XP showed significant noninferiority for PFS versus FP in the first-line treatment of AGC. XP can be considered an effective alternative to FP.

Urokinase-type plasminogen activator receptors (uPARs), up-regulated during tumor progression, associate with β1 integrins, localizing urokinase to sites of cell attachment. Binding of uPAR to the β-propeller of α3β1 empowers vitronectin adhesion by this integrin. How uPAR modifies other β1 integrins remains unknown. Using recombinant proteins, we found uPAR directly binds α5β1 and rather than blocking, renders fibronectin (Fn) binding by α5β1 Arg-Gly-Asp (RGD) resistant. This resulted from RGD-independent binding of α5β1–uPAR to Fn type III repeats 12–15 in addition to type III repeats 9–11 bound by α5β1. Suppression of endogenous uPAR by small interfering RNA in tumor cells promoted weaker, RGD-sensitive Fn adhesion and altered overall α5β1 conformation. A β1 peptide (res 224NLDSPEGGF232) that models near the known α-chain uPAR-binding region, or a β1-chain Ser227Ala point mutation, abrogated effects of uPAR on α5β1. Direct binding and regulation of α5β1 by uPAR implies a modified “bent” integrin conformation can function in an alternative activation state with this and possibly other cis-acting membrane ligands.

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This study aimed at assessing the efficacy and safety of biweekly oxaliplatin in combination with continuous infusional 5-fluorouracil and leucovorin (modified FOLFOX regimen) in patients with advanced small bowel adenocarcinoma (SBA). Thirty-three eligible patients with previously untreated SBA received 85 mg/m(2) of oxaliplatin intravenously over a 2-h period on day 1, together with 400 mg/m(2) of leucovorin over 2 h, followed by a 46-h infusion of 5-FU 2600 mg/m(2) every 2 weeks. All patients were evaluable for efficacy and toxicity. A median of nine cycles (range 3-18) was administered. The objective response rate was 48.5% [95% confidence interval (95% CI): 31-67%], with one complete response, 15 partial responses, 12 stable diseases, and five progressions. The median time to progression was 7.8 months (95% CI: 6.0-9.6) and the median overall survival was 15.2 months (95% CI: 11.0-19.4). Toxicity was fairly mild. Grade 3 toxicities included neutropenia (12.1%), thrombocytopenia (3.0%), nausea (6.1%), vomiting (3.0%), diarrhea (3.0%), peripheral neuropathy (9.1%), and fatigue (3.0%), and grade 4 toxicities occurred in none of the patients. The modified FOLFOX regimen is highly active and well tolerated as first-line chemotherapy for advanced SBA patients.

In addition to its thoroughly investigated role in bone formation, the osteoblast master transcription factor RUNX2 also promotes osteoclastogenesis and bone resorption. Here we demonstrate that 17β-estradiol (E2), which is known to attenuate bone turnover in vivo and RUNX2 activity in vitro, strongly inhibits RUNX2-mediated osteoblast-driven osteoclastogenesis in co-cultures. Towards deciphering the underlying mechanism, we induced premature expression of RUNX2 in primary murine pre-osteoblasts, which resulted in robust differentiation of co-cultured splenocytes into mature osteoclasts. This was attributable to RUNX2-mediated increase in RANKL secretion, determined by ELISA, as well as to RUNX2-mediated increase in RANKL association with the osteoblast membrane, demonstrated using confocal fluorescence microscopy. The increased association with the osteoblast membrane was recapitulated by transiently expressed GFP-RANKL. E2 abolished the RUNX2-mediated increase in membrane-associated RANKL and GFP-RANKL, as well as the concomitant osteoclastogenesis. RUNX2-mediated RANKL cellular redistribution was attributable in part to a decrease in Opg expression, but E2 did not influence Opg expression either in the presence or absence of RUNX2. Diminution of RUNX2-mediated osteoclastogenesis by E2 occurred regardless of whether the pre-osteoclasts were derived from wild type or estrogen receptor alpha (ERα)-knockout mice, suggesting that activated ERα inhibited osteoblast-driven osteoclastogenesis by acting in osteoblasts, possibly targeting RUNX2. Furthermore, the selective ER modulators (SERMs) tamoxifen and raloxifene mimicked E2 in abrogating the stimulatory effect of osteoblastic RUNX2 on osteoclast differentiation in the co-culture assay. Thus, E2 antagonizes RUNX2-mediated RANKL trafficking and subsequent osteoclastogenesis. Targeting RUNX2 and/or downstream mechanisms that regulate RANKL trafficking may lead to the development of improved SERMs and possibly non-hormonal therapeutic approaches to high turnover bone disease.

7548 Background: Apatinib is an oral, small molecular tyrosine-kinase inhibitor (TKI) targeting vascular endothelial growth factor receptor (VEGFR). Phase II study has showed that apatinib significantly improved the outcome of patients with advanced or metastatic gastric cancer (Li J, et al. ASCO 2011). The primary object of this study is to determine whether apatinib can improve progression free survival (PFS) compared with placebo in patients with advanced non-squamous NSCLC who failed two lines of treatment. Methods: This study recruited histologically diagnosed advanced non-squamous NSCLC patients who failed more than two lines of treatment including EGFR TKIs. Other eligible criteria included ECOG ≤1, adequate organ function and no prior exposure to VEGFR-TKI. The patients were randomized to receive apatinib at a dose of 750 mg or placebo (at allocation ratio of 2:1) orally once daily until the disease progression or unacceptable toxicity. Results: 135 patients (90 in apatinib arm, 45 in placebo arm) were included at 20 centers in China until Aug 2011. Median PFS was 4.7 months for apatinib group versus 1.9 months for placebo group, hazard ratio (HR) was 0.278 (95% CI 0.170, 0.455) (p<0.0001). The response rate (RR) and disease control rate (DCR) were also significantly better in study arm (12.2% and 68.9%) than in placebo arm (0% and 24.4%)(P=0.0158 and P<0.0001). The most frequently observed AEs were hypertension, proteinuria, and hand-foot syndrome (HFS). These AEs were generally mild or moderate in severity and were manageable. Conclusions: This randomized phase II trial shows that apatinib has substantial clinical activity without significant additional toxicity in patients with advanced non-squamous and non-small cell lung cancer. Continued investigation of apatinib is warranted in future clinical studies.

The efficacy of glucocorticoids (GCs) in treating a wide range of autoimmune and inflammatory conditions is blemished by severe side effects, including osteoporosis. The chief mechanism leading to GC-induced osteoporosis is inhibition of bone formation, but the role of RUNX2, a master regulator of osteoblast differentiation and bone formation, has not been well studied. We assessed effects of the synthetic GC dexamethasone (dex) on transcription of RUNX2-stimulated genes during the differentiation of mesenchymal pluripotent cells into osteoblasts. Dex inhibited a RUNX2 reporter gene and attenuated locus-dependently RUNX2-driven expression of several endogenous target genes. The anti-RUNX2 activity of dex was not attributable to decreased RUNX2 expression, but rather to physical interaction between RUNX2 and the GC receptor (GR), demonstrated by co-immunoprecipitation assays and co-immunofluorescence imaging. Investigation of the RUNX2/GR interaction may lead to the development of bone-sparing GC treatment modalities for the management of autoimmune and inflammatory diseases.

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