Multiplexed experimental strategies for fragment library screening against challenging drug targets using SPR biosensors.

Surface plasmon resonance (SPR) biosensor methods are ideally suited for fragment-based lead discovery.  However, generally applicable experimental procedures and detailed protocols are lacking, especially for structurally or physico-chemically challenging targets or when tool compounds are not available. Success depends on accounting for the features of both the target and the chemical library, purposely designing screening experiments for identification and validation of hits with desired specificity and mode-of-action, and availability of orthogonal methods capable of confirming fragment hits. The range of targets and libraries amenable to an SPR biosensor-based approach for identifying hits is considerably expanded by adopting multiplexed strategies, using multiple complementary surfaces or experimental conditions. Here we illustrate principles and multiplexed approaches for using flow-based SPR biosensor systems for screening fragment libraries of different sizes (90 and 1056 compounds) against a selection of challenging targets. It shows strategies for the identification of fragments interacting with 1) large and structurally dynamic targets, represented by acetyl choline binding protein (AChBP), a Cys-loop receptor ligand gated ion channel homologue, 2) targets in multi protein complexes, represented by lysine demethylase 1 and a corepressor (LSD1/CoREST), 3) structurally variable or unstable targets, represented by farnesyl pyrophosphate synthase (FPPS), 4) targets containing intrinsically disordered regions, represented by protein tyrosine phosphatase 1B  (PTP1B), and 5) aggregation-prone proteins, represented by an engineered form of human tau  (tau K18M). Practical considerations and procedures accounting for the characteristics of the proteins and libraries, and that increase robustness, sensitivity, throughput and versatility are highlighted. The study shows that the challenges for addressing these types of targets is not identification of potentially useful fragments per se, but establishing methods for their validation and evolution into leads.

DaBlaCa-13 Study: Oncological Outcome of Short-Term, Intensive Chemoresection With Mitomycin in Nonmuscle Invasive Bladder Cancer: Primary Outcome of a Randomized Controlled Trial.

PURPOSE: This study aimed to assess long-term follow-up after chemoresection with mitomycin (MMC), a nonsurgical treatment modality for recurrent nonmuscle invasive bladder cancer (NMIBC). At the time of recurrence, chemoresection has previously been shown to reduce the number of patients requiring a procedure (transurethral resection of bladder tumors [TURBT] or office biopsy) by more than 50%. This study investigated the number of patients requiring a procedure during initial treatment and 2-year follow-up in patients treated with short-term, intensive chemoresection with MMC compared with patients undergoing standard surgical treatment of recurrent NMIBC. METHODS: A randomized, controlled trial was conducted in two urological departments in Denmark from January 2018 to August 2021. In total, 120 patients with a history of Ta low- or high-grade NMIBC were included upon recurrence. The intervention group received intravesical MMC (40 mg/40 mL) three times a week for 2 weeks and TURBT or office biopsy only if the response was incomplete. The control group received TURBT or office biopsy and 6 weekly adjuvant instillations. The primary outcome was the number of patients undergoing a procedure within 2 years from inclusion, which was compared between groups using the chi-squared test. Recurrence-free survival was analyzed using the Kaplan-Meier method. RESULTS: Significantly fewer patients were in need of a procedure in the intervention group than in the control group: 71% (95% CI, 57 to 81) and 100% (95% CI, 94 to 100), P < .001. The 12-month recurrence-free survival was 36% (95% CI, 24 to 50) and 43% (95% CI, 30 to 56) in the intervention and control groups, respectively (P = .5). CONCLUSION: Short-term intensive chemoresection is an effective treatment strategy for recurrent NMIBC that leads to a reduced number of required procedures without compromising long-term oncological safety.

The transferability of the minimal invasive surgeon's skills to open surgery.

BACKGROUND: Robot-assisted laparoscopic surgery has gained popularity, which has contributed to a decrease in the number of open procedures. Hence a growing concern regarding the ability of laparoscopically trained surgeons to perform open surgery (e.g. due to bleeding complications) has been raised. The aim of the study was to investigate the ability of conversion to open surgery following exclusively robotic or laparoscopic training. METHODS: Thirty-six medical students were randomized into three groups: Open surgery, laparoscopy, and robot-assisted laparoscopy. All underwent intensive simulation training in the allocated surgical modality. Subsequently, all study subjects performed an open bowel anastomosis in a pig model where anastomoses were tested for resistance to pressure and leak as a surrogate marker of surgical quality. RESULTS: The primary endpoint was the surgical quality of an open surgery model assessed as, leak pressure, which was 80.01 ± 36.16 mmHg in the laparoscopic training group, 106.57 ± 23.03 mmHg in the robotic training group, and 133.65 ± 18.32 mmHg in the open surgery training group (mean, SD). We found that there were no significant differences between the open surgery training group and the robotic training group whereas a significant difference was found when comparing laparoscopic and open surgery training groups in favor of open procedure training (p < 0.001). CONCLUSION: In a surrogate open surgery model based on bowel anastomosis, we found that skills acquired through practice on robotic simulation platforms were not significantly worse when compared to skills acquired through training in open surgery, whereas skills acquired from laparoscopic training were significantly poorer when compared to open surgery practice.

Engineered mesoporous silica reduces long-term blood glucose, HbA1c, and improves metabolic parameters in prediabetics.

Aim: To investigate the effect of oral consumption of engineered mesoporous silica particles, SiPore15®, on long-term blood glucose levels and other metabolic parameters in individuals with prediabetes and newly diagnosed Type 2 diabetes. Method: An open-label, single-arm, multicenter trial was conducted in which SiPore15 was consumed three times daily for 12 weeks. Hemoglobin A1c (HbA1c, primary end point) and an array of metabolic parameters were measured at baseline and throughout the trial. Result: SiPore15 treatment significantly reduced HbA1c by a clinically meaningful degree and improved several disease-associated parameters with minimal side effects. Conclusion: The results from this study demonstrate the potential use of SiPore15 as a treatment for prediabetes that may also delay or prevent the onset of Type 2 diabetes.

Lay abstract Prediabetes is a health condition in which blood sugar levels are higher than normal but below diabetes diagnosis level. Without intervention, prediabetic adults and children are most likely to progress to Type 2 diabetes. To try and prevent this progression, the authors of this article are proposing an innovative solution with an engineered material called SiPore15^®. SiPore15 is classified as a medical device, and is made up entirely of porous silica particles. It has been proven to be safe to take orally. The effects of SiPore15 were investigated in people with prediabetes and newly diagnosed Type 2 diabetes. SiPore15 was taken three times a day for 12 weeks. It significantly reduced long-term blood glucose levels and improved other factors related to the disease with minimal side effects. The results from this study show that SiPore15 has the potential to be used as a treatment for prediabetes. This may help to delay or prevent the onset of Type 2 diabetes. Clinical Trial Registration: NCT03823027 (ClinicalTrials.gov).

SPTAN1, APC, and FGFR3 Mutation Status and APOBEC Mutation Signatures are Predictive of Mitomycin C Response in Non-muscle-invasive Bladder Cancer.

BACKGROUND: Currently, no biomarkers of response to mitomycin C have been identified in non-muscle-invasive bladder cancer patients. Predictive biomarkers could improve the treatment outcome and eliminate adverse events from unnecessary treatment. OBJECTIVE: To identify and validate predictive biomarkers of chemoresection with mitomycin C. DESIGN SETTING AND PARTICIPANTS: The intervention group of a randomised controlled trial was identified for analyses. The study was conducted between January 2018 and June 2019 in two major urological departments in Denmark. Patients had a history of Ta low-grade/high-grade disease and were included upon recurrence. The intervention group (58 patients) received chemoresection with mitomycin C. Tumour and reference germline DNA from prior tumours were analysed by whole exome sequencing. Predictive biomarkers were validated in the context of Ta low-grade tumours from the UROMOL study. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Response to chemotherapy (intervention group from the randomised controlled trial) and recurrence-free survival (UROMOL cohort) were measured. Groups were compared using Fisher's exact test and Wilcoxon rank sum test. RESULTS AND LIMITATIONS: Chemoresponse was associated with the mutation status of SPTAN1, APC, and FGFR3, and the level of APOBEC signature contribution (p = 0.035, p = 0.034, p = 0.055, and p = 0.035, respectively). The main limitations include no biopsy for biomarker discovery immediately prior to chemoresection and the unmatched validation cohort. CONCLUSIONS: Mutation status of APC, SPTAN1, and FGFR3 and the level of mutational contribution from APOBEC-related signatures were identified as potential predictive biomarkers for chemoresection with mitomycin C in non-muscle-invasive bladder cancer patients. A prospective validation study is however needed. PATIENT SUMMARY: We investigated DNA from noninvasive bladder tumours in order to predict treatment response to chemotherapy. Four biomarkers showed promising results, which should be tested in future studies.

Adverse events of hyperthermic intravesical chemotherapy for non-muscle invasive bladder cancer patients.

INTRODUCTION: Non-muscle invasive bladder cancer (NMIBC) is one of the most frequent neoplasms in Denmark. Treatment of high-risk NMIBC usually consists of transurethral resection of bladder (TUR-B) followed by intravesical Bacillus Calmette-Guérin (BCG) instillations. Unfortunately, some patients are BCG-unresponsive and will relapse over time. Radical cystectomy is the recommended salvage treatment following BCG-failure or BCG-intolerance. However, not all patients are candidates for surgery and thus, in need of other treatment. This study investigates the adverse events of Hyperthermic Intravesical Chemotherapy (HIVEC) treatment. METHODS: Twenty-three high-risk NMIBC patients, who were BCG-unresponsive or had contraindications for BCG, received HIVEC with Mitomycin C. Prior to each instillation, patients were interviewed by a nurse, using a systematic questionnaire regarding the adverse events. Patients were followed with cytology and cystoscopy every fourth month. The primary outcome was adverse event related to the HIVEC treatment. RESULTS: In general, the adverse events were mild to moderate and often self-limiting. The most common adverse events were urinary frequency (23.6%), incontinence (19.4%) and urinary tract pain (12.2%). CONCLUSION: In the current study, we found that HIVEC was a well-tolerated treatment. HIVEC might be a feasible option for patients, who experienced BCG-failure or BCG-intolerance and could potentially postpone or avoid radical cystectomy.

Oral intake of mesoporous silica is safe and well tolerated in male humans.

BACKGROUND: Precisely engineered mesoporous silica has been shown to induce weight loss in mice, but whether it is safe to use in humans have not investigated. OBJECTIVE: The aim was to determine whether oral dosing, up to 9 grams/day, of precisely engineered mesoporous silica as a food additive can be used safely in male humans. DESIGN: This single blinded safety study consisted of two study arms including 10 males each (18-35 years). One arm consisted of participants with normal weight and one with obesity. After a placebo run-in period, all subjects were given porous silica three times daily, with increasing dose up to 9 grams/day (Phase 1). Subjects with obesity continued the study with highest dose for additional 10 weeks (Phase 2). RESULTS: All participants completed Phase 1 and 90% completed Phase 2, with approximately 1% missed doses. Participants reported no abdominal discomfort, and changes in bowel habits were minor and inconsistent. The side effects observed were mild and tolerable, biomarkers did not give any safety concern, and no severe adverse events occurred. CONCLUSION: Mesoporous silica intake of up to 9 grams/day can be consumed by males without any major adverse events or safety concerns.

The DaBlaCa-13 Study: Short-term, Intensive Chemoresection Versus Standard Adjuvant Intravesical Instillations in Non-muscle-invasive Bladder Cancer-A Randomised Controlled Trial.

BACKGROUND: Instillation therapy for non-muscle-invasive bladder cancer (NMIBC) reduces recurrences but is associated with side effects. Preoperative instillation of chemotherapy could potentially be associated with fewer side effects compared with adjuvant instillations and in some patients make tumour resection (transurethral resection of the bladder tumour [TURBT]) superfluous. OBJECTIVE: To investigate tumour response and adverse events related to short-term, intensive chemoresection with mitomycin C compared with adjuvant instillations in patients with recurrent NMIBC. DESIGN, SETTING, AND PARTICIPANTS: A randomised, controlled trial was conducted in two urological departments in Denmark from January 2018 to June 2019. In total, 120 participants with a history of Ta bladder tumours, low grade or high grade, were included upon recurrence. INTERVENTION: Intravesical mitomycin C (40 mg/40 ml) three times a week for 2 wk in the intervention group (59 patients) was compared with TURBT and six weekly adjuvant instillations in the control group (61 patients). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Tumour response was evaluated in the intervention group by flexible cystoscopy after 4 wk. Side effects were prospectively registered in both groups using the National Cancer Institute's Common Terminology Criteria for Adverse Events. Groups were compared using χ2 or Fisher's exact test. RESULTS AND LIMITATIONS: Complete tumour response was seen in 33 participants (57%) in the intervention group. Fewer adverse events were reported in the intervention group than in the control group. Two patients in each group ceased instillation treatment due to adverse events. The main limitation is the current lack of long-term follow-up. CONCLUSIONS: Short-term, intensive chemoresection yields a tumour response of 57%. Hence, only half of those treated with chemoresection needed TURBT. The treatment was furthermore associated with fewer clinically significant side effects. Owing to small numbers, further investigations on Ta high-grade tumours are needed. PATIENT SUMMARY: We compared a nonsurgical treatment with standard treatment in patients with superficial bladder tumours. We found it to be safe and able to avoid surgery in more than half of the patients.

Entrapping Digestive Enzymes with Engineered Mesoporous Silica Particles Reduces Metabolic Risk Factors in Humans.

Engineered mesoporous silica particles (MSP) are thermally and chemically stable porous materials composed of pure silica and have attracted attention for their potential biomedical applications. Oral intake of engineered MSP is shown to reduce body weight and adipose tissue in mice. Here, clinical data from a first-in-humans study in ten healthy individuals with obesity are reported, demonstrating a reduction in glycated hemoglobin (HbA1c) and low-density lipoprotein cholesterol, which are well-established metabolic and cardiovascular risk factors. In vitro investigations demonstrate sequestration of pancreatic  α-amylase and lipase in an MSP pore-size dependent manner. Subsequent ex vivo experiments in conditions mimicking intestinal conditions and in vivo experiments in mice show a decrease in enzyme activity upon exposure to the engineered MSP, presumably by the same mechanism. Therefore, it is suggested that tailored MSP act by lowering the digestive enzyme availability in the small intestine, resulting in decreased digestion of macronutrient and leading to reduced caloric uptake. This novel MSP based mechanism-of-action, combined with its excellent safety in man, makes it a promising future agent for prevention and treatment of metabolic diseases.

Mesoporous silica with precisely controlled pores reduces food efficiency and suppresses weight gain in mice.

Aim: Obesity is a risk factor for cardiovascular disease and diabetes. We aimed to elucidate the effects of distinct mesoporous silica particles (MSPs) supplemented in food on metabolic parameters in obesity. Materials & methods: MSPs with precisely controlled pore size were synthesized, characterized and compared with a control in a C57Bl/6 mouse diet-induced obesity model, studying weight, adiposity, metabolic regulation and food efficiency. Results: The most effective MSPs reduced adipose tissue formation to 6.5 ± 0.5 g compared with 9.4 ± 1.2 g, leptin levels nearly halved from 32.8 ± 7.4 to 16.9 ± 1.9 ng/ml and a 33% reduction of food efficiency. Control MSP showed no effects. Conclusion: Results demonstrate potential of distinct MSPs to improve metabolic risk factors. Further studies investigating mechanism of action and confirming human safety are needed.

Novel technique: direct access partial nephrectomy approach through a transperitoneal working space (Roskilde technique).

Objectives: To describe a direct access partial nephrectomy technique through a transperitoneal working space (Roskilde technique).Materials and methods: Prospective single-center descriptive study between April 2015 and January 2017. The surgical outcomes are evaluated according to the Trifecta criteria (negative margins, warm ischemia time < 20 min and a Clavien-Dindo complication score < 3).Surgical procedure: The same access to the transperitoneal cavity as in a Standard transperitoneal Partial Nephrectomy was used. A direct access was established by incision of the peritoneum directly onto the renal fascia. The renal vessels and tumor were identified and the tumor removed with standard technique. The perinephric fat and peritoneum were then closed with a running suture.Results: In total, 122 patients underwent the Roskilde technique. The mean age was 62.2 years, the median Padua score was 12 (IQR = 9-12) and the median tumor size was 32 mm (IQR = 12-90). The median operative time was 101 min (IQR = 90-125). The trifecta achievement criteria goal was achieved in 116/122 (95%), with a median warm ischemia time of 8 min (IQR = 0-12).Conclusions: The Roskilde technique is safe and feasible. It can be performed on complex renal masses, and it seems to result in short operative times and high Trifecta achievement.Trial registration: None.

Inhibition of merozoite invasion and transient de-sequestration by sevuparin in humans with Plasmodium falciparum malaria.

SEVERE MALARIA: Even with the best available treatment, the mortality from severe Plasmodium falciparum malaria remains high. Typical features at death are high parasite loads and obstructed micro- vasculature. Infected erythrocytes (IE) containing mature parasites bind to the host receptor heparan sulfate, which is also an important receptor for merozoite invasion. To block merozoite invasion has not previously been proposed as an adjunctive therapeutic approach but it may preclude the early expansion of an infection that else leads to exacerbated sequestration and death. SEVUPARIN IN PHASE I STUDY: The drug sevuparin was developed from heparin because heparan sulfate and heparin are nearly identical, so the rationale was that sevuparin would act as a decoy receptor during malaria infection. A phase I study was performed in healthy male volunteers and sevuparin was found safe and well tolerated. SEVUPARIN IN PHASE I/II CLINICAL STUDY: A phase I/II clinical study was performed in which sevuparin was administered via short intravenous infusions to malaria patients with uncomplicated malaria who were also receiving atovaquone/proguanil treatment. This was a Phase I/II, randomized, open label, active control, parallel assignment study. Sevuparin was safe and well tolerated in the malaria patients. The mean relative numbers of ring-stage IEs decreased after a single sevuparin infusion and mature parasite IEs appeared transiently in the circulation. The effects observed on numbers of merozoites and throphozoites in the circulation, were detected already one hour after the first sevuparin injection. Here we report the development of a candidate drug named sevuparin that both blocks merozoite invasion and transiently de-sequesters IE in humans with P. falciparum malaria. TRIAL REGISTRATION: ClinicalTrials.gov NCT01442168.

Sevuparin binds to multiple adhesive ligands and reduces sickle red blood cell-induced vaso-occlusion.

Sevuparin is a novel drug candidate in phase II development as a treatment for vaso-occlusive crises (VOC) in patients with sickle cell disease (SCD). As a heparin-derived polysaccharide, sevuparin has been designed to retain anti-adhesive properties, while the antithrombin-binding domains have been eliminated, substantially diminishing its anticoagulant activity. Here, we demonstrate that sevuparin inhibits the adhesion of human sickle red blood cells (SS-RBCs) to stimulated cultured endothelial cells in vitro. Importantly, sevuparin prevents vaso-occlusion and normalizes blood flow in an in vivo mouse model of SCD vaso-occlusion. Analyses by surface plasmon resonance (SPR) and fluorescence correlation spectroscopy (FCS) demonstrate that sevuparin binds to P- and L-selectins, thrombospondin, fibronectin and von Willebrand factor, all of which are thought to contribute to vaso-occlusion in SCD. Despite low anticoagulation activity, sevuparin has anti-adhesive efficacy similar to the low molecular weight heparin tinzaparin both in vitro and in vivo. These results suggest that the anti-adhesive properties rather than the anticoagulant effects of heparinoids are critical for the treatment of vaso-occlusion in SCD. Therefore, sevuparin is now being evaluated in SCD patients hospitalized for treatment of VOC.

Classes and prediction of cell-penetrating peptides.

The classical view on how peptides enter cells has been changed due to the development in the research field of cell-penetrating peptides (CPPs). During the last 15 years, more than 100 peptide sequences have been published to enter cells and also to bring different biological cargoes with them. Here, we present an overview of CPPs, mainly trying to analyze their common properties yielding the prediction of their cell-penetrating properties. Furthermore, examples of recent research, ideas on classification and uptake mechanisms, as well as a summary of the therapeutic potential of CPPs are presented.

A unique cell division machinery in the Archaea.

In contrast to the cell division machineries of bacteria, euryarchaea, and eukaryotes, no division components have been identified in the second main archaeal phylum, Crenarchaeota. Here, we demonstrate that a three-gene operon, cdv, in the crenarchaeon Sulfolobus acidocaldarius, forms part of a unique cell division machinery. The operon is induced at the onset of genome segregation and division, and the Cdv proteins then polymerize between segregating nucleoids and persist throughout cell division, forming a successively smaller structure during constriction. The cdv operon is dramatically down-regulated after UV irradiation, indicating division inhibition in response to DNA damage, reminiscent of eukaryotic checkpoint systems. The cdv genes exhibit a complementary phylogenetic range relative to FtsZ-based archaeal division systems such that, in most archaeal lineages, either one or the other system is present. Two of the Cdv proteins, CdvB and CdvC, display homology to components of the eukaryotic ESCRT-III sorting complex involved in budding of luminal vesicles and HIV-1 virion release, suggesting mechanistic similarities and a common evolutionary origin.

Splice-switching efficiency and specificity for oligonucleotides with locked nucleic acid monomers.

The use of antisense oligonucleotides to modulate splicing patterns has gained increasing attention as a therapeutic platform and, hence, the mechanisms of splice-switching oligonucleotides are of interest. Cells expressing luciferase pre-mRNA interrupted by an aberrantly spliced beta-globin intron, HeLa pLuc705, were used to monitor the splice-switching activity of modified oligonucleotides by detection of the expression of functional luciferase. It was observed that phosphorothioate 2'-O-methyl RNA oligonucleotides containing locked nucleic acid monomers provide outstanding splice-switching activity. However, similar oligonucleotides with several mismatches do not impede splice-switching activity which indicates a risk for off-target effects. The splice-switching activity is abolished when mismatches are introduced at several positions with locked nucleic acid monomers suggesting that it is the locked nucleic acid monomers that give rise to low mismatch discrimination to target pre-mRNA. The results highlight the importance of rational sequence design to allow for high efficiency with simultaneous high mismatch discrimination for splice-switching oligonucleotides and suggest that splice-switching activity is tunable by utilizing locked nucleic acid monomers.

Protein delivery by the cell-penetrating peptide YTA2.

In most cases, the transport of cell-penetrating peptide (CPP) with a cargo molecule over the plasma membrane requires a cross-linking of the cargo molecule to the peptide. Lately, a method of cargo delivery, coincubation with CPP, has been applied. We have studied uptake and toxicity of the CPP, YTA2, in the Bowes human melanoma cell line and human MDA-MB-231 breast cancer cell line and compared the results with known cell-penetrating peptides. The results show that fluoresceinyl YTA2 is taken up by the Bowes cells with 3.23 nmol/mg protein and shows low membrane toxicity to the cells with an EC50 of 60 microM. Furthermore, we show that YTA2 is capable of delivering cargo proteins, such as beta-galactosidase and tetramethyl rhodamine iso-thiocyanate (TRITC) labeled streptavidin into cells by coincubation. The delivery of TRITC-labeled streptavidin was quantified to 42.4 pmol streptavidin/mg protein. The delivery of proteins into the cells by mere coincubation is an advantage, since the chemical coupling between the CPP and the cargo molecule, which adds time-consuming synthesis and purification steps, can be omitted. In addition, the flexibility in CPP cargo delivery is increased.