Homo- or heterodimeric compounds that affect dimeric protein function through interaction between monomeric moieties and protein subunits can serve as valuable sources of potent and selective drug candidates. Here, we screened an in-house dimeric natural product collection, and panepocyclinol A (PecA) emerged as a selective and potent STAT3 inhibitor with profound anti-tumor efficacy. Through cross-linking C712/C718 residues in separate STAT3 monomers with two distinct Michael receptors, PecA inhibits STAT3 DNA binding affinity and transcription activity. Molecular dynamics simulation reveals the key conformation changes of STAT3 dimers upon the di-covalent binding with PecA that abolishes its DNA interactions. Furthermore, PecA exhibits high efficacy against anaplastic large T cell lymphoma in vitro and in vivo, especially those with constitutively activated STAT3 or STAT3^Y640F. In summary, our study describes a distinct and effective di-covalent modification for the dimeric compound PecA to disrupt STAT3 function.

Kirsten rat sarcoma viral oncogene homolog (KRAS) protein inhibitors are a promising class of therapeutics, but research on molecules that effectively penetrate the blood-brain barrier (BBB) remains limited, which is crucial for treating central nervous system (CNS) malignancies. Although molecular generation models have recently advanced drug discovery, they often overlook the complexity of biological and chemical factors, leaving room for improvement. In this study, we present a structure-constrained molecular generation workflow designed to optimize lead compounds for both drug efficacy and drug absorption properties. Our approach utilizes a variational autoencoder (VAE) generative model integrated with reinforcement learning for multi-objective optimization. This method specifically aims to enhance BBB permeability (BBBp) while maintaining high-affinity substructures of KRAS inhibitors. To support this, we incorporate a specialized KRAS BBB predictor based on active learning and an affinity predictor employing comparative learning models. Additionally, we introduce two novel metrics, the knowledge-integrated reproduction score (KIRS) and the composite diversity score (CDS), to assess structural performance and biological relevance. Retrospective validation with KRAS inhibitors, AMG510 and MRTX849, demonstrates the framework's effectiveness in optimizing BBBp and highlights its potential for real-world drug development applications. This study provides a robust framework for accelerating the structural enhancement of lead compounds, advancing the drug development process across diverse targets.

Objective:To investigate the effect of FOXQ1 expression on chemoresistance in colorectal cancer and analyze its regulatory role in SIRT1 expression and p53 deacetylation under DNA damage response(DDR)condi-tions.Methods:qRT-PCR was used to detect FOXQ1 mRNA expression levels in SW620 cells and SW620 cells stimulated with cisplatin(CDDP).Lentiviral vectors were constructed for FOXQ1 overexpression and RNA interference.The cells were divided into three groups:FOXQ1 overexpression group(oe-FOXQ1),FOXQ1 RNA interference group(sh-FOXQ1),and a control group transfected with an empty vector(NC).The half-maximal inhibitory concentration(IC50)of CDDP in each group was determined using the CCK-8 assay.Apoptosis level and cell viability were assessed using the Annexin V-APC/7-ADD apoptosis detection kit and Calcein/PI staining.Western blot analysis was performed to evaluate the effect of FOXQ1 on SIRT1 expression and acetylated p53 levels.The SIRT1 pathway inhibitor(S)-Selisi-stat was introduced to observe changes in p53 acetylation levels.Results:Compared to normal colon tissues,FOXQ1 expression was significantly upregulated in SW620 cells(P＜0.05),and low-dose CDDP stimulation further en-hanced its expression(P＜0.05).After 24 hours of CDDP treatment,the IC50 values for the oe-FOXQ1,sh-FOXQ1,and NC groups were 58.3 μmol/L,36.4 μmol/L,and 43.7 μmol/L,respectively,with statistically significant differences among the groups(P＜0.05).Compared to the NC group,the oe-FOXQ1 group showed a decrease in late apoptotic cell count(P＜0.05),while the sh-FOXQ1 group exhibited an increase(P＜0.05).Cytotoxic fluorescence staining re-vealed that the proportion of cell death was lower in the oe-FOXQ1 group and higher in the sh-FOXQ1 group com-pared to the NC group(P＜0.05).Protein expression analysis showed that FOXQ1 and SIRT1 levels were higher in the oe-FOXQ1 group and lower in the sh-FOXQ1 group compared to the NC group(P＜0.05).FOXQ1 overexpression pro-moted p53 deacetylation,while the addition of the SIRT1 pathway inhibitor(S)-Selisistat restored p53 acetylation levels(P＜0.05).Conclusion:FOXQ1 promotes p53 deacetylation by upregulating SIRT1 expression,thereby inhibiting DDR-induced apoptosis.

Kirsten rat sarcoma viral oncogene homolog(KRAS)protein inhibitors are a promising class of thera-peutics,but research on molecules that effectively penetrate the blood-brain barrier(BBB)remains limited,which is crucial for treating central nervous system(CNS)malignancies.Although molecular generation models have recently advanced drug discovery,they often overlook the complexity of bio-logical and chemical factors,leaving room for improvement.In this study,we present a structure-constrained molecular generation workflow designed to optimize lead compounds for both drug effi-cacy and drug absorption properties.Our approach utilizes a variational autoencoder(VAE)generative model integrated with reinforcement learning for multi-objective optimization.This method specifically aims to enhance BBB permeability(BBBp)while maintaining high-affinity substructures of KRAS in-hibitors.To support this,we incorporate a specialized KRAS BBB predictor based on active learning and an affinity predictor employing comparative learning models.Additionally,we introduce two novel metrics,the knowledge-integrated reproduction score(KIRS)and the composite diversity score(CDS),to assess structural performance and biological relevance.Retrospective validation with KRAS inhibitors,AMG510 and MRTX849,demonstrates the framework's effectiveness in optimizing BBBp and highlights its potential for real-world drug development applications.This study provides a robust framework for accelerating the structural enhancement of lead compounds,advancing the drug development process across diverse targets.

Tumor drug resistance is an important problem in the failure of chemotherapy and targeted drug therapy, which is a complex process involving chromatin remodeling. SWI/SNF is one of the most studied ATP-dependent chromatin remodeling complexes in tumorigenesis, which plays an important role in the coordination of chromatin structural stability, gene expression, and post-translation modification. However, its mechanism in tumor drug resistance has not been systematically combed. SWI/SNF can be divided into 3 types according to its subunit composition: BAF, PBAF, and ncBAF. These 3 subtypes all contain two mutually exclusive ATPase catalytic subunits (SMARCA2 or SMARCA4), core subunits (SMARCC1 and SMARCD1), and regulatory subunits (ARID1A, PBRM1, and ACTB, etc.), which can control gene expression by regulating chromatin structure. The change of SWI/SNF complex subunits is one of the important factors of tumor drug resistance and progress. SMARCA4 and ARID1A are the most widely studied subunits in tumor drug resistance. Low expression of SMARCA4 can lead to the deletion of the transcription inhibitor of the BCL2L1 gene in mantle cell lymphoma, which will result in transcription up-regulation and significant resistance to the combination therapy of ibrutinib and venetoclax. Low expression of SMARCA4 and high expression of SMARCA2 can activate the FGFR1-pERK1/2 signaling pathway in ovarian high-grade serous carcinoma cells, which induces the overexpression of anti-apoptosis gene BCL2 and results in carboplatin resistance. SMARCA4 deletion can up-regulate epithelial-mesenchymal transition (EMT) by activating YAP1 gene expression in triple-negative breast cancer. It can also reduce the expression of Ca²⁺ channel IP3R3 in ovarian and lung cancer, resulting in the transfer of Ca²⁺ needed to induce apoptosis from endoplasmic reticulum to mitochondria damage. Thus, these two tumors are resistant to cisplatin. It has been found that verteporfin can overcome the drug resistance induced by SMARCA4 deletion. However, this inhibitor has not been applied in clinical practice. Therefore, it is a promising research direction to develop SWI/SNF ATPase targeted drugs with high oral bioavailability to treat patients with tumor resistance induced by low expression or deletion of SMARCA4. ARID1A deletion can activate the expression of ANXA1 protein in HER2+ breast cancer cells or down-regulate the expression of progesterone receptor B protein in endometrial cancer cells. The drug resistance of these two tumor cells to trastuzumab or progesterone is induced by activating AKT pathway. ARID1A deletion in ovarian cancer can increase the expression of MRP2 protein and make it resistant to carboplatin and paclitaxel. ARID1A deletion also can up-regulate the phosphorylation levels of EGFR, ErbB2, and RAF1 oncogene proteins.The ErbB and VEGF pathway are activated and EMT is increased. As a result, lung adenocarcinoma is resistant to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Although great progress has been made in the research on the mechanism of SWI/SNF complex inducing tumor drug resistance, most of the research is still at the protein level. It is necessary to comprehensively and deeply explore the detailed mechanism of drug resistance from gene, transcription, protein, and metabolite levels by using multi-omics techniques, which can provide sufficient theoretical basis for the diagnosis and treatment of poor tumor prognosis caused by mutation or abnormal expression of SWI/SNF subunits in clinical practice.

Objective:To investigate the effect of FOXQ1 expression on chemoresistance in colorectal cancer and analyze its regulatory role in SIRT1 expression and p53 deacetylation under DNA damage response(DDR)condi-tions.Methods:qRT-PCR was used to detect FOXQ1 mRNA expression levels in SW620 cells and SW620 cells stimulated with cisplatin(CDDP).Lentiviral vectors were constructed for FOXQ1 overexpression and RNA interference.The cells were divided into three groups:FOXQ1 overexpression group(oe-FOXQ1),FOXQ1 RNA interference group(sh-FOXQ1),and a control group transfected with an empty vector(NC).The half-maximal inhibitory concentration(IC50)of CDDP in each group was determined using the CCK-8 assay.Apoptosis level and cell viability were assessed using the Annexin V-APC/7-ADD apoptosis detection kit and Calcein/PI staining.Western blot analysis was performed to evaluate the effect of FOXQ1 on SIRT1 expression and acetylated p53 levels.The SIRT1 pathway inhibitor(S)-Selisi-stat was introduced to observe changes in p53 acetylation levels.Results:Compared to normal colon tissues,FOXQ1 expression was significantly upregulated in SW620 cells(P＜0.05),and low-dose CDDP stimulation further en-hanced its expression(P＜0.05).After 24 hours of CDDP treatment,the IC50 values for the oe-FOXQ1,sh-FOXQ1,and NC groups were 58.3 μmol/L,36.4 μmol/L,and 43.7 μmol/L,respectively,with statistically significant differences among the groups(P＜0.05).Compared to the NC group,the oe-FOXQ1 group showed a decrease in late apoptotic cell count(P＜0.05),while the sh-FOXQ1 group exhibited an increase(P＜0.05).Cytotoxic fluorescence staining re-vealed that the proportion of cell death was lower in the oe-FOXQ1 group and higher in the sh-FOXQ1 group com-pared to the NC group(P＜0.05).Protein expression analysis showed that FOXQ1 and SIRT1 levels were higher in the oe-FOXQ1 group and lower in the sh-FOXQ1 group compared to the NC group(P＜0.05).FOXQ1 overexpression pro-moted p53 deacetylation,while the addition of the SIRT1 pathway inhibitor(S)-Selisistat restored p53 acetylation levels(P＜0.05).Conclusion:FOXQ1 promotes p53 deacetylation by upregulating SIRT1 expression,thereby inhibiting DDR-induced apoptosis.

From the perspective of the physiological basis of liver and kidney sharing the common source in traditional Chinese medicine(TCM),and by integrating the theory of kidney dominating bone,liver dominating tendon,and meridian sinew of TCM as well as the bone resorption and collapse theory,and non-uniform settlement theory and lower-limb musculoskeletal bowstring structure theory of modern orthopedics,the pathogenesis of osteonecrosis of the femoral head(ONFH)under the system of non-uniform settlement during bone resorption and multidimensional composite bowstring working in coordination with the theory of liver-kidney and muscle-bone was explored.The key to the TCM pathogenesis of ONFH lies in the deficiency of the liver and kidney,and then the imbalance of kidney yin-yang leads to the disruption of the dynamic balance of bone formation and bone resorption mediated by osteoblasts-osteoclasts,which manifests as the elevated level of bone metabolism and the enhancement of focal bone resorption in the femoral head,and then leads to the necrosis and collapse of the femoral head.It is considered that the kidney dominates bone,liver dominates tendon,and the tendon and bone together constitute the muscle-bone-joint dynamic and static system of the hip joint.The appearance of collapse destroys the originally balanced muscle-bone-joint system.Moreover,the failure of liver blood in the nourishment of muscles and tendons further exacerbates the imbalance of the soft tissues around the hip joint,accelerates the collapse of the muscle-bone-joint dynamic and static system,speeds up the process of femoral head collapse,and ultimately results in irreversible outcomes.Based on the above pathogenesis,the systematic integrative treatment of ONFH should be based on the TCM holistic concept,focuses on the focal improvement of internal and external blood circulation of the femoral head by various approaches,so as to rebuild the coordination of joint function.Moreover,attention should be paid to the physical constitution of the patients,and therapy of tonifying the kidney and regulating the liver can be used to restore the balance between osteogenesis and osteoblastogenesis,and to reconstruct the muscle-bone-joint system,so as to effectively delay or even prevent the occurrence of ONFH.

AIM To evaluate the quality of Beidougen Formula Granules.METHODS Fifteen batches of standard decoctions and three batches of formula granules were prepared,after which paste rate and contents,transfer rates of magnoflorine,daurisoline,dauricine were determined.HPLC specific chromatograms were established,and cluster analysis was adopted in chemical pattern recognition.RESULTS For three batches of formula granules,the paste rates were 15.1%-16.6%,the contents of magnoflorine,daurisoline,dauricine were 18.93-19.39,9.42-9.60,6.79-6.85 mg/g with the transfer rates of 34.42%-35.25%,43.81%-44.65%,27.27%-27.51%from decoction pieces to formula granules,respectively,and there were seven characteristic peaks in the specific chromatograms with the similarities of more than 0.95,which demonstrated good consistence with those of standard decoctions and accorded with related limit requirements.Fifteen batches of standard decoctions were clustered into two types,and the medicinal materials produced from Jilin,Hebei,Shangdong could be used for the preparation of formula granules.CONCLUSION This reasonable and reliable method can provide references for the quality control and clinical application of Beidougen Formula Granules.

Objective To study the in vitro expression of three phenylalanine hydroxylase(PAH)mutants(p.R243Q,p.R241C,and p.Y356X)and determine their pathogenicity.Methods Bioinformatics techniques were used to predict the impact of PAH mutants on the structure and function of PAH protein.Corresponding mutant plasmids of PAH were constructed and expressed in HEK293T cells.Quantitative reverse transcription polymerase chain reaction was used to measure the mRNA expression levels of the three PAH mutants,and their protein levels were assessed using Western blot and enzyme-linked immunosorbent assay.Results Bioinformatics analysis predicted that all three mutants were pathogenic.The mRNA expression levels of the p.R243Q and p.R241C mutants in HEK293T cells were similar to the mRNA expression level of the wild-type control(P>0.05),while the mRNA expression level of the p.Y356X mutant significantly decreased(P<0.05).The PAH protein expression levels of all three mutants were significantly reduced compared to the wild-type control(P<0.05).The extracellular concentration of PAH protein was reduced in the p.R241C and p.Y356X mutants compared to the wild-type control(P<0.05),while there was no significant difference between the p.R243Q mutant and the wild type control(P>0.05).Conclusions p.R243Q,p.R241C and p.Y356X mutants lead to reduced expression levels of PAH protein in eukaryotic cells,with p.R241C and p.Y356X mutants also affecting the function of PAH protein.These three PAH mutants are to be pathogenic.[Chinese Journal of Contemporary Pediatrics,2024,26(2):188-193]

Toll-like receptors(TLRs),key molecules initiating innate immune responses,serve as a bridge linking innate and adaptive immune responses.TLRs are transmembrane receptors expressed probably by natural immune cells,and are di-vided into cell surface and intracellular TLRs.Several studies have indicated that TLR agonists as adjuvants can enhance the im-mune protective effects of vaccines.Because of the complex life history of parasites and the differences in antigen characteristics among species or developmental stages in the same species,the research and development of parasite vaccines is challenging.Therefore,the development of effective and safe new adjuvants is crucial for improving the immune efficacy of parasite vac-cines.This article reviews the types and effects of TLR agonists,as well as their applications as adjuvants for parasitic vac-cines,to provide new ideas for the development of new parasitic vaccine adjuvants.