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Introduction Lung tumor growth and metastasis requires angiogenesis--the formation of new blood vessels (1, 2). Angiogenesis is typically triggered by hypoxia, which stabilizes hypoxia-inducible transcription factors (HIFs) including HIF1[alpha] and [...], Lung cancer progression relies on angiogenesis, which is a response to hypoxia typically coordinated by hypoxia- inducible transcription factors (HIFs), but growing evidence indicates that transcriptional programs beyond HIFs control tumor angiogenesis. Here, we show that the redox-sensitive transcription factor BTB and CNC homology 1 (BACH1) controls the transcription of a broad range of angiogenesis genes. BACH1 is stabilized by lowering ROS levels; consequently, angiogenesis gene expression in lung cancer cells, tumor organoids, and xenograft tumors increased substantially following administration of vitamins C and E and N-acetylcysteine in a BACH1-dependent fashion under normoxia. Moreover, angiogenesis gene expression increased in endogenous BACH1-overexpressing cells and decreased in SACH7-knockout cells in the absence of antioxidants. BACH1 levels also increased upon hypoxia and following administration of prolyl hydroxylase inhibitors in both HfF7A-knockout and WT cells. BACH1 was found to be a transcriptional target of HIF1[alpha], but BACH1's ability to stimulate angiogenesis gene expression was HIF1[alpha] independent. Antioxidants increased tumor vascularity in vivo in a BACH1- dependent fashion, and overexpressing BACH1 rendered tumors sensitive to antiangiogenesis therapy. BACH1 expression in tumor sections from patients with lung cancer correlated with angiogenesis gene and protein expression. We conclude that BACH1 is an oxygen- and redox-sensitive angiogenesis transcription factor.

Ovarian cancer is a lethal gynecological malignancy, and to improve survival, it is important to identify novel prognostic and therapeutic targets. In this study, we present a role for p21-activated kinase 4 (Pak4) in ovarian cancer progression. We show a significant association between increased expression of Pak4 and its activated form, phosphorylated (p)-Pak4 [Ser.sup.474] with metastasis of ovarian cancers, shorter overall and disease-free survival, advanced stage and high-grade cancers, serous/clear cell histological subtypes, and reduced chemosensitivity. Pak4 overexpression was also observed in ovarian cancer cell lines. Pak4 and p-Pak4 expression were detected both in the nucleus and cytoplasm of ovarian cancer cells, in vitro as well as in vivo. Stable knockdown of Pak4 in ovarian cancer cell lines led to reduced cell migration, invasion, and proliferation, along with reduced c-Src, ERK1/2, and epidermal growth factor receptor (EGFR) activation and decreased matrix metalloprotainase 2 (MMP2) expression. Conversely, Pak4 overexpression promoted ovarian cancer cell migration and invasion in a c-Src, MEK-1, MMP2, and kinase-dependent manner, and induced cell proliferation through the Pak4/c-Src/EGFR pathway that controls cyclin D1 and CDC25A expression. Stable knockdown of Pak4 also impeded tumor growth and dissemination in nude mice. This report reveals the association between Pak4 and important clinicopathologic parameters, suggesting Pak4 to be a significant prognostic marker and potential therapeutic molecular target in ovarian cancer. The implied possible cross-talk between Pak4 and EGFR suggests the potential of dual targeting of EGFR and Pak4 as a unique therapeutic approach for cancer therapy. prognostic marker | therapeutic target doi/ 10.1073/pnas.0907481107

Cell anchorage is required for cell proliferation of untransformed cells, whereas anchorage-independent growth can be induced by oncogenes and is a hallmark of transformation. Whereas anchorage-dependent control of the progression of the [G.sub.1] phase of the cell cycle has been extensively studied, it is less clear whether and how anchorage may control other cell cycle phases and whether oncogenes may affect such controls. Here, we found that lack of cell anchorage did not influence progression through the cell cycle S phase, [G.sub.2] phase, or most of mitosis of primary human fibroblasts. However, unanchored fibroblasts could not complete cytokinesis. The cleavage furrow and central spindle were still formed in the absence of anchorage, but cells were unable to complete ingression, causing binucleation. Importantly, V12 H-Ras-transformed fibroblasts and two cancer cell lines progressed through the entire cell cycle without anchorage, including through cytokinesis. This indicates that oncogenic signaling may contribute to anchorage-independent growth and tumorigenesis by promoting the final cleavage furrow ingression during cytokinesis. cell adhesion | integrin | extracellular matrix | signaling | cell cycle

Integrin [alpha]v is required for melanoma cell survival and tumor growth in various models. To elucidate integrin [alpha]v-mediated melanoma cell survival mechanisms, we used a three-dimensional (3D) collagen gel model mimicking the pathophysiological microenvironment of malignant melanoma in the dermis. We found that integrin [alpha]v inactivated p53 and that suppression of p53 activity by dominant negative p53 or p53-small interfering RNA obviated the need for integrin [alpha]v for melanoma cell survival in 3D-collagen and for tumor growth in vivo. This indicates that integrin [alpha]v-mediated inactivation of p53 functionally controls melanoma cell survival. Furthermore, we found that melanoma cell integrin [alpha]v was required for MAPK kinase (MEK) 1 and extracellular signal-regulated kinase (ERK)1/2 activity in 3D-collagen, whereas inhibition of MEK1 activity induced apoptosis. Surprisingly, MEK1 and ERK1/2 activities were restored in integrin [alpha]v-negative melanoma cells by suppression of p53, whereas concomitant block of MEK1 induced apoptosis. This suggests that integrin [alpha]v controls melanoma cell survival in 3D-collagen through a pathway involving p53 regulation of MEK1 signaling.

Angiogenesis relies on growth factors and vascular cell adhesion events. Integrins and growth factors can activate the ras/MAP kinase pathway in vitro, but it is not known how the signals influence endothelial cells during angiogenesis. The role of MAP kinases and the need for integrin ligation during angiogenesis was examined. How integrin alphavbeta3 and bFGF influences MAP kinase activity in angiogenic blood vessels in the chick chroioallantoic membrane was also investigated.

The matrix metalloproteinase MMP-2 localizes in a proteolytically active form on the surface of invasive cells due to its ability to bind directly to alpha-v-beta-3 integrin. This facilitates cell-mediated collagen degradation. The binding requires the C-terminal region of MMP-2. MMP-2 and alpha-v-beta-3 integrin specifically colocalize on angiogenic blood vessels and melanoma cells. Alpha-v-beta-3 functions as a cell-surface receptor that controls both matrix motility and proteolytic degradation.

Background: Genetically encoded sensors developed on the basis of green fluorescent protein (GFP)-like proteins are becoming more and more popular instruments for monitoring cellular analytes and enzyme activities in living cells and transgenic organisms. In particular, a number of Ca2+ sensors have been developed, either based on FRET (Fluorescence Resonance Energy Transfer) changes between two GFP-mutants or on the change in fluorescence intensity of a single circularly permuted fluorescent protein (cpFP). Results: Here we report significant progress on the development of the latter type of Ca2+ sensors. Derived from the knowledge of previously reported cpFP-based sensors, we generated a set of cpFP-based indicators with different spectral properties and fluorescent responses to changes in Ca2+ concentration. Two variants, named Case12 and Case16, were characterized by particular high brightness and superior dynamic range, up to 12-fold and 16.5-fold increase in green fluorescence between Ca2+-free and Ca2+-saturated forms. We demonstrated the high potential of these sensors on various examples, including monitoring of Ca2+ response to a prolonged glutamate treatment in cortical neurons. Conclusion: We believe that expanded dynamic range, high brightness and relatively high pHstability should make Case12 and Case16 popular research tools both in scientific studies and high throughput screening assays. [ABSTRACT FROM AUTHOR]

Present a study which examines the role of ras/MAP (mitogen-activated protein ) kinase in angiogenesis since integrins such as ...3 which have been linked to angiogenesis. Information on the kinetics of ...3 expression during angiogenesis; Materials and methodology used to conduct study; Results of study.