MMAC1/PTEN inhibits cell growth and induces chemosensitivity to doxorubicin in human bladder cancer cells

Oncogene. 2000 Nov 9;19(47):5406-12. doi: 10.1038/sj.onc.1203918.


The development and progression of bladder cancer is associated with multiple alterations in the genome, including loss of chromosome 10. Recently, MMAC1/PTEN, a phosphatidylinositol phosphatase, has been mapped to chromosome 10q23. We previously demonstrated that MMAC1/PTEN has tumor suppressive properties in glioblastoma and prostate cancer. To investigate the efficacy of gene therapy with MMAC1/PTEN, we examined whether the exogenous introduction of MMAC1/PTEN via an adenoviral vector (Ad-MMAC) can inhibit tumor growth and reverse drug resistance to doxorubicin in human bladder cancer cells. Human bladder cancer cell lines UM-UC-3 and T24 were infected with Ad-MMAC to induce exogenous expression of MMAC1/PTEN. The cells were then analysed for cell growth and expression of phosphorylated protein kinase B (Akt/PKB) and MMAC1/PTEN. UM-UC-6dox, a doxorubicin resistant subline, was infected with Ad-MMAC to evaluate its role in reversing drug resistance to doxorubicin. We found that MMAC1/PTEN suppressed tumor growth in UM-UC-3 and T24 cells with arrest in the G1 phase of the cell cycle. We also showed that gene therapy with MMAC1/PTEN abrogated phosphorylated Akt/PKB expression in UM-UC-3, T24 and UMUC-6dox cells, and restored doxorubicin sensitivity in UM-UC-6dox. These data demonstrate that MMAC1/PTEN can induce growth suppression and increase sensitivity to doxorubicin in bladder cancer cells and suggest that the MMAC1/PTEN gene and its pathways can be therapeutic targets for bladder cancer.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenoviruses, Human
  • Antineoplastic Agents / pharmacology*
  • Cell Cycle
  • Cell Division
  • Doxorubicin / pharmacology*
  • Gene Expression
  • Genes, Tumor Suppressor / physiology*
  • Genetic Vectors
  • Humans
  • PTEN Phosphohydrolase
  • Phosphoric Monoester Hydrolases / genetics
  • Phosphoric Monoester Hydrolases / physiology*
  • Protein-Serine-Threonine Kinases*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Tumor Cells, Cultured
  • Tumor Suppressor Proteins*
  • Urinary Bladder Neoplasms / therapy*


  • Antineoplastic Agents
  • Proto-Oncogene Proteins
  • Tumor Suppressor Proteins
  • Doxorubicin
  • AKT1 protein, human
  • Protein-Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Phosphoric Monoester Hydrolases
  • PTEN Phosphohydrolase
  • PTEN protein, human