Inactivation of SLIT2-ROBO1/2 pathway in premalignant lesions of uterine cervix: clinical and prognostic significances

PLoS One. 2012;7(6):e38342. doi: 10.1371/journal.pone.0038342. Epub 2012 Jun 13.

Abstract

The SLIT2-ROBO1/2 pathways control diverse biological processes, including growth regulation. To understand the role of SLIT2 and ROBO1/2 in cervical carcinogenesis, firstly their RNA expression profiles were screened in 21 primary uterine cervical carcinoma (CACX) samples and two CACX cell lines. Highly reduced expressions of these genes were evident. Concomitant alterations [deletion/methylation] of the genes were then analyzed in 23 cervical intraepithelial neoplasia (CIN) and 110 CACX samples. In CIN, SLIT2 was deleted in 22% samples compared to 9% for ROBO1 and none for ROBO2, whereas comparable methylation was observed for both SLIT2 (30%) and ROBO1 (22%) followed by ROBO2 (9%). In CACX, alteration of the genes were in the following order: Deletion:ROBO1 (48%) > SLIT2 (35%) > ROBO2 (33%), Methylation:SLIT2 (34%) > ROBO1 (29%) > ROBO2 (26%). Overall alterations of SLIT2 and/or ROBO1 (44%) and SLIT2 and/or ROBO2 (39%) were high in CIN followed by significant increase in stage I/II tumors, suggesting deregulation of these interactions in premalignant lesions and early invasive tumors. Immunohistochemical analysis of SLIT2 and ROBO1/2 in CACX also showed reduced expression concordant with molecular alterations. Alteration of all these genes predicted poor patient outcome. Multiparous (≥ 5) women with altered SLIT2 and ROBO1 along with advanced tumor stage (III/IV) and early sexual debut (<19 years) had worst prognosis. Our data suggests the importance of abrogation of SLIT2-ROBO1 and SLIT2-ROBO2 interactions in the initiation and progression of CACX and also for early diagnosis and prognosis of the disease.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Azacitidine / analogs & derivatives
  • Azacitidine / pharmacology
  • Cell Line, Tumor
  • DNA Methylation
  • Decitabine
  • Female
  • Gene Silencing*
  • Humans
  • Immunohistochemistry
  • Intercellular Signaling Peptides and Proteins / genetics*
  • Nerve Tissue Proteins / genetics*
  • Precancerous Conditions / genetics*
  • Precancerous Conditions / pathology
  • Prognosis
  • Promoter Regions, Genetic
  • Receptors, Immunologic / genetics*
  • Roundabout Proteins
  • Uterine Cervical Neoplasms / genetics*
  • Uterine Cervical Neoplasms / pathology

Substances

  • Intercellular Signaling Peptides and Proteins
  • Nerve Tissue Proteins
  • ROBO2 protein, human
  • Receptors, Immunologic
  • Decitabine
  • Azacitidine
  • Slit homolog 2 protein