This study aims to elucidate the role of circUSP9X (Circular RNA Ubiquitin Specific Peptidase 9 X-Linked) in the development of venous thrombosis in the lower extremities.
An animal model of Deep Vein Thrombosis (DVT) and a hypoxic model of Human Umbilical Vein Endothelial Cells (HUVECs) treated with Cobalt (II) Chloride (CoCl2) were developed. The expression levels of circUSP9X, microRNA-148b-3p (miR-148b-3p), and SRC Kinase Signaling Inhibitor 1 (SRCIN1) were quantified using quantitative reverse transcription Polymerase Chain Reaction and Western blot analysis. Cell cytotoxicity, viability, apoptosis, and inflammation in HUVECs were assessed via Lactate Dehydrogenase (LDH) assay, MTT assay, flow cytometry, Enzyme-Linked Immunosorbent Assay, and Western blot, respectively. Hematoxylin and Eosin staining were employed for histopathological examination of the venous tissues in the animal model. The interaction between circUSP9X, miR-148b-3p, and SRCIN1 was further explored through dual-luciferase reporter assays and RNA Immunoprecipitation experiments.
The present findings reveal a significant upregulation of circUSP9X and SRCIN1 and a concurrent downregulation of miR-148b-3p in DVT cases. Knockdown of circUSP9X or overexpression of miR-148b-3p ameliorated CoCl2-induced apoptosis in HUVECs, reduced LDH release, enhanced cellular viability, and mitigated inflammation. Conversely, overexpression of circUSP9X intensified CoCl2\'s cytotoxic effects. The effects of manipulating circUSP9X expression were counteracted by the corresponding modulation of miR-148b-3p and SRCIN1 levels. Additionally, circUSP9X knockdown effectively inhibited the formation of DVT in the mouse model. A competitive binding mechanism of circUSP9X for miR-148b-3p, modulating SRCIN1 expression, was identified.
circUSP9X promotes the formation of DVT through the regulation of the miR-148b-3p/SRCIN1 axis.

Breast cancer is a leading cause of cancer mortality in women worldwide. Using the Infinium MethylationEPIC BeadChip, we analyzed plasma sample methylation to identify the SRCIN1 gene in breast cancer patients. We assessed SRCIN1-related roles and pathways for their biomarker potential. To verify the methylation status, quantitative methylation-specific PCR (qMSP) was performed on genomic DNA and circulating cell-free DNA samples, and mRNA expression analysis was performed using RT‒qPCR. The results were validated in a Western population; for this analysis, the samples included plasma samples from breast cancer patients from the USA and from The Cancer Genome Atlas (TCGA) cohort. To study the SRCIN1 pathway, we conducted cell viability assays, gene manipulation and RNA sequencing. SRCIN1 hypermethylation was identified in 61.8% of breast cancer tissues from Taiwanese patients, exhibiting specificity to this malignancy. Furthermore, its presence correlated significantly with unfavorable 5-year overall survival outcomes. The levels of methylated SRCIN1 in the blood of patients from Taiwan and the USA correlated with the stage of breast cancer. The proportion of patients with high methylation levels increased from 0% in healthy individuals to 63.6% in Stage 0, 80% in Stage I and 82.6% in Stage II, with a sensitivity of 78.5%, an accuracy of 90.3% and a specificity of 100%. SRCIN1 hypermethylation was significantly correlated with increased SRCIN1 mRNA expression (p < 0.001). Knockdown of SRCIN1 decreased the viability of breast cancer cells. SRCIN1 silencing resulted in the downregulation of ESR1, BCL2 and various cyclin protein expressions. SRCIN1 hypermethylation in the blood may serve as a noninvasive biomarker, facilitating early detection and prognosis evaluation, and SRCIN1-targeted therapies could be used in combination regimens for breast cancer patients.

The tricho-rhino-phalangeal syndrome-1 gene (Trps1) is an atypical GATA family member. Although current studies of Trps1 mainly focus on tumors, whether Trps1 plays a role in the male reproductive system remains unknown.
The purpose of this study was to elucidate the function of Trps1 in Leydig cells, indicating its regulatory mechanism on the cell cycle.
Gene-silencing technology, RNA-seq, RT-qPCR, and western blotting were used to evaluate the function of Trps1 in mouse primary Leydig cells and MLTC-1 cells. In addition, ChIP-base sets and ChIP-qPCR were employed to further assess the regulatory mechanism of Trps1 in MLTC-1 cells.
Knockdown of Trps1 in Leydig cells significantly suppressed phosphorylation of Src and Akt and expression of Ccnd1, which was accompanied by impairment of cell proliferative ability. Trps1 may affect the cell cycle through the Src/Akt/Ccnd1 signaling pathway. In addition, Trps1 may bind to the promoter of Srcin1 to regulate its transcription, thus influencing Src phosphorylation levels and the proliferation of Leydig cells.
Src increases in Leydig cells during pubertal development, suggesting its functional involvement in differentiated adult Leydig cells. Inhibition of the Src/Akt pathway would reduce Ccnd1 expression. In the present study, we found that Trps1 may regulate the phosphorylation level of Src and Akt through Srcin1, targeting Ccnd1 to influence mouse Leydig cell proliferation. These findings shed light on the regulation of Trps1 on cell proliferation and differentiation of mouse Leydig cells.

The p140Cap adaptor protein is a scaffold molecule encoded by the SRCIN1 gene, which is physiologically expressed in several epithelial tissues and in the neurons. However, p140Cap is also strongly expressed in a significant subset of cancers including breast cancer and neuroblastoma. Notably, cancer patients with high p140Cap expression in their primary tumors have a lower probability of developing a distant event and ERBB2-positive breast cancer sufferers show better survival. In neuroblastoma patients, SRCIN1 mRNA levels represent an independent risk factor, which is inversely correlated to disease aggressiveness. Consistent with clinical data, SRCIN1 gain or loss of function mouse models demonstrated that p140Cap may affect tumor growth and metastasis formation by controlling the signaling pathways involved in tumorigenesis and metastatic features. This study reviews data showing the relevance of SRCIN1/p140Cap in cancer patients, the impact of SRCIN1 status on p140Cap expression, the specific mechanisms through which p140Cap can limit cancer progression, the molecular functions regulated by p140Cap, along with the p140Cap interactome, to unveil its key role for patient stratification in clinics.

BACKGROUND: Long non-coding RNA (lncNRA) forkhead box D3 antisense RNA 1 (FOXD3-AS1) has been proved to promote or suppress the occurrence and development of multiple types of human tumors. However, the function and mechanism of FOXD3-AS1 in non-small cell lung cancer (NSCLC) are scarcely understood.
METHODS: qRT-PCR was used for detecting FOXD3-AS1, miR-150 and SRC kinase signaling inhibitor 1 (SRCIN1) mRNA expression in NSCLC tissues, and the relationship between pathological characteristics of NSCLC patients and FOXD3-AS1 expression level was analyzed. With human NSCLC cell lines H1299 and A549 as cell models, CCK-8 and BrdU assays were employed for detecting cancer cell proliferation, and Transwell assay was employed for detecting cell invasion ability. Dual luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay were used for the verification of the targeting relationshipe between FOXD3-AS1 and miR-150, and Western blot was employed for detecting SRCIN1 protein expression.
RESULTS: FOXD3-AS1 expression was significantly reduced in NSCLC tissues and cell lines, and low expression of FOXD3-AS1 was closely related to positive lymph node metastasis and relatively high tumor grade. FOXD3-AS1 over-expression inhibited the proliferation and invasion of H1299 cell lines, while its knockdown promoted the proliferation and invasion of A549 cells. Additionally, it was confirmed that FOXD3-AS1 suppressed the expression of miR-150 by targeting it, and up-regulated the expression of SRCIN1.
CONCLUSIONS: FOXD3-AS1 indirectly enhances the expression of SRCIN1 by targeting miR-150, thereby inhibiting NSCLC progression.

Background: Lung cancer is the most common malignant tumor worldwide. Accumulating results have shown that long non-coding RNAs (lncRNAs) play a key role in tumorigenesis. Patients and Methods: A total of 163 tumor tissues were collected from non-small cell lung cancer (NSCLC) patients from West China Hospital of Sichuan University. LincRNA00494 is a novel lncRNA, and its expression and biological effect in NSCLC were reported in this study. NSCLC cell lines were used in this study. Results: LincRNA00494 is mainly distributed in the cytoplasm. LincRNA00494 was downregulated in the tumor tissues compared with the adjacent non-tumor tissues. LincRNA00494 expression was positively correlated with SRCIN1 expression (R = 0.57, P < 0.05). Silencing of LincRNA00494 in the cell lines substantially decreased SRCIN1 expression at the mRNA and protein levels, whereas overexpression of LincRNA00494 enhanced the SRCIN1 levels. miR-150-3p significantly decreased the luciferase signals of LincRNA00494 and SRCIN1 reporters. After transfection with miR-150-3p mimics and miR-150-3p inhibitor, overexpression of LincRNA00494 decreased the proliferation of the H358 (36%) and H1299 (29%) cell lines compared with that of the control cells, as shown by CCK-8 assays, whereas silencing LincRNA00494 promoted the proliferation of the H358 (47%) and H1299 (35%) cells. Tumor growth from LincRNA00494-overexpressing xenografts was significantly decreased; additionally, LincRNA00494 silencing substantially increased tumor growth compared with that of the control cells. Conclusions: Functional experiments revealed that LincRNA00494 inhibited NSCLC cell proliferation, which might be related to the suppression of SRCIN1, a tumor suppressor gene, by acting as a decoy for miR-150-3p. The data showed that LincRNA00494 might have antineoplastic effects during NSCLC tumorigenesis through its role as a ceRNA.

The p140Cap adaptor protein is a scaffold molecule physiologically expressed in few epithelial tissues, such as the mammary gland, and in differentiated neurons. While the role of p140Cap in mammary gland epithelia is not still understood, we already know that a significant subset of breast cancers express p140Cap. In the subgroup of ERBB2-amplified breast cancers, a high p140Cap status predicts a significantly lower probability of developing a distant event and a clear difference in survival. p140Cap is causal in dampening ERBB2-positive tumor cell progression, impairing tumor onset and growth, and counteracting epithelial mesenchymal transition, resulting in decreased metastasis formation. Since only a few p140Cap interacting proteins have been identified in breast cancer and the molecular complexes and pathways underlying the cancer function of p140Cap are largely unknown, we generated a p140Cap interactome from ERBB2-positive breast cancer cells, identifying cancer specific components and those shared with the synaptic interactome. We identified 373 interacting proteins in cancer cells, including those with functions relevant to cell adhesion, protein homeostasis, regulation of cell cycle and apoptosis, which are frequently deregulated in cancer. Within the interactome, we identified 15 communities (clusters) with topology-functional relationships. In neurons, where p140Cap is key in regulating synaptogenesis, synaptic transmission and synaptic plasticity, it establishes an extensive interactome with proteins that cluster to sub complexes located in the postsynaptic density. p140Cap interactors converge on key synaptic processes, including synaptic transmission, actin cytoskeleton remodeling and cell-cell junction organization. Comparing the breast cancer to the synaptic interactome, we found 39 overlapping proteins, a relatively small overlap. However, cell adhesion and remodeling of actin cytoskeleton clearly emerge as common terms in the shared subset. Thus, the functional signature of the two interactomes is primarily determined by organ/tissue and functional specificity, while the overlap provides a list of shared functional terms, which might be linked to both cancer and neurological functions.

UNASSIGNED: Previous studies have shown that miR-373 functions as either a tumor suppressor or an oncogene depending on which type of cancer it\'s operating in. However, the functional role of miR-373 in neuroblastoma (NB) remains largely unclear.
UNASSIGNED: Expression of miR-373 and SRC kinase signaling inhibitor 1 (SRCIN1) in 20 metastatic and 20 primary NB tissues was detected by quantitative real-time PCR (qRT-PCR) and Western blotting. MTT assay, flow cytometry analysis and transwell migration and invasion assays were performed to evaluate the influence of miR-373 inhibition on the growth, migration and invasion of NB cells, respectively. In vivo experiment was applied to determine the effect of miR-373 inhibition on tumor growth. Dual-luciferase reporter assay was used to confirm the interaction between miR-373 and SRCIN1.
UNASSIGNED: We observed a significant increase in the expression of miR-373 in metastatic NB samples compared with primary NB samples, and this was inversely correlated with SRCIN1 expression. Functional studies revealed that depletion of miR-373 inhibited in vitro NB cell growth, migration and invasion, and also suppressed tumor growth in an in vivo mouse model. Moreover, we identified that SRCIN1 was a direct and functional target gene of miR-373. Silencing of SRCIN1 partially rescued the antimiR-373-mediated inhibition of cell growth, migration and invasion.
UNASSIGNED: The data from our study verified a potential oncogenic role of miR-373 in NB cells that occurs through direct targeting SRCIN1. The newly identified miR-373/SRCIN1 axis represents a new potential candidate for therapeutic intervention of malignant NB.

Bone metastasis of breast cancer makes patients suffer from pain, fractures, spinal cord compression, and hypercalcemia, and is almost incurable. Although the mechanisms of bone metastasis in breast cancers have been studied intensively, novel specific target will be helpful to the development of new therapeutic strategy of breast cancer. Herein, we focused on the microRNA of tumor cell-derived exosomes to investigate the communication between the bone microenvironment and tumor cells. The expression of miR-20a-5p in the primary murine bone marrow macrophages (BMMs), MCF-10A, MCF-7, and MDA-MB-231 cell lines, as well as the cell-derived exosomes were assessed by qRT-PCR. Transwell assays were used to evaluate the effects of miR-20a-5p on tumor cell migration and invasion. The expression of exosomes marker including CD63and TSG101 was detected by Western Blot. Cell cycle distribution of BMMs was analyzed by flow cytometry. 3-UTR luciferase reporter assays were used to validate the putative binding between miR-20a-5p and SRCIN1. MiR-20a-5p was highly expressed in breast tumor tissues and the exosomes of MDA-MB-231 cells. MiR-20a-5p promoted migration and invasion in MDA-MB-231 cells, and the proliferation and differentiation of osteoclasts. MDA-MB-231 cell-derived exosomes transferred miR-20a-5p to BMMs and facilitated the osteoclastogenesis via targeting SRCIN1. The present work provides evidence that miR-20a-5p transferred from breast cancer cell-derived exosomes promotes the proliferation and differentiation of osteoclasts by targeting SRCIN1, providing scientific foundations for the development of exosome or miR-20a-5p targeted therapeutic intervention in breast cancer progression.

Addictive behaviors, including relapse, are thought to depend in part on long-lasting drug-induced adaptations in dendritic spine signaling and morphology in the nucleus accumbens (NAc). While the influence of activity-dependent actin remodeling in these phenomena has been studied extensively, the role of microtubules and associated proteins remains poorly understood. We report that pharmacological inhibition of microtubule polymerization in the NAc inhibited locomotor sensitization to cocaine and contextual reward learning. We then investigated the roles of microtubule end-binding protein 3 (EB3) and SRC kinase in the neuronal and behavioral responses to volitionally administered cocaine. In synaptoneurosomal fractions from the NAc of self-administering male rats, the phosphorylation of SRC at an activating site was induced after 1 d of withdrawal, while EB3 levels were increased only after 30 d of withdrawal. Blocking SRC phosphorylation during early withdrawal by virally overexpressing SRCIN1, a negative regulator of SRC activity known to interact with EB3, abolished the incubation of cocaine craving in both male and female rats. Conversely, mimicking the EB3 increase observed after prolonged withdrawal increased the motivation to consume cocaine in male rats. In mice, the overexpression of either EB3 or SRCIN1 increased dendritic spine density and altered the spine morphology of NAc medium spiny neurons. Finally, a cocaine challenge after prolonged withdrawal recapitulated most of the synaptic protein expression profiles observed at early withdrawal. These findings suggest that microtubule-associated signaling proteins such as EB3 cooperate with actin remodeling pathways, notably SRC kinase activity, to establish and maintain long-lasting cellular and behavioral alterations following cocaine self-administration.SIGNIFICANCE STATEMENT Drug-induced morphological restructuring of dendritic spines of nucleus accumbens neurons is thought to be one of the cellular substrates of long-lasting drug-associated memories. The molecular basis of these persistent changes has remained incompletely understood. Here we implicate for the first time microtubule function in this process, together with key players such as microtubule-bound protein EB3 and synaptic SRC phosphorylation. We propose that microtubule and actin remodeling cooperate during withdrawal to maintain the plastic structural changes initially established by cocaine self-administration. This work opens new translational avenues for further characterization of microtubule-associated regulatory molecules as putative drug targets to tackle relapse to drug taking.