Cell Growth Inhibitory Activity Research Articles

Synthesis of Azahelicenes via Friedel‐Crafts‐Type Ring‐Closing Reaction of Axially Chiral Compounds

AbstractAza[6]helicene and aza[7]helicene were synthesized by Fridel‐Crafts‐type cyclization of axially chiral compounds. From the axially chiral compounds prepared by Fischer indole synthesis, aza[6]helicene and aza[7]helicene were synthesized. Aza[7]helicene was also synthesized from an axially chiral pyrrole compound prepared by Piloty‐Robinson‐type pyrrole synthesis through simultaneous cyclization on both sides of the pyrrole ring. Aza[6]helicene isomerized readily at room temperature, while aza[7]helicene isomerization at room temperature was less likely to proceed. The cell growth inhibitory activity of each enantiomer of N‐Me‐aza[7]helicene in HeLa cells was examined. Differences in the strength of activity between the enantiomers were observed.

Investigations of Antioxidant and Anti-Cancer Activities of 5-Aminopyrazole Derivatives.

To further extend the structure-activity relationships (SARs) of 5-aminopyrazoles (5APs) and identify novel compounds able to interfere with inflammation, oxidative stress, and tumorigenesis, 5APs 1-4 have been designed and prepared. Some chemical modifications have been inserted on cathecol function or in aminopyrazole central core; in detail: (i) smaller, bigger, and more lipophilic substituents were introduced in meta and para positions of catechol portion (5APs 1); (ii) a methyl group was inserted on C3 of the pyrazole scaffold (5APs 2); (iii) a more flexible alkyl chain was inserted on N1 position (5APs 3); (iv) the acylhydrazonic linker was moved from position 4 to position 3 of the pyrazole scaffold (5APs 4). All new derivatives 1-4 have been tested for radical scavenging (DPPH assay), anti-aggregating/antioxidant (in human platelets) and cell growth inhibitory activity (MTT assay) properties. In addition, in silico pharmacokinetics, drug-likeness properties, and toxicity have been calculated. 5APs 1 emerged to be promising anti-proliferative agents, able to suppress the growth of specific cancer cell lines. Furthermore, derivatives 3 remarkably inhibited ROS production in platelets and 5APs 4 showed interesting in vitro radical scavenging properties. Overall, the collected results further confirm the pharmaceutical potentials of this class of compounds and support future studies for the development of novel anti-proliferative and antioxidant agents.

Design, synthesis, and biological evaluation of chalcone acetamide derivatives against triple negative breast cancer

Chalcones are chemical scaffolds found in natural products, particularly in plants, and are considered for structural diversity in medicinal chemistry for drug development. Herein, we designed and synthesised novel acetamide derivatives of chalcone, characterizing them using 1H NMR, 13C NMR, HRMS, and IR spectroscopic methods. These derivatives were then screened against human cancer cells for cytotoxicity using the SRB assay. Among the tested derivatives, 7g, with a pyrrolidine group, exhibited better cell growth inhibition activity against triple-negative breast cancer (TNBC) cells. Further assays, including SRB, colony formation, and fluorescent dye-based microscopic analysis, confirmed that 7g significantly inhibited MDA-MB-231 cell proliferation. Furthermore, 7g promoted apoptosis by upregulating cellular reactive oxygen species (ROS) levels and disrupting mitochondrial membrane potential (MMP). Elevated expression of pro-apoptotic proteins (Bax and caspase-3) and a higher Bax/Bcl-2 ratio with downregulation of anti-apoptotic (Bcl-2) protein levels were observed in TNBC cells. The above results suggest that 7g can promote cellular death through apoptotic mechanisms in TNBC cells.

A promising perspective through potential antimicrobial, anti‐cancer, and antiviral activity against SARS‐CoV‐2 of silver(I) complexes: Synthesis, characterization, density functional theory calculations, and in‐silico molecular docking studies

This study tends to accomplish the sustainable development goal, which calls for all healthy lives. Antibiotic resistance, cancer, and severe acute respiratory syndrome coronavirus all showed high death rates in recent years. Our approach is to make better medications available to fight these feared health issues. In this context, three silver(I) complexes (1–3) based on the antibiotic gemifloxacin (HGMF) were synthesized and thoroughly examined using analytical, spectral, and thermal methods. The density functional theory suggested that complex 1 has a bent coordination environment while 2 and 3 have a distorted trigonal planar geometry. The optimal donor and acceptor centers were determined by the natural‐bond orbital analysis. Interaction of complexes with calf‐thymus DNA has been investigated and their binding constants were ordered as 3 > 2 > 1. The antimicrobial activity against 10 pathogenic microorganisms demonstrated that complex 3 exhibited superior activity compared with standard antibiotics. Testing against mammalian cell lines, liver carcinoma, breast carcinoma, and colon carcinoma revealed that complex 3 showed remarkable cell growth inhibition activity with IC50 values ranging from 3.0 to 9.3 μg/mL. Studies of Molecular docking against SARS‐CoV‐2 main protease Mpro (ID: 6 WTT) proved a powerful type of interaction at the active site. Complex 3 exhibits a potent inhibition effect with a total binding energy of −12.58 kcal/mol compared with the reference ligand inhibitor K36 suggesting its ability to block viral protease. This study presents promising bioactive candidates that have a practical impact on various medicinal fields.

Design, Synthesis and Anticancer Activity of Substituted 1, 3-Thiazolidin-4-One Derivatives

Background: Cancer is the global cause of death worldwide. Anticancer drug development is the need in today’s scenario. Thiazolidine is the nucleus that shows several pharmacological activities like anticancer, anti-inflammatory, antioxidant, antibacterial, antifungal, antidiabetic, antihyperlipidemic, and antiarthritic activity. In the present work molecular docking Glide module (Schrodinger Inc., USA) has been used for ligand docking against the Polo-like kinase-1. The series of substituted 3-Benzothiazol-2-yl-2-phenyl)-thiazolidin-4-ones were synthesized by the microwave-assisted synthesis system (CEM, USA) and characterized by melting point, FT-IR, 1H NMR, 13C NMR, and HR-MS analysis. Results: Molecular docking studies shows good docking score as well as interactions. Among the synthesized compounds, BG2 had the highest docking score of -8.381, followed by BG8 (-8.19) and BG1 (-8.156). All the newly synthesized compounds were examined for their in vitro anticancer activity against breast cancer cell line MCF-7 by Sulforhodamine B (SRB) assay. Conclusion: BG1, BG2, BG3, BG4, BG5, BG8, BG9, BG10, BG11, BG12, and BG13 (GI50: <80 µg/ml) exhibited significant cell growth inhibitory activity. These results indicate that compounds showing in-vitro activity by molecular docking studies and SRB assay could be lead compounds for further development of anticancer agents and suitable candidates for in-vivo anticancer activity.

Study on synthesizing the complex of sorafenib with 2-hydroxypropyl-β-cyclodextrin to enhance the anticancer activity of the drug substance

Abstract This study aims to synthesize inclusion complex derived from sorafenib (Sor) and hydroxypropyl-β-cyclodextrin (HPβCD) (denoted as [Sor-HPβCD]). The complex of Sor with HPβCD has been synthesized in a mixed solvent of H2O-DMSO, with a DMSO volume fraction of 80 %. The results of FTIR, DSC, and UV–Vis analysis have demonstrated the success of complex formation: the intensity of some characteristic peaks for the Sor binding decreased after complex formation, indicating that a part of the guest molecule has entered the cavity of the HPβCD molecule. This is further supported by the DSC analysis results, showing the transformation of the complex’s crystalline form to an amorphous form. The phase solubility diagram study also indicates that the solubility of Sor significantly increases, approximately 7 times higher than pure Sor, after complex formation. The results of the cell growth inhibition activity test in a water environment show that the complex inhibits the growth of Hep-G2 cells with an IC50 value of 62.4 μg/mL, while pure Sor does not exhibit activity as it is practically insoluble in water.

Abstract 5957: Development of a selective, oral ATP-competitive CDK9 inhibitor, BLX-3030, for treatment of pancreatic cancer

Abstract Introduction Transcription regulators, such as cyclin-dependent kinase 9 (CDK9), have been implicated in the super-enhancer driven transcriptional control of oncogenes in multiple cancers including pancreatic cancer. CDK9 has been shown to be employed by cancer cells for the constant production of short-lived oncoproteins such as c-Myc to maintain their survival. Due to its critical role in regulating transcription in cancer cells, CDK9 has emerged as a potential therapeutic target. Here, we report the antitumor activity of a selective, oral ATP-competitive CDK9 inhibitor, BLX-3030, in preclinical models for pancreatic cancer. Experimental Procedures Fragment-based MolecuLern driven AI workflow methods were used to design a series of ATP-competitive CDK9 specific kinase inhibitors. BLX-3030 was selected as one of the most potent leads with an IC50 of 1.1 nM in a cell-free CDK9 kinase assay. A Sulforhodamine B (SRB) assay was used to evaluate the cell growth inhibitory activity of BLX-3030 in a panel of 10 pancreatic ductal adenocarcinoma (PDAC) and 2 pancreatic neuroendocrine tumor (pNET) cell lines. Western blotting was used to determine the effects of BLX-3030 treatment on c-Myc expression in cancer cells. The combination effects between BLX-3030 and standard of care regimen, gemcitabine (GEM) and nab-paclitaxel (NP), was assessed using the SRB assay. Finally, the in vivo antitumor activity of BLX-3030 alone or in combination with GEM and NP was evaluated in a mouse cell line xenograft model for pancreatic cancer. Results BLX-3030 exhibited potent cell growth inhibitory activity in the panel of pancreatic cancer cell lines with IC50 values ranging from 133.5 nM to 508.1 nM. The potency of BLX-3030 in the cell lines appears to correlate with the expression level of c-Myc in the cell lines. BLX-3030 showed similar activities in PDAC and pNET cell lines with mean IC50 values of 244.5 nM and 194.6 nM, respectively. However, treatment with BLX-3030 for 48 hours did not seem to significantly reduce c-Myc expression in PSN-1 PDAC cells. When combined with GEM and NP, BLX-3030 demonstrated mostly additive effects in PSN-1 cells. Preliminary data from the in vivo study show that BLX-3030 improves the antitumor activity of GEM and NP. Conclusion In summary, BLX-3030 potently inhibited the growth of both PDAC and pNET cells in vitro. The growth inhibitory activity of BLX-3030 in PDAC cell lines correlates with their c-Myc expression levels. BLX-3030 showed an additive effect when combined with standard of care drugs (GEM and NP) in PDAC cell lines. Overall, the novel CDK9 inhibitor, BLX-3030, demonstrated potent activity in pancreatic cancer cell line models and presents a promising preclinical lead for pancreatic cancer. (This work was supported in part by Biolexis Therapeutics and the Seena Magowitz Foundation). Citation Format: Yesenia Barrera-Millan, Zhaoliang Li, Hariprasad Vankayalapati, David J. Bearss, Daniel D. Von Hoff, Haiyong Han. Development of a selective, oral ATP-competitive CDK9 inhibitor, BLX-3030, for treatment of pancreatic 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 5957.

Abstract 4657: PHI-501 is a novel potent next-generation pan-RAF/DDRs inhibitor, and overcomes resistance to RAF or MEK inhibitor in melanoma via dual inhibition of RAF and DDR1/2 signaling

Abstract Background: The prevalent mutation of BRAF (~50%) and NRAS (~30%) in malignant melanomas has led to the aggressive development of RAF and MEK inhibitors as anticancer drugs. However, the major hurdle of targeted therapies for melanoma is resistance to RAF or MEK inhibitors, either intrinsic- or acquired- resistance. PHI-501 is an orally bioavailable and highly effective pan-RAF inhibitor. PHI-501 has dual inhibition activity against pan-RAF and discoidin domain receptor (DDR), a collagen-activated receptor tyrosine kinase. In this study, we evaluated the ability of PHI-501 to overcome drug-resistance to RAF or MEK inhibitors in melanoma harboring NRAS or BRAF mutations. Methods: Three drug-resistant cell lines were established by long-term treatment of belvarafenib in SK-MEL-2 (SK-MEL2BR) and each of dabrafenib and trametinib in SK-MEL-3 (SK-MEL3DR and SK-MEL3TR, respectively). RNA-seq of each resistant cell line and in-depth analysis of sequencing data was conducted, including GSEA. The anti-proliferative activity and signaling inhibition of PHI-501 were evaluated by CCK-8 assay and western blots. A long-term clonogenic assay was performed to confirm cell survival upon PHI-501 treatment. In vivo efficacy was evaluated in SK-MEL-3DR cell line xenograft models. Results: PHI-501 demonstrated significant anti-proliferative effects (GI50 < 1 µM, Mean GI50: 0.3 µM) in all 12 melanoma cell lines tested in this study. PHI-501 exerted cell growth inhibitory activities at least 3 to 50 times stronger than other RAF or MEK inhibitors in each of the resistance cell lines. Moreover, PHI-501 doses of less than 100 nM, significantly inhibited the colony formation of drug-resistant cells. Western blot revealed that PHI-501 retained strong inhibition of both ERK and AKT phosphorylation through downregulating pDDRs. In the SK-MER3DR xenograft mouse model, treatment of PHI-501 alone induced a rapid tumor reduction (TGI 72.1%), whereas the vehicle or dabrafenib did not display an anti-melanoma effect (TGI -7.4%). A comprehensive pathway analysis showed the TNFA-NFKB, IL6-JAK-STAT3, and KRAS signaling enriched in drug-resistant cells compared to the parental cells. PHI-501 treatment effectively downregulated those pathways in all three drug-resistant cells. In particular, PHI-501 downregulates the geneset in epithelial-mesenchymal transition (EMT) signaling more effectively in SK-MEL2BR, SK-MEL3DR, and SK-MEL3TR (Adjusted P=<.0001, and NES: -2.01, -1.72, -2.30, respectively). Conclusion: Novel pan-RAF/DDR dual inhibitor PHI-501 has greater anti-tumor activity in RAF or MEK inhibitor-resistant melanoma, which is through downregulation of MAPK signaling and EMT-related genesets and promoting apoptosis. These data support that the clinical development of PHI-501 for melanoma refractory to MAPK inhibitors. Citation Format: Sue Min Kim, Sungmin Cho, Gi-Jun Sung, Ky-Youb Nam, June Han, Sang Joon Shin. PHI-501 is a novel potent next-generation pan-RAF/DDRs inhibitor, and overcomes resistance to RAF or MEK inhibitor in melanoma via dual inhibition of RAF and DDR1/2 signaling [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 4657.

Abstract 3335: A novel and potent IRE1α RNase inhibitor, HM100168 as a promising therapeutic strategy in solid cancers

Abstract Protein folding homeostasis in the endoplasmic reticulum (ER) is regulated by a signaling network called the unfolded protein response (UPR). Inositol-requiring enzyme 1α (IRE1α) is an ER membrane-resident kinase/RNase that mediates signal transmission in the most evolutionarily conserved way of the UPR. The IRE1α-XBP1 pathway, one of the most essential branches of the UPR, is activated in various types of cancer. When IRE1α is activated, the spliced form of XBP1 (XBP1s) is generated to activate the transcription of many pro-survival genes to prevent cellular death and relieve cellular stress. IRE1α plays an instrumental pro-tumoral role in various cancers, such as glioblastoma, myeloma, lung adenocarcinoma, and breast cancers, as well as high IRE1α activity is associated with poor prognoses. Moreover, IRE1-XBP1 plays an essential role in the UPR and ER stress responses, which have been implicated in the development of drug resistance. Thereby, blockade of the IRE1α-XBP1 pathway is crucial as it is considered as a potential anti-cancer strategy. Here, we developed a potent and selective IRE1α RNase inhibitor, which have a hydroxy-aryl-aldehydes (HAA) moiety that binds to IRE1α within the RNase catalytic site. Our lead compound, HM100168, potently inhibited the RNase activity of human IRE1α at nanomolar concentrations without affecting its kinase activity. Experiments were performed on MCF7 breast cancer cells to confirm the inhibitory effect in the mRNA and protein levels of XBP1s, which was increased by tunicamycin (TM), a ER stress inducer. HM100168 strongly inhibited ​​XBP1s levels in a dose-dependent manner, displaying the potent IC50 values. We tested cell growth inhibition activity in 3D as well as 2D cell culture condition of various cancer cell lines. Interestingly, HM100168 effectively inhibited cell proliferation of diverse cancer cell lines in both 2D and 3D culture condition. In addition, we explored the promising anti-cancer effects of HM100168 and its synergistic potential when combined with anti-tumorigenic agents. As a result, HM100168 in combination with anti-tumorigenic agents significantly enhanced suppression of tumor growth in human cancer cell transplanted mice. In conclusion, we have identified a novel compound with unique properties that specifically blocked the endonuclease activity of IRE1α. HM100168 inhibited IRE1α endonuclease activity, without affecting its kinase activity after endoplasmic reticulum stress in vitro. The identification of this novel IRE1α inhibitor supports the hypothesis that the IRE1α-XBP1 axis is a promising target for anticancer therapy. Also, co-targeting of IRE1α-XBP1 in combination with anti-tumorigenic agents can be considered a novel approach to overcome cancer resistance. Further preclinical studies will be performed and reported soon after the establishment of a preclinical candidate. Citation Format: Jisook Kim, Seung Hyun Jung, Minjeong Kim, Wongi Park, Jooyun Byun, Soonki Park, Miyoung Lee, Yu-Yon Kim, Junghwa Park, Seokhyun Hong, Minhwa Kim, Young Gil Ahn. A novel and potent IRE1α RNase inhibitor, HM100168 as a promising therapeutic strategy in solid cancers [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 3335.

Raludotatug Deruxtecan, a CDH6-Targeting Antibody-Drug Conjugate with a DNA Topoisomerase I Inhibitor DXd, Is Efficacious in Human Ovarian and Kidney Cancer Models.

Cadherin-6 (CDH6) is expressed in several cancer types, but no CDH6-targeted therapy is currently clinically available. Here, we generated raludotatug deruxtecan (R-DXd; DS-6000), a novel CDH6-targeting antibody-drug conjugate with a potent DNA topoisomerase I inhibitor, and evaluated its properties, pharmacologic activities, and safety profile. In vitro pharmacologic activities and the mechanisms of action of R-DXd were assessed in serous-type ovarian cancer and renal cell carcinoma cell lines. In vivo pharmacologic activities were evaluated with several human cancer cell lines and patient-derived xenograft mouse models. The safety profile in cynomolgus monkeys was also assessed. R-DXd exhibited CDH6 expression-dependent cell growth-inhibitory activity and induced tumor regression in xenograft models. In this process, R-DXd specifically bound to CDH6, was internalized into cancer cells, and then translocated to the lysosome. The DXd released from R-DXd induced the phosphorylation of Chk1, a DNA damage marker, and cleaved caspase-3, an apoptosis marker, in cancer cells. It was also confirmed that the DXd payload had a bystander effect, passing through the cell membrane and impacting surrounding cells. The safety profile of R-DXd was favorable and the highest non-severely toxic dose was 30 mg/kg in cynomolgus monkeys. R-DXd demonstrated potent antitumor activity against CDH6-expressing tumors in mice and an acceptable safety profile in monkeys. These findings indicate the potential of R-DXd as a new treatment option for patients with CDH6-expressing serous-type ovarian cancer and renal cell carcinoma in a clinical setting.

Block Synthesis and Step-Growth Polymerization of C-6-Sulfonatomethyl-Containing Sulfated Malto-Oligosaccharides and Their Biological Profiling.

Highly sulfated malto-oligomers, similar to heparin and heparan-sulfate, have good antiviral, antimetastatic, anti-inflammatory and cell growth inhibitory effects. Due to their broad biological activities and simple structure, sulfated malto-oligomer derivatives have a great therapeutic potential, therefore, the development of efficient synthesis methods for their production is of utmost importance. In this work, preparation of α-(1→4)-linked oligoglucosides containing a sulfonatomethyl moiety at position C-6 of each glucose unit was studied by different approaches. Malto-oligomeric sulfonic acid derivatives up to dodecasaccharides were prepared by polymerization using different protecting groups, and the composition of the product mixtures was analyzed by MALDI-MS methods and size-exclusion chromatography. Synthesis of lower oligomers was also accomplished by stepwise and block synthetic methods, and then the oligosaccharide products were persulfated. The antiviral, anti-inflammatory and cell growth inhibitory activity of the fully sulfated malto-oligosaccharide sulfonic acids were determined by in vitro tests. Four tested di- and trisaccharide sulfonic acids effectively inhibited the activation of the TNF-α-mediated inflammatory pathway without showing cytotoxicity.

Anticancer Activity of Rosella Flowers (Hibiscus Sabdariffa l.) In HepG2 cells

The natural ingredients of rosella flowers have the potential as natural anti-cancer and chemopreventive agents, contain secondary metabolite compounds with cancer therapeutic mechanisms with inhibiting and killing cancer cells and their development through inhibition of apoptosis (cell death program) and in vitro inhibited cell flow. The study aims to identification of secondary metabolite compounds and also determine the cytotoxic activity of ethanol extract from the rosemary plant against HepG2 cancer cells. This study used by identification of secondary metabolite compounds of ethanol extract from the rosemary plant (Hibiscus sabdariffa L.) and the cytotoxicity test used with MTT assay on HepG2 liver cancer cells with a test concentration series of 12,5; 25; 50; 100; 200; 250; 500 and 1000 µg/ml. : The results showed the secondary metabolite compounds of rosella flowers have flavonoids, alkaloids, saponins and tannins and data of 50% cell growth inhibition activity, which was showed that rosella flower had IC50 values 629,919 μg/mL. The ethanol extract of rosella flowers have activity on HepG2 cells growth inhibition had considered moderately active anticancer activity

Synthesis and biological evaluation of (2‐aminosulfonylpyridin‐6‐yl)pyrazolopyrimidinone derivatives as Wee1 inhibitors for cancer treatment

AbstractFor an analog‐based design of novel Wee1 inhibitors, we profiled in vitro ADMET and in vivo PK properties of adavosertib. Based on the properties of adavosertib, we aimed to improve its metabolic stability by designing a novel target compound 1a with an aminosulfonyl group instead of the 2‐hydroxypropan‐2‐yl moiety in adavosertib. Derivatives of target compound 1a were synthesized and evaluated for Wee1 enzyme inhibition and liver microsomal phase I stability. We identified compound 1a as a sub‐nanomolar Wee1 inhibitor and 10 additional compounds with one‐digit nanomolar Wee1 inhibitory activity, among which seven compounds including 1a exhibited improved metabolic stabilities compared with adavosertib. However, MDA‐MB‐231 cell growth inhibitory activities of all synthesized compounds and Wee1 substrate phosphorylation inhibitory activities of selected compounds were inferior to adavosertib overall. Moreover, the representative compound 1a exhibited low permeability, which may be the reason for the low cellular activities of compound 1a.

Novel sulindac derivatives for colorectal cancer chemoprevention that target cGMP phosphodiesterases to suppress Wnt/β-catenin transcriptional activity

<p class="MsoNormal" style="margin-top: 6pt; line-height: 13pt; text-align: justify;"><span lang="EN-US" style="font-size: 10pt; font-family: arial, helvetica, sans-serif;">Approximately 28 million individuals in the United States face the risk of developing precancerous colonic adenomas (polyps) and potentially progressing to colorectal cancer (CRC). While a promising strategy for CRC prevention involves pharmacological intervention, such as cancer chemoprevention or interception, currently, there are no FDA-approved drugs capable of preventing the formation or progression of adenomas to adenocarcinoma. Numerous clinical, epidemiological, and preclinical studies have offered compelling evidence supporting the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) in CRC chemoprevention. However, the prolonged use of NSAIDs is not FDA-approved due to potential life-threatening toxicities resulting from cyclooxygenase (COX) inhibition and the depletion of physiological prostaglandins. Despite indications that the COX inhibitory activity of NSAIDs may not be essential for their antineoplastic effects, the absence of a well-defined target impeded the development of derivatives that do not inhibit COX. Earlier research suggests that the inhibition of cyclic guanosine monophosphate phosphodiesterase (cGMP PDE) may be responsible, at least in part, for the antineoplastic activity of the NSAID sulindac. This could potentially offer a novel target for CRC chemoprevention. To identify the cGMP PDE isozyme(s) contributing to the antineoplastic activity of sulindac, we synthesized a chemically diverse library of over 1500 compounds, all sharing the indene scaffold of sulindac. Subsequently, we screened these compounds for their impact on cancer cell growth and PDE inhibitory activity. From this screening, a series of lead compounds emerged. These compounds lacked COX-1 and COX-2 inhibitory activity, surpassing sulindac in potency to inhibit CRC cell growth. Importantly, they demonstrated greater selectivity by not affecting normal cell growth. Through chemical optimization, we identified several development candidates that selectively inhibit PDE5 and/or PDE10. These compounds activate cGMP/PKG signaling, suppressing Wnt/β-catenin transcription. This action counters the growth advantages resulting from APC or CTNNB1 mutations, which are responsible for most human CRCs. This review delves into the scientific literature supporting PDE5 and/or PDE10 as potential targets for CRC chemoprevention or interception. Our findings suggest a promising avenue for developing drugs that may effectively intervene in the progression of colorectal cancer, offering hope for improved preventive strategies in the future.</span></p>

Novel sulindac derivatives for colorectal cancer chemoprevention that target cGMP phosphodiesterases to suppress Wnt/β-catenin transcriptional activity

<p class="MsoNormal" style="margin-top: 6pt; line-height: 13pt; text-align: justify;"><span lang="EN-US" style="font-size: 10pt; font-family: arial, helvetica, sans-serif;">Approximately 28 million individuals in the United States face the risk of developing precancerous colonic adenomas (polyps) and potentially progressing to colorectal cancer (CRC). While a promising strategy for CRC prevention involves pharmacological intervention, such as cancer chemoprevention or interception, currently, there are no FDA-approved drugs capable of preventing the formation or progression of adenomas to adenocarcinoma. Numerous clinical, epidemiological, and preclinical studies have offered compelling evidence supporting the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) in CRC chemoprevention. However, the prolonged use of NSAIDs is not FDA-approved due to potential life-threatening toxicities resulting from cyclooxygenase (COX) inhibition and the depletion of physiological prostaglandins. Despite indications that the COX inhibitory activity of NSAIDs may not be essential for their antineoplastic effects, the absence of a well-defined target impeded the development of derivatives that do not inhibit COX. Earlier research suggests that the inhibition of cyclic guanosine monophosphate phosphodiesterase (cGMP PDE) may be responsible, at least in part, for the antineoplastic activity of the NSAID sulindac. This could potentially offer a novel target for CRC chemoprevention. To identify the cGMP PDE isozyme(s) contributing to the antineoplastic activity of sulindac, we synthesized a chemically diverse library of over 1500 compounds, all sharing the indene scaffold of sulindac. Subsequently, we screened these compounds for their impact on cancer cell growth and PDE inhibitory activity. From this screening, a series of lead compounds emerged. These compounds lacked COX-1 and COX-2 inhibitory activity, surpassing sulindac in potency to inhibit CRC cell growth. Importantly, they demonstrated greater selectivity by not affecting normal cell growth. Through chemical optimization, we identified several development candidates that selectively inhibit PDE5 and/or PDE10. These compounds activate cGMP/PKG signaling, suppressing Wnt/β-catenin transcription. This action counters the growth advantages resulting from APC or CTNNB1 mutations, which are responsible for most human CRCs. This review delves into the scientific literature supporting PDE5 and/or PDE10 as potential targets for CRC chemoprevention or interception. Our findings suggest a promising avenue for developing drugs that may effectively intervene in the progression of colorectal cancer, offering hope for improved preventive strategies in the future.</span></p>

Green synthesis and anti-tumor efficacy via inducing pyroptosis of novel 1H-benzo[e]indole-2(3H)-one spirocyclic derivatives

Pyroptosis induction is anticipated to be a new approach to developing anti-tumor medications. A novel class of spirocyclic compounds was designed by hybridization of 1H-Benzo[e]indole-2(3H)-one with 1,4-dihydroquinoline and synthesized through a new green “one-pot” synthesis method using 10 wt% SDS/H2O as a solvent to screen novel tumor cell pyroptosis inducers. The anti-tumor activity of all compounds in vitro was determined by the MTT method, and a fraction of the compounds showed good cell growth inhibitory activity. The quantitative structure–activity relationship models of the compounds were established by artificial intelligence random forest algorithm (R2 = 0.9656 and 0.9747). The ideal compound A9 could, in a concentration-dependent manner, prevent ovarian cancer cells from forming colonies, migrating, and invading. Furthermore, A9 could significantly induce pyroptosis and upregulate the expression of pyroptosis-related proteins GSDME-N, in addition to inducing apoptosis and mediating the expression of apoptosis-related proteins in ovarian cancer cells. A9 (5 mg/kg) significantly reduced tumor volume and weight of ovarian cancer in vivo, decreased caspase-3 expression in tumor tissue, and induced the production of GSDME-N. This study provides a green and efficient atom-economic synthesis method for 1H-Benzo[e]indole-2(3H)-one spirocyclic derivatives and a promising pyroptosis inducer with anti-tumor activity.

Discovery of Selective Histone Deacetylase 1 and 2 Inhibitors: Screening of a Focused Library Constructed by Click Chemistry, Kinetic Binding Analysis, and Biological Evaluation.

Histone deacetylase 1 and 2 (HDAC1/2) inhibitors are potentially useful as tools for probing the biological functions of the isoforms and as therapeutic agents for cancer and neurodegenerative disorders. To discover potent and selective inhibitors, we screened a focused library synthesized by using click chemistry and obtained KPZ560 as an HDAC1/2-selective inhibitor. Kinetic binding analysis revealed that KPZ560 inhibits HDAC2 through a two-step slow-binding mechanism. In cellular assays, KPZ560 induced a dose- and time-dependent increase of histone acetylation and showed potent breast cancer cell growth-inhibitory activity. In addition, gene expression analyses suggested that the two-step slow-binding inhibition by KPZ560 regulated the expression of genes associated with cell proliferation and DNA damage. KPZ560 also induced neurite outgrowth of Neuro-2a cells and an increase in the spine density of granule neuron dendrites of mice. The unique two-step slow-binding character of o-aminoanilides such as KPZ560 makes them interesting candidates as therapeutic agents.

OR2802 A Novel CABLES1 Missense Variant Associated With Cushing's Disease Disrupts Protein Structure And Stability

Abstract Disclosure: A.L. Franco-Álvarez: None. M. Torres Morán: None. R.G. Rebollar-Vega: None. N. Pankratz: None. J. Lane: None. F.R. Faucz: None. P. Chittiboina: None. D.M. Kay: None. J.L. Mills: None. C.A. Stratakis: None. L.C. Hernández-Ramírez: None. Introduction. The adrenal-pituitary feedback loop is disrupted in Cushing's disease (CD). One of the glucocorticoid-responsive genes participating in this regulatory pathway is the negative cell cycle regulator CABLES1. We have previously reported five germline missense CABLES1 variants associated with CD and macroadenomas: two in young adults (p.E178K and p.L240F), two in children (p.G312D and p.D463G), and one in a middle-aged adult (p.P31L). The first four variants resulted in loss of the cell growth inhibition activity, but the fifth one has not been functionally validated. Aims. To report in detail a case of CD associated with the CABLES1 p.P31L variant and to characterize the molecular consequences of this variant using in silico and in vitro approaches. Methods. Variant detection was done via exome sequencing. Immunohistochemistry for CDKN1B and CABLES1 was performed on pituitary tumor slides. Loss of heterozygosity for CABLES1 p.P31L and common somatic variants were investigated in the tumor tissue. Protein stability studies were done for the CABLES1 variants p.P31L, p.L240F, p.G312D and p.D463G transiently expressed in HEK293 cells, using the cycloheximide chase method. The interaction of the CABLES1 variants with CDK2 was analyzed by transient expression in HEK293 cells and co-immunoprecipitation. Results. The p.P31L variant was found in a 53-year-old woman with CD. She achieved remission after resection of a macroadenoma (reported as a null-cell tumor). Recurrence one year later prompted a reintervention, and this a 60 mm Crooke cell adenoma was resected, again with postoperative remission. The p.P31L variant is of uncertain significance according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology criteria. The affected residue (P31) is part of a PPP motif that lies within a proline-rich region of CABLES1 (residues 30-52) within the N-terminal disorder, with unknown functional role. By immunohistochemistry, the corticotropinoma retained CABLES1 expression, but had lost 70% of CDKN1B expression. Loss of heterozgosity for CABLES1 p.P31L, as well as and hotspot BRAF, USP8, and USP48 were negative in the tumor. The p.P31L variant had an increased degradation constant (0.13±0.04) and a reduced half-life (5.80±1.93 hours), compared with wild type CABLES1 (degradation constant of 0.06± 0.02 and half-life of 13.52 ±5.11 hours; P=0.0036 for degradation constant and P=0.0091 for half-life). The rest of variants showed no significant differences. All variants retained their ability to interact with CDK2. Conclusions. The CABLES1 p.P31L variant encodes an unstable protein with a reduced half-life, which accordingly may result into a reduced tumor suppressor effect. Further studies are required to fully understand how CABLES1 loss of function impacts corticotroph cell growth. Presentation: Sunday, June 18, 2023

Evaluation of in vitro antiplasmodial, antiproliferative activities, and in vivo oral acute toxicity of Spathodea campanulata flowers

Spathodea campanulata is used in traditional medicine to treat various ailments such as malaria, human immunodeficiency virus (HIV), cancer, fever and urethral inflammation. The aim of this study was to investigate the antiplasmodial, and antiproliferative activities of the extract and resulted fractions from S. campanulata flowers, as well as assessing the acute toxicity of its aqueous fraction. The in vitro cell-growth inhibition activities were assessed against Plasmodium falciparum strain 3D7 for antimalarial activity and three cancer cell lines: Hs683 (human oligodendroglioma), MCF7 (human breast carcinoma), and murine B16F10 (mouse melanoma) for antiproliferative activity while the in vivo acute oral toxicity was determined according to the modified organisation for Economic Co-operation and Development (OECD) guidelines 423 at a fixed dose on Female Wistar strain laboratory rats. The dichloromethane, ethyl acetate and hexane fractions at a concentration of 25 µg/mL each significantly reduced the viability of 3D7 Plasmodium cells with viability percentages of 19.0%, 14.1% and 31.9%, respectively, and IC50 of 28.1, 30.2 and 29.7 µg/mL, respectively. The ethyl acetate fraction showed a moderate antiproliferative activity on mouse melanoma with an I50 value of 54.6 µg/mL. Only the dichloromethane fraction was able to inhibit the 3 cell lines tested with IC50 values less than 15 µg/mL. An oral administration of the aqueous fraction did not induce an abnormal variation of the physiological parameters in female Wistar laboratory rats, at non-toxic doses up to 5000 mg/kg body weight for 14 days. These results confirm the use of this plant in traditional medicine for its antimalarial and anticancer potential.

Discovery of SMD-3040 as a Potent and Selective SMARCA2 PROTAC Degrader with Strong in vivo Antitumor Activity.

SMARCA2 is an attractive synthetic lethality target for human cancers with SMARCA4 deficiency. Herein, we report the design, synthesis, and biological evaluation of selective SMARCA2 protein degraders developed using the proteolysis targeting chimera (PROTAC) technology. Our efforts have led to the discovery of a series of potent and selective SMARCA2 degraders, exemplified by SMD-3040. SMD-3040 degrades SMARCA2 protein with a low nanomolar DC50 and Dmax > 90% and demonstrates an excellent degradation selectivity for SMARCA2 protein over SMARCA4 protein. It displays potent cell growth inhibitory activity in a panel of SMARCA4-deficient cancer cell lines and has much weaker activity in SMARCA4 wild-type cancer cell lines. SMD-3040 achieves strong tumor growth inhibition in two SMARCA4-deficient xenograft models at well-tolerated dose schedules. Further optimization of SMD-3040 may lead to the discovery of new therapies for the treatment of human cancers with SMARCA4 deficiency.