Extra-domain B of fibronectin as an alternative target for drug delivery and a cancer diagnostic and prognostic biomarker for malignant glioma

The Tumor Stroma of Squamous Cell Carcinoma: A Complex Environment That Fuels Cancer Progression

The tumor microenvironment (TME), a complex assembly of cellular and extracellular matrix (ECM) components, plays a crucial role in driving tumor progression, shaping treatment responses, and influencing metastasis. This narrative review focuses on the cutaneous squamous cell carcinoma (cSCC) tumor stroma, highlighting its key constituents and their dynamic contributions. We examine how significant changes within the cSCC ECM-specifically, alterations in fibronectin, hyaluronic acid, laminins, proteoglycans, and collagens-promote cancer progression, metastasis, and drug resistance. The cellular composition of the cSCC TME is also explored, detailing the intricate interplay of cancer-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), endothelial cells, pericytes, adipocytes, and various immune cell populations. These diverse players modulate tumor development, angiogenesis, and immune responses. Finally, we emphasize the TME's potential as a therapeutic target. Emerging strategies discussed in this review include harnessing the immune system (adoptive cell transfer, checkpoint blockade), hindering tumor angiogenesis, disrupting CAF activity, and manipulating ECM components. These approaches underscore the vital role that deciphering TME interactions plays in advancing cSCC therapy. Further research illuminating these complex relationships will uncover new avenues for developing more effective treatments for cSCC.

Nanoparticles traversing the extracellular matrix induce biophysical perturbation of fibronectin depicted by surface chemistry

While the filtering and accumulation effects of the extracellular matrix (ECM) on nanoparticles (NPs) have been experimentally observed, the detailed interactions between NPs and specific biomolecules within the ECM remain poorly understood and pose challenges for in vivo molecular-level investigations. Herein, we adopt molecular dynamics simulations to elucidate the impacts of methyl-, hydroxy-, amine-, and carboxyl-modified gold NPs on the cell-binding domains of fibronectin (Fn), an indispensable component of the ECM for cell attachment and signaling. Simulation results show that NPs can specifically bind to distinct Fn domains, and the strength of these interactions depends on the physicochemical properties of NPs. NP-NH3+ exhibits the highest affinity to domains rich in acidic residues, leading to strong electrostatic interactions that induce severe deformation, potentially disrupting the normal functioning of Fn. NP-CH3 and NP-COO- selectively occupy the RGD/PHSRN motifs, which may hinder their recognition by integrins on the cell surface. Additionally, NPs can disrupt the dimerization of Fn through competing for residues at the dimer interface or by diminishing the shape complementarity between dimerized proteins. The mechanical stretching of Fn, crucial for ECM fibrillogenesis, is suppressed by NPs due to their local rigidifying effect. These results provide valuable molecular-level insights into the impacts of various NPs on the ECM, holding significant implications for advancing nanomedicine and nanosafety evaluation.

Assessment of the Efficacy of the Combination of RNAi of lncRNA DANCR with Chemotherapy to Treat Triple Negative Breast Cancer Using Magnetic Resonance Molecular Imaging

Long noncoding RNA (lncRNA) differentiation antagonizing noncoding RNA (DANCR) is overexpressed in human triple-negative breast cancer (TNBC) and promotes cell migration and proliferation. TNBC is limited in treatment options relative to hormone-receptor-positive breast cancer and is commonly treated with chemotherapy, which is often compromised by acquired resistance. DANCR has been implicated in the development of chemoresistance across multiple cancer types. Here, we applied magnetic resonance molecular imaging (MRMI) with a targeted contrast agent, MT218, specific to extradomain-B fibronectin (EDB-FN), a marker for epithelial-to-mesenchymal transition, to assess the therapeutic efficacy of the combination of paclitaxel and ZD2-PEG-ECO/siDANCR nanoparticles (ZD2-siDANCR-ELNP) to treat TNBC. The treatment of orthotopic MDA-MB-231 TNBC in mice with paclitaxel significantly suppressed tumor growth but with a significant increase of EDB-FN in the tumor, as revealed by MRMI and immunohistochemistry. Combining ZD2-siDANCR-ELNP with paclitaxel further reduced tumor sizes, along with reduced EDB-FN expression. Interestingly, MT218-MRMI revealed a lower reduction of tumor signal enhancement with the combination treatment than that with the siDANCR treatment alone, which was supported by higher cell density in the tumors treated with the combination therapy, as shown by histochemical analysis. MT218-MRMI clearly revealed the changes of the tumor microenvironment in response to various therapies and is effective to noninvasively assess the response of TNBC tumors to the therapies. Regulating oncogenic lncRNA DANCR is an effective strategy for improving the outcomes of chemotherapy in TNBC.

Pharmacokinetics and Tolerability of the Cancer-Targeting MRI Contrast Agent MT218 in Healthy Males

OBJECTIVE

The aim of this study was to evaluate the pharmacokinetics and safety profile of MT218, a peptide-targeted gadolinium-based contrast agent, in healthy males.

MATERIALS AND METHODS

This was a double-blind, randomized, placebo-controlled, single-ascending-dose study including 30 healthy male subjects. In each dose group (0.01, 0.02, 0.04, and 0.08 mmol/kg), 4 subjects received MT218 and 2 subjects received placebo (saline) in bolus injections. The highest dose group (0.08 mmol/kg) was assessed in 2 cohorts, 1 fasted and 1 nonfasted. Clinical laboratory tests, vital signs, and electrocardiograms were investigated. Gadolinium concentrations were measured in plasma samples collected before administration and over a 24-hour period postinjection, and in urine specimens collected until 22 days. A noncompartmental model was used for pharmacokinetic analysis. A clinical and biological safety follow-up was carried out for up to 6 months.

RESULTS

No clinically significant modifications in biochemistry, hematology, urinalysis, electrocardiogram parameters, or vital signs were reported at any time point for any treatment group. No serious adverse events were observed in any dose group. Transient dizziness, hyperhidrosis, and injection site coldness were the main adverse events reported in both the MT218 and placebo groups. The mean total apparent clearance decreased slightly with increasing dose, and the median plasma t 1/2 ranged from 1.7 hours in the 0.01 mmol/kg group to 2.7 hours in the 0.08 mmol/kg nonfasted group. MT218 was rapidly excreted via renal filtration with 42.9% to 52.8% of the injected dose measured in urine within the first hour after administration, and 92.5% to 117.3% in urine within 24 hours. No Gd was detected by inductively coupled plasma mass spectrometry in urine after 21 days.

CONCLUSION

Single intravenous administration of MT218 was safely tolerated in the healthy males. Its pharmacokinetic parameters and safety profile are well aligned with those of other gadolinium-based contrast agents.

Improving the Efficacy of Common Cancer Treatments via Targeted Therapeutics towards the Tumour and Its Microenvironment

Cancer is defined as the uncontrolled proliferation of heterogeneous cell cultures in the body that develop abnormalities and mutations, leading to their resistance to many forms of treatment. Left untreated, these abnormal cell growths can lead to detrimental and even fatal complications for patients. Radiation therapy is involved in around 50% of cancer treatment workflows; however, it presents significant recurrence rates and normal tissue toxicity, given the inevitable deposition of the dose to the surrounding healthy tissue. Chemotherapy is another treatment modality with excessive normal tissue toxicity that significantly affects patients' quality of life. To improve the therapeutic efficacy of radiotherapy and chemotherapy, multiple conjunctive modalities have been proposed, which include the targeting of components of the tumour microenvironment inhibiting tumour spread and anti-therapeutic pathways, increasing the oxygen content within the tumour to revert the hypoxic nature of the malignancy, improving the local dose deposition with metal nanoparticles, and the restriction of the cell cycle within radiosensitive phases. The tumour microenvironment is largely responsible for inhibiting nanoparticle capture within the tumour itself and improving resistance to various forms of cancer therapy. In this review, we discuss the current literature surrounding the administration of molecular and nanoparticle therapeutics, their pharmacokinetics, and contrasting mechanisms of action. The review aims to demonstrate the advancements in the field of conjugated nanomaterials and radiotherapeutics targeting, inhibiting, or bypassing the tumour microenvironment to promote further research that can improve treatment outcomes and toxicity rates.

CAR-T Therapy Targets Extra Domain B of Fibronectin Positive Solid Tumor Cells

BACKGROUND

CAR-T cell immunotherapy has achieved remarkable success in malignant B-cell malignancies, but progress in solid tumors is slow, and one of the key reasons is the lack of ideal targets. Cancer-specific extra domain B of fibronectin (EDB-FN) is widely upregulated in solid tumors and expressed at low levels in normal tissues. Many imaging and targeted cancer therapies based on EDB-FN targets have been developed and tested in clinical trials, making EDB-FN an ideal target for immunotherapy.

METHODS

We constructed two EDB-FN-targeted CAR-Ts based on the peptide APT0 and the single-chain antibody CGS2 in a lentiviral infection manner for the first time. Luciferase cytotoxicity assay to assess CAR-T killing of tumor cells. An enzyme-linked immunosorbent assay was used to detect the release of the cytokine IFN-γ. Fluorescence imaging to evaluate the dynamics of CAR-T cell and tumor cell coculture. Knockdown assays were used to validate the target specificity of CAR-T cells.

RESULTS

In this research, two CAR-Ts targeting EDB-FN, APT0 CAR-T, and CGS2 CAR-T, were constructed. In vitro, both CAR-T cells produced broad-spectrum killing of multiple EDB-FN-positive solid tumor cell lines and were accompanied by cytokine IFN-γ release. Regarding safety, the two CAR-T cells did not affect T cells' normal growth and proliferation and were not toxic to HEK-293T human embryonic kidney epithelial cells.

CONCLUSION

APT0 CAR-T and CGS2 CAR-T cells are two new CAR-Ts targeting EDB-FN. Both CAR-T cells can successfully identify and specifically kill various EDB-FN-positive solid tumor cells with potential clinical applications.

Treating solid tumors with TCR-based chimeric antigen receptor targeting extra domain B-containing fibronectin

BACKGROUND

The suppression of chimeric antigen receptor (CAR) T cells by the tumor microenvironment (TME) is a crucial obstacle in the T-cell-based treatment of solid tumors. Extra domain B (EDB)-fibronectin is an oncofetal antigen expressed on the endothelium layer of the neovasculature and cancer cells. Though recognized as a T cell therapy target, engineered CAR T cells thus far have failed to demonstrate satisfactory in vivo efficacy. In this study, we report that targeting EDB-fibronectin by redirected TCR-CAR T cells (rTCR-CAR) bypasses the suppressive TME for solid tumor treatment and sufficiently suppressed tumor growth.We generated EDB-targeting CAR by fusing single-chain variable fragment to CD3ε, resulting in rTCR-CAR. Human primary T cells and Jurkat cells were used to study the EDB-targeting T cells. Differences to the traditional second-generation CAR T cell in signaling, immune synapse formation, and T cell exhaustion were characterized. Cytotoxicity of the rTCR-CAR T cells was tested in vitro, and therapeutic efficacies were demonstrated using xenograft models.

METHODS

RESULTS: In the xenograft models, the rTCR-CAR T cells demonstrated in vivo efficacies superior to that based on traditional CAR design. A significant reduction in tumor vessel density was observed alongside tumor growth inhibition, extending even to tumor models established with EDB-negative cancer cells. The rTCR-CAR bound to immobilized EDB, and the binding led to immune synapse structures superior to that formed by second-generation CARs. By a mechanism similar to that for the conventional TCR complex, EDB-fibronectin activated the rTCR-CAR, resulting in rTCR-CAR T cells with low basal activation levels and increased in vivo expansion.

CONCLUSION

Our study has demonstrated the potential of rTCR-CAR T cells targeting the EDB-fibronectin as an anticancer therapeutic. Engineered to possess antiangiogenic and cytotoxic activities, the rTCR-CAR T cells showed therapeutic efficacies not impacted by the suppressive TMEs. These combined characteristics of a single therapeutic agent point to its potential to achieve sustained control of solid tumors.

Shielding and nurturing: Fibronectin as a modulator of cancer drug resistance

Resistance to chemotherapy and targeted therapies constitute a common hallmark of most cancers and represent a dominant factor fostering tumor relapse and metastasis. Fibronectin, an abundant extracellular matrix glycoprotein, has long been proposed to play an important role in the pathobiology of cancer. Recent research has unraveled the role of Fibronectin in the onset of chemoresistance against a variety of antineoplastic drugs including DNA-damaging agents, hormone receptor antagonists, tyrosine kinase inhibitors, microtubule destabilizing agents, etc. The current review summarizes the role played by Fibronectin in mediating drug resistance against diverse anticancer drugs. We have also discussed how the aberrant expression of Fibronectin drives the oncogenic signaling pathways ultimately leading to drug resistance through the inhibition of apoptosis, promotion of cancer cell growth and proliferation.

A sensitive LC-MS/MS assay to quantitate free payload Aur0101 from ADC PYX-201 in rat and monkey plasma

Aim: Aur0101 is a cytotoxic and small-molecule microtubule depolymerizing agent, and is the payload conjugated to antibody-drug conjugate PYX-201. Developing and validating a sensitive bioanalytical method to quantitate Aur0101 was novel and crucial in preclinical PYX-201 studies. Materials & methods: Reference standard Aur0101 and its stable isotope labelled internal standard Aur0101-d8 were used in this LC-MS/MS method. Results: This sensitive assay was validated at a lower limit of quantitation of 15 pg/ml and successfully applied to support preclinical rat and monkey toxicology studies. Preclinical plasma toxicokinetic parameters were presented. Conclusion: A sensitive and robust LC-MS/MS assay was validated for Aur0101 in rat and monkey plasma.

Systematic Review of Molecular Targeted Therapies for Adult-Type Diffuse Glioma: An Analysis of Clinical and Laboratory Studies

Gliomas are the most common brain tumor in adults, and molecularly targeted therapies to treat gliomas are becoming a frequent topic of investigation. The current state of molecular targeted therapy research for adult-type diffuse gliomas has yet to be characterized, particularly following the 2021 WHO guideline changes for classifying gliomas using molecular subtypes. This systematic review sought to characterize the current state of molecular target therapy research for adult-type diffuse glioma to better inform scientific progress and guide next steps in this field of study. A systematic review was conducted in accordance with PRISMA guidelines. Studies meeting inclusion criteria were queried for study design, subject (patients, human cell lines, mice, etc.), type of tumor studied, molecular target, respective molecular pathway, and details pertaining to the molecular targeted therapy-namely the modality, dose, and duration of treatment. A total of 350 studies met the inclusion criteria. A total of 52 of these were clinical studies, 190 were laboratory studies investigating existing molecular therapies, and 108 were laboratory studies investigating new molecular targets. Further, a total of 119 ongoing clinical trials are also underway, per a detailed query on clinicaltrials.gov. GBM was the predominant tumor studied in both ongoing and published clinical studies as well as in laboratory analyses. A few studies mentioned IDH-mutant astrocytomas or oligodendrogliomas. The most common molecular targets in published clinical studies and clinical trials were protein kinase pathways, followed by microenvironmental targets, immunotherapy, and cell cycle/apoptosis pathways. The most common molecular targets in laboratory studies were also protein kinase pathways; however, cell cycle/apoptosis pathways were the next most frequent target, followed by microenvironmental targets, then immunotherapy pathways, with the wnt/β-catenin pathway arising in the cohort of novel targets. In this systematic review, we examined the current evidence on molecular targeted therapy for adult-type diffuse glioma and discussed its implications for clinical practice and future research. Ultimately, published research falls broadly into three categories-clinical studies, laboratory testing of existing therapies, and laboratory identification of novel targets-and heavily centers on GBM rather than IDH-mutant astrocytoma or oligodendroglioma. Ongoing clinical trials are numerous in this area of research as well and follow a similar pattern in tumor type and targeted pathways as published clinical studies. The most common molecular targets in all study types were protein kinase pathways. Microenvironmental targets were more numerous in clinical studies, whereas cell cycle/apoptosis were more numerous in laboratory studies. Immunotherapy pathways are on the rise in all study types, and the wnt/β-catenin pathway is increasingly identified as a novel target.

A sensitive and rapid LC-MS/MS assay for quantitation of free payload Aur0101 from antibody drug conjugate (ADC) PYX-201 in human plasma

PYX-201 is an investigational antibody drug conjugate (ADC) with an engineered, fully human IgG1 antibody, a cleavable chemical linker, and a toxin (Aur0101) with an average drug-antibody ratio (DAR) of ∼ 4. A sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and fully validated to determine the presence in human plasma, of free payload Aur0101 from PYX-201 to assess drug safety and efficacy. Aur0101 and its deuterated internal standard (IS), Aur0101_d₈, were extracted from 25 µL of human plasma using a solid liquid extraction (SLE) method. Chromatographic analysis was carried out on a Waters Acquity UPLC BEH C18 (2.1 mm × 50 mm, 1.7 µm, 130 A) column. Quantitation of free Aur0101 was conducted on a Sciex triple quadrupole mass spectrometer API 6500 + using multiple reaction monitoring (MRM) mode via positive electrospray ionization. The calibration curve was linear over the concentration range of 25.0 to 12,500 pg/mL with correlation coefficient, r² ≥ 0.9988. The intra-assay %RE was between -4.3% to 14.3% with % CV was ≤ 6.2%. The inter-assay %RE was between -0.2% to 9.5% with % CV was ≤ 6.1%. The average analyte recovery was 89.7% and the average IS recovery was 88.7%. Aur0101 was found to be stable in human plasma and human whole blood under various tested conditions with and without the presence of PYX-201. To our knowledge, this is the first published fully validated assay for free, unconjugated Aur0101 in any matrix, from any species. This assay has been successfully applied to clinical sample analysis to support clinical studies.

EDB-FN targeted probes for the surgical navigation, radionuclide imaging, and therapy of thyroid cancer

PURPOSE

Extradomain B of fibronectin (EDB-FN) is a promising diagnostic and therapeutic biomarker for thyroid cancer (TC). Here, we identified a high-affinity EDB-FN targeted peptide named EDBp (AVRTSAD) and developed three EDBp-based probes, Cy5-PEG4-EDBp(Cy5-EDBp), [18F]-NOTA-PEG4-EDBp([18F]-EDBp), and [177Lu]-DOTA-PEG4-EDBp ([177Lu]-EDBp), for the surgical navigation, radionuclide imaging, and therapy of TC.

METHODS

Based on the previously identified EDB-FN targeted peptide ZD2, the optimized EDB-FN targeted peptide EDBp was identified by using the alanine scan strategy. Three EDBp-based probes, Cy5-EDBp, [18F]-EDBp, and [177Lu]-EDBp, were developed for fluorescence imaging, positron emission tomography (PET) imaging, and radiotherapy in TC tumor-bearing mice, respectively. Additionally, [18F]-EDBp was evaluated in two TC patients.

RESULTS

The binding affinity of EDBp to the EDB fragment protein (Kd = 14.4 ± 1.4 nM, n = 3) was approximately 336-fold greater than that of the ZD2 (Kd = 4839.7 ± 361.7 nM, n = 3). Fluorescence imaging with Cy5-EDBp facilitated the complete removal of TC tumors. [18F]-EDBp PET imaging clearly delineated TC tumors, with high tumor uptake (16.43 ± 1.008%ID/g, n = 6, at 1-h postinjection). Radiotherapy with [177Lu]-EDBp inhibited tumor growth and prolonged survival in TC tumor-bearing mice (survival time of different treatment groups: saline vs. EDBp vs. ABRAXANE vs. [177Lu]-EDBp = 8.00 d vs. 8.00 d vs. 11.67 d vs. 22.33 d, ***p < 0.001). Importantly, the first-in-human evaluation of [18F]-EDBp demonstrated that it had specific targeting properties (SUVmax value of 3.6) and safety.

CONCLUSION

Cy5-EDBp, [18F]-EDBp, and [177Lu]-EDBp are promising candidates for the surgical navigation, radionuclide imaging, and radionuclide therapy of TC, respectively.

Extracellular matrix remodeling in tumor progression and immune escape: from mechanisms to treatments

The malignant tumor is a multi-etiological, systemic and complex disease characterized by uncontrolled cell proliferation and distant metastasis. Anticancer treatments including adjuvant therapies and targeted therapies are effective in eliminating cancer cells but in a limited number of patients. Increasing evidence suggests that the extracellular matrix (ECM) plays an important role in tumor development through changes in macromolecule components, degradation enzymes and stiffness. These variations are under the control of cellular components in tumor tissue via the aberrant activation of signaling pathways, the interaction of the ECM components to multiple surface receptors, and mechanical impact. Additionally, the ECM shaped by cancer regulates immune cells which results in an immune suppressive microenvironment and hinders the efficacy of immunotherapies. Thus, the ECM acts as a barrier to protect cancer from treatments and supports tumor progression. Nevertheless, the profound regulatory network of the ECM remodeling hampers the design of individualized antitumor treatment. Here, we elaborate on the composition of the malignant ECM, and discuss the specific mechanisms of the ECM remodeling. Precisely, we highlight the impact of the ECM remodeling on tumor development, including proliferation, anoikis, metastasis, angiogenesis, lymphangiogenesis, and immune escape. Finally, we emphasize ECM "normalization" as a potential strategy for anti-malignant treatment.

Quantification of antibody-drug conjugate PYX-201 in rat and monkey plasma via ELISA and its application in preclinical studies

Aim: PYX-201 is a novel antibody-drug conjugate targeting the extra domain B splice variant of fibronectin in the tumor microenvironment. Accurate quantification of PYX-201 is critical for PYX-201 pharmacokinetics profiling in preclinical studies. Materials & methods: ELISA was performed using reference standard PYX-201, mouse monoclonal anti-monomethyl auristatin E antibody, mouse IgG1, mouse monoclonal anti-human IgG horseradish peroxidase and donkey anti-human IgG horseradish peroxidase. Results: This assay was validated at 50.0-10,000 ng/ml in rat dipotassium EDTA plasma and 250-10,000 ng/ml in monkey dipotassium EDTA plasma. Conclusion: This is the first time for a PYX-201 bioanalytical assay in any matrix to be reported.

CAR-T-Cell Therapy for Solid Tumors Positive for Fibronectin Extra Domain B

(1) Background: The lack of specific targets has slowed the progress of CAR-T in treating solid tumors. Recent studies have revealed that EDB-FN (fibronectin extra domain B) may be an effective target for CAR-T treatment of solid tumors; EDB-FN is expressed in tumor and embryonic tissues, and antibody–cytokine fusion proteins targeting EDB-FN have been developed. However, the therapeutic effects of BBz CAR-engineered T-cells targeting EDB-FN in solid tumors have not been evaluated. (2) Results: In this study, we constructed a BBz CAR construct targeting EDB-FN, and the CAR molecule was expressed on the surface of T-cells by lentiviral transduction. In vitro, CAR-T-cells can be activated to express perforin and granzyme and lyse EDB-positive cells (U-87 MG cells, A549 cells, and HUVECs) and have no toxicity to EDB-negative cells (MCF-7). Compared to T-cells, CAR-T-cells can release cytokines after coculture with EDB-positive cell lines. In vivo, CAR-T-cells inhibited the progression of U-87 MG subcutaneous tumors and significantly reduced the blood vessel density in tumor tissue compared to T-cells, without obvious toxicity to mouse tissues and organs. Furthermore, CAR-T-cells overexpressing BiTE targeting EDB-FN can significantly improve their antitumor activity in vitro. (3) Conclusions: These results demonstrate that CAR-T-cells have specific antitumor and angiogenic activities in vivo and in vitro, suggesting that EDB-FN may be a potential solid tumor target for CAR-T therapy.

Identification of Prognostic Genes in Gliomas Based on Increased Microenvironment Stiffness

With a median survival time of 15 months, glioblastoma multiforme is one of the most aggressive primary brain cancers. The crucial roles played by the extracellular matrix (ECM) stiffness in glioma progression and treatment resistance have been reported in numerous studies. However, the association between ECM-stiffness-regulated genes and the prognosis of glioma patients remains to be explored. Thus, using bioinformatics analysis, we first identified 180 stiffness-dependent genes from an RNA-Seq dataset, and then evaluated their prognosis in The Cancer Genome Atlas (TCGA) glioma dataset. Our results showed that 11 stiffness-dependent genes common between low- and high-grade gliomas were prognostic. After validation using the Chinese Glioma Genome Atlas (CGGA) database, we further identified four stiffness-dependent prognostic genes: FN1, ITGA5, OSMR, and NGFR. In addition to high-grade glioma, overexpression of the four-gene signature also showed poor prognosis in low-grade glioma patients. Moreover, our analysis confirmed that the expression levels of stiffness-dependent prognostic genes in high-grade glioma were significantly higher than in low-grade glioma, suggesting that these genes were associated with glioma progression. Based on a pathophysiology-inspired approach, our findings illuminate the link between ECM stiffness and the prognosis of glioma patients and suggest a signature of four stiffness-dependent genes as potential therapeutic targets.

In Vitro Human Cancer Models for Biomedical Applications

Simple Summary

Cancer is a leading cause of death worldwide. While numerous studies have been conducted on cancer treatment, clinical treatment options for cancers are still limited. To date, animal cancer models for cancer therapeutic studies have faced multiple challenges, including inaccuracy in the representation of human cancers, high cost and ethical concerns. Therefore, lab-grown human cancer models are being developed quickly to fulfill the increasing demand for more relevant models in order to improve knowledge of human cancers and to find novel treatments. This review summarizes the development of lab-grown human cancer models for biomedical applications, including cancer therapeutic development, assessment of human tumor biology and discovery of key cancer markers.

Abstract

Cancer is one of the leading causes of death worldwide, and its incidence is steadily increasing. Although years of research have been conducted on cancer treatment, clinical treatment options for cancers are still limited. Animal cancer models have been widely used for studies of cancer therapeutics, but these models have been associated with many concerns, including inaccuracy in the representation of human cancers, high cost and ethical issues. Therefore, in vitro human cancer models are being developed quickly to fulfill the increasing demand for more relevant models in order to get a better knowledge of human cancers and to find novel treatments. This review summarizes the development of in vitro human cancer models for biomedical applications. We first review the latest development in the field by detailing various types of in vitro human cancer models, including transwell-based models, tumor spheroids, microfluidic tumor-microvascular systems and scaffold-based models. The advantages and limitations of each model, as well as their biomedical applications, are summarized, including therapeutic development, assessment of tumor cell migration, metastasis and invasion and discovery of key cancer markers. Finally, the existing challenges and future perspectives are briefly discussed.

Nanomedicine for brain cancer

CNS tumors remain among the deadliest forms of cancer, resisting conventional and new treatment approaches, with mortality rates staying practically unchanged over the past 30 years. One of the primary hurdles for treating these cancers is delivering drugs to the brain tumor site in therapeutic concentration, evading the blood-brain (tumor) barrier (BBB/BBTB). Supramolecular nanomedicines (NMs) are increasingly demonstrating noteworthy prospects for addressing these challenges utilizing their unique characteristics, such as improving the bioavailability of the payloadsviacontrolled pharmacokinetics and pharmacodynamics, BBB/BBTB crossing functions, superior distribution in the brain tumor site, and tumor-specific drug activation profiles. Here, we review NM-based brain tumor targeting approaches to demonstrate their applicability and translation potential from different perspectives. To this end, we provide a general overview of brain tumor and their treatments, the incidence of the BBB and BBTB, and their role on NM targeting, as well as the potential of NMs for promoting superior therapeutic effects. Additionally, we discuss critical issues of NMs and their clinical trials, aiming to bolster the potential clinical applications of NMs in treating these life-threatening diseases.

Homing Peptide-Based Targeting of Tenascin-C and Fibronectin in Endometriosis

The current diagnostic and therapeutic strategies for endometriosis are limited. Although endometriosis is a benign condition, some of its traits, such as increased cell invasion, migration, tissue inflammation, and angiogenesis are similar to cancer. Here we explored the application of homing peptides for precision delivery of diagnostic and therapeutic compounds to endometriotic lesions. First, we audited a panel of peptide phages for the binding to the cultured immortalized endometriotic epithelial 12Z and eutopic stromal HESC cell lines. The bacteriophages displaying PL1 peptide that engages with angiogenic extracellular matrix overexpressed in solid tumors showed the strongest binding to both cell lines. The receptors of PL1 peptide, tenascin C domain C (TNC-C) and fibronectin Extra Domain-B (Fn-EDB), were expressed in both cells. Silver nanoparticles functionalized with synthetic PL1 peptide showed specific internalization in 12Z and HESC cells. Treatment with PL1-nanoparticles loaded with the potent antimitotic drug monomethyl auristatin E decreased the viability of endometriotic cells in 2D and 3D cultures. Finally, PL1-nanoparticless bound to the cryosections of clinical peritoneal endometriotic lesions in the areas positive for TNC-C and Fn-EDB immunoreactivities and not to sections of normal endometrium. Our findings suggest potential applications for PL1-guided nanoparticles in precision diagnosis and therapy of endometriosis.

Magnetic resonance molecular imaging of extradomain B fibronectin enables detection of pancreatic ductal adenocarcinoma metastasis

Extradomain-B Fibronectin (EDB-FN) is an oncomarker that can be visualized with magnetic resonance molecular imaging (MRMI) to detect pancreatic ductal adenocarcinoma (PDAC) metastasis. In this study, we sought to assess the expression of EDB-FN in clinical samples of PDAC and to evaluate MRMI of PDAC metastasis with an EDB-FN-specific gadolinium-based contrast agent (MT218) in an orthotopic KPC-GFP-Luc mouse model. EDB-FN expression was evaluated in PDAC tissue samples through immunohistochemistry. RNA-Seq data obtained from the GEPIA2 project was evaluated to demonstrate EDB-FN expression in large patient cohorts. FLASH-3D MRI at 3 T of the KPC-GFP-Luc metastasis model was performed following injection of MT218. Tumor enhancement in MR images was correlated to postmortem distribution of KPC-GFP-Luc tumors using fluorescent and bright-field cryo-imaging and anatomical landmarks. EDB-FN immunohistochemical staining scores of human metastatic tumor stroma, (2.17 ± 0.271), metastatic tumor parenchyma (2.08 ± 0.229), primary tumor stroma (1.61 ± 0.26), and primary tumor parenchyma (1.61 ± 0.12) were significantly (p < 0.0001) higher than normal pancreas stroma (0.14 ± 0.10) and normal pancreas parenchyma (0.14 ± 0.14). EDB-FN mRNA expression in tumors is 4.98 log₂(TPM + 1) and 0.18 log₂(TPM + 1) in normal tissue (p < 0.01). A mouse model of EDB-FN rich PDAC metastasis exhibited T₁-weighted contrast to noise (CNR) changes of 21.80 ± 4.34 in perimetastatic regions and 8.38 ± 0.79 in metastatic regions identified through cryo-imaging, significantly higher (p < 0.05) than CNR changes found in normal liver (-6.43 ± 0.92), mesentery (2.24 ± 0.92), spleen (-3.06 ± 2.38) and intestine (1.08 ± 2.15). We conclude that EDB-FN is overexpressed in metastatic and primary PDAC tumors and MRMI with MT218 enables the detection of metastatic and perimetastatic tissues.

Biomedical Applications of a Novel Class of High-Affinity Peptides

Most therapeutic peptides available on the market today are naturally occurring hormones or protein fragments that were serendipitously discovered to possess therapeutic effects. However, the limited repertoire of available natural resources presents difficulties for the development of new peptide drug candidates. Traditional peptides possess several shortcomings that must be addressed for biomedical applications, including relatively low affinity or specificity toward biological targets compared to antibody- and protein scaffold-based affinity molecules, poor in vivo stability owing to rapid enzymatic degradation, and rapid clearance from circulation owing to their small size. Going forward, it will be increasingly important for scientists to develop novel classes of high-affinity and -specificity peptides against desired targets that mitigate these limitations while remaining compatible with pharmaceutical manufacturing processes. Recently, several highly constrained, artificial cyclic peptides have emerged as platforms capable of generating high-affinity peptide binders against various disease-associated protein targets by combining with phage or mRNA display method, some of which have entered clinical trials. In contrast, although linear peptides are relatively easy to synthesize cost-effectively and modify site-specifically at either N- or C-termini compared to cyclic peptides, there have been few linear peptide-based platforms that can provide high-affinity and -specificity peptide binders.In this Account, we describe the creation and development of a novel class of high-affinity peptides, termed "aptide"-from the Latin word "aptus" meaning "to fit" and "peptide"-and summarize their biomedical applications. In the first part, we consider the design and creation of aptides, with a focus on their unique structural features and binding mode, and address screening and identification of target protein-specific aptides. We also discuss advantages of the aptide platform over ordinary linear peptides lacking preorganized structures in terms of the affinity and specificity of identified peptide binders against target molecules. In the second part, we describe the potential biomedical applications of various target-specific aptides, ranging from imaging and therapy to theranostics, according to the types of aptides and diseases. We show that certain aptides can not only bind to a target protein but also inhibit its biological function, thereby showing potential as therapeutics per se. Further, aptides specific for cancer-associated protein antigens can be used as escort molecules or targeting ligands for delivery of chemotherapeutics, cytokine proteins, and nanomedicines, such as liposomes and magnetic particles, to tumors, thereby substantially improving therapeutic effects. Finally, we present a strategy capable of overcoming the critical issue of short blood circulation time associated with most peptides by constructing a hybrid system between an aptide and a hapten cotinine-specific antibody.