Kinase Profiling Research Articles

Proteomic analysis of the combined effects of cannabigerol and 3-O-ethyl ascorbic acid on kinase-dependent signalling in UVB-irradiated human keratinocytes.

Oxidative stress induced by medium-wavelength ultraviolet radiation (UVB) is one of the most dangerous environmental stressors for the skin. Therefore, various medicinal remedies aim to prevent the harmful effects of UVB or support the recovery of the damaged cells. This study aimed to evaluate the impact of bioactive phytocannabinoid cannabigerol (CBG) together with 3-O-ethyl ascorbic acid (EAA), a stable, lipophilic derivative of the antioxidant vitamin C, on UVB-induced changes of proteome in cultured human keratinocytes 24h after treatment. Surprisingly, proteomic analysis revealed very prominent CBG and EAA effects on kinases. These changes mainly influenced ERK1/2, IKK, MAP3K7, MAPK14, RIPK2, and NLK. Their expression was decreased by CBG and EAA, especially if used together after UVB-irradiation, so the effects of UVB were abolished restoring the profile of kinases to non-irradiated control. Moreover, CBG and EAA also reduced the UVB-induced modifications of proteins by the lipid peroxidation product 4-hydroxynonenal, especially in the case of AKT, Camkk1, cJun, ERK1, IKKα, MAPK11 and PERK. We conclude that, by maintaining proteome stability and kinase-dependent signalling, both CBG and EAA may support the recovery of human keratinocytes exposed to UVB radiation, especially if applied together, while the time-dependence of these effects should be further studied.

Molecular docking, DFT and antiproliferative properties of 4-(3,4-dimethoxyphenyl)-3-(4-methoxyphenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyridine as potent anticancer agent with CDK2 and PIM1 inhibition potency.

Due to the limited effeteness and safety concerns associated with current cancer treatments, there is a pressing need to develop novel therapeutic agents. 4-(3,4-Dimethoxyphenyl)-3-(4-methoxyphenyl)-1-phenyl-1H-pyrazolo[3,4-b]pyridine (3) was synthesized and Initially screened on 59 cancer cell lines showed promising anticancer activity, so, it was chosen for a 5-dose experiment by the NCI/USA. The GI50 values ranged from 1.04 to 8.02 μM on the entire nine panels (57 cell lines), with a GI50 of 2.70 μM for (MG-MID) panel, indicating an encouraging action. To further explore the molecular attributes of compound 3, we optimized its structure using DFT with the B3LYP/6-31 + + G(d,p) basis set. We have considered vibrational analysis, bond lengths and angles, FMOs, and MEP for the structure. Additionally, pharmacokinetic assessments were conducted using various in-silico platforms to evaluate the compound safety. A molecular modeling study created a kinase profile on 44 different kinases. This allowed us to study our compound's binding affinity to these kinases and compare it to the co-crystallized one. Our findings revealed compound 3 exhibited better binding for half of the tested kinases, suggesting its potential as a multi-kinase inhibitor. To further validate our computational results, we tested compound 3 for its inhibitory effects on CDK2 and PIM1. Compound 3 exhibited an IC50 of 0.30 µM for CDK2 inhibition, making it five times less active than Roscovitine, which has an IC50 of 0.06 µM. However, compound 3 demonstrated slightly better inhibition of PIM1 compared to Staurosporine. These findings suggest that compound 3 is a promising anticancer agent with the potential for further development into a highly active compound.

115 (PB103): Investigation of cabozantinib and zanzalintinib differentiation via in vitro kinase profiling and in vivo tissue and tumor distribution

115 (PB103): Investigation of cabozantinib and zanzalintinib differentiation via in vitro kinase profiling and in vivo tissue and tumor distribution

Environmental fluoxetine promotes skin cell proliferation and wound healing

This study investigates the effects of environmentally-relevant concentrations of fluoxetine (FLX, commercial name: Prozac) on wound healing. Pollution of water systems with pharmaceutical and personal care products, including antidepressants such as FLX and other selective serotonin reuptake inhibitors, is a growing environmental concern. Environmentally-relevant FLX concentrations are known to impact physiological functions and behaviour of aquatic animals, however, the effects of exposure on humans are currently unknown. Using a combination of human skin biopsies and a human keratinocyte cell line, we show that exposure to environmental FLX promotes wound closure. We show dose-dependent increases in wound closure with FLX concentrations from 125 ng/l. Using several –omics and pharmaceutical approaches, we demonstrate that the mechanisms underlying enhanced wound closure are increased cell proliferation and serotonin signalling. Transcriptomic analysis revealed 350 differentially expressed genes after exposure. Downregulated genes were enriched in pathways related to mitochondrial function and metabolism, while upregulated genes were associated with cell proliferation and tissue morphogenesis. Kinase profiling showed altered phosphorylation of kinases linked to the MAPK pathway. Consistent with this, phosphoproteomic analyses identified 235 differentially phosphorylated proteins after exposure, with enriched GO terms related to cell cycle, division, and protein biosynthesis. Treatment of skin biopsies and keratinocytes with ketanserin, a serotonin receptor antagonist, reversed the increase in wound closure observed upon exposure. These findings collectively show that exposure to environmental FLX promotes wound healing through modulating serotonin signalling, gene expression and protein phosphorylation, leading to enhanced cell proliferation. Our results justify a transition from the study of behavioural effects of environmental FLX in aquatic animals to the investigation of effects of exposure on wound healing in aquatic and terrestrial animals, including direct impacts on human health.

A novel trifluoromethyl quinoline derivative targeting SGK1 inducing autophagy and apoptosis via regulating mTOR/FOXO3a pathway in glioblastoma

Glioblastoma (GBM) is known for its aggressive nature and poor prognosis, with currently no effective treatment available. Research has shown that introducing fluorinated functional groups into different parts of natural product quinoline significantly affects its anti-tumor activity. Therefore, this study synthesized the trifluoromethyl quinoline derivative FKL296 to investigate its anti-tumor effect on GBM and reveal its mechanism of action. In vitro and in vivo studies have shown that FKL296 effectively inhibitd the growth of GBM and is relatively safe and low toxicity, whice also induced cell apoptosis and autophagy. Additionally, protein kinase profiling and molecular docking analyses have revealed a strong binding affinity between FKL296 and SGK1. Cellular thermal shift assay experiments have confirmed the targeting of SGK1 by FKL296 and its role in enhancing SGK1 stability. Bioinformatics analysis and pathway validation indicated that FKL296 targeted SGK1 and inhibited autophagy in tumor cells through the mTOR/FOXO3a signaling pathway. In summary, FKL296 may become a promising drug for the treatment of GBM.

Advanced Design, Synthesis, and Evaluation of Highly Selective Wee1 Inhibitors: Enhancing Pharmacokinetics and Antitumor Efficacy.

Wee1 is a kinase that regulates cell cycle arrest in response to DNA damage. Wee1 inhibition is a potential strategy to suppress the growth of tumors with defective p53 or DNA repair pathways. However, the development of Wee1 inhibitors faces some challenges. AZD1775, the first-in-class Wee1 inhibitor, has poor kinase selectivity and dose-limiting toxicity. Here, we report the discovery of 12h, a highly selective and potent Wee1 inhibitor with a favorable pharmacokinetic profile. 12h showed strong antiproliferative effects against Lovo cells, a colorectal cancer cell line, both in vitro and in vivo. Moreover, 12h showed a clean kinase profile and effectively induced cell apoptosis. Our results suggest that 12h is a promising drug candidate for further development as a novel anticancer agent.

NUAK2 Inhibitors, KHKI-01128 and KHKI-01215, Exhibit Potent Anticancer Activity Against SW480 Colorectal Cancer Cells.

NUAK family kinase 2 (NUAK2) is a promising target for cancer therapeutics due to its reported role in protein phosphorylation, a critical process in cancer cell survival, proliferation, invasion, and senescence. This study aimed to identify novel inhibitors that disrupt NUAK2 activity. We have already identified two KRICT Hippo kinase inhibitor (KHKI) compounds, such as KHKI-01128 and KHKI-01215. Our aim was to evaluate the impact of KHKI-01128 and KHKI-01215 on NUAK2 activity and elucidate its mechanism in colorectal cancer cells. To evaluate anticancer properties of these inhibitors, four in vitro assays in the SW480 cell line (time-resolved fluorescence resonance energy transfer assay, KINOMEscan kinase profiling, viability, and apoptosis assays) and two pharmacological mechanism analyses (Gene Set Enrichment Analysis and western blotting) were performed. KHKI-01128 and KHKI-01215 exhibited potent inhibitory activity against NUAK2 (half-maximal inhibitory concentration=0.024±0.015 μM and 0.052±0.011 μM, respectively). These inhibitors suppressed cell proliferation, with half-maximal inhibitory concentrations of 1.26±0.17 μM and 3.16±0.30 μM, respectively, and induced apoptosis of SW480 cells. Gene Set Enrichment Analysis revealed negative enrichment scores of -0.84 for KHKI-01128 (false-discovery rate=0.70) and 1.37 for KHKI-01215 (false-discovery rate=0.18), indicating that both effectively suppressed the expression of YES1-associated transcriptional regulator (YAP) target genes. These results suggest that KHKI-01128 and KHKI-01215 are potent NUAK2 inhibitors with promising potential for pharmaceutical applications.

Discovery of Ureido-Substituted 4-Phenylthiazole Derivatives as IGF1R Inhibitors with Potent Antiproliferative Properties.

The existing kinase inhibitors for hepatocellular carcinoma (HCC) have conferred survival benefits but are hampered by adverse effects and drug resistance, necessitating the development of novel agents targeting distinct pathways. To discover potent new anti-HCC compounds, we leveraged scaffold hopping from Sorafenib and introduced morpholine/piperidine moieties to develop ureido-substituted 4-phenylthiazole analogs with optimized physicochemical properties and binding interactions. Notably, compound 27 exhibited potent cytotoxicity against HepG2 cells (IC50 = 0.62 ± 0.34 μM), significantly exceeding Sorafenib (IC50 = 1.62 ± 0.27 μM). Mechanistic investigations revealed that compound 27 potently inhibited HCC cell migration and colony formation, and it induced G2/M arrest and early-stage apoptosis. Kinase profiling revealed IGF1R as a key target, which compound 27 potently inhibited (76.84% at 10 μM). Molecular modeling substantiated compound 27's strong binding to IGF1R via multiple hydrogen bonds. Computational predictions indicate favorable drug-like properties for compound 27. These findings provide a promising drug candidate for the treatment of HCC patients.

Phosphorylation of cell cycle and apoptosis regulatory protein-1 by stress activated protein kinase P38γ is a novel mechanism of apoptosis signaling by genotoxic chemotherapy.

CARP-1, a perinuclear phospho-protein, regulates cell survival and apoptosis signaling induced by genotoxic drugs. However, kinase(s) phosphorylating CARP-1 and down-stream signal transduction events remain unclear. Here we find that CARP-1 Serine (S)626 and Threonine (T)627 substitution to Alanines (AA) inhibits genotoxic drug-induced apoptosis. CARP-1 T627 is followed by a Proline (P), and this TP motif is conserved in vertebrates. Based on these findings, we generated affinity-purified, anti-phospho-CARP-1 T627 rabbit polyclonal antibodies, and utilized them to elucidate chemotherapy-activated, CARP-1-dependent cell growth signaling mechanisms. Our kinase profiling studies revealed that MAPKs/SAPKs phosphorylated CARP-1 T627. We then UV cross-linked protein extracts from Adriamycin-treated HeLa cervical cancer cells with a CARP-1 (614-638) peptide, and conducted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses of the peptide-bound protein complexes. This experiment revealed SAPK p38γ interaction with CARP-1 (614-638) peptide. Our studies further established that SAPK p38γ, but not other MAPKs, phosphorylates CARP-1 T627 in cancer cells treated with genotoxic drugs. Loss of p38γ abrogates CARP-1 T627 phosphorylation, and results in enhanced survival of breast cancer cells by genotoxic drugs. CARP-1 T627 phosphorylation was also noted in breast tumors from patients treated with radiation or endocrine therapies. We conclude that genotoxic drugs activate p38γ-dependent CARP-1 T627 phosphorylation to inhibit cell growth.

Targeting FGFR1 by β,β-dimethylacrylalkannin suppresses the proliferation of colorectal cancer in cellular and xenograft models

BackgroundColorectal cancer (CRC) continues to be a major global health challenge, ranking as a top cause of cancer-related mortality. Alarmingly, the five-year survival rate for CRC patients hovers around a mere 10–30 %. The disruption of fibroblast growth factor receptor (FGFRs) signaling pathways is significantly implicated in the onset and advancement of CRC, presenting a promising target for therapeutic intervention in CRC management. Further investigation is essential to comprehensively elucidate FGFR1′s function in CRC and to create potent therapies that specifically target FGFR1. PurposeThis study aims to demonstrate the oncogenic role of FGFR1 in colorectal cancer and to explore the potential of β,β-dimethylacrylalkannin (β,β-DMAA) as a therapeutic option to inhibit FGFR1. MethodsIn this research, we employed a comprehensive suite of techniques including tissue array, kinase profiling, computational docking, knockdown assay to predict and explore the inhibitor of FGFR1. Furthermore, we utilized kinase assay, pull-down, cell proliferation tests, and Patient derived xenograft (PDX) mouse models to further investigate a novel FGFR1 inhibitor and its impact on the growth of CRC. ResultsIn our research, we discovered that FGFR1 protein is markedly upregulated in colorectal cancer tissues, suggesting a significant role in regulating cellular proliferation, particularly in patients with colorectal cancer. Furthermore, we conducted a computational docking, kinase profiling analysis, simulation and identified that β,β-DMAA could directly bind with FGFR1 within ATP binding pocket domain. Cell-based assays confirmed that β,β-DMAA effectively inhibited the proliferation of colon cancer cells and also triggered cell cycle arrest, apoptosis, and altered FGFR1-mediated signaling pathways. Moreover, β,β-DMAA effectively attenuated the development of PDX tumors in mice that were FGFR1-positive, with no notable toxicity observed. In summary, our study highlights the pivotal role of FGFR1 in colorectal cancer, suggesting that inhibiting FGFR1 activity could be a promising strategy for therapeutic intervention. We present strong evidence that targeting FGFR1 with β,β-DMAA is a viable approach for the management of colorectal cancer. Given its low toxicity and high efficacy, β,β-DMAA, as an FGFR1 inhibitor, warrants further investigation in clinical settings for the treatment of FGFR1-positive tumors.

Design, Synthesis, Formulation, and Bioevaluation of Trisubstituted Triazines as Highly Selective mTOR Inhibitors for the Treatment of Human Breast Cancer.

The aberrant activation of the PI3K/mTOR signaling pathway is implicated in various human cancers. Thus, the development of inhibitors targeting mTOR has attracted considerable attention. In this study, we used a structure-based drug design strategy to discover a highly potent and kinase-selective mTOR inhibitor 24 (PT-88), which demonstrated an mTOR inhibitory IC50 value of 1.2 nM without obvious inhibition against another 195 kinases from the kinase profiling screening. PT-88 displayed selective inhibition against MCF-7 cells (IC50: 0.74 μM) with high biosafety against normal cells, in which autophagy induced by mTOR inhibition was implicated. After successful encapsulation in a lipodisc formulation, PT-88 demonstrated favorable pharmacokinetic and biosafety profiles and exerted a large antitumor effect in an MCF-7 subcutaneous bearing nude mice model. Our study shows the discovery of a highly selective mTOR inhibitor using a structure-based drug discovery strategy and provides a promising antitumor candidate for future study and development.

Abstract LB054: A novel chemical proteomics approach toward the identification of kinase targets to sensitize tumour cells to the standard of care drug paclitaxel

Abstract Introduction: Chemotherapy, through various signaling pathways changes the kinase activation profiles in tumour cells and it has been shown that blockade of specific kinases led to sensitization of tumour cells to chemotherapeutic drugs. We surmised that, following chemotherapeutic drug treatment, determination of the kinase binding profile of a specific inhibitor using its corresponding chemoprobe may lead to the identification of kinases to be targeted for potentiating the action of the chemotherapeutic drug. The approach we chose to study was to design a chemoprobe carrying a kinase inhibitor warhead to capture and read the kinase binding profiles before and after the chemotherapeutic drug treatment. Our proof-of-concept was made with AB19, a chemoprobe designed with the scaffold of crizotinib, a MET receptor tyrosine kinase inhibitor. The ability of AB19 to bind to MET was validated using KATO-II gastric cancer cells in which MET is amplified. Material and Methods: Gastric cancer cell line KATO-II, prostate cancer cells DU145, PC3 and 22RV1 and normal prostate cells RWPE-1 were used to determine IC50 values for the different drugs alone and in combination with paclitaxel. Cells were lysed 2 h and 24 h after drug treatment. The chemoprobes (control probe or AB19) were subsequently added and kinases captured using magnetic pull down. Proteomics analyses were performed by mass spectrometry. Results: The results showed that AB19 pulled down MET (its primary target) and many other kinases, including LCK, Src, EPHA2, and FAK1 that play an important role in cancer progression. Importantly, the kinase pull-down profiles by the chemoprobe were similar to that reported for free crizotinib, thereby validating the ability of the chemoprobe to simulate the binding of the free drug. In vitro studies with AB19 revealed the following: (a) the kinase pull-down profiles varied with cell lines, with the presence or absence of some important kinases and (b) under conditions where the cells were pretreated with paclitaxel, the kinase profiles between treated and non-treated cells were similar. However, disappearance and appearance of key targets were observed. Based upon the detection of an increase in aurora kinase A (AURKA) and mammalian target of rapamycin (mTOR) spectral counts, we designed 2-drug combinations of specific inhibitors of the latter targets with paclitaxel under equieffective and sequential administrations. Of all the combinations studied, Alisertib (AURKA inhibitor) + paclitaxel was the most synergistic. Conclusion: Taken together, the results suggest that AURKA is a unique target for sensitizing cells to paclitaxel and this novel chemical proteomics approach can be developed as a novel strategy to identify kinase inhibitors capable of significantly sensitizing cancer cells to standard of care drugs. Citation Format: Alaa Omar Baryyan, Ana Belen Fraga Timiraos, Kurt Dejgaard, Bertrand J. Jean-Claude. A novel chemical proteomics approach toward the identification of kinase targets to sensitize tumour cells to the standard of care drug paclitaxel [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB054.

Abstract 4617: Fisetin, a multi-kinase inhibitor enhances chemotherapeutic sensitivity in head and neck cancer

Abstract Background: The limitations of chemotherapeutic applications are often imposed by dose-related toxicity and the emergence of therapeutic resistance. Fisetin, a naturally occurring flavonoid, has demonstrated anticancer properties in various cancer types. Despite its proven effectiveness against cancer, the molecular target of fisetin remains unknown. Methods: Our study focused on understanding how fisetin and chemotherapy work together to inhibit the growth and survival of human HNC. We conducted in silico, in vitro and in vivo investigations. We employed target prediction, kinase profiling, transcriptome analysis and tumor xenograft to identify the chemosensitivity efficacy and mechanism of fisetin. Results: In-silico target prediction suggested that fisetin might target multiple kinases. Based on this lead, we have screened fisetin for different kinase inhibition activities and found that it inhibits multiple CDKs including CDK1, 2, 4, 5 and 6 at nanomolar concentration. To test its cellular activity, we have selected the head and neck cancer (HNC) model and found that fisetin treatment strongly inhibited cell proliferation and arrested the HNC cells in G1 phase followed by apoptotic cell death. In tumor xenograft experiment, we found that oral fisetin treatment inhibited the FaDu and SAS tumor growth in the athymic mouse model. Transcriptome analysis on FaDu and SAS cell lines indicated that fisetin treatment significantly modulates pathways associated with cell cycle progression and regulation. These pathways include cellular assembly, DNA replication, cell death, and cell morphology. Pretreatment of HNC cells with fisetin improved the effectiveness of chemotherapy drugs including cisplatin, 5-fluorouracil, and docetaxel. Consistent with this, fisetin pre-treated cells showed elevated levels of cellular and mitochondrial ROS followed by the activation of caspases and apoptosis induction when compared with that in control cells after cisplatin, 5-FU, or docetaxel treatment. Conclusion: These results imply that fisetin has the potential to be utilized as a multi-kinase inhibitor in cancer cells. The study revealed that fisetin has a strong potential for increasing the sensitivity of cancer cells to chemotherapy. Citation Format: Dhanir Tailor, Deepali Mishra, Sanjay V. Malhotra, Rana P. Singh. Fisetin, a multi-kinase inhibitor enhances chemotherapeutic sensitivity in head and neck 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 4617.

Abstract 1661: Preclinical characterization of HMPL-295, a potent and selective ERK 1/2 inhibitor

Abstract Background: Although therapeutic agents targeting alterations in the MAPK pathway have achieved great clinical success, the overall benefit is still suboptimal. Several studies have shown that reactivation of MAPK signaling is the main basis to compromise the efficacy. Thus, co-inhibition of ERK, the terminal master kinase of MAPK pathway, and the upstream targets may effectively shut down the MAPK signaling cascade and induce deeper and more durable anti-tumor activities. Herein, we present the preclinical characterization of HMPL-295, a potent and selective ERK 1/2 inhibitor, discovered and being currently developed in phase I clinical trial (NCT04908046) by HUTCHMED. Methods: The inhibition on ERK 1/2 kinase was determined using Z-LYTE™ kinase assay. The selectivity of HMPL-295 was evaluated against 394 kinases (KinaseProfilerTM) and 86 safety-related proteins (SafetyScreen87TM) by Eurofins. Cellular target inhibition on phosphorylation of RSK (p-RSK) was detected by ELISA. In vitro anti-proliferation activity of HMPL-295 as a single agent was measured by CCK-8 or CellTiter-Glo luminescent assay. Colony formation assay was used to evaluate the combination effect of HMPL-295 with targeted therapy. Multiple tumor models with RAS/RAF/MAPK pathway activation were applied in immune-deficient mice to investigate the anti-tumor activity of HMPL-295 as a single agent or in combination with either chemotherapy or targeted therapy. Results: HMPL-295 strongly inhibited ERK1 and ERK2 kinase activities with equal IC50 at 4 nM. In human colon cancer cell line COLO 205 harboring BRAFV600E mutation, HMPL-295 inhibited p-RSK, a direct substrate of ERK1/2, with an average IC50 of 180 nM from 3 independent experiments. With the inhibition of ERK and its downstream substrates, HMPL-295 treatment induced tumor cells arresting at G0/G1 phase via down-regulation of cyclin D1/p-RB signaling and consequently attenuated cell growth in a panel of MAPK pathway dysregulated tumor cell lines, but barely affected the growth of normal cells. Furthermore, HMPL-295 demonstrated favorable selectivity in the kinase and safety pharmacology profiling, indicating a low off-target risk. For in vivo studies, oral administration of HMPL-295 induced time- and dose-dependent inhibition of p-RSK and resulted in dose-dependent anti-tumor activity in several tumor models harboring KRAS or BRAF mutations. Moreover, HMPL-295 significantly improved the anti-tumor activity of standard-of-care chemotherapy as well as targeted agents in KRAS- or BRAF-mutant tumor models both in vitro and in vivo. Conclusion: HMPL-295 is a potent and selective ERK1/2 inhibitor which demonstrates strong anti-tumor activity in preclinical models, supporting further clinical evaluation. Citation Format: Jia Hu, Jun Ni, Yuanzhi Lv, Wenjun Li, Hui Zhang, Xin Li, Ying Yu, Zeyu Zhong, Jian Wang, Yang Sai, Weiguo Qing, Yongxin Ren, Michael Shi, Weiguo Su. Preclinical characterization of HMPL-295, a potent and selective ERK 1/2 inhibitor [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 1661.

Abstract 2904: Small molecule inhibitor targeting DDR represents a novel therapeutic strategy for the treatment of pancreatic ductal adenocarcinoma (PDAC)

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is ranked as the second leading cause of cancer-related mortality with a 5-year survival rate of merely 12%. The complexity of PDAC lies in its intrinsic resistance to treatment, attributable to the desmoplastic tumor microenvironment, characterized by an abundance of tumor-promoting extracellular matrix (ECM) and stromal cells. We hypothesize that Discoidin Domain Receptors (DDR), members of the receptor tyrosine kinase family known for their affinity to fibrillar collagens within the ECM, play an important role in promoting PDAC growth and progression. While several drugs targeting DDR proteins have been developed, no inhibitors to DDR proteins are specific or approved for PDAC treatment, thus necessitating the development of novel therapeutic interventions. Methods. A comprehensive high-throughput screening approach employing small molecule inhibitors was executed to identify authentic inhibitors targeting DDR. Subsequently, a rigorous evaluation of specificity of these small molecules was conducted through structural activity relationship (SAR) analyses and reference-based assessments. The efficacy of candidate inhibitors was assessed through functional assays, while mechanistic insights were gleaned using a multifaceted approach, including RNA-seq, real-time PCR, western blot analysis, in vivo experimentation, and Phospho-Receptor Tyrosine Kinase (RTK) profiling to discern any unintended off-target effects. Results: Using an unbiased screening approach, we identified 13 inhibitors that specifically target DDR. SAR studies and cellular thermal shift assay validated CIDD-0108633 (8633) as a bona fide DDR2 inhibitor. Functional assays and RNA-seq analyses demonstrated 8633's capacity to inhibit PDAC growth, metastatic potential, and expression of DNA replication, cell-cycle, and DNA damage repair genes. Combination therapy of 8633 with gemcitabine synergistically reduced PDAC cell viability and metastatic potential. Mechanistic studies revealed the role of ABC transporters in mediating gemcitabine resistance. RTK profiling shows moderate kinase selectivity. In vivo studies affirmed its antitumor effects. Conclusions: The results indicate that the selective inhibition of DDR with small molecule inhibitors suppresses PDAC cell growth and progression, implying that DDR inhibitors have the potential to be developed as safe and efficacious therapeutics for the treatment of pancreatic cancers. Citation Format: Trong Phat Do, Jack Prochnau, Prabhakar Pitta Venkata, Sajid Khan, Santosh Timilsina, Deepika Singh, Daisy Medina, Radhika Amaradhi, Daohong Zhou, Matthew Hart, Stanton McHardy, Manjeet Rao. Small molecule inhibitor targeting DDR represents a novel therapeutic strategy for the treatment of pancreatic ductal adenocarcinoma (PDAC) [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 2904.

Abstract 641: SCD1 upregulation due to STK11/KEAP1 loss upregulates SLC7A11 and causes deregulation of fatty acid metabolism leading to ferroptosis evasion

Abstract Introduction: Non-small cell lung cancer (NSCLC) with co-occurring loss-of-function (LOF) mutations in serine/threonine kinase 11 (STK11) and Kelch-like ECH-associated protein1 (KEAP1) (SK) are notably aggressive and unresponsive to chemo and immunotherapy, in current care standards. Novel therapeutic strategies are in demand to improve the outcomes for SK co-mutant NSCLC patients. We reported earlier that SK LOF mutations enhance cell proliferation and tumor growth in xenograft lung cancer models. We also found the ferroptosis evasion genes are enriched, and targeting ferroptosis regulators is a therapeutic opportunity in SK co-mutant NSCLC. Methods: We used CRISPR/Cas9 gene editing to create stable knockouts of STK11 (SKO), KEAP1 (KKO) or both (DKO), non-targeting control (NTC) in two NSCLC lines. We performed an in vitro druggable genome library CRISPR screening in the same NSCLC lines. We performed kinase profiling and RNA-seq in the cell lines to depict the transcriptomic and proteomic landscape, followed by western blotting and qRT-PCR validation. We also performed BODIPY/C11 assay and lipidomics to explore the ferroptosis and metabolic landscape of SK co-mutant NSCLC models. Results: Stearoyl CoA desaturase-1 (SCD1) was the top CRISPR screen hit, a critical modulator of fatty acid metabolism and ferroptosis evasion. SCD1 expression is significantly higher in NSCLC tissue than adjacent normal tissue (p<0.0001), and high SCD1 expression correlates with poorer prognosis in patients with NSCLC (p=0.027). GSEA from the bulk RNA sequencing in SK co-mutant cells pre-and post-SCD1 inhibitor treatment showed SCD1 inhibition leads to upregulation of the glutathione and glutamic acid pathways compared to NTC cells. Moreover, SK co-mutant cells have a significantly higher expression of SLC7A11, enabling cystine uptake and subsequent conversion to cysteine, essential for maintaining redox balance and cell survival. Hence, SK co-mutant cells are more resistant to cysteine depletion than NTC cells. SCD1 inhibition causes a decrease in SLC7A11 expression exclusively in DKO cells. Eventually, SCD1 inhibition leads to global metabolomic changes in SK co-mutant cells, including key pathways involved in lipid and glucose metabolism. Finally, genetic and pharmacological inhibition of SCD1 prevents tumor growth and sensitizes DKO cells to ferroptosis inducers like erastin. Conclusions: Our findings highlight the importance of the SCD1-SLC7A11 axis in regulating ferroptosis in SK co-mutant models. Current data impact our understanding of ferroptosis in NSCLC and its ability to target SCD1 or ferroptosis in cancer treatment. Compounds such as inhibitors of SLC7A11 (Erastin/IKE) are safe to use with acceptable toxicity and established doses. Hence, our study will facilitate the translation of ferroptosis inducers or SCD1 inhibitors in clinical trials. Citation Format: Utsav Sen, Charles Coleman, Dan Hasson, Triparna Sen. SCD1 upregulation due to STK11/KEAP1 loss upregulates SLC7A11 and causes deregulation of fatty acid metabolism leading to ferroptosis evasion [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 641.

Discovery of a Covalent Inhibitor Selectively Targeting the Autophosphorylation Site of c-Src Kinase.

Nonreceptor tyrosine kinase c-Src plays a crucial role in cell signaling and contributes to tumor progression. However, the development of selective c-Src inhibitors turns out to be challenging. In our previous study, we performed posttranslational modification-inspired drug design (PTMI-DD) to provide a plausible way for designing selective kinase inhibitors. In this study, after identifying a unique pocket comprising a less conserved cysteine and an autophosphorylation site in c-Src as well as a promiscuous covalent inhibitor, chemical optimization was performed to obtain (R)-LW-Srci-8 with nearly 75-fold improved potency (IC50 = 35.83 ± 7.21 nM). Crystallographic studies revealed the critical C-F···C═O interactions that may contribute to tight binding. The kinact and Ki values validated the improved binding affinity and decreased warhead reactivity of (R)-LW-Srci-8 for c-Src. Notably, in vitro tyrosine kinase profiling and cellular activity-based protein profiling (ABPP) cooperatively indicated a specific inhibition of c-Src by (R)-LW-Srci-8. Intriguingly, (R)-LW-Srci-8 preferentially binds to inactive c-Src with unphosphorylated Y419 both in vitro and in cells, subsequently disrupting the autophosphorylation. Collectively, our study demonstrated the feasibility of developing selective kinase inhibitors by cotargeting a nucleophilic residue and a posttranslational modification site and providing a chemical probe for c-Src functional studies.

Discovery of Benzoxazepines as a New Class of PIM1 Kinase Inhibitors Through Structure Based Virtual Screening, Biochemical Evaluation and Cytotoxicity Studies

AbstractPIM kinase is a serine/threonine protein kinase implicated in human cancers because it promotes cell proliferation while inhibiting apoptosis and is a crucial target for malignancy. In the present study, we used 700000 commercially available Chembridge small molecules library for structure‐based drug discovery to identify novel potent PIM1 kinase inhibitors. Based on the virtual screening results, ten compounds were chosen and screened enzymatically at 10 μM. Out of ten compounds, only two compounds, 22876894 (61 %) and 58626268 (63 %), inhibited PIM1 kinase. Subsequently, the enzymatic IC50 value for compounds 22876894 and 58626268 was calculated and found to be 0.8 μM and 3.9 μM. Cell viability was evaluated on human malignant cell lines HCT‐116 (colorectal carcinoma), U‐2OS (osteosarcoma), and non‐cancerous hTERT‐RPE‐1. It was found that compound 22876894 possessed significant inhibitory activity against HCT‐116 (IC50=12.1 μM), U‐2OS (IC50=23.2 μM), and hTERT‐RPE‐1 (IC50=12.7 μM) cell lines. The compound 58626268 possessed significant inhibitory activities against HCT‐116 (IC50=28.1 μM), U‐2OS (IC50=23.5 μM), and hTERT‐RPE‐1 (IC50=21 μM) cell lines. Further, the molecular dynamics simulation of identified compounds (22876894 and 58626268) was performed. Based on kinase profiling, cytotoxicity studies, and molecular dynamics simulation results, we claim 5‐{[7‐(1‐benzothien‐3‐yl)‐9‐hydroxy‐2,3‐dihydro‐1,4‐benzoxazepin‐4(5H)‐yl]carbonyl}pyridin‐2(1H)‐one (22876894) and 4‐(2‐aminoisonicotinoyl)‐7‐(1‐benzothien‐3‐yl)‐2,3,4,5‐tetrahydro‐1,4‐benzoxazepin‐9‐ol (58626268) as a selective and potential PIM1 kinase inhibitors.

Identifying Differences in Molecular Characteristics Relevant for Remodeling of Periodontal Ligament Stem Cells from the Upper and Lower Jaw.

Periodontal defects' localization affects wound healing and bone remodeling, with faster healing in the upper jaw compared to the lower jaw. While differences in blood supply, innervation, and odontogenesis contribute, cell-intrinsic variances may exist. Few studies explored cell signaling in periodontal ligament stem cells (PDLSC), overlooking mandible-maxilla disparitiesUsing kinomics technology, we investigated molecular variances in PDLSC. Characterization involved stem cell surface markers, proliferation, and differentiation capacities. Kinase activity was analyzed via multiplex kinase profiling, mapping differential activity in known gene regulatory networks. Upstream kinase analysis identified stronger EphA receptor expression in the mandible, potentially inhibiting osteogenic differentiation. The PI3K-Akt pathway showed higher activity in lower-jaw PDLSC. PDLSC from the upper jaw exhibit superior proliferation and differentiation capabilities. Differential activation of gene regulatory pathways in upper vs. lower-jaw PDLSC suggests implications for regenerative therapies.

Gene expression profile of mitogen-activated kinases and microRNAs controlling their expression in HaCaT cell culture treated with lipopolysaccharide A and cyclosporine A

ABSTRACT Studies indicate that mitogen-activated protein kinases (MAPKs) are activated and overexpressed in psoriatic lesions. The aim of the study was to assess changes in the expression pattern of genes encoding MAPKs and microRNA (miRNA) molecules potentially regulating their expression in human adult low-calcium high-temperature (HaCaT) keratinocytes exposed to bacterial lipopolysaccharide A (LPS) and cyclosporine A (CsA). HaCaT cells were treated with 1 µg/mL LPS for 8 h, followed by treatment with 100 ng/mL cyclosporine A for 2, 8, or 24 h. Untreated cells served as controls. The molecular analysis consists of microarray, quantitative real-time polymerase chain reaction, and enzyme-linked immunosorbent assay analyses. The statistical analysis of the obtained results was performed using Transcriptome Analysis Console and STATISTICA 13.5 PL with the statistical significance threshold of p < 0.05. Changes in the expression profile of six mRNAs: dual-specificity phosphatase 1 (DUSP1), dual-specificity phosphatase 4 (DUSP4), mitogen-activated protein kinase kinase 2 (MAP2K2), mitogen-activated protein kinase kinase 7 (MAP2K7), mitogen-activated protein kinase kinase kinase 2 (MAP3K2) and mitogen-activated protein kinase 9 (MAPK9) in cell culture exposed to LPS or LPS and the drug compared to the control. We observed that under the LPS and cyclosporine treatment, the expression o/ miR-34a, miR-1275, miR-3188, and miR-382 changed significantly (p < 0.05). We demonstrated a potential relationship between DUSP1 and miR-34a; DUSP4 and miR-34a, miR-382, and miR-3188; MAPK9 and miR-1275, MAP2K7 and mir-200-5p; MAP3K2 and mir-200-5p, which may be the subject of further research in the context of psoriasis.