Targeted Hsp70 fluorescence molecular endoscopy detects dysplasia in Barrett's esophagus

Causal relationships between dietary habits and Barrett's esophagus risk: a univariable and multivariable Mendelian randomization study

Aims: Dietary habits are reported to be associated with Barrett's esophagus (BE) risk; however, whether there is a causal relationship remains controversial. Here, we systematically examined the causal effects of genetically predicted dietary habits on BE risk through a Mendelian randomization (MR) analysis approach. Methods: Data for exposures were obtained from the UK Biobank (UKB), while the summary-level data for outcomes were obtained from a large sample-size GWAS meta-analysis. Genetic variants associated with 17 ordinary dietary habits at the genome-wide significance level were regarded as instrumental variables (IVs). Univariable and multivariable MR analyses were conducted to explore the causal relationships between dietary habits and BE risk. Sensitivity analyses were implemented to evaluate robustness of the results and determine the potential pleiotropy bias. Results: Univariable MR (UVMR) analysis showed that genetic predisposition to alcohol intake frequency, cooked vegetable intake, beef intake, bread intake, fresh fruit intake, salad/raw vegetable intake, and dried fruit intake were associated with BE risk, with all P values <0.05. After adjusting confounders, the effects of four dietary habits on BE risk persisted; multivariable MR (MVMR) analysis revealed that alcohol intake frequency (adjusted odds ratio (OR) = 1.74 (1.34, 2.27); P = 3.42 × 10-5) was causally associated with higher BE risk, the cooked vegetable intake (adjusted OR = 2.64 (1.16, 5.97); P = 0.02) had suggestively increased BE risk, while higher consumption of bread (adjusted OR = 0.54 (0.32-0.91); P = 0.02) and fresh fruit (adjusted OR = 0.34 (0.15, 0.77); P = 0.01) were suggestively associated with lower BE risk. Conclusions: These MR analyses demonstrate evidence of causal relationships between dietary habits and BE risk. These findings provide new insights into targeted dietary intervention strategies for BE prevention.

PARP1-targeted fluorescence molecular endoscopy as novel tool for early detection of esophageal dysplasia and adenocarcinoma

BACKGROUND

Esophageal cancer is one of the 10 most common cancers worldwide and its incidence is dramatically increasing. Despite some improvements, the current surveillance protocol with white light endoscopy and random untargeted biopsies collection (Seattle protocol) fails to diagnose dysplastic and cancerous lesions in up to 50% of patients. Therefore, new endoscopic imaging technologies in combination with tumor-specific molecular probes are needed to improve early detection. Herein, we investigated the use of the fluorescent Poly (ADP-ribose) Polymerase 1 (PARP1)-inhibitor PARPi-FL for early detection of dysplastic lesions in patient-derived organoids and transgenic mouse models, which closely mimic the transformation from non-malignant Barrett's Esophagus (BE) to invasive esophageal adenocarcinoma (EAC).

METHODS

We determined PARP1 expression via immunohistochemistry (IHC) in human biospecimens and mouse tissues. We also assessed PARPi-FL uptake in patient- and mouse-derived organoids. Following intravenous injection of 75 nmol PARPi-FL/mouse in L2-IL1B (n = 4) and L2-IL1B/IL8Tg mice (n = 12), we conducted fluorescence molecular endoscopy (FME) and/or imaged whole excised stomachs to assess PARPi-FL accumulation in dysplastic lesions. L2-IL1B/IL8Tg mice (n = 3) and wild-type (WT) mice (n = 2) without PARPi-FL injection served as controls. The imaging results were validated by confocal microscopy and IHC of excised tissues.

RESULTS

IHC on patient and murine tissue revealed similar patterns of increasing PARP1 expression in presence of dysplasia and cancer. In human and murine organoids, PARPi-FL localized to PARP1-expressing epithelial cell nuclei after 10 min of incubation. Injection of PARPi-FL in transgenic mouse models of BE resulted in the successful detection of lesions via FME, with a mean target-to-background ratio > 2 independently from the disease stage. The localization of PARPi-FL in the lesions was confirmed by imaging of the excised stomachs and confocal microscopy. Without PARPi-FL injection, identification of lesions via FME in transgenic mice was not possible.

CONCLUSION

PARPi-FL imaging is a promising approach for clinically needed improved detection of dysplastic and malignant EAC lesions in patients with BE. Since PARPi-FL is currently evaluated in a phase 2 clinical trial for oral cancer detection after topical application, clinical translation for early detection of dysplasia and EAC in BE patients via FME screening appears feasible.

X-ray reflectivity study of the heat shock protein Hsp70 interaction with an artificial cell membrane model

Membrane-bound heat shock protein 70 (Hsp70) apart from its intracellular localization was shown to be specifically expressed on the plasma membrane surface of tumor but not normal cells. Although the association of Hsp70 with lipid membranes is well documented the exact mechanisms for chaperone membrane anchoring have not been fully elucidated. Herein, we addressed the question of how Hsp70 interacts with negatively charged phospholipids in artificial lipid compositions employing the X-ray reflectivity (XRR) studies. In a first step, the interactions between dioleoylphosphatidylcholine (DOPC) in the presence or absence of dioleoylphosphatidylserine (DOPS) and Hsp70 had been assessed using Quartz crystal microbalance measurements, suggesting that Hsp70 adsorbs to the surface of DOPC/DOPS bilayer. Atomic force microscopy (AFM) imaging demonstrated that the presence of DOPS is required for stabilization of the lipid bilayer. The interaction of Hsp70 with DOPC/DOPS lipid compositions was further quantitatively determined by high energy X-ray reflectivity. A systematic characterization of the chaperone-lipid membrane interactions by various techniques revealed that artificial membranes can be stabilized by the electrostatic interaction of anionic DOPS lipids with Hsp70.

Application of near-infrared fluorescence imaging in theranostics of gastrointestinal tumors

Gastrointestinal cancers have become an important cause of cancer-related death in humans. Improving the early diagnosis rate of gastrointestinal tumors and improving the effect of surgical treatment can significantly improve the survival rate of patients. The conventional diagnostic method is high-definition white-light endoscopy, which often leads to missed diagnosis. For surgical treatment, intraoperative tumor localization and post-operative anastomotic state evaluation play important roles in the effect of surgical treatment. As a new imaging method, near-infrared fluorescence imaging (NIRFI) has its unique advantages in the diagnosis and auxiliary surgical treatment of gastrointestinal tumors due to its high sensitivity and the ability to image deep tissues. In this review, we focus on the latest advances of NIRFI technology applied in early diagnosis of gastrointestinal tumors, identification of tumor margins, identification of lymph nodes, and assessment of anastomotic leakage. In addition, we summarize the advances of NIRFI systems such as macro imaging and micro imaging systems, and also clearly describe the application process of NIRFI from system to clinical application, and look into the prospect of NIRFI applied in the theranostics of gastrointestinal tumors.

Esophageal organoids: applications and future prospects

Organoids have been developed in the last decade as a new research tool to simulate organ cell biology and disease. Compared to traditional 2D cell lines and animal models, experimental data based on esophageal organoids are more reliable. In recent years, esophageal organoids derived from multiple cell sources have been established, and relatively mature culture protocols have been developed. Esophageal inflammation and cancer are two directions of esophageal organoid modeling, and organoid models of esophageal adenocarcinoma, esophageal squamous cell carcinoma, and eosinophilic esophagitis have been established. The properties of esophageal organoids, which mimic the real esophagus, contribute to research in drug screening and regenerative medicine. The combination of organoids with other technologies, such as organ chips and xenografts, can complement the deficiencies of organoids and create entirely new research models that are more advantageous for cancer research. In this review, we will summarize the development of tumor and non-tumor esophageal organoids, the current application of esophageal organoids in disease modeling, regenerative medicine, and drug screening. We will also discuss the future prospects of esophageal organoids.

Development of Advanced Imaging and Molecular Imaging for Barrett's Neoplasia

Barrett esophagus (BE) is a precursor to a life-threatening esophageal adenocarcinoma (EAC). Surveillance endoscopy with random biopsies is recommended for early intervention against EAC, but its adherence in the clinical setting is poor. Dysplastic lesions with flat architecture and patchy distribution in BE are hardly detected by high-resolution endoscopy, and the surveillance protocol entails issues of time and labor and suboptimal interobserver agreement for diagnosing dysplasia. Therefore, the development of advanced imaging technologies is necessary for Barrett's surveillance. Recently, non-endoscopic or endoscopic technologies, such as cytosponge, endocytoscopy, confocal laser endomicroscopy, autofluorescence imaging, and optical coherence tomography/volumetric laser endomicroscopy, were developed, but most of them are not clinically available due to the limited view field, expense of the equipment, and significant time for the learning curve. Another strategy is focused on the development of molecular biomarkers, which are also not ready to use. However, a combination of advanced imaging techniques together with specific biomarkers is expected to identify morphological abnormalities and biological disorders at an early stage in the surveillance. Here, we review recent developments in advanced imaging and molecular imaging for Barrett's neoplasia. Further developments in multiple biomarker panels specific for Barrett's HGD/EAC include wide-field imaging systems for targeting 'red flags', a high-resolution imaging system for optical biopsy, and a computer-aided diagnosis system with artificial intelligence, all of which enable a real-time and accurate diagnosis of dysplastic BE in Barrett's surveillance and provide information for precision medicine.

Impact of the Tumor Microenvironment for Esophageal Tumor Development—An Opportunity for Prevention?

Simple Summary

Researchers increasingly appreciate the tumor microenvironment (TME) for its role in the development and therapy resistance of cancers like esophageal adenocarcinoma. A better understanding of the TME fueling carcinogenesis is necessary for tailored prevention and therapies. Here, we highlight recent insights into tumor initiation, interactions with the immune system and possible novel preventative measures.

Abstract

Despite therapeutical advancements, and in contrast to other malignancies, esophageal adenocarcinoma (EAC) prognosis remains dismal while the incidence has markedly increased worldwide over the past decades. EAC is a malignancy of the distal esophageal squamous epithelium at the squamocolumnar junction with gastric cells expanding into the esophagus. Most EAC patients have a history of Barret’s esophagus (BE), a metaplastic adaption to chronic reflux, initially causing an inflammatory microenvironment. Thus, the immune system is highly involved early on in disease development and progression. Normally, anti-tumor immunity could prevent carcinogenesis but in rare cases BE still progresses over a dysplastic intermediate state to EAC. The inflammatory milieu during the initial esophagitis phase changes to a tolerogenic immune environment in BE, and back to pro-inflammatory conditions in dysplasia and finally to an immune-suppressive tumor microenvironment in EAC. Consequently, there is a huge interest in understanding the underpinnings that lead to the inflammation driven stepwise progression of the disease. Since knowledge about the constellations of the various involved cells and signaling molecules is currently fragmentary, a comprehensive description of these changes is needed, allowing better preventative measures, diagnosis, and novel therapeutic targets.

CXCR4 peptide-based fluorescence endoscopy in a mouse model of Barrett's esophagus

Background

Near-infrared (NIR) fluorescence imaging has been emerging as a promising strategy to overcome the high number of early esophageal adenocarcinomas missed by white light endoscopy and random biopsy collection. We performed a preclinical assessment of fluorescence imaging and endoscopy using a novel CXCR4-targeted fluorescent peptide ligand in the L2-IL1B mouse model of Barrett’s esophagus.

Methods

Six L2-IL1B mice with advanced stage of disease (12–16 months old) were injected with the CXCR4-targeted, Sulfo-Cy5-labeled peptide (MK007), and ex vivo wide-field imaging of the whole stomach was performed 4 h after injection. Before ex vivo imaging, fluorescence endoscopy was performed in three L2-IL1B mice (12–14 months old)  by a novel imaging system with two L2-IL1B mice used as negative controls.

Results

Ex vivo imaging and endoscopy in L2-IL1B mice showed that the CXCR4-targeted MK007 accumulated mostly in the dysplastic lesions with a mean target-to-background ratio > 2. The detection of the Sulfo-Cy5 signal in dysplastic lesions and its co-localization with CXCR4 stained cells  by confocal microscopy further confirmed the imaging results.

Conclusions

This preliminary preclinical study shows that CXCR4-targeted fluorescence endoscopy using MK007 can detect dysplastic lesions in a mouse model of Barrett’s esophagus. Further investigations are needed to assess its use in the clinical setting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00875-7.

[18F]FAPI-42 PET imaging in cancer patients: optimal acquisition time, biodistribution, and comparison with [68Ga]Ga-FAPI-04

PURPOSE

[¹⁸F]FAPI-42 is a new fibroblast activation protein (FAP)-specific tracer used for cancer imaging. Here, we describe the optimal acquisition time and in vivo evaluation of [¹⁸F]FAPI-42 and compared intra-individual biodistribution, tumor uptake, and detection ability to [⁶⁸Ga]Ga-FAPI-04.

METHODS

A total of 22 patients with various types of cancer received [¹⁸F]FAPI-42 whole-body positron emission tomography/computed tomography (PET/CT). Among them, 4 patients underwent PET/CT scans, including an early dynamic 20-min, static 1-h, and static 2-h scans. The in vivo biodistribution in normal organs and tumor uptake were semiquantitatively evaluated using the standardized uptake value (SUV) and tumor-to-background ratio (TBR). Furthermore, both [¹⁸F]FAPI-42 and [⁶⁸Ga]Ga-FAPI-04 PET/CT were performed in 12 patients to compare biodistribution, tumor uptake, and tumor detection ability.

RESULTS

[¹⁸F]FAPI-42 uptake in the tumors was rapid and reached a high level with an average SUVmax of 15.8 at 18 min, which stayed at a similarly high level to 2 h. The optimal image acquisition time for [¹⁸F]FAPI-42 was determined to be 1 h postinjection. For tumor detection, [¹⁸F]FAPI-42 had a high uptake and could be clearly visualized in the lesions. Compared to [⁶⁸Ga]Ga-FAPI-04, [¹⁸F]FAPI-42 had the same detectability for 144 positive lesions. In addition, [¹⁸F]FAPI-42 showed a higher SUVmax in liver and bone lesions (P < 0.05) and higher TBRs in liver, bone, lymph node, pleura, and peritoneal lesions (all P < 0.05).

CONCLUSION

The present study demonstrates that the optimal image acquisition time of [¹⁸F]FAPI-42 is 1 h postinjection and that [¹⁸F]FAPI-42 exhibits comparable lesion detectability to [⁶⁸Ga]Ga-FAPI-04.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2100045757).