[Clinical characteristics and prognosis analysis of pulmonary sarcomatoid carcinoma]

Objective: To summarize the clinical characteristics, treatment, and outcomes of patients with pulmonary sarcomatoid carcinoma (PSC) in order to improve clinicians' understanding of this disease. Methods: The clinical data of patients diagnosed with PSC in our hospital from January 1, 2015 to November 30, 2023 were retrospectively analyzed. According to whether radical resection was performed, the patients were divided into resectable group and unresectable group. The characteristics and treatments of PSC in different groups were compared. The survival curves were drawn by Kaplan-Meier method to compare the prognosis of different groups of patients. Results: A total of 43 PSC patients were included, including 32 males, with an average age of (62.79±9.59) years, and 31 smokers. Peripheral-type tumors were more common, with imaging showing predominantly solid soft tissue masses, and the maximum diameter of the tumor was more than 5 cm in 14 patients. Among the 23 patients who underwent NGS gene testing, the KRAS mutation rate was 43.5%, the TP53 mutation rate was 30.4%, and the MET mutation rate was 8.7%, all of which were MET-14 exon skipping mutations. PD-L1 expression was detected in 13 patients, 10 of whom showed high expression. The median overall survival (mOS) of the 43 patients with PSC was 24.6 months (13.0-52.7 months). Among them, 22 patients underwent radical lobectomy plus mediastinal lymph node dissection, 13 patients had postoperative recurrence, and 7 patients died during follow-up. The median disease-free survival (mDFS) was 12.3 months, the mOS was not achieved and the 1-year OS rate was 77.3 %. Twenty-one patients had unresectable locally advanced or advanced stage, and 15 patients died. The mDFS was 2.5 months, the mOS was 6.2 months, and the 1-year OS rate was 42.9 %. Seventeen patients received immunotherapy, and 1 patient received targeted therapy with the MET inhibitor glumetinib. Conclusions: PSC has a higher incidence in the elderly, smokers, and males, is highly malignant and has a poor prognosis. Based on its molecular biological characteristics, PD-L1 expression and tumor molecular detection can be performed to guide treatment options.

Comparison of outcomes between preservation or division of the uterine round ligament in laparoscopic groin hernia repair in females: a meta-analysis and trial sequential analysis

PURPOSE

The purpose of this study was to perform a meta-analysis comparing the short-term and long-term outcomes in laparoscopic groin hernia repair with or without preservation of the uterine round ligament (URL) in females.

METHODS

We searched several databases including PubMed, Web of Science, Cochrane Library, and and CNKI databases. This meta-analysis included randomized clinical trials, and retrospective comparative studies regarding preservation or division of the URL in laparoscopic groin hernia repair in females. Outcomes of interest were age, BMI, type of hernia, type of surgery, operating time, estimated blood loss, time of hospitalization, seroma, concomitant injury, mesh infection, recurrence, uterine prolapse, foreign body sensation, chronic pain, and pregnancy. Meta-analyses and trial sequential analysis were performed with Review Manager v5.3 and TSA software, respectively.

RESULTS

Of 192 potentially eligible articles, 9 studies with 1104 participants met the eligibility criteria and were included in the meta-analysis. There were no significant difference in age (MD-6.58, 95% CI - 13.41 to 0.24; P = 0.06), BMI (MD 0.05, 95%CI - 0.31 to 0.40; P = 0.81), blood loss (MD-0.04, 95% CI - 0.75 to 0.66; P = 0.90), time of hospitalization (MD-0.22, 95% CI-1.13 to 0.69; P = 0.64), seroma (OR 0.71, 95% CI 0.41 to 1.24; P = 0.23), concomitant injury (OR 0.32, 95% CI 0.01 to 8.24; P = 0.68), mesh infection (OR 0.13, 95% CI 0.01 to 2.61; P = 0.18), recurrence (OR 1.13, 95% CI 0.18 to 7.25; P = 0.90), uterine prolapse(OR 0.71, 95% CI 0.07 to 6.94; P = 0.77), foreign body sensation (OR 1.95, 95% CI 0.53 to 7.23; P = 0.32) and chronic pain(OR 1.03 95% CI 0.4 to 2.69; P = 0.95). However, this meta-analysis demonstrated a statistically significant difference in operating time (MD 6.62, 95% CI 2.20 to 11.04; P = 0.0003) between the preservation group and division group. Trial sequential analysis showed that the cumulative Z value of the operating time crossed the traditional boundary value and the TSA boundary value in the third study, and the cumulative sample size had reached the required information size (RIS), indicating that the current conclusion was stable.

CONCLUSION

In summary, laparoscopic groin hernia repair in women with the preservation of the round uterine ligament requires a longer operating time, but there was no advantage in short-term or long-term complications, and there was no clear evidence on whether it causes infertility and uterine prolapse.

Engineering Hydroxylase Activity, Selectivity, and Stability for a Scalable Concise Synthesis of a Key Intermediate to Belzutifan

Biocatalytic oxidations are an emerging technology for selective C-H bond activation. While promising for a range of selective oxidations, practical use of enzymes catalyzing aerobic hydroxylation is presently limited by their substrate scope and stability under industrially relevant conditions. Here, we report the engineering and practical application of a non-heme iron and α-ketoglutarate-dependent dioxygenase for the direct stereo- and regio-selective hydroxylation of a non-native fluoroindanone en route to the oncology treatment belzutifan, replacing a five-step chemical synthesis with a direct enantioselective hydroxylation. Mechanistic studies indicated that formation of the desired product was limited by enzyme stability and product overoxidation, with these properties subsequently improved by directed evolution, yielding a biocatalyst capable of >15,000 total turnovers. Highlighting the industrial utility of this biocatalyst, the high-yielding, green, and efficient oxidation was demonstrated at kilogram scale for the synthesis of belzutifan.

[A case report of ocular monkeypox]

A 35-year-old male patient arrived at the clinic, reporting a persistent issue of his right eye being difficult to open for the past three weeks. Alongside this, he had been experiencing a gradual development of lesions around the eye. Notably, about a month prior to the onset of these symptoms, the patient had engaged in unprotected intercourse with a male partner. The initial manifestation was a papule near the eye, which then rapidly progressed. Laboratory analysis of samples taken from the lesions confirmed the presence of monkeypox through polymerase chain reaction testing. Furthermore, this patient received positive diagnoses for both HIV and syphilis infections. Notably, his absolute CD4 count was measured at an extremely low level of 2 cells/μl.(This article was published ahead of print on the official website of Chinese Journal of Ophthalmology on September 18, 2023).

Rapid Unambiguous Structure Elucidation of Streptnatamide A, a New Cyclic Peptide Isolated from A Marine-derived Streptomyces sp

Cyclic peptides have been excellent source of drug leads. With the advances in discovery platforms, the pharmaceutical industry has a growing interest in cyclic peptides and has pushed several into clinical trials. However, structural complexity of cyclic peptides brings extreme challenges for structure elucidation efforts. Isotopic fine structure analysis, Nuclear magnetic resonance (NMR), and detailed tandem mass spectrometry rapidly provided peptide sequence for streptnatamide A, a cyclic peptide isolated from a marine-derived Streptomyces sp. Marfey's analysis determined the stereochemistry of all amino acids, enabling the unambiguous structure determination of this compound. A non-ribosomal peptide synthetase biosynthetic gene cluster (stp) was tentatively identified and annotated for streptnatamide A based on the in silico analysis of whole genome sequencing data. These analytical tools will be powerful tools to overcome the challenges for cyclic peptide structure elucidation and accelerate the development of bioactive cyclic peptides.

[The efficacy and safety of standardized dust mite allergen subcutaneous immunotherapy in children with allergic rhinitis during treatment]

Objective: To evaluate the efficacy and safety of standardized dust mite allergen subcutaneous immunotherapy (SCIT) in children with allergic rhinitis (AR) during treatment. Methods: A total of 283 children with AR diagnosed with definite dust mite allergy and completed 2 to 3 years of SCIT who attended the Department of Otorhinolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, from August 2019 to October 2021 were included, including 205 males and 78 females, with a mean age of 10.8 years. The total nasal symptoms score (TNSS), symptom medication score (SMS), rhinoconjunctivitis quality of life questionnaire (RQLQ) and visual analogue scale (VAS) before and after 2 to 3 years' treatment were recorded, and the differences before and after treatment were compared. Adverse reactions during SCIT were recorded to evaluate its safety. SPSS 22.0 software was used for statistical analysis. Results: The overall effectiveness rate during SCIT in 283 children with AR was 89.4% (253/283). Compared with baseline, all symptom scores, medication scores and quality of life scores were significantly lower after 2 to 3 years of SCIT (all P<0.05). Further group comparisons showed positive efficacy in patients with different clinical characteristics, including age, gender, smoking status, family history of AR, symptom severity, mono-or poly-allergy, and second immunization, with no statistically significant differences between groups (all P>0.05). A total of 12 735 injections were administered during the SCIT, and a total of 213 (1.67%) injections of local adverse reactions occurred, mainly in the initial treatment phase, and the diameter of the local air mass was mostly 5 to 20 mm; 71 (0.56%) injections of systemic adverse reactions occurred, mainly in the initial treatment phase, and most of them were grade 1 reactions with no serious systemic adverse reaction such as shock. Conclusion: Standardized dust mite SCIT has a good safety profile and definite efficacy in treating AR children with different clinical characteristics. It can significantly improve all symptoms, reduce the use of symptomatic drugs and improve their quality of life.

[Statin-related drug-induced liver injury]

Statins are a kind of prescription drug that is widely used to treat hyperlipidemia, coronary artery disease, and other atherosclerotic diseases. A common side effect of statin use is a mild rise in liver aminotransferases, which occurs in less than 3% of patients. Statin-related liver injury is most commonly caused by atorvastatin and simvastatin, but severe liver injury is uncommon. Therefore, understanding and evaluating hepatotoxicity and weighing the benefits and risks is of great significance to better realize the protective effect of statins.

Medical Care Use Among Patients with Monogenic Osteoporosis Due to Rare Variants in LRP5, PLS3, or WNT1

Pathogenic variants in the LRP5, PLS3, or WNT1 genes can significantly affect bone mineral density, causing monogenic osteoporosis. Much remains to be discovered about the phenotype and medical care needs of these patients. The purpose of this study was to examine the use of medical care among Dutch individuals identified between 2014 and 2021 with a pathogenic or suspicious rare variant in LRP5, PLS3, or WNT1. In addition, the aim was to compare their medical care utilization to both the overall Dutch population and the Dutch Osteogenesis Imperfecta (OI) population. The Amsterdam UMC Genome Database was used to match 92 patients with the Statistics Netherlands (CBS) cohort. Patients were categorized based on their harbored variants: LRP5, PLS3, or WNT1. Hospital admissions, outpatient visits, medication data, and diagnosis treatment combinations (DTCs) were compared between the variant groups and, when possible, to the total population and OI population. Compared to the total population, patients with an LRP5, PLS3, or WNT1 variant had 1.63 times more hospital admissions, 2.0 times more opened DTCs, and a greater proportion using medication. Compared to OI patients, they had 0.62 times fewer admissions. Dutch patients with an LRP5, PLS3, or WNT1 variant appear to require on average more medical care than the total population. As expected, they made higher use of care at the surgical and orthopedic departments. Additionally, they used more care at the audiological centers and the otorhinolaryngology (ENT) department, suggesting a higher risk of hearing-related problems.

Determination of ultra-trace metal-protein interactions in co-formulated monoclonal antibody drug product by SEC-ICP-MS

Transition metals can be introduced in therapeutic protein drugs at various steps of the manufacturing process (e.g. manufacturing raw materials, formulation, storage), and can cause a variety of modifications on the protein. These modifications can potentially influence the efficacy, safety, and stability of the therapeutic protein, especially if critical quality attributes (CQAs) are affected. Therefore, it is meaningful to understand the interactions between proteins and metals that can occur during the manufacturing process, formulation, and storage of biotherapeutics. Here, we describe a novel strategy to differentiate between ultra-trace levels of transition metals (cobalt, chromium, copper, iron, and nickel) interacting with therapeutic proteins and free metal in solution in the drug formulation using size exclusion chromatography coupled to inductively coupled plasma mass spectrometry (SEC-ICP-MS). Two monoclonal antibodies (mAbs) were coformulated and stored up to nine days in a scaled down model to mimic metal exposure from manufacturing tanks. The samples containing the mAbs were first analyzed by ICP-MS for bulk metal analysis, then studied using SEC-ICP-MS to measure the extent of metal-protein interactions. The SEC separation was used to differentiate metal associated with the mAbs from free metal in solution. Relative quantitation of metal-protein interaction was then calculated using the relative peak areas of protein-associated metal to free metal in solution and weighting it to the total metal concentration in the mixture as measured by bulk metal analysis by ICP-MS. The SEC-ICP-MS method offers an informative means of measuring metal-protein interactions during drug development.

Safety and tolerance of Lacticaseibacillus paracasei N1115 in caesarean-born young children: a randomised, placebo-controlled trial

The administration of probiotics may help to improve dysbiosis and related health problems in children delivered by caesarean section. However, the effects are strain specific, and safety combined tolerance are considered a priority. The aim of this study was to evaluate the safety and tolerance of Lacticaseibacillus paracasei N1115 in caesarean-born children aged 6-24 months via a randomised, placebo-controlled intervention study. In total, 101 children were included and randomised to receive either a sachet of L. paracasei N1115 (2×1010 cfu/g, 2 g/day) or placebo (maltodextrin, 2 g/day) per day for 12 weeks. Anthropometric parameters were measured by trained nurses, and defecation characteristics, gastrointestinal symptoms, (serious) adverse events ((s)AEs), crying patterns and lifestyle behaviours were recorded by parents or guardians. Neurocognitive development was assessed by the Ages and Stages Questionnaires-3 (ASQ-3) before and after the intervention. The only difference between groups regarding defecation characteristics was a significant treatment × time effect on stool frequency (P=0.007), as the number of defecations was significantly higher in the probiotic group (around 1.2-1.3 times/day) than in the placebo group (around 1.0 times/day) in the later intervention period (P=0.035 at week 9; P=0.048 at week 10; P=0.026 at week 12). The use of L. paracasei N1115 also reduced the incidence rate of constipation (Incidence rate ratio (IRR): 0.120; 95% confidence interval (CI): 0.015, 0.967; P=0.046) and abdominal pain (IRR: 0.562; 95% CI: 0.358, 0.882; P=0.012). Changes in anthropometric parameters, including weight, height and head circumference, did not differ significantly between groups, nor did measures of crying, sleep, outdoor activity, temper, appetite or the ASQ-3 scores. No adverse events associated with consumption of the probiotic were reported. Thus, the administration of L. paracasei N1115 is safe and well-tolerated in caesarean-born children aged 6-24 months. Furthermore, it may ameliorate gastrointestinal function to some extent.

Quantitative Collateral Assessment on CTP in the Prediction of Stroke Etiology

BACKGROUND AND PURPOSE

Patients with stroke etiology of large-artery atherosclerosis were thought to have better collateral circulation compared with patients with other stroke etiologies. We aimed to investigate the association between stroke etiology and collateral circulation with a new quantitative collateral assessment method.

MATERIALS AND METHODS

This retrospective study reviewed data from consecutive patients with proximal anterior artery occlusion who underwent CTP before reperfusion therapy. CBF maps were derived from CTP. A new indicator, maximum CBF of collateral vessels within the Sylvian fissure (cCBF_max), was applied to quantitatively assess the collateral status. The relationship between collateral status and stroke etiology was investigated.

RESULTS

A total of 296 patients were finally analyzed. The median cCBF_max was significantly higher in patients with large-artery atherosclerosis than in those without it (92 [interquartile range, 65-123] mL/100 g/min versus 62 [interquartile range, 46-82] mL/100 g/min; P < .001). Multivariable analysis revealed that a higher cCBF_max score was independently associated with large-artery atherosclerosis etiology (OR, 1.010; 95% CI, 1.002-1.018; P = .017) after adjustment. The area under the curve, sensitivity, and specificity of the final model in predicting the etiology of large-artery atherosclerosis were 0.870, 89.7%, and 75.2%, respectively.

CONCLUSIONS

Patients with large-artery atherosclerosis had a more adequate collateral perfusion supply with the new quantitative collateral assessment. The new quantitative collateral measurement might contribute to the prediction of stroke etiology in the acute clinical scenario for patients with acute ischemic stroke.

A chemoenzymatic strategy for site-selective functionalization of native peptides and proteins

The emergence of new therapeutic modalities requires complementary tools for their efficient syntheses. Availability of methodologies for site-selective modification of biomolecules remains a long-standing challenge, given the inherent complexity and the presence of repeating residues that bear functional groups with similar reactivity profiles. We describe a bioconjugation strategy for modification of native peptides relying on high site selectivity conveyed by enzymes. We engineered penicillin G acylases to distinguish among free amino moieties of insulin (two at amino termini and an internal lysine) and manipulate cleavable phenylacetamide groups in a programmable manner to form protected insulin derivatives. This enables selective and specific chemical ligation to synthesize homogeneous bioconjugates, improving yield and purity compared to the existing methods, and generally opens avenues in the functionalization of native proteins to access biological probes or drugs.

An Investigation of Instability in Dried Blood Spot Samples for Pharmacokinetic Sampling in Phase 3 Trials of Verubecestat

In-clinic dried blood spot (DBS) pharmacokinetic (PK) sampling was incorporated into two phase 3 studies of verubecestat for Alzheimer's disease (EPOCH [NCT01739348] and APECS [NCT01953601]), as a potential alternative to plasma PK sampling for improved logistical feasibility and decreased blood volume burden. However, an interim PK analysis revealed verubecestat concentrations in DBS samples declined with time to assay in both trials. An investigation revealed wide variation in implementation practices for DBS sample handling procedures resulting in insufficient desiccation which caused verubecestat instability. High-resolution mass spectrometry evaluations of stressed and aged verubecestat DBS samples revealed the presence of two hydrolysis degradants. To minimize instability, new DBS handling procedures were implemented that provided additional desiccant and minimized the time to analysis. Both verubecestat hydrolysis products were previously discovered and synthesized during active pharmaceutical ingredient stability characterization. A liquid chromatography-mass spectrometry assay to quantitate the dominant verubecestat degradant in DBS samples was developed and validated. The application of this method to stressed and aged verubecestat DBS samples confirmed that degradant concentrations accounted for the observed decreases in the verubecestat concentration. Furthermore, after increasing desiccant amounts, degradant concentrations accounted for approximately 7% of the verubecestat concentration in DBS clinical samples, indicating that issues with sample handling were minimized with new storage and shipping conditions. This case study illustrates the challenges with employing new sampling techniques in large, global trials, and the importance of anticipating and mitigating implementation risks.

Effects of various preservation treatments on diversity and abundance of microbial community in rice product (MiBa) during storage

To determine the most effective preservation method for MiBa (a traditional Chinese rice product), MiBa treated with 75% alcohol, 75% alcohol + inhibitor, ozone treatment; untreated (control); and raw rice were subjected to 16S rRNA gene and ITS three-generation sequencing by High-throughput Sequencing Technology. According to the results the preservation effects of different treatment methods ranked as follows: ozone treatment >75% alcohol treatment >75% alcohol+inhibitor > control. Bacterial composition analysis showed that the bacterial community on the surface of MiBa treated with ozone was dominated by genera Leuconostoc and Serratia. The fungal community consisted mainly of Aspergillus and Alternaria. In summary, ozone treatment proved to be the most effective in inhibiting microbial contamination during the storage of MiBa, effectively extending its shelf life.

Development of ProTx-II Analogues as Highly Selective Peptide Blockers of Nav1.7 for the Treatment of Pain

Inhibitor cystine knot peptides, derived from venom, have evolved to block ion channel function but are often toxic when dosed at pharmacologically relevant levels in vivo. The article describes the design of analogues of ProTx-II that safely display systemic in vivo blocking of Na_v1.7, resulting in a latency of response to thermal stimuli in rodents. The new designs achieve a better in vivo profile by improving ion channel selectivity and limiting the ability of the peptides to cause mast cell degranulation. The design rationale, structural modeling, in vitro profiles, and rat tail flick outcomes are disclosed and discussed.

Simultaneous multielement imaging of liver tissue using laser ablation inductively coupled plasma mass spectrometry

Analysis of the spatial distribution of metals, metalloids, and non-metals in biological tissues is of significant interest in the life sciences, helping to illuminate the function and roles these elements play within various biological pathways. Chemical imaging methods are commonly employed to address biological questions and reveal individual spatial distributions of analytes of interest. Elucidation of these spatial distributions can help determine key elemental and molecular information within the respective biological specimens. However, traditionally utilized imaging methods prove challenging for certain biological tissue analysis, especially with respect to applications that require high spatial resolution or depth profiling. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been shown to be effective for direct elemental analysis of solid materials with high levels of precision. In this work, chemical imaging using LA-ICP-MS has been applied as a powerful analytical methodology for the analysis of liver tissue samples. The proposed analytical methodology successfully produced both qualitative and quantitative information regarding specific elemental distributions within images of thin tissue sections with high levels of sensitivity and spatial resolution. The spatial resolution of the analytical methodology was innovatively enhanced, helping to broaden applicability of this technique to applications requiring significantly high spatial resolutions. This information can be used to further understand the role these elements play within biological systems and impacts dysregulation may have.

[MiR-671-5p negatively regulates SMAD3 to inhibit migration and invasion of osteosarcoma cells]

OBJECTIVE

To explore the role of miR-671-5p in regulating the migration and invasion of osteosarcoma and the underlying mechanisms.

METHODS

The differentially expressed microRNAs (miRNAs) in osteosarcoma were screened in the NCBI online database, and the target proteins of these miRNAs were predicted and their functions were analyzed. Osteosarcoma cells were transfected with a plasmid overexpressing miR-671-5p, and the transfection efficiency was assessed using quantitative real-time PCR (qRT-PCR). The changes in the migration and invasion of the transfected cells were examined with Transwell assay, and the expressions of proteins related with epithelial-mesenchymal transition (EMT) were detected using Western blotting. Dual-luciferase reporter assay was performed to determine whether the 3'UTR of SMAD3 contained a targeted binding site of miR-671-5p.

RESULTS

MiR-671-5p was significantly down-regulated in both osteosarcoma tissues and osteosarcoma cells (P < 0.05). The osteosarcoma cells overexpressing miR-671-5p showed significantly reduced migration and invasion abilities (P < 0.05) with obviously lowered expressions of EMT-related proteins (P < 0.05). SMAD3 was highly expressed in osteosarcoma cells (P < 0.05), and dual-luciferase reporter assay confirmed the presence of a targeted binding site between miR-671-5p and the 3'UTR of SMAD3 (P < 0.05). In osteosarcoma cells transfected with a SMAD3-overexpressing plasmid (P < 0.05), the high expression of SMAD3 significantly inhibited by miR-671-5p overexpression (P < 0.05). Transwell assay demonstrated that SMAD3 overexpression significantly promoted the migration and invasion of osteosarcoma cells (P < 0.05), and while miR-671-5p overexpression obviously reversed this effect (P < 0.05).

CONCLUSION

MiR-671-5p can inhibit the invasion and migration of osteosarcoma cells by negatively regulating SMAD3.

Immunotherapy combinations overcome resistance to bispecific T cell engager treatment in T cell-cold solid tumors

Therapeutic approaches are needed to promote T cell-mediated destruction of poorly immunogenic, "cold" tumors typically associated with minimal response to immune checkpoint blockade (ICB) therapy. Bispecific T cell engager (BiTE) molecules induce redirected lysis of cancer cells by polyclonal T cells and have demonstrated promising clinical activity against solid tumors in some patients. However, little is understood about the key factors that govern clinical responses to these therapies. Using an immunocompetent mouse model expressing a humanized CD3ε chain (huCD3e mice) and BiTE molecules directed against mouse CD19, mouse CLDN18.2, or human EPCAM antigens, we investigated the pharmacokinetic and pharmacodynamic parameters and immune correlates associated with BiTE efficacy across multiple syngeneic solid-tumor models. These studies demonstrated that pretreatment tumor-associated T cell density is a critical determinant of response to BiTE therapy, identified CD8⁺ T cells as important targets and mediators of BiTE activity, and revealed an antagonistic role for CD4⁺ T cells in BiTE efficacy. We also identified therapeutic combinations, including ICB and 4-1BB agonism, that synergized with BiTE treatment in poorly T cell-infiltrated, immunotherapy-refractory tumors. In these models, BiTE efficacy was dependent on local expansion of tumor-associated CD8⁺ T cells, rather than their recruitment from circulation. Our findings highlight the relative contributions of baseline T cell infiltration, local T cell proliferation, and peripheral T cell trafficking for BiTE molecule-mediated efficacy, identify combination strategies capable of overcoming resistance to BiTE therapy, and have clinical relevance for the development of BiTE and other T cell engager therapies.

Design and Study of PEG Linkers That Enable Robust Characterization of PEGylated Proteins

Several PEGylated therapeutic proteins are approved drugs, and more are under development. However, the synthesis and characterization of these bioconjugates, especially heterogeneous mixtures of PEGylated proteins, are challenging. The present study focuses on the development of PEG linkers that can be installed through biocatalytic route and render much simpler and insightful analytical characterization of PEG-protein conjugates. This linker enables traditional peptide mapping assay to determine protein sequence coverage, natural PTMs, and PEG attachment sites. Novel PEG linkers are cleavable during traditional sample preparation, leaving behind reporter amino acids to allow the determination of PEG attachment sites by peptide mapping. Products of transglutaminase-catalyzed bioconjugation of 5K PEG to Interferon α-2b were analyzed, and K31, K134, and K164 were identified as the PEGylation sites; the former two being newly determined sites demonstrates the sensitivity of the approach. In another instance, conjugation sites on Interleukin-2-PEG conjugation were found to be K31, K47, K48, and K75.

The HCN Channel Blocker ZD7288 Induces Emesis in the Least Shrew (Cryptotis parva)

Subtypes (1-4) of the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are widely expressed in the central and peripheral nervous systems, as well as the cells of smooth muscles in many organs. They mainly serve to regulate cellular excitability in these tissues. The HCN channel blocker ZD7288 has been shown to reduce apomorphine-induced conditioned taste aversion on saccharin preference in rats suggesting potential antinausea/antiemetic effects. Currently, in the least shew model of emesis we find that ZD7288 induces vomiting in a dose-dependent manner, with maximal efficacies of 100% at 1 mg/kg (i.p.) and 83.3% at 10 µg (i.c.v.). HCN channel subtype (1-4) expression was assessed using immunohistochemistry in the least shrew brainstem dorsal vagal complex (DVC) containing the emetic nuclei (area postrema (AP), nucleus tractus solitarius and dorsal motor nucleus of the vagus). Highly enriched HCN1 and HCN4 subtypes are present in the AP. A 1 mg/kg (i.p.) dose of ZD7288 strongly evoked c-Fos expression and ERK1/2 phosphorylation in the shrew brainstem DVC, but not in the in the enteric nervous system in the jejunum, suggesting a central contribution to the evoked vomiting. The ZD7288-evoked c-Fos expression exclusively occurred in tryptophan hydroxylase 2-positive serotonin neurons of the dorsal vagal complex, indicating activation of serotonin neurons may contribute to ZD7288-induced vomiting. To reveal its mechanism(s) of emetic action, we evaluated the efficacy of diverse antiemetics against ZD7288-evoked vomiting including the antagonists/inhibitors of: ERK1/2 (U0126), L-type Ca2+ channel (nifedipine); store-operated Ca2+ entry (MRS 1845); T-type Ca2+ channel (Z944), IP3R (2-APB), RyR receptor (dantrolene); the serotoninergic type 3 receptor (palonosetron); neurokinin 1 receptor (netupitant), dopamine type 2 receptor (sulpride), and the transient receptor potential vanilloid 1 receptor agonist, resiniferatoxin. All tested antiemetics except sulpride attenuated ZD7288-evoked vomiting to varying degrees. In sum, ZD7288 has emetic potential mainly via central mechanisms, a process which involves Ca2+ signaling and several emetic receptors. HCN channel blockers have been reported to have emetic potential in the clinic since they are currently used/investigated as therapeutic candidates for cancer therapy related- or unrelated-heart failure, pain, and cognitive impairment.

Determination of modification sites and relative quantitation in large protein conjugation via automated data processing

Protein conjugation is an effective way to impart different functionalities to the original protein. Conjugation using a native protein (a protein that does not contain special unnatural amino acid for conjugation) typically generates complex mixtures mainly due to the presence of multiple chemically similar competing conjugation sites. It is therefore a challenge to identify products, to optimize the reaction conditions, and to synthesize desired molecules. In order to guide this challenging process, quick and easy analytical methods are in great need for reaction monitoring. An analytical platform was developed for this purpose by using liquid chromatography/high resolution mass spectrometry (LC/HRMS) coupled with a custom-built software tool via Visual Basic for Applications in Excel (VBA). It allows for not only the determination of site-selective modification, but also the evaluation of the scope for possible modification sites. This vendor neutral VBA based software tool combined with enzymatic digestion, especially the SMART Digest™ method, and LC/HRMS would shorten the experimental time and data analysis from days to a few hours. Open-source VBA features a data fitting interface with the support for arbitrary functions and flexible global fits. Two conjugated proteins were used to demonstrate the capability of this VBA tool. Major conjugation sites are presented in a graphic format via its mass and ion intensity and chemists can visually estimate the ratio of modified vs unmodified proteins.

[MiR-300 inhibits invasion and metastasis of osteosarcoma cell MG63 by negatively regulating PTTG1]

OBJECTIVE

To investigate the effects of miR-300 and PTTG1 on osteosarcoma invasion and metastasis and explore the molecular mechanism of osteosarcoma invasion and metastasis.

OBJECTIVE

Western blot was used to detect the expression of PTTG1 in human osteoblasts hFOB1.19 and osteosarcoma cell MG63 and to detect the transfection efficiency of cells transfected with PTTG1-knockdown plasmid; Transwell invasion assay and CCK8 assay detected the effects of knockdown of PTTG1 and overexpression of miR-300 on the invasion and proliferation of osteosarcoma cell MG63. On-line prediction and screening of microRNAs (miRNAs) with complementary PTTG1 binding was conducted. qRT-PCR was performed to examine the expression of miR-300 in hFOB1.19 and MG63 cells, and Western blotting was used to detect the expression of PTTG1 in MG63 cells after transfection with a miR- 300 plasmid. Double luciferase assay was used to detect the targeted binding of miR-300 and PTTG, Transwell invasion assay and CCK8 assay were used to detect the effects of overexpression of miR-300 and overexpression of PTTG1 plasmid on invasion and proliferation of osteosarcoma cell line MG63.

OBJECTIVE

PTTG1 was highly expressed in MG63 cells (P=0.0002). PTTG1 knockdown significantly inhibited the invasion (P=0.0002) and proliferation (P=0.0039) of MG63 cells. Based on the results of online prediction of complementary miRNAs to PTTG1 and analysis of the data from NCBI database, miR-300 was determined as the target miRNA in this study. qRT-PCR results showed a significantly decreased expression of miR-300 in MG63 cells (P=0.0004). Overexpression of MiR-300 in MG63 cells significantly decreased the expression of PTTG1 (P=0.0007), and the expressions of miR-300 and PTTG1 were negatively correlated. Dual luciferase assay showed that miR-300 could specifically bind to PTTG1 (P=0.001). Overexpression of PTTG1 could significantly reverse the effect of miR-300 overexpression on invasion (P=0.0003) and proliferation (P=0.0077) of MG63 cells.

OBJECTIVE

Overexpression of miR-300 can inhibit the invasion and metastasis of osteosarcoma cell MG63 by targeting PTTG1.

Mapping Lipogenic Flux: A Gold LDI-MS Approach for Imaging Neutral Lipid Kinetics

Spatial characterization of triglyceride metabolism is an area of significant interest which can be enabled by mass spectrometry imaging via recent advances in neutral lipid laser desorption analytical approaches. Here, we extend recent advancements in gold-assisted neutral lipid imaging and demonstrate the potential to map lipid flux in rodents. We address here critical issues surrounding the analytical configuration and interpretation of the data for a group of select triglycerides. Specifically, we examined how the signal intensity and spatial resolution would impact the apparent isotope ratio in a given analyte (which is an important consideration when performing MS based kinetics studies of this kind) with attention given to molecular ions and not fragments. We evaluated the analytics by contrasting lipid flux in well characterized mouse models, including fed vs fed states and different dietary perturbations. In total, the experimental paradigm described here should enable studies of hepatic lipogenesis; presumably, this logic can be enhanced via the inclusion of ion mobility and/or fragmentation. Although this study was carried out in robust models of liver lipogenesis, we expect that the model system could be expanded to a variety of tissues where zonated (or heterogeneous) lipid synthesis may occur, including solid tumor metabolism.

Abstract 6714: Genetic screens identify T cell co-stimulation as a key modifier of the redirected cytotoxicity of bispecific T cell engager (BiTE®) molecules

BiTE® constructs redirect T cell cytotoxicity against cancer cells through simultaneous binding to CD3 on T cells and a tumor-associated antigen (TAA) on cancer cells. Blinatumomab, an anti-CD19 BiTE® molecule used to treat pre-B-ALL patients, leads to more than 40% complete remission rates. Only 30% of relapsed patients exhibit loss of CD19 on leukemia cells, indicating that the majority of patients acquire blinatumomab resistance independently of target loss. Understanding such mechanisms could lead to new predictive biomarkers and help improve current BiTE® immunotherapy.

To gain insight into the mechanism of resistance to BiTE® cytotoxicity, we performed CRISPR screens to identify tumor-intrinsic genetic factors that modulate BiTE® molecule efficacy in vitro. Cas9 expressing human cancer cells transduced with a genome-wide sgRNA library were incubated with T cells and either a control BiTE® molecule that did not recognize the cancer cells, or an anti-TAA BiTE® molecule at a concentration that induced the lysis of ~90% of target cells. Next-gen sequencing was used to identify enriched or depleted sgRNA, indicative of genes whose loss confers resistance or susceptibility to BiTE®-mediated T cell killing.

As expected, the most enriched candidates from the screen were involved in the expression, post-translational modification or surface presentation of the TAA targeted by the BiTE® molecules. In the case of a screen using an anti-MSLN BiTE® molecule, a panel of genes involved in GPI-anchor biosynthesis, required to anchor MSLN to the plasma membrane was uncovered. The screen also revealed genes known to promote immune evasion such as PD-L1 as well as novel genes whose roles in immunotherapy were not extensively studied before, including genes involved in apoptosis and the NF-κB pathway. One of the top enriched candidates was CD58, which encodes a co-stimulatory molecule that binds to CD2 on T cells. Genetic perturbation and pharmacological blockade of CD58-CD2 interaction significantly reduced BiTE®-mediated killing of target cells. Furthermore, re-establishment of CD58-CD2 interaction either by overexpressing CD58 in cancer cells or by using CD2-agonist large molecules improved T cell activation and target cell killing. Moreover, concurrent blocking of CD2 and CD28 co-stimulation inhibited BiTE®-mediated killing more profoundly than blocking either pathway alone, indicating redundancy between CD58- and CD80/86-mediated co-stimulation. Our study reveals an important role of T cell co-stimulatory signals in BiTE®-mediated cytotoxicity. Considering that loss of CD58 is highly prevalent in DLBCL and relapsed Hodgkin lymphoma patients, it could potentially serve as a biomarker to predict response to BiTE®-based therapies. Our study also demonstrates that restoring CD58-CD2 interaction could sensitize cancer cells to BiTE®-mediated killing.

Citation Format: Ye Shen, Patrick Collins, Jason Eng, Flordeliza Fajardo, Wendy Zhong, Olivier Nolan-Stevaux. Genetic screens identify T cell co-stimulation as a key modifier of the redirected cytotoxicity of bispecific T cell engager (BiTE®) molecules [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6714.

Combining MALDI mass spectrometry imaging and droplet-base surface sampling analysis for tissue distribution, metabolite profiling, and relative quantification of cyclic peptide melanotan II

Peptides have become a fast-growing segment of the pharmaceutical industry over the past few decades. It is essential to develop cutting edge analytical techniques to support the discovery and development of peptide therapeutics, especially to examine their absorption, distribution, metabolism and excretion (ADME) properties. Herein, we utilized two label-free mass spectrometry (MS) based techniques to investigate representative challenges in developing therapeutic peptides, such as tissue distribution, metabolic stability and clearance. A tool proof-of-concept cyclic peptide, melanotan II, was used in this study. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), which is a well-developed label-free imaging technique, was used to map the detailed molecular distribution of melanotan II and its metabolites. Droplet-based liquid microjunction surface sampling liquid chromatography-high resolution mass spectrometry (LMJ-SSP-LC-HRMS) was used in combination with MALDI-MSI to rapidly profile molecular information and provide structural insights on drug and metabolites. Using both techniques in parallel allowed a more comprehensive and complementary data set than using either technique independently. We envision MALDI-MSI and droplet-based LMJ-SSP-LC-HRMS, which can be used in combination or as standalone techniques, to become valuable tools for assessing the in vivo fate of peptide therapeutics in support of drug discovery and development.

Data on the comprehensive first-principles diffusion study of the aluminum-magnesium system

First-principles calculation of diffusion coefficients between Mg and Al is investigated comprehensively using density functional theory (DFT). The effect of different uncertainty sources arising from first principles calculations has been investigated systematically. These sources include the diffusion model, energetic, entropic and attempt frequency calculations. Variation in self and impurity diffusion coefficients of Mg and Al in stable phases are quantified using different DFT settings and compared with the experiments. Using the optimal DFT settings, diffusion coefficients in metastable phases of Al and Mg are predicted. The dataset refers to "An integrated experimental and computational study of diffusion and atomic mobility of the aluminum-magnesium system" [1].

Abstract PR12: Assessing in vivo mechanisms regulating the therapeutic activity of bi-specific T-cell engager (BiTE®) molecules in immunocompetent mice expressing a chimeric human/mouse CD3ϵ receptor

The development and success of Blincyto®, a Bi-Specific T cell Engager (BiTE®), to treat acute lymphoblastic leukemia has expanded the class of anticancer immunotherapy agents. BiTE® molecules consist of a single-chain Fc antibody containing tandem single-chain variable fragments (scFv) recognizing the CD3 receptor on T lymphocytes and a tumor-associated antigen and induce redirected T-cell cytotoxicity and tumor cell lysis. Despite the clinically validated efficacy of BiTE® molecules, there has been little elucidation of the parameters governing their in vivo activity. This is due, in part, to a lack of immunocompetent murine tumor models that allow for engagement of endogenous T cells in the context of an intact immune system, which more accurately mimic the human therapeutic setting. We have developed a genetically engineered mouse model (huCD3 mouse) in which a human/mouse chimeric CD3ϵ receptor recognized by BiTE® molecules was engineered into the mouse CD3ϵ genomic locus. Here, we characterize the immune cell distribution of the huCD3 mouse and utilize BiTE® molecules and syngeneic tumor models to elucidate pharmacokinetic, pharmacodynamic, and efficacy relationships in vivo. The peripheral B and T cell distribution profile of huCD3 mice and WT littermates are comparable, but T cells isolated from huCD3 mice express lower levels of. In T cell-dependent cytotoxic (TDCC) assays, an anti-huEpCAM BiTE® molecule exhibited similar potency against MC38 mouse cells expressing human EpCAM co-cultured with T cells from the huCD3 mice or a human donor, if mouse T-cells were preactivated in vitro. In vivo, MC38-huEpCAM tumors grew robustly and anti-huEpCAM BiTEÂ treatment resulted in dose-dependent tumor growth inhibition, with several tumor-free animals at higher doses. Flow cytometry analysis of disaggregated tumors and serum cytokine analysis indicated that BiTE® treatment resulted in T-cell activation and a cytokine response at doses that correlate with tumor regression. In vivo studies were also performed using B16F10-huEPCAM cells, which generate tumors with reduced T-cell infiltration compared to MC38-huEpCAM. Additionally, we used WT mice reconstituted with different ratios of huCD3e and WT bone marrow to investigate the T-cell number requirement for optimal BiTE®-mediated efficacy. We also evaluated the efficacy of an anti-mouse CD19 BiTE® molecule against MC38-CD19 tumor cells to compare the requirements for antitumor efficacy versus normal B-cell depletion in the blood and in lymphoid organs. Finally, we performed a rational combination study using BiTE® molecules and a PD1 inhibitor, demonstrating that this combination can lead to the eradication of poorly T cell-infiltrated solid tumors. These data begin to elucidate the in vivo mechanisms regulating the efficacy of BiTE® molecules under physiologically relevant conditions.

This abstract is also being presented as Poster A29.

Citation Format: Brian Belmontes, Hong Tan, Wendy Zhong, Danny Chui, Kevin Cook, Sarah O'Brien, Melissa Martin, Brandy Alexander, Jason Eng, John Harrold, Famke Aeffner, Matthew Chun, Alice Bakker, Mercedesz Balazs, Jason DeVoss, Angela Coxon, Jude Canon, Jackson Egen, Olivier Nolan-Stevaux. Assessing in vivo mechanisms regulating the therapeutic activity of bi-specific T-cell engager (BiTE®) molecules in immunocompetent mice expressing a chimeric human/mouse CD3ϵ receptor [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr PR12.

Estimation of the net energy and protein requirements for maintenance of male arctic foxes (Alopex lagopus) during the growth period1,2

The maintenance requirements of net energy and net protein were assumed to represent the most accurate and important values totally for the animal's utilization. The objective of this experiment was to determine the net energy and net protein requirements for maintenance of growing arctic foxes. The experiments was evaluated using regression models estimated from data collected by means of indirect calorimetry, nitrogen balance trials, and digestion and metabolism experiments. Thirty-six growing arctic foxes (3 487 ± 261.7 g) at the age of 85 days were randomly assigned to four groups with 9 animals in each group. Arctic foxes were fed a complete formula diet at four intake levels (100%, or 80%, 60%, and 40% of feed requirements) from 24 July 2017 to 23 September 2017. Arctic foxes in each treatment were kept individually in respiration chambers after 1-d adaptation at day 2 for a 3-d balance trial and then at day 5 followed by a 3-d fasting period. The metabolizable energy intake (MEI), heat production in the fed state (HP), and retained energy (RE) of arctic foxes significantly decreased (P < 0.01) as the feed intake level decreased. Fasting heat production (FHP) of arctic foxes was not influenced by feed intake level (P > 0.05). The metabolizable energy maintenance requirement (MEm) and net energy maintenance requirement (NEm) estimated from the linear relationship between RE and MEI were 230 and 217 kJ/kg of body weight BW0.75/d, respectively. The MEm and NEm estimated by logarithmic regression of HP on MEI were 225 and 209 kJ/kg BW0.75/d, respectively. The net N maintenance requirement (NNm) and net protein maintenance requirement (NPm) estimated from the linear relationship between retained nitrogen (RN) and daily nitrogen intake (NI) were 179.6 mg/kg BW0.75/d and 1.123 g/kg BW0.75/d, respectively. It is concluded that NEm and NPm values obtained fill the net energy and protein requirements shortage, and provide the basic data for establishing the standard of nutrition demand of breeding arctic foxes in China.