Related Experiment Video

Updated: Aug 6, 2026

Through the Looking Glass: Time-lapse Microscopy and Longitudinal Tracking of Single Cells to Study Anti-cancer Therapeutics
06:00

Through the Looking Glass: Time-lapse Microscopy and Longitudinal Tracking of Single Cells to Study Anti-cancer Therapeutics

Published on: May 14, 2016

Chemopreventive effects of green tea polyphenols correlate with reversible induction of p57 expression

S Hsu1, J B Lewis, J L Borke

  • 1Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta 30912-1126, USA. shsu@mail.mcg.edu

Anticancer Research
|March 26, 2002
PubMed

Insights

Green tea polyphenols, particularly EGCG, increase p57 protein in normal cells but not tumor cells. This suggests green tea

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • Green tea polyphenols are recognized for their ability to induce apoptosis in tumor cells.
  • The mechanisms by which normal cells resist this apoptotic effect remain unclear.
  • Understanding differential cellular responses is crucial for chemoprevention strategies.

Purpose of the Study:

  • To investigate the role of p57, an apoptosis inhibitor, in the differential response of normal and tumor cells to green tea polyphenols.
  • To elucidate the molecular mechanisms underlying the chemopreventive effects of green tea polyphenols.

Main Methods:

  • Western blot analysis was employed to assess protein expression levels.
  • Cycloheximide treatment was used to study protein synthesis and degradation.
  • Apoptosis was detected using the annexin V assay.

Main Results:

  • (-)-Epigallocatechin-3-gallate (EGCG), a potent green tea polyphenol, dose- and time-dependently induced p57 expression in normal human keratinocytes.
  • Oral carcinoma cell lines (SCC25 and OSC2) showed no alteration in p57 protein levels upon EGCG treatment.
  • The differential induction of p57 correlated with the apoptosis status observed via annexin V assay.

Conclusions:

  • Green tea polyphenols exhibit differential effects on p57 expression in normal versus cancerous cells.
  • The induction of p57 in normal cells may contribute to their resistance to apoptosis induced by green tea polyphenols.
  • p57-mediated cell cycle regulation in normal epithelial cells is a potential mechanism for the chemopreventive effects of green tea.

More Related Videos

Extraction and Purification of Polyphenols from Freeze-dried Berry Powder for the Treatment of Vascular Smooth Muscle Cells In Vitro12:00

Extraction and Purification of Polyphenols from Freeze-dried Berry Powder for the Treatment of Vascular Smooth Muscle Cells In Vitro

Published on: July 5, 2017

Yeast As a Chassis for Developing Functional Assays to Study Human P5314:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

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.
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Cancer Prevention02:59

Cancer Prevention

Several factors can increase the risk of cancer in an individual. About 50% of cancer cases can be prevented by adopting a healthy lifestyle, regular exercise, eating healthy, and following a modest cancer prevention diet. Epidemiological studies have consistently shown that populations with vegetable and fruit-rich diets have reduced the incidence of cancer. On the other hand, populations who have a diet rich in animal fat, red meat, junk food, or high calories are predisposed to cancer.
Some...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase01:11

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase

Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...