Four-Color SERS Monitoring of Size-dependent Nanoparticle Delivery in the Same Tumor.

The physicochemical properties of nanoparticles (NPs) significantly influence their deposition at the disease site, ultimately impacting the overall therapeutic efficacy; however, precisely assessing the effects of various factors on NP accumulation within a single cell/tumor tissue is challenging due to the lack of appropriate labeling techniques. Surface-enhanced Raman spectroscopy (SERS) tag is a powerful encoding method that has recently been intensively employed for immunodetection of biomarkers. Herein, we introduce a multiplexed SERS tracking approach for systematic investigation of size-dependent accumulation and distribution of NPs within the same tumor. Four-sized (34, 60, 108, and 147 nm) NPs encoded with different SERS "colors" were fabricated, mixed, and incubated with monolayer tumor cells, multicellular tumor spheroids, or injected into mouse models bearing xenograft solid tumors in a single dose. Multicolor SERS detection of the specimens revealed that NP accumulation in tumor cells, tumor spheroids, and solid tumors was in the order of 34 nm > 60 nm > 108 nm > 147 nm, 60 nm > 34 nm > 108 nm > 147 nm, and 34 nm > 147 nm > 108 nm > 60 nm, respectively. Inductively coupled plasma mass spectroscopy determination performed in parallel samples were in alignment with the four-color SERS probing results, demonstrating the effectiveness of this multiplexed evaluation assay. Furthermore, in combination with fluorescence labeling of specific biomolecules, this method can be applied for the colocalization of different NPs in various pathological structures and provide additional information for analysis of the possible mechanisms.

2, 2-dimethylthiazolidine hydrochloride protects against experimental contrast-induced acute kidney injury via inhibition of tubular ferroptosis.

Contrast-induced acute kidney injury (CI-AKI) has become the third leading cause of AKI acquired in hospital, lacking of effective interventions. In the study, we identified the renal beneficial role of 2, 2-dimethylthiazolidine hydrochloride (DMTD), a safer compound which is readily hydrolyzed to cysteamine, in the rodent model of CI-AKI. Our data showed that administration of DMTD attenuated the impaired renal function and tubular injury induced by the contrast agent. Levels of MDA, 4-hydroxynonenal, ferrous iron and morphological signs showed that contrast agent induced ferroptosis, which could be inhibited in the DMTD group. In vitro, DMTD suppressed ferroptosis induced by ioversol in the cultured tubular cells. Treatment of DMTD upregulated glutathione (GSH) and glutathione peroxidase 4 (GPX4). Moreover, we found that DMTD promoted the ubiquitin-mediated proteasomal degradation of Keap1, and thus increased the activity of nuclear factor erythroid 2-related factor 2 (Nrf2). Mechanistically, increase of the ubiquitylation degradation of Keap1 mediates the upregulated effect of DMTD on Nrf2. Consequently, activated Nrf2/Slc7a11 results in the increase of GSH and GPX4, and therefore leads to the inhibition of ferroptosis. Herein, we imply DMTD as a potential therapeutic agent for the treatment of CI-AKI.

Role of body composition and metabolic parameters extracted from baseline 18F-FDG PET/CT in patients with diffuse large B-cell lymphoma.

This study aimed to clarify the clinical and prognostic role of body composition and metabolic parameters extracted from baseline 18F-FDG PET/CT in patients with diffuse large B-cell lymphoma (DLBCL). We retrospectively collected the clinicopathological and 18F-FDG PET/CT parameters of 181 DLBCL patients. The indexes of skeletal muscle, subcutaneous adipose tissue, and visceral adipose tissue were calculated using the area measured at the 3rd lumbar level normalized for height. Additionally, the metabolic activity of corresponding muscle and adipose tissue, and maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of all lesions were measured. Survival endpoints included progression-free survival (PFS) and overall survival (OS). We identified 75 (41.4%) patients with low skeletal muscle index (sarcopenia), presenting risk factors including male, high ß2-microglobulin, low BMI, high visceral adipose tissue index, low SUVmax of skeletal muscle, and high SUVmax of visceral adipose tissue. Male, low BMI, low visceral adipose tissue index, and high SUVmax of subcutaneous adipose tissue were risk factors for low subcutaneous adipose tissue index diagnosed in 105 (58.0%) patients. In total, 132 (79.2%) patients represented low visceral adipose tissue index, associated with younger age, B symptoms, and low BMI. Eastern Cooperative Oncology Group (ECOG) status, sarcopenia, and visceral adipose tissue index were found independently predictive of PFS and OS, while ß2-microglobulin was independently predictive of OS. In conclusion, body composition indexes were correlated with both clinical characteristics and 18F-FDG PET/CT metabolic parameters, significantly impacting survival, such that sarcopenia and high visceral adipose tissue index were powerful predictors of poor DLBCL outcomes.

Clinical and prognostic role of 2-[18F]FDG PET/CT and sarcopenia in treatment-naïve patients with T-cell lymphoblastic lymphoma.

T-cell lymphoblastic lymphoma (T-LBL) is a rare and highly aggressive non-Hodgkin lymphoma. This study aimed to explore the role of 2-[18F]FDG PET/CT, sarcopenia, clinical features, and treatment regimens in 49 treatment-naïve patients with T-LBL, and assess their predictive value in the prognosis. Sarcopenia was measured as skeletal muscle index (SMI) at L3 level from the CT component of PET/CT images. All 49 patients (35 males, 14 females; median age, 26 years [range, 3-66 years]) were enrolled in this study, including 36 adult patients and 13 pediatric patients. Lymph nodes, thymus, bone marrow, and pleura were the most common involved sites of T-LBL. The median SUVmax, MTV, and TLG of all lesions in these 49 patients were 12.4 (range, 4.2-40.5), 532.6 (17.4-3518.1), and 2112.2 (53.9-18,699.2), respectively. Eighteen out of 49 patients (36.7%) were diagnosed with sarcopenia. Sarcopenia patients had lower BMI and SUVmax of muscle at L3 level than non-sarcopenia patients (P < 0.05). Univariate Cox regression analysis indicated that higher MTV and TLG and intrathecal therapy (IT) were associated with longer progression-free survival (PFS) and overall survival (OS), while multivariate Cox regression analysis showed that TLG and IT were independent predictors for PFS, and only IT was an independent predictor for OS. In conclusion, low BMI and SUVmax of muscle at L3 level correlated with sarcopenia in T-LBL patients. Higher initial MTV and TLG and receiving IT were associated with better prognosis in T-LBL patients. TLG and IT, but not sarcopenia, were independent prognostic factors.

68Ga-Labeled Cystine Knot Peptide Targeting Integrin αvß6 for Lung Cancer PET Imaging.

Integrin αvß6 has been considered as a promising biomarker for lung cancer, and its expression is often related to poor prognosis. An αvß6-binding cystine knot peptide R01-MG was previously engineered and validated. Here, we developed a positron emission tomography (PET) probe of R01-MG for imaging αvß6-positive lung cancer. Cystine knot peptide R01-MG was synthesized through solid-phase peptide synthesis chemistry and radiolabeled with 68Ga after being conjugated with 1,4,7,10-tetraazacyclododecane-N,N',N″,N‴-tetraacetic acid (DOTA). The stability of 68Ga-DOTA-R01-MG was analyzed in phosphate-buffered saline (PBS) (pH 7.4) and fetal bovine serum (FBS). The cell uptake assay of the probe was evaluated using αvß6-positive (A549 and H1975) and αvß6-negative (H1299) lung cancer cell lines. In addition, small animal PET imaging and biodistribution studies of 68Ga-DOTA-R01-MG were performed in αvß6-positive and αvß6-negative lung cancer models. Our study showed that 68Ga-DOTA-R01-MG exhibited excellent stability in PBS and FBS. Small animal PET imaging and biodistribution data revealed that 68Ga-DOTA-R01-MG displayed rapid and good tumor uptake in animal models with αvß6-positive lung cancer, and the probe was rapidly cleared from the normal tissues, resulting in good tumor-to-normal tissue contrasts. Meanwhile, no obvious tumor uptake of 68Ga-DOTA-R01-MG was observed in animal models with αvß6-negative lung cancer, demonstrating specific binding of the probe to integrin αvß6. In conclusion, 68Ga-DOTA-R01-MG has great potential to be a promising PET tracer for imaging αvß6-positive lung cancer.

Combined legumain- and integrin-targeted nanobubbles for molecular ultrasound imaging of breast cancer.

Molecular ultrasound imaging is a promising strategy for non-invasive and precise cancer diagnosis. Previously reported ultrasound contrast agents (UCAs) are mostly microbubbles or nanobubbles (NBs) larger than 200 nm, leading to less efficient tumor delivery. Here we synthesized NBs with a small size (~49 nm) and modified the NB surface with alanine-alanine-asparagine (NB-A) or arginine-glycine-aspartic acid peptide (NB-R) for concurrent active targeting towards legumain in tumor cells and integrin in tumor neovasculature. In vitro, the NB-A and NB-R presented echogenicity comparable with SonoVue MBs and showed specific binding with tumors cells and endothelial cells, respectively. In vivo, the combined NB-A/NB-R accumulated in tumor tissues selectively and provided ultrasound signals with prolonged duration and that were significantly stronger than non-targeted NBs, single-targeted NBs and SonoVue MBs. Overall, the dual targeted NBs served as efficient UCAs for specific imaging of breast cancer, and hold great potential for general cancer diagnosis/monitoring in the future.

18F-FDG PET/CT and clinicopathological characteristics of neurolymphomatosis in lymphoma patients.

OBJECTIVE: Neurolymphomatosis (NL) is a rare but serious manifestation defined as invasion of peripheral nervous system by malignant lymphocytes. Thus, this study investigated fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and clinicopathological characteristics of NL in lymphoma patients. SUBJECTS AND METHODS: Clinicopathological and 18F-FDG PET/CT findings and treatment regimens were retrospectively investigated in 20 lymphoma patients with NL, and analyzed their correlation with progression-free survival (PFS) and overall survival (OS). RESULTS: These 20 lymphoma patients (11 males, 9 females; median age, 49 years) included 10 primary and 10 secondary NL patients. Non-Hodgkin's lymphoma (NHL) was noted in 19 patients, B-cell NHL was associated with 18 cases, and diffuse large B-cell lymphoma was the most common. Notably, 18 patients were aggressive lymphoma while 2 were indolent lymphoma. The affected neural structures included nerve roots (n=17), peripheral nerves (n=3), cranial nerves (n=3), and neural plexus (n=2). Fluorine-18-FDG was avid in all cases, and the median maximum standardized uptake value (SUVmax) of neural and all lesions was 12.2 (range, 3.3-25.6) and 15.0 (range, 4.4-34.2), respectively. The median PFS and OS of all patients were 9.3 and 14.3 months. The 12-month OS rate of 18 patients with aggressive lymphoma receiving intrathecal chemotherapy/autologous stem cell transplants (IT chem/ASCT) was significantly higher than who did not (64.8% vs 15.9%). CONCLUSION: The majority of NL occurred in patients with aggressive lymphoma, of which B-cell NHL were the predominant subtypes. Fluorine-18-FDG PET/CT imaging of NL was mainly characterized by intense glucose accumulation alongside peripheral nerves, and IT chem/ASCT was suggested to improve the outcomes of NL.

18F-FDG PET/CT imaging of multiple intrahepatic Epstein-Barr virus-associated smooth muscle tumors in a pediatric patient after heart transplantation.

Epstein-Barr virus-associated smooth muscle tumor (EBV-SMT) is an exceedingly rare neoplastic disease with a predisposition in immune-compromised individuals, especially in patients with prior transplantation, human immunodeficiency virus infection, or congenital immunodeficiency. Here, we present imaging findings of EBV-SMT in multiphasic contrast-enhanced computed tomography (CT) and fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT in a two-and-a-half-year-old boy with prior heart transplantation.

Colorimetric analysis of extracellular vesicle surface proteins based on controlled growth of Au aptasensors.

Protein profiling of extracellular vesicles (EVs) provides important information in both clinical cancer diagnosis and relevant biological research studies. Although a variety of bioanalytical techniques have been investigated for EV characterization, limitations such as time-consuming operations, the requirement of large sample volume and demand for specialized instruments hinder their practical applications. Here, we report a simple and wash-free homogeneous colorimetric assay for sensitive detection of surface proteins on EVs. Au nanoparticles were modified with thiolated aptamers to fabricate aptasensors and incubated with EVs. Upon addition of a Au growth reagent, the solution color changed from light red to blue in the presence of target proteins and became deep red when the targets were absent. Expression of CD63, epithelial cell adhesion molecules (EpCAM), and mucin1 in EVs derived from two breast cancer cell lines (MCF-7 and MDA-MB-231) were compared, showing results consistent with western blotting results. The colorimetric assay achieves a limit of detection (LOD) down to 0.7 ng µL-1 against MCF-7 EVs based on the assessment of EpCAM expression, suggesting its potential to be applied in clinical breast cancer diagnosis.

Skipping of an exon with a nonsense mutation in the DMD gene is induced by the conversion of a splicing enhancer to a splicing silencer.

Modulation of dystrophin pre-mRNA splicing is an attractive strategy to ameliorate the severe phenotype of Duchenne muscular dystrophy (DMD), although this requires a better understanding of the mechanism of splicing regulation. Aberrant splicing caused by gene mutations provides a good model to study splicing regulatory cis-elements and binding proteins. In this study, we identified skipping of in-frame exon 25 induced by a nonsense mutation (NM_004006.2:c.3340A > T;p.Lys1114*) in the DMD gene. Site-directed mutagenesis study in minigenes suggested that c.3340A > T converts an exonic splicing enhancer sequence (ESE) to a silencer element (ESS). Indeed, RNA pull-down and functional study provided evidence that c.3340A > T abolishes the binding of the splicing enhancer protein Tra2ß and promotes interactions with the repressor proteins hnRNP A1, hnRNP A2, and hnRNP H. By carefully analyzing the sequence motif encompassing the mutation site, we concluded that the skipping of exon 25 was due to disruption of a Tra2ß-dependent ESE and the creation of a new ESS associated with hnRNP A1 and hnRNP A2, which in turn increased the recruitment of hnRNP H to a nearby binding site. Finally, we demonstrated that c.3340A > T impairs the splicing of upstream intron 24 in a splicing minigene assay. In addition, we showed that the correct splicing of exon 25 is finely regulated by multiple splicing regulators that function in opposite directions by binding to closely located ESE and ESS. Our results clarify the detailed molecular mechanism of exon skipping induced by the nonsense mutation c.3340A > T and also provide information on exon 25 splicing.