Bifunctional HDAC and DNMT inhibitor induces viral mimicry activates the innate immune response in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a unique breast cancer subtype characterized by a lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression. Since TNBC lacks ER, PR, and HER2, there are currently no drugs that specifically target TNBC. Therefore, the development of new drugs or effective treatment strategies to target TNBC has become an urgent clinical need. Research has shown that the application of histone deacetylase (HDAC) inhibitors and DNA methyltransferase (DNMT) inhibitors leads to genomic and epigenomic instability. This, in turn, triggers the activation of pattern recognition receptors (PRRs) and subsequently activates downstream interferon (IFN) signalling pathways. In this study, the bifunctional HDAC and DNMT inhibitor J208 exhibited antitumour activity in TNBC cell lines. J208 effectively induced apoptosis and cell cycle arrest at the G0/G1 phase, inhibiting cell migration and invasion in TNBC. Moreover, this bifunctional inhibitor induced the expression of endogenous retroviruses (ERVs) and elicited a viral mimicry response, which increased the intracellular levels of double-stranded RNA (dsRNA) to activate the innate immune signalling pathway in TNBC. In summary, we demonstrated that the bifunctional inhibitor J208, which is designed to inhibit HDAC and DNMT, has potent anticancer effects, providing a new research basis for reactivating antitumour immunity by triggering innate immune signalling and offering a promising strategy for TNBC treatment.

Discovery of novel nucleoside derivatives as selective lysine acetyltransferase p300 inhibitors for cancer therapy.

P300 and CBP are two closely related histone acetyltransferases that are important transcriptional coactivators of many cellular processes. Inhibition of the transcriptional regulator p300/CBP is a promising therapeutic approach in oncology. However, there are no reported single selective p300 or CBP inhibitors to date. In this study, we designed and optimized a series of lysine acetyltransferase p300 selective inhibitors bearing a nucleoside scaffold. Most compounds showed excellent inhibitory activity against p300 with IC50 ranging from 0.18 to 9.90 µM, except for J16, J29, J40, and J48. None of the compounds showed inhibitory activity against CBP (inhibition rate < 50 % at 10 µM). Then the cytotoxicity of the compounds against a series of cancer cells were evaluated. Compounds J31 and J32 showed excellent proliferation inhibitory activity on cancer cells T47D and H520 with desirable selectivity profile of p300 over CBP. These compounds could be promising lead compounds for the development of novel epigenetic inhibitors as antitumor agents.

Dual inhibitors of DNMT and HDAC induce viral mimicry to induce antitumour immunity in breast cancer.

The existing conventional treatments for breast cancer, including immune checkpoint blockade, exhibit limited effects in some cancers, particularly triple-negative breast cancer. Epigenetic alterations, specifically DNMT and HDAC alterations, are implicated in breast cancer pathogenesis. We demonstrated that DNMTs and HDACs are overexpressed and positively correlated in breast cancer. The combination of DNMT and HDAC inhibitors has shown synergistic antitumour effects, and our previously designed dual DNMT and HDAC inhibitor (termed DNMT/HDACi) 15a potently inhibits breast cancer cell proliferation, migration, and invasion and induces apoptosis in vitro and in vivo. Mechanistically, 15a induces a viral mimicry response by promoting the expression of endogenous retroviral elements in breast cancer cells, thus increasing the intracellular level of double-stranded RNA to activate the RIG-I-MAVS pathway. This in turn promotes the production of interferons and chemokines and augments the expression of interferon-stimulated genes and PD-L1. The combination of 15a and an anti-PD-L1 antibody had an additive effect in vivo. These findings indicate that this DNMT/HDACi has immunomodulatory functions and enhances the effectiveness of immune checkpoint blockade therapy. A novel dual DNMT and HDAC inhibitor induces viral mimicry, which induces the accumulation of dsRNA to activate tumoral IFN signalling and cytokine production to enhance the immune response in breast cancer.

mRNA PROTACs: engineering PROTACs for high-efficiency targeted protein degradation.

Proteolysis-targeting chimeras (PROTACs) are essential bifunctional molecules that target proteins of interest (POIs) for degradation by cellular ubiquitination machinery. Despite significant progress made in understanding PROTACs' functions, their therapeutic potential remains largely untapped. As a result of the success of highly flexible, scalable, and low-cost mRNA therapies, as well as the advantages of the first generation of peptide PROTACs (p-PROTACs), we present for the first time an engineering mRNA PROTACs (m-PROTACs) strategy. This design combines von Hippel-Lindau (VHL) recruiting peptide encoding mRNA and POI-binding peptide encoding mRNA to form m-PROTAC and promote cellular POI degradation. We then performed proof-of-concept experiments using two m-PROTACs targeting two cancer-related proteins, estrogen receptor alpha and B-cell lymphoma-extra large protein. Our results demonstrated that m-PROTACs could successfully degrade the POIs in different cell lines and more effectively inhibit cell proliferation than the traditional p-PROTACs. Moreover, the in vivo experiment demonstrated that m-PROTAC led to significant tumor regression in the 4T1 mouse xenograft model. This finding highlights the enormous potential of m-PROTAC as a promising approach for targeted protein degradation therapy.

Design, synthesis, and evaluation of VHL-based EZH2 degraders for breast cancer.

EZH2 (enhancer of zeste homolog 2) is one of the most important histone methyltransferases (HMTs), and overexpression of EZH2 can lead to proliferation, migration and angiogenesis of tumor cells. But most of EZH2 inhibitors are only effective against some hematologic malignancies and have poor efficacy against solid tumors. Here, we report the design, synthesis, and evaluation of highly potent proteolysis targeting chimeric (PROTACs) small molecules targeting EZH2. We developed a potent and effective EZH2 degrader P4, which effectively induced EZH2 protein degradation and inhibited breast cancer cell growth. Further studies showed that P4 can significantly decrease the degree of H3K27me3 in MDA-MB-231 cell line, induce apoptosis and G0/G1 phase arrest in Pfeiffer and MDA-MB-231 cell lines. Therefore, P4 is a potential anticancer molecule for breast cancer treatment.

Novel dual inhibitors of PARP and HDAC induce intratumoral STING-mediated antitumor immunity in triple-negative breast cancer.

PARP inhibitors and HDAC inhibitors have been approved for the clinical treatment of malignancies, but acquired resistance of or limited effects on solid tumors with a single agent remain as challenges. Bioinformatics analyses and a combination of experiments had demonstrated the synergistic effects of PARP and HDAC inhibitors in triple-negative breast cancer. A series of novel dual PARP and HDAC inhibitors were rationally designed and synthesized, and these molecules exhibited high enzyme inhibition activity with excellent antitumor effects in vitro and in vivo. Mechanistically, dual PARP and HDAC inhibitors induced BRCAness to restore synthetic lethality and promoted cytosolic DNA accumulation, which further activates the cGAS-STING pathway and produces proinflammatory chemokines through type I IFN-mediated JAK-STAT pathway. Moreover, these inhibitors promoted neoantigen generation, upregulated antigen presentation genes and PD-L1, and enhanced antitumor immunity when combined with immune checkpoint blockade therapy. These results indicated that novel dual PARP and HDAC inhibitors have antitumor immunomodulatory functions in triple-negative breast cancer. Novel dual PARP and HDAC inhibitors induce BRCAness to restore synthetic lethality, activating tumoral IFN signaling via the cGAS-STING pathway and inducing cytokine production, promoting neoantigen generation and presentation to enhance the immune response.

Global and local functions of the Fused kinase ortholog CdaH in intracellular patterning in Tetrahymena.

Ciliates assemble numerous microtubular structures into complex cortical patterns. During ciliate division, the pattern is duplicated by intracellular segmentation that produces a tandem of daughter cells. In Tetrahymena thermophila, the induction and positioning of the division boundary involves two mutually antagonistic factors: posterior CdaA (cyclin E) and anterior CdaI (Hippo kinase). Here, we characterized the related cdaH-1 allele, which confers a pleiotropic patterning phenotype including an absence of the division boundary and an anterior-posterior mispositioning of the new oral apparatus. CdaH is a Fused or Stk36 kinase ortholog that localizes to multiple sites that correlate with the effects of its loss, including the division boundary and the new oral apparatus. CdaH acts downstream of CdaA to induce the division boundary and drives asymmetric cytokinesis at the tip of the posterior daughter. CdaH both maintains the anterior-posterior position of the new oral apparatus and interacts with CdaI to pattern ciliary rows within the oral apparatus. Thus, CdaH acts at multiple scales, from induction and positioning of structures on the cell-wide polarity axis to local organelle-level patterning.

Universal smartphone-assisted label-free CRISPR/Cas12a-DNAzyme chemiluminescence biosensing platform for on-site detection of nucleic acid and non-nucleic acid targets.

The clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein (Cas) (CRISPR/Cas) system enables sensitive and specific detection of biomolecules, thanks to its programmability, high fidelity, and powerful signal amplification capabilities. Herein, a universal smartphone-assisted label-free G-quadruplex (G4) DNAzyme-based chemiluminescence CRISPR/Cas12a biosensing platform (G4CLCas) is firstly described that achieves on-site, ultrasensitive visual detection of nucleic acid and non-nucleic acid targets. The G4CLCas-based sensing platform relies on Cas12a trans-cleavage activation that triggers the cleavage of the G4 DNAzyme, resulting in chemiluminescence signals off/on compared to that of the control. Chemiluminescence signals are captured as images that are quantitatively analyzed and visualized using a smartphone-assisted imaging cartridge. Under optimal conditions, G4CLCas achieves a low limit of detection (LOD) of 8.6 aM (∼5.2 copies/µL) for monkeypox virus (MPXV) DNA within the linear concentration range of 10-300 aM and can accurately quantify viral DNA in spiked samples. G4CLCas can also detect non-nucleic acid targets, whereby it achieves a low LOD value of 84.3 nM for adenosine triphosphate (ATP) within the linear concentration range of 2-2000 µM. Here, a label-free, portable, on-site CRISPR/Cas12a chemiluminescence biosensing platform based on the G4 DNAzyme substrates is proposed with potential applications in clinical detection and bioanalytical chemistry research.

An interpretable artificial intelligence framework for designing synthetic lethality-based anti-cancer combination therapies.

INTRODUCTION: Synthetic lethality (SL) provides an opportunity to leverage different genetic interactions when designing synergistic combination therapies. To further explore SL-based combination therapies for cancer treatment, it is important to identify and mechanistically characterize more SL interactions. Artificial intelligence (AI) methods have recently been proposed for SL prediction, but the results of these models are often not interpretable such that deriving the underlying mechanism can be challenging. OBJECTIVES: This study aims to develop an interpretable AI framework for SL prediction and subsequently utilize it to design SL-based synergistic combination therapies. METHODS: We propose a knowledge and data dual-driven AI framework for SL prediction (KDDSL). Specifically, we use gene knowledge related to the SL mechanism to guide the construction of the model and develop a method to identify the most relevant gene knowledge for the predicted results. RESULTS: Experimental and literature-based validation confirmed a good balance between predictive and interpretable ability when using KDDSL. Moreover, we demonstrated that KDDSL could help to discover promising drug combinations and clarify associated biological processes, such as the combination of MDM2 and CDK9 inhibitors, which exhibited significant anti-cancer effects in vitro and in vivo. CONCLUSION: These data underscore the potential of KDDSL to guide SL-based combination therapy design. There is a need for biomedicine-focused AI strategies to combine rational biological knowledge with developed models.

Conjugated Polyelectrolyte/Single Strand DNA Hybrid Polyplexes for Efficient Nucleic Acid Delivery and Targeted Protein Degradation.

Nucleic acid-based therapeutics have gained increasing attention due to their ability to regulate various genetic disorders. However, the safe and effective delivery of nucleic acids to their intended cellular sites remains a challenge, primarily due to poor cell membrane permeation and low in vivo stability. Limitations associated with the commonly used nucleic acid delivering agent viral vectors such as carcinogenesis and immunogenicity have driven scientists to develop various nonviral vectors. In this study, we present a highly efficient nucleic acid delivery system based on cationic conjugated polyelectrolytes and single-strand DNA polyplexes with further application in efficient ubiquitin-regulated targeting protein degradation. These polyplexes, formed by 9TC, an aptamer sequence for estrogen receptor (ERα), and cationic PPET3N2 through electrostatic and hydrophobic interactions, demonstrate improved cellular uptake efficiency as well as enhanced stability against nuclease degradation. Furthermore, by incorporation of 9TC into a proteolysis targeting chimera (PROTAC) molecule (P9TC), PPET3N2/P9TC polyplexes significantly enhance the target protein ERα degradation efficiency. Collectively, our findings suggest that PPET3N2 provides a versatile, low cytotoxicity platform for safe, efficient, and simplified delivery of nucleic acids.

Design, synthesis and biological evaluation of pyrimidine base hydroxamic acid derivatives as dual JMJD3 and HDAC inhibitors.

The Jumonji domain-containing protein demethylase 3 (JMJD3) and histone deacetylase (HADC) are related to various cancers and regard as antitumor targets for drug discovery. In this study, based on rational drug design strategy, we designed and synthesized a series of pyrimidine derivatives with hydroxamic acid as novel dual JMJD3 and HDAC inhibitors for synergistic cancer treatment. Compound A5b exhibited inhibitory potency against JMJD3 and HDAC1/6 simultaneously and favorable cytotoxicity against human cancer cells such as A549 and U937. Furthermore, mechanistic studies showed that A5b treatment in A549 cells increased the hypermethylation of histone H3K27 and hyperacetylation of H3K9, suppressed clonogenicity, migration and invasion of cancer cells. Besides, A5b induced apoptosis via the cleavage of caspase-7 and PARP, and G1 cell cycle arrest via upregulated p21 expression. All these results suggested that A5b was the first dual inhibitor against JMJD3 and HDAC and can be a potential compound for cancer therapy.

Whole-Bacterium SELEX Aptamer Selection of Fusobacterium nucleatum and Application to Colorectal Cancer Noninvasive Screening in Human Feces.

In terms of cancer diagnoses and cancer-related deaths worldwide, colorectal cancer (CRC) is now the third most common malignancy. The drawbacks of current screening methods are their exorbitant costs, difficult procedures, and lengthy implementation timelines. The benefits of fecal screening for CRC are ease of operation, noninvasiveness, cost-effectiveness, and superior sensitivity. As a result of its enrichment in the malignant tissues and feces of CRC patients, Fusobacterium nucleatum (F. nucleatum) has emerged as a crucial biomarker for the incipient detection, identification, and prognostic prediction of CRC. Here, for the first time, the whole-bacterium SELEX method was used to screen the highly specific and affinity aptamers against F. nucleatum by 13 cycles of selection. The Apt-S-5 linear correlation equation is y = 0.7363x2.8315 (R2 = 0.9864) with a limit of detection (LOD) of 851 CFU/mL. The results of the experiment using fecal samples revealed a substantial disparity between the microorganisms in the CRC patients' feces and those in the feces of healthy individuals and were consistent with those of qPCR. The aptamers may therefore offer a crucial approach to identifying F. nucleatum and hold tremendous promise for CRC diagnosis and prognostic prediction.

Antitumor Activity of s-Triazine Derivatives: A Systematic Review.

1,3,5-triazine derivatives, also called s-triazines, are a series of containing-nitrogen heterocyclic compounds that play an important role in anticancer drug design and development. To date, three s-triazine derivatives, including altretamine, gedatolisib, and enasidenib, have already been approved for refractory ovarian cancer, metastatic breast cancer, and leukemia therapy, respectively, demonstrating that the s-triazine core is a useful scaffold for the discovery of novel anticancer drugs. In this review, we mainly focus on s-triazines targeting topoisomerases, tyrosine kinases, phosphoinositide 3-kinases, NADP+-dependent isocitrate dehydrogenases, and cyclin-dependent kinases in diverse signaling pathways, which have been extensively studied. The medicinal chemistry of s-triazine derivatives as anticancer agents was summarized, including discovery, structure optimization, and biological applications. This review will provide a reference to inspire new and original discoveries.

Rapid exosome isolation and in situ multiplexed detection of exosomal surface proteins and microRNAs on microfluidic platform.

Exosomes are considered as promising biomarkers for early cancer diagnosis and prognosis. However, the majority of the research studies focused on a single type of exosomal biomarkers, which cannot comprehensively reflect the state of cancer for accurate diagnosis. To address this problem, we presented a ship-shaped microfluidic device containing a microcolumn array for simultaneous in situ detection of exosomal surface proteins and miRNAs. Exosomes were first captured in the microchannels modified with CD63 protein aptamer. Exosomal surface proteins and miRNAs were simultaneously detected in four parallel channels to avoid the interference of fluorescent signals using specific aptamers labeled by Cy5 and catalytic hairpin assembly (CHA) based signal amplification strategy. The limit of detection for multiplexed markers in exosomes was 83 exosomes per µL, which is comparable to previously reported methods. Through quantitative analysis of two disease-specific surface proteins and miRNAs derived from different cancer cells and clinical serum samples, different cancer subtypes as well as cancer patients and healthy people could be significantly distinguished. These results suggest that this simple, highly sensitive, and more accurate analytical strategy by simultaneous in situ profiling of different types of exosomal biomarkers has potential applications in cancer diagnosis and stage monitoring.

The Tetrahymena bcd1 mutant implicates endosome trafficking in ciliate, cortical pattern formation.

Ciliates, such as Tetrahymena thermophila, evolved complex mechanisms to determine both the location and dimensions of cortical organelles such as the oral apparatus (OA: involved in phagocytosis), cytoproct (Cyp: for eliminating wastes), and contractile vacuole pores (CVPs: involved in water expulsion). Mutations have been recovered in Tetrahymena that affect both the localization of such organelles along anterior-posterior and circumferential body axes and their dimensions. Here we describe BCD1, a ciliate pattern gene that encodes a conserved Beige-BEACH domain-containing protein a with possible protein kinase A (PKA)-anchoring activity. Similar proteins have been implicated in endosome trafficking and are linked to human Chediak-Higashi syndrome and autism. Mutations in the BCD1 gene broaden cortical organelle domains as they assemble during predivision development. The Bcd1 protein localizes to membrane pockets at the base of every cilium that are active in endocytosis. PKA activity has been shown to promote endocytosis in other organisms, so we blocked clathrin-mediated endocytosis (using "dynasore") and inhibited PKA (using H89). In both cases, treatment produced partial phenocopies of the bcd1 pattern mutant. This study supports a model in which the dimensions of diverse cortical organelle assembly-platforms may be determined by regulated balance between constitutive exocytic delivery and PKA-regulated endocytic retrieval of organelle materials and determinants.

Escherichia fergusonii bacteremia after esophagectomy: a case report and literature review.

We report the case of a 68-year-old man who experienced Escherichia fergusonii bacteremia after esophageal cancer surgery. The patient presented with complaints of abdominal pain persisting for 1 week. The patient was diagnosed with esophageal malignancy, which was confirmed by surgical exploration and pathological biopsy. The patient developed septic shock on postoperative day 12, and blood culture suggested the growth of E. fergusonii. After treatment with meropenem, the patient's clinical symptoms improved significantly, and the second culture was negative. In this paper, we discuss the characteristics, diagnosis, and treatment of E. fergusonii. E. fergusonii is rarely reported, and its pathogenesis, drug resistance, and potential effects have not been completely confirmed. Thus, this case report adds valuable knowledge to the literature on E. fergusonii.

A universal platform for one-pot detection of circulating non-coding RNA combining CRISPR-Cas12a and branched rolling circle amplification.

Multiple circulating non-coding RNAs (ncRNAs) in serum may serve as vital biomarkers for use in diagnosing early-stage colorectal cancer (CRC). Herein, a universal platform for one-pot detection of CRC-related ncRNAs was developed based on branched rolling circle amplification and CRISPR-Cas12a (BRCACas). For the implementation of the method, primers incorporating ncRNA sequences of circulating CRC-associated RNAs (piRNA or miRNA) were designed that could specifically hybridize with circular probes to initiate the BRCA process. Thereafter, the generation of dendritic DNA products triggered Cas12a trans-cleavage activity to elicit a fluorescent signal. The proposed method, combining high BRCA reaction efficiency with powerful Cas12a trans-cleavage activity, provided greatly enhanced detection sensitivity, as reflected by limits of detection (LODs) for model piRNA (piR-54265) and model miRNA (miR21) of 0.76 fM and 0.87 fM, respectively. Notably, the proposed BRCACas platform, assaying two different types of CRC-associated ncRNAs in patient samples, produced consistent results with the conventional reverse transcription-quantitative PCR (RT-qPCR) method. Therefore, the one-pot, isothermal, and specific BRCACas platform provided excellent performance, thus demonstrating its promise as a rapid, adaptable, and practical diagnostic/prognostic cancer screening method.

Simple Isothermal and Label-Free Strategy for Colorectal Cancer Potential Biomarker miR-625-5p Detection.

miRNA is considered a novel biomarker for cancer diagnosis and due to its low level in vivo, the development of new detection methods for it has become a research hotspot in recent years. Here, we firstly found that miR-625-5p was significantly upregulated in colorectal cancer tissues by means of differential expression analysis of the dbDEMC database and clinical validation. Subsequently, it was found that miR-625-5p promoted cell proliferation and migration but inhibited apoptosis through phenotypic experiments; thus, we initially identified miR-625-5p as a potential biomarker for colorectal cancer. Moreover, in order to monitor slight changes in the miR-625-5p level, we developed a novel detection method for it based on strand displacement amplification (SDA). In this system, a hairpin was designed to recognize and pair with miR-625-5p, which was used as a primer to initiate SDA, and a large number of complementary DNAs were generated via cyclic amplification, followed by the addition of SYBR Gold to achieve quantitative analysis of miR-625-5p. Moreover, this method showed a good response to miR-625-5p with a detection limit of 8.6 pM and a dynamic range of 0.01 to 200 nM, and the specificity of it was verified using a set of other miRNAs as an interference. Finally, we set up different concentrations of biologic samples for detection to verify the practicability of the method. The results of this study indicate that this detection method has great potential in clinical diagnosis.

MicroRNA-455-3p accelerate malignant progression of tumor by targeting H2AFZ in colorectal cancer.

Colorectal cancer (CRC) becomes the second leading cause of cancer-related deaths in 2020. Emerging studies have indicated that microRNAs (miRNAs) play a key role in tumorigenesis and progression. The dysfunctions of miR-455-3p are observed in many cancers. However, its biological function in CRC remains to be confirmed. By sequencing serum sample, miR-455-3p was found to be up-regulated in CRC patients. RT-qPCR demonstrated that the miR-455-3p expression was both higher in the serum and tumor tissues of CRC patients. Furthermore, it indicated that miR-455-3p had the ability in promoting cell proliferation, suppressing cell apoptosis, and stimulating cell migration. In vivo experiments also showed that miR-455-3p promoted tumor growth. Additionally, H2AFZ was proved as the direct gene target of miR-455-3p by dual-luciferase assay. Taken together, miR-455-3p functioned as a tumor promoter in CRC development by regulating H2AFZ directly. Thus, it has enormous potential as a biomarker in the diagnosis of CRC.