X-chromosomal inactivation skewing in blood cells is associated with early development of lung cancer in females
LI Gang, SU Qin, LIU Gui-qiu, GONG Li, ZHANG Wei, ZHU Shao-jun, ZHANG He-long, FENG Ying-ming, ZHANG Yu-hai. Department of Pathology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China
Objective To observe the relationship between skewed X-chromosomal inactivation (SXCI) and development of lung cancer in females. Methods DNA was isolated from peripheral blood cells from patients with primary lung cancer (n = 148) and control subjects (n =289). Exon 1 of androgen receptor ( AR) gene was amplified, with its products from different alleles resolved on denaturing polyacrylamide gels and visualized by silver staining. The corrected ratio ( CR) between products from different AR alleles before and after Hpa II pretreatment was calculated. All statistical tests were two-sided. Results With CR≥10 adopted as the criterion, SXCI was found more frequently in the younger patients (≤50 years; 7. 9% ) than in the controls of the same age group (1.2%; P = 0. 046). The SXCI frequency, however, were not significantly different between the old patients ( 50 years; 4. 5% ) and the controls of the same age group (5.4% ; P=0.488). Whether taking CR≥3 or CR≥10 as the criteria, the average ages of the patients with SXCI were more than 10 years younger than those without SXCI ( P 0. 05 ) . Conclusion SXCI in blood cells is associated with early development of lung cancer in females.