Jinmei Luo

Microrna-124 targets flotillin-1 to regulate proliferation and migration in breast cancer

BackgroundMicroRNAs (miRNAs) have been documented as playing important roles in cancer development. In this study, we investigated the role of miR-124 in breast cancer and clarified the regulation of flotillin-1 (FLOT1) by miR-124.MethodsThe expression levels of miR-124 were examined in breast cancer cell lines and patient specimens using quantitative reverse transcription-PCR. The clinicopathological significance of the resultant data was later analyzed. Next, we explored the function of miR-124 to determine its potential roles on cancer cell growth and migration in vitro. A luciferase reporter assay was conducted to confirm the target gene of miR-124, and the results were validated in cell lines and patient specimens.ResultsWe found that miR-124 expression was significantly downregulated in breast cancer cell lines and patient specimen compared with normal cell lines and paired adjacent normal tissues (P < 0.0001), respectively. MiR-124 was also associated with tumor node metastasis (TNM) stage (P = 0.0007) and lymph node metastasis (P = 0.0004). In breast cancer cell lines, the ectopic expression of miR-124 inhibited cell growth and migration in vitro. Moreover, we identified the FLOT1 gene as a novel direct target of miR-124, and miR-124 ectopic expression significantly inhibited FLOT1. Luciferase assays confirmed that miR-124 could directly bind to the 3′ untranslated region of FLOT1 and suppress translation. Moreover, FLOT1 was widely upregulated, and inversely correlated with miR-124 in breast cancer tissues. Consistent with the effect of miR-124, the knockdown of FLOT1 significantly inhibited breast cancer cell growth and migration. We also observed that the rescue expression of FLOT1 partially restored the effects of miR-124.ConclusionsOur study demonstrated that miR-124 might be a tumor suppressor in breast cancer via the regulation of FLOT1. This microRNA could serve as a potential diagnostic marker and therapeutic target for breast cancer.

Targeted expression of miR-34a using the T-VISA system suppresses breast cancer cell growth and invasion

Recurrence and metastasis result in a poor prognosis for breast cancer patients. Recent studies have demonstrated that microRNAs (miRNAs) play vital roles in the development and metastasis of breast cancer. In this study, we investigated the therapeutic potential of miR-34a in breast cancer. We found that miR-34a is downregulated in breast cancer cell lines and tissues, compared with normal cell lines and the adjacent nontumor tissues, respectively. To explore the therapeutic potential of miR-34a, we designed a targeted miR-34a expression plasmid (T-VISA-miR-34a) using the T-VISA system, and evaluated its antitumor effects, efficacy, mechanism of action, and systemic toxicity. T-VISA-miR-34a induced robust, persistent expression of miR-34a, and dramatically suppressed breast cancer cell growth, migration, and invasion in vitro by downregulating the protein expression levels of the miR-34a target genes E2F3, CD44, and SIRT1. In an orthotopic mouse model of breast cancer, intravenous injection of T-VISA-miR-34a:liposomal complex nanoparticles significantly inhibited tumor growth, prolonged survival, and did not induce systemic toxicity. In conclusion, T-VISA-miR-34a lead to robust, specific overexpression of miR-34a in breast cancer cells and induced potent antitumor effects in vitro and in vivo. T-VISA-miR-34a may provide a potentially useful, specific, and safe-targeted therapeutic approach for breast cancer.

Inhibitory effects of simvastatin on staphylococcus aureus lipoteichoic acid-induced inflammation in human alveolar macrophages

Staphylococcus aureus(S. aureus) is the most common bacterium in sepsis and pneumonia involving gram-positive bacteria. Lipoteichoic acid (LTA) is a cell wall component of gram-positive bacteria. It is a potent inducer of inflammatory mediators in human dendritic cells, human pulmonary epithelial cells, and murine macrophages. However, the effect of LTA on human alveolar macrophages (AMs) which are the major effector cells in host defense against respiratory tract infections has hardly been studied. Statins have anti-inflammatory, immunomodulatory, antioxidative, anticoagulant, and antibacterial activities. These effects may be contributed to reduce the markers of systemic inflammation. Emerging retrospective studies have demonstrated that statin use decreased the mortality of pneumonia. However, the precise mechanisms responsible for these effects are unclear. The purpose of this study is to define the role of S. aureus LTA in human AMs and the effects of simvastatin (SV) on LTA-stimulated human AMs. The results showed that LTA induced tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), IL-8 mRNA expression, and suppressed IL-10 mRNA expression in human AMs. Simultaneously, LTA induced human AMs apoptosis. These effects were parallel with the up-regulation of the expression of NF-κB-P65 protein in the LTA-stimulated human AMs. The above effects of LTA on human AMs were inhibited significantly by SV. These data indicate that S. aureus LTA induces potent pro-inflammatory and pro-apoptotic effects on human AMs and statins exert anti-inflammatory effects by mediating inhibition of NF-κB activation and cytokine mRNA expression in human AMs. These results may explain, in part, the mechanisms responsible for favorable effects of statins on pneumonia.

STAT1 regulates MD-2 expression in monocytes of sepsis via miR-30a.

Sepsis is a major cause of morbidity and mortality in critically ill patients. MD-2 is a 25-kDa lipopolysaccharide (LPS)-binding protein that forms a heterodimer with TLR42, but its regulation in sepsis is not clear. This study aims to investigate the molecular mechanism of regulation of MD-2. Inflammation cytokines in monocytes were analyzed by real-time RT-PCR and ELISA, and it was found that IL-10 was elevated significantly in the monocytes with LPS treatment. And then, when the cells were treated with IL-10, STAT1 was activated in the monocytes using Western blotting. It was also found that STAT1 could enhance MD-2 expression on transcriptional and posttranscriptional levels. Finally, miR-30a was predicted to the molecule that may regulate STAT1 expression. It was verified that STAT1 was a new target gene of miR-30a. miR-30a could inhibit IL-10-induced cytokine release by targeting STAT1–MD-2 in monocytes. In conclusion, this study for the first time demonstrated that miR-30a inhibits MD-2 expression by targeting of STAT1 in human monocytes.

Elevated serum concentrations of HE4 as a novel biomarker of disease severity and renal fibrosis in kidney disease

Background Human epididymis protein 4 (HE4), has recently been reported as a mediator of renal fibrosis. However, serum HE4 levels appear in a large number of patient samples with chronic kidney disease (CKD), and the relationship of these levels to disease severity and renal fibrosis is unknown. Methods In 427 patients at different stages of CKD excluding gynecologic cancer and 173 healthy subjects, serum HE4 concentrations were tested by chemiluminescent microparticle immunoassay. Renal biopsy was performed on 259 of 427 subjects. Histological findings were evaluated using standard immunohistochemistry. Results The levels of serum HE4 were higher in CKD patients than in healthy subjects, and higher levels were associated with more severe CKD stages. Patients with more severe renal fibrosis tended to have higher HE4 levels, and correlation analysis showed a significant correlation between HE4 and degree of renal fibrosis (r = 0.938, P < 0.0001). HE4 can be a predictor of renal fibrosis in CKD patients; the area under the receiver-operating characteristic curve (AUC-ROC) was 0.99, higher than the AUC-ROC of serum creatinine (0.89). Conclusion Elevated levels of serum HE4 are associated with decreased kidney function, and also with an advanced stage of renal fibrosis, suggesting that HE4 may serve as a valuable clinical biomarker for renal fibrosis of CKD.

High serum haptoglobin level is associated with tumor progression and predicts poor prognosis in non-small cell lung cancer.

The overall survival time of non-small cell lung cancer (NSCLC) has not improved dramatically in recent decades. An important reason is the lacking of valuable biomarkers. Haptoglobin was reported to have activities of anti-inflammatory, anti-oxidant, autoimmune and tumor angiogenesis. However its potential role as a tumor biomarker was not well recognized. We used an immunoturbidimetry method to measure serum haptoglobin levels in 205 NSCLC patients, and 210 normal healthy controls. We found that serum haptoglobin levels were significantly elevated in NSCLC patients compared with normal healthy controls (1.985±1.039 mg/mLvs. 0.922 ± 0.495 mg/mL, respectively, P < 0.0001). Higher serum haptoglobin levels were associated with advanced TNM stage, lymph node metastasis, and distant metastasis. Area under receiver operating characteristic curve (ROC) for serum haptoglobin was 0.809 (95% CI: 0.767–0.852) at a specificity of 0.881 and sensitivity of 0.639. The optimal cut-off value of haptoglobin was 1.495 mg/mL for discriminating NSCLC from normal healthy controls. Kaplan-Meier log rank analysis revealed that the higher serum haptoglobin levels group had a poorer overall survival compared with lower haptoglobin group (the median survival was 12.0 weeks, 26.0 weeks, respectively, P < 0.01). Further univariate and multivariate Cox regression analysis showed that serum haptoglobin was an independent risk factor of prognosis of NSCLC patients (P < 0.01, P = 0.01, respectively). In conclusion, our study suggests that serum haptoglobin may act as useful clinical serological biomarkers in progression and prognostic evaluation in NSCLC.

Regulatory effects of miR-155 and miR-146a on repolarization and inflammatory cytokine secretion in human alveolar macrophages in vitro

Abstract Macrophages play an important role in inflammatory responses; however, miRNA-mediated repolarization of macrophages is essential for fulfilling this function. To clarify a series of changes at the RNA level in alveolar macrophages under normal and inflammatory conditions, bronchial alveolar lavage liquid (BALF) was collected from healthy volunteers or patients with pneumonia. This approach, which differs from that used in previously, provides more accurate information about the states of macrophages in different lung microenvironments. In this study, the density plots of macrophage subtypes (M1 and M2) in the BALF of healthy volunteers differed from that of the patients with pneumonia. The M2 subtype dominated in healthy volunteers and was rapidly repolarized to M1 in response to miRNA-mediated gene regulation. Differential miRNA expression in the two macrophage subtypes revealed lower expression of miR-155 and MIR-146a in patients with pneumonia compared with healthy volunteers; this may be related to inflammation and the use of anti-inflammatory drugs. We also found increased TNF-α and IL-6 expression at the RNA level, while macrophage galactose-type C-type lectin 1 (MGL-1) expression decreased with downregulation of miR-155 and miR-146a expression. These results indicate that the gene regulation mediated by miR-155 and miR-146a contributes to human alveolar macrophage phenotype repolarization, thus leading to an early switch from pro-inflammatory to anti-inflammatory cytokine production.

Serum human epididymis secretory protein 4 as a potential biomarker of renal fibrosis in kidney transplantation recipients

BACKGROUND Renal fibrosis remains an important cause of kidney allograft failure. The objective of this study was to evaluate the performance of serum human epididymis secretory protein 4 (HE4) as a biomarker for renal fibrosis in kidney transplant recipients. METHODS A total of 103 kidney transplantation patients were enrolled in this study, and serum HE4 concentrations were detected using the chemiluminescent microparticle immunoassay. Renal biopsy was carried out, and histological findings were assessed by immunohistochemistry. RESULTS Median serum HE4 concentrations were significantly increased in kidney transplant recipients (186.2 pmol/l, interquartile range [IQR] 125.6-300.2) compared with control subjects (34.3 pmol/l, IQR 30.4-42.3, p < 0.0001). Meanwhile, serum HE4 concentrations were significantly increased along with disease severity (p < 0.0001). In addition, we found serum HE4 concentrations to be strongly correlated with the severity of fibrosis (IF/TA 0, 1, 2, and 3: 114.3, 179.0, 197.8, and 467.8 pmol/l, respectively; p < 0.0001) and serum HE4 concentrations significantly correlated with HE4 tissue expression concentrations in renal biopsy. CONCLUSIONS Serum HE4 was increased in kidney transplant recipients with decreased kidney function and renal fibrosis and was correlated with the severity of the disease, suggesting that HE4 has the potential to be used as a novel clinical biomarker for evaluating kidney function and predicting renal fibrosis in kidney transplant recipients.