Strong Protein Expression Research Articles

O049 Maintaining long-term functional optogenetic stimulation for OSA therapy in a rodent model

Abstract Introduction Obstructive sleep apnoea (OSA) patients are often sub-optimally treated due to poor tolerance and/or incomplete responses to established therapies. Our novel therapy sensitises upper airway muscles to light (optogenetics) and allows their activation during sleep. Previous work has demonstrated that an adeno-associated viral vector (AAV) driven by a muscle-specific promoter produces strong expression of light-sensitive proteins (opsins) in the tongue, and strong light-evoked muscle activation 3-weeks after administration. Here we determine whether this response persists over 12-weeks, and whether immunosuppression is required. Methods Rats received intralingual injections of the AAV. After 12-weeks, opsin expression in the tongue was quantified via confocal imaging. Light-evoked muscle activation was recorded in a model of sleep-associated muscle hypotonia. This was repeated in three additional groups of animals. Group 1 received rapamycin (4 mg/kg/day) and cyclosporin (5 mg/kg/day), group 2 received prednisolone (1 mg/kg/day, tapering 10%/week from week 9), and group 3 received daily vehicle intrapleural injections. Results Without immunosuppression, opsin expression decreased ~4-fold in the tongue between 3- and 12-weeks post-AAV administration (two-way RM ANOVA, p=0.01). Subsequently, light-evoked muscle-activation also declined (linear mixed model, time*stimulation, p<0.001). With rapamycin/cyclosporin administration, light stimulation at 12-weeks was able to increase muscle-activation ~2-fold (p<0.001). Prednisolone and vehicle administration did not facilitate light-evoked muscle-activation at 12-weeks (p>0.05; LMM, group*stimulation p<0.001). Discussion Rapamycin/cyclosporin administration allows persistent opsin expression and light-evoked muscle activation. As all existing clinically approved AAV-mediated gene therapies require initial immune suppression, this requirement is not a barrier to clinical translation of an optogenetics-based therapy for OSA.

Toxicological screening of zinc oxide nanoparticles in mongrel dogs after seven days of repeated subcutaneous injections

Zinc oxide nanoparticles (ZnO NPs) have recently been applied in various veterinary and medical fields, however, the toxicological evaluations of these NPs in dogs are lacking. Therefore, the current study is designed to assess the impact of exposure to daily subcutaneous (SC) injections of ZnO NPs at different concentrations on various organs of mongrel dogs. Nine dogs were randomly divided into three groups (n = 3 for each) as follows: group (1) served as the control group, whereas groups (2&3) received SC injections of 50 and 100 ppm ZnO NPs (8 and 16 μg/kg bwt), respectively, once/day for 7 days. Our results revealed that ZnO NPs disrupted the oxidant/antioxidant balance in the lungs, liver, and kidneys of dogs in a dose-dependent manner. ZnO NPs induced dose-dependent radiological, ultrasonographical, and histopathological alterations in various organs especially lungs, spleen, liver, and kidneys along with disturbance in both liver and kidney biomarkers levels. Most organs of both ZnO NPs receiving groups displayed strong caspase-3 protein expression. Additionally, it upregulates the transcriptase levels of TNF-α and VEGF, as well as downregulates the antiapoptotic gene IL-10 in lung, kidney, and liver tissue homogenates. It was concluded that the daily SC injections of dogs with ZnO NPs at concentrations of 50 and 100 ppm caused extensive oxidative stress damage in various organs which provoked serious pathological processes such as apoptosis and inflammation.

Clinicopathological characteristics and prognosis of combined hepatocellular cholangiocarcinoma

There is limited research on the clinicopathological characteristics of combined hepatocellular-cholangiocarcinoma (cHCC-CCA) currently. The aim of this study is to summerize the clinicopathological factors and prognosis of cHCC-CCA, which could help us understand this disease. 72 cases of cHCC-CCA from West China Hospital of Sichuan University were collected. Tissue components were reviewed by pathologists. Immunohistochemistry was used to detect the status of mismatch repair (MMR) and human epidermal growth factor receptor 2 (HER2) in cHCC-CCA, as well as the quantity and distribution of CD3+ T cells and CD8+ T cells. Fluorescence in situ hybridization was used to detect fibroblast growth factor receptor 2 (FGFR2) gene alteration. COX univariate and multivariate analyses were used to evaluate risk factors, and survival curves were plotted. 49 cases were classified as classic type cHCC-CCA and 23 cases as intermediate cell carcinoma. The cut-off value for diagnosing classic type was determined to be ≥ 30% for the cholangiocarcinoma component based on prognostic calculations. All tumors were MMR proficient. The rate of strong HER2 protein expression (3+) was 8.3%, and the frequency of FGFR2 gene alteration was 26.4%. CD3+ T cells and CD8+ T cells were mainly distributed at the tumor margin, and were protective factors for patients with cHCC-CCA. The overall survival of the 72 patients was 18.9 months, with a median survival of 12 months. Tumor size, TNM stage, and serum AFP level were prognostic factors for cHCC-CCA. The proportion of cholangiocarcinoma component reaching the threshold of 30%, may provide a reference for future pathology diagnosis. FGFR2 gene alteration was 26.4%, providing a clue for anti-FGFR2 therapy. However, more data is needed for further verification.

Altered enhancer-promoter interaction leads to MNX1 expression in pediatric acute myeloid leukemia with t(7;12)(q36;p13)

AbstractAcute myeloid leukemia (AML) with the t(7;12)(q36;p13) translocation occurs only in very young children and has a poor clinical outcome. The expected oncofusion between break point partners (motor neuron and pancreas homeobox 1 [MNX1] and ETS variant transcription factor 6 [ETV6]) has only been reported in a subset of cases. However, a universal feature is the strong transcript and protein expression of MNX1, a homeobox transcription factor that is normally not expressed in hematopoietic cells. Here, we map the translocation break points on chromosomes 7 and 12 in affected patients to a region proximal to MNX1 and either introns 1 or 2 of ETV6. The frequency of MNX1 overexpression in pediatric AML is 2.4% and occurs predominantly in t(7;12)(q36;p13) AML. Chromatin interaction assays in a t(7;12)(q36;p13) induced pluripotent stem cell line model unravel an enhancer-hijacking event that explains MNX1 overexpression in hematopoietic cells. Our data suggest that enhancer hijacking may be a more widespread consequence of translocations in which no oncofusion product was identified, including t(1;3) or t(4;12) AML.

P-628 The role of Anti-Müllerian Hormone (AMH) on human osteoblast differentiation

Abstract Study question May AMH, an ovarian hormone belonging to the Transforming Growth Factor β superfamily (TGF-β), represent a possible candidate for use as a bone anabolic factor? Summary answer Our findings provided interesting clues on the stimulatory effects of AMH on mature osteoblasts expressing its specific receptor, the Anti-Müllerian Hormone Type-2 receptor (AMHRII). What is known already Impaired bone formation is a principal pathogenetic mechanism mediating bone fragility in osteoporosis. Several growth factors capable of inducing bone matrix apposition by increasing the number of osteoblast precursor cells or promoting the function of mature osteoblasts have been identified, including members of the TGF-β superfamily such as BMPs. However, their clinical use is limited due to their pleiotropic extraskeletal effects. Anti-Müllerian Hormone (AMH) is a member of the TGF-β superfamily whose role in bone tissues has never been investigated. To date, AMH functions and the expression of its specific receptor are mainly limited to the reproductive organs. Study design, size, duration We performed in vitro studies on Human Osteoblasts (HOb) to evaluate the expression and the functionality of AMH receptor type-2 and investigate the effects of recombinant AMH (rhAMH) exposure on osteogenic gene expression and osteoblast functions. Participants/materials, setting, methods RT-PCR, real-time PCR and Western blotting analyses were performed in Hob cells cultured both in the presence and in the absence of 100 ng/mL rhAMH to evaluate the effect of AMH exposure on osteoblast differentiation. Alizarin red staining was performed after 14 days of treatment with 100 ng/mL rhAMH to assess the mineralized nodule formation. Main results and the role of chance Our study revealed the presence of a strong mRNA and protein expression of AMHRII in HOb cells, thus indicating that osteoblasts may represent a specific target for exogenous AMH treatment. We also observed that rhAMH exposure increased SMAD 1/5 protein levels, demonstrating that the binding of AMHRII by AMH was able to activate the SMAD-mediated AMH signalling pathway. Interestingly, we also observed that AMH treatment upregulates mRNA levels of crucial osteoblastic transcription factors such as RUNX2 and OSX and extracellular matrix proteins including OPN and OC. Consistently, the prolonged exposure to AMH also promoted matrix mineralization in HOb cells, as demonstrated by both increased ALP gene expression and the greater amount of mineralized nodules observed in AMH-treated osteoblasts compared to untreated controls. Limitations, reasons for caution The study was conducted only in HOb cells. Additional functional studies are needed to investigate the action mechanism of AMH in the other bone cells to understand the mechanisms by which AMH may influence bone homeostasis and pave the way for subsequent in vivo studies. Wider implications of the findings This study may have translation value in opening the perspective that AMH may be an effective candidate to counteract bone loss in osteoporotic patients by developing a new therapy selectively targeting osteoblast with minimal off-target effect. Trial registration number Not Applicable

Canine Mammary Tumors as a Potential Model for Human Breast Cancer in Comparative Oncology.

Clinical and molecular similarities between canine mammary tumors (CMTs) and human breast cancer (HBC) propel scientists to further study their application in comparative oncology as a model for human breast cancer. In total, 64 canine mammary tumors were selected to study the most common markers, which are applicable for human breast cancer treatment, including estrogen and progesterone receptors (ER and PR), human epidermal growth factor (HER2/neu), Ki67, and cyclooxygenase 2 (Cox2). Immunohistochemistry (IHC) was used to assess the protein expression. The Veterinary Nottingham Prognostic Index (Vet-NPI) was also computed. Moreover, univariate and multivariable Cox proportional hazard analyses were applied to estimate hazard ratios (HRs). The results demonstrated that Ki67 was strongly expressed in the triple-negative tumors, and Ki67 protein expression continuously increased over the increase of Cox2 protein expression (p < 0.001). Further analysis revealed a significant difference among canine mammary subtypes and Vet-NPI, in which triple-negative tumors displayed the highest mean score compared to other subtypes (p < 0.001). In addition, the multivariable analysis revealed that the regional mastectomy procedure (adjusted HR = 2.78 (1.14-6.8)), the triple-negative tumors (adjusted HR = 48.08 (7.74-298.8)), strong Ki67 protein expression group (adjusted HR = 7.88 (2.02-30.68)), and strong Cox2 protein expression group (adjusted HR = 29.35 (5.18-166.4)) demonstrated significantly lower disease-free survival rates compared to other corresponding groups. Overall, canine mammary tumors showed strong similarities to human breast cancer in terms of clinical and molecular aspects; therefore, they could be suggested as a model for human breast cancer in comparative oncology.

Ionizable Polymeric Micelles with Phenylalanine Moieties Enhance Intracellular Delivery of Self-Replicating RNA for Long-Lasting Protein Expression In Vivo.

mRNA-based therapeutics are revolutionizing the landscape of medical interventions. However, the short half-life of mRNA and transient protein expression often limits its therapeutic potential, demanding high treatment doses or repeated administrations. Self-replicating RNA (RepRNA)-based treatments could offer enhanced protein production and reduce the required dosage. Here, we developed polymeric micelles based on flexible poly(ethylene glycol)-poly(glycerol) (PEG-PG) block copolymers modified with phenylalanine (Phe) moieties via biodegradable ester bonds for the efficient delivery of RepRNA. These polymers successfully encapsulated RepRNA into sub-100 nm micelles assisted by the hydrophobicity of the Phe moieties and their ability to π-π stack with the bases in RepRNA. The micelles made from Phe-modified PEG-PG (PEG-PG(Phe)) effectively maintained the integrity of the loaded RepRNA in RNase-rich serum conditions. Once taken up by cells, the micelles triggered a pH-responsive membrane disruption, promoted by the strong protonation of the amino groups at endosomal pH, thereby delivering the RepRNA to the cytosol. The system induced strong protein expression in vitro and outperformed commercial transfecting reagents in vivo, where it resulted in enhanced and long-lasting protein expression.

SLC11A1 predicts the overall survival of patients with colorectal cancer.

Colorectal cancer (CRC) remains a significant contributor to cancer-related mortality, emphasizing the critical need for identifying biomarkers that can improve clinical management and patient outcomes. In this retrospective study, we analyzed tumor samples from 25 patients with metastatic CRC, categorized based on long-term (> 50 months) or short-term (< 10 months) survival. Employing the PanCancer Immune Profile Panel, encompassing 770 genes, in the discovery dataset, we identified 54 differentially expressed genes (DEGs) within the tumor microenvironment of metastatic CRC. Validation of potential biomarkers was performed using two publicly available RNA-based sequencing datasets (TCGA 1 (n=371) and TCGA 2 (n=566)). Univariate COX regression unveiled that three significant biomarkers were associated with overall survival in CRC within the discovery dataset, which were SLC11A1 (hazard ratio (HR): 4.09, P=0.012), TNFSF11 (HR: 3.67, P=0.02), and MEF2C (HR: 0.34, P=0.037). Kaplan-Meier survival curve analyses confirmed the correlation between SLC11A1 expression and overall survival in CRC across the discovery set (P=0.0071) and the two independent datasets (TCGA 1 (P=0.0016) and TCGA 2 (P=0.025)). Receiver operating characteristic curve analysis demonstrated an area under the curve ranging from 0.64 to 0.76, with sensitivity of 59% to 87% and specificity of 60% to 73% for predicting CRC overall survival. Immunohistochemistry staining further validated the strong expression of SLC11A1 protein in CRC tumor cells, with high expression correlating with short-term survival. These findings suggest that SLC11A1 serves as a predictive biomarker for overall survival in CRC patients.

Molecular and Pathologic Characterization of YAP1-Expressing Small Cell Lung Cancer Cell Lines Leads to Reclassification as SMARCA4-Deficient Malignancies.

The classification of small cell lung cancer (SCLC) into distinct molecular subtypes defined by ASCL1, NEUROD1, POU2F3, or YAP1 (SCLC-A, -N, -P, or -Y) expression, paves the way for a personalized treatment approach. However, the existence of a distinct YAP1-expressing SCLC subtype remains controversial. To better understand YAP1-expressing SCLC, the mutational landscape of human SCLC cell lines was interrogated to identify pathogenic alterations unique to SCLC-Y. Xenograft tumors, generated from cell lines representing the four SCLC molecular subtypes, were evaluated by a panel of pathologists who routinely diagnose thoracic malignancies. Diagnoses were complemented by transcriptomic analysis of primary tumors and human cell line datasets. Protein expression profiles were validated in patient tumor tissue. Unexpectedly, pathogenic mutations in SMARCA4 were identified in six of eight SCLC-Y cell lines and correlated with reduced SMARCA4 mRNA and protein expression. Pathologist evaluations revealed that SMARCA4-deficient SCLC-Y tumors exhibited features consistent with thoracic SMARCA4-deficient undifferentiated tumors (SMARCA4-UT). Similarly, the transcriptional profile SMARCA4-mutant SCLC-Y lines more closely resembled primary SMARCA4-UT, or SMARCA4-deficient non-small cell carcinoma, than SCLC. Furthermore, SMARCA4-UT patient samples were associated with a YAP1 transcriptional signature and exhibited strong YAP1 protein expression. Together, we found little evidence to support a diagnosis of SCLC for any of the YAP1-expressing cell lines originally used to define the SCLC-Y subtype. SMARCA4-mutant SCLC-Y cell lines exhibit characteristics consistent with SMARCA4-deficient malignancies rather than SCLC. Our findings suggest that, unlike ASCL1, NEUROD1, and POU2F3, YAP1 is not a subtype defining transcription factor in SCLC. See related commentary by Rekhtman, p. 1708.

Malignant gastrointestinal neuroectodermal tumor: a case report and literature review

Introduction and importance: A malignant gastrointestinal neuroectodermal tumor (GNET) is an extremely rare primary malignant mesenchymal tumor of the gastrointestinal tract characterized by EWSR1 gene rearrangement. An optimal systemic treatment strategy for advanced/recurrent GNET has not yet been identified. Case presentation: A 24-year-old male patient was hospitalized with abdominal pain and underwent two operations for a tumor in his small intestine. Immunohistochemistry (IHC) showed strong expression of S-100 protein and SOX 10. Fluorescence in situ hybridization analysis and next-generation sequencing analysis indicated that there were EWSR gene rearrangements and the presence of EWSR-ATP1 gene fusions, respectively. The diagnosis of GNET in the small intestine was confirmed by pathology. The young patient received the fifth-line of apatinib mesylate and the sixth-line of apatinib combined with temozolomide. The two apatinib-containing regimens showed stable disease and progression-free survival of 4.7 months and 3.1 months with single-agent apatinib or apatinib combined with temozolomide, respectively. Clinical discussion: To our best knowledge, this is the first report of malignant GNET treated with apatinib and temozolomide. Apatinib-containing regimens might has antineoplastic activity against GNET. The authors reviewed the relevant reports of previous GNET treatment, summarized the clinicopathological characteristics of GNET, and found that there are no reports of apatinib for backline treatment of GNET. Conclusion: Containing apatinib may provide an additional treatment option for patients with chemotherapy-resistant GNET tumors.

S100 Protein Expression in Primary and Metastatic Neuroendocrine Neoplasms: A Specific Marker of Pancreatic Origin.

Neuroendocrine neoplasms can arise in a wide variety of anatomic sites including the gastrointestinal tract, pancreas, and lung, among others. Here, we report on the expression of S100 protein in a tissue microarray composed of 919 distinct primary and metastatic neuroendocrine neoplasms from 548 patients. S100 protein is a commonly used marker in many laboratories for the identification of neural and melanocytic neoplasms and occasionally used in the workup for neuroendocrine neoplasms when the diagnosis of paraganglioma is being considered. We show that strong S100 protein expression is highly specific to well-differentiated neuroendocrine tumors of pancreatic origin. This finding suggests potential diagnostic utility of this marker in cases of tumors of unknown origin, and emphasizes that S100 protein expression should not be an unexpected finding in neuroendocrine tumors of pancreatic origin.

Immunohistochemical Expression of Glutathione Peroxidase-2 (Gpx-2) and Its Clinical Relevance in Colon Adenocarcinoma Patients.

Glutathione peroxidase 2 (Gpx-2) is a selenoenzyme with antioxidant capabilities that may play a role in cancer development. Hence, we investigated the immunohistochemical expression of Gpx-2 protein in colon adenocarcinoma samples derived from patients with colon adenocarcinoma who did not receive any form of treatment prior to the surgical procedure. The associations between the immunohistochemical expression of Gpx-2 and clinical parameters were analysed using the Chi2 test and Fisher's exact test. A Kaplan-Meier analysis and the log-rank test were used to verify the relationship between the intensity of Gpx-2 expression and the 5-year survival rate of patients. In total, 101 (80.80%) samples had strong Gpx-2 protein expression and 24 (19.20%) samples were characterized with low expression. The high expression of Gpx-2 was correlated with the histological grade of the tumour (p < 0.001), PCNA immunohistochemical expression (p < 0.001), depth of invasion (p = 0.001) and angioinvasion (p < 0.001). We can conclude that high expression of Gpx-2 is correlated with reduced survival of colon adenocarcinoma patients (log-rank, p < 0.001).

Development of an Efficient Recombinant Protein Expression System in Clostridium saccharoperbutylacetonicum Based on the Bacteriophage T7 System.

Recombinant proteins have broad applications. However, there is a lack of a recombinant protein expression system specifically for large-scale production in anaerobic hosts. Here, we developed a powerful and stringently inducible protein expression system based on the bacteriophage T7 system in the strictly anaerobic solvent-producing Clostridium saccharoperbutylacetonicum. With the integration of a codon optimized T7 RNA polymerase into the chromosome, a single plasmid carrying a T7 promoter could efficiently drive high-level expression of the target gene in an orthogonal manner, which was tightly regulated by a lactose-inducible system. Furthermore, by deleting beta-galactosidase genes involved in lactose metabolism, the transcriptional strength was further improved. In the ultimately optimized strain TM-07, the transcriptional strength of the T7 promoter showed 9.5-fold increase compared to the endogenous strong promoter Pthl. The heterologous NADP+-dependent 3-hydroxybutyryl-CoA dehydrogenase (Hbd1) from C. kluyveri was expressed in TM-07, and the yield of the recombinant protein reached 30.4-42.4% of the total cellular protein, surpassing the strong protein expression systems in other Gram-positive bacteria. The relative activity of Hbd1 in the crude enzyme was 198.0 U/mg, which was 8.3-fold higher than the natural activity in C. kluyveri. The relative activity of the purified enzyme reached 467.4 U/mg. To the best of our knowledge, this study represents the first application of the T7 expression system in Clostridium species, and this optimized expression system holds great potential for large-scale endotoxin-free recombinant protein production under strictly anaerobic conditions. This development paves the way for significant advancements in biotechnology and opens up new avenues for industrial applications.

Expression of the schizophrenia associated gene FEZ1 in the early developing fetal human forebrain.

The protein fasciculation and elongation zeta-1 (FEZ1) is involved in axon outgrowth but potentially interacts with various proteins with roles ranging from intracellular transport to transcription regulation. Gene association and other studies have identified FEZ1 as being directly, or indirectly, implicated in schizophrenia susceptibility. To explore potential roles in normal early human forebrain neurodevelopment, we mapped FEZ1 expression by region and cell type. All tissues were provided with maternal consent and ethical approval by the Human Developmental Biology Resource. RNAseq data were obtained from previously published sources. Thin paraffin sections from 8 to 21 post-conceptional weeks (PCW) samples were used for RNAScope in situ hybridization and immunohistochemistry against FEZ1 mRNA and protein, and other marker proteins. Tissue RNAseq revealed that FEZ1 is highly expressed in the human cerebral cortex between 7.5-17 PCW and single cell RNAseq at 17-18 PCW confirmed its expression in all neuroectoderm derived cells. The highest levels were found in more mature glutamatergic neurons, the lowest in GABAergic neurons and dividing progenitors. In the thalamus, single cell RNAseq similarly confirmed expression in multiple cell types. In cerebral cortex sections at 8-10 PCW, strong expression of mRNA and protein appeared confined to post-mitotic neurons, with low expression seen in progenitor zones. Protein expression was observed in some axon tracts by 16-19 PCW. However, in sub-cortical regions, FEZ1 was highly expressed in progenitor zones at early developmental stages, showing lower expression in post-mitotic cells. FEZ1 has different expression patterns and potentially diverse functions in discrete forebrain regions during prenatal human development.

Abstract PR001: Development and characterization of novel pre-clinical models of SFPQ-TFE3-driven renal cell carcinoma

Abstract Translocation Renal Cell Carcinomas (tRCC) are characterized by gene fusions that drive expression of chimeric TFE3 (Xp11.2) or TFEB (6p21.2). We developed and characterized a mouse model and inducible cell line expressing the SFPQ-TFE3 gene fusion to aid in biomarker and therapy development for this tumor type. We generated a murine knock-in model at the Rosa26 locus expressing the human SFPQ (exons 1-9) -TFE3 (exons 5-10) fusion gene downstream of a lox-stop-lox (LSL) sequence, under control of a chicken beta-actin promoter, on the C57BL/6 background. We crossed these LSL-SFPQ-TFE3 mice with the Cdh16-Cre model to induce SFPQ-TFE3 expression in renal epithelial cells. As an in vitro companion model, we generated HEK293 cells with stable doxycycline-inducible expression of the identical SFPQ-TFE3 fusion using the Flp-In T-RExTM system (SFPQ-TFE3-HEK293).Cdh16-Cre;LSL-SFPQ-TFE3 mice had reduced survival compared to the wild-type mice (p&amp;lt;0.0001) and none survived past P19. At P1, Cdh16-Cre;LSL-SFPQ-TFE3 mice had scattered mild tubular dilation, with strong nuclear TFE3 protein expression in distal tubules and collecting ducts that was absent in controls. By P15, Cdh16-Cre;LSL-SFPQ-TFE3 kidneys were 30% larger than wild-type mice (p&amp;lt;0.0001), with diffuse and strong nuclear expression of TFE3 throughout the majority of renal tubules. At this timepoint, Cdh16-Cre;LSL-SFPQ-TFE3 kidneys had prominent intratubular proliferation of renal epithelial cells, occasionally occluding the lumen, with diffuse psammomatous intraluminal calcification and mild patchy tubular dilatation. Glomerular morphology and size were not significantly different between the two groups at P15. However, the Cdh16-Cre;LSL-SFPQ-TFE3 mice had a lower density of glomeruli compared to the wild-type controls (5 glomeruli/mm² vs 50 glomeruli/mm²; p=0.03), potentially reflecting tubular expansion or aberrant glomerulogenesis. Wild-type and Cdh16-Cre;LSL-SFPQ-TFE3 mice exhibited similar tubular proliferative rate at P1 as assessed by Ki67. By P7, Cdh16-Cre;LSL-SFPQ-TFE3 mice showed significantly higher expression of Ki67 (p=0.03) but by P15, Ki67 index was lower (p=0.004) in the Cdh16-Cre;LSL-SFPQ-TFE3 mice compared to controls. Interestingly, by 48 hours after doxycycline induction, SFPQ-TFE3-HEK293 cells showed significantly decreased proliferation by MTT assay compared to the same cells without doxycycline treatment or to the parental Flp-In line treated with doxycycline (p=0.0002). A novel transgenic model for SFPQ-TFE3-driven tRCC shows early postnatal lethality, likely due to renal failure, precluding aging of these mice for tumor development. Though tubular proliferation is initially increased with SFPQ-TFE3 expression, Ki-67 expression is reduced by P15, paralleling the reduction in growth seen in inducible SFPQ-TFE3-HEK293 cells. These data suggest that SFPQ-TFE3 expression may paradoxically result in oncogene-induced senescence or cell cycle arrest in renal cells and further studies are underway to test this hypothesis. Citation Format: Adrianna Amaral de Aragao Mendes, Hans Liu, Juhyung Woo, Kaushal Asrani, Avi Rosenberg, Pedram Argani, Tamara Lotan. Development and characterization of novel pre-clinical models of SFPQ-TFE3-driven renal cell carcinoma [abstract]. In: Proceedings of the AACR Special Conference: Advances in Kidney Cancer Research; 2023 Jun 24-27; Austin, Texas. Philadelphia (PA): AACR; Cancer Res 2023;83(16 Suppl):Abstract nr PR001.

Establishment of a high-efficiency transformation and genome editing method for an essential vegetable and medicine Solanum nigrum.

Solanum nigrum, which belongs to the Solanaceae family, is an essential plant for food and medicine. It has many important secondary compounds, including glycoproteins, glycoalkaloids, polyphenolics, and anthocyanin-rich purple berries, as well as many ideal characteristics such as self-fertilization, a short life cycle and a small genome size that make it a potential model plant for the study of secondary metabolism and fruit development. In this study, we report a highly efficient and convenient tissue culture, transformation and genome editing method for S. nigrum using leaf segments after 8 weeks of tissue culture, with a required period from transformation initiation to harvest of about 3.5 months. Our results also show multi-shoot regeneration per leaf segment and a 100% shoot regeneration efficiency in a shoot regeneration medium. Moreover, over 82% of kanamycin-resistant plants exhibited strong green fluorescence marker protein expression, with genetic integration confirmed by PCR results and green fluorescence protein expression in their T1 progeny. Furthermore, we successfully applied this transformation method to achieve an average of 83% genome editing efficiency of SnMYB1, a gene involved in regulating the anthocyanin biosynthetic pathway of S. nigrum in response to missing nutrients. Taken together, the combination of highly efficient tissue culture, transformation and genome editing systems can provide a powerful platform for supporting fundamental research on the molecular mechanisms of secondary metabolism, fruit development, and production of important compounds by biotechnology.

Abstract A008: Elucidating the effects of the Alzheimer's disease associated gene BIN1 on cancer tumorigenesis

Abstract Purpose- BIN1 is in deleted in ~5% of all prostate cancer (PC) patients and interestingly is highly enriched in the Speckle-type POZ protein (SPOP) mutant subclass (15%) of PC. BIN1 was originally identified as a repressor of cMYC activity and our lab has shown that patients with SPOPmut;MYChigh PC have worse clinical outcomes. Our observation of BIN1 deletion in the SPOP mutant subclass leads us to hypothesize that BIN1 deletion leads to enhanced AR signaling and more aggressive PC. Experimental Procedures- We analyzed baseline protein and mRNA levels of BIN1 in 13 PC cell lines via quantitative polymerase chain reaction (qPCR) and immunoblot. To understand the role of BIN1 in PC cells, we overexpressed BIN1 and evaluated changes in cell proliferation, migration, and AR target gene expression. To elucidate the role of BIN1 in vivo prostate development, we also generated a prostate-specific knockout of BIN1 and investigated changes in prostate development and AR signaling axis over time in this mouse model. Results- Our results show that none of the 13 PC cell lines analyzed had strong protein expression at baseline, but all had detectable mRNA levels. Interestingly, the three cell lines with the highest mRNA expression were AR negative (DU-145), AR independent (LN95) or castration resistant (MDVR). We also saw a decrease in downstream AR target genes (KLK3 and NKX3.1) measured using qPCR after BIN1 overexpression in 22Rv1 cells. We further corroborated this finding by measuring KLK3 expression using a KLK3-luc reporter assay after BIN1 overexpression. BIN1 overexpression also reduced invasive activity of 22Rv1 measured using a Matrigel invasion assay system. Since BIN1 deletion was enriched in SPOP mutant PC clinical data, we evaluated changes in cell proliferation in the wildtype and mutant SPOP cell lines with and without BIN1OE and found that BIN1OEhindered growth of SPOP mutant PC cells. Analysis of the TCGA primary PC dataset illustrate that PC patients harboring BIN1 deletion had higher AR activity compared to PC patients expressing wildtype BIN1. Importantly, mice with prostate specific BIN1 deletion had larger prostate mass at 2 months of age compared to age matched controls and several mice at the 6&amp;9 month had severely enlarged prostates. Conclusion- Our findings show for the first time that BIN1 functions as an inhibitor of the AR signaling axis and deletion of BIN1 leads to higher levels of AR signaling. We also show that BIN1 deletion in mice affects prostate development and leads to enlarged prostates. These novel findings illustrate the clinical significance of BIN1 deletion in PC patients and highlights the AR-signaling axis as a potential target for PC patients with BIN1 deletion Citation Format: Collin McColl, Darlene Skapura, Elisa Echartea, Jenny Deng, Cristian Coarfa, Salma Kaochar, Brian Simons, Aleksandra Rusin. Elucidating the effects of the Alzheimer's disease associated gene BIN1 on cancer tumorigenesis [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A008.

Mechanistic Approach on the Pulmonary Oxido-Inflammatory Stress Induced by Cobalt Ferrite Nanoparticles in Rats

Cobalt ferrite nanoparticles (CFN) are employed in data storage, imaging, medication administration, and catalysis due to their superparamagnetic characteristics. The widespread use of CFN led to significantly increased exposure to people and the environment to these nanoparticles. Until now, there is not any published paper describing the adverse effect of repeated oral intake of this nanoformulation on rats’ lungs. So, the current research aims to elucidate the pulmonary toxicity prompted by different concentrations of CFN in rats as well as to explore the mechanistic way of such toxicity. We used 28 rats that were divided equally into 4 groups. The control group received normal saline, and the experimental groups received CFN at dosage levels 0.05, 0.5, and 5 mg/kg bwt. Our findings revealed that CFN enhanced dose-dependent oxidative stress manifested by raising in the MDA levels and declining in the GSH content. The histopathological examination revealed interstitial pulmonary inflammation along with bronchial and alveolar damage in both 0.5 and 5 mg CFN given groups. All these lesions were confirmed by the immunohistochemical staining that demonstrated strong iNOS and Cox-2 protein expression. There was also a significant upregulation of TNFα, Cox-2, and IL-1β genes with downregulation of IL-10 and TGF-β genes. Additionally, the group receiving 0.05 mg CFN did not exhibit any considerable toxicity in all measurable parameters. We concluded that the daily oral intake of either 0.5 or 5 mg CFN, but not 0.05 mg, could induce pulmonary toxicity via NPs and/or its leached components (cobalt and iron)-mediated oxido-inflammatory stress. Our findings may help to clarify the mechanisms of pulmonary toxicity generated by these nanoparticles through outlining the standards for risk assessment in rats as a human model.

The Clinical Application of Immunohistochemical Expression of Notch4 Protein in Patients with Colon Adenocarcinoma.

The Notch signalling pathway is one of the most conserved and well-characterised pathways involved in cell fate decisions and the development of many diseases, including cancer. Among them, it is worth noting the Notch4 receptor and its clinical application, which may have prognostic value in patients with colon adenocarcinoma. The study was performed on 129 colon adenocarcinomas. Immunohistochemical and fluorescence expression of Notch4 was performed using the Notch4 antibody. The associations between the IHC expression of Notch4 and clinical parameters were analysed using the Chi2 test or Chi2Yatesa test. The Kaplan-Meier analysis and the log-rank test were used to verify the relationship between the intensity of Notch4 expression and the 5-year survival rate of patients. Intracellular localisation of Notch4 was detected by the use of the immunogold labelling method and TEM. 101 (78.29%) samples had strong Notch4 protein expression, and 28 (21.71%) samples were characterised by low expression. The high expression of Notch4 was clearly correlated with the histological grade of the tumour (p < 0.001), PCNA immunohistochemical expression (p < 0.001), depth of invasion (p < 0.001) and angioinvasion (p < 0.001). We can conclude that high expression of Notch4 is correlated with poor prognosis of colon adenocarcinoma patients (log-rank, p < 0.001).

Abstract 3406: GATA2 a novel potential therapeutic target for treatment of neuroendocrine prostate cancer

Abstract Neuroendocrine Prostate Cancer (NEPC) is a lethal and aggressive variant of prostate cancer (PC), arises from prostate adenocarcinoma, mainly as a treatment resistant mechanism to Androgen Receptor (AR) signaling inhibitors like enzalutamide. It is independent of AR signaling and characterized by upregulation of neuroendocrine markers like CHGA, SYP, EZH2, MYCN, and CD56. Despite of therapeutic advances, this lethal subtype of PC remains undruggable and has a shorter survival period. Our lab, as well as others, have previously reported several critical functions of GATA2 in AR signaling in PC progression, but the role of GATA2 in NEPC, remained unclear. Here we investigated the role of GATA2 in NEPC using our Patient Derived Xenografts (PDXs), 3D organoid, and 2D cell line models and characterized the pharmacological potency of K-11706, a small molecule inhibitor (SMI) for GATA2 against those NEPC models. To overcome the absence of suitable in vitro models for NEPC, first, we developed 3D organoid and 2D cell line models from NEPC PDX models generated and shared by Dr. Nora Navone at MDACC (mdpc 155-2 and mdpc 144-13). Molecular and histological characterization of these newly developed models showed retention of parent molecular and histological features of their corresponding PDXs. Immunohistochemical characterization of NEPC patient samples and PDXs shows a strong expression of GATA2 protein. Similarly, enzalutamide sensitive cells (16DCRPC cells) showed a significant upregulation of GATA2 mRNA along with neuroendocrine marker genes upon treatment with enzalutamide suggesting upregulation of GATA2 during progression from Castration Resistant Prostate Cancer (CRPC) to NEPC. Pharmacological inhibition of GATA2 by a previously reported SMI, K-11706, efficiently reduced 3D organoid growth and cell viability in vitro, suggesting GATA2 as a potential therapeutic target for NEPC. Gene set enrichment analysis (GSEA) involving our RNA seq data from NEPC cell lines after both K-11706 treatment as well as silencing GATA2 using siRNA (siGATA2) shows a high enrichment score with respect to EZH2 inhibition in curated datasets involving EZH2 inhibition. MTT assay involving a combination of K-11706 and EPZ6438 (EZH2 inhibitor) reduced NEPC cell viability more efficiently than used alone, suggesting a combinational strategy for the treatment of this lethal aggressive PC. NEPC cell line transcriptional profiling and functional pathway analysis of the K-11706 and siGATA2 transcriptomic footprint against curated databases delineated a biological network composed of genes involved in the epithelial mesenchymal transition, hypoxia, genes regulated by NF-kB in response to TNF and KRAS signaling. Based on these results, we propose GATA2 as an actionable therapeutic target for the treatment of NEPC, and pharmacological inhibition of both GATA2 and EZH2 by small molecule inhibitors is effective in NEPC models in vitro. Citation Format: Amit K. Dash, Maria Elisa Ruiz Echartea, Darlene Skapura, Karen Berman de Ruiz, Jenny Jianmin Deng, Cristian Coarfa, Salma Kaochar. GATA2 a novel potential therapeutic target for treatment of neuroendocrine prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3406.