SEMA4D Knockdown Attenuates ß-Catenin-Dependent Tumor Progression in Colorectal Cancer.

Semaphorin 4D (SEMA4D), a protein originally demonstrated to regulate the immune system and axonal growth cone collapse in the developing central nervous system, is overexpressed in various human malignancies, including colorectal cancer (CRC). This investigation was undertaken to examine the effects of SEMA4D silencing on the biological properties of the CRC cell line. SW48 cells were transfected with a siRNA-targeting SEMA4D. The mRNA expression of underlying pro- and antiapoptotic proteins including Bax, Bcl-2, P53, and caspase-3, cancer stem cell (CSC) markers, epithelial-mesenchymal transition (EMT) markers, MMP-2, and MMP-9 was examined using qRT-PCR. Further, the protein expression of E-cadherin and ß-catenin was confirmed by Western blot. SW48 cell migration and MMP activity were detected using scratch and zymography analysis, respectively. Finally, the apoptosis rate was assessed via the flowcytometry test. SEMA4D knock-down was associated with a considerable suppression of in vitro cell viability, EMT-related genes, CSC markers, ß-catenin signaling pathway, sphere-forming, cell migration, and MMP-2 activity as well as induction of apoptosis. This study identifies the inhibitory effects of SEMA4D gene silencing on tumor progression. Thereby, this might conclude a possible alternative to cancer therapy by targeting several prominent pathways involved in cancer through SEMA4D suppression.

Inhibition of semaphorin 4D enhances chemosensitivity by increasing 5-fluorouracile-induced apoptosis in colorectal cancer cells.

Overexpression of semaphorin 4D (SEMA4D), an immune semaphorin, is found in various human malignancies, including colorectal cancer (CRC). In this study, we explored the relationship between silencing SEMA4D expression and 5-fluorouracil (5-FU) response in the colorectal cancer cell line. SW48 cells were transfected with a short interfering RNA (siRNA) in order to silence SEMA4D gene expression and then exposed to 5-FU for 48 h. The down-regulation of SEMA4D expression was confirmed by qRT-PCR and the particular concentration of 5-FU was acquired using MTT assay. Flow cytometry and western blot were used to evaluate apoptosis rate and pro- and anti-apoptotic expression levels of proteins involved in apoptosis including Bax, Bcl-2, P53, and caspase-3. Other oncogenic activities including epithelial-mesenchymal transition (EMT) process, cancer stem cell (CSC) markers, and ß-catenin pathway were investigated using qRT-PCR, and western blot. The proliferation was analyzed via colony formation test and cell invasion was assessed by transwell assay. Our data demonstrate that SEMA4D silencing results in strikingly elevated apoptosis in response to 5-FU treatment and leads to down-regulation of Bcl-2 and overexpression of Bax, P53, and caspase-3 in protein levels. Furthermore, the mRNA and protein expression levels of ß-catenin, as well as transcript expressions of CSCs and EMT markers, were remarkably diminished. However, mRNA expression of E-cadherin as an epithelial marker was significantly increased in 5-FU treatment combined with siRNA SEMA4D. This study implicates that the silencing of SEMA4D by siRNA promotes the chemosensitivity of SW48 cells to 5-FU and it may be a potential therapeutic agent for colon cancer therapy.

Direct correlation between Th1 and Th17 responses in immunity to Brucella infection.

Th1 cells play a central role in immunity to brucellosis, while the exact role of Th17 cells has remained unknown. This study aimed to evaluate the peripheral distributions of Th1 and Th17 cells and serum levels of IFN-γ, IL-17A and IL-22 cytokines in brucellosis patients. One hundred patients (36 acute, 41 under-treatment and 23 relapsed) and 30 age- and sex-matched healthy controls were included. The frequencies of Th1 and Th17 cells were determined by flow cytometric analysis. Serum levels of IFN-γ, IL-17A and IL-22 were measured by multi-analyte flow assay. Increased frequencies of Th1 and Th17 cells were observed in acute and relapsed brucellosis versus under-treatment patients and healthy controls (P < 0.05). The mean serum levels of IFN-γ were significantly elevated in acute and relapsed groups compared to under-treatment patients (P = 0.002 and P = 0.01 respectively). Acute patients showed higher levels of IL-22 than under-treatment (P = 0.008). Direct correlations were found between increased frequencies of Th1 and Th17 cells in acute and relapsed patients (P = 0.007 and P = 0.001 respectively) and between IL-17A and IL-22 in both groups of patients. Our findings indicate a cooperative role for Th1 and Th17 cells in immunity to brucellosis which is more evident during acute and relapse phases of brucellosis.

STAT3 and apoptosis challenges in cancer.

Several studies have processed conceivable evidence for the vital role of Signal Transducer and Activator of Transcription 3 (STAT3) in cancer transformation and carcinogenesis. Therefore, one of the important factors in formation of cancer is STAT3 and for design of novel anticancer drugs is a suitable target. On the other hand, apoptosis pathway has a critical role in the cancers pathogenesis. Generally, increasing developments have been existed to expression, production, phosphorylation or activation of STAT3 in the effective or responsible cells of most of the cancers. In return, apoptosis process in this cells have been suffered inhibition, decrease in expression, produce or activation in some related factors which lead to debilitation or inhibition of the process. Further understanding of the STAT3 related signaling and apoptosis pathway can lead to the invention of novel approaches for therapies in unstudied disease. In this manuscript, review and highlight recent knowledge of the STAT3 pathway and its connection with apoptosis process in cancers and discuss STAT3-targeting agents to therapeutic developments.