Erbin interacts with Sema4C and inhibits Sema4C-induced epithelial-mesenchymal transition in HK2 cells

Sema4C modulates the migration of primary tumor-associated lymphatic endothelial cells via an ERK-mediated pathway

Although lymphatic endothelial cells (LECs) serve a positive role in tumor lymphatic metastasis, the regulation of LECs undergoing migration similar to that of tumor cells remains poorly understood. A previous study revealed that semaphorin 4C (Sema4C) could be a marker of LECs in cervical cancer. Thus, the present study aimed to understand the mechanism via which Sema4C could promote the development of tumor-associated characteristics in LECs in cervical cancer. Primary tumor-associated LECs (TLECs) were distinguished from cervical cancer by flow cytometry. The promigratory ability was assessed using the Transwell assay. Lentivirus infection was used to alter the expression of Sema4C in TLECs. Confocal laser scanning was used to determine the infection efficiency of lentivirus infection. Sema4C/ERK/E-cadherin pathway was measured by reverse transcription-quantitative PCR and western blotting. The co-localization of Sema4C and the lymphatic marker lymphatic vessel endothelial hyaluronan receptor 1 was verified. Primary tumor-associated LECs (TLECs) were isolated from a mouse xenograft cervical tumor model. It was revealed that overexpressing Sema4C stimulated the migratory ability of TLECs, downregulated E-cadherin expression and stimulated ERK phosphorylation, whereas knocking down Sema4C had the opposite effects. The treatment of PD98059 (ERK inhibitor) blocked the pro-migratory ability of TLECs, which indicated a dependence on the ERK signaling pathway. It was identified that the Sema4C/ERK/E-cadherin pathway may be critical for the migration of TLECs, which may promote lymph node metastasis. Therefore, Sema4C could be a promising target for the treatment of cervical cancer with lymphatic metastasis.

Long non-coding RNA TDRG1 promotes hypoxia-induced glycolysis by targeting the miR-214-5p/SEMA4C axis in cervical cancer cells

Long non-coding RNA (lncRNA) has been demonstrated as vital regulator in human cancer. However, the precise role of lnc-TDRG1 in cervical cancer (CC) remains unclear, so this study was aimed to clarify the role and underlying molecular mechanism of lnc-TDRG1 in CC. The real-time quantitative polymerase chain reaction (RT-qPCR) was conducted to assess the expression levels of lnc-TDRG1, miR-214-5p and Semaphorin 4C (SEMA4C). Under hypoxia condition, the biological behaviors of CC cell, including invasion and glycolysis were determined by transwell assay and Glucose Assay Kit and Lactate Assay Kit, respectively. The Western blot assay was employed to test the expression level of SEMA4C and hexokinase 2 (HK2) expression. The interaction relationship between miR-214-5p and lnc-TDRG1 or SEMA4C was analyzed bioinformatics database and confirmed by dual-luciferase reporter assay, respectively. A xenograft experiment in nude mice was established to clarify the functional role of lnc-TDRG1 in vivo. We found Lnc-TDRG1 was highly expressed in CC tissues and cells and it was upregulated in response to hypoxia. Loss-of-functional experiment suggested that knockdown of lnc-TDRG1 impede invasion, hypoxia-induced glycolysis in vitro and tumor growth in vivo, which was abolished by knockdown of miR-214-5p or overexpression of SEMA4C. Moreover, we confirmed that miR-214-5p specifically bound to SEMA4C and negatively correlated with SEMA4C expression. Collectively, lnc-TDRG1 regulated SEMA4C expression by sponging miR-214-5p in CC. Collectively, mechanistically, lnc-TDRG1 could act as a sponge of miR-214-5p to regulate the expression of SEMA4C, and further regulate invasion and hypoxia-glycolysis in CC cells.

Downregulation of SEMA4C Inhibit Epithelial-Mesenchymal Transition (EMT) and the Invasion and Metastasis of Cervical Cancer Cells via Inhibiting Transforming Growth Factor-beta 1 (TGF-β1)-Induced Hela cells p38 Mitogen-Activated Protein Kinase (MAPK) Activation

BACKGROUND Epithelial-mesenchymal transition (EMT) plays a key role in promoting invasion and metastasis of tumor cells. SEMA4C can regulate the generation of transforming growth factor-beta 1 (TGF-ß1)-induced EMT in cervical cancer. This study investigated the relationship between the regulation of SEMA4C on TGF-ß1-induced p38 mitogen-activated protein kinase (MAPK) activation and invasion and metastasis of cervical cancer. MATERIAL AND METHODS Hela-shSEMA4C cell line was established and the success of transfection was confirmed with fluorescence intensity. Cell experiments were divided into 2 groups. Group 1 was Hela, Hela-shNC, and Hela-shSEMA4C; and Group 2 was Hela, Hela-shNC, Hela-shSEMA4C, Hela+TGF-ß1, Hela-shNC+TGF-ß1, and Hela-shSEMA4C+TGF-ß1. Group 1 was detected for SEMA4C mRNA expression by real-time polymerase chain reaction (RT-PCR), cell viability by Cell Counting Kit-8 (CCK-8), F-actin fluorescence intensity by immunofluorescence, cell migration by scratch test, and cell invasion by invasion test. Group 2 was analyzed for E-cadherin fluorescence intensity by immunofluorescence, human fibronectin (FN) content by enzyme-linked immunosorbent assay (ELISA), and SEMA4C, E-cadherin and p-p38 expressions by Western blot. RESULTS For Group 1, compared with Hela and Hela-shNC subgroups, the SEMA4C mRNA expression, cell viability, F-actin fluorescence intensity, cell migration and invasion ability in the Hela-shSEMA4C subgroup were significantly decreased (P<0.05). For Group 2, compared with Hela and Hela-shNC subgroups, the E-cadherin expression and fluorescence intensity in the Hela-shSEMA4C subgroup were significantly increased (P<0.01), while the FN content, SEMA4C, and p-p38 MAPK expressions were significantly decreased (P<0.01). Compared with Hela-shNC+TGF-ß1 and Hela+TGF-ß1 subgroups, the E-cadherin expression and fluorescence intensity in the Hela-shSEMA4C+TGF-ß1 subgroup were significantly increased (P<0.01), while the FN content, SEMA4C and p-p38 expressions were significantly decreased (P<0.01). CONCLUSIONS Downregulation of SEMA4C can inhibit EMT and the invasion and metastasis of cervical cancer cells via inhibiting TGF-ß1-induced Hela cells p38 MAPK activation.

SEMA4C is a novel target to limit osteosarcoma growth, progression, and metastasis

Semaphorins, specifically type IV, are important regulators of axonal guidance and have been increasingly implicated in poor prognoses in a number of different solid cancers. In conjunction with their cognate PLXNB family receptors, type IV members have been increasingly shown to mediate oncogenic functions necessary for tumor development and malignant spread. In this study, we investigated the role of semaphorin 4C (SEMA4C) in osteosarcoma growth, progression, and metastasis. We investigated the expression and localization of SEMA4C in primary osteosarcoma patient tissues and its tumorigenic functions in these malignancies. We demonstrate that overexpression of SEMA4C promotes properties of cellular transformation, while RNAi knockdown of SEMA4C promotes adhesion and reduces cellular proliferation, colony formation, migration, wound healing, tumor growth, and lung metastasis. These phenotypic changes were accompanied by reductions in activated AKT signaling, G1 cell cycle delay, and decreases in expression of mesenchymal marker genes SNAI1, SNAI2, and TWIST1. Lastly, monoclonal antibody blockade of SEMA4C in vitro mirrored that of the genetic studies. Together, our results indicate a multi-dimensional oncogenic role for SEMA4C in metastatic osteosarcoma and more importantly that SEMA4C has actionable clinical potential.

miR-25-3p reverses epithelial-mesenchymal transition via targeting Sema4C in cisplatin-resistance cervical cancer cells

Acquisition of epithelial-mesenchymal transition (EMT) has recently been proposed as an important contributor of drug resistance in cervical cancer cells. However, the underlying mechanisms are still unclear. MicroRNAs play a crucial role in regulating EMT. The aim of this study was to explore the potential role of miR-25-3p in regulating EMT in cisplatin-resistant (CR) cervical cancer cells. To this end, we established stable CR cervical cancer cells, HeLa-CR and CaSki-CR, and investigated the function of miR-25-3p in regulating EMT. It is found that CR cervical cancer cells possessed more EMT characteristics and demonstrated higher migratory abilities and invasiveness. miR-25-3p downregulation was also seen in HeLa-CR and CaSki-CR cells. Of note, ectopic expression of miR-25-3p reversed the EMT phenotype and sensitized CR cells to cisplatin via targeting Sema4C. Furthermore, stable overexpression of miR-25-3p in HeLa-CR cells suppressed tumor growth in mice, downregulated Sema4C and Snail, and upregulated E-cadherin compared with the control group. These results suggest that miR-25-3p is an important regulator of cervical cancer EMT and chemoresistance. Thus, upregulation of miR-25-3p could be a novel approach to treat cervical cancers that are resistant to chemotherapy.

Semaphorin 4C Protects against Allergic Inflammation: Requirement of Regulatory CD138+ Plasma Cells

The regulatory properties of B cells have been studied in autoimmune diseases; however, their role in allergic diseases is poorly understood. We demonstrate that Semaphorin 4C (Sema4C), an axonal guidance molecule, plays a crucial role in B cell regulatory function. Mice deficient in Sema4C exhibited increased airway inflammation after allergen exposure, with massive eosinophilic lung infiltrates and increased Th2 cytokines. This phenotype was reproduced by mixed bone marrow chimeric mice with Sema4C deficient only in B cells, indicating that B lymphocytes were the key cells affected by the absence of Sema4C expression in allergic inflammation. We determined that Sema4C-deficient CD19⁺CD138⁺ cells exhibited decreased IL-10 and increased IL-4 expression in vivo and in vitro. Adoptive transfer of Sema4c^-/- CD19⁺CD138⁺ cells induced marked pulmonary inflammation, eosinophilia, and increased bronchoalveolar lavage fluid IL-4 and IL-5, whereas adoptive transfer of wild-type CD19⁺CD138⁺IL-10⁺ cells dramatically decreased allergic airway inflammation in wild-type and Sema4c^-/- mice. This study identifies a novel pathway by which Th2-mediated immune responses are regulated. It highlights the importance of plasma cells as regulatory cells in allergic inflammation and suggests that CD138⁺ B cells contribute to cytokine balance and are important for maintenance of immune homeostasis in allergic airways disease. Furthermore, we demonstrate that Sema4C is critical for optimal regulatory cytokine production in CD138⁺ B cells.

MiR-125b regulates epithelial-mesenchymal transition via targeting Sema4C in paclitaxel-resistant breast cancer cells

Emerging evidence has demonstrated that microRNAs (miRNA) play a critical role in chemotherapy-induced epithelial-mesenchymal transition (EMT) in breast cancer. However, the underlying mechanism of chemotherapy-mediated EMT has not been fully understood. To address this concern, we explored the role of miR-125b in regulation of EMT in stable paclitaxel-resistant (PR) breast cancer cells, namely MCF-7 PR and SKBR3 PR, which have displayed mesenchymal features. Our results illustrated that miR-125b was significantly downregulated in PR cells. Moreover, ectopic expression of miR-125b by its mimics reversed the phenotype of EMT in PR cells. Furthermore, we found that miR-125b governed PR-mediate EMT partly due to governing its target Sema4C. More importantly, overexpression of miR-125b or depletion of Sema4C sensitized PR cells to paclitaxel. These findings suggest that up-regulation of miR-125b or targeting Sema4C could serve as novel approaches to reverse chemotherapy resistance in breast cancers.

MiR-138 inhibits cell proliferation and reverses epithelial-mesenchymal transition in non-small cell lung cancer cells by targeting GIT1 and SEMA4C

Non-small-cell lung cancer (NSCLC) is one of the most common and lethal malignant tumours worldwide with a poor 5-year survival rate. Recent studies indicated that miRNAs have been involved in the tumorigenic driver pathways in NSCLC, but the relevant molecular mechanisms are not well-understood. In this study, we investigated the biological functions and molecular mechanisms of miR-138 in human NSCLC. The effects of miR-138 on the NSCLC cell growth and epithelial-mesenchymal transition (EMT) were first examined. Then the targeting connections of miR-138 with G-protein-coupled receptor kinase-interacting protein 1 (GIT1) and semaphorin 4C (SEMA4C) were confirmed by dual luciferase reporter assays. Finally, the effects of GIT1 and SEMA4C on the NSCLC cell growth and EMT were investigated respectively. We found that the ectopic expression of miR-138 resulted in a significant inhibition of NSCLC growth and reversion of EMT. GIT1 and SEMA4C were identified as two novel targets of miR-138. Furthermore, GIT1 and SEMA4C knockdown inhibited the cell growth and reversed EMT, just like the effects of miR-138 overexpression on NSCLC cells, whereas ectopic expression of GIT1 and SEMA4C partly rescued the suppressive effects of miR-138 in NSCLC cells. These data represent a crucial step towards the understanding of the novel roles and molecular mechanism of miR-138, GIT1 and SEMA4C in NSCLC progression, which may provide some new targets or prognostic biomarkers for NSCLC treatment, thus having implications in translational oncology.