Related Experiment Videos
The molecular regulation of apoptosis and implications for radiation oncology
K R Blank1, M S Rudoltz, G D Kao
1Department of Radiation Oncology, University of Pennsylvania, Philadelphia 19104, USA.
Abstract:
One of the major goals of cancer research is to identify and understand the causes of cellular proliferation. The role of cell death, or lack thereof, in carcinogenesis, tumour growth, metastatic spread and response to treatment has been largely overlooked even though the morphology of apoptosis (programmed cell death) was clearly described over 20 years ago, and its importance in cancer speculated on at that time. Over the last 5 years, however, an explosion of research has focused on delineating the molecular components of the apoptotic pathways and examining the role of apoptosis in a tumour's growth and response to treatment. This review highlights the aspects of apoptosis most relevant to radiation oncologists and radiobiologists. The apoptotic pathways will be described, with attention to the stimuli that initiate apoptosis, the oncogenes and tumour suppressor genes that mediate apoptosis, and the effector enzymes (proteases and endonucleases) responsible for the execution of apoptosis. In addition, we review the effect of classically described radiobiology cell survival parameters-cell cycle stage, dose rate, linear energy transfer, oxygen, total dose, and fractionation-on radiation induced apoptosis.
Insights
Apoptosis, or programmed cell death, plays a crucial role in cancer development and treatment response. Understanding apoptotic pathways is vital for cancer research and radiation oncology.
Area of Science:
- Oncology
- Molecular Biology
- Radiobiology
Background:
- Cancer research traditionally focuses on cellular proliferation, often overlooking the role of programmed cell death (apoptosis).
- Despite early descriptions, the significance of apoptosis in carcinogenesis, tumor growth, metastasis, and treatment response has been historically underestimated.
- Recent research has intensified, focusing on the molecular mechanisms and cancer relevance of apoptosis.
Purpose of the Study:
- To review the key aspects of apoptosis relevant to radiation oncologists and radiobiologists.
- To describe the molecular pathways, initiating stimuli, and mediating genes involved in apoptosis.
- To examine the influence of radiobiological factors on radiation-induced apoptosis.
Main Methods:
- Literature review focusing on apoptosis and its role in cancer.
- Detailed description of apoptotic pathways, including molecular components and effector enzymes.
- Analysis of the impact of radiobiological parameters on radiation-induced apoptosis.
Main Results:
- Apoptosis pathways involve specific stimuli, oncogenes, tumor suppressor genes, proteases, and endonucleases.
- Radiobiological factors such as cell cycle, dose rate, LET, oxygen, total dose, and fractionation significantly affect radiation-induced apoptosis.
- The review synthesizes current knowledge on apoptosis for radiation oncology applications.
Conclusions:
- Apoptosis is a critical process in cancer biology and a key target for cancer therapy.
- Understanding the interplay between radiation and apoptosis is essential for optimizing radiation oncology treatments.
- Further research into apoptotic pathways can lead to improved cancer management strategies.