Expression of p120, Ki-67 and PCNA as proliferation biomarkers in imprint smears of prostate carcinoma and their prognostic value

The cell proliferation markers p120, Ki-67 and proliferating cell nuclear antigen (PCNA) recognize nuclear antigens. The expression of these proteins by immunostaining methods was reported to be of value in determining the prognosis of patients with malignant diseases. In this study, we evaluated the prognostic significance of the expression of nuclear antigens p120, PCNA and Ki-67 in prostate cancer and compared the results with other prognostic factors. Imprint smear samples obtained from 70 patients immediately after radical prostatectomy for prostatic carcinoma were immunostained with monoclonal antibodies against p120, Ki-67 and PCNA. The immunostaining results were correlated with Gleason score, tumour differentiation, stage and prostatic specific antigen (PSA) levels. Our findings demonstrate that p120, Ki-67 and PCNA expression in prostatic carcinoma smears, correlated significantly with the degree of Gleason score (P < 0.001). When combining p120, Ki-67 and PCNA positivity with tumour differentiation there was a significant association among these parameters (P < 0.001). Overexpression of p120, Ki-67 and PCNA, was also associated with increased PSA serum levels (>4 ng/ml) (P < 0.001). The distribution of p120, Ki-67 and PCNA expression in prostate carcinomas was not statistically significant for Ki-67 (P = 0.69) and p120 (P = 0.22) but was significant for PCNA (P < 0.001) as far as the histological stage (T2a, T2b, T2c, T3a). P120, Ki-67 and PCNA expression had significant prognostic value for disease-free survival. Our results conclude that nuclear antigens p120, Ki-67 and PCNA appear to be additional markers in the field of prognosis of prostatic carcinoma.     

Measurement of cell proliferation in gastric carcinoma: comparative analysis of Ki-67 and proliferative cell nuclear antigen (PCNA)

Summary Immunostaining to identify nuclear antigens expressed throughout the cell cycle provides a convenient way of assessing proliferating kinetics in tumours. We studied proliferation activity of gastric carcinomas by Ki-67 and PCNA immunostaining and the two methods were compared. The mode of tissue preparation differed, fresh frozen for Ki-67 and formalin-fixed paraffin-embedded for PCNA. Immunostaining with avidin-biotin was used in both. The labelling index (LI) and a semi-quantitative grading of cell proliferation were assessed in both markers. Significant correlation was shown between LI and grading with either Ki-67 and PCNA. However, no correlation was found between PCNA and Ki-67. This lack of relationship between the two markers may be attributed to a number of factors. 1. The most likely is the marked inter- and intra-tumour heterogeneity of gastric carcinomas reflected in high standard deviation values. 2. Preparation of tissue and small size sampling with Ki-67. 3. Long life of PCNA leading to detection of cells that have recently left the cell cycle. 4. One may be observing deregulated expression of DNA as seen in certain tumours. PCNA offers the advantage of being applicable to archival material.     

Cell proliferation in prostatic carcinoma: comparative analysis of Ki-67, MIB-1 and PCNA

Summary Antibodies to assess the proliferative index of tumours are being increasingly employed together with established markers for prognostic evaluation. This study set out to compare three cell proliferation markers, Ki-67, MIB-1 and PCNA, utilizing a semiquantitative method of assessment, in 20 human prostatic carcinomas. The streptavidin-biotin immunostaining system was used for the monoclonal antibodies MIB-1 and PCNA and an indirect immunoperoxidase assay for the monoclonal antibody Ki-67. Significant correlations were found between the expression of Ki-67 in frozen tissues and MIB-1 in formal saline-fixed wax-embedded tissues (p = 0.0003); between Ki-67 and PCNA expression in Bouin's-fixed tissues (p </ 0.0001); and MIB-1 (formalin-saline-fixed tissues) and PCNA (Bouin's-fixed tissues) (p </ 0.0001). A more intense nuclear staining pattern with less heterogeneity was observed for MIB-1 compared with PCNA, suggesting the antibody of choice, on formal saline-fixed tissues, is MIB-1, which closely correlated with Ki-67, a marker we have previously shown to be of prognostic value in prostatic carcinoma.     

Image analysis of in situ cell cycle related changes of PCNA and Ki-67 proliferating antigen expression

Abstract. This study reports on the proliferating cell nuclear antigen (PCNA) and Ki-67 cell cycle related expression and distribution pattern analysed in the same cells. MCF-7 cells were synchronized by mitotic detachment and triple stained for DNA, PCNA and Ki-67. The major cell type was identified on each time sample as a function of the PCNA/Ki-67 pattern, and both antigens as well as DNA were quantified. During G₁ phase, the expression of PCNA greatly increased whereas Ki-67 content decreased. During S phase, nuclear Ki-67 content continuously increased especially in the second half of this phase, mainly due to the accumulation of the antigen in the nucleoli. During G₂ phase, the antigen significantly passed into the nucleoplasm, its content continued to increase and reached its maximum in mitotic cells. Nuclear PCNA content mostly increased in the first part of S phase and sharply declined in mitotic cells as the antigen shifted to the cytoplasm. Cells showing PCNA positive Ki-67 negative labelling were observed in all time samples from the beginning of the experiment. Their nuclear size, DNA content (of G₁ cells), PCNA content (equivalent to the content of some late G, cells) and time occurrence (their percentage increased after the last late G₁ cells had disappeared) tend to indicate that these cells have left the cycle by the end of G₁ phase to enter a quiescent state. Cells coming out of mitosis split into two groups according to their Ki-67/PCNA content. The biggest fraction was PCNA negative and Ki-67 positive while the smallest showed positive staining for both antibodies. Cells of this second cohort slowly lost their 1–67 while their PCNA content increased as they moved through G₁. Concurrently, most of the cells of the first cohort (here called Q2 and Q3 cell types) lost their Ki-67 without increasing their PCNA content; then they joined cells of the second cohort by increasing their PCNA content at the end of G, phase. Some cells of this first cohort can also increase their PCNA and thus reach cells of the first cohort before the end of G₁ phase. The existence of these two main cell cohorts suggests that cells after mitosis differ in some way that make them progress dlfferently through G₁. Some cells seem to go through early G₁ (G_1a and late G₁ (G_lb) while others may come out of mitosis committed to go through the following cycle by directly entering late G₁ compartment.     

PCNA、Ki67 在胰腺疾病中的研究进展

PCNA、Ki-67是与细胞增殖有关的核抗原,在增殖的组织细胞中呈阳性表达,反映组织细胞的增殖活性,是细胞增殖的重要标记物。PCNA、Ki-67在正常发育的胚胎组织、糖尿病、胰腺肿瘤、胰岛移植等胰腺疾病及其他疾病中均高表达,同时也与其他系统肿瘤和疾病密切相关。PCNA、Ki-67作为增殖指标可以用于评价胰腺疾病、胰岛细胞移植后细胞再生数量及其他疾病的诊断、治疗及判断预后。目前已将它们视为细胞的标志物,用于细胞增殖的动力学研究,在临床病理上具有很大的应用前景。未来PCNA、Ki67将广泛应用于临床及基础研究,尤其用于研究胰腺疾病的新靶点、探索糖尿病的发病机制,对疾病的预防和治疗及胰岛移植具有一定的应用前景及意义。     

人乳头状瘤病毒感染与宫颈癌患者临床病理特征和Ki-67、PCNA的关系

目的:研究人乳头状瘤病毒(HPV)感染与宫颈癌患者临床病理特征和Ki-67、细胞增殖抗原(PCNA)的相关性,从而为临床宫颈癌的诊治提供参考依据。方法:选取2016年3月～2018年6月于我院接受手术治疗的宫颈病变患者130例为研究对象。其中宫颈癌患者30例记为宫颈癌组,宫颈上皮内瘤变患者68例记为宫颈上皮内瘤变组,慢性宫颈炎患者32例记为对照组。采用免疫组织化学法检测各组宫颈组织中HPV感染、Ki-67以及PCNA阳性表达情况,并分析HPV与宫颈癌患者临床病理特征的关系及其与Ki-67、PCNA的相关性。结果:宫颈癌组、宫颈上皮内瘤变组患者HPV、Ki-67以及PCNA阳性率均高于对照组,宫颈癌组高于宫颈上皮内瘤变组(均P0.05)。临床分期Ⅲ～Ⅳ期以及淋巴结转移宫颈癌患者HPV感染率均明显高于临床分期Ⅰ～Ⅱ期与无淋巴结转移患者(均P0.05)。经Spearman相关性分析可得:宫颈癌患者HPV感染与Ki-67、PCNA表达均呈正相关关系(均P0.05)。结论:宫颈癌患者存在明显的HPV感染,且HPV感染与宫颈癌患者临床分期、淋巴结转移、Ki-67、PCNA表达存在一定相关性,临床可通过对HPV、Ki-67、PCNA进行联合检测,从而有助于宫颈癌的早期诊断。     

PCNA independence of Ki-67 expression in HPV infection.

12 Infectious Wart lesions were stained using the streptavidin-biotin immunoperoxidase method for PCNA10, MIB-1 (Ki-67 equivalent antigen) and Human Papilloma Virus antigen to study the effect of HPV presence on epidermal proliferation. Using strict methods to avoid observer bias, Ki-67 antigen was found in a high proportion of nuclei in the suprabasal layers together with HPV antigens, in the absence of PCNA staining. This finding indicates that DNA synthesis related, Ki-67 antigen bearing structures can be raised in the human nucleus in the absence of induction of PCNA bearing structures, suggesting also structural independence between the antigen bearing molecules.     

PCNA Ki-67 dissociation in childhood acute lymphoblastic leukaemia. An Immunofluorescent Laser Confocal Scanning Microscopical study.

Cell proliferation rates of diagnostic marrow aspirate cells of 21 children with Acute Lymphoblastic Leukaemia and 16 controls were compared using immunocytochemical labelling of PCNA and Ki-67 antigen as assessed by Confocal Laser Scanning Microscopy. The results showed an unexpected, highly significant degree of dissociation between PCNA and Ki-67 expression in ALL blasts. The PCNA labelling indices of ALL patients were significantly increased (mean 44, range 24-77) compared with normal reactive marrow cells (mean 13.8, range 4-26) (p<0.000001, Mann Whitney U two tailed test), suggesting an abnormal commitment to proliferation. Ki-67 expression was raised to a lesser extent in ALL cells (mean 14.8, range 1.2-35) when compared to non-malignant proliferations (mean 6.6, range 1.7-25) (p < 0.02). PCNA/Ki-67 LI ratios in ALL (mean 7, range 1.1-35) were higher than in controls (mean 2.7, range 1.04-6.5, p<0.09). As cell proliferation rates actually achieved in the bone marrow do not differ as strongly as suggested by the extreme difference in PCNA labelling, a pathological dissociation of PCNA / Ki-67 expression exists, suggesting immortalisation.     

Immunohistochemical evaluation of bcl-2, ER-alpha,caspase -3, -8, -9, PCNA and Ki-67 expressions in canine mammary carcinomas

We investigated the expression of bcl-2, estrogen receptor alpha (ER-alpha), caspase-3, ?8, ?9, proliferating cell nuclear antigen (PCNA) and Ki-67 in canine mammary carcinomas. We used 65 paraffin embedded and re-diagnosed archival canine mammary tumor samples to which we applied the routine streptavidin-biotin-peroxidase technique. Seventeen cases were re-diagnosed as tubulopapillary carcinoma, 31 were re-diagnosed as complex carcinoma and 17 were re-diagnosed as carcinosarcoma. Differences of expression of bcl-2 and PCNA were statistically significant according to tumor type. Differences in expression of ER-alpha, caspase-3, ?8, ?9 and Ki-67 were not statistically significant. Differences of expression of bcl-2 and PCNA were statistically significant compared to ER-alpha, caspase-3, ?8, ?9 and Ki-67 in carcinosarcomas. We report the prognostic significance of bcl-2 and PCNA expression in canine mammary carcinosarcomas.     

Splenic haematopoiesis in primary (idiopathic) osteomyelofibrosis: immunohistochemical and morphometric evaluation of proliferative activity of erythro- and endoreduplicative capacity of megakaryopoiesis (PCNA- and Ki-67 staining)

Using monoclonal antibodies against proliferating cell nuclear antigen or PCNA (PC10) and the Ki-67 antigen (MIB1), an immunohistological and morphometric study was performed on routinely processed splenic tissue from ten patients with primary (idiopathic) osteomyelofibrosis (OMF). To determine the proliferation capacity of erythroid precursors and the endoreduplicative activity of megakaryocytes, corresponding antibodies (Ret40f and CD61) were applied in combination with the cell-cycle markers (sequential double-immunostaining). Morphometric analysis revealed no significant differences in PCNA or Ki-67 reactivity in either cell lineages. In comparison with previous studies on normal bone marrow, in splenic tissue showing myeloid metaplasia, the numbers of PCNA-labelled proerythroblasts, erythroblasts and megakaryocytes were conspicuously increased. Considering the ineffective erythropoiesis in OMF, there seemed to be a disproportional enhancement in PCNA and Ki-67 immunostaining of the red cell lineage. Similarly, the small size of megakaryocytes in advanced, OMF-associated myeloid metaplasia was in keeping with an impairment of endoreduplicative activity. In addition to various other contributory factors, anaemia in OMF may be partially caused by secondary folate (haematinic) deficiency. From experimental studies this defect is known to cause an abnormal arrest in the S-phase of the cell-cycle, comparable to that characterising pernicious anaemia. As a sequel of this pathomechanism, an undue overexpression of PCNA and Ki-67 has to be assumed, that is not necessarily associated with DNA synthesis or cell cycling. This work was supported by a grant from the Deutsche Forschungsgemeinschaft (DFG-Th 390/1-3)     

Flow cytometric multiparameter analysis of proliferating cell nuclear antigen/cyclin and Ki-67 antigen: a new view of the cell cycle

Flow cytometric multiparameter analysis of two proliferation-associated nuclear antigens (proliferating cell nuclear antigen (PCNA)/cyclin and Ki-67) was performed on seven human hematopoietic cell lines. PCNA/cyclin, an S phase-related antigen, was detected using an autoantibody and a fluorescein isothiocyanate-labeled anti-human antibody. The Ki-67 antigen, which in cycling cells is expressed with increasing levels during the S phase with a maximum in the M phase, was detected using a monoclonal antibody and a phycoerythrin-conjugated anti-mouse antibody. In some experiments the PCNA/Ki-67 staining was combined with a DNA stain, 7-amino actinomycin D, and simultaneous detection of the three stains was performed by a single laser flow cytometer. Using this technique four distinct cell populations, representing G1, S, G2, and M, respectively, could be demonstrated in cycling cells on the basis of their PCNA/cyclin and Ki-67 levels. The cell cycle phase specificity could be verified using metaphase (vinblastine, colcemide) and G2 phase (mitoxantrone) blocking agents, as well as by stainings with a mitosis-specific antibody (MPM-2). Also, G0 cells could be discriminated from G1 cells in analysis of a mixture of resting peripheral mononuclear blood cells and a proliferating cell line. This technique can be valuable in detailed cell cycle analysis, since all cell cycle phases can be visualized and calculated using a simple double staining procedure.     

50例胃肠道间质瘤的临床病理分析

目的：探讨胃肠道间质瘤（GIST）的组织形态学特征及对该类肿瘤的诊断及预后问题。方法：对发生于2001年4月至2010年4月间的50例GIST进行临床病理及免疫组化分析。结果：50例GIST免疫组化检查结果,肿瘤均不表达CK而表达为Vimentin;CD117阳性表达43例,CD34阳性表达38例;S100均有不同程度表达,SMA阳性表达22例,Desmin阳性表达15例;Ki-67均有表达,其阳性度从＋．＋＋不等。结论：本组肿瘤中所有病例均不同程度表达Ki-67和PCNA,高危险性的阳性表达强、低危险性的阳性表达弱。这说明GIST的预后除与肿瘤的大小、组织形态学的改变及肿瘤的发生部位有关外,还与Ki-67和PCNA在肿瘤中的表达程度有关。     

Comparison of monoclonal antibodies PC 10 and MIB 1 on microwave-processed paraffin sections

Abstract. Antibodies against the proliferation-associated nuclear antigen (PCNA) and against the Ki-67 protein are widely used as operational proliferation markers in human tumour diagnostics. The original Ki-67 antibody had the inherent drawback in that it could only be used when fresh-frozen material was available. The antibody PClO was supposed to offer the advantage that it could be applied on formalin-fixed and paraffin-embedded tissues. However, in cases in which the formalin fixation exceeded 4 h, PC10 staining proved to be inconsistent and often failed.
The aim of this study was to compare a recently prepared Ki-67 equivalent monoclonal antibody (MIB 1) and PC10 in routinely fixed histopathological material using antigen retrieval by microwave processing.
Antibody MIB 1 stained the nuclei of cells known to belong to the proliferative compartments in microwave-processing paraffin sections of formalin-fixed tissues. Quiescent cells were consistently negative for MIB 1 staining. In contrast, PC10 was positive in almost all nuclei of different tissues in microwave-treated paraffin sections. Thus, antigen retrieval by microwave processing is beneficial for the detection of the Ki-67 protein in paraffin sections, whereas it is not needed for the detection of the PCNA.     

Cyclin D1 Immunoreactivity in Meningiomas

Objective Cyclin D1 is an important nuclear protein required for progression of cells through the G1 phase of the cell cycle. The proliferative potential of meningiomas has been studied using various proliferative markers. However, there have been only few published studies evaluating Cyclin D1 immunoreactivity in meningiomas. Purpose of the study The aim of our study was to analyze the Cyclin D1 expression in meningiomas and correlate it both with proliferation markers Ki67 and PCNA, and with meningiomas of WHO grade. Material and methods We evaluated immunoreactivity for proliferative markers (Cyclin D1, Ki-67, and PCNA) in a consecutive series of 64 meningioma samples obtained from patients who underwent surgical resection because of cerebral or spinal meningiomas. Immunohistochemical staining with Ki-67, PCNA, and Cyclin D1 was performed using the microwave processing procedure and LSAB+ methodology. The number of positive cells for each antibody has been determined and shown in percentage in relation to 1000 counted cells. Results All meningioma samples showed immunostaining for Ki-67, PCNA, and Cyclin D1 antibodies. The Cyclin D1 scores exhibited a close correlation with Ki-67 and PCNA immunostaining (P < 0.01). Some meningiomas (15 cases) showed a combination of nuclear and cytoplasmatic (fine granular) Cyclin D1 immunoreactivity. All proliferative indexes have been in positive correlation with meningioma grade. Conclusion Our comparative study of proliferative markers in meningiomas demonstrated Cyclin D1 as a very useful proliferative marker in meningiomas.     

Flow cytometric analysis of proliferation associated nuclear antigens using washless staining of unfixed cells.

The expression of different proliferation associated nuclear antigens was analyzed using a washless double-staining method and flow cytometry. It is a simple and rapid two-step procedure which can be performed on low cell numbers. A series of hematopoietic cell lines and fresh lymphoma cells were tested and the methodology was found to be applicable to a number of nuclear antigens (PCNA, Ki-67, p105, MPM-2, fibrillarin). For PCNA, the detectability was dependent on the type of antibody used. The immunofluorescence pattern observed by microscopy was altered for antigens stained by the washless technique in comparison with the pattern obtained with fixed cells. With the washless method, detailed cell cycle analysis could be obtained by dual parameter analysis of PCNA and Ki-67.     

Cell cycle-related proteins: a flow cytofluorometric study in human tumors

We used 2-parameter flow cytometry (FCM) to investigate the relationship between the cell cycle phases and 3 proteins whose expression is known to increase in proliferating cells: the surface antigen transferrin receptor (Trf-r), the "cyclin" (a proliferating cell nuclear antigen, PCNA), and the nuclear antigen recognized by the monoclonal antibody (MoAb) Ki-67. FITC-labeled antibodies against Trf-r, PCNA, and the Ki-67-reactive antigen, as well as propidium iodide-DNA distribution, were simultaneously measured on human leukemia HL-60 and K562, and breast carcinoma MCF-7 cell lines and on fresh human leukemic and glioblastoma cells. The 70% ethanol fixation for Trf-r and PCNA and the 95% acetone fixation for Ki-67 plus permeabilization (with 0.1% and 1% Triton X100, respectively, for the surface and the nuclear antigens) produced cell suspensions with negligible cell clumping, high-quality DNA profiles, and bright specific immunofluorescent staining. The investigated proteins have different relationships with the proliferative state of the cell. Trf-r is expressed mainly at the transition from G0/G1 to S-phase. PCNA expression is prominent in late G1 and through S-phase and decreases in G2-M. The Ki-67-reactive antigen is widely distributed in G1, S, and G2-M phases. Knowledge regarding the relationships between proliferation-associated antigens and cell cycle phase in normal and neoplastic cells could improve our understanding of the mechanisms underlying growth regulation and neoplastic transformation. Bivariate FCM is an easy method for obtaining these data from large numbers of cells.     

A comparison of different methods to determine cell proliferation by flow cytometry

Abstract. The proliferation of human melanoma cells (MeWo) in vitro was studied with a number of different techniques. In particular, we compared the expression of PCNA and the Ki-67 antigen on the one hand with BrdU pulse and continuous labelling on the other. Two-dimensional flow cytometry (with DNA content as a second parameter) was employed to discriminate between cycling and non-cycling cells as well as cells in the G₁, S and G₂ phases of the cycle. Cell cultures in different stages of growth were analyzed. We found that the percentage of anti-PCNA and Ki-67 positive cells agreed very well with the BrdU pulse and continuous labelling index, respectively. Our data further support the assumption that under certain conditions PCNA is a marker of S-phase cells, whereas Ki-67 can be used to quantify the growth fraction. Possible pitfalls of the techniques are discussed.     

Evaluation of immunohistochemical markers of germ cells' proliferation in the developing rat testis: a comparative study

Germ cells' proliferation during testicular organogenesis in Wistar rat embryos and neonates [14.5, 18.5, 20.5 days post conception (dpc), birth (day 0), 1, 3, 5, 7 days post partum (dpp)] was evaluated via immunohistochemistry, using the PCNA and Ki-67 nuclear antibodies. Estimation of the reactive/total cell ratio, per visual field [labeIing index (LI)] was achieved using the Image Pro Plus Software. Immunostaining of the fetal testis, with both antibodies, revealed increasing germ cells' numbers between 14.5 dpc and birth. From birth onwards, a sharp decline of germ cells' population was observed in the first 3 days of postnatal life. Then, a transient increase of the LI, between 3 and 5 dpp, was noted. Afterwards, proliferation of germ cells ceased. These results indicate that, during fetal and neonatal life, two peaks of proliferative activity of germ cells are noticed. Following estimation of the LI for both PCNA and Ki-67, a prominent labeling for the first antibody was observed throughout the examined period. Ki-67 staining follows a similar pattern, showing, however, significant fluctuation in the obtained values, in comparison to PCNA. The significant differences observed don't seem to be simply a result of the different half lives of the two markers, but rather a consequence of additional underlying cellular activity associated with PCNA, such as DNA repair.     

Follicular cells versus oocytes: cell population dynamics in the developing ovary

The aim of the current paper is to evaluate the correlation of germ and follicular cells kinetics during ovarian morphogenesis. Thus, immunohistochemical detection of PCNA and Ki-67 proteins has been examined using PC10 (Dako) and NCL-Ki-67 (Novocastra) antibodies in the developing ovaries of Wistar rat embryos and neonates [14.5, 18.5, 20.5days post-coitum (dpc), birth (day 0), 1, 3, 5, 7day post-partum (dpp)]. Estimation of reactive/total cell ratio, per cell type (germ and follicular cells) and visual field was achieved using the Image Pro Plus Software. The statistical interpretation of the results has shown that, before birth, using the PCNA antibody, the percentage of labeled/total germ cells (labeling index, LI) increases from 71.19% at 14.5dpc to 75.66% at 18.5dpc. It then decreases to 73.26% at 20.5dpc. At birth, the labeling index drops significantly (28.57%). Immediately after birth, the percentage of labeled/total germ cells increases, reaching 43.58% at 1dpp. Subsequently, a further decrease in the percentage of reactive cells is observed resulting to a maximum drop of the LI at 7dpp (18.41%). Using the Ki-67 antibody, the percentage of labeled/total germ cells is generally lower although the fluctuation is similar with that observed using the first marker of cell proliferation. Using the PCNA antibody, the LI of follicular cells in the developing ovary, increases from 0.70% (at 14.5dpc) to 28.94% (at 18.5dpc) and then drops to 18.03% (at 20.5dpc). At birth, the percentage of reactive follicular cells, reaches 27.66% and remains high thereafter. Similar results are obtained using the Ki-67 antibody. In conclusion, follicular cell reaction ratio, using both antibodies (PCNA and Ki-67), increases continuously throughout the examined period with a maximum value at 7dpp, suggesting a kinetics profile similar to that observed for Sertoli cells in the testis. In all age groups, PCNA labeling is more intense than Ki-67, a result that may be attributed to selective staining at different periods of the cell cycle.     

Assessment of proliferative activity of thyroid Hürthle cell tumors using PCNA, Ki-67 and AgNOR methods

We have undertaken an attempt to compare the application efficacy of the proliferative activity markers in differential diagnosis of thyroid Hürthle cell tumors (HCT) using the PCNA and Ki-67 labeling and AgNOR visualisation techniques. The present work is a retrospective analysis of 78 Hürthle cell tumors: 20 Hürthle cell carcinomas (HCC), 32 Hürthle cell adenomas (HCA) and 26 hyperplastic nodules with Hurthle cell metaplasia (HCM). Five microm sections were stained according to AgNOR technique and labeled with antibodies against PCNA and Ki-67. AgNOR dot count in the nucleus and proliferative index (PI - percentage of cells expressing PCNA and Ki-67) in randomly chosen nuclei (100 in case of AgNOR and over 1000 in case of PI) were evaluated in each slide. The mean values of AgNOR dot count, PI-PCNA and PI-Ki-67 in HCC, HCA and HCM were respectively: 5.1, 61.3 and 54.9; 3.4, 42.4 and 38.6 and 2.5, 39.3 and 34.3. Statistically significant difference was found in all the proliferative activity markers between malignant and benign tumors: HCC:HCA (p<0.01) and HCC:HCM (p<0.001). There was no statistically significant difference between HCA and HCM.