SOX11-dependent CATSPER1 expression controls colon cancer cell growth through regulation the PI3K/AKT signaling pathway.

BACKGROUND: Colorectal cancer (CRC) is one of the most common malignant tumors and the fourth leading cause of cancer death worldwide. Constitutive activation of the PI3K/AKT signaling pathway is a hallmark of colon tumor growth. CATSPER1 gene encodes a pore-forming and pH-sensing subunit of the CatSper Ca2+-permeable channel, a sperm-specific calcium channel essential for hyperactivated motility and male fertility. However, the function of CATSPER1 outside the male reproductive system is unclear. OBJECTIVE: This study was designed to explore whether CatSper exerted its functional role in the progress of CRC, and investigate the possible mechanisms. METHODS: Microarray data (GSE146587) from 6 patients diagnosed with stage III CRC post-surgery was analyzed by Limma R package. The Kaplan Meier plotter (KM plotter) database was used to assess the relevance of CATSPER1 mRNA expression to the overall survival (OS) rates in CRC. Western blot, real-time PCR and luciferase reporter assays were used to determine the SOX11-CATSPER1 axis in CRC cells. Clustered regularly interspaced short palindromic repeats (CRISPR)-based gene editing was used to generate CATSPER1 knockout (KO) CRC cells. The proliferation of CRC cells was determined by BrdU incorporation and colony formation assays. The effect of CATSPER1 on CRC tumor growth in vivo was investigated in a mice tumor xenograft model. RESULTS: Here, we show that CATSPER1 expression was significantly up-regulated in CRC and elevated CATSPER1 was associated with poor overall survival (OS). Moreover, the transcription factor SOX11 (SRY-related high-mobility-group (HMG) box 11) activated CATSPER1 transcription in CRC cells. Functionally, we showed that CATSPER1 promoted CRC cells proliferation both in vitro and in vivo. At the molecular level, we demonstrated that CATSPER1 might maintain CRC malignant process partly through the activation of the PI3K/AKT signaling pathway. CONCLUSION: Increased CATSPER1 expression facilitates CRC cells proliferation, suggesting that targeting CATSPER1 might represent a promising strategy for colon cancer treatment.

Dexmedetomidine alleviated lipopolysaccharide/D-galactosamine-induced acute liver injury in mice.

Dexmedetomidine (DEX), a highly selective α2-adrenergic receptor (α2-AR) agonist, is widely used as sedative in clinical. Its potential anti-inflammatory properties have been found in recent studies. The current study has investigated the profound effects of DEX on acute liver injury in mice. The mice were intraperitoneally injected lipopolysaccharide (LPS) and D-galactosamine (D-Gal) to induce acute liver injury, and vehicle or DEX were treated 30 min before or 2 h after LPS/D-Gal exposure. The results showed that pre-treatment with DEX inhibited the raising of plasma aminotransferases, reduced the damage of liver tissue, and improved the survival rate in mice exposed to LPS/D-Gal. Pre-treatment with DEX also inhibited the release of TNF-α and suppressed the phosphorylation of c-jun-N-terminal kinase (JNK) in mice exposed to LPS/D-Gal. In addition, pre-treatment with DEX down-regulated the expression of cleavage of caspase-3, decreased the activities of caspase-3, caspase-8, caspase-9, and consequently, reduced hepatocyte apoptosis. Interestingly, post-treatment with DEX also resulted in beneficial outcomes. The current study indicates that administration of DEX might provide protective benefits in inflammatory liver disease.

Metformin suppresses intrahepatic coagulation activation in mice with lipopolysaccharide/D­galactosamine­induced fulminant hepatitis.

Metformin is a widely­used antidiabetic drug with hypoglycemic activity and previously described anti­inflammatory properties. Previous studies have demonstrated that metformin attenuates endotoxic hepatitis, however the mechanisms remain unclear. Inflammation and coagulation are closely associated pathological processes, therefore the potential effects of metformin on key steps in activation of the coagulation system were further investigated in endotoxic hepatitis induced by lipopolysaccharide/D­galactosamine (LPS/D­Gal). The current study demonstrated that treatment with metformin significantly suppressed the upregulation of tissue factor and plasminogen activator inhibitor­1 in LPS/D­Gal­exposed mice. In addition, a reduction in the expression of interleukin 6 and inhibition of nuclear translocation of nuclear factor­κB were observed. These data indicate that the LPS/D­Gal­induced elevation of the stable protein level of hypoxia inducible factor 1α, the mRNA level of erythropoietin, vascular endothelial growth factor and matrix metalloproteinase­3, and the hepatic level of lactic acid were also suppressed by metformin. The current study indicates that the suppressive effects of metformin on inflammation­induced coagulation may be an additional mechanism underlying the hepatoprotective effects of metformin in mice with LPS/D­Gal­induced fulminant hepatitis.

Hypoxia-inducible factor 1 regulated ARC expression mediated hypoxia induced inactivation of the intrinsic death pathway in p53 deficient human colon cancer cells.

Apoptosis repressor with caspase recruitment domain (ARC), an anti-apoptotic protein, plays an important role in the regulation of apoptosis by blocking both the extrinsic and intrinsic death pathways. However, its regulatory mechanism remains largely undefined. Here, we reported that hypoxia up-regulated the expression of ARC in p53 deficient human colon cancer cells. Moreover, ARC is a direct target of the hypoxia-inducible factor 1 (HIF-1), a key transcriptional factor for the cellular response to hypoxia. Silencing the expression of HIF-1α in SW480 colon cancer cells by RNA interference abolished hypoxia induced ARC expression. Using luciferase reporter and ChIP assay, we showed that HIF-1α directly bound to hypoxia-responsive element located at -419 to -414 of ARC gene, which is essential for HIF-1-induced expression. As a result of the increased ARC expression, TRAIL-induced apoptosis was reduced by hypoxia. These discoveries would shed novel insights on the mechanisms for ARC expression regulation and hypoxia induced inactivation of the intrinsic death pathway.

ELISA test to detect CDKN2A (p16(INK4a)) expression in exfoliative cells: a new screening tool for cervical cancer.

BACKGROUND: The purpose of this study was to use an enzyme-linked immunosorbent assay (ELISA) to detect cyclin-dependent kinase inhibitor 2A (CDKN2A; also known as p16(INK4a)) in exfoliative cervical cells. CDKN2A is upregulated and considered as a surrogate marker for cervical intraepithelial neoplasia and cancer. METHODS: Liquid-based ThinPrep((R)) cytologic test (TCT) and ELISA were performed on 1356 specimens collected prior to biopsy. A cotton swab was used to gather exfoliative cells. A sandwich ELISA was performed to measure the amount of solublized CDKN2A protein. RESULTS: The sensitivity and specificity of the TCT for screening of cervical dysplasia and cancer were 82.93% and 88.11%, respectively. The sensitivity and specificity for measuring CDKN2A with ELISA to detect significant cervical disease were 87.80% and 92.43%, respectively. CDKN2A expression was correlated with the severity of cervical damage (r = 0.774; p < 0.001). CONCLUSION: The sensitivity and specificity of detecting CDKN2A expression with ELISA in exfoliative cervical cells was superior to TCT (p = 0.023 and p < 0.001, respectively). These results suggest that detecting CDKN2A with ELISA has the potential to become a new screening method for cervical cancer.