Circ_0003159 upregulates LIFR expression through competitively binding to miR-221-3p/miR-222-3p to block gastric cancer development

Expression of microRNAs related to apoptosis in the aqueous humor and lens capsule of patients with glaucoma

Background

The aim of this study is to investigate the expression profiles of microRNAs (miRNAs) related to apoptosis in the aqueous humor (AH) and lens capsule (LC) of patients with glaucoma.

Methods

AH and LC samples were collected from patients with open-angle glaucoma and control participants who were scheduled for cataract surgery. A miRNA PCR array comprising 84 miRNAs was used to analyze the AH (glaucoma, n = 3; control, n = 3) and LC samples (glaucoma, n = 3; control, n = 4). Additionally, the AH and LC samples (glaucoma, n = 3; control, n = 4) were subjected to quantitative real-time PCR to validate the differentially expressed miRNAs determined using the PCR array. Bioinformatics analysis was performed to identify the interactions between miRNAs and diseases. Additionally, the differential expression of these miRNAs and the target gene was validated through in vitro experiments using a retinal ganglion cell (RGC) model.

Results

Expression levels of 19 and 3 miRNAs were significantly upregulated in the AH and LC samples of the glaucoma group, respectively (p < 0.05). Of these, the expression levels of hsa-miR-193a-5p and hsa-miR-222-3p showed significant differences in both AH and LC samples. Bioinformatics analysis showed experimentally validated 8 miRNA:gene pairs. Among them, PTEN was selected to analyze the expression level in AH and LC from separate cohort (glaucoma, n = 5; control, n = 4). The result showed downregulation of PTEN concurrent with upregulation of the two miRNAs in LC samples of glaucoma group. In vitro experiments validated that the expression levels of hsa-miR-193a-5p and hsa-miR-222-3p were significantly upregulated, and that of PTEN was significantly downregulated in the H2O2-treated RGC, while the level of PTEN was recovered through co-treatment with miR-193a inhibitor or miR-222 inhibitor.

Conclusion

This is the first study to investigate the differential expression of apoptosis-related miRNAs in the AH and LC of patients with glaucoma. Hsa-miR-193a-5p and hsa-miR-222-3p, which were upregulated in both AH and LC, may be considered potential biomarkers for glaucoma.

Downregulation of miR-221-3p promotes the ferroptosis in gastric cancer cells via upregulation of ATF3 to mediate the transcription inhibition of GPX4 and HRD1

BACKGROUND

Gastric cancer (GC) is an aggressive gastrointestinal tumor. MiRNAs participate in the tumorigenesis of GC. Nevertheless, the function of miR-221-3p in GC remains largely unknown.

METHODS

RNA levels were assessed by RT-qPCR. Western blot was performed to test the protein levels. The relation between miR-221-3p and ATF3 was investigated by dual-luciferase reporter assay. ChIP and dual-luciferase reporter assay were applied to assess the interaction between ATF3 and HRD1 or GPX4. Meanwhile, cell proliferation was investigated by CCK8 and colony formation assay. The content of erastin-induced Fe²⁺ was investigated by iron assay kit. Erastin-induced lipid ROS level was assessed by C11-BODIPY 581/591. Co-immunoprecipitation was used to detect the interaction between HRD1 and ACSL4. In addition, xenograft mice model was established to detect the effect of miR-221-3p in GC.

RESULTS

Depletion of miR-221-3p greatly attenuated GC cell proliferation through promoting ferroptosis. Meanwhile, ATF3 was downregulated in GC, and it was identified to be the downstream mRNA of miR-221-3p. MiR-221-3p downregulation could promoted the ferroptosis in GC cells through upregulation of ATF3. HRD1 mediates ubiquitination and degradation of ACSL4 to inhibit ferroptosis. ATF3 upregulation could reduce GC cell proliferation via downregulating the transcription of GPX4 and HRD1. Furthermore, downregulation of miR-221-3p markedly attenuated the growth of GC in mice.

CONCLUSION

HRD1 mediates ubiquitination and degradation of ACSL4 to inhibit ferroptosis. MiR-221-3p depletion upregulates the ferroptosis in GC cells via upregulation of ATF3 to mediate the transcription inhibition of GPX4 and HRD1. Our study might provide a novel target for GC treatment.

The Pleiotropic role, functions and targeted therapies of LIF/LIFR axis in cancer: Old spectacles with new insights

The dysregulation of leukemia inhibitory factor (LIF) and its cognate receptor (LIFR) has been associated with multiple cancer initiation, progression, and metastasis. LIF plays a significant tumor-promoting role in cancer, while LIFR functions as a tumor promoter and suppressor. Epithelial and stromal cells secrete LIF via autocrine and paracrine signaling mechanism(s) that bind with LIFR and subsequently with co-receptor glycoprotein 130 (gp130) to activate JAK/STAT1/3, PI3K/AKT, mTORC1/p70s6K, Hippo/YAP, and MAPK signaling pathways. Clinically, activating the LIF/LIFR axis is associated with poor survival and anti-cancer therapy resistance. This review article provides an overview of the structure and ligands of LIFR, LIF/LIFR signaling in developmental biology, stem cells, cancer stem cells, genetics and epigenetics of LIFR, LIFR regulation by long non-coding RNAs and miRNAs, and LIF/LIFR signaling in cancers. Finally, neutralizing antibodies and small molecule inhibitors preferentially blocking LIF interaction with LIFR and antagonists against LIFR under pre-clinical and early-phase pre-clinical trials were discussed.