Reversal of cisplatin resistance by microRNA-139-5p-independent RNF2 downregulation and MAPK inhibition in ovarian cancer.

Some microRNAs (miRs) are dysregulated in cancers, and aberrant miR expression has been reported to correlate with chemoresistance of cancer cells. Therefore, the present study aims at investigating the effects of microRNA-139-5p (miR-139-5p) on cisplatin resistance of ovarian cancer (OC) with involvement of ring finger protein 2 (RNF2) and the mitogen-activated protein kinase (MAPK) signaling pathway. OC tissues were obtained from 66 primary OC patients. The cisplatin-sensitive A2780 and cisplatin-resistant A2780/DDP cell lines were collected for construction of RNF2 silencing and overexpressed plasmids. Cell vitality and apoptosis were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and annexin V-FITC/propidium iodide double-staining, respectively. Next, expression of RNF2, extracellular signal-related kinase, and p38 was determined by quantitative reverse transcription-quantitative polymerase chain reaction and Western blot analysis. Finally, the volume of xenograft tumors in BALB/c nude mice was detected. RNF2 and miR-139-5p were identified to be involved in OC. In addition, MAPK activation and RNF2 were related to cisplatin resistance of OC. miR-139-5p was downregulated in cisplatin-resistant OC tissues, and miR-139-5p overexpression could inhibit cell vitality, reduce cisplatin resistance, and promote apoptosis of OC cells. Furthermore, miR-139-5p combined with MAPK inhibitors more obviously reduced cisplatin resistance of OC. Taken together, this study demonstrated that miR-139-5p overexpression combined with inactivation of the MAPK signaling pathway can reverse the cisplatin resistance of OC by suppressing RNF2. Thus, miR-139-5p overexpression might be a future therapeutic strategy for OC.

MicroRNA-374b inhibits cervical cancer cell proliferation and induces apoptosis through the p38/ERK signaling pathway by binding to JAM-2.

Cervical cancer (CC) remains a highly prevalent cancer and mortality globally among women globally. The aim of the present study was to assess the ability of miR-374b to regulate CC cells through JAM-2, whilst exploring whether the underlying mechanism and its relation to the p38/ERK signaling pathway. During the study, microRNA-374b (miR-374b) was observed to have been expressed at a low level among CC tissues. Hence, a series of miR-374b mimics, miR-374b inhibitors, siRNA against JAM-2, SB202190 (an inhibitor for p38), and PD98059 (an inhibitor for ERK) were introduced to treat CC Siha cells and normal cervical Ect1/E6E7 cells. MTT, flow cytometry, scratch test, and transwell assays were applied to determine cell viability, apoptosis, migration, and invasion. The inhibitory role of the p38/ERK signaling pathway was observed in the CC cells treated with miR-374b mimics or siRNA against JAM-2. miR-374b mimic exposure was found to reduce cell viability, migration, and invasion, but induce apoptosis. MiR-374b inhibitor exposure was observed to have induced effects on the CC cells in a contrary manner to those induced by that of the miR-374b mimics. The key findings of the study demonstrated that miR-374b significantly inhibits cell proliferation, migration, and invasion through the blockade of the p38/ERK signaling pathway activation, as well as negatively binding to JAM-2, highlighting its potential as a therapeutic target for CC.

Correlations between pathologic subtypes/immunohistochemical implication and CT characteristics of lung adenocarcinoma ≤ 1 cm with ground-glass opacity.

OBJECTIVE: To discuss the correlation of pathologic subtypes and immunohistochemical implication with CT features of lung adenocarcinoma 1 cm or less in diameter with focal ground-glass opacity (fGGO). METHODS: CT appearances of 59 patients who underwent curative resection of lung adenocarcinoma ≤ 1 cm with fGGO were analyzed in terms of lesion location, size, density, shape (round, oval, polygonal, irregular), margin (smooth, lobular, spiculated, lobular and spiculated), bubble-like sign, air bronchogram, pleural tag, and tumor-lung interface. Histopathologic subtypes were classified according to International Association for the Study of Lung Cancer/ American Thoracic Society/European Respiratory Society classification of lung adenocarcinoma. Common molecular markers in immunohistochemical study included human epidermal growth factor receptor (HER)-1,HER-2,Ki-67, vascular endothelial growth factor (VEGF) and DNA topoisomerase 2Α.Patients' age and lesions' size and density were compared with pathologic subtypes using analysis of variance or nonparametric Wilcoxon tests. Patients' gender, lesion location, shape and margin, bubble-like sign, air bronchogram, pleural tag, and tumor-lung interface were compared with histopathologic subtypes and immunohistochemical implication using ψ² test or Fisher's exact test. RESULTS: The patients' gender, age, lesion location, shape, air bronchogram, pleural tag, and tumor-lung interface were not significantly different among different histopathologic subtypes (P=0.194, 0.126, 0.609, 0.678, 0.091, 0.374, and 0.339, respectively), whereas the lesion size,density,bubble-like sign, and margin showed significant differences (P=0.028, 0.002, 0.003, 0.046, respectively). The expression of Ki-67 significantly differed among nodules with different shapes(P=0.015). Statistically significant difference also existed between tumor-lung interface and HER-1 expression (P=0.019) and between bubble sign and HER-2 expression (P=0.049). CONCLUSIONS: Of lung adenocarcinoma ≤ 1 cm with fGGO,bubble-like sign occurs more frequently in invasive pulmonary adenocarcinoma and less frequently in atypical adenomatous hyperplasia. In addition, preinvasive lesions (atypical adenomatous hyperplasia and adenocarcinoma in situ) more frequently demonstrates smooth margin,while invasive lesions (minimally invasive adenocarcinoma and invasive pulmonary adenocarcinoma) more frequently demonstrates lobular and spiculated margin. Some CT features are associated with immunohistochemical implication of lung adenocarcinoma ≤ 1 cm with fGGO.

Value of coronary computed tomography angiography in ruling out coronary artery disease before intermediate- and high-risk non-cardiac surgery.

OBJECTIVE: To assess the value of preoperative coronary computed tomographic angiography (CCTA) in the detection of coronary artery disease (CAD) in patients planned to undergo non-cardiac surgery at intermediate or high risk to avoid unnecessary invasive coronary angiography (ICA). METHODS: The study protocol was approved by our institutional review board and informed consent was given. In this prospective study, 157 consecutive patients who underwent CCTA before undergoing non-cardiac surgery at intermediate or high risk was involved. The non-cardiac surgery included high-risk surgery (17 patients) and intermediate-risk surgery (140 patients). Follow-up was performed in 6-11 months to define cardiac events described as acute coronary syndrome (ACS) or death secondary to ASC, arrhythmias, cardiac revascularization, or cardiac failure. χ(2) test was performed to compare the differences in incidence of cardiac events among patients who had undergone or who had not undergone preoperative ICA. RESULTS: CCTA was of diagnostic value in 145 of 157 patients. Thirty-seven of 145 had no CAD, and 88 of 145 had no significant CAD (<50% stenosis), and non-cardiac surgery was performed in them without preoperative ICA. No patients in those patients had postoperative ischemic events at follow-up; 20 had significant CAD (≥50% stenosis) and underwent surgery after preoperative ICA. CCTA was non-diagnostic in 12 patients who were referred for preoperative ICA, and 4 of 12 underwent surgery after PCI or CABG. There were no differences in cardiac events between patients who had undergone preoperative ICA and those who had not (P=0.45). CONCLUSIONS: In patients with planned non-cardiac surgery at medium or high risk of cardiovascular events, preoperative CCTA is an effective diagnostic tool for detecting CAD. Preoperative ICA can be safely avoided in patients with normal findings or with stenosis<50% in CCTA.

Saponins from Aralia taibaiensis attenuate D-galactose-induced aging in rats by activating FOXO3a and Nrf2 pathways.

Reactive oxygen species (ROS) are closely related to the aging process. In our previous studies, we found that the saponins from Aralia taibaiensis have potent antioxidant activity, suggesting the potential protective activity on the aging. However, the protective effect of the saponins and the possible underlying molecular mechanism remain unknown. In the present study, we employed a D-galactose-induced aging rat model to investigate the protective effect of the saponins. We found that D-galactose treatment induced obvious aging-related changes such as the decreased thymus and spleen coefficients, the increased advanced glycation end products (AGEs) level, senescence-associated ß-galactosidase (SAß-gal) activity, and malondialdehyde (MDA) level. Further results showed that Forkhead box O3a (FOXO3a), nuclear factor-erythroid 2-related factor 2 (Nrf2), and their targeted antioxidants such as superoxide dismutase 2 (SOD2), catalase (CAT), glutathione reductase (GR), glutathione (GSH), glutamate-cysteine ligase (GCL), and heme oxygenase 1 (HO-1) were all inhibited in the aging rats induced by D-galactose treatment. Saponins supplementation showed effective protection on these changes. These results demonstrate that saponins from Aralia taibaiensis attenuate the D-galactose-induced rat aging. By activating FOXO3a and Nrf2 pathways, saponins increase their downstream multiple antioxidants expression and function, at least in part contributing to the protection on the D-galactose-induced aging in rats.

Glycoprotein nonmetastatic B as a prognostic indicator in small cell lung cancer.

Glycoprotein nonmetastatic melanoma B (GPNMB) is a type I transmembrane glycoprotein which is overexpressed in many tumors and seems to play a critical role in metastasis of malignant tumors. The purpose of this study was to determine GPNMB expression in small cell lung cancer (SCLC) and analyze the prognostic value in patients with SCLC. A total of 132 cases of SCLCs were analyzed immunohistochemically on tissue microarrays (TMAs). Patients were divided into weak-positive and strong-positive GPNMB groups. In addition, serum GPNMB was evaluated by enzyme-linked immunosorbent assay (ELISA). The average serum GPNMB concentration was 1054.15 ± 363.71 pg/mL in the weak-positive group, 2611.52 ± 457.57 pg/mL in the strong-positive group, and 427.61 ± 273.9 pg/mL in the control. The strong-positive group showed significantly higher serum GPNMB levels than the weak-positive group and healthy control (p < 0.01). Overall survival in the weak-positive GPNMB group was significantly longer than in the strong-positive group (27 months vs 15 months, p < 0.01). These results suggest that the expression of GPNMB may be useful as a prognostic indicator in patients with SCLC.

Ischemic neurons activate astrocytes to disrupt endothelial barrier via increasing VEGF expression.

Blood-brain barrier (BBB) disruption occurring within the first few hours of ischemic stroke onset is closely associated with hemorrhagic transformation following thrombolytic therapy. However, the mechanism of this acute BBB disruption remains unclear. In the neurovascular unit, neurons do not have direct contact with the endothelial barrier; however, they are highly sensitive and vulnerable to ischemic injury, and may act as the initiator for disrupting BBB when cerebral ischemia occurs. Herein, we employed oxygen-glucose deprivation (OGD) and an in vitro BBB system consisting of brain microvascular cells and astrocytes to test this hypothesis. Neurons (CATH.a cells) were exposed to OGD for 3-h before co-culturing with endothelial monolayer (bEnd 3 cells), or endothelial cells plus astrocytes (C8-D1A cells). Incubation of OGD-treated neurons with endothelial monolayer alone did not increase endothelial permeability. However, when astrocytes were present, the endothelial permeability was significantly increased, which was accompanied by loss of occludin and claudin-5 proteins as well as increased vascular endothelial growth factor (VEGF) secretion into the conditioned medium. Importantly, all these changes were abolished when VEGF was knocked down in astrocytes by siRNA. Our findings suggest that ischemic neurons activate astrocytes to increase VEGF production, which in turn induces endothelial barrier disruption.

Poly(ADP-ribose) polymerase-1 inhibition by arsenite promotes the survival of cells with unrepaired DNA lesions induced by UV exposure.

Human arsenic exposure is associated with increased risk of skin cancer, and arsenite greatly enhances ultraviolet (UV)-induced skin tumors in a mouse model of carcinogenesis. Inhibition of DNA repair is one proposed mechanism for the observed cocarcinogenicity. We have previously demonstrated that low concentrations of arsenite inhibit poly(ADP-ribose) polymerase (PARP)-1, thus interfering with DNA repair process triggered by UV radiation. Because overactivation of PARP-1 often leads to apoptotic cell death, and unrepaired DNA lesions promote genomic instability and carcinogenesis, we hypothesized that inhibition of PARP-1 by arsenic may promote the survival of potentially "initiated carcinogenic cells," i.e., cells with unrepaired DNA lesions. In the present study, we tested this hypothesis on UV-challenged HaCat cells. Cells were pretreated with 2µM arsenite for 24 h before UV exposure. Outcome parameters included apoptotic death rate, PARP-1 activation, apoptotic molecules, and retention of DNA lesions. UV exposure induced PARP-1 activation and associated poly(ADP-ribose) production, apoptosis-inducing factor release, cytochrome C release, and caspases activation, which led to apoptotic death in HaCat cells. Pretreatment with 2µM arsenite significantly inhibited UV-induced cell death as well as the associated molecular events. Notably, knockdown of PARP-1 with small interfering RNA completely abolished the antagonism of arsenite. Furthermore, arsenite pretreatment led to long-term retention of UV-induced cyclobutane pyrimidine dimers. Together, these results suggest that low concentration of arsenite reduces UV-induced apoptosis via inhibiting PARP-1, thus promoting the survival of cells with unrepaired DNA lesions, which may be an important mechanism underlying arsenic cocarcinogenic action.

The dysfunction of ATPases due to impaired mitochondrial respiration in phosgene-induced pulmonary edema.

Phosgene is a toxic gas that is widely used in modern industry, and its inhalation can cause severe pulmonary edema. There is no effective clinical treatment because the mechanism of phosgene-induced pulmonary edema still remains unclear. Many studies have demonstrated that the Na(+)/K(+)-ATPase plays a critical role in clearing pulmonary edema and the inhibition of Na(+)/K(+)-ATPase protein expression has been found in many other pulmonary edema models. In the present study, after the mice were exposed to phosgene, there was serious pulmonary edema, indicating the dysfunction of the ATPases in mice. However, in vitro enzyme study showed that there were increases in the activities of the Na(+)/K(+)-ATPase and Ca(2+)-ATPase. Further investigation showed that the ATP content and mitochondrial respiratory control ratio (RCR) in the lungs decreased significantly. The oxidative stress product, malondialdehyde (MDA), increased while the antioxidants (GSH, SOD, and TAC) decreased significantly. These results indicate that mitochondrial respiration is the target of phosgene. The dysfunction of ATPases due to impaired mitochondrial respiration may be a new mechanism of phosgene-induced pulmonary edema.

Preparation and characterization of a set of monoclonal antibodies to TRAIL and TRAIL receptors DR4, DR5, DcR1, and DcR2.

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo 2L) is a novel cytotoxic ligand belonging to TNF superfamily. Among TRAIL receptors, death receptor 4 (DR4) and DR5 containing death domain (DD) in their cytoplasmic region mediate apoptosis-signaling upon TRAIL binding, while decoy receptor 1 (DcR1) and DcR2 with a truncated or non-functional DD play "decoy" role. The interaction of TRAIL and TRAIL receptors plays important roles both in immunoregulation and immune pathogenesis of some diseases. In this study, we raised hybridomas secreting monoclonal antibodies against TRAIL (FMU1.1, 1.2, 1.3), DR4 (FMU1.4), DR5 (FMU1.5, 1.6), DcR1 (FMU1.7) and DcR2 (FMU1.8, 1.9). These MAbs could be used for fluorescent staining and flow cytometry (FCM) analysis as well as immunohistochemistry (IHC). Moreover, FMU1.1, 1.3, 1.4 and 1.5 could be used as coating antibodies paring corresponding polyclonal antibodies to develop sandwich ELISAs to quantitate the soluble TRAIL (sTRAIL), sDR4 or sDR5 in serum samples respectively. In addition, cross-linking of DR4/DR5 by FMU1.4 or FMU1.5 MAbs could induce apoptosis of some DR4/DR5-expressing tumor cells. Thus, this set of monoclonal antibodies against TRAIL or TRAIL receptors may be useful in expression phenotypic and functional study of TRAIL and TRAIL receptors.

[Effects of perindopril on plasma soluble TRAIL and receptor soluble DR5 in patients with congestive heart failure].

AIM: To explore the levels of soluble TRAIL and DR5 in plasma of patients with congestive heart failure (CHF) and the effects of perindopril. METHODS: 58 CHF patients were randomly divided into two groups, namely perindopril treatment group (30 cases) and routine treatment group (28 cases). The levels of sTRAIL and sDR5 in plasma of 30 CHF patients treated with perindopril, 28 CHF patients treated with routine method before and after treatment and 20 healthy persons were detected by ELISA. RESULTS: (1)The mean levels of sTRAIL in plasma of 58 CHF patients and 20 healthy persons were (1.43+/-0.47) microg/L and (0.93+/-0.12) microg/L, respectively, the comparison between the patients and healthy persons had no notable difference (P>0.05), suggesting that plasma sTRAIL level had no significant relation to injured level of cardiac function. As for sDR5 level, the mean level in plasma of 58 CHF patients was (39.67+/-6.78) ng/L, this value was significantly higher than that of healthy control group, and the level of sDR5 was increased with the injured level of cardic function.(2)The plasma levels of sTRAIL in both perindopril group and conventional treatment group decreased after treatment, but there was no significant difference. The mean levels of plasma sDR5 in perindopril group were (31.23+/-10.16 ) ng/L and (8.50+/-2.14) ng/L; the levels in conventional group (48.81+/-8.74) ng/L and (26.64+/-6.27) ng/L, respectively, the perindopril group was lower than the conventional group descending rates were 72.7% and 45.3% respectively.(3)The level of plasma sDR5 in CHF patients resulting from hypertensive cardiopathy was much higher than that in CHF patients resulting from any other etiological factors. CONCLUSION: DR5 may play an important role in the occurrence and progress of myocardium apoptosis of CHF patients. Perindopril can down-regulate the level of plasma sDR5, therefore, it may have the great effect on retarding course of ventricular remodeling, protecting and improving cardial function of CHF patients.