Correlation between radiation-induced telomerase activity and human telomerase reverse transcriptase mRNA expression...

Area of Science:

• Molecular Biology
• Radiation Biology
• Cell Biology

Background:

• Telomerase plays a crucial role in maintaining telomere length.
• Understanding telomerase regulation is vital for cancer research and therapy.
• Ionizing radiation is a common cancer treatment modality with complex cellular effects.

Purpose of the Study:

• To quantify human telomerase reverse transcriptase (hTERT) mRNA expression.
• To measure telomerase activity (TA) in HeLa cells.
• To correlate hTERT mRNA expression with TA following ionizing radiation exposure.

Main Methods:

• HeLa cells were irradiated with varying doses (5-20 Gy) of 6 MV photon radiation.
• Telomeric repeat amplification protocol (TRAP) assay was used to measure TA.
• Real-time reverse transcriptase polymerase chain reaction (RT-PCR) quantified hTERT mRNA expression.
• Cell viability was assessed using the MTT assay.

Main Results:

• Cell viability decreased with increasing radiation dose.
• Both TA and hTERT mRNA expression significantly increased within 24 hours post-irradiation, peaking at approximately double the control levels.
• The temporal response of telomerase activation varied with radiation dose.
• A dose-dependent G2/M cell cycle arrest was observed 24 hours post-irradiation.

Conclusions:

• A significant correlation exists between TA and hTERT mRNA expression post-irradiation.
• Ionizing radiation induces cell cycle-dependent modifications in hTERT mRNA expression, particularly within the first 24 hours.