MiR-221-3p Facilitates Thyroid Cancer Cell Proliferation and Inhibit Apoptosis by Targeting FOXP2 Through Hedgehog Pathway

Tubular FoxP2 and Kidney Fibrosis

Key Points

FOXP2/Foxp2 is overexpressed in human and in murine unilateral ureteral obstruction and unilateral ischemia-reperfusion models. Foxp2 overexpression mediates epithelial-to-mesenchymal transition and G2/M cell cycle arrest in kidney tubular cells to promote fibrosis.

Background

Kidney fibrosis is the final common pathway of progressive CKD that leads to kidney failure, for which there are limited therapeutic strategies. The transcription factor, Forkhead box P2 (Foxp2 ), has been implicated in organ development and tumorigenesis through its association with the epithelial-to-mesenchymal transition (EMT) process. In this study, we uncovered a novel role of Foxp2 in kidney fibrosis.

Methods

Human kidney biopsies were used to assess FOXP2 expression. Tubule-specific Foxp2 knockout mice were generated through LoxP-Cre transgenic manipulation and applied to murine models of progressive CKD, including unilateral ureteral obstruction (UUO) and unilateral ischemia-reperfusion injury (UIRI). Cultured kidney tubular epithelial cells were used to analyze the underlying cellular mechanisms.

Results

FOXP2 expression was markedly increased in the tubular nuclei of human kidney biopsies of CKD from patients with IgA nephropathy, membranous nephropathy, and diabetic nephropathy. In murine UUO and UIRI models that recapitulate progressive CKD, tubule-specific deletion of Foxp2 attenuated kidney inflammation and tubulointerstitial fibrosis, accompanied by reduction in cell cycle arrest. In mouse tubular epithelial cells, TGF-β upregulated Foxp2 expression through Smad3 signaling while knockdown of Foxp2 suppressed TGF-β -induced EMT and accumulation of extracellular matrix proteins. Mechanistically, overexpression of Foxp2 inhibited tubular cell proliferation with induction of G2/M cell cycle arrest. Using chromatin-immunoprecipitation sequencing, we identified Foxp2 target genes that are enriched in phosphatidylinositol 3-kinase/protein kinase B and TGF-β signaling pathways and further revealed that Foxp2 directly regulated the transcriptional activities of collagen-1, E-cadherin, and p21 that are involved in EMT and cell cycle arrest, thereby promoting the profibrotic process.

Conclusions

Our findings demonstrate a novel role of Foxp2 in promoting kidney fibrosis in murine UUO and UIRI by activating EMT and cell cycle arrest in kidney tubules, contributing to the progression of CKD.

MiRNAs in Extracellular Vesicles as Biomarkers in Plasma of Papillary Thyroid Cancer Patients: A Proof-of-Concept Study

BACKGROUND

The incidence of various types of cancer, for example, papillary thyroid carcinoma (PTC), is on the rise. Since therapeutic success depends greatly on early diagnosis, reliable diagnostic biomarkers must be identified, and easy-to-apply tools for detecting them must urgently be standardized. Here, we contribute to solving this medical challenge by assessing miRNAs suspected of promoting carcinogenesis in extracellular vesicles (EVs) that can be routinely obtained via liquid biopsy. We profit from current progress in cancerology that provides innovations in liquid biopsy and EVs analysis, along with the identification of miRNAs and chaperone system (CS) components implicated in carcinogenesis.

METHODS

We measured in EVs obtained from circulating blood plasma from PTC patients the levels of three miRNAs implicated in thyroid cancer, hsa-miR-1-3p, hsa-miR-206, and hsa-miR-221-3p, and most likely involved in the regulation of two members of the CS, Hsp60 and CCT. EVs were isolated from the plasma of patients with PTC and controls with benign goiter (BG) and from the culture medium of a PTC cell line (MDAT32) and were appropriately characterized.

RESULTS

The levels of miRNAs determined by RT-qPCR were consistently higher in PTC patients and decreased down to control levels after thyroidectomy. Bioinformatics showed that the miRNAs target genes are associated with the molecular pathogenesis of PTC.

CONCLUSIONS

Our exploratory study reaffirms the potential in clinics of the selected miRNAs in EVs as useful biomarkers of PTC easily accessible via liquid biopsy, which is minimally invasive and amenable to periodic repetition, an improvement compared to the established fine-needle aspirate biopsy.

GAS5, a long noncoding RNA, contributes to annulus fibroblast osteogenic differentiation and apoptosis in intervertebral disk degeneration via the miR-221-3p/SOX11 axis

miR-221-3p has been reported to attenuate the osteogenic differentiation of annulus fibrosus cells (AFs), which has been implicated in intervertebral disk degeneration (IVDD) development. This study aimed to elucidate miR-221-3p's role in osteogenic differentiation and apoptosis of AFs in an IVDD model. After successfully establishing an IVDD rat model by annulus fibrosus needle puncture, AFs were isolated. Bioinformatics, dual-luciferase reporter, and AGO2-RNA immunoprecipitation (RIP) assays predicted and confirmed the potential miR-221-3p lncRNA and gene target. Functional analyses were performed after AF transfection to explore the roles of the identified lncRNA and gene. Western blotting, Alkaline phosphatase (ALP), and Alizarin red and TUNEL staining were performed to investigate AF apoptosis and osteogenic differentiation with different transfections. Compared with AFs isolated from sham rats, IVDD-isolated Afs exhibited stronger osteogenic potential and higher apoptosis rates accompanied by miR-221-3p downregulation. The growth arrest-specific transcript 5 (GAS5) was identified as miR-221-3p's target lncRNA, which was highly expressed in IVDD. GAS5 overexpression facilitated AF apoptosis and osteogenic differentiation, whereas silencing GAS5 had the opposite effect. SRY box-related11 (SOX11) was identified as a downstream miR-221-3p target gene in IVDD. GASS silencing-induced suppression of AF apoptosis and osteogenic differentiation could be reversed by SOX11 overexpression. Our findings uncovered a lncRNA GAS5/miR-221-3p/SOX11 axis in Afs under IVDD, which may help implement novel IVDD therapeutic strategies.

Reduced expression of miR-221 is associated with the pro-apoptotic pathways in spermatozoa of oligospermia men

Oligospermia and asthenozoospermia, both frequent, can lead to male infertility. Oligospermia might be viewed as a milder form of azoospermia because the same mutations that produce azoospermia in some individuals also create oligospermia in other individuals. In this, we looked at different characteristics of oligospermia men, counting the level of apoptosis and a few related apoptotic and oxidative stress components, and compared them to solid controls. In this study, semen samples from healthy fertile men (n = 35) and oligospermia (n = 35) were collected, and sperm death rates in both groups were examined using flow cytometry. Also, gene expression of apoptotic and anti-apoptotic markers and miR-221 were investigated (Real-Time PCR). Moreover, for the evaluation of catalase and SOD activity and anti-inflammatory cytokines, including IL-10 and TGF-β, the specific ELISA kits and procedures were applied. As a result, higher gene and protein expression levels of PTEN, P27, and P57 were observed in patients with oligospermia. In contrast, lower mRNA expression of AKT and miR-221 was detected in this group. In addition, IL-10, TGF-β, and catalase activity were suppressed in the oligospermia group compared with healthy men samples. Moreover, the frequency of apoptosis of sperm cells is induced in patients. In conclusion, apoptosis-related markers, PTEN, and the measurement of significant and efficient oxidative stress markers like SOD and catalase in semen plasma could be considered as the critical diagnostic markers for oligospermia. Future studies will be better able to treat oligospermia by showing whether these indicators are rising or falling.

Hypoxic papillary thyroid carcinoma cells-secreted exosomes deliver miR-221-3p to normoxic tumor cells to elicit a pro-tumoral effect by regulating the ZFAND5

Papillary thyroid cancer (PTC) has seen a worldwide expansion in incidence in the past three decades. Tumor-derived exosomes have been associated with the metastasis of cancer cells and are present within the local hypoxic tumor microenvironment, where they mediate intercellular communication by transferring molecules including microRNAs (miRNAs) between cells. Although miRNAs have been shown to serve as non-invasive biomarkers for cancer diagnosis, the role of hypoxia-induced tumor-derived exosomes in PTC progression remains unclear. Herein, we investigated the differentially expressed miRNA expression profiles from GEO datasets (GSE191117 and GSE151180) by using the DESeq package in R and identified a novel role for miR-221-3p as an oncogene in PTC development. In vivo and in vitro loss and gain assays were used to clarify the mechanism of hypoxic PTC cells derived exosomal-miR-221-3p in PTC. miR-221-3p was upregulated in human PTC plasma exosomes, tissues and cell lines. We found that hypoxic PTC cells derived exosomal-miR-221-3p promoted normoxic PTC cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) in vitro, while inhibition of miR-221-3p limited PTC tumor growth in our PTC xenograft model in nude mice. We finally identified ZFAND5, to be a miR-221-3p target. Mechanistically, hypoxic PTC cell lines-derived exosomes carrying miR-221-3p promoted PTC tumorigenesis by regulating ZFAND5. Our findings further the understanding of the underlying mechanisms associated with PTC progression and identify exosomal-miR-221-3p as a potential biomarker for the diagnosis and prognosis of PTC patients. Our study also suggests that miR-221-3p inhibitors could be a potential treatment strategy for PTC.

Profilin1 Promotes Renal Tubular Epithelial Cell Apoptosis in Diabetic Nephropathy Through the Hedgehog Signaling Pathway

Background

Profilin-1 (PFN1) regulates the dynamic balance of actin and plays an important role in cell functions as a hub protein in signaling molecule interaction networks. Dysregulation of PFN1 is related to pathologic kidney diseases. Diabetic nephropathy (DN) was recently reported as an inflammatory disorder, however, the molecular mechanisms of PFN1 in DN remain unclear. Therefore, the present study was conducted to explore the molecular and bioinformatic characteristics of PFN1 in DN.

Methods

Bioinformatics analyses were performed on the chip of database in DN kidney tissues. A cellular model of DN was established in human renal tubular epithelial cells (HK-2) induced by high glucose. The PFN1 gene was overexpressed or knocked-down to investigate its function in DN. Flow cytometry was used to detect cell proliferation and apoptosis. PFN1 and proteins in the related signaling pathways were evaluated by Western blotting.

Results

The expression of PFN1 was significantly increased in DN kidney tissues (P < 0.001) and was correlated with a high apoptosis-associated score (Pearson's correlation = 0.664) and cellular senescence-associated score (Pearson's correlation = 0.703). PFN1 protein was mainly located in cytoplasm. Overexpression of PFN1 promoted apoptosis and blocked the proliferation of HK-2 cells treated with high levels of glucose. Knockdown of PFN1 led to the opposite effects. Additionally, we found that PFN1 was correlated with the inactivation of the Hedgehog signaling pathway in HK-2 cells treated with high levels of glucose.

Conclusion

PFN1 might play an integral role in the regulation of cell proliferation and apoptosis during DN development by activating the Hedgehog signaling pathway. This study provided molecular and bioinformatic characterizations of PFN1, and contributed to the understanding of the molecular mechanisms leading to DN.

Expression level and function analysis of serum miRNAs in workers with occupational exposure to benzene series

Benzene series are ubiquitous in industrial production and daily life, and can have an impact on health even at low concentrations. miRNAs have been proved to be a biomarker of a variety of diseases and carcinogens. The purpose of this study was to explore the distribution characteristics and biological function of miRNAs in subjects exposed to benzene series. In this study, serum miRNAs were measured in 247 occupationally exposed subjects and 256 controls. The relationship between cumulative exposure dose of benzene series and miRNAs was analyzed by Generalized linear model, Spearman's rank correlation, and chi-square test for trend. The function of MiRNAs target gene was analyzed by means of bioinformatics method. The results showed that the expressions of miR-181a-5p, 221-3p, 223-3p, and 342-3p were down-regulated, whilst the expression of miR-638 was up-regulated in the occupational exposure group. miR-181a-5p, 221-3p, 223-3p, 342-3p, and 638 showed dose-response relationship with benzene series, and were closely related to multiple tumor pathways. miR-181a-5p, 221-3p, 223-3p, 342-3p, and 638 may be involved in the carcinogenic process of benzene series, and can be used to evaluate the early biological effects and monitor the exposure level of benzene series. miRNAs are potential biomarkers of benzene series exposure.

Silencing FOXP2 reverses vemurafenib resistance in BRAFV600E mutant papillary thyroid cancer and melanoma cells

BACKGROUND

Vemurafenib (VEM) is a commonly used inhibitor of papillary thyroid cancer (PTC) and melanoma with the BRAFV600E mutation; however, acquired resistance is unavoidable. The present study aimed to identify a potential target to reverse resistance.

MATERIALS AND METHODS

A VEM-resistant PTC cell line (B-CPAP/VR) was established by gradually increasing the drug concentration, and a VEM-resistant BRAFV600E melanoma cell line (A375/VR) was also established. RNA sequencing and bioinformatics analyses were conducted to identify dysregulated genes and construct a transcription factor (TF) network. The role of a potential TF, forkhead box P2 (FOXP2), verified by qRT-PCR, was selected for further confirmation.

RESULTS

The two resistant cell lines were tolerant of VEM and displayed higher migration and colony formation abilities (p < 0.05). RNA sequencing identified 9177 dysregulated genes in the resistant cell lines, and a TF network consisting of 13 TFs and 44 target genes was constructed. Alterations in FOXP2 expression were determined to be consistent between the two VEM-resistant cell lines. Finally, silencing FOXP2 resulted in an increase in drug sensitivity and significant suppression of the migration and colony formation abilities of the two resistant cell lines (p < 0.05).

CONCLUSIONS

The present study successfully established two VEM-resistant cell lines and identified a potential target for VEM-resistant PTC or melanoma.

Identification of Exosomal microRNAs and Their Targets in Papillary Thyroid Cancer Cells

The release of molecules in exosomal cargoes is involved in tumor development and progression. We compared the profiles of exosomal microRNAs released by two thyroid cancer cell lines (TPC-1 and K1) with that of non-tumorigenic thyroid cells (Nthy-ori-3-1), and we explored the network of miRNA–target interaction. After extraction and characterization of exosomes, expression levels of microRNAs were investigated using custom TaqMan Advanced array cards, and compared with those expressed in the total cell extracts. The functional enrichment and network-based analysis of the miRNAs’ targets was also performed. Five microRNAs (miR-21-5p, miR-31-5p, miR-221-3p, miR-222-3p, and let-7i-3p) were significantly deregulated in the exosomes of tumor cells vs. non-tumorigenic cells, and three of them (miR-31-5p, miR-222-3p, and let-7i-3p) in the more aggressive K1 compared to TPC-1 cells. The network analysis of the five miRNAs identified some genes as targets of more than one miRNAs. These findings permitted the identification of exosomal microRNAs secreted by aggressive PTC cells, and indicated that their main targets are regulators of the tumor microenvironment. A deeper analysis of the functional role of the targets of exosomal miRNAs will provide further information on novel targets of molecular treatments for these neoplasms.