Vascular endothelial growth factor receptor inhibitor SU5416 suppresses lymphocyte generation and immune responses in mice by increasing plasma corticosterone

Anti-Angiogenic Treatments Interact with Steroid Secretion in Inflammatory Breast Cancer Triple Negative Cell Lines

Human inflammatory breast cancer (IBC) is a highly angiogenic disease for which antiangiogenic therapy has demonstrated only a modest response, and the reason for this remains unknown. Thus, the purpose of this study was to determine the influence of different antiangiogenic therapies on in vitro and in vivo steroid hormone and angiogenic growth factor production using canine and human inflammatory breast carcinoma cell lines as well as the possible involvement of sex steroid hormones in angiogenesis. IPC-366 and SUM149 cell lines and xenotransplanted mice were treated with different concentrations of VEGF, SU5416, bevacizumab and celecoxib. Steroid hormone (progesterone, dehydroepiandrostenedione, androstenedione, testosterone, dihydrotestosterone, estrone sulphate and 17β-oestradiol), angiogenic growth factors (VEGF-A, VEGF-C and VEGF-D) and IL-8 determinations in culture media, tumour homogenate and serum samples were assayed by EIA. In vitro, progesterone- and 17β-oestradiol-induced VEGF production promoting cell proliferation and androgens are involved in the formation of vascular-like structures. In vivo, intratumoural testosterone concentrations were augmented and possibly associated with decreased metastatic rates, whereas elevated E1SO4 concentrations could promote tumour progression after antiangiogenic therapies. In conclusion, sex steroid hormones could regulate the production of angiogenic factors. The intratumoural measurement of sex steroids and growth factors may be useful to develop preventive and individualized therapeutic strategies.

Diagnostic and therapeutic implications of the vascular endothelial growth factor family in cancer

Cancer progression is attained by uncontrolled cell division and metastasis. Increase in tumor size triggers different vascular channel formation to address cell nutritional demands. These channels are responsible for transferring of nutrients and gaseous to the cancer cells. Cancer vascularization is regulated by numerous factors including vascular endothelial growth factors (VEGFs). These factors play an important role during embryonic development. Members included in this group are VEGFA, VEGFB, VEGFC, PIGF and VEGFD which markedly influence cellular growth and apoptosis. Being freely diffusible these proteins act in both autocrine and paracrine fashions. In this review, genetic characterization these molecules and their putative role in cancer staging has been elaborated. Prognostic significance of these molecules along with different stages of cancer has also been summarized. Brief outline of ongoing efforts to target hot spot target sites against these VEGFs and their cognate limitations for therapeutic implications are also highlighted.

In Vitro Assays for Endothelial Cell Functions Required for Angiogenesis: Proliferation, Motility, Tubular Differentiation, and Matrix Proteolysis

This chapter deconstructs the process of angiogenesis into its component parts in order to provide simple assays to measure discrete endothelial cell functions. The techniques described will be suitable for studying stimulators and/or inhibitors of angiogenesis and determining which aspect of the process is modulated. The assays are designed to be robust and straightforward, using human umbilical vein endothelial cells, but with an option to use other sources such as microvascular endothelial cells from various tissues or lymphatic endothelial cells. It must be appreciated that such reductionist approaches cannot cover the complexity of the angiogenic process as a whole, incorporating as it does a myriad of positive and negative signals, three-dimensional interactions with host tissues and many accessory cells including fibroblasts, macrophages, pericytes and platelets. The extent to which in vitro assays predict physiological or pathological processes in vivo (e.g., wound healing, tumor angiogenesis) or surrogate techniques such as the use of Matrigel™ plugs, sponge implants, corneal assays etc remains to be determined.

Cutting edge: critical role for C5aRs in the development of septic lymphopenia in mice

In the early stages of sepsis, lymphocytes undergo apoptosis, resulting in lymphopenia and immunosuppression. The trigger for septic lymphopenia is unknown. Using the polymicrobial model of murine sepsis, we investigated the role of C5a receptors in septic lymphopenia. In wild-type mice, cecal ligation and puncture resulted in splenocyte apoptosis and significant lymphopenia after 3 d, which was not observed in C5aR1(-/-) or C5aR2(-/-) mice. Our data show that mouse neutrophils exposed to recombinant mouse C5a cause release of histones in a dose-dependent and time-dependent manner. Histone levels in spleen were significantly elevated following cecal ligation and puncture but were reduced by the absence of C5aR1. Histones induced significant lymphocyte apoptosis in vitro. Ab-mediated neutralization of histones prevented the development of lymphopenia in sepsis. Together, these results describe a new pathway of septic lymphopenia involving complement and extracellular histones. Targeting of this pathway may have therapeutic benefit for patients with sepsis or other serious illness.