Research Highlights

Short, accessible synopses of recent important articles concerning signalling pathways.

September 2009

• Tumorigenesis: Replicating recurrence

  

  Transgenic mice have been crucial for the study of oncogene-induced tumorigenesis and tumour regression. However, the need for substantial numbers of mice to replicate results has made this approach costly and time-consuming. Martin Jechlinger and colleagues have examined whether three-dimensional (3D) culture techniques can be used to more easily address the subtle effects that oncogene deregulation has on primary cell growth and morphology.

  Original research paper Nature Reviews Cancer 9 613 doi:10.1038/nrc2722

• T cell development: Lead role for BCL-6 in T_FH cell development

  

  The requirement for T cell help for B cells has been known for many years, but it is only recently that specialized T cells - T follicular helper (T_FH) cells - have been identified that express high levels of CXC-chemokine receptor 5 (CXCR5), which enables them to localize to B cell follicles during T cell-dependent immune responses. Although the phenotype of TFH cells has been well characterized, the factors governing their differentiation are poorly understood. Now, three studies show that the transcription factor B cell lymphoma 6 (BCL-6) is a master regulator of TFH cell differentiation.

  Original research paper Nature Reviews Immunology 9 605 doi:10.1038/nri2626

• Thymocyte development: The identification of THEMIS

  

  Three independent groups have identified a previously unknown T cell-specific protein that has a unique role during late thymocyte selection and CD4 versus CD8 lineage choice, which they collectively have termed thymocyte-expressed molecule involved in selection (THEMIS).

  Original research paper Nature Reviews Immunology 9 604 - 605 doi:10.1038/nri2624

• Migration: Exchange to migrate

  

  Activation of GABA_ARs (γ-aminobutyric acid type A receptors) leads to the elevation of intracellular Ca²⁺ concentration ([Ca²⁺]i in immature neurons, through a well-established signalling pathway that is important for neuronal migration. NG2 cells - a group of glial precursors - also express GABA_ARs; however, the function of these receptors in NG2 cells was unknown. Tong et al. have now shown that the activation of GABA_ARs in NG2 cells triggers a different Ca²⁺ signalling pathway that involves reversal of the activity of the Na+-Ca²⁺ exchanger 1 (NCX1) and is required for the migration of NG2 cells during development.

  Original research paper Nature Reviews Neuroscience 10 622 - 623 doi:10.1038/nrn2706

• Axon guidance: Sorting themselves out

  

  How do the topographic maps that are characteristic of sensory brain regions form during development? Sakano and colleagues show that interactions between neuropilin 1 (NRP1) and its ligand semaphorin 3A (SEMA3A) regulate the organization of olfactory sensory neuron (OSN) axons long before they reach their targets in the olfactory bulb.

  Original research paper Nature Reviews Neuroscience 10 624 - 625 doi:10.1038/nrn2711