Counting Assay Research Articles

Biosynthesized silver nanoparticles prevent bacterial infection in chicken egg model and mitigate biofilm formation on medical catheters.

Investigating the application of innovative antimicrobial surface coatings on medical devices is an important field of research. Many of these coatings have significant drawbacks, including biocompatibility, coating stability and the inability to effectively combat multiple drug-resistant bacteria. In this research, we developed an antibiofilm surface coating for medical catheters using biosynthesized silver nanoparticles (b-Cs-AgNPs) developed using leaves extract of Calliandra surinamensis. Various characterization techniques were employed to thoroughly characterize the synthesized b-Cs-AgNPs and c-AgNPs. b-Cs-AgNPs were compatible with human normal kidney cells and chicken embryos. It did not trigger any skin inflammatory response in in vivo rat model. b-Cs-AgNPs demonstrated potent zone of inhibition of 19.09mm when subjected to the disc diffusion method in E. coli confirming strong antibacterial property. Different anti-bacterial assays including liquid growth curve, colony counting assay, biofilm formation assay supported the potent antimicrobial efficacy of b-Cs-AgNPs alone and when coated to medical grade catheters. Mechanistic studies reveal the presence of ferulic acid, that was important for the synthesis of b-AgNPs along with enhanced antibacterial effects of b-Cs-AgNPs compared to c-AgNPs, supported by molecular docking analysis. These results together demonstrated the effective role b-Cs-AgNPs in combating infections and mitigating biofilm formations, highlighting their need for further study in the field of biomedical applications.

MiR-329b-5p Affects Sheep Intestinal Epithelial Cells against Escherichia coli F17 Infection.

Diarrhea is the most common issue in sheep farms, typically due to pathogenic Escherichia coli (E. coli) infections, such as E. coli F17. microRNA, a primary type of non-coding RNA, has been shown to be involved in diarrhea caused by pathogenic E. coli. To elucidate the profound mechanisms of miRNA in E. coli F17 infections, methods such as E. coli F17 adhesion assay, colony counting assay, relative quantification of bacterial E. coli fimbriae gene expression, indirect immune fluorescence (IF), Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), Western blotting (WB), and scratch assay were conducted to investigate the effect of miR-329b-5p overexpression/knock-down on E. coli F17 susceptibility of sheep intestinal epithelial cells (IECs). The findings indicated that miR-329b-5p enhances the E. coli F17 resistance of sheep IECs to E.coli F17 by promoting adhesion between E. coli F17 and IEC, as well as IEC proliferation and migration. In summary, miR-329b-5p plays a crucial role in the defense of sheep IECs against E. coli F17 infection, providing valuable insights into its mechanism of action.

Low concentrations of TNF-α invitro transform the phenotype of vascular smooth muscle cells and enhance their survival in a three-dimensional culture system.

Vascular smooth muscle cells (VSMCs) are commonly used as seed cells in tissue-engineered vascular constructions. However, their variable phenotypes and difficult to control functions pose challenges. This study aimed to overcome these obstacles using a three-dimensional culture system. Calf VSMCs were administered tumor necrosis factor-alpha (TNF-α) before culturing in two- and three-dimensional well plates and polyglycolic acid (PGA) scaffolds, respectively. The phenotypic markers of VSMCs were detected by immunofluorescence staining and western blotting, and the proliferation and migration abilities of VSMCs were detected by CCK-8, EDU, cell counting, scratch, and Transwell assays. TNF-α rapidly decreased the contractile phenotypic markers and elevated the synthetic phenotypic markers of VSMCs, as well as markedly increasing the proliferation and migration ability of VSMCs under two- and three-dimensional culture conditions. TNF-α can rapidly induce a phenotypic shift in VSMCs and change their viability on PGA scaffolds.

Accuracy, use and acceptability of the VISITECT CD4 semi-quantitative test to advance HIV disease screening in routine programmatic settings in Tanzania

BackgroundThe available few laboratory-based CD4 assay for People Living with HIV (PLHIV) experience supply stock-outs and instrument breakdowns in developing countries, affecting the ability to diagnose Advance HIV disease (AHD). We evaluated the performance of the VISITECT CD4 point of care test among healthcare workers in HIV program in Tanzania. MethodsA retrospective diagnostic accuracy study was conducted among PLHIV who received both the VISITECT CD4 and a standard-of-care. Acceptability of the VISITECT CD4 by healthcare workers was assessed using a structured questionnaire. Both FACS Count and Pima CD4 assay were considered as reference standards. Findings were summarized as proportions with 95 % confidence intervals (CI). Data were analyzed using STATA 17 (StataCorp, College Station, TX). ResultsA total of 1370 PLHIV were tested using VISITECT CD4 across 20 facilities between 3 April and 14 September 2022. The median age was 37 (Interquartile range (IQR):29–46). Overall, 897 (65.5 %) were females and 449 had both VISITECT CD4 test and standard of care. The sensitivity and specificity were; 95.9 % (95 % CI: 91.8 %–98.3 %) and 78.3 % (95 % CI: 73.0 %–83.0 %) respectively. 47 healthcare workers used the VISITECT CD4, of whom 57.5 % were non-laboratory healthcare workers. Majority of the healthcare workers were of the opinion that the training was adequate and VISITECT CD4 was easy and useful in clinical decisions. ConclusionThe VISITECT CD4 test was accurate, useable and acceptable among healthcare workers in Tanzania. The scale up of VISITECT CD4 should consider development of training curriculum and the use of job aids particularly for non-laboratory healthcare workers.

Alterations in cell arrangements of group B streptococcus due to virulence factor expression can bias estimates of bacterial populations based on colony count measures.

Group B streptococcus (GBS) is a chain-forming commensal bacterium and opportunistic pathogen that resides in the gastrointestinal and genitourinary tract of healthy adults. GBS can cause various infections and related complications in pregnant and nonpregnant women, adults, and newborns. Investigations of the mechanisms by which GBS causes disease pathogenesis often utilize colony count assays to estimate bacterial population size in experimental models. In other streptococci, such as group A streptococcus and pneumococcus, variation in the chain length of the bacteria that can occur naturally or due to mutation can affect facets of pathogenesis, such as adherence to or colonization of a host. No studies have reported a relationship between GBS chain length and pathogenicity. Here, we used GBS strain 874391 and several derivative strains displaying longer chain-forming phenotypes (874391pgapC, 874391ΔcovR, 874391Δstp1) to assess the impact of chain length on bacterial population estimates based on the colony-forming unit (c.f.u.) assay. Disruption of GBS chains via bead beating or sonication in conjunction with fluorescence microscopy was used to compare chaining phenotypes pre- and post-disruption to detect long- and short-chain forms, respectively. We used a murine model of GBS colonization of the female reproductive tract to assess whether chaining may affect bacterial colonization dynamics in the host during chronic infection in vivo. Overall, we found that GBS exhibiting long-chain form can significantly affect population size estimates based on the colony count assay. Additionally, we found that the length of chaining of GBS can affect virulence in the reproductive tract colonization model. Collectively, these findings have implications for studies of GBS that utilize colony count assays to measure GBS populations and establish that chain length can affect infection dynamics and disease pathogenesis for this important opportunistic pathogen.

Hsa_circ_0006260 Mediates Trophoblast Function by Fibronectin Type III Domains Containing Protein 5 via Interacting with miR-770-5p.

A series of studies have confirmed the relationship between circular RNAs (circRNAs) and metabolic diseases. Hsa_circ_0006260 has been reported to be lowly expressed in the placenta of gestational diabetes mellitus (GDM) patients, but the underlying mechanism and its biological functions remain obscure. Placental tissues were collected from 37 pregnant women with normal glucose tolerance (NGT) and 37 pregnant women with GDM. Expression changes of hsa_circ_0006260 in placentas and high glucose (HG)-stimulated HTR-8/SVneo cells were detected using real-time quantitative polymerase chain reaction. Cell viability and migration were determined by cell counting and transwell assays, respectively. Measurement of cytokines was done by enzyme-linked immunosorbent assay. Cell apoptosis was estimated by flow cytometry assay. The molecular mechanisms were identified using dual-luciferase reporter and RNA-binding protein immunoprecipitation assays. Hsa_circ_0006260 expression was remarkably lowered in GDM patient-derived placentas and HG-stimulated HTR-8/SVneo cells. Functionally, hsa_circ_0006260 overexpression weakened HG-mediated repression of HTR-8/SVneo cell viability and migration, as well as promotion of HTR-8/SVneo cell inflammatory response and apoptosis. Mechanistically, hsa_circ_0006260 functioned as a miR-770-5p decoy to mediate fibronectin type III domains containing protein 5 (FNDC5) expression. Ectopic expression of miR-770-5p weakened hsa_circ_0006260 overexpression-mediated repression of HG-induced HTR-8/SVneo cell dysfunction. Also, FNDC5 knockdown lessened miR-770-5p overexpression-mediated promotion of HG-induced HTR-8/SVneo cell dysfunction. Our findings manifested a novel mechanism by which hsa_circ_0006260 could lower HG-induced HTR-8/SVneo cell dysfunction by upregulating FNDC5 via binding to miR-770-5p, which shed new light on circRNA mediated GDM pathogenesis.

Long non-coding RNA RAD51-AS1 promotes the tumorigenesis of ovarian cancer by elevating EIF5A2 expression

PurposeThe present study aims to determine the molecular mechanism mediated by RAD51 antisense RNA 1 (RAD51-AS1) in ovarian cancer (OvCA).MethodsThe data associated with RAD51-AS1 in OvCA were obtained from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database. Relative expression of RAD51-AS1 was detected. Determination of cell proliferation, metastasis, and invasion was performed by cell counting, colony formation, would-healing, and transwell invasion assays. Protein levels were detected by western blotting. The molecular mechanism mediated by RAD51-AS1 was predicted by bioinformatics analysis and verified by dual-luciferase reporter assays. Subcutaneous tumorigenesis models were used to confirm the function of RAD51-AS1 in vivo.ResultsData from TCGA and GEO showed that RAD51-AS1 was associated with poor prognosis in OvCA patients and DNA repair, cell cycle, focal adhesion, and apoptosis in SKOV3.ip cells. High levels of RAD51-AS1 were detected in OvCA cells. Overexpressing RAD51-AS1 enhanced the proliferative, invading, and migratory capabilities of OvCA cells in vitro while silencing RAD51-AS1 exhibited the opposite effects. Mechanically, RAD51-AS1 elevated eukaryotic initiation factor 5A2 (EIF5A2) expression as a sponge for microRNA (miR)-140-3p. Finally, the role of RAD51-AS1 was verified by subcutaneous tumorigenesis models.ConclusionRAD51-AS1 promoted OvCA progression by the regulation of the miR-140-3p/EIF5A2 axis, which illustrated the potential therapeutic target for OvCA.

Adipose-derived stem cells derived decellularized extracellular matrix enabled skin regeneration and remodeling.

The tissues or organs derived decellularized extracellular matrix carry immunogenicity and the risk of pathogen transmission, resulting in limited therapeutic effects. The cell derived dECM cultured in vitro can address these potential risks, but its impact on wound remodeling is still unclear. This study aimed to explore the role of decellularized extracellular matrix (dECM) extracted from adipose derived stem cells (ADSCs) in skin regeneration. Methods: ADSCs were extracted from human adipose tissue. Then we cultivated adipose-derived stem cell cells and decellularized ADSC-dECM for freeze-drying. Western blot (WB), enzyme-linked immunosorbent assay (ELISA) and mass spectrometry (MS) were conducted to analyzed the main protein components in ADSC-dECM. The cell counting assay (CCK-8) and scratch assay were used to explore the effects of different concentrations of ADSC-dECM on the proliferation and migration of human keratinocytes cells (HaCaT), human umbilical vein endothelia cells (HUVEC) and human fibroblasts (HFB), respectively. Moreover, we designed a novel ADSC-dECM-CMC patch which used carboxymethylcellulose (CMC) to load with ADSC-dECM; and we further investigated its effect on a mouse full thickness skin wound model. Results: ADSC-dECM was obtained after decellularization of in vitro cultured human ADSCs. Western blot, ELISA and mass spectrometry results showed that ADSC-dECM contained various bioactive molecules, including collagen, elastin, laminin, and various growth factors. CCK-8 and scratch assay showed that ADSC-dECM treatment could significantly promote the proliferation and migration of HaCaT, human umbilical vein endothelia cells, and human fibroblasts, respectively. To evaluate the therapeutic effect on wound healing in vivo, we developed a novel ADSC-dECM-CMC patch and transplanted it into a mouse full-thickness skin wound model. And we found that ADSC-dECM-CMC patch treatment significantly accelerated the wound closure with time. Further histology and immunohistochemistry indicated that ADSC-dECM-CMC patch could promote tissue regeneration, as confirmed via enhanced angiogenesis and high cell proliferative activity. Conclusion: In this study, we developed a novel ADSC-dECM-CMC patch containing multiple bioactive molecules and exhibiting good biocompatibility for skin reconstruction and regeneration. This patch provides a new approach for the use of adipose stem cells in skin tissue engineering.

The Role of Procalcitonin in Neonatal Sepsis-examining Facts and Misconceptions

Background: Neonatal sepsis has remained a major cause of neonatal morbidity and mortality. Despite advances in neonatal diagnostics, its diagnosis has remained challenging majorly because its symptoms are vague and blood culture which remains the gold standard for diagnosis is cumbersome and has poor yield and other forms of sepsis are usually not sought for (anaerobes, viral fungal). The search for newer diagnostic methods is still on going and procalcitonin has shown some promise. Aim/Objective: The aim of the study is to examine the role procalcitonin plays in neonatal sepsis. Materials and Methods: A total of 248 neonates with suspicion of sepsis were enrolled and had their samples taken for blood culture, full blood count, C-reactive and procalcitonin assay based on which the neonates were classified as proven, suspected and clinical sepsis. Result: The behaviour of procalcitonin in the different sepsis groups (more elevated in proven and suspected than clinical), ages (to accommodate the physiologic variation seen in the first 72hours of life) and according to isolates (more elevated in gram negative than gram positive sepsis). The diagnostic value of procalcitonin was also determined and found have sensitivity 74.5%, specificity 38.3%, positive predictive value 42.4% and negative predictive value 71.1%, which were better after >72hours of life. Conclusion: For now, procalcitonin should continue to serve as a supportive marker for sepsis as its levels are affected by age of the neonate, sepsis mimics, and type of offending organism causing the infection.

Biocompatibility of Synechococcus sp. PCC 7002 with Human Dermal Cells In Vitro.

Being the green gold of the future, cyanobacteria have recently attracted considerable interest worldwide. This study investigates the adaptability and biocompatibility of the cyanobacterial strain Synechococcus sp. PCC 7002 with human dermal cells, focusing on its potential application in biomedical contexts. First, we investigated the adaptability of Synechococcus PCC 7002 bacteria to human cell culture conditions. Next, we evaluated the biocompatibility of cyanobacteria with common dermal cells, like 3T3 fibroblasts and HaCaT keratinocytes. Therefore, cells were directly and indirectly cocultured with the corresponding cells, and we measured metabolic activity (AlamarBlue assay) and proliferation (cell count and PicoGreen assay). The lactate dehydrogenase (LDH) assay was performed to determine the cytotoxic effect of cyanobacteria and their nutrition medium on human dermal cells. The cyanobacteria exhibited exponential growth under conventional human cell culture conditions, with the temperature and medium composition not affecting their viability. In addition, the effect of illumination on the proliferation capacity was investigated, showing a significant impact of light exposure on bacterial growth. The measured oxygen production under hypoxic conditions demonstrated a sufficient oxygen supply for further tissue engineering approaches depending on the number of bacteria. There were no significant adverse effects on human cell viability and growth under coculture conditions, whereas the LDH assay assessed signs of cytotoxicity regarding 3T3 fibroblasts after 2 days of coculturing. These negative effects were dismissed after 4 days. The findings highlight the potential of Synechococcus sp. PCC 7002 for integration into biomedical approaches. We found no cytotoxicity of cyanobacteria on 3T3 fibroblasts and HaCaT keratinocytes, thus paving the way for further in vivo studies to assess long-term effects and systemic reactions.

Urocortin-1 promotes colorectal cancer cell migration and proliferation and inhibits apoptosis via inhibition of the p53 signaling pathway

PurposeTo investigate the effect of urocortin-1 (UCN-1) on growth, migration, and apoptosis in colorectal cancer (CRC) in vivo and vitro and the mechanism by which UCN-1 modulates CRC cells in vitro.MethodsThe correlation between UCN-1 and CRC was evaluated using The Cancer Genome Atlas (TCGA) database and a tissue microarray. The expression of UCN-1 in CRC cells was assessed using quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting. In vitro, the influence of UCN-1 on the proliferation, apoptosis, and migration of HT-29, HCT-116, and RKO cells was explored using the celigo cell counting assay or cell counting kit-8 (CCK8), flow cytometry, and wound healing or Transwell assays, respectively. In vivo, the effect of UCN-1 on CRC growth and progression was evaluated in nude mice. The downstream pathway underlying UCN-1-mediated regulation of CRC was determined using the phospho-kinase profiler array in RKO cells. Lentiviruses were used to knockdown or upregulate UCN-1 expression in cells.ResultsBoth the TCGA and tissue microarray results showed that UCN-1 was strongly expressed in the tissues of patients with CRC. Furthermore, the tissue microarray results showed that the expression of UCN-1 was higher in male than in female patients, and high expression of UCN-1 was associated with higher risk of lymphatic metastasis and later pathological stage. UCN-1 knockdown caused a reduction in CRC cell proliferation, migration, and colony formation, as well as an increase in apoptosis. In xenograft experiments, tumors generated from RKO cells with UCN-1 knockdown exhibited reduced volumes and weights. A reduction in the expression of Ki-67 in xenograft tumors indicated that UCN-1 knockdown curbed tumor growth. The human phospho-kinase array showed that the p53 signaling pathway participated in UCN-1-mediated CRC development. The suppression in migration and proliferation caused by UCN-1 knockdown was reversed by inhibitors of p53 signal pathway, while the increase in cell apoptosis was suppressed. On the other hand, overexpression of UCN-1 promoted proliferation and migration and inhibited apoptosis in CRC cells. Overexpression of p53 reversed the effect of UCN-1 overexpression on CRC development.ConclusionUCN-1 promotes migration and proliferation and inhibits apoptosis via inhibition of the p53 signaling pathway.

Oncogenic circ-SLC16A1 promotes progression of non-small cell lung cancer via regulation of the miR-1287-5p/profilin 2 axis

BackgroundCircular RNAs (circRNAs) are single-stranded RNAs with covalently closed structures that have been implicated in cancer progression. However, the regulatory mechanisms remain largely unclear. So, the aim of this study was to reveal the role and regulatory mechanisms of circ-SLC16A1.MethodsIn this study, next-generation sequencing was used to identify abnormally expressed circRNAs between cancerous and para-carcinoma tissues. Fluorescence in situ hybridization and quantitative reverse transcription polymerase chain reaction were performed to assess the expression patterns of circ-solute carrier family 16 member 1 (SLC16A1) in non-small cell lung cancer (NSCLC) cells and tissue specimens. The dual-luciferase reporter assay was utilized to identify downstream targets of circ-SLC16A1. Transwell migration, wound healing, 5-ethynyl-2′-deoxyuridine incorporation, cell counting, and colony formation assays were conducted to assess the proliferation and migration of NSCLC cells. A mouse tumor xenograft model was employed to determine the roles of circ-SLC16A1 in NSCLC progression and metastasis in vivo.ResultsThe results found that circ-SLC16A1 was upregulated in NSCLC cells and tissues. Downregulation of circ-SLC16A1 inhibited tumor growth by reducing proliferation, lung metastasis, and lymphatic metastasis of NSCLC cells, and arrested the cell cycle in the G1 phase. Also, silencing of circ-SLC16A1 promoted apoptosis of NSCLC cells. The results of bioinformatics analysis and the dual-luciferase reporter assay confirmed that microRNA (miR)-1287-5p and profilin 2 (PFN2) are downstream targets of circ-SLC16A1. PFN2 overexpression or circ-SLC16A1 inhibition restored proliferation and migration of NSCLC cells after silencing of circ-SLC16A1. PFN2 overexpression restored migration and proliferation of NSCLC cells post miR-1287-5p overexpression.ConclusionsCollectively, these findings show that miR-1287-5p/PFN2 signaling was associated with downregulation of circ-SLC16A1 and reduced invasion and proliferation of NSCLC cells. So, circ-SLC16A1 is identified as a mediator of multiple pro-oncogenic signaling pathways in NSCLC and can be targeted to suppress tumor progression.

Hypoxia-Challenged Pancreatic Adenocarcinoma Cell-Derived Exosomal circR3HCC1L Drives Tumor Growth Via Upregulating PKM2 Through Sequestering miR-873-5p.

Pancreatic adenocarcinoma (PAAD) is a fatal disease with poor survival. Increasing evidence show that hypoxia-induced exosomes are associated with cancer progression. Here, we aimed to investigate the function of hsa_circ_0007678 (circR3HCC1L) and hypoxic PAAD cell-derived exosomal circR3HCC1L in PAAD progression. Through the exoRBase 2.0 database, we screened for a circular RNA circR3HCC1L related to PAAD. Changes of circR3HCC1L in PAAD samples and cells were analyzed with real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, migration, invasion were analyzed by colony formation, cell counting, and transwell assays. Measurements of glucose uptake and lactate production were done using corresponding kits. Several protein levels were detected by western blotting. The regulation mechanism of circR3HCC1L was verified by dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays. Exosomes were separated by differential ultracentrifugation. Animal experiments were used to verify the function of hypoxia-derived exosomal circR3HCC1L. CircR3HCC1L was upregulated in PAAD samples and hypoxic PAAD cells. Knockdown of circR3HCC1L decreased hypoxia-driven PAAD cell proliferation, migration, invasion, and glycolysis. Hypoxic PAAD cell-derived exosomes had higher levels of circR3HCC1L, hypoxic PAAD cell-derived exosomal circR3HCC1L promoted normoxic cancer cell malignant transformation and glycolysis in vitro and xenograft tumor growth in mouse models in vivo. Mechanistically, circR3HCC1L regulated pyruvate kinase M2 (PKM2) expression via sponging miR-873-5p. Also, PKM2 overexpression or miR-873-5p silencing offset circR3HCC1L knockdown-mediated effects on hypoxia-challenged PAAD cell malignant transformation and glycolysis. Hypoxic PAAD cell-derived exosomal circR3HCC1L facilitated PAAD progression through the miR-873-5p/PKM2 axis, highlighting the contribution of hypoxic PAAD cell-derived exosomal circR3HCC1L in PAAD.

Abstract 3238: Therapeutic targeting of the genome guardian sirtuins in metastatic prostate cancer

Abstract Introduction: The effective treatment paradigm for the lethal form of metastatic prostate cancer (mPCa) remains challenging. Almost all mPCas eventually develops therapy resistance against androgen receptor (AR) inhibitors (e.g., Enzalutamide, Abiraterone) or to poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors (Olaparib, Niraparib, Talazoparib) (HRRd) when used as monotherapy. Although the patients in the ARSi+PARPi combination produced significantly longer radiologic progression-free survival (rPFS), a substantial number had attained therapy resistance by the end of the study tenure. So, a newer therapy is urgently needed. In recent years, a new targetable therapeutics development domain has been unfolding with an expanding understanding of the role of SIRTuins in prostate cancer cell survival, invasion, and progression to an aggressive metastatic state. Here, we will investigate the therapeutic efficacy of SIRT1/7 inhibitor (SIRT1/7i) and determine synergy with DNA-damaging PARP inhibitor combinations through a battery of cell and molecular assays using various prostate cancer cellular models. Methods: We have treated the mPCa cell lines 22Rv1, LAPC4, PC3 and LnCAP as well as prostate epithelial cell line RWPE1 with SIRT1 inhibitor SIRT1-IN-2 (MedChemExpress, HY-146689), SIRT7 inhibitor 97491 (MedChemExpress, HY-135899) and AR inhibitor Enzalutamide individually as well as in combination of PARP inhibitor Olaparib. The treatment of the SIRT1 and SIRT7 monotherapy arm was 72 hours long, and combination therapy continued for 7 days. The cell viability was assessed with CellTiter-Glo® 2.0 Cell Viability Assay (Promega). The cell cycle progression and proliferation analysis were done using flow cytometry through Propidium iodide staining and AnnexinV-FITC apoptosis detection chemistry. Cell survival was orthogonally assessed using colony counting assays. We adopt RAD51 foci counting assays and COMET assays for evaluating treatment-induced genome instability. Results: The preliminary result suggested that the SIRT1i+Olaparib and SIRT7i+Olaparib combination significantly sensitized the mPCa cell lines 22Rv1, PC3, and LnCAP for cell death compared to the prostate epithelial cell RWPE1. Upon the combination treatment, the mPCa cell lines showed elevated apoptotic cell death, reconfirmed through colony counting assay. Conclusion: Therapeutic combination treatment of SIRT1 and SIRT7 inhibition with Olaparib could be an effective treatment option for aggressive metastatic prostate cancer. Citation Format: Subhajit Giri. Therapeutic targeting of the genome guardian sirtuins in metastatic prostate cancer [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 3238.

Abstract 7219: Preclinical investigations of concomitant tumor treating fields (TTFields) with cisplatin for treatment of cervical cancer

Abstract Introduction: Cervical cancer, although largely preventable, continues to be a significant health concern. Early-stage treatment is commonly surgery; while advanced, recurrent, or metastatic disease often requires systemic therapy. Chemotherapy, mainly cisplatin is the backbone of first-line therapy. TTFields are electric fields that disrupt cellular processes critical for cancer cell viability and tumor progression. In other tumor types, TTFields applied with cisplatin has exhibited benefit. This in vitro study assessed the preclinical efficacy of TTFields for cervical cancer and explored efficacy for concurrent use with cisplatin. Methods: Effects on cell count in cervical cancer cell lines exposed to TTFields (0.5 V/cm for Ca Ski cells, 1 V/cm RMS for HeLa and SiHa cells; 72 h) across a range of frequencies (100-400 kHz) were evaluated. TTFields (200 kHz) were then applied with varying cisplatin doses followed by cell count, colony formation, and apoptosis assays. Overall effect was calculated as the product of percent reductions in cell count and colony formation. TTFields-treated cells were evaluated for formation of the DNA damage marker γH2AX using fluorescent microscopy; and for the expression of Fanconi Anemia (FA)-BRCA pathway proteins through Western blotting. Results: TTFields treatment reduced cell count in all cervical cancer cell lines tested. Cisplatin exhibited dose-response effects, which were enhanced when TTFields were co-applied. TTFields led to downregulated expression of FA-BRCA pathway proteins, which are involved in repairing cisplatin-induced DNA damage, resulting in increased DNA damage. Conclusions: These preclinical results suggest that TTFields should be further explored as a potential treatment for cervical cancer. TTFields-induced downregulation of the FA-BRCA pathway possibly explains the enhanced efficacy when TTFields are applied together with cisplatin, providing mechanistic insight. Citation Format: Roni Frechtel-Gerzi, Daria Gerasimova, Einav Zeevi, Roni Monin, Hila Fishman, Inbar Schlachet-Drukerman, Helena Mumblat, Antonia Martinez-Conde, Rotem Engelman, Eyal Dor-On, Itai Tzchori, Adi Haber, Moshe Giladi, Uri Weinberg, Yoram Palti, Greg M. Palmer, Angeles Alvarez Secord. Preclinical investigations of concomitant tumor treating fields (TTFields) with cisplatin for treatment of cervical cancer [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 7219.

Abstract 1668: Association of stem cell-like phenotype with isoform specific functions of AKTs in hepatocytes

Abstract Introduction: Liver cancer is the sixth most common cancer and the third leading cause of cancer-related deaths worldwide. It is associated with abnormal activation of the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which is implicated in regulation of cancer stem cells (CSCs). The present study investigated the effects of AKT loss on stem cell-like phenotype in immortalized mouse hepatocytes. Methods: Immortalized hepatocytes were established from mice with Akt1 (Akt1−/−; Akt1-null) or Akt2 (Akt2−/−; Akt2-null) whole-body deletion. Cell morphology was assessed via microscopy. Cell proliferation was evaluated with hemacytometer count and MTT assay. Cell migration towards a chemoattractant was assessed via transwell assay. Cell viability was evaluated in response to chemotherapy treatment. The ability of cells to Results: When compared to WT cells, which exhibited cuboidal epithelial-like features, Akt1-null and Akt2-null cells demonstrated elongated mesenchymal-like morphology. Loss of either isoform was associated with a significantly decreased cell growth (p<0.05). Akt1-null cells migrated faster towards a chemoattractant in the transwell assay, were significantly more resistant to sorafenib, and formed a significantly higher number of spheres in the sphere formation assay (p<0.01). Proteomic analysis revealed that both Akt1-null and Akt2-null cells exhibited increased expression of CSC marker CD44, along with other proteins associated with liver cancer, including PDGFRA, CDH2, MMP14, and COX2 (p<0.05). Additionally, Akt1-null cells exhibited elevated levels of ANXA1 and ANXA3 (p<0.01). Conclusions: Loss of both AKT isoforms resulted in decreased cell proliferation and elevated expression of proteins with a previously reported role in liver cancer invasion, migration, and epithelial-mesenchymal transition. AKT1 loss correlated with an enhanced stem cell-like phenotype, including increased migration towards a chemoattractant, higher resistance to chemotherapy, and enhanced ability to form spheres. These results contribute to the understanding of the role of AKT isoforms in regulating stemness in liver cancer and may serve as a basis for investigation into isoform specific inhibitors. Further investigation into cellular mechanisms governing these phenotypes is required. Citation Format: Ielyzaveta Slarve, Yushan Wang, Mario Alba, Lina He, Bangyan Stiles. Association of stem cell-like phenotype with isoform specific functions of AKTs in hepatocytes [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 1668.

Abstract 2363: Enhanced T cell activation and cytotoxicity against AML via targeted anti-CD99-A192 ScFv-ELP nanoparticle treatment

Abstract CD99 is a transmembrane protein overexpressed in acute myeloid leukemia (AML), presenting a potential novel therapeutic target. Our previously developed anti-CD99-A192, comprising scFv and elastin-like polypeptides (ELPs), showed promising anti-leukemic activity by inducing apoptosis in AML cell lines and prolonging survival in AML xenograft models. Considering CD99's expression and role in T cell activation, we proposed that anti-CD99-A192 could have a dual function: targeting leukemic cells while activating T cells. Blood samples were obtained from 20 healthy donors, and peripheral blood mononuclear cells (PBMCs) were isolated and stimulated with PHA and IL-2 cytokines to expand T cells for 72-96 hours. Post-expansion, T cells were treated with either anti-CD99-A192 or control anti-A192. Proliferation was evaluated via cell count and cell trace assays. The percentages of CD4+, CD8+, and CD25+ T cells, and the levels of T cell activation markers CD69 and CD38, were quantified by flow cytometry. Cytokine release profiles were assessed by the Proteome Profiler Human Cytokine Array Kit. The cytotoxic impact of the anti-CD99-A192-activated T cells on MV4-11Luc+ AML cells was measured in co-culture apoptosis and luciferase assays. Statistical comparisons utilized paired and unpaired T-tests with Holm-Sidak correction for multiple comparisons, and P value <0.05 was considered significant. T cells treated with anti-CD99-A192 displayed significant increased proliferation compared with untreated and anti-A192-treated groups at Day 5 (163.3% vs. 97% and 92.4%, p=0.042 and p=0.03, respectively). The percentage of CD4+, CD8+, and CD25+ cells remained unchanged across treated and control groups. Activation marker analysis revealed increase in % CD38+ cells in the anti-CD99-A192 group compared with the control (58.15% vs. 49.15%, p=0.0028). Among the cytokine panel, significant increases in IL-1β/IL-1F2 (11-fold change, p<0.001, adjusted p=0.006) and TNF-α (12-fold change, p=0.002, adjusted p=0.03) were observed, along with a marked decrease in IL-8 (70% reduction, p<0.001, adjusted p=0.001). GM-CSF (20-fold change, p=0.005, adjusted p=0.071) and IL-16 (2-fold change, p=0.003, adjusted p=0.051) levels also increased, though not significantly after adjustment. Co-culture assays showed greater apoptosis in MV4-11 cells at 18 hours (33.6% vs. 41.13%, p=0.015) and a reduction in viable leukemic cells at 18 hours (10.89% vs. 8.05%, p=0.034) and 48 hours (9.69% vs. 6.54%, p=0.065) in the anti-CD99-A192 compared with the control group, results were also validated by the luciferase assay (~32% reduction, p<0.001). Anti-CD99-A192 scFv-ELP nanoparticle stimulates T cell proliferation, elevates activation markers, and increases the release of pro-inflammatory cytokines. Anti-CD99-A192 culminates in heightened cytotoxicity against leukemic cells. Citation Format: Shephali Kadam, Atham Ali, Mateusz Pospiech, Sandra Onyemaechi, Yiting Meng, Kanaka Dhuri, Andrew Mackay, Houda Alachkar. Enhanced T cell activation and cytotoxicity against AML via targeted anti-CD99-A192 ScFv-ELP nanoparticle treatment [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 2363.

Abstract 5909: Sulindac exhibits anti-proliferative effects in pre-clinical models of ovarian cancer

Abstract Objectives: Given the intricate relationship between inflammation and ovarian cancer (OC) development and progression, anti-inflammatory drugs may have potential in the prevention and treatment of OC. Sulindac exhibits potent anti-inflammatory effects through inhibition of COX1/COX2 pathways and promising anti-tumor activity in pre-clinical models of colorectal and endometrial cancer. Thus, we investigated the efficacy of sulindac as an anti-tumorigenic agent in OC pre-clinical cell and mouse models. Methods: The human OC cell lines, MES and OVCAR5, and the K18-gT121+/-;p53fl/fl;Brca1fl/fl (KpB) mouse model of high-grade serous OC were used. Cellular proliferation was assessed by MTT and colony count assays. Apoptosis was assessed using cleaved caspase 3, 8, and 9 assays. To measure cellular stress, production of reactive oxygen species was measured by DCFH-DA assay, and the JC1 assay was used to assess changes in mitochondrial membrane potential. Cellular adhesion was evaluated by laminin assay, and cellular migration was determined by wound healing assay. Western immunoblotting was used to assess the effects of sulindac on downstream targets related to cellular stress, apoptosis, cellular invasion potential, cell cycle control, and inflammation. The KpB mice were treated with sulindac (7.5 mg/kg, oral gavage, daily) or placebo for four weeks. Results: Sulindac inhibited cellular proliferation in a dose-dependent manner in the MES and OVCAR5 cells, with IC50s of 75.3 and 75.69 μM, respectively. Sulindac (100 μM) reduced colony formation by 81% in the MES cells and by 49% in the OVCAR5 cells (p<0.01). Treatment of MES and OVCAR5 cells with sulindac increased ROS production and decreased mitochondrial membrane potential, in a dose-dependent manner (p<0.01). Sulindac induced activity of cleaved caspase 3, 8, and 9, in MES and OVCAR5 cells (p<0.01). In addition, sulindac (100 μM) effectively decreased cellular adhesion by 31% in MES cells and by 23% in OVCAR5 cells (p<0.01). These results were confirmed by Western immunoblotting demonstrating that sulindac downregulated the anti-apoptotic proteins Bcl-xl and Mcl-1 and upregulated the pro-apoptotic proteins Bax and cellular stress proteins Bip, ATF-4, and PDI, in both cell lines. Sulindac downregulated expression of several epithelial-mesenchymal transition proteins in both cell lines, including beta-catenin, snail, and slug. Sulindac also downregulated expression of cell cycle proteins CDK4, CDK5, and Cyclin D1 and inflammatory protein COX-2 in both cell lines. After 4 wks of treatment, sulindac significantly inhibited tumor growth by 71% (1.89 g vs 0.54 g, p<0.01) in KpB mice. Conclusions: Our results find that sulindac exhibited anti-tumorigenic effects in OC cell lines and the KpB OC mouse model. Given these promising pre-clinical results, further studies on the repurposing of sulindac for the prevention and treatment of OC is warranted. Citation Format: Nikita Sinha, Shuning Chen, Jennifer Haag, Xiaochang Shen, Boer Deng, Ziyi Zhao, Chunxiao Zhou, Victoria Bae-Jump. Sulindac exhibits anti-proliferative effects in pre-clinical models of ovarian cancer [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 5909.

Role of ArcA in the regulation of antibiotic sensitivity in avian pathogenic Escherichia coli

Avian pathogenic Escherichia coli (APEC) is one of the common extraintestinal infectious disease pathogens in chickens, geese, and other birds, inducing serious impediments to the development of the poultry industry. Hence, investigating how bacteria regulate themselves amidst different challenging conditions is immense essential in prevention and treatment for bacterial pathogen infections. The ArcA regulatory factor has been reported to regulate oxygen availability in strains, but its role in regulation of antibiotics resistance in APEC is unclear. This study delved into understanding how ArcA regulates antibiotic resistance in APEC. An E. coli APEC40 arcA knockout strain was constructed, and the regulatory mechanism of arcA on APEC antibiotic susceptibility was identified by drug sensitivity test, colony counting assay, real-time quantitative PCR, β-galactosidase assays and electrophoretic mobility shift assay (EMSA). The results showed that ArcA directly binds to the promoter region of the outer membrane protein OmpC/OmpW and regulates bacterial susceptibility to kanamycin and penicillin G. At the same time, the double knockout of ompW and ompW/arcA resulted in an increase in resistance to kanamycin compared to the deletion of the arcA gene. This outcome provided experimental proof suggesting that the outer membrane protein OmpW could serve as a crucial pathway for the ingress of kanamycin into cells. These results confirmed the important regulatory role of ArcA transcription factors under APEC antibiotic stress.

Citrus sunki Peel Extract, Containing Nobiletin and Tangeretin, Enhances Proliferation and Differentiation in 3T3-L1 Adipocytes

In this experiment, effects of Citrus sunki peel extract (CPE) on proliferation and differentiation of 3T3-L1 cells were analyzed. Citrus sunki peel was extracted with ethanol to obtain CPE. Results of measuring DPPH and hydrogen peroxide radical scavenging activity revealed that CPE had an antioxidant ability. The 3T3-L1 cells were cultured in the basal medium (C) or with 0.05% dimethyl-sulfoxide (CDMSO) or with 50, 100, 200, 300, and 400 μg/mL CPE (CPE50, CPE100, CPE200, CPE300, and CPE400, respectively). As a result of cell counting and MTS assay, CPE significantly enhanced proliferation capacity of 3T3-L1 cells. To analyze the effect of CPE on the differentiation capacity of 3T3-L1 cells, relative gene and protein expression levels of Cebpb, Cebpa, and FASN related to adipogenesis were measured by RT-qPCR and Western blot. CPE increased adipogenesis-related gene and protein expression in 3T3-L1 cells, with CPE300 being especially effective. In Oil Red O staining, adipogenesis was significantly greater in CPE200, CPE300, and CPE400 than in C. This was confirmed image wise through Nile Red staining. Through HPLC analysis, it was confirmed that nobiletin and tangeretin were most abundant in CPE. To analyze effects of nobiletin and tangeretin on 3T3-L1 cells, the cells were cultured with various concentrations of nobiletin, tangeretin, and both. As a result of cell counting and MTS assay, nobiletin and tangeretin significantly decreased the proliferation capacity of 3T3-L1 cells. In RT-qPCR, western blot, Oil Red O staining, and Nile Red staining to analyze differentiation capacity, nobiletin and tangeretin significantly enhanced the expression of genes and proteins related to adipogenic differentiation compared to the control group. In conclusion, CPE, which had high antioxidant capacity, enhanced proliferation and differentiation in 3T3-L1 adipocytes. This improvement in differentiation is due to the influence of nobiletin and tangeretin contained in CPE.