The approaching era of the tumor suppressor genes

Genes that can inhibit the expression of the tumorigenic phenotype have been detected by the fusion of normal and malignant cells, the phenotypic reversion of in vitro transformants, the induction of terminal differentiation of malignant cell lineages, the loss of "recessive cancer genes," the discovery of regulatory sequences in the immediate vicinity of certain oncogenes, and the inhibition of tumor growth by normal cell products. Such tumor suppressor genes will probably turn out to be as, if not more, diversified as the oncogenes. Consideration of both kinds of genes may reveal common or interrelated functional properties.     

The control of the metabolic switch in cancers by oncogenes and tumor suppressor genes

Cells from some tumors use an altered metabolic pattern compared with that of normal differentiated adult cells in the body. Tumor cells take up much more glucose and mainly process it through aerobic glycolysis, producing large quantities of secreted lactate with a lower use of oxidative phosphorylation that would generate more adenosine triphosphate (ATP), water, and carbon dioxide. This is the Warburg effect, which provides substrates for cell growth and division and free energy (ATP) from enhanced glucose use. This metabolic switch places the emphasis on producing intermediates for cell growth and division, and it is regulated by both oncogenes and tumor suppressor genes in a number of key cancer-producing pathways. Blocking these metabolic pathways or restoring these altered pathways could lead to a new approach in cancer treatments.     

Piecing together the biggest puzzle of all

In this month's essay, the last in the Pathways of Discovery series, Martin J. Rees celebrates the way astronomers and cosmologists have systematically uncovered the biography of the universe. Rife with neutron stars, black holes, and multiple universes that emerge from quantum fluctuation, it's a story as grand as it is strange.     

Structure of the receptor for insulin-like growth factor II: the puzzle amplified

The insulin-like growth factor II (IGF-II) is a polypeptide hormone with structural homologies to insulin and insulin-like growth factor I (IGF-I). In contrast to these other hormones, the in vivo function of IGF-II is not known. Although IGF-II can stimulate a broad range of biological responses in isolated cells, these responses have usually been found to be mediated by the insulin and IGF-I receptors. Recently, the receptor for IGF-II was found to also be the receptor for mannose-6-phosphate. Since this latter receptor has been implicated in targeting of lysosomal enzymes, the question is now raised of whether the same protein can also mediate metabolic responses to IGF-II.     

Getting to better water quality outcomes: the promise and challenge of the citizen effect

Agriculture is a major cause of non-point source water pollution in the Midwest. Excessive nitrate, phosphorous, and sediment levels degrade the Mississippi River and Gulf of Mexico. In this research we ask, to what extent can citizen involvement help solve the problem of non-point source pollution. Does connecting farmers to farmers and to other community members make a difference in moving beyond the status quo? To answer these questions we examine the satisfaction level of Iowa farmers and landowners with their current conservation measures as a proxy for willingness to change. A survey of 360 conservation minded farmers obtained from a random sample of 75 HUC (Hydrologic Unit Code) 12 Iowa watersheds reveals that 27% of the variance among farmers’ perception of adequacy of their conservation practices is explained by a combination of beliefs about the seriousness of water pollution, personal, civic, and expert connections. The more farmers talk with other farmers the more likely they are satisfied with their conservation efforts. However, the more frequently farmers talk to friends and neighbors that don’t farm, the more likely they are to not be satisfied with their conservation efforts. Further, the more social organizations farmers belong to—e.g., more non-farmers they interact with in a group setting—the more likely they are to be dissatisfied with their level of effort being adequate to protect local water bodies. These findings suggest the personal and civic connections among farmers and communities are important in explaining perceptions of how adequate conservation measures are. These perceptions have implications for farmers’ willingness to go beyond current actions and more actively engage in solving local watershed problems and explain why they may not currently be engaged in additional actions.     

Livestock breeding for the 21st century: the promise of the editing revolution

In recent years there has been a veritable explosion in the use of genome editors to create site-specific changes, both in vitro and in vivo, to the genomes of a multitude of species for both basic research and biotechnology. Livestock, which form a vital component of most societies, are no exception. While selective breeding has been hugely successful at enhancing some production traits, the rate of progress is often slow and is limited to variants that exist within the breeding population. Genome editing provides the potential to move traits between breeds, in a single generation, with no impact on existing productivity or to develop de novo phenotypes that tackle intractable issues such as disease. As such, genome editors provide huge potential for ongoing livestock development programs in light of increased demand and disease challenge. This review will highlight some of the more notable agricultural applications of this technology in livestock.