The proto-oncogene SRC phosphorylates cGAS to inhibit an antitumor immune response

A multiparametric screen uncovers FDA-approved small molecules that potentiate the nuclear mechano-dysfunctions in ATR-defective cells

Targeting nuclear mechanics is emerging as a promising therapeutic strategy for sensitizing cancer cells to immunotherapy. Inhibition of the mechano-sensory kinase ATR leads to mechanical vulnerability of cancer cells, causing nuclear envelope softness and collapse and activation of the cGAS-STING-mediated innate immune response. Finding novel compounds that interfere with the non-canonical role of ATR in controlling nuclear mechanics presents an intriguing therapeutic opportunity. We carried out a multiparametric high-content screen to identify small molecules that affect nuclear envelope shape and to uncover novel players that could either ameliorate or further compromise the nuclear mechanical abnormalities of ATR-defective cells. The screen was performed in HeLa cells genetically depleted for ATR. Candidate hits were also tested in combination with the chemical inhibition of ATR by AZD6738, and their efficacy was further validated in the triple-negative breast cancer cell lines BT549 and HCC1937. We show that those compounds enhancing the abnormal nuclear shape of ATR-defective cells also synergize with AZD6738 to boost the expression of interferon-stimulated genes, highlighting the power of multiparametric screens to identify novel combined therapeutic interventions targeting nuclear mechanics for cancer immunotherapy.

Exploring the Targets and Molecular Mechanisms of Curcumin for the Treatment of Bladder Cancer Based on Network Pharmacology, Molecular Docking and Molecular Dynamics

Curcumin, a phenolic compound derived from turmeric, has demonstrated anti-tumor properties in preclinical models of various cancers. However, the exact mechanism of curcumin in treating bladder cancer remains unclear. This study aimed to elucidate the therapeutic targets and molecular mechanisms of curcumin in the treatment of BC through an integrated approach of network pharmacology, molecular docking, and molecular dynamics simulations. PharmMapper, SuperPred, TargetNet, and SwissTargetPrediction were utilized to acquire targets associated with curcumin, while GeneCards, CTD, DisGeNET, OMIM, and PharmGKB databases were utilized to obtain targets related to bladder cancer. The drug-disease interaction targets were obtained using Venny 2.1.0, and GO and KEGG enrichment analyses were then conducted with the DAVID tool. We constructed a protein-protein interaction (PPI) network and identified tenkey targets. In conclusion, AutoDock Tools 1.5.7 was utilized to conduct molecular docking simulations, followed by additional analysis of the central targets through the GEPIA, HPA, cBioPortal, and TIMER databases. A total of 305 potential anticancer targets of curcumin were obtained. The analysis of GO functional enrichment resulted in a total of 1105 terms, including 786 terms related to biological processes (BP), 105 terms related to cellular components (CC), and 214 terms related to molecular functions (MF). In addition, KEGG pathway enrichment analysis identified 170 relevant signaling pathways. Treating bladder cancer could potentially involve inhibiting pathways like the PI3K-Akt signaling pathway, MAPK signaling pathway, EGFR tyrosine kinase inhibitor resistance, and IL-17 signaling pathway. Activating TNF, ALB, CASP3, and ESR1 while inhibiting AKT1, EGFR, STAT3, BCL2, SRC, and HSP90AA1 can also hinder the proliferation of bladder tumor cells. According to the results of molecular docking, curcumin binds to these central targets in a spontaneous manner, exhibiting binding energies lower than - 1.631 kJ/mol. These findings were further validated at the transcriptional, translational and immune infiltration levels. By utilizing network pharmacology and molecular docking techniques, it was discovered that curcumin possesses diverse effects on multiple targets and pathways for treating bladder cancer. It has the potential to impede the growth of bladder tumor cells by suppressing various pathways including the PI3K-Akt and MAPK signaling pathways, as well as pathways associated with EGFR tyrosine kinase inhibitor resistance and the IL-17 signaling pathway. Curcumin could potentially disrupt the cell cycle advancement in bladder cancer cells by increasing the expression of TNF, ALB, CASP3, and ESR1 while decreasing AKT1, EGFR, STAT3, BCL2, SRC, HSP90AA1, and other targeted genes. These findings reveal the possible molecular pathways through which curcumin exerts its anticancer effects in bladder cancer, and this novel research strategy not only provides an important basis for an in-depth understanding of the anticancer mechanism of curcumin, but also offers new potential drugs and targets for the clinical treatment of bladder cancer. Therefore, this study is of great scientific significance and practical application value for promoting the development of bladder cancer therapeutic field. This finding provides strong support for the development of novel, safe and effective drugs for bladder cancer treatment.

Advancements in tyrosine kinase-mediated regulation of innate nucleic acid sensing

Innate nucleic acid sensing is a ubiquitous and highly conserved immunological process, which is pivotal for monitoring and responding to pathogenic invasion and cellular damage, and central to host defense, autoimmunity, cell fate determination and tumorigenesis. Tyrosine phosphorylation, a major type of post-translational modification, plays a critical regulatory role in innate immune sensing pathway. Core members of nucleic acid sensing signaling pathway, such as cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS), stimulator of interferon genes (STING), and TANK binding kinase 1 (TBK1), are all subject to activity regulation triggered by tyrosine phosphorylation, thereby affecting the host antiviral defense and anti-tumor immunity under physiological or pathological conditions. This review summarizes the recent advances in research on tyrosine kinases and tyrosine phosphorylation in regulation of nucleic acid sensing. The function and potential applications of targeting tyrosine phosphorylation in anti-tumor immunity is disussed to provide insights for understanding and expanding new anti-tumor strategies.

KRAS mutations promote the intratumoral colonization of enterotoxigenic bacteroides fragilis in colorectal cancer through the regulation of the miRNA3655/SURF6/IRF7/IFNβ axis

KRAS mutations are associated with poor prognosis in colorectal cancer (CRC). Although the association between the gut microbiota and CRC has been extensively documented, it is unclear whether KRAS mutations can regulate the gut microbiota. Metagenomics has identified changes in the diversity of the gut microbiota in CRC due to KRAS mutations. Specifically, KRAS mutations positively correlate with the abundance of the bacteroides. Understanding how to regulate the classic carcinogenic bacterium within the bacteroides, such as enterotoxigenic bacteroides fragilis (ETBF), to enhance treatment efficacy of tumors is a key focus of research. Mechanistically, we found that the reduction of miR3655 is indispensable for KRAS mutation-promoted proliferation of CRC and the abundance of ETBF. miR3655 targets SURF6 to inhibit its transcription. Further transcriptomic sequencing revealed that SURF6 promotes intratumoral colonization of ETBF in CRC by inhibiting the nuclear translocation and transcription levels of the IRF7, affecting the activation of the IFNβ promoter. Regulating miR3655 and SURF6 can promote IFNβ secretion in CRC, directly killing ETBF. These data indicate that KRAS mutations affect the intratumoral colonization of ETBF in CRC through the miR3655/SURF6/IRF7/IFNβ axis. This provides new potential strategies for treating CRC associated with KRAS mutations or high levels of ETBF.