miR-1205/DNAJB1 reverses docetaxel chemoresistance in human triple negative breast carcinoma cells via regulation of mutp53/TAp63 signaling

CircBIRC6 affects prostate cancer progression by regulating miR-574-5p and DNAJB1

BACKGROUND

Prostate cancer (PCa) is among the three main types of cancer. Although prostate-specific antigen (PSA) is routinely tested, it has disadvantages, such as poor prognostic ability. Therefore, finding more PCa markers and therapeutic targets remains a subject of study. CircRNAs have been found to have regulatory roles in various diseases, such as diabetes, Central Nervous System (CNS) neuropathy, etc. where their application in cancer is even more valuable. Therefore, this paper aims to search for differentially expressed circRNAs in PCa and find downstream targeting pathways related to autophagy.

METHOD

By detecting the expression of circRNA in the samples, hsa_circ_0119816 was finally identified as the research target. The properties of circRNA were verified by RNase R, actinomycin D, and fluorescence in situ hybridization (FISH). The downstream target miRNAs and target proteins were predicted by an online database, and the targeting relationship was verified using dual luciferase and RNA Immunoprecipitation. The effects of circRNAs and their downstream signalling pathways on prostate cancer cell proliferation, migration, EMT and autophagy were examined by CCK-8, Transwell, immunofluorescence and Western blotting.

RESULTS

CircBIRC6 is highly expressed in prostate cancer samples. Knockdown of its expression inhibits cell proliferation, invasion, EMT and autophagy and promotes apoptosis. CircBIRC6/miRNA-574-5p/DNAJB1 is a molecular axis that regulates prostate cancer cells.

CircSLC4A7 in resistant-cells-derived exosomes promotes docetaxel resistance via the miR-1205/MAPT axis in prostate cancer

Prostate cancer (PCa) is a high-mortality cancer. Docetaxel (DCT) combined with second-generation anti-androgens is considered the golden standard therapy for PCa, whose application is limited for DCT resistance (DR). Therefore, exploring the mechanism of DR is of great importance. In this study, PCa cell lines of PC3 and DU145 were employed, and DR cells were constructed by treatment with graded DCT. CircSLC4A7, miR-1205, and microtubule-associated protein tau (MAPT) transfections were established. Cell counting kit-8 assay was performed to evaluate the cell activity and IC50 of DCT. After being treated with DCT, DR was assessed by colony formation assay, flow cytometry analysis, and terminal transferase-mediated UTP nick end-labeling assay. Real-time quantitative PCR and western blotting analysis evaluated the expression levels of genes. The dual-luciferase reporter gene assay verified the miR-1205 binding sites with circSLC4A7 and MAPT. An animal experiment was performed to assess the tumor growth influenced by circSLC4A7. After conducting DR cells and isolated exosomes, we found that not only co-culture with DR cells but also treatment with DR cells' exosomes would promote the DR of normal cells. Moreover, circSLC4A7 was highly expressed in DR cells and their exosomes. CircSLC4A7 overexpression enhanced DR, represented as raised IC50 of DCT, increased colony formation, and decreased cell apoptosis after DCT treatment, while circSLC4A7 knockdown had the opposite effect. MiR-1205 was confirmed as a circSLC4A7-sponged miRNA and miR-1205 inhibitor reversed the effect of sh-circSLC4A7. MAPT was further identified as a target of miR-1205 and had a similar effect with circSLC4A7. The effect of circSLC4A7 on DR was also confirmed by xenograft experiments. Collectively, circSLC4A7 in resistant-cells-derived exosomes promotes DCT resistance of PCa via miR-1205/MAPT axis, which may provide a new treatment strategy for DR of PCa.

MicroRNA-1205 promotes breast cancer cell metastasis by regulating epithelial-to-mesenchymal transition via targeting of CDK3

Metastasis poses a huge obstacle to the survival of breast cancer patients. The microRNA miR-1205 acts as a tumor suppressor in various cancers, but its roles in breast cancer and metastasis remain unclear. To elucidate its function in breast cancer progression, we analyzed miR-1205 expression in human tumor samples and carried out a series of functional studies in in vitro and in vivo. miR-1205 was expressed more highly in metastatic breast tumor samples than in non-metastatic samples and was associated with lymph node metastasis, clinical stage, and poor prognosis. Moreover, miR-1205 promoted breast cancer cell invasiveness in vitro and metastasis in mice by directly targeting CDK3 and reducing CDK3 protein levels. We also showed that CDK3 interacts with Snail protein, inducing Snail degradation via the ubiquitin-proteasome system and potentially affecting epithelial-to-mesenchymal transition. Furthermore, analysis of clinical tissue samples indicated that CDK3 and miR-1205 levels were inversely correlated in lymph node metastasis-positive primary tumors. This study demonstrated the pro-metastatic role of miR-1205 in breast cancer, mediated via a novel miR-1205/CDK3/Snail axis. Moreover, we identified miR-1205 and CDK3 as potential markers of invasion and progression in breast cancer.

FUNDC2, a mitochondrial outer membrane protein, mediates triple-negative breast cancer progression via the AKT/GSK3β/GLI1 pathway

Triple-negative breast cancer (TNBC) lacks effective therapeutic targets and has a poor prognosis, easy recurrence and metastasis. It is urgent and important to explore TNBC treatment targets. Through mass spectrometry combined with qRT-PCR validation in luminal A cells and TNBC cells, high-content screening and clinical sample analysis, FUNDC2 was discovered as a novel target. The function of the outer mitochondrial membrane protein FUNDC2 in breast cancer is still unclear. In this study, we find that FUNDC2 expression in TNBC tissues is significantly higher than that in luminal subtype breast cancer tissues. FUNDC2 silencing in TNBC cells significantly reduces cell proliferation, migration and invasion. As demonstrated in vivo using subcutaneous tumor xenografts in mice, FUNDC2 suppression significantly inhibits tumor growth. The underlying mechanism might be mediated by inactivating its downstream signal AKT/GSK3β and GLI1, a key factor of the Hedgehog signaling pathway. Therefore, FUNDC2 may promote TNBC progression and provide a therapeutic target for treating TNBC.

Hsa_circ_0137652 Regulates miR-1205/CCNB1 Axis to Accelerate the Malignancy of Breast Cancer

CircRNAs have become a hotspot in tumor research owing to their high stability and specific functions. We investigated the function of hsa_circ_0137652 in the onset and progression of breast cancer (BC). The expression of circ_0137652, miR-1205, and CCNB1 in BC tissues and cell lines were detected using RT-qPCR and/or western blotting. Dual-luciferase reporter and RNA immunoprecipitation chip assays were used to confirm any potential connections between circ_0137652, miR-1205, and CCNB1. CCK-8 and clone formation assays (CFA) were used to measure the proliferation of BC cells. The Transwell assay was used to investigate the migration of BC cells, and the impact of circ_0137652 on BC tumor formation in vivo was validated using animal experiments. RT-qPCR results showed that circ_0137652 and CCNB1 in breast cancer tissues were notably upregulated in normal tissues, whereas miR-1205 was prominently downregulated. After silencing circ_0137652, the growth and migration of BC cells were reduced. Animal experiments showed that circ_0137652 hampers the tumorigenesis of BC cells in vivo. Additionally, we found that circ_0137652 functions as a sponge for miR-1205. Moreover, the miR-1205 inhibitor notably facilitated cell proliferation and migration and attenuated the action of circ_0137652 knockdown. Furthermore, miR-1205 inhibits BC progression by targeting CCNB1. Circ_0137652 controls the miR-1205/CCNB1 axis to induce increased breast cancer malignancy. Our findings suggest that circ_0137652 may be a novel target for BC therapy.

Functional impact of non-coding RNAs in high-grade breast carcinoma: Moving from resistance to clinical applications: A comprehensive review

Despite the recent advances in cancer therapy, triple-negative breast cancers (TNBCs) are the most relapsing cancer sub-type. It is partly due to their propensity to develop resistance against the available therapies. An intricate network of regulatory molecules in cellular mechanisms leads to the development of resistance in tumors. Non-coding RNAs (ncRNAs) have gained widespread attention as critical regulators of cancer hallmarks. Existing research suggests that aberrant expression of ncRNAs modulates the oncogenic or tumor suppressive signaling. This can mitigate the responsiveness of efficacious anti-tumor interventions. This review presents a systematic overview of biogenesis and down streaming molecular mechanism of the subgroups of ncRNAs. Furthermore, it explains ncRNA-based strategies and challenges to target the chemo-, radio-, and immunoresistance in TNBCs from a clinical standpoint.

Erdafitinib Inhibits Tumorigenesis of Human Lung Adenocarcinoma A549 by Inducing S-Phase Cell-Cycle Arrest as a CDK2 Inhibitor

Lung adenocarcinoma (LADC) is the most prevalent lung cancer sub-type, and targeted therapy developed in recent years has made progress in its treatment. Erdafitinib, a potent and selective pan-FGFR tyrosine kinase inhibitor, has been confirmed to be effective for the treatment of LADC; however, the molecular mechanism responsible for this effect is unclear. The in vitro study showed that erdafitinib exhibited an outstanding anti-cancer activity in human LADC cell line A549 by inducing S-phase cell-cycle arrest and cell apoptosis. The mechanistic study based on the transcriptomic data revealed that erdafitinib exerted its anti-cancer effect by affecting the cell cycle-related pathway, and CDK2 was the regulatory target of this drug. In addition, CDK2 overexpression significantly attenuated the anti-cancer effect of erdafitinib by affecting the transcriptional activity and expression of E2F1, as well as the expression of CDK1. The in vivo study showed that erdafitinib presented an obvious anti-cancer effect in the A549 xenograft mice model, which was accompanied by the reduced expression of CDK2. Thus, this study demonstrates the anti-cancer effect of erdafitinib against LADC for the first time based on in vitro and in vivo models, whose activity is achieved by targeting CDK2 and regulating downstream E2F1-CDK1 signaling. This study may be helpful for expanding the clinical application of erdafitinib in treating LADC.