Colorectal Cancer Xenograft Model Research Articles

Anticancer effects of PEP06 (TB01) in combination with Trifluridine/Tipiracil (TAS-102) in a xenograft model of human colorectal cancer

BackgroundColorectal cancer (CRC) is the third most common cancer globally, with advanced stages presenting significant treatment challenges. Recently years, drug combination therapy has become a promising strategy for cancer treatment.ObjectiveTo evaluate the therapeutic efficacy of the combination of the anti-angiogenic drug PEP06 (TB01) and the cytotoxic drug Trifluridine/Tipiracil (TAS-102) in human CRC HCT-116 xenograft mouse model. And quantitative assessment of the interaction between TB01 and TAS-102 in the treatment based on pharmacological effects.MethodsThis study utilized the human CRC HCT-116 xenograft nude mouse model to evaluate the antitumor effects of TAS-102 and TB01, both as mono-therapies and in combination therapies.ResultsThe combination therapy not only demonstrated significantly inhibited tumor growth in a dose-dependent manner, but also seems to reduce the common toxicity associated with such treatments, as shown by the maintenance of body weights in the treated mice.ConclusionThe synergistic effect observed from the combined use of TAS-102 and TB01 suggests a promising new treatment avenue for refractory CRC patients, meriting further investigation and potential clinical application.

High Carbonyl Graphene Oxide Suppresses Colorectal Cancer Cell Proliferation and Migration by Inducing Ferroptosis via the System Xc-/GSH/GPX4 Axis.

Colorectal cancer (CRC) is characterized by a high rate of both incidence and mortality, and its treatment outcomes are often affected by recurrence and drug resistance. Ferroptosis, an iron-dependent programmed cell death mechanism triggered by lipid peroxidation, has recently gained attention as a potential therapeutic target. Graphene oxide (GO), known for its oxygen-containing functional groups, biocompatibility, and potential for functionalization, holds promise in cancer treatment. However, its role in ferroptosis induction in CRC remains underexplored. The objective of this study was to investigate the effects of High Carbonyl Graphene Oxide (HC-GO) on ferroptosis in CRC and elucidate the underlying mechanisms. In vitro assays were conducted to evaluate the impact of HC-GO on CRC cell proliferation, mitochondrial function, iron accumulation, lipid peroxidation, and reactive oxygen species (ROS) production. The ferroptosis inhibitor Fer-1 was used to confirm the role of ferroptosis in HC-GO's anti-tumor effects. In vivo, the anti-tumor activity of HC-GO was assessed in a CRC xenograft model, with organ toxicity evaluated. HC-GO significantly inhibited CRC cell proliferation, induced mitochondrial damage, and enhanced iron accumulation, lipid peroxidation, and ROS production. It also downregulated the ferroptosis-inhibiting proteins GPX4 and SLC7A11, which were reversed by Fer-1, confirming the involvement of ferroptosis in HC-GO's anti-cancer effects. In vivo, HC-GO significantly suppressed tumor growth without noticeable toxicity to vital organs. HC-GO triggered ferroptosis in CRC cells by suppressing the System Xc-/GSH/GPX4 pathway, providing a novel therapeutic strategy for CRC treatment. These findings suggest HC-GO as a promising nanomedicine for clinical application, warranting further investigation to explore its potential in CRC therapy.

Chlorhexidine Dihydrochloride Shows Anti-tumor Effects in Desmoid Tumors and Colorectal Cancer.

Desmoid tumors (DTs), or aggressive fibromatosis, are rare neoplasms arising from connective tissue, frequently exhibiting local invasiveness. The limited treatment options and high recurrence rates of DTs highlight the need for novel therapeutic strategies. This study investigated the efficacy of chlorhexidine dihydrochloride (CD) in inhibiting the growth of DTs and colorectal cancer (CRC). A mouse model with Apc mutations, specifically Apc1638N/+, was generated to study DTs. DT cells (Apc1638N+) (DTA) were collected from the mice for in vitro experiments. DTA were treated with CD, along with a CRC cell line (HCT-116), and tumor organoids derived from Apc1638N/+ mice. The effects of CD were assessed through cell viability assay (WST assay), colony formation assay, and cell migration assay. We tested the induction of cell apoptosis through caspase 3/7 activity assays and immunoblot analysis of cleaved-caspase 3 and cleaved-PARP1. Additionally, CD was tested for its anti-tumor efficacy using an in vivo CRC xenograft model with the HCT-116 cell line. CD significantly inhibited the viability, migration, and colony formation of DTA and CRC cells. It remarkably decreased the tumor growth in organoids derived from intestinal tumor cells in the Apc1638N/+ mouse model. Furthermore, CD showed anti-tumor effects in an in vivo CRC xenograft model using the HCT-116 cell line. CD represents a promising therapeutic strategy for treating both DTs and CRC.

Anti-tumor Effects of Idarubicin Hydrochloride in Desmoid Tumors.

Desmoid tumors (DTs), also referred to as aggressive fibromatosis, originate from connective tissues and typically manifest with a propensity for local invasion. Despite extensive research efforts aimed at exploring novel anti-tumor agents for DTs, the development of effective clinical management strategies remains an ongoing challenge due to the limited success of current treatments, which frequently lead to inconsistent outcomes and a high recurrence rate of DTs. To overcome these limitations, we focused our research aim on a drug repositioning approach to identify existing medications that could be effective against DTs. Mouse models with Apc mutations, specifically Apc1638N/+ and Apc1638N/+/Trp53-/-, were generated to study DTs. Primary desmoid cells were isolated from these models for experimental analysis. Idarubicin hydrochloride (IDH), a topoisomerase II (TOPO II) inhibitor, was tested on these primary cells, colorectal cancer (CRC) cell lines, and tumor organoids derived from Apc1638N/+ mice. Cell viability was determined with the WST reagent and colony formation assay was evaluated. The anti-tumor efficacy of IDH was tested in an in vivo CRC xenograft model using HCT-116 cells. The TOPO II inhibitor IDH showed significant growth inhibition effects on Apc1638N/+ and Apc1638N/+/Trp53-/- cells. IDH also showed remarkable anti-tumor effects on CRC cell lines and tumor organoids derived from intestinal tumor cells of the Apc1638N/+ mouse model. Furthermore, IDH exerted dramatic anti-tumor effects on an HCT-116 cell line xenograft mouse model. IDH could be a promising therapeutic agent for inhibiting DTs and CRC by targeting TOPO II.

Design, synthesis, and biological evaluation of novel (E)-2-cyano-3-(4,9-dioxo-4,9-dihydronaphtho[2,3-b]furan-2-yl) derivatives as potent STAT3-targeting anticolorectal cancer agents

Dysregulation of signal transducer and activator of transcription 3 (STAT3) is implicated in the pathogenesis of various cancers, underscoring its potential as a cancer therapeutic target. In this work, we designed and synthesized a novel series of (E)-2-cyano-3-(4,9-dioxo-4,9-dihydronaphtho[2,3-b]furan-2-yl) derivatives and evaluated their anti-proliferative effects on tumour cells. Among these derivatives, NW16 exhibited remarkable antiproliferative activity against HCT116 cells, with an IC50 value of 0.28 μM, and exhibited dose- and time-dependent inhibition of the JAK/STAT3 signalling pathway. In addition, NW16 induced reactive oxygen species (ROS) production, which subsequently suppressed the ROS-dependent PI3K/AKT pathway and enhanced its antitumour efficacy. In vivo studies confirmed significant tumour-suppressive effects upon oral administration of NW16 along with favourable tolerability in a colorectal cancer xenograft model. These results indicate that NW16 could be a promising candidate for developing targeted therapy for colorectal cancer because of its multifaceted mechanism.

Macrophage-Derived Exosomes Promoted the Development and Stemness of Inflammatory Bowel Disease-Related Colorectal Cancer via nuclear paraspeckle assembly transcript 1-Mediated miRNA-34a-5p/phosphoprotein enriched in astrocytes 15 Axis.

Inflammatory bowel disease (IBD) is closely associated with the development of colorectal cancer (CRC) due to the chronic inflammatory response. Macrophages play critical roles in regulating the microenvironment to facilitate tumor progression. Exosomes are key modulators for the communication between macrophages and tumor cells. The mechanism of macrophage-derived exosomes in IBD-related CRC development remains unclear. The macrophages were isolated using fluorescence activating cell sorter (FACS). The RNA and protein expressions in exosomes and CRC cells were examined by quantitative real-time polymerase chain reaction and western blot assays, respectively. CRC cell development was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, BrdU staining, Transwell assay, and spheroid formation assay. The level of stemness was determined by detecting the proportion of leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5)-positive CRC cells and the expression of LGR5, CD133, and CD44. Molecular interaction experiments were done using luciferase reporter assay and RNA immunoprecipitation assay. Xenograft tumor model in vivo and immunohistochemistry were used to observe the pathological changes. Macrophage-derived exosomes from IBD-related CRC tissues were enriched with nuclear paraspeckle assembly transcript 1 (NEAT1) and able to promote the progression and stemness of CRC both in vitro and in vivo. The exosomal NEAT1 could sponge miR-34a-5p, leading to the restoration of PEA15 expression in CRC cells and promoting the development of CRC. Inhibition of NEAT1 in exosomes could effectivity inhibit the tumor growth in the CRC xenograft model. These findings provide novel insights into how macrophages affect CRC development and highlight exosomal NEAT1 as a therapeutic target for CRC treatment.

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.

Establishment and Clinical Significance of the Patient-Derived Xenograft Model of Colorectal Cancer.

Patient-derived xenograft (PDX) models are widely acknowledged for their ability to reflect the heterogeneity of humancancers and can be used to improve preclinical models. In this study, we evaluatedthe factors affecting the tumor formation rate ofthe PDX colorectal cancer (CRC)model and conducted preliminary drug sensitivity tests. CRC patients who underwent elective surgery at Shaoxing People's Hospital from November 2019 to October 2020 were included. The tumor tissue obtained from surgery was transplanted to the back of NSG mice, and the PDX model was established and subcultured to the F3 generation. Factors that affected tumorigenicity were analyzed and compared histologically. Drug interventions included 5-fluorouracil, oxaliplatin, and propofol. Sixty CRC patients were included in this study, and tumorigenesis was observed in CRC tissue derived from 37 cases (62%). The primary tumor malignancy degree (tumor stage and degree of cell differentiation), preoperative carcinoembryonic antigen level, and tumor location in CRC patients could affect the tumorigenicity of the PDX model. Histopathological analysis of CRC-PDX transplanted tumor tissue was highly consistent with the patient's tumor tissue. All four chemotherapy regimens could inhibit tumor growth and cause tumor tissue damage. Propofol could inhibit diarrhea in mice and protect intestinal mucosa. The CRC-PDX model established in this study can maintain the biological characteristics of primary tumors and can be used as a reference model for the individualized treatment of CRC patients. The degree of malignancy of the primary tumor is the primary factor affecting the tumorigenesis rate of the PDX model.

In Vitro Amplification of NK Cells from Feeder Layer Cells Expressing IL-21

To investigate the effect of feeder layer cells expressing interleukin (IL)-21 on the amplification of NK cells In Vitro . The K562 cell line with IL-21 expression on its membrane was constructed by electroporation, and co-cultured with NK cells after inactivation. The proliferation of NK cells was observed. The killing function of the amplified NK cells In Vitro was evaluated by the lactate dehydrogenase (LDH) and interferon-γ (IFN-γ) release assay. A colorectal cancer xenograft model in NOD/SCID mice was established, and a blank control group, a NK cell group and an amplified NK cell group were set up to detect the tumor killing effect of amplified NK cells in vivo. K562 cells expressing IL-21 on the membrane were successfully constructed by electroporation. After co-culturing with K562 cells expressing IL-21 on the membrane for 17 days, the NK cells increased to 700 times, which showed an enhanced amplification ability compared with control group (P < 0.001). In the tumor cell killing experiment In Vitro , there was no significant difference in the killing activity on tumor cells between NK cells and amplified NK cells, and there was also no significant difference in mice in vivo. K562 cells expressing IL-21 on the membrane can significantly increase the amplification ability of NK cells In Vitro , but do not affect the killing function of NK cells In Vitro and in vivo. It can be used for the subsequent large-scale production of NK cells In Vitro .

274 (PB262): Development of Patient-Derived Colorectal Cancer Xenograft and Organoid Models with Acquired Resistance to KRAS G12C Inhibitors

274 (PB262): Development of Patient-Derived Colorectal Cancer Xenograft and Organoid Models with Acquired Resistance to KRAS G12C Inhibitors

Impact of Tumoral β2-Adrenergic Receptor Expression on Chemotherapeutic Response and Prognosis in Patients with Advanced Colorectal Cancer.

The β2-adrenergic receptor (β2-AR) is a therapeutic target for circulatory agonists and exhibits oncogenic activity in several cancers. However, its role in advanced colorectal cancer (CRC) treated using chemotherapy remains unclear. We investigated the potential of β2-AR as a novel chemosensitivity marker and therapeutic target in inoperable CRC. β2-AR expression was evaluated immunohistochemically in 80 advanced or recurrent CRC cases for which untreated resected specimens were available before systemic chemotherapy implementation. We assessed the relationship among β2-AR protein expression, clinicopathological factors, therapeutic response, and prognosis. Furthermore, we evaluated the significance of β2-AR as an in vitro and in vivo therapeutic target using CRC cell lines and a CRC xenograft model treated with the β-blocker, propranolol, and other anticancer agents. High tumoral β2-AR expression was associated with shorter progression-free survival and chemotherapeutic resistance in patients treated with oxaliplatin-based regimens and bevacizumab-based regimens. We found no synergistic effect between propranolol and oxaliplatin. However, combined administration of propranolol and bevacizumab induced significant tumor shrinkage in the CRC xenograft model. β2-AR is a possible biomarker for chemosensitivity and prognosis in advanced CRC. Repositioning existing β-blockers could be beneficial for treating CRC resistant to existing treatment regimens.

Structural insights into molecular-targeting helix–loop–helix peptide against vascular endothelial growth factor-A

Mid-sized binding peptides have recently emerged as a new therapeutic modality. A helix-loop-helix (HLH) peptide was designed as a scaffold for combinatorial peptide libraries. We screened the HLH peptide libraries against human vascular endothelial growth factor-A (VEGF) to generate a peptide, VS42-LR3, which inhibited VEGF/receptor interaction and suppressed tumor growth in a murine xenograft model of human colorectal cancer. Here, we report the first crystal structure of the HLH peptide in a complex with VEGF at high resolution using space-grown protein crystals. The X-ray structural analysis revealed that the monomeric VS42-LR3 adopted an HLH structure and bound to VEGF at the VEGF receptor-binding site. Interestingly, from the site-directed mutagenesis, thermodynamic analysis, and molecular dynamic simulations, it turned out that the loop region in the non-interacting surface to VEGF affected the structural rigidity of the whole HLH to increase the binding affinity. These findings provide valuable insights for the design of more structurally stable and higher affinity mid-sized binding peptides as well as HLH peptides, that could play a crucial role in advancing molecular-targeting therapies.

Novel ST1926 Nanoparticle Drug Formulation Enhances Drug Therapeutic Efficiency in Colorectal Cancer Xenografted Mice.

Cancer is a major public health problem that ranks as the second leading cause of death. Anti-cancer drug development presents with various hurdles faced throughout the process. Nanoparticle (NP) formulations have emerged as a promising strategy for enhancing drug delivery efficiency, improving stability, and reducing drug toxicity. Previous studies have shown that the adamantyl retinoid ST1926 displays potent anti-tumor activities in several types of tumors, particularly in colorectal cancer (CRC). However, phase I clinical trials in cancer patients using ST1926 are halted due to its low bioavailability. In this manuscript, we developed ST1926-NPs using flash nanoprecipitation with polystyrene-b-poly (ethyleneoxide) as an amphiphilic stabilizer and cholesterol as a co-stabilizer. Dynamic light scattering revealed that the resulting ST1926-NPs Contin diameter was 97 nm, with a polydispersity index of 0.206. Using cell viability, cell cycle analysis, and cell death assays, we showed that ST1926-NP exhibited potent anti-tumor activities in human CRC HCT116 cells. In a CRC xenograft model, mice treated with ST1926-NP exhibited significantly lowered tumor volumes compared to controls at low drug concentrations and enhanced the delivery of ST1926 to the tumors. These findings highlight the potential of ST1926-NPs in attenuating CRC tumor growth, facilitating its further development in clinical settings.

Radiolabeling and Preclinical Evaluation of Therapeutic Efficacy of 225Ac-ch806 in Glioblastoma and Colorectal Cancer Xenograft Models.

The epidermal growth factor receptor (EGFR) protein is highly expressed in a range of malignancies. Although therapeutic interventions directed toward EGFR have yielded therapeutic responses in cancer patients, side effects are common because of normal-tissue expression of wild-type EGFR. We developed a novel tumor-specific anti-EGFR chimeric antibody ch806 labeled with 225Ac and evaluated its invitro properties and therapeutic efficacy in murine models of glioblastoma and colorectal cancer. Methods: 225Ac-ch806 was prepared using different chelators, yielding [225Ac]Ac-macropa-tzPEG3Sq-ch806 and [225Ac]Ac-DOTA-dhPzPEG4-ch806. Radiochemical yield, purity, apparent specific activity, and serum stability of 225Ac-ch806 were quantified. In vitro cell killing effect was examined. The biodistribution and therapeutic efficacy of 225Ac-ch806 were investigated in mice with U87MG.de2-7 and DiFi tumors. Pharmacodynamic analysis of tumors after therapy was performed, including DNA double-strand break immunofluorescence of γH2AX, as well as immunohistochemistry for proliferation, cell cycle arrest, and apoptosis. Results: [225Ac]Ac-macropa-tzPEG3Sq-ch806 surpassed [225Ac]Ac-DOTA-dhPzPEG4-ch806 in radiochemical yield, purity, apparent specific activity, and serum stability. [225Ac]Ac-macropa-tzPEG3Sq-ch806 was therefore used for both invitro and invivo studies. It displayed a significant, specific, and dose-dependent invitro cell-killing effect in U87MG.de2-7 cells. 225Ac-ch806 also displayed high tumor uptake and minimal uptake in normal tissues. 225Ac-ch806 significantly inhibited tumor growth and prolonged survival in both U87MG.de2-7 and DiFi models. Enhanced γH2AX staining was observed in 225Ac-ch806-treated tumors compared with controls. Reduced Ki-67 expression was evident in all 225Ac-ch806-treated tumors. Increased expression of p21 and cleaved caspase 3 was shown in U87MG.de2-7 and DiFi tumors treated with 225Ac-ch806. Conclusion: In glioblastoma and colorectal tumor models, 225Ac-ch806 significantly inhibited tumor growth via induction of double-strand breaks, thereby constraining cancer cell proliferation while inducing cell cycle arrest and apoptosis. These findings underscore the potential clinical applicability of 225Ac-ch806 as a potential therapy for EGFR-expressing solid tumors.

Redistribution of Defective Mitochondria-mediated Dihydroorotate Dehydrogenase Imparts 5-Fluorouracil Resistance in Colorectal Cancer

Although 5-fluorouracil (5-FU) is the primary chemotherapy treatment for colorectal cancer (CRC), its efficacy is limited by drug resistance. Ferroptosis activation is a promising treatment for 5-FU-resistant cancer cells; however, potential therapeutic targets remain elusive. This study investigated ferroptosis vulnerability and dihydroorotate dehydrogenase (DHODH) activity using stable, 5-FU-resistant CRC cell lines and xenograft models. Ferroptosis was characterized by measuring malondialdehyde levels, assessing lipid metabolism and peroxidation, and using mitochondrial imaging and assays. DHODH function is investigated through gene knockdown experiments, tumor behavior assays, mitochondrial import reactions, intramitochondrial localization, enzymatic activity analyses, and metabolomics assessments. Intracellular lipid accumulation and mitochondrial DHODH deficiency led to lipid peroxidation overload, weakening the defense system of 5-FU-resistant CRC cells against ferroptosis. DHODH, primarily located within the inner mitochondrial membrane, played a crucial role in driving intracellular pyrimidine biosynthesis and was redistributed to the cytosol in 5-FU-resistant CRC cells. Cytosolic DHODH, like its mitochondrial counterpart, exhibited dihydroorotate catalytic activity and participated in pyrimidine biosynthesis. This amplified intracellular pyrimidine pools, thereby impeding the efficacy of 5-FU treatment through molecular competition. These findings contribute to the understanding of 5-FU resistance mechanisms and suggest that ferroptosis and DHODH are promising therapeutic targets for patients with CRC exhibiting resistance to 5-FU.

An Anti-VEGF-B Antibody Reduces Abnormal Tumor Vasculature and Enhances the Effects of Chemotherapy

The vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are key regulators of blood vessel formation, including in tumors, where their deregulated function can promote the production of aberrant, leaky blood vessels, supporting tumor development. Here we investigated the VEGFR1 ligand VEGF-B, which we demonstrate to be expressed in tumor cells and in tumor stroma and vasculature across a range of tumor types. We examined the anti-VEGF-B-specific monoclonal antibody 2H10 in preclinical xenograft models of breast and colorectal cancer, in comparison with the anti-VEGF-A antibody bevacizumab. Similar to bevacizumab, 2H10 therapy was associated with changes in tumor blood vessels and intra-tumoral diffusion consistent with normalization of the tumor vasculature. Accordingly, treatment resulted in partial inhibition of tumor growth, and significantly improved the response to chemotherapy. Our studies indicate the importance of VEGF-B in tumor growth, and the potential of specific anti-VEGF-B treatment to inhibit tumor development, alone or in combination with established chemotherapies.

Exploration of novel isoxazole-fused quinone derivatives as anti-colorectal cancer agents through inhibiting STAT3 and elevating ROS level

Colorectal cancer (CRC) is trending to be a major health problem throughout the world. Therapeutics with dual modes of action have shown latent capacity to create ideal anti-tumor activity. Signal transducer and activator of transcription 3 (STAT3) has been proved to be a potential target for the development of anti-colon cancer drug. In addition, modulation of tumor redox homeostasis through deploying exogenous reactive oxygen species (ROS)-enhancing agents has been widely applied as anti-tumor strategy. Thus, simultaneously targeting STAT3 and modulation ROS balance would offer a fresh avenue to combat CRC. In this work, we designed and synthesized a novel series of isoxazole-fused quinones, which were evaluated for their preliminary anti-proliferative activity against HCT116 cells. Among these quinones, compound 41 exerted excellent in vitro anti-tumor effect against HCT116 cell line with an IC50 value of 10.18 ± 0.4 nM. Compound 41 was proved to bind to STAT3 by using Bio-Layer Interferometry (BLI) assay, and can significantly inhibit phosphorylation of STAT3. It also elevated ROS of HCT116 cells by acting as a substrate of NQO1. Mitochondrial dysfunction, apoptosis, and cell cycle arrest, which was caused by compound 41, might be partially due to the inhibition of STAT3 phosphorylation and ROS production induced by 41. Moreover, it exhibited ideal anti-tumor activity in human colorectal cancer xenograft model and good safety profiles in vivo. Overall, this study provided a novel quinone derivative 41 with excellent anti-tumor activity by inhibiting STAT3 and elevating ROS level, and gave insights into designing novel anti-tumor therapeutics by simultaneously modulation of STAT3 and ROS.

Preclinical evaluation of AGTR1-Targeting molecular probe for colorectal cancer imaging in orthotopic and liver metastasis mouse models

Despite advancements in colorectal cancer (CRC) treatment, the prognosis remains unfavorable for patients with distant liver metastasis. Fluorescence molecular imaging with specific probes is increasingly used to guide CRC surgical resection in real-time and treatment planning. Here, we demonstrate the targeted imaging capacity of an MPA-PEG4-N3-Ang II probe labeled with near-infrared (NIR) fluorescent dye targeting the angiotensin II (Ang II) type 1 receptor (AGTR1) that is significantly upregulated in CRC. MPA-PEG4-N3-Ang II was highly selective and specific to in vitro tumor cells and in vivo tumors in a mouse CRC xenograft model. The favorable ex vivo imaging and in vivo biodistribution of MPA-PEG4-N3-Ang II afforded tumor-specific accumulation with low background and >10 contrast tumor-to-colorectal values in multiple subcutaneous CRC models at 8 h following injection. Biodistribution analysis confirmed the probe's high uptake in HT29 and HCT116 orthotopic and liver metastatic models of CRC with signal-to-noise ratio (SNR) values of tumor-to-colorectal and -liver fluorescence of 5.8 ± 0.6, 5.3 ± 0.7, and 2.7 ± 0.5, 2.6 ± 0.5, respectively, enabling high-contrast intraoperative tumor visualization for surgical navigation. Given its rapid tumor targeting, precise tumor boundary delineation, durable tumor retention and docking study, MPA-PEG4-N3-Ang II is a promising high-contrast imaging agent for the clinical detection of CRC.

The SOS1 Inhibitor MRTX0902 Blocks KRAS Activation and Demonstrates Antitumor Activity in Cancers Dependent on KRAS Nucleotide Loading.

KRAS is the most frequently mutated oncogene in human cancer and facilitates uncontrolled growth through hyperactivation of the receptor tyrosine kinase (RTK)/mitogen-activated protein kinase (MAPK) pathway. The Son of Sevenless homolog 1 (SOS1) protein functions as a guanine nucleotide exchange factor (GEF) for the RAS subfamily of small GTPases and represents a druggable target in the pathway. Using a structure-based drug discovery approach, MRTX0902 was identified as a selective and potent SOS1 inhibitor that disrupts the KRAS:SOS1 protein-protein interaction to prevent SOS1-mediated nucleotide exchange on KRAS and translates into an anti-proliferative effect in cancer cell lines with genetic alterations of the KRAS-MAPK pathway. MRTX0902 augmented the antitumor activity of the KRAS G12C inhibitor adagrasib when dosed in combination in eight out of 12 KRAS G12C-mutant human non-small cell lung cancer and colorectal cancer xenograft models. Pharmacogenomic profiling in preclinical models identified cell cycle genes and the SOS2 homolog as genetic co-dependencies and implicated tumor suppressor genes (NF1 and PTEN) in resistance following combination treatment. Lastly, combined vertical inhibition of RTK/MAPK pathway signaling by MRTX0902 with inhibitors of EGFR or RAF/MEK led to greater downregulation of pathway signaling and improved antitumor responses in KRAS-MAPK pathway-mutant models. These studies demonstrate the potential clinical application of dual inhibition of SOS1 and KRAS G12C and additional SOS1 combination strategies that will aide in the understanding of SOS1 and RTK/MAPK biology in targeted cancer therapy.

Abstract LB199: Condensate modulator sequesters beta-catenin into depot condensates and demonstrates competitive anti-tumor activity in animal models ofcolorectal cancer

Abstract Constitutive activation of beta-catenin is a well-known driver of malignancy. However, traditional drug discovery approaches have proven challenging and largely unsuccessful in identifying therapeutic agents to modulate the function of beta-catenin. Biomolecular condensates have recently been demonstrated to play key roles in regulating most cellular processes and biological pathways by compartmentalizing biomolecules in membranelles organelles, thus lending novel opportunities to drug previously “undruggable” targets. Here, we leverage condensate biology to discover small molecules that reverse the hyperactive function of beta-catenin in colorectal cancer by entrapping it into depot condensates. We developed a high-throughput phenotypic assay that identifies beta-catenin condensate-modifying compounds (c-mods). Through condensate screening and functional secondary assays, we have identified c-mods that sequester beta-catenin into depots, induce selective cancer cell killing, and reverse oncogenic beta-catenin specific gene expression programs. C-mods identified in our screen are effective in genetically diverse colorectal cancers and a range of Wnt-associated cancers, providing the opportunity to treat a broad patient population. Furthermore, oral dosing of lead c-mod demonstrates competitive tumor growth inhibition as a single agent in xenograft and PDX models of colorectal cancer. Taken together, these results highlight the promise of condensate biology in drugging previously intractable high-value targets in oncology and developing novel treatments for patients suffering from diseases of high unmet need. Citation Format: Costa Salojin, Douglas Baumann, Adam Talbot, Kip West, Thomas Durand-Reville, Isaac Klein, Ann Boija. Condensate modulator sequesters beta-catenin into depot condensates and demonstrates competitive anti-tumor activity in animal models ofcolorectal cancer [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 LB199.