The Tripartite Rhizobacteria-AM Fungal-Host Plant Relationship in Winter Wheat: Impact of Multi-Species Inoculation, Tillage Regime and Naturally Occurring Rhizobacteria Species.

Soils and plant root rhizospheres have diverse microorganism profiles. Components of this naturally occurring microbiome, arbuscular mycorrhizal (AM) fungi and plant growth promoting rhizobacteria (PGPR), may be beneficial to plant growth. Supplementary application to host plants of AM fungi and PGPR either as single species or multiple species inoculants has the potential to enhance this symbiotic relationship further. Single species interactions have been described; the nature of multi-species tripartite relationships between AM fungi, PGPR and the host plant require further scrutiny. The impact of select Bacilli spp. rhizobacteria and the AM fungus Rhizophagus intraradices as both single and combined inoculations (PGPR[i] and AMF[i]) within field extracted arable soils of two tillage treatments, conventional soil inversion (CT) and zero tillage (ZT) at winter wheat growth stages GS30 and GS39 have been conducted. The naturally occurring soil borne species (PGPR[s] and AMF[s]) have been determined by qPCR analysis. Significant differences (p < 0.05) were evident between inocula treatments and the method of seedbed preparation. A positive impact on wheat plant growth was noted for B. amyloliquefaciens applied as both a single inoculant (PGPR[i]) and in combination with R. intraradices (PGPR[i] + AMF[i]); however, the two treatments did not differ significantly from each other. The findings are discussed in the context of the inocula applied and the naturally occurring soil borne PGPR[s] present in the field extracted soil under each method of tillage.

Species-Specific Interactions of Bacillus Innocula and Arbuscular Mycorrhizal Fungi Symbiosis with Winter Wheat.

Arbuscular mycorrhizal (AM) fungi establish close interactions with host plants, an estimated 80% of vascular plant species. The host plant receives additional soil bound nutrients that would otherwise not be available. Other components of the microbiome, such as rhizobacteria, may influence interactions between AM fungi and the host plant. Within a commercial arable crop selected rhizobacteria in combination with AM fungi may benefit crop yields. The precise nature of interactions between rhizobacteria and AM fungi in a symbiotic relationship overall requires greater understanding. The present study aims to assess this relationship by quantifying: (1) AM fungal intracellular root structures (arbuscules) and soil glomalin as an indicator of AM fungal growth; and (2) root length and tiller number as a measure of crop growth, in response to inoculation with one of three species of Bacillus: B. amyloliquefaciences, B. pumilis, or B. subtilis. The influence of soil management, conventional (CT) or zero tillage (ZT) was a further variable evaluated. A significant (p < 0.0001) species-specific impact on the number of quantifiable AM fungal arbuscules was observed. The inoculation of winter wheat (Triticum aestivum) with B. amyloliquefaciences had a positive impact on AM fungal symbiosis, as indicated by an average of 3226 arbuscules per centimetre of root tissue. Bacillus subtilis increased root length significantly (p < 0.01) but decreased fungal symbiosis (p < 0.01). The inoculation of field soils altered the concentration of glomalin, an indicator of AM fungal growth, significantly (p < 0.00001) for each tillage treatment. The greatest increase was associated with B. amyloliquefaciences for both CT (p < 0.0001) and ZT (p < 0.00001). Bacillus subtilis reduced measured glomalin significantly in both tillage treatments (p < 0.0001 and p < 0.00001 for CT and ZT respectively). The interaction between rhizobacteria and AM fungi is variable, being beneficial or detrimental depending on species. This relationship was evident in both tillage treatments and has important implications for maximizing symbiosis in the crop plant-microbiome present in agricultural systems.

A comparison of methodologies for the staining and quantification of intracellular components of arbuscular mycorrhizal fungi in the root cortex of two varieties of winter wheat.

Arbuscular mycorrhizal (AM) fungi are one of the most common fungal organisms to exist in symbiosis with terrestrial plants, facilitating the growth and maintenance of arable crops. Wheat has been studied extensively for AM fungal symbiosis using the carcinogen trypan blue as the identifying stain for fungal components, namely arbuscles, vesicles and hyphal structures. The present study uses Sheaffer blue ink with a lower risk as an alternative to this carcinogenic stain. Justification for this is determined by stained wheat root sections (n=120), with statistically significant increases in the observed abundance of intracellular root cortical fungal structures stained with Sheaffer blue ink compared to trypan blue for both Zulu (P=0.003) and Siskin (P=0.0003) varieties of winter wheat. This new alternative combines an improved quantification of intracellular fungal components with a lower hazard risk at a lower cost.

Changes in Bone Turnover Marker Levels and Clinical Outcomes in Patients with Advanced Cancer and Bone Metastases Treated with Bone Antiresorptive Agents.

PURPOSE: Bone antiresorptive agents can significantly reduce bone turnover markers (BTM) in patients with advanced cancer. We evaluated association of changes in BTMs with overall survival (OS), disease progression (DP), and disease progression in bone (DPB) in patients with advanced cancer and bone metastases following denosumab or zoledronic acid treatment. EXPERIMENTAL DESIGN: This is an integrated analysis of patient-level data from three identically designed, blinded, phase III trials with patients randomized to subcutaneous denosumab or intravenous zoledronic acid. Levels of the BTMs urinary N-telopeptide (uNTx) and serum bone-specific alkaline phosphatase (sBSAP) measured at study entry and month 3 were analyzed. OS, DP, and DPB were compared in patients with BTMs ≥ median versus < median based on month 3 assessments. RESULTS: uNTx levels ≥ the median of 10.0 nmol/mmol at month 3 were associated with significantly reduced OS compared with levels < median (HR for death, 1.85; P < 0.0001). sBSAP levels ≥ median of 12.6 ng/mL were associated with significantly reduced OS compared with levels < median (HR, 2.44; P < 0.0001). uNTx and sBSAP levels ≥ median at month 3 were associated with significantly greater risk of DP (HR, 1.31; P < 0.0001 and HR, 1.71; P < 0.0001, respectively) and DPB (HR, 1.11; P = 0.0407 and HR, 1.27; P < 0.0001, respectively). CONCLUSIONS: BTM levels ≥ median after 3 months of bone antiresorptive treatment were associated with reduced OS and increased risk of DP and DPB. Assessment of uNTx and sBSAP levels after bone antiresorptive therapy may add to identification of patients at risk for worse clinical outcomes. Clin Cancer Res; 22(23); 5713-21. ©2016 AACR.

Motesanib with or without panitumumab plus FOLFIRI or FOLFOX for the treatment of metastatic colorectal cancer.

PURPOSE: This study assessed the safety, efficacy, and pharmacokinetics of motesanib, a multitargeted small molecule angiogenesis inhibitor, with and without panitumumab, in combination with FOLFIRI or FOLFOX in patients with metastatic colorectal cancer (mCRC). METHODS: This open-label, phase 1b, two-part, multicenter study in patients with mCRC and ≤1 prior treatment evaluated escalating doses (50, 75, 100, or 125 mg QD, 75 mg BID) of motesanib with panitumumab and chemotherapy (Part 1) and the target dose of motesanib with chemotherapy (Part 2). RESULTS: At 17 sites in the USA and Australia, 119 patients were enrolled between December 2004 and February 2010. In Part 1 [motesanib plus panitumumab/FOLFIRI (n = 36) or plus panitumumab/FOLFOX (n = 17)], all motesanib doses tested were tolerated and 125 mg QD was deemed the target dose. Following toxicity results for combination therapy in other trials, panitumumab was withdrawn from the study. Part 2 evaluated motesanib 125 mg with chemotherapy [FOLFIRI (n = 37); FOLFOX (n = 29)]. The primary endpoint, objective response rate in patients with measurable disease by RECIST, was 20 % overall and was higher among patients receiving first-line (27 % overall; FOLFOX, 24 %; FOLFIRI, 27 %) compared with second-line therapy (14 % overall; FOLFOX, 0 %; FOLFIRI, 20 %). The most common adverse events were diarrhea, nausea, fatigue, and hypertension. We observed a low rate of cholecystitis [3 of 119 (2.5 %)], a known adverse event of motesanib and other small molecule VEGF inhibitors. CONCLUSIONS: Motesanib 125 mg QD in combination with FOLFIRI or FOLFOX chemotherapy was tolerated and demonstrated modest efficacy in first-/second-line mCRC.

Anti-angiopoietin therapy with trebananib for recurrent ovarian cancer (TRINOVA-1): a randomised, multicentre, double-blind, placebo-controlled phase 3 trial.

BACKGROUND: Angiogenesis is a valid target in the treatment of epithelial ovarian cancer. Trebananib inhibits the binding of angiopoietins 1 and 2 to the Tie2 receptor, and thereby inhibits angiogenesis. We aimed to assess whether the addition of trebananib to single-agent weekly paclitaxel in patients with recurrent epithelial ovarian cancer improved progression-free survival. METHODS: For this randomised, double-blind phase 3 study undertaken between Nov 10, 2010, and Nov 19, 2012, we enrolled women with recurrent epithelial ovarian cancer from 32 countries. Patient eligibility criteria included having been treated with three or fewer previous regimens, and a platinum-free interval of less than 12 months. We enrolled patients with a computerised interactive voice response system, and patients were randomly assigned using a permuted block method (block size of four) in a 1:1 ratio to receive weekly intravenous paclitaxel (80 mg/m(2)) plus either weekly masked intravenous placebo or trebananib (15 mg/kg). Patients were stratified on the basis of platinum-free interval (≥0 and ≤6 months vs >6 and ≤12 months), presence or absence of measurable disease, and region (North America, western Europe and Australia, or rest of world). The sponsor, investigators, site staff, and patients were masked to the treatment assignment. The primary endpoint was progression-free survival assessed in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, NCT01204749, and is no longer accruing patients. FINDINGS: 919 patients were enrolled, of whom 461 were randomly assigned to the trebananib group and 458 to the placebo group. Median progression-free survival was significantly longer in the trebananib group than in the placebo group (7·2 months [5·8-7·4] vs 5·4 months [95% CI 4·3-5·5], respectively, hazard ratio 0·66, 95% CI 0·57-0·77, p<0·0001). Incidence of grade 3 or higher adverse events was similar between treatment groups (244 [54%] of 452 patients in the placebo group vs 258 [56%] of 461 patients in the trebananib group). Trebananib was associated with more adverse event-related treatment discontinuations than was placebo (77 [17%] patients vs 27 [6%], respectively) and higher incidences of oedema (294 [64%] patients had any-grade oedema in the trebananib group vs 127 [28%] patients in the placebo group). Grade 3 or higher adverse events included ascites (34 [8%] in the placebo group vs 52 [11%] in the trebananib group), neutropenia (40 [9%] vs 26 [6%]), and abdominal pain (21 [5%] vs 22 [5%]). We recorded serious adverse events in 125 (28%) patients in the placebo group and 159 (34%) patients in the trebananib group. There was a difference of 2% or less in class-specific adverse events associated with anti-VEGF therapy (hypertension, proteinuria, wound-healing complications, thrombotic events, gastrointestinal perforations), except bleeding, which was more common in the placebo group than in the trebananib group (75 [17%] vs 46 [10%]). INTERPRETATION: Inhibition of angiopoietins 1 and 2 with trebananib provided a clinically meaningful prolongation in progression-free survival. This non-VEGF anti-angiogenesis option for women with recurrent epithelial ovarian cancer should be investigated in other settings and in combination with additional agents. Although oedema was increased, typical anti-VEGF associated adverse events were not prominent. FUNDING: Amgen.