NMR analysis, cytotoxic activity and theoretical study of a complex between SRPIN340 and p-sulfonic acid calix[6]arene.

Aim: This study aimed to enhance the aqueous dissolution of SRPK inhibitor N-(2-(piperidin-1-yl)-5-(trifluoromethyl)phenyl)isonicotinamide (SRPIN340).Materials & Methods: A complex with p-sulfonic calix[6]arene (Host) and SRPIN340 (Guest) was prepared, studied via 1H nuclear magnetic resonance (NMR) and theoretical calculations and biologically evaluated on cancer cell lines.Results & conclusion: The 1:1 host (H)/guest (G) complex significantly enhanced the aqueous dissolution of SRPIN340, achieving 64.8% water solubility as determined by 1H NMR quantification analysis. The H/G complex reduced cell viability by 75% for HL60, ∼50% for Nalm6 and Jurkat, and ∼30% for B16F10 cells. It exhibited greater cytotoxicity than free SRPIN340 against Jurkat and B16F10 cells. Theoretical studies indicated hydrogen bond stabilization of the complex, suggesting broader applicability of SRPIN340 across diverse biological systems.

[Box: see text].

Histoplasmosis in a fingolimod-treated patient: case report and scoping review.

Fingolimod is a sphingosine-1-phosphate receptor modulator used to treat multiple sclerosis. While fingolimod has been associated with an increased risk of cryptococcal meningitis, its correlation with other deep mycoses remains unclear. In this study, we conducted a scoping review of fingolimod associated with histoplasmosis, based on a case report, a literature review, and data from the FDA Adverse Events Reporting System (FAERS) as of January 24th, 2023. A 30-year-old Brazilian woman diagnosed with relapsing-remitting multiple sclerosis, receiving a daily dose of 0.5 mg of fingolimod, presented with a two-month history of fever and unintended weight loss, accompanied by lymphadenopathy, splenomegaly, and lung involvement was investigated. Biopsy of a lung nodule revealed fungal structures suggestive of Histoplasma sp. Additionally, serological testing yielded positive for Histoplasma capsulatum. Disseminated histoplasmosis should be considered in the differential diagnosis of febrile syndromes in patients undergoing fingolimod therapy for multiple sclerosis, particularly in the Americas, where this mycosis is endemic. Treatment with itraconazole and modification of immunotherapy can achieve excellent clinical outcomes.

Moving Beyond Isothiocyanates: A Look at the Stability of Conjugation Links Toward Radiolysis in 89Zr-Labeled Immunoconjugates.

Zirconium-89 is the most widely used radioisotope for immunoPET because its physical half-life (78.2 h) suits the one of antibodies. Desferrioxamine B (DFO) is the standard chelator for the complexation of zirconium(IV), and its bifunctional version, containing a phenylisothiocyanate function, is the most commonly used for the conjugation of DFO to proteins. However, preliminary results have shown that the thiourea link obtained from the conjugation of isothiocyanate and lysines is sensitive to the ionizing radiation generated by the radioisotope, leading to the rupture of the link and the release of the chelator/radiometal complex. This radiolysis phenomenon could produce nonspecific signal and prevent the detection of bone metastasis, as free zirconium accumulates into the bones. The aim of this work was to study the stability of a selection of conjugation linkers in 89Zr-labeled immunoconjugates. We have synthesized several DFO-based bifunctional chelators appended with an isothiocyanate moiety, a bicyclononyne, or a squaramate ester. Two antibodies (trastuzumab and rituximab) were conjugated and radiolabeled with zirconium-89. The effect of increasing activities of zirconium-89 on the integrity of the bioconjugate bearing thiourea links was evaluated as well as the impact of the presence of a radioprotectant. The stability of the radiolabeled antibodies was studied over 7 days in PBS and human plasma. Radioconjugates' integrity was evaluated using iTLC and size-exclusion chromatography. This study shows that the nature of the linker between the chelator and biomolecule can have a strong impact on the stability of the 89Zr-labeled conjugates, as well as on the aggregation of the conjugates.

Prophylactic mesh does not prevent parastomal hernia in long-term: Meta-analysis and trial sequential analysis.

BACKGROUND: Previous randomized clinical trials, systematic reviews, and meta-analyses evaluating parastomal hernia prevention with mesh placement during end colostomy formation have reported contradictory results. This review aimed to assess the efficacy of this strategy in long-term follow-up according to the latest available data. METHODS: Medline, EMBASE, Cochrane Library, Web of Science, and Google Scholar were searched. Randomized clinical trials were included if they compared mesh with no mesh during initial end colostomy creation in adult patients to prevent parastomal hernia with a follow-up longer than 2 years. A meta-analysis was performed to evaluate parastomal hernia incidence (primary outcome), parastomal hernia repair rate, and mortality. Subgroup analysis included surgical approach and mesh position, and trial sequential analysis was performed. RESULTS: Eight randomized clinical trials involving 537 patients met the inclusion criteria. Based on long-term follow-up, the incidence of parastomal hernia was not reduced when a prophylactic mesh was placed (relative risk = 0.68 [95% confidence interval:0.46-1.02]; I2 = 81%, P =.06). The parastomal hernia repair rate was low; however, no difference was found between the groups (relative risk = 0.90 [95% confidence interval:0.51-1.56]; I2 = 0%; P = .70), and no difference was detected between the groups when mortality was assessed (relative risk = 1.03 [95% confidence interval: 0.77-1.39]; I2 = 21%; P = .83). Subgroup analyses did not show differences according to the surgical approach or mesh position used. Regarding trial sequential analysis, an optimal information size was not achieved. CONCLUSION: Prophylactic mesh placement during end colostomy formation does not prevent parastomal hernia in the long term. The parastomal hernia repair rate and mortality rate did not vary between the included groups. Heterogeneity among the included randomized clinical trials might restrict the reliability of the results.

Histoplasmosis in a fingolimod-treated patient: case report and scoping review

ABSTRACT Fingolimod is a sphingosine-1-phosphate receptor modulator used to treat multiple sclerosis. While fingolimod has been associated with an increased risk of cryptococcal meningitis, its correlation with other deep mycoses remains unclear. In this study, we conducted a scoping review of fingolimod associated with histoplasmosis, based on a case report, a literature review, and data from the FDA Adverse Events Reporting System (FAERS) as of January 24th, 2023. A 30-year-old Brazilian woman diagnosed with relapsing-remitting multiple sclerosis, receiving a daily dose of 0.5 mg of fingolimod, presented with a two-month history of fever and unintended weight loss, accompanied by lymphadenopathy, splenomegaly, and lung involvement was investigated. Biopsy of a lung nodule revealed fungal structures suggestive of Histoplasma sp. Additionally, serological testing yielded positive for Histoplasma capsulatum. Disseminated histoplasmosis should be considered in the differential diagnosis of febrile syndromes in patients undergoing fingolimod therapy for multiple sclerosis, particularly in the Americas, where this mycosis is endemic. Treatment with itraconazole and modification of immunotherapy can achieve excellent clinical outcomes.

Perianal Paget's disease metachronically associated with adenocarcinoma

Introduction: This article describes an unusual case of perianal Paget's Disease in a 42-year-old man, highlighting distinct characteristics about more typical cases. Case report: 42-year-old male patient with persistent perianal lesion, recurrent abscesses, and discomfort. Magnetic resonance imaging indicated a possible fistulous path. Biopsy revealed secondary anal Paget's disease and adenocarcinoma. Chemotherapy and radiotherapy treatment demonstrated a positive response. Discussion: Perianal Paget's Disease is a rare condition of the anal canal that is part of the Extramammary Paget's Disease (EMPD) group. Symptoms include itching, pain, perianal bleeding, and skin lesions. Diagnosis can be challenging and usually involves performing a histopathological biopsy associated with an immunohistochemical study. Treatment varies and may involve surgery, radiotherapy, and chemotherapy. Due to the rarity of the disease, the best therapeutic approach is not yet well defined, and follow-up is essential due to the risk of recurrence. Conclusion: Perianal Paget's Disease is rare and requires differentiation from other conditions. Early detection is essential to prevent malignancy. (AU)

Synthesis and Preclinical Fluorescence Imaging of Dually Functionalized Antibody Conjugates Targeting Endothelin Receptor-Positive Tumors.

For the past two decades, the emerging role of the endothelin (ET) axis in cancer has been extensively investigated, and its involvement in several mechanisms described as "hallmarks of cancer" has clearly highlighted its potential as a therapeutic target. Despite the growing interest in finding effective anticancer drugs, no breakthrough treatment has successfully made its way to the market. Recently, our team reported the development of a new immuno-positron emission tomography probe targeting the ET A receptor (ETA, one of the ET receptors) that allows the successful detection of ETA+ glioblastoma, paving the way for the elaboration of novel antibody-based strategies. In this study, we describe the synthesis of two PET/NIRF (positron emission tomography/near-infrared fluorescence) dually functionalized imaging agents, directed against ETA or ETB, that could be used to detect ET+ tumors and select patients that will be eligible for fluorescence-guided surgery. Both imaging modalities were brought together using a highly versatile tetrazine platform bearing the IRDye800CW fluorophore and desferrioxamine for 89Zr chelation. This so-called monomolecular multimodal imaging probe was then "clicked", via an inverse-electron-demand Diels-Alder reaction, to antibodies conjugated site-specifically with a trans-cyclooctene group. This approach has led to homogeneous and well-defined constructs that retained their high affinity and high specificity for their respective target, as shown by flow cytometry and NIRF in vivo imaging experiments in nude mice bearing CHO-ETA and CHO-ETB tumors. Ultimately, these bimodal immunoconjugates could be used to improve the outcomes of patients with ET+ tumors.

SPECT Imaging of Lysyl Oxidase-like 2 in a Model of Idiopathic Pulmonary Fibrosis.

Noninvasive imaging of idiopathic pulmonary fibrosis (IPF) remains a challenge. The aim of this study was to develop an antibody-based radiotracer targeting Lysyl Oxidase-like 2 (LOXL2), an enzyme involved in the fibrogenesis process, for SPECT/CT imaging of pulmonary fibrosis. The bifunctional chelator DOTAGA-PEG4-NH2 was chemoenzymatically conjugated to the murine antibody AB0023 using microbial transglutaminase, resulting in a degree of labeling (number of chelators per antibody) of 2.3. Biolayer interferometry confirmed that the binding affinity of DOTAGA-AB0023 to LOXL2 was preserved with a dissociation constant of 2.45 ± 0.04 nM. DOTAGA-AB0023 was then labeled with 111In and in vivo experiments were carried out in a mice model of progressive pulmonary fibrosis induced by intratracheal administration of bleomycin. [111In]In-DOTAGA-AB0023 was injected in three groups of mice (control, fibrotic, and treated with nintedanib). SPECT/CT images were recorded over 4 days p.i. and an ex vivo biodistribution study was performed by gamma counting. A significant accumulation of the tracer in the lungs of the fibrotic mice was observed at D18 post-bleomycin. Interestingly, the tracer uptake was found selectively upregulated in fibrotic lesions observed on CT scans. Images of mice that received the antifibrotic drug nintedanib from D8 up to D18 showed a decrease in [111In]In-DOTAGA-AB0023 lung uptake associated with a decrease in pulmonary fibrosis measured by CT scan. In conclusion, we report the first radioimmunotracer targeting the protein LOXL2 for nuclear imaging of IPF. The tracer showed promising results in a preclinical model of bleomycin-induced pulmonary fibrosis, with high lung uptake in fibrotic areas, and accounted for the antifibrotic activity of nintedanib.

ImmunoPET imaging-based pharmacokinetic profiles of an antibody and its Fab targeting endothelin A receptors on glioblastoma stem cells in a preclinical orthotopic model.

BACKGROUND: The resistance of glioblastoma stem cells (GSCs) to treatment is one of the causes of glioblastoma (GBM) recurrence. Endothelin A receptor (ETA) overexpression in GSCs constitutes an attractive biomarker for targeting this cell subpopulation, as illustrated by several clinical trials evaluating the therapeutic efficacy of endothelin receptor antagonists against GBM. In this context, we have designed an immunoPET radioligand combining the chimeric antibody targeting ETA, chimeric-Rendomab A63 (xiRA63), with 89Zr isotope and evaluated the abilities of xiRA63 and its Fab (ThioFab-xiRA63) to detect ETA+ tumors in a mouse model xenografted orthotopically with patient-derived Gli7 GSCs. RESULTS: Radioligands were intravenously injected and imaged over time by µPET-CT imaging. Tissue biodistribution and pharmacokinetic parameters were analyzed, highlighting the ability of [89Zr]Zr-xiRA63 to pass across the brain tumor barrier and achieve better tumor uptake than [89Zr]Zr-ThioFab-xiRA63. CONCLUSIONS: This study shows the high potential of [89Zr]Zr-xiRA63 in specifically targeting ETA+ tumors, thus raising the possibility of detecting and treating ETA+ GSCs, which could improve the management of GBM patients.

Modular One-Pot Strategy for the Synthesis of Heterobivalent Tracers.

Bivalent ligands, i.e., molecules having two ligands covalently connected by a linker, have been gathering attention since the first description of their pharmacological potential in the early 80s. However, their synthesis, particularly of labeled heterobivalent ligands, can still be cumbersome and time-consuming. We herein report a straightforward procedure for the modular synthesis of labeled heterobivalent ligands (HBLs) using dual reactive 3,6-dichloro-1,2,4,5-tetrazine as a starting material and suitable partners for sequential SNAr and inverse electron-demand Diels-Alder (IEDDA) reactions. This assembly method conducted in a stepwise or in a sequential one-pot manner provides quick access to multiple HBLs. A conjugate combining ligands toward the prostate-specific membrane antigen (PSMA) and the gastrin-releasing peptide receptor (GRPR) was radiolabeled, and its biological activity was assessed in vitro and in vivo (receptor binding affinity, biodistribution, imaging) as an illustration that the assembly methodology preserves the tumor targeting properties of the ligands.

Accuracy of partially and fully guided surgical techniques for immediate implant placement: An in vitro assessment.

STATEMENT OF PROBLEM: Optimal implant positioning is essential to achieving predictable results. Computer-guided surgery has been reported to be an accurate technique for implant placement in healed sites, but the accuracy of guided techniques for immediate implant placement into fresh sockets is still unclear. PURPOSE: The purpose of this experimental randomized split-mouth study in pig jaws was to determine the accuracy of partially and fully guided surgical techniques for immediate implant placement into fresh sockets and to compare 2 different methods of implant position deviations analysis. MATERIAL AND METHODS: Twenty implants were installed in 10 pig jaws using 2 different techniques: partially guided (n=10) and fully guided (n=10). Cone beam computed tomography and digital scanning were performed before and after the surgical procedure to plan the virtual implant position and fabricate the surgical guide, as well as to determine implant position deviations. Two methods were used to evaluate implant deviations: tomographic and digital scanning. The Shapiro-Wilk test of normality was used. Deviation comparisons were carried out by using paired t tests (α=.05), and intraclass correlation coefficient (ICC) was computed to assess the agreement between the 2 methods of implant deviation analysis. RESULTS: In the tomographic analysis, the partially guided technique resulted in significantly higher global apical and lateral coronal deviations (2.25 ±0.59 mm; 0.96 ±0.55 mm) than fully guided (1.52 ±0.89 mm; 0.75 ±0.52 mm) (P<.01 and P<.05, respectively). The analysis performed using digital scanning showed significantly higher angular, global apical, and lateral apical deviations in the partially guided (6 ±3.28 degrees; 2.49 ±1.03 mm; 2.16 ±1.07 mm) technique than in the fully guided (3.32 ±1.84 degrees; 1.5 ±0.58 mm; 0.98 ±0.67 mm) (P<.05). An ICC of 0.522 between the 2 methods of implant deviation analysis was obtained. CONCLUSIONS: The partially guided technique was less accurate than the fully guided technique for immediate implant placement into fresh sockets. A moderate concordance was observed between cone beam computed tomography and digital scanning analyses, suggesting that more studies are required to validate and to define the most reliable method of measuring implant deviation.

The SRPK inhibitor N-(2-(piperidin-1-yl)-5-(trifluoromethyl)phenyl) isonicotinamide (SRPIN340) increases the immune response against metastatic melanoma in mice.

Cancers have a strong relationship with immune cells in their microenvironment, which significantly influences tumor proliferation and progression. Thus, pharmacological strategies that stimulate the immune system to combat tumor cells are promising for better therapeutic efficacy. Deregulated expression of the splicing regulatory serine arginine protein kinases (mostly SRPK1 and SRPK2) has been found in different cancer types, leading to the expression of isoforms related to tumor growth and metastasis. The microenvironment of melanoma exhibits a strong presence of immune cells, which significantly influences tumor progression, and around 50% of cutaneous melanoma patients benefit from targeted immunotherapy. Here, we analyzed human malignant melanoma single-cell gene expression data and observed that SRPK1/2 overexpression correlates with immune system pathway alterations. In further analysis, we observed an increased presence of immune cells in biopsies from mice bearing metastatic melanoma treated with SRPIN340, a well-known SRPK1/2 pharmacological inhibitor. Local treatments increased the expression of proinflammatory cytokines at the tumor lesions and the activity of the spleen, accompanied by reduced pulmonary metastasis foci, edema formation, and alveolar congestion. In in vitro assays, SRPIN340 also potentiated immunological susceptibility, by increasing the expression of the antigen presenting MHCI and MHCII molecules and by increasing the ability of B16F10 cells to attract splenic cells in transwell assays. Taken together, these results reveal that the antimetastatic effect of SRPIN340 can also involve an increased immune response, which suggests additional functional clues for SRPKs in tumor biology.

Site-Specific, Platform-Based Conjugation Strategy for the Synthesis of Dual-Labeled Immunoconjugates for Bimodal PET/NIRF Imaging of HER2-Positive Tumors.

Because positron emission tomography (PET) and optical imaging are very complementary, the combination of these two imaging modalities is very enticing in the oncology field. Such bimodal imaging generally relies on imaging agents bearing two different imaging reporters. In the bioconjugation field, this is mainly performed by successive random conjugations of the two reporters on the protein vector, but these random conjugations can alter the vector properties. In this study, we aimed at abrogating the heterogeneity of the bimodal imaging immunoconjugate and mitigating the impact of multiple random conjugations. A trivalent platform bearing a DFO chelator for 89Zr labeling, a NIR fluorophore, IRDye800CW, and a bioconjugation handle was synthesized. This bimodal probe was site-specifically grafted to trastuzumab via glycan engineering. This new bimodal immunoconjugate was then investigated in terms of radiochemistry, in vitro and in vivo, and compared to the clinically relevant random equivalent. In vitro and in vivo, our strategy provides several improvements over the current clinical standard. The combination of site-specific conjugation with the monomolecular platform reduced the heterogeneity of the final immunoconjugate, improved the resistance of the fluorophore toward radiobleaching, and reduced the nonspecific uptake in the spleen and liver compared to the standard random immunoconjugate. To conclude, the strategy developed is very promising for the synthesis of better defined dual-labeled immunoconjugates, although there is still room for improvement. Importantly, this conjugation strategy is highly modular and could be used for the synthesis of a wide range of dual-labeled immunoconjugates.

Adrenal cysts of lymphatic origin: A clinical and pathological study of six cases and systematic literature review.

Adrenal cysts are rare, benign, and usually asymptomatic, being detected as an incidental finding on imaging methods. Adrenal Cysts of Lymphatic Origin (ACLO) and Adrenal Lymphangiomas (AL) are types of endothelial cyst and are the most prevalent subtype in this series. This study aims to present a single institutional experience of these rare cysts and compare their features with those found in the review of existing literature on ACLO and AL. Overall, thirteen cases of adrenal cysts were diagnosed and surgically excised during the study period, onto which we performed immunohistochemistry using a panel of antibodies (CD31, CD34, Pan Cytokeratin AE-1/AE-3, Factor VII, D2-40, and ERG). Four cases of ACLO and two AL were found. The lesions predominantly affected right adrenal, and the majority of patients were middle-age females, of Caucasian ethnicity, and asymptomatic. In our literature review, we found 108 cases of ACLO/AL from 57 articles with similar sex and age distribution. The diagnosis and subclassification of adrenal cysts are challenging, and there is a significant overlapping between the definition of ACLO and AL.

Análise dos espaços e equipamentos de lazer de seis municípios da zona da mata de minas gerais / Analysis of spaces and leisure equipment six municipalities in the zona da mata of minas gerais

Ao se considerar o tempo necessário para a fruição do lazer, é relevante pensar aonde esses momentos/atividades podem se desenvolver nas sociedades contemporâneas, especificamente quanto à existência de espaços e equipamentos destinados ou não para este fim. Frente a isso, este estudo se desenvolveu com o objetivo de identificar e analisar os espaços e equipamentos de lazer de seis municípios da Zona da Mata Mineira, bem como verificar onde estão, como são utilizados e quais os contrastes existentes entre eles. Considerando o fenômeno abordado, a pesquisa é de natureza quali-quantitativa, de caráter observacional, através do qual o investigador atua apenas como espectador de fenômenos ou fatos, sem interferir ou realizar qualquer intervenção que venha a modificar o desfecho dos mesmos. Para cumprir o proposto, foi realizado um levantamento bibliográfico acerca do tema a fim de nortear este estudo. Posteriormente foi realizada a coleta de dados, que incluiu visitas aos municípios, identificação dos espaços e equipamentos de lazer, registro fotográfico dos mesmos e observação detalhada em relação ao uso. Os resultados indicam que o lazer não é destaque na mesorregião quando se trata de políticas públicas referentes à criação de novos espaços e equipamentos, tampouco para a manutenção dos já existentes. Há pouca diversificação dos equipamentos, visto o predomínio de quadras poliesportivas e campos de futebol nas cidades mapeadas, em razão de o esporte ser um fenômeno social e cultural de extrema importância desde o início deste século. Neste estudo, conclui-se que há diversos fatores que agem como barreiras às oportunidades de lazer nos municípios em questão. Faz-se necessário que o poder público invista em ações de fomento à democratização do lazer, sobretudo na criação de políticas públicas que incrementem e organizem as práticas do mesmo, contemplando a população e os seus diferentes interesses culturais. (AU)

When considering the time required for the enjoyment of leisure, it is relevant to think about where these moments / activities can develop in contemporary societies, specifically as to the existence of spaces and equipment intended or not for this purpose. Given this, this study was developed with the objective of identifying and analyzing the spaces and leisure equipment of six municipalities of Zona da Mata Mineira, as well as to verify where they are, how they are used and what the contrasts exist between them. Considering the phenomenon addressed, the research is qualitative and quantitative, observational in nature, whereby the researcher acts only as a spectator of phenomena or facts, without interfering or performing any intervention that may modify their outcome. To comply with the proposal, a bibliographic survey on the subject was conducted in order to guide this study. Subsequently, data collection was performed, which included visits to the municipalities, identification of spaces and leisure equipment, photographic registration of the same and detailed observation regarding the use. The results indicate that leisure is not highlighted in the mesoregion when it comes to public policies regarding the creation of new spaces and equipment, nor for the maintenance of existing ones.There is little diversification of equipment, given the predominance of multi-sport courts and soccer fields in the mapped cities, due to the fact that sport has been an extremely important social and cultural phenomenon since the beginning of this century. In this study, it is concluded that there are several factors that act as barriers to leisure opportunities in the municipalities in question. It is necessary that the public power invest in actions to promote the democratization of leisure, especially in the creation of public policies that increase and organize its practices, including the population and their different cultural interests. (AU)

Parestomal hernia repair. Prospective observational study based on the Spanish Registry of Incisional Hernia (EVEREG).

INTRODUCTION: The results of parastomal hernia (PH) repair based on data from registries are scarce. The objective of this work is to analyze the data collected on PH in the National Registry of Incisional Hernia (EVEREG) and thus evaluate current practices and results in PH repair. METHODS: Data from the PH cohort recorded in the period from July 2012 to June 2018 are analyzed. Complications, recurrences and associated factors of the entire PH cohort are analyzed, regardless of the type of stoma they are associated with. Subsequently, the same PH group analysis was performed in relation to a colostomy (larger group). RESULTS: 353 PH were studied. Of these, 259 (73%) were PH in the context of a terminal colostomy, 74 (21%) in the context of a terminal ileostomy, and 20 (6%) in the context of a ureteroileostomy (Bricker). The global mean age was 68.7 ± 11.1 years and 135 (38%) patients were female. The open approach and elective surgery were predominant (78% and 92% respectively); 99% were repaired with a non-absorbable synthetic mesh. Global postoperative complications were high (30.6%). As well as, the global recurrence (27.5%) after a mean follow-up of 9.4 months. CONCLUSIONS: PH repair is infrequent. PH surgery seems to be associated with a high percentage of postoperative complications and recurrence.

Positron Emission Tomography Imaging of Neurotensin Receptor-Positive Tumors with 68Ga-Labeled Antagonists: The Chelate Makes the Difference Again.

Neurotensin receptor 1 (NTS1) is involved in the development and progression of numerous cancers, which makes it an interesting target for the development of diagnostic and therapeutic agents. A small molecule NTS1 antagonist, named [177Lu]Lu-IPN01087, is currently evaluated in phase I/II clinical trials for the targeted therapy of neurotensin receptor-positive cancers. In this study, we synthesized seven compounds based on the structure of NTS1 antagonists, bearing different chelating agents, and radiolabeled them with gallium-68 for PET imaging. These compounds were evaluated in vitro and in vivo in mice bearing a HT-29 xenograft. The compound [68Ga]Ga-bisNODAGA-16 showed a promising biodistribution profile with mainly signal in tumor (4.917 ± 0.776%ID/g, 2 h post-injection). Its rapid clearance from healthy tissues led to high tumor-to-organ ratios, resulting in highly contrasted PET images. These results were confirmed on subcutaneous xenografts of AsPC-1 tumor cells, a model of NTS1-positive human pancreatic adenocarcinoma.

Site-Specific Dual-Labeling of a VHH with a Chelator and a Photosensitizer for Nuclear Imaging and Targeted Photodynamic Therapy of EGFR-Positive Tumors.

Variable domains of heavy chain only antibodies (VHHs) are valuable agents for application in tumor theranostics upon conjugation to both a diagnostic probe and a therapeutic compound. Here, we optimized site-specific conjugation of the chelator DTPA and the photosensitizer IRDye700DX to anti-epidermal growth factor receptor (EGFR) VHH 7D12, for applications in nuclear imaging and photodynamic therapy. 7D12 was site-specifically equipped with bimodal probe DTPA-tetrazine-IRDye700DX using the dichlorotetrazine conjugation platform. Binding, internalization and light-induced toxicity of DTPA-IRDye700DX-7D12 were determined using EGFR-overexpressing A431 cells. Finally, ex vivo biodistribution of DTPA-IRDye700DX-7D12 in A431 tumor-bearing mice was performed, and tumor homing was visualized with SPECT and fluorescence imaging. DTPA-IRDye700DX-7D12 was retrieved with a protein recovery of 43%, and a degree of labeling of 0.56. Spectral properties of the IRDye700DX were retained upon conjugation. 111In-labeled DTPA-IRDye700DX-7D12 bound specifically to A431 cells, and they were effectively killed upon illumination. DTPA-IRDye700DX-7D12 homed to A431 xenografts in vivo, and this could be visualized with both SPECT and fluorescence imaging. In conclusion, the dichlorotetrazine platform offers a feasible method for site-specific dual-labeling of VHH 7D12, retaining binding affinity and therapeutic efficacy. The flexibility of the described approach makes it easy to vary the nature of the probes for other combinations of diagnostic and therapeutic compounds.

Effect of the topical administration of N-(2-(4-bromophenylamino)-5-(trifluoromethyl)phenyl)nicotinamide compound in a murine subcutaneous melanoma model.

Conventional treatments for metastatic melanomas are still ineffective and generate numerous side effects, justifying the search for new therapies. The antimetastatic effect of the named N-(2-(4-bromophenylamino)-5-(trifluoromethyl)phenyl)nicotinamide (SRVIC30) compound has been previously demonstrated in murine melanoma. Herein, we aimed to evaluate its effect when topically administrated in a murine subcutaneous melanoma model. For that, mice C57BL/6 were injected subcutaneously with 2 × 10 B16-F10 cells. Topical treatment began when tumors became visible on animal's back. Therefore, tumor volume was measured three times a week until it reaches 12 mm approximately. At this point, 40 mg oil-in-water cream (Lanette) without (control mice; n = 10) or with SRVIC30 compound (SRVIC30 group; n = 10 animals) were spread daily over the tumor external surface using a small brush for 14 days. The treatments increased the percentage of peroxidase antioxidant enzyme and dead cells via caspase-3 activation, with a consequent deposit of collagen fibers in the tumors. In addition, the skin of treated animals showed the presence of inflammatory infiltrate. Finally, SRVIC30 did not show signs of toxicity. Thus, we concluded that the topic administration of SRVIC30 was able to influence crucial anticancer processes such as tumor cells apoptosis and surrounding microenvironment.