GSTM1, GSTT1, and NQO1 polymorphisms in cervical carcinogenesis.

The aim of the study is to investigate the clinical significance of glutathione-S-transferase GSTM1, GSTT1, and NQO1 c.609C>T (rs1800566) genetic polymorphisms in cervical carcinogenesis. GSTM1, GSTT1, and NQO1 polymorphisms together with human papillomavirus (HPV) types were examined in a total of 192 cervical smear in exfoliated cervical cell samples using polymerase chain reaction (PCR) system and real-time polymerase chain reaction (PCR) system. The 19 patients with high-grade squamous intraepithelial lesion had statistically higher frequency of null GSTT1 genotype than 9 with low-grade squamous intraepithelial lesion (LSIL) among the 67 patients with high-risk HPV (P = 0.024). The 24 patients with HSIL had also statistically higher frequency of NQO1 (CT+TT) genotype than 14 with LSIL among the 67 patients with high-risk HPV (P = 0.024). GSTT1 null and NQO1 genotype in cervical cell samples may be associated with more severe precancerous lesions of the cervix in a Japanese population.

First trial of cervical cytology in healthy women of urban Laos using by self-sampling instrument.

Cervical cancer is the most common cancer in Laos women and a screening programme, even with the PAP smear test (PAP test), has yet to be established for routine use. The Pap test is accepted as the most appropriate for cervical cancer screening in some settings but it is not commonly available in Laos hospitals, because there are few cytopathologists and gynecologists have little experience. As a pilot program, seminars for the PAP test were given in 2007 and 2008, and then PAP tests were carried out using self-sampling instrument (Kato's device) with 200 healthy volunteers in Setthathirath hospital, Laos, in 2008. The actual examination number was 196, divided into class I 104 (53.1%), class II 85 (43.3%), class IIIa 4 (2.0%), class IIIb 1 (0.5%), and class V 1 (0.5%) by modified Papanicolau classification. Four cases had menstruation. There were 6 cases with epithelial cell abnormalities including malignancy. There were 7 cases with fungus and 2 cases with trichomonas in Class II. More than 70% volunteers felt comfortable with the Kato's device and wanted to use it next time, because of the avoidance of the embarrassment and a low cost as compared with pelvic examination by gynecologists. This first trial for PAP test for healthy Laos women related to a hospital found three percent to have abnormal cervical epithelial cells. Therefore, this appraoch using a self-sampling device suggests that it should be planned for cervical cancer prevention in Laos.

Genetic Polymorphism of Cancer Susceptibility Genes and HPV Infection in Cervical Carcinogenesis.

It is widely accepted that specific human papillomavirus (HPV) types are the central etiologic agent of cervical carcinogenesis. However, a number of infected women do not develop invasive lesions, suggesting that other environmental and host factors may play decisive roles in the persistence of HPV infection and further malignant conversion of cervical epithelium. Although many previous reports have focused on HPV and environmental factors, the role of host susceptibility to cervical carcinogenesis is largely unknown. Here, we review the findings of genetic association studies in cervical carcinogenesis with special reference to polymorphisms of glutathione-S-transferase (GST) isoforms, p53 codon 72, murine double-minute 2 homolog (MDM2) gene promoter 309, and FAS gene promoter -670 together with HPV types including our recent research results.

Germline polymorphisms of glutathione-S-transferase GSTM1, GSTT1 and p53 codon 72 in cervical carcinogenesis.

The clinical significance of glutathione-S-transferase GSTM1, GSTT1 and p53 codon 72 polymorphisms in cervical carcinogenesis was investigated. Germline polymorphisms of GSTM1, GSTT1 and p53 codon 72 together with human papillomavirus (HPV) types were examined in a total of 457 blood and cervical smear samples from normal healthy women and the patients with premalignant and malignant cervical lesions. The 167 patients with low-grade squamous intraepithelial lesion (LSIL), 49 with high-grade SIL (HSIL) and 83 with squamous cell carcinoma (SCC) had significantly higher frequency of high-risk HPV than 158 controls. The 49 patients with HSIL and 83 with SCC had statistically higher frequency of null GSTT1 genotype than 158 controls. There was an increased odds ratio for null GSTT1 genotype in HSIL and SCC cases compared with controls among 191 patients with high-risk HPV. The 67 cases with HPV types 16 and/or 18 had higher frequency of the GSTT1 null genotype than 186 with other types of HPV. There was no statistical difference in the polymorphic frequency of GSTM1 and p53 codon 72 genotypes between SILs and controls with or without high-risk HPV. These results suggest that GSTT1 null genotype may increase the risk of cervical cancer particularly in the cases with high-risk HPV types in a Japanese population.

MDM2 SNP 309 human papillomavirus infection in cervical carcinogenesis.

OBJECTIVE: To investigate the biological significance of single nucleotide polymorphism (SNP) at murine double-minute 2 homolog (MDM2) promoter 309 in cervical carcinogenesis. METHODS: SNP at MDM2 promoter 309 (T/G) together with human papillomavirus (HPV) types was examined in a total of 195 cervical smear samples and 8 human cervical squamous carcinoma cell lines using two independent PCR assays and PCR-RFLP techniques. RESULTS: Forty-one patients with high-grade squamous intraepithelial lesion (HSIL) had higher frequency of high-risk HPV than 102 with low-grade SIL (LSIL) and 52 controls. There was an increased OR (8.88; CI=2.34-33.63; P=0.003) for TG+GG genotype in HSIL cases compared to controls among 68 patients with high-risk HPV. Twenty-one cases with HPV types 16 and/or 18 had significantly higher frequency of the TG+GG genotype and G allele than 47 with other types of high-risk HPV. Seven of 8 cervical carcinoma cell lines also showed TG or GG genotype. CONCLUSION: MDM2-SNP309 (T/G) and high-risk HPV infection may be closely associated with cervical carcinogenesis in a Japanese population.

Polymorphisms of p53 codon 72 and MDM2 promoter 309 and the risk of endometrial cancer.

Genetic polymorphisms of p53 and its negative regulator murine double minute 2 homolog (MDM2) have been shown to be closely associated with tumorigenesis in a variety of human cancers. In the present study, single nucleotide polymorphism (SNP) at p53 codon 72 and MDM2 promoter 309 was examined for germline DNA samples from 102 endometrial cancer cases and 95 controls using polymerase chain reaction-based fragment analysis. There were no significant differences in the genotype and allele prevalence between control subjects and endometrial cancer patients for p53 codon 72. The GG genotype frequency of MDM2-SNP309 was statistically higher in endometrial cancer patients than that in normal healthy women when compared with the TG genotype (P= 0.0088). However, no statistically significant differences were found between the TT and TG or GG genotype frequencies and allele prevalence. Interestingly, the combination of the homozygous Arg/Arg genotype of p53 codon 72 and homozygous GG genotype of MDM2 SNP309 polymorphisms was significantly associated with the risk of endometrial cancer (odds ratio = 3.28, 95% confidence interval = 1.13 to 9.53, P= 0.0212). The homozygous variants of wild p53 codon 72 and mutant MDM2 promoter 309 may cooperatively increase the risk of endometrial cancer in a Japanese population.

Murine double-minute 2 homolog single nucleotide polymorphism 309 and the risk of gynecologic cancer.

A functional T to G germline polymorphism in the promoter region of murine double-minute 2 homolog single nucleotide polymorphism 309 (MDM2-SNP309) has been reported to profoundly accelerate tumor formation, suggesting that it may also represent a powerful cancer predisposing allele. In this study, MDM2-SNP309 was examined in a total of 400 blood samples from 108 normal, 88 cervical, 119 endometrial and 85 ovarian cancer cases using two independent polymerase chain reaction assays for each allele. When the MDM2-SNP309 genotype was classified into two subgroups of TT+TG and GG, the GG genotype was associated with an increased risk for the development of endometrial cancer (odds ratio [OR]= 1.91, 95% confidence interval [CI] = 1.05 to 3.47) compared with the TT+TG genotype (P = 0.0353). The G allele also increased the risk of endometrial cancer (OR = 1.20, 95% CI = 0.83 to 1.74) compared with the T allele, but no statistical difference was found (P = 0.3333). The homozygous GG genotype was also associated with postmenopausal status and type I endometrial cancer (P = 0.0306 and 0.0326, respectively). There was no significant difference in the genotype or allele prevalence between control subjects and cervical or ovarian cancer patients. These results suggest that homozygous GG genotype of MDM2-SNP309 may be a risk factor for postmenopausal and type I endometrial cancer in a Japanese population.

Germline polymorphism of cancer susceptibility genes in gynecologic cancer.

The multifactorial process of carcinogenesis involves mutations in oncogenes, or tumor suppressor genes, as well as the influence of environmental etiological factors. Common DNA polymorphisms in low penetrance genes have emerged as genetic factors that seem to modulate an individual's susceptibility to malignancy. Genetic studies, which lead to a true association, are expected to increase understanding of the pathogenesis of each malignancy and to be a powerful tool for prevention and prognosis in the future. Here, we review the findings of genetic association studies of gene polymorphisms in gynecologic cancer with special reference to glutathione-S-transferase, FAS/CD95 and p53 genes including our recent research results.

Mutational analysis of the BRAF gene in human tumor cells.

Genes of the RAF family, which mediate cellular responses to growth signals, encode kinases that are regulated by RAS and participate in the RAS, RAF, mitogen/extracellular signal-regulated kinase, extracellular signal-regulated kinase and mitogen-activated protein kinase pathway. As BRAF is a serine/threonine kinase that is commonly activated by somatic point mutation, it may provide possible diagnostic and therapeutic targets in human malignant tumors. We analyzed exon 15 of the BRAF gene for mutations in 58 lung, 12 breast, six kidney, 14 cervical, four endometrial and 10 ovarian carcinoma cell lines by PCR-SSCP and direct sequencing. The T1796A transversion was found in one (2.9%) of 34 small cell lung carcinoma and one (8.3%) of 12 breast carcinoma cell lines, resulting in a valine-to-glutamate substitution at residue 599 (V599E). One (4.2%) of 24 non-small cell lung carcinoma cell line showed the C1786G transversion, leading to a leucine-to-valine substitution at residue 596 (L596V). No BRAF point mutations were found in any of the other cell lines examined. Our present results suggest that BRAF may not be a frequent target of mutations involved in the pathogenesis of human lung, breast, kidney, cervical, endometrial and ovarian carcinomas.

Fas gene promoter -670 polymorphism (A/G) is associated with cervical carcinogenesis.

OBJECTIVE: To investigate the biological significance of single nucleotide polymorphism (SNP) at Fas gene promoter in cervical carcinogenesis. METHODS: SNP at -670 of Fas gene promoter (A/G) together with human papillomavirus (HPV) types were examined in a total of 279 cervical smear samples and 8 human cervical squamous carcinoma cell lines using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) techniques. RESULTS: 49 patients with high-grade squamous intraepithelial lesion (HSIL) had higher frequency of high-risk HPV and GA + GG genotype than 167 with low-grade SIL (LSIL) and 63 controls. G allele frequency was also higher in HSIL than in LSIL and controls. There was an increased OR (6.00; CI, 1.32-27.37; P = 0.021) for GA + GG genotype in HSIL cases compared to controls among 96 patients with high-risk HPV. 7 of 8 cervical carcinoma cell lines also showed GA or GG genotype. CONCLUSION: Fas gene promoter -670 polymorphism (A/G) may be closely associated with cervical carcinogenesis in a Japanese population.

Glutathione-S-transferase and p53 polymorphisms in cervical carcinogenesis.

OBJECTIVE: To investigate the clinical significance of glutathione-S-transferase GSTM1, GSTT1 and p53 codon 72 polymorphisms in cervical carcinogenesis. METHODS: GSTM1, GSTT1 and p53 codon 72 polymorphisms together with human papillomavirus (HPV) types were examined in a total of 198 cervical smear samples using multiplex polymerase chain reaction (PCR) and PCR restriction fragment length polymorphism (RFLP) techniques. RESULTS: Forty-two patients with high-grade squamous intraepithelial lesion (HSIL) had higher frequency of high-risk HPV and null GSTT1 genotype than 102 with low-grade SIL (LSIL) and 54 controls. Thirty-one patients with HSIL had also statistically higher frequency of null GSTT1 genotype than 28 with LSIL among 69 patients with high-risk HPV. There was no statistical difference in p53 Arg, Arg/Pro and Pro genotypes between SILs and controls with or without high-risk HPV. CONCLUSION: GSTT1 null genotype in cervical cell samples may be associated with more severe precancerous lesions of the cervix in a Japanese population. The p53 codon 72 polymorphism is unlikely to be related to HPV status and the onset of cervical cancer.

Experience with a self-administered device for cervical cancer screening by Thai women with different educational backgrounds.

BACKGROUND: This descriptive study was carried out to test the acceptability of a self-administered device for cervical cancer screening and assess certain risk factors in relation to the cancer in two districts of Khon Kaen province in Northeast Thailand. METHODS: A total of 354 women from the villages were selected (including 143 teachers from secondary and primary schools; 24 health officers from the rural health centres, and 37 nurses from the University Hospital, Khon Kaen University). The Kato device was introduced and used by the women, who were then asked to give their opinion on its usage. RESULTS: The Kato device was generally well accepted by the women. However, many of those with a higher educational background were more sceptical towards the device than their counterparts from the villages. CONCLUSIONS: A suitable approach to strengthen the control of cervical cancer in the rural areas of Thailand might be to introduce the Kato device as an integral part of primary health care. The introduction of the device should go along with health education on the importance of avoiding infection with the papilloma viruses. This message should be transmitted to both females and males.

A comparison of cytology with Pap smears taken by a gynecologist and with a self-sampling device.

Cervical cancer is the most common cancer in Thai women and as yet screening programmes are minimally effective. The Pap smear is the test accepted to be most appropriate for cervical cancer screening so far. One of the main reasons why women do not come to have Pap smear done is "shyness", which weakens compliance with recommendations to undergo Pap smear with pelvic examination. The self-administered device by the Kato method was established to overcome this problem and the present study was carried out to confirm the adequacy of the specimens obtained with this technique in comparison with specimens collected by gynecologists. Two hundred women were invited to participate in the study voluntarily. Each was allocated to have a Pap smear conducted by a gynecologist and then instructed to produce a self-obtained smear using Kato's device. The cytology results of Pap smears from both methods were compared to test for agreement using Kappa statistics. There was agreement between the adequacy of smears collected by gynecologists and those self-sampled with the percentage agreement of 96.5% and a Kappa score of 0.43 (95% CI 0.33-0.54, P<0.001). There were 8 cases detected as epithelial cell abnormalities from the cervical cells collected by gynecologists and also with the self-administered technique. Good agreement for detection of cellular changes was found with a percentage of 78.0% and the Kappa's score was 0.61 (95% CI 0.46-0.76, P<0.001). The results from this study provide convincing evidence that the self-administered device can be an alternative choice for women who are too shy to undergo pelvic examination or even for those who have limited time to visit health care centers or doctors to have a Pap smear test.