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Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes
15:43

Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes

Published on: January 7, 2013

Expression of kinase suppressor of Ras1 enhances cisplatin-induced extracellular signal-regulated kinase activation

Min Kim1, Ying Yan, Robert L Kortum

  • 1Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA.

Cancer Research
|May 19, 2005
PubMed

Insights

Kinase suppressor of Ras1 (KSR1) regulates the ERK pathway. Loss of KSR1 increases resistance to cisplatin (CDDP) chemotherapy, while its presence enhances cancer cell sensitivity to CDDP by modulating ERK activity.

Area of Science:

  • Molecular Biology
  • Cell Signaling
  • Cancer Research

Background:

  • Kinase suppressor of Ras1 (KSR1) is a positive regulator of the Ras signaling cascade, interacting with key mitogen-activated protein (MAP) kinase pathway components.
  • Cisplatin (cis-diamminedichloroplatinum, CDDP) is an anticancer agent that affects multiple signal transduction pathways, including the extracellular signal-regulated kinase (ERK) pathway.
  • ERK activation is implicated in cell survival following CDDP treatment.

Purpose of the Study:

  • To investigate the role of KSR1 expression in modulating cancer cell sensitivity to CDDP-induced apoptosis.
  • To determine the impact of KSR1 on CDDP-induced ERK activation.

Main Methods:

  • Comparison of CDDP-induced apoptosis and ERK activation in KSR1 knockout (KSR-/-) mouse embryo fibroblasts (MEFs) and wild-type (KSR+/+) MEFs.
  • Transduction of KSR-/- MEFs and MCF-7 breast cancer cells with wild-type KSR1.
  • Assessment of CDDP sensitivity and ERK activation following treatment with MEK1/2 inhibitors (PD98059 and U0126).

Main Results:

  • KSR1 knockout MEFs exhibited reduced CDDP-induced ERK activation and increased resistance to CDDP-induced apoptosis compared to wild-type MEFs.
  • Restoration of KSR1 in KSR-/- MEFs and MCF-7 cells led to enhanced ERK activation and increased sensitivity to CDDP.
  • Inhibition of ERK activation using MEK1/2 inhibitors protected both KSR+/+ and KSR-/- MEFs from CDDP-induced apoptosis.

Conclusions:

  • KSR1 plays a crucial role in regulating ERK activity in response to CDDP treatment.
  • KSR1-mediated regulation of ERK activity is a significant determinant of cancer cell sensitivity to CDDP.
  • Targeting the KSR1-ERK pathway may offer novel therapeutic strategies for enhancing CDDP efficacy in cancer treatment.

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