The significance of proliferating cell nuclear antigen in human trophoblastic disease: an immunohistochemical study

Trophoblastic infiltration in tubal pregnancy evaluated by immunohistochemistry and correlation with variation of Beta-human chorionic gonadotropin

Objective. To evaluate trophoblastic cell proliferation and angiogenesis in tubal pregnancy assessed by immunohistochemical study and their correlation with an average variation of β-hCG in an interval of 48 hours before surgery. Methods. A prospective study was conducted on 18 patients with a diagnosis of tubal pregnancy. The patients were divided into two groups of ectopic pregnancy of which 11 showed rise of β-hCG levels and 7 patients showed declining β-hCG levels in an interval of 48 hours prior to surgery. Trophoblastic cell proliferation and angiogenesis were assessed by Ki-67 and VEGF, respectively. Trophoblastic cell proliferation was assessed by Ki-67 and was classified into three groups (grade I: less than 1/3 of stained nuclei, grade II: 1/3 to 2/3 of the stained nuclei, and grade III: more than 2/3 of the nuclei stained). The cases analyzed for VEGF were divided into three groups (grade I: less than 1/3 of the stained cytoplasm; grade II: 1/3 to 2/3 of the stained cytoplasm; grade III: more than 2/3 of the stained cytoplasm). Statistical analysis was performed using the chi-square, ANOVA, and Kruskal-Wallis tests. Results. The mean variation in the serum β-hCG levels in 48 hours in tubal pregnancy patients correlated with trophoblastic cell proliferation assessed by Ki-67 and showed a decline of 13.46% in grade I, a rise of 45.99% in grade II, and ascension of 36.68% in grade III (P = 0.030). The average variation in the serum β-hCG in 48 hours, where angiogenesis was evaluated by VEGF, showed a decline of 18.35% in grade I, a rise of 32.95% in grade II, and ascension of 37.55% in grade III (P = 0.047). Conclusions. Our observations showed a direct correlation of increased levels of serum β-hCG in 48h period prior to surgery with higher trophoblastic cell proliferation assessed by Ki-67 and angiogenesis assessed by VEGF in tubal pregnancy.

Novel levamisole derivative induces extrinsic pathway of apoptosis in cancer cells and inhibits tumor progression in mice

Background

Levamisole, an imidazo(2,1-b)thiazole derivative, has been reported to be a potential antitumor agent. In the present study, we have investigated the mechanism of action of one of the recently identified analogues, 4a (2-benzyl-6-(4′-fluorophenyl)-5-thiocyanato-imidazo[2,1-b][1], [3], [4]thiadiazole).

Materials and Methods

ROS production and expression of various apoptotic proteins were measured following 4a treatment in leukemia cell lines. Tumor animal models were used to evaluate the effect of 4a in comparison with Levamisole on progression of breast adenocarcinoma and survival. Immunohistochemistry and western blotting studies were performed to understand the mechanism of 4a action both ex vivo and in vivo.

Results

We have determined the IC₅₀ value of 4a in many leukemic and breast cancer cell lines and found CEM cells most sensitive (IC₅₀ 5 µM). Results showed that 4a treatment leads to the accumulation of ROS. Western blot analysis showed upregulation of pro-apoptotic proteins t-BID and BAX, upon treatment with 4a. Besides, dose-dependent activation of p53 along with FAS, FAS-L, and cleavage of CASPASE-8 suggest that it induces death receptor mediated apoptotic pathway in CEM cells. More importantly, we observed a reduction in tumor growth and significant increase in survival upon oral administration of 4a (20 mg/kg, six doses) in mice. In comparison, 4a was found to be more potent than its parental analogue Levamisole based on both ex vivo and in vivo studies. Further, immunohistochemistry and western blotting studies indicate that 4a treatment led to abrogation of tumor cell proliferation and activation of apoptosis by the extrinsic pathway even in animal models.

Conclusion

Thus, our results suggest that 4a could be used as a potent chemotherapeutic agent.

Histopathological diagnosis of hydatidiform mole: contemporary features and clinical implications

Gestational trophoblastic neoplasia (GTN) encompasses several entities including complete (CHM) and partial (PHM) hydatidiform mole (HM), malignant choriocarcinoma, and placental-site trophoblastic tumor. HMs are genetically abnormal, nonviable conceptions, which are associated with significantly increased risk for development of complications due to persistence of abnormal trophoblast (persistent GTN; pGTN), which occurs following 15% of CHM and 0.5% of PHM. Diagnostic histological features of HM are present in the first trimester but these features differ from those traditionally described in the later second trimester. The characteristic morphological findings of early HM include aspects of villous dysmorphism and abnormal villous trophoblast hyperplasia, with other specific features allowing reliable distinction between CHM and PHM. Optimal management of molar disease depends on its early histological identification and subsequent surveillance by measurement of maternal human chorionic gonoadotropin (hCG) for detection of pGTN based on rising or plateuing hCG levels such that early effective treatment is possible.

Effect of all-trans retinoic acid on tissue dynamics of choriocarcinoma cell lines: an organotypic model

BACKGROUND

All-trans retinoic acid (ATRA) is a natural vitamin A derivative that has a profound effect on the regulation of cell growth, differentiation and death.

AIM

To investigate the tissue dynamic and cellular invasion effects of ATRA in choriocarcinoma (CCA), an aggressive trophoblastic tumour, by using a three-dimensional organotypic culture model system and cell invasion assay, respectively.

METHODS

An organotypic culture model of two CCA cell lines, JAR and JEG, was established. The effects of 1 microM ATRA on proliferation, differentiation and apoptosis on this CCA model were assessed by morphological assessment of the mitotic and apoptotic figures as well as by Ki-67 and caspase-related M30 cytoDeath antibody immunohistochemistry and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) assay. The effect of ATRA on p53 and its regulated protein product, WAF1/Cip1, was also evaluated with DO7 and p21(WAF1) antibodies, respectively. Moreover, the effect of ATRA on cellular (CCA) invasion was also investigated with Cell Invasion Kit on the JEG cell line.

RESULTS

ATRA was found to induce marked apoptosis in organotypic cultures of both cell lines, as evidenced by increased M30-positive cells (p<0.0001) and increased TUNEL-positive cells (p<0.0001) in treated cultures; to decrease proliferation, as evidenced by decreased Ki-67-positive cells (p<0.0001); and to decrease p53-DO7 immunoreactivity (p<0.0001) and increase p21(WAF1) (p<0.0001) immunoreactivity. 1.5 microM ATRA was found to effectively inhibit JEG cell invasion in the cell invasion assay.

CONCLUSION

ATRA treatment was found to inhibit invasion and proliferation and enhance apoptosis, probably by the activation of caspases and induction of differentiation. ATRA and synthetic retinoids may be alternative agents for the treatment of CCA.

Id helix-loop-helix proteins are differentially expressed in gestational trophoblastic disease

AIMS

To assess the expression of Id proteins in trophoblastic tissues and to correlate this with clinical parameters, proliferative and apoptotic indices as well as to related oncogene expression.

METHODS AND RESULTS

Immunohistochemistry for Id1, Id2, Id3 and Id4 was performed on 83 trophoblastic tissues including 17 normal first-trimester placentas, seven term placentas, 47 hydatidiform moles (HM), and 12 spontaneous miscarriages. The four Id proteins were predominantly expressed in the villous and implantation site intermediate trophoblast. Expression of Id1 in HM was significantly higher than that in normal placenta (P = 0.0006) and spontaneous miscarriage (P = 0.0001) but did not correlate with subsequent development of gestational trophoblastic neoplasia (GTN). Id1 expression correlated with the proliferation index as assessed by MCM7 (P = 0.003) and Ki67 (P = 0.017) and with the apoptotic activity assessed by TUNEL (P = 0.001) and M30 CytoDeath antibody (P = 0.013). Moreover, the expression of Id1 correlated with the expression of p53 (P = 0.004), p21(WAF1) (/CIP1) (P = 0.003) but not with p16 (P = 0.107).

CONCLUSIONS

Id proteins may play a role in the regulation of proliferative and apoptotic activity in trophoblastic tissue and are potentially useful in differentiating molar and non-molar gestation, but are not helpful in predicting GTN.

Mcl-1 expression in gestational trophoblastic disease correlates with clinical outcome

BACKGROUND

Hydatidiform moles (HMs) are abnormal pregnancies with a propensity for developing persistent disease in the form of gestational trophoblastic neoplasia (GTN), which requires chemotherapy. In previous studies, the authors demonstrated that low apoptotic activity was correlated with the progression of HM to GTN, and they hypothesized that some apoptosis-related genes may determine this progression.

METHODS

The differential expression of apoptotic genes in HMs that subsequently developed into GTN was compared with the same expression in HMs that spontaneously regressed using a human apoptosis array; then, the expression was evaluated with real-time quantitative polymerase chain reaction analysis and immunohistochemistry using 54 clinical samples from patients with HMs who had follow-up data available.

RESULTS

Using an apoptosis array, greater expression of Mcl-1, which is an antiapoptotic gene, was detected in HMs that subsequently developed into GTN. It was confirmed that the levels of Mcl-1 RNA expression (P = 0.017) and Mcl-1 protein expression (P < 0.001) in HMs that developed into persistent disease and required chemotherapy were significantly greater compared with the levels in HMs that regressed. Moreover, Mcl-1 immunoreactivity, which was detected predominantly in cytotrophoblasts, was correlated with the apoptotic index, as assessed with M30 cytoDeath immunohistochemistry, which is a good indicator of apoptotic events in the early-stage disease.

CONCLUSIONS

The current results demonstrated that Mcl-1, as identified by a cyclic DNA array, may play a role in the pathogenesis of HMs and may have potential as a useful marker for predicting the clinical behavior of HMs.

Does fetal gender affect cytotrophoblast cell activity in the human term placenta? Correlation with maternal hCG levels

BACKGROUND

Pregnant women with female fetuses have higher maternal serum human chorionic gonadotropin (hCG) levels than pregnant women with male fetuses. Ki-67, a cell proliferation and activity marker, is confined mostly in the nuclei of villous cytotrophoblasts of the human placenta. In this study, we examined the effect of fetal gender on the cytotrophoblast cell activity in human term placenta, with special regard to maternal serum and cord blood hCG levels.

METHODS

Thirty-four uncomplicated, singleton, term pregnancies (17 male and 17 female fetuses) were recruited in the study. hCG was measured in maternal peripheral serum and umbilical cord blood. Placental samples were collected in each patient during the cesarean section. Cytotrophoblast cell activity was measured by using immunohistochemistry for Ki-67 antigen. Ki-67 staining index values of the cytotrophoblasts were compared between the female and male placentas.

RESULTS

Maternal serum and cord blood hCG levels were higher in pregnant women with female fetuses than in those carrying male fetuses. There was no sex difference in Ki-67 immunostaining rates of the cytotrophoblast cells. There was no correlation between maternal serum and cord blood hCG levels and Ki-67 staining index values of the cytotrophoblast cells.

CONCLUSIONS

The difference in maternal serum and cord blood hCG levels in correlation with the fetal gender is not associated with cytotrophoblast cell activity in the human term placenta. The gender of the fetus does not seem to affect the regulation of cytotrophoblast cell proliferation.

Minichromosome maintenance protein 7 expression in gestational trophoblastic disease: correlation with Ki67, PCNA and clinicopathological parameters

AIMS

To assess the proliferative activity of gestational trophoblastic disease (GTD) using one of the novel proliferation markers (MCM7) and to determine its prognostic value in hydatidiform mole (HM).

METHODS AND RESULTS

Immunohistochemical staining for MCM7 was performed on 122 samples of paraffin-embedded trophoblastic tissues including 22 normal first-trimester placentas, 12 term placentas, 12 spontaneous miscarriages (SM), 21 partial moles (PM), 44 complete hydatidiform moles (CM), and 11 choriocarcinomas (CCA). The correlations between the proliferative indices assessed by MCM7, proliferating cell nuclear antigen (PCNA) and Ki67 (MIB1) immunoreactivity as well as clinical progress were assessed. MCM7 immunoreactivity was found predominantly in the nuclei of cytotrophoblast and intermediate trophoblast and decreased with placental maturation. MCM7 expression was highest in CCA, followed by CM, PM, normal first-trimester placenta, SM and term placenta. MCM7 index was significantly higher in PM and CM than in SM (P = 0.007, P < 0.001) but not between PM and CM themselves (P = 0.560). Eighteen of the 65 patients with HM developed persistent trophoblastic disease (PTD) requiring chemotherapy. There was no significant difference in MCM7 indices between the patients who developed PTD and those who did not (P = 0.312). MCM7 indices correlated well with Ki67 (P = 0.002) but not with PCNA (P = 0.054) indices. MCM7 indices demonstrated less variability than PCNA and Ki67 and may be a better proliferation marker than the latter two.

CONCLUSIONS

We conclude that MCM7 is useful in differentiating molar and non-molar gestations but is not helpful in discriminating PM from CM or in predicting PTD.

Histopathological diagnosis of partial and complete hydatidiform mole in the first trimester of pregnancy

The diagnosis of molar pregnancy is a continuing diagnostic problem for many practicing histopathologists who are required to examine specimens of products of conception, particularly since changes in gynecological management in recent years have resulted in uterine evacuation at earlier gestations. The aim of this review is to provide practical, up-to-date, diagnostically useful information regarding the histological diagnosis of molar disease in early pregnancy. Pathophysiological issues relevant to molar pregnancies, such as genetic abnormalities, will be briefly summarized, but nonhistopathological aspects of molar disease will not be covered in detail in this review.

Expressions of proliferation markers (Ki-67, proliferating cell nuclear antigen, and silver-staining nucleolar organizer regions) and of p53 tumor protein in gestational trophoblastic disease

OBJECTIVE

This study was undertaken to determine whether the expressions of 3 proliferation markers (Ki-67, proliferating cell nuclear antigen, and silver-staining nucleolar organizer regions) and of p53 tumor protein could differentiate spontaneous abortions from gestational trophoblastic diseases and also discriminate among gestational trophoblastic disease subgroups.

STUDY DESIGN

Twenty-two partial hydatidiform moles, 17 complete hydatidiform moles, 6 invasive hydatidiform moles, and 20 nonhydropic spontaneous abortions (control group) were evaluated by means of immunohistochemical techniques with antibodies to Ki-67, proliferating cell nuclear antigen, and p53. One-step silver staining was used to detect silver-staining nucleolar organizer regions.

RESULTS

The expressions of Ki-67, proliferating cell nuclear antigen, silver-staining nucleolar organizer regions, and p53 were significantly higher in the gestational trophoblastic disease group than in the control group. The results of linear discriminant analysis showed that silver-staining nucleolar organizer region count had the highest sensitivity and specificity (93.3% and 100%, respectively) for distinguishing gestational trophoblastic disease from spontaneous abortion. Sensitivity and specificity for discriminating gestational trophoblastic disease from spontaneous abortion increased to 100% when all four markers were used together. Proliferating cell nuclear antigen was found to be the best discriminating variable for differentiating among gestational trophoblastic disease subgroups.

CONCLUSION

Our findings suggest that expressions of Ki-67, proliferating cell nuclear antigen, silver-staining nucleolar organizer regions, and p53 may aid in the diagnosis of gestational trophoblastic diseases. These fairly rapid, simple, and economic techniques could serve as a useful adjunct to conventional methods in the diagnosis of gestational trophoblastic diseases.

Apoptotic activity in gestational trophoblastic disease correlates with clinical outcome: assessment by the caspase-related M30 CytoDeath antibody

AIMS

The objective of this study was to assess apoptotic activity in gestational trophoblastic disease (GTD) and its prognostic value in hydatidiform mole (HM).

METHODS AND RESULTS

Expression of the specific caspase cleavage site within cytokeratin 18 was assessed immunohistochemically using the monoclonal antibody M30 CytoDeath in 12 spontaneous abortions, 22 partial and 57 complete HM, eight choriocarcinoma (CCA) and 28 normal placentas. The M30 immunoreactivity occurred predominantly in the syncytiotrophoblasts. A significantly higher M30 index in HM and CCA was found when compared with normal placentas and spontaneous abortions (P < 0.001). The M30 index of those HM which spontaneously regressed was significantly higher than those HM which developed persistent disease requiring chemotherapy (P < 0.001). The M30 index correlated with another apoptotic index previously detected by TdT-mediated dUTP nick-end labelling (TUNEL) (P = 0.007) and the proliferation index assessed by the Ki67 antigen (P = 0.034).

CONCLUSIONS

We conclude that apoptosis is important in the pathogenesis of GTD. Assessment of apoptotic activity in HM by the M30 index may be considered as an alternative prognostic indicator for predicting the clinical behaviour.

Telomerase activity in gestational trophoblastic disease

AIMS

To investigate the pattern of telomerase activity in hydatidiform mole as compared with normal placenta and choriocarcinoma, and to determine the prognostic significance of telomerase activity in hydatidiform mole.

METHODS

Telomerase activity in 35 cases of hydatidiform mole, 35 normal placentas, one choriocarcinoma sample, and two choriocarcinoma cell lines (JAR, JEG3) was determined using the sensitive polymerase chain reaction based telomeric repeat amplification protocol (TRAP) assay. Two cases of breast carcinoma and two cases of ovarian carcinoma were also included as positive controls in the telomerase assay.

RESULTS

Telomerase activity was detected in 11 of 30 early placentas (36.7%), one of five term placentas (20%), five of 27 hydatidiform moles which regressed spontaneously (18.5%), and six of eight hydatidiform moles which developed persistent trophoblastic disease (75%) (including three which developed metastases). Hydatidiform moles which subsequently developed persistent disease, especially those which metastasised, were more likely to express telomerase activity (p < 0.01). However, there was no significant difference in the frequency of telomerase activity between early placentas and hydatidiform mole. Strong telomerase activity was observed in choriocarcinoma tissue, choriocarcinoma cell lines, and ovarian and breast carcinomas.

CONCLUSIONS

Telomerase activation occurs in hydatidiform mole with a similar incidence to early normal placentas. This supports the concept that hydatidiform mole is essentially an abnormal conceptus. There is an association between telomerase activation and the development of persistent trophoblastic disease. Further study is warrant to confirm the prognostic significance of telomerase activity in hydatidiform mole.

Immunohistochemical and mutational analysis of p53 tumor suppressor gene in gestational trophoblastic disease: correlation with mdm2, proliferation index, and clinicopathologic parameters

The role of p53 in the pathogenesis of gestational trophoblastic disease (GTD) was investigated. Immunohistochemical studies for p53, its regulator mdm2, and proliferation marker Ki67 were performed on paraffin-embedded tissues of 28 partial moles (PM), 57 complete moles (CM), 14 choriocarcinomas (CCA), and 31 normal placentas. Three antibodies to p53 (DO-7, Ab-2, Ab-3) were used and demonstrated immunoreactivity for wild-type p53 protein predominantly in the nuclei of cytotrophoblasts. Direct DNA sequencing of 36 hydatidiform moles using frozen tissues confirmed an absence of mutational changes in exons 5-8. CCA was found to have the highest p53 protein expression, followed by CM, PM, and normal placenta (P < 0.001). In normal placentas (P = 0.0001), PM, and CM (P = 0.016), an inverse correlation between their gestational age and p53 expression was observed. p53 expression was found to correlate with proliferation index in normal placenta (P = 0.0001) and all three groups of GTD (P = 0.012). Significant correlation between p53 and mdm2 expression was also observed (P < 0.01). The distinctive expression of p53 wild-type protein in the cytotrophoblasts and its positive correlation with the proliferative index suggests that its overexpression in GTD may be related to its effect on cell proliferation. The parallel expression of mdm2 and p53 also supports the presence of an autoregulatory feedback loop in the control of this process. No correlation could be found between clinical progress of the patients with hydatidiform moles, and the p53 (P = 0.78) or mdm2 protein (P = 0.54) expression suggesting that neither of them carries any prognostic significance.

PCNA and Ki-67 labelling indices in pre-irradiated and post-irradiated astrocytomas: a comparative immunohistochemical analysis for evaluation of proliferative activity

AIM

To determine the tumour proliferative activity in a series of archival cerebral astrocytomas and compare proliferating cell nuclear antigen (PCNA) and Ki-67 labelling indices in the primary and recurring neoplasms following therapeutic radiation.

METHOD

Twenty eight cases of pre-irradiated and post-irradiated astrocytomas (ranging from WHO grades I to IV) were stained immunohistochemically using the avidin-biotin horseradish peroxidase technique. Two antibodies, PC10 and MIB-1, were used to establish the proliferating labelling indices, PC10 identifies PCNA and MIB-1 recognises the Ki-67 antigen.

RESULTS

Both antibodies showed significantly higher labelling indices in the post-irradiated specimens. However, in general, the Ki-67 indices were lower than those for PCNA. MIB-1 immunoreactivity showed less variation and was more intense than that seen with PC10. The discrepancy between the labelling indices of the pre-irradiated and post-irradiated samples raises questions about the evolution of astrocytomas and the effects of therapeutic intervention.

CONCLUSIONS

The data may represent genetic alterations, the natural tumour course, and/or the effect of radiation. Although both of the antibodies reflected the state of growth of neoplastic cells in astrocytomas, MIB-1 was more reliable. A simple immunohistochemical method using proliferation markers does have an important role in the future care of patients with astrocytoma.

p21WAF1/CIP1 expression in gestational trophoblastic disease: correlation with clinicopathological parameters, and Ki67 and p53 gene expression

BACKGROUND

The p21WAF1/CIP1 gene mediates growth arrest by inhibiting G1 cyclin dependent kinases and has been considered as a downstream effector of the tumour suppressor gene p53.

AIM

To analyse the role of p21WAF1/CIP1 in gestational trophoblastic disease.

METHODS

The immunohistochemical expression of p21WAF1/CIP1 gene was measured in 33 placentas, 28 partial hydatidiform moles, 54 complete hydatidiform moles, and 13 choriocarcinomas in paraffin wax embedded tissue. The results were correlated with p53 (DO7) and Ki67 (MIB1) immunoreactivity as well as clinical progress.

RESULTS

p21WAF1/CIP1 immunoreactivity was found predominantly in the nuclei of the syncytiotrophoblasts. p21WAF1/CIP1 protein expression correlated with gestational age in normal placentas (p = 0.0001) but not in hydatidiform moles (p = 0.89). Complete hydatidiform moles and choriocarcinomas had a significantly higher p21WAF1/CIP1 expression compared with normal placentas and partial hydatidiform moles (p < 0.001); there was no difference between placentas and partial hydatidiform moles. No correlation between p21WAF1/CIP1 expression and either the proliferation (Ki67) index (p = 0.34) or p53 protein accumulation (p = 0.68) was demonstrated. There was no significant difference (p > 0.05) in p21WAF1/CIP1 expression between the 17 patients who developed persistent gestational trophoblastic disease and those who did not.

CONCLUSIONS

This study suggests that p21WAF1/CIP1 expression in trophoblastic disease may be induced by a p53 independent pathway. The proliferative activity of gestational trophoblastic diseases might not be determined solely by the control of the cell cycle operated by p21WAF1/CIP1. p21WAF1/CIP1 expression is not an accurate prognostic indicator of gestational trophoblastic disease.

Comparison of ploidy analysis by flow cytometry and image analysis in hydatidiform mole and non-molar abortion

Determination of DNA ploidy is useful in the diagnosis and classification of hydatidiform mole. Most reports of ploidy analysis in molar tissue have used DNA flow cytometry. Although image analysis cytometry offers theoretical advantages over flow cytometry, there have been few reports of ploidy analysis by image analysis in hydatidiform mole. We selected 47 cases and measured DNA ploidy by flow cytometry and image analysis cytometry in complete hydatidiform mole, partial hydatidiform mole and non-molar abortion. The two cytometry modalities were compared using kappa statistics. There was reasonable overall agreement between the two modalities (kappa = 0.69) and when ploidy was stratified into diploid/polyploid and triploid categories there was near perfect agreement (kappa = 0.93). Aneuploid cell populations, which were not evident on flow cytometry, were identified by image analysis in a significant proportion of complete and partial hydatidiform moles and in a small number of non-molar abortions. Flow cytometry and image analysis cytometry yield comparable ploidy information, useful in the diagnosis and classification of hydatidiform mole. Image analysis cytometry offers greater sensitivity in the detection of small non-diploid cell populations but the significance of this latter finding is uncertain.

Comparison of villous trophoblast proliferation rate in hydatidiform mole and non-molar abortion by assessment of proliferating cell nuclear antigen expression

This study examines the proliferative activity of trophoblast in hydatidiform mole, non-molar hydropic abortion and non-molar spontaneous abortion. Nine cases of complete mole, 10 cases of partial mole, eight cases of non-molar hydropic abortion and six cases of non-hydropic second trimester abortion were examined by routine histopathology and the rate of cell proliferation was assessed by immunoreactivity for proliferating cell nuclear antigen (PCNA). Hydropic abortion showed a significantly lower PCNA index than complete mole and partial mole. There was no significant difference in PCNA index between partial mole and non-hydropic abortion. The trophoblast of partial hydatidiform mole demonstrates significant cell proliferation but this, although higher than that of hydropic abortion, is no higher than that of non-hydropic abortion of a similar gestational age. The role of partial mole as a precursor of persistent gestational trophoblastis disease remains unclear.

Assessment of cell proliferation in hydatidiform mole using monoclonal antibody MIB1 to Ki-67 antigen

AIMS

To assess the role of Ki67 immunoreactivity in predicting the clinical progress of hydatidiform mole.

METHODS

Tissue from 87 hydatidiform moles, 11 normal first trimester placentas, 11 normal term placentas and 17 spontaneous abortions were examined for expression of Ki67 antigen, using the monoclonal antibody MIB1.

RESULTS

Ki67 immunoreactivity was significantly higher in the tissue from normal first trimester placentas than in that from normal term placentas and spontaneous abortions. Among the 87 patients with hydatidiform moles studied, 20 developed persistent gestational trophoblastic disease and required subsequent treatment. There was no statistically significant difference in the Ki67 index between the 20 patients who developed persistent disease and those who did not.

CONCLUSION

Hydatidiform moles which give rise to persistent trophoblastic disease do not have a higher proliferative rate than those which do not. The Ki67 index is not useful for predicting the prognosis of molar pregnancies.