[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.

A dual diffusion model enables 3D molecule generation and lead optimization based on target pockets

Structure-based generative chemistry is essential in computer-aided drug discovery by exploring a vast chemical space to design ligands with high binding affinity for targets. However, traditional in silico methods are limited by computational inefficiency, while machine learning approaches face bottlenecks due to auto-regressive sampling. To address these concerns, we have developed a conditional deep generative model, PMDM, for 3D molecule generation fitting specified targets. PMDM consists of a conditional equivariant diffusion model with both local and global molecular dynamics, enabling PMDM to consider the conditioned protein information to generate molecules efficiently. The comprehensive experiments indicate that PMDM outperforms baseline models across multiple evaluation metrics. To evaluate the applications of PMDM under real drug design scenarios, we conduct lead compound optimization for SARS-CoV-2 main protease (Mpro) and Cyclin-dependent Kinase 2 (CDK2), respectively. The selected lead optimization molecules are synthesized and evaluated for their in-vitro activities against CDK2, displaying improved CDK2 activity.

Cryo-EM structures reveal two allosteric inhibition modes of PI3KαH1047R involving a re-shaping of the activation loop

PI3Kα is a lipid kinase that phosphorylates PIP2 and generates PIP3. The hyperactive PI3Kα mutation, H1047R, accounts for about 14% of breast cancer, making it a highly attractive target for drug discovery. Here, we report the cryo-EM structures of PI3KαH1047R bound to two different allosteric inhibitors QR-7909 and QR-8557 at a global resolution of 2.7 Å and 3.0 Å, respectively. The structures reveal two distinct binding pockets on the opposite sides of the activation loop. Structural and MD simulation analyses show that the allosteric binding of QR-7909 and QR-8557 inhibit PI3KαH1047R hyper-activity by reducing the fluctuation and mobility of the activation loop. Our work provides a strong rational basis for a further optimization and development of highly selective drug candidates to treat PI3KαH1047R-driven cancers.

Genome-wide analyses reveal the contribution of somatic variants to the immune landscape of multiple cancer types

It has been well established that cancer cells can evade immune surveillance by mutating themselves. Understanding genetic alterations in cancer cells that contribute to immune regulation could lead to better immunotherapy patient stratification and identification of novel immune-oncology (IO) targets. In this report, we describe our effort of genome-wide association analyses across 22 TCGA cancer types to explore the associations between genetic alterations in cancer cells and 74 immune traits. Results showed that the tumor microenvironment (TME) is shaped by different gene mutations in different cancer types. Out of the key genes that drive multiple immune traits, top hit KEAP1 in lung adenocarcinoma (LUAD) was selected for validation. It was found that KEAP1 mutations can explain more than 10% of the variance for multiple immune traits in LUAD. Using public scRNA-seq data, further analysis confirmed that KEAP1 mutations activate the NRF2 pathway and promote a suppressive TME. The activation of the NRF2 pathway is negatively correlated with lower T cell infiltration and higher T cell exhaustion. Meanwhile, several immune check point genes, such as CD274 (PD-L1), are highly expressed in NRF2-activated cancer cells. By integrating multiple RNA-seq data, a NRF2 gene signature was curated, which predicts anti-PD1 therapy response better than CD274 gene alone in a mixed cohort of different subtypes of non-small cell lung cancer (NSCLC) including LUAD, highlighting the important role of KEAP1-NRF2 axis in shaping the TME in NSCLC. Finally, a list of overexpressed ligands in NRF2 pathway activated cancer cells were identified and could potentially be targeted for TME remodeling in LUAD.

[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).

[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.

Abstract 477: Discovery of RGT-018: A potent, selective and orally bioavailable SOS1 inhibitor for mutant KRAS-driven cancers

Background: KRAS is the most frequently mutated oncogene with high prevalence in non-small cell lung cancers (NSCLC), colorectal cancers (CRC), and pancreatic cancers (PAC). FDA currently approved sotorasib provides breakthrough therapy for cancer patients with KRASG12C mutation, however there is still high unmet medical need for new agents that target a broader KRAS mutated tumors. A new opportunity emerges to develop a pan KRAS inhibitor by suppressing the upstream guanine nucleotide exchange factor (GEF) protein son of sevenless 1 (SOS1). SOS1 is a key activator of KRAS and facilitates the conversion of GDP-bound KRAS (off) state to GTP-bound KRAS (on) state. Binding to its catalytic domain, small molecule SOS1 inhibitor prevents KRAS activation and suppresses cancer cell proliferation.

Material and Methods: Regor’s unique Computer Accelerated Rational Design (CARD) technology platform was applied to identify potent and selective SOS1 inhibitors. Biochemical assays and cellular assays were utilized to drive the structure-activity relationship (SAR). In vitro and in vivo target engagement were confirmed. In vivo efficacy study data were generated using lung and pancreatic cancer xenograft mouse models with KRAS mutation.

Results: In vitro, RGT-018 blocked the interaction of KRAS::SOS1 with high selectivity, and inhibited proliferation of a broad spectrum of mutant KRAS-driven cancer cells as a single agent. Robust anti-proliferation activity was observed when RGT-018 was combined with MEK, KRASG12C, EGFR or CDK2/4/6 inhibitors in vitro. Oral administration of RGT-018 inhibited tumor growth and suppressed KRAS signaling pathway activation in tumor xenografts. Furthermore, combination with MEK or KRASG12C inhibitors led to profound tumor regression.

Conclusions: The pharmacological properties of RGT-018 represent an attractive drug candidate with oral bioavailability for combination with targeted agents to treat a broader patient population driven by mutant KRAS.

Citation Format: Fei Xiao, Kailiang Wang, Xinjuan Wang, Huijuan Li, Zhilong Hu, Wei Huang, Xiaoming Ren, Teng Feng, Lili Yao, Jing Lin, Chunlai Li, Liufeng Mei, Zhuanzhuan Zhang, Yangyang Liu, Xi Chen, Xiaotian Zhu, Wenge Zhong, Zhi Xie. Discovery of RGT-018: A potent, selective and orally bioavailable SOS1 inhibitor for mutant KRAS-driven cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 477.

Accelerated Discovery of Macrocyclic CDK2 Inhibitor QR-6401 by Generative Models and Structure-Based Drug Design

Selective CDK2 inhibitors have the potential to provide effective therapeutics for CDK2-dependent cancers and for combating drug resistance due to high cyclin E1 (CCNE1) expression intrinsically or CCNE1 amplification induced by treatment of CDK4/6 inhibitors. Generative models that take advantage of deep learning are being increasingly integrated into early drug discovery for hit identification and lead optimization. Here we report the discovery of a highly potent and selective macrocyclic CDK2 inhibitor QR-6401 (23) accelerated by the application of generative models and structure-based drug design (SBDD). QR-6401 (23) demonstrated robust antitumor efficacy in an OVCAR3 ovarian cancer xenograft model via oral administration.

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.

Structural insights into ligand recognition and selectivity of somatostatin receptors

Somatostatin receptors (SSTRs) play versatile roles in inhibiting the secretion of multiple hormones such as growth hormone and thyroid-stimulating hormone, and thus are considered as targets for treating multiple tumors. Despite great progress made in therapeutic development against this diverse receptor family, drugs that target SSTRs still show limited efficacy with preferential binding affinity and conspicuous side-effects. Here, we report five structures of SSTR2 and SSTR4 in different states, including two crystal structures of SSTR2 in complex with a selective peptide antagonist and a non-peptide agonist, respectively, a cryo-electron microscopy (cryo-EM) structure of G_i1-bound SSTR2 in the presence of the endogenous ligand SST-14, as well as two cryo-EM structures of G_i1-bound SSTR4 in complex with SST-14 and a small-molecule agonist J-2156, respectively. By comparison of the SSTR structures in different states, molecular mechanisms of agonism and antagonism were illustrated. Together with computational and functional analyses, the key determinants responsible for ligand recognition and selectivity of different SSTR subtypes and multiform binding modes of peptide and non-peptide ligands were identified. Insights gained in this study will help uncover ligand selectivity of various SSTRs and accelerate the development of new molecules with better efficacy by targeting SSTRs.

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.

Highly Efficient Ruthenium-Catalyzed Asymmetric Hydrogenation of N-Heteroaryl Vinyl Ethers

Highly efficient N-heteroaryl-directed Ru-catalyzed asymmetric hydrogenation of α,α-disubstituted vinyl ethers is successfully achieved by using commercially available ligand (R/S)-RuCl[(p-cymene)(BINAP)]Cl. Hundred-gram scale-up of 6b has been successfully completed with consistent ee...

Abstract P241: A highly potent HPK1 inhibitor augments immune cell activation and anti-tumor immunity in a syngeneic tumor mouse model

Background: HPK1 (MAP4K1) is a serine/threonine Ste20-related protein kinase that belongs to the mitogen-activated protein kinase (MAPK) family. HPK1 is mainly expressed in hematopoietic cells and serves as a negative regulator of anti-tumor immunity through modulating the activation of lymphocytes and dendritic cells. Upon TCR activation, HPK1 phosphorylates the adaptor protein SLP76 at Ser376 to destabilize the SLP76 microclusters, which leads to the attenuation of the TCR signaling. The reported anti-tumor efficacy data from HPK1 knockout and kinase-dead knock-in mouse models support HPK1 as a novel intracellular I/O target. Methods: Regor CARD platform (Computer Accelerated Rational Discovery) was deployed to identify potent and selective inhibitors of HPK1. Biochemical assays and primary human pan T cell-based cellular assays were utilized to support the structure-activity relationship (SAR) analysis and inhibitor optimization. In vitro and in vivo target engagement studies were conducted in Jurkat T cells and mouse splenocytes, respectively. In vivo efficacy study data were generated using CT-26 syngeneic tumor mouse model. Results: Highly potent HPK1 inhibitors with good selectivity against the liable immune kinases were identified. RGT-197, one of the lead inhibitors demonstrated a significant increase of IL-2 secretion in primary human pan T cells upon TCR activation. It inhibited TCR-induced phosphorylation of SLP76 at Ser-376 in vitro and in vivo. Anti-tumor efficacy was observed in CT-26 tumor-bearing mice by oral dosing of RGT-197 as a single agent and in combination with an anti-PD1-monoclonal antibody. Furthermore, RGT-197 increased the level of cytokines important for anti-tumor immunity in vivo. Conclusion: RGT-197, a potent and selective HPK1 inhibitor, provides a potential opportunity as a small molecule I/O agent to boost anti-tumor immunity either as monotherapy or in combination with immune checkpoint inhibitors.

Citation Format: Hao Liu, Lei Wu, Song Feng, Wei Huang, Huijuan Li, Jing Lin, Yangyang Liu, Liufeng Mei, Baoqi Ren, Julie Xie, Lili Yao, Wenge Zhong. A highly potent HPK1 inhibitor augments immune cell activation and anti-tumor immunity in a syngeneic tumor mouse model [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P241.

[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.

Molecular insights into ago-allosteric modulation of the human glucagon-like peptide-1 receptor

The glucagon-like peptide-1 (GLP-1) receptor is a validated drug target for metabolic disorders. Ago-allosteric modulators are capable of acting both as agonists on their own and as efficacy enhancers of orthosteric ligands. However, the molecular details of ago-allosterism remain elusive. Here, we report three cryo-electron microscopy structures of GLP-1R bound to (i) compound 2 (an ago-allosteric modulator); (ii) compound 2 and GLP-1; and (iii) compound 2 and LY3502970 (a small molecule agonist), all in complex with heterotrimeric G_s. The structures reveal that compound 2 is covalently bonded to C347 at the cytoplasmic end of TM6 and triggers its outward movement in cooperation with the ECD whose N terminus penetrates into the GLP-1 binding site. This allows compound 2 to execute positive allosteric modulation through enhancement of both agonist binding and G protein coupling. Our findings offer insights into the structural basis of ago-allosterism at GLP-1R and may aid the design of better therapeutics.

The glucagon-like peptide-1 (GLP-1) receptor is a key regulator of glucose homeostasis and a drug target for type 2 diabetes but available GLP-1R agonists are suboptimal due to several side-effects. Here authors report the cryo-EM structure of GLP-1R bound to an ago-allosteric modulator in complex with heterotrimeric G_s which offers insights into the molecular details of ago-allosterism.

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.

[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.

Abstract PS16-22: Targeting resistance to current CDK4/6 therapies by RGT-419B, an inhibitor with optimized kinase activity spectrum

Cyclin-dependent kinases (CDKs) 4/6 inhibitors are a powerful class of therapeutic drugs for the treatment of advanced metastatic breast cancer. However, the currently approved CDK4/6 inhibitors palbociclib, ribociclib and abemaciclib have dose-limiting toxicities that require treatment holidays or reductions to sub-optimal doses, thus limiting full target inhibition. The residual CDK4/6 activity, together with persistent signaling through CDK2/cyclin E are among key resistant mechanisms that can compromise full clinical benefit. RGT-419B is a 3rd generation CDK inhibitor with an optimized kinase activity spectrum that has been discovered employing a Computer Accelerated Rational Design technology platform. RGT-419B has potent sub-nM CDK4 activity with desired degrees of selectivity against kinases such as CDK6, CDK9 and GSK3β to enable full target engagement with an improved safety profile. Furthermore, single digit nM CDK2 kinase activity has been incorporated into the design of RGT-419B to combat Cyclin E/CDK2-driven resistance. In vitro, RGT-419B showed more robust activity against palbociclib-resistant ER+ breast cancer cells than abemaciclib. In ER+ T47D breast cancer cells with overexpression of Cyclin E1, RGT-419B exhibited better antiproliferation activity than either abemaciclib or palbociclib. RGT-419B also demonstrated more durable in vivo tumor growth inhibition when compared with abemaciclib in an ER+ breast cancer xenograft model. The optimized kinase activity spectrum of RGT-419B provides an opportunity to treat ER+ breast cancer patients refractory to the existing CDK4/6 inhibitors, as either a single agent or in combination with other therapies.

Citation Format: Zhi Xie, Jing Han, Zhilong Hu, Hu He, Xianqiang Sun, Fei Zhang, Jing Lin, Lili Yao, Xinjuan Wang, Liufeng Mei, Yangyang Liu, Guoyun Zhu, Xi Chen, Xiaotian Zhu, Wenge Zhong. Targeting resistance to current CDK4/6 therapies by RGT-419B, an inhibitor with optimized kinase activity spectrum [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS16-22.

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].

Author Correction: Cryo-EM structures of PAC1 receptor reveal ligand binding mechanism

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Cryo-EM structures of PAC1 receptor reveal ligand binding mechanism

The pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1R) belongs to the secretin receptor family and is widely distributed in the central neural system and peripheral organs. Abnormal activation of the receptor mediates trigeminovascular activation and sensitization, which is highly related to migraine, making PAC1R a potential therapeutic target. Elucidation of PAC1R activation mechanism would benefit discovery of therapeutic drugs for neuronal disorders. PAC1R activity is governed by pituitary adenylate cyclase-activating polypeptide (PACAP), known as a major vasodilator neuropeptide, and maxadilan, a native peptide from the sand fly, which is also capable of activating the receptor with similar potency. These peptide ligands have divergent sequences yet initiate convergent PAC1R activity. It is of interest to understand the mechanism of PAC1R ligand recognition and receptor activity regulation through structural biology. Here we report two near-atomic resolution cryo-EM structures of PAC1R activated by PACAP38 or maxadilan, providing structural insights into two distinct ligand binding modes. The structures illustrate flexibility of the extracellular domain (ECD) for ligands with distinct conformations, where ECD accommodates ligands in different orientations while extracellular loop 1 (ECL1) protrudes to further anchor the ligand bound in the orthosteric site. By structure-guided molecular modeling and mutagenesis, we tested residues in the ligand-binding pockets and identified clusters of residues that are critical for receptor activity. The structures reported here for the first time elucidate the mechanism of specificity and flexibility of ligand recognition and binding for PAC1R, and provide insights toward the design of therapeutic molecules targeting PAC1R.

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.

Structure-guided discovery of a single-domain antibody agonist against human apelin receptor

Developing antibody agonists targeting the human apelin receptor (APJ) is a promising therapeutic approach for the treatment of chronic heart failure. Here, we report the structure-guided discovery of a single-domain antibody (sdAb) agonist JN241-9, based on the cocrystal structure of APJ with an sdAb antagonist JN241, the first cocrystal structure of a class A G protein-coupled receptor (GPCR) with a functional antibody. As revealed by the structure, JN241 binds to the extracellular side of APJ, makes critical contacts with the second extracellular loop, and inserts the CDR3 into the ligand-binding pocket. We converted JN241 into a full agonist JN241-9 by inserting a tyrosine into the CDR3. Modeling and molecular dynamics simulation shed light on JN241-9-stimulated receptor activation, providing structural insights for finding agonistic antibodies against class A GPCRs.

The pivotal role of glycogen synthase kinase 3 (GSK-3) in vomiting evoked by specific emetogens in the least shrew (Cryptotis parva)

Glycogen synthase kinase 3 (GSK-3) is a constitutively active multifunctional serine-threonine kinase which is involved in diverse physiological processes. GSK-3 has been implicated in a wide range of diseases including neurodegeneration, inflammation, diabetes and cancer. GSK-3 is a downstream target for protein kinase B (Akt) which phosphorylates GSK-3 and suppresses its activity. Based upon our preliminary findings, we postulated Akt's involvement in emesis. The aim of this study was to investigate the participation of GSK-3 and the antiemetic potential of two GSK-3 inhibitors (AR-A014418 and SB216763) in the least shrew model of vomiting against fully-effective emetic doses of diverse emetogens, including the nonselective and/or selective agonists of serotonin type 3 (e.g. 5-HT or 2-Methyl-5-HT)-, neurokinin type 1 receptor (e.g. GR73632), dopamine D₂ (e.g. apomorphine or quinpirole)-, and muscarinic 1 (e.g. pilocarpine or McN-A-343) receptors, as well as the L-type Ca²⁺ channel agonist (FPL64176), the sarco/endoplasmic reticulum Ca²⁺-ATPase inhibitor thapsigargin, and the chemotherapeutic agent, cisplatin. We first determined if these emetogens could regulate the phosphorylation level of GSK-3 in the brainstem emetic loci of least shrews and then investigated whether AR-A014418 and SB216763 could protect against the evoked emesis. Phospho-GSK-3α/β Ser21/9 levels in the brainstem and the enteric nerves of jejunum in the small intestine were upregulated following intraperitoneal (i.p.) administration of all the tested emetogens. Furthermore, administration of AR-A014418 (2.5-20 mg/kg, i.p.) dose-dependently attenuated both the frequency and percentage of shrews vomiting in response to i.p. administration of 5-HT (5 mg/kg), 2-Methyl-5-HT (5 mg/kg), GR73632 (5 mg/kg), apomorphine (2 mg/kg), quinpirole (2 mg/kg), pilocarpine (2 mg/kg), McN-A-343 (2 mg/kg), FPL64176 (10 mg/kg), or thapsigargin (0.5 mg/kg). Relatively lower doses of SB216763 exerted antiemetic efficacy, but both inhibitors barely affected cisplatin (10 mg/kg)-induced vomiting. Collectively, these results support the notion that vomiting is accompanied by a downregulation of GSK-3 activity and pharmacological inhibition of GSK-3 protects against pharmacologically evoked vomiting.

Fragment-Based Computational Method for Designing GPCR Ligands

G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors, which is arguably the most important family of drug target. With the technology breakthroughs in X-ray crystallography and cryo-electron microscopy, more than 300 GPCR-ligand complex structures have been publicly reported since 2007, covering about 60 unique GPCRs. Such abundant structural information certainly will facilitate the structure-based drug design by targeting GPCRs. In this study, we have developed a fragment-based computational method for designing novel GPCR ligands. We first extracted the characteristic interaction patterns (CIPs) on the binding interfaces between GPCRs and their ligands. The CIPs were used as queries to search the chemical fragments derived from GPCR ligands, which were required to form similar interaction patterns with GPCR. Then, the selected chemical fragments were assembled into complete molecules by using the AutoT&T2 software. In this work, we chose β-adrenergic receptor (β-AR) and muscarinic acetylcholine receptor (mAChR) as the targets to validate this method. Based on the designs suggested by our method, samples of 63 compounds were purchased and tested in a cell-based functional assay. A total of 15 and 22 compounds were identified as active antagonists for β₂-AR and mAChR M1, respectively. Molecular dynamics simulations and binding free energy analysis were performed to explore the key interactions (e.g., hydrogen bonds and π-π interactions) between those active compounds and their target GPCRs. In summary, our work presents a useful approach to the de novo design of GPCR ligands based on the relevant 3D structural information.