WNT6 participates in the occurrence and development of ovarian cancer by upregulating/activating the typical Wnt pathway and Notch1 signaling pathway

Wnt/β-catenin pathway is associated with the progression of various cancers such as gastric cancer, colorectal cancer, and endometrial cancer. Using the Kaplan-Meier Plotter database, we found that WNT6 was associated with progression-free survival (PFS) outcomes. Immunohistochemical analysis of ovarian cancer samples and normal ovaries showed that the expression of WNT6 protein was significantly increased in ovarian cancer samples. Further, we explored the possible role of WNT6 in the occurrence and development of ovarian cancer. Our results showed that the mRNA and protein expression of WNT6 were significantly higher in CAOV3 and OVCAR3 cells compared with other ovarian cancer cell lines and normal ovarian cell line IOSE-80 as well. The transformation of CAOV3 and OVCAR3 cells with short interfering WNT6 (siWNT6) significantly inhibited their proliferation and lamellipodia formation, causing cell cycle arrest and promoting cell apoptosis. Western blot experiments confirmed that the down-regulation of WNT6 inhibited the expression of β-catenin and Notch1. These results suggest that WNT6 plays an important role in the occurrence and development of ovarian cancer.

The lncRNA MALAT1 participates in regulating coronary slow flow endothelial dysfunction through the miR-181b-5p-MEF2A-ET-1 axis

BACKGROUND

Coronary slow flow (CSF) refers to coronary arteries with no obvious stenosis but have slow coronary flow without effective treatment. The main cause of CSF is endothelial dysfunction. The long non-coding RNA (lncRNA) MALAT1 is involved in regulating endothelial dysfunction, but its role in CSF endothelial dysfunction is still unclear.

METHODS

We included 41 CSF patients and 37 controls in the study, who all underwent coronary angiography, echocardiography, and brachial artery flow-mediated dilatation (FMD) examination. Human umbilical vein endothelial cells (HUVECs) stimulated by oxygen-glucose deprivation were used as CSF-induced HUVECs. Plasma endothelin-1 (ET-1) concentrations were determined by enzyme-linked immunosorbent assay (ELISA). The expression levels of MALAT1, miR-181b-5p, myocyte enhancer factor 2A (MEF2A), and ET-1 were measured by qRT-PCR or western blotting. Cell proliferation was determined by 5-ethynyl-2'-deoxyuridine (EdU) and Cell Counting Kit-8 (CCK-8) assays. Apoptosis was examined by flow cytometry. The relationship between miR-181b-5p and MALAT1 or MEF2A was verified by dual-luciferase reporter assay. MEF2A binding directly to the ET-1 promoter region was verified via chromatin immunoprecipitation (ChIP) assay.

RESULTS

MALAT1 and ET-1 were increased, and miR-181b-5p was decreased in the peripheral blood of the CSF patients, and could be used as predictors of CSF. In the CSF-induced HUVECs, MALAT1 was highly expressed, and MALAT1 knockdown improved endothelial function. In contrast, miR-181b-5p was downregulated in the CSF-induced HUVECs, and miR-181b-5p overexpression improved endothelial function. While MEF2A was highly enriched in CSF-induced HUVECs, MEF2A knockdown reduced ET-1 and increased the endothelial function of CSF-induced HUVECs as a transcriptional regulator of ET-1. MALAT1 modulated MEF2A expression positively by sponging miR-181b-5p.

CONCLUSIONS

Endothelial function is reduced in CSF. MALAT1 participates in regulating CSF endothelial dysfunction through the miR-181b-5p-MEF2A-ET-1 axis, and could provide a new target for CSF treatment.

CircPUM1 promotes the malignant behavior of lung adenocarcinoma by regulating miR-326

CircRNAs are reported to be implicated in the development of lung cancer. This study focused on assessing the expression, functions and molecular mechanism of circPUM1 in lung adenocarcinoma. Here, it showed that circPUM1 is significantly upregulated in both lung adenocarcinoma cell lines and tissues. Furthermore, silencing of circPUM1 impaired the proliferation, migration and invasion ability, and increased apoptosis in A549 cells. Nevertheless, overexpression of circPUM1 in SPC-A1 cells has the opposite effect. Silencing of circPUM1 inhibits the tumorigenesis in nude mice. Mechanistically, circPUM1 could sponge miR-326 and promote the expression of its downstream proteins Cyclin D1 and Bcl-2. In summary, this present study revealed that circPUM1 functions as an oncogene to promote the tumorigenesis of lung adenocarcinoma through circPUM1/miR-326/Cyclin D1 and Bcl-2 axis. This indicates that circPUM1 may act as a potential therapeutic target for lung adenocarcinoma.

Yes-associated protein (YAP) binds to HIF-1α and sustains HIF-1α protein stability to promote hepatocellular carcinoma cell glycolysis under hypoxic stress

BACKGROUND

Hypoxia-inducible factor 1α (HIF-1α) is essential in hepatocellular carcinoma (HCC) glycolysis and progression. Yes-associated protein (YAP) is a powerful regulator and is overexpressed in many cancers, including HCC. The regulatory mechanism of YAP and HIF-1α in HCC glycolysis is unknown.

METHODS

We detected YAP expression in 54 matched HCC tissues and the adjacent noncancerous tissues. The relationship between YAP mRNA expression and that of HIF-1α was analyzed using The Cancer Genome Atlas HCC tissue data. We cultured HepG2 and Huh7 HCC cells under normoxic (20% O2) and hypoxic (1% O2) conditions, and measured the lactate and glucose levels, migration and invasive capability, and the molecular mechanism of HCC cell glycolysis and progression.

RESULTS

In this study, we detected YAP expression in 54 matched HCC tissues and the adjacent noncancerous tissues. We observed that hypoxia-induced YAP activation is crucial for accelerating HCC cell glycolysis. Hypoxia inhibited the Hippo signaling pathway and promoted YAP nuclear localization, and decreased phosphorylated YAP expression in HCC cells. YAP knockdown inhibited HCC cell glycolysis under hypoxic. Mechanistically, hypoxic stress in the HCC cells promoted YAP binding to HIF-1α in the nucleus and sustained HIF-1α protein stability to bind to PKM2 gene and directly activates PKM2 transcription to accelerate glycolysis.

CONCLUSIONS

Our findings describe a new regulatory mechanism of hypoxia-mediated HCC metabolism, and YAP might be a promising therapeutic target in HCC.

Cardiac contractility modulation improves left ventricular systolic function partially via miR-25 mediated SERCA2A expression in rabbit trans aortic constriction heart failure model

The purpose of this study was to investigate the underlying mechanism of cardiac contractility modulation (CCM) in improving trans aortic constriction (TAC)-induced heart failure (HF) left ventricular (LV) systolic function. A total of 25 New Zealand white rabbits were randomly divided into 5 groups: sham operation group (SHM), TAC-induced HF group (HF), TAC-induced HF followed by CCM stimulation group (HF + CCM), TAC-induced HF followed by injection of anti-miR-25 group (HF + anti-miR-25), TAC-induced HF followed by CCM stimulation and AAV9-miR-25 injection group (HF + CCM + miR-25). CCM current was performed 6 hours a day for 4 weeks. The left ventricle ejection fraction (LVEF) was measured by ultrasound. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used for measuring RNA and protein levels. The sarcoplasmic reticulum calcium ATPase (SERCA2A) and LVEF were reduced, while the miR-25 expression was improved in HF group compared to SHM group. Conversely, the SERCA2A and LVEF were improved, and the miR-25 reduced in the HF + CCM and the HF + anti-miR-25 groups compared to the HF group. Moreover, the SERCA2A and LVEF were reduced, while the miR-25 was improved in the HF + CCM + miR-25 group compared to the HF + CCM group. CCM is a potentially effective procedure for improving LV systolic function, which might partially by inhibiting miR-25 expression, further improved SERCA2A expression in TAC HF models.

Transforming growth factor-beta1 suppresses hepatocellular carcinoma proliferation via activation of Hippo signaling

In this study, we examined the expression of core proteins of the Hippo signaling pathway in hepatocellular carcinoma (HCC) cells treated with transforming growth factor-β 1(TGF-β1) and investigated the relationship between TGF-β1 and the Hippo signaling pathway, in order to better understand their roles in HCC and their potential implications for cancer therapy. We prove that the Hippo signaling pathway is involved in the TGF-β1-induced inhibition of the growth of HCC cells. Large tumor suppressor expression (LATS1) was overexpression and yes association protein 1(YAP1) translocated from the nucleus to the cytoplasm in HCC cells treated with TGF-β1. Overexpression of LATS1 and the nucleocytoplasmic translocation of YAP1 play an anti-oncogenetic role in the occurrence and development of liver cancer. Our findings provide new insight into strategies for liver cancer therapy.

Autophagy promotes metastasis and glycolysis by upregulating MCT1 expression and Wnt/β-catenin signaling pathway activation in hepatocellular carcinoma cells

Background

Autophagy is a dynamic physiological process that can generate energy and nutrients for cell survival during stress. Autophagy can regulate the migration and invasive ability in cancer cells. However, the connection between autophagy and metabolism is unclear. Monocarboxylate transporter 1 (MCT1) plays an important role in lactic acid transport and H⁺ clearance in cancer cells, and Wnt/β-catenin signaling can increase cancer cell glycolysis. We investigated whether autophagy promotes glycolysis in hepatocellular carcinoma (HCC) cells by activating the Wnt/β-catenin signaling pathway, accompanied by MCT1 upregulation.

Methods

Autophagic activity was evaluated using western blotting, immunoblotting, and transmission electron microscopy. The underlying mechanisms of autophagy activation on HCC cell glycolysis were studied via western blotting, and Transwell, lactate, and glucose assays. MCT1 expression was detected using quantitative reverse transcription–PCR (real-time PCR), western blotting, and immunostaining of HCC tissues and the paired adjacent tissues.

Results

Autophagy promoted HCC cell glycolysis accompanied by MCT1 upregulation. Wnt/β-catenin signaling pathway activation mediated the effect of autophagy on HCC cell glycolysis. β-Catenin downregulation inhibited the autophagy-induced glycolysis in HCC cells, and reduced MCT1 expression in the HCC cells. MCT1 was highly expressed in HCC tissues, and high MCT1 expression correlated positively with the expression of microtubule-associated protein light chain 3 (LC3).

Conclusion

Activation of autophagy can promote metastasis and glycolysis in HCC cells, and autophagy induces MCT1 expression by activating Wnt/β-catenin signaling. Our study describes the connection between autophagy and glucose metabolism in HCC cells and may provide a potential therapeutic target for HCC treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0673-y) contains supplementary material, which is available to authorized users.

Promotion of glycolysis by HOTAIR through GLUT1 upregulation via mTOR signaling

The long non-coding RNA HOX transcript antisense RNA (HOTAIR) plays a key role in the progression of various carcinomas. However, whether or not HOTAIR influences glucose metabolism and the specific underlying mechanism in hepatocellular carcinoma (HCC) cells remain unclear. In the present study, we found markedly increased HOTAIR expression in 84 HCC tissues and demonstrated that HOTAIR overexpression promoted cell proliferation using Cell Counting Kit-8. The effect on glucose metabolism regulated by HOTAIR in HCC cells was determined by detecting lactate and glucose levels: HOTAIR promoted glycolysis by upregulating glucose transporter isoform 1 (GLUT1) and activating mammalian target of rapamycin (mTOR) signaling, whereas knockdown of HOTAIR suppressed this effect. Our research reveals a novel relationship between HOTAIR and glucose metabolism in HCC cells, and it may be a therapeutic target for diagnosing and treating HCC.

[Alterations of SP-A, SP-D and KL-6 in serum and bronchoalveolar lavage fluid in children with Mycoplasma pneumoniae pneumonia]

OBJECTIVE

To study the alterations and relationship of surfactant protein (SP)-A, SP-D and KL-6 in serum and bronchoalveolar lavage fluids (BALF) in children with Mycoplasma pneumoniae pneumonia (MPP).

METHOD

Self-control method was used for the study on SP-A, SP-D and KL-6 in serum, infected and non-infected BALFs in 32 MMP children with only one side of MPP.

RESULT

The contents of SP-A, SP-D and KL-6 in infected BALF were [mg/L;M (IQR) ]: 243 (90-468) , 187 (43-333) , 148 (47-426) ;104 (37-257) , 56 (25-131) , 35 (12-147) in non-infected BALF; 35 (25-69) , 33 (9-149) and 24 (15-62) in serum. The correlation coefficient of KL-6 between serum and infected BALF were -0.534 and -0.378 (P < 0.05).

CONCLUSION

There were significant correlation between the alterations of SP-A, SP-D and KL-6 in serum and lung infection in children with CAP. KL-6 in serum may be more sensitive than SP-A and SP-D.

AURKB and MAPK involvement in the regulation of the early stages of mouse zygote development

Aurora kinases have become a hot topic for research as they have been found to play an important role in various stages of mitotic cell division and to participate in malignant conversions of tumors. The participation of Aurora kinases in the regulation of oocyte meiosis has been recently reported, but their participation in mammalian early embryonic development remained unclear. The object of our study was to establish the spatio-temporal expression pattern of Aurora kinase B (AURKB) in mouse zygotes during the first cleavage, to reveal its functions in the early development of mouse zygotes, and to define the involvement of AURKB in mitogen-activated protein kinase (MAPK) signaling. Our results showed that in mouse zygotes AURKB expression increased in G1 phase and peaked in M phase. AURKB protein distribution was found to be in association with nuclei and distributed throughout the cytoplasm in a cell cycle-dependent manner. Functional disruption of AURKB resulted in abnormal division phenotypes or mitotic impairments. U0126, a specific mitogen-activated protein kinase kinase (MEK) inhibitor, caused significantly altered morphologies of early embryos together with a decrease in protein expression and kinase activity of AURKB. Our results indicated that the activity of AURKB was required for regulating multiple stages of mitotic progression in the early development of mouse zygotes and was correlated with the activation of the MAPK pathway.

Detection of p16 promoter methylation in premature rats with chronic lung disease induced by hyperoxia

BACKGROUND

The aim of the present study was to investigate p16 promoter methylation in premature rats with chronic lung disease (CLD) induced by hyperoxia.

METHODS

Eighty Wistar rats were randomized into the hyperoxia group (fraction of inspired oxygen [FiO(2)] = 900 mL/L) or the control group (FiO(2) = 210 mL/L), 40 for each group. Semi-nested methylation-specific polymerase chain reaction (sn-MSP) was applied to detect p16 promoter hypermethylation in lung tissues. Additionally, p16 mRNA and protein expression was detected on reverse transcription-polymerase chain reaction (RT-PCR), western blot and the strept actividin-biotin complex method.

RESULTS

Extended exposure to hyperoxia led to increased methylation, and the methylation level reached a peak in the period of maximum pulmonary fibrosis in the hyperoxia group, while the methylation did not occur in the control group. The methylation rates on semi-nested PCR (sn-PCR) and nested-MSP were, respectively, 52.5% and 42.5% in the hyperoxia group. There was no statistically significant difference between the two methods. The p16 mRNA and protein expression was significantly higher in those with p16 promoter hypermethylation than those without.

CONCLUSION

Exposure to hyperoxia may induce p16 promoter hypermethylation in lung tissues in premature rats, and methylation risk increases as exposure extends. p16 promoter methylation induced by hyperoxia may be one of the mechanisms for low p16 mRNA and protein expression.

RhoC expression level is correlated with the clinicopathological characteristics of ovarian cancer and the expression levels of ROCK-I, VEGF, and MMP9

OBJECTIVE

To determine the clinicopathological significance of RhoC expression in human ovarian cancer and its effect on the expression of vascular endothelial growth factor (VEGF), Rho-associated coiled-coil-forming kinase (ROCK), and metal matrix proteinases (MMPs).

METHODS

Tissue samples from normal ovaries, benign ovarian tumors, and epithelial ovarian cancer were collected. The mRNA and protein expression levels of RhoC, ROCK-I, VEGF, and MMP9 were assessed using reverse-transcriptase polymerase chain reaction (RT-PCR) and Western blot, and compared to the clinicopathological characteristics of the sample of origin using the Pearson method of correlation analysis. Small interfering RNA (siRNA) was also used to target RhoC expression in the OVCAR3 and CaOV3 ovarian cancer cell lines, after which cell invasion and migration assays were performed, and the expression of ROCK-I, VEGF, and MMP9 was evaluated.

RESULTS

The expression levels of RhoC, ROCK-I, VEGF, and MMP9 mRNA and protein were significantly higher in ovarian cancer, showing a correlation with clinical stage but not histological type. RhoC expression was positively correlated with ROCK-I, VEGF, and MMP9 expression. Decreased RhoC expression in siRNA-targeted cells inhibited their ability to invade and migrate, as well as inhibiting ROCK-I, VEGF, and MMP9 expression.

CONCLUSION

The expression level of RhoC is correlated to clinical stage and vascularization in ovarian cancer.

[Inhibition of Zoledronic Acid on Cell Proliferation and Invasion of Lung Cancer Cell Line 95D.]

BACKGROUND

Abnormal proliferation and metastasis is the basic characteristic of malignant tumors. The aim of this work is to explore the effects of zoledronic acid on cell proliferation and invasion in lung cancer cell line 95D.

METHODS

The effect of zoledrnic acid (ZOL) on proliferation of lung cancer cell line 95D was detected by MTT. The expression of proliferation and invasion-relation genes and proteins were detected by Western blot, RT-PCR and immunofluorescence. Changes of invasion of lung cancer cell numbers were measured by polycarbonates coated with Matrigel.

RESULTS

ZOL could inhibit the proliferation of lung cancer cell line 95D in vitro in a time-dependant and a dose-dependant manner. With time extending after ZOL treated, the mRNA expresion of VEGF, MMP9, MMP2 and protein expression of VEGF, MMP9, ERK1/ERK2 were decreased. The results of Tanswell invasion showed the numbers of invasive cells were significantly reduced in 95D cells treated with ZOL 4 d and 6 d later.

CONCLUSIONS

ZOL could inhibit cell proliferation and invasion of lung cancer cell line 95D.

Inhibitory effects of c-erbB-2 antisense oligonucleotide transfection on uterine endometrial cancer Ishikawa cell lines

BACKGROUND

C-erbB-2 is a chief proto-oncogene of endometrial cancer, which plays an important role in the biological behavior of endometrial cancer. Its overespression is an important factor of poor progrosis. The objective of this study was to investigate the treatment effects of transfecting c-erbB-2 antisense oligonucleotide (ASODN) on the uterine endometrial cancer Ishikawa cell line.

MATERIALS AND METHODS

The c-erbB-2 expression on Ishikawa cell membranes was determined by immunohistochemistry and then the aim was to transfect ASODN into Ishikawa cells and assay the cellular growth inhibition by MTT, to observe the cellular ultrastructure changes under transmission electron microscope (TEM), and to assay the cellular apoptotic rate, c-erbB-2 mRNA and protein expression by flow cytometry, RT-PCR and Western blot, respectively.

RESULTS

C-erbB-2 protein was positively expressed on Ishikawa cell membranes. MTT showed that when the concentration of transfecting ASODNs was 0.3 uM and 0.6 uM, cell growth inhibition rates were 55.43% and 76.12%, respectively. After transfecting 0.3 uM ASODN, the Ishikawa cell ultrastructure was obviously damaged, the cellular apoptotic rate was 72.21%, and the c-erbB-2 mRNA and protein expression were 45.71% and 34.52%, respectively, compared with those of the normal control cells.

CONCLUSIONS

Transfecting c-erbB-2 ASODN can obviously suppress its mRNA and protein expression in Ishikawa cells, cause cellular apoptosis and inhibit cell growth. It may have an important role in the gene therapy of endometrial cancer.

[PML expression in lung carcinomas: analysis by RT-PCR in formalin-fixed and paraffin-embedded tissue.]

BACKGROUND

Formalin-fixed and paraffin-embedded tissue (FPE) with long term follow-up and clinicopathological data are extensively available and easily accessible. They represent an extensive source of genetic materials and proteins to be investigated for clinical usage. We conducted the study to explore the possibility of extracting RNA from FPE of lung cancer, and checking up the transcription levels of the promyelocytic leukemia gene (PML) by RT-PCR.

METHODS

five fresh frozen lung adenocarcinoma tissues and 40 FPEs of lung cancer were chosen; FPEs had been conserved for 60-85 months. All samples had been identified lacking expression of PML protein by immunohistochemical staining. The total RNA was extracted by using Trizol one-step method, and verified by testing OD value. RT-PCR was used to detect the transcription level of PML gene.

RESULTS

The RNAs from both tissues had the OD value ranging from 1.7 to 2.1. RT-PCR results displayed that mRNA of PML (295 bps) and beta-actin (318 bps) was not absent in all cancer tissues.

CONCLUSIONS

Trizol one-step method is easily accessible, and reliable for extracting RNA in fragments around 300 bases from FPEs. Loss of PML protein in lung cancer is not caused by downward adjustment of mRNA.

CDC25B acts as a potential target of PRKACA in fertilized mouse eggs

Protein kinase A (PRKACA) has been documented as a pivotal regulator in meiosis and mitosis arrest. Although our previous work has established that PRKACA regulates cell cycle progression of mouse fertilized eggs by inhibiting M-phase promoting factor (MPF), little is known about the intermediate factor between PRKACA and MPF in the mitotic cell cycle. In this study, we investigated the role of the PRKACA/CDC25B pathway on the early development of mouse fertilized eggs. Overexpression of unphosphorylatable CDC25B mutant (Cdc25b-S321A or Cdc25b-S229A/S321A) rapidly caused G2-phase eggs to enter mitosis. Microinjection of either Cdc25b-WT or Cdc25b-S229A mRNA also promoted G2/M transition, but much less efficiently than Cdc25b-S321A and Cdc25b-S229A/S321A. Moreover, mouse fertilized eggs overrode the G2 arrest by microinjection of either Cdc25b-S321A or Cdc25b-S229A/S321A mRNA, which efficiently resulted in MPF activation by directly dephosphorylating CDC2A-Tyr15, despite culture under conditions that maintained exogenous dibutyryl cAMP. Using a highly specific antibody against phospho-Ser321 of CDC25B in Western blotting, we showed that CDC25B-Ser321 was phosphorylated at the G1 and S phases, whereas Ser321 was dephosphorylated at the G2 and M phases in vivo. Our findings identify CDC25B as a potential target of PRKACA and show that PRKACA regulates G2/M transition by phosphorylating CDC25B-Ser321 but not CDC25B-Ser229 on the first mitotic division of mouse fertilized eggs.

Musclin Inhibits Insulin Activation of Akt/Protein Kinase B in Rat Skeletal Muscle

Musclin is a muscle-derived secretory peptide that induces insulin resistance in vitro We studied the effect of musclin (0.5 μg/ml) on insulin-stimulated glucose uptake in rat skeletal muscles and also the effect of rosiglitazone (0.4 μg/ml). Pre-incubation of muscles with musclin resulted in decreased insulin-stimulated glucose uptake. Musclin also reduced expression of peroxisome proliferator-activated receptor γ (PPARγ) and liver X receptor α (LXRα) mRNAs, although expression of glucose transporter 4 mRNA was unaltered. Rosiglitazone attenuated the effects of musclin on glucose uptake and PPARγ and LXRα mRNA expression. Western blotting demonstrated that activation of protein kinase B (Akt/PKB) in the insulin-signalling cascade was decreased by musclin but corrected by rosiglitazone. These findings suggest that musclin-induced impairment of insulin-stimulated glucose uptake in skeletal muscle is related to Akt/PKB inhibition and might be modulated by PPARγ/LXRα.

Neuroprotection by sodium ferulate against glutamate-induced apoptosis is mediated by ERK and PI3 kinase pathways

AIM

To investigate whether sodium ferulate (SF) can protect cortical neurons from glutamate-induced neurotoxicity and the mechanisms responsible for this protection.

METHODS

Cultured cortical neurons were incubated with 50 micromol/L glutamate for either 30 min or 24 h, with or without pre-incubation with SF (100, 200, and 500 micromol/L, respectively). LY294002, wortmannin, PD98059, and U0126 were added respectively to the cells 1 h prior to SF treatment. After incubation with glutamate for 24 h, neuronal apoptosis was quantified by scoring the percentage of cells with apoptotic nuclear morphology after Hoechst 33258 staining. After incubation with glutamate for either 30 min or 24 h, cellular extracts were prepared for Western blotting of active caspase-3, poly (ADP-ribose) polymerase (PARP), mu-calpain, Bcl-2, phospho-Akt, phosphorylated ribosomal protein S6 protein kinase (p70S6K), phospho-mitogen-activated protein kinase kinase (MEK1/2) and phosphorylated extracellular signal-regulated kinase (ERK) 1/2.

RESULTS

SF reduced glutamate-evoked apoptotic morphology, active caspase-3 protein expression, and PARP cleavage and inhibited the glutamate-induced upregulation of the mu-calpain protein level. The inhibition of the phosphatidylinositol 3-kinase (PI3K) and the MEK/ERK1/2 pathways partly abrogated the protective effect of SF against glutamate-induced neuronal apoptosis. SF prevented the glutamate-induced decrease in the activity of the PI3K/Akt/p70S6K and the MEK/ERK1/2 pathways. Moreover, incubation of cortical neurons with SF for 30 min inhibited the reduction of the Bcl-2 expression induced by glutamate.

CONCLUSION

The results indicate that PI3K/Akt/p70S6K and the MEK/ERK signaling pathways play important roles in the protective effect of SF against glutamate toxicity in cortical neurons.

Involvement of Protein Kinase B/AKT in Early Development of Mouse Fertilized Eggs1

The activation of AKT (also called protein kinase B) is thought to be a critical step in the phosphoinositide 3-kinase pathway that regulates cell growth and differentiation. In this report, we investigated the role of AKT in the regulation of mouse early embryo development. Injection of mRNA coding for a constitutively active myristoylated AKT (myr-Akt1) into one-cell stage fertilized eggs induced cell division more effectively than injection of wild-type AKT (Akt1-WT) mRNA, whereas microinjection of mRNA of kinase-deficient AKT (Akt1-KD) delayed the first mitotic division. Meanwhile, microinjection of different kinds of mRNA of AKT affected the phosphorylation status of CDC2A-Tyr15 and the activation of M-phase promoting factor (MPF). To investigate the intermediate factor between AKT and MPF, we then injected one-cell stage eggs first with Akt1-WT mRNA or myr-Akt1 mRNA and then with mRNA encoding either wild-type CDC25B (Cdc25b-WT) or a AKT-nonphosphorylatable Ser351 to Ala CDC25B mutant (Cdc25b-S351A). Cdc25b-S351A strongly inhibited the effect of AKT. Therefore, AKT causes the activation of MPF and strongly promotes the development of one-cell stage mouse fertilized eggs by inducing AKT-dependent phosphorylation of CDC25B, a member of the CDC25 phosphatase family. Our finding that CDC25B acts as a potential target of AKT provides new insight into the effect of AKT in the regulation of early development of mouse embryos.

[Transcription expression and clinical significance of CK19 mRNA in pleural fluid of patients with lung cancer]

BACKGROUND

Conventional cytology is valuable in diagnosing the cancer cells in pleural fluid of patients with lung cancer. However, the diagnostic value of detecting pleura micrometastasis is limited. The aim of this study is to investigate clinical significance of CK19 mRNA expression in pleural fluid of patients with lung cancer.

METHODS

Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect CK19 mRNA in pleural fluid from 86 patients with lung cancer and 40 patients with benign lung diseases, and the results were compared with the results of conventional cytologic diagnosis.

RESULTS

The positive rates of CK19 mRNA in pleural fluid were 93.0%(80/86) from patients with lung cancer and 20.0% (8/40) from patients with benign lung diseases, which showed an obvious difference between two groups (Chi-square=65.69, P < 0.01). The positive rates of CK19 mRNA in pleural fluid of patients with lung cancer had no correlation with histopathology types (P > 0.05). The sensitivity and accuracy of CK19 mRNA were obviously higher than those of diagnosis of conventional cytology in pleural fluid of patients with lung cancer (P < 0.01).

CONCLUSIONS

CK19 mRNA can be taken for a molecular marker to detect pleura micrometastasis, it may be helpful to diagnose the cancer cells in pleural fluid of patients with lung cancer and evaluate the clinical staging more correctly.

[Changes of pulmonary artery protein kinase C activity in rats with chronic inflammatory pulmonary hypertension]

OBJECTIVE

To observe the changes in pulmonary artery protein kinase C (PKC) activity in rats with chronic inflammatory pulmonary hypertension (PHT).

METHODS

Chronic inflammatory PHT was induced in rats with monocrotaline. The PKC activities in the rat pulmonary arteries were measured by radioactive assay during the development of PHT.

RESULTS

With the development of chronic inflammatory PHT, the total and cytosolic fractions of PKC activity in PHT rat pulmonary arteries increased initially with subsequent decrease (Plt;0.05), but the membranous fraction of PKC activity and the membrane-to-cytosol PKC activity ratio increased continuously (P<0.05).

CONCLUSION

The up-regulation of PKC activity and the translocation of PKC might be associated with the development of chronic inflammatory PHT in rats.

[Expression of Livin mRNA and protein in human oral squamous cell carcinoma]

PURPOSE

To investigate the expression of the newly found inhibitor of apoptosis protein Livinalpha and Livinbeta and their gene expression in human oral squamous cell carcinoma.

METHODS

Twenty specimens of human squamous cell carcinoma(SCC), 15 cases of benign cysts, 10 cases of normal oral mucosal tissues adjacent to the cancerous lesions were examined. Polymerase chain reaction with reverse transcription (RT-PCR) and Western blot analysed were used to detect mRNA and protein expression of Livin, respectively.The results were analysed by SPSS10.0 software package.

RESULTS

Livin protein and mRNA expression was detected in 19 SCC tissues,14 benign cysts and 10 normal oral mucosal tissues adjacent to the cancerous lesions.But the expressions were significantly higher in oral SCC than in benign cysts and normal oral mucosal tissues (P<0.01).

CONCLUSION

Livin may play an important role in the tumorigenesis and development of human oral squamous cell carcinoma.

[Clinical association of gingipain K-caspase like subdomain expression of Porphyromonas gingivalis with puberty gingivitis]

OBJECTIVE

To detect and compare the activity and intensity of gingipain K (Kgp)-caspase like subdomain in culture medium and cell extract of Porphyromonas gingivalis (Pg) isolates in puberty gingivitis and to reveal the possible association of Kgp with puberty gingivitis.

METHODS

Thirty-six children of 14 to 17 years old were enrolled in this study. Clinical parameters including gingival index (GI), sulcus bleeding index (SBI) and probing depth (PD) were evaluated. Subgingival plaque samples were collected and Pg isolates were obtained. 16S rRNA PCR was used to confirm Pg clinical isolates. Bacteria were grown in batches of BHI base and harvested at the end of log-phase growth. Culture fractions (culture medium and cell extract) of 10 Pg isolates were performed with SDS-PAGE and Western blot technique using primary antibody against specific Kgp-caspase like subdomain. Activity of Kgp in both samples was detected as well. The data were statistically analyzed using SPSS 11.5 software. The relationship between the Kgp intensity/activity of Kgp and the clinical parameters was statistically analyzed using Spearman correlation coefficient.

RESULTS

There was positive correlation between the intensity/activity of Kgp and the clinical parameters (P < 0.05).

CONCLUSIONS

The Kgp in clinical isolates of Pg from puberty gingivitis is in complicated forms. Caspase-like molecules with low molecular weight may exist as intracellular functional protein molecules which can affect the interaction between Pg and host. Kgp was contributes in certain degree to the pathogenesis of puberty gingivitis.

[Effects of Genistein on the proliferation and expression of survivin in salivary adenoid cystic carcinoma cell line SACC-83]

OBJECTIVE

To investigate the anti-proliferation effect of tyrosine protein kinase inhibitor, Genistein, on human salivary adenoid cystic carcinoma cell line SACC-83, and its effect on Survivin expression.

METHODS

SACC-83 cells were treated with different concentration Genistein for different time, cell survival rate was calculated with MTT assay, apoptosis was detected with flow cytometry, the expression of Survivin was quantitatively analyzed by Western blotting and FluorChem V2.0 software.

RESULTS

When treated with Genistein of certain concentration for certain time, SACC-83 cell growth was significantly inhibited. With the increase of concentration and elongation of acting time, the inhibitory effects increase. Treated with 220 micromol/L Genistein for 72 hours, SACC-83 cell growth was significantly inhibited, cell apoptosis was induced (P < 0.01), and the expression of Survivin decreased.

CONCLUSION

Genistein inhibits the growth of human salivary adenoid cystic carcinoma cell line SACC-83, and induces cell apoptosis; the decrease of Survivin expression may be one of the mechanisms of Genistein inducing apoptosis.

Effects of sodium ferulate on amyloid-beta-induced MKK3/MKK6-p38 MAPK-Hsp27 signal pathway and apoptosis in rat hippocampus

AIM

To observe the effects of sodium ferulate (SF) on amyloid beta (Abeta)1-40-induced p38 mitogen-activated protein kinase (MAPK) signal transduction pathway and the neuroprotective effects of SF.

METHODS

Rats were injected intracerebroventricularly with Abeta1-40. Six hours after injection, Western blotting was used to determine the expressions of phosphorylated mitogen-activated protein kinase kinase (MKK) 3/MKK6, phospho-p38 MAPK, interleukin (IL)-1beta, phospho-MAPK activating protein kinase 2 (MAPKAPK-2), the 27 kDa heat shock protein (Hsp27), procaspase-9, -3, and -7 cleavage, and poly (ADP-ribose) polymerase (PARP) cleavage. Seven days after injection, Nissl staining was used to observe the morphological change in hippocampal CA1 regions.

RESULTS

Intracerebroventricular injection of Abeta1-40 induced an increase in phosphorylated MKK3/MKK6 and p38 MAPK expressions in hippocampal tissue. These increases, in combination with enhanced interleukin (IL)-1beta protein expression and reduced phospho-MAPKAPK2 and phospho-Hsp27 expression, mediate the Abeta-induced activation of cell death events as assessed by cleavage of procaspase-9, -3, and -7 and caspase-3 substrate PARP cleavage. Pretreatment with SF (100 mg/kg and 200 mg/kg daily, 3 weeks) significantly prevented Abeta1-40-induced increases in phosphorylated MKK3/MKK6 and p38 MAPK expression. The Abeta1-40-induced increase in IL-1beta protein level was attenuated by pretreatment with SF. In addition, Abeta1-40-induced decreases in phosphorylated MAPKAPK2 and Hsp27 expression were abrogated by administration of SF. In parallel with these findings, Abeta1-40-induced changes in activation of caspase-9, caspase-7, and caspase-3 were inhibited by pretreatment with SF.

CONCLUSION

SF prevents Abeta1-40-induced neurotoxicity through suppression of MKK3/MKK6-p38 MAPK activity and IL-1beta expression and upregulation of phospho-Hsp27 expression.

[Fusion expression and affinity purification of a human novel gene tsbp in eukaryotic cells]

AIM

To construct an eukaryotic expressing vector of the human novel gene testis sperm binding protein (tsbp), and to express fusion protein and purify the recombinant protein by affinity chromatography.

METHODS

The novel gene tsbp was amplified by PCR from the prokaryotic expressing plasmid pGEX-5X-1/tsbp and an eukaryotic expressing vector pcDNA3.1/myc-His(-)B/tsbp was constructed after DNA recombination. After transfecting HEK293 cells with this recombinant vector via liposome mediation, the expression of the fusion protein was detected by RT-PCR, immunofluorescence and Western blot. Fusion protein His6-tsbp was purified from the cell lysis by immobilized metal affinity chromatography (IMAC) and the efficiency of purification was detected by SDS-PAGE and Western blot.

RESULTS

DNA sequencing and restriction endonuclease digestion analysis indicated that the eukaryotic expression vector pcDNA3.1/myc-His(-)B/tsbp had been constructed successfully. After the recombinant plasmid being transfected into HEK293 cells, RT-PCR verified the expression of tsbp mRNA. The result of immunofluorescence assay was positive and the fusion protein could be detected by Western blot of transfected HEK293 cells. The purified fusion protein could also be detected by SDS-PAGE and Western blot.

CONCLUSION

The novel gene tsbp was successfully cloned, expressed and purified in the form of His6 fusion protein, which is helpful for further study of the function of this testis sperm binding protein.

Sodium ferulate prevents amyloid-beta-induced neurotoxicity through suppression of p38 MAPK and upregulation of ERK-1/2 and Akt/protein kinase B in rat hippocampus

AIM

To observe whether an amyloid beta (Abeta)-induced increase in interleukin (IL)-1beta was accompanied by an increase in the p38 mitogen-activated protein kinase (MAPK) pathway and a decrease in the cell survival pathway, and whether sodium ferulate (SF) treatment was effective in preventing these Abeta-induced changes.

METHODS

Rats were injected intracerebroventricularly with Abeta25-35. Seven days after injection, immunohistochemical techniques for glial fibrillary acidic protein (GFAP) were used to determine the astrocyte infiltration and activation in hippocampal CA1 areas. The expression of IL-1beta, extracellular signal-regulated kinase (ERK), p38 MAPK, Akt/protein kinase B (PKB), Fas ligand and caspase-3 were determined by Western blotting. The caspase-3 activity was measured by cleavage of the caspase-3 substrate (Ac-DEVD-pNA). Reverse transcription-polymerase chain reaction was used to analyze the changes in IL-1beta mRNA levels.

RESULTS

Intracerebroventricular injection of Abeta25-35 elicited astrocyte activation and infiltration and caused a strong inflammatory reaction characterized by increased IL-1beta production and elevated levels of IL-1beta mRNA. Increased IL-1beta synthesis was accompanied by increased activation of p38 MAPK and downregulation of phospho-ERK and phospho-Akt/PKB in hippocampal CA regions prepared from Abeta-treated rats, leading to cell death as assessed by activation of caspase-3. SF significantly prevented Abeta-induced increases in IL-1beta and p38 MAPK activation and also Abeta-induced changes in phospho-ERK and phospho-Akt/PKB expression levels.

CONCLUSION

SF prevents Abeta-induced neurotoxicity through suppression of p38 MAPK activation and upregulation of phospho-ERK and phospho-Akt/PKB expression.

Protein kinase A regulates cell cycle progression of mouse fertilized eggs by means of MPF

Cell cycle of one-cell stage mouse fertilized eggs was accompanied by fluctuation in the concentration of adenosine 3'5'-monophosphate (cAMP) and in the activity of free catalytic subunit of cAMP-dependent protein kinase (PKA). The concentration of cAMP and the activity of free catalytic subunit of PKA decreased at the onset of mitosis and increased at the transition between mitosis and G1 phase. Stimulation of PKA by microinjection of cAMP into one-cell stage mouse embryos at G2 phase induced interphase arrest and prevented the activation of M-phase promoting factor (MPF). Upon blockage of the activation of PKA by microinjecting a thermostable PKA inhibitor (PKI) into one-cell stage mouse embryos at G2 phase, the increase in the MPF activity occurred 30 min earlier than in control group. When a high dose of PKI was microinjected, a transition into interphase was prevented, and the activity of MPF remained high. Western blot analysis showed that Cdc2 remained phosphorylated in cAMP microinjected embryos by the time when control embryos were at metaphase and showed dephosphorylated Cdc2; conversely, Cdc2 dephosphorylation was accelerated in PKI-microinjected embryos. At the same time, Cdc2 was phosphorylated at Tyr15 at G2 phase and even at M phase when cAMP was microinjected but was dephosphorylated when PKI was microinjected. PKI microinjection also prevented cyclin B degradation and sustained MPF activity, thus delaying the transition from metaphase to anaphase. Our results show that PKA, by inhibiting MPF, regulates cell cycle progression of fertilized eggs.

[Apoptosis induced by cantharidin in human pulmonary carcinoma cells A549 and its molecular mechanisms]

OBJECTIVE

To investigate the apoptosis-inducing effect of cantharidin in human lung cancer cells A549 and its molecular mechanisms.

METHODS

MTT assay was used to determine A549 cells proliferation. Light and electron microscopy, FACScan, Annexin V-FITC staining and DNA gel electrophoresis were used to detect apoptosis. The expression of bcl-2, Bax and survivin were examined by Western blot.

RESULTS

Cantharidin inhibited the proliferation of A549 cells. The cells treated with cantharidin showed a typical apoptotic morphology and hypodiploid peak before G(1) phase. Flow cytometry analysis with annexin quantitatively further confirmed the increase of cell apoptosis. DNA of treated A549 cells depicted a ladder pattern characteristic of apoptosis, indicating the presence of DNA fragmentation. Western blot assay showed that cantharidin increased the level of Bax expression and inhibited the level of bcl-2 and survivin expression.

CONCLUSION

Cantharidin can induce A549 cells apoptosis mainly via regulation of Bax, bcl-2 and survivin expression.

The inhibitory effect of BSP-A1/-A2 on protein kinase C and tyrosine protein kinase

Bovine seminal plasma contains a group of similar proteins, namely BSP-A1, BSP-A2, BSP-A3, and BSP-30-kDa (collectively called BSP proteins), and they are secreted by the seminal vesicles. In our study, we purified the BSP-A1/-A2 through affinity chromatography and found for the first time that BSP-A1/-A2 can inhibit the activity of protein kinase C (PKC) and tyrosine protein kinase (TPK). The inhibition was dose dependent. When the PKC and TPK activities are expressed as the logarithm of percentage activity taking the activity in the absence of the BSP-A1/-A2 as 100%, there is a linear relationship between the their activities and the dose of BSP-A1/-A2.

[The activity of M-phase promoting factor in oral normal tissue and tumor]

OBJECTIVE

To investigate the content and activity of M-phase promoting factor (MPF) in pleomorphic adenoma, mucoepidermoid carcinoma, buccal carcinoma and normal tissue, in order to evaluate the role of MPF in the development of tumor and the relationship between MPF and malignant degree.

METHODS

The content and activity of MPF were assessed by immunobloting and Gollicano method.

RESULTS

The cdc2 and cyclinB (two subunits of MPF) were found both in normal and tumor tissues, and their content in tumor was higher than normal tissues. Buccal carcinoma was 64% higher than normal tissues. The activity of MPF in carcinoma was higher than normal tissue and had positive relation with the malignant extent.

CONCLUSIONS

The content and activity of MPF in tumor are higher than normal tissue. PKC can activate MPF. These results show PKC may promote tumor proliferation by activating MPF and also, the activity of MPF has some relation with malignant extent.