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Caspase-2/NEDD-2 protease mediates execution of apoptosis in AK-5 tumor cells

A Khar1, B V Pardhasardhi, C Varalakshmi

  • 1Centre for Cellular and Molecular Biology, Hyderabad, India. khar@ccmb.ap.nic.in

Apoptosis : an International Journal on Programmed Cell Death
|January 1, 1997
PubMed

Insights

This study reveals that caspase-2 (Nedd-2) protease and bcl-2 gene are crucial for AK-5 tumor cell apoptosis and regression. Inhibiting these pathways prevents tumor cell death and spontaneous regression.

Area of Science:

  • Oncology
  • Molecular Biology
  • Immunology

Background:

  • AK-5 tumor cells undergo apoptosis and necrosis, leading to spontaneous tumor regression.
  • Natural Killer (NK) cells are identified as effector cells in this process.

Purpose of the Study:

  • To investigate the role of caspase-2 (Nedd-2) protease in AK-5 tumor cell apoptosis.
  • To determine the involvement of the bcl-2 gene in the apoptotic pathway of AK-5 tumors.
  • To understand the impact of Nedd-2 and bcl-2 on NK cell-mediated apoptosis.

Main Methods:

  • Introduction of Nedd-2 gene in antisense orientation into AK-5 tumor cells.
  • Transfection of AK-5 tumor cells with the bcl-2 gene.
  • Assessment of NK cell-mediated apoptosis and cytotoxic activity in transfected cells.

Main Results:

  • Inhibition of Nedd-2 gene via antisense orientation suppressed AK-5 tumor cell apoptosis.
  • Introduction of the bcl-2 gene also inhibited the apoptotic program in tumor cells.
  • NK cells failed to induce apoptosis in Nedd-2 antisense and bcl-2 transfected clones, while cytotoxic activity remained unaffected.

Conclusions:

  • Caspase-2 (Nedd-2) protease plays a significant role in inducing apoptosis in AK-5 cells.
  • The bcl-2 gene is also involved in regulating the apoptotic process in AK-5 tumors.
  • These findings suggest that Nedd-2 protease is critical for AK-5 tumor regression mediated by apoptosis.

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