Impact of gene dosage on gene expression, biological processes and survival in cervical cancer: a genome-wide follow-up study

PLoS One. 2014 May 30;9(5):e97842. doi: 10.1371/journal.pone.0097842. eCollection 2014.

Abstract

We investigated the role of tumor copy number (CN)-altered genome (CN-AG) in the carcinogenesis of cervical cancer (CC), especially its effect on gene expression, biological processes, and patient survival. Fifty-nine human papillomavirus 16 (HPV16)-positive CCs were investigated with microarrays-31 for mapping CN-AG and 55 for global gene expression, with 27 CCs in common. Five-year survival was investigated in 55 patients. Deletions and amplifications >2.5 Mb were defined as CN alterations. The %CN-AG varied from 0 to 32.2% (mean = 8.1±8.9). Tumors were classified as low (mean = 0.5±0.6, n = 11), medium (mean = 5.4±2.4, n = 10), or high (mean = 19.2±6.6, n = 10) CN. The highest %CN-AG was found in 3q, which contributed an average of 55% of all CN alterations. Genome-wide, only 5.3% of CN-altered genes were deregulated directly by gene dosage. In contrast, the rate in fully duplicated 3q was twice as high. Amplification of 3q explained 23.2% of deregulated genes in whole tumors (r2 = 0.232, p = 0.006; analysis of variance), including genes located in 3q and other chromosomes. A total of 862 genes were deregulated exclusively in high-CN tumors, but only 22.9% were CN altered. This suggests that the remaining genes are not deregulated directly by gene dosage, but by mechanisms induced in trans by CN-altered genes. Anaphase-promoting complex/cyclosome (APC/C)-dependent proteasome proteolysis, glycolysis, and apoptosis were upregulated, whereas cell adhesion and angiogenesis were downregulated exclusively in high-CN tumors. The high %CN-AG and upregulated gene expression profile of APC/C-dependent proteasome proteolysis were associated with poor patient survival (p<0.05, log-rank test). Along with glycolysis, they were linearly associated with FIGO stage (r>0.38, p<0.01, Spearman test). Therefore, inhibition of APC/C-dependent proteasome proteolysis and glycolysis could be useful for CC treatment. However, whether they are indispensable for tumor growth remains to be demonstrated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Carcinogenesis / genetics
  • Chromosomes, Human / genetics
  • Female
  • Follow-Up Studies
  • Gene Dosage*
  • Gene Expression Profiling*
  • Genes, Neoplasm / genetics
  • Genomics*
  • Human papillomavirus 16 / physiology
  • Humans
  • Middle Aged
  • Survival Analysis
  • Uterine Cervical Neoplasms / genetics*
  • Uterine Cervical Neoplasms / pathology
  • Uterine Cervical Neoplasms / virology
  • Young Adult

Associated data

  • GEO/GSE52904

Grants and funding

This work was supported by the National Council of Science and Technology (CONACYT, www.conacyt.mx), grant numbers 8135/A1, 24341 (to JB), 80680 (to SK) and 133273 (to FF) and the National University of Mexico (www.unam.mx), grant number SDI.PTID.05.2 (to JB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.