As a catalytic subunit of the positive transcription elongation factor b (P-TEFb), cyclin-dependent kinase 9 (CDK9) has been demonstrated to contribute to carcinogenesis. This review focuses on the development of selective CDK9 inhibitors and proteolysis-targeting chimera (PROTAC) degraders. Twenty selective CDK9 inhibitors and degraders are introduced along with their structures, IC50 values, in vitro and in vivo experiments, mechanisms underlying their inhibitory effects, and combination regimens. NVP-2, MC180295, fadraciclib, KB-0742, LZT-106, and 21e have been developed mainly for treating solid tumors, and most of them work only on certain genotypes of solid tumors. Only VIP152 has been proven to benefit the patients with advanced high-grade lymphoma (HGL) and solid tumors in clinical trials. Continued efforts to explore the molecular mechanisms underlying the inhibitory effects, and to identify suitable tumor genotypes and combination treatment strategies, are crucial to demonstrate the efficacy of selective CDK9 inhibitors and degraders in tumor therapy.

ICG-001, a small molecule, binds CREB-binding protein (CBP) to disrupt its interaction with β-catenin and inhibits CBP function as a co-activator of Wnt/β-catenin-mediated transcription. Given its ability to inhibit Wnt/β-catenin signaling pathway, ICG-001 has been used in some tumor types to exert its anticarcinogenic effect. Here, we examined ICG-001 and its potential role as a therapeutic in gastric cancer (GC). The gastric cancer cell lines SGC-7901, MGC-803, BGC-823 and MKN-45 were used in vitro and in vivo. The abilities of cell proliferation, tumor sphere formation, metastasis, tumorgenesis and chemoresistance to chemotherapy drugs in vitro were evaluated by MTT assay, colony formation assay, flow cytometry, migration and invasion assay, and tumor spheres culture. The in vivo experiments were performed using a subcutaneous transplantation tumor model in athymic nude mice. Alterations at RNA and protein levels were followed by qRT-PCR, western blot, coimmunoprecipitations and immunofluorescence assay. In this study, we showed that ICG-001 significantly inhibited growth and metastasis of multiple GC cell lines, induced cell apoptosis, and augmented in vitro tumor spheres suppression when used in combination with chemotherapy drugs probably through robustly blocking association of β-catenin with CBP and N-cadherin, but promoting association of β-catenin with P300 and E-cadherin, instead of altering the distribution and expression of β-catenin. Our findings suggest that ICG-001 suppresses GC cell line growth, metastasis and reduces its stem cell-like properties and chemoresistance, indicating that ICG-001 is a potentially useful small molecule therapeutic for GC.

Gastric cancer stem cells (GCSCs) play a crucial role in the initiation, progression, recurrence and therapeutic resistance, contributing to a poor prognosis. Consequently, GCSCs are deemed to be a potential therapeutic target for gastric cancer (GC). Although β-catenin is a well-recognized therapeutic target for GC and several inhibitors have demonstrated potent anti-tumor effects, there is a dearth of therapeutic agents targeting β-catenin for clinical therapy. In this study, we carried out high-throughput screening of clinically approved drugs to identify effective inhibitors of β-catenin. The results revealed that the antibiotic drug, clofoctol (CFT) effectively reduced the β-catenin level, attenuated stemness traits both in vitro and in vivo, and induced necroptosis of GCSCs. Further analyzing of downstream genes and targeted proteins, we found that CFT inhibited GCSCs viability by binding to the SUMO E3 ligase RanBP2, thereby suppressing the SerpinE1/β-catenin axis and activating TNF-mediated necroptosis. These results indicate that CFT may exert potent therapeutic effects against GC by targeting β-catenin and inhibiting the viability of GCSCs.

Background: Gastric cancer (GC) is considered a highly heterogeneous disease, and currently, a comprehensive approach encompassing molecular data from various biological levels is lacking.Methods: This study conducted different analyses, including the identification of differentially expressed genes (DEGs), weighted correlation networks (WGCNA), single‐cell RNA sequencing (scRNA‐seq), mRNA expression‐based stemness index (mRNAsi), and multiCox analysis, utilizing data from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Subsequently, the machine learning algorithms including least absolute shrinkage and selection operator (LASSO) regression and random forest (RF), combined with multiCox analysis were exploited to identify hub genes. These findings were then validated through the receiver operating characteristic (ROC) curve and Kaplan–Meier analysis, and were experimentally confirmed in GC samples by reverse transcription–polymerase chain reaction (RT‐PCR) and enzyme‐linked immunosorbent assay (ELISA).Results: Integrated analysis of TCGA and GEO databases, coupled with LASSO regression and RF algorithms, allowed us to identify 18 hub genes encoding differentially expressed secreted proteins in GC. The results of RT‐PCR and bioinformatics analysis revealed four promising biomarkers with optimal diagnostic and prognostic potential. ROC analysis and Kaplan–Meier curves highlighted CHI3L1, FCGBP, VSIG2, and TFF2 as promising biomarkers for GC, offering superior modeling accuracy. These findings were further confirmed by RT‐PCR and ELISA, affirming the clinical utility of these four biomarkers. Additionally, CIBERSORT analysis indicated a potential correlation between the four biomarkers and the infiltration of B memory cells and Treg cells.Conclusion: This study unveiled four promising biomarkers present in the serum of patients with GC, which could serve as powerful indicators of GC and provide valuable insights for further research into GC pathogenesis.

Proteinuria serves as a critical indicator in the progression of chronic kidney disease. The quantification of urinary protein is instrumental in diagnosing kidney disease and monitoring therapeutic efficacy. Nephelometry and turbidimetric immunoassay are predominantly employed for the quantitative detection of various urinary proteins. We developed a quantitative detection method for six proteins in urine utilizing the flow fluorescence luminescence method on the Luminex®200™ detection platform. This study aims to evaluate the clinical performance and accuracy of the method. The sensitivity, precision, recovery, linearity, and interference metrics for the method meet the needs of clinical applications. The correlation coefficient (r) between the results of the method and nephelometry immunoassay on SIEMENS BNII platform ranged from 0.9375 to 0.9847, indicating a strong linear relationship. The results of the Bland-Altman analysis indicated that the systematic bias between the two methods was minimal. Additionally, Passing-Bablok regression analysis, both including and excluding outliers, was conducted on the clinical trial data. The findings demonstrated consistency between the two methods, with the expected confidence interval of bias remaining within the allowable error limits, indicating no significant discrepancy. This urine six protein quantification method demonstrates satisfactory performance, meeting the standards necessary for medical diagnosis and clinical application.