Dysregulation Of Gene Expression Research Articles

Comprehensive characterization of somatic mutations associated with chimeric RNAs in human cancers.

Chimeric RNAs, which can arise from gene recombination at the DNA level or non-canonical splicing events at the RNA level, have been identified as important roles in human tumors. Dysregulated gene expression caused by somatic mutations and altered splicing patterns of oncogenes or tumor suppressor genes can contribute to the development of tumors. Therefore, investigating the formation mechanism of chimeric RNAs via somatic mutations is critical for understanding tumor pathogenesis. This project is the first to propose studying the association between somatic single nucleotide variants and chimeric RNAs, identifying around 2900 somatic SNVs affecting chimeric RNAs in pan-cancer level. The somatic SNVs on chimeric RNAs were commonly observed in various types of tumor tissues, providing a valuable resource for future study. Additionally, these SNVs show distinct tumor specificity, and those with high frequency had a significant impact on the survival time of patients with tumors. Further research revealed that somatic SNVs associated with chimeric RNA (chiR-SNVs) were typically found within 10 nt of the junction site of chimeric RNAs and had a particularly significant effect on chimeric RNAs from different chromosomes. The enrichment analysis revealed that chiR-SNVs were significantly overrepresented in oncogenes and genes related to RNA binding proteins involved in RNA splicing, which could imply that chiR-SNVs may disrupt the process of RNA splicing and induce the occurrence of chimeric RNAs. This study sheds light on the potential molecular interaction mechanism between somatic SNVs and chimeric RNAs, which opens up a new avenue for researching disease pathway and tumorigenesis development.

Synthetic Lethality between Cohesin and WNT Signaling Pathways in Diverse Cancer Contexts.

Cohesin is a highly conserved ring-shaped complex involved in topologically embracing chromatids, gene expression regulation, genome compartmentalization, and genome stability maintenance. Genomic analyses have detected mutations in the cohesin complex in a wide array of human tumors. These findings have led to increased interest in cohesin as a potential target in cancer therapy. Synthetic lethality has been suggested as an approach to exploit genetic differences in cancer cells to influence their selective killing. In this study, we show that mutations in ESCO1, NIPBL, PDS5B, RAD21, SMC1A, SMC3, STAG2, and WAPL genes are synthetically lethal with stimulation of WNT signaling obtained following LY2090314 treatment, a GSK3 inhibitor, in several cancer cell lines. Moreover, treatment led to the stabilization of β-catenin and affected the expression of c-MYC, probably due to the occupancy decrease in cohesin at the c-MYC promoter. Finally, LY2090314 caused gene expression dysregulation mainly involving pathways related to transcription regulation, cell proliferation, and chromatin remodeling. For the first time, our work provides the underlying molecular basis for synthetic lethality due to cohesin mutations and suggests that targeting the WNT may be a promising therapeutic approach for tumors carrying mutated cohesin.

Internal m 6 A and m 7 G RNA modifications in hematopoietic system and acute myeloid leukemia.

Epitranscriptomics focuses on RNA modifications-mediated post-transcriptional regulation of gene expression. The current decade has witnessed tremendous progress in understanding the landscapes and biological functions of RNA modifications as prompted by potent analytical approaches. The hematopoietic system provides a lifelong supply of blood cells, and gene expression is tightly modulated during the differentiation of hematopoietic stem cells (HSCs). Dysregulation of gene expression during hematopoiesis may lead to severe disorders, including acute myeloid leukemia (AML). Emerging evidence has indicated the involvement of mRNA modification system in normal hematopoiesis and AML pathogenesis, which led to the accelerating development of small-molecule inhibitors targeting N6-methyladenosine (m 6 A) modification machinery for treatment. Here, we summarize the latest findings and address the state-of-the-art knowledge on the role of m 6 A and N7-methylguanine (m 7 G) in both physiological and pathological conditions in the hematopoietic system. Furthermore, we discuss the therapeutic potential and limitations of cancer treatment targeting m 6 A.

The Involvement of the microRNAs miR-466c and miR-340 in the Palmitate-Mediated Dysregulation of Gonadotropin-Releasing Hormone Gene Expression

Diets high in saturated fatty acids are associated with obesity and infertility. Palmitate, the most prevalent circulating saturated fatty acid, is sensed by hypothalamic neurons, contributing to homeostatic dysregulation. Notably, palmitate elevates the mRNA levels of gonadotropin-releasing hormone (Gnrh) mRNA and its activating transcription factor, GATA binding protein 4 (Gata4). GATA4 is essential for basal Gnrh expression by binding to its enhancer region, with Oct-1 (Oct1) and CEBP-β (Cebpb) playing regulatory roles. The pre- and post-transcriptional control of Gnrh by palmitate have not been investigated. Given the ability of palmitate to alter microRNAs (miRNAs), we hypothesized that palmitate-mediated dysregulation of Gnrh mRNA involves specific miRNAs. In the mHypoA-GnRH/GFP neurons, palmitate significantly downregulated six miRNAs (miR-125a, miR-181b, miR-340, miR-351, miR-466c and miR-503), and the repression was attenuated by co-treatment with 100 μM of oleate. Subsequent mimic transfections revealed that miR-466c significantly downregulates Gnrh, Gata4, and Chop mRNA and increases Per2, whereas miR-340 upregulates Gnrh, Gata4, Oct1, Cebpb, and Per2 mRNA. Our findings suggest that palmitate may indirectly regulate Gnrh at both the pre- and post-transcriptional levels by altering miR-466c and miR-340, which in turn regulate transcription factor expression levels. In summary, palmitate-mediated dysregulation of Gnrh and, consequently, reproductive function involves parallel transcriptional mechanisms.

Maternal RNA transcription in Dlk1-Dio3 domain is critical for proper development of the mouse placental vasculature

The placenta is a unique organ for ensuring normal embryonic growth in the uterine. Here, we found that maternal RNA transcription in Dlk1-Dio3 imprinted domain is essential for placentation. PolyA signals were inserted into Gtl2 to establish a mouse model to prevent the expression of maternal RNAs in the domain. The maternal allele knock-in (MKI) and homozygous (HOMO) placentas showed an expanded junctional zone, reduced labyrinth and poor vasculature impacting both fetal and maternal blood spaces. The MKI and HOMO models displayed dysregulated gene expression in the Dlk1-Dio3 domain. In situ hybridization detected Dlk1, Gtl2, Rtl1, miR-127 and Rian dysregulated in the labyrinth vasculature. MKI and HOMO induced Dlk1 to lose imprinting, and DNA methylation changes of IG-DMR and Gtl2-DMR, leading to abnormal gene expression, while the above changes didn’t occur in paternal allele knock-in placentas. These findings demonstrate that maternal RNAs in the Dlk1-Dio3 domain are involved in placental vasculature, regulating gene expression, imprinting status and DNA methylation.

Abstract 6146: Characterizing underlying molecular mechanisms of prostate cancer risk variants identified from multi-ethnic GWAS

Abstract Prostate cancer (PCa) is a complex disease with the second leading cause of cancer death in US males. Multi-ethnic genome-wide association studies (GWAS) identified a thousand genetic variants associated with PCa risk in different races. However, the majority of risk variants are located in non-coding regions, making it challenging to understand their contribution to PCa risk. Non-coding regions include functional regulatory elements (REs) such as promoters and enhancers, whose activity can be evaluated by histone modification H3K4me3 and H3K27ac, respectively. In this study, we integrated PCa risk variants with hundreds of H3K4me3 and H3K27ac ChIP-seq data from normal and cancer prostate cell lines and tissues, finding 122 variants in promoters and 301 variants in enhancers. Enhancers are distal to promoters, and they form loops to regulate gene expression, mediated by transcription factors (TFs). Enhancer activities are tightly associated with cell fate. Genetic variants can affect the activity of enhancers by changing the binding preference of TFs and such changes can affect chromatin interactions and dysregulate gene expression. We hypothesize that allele changes of enhancer variants contribute to PCa risk differently among individuals from different ancestries, leading to the development of heterogeneous PCa molecular subgroups, characterized by genetic alterations including TMPRSS2-ERG fusion. By integrating H3K27ac ChIP-seq data from prostate cell lines derived from European (EUR) and African (AFR) ancestries, we found 185 risk variants in enhancers in EUR cell lines and 69 risk variants in enhancers in AFR cell lines. Next, we integrated patient tissue-derived H3K27ac ChIP-seq data and performed chromatin quantitative trait loci (cQTL) and allelic imbalance (AI) analyses to determine risk variants associated with enhancer activity. Among the 185 risk enhancer variants in EUR and 69 in AFR cell lines, we found 130 and 46 with significant association, respectively. To determine TFs that change binding upon allele change of enhancer risk variants, we integrated hundreds of TF ChIP-seq data from prostate cell lines and tissues. Among the 185 risk enhancer variants in EUR and 69 in AFR cell lines, we found 142 and 44 variants bound by TFs, respectively. When we further performed cQTL and AI analyses for FOXA1, HOXB13, and AR, we found 87 and 29 variants significantly associated with TF binding affinity, respectively. Moreover, we found that these associations differ between TMPRSS2-ERG fusion positive and negative tumors. To identify the target genes of enhancer risk variants, we are currently integrating chromatin interaction data including Hi-C and Micro-C. Overall, this study provides valuable insights into the underlying molecular mechanisms of risk variants in various populations and individuals which lead to the development of heterogeneous PCa subgroups. Citation Format: Zexun Wu, Andrew Vu, Ethan S. Nelson-Moore, Huan Cao, Suhn K. Rhie. Characterizing underlying molecular mechanisms of prostate cancer risk variants identified from multi-ethnic GWAS [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6146.

Abstract 4579: DNMT1 determines the sensitivity of Class I HDAC inhibitor Psammaplin A to induce apoptosis and DNA damage in hematological malignant cells

Abstract Histone deacetylases (HDACs) and DNA methyltransferases (DNMTs) are overexpressed in cancer cells associated with dysregulated gene expression and tumor progression. DNMT1 partnered with Class I HDAC as complex to inhibit gene transcription. Several pan-HDAC inhibitors have been approved for T-cell lymphoma with evident side effects. More selective HDAC inhibitors need to be developed. Psammaplin A (PsA), a symmetrical bromotyrosine-derived disulfide dimer isolated from the Psammaplysilla sponge, is a selective Class I HDAC inhibitor. We tested its cell growth inhibition and apoptosis induction in 12 hematological malignant cell lines with 8 lines sensitive (more than 50% growth inhibition at 1 μM) and 4 lines insensitive (less than 20% growth inhibition at 1 μM). PsA induces acetylation of H3, but not α-tubulin, supporting the Class I HDAC inhibition selection. In the sensitive cell lines, PsA induces apoptosis with down-regulation of c-Flip and upregulation of NOXA as well as DNA damage detected by γ-H2A.X. RNA sequence analysis results confirm the regulation of PsA on NOXA, c-Flip and p21 gene expression. The four insensitive cell lines express high levels of DNMT1 with resistance to apoptosis induction. Silencing DNMT1 with siRNA sensitizes PsA-induced apoptosis with induction of NOXA and γ-H2A.X. Azacytidine, the DNMT1 degrader, in combination with PsA induce synergistic cell growth inhibition and apoptosis in vitro. PsA (20 mg/kg) plus Azacytidine (2.5 mg/kg) synergistically inhibit tumor growth in insensitive mantle cell lymphoma Jeko-1 xenografts, without detected toxic signs in organ pathological analysis. We find a new mechanism of DNMT1 controlling the sensitivity of Class I HDAC inhibitor PsA and provide a rationale of PsA with azacytidine for combination therapy. Citation Format: Yu Bao, Dan Liu, Zi Wu, Yumei He, Ping Gong, Samuel Waxman, Yongkui Jing. DNMT1 determines the sensitivity of Class I HDAC inhibitor Psammaplin A to induce apoptosis and DNA damage in hematological malignant cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4579.

Abstract 6916: InnoPanelTMand InnoPediaTM: resources of engineered cell lines and xenografts for drug discovery

Abstract The Development of precision medicine relies on well-characterized experimental models that carry naive, induced, or engineered genomic and epigenetic features targetable by certain treatments. Patient-derived xenografts (PDX) and cell lines can serve as such in vivo and in vitro models by harboring abnormalities such as somatic and driver mutations, dysregulated gene expression and silencing, microsatellite instability, gene fusions, copy number amplification and loss of heterozygosity. In addition, cell lines can also be engineered to introduce sometimes rare-occurring abnormalities that the engineered cell line shares an identical genetic background with its parental cell line, thus providing a clearly contrasting pair to evaluate treatment specificity. With the advancement of disease research and drug discovery, existing cell lines can no longer meet the needs of various types of drug discovery. To evaluate drug efficacy more quickly and accurately, Kyinno has constructed and identified more than 4,000 engineered cell lines, including overexpressed cell lines constructed through transposon systems or lentivirus infection, gene-edited cell lines constructed through CRISPR-Cas9 technology, and reporter cell lines targeting multiple signaling pathways and membrane receptors. Besides, InnoPanelTM, a panel of over 1000 engineered cell lines was established and characterized to cover a wide range of heavily targeted genes such as CLDN18.1, CLDN18.2, LAG3, OX40, PD-L1, PD-L2, and TIM3. Cell line families were also developed for genes with multiple known driver mutations. All cell lines are annotated with background information, engineering details, functional characterization, and efficacy studies. Furthermore, we developed xenografts for several engineered cell lines and showed that the combination of cell lines and xenografts can accelerate drug development. Additionally, all of this information can be accessed in our free database, InnoPediaTM. The database also offers browsing, searching, and analytical capabilities for over 600 commonly used tumor cell lines and thousands of engineered cell lines with essential genomic and pharmacological data, cell line efficacy data for nearly 2000 common anti-tumor drugs, and comprehensive details for over 100 standard antibodies. Our engineered cell lines are now registered in the online cell line database Cellosaurus, which is available on the ExPASy server. Citation Format: Siyu Li, Chang Liu, Na Wang, Yuqing Hu, Jinying Ning, Feng Hao. InnoPanelTMand InnoPediaTM: resources of engineered cell lines and xenografts for drug discovery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6916.

Abstract 5599: Role of HOX gene expression in differentiation of colon cancer stem cells

Abstract HOX genes encode a highly conserved set of transcription factors critical for stem cell (SC) function and embryonic development. Several HOX genes have also been implicated in a myriad of cancers, including colorectal cancer (CRC). However, how HOX genes play a role in SC regulation and contributes to cancer development is unclear. HOX expression is regulated by WNT, FGF, and retinoic acid (RA) signaling - pathways which also become dysregulated in cancer. Goal: To determine how regulation of HOX genes specifies differentiation of colonic SCs into specialized cell lineages and how dysregulation of HOX genes contributes to CRC development. Hypotheses: i) Each of the different cell types within human colonic epithelium has a distinct HOX gene expression signature; ii) All-trans retinoic acid (ATRA) induced differentiation of CRC cells changes HOX expression that correlates with specific HOX expression signatures in normal colon and CRC cells. Results: Immunostaining shows that specific HOX proteins (e.g., HOXA9 & HOXC9) are selectively expressed in ALDH-positive SCs and expression of these HOX genes is increased in CRC tissues compared to normal epithelium. Bioinformatics analysis predicted that these HOX genes (plus HOXA4, HOXA10, HOXC8) are regulated by RA signaling. Accordingly, we studied how ATRA influences HOX expression in CRC cells (HT29 & SW480). We found ATRA treatment: 1) Decreases proliferation and increases neuroendocrine cell (NEC) differentiation; and 2). Leads to specific changes in HOX gene expression patterns. Using NanoString profiling, we also discovered that LGR5+ SCs, ALDH+ SCs and GLP2R+ NECs have unique HOX signatures. By defining how these HOX gene expression changes in response to ATRA treatment in comparison to the HOX gene signatures of different colonic cell lineages will help us understand the role that HOX genes play in SC differentiation and how dysregulation of HOX gene expression contributes to CRC development. Citation Format: Brian T. Osmond, Caroline O. Facey, Lynn O. Opdenaker, Chi Zhang, Bruce M. Boman. Role of HOX gene expression in differentiation of colon cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5599.

Abstract 663: Irreversible covalent azetidine-based small molecule inhibitors of Stat3 activity block growth of human pancreatic tumors

Abstract The incidence and death rates for pancreatic adenocarcinoma in the US have been increasing by about 1% per year and the death rate has increased by approximately 0.2% yearly. The five-year survival rate has remained below 10% for many years. With surgery, radiation, and chemotherapy being the main treatment options to extend survival or for symptom relief, there is an urgent unmet need for effective new treatment options. Signal Transducer and Activator of Transcription (Stat) 3, one of the Stat family members, is aberrantly activated in human pancreatic and many other cancers. Aberrantly-active Stat3 promotes abnormal tumor-cell intrinsic and extrinsic mechanisms, including dysregulation of gene expression and mitochondria energy metabolism in the tumor cells, and suppression of immune cell functions in the tumor microenvironment. Stat3 is therefore an important target for therapeutic development. Herein we present two small molecules, H182 and H333, which are covalent inhibitors of Stat3 and that potently block Stat3 DNA-binding activity in vitro, with IC50 0.66-0.98 µM. H182 and its structural analog, H333 bind Stat3 via irreversible covalent interactions with key cysteine residues in the Stat3 DNA-binding domain to induce a time-dependent inhibition of Stat3 activity. Both compounds inhibit intracellular constitutive Stat3 tyrosine phosphorylation and induce loss of viable cells and apoptosis in vitro of human pancreatic Panc-1 and Mia-Paca2 cells. H333 is 13-fold more specific and H182 is 4-fold more specific against tumor cells over normal cells. Furthermore, MiaPaca-2 cells treated with H182 and analyzed by Seahorse showed dramatically decreased mitochondria respiration. Notably, xenograft models of MiaPaca2 treated with H182 or H333 via i.p. every other day for 27 days showed dramatic growth inhibition. Collectively, our results identify H182 and H333 as therapeutically-viable small molecules with unique irreversible mechanism of Stat3 inhibition which accounts for their strong antitumor effects against human pancreatic tumor xenografts. Citation Format: Yue Chen, Ning Zhai, Peibin Yue, Christine Brotherton-Pleiss, Wenzhen Fu, Kayo Nakamura, Weiliang Chen, Marcus Tius, Francisco Lopez-Tapia, James Turkson. Irreversible covalent azetidine-based small molecule inhibitors of Stat3 activity block growth of human pancreatic tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 663.

Abstract 3483: SIRT7 as a potential therapeutic target for drug resistance in lung adenocarcinoma: Insights from histone modification-related genes

Abstract Background: Lung cancer is one of the leading causes of cancer-related deaths worldwide. Understanding the molecular mechanisms underlying its development and progression is crucial for the development of targeted therapies. In recent years, histone modification has emerged as a key player in the epigenetic regulation of gene expression, and its involvement in lung cancer has gained significant attention. Histone modifications, including methylation, acetylation, phosphorylation, and ubiquitination, influence chromatin structure and, consequently, gene transcription. Aberrant histone modifications can lead to dysregulated gene expression patterns, contributing to the initiation and progression of lung cancer. In this study, we investigated the expression patterns of 55 histone modification-related genes and identified an epigenetic tumor regulator as a potential therapeutic target. Methods: We obtained 55 histone modification-related genes from dbHiMo (http://hme.riceblast.snu.ac.kr/). Transcriptomic (n= 576), clinical data (n=706) and survival data (n=641) of lung adenocarcinoma (LUAD) were downloaded from XenaTCGA database (https://xenabrowser.net/). The transcriptomic and IC50 values with 87 lung cancer cell lines and 310 drugs were downloaded from DepMap portal (https://depmap.org/portal/). RNA-seq data of GSE197555 was downloaded from GEO database (https://www.ncbi.nlm.nih.gov/geo/). All statistical analysis was performed using R. Results: Among a total of 55 genes related to histone modifications, 6 genes including KAT2A, SIRT7, CARM1, KDM5B, HDAC1 and PRMT3 were significantly overexpressed in tumor tissues in LUAD transcriptome data from TCGA. Out of these 6 genes, 3 (KAT2A, SIRT7 and CARM1) showed significant differences in survival analysis with disease-free interval in the adjuvant therapy-received TCGA LUAD dataset. All three demonstrated that as their expression levels increased, the prognosis became worse. The expression levels of SIRT7 and KAT2A were highly positively correlated with the IC50 value of trametinib, which is MEK inhibitor. Among these two genes, the expression level of SIRT7 was up-regulated in trametinib-treated group in resistance to MEK inhibitor in the H460 cell line. However, sensitive to MEK inhibitor in A549, the SIRT7 expression level was down-regulated in the trametinib-treated group. Conclusion: The histone modification-related gene SIRT7 was found to be associated with resistance to trametinib. In this study, these findings suggest that SIRT7 may serve as a potential therapeutic target related to drug resistance in combination therapy with dabrafenib and trametinib. Citation Format: Kyoung-Ho Pyo, YoungJoon Park, Gang-Taik Lee, Juwon Ahn, Su-Jin Choi, Qi Kejia, Taeku Lee, Youngtaek Kim, Joon Yeon Hwang, Byoung Chul Cho. SIRT7 as a potential therapeutic target for drug resistance in lung adenocarcinoma: Insights from histone modification-related genes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3483.

Can DNA Methylation Profiling Classify Histologic Subtypes and Grades in Soft Tissue Sarcoma?

A clear classification of the subtype and grade of soft tissue sarcoma is important for predicting prognosis and establishing treatment strategies. However, the rarity and heterogeneity of these tumors often make diagnosis difficult. In addition, it remains challenging to predict the response to chemotherapy and prognosis. Thus, we need a new method to help diagnose soft tissue sarcomas and determine treatment strategies in conjunction with traditional methods. Genetic alterations can be found in some subtypes of soft tissue sarcoma, but many other types show dysregulated gene expression attributed to epigenetic changes, such as DNA methylation status. However, research on DNA methylation profiles in soft tissue sarcoma is still insufficient to provide information to assist in diagnosis and therapeutic decisions. (1) Do DNA methylation profiles differ between normal tissue and soft tissue sarcoma? (2) Do DNA methylation profiles vary between different histologic subtypes of soft tissue sarcoma? (3) Do DNA methylation profiles differ based on tumor grade? Between January 2019 and December 2022, we treated 85 patients for soft tissue sarcomas. We considered patients whose specimens were approved for pilot research by the Human Biobank of St. Vincent's Hospital, The Catholic University of Korea, as potentially eligible. Based on this, 41% (35 patients) were eligible; 1% (one patient) was excluded because of gender mismatch between clinical and genetic data after controlling for data quality. Finally, 39 specimens (34 soft tissue sarcomas and five normal samples) were included from 34 patients who had clinical data. All tissue samples were collected intraoperatively. The five normal tissue samples were from muscle tissues. There were 20 female patients and 14 male patients, with a median age of 58 years (range 19 to 82 years). Genomic DNA was extracted from frozen tissue, and DNA methylation profiles were obtained. Genomic annotation of DNA methylation sites and hierarchical cluster analysis were performed to interpret results from DNA methylation profiling. A t-test was used to analyze different methylation probes. Benjamini-Hochberg-adjusted p value calculations were used to account for bias resulting from evaluating thousands of methylation sites. The most common histologic subtypes were liposarcoma (n = 10) and leiomyosarcoma (n = 9). The tumor grade was Fédération Nationale des Centres de Lutte Contre Le Cancer Grades 1, 2, and 3 in 3, 15, and 16 patients, respectively. DNA methylation profiling demonstrated differences between soft tissue sarcoma and normal tissue as 21,188 cytosine-phosphate-guanine sites. Despite the small number of samples, 72 of these sites showed an adjusted p value of < 0.000001, suggesting a low probability of statistical errors. Among the 72 sites, 70 exhibited a hypermethylation pattern in soft tissue sarcoma, with only two sites showing a hypomethylation pattern. Thirty of 34 soft tissue sarcomas were distinguished from normal samples using hierarchical cluster analysis. There was a different methylation pattern between leiomyosarcoma and liposarcoma at 7445 sites. Using the data, hierarchical clustering analysis showed that liposarcoma was distinguished from leiomyosarcoma. When we used the same approach and included other subtypes with three or more samples, only leiomyosarcoma and myxofibrosarcoma were separated from the other subtypes, while liposarcoma and alveolar soft-part sarcoma were mixed with the others. When comparing DNA methylation profiles between low-grade (Grade 1) and high-grade (Grades 2 and 3) soft tissue sarcomas, a difference in methylation pattern was observed at 144 cytosine-phosphate-guanine sites. Among these, 132 cytosine-phosphate-guanine sites exhibited hypermethylation in the high-grade group compared with the low-grade group. Hierarchical clustering analysis showed a division into two groups, with most high-grade sarcomas (28 of 31) separated from the low-grade group and few (3 out of 31) clustered together with the low-grade group. However, three high-grade soft tissue sarcomas were grouped with the Grade 1 cluster, and all of these sarcomas were Grade 2. When comparing Grades 1 and 2 to Grade 3, Grade 3 tumors were separated from Grades 1 and 2. We observed a different DNA methylation pattern between soft tissue sarcomas and normal tissues. Liposarcoma was distinguished from leiomyosarcoma using methylation profiling. High-grade soft tissue sarcoma samples showed a hypermethylation pattern compared with low-grade ones. Our findings indicate the need for research using methylation profiling to better understand the diverse biological characteristics of soft tissue sarcoma. Such research should include studies with sufficient samples and a variety of subtypes, as well as analyses of the expression and function of related genes. Additionally, efforts to link this research with clinical data related to treatment and prognosis are necessary. Level III, diagnostic study.

Abstract 4151: Development of a cancer-activated biologic imaging platform for early lung cancer diagnosis

Abstract Current modalities, such as LDCT and fluorodeoxyglucose positron emission tomography (FDG PET), for early lung cancer imaging, rely upon proxies resulting in poor specificity and/or sensitivity. They are also unreliable for discriminating benign versus malignant lesions resulting in the requirement of longitudinal analyses euphemistically called “watchful waiting”. Lung biopsies are marred by significant false negative rates and pose complications of collapsed lungs or bleeding in up to 22% of procedures and death rates up to 1%. To overcome these obstacles, Earli is developing a non-invasive, highly specific cancer-activated imaging platform that usurps dysregulated gene expression within malignancies to force only cancer cells to produce a synthetic biomarker that can be localized using PET imaging. EARLI-204 is a lipid nanoparticle that contains a DNA nanoplasmid comprised of a cancer-activated promoter driving selective expression of a functionally inactivated somatostatin receptor 2 (SSTR2fi) gene. Abrogation of internalization and signal transduction allows the safe use of SSTR2fi as an ectopically expressed PET reporter gene (PRG). Following administration, EARLI-204 transfects tumor and normal cells but transcriptional activation only within cancer cells results in selective cell-surface expression of SSTR2fi that can be imaged with FDA-approved SSTR2 PET tracers. H1299 human lung cancer cells engineered to express SSTR2 (H1299-SSTR2) revealed a discernable PET signal with as little as 31,000 engineered cells. Mixed cell titration studies using subcutaneous (SQ) tumors with H1299-SSTR2 and non-expressing H1299-wt cells suggest tumors with between 0.1% and 1% H1299-SSTR2 cells had a significant PET signal, compared to tumors with 100% H1299-wt. This result sets a benchmark transfection of ~1% to achieve a PET signal. Intratumoral (IT) dose titration of EARLI-204 revealed that 5 ug of EARLI-204 generates a significant PET signal. Consistent with the H1299-SSTR2 studies, IHC shows ~1% of tumor cells express the PRG at a 5 ug IT dose level. Furthermore, we measured 70 copies of EARLI-204 DNA per cell resulting in 22,629 SSTR2 mRNA copies/25 ng at a 5 ug IT dose level. IV dosing of EARLI-204 in SQ and intralung tumor models results in cancer-activated expression of SSTR2fi in both SQ and small (&amp;lt;4 mm) lung tumors with significantly increased (p &amp;lt; 0.05) PET signal. For lung tumors, analyses showed 1 copy of EARLI-204 DNA/cell resulting in 780 SSTR2 mRNA copies/25 ng. The results demonstrate an effective molecular imaging platform for drug discovery ranging from in vivo screening to building PK-PD-efficacy relationships and enabling human dose projection for the Earli PET localization drug. The benchmarks and findings established with this preclinical imaging pipeline are currently being evaluated in large animals such as dogs and pigs, and will be translated to humans in planned clinical trials. Citation Format: Mohammed Goryawala, Hung-Yu Henry Lee, Ling Tong, Trupti Patil, Alex Harwig, Chloe Xia, Suthara Ramachandran, Dariusz Wodziak, Dean Felsher, Tim Sproul, David Suhy. Development of a cancer-activated biologic imaging platform for early lung cancer diagnosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4151.

Sparsentan ameliorates glomerular hypercellularity and inflammatory-gene networks induced by IgA1-IgG immune complexes in a mouse model of IgA nephropathy.

IgA nephropathy (IgAN), is characterized by glomerular deposition of immune complexes (IC) consisting of IgA1 with O-glycans deficient in galactose (Gd-IgA1) and Gd-IgA1-specific IgG autoantibodies. These ICs induce kidney injury, and in the absence of disease-specific therapy, up to 40% of IgAN patients progress to kidney failure. IgA1 with its clustered O-glycans is unique to humans, which hampered development of small-animal models of IgAN. Here, we used a model wherein engineered IC (EIC) formed from human Gd-IgA1 and recombinant human IgG autoantibody are injected into nude mice to induce glomerular injury mimicking human IgAN. In this model, we assessed the protective effects of sparsentan, a single-molecule dual endothelin angiotensin receptor antagonist (DEARA) vs. vehicle on EIC-induced glomerular proliferation and dysregulation of gene expression in kidney. Oral administration of sparsentan (60 or 120 mg/kg daily) to mice intravenously injected with EIC attenuated the EIC-induced glomerular hypercellularity. Furthermore, the analysis of changes in the whole kidney transcriptome revealed that key inflammatory and proliferative biological genes and pathways that are upregulated in this EIC model of IgA nephropathy were markedly reduced by sparsentan, including complement genes, integrin components, members of the MAP kinase family, and Fc receptor elements. Partial overlap between mouse and human differentially expressed genes in IgAN further support the translational aspect of the immune and inflammatory component from our transcriptional findings. In conclusion, our data indicate that in the mouse model of IgAN, sparsentan targets immune and inflammatory processes leading to protection from mesangial hypercellularity.

An Association between OXPHOS-Related Gene Expression and Malignant Hyperthermia Susceptibility in Human Skeletal Muscle Biopsies.

Malignant hyperthermia (MH) is a pharmacogenetic condition of skeletal muscle that manifests in hypermetabolic responses upon exposure to volatile anaesthetics. This condition is caused primarily by pathogenic variants in the calcium-release channel RYR1, which disrupts calcium signalling in skeletal muscle. However, our understanding of MH genetics is incomplete, with no variant identified in a significant number of cases and considerable phenotype diversity. In this study, we applied a transcriptomic approach to investigate the genome-wide gene expression in MH-susceptible cases using muscle biopsies taken for diagnostic testing. Baseline comparisons between muscle from MH-susceptible individuals (MHS, n = 8) and non-susceptible controls (MHN, n = 4) identified 822 differentially expressed genes (203 upregulated and 619 downregulated) with significant enrichment in genes associated with oxidative phosphorylation (OXPHOS) and fatty acid metabolism. Investigations of 10 OXPHOS target genes in a larger cohort (MHN: n = 36; MHS: n = 36) validated the reduced expression of ATP5MD and COQ6 in MHS samples, but the remaining 8 selected were not statistically significant. Further analysis also identified evidence of a sex-linked effect in SDHB and UQCC3 expression, and a difference in ATP5MD expression across individuals with MH sub-phenotypes (trigger from in vitro halothane exposure only, MHSh (n = 4); trigger to both in vitro halothane and caffeine exposure, MHShc (n = 4)). Our data support a link between MH-susceptibility and dysregulated gene expression associated with mitochondrial bioenergetics, which we speculate plays a role in the phenotypic variability observed within MH.

Virus-induced host genomic remodeling dysregulates gene expression, triggering tumorigenesis.

Virus-induced genomic remodeling and altered gene expression contribute significantly to cancer development. Some oncogenic viruses such as Human papillomavirus (HPV) specifically trigger certain cancers by integrating into the host's DNA, disrupting gene regulation linked to cell growth and migration. The effect can be through direct integration of viral genomes into the host genome or through indirect modulation of host cell pathways/proteins by viral proteins. Viral proteins also disrupt key cellular processes like apoptosis and DNA repair by interacting with host molecules, affecting signaling pathways. These disruptions lead to mutation accumulation and tumorigenesis. This review focuses on recent studies exploring virus-mediated genomic structure, altered gene expression, and epigenetic modifications in tumorigenesis.

Type I interferon signaling, cognition and neurodegeneration following COVID-19: update on a mechanistic pathogenetic model with implications for Alzheimer's disease.

COVID-19's effects on the human brain reveal a multifactorial impact on cognition and the potential to inflict lasting neuronal damage. Type I interferon signaling, a pathway that represents our defense against pathogens, is primarily affected by COVID-19. Type I interferon signaling, however, is known to mediate cognitive dysfunction upon its dysregulation following synaptopathy, microgliosis and neuronal damage. In previous studies, we proposed a model of outside-in dysregulation of tonic IFN-I signaling in the brain following a COVID-19. This disruption would be mediated by the crosstalk between central and peripheral immunity, and could potentially establish feed-forward IFN-I dysregulation leading to neuroinflammation and potentially, neurodegeneration. We proposed that for the CNS, the second-order mediators would be intrinsic disease-associated molecular patterns (DAMPs) such as proteopathic seeds, without the requirement of neuroinvasion to sustain inflammation. Selective vulnerability of neurogenesis sites to IFN-I dysregulation would then lead to clinical manifestations such as anosmia and cognitive impairment. Since the inception of our model at the beginning of the pandemic, a growing body of studies has provided further evidence for the effects of SARS-CoV-2 infection on the human CNS and cognition. Several preclinical and clinical studies have displayed IFN-I dysregulation and tauopathy in gene expression and neuropathological data in new cases, correspondingly. Furthermore, neurodegeneration identified with a predilection for the extended olfactory network furthermore supports the neuroanatomical concept of our model, and its independence from fulminant neuroinvasion and encephalitis as a cause of CNS damage. In this perspective, we summarize the data on IFN-I as a plausible mechanism of cognitive impairment in this setting, and its potential contribution to Alzheimer's disease and its interplay with COVID-19.

B-cell intrinsic regulation of antibody mediated immunity by histone H2A deubiquitinase BAP1.

BAP1 is a deubiquitinase (DUB) of the Ubiquitin C-terminal Hydrolase (UCH) family that regulates gene expression and other cellular processes, through its direct catalytic activity on the repressive epigenetic mark histone H2AK119ub, as well as on several other substrates. BAP1 is also a highly important tumor suppressor, expressed and functional across many cell types and tissues. In recent work, we demonstrated a cell intrinsic role of BAP1 in the B cell lineage development in murine bone marrow, however the role of BAP1 in the regulation of B cell mediated humoral immune response has not been previously explored. In the current study, we demonstrate that a B-cell intrinsic loss of BAP1 in activated B cells in the Bap1 fl/fl Cγ1-cre murine model results in a severe defect in antibody production, with altered dynamics of germinal centre B cell, memory B cell, and plasma cell numbers. At the cellular and molecular level, BAP1 was dispensable for B cell immunoglobulin class switching but resulted in an impaired proliferation of activated B cells, with genome-wide dysregulation in histone H2AK119ub levels and gene expression. In summary, our study establishes the B-cell intrinsic role of BAP1 in antibody mediated immune response and indicates its central role in the regulation of the genome-wide landscapes of histone H2AK119ub and downstream transcriptional programs of B cell activation and humoral immunity.

Methylation changes of liver DNA during the formation of gallstones.

Aim: To explore the overall methylation changes in liver tissues during the formation of gallstones, as well as the key pathways and genes involved in the process. Methods: Reduced-representation bisulfite sequencing and RNA sequencing were conducted on the liver tissues of mice with gallstones and control normal mice. Results: A total of 8705 differentially methylated regions in CpG and 1410 differentially expressed genes were identified. The joint analysis indicated that aberrant DNA methylation may be associated with dysregulated gene expression in key pathways such as cholesterol metabolism and bile secretion. Conclusion: We propose for the first time that methylation changes in some key pathway genes in liver tissue may be involved in the formation of gallstones.

Prodromal Parkinson disease signs are predicted by a whole-blood inflammatory transcriptional signature in young Pink1−/− rats

BackgroundParkinson disease (PD) is the fastest growing neurodegenerative disease. The molecular pathology of PD in the prodromal phase is poorly understood; as such, there are no specific prognostic or diagnostic tests. A validated Pink1 genetic knockout rat was used to model early-onset and progressive PD. Male Pink1−/− rats exhibit progressive declines in ultrasonic vocalizations as well as hindlimb and forelimb motor deficits by mid-to-late adulthood. Previous RNA-sequencing work identified upregulation of genes involved in disease pathways and inflammation within the brainstem and vocal fold muscle. The purpose of this study was to identify gene pathways within the whole blood of young Pink1−/− rats (3 months of age) and to link gene expression to early acoustical changes. To accomplish this, limb motor testing (open field and cylinder tests) and ultrasonic vocalization data were collected, immediately followed by the collection of whole blood and RNA extraction. Illumina® Total RNA-Seq TruSeq platform was used to profile differential expression of genes. Statistically significant genes were identified and Weighted Gene Co-expression Network Analysis was used to construct co-expression networks and modules from the whole blood gene expression dataset as well as the open field, cylinder, and USV acoustical dataset. ENRICHR was used to identify the top up-regulated biological pathways.ResultsThe data suggest that inflammation and interferon signaling upregulation in the whole blood is present during early PD. We also identified genes involved in the dysregulation of ribosomal protein and RNA processing gene expression as well as prion protein gene expression.ConclusionsThese data identified several potential blood biomarkers and pathways that may be linked to anxiety and vocalization acoustic parameters and are key candidates for future drug-repurposing work and comparison to human datasets.