CUL1 Knockdown Attenuates the Adhesion, Invasion, and Migration of Triple-Negative Breast Cancer Cells via Inhibition of Epithelial-Mesenchymal Transition.

Cullin-1 (CUL1) is an important factor for tumor growth and a potential therapeutic target for breast cancer therapy, but the molecular mechanism in triple-negative breast cancer (TNBC) is unknown. In the present study, CUL1 shRNA was transfected into BT549 and MDA-MB-231 breast cancer cells. Cell morphology, adhesion, invasion, and migration assays were carried out in the CUL1 knockdown cells. Additionally, protein expression levels of epithelial-mesenchymal transition (EMT)-related factors, Akt phosphorylation at S473 (pAkt), glycogen synthase kinase-3ß phosphorylation at ser9 (pGSK3ß), cytoplasmic and nuclear ß-catenin, and epidermal growth factor receptor phosphorylation at Tyr1068 (pEGFR) were detected by Western blot analysis. CUL1 knockdown significantly suppressed the adhesion, invasion and migration capabilities of the cells, and decreased the expression of Snail1/2, ZEB1/2, Twist1/2, Vimentin, and increased the expression of Cytokeratin 18 (CK18). Moreover, CUL1 knockdown significantly downregulated the phosphorylated levels of Akt, GSK3ß, and EGFR, inhibiting the translocation of ß-catenin from the cytoplasm to the nucleus. The results indicate that CUL1 knockdown prohibited the metastasis behaviors of breast cancer cells through downregulation (dephosphorylation) of the EMT signaling pathways of EGFR and Akt/GSK3ß/ß-catenin in breast cancer. These results strongly suggested that reinforcement of the EMT might be a key for CUL1 to accelerate TNBC metastasis.

Changes of serum lipopolysaccharide, inflammatory factors, and cecal microbiota in obese rats with type 2 diabetes induced by Roux-en-Y gastric bypass.

OBJECTIVES: Previous studies have shown that Roux-en-Y gastric bypass (RYGB) leads to rapid regression of obesity and type 2 diabetes (T2D). However, the underlying mechanism remains unclear. This study aimed to investigate the effect of RYGB on serum lipopolysaccharide (LPS), interleukin (IL)-1, IL-6, tumor necrosis factor alpha (TNF-α), and cecal microbiota in obese rats with T2D. METHODS: Obese Sprague-Dawley rats with T2D were randomly divided into RYGB diabetes operation (DO; n = 8), diabetes sham operation (DS; n = 8), and diabetic control (DC; n = 8) groups. Healthy Sprague-Dawley rats were grouped as normal control (NC; n = 8). Fasting plasma glucose and body weight were measured. The levels of peripheral serum LPS, IL-1, IL-6, and TNF-α were measured by enzyme-linked immunosorbent assay. The rats were sacrificed 12 wk after operation. Subsequently, a superior mesenteric venous blood sample was taken to measure serum LPS levels by enzyme-linked immunosorbent assay. The cecal contents of the DO and DS groups were taken to extract metagenomic DNA per the genomic DNA standardization procedure. The V4 region of the 16 S rRNA was sequenced with the Illumina Hiseq sequencing platform to compare the structure and relative abundance of cecal microbiota between the DO and DS groups. RESULTS: Twelve weeks after operation in the DO group, fasting plasma glucose and body weight showed a significant decrease (P < 0.05). Moreover, the levels of peripheral serum LPS, IL-1, IL-6, and TNF-α were obviously decreased (P < 0.05). A change in the LPS level of superior mesenteric venous blood also revealed a dramatic decrease (P < 0.05). Additionally, RYGB resulted in a shift of cecal microbiota in obese rats with T2D. CONCLUSIONS: Hypoglycemic effects after RYGB may be associated with improved levels of LPS, IL-1, IL-6, and TNF-α. Changes in the structure of cecal microbiota may also play an important role.

Protective effects of silibinin and its possible mechanism of action in mice exposed to chronic unpredictable mild stress.

Silibinin, a natural flavonoid antioxidant isolated from extracts of the milk thistle herb, has recently been identified as having anti-hepatotoxic and anticancer properties. In this paper, we investigated the effects of silibinin on behavior and neuroplasticity in mice subjected to chronic unpredictable mild stress (CUMS). After 5 consecutive weeks of CUMS, the mice were treated with silibinin (100 mg/kg, 200 mg/kg and 400 mg/kg by oral gavage) for 3 consecutive weeks. The results showed that silibinin administration significantly alleviated the CUMS-induced depressive-like behavior, including the total number of squares crossed and the frequency of rearing in the open field test, the immobility time in the tail suspension test and the forced swimming test. Furthermore, silibinin treatment increased the levels of brain-derived neurotrophic factor (BDNF), serotonin (5-HT) and norepinephrine (NE) in the prefrontal cortex and hippocampus. Our study provides new insight into the protective effects of silibinin on the depressive status of CUMS mice, specifically by improving neuroplasticity and neurotransmission.

Duodenal-jejunal exclusion improves insulin resistance in type 2 diabetic rats by upregulating the hepatic insulin signaling pathway.

OBJECTIVES: Previous studies have shown duodenal-jejunal exclusion (DJE) results in the rapid resolution of type 2 diabetes; however, the underlying mechanism is unknown. This study aimed to measure the hepatic expression of insulin receptor substrate-2 (IRS-2) and glucose transporter-2 (GLUT-2) in type 2 diabetic rats post-DJE, and to investigate their roles in improved hepatic insulin resistance and glucose intolerance. METHODS: Type 2 diabetic Sprague-Dawley (SD) rats were randomly divided into DJE operation (DO) and control (DC) groups. Normal SD rats were also divided into DJE operation and control groups. Fasting plasma glucose and insulin concentrations were measured, and the quantitative insulin sensitivity check index (QUICKI) and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) were calculated. Eight weeks postoperation, the hepatic IRS-2 and GLUT-2 protein and mRNA levels were measured using western blotting and reverse transcription polymerase chain reaction, respectively. RESULTS: The fasting blood glucose in the DO group decreased from a preoperative level of 20.21 ± 2.14 mmol/L to 8.50 ± 2.19 mmol/L (P < 0.05) 8 wk post-DJE. A change in the QUICKI revealed a dramatic increase, and HOMA-IR showed a significant decrease in the DO group (P < 0.05). Additionally, the IRS-2 and GLUT-2 protein and mRNA levels at 8 wk postoperation were significantly increased in the DO group compared with the DC group. CONCLUSIONS: DJE led to upregulated hepatic IRS-2 and GLUT-2 expression in the hepatic insulin signaling pathway and improved insulin sensitivity in type 2 diabetic rats.