Apoptosis occurs independently of bcl-2 and p53 over-expression in non-small cell lung carcinoma

Certain oncogenes and tumour suppressor genes are known to modulate apoptosis. To investigate whether over-expressed bcl-2 and abnormally stabilized p53 are associated with reduced apoptosis in paraffin sections of non-small cell lung carcinoma, apoptotic, mitotic, and Ki-67 labelling indices were determined and correlated with bcl-2 and p53 immunoreactivity in 54 squamous cell carcinomas and 22 adenocarcinomas. Nineteen squamous cell carcinomas (35.2%) showed over-expression of bcl-2, but all 22 adenocarcinomas were bcl-2 negative. Thirty-seven squamous cell carcinomas (68.5%) and 13 adenocarcinomas (59.1%) showed p53 over-expression. Apoptotic tumour cells were identified among p53 positive and bcl-2 positive tumour cells. There was a significant linear correlation between apoptotic indices and mitotic indices. bcl-2 over-expression and p53 over-expression were not associated with attenuated apoptosis, or altered mitotic or Ki-67 labelling indices in either tumour type. Neither bcl-2 nor p53 was of prognostic significance. These results suggest that apoptosis in non-small cell lung carcinoma occurs independently, and is not modulated primarily by, bcl-2 or p53. It is likely that the effects on apoptosis of bcl-2 and p53 are countered by those of other oncogene products and/or additional factors that regulate apoptosis in vivo     

Histologic and immunophenotypic classification of cervical carcinomas by expression of the p53 homologue p63: a study of 250 cases

Recent studies of the p53 homologue p63 indicate that this gene is preferentially expressed in basal and immature cervical squamous epithelium. This study correlated p63 expression with morphologic phenotype and human papillomavirus (HPV) type in a wide range of cervical neoplasms. Two hundred fifty cases of cervical carcinoma, including squamous cell carcinoma (SCCA; n = 178), adenocarcinoma (ADCA; n = 28), adenosquamous carcinoma (ASCA; n = 8), neuroendocrine carcinoma (NECA; n = 15), and other variant or mixed types (n = 21) were studied. Ninety-seven percent of SCCA, 0% of ADCA, and 0% of SCUC showed strong (>75% v <30%) positivity for p63 (P<.001). p63 sharply distinguished SCCA (p63+) from ADCA (p63-), Large-cell, poorly differentiated carcinomas were distinguished as putative glandular (glassy cell) or squamous (lymphoepithelial-like or spindle cell) types based on p63 staining. Eight (73%) of 11 neuroendocrine tumors tested were chromogranin positive; all showed no or low (<30%) levels of p63 immunostaining. Absence of p63 was also associated with a subset of nonneuroendocrine undifferentiated carcinomas. Transitions from squamous to columnar or undifferentiated morphology coincided with loss of p63 expression. A strong association between HPV 16 and p63 positivity was identified because of the colocalization of both within tumors of squamous phenotype. p63 is a powerful marker for squamous differentiation and, when diffusely expressed, excludes a glandular or neuroendocrine differentiation. p63 may be useful for differentiating pure squamous or glandular from adenosquamous carcinomas, tracking shifts in differentiation within tumors, supporting (by its absence) the diagnosis of neuroendocrine carcinomas, and clarifying the spectrum of poorly differentiated carcinomas lacking either squamous or neuroendocrine differentiation.     

Molecular pathology and clinicopathologic features of penile tumors: with special reference to analyses of p21 and p53 expression and unusual histologic features.

OBJECTIVES: To examine the histologic features of p21 in penile tumors and to determine the role of p21 and p53 in the pathogenesis of this group of tumors. METHODS: The clinicopathologic features of 87 patients with penile tumors were studied. The expression of p53 and p21 proteins in 49 cases was investigated by immunohistochemistry. RESULTS: Of the 87 tumors studied, 84 represented primary penile tumors (72 malignant and 12 benign) and 3 represented secondary tumors (2 from bladder, 1 from nasopharynx). The primary malignant penile tumors included 66 surface carcinomas with squamous differentiation (92%), 3 cases of Paget disease (4%), 1 case of Bowen disease (1%), and 2 penile urethral squamous cell carcinomas (3%). The former group was subdivided into squamous cell carcinoma (n = 50), verrucous carcinoma (n = 8), basaloid squamous cell carcinoma (n = 3), adenoid squamous cell carcinoma (n = 3), spindle cell carcinoma (n = 1), and adenosquamous carcinoma (n = 1). The benign tumors were squamous cell papillomas (n = 10) and fibromatoses (n = 2). Expression of p21 and p53 was noted in 40% and 89%, respectively, of the 47 patients with primary surface penile carcinoma with squamous differentiation. Positive p21 and p53 expression was also seen in 2 cases of Paget disease. Staining for p21 was often weak and was found in the suprabasal region of carcinomas with squamous differentiation, while p53 expression was seen in the basal region of squamous cell carcinomas. Preinvasive lesions also showed p21 and p53 expression. An inverse correlation between p53 and p21 expression (p53(+)/p21(-) or p53(-)/p21(+)) was noted in half of the squamous cell carcinomas, 4 of 5 verrucous carcinomas, 2 of 3 basaloid squamous cell carcinomas, and in 1 spindle cell carcinoma. The other cases did not show this correlation. CONCLUSIONS: Penile tumors had different histologic variants and p21/p53 expression patterns. Expression of p21 did play a role in some tumors and could be dependent or independent of p53 expression.     

p53、p21~(WAF1)蛋白在非小细胞肺癌中的表达及其临床意义

目的　探讨原发性非小细胞肺癌中p5 3、p2 1WAF1蛋白表达与临床病理及预后的关系。方法　应用免疫组织化学 (SP法 )方法。共检测非小细胞肺癌 147例 ,其中腺癌 6 6例 ,鳞癌 6 3例 ,腺鳞癌 14例 ,大细胞癌 4例。结果　p5 3蛋白总阳性率为 6 1.2 % (90 / 147) ,腺癌为 5 7.6 % (38/ 6 6 ) ,鳞癌阳性率为 6 3.5 % (4 0 / 6 3) ,腺鳞癌为 71.4% (10 / 14) ,大细胞癌 2例阳性。p2 1WAF1蛋白总阳性率为40 1% (5 9/ 147) ,腺癌为 42 .4% (2 8/ 6 6 ) ,鳞癌为 41.3% (2 6 / 6 3) ,腺鳞癌 2 8.6 % (4 / 14) ,大细胞癌 1例阳性。肺腺癌p5 3蛋白阳性表达与其预后相关 ,6 6例腺癌中 ,生存率低于 3年组和高于 3年组的p5 3蛋白阳性率分别为 75 % (2 1/ 2 8)和 44 .7% (17/ 38) ,差异有显著性意义 (P <0 .0 2 5 )。p2 1WAF1阳性表达与肺癌预后有关 ,p2 1WAF1阳性表达者 3年生存率 (6 4.4% )高于阴性表达者 (4 6 .6 % ) (P <0 .0 5 )。p5 3阳性而p2 1WAF1阴性的非小细胞肺癌患者的预后比p5 3阴性而p2 1WAF1阳性者差 (P <0 .0 1)。结论　检测p5 3蛋白表达可作为判断肺腺癌预后的指标之一 ;检测p2 1WAF1蛋白表达有利于对非小细胞肺癌预后的判断 ;联合检测p5 3、p2 1WAF1蛋白对判断非小细胞肺癌的预后有重要的意义 ,似可作     

Basaloid squamous carcinoma of the oesophagus: a distinct neoplasm with multipotential differentiation

AIMS: Basaloid squamous carcinoma (BSC) is an uncommon variant of squamous cell carcinoma, with its prevalent sites being the hypopharynx, tongue base and larynx. In the oesophagus, BSC is rarer than in the head and neck region. This study was aimed to document the clinicopathological features of BSCs of the oesophagus, and to present their relative incidence and immunohistochemical findings. METHODS AND RESULTS: Eighteen cases of BSC of the oesophagus, comprising 3.6% of 502 oesophageal carcinomas, were reviewed for their pathological and clinical features, and examined for the immunohistochemical expression of neuroendocrine markers, cytokeratins, p53, pRb and bcl-2. Oesophageal basaloid squamous carcinomas tended to be biphasic or multiphasic carcinomas, most commonly with basaloid and squamous components (eight cases), or with additional adenocarcinoma (three cases) or with small cell carcinoma (two cases). Each component was microscopically clearly distinguishable from the others, and metastasized separately, chiefly the basaloid component. The remaining five cases were apparently pure basaloid carcinomas, being characterized by lobules and nests of monotonous round undifferentiated cells with frequent comedo necrosis. They resembled, but were differentiated from, the small cell carcinoma on the basis of neuroendocrine markers and cytokeratin expression. p53, pRb and bcl-2 oncoprotein, which are known to normally present in the basal/parabasal cells of the oesophageal epithelium, were detected in 40-50% of cases, with a heterogeneous expression pattern. The patients were all male, with the age ranging 47-74 years (median 57) and presented at variable stages. The plotted 3 years survival rate was 51%, and the immunohistochemical expression of p53, pRb and bcl-2 was not related to the survival of the patients. CONCLUSION: Basaloid squamous carcinoma of the oesophagus is a peculiar neoplasm with a capacity of multidirectional differentiation, often with heterogeneous oncogene expression, probably reflecting the pluripotential stem cell origin.     

Bcl-2 protein expression in lung cancer and close correlation with neuroendocrine differentiation.

For determination of the cellular distribution of bcl-2 expression in lung cancer and clarification of its correlation with cell neuroendocrine differentiation, Bcl-2 immunostaining was carried out on a large series of formalin-fixed, paraffin-embedded lung cancer samples, and four general neuroendocrine marker and seven peptide hormone stainings were carried out on all Bcl-2-positive squamous cell carcinomas and adenocarcinomas of the lung as well as on 8 pulmonary neuroendocrine carcinomas histologically diagnosed. In addition, 3 small cell lung cancer cell lines were studied by Western blotting. Neuroendocrine differentiation in Bcl-2-negative squamous cell carcinomas and adenocarcinomas was examined with chromogranin A and alpha-subunit of Go protein stainings. Bcl-2 protein was detected in 104/111 small cell carcinomas, 8/8 neuroendocrine carcinomas, 0/6 typical (well differentiated) carcinoids, 23/64 squamous cell carcinomas, 4/65 adenocarcinomas, and all 3 small cell lung cancer cell lines. All 8 neuroendocrine carcinomas, 11 of the Bcl-2-positive squamous cell carcinomas, and all 4 Bcl-2 positive adenocarcinomas expressed multiple neuroendocrine markers. The distributions of Bcl-2 and neuroendocrine marker immunoreactivity closely paralleled each other on consecutive sections. In squamous cell carcinomas, Bcl-2-positive cells could be roughly subdivided into those with neuroendocrine differentiation features, usually demonstrating intense Bcl-2 staining, with basaloid tumor cells usually expressing weak to moderate Bcl-2 staining. The present study clearly shows Bcl-2 protein expression to be remarkably differentially regulated according to histological types of lung cancers and to appear to quite likely be closely associated with neuroendocrine differentiation of tumor cells, indicating that bcl-2 is importantly involved in cell development and differentiation, in addition to protecting cells from apoptosis. Bcl-2 might be usable as a neuroendocrine marker in lung cancers and possibly also in neural-crest-derived tumors.     

p^53,p^21^WAF1蛋白在非小细胞肺癌中的表达及其临床意义

目的 探讨原发性非小细胞肺癌中的ｐ＾５３、ｐ＾２１＾ＷＡＦ１蛋白表达与临床病理及预后的关系。方法 应用免疫组织化学（ＳＰ法）方法。共检测非小细胞肺癌１４７例,其中腺癌６６例,鳞癌６３例,腺鳞癌１４例,大细胞癌４例。结果 ｐ＾５３蛋白总阳性率为６１．２％（９０／１４７）,腺癌为５７．６％（３８／６６）,鳞癌阳性率为６３．５％（４０／６３）,腺鳞癌为７１．４％（１０／１４）,大细胞癌２例阳性,ｐ＾２１     

P63 expression in lung carcinoma: a tissue microarray study of 408 cases.

p63 is a recently discovered member of the p53 family that has been shown to be important in the development of epithelial tissues. p63 may also play a role in squamous cell carcinomas of the lung, head and neck, and cervix, and its expression is increased in these tumors. The purpose of this study was to investigate the expression of p63 in a broad spectrum of histologic types of lung tumors. A total of 441 cases of primary lung tumors with follow-up data were identified, and the paraffin-embedded tissue blocks were used to construct a duplicate core tissue microarray. After review of the tissue cores, 408 cases, consisting of 123 squamous cell carcinomas, 93 adenocarcinomas, 68 large cell carcinomas, 68 classic carcinoids, 31 atypical carcinoids, 11 large cell neuroendocrine carcinomas, and 14 small cell carcinomas, were adequate for analysis. Immunohistochemistry was performed at 2 different laboratories using monoclonal antibody 4A4 to detect the expression of p63, using different staining protocols. p53 expression was also studied with immunohistochemistry using monoclonal antibody DO-7. Kaplan-Meier curves were plotted to compare the survival of p63-expressing versus nonexpressing tumors. A large proportion of squamous cell carcinomas expressed p63 (96.9%), most showing strong positive nuclear immunoreactivity. Expression in other nonsmall cell lung cancers was also present. Thirty percent of adenocarcinomas and 37% of large cell carcinomas showed p63 expression. In the neuroendocrine tumors, an increasing proportion of tumors stained for p63 as tumor grade increased; 1.9% of classic carcinoids, 30.8% of atypical carcinoids, 50% of large cell neuroendocrine carcinomas, and 76.9% of small cell carcinomas were positive. Approximately half of the positively staining neuroendocrine cases showed strong staining. Expression of p63 was of prognostic significance in neuroendocrine tumors (P < 0.0001), with higher-grade tumors more likely to express p63. Correlation between p63 and p53 expression was not observed (P = 0.18) in nonsmall cell lung cancer; however, a significant correlation between the 2 markers was found in neuroendocrine tumors (P < 0.0001). p63 staining was repeated with a different staining protocol, yielding similar results overall but a lower percentage of positive cases (34.2% vs. 48.4% of tumors positive). In conclusion, p63 expression is consistently expressed in squamous cell carcinoma in the lung, but is also expressed in a subset of adenocarcinomas and large cell carcinomas. Pulmonary neuroendocrine tumors also show p63 staining in some instances, particularly in higher-grade tumors, and the majority of small cell carcinomas are p63-positive. These results suggest that p63 may be involved in oncogenesis in a broader range of tumors than was previously thought.     

Expression of bcl-2 in bladder neoplasms is a cell lineage associated and p53-independent event.

AIMS: To investigate bcl-2 and p53 protein expression in hyperplastic, metaplastic and neoplastic epithelia of the urinary bladder in relation to cell lineages (transitional versus glandular epithelia). METHODS: Formalin fixed, paraffin wax embedded archival tissue blocks of 29 transitional cell carcinomas (TCC), 11 adenocarcinomas, five specimens of cystitis glandularis, four papillomas, and seven samples of morphologically normal bladder mucosa were examined immunohistochemically with antibodies specific to bcl-2 and p53. Consecutive sections were used to assess co-expression of the two proteins. RESULTS: bcl-2 protein was expressed heterogeneously in basal cells of the normal transitional epithelium, whereas p53 was rarely detectable in either normal or hyperplastic epithelium. Of the 29 TCCs, 20 (69%) expressed immunodetectable p53 which was positively associated with grade. In contrast, bcl-2 was detected in four (14%) TCCs and its expression was not associated with grade. bcl-2 was expressed constitutively in all five specimens of cystitis glandularis and in all adenocarcinomas; p53 was co-expressed in most of the latter. There was no association between bcl-2 and p53 protein expression in the TCCs. Expression of bcl-2 protein correlated negatively with grade of adenocarcinoma. CONCLUSION: In bladder adenocarcinomas, bcl-2 expression correlated negatively with tumour grade whereas p53 was associated positively with tumour grade. The association of bcl-2 with cystitis glandularis and adenocarcinoma but not TCC suggests that it may be involved in triggering a lineage switch converting transitional epithelium to a glandular phenotype.     

Prognostic significance of anti-apoptosis proteins survivin and bcl-2 in non-small cell lung carcinomas: a clinicopathologic study of 102 cases.

Inhibitors of apoptosis, including bcl-2 and survivin (a novel gene encoding a unique apoptosis inhibitor), regulate cell proliferation by promoting cell survival. Although survivin has been detected in several human cancers, its prognostic significance and relationship to bcl-2 are not well characterized in lung cancer. Tissue sections from 102 non-small cell lung carcinomas (NSCLC) were immunostained using antibodies against survivin and bcl-2. Staining results were correlated with prognostic variables. Immunoreactivity for survivin and bcl-2 was observed in 53% and 21% of NSCLCs, respectively. Fifty-two percent of the 50 squamous cell carcinomas and 54% of the 52 adenocarcinomas expressed survivin. Survivin positivity correlated with tumor stage in squamous cell carcinoma. On univariate analysis, survivin expression correlated with decreased patient survival in NSCLC and in the subset of squamous cell carcinomas, but not in adenocarcinomas. On multivariate analysis, survivin was an independent predictor, along with distant metastasis and large tumor size. Eighteen percent of squamous cell carcinomas and 24% of adenocarcinomas expressed bcl-2. On univariate analysis, bcl-2 expression correlated with increased patient survival in NSCLC and in the subset of squamous cell carcinomas. An inverse correlation between the expression of survivin and bcl-2 was noted. Survivin immunoreactivity is an independent predictor of shortened survival in NSCLC, while bcl-2 protein expression correlated with prolonged patient survival. These findings indicate an inverse relationship between survivin and bcl-2 expression and suggest that these two inhibitors of apoptosis function through different pathways in the regulation of tumorigenesis in NSCLC.     

P53 immunohistochemical expression: messages in cervical carcinogenesis

AIMS: The pattern of p53 expression was studied in pre-invasive and invasive cervical carcinoma in an attempt to clarify its role in cervical carcinogenesis. METHODS: A total of 234 invasive cervical carcinomas (152 squamous cell carcinomas, 61 adenocarcinomas and 21 adenosquamous carcinomas) and 16 cervical intraepithelial neoplasia (CIN) I, six CIN II and 25 CIN III were immunohistochemically studied for p53. RESULTS: p53 was detected more frequently in CIN and invasive carcinoma (100% of CIN I, 74.2% CIN II + III and 70.1% invasive carcinoma) compared with benign cervices (P< 0.001); however, only three squamous cell carcinomas, 11 adenocarcinomas and two adenosquamous carcinomas exhibited p53 expression in >75% of tumour nuclei. Six of the 11 adenocarcinomas and both adenosquamous carcinomas were poorly differentiated compared with one of the three squamous carcinomas. p53 immunoreactive cells were randomly distributed in invasive carcinoma, confined to the lower third of the epithelium in CIN I, reached the middle third in 20% of CIN II and upper third in 16.6% of CIN III. CONCLUSIONS: Assuming that p53 immunoreactivity indicates gene mutation when the majority (> 75%) of neoplastic cells express p53, p53 mutations would seem uncommon in cervical carcinogenesis. Nonetheless, glandular malignancies, in particular poorly differentiated variants, may show a higher frequency of mutation. p53 was detected more frequently in CIN I compared with CIN II/III and invasive carcinoma which may be due to p53 protein degradation following interaction with high risk human papillomavirus E6 protein in CIN II/III and invasive carcinoma.     

非小细胞肺癌组织中细胞凋亡与p53蛋白表达的定量研究

目的 :观察非小细胞肺癌 (NSCLC)组织中Caspases介导的细胞凋亡与p5 3蛋白表达情况 ,探讨两者之间的相关关系和意义。方法 :临床手术切除的NSCLC标本 4 4例 ,其中鳞癌 2 0例 ,腺癌 2 4例。采用Caspase特异的单克隆抗体M30Cy toDEATH免疫组化染色显示凋亡细胞 ,计算凋亡指数 (AI) ;免疫组化法检测p5 3蛋白表达 ,用显微图像分析系统测定阳性细胞百分率 (P/A)、平均光密度 (AOD)及阳性水平指数 (PLI)。结果 :NSCLC组织中M30阳性率为 2 5 0 % ,肺鳞癌组织的M 30阳性率明显高于肺腺癌组织 (P <0 0 5 )。低分化鳞癌组织的AI高于中、高分化鳞癌 (P <0 0 5 )。NSCLC组织中 p5 3蛋白阳性率为 5 2 2 %。p5 3蛋白的PLI与癌细胞AI之间无直线相关关系。 结论 :在NSCLC组织中存在Caspases介导的细胞凋亡机制 ,且与组织学类型及组织分化程度有关。p5 3蛋白表达与癌细胞凋亡无相关关系 ,提示突变型 p5 3蛋白失去了激活Cas pases而诱导细胞凋亡的作用 ,与肺癌的发生、发展、治疗及预后有关。     

Bcl-2 protein expression in carcinomas originating from the follicular epithelium of the thyroid gland

The bcl-2 product has been related to the block of programmed cell death (apoptosis) both in lymphoid and in epithelial cells. The pathological expression of bcl-2 has been investigated mainly in haematological malignancies. Here we have investigated bcl-2 expression in a model of epithelial tumours represented by the spectrum of carcinomas arising from the follicular epithelium of the human thyroid gland. The analysis was carried out by immunocytochemistry on archival material using monoclonal antibodies against bcl-2 and thyroglobulin (Tg) on consecutive sections of 94 well-differentiated carcinomas (WDCs), 19 poorly differentiated carcinomas (PDCs), and 22 undifferentiated carcinomas (UCs) of the thyroid gland. In a subset of 5 cases of UC showing a differentiated component (UC-D), the expression of p53 protein was also investigated. As controls, fetal and adult normal thyroid glands and adenomas were analysed. bcl-2 expression was detected in 74 of 94 cases (78·7 per cent) of WDC, 16 of 19 cases (84·2 per cent) of PDC, and 3 of 22 cases (13·6 per cent) of UC. Simultaneous expression of bcl-2 protein and Tg was observed in 74 of 94 cases (78·7 per cent) of WDC, 13 of 19 cases (68·4 per cent) of PDC, and in no case of UC. bcl-2 and Tg immunostaining was detected in all fetal and normal thyroid glands as well as in the adenoma specimens examined. In the subset of UC-D, mutual exclusion of bcl-2 and p53 expression was observed in the undifferentiated and differentiated components (p53 but not bcl-2 expressed in the former). Our data indicate that within the spectrum of thyroid carcinomas bcl-2 expression, similarly to Tg, is strictly correlated with cell differentiation and that its abrogation is restricted to UCs, in which alterations of the p53 gene represent a late genetic event related to tumour progression.     

Expression of Bcl-2 and p53 correlates with the morphology of gastric neoplasia

The growth of a tumour can be determined by an interplay between cell proliferation and loss. The expression of apoptosis-related proteins (Bcl-2 and p53), cell proliferation (Ki-67), and apoptotic cell death were investigated using immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling in gastric neoplams, to evaluate whether they correlate with the morphology of the tumour. The materials included ten cases of gastric adenoma and 40 cases of early gastric carcinoma consisting of differentiated adenocarcinomas (n=20) and undifferentiated carcinomas (n=20). All cases of adenoma and eight cases of differentiated adenocarcinoma were of the elevated type, while 12 differentiated adenocarcinomas and all of the undifferentiated carcinomas were of the depressed type. The diffuse expression of Bcl-2 was observed in all cases of adenoma and seven out of eight (88 per cent) of elevated-type differentiated adenocarcinoma. In contrast, Bcl-2 expression was absent or focal in the depressed type of carcinoma. Overexpression of p53 was found exclusively in the depressed type of carcinoma. Thus, Bcl-2 and p53 expression was associated with tumour morphology. It seemed unlikely that Bcl-2 and p53 expression was involved in the morphogenesis of the gastric tumours through inhibiting apoptotic cell death, since the degree of apoptosis in Bcl-2-positive gastric tumours was rather higher than that in Bcl-2-negative ones and it did not differ significantly between p53-positive and p53-negative tumours. Instead, the diffuse distribution of Bcl-2 correlated with the superficial distribution of Ki-67-positive proliferating cells, and the overexpression of p53 had a tendency to correlate with the diffuse distribution of proliferating cells. These results suggest that diffuse Bcl-2 expression and a superficial distribution of proliferating cells may contribute to the elevated configuration, and that overexpression of p53 and a diffuse distribution of proliferating cells may result in the depressed configuration in the relatively early stages of gastric tumourigenesis. © 1998 John Wiley & Sons, Ltd.     

The fine structure of large cell undifferentiated carcinoma of the lung. Evidence for its relation to squamous cell carcinomas and adenocarcinomas

The light microscopic diagnosis of large cell undifferentiated carcinoma of the lung is known to be highly subjective and shows poor interobserver reproducibility; the very existence of this tumor as a separate entity has been challenged. The ultrastructure of seven large cell undifferentiated carcinomas was examined in an attempt to determine whether they were merely poorly differentiated adenocarcinomas and squamous cell carcinomas, or actually represented an entirely separate class of tumors. Four large cell undifferentiated carcinomas demonstrated intra- and intercellular lumina and were designated adenocarcinomas. In three cases there were well formed desmosomes with numerous tonofilaments and intercellular bridges. These tumors were classified as squamous cell carcinomas. An eighth tumor metastatic to the abdominal wall also showed the features of squamous carcinoma. In addition, all tumors contained a variable population of primitive cells without identifying features. The large cell undifferentiated carcinomas were compared ultrastructurally with eight cases of poorly differentiated adenocarcinomas and squamous cell carcinomas classified by light microscopy. These tumors were morphologically similar, but contained fewer primitive cells and greater numbers of differentiated cells. Cells with a clear cytoplasm as seen by light microscopy were present in both the large cell undifferentiated and poorly differentiated groups; these cells contained variable amounts of glycogen but were otherwise similar to the nonclear cells. It is suggested that most of the subcategories of large cell undifferentiated carcinoma represent very poorly differentiated adenocarcinomas and squamous carcinomas.     

Patterns of p21waf1/cip1 expression in non-papillomatous nasal mucosa, endophytic sinonasal papillomas, and associated carcinomas

AIMS: To clarify p21(waf1/cip1) expression in sinonasal lesions. METHODS: Archived surgical specimens from 38 patients were investigated by means of immunohistochemistry. p21(waf1/cip1) staining was evaluated in the different layers of the epithelium. In addition, human papillomavirus (HPV) infection and p53 protein overexpression were assessed and correlated with p21(waf1/cip1) expression. RESULTS: p21(waf1/cip1) staining was negative in non-papillomatous nasal mucosa. HPV infection and p53 protein overexpression were not seen. Sixteen of 20 inverted papillomas showed p21(waf1/cip1) expression. HPV infection was found in 16 cases and p53 protein overexpression was present in 13 specimens. Expression of p21(waf1/cip1) was restricted to surface cells in five cases, but involved basal/parabasal cells in 11 specimens. Immunoreactivity for p21(waf1/cip1) in basal/parabasal cells colocalised with p53 protein overexpression. Enhanced expression rates for p21(waf1/cip1) were seen in transitional and squamous epithelium compared with columnar epithelium. p21(waf1/cip1) expression involved only surface cells in cylindrical cell papillomas. HPV infection and p53 protein overexpression were detected in all specimens. One of five squamous cell carcinomas showed p21(waf1/cip1) expression. HPV infection was seen in two cases, and all carcinomas showed p53 protein overexpression. CONCLUSIONS: Expression of p21(waf1/cip1) is associated with terminal differentiation in surface cells in inverted papillomas and cylindrical cell papillomas, but not in non-papillomatous nasal mucosa. Overexpression of p53 protein colocalises with p21(waf1/cip1) expression in basal/parabasal cells in inverted papillomas but not in cylindrical cell papillomas. Expression of p21(waf1/cip1) in squamous cell carcinomas involves a subset of tumours with p53 protein overexpression.     

p21WAF1/Cip1 expression is associated with cell differentiation but not with p53 mutations in squamous cell carcinomas of the larynx

p21^WAF1/Cip1 is a recently identified gene involved in cell cycle regulation through cyclin-CDK-complex inhibition. The expression of this gene in several cell lines seems to be induced by wild-type, but not mutant, p53. p21^WAF1/Cip1 expression has been studied at both mRNA and protein levels in a series of 49 normal mucosae and squamous cell carcinomas of the larynx. A significant association was found between mRNA and protein expression in tumours (P<0·0001). p21^WAF1/Cip1 expression was strongly associated with squamous cell differentiation of carcinomas, because six of seven (86 per cent) undifferentiated carcinomas (grade 4) showed very low levels of p21^WAF1/Cip1 expression, whereas 41 out of 42 (98 per cent) carcinomas with squamous cell differentiation (grades 1–3) had normal or high levels of p21^WAF1/Cip1 expression (P<0·0001). In addition, p21^WAF1/Cip1 expression was topologically related to the squamous differentiation of tumour cells with a distribution similar to that seen in normal squamous epithelium. No correlation was found between p21^WAF1/Cip1 expression and the global S-phase of the carcinomas. p53 mutations (exons 5–9) were found in ten carcinomas with p21^WAF1/Cip1 expression, but no p53 mutations were detected in three p21^WAF1/Cip1-negative tumours. In conclusion, p21^WAF1/Cip1 expression is frequently upregulated in squamous cell carcinomas of the larynx and is associated with tumour cell differentiation. p21^WAF1/Cip1 expression in these tumours is independent of p53 gene mutations. © 1997 John Wiley & Sons, Ltd.     

Epithelial neoplasms of the appendix and colorectum: an analysis of cell proliferation,apoptosis, and expression of p53, CD44, bcl-2

CONTEXT: Carcinomas of the appendix are usually well-differentiated mucinous adenocarcinomas that tend to produce pseudomyxoma peritonei and do not show metastatic spread until late in the disease process. In contrast, adenocarcinomas of the colon and rectum rarely result in pseudomyxoma peritonei and frequently metastasize, even if mucinous and well differentiated. These differences in behavior may be reflected by differences at the molecular level. OBJECTIVES: To examine adenocarcinomas and their precursor lesions (adenomas) of the appendix and colorectum and to determine whether differences exist in the numbers of proliferating and apoptotic cells or in expression of p53, bcl-2, and the standard form of CD44 (CD44s). DESIGN: Retrospective analysis of surgical specimens. SETTING: Multicenter study. PATIENTS: Individuals treated surgically for tumors of the appendix or colorectum. INTERVENTIONS: Sections were cut from formalin-fixed surgical specimens and immunohistochemical tests were performed for Ki-67 (as a marker of proliferating cells), M30 (as a marker of apoptotic cells), p53, CD44s, and bcl-2. MAIN OUTCOME MEASURES: Expression of Ki-67, M30, p53, CD44s, and bcl-2 in tumor cells. RESULTS: The appendiceal adenomas showed significantly lower Ki-67 counts, p53 expression, and bcl-2 expression. When compared with adenocarcinomas of the colorectum in general (mucinous and nonmucinous), the appendiceal adenocarcinomas showed significantly lower Ki-67 counts, M30 counts, and CD44s expression. However, when the analysis was confined to well-differentiated mucinous adenocarcinomas, only the M30 count was significantly different. CONCLUSIONS: The lower proliferative and apoptotic activity of appendiceal carcinomas and the lower CD44s expression are in keeping with their more indolent behavior compared with adenocarcinomas of the colorectum. However, when only the subset of well-differentiated mucinous adenocarcinomas was compared, only the apoptotic activity was different, suggesting that the other differences were related to the morphologic structure of the lesions.     

Bcl-2 and p53 expression in insular and in well-differentiated thyroid carcinomas with an insular pattern

Expression of p53 and bcl-2 oncogenes was investigated in poorly differentiated, so-called insular carcinomas of the thyroid gland and also in the follicular and papillary carcinomas with an insular component. Hematoxylin-eosin sections of 217 thyroid carcinomas were reevaluated for insular carcinoma and also for thyroid carcinomas with an insular component. Immunohistochemical staining method was used for detecting p53 and bcl-2 expression on paraffin blocks of three pure insular, five follicular or papillary thyroid carcinomas with a major insular component (more than 50%) and six with a minor insular component (20–50%). Flow cytometry was also performed in these cases. None of the cases showed p53 immunoreactivity. Bcl-2 expression was observed in all cases and the most intense staining was seen in insular areas. All the cases were diploid. We suggest that bcl-2 plays a role in loss of differentiation of thyroid carcinomas.