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| Author(s): |
Katiana de Sales Junes
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2005-08-04 |
| Examining board members: |
Luisa Lina Villa;
Emmanuel Dias Neto;
Edison Luiz Durigon;
Jose Eluf Neto;
Anna Carla Renata Krepel Goldberg
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| Advisor: | Luisa Lina Villa |
| Abstract | |
Papillomavirus infection is the major cause for the development of cervical intraepithelial neoplasia (CIN) and invasive cervical cancer (ICC) in humano Epidemiological studies have demonstrated that persistence of the viral genome and development of cervical cancer are associated with specific molecular variants of high-risk human Papillomavirus (HPV). Human leukocyte antigen (HLA) molecules play a role in immune response and associations between HLA and IeC or HPV infections have been reported in several populations. We aimed to verify if HLA-DRB1 and DQB1 variability is related to ICC and CIN III in women from Belem, a population formed by the three main human ethnic groups and a high-risk area for this disease in Northem Brazil. We also investigated if there are differences in the HLA class II alleles distribution between women with ICC and CIN III that harbor different HPV-16 variants and women without cancer. HLA DRB1 and DQB1 were typed by PCR-SSO based methods in 95 ICC cases and 287 controls consisting of normal cytology from women attending cervical cancer screening programs in the same city. HPV-16 variants were typed by sequencing a PCR-amplified fragment of long control region (LCR) of the viral genome. The E6350 polymorphism was typed on the basis of a dot blot protocol targeting a specific nucleotide alteration in the position 350T→G of the E6 gene. The magnitude of associations was estimated by odds ratio (OR) and the respective 95% confidence interval (CI), adjusted for potential confounder factors. A positive association was found between ICC cases and DRB1*150 l-DQB1*0602, DRB1*04-DQB1*0301 and DRB1*1602-DQB1*0301 haplotypes. Conversely, DRB1*01-DQB1*05 showed a protective effect. DRB1*0804, DQB1*0402 showed negative association against HPV infection. DQB1*0502 and DRB1*15 were positively associated with HPV infection. Our study showed that positive association of DRB1*1501 and DRB1*1602 alleles may be attributed to AsianAmerican then European variants. Furthermore, the DRB1*1501 was found associated with both women carrying E6350G or E350T, however, a higher effect was observed for E6350T variants carriers. The positive association of DRB1*1602 was significant for women harboring E6350G then E6350T variants. These data are in agreement with ethnical component of the studied population as well as a higher oncogenic potential of certain HPV variants. Our results also suggest that the contribution of HLA class II alieles to the genetic susceptibility to ICC differs depending on the HPV-16 variants distribution in a given geographic and ethnic group. (AU) | |