Growth factor receptors (GFRs) are often aberrantly expressed in tumor cells, and altered GFR expression and activity contribute to the pathogenesis of many types of cancer. A variety of mechanisms have been identified that result in enhanced GFR expression and activity in cancer cells. Defects in the pathways responsible for GFR internalization and intracellular trafficking are likely to be involved in altered GFR expression in a variety of cancers. The roles of GFR trafficking pathways in the regulation of GFR expression, in the pathogenesis of tumors, and in the response of tumors to treatment have not been fully delineated, but the likely contributions of GFR signaling to the development and progression of various malignancies suggest that therapies that modify GFR trafficking may be effective as anticancer treatments.
The intracellular trafficking of GFRs is regulated by a number of protein complexes and by protein ubiquitination. Many of the proteins required for this trafficking are products of tumor suppressor genes, and the expression and function of the protein machinery utilized for intracellular trafficking is frequently altered in tumor cells, consistent with the likely role of GFR trafficking in tumorigenesis. Many of the proteins involved in GFR trafficking have been identified as potential targets for anticancer treatment, and novel treatments directed against these targets are currently in preclinical development and in clinical trials. Ubiquitin ligases are critical for GFR trafficking and represent potentially important targets for the development of novel therapies.
The genes for the ubiquitin ligases
Despite of several decades of efforts, lung cancer remains one of most deadly diseases, with a 5-year survival rate approximately 15% worldwide. In China, the situation is even worse. Although there is no official data released yet, the 5-year survival rate is estimated to be around 10%. In past 30 years, there was a dramatic increase of lung cancer related death about 465% in mainland China. Annually, about 400000 people die of lung cancer and the number is still climbing. At the same time, the number of new lung cancer cases also increase rapidly. The high mortality of lung cancer is mainly ascribed to two factors: the lack of effective ways to identify early diagnostic biomarkers and to treat metastatic cancer. Lung cancer can be pathologically divided into small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), among which NSCLC accounts for about 80% of all cases. In this review, we will focus on the recent efforts and progress in finding biomarkers in NSCLC. Since biomarkers are derived from both invasive and non-invasive ways, we divide them into these two categories and review them separately. We hope the discovery of biomarkers will eventually change the current clinical practice in NSCLC patients and improve their quality of life.
The development of spinal cord is a precisely and sequentially regulated process, which is controlled by signaling pathways and transcription factors in each stage. Overwhelming data have shown the essential roles of BMP signaling in different stages of this developmental process. It is also clear that the proper functions of BMP signaling require its cross-talk with several other signaling pathways including Notch, Wnt and retinoic acid (RA) pathways. Here, we highlight the recent advancement in understanding the roles of BMP signaling during neurogenesis, neural tube patterning, axon development and glial differentiation in the spinal cord, and emphasize its integrations with other pathways during these processes.
Emerging research has suggested that inflammatory stress may play a role in the development of obesity. Both the leptin and insulin receptor are sensitive to intracellular inflammatory signaling that can be stimulated through toll-like receptor 4 activation by saturated fat. Pharmacological intervention within this cascade often protects animals from becoming obese, thus highlighting inflammatory pathways as a possible site of study in the prevention of pathologic weight gain. It has been well established in animal models that females display a marked reduction in the susceptibility to weight gain on high-fat diets compared to males. In addition, it has been widely accepted that females are partially protected from inflammatory-related diseases. At the molecular level, this reduction in disease susceptibility has been suggested to be due to the anti-inflammatory properties of 17 β-estradiol. Through direct free radical scavenging, transcriptional regulation, and protein interactions, chronic exposure to estradiol can reduce systemic inflammatory stress. As the knowledge base continues to grow on the etiology of obesity, further research is needed on the precise molecular pathways that can be inhibited by estradiol. Understanding of such pathways may provide a basis for the future use of estrogen and its related compounds (daidzein, genistein, resveratrol) to prevent weight gain in peri- and post-menopausal females.
Jasmonic acid (JA) is a natural hormone regulator involved in development, responses against wounding and pathogen attack. Upon perception of pathogens, JA is synthesized and mediates a signaling cascade initiating various defense responses. Traditionally, necrotrophic fungi have been shown to be the primary activators of JA-dependent defenses through the JA-receptor, COI1. Conversely, plants infected with biotrophic fungi have classically been associated with suppressing JA-mediated responses. However, recent evidence has shown that certain biotrophic fungal species also trigger activation of JA-mediated responses and mutants deficient in JA signaling show an increase in susceptibility to certain biotrophic fungal pathogens. These findings suggest a new role for JA in defense against fungal biotrophs. This review will focus on recent research advancing our knowledge of JA-dependant responses involved in defense against both biotrophic and necrotrophic fungi.
F?rster resonance energy transfer (FRET) techniques have been widely used in biological studies
Gene expression profiling of
During embryo development in many metazoan animals, the first differentiated cell type to form is an epithelial cell. This epithelial layer is modified by developmental cues of body axes formation to give rise to various tissues. The cells that arise are mesenchymal in nature and are a source of other tissue types. This epithelial to mesenchymal transition is used for tissue type formation and also seen in diseases such as cancer. Here we discuss recent findings on the cellular architecture formation in the