Expression of MUC1 and MUC2 mucins and relationship with cell proliferative activity in human colorectal neoplasia

Our previous studies on MUC1 and MUC2 mucin expression in various human neoplasms have found that MUC1 expression is related with a poor outcome whereas MUC2 expression is related with a favorable outcome. In the present study, we examined the alteration of MUC1 and MUC2 antigens on malignant transformation of colorectal mucosa, and also its relationship with cell proliferative activity (Ki-67 labeling index) of neoplastic epithelial cells in 200 adenomas and 58 carcinomas. In the 200 adenomas, we analyzed a total of 400 adenomatous lesions (mild dysplasia, 200 lesions; moderate dysplasia, 153 lesions; severe dysplasia, 47 lesions). MUC1 was expressed in carcinomas (24%) and adenomas with severe dysplasia (4%), but was not expressed in adenomas with mild or moderate dysplasia. MUC2 was expressed in a significantly greater number of adenomas with mild dysplasia (72%) than in adenomas with moderate dysplasia (45%) or severe dysplasia (47%), as well as in the carcinomas (38%; P < 0.0001). The Ki-67 labeling index was significantly lower in the MUC2-positive cases than in the MUC2-negative cases in the adenomas with mild dysplasia (13.6 vs 24.2%; P < 0.0001) or moderate dysplasia (25.7 vs 44.4%; P < 0.0001), and in the carcinomas (32.5 vs 48.4%; P < 0.05). In conclusion, the data from our study indicate that increased MUC1 expression and reduced MUC2 expression may be related to malignant transformation of colorectal neoplasia. We also demonstrated that decreased MUC2 expression, which is correlated with increased Ki-67 labeling, may play an important role in the progression of colorectal adenomatous change.     

Apoptosis in human gastric mucosa, chronic gastritis, dysplasia and carcinoma: analysis by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling

We examined the existence and distribution of apoptotic cells in human gastric mucosa, chronic gastritis, adenomatous dysplasias and carcinomas in 15 surgically removed stomachs in which dysplasia and carcinoma were found simultaneously. Serial sections were cut for immunohistochemistry for p53 oncoprotein and Ki-67 antigen, and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labelling (TUNEL). TUNEL signal-positive apoptotic cells were rare in normal mucosa, while a few apoptotic cells were noted in gastritic mucosa and intestinal metaplasia, intermingled with Ki-67 antigen-positive cells forming a generative cell zone. This suggests the cell-cycle-dependent apoptosis of gastric mucosa. The frequency of apoptotic cells per crypt was higher in incomplete than in complete metaplasia, implying greater underlying DNA damage in the former. TUNEL indices (TI; percentage of TUNEL-positive cells in tumour cells) were slightly higher in adenomatous dysplasias (4.9±2.1) than in carcinoma (3.9±1.1), but there was no no statistical difference. Ki-67 indices (KI; percentage of Ki-67 antigen-positive cells in tumour cells) were significantly (P<0.05) higher in carcinomas than in dysplasias. Thus, gastric adenomatous dysplasias were characterized by relatively higher TI and lower KI, which might reflect a more static growth potential. The expression of p53 oncoprotein in cancer cells is thought to be an apoptosis-suppressing event, although its precise role remains to be elucidated. Overall, these results indicate that apoptosis plays a crucial part in the morphogenesis of gastritic mucosa including intestinal metaplasia, and that the process is correlated both with tumourigenesis and with proliferative activity.     

Apoptosis regulation differs between ulcerative colitis-associated and sporadic colonic tumors. Association with survivin and bcl-2

To clarify kinetics in ulcerative colitis (UC)-associated lesions, cell proliferation, apoptosis, and expression of apoptosis-inhibitory proteins were studied. Ki-67 labeling and survivin and bcl-2 expression were examined immunohistochemically in 22 low-grade dysplasias (LGDs), 25 high-grade dysplasias (HGDs), and 13 adenocarcinomas associated with UC, and for comparison in 21 sporadic adenomas with LGD, 22 sporadic adenomas with HGD, and 21 invasive adenocarcinomas. Apoptosis was studied with nick-end labeling and immunohistochemical analysis of single-stranded DNA. In UC-associated LGDs, Ki-67--positive cells were more frequent in the lower than the upper half of the crypt, related to bcl-2 expression, while in sporadic adenomas such cells were more common in the upper half. No difference in apoptosis was found between UC-associated LGDs and sporadic adenomas with LGD or between UC-associated HGDs and sporadic adenomas with HGD. However, UC-associated carcinomas exhibited a lower apoptotic count than their sporadic invasive counterparts. This seemed related to higher survivin expression without a significant difference between the 2 types of invasive lesions regarding bcl-2 levels. Apoptosis is less frequent in UC-associated than in sporadic invasive colon carcinomas, this being linked to elevated survivin expression. The control of apoptosis may be different in the 2 types of tumorigenesis.     

Morphogenesis of nonpolypoid colorectal adenomas and early carcinomas assessed by cell proliferation and apoptosis

Nonpolypoid neoplasms, as well as ordinary polypoid tumours, are occasionally found in the colorectum. To clarify whether cell kinetic status affects the macroscopic morphology of colorectal neoplasms, we investigated proliferative indices (PI), apoptotic indices (AI), and the expression of apoptosis-related gene products. We examined 110 colorectal neoplasms comprised of 36 polypoid, 38 flat elevated and 36 depressed tumours. According to WHO’s criteria these tumours consisted of 61 adenomas with low grade dysplasia (LGD), 30 adenomas with high grade dysplasia (HGD) and 19 carcinomas with submucosal invasion. Apoptotic cells were detected by TUNEL staining. Proliferating cells and apoptosis-related gene products were assessed by immunohistochemistry for Ki-67, p53, Bcl-2, and Bax antigens. AI were closely associated with macroscopic morphology in adenomas but not in carcinomas. PI were relatively constant among the three macroscopic types in adenomas and carcinomas. Median AI values of polypoid, flat elevated and depressed tumours were 1.8%, 2.1% and 4.6% for adenomas with LGD, 0.8%, 2.4% and 6.2% for adenomas with HGD and 2.9%, 4.0% and 3.6% for carcinomas, respectively. Overall PI were significantly higher in carcinomas than in adenomas with LGD, whereas AI were not different. Although the incidence of expression was significantly higher in carcinomas for p53 and in adenomas for Bcl-2 than the others, the expression of apoptosis-related gene products (p53, Bcl-2 and Bax) was similar among polypoid, flat elevated and depressed tumours. Macroscopic morphology of colorectal adenomas is determined by the apoptosis not by proliferation, and high apoptosis found in depressed adenomas implies their low net growth. Received: 1 July 1999 / Accepted: 17 January 2000     

Midkine expression in colorectal tumors: correlation with Ki-67 labeling in sporadic, but not ulcerative colitis-associated ones

Midkine (MK) is a heparin-binding growth factor encoded by a retinoic acid responsive gene. To investigate the possible contribution of MK to genesis of colorectal carcinomas, an immunohistochemical examination of protein expression was conducted in sporadic and ulcerative colitis (UC)-associated tumors. MK expression significantly differed among normal mucosa, adenomas with low-grade dysplasia (LGD), adenomas with high-grade dysplasia (HGD) and invasive adenocarcinomas: MK expression was increased along with tumor progression. UC-associated lesions (regenerative mucosa of UC, UC-associated dysplasia and UC-associated adenocarcinoma) had similar variations. MK expression in UC-associated lesions was significantly higher than in normal mucosa, although there was no significant difference among UC-associated lesions. However, in UC-associated dysplasia, MK expression did not differ between the upper and lower halves, in contrast to adenoma with LGD and HGD, in which MK expression was significantly higher in the upper than lower halves, corresponding to cell proliferative zone. Furthermore, correlations with Ki-67 and single-strand DNA labeling, respectively, reflecting cellular proliferative activity and apoptosis, were noted in sporadic but not UC-associated lesions. These results suggest that MK is involved in genesis/development of sporadic colorectal tumors as well as of UC-associated tumors, but might contribute differently to genesis/development in these two types of tumors.     

Low levels of apoptosis and proliferative activity in colorectal villous tumors: Comparison with tubular tumors

In order to clarlfy the cell kinetics of colorectal villous tumors (VT), 21 villous adenomatous areas and 12 carcinomatous areas within villous adenomas were investigated for proliferative activity and apoptosis and compared with a series of 41 tubular tumors (TT), demonstrating elements of intramucosal carcinomas as well as tubular adenomas (so-called carcinoma in tubular adenoma). Proliferation was estimated in terms of KI-67 labeling indices and mitotic indices, and apoptosis was assessed by DNA nick-end labeling to give apoptotic Indices. Apoptotic indices of villous adenomatous and carcinomatous regions were significantly lower than the values for their tubular counterparts. Kl-67 labeling indices were also significantly lower for adenoma components. Apoptotic indices, Ki-67 labeling indices and mitotic Indices increased with atypia raised in tubular adenoma components. Correlations of mitotic indices with apoptotic indices, Ki-67 labeling Indices with apoptotic indices and mitotic Indices with Ki-67 labeling indices were found for each villous tumor group and tubular tumor group, and the apoptosis and proliferation ratios for villous tumors were relatively low, suggesting a tendency for greater growth due to less cell deletion. Although this is only one of the biological features of villous tumor groups, it might play a major role in generation of malignancy.     

EXPRESSION OF BCL-2 PROTEIN IN HYPERPLASTIC POLYPS,ADENOMAS, AND CARCINOMAS OF THE COLON

The proto-oncogene Bcl-2 encodes a protein that protects cells from programmed cell death (apoptosis). The protein is expressed in the proliferative compartment of several normal tissues, including normal colonic crypts. The aim of this study was to test Bcl-2 expression in colorectal neoplasms, assuming that, as a regulator of apoptosis, it might be involved in the progression from adenoma to carcinoma. To this end, Bcl-2 reactivity was tested by immunohistochemistry in hyperplastic polyps, colonic adenomas, and carcinomas and its expression was compared with staining for the proliferation-associated Ki-67 antigen, using the MIB-1 antibody. Bcl-2 expression occurred in 2 out of 10 hyperplastic polyps and in 31 out of 35 (tubular, villous, and tubulovillous) adenomas, irrespective of their degree of dysplasia. Of ten carcinomas, only three were focally Bcl-2-positive, all moderately to well differentiated. In two of four carcinomas in Bcl-2-positive adenomas, no Bcl-2 staining was observed. High numbers of MIB-1-positive cells were found in all hyperplastic and neoplastic lesions, without apparent correlation between proliferation and Bcl-2 expression. These findings suggest that in the pathogenesis of hyperplastic polyps, increased crypt cell proliferation is primarily involved, but in some lesions decreased apoptosis may play a role. Furthermore, the increased Bcl-2 expression in adenomas but not in the majority of the carcinomas suggests either that decreased apoptosis is not usually involved in the pathogenesis of these lesions or that the regulation of apoptosis in colorectal epithelia involves additional regulatory factors.     

Expression of minichromosome maintenance 2 (MCM2), Ki-67, and cell-cycle-related molecules, and apoptosis in the normal-dysplasia-carcinoma sequence of the oral mucosa.

OBJECTIVE: We examined cell cycle and cell death biomarker trends with the normal-dysplasia-carcinoma sequence of the oral epithelia analyzing the pathological significance of a new biomarker, minichromosome maintenance 2 (MCM2). METHODS: This study analyzed 12 patients with normal oral epithelia, 69 with dysplasia, and 35 with squamous cell carcinoma (SCC); in 13 patients, SCCs were preceded by dysplasia. The sections were immunostained for MCM2, Ki-67, P53, P27(Kip1) and P21(CIP1/WAF1), and conducted by TUNEL methods. Western blot analysis of MCM2 was performed in the 4 human cultured oral SCCs, all of which showed the expression. RESULTS: Significantly higher labeling indices (LI; %) of MCM2, Ki-67, and P53, as well as lower LI of TUNEL indices (TI; %), P27, and P21 were noted in the SCCs than in the dysplasias. The 13 dysplasias developed SCC with significantly higher LI of MCM2 and P53, and lower LI of P21 than the other dysplasias (each p < 0.05). The LI of MCM2, P21 and the TI were not correlated with P53 expression. CONCLUSIONS: Oral dysplasia was characterized by lower cell proliferation and a higher frequency of cell death compared to SCCs. The higher LI of MCM2 and P53 and the lower LI of P21 might predict malignant transformation of oral dysplasia. MCM2 is regulated via a P53-independent pathway, and a useful biomarker of proliferating cells.     

Imbalance between proliferation and apoptosis in the development of colorectal carcinoma

 To evaluate the relationship between cell proliferation and apoptosis in sporadic colorectal carcinogenesis, immunohistochemistry for proliferation-associated antigen Ki-67 and in situ end labelling for identifying apoptotic bodies were performed on paraffin sections from 59 adenomas and 22 carcinomas. These results were correlated with the expression of the proliferation and apoptosis modulators Bcl-2 and p53. Carcinomas showed increased proliferation and apoptosis compared with adenomas (P<0.0001, P<0.001, respectively). There were positive linear correlations between proliferation and apoptosis in adenomas and carcinomas (P<0.02, P<0.05, respectively). The proliferative rate increased significantly from mild to moderate, and from moderate to severe dysplasia (P<0.002, P<0.001, respectively). Apoptotic rate also increased in this sequence, but the increases did not reach statistical significance (both P>0.05). Expression of Bcl-2 was associated with lower apoptotic rate in adenomas (P<0.025) but not in carcinomas (P>0.25), whereas p53 expression was correlated with higher proliferative rate in both adenomas and carcinomas (P<0.01, P<0.05, respectively). An inverse relationship between Bcl-2 and p53 expression was seen in both adenomas and carcinomas (P<0.05, P<0.005, respectively). These data suggest that the normal balance between proliferation and apoptosis is disturbed in colorectal carcinogenesis, both being increased, but proliferation occurs in excess. Bcl-2 and p53 may each play a role in modulating cell apoptosis or proliferation during the development of colorectal carcinoma. Received: 23 March 1998 / Accepted: 7 July 1998     

Proliferation and apoptosis in proliferative lesions of the colon and rectum

 Classically, neoplasia has been considered to be primarily a disturbance in the regulation of proliferation, but it is now clear that programmed cell death is dysregulated as well as proliferation. The genes that are implicated in the regulation of these processes, such as p53, c-myc and bcl-2, are often also altered in neoplasms. We have studied proliferation and programmed cell death in hyperplastic polyps, adenomas, carcinomas in adenomas and adenocarcinomas of the colorectum, using the MIB-1 antibody which recognizes the Ki-67 proliferation related antigen, and an in situ nick-end labelling procedure for histochemical labelling of proliferating and apoptotic cells. In addition, immunohistochemistry was used to study the expression of the p53, c-myc and bcl-2 proteins. The material studied consisted of 12 samples of normal mucosa, 8 hyperplastic polyps, 39 adenomas with different degrees of dysplasia and including 3 that carried a carcinoma, and 10 adenocarcinomas, all formalin fixed and paraffin embedded. The Ki-67 index indicated that proliferation increased progressively in hyperplasia, through different degrees of dysplasia in adenoma, to reach the highest level (Ki-67 index of 50%) in adenocarcinoma. Apoptosis also increased in hyperplastic polyps and in adenomas, but decreased significantly in adenocarcinomas. p53 Labelling was seen in 77% of the carcinomas but in only 3% of the adenomas. Expression of c-myc increased in adenomas and carcinomas. Furthermore, a shift from predominantly nuclear to predominantly cytoplasmic expression was seen in progressive neoplasms. Expression of bcl-2 was increased in an occasional hyperplastic polyp, but was increased markedly in almost all adenomas. Strikingly, in the adenomas with a carcinoma, the carcinoma showed weaker bcl-2 expression than the adenoma. In 20% of the carcinomas some bcl-2 staining was seen but this was less extensive than in the adenomas. Our findings indicate that in the progression from adenoma to carcinoma both increased proliferation and decreased apoptosis occur. This is paralleled by an increased expression of p53 and an increased and predominantly cytoplasmic expression of c-myc, but a decreased expression of bcl-2. This decreased bcl-2 expression does not lead to an increase in apoptotic activity. Received: 16 January 1997 / Accepted: 10 March 1997     

Correlation of p53 protein expression with apoptotic incidence in colorectal neoplasia

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.     

胃癌组织中c-FLIP及Ki-67表达的研究

目的 研究胃癌组织中c-FLIP及Ki-67的表达情况,并依此探讨胃癌细胞的凋亡与增殖之间的关系.方法 应用免疫组织化学的方法研究c-FLIP及Ki-67在100例胃癌标本中及100例胃良性疾病标本中的表达情况.结果 在胃癌组织中c-FLIP(χ2=35.17,P<0.01)及KI有较高表达(u=13.52,P<0.01);不同分化程度的胃癌标本中,c-FLIP表达差别有统计学意义(χ2=14.83,P<0.01),而KI差别无统计学意义(u=1.00,P>0.05).结论 在胃癌的发生与发展中,细胞凋亡受抑制与细胞增殖过度之间存在相互协同作用.     

Active matrix metalloproteinase-2 activity discriminates colonic mucosa, adenomas with and without high-grade dysplasia, and cancers

Pathologic assessment of colorectal adenomas, a complex task with significant interobserver variability, typically defines the scheduling of surveillance colonoscopies after removal of adenomas. We have characterized the activity levels of pro-matrix metalloproteinase-2, active matrix metalloproteinase-2, and matrix metalloproteinase-9 in colorectal adenomas and carcinomas as potential markers of pathologic progression during colorectal tumorigenesis. Endogenous fully activated matrix metalloproteinase-2, in particular, has been studied less frequently in adenomas due to difficulties in detection. For this report, tissues (n = 119) from 51 individuals were extracted and assayed on gelatin zymograms with digital standardization to nanogram quantities of purified active controls. Resulting data were assessed by graphical and multinomial logit regression analyses to test whether matrix metalloproteinase-2 or matrix metalloproteinase-9 activities could discriminate among 4 different types of colorectal tissue (normal mucosa, adenomas with or without high-grade dysplasia, and invasive carcinomas). Active matrix metalloproteinase-2 successfully discriminated among these tissue categories. Median activity for active matrix metalloproteinase-2 increased in a stepwise fashion with pathologic progression from normal mucosa to adenoma without high-grade dysplasia to adenoma with high-grade dysplasia to cancer. Although pro-matrix metalloproteinase-2 and pro-matrix metalloproteinase-9 activities could discriminate to some extent among tissue categories, those effects did not contribute additional information. Active matrix metalloproteinase-2 activity correlated significantly with histopathologic assessment of colorectal tissues. The ability of active matrix metalloproteinase-2 to distinguish adenomas with high-grade dysplasia from adenomas without high-grade dysplasia may be particularly useful in predicting future colorectal cancer risk for an individual, thus optimizing scheduling of surveillance colonoscopies.     

结直肠腺瘤及癌变组织中增殖基因和细胞凋亡调控基因的表达

目的 了解结直肠腺瘤癌变转化过程中细胞增殖与凋亡相关基因表达在癌变过程中的作用,并寻求判断腺瘤癌变的分子生物学指标。方法 采用免疫组织化学ＳＰ法检测６１份结直肠腺瘤癌变标本中ｐ５３、ｂｃ１－２、Ｆａｓ、ｂａｘ在腺瘤癌变区及腺瘤轻、重度异型增生区的表达;以Ｋｉ－６７指数和ＴＵＮＥＬ法计量细胞增殖率及凋亡率。结果 ６１份结直肠腺瘤癌变标本中ｐ５３蛋白在腺瘤癌变区、重度异型增生区及轻度异型增生区的表达分别为６７．２％、５７．４％和１９．７％;ｂｃ１－２蛋白的表达分别为７７．１％、８０．３％和４９．２％;腺瘤癌变区、重度异型增生区及轻度异型增生区的平均ｋｉ－６７指数分别为３８．４％、３６．５％和１６．１％;平均细胞凋亡指数分别为２．２％、１．９％及０．５％。ｐ５３蛋白、ｂｃ１－２蛋白的表达和Ｋｉ－６７指数、细胞凋亡指数     

Usefulness of endoscopic biopsy using immunostaining of p53 and Ki-67 in tumors of the ampulla of Vater

We investigated the diagnostic and prognostic value of p53 expression and proliferative activity, as indicated by the Ki-67, in endoscopic biopsy specimens. Specimens were immunologically stained with p53 and MIB-1 (Ki-67), and the MIB-1/Ki-67 labeling index (LI) was calculated. Classification of adenomas was based on findings of H&E-stained preparations into those with low- or high-grade atypia. Well-differentiated tubular and papillary adenocarcinomas were classified as carcinomas with low- or high-grade atypia. There were significant differences among the control and adenoma patients in MIB-1/Ki-67 LI (P < 0.05). No significant difference was identified between adenomas with high grade atypia and carcinomas with low grade atypia. The p53 expression was negative in all adenomas, but it was positive in 68.2% of carcinomas. The current study demonstrated that p53 protein expression in endoscopic biopsy specimens was of preoperative diagnostic value for carcinoma of the ampulla of Vater. The p53 protein positive tumors had a relatively higher malignant potential than p53 protein negative ones. The MIB-1/Ki-67 LI was useful in differentiating non-tumorous lesions from adenomas and adenomas with low- or high-grade atypia. The MIB-1/Ki-67 LI had a prognostic value because clinicopathological factors of carcinoma of ampulla of Vater correlated with MIB-1/Ki-67 LI.     

Bcl-2 expression and frequency of apoptosis correlate with morphogenesis of colorectal neoplasia

AIM: To investigate whether the expression of apoptosis and cell proliferation related proteins is related to the macroscopic form of colorectal neoplasia. METHODS: The extent of apoptosis, using the 3' end DNA labelling method, and the immunohistochemical expression of cell proliferation (Ki-67) and apoptosis related proteins (Bcl-2, Bak, and p53) were investigated in 64 colorectal adenomas and 22 early carcinomas extending no further than the upper submucosal region. The specimens were classified into three types of macroscopic form (polypoid, flat, and depressed). RESULTS: The Ki-67 labelling index and the Bak score did not differ significantly among each macroscopic form. In contrast, the apoptotic index and the Bcl-2 score changed significantly according to the macroscopic forms. Compared with polypoid and flat tumours, depressed tumours had a significantly lower apoptotic index (2.84, 2.28, and 1.44, respectively) and a significantly lower Bcl-2 score (3.18, 2.70, and 1.64, respectively). The proliferation/apoptosis ratio was significantly lower in polypoid tumours than in the other two macroscopic forms. The Bcl-2 score became significantly lower as the tumours flattened or took on a depressed form. Immunohistochemical p53 overexpression did not correlate with the macroscopic forms. CONCLUSIONS: These results suggest that differences in both Bcl-2 expression and apoptosis may play an important role in the morphogenesis of colorectal neoplasia.     

Immunohistochemical Analysis of the Cell Cycle-Associated Antigens Ki-67 and Retinoblastoma Protein in Parathyroid Carcinomas and Adenomas

The morphologic distinction between parathyroid carcinoma and adenoma can be a difficult diagnostic problem. We analyzed nuclear immunoreactivity for the cell cycle-associated antigen Ki-67 with monoclonal antibody (MAb) MIB-1 and for retinoblastoma (RB) protein with two polyclonal antisera in 24 parathyroid carcinomas and 35 adenomas, which were formalin fixed and paraffin embedded to determine if these antibodies could assist in distinguishing between carcinomas and adenomas. In addition, 10 cases of parathyroid hyperplasia and 5 cases of normal parathyroids were examined as control tissues. The Ki-67 labeling index was significantly higher in parathyroid carcinomas compared to adenomas (7.1 ± 1.0% vs 2.4 ± 0.2%,p<0.001). No patient with a parathyroid adenoma, parathyroid hyperplasia, or normal parathyroid gland had a Ki-67 labeling index >5.3%. Analysis of the primary tumors from patients with recurrent carcinomas and from those with nonrecurrent carcinomas showed a higher mean Ki-67 labeling index (7.8 ± 1.5% vs 5.2 ± 1.1%), in the former group, although these differences were not statistically significant. The RB protein immunoreactivity was not useful in distinguishing between parathyroid carcinomas and adenomas in paraffin-tissue sections. These results indicate that nuclear immunoreactivity for the cell cycle-associated antigen Ki-67 may be another useful method to assist in distinguishing parathyroid carcinomas from adenomas.     

Usefulness of proliferative activity, DNA ploidy pattern and p53 products as diagnostic adjuncts in colorectal adenomas and intramucosal carcinomas

Although numerous studies have assessed the biologic parameters of tumors, measurement of these parameters has had, to date, little impact on histologic diagnosis. Furthermore, analysis of a single parameter is insufficient to evaluate tumor malignant potential. In the present study, cell proliferation, DNA ploidy and p53 product were analyzed to objectify the tumor malignant potential in colorectal adenomas and intramucosal carcinomas. Sixty-one adenomas and 49 intramucosal carcinomas were studied using immunohistochemical analysis of Ki-67 and p53, silver-staining nucleolar organizer region (AgNOR) stain and DNA ploidy in fresh samples. Intramucosal carcinoma exhibited a greater Ki-67-positive rate and AgNOR count than the adenomas, although these parameters varied widely among samples. The incidence of aneuploidy and p53 over-expression in colorectal intramucosal carcinomas was significantly higher than in colorectal adenomas. These results indicate that DNA aneuploidy and p53 accumulation are the most reliable parameters for distinguishing benign and malignant lesions.     

Immunohistochemical characteristics of duodenal adenomas in familial adenomatous polyposis with special reference to cell kinetics

The duodenum is the second most frequent site of cancer in patients with familial adenomatous polyposis (FAP). The main objective of this study was to evaluate the cell kinetics in duodenal and ampullary adenomas in FAP. The endoscopic and biopsy findings of duodenal adenomas in 22 FAP subjects and 18 non-FAP subjects were compared. Adenomas in FAP included 15 ampullary adenomas and 17 nonampullary adenomas. The cell kinetics was evaluated by immunohistochemistry for Ki-67, p53, bcl-2, and cyclooxygenase 2 (COX2), and the apoptotic index (AI) as determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) method. Any correlations between the indices for cell kinetics and the endoscopic findings were identified. All 50 adenomas were histologically verified to be tubular adenoma with low-grade dysplasia. Neither the expression of Ki-67, p53, bcl-2, and COX2 nor the AI differed substantially between FAP and non-FAP subjects. In patients with FAP, duodenal adenoma tended to have a higher Ki-67-labeling index than the ampullary adenoma (54.3 +/- 11.3 versus 46.8 +/- 12.7; .05 < P < .1). In addition, the Ki-67-labeling index in endoscopically normal or slightly enlarged ampullary adenoma was significantly higher than that in markedly enlarged ampullary adenoma (51.8 +/- 11.4 versus 39.4 +/- 11.3; P < .05). Duodenal adenoma in FAP subjects was not found to have a higher proliferative activity or a smaller degree of apoptosis compared with those in non-FAP subjects. The smaller proliferative activity in larger ampullary adenoma may thus be related to the static nature of ampullary adenoma in FAP.     

Lack of Pseudomelanosis coli in colonic adenomas suggests different pathways of apoptotic bodies in normal and neoplastic colonic mucosa

Pseudomelanosis coli is characterized by pigment deposition in the lamina propria and caused by increased epithelial apoptosis. Pseudomelanosis coli is absent in colonic neoplasia. The aim of our studies was to investigate this phenomenon in more detail. Apoptotic fragments of epithelial cells and their distribution, cell proliferation (Ki-67, MIB 1 immunostaining), macrophages (CD68 immunostaining), Bcl-2 expression and apoptosis [terminal-deoxynucleotidyl-transferase mediated dUTP fluorescein nick end labeling (TUNEL) assay] were studied in adenomas arising in normal and melanotic colonic mucosa, in normal colonic mucosa and colonic mucosa with pseudomelanosis alone. In adenomas, we found 7.0 apoptotic bodies per 100 epithelial cells in the epithelial layer and only 0.2 apoptotic bodies per high power field (HPF) in the lamina propria. In contrast, in melanotic mucosa 1.7 apoptotic bodies per 100 epithelial cells in the epithelial layer and 2.5 per HPF in the lamina propria were found. Our results show that apoptotic fragments remain in the neoplastic (adenomatous) epithelium and do not reach (at least in higher amounts) the lamina propria. They can, therefore, not contribute to the development of pseudomelanosis in these lesions. However, macrophages are diminished in adenomas. Proliferation (Ki-67) and also Bcl-2 expression are highly increased in adenomas. The pathway of mucosal macrophages is also discussed. Received: 5 July 1999 / Accepted: 16 December 1999