Research Highlights

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

March 2011

• Cancer biology: Role of nuclear PTEN revealed

  

  In the cytoplasm, the tumour suppressor protein phosphatase and tensin homologue (PTEN) dephosphorylates phosphoinositide-3,4,5-triphosphate to inhibit phosphoinositide 3-kinase (PI3K)–AKT signalling, cell growth and cell survival. Nuclear PTEN also has a tumour-suppressive role, but its functions were unknown. Song et al. now show that nuclear PTEN interacts with the anaphase-promoting complex (APC), an E3 ubiquitin ligase that degrades components of the cell cycle machinery, to enhance its activity.

  Original research paper Nature Reviews Molecular Cell Biology 12 134 doi:10.1038/nrm3069

• Microrna: Micromanaging CD44

  

  CD44 is a receptor for hyaluronan and although heralded as a marker of cancer stem cells (CSCs) in many tumours, whether and how CD44 expression contributes to the biology of CSCs are questions that still require answers. By finding that CD44 is a target of the microRNA miR-34a, Dean Tang and colleagues identified one way of looking at the requirement of CD44 for CSC function in prostate cancer.

  Original research paper Nature Reviews Cancer 11 156 doi:10.1038/nrc3024

• Development: New rules of attraction

  

  The interaction between CXC-chemokine ligand 12 (CXCL12) and CXC-chemokine receptor 4 (CXCR4) plays a key part in cell migration during CNS development. More recently, CXCR7 has also been identified as a receptor for CXCL12, but the physiological significance of this finding was unknown. Two papers in Neuron now show a role for CXCR7 in the developing CNS that is distinct from, but interacts with, the role of CXCR4.

  Original research paper Nature Reviews Neuroscience 12 124 - 125 doi:10.1038/nrn3001

• Memory: A growing role for IGF2

  

  Insulin-like growth factor 2 (IGF2) is important in body growth and development, but its role in the adult brain has not been established. It is highly expressed in the hippocampus, and Alberini and colleagues now show that in this region it has a crucial role in memory consolidation and can improve memory retention.

  Original research paper Nature Reviews Neuroscience 12 122 doi:10.1038/nrn2997

• Prostate cancer: Prostate quartet

  

  Current methods to measure aggressiveness of prostate adenocarcinoma (PCA) are based on pathological and clinical characteristics of the tumour cells — such as Gleason score or levels of prostate-specific antigen (PSA) — but these are often inadequate given the heterogeneity of this type of cancer. Ron DePinho and colleagues have now identified a four-gene signature that is able to predict recurrence and metastasis more accurately in human PCAs.

  Original research paper Nature Reviews Cancer 11 159 doi:10.1038/nrc3029