Preface Focal adhesion kinase (FAK) is a cytoplasmic protein tyrosine kinase that is over-expressed and activated in several advanced-stage solid cancers. FAK promotes tumor progression and metastasis through effects on cancer cells, as well as stromal cells of the tumor microenvironment. FAK’s kinase-dependent and –independent functions control cell movement, invasion, survival, gene expression, and cancer stem cell self-renewal. Small molecule FAK inhibitors decrease tumor growth and metastasis in several preclinical models and possess initial clinical activity in patients with limited adverse events. We discuss FAK signaling effects on both tumor and stromal cell biology that provide rationale and support for future therapeutic opportunities.

SUMMARY Endothelial cells (ECs) form cell-cell adhesive junctional structures maintaining vascular integrity. This barrier is dynamically regulated by vascular endothelial growth factor (VEGF) receptor signaling. We created an inducible knockin mouse model to study the contribution of the integrin-associated focal adhesion tyrosine kinase (FAK) signaling on vascular function. Here we show that genetic or pharmacological FAK inhibition in ECs prevents VEGF-stimulated permeability downstream of VEGF receptor or Src tyrosine kinase activation in vivo. VEGF promotes tension-independent FAK activation, rapid FAK localization to cell-cell junctions, binding of the FAK FERM domain to the vascular endothelial cadherin (VE-cadherin) cytoplasmic tail, and direct FAK phosphorylation of β-catenin at tyrosine-142 (Y142) facilitating VE-cadherin-β-catenin dissociation and EC junctional breakdown. Kinase inhibited FAK is in a closed conformation that prevents VE-cadherin association and limits VEGF-stimulated β-catenin Y142 phosphorylation. Our studies establish a role for FAK as an essential signaling switch within ECs regulating adherens junction dynamics.

Endothelial cell focal adhesion kinase is a key intermediate between c-Src and the regulation of endothelial cell barrier function in the control of tumor metastasis.

Recurrence and spread of ovarian cancer is the 5th leading cause of death for women in the United States. Focal adhesion kinase (FAK) is a cytoplasmic protein-tyrosine kinase located on chromosome 8q24.3 (gene is Ptk2), a site commonly amplified in serous ovarian cancer. Elevated FAK mRNA levels in serous ovarian carcinoma are associated with decreased (logrank P = 0.0007, hazard ratio 1.43) patient overall survival, but how FAK functions in tumor progression remains undefined. We have isolated aggressive ovarian carcinoma cells termed ID8-IP after intraperitoneal (IP) growth of murine ID8 cells in C57Bl6 mice. Upon orthotopic implantation within the periovarian bursa space, ID8-IP cells exhibit greater tumor growth, local and distant metastasis, and elevated numbers of ascites-associated cells compared to parental ID8 cells. ID8-IP cells exhibit enhanced growth under non-adherent conditions with elevated FAK and c-Src tyrosine kinase activation compared to parental ID8 cells. In vitro, the small molecule FAK inhibitor (Pfizer, PF562,271, PF-271) at 0.1 uM selectively prevented anchorage-independent ID8-IP cell growth with the inhibition of FAK tyrosine (Y)397 but not c-Src Y416 phosphorylation. Oral PF-271 administration (30 mg/kg, twice daily) blocked FAK but not c-Src tyrosine phosphorylation in ID8-IP tumors. This was associated with decreased tumor size, prevention of peritoneal metastasis, reduced tumor-associated endothelial cell number, and increased tumor cell-associated apoptosis. FAK knockdown and re-expression assays showed that FAK activity selectively promoted anchorage-independent ID8-IP cell survival. These results support the continued evaluation of FAK inhibitors as a promising clinical treatment for ovarian cancer.

Protease inhibitors have been proposed as potential control molecules that could be engineered into potato plants for developing crops resistant to the Colorado potato beetle, Leptinotarsa decemlineata, a major pest of potato and other Solanaceae. In this study, we examined the effects of feeding young female beetles with foliage from a cultivar of the "Kennebec" potato line (K52) transformed with a gene encoding oryzacystatin I (OCI), a specific cysteine proteinase inhibitor with proven activity against cathepsin H-like enzymes of larvae and adults of the potato beetle. To evaluate the insect's performance, we collected data over a 16-d postemergence period on survival, diapause incidence, foliage consumption, weight gain, and oviposition of females. Tested individuals were fed untransformed (control) and OCI-transformed foliage at two stages of potato leaf differentiation, corresponding to "low" and "high" levels of OCI expression in leaves of K52. The OCI-expressing foliage did not affect female survival (close to 100%), incidence of diapause (15-30%), relative growth rate (RGR) during postemergence growth (5-9% d(-1)) or maximum weight reached (140-160 mg). Neither did it affect female reproductive fitness as measured by preoviposition time (8-9 d), 16-d fecundity (220-290 eggs), or egg eclosion incidence (86-91%). However, nutritional stress to females feeding on OCI foliage was evident, as reflected in their lower efficiency of conversion of ingested foliage (ECI) during postemergence growth, increased foliage consumed per egg laid (up to 119% more), and adaptation of their digestive proteolytic system to the inhibitory effect of OCI. Interestingly, beetles fed foliage expressing the highest level of OCI reacted rapidly to the presence of OCI by producing OCI-insensitive proteases, and exhibiting strong hypertrophic behavior by ingestion of 2.4-2.5 times more OCI rich foliage apparently as a compensatory response for nutritional stress due to the protease inhibitor in their diet.

inhibits Natural Killer and γδ T cell cytotoxicity triggered by NKR and TCR through a cAMPmediated PKA type I-dependent signaling. Biochemical Pharmacology, Elsevier, 2010, 80 (6) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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Follicular lymphomas (FLs) account for 35–40% of all adult lymphomas. Treatment typically involves chemotherapy combined with the anti-CD20 monoclonal antibody (MAb) rituximab (RTX). The development of the type II anti-CD20 MAb obinutuzumab (GA101) aims to further improve treatment. Here, using FL cells we show that RTX and GA101 display a similar activity on RL cells cultured in 2D. However, 2D culture cannot mimic tumor spatial organization and conventional 2D models may not reflect the effects of antibodies as they occur in vivo. Thus, we created a non-Hodgkin's lymphoma (NHL) 3D culture system, termed multicellular aggregates of lymphoma cells (MALC), and used it to compare RTX and GA101 activity. Our results show that both antibodies display greater activity towards FL cells in 3D culture compared with 2D culture. Moreover, we observed that in the 3D model GA101 was more effective than RTX both in inhibiting MALC growth through induction of (lysosomal) cell death and senescence and in inhibiting intracellular signaling pathways, such as mammalian target of rapamycin, Akt, PLCgamma (Phospholipase C gamma) and Syk. Altogether, our study demonstrates that spatial organization strongly influences the response to antibody treatment, supporting the use of 3D models for the testing of therapeutic agents in NHL.