Notch signalling pathway in development of cholangiocarcinoma

Cholangiocarcinoma(CCA)comprises of extra-hepatic cholangiocarcinoma and intrahepatic cholangiocarcinoma cancers as a result of inflammation of epithelium cell lining of the bile duct.The incidence rate is increasing dramatically worldwide with highest rates in Eastern and South Asian regions.Major risk factors involve chronic damage and inflammation of bile duct epithelium from primary sclerosing cholangitis,chronic hepatitis virus infection,gallstones and liver fluke infection.Various genetic variants have also been identified and as CCA develops on the background of biliary inflammation,diverse range of molecular mechanisms are involved in its progression.Among these,the Notch signalling pathway acts as a major driver of cholangiocarcinogenesis and its components(receptors,ligands and downstream signalling molecules)represent a promising therapeutic targets.Gamma-Secretase Inhibitors have been recognized in inhibiting the Notch pathway efficiently.A comprehensive knowledge of the molecular pathways activated by the Notch signalling cascade as well as its functional crosstalk with other signalling pathways provide better approach in developing innovative therapies against CCA.

Inhibition of neurite outgrowth using commercial myelin associated glycoprotein-Fc in neuro-2a cells

Myelin-associated glycoprotein（MAG） inhibits the growth of neurites from nerve cells. Extraction and purification of MAG require complex operations; therefore, we attempted to determine whether commercially available MAG-Fc can replace endogenous MAG for research purposes. Immunofluorescence using specific antibodies against MAG, Nogo receptor（NgR） and paired immunoglobulin-like receptor B（PirB） was used to determine whether MAG-Fc can be endocytosed by neuro-2a cells. In addition, neurite outgrowth of neuro-2a cells treated with different doses of MAG-Fc was evaluated. Enzyme linked immunosorbent assays were used to measure RhoA activity. Western blot assays were conducted to assess Rho-associated protein kinase（ROCK） phosphorylation. Neuro-2a cells expressed NgR and PirB, and MAG-Fc could be endocytosed by binding to NgR and PirB. This activated intracellular signaling pathways to increase RhoA activity and ROCK phosphorylation, ultimately inhibiting neurite outgrowth. These findings not only verify that MAG-Fc can inhibit the growth of neural neurites by activating RhoA signaling pathways, similarly to endogenous MAG, but also clearly demonstrate that commercial MAG-Fc is suitable for experimental studies of neurite outgrowth.

Discoidin domain receptor 1 as a potent therapeutic target in solid tumors

Despite significant discoveries in basic cancer research and improvements in treatment options and clinical outcomes,cancer remains a major public health concern worldwide.Today,the main focus of cancer research is the signaling pathways that are crucial for cell survival,cell proliferation,and cell migration.The aberrant expression of proteins involved in these signaling pathways often leads to abnormal cell growth,cell metastasis,and invasion of healthy tis-sues.One such protein is discoidin domain receptor 1(DDR1)which belongs to the family of receptor tyrosine kinases(RTKs)and is activated upon collagen binding,as a result,downstream signaling pathways are stimulated which are responsible for cell survival,cell growth,adhesion,extracellular matrix remodeling,and cell migration.DDR1 is found to have abnormally elevated expression in various solid tumors,implying a critical role in cancer progression.Tradi-tional cancer treatment involves the use of cytotoxic drugs,chemotherapy,radiotherapy,and surgery,which do not pro-vide long-term survival and often result in cancer recurrence.Numerous small-molecule kinase inhibitors have been synthesized against RTKs including DDR1 and have been highly efficacious in tumor reduction.More recently,targeting the DDR1 extracellular domain(ECD)has garnered much attention from researchers,as inhibiting the DDR1-collagen binding has been attributed to maximizing the likelihood of the combined cytotoxic effect of both immune cells and tar-geted drugs.This review focuses on the structure,function,activation,and signaling partners of DDR1,its role in different solid tumors,andfinally discusses about designing more DDR1 non-kinase inhibitors as promising therapeutic strategies against DDR1-driven tumors.

TOSO interacts with SYK and enhances BCR pathway activation in chronic lymphocytic leukemia

Background:TOSO,also named Fas inhibitory molecule 3(FAIM3),has recently been identified as an immunoglobulin M(IgM)Fc receptor(FcμR).Previous studies have shown that TOSO is specifically over-expressed in chronic lymphocytic leukemia(CLL).However,the functions of TOSO in CLL remain unknown.The B-cell receptor(BCR)signaling pathway has been reported to be constitutively activated in CLL.Here,we aimed to investigate the functions of TOSO in the BCR signaling pathway and the pathogenesis of CLL.Methods:We over-expressed TOSO in B-cell lymphoma cell lines(Granta-519 and Z138)by lentiviral transduction and knocked down TOSO by siRNA in primary CLL cells.The over-expression and knockdown of TOSO were confirmed at the RNA level by polymerase chain reaction and protein level by Western blotting.Co-immunoprecipitation with TOSO antibody followed by liquid chromatography coupled with tandem mass spectrometry(IP/LCMS)was used to identify TOSO interacting proteins.Western blotting was performed to detect the activation status of BCR signaling pathways as well as B-cell lymphoma 2(BCL-2).Flow cytometry was used to examine the apoptosis of TOSO-over-expressing B lymphoma cell lines and TOSO-down-regulated CLL cells via the staining of Annexin V and 7-AAD.One-way analyses of variance were used for intergroup comparisons,while independent samples t tests were used for two-sample comparisons.Results:From IP/LCMS,we identified spleen tyrosine kinase(SYK)as a crucial candidate of TOSO-interacting protein and confirmed it by co-immunoprecipitation.After stimulation with anti-IgM,TOSO over-expression increased the phosphorylation of SYK,and subsequently activated the BCR signaling pathway,which could be reversed by a SYK inhibitor.TOSO knockdown in primary CLL cells resulted in reduced SYK phosphorylation as well as attenuated BCR signaling pathway.The apoptosis rates of the Granta-519 and Z138 cells expressing TOSO were(8.46±2.90)%and(4.20±1.21)%,respectively,significantly lower than the rates of the control groups,which were(25.20±4.60)%and(19.72±1.10)%,respectively(P<0.05 for both).The apoptosis rate was reduced after knocking down TOSO in the primary CLL cells.In addition,we also found that TOSO down-regulation in primary cells from CLL patients led to decreased expression of BCL-2 as well as lower apoptosis,and vice versa in the cell line.Conclusions:TOSO might be involved in the pathogenesis of CLL by interacting with SYK,enhancing the BCR signaling pathway,and inducing apoptosis resistance.