Roles of miR-200 family members in lung cancer: more than tumor suppressors.

miRNAs are a class of single-stranded noncoding RNAs, which have no coding potential, but modulate many molecular mechanisms including cancer pathogenesis. miRNAs participate in cell proliferation, differentiation, apoptosis, as well as carcinogenesis or cancer progression, and their involvement in lung cancer has been recently shown. They are suggested to have bidirectional functions on important cancer-related genes so as to enhance or attenuate tumor genesis. Epithelial-mesenchymal transition (EMT) is a fundamental process which contributes to integrity of organogenesis and tissue differentiation as well as tissue repair, organ fibrosis and the progression of carcinoma, and several miRNAs were suggested to form the network regulating EMT in lung cancer, among which, miR-200 family members (miR-200a, miR-200b, miR-200c, miR-429 and miR-141) play crucial roles in the suppression of EMT.

miR-33a levels in hepatic and serum after chronic HBV-induced fibrosis.

BACKGROUND: Chronic hepatitis B virus (HBV) infection, which can lead to hepatic disease, has become a critical national healthcare problem, and many people die each year as a result of HBV infection and its complications. Although microRNA-33a (miR-33a) is a novel modulator of lipid and cholesterol metabolism, the role of miR-33a in the hepatic fibrogenesis is still unknown. Here, we aimed to explore the roles and mechanisms of miR-33a in liver fibrosis. METHODS: miR-33a expression in whole liver and serum samples was measured from chronic hepatitis B (CHB) patients by quantitative real-time PCR (qRT-PCR). In addition, different murine hepatic fibrosis models were produced to consolidate the results in human tissue. Human and murine primary liver fibrosis-associated cells were isolated and treated with transforming growth factor-ß1 (TGF-ß1). RESULTS: miR-33a expression levels in liver tissue significantly increased with a fibrosis progression manner in the human liver. Furthermore, serum miR-33a levels associated positively with progressing process of hepatic fibrosis. miR-33a was in particular increased in hepatic stellate cells (HSC) than other liver fibrosis-associated cells. Stimulation of HSCs with TGF-ß1 leads to a critical increase of miR-33a. Increasing miR-33a levels increased (whereas inhibiting miR-33a weakened) the activation role of TGF-ß1 in LX-2 cells, which might be a potential mechanism through moderating Smad7 expression. CONCLUSIONS: miR-33a may be a novel marker for HSC activation and hepatic fibrosis progress, suggesting a new therapeutic target in liver fibrosis.

[Expression and clinical significance of circadian gene Per2 in non-small cell lung cancer].

OBJECTIVE: To detect the expression of Per2 in non-small cell lung cancer (NSCLC), and analyze its clinical significance. METHODS: The expression of Per2 was determined in 60 NSCLC and 20 normal lung tissues by immunohistochemical assay, and the relationship between Per2 expression and clinicopathological features was analyzed. RESULTS: The positive expression rates of Per2 in NSCLC and normal lung tissues were 71.7% and 95.0%, respectively (P < 0.05). The expression of Per2 in NSCLC was correlated with pathological differentiation and TNM stage (P < 0.05). CONCLUSION: The expression of Per2 in NSCLC is decreased. The negative expression of Per2 may contribute to the development and invasion in NSCLC.

Unloading the infarcted heart affect MMPs-TIMPs axis in a rat cardiac heterotopic transplantation model.

Ventricular assist devices may function as a bridge to recovery or heart transplantation, however, little is known about its mechanisms. This study examined the role of matrix metalloproteinases (MMP)-tissue inhibitors of metalloproteinases (TIMP) axis in the process of recovery after unloading in a rat ischemic-induce heart failure (HF) model. Myocardial infarction model was created with the coronary artery ligation. The infarcted rats hearts were unloaded by heterotopic cardiac transplantation (n=14). 2 weeks later, the function of normal and infarcted hearts with or without loading was evaluated by Langendorff perfusion model. The hearts were then harvested and prepared for the study of expression of MMPs and TIMPs. Developed pressure in the unloading group was higher than the loading group (P=0.0074). Unloading increased the ratio of TIMP-1-MMP-1(1.38±0.11 vs. 0.76±0.09, P<0.05), TIMP-2-MMP-2 (1.06±0.10 vs. 0.33±0.07, P<0.01), TIMP-3-MMP-9(1.07±0.08 vs. 0.59±0.06, P<0.05). Although MMP-1, 2, 9 were downregulated (P<0.01, 0.01, 0.05, respectively), TIMP-2 and TIMP-3 upregulated (P<0.01, 0.05, respectively), MMP-7 and TIMP-1 was not affected significantly. The infarcted cardiac function could be improved by unloading. It was attributed to downregulation of MMP-1, 2 and 9, and upregulation of TIMP-2 and -3, and furthermore, the ratio of TIMPs to MMPs was increased, which might be more sensitive than sole MMPs or TIMPs for the judgment of myocardial matrix homeostasis.

[miRNA changes in the reverse remodeling heart of rats].

OBJECTIVE: To establish a reverse remodeling heart model in rats and observe collagen and TGF-ß expression and relevant microRNAs changes during reverse remodeling. METHODS: Lewis rats were divided into four groups including sham (NL, n = 10), abdominal aortic constriction (AAC, n = 10), heterotopic transplantation of abdominal aortic constriction (AAC-HT, n = 9) and heterotopic transplantation of normal heart (HT, n = 8). Left ventricular wall thickness and LV cavity were measured by echocardiography. The cardiomyocyte cross-sectional area (CSA) was determined on HE stained sections. Immunohistochemical and qRT-PCR were used to detect collagen and TGF-ß expressions. miRNAs were detected by MicroRNA microarray. RESULTS: Heart weight, left ventricular wall thickness and CSA were significantly increased in AAC hearts compared to those in the NL and AAC-HT hearts. The collagen and TGF-ß were increased in AAC hearts and further increased in AAC-HT hearts. miRNA microarray evidenced more than two folds changes on 82 miRNAs compared to NL (10 in AAC, 32 in AAC-HT and 40 in HT). CONCLUSION: Rat abdominal aortic constriction and heterotopic transplantation could be used as a reverse remodeling heart model and significant collagen and TGF-ß as well microRNA expression changes were evidenced in this model.

MicroRNA-155 silencing enhances inflammatory response and lipid uptake in oxidized low-density lipoprotein-stimulated human THP-1 macrophages.

It has been proposed that the inflammatory response of monocytes/macrophages induced by oxidized low-density lipoprotein (oxLDL) is a key event in the pathogenesis of atherosclerosis. MicroRNA-155 (miR-155) is an important regulator of the immune system and has been shown to be involved in acute inflammatory response. However, the function of miR-155 in oxLDL-stimulated inflammation and atherosclerosis remains unclear. Here, we show that the exposure of human THP-1 macrophages to oxLDL led to a marked up-regulation of miR-155 in a dose-dependent manner. Silencing of endogenous miR-155 in THP-1 cells using locked nucleic acid-modified antisense oligonucleotides significantly enhanced oxLDL-induced lipid uptake, up-regulated the expression of scavenger receptors (lectinlike oxidized LDL receptor-1, cluster of differentiation 36 [CD36], and CD68), and promoted the release of several cytokines including interleukin (IL)-6, -8, and tumor necrosis factor α (TNF-α). Luciferase reporter assay showed that targeting miR-155 promoted nuclear factor-kappa B (NF-κB) nuclear translocation and potentiated the NF-κB-driven transcription activity. Moreover, miR-155 knockdown resulted in a marked increase in the protein amount of myeloid differentiation primary response gene 88 (MyD88), an important adapter protein used by Toll-like receptors to activate the NF-κB pathway. Our data demonstrate that miR-155 serves as a negative feedback regulator in oxLDL-stimulated THP-1 inflammatory responses and lipid uptake and thus might have potential therapeutic implications in atherosclerosis.

[Concurrent standard dose of cisplatin, paclitaxel, and radiotherapy followed by surgery in treatment of thoracic esophageal carcinoma].

OBJECTIVE: To investigate the curative effect of incorporation of the regimen of standard dose of paclitaxel combined with cisplatin into concurrent radiotherapy as pre-operative treatment for patients with esophageal carcinoma. METHODS: Twenty-six patients with primary diagnosis of esophageal carcinoma, 17 in stage II and 9 in stage III, underwent conventional fractionated radiotherapy with a total dosage of 40 Gy (2 Gy per day, 5 doses per week). Paclitaxel were given intravenously at a dose of 135 mg/m(2) for 3 h on day1 and day 22. Cisplatin was given intravenously at a dose of 20 mg/m(2) on D1-D3 and D22-24. 4 - 6 weeks after the completion of chemo-radiotherapy, left thoracic incision and transhiatal esophagectomy with anastomosis in the neck was performed. The patients were followed up for 42.28 months. Kaplan-Meier method was used to analyze the overall survival (OS) and disease-free survival (DFS), and Log-rank test was performed to assess the survival rates statistical significance among groups. RESULTS: The radical resection rate was 96.15%. The pathologic response to chemoradiotherapy were grade I in 9 patients, grade II in 6 patients, and grade III in 11 patients. The pathological complete remission (PCR) rate was 42.31% (11/26). Toxicity grade 3 - 4 included leucopenia (7.69%, 2/26), thrombocytopenia (7.69%, 2/26), and radiation esophagitis (11.54%, 3/26). Surgery-related complications included anastomotic leakage (3.85%, 1/26), recurrent laryngeal nerve injury (7.69%, 2/26), and chylothorax (3.85%, 1/26). The 3- and 5-year overall survival rates were 62.96% and 54.56% respectively. The 3- and 5-year disease-free survival rates were 59.94% and 55.65% respectively. The 3-year overall survival rates of the patients with different pathologic responses were 25.40% (for those of grade I), 60% (for grade II), and 90.91% (for grade III) respectively (P < 0.05). The 5-year overall survival rates were 0 (for grade I), 60% (for grade II), and 81.82% (for grade III) respectively (P < 0.05). CONCLUSION: Preoperative chemoradiotherapy containing full dose of paclitaxel and cisplatin increases the 5-year overall survival for the patients with postoperative pathologic response grade II and above, and does not increase the treatment-related complications.