Related Experiment Video

Updated: Aug 8, 2026

Analysis of Cell Cycle Position in Mammalian Cells
12:19

Analysis of Cell Cycle Position in Mammalian Cells

Published on: January 21, 2012

Ki-67 as a marker for cell cycle regulation by interferon

D Lundblad1, G Landberg, G Roos

  • 1Institute of Applied Cell and Molecular Biology, University of Umeå, Sweden.

Anticancer Research
|November 1, 1991
PubMed

Insights

Interferon (IFN) treatment reduced Ki-67 expression in some cancer cells but not others. Ki-67 antigen is not a reliable marker for monitoring clinical effects of IFN therapy.

Area of Science:

  • Cell biology
  • Immunology
  • Oncology

Background:

  • Interferon (IFN) is a crucial cytokine in immune response and cancer therapy.
  • Ki-67 is a nuclear antigen commonly used as a marker for cell proliferation.

Purpose of the Study:

  • To investigate the effect of interferon on Ki-67 expression in different cancer cell lines.
  • To determine if Ki-67 can serve as a reliable biomarker for interferon treatment efficacy.

Main Methods:

  • Treatment of IFN-sensitive (Daudi, 251 MG) and IFN-resistant (Namalwa) cell lines with interferon.
  • Analysis of Ki-67 expression and cell cycle distribution using flow cytometry.
  • Induction of cell cycle arrest via serum deprivation and restimulation.

Main Results:

  • IFN treatment decreased Ki-67 expression in GO/G1-arrested Daudi cells, correlating with growth arrest.
  • No significant change in Ki-67 expression was observed in IFN-resistant Namalwa cells or S-phase-arrested 251 MG cells.
  • Serum deprivation abolished Ki-67 expression in 251 MG cells, with expression resuming upon restimulation and S-phase entry.

Conclusions:

  • Ki-67 antigen downregulation is cell-cycle and IFN-sensitivity dependent.
  • Ki-67 is not a universally reliable marker for monitoring clinical responses to interferon therapy across all cancer types.

More Related Videos

A High Resolution Method to Monitor Phosphorylation-dependent Activation of IRF311:44

A High Resolution Method to Monitor Phosphorylation-dependent Activation of IRF3

Published on: January 24, 2016

A DNA/Ki67-Based Flow Cytometry Assay for Cell Cycle Analysis of Antigen-Specific CD8 T Cells in Vaccinated Mice09:17

A DNA/Ki67-Based Flow Cytometry Assay for Cell Cycle Analysis of Antigen-Specific CD8 T Cells in Vaccinated Mice

Published on: January 5, 2021

Related Concept Videos

Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Mitogens and the Cell Cycle02:38

Mitogens and the Cell Cycle

Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...
Mitogens and the Cell Cycle02:38

Mitogens and the Cell Cycle

Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...
Molecular Factors Affecting Cell Division01:27

Molecular Factors Affecting Cell Division

Several external and internal factors influence the initiation and inhibition of cell division. For instance, the death of nearby cells or the release of human growth hormone (hGH) promotes cell division. In contrast, lack of hGH or crowding of cells can inhibit cell division.
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...
Inhibitors of Viral Protein Synthesis01:30

Inhibitors of Viral Protein Synthesis

Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...