Economics of Management Zone Delineation in Cotton Precision Agriculture

This paper develops a management zone delineation procedure based on a spatial statistics approach and evaluates its economic impact for the case of Texas cotton production. With the use of an optimization model that utilizes a yield response function estimated through spatial econometric methods, we found that applying variable N rates based on the management zones delineated would result in higher cotton yields and higher net returns, above Nitrogen cost, relative to uniformly applying a single N rate for the whole field. In addition, a variable rate N application using the delineated management zones produced higher net returns, above Nitrogen cost, relative to a variable N rate system where the zones are based solely on landscape position. This is indicative of the potential economic value of using a spatial statistics approach to management zone delineation.Management Zones, Exploratory Spatial Data Analysis, Site-Specific Nitrogen Management, Cotton Precision Agriculture., Crop Production/Industries, Q1, Q16,

Economics of Management Zone Delineation in Cotton Precision Agriculture

This paper develops a management zone delineation procedure based on a spatial clustering approach and evaluates its economic impact for the case of Texas cotton production. The results show that there is potential economic value in using a spatial approach to management zone delineation, but its value critically depends on the cost of collecting soil test information needed to delineate those zones.Management Zones, Exploratory Spatial Data Analysis, Site-Specific Nitrogen Management, Cotton Precision Agriculture, Crop Production/Industries, Q12,

Un análisis económico de la aproximación estadística para el establecimiento de zonas de manejo en agricultura de precisión: caso de algodón en Texas

Este artículo desarrolla un proceso para el establecimiento de zonas de manejo basado en una aproximación estadística espacial y evalúa su impacto económico para el caso de producción de algodón en Texas. Con el uso de un modelo de optimización que utiliza funciones de producción estimadas tomando en cuenta la autocorrelación espacial mediante métodos de econometría espacial, se encontró que al aplicar nitrógeno a una tasa variable, basada en las zonas de manejo delineadas, se obtienen rendimientos de algodón más altos comparados con los rendimientos obtenidos al aplicar una tasa uniforme de nitrógeno sobre toda la unidad productiva. Así mismo, se encontró que las aplicaciones de N a una tasa variable generan ingresos netos superiores comparados con los ingresos netos generados por la aplicación uniforme de N a la tasa agronómica sugerida, y retornos inferiores comparados con la aplicación uniforme derivada del óptimo económico. Adicionalmente, se encontró que niveles promedios de nitrógeno más bajos son requeridos con las aplicaciones de nitrógeno a una tasa variable para alcanzar rendimientos más altos comparados con la aplicación uniforme de nitrógeno.Zonas de manejo, análisis espacial exploratorio de datos, manejo espacial específico de nitrógeno, agricultura de precisión con aplicaciones en algodón.

Crucial Role for Early Growth Response-1 in the Transcriptional Regulation of miR-20b in Breast Cancer

Transcriptional regulation of miRNAs that control the pathogenesis of breast cancer remains largely unknown. Here, we showed that ionizing radiation, a known breast carcinogen, triggered the differential expression of miR-20b in mammary tissues. We identified several GC-rich consensus binding motifs for the zinc finger transcription factor early growth response-1 (EGR1) in miR-20b promoter. miR-20b was upregulated by IR and its upregulation correlated with EGR1 expression in the breast cancer cell line HCC1806. Therefore, we used HCC1806 cells as a model system to explore the role of EGR1 in miR-20b transcription. siRNA knockdown of EGR1 attenuated miR-20b expression. Luciferase assays showed that whereas EGR1 stimulated luciferase activity driven by the wild-type miR-20b promoter, this induction was abolished in the mutant miR-20 promoter construct. We noted significant enrichment of EGR1 at miR-20b promoter in HCC1806 cells compared with normal human mammary epithelial cells. Suppression of miR-20b significantly inhibited HCC1806 cell proliferation and migration, and led to G 0/G 1 and S phase arrest. In vitro RNA-pull down assays indicated that miR-20b targets numerous tumor suppressors, including PTEN and BRCA1, which were downregulated in HCC1806. Conversely, suppression of miR-20b increased PTEN and BRCA1 levels. Moreover, immunohistochemical and FISH analyses showed that the miR-20b expression correlated significantly with EGR1 levels in breast cancer tissues. Our findings thus demonstrate for the first time that EGR1 is a key player in the transcriptional control of miR-20b, and miR-20b may in turn function as an oncogene by contributing to breast tumorigenesis via tumor suppressor targeting

GPR56 Plays Varying Roles in Endogenous Cancer Progression

2011 March 29GPR56, a non-classical adhesion receptor, was previously reported to suppress tumor growth and metastasis in xenograft models using human melanoma cell lines. To understand whether GPR56 plays similar roles in the development of endogenous tumors, we analyzed cancer progression in Gpr56 [superscript −/−] mice using a variety of transgenic cancer models. Our results showed that GPR56 suppressed prostate cancer progression in the TRAMP model on a mixed genetic background, similar to its roles in progression of melanoma xenografts. However, its roles in other cancer types appeared to be complex. It had marginal effects on tumor onset of mammary tumors in the MMTV–PyMT model, but had no effects on subsequent tumor progression in either the MMTV–PyMT mice or the melanoma model, Ink4a/Arf [superscript −/−] tyr-Hras. These results indicate diverse roles of GPR56 in cancer progression and provide the first genetic evidence for the involvement of an adhesion GPCR in endogenous cancer development

Role of aberrant PI3K pathway activation in gallbladder tumorigenesis

The PI3K/AKT pathway governs a plethora of cellular processes, including cell growth, proliferation, and metabolism, in response to growth factors and cytokines. By acting as a unique lipid phosphatase converting phosphatidylinositol-3,4,5,-trisphosphate (PIP3) to phosphatidylinositol-4,5,-bisphosphate (PIP2), phosphatase and tensin homolog (PTEN) acts as the major cellular suppressor of PI3K signaling and AKT activation. Recently, PI3K mutations and loss/mutation of PTEN have been characterized in human gallbladder tumors; whether aberrant PTEN/PI3K pathway plays a causal role in gallbladder carcinogenesis, however, remains unknown. Herein we show that in mice, deregulation of PI3K/AKT signaling is sufficient to transform gallbladder epithelial cells and trigger fully penetrant, highly proliferative gallbladder tumors characterized by high levels of phospho-AKT. Histopathologically, these mouse tumors faithfully resemble human adenomatous gallbladder lesions. The identification of PI3K pathway deregulation as both an early event in the neoplastic transformation of the gallbladder epithelium and a main mechanism of tumor growth in Pten heterozygous and Pten mutant mouse models provides a new framework for studying in vivo the efficacy of target therapies directed against the PI3K pathway, as advanced metastatic tumors are often addicted to “trunkular” mutations

Induction of Histiocytic Sarcoma in Mouse Skeletal Muscle

Myeloid sarcomas are extramedullary accumulations of immature myeloid cells that may present with or without evidence of pathologic involvement of the bone marrow or peripheral blood, and often coincide with or precede a diagnosis of acute myeloid leukemia (AML). A dearth of experimental models has hampered the study of myeloid sarcomas and led us to establish a new system in which tumor induction can be evaluated in an easily accessible non-hematopoietic tissue compartment. Using ex-vivo transduction of oncogenic Kras(G12V) into p16/p19−/− bone marrow cells, we generated transplantable leukemia-initiating cells that rapidly induced tumor formation in the skeletal muscle of immunocompromised NOD.SCID mice. In this model, murine histiocytic sarcomas, equivalent to human myeloid sarcomas, emerged at the injection site 30–50 days after cell implantation and consisted of tightly packed monotypic cells that were CD48+, CD47+ and Mac1+, with low or absent expression of other hematopoietic lineage markers. Tumor cells also infiltrated the bone marrow, spleen and other non-hematopoietic organs of tumor-bearing animals, leading to systemic illness (leukemia) within two weeks of tumor detection. P16/p19−/−; Kras(G12V) myeloid sarcomas were multi-clonal, with dominant clones selected during secondary transplantation. The systemic leukemic phenotypes exhibited by histiocytic sarcoma-bearing mice were nearly identical to those of animals in which leukemia was introduced by intravenous transplantation of the same donor cells. Moreover, murine histiocytic sarcoma could be similarly induced by intramuscular injection of MLL-AF9 leukemia cells. This study establishes a novel, transplantable model of murine histiocytic/myeloid sarcoma that recapitulates the natural progression of these malignancies to systemic disease and indicates a cell autonomous leukemogenic mechanism.Stem Cell and Regenerative Biolog

The Oncogenic Lung Cancer Fusion Kinase CD74-ROS Activates a Novel Invasiveness Pathway through E-Syt1 Phosphorylation

Patients with lung cancer often present with metastatic disease and therefore have a very poor prognosis. The recent discovery of several novel ROS receptor tyrosine kinase molecular alterations in non–small cell lung cancer (NSCLC) presents a therapeutic opportunity for the development of new targeted treatment strategies. Here, we report that the NSCLC-derived fusion CD74-ROS, which accounts for 30% of all ROS fusion kinases in NSCLC, is an active and oncogenic tyrosine kinase. We found that CD74-ROS–expressing cells were highly invasive in vitro and metastatic in vivo. Pharmacologic inhibition of CD74-ROS kinase activity reversed its transforming capacity by attenuating downstream signaling networks. Using quantitative phosphoproteomics, we uncovered a mechanism by which CD74-ROS activates a novel pathway driving cell invasion. Expression of CD74-ROS resulted in the phosphorylation of the extended synaptotagmin-like protein E-Syt1. Elimination of E-Syt1 expression drastically reduced invasiveness both in vitro and in vivo without modifying the oncogenic activity of CD74-ROS. Furthermore, expression of CD74-ROS in noninvasive NSCLC cell lines readily conferred invasive properties that paralleled the acquisition of E-Syt1 phosphorylation. Taken together, our findings indicate that E-Syt1 is a mediator of cancer cell invasion and molecularly define ROS fusion kinases as therapeutic targets in the treatment of NSCLC.National Institutes of Health (U.S.) (Grant NCI U01 CA141556

Genotype Directed Therapy in Murine Mismatch Repair Deficient Tumors

The PI3K/AKT/mTOR pathway has frequently been found activated in human tumors. We show that in addition to Wnt signaling dysfunction, the PI3K/AKT/mTOR pathway is often upregulated in mouse Msh2−/− initiated intestinal tumors. NVP-BEZ235 is a dual PI3K/mTOR inhibitor toxic to many cancer cell lines and currently involved in clinical trials. We have treated two mouse models involving Msh2 that develop small intestinal and/or colonic tumors with NVP-BEZ235, and a subset of animals with NVP-BEZ235 and MEK inhibitor ADZ4266. The disease phenotype has been followed with pathology, 18F FDG PET imaging, and endoscopy. Intestinal adenocarcinomas are significantly decreased in multiplicity by both drug regimens. The majority of tumors treated with combined therapy regress significantly, while a small number of highly progressed tumors persist. We have examined PTEN, AKT, MEK 1&2, MAPK, S6K, mTOR, PDPK1, and Cyclin D1 and find variable alterations that include downregulation of PTEN, upregulation of AKT and changes in its phosphorylated forms, upregulation of pMEK 1&2, p42p44MAPK, pS6K, and Cyclin D1. Apoptosis has been found intact in some tumors and not in others. Our data indicate that NVP-BEZ235 alone and in combination with ADZ4266 are effective in treating a proportion of colorectal cancers, but that highly progressed resistant tumors grow in the presence of the drugs. Pathways upregulated in some resistant tumors also include PDPK1, suggesting that metabolic inhibitors may also be useful in treating these tumors