.

Thirteen-week nose-only inhalation exposures of propylene glycol aerosols in Sprague Dawley rats with a lung systems toxicology analysis

The objectives of this study were to increase PG exposure above concentrations tested by Suber et al. and use systems toxicology analysis of lung tissue to understand molecular events. Sprague Dawley rats were exposed to filtered air (sham), propylene glycol/water (PG/W; 90:10) or a propylene glycol/vegetable glycerin/water (PG/VG/W; 50:40:10) reference. The reference group was added at the high dose to observe any changes that might be associated with a carrier more in line with e-vapor products. Macroscopic examinations and terminal organ weights revealed no observations associated with exposure to PG/W or reference. Food consumption and body weights were unaffected by PG/W or reference when compared to sham. No exposure related alterations were observed in serum chemistry, hematology, coagulation, urinalysis or BALF cytology and clinical chemistry. Although clinical observations of dried red material around the nose in the high dose PG/W group were reported, histopathology showed no nasal hemorrhaging which was previously reported by Suber et al. Non-adverse PG/W and reference related findings of minimal mucous cell hyperplasia were noted in nasal cavity section II. No other exposure-related findings were noted in the primary or recovery necropsies. A systems toxicology analysis on lung tissue showed no statistically significant differentially expressed transcripts or proteins compared to the sham group. The endpoints measured from the PG/W high dose group did not differ significantly from those in the more common carrier PG/VG/W. As anticipated, exposure to PG aerosols was slightly irritating but well tolerated. Accordingly, the highest PG exposure (5 mg/L, 6 hrs/day) was regarded as the NOAEC, corresponding to a PG delivered dose of 1,152 mg/kg/day in rats.

Forebrain glutamatergic neuron-specific Ctcf deletion induces reactive microgliosis and astrogliosis with neuronal loss in adult mouse hippocampus

CCCTC-binding factor (CTCF), a zinc finger protein, is a transcription factor and regulator of chromatin structure. Forebrain excitatory neuron-specific CTCF deficiency contributes to inflammation via enhanced transcription of inflammation-related genes in the cortex and hippocampus. However, little is known about the long-term effect of CTCF deficiency on postnatal neurons, astrocytes, or microglia in the hippocampus of adult mice. To address this, we knocked out the Ctcf gene in forebrain glutamatergic neurons (Ctcf cKO) by crossing Ctcf-floxed mice with Camk2a-Cre mice and examined the hippocampi of 7.5-10-month-old male mice using immunofluorescence microscopy. We found obvious neuronal cell death and reactive gliosis in the hippocampal cornu ammonis (CA)1 in 7.5-10-month-old cKO mice. Prominent rod-shaped microglia that participate in immune surveillance were observed in the stratum pyramidale and radiatum layer, indicating a potential increase in inflammatory mediators released by hippocampal neurons. Although neuronal loss was not observed in CA3, and dentate gyrus (DG) CTCF depletion induced a significant increase in the number of microglia in the stratum oriens of CA3 and reactive microgliosis and astrogliosis in the molecular layer and hilus of the DG in 7.5-10-month-old cKO mice. These results suggest that long-term Ctcf deletion from forebrain excitatory neurons may contribute to reactive gliosis induced by neuronal damage and consequent neuronal loss in the hippocampal CA1, DG, and CA3 in sequence over 7 months of age.

Autophagy activity contributes to the impairment of social recognition in Epac2-/- mice

Autophagy is a lysosomal degradation pathway that regulates cellular homeostasis. It is constitutively active in neurons and controls the essential steps of neuronal development, leading to its dysfunction in neurodevelopmental disorders. Although mTOR-associated impaired autophagy has previously been reported in neurodevelopmental disorders, there is lack of information about the dysregulation of mTOR-independent autophagy in neurodevelopmental disorders. In this study, we investigated whether the loss of Epac2, involved in the mTOR-independent pathway, affects autophagy activity and whether the activity of autophagy is associated with social-behavioral phenotypes in mice with Epac2 deficiencies. We observed an accumulation of autophagosomes and a significant increase in autophagic flux in Epac2-deficient neurons, which had no effect on mTOR activity. Next, we examined whether an increase in autophagic activity contributed to the social behavior exhibited in Epac2^-/- mice. The social recognition deficit observed in Epac2^-/- mice recovered in double transgenic Epac2^-/-: Atg5^+/- mice. Our study suggests that excessive autophagy due to Epac2 deficiencies may contribute to social recognition defects through an mTOR-independent pathway.

A Case of Hyperreactio Luteinalis Complicated With Biochemical Hyperandrogenism, Symptomatic Hyperthyroidism and Preeclampsia

Background: Hyperreactio luteinalis (HL) describes the development of multiple large ovarian cysts during pregnancy, which regress post-partum. We report a case of HL complicated with preeclampsia, biochemical hyperandrogenism and hyperthyroidism. Clinical Case: A 31-year-old non-obese Chinese woman presented at 14-week gestation for lower abdominal pain. USG showed a single fetus, multiple ovarian cysts with largest measured 39.5ml. She complained of hand tremor, palpitation but no vomiting. She had no goiter, orbitopathy or family history of thyroid disease. fT4 was 23.1pmol/L (normal: 9.8-19.8pmol/L) and TSH was <0.01mIU/L. Anti-TG, anti-TPO and anti-TSHR antibodies were negative. She had history of silent miscarriage at 6-week gestation in her first pregnancy 2 years ago, USG showed normal ovaries at that time. Carbimazole was started at 16-week gestation for fT4 26.6pmol/L (normal: 9.4-18.5pmol/L). The largest ovarian cyst increased to 130ml at 19-week gestation. Serum β-hCG was 251926IU/L (normal: 4060-165400IU/L). HL with hCG-mediated hyperthyroidism was suspected. Serum total testosterone was 22.9nmol/L (normal: 2.2-10.7nmol/L) and serum androstenedione was 70.5nmol/L (normal: 0.28-9.81nmol/L). Ferriham Gallwey score was 4. fT4 fell to 13.8pmol/L (normal: 8.8-17.0pmol/L) but TSH remained suppressed. Carbimazole was stopped at 22-week gestation with no rebound in fT4 level. She developed preeclampsia and GDM at 27-week gestation. IUGR was evident despite decreasing β-hCG level and ovarian cyst shrinkage. She had emergency LSCS for severe preeclampsia at 33-week gestation. A 1510g female baby with normal genitalia was delivered. Placenta pathology was normal. 2 days after delivery, β-hCG fell to 7081IU/L; fT4 was 9.9pmol/L (normal: 9-19pmol/L) and TSH was 0.25mIU/L (normal: 0.35-4.5mIU/L). Clinical Lessons: 1) hCG stimulates growth of ovarian stroma and androgen secretion, results in virilization in 30% of HL patients. However, only 5% of patients had hyperthyroidism. LH and hCG are structurally similar and bind to the same receptor. In contrast, hCG is a weak agonist of TSH receptor: a hCG level of more than 100000IU/L is required to cause clinical thyrotoxicosis. Since 30% of HL patients have normal hCG level, this may explain the lower incidence of hyperthyroidism than hyperandrogenism. 2) Degree of maternal virilization does not correlate with testosterone level. Study by Condic et al. found significant overlap of testosterone levels in women with (13.7-197.5nmol/l) and without (6.2-37.3nmol/l) virilization. Genetic polymorphism of androgen receptor may account for the different clinical manifestation. Fetal virilization is rare, due to protective role of placental aromatase. 3) Elevated hCG in apparently “normal” singleton pregnancy may be due to poor placentation in early gestation and is a risk factor for preeclampsia and IUGR in HL patients.

Epac: new emerging cAMP-binding protein

The well-known second messenger cyclic adenosine monophosphate (cAMP) regulates the morphology and physiology of neurons and thus higher cognitive brain functions. The discovery of exchange protein activated by cAMP (Epac) as a guanine nucleotide exchange factor for Rap GTPases has shed light on protein kinase A (PKA)-independent functions of cAMP signaling in neural tissues. Studies of cAMP-Epac-mediated signaling in neurons under normal and disease conditions also revealed its diverse contributions to neurodevelopment, synaptic remodeling, and neurotransmitter release, as well as learning, memory, and emotion. In this mini-review, the various roles of Epac isoforms, including Epac1 and Epac2, highly expressed in neural tissues are summarized, and controversies or issues are highlighted that need to be resolved to uncover the critical functions of Epac in neural tissues and the potential for a new therapeutic target of mental disorders.

Abstract GS1-06: FGFR1 associates with gene promoters and regulates gene transcription: Implications for endocrine resistance in ER+/FGFR1-amplified breast cancer

Background: FGFR1 amplification occurs in ~ 15% of ER+ breast cancers. In these tumors, nuclear FGFR1 has been shown to interact with DNA, but its role in transcriptional regulation is unclear. Thus, we investigated the genomic role of FGFR1 in ER+/FGFR1-amplified breast cancer. Results: FGFR1 ChIP-Seq detected 4,412 DNA binding sites in CAMA1 ER+/FGFR1-amplified breast cancer cells cultured in estrogen-free conditions. Of these binding sites, 67% were enriched at promoter regions. ChIP-qPCR confirmed FGFR1 binding to several promoter regions in a second ER+/FGFR1-amplified cell line, MDA-MB-134, and a patient derived xenograft, HCI-011. To determine the nuclear FGFR1 interactome, we performed FLAG immunoprecipitation of mixed nuclear and chromatin fractions of CAMA1 cells transduced with a 3XFLAG-FGFR1 plasmid, followed by mass spectrometry (MS) of FLAG antibody pulldowns. MS revealed RNA Polymerase II subunits among the top nuclear FGFR1 interacting proteins. FGFR1 mainly bound Pol II phosphorylated on Ser5 (Pol II S5P), a marker of transcription initiation, in CAMA1, MDA-MB-134 and HCI-011 cell extracts. Pol II S5P ChIP-Seq revealed that 2,867/4,412 (65%) FGFR1 peaks were shared with Pol II S5P. ChIP-Seq also showed that 95% of FGFR1 peaks overlapped with both H3K4me3 and H3K27ac, markers of active transcription. Consistent with these results, RNA-Seq of CAMA1 cells showed that expression of FGFR1-bound genes was markedly higher than non FGFR1-bound genes (p&lt;0.0001), suggesting that FGFR1 binds to actively transcribed genes. In addition to Pol II, MS detected FOXA1 among FGFR1 interacting proteins. ChIP-Seq analysis revealed FOXA1 enriched at FGFR1-bound loci. siRNA-mediated FOXA1 knockdown reduced FGFR1 distribution to several genomic loci in CAMA1 cells, as measured by FGFR1 ChIP-Seq, suggesting that FOXA1 mediates FGFR1 recruitment to chromatin. We next transduced MCF-7 cells with an FGFR1(SP-)(NLS) plasmid, where the NLS sequence forces nuclear import of the resulting protein. To determine the role of FGFR1 on transcriptional regulation, we used Binding and Expression Target Analysis (BETA), integrating FGFR1 ChIP-Seq and RNA-Seq results from MCF7FGFR1(SP-)(NLS) vs MCF7EV cells. This analysis predicted a direct role for genomic-bound FGFR1 in activating gene expression (p=8.01e-6). MCF7FGFR1(SP-)(NLS) cells were markedly less sensitive to fulvestrant compared to control cells. Gene Set Enrichment Analysis (GSEA) of the 1,009 genes upregulated in MCF7FGFR1(SP-)(NLS) cells and bound by FGFR1 at a genomic level revealed a strong enrichment of estrogen response early (q=2.2e-44) and late (q=6.4e-33) genes, suggesting that nuclear FGFR1 induces an ERα-associated transcriptional profile that may contribute to endocrine resistance. Finally, an expression signature associated with nuclear FGFR1 correlated with endocrine resistance in three cohorts of patients with ER+ breast cancer treated with aromatase inhibitors. We next studied the effect of growth factor stimulation on FGFR1 transcriptional function. Stimulation with FGF2 enhanced nuclear FGFR1 import in CAMA1 cells, as well as FGFR1-Pol II S5P association. Notably, these effects were not abrogated by treatment with the FGFR1 inhibitor erdafitinib. ChIP-Seq revealed that erdafitinib did not impair the FGFR1 genomic distribution. These results do not support a causal link between the FGFR1 activated TK and the receptor’s activity in the nucleus. Conclusions: We have demonstrated a role for nuclear FGFR1 in transcriptional regulation in breast cancer. FGFR1-induced gene expression contributes to endocrine resistance and is not affected by FGFR TKIs. These findings provide a rationale for developing treatment strategies to inhibit nuclear FGFR1 in ER+/FGFR1-amplified breast cancer.

Citation Format: Alberto Servetto, Rahul Kollipara, Luigi Formisano, Chang-Ching Lin, Kyung-min Lee, Dhivya R Sudhan, Ariella B Hanker, Sumanta Chatterjee, Angel Guerrero-Zotano, Paula Gonzalez-Ericsson, Saurabh Mendiratta, Hiroaki Akamatsu, Nicholas James, Ralf Kittler, Carlos L Arteaga. FGFR1 associates with gene promoters and regulates gene transcription: Implications for endocrine resistance in ER+/FGFR1-amplified breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr GS1-06.

Conditional knock out of transcription factor CTCF in excitatory neurons induces cognitive deficiency

CCCTC-binding factor (CTCF) is a transcription factor that is involved in organizing chromatin structure. A reduction of CTCF expression is known to develop distinct clinical features. Furthermore, conditional knock out (cKO) study revealed reactive gliosis of astrocytes and microglia followed by age-dependent cell death in the excitatory neurons of CTCF cKO mice. To assess the cognitive ability in CTCF cKO mice of over 20 weeks of age, we examined pairwise discrimination (PD), PD reversal learning (PDr), and different paired-associate learning (dPAL) tasks using a touch screen apparatus. We found cognitive impairment in dPAL touch screen tests, suggesting that prolonged Ctcf gene deficiency results in cognitive deficits.

Trends in the pricing and reimbursement of new anticancer drugs in South Korea: an analysis of listed anticancer drugs during the past three years

Objective: This study aimed to examine patient accessibility to new anticancer drugs including reimbursement coverage, time to listing, and listing price during the recent 3 years after the introduction of alternative pricing and reimbursement pathways in South Korea.Methods: Anticancer drugs were selected for analysis from the new drugs reviewed from January 2017 to March 2020. Descriptive statistics were used to present the levels of the listing prices. Pearson's correlation analysis was used to analyze the relationship between the list price in comparison to the External Reference Price(ERP) and the time to listing.Results: Thirty-two anticancer drugs were included in analysis. The average time to listing for these drugs was 36.7 months. The ratio of the listing price in comparison with Average Adjusted Price from seven reference countries was from 12.6% to 90.2%. Pearson's correlation coefficient for the correlation between the ratio of the listing price to the ERP and the time to listing was -0.37 and was statistically significant (p = 0.035).Conclusions: Policies that relate to the scope of reimbursement, time to reimbursement, and list price should be able to equally reflect patient accessibility and national health insurance finances, as well as the impact on industry as a whole.

Effect of Anti-glaucoma Agents on Myopic Retinoschisis

Purpose

To evaluate the effect of intraocular pressure (IOP)-lowering medications on myopic retinoschisis.

Methods

The medical records of 33 patients (36 eyes) with myopic retinoschisis associated with pathologic myopia were reviewed retrospectively. The patients were divided into two groups: the study group comprising patients undergoing treatment with anti-glaucoma medications for suspected glaucoma; the control group comprising patients who did not use any IOP lowering medications. The changes in retinoschisis in the two groups were compared using the Spectralis domain optical coherence tomography thickness map protocol.

Results

The study group included 18 eyes (17 patients), and the control group included 18 eyes (16 patients). There were no significant differences between the 6-month and 12-month improvement or aggravation rates of the two groups (p = 0.513 and 0.137, respectively). However, after 18 months, the aggravation rate of retinoschisis was significantly lower in the study group (p = 0.003). The improvement / aggravation rate was 58.33% / 16.67% in the study group and 0% / 57.14% in the control group.

Conclusions

The use of IOP-lowering medications for more than a year may be useful for the management of retinoschisis associated with pathologic myopia.

Dsg2-mediated c-Met activation in anaplastic thyroid cancer motility and invasion

Anaplastic thyroid cancer (ATC) is a rapidly growing, highly metastatic cancer with limited therapeutic alternatives, thus targeted therapies need to be developed. This study aimed to examine desmoglein 2 (Dsg2) expression in ATC and its biological role and potential as a therapeutic target in ATC. Consequently, Dsg2 was downregulated or aberrantly expressed in ATC tissues. ATC patients with low Dsg2 expression levels also presented with distant metastasis. Dsg2 depletion significantly increased cell migration and invasion, with a relatively limited effect on ATC cell proliferation in vitro and increased distant metastasis in vivo. Dsg2 knockdown induced cell motility through the hepatocyte growth factor receptor (HGFR, c-Met)/Src/Rac1 signaling axis, with no alterations in the expression of EMT-related molecules. Further, specific targeting of c-Met significantly inhibited the motility of shDsg2-depleted ATC cells. Decreased membrane Dsg2 expression increased the metastatic potential of ATC cells. These results indicate that Dsg2 plays an important role in ATC cell migration and invasiveness. Therapies targeting c-Met might be effective among ATC patients with low membrane Dsg2 expression levels, indicating that the analysis of Dsg2 expression potentially provides novel insights into treatment strategies for ATC.

Perseverative stereotypic behavior of Epac2 KO mice in a reward-based decision making task

Successfully navigating dynamic environments requires balancing the decision to stay at an optimal choice with that to switch to an alternative to acquire new knowledge. However, the genetic factors and cellular activity shaping this "stay or switch" action decision remains largely unidentified. Here we find that mice carrying a deletion of the exchange protein directly activated by cAMP 2 (Epac2) gene, a putative autism locus, exhibit perseverative "stay" behavior in a dynamic foraging task. Anatomical analysis found that the loss of Epac2 resulted in a significant decrease in the density of PV-expressing interneurons in the ventrolateral orbitofrontal cortex (OFC) and dorsal striatum (dSTR). Further, in vitro whole cell patch clamp recordings of PV⁺ GABAergic interneurons in the dSTR revealed altered neural activity in Epac2 KO mice in response to dopamine. Our findings highlight a potential role of Epac2 in structural changes and neural responses of PV-expressing GABAergic interneurons in the ventrolateral OFC and dSTR during value-based reinforcement learning and link Epac2 function to abnormal decision-making processes and perseverative behaviors seen in autism.

Application of 3D tooth model for monitoring of implant space and inter-root distance without radiographs: a proof of concept study

BACKGROUND

Radiographs are integral in evaluating implant space and inter-root distance. The purpose of this report is to introduce a method for evaluating the 3D root position with minimal radiation using a 3D tooth model composed of an intraoral-scanned crown and a cone-beam computed tomography (CBCT)-scanned root.

MATERIALS AND METHODS

Intraoral scan and CBCT scan of the patient were obtained before treatment. In the CBCT image, tooth segmentation was performed by isolating individual teeth from the maxillary and mandibular alveolar bone using software program. The 3D tooth model was fabricated by combining segmented individual teeth with the intraoral scan.

RESULTS

A post-treatment intraoral scan was integrated into the tooth model, and the resulting position of the root could be predicted without additional radiographs. It is possible to monitor the root position after a pretreatment CBCT scan using a 3D tooth model without additional radiographs.

CONCLUSION

The application of the 3D tooth model benefits the patient by reducing repeated radiation exposure while providing the clinician with a precise treatment evaluation to monitor tooth movement.

Loss of the neuronal genome organizer and transcription factor CTCF induces neuronal death and reactive gliosis in the anterior cingulate cortex

CCCTC-binding factor (CTCF) is a genome organizer that regulates gene expression through transcription and chromatin structure regulation. CTCF also plays an important role during the developmental and adult stages. Cell-specific CTCF deletion studies have shown that a reduction in CTCF expression leads to the development of distinct clinical features and cognitive disorders. Therefore, we knocked out Ctcf (CTCF cKO) in the excitatory neurons of the forebrain in a Camk2a-Cre mouse strain to examine the role of CTCF in cell death and gliosis in the cortex. CTCF cKO mice were viable, but they demonstrated an age-dependent increase in reactive gliosis of astrocytes and microglia in the anterior cingulate cortex (ACC) from 16 weeks of age prior to neuronal loss observed at over 20 weeks of age. Consistent with these data, qRT-PCR analysis of the CTCF cKO ACC revealed changes in the expression of inflammation-related genes (Hspa1a, Prokr2 and Itga8) linked to gliosis and neuronal death. Our results suggest that prolonged Ctcf gene deficiency in excitatory neurons results in neuronal cell death and gliosis, possibly through functional changes in inflammation-related genes.

Parvalbumin-expressing GABAergic interneurons and perineuronal nets in the prelimbic and orbitofrontal cortices in association with basal anxiety-like behaviors in adult mice

Parvalbumin-expressing (PV⁺) GABAergic interneurons are the principal inhibitory interneurons in the cortex, and a decrease in their number or PV protein expression is associated with changes in brain function. PV⁺ neurons are surrounded by the perineuronal net (PNN), a reticular extracellular matrix structure surrounding the soma and proximal dendrites. Although the prefrontal cortex is critically involved in anxiety-like behavior, it is not known how cortical PV⁺ neurons enwrapped with PNN contribute to basal anxiety behavior. To address the issue, we employed Wisteria floribunda agglutinin (WFA) to label the PNN and measured the densities and PV immunofluorescence of PV⁺ neurons, including those enwrapped with PNN (i.e., PV⁺WFA⁺ neurons) in the orbitofrontal (OFC) and prelimbic cortices of mice whose basal anxiety levels had been assessed in the open field test. We found that these densities, but not PV expression according to immunofluorescence intensity, were positively correlated with the percentage of time spent and the distance traveled in the center of an open field. Thus, these data demonstrate that the densities of OFC PV⁺ and PV⁺WFA⁺ neurons are significantly inversely correlated with basal anxiety levels of adult mice measured in the open field test and may represent a target for future anxiolytic therapeutics.

Evaluation of Bioabsorbable Mg-Mn Alloy with Anodic Oxidation Treatment

Magnesium alloys as biodegradable materials have been examined that may replace bone screws and plates in recent studies. But the velocity control of magnesium alloy is very difficult. Until now, the magnesium alloys degrade very fast, thus it couldn't maintain the function in clinical field. Thus the purpose of this study is to evaluate the degradability of anodized magnesium alloy for control the velocity. For this experiment, a Mg-xMn (x = 0, 0.5, 1 wt%) binary alloy was cast in argon gas (99.99%) atmosphere. The specimens of the surface treatment group were anodized for 15 minutes at a voltage of 120 V at room temperature using calcium gluconate, sodium hexametaphosphate, and sodium hydroxide electrolyte. For the mechanical test, SEM, roughness test, hardness test were examined. The degradation test was conducted to measure the hydrogen gas formation volume. For biologic test, cell viability were tested. After anodic oxidation treatment, the surface showed the crater formation, the size of craters were about 200~300 nm. Among nonanodized group, the Mg-0.5Mn showed the highest Vickers hardness and cell viability. However for biodegradability test, Mg-1Mn showed the lowest the hydrogen gas formation. For anodic oxidation treatment, anodic oxidation treatment makes rougher surface, higher hardness, good cell response and lower degradation rate. Overall, anodized Mg-1Mn showed the possibility for clinical application in bone screw and bone plate.

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.

Analysis of temperature-dependent abnormal bursting patterns of neurons in Aplysia

Temperature affects the firing pattern and electrical activity of neurons in animals, eliciting diverse responses depending on neuronal cell type. However, the mechanisms underlying such diverse responses are not well understood. In the present study, we performed in vitro recording of abdominal ganglia cells of Aplysia juliana, and analyzed their burst firing patterns. We identified atypical bursting patterns dependent on temperature that were totally different from classical bursting patterns observed in R15 neurons of A. juliana. We classified these abnormal bursting patterns into type 1 and type 2; type 1 abnormal single bursts are composed of two kinds of spikes with a long interspike interval (ISI) followed by short ISI regular firing, while type 2 abnormal single bursts are composed of complex multiplets. To investigate the mechanism underlying the temperature dependence of abnormal bursting, we employed simulations using a modified Plant model and determined that the temperature dependence of type 2 abnormal bursting is related to temperature-dependent scaling factors and activation or inactivation of potassium or sodium channels.