Growth factor receptor tyrosine kinase (RTK) pathway activation is a key mechanism for mediating cancer growth, survival, and treatment resistance. Cognate ligands play crucial roles in autocrine or paracrine stimulation of these RTK pathways. Here, we show SEMA3C drives activation of multiple RTKs including EGFR, ErbB2, and MET in a cognate ligand‐independent manner via Plexin B1. SEMA3C expression levels increase in castration‐resistant prostate cancer (CRPC), where it functions to promote cancer cell growth and resistance to androgen receptor pathway inhibition. SEMA3C inhibition delays CRPC and enzalutamide‐resistant progression. Plexin B1 sema domain‐containing:Fc fusion proteins suppress RTK signaling and cell growth and inhibit CRPC progression of LNCaP xenografts post‐castration in vivo. SEMA3C inhibition represents a novel therapeutic strategy for treatment of advanced prostate cancer.

The use of the green fluorescent protein (GFP) to label specific cell types and track gene expression in animal models, such as mice, has evolved to become an essential tool in biological research. Transgenic animals expressing genes of interest linked to GFP, either as a fusion protein or transcribed from an internal ribosomal entry site (IRES) are widely used. Enhanced GFP (eGFP) is the most common form of GFP used for such applications. However, a red fluorescent protein (RFP) would be highly desirable for use in dual-labeling applications with GFP derived fluorescent proteins, and for deep in vivo imaging of tissues. Recently, a new generation of monomeric (m)RFPs, such as monomeric (m)Cherry, has been developed that are potentially useful experimentally. mCherry exhibits brighter fluorescence, matures more rapidly, has a higher tolerance for N-terminal fusion proteins, and is more photostable compared with its predecessor mRFP1. mRFP1 itself was the first true monomer derived from its ancestor DsRed, an obligate tetramer in vivo. Here, we report the successful generation of a transgenic mouse line expressing mCherry as a fluorescent marker, driven by the ubiquitin-C promoter. mCherry is expressed in almost all tissues analyzed including pre- and post-implantation stage embryos, and white blood cells. No expression was detected in erythrocytes and thrombocytes. Importantly, we did not encounter any changes in normal development, general physiology, or reproduction. mCherry is spectrally and genetically distinct from eGFP and, therefore, serves as an excellent red fluorescent marker alone or in combination with eGFP for labelling transgenic animals.

Prostate cancer (PCa) is among the most commonly-occurring cancers worldwide and a leader in cancer-related deaths. Local non-invasive PCa is highly treatable but limited treatment options exist for those with locally-advanced and metastatic forms of the disease underscoring the need to identify mechanisms mediating PCa progression. The semaphorins are a large grouping of membrane-associated or secreted signalling proteins whose normal roles reside in embryogenesis and neuronal development. In this context, semaphorins help establish chemotactic gradients and direct cell movement. Various semaphorin family members have been found to be up- and down-regulated in a number of cancers. One family member, Semaphorin 3 C (SEMA3C), has been implicated in prostate, breast, ovarian, gastric, lung, and pancreatic cancer as well as glioblastoma. Given SEMA3C’s roles in development and its augmented expression in PCa, we hypothesized that SEMA3C promotes epithelial-to-mesenchymal transition (EMT) and stem-like phenotypes in prostate cells. In the present study we show that ectopic expression of SEMA3C in RWPE-1 promotes the upregulation of EMT and stem markers, heightened sphere-formation, and cell plasticity. In addition, we show that SEMA3C promotes migration and invasion in vitro and cell dissemination in vivo.

Despite the amenability of early-stage prostate cancer to surgery and radiation therapy, locally advanced and metastatic prostate cancer is clinically problematic. Chemical castration is often used as a first-line therapy for advanced disease, but progression to the castration-resistant prostate cancer phase occurs with dependable frequency, largely through mutations to the androgen receptor (AR), aberrant AR signaling, and AR-independent mechanisms, among other causes. Semaphorin 3C (SEMA3C) is a secreted signaling protein that is essential for cardiac and neuronal development and has been shown to be regulated by the AR, to drive epithelial-to-mesenchymal transition and stem features in prostate cells, to activate receptor tyrosine kinases, and to promote cancer progression. Given that SEMA3C is linked to several key aspects of prostate cancer progression, we set out to explore SEMA3C inhibition by small molecules as a prospective cancer therapy. A homology-based SEMA3C protein structure was created, and its interaction with the neuropilin (NRP)-1 receptor was modeled to guide the development of the corresponding disrupting compounds. Experimental screening of 146 in silico‒identified molecules from the National Cancer Institute library led to the discovery of four promising candidates that effectively bind to SEMA3C, inhibit its association with NRP1, and attenuate prostate cancer growth. These findings provide proof of concept for the feasibility of inhibiting SEMA3C with small molecules as a therapeutic approach for prostate cancer.

These results indicate that LASP1 is negatively regulated by AR at the transcriptional level and promotes tumor growth through induction of cell cycle, ultimately suggesting that LASP1 may be a potential target in prostate cancer treatment. Prostate 77:309-320, 2017. © 2016 Wiley Periodicals, Inc.

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for induction of protective T cell immunity. In vivo studies have shown that TDM injection resulted in suppression of tumor growth in hepatoma and ocular squamous cell carcinoma. To date, the effect of TDM on Urothelial carcinoma (UC) cells has not been studied. The objectives of this study were to measure the cytotoxic effects of TDM on BCG sensitive and BCG resistant UC cell lines and determine its mechanism of action relative to BCG.METHODS: BCG sensitive (253J, T24) and BCG resistant (RT4) UC cell lines were used to study the effect of TDM. The biologic response to TDM was compared with the response to BCG. Response endpoints included viability, LDH release, HMGB1 release, caspase-3 activity, intracellular signaling pathways (NF-kB), gene transactivation and global profiling of reactive oxygen species(ROS) and nitrogen species (RNS). RESULTS: TDM cytotoxicity was similar in both BCG sensitive and resistant cell lines. TDM significantly decreased viability (T24, p < 0.001; 253J, p < 0.005, RT4 p < 0.001) with 50 % cells remained viable after 24h. TDM exposure resulted in a 3-6 fold increase in LDH release, 24h post TDM treatment (T24 and 253J, p < 0.005, RT4 p < 0.01). Significant release of HMGB1 was observed (T24, p < 0.001; 253J, p < 0.05) after 24h. TDM exposure resulted in 4-6 fold increase in caspase-3 activity (T24 and 253J, p < 0.001) after 24h. Significant increase in transgene activation of IL-6, iNOS and p21 genes (T24 and 253J, p < 0.05) was observed after 6h. NF-kB activation was not altered upon TDM exposure (T24 and 253J, p ¼ 0.2). Global profiling of ROS/RNS at 6h and 12h showed significant decrease in H 2 O 2 levels post TDM exposure (T24 and 253J, p < 0.05) but no significant changes in nitric oxide (NO) and superoxide levels.CONCLUSIONS: TDM is cytotoxic to both BCG sensitive and BCG resistant UC cell lines. TDM treatment results in apoptotic as well as necrotic cell death as it induces both caspase activation and HMGB1 release. Similar to BCG, it activates iNOS, p21 and IL-6 gene expression. However, Contrary to BCG, the lack of NF-kB activation and NF-kB dependent gene expression suggests that TDM functions through an NF-kB independent pathway. Lack of NF-kB activation may be related to the absence of H 2 O 2 and NO generation with a reduction in oxidative stress relative to BCG. TDM treatment might provide new avenues for BCG refractory tumors.

and also significantly higher in RCC samples as compared to normal kidney samples (p<0.0001). The higher expression of versican was significantly correlated with high stage disease and systematic metastasis (p<0.05). When the expression level of the versican mRNA transcript was divided into 2 groups based on median values, higher expression was significantly associated with overall survival (OS) after a radical nephrectomy (p¼0.0235). After transfection of versican siRNA, cell viability, migration, and invasion ability were significantly inhibited in the RCC cell lines.CONCLUSIONS: We concluded that versican may be an attractive target for designing improved diagnostic and therapeutic strategies for treatment of advanced RCC.