Prodrug-conjugated tumor-seeking commensals for targeted cancer therapy.

Prodrugs have been explored as an alternative to conventional chemotherapy; however, their target specificity remains limited. The tumor microenvironment harbors a range of microorganisms that potentially serve as tumor-targeting vectors for delivering prodrugs. In this study, we harness bacteria-cancer interactions native to the tumor microbiome to achieve high target specificity for prodrug delivery. We identify an oral commensal strain of Lactobacillus plantarum with an intrinsic cancer-binding mechanism and engineer the strain to enable the surface loading of anticancer prodrugs, with nasopharyngeal carcinoma (NPC) as a model cancer. The engineered commensals show specific binding to NPC via OppA-mediated recognition of surface heparan sulfate, and the loaded prodrugs are activated by tumor-associated biosignals to release SN-38, a chemotherapy compound, near NPC. In vitro experiments demonstrate that the prodrug-loaded microbes significantly increase the potency of SN-38 against NPC cell lines, up to 10-fold. In a mouse xenograft model, intravenous injection of the engineered L. plantarum leads to bacterial colonization in NPC tumors and a 67% inhibition in tumor growth, enhancing the efficacy of SN-38 by 54%.

Immunotherapy-Induced Overlap Syndrome: Myositis, Myasthenia Gravis, and Myocarditis-A Case Series.

Immune checkpoint inhibitors (ICI) are monoclonal antibodies that target immune checkpoint inhibitory receptors. They have revolutionised cancer treatment but can be associated with a wide range of adverse side effects. Rarely, they can be associated with the triad of myositis, myasthenia gravis, and myocarditis or overlap syndrome. Prompt recognition and early intervention are needed to treat these potentially life-threatening conditions. We report a case series of patients with ICI-related overlap syndrome, including the first with avelumab, and discuss the current management guidelines.

FELICX: A robust nucleic acid detection method using flap endonuclease and CRISPR-Cas12.

Nucleic acid detection is crucial for monitoring diseases for which rapid, sensitive, and easy-to-deploy diagnostic tools are needed. CRISPR-based technologies can potentially fulfill this need for nucleic acid detection. However, their widespread use has been restricted by the requirement of a protospacer adjacent motif in the target and extensive guide RNA optimization. In this study, we developed FELICX, a technique that can overcome these limitations and provide a useful alternative to existing technologies. FELICX comprises flap endonuclease, Taq ligase and CRISPR-Cas for diagnostics (X) and can be used for detecting nucleic acids and single-nucleotide polymorphisms. This method can be deployed as a point-of-care test, as only two temperatures are needed without thermocycling for its functionality, with the result generated on lateral flow strips. As a proof-of-concept, we showed that up to 0.6 copies/µL of DNA and RNA could be detected by FELICX in 60 min and 90 min, respectively, using simulated samples. Additionally, FELICX could be used to probe any base pair, unlike other CRISPR-based technologies. Finally, we demonstrated the versatility of FELICX by employing it for virus detection in infected human cells, the identification of antibiotic-resistant bacteria, and cancer diagnostics using simulated samples. Based on its unique advantages, we envision the use of FELICX as a next-generation CRISPR-based technology in nucleic acid diagnostics.

Engineered microbial systems for advanced drug delivery.

The human body is a natural habitat for a multitude of microorganisms, with bacteria being the major constituent of the microbiota. These bacteria colonize discrete anatomical locations that provide suitable conditions for their survival. Many bacterial species, both symbiotic and pathogenic, interact with the host via biochemical signaling. Based on these attributes, commensal and attenuated pathogenic bacteria have been engineered to deliver therapeutic molecules to target specific diseases. Recent advances in synthetic biology have enabled us to perform complex genetic modifications in live bacteria and bacteria-derived particles, which simulate micron or submicron lipid-based vectors, for the targeted delivery of therapeutic agents. In this review, we highlight various examples of engineered bacteria or bacteria-derived particles that encapsulate, secrete, or surface-display therapeutic molecules for the treatment or prevention of various diseases. The review highlights recent studies on (i) the production of therapeutics by microbial cell factories, (ii) disease-triggered release of therapeutics by sense and respond systems, (iii) bacteria targeting tumor hypoxia, and (iv) bacteria-derived particles as chassis for drug delivery. In addition, we discuss the potential of such drug delivery systems to be translated into clinical therapies.

Systematic review and meta-analysis of tumour microsatellite-instability status as a predictor of response to fluorouracil-based adjuvant chemotherapy in colorectal cancer.

PURPOSE: Colorectal cancer (CRC) can be classified according to the chromosomal-instability pathway (a microsatellite-stable (MSS) pathway) and the microsatellite-instability (MSI) pathway. Adjuvant therapy after surgery in advanced CRC is usually based on fluoropyrimidine 5-fluorouracil (5-FU) alone or combined with other agents. Controversy however remains on the use of 5-FU-based regimens in treating MSI-related tumours. AIMS: To systematically investigate the relationship between tumour microsatellite profile and 5-year overall survival in patients with CRC treated with 5-FU. METHODS: A systematic literature review of PubMed and Embase databases was conducted. Pre-specified criteria determined study inclusion/exclusion. The PRISMA and QUADAS-2 criteria were used to assess study suitability and quality respectively. Patients were categorised as having either MSI or MSS CRC. Overall 5-year survival was estimated from Kaplan-Meier curves. Publication bias was assessed using funnel-plots and Egger's test. RESULTS: 1807 studies were identified, with meta-analysis performed using nine studies. 5-FU treated individuals with CRC who died at 5 years were found to be 0.31 times less likely to have MSI than those who were alive, although this was not statistically significant. There was an insufficient number of studies to enable subgroup analysis by stage. CONCLUSIONS: In this meta-analysis, MSI status does not alter 5-year survival of patients with CRC patients treated with adjuvant 5-FU, however there is significant heterogeneity in the design of individual studies in the data synthesis. More studies are necessary to clarify whether CRC patients with MSI CRC, in particular early stage, should be offered 5-FU based adjuvant chemotherapy.

Engineering probiotics for therapeutic applications: recent examples and translational outlook.

Engineered probiotics are the next generation of live biotherapeutics that have been genetically modified to target specific diseases. With the advancements in synthetic biology, the engineering of probiotics has become increasingly sophisticated which has led to the development of therapies for treating cancer, infection, metabolic disorders and inflammation, as well as for diagnosing and preventing them. Herein, we review some of the recent examples of probiotics which have been engineered to target such diseases. Although there are numerous examples of engineered probiotics showing efficacy in animal models, there are no approved products on the market with very few in clinical trials. Therefore, we also discuss a set of features that may be incorporated into engineered probiotics to aid in clinical translation and ultimately, realizing the potential of these biotherapeutics.

Appendiceal mucocele secondary to torsion in an asymptomatic patient.

Torsion of the appendix associated with an appendiceal mucocele is extremely rare with just a few published cases. To our knowledge, we report the first case of appendiceal mucocele secondary to torsion in an asymptomatic patient. In this case, numerous adhesions were found attaching the tip of the appendix mucocele to the peritoneum contributing to torsion as well as a lack of evidence for appendiceal neoplasm. Complications of appendiceal mucocele include obstruction, intussusception and pseudomyxoma peritonei, which has a particularly poor prognosis. Clinicians should, therefore, consider prompt surgical resection for definitive histopathological diagnosis and management.

Osteoprotegerin and Myocardial Fibrosis in Patients with Aortic Stenosis.

Left ventricular myocardial fibrosis in patients with aortic stenosis (AS) confers worse prognosis. Plasma osteoprotegerin (OPG), a cytokine from the TNF receptor family, correlates with the degree of valve calcification in AS, reflecting the activity of the tissue RANKL/RANK/OPG (receptor activator of nuclear factor κΒ ligand/RANK/osteoprotegerin) axis, and is associated with poorer outcomes in AS. Its association with myocardial fibrosis is unknown. We hypothesised that OPG levels would reflect the extent of myocardial fibrosis in AS. We included 110 consecutive patients with AS who had undergone late-gadolinium contrast enhanced cardiovascular magnetic resonance (LGE-CMR). Patients were characterised according to pattern of fibrosis (no fibrosis, midwall fibrosis, or chronic myocardial infarction fibrosis). Serum OPG was measured with ELISA and compared between groups defined by valve stenosis severity. Some 36 patients had no fibrosis, 38 had midwall fibrosis, and 36 had chronic infarction. Patients with midwall fibrosis did not have higher levels of OPG compared to those without fibrosis (6.78 vs. 5.25 pmol/L, p = 0.12). There was no difference between those with midwall or chronic myocardial infarction fibrosis (6.78 vs. 6.97 pmol/L, p = 0.27). However, OPG levels in patients with chronic myocardial infarction fibrosis were significantly higher than those without fibrosis (p = 0.005).

Correction to: Treatment of Obesity in Young People-a Systematic Review and Meta-analysis.

In the original article, due to a production error, the text for the "Principle Findings" section was omitted as was the heading for the "Strengths and Limitations" section. The original article has been updated to correct these errors.

Treatment of Obesity in Young People-a Systematic Review and Meta-analysis.

Obesity in the young is increasingly prevalent. Early, effective intervention is paramount. Treatment options are lifestyle modifications, pharmacological therapies, endoscopic treatments and bariatric surgery. However, the relative effectiveness of these treatments in young patients remains unclear. We systematically identify and meta-analyse studies evaluating weight loss treatments in young people (< 21 years) with obesity. From 16,372 identified studies, 83 were eligible for meta-analysis. Bariatric surgery resulted in high short/medium-term weight loss (pooled estimate 14.04 kg/m2). Lifestyle and pharmacological therapies impacted weight more moderately (pooled estimate 0.99 and 0.94 kg/m2 respectively). Due to its high efficacy, bariatric surgery should be considered earlier when treating obesity in young people. However, due to the invasiveness and inherent risks of bariatric surgery, all other weight loss routes should be exhausted first.

The Association of Low-Penetrance Variants in DNA Repair Genes with Colorectal Cancer: A Systematic Review and Meta-Analysis.

OBJECTIVES: Approximately 35% of colorectal cancer (CRC) risk is attributable to heritable factors known hereditary syndromes, accounting for 6%. The remainder may be due to lower penetrance polymorphisms particularly of DNA repair genes. DNA repair pathways, including base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), direct reversal repair (DRR), and double-strand break repair are complex, evolutionarily conserved, and critical in carcinogenesis. Germline mutations in these genes are associated with high-penetrance CRC syndromes such as Lynch syndrome. However, the association of low-penetrance polymorphisms of DNA repair genes with CRC risk remains unclear. METHODS: A systematic literature review of PubMed, Embase, and HuGENet databases was conducted. Pre-specified criteria determined study inclusion/exclusion. Per-allele, pooled odds ratios disclosed the risk attributed to each variant. Heterogeneity was investigated by subgroup analyses for ethnicity and tumor location; funnel plots and Egger's test assessed publication bias. RESULTS: Sixty-one polymorphisms in 26 different DNA repair genes were identified. Meta-analyses for 22 polymorphisms in 17 genes revealed that six polymorphisms were significantly associated with CRC risk within BER (APE1, PARP1), NER (ERCC5, XPC), double-strand break (RAD18), and DRR (MGMT), but none within MMR. Subgroup analyses revealed significant association of OGG1 rs1052133 with rectal cancer risk. Egger's test revealed no publication bias. CONCLUSIONS: Low-penetrance polymorphisms in DNA repair genes alter susceptibility to CRC. Future studies should therefore analyze whole-genome polymorphisms and any synergistic effects on CRC risk.Translational impact:This knowledge may enhance CRC risk assessment and facilitate a more personalized approach to cancer prevention.

Designer probiotics for the prevention and treatment of human diseases.

Various studies have shown the beneficial effects of probiotics in humans. The use of synthetic biology to engineer programmable probiotics that specifically targets cancer, infectious agents, or other metabolic diseases has gained much interest since the last decade. Developments made in synthetic probiotics as therapeutics within the last three years will be discussed in this review.

Delayed thrombin-induced platelet-fibrin clot generation by clopidogrel: a new dose-related effect demonstrated by thrombelastography in patients undergoing coronary artery stenting.

BACKGROUND: We have previously demonstrated that clopidogrel reduces platelet activation and aggregation in patients undergoing stenting. However, the effect of the clopidogrel loading dose on the rate of thrombin-induced platelet-fibrin clot formation is unknown in this patient population. METHODS AND RESULTS: Using thrombelastography (TEG) we measured the time to platelet-fibrin clot formation (R), a marker of the speed of thrombin generation, in 120 patients undergoing elective coronary artery stenting treated with standard and high loading doses of clopidogrel. Platelet reactivity to adenosine diphosphate (ADP) by light transmittance aggregometry (LTA) was determined simultaneously. Measurements were made immediately before and at 24 h after clopidogrel treatment. Clopidogrel produced a prolongation in R (4.4+/-1.4 min pre vs. 5.4+/-1.7 min post, p<0.001) that directly correlated with the change in platelet aggregation (r=0.65, p<0.0001). Prolongation in R was greatest in patients treated with a high loading dose (p=0.004). CONCLUSIONS: Delayed thrombin-induced platelet-fibrin clot formation as measured by TEG is a newly reported dose-related effect of clopidogrel that may contribute to the overall antithrombotic properties of the drug in patients undergoing stenting. This effect was more marked in patients loaded with 600 mg, lending further mechanistic support for this dose of clopidogrel as a more effective antithrombotic regimen than the standard 300 mg dose. Measurement of R may serve as a new indicator of clopidogrel responsiveness.