CBLL1 promotes endometrial stromal cell senescence via inhibiting PTEN in recurrent spontaneous abortion.

Recurrent spontaneous abortion (RSA) is a common pregnancy-related disorder. Cbl proto-oncogene like 1 (CBLL1) is an E3 ubiquitin ligase, which has been reported to vary with the menstrual cycle in the endometrium. However, whether CBLL1 is involved in the occurrence and development of RSA remains unclear. This study aimed to investigate the effects of CBLL1 on RSA. We analyzed the expression of CBLL1 in the decidua of RSA patients, as well as its functional effects on cellular senescence, oxidative stress, and proliferation of human endometrial stromal cells (HESCs). RNA sequencing was employed to identify a key downstream target gene regulated by CBLL1. We found that CBLL1 was upregulated in the decidua of RSA patients. Additionally, overexpression of CBLL1 promoted HESC senescence, increased oxidative stress levels, and inhibited proliferation. Phosphatase and tensin homolog located on chromosome 10 (PTEN) was identified as one of the important downstream target genes of CBLL1. In vivo experiments demonstrated that CBLL1 overexpression in the endometrium caused higher embryo absorption rate in mice. Consequently, elevated CBLL1 expression is a potential cause of RSA, representing a novel therapeutic target for RSA.

Circ_0072083 interference enhances growth-inhibiting effects of cisplatin in non-small-cell lung cancer cells via miR-545-3p/CBLL1 axis.

BACKGROUND: Non-small-cell lung cancer (NSCLC) is one of the common cancers in the world. Circular RNA 0072083 (circ_0072083, circZFR) has been reported to be associated with the progression of NSCLC. In this study, we intended to explore the role and the potential mechanism of circ_0072083 in NSCLC. METHODS: Quantitative real time polymerase chain reaction (qRT-PCR) was performed to detect the expression of circ_0072083, its matching linear RNA (zinc finger RNA binding protein (ZFR)) and microRNA-545-3p (miR-545-3p) in NSCLC cells. The ability of colony formation in NSCLC cells was detected by colony formation assay. The apoptosis and cell cycle were measured by flow cytometry. The metastasis was determined by transwell migration and invasion assays. The protein expression of E-cadherin, N-cadherin, Vimentin and Cbl proto-oncogene like 1 (CBLL1) was examined by western blot assay. The interaction between miR-545-3p and circ_0072083 or CBLL1 was predicted by starBase or Targetscan software. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were applied to validate these interactions. Nude mice bearing tumors were used to confirm the role of circ_0072083 and cisplatin (DDP) in vivo. RESULTS: The level of circ_0072083 was higher in NSCLC tissues and cells relative to that in adjacent non-tumor tissues and normal lung cells. The transfection of si-circ_0072083 inhibited colony formation, cell cycle and metastasis while promoted the apoptosis of NSCLC cells stimulated by DDP. MiR-545-3p was a direct functional target of circ_0072083 in NSCLC cells. CBLL1 could bind to miR-545-3p in NSCLC cells. Circ_0072083 promoted the progression of NSCLC induced by DDP through sponging miR-545-3p and enhancing the enrichment of CBLL1 in vivo and in vitro. CONCLUSION: Circ_0072083 depletion contributed to DDP-triggered inhibition of NSCLC tumor through miR-545-3p/CBLL1 axis.

Clinical and molecular significance of the RNA m6A methyltransferase complex in prostate cancer.

N6-methyladenosine (m6A) is the most abundant internal mRNA modification and is dynamically regulated through distinct protein complexes that methylate, demethylate, and/or interpret the m6A modification. These proteins, and the m6A modification, are involved in the regulation of gene expression, RNA stability, splicing and translation. Given its role in these crucial processes, m6A has been implicated in many diseases, including in cancer development and progression. Prostate cancer (PCa) is the most commonly diagnosed non-cutaneous cancer in men and recent studies support a role for m6A in PCa. Despite this, the literature currently lacks an integrated analysis of the expression of key components of the m6A RNA methyltransferase complex, both in PCa patients and in well-established cell line models. For this reason, this study used immunohistochemistry and functional studies to investigate the mechanistic and clinical significance of the METTL3, METTL14, WTAP and CBLL1 components of the m6A methyltransferase complex in PCa specimens and cell lines. Expression of METTL3 and CBLL1, but not METTL14 and WTAP, was associated with poorer PCa patient outcomes. Expression of METTL3, METTL14, WTAP and CBLL1 was higher in PCa cells compared with non-malignant prostate cells, with the highest expression seen in castrate-sensitive, androgen-responsive PCa cells. Moreover, in PCa cell lines, expression of METTL3 and WTAP was found to be androgen-regulated. To investigate the mechanistic role(s) of the m6A methyltransferase complex in PCa cells, short hairpin RNA (shRNA)-mediated knockdown coupled with next generation sequencing was used to determine the transcriptome-wide roles of METTL3, the catalytic subunit of the m6A methyltransferase complex. Functional depletion of METTL3 resulted in upregulation of the androgen receptor (AR), together with 134 AR-regulated genes. METTL3 knockdown also resulted in altered splicing, and enrichment of cell cycle, DNA repair and metabolic pathways. Collectively, this study identified the functional and clinical significance of four essential m6A complex components in PCa patient specimens and cell lines for the first time. Further studies are now warranted to determine the potential therapeutic relevance of METTL3 inhibitors in development to treat leukaemia to benefit patients with PCa.

Expression and clinical prognostic value of m6A RNA methylation modification in breast cancer.

BACKGROUND: N6-methyladenosine(m6A) methylation modification affects the tumorigenesis, progression, and metastasis of breast cancer (BC). However, the expression characteristics and prognostic value of m6A modification in BC are still unclear. We aimed to evaluate the relationship between m6A modification and clinicopathological characteristics, and to explore the underlying mechanisms. METHODS: Three public cohorts and our clinical cohort were included: 1091 BC samples and 113 normal samples from the TCGA database, 1985 BC samples from the METABRIC database, 1764 BC samples from the KM Plotter website, and 134 BC samples of our clinical cohort. We collected date from these cohorts and analyzed the genetic expression, gene-gene interactions, gene mutations, copy number variations (CNVs), and clinicopathological and prognostic features of 28 m6A RNA regulators in BC. RESULTS: This study demonstrated that some m6A regulators were significantly differenially expressed in BCs and their adjacent tissues, and also different in various molecular types. All 28 studied m6A regulators exhibited interactions. KIAA1429 had the highest mutation frequency. CNVs of m6A regulators were observed in BC patients. The expression of the m6A regulators was differentially associated with survival of BC. Higher CBLL1 expression was associated with a better prognosis in BC than lower CBLL1 expression. Functional analysis showed that CBLL1 was related to the ESR1-related pathway, apoptosis-related pathway, cell cycle pathway and immune-related pathway in BC. CONCLUSIONS: m6A RNA modification modulated gene expression and thereby affected clinicopathological features and survival outcomes in BC. CBLL1 may be a promising prognostic biomarker for BC patients.

CBLL1 is highly expressed in non-small cell lung cancer and promotes cell proliferation and invasion.

BACKGROUND: Studies have shown that E3 ubiquitin ligase CBLL1 plays multiple roles in development and tumorigenesis. CBLL1 is over-expressed in colon cancer and associated with cancer cell proliferation. While, the overexpression of CBLL1 inhibited the estrogenic dependent cell proliferation and migration in ER alpha dependent breast cancer cell MCF-7. METHODS: We used an immunohistochemical method to detect CBLL1 expression in human NSCLC and corresponding normal lung tissues and analyzed its relationship with clinicopathological parameters. Moreover, we investigated the role of CBLL1 in NSCLC cell behavior by inhibiting its expression in A549 and H1299 cells. RESULTS: In this study, we found that CBLL1 was frequently upregulated in non-small lung cancer (NSCLC) tissues compared to the adjacent nontumor tissues. We found that the high expression of CBLL1 was associated with the tumor size in NSCLC tissues. It has been recently reported that CBLL1 promotes cell proliferation and invasion in A549 and H460 cells. Our results confirmed that CBLL1 promoted the proliferation by promoting G1/S cell cycle transition in NSCLCs cells. Moreover, CBLL1 knockdown inhibited cell invasion via increased E-cadherin protein expression, and decreased expression of MMP2 and MMP9 in NSCLC cell lines. The protein expression of E-cadherin was increased after CBLL1 depletion while the E-cadherin mRNA was not affected after knockdown of the endogenous CBLL1. CONCLUSION: These results provide important insights for using CBLL1 as an oncogenic marker gene in the development and progression of non-small cell lung cancer.

Human mesenchymal stem cell homing induced by SKOV3 cells.

Human mesenchymal stem cell (hMSC) homing is the migration of endogenous and exogenous hMSCS to the target organs and the subsequent colonization under the action chemotaxic factors. This is an important process involved in the repair of damaged tissues. However, we know little about the mechanism of hMSC homing. Stromal cell derived factor-1 (SDF-1) is a cytokine secreted by stromal cells. Its only receptor CXCR4 is widely expressed in blood cells, immune cells and cells in the central nervous system. SDF-1/CXCR4 signaling pathway plays an important role in hMSC homing and tissue repair. Human cbll1 gene encodes E3 ubiquitin-protein ligase Hakai (also known as CBLL1) consisting of RING-finger domain that is involved in ubiquitination, endocytosis and degradation of epithelial cadherin (E-cadherin) as well as in the regulation of cell proliferation. We successfully constructed LV3-CXCR4 siRNA lentiviral vector, LV3-CBLL1 RNAi lentiviral vector and the corresponding cell systems which were used to induce hMSC homing in the presence of SKOV3 cells. Thus the mechanism of hMSC homing was studied.