Expression of the obesity hormone leptin and its receptor correlates with hypoxia-inducible factor-1 alpha in human colorectal cancer.

BACKGROUND: The obesity hormone, leptin, has been found to play a role in development and proliferation of normal and malignant tissues. Leptin activity is mediated through the leptin receptor (ObR) that is often expressed in different human cancer cells. Previously, we found that the expression of leptin and ObR can be stimulated by hypoxia-mimetic agents. The aim of this study was to analyze the abundance of and relationships among leptin, ObR and hypoxia-inducible factor-1alpha (HIF-1alpha, transcriptional regulator) in human colorectal cancer. MATERIALS AND METHODS: We investigated the expression of leptin, ObR and HIF-1alpha in colorectal cancer specimens from 135 patients who underwent curative resection. RESULTS: Immunoreactivity for leptin, ObR and HIF-1alpha protein was observed in 69 of 135 (51.1%), 129 of 135 (95.5%) and 88 of 135 (65.2%) of colorectal cancers, respectively. Statistically significant positive correlations were noted between leptin and HIF-1alpha (P = 0.005, r = 0.243), ObR and HIF-1alpha (P < 0.001, r = 0.325) as well as leptin and ObR (P < 0.001, r = 0.426) in the group of all patients as well as in various subgroups depending on clinicopathological features. CONCLUSIONS: The results indicate that the leptin system is overexpressed in human colorectal cancer and this overexpression appears to be associated with the abundance of HIF-1alpha.

Serum erythropoietin and angiogenetic factors in human colorectal cancer.

AIMS AND BACKGROUND: Erythropoietin, VEGF, VE-cadherin are involved in angiogenesis. Besides that erythropoietin stimulates erythropoiesis and increases haemoglobin and hematocrit levels as well. Moreover, erythropoietin could directly stimulate colorectal cancer cell growth due to the presence of both erythropoietin receptor and erythropoietin production in malignant cells of this neoplasm. Therefore we aimed at measurement and comparison of serum erythropoietin with VEGF, VE-cadherin levels, blood haemoglobin and hematocrit in colorectal cancer patients of different clinicopathological profiles. METHODS: We applied ELISA kits to evaluate preoperative serum levels of endogenous erythropoietin, VEGF and VE-cadherin in samples from 92 colorectal cancer patients and control group of 16 healthy volunteers. RESULTS: Endogenous erythropoietin was significantly elevated in preoperative sera in colorectal cancer patients (p = 0.013) compared with healthy volunteers, however, erythropoietin levels were not significantly higher with the advancement of colorectal cancer. There were significantly higher levels of erythropoietin in the group of anaemic men in comparison to men with normal haemoglobin levels (p < 0.0001). VEGF and VE-cadherin did not correlate with erythropoietin. Erythropoietin levels negatively correlated with haemoglobin and hematocrit levels in all cancer patients; particularly in node positive cancers (N+), moderately differentiated tumours (G2) and deeply invading neoplasms (pT3+pT4). CONCLUSIONS: Erythropoietin levels increase in colorectal cancer but circulating erythropoietin does not associate with progression of the disease. Thus, the use of recombinant erythropoietin seems to be safe. Our results suggest that negative feedback regulation persists between haemoglobin and erythropoietin in colorectal cancer. Production of erythropoietin remains therefore anaemia-associated, hypoxia-dependent and doesn't seem to be autonomic despite abundant expression of erythropoietin by colorectal cancers.

Increased expression of connexins 26 and 43 in lymph node metastases of breast cancer.

BACKGROUND: Gap junctions are intercellular channels composed of connexins, which mediate the direct passage of small molecules between neighbouring cells. They are involved in regulation of cell cycle, cell signalling, and differentiation, and probably invasion and metastasis. The role of connexins in the metastatic process is controversial, because some studies indicate that connexin expression is inversely correlated with metastatic capacity. In contrast, others demonstrate that connexins may be involved in metastasis. In addition, connexin status in breast cancer metastasis has not been widely studied. METHODS: We evaluated by immunohistochemistry the expression of connexin 26 (Cx26) and connexin 43 (Cx43) in primary breast tumours (PTs) and matched paired metastases to lymph nodes (MLNs). RESULTS: In PTs, we observed predominantly cytoplasmic localisation of evaluated connexins, indicating alterations in connexin expression in breast cancer cells. We demonstrated that expression of Cx26 and Cx43 was increased in MLNs compared with PTs (p<0.00001 and p<0.001, for CX26 and Cx43, respectively). In addition, Cx26 and Cx43 negative PTs developed Cx26 and Cx43 positive MLNs. Furthermore, besides increased cytoplasmic staining, enhanced membranous localisation of Cx43, typical of normal cells, was found in MLNs. Additionally, membranous Cx26 expression appeared only in metastatic breast cancer cells. CONCLUSIONS: These findings suggest that connexins may contribute to the efficient metastasising of breast cancer to the lymph nodes.

P53 correlates positively with VEGF in preoperative sera of colorectal cancer patients.

Diversity of P53 impact on tumor angiogenesis is due to the fact that wild-type P53 decreases expression of vascular endothelial growth factor (VEGF), but mutant P53 upregulates it. Therefore, we aimed at uncovering relations between preoperative serum levels of VEGF and P53 in colorectal cancer (CRC) patients. Preoperative blood samples of 125 CRC patients and 16 control healthy volunteers were examined with an ELISA-kit for serum P53 levels and VEGF. P53 did not correlate with VEGF in the whole group of CRC patients. However, P53 associated with VEGF in case of colorectal cancer patients, whose serum values of VEGF were higher than in controls (VEGF{H} >5.9333 pg/ml) (r=0.274, p<0.009). We revealed a positive correlation between P53 and VEGF{H} in subsets of poorly differentiated (G3) cancers (p<0.02), lymph node positive (p<0.007), pT3 or pT4 patients (p<0.004) without analogous relation in moderately differentiated (G2) tumors, node negative patients or pT1 or pT2 patients. P53 and IGF-I negatively correlated in all CRC patients (p<0.04) and VEGF{H} individuals of pT3 or pT4 (p<0.05) without any significant linkage in tumors of pT1 or pT2. The positive correlation between serum P53 and VEGF points at mutation of P53 and is a highly probable sign of poor prognosis in colorectal cancer. For now it can not be excluded that the binary analysis of serum P53 and VEGF could help select CRC patients endangered by rapid growth and lymph node metastases.

To give or not to give recombinant EPO to anemia endangered cancer patients.

EPO is known as an inducer of maturation and proliferation of erythrocytes. Moreover, it favours angiogenesis. In several studies it was encountered that EPO is a trophic agent that mediates survival and inhibits apoptosis of hypoxia affected cells, particularly those which build masses of irregularly vascularized cancers. The main task concerning EPO for oncologists is the choice to give or not to give recombinant EPO to anemia endangered cancer patients. EPO can do the quality of life better and cause recovery from anemia post chemotherapy and radiation of cancer patients. Nevertheless, EPO therapy shortens survival of patients in some cancers, in which antiapoptotic effect of EPO predominates directly in malignant cells. Thus, separately in every type of cancer, therapeutic use of recombinant EPO calls for prior investigations, if EPO signaling causes proliferation of cancer cells by direct stimulation of EPOR positive malignant cells. Unless the proliferative effect of EPO on cancer cells is excluded, its use in the therapy of anemia in cancer patients is not quite safe.

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 insulin receptor substrate 1 in primary breast cancer and lymph node metastases.

BACKGROUND: Insulin receptor substrate 1 (IRS-1) transmits signals from the insulin-like growth factor I receptor (IGF-IR) and insulin receptor (IR) and has been associated with the pathogenesis of cancer. IRS-1 downregulation has been suggested to play a role in breast cancer progression, but no simultaneous assessments of IRS-1 expression in primary breast cancer and metastases have been performed. AIMS: To assess IRS-1 expression in primary and metastatic breast cancer. METHODS: IRS-1 expression was analysed by means of immunohistochemistry in 109 samples of primary breast cancer and in 42 matched primary and metastatic tumours. In addition, IRS-1 expression was correlated with selected clinicopathological features, including oestrogen receptor alpha (ERalpha) and proliferation marker Ki-67 status. RESULTS: Positive cytoplasmic IRS-1 immunostaining was found in 69.7% (76 of 109) and 76.2% (32 of 42) of the primary and metastatic tumours, respectively. Both IRS-1 positive and IRS-1 negative primary tumours produced IRS-1 positive and IRS-1 negative metastases. IRS-1 expression in primary tumours correlated with poorly differentiated (G3) breast cancer (p < 0.005) and with lymph node involvement (p <0.05). In the subgroup of ERalpha positive primary tumours, IRS-1 expression positively correlated with Ki-67 (p < 0.02, r = 0.351), but in the subgroup of ERalpha negative primary tumours there was a negative correlation (p < 0.03, r = -0.509). IRS-1 expression in lymph node metastases correlated with neither ERalpha nor Ki-67. CONCLUSIONS: IRS-1 might be involved in breast cancer progression. Knowledge about differences between primary and metastatic tumours might help to understand mechanisms of breast cancer progression and lead to the development of more effective anticancer drugs.

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 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.

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.

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.

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.

Ultrastructural changes in the trabecular meshwork of congenital glaucoma.

Trabeculectomy specimens from 10 patients with congenital glaucoma were studied by electron microscopy. In all cases proliferation of fibrous connective tissue was found from the inner wall of Schlemm's canal. Accumulation of collagen fibres, sometimes of varied thickness and irregular striation, and agglomerations of microfibrillar material with the structure of collagen microfibrils were observed. This material formed basement membrane-like structures and 'shaggy' or fingerprint-like patterns. The ultrastructural examination of the trabecular meshwork revealed no significant differences between the morphological picture of primary congenital glaucoma and that found in Axenfeld and Rieger anomalies. Ultrastructural pictures of glaucoma cases examined in the present study converged also with those of juvenile glaucoma cases reported in literature, which may indicate the existence of a pathogenic factor common to these forms of glaucoma.

Bcl-2 expression in primary uveal melanoma.

AIMS: Uveal malignant melanoma is the most common intraocular tumor. The aim of this study was the analysis of bcl-2 oncoprotein expression in this tumor type. The melanomas were evaluated according to tumor location and patient age and sex. The relationship between bcl-2 expression and histological type, clinicopathologic stage and the presence of a set of predetermined morphological parameters was analyzed. METHODS: The study involved 39 patients with ocular melanomas treated with surgery alone between 1983 and 1997. Formalin-fixed, paraffin-embedded tissues were treated with anti-bcl-2 antibody (Dako No M0887). Immunolocalization of the bcl-2 oncoprotein was performed using the labeled streptavidin biotin (LSAB) method. bcl-2 expression in neoplastic cells was evaluated in a semiquantitative manner: lack of reactivity was defined as bcl-2 negative, reactivity present in less than 30% of cells as low bcl-2, and reactivity in more than 30% of cells as high bcl-2. The percentage of cells with a positive reaction was assessed independently by two pathologists, and the results were subjected to statistical analysis using Fischer's exact test. RESULTS AND CONCLUSION: No statistically significant correlation was found between the expression of bcl-2 oncoprotein and the clinicopathologic features analyzed. However, the high percentage of tumors with positive expression of this oncoprotein suggests that it plays a significant role in the biology of uveal melanoma.

Antioxidant status and lipid peroxidation in colorectal cancer.

Colon carcinogenesis is a multistep process where oxygen radicals were found to enhance carcinogenesis at all stages: initiation, promotion, and progression. Since insufficient capacity of protective antioxidant system can result in cancer, the aim of this study was to examine the activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and the levels of reduced glutathione, vitamin C, and vitamin E. The lipid peroxidation products were also determined by measuring malondialdehyde and 4-hydroxynonenal levels in colorectal cancer tissue collected from 55 patients. In these cases the activity of superoxide dismutase, glutathione peroxidase, and glutathione reductase was significantly increased while the activity of catalase was significantly decreased in cancer tissue. However, the level of nonenzymatic antioxidant parameters (glutathione, vitamin C, and vitamin E) was significantly decreased in cancer tissue. Further lipid peroxidation was enhanced during cancer development, manifested by a significant increase in malondialdehyde and 4-hydroxynonenal levels. The obtained results indicate significant changes in antioxidant capacity of colorectal cancer tissues, which lead to enhanced action of oxygen radicals, resulting in lipid peroxidation.

[Changes in intracellular protein degradation during the aging of an organism]. / Zmiany wewnatrzkomórkowej degradacji bialek w procesie starzenia sie organizmu.

This review describe the influence of free radicals on the protein degradation during aging. The consequences of aging are changes in susceptibility of proteins on the proteases action as well as changes in cell proteolytic systems activity in different organs.

Evaluation of p53 and bcl-2 oncoprotein expression in precancerous lesions of the oral cavity.

The oral cavity is continually exposed to various traumas due to the effect of thermal, mechanical and chemical stimuli, which when accompanied by inflammatory states may promote the growth of neoplastic changes. Numerous studies have revealed a correlation between the expression of p53 and Bcl-2 proteins and the progression of neoplastic disease. It cannot be excluded that these proteins act as biomarkers of a neoplastic transformation threatening in precancerous states (including leukoplakia) or the already existing neoplastic transformation (e.g. in oral squamous cell carcinoma). The aim of the study was to evaluate the expression of p53 and Bcl-2 proteins in the proliferating epithelium in relation to leukoplakia degree and with regard to the lesions accompanied and not accompanied by squamous cell carcinomas. Fifty-five cases of proliferating changes in the oral epithelium (leukoplakia) were investigated. Group I contained 20 leukoplakias not accompanied by oral squamous cell carcinomas. Groups II, III and IV included 35 cases of changes in the vicinity of carcinomas on the lower lip (group II), in the front 2/3 of the tongue (group III) and in the oral floor (group IV). Staining was performed according to the immunohistochemical method with the use of monoclonal antibodies against human p53 protein (DAKO No M7001) and Bcl-2 (DAKO No M0887). A higher expression of p53 protein (54%) was found in leukoplakia changes coexisting with squamous cell carcinomas, compared with the non-accompanied ones (p53--45%). The results indicate a correlation between epithelial dysplasia degree and p53 and Bcl-2 protein expression--severe dysplasia occurred with an increase in the expression of both proteins. Leukoplakias situated in the vicinity of squamous cell carcinomas showed higher expression of p53 and Bcl-2 compared with the non-accompanied alterations. A correlation was also revealed between the location and p53 and Bcl-2 protein expression degree in the non-accompanied changes; no such correlations were found in proliferating epithelial changes adjacent to neoplastic tumors.

Morphological and molecular aspects of cancerogenesis in the lung.

Morphology and some molecular aspects of hyperplastic (bronchial basal cell hyperplasia and alveolar cell hyperplasia), metaplastic (squamous metaplasia), preneoplastic and early neoplastic (dysplasia in squamous metaplasia, cancer in situ and atypical alveolar cell hyperplasia) changes were studied in 180 lungs resected due to non-small cell lung cancer: 106 cases (58.9%) of squamous cell carcinoma, 42 (23.3%) of adenocarcinoma and 32 (17.8%) of large cell carcinoma. P53 protein and PCNA expressions were detected immunohistochemically (using formalin-fixed, paraffin-embedded sections). DNA extracted from the microdissected P53-positive cells was analysed for point mutations in the P53 gene. No P53 immunostaining was observed in normal mucosa, hyperplasia of basal cells, squamous metaplasia without and with minor and moderate dysplasia of bronchial mucosa as well as alveolar cell hyperplasia. Overexpression of P53 protein occurred in 3 out of 12 (25%) cases of severe bronchial dysplasia, 5 out of 11 (45.5%) cases of intraepithelial carcinoma and 6 out of 45 (13.3%) cases of alveolar cell hyperplasia. Using direct sequencing, mutations in the P53 gene were detected in 11 out of 14 (87%) P53-immunopositive samples, including all severe dysplasias, all carcinomas in situ and 3 of 6 alveolar cell hyperplasias. A significant association was observed between PCNA expression and preinvasive as well as invasive lesions. The data clearly show that lung resected due to primary cancer ought to be treated as "field cancerization" in which one can find early morphologic events of multi-step cancerogenesis. P53 protein alterations and P53 gene mutations can occur before invasion and its frequency depends on the degree of dysplasia.

Immunohistochemical evaluation of cathepsin D expression in colorectal cancer.

Cathepsin D is one of the main proteolytic enzymes contributing to the development of cancer. The aim of the present study was to evaluate the expression of cathepsin D in 48 colorectal adenocarcinomas at pT3 stage of clinical advancement and G2 histologic grade. The correlation between cathepsin D expression, anatomo-clinical advancement and the presence of chosen anatomo-clinical properties of the tumours was also analysed. Formalin-fixed and paraffin-embedded tissues were investigated with anti-cathepsin D antibody. Immunolocalisation of cathepsin D was performed using Labelled Streptavidin Biotin (LSAB) method. A statistical correlation was found between high catepsin D expression in the cells of the main mass of the cancer and low cathepsin D expression in low-differentiated cancer cells which formed nests at the border of cancer invasion. There was no correlation between cathepsin D expression in the cells of colorectal cancer and other anatomo-clinical parameters of the tumours.