Proteolytic-antiproteolytic balance and its regulation in carcinogenesis

Cancer development is essentially a tissue remodeling process in which normal tissue is substituted with cancer tissue. A crucial role in this process is attributed to proteolytic degradation of the extracellular matrix (ECM). Degradation of ECM is initiated by proteases, secreted by different cell types, participating in tumor cell invasion and increased expression or activity of every known class of proteases (metallo-, serine-, aspartyl-, and cysteine) has been linked to malignancy and invasion of tumor cells. Proteolytic enzymes can act directly by degrading ECM or indirectly by activating other proteases, which then degrade the ECM. They act in a determined order, resulting from the order of their activation. When proteases exert their action on other proteases, the end result is a cascade leading to proteolysis. Presumable order of events in this complicated cascade is that aspartyl protease (cathepsin D) activates cysteine proteases (e.g., cathepsin B) that can activate pro-uPA. Then active uPA can convert plasminogen into plasmin. Cathepsin B as well as plasmin are capable of degrading several components of tumor stroma and may activate zymogens of matrix metalloproteinases, the main family of ECM degrading proteases. The activities of these proteases are regulated by a complex array of activators, inhibitors and cellular receptors. In physiological conditions the balance exists between proteases and their inhibitors. Proteolytic-antiproteolytic balance may be of major significance in the cancer development. One of the reasons for such a situation is enhanced generation of free radicals observed in many pathological states. Free radicals react with main cellular components like proteins and lipids and in this way modify proteolytic-antiproteolytic balance and enable penetration damaging cellular membrane. All these lead to enhancement of proteolysis and destruction of ECM proteins and in consequence to invasion and metastasis.

Lipid peroxidation and antioxidant status in colorectal cancer

AIM: Reactive oxygen species (ROS) can induce carcinogenesis via DNA injury. Both enzymatic and non-enzymatic parameters participate in cell protection against harmful influence of oxidative stress. The aim of the present study was to assess the levels of final lipid peroxidation products like malondialdehyde (MDA) and 4-hydroxy-2-nonenal (4-HNE) in primary colorectal cancer. Moreover, we analysed the activity of main antioxidative enzymes, superoxide dismutase (Cu, Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione reductase (GSSRG-R) and the level of non-enzymatic antioxidants (glutathione, vitamins C and E).

METHODS: Investigations were conducted in 81 primary colorectal cancers. As a control, the same amount of sample was collected from macroscopically unchanged colon regions of the most distant location to the cancer. Homogenisation of specimens provided 10% homogenates for our evaluations. Activity of antioxidant enzymes and level of glutathione were determined by spectrophotometry. HPLC revealed levels of vitamins C and E and served as a method to detect terminal products of lipid peroxidation in colorectal cancer.

RESULTS: Our studies demonstrated a statistically significant increase in the level of lipid peroxidation products (MDA-Adc.muc.-2.65±0.48 nmol/g, Adc.G3-2.15±0.44 nmol/g, clinical IV stage 4.04±0.47 nmol/g, P<0.001 and 4-HNE-Adc.muc. -0.44±0.07 nmol/g, Adc.G3-0.44±0.10 nmol/g, clinical IV stage 0.52±0.11 nmol/g, P<0.001) as well as increase of Cu,Zn-SOD (Adc.muc.-363±72 U/g, Adc.G3-318±48 U/g, clinical IV stage 421±58 U/g, P<0.001), GSH-Px (Adc.muc. -2143±623 U/g, Adc.G3-2005±591 U/g, clinical IV stage 2467±368 U/g, P<0.001) and GSSG-R (Adc.muc.-880±194 U/g, Adc.G3-795±228 U/g, clinical IV stage 951±243 U/g, P<0.001) in primary tumour comparison with normal colon (MDA-1.39±0.15 nmol/g, HNE-0.29±0.03 nmol/g, Cu, Zn-SOD-117±25 U/g, GSH-Px-1723±189 U/g, GSSG-R-625±112 U/g) especially in mucinous and G3-grade adenocarcinomas as well as clinical IV stage of colorectal cancer. We also observed a decrease of CAT activity (Adc.muc. -40±14 U/g, clinical IV stage 33±18 U/g vs 84±17 U/g, P<0.001) as well as a decreased level of reduced glutathione (clinical IV stage 150±48 nmol/g vs 167±15 nmol/g, P<0.05) and vitamins C and E (vit. C-clinical IV stage 325±92 nmol/g vs 513±64 nmol/g, P<0.001; vit. E-clinical IV stage 13.3±10.3 nmol/g vs 37.5±5.2 nmol/g).

CONCLUSION: Colorectal carcinogenesis is associated with serious oxidative stress and confirms that gradual advancement of oxidative-antioxidative disorders is followed by progression of colorectal cancer.

Expression of the Insulin Receptor Substrate 1 in primary tumors and lymph node metastases in breast cancer: correlations with Bcl-xL and Bax proteins

In our previous investigation Insulin Receptor Substrate 1 (IRS-1) correlated with proliferation marker Ki-67 in human breast cancer. The aim of the present study was to assess relationships between IRS-1 expression and anti-apoptotic Bcl-xL as well as proapoptotic Bax proteins, assessed by immunohistochemistry, in primary tumors and lymph node metastases of breast cancer. IRS-1 is positively associated with both Bcl-xL and Bax in primary and metastatic tumors. Thus, our results could suggest that IRS-1 might affect turnover of cancer cells and breast cancer progression through activation of mitogenesis and participation in the regulation of the balance between anti- and proapoptotic pathways.

Expression of Cell Proliferation and Apoptosis Markers in Papillomas and Cancers of Conjunctiva and Eyelid

Cell proliferation and programmed cell death are considered to be important events in carcinogenesis. The object of our study was to evaluate the expression of the Bcl-2 protein family (Bcl-2, Bak, Bax), p53, proliferating cell nuclear antigen (PCNA), and Ki-67 protein immunoexpression as well as the correlation between the examined markers and some clinicopathological features in papillomas and cancers of conjunctiva and eyelid. Forty-five squamous cell papillomas (SCP), 11 squamous cell cancers (SCC), and 27 basal cell cancers (BCC) were estimated. In the SCP group, p53 protein expression was observed in 30 cases (66.6%), Ki-67 in 14 (31.1%), PCNA in 44 (97.8%), Bcl-2 in 24 (53.3%), Bak in 28 (62.2%), Bax in 31 (68.9%), and Bcl-xl in 11 (100%). In the SCC group, p53 protein expression was evaluated in 8 cases (72.8%), Ki-67 in 2 (18.2%), PCNA in 8 (72.7%), Bcl-2 in 5 (45.4%), Bax and Bak both in 10 (90.9%), and Bcl-xl in 100%. In the BCC group, p53 protein expression was estimated in 23 cases (85.1%), Ki-67 in 13 (48.1%), PCNA in 26 (96.2%), Bcl-2 in 13 (48.1%), Bak in 21 (77.8%), Bax in 22 (81.5%), and Bcl-xl in 23 (85.2%). We observed a correlation between some clinicopathological features and the examined markers of apoptosis and cell proliferation, which seemed to be important events in cancer development.

Expression of the apoptotic markers in normal breast epithelium, benign mammary dysplasia and in breast cancer

Apoptosis and proliferation are processes associated with the development and progression of breast cancer. The sensitivity of tumour cells to the induction of apoptosis depends on the balance between pro- and anti-apoptotic proteins. The expression of Bak and Bcl-2 was examined using an immunohistochemical method in 71 primary breast cancers. Furthermore, Bcl-2 and Bak were assessed in the normal mammary gland as well as in benign mammary dysplasia adjacent to breast cancer. Positive immunostaining for Bcl-2 was observed in 77.8% of cases of normal breast epithelium (NBE), 93% of benign dysplasia without intraductal proliferation (BBD) as well as in 94% of intraductal proliferative lesions of the breast (BIPL). Expression of Bak was detected in 39% of cases of NBE, 45% of BBD and in 67% of BIPL. In breast cancer Bcl-2 and Bak expression was found in 83% and 70% of the cases studied, respectively. Increased Bcl-2 expression in primary tumours significantly correlated with favourable prognostic factors, namely pT1, G2 and lack of metastases to the regional lymph nodes (p < 0.01, p < 0.03, p < 0.02, respectively). There were no relationships between Bak and the clinicopathological features studied, but our results indicate changes in the expression of Bak during breast cancer development and progression. It would appear to be important to assess and compare pro- and anti-apoptotic proteins between normal mammary gland, benign mammary dysplasia and the primary tumours of breast cancer. This knowledge should be helpful in understanding breast cancer development and progression.

Expression of ERalpha, ERbeta and Ki-67 in primary tumors and lymph node metastases in breast cancer

The success of current hormonal therapies used in breast cancer patients often depends on estrogen receptor (ER) status. The simultaneous pathological assessment of primary breast tumors (PTs) and metastases to regional lymph nodes (MRLNs) could improve the effectiveness of this treatment, but is rarely performed. Consequently, we studied by immunohistochemistry the expression of ERalpha (ERalpha), ERbeta (ERbeta), and the proliferation marker (Ki-67) in PTs and matching MRLNs. The expression of each ERalpha, ERbeta, and Ki-67 positively correlated between PTs and MRLNs (r=0.751, p<0.0001; r=0.391, p<0.03; and r=0.707, p<0.0001, respectively). A negative correlation between the expression of ERalpha and Ki-67 was found in PTs (r=-0.678, p<0.001) and MRLNs (r=-0.501, p<0.005). A negative correlation between ERalpha and Ki-67 was also observed in PTs vs. MRLNs (r=-0.619, p<0.0001). Moreover, the expression of ERalpha and Ki-67 was not associated with nodal status, contrary to ERbeta expression, which correlated with negative axillary node status. The results indicated that the associations among ERalpha, ERbeta, and Ki-67 are maintained in PTs and MRLNs. Thus, simultaneous assessment of selected markers in PT and MRLN might help in understanding the mechanisms of breast cancer progression as well as result in the development of new principles for diagnosis and individual therapy planning of estrogen dependent cancer.

An evaluation of Ki-67 and PCNA expression in conjunctival and eyelid tumours

The aim of our study was an evaluation of the expression of cell proliferation markers (PCNA and Ki-67) in conjunctival and eyelid papillomas and squamous and basal cell cancers. A series of 9 cases of squamous cell cancer (SCC), 15 cases of basal cell cancer (BCC) and 43 cases of squamous cell papilloma (SCP) were assessed using the immunohistochemical method with monoclonal antibodies. PCNA overexpression was observed in 100% of SCP, in 88.8% of SCC and in 100% of BCC cases. Ki-67 overexpression was seen in 32.5% of cases of SCP, in 22.2% of SCC and in 66.6% of BCC. The results showed that an evaluation of Ki-67 expression is the most valuable cell proliferation marker.

The presence of sex hormone receptors in the vesicouterine fistula

Although the traditional management of vesicouterine fistula is surgical, a recent review of world data showed high efficacy of hormonal manipulation by the induction of amenorrhea. The prerequisite for the action of sex hormones is the presence of target receptors in the given tissue. The current study examined the histology of the vesicouterine fistula in order to identify the possible cellular components containing sex hormone receptors. The presence of an epithelium similar to endometrium containing sex hormone receptors was demonstrated immunohistochemically and by hematoxylin-eosin staining, a finding in agreement with the definition of endometriosis. Our paper provides an explanation for the high efficacy of hormonal manipulation in the treatment of this relatively rare type of fistula.

Insulin-like growth factor-I receptor in human oral cancer

The purpose of the study was to evaluate the expression of IGF-IR in primary tumours and lymph node metastases of oral cancers and the correlation between expression of IGF-IR and some clinicopathological features. Fifty-seven (57) oral cancers were examined by immunohistochemical studies, using the avidin-biotin-peroxidase method. Our study included only oral cancers, classified histopathologically as squamous cell carcinoma (7 cases in G1 grade, 44 (G2) and 6 (G3); 23/pT1 stage, 18/pT2, 7/pT3 and 9/pT4). Positive immunostaining for IGF-IR was noted in 32, out of 57 (56.1%) of oral tumours. We found a tendency (p=0.081) toward an association between IGF-IR expression in the primary tumours and their stage (pT3 and pT4). A comparison between the primary tumours and matching lymph node metastases revealed that 13, out of 20, (65%) cases showed a convergence between primary tumours and matching lymph node metastases with regard to either negative or positive staining.

Expression of connexins 26, 32 and 43 in the human colon--an immunohistochemical study

Gap junctional intercellular communication (GJIC) is a mechanism for direct cell-to-cell signalling and is mediated by gap junctions (GJs), which consist of proteins called connexins (Cxs). GJIC plays a critical role in tissue development and differentiation and is important in maintenance of tissue homeostasis. The purpose of the study was to evaluate the expression of Cx26, Cx32 and Cx43 in the human colon. Surgical specimens were obtained from patients who underwent surgical resection of colorectal tumours. Tissue samples (50 cases) were collected from normal colon, at the maximum distance from the tumor. Using antibodies for Cx26, Cx32 and Cx43, immunohistochemical detection was made. In epithelial cells, strong Cx26 immunoreactivity was found, whereas Cx32 and Cx43 were sparsely distributed. Strong Cx43 immunostaining in muscularis mucosae was observed. In the circular layer of muscularis externa, expression of Cx43 and Cx26 was seen, but only in the portion closest to the submucosa. No immunoreactivity was found in the longitudinal muscle layer. Small vessels stained positively only for Cx43. Furthermore, there was no difference in staining between samples derived from various sections of the colon. This study showed immunohistochemically for the first time the expression of Cx26 in human colon mucosa.

Expression of the insulin-like growth factor-I receptor in primary breast cancer and lymph node metastases: correlations with estrogen receptors alpha and beta

Numerous laboratory studies and some epidemiological data have suggested the involvement of the insulin-like growth factor-I receptor (IGF-IR) in breast cancer development and progression. However, data on IGF-IR expression in human tissues, including breast cancer sections, are limited and often inconsistent. We therefore examined by immunohistochemistry the expression of IGF-IR in primary tumors and breast cancer metastases to lymph nodes, and correlated IGF-IR positivity with estrogen receptor (ER) status and selected clinicopathological features. We found that 1) IGF-IR was expressed in primary tumors as well as in lymph node metastases, but the expression in primary tumors was more frequent (56 % vs. 44.4 %); 2) IGF-IR expression in primary tumors was associated with negative node status (p < 0.033); 3) in node-negative primary tumors, IGF-IR positively correlated with ERbeta (p < 0.008; r = 0.538), but not with ERalpha, tumor size or grade; 4) both IGF-IR-positive and IGF-IR-negative primary tumors were found to produce IGF-IR-positive as well as IGF-IR-negative metastases; 5) in metastases, IGF-IR expression did not associate with ERalpha, ERbeta or any of the studied pathobiological markers. The results suggest that IGF-IR could become a viable pharmaceutical target in breast cancer therapy, but such therapy should be based on IGF-IR assessment in primary tumor and metastasis in each potential patient.

Expression of connexin 43 in breast cancer in comparison with mammary dysplasia and the normal mammary gland

Gap junctional intercellular communication (GJIC) plays a critical role in tissue development and differentiation and probably in carcinogenesis. The purpose of the study was to evaluate the expression and localisation of Cx43 in 40 cases of mammary dysplasia and 29 cases of breast cancer (without primary chemotherapy). The tissue sections were investigated for Cx43 expression by immunohistochemistry. In the normal mammary gland there was an intercellular, punctate staining pattern, mainly between myoepithelial cells, characteristic of functional gap junctions. In dysplasias there was mainly mixed (cytoplasmic and intercellular) staining and in most cases of breast cancer we observed diffuse or granular, but cytoplasmic, staining of Cx43. Our results demonstrated that expression of Cx43 in dysplasias and breast cancer is changed and GJIC is probably impaired because of disruption of functional gap junction formation especially between breast cancer cells.

[Comparative studies of K1-67 expression between the primary tumor and breast cancer metastases to regional lymph nodes]

Breast cancer is often relatively slow growing, but at diagnosis about 40% of patients have regional spread to at least one axillary node. It has been shown that unrelated clones are in primary breast carcinomas. There is possibility that only a small subpopulation of the cells of the primary tumour (PT) metastasis. It has been shown that Ki-67 protein is a useful marker in histopathology, which is present during all active phases of the cell cycle and making possibility to assess growth fraction of tumour cells. The purpose of the study was to evaluate the expression of Ki-67 and comparison between the PTs and MRLNs as well as to estimate the relationships between Ki-67 and the chosen anatomoclinical features of the breast cancer. Immunohistochemical analyses for Ki-67 were performed on the PTs (69 cases without primary chemotherapy) and MRLNs (33 cases) of breast cancer. Increased expression of Ki-67 in PTs significantly correlated with pT2 stage of tumours (p < 0.05) and grade G3 (p < 0.04), but there was not relationship with lymph node status. Expression of Ki-67 positively correlated between PTs and MRLNs (p < 0.001). Comparison between PTs and matching MRLNs revealed that 23 (69.7%) cases showed a convergence between PTs and matching MRLNs with regard to negative or positive staining. We would like to emphasize the importance of studies concerning the proteins involved in proliferation in MRLNs, because knowledge about heterogeneity between PTs and MRLNs could shed light on tumour biology and may lead to development of more effective anti-cancer therapies.

Correlation between Bcl-2 protein expression and some clinicopathological features of oral squamous cell carcinoma

Bcl-2 inhibits most kinds of programmed cell death and provides a selective survival advantage to various cell types. The biological significance of Bcl-2 expression for the development and progression of oral cancer has still to be evaluated. The aim of our study was to estimate possible correlations between the Bcl-2 protein expression and some clinicopathological features of oral cancer. The study was conduced on 129 patients treated surgically for oral squamous cell carcinoma. The statistically significant relationships were observed between oral squamous cell cancer Bcl-2 expression and higher tumor grading (p<0.005), higher tumor mitotic index (p<0.005), higher index of atypical mitoses (p<0.001) as well as microfocal pattern of tumor invasive margin (p<0.001). The results suggest that positive Bcl-2 expression may be a valuable factor supplementing the established unfavorable histopathological features of oral squamous cell carcinoma.

The expression of tumorigenesis markers in oral papilloma

Oral papilloma is the most frequent benign tumor of the oral cavity but its biological potential for malignant transformation is still to be evaluated. The alteration of apoptosis and uncontrolled cell proliferation is considered to be an important factor in oral tumorigenesis. The aim of our study was to evaluate by immunohistochemistry P53, Bcl-2, CD44 and PCNA expression in oral papillomas with and without dysplasia. We examined a series of 55 oral papillomas, including 12(21.8%) cases of papillomas with epithelial dysplasia. Staining patterns were correlated with sex, age, tumor location, size and presence or absence of epithelial dysplasia. P53 showed positive reaction in 70.9%, PCNA in 80%, CD44 in 50.9% and Bcl-2 in 21.8% of papillomas. There was no correlation between sex, age, tumor size, location and presence of dysplastic epithelium in papillomas. We observed a statistically significant correlation between Bcl-2, CD44 expression and presence of epithelial dysplasia in papillomas. Coexistence of PCNA and P53 positive immunostaining was observed. Papillomas with overexpression of P53 and PCNA showed negative reaction for CD44 protein. The results of our study suggest that overexpression of P53 and PCNA might be an early event in oral tumorigenesis, whereas CD44 and Bcl-2 are potential markers of epithelial dysplasia in oral papillomas.

Correlation between colorectal cancer Bcl-2 expression and tumour clinicopathological variables

The aim of our study was to elucidate whether and in a what way applying two slightly different immunohistochemical procedures effects Bcl-2 protein detection as well as its relationship to colorectal cancer clinicopathological features. A series of 74 primary colorectal cancers was investigated for expression of the Bcl-2 protein. Two immunohistochemical procedures: first with antigen retrieval using a microwave (art-), second with antigen retrieval by use pressure pot (art+) pre-treatment, were applied in each cancer case. Formalin-fixed, paraffin embedded tissues were treated with ant-Bcl-2 antibody (Dako No M 0887). Bcl-2 (art+) immunostaining was positive in 48 (64.9%) cases of colorectal cancers whereas Bcl-2 (art-) immunohistochemical reaction was positive only in 15 (20%) colorectal tumours. A significant, positive correlation was observed between Bcl-2 (art+) expression and localization of the tumour in the rectum (p = 0.007). At the same time a statistically significant positive correlation between tumour Bcl-2 (art-) expression and colon tumour pT stage (p = 0.007), rectum tumour differentiation grade (p = 0.04) and Bcl-2 (art-) protein immunostaining in lymph node metastases (p < 0.000001) was observed. This data suggest that the type of procedure for antigen retrieval to detection of Bcl-2 protein by immunohistochemical reaction, changes the study results and should be considered when comparing own results with the literature data.

Prognostic significance of CD34 expression in early cervical squamous cell carcinoma

The aim of the study was to evaluate angiogenesis as an independent prognostic factor and to determine the correlation of the microvessel density (MD) with lymph node metastases and survival rate in 73 women operated because of invasive squamous cell carcinoma (SCC) of the uterine cervix at clinical stages lb and IIa (FIGO). The patients were divided into two groups: I--25 (34.4%) with survival rate <5 years and II--48 (65.6%) with survival rate >5 years. Angiogenesis was quantified in light microscope using an assay for CD34. The CD34 antibody intensely immunostained single endothelial cells as well as larger microvessels. In the study. differences were revealed by comparing the MD between both groups. The 5-year overall survival rate for patients with high MD was significantly worse than for those with low MD (p<0.003). A correlation was found between angiogenesis intensity and vascular involvement as well as the incidence of lymph node metastases. Thus, tissue expression of CD34 in SCC appears to be a significant prognostic indicator.

P53 protein expression in oral squamous cell cancer in relation to some of its clinicopathological variables

Oral squamous cell cancer develops through a multistep process by the accumulation of genetic and phenotypic changes. Loss of P53 tumor suppressor gene function represents the most common genetic lesion in human cancer. The significance of P53 expression for the development and progression of oral squamous cell cancer has still to be evaluated. The aim of this study was to estimate relationships between P53 protein expression and some clinicopathological variables of established or presumed prognostic value. A series of 129 oral squamous cell cancers was investgated retrospectively for expression of P53 protein by immunohistochemistry of paraffin-embedded tissue sections. The slides were stained with H+E and by immunohistochemistry with anti-human P53 antibody. Positive immunohistochemical staining for P53 protein was present in 75 (58%) oral cancer cases. There were no statistically significant correlations between oral cancer P53 expression and tumor site, grading, mitotic index, invasive margin type, as well as patients age and sex. Our results suggest that immunohistochemical overexpression of P53 is an important markerof accomplished neoplastic transformation in oral cavity lesions but it does not play a crucial role in the tumor progression.

Antioxidant potential in esophageal, stomach and colorectal cancers

BACKGROUND/AIMS

The gastrointestinal tract is particularly susceptible to reactive oxygen species attack which lead to carcinogenesis. An important role in defense strategy against reactive oxygen species is played by antioxidants. The present study aims at examining antioxidant parameters and malondialdehyde--the product of lipid peroxidation as well as the marker of cancer progression--and cancer procoagulant in esophageal, gastric and colorectal cancer patients.

METHODOLOGY

The activity of superoxide dismutase, catalase, glutathione peroxidase and reductase and the level of glutathione, vitamin C, malondialdehyde and cancer procoagulant were determined in tumors and normal mucous from 18 patients with esophageal cancer, 18 patients with stomach tumor and 62 patients with colorectal cancer.

RESULTS

In esophageal tumor the activity of all enzymes has been increased compared with normal mucous. Stomach tumor has been also characterized by an increase in antioxidant enzymes activity except glutathione peroxidase and reductase whose activities have been decreased. However in colorectal tumor the activity of enzymes has been increased apart from catalase. In all cases the glutathione level has been increased while the vitamin C content has been significantly decreased. Tumor malondialdehyde level was significantly increased, too. The level of cancer procoagulant also increased in cancer tissues as well as in the serum.

CONCLUSIONS

Antioxidant potential in all cases of gastrointestinal tract cancer has been unbalanced which has lead to increase in reactive oxygen species action and enhancement of lipid peroxidation and cancer procoagulant generation.

Tumour 'budding' and its relationship to p53 and Bcl-2 expression in colorectal cancer

The formation of poorly-differentiated clusters of cancer cells in the tumour growth zone, defined as "tumour budding", is a likely factor determining the biological malignancy of colorectal cancer (CRC). The aim of the study was to evaluate tumour budding in the CRC growth zone and to analyse its relationship to chosen anatomoclinical parameters, and to p53 and Bcl-2 protein expression in the tumour budding and in the main tumour mass. Fifty-seven colorectal cancers, classified as pT3 and G2, were used for analysis. Immunohistochemical investigations were performed using the anti-human p53 and Bcl-2 protein monoclonal antibodies (Dako/p53, No M7001 and Dako/Bcl-2, No M 0887, respectively). It has been found that p53 overexpression in the primary tumour and the presence of lymph node metastases correlate with strongly-positive tumour budding (p < 0.04 and p < 0.000001). However, low expression of p53 protein in the primary tumour and lack of lymph node metastases was statistically significantly correlated with the absence of tumour budding. A statistically significant correlation was shown between p53 protein expression in the tumour budding and expression of p53 in the primary tumour and lymph node metastases (p < 0.05). We also observed a statistically significant correlation between Bcl-2 protein expression in the tumour budding and its expression in the primary tumour and lymph node metastases (p < 0.05). These data suggest that tumour budding of cancer, in combination with other markers, may provide more information about the biological behaviour of colorectal cancer.

Suitability of selected markers for identification of elements of the Intestinal Nervous System (INS)

The possibility of identifying and characterising elements of the enteric nervous system based on their contents of cathepsin D, chromogranin A, neuronal specific enolase and S-100 protein was studied in colorectal specimens (operative full-thickness, seromuscular and mucosomuscular biopsies) obtained from 15 children, aged 2 days to 10 years. Nine patients suffered from Hirschsprung's disease, and two from chronic constipation. Four neonates with imperforate anus or meconium ileus composed the control group. All markers were identified immunohistochemically by antibodies against human antigens with appropriate detection methods. Chromogranin A staining was not always adequate to identify all neuronal cell bodies and other nervous elements. However, it proved superior to the other methods in the depiction of neuroendocrine cells in the intestinal mucosa. Cathepsin D antibodies stained normal and abnormal neural cells with different intensity; nerve fibres were not stained. This marker did not allow an unequivocal differentiation of ganglion cells from macrophages within the submucosa; the latter exhibited exceptionally strong marking and in some cases represented the predominant elements in this area. Neuronal specific enolase was distinctly expressed in nerve cells and fibres of the intestinal wall. Atrophic and hypoplastic features could be identified, suggesting that this method may give some insight into functional aspects. Continuous connections between ganglions were also observed. S-100 protein antibodies resulted in a negative image of unstained ganglion cells surrounded by extensively marked Schwann cells and neural fibres. With respect to clinical application, all these markers may provide supplementary information for the differential diagnosis of intestinal motility disorders.

Effect of the cytokine rhTNF-alpha on the population of mast cells in the growth of MethA fibrosarcoma--a TEM study

The aim of the present study was the ultrastructural characteristics of mast cell (MC) involved in host antitumor responses induced by local (i.t.) administration of recombinant human tumor necrosis factor alpha (rhTNF-alpha) in the primary focus of methA fibrosarcoma. MC were involved in tumor interstitium remodeling. Numerous mitochondria, well-developed RER and Golgi apparatus, clusters of polyribosomes, considerable polymorphism of granules and differentiated lamellar structures which frequently presented myelinic forms were observed after rhTNF-alpha application. In the study numerous fibres of the fibrous tissue, richly vascularized, occurred in the peripheral and intermediate tumor zones. Cluster of MC and tumor cells were seen on the border of the necrotic foci. However, proteolytic enzymes released by MC cause interstitial lysis, ensuring the place for tumor growth, and are involved in angiogenesis. Thus, it is not clear whether MC contribute to the inhibition of tumor growth or have an adjunctive role in tumor progression.

PCNA and P53 expression in relation to clinicopathological features of oral papilloma

Although papilloma is the most frequent benign epithelial tumour of oral cavity, its biological potential for malignant transformation is still to be evaluated. The aim of the study was to correlate PCNA and P53 expression in 55 oral papillomas with some clinicopathological variables. The tissue samples were stained with H+E and by immunohistochemistry for PCNA and P53 protein. Staining patterns were assessed semiquantitatively and correlated with each other and grade of tumour epithelial dysplasia, tumour size, localization well patient age and sex. PCNA immunostaining was positive 43 (78%) oral papillomas. P53 immunohistochemical reaction was positive in 38 (69%) out of 55 epithelial tumours. Positive relationship between PCNA and P53 expression was observed as well as between PCNA immunostaining and grade of epithelial dysplasia. There was no statistically significant relationships between PCNA, P53 immunohistochemical positivity and papilloma size, site, patient age and sex. The results of this study suggest that immunohistochemical P53 overexpression is valuable marker of early neoplastic transformation and together with PCNA are presumed predictors for malignant transformation of oral papillomas.

Tissue expression of VEGF as a prognostic factor in early cervical squamous cell carcinoma

The purpose of this retrospective study was to determine whether the intensity of tumor angiogenesis, expressed as microvessel density (MD), is indeed an important parameter predicting lymph node metastasis and survival rate in 73 women operated on for early invasive squamous cell carcinoma of the uterine cervix in stages Ib and IIa (FIGO). Angiogenesis was quantified by light microscope (LM) using an assay for vascular endothelial growth factor (VEGF). In the study, differences were revealed by comparing the MD between both groups. The patient survival with high MD was significantly worse than for those with low MD (p<0.01). A correlation was found between MD and the incidence of lymph node metastases. Hence, quantitative analysis of MD used as the expression of VEGF in the each cervical squamous cell carcinomas could be useful as a significant prognostic indicator.