ABSTRACT
Fragile X syndrome (FXS) is a leading genetic cause of autism intellectual disorder and autism spectrum disorder (ASD), with either limited treatment options or incurable. Fragile X-related gene 1 (FXR1) is a homolog of the Fragile X mental retardation gene 1 (FMR1), the causative gene of FXS, and both are highly homologous and functionally identical. In FXS, both PI3K (AKT/mTOR signaling pathway) and ERK1/2 (MAPK signaling pathway) expression levels were abnormal. Dual speci?city phosphatase 6 (DUSP6) is a member of the mitogen-activated protein kinases (MAPKs) that participates in the crosstalk between the two signaling systems of MEK/ERK and mTOR. By interacting with multiple nodes of MAPK and PI3K/AKT signaling pathways (including the mTOR complex), DUSP6 regulates cellular growth, proliferation, metabolism and participates in pathological processes of cancer and cognitive impairment. However, whether there is an interaction between FXR1P and DUSP6 and the effects of DUSP6 on the growth of SK-N-SH cells remains elusive. As demonstrated by our results, FXR1P was identified in the cytoplasm and nucleus of SK-N-SH cells co-localized with DUSP6, which might have regulated ERK1/2 signaling pathways in SK-N-SH cells. To a certain extent, FXR1P may reverse the negative regulation of ERK1/2 by DUSP6. Moreover, we discovered that not only does DUSP6 inhibit proliferation, but it also promotes the apoptosis of SK-N-SH cells.
ABSTRACT
@#[Abstract] Objective: To establish paclitaxel(PTX)-resistant human triple negative breast cancer cell line and to examine the expression profile of FA-related genes and FANCF, the correlation between the expression of FA-related genes, FANCF and PTX-resistance in breast cancer were further analyzed. Methods: PTX-resistant MDA-MB-231 cell line was established by means of long-term PTX-exposed culture. The sensitivity of the cells to paclitaxel was determined by the CCK8 assay. The cell cycle distribution was examined by flow cytometry after exposure to the paclitaxel. The expression of FA-related gene mRNA and FANCF protein were examined by using real time quantitative PCR and Western blotting. The expression of FANCF in the cells was reduced by RNAi interference technology and the effect of the RNAi was verified. Results: MDA-MB-231/PTX cell showed a 9.9-fold resistance to paclitaxel, indicating that the cell had acquired resistance to PTX. PTX treatment significantly induced G0/G1 arrest and the number of cells in phase S markedly decreased after exposure to PTX. The mRNA and protein expression of FANCF was significantly higher in PTX-resistant cell than that in PTX-sensitve parental cell，Knockdown of FANCF induced apoptosis in MDA-MB-231/PTX cell as well as in parental cell. FANCF knockdown increased the sensitivity of paclitaxel to both MDA-MB-231 and MDA-MB-231/PTX cells (P<0.05 or P<0.01). Conclusion: FANCF played an important role in PTX resistance of the breast cancer cells and FANCF might be a target for therapy aimed at reversing chemoresistance.
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@# Objective: To investigate the expression profile and function of FANCF gene (a key gene in FA/BRCA pathway) in both cisplatin (DDP)-resistant and DDP-sensitive human triple-negative breast cancer cell lines and to analyze its correlation with DDP-resistance in breast cancer. Methods: The DDP-resistant breast cancer MDA-MB-231 cell line (MDA-MB-231/DDP) was established by induction of gradient DDP. The expression of FANCF gene in both sensitive and resistant cell lines was knocked-down by RNAi interference technology and the knockdown efficiency was validated at both RNA and protein level. The cell viability of MDA-MB-231 cells and MDA-MB-231/DDP cells was determined by the CCK8 assay; Flow cytometry was used to examine the cell cycle distribution and apoptosis; the mRNAand protein expressions of FANCF gene were examined by using qRT-PCR and western blotting, respectively. Results: The resistance index of MDA-MB-231/DDP cells was 13.5 after 3-month induction. The mRNA and protein expressions of FANCF were significantly increased in MDA-MB-231/DDP cells (all P<0.01). Cell cycle analysis indicated that the DDP treatment significantly induced G0/G1 arrest and decreased the cell proportion in phase S and G2/M. siRNA-mediated knockdown of FANCF could not only be able to increase sensitivity of MDA-MB-231 to DDP but also promote the cell apoptosis (all P<0.01). Conclusion: FANCF attributes to the occurrence of DDP-resistance through anti-apoptosis effect, which might be served as a potential treatment target for drug-resistant human breast cancer.
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AIM@#To study the effects of crebanine on voltage-gated Na(+) channels in cardiac tissues.@*METHODS@#Single ventricular myocytes were enzymatically dissociated from adult guinea-pig heart. Voltage-dependent Na(+) current was recorded using the whole cell voltage-clamp technique.@*RESULTS@#Crebanine reversibly inhibited Na(+) current with an IC50 value of 0.283 mmol·L(-1) (95% confidence range: 0.248-0.318 mmol·L(-1)). Crebanine at 0.262 mmol·L(-1) caused a negative shift (about 12 mV) in the voltage-dependence of steady-state inactivation of Na(+) current, and retarded its recovery from inactivation, but did not affect its activation curve.@*CONCLUSION@#In addition to blocking other voltage-gated ion channels, crebanine blocked Na(+) channels in guinea-pig ventricular myocytes. Crebanine acted as an inactivation stabilizer of Na(+) channels in cardiac tissues.
Subject(s)
Animals , Female , Male , Aporphines , Pharmacology , Cells, Cultured , Down-Regulation , Drugs, Chinese Herbal , Pharmacology , Guinea Pigs , Heart Ventricles , Cell Biology , Metabolism , Myocytes, Cardiac , Metabolism , Stephania , Chemistry , Voltage-Gated Sodium Channel Blockers , Pharmacology , Voltage-Gated Sodium Channels , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To study a feasible method of measuring right ventricular pressure by catheterization in mice.</p><p><b>METHODS</b>Measuring the right ventricular pressure and the pulmonary artery pressure by homemade PE pipe through venous cannula in external jugular vein, using catheterization in mice with powerlab multimodal biometric signal recording system.</p><p><b>RESULTS</b>Forty-six out of 51 mice were experimented with this method smoothly and got a total success rate of 90.2%. Thirty of 33 normal mice and 16 of 18 mice with pulmonary arterial hypertension (PAH) were catheterized successfully. The right ventricular pressure were as follow: systolic blood pressure: (23.4 +/- 5.7) mmHg in normal group vs (32.2 +/- 2.8) mmHg in mice with PAH, diastolic blood pressure: (3.7 +/- 2.6) mmHg vs (3.8 +/- 2.0) mmHg, mean pressure: (12.0 +/- 3.7) mmHg vs (14.9 +/- 2.3) mmHg. After autopsy for those 5 failed cases, we found that 2 cases were into the inferior vena cava, another 2 cases pierced the right auricle and the last one punctured the axillary vein into the chest wall.</p><p><b>CONCLUSION</b>Measuring the right ventricular pressure through venous cannula in external jugular vein with homemade PE pipe in mice gets not only a high success rate but also help to save time. Moreover, this method can be popularized easily. It is a good and feasible method for measuring right ventricular pressure in mice.</p>