Preclinical development of novel PD-L1 tracers and first-in-human study of [68Ga]Ga-NOTA-RW102 in patients with lung cancers.

BACKGROUND: The programmed cell death protein-1 (PD-1)/programmed death receptor ligand 1 (PD-L1) axis critically facilitates cancer cells' immune evasion. Antibody therapeutics targeting the PD-1/PD-L1 axis have shown remarkable efficacy in various tumors. Immuno-positron emission tomography (ImmunoPET) imaging of PD-L1 expression may help reshape solid tumors' immunotherapy landscape. METHODS: By immunizing an alpaca with recombinant human PD-L1, three clones of the variable domain of the heavy chain of heavy-chain only antibody (VHH) were screened, and RW102 with high binding affinity was selected for further studies. ABDRW102, a VHH derivative, was further engineered by fusing RW102 with the albumin binder ABD035. Based on the two targeting vectors, four PD-L1-specific tracers ([68Ga]Ga-NOTA-RW102, [68Ga]Ga-NOTA-ABDRW102, [64Cu]Cu-NOTA-ABDRW102, and [89Zr]Zr-DFO-ABDRW102) with different circulation times were developed. The diagnostic efficacies were thoroughly evaluated in preclinical solid tumor models, followed by a first-in-human translational investigation of [68Ga]Ga-NOTA-RW102 in patients with non-small cell lung cancer (NSCLC). RESULTS: While RW102 has a high binding affinity to PD-L1 with an excellent KD value of 15.29 pM, ABDRW102 simultaneously binds to human PD-L1 and human serum albumin with an excellent KD value of 3.71 pM and 3.38 pM, respectively. Radiotracers derived from RW102 and ABDRW102 have different in vivo circulation times. In preclinical studies, [68Ga]Ga-NOTA-RW102 immunoPET imaging allowed same-day annotation of differential PD-L1 expression with specificity, while [64Cu]Cu-NOTA-ABDRW102 and [89Zr]Zr-DFO-ABDRW102 enabled longitudinal visualization of PD-L1. More importantly, a pilot clinical trial shows the safety and diagnostic value of [68Ga]Ga-NOTA-RW102 immunoPET imaging in patients with NSCLCs and its potential to predict immune-related adverse effects following PD-L1-targeted immunotherapies. CONCLUSIONS: We developed and validated a series of PD-L1-targeted tracers. Initial preclinical and clinical evidence indicates that immunoPET imaging with [68Ga]Ga-NOTA-RW102 holds promise in visualizing differential PD-L1 expression, selecting patients for PD-L1-targeted immunotherapies, and monitoring immune-related adverse effects in patients receiving PD-L1-targeted treatments. TRIAL REGISTRATION NUMBER: NCT06165874.

Noninvasive PET imaging of tumor PD-L1 expression with 64Cu-labeled Durvalumab.

Breast cancer (BrCa) ranks as the most prevalent malignant neoplasm affecting women worldwide. The expression of programmed death-ligand 1 (PD-L1) in BrCa has recently emerged as a biomarker for immunotherapy response, but traditional immunohistochemistry (IHC)-based methods are hindered by spatial and temporal heterogeneity. Noninvasive and quantitative PD-L1 imaging using appropriate radiotracers can serve to determine PD-L1 expression in tumors. This study aims to demonstrate the viability of PET imaging with 64Cu-labeled Durvalumab (abbreviated as Durva) to assess PD-L1 expression using a murine xenograft model of breast cancer. Durvalumab, a human IgG1 monoclonal antibody against PD-L1, was assessed for specificity in vitro in two cancer cell lines (MDA-MB-231 triple-negative breast cancer cell line and AsPC-1 pancreatic cancer cell line) with positive and negative PD-L1 expression by flow cytometry. Next, we performed the in vivo evaluation of 64Cu-NOTA-Durva in murine models of human breast cancer by PET imaging and ex vivo biodistribution. Additionally, mice bearing AsPC-1 tumors were employed as a negative control. Tumor uptake was quantified based on a 3D region-of-interest (ROI) analysis of the PET images and ex vivo biodistribution measurements, and the results were compared against conventional IHC testing. The radiotracer uptake was evident in MDA-MB-231 tumors and showed minimal nonspecific binding, corroborating IHC-derived results. The results of the biodistribution showed that the MDA-MB-231 tumor uptake of 64Cu-NOTA-Durva was much higher than 64Cu-NOTA-IgG (a nonspecific radiolabeled IgG). In Conclusion, 64Cu-labeled Durvalumab PET/CT imaging offers a promising, noninvasive approach to evaluate tumor PD-L1 expression.

Mediastinal fibrosis as a late and fatal complication of treated tuberculosis mimicking a neoplastic process in a 34-year-old man.

Fibrosing mediastinitis, also known as sclerosing mediastinitis, is an uncommon condition marked by abnormal proliferation of fibrous tissue in the mediastinum. This condition may accrue either as an idiopathic condition or as a complication of an underlying disease process. Its pathogenesis remains unknown. However, most reported cases are incriminating abnormal immune-mediated hypersensitivity responses to Histoplasma infection. Other rare causes include tuberculosis, blastomycosis, and an idiopathic form that may be associated with other miscellaneous conditions. CT and MR imaging play a vital role in the diagnosis and management of this disease. We present a rare case of fibrosing mediastinitis as a late complication of tuberculosis in a 34-year-old man with a prior history of mediastinal tuberculosis, mimicking initially a neoplastic mediastinal process. We will describe this clinical case in the light of the literature and point out the contribution of radiological imaging in the diagnosis of this rare pathology.

Synchronous congenital malignant rhabdoid tumor of the orbit and cerebellar atypical teratoid/rhabdoid tumor: Case report.

Malignant rhabdoid tumor is an uncommon pediatric tumor that often arises from the kidneys but can also develop in other soft tissues including the orbits, where it is known as atypical teratoid rhabdoid tumor. Orbital location is exceptional, with just a few reported cases. Imaging allows for an accurate diagnosis, but histological confirmation is required. The treatment is yet unclear but nearly often surgical, either with or without chemotherapy. In this report, we present a case of a neonate of 1-month-old with an orbital primary malignant rhabdoid tumor with synchronous cerebellar location. The patient was unable to undergo surgery, he had chemotherapy, and unfortunately died 1 week after following palliative treatment. We will illustrate this clinical experience and point out the importance of radiological imaging in the assessment of this uncommon condition.

Unusual intracystic papilloma arising from ectopic axillary breast tissue: Case report.

Accessory breast tissue (supernumerary breast tissue) is due to the absence of regression of the primitive milk lines during embryonic life which extends from the axilla to the groin. It is mostly located in the axilla where it is often confused with the axillary extension of the breast, or any pathological process occurring in armpits. Ectopic mammary glands should not be misdiagnosed as it can potentially undergo the same pathological processes that occur in a normally located breast including benign or malignant breast tumors. We report the case of an intracystic papilloma arising from left axillary accessory breast tissue in a 63-year-old woman. The principal symptom was pain in a palpable left axillary mass without inflammatory signs. Subsequent imaging and histopathologic examination proved it to be a papillary tumor in ectopic breast tissue.

Neglected trauma-induced testicular torsion: Clinical, sonographic, and surgical correlation in a 13-year-old adolescent.

Post-traumatic testicular torsion is a rare condition, accounting for approximately 4%-8% of all reported cases of testicular torsion in the literature. Prompt clinical suspicion and intervention are crucial; as testicular torsion is considered a medical and surgical emergency that may lead to testicular necrosis. Ultrasound imaging plays an important role in assessing the integrity of the traumatized scrotum and facilitating early detection of associated testicular torsion. In this case report, we present a neglected post-traumatic testicular torsion in a 13-year-old child that led to orchiectomy.

Diagnosis and treatment of mycotic aneurysms secondary to cardiac hydatid cyst: An unusual cause of multiple cerebral strokes in a 23-year-old female.

Mycotic aneurysms (MA) are a rare but severe complication of systemic infections, carrying a high risk of rupture, hemorrhage, sepsis, and potential multiple organ failure. Intracranial arteries are often affected and present a significant mortality risk due to cerebral bleeding and ischemic strokes. In this paper we describe the case of a 23-year-old female patient who presented with a sudden onset of right hemiparesis, followed by loss of consciousness. Cerebral imaging revealed multiple infarcts in both hemispheres and intracranial hemorrhage secondary to ruptured pseudoaneurysms. On transthoracic echocardiogram, she was found to have a left ventricular cardiac cyst with mobile vegetations potentially responsible for mycotic aneurysms and cerebral strokes. The patient underwent endovascular embolization for the mycotic aneurysms and cardiac surgery for the left ventricular cyst with satisfying clinical outcomes. Postsurgical analysis revealed the cyst to be of hydatid (Echinococcus) origin.

Choroidal Mast Cells and Pathophysiology of Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) remains a leading cause of vision loss in elderly patients. Its etiology and progression are, however, deeply intertwined with various cellular and molecular interactions within the retina and choroid. Among the key cellular players least studied are choroidal mast cells, with important roles in immune and allergic responses. Here, we will review what is known regarding the pathophysiology of AMD and expand on the recently proposed intricate roles of choroidal mast cells and their activation in outer retinal degeneration and AMD pathogenesis. We will focus on choroidal mast cell activation, the release of their bioactive mediators, and potential impact on ocular oxidative stress, inflammation, and overall retinal and choroidal health. We propose an important role for thrombospondin-1 (TSP1), a major ocular angioinflammatory factor, in regulation of choroidal mast cell homeostasis and activation in AMD pathogenesis. Drawing from limited studies, this review underscores the need for further comprehensive studies aimed at understanding the precise roles changes in TSP1 levels and choroidal mast cell activity play in pathophysiology of AMD. We will also propose potential therapeutic strategies targeting these regulatory pathways, and highlighting the promise they hold for curbing AMD progression through modulation of mast cell activity. In conclusion, the evolving understanding of the role of choroidal mast cells in AMD pathogenesis will not only offer deeper insights into the underlying mechanisms but will also offer opportunities for development of novel preventive strategies.

Protective effect of selenium on vincristine-induced peripheral neuropathy in PC12 cell line.

Vincristine-induced peripheral neuropathy (VIPN) is the main side effect and major reason for neuropathic pain in cancer survivors treated with vincristine. Vincristine, a chemotherapeutic antimitotic drug, is used frequently in combination chemotherapy. The primary purpose of the current study was to assess the protective effect of sodium selenite (SSe) on VIPN in vitro. Cytotoxicity effects of vincristine were evaluated using PC12 cells as a neuronal model. The cell culture studies were conducted in three groups based on the various treatments, including vincristine, SSe, and co-exposure to both compositions. Cell viability and cell cycle analyses were performed using MTT assay and flow cytometry, respectively. The level of mRNA expression of Bax and Bcl-2 was determined using qRT-PCR. According to the results, vincristine decreased the survival rate of PC12 cells. After 24 and 48 h exposure to different concentrations of vincristine (0.1-20 µΜ), the survival rate of PC12 cells decreased as compared to the control group. The results showed that treatment with 5 µΜ of vincristine resulted in apoptosis of PC12 cells. Interestingly,co-incubation of these cells with SSe significantly reduced the cell damage induced by vincristine. Furthermore, vincristine induced the inhibition of the G2 phase in PC 12 cells, and using SSe in combination with vincristine eliminated the inhibition of the cell cycle in the G2 phase. Briefly, our in vitro preliminary study showed that SSe might protect PC12 cells from vincristine-induced peripheral neuropathy during chemotherapy.

Therapeutic roles of CAR T cells in infectious diseases: Clinical lessons learnt from cancer.

Cancer immunotherapy has made improvements due to the advances in chimaeric antigen receptor (CAR) T cell development, offering a promising treatment option for patients who have failed to respond to traditional treatments. In light of the successful use of adoptive CAR T cell therapy for cancer, researchers have been inspired to develop CARs for the treatment of other diseases beyond cancers such as viral infectious diseases. Nonetheless, various obstacles limit the efficacy of CAR T cell therapies and prevent their widespread usage. Severe toxicities, poor in vivo persistence, antigen escape, and heterogeneity, as well as off-target effect, are key challenges that must all be addressed to broaden the application of CAR T cells to a wider spectrum of diseases. The key advances in CAR T cell treatment for cancer and viral infections are reviewed in this article. We will also discuss revolutionary CAR T cell products developed to improve and enhance the therapeutic advantages of these treatments.

Designing a chimeric subunit vaccine for influenza virus, based on HA2, M2e and CTxB: a bioinformatics study.

BACKGROUND: Type A influenza viruses are contagious and even life-threatening if left untreated. So far, no broadly protective vaccine is available due to rapid antigenic changes and emergence of new subtypes of influenza virus. In this study, we exploited bioinformatics tools in order to design a subunit chimeric vaccine from the antigenic and highly conserved regions of HA and M2 proteins of H7N9 subtype of influenza virus. We used mucosal adjuvant candidates, including CTxB, STxB, ASP-1, and LTB to stimulate mucosal immunity and analyzed the combination of HA2, M2e, and the adjuvant. Furthermore, to improve the antigen function and to maintain their three-dimensional structure, 12 different linkers including six rigid linkers and six flexible linkers were used. The 3D structure model was generated using a combination of homology and ab initio modeling methods and the molecular dynamics of the model were analyzed, either. RESULTS: Analysis of different adjuvants showed that using CtxB as an adjuvant, results in higher overall vaccine stability and higher half-life among four adjuvant candidates. Fusion of antigens and the CTxB in the form of M2e-linker-CTxB-linker-HA2 has the most stability and half life compared to other combination forms. Furthermore, the KPKPKP rigid linker showed the best result for this candidate vaccine among 12 analyzed linkers. The changes in the vaccine 3D structure made by linker insertion found to be negligible, however, although small, the linker insertion between the antigens causes the structure to change slightly. Eventually, using predictive tools such as Ellipro, NetMHCpan I and II, CD4episcore, CTLpred, BepiPred and other epitope analyzing tools, we analyzed the conformational and linear epitopes of the vaccine. The solubility, proteasome cleavage sites, peptidase and potential chemical cutters, codon optimization, post translational modification were also carried out on the final vaccine. CONCLUSIONS: It is concluded that M2e-Linker-CTxB-Linker-HA2 combination of chimeric vaccine retains its 3D structure and antigenicity when KPKPKP used as linker and CTxB used as adjuvant.

Improvement, scaling-up, and downstream analysis of exosome production.

Exosomes are the most researched extracellular vesicles. In many biological, physiological, and pathological studies, they have been identified as suitable candidates for treatment and diagnosis of diseases by acting as the carriers of both drugs and genes. Considerable success has been achieved regarding the use of exosomes for tissue regeneration, cancer diagnosis, and targeted drug/gene delivery to specific tissues. While major progress has been made in exosome extraction and purification, extraction of large quantities of exosomes is still a major challenge. This issue limits the scope of both exosome-based research and therapeutic development. In this review, we have aimed to summarize experimental studies focused at increasing the number of exosomes. Biotechnological studies aimed at identifying the pathways of exosome biogenesis to manipulate some genes in order to increase the production of exosomes. Generally, two major strategies are employed to increase the production of exosomes. First, oogenesis pathways are genetically manipulated to overexpress activator genes of exosome biogenesis and downregulate the genes involved in exosome recycling pathways. Second, manipulation of the cell culture medium, treatment with specific drugs, and limiting certain conditions can force the cell to produce more exosomes. In this study, we have reviewed and categorized these strategies. It is hoped that the information presented in this review will provide a better understanding for expanding biotechnological approaches in exosome-based therapeutic development.

The Use of Mesenchymal Stem Cells and their Derived Extracellular Vesicles in Cardiovascular Disease Treatment.

BACKGROUND: Cardiovascular disease (CVD), including disorders of cardiac muscle and vascular, is the major cause of death globally. Many unsuccessful attempts have been made to intervene in the disease's pathogenesis and treatment. Stem cell-based therapies, as a regeneration strategy, cast a new hope for CVD treatment. One of the most well-known stem cells is mesenchymal stem cells (MSCs), classified as one of the adult stem cells and can be obtained from different tissues. These cells have superior properties, such as proliferation and highly specialized differentiation. On the other hand, they have the potential to modulate the immune system and anti-inflammatory activity. One of their most important features is the secreting the extracellular vesicles (EVs) like exosomes (EXOs) as an intercellular communication system mediating the different physiological and pathophysiological affairs. METHODS: In this review study, the importance of MSC and its secretory exosomes for the treatment of heart disease has been together and specifically addressed and the use of these promising natural and accessible agents is predicted to replace the current treatment modalities even faster than we imagine. RESULTS: MSC derived EXOs by providing a pro-regenerative condition allowing innate stem cells to repair damaged tissues successfully. As a result, MSCs are considered as the appropriate cellular source in regenerative medicine. In the plethora of experiments, MSCs and MSC-EXOs have been used for the treatment and regeneration of heart diseases and myocardial lesions. CONCLUSION: Administration of MSCs has been provided a replacement therapeutic option for heart regeneration, obtaining great attention among the basic researcher and the medical doctors.

The relationship between molecular content of mesenchymal stem cells derived exosomes and their potentials: Opening the way for exosomes based therapeutics.

At least, more than half of our understanding of extracellular vesicles owes to the studies conducted over the past few years. When it became clear that the exosomes have various potentials in medicine, extensive research has focused on these potentials in a variety of areas including cancer, drug delivery and regenerative medicine. The growing understanding of molecular structure and functions of exosomes causes the vision to become brighter in the exosomes complexity, and our attitude toward these vesicles has undergone changes accordingly. Proteomic and transcriptomic studies on exosomes have highlighted their molecular diversity. In this review, we explicitly examine the exosomes composition, molecular structure and their therapeutic potentials in some diseases. Due to the very heterogeneous nature of exosomes, the process of their use as a therapeutic agent in the clinic has been challenged. We are still at the beginning of recognizing the molecular composition of exosomes and mechanisms that affect their physiology and biology. The growing trend of engineering of exosomes has shown a promising future to further utilize them in a different field. Molecular profiling of exosomes and their content for their related potentials in regenerative medicine should be done exactly for further defining a minimum content for specific therapeutic potentials.

Nucleic acid aptamers in diagnosis of colorectal cancer.

Nucleic acid aptamers are promising recognition ligands for diagnostic applications. They are short DNA or RNA molecules isolated from large random libraries through the Systematic Evolution of Ligands by EXponential enrichment (SELEX) procedure. These molecules, with a particular three-dimensional shape, bind to a wide range of targets from small molecules to whole cells with high affinity and specificity. The unique properties of nucleic acid aptamers including high binding affinity and specificity, thermostability, ease of chemical production, ease of chemical modification, target adaptability, simple storage, resistance to denaturation, low immunogenicity, and low cost make them potential diagnostic tools for clinical use. Colorectal cancer is one of the most common types of cancer in humans and the third leading cause of cancer deaths in the world. Due to low response rate to current therapies in advanced stages of the disease, early detection of CRC can be useful in disease management. This review highlights recent advances in the development of nucleic acid aptamer-based methods for diagnosis, prognosis, and theranosis of colorectal cancer.

Sulforaphane, a Chemopreventive Compound, Inhibits Cyclooxygenase-2 and Microsomal Prostaglandin E Synthase-1 Expression in Human HT-29 Colon Cancer Cells.

BACKGROUND: A high expression of prostaglandin E2 (PGE2) is found in colorectal cancer. Therefore, blocking of PGE2 generation has been identified as a promising approach for anticancer therapy. Sulforaphane (SFN), an isothiocyanate derived from glucosinolate, is used as the antioxidant and anticancer agents. METHODS: HT-29 cells were treated with various concentrations of SFN and compared to untreated cells for the expression of microsomal prostaglandin E synthase-1 (mPGES-1), cyclooxygenase 2 (COX-2), hypoxia-inducible factor-1 (HIF-1), C-X-C chemokine receptor type 4 (CXCR4), vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-2 and MMP-9 at the mRNA level. The PGE2 level was measured by ELISA assay. Apoptosis was evaluated by the proportion of sub-G1 cells. The activity of caspase-3 was determined using an enzymatic assay. HT-29 cell migration was assessed using a scratch test. RESULTS: SFN preconditioning decreased the expression of COX-2, mPGES-1, HIF-1, VEGF, CXCR4, MMP-2, and MMP-9. An apoptotic effect of SFN was preceded by the activation of caspase-3 as well as accumulation of cells in the sub-G1 phase of the cell cycle. SFN decreased PGE2 generation and inhibited the in vitro motility/wound-healing activity of HT-29 cells. CONCLUSIONS: SFN anticancer effects are associated with antiproliferative, antiangiogenic, and antimetastatic activities arising from the downregulation of the COX-2/ mPGES-1 axis.

Promigratory and proangiogenic effects of AdipoRon on bone marrow-derived mesenchymal stem cells: an in vitro study.

OBJECTIVES: To investigate the effect of AdipoRon on major factors involved in survival, migration and neovascularization of rat bone marrow-derived mesenchymal stem cells. RESULTS: AdipoRon promoted the MSCs viability. Real-time PCR indicated that the expression of cyclooxygenase-2 (COX-2), hypoxia-inducible factor-1 (HIF-1) C-X-C chemokine receptor type 4 (CXCR4), C-C chemokine receptor type 2 (CCR2), vascular endothelial growth factor matrix metalloproteinase-2 (MMP-2) and MMP-9 were upregulated in AdipoRon-treated MSCs compared to control groups. Prostaglandin E2 (PGE2) level, as well as migration ability of MSCs (scratch assay) was enhanced by AdipoRon preconditioning. CONCLUSION: Preconditioning of MSCs with AdipoRon prior to transplantation could enhance cell survival, angiogenesis and migration via activating the COX-2/PGE2/HIF-1 pathway and other contributing factors.

Cytoprotective effects of endothelin-1 on mesenchymal stem cells: an in vitro study.

Stem cell-based therapies is a promising approach for regenerative therapy in various diseases. Some obstacles remain to be solved before clinical application of the cell therapy is realized, including increasing the survival of transplanted stem cells, reducing loss of transplanted cells, and maintaining adequate vascular supply. Recently, stem cell preconditioning with chemical and pharmacological agents has been shown to increase therapeutic efficacy. The present study investigated the effect of endothelin-1 (ET-1) on survival, angiogenesis, and migration of mesenchymal stem cells (MSCs), in vitro. MSCs were treated with various concentrations of ET-1 and the expression of cyclooxygenase-2 (COX-2), hypoxia-inducible factor-1 (HIF-1), C-X-C chemokine receptor type 4 (CXCR4), C-C chemokine receptor type 2 (CCR2), vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2), angiopoietin-4 (Ang-4) and matrix metalloproteinase-2 (MMP-2) were examined. Caspase 3 activity and prostaglandin E2 (PGE2) were determined by ELISA assay. MSCs migration and tube formation potential were assessed using scratch test and three dimensional vessel formation assay. ET-1 enhanced the MSCs viability. In ET-1- treated MSCs, expression of COX-2, HIF-1, CXCR4, CCR2, VEGF, Ang-2, Ang-4 and MMP-2 were increased compared to control groups. Elevation of all these genes were reversed by celecoxib (50 µmol/L), a selective COX-2 inhibitor. PGE2 generation, MSCs migration and tube formation were enhanced by ET-1 conditioning, whereas caspase-3 activity was reduced in these cells, compared to the control group. The results presented here reveal that preconditioning of MSCs with ET-1 has strong cytoprotective effects through activation of survival signalling molecules and trophic factors.