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Targeting RET to induce medullary thyroid cancer cell apoptosis: an antagonistic interplay between PI3K/Akt and

Minakshi Mazumdar1, Arghya Adhikary, Samik Chakraborty

  • 1Division of Molecular Medicine, Bose Institute, P-1/12, Calcutta Improvement Trust Road, Scheme VII M, Kolkata, West Bengal, 700 054, India.

Apoptosis : an International Journal on Programmed Cell Death
|January 19, 2013
PubMed

Insights

Theaflavins from black tea induce programmed cell death in medullary thyroid carcinoma (MTC) by targeting the RET pathway. This research highlights theaflavins as a potential therapeutic strategy for MTC.

Area of Science:

  • Oncology
  • Molecular Biology
  • Biochemistry

Background:

  • Medullary thyroid carcinoma (MTC) is driven by RET receptor tyrosine kinase mutations.
  • MTC exhibits poor response to conventional chemotherapy, necessitating novel therapeutic targets.
  • RET signaling is crucial for MTC cell survival and proliferation.

Purpose of the Study:

  • To investigate the anti-cancer effects of theaflavins, black tea components, on MTC.
  • To elucidate the molecular mechanisms underlying theaflavin-induced apoptosis in MTC cells.
  • To validate RET as a therapeutic target for MTC.

Main Methods:

  • Utilized human MTC cell line (TT) for in vitro studies.
  • Investigated theaflavin's impact on key signaling pathways (PI3K/Akt/Bad, p38MAPK/caspase-8/caspase-3, Ras/Raf/ERK).
  • Employed gene manipulation techniques (over-expression of Myr-Akt-cDNA, Dn-caspase-8-cDNA) to dissect apoptotic pathways.
  • Analyzed the role of lipid rafts and RET anchorage in theaflavin's mechanism of action.

Main Results:

  • Theaflavins induced apoptosis in MTC cells by modulating PI3K/Akt/Bad and p38MAPK/caspase-8/caspase-3 pathways.
  • Theaflavins caused loss of mitochondrial transmembrane potential, cytochrome-c release, and caspase activation.
  • Disruption of lipid rafts by theaflavins interfered with RET anchorage, inhibiting Ras and PI3Kinase phosphorylation.
  • Over-expression studies confirmed the involvement of Akt and caspase-8 in theaflavin-induced apoptosis.

Conclusions:

  • Theaflavins trigger programmed cell death in MTC through a novel mechanism involving RET signaling disruption.
  • Theaflavins represent a promising therapeutic agent for MTC, targeting the oncogenic RET pathway.
  • This study validates RET as a key target for developing novel MTC therapies.

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