Prostate cancer is one of the most common cancer for men worldwide with advanced forms showing supernumerary or clustered centrosomes. Hematological and neurological expressed 1 (HN1) also known as Jupiter Microtubule Associated Homolog 1 (JPT1) belongs to a small poorly understood family of genes that are evolutionarily conserved across vertebrate species. The co-expression network of HN1 from the TCGA PRAD dataset indicates the putative role of HN1 in centrosome-related processes in the context of prostate cancer. HN1 expression is low in normal RWPE-1 cells as compared to cancerous androgen-responsive LNCaP and androgen insensitive PC-3 cells. HN1 overexpression resulted in differential response for cell proliferation and cell cycle changes in RWPE-1, LNCaP, and PC-3 cells. Since HN1 overexpression increased the proliferation rate in PC-3 cells, these cells were used for functional characterization of HN1 in advanced prostate carcinogenesis. Furthermore, alterations in HN expression led to an increase in abnormal to normal nuclei ratio and increased chromosomal aberrations in PC-3 cells. We observed the co-localization of HN1 with γ-tubulin foci in prostate cancer cells, further validated by immunoprecipitation. HN1 was observed as physically associated with γ-tubulin and its depletion led to increased γ-tubulin foci and disruption in microtubule spindle assembly. Higher HN1 expression was correlated with prostate cancer as compared to normal tissues. The restoration of HN1 expression after silencing suggested that it has a role in centrosome clustering, implicating a potential role of HN1 in cell division as well as in prostate carcinogenesis warranting further studies.

The studies on the relationship between inflammation and cancer progression have been mostly carried out with monolayer cell cultures in vitro, which can be insufficient to mimic tumor tissue. Here, we established a three-dimensional (3D) cell culture model of inflammatory microenvironment for prostate cancer cells to better evaluate the role of inflammation in prostate carcinogenesis. Formation of the cell spheroids has been achieved for LNCaP, Du145, LNCaP-104r2 prostate cancer cell lines but not for RWPE1 normal prostate epithelial cell and PC3 by using 3D Petri Dish^®. We also showed that cells in inflammatory conditioned media might have a different response based on the culturing method. Overall, we are suggesting that 3D cell culture model can be a useful tool to study molecular alterations on proliferation and migration/invasion of tumor cells related to inflammation.

VE-cadherin controls endothelial junction integrity, and thereby inflammation-induced vascular permeability and leukocyte extravasation. The adhesive function of VE-cadherin is influenced by its binding to β-catenin, which is linked by α-catenin to actin. Plakoglobin can replace β-catenin in such complexes, and both types of complexes co-exist in endothelial cells. Here, we have investigated whether β-catenin and plakoglobin differ in their relevance for controlling endothelial junctions. Based on gene silencing in vitro and conditional endothelium-specific gene inactivation in mice in vivo, we found that both leukocyte diapedesis through endothelium and induction of vascular permeability by inflammatory mediators depend on plakoglobin, but not β-catenin. Mechanistically, we demonstrated that plakoglobin is crucial for the generation of tension across VE-cadherin by transmigrating leukocytes and by inflammatory mediators, whereas β-catenin was dispensable in this context. Transgenic mice expressing a VE-cadherin tension sensor revealed that plakoglobin is essential in vivo for histamine-induced tension across VE-cadherin. Thus, plakoglobin, but not β-catenin, is needed for leukocyte diapedesis, the induction of vascular permeability, and the stimulation of mechanical tension across VE-cadherin.