Importance of the putative furin recognition site 742RNRR745 for antiangiogenic Sema3C activity in vitro

Class-3 semaphorins: Potent multifunctional modulators for angiogenesis-associated diseases

Semaphorins, the neuronal guidance cues, were shown to have broad influences on pathophysiological processes such as bone remodeling, immune responses, and angiogenesis. In particular, Class-3 Semaphorins (SEMA3) is considered a vital regulator involved in angiogenesis. Scientific evidence has pointed to the role of angiogenesis in many diseases, and numerous efforts have been made to explore the possibilities of curing those diseases by targeting angiogenesis. Nevertheless, the efficacies are limited owing to the complex mechanisms of angiogenesis. Hence, investigating the mechanisms of SEMA3 in angiogenesis may contribute to novel therapeutics for diseases. Previous reviews mainly focused on the various functions of semaphorins in one particular disease, and the specific angiogenesis mechanism of SEMA3 in diverse diseases has not been well elucidated. Additionally, the role of SEMA3 in angiogenesis remains elusive, as contradicting results have been found in different disease types. Some evidence from recent studies implies that, while most SEMA3 molecules inhibit pathological angiogenesis in different diseases, occasionally SEMA3 may also promote angiogenesis. This review summarizes the specific role of SEMA3 in a variety of angiogenesis-associated diseases, and documents SEMA3 may be a promising therapeutic target for treating angiogenesis-associated diseases.

Semaphorin-3C Is Upregulated in Polycystic Kidney Epithelial Cells and Inhibits Angiogenesis of Glomerular Endothelial Cells

BACKGROUND

Polycystic kidney disease (PKD) is a hereditary disease characterized by cyst formation in the kidneys bilaterally. It has been observed that semaphorin-3C (SEMA3C) is overexpressed in polycystic kidney epithelial cells. It is hypothesized that upregulated SEMA3C would contribute to survival of polycystic kidney epithelial cells. Furthermore, as the kidney is a highly vascularized organ, the secreted SEMA3C from PKD epithelial cells will affect glomerular endothelial cells (GECs) in a paracrine manner.

METHODS

To evaluate the effect of SEMA3C on renal cells, siSEMA3C-treated PKD epithelial cells were used for further analysis, and GECs were exposed to recombinant SEMA3C (rSEMA3C). Also, co-culture and treatment of conditioned media were employed to confirm whether PKD epithelial cells could influence on GECs via SEMA3C secretion.

RESULTS

SEMA3C knockdown reduced proliferation of PKD epithelial cells. In case of GECs, exposure to rSEMA3C decreased angiogenesis, which resulted from suppressed migratory ability not cell proliferation.

CONCLUSIONS

This study indicates that SEMA3C is the aggravating factor in PKD. Thus, it is proposed that targeting SEMA3C can be effective to mitigate PKD.

The Anti-Tumorigenic Activity of Sema3C in the Chick Embryo Chorioallantoic Membrane Model

Sema3C protein, a member of the class 3 family of secreted semaphorins, play an important role in tumor development by regulating cell proliferation, migration, invasion, and angiogenesis processes. Depending on the type and malignancy grade of the tumor, Sema3C function remains controversial. In this study, we constructed a stably overexpressing Sema3C glioblastoma cell line U87 MG and tested it on the chicken embryo chorioallantoic membrane (CAM) model with the aim to reveal Sema3C protein function on angiogenesis process in ovo. Our experiments showed that Sema3C not only affects angiogenesis of CAM by inhibiting neovascularization but also acts as an anti-tumorigenic molecule by hampering U87 MG cell invasion into mesenchyme. The effects of Sema3C on CAM were similar to the effects of anti-epileptic drug sodium valproate (NaVP). Both, anti-angiogenic and anti-tumorigenic activities of Sema3C were enhanced by the treatment of NaVP and, importantly, were not attributed to the cytotoxic effects. Our studies suggest that Sema3C could be a promising target for glioblastoma treatment.

Semaphorin 3C as a Therapeutic Target in Prostate and Other Cancers

The semaphorins represent a large family of signaling molecules with crucial roles in neuronal and cardiac development. While normal semaphorin function pertains largely to development, their involvement in malignancy is becoming increasingly evident. One member, Semaphorin 3C (SEMA3C), has been shown to drive a number of oncogenic programs, correlate inversely with cancer prognosis, and promote the progression of multiple different cancer types. This report surveys the body of knowledge surrounding SEMA3C as a therapeutic target in cancer. In particular, we summarize SEMA3C's role as an autocrine andromedin in prostate cancer growth and survival and provide an overview of other cancer types that SEMA3C has been implicated in including pancreas, brain, breast, and stomach. We also propose molecular strategies that could potentially be deployed against SEMA3C as anticancer agents such as biologics, small molecules, monoclonal antibodies and antisense oligonucleotides. Finally, we discuss important considerations for the inhibition of SEMA3C as a cancer therapeutic agent.

Class-3 Semaphorins and Their Receptors: Potent Multifunctional Modulators of Tumor Progression

Semaphorins are the products of a large gene family containing 28 genes of which 21 are found in vertebrates. Class-3 semaphorins constitute a subfamily of seven vertebrate semaphorins which differ from the other vertebrate semaphorins in that they are the only secreted semaphorins and are distinguished from other semaphorins by the presence of a basic domain at their C termini. Class-3 semaphorins were initially characterized as axon guidance factors, but have subsequently been found to regulate immune responses, angiogenesis, lymphangiogenesis, and a variety of additional physiological and developmental functions. Most class-3 semaphorins transduce their signals by binding to receptors belonging to the neuropilin family which subsequently associate with receptors of the plexin family to form functional class-3 semaphorin receptors. Recent evidence suggests that class-3 semaphorins also fulfill important regulatory roles in multiple forms of cancer. Several class-3 semaphorins function as endogenous inhibitors of tumor angiogenesis. Others were found to inhibit tumor metastasis by inhibition of tumor lymphangiogenesis, by direct effects on the behavior of tumor cells, or by modulation of immune responses. Notably, some semaphorins such as sema3C and sema3E have also been found to potentiate tumor progression using various mechanisms. This review focuses on the roles of the different class-3 semaphorins in tumor progression.