Immunohistochemical analysis of p53 expression in anal squamous neoplasia.

AIMS--To determine the pattern of expression of the p53 tumour suppressor gene product in anal squamous neoplasia, and to determine if this could be used as a marker of disease progression. The association between p53 expression and human papillomavirus (HPV) 16 DNA status of the anal lesions was also investigated. METHODS--The presence and localisation of the p53 protein in formalin fixed, paraffin wax embedded specimens of anal squamous epithelium (normal and neoplastic) was examined using immunohistochemical staining with a panel of two monoclonal antibodies (DO-1, DO-7) and one polyclonal antibody (CM-1). Thirty nine normal anal epithelia, 14 anal intraepithelial neoplasia (AIN) grade 1, seven AIN 2, and 20 AIN 3 specimens were obtained from patients without demonstrable invasive disease; twelve AIN 3 specimens adjacent to invasive disease and 34 anal squamous cancers were also examined. Genomic DNA from all 126 specimens was extracted and analysed for HPV 16 DNA using the polymerase chain reaction (PCR). RESULTS--Nuclear p53 was strongly expressed in 67% (23/34) of invasive anal squamous tumours, 75% (9/12) of AIN 3 specimens adjacent to invasive disease, and in 60% (12/20) of AIN 3 specimens obtained from patients without demonstrable invasive disease. Two of the patients in the latter group with positively staining specimens subsequently developed invasive tumours which had staining characteristics similar to those of the AIN 3 specimens. p53 protein was expressed in very low concentrations in low grade AIN and not at all in normal anal squamous epithelium. In those specimens which stained positively for p53, HPV 16 DNA sequences were detected in 69.5% (16/23) of invasive disease, 77.7% (7/9) of AIN 3 adjacent to invasive disease, 75% (9/12) of AIN 3 obtained from patients without demonstrable invasive disease, 33.3% (2/6) of AIN 2, and in 40% (2/5) of AIN 1. There was no significant correlation between p53 immunostaining and HPV 16 DNA status (p < 0.05). CONCLUSIONS--Aberrant expression of the p53 gene product is probably involved in the pathogenesis of anal squamous neoplasia. Long term follow up studies of all patients with AIN are required to determine if this could be used as a marker of likely disease progression from high grade AIN to invasive disease. There does not seem to be an association between the presence or absence of HPV 16 DNA sequences and mutant p53 proteins in anal squamous neoplasia.     

Keratin expression in the normal anal canal

The pattern of epithelial keratin expression in the normal anal canal has not been extensively defined and is a necessary prerequisite to the interpretation of alterations in these intermediate filaments in pathological anal epithelial lesions. Thirty-five frozen tissue specimens of resected haemorrhoids were investigated immunohistolo-gically for expression of 14 individual keratins (K) using a panel of 17 monoclonal antibodies. Perianal skin showed basal expression of karatinocyte Ks 5, 14 and 17, and suprabasal expression of keratinocyte Ks 14, 10, 1 and 16. Anal squamous epithelium showed persistent basal K5 and 17, basal and suprabasal K4, 13 and 16 positivity, with sporadic expression of K1 and 10. The expression of simple epithelial keratins in squamous epithelium adjacent to the anal transitional zone varied with basal expression of K7, K8, K18 and K19 and sporadic suprabasal expression of K7 and K19. The anal transitional zone (ATZ) expressed K19, as found in transitional epithelia elsewhere. The full thickness of epithelium was positive for the simple epithelial Ks 7, 8 18 and 19. Marked heterogeneity of keratinocyte keratin expression was seen. Basal layers expressed Ks 4, 13, 14 and 17 and variably K16, while suprabasal layers expressed Ks4 and 13, 14 and 17 and variably K16, while suprabasal layers expressed Ks4 and 13 and variably K14, 16 and 17. This anomalous expression of keratinocyte K4 and 13 has also been documented in transitional epithelium of the bladder. The anal glands and ducts showed a keratin distribution similar to the transition zone. Rectal columnar epithelium expressed simple keratins 7, 8 18 and 19. In addition, low levels of keratinocyte keratins were found as indicated by heterogeneous staining for K4, 13, 14 and 16. The overall pattern, particularly in the region of the anal transitional zone and immediately adjacent squamous and columnar epithelia, is of a flexible epithelial cell population able to express a range of keratins unrestricted by a particular morphological phenotype. In the light of these results, analysis of changes in keratin distribution within anal carcinomas may assist classification by providing information on the state of differentiation and histogenesis of these tumours.     

p53 expression, p21 expression and the apoptotic index in endometrioid endometrial adenocarcinoma

AIMS: Although several genetic abnormalities are known to occur in endometrial cancer, including tp53 gene mutation, the pathogenesis of this common malignancy remains poorly defined. We investigated the relationship between overexpression of p53 protein, p21 protein expression and apoptosis in endometrial carcinoma. METHODS AND RESULTS: Sixteen cases of endometrial carcinoma in which polymerase chain reaction analysis had demonstrated the absence of a tp53 gene mutation were selected on the basis of p53 protein expression; p21 protein expression and the apoptotic index were then determined for each case. The proportion of cells in each case expressing p53 and p21 protein immunoreactivity was compared with the apoptotic index. Overall, no significant correlation was demonstrated between p53 and p21 immunoreactivity, or between either p53 or p21 and the apoptotic index. CONCLUSIONS: Factors other than p53 are involved in the regulation of p21 expression and apoptosis in endometrioid endometrial adenocarcinomas without p53 mutations. Despite the small numbers used in this study, the data suggest a correlation between low levels of p53 immunoreactivity and apoptosis. We postulate that high levels of p53 immunoreactivity may be due to abnormal stabilization of the p53 protein. Follow-up studies are needed with a larger data set.     

Epidermal growth factor receptor expression in anal canal carcinoma

Most anal canal carcinomas (ACCs) are squamous cell carcinomas (SCCs). SCCs in other tumor sites strongly express epidermal growth factor receptors (EGFRs), the inhibition of which might result in favorable changes in tumor growth. A review of the published scientific literature reveals no information regarding the expression of EGFR in ACCs. Therefore, we obtained archived pathology samples from ACC biopsies and examined the frequency and level of expression of EGFR and other cell surface and cell cycle markers. The 21 samples studied universally and strongly expressed EGFR and were negative for HER-2. Clinical studies of EGFR inhibitors in advanced ACC are warranted.     

Immunohistochemical expressions of cytokeratins, mucin core proteins, p53, and neuroendocrine cell markers in epithelial neoplasm of appendix

Epithelial neoplasms of appendix are infrequent, and their pathological features are not fully characterized. We collected 33 cases of appendiceal tumors and examined immunohistochemically the expression of cytokeratins (CK, CK7, and CK20), mucin core protein (MUC1, MUC2, MUC5AC, and MUC6), E-cadherin, chromogranin A, and p53 protein. Gene analysis of TP53 was also conducted on exons 5 to 8. Clinically, mucinous tumors were predominant in females. Immunohistochemically, all the tumors expressed CK20, whereas CK7 was positive in one third of the cases. Similarly, MUC2 was expressed in all the tumors, whereas MUC1 and MUC5AC were detected in about a half of the cases. Although chromogranin A-positive cells are generally sparse in normal appendix, they were more common in mucinous tumors than in nonmucinous tumors. Contrary to the previous data reported (Mod Pathol 2002;15:599-605), mucinous carcinoma exhibited a higher frequency of p53-positive cells (mean 29%) compared with mucinous adenoma (2.8%) (P < .001), whereas nonmucinous tumors showed high levels of p53-positive cells to similar extent (51%-67%) in both adenoma and carcinoma. The high expression of p53 protein coincided with the presence of mutations in multiple sites of TP53 gene in mucinous tumors. This is the first report that characterized the immunophenotypic profile of appendiceal epithelial neoplasms with an emphasis of a higher frequency of p53 positivity in mucinous carcinoma cases compared with mucinous adenoma in the appendix.     

Bcl-2 and p53 protein expression, apoptosis, and p53 mutation in human epithelial ovarian cancers

Bcl-2 and p53 gene products have been both linked to cell death by apoptosis. In the present study, we examined the relationship of Bcl-2 and p53 protein expression, p53 mutation and apoptosis in normal human ovaries and different types of human ovarian epithelial tumors by immunohistochemical localization, in situ terminal transferase-mediated dUTP nick end labeling and polymerase chain reaction-single strand conformation polymorphism. It was found that Bcl-2 expressed strongly in the surface epithelium of normal ovaries and benign and borderline ovarian tumors but weakly in the malignant tumors. On the contrary, strong protein expression of p53 was found in 54% (25/46) of the malignant epithelial tumors examined but similar expression of p53 was not observed in borderline and benign tumors and normal ovarian surface epithelium. A significant inverse correlation between Bcl-2 and p53 expression was found in the malignant ovarian tumors examined. p53 gene mutation at exons 5-11 was however not a pre-requisite for p53 expression in both borderline and malignant tumors. Apoptotic activities, as reflected by apoptotic indices, were low in normal ovarian surface epithelium and benign tumors but were increased in borderline and malignant tumors, with the highest average apoptotic index found in grade III malignant tumors. Statistical analyses showed a positive correlation between apoptosis and p53 expression, but similar correlation was not found between apoptosis and Bcl-2 expression. Our results also indicate that although expression of Bcl-2 is important during ovarian carcinogenesis, the Bcl-2 protein may have other roles to play apart from being a modulator of apoptosis in human ovarian epithelial cancers.     

Intratumoral heterogeneous expression of p53 correlates with p53 mutation,Ki-67, and cyclin A expression in endometrioid-type endometrial adenocarcinomas

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.     

Cancer of the anal canal

Seventy-four carcinomas of the anal canal (4,9% of the total number of rectum carcinoma for 1952-1982) were studied, including 45 squamous-cell, 23 adenogenic and 6 undifferentiated carcinomas. Adenogenic carcinomas originated from the rectum mucous membrane over the serrated line; as distinct from carcinomas of other parts of the rectum the mucus-forming and poorly differentiated tumours were predominant among them. Squamous-cell carcinomas originated from the squamous epithelium of the lower part of the anal canal, from the transitional area and from the rectum mucous membrane over the serrated line. They were characterized by peculiarity of their histological structure: they included 11 basaloid carcinomas, 6 carcinomas resembling transitional-cell carcinoma of the urinary bladder, 12 carcinomas resembling carcinoma of the uterine cervix. The problems of the terminology, histogenesis, clinical course of the anal canal carcinoma are discussed.     

Carcinoma of the anal canal

Despite the rarity of carcinoma of the anal canal, remarkable progress has been achieved during the past 30 years in understanding its pathogenesis and improving treatment. Largely because of the rigorous collection of data and the treatment of patients in clinical trials, it is now widely accepted that the majority of cases are caused by human papillomavirus and can be cured by combination therapy. Concomitant treatment with external-beam radiation therapy and chemotherapy with fluorouracil and mitomycin represents the standard approach to combination treatment. Appropriate cytologic screening of high risk populations and the integration of platinum compounds into treatment regimens will most likely reduce mortality from this disorder even further.     

Endocrine cells in the anal canal

Summary Endocrine cells are normal inhabitants of the anal canal. While numerous endocrine cells are distributed throughout anal ducts and crypts, few are dispersed in the anal transitional zone. All these cells were characterized as serotonin-storing cells, and this endocrine profile is quite distinctive from that of adjacent mucosae. Rectal epithelium contains serotonin, somatostatin, enteroglucagon, BPP and HPP immunoreactive cells; endocrine cells are lacking in the pectinal folds and perianal skin. It is suggested that this distinctive hormonal profile may be regarded as a specific marker of this anal territory. The same pattern is found in the fetal transitional lining of anal canal.Evidence of serotonin-storing cells in the transitional epithelium of anal glands and crypts and in the ATZ epithelium, reinforces the homology between these linings and urothelium. The presence of a similar fetal epithelium implies that ATZ epithelium in adults is not necessarily metaplastic. All derivatives of the cloaca may therefore share the same endocrine profile.     

Neuronal hyperplasia in the anal canal

In a consecutive series of minor surgical specimens from the anal canal, neuronal hyperplasia was found in nine of 56 haemorrhoidectomy specimens and in four of 23 fibrous polyps. In an additional series of 14 resections of the anal canal, neuronal hyperplasia was present in six cases, of which five showed haemorrhoids. In all cases, neuronal hyperplasia was located in the submucosa beneath squamous epithelium and extended over an area from 5 to 12 mm. Immunohistochemically, the foci of hyperplasia were found to consist of both neuronal and Schwann cell components. Staining for vasoactive intestinal peptide, neuropeptide Y and calcitonin gene related peptide, did not demonstrate any increased terminal density. It is suggested that anal neuronal hyperplasia in these cases represents an acquired lesion due to local mechanical influence.     

膛胱移行细胞癌中c—erbB—2,p53及p16蛋白的表达

目的 探讨膛胱癌组织中ｐ１６、ｃ－ｅｒｂＢ－２和ｐ５３蛋白表达与胱癌病理分级、临床分期和转移的关系。方法 应用免疫组化ＳＰ法对７５例膛胱癌组织中ｐ１６、ｐ５３及ｃ－ｅｒｂＢ－２蛋白表达进行检测。结果 ７５例膛胱癌中ｐ１６、ｐ５３及ｃ－ｅｒｂＢ－２的阳性率分别为４１．３％（３１／７５）、４４．０％（３３／７５）和４０．０％（３０／７５）,ｐ１６和ｃ－ｅｒｂＢ－２蛋白在膛胱癌中的阳性率与肿瘤中的阳性率     

Cytokeratin polypeptide expression in a cloacogenic carcinoma and in the normal anal canal epithelium

Summary The aim of the present study was to explore the origin of cloacogenic carcinoma in the anal canal by immunohistochemical methods. We compared cytokeratin polypeptide expression of a cloacogenic carcinoma to normal anal epithelia, to anal squamous cell carcinoma and to basal and squamous cell carcinoma of the skin, using a battery of monoclonal anti-cytokeratin, polypeptide-specific antibodies. Our results indicate that cloacogenic carcinoma expresses cytokeratin polypeptides similar to those of the basal layer of anal squamous epithelium, of the anal transitional zone epithelium and of a layer of basal cells in the anal glands. Thus we concluded that each of the above cell types may be the cell of origin of cloacogenic carcinoma.     

膀胱移行细胞癌中c-erbB-2、p53及p16 蛋白的表达

目的　探讨膀胱癌组织中p16、c erbB 2和p5 3蛋白表达与膀胱癌病理分级、临床分期和转移的关系。方法　应用免疫组化SP法对 75例膀胱癌组织中p16、p5 3及c erbB 2蛋白表达进行检测。结果　 75例膀胱癌中p16、p5 3及c erbB 2的阳性率分别为 41.3% (31 75 )、44 .0 % (33 75 )和40 0 % (30 75 ) ,p16和c erbB 2蛋白在膀胱癌中的阳性率与肿瘤病理分级和临床分期有显著意义 (P<0 0 5 ) ,p5 3和c erbB 2阳性率与肿瘤临床分期及转移有密切的关系 (P <0 .0 1)。 77.3% (5 8 75 )肿瘤有上述蛋白的阳性表达 ,其中 5 3.3% (40 75 )的肿瘤同时有多个蛋白的阳性表达。结论　肿瘤的多因素分析比单因素分析更有价值 ,癌基因c erbB 2和抑癌基因p5 3、p16蛋白的表达异常及协同作用在膀胱癌的发生发展中起重要作用     

膀胱肿瘤中p53,p21,C—erbB—2癌基因表达及T细胞亚群研究

目的：探讨ｐ５３,ｐ２１,Ｃ－ｅｒｂＢ－２表达与膀胱癌生物学行为的关系以及膀胱癌患者外周血Ｔ淋巴细胞亚群的变化。方法：应用免疫组化ＬＳＡＢ技术,检测膀胱癌相关癌基因ｐ５３,ｐ２１,Ｃ－ｅｒｂＢ－２的基因表达。结果：ｐ５３,ｐ２１,Ｃ－ｅｒｂＢ－２阳性表达率随病理分级上升而上升;当润性癌ｐ５３,ｐ２１,Ｃ－ｅｒｂＢ－２的阳性表达强度高于浅表性癌;     

不同部位恶性黑色素瘤DNA倍体分析和PCNA、p53蛋白的表达及其意义

目的对不同部位恶性黑色素瘤（malignant melanoma,MM）的DNA倍体、PCNA阳性指数及p53蛋白的表达作对比性分析,探讨其与预后的关系。方法31例MM按部位、临床复发情况分为眼球脉络膜组、皮肤组、中轴腔黏膜组及复发组,对它们进行激光扫描细胞术DNA倍体分析、PCNA和p53蛋白表达的检测,结合随访,作各组间比较。结果PCNA阳性百分率在脉络膜MM中最低,其次为皮肤MM,中轴腔黏膜MM更高,复发组最高,各组间差异有显著性（P〈0．01）;各组死亡率也呈同样增长趋势;异倍体在前两组中发生率低,而在后两组中各占50％。绝大多数MM不表达p53蛋白,仅在部分复发MM中可检测到p53。结论不同部位MM的PCNA指数、异倍体比例及存活率是不同的,它们之间有一定关联;复发的MM中PCNA指数、异倍体的比例最高,并表达p53蛋白。测定PCNA和异倍体对判断MM的预后有意义。     

Melanocytes in the anal canal epithelium

We studied the presence of melanocytes in the various epithelial zones of the anal canal, using a recently introduced melanocyte-specific antibody (HMB-45) together with antibody to S-100 protein. In normal and canals and in haemorrhoids, melanocytes, defined as intraepithelial HMB-45/S-100 positive cells, were frequently demonstrated in the anal squamous zone, only sporadically in the anal transitional zone, and not at all in the colorectal zone. In the epithelium surrounding, but clearly separated from, resected primary anal malignant melanomas, increased numbers of benign melanocytes were demonstrated in the squamous zone and transitional zone, but also in the colorectal zone. We interpret this finding as a tumour-induced proliferation of benign melanocytes normally present, but in very small numbers or in some way 'masked', in the epithelium of the upper anal canal. The demonstration of melanocytes in all three zones of the anal canal substantially supports the observation that malignant melanoma of the anal canal may originate not only below but also above the dentate line.