Investigation of Stem-like Cells Role in Regional Radiosensitivity of the LungOla M Maria1,2,3* Ahmed M Maria4 Norma Ybarra1,3 Krishinima Jeyaseelan1 Sangkyu Lee1, Jessica Perez1, Shirley Lehnert1,3, Lyne Kharbotly5, Sergio Faria3, Monica Serban1, Jan Seuntjens1,3 and Issam El Naqa1,3
- *Corresponding Author:
- Ola M Maria
Department of Oncology, Medical Physics Unit, McGill University
Montreal General Hospital, Radiation Oncology Division
1650 Cedar Ave, Québec, Canada
Tel: +15149341934 (Extn.: 44157)
E-mail: [email protected]
Received date: July 15, 2015; Accepted date: August 04, 2015; Published date: August 06, 2015
Citation: Maria OM, Maria AM, Ybarra N, Jeyaseelan K, Lee S, et al. (2015) Investigation of Stem-like Cells Role in Regional Radiosensitivity of the Lung. J Stem Cell Res Ther 5:298.doi:10.4172/2157-7633.1000298
Copyright: © 2015 Maria OM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Objective: Lung is a complex organ with puzzling patterns of radiosensitivity, depending on both the volume and the region of the lung irradiated. In this study, we aimed to investigate stem-like cells distribution in lung lobes and their potential role in regional radiosensitivity and incidences of radiation-induced lung damage (RILD).
Methods: Fifteen male Sprague-Dawley rats (8 weeks, 200–250 g) were grouped into two groups: control (sham irradiated, n=6) and treatment (irradiated, n=9). The treatment group received 3 regimens of whole thorax x-ray doses and divided into 3 subgroups: 12 Gy (n=3), 16 Gy (n=3) and 20 Gy (n=3), and monitored for 16 weeks post-radiation. Immunohistochemistry techniques were employed to localize and quantify the distribution of type II pneumocytes, Clara cells and cluster of differentiation (CD) positive stem cells (CD24+, CD44v6+, CD73+), in the upper, middle and lower lobes of the right lung in all rats.
Results: The upper lobe was found to harbour more stem-like cells compared to the middle/lower lobes (p < 0.05). The middle and lower lobes contained comparable percentages of different stem-like cells. All stem-like cells tested were distributed unsystematically in the lung tissue with no specific identifiable niches.
Conclusion: The upper lobe harbours more population of stem-like cells compared to the lower lobe, this might explain the variation in regional radiosensitivity, with the lower lung lobe being more prone to radiation injury compared to the upper lobe. No specific stem cell niche could be identified in our study. These results may support the development of new-targeted radioprotection strategies to reduce incidences of RILD during radiotherapy.