Antitumor Potential Research Articles

Hyperconjugation‐Driven Isodesmic Reaction of Indoles and Anilines: Reaction Discovery, Mechanism Study, and Antitumor Application

AbstractIsodesmic reactions, in which chemical bonds are redistributed between substrates and products, provide a general and powerful strategy for both biological and chemical synthesis. However, most isodesmic reactions involve either metathesis or functional‐group transfer. Here, we serendipitously discovered a novel isodesmic reaction of indoles and anilines that proceeds intramolecularly under weakly acidic conditions. In this process, the five‐membered ring of the indole motif is broken and a new indole motif is constructed on the aniline side, accompanied by the formation of a new aniline motif. Mechanistic studies revealed the pivotal role of σ→π* hyperconjugation on the nitrogen atom of the indole motif in driving this unusual isodesmic reaction. Furthermore, we successfully synthesized a diverse series of polycyclic indole derivatives; among quinolines, potential antitumor agents were identified using cellular and in vivo experiments, thereby demonstrating the synthetic utility of the developed methodology.

Maturity and density of tertiary lymphoid structures associate with tumor metastasis and chemotherapy response.

Tertiary Lymphoid Structures (TLSs) are abnormal clusters of immune cells that form in tissues not normally associated with the immune system, usually in cases of long-lasting inflammation, like cancer. TLSs have been suggested as a potential prognostic indicator in various cancer types. We retrospectively enrolled 223 gastric cancer (GC) patients who had surgical resections in this study. We utilized hematoxylin and eosin (HE) staining to detect the presence, abundance, and maturity of TLSs. In serial sections, we used immunohistochemistry to examine the cellular composition of TLSs. The pathological review identified TLSs in 95.1% of the tumors, lymphoid aggregates in 79.8%, primary follicles in 45.7%, and lymphoid aggregates in 95.1% of the cases. Based on Kaplan-Meier curves, the maturation and abundance of TLSs contributed to longer disease-free survival (DFS) and overall survival (OS). In addition, the density of TLSs was strongly associated with the occurrence of tumor metastases and the response to adjuvant chemotherapy. We validated the prognostic value of TLSs in GC patients in both independent cohorts, and the maturity and density of TLS correlated with tumor metastasis. In addition, TLS may reflect sustained antitumor potency, which has important implications for adjuvant chemotherapy.

Design, synthesis and biological evaluation of novel benzimidazole-derived p21-activited kinase 4 (PAK4) inhibitors bearing a 4-(4-methylpiperazin-1-yl)phenyl scaffold as potential antitumor agents

A series of novel 6-(4-(4-methylpiperazin-1-yl)phenyl)-1H-benzo[d]imidazole-based p21-activited kinase 4 (PAK4) inhibitors were designed and synthesized based on the structure of lead compound GNE-2861 and that of anticancer inhibitors reported in our previous studies. All target compounds so designed were preliminarily screened in vitro for anti-tumor potency through kinase inhibitory assays and MTT assays, which revealed that most compounds exhibited significant inhibitory effects on PAK4 enzyme as well as prominent antiproliferative activities against four cancer cell models (A549, NCI–H1975, MDA-MB-231 and SK-BR-3) and low damage to healthy cells. In particular, the hit compound 12i was identified as the most effective and rather selective compound both at the enzyme and cellular level. Meanwhile, molecular docking and dynamic studies disclosed that compound 12i could bind to PAK4 stably via multiple interactions applied between the compound and the enzyme. Further mechanism studies indicated that compound 12i could inhibit the proliferation and suppress the migratory potential of MDA-MB-231 cells by inhibiting the phosphorylation of PAK4 and LIMK1, arresting cell cycle in the G0/G1 phase, inducing apoptosis and promoting ROS production. Notably, compound 12i could effectively inhibit triple-negative breast cancer (TNBC) growth with little toxicity in the MDA-MB-231 cell xenograft model. Taken together, in vitro and in vivo results demonstrated that compound 12i possessed high drug potential as an inhibitor of PAK4 to inhibit the growth and metastasis of TNBC.

Antitumor activity of PAbs generated by immunization with a novel HER3-targeting protein-based vaccine candidate in preclinical models.

Despite the cumulative evidence supporting HER3 as a target for antitumor therapies, no agents targeting HER3 have been approved for cancer treatment. Most of the agents evaluated in preclinical and clinical trials have been specific monoclonal antibodies (MAbs), with few examples of active immunotherapy directed against this receptor. However, some cancer vaccine formats may generate polyclonal antibodies (PAbs) that replicate the diverse effector mechanisms of MAbs, including ligand neutralization and receptor degradation. In this study, we developed a protein subunit-based monovalent vaccine candidate targeting the extracellular domain (ECD) of HER3. Immunization of mice with a formulation targeting murine ErbB3-ECD successfully overcome tolerance to this self-antigen, inducing high titers of ErbB3-specific PAbs. The antitumor potential of this formulation and the induced PAbs was demonstrated in vivo and in vitro in an ErbB3-overexpressing 3LL-D122-derived tumor model. The immunogenicity of the HER3-ECD-based vaccine candidate was confirmed by the induction of high titers of HER3-specific PAbs. Consistent with the initial results, HER3-ECD-targeting PAbs were cytotoxic in several human epithelial tumor cell lines and exerted antitumor effects in vivo. These results support the value of HER3 as a tumor antigen and the effector mechanisms of HER3-specific therapeutic MAbs, while suggesting the potential of the proposed vaccine candidate for the treatment of HER3-expressing carcinomas.

Anti-tumor activity of camptothecin analog conjugate of a RSPO4-based peptibody targeting LGR4/5/6 in preclinical models of colorectal cancer.

Antibody-drug conjugates (ADCs) have emerged as a major modality of targeted cancer therapy, yet no ADC has been approved for colorectal cancer (CRC). LGR4/5/6 (leucine-rich repeat containing, G protein-coupled receptor 4, 5, 6) are three related receptors that are expressed at high levels together or alternately in nearly all cases of CRC. ADCs targeting LGR5 have been shown to have robust anti-tumor potency, but not all CRC cells express LGR5 and LGR5-positive tumor cells may lose LGR5 expression due to cancer cell plasticity. R-spondin 4 (RSPO4) is a natural protein ligand of LGR4/5/6 with high affinity for all three receptors. We fused a mutant form of RSPO4 that retains high affinity binding to LGR4/5/6 to IgG1 Fc to create a peptibody designated R462. Conjugation of R462 with a camptothecin analog (CPT2) at eight drugs per peptibody led to the synthesis of R462-CPT2 that showed highly potent cytotoxic activity in vitro in CRC cell lines expressing any of LG4/5/6. In cell line xenograft and PDX models of CRC, R462-CPT2 demonstrated robust anti-tumor effect. Importantly, R462-CPT2 showed no major adverse effect at therapeutically effective dose levels. These results strongly support the use of RSPO ligand drug-conjugates that target LGR4/5/6 simultaneously for the treatment of CRC.

In Silico Approach for Assessment of the Anti-Tumor Potential of Cannabinoid Compounds by Targeting Glucose-6-Phosphate Dehydrogenase Enzyme.

Glucose-6-phosphate dehydrogenase (G6PD) is a pentose phosphate pathway (PPP) enzyme that generates NADPH, which is required for cellular redox equilibrium and reductive biosynthesis. It has been demonstrated that abnormal G6PD activation promotes cancer cell proliferation and metastasis. To date, no G6PD inhibitor has passed clinical testing successfully enough to be launched as a medicine. As a result, in this investigation, cannabinoids were chosen to evaluate their anticancer potential by targeting G6PD. Molecular docking indicated that three molecules, Tetrahydrocannabinolic acid (THCA), Cannabichromenic acid (CBCA), and tetrahydrocannabivarin (THCV), have the highest binding affinities for G6PD of -8.61, -8.39, and 8.01 Kcal mol. ADMET analysis found that all of them were safe prospective drug candidates. Molecular dynamics (MD) simulation and MM-PBSA analysis confirm the structural compactness and lower conformational variation of protein-ligand complexes, thereby maintaining structural stability and rigidity. Thus, our in silico investigation exhibited all three cannabinoids as potential competitive inhibitors of G6PD.

GLUT1 overexpression in CAR-T cells induces metabolic reprogramming and enhances potency

The intensive nutrient requirements needed to sustain T cell activation and proliferation, combined with competition for nutrients within the tumor microenvironment, raise the prospect that glucose availability may limit CAR-T cell function. Here, we seek to test the hypothesis that stable overexpression (OE) of the glucose transporter GLUT1 in primary human CAR-T cells would improve their function and antitumor potency. We observe that GLUT1OE in CAR-T cells increases glucose consumption, glycolysis, glycolytic reserve, and oxidative phosphorylation, and these effects are associated with decreased T cell exhaustion and increased Th17 differentiation. GLUT1OE also induces broad metabolic reprogramming associated with increased glutathione-mediated resistance to reactive oxygen species, and increased inosine accumulation. When challenged with tumors, GLUT1OE CAR-T cells secrete more proinflammatory cytokines and show enhanced cytotoxicity in vitro, and demonstrate superior tumor control and persistence in mouse models. Our collective findings support a paradigm wherein glucose availability is rate limiting for effector CAR-T cell function and demonstrate that enhancing glucose availability via GLUT1OE could augment antitumor immune function.

An Exogenous Ketone Ester Slows Tumor Progression in Murine Breast and Renal Cancer Models.

Ketone esters (KEs) exhibit promise as anti-cancer agents but their impact on spontaneous metastases remains poorly understood. Although consumption of a ketogenic diet (KD) that is low in carbohydrates and high in fats can lead to KE production in vivo, the restrictive composition of KDs may diminish adherence in cancer patients. We investigated the effects of an exogenous ketone ester-supplemented (eKET), carbohydrate-replete diet on tumor growth, metastasis, and underlying mechanisms in orthotopic models of metastatic breast (4T1-Luc) and renal (Renca-Luc) carcinomas. Mice were randomized to diet after tumor challenge. Administration of KEs did not alter tumor cell growth in vitro. However, in mice, our eKET diet increased circulating β-hydroxybutyrate and inhibited primary tumor growth and lung metastasis in both models. Body composition analysis illustrated the overall safety of eKET diet use, although it was associated with a loss of fat mass in mice with renal tumors. Immunogenetic profiling revealed divergent intratumoral eKET-related changes by tumor type. In mammary tumors, Wnt and TGFβ pathways were downregulated, whereas in renal tumors, genes related to hypoxia and DNA damage repair were downregulated. Thus, our eKET diet exerts potent antitumor and antimetastatic effects in both breast and renal cancer models, albeit with different modes of action and physiologic effects. Its potential as an adjuvant dietary approach for patients with diverse cancer types should be explored further.

Design, Synthesis, and Biological Evaluation of Novel Apigenin Derivatives as Potential Antitumor Agents

Design, Synthesis, and Biological Evaluation of Novel Apigenin Derivatives as Potential Antitumor Agents

29 (PB017): A novel small molecule activator of the integrated stress response kinase GCN2 shows potent preclinical antitumor activity as monotherapy and in combination with standard of care agents

29 (PB017): A novel small molecule activator of the integrated stress response kinase GCN2 shows potent preclinical antitumor activity as monotherapy and in combination with standard of care agents

Epigallocatechin-3-gallate Synergistically Inhibits the Proliferation of Lung Cancer Cells with Gemcitabine by Induction of Apoptosis Mediated by ROS Generation.

The present study focused on the formulation, characterization, and evaluation of solid lipid nanoparticles (SLNs) loaded with gemcitabine (GEM) and epigallocatechin-3-gallate (EGCG) for lung cancer treatment. A 2-level, 3-factor factorial design was used to optimize various process parameters in the preparation of SLNs. The average particle size and polydispersity index (PDI) of GEM-EGCG SLNs were found to be 122.8 ± 8.02 and 0.1738 ± 0.02, respectively. Drug loading and release studies indicated a sustained release behavior for GEM-EGCG SLNs, with release kinetics confirmed by the Higuchi model. Cell viability and anticancer activities were assessed using the MTT assay, which determined an IC50 value of 12.5 μg/mL for GEM-EGCG SLNs against A549 cell lines (lung carcinoma epithelial cells). The SLNs were able to internalize into the nuclei of cells, likely due to their small particle size, and were effective in killing cancer cells. Additionally, a study of ROS production-mediated apoptosis of A549 cells was performed through FACS. GEM-EGCG SLNs were found to be stable for 3 months. In vivo studies revealed better drug distribution in the lungs and improved pharmacokinetic profile compared with pure drugs. Overall, the results suggest that combining GEM and EGCG in biocompatible SLNs has resulted in synergistic antitumor potential and improved bioavailability for both drugs, making it a promising anticancer therapeutic regimen against lung cancer.

Re-Assessing the Role of Platelet Activating Factor and Its Inflammatory Signaling and Inhibitors in Cancer and Anti-Cancer Strategies.

Since 2000s, we have outlined the multifaceted role of inflammation in several aspects of cancer, via specific inflammatory mediators, including the platelet activating factor (PAF) and PAF-receptor (PAFR) related signaling, which affect important inflammatory junctions and cellular interactions that are associated with tumor-related inflammatory manifestations. It is now well established that disease-related unresolved chronic inflammatory responses can promote carcinogenesis. At the same time, tumors themselves are able to promote their progression and metastasis, by triggering an inflammation-related vicious cycle, in which PAF and its signaling play crucial role(s), which usually conclude in tumor growth and angiogenesis. In parallel, new evidence suggests that PAF and its signaling also interact with several inflammation-related cancer treatments by inducing an antitumor immune response or, conversely, promoting tumor recurrence. Within this review article, the current knowledge and future perspectives of the implication of PAF and its signaling in all these important aspects of cancer are thoroughly re-assessed. The potential beneficial role of PAF-inhibitors and natural or synthetic modulators of PAF-metabolism against tumors, tumor progression and metastasis are evaluated. Emphasis is given to natural and synthetic molecules with dual anti-PAF and anti-cancer activities (Bio-DAPAC-tives), with proven evidence of their antitumor potency through clinical trials, as well as on metal-based anti-inflammatory mediators that constitute a new class of potent inhibitors. The way these compounds may promote anti-tumor effects and modulate the inflammatory cellular actions and immune responses is also discussed. Limitations and future perspectives on targeting of PAF, its metabolism and receptor, including PAF-related inflammatory signaling, as part(s) of anti-tumor strategies that involve inflammation and immune response(s) for an improved outcome, are also evaluated.

Targeting HSP90 for Cancer Therapy: Current Progress and Emerging Prospects.

Heat shock protein 90 (HSP90), a highly conserved member of the heat shock protein family, regulates various proteins and signaling pathways involved in cancer, making it a promising target for cancer therapy. Traditional HSP90 inhibitors have demonstrated significant antitumor potential in preclinical trials, with over 20 compounds advancing to clinical trials and showing promising results. However, the limited clinical efficacy and shared toxicity of these inhibitors restrict their further clinical use. Encouragingly, developing novel inhibitors using conventional medicinal chemistry approaches─such as selective inhibitors, dual inhibitors, protein-protein interaction inhibitors, and proteolysis-targeting chimeras─is expected to address these challenges. Notably, the selective inhibitor TAS-116 has already been successfully marketed. In this Perspective, we summarize the structure, biological functions, and roles of HSP90 in cancer, analyze the clinical status of HSP90 inhibitors, and highlight the latest advancements in novel strategies, offering insights into their future development.

Evaluation of the Bioactive Compounds of Apis mellifera Honey Obtained from the Açai (Euterpe oleracea) Floral Nectar.

The biodiversity of Brazil provides an excellent climate and favorable pollination conditions for Apis mellifera L., especially in the Eastern Amazon region, which boasts vast floral wealth, including an abundance of açaí (Euterpe oleracea) flowers and fruits. In the present study, seven types of honey were evaluated: three containing floral nectar from açaí (Açaí honey) collected in the Eastern Amazon region (Açaí honey from Breu Branco (AH1 and AH2) and Açaí honey from Santa Maria (AH3), both from the state of Pará, Brazil) and four honeys from different regions of Brazil (Aroeira honey from Minas Gerais, Cipó-Uva honey from Distrito Federal, Mangue honey from Pará, and Timbó honey from Rio Grande do Sul). The characteristics of these honeys were evaluated by examining their physicochemical properties, melissopalynological aspects, color, antioxidant potential, and their constituent compounds, which were confirmed through GC-MS analysis. Açaí floral nectar honeys presented physicochemical results similar to those of other honeys, aligning with Brazilian legislation norms, but differed in their high values of free acidity, apparent sugars, and lower reducing sugars, which are directly related to their botanical origin. These differences correlate with unique flavor and distinct aroma characteristics. Melissopalynological analysis confirmed the botanical origin of the honeys containing açaí floral nectar, which had a color range from amber to dark amber. The three açaí honeys demonstrated high antioxidant capacity and superior flavonoid and polyphenol content compared to other honeys, particularly the açaí honey from Breu Branco (AH1), which had four times the content to combat free radicals compared to the honey with the highest potential (Aroeira honey). GC-MS analysis confirmed the presence of antioxidant properties as well as potential anti-inflammatory, antibacterial, antimicrobial, and antitumor capabilities in açaí honeys, which have not yet been fully studied.

Antitumoral and Antiproliferative Potential of Synthetic Derivatives of Scorpion Peptide IsCT1 in an Oral Cavity Squamous Carcinoma Model.

The oral cavity is a frequent site for head and neck cancers, which rank as the sixth most common cancer globally, with a 5-year survival rate slightly over 50%. Current treatments are limited, and resistance to therapy remains a significant clinical obstacle. IsCT1, a membrane-active peptide derived from the venom of the scorpion Opisthacanthus madagascariensis, has shown antitumor effects in various cancer cell lines, including breast cancer and chronic myeloid leukemia. However, its hemolytic action limits its potential therapeutic use. This study aims to assess the antitumor and antiproliferative activities of synthetic peptides derived from IsCT1 (IsCT-P, AC-AFPK-IsCT1, AFPK-IsCT1, AC-KKK-IsCT1, and KKK-IsCT1) in the context of oral squamous cell carcinoma. We evaluated the cytotoxic effects of these peptides on tongue squamous cell carcinoma cells and normal cells, as well as their impact on cell cycle phases, the expression of proliferation markers, modulators of cell death pathways, and mitochondrial potential. Our results indicate that the IsCT1 derivatives IsCT-P and AC-AFPK-IsCT1 possess cytotoxic properties towards squamous cell carcinoma cells, reducing mitochondrial membrane potential and the proliferative index. The treatment of cancer cells with AC-AFPK-IsCT1 led to a positive modulation of pro-apoptotic markers p53 and caspases 3 and 8, a decrease in PCNA and Cyclin D1 expression, and cell cycle arrest in the S phase. Notably, contrary to the parental IsCT1 peptide, AC-AFPK-IsCT1 did not exhibit hemolytic activity or cytotoxicity towards normal cells. Therefore, AC-AFPK-IsCT1 might be a viable therapeutic option for head and neck cancer treatment.

Psoralidin: emerging biological activities of therapeutic benefits and its potential utility in cervical cancer

Cervical cancer (CaCx) is the fourth most prevalent cancer in women contributing to 341,831 annual deaths globally in 2020. Owing to its high mortality rate, the identification of novel inhibitors preventing CaCx progression is of utmost importance. Recent studies have emphasized the use of phytochemicals for cancer prevention due to their low toxicity. Psoralidin, a bioactive compound extracted from the seeds of the medicinal plant Psoralea corylifolia, showcases the potential for promoting health benefits. A range of studies showing anti-inflammatory, anti-oxidant, estrogenic, neuroprotective, anti-diabetic, anti-depressant, antimicrobial, and anti-tumor activities substantiate its promising biological effects. The anti-tumor potential of psoralidin has been well-documented. Its capacity to effectively target cancer stem cells (CSCs) in general adds to its therapeutic potential. Psoralidin carries out its anti-cancer activity by inducing oxidative stress, autophagy, and apoptosis. This unique characteristic suggests its potential to be used as an adjunct molecule in combination with existing treatment to enhance the efficacy of chemo/radiotherapy for treating CaCx. However, low bioavailability and intestinal efflux limit the use of psoralidin in clinical applications. Therefore, further investigation is needed in area of drug delivery and mechanism of action to fully harness the beneficial effects of psoralidin. The present study examines the current understanding of the molecular properties of this coumestan, as well as its various molecular targets with a particular emphasis on its anti-cancer activity. The study will help in designing effective and novel therapeutic interventions for targeting signaling pathways and other regulators involved in mediating CaCx progression, which will eventually help in effective management of CaCx.

Ultrasonic synthesis, characterization, DFT and molecular docking of a biocompatible Zn-based MOF as a potential antimicrobial, anti-inflammatory and antitumor agent

Zinc metal–organic frameworks have emerged as promising candidates, demonstrating excellent biological properties stemming from the unique characteristics of MOFs and zinc. In this study, we employed a facile method to synthesize a zinc metal–organic framework [Zn(IP)(H2O)] using ultrasound irradiation, with the linker being isophthalic acid (IPA) (1,3-benzene dicarboxylic acid). The parent Zn-MOF and two Ag/Zn-MOF samples prepared via loading and encapsulation methods were comprehensively characterized using various techniques, including FT-IR, XRD, SEM, TEM, N2 adsorption–desorption isotherm, UV–vis spectroscopy and TGA. The parent Zn-MOF and two Ag/Zn-MOF samples exhibited a broad spectrum of antibacterial effects. Remarkably, genomic DNA of P. aeruginosa was effectively degraded by Zn-MOF, further supporting its potent antibacterial results. The free radical inhibition assay demonstrated a 71.0% inhibition under the influence of Zn-MOF. In vitro cytotoxicity activity of Zn-MOF against HepG-2 and Caco-2 cell lines revealed differential cytotoxic effects, with higher cytotoxicity against Caco-2 as explored from the IC50 values. This cytotoxicity was supported by the high binding affinity of Zn-MOF to CT-DNA. Importantly, the non-toxic property of Zn-MOF was confirmed through its lack of cytotoxic effects against normal lung cell (Wi-38). The anti-inflammatory treatment of Zn-MOF achieved 75.0% efficiency relative to the standard Ibuprofen drug. DFT and docking provided insights into the geometric stability of Zn-MOF and its interaction with active amino acids within selected proteins associated with the investigated diseases. Finally, the synthesized Zn-MOF shows promise for applications in cancer treatment, chemoprevention, and particularly antibacterial purposes.

Single-cell RNA sequencing reveals anti-tumor potency of CD56+ NK cells and CD8+ T cells in humanized mice via PD-1 and TIGIT co-targeting

In solid tumors, the exhaustion of natural killer (NK) cells and cytotoxic Tcells in the immunosuppressive tumor microenvironment poses challenges for effective tumor control. Conventional humanized mouse models of hepatocellular carcinoma patient-derived xenografts (HCC-PDX) encounter limitations in NK cell infiltration, hindering studies on NK cell immunobiology. Here, we introduce an improved humanized mouse model with restored NK cell reconstitution and infiltration inHCC-PDX, coupled with single-cell RNA sequencing (scRNA-seq) to identify potential anti-HCC treatments. A single administration of adeno-associated virus carrying human interleukin-15 reinstated persistent NK cell reconstitution and infiltration in HCC-PDX in humanized mice. scRNA-seq revealed NK cell and Tcell subpopulations with heightened PDCD1 and TIGIT levels. Notably, combination therapy with anti-PD-1 and anti-TIGIT antibodies alleviated HCC burden in humanized mice, demonstrating NK cell-dependent efficacy. Bulk-RNA sequencing analysis also revealed significant alterations in the tumor transcriptome that may contribute to further resistance after combination therapy, warranting further investigations. As an emerging strategy, ongoing clinical trials with anti-PD-1 and anti-TIGIT antibodies provide limited data. The improved humanized mouse HCC-PDX model not only sheds light on the pivotal role of NK cells but also serves as a robust platform for evaluating safety and anti-tumor efficacy of combination therapies and other potential regimens, complementing clinical insights.

Anti-tumor potential of high salt in breast Cancer cell lines

Anti-tumor potential of high salt in breast Cancer cell lines

Discovery of 7-(1-methyl-1H-pyrazol-4-yl)-1,6-naphthyridine derivatives as potent inhibitors of rearranged during transfection (RET) and RET solvent-front mutants for overcoming selpercatinib resistance

Rearranged during transfection kinase (RET) inhibition has been considered a promising therapeutic approach for treatment of a variety of cancers. However, the clinical therapeutic benefits of the second-generation RET inhibitor selpercatinib are greatly compromised by acquired resistance mediated by solvent-front mutations (e.g., RETG810 R/S/C). Herein, we report a class of 7-(1-methyl-1H-pyrazol-4-yl)-1,6-naphthyridine derivatives as potent RET and RET solvent-front mutant inhibitors for overcoming selpercatinib resistance. The representative compound 20p exhibited excellent in vitro inhibitory activities against solvent-front mutations (RETG810R, RETG810S, and RETG810C) with low nanomolar range (IC50 of 5.7–8.3 nM), which was 15−29-fold more potent than selpercatinib (IC50 of 95.3–244.1 nM). Additionally, 20p exhibited acceptable pharmacokinetic properties with oral bioavailability of 30.4 %. Importantly, 20p exhibited highly impressive antitumor potency in both a Ba/F3-KIF5B-RETWT-derived xenograft mouse model and a selpercatinib-resistant Ba/F3-KIF5B-RETG810R-positive mutant xenograft mouse model. Overall, 20p represents a novel and promising drug lead for overcoming RET solvent-front mutation-based resistance to selpercatinib.