共查询到20条相似文献,搜索用时 15 毫秒
1.
W. Gorczyca M. Markiewski A. Kram T. Tuziak W. Domagala 《Virchows Archiv : an international journal of pathology》1995,426(3):229-233
We examined 59 breast cancers for p53 and bcl-2 protein expression by immunohistochemistry. The results were correlated with Ki-67 immunostaining. p53-negativity was noted in 40 cases and the remaining 19 tumours were p53-positive. Thirty-six tumours showed strong expression of bcl-2 and in 23 no staining for this protein was observed. We found statistically significant reverse correlation between expression of p53 and bcl-2 in majority of carcinomas: 31 cases were bcl-2 positive and p53-negative, and 14 tumours were bcl-2-negative and p53-positive. Six carcinomas showed no nuclear staining for Ki-67 and in the remaining 53 the percent of cancer cells positive for Ki-67 ranged from 1 to 60 (mean: 14.6). In these 53 cases we found that bcl-2-positive tumours were characterized by lower proliferation than bcl-2-negative tumours, the mean value of Ki-67 immunostaining being 10.7% and 23.0%, respectively. p53-negative tumours showed lower proliferation than p53-positive tumours: mean Ki-67 index was 10.2% and 23.9%, respectively.We conclude that immunohistochemically detected p53 and bcl-2 proteins show a significant inverse relationship in majority of breast carcinomas and their expression correlates with tumour proliferation (Ki-67 immunostaining). 相似文献
2.
Correlation of p53 protein expression with apoptotic incidence in colorectal neoplasia 总被引:3,自引:0,他引:3
M. Kobayashi H. Watanabe Y. Ajioka M. Yoshida J. Hitomi H. Asakura 《Virchows Archiv : an international journal of pathology》1995,427(1):27-32
The wild-type p53 gene suppresses cell proliferation and induces apoptosis when it is transfected into human colon cancer cell lines. Therefore, mutation of the p53 gene, which correlates closely with p53 protein overexpression, would be predicted to activate cell proliferation and limit apoptosis. We tested this hypothesis by correlating p53 protein expression with cell proliferation and apoptosis in 70 neoplasms (29 adenomas and 41 carcinomas) using p53 and Ki-67 immunohistochemical staining and DNA nick end labelling. The p53 immunoreactivity was independent of the Ki-67 positivity. The apoptotic incidence was less frequent (P<0.005) in tumours with diffuse p53 protein overexpression than in those with the sporadic overexpression, defined as p53 staining of isolated or scattered expression. In addition, apoptotic incidence only correlated directly (P<0.05) with Ki-67 positivity in tumours with sporadic p53-protein expression. These results indicate that p53 protein that is expressed sporadically in colorectal neoplasms is probably wild-type protein and induces apoptosis in response to active cell proliferation. In contrast, diffusely overexpressed p53 protein in colorectal neoplasms is probably mutant and correlates with a reduction in apoptotic cell death independently of cell proliferation. 相似文献
3.
Carlinfante G Lazzaretti M Ferrari S Bianchi B Crafa P 《Pathology, research and practice》2005,200(11-12):791-799
Adenoid cystic carcinoma (ACC) is an indolent tumor that pursues a protracted clinical course with recurrences and late metastases. The aim of this study was to investigate immunohistochemically the expression of p53, bcl-2 protein, and Ki-67 in 21 cases of ACC of the palate, all with a minimum of 10 years and a maximum of 22 years of clinical follow-up. These results were also analyzed with regard to different clinical prognoses of the histologic subtypes of ACC. High expression of p53 and bcl-2 was noted in 19 out of 21 ACC cases (90%), in which most tumor cells (from 66% to 99%) proved to be immunopositive. A relation to the histologic types, clinical staging, and survival was not found. Therefore, the high immunoreactivity against these oncoproteins in the same tumor cells suggests that these two oncogenes may be involved since the early stage of carcinogenesis. Loss of function of the p53 protein combined with bcl-2 upregulation might give the tumor cells a double growth advantage, because uncontrolled proliferation is combined with a reduced cell death rate. The interaction with other oncogenes may then trigger a multistep process able to promote tumor progression. The low labeling index Ki-67 was detected in nine out of 21 cases (42%), with a low percentage of tumor cells (from 3% to 15%) being positive, whereas the remaining 12 cases were negative. We found no relation to the histologic types, clinical staging, and survival; however, the low proliferation rate could explain the natural course of tumor. 相似文献
4.
Mitsunobu Masuda Yasuo Takano Masayuki Iki Tomoyuki Asakura Takafumi Hashiba Sumio Noguchi Masahiko Hosaka 《Pathology international》1998,48(1):41-46
The prognostic significance of Ki-67, p53, and Bcl-2 expression was evaluated in prostate cancer patients with lymph node metastases. Immunohistochemical staining of archived material obtained from 56 patients was performed by the streptavldin-biotin method. Univariate survival analysis showed that a Ki-67 labeling index (Ki-67 LI) of ≥8.4 in the primary tumor identified a group of patients with a significantly poorer prognosis (P<0.001). Furthermore, a Ki-67 LI of ≥8.7 in the nodal metastatlc tumor was also associated with a poorer prognosis (P<0.01). Multivariate analysis showed that the Ki-67 LI of primary tumors (P<0.01) and lymph node metastases (P<0.01) had independent prognostic value. p53 and Bcl-2 expression had no prognostic value in patients with prostate cancer and lymph node involvement. The Ki-67 LI has more prognostic value than p53 and Bcl-2 expression for patients with prostate cancer that has spread to the lymph nodes. 相似文献
5.
肺癌中P63与P53、E-cadherin、Ki-67表达的比较 总被引:1,自引:2,他引:1
目的 比较 p6 3及 p5 3、E cadherin(E cad)、Ki 6 7在肺癌中的表达 ,以了解在不同组织类型肺癌发生发展过程中 ,p6 3与抑癌基因 (p5 3)突变、上皮分化标志基因 (E cad)失活及细胞增殖标志基因 (Ki 6 7)激活有无相关性。方法 采用免疫组化S P法分别检测 6 1例原发性肺癌中 p6 3、p5 3、E cad和Ki 6 7的表达情况。 结果 p6 3在肺鳞癌中阳性率为 10 0 0 % ,而在其他组织类型肺癌中 p6 3基本不表达 ,差异有显著性 (P <0 0 5 ) ;在不同分化程度的肺鳞癌中 p6 3、p5 3的表达差异有显著性 (P<0 0 5 ) ,E cad、Ki 6 7的表达差异无显著性 (P >0 0 5 ) ;E cad的表达在小细胞肺癌与肺鳞癌和肺腺癌之间差异有显著性 (P <0 0 5 ) ;Ki 6 7的表达在各种组织类型肺癌之间差异有显著性 (P <0 0 5 ) ;在不同分化程度鳞癌中 p6 3与E cad的表达呈负相关(P <0 0 5 )。结论 p6 3可作为鳞状上皮源性肿瘤标记物 ,是判断鳞状细胞癌的增殖和分化有意义的指标 ,并可作为鉴别分化差的鳞癌和腺癌、小细胞癌的指标。 相似文献
6.
7.
Wenbin Li Lei Guo Xingang Bi Jianhui Ma Shan Zheng 《International journal of clinical and experimental pathology》2015,8(8):9446-9451
Backgound: Renal epithelioid angiomyolipoma (EAML) is a rare variant of AML (angiomyolipoma) and is often associated with aggressive behaviors. The pathogenesis of EAML has been poorly understood. We analyzed the expression of p53 and Ki-67 by immunohistochemistry (IHC) and investigated p53 mutation analysis in 11 cases of EAML in comparison to classical AML. Methods: P53 and Ki-67 expression status were determined by IHC staining. P53 mutation analysis was performed using bi-directional sequencing. Results: Renal EAML tumors were significantly associated with more severe to moderate nuclear atypia (100% vs. 36.4%, P = 0.004) and mitotic activity (90.9% vs. 27.3%, P = 0.008) compared with AML tumors. Out of 11 cases of EAML, 8 were positive for p53. There was only 1 case with positive p53 expression in AML cases and expression of p53 protein showed significant difference between EAML and AML tumors (72.7% vs. 9.1%, P = 0.008). In addition, there were 7 AML and 6 EAML cases harbored P72R mutation (SNP) in exon 4 of p53. Compared with AML cases, 2 out of 11 cases of EMAL showed more than 10% positivity for ki-67. The finding of stronger p53 expression in renal EAML might have contributed to their malignant behavior. However, the abnormal p53 expression cannot be entirely explained by p53 mutations in the exons examined. Conclusions: Thus, the combination of immunohistochemical assessment of tumor antigens might improve our ability to predict the malignant outcome in EAML. 相似文献
8.
The significance of immunohistochemical expression of Ki-67, p53, p21, and p16 in meningiomas tissue arrays 总被引:1,自引:0,他引:1
Although histologic grading of meningiomas has prognostic and clinical implications, it is difficult in some cases to predict the outcome of patients. There have been several efforts to evaluate the use of different immunohistochemical markers for predicting meningioma prognosis. We analyzed the immunohistochemical expression of Ki-67, p53, p21, p16, and PTEN proteins in 130 meningiomas (64 benign, 39 atypical, and 27 malignant meningiomas) using tissue microarray. The tumors were graded according to the World Health Organization classification. There was a statistically significant correlation between the expression of Ki-67, p53, p21, p16, and the grade of meningiomas (p0.001). By ordinal logistic regression, p53 and Ki-67 were significantly associated with grade, and an increase of 1% in the labeling index of these markers resulted in an increase in the risk of raising the grade by 2.17 and 1.49, respectively. Histological grade, p53, Ki-67 labeling indices, and overexpression of p16 were strongly associated with decreased event-free survival in univariate analysis. In contrast, multivariate analysis revealed that only tumor grade is an independent factor for predicting meningioma recurrence. We conclude that the Ki-67 and p53 labeling indices are useful additional tools in discriminating atypical from benign or anaplastic meningiomas, especially in histological borderline cases. 相似文献
9.
Expression of cyclin D1, Ki-67 and PCNA in non-small cell lung cancer: prognostic significance and comparison with p53 and bcl-2 总被引:7,自引:0,他引:7
Uncontrolled cell proliferation is the hallmark of malignant tumours. Thus, the proliferative potential of tumour cells is an important prognostic factor. However, evaluation of the prognostic significance of the expression of proteins involved in regulation of cell proliferation remains controversial. In the present study, expression of Ki-67, PCNA and cyclin D1 was estimated in a group of 89 surgically resected non-small cell lung carcinomas using immunohistochemistry. The results were compared with expression of bcl-2 and p53 and with clinicopathological parameters including patients' survival. Ki-67 and PCNA were found to be moderately and highly expressed in 39% and 44% of the tumours, respectively. There was a strong correlation between Ki67 and PCNA expression. Forty five of 88 tumours (51%) showed overexpression of cyclin D1. Surprisingly, cyclin D1 was mainly localized in the cytoplasm and only a small group of tumours (9/88, 10%) showed nuclear staining as well. Bcl-2 and p53 expression was observed in 69% and 30% of the tumours, respectively. All these markers were found to be independent of clinicopathological parameters, except for Ki-67 and bcl-2 expression, which was associated with squamous cell carcinomas. It is concluded that none of the markers that were studied can be used as an independent prognostic factor, whereas the following combinations of markers may have favourable prognostic value: p53 positivity and low Ki-67 expression, p53 positivity and lack of cyclin D1 expression, bcl-2 positivity and low Ki-67 expression, and lack of cyclin D1 expression and low Ki-67 expression. 相似文献
10.
目的 研究新疆维吾尔族 (维族 )和汉族、浙江汉族结直肠癌组织中 p5 3、Ki 6 7、COX 2蛋白的表达 ,探讨其表达上的差异。方法 应用免疫组化S P法对 14 4例结直肠癌组织 (新疆维族 38例和汉族 5 2例、浙江汉族 5 4例 )中p5 3、Ki 6 7、COX 2蛋白表达进行检测。结果 3组结直肠癌患者性别构成差异无统计学意义。维族结直肠癌发病年龄早于两组汉族 (浙江汉族、新疆汉族和维族病人的年龄分布分别为 5 7 7± 12 6、5 7 0± 11 5、5 1 4± 11 2岁 ,经方差分析 ,F =3 5 2 0 ,P <0 0 5 )。组织学类型 :浙江汉族病人管状腺癌占 82 7% ,新疆汉族和维族病人乳头状腺癌所占的比例高于浙江汉族 ,3组间差异有显著性(P <0 0 5 )。结直肠癌间分化程度 :新疆汉族高于其他两组 (P <0 0 1)。调整年龄、性别因素后经多因素Logistic回归模型分析 ,民族与结直肠癌p5 3蛋白的阳性表达有关。维族 p5 3阳性率高于汉族 ,比值比为 2 4 92 (95 %CI 1 0 4 6~ 5 939)。新疆汉族和维族结直肠癌与Ki 6 7和COX 2蛋白表达无相关性。结论 维族结直肠癌 p5 3蛋白表达高于汉族病人 ,其意义值得进一步探讨。 相似文献
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12.
bcl-2和p53表达在结直肠癌预后评估中的价值 总被引:2,自引:0,他引:2
目的 探讨bcl 2和 p5 3表达水平与结直肠癌肿瘤生物学特征及其预后的关系。 方法 应用免疫组化S P法 ,检测93例结直肠癌标本中bcl 2与p5 3蛋白的表达 ,并与临床病理特征进行相关分析。结果 bcl 2蛋白在结直肠癌的阳性表达率为 5 7 0 % (5 3/ 93) ,与淋巴结转移呈负相关 (P <0 0 1) ,p5 3表达阳性率为 4 3% (4 0 / 93) ,与淋巴结转移无相关 (P >0 0 5 ) ,但p5 3表达阳性患者的预后差于 p5 3阴性组 (P =0 0 1)。当分析bcl 2和 p5 3联合表达时 ,Dukes分期及淋巴结转移各组间有差异 (P <0 0 5 )。其中bcl 2 (+) / p5 3(- )表达形式多见于DukesA和B期肿瘤 (4 1 0 % ,2 3/ 5 6 )。经Cox模型多因素分析结果表明 ,淋巴结转移 (P <0 0 1)和 p5 3表达 (P <0 0 1)是结直肠癌独立预后影响因素。其他指标 ,包括bcl 2和 p5 3联合表达情况等均未显示出统计学意义。结论 bcl 2和p5 3表达水平可提示结直肠癌的生物学行为 ,但bcl 2的表达与淋巴结转移状况相关不是一个单独作用的预后指标 ,而 p5 3虽与其它生物学特性关系不大 ,却是一个相对独立的结直肠癌预后指标。 相似文献
13.
Feng YZ Shiozawa T Horiuchi A Shih HC Miyamoto T Kashima H Suzuki A Nikaido T Konishi I 《Virchows Archiv : an international journal of pathology》2005,447(5):816-822
To further elucidate the significance of p53 mutation in endometrial carcinoma, we investigated it in endometrioid-type endometrial
carcinomas showing intratumoral heterogeneous p53 expression. In addition, we also examined the correlation of p53 mutation
and cyclin A expression, because we previously reported a topological correlation between the expression of p53 and cyclin
A. The p53 mutation in exons 5–8 in 54 cases of endometrial carcinoma showing immunohistochemical expression of p53 was examined
using microdissected tissue DNAs. Of the 54 p53-positive endometrial carcinomas, 23 (43%) had p53 mutation with a tendency
in histologically higher grade tumors. Ten of the 54 showed a heterogeneous p53 expression, and in 9 of the 10 cases, p53
mutation was present only in p53-positive sites, which were often found in histologically less differentiated areas with elevated
Ki-67 in the same tumor. Cyclin A expression was topologically observed in p53-positive areas; however, it was noted in both
tumors with (12/23, 52%) and without (18/31, 58%) p53 mutation. These results suggest that p53 mutation is a late event and
plays an important role in the acquisition of malignant potentials in endometrioid-type endometrial adenocarcinomas. Unexpectedly,
accumulation of the p53 protein itself may be important in cyclin A overexpression. 相似文献
14.
Recent studies have shown bcl-2 to be regulated by p53. Other studies have suggested an inverse relationship between p53 and bcl-2 protein expression in breast and colonic cancers and in a variety of subtypes of non-Hodgkin's lymphoma. This study investigates the relationship between bcl-2 and p53 protein expression and the correlation between these findings and the grade and cell type of follicular lymphomas according to the REAL classification. Paraffin-embedded nodal follicular lymphomas (n=37) were subjected to bcl-2 and p53 immunohistochemistry on tissue sections using a three-step ABC system. Positive immunostaining for both oncoproteins was scored using a three-tiered scale: +, <10 per cent cells; ++, 10–50 per cent cells; and +++, >50 per cent cells (<10 per cent was used as a cut-off to define negative tumours). Ninety-seven per cent (36/37) of follicular lymphomas expressed bcl-2 protein in all three grades, manifesting in the small cell (grade 1) through to the large cell (grade 3). p53 protein expression showed a pattern of increasing immunostaining with progression towards the high-grade follicular lymphoma: grade 1=6 per cent (1/16); grade 2=48 per cent (10/21); grade 3=100 per cent (6/6). Five cases comprised varying combinations of grades. This latter finding suggests a role for p53 mutation in the progression/transformation of follicular lymphoma. The mechanism, however, differs from that suggested in breast and colonic cancers, since an inverse relationship between bcl-2 and p53 was not demonstrated in the present study. © 1997 John Wiley & Sons, Ltd. 相似文献
15.
Valeria Barresi MD Francesca Romana Buttarelli BBs Enrica Vitarelli E Bbs Antonella Arcella Bbs Manila Antonelli MD Felice Giangaspero MD 《Human pathology》2009,40(12):1738-1746
Caveolin-1 (cav-1) has been proposed as an immunohistochemical marker able to distinguish astroglial from oligodendroglial tumors. In addition, it has been suggested that the reduction of caveolin-1 expression in glioblastoma cells increases their proliferative and invasive potential. Accordingly, the present study investigates caveolin-1 immunoexpression and correlation with the 1p/19q status, histologic grade, proliferation index, epidermal growth factor receptor, and p53 expression in a series of 73 diffuse gliomas. A membranous and cytoplasmic immunolabeling for caveolin-1 was detected in neoplastic cells of 60% of cases. No significant differences in terms of caveolin-1 expression were observed between astrocytomas, oligodendrogliomas, and oligoastrocytomas. In addition, caveolin-1 expression was not correlated with 1p/19q status in oligodendrogliomas and mixed oligoastrocytomas. Caveolin-1 was expressed in most high-grade (World Health Organization III and IV) gliomas. Low caveolin-1 expression correlated with a higher Ki-67 labeling index and the absence of p53 overexpression in glioblastomas, and it was significantly associated with epidermal growth factor receptor overexpression in anaplastic astrocytomas. In conclusion, the present study indicates that caveolin-1 is not useful as diagnostic marker to differentiate grade II astrocytomas from oligodendrogliomas. 相似文献
16.
胃复康对人SGC-7901胃癌细胞株p53、bcl-2基因表达的影响 总被引:1,自引:0,他引:1
目的探讨中药胃复康对人SGC-7901胃癌细胞株p53、bcl-2基因表达的影响。方法PRMI1640血清培养的人SGC-7901胃癌细胞株分为胃复康实验组、生理盐水对照组和顺铂(DDP)化疗组。利用血清药理学方法制备药物血清,作用48h后,应用免疫细胞化学方法和图像分析方法观察胃复康、DDP对人SGC-7901胃癌细胞株p53、bcl-2基因表达影响。结果免疫细胞化学法显示抑癌基因p53和癌基因bcl-2主要定位在细胞质内。胃复康、DDP药物血清作用后,p53表达明显增强,bcl-2表达明显降低;随着作用时间延长,两种基因表达改变更明显。胃复康、DDP药物血清组p53和bcl-2表达的光密度值(AOD)与对照组差异显著(P<0.01)。结论中药胃复康药物血清上调p53和下调bcl-2的表达可能是其抑制胃癌细胞株SGC-7901的作用机制之一。 相似文献
17.
A case of adenocarcinoma of the rectum in a 41-year-old woman, in association with Crohn's disease is presented. The patient had suffered diarrhea and constipation, and Crohn's disease was suspected. Although the endoscopy did not reveal the presence of any tumors, biopsy specimens demonstrated adenocarcinoma. A Miles' operation was performed. The adenocarcinoma was composed of various grades of atypia and had invaded the non-peritonealized perirectal tissues. The infiltration of lymphocytes and plasma cells was moderate at the perimeter of the carcinoma and mild in the distant regions. Epithelioid cell granulomas were found. The p53 labeling index (LI) increased with the grade of atypia over the entire length of the carcinomatous gland. In carcinomas with high grade atypia, the p53 LI was high in both the upper and the lower halves of the gland. In carcinomas with low or moderate grade atypia however, the p53 LI was high in the lower half and low in the upper half of the gland. The Ki-67 LI over the entire gland was higher in carcinomas with high grade atypia than in carcinomas with low or moderate grade atypia. 相似文献
18.
Kenichi Ohashi Tetsuo Nemoto Yoshinobu Eishi Atsumi Matsuno Kyoichi Nakamura Katsuiku Hirokawa 《Virchows Archiv : an international journal of pathology》1997,430(2):107-115
Using oesophageal squamous cell carcinoma samples of both intramucosal and advanced types, proliferative activity (Ki-67 labelling index), p53 protein accumulation and apoptosis (in situ DNA nick end labelling) were assessed, and the relation of these values to progression or differentiation grade of tumours was analysed. In terms of proliferative activity and the proportion of positive cases with p53 accumulation, a statistically significant difference was demonstrated between intraepithelial carcinomas and intramucosal carcinomas with stromal invasion (17.2% vs 31.7% for the Ki-67 labelling index, and 23.5% vs 67.4% for the proportion of positive cases of p53 accumulation). Values for the latter were almost comparable to those of advanced carcinomas. Immunohistologically, Ki-67 positive, proliferating cells were distributed preferentially in the peripheral fronts of invading nests. Apoptotic cells were observed in the inner areas of the invading nests of the intramucosal carcinomas with stromal invasion and in more advanced lesions, but were rarely observed in the normal epithelium or intraepithelial carcinomas. Apoptotic cells were seen mainly around areas of keratinization, and the apoptotic cell index was higher in well and moderately differentiated types of advanced carcinomas than in the poorly differentiated type (2.59% vs 1.09%). An increase in proliferative activity and an accumulation of p53 protein are associated with the onset of early carcinomatous invasion, while apoptosis is closely linked with the differentiation grade of carcinoma cells. 相似文献
19.
Kyubo Kim Eui Kyu Chie Wonshik Han Dong-Young Noh In Ae Park Do-Youn Oh Seock-Ah Im Tae-You Kim Yung-Jue Bang Sung W. Ha 《Journal of Korean medical science》2010,25(2):235-239
Prognostic value of p53 and bcl-2 expression on treatment outcome in breast cancer patients has been extensively evaluated, but the results were inconclusive. We evaluated the prognostic significance of these molecular markers in patients treated with breast conserving surgery and radiotherapy. One hundred patients whose immunostaining of p53 and bcl-2 expression was available among 125 patients who underwent radiotherapy after breast conserving surgery and axillary lymph node dissection were enrolled into this study. Eighty-seven patients also received adjuvant chemotherapy and/or hormonal therapy. Conventional clinicopathologic variables and treatment-related factors were also considered. The 5-yr loco-regional relapse-free and distant metastasis-free survival rates were 91.7% and 90.9%, respectively. On univariate analysis, age, T stage and the absence of bcl-2 & estrogen receptor (ER) expression were associated with loco-regional relapse-free survival. When incorporating these variables into Cox proportional hazard model, only bcl-2(-)/ER(-) phenotype was an adverse prognostic factor (P=0.018). As for the distant metastasis-free survival, age, T stage, and p53 expression were significant on univariate analysis. However, p53 expression was the only prognosticator on multivariate analysis (P=0.009). A bcl-2(-)/ER(-) phenotype and p53 expression are useful molecular markers predicting loco-regional relapse-free and distant metastasis-free survival, respectively, in patients treated with breast conserving surgery and radiotherapy. 相似文献
20.
Oral squamous cell carcinoma develops through a series of precancerous stages manifested at the microscopic level as epithelial dysplasia. Mutation of the p53 tumour suppressor gene is thought to be an important component of oral carcinogenesis. p53 regulates cell proliferation and DNA repair by inhibiting the cell cycle at G1/S; loss of p53 function may therefore lead to aberrant cell kinetics. To date, no studies have examined the relationship between p53 protein and alterations in cell kinetics in oral epithelial dysplasia from a single anatomical site. Serial sections were studied from 40 routinely processed biopsy specimens of epithelial dysplasia from the floor of the mouth. The expression of p53 protein was determined by immunohistochemistry and cell proliferation was studied by immunostaining for the cell cycle-dependent protein Ki-67. The number of positive cells per millimetre of basement membrane was determined using computer image analysis and compared with site-matched normal controls. The mean p53 labelling index (LI) in normal mucosa was low, 3·48±0·92 [mean±95 per cent confidence interval (CI)], and increased sharply in the transition from mild (42·49±21·71) to moderate (104·86±51·39) epithelial dysplasia. The mean p53 LI for severe dysplasia was 119·09±56·50. Differences were also observed in the distribution of p53-positive cells between grades of dysplasia, with the development of compact p53-positive foci in severe dysplasia. Mean proliferative indices, as determined by Ki-67 expression, were significantly associated with grade of epithelial dysplasia. Furthermore, there was a significant correlation between p53 LI and Ki-67 score (r2=0·37, P=0·01). It is concluded that altered p53 protein expression is probably an early event in oral carcinogenesis in the floor of the mouth and is associated with dysregulation of cell proliferation at this site. © 1997 John Wiley & Sons, Ltd. 相似文献