Oxidized low-density lipoprotein (oxLDL) accumulates early in atherosclerosis and promotes endothelial nuclear factor κB (NF-κB) activation, proinflammatory gene expression and monocyte adhesion. Like for other atherogenic factors, oxLDL-induced proinflammatory responses requires integrin-dependent focal adhesion kinase (FAK, also known as PTK2) signaling; however, the mechanism by which FAK mediates oxLDL-dependent NF-κB signaling has yet to be revealed. We now show that oxLDL induces NF-κB activation and VCAM-1 expression through FAK-dependent IκB kinase β (IKKβ, also known as IKBKB) activation. We further identify FAK-dependent activation of p90 ribosomal S6 kinase family proteins (RSK) as a crucial mediator of oxLDL-dependent IKKβ and NF-κB signaling, as inhibiting RSK blocks oxLDL-induced IKKβ and NF-κB activation, VCAM-1 expression and monocyte adhesion. Finally, transgenic mice containing a kinase-dead mutation in FAK specifically in the endothelial cells show reduced RSK activity, decreased VCAM-1 expression and reduced macrophage accumulation in regions of early atherosclerosis. Taken together, our data elucidates a new mechanism whereby oxLDL-induced endothelial FAK signaling drives an ERK-RSK pathway to activate IKKβ and NF-κB signaling and proinflammatory gene expression.

Virulence analysis and two polymerase chain reaction–based assays were used to evaluate the population structure of Xanthomonas oryzae pv. oryzae (Xoo) from different elevations ranging from 150 to 2600 m in south‐west China. Among the 218 isolates of Xoo, 18 pathotypes were identified using six near‐isogenic rice lines, each containing a single resistance gene. Among them, pathotype 9 predominated in low and mid‐elevations was virulent to all resistance genes, including Xa2, Xa3, xa5, xa13, Xa14 and Xa18. However, pathotype 2 was predominant at high elevation and was virulent to Xa18 only. The 18 pathotypes were grouped into four clusters. Isolates belonging to cluster 1 were mainly found at high and mid‐elevations, while those of cluster 4 were mainly found at low elevations. There were significant trends of virulence of isolates from low to high with the elevation from high to low. The ERIC and J3 primers were used to screen the genomes of 218 isolates, and 56 molecular haplotypes were found. Multiple correspondence analyses revealed that 56 haplotypes were divided into four putative genetic lineages. Lineage 2 was the most frequently detected from 150 to 2600 m; it was clearly shown that isolates from high elevation with 80% is much more than from low and mid‐elevation in the lineage. It is intriguing that genetic variation of Xoo is restricted by physical geographical barriers of elevations. This is the first report on the relationship of pathotypic and genotypic diversity of Xoo at different elevations.

Focal adhesion kinase (FAK) is a cytoplasmic tyrosine kinase that controls cell motility and survival downstream of integrin receptors. FAK expression and activity are elevated during breast and ovarian cancer progression and this is associated with a poor clinical prognosis. Small molecule FAK inhibitors (FAK-I) block breast and ovarian tumor progression through a novel mechanism that is associated with the apoptosis under anchorage-deprived conditions. Metastatic cells can grow as anchorage-independent spheroids and we hypothesize that a spheroid micro-environment remains dependent on integrin- and FAK-associated signaling for survival. Here we show that intraperitoneal (ip) injection of murine ID8 ovarian carcinoma cells into mice, recovery of ascites-associated tumor cells (ID8ip) and growth ex vivo, yielded tumor cells with elevated levels of phosphorylated FAK (Y397 and Y576 phosphorylation), αvβ5 integrin, and osteopontin (OPN) matrix protein expression compared to parental ID8 cells. Analyses of paraffin-embedded breast and ovarian tumor sections revealed significantly higher pY397 FAK (p<0.05), β5 integrin (p<0.0001), and OPN expression (p<0.005) in stage II-III compared to stage I tumors. Treatment of ovarian ID8ip, human ovarian HEY carcinoma, or human MDA-MB-231 breast carcinoma cells with FAK-I inhibited cell growth, prevented FAK Y397 phosphorylation, reduced β5 integrin and OPN levels independent of effects on β1 or β3 integrins or changes in matrix proteins such as fibronectin. FAK-I impairs anchorage independent cell growth and orthotopic tumor growth but not growth of cells in plastic-adherent cell culture. Stable knockdown of either FAK or β5 integrin in HEY cells prevented anchorage-independent growth. Re-expression of wildtype or kinase-dead FAK within HEY cells verified the importance of FAK activity in promoting β5 integrin and OPN expression associated with enhanced tumor growth. Ongoing studies are focused on determining the molecular connections of FAK to the regulation of αvβ5 and OPN expression. Together, our studies support a novel role for a signaling loop involving OPN and αvβ5 integrin leading to FAK activation and reinforcement of OPN and β5 integrin expression within the spheroid and tumor micro-environment enhancing breast and ovarian cancer cell survival and tumor progression. Supported by Susan G. Komen for the Cure (KG111237) and NIH grant CA102310 Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1254. doi:1538-7445.AM2012-1254