Proliferating cell nuclear antigen expression in papillary thyroid carcinoma.

AIMS: To correlate the expression of proliferating cell nuclear antigen (PCNA) with various clinicopathological features of papillary thyroid carcinoma. METHODS: Sections from 131 formalin fixed, paraffin wax embedded papillary thyroid carcinomas were stained with a monoclonal antibody (PC10) directed against PCNA using the avidin-biotin immunoperoxidase (ABC) method. PCNA immunoreactivity was based on the PCNA labelling index (LI) following evaluation of at least 1000 tumour cells, and expressed as follows: grade A (LI < 10%), grade B (10% < or = LI < 25%), and grade C (LI > or = 25%). The relation between PCNA expression in these three groups and other clinicopathological factors, such as sex, age, tumour size, nodal metastases, and histological differentiation, were examined. RESULTS: Based on the labelling index, 57 (43.5%) cases were graded as A, 46 (35.1%) as B, and 28 (21.4%) as C. The female-:male ratios were 6.13:1 for group A, 2.83:1 for group B, and 2.11:1 for group C. The mean (SD) ages of the patients were 39.0 (16.1) in group A, 53.5 (14.4) in group B, and 55.8 (13.3) years in group C. The correlation between age and PCNA grade was strongest in women. CONCLUSIONS: PCNA immunoreactivity is correlated with sex and age in patients with papillary thyroid tumours.     

Co-expression of endothelial cell and macrophage antigens in Kaposi's sarcoma cells

Mutations in the p53 tumour suppressor gene, with consequent accumulation of the p53 protein, are frequently observed in non-small cell lung cancer (NSCLC). Little is known, however, about the timing of their appearance or their maintenance through cancer progression and metastatic spread. We have examined the normal epithelium and a panel of bronchial lesions, including dysplastic, neoplastic, and metastatic leisons, for p53 immunoreactivity and for expression of proliferating cell nuclear antigen (PCNA). No p53 immunoreactivity was found in normal and hyperplastic epithelium, nor in squamous metaplastic lesions. Twenty out of 30 invasive tumours and 13 out of 17 in situ carcinomas adjacent to an invasive tumour showed p53 immunoreactivity. There was a strict correlation between the level of p53 expression in the non-invasive and the invasive components of the tumours. Five out of eight pairs of primary tumours and matching metastases expressed p53, at identical levels in both compartments. These data indicate that p53 overexpression can occur in the earliest recognized phase of NSCLC and that the alteration is maintained during progression from in situ to invasive carcinoma and metastatic spread. PCNA expression increased from early to advanced phases of NSCLC. High PCNA immunoreactivity was observed in tumours expressing high p53 levels. A significant association was observed for PCNA expression between preinvasive and invasive lesions.     

Molecular analysis of p53 gene in laryngeal premalignant and malignant lesions. p53 protein immunohistochemical expression is positively related to proliferating cell nuclear antigen labelling index

This study was undertaken in order to investigate the molecular nature of the p53 gene in 19 laryngeal squamous cell carcinomas and dysplasias. Moreover, we have examined the possible relationship between proliferating cell nuclear antigen (PCNA) expression and p53 protein detection status in 42 laryngeal premalignant and malignant lesions in which 14 of the 19 samples used in the molecular study were included. p53 gene analysis was performed with the single-strand conformation polymorphism technique. PCNA was stained with the peroxidase/antiperoxidase immunohistochemical method using the monoclonal antibody PC-10. Data from previous work concerning p53 expression was used. We found that 9 of 12 of the immunohistochemically p53 positive (+) cases had mutations in exons 5 or 6. In the remaining immunohistochemically p53(+) and p53 negative (–) specimens there was no indication of sequence alterations. Furthermore, we did not observe any deletions in the chromosomal region 17p31.1 which encodes exons 4–8 of the p53 gene. The PCNA labelling index (LI) increased progressively with p53 protein detection status (percentage of cells immunohistochemically positive for p53). The difference between the group with the higher percentage of p53(+) cells and the others was statistically significant. These data show that although there is a discrepancy between immunohistochemical demonstration of p53 and molecular analysis, a large proportion of the former harbours the mutant form of the protein. In addition, p53 overexpression is positively correlated with PCNA LI, a finding which accompanies tumour progression.     

A comparative study on aberrations of chromosome 17 and proliferating cell fraction in lung cancer.

To better understand the relationship between specific chromosome changes found in human lung tumors and their phenotypic consequences a the tissue level, an in situ hybridization (ISH) procedure of chromosome 17 and immunohistochemistry of proliferating cell nuclear antigen (PCNA) were done. The deparaffinized sections were stained with pericentromeric probes for chromosome 17 and an immunohistochemical study of a monoclonal antibody against PCNA were performed. The numbers of chromosome signals were than compared with the positivity of PCNA expression. The mean numbers of chromosome were 1.62 in normal lymphocytes and 2.48 in lung cancer cells. Tumors showed a high mean positivity of PCNA of 43.4%. Mean PCNA expression was higher in squamous carcinomas than in adenocarcinomas (p < 0.05). A linear correlation between numbers of ISH signals and PCNA expression was not demonstrated, but there was a tendency of increasing PCNA positivity according to increasing numbers of ISH signals in adenocarcinomas of the lung and the tumor tissues which were over 50% positive PCNA expression. There was no linear correlation between numbers of ISH signals, PCNA positivity and tumor stages, and keratinization of squamous cell lung cancer. These results suggest that ISH will prove to bo an important tool for determining the underlying genetic basis for tissue phenotypic heterogeneity by allowing genetic determinations to be made on paraffin-embedded tissue sections where histologic architecture is preserved, and immunohistochemical nuclear staining with anti-PCNA on routinely processed tissue is a simple technique for the assessment of proliferation in non-small cell lung carcinoma.     

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     

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     

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。     

Apoptosis-related factors p53, Bcl2, and Bax in neuroendocrine lung tumors.

Neuroendocrine (NE) lung tumors comprise four classes of progressive aggressiveness for which proliferation and apoptosis rates could both contribute to their distinctive behavior. As p53 mutations may favor escape from apoptosis through changes in Bcl2-Bax expression balance, which are survival and apoptotic genes, respectively, we studied 121 NE lung tumors (16 typical carcinoids (TC), 5 atypical carcinoids (AC), 29 large-cell NE carcinomas (LCNECs), and 71 small-cell lung carcinomas (SCLCs) using immunohistochemistry. We quantified apoptosis by terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) in 31 of these cases. There was a significant increase of p53 mutant immunophenotype (defined as immunoreactivity with at least two antibodies for at least 20% of tumor cells) between atypical/typical carcinoids group and the LCNEC/SCLC group (P = 0.0003). There was an inverse correlation (P < 0.0001) between the scores of Bax and Bcl2 expression in individual tumors and a significant inversion of the Bcl2. Bax ratio between low-grade (typical and atypical carcinoids) and high-grade (LCNECs and SCLCs) tumors with a predominant Bax expression in the first group and predominant Bcl2 expression in the second. Whereas carcinoids had variable apoptotic indexes, LCNECs had high indexes (1.3 to 6.8%), Bcl2 overexpression, Bax down-regulation, and Bcl2.Bax ratio > 1 correlated with lower apoptotic index in both LCNEC and the pool of LCNECs and SCLCs (P < 0.05) and a lower survival rate in the group of atypical and typical carcinoids and LCNECs (P < 0.002). The highest levels of Bcl2 expression and Bcl2.Bax ratios were associated with p53 mutant immunophenotype (P = 0.02). Our results suggest that aggressiveness in NE lung tumors could be linked, in addition to proliferation, to apoptosis-related factors.     

Survivin expression in pre-invasive lesions and non-small cell lung carcinoma

Survivin is an inhibitor of apoptosis protein, which is overexpressed in many carcinomas, including lung carcinoma. The aim of this immunohistochemical study was to investigate the role of survivin in the early steps of lung carcinogenesis and non-small cell lung carcinomas (NSCLC), and its relationship with expression of p53 protein, a tumor suppressor gene involved in cell cycle control. In the normal bronchial epithelium, low-grade atypical adenomatous hyperplasia (AAH) and non-neoplastic lung parenchyma adjacent to tumor, survivin was found completely negative. Expression of survivin was detected in the areas of squamous metaplasia and dysplasia as well as high-grade AAH lesions adjacent to tumor. Survivin was expressed in 50 (64%) and p53 in 41 (53%) NSCLC. Survivin expression was significantly correlated with lymph node metastasis (p=0.02). There was no correlation between survivin and p53 expression. The patients with expression of survivin had significantly worse prognosis (Log-rank test, p=0.003). Multivariate Cox regression analysis showed TNM stage (p<0.001) and survivin expression (p=0.003) as independent prognostic indicators. In conclusion, survivin expression might be an early step in lung carcinogenesis. Survivin expression might also be used as a prognostic indicator predicting the worse outcome in NSCLC, and might be a novel target for the treatment of patients with preinvasive lesions of lung and NSCLC.     

Non-small cell lung carcinomas with a minor sarcomatoid component and pleomorphic carcinomas are associated with high expression of programmed death ligand 1

Pleomorphic carcinomas are known to be highly programmed death ligand 1 (PD-L1) positive non-small cell lung cancer (NSCLC) types. However, the level of PD-L1 expression in lung carcinomas with a minor sarcomatoid component, comprising less than 10 % of the tumor mass, has not been determined yet. We hypothesized that NSCLC with a minor sarcomatoid component is more closely related to pleomorphic carcinomas in terms of PD-L1 expression than to NSCLC types without sarcomatoid features. The surgical resections from 690 lung carcinoma patients were retrospectively analyzed for the presence of PD-L1 by means of immunohistochemistry using the 22C3 PharmDx assay. The tumor proportion score system was applied to quantify the level of PD-L1 expression. Membranous staining present in ≥ 1 % of tumor cells was chosen as the cut-off to define a positive result for PD-L1 expression. Tumors were allocated into one of four subgroups: “adenocarcinoma”, “squamous cell carcinoma”, “pleomorphic carcinoma”, or “NSCLC with a minor sarcomatoid component”. PD-L1 expression in pleomorphic carcinomas (26/32, 81.3 %) and in the subgroup of NSCLC with a minor sarcomatoid component (35/46, 76.1 %) was identified in a comparable proportion of cases. Pleomorphic carcinomas were significantly more often PD-L1 positive than adenocarcinomas (p < 0.001) or squamous cell carcinomas (p = 0.0015). Accordingly, the proportion of PD-L1 expressing NSCLC with a minor sarcomatoid component was significantly higher than that of the adenocarcinoma (p < 0.001) or squamous cell carcinoma (p = 0.002) subgroup. In summary, we identified a presumable new subgroup of highly PD-L1 positive neoplasms within the NSCLC spectrum that is related to pleomorphic carcinomas in terms of PD-L1 expression. Further investigation regarding genetic relation and mechanism of PD-L1 expression in these two NSCLC categories is recommended.     

p53, c-myc p62 and proliferating cell nuclear antigen (PCNA) expression in non-Hodgkin's lymphomas.

AIMS--To investigate the immunohistochemical expression of p53 protein in non-Hodgkin''s lymphomas (NHL) and its relation to that of c-myc p62 oncoprotein and proliferating cell nuclear antigen (PCNA). METHODS--Paraffin wax embedded tissue from 90 non-Hodgkin''s lymphomas (72 B cell and 18 T cell) was stained immunohistochemically for p53 protein, c-myc p62 oncoprotein, and PCNA using the monoclonal antibodies DO7, c-myc 1-9 E10, and PC-10, respectively. RESULTS--Of the non-Hodgkin''s lymphomas studied, 55 (61%) stained positively for p53 protein. The proportion of positive cases increased from low grade non-Hodgkin''s lymphoma and was higher in tumours of T cell origin. The percentage of positive cells (labelling index or LI) was significantly lower in low grade non-Hodgkin''s lymphoma, but no difference was established between intermediate and high grade non-Hodgkin''s lymphoma. In a large proportion of low grade non-Hodgkin''s lymphoma the LI was below 1%. c-myc p62 immunoreactivity was identified in all cases. A significant positive correlation was established between p53 LI and c-myc p62 LI (rs = 0.453) as well as between p53 LI and PCNA LI (rs = 0.338). CONCLUSIONS--p53 immunoreactivity was present in about half the cases of non-Hodgkin''s lymphoma and was related to the grade of malignancy and possibly to the B or T cell origin of the tumour. It was also associated with the proliferation state as expressed by PCNA LI and c-myc p62 expression, indicating that the expression of these three cell cycle-related genes might be interrelated.     

Differential expression of hypoxia inducible factor-1 alpha and tumor cell proliferation between squamous cell carcinomas and adenocarcinomas among operable non-small cell lung carcinomas

This study aimed to evaluate whether the elevated level of hypoxia-inducible factor-1alpha (HIF-1alpha) correlated with histologic types, angiogenesis, tumor cell proliferation, and clinical parameters in common non-small cell lung carcinomas (NSCLCs). We performed immunohistochemical stains using paraffin-embedded tissue blocks from 84 cases of operable NSCLC [No. of squamous cell carcinoma (SCC), 45; No. of adenocarcinoma (AC), 39]. HIF-1alpha expression was related with histologic types (66.7% in SCCs vs 20.5% in ACs, p<0.001), but not with lymph node status, tumor stage, vascular endothelial growth factor expression, microvessel density (MVD), and proliferating cell nuclear antigen (PCNA) index (p>0.05, respectively). As for the histologic types, MVD and PCNA index were significantly higher in SCCs than in ACs (p=0.009 and p=0.016, respectively). Among HIF-1alpha positive carcinomas, MVD was significantly higher in HIF-1alpha positive SCCs than in HIF-1alpha positive ACs (p=0.023). The overall survival curves were not associated with HIF-1alpha expression or any other histologic parameters (p>0.05). These findings suggest that HIF-1alpha expression in NSCLCs may play a differential role according to histologic types, but its prognostic significance is indeterminate.     

p53、c-erbB-2、PCNA和EGFR在膀胱癌中过表达及其意义

目的：研究癌基因和抑癌基因蛋白产物在膀胱移行细胞癌中异常表达与病理分级、临床分期、复发和预后的关系。方法：应用免疫组化Ｓ－Ｐ法检查１１７例膀胱移行细胞癌组织中ｐ５３、ｃ－ｅｒｂＢ－２、ＰＣＮＡ和ＥＧＦＲ的表达水平。结果：１１７例膀胱移行细胞癌中ｐ５３、ｃ－ｅｒｂＢ－２、ＰＣＮＡ和ＥＧＦＲ阳性表达率分别为４７．０％、２９．９％、５３．８％和４８．７％。ｐ５３和ＰＣＮＡ阳性表达产物定位于肿瘤细胞核内，ｃ－ｅｒｂＢ－２阳性表达产物定位于细胞膜上，ＥＧＦＲ阳性表达产物定位于细胞膜或细胞浆内。结果表明ｐ５３、ｃ－ｅｒｂＢ－２、ＰＣＮＡ和ＥＧＦＲ异常表达与膀胱癌的分级、分期、复发及术后生存率等之间有统计学意义。结论：ｐ５３、ｃ－ｅｒｂＢ－２、ＰＣＮＡ和ＥＧＦＲ异常表达有助于评估膀胱癌预后，多基因异常表达作为预后评价指标更有意义。     

High expression of MAGE-A9 in tumor and stromal cells of non-small cell lung cancer was correlated with patient poor survival

Melanoma associated antigen-A (MAGE-A) is an oncogene and correlated with tumor initiation and development. However the roles of MAGE-A9 in non-small cell lung cancer (NSCLC) are still unknown. We investigated MAGE-A9 mRNA expression in 18 tumor tissues of NSCLC by qRT-PCR and MAGE-A9 protein expression in 213 NSCLC samples of tissue arrays by immunohistochemical staining. We assessed the relationship between MAGE-A9 expression and clinical parameters. The results showed that the high expression of MAGE-A9 protein in NSCLC tumor cells were commonly present in squamous cell carcinomas (P = 0.030). It was also related to larger tumor diameter, lymph node metastasis and later stage grouping with TNM classification (all P < 0.05). Whereas the expression of MAGE-A9 in stromal cells was higher in squamous cell carcinomas as well. Cox regression univariate and multivariable analysis revealed that MAGE-A9 expression in tumor cells of NSCLC (P < 0.001) is an independent prognostic factor in five-year overall survival rate. We concluded that the molecular assessment of MAGEA9 could be considered to improve prognostic evaluation and to identify eligible patients for potential target therapy.     

p53 Protein,PCNA staining,and DNA content in follicular neoplasms of the thyroid gland

Forty-nine follicular adenomas and 11 follicular carcinomas of the thyroid were investigated by immuno-histochemistry for the expression of p53 protein and proliferating cell nuclear antigen (PCNA). The DNA ploidy and the S-phase fraction (SPF) of the neoplasms were analysed by flow cytometry. Twelve adenomas (24 per cent) and six carcinomas (55 per cent) were DNA non-diploid (P=0·07). The carcinomas had a higher proliferation rate than the adenomas when assessed either by SPF size (median 9·9 per cent vs. 2·9 per cent, P=0·0003) or by PCNA staining intensity (P<0·0001). Some scattered nuclei in two (4 per cent) adenomas and in three (27 per cent) carcinomas stained positively for p53 (P=0·04). The two adenomas with positive staining for p53 were subserially sectioned, but no signs of invasion were found; both patients are alive and well 6 and 7 years after surgery. One of the two adenomas showing positive p53 nuclear staining was DNA aneuploid, and both were positive in PCNA staining, but their SPFs were low (2·1 and 3·3 per cent). We conclude that p53 protein expression is not confined to follicular carcinomas; scattered p53-positive cells may also be present in histologically and clinically benign follicular adenomas. Because both follicular adenomas and carcinomas may be DNA aneuploid and their SPF and PCNA staining distributions overlap, the distinction between follicular adenoma and carcinoma should still be based on histological criteria.     

Association of p53 expression with prognosis in patients with esophageal squamous cell carcinoma

It has been well accepted that p53 overexpression is associated with advanced stages of cancer. However, the prognostic role of p53 overexpression in esophageal squamous cell carcinoma (ESCC) remains unclear. To investigate the prognostic role of p53 overexpression in patients with ESCC, a retrospective cohort study of 136 ESCC patients was carried out. The expression of p53 protein in tumor tissues was investigated immunohistochemically. Positive expression of p53 protein was detected in 57 ESCC patients (41.9%). The p53 overexpression was associated with smoking (P < 0.001), tumor differentiation (P < 0.001), and tumor size (P < 0.001). In the Kaplan-Meier analysis, patients with p53 overexpression had significantly shorter overall survival than those patients with negative p53 expression (log-rank P < 0.001). Multivariable analysis by Cox regression model further showed that p53 overexpression was a significantly independent predictor of poorer overall survival (hazard ratio [HR] = 1.91; 95% confidence interval [95% CI] 1.03-3.54, P = 0.04). Thus, p53 overexpression is associated with poor prognosis in patients with early stage esophageal squamous cell carcinoma, and it’s a significantly independent predictor of poorer overall survival.     

膀胱移行细胞癌细胞周期调节相关基因表达与肿瘤生物学行为的关系

目的：探讨细胞周期调节相关基因p16INK4,p21WAF／CIP1,p53mlt在膀胱移行细胞癌中的表达与肿瘤增殖能力,病理分级及临床分期的关系。方法：应用免疫组织化学技术分析77例膀胱移行细胞癌组织p16INK4,p21WAF/CIP1,p53mlt基因的表达和增殖细胞核抗原（PCNA）表达情况,并与病理分级及临床分期之间进行综合分析。结果：p16INK4,p21WAF/CIP1,p53mlt在膀胱移行细胞癌中的表达及PCNA增殖指数与肿瘤的病理分级有关,与临床分期无关。p16,p21,p53阳性组与阴性组分别比较,其PCNA增殖数之间有差异性。多因素分析发现,p16INK4和p21WAF／CIP1阴性及p53mlt阳性组的PCNA值明显高于p16INK4和p21WAF／CIP1阳性及p53mlt阳性组,两者比较不同病理分级的阳性表达构成比亦有显著性差异。结论:联合检测p16INK4,p21WAF/CIP1,p53mlt基因的表达情况能充分反映膀胱移行细胞癌的增殖能力及生物学行为,对膀胱移行细胞癌患者的预后判断及治疗有指导意义。     

Analysis of p21Waf1/Cip1 expression in normal, premalignant, and malignant cells during the development of human lung adenocarcinoma.

Our studies suggested that adenocarcinoma of the peripheral lung mostly develops by several steps from atypical adenomatous hyperplasia through early adenocarcinoma to overt adenocarcinoma, and that some p53 abnormalities play an important role in this progression. In the present study, we examined by immunohistochemistry the expression of p53-inducible cyclin-dependent kinase inhibitor p21Waf1/Cip1 (p21) in the cells at various developmental stages of lung adenocarcinoma (32 lesions of adenomatous hyperplasia, 14 of early adenocarcinoma, 23 of well differentiated adenocarcinoma, and 17 of moderately or poorly differentiated adenocarcinoma) in comparison with 19 reactive proliferative lesions and analyzed the relationship between p53 and p21 expression. Bronchioalveolar cells in the normal lung expressed very little or no p21 and no p53 expression. In not only reactive but also neoplastic lesions regardless of their developmental stage, the cells expressed p21 at various frequencies. The average labeling indices ranged from 5.4 to 13.8%, and there was no significant difference between any of these categories. The expression of p21, however, tended to be relatively low in moderately and poorly differentiated adenocarcinomas (5.5%) compared to well differentiated adenocarcinomas (12.2%), and high-level p21 expressors (10% < or = positive cells) were more frequent in the latter group (1 of 17 (6%) versus 3 of 23 (35%), P < 0.05), suggesting that p21 expression is affected by the degree of differentiation of the neoplastic cells. Although the correlation was positive between the expression of p21 and p53 in reactive lesions (r = 0.88; P < 0.001), none was found in neoplastic lesions at any step or grade (-0.12 < or = r < or = 0.26). These results indicated that p21 expression depends upon p53 expression in reactive lung cells, whereas p21 expression is at least in part independent of that of p53 from the earliest to the most fully developed step of lung adenocarcinoma tumorigenesis. We concluded that disruption of the p53-dependent cell cycle regulation is a very early event in the tumorigenesis of lung adenocarcinoma.     

Helicobacter pylori and Epstein-Barr virus infection and the p53 tumour suppressor pathway in gastric stump cancer compared with carcinoma in the non-operated stomach.

AIM: To evaluate similarities and differences between gastric stump cancer and conventional carcinoma in the non-operated stomach. METHODS: 26 stump carcinomas were compared with 24 conventional stomach cancers. Stage, histological type, and demographics were comparable in the two groups. Expression of p53 and p21-Waf1/Cip1 was evaluated by immunohistochemical staining. Helicobacter pylori infection was evaluated by examining haematoxylin-eosin stained slides and immunohistochemistry. Epstein-Barr virus infection was evaluated by RNA in situ hybridisation. RESULTS: Expression of p53 and p21-Waf1/Cip1 was similar in both groups and positive in more than half of the patients. H pylori infection was observed in six stump carcinomas and 17 conventional carcinomas in the intact stomach (p < 0.01). RNA in situ hybridisation (EBER1-ISH) for Epstein-Barr virus was positive in nine stump carcinomas and two carcinomas in the non-operated stomach (p < 0.05). CONCLUSIONS: There appear to be aetiological differences between stump carcinoma and cancer in the intact stomach. Further study of these differences may improve our understanding of gastric carcinogenesis in general.