Whole-exome sequencing identifies cancer-associated variants of the endo-lysosomal ion transport channels in the Saudi population

Background

Although national efforts are underway to document the genomic variability of the Saudi population relative to other populations, such variability remains largely unexplored. Genetic variability is known to impact the fate of cells and increase or decrease the risk of a variety of complex diseases including cancer forms. Therefore, the identification of variants associated with cancer susceptibility in Saudi population may protect individuals from cancer or aid in patient-tailored therapies. The endo-lysosomal ion transport genes responsible for cationic ion homeostasis within the cell. We screened 703 single-nucleotide polymorphisms (SNPs) of the endo-lysosomal ion transporter genes in the Saudi population and identified cancer-associated variants that have been reported in other populations.

Methods

Utilizing previously derived local data of Whole-Exome Sequencing (WES), we examined SNPs of TPCN1, TPCN2, P2RX4, TRPM7, TRPV4, TRPV4, and TRPV6 genes. The SNPs were identified for those genes by our in-house database. We predicted the pathogenicity of these variants using in silico tools CADD, Polyphen-2, SIFT, PrimateAI, and FATHMM-XF. Then, we validated our findings by exploring the genetics database (VarSome, dbSNP NCB, OMIM, ClinVar, Ensembl, and GWAS Catalog) to further link cancer risk.

Results

The WES database yielded 703 SNPs found in TPCN2, P2RX4, TRPM7, TRPV4, and TRPV6 genes in 1,144 subjects. The number of variants that were found to be common in our population was 150 SNPs. We identified 13 coding-region non-synonymous variants of the endo-lysosomal genes that were most common with a minor allele frequency (MAF) of ≥ 1 %. Twelve of these variants are rs2376558, rs3750965, rs61746574, rs35264875, rs3829241, rs72928978, rs25644, rs8042919, rs17881456, rs4987682, rs4987667, and rs4987657 that were classified as cancer-associated genes.

Conclusion

Our study highlighted cancer-associated SNPs in the endo-lysosomal genes among Saudi individuals. The allelic frequencies on polymorphic variants confer susceptibility to complex diseases that are comparable to other populations. There is currently insufficient clinical data supporting the link between these SNPs and cancer risk in the Saudi population. Our data argues for initiating future cohort studies in which individuals with the identified SNPs are monitored and assessed for their likelihood of developing malignancies and therapy outcomes.

The effect of inhibiting hindbrain A2 noradrenergic neurons by 6-Hydroxydopamine on lipopolysaccharide-treated male rats autistic animal model

Autism spectrum disorder (ASD) is a complex neurodevelopmental illness that often emerges in early childhood. The incidence of ASD has shown a notable rise in recent years. ASD is defined by deficits in social communication, and presence of rigid and repetitive behaviors and interests. The underlying mechanisms of ASD remain elusive. Multiple studies have documented the presence of neuroinflammation and increased levels of inflammatory cytokines, specifically, IL-6, TNF, and NF-κB, in various brain regions, including the prefrontal cortex (PFC) and hippocampus in individuals with ASD. Noradrenergic neurons play a crucial role in brain development and the regulation of motor, behavioral, and memory functions. This study sought to examine the impact of intracerebroventricular (icv.) injection of the neurotoxin, 6-hydroxydopamine (6-OHDA), in the caudal dorsal vagal complex A2 neurons on various neuroinflammatory pathways at the hippocampus and PFC in valproic acid (VPA) autistic animal model. This was done in conjunction with an intraperitoneal (i.p.) injection of Lipopolysaccharides (LPS) in animal models with VPA-induced autism. We specifically examined the impact of the caudal fourth ventricle 6-OHDA icv. injection and LPS (i.p.) injection on self-grooming behavior. We measured the mRNA expression of IL-6, TNF-a, and NF-κB using qRT-PCR, and the protein expression of COX-2, GPX-1, p-AMPK, and AMPK using western blot analysis. The self-grooming activity was considerably higher in the combined treatment group (6-OHDA icv. + LPS i.p.) compared to the control group. A substantial increase observed in the expression of IL-6, TNF-α, and NF-κB genes in the PFC of the treatment group that received icv. Administration of 6-OHDA, compared to the control group. The VPA-autism rats that received the combo treatment exhibited a slight increase in the expression level of NF-κB gene in the hippocampus, compared to the control group. At the PFC, we noticed a substantial drop in the expression of the antioxidant protein GPX-1 in the group that received the combo treatment compared to the control group. Our data investigates a novel aspect that the 6-OHDA-induced inhibition of hindbrain A2 neurons could be influencing the neuroinflammatory pathways in the PFC and hippocampus of autistic animal models.

Cobalt-modulated dual emission carbon dots for ratiometric fluorescent vancomycin detection

This work presents a simple yet selective fluorometric protocol for the quantification of vancomycin, an important antibiotic for treating infections caused by Gram-positive bacteria. A novel ratiometric fluorometric method for the determination of vancomycin is developed based on dual emissive carbon dots (DECDs) with emission at 382 nm and 570 nm in combination with Co2+ ions. Upon addition of Co2+ions, the fluorescence at 382 nm of DECDs is enhanced while emission at 570 nm remains constant. In the presence of vancomycin, it complexes with Co2+ leading to quenching of the 382 nm fluorescence due to strong binding with Co2+ in the Co@DECDs system. The DECDs are fully characterized by TEM and different spectroscopic techniques. The proposed ratiometric method is based on measuring fluorescence ratio (F570/F382) against vancomycin concentration and the method exhibits a good linearity range from 0.0 to 120.0 ng mL-1 with a low limit of detection (S/N = 3) of 0.31 ng mL-1. The method shows good selectivity with minimal interference from potential interfering species. This ratiometric fluorometric approach provides a promising tool for sensitive and specific vancomycin detection in clinical applications.

Selective and reliable fluorometric quantitation of anti-cancer drug in real plasma samples using nitrogen-doped carbon dots after MMIPs solid phase microextraction: Monitoring methotrexate plasma level

A novel selective and reliable ratiometric fluorescence probe has been successfully synthesized for precise, sensitive, and simple quantitation of methotrexate (MTX). Hydrothermal method was employed to fabricate nitrogen-doped carbon dots using Annona squamosa seeds (AS-CDs) as a starting material, and their characteristics were confirmed using transmission electron microscopy (TEM), UV-Vis spectroscopy, fluorescence spectroscopy, X-ray diffractometry (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). The ratiometric fluorometric assay, which is based on measuring the ratio of emissions (F355/F430), has a wide detection range of 5-2000 ng /mL and a limit of detection (LOD, S/N = 3) of 1.5 ng /mL. The developed sensing method was successfully applied to the quantification of MTX in rabbit plasma samples and parenteral formulations, achieving satisfactory recoveries %. Magnetic molecularly imprinted solid-phase microextraction was used for selective extraction of MTX from plasma samples. The pharmacokinetic parameters were successfully determined in real rabbit plasma samples after intravenous administration of MTX. The as-designed probe does not only improve the sensitivity, but also enhances the precision and accuracy of the proposed method. Overall, this study presents a promising approach for the detection of MTX in genuine samples with acceptable degree of selectivity and sensitivity.

Selective fluorescence turn-on detection of combination cisplatin-etoposide chemotherapy based on N-CDs/GSH-CuNCs nanoprobe

Cisplatin (CIS) and etoposide (ETP) combination therapy is highly effective for treating various cancers. However, the potential for pharmacokinetic interactions between these drugs necessitates selective sensing methods to quantitate both CIS and ETP levels in patient's plasma. This work develops a dual fluorescence probe strategy using glutathione-capped copper nanoclusters (GSH-CuNCs) and nitrogen-doped carbon dots (N-CDs) for the simultaneous analysis of CIS and ETP. The fluorescence signal of GSH-CuNCs at 615 nm increased linearly with CIS concentration while the N-CD emission at 480 nm remained unaffected. Conversely, the N-CD fluorescence was selectively enhanced by ETP with no interference with the CuNC fluorescence. Extensive materials characterization including UV-vis, fluorescence spectroscopy, XRD, and TEM confirmed the synthesis of the nanoprobes. The sensor showed high sensitivity with limits of detection of 6.95 ng mL-1 for CIS and 7.63 ng mL-1 for ETP along with excellent selectivity against potential interferences in rabbit plasma. Method feasibility was demonstrated with application to real rabbit plasma samples. The method was further applied to estimate the pharmacokinetic parameters of CIS before and after ETP coadministration. The dual nanoprobe sensing strategy enables rapid and selective quantitation of CIS and ETP levels to facilitate therapeutic drug monitoring and optimization of combination chemotherapy regimens.

Worsening of imiquimod-induced psoriasiform inflammation in mice by environmental pollutant, di-(2-ethylhexyl) phthalate through dysregulation in IL-17A and Nrf2/iNOS signaling in peripheral myeloid and CD4 + T cells

Psoriasis is a devastating autoimmune illness resulting from excessive keratinocyte growth and leukocyte infiltration into the dermis/epidermis. In the pathogenesis of psoriasis, different immune cells such as myeloid cells and CD4 + T cells play a key role. Th17/Th1 immune responses and oxidant-antioxidant responses are critical in regulation of psoriatic inflammation. Di-2-ethylhexyl phthalate (DEHP) is one of the well-known plasticizers and has widespread use worldwide. DEHP exposure through ingestion may produce harmful effects on the skin through systemic inflammation and oxidative stress, which may modify psoriatic inflammation. However, the effect of oral DEHP exposure on inflammatory cytokines and Nrf2/iNOS signaling in myeloid cells and CD4 + T cells in the context of psoriatic inflammation has not been investigated earlier. Therefore, this study explored the effect of DEHP on systemic inflammation in myeloid cells (IL-6, IL-17A, IL-23), Th17 (p-STAT3, IL-17A, IL-23R, TNF-α), Th1 (IFN-γ), Treg (Foxp3, IL-10), and Nrf2/iNOS signaling in imiquimod (IMQ)-induced mouse model of psoriasis-like inflammation. Our study showed increased Th17 signaling in imiquimod model which was further aggravated by DEHP exposure. Further, Nrf2 and iNOS signaling were also elevated in IMQ model where DEHP exposure further increased iNOS expression but did not modify the Nrf2 expression. Most importantly, IL-17A levels were also elevated in myeloid cells along with IL-6 which were further elevated by DEHP exposure. Overall, this study shows that IL-17A signaling is upregulated, whereas there is deficiency of Nrf2/HO-1 signaling by DEHP exposure in mice with psoriasiform inflammation. These observations suggest that DEHP aggravates IL-17A-mediated signaling both in CD4 + T cells as well as myeloid cells which is linked to exacerbation of IMQ-induced psoriatic inflammation in mice. Strategies that counteract the effect of DEHP exposure in the context of psoriatic inflammation through downregulation of IL-17A may be fruitful.

Loss of two-pore channel 2 function in melanoma-derived tumours reduces tumour growth in vivo but greatly increases tumour-related toxicity in the organism

BACKGROUND

Melanoma, a severe form of skin cancer, poses significant health risks due to its aggressive nature and potential for metastasis. The role of two-pore channel 2 (TPC2) in the development and progression of melanoma remains poorly understood. This study aims to investigate the impact of TPC2 knockout (KO) on melanoma-derived tumors, focusing on tumour growth and related toxicity in the organism.

METHODS

The study utilized CHL-1 and B16 melanoma cell lines with TPC2 KO to assess the changes in proliferation dynamics. Methods included real-time monitoring of cell proliferation using the xCELLigence system, in vivo tumour growth assays in mice, histopathological analyses, inflammation marker assessment, and quantitative PCR (qPCR) for gene expression analysis RESULTS: TPC2 KO was found to significantly alter the proliferation dynamics of CHL-1 and B16 melanoma cells. The in vivo studies demonstrated reduced tumor growth in TPC2 KO cell-derived tumors. However, a notable increase in tumor-related toxicity in affected organs, such as the liver and spleen, was observed, indicating a complex role of TPC2 in melanoma pathology.

CONCLUSIONS

The loss of TPC2 function in melanoma cells leads to reduced tumour growth but exacerbates tumour-related toxicity in the organism. These findings highlight the dual role of TPC2 in melanoma progression and its potential as a therapeutic target. Further research is needed to fully understand the mechanisms underlying these effects and to explore TPC2 as a treatment target in melanoma.

The Combination of Radiation with PARP Inhibition Enhances Senescence and Sensitivity to the Senolytic, Navitoclax, in Triple Negative Breast Tumor Cells

Despite significant advances in the treatment of triple-negative breast cancer, this disease continues to pose a clinical challenge, with many patients ultimately suffering from relapse. Tumor cells that recover after entering into a state of senescence after chemotherapy or radiation have been shown to develop a more aggressive phenotype, and to contribute to disease recurrence. By combining the PARP inhibitor (PARPi), talazoparib, with radiation, senescence was enhanced in 4T1 and MDA-MB-231 triple-negative breast cancer cell lines (based on SA-β-gal upregulation, increased expression of CDKN1A and the senescence-associated secretory phenotype (SASP) marker, IL6). Subsequent treatment of the radiation- and talazoparib-induced senescent 4T1 and MDA-MB231 cells with navitoclax (ABT-263) resulted in significant apoptotic cell death. In immunocompetent tumor-bearing mice, navitoclax exerted a modest growth inhibitory effect when used alone, but dramatically interfered with the recovery of 4T1-derived tumors induced into senescence with ionizing radiation and talazoparib. These findings support the potential utility of a senolytic strategy in combination with the radiotherapy/PARPi combination to mitigate the risk of disease recurrence in triple-negative breast cancer.

BALB/c and C57BL/6 mice differ in oxidant and antioxidant responses in innate and adaptive immune cells in an asthma model induced by cockroach allergens

Asthma is a complex and heterogenous disease affected by a multitude of factors. Several phenotypes of asthma exist which are influenced by various molecular mechanisms that include presence of antioxidant and oxidant enzymes in different immune cells such as dendritic cells (DCs), alveolar macrophages (AMs), neutrophils, and T cells. Close interaction between epithelial cells and dendritic cells initiates complex pathogenesis of asthma followed by involvement of other innate and adaptive immune cells. In chronic phase of the disease, these immune cells support each other in amplification of airway inflammation where oxidant-antioxidant balance is known to be an important contributing factor. Genetic variability in antioxidant response may influence the development of airway inflammation, however it has not been studied in mice yet. The two most studied mice strains, i.e. BALB/c and C57BL/6 are reported to have dissimilar airway responses to the same allergens due to their genetic makeup. In this investigation, we explored whether these strains had any differences in pulmonary oxidant-antioxidant system (Nrf2, SOD2, iNOS, HO-1, nitrotyrosine) in different immune cells (DCs, AMs, neutrophils, T cells), airway inflammation (presence of eosinophils and/or neutrophils) and mucus production in response to repeated cockroach allergen extract (CE) mouse model of asthma. Our data show that C57BL/6 mice had better induction of antioxidant system than BALB/c mice. Consequently, iNOS/nitrotyrosine levels were much exaggerated in BALB/c than C57BL/6 mice. As a result, BALB/c mice developed mixed granulocytic airway inflammation, whereas C57BL/6 developed mostly eosinophilic airway inflammation. Our data suggest that an exaggerated oxidant generation along with a weak antioxidant induction in response to a natural allergen on a susceptible genetic background may determine development of severe asthma phenotype such as mixed granulocyte inflammation.

Examining the Effects of Dasatinib, Sorafenib, and Nilotinib on Vascular Smooth Muscle Cells: Insights into Proliferation, Migration, and Gene Expression Dynamics

BACKGROUND

Dasatinib, nilotinib, and sorafenib are clinically proven tyrosine kinase inhibitors (TKIs) used for the treatment of leukemia and hepatocellular carcinoma. However, there is a growing concern regarding cardiotoxicity associated with their use. The impact of these TKIs on vascular smooth muscle cells (VSMCs) remains unexplored. This study aims to investigate the effects of TKIs on VSMC proliferation and migration, as well as to elucidate the underlying mechanisms involving inflammatory and apoptotic pathways.

METHODS

VSMCs were extracted from albino rats and cultured in vitro. The cells were divided into four experimental groups: control, dasatinib, sorafenib, and nilotinib. The MTT assay was employed to assess the cytotoxic effects of TKIs on VSMCs. A scratch assay was conducted to evaluate the inhibitory potential of TKIs on VSMC migration. Flow cytometry analysis was used to detect apoptotic cells. Real-Time PCR expression was utilized to determine the differential gene expression of apoptotic and inflammatory markers.

RESULTS

Dasatinib, nilotinib, and sorafenib demonstrated significant inhibitory effects on VSMC viability and migration at low concentrations (<1 µmol/L, p < 0.05). Furthermore, gene expression analysis revealed up-regulation of inflammatory biomarkers (TNF-α, IL-6, and IL-1β) and apoptotic markers (P53, BAX), along with down-regulation of the anti-apoptotic biomarker BCL-2 in response to all TKIs.

CONCLUSIONS

This study demonstrates that dasatinib, nilotinib, and sorafenib inhibit VSMC proliferation and migration, suggesting their potential to induce vascular injury and remodeling by activating inflammation and apoptosis pathways. These findings highlight the need for further investigation into the cardiotoxic effects of these TKIs and the development of strategies to mitigate their adverse vascular effects.

A novel microextraction technique aided by air agitation using a natural hydrophobic deep eutectic solvent for the extraction of fluvastatin and empagliflozin from plasma samples: application to pharmacokinetic and drug-drug interaction study

This study focuses on the interaction between the antihyperlipidemic drug fluvastatin (FLV) and the antidiabetic drug empagliflozin (EMP), which are commonly co-administered medications. EMP's impact on FLV levels is attributed to its inhibition of organic anion transporting polypeptide 1B1 (OATP1B1), responsible for FLV liver uptake, consequently elevating FLV concentrations in blood. Traditional extraction methods for FLV faced difficulties due to its high hydrophobicity. In this study, a hydrophobic natural deep eutectic solvent (NDES) using air assisted dispersive liquid-liquid microextraction (AA-DLLME) was utilized as an excellent choice for achieving the highest extraction recovery, reaching 96% for FLV and 92% for EMP. The NDES was created through the combination of menthol and hippuric acid in a 4 : 1 ratio, making it a green and cost-effective pathway. Liquid phase microextraction followed by spectrofluorometric measurements of FLV at λem = 395 nm and EMP at λem = 303 nm, with excitation at a single wavelength of 275 nm was carried out. Response surface methodology (RSM) relying on central composite design (CCD) was used to optimize the variables affecting the AA-NDES-DLLME. The optimized conditions for extraction are: NDES volume of 200 μL, centrifugation time of 15 minutes, air-agitation cycle of 6 cycles, and sample pH of 4.0. Under these optimized conditions, the developed method exhibited good linearity and precision. The method showed good recoveries from rabbit plasma samples spiked at varying concentrations of the analyzed compounds. To assess the applicability and effectiveness of the hydrophobic DES, the validated method was applied to extract the studied drugs from rabbit plasma samples after oral administration of FLV alone and in combination with EMP. The pharmacokinetic parameters of FLV were calculated in both cases to investigate any changes and determine the need for dose adjustment.

Augmented antitumor effects of erlotinib and cabozantinib on A549 non-small cell lung cancer: In vitro and in vivo studies

Non-small cell lung carcinoma is a challenging disease worldwide. This study aims to determine whether combining erlotinib, an epidermal growth factor receptor (EGFR) inhibitor, with cabozantinib, a mesenchymal-epithelial transition factor (c-Met) inhibitor, would have an augmented therapeutic benefit on A549 cells. The combination of erlotinib and cabozantinib (5 µM) inhibited A549 cell viability compared to each monotherapy at ≥ 10 µM as confirmed by the MTT assay. Combination therapy also has a more potent inhibition of cellular migration than monotherapy using the wound-healing assay. Furthermore, mRNA expression analyses for assessing apoptosis, metastasis, and cell cycle-related genes, the results showed that combination therapy significantly inhibits levels of BCL-2, MMP-9, VEGF, and TGF-β while inducing p53, p21, and BAX expression. In terms of oncogenic markers, western blotting analysis showed a significant reduction of BCl-2 expression and elevation in caspase3, p53, and p21 proteins as indicators of cell death via apoptosis. The antitumor in vivo effect of the combination therapy showed significant tumor inhibition compared to monotherapy. In conclusion, combination therapy could be a potential promising strategy to treat non-small cell lung carcinoma.

A selective dual quenching sensor (EY/BG@CDs) for simultaneous monitoring of gentamicin and ketorolac levels in plasma: a highly efficient platform that caters to the needs of therapeutic drug monitoring

This research work introduces a novel sensor that utilizes two fluorophores to enable simultaneous monitoring of gentamicin sulphate (GNT) and ketorolac tromethamine (KET). The innovative sensor is composed of carbon dots (CDs) derived from black grapes (BG) and eosin Y (EY) dye. The interaction between the studied drugs and EY/BG@CDs sensor components allows for their simultaneous detection where GNT quenches the fluorescence of EY at 535 nm without affecting the fluorescence of CDs, while KET quenches the fluorescence of BG@CDs at 385 nm without impacting EY fluorescence. The BG@CDs probe was successfully characterized using various techniques such as absorption spectrophotometry, spectrofluorimetry, TEM imaging, infrared spectroscopic analysis, and XRD analysis. The suggested methodology was observed to be highly sensitive for the simultaneous determination of GNT and KET in their spiked rabbit plasma samples, with wide linear ranges and low limit of detection (LOD) values. The studied drugs were extracted using a highly selective extraction method involving protein precipitation followed by mixed mode solid phase extraction using an Oasis WCX cartridge. The simultaneous determination of GNT and KET is essential due to the potential interactions between the studied drugs. Therefore, this analysis can be used to evaluate the necessity of dose monitoring and the potential adverse effects of co-administration of these drugs.

Protective role of Dodonaea viscosa extract against streptozotocin-induced hepatotoxicity and nephrotoxicity in rats

Previous investigations have shown that D. viscosa herbal extract is often used to treat a variety of diseases. Therefore, the purpose of this study was to investigate any additional potential impacts on rat liver and kidney damage induced by diabetes. Streptozotocin (STZ) (60 mg/kg/day) was given as a single dosage to cause type 1 diabetes. After then, diabetic rats received oral doses of D. viscosa for four weeks at 150 and 300 mg/kg/day. Blood, liver, and kidney tissues were collected at the end of the treatment and examined. Analysis was made of the serum lipid profile, liver, and kidney functions, as well as blood biochemistry. Moreover, the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), prostaglandin E-2 (PGE-2), and nitric oxide (NO) were estimated in serum. In liver and kidney samples, thiobarbituric acid reactive substances (TBARs) and reduced glutathione (GSH), as well as the pro-inflammatory cytokines and enzymatic activities of glutathione peroxidase (GPx), glutathione reeducates (GR), glutathione-S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) were analyzed. Histological changes in liver and kidney cross-sections were also observed. Our findings demonstrated that D. viscosa dramatically decreased pro-inflammatory indicators in blood, kidney, and liver tissues as well as blood glucose, and restored insulin levels, and lipid profiles. Additionally, it significantly raises the antioxidant enzyme activity SOD, CAT, GPx, and GST, while significantly lowering TBARs levels. The above-mentioned biochemical changes that took place in tissues were further supported by histological alterations. These findings imply that D. viscosa protects against STZ-induced hyperglycemia, aberrant lipid synthesis, and oxidative stress and that these benefits may be mediated by interacting with various targets to increase the levels of antioxidant enzymes in the liver and kidneys. Its mode of action and safety for use as medicine against various metabolic problems caused by diabetes require more research.

The Potential Protective Role of Naringenin against Dasatinib-Induced Hepatotoxicity

Dasatinib (DASA) is a novel tyrosine kinase inhibitor, approved for leukemia treatment. However, the long-term use of DASA induces several complications, especially liver damage. On the other hand, Naringenin (NGN) is a potent antioxidant and anti-inflammatory agent which is known to exert protective effects in several liver disease animal models. Yet, the effect of NGN on DASA-induced hepatotoxicity has not been examined. This study investigated the hepatoprotective effects of NGN against DASA-induced acute liver injury, using a mouse model. The mice were given NGN (50, 100, and 200 mg/kg po) or saline for 7 days, followed by DASA on the eighth day (25 mg/kg p.o.). DASA treatment alone was found to cause overexpression of proinflammatory cytokines, such as interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and malonyl aldehyde (MDA), whereas attenuation of antioxidant genes including superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx). Interestingly, a pretreatment with NGN + DASA resulted in minimizing the proinflammatory mediators and restoring the levels of antioxidant genes. In addition, there was evidence of necro-inflammatory changes in histopathological findings in the liver samples after DASA administration which remarkably reduced with NGN + DASA. Thus, this study revealed that NGN could minimize the hepatotoxicity induced by DASA by providing anti-inflammatory and antioxidant protection.

Targeting Store-Operated Calcium Entry Regulates the Inflammation-Induced Proliferation and Migration of Breast Cancer Cells

Persistent challenges complicating the treatment of breast cancer remain, despite some recent undeniable successes. Sufficient evidence currently exists demonstrating the crucial role of inflammation, characterized by the enhanced activation of Toll-like receptor 4 (TLR4) and the COX-2/PGE2 pathway, in the migration and proliferation of breast cancer cells. Interestingly, the store-operated calcium entry (SOCE) pathway was shown to be essential for the TLR4 activity and COX-2 expression in immune cells such as macrophages and microglia. However, whether SOCE influences inflammatory signaling and the inflammation-induced proliferation and migration of breast cancer cells is still unknown. Thus, the current study intended to delineate the role of SOCE in the TLR4-induced inflammation, migration, and proliferation of breast cancer cells. To this end, MDA-MB-231 breast cancer cells were treated with lipopolysaccharide (LPS) to activate TLR4, BTP2 to inhibit SOCE, and Thapsigargin to induce SOCE. Following these treatments, several experiments were conducted to evaluate the proliferation and migration rates of the MDA-MB-231 cells and the expression of several inflammatory and oncogenic genes, including COX-2, PGE2, IL-6, IL-8, and VEGF. Different techniques were used to achieve the aims of this study, including qRT-PCR, Western blotting, ELISA, MTT, and wound healing assays. This study shows that SOCE inhibition using BTP2 suppressed the LPS-induced migration and proliferation of breast cancer cells. Additionally, treatment with LPS caused approximately six- and three-fold increases in COX-2 mRNA and protein expression, respectively, compared to the controls. The LPS-induced elevations in the COX-2 mRNA and protein levels were suppressed by BTP2 to the control levels. In addition to its effect on COX-2, BTP2 also suppressed the LPS-induced productions of PGE2, IL-6, IL-8, and VEGF. Conversely, SOCE induction using Thapsigargin enhanced the LPS-induced inflammation, migration, and proliferation of breast cancer cells. Collectively, these results provide evidence for the potentially important role of SOCE in inflammation-induced breast cancer progression processes. Thus, we argue that the current study may provide novel targets for designing new therapeutic approaches for the treatment of breast cancer.

A molecularly imprinted electrochemical sensor for specific and ultrasensitive determination of an aminoglycoside drug: the role of copper ions in the determination

Herein, a molecularly imprinted polymer (MIP) was fabricated for specific sensing of an aminoglycoside e.g. kanamycin (KANA). Carbon paste modified with a MIP specific to Cu²⁺-KANA was first introduced. Copper (Cu²⁺) as a metal ion was used as a signal tracer and an amplifier, producing a current response measured by differential pulse voltammetry (DPV). Introducing the aminoglycoside drug into the solution containing Cu²⁺ did not affect the current response of the NIP/CPE. Under the optimum conditions, the as-fabricated sensor exhibited an increase in the current response in the range of 0.55-550 nM with a good limit of detection (LOD, S/N = 3) of 161 pM. The sensor exhibited many advantages including high sensitivity and selectivity, good stability and reproducibility, and cost-effectiveness. Moreover, it was successfully applied for the determination of KANA in milk and honey samples with RSD % not more than 3.3%, suggesting the reliability of the as-designed sensor.

Mitogen-activated protein kinase inhibitor PD98059 improves neuroimmune dysfunction in experimental autoimmune encephalomyelitis in SJL/J mice through the inhibition of nuclear factor-kappa B signaling in B cells

Multiple sclerosis (MS) is a severe autoimmune disease leading to demyelination, followed by consequent axonal degeneration, causing sensory, motor, cognitive, and visual symptoms. Experimental autoimmune encephalomyelitis (EAE) is the most well-studied animal model of MS. Most current MS treatments are not completely effective, and severe side effects remain a great challenge. In this study, we report the therapeutic efficacy of PD98059, a potent mitogen-activated protein kinase inhibitor, on proteolipid protein (PLP)_139-151-induced EAE in SJL/J mice. Following the induction of EAE, mice were intraperitoneally treated with PD98059 (5 mg/kg for 14 days) daily from day 14 to day 28. This study investigated the effects of PD98059 on C-C motif chemokine receptor 6 (CCR6), CD14, NF-κB p65, IκBα, GM-CSF, iNOS, IL-6, TNF-α in CD45R⁺ B lymphocytes using flow cytometry. Furthermore, we analyzed the effect of PD98059 on CCR6, CD14, NF-κB p65, GM-CSF, iNOS, IL-6, and TNF-α mRNA and protein expression levels using qRT-PCR analysis in brain tissues. Mechanistic investigations revealed that PD98059-treated in mice with EAE had reduced CD45R⁺CCR6⁺, CD45R⁺CD14⁺, CD45R⁺NF-κB p65⁺, CD45R⁺GM-CSF⁺, CD45R⁺iNOS⁺, CD45R⁺IL-6⁺, and CD45R⁺TNF-α⁺ cells and increased CD45R⁺IκBα⁺ cells compared with vehicle-treated control mice in the spleen. Moreover, downregulation of CCR6, CD14, NF-κB p65, GM-CSF, iNOS, IL-6, and TNF-α mRNA expression level was observed in PD98059-treated mice with EAE compared with vehicle-treated control mice in the brain tissue. The results of this study demonstrate that PD98059 modulates inflammatory mediators through multiple cellular mechanisms. The results of this study suggest that PD98059 may be pursued as a therapeutic agent for the treatment of MS.

Valsartan prevents gefitinib-induced lung inflammation, oxidative stress, and alteration of plasma metabolites in rats

Gefitinib (GEF) is an inhibitor of the epidermal growth factor receptor, linked to higher risk of severe/fatal interstitial lung disease (ILD). This study was performed to determine the protective roles of an angiotensin-II type-1 receptor (AT1R) "valsartan (VAL)" in prevention of lung inflammation, oxidative stress and metabolites alteration induced by GEF. Four groups of male Wistar albino rats were received vehicle, VAL (30 mg/kg), GEF (30 mg/kg), or both for four weeks. Blood samples and lungs were harvested for plasma metabolites and histological analysis, respectively, and evaluation of inflammation and oxidative stress. GEF monotherapy showed a dense inflammation in lungs, and significantly increased tumor necrosis factor-α (P = 0.0349), interleukin-6 (P < 0.0001), chemokine ligand-3 (P = 0.0420), and interleukin-1β (P = 0.0377). GEF increased oxidative stress markers including glutathione, malondialdehyde, and catalase levels. Also, several plasma metabolites including butanoic acid, N-methylphenylethanolamine, oxalic acid, l-alanine, phosphoric acid, l-theorinine, pyroglutamic acid, and 2-bromosebacic acid were changed by GEF. The combination of VAL plus GEF reduced the inflammation and oxidative stress mediated by GEF monotherapy. In addition, the combination treatment returned plasma metabolites to the normal levels compared to GEF monotherapy. These findings revealed that VAL has a possible pulmonary protective role against pulmonary toxicity of GEF, which may lead to novel approaches for management of GEF-induced ILD.

Blockade of store-operated calcium entry sensitizes breast cancer cells to cisplatin therapy via modulating inflammatory response

Store-operated calcium entry (SOCE) is an important pathway for calcium signaling that regulates calcium influx across the plasma membrane upon the depletion of calcium stores in the endoplasmic reticulum. SOCE participates in regulating a number of physiological processes including cell proliferation and migration while SOCE dysregulation has been linked with pathophysiological conditions such as inflammation and cancer. The crosslink between cancer and inflammation has been well-established where abundant evidence demonstrate that inflammation plays a role in cancer pathophysiology and the response of cancer cells to chemotherapeutic agents including cisplatin. Indeed, the efficacy of cisplatin against cancer cells is reduced by inflammation. Interestingly, it was shown that SOCE enhances inflammatory signaling in immune cells. Therefore, the main objectives of this study are to examine the impact of SOCE inhibition on the cisplatin sensitivity of breast cancer cells and to explore its related mechanism in modulating the inflammatory response in breast cancer cells. Our findings showed that SOCE inhibitor (BTP2) enhanced cisplatin cytotoxicity against resistant breast cancer cells via inhibition of cell proliferation and migration as well as induction of apoptosis. We also found an upregulation in the gene expression of two major components of SOCE, STIM1 and ORAI1, in cisplatin-resistant breast cancer cells compared to cisplatin-sensitive breast cancer cells. In addition, cisplatin treatment increased the gene expression of STIM1 and ORAI1 in cisplatin-resistant breast cancer cells. Finally, this study also demonstrated that cisplatin therapy caused an increase in the gene expression of inflammatory mediators COX2, IL-8, and TNF-α as well as COX2 protein and upon SOCE inhibition using BTP2, the effect of cisplatin on the inflammatory mediators was reversed. Altogether, this study has proven the pivotal role of SOCE in cisplatin resistance of breast cancer cells and showed the importance of targeting this pathway in improving breast cancer therapy.

Hydroxychloroquine ameliorates dasatinib-induced liver injury via decrease in hepatic lymphocytes infiltration

Dasatinib is an effective treatment for chronic myeloid leukemia. However, cases of idiosyncratic hepatotoxicity were reported. This study was conducted to investigate the chemopreventive effects of hydroxychloroquine against dasatinib-induced hepatotoxicity. Balb/c mice were randomly assigned into four groups; vehicle control (5% DMSO, i.p., n = 6), dasatinib (50 mg/kg; i.p., n = 6), hydroxychloroquine (10 mg/kg, i.p., n = 6), and hydroxychloroquine + dasatinib (10 mg/kg + 50 mg/kg; i.p., n = 6). Treatments were given once every 2 days for 14 days. Serum and histopathological assessments of liver architecture and fibrosis were performed using H&E, Masson's trichrome, and reticulin staining. The infiltration of lymphocytes was assessed using immunohistochemistry. The gene expression of antioxidant enzymes (CAT, SOD-2, GPX-1) was assessed using real-time quantitative PCR. Dasatinib showed a significant increase in liver injury biomarkers (AST and ALT) with higher lymphocytes infiltration (as indicated by CD3⁺, CD4⁺, CD8⁺, and CD20⁺ immunohistochemistry). Hepatic tissue of Dasatinib group exhibited significant downregulation in the gene expression of antioxidant enzymes (CAT, SOD-2, and GPX-1) compared to the control group. However, the combination of hydroxychloroquine with dasatinib showed a slight increase in AST and ALT. Also, hydroxychloroquine + dasatinib treated mice showed a significant reduction in lymphocytes infiltration as compared to dasatinib. The results showed that dasatinib induces an immune response leading to an increase in lymphocytes infiltration which promotes hepatocyte destruction and persistent liver injury. The results also suggest that hydroxychloroquine ameliorates dasatinib-induced hepatotoxicity via reduction in hepatic infiltration of T and B immune cells.

In vitro and In vivo Studies of Potential Anticancer Agents of Platinum(II) Complexes of Dicyclopentadiene and Dithiocarbamates

Three platinum(II) complexes of dicyclopentadiene (DCP) and dithiocarbamates (DTC), namely, [Pt(η4-DCP)(Me2DTC)]PF6 (1), [Pt(η4-DCP)(Et2DTC)]PF6 (2) and [Pt(η4-DCP)(Bz2DTC)]PF6 (3) [Me2DTC = dimethyldithiocarbamate, Et2DTC = diethyldithiocarbamate, and Bz2DTC = dibenzyldithiocarbamate] were prepared and characterized by elemental analysis, IR, 1H and 13C NMR spectroscopy. The spectroscopic data indicated the coordination of both DCP and dithiocarbamate ligands to platinum(II). The solution chemisty of complex 1 revealed that the complexes are stable in both DMSO and 1:1 mixture of DMSO: H2O. In vitro cytotoxicity of the complexes relative to cisplatin was tested using MTT assay, against CHL-1 (human melanoma cancer cells), MDA-MB-231 (breast cancer cells), A549 (lung cancer cells), and B16 (murine melanoma cancer cells). The antiproliferative effect of all three prepared complexes was found to be significantly higher than cisplatin. Furthermore, flow cytometric analysis of complex 1 showed that the complex induced apoptosis, oxidative stress, mitochondrial potential depolarization and cell cycle arrest in a concentration-dependent pattern in the CHL-1 cells. Confirmation of apoptosis via gene expression analysis demonstrated down-regulation of anti-apoptotic genes and up-regulation of pro-apoptotic genes in the CHL-1 cells. Wound healing assays also lent support to the strong cytotoxicity of the complexes. In vivo studies showed a significant reduction of tumor volume at the end of the experiment. In addition, the drug did not change the weight of the mice. In conclusion, complex 1 inhibited cell proliferation in vitro and reduced tumor growth in vivo.

Evaluation of antitumor effects of VEGFR-2 inhibitor F16 in a colorectal xenograft model

OBJECTIVES

Colorectal cancer (CRC) is the third most prevalent type of cancer in the United States. The treatment options for cancer include surgery, chemotherapy, radiation, and/or targeted therapy, which show significant improvement in overall survival. Among the various available treatments, antagonizing VEGF/VEGFR-2 pathways have shown effectiveness in limiting colorectal cancer growth and improving clinical outcomes. In this regard, we hypothesized that F16, a novel VEGFR-2 inhibitor, would control colorectal cancer growth by blocking the VEGFR-2 singling pathway in both in vitro and in vivo conditions. Therefore, the current study was aimed to analyze the efficacy of F16 on the growth of Colo 320DM cells under in vitro and in vivo conditions.

RESULTS

Human RT² profiler PCR array analysis results clearly showed that angiogenesis and anti-apoptosis-related gene expressions were significantly reduced in HUVEC cells after F16 (5 μM) treatment. In addition, Western blot results revealed that F16 attenuated the downstream signaling of the VEGFR-2 pathway in HUVEC cells by up-regulating the p53 and p21 levels and down-regulating the p-AKT and p-FAK levels. Accordingly, F16 confirmed potent cytotoxic effects against the cell viability of Colo 320DM tumors, with an IC₅₀ value of 9.52 ± 1.49 µM. Furthermore, treatment of mice implanted with Colo 320DM xenograft tumors showed a significant reduction in tumor growth and increases in survival rate compared to controls. Immunohistochemistry analysis of tumor tissues showed a reduction in CD31 levels also in F16 treated groups.

CONCLUSIONS

These results justify further evaluation of F16 as a potential new therapeutic agent for treating colorectal cancers.

In vivo and in vitro studies evaluating the chemopreventive effect of metformin on the aryl hydrocarbon receptor-mediated breast carcinogenesis

Metformin (MET) is a clinically used anti-hyperglycemic agent that shows activities against chemically-induced animal models of cancer. A study from our laboratory showed that MET protectes against 7, 12-dimethylbenz[a]anthracene (DMBA)-induced carcinogenesis in vitro human non-cancerous epithelial breast cells (MCF10A) via activation of the aryl hydrocarbon receptor (AhR). However, it is unclear whether MET can prevent the initiation of breast carcinogenesis in an in vivo rat model of AhR-induced breast carcinogenesis. Therefore, the main aims of this study are to examine the effect of MET on protecting against rat breast carcinogenesis induced by DMBA and to explore whether this effect is medicated through the AhR pathway. In this study, treatment of female rats with DMBA initiated breast carcinogenesis though inhibiting apoptosis and tumor suppressor genes while inducing oxidative DNA damage and cell cycle proliferative markers. This effect was associated with activation of AhR and its downstream target genes; cytochrome P4501A1 (CYP1A1) and CYP1B1. Importantly, MET treatment protected against DMBA-induced breast carcinogenesis by restoring DMBA effects on apoptosis, tumor suppressor genes, DNA damage, and cell proliferation. Mechanistically using in vitro human breast cancer MCF-7 cells, MET inhibited breast cancer stem cells spheroids formation and development by DMBA, which was accompanied by a proportional inhibition in CYP1A1 gene expression. In conclusion, the study reports evidence that MET is an effective chemopreventive therapy for breast cancer by inhibiting the activation of CYP1A1/CYP1B1 pathway in vivo rat model.

Sorafenib, rapamycin, and venetoclax attenuate doxorubicin-induced senescence and promote apoptosis in HCT116 cells

Emerging evidence has shown that the therapy-induced senescent growth arrest in cancer cells is of durable nature whereby a subset of cells can reinstate proliferative capacity. Promising new drugs named senolytics selectively target senescent cells and commit them into apoptosis. Accordingly, senolytics have been proposed as adjuvant cancer treatment to cull senescent tumor cells, and thus, screening for agents that exhibit senolytic properties is highly warranted. Our study aimed to investigate three agents, sorafenib, rapamycin, and venetoclax for their senolytic potential in doxorubicin-induced senescence in HCT116 cells. HCT116 cells were treated with one of the three agents, sorafenib (5 µM), rapamycin (100 nM), or venetoclax (10 µM), in the absence or presence of doxorubicin (1 µM). Senescence was evaluated using microscopy-based and flow cytometry-based Senescence-associated-β-galactosidase staining (SA-β-gal), while apoptosis was assessed using annexin V-FITC/PI, and Muse caspase-3/-7 activity assays. We screened for potential genes through which the three drugs exerted senolytic-like action using the Human Cancer Pathway Finder PCR array. The three agents reduced doxorubicin-induced senescent cell subpopulations and significantly enhanced the apoptotic effect of doxorubicin compared with those treated only with doxorubicin. The senescence genes IGFBP5 and BMI1 and the apoptosis genes CASP7 and CASP9 emerged as candidate genes through which the three drugs exhibited senolytic-like properties. These results suggest that the attenuation of doxorubicin-induced senescence might have shifted HCT116 cells to apoptosis by exposure to the tested pharmacological agents. Our work argues for the use of senolytics to reduce senescence-mediated resistance in tumor cells and to enhance chemotherapy efficacy.

Metformin attenuates V-domain Ig suppressor of T-cell activation through the aryl hydrocarbon receptor pathway in Melanoma: In Vivo and In Vitro Studies

Melanoma is an aggressive skin cancer with a high rate of metastasis to other organs. Recent studies specified the overexpression of V-domain Ig suppressor of T-cell activation (VISTA) and Aryl Hydrocarbon Receptor (AHR) in melanoma. Metformin shows anti-tumor activities in several cancer types. However, the mechanism is unclear. This study aims to investigate the inhibitory effect of metformin on VISTA via AHR in melanoma cells (CHL-1, B16) and animal models. VISTA and AHR levels were assessed by qPCR, Western blot, immunofluorescence microscope, flow cytometry, and immunohistochemistry. Here, metformin significantly decreased VISTA and AHR levels in vitro and in vivo. Furthermore, metformin inhibited all AHR-regulated genes. VISTA levels were dramatically inhibited by AHR modulations using shRNA and αNF, confirming the central role of AHR in VISTA. Finally, melanoma cells were xenografted in C57BL/6 and nude mice. Metformin significantly reduced the tumor volume and growth rate. Likewise, VISTA and AHR-regulated protein levels were suppressed in both models. These findings demonstrate for the first time that VISTA is suppressed by metformin and identified a new regulatory mechanism through AHR. The data suggest that metformin could be a new potential therapeutic strategy to treat melanoma patients combined with targeted immune checkpoint inhibitors.

Protective effect of valsartan against doxorubicin-induced cardiotoxicity: Histopathology and metabolomics in vivo study

Doxorubicin (DOX) treatment has been associated with cardiotoxicity. Therefore, it is crucial to search for a therapeutic that can effectively mitigate DOX-induced cardiotoxicity. This study was conducted to investigate the protective effects of valsartan (VAL) against DOX-induced cardiotoxicity. Sprague-Dawley rats were divided into four treatment groups: Group I: Control, Group II: VAL (30 mg/kg, ip), Group III: DOX (15 mg/kg, ip), and Group IV: VAL + DOX (30 + 15 mg/kg, ip). All groups were treated every other day for 14 days. Blood was isolated for biochemical and metabolomics studies, and sections of the heart were also analyzed for histopathological and immunohistochemical alterations to detect changes in P53, BAX, BCL-2, and P62 expression. The combination of VAL + DOX resulted in a marked decrease in cardiac biomarker enzymes (aminotransferase and creatine phosphokinase) compared to DOX monotherapy. In addition, the histopathological examination of the VAL + DOX combination revealed a low percentage of fibrosis and inflammation. Immunohistochemical expression of p53 and BAX was significantly reduced, whereas BCL-2 expression was significantly increased in the VAL + DOX treatment group compared to DOX monotherapy. Also, the combination of VAL + DOX reverses the negative effect of DOX on nuclear p62 expression. Analysis of serum metabolites showed that DOX monotherapy reduced the number of several amino acids, whereas the combination of VAL + DOX restored these metabolic pathways. This study revealed the potential cardioprotective effect of VAL, which may provide novel and promising approaches for managing cardiotoxicity induced by DOX.

Exposure to the plasticizer, Di-(2-ethylhexyl) phthalate during juvenile period exacerbates autism-like behavior in adult BTBR T + tf/J mice due to DNA hypomethylation and enhanced inflammation in brain and systemic immune cells

Epigenetic modifications are known to play a crucial role in the behavioral modifications through regulation of gene expression. Environmental factors are known to regulate genetic transcription through DNA methylation which is one of the mechanisms of epigenetic modification. Di-2-ethylhexyl phthalate (DEHP) is one of the most abundant phthalate plasticizers in day-to-day products. Prenatal/postnatal DEHP administration has been reported to cause inflammation as well as behavioral dysregulation, however it is not known if exposure to DEHP during juvenile stage affects peripheral/neuronal inflammation and autism-like symptoms in BTBR mice at adulthood. This study investigated effect of DEHP exposure during juvenile period on DNA methylation (global DNA methylation/DNMT1 expression) and inflammation (IL-17A, IL-6, MCP-1, TNF-α) in CD4 + T cells/CD11c + DCs and cortex, and autism-like symptoms (three-chambered sociability test, self-grooming and marble burying test) in asocial BTBR and social C57 mice at adulthood. Our data reveal that BTBR mice exposed to DEHP during juvenile period have hypomethylated DNA/DNMT1 expression in CD11c + DCs and cortex as compared to vehicle-exposed BTBR mice. It was associated with upregulated inflammation in periphery [plasma IL-6/IL-17A, CD11c + DCs (IL-6/MCP-1/TNF-α), and CD4+ T cells (IL-17A)] and cortex (IL-6, MCP-1, TNF-α), and aggravation in autism-like symptoms in DEHP-treated BTBR mice. These data propose that exposure of DEHP during juvenile period may affect autism-like behavior and inflammation in BTBR mice at adulthood through epigenetic regulation. Therefore, underlying genetic predisposition may play a crucial role in worsening of autistic symptoms in ASD subjects in adulthood if they are exposed to environmental pollutants such as DEHP during juvenile period.

Abstract 2024: Studying the effects of interfering with doxorubicin-induced senescence in human colon cancer HCT116 cells

Colorectal cancer (CRC) is type of cancer that growing in the colon or the rectum. Although CRC can be treated and managed through several means of therapy, the disease mortality is still high in Saudi Arabia. Upon treatment, cancer cells undergo different form of cell death or growth arrest such as apoptosis and senescence. Senescence is a state of proliferation arrest that is considered as a cause of drug resistance. The current study was designed to interfere with Doxorubicin-induced senescence in cancer cells, and shift the cytotoxicity of doxorubicin from proliferation arrest to apoptosis. β-galactosidase (β-gal) staining has demonstrated that Doxorubicin induces senescence in wild-type HCT116 but not in p21 knock-out cells. (DAPI)/TUNEL stating and Annexin V assay indicate that treatment with Doxorubicin promotes apoptosis in p21 knock-out HCT116 significantly more than in wild-type HCT116. β-galactosidase staining and 5-Dodecanoylaminofluorescein Di-β-D-Galactopyranosid (C12FDG) demonstrated that combination of Doxorubicin with Sorafenib, Rapamycin, or Venetoclax has significantly reduced senescence and induced more apoptosis as shown by Propidium iodide (PI)/Annexin v assay and Caspase 3/7 Assay. PCR data analysis demonstrated that not all combination of Doxorubicin with other agents significantly decreased expression of senescence protein, however, the results of this study provide findings that interference with senescence pathways may shift cytotoxicity from senescence to apoptosis.

The authors extend their appreciation to the Deputyship for Research and Innovation, Ministry of Education in Saudi Arabia for partly funding this work through the project number (DRI-KSU-1273).

Citation Format: Moureq Rashed Alotaibi, Homood As Sobeia, Munirah Alohaydib, Faten Alaqil, Khalid Alhazzani, Ali Alhoshani, Tareq Saleh, David Gewirtz. Studying the effects of interfering with doxorubicin-induced senescence in human colon cancer HCT116 cells [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 2024.

Pharmacological Inhibition of STAT3 by Stattic Ameliorates Clinical Symptoms and Reduces Autoinflammation in Myeloid, Lymphoid, and Neuronal Tissue Compartments in Relapsing-Remitting Model of Experimental Autoimmune Encephalomyelitis in SJL/J Mice

Multiple sclerosis (MS) is an immune-mediated inflammatory disease that leads to demyelination and neuronal loss in the central nervous system. Immune cells of lymphoid and myeloid origin play a significant role in the initiation and amplification of neuronal inflammation in MS. STAT3 signaling plays a pivotal role in both myeloid and lymphoid immune cells, such as neutrophils and CD4+ T cells, through regulation of their inflammatory potential. Dysregulation in STAT3 signaling in myeloid and lymphoid cell compartments has been reported in MS. In this report, we attempted to investigate the effect of a small molecular inhibitor of STAT3, i.e., Stattic, in a relapsing–remitting (RR) model of experimental autoimmune encephalomyelitis (EAE). The effect of Stattic was investigated for clinical features, oxidative stress parameters, and Th17-related signaling in both the periphery and brain of SJL/J mice. Our data report that p-STAT3 expression is elevated in granulocytes, CD4+ T cells, and brain tissue in myelin proteolipid protein (PLP)-immunized SJL/J mice, which is associated with the presence of clinical symptoms and upregulation of inflammatory markers in these cells/tissues. Treatment with Stattic leads to the amelioration of disease symptoms and attenuation of inflammatory markers in neutrophils (iNOS/nitrotyrosine/IL-1β), CD4+ T cells (IL-17A/IL-23R), and brain tissue (IL-17A/iNOS/IL-1β/MPO activity/lipid peroxides) in mice with EAE. These data suggest that the blockade of STAT3 signaling in cells of lymphoid and myeloid origin may cause the attenuation of systemic and neuronal inflammation, which could be responsible for the amelioration of disease symptoms in an RR model of EAE. Therefore, pharmacological inhibition of STAT3 in RRMS could be a potential therapeutic strategy.

Nitrogen doped graphene quantum dots based on host guest interaction for selective dual readout of dopamine

Herein, yellow emissive nitrogen doped graphene quantum dots (N@GQDs) were prepared by a novel advanced thermal driven oxidation. The N@GQDs was functionalized with β-cyclodextrin (β-CD) to improve its catalytic performance towards dopamine (DA) detection. The β-CD/N@GQDs exhibited strong fluorescence at λ_em. = 550 nm after excitation at 460 nm with a quantum yield of 38.6%. The β-CD/N@GQDs showed good peroxidase like activity via catalyzing the oxidation of tetramethylbenzidine (TMB) in presence of H₂O₂ to form blue colored product at λ_max = 652 nm. In the colorimetric assay of DA, the detection based on the oxidation of TMB by H₂O₂ in presence of β-CD/N@GQDs as a catalyst. Then, the color of the blue oxidized TMB (oxTMB) product was reduced by addition of DA. While the fluorometric detection of DA based on the "inner filter effect" of the overlapped emission spectrum of β-CD/N@GQDs with the absorption spectrum of oxTMB, where, addition of DA reduces oxTMB to TMB and restores the fluorescence intensity of β-CD/N@GQDs. Under the optimized conditions, the colorimetric method achieved linearity range of 0.12-7.5 µM and LOD (S/N = 3) of 0.04 µM, while the fluorometric method achieved linearity range of 0.028-1.5 µM and LOD (S/N = 3) of 0.009 µM. The peroxidase like activity of β-CD/N@GQDs was used to detect DA in human plasma and serum samples with good % recoveries. The colorimetric and fluorometric methods exhibited good sensitivity and selectivity toward DA detection.

Ultrasensitive and selective molecularly imprinted electrochemical oxaliplatin sensor based on a novel nitrogen-doped carbon nanotubes/Ag@cu MOF as a signal enhancer and reporter nanohybrid

A sensitive and selective molecular imprinted polymeric network (MIP) electrochemical sensor is proposed for the determination of anti-cancer drug oxaliplatin (OXAL). The polymeric network [poly(pyrrole)] was electrodeposited on a glassy carbon electrode (GCE) modified with silver nanoparticles (Ag) functionalized Cu-metal organic framework (Cu-BDC) and nitrogen-doped carbon nanotubes (N-CNTs). The MIP-Ag@Cu-BDC /N-CNTs/GCE showed an observable reduction peak at -0.14 V, which corresponds to the Cu-BDC reduction. This peak increased and decreased by eluting and rebinding of OXAL, respectively. The binding constant between OXAL and Cu-BDC was calculated to be 3.5 ± 0.1 × 10⁷ mol^-1 L. The electrochemical signal (∆i) increased with increasing OXAL concentration in the range 0.056-200 ng mL^-1 with a limit of detection (LOD, S/N = 3) of 0.016 ng mL^-1. The combination of N-CNTs and Ag@Cu-BDC improves both the conductivity and the anchoring sites for binding the polymer film on the surface of the electrode. The MIP-based electrochemical sensor offered outstanding sensitivity, selectivity, reproducibility, and stability. The MIP-Ag@Cu-BDC /N-CNTs/GCE was applied to determine OXAL in pharmaceutical injections, human plasma, and urine samples with good recoveries (97.5-105%) and acceptable relative standard deviations (RSDs = 1.8-3.2%). Factors affecting fabrication of MIP and OXAL determination were optimized using standard orthogonal design using L₂₅ (5⁶) matrix. This MIP based electrochemical sensor opens a new venue for the fabrication of other similar  sensors and biosensors.

Serum proteomic profiling of patients with amphetamine use disorder

BACKGROUND

Amphetamine use disorder has been recently classified as an epidemic condition. Amphetamine use/abuse has been associated with several neurological and inflammatory effects. However, the exact mechanism involved in these effects warrants further investigation. The aim of this study was to determine any alterations in the serum proteome of individuals classified as patients with amphetamine use disorder compared to that of control subjects.

METHODS

An untargeted proteomic approach employing two-dimensional difference in gel electrophoresis coupled with mass spectrometry was used to identify the patterns of differentially expressed proteins. Serum samples were collected from 20 individuals (males) including 10 subjects with amphetamine use disorder and 10 healthy controls for the present study.

RESULTS

The analysis revealed 78 proteins with a significant difference in protein abundance between the amphetamine-addicted subjects and controls. Among them, 71 proteins were upregulated while 7 proteins remained downregulated in the amphetamine-addicted group. These proteins were further analyzed by ingenuity pathway analysis (IPA) to investigate their correlation with other biomarkers. IPA revealed the correlation of altered proteins with mitogen-activated protein kinase (MAP2K1/K2), p38MAPK, protein kinase-B (PKB; Akt), extracellular signal-regulated kinase (ERK1/2), and nuclear factor-κB signaling pathways. Importantly, these pathways are highly involved in neurological diseases, inflammatory responses, and cellular compromise.

CONCLUSIONS

Our data suggest that the changes in the levels of serum proteins between amphetamine and control groups might affect cellular compromise, inflammatory response, and neurological diseases.

Focal Adhesion Kinase in Ovarian Cancer: A Potential Therapeutic Target for Platinum and Taxane-Resistant Tumors

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase, which is an essential player in regulating cell migration, invasion, adhesion, proliferation, and survival. Its overexpression and activation have been identified in sixty-eight percent of epithelial ovarian cancer patients and this is significantly associated with higher tumor stage, metastasis, and shorter overall survival of these patients. Most recently, a new role has emerged for FAK in promoting resistance to taxane and platinum-based therapy in ovarian and other cancers. The development of resistance is a complex network of molecular processes that make the identification of a targetable biomarker in platinum and taxane-resistant ovarian cancer a major challenge. FAK overexpression upregulates ALDH and XIAP activity in platinum-resistant and increases CD44, YB1, and MDR-1 activity in taxaneresistant tumors. FAK is therefore now emerging as a prognostically significant candidate in this regard, with mounting evidence from recent successes in preclinical and clinical trials using small molecule FAK inhibitors. This review will summarize the significance and function of FAK in ovarian cancer, and its emerging role in chemotherapeutic resistance. We will discuss the current status of FAK inhibitors in ovarian cancers, their therapeutic competencies and limitations, and further propose that the combination of FAK inhibitors with platinum and taxane-based therapies could be an efficacious approach in chemotherapeutic resistant disease.

A newly synthesized platinum-based compound (PBC-II) increases chemosensitivity of HeLa ovarian cancer cells via inhibition of autophagy

There are many mechanisms of resistance, chemoresistance of HeLa cells to anti-cancer agents seems to be autophagy-mediated. While using very effective anti-cancers such as Doxorubicin and cisplatin, cells overcome the cytotoxicity of these drugs through promotion of what so-called cytoprotective autophagy. Here in this study, we sought to introduce a novel platinum-based compound PBC-II that possesses anti-cancer activity. Our data showed that PBC-II is able to induce apoptosis at relatively low concentrations, with no detectable reactive oxygen species (ROS). However, further experiments demonstrated that exposure of HeLa cells to PBC-II did not promote autophagy; rather, it resulted in accumulation of p62 and decrease in LC3-II levels. Autophagy was then promoted in HeLa cells pharmacologically by Doxorubicin and genetically by siRNA IL-10. In order to confirm promotion of autophagy in our model, we performed acridine orange staining to assess for autophagy under microscope as well as via flow cytometry. We then measured protein level of autophagy markers p62 and LC3 by western blot. Our data indicated that PBC-II interferes with therapy-induced autophagy. We also determined PI3K activity while co-incubation of PBC-II with autophagy inducers. It was clear that PI3K activation decreased when PBC-II was co-administered with autophagy inducers. Collectively, PBC-II exerts unique anti-proliferative effects associated with inhibition of autophagy, which indicates that PBC-II is potentially a promising agent to be used in resistant ovarian tumors.

Regulation of cell cycle by MDM2 in prostate cancer cells through Aurora Kinase-B and p21WAF1/CIP1 mediated pathways

Overexpression of MDM2 oncoprotein has been detected in a large number of diverse human malignancies and has been shown to play both p53-dependent and p53-independent roles in oncogenesis. Our study was designed to explore the impact of MDM2 overexpression on the levels of various cell cycle regulatory proteins including Aurora kinase-B (AURK-B), CDC25C and CDK1, which are known to promote tumor progression and increase metastatic potential. Our data from human cell cycle RT² profiler PCR array experiments revealed significant changes in the expression profile of genes that are involved in different phases of cell cycle regulation in LNCaP-MST (MDM2 transfected) prostate cancer cells. Our current study has demonstrated a significant increase in the expression level of AURK-B, CDC25C, Cyclin A2, Cyclin B and CDK1 in LNCaP-MST cells as compared with wild type LNCaP cells that were modulated by MDM2 specific inhibitor Nutlin-3. In fact, the expression levels of the above- mentioned proteins were significantly altered at both mRNA and protein levels after treating the cells with 20 μM Nutlin-3 for 24h. Additionally, the pro-apoptotic proteins including p53, p21, and Bax were elevated with the concomitant decrease in the key anti-apoptotic proteins following MDM2 inhibitor treatment. Also, Nutlin-3 treated cells demonstrated caspase-3 activation was observed with an in-vitro caspase-3 fluorescent assay performed with caspase 3/7 specific DEVD-amc substrate. Our results offer significant evidence towards the effectiveness of MDM2 inhibition in causing cell cycle arrest via blocking the transmission of signals through AURKB-CDK1 axis and inducing apoptosis in LNCaP-MST cancer cells. It is evident from our data that MDM2 overexpression probably is the primary cause for CDK1 up-regulation in the LNCaP-MST cells, which might have occurred possibly through activation of AURK-B. However, further studies in this direction should shed more light on the intracellular mechanisms involved in the regulation of Aurora kinase-B and CDK1 axis in MDM2 positive cancers.

Abstract 185: Direct cytotoxic effect of a novel anti-angiogenic drug F16 towards U87MG glioblastoma cell line

Glioblastoma multiforme (GBM) is one of the most aggressive and lethal types of brain cancers with low 5-year survival rate. Therefore, search for better drugs and effective treatment strategies for GBM to improve patient outcomes is continuing. Since GBM is one of the most highly vascularized solid tumors and its growth is angiogenesis-dependent, antagonizing tumor angiogenesis by using angiogenesis inhibitors seems to be one of the promising approaches. In this context, intensive pre-clinical evaluation of our patented anti-angiogenic compound, code-named F16, has exhibited potent anti-angiogenic and anti-tumor activities via selectively antagonizing VEGFR-2 in both in vitro and in vivo models. More importantly, assessment of biochemical parameters that are reflecting the safety of F16 in the in vivo system showed no alterations in the toxicological parameters of heart, liver, kidney, and pancreas, after 30 days of treatment, at the dose of 100 mg/kg body weight. Hence, we tested the direct effects of F16 for inhibiting the growth, angiogenesis and the migratory abilities of the U87MG glioblastoma cells, which are known to express high levels of VEGFR. Our in vitro studies have confirmed potent inhibitory effects of F16 towards the migration and invasion of U87MG cells, and also revealed potent cytotoxic effects (IC50 26 µM) against U87MG cells in comparison to Temozolomide (IC50 430 µM) treatment. In addition, F16 inhibited the phosphorylation of VEGFR-2 through competitive binding and also induced cell cycle arrest and apoptosis by activating p53 pathway in U87MG cells. Furthermore, our in vivo results with ectopically implanted xenograft model confirm the fact that F16 can significantly inhibit tumor growth in the mice implanted with U87MG glioblastoma cell line. Based on our preliminary results, we are proposing that F16 could be a potential candidate for treating GBM, either in monotherapy or in combination with a cytoreductive drug. (This research was supported by the generous funds provided by the Community Foundation of Broward, Florida and also by the Royal Dames of Cancer Research Inc., Ft. Lauderdale, Florida)

Citation Format: Mohammad Algahtani, Khalid Alhazzani, Thiagarajan Venkatesan, Ali Alaseem, Sivanesan Dhandayuthapani, Appu Rathinavelu. Direct cytotoxic effect of a novel anti-angiogenic drug F16 towards U87MG glioblastoma cell line [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 185.

Apremilast ameliorates carfilzomib-induced pulmonary inflammation and vascular injuries

Acute lung injury (ALI) due to chemotherapy occurs frequently. It presents a challenge for clinicians managing therapies for different types of cancers. Carfilzomib (Kyprolis™) is a new proteasome inhibitor that shows promise for the treatment of relapsing multiple myeloma. However, several cases of severe ALI have raised concern about the use of carfilzomib against relapsed multiple myelomas. To improve the efficacy of carfilzomib, a new anti-inflammatory drug for psoriasis treatment, apremilast (Otezla™) was investigated for its protective effects against carfilzomib-induced ALI in rats. RT-PCR analyses revealed that carfilzomib administration in rats markedly increased the levels of tumor necrosis factor-alpha and nuclear factor-kappa B and myeloperoxidase activity with a concomitant increase in lipid peroxidation. The anti-inflammatory cytokine, interleukin-10, was downregulated following carfilzomib administration. Reduction in glutathione levels indicated diminished cellular antioxidant defenses in response to carfilzomib-induced ALI. ALI was confirmed by histopathological observations in lung tissue slices. Apremilast administration reduced lung inflammation in terms of reduction in myeloperoxidase activity and levels of tumor necrosis factor-alpha and alveolar infiltrating cells. Apremilast reversed all observed toxic effects of carfilzomib and prevented ALI in rats.

Neuroinflammatory Cytokines Induce Amyloid Beta Neurotoxicity through Modulating Amyloid Precursor Protein Levels/Metabolism

Neuroinflammation has been observed in association with neurodegenerative diseases including Alzheimer's disease (AD). In particular, a positive correlation has been documented between neuroinflammatory cytokine release and the progression of the AD, which suggests these cytokines are involved in AD pathophysiology. A histological hallmark of the AD is the presence of beta-amyloid (Aβ) plaques and tau neurofibrillary tangles. Beta-amyloid is generated by the sequential cleavage of beta (β) and gamma (γ) sites in the amyloid precursor protein (APP) by β- and γ-secretase enzymes and its accumulation can result from either a decreased Aβ clearance or increased metabolism of APP. Previous studies reported that neuroinflammatory cytokines reduce the efflux transport of Aβ, leading to elevated Aβ concentrations in the brain. However, less is known about the effects of neuroinflammatory mediators on APP expression and metabolism. In this article, we review the modulatory role of neuroinflammatory cytokines on APP expression and metabolism, including their effects on β- and γ-secretase enzymes.

MDM2 Overexpression Modulates the Angiogenesis-Related Gene Expression Profile of Prostate Cancer Cells

The Murine Double Minute 2 (MDM2) amplification or overexpression has been found in many tumors with high metastatic and angiogenic ability. Our experiments were designed to explore the impact of MDM2 overexpression, specifically on the levels of angiogenesis-related genes, which can also play a major role in tumor propagation and increase its metastatic potential. In the present study, we have used the human angiogenesis RT² profiler PCR array to compare the gene expression profile between LNCaP and LNCaP-MST (MDM2 transfected) prostate cancer cells, along with LNCaP-MST cells treated with Nutlin-3, an MDM2 specific inhibitor. As a result of the overexpression of MDM2 gene in LNCaP-MST (10.3-fold), Thrombospondin 1 (THBS1), Tumor necrosis factor alpha (TNF-α) and Matrix metallopeptidase 9 (MMP9) were also found to be significantly up-regulated while genes such as Epiregulin (EREG), Tissue inhibitor of metalloproteinases 1 (TIMP1) were down-regulated. Also, we determined the total MMP activity and MMP9 expression in LNCaP, LNCaP-MST and SJSA-1 cells. Our results indicated that MDM2 level is positively correlated with MMP activity and MMP9 secretion. Our findings offer strong supporting evidence that MDM2 can impact growth and metastatic potential of cancer cells through tilting the balance towards pro-angiogenic mechanisms.

Anti-angiogenic and pro-apoptotic effects of a small-molecule JFD-WS in in vitro and breast cancer xenograft mouse models

A small molecule that was developed for blocking vascular endothelial growth factor receptor 2 (VEGFR2) has been tested and confirmed for its anti-angiogenic activity. Subsequently, it was modified into a water soluble salt form (JFD-WS) to increase bioavailability and distribution during in vivo pre-clinical testing. The present study was designed to further evaluate the anti-angiogenic and pro-apoptotic effects of JFD-WS in monotherapy as well as in combination with paclitaxel (Taxol) using a mouse xenograft model. The in vitro anti-angiogenic effects of JFD-WS were investigated using cell proliferation, migration, Matrigel tube formation and VEGFR2 phosphorylation assays. The anti-angiogenic effect of JFD-WS was further established using chorioallantoic membrane (CAM) assay followed by in vivo efficacy testing on GI-101A breast adenocarcinoma cells. Pharmacokinetic and toxicity studies were performed using BALB/c mice. Finally, the apoptotic signals were assessed in the control and experimental tumor samples, and the plasma mucin 1 (MUC1) levels were analyzed. In the in vitro tests, JFD-WS effectively inhibited HUVEC proliferation, migration, tube formation and VEGFR2 phosphorylation. Additionally, JFD-WS inhibited the formation of blood vessels in chick chorioallantoic membrane. While inhibiting the xenograft tumor growth in experimental mice, JFD-WS decreased the plasma MUC1 levels. The western blot analysis of apoptotic markers and fragmentation analysis of DNA confirmed the pro-apoptotic effects of JFD-WS. These results indicated that JFD-WS alone or in combination with paclitaxel exerted antitumor and pro-apoptotic effects in the breast cancer xenograft model due to an anti-angiogenic effect. These results strongly support the clinical translation of its use.

Anti-cancer effects of F16: A novel vascular endothelial growth factor receptor-specific inhibitor

Vascular endothelial growth factor receptor-2 is a dynamic target for therapeutic intervention in various types of cancers. This study was aimed to explore the anti-angiogenic activity of a novel vascular endothelial growth factor receptor-specific inhibitor named F16 in both in vitro and in vivo experimental models. This compound effectively reduced cell proliferation, tube formation, and migration of human umbilical vein endothelial cells in a concentration-dependent manner by directly inhibiting vascular endothelial growth factor binding and subsequent vascular endothelial growth factor receptor-2 phosphorylation. The F16 was also able to inhibit the phosphoinositide 3-kinase/protein kinase B-mediated survival and migration pathways in cancer in addition to inhibiting the focal adhesion kinase and mitogen-activated protein kinases-mediated signaling in GI-101A cancer cells. The chorioallantoic membrane assay followed by tumor growth inhibition measurements with GI-101A breast cancer xenograft implanted athymic nude mice confirmed the in vivo tumor reductive effects of F16. It was interesting to observe a decrease in tumor burden after F16 treatment which correlated very well with the decrease in the plasma levels of mucin-1 (MUC-1). Our studies so far have confirmed that F16 is a specific inhibitor of angiogenesis in both in vitro and in vivo models. The F16 also works very efficiently with Taxol in combination by limiting the tumor growth that is better than the monotherapy with any one of the drugs that were tested individually. Thus, F16 offers a promising anti-proliferative and anti-angiogenic effects with better specificity than some of the existing multi-kinase inhibitors.

Matrix Metalloproteinases: A challenging paradigm of cancer management

Matrix metalloproteinases (MMPs) are members of zinc-dependent endopeptidases implicated in a variety of physiological and pathological processes. Over the decades, MMPs have been studied for their role in cancer progression, migration, and metastasis. As a result, accumulated evidence of MMPs incriminating role has made them an attractive therapeutic target. Early generations of broad-spectrum MMP inhibitors exhibited potent inhibitory activities, which subsequently led to clinical trials. Unexpectedly, these trials failed to meet the desired goals, mainly due to the lack of efficacy, poor oral bioavailability, and toxicity. In this review, we discuss the regulatory role of MMPs in cancer progression, current strategies in targeting MMPs for cancer treatment including prodrug design and tumor imaging, and therapeutic value of MMPs as biomarkers in breast, lung, and prostate cancers.

Abstract 2013: Increased MMPs activity in MDM2 overexpressing cancer cell lines

The matrix metalloprotenases (MMPs) are a family of zinc-dependent endopeptidase and have proteolysis activity which found to impact several physiological and pathophysiological conditions including cancer. In cancer, over 20 types of MMPs promote invasion, angiogenesis, metastasis, and proliferation. For instance, MMP-9 is involved in many processes such as wound healing, tissue remodeling and regulation of inflammation. So far, several studies have also shown that MMP-9 is associated with poor clinical outcome. MMP-9 can facilitate angiogenesis and metastasis by releasing cytokines, pro-angiogenic and pro-metastatic factors. Conversely, the tissue inhibitor of metalloproteinases (TIMP-1) is a well-known negative regulator of MMPs which can also modulate other biological functions independent of MMPs regulation. TIMP-1 dysregulation has been shown to impact ECM integrity and potentiate metastatic ability also. Similarly, MDM2 (Murine Double Minute) has been recognized as an important multi-domain protooncogene which is overexpressed in many types of cancer and is associated with poor prognosis in different tumor types including sarcomas and carcinomas. Previously, our group reported that MDM2 overexpression is regulating MMP-9/TIMP-1 axis in LNCaP and LNCaP-MST (MDM2 transfected) prostate cancer cells. In order to further analyze the status of MMP in MDM2 overexpressing cancers the fluorescence activity assay and the zymography assay were used for measuring the activity of MMPs including MMP-9. Immunoblotting analysis were also used to correlate the expression levels of MDM2, MMP-9, and TIMP-1 in MDM2 overexpressing cell lines with and without Nutlin-3 (20 uM) treatment. Our results indicated that MMP activity is elevated by 97.3 % in LNCaP-MST cells compared to LNCaP. This may be possibly due to the near knockdown levels of TIMP-1 that was observed in LNCaP-MST cells. However, the Nutlin 3 treatment was able to decrease the MMP-9 levels and activity only marginally, without elevating TIMP-1 levels. This suggests that, in addition to MDM2, the PTEN loss in LNCaP-MST cells may also play a role in regulating the levels of TIMP-1 and consequently the activity of MMP-9. Furthermore, in order to verify our original speculation, we analyzed the levels of TIMP-1 in SJSA1 and GI-101A cell lines, which are known to overexpress MDM2 and impart aggressive metastatic abilities. Interestingly, the levels of TIMP-1 were found to be elevated in both SJSA1 and GI-101A cell lines compared to LNCaP-MST cells. This finding indicates that TIMP-1 may paly dual role depending on cancer types and the gene expression status in the tumor microenvironment. Further studies are required to fully delineate the interplay between MDM2 and pro-metastatic mechanisms, including the expression of TIMP-1 and MMP-9. (The financial support from the Royal Dames of Cancer Research Inc., Ft. Lauderdale is gratefully acknowledged).

Citation Format: Ali Alaseem, Thiagarajan Venkatesan, Thanigaivelan Kanagasabai, Khalid Alhazzani, Saad Alobid, Priya Dondapati, Appu Rathinavelu. Increased MMPs activity in MDM2 overexpressing cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2013. doi:10.1158/1538-7445.AM2017-2013

Abstract 309: Effect of histone deacetylase (HDAC) inhibitor on gene expression in MDM2 transfected prostate cancer cells

Deacetylation of histone gives a tag for epigenetic repression and plays an important role in transcriptional regulation, cell cycle progression, and developmental events. HDACs catalyse the removal of the acetyl moiety from the lysine residues of proteins including the core nucleosomal histones. Through removal of critical acetyl groups from histones, HDACs can create a chromatin conformation that can prevent the transcription of genes that encode for proteins involved in cell cycle regulation. Thus together with histone acetyltransferases (HATs), HDACs regulate the level of acetylation and alter multitude of cellular functions and their characteristics. Several alterations of HDAC and HAT levels and activities have been found to be enacted by translocation, amplification, overexpression, or mutation of the relevant genes in a variety of cancers. In many cancer cell lines, overexpression or activation of the HDAC enzymes result in histone hypo-acetylation and consequent promotion of pro-cancerous mechanisms. Therefore, HDAC inhibitors represent a potential new class of antitumor agents with cytotoxic activity and the ability to regulate gene expression in tumor cells. In this study we evaluated the effects of Vorinostat (suberoylanilide hydroxamic acid), which is a potent inhibitor of HDAC activity, on cell cycle regulation in MDM2 (mouse double minute 2 homolog) overexpressing cells. MDM2 amplification or overexpression is found in many tumors that eventually lead to the inactivation of the cell cycle control and loss of pro-apoptotic functions through both p53 dependent and independent mechanisms. The PCR array, qRT-PCR, and western blot analysis of MDM2 overexpressing prostate cancer cells (LNCaP-MST), after treating with Nutlin-3 (20 µm) and 17-AAG (10 µm), was able to trigger p21 expression and down-regulation of BIRC5 (Baculoviral IAP Repeat Containing 5). Similarly, when we treated the MDM2 transfected LNCaP-MST cells with vorinostat (7.5 µm for 24 hrs), some of the above mentioned changes, similar to Nutlin-3 treatment, were observed. As a result of HDAC inhibition the mRNA levels of p21, p53 and TIMP-1 were significantly elevated, while the levels of BIRC5 was significantly down-regulated. Thus, treatment of MDM2 overexpressing cell lines with HDAC inhibitor resulted in activation of p21 and consequent decrease in cell proliferation due to resumption of cell cycle arrest. Our results with LNCaP-MST cells offer convincing evidence to suggest that the inhibition of HDAC can control cell proliferative signals in MDM2 overexpressing prostate cancer cells. (The generous support from the Royal Dames of Cancer Research Inc., Ft. Lauderdale, Florida is gratefully acknowledged).

Citation Format: Thiagarajan Venkatesan, Ali Alaseem, Khalid Alhazzani, Thanigaivelan Kanagasabai, Appu Rathinavelu. Effect of histone deacetylase (HDAC) inhibitor on gene expression in MDM2 transfected prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 309. doi:10.1158/1538-7445.AM2017-309