Shengxi Chen

Dengue viruses continue to pose a significant global public health challenge, especially in tropical and subtropical regions where access to centralized laboratory infrastructure is often limited. Prompt identification of dengue virus RNA during the early, acute phase of infection is essential for effective clinical management and timely outbreak response. However, widely used gold-standard techniques such as reverse transcription–polymerase chain reaction (RT-PCR) rely on enzymatic amplification, advanced instru-mentation, and skilled personnel, which restricts their use in point-of-care and re-source-constrained settings. In this work, an enzyme-free nucleic acid detection strategy based on semiconductor quantum dots (Qdots) is described for sensitive and specific dengue virus RNA detection at room temperature. The platform combines toe-hold-mediated strand displacement reactions (TMDRs) for precise sequence recognition with the strong fluorescence and signal amplification capabilities of Qdots. A highly con-served sequence at the 3′ end of the dengue genome was selected to enable detection across all four viral serotypes. Viral RNA is captured by surface-immobilized probes via TMDR, followed by binding Qdot-labeled detection probes and a Qdot-driven signal amplification step, all under isothermal conditions. The assay demonstrated femtomolar sensitivity us-ing synthetic RNA targets and maintained high performance in crude nucleic acid ex-tracts from contrived samples representing all dengue serotypes. Its modular, enzyme-free design offers a simple, rapid, and highly sensitive alternative to conventional amplifica-tion-based diagnostics, with strong potential for low-cost, portable applications in molec-ular diagnostics.

Protein phosphorylation is critical to selective gene expression; the proteins that regulate transcription are often phosphorylated at multiple sites. Serine and threonine phosphorylation in transcription factors such as NF‐ κ B has been studied, and specific serines are involved in transcriptional activation. Tyrosine phosphorylation of NF‐ κ B p50 subunit can also facilitate the NF‐ κ B‐mediated expression of CD40 protein. This study seeks to determine whether tyrosine phosphorylations at positions not normally phosphorylated in vivo could nonetheless affect protein expression mediated by NF‐ κ B. The alterations studied included p50 analogs having pTyr at positions 59 and 61, which do not contain Tyr naturally, and an analog containing a metabolically stable tyrosine methylene phosphonate at position 60. Additionally, to explore the structural basis for enhanced NF‐ κ B binding to CD40 promoter DNA by tyrosine phosphorylation, an analog of NF‐ κ B p50 containing pTyr at both positions 60 and 82 is prepared. The results reflected changes in the ability of the modified NF‐ κ Bs containing an altered p50 subunit to bind to CD40 promoter DNA in vitro, and to direct the synthesis of CD40 in cellulo.

Emerging and re-emerging pathogens continue to pose significant challenges to global health, because of the limits of current diagnostic, therapeutic, and preventive strategies

The discovery of EGFR mutations in 2004 and the subsequent development of small-molecule tyrosine kinase inhibitors (TKIs) marked a revolutionary step in lung cancer treatment (Lynch et al. 2004). Osimertinib, afatinib, gefitinib, erlotinib, and newer agents such as aumolertinib and furmonertinib have redefined the standard of care for patients with EGFR-mutant NSCLC (Fu et al. 2022). These agents selectively target oncogenic drivers, disrupting cancer cell proliferation while sparing healthy tissue, thus offering a more tailored and less toxic alternative to chemotherapy.Recent studies validate these advancements. For instance, a nationwide longitudinal study in Norway demonstrated a median overall survival (OS) of 23 months for EGFR+ patients diagnosed in recent years-a significant improvement compared to earlier cohorts (Nyen et al.). Meanwhile, aumolertinib, in addition to its efficacy, also showed remarkable improvements in patient-reported outcomes (PROs), indicating not just prolonged life, but improved day-to-day well-being (Li et al. https://doi.org/10.3389/fphar.2024.1444707).Despite early successes, resistance to EGFR-TKIs remains almost inevitable. Tumor heterogeneity and adaptive signaling mechanisms, including secondary EGFR mutations (e.g., T790M), MET amplification, and transformation into other histologies like small cell lung cancer (SCLC), complicate the therapeutic landscape (Dong et al. 2021;Jing et al. 2019).Recent case reports underscore these transformations. One patient with an EGFR exon 19 deletion developed SCLC following osimertinib therapy and required a shift to etoposide and cisplatin combined with immunotherapy for disease control (Li et al. https://doi.org/10.3389/fimmu.2024.1439033). Another case documented transformation to large cell neuroendocrine cancer (LCNEC) after almonertinib failure, emphasizing the importance of repeat biopsies to adapt treatment strategies(Cheng et al).Moreover, furmonertinib has shown promise in overcoming complex resistance. A single reported case yielded a progression-free survival (PFS) of 27 months in a heavily pre-treated patient with EGFR exon 20 insertion and PIK3CA mutations, supporting its potential in refractory settings (Sun & Wang).While EGFR-TKIs are generally well tolerated compared to traditional chemotherapy, accumulating data reveal a non-trivial burden of adverse events (AEs), some of which can be severe or even fatal. Osimertinib, for instance, though highly effective, has been associated with increased cardiotoxicity-including heart failure, arrhythmias, and hypertension (Wang et al. https://doi.org/10.3389/fonc.2024.1426796). A recent observational study found a 21.6% incidence of cardiotoxicity among osimertinib-treated patients, with smoking history, hyperlipidemia, and concurrent chemo/radiotherapy identified as significant risk factors (Wang et al. https://doi.org/10.3389/fonc.2024.1431023).Network meta-analyses and pharmacovigilance reports from the FDA Adverse Event Reporting System (FAERS) further highlight drug-specific AE profiles. Afatinib and osimertinib have higher toxicity rankings, while icotinib and erlotinib are comparatively safer in terms of overall AE incidence (Shi et al).Perhaps most concerning are the rare but serious complications. One patient developed interstitial lung disease from almonertinib (Yang et al.), and another developed type 1 diabetes following anlotinib treatment (Chen et al.), illustrating the importance of close monitoring and personalized risk-benefit assessment.As resistance mechanisms continue to emerge, innovative therapeutic strategies must be developed in parallel. Whole exome sequencing (WES) has enabled the identification of rare and resistant EGFR mutations-such as G724E and K745L-that compromise drug efficacy (Nagarajan and Guda). Virtual screening against these mutations has yielded promising lead compounds, reigniting hopes for overcoming resistance at a molecular level.Combination therapies are also gaining traction. Immune checkpoint inhibitors (ICIs), though traditionally less effective in EGFR-mutated NSCLC, have shown potential when combined with antiangiogenic agents and chemotherapy (Zhu et al.). A network meta-analysis suggests that this triplet regimen may offer the best survival outcomes, albeit with increased toxicity.Co-targeting other HER receptors alongside EGFR represents a promising therapeutic avenue. Recently, a HER3-targeted antibody-drug conjugate, patritumab deruxtecan, received approval for the treatment of HER1-mutant non-small cell lung cancer (NSCLC) (Cai et al, 2022 and2023) Moreover, targeting co-alterations such as HER2 overexpression with agents like disitamab vedotin (RC48) offers another frontier (Lan et al.). In a remarkable case, a patient with EGFR and HER2 coalterations maintained stable disease through eight lines of therapy, culminating in disease control with RC48 and local interventions.The current studies reaffirm the transformative power of EGFR-TKIs in lung cancer treatment. However, it also reveals a landscape fraught with complexity. Resistance is complex and often unpredictable, while adverse effects can be severe and require proactive management (Tan et al.).Future strategies should emphasize a comprehensive approach that includes personalized treatment planning through genomic profiling and assessment of comorbidities and adverse event risks to tailor both initial and follow-up therapies. Rigorous surveillance and early detection protocols should be implemented to monitor cardiotoxicity, interstitial lung disease, and metabolic disturbances. Mechanism-driven drug development is essential, focusing on next-generation TKIs that effectively target rare mutations while offering improved safety. Additionally, exploring innovative combination regimens that integrate TKIs with immune checkpoint inhibitors and antiangiogenic agents may help delay or overcome resistance. Finally, patient-centered care should...

ConspectusProteins and peptides occur ubiquitously in organisms and play key functional roles, as structural elements and catalysts. Their major natural source is ribosomal synthesis, which produces polypeptides from 20 amino acid building blocks. Peptides containing noncanonical amino acids have long been prepared by chemical synthesis, which has provided a wealth of physiologically active compounds. Comparatively, preparing modified proteins has been more challenging. Site-directed mutagenesis provided an important advance but was initially limited to canonical amino acids. New techniques for tRNA activation with noncanonical amino acids subsequently increased the scope of site-directed mutagenesis.Our report in 2012 demonstrated that modification of bacterial ribosomes at key positions enabled the selection of ribosomes capable of introducing β-amino acids into proteins in vitro. The generality of the selection procedure was tested further. Ribosomes capable of incorporating dipeptides, conformationally constrained dipeptides, dipeptidometics with embedded fluorophores, contiguous nucleobase amino acids, and phosphorylated amino acids were successfully identified.In this Account, we focus on the application of the new technology to dramatically alter protein structure in ways that enable new strategies for understanding and altering protein function. To illustrate the robustness of the technology we have provided examples studied in vitro and in cellulo. The first category involves the introduction of nucleobase amino acids into proteins in support of specific interactions with RNA and DNA. The energetic differences between potential protein-nucleic acid complexes formed from two binding partners are often quite small. It seems logical to think that selective binding can be achieved by using a nucleobase moiety in each of the binding partners by utilizing known interactions between nucleic acid bases (located in the protein and nucleic acid) to achieve energetically favorable interactions. We do so both in vitro and in cellulo. A second focus has involved the design of small fluorescent probes not much larger than amino acids that are genetically encodable and which can be incorporated during protein biosynthesis, serving as detectable probes of protein trafficking and interaction with other macromolecules. We provide an in vitro example of strongly fluorescent tryptophan analogues positioned at single sites within dihydrofolate reductase, permitting selective communication with a FRET acceptor at a known position, even in the presence of several tryptophans. An oxazole amino acid, weakly fluorescent in aqueous solution, fluoresced more strongly following incorporation into MreB, a scaffold protein produced in cellulo. Finally, we describe the introduction of a single phosphorylated tyrosine into the p50 subunit of NF-κB. When present at either of two key positions, the resulting NF-κB significantly enhanced binding in vitro to the promoter DNA as well as subsequent mRNA transcription of its client protein CD40 in cellulo. In a separate expression in activated Jurkat cells, an increased production of CD40 protein was observed.

Research has demonstrated a close correlation between human microbiota and overall health, highlighting their intimate connection. Exposure to environmental factors, such as chemical contaminants and biological agents, has the potential to alter the composition and function of microbiota, thereby influencing health outcomes. Meanwhile, microbiota may contribute to host protection by degrading, or rendering harmless, exposures. Environmental exposures demonstrate significant diversity and dynamism; however, conventional methods for exposure–microbiota research, such as animal and epidemiological studies, are often both time-consuming and costly. Additionally, they may raise ethical concerns. This review aimed to examine the existing understanding of employing in vitro models to investigate the interactions between environmental exposures and human microbiota, particularly those located outside the large intestine. A comprehensive search was conducted across the Web of Science, PubMed, and Scopus databases, employing a range of keywords related to microbiota, exposures, and in vitro models. A total of 58 studies fulfilled the search criteria, revealing instances of microbial modulation of exposures and vice versa. It was observed that, although considerable research has been conducted on these interactions in vitro, there remains a pressing need for enhanced model designs and application contexts.

Research has demonstrated a close correlation between human microbiota and overall health, highlighting their intimate connection. Exposure to environmental factors, such as chemical contaminants and biological agents, has the potential to alter the composition and function of microbiota, thereby influencing health outcomes. Meanwhile, microbiota may contribute to host protection by degrading or rendering harmless exposures. Environmental exposures demonstrate significant diversity and dynamism; however, conventional methods for exposure-microbiota research, such as animal and epidemiological studies, are often both time-consuming and costly. Additionally, they may raise ethical concerns. In this review, we rigorously examine the existing understanding of employing in vitro models, a cost-effective, swift, and dependable approach, to investigate the interactions between environmental exposures and human microbiota. We summarize the advantages of applying in vitro models to study the interactions, identify knowledge gaps in this field, and propose promising directions for future research.