cDNA Tissue Research Articles

Identification and antibacterial activity of a novel phage-type lysozyme from the freshwater mussel Hyriopsis cumingii

A cDNA encoding a phage-type lysozyme, designated as HcPLYZ, was successfully cloned from Hyriopsis cumingii. The full-length cDNA sequence of HcPLYZ was determined to be 896 base pairs in length. Analysis revealed the absence of a signal peptide at its N-terminus, and identified two highly conserved phage-type lysozyme activity sites, Glu20 and Asp29, within the deduced amino acid sequence of HcPLYZ. The results of the cloning and sequencing symbiotic bacteria in tissues were consistent with those obtained using tissue cDNA as the template, suggesting that HcPLYZ may originate a symbiotic bacterium. The expression levels of HcPLYZ mRNA exhibited significant variations across different tissues. Successful expression was induced using IPTG, and the native recombinant protein was subsequently purified through affinity chromatography employing Ni2+, and the optimal pH and temperature of which were determined to be 5.5 and 50 °C, respectively. Following exposure to Aeromonas hydrophila, there was a significant increase in the levels of HcPLYZ mRNA in the hemocytes, hepatopancreas, and gills. HcPLYZ was demonstrated the inhibition activity of 55% and 83% against Micrococcus lysodeikticus under pH 5.5 and 50 °C conditions, respectively. These results suggested that HcPLYZ possessed antibacterial activity against both A. hydrophila and M. lysodeikticus.

Differential expression of NAT1 pharmacogene in hormone receptor positive vs. negative female breast tumors may affect drug treatment.

Studies have reported overexpression of NAT1 gene for xenobiotic metabolizing arylamine N -acetyltransferase type 1 in estrogen receptor positive breast tumors, and this association has been linked to patient chemoresistance and response to tamoxifen. We probed the expression of NAT1 , using quantitative reverse transcription PCR to screen clinically characterized breast cancer tissue cDNA arrays. Primers detecting all NAT1 alternative transcripts were used, and the protocol and results are reported according to consensus guidelines. The clinical information about 166 tumor samples screened is provided, including tumor stage, estrogen and progesterone receptor status and HER2 expression. NAT1 was found to be significantly ( P < 0.001) upregulated in hormone receptor positive vs. negative tumors. No correlation was apparent between NAT1 and tumor stage or HER2 expression. Our findings demonstrate a strong correlation between the expression of NAT1 and steroid hormone receptors in breast tumors, supporting its possible utility as a pharmacogenetic biomarker or drug target. Of the two polymorphic NAT genes, NAT1 is the one primarily expressed in breast tissue, and is subjected to regulation by two differential promoters and more than one polyadenylation signal. Hormonal factors may enhance NAT1 gene expression at the transcriptional or epigenetic level, and tamoxifen has additionally been shown to inhibit NAT1 enzymatic activity. The outcome of tamoxifen treatment is also more favorable in patients with NAT1 overexpressing tumors. The study adds to the growing body of evidence implicating NAT1 in breast cancer and its pharmacological treatment.

PLAG1 interacts with GPX4 to conquer vulnerability to sorafenib induced ferroptosis through a PVT1/miR-195-5p axis-dependent manner in hepatocellular carcinoma

BackgroundSorafenib is a standard first-line treatment for advanced hepatocellular carcinoma (HCC), yet its effectiveness is often constrained. Emerging studies reveal that sorafenib triggers ferroptosis, an iron-dependent regulated cell death (RCD) mechanism characterized by lipid peroxidation. Our findings isolate the principal target responsible for ferroptosis in HCC cells and outline an approach to potentially augment sorafenib's therapeutic impact on HCC.MethodsWe investigated the gene expression alterations following sgRNA-mediated knockdown induced by erastin and sorafenib in HCC cells using CRISPR screening-based bioinformatics analysis. Gene set enrichment analysis (GSEA) and the "GDCRNATools" package facilitated the correlation studies. We employed tissue microarrays and cDNA microarrays for validation. Ubiquitination assay, Chromatin immunoprecipitation (ChIP) assay, RNA immunoprecipitation (RIP) assay, and dual-luciferase reporter assay were utilized to delineate the specific mechanisms underlying ferroptosis in HCC cells.ResultsOur study has revealed that pleiomorphic adenoma gene 1 (PLAG1), a gene implicated in pleomorphic adenoma, confers resistance to ferroptosis in HCC cells treated with sorafenib. Sorafenib leads to the opposite trend of protein and mRNA levels of PLAG1, which is not caused by affecting the stability or ubiquitination of PLAG1 protein, but by the regulation of PLAG1 at the transcriptional level by its upstream competitive endogenous long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1). Data from 139 HCC patients showed a significant positive correlation between PLAG1 and GPX4 levels in tumor samples, and PLAG1 is instrumental in redox homeostasis by driving the expression of glutathione peroxidase 4 (GPX4), the enzyme that reduces lipid peroxides (LPOs), which further leads to ferroptosis inhibition.ConclusionsFerroptosis is a promising target for cancer therapy, especially for patients resistant to standard chemotherapy or immunotherapy. Our findings indicate that PLAG1 holds therapeutic promise and may enhance the efficacy of sorafenib in treating HCC.

Genotoxic Effects of Cassava Effluent on the Expression of Selected Genes in the African Catfish, Clarias gariepinus

Aim: A cause for worry is the wastewater that is released into the environment or public sewers without any sort of purpose during the processing of Manihot esculenta Crantz. Fish and other aquatic species may suffer negative consequences if wastewater is discharged into streams and rivers, either directly or indirectly. This study was conducted to examine the effects of cassava effluents on gene expression in the African catfish (Clarias gariepinus). Methodology: C. gariepinus juveniles were exposed to 0.1, 0.5, 1.0 and 1.5 % concentrations of cassava effluent, respectively. The subsequent tissue extraction, RNA isolation, cDNA synthesis and electrophoresis analysis were all done following standard procedures. Results: From the results obtained, there were varying levels of upregulation in the expression levels of all the nine genes assessed: IL-1β, CYPIIA, HSP70, DMRTI, HSD17B, FOX12, MEL1C, CAMKIIg and GH genes. Statistical analysis to compare the expression levels of the genes at the different concentrations with their corresponding control experiments showed that the upregulation of only two genes, (HSD17B and GH), upon exposure to cassava effluents were not significant (p &gt;0.05) at any concentration. The upregulation of the seven other genes is an indication that the cassava effluents exerted adverse impacts on the physiology of C. gariepinus. Conclusion: It is therefore recommended that cassava effluents be properly treated before being discharged into the aquatic environment.

Validation of Blunting of Inflammatory Markers in LPS Induced Tissue with SPM Treatment

Background and Hypothesis: Chronic rhinosinusitis (CRS) is defined as persistent inflammation of the mucosa of the nose and paranasal sinuses, either with or without nasal polyps. The pathophysiology of CRS is thought to occur due to a dysfunction of the immune response leading to prolonged NF-kB signaling. Many chronic diseases like CRS have been shown to have chronic NF-kB dysregulation. One hypothesis for the persistent inflammation seen in CRS patients is that they have a less robust pro-resolution response that aids in termination of the NF-kB pathway. In this study, we sought to validate our previous results from nasal polyp tissue using qPCR for key inflammatory mediators, CXCL1, CSF3, and myd88.&#x0D; Methods: Human CRS nasal polyp tissue was collected during functional endoscopic sinus surgery to be grown in cell culture. The nasal polyp tissue was grown in 10 ug/ml of LPS to mimic gram-negative conditions commonly seen in CRS. Tissue cDNA was extracted and frozen at – 80° C. Tissue cDNA for control, RvD2, LPS, and LPS+RvD2 was thawed and used to run qPCR for myd88, CXCL1, and CSF3.&#x0D; Results: qPCR data was normalized using GAPDH and B-actin. When normalized with GAPDH and B-actin, CSF3 was found to be downregulated with RvD2 exposure, while both myd88 and CXCL1 showed inconsistent results. Downregulation of CSF3 with RvD2 exposure, is consistentwith our hypothesis that RvD2 plays a role in NF-kB resolution.&#x0D; Conclusion: Downregulation of the NF-kB pathway can play an important role in reducing the chronic inflammation seen in CRS. CSF3 was one gene target of the NF-kB pathway that was continuously found to be downregulated when nasal polyp tissue was treated with RvD2. Ourfindings demonstrate that when nasal polyp tissue is treated with pro-resolving mediators such as RvD2, at least one or more of the NF-kB-associated genes are downregulated.

Low Expression of A3C and PLP2 Indicating a Favorable Prognosis in Human Gliomas.

The roles of apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3C (A3C) in various human malignancies are not consistent. A3C expression is correlated with early-stage breast cancer and is presented as a good prognostic factor; however, it induces fewer therapeutic effects of cytotoxic drugs in low-grade gliomas. To explore the impact of A3C on gliomas, a statistical analysis of several public databases was conducted. The results showed that enhanced A3C expression was associated with advanced tumor grades and poor expression of prognostic factors. Similarly, our in vitro study revealed that glioblastoma (GBM) cell lines had higher A3C mRNA and protein expression than that of normal brain tissue cDNA and lysates. We first performed an immunohistochemical stain (IHC) to prove that gliomas with high A3C expression presented the wild type-Isocitrate dehydrogenase 1 (IDH1), and they had an unfavorable prognosis in human glioma tissues. In addition, the oncological factors associated with A3C expression suggested that DNA repair pathways are important mechanisms for inducing tumorigenesis and chemoresistance in gliomas. Moreover, a significant correlation was observed between A3C expression and proteolipid protein 2 (PLP2). Reactive oxygen species (ROS) -activated PLP2 prevents DNA damage-induced cell apoptosis. Compared to high immunostaining scores for A3C and/or PLP2 expression, combined low immunostaining scores for A3C and PLP2 correlated with improved survival in gliomas; however, the detailed mechanism is to be elucidated. In conclusion, our results not only confirmed A3C played an important role in glioma development, but the A3C IHC test could successfully predict the therapeutic effects and disease prognosis.

TIG1 Inhibits the mTOR Signaling Pathway in Malignant Melanoma Through the VAC14 Protein.

Currently, there are few drug options available to treat malignant melanoma. Tazarotene-inducible gene 1 (TIG1) was originally isolated from skin tissue, but its function in skin tissue has not been clarified. The aim of this study was to elucidate the effect of TIG1 and mTOR signaling pathways associated with VAC14 on melanoma. The expression of TIG1 and VAC14 in melanoma tissue was analyzed using a melanoma tissue cDNA array. The interaction between TIG1 and VAC14 was analyzed using immunoprecipitation and immunostaining. Western blot was used to investigate the molecular targets of TIG1 and VAC14 in melanoma cells. TIG1 was highly expressed in normal skin tissue but was low in malignant melanoma, while VAC14 showed the opposite trend. TIG1 inhibited insulin-induced cell proliferation and insulin-activated mammalian target of rapamycin complex 1 (mTORC1)-p70 S6 kinase but did not affect the level of phospho-AKT in A2058 melanoma cells. This suggests that the main target of TIG1 regulating cell growth is phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2] rather than the PI(4,5)P2 signaling pathway. Additional TIG1 showed no additive effect on the inhibition of mTOR signaling in the absence of VAC14 expression, suggesting that TIG1 inhibited the activation of mTOR mainly by inhibiting VAC14. TIG1 may play an important role in preventing malignant melanoma through retinoic acid via VAC14.

Expression Level of lncRNA CYTOR in Iranian Cervical Cancer Patients.

A critical role has been known for lncRNAs in the initiation and development of cancers. Therefore, lncRNAs have been reported as the possible biomarkers in relation to the diagnosis and therapy of malignancies. This project examined the change in CYTOR lncRNA expression in human cervical cancer samples as compared with adjacent healthy ones. We provided one hundred fifteen pairs of tumorous and adjacent healthy tissue specimens of cervical cancer patients. RNAs were isolated from tissue specimens and cDNAs were synthesized. We considered quantitative Real-time PCR (qRT-PCR) to examine the expression levels of CYTOR lncRNA. In addition, the biomarker activity of CYTOR and the associations between the lncRNA and clinicopathological characteristics were evaluated. The significant increased expression of CYTOR was obtained in cancerous samples as compared with non-cancerous ones (P< 0.0001). A significant correlation was indicated between CYTOR expression and the squamous subtype of cervical cancer (p=0.046). The receiver operating characteristic (ROC) curve-related AUC (area under the curve), specificity, and sensitivity were calculated 0.88, 81.74%, and 80%, respectively, which may introduce CYTOR as a potential biomarker. CYTOR may be an effective oncogene and biomarker in cervical cancer cases given its increased expression in human cervical cancer tissues.

Molecular biomarkers for oxidative stress and neuronal damage in red-bellied pacu (Piaractus brachypomus)

Biomarkers are biological molecules that provide information about the physiological condition of an organism such as early signals of health deterioration. The aim of this study was to compare the relative gene expression of four molecular biomarkers related to oxidative stress, and neuronal damage in Piaractus brachypomus under three different conditions (exposure to chlorpyrifos (CPF), menthol and eugenol anesthesia, and brain injury). Bioinformatic analyses were conducted to design primers for the molecular biomarkers, then, the relative gene expression of COX1, GPX1, BDNF and CALB1 genes was measured by qPCR using brain tissue cDNA from the treated animals as template and 2-ΔΔCT method was performed. EF1a gene was used as reference gene. The results showed a response to chemical stress in the CPF treatment samples where GPX1, BDNF and CALB1 genes were up-regulated. Finally, in menthol/eugenol and brain injury treatments, no alterations in the relative gene expression were observed.

Improving gene expression analysis efficacy from formalin-fixed paraffin embedded tissues.

Improving RNA isolation and cDNA synthesis techniques has emerged due to advancements in the knowledge of molecular basis of most diseases. This in turn increased the need of higher quantity and quality of the extracted genetic material to be used for a variety of diagnostic tests and experiments. The aim of the study was to compare three modified methods for RNA extraction from formalin-fixed paraffin embedded (FFPE) biopsied tissue and different cDNA synthesis strategies to facilitate study of gene expression. Compared RNA extraction methods were: lysis buffer, phenol-based extraction, and combination of both with concomitant use of silica-based spin columns. RNA quantity and purity were estimated spectrophotometrically. Different priming strategies for cDNA synthesis were applied: oligodT, combination of oligodT and random hexamer, and gene specific primer. Two-step RT-qPCR of ribosomal protein L37A on preamplified and non-preamplified cDNA templates was performed. The combination of lysis buffer with phenol based extraction gave higher RNA yield. By doing cDNA preamplification, the confidence of detection by qPCR was raised, and efficiency was improved. The preamplified template increased the sensitivity of analysis. Together, the combination of approaches improved substantially the reproducibility and validity of quantitative gene expression analyses from FFPE tissues.

Abstract 1414: Assessment of the Cancer Testis antigen AKAP4, via tumor expression analysis and IHC, as a potential vaccine and immunotherapy target for colorectal cancer

Abstract Introduction: Cancer-Testis antigens (CTA’s) are normally expressed in germline tissue, however, aberrant expression occurs in some cancers. Restricted CTA expression in normal tissues make CTA’s potential vaccine targets. CTA’s have been associated with tumor cell proliferation and invasion. The CTA A-kinase anchor proteins 4 (AKAP 4) plays a role in cancer development and progression. The expression pattern of AKAP4 gene in CRC is not well characterized. This study’s aim was to assess AKAP4 expression in CRC and to assess this CTA’s potential as a vaccine target. Methods: CRC patients (pts) undergoing surgery who donated tissue to an IRB approved tissue/data bank comprise the study group. Demographic and pathologic data were assessed. Tissues were OCT embedded and stored at -800C. Total purified RNA was isolated from tissue samples and cDNA synthesized. AKAP4 expression was analyzed by quantitative PCR (QPCR) using EXPRESS qPCR universal Supermix and Taqman assay. Comparative quantitative analysis was performed based on the delta-delta Ct method with GAPDH as internal control. Tumor and testis AKAP4 expression levels were determined; tumors with levels 0.1% or more than the testis was considered positive. Immunohistochemistry (IHC) was performed on a subset of tumor and normal tissue. The impact of tumor location and cancer stage on AKAP4 expression was determined and assessed (Wilcoxon signed rank test). Results: 70 paired CRC and normal tissue specimens (35 M/36 F, age 67.8±14) were studied (86% colon,14% rectal; cancer stage: 1, 24%; 2,37%; 3, 31.%;stg 4, 7%). The percent of pts with a relative Malignant to Normal tissue AKAP4 expression ratio (MN) over 1 was 17%; the percent with both MN ratio over 1 and expression levels above 0.1% of testis levels was 16%. IHC demonstrated AKAP4 in a subset of CRC tumor samples. No significant difference was noted between colon vs rectal, or cancer stage groups. No expression was found in 21 normal samples. Discussion: In a tumor subset the relative expression of AKAP4 was above that of normal colon and more than 0.1% of testis expression. IHC study demonstrated the antigen in CRC tumors. A larger study is needed determine if AKAP4 expression correlates with T, N, or final tumor stage. AKAP4 holds some promise as a vaccine target. Citation Format: Chandana S. K. Herath Mudiyanselage, Neil Mitra, Otavia L. Caballero, Dasuni N. Gamage, Xiaohong Yan, Vesna Cekic, Joseph Martz, Richard L. Whelan. Assessment of the Cancer Testis antigen AKAP4, via tumor expression analysis and IHC, as a potential vaccine and immunotherapy target for colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1414.

Biologic characterization of ABCA3 variants in lung tissue from infants and children with ABCA3 deficiency.

ABCA3 is a phospholipid transporter protein required for surfactant assembly in lamellar bodies of alveolar type II cells. Biallelic pathogenic ABCA3 variants cause severe neonatal respiratory distress syndrome or childhood interstitial lung disease. However, ABCA3 genotype alone does not explain the diversity in disease presentation, severity, and progression. Additionally, monoallelic ABCA3 variants have been reported in infants and children with ABCA3-deficient phenotypes. The effects of most ABCA3 variants identified in patients have not been characterized at the RNA level. ABCA3 allele-specific expression occurs in some cell types due to epigenetic regulation. We obtained lung tissue at transplant or autopsy from 16 infants and children with ABCA3 deficiency due to compound heterozygous ABCA3 variants for biologic characterization of the predicted effects of ABCA3 variants at the RNA level and determination of ABCA3 allele expression. We extracted DNA and RNA from frozen lung tissue and reverse-transcribed cDNA from mRNA. We performed Sanger sequencing to assess allele-specific expression by comparing the heights of variant nucleotide peaks in amplicons from genomic DNA and cDNA. We found similar genomic and cDNA variant nucleotide peak heights and no evidence of allele-specific expression among explant or autopsy samples with biallelic missense ABCA3 variants (n = 6). We observed allele-specific expression of missense alleles in trans with frameshift (n = 4) or nonsense (n = 1) variants, attributable to nonsense-mediated decay. The missense variant c.53 A > G;p.Gln18Arg, located near an exon-intron junction, encoded abnormal splicing with skipping of exon 4. Biologic characterization of ABCA3 variants can inform discovery of variant-specific disease mechanisms.

Development and Validation of a Prognostic Gene Signature Correlated With M2 Macrophage Infiltration in Esophageal Squamous Cell Carcinoma.

BackgroundEsophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer and the seventh most prevalent cause of cancer-related death worldwide. Tumor microenvironment (TME) has been confirmed to play an crucial role in ESCC progression, prognosis, and the response to immunotherapy. There is a need for predictive biomarkers of TME-related processes to better prognosticate ESCC outcomes.AimTo identify a novel gene signature linked with the TME to predict the prognosis of ESCC.MethodsWe calculated the immune/stromal scores of 95 ESCC samples from The Cancer Genome Atlas (TCGA) using the ESTIMATE algorithm, and identified differentially expressed genes (DEGs) between high and low immune/stromal score patients. The key prognostic genes were further analyzed by the intersection of protein–protein interaction (PPI) networks and univariate Cox regression analysis. Finally, a risk score model was constructed using multivariate Cox regression analysis. We evaluated the associations between the risk score model and immune infiltration via the CIBERSORT algorithm. Moreover, we validated the signature using the Gene Expression Omnibus (GEO) database. Within the ten gene signature, five rarely reported genes were further validated with quantitative real time polymerase chain reaction (qRT-PCR) using an ESCC tissue cDNA microarray.ResultsA total of 133 up-regulated genes were identified as DEGs. Ten prognostic genes were selected based on intersection analysis of univariate COX regression analysis and PPI, and consisted of C1QA, C1QB, C1QC, CD86, C3AR1, CSF1R, ITGB2, LCP2, SPI1, and TYROBP (HR>1, p<0.05). The expression of 9 of these genes in the tumor samples were significantly higher compared to matched adjacent normal tissue based on the GEO database (p<0.05). Next, we assessed the ability of the ten-gene signature to predict the overall survival of ESCC patients, and found that the high-risk group had significantly poorer outcomes compared to the low-risk group using univariate and multivariate analyses in the TCGA and GEO cohorts (HR=2.104, 95% confidence interval:1.343-3.295, p=0.001; HR=1.6915, 95% confidence interval:1.053-2.717, p=0.0297). Additionally, receiver operating characteristic (ROC) curve analysis demonstrated a relatively sensitive and specific profile for the signature (1-, 2-, 3-year AUC=0.672, 0.854, 0.81). To identify the basis for these differences in the TME, we performed correlation analyses and found a significant positive correlation with M1 and M2 macrophages and CD8+ T cells, as well as a strong correlation to M2 macrophage surface markers. A nomogram based on the risk score and select clinicopathologic characteristics was constructed to predict overall survival of ESCC patients. For validation, qRT-PCR of an ESCC patient cDNA microarray was performed, and demonstrated that C1QA, C3AR1, LCP2, SPI1, and TYROBP were up-regulated in tumor samples and predict poor prognosis.ConclusionThis study established and validated a novel 10-gene signature linked with M2 macrophages and poor prognosis in ESCC patients. Importantly, we identified C1QA, C3AR1, LCP2, SPI1, and TYROBP as novel M2 macrophage-correlated survival biomarkers. These findings may identify potential targets for therapy in ESCC patients.

Investigating Differential Expression of mTOR1/UCA1 in Tumor Samples of Colorectal Cancer Compared with Tumor Marginal Samples

Background: Colorectal cancer (CRC) is the second and third most common cancer in men and women respectively, and the fourth cause of cancer death of individuals. Mutations in specific genes can lead to colorectal cancer. UCA1 is one of the oncogenic genes that have been shown to stimulate cell proliferation. mTOR1 is another gene that leads to the growth of cancer cells through anabolic processes and autophagy inhibition. Objectives: In this study, we evaluate the expression of these two genes in different phases of CRC, that helps the early detection of colorectal cancer which can increase the survival rate. Methods: First, we collected 25 colorectal cancer tumor tissues and 25 adjacent normal tissues as a control group. Then, RNA was extracted from tissue samples and cDNA synthesized. The UCA1 and mTOR1 expression was evaluated in CRC tissues compared to adjacent normal tissues by Real Time PCR. Results: Our results showed that the UCA1 and mTOR1 expression in the tumor tissues was significantly higher than in the adjacent normal tissues (P &lt; 0.05). There was also a significant difference in Lynph inv and Vescu inv with mTOR1 expression (P &lt; 0.05). Conclusions: Our results showed that UCA1/mTOR1 may be important genes involved in colorectal cancer. mTOR1 was also identified as one of the possible genes in metastasis of colorectal cancer. Thus, UCA1 and mTOR1 can probably be considered as biomarkers in CRC therapy and diagnosis.

Abstract 103: Spatially resolved transcriptomics identified distinct tumor-stroma crosstalk networks in long term ovarian cancer survivors

Abstract The tumor microenvironment (TME), composed primarily of fibroblasts, endothelial cells, lymphocytic infiltrates and extracellular matrix proteins, can directly affect cancer cell growth, migration, differentiation as well as immune cell landscapes, thereby presenting a unique aspect of diagnosing and treating cancer. Cancer-associated fibroblasts (CAF) and immune cells are the main orchestrators of the ovarian cancer TME. We hypothesized that spatial transcriptomics (ST), which can provide a rich spatial context to gene expression, will identify crosstalk signaling networks among various cell types in the ovarian TME. Advanced stage high-grade serous ovarian cancer (HGSC) tissue frozen sections from two treatment naïve long-term survivors (LTS, overall survival ≥ 10 years) and two short-term survivors (STS, overall survival ≤ 2 years) were placed onto a ST expression slide pre-spotted with 1000 unique barcoded RNA-capturing probes. The ST slides were then stained with H&amp;E and imaged. Tissue permeabilization and cDNA synthesis were then performed directly on the tissue section. The derived barcoded cDNA libraries from each sample were sequenced using Illumina NextSeq500 flow cells. After RNA-Seq analysis, supervised analysis was then performed by selecting different regions (based on tissue histology) in the tumor, tumor/stroma mixture, stroma close or far away from tumor areas to identify differentially expressed genes between STS and LTS. Stromal cells from different spatial locations had unique differentially expressed genes based on their proximity (11 genes in LTS; 11 genes in STS) or remoteness (18 genes in LTS; 10 genes in STS) to cancer cell compartments. Among the major modulated gene networks, higher levels of antigen-presenting molecules were found in the stroma in close proximity to the tumor cell nest than in stroma located far away in LTS tumor samples but not in the STS samples, suggesting an increased number of activated antigen-presenting cells in LTS tumors. In addition, higher levels of adhesion molecules and angiogenetic factors were found in the stroma in close proximity to the tumor cell nest than in stroma located far away in STS tumor samples but not in LTS samples, suggesting that adhesion molecules and angiogenetic factors produced by stromal cells may facilitate the invasiveness of the tumor cells, which subsequently leads to short term survival in patients with the disease. Our findings demonstrate for the first time that spatially resolved transcriptomics allows the identification of prognostic biomarkers associated with overall survival in HGSC patients. Further studies using deconvoluted ST data to further delineate the specific stromal cell subtypes in close proximity to tumors, and imaging mass cytometry (IMC) or multiplexed immunohistochemistry to validate the protein expression of the potential biomarkers are ongoing. Citation Format: Sammy Ferri-Borgogno, Jianting Sheng, Ying Zhu, Kwong K. Wong, Stephen T. Wong, Samuel C. Mok. Spatially resolved transcriptomics identified distinct tumor-stroma crosstalk networks in long term ovarian cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 103.

A stealth antigen SPESP1, which is epigenetically silenced in tumors, is a suitable target for cancer immunotherapy.

Recent studies have revealed that tumor cells decrease their immunogenicity by epigenetically repressing the expression of highly immunogenic antigens to survive in immunocompetent hosts. We hypothesized that these epigenetically hidden “stealth” antigens should be favorable targets for cancer immunotherapy due to their high immunogenicity. To identify these stealth antigens, we treated human lung cell line A549 with DNA methyltransferase inhibitor 5‐aza‐2′‐deoxycytidine (5Aza) and its prodrug guadecitabine for 3 d in vitro and screened it using cDNA microarray analysis. We found that the gene encoding sperm equatorial segment protein 1 (SPESP1) was re‐expressed in cell lines including solid tumors and leukemias treated with 5Aza, although SPESP1 was not detected in untreated tumor cell lines. Using normal human tissue cDNA panels, we demonstrated that SPESP1 was not detected in normal human tissue except for testis and placenta. Moreover, we found using immunohistochemistry SPESP1 re‐expression in xenografts in BALB/c‐nu/nu mice that received 5Aza treatment. To assess the antigenicity of SPESP1, we stimulated human CD4+ T‐cells with a SPESP1‐derived peptide designed using a computer algorithm. After repetitive stimulation, SPESP1‐specific helper T‐cells were obtained; these cells produced interferon‐γ against HLA‐matched tumor cell lines treated with 5Aza. We also detected SPESP1 expression in freshly collected tumor cells derived from patients with acute myeloid leukemia or lung cancer. In conclusion, SPESP1 can be classified as a stealth antigen, a molecule encoded by a gene that is epigenetically silenced in tumor cells but serves as a highly immunogenic antigen suitable for cancer immunotherapy.

Targeting the vasopressin type-2 receptor for renal cell carcinoma therapy.

Arginine vasopressin (AVP) and its type-2 receptor (V2R) play an essential role in the regulation of salt and water homeostasis by the kidneys. V2R activation also stimulates proliferation of renal cell carcinoma (RCC) cell lines in vitro. The current studies investigated V2R expression and activity in human RCC tumors, and its role in RCC tumor growth. Examination of the cancer genome atlas (TCGA) database, and analysis of human RCC tumor tissue microarrays, cDNA arrays and tumor biopsy samples demonstrated V2R expression and activity in clear cell RCC (ccRCC). In vitro, V2R antagonists OPC31260 and Tolvaptan, or V2R gene silencing reduced wound closure and cell viability of 786-O and Caki-1 human ccRCC cell lines. Similarly in mouse xenograft models, Tolvaptan and OPC31260 decreased RCC tumor growth by reducing cell proliferation and angiogenesis, while increasing apoptosis. In contrast, the V2R agonist dDAVP significantly increased tumor growth. High intracellular cAMP levels and ERK1/2 activation were observed in human ccRCC tumors. In mouse tumors and Caki-1 cells, V2R agonists reduced cAMP and ERK1/2 activation, while dDAVP treatment had the reverse effect. V2R gene silencing in Caki-1 cells also reduced cAMP and ERK1/2 activation. These results provide novel evidence for a pathogenic role of V2R signaling in ccRCC, and suggest that inhibitors of the AVP-V2R pathway, including the FDA approved drug Tolvaptan, could be utilized as novel ccRCC therapeutics.

De novo assembly, characterization of tissue-specific transcriptomes and identification of immune related genes from the scallop Argopecten purpuratus

The scallop Argopecten purpuratus is one of the most economically important cultured mollusks on the coasts from Chile and Peru but its production has declined, in part, due to the emergence of mass mortality events of unknown origin. Driven by this scenario, increasing progress has been made in recent years in the comprehension of immune response mechanisms in this species. However, it is still not entirely understood how different mucosal interfaces participate and cooperate with the immune competent cells, the hemocytes, in the immune defense. Thus, in this work we aimed to characterize the transcriptome of three tissues with immune relevance from A. purpuratus by next-generation sequencing and de novo transcriptome assembly. For this, 18 cDNA libraries were constructed from digestive gland, gills and hemocytes tissues of scallops from different immune conditions and sequenced by the Illumina HiSeq4000 platform. A total of 967.964.884 raw reads were obtained and 967.432.652 clean reads were generated. The clean reads were de novo assembled into 46.601 high quality contigs and 32.299 (69.31%) contigs were subsequently annotated. In addition, three de novo specific assemblies were performed from clean reads obtained from each tissue cDNA libraries for their comparison. Gene ontology (GO) and KEGG analyses revealed that annotated sequences from digestive gland, gills and hemocytes could be classified into both general and specific subcategory terms and known biological pathways, respectively, according to the tissue nature. Finally, several immune related candidate genes were identified, and the differential expression of tissue-specific genes was established, suggesting they could display specific roles in the host defense. The data presented in this study provide the first insight into the tissue specific transcriptome profiles of A. purpuratus, which should be considered for further research on the interplay between the hemocytes and mucosal immune responses.

ARA lncRNA, is upregulated in liver and breast tumor tissues

Important regulatory roles of long non-coding RNAs (lncRNAs) have been recently found, and reported as useful biomarkers in cancer. To identify a potential expression of the new discovered lncRNA (ARA), during promotes cell proliferation, apoptosis inhibit, migration and cell cycle arrest, we firstly evaluate its expression in two cancer tissues (breast cancer and liver cancer) and then compared its variability expression in tumor versus non-tumor samples. Expression profile of ARA lncRNA was evaluated using qRT-PCR in paired tumor and marginal non-tumor samples collected from patients who had been referred to the Shiraz General. After RNA extraction from tissue samples, cDNA synthesis and RT-qPCR method were performed according to the protocols. ARA lncRNA expression level was calculated using 2-ΔΔCt method. Principal-component analysis followed by receiver operating characteristic curve analyses was performed to evaluate the diagnostic potential of selected lncRNA. Our data revealed a significant upregulation (P < 0.001) of ARA in breast and liver tumor tissues, in comparison to same patients non-tumor marginal samples. Also, there was a significant difference between the expression of ARA lncRNA in breast cancer and liver cancer patients (P < 0.05). In conclusion, the results of our study suggest a possible role of ARA lncRNA in proliferation of breast and liver tissues, as well as its potential usefulness as a novel diagnostic biomarker for breast and liver tumors.

Abstract 4560: A cost-effective and rapid assay for profiling of immunobiology and the development of predictive signatures for response to immunotherapies

Abstract Introduction: Gene expression profiling is an important tool to monitor the human immune response to different antitumor agents for drug development and to identify predictive signatures for response to immunotherapies. We have developed and analytically validated a gene expression assay panel, namely the AdvantaTM Immuno-Oncology Gene Expression Assay (AdvantaTM I/O GE Assay), on the Fluidigm BiomarkTM HD system, a microfluidic real-time PCR system, for investigation of antitumor agent effects on immune inhibitory pathways. The assay panel consists of 170 unique gene targets in categories such as T cell subset markers (e.g., CD4), cytokines and chemokines (e.g., IFNg), immune regulation (e.g., PD-L1, PD-L2) and immune cell-fate markers (e.g., NK) associated with immune-checkpoint inhibitory pathways for cancer treatments. Method: The Assay consists of Fluidigm Dynamic Array™ IFCs, an assay panel and RT-PCR reagents. The assay panel is composed of TaqMan™ gene expression assays provided in two 96-well plates: 96 assays on one and 79 assays on another with 17 unused assay wells available for customization. Each plate contains five housekeeping genes for assay normalization. This assay configuration allows customers to test 96 samples on two Fluidigm 96.96 Dynamic Array™ IFCs. Two primer pools for preamplification, and a positive control have been developed along with a 24.192 Dynamic Array™ IFC which enables 24 samples and the complete panel, 170 genes to be run on a single IFC. The assay has been analytically validated by a third party (Q2/EA) on the 96.96 IFC. This study is to verify the assay and kit reagents on the 24.192 IFC. A universal RNA was reversely transcribed into cDNA and pre-amplified with the preamp primer pools for all 170 genes. Three tissue cDNAs (lymph node, brain and Jurkat cells) and the positive control, which contains all 170 targets, were used to evaluate amplification efficiency, linearity and reproducibility. Each sample was tested in three replicates on 24.192 IFCs in six independent runs. Results: The results show an average amplification efficiency across all assays of 98.2% and linearity (RSQ) 0.999 for universal RNA. The efficiency and linearity for the positive control are 0.999 and 0.998, respectively. The within-run replicate correlation (RSQ) is 0.997 for the universal RNA, 0.992 for Jurkat cDNA, 0.986 for brain cDNA, and 0.990 for lymph node cDNA. The between-IFC replicate correlation (RSQ) is 0.981 for universal RNA, 0.982 for Jurkat cDNA, 0.972 for brain cDNA and 0.977 for lymph node cDNA. Gene expression signatures for individual tissues were observed. Conclusions: The AdvantaTM I/O GE Assay on 24.192 IFC and the Fluidigm BiomarkTM HD system provides high amplification efficiency, excellent linearity and reproducibility and reduces the cost of routine laboratory testing for both immune checkpoint research and drug development. Citation Format: Peilin Chen, Sandy Spurgeon, Jing Wang, Michael Gonzales, Lianne McLean, Tom Goralski. A cost-effective and rapid assay for profiling of immunobiology and the development of predictive signatures for response to immunotherapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4560.