Elucidating the Role of Let-7d-5p and OLR1 in the Progression and Prognosis of Oral Squamous Cell Carcinoma via FAK/P53 Signaling Axis.

BACKGROUND/AIM: Despite advances in oral squamous cell carcinoma (OSCC) diagnosis and treatment, the five-year survival rate remains low, underscoring the need for improved biomarkers and therapeutic strategies. This study investigated the role of let-7d-5p microRNA (miRNA) and its target gene OLR1 in OSCC, focusing on their implications in tumor progression, metastasis and potential as therapeutic targets. MATERIALS AND METHODS: Employing next-generation sequencing and bioinformatic tools, we profiled differentially expressed miRNAs in metastatic OSCC cell lines, identifying let-7d-5p as a key down-regulated miRNA and OLR1 as a novel target of let-7d-5p. We validated this interaction using luciferase reporter assays and studied the biological effects of modulating let-7d-5p and OLR1 expression on OSCC cell proliferation, migration, invasion, and stemness. Additionally, we analyzed clinical data to establish the relevance of OLR1 expression in OSCC prognosis. RESULTS: Our findings revealed let-7d-5p as a potent suppressor of OSCC metastasis, primarily by targeting and down-regulating OLR1. OLR1-silencing reduced OSCC cell invasiveness, migration, and stemness, indicating its prominent role in tumor progression. Mechanistically, let-7d-5p modulates a signaling cascade involving FAK, SRC, PAXILLIN, and p53, influencing cellular apoptosis and chemoresistance. Clinically, elevated OLR1 expression significantly correlates with advanced OSCC stages and poorer survival rates, highlighting its potential as a prognostic marker and therapeutic target. CONCLUSION: Our study uncovers the significance of the let-7d-5p-OLR1 axis in OSCC pathogenesis, offering novel insights for future therapeutic interventions.

High glucose promotes atherosclerosis by regulating miRNA let7d-5p level.

BACKGROUND: MiRNA let7d-5p has been recently reported to be abnormally expressed in diabetes-associated atherosclerosis (AS). However, it still remains unknown how let7d-5p contributes to the process of atherosclerosis. METHODS: Twenty fresh tissues and a total of 28 wax block specimens from carotid endarterectomy procedures were obtained from the Luoyang Central Hospital affiliated to Zhengzhou University. The expression of let7d-5p was assessed using quantitative RT-PCR (qRT-PCR). A series of in vitro experiments was used to determine the roles of let7d-5p knockdown and overexpression in vascular smooth muscle cells (VSMCs). RESULTS: We discovered that the carotid plaques from diabetic patients had lower expression levels of miR let7d-5p. In VSMCs, the expression of miRNA let7d-5p was significantly lower in high glucose conditions compared with low glucose situations. The proliferation and migration of VSMCs were also inhibited by the overexpression of let7d-5p, whereas the opposite was true when let7d-5p was inhibited, according to gain and loss of function studies. Mechanically, let7d-5p might activate the GSK3ß/ß-catenin signaling pathway via binding to the high mobility group AT-Hook 2 (HMGA2) mRNA in VSMCs. Additionally, GLP-1RA liraglutide may prevent the migration and proliferation of VSMCs by raising let7d-5p levels. CONCLUSIONS: High glucose stimulated the proliferation and migration of VSMCs by regulating the let7d-5p/HMGA2/GSK3ß/ß-catenin pathway, and liraglutide may slow atherosclerosis by increasing the levels of miR let7d-5p.

E2F5 Targeted by Let-7d-5p Facilitates Cell Proliferation, Metastasis and Immune Escape in Gallbladder Cancer.

BACKGROUND: Gallbladder cancer (GBC) remains a serious cause of cancer-related mortality across the globe. E2F5 has been identified to as a known oncogene in various cancers. However, the special functions of E2F5 have not been investigated in GBC. AIMS: To explore the regulatory functions of E2F5 and its related molecular regulatory mechanism in GBC progression. METHODS: The expression of genes were examined through qRT-PCR, western blot and IHC assay. The cell proliferation was assessed through CCK-8 and EDU assays. The cytotoxicity was tested through LDH assay. The percentage of CD8+ T cells and cell apoptosis were evaluated through flow cytometry. The binding ability was detected through luciferase reporter assay. The tumor growth was assessed through in vivo assays. RESULTS: In this study, it was demonstrated that E2F5 expression was evaluated in GBC, and resulted into poor prognosis. Bioinformatics analysis revealed E2F5 as a target for let-7d-5p, which when overexpressed, suppressed the metastasis and proliferation of GBC through the downregulation of E2F5. It was discovered that E2F5 activates JAK2/STAT3 signaling which is suppressed by let-7d-5p, implicating this pathway as one of the effectors of the oncogenic effects of ESF5 in GBC. E2F5 had been confirmed to aggravate tumor growth in vivo. CONCLUSION: E2F5 targeted by let-7d-5p facilitated cell proliferation, metastasis and immune escape in GBC through the JAK2/STAT3 pathway.

Low let-7d microRNA levels in chick embryos enhance innate immunity against Mycoplasma gallisepticum by suppressing the mitogen-activated protein kinase pathway.

Chick embryos are a valuable model for studying immunity and vaccines. Therefore, it is crucial to investigate the molecular mechanism of the Mycoplasma gallisepticum (MG)-induced immune response in chick embryos for the prevention and control of MG. In this study, we screened for downregulated let-7d microRNA in MG-infected chicken embryonic lungs to explore its involvement in the innate immune mechanism against MG. Here, we demonstrated that low levels of let-7d are a protective mechanism for chicken embryo primary type II pneumocytes (CP-II) in the presence of MG. Specifically, we found that depressed levels of let-7 in CP-II cells reduced the adhesion capacity of MG. This suppressive effect was achieved through the activated mitogen-activated protein kinase phosphatase 1 (MKP1) target gene and the inactivated mitogen-activated protein kinase (MAPK) pathway. Furthermore, MG-induced hyperinflammation and cell death were both alleviated by downregulation of let-7d. In conclusion, chick embryos protect themselves against MG infection through the innate immune molecule let-7d, which may result from its function as an inhibitor of the MAPK pathway to effectively mitigate MG adhesion, the inflammatory response and cell apoptosis. This study may provide new insight into the development of vaccines against MG.

Maternal expression of miR-let-7d-3p and miR-451a during gestation influences the neuropsychomotor development of 90 days old babies: "Pregnancy care, healthy baby" study.

INTRODUCTION: Studies on maternal microRNA expression have emerged to better understand regulatory mechanisms during the gestational period, since microRNA expression has been associated with pregnancy disorders. OBJECTIVES: This study aims to investigate the association between the expression of the maternal microRNAs miR-let-7d-3p and miR-451a during the second gestational trimester and neuropsychomotor development at 90 days of life of infants. METHODS: This is a case-control study nested within a cohort, with the groups being divided into dyads in which pregnant women presented Major Depressive Episode (MDE) (n = 64), these being the cases, and their respective controls (no MDE; n = 64). The Bayley Scale III was used to assess the outcome of child development, and MDE was assessed through the Mini International Neuropsychiatric Interview Plus. The analysis of miR-let-7d-3p and miR-451a was done via serum from the pregnant women, utilizing the qRT-PCR (n = 128). RESULTS: The results indicated a negative association between expression levels of miR-451a (ß -3.3 CI95% -6.4;-0.3) and a positive associated of the miR-let-7d-3p with the cognitive development domain (ß 1.7 CI95% 0.1; 3.0), and a positive association between expression of miR-let-7d-3p with motor development of the infants (ß 1.6 CI95% 0.3; 2.9). CONCLUSION: This is a pioneering study on the topic that indicates a biological interrelationship between the miRNAs miR-let-7d-3p and miR-451a evaluated during the pregnancy and the motor and cognitive domains of infant development at 90 days postpartum.

Evidence for the circulating microRNA hsa-let-7d-3p as a potential new biomarker for sepsis in human subjects.

BACKGROUND: Current biomarkers for the early detection of sepsis have low sensitivity and specificity. Serum microRNAs (miRNAs) have been proposed as novel noninvasive biomarkers for various diseases. The aim of the present study was to discover a novel diagnostic biomarker for sepsis in human subjects. METHODS: miRNA expression profiling was performed using peripheral blood from three sepsis patients in the sepsis stage and improved condition stage using microarray screening. The differentially expressed miRNAs were primary validated by real-time quantitative polymerase chain reaction (RT-qPCR) in a further set of 20 sepsis patients in the sepsis stage and improved condition stage. Finally, we validated the differentially expressed miRNAs in 95 sepsis patients and 66 nonsepsis patients. The validated miRNAs and patients' clinical indictors were analysed in a multivariate logistic regression model. The diagnostic value of the changed miRNA in sepsis was determined and compared with CRP and WBC by analysing the receiver operating characteristic (ROC) curves. RESULTS: According to the criteria, we detected 11 miRNAs regulated by the miRNA chip. RT-qPCR detection showed that the expression of hsa-let-7d-3p in sepsis patients was upregulated compared with that in nonsepsis patients. In a multiple logistic regression analysis, serum miRNA hsa-let-7d-3p was found to be an independent predictor of sepsis. Receiver operating characteristic curve (ROC) analysis showed that the area under the ROC curve of serum hsa-let-7d-3p was 0.696 [95% confidence interval (0.615, 0.778)]. CONCLUSION: The miRNA hsa-let-7d-3p was identified as a novel biomarker for the early detection of sepsis.

Urinary Exosomal MicroRNAs as New Noninvasive Biomarkers of IgA Nephropathy.

Immunoglobulin A nephropathy (IgAN) is the most common type of primary glomerulonephritis. It is very important to find new noninvasive biomarkers for the diagnosis and treatment of IgAN. The purpose of this study was to explore the clinical value of urinary exosomal miRNAs in IgAN. In this study, urinary exosomes were isolated from 29 IgAN patients and 29 healthy controls. The miRNA was analyzed by high-throughput sequencing. The expression of hsa-miR-451a and hsa-let-7d-3p was examined by real-time quantitative polymerase chain reaction (RT-qPCR). The diagnostic value of miRNAs was evaluated using receiver operating characteristic (ROC) curves. Here, hsa-miR-451a and hsa-let-7d-3p were upregulated in IgAN patients compared with healthy controls. We evaluated the diagnostic value of hsa-miR-451a and hsa-let-7d-3p using ROC curves; hsa-miR-451a (AUC = 0.805, p = 0.001), hsa-mir-7d-3p (AUC = 0.76, p = 0.0049), and the combination of hsa-miR-451a and hsa-let-7d-3p (AUC = 0.8125, p = 0.0007). Hsa-miR-451a has correlations with Lee's grades (r = 0.511, p = 0.021), and 24-h urinary protein excretion (UPE; r = 0.557, p = 0.011). Hsa-let-7d-3p showed correlations with Lee's grades (r = 0.6, p = 0.005), UPE (r = 0.518, p = 0.019), serum creatinine (r = 0.564, p = 0.01), and estimated glomerular filtration rate (r = -0.532, p = 0.016). According to the Oxford classification, for hsa-miR-451a, S0 had lower levels than S1 (p = 0.016); for hsa-mir-7d-3p, M0 had lower levels than M1 (p = 0.05). These findings suggest that hsa-miR-451a and hsa-let-7d-3p may serve as noninvasive biomarkers for the evaluation of IgAN.

Diagnostic Potential of Plasma Extracellular Vesicle miR-483-3p and Let-7d-3p for Sepsis.

Background: microRNAs (miRNAs) from circulating extracellular vesicles (EVs) have been reported as disease biomarkers. This study aimed to identify the diagnostic value of plasma EV-miRNAs in sepsis. Methods: EVs were separated from the plasma of sepsis patients at admission and healthy controls. The expression of EV-miRNAs was evaluated by microarray and qRT-PCR. Results: A preliminary miRNA microarray of plasma EVs from a discovery cohort of 3 sepsis patients at admission and three healthy controls identified 11 miRNAs with over 2-fold upregulation in sepsis group. Based on this finding, EV samples from a validation cohort of 37 sepsis patients at admission and 25 healthy controls were evaluated for the expression of the 6 miRNAs relating injury and inflammation via qRT-PCR. Elevated expression of miR-483-3p and let-7d-3p was validated in sepsis patients and corroborated in a mouse model of sepsis. miR-483-3p and let-7d-3p levels positively correlated with the disease severity. Additionally, a combination of miR-483-3p and let-7d-3p had diagnostic value for sepsis. Furthermore, bioinformatic analysis and experimental validation showed that miR-483-3p and let-7d-3p target pathways regulating immune response and endothelial function. Conclusion: The present study reveals the potential role of plasma EV-miRNAs in the pathogenesis of sepsis and the utility of combining miR-483-3p and let-7d-3p as biomarkers for early sepsis diagnosis.

Trametes robiniophila represses angiogenesis and tumor growth of lung cancer via strengthening let-7d-5p and targeting NAP1L1.

Trametes robiniophila (Huaier) is available to refrain lung cancer (LC) cell progression, but its impact and mechanism on angiogenesis of LC are not proved. The study was to explore the potential mechanism of Huaier repressing angiogenesis and tumor growth in LC via strengthening let-7d-5p and targeting NAP1L1. Let-7d-5p and NAP1L1 expression was detected in LC tissues and cells (A549). Pretreatment of A549 cells was with Huaier. Transfection of changed let-7d-5p and NAP1L1 was to A549 cells to uncover their roles in LC cell progression with angiogenesis. Evaluation of the impact of let-7d-5p on angiogenesis in LC was in vitro in a mouse xenograft model. Identification of the targeting of let-7d-5p with NAP1L1 was clarified. The results clarified reduced let-7d-5p but elevated NAP1L1 were manifested in LC. Huaier restrained angiogenesis and tumor growth of LC in vivo and in vitro; Augmented let-7d-5p or declined NAP1L1 motivated the therapy of Huaier on LC; Let-7d-5p negatively modulated NAP1L1; Elevated NAP1L1 reversed the influence of enhancive let-7d-5p. These results strongly suggest that Huaier represses angiogenesis and tumor growth in LC via strengthening let-7d-5p and targeting NAP1L1. Huaier/let-7d-5p/NAP1L1 axis is supposed to be a promising target for the treatment of angiogenesis and tumor growth in LC via elevated let-7d-5p and targeted NAP1L1.

MiR-let-7d-3p inhibits granulosa cell proliferation by targeting TLR4 in polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a typical reproductive and endocrinological disorder of women at child-bearing age. In this study, we used miRNA sequencing technology and verified miR-let-7d-3p as a vital miRNA in PCOS. RT-qPCR confirmed miR-let-7d-3p was significantly increased in granulosa cells (GCs) of PCOS. Cell counting kit-8 (CCK-8) identified the suppression of miR-let-7d-3p mimic in KGN cell proliferation and PI3K/Akt signaling pathway. Dual luciferase reporter assay proved that Toll-like receptor 4 (TLR4) was a target of miR-let-7d-3p, and TLR4 was significantly down-regulated by miR-let-7d-3p. Furthermore, over-expression of TLR4 promoted KGN cell proliferation and rescued the inhibition of miR-let-7d-3p on KGN cells. In conclusion, miR-let-7d-3p was a crucial miRNA up-regulated in GCs of PCOS, and inhibited cell proliferation by targeting TLR4 gene.

Layered Double Hydroxide Nanoparticles with Osteogenic Effects as miRNA Carriers to Synergistically Promote Osteogenesis of MSCs.

Inefficient differentiation and poor engraftment hinder the clinical applications of mesenchymal stem cell (MSC)-based cell therapies in regenerative medicine. Layered double hydroxide (LDH) nanoparticles are sheet-like materials with desirable biocompatibility and anion-exchange properties and have been widely applied as drug and nucleotide carriers in the field of tissue repair. However, few studies have focused on the biological effects of LDH itself. In this study, we demonstrated the novel function of LDH in stimulating osteogenic differentiation of bone marrow-derived MSCs (BMSCs). The expression of osteogenic-related genes, alkaline phosphatase (ALP) activity, and calcium deposits were significantly increased after LDH treatment. Mechanistic analysis performed with RNA sequencing revealed that LDH promoted osteogenesis by targeting the LGR5/ß-catenin axis. LDH also inactivated IKK/NF-κB signaling under LPS-triggered inflamed conditions, suggesting the dual benefits of LDH in enhancing bone regeneration and alleviating the inflammatory response. Furthermore, we utilized LDH as the transport vehicle of the osteoinductive miRNA let-7d to synergistically regulate BMSCs toward the osteoblastic lineage. The LDH/let-7d complex resulted in a better induction of osteogenesis than LDH alone. For cell transplantation, BMSCs were seeded in LDH/let-7d-incorporated fibrin scaffolds, which proved enhanced osteoinduction capability in the subcutaneous ectopic osteogenesis model in nude mice. Taken together, this study provides a novel strategy for effective and synergistic improvement of osteogenesis via LDH-mediated delivery of miRNA let-7d, thus shedding light on the future application of LDH in regenerative medicine.

Overexpression of let-7d explains down-regulated KDM3A and ENO2 in the pathogenesis of preeclampsia.

Pre-eclampsia (PE) is the leading cause of maternal death; however, the causative molecular basis remains largely unknown. Recent studies have revealed the important role microRNAs (miRNAs) play in PE. We aimed to explore the effects of let-7d on trophoblast proliferation, migration, invasion and apoptosis in PE and its underlying mechanism. Placental tissues were collected from PE patients and healthy pregnant women, and it was found that let-7d expression was increased, while KDM3A and ENO2 expression was decreased in PE tissues and cells. Bioinformatics analysis indicated the interaction among let-7d, KDM3A and ENO2, confirmed by dual luciferase reporter gene assay; ChIP experiment identified methylated modification to ENO2 by KDM3A. With gain- and loss-function method, silencing of let-7d increased KDM3A expression and enhanced the binding between KDM3A and ENO2. Furthermore, overexpression of let-7d suppressed cell proliferation, migration and invasion of trophoblasts, and induced apoptosis of trophoblasts, while these capacities were restored upon additional treatment of overexpressed ENO2. PE rat models were established to explore the effects of let-7d and ENO2 on PE in vivo. The results established that the silencing of let-7d alleviated the tissue injury and PE-related symptoms when reducing urine protein, TUNEL-positive cells and increasing ENO2, and KDM3A expression in rats. Cumulatively, let-7d suppressed cell progression of trophoblasts, and induced apoptosis through the down-regulation of KDM3A to promote ENO2 methylation, thereby promoting progression of PE. Such an epigenetic network of let-7d, KDM3A and ENO2 in the pathogenesis of PE might provide novel insight into targeted therapy against this disorder.

Induction of microRNA hsa-let-7d-5p, and repression of HMGA2, contribute protection against lipid accumulation in macrophage 'foam' cells.

Accumulation of excess cholesterol and cholesteryl ester in macrophage 'foam' cells within the arterial intima characterises early 'fatty streak' atherosclerotic lesions, and is accompanied by epigenetic changes, including altered expression of microRNA sequences which determine of gene and protein expression. This study established that exposure to lipoproteins, including acetylated LDL, induced macrophage expression of microRNA hsa-let-7d-5p, a sequence previously linked with tumour suppression, and repressed expression of one of its target genes, high mobility group AT hook 2 (HMGA2). A let-7d-5p mimic repressed expression of HMGA2 (18%; p < 0.05) while a marked increase (2.9-fold; p < 0.05) in expression of HMGA2 was noted in the presence of let-7d-5p inhibitor. Under these conditions, let-7d-5p mimic significantly (p < 0.05) decreased total (10%), free (8%) and cholesteryl ester (21%) mass, while the inhibitor significantly (p < 0.05) increased total (29%) and free cholesterol (29%) mass, compared with the relevant controls. Let-7d-5p inhibition significantly (p < 0.05) increased endogenous biosynthesis of cholesterol (38%) and cholesteryl ester (39%) pools in macrophage 'foam' cells, without altering the cholesterol efflux pathway, or esterification of exogenous radiolabelled oleate. Let-7d-5p inhibition in sterol-loaded cells increased the level of HMGA2 protein (32%; p < 0.05), while SiRNA knockdown of this protein (29%; p < 0.05) resulted in a (21%, p < 0.05) reduction in free cholesterol mass. Thus, induction of let-7d-5p, and repression of its target HMGA2, in macrophages is a protective response to the challenge of increased cholesterol influx into these cells; dysregulation of this response may contribute to atherosclerosis and other disorders such as cancer.

Lung Cancer Cell-Derived Exosomal let-7d-5p Down-Regulates OPRM1 to Promote Cancer-Induced Bone Pain.

Cancer-induced bone pain (CIBP) is the pain caused by metastasis of malignant tumors to the bone, accounting for more than half of all chronic cancer pain, which seriously affects the quality of life among tumor patients. Up to 40% of patients with advanced lung cancer suffer from CIBP. MicroRNA (miRNA) transfers between cells through exosomes, mediates cell-to-cell communication, and performs various biological functions. Studies have shown that miRNAs secreted by cancer can modify the tumor microenvironment, but whether exosome-mediated miRNA transfer plays a role in CIBP is still unknown. In this study, the expression levels of 15 miRNAs in exosomes derived A549 cells and 18 miRNAs in exosomes derived NCI-H1299 cells were significantly up-regulated, and qRT-PCR further confirmed that the level of let-7d-5p was increased most considerably. In vitro, exosomal let-7d-5p (EXO let-7d-5p) can be taken up by dorsal root ganglion (DRG) neurons and inhibit the protein level of the target gene opioid receptor mu 1 (OPRM1). EXO let-7d-5p was further confirmed to be involved in the generation and maintenance of CIBP in vivo. Our findings clarify the molecular mechanism of CIBP caused by the inhibition of OPRM1 by EXO let-7d-5p, providing new clues and intervention targets for the prevention and treatment of CIBP.

circBANP promotes colorectal cancer growth and metastasis via sponging let-7d-5p to modulate HMGA1/Wnt/ß-catenin signaling.

Colorectal cancer (CRC) is one of the most common and deadly cancers, and the incidence of CRC is on the rise. Due to the lack of early diagnosis method and high metastasis of the disease, the prognosis of CRC remains very poor. Exploring the underlying molecular mechanisms of CRC is very necessary for effective therapy. In this study, we investigated the function of circBANP in CRC. The results showed that circBANP was elevated in both CRC tissues and cells and its level positively correlated with the stage of CRC. Knockdown of circBANP greatly suppressed the epithelial-mesenchymal transition (EMT) process and CRC cell proliferation, migration, and invasion. In addition, knockdown of circBANP inhibited CRC tumor growth and metastasis in vivo. Further, circBANP directly bound to let-7d-5p and regulated CRC development via acting as a let-7d-5p sponge. Let-7d-5p directly targeted HMGA1 and thus circBANP/let-7d-5p regulated Wnt/ß-catenin signaling via HMGA1. Collectively, circBANP promotes CRC development and metastasis via acting as a let-7d-5p sponge to regulate HMGA1/Wnt/ß-catenin signaling, providing a potential biomarker and therapeutic target for the management of CRC.

Let-7d and miR-185 Impede Epithelial-Mesenchymal Transition by Downregulating Rab25 in Breast Cancer.

OBJECTIVE: MicroRNAs (miRNAs) expression has deregulated in several cancer types including breast cancer (BC). The present study aims at investigating the role, mechanism, clinical value of let-7d and miR-185 in BC, and the possible correlation these miRNAs with Rab25. MATERIALS AND METHODS: Tumor samples as well adjacent normal tissues (ANT) were acquired from fresh surgical specimens from 110 patients and the expression levels of let-7d, miR-185, Rab25, and snail were evaluated using real-time PCR. The immunohistochemical (IHC) process and western blot were done to detect the level of Rab25 and Snail protein expression in BC samples. RESULTS: By comparing miRNAs expression profiles in clinical tissues of 110 patients using real-time PCR, let-7d, and miR-185 expression were dramatically downregulated in BC tissues (P < 0.05). Tumor size, stage, and lymph node metastasis were significantly related to miRNAs expression. Based on qRT-PCR and bioinformatics database analyses, we also recognized Rab25 as a possible target of miR-185 and let-7d. Rab25 expression was enhanced in BC cells and associated inversely with the expression level of mentioned miRNAs. qRT-PCR, immunohistochemistry, and western blot studies verified that Rab25 upregulation increased the levels of the snail, that key transcription factor of epithelial-mesenchymal transition (EMT). CONCLUSION: These findings demonstrated that let-7d and miR-185 inhibited EMT by targeting Rab25 expression in BC. Therefore, targeting the let-7d and miR-185/Rab25 interaction may offer new therapeutic opportunities for treating BC patients.
.

HMGA2-induced epithelial-mesenchymal transition is reversed by let-7d in intrauterine adhesions.

Intrauterine adhesions (IUAs), the leading cause of uterine infertility, are characterized by endometrial fibrosis. The management of IUA is challenging because the pathogenesis of the disease largely unknown. In this study, we demonstrate that the mRNA and protein levels of high mobility group AT-hook 2 (HMGA2) were increased by nearly 3-fold (P < 0.0001) and 5-fold (P = 0.0095) in the endometrial epithelial cells (EECs) of IUA patients (n = 18) compared to controls. In vivo and in vitro models of endometrial fibrosis also confirmed the overexpression of HMGA2 in EECs. In vitro cell experiments indicated that overexpression of HMGA2 promoted the epithelial-mesenchymal transition (EMT) while knockdown of HMGA2 reversed transforming growth factor-ß-induced EMT. A dual luciferase assay confirmed let-7d microRNA downregulated HMGA2 and repressed the pro-EMT effect of HMGA2 in vitro and in vivo. Therefore, our data reveal that HMGA2 promotes IUA formation and suggest that let-7d can depress HMGA2 and may be a clinical targeting strategy in IUA.

Let-7d inhibits intratumoral macrophage M2 polarization and subsequent tumor angiogenesis by targeting IL-13 and IL-10.

The microRNA let-7d has been reported to be a tumor suppressor in renal cell carcinoma (RCC). Tumor-associated macrophages (TAM) are M2-polarized macrophages that can enhance tumor growth and angiogenesis in many human cancers. However, the role of let-7d in TAM-associated RCC progression remains elusive. First, we observed a strongly inverse correlation between let-7d expression and microvessel density in RCC tissues. Furthermore, the proliferation, migration, and tube formation of HUVECs were significantly inhibited by conditioned medium from a coculture system of the phorbol myristate acetate pretreated human THP-1 macrophages and let-7d-overexpressing RCC cells. Moreover, the proportion of M2 macrophages was significantly lower in the group that was cocultured with let-7d-overexpressing RCC cells. Subcutaneous xenografts formed by the injection of let-7d-overexpressing RCC cells together with THP-1 cells resulted in a significant decrease in the M2 macrophage ratio and microvessel density compared with those formed by the injection of control RCC cells with THP-1 cells. In silico and experimental analysis revealed interleukin-10 (IL-10) and IL-13 as let-7d target genes. Importantly, the addition of IL-10 and IL-13 counteracted the inhibitory effects of the conditioned medium from the coculture system with let-7d-overexpressing RCC cells in vitro. Additionally, overexpression of IL-10 and IL-13 reversed the effects of let-7d on macrophage M2 polarization and tumor angiogenesis in vivo. Finally, the expression of IL-10 and IL-13 were inversely correlated with the expression of let-7d in RCC clinical specimens. These results suggest that let-7d may inhibit intratumoral macrophage M2 polarization and subsequent tumor angiogenesis by targeting IL-10 and IL-13.

Long non-coding RNA DIO3OS/let-7d/NF-κB2 axis regulates cells proliferation and metastasis of thyroid cancer cells.

Due to the steadily rising morbidity and mortality, thyroid cancer remains the most commonly seen endocrine cancer. The present study attempted to investigate the mechanism from the perspective of long non-coding RNA (lncRNA) regulation. We identified 53 markedly increased lncRNAs in thyroid cancer samples according to TCGA data. Among them, high lncRNA DIO3OS expression was a risk factor for thyroid cancer patients' poorer overall survival. DIO3OS showed to be considerably increased within thyroid cancer tissue samples and cells. Knocking down DIO3OS within thyroid carcinoma cells suppressed cancer cell viability, the capacity of DNA synthesis, cell invasion, as well as cell migration; besides, proliferating markers, ki-67 and PCNA, were decreased by DIO3OS knockdown. Cancer bioinformatics analysis suggested that NF-κB2 might be related to DIO3OS function in thyroid cancer carcinogenesis. NF-κB2 was positively correlated with DIO3OS, and DIO3OS knockdown decreased NF-κB2 protein levels. Knocking down NF-κB2 within thyroid carcinoma cells suppressed cancer cell viability, the capacity of DNA synthesis, cell invasion, cell migration, and the protein levels of proliferating markers. Let-7d directly targeted DIO3OS and NF-κB2; DIO3OS knockdown upregulated let-7d expression. The overexpression of let-7d suppressed cancer cell viability, the capacity of DNA synthesis, cell invasion, cell migration, as well as the protein levels of proliferating markers. Let-7d inhibition remarkably attenuated the functions of DIO3OS knockdown in NF-κB2 expression and thyroid cancer cell phenotype. In conclusion, DIO3OS/let-7d/NF-κB2 axis regulates the viability, DNA synthesis capacity, invasion, and migration of thyroid cancer cells. The clinical application of this axis needs further in vivo and clinical investigation.

Low let-7d exosomes from pulmonary vascular endothelial cells drive lung pericyte fibrosis through the TGFßRI/FoxM1/Smad/ß-catenin pathway.

The pathogenesis of pulmonary fibrosis (PF) was mediated by the progressive deposition of excessive extracellular matrix, but little is known about the regulatory mechanisms of fibrogenesis by lung pericytes. The mouse PF model was established by treatment with bleomycin, followed by isolation of exosomes from mouse broncho-alveolar lavage fluids by the centrifuge method. Relative mRNA/microRNA levels and protein expression were assessed by qRT-PCR and Western blotting, respectively. The binding of let-7d with gene promoter was validated by dual-luciferase reporter assay. Protein interactions were verified via GST pull-down and co-immunoprecipitation. Nuclear retention of Smad3 was analysed by extraction of cytoplasmic and nuclear fraction of pericytes followed by Western blotting. Association of FoxM1 with gene promoter was detected by EMSA and ChIP-PCR methods. FoxM1 expression is significantly elevated in human lung fibroblasts of PF patients and mouse PF model. The expression of let-7d is repressed in exosomes derived from broncho-alveolar lavage fluids of PF mice. Let-7d or FoxM1 knockdown suppressed the expression of FoxM1, Smad3, ß-catenin, Col1A and α-SMA expression in mouse lung pericytes under TGF-ß1 treatment. FoxM1 overexpression elevated above gene expression in mouse lung pericytes under TGF-ß1 treatment. Let-7d directly targets TGFßRI to regulate FoxM1 and downstream gene expression in mouse lung pericytes. FoxM1 directly interacts with Smad3 proteins to promote Smad3 nuclear retention and binds with ß-catenin promoter sequence to promote fibrogenesis. Exosomes with low let-7d from pulmonary vascular endothelial cells drive lung pericyte fibrosis through activating the TGFßRI/FoxM1/Smad/ß-catenin signalling pathway.