ZEB1-regulated lnc-Nr2f1 promotes the migration and invasion of lung adenocarcinoma cells

SNX30 inhibits lung adenocarcinoma cell proliferation and induces cell ferroptosis through regulating SETDB1

BACKGROUND

Lung adenocarcinoma is the most common form of lung cancer and one of the most life-threatening malignant tumors. Ferroptosis is an iron-dependent regulatory cell death pathway that is crucial for tumor growth. SNX30 is a key regulatory factor in cardiac development; however, its regulatory mechanism and role in inducing ferroptosis in lung adenocarcinoma remain unclear.

OBJECTIVE

This study aimed to elucidate the functions and specific mechanisms of action of SNX30 in lung adenocarcinomas.

METHODS

SNX30 levels in lung adenocarcinoma cell lines (A549 and HCC827) were determined using reverse transcription quantitative real-time PCR (RT-qPCR) or western blotting. Cell proliferation and apoptosis were assessed by CCK8 and flow cytometry, respectively. The intracellular levels of total iron and Fe2+ were detected using Iron Assay Kits. Reactive oxygen species (ROS) levels were evaluated using a DCFH-DA probe and flow cytometry. Cysteine (Cys), glutathione (GSH), and glutathione peroxidase 4 (GPX4) levels were measured using detection assay kits. Other related markers, including Ptgs2, Chac1, SETDB1 cleaved-Caspase3, and Caspase3 were analyzed by RT-qPCR or western blotting.

RESULTS

SNX30 is downregulated in lung adenocarcinoma cell lines. SNX30-plasmid depressed lung adenocarcinoma cell proliferation, accelerated apoptosis, enhanced cleaved-Caspase3 expression and cleaved-Caspase3/Caspase3 ratio. Ferrostatin-1 significantly reversed the effects of the SNX30-plasmid on cell ferroptosis in lung adenocarcinoma, as confirmed by the reduced ROS levels, inhibited intracellular total iron and Fe2+ levels, decreased Ptgs2 and Chac1 expression, and increased Cys, GSH, and GPX4 release. We observed that the level of SETDB1 was lower in the SNX30-plasmid group than in the control-plasmid group, whereas the opposite results in ferrostatin-1 treated cells. SNX30 negatively regulates SETDB1 expression in lung adenocarcinoma cells. The upregulation of SETDB1 reversed the effects of the SNX30-plasmid on ferroptosis in lung adenocarcinoma cells.

CONCLUSION

SNX30 inhibits lung adenocarcinoma cell proliferation and induces ferroptosis by regulating SETDB1 expression.

Exosome-delivered NR2F1-AS1 and NR2F1 drive phenotypic transition from dormancy to proliferation in treatment-resistant prostate cancer via stabilizing hormonal receptors

Cancer cells acquire the ability to reprogram their phenotype in response to targeted therapies, yet the transition from dormancy to proliferation in drug-resistant cancers remains poorly understood. In prostate cancer, we utilized high-plasticity mouse models and enzalutamide-resistant (ENZ-R) cellular models to elucidate NR2F1 as a key factor in lineage transition and ENZ resistance. Depletion of NR2F1 drives ENZ-R cells into a relative dormancy state, characterized by reduced proliferation and heightened drug resistance, while NR2F1 overexpression yields contrasting outcomes. Transcriptional sequencing analysis of NR2F1-silenced prostate cancer cells and tissues from the Cancer Genome Atlas-prostate cancer and SU2C cohorts indicated exosomes as the most enriched cell component, with pathways implicated in steroid hormone biosynthesis and drug metabolism. Moreover, NR2F1-AS1 forms a complex with SRSF1 to upregulate NR2F1 expression, facilitating its binding with ESR1 to sustain hormonal receptor expression and enhance proliferation in ENZ-R cells. Furthermore, HnRNPA2B1 interacts with NR2F1 and NR2F1-AS1, assisting their packaging into exosomes, wherein exosomal NR2F1 and NR2F1-AS1 promote the proliferation of dormant ENZ-R cells. Our works offer novel insights into the reawaking of dormant drug-resistant cancer cells governed by NR2F1 upregulation triggered by exosome-derived NR2F1-AS1 and NR2F1, suggesting therapeutic potential for phenotype reversal.

Blocking Tryptophan Catabolism Reduces Triple-Negative Breast Cancer Invasive Capacity

SIGNIFICANCE

TDO2 is more highly expressed than the nonhomologous TRP-catabolizing enzyme IDO1 in TNBC. We find that TDO2 knockdown can lead to a compensatory increase in IDO1. Therefore, we tested a newly developed TDO2/IDO1 dual inhibitor and found that it decreases TRP catabolism, anchorage-independent survival, and invasive capacity.

The Zeb1-Cxcl1 axis impairs the antitumor immune response by inducing M2 macrophage polarization in breast cancer

Zeb1, a key epithelial-mesenchymal transition (EMT) regulator, has recently been found to be involved in M2 macrophage polarization in the tumor immune microenvironment, thereby promoting tumor development. However, the underlying mechanism of Zeb1-induced M2 macrophage polarization remains largely unexplored. To identify the potential role of Zeb1 in remodeling the tumor immune microenvironment in breast cancer, we crossed the floxed Zeb1 allele homozygously into PyMT mice to generate PyMT;Zeb1cKO (MMTV-Cre;PyMT;Zeb1fl/fl ) mice. We found that the recruitment of M2-type tumor-associated macrophages (TAMs) was significantly reduced in tumors from PyMT;Zeb1cKO mice, and their tumor suppressive effects were weakened. Mechanistically, Zeb1 played a crucial role in transcriptionally promoting the production of Cxcl1 in tumor cells. In turn, Cxcl1 activated the Cxcr2-Jak-Stat3 pathway to induce M2 polarization of TAMs in a paracrine manner, which eventually led to T-cell inactivation and impaired the antitumor immune response in breast cancer. Our results collectively revealed an important role of Zeb1 in remodeling the tumor microenvironment, suggesting a novel therapeutic intervention for the treatment of advanced breast cancer.

Roles of the NR2F Family in the Development, Disease, and Cancer of the Lung

The NR2F family, including NR2F1, NR2F2, and NR2F6, belongs to the nuclear receptor superfamily. NR2F family members function as transcription factors and play essential roles in the development of multiple organs or tissues in mammals, including the central nervous system, veins and arteries, kidneys, uterus, and vasculature. In the central nervous system, NR2F1/2 coordinate with each other to regulate the development of specific brain subregions or cell types. In addition, NR2F family members are associated with various cancers, such as prostate cancer, breast cancer, and esophageal cancer. Nonetheless, the roles of the NR2F family in the development and diseases of the lung have not been systematically summarized. In this review, we mainly focus on the lung, including recent findings regarding the roles of the NR2F family in development, physiological function, and cancer.

NR2F1 overexpression alleviates trophoblast cell dysfunction by inhibiting GDF15/MAPK axis in preeclampsia

Abnormal functions of trophoblast cells are associated with the pathogenesis of preeclampsia (PE). Nuclear receptor subfamily 2 group F member 1 (NR2F1) acts as a transcriptionally regulator in many diseases, but its role in PE remains unknown. Hypoxia/reoxygenation (H/R)-stimulated HTR-8/SVneo cells were used to mimic PE injury in vitro. NR2F1 overexpression alleviated trophoblast apoptosis, as evidenced by the decreased number of TUNEL-positive cells and the downregulation of caspase 3 and caspase 9 expression in cells. NR2F1 overexpression increased the invasion and migration ability of HTR-8/SVneo cells, accompanied by increased protein levels of matrix metalloproteinase (MMP)-2 and MMP-9. mRNA-seq was applied to explore the underlying mechanism of NR2F1, identifying growth differentiation factor 15 (GDF15) as the possible downstream effector. Dual-luciferase reporter, ChIP-qPCR, and DNA pull-down assays confirmed that NR2F1 bound to the promoter of GDF15 and transcriptionally inhibited its expression. GDF15 overexpression increased apoptosis and decreased the ability of invasion and migration in HTR-8/SVneo cells expressing NR2F1. MAPK pathway was involved in the regulation of PE. Administration of p38 inhibitor, ERK inhibitor, and JNK inhibitor reversed the effect of simultaneous overexpression NR2F1 and GDF15 on trophoblast apoptosis, invasion, and migration. Our findings demonstrated that NR2F1 overexpression inhibited trophoblast apoptosis and promoted trophoblast invasion and migration. NR2F1 might negatively regulate GDF15 expression by binding to its promoter region, which further inhibited MAPK signaling pathway in PE. Our study highlights that NR2F1 might sever as a potential target in PE.

miR-200-mediated inactivation of cancer-associated fibroblasts via targeting of NRP2-VEGFR signaling attenuates lung cancer invasion and metastasis

Cancer-associated fibroblasts (CAFs) play a substantial role in promoting cancer cell motility, drug resistance, angiogenesis, and metastasis; therefore, extensive research has been conducted to determine their mode of activation. We aimed to identify whether miRNA-200 (miR-200), a widely recognized suppressor of epithelial-mesenchymal transition, prevents CAFs from promoting cancer progression. Overexpression of miR-200 prevented CAFs from promoting lung cancer cell migration, invasion, tumorigenicity, and metastasis. Additionally, miR-200 suppressed the ability of CAFs to recruit and polarize macrophages toward the M2 phenotype, as well as the migration and tube formation of vascular endothelial cells. NRP2, a co-receptor of vascular endothelial growth factor receptor (VEGFR), was confirmed to be a target of miR-200, which mediates the functional activity of miR-200 in CAFs. NRP2-VEGFR signaling facilitates the secretion of VEGF-D and pleiotrophin from CAFs, leading to the activation of cancer cell migration and invasion. These findings suggest that miR-200 remodels CAFs to impede cancer progression and metastasis and that miR-200 and NRP2 are potential therapeutic targets in the treatment of lung cancer.

Inhibition of PD-L1 expression in non-small cell lung cancer may reduce vasculogenic mimicry formation by inhibiting the epithelial mesenchymal transformation process

Non-small cell lung cancer (NSCLC) is a kind of highly malignant tumor. Studies have shown that Vasculogenic mimicry (VM) may be responsible for dismal prognosis in NSCLC. Immunotherapy with programmed death-1 (PD-1) or programmed death ligand-1 (PD-L1) has significantly altered the treatment of assorted cancers, including NSCLC, but its role and mechanism in the formation of Vasculogenic mimicry (VM) in NSCLC remains unclear. This study aimed to investigate the role of the anti-PD-L1 antibody in the formation of VM in NSCLC and its possible mechanisms. The results showed that anti-PD-L1 antibody therapy could inhibit the growth of NSCLC-transplanted tumors and reduce the formation of VMs. In addition, this study found that anti-PD-L1 antibodies could increase the expression of the epithelial-mesenchymal transition (EMT) related factor E-cadherin. zinc finger E-box binding homeobox 1 (ZEB1) is an important transcription factor regulating EMT. Knocking down ZEB1 could significantly inhibit tumor growth, as well as the expression of VE-cadherin and mmp2, while remarkably increase the expression of E-cadherin. During this process, the formation of VM was inhibited by knowing down ZEB1 in both in vitro and in vivo experiments of the constructed ZEB1 knockdown stable transfected cell strains. Therefore, in this study, we found that anti-PD-L1 antibodies may reduce the formation of VMs by inhibiting the EMT process.

Compound AC1Q3QWB upregulates CDKN1A and SOX17 by interrupting the HOTAIR-EZH2 interaction and enhances the efficacy of tazemetostat in endometrial cancer

Endometrial cancer (EC) is a common malignancy of the female reproductive system, with an escalating incidence. Recurrent/metastatic EC presents a poor prognosis. The interaction between the long non-coding RNA (lncRNA) HOTAIR and the polycomb repressive complex 2 (PRC2) induces abnormal silencing of tumor suppressor genes, exerting a pivotal role in tumorigenesis. We have previously discovered AC1Q3QWB (AQB), a small-molecule compound targeting HOTAIR-EZH2 interaction. In the present study, we unveil that AQB selectively hampers the interaction between HOTAIR and EZH2 within EC cells, thus reversing the epigenetic suppression of tumor suppressor genes. Furthermore, our findings demonstrate AQB's synergistic effect with tazemetostat (TAZ), an EZH2 inhibitor, significantly boosting the expression of CDKN1A and SOX17. This, in turn, induces cell cycle arrest and impedes EC cell proliferation, migration, and invasion. In vivo experiments further validate AQB's potential by enhancing TAZ's anti-tumor efficacy at lower doses. Our results advocate AQB, a recently discovered small-molecule inhibitor, as a promising agent against EC cells. When combined with TAZ, it offers a novel therapeutic strategy for EC treatment.