title: LRIG and cancer prognosis.
abstract: BACKGROUND
  Optimal treatment decisions for cancer patients require reliable prognostic and predictive information. However, this information is inadequate in many cases. Several recent studies suggest that the leucine-rich repeats and immunoglobulin-like domains (LRIG) genes, transcripts, and proteins have prognostic implications in various cancer types.
  
  
  METHODS
  Relevant literature was identified on PubMed using the key words lrig1, lrig2, and lrig3. LRIG mRNA expression in cancer versus normal tissues was investigated using the Oncomine database.
  
  
  RESULTS
  The three human LRIG genes, LRIG1, LRIG2, and LRIG3, encode single-pass transmembrane proteins. LRIG1 is a negative regulator of growth factor signaling that has been shown to function as a tumor suppressor in vitro and in vivo in mice. The functions of LRIG2 and LRIG3 are less well defined. LRIG gene and protein expression are commonly dysregulated in human cancer. In early stage breast cancer, LRIG1 copy number was recently shown to predict early and late relapse in addition to overall survival; in nasopharyngeal carcinoma, loss of LRIG1 is also associated with poor survival. LRIG gene and protein expression have prognostic value in breast cancer, uterine cervical cancer, head-and-neck cancer, glioma, non-small cell lung cancer, prostate cancer, and cutaneous squamous cell carcinoma. In general, expression of LRIG1 and LRIG3 is associated with good survival, whereas expression of LRIG2 is associated with poor survival. Additionally, LRIG1 regulates cellular sensitivity to anti-cancer drugs, which indicates a possible role as a predictive marker.
  
  
  CONCLUSIONS
  LRIG gene statuses and mRNA and protein expression are clinically relevant prognostic indicators in several types of human cancer. We propose that LRIG analyses could become important when making informed and individualized clinical decisions regarding the management of cancer patients.
authors.affiliation: Oncology Research Laboratory, Department of Radiation Sciences, Umeå University , Umeå , Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Lindquist
authors.forename: Samuel
authors.initials: S
authors.lastname: Kvarnbrink
authors.forename: Roger
authors.initials: R
authors.lastname: Henriksson
authors.forename: Håkan
authors.initials: H
authors.lastname: Hedman
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism / Q000401:mortality; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000401:mortality; D015536:Down-Regulation; D005260:Female; D015870:Gene Expression; D016147:Genes, Tumor Suppressor; D005910:Glioma / Q000235:genetics / Q000378:metabolism / Q000401:mortality; D006258:Head and Neck Neoplasms / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000401:mortality; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009303:Nasopharyngeal Neoplasms / Q000235:genetics / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D009364:Neoplasm Recurrence, Local; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality; D011379:Prognosis; D012333:RNA, Messenger / Q000378:metabolism; D015854:Up-Regulation; D002583:Uterine Cervical Neoplasms / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C484445:LRIG1 protein, human; C488673:LRIG2 protein, human; C496406:LRIG3 protein, human; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger