| IntroductionCervical cancer is the most common gynecological malignant tumour, which occupies more than half of the malignant tumours of female reproductive system. Its mortality rate is at the first place of female malignant tumours. The etiopathogenisis of cervical cancer is quite complicated, and is generally considered to be of multiple factors. Many researches find that the generation of cervical cancer is closely related to activation of telomerase and proto-oncogene, inactivation of anti-oncogene.Telomerase is a kind of reverse transcriptase composed of RNA and proteins. It can synthesize telomere DNA with its own RNA as template, thus telomere avoids to shorten.As we know, because of the existence of extreme duplication problem, after each cell division, telomere will shorten a little, which will lead to apoptosis. Most human cells don't express telomerase, however, in certain factors, telomerase will be reactivated and precipitate cellular canceration.P53 gene locates at human chromosome 17(?) with a length of 20kb, which has 11 extrons and encodes a nuclear phosphoprotein(relative molecular weight 5．3*10D) composed of 393 amino acids. Usually, P53 gene has two types. One is wild, the other is mutant. The former is recognized as a kind of anti-oncogene, such as ras, myc and so on.which can induce terminal differentiation, maintain gene stable, trigger aging and apoptosis. While the latter has no function of anti-cancer, inversely, it can inhibit activity of wild P53 and precipitate cellular canceration. In this study, in order to identify the expression of telomerase and P53 gene in squamous carcinoma of the cervix(SCC) tissues, andmake clear their dependability and clinica significance, immunohistochemical streptavidi peroxidase(SP) method has been used to examine the expression of telomerase and P53 protein in tissues of normal cervical, SCC stage (?),(?) and (?).Materials and MethodsMaterials: 10 cases of normal cervical tissues and 60 SCC (including 23 cases ofstage (?), 20 cases of stage (?), and 17 cases of stage (?)) confirmed by pathological examination were collected. Meanwhile, clinical data of the patients were also collected, including clinical stages, pathological classification and lymphatic metastasis.Reagents: Rat anti-human P53 monoclonal antibody, rat anti-human telomerasemonoclonal antibody and SP immunohistochemical kit were applied without dilution from Maixin Biotech Ltd in Fujian.Instruments: Olympus light microscope (Japan), Ao microtome (U.S.A.), Pressurecooker( China), Incubator (China).Methods: All procedures were implemented according to the product illustration.Result judgement: Color reaction observed by light microscopy.1．The expression of P53 proteinBrown granula locating in cellular nuclear present positive cell. Less than 5% (-), 5%(?)50% (+); more than 50% (++). Positive slices contained (+) and (++), and then the ratio of the positive slices in all slices was calculated.2．The expression of telomeraseThe immunostaining of telomerase is localized on the cytoplasm . The results is divided into three group: Less than 5% (-), 5%(?)50% (+); more than 50% (++).Positive slices contained (+) and (++).3．Statistical analysis Statistical evaluation was performed using chi-square , Fishers exact probabilities or Spearman rank correlation .SPSS version 11．5 software was emplo-yed to analyze all datas . A P value less than 0．05 was considered statistically significant.Results1．The expression of telomerase among different groups of cervicaltissuesThe positive rate of telomerase in normal cervical tissues and cervical squamous cell carcinoma (SCC) was 0% and 93．3% (P <0．01) respectively. The positive rate of telomerase in SCC stage (?),(?) and (?) was 86．9%, 95% and 100% respectively. There were highly significant differences among them (P>0．05) . But they all had an increasing tendency.2．The expression of P53 protein among different groups of cervicaltissuesThe positive rate of P53 protein in normal cervical tissues and SCC was 0% and 78．3% respectively. There was highly significant differences between them (p<0．01) . The positive rate of P53 protein in SCC stage (?), (?) and (?) was 65．2%, 90% and 82．3% respectively. There were highly significant differences among them (P>0．05) .3．The relation of telomerase and P53 protein with the clinical andpathological characteristicsThe positive rate of telomerase and P53 protein in SCC tissues did not show significant correlation with clinical stage, pathological grades or lymphatic metastasis (P>0．05) , but they all had an increasing tendency.4．The relationship between the expression of telomerase and P53 incervical squamous cell carcinomaThe expression of telomerase was positively associated with that of P53 (r =0．346, p<0．05) .Conclusions1．Telomerase wasn(?)t expressed in normal cervical tissues, while significantly expressed in SCC, which indicated the activity of telomerase existed universally in SCC.2．Following the development of SCC, the positive rate of telomerase became higher. Thus telomerase could be used as an important tumor marker to screening SCC at an early stage.3．P53 protein wasn't expressed in normal cervical tissues, but the positive rate in SCC highly increased. This implied that the mutation of P53 gene was an important factor in SCC onset.4．The activity of telomerase within SCC with P53 positive is higher than that within SCC with P53 negative, which indicates that the expression of P53 protein is likely related with the active regulation of telomerase.
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