Reduced expression of members of the MHC-I antigen processing machinery in ethnic Uighur women with cervical cancer in the Xinjiang region of China

Objective Cervical cancer is a major cause of mortality in Uighur women compared with Han women in the Xinjiang region of China. Although a reduction in the class I major histocompatibility complex (MHC-I) antigen processing machinery (APM) is associated with the development of cervical cancer, the MHC-I APM has not been studied in this particular group of women, who have the highest incidence rate of cervical cancer in China. Study Design We used immunohistochemical staining and polymerase chain reaction amplification of viral DNA from infection with the human papilloma virus (HPV) to study the expression of members of the MHC-I APM in cervical cancer sections collected from Uighur and Han women and in cervicitis samples from age-matched counterparts. Results Expression of the molecules of interest was compared between two ethnic groups, and expression of transporter associated with antigen processing 1 and 2, heat shock protein 90, and calnexin were found to be reduced even more significantly in Han women with cervical cancer than in Uighur women with same disease. However, compared with Han women, Uighur women had a higher rate of infection with HPV 16. Conclusions The MHC-I APM were reduced in cervical cancer, with heterogeneity in the two ethnic groups. The reduction was more pronounced in Han women, who less frequently had HPV 16 infection, suggesting possible differences in the roles of members of the MHC-I APM and in the mechanisms of cervical cancer development in these two ethnic groups despite residence in the same region of China.