PI3K inhibitor enhances the cytotoxic response to etoposide and cisplatin in a newly established neuroendocrine cervical carcinoma cell line

Oncotarget. 2017 Jul 11;8(28):45323-45334. doi: 10.18632/oncotarget.17335.

Abstract

Background: Neuroendocrine cervical carcinoma (NECC) is a rare and aggressive subtype of cervical cancer. To date, no NECC cell-based model is available, which hinders the development of new therapeutic strategies for NECC. In this study, we derived a new NECC cell line from an ex vivo biopsy and used it to explore novel drug combination approach for NECC.

Results: The stable HM-1 cell line displayed high expression levels of the neuroendocrine marker, synaptophysin. HM-1 cell transplantation could induce tumor growth in nude mice. As expected, the combination of etoposide and cisplatin synergistically inhibited HM-1 cell proliferation. Strikingly, when etoposide and cisplatin were combined with PI3K inhibitor BEZ235, the growth of HM-1 cells was significantly reduced. Taken together, the data implied the combination of etoposide and cisplatin with BEZ235 not only inhibited HM-1 cell proliferation but also increased cell apoptosis.

Materials and methods: A NECC tissue sample from a 75-year-old female patient was processed to derive a primary cell line annotated as HM-1. The features of HM-1 were analyzed to establish its characteristic profile. Next, HM-1 was treated with PI3K inhibitors, BKM120 and/or BEZ235, in combination with two well-known genotoxic drugs, etoposide and/or cisplatin, to evaluate which combination could serve as a more effective treatment approach. Their inhibiting effects on HM-1 were evaluated by cell viability, apoptosis, and target kinase expression.

Conclusions: The newly established NECC cell line HM-1 could serve as a cell-based model for NECC research. The synergistic drug combination of PI3K inhibitor with genotoxic drugs might become a potential new treatment strategy against NECC.

Keywords: BEZ235; PI3K inhibitor; combination therapy; genotoxic drug; neuroendocrine cervical carcinoma.

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects
  • Biomarkers
  • Carcinoma, Neuroendocrine / drug therapy
  • Carcinoma, Neuroendocrine / etiology
  • Carcinoma, Neuroendocrine / metabolism
  • Carcinoma, Neuroendocrine / pathology
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cisplatin / pharmacology*
  • DNA Damage / drug effects
  • Disease Models, Animal
  • Drug Synergism
  • Etoposide / pharmacology*
  • Female
  • Humans
  • Mice
  • Papillomavirus Infections / complications
  • Papillomavirus Infections / virology
  • Phosphoinositide-3 Kinase Inhibitors*
  • Uterine Cervical Neoplasms / drug therapy
  • Uterine Cervical Neoplasms / etiology
  • Uterine Cervical Neoplasms / metabolism
  • Uterine Cervical Neoplasms / pathology
  • Xenograft Model Antitumor Assays

Substances

  • Antineoplastic Agents
  • Biomarkers
  • Phosphoinositide-3 Kinase Inhibitors
  • Etoposide
  • Cisplatin