Genomic amplification of the hTERC in cytologic specimens was significantly correlated with the severity of dysplasia. Patients with biopsy diagnoses of CIN or CA had significantly higher percentages of cells with extra copies of hTERC than did patients with a normal biopsy diagnosis. This test may be a complementary to regular screening methods to detect patients with high-grade lesions.
Several authors have shown that the percentage of cells with gain of hTERC copy number increased with the severity of dysplasia
[5, 6, 9–12, 18]. Heselmeyer et al. analyzed 57 thin-layer slides by FISH for the visualization of chromosomal copy number changes and found 63% of the HSIL( CIN2) lesions and 76% of the HSIL(CIN3) lesions showed extra copies of 3q
. In another paper, the same group designed a retrospective study set to 59 previously stained Pap smears, and proposed that gains of chromosome arm 3q play a crucial role in the progression of severe dysplasia/carcinoma in situ to invCA
. One study else on tissue sections also showed that 3q gain was detected in all of 12 cervical adenocarcinomas
. In our study, we analyzed a series of 114 Chinese women. Based on intensive test of exfoliated cell samples, our data show that extra copy numbers of hTERC present in 50% of CIN2, 81.5% of CIN3 and 100% of CA, no matter of what kind of histology type, of cases respectively. This result was similar to other studies in China
[18, 19]. The percentage of successfully hybridized samples was 96.49%, considerably higher than in the series of Pap smears
Hongxiu Han et al.
 suggested helpful biological markers would be in need of distinguishing CIN1 from CIN2/3. The expression of hTERT was evaluated as a potential marker of the high-grade premalignant CIN 2/3 lesions
. A recent study showed that overexpression of hTERC and hTERT together in vitro greatly induced telomerase activity and telomere length elongation, while stable overexpression of either hTERC or hTERT alone induced telomerase activity and telomere length elongation to a lesser extent
. Consistent with this study, several studies also highlighted the fact that both telomerase components restrict telomerase activity and telomere length in vitro, suggesting that the tumorigenic effects of hTERT overexpression are reliant on hTERC expression and in fact hTERT overexpression in an hTERC deficient background has anti-tumourigenic effects
[22–24]. Our data showed that in cervical intraepithelial lesions, levels of hTERC amplification were correlated with telomerase activity and hTERT expression. Furthermore, comparing with biopsy procedure, exfoliated cells samples used for hTERC testing in our study were easier to get from patients with a concurrent physical examination. From this point of view, we suggest there is the potential value of detecting hTERC gain by FISH method for distinguishing between lesions with and without progression to in situ or invasive malignancy of uterine cervix.
In a previous study by Sokolova I et al.
, 235 liquid-based preparation from cervical specimens were analyzed for aberrations of 3q26 using a commercially two-color FISH probe. They found in cases diagnosed as LSIL on cytology, the percentage of cells with gain of 3q26 did not differentiate those histologically diagnosed as high-grade dysplasia (CIN2/3) from those diagnosed as low-grade dysplasia (CIN1). Unfortunately, only a few cases had both HPV and FISH testing from one vial in that study. As shown in our study, we not only analyzed abnormal cells on exfoliated cervicovaginal preparations for gain of hTERC using a FISH probe similar to that used by Nancy P et al.
, but also each case had both HPV testing and concurrent biopsy results. In cases of LSIL, gain of 3q26 differentiated those lesions that had CIN2/3 on biopsy from those that did not.
It is not sufficient for HPV screening assays by itself in predicting the progression from atypical or mild dysplasia to high-grade lesion and subsequently to cancer, because this screening is lack of a high positive predictive value for the presence of dysplasia. Furthermore, a report indicated that some kind of cervical cancer, such as minimal deviation adenocarcinoma, was not associated with high-risk HPV
. Qisang et al.
 reported a significant positive correlation between positive hTERC gain and HR-HPV infection, histopathologic lesions (all P<0.01) in patients with cervical disease. Our study demonstrates that there are 23% HPV-infected positive cases in NNL, and 78.95% in CA group. From the gray-scale graph, we can see the HPV position ratio increase according to the severity of dysplasia. However, the predictive value of hTERC amplification test is much better than HPV test. Only 3.85% hTERC amplification positive ratio was observed in NNL group, and 100% in CA group, including two cases of minimal deviation adenocarcinoma. If combined these two tests together, it seems like much better than any one of them alone. In NNL group, there was not any case with both HPV and hTERC positive. From the clinical perspective, we hypothesize that hTERC gain, combining with testing of HPV infection by HC2, might have a very significant clinical application.
In summary, this study presents gain of hTERC in exfoliated cervicovaginal epithelial specimen and suggests a role of the factor in the biology of cervical cancer. Potential clinical usefulness of the hTERC FISH would be to distinguish patients with clinically significant cervical lesions from those that are insignificant lesions with a high risk of progression from those with a low risk of progression or an adjunct to cytology screening, especially in HPV-infection patients. However, more studies are needed to determine the application of hTERC gain in surveillance and prognosis of invasive cervical cancer.