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.

Levels of Ve-Cadherin Increase Independently of Vegf in Preoperative Sera of Patients with Colorectal Cancer

AIMS AND BACKGROUND

Vascular endothelial cadherin (VE-cadherin) preserves the tightness of the mature vascular network as a component of endothelial adherens junctions. Vascular endothelial growth factor (VEGF) makes VE-cadherin dissociate from complexes with beta-catenin, so that endothelial cells can loosely proliferate and migrate. We searched for relationships between VEGF and VE-cadherin levels in preoperative sera of patients with colorectal cancer (CRC). We also compared VE-cadherin levels of control and preoperative CRC sera in relation to clinicopathological features.

METHODS

We measured with an ELISA kit the serum levels of the proteins in preoperative samples from 125 CRC patients and in samples from 16 healthy volunteers.

RESULTS

Serum VE-cadherin was about fourfold higher in CRC patients than in controls (P < 0.00001), with similar results being found in subgroups with different clinicopathological features versus controls. VE-cadherin was not correlated with VEGF in the entire group of CRC patients nor in the subgroups of node-positive and node-negative patients, different grades of histological differentiation (G2 or G3), extent of tumor growth (pT1+pT2 or pT3+pT4), histopathological type (adenocarcinoma or mucinous carcinoma), sex, age, and tumor site (colon or rectum). However, the serum levels of VE-cadherin and VEGF in CRC patients, which were higher than the mean values of controls, tended towards a negative correlation in node-positive patients (P = 0.078, r = -0.279).

CONCLUSIONS

VEGF and VE-cadherin seem to be independent markers of angiogenesis in CRC with no significant correlation between their serum levels.

Relationships between hypoxia markers and the leptin system, estrogen receptors in human primary and metastatic breast cancer: effects of preoperative chemotherapy

BACKGROUND

Tumor hypoxia is marked by enhanced expression of hypoxia-inducible factor-alpha (HIF-1alpha) and glucose transporter-1 (Glut-1). Hypoxic conditions have also been associated with overexpression of angiogenic factors, such as leptin. The aim of our study was to analyze the relationships between hypoxia markers HIF-1alpha, Glut-1, leptin, leptin receptor (ObR) and other breast cancer biomarkers in primary and metastatic breast cancer in patients treated or untreated with preoperative chemotherapy.

METHODS

The expression of different biomarkers was examined by immunohistochemistry in 116 primary breast cancers and 65 lymph node metastases. Forty five of these samples were obtained form patients who received preoperative chemotherapy and 71 from untreated patients.

RESULTS

In primary tumors without preoperative chemotherapy, HIF-1alpha and Glut-1 were positively correlated (p = 0.02, r = 0.437). HIF-1alpha in primary and metastatic tumors without preoperative therapy positively correlated with leptin (p < 0.0001, r = 0.532; p = 0.013, r = 0.533, respectively) and ObR (p = 0.002, r = 0.319; p = 0.083, r = 0.387, respectively). Hypoxia markers HIF-1alpha and Glut-1 were negatively associated with estrogen receptor alpha (ERalpha) and positively correlated with estrogen receptor beta (ERbeta). In this group of tumors, a positive correlation between Glut-1 and proliferation marker Ki-67 (p = 0.017, r = 0.433) was noted. The associations between HIF-1alpha and Glut-1, HIF-1alpha and leptin, HIF-1alpha and ERalpha as well as Glut-1 and ERbeta were lost following preoperative chemotherapy.

CONCLUSIONS

Intratumoral hypoxia in breast cancer is marked by coordinated expression of such markers as HIF-1alpha, Glut-1, leptin and ObR. The relationships among these proteins can be altered by preoperative chemotherapy.

Gradual loss of functional gap junction within progression of colorectal cancer -- a shift from membranous CX32 and CX43 expression to cytoplasmic pattern during colorectal carcinogenesis

The aim of this study was the assessment of expression and location of CX32 and CX43 in colorectal adenomas and carcinomas as well as analysis of expression of these proteins in association with clinical and pathological features of tumors and evaluation of mutual relationships between CX32 and CX43.

PATIENTS AND METHODS

The study included 151 primary colorectal carcinoma and 71 colorectal adenomas. The control group comprised 30 colon samples. Connexins were detected with immunohistochemistry.

RESULTS

There was a lack of membranous distribution of connexins or a shift from moderately membranous immunoreactivity to predominantly cytoplasmic accumulation of CX32 and CX43 in studied colon tumors. Mentioned alterations were found in adenomas and augmented in cancer. Expression of Cx32 was significantly associated with grading of colorectal cancer, implicating a role of intracellular CX32 in regulation of tumor growth and differentiation. A strong correlation was present between CX32 and CX43 in node-positive cases and absent from node-negative ones.

CONCLUSION

To our knowledge, our study is the first illustration for a gradual loss of functional gap junctions within progression of colorectal neoplasia. An intracellular location of connexins, the site of their common and the most frequent detection within cancer cells in our study may be of significance. Independently of its role in functional gap-junctions, cytoplasmic CX32 could be involved in cancer differentiation, resulting in a higher rate of CX32 positive moderately differentiated tumors (G3) than poorly differentiated CX32-positive ones (G3).

Gradual loss of functional gap junction within progression of colorectal cancer -- a shift from membranous CX32 and CX43 expression to cytoplasmic pattern during colorectal carcinogenesis

The aim of this study was the assessment of expression and location of CX32 and CX43 in colorectal adenomas and carcinomas as well as analysis of expression of these proteins in association with clinical and pathological features of tumors and evaluation of mutual relationships between CX32 and CX43.

PATIENTS AND METHODS

The study included 151 primary colorectal carcinoma and 71 colorectal adenomas. The control group comprised 30 colon samples. Connexins were detected with immunohistochemistry.

RESULTS

There was a lack of membranous distribution of connexins or a shift from moderately membranous immunoreactivity to predominantly cytoplasmic accumulation of CX32 and CX43 in studied colon tumors. Mentioned alterations were found in adenomas and augmented in cancer. Expression of Cx32 was significantly associated with grading of colorectal cancer, implicating a role of intracellular CX32 in regulation of tumor growth and differentiation. A strong correlation was present between CX32 and CX43 in node-positive cases and absent from node-negative ones.

CONCLUSION

To our knowledge, our study is the first illustration for a gradual loss of functional gap junctions within progression of colorectal neoplasia. An intracellular location of connexins, the site of their common and the most frequent detection within cancer cells in our study may be of significance. Independently of its role in functional gap-junctions, cytoplasmic CX32 could be involved in cancer differentiation, resulting in a higher rate of CX32 positive moderately differentiated tumors (G3) than poorly differentiated CX32-positive ones (G3).

Language and medicine in the Zamenhof family

The Zamenhof family is famous for Dr Ludwik Lejzer Zamenhof (1859-1917), who created the artificial language Esperanto and who initiated a social movement for peace and against any sort of discrimination. Ludwik was an ophthalmologist. Adam, Leon, Alexander, and Julian Zamenhof were medical doctors and noted surgeons, while Sophia Zamenhof was a paediatrician. Ludwik Zamenhof often referred to the biblical story of the Tower of Babel, in which diversity of languages was the punishment for builders who were arrogant and uncaring. With the help of Esperanto, the Zamenhofs metaphorically wanted to overcome the curse of Babel and restore the sense of human unity.

Comparative evaluation of estrogen and progesterone receptor expression with connexins 26 and 43 in endometrial cancer

Progression of numerous neoplasms could involve alterations of gap junction channels composed of connexins (Cxs). Disorders of expression and cellular displacement of Cxs were also found in endometrial cancer. Gap junctional intercellular communication can be regulated by wide array of agents, for instance, growth factors, oncogenes, and steroid hormones. Nevertheless, expressions of Cxs and progesterone receptor (PR) were not compared in human tissues. This study focused on assessment of expression of estrogen receptor alpha (ERalpha) and PRs in relation to the expression of Cx26 and Cx43 in 88 cases of endometrial cancer and analysis of these proteins' expression in comparison with anatomoclinical features. Positive ERalpha and PR nuclear staining was present in 66 (75%) and 60 (68.2%) of all studied tumors, respectively. Positive correlation was found between expression of PR and histopathologic type of tumor (P = 0.026), and negative correlation was drawn with grading (G) (P = 0.002). There were positive reactions to Cx26 and Cx43 of mainly cytoplasmic location in 60 (68.2%) and 66 (75%) of studied cancers, respectively. Progesterone receptor expression correlated negatively with Cx26 in endometrial cancers (P = 0.016, r = -0.256). Moreover, ERalpha expression positively correlated with PR expression (P < 0.001, r = 0.678). On the ground of our findings, disorders of Cx expression and altered distribution pattern occur during endometrial carcinogenesis, and it seems that PR could participate in this fact. Loss of functional gap junctions may occur because of the aberrant expression and localization of Cx26 and Cx43 in endometrial cancer.

Relationships of P53 and Bak with EPO and EPOR in human colorectal cancer

BACKGROUND

EPO (erythropoietin) counteracts p53-dependent apoptosis. EPO, which acts via its receptor EPOR, protects cells and inhibits apoptosis in normal cells and some cancer tissues by severe down-regulation of Bak. We aimed to investigate the relationship between p53 and Bak expression and EPO and EPOR in human colorectal carcinomas.

MATERIALS AND METHODS

The expression of p53 was compared with Bak, EPO and EPOR in 96 colorectal carcinomas by means of immunohistochemistry.

RESULTS

Purely nuclear p53 was significantly higher expressed in the moderately differentiated cancers in comparison with the poorly differentiated ones (p=0.007). P53 expression did not correlate with cytoplasmic markers: Bak, EPO and EPOR, but EPO and EPOR were significantly associated with Bak expression (p<0.001, r=0.524 and p<0.001, r=0.455, respectively). p53 expression was not associated with disease-free survival during the 3 years and 9 months long follow-up.

CONCLUSION

A complete disruption of association between p53 and Bak could impair of p53-dependent apoptotic pathway that involves Bak. The relationship of Bak with EPO and EPOR is evidence of their co-expression suggesting competition between EPO mediated cell survival and Bak associated apoptosis in colorectal carcinomas.

Transforming growth factor-beta1 and regulators of apoptosis

Growth inhibitory function of transforming growth factor-beta1 (TGF-beta1) is abolished in colorectal cancer cells as a consequence of mutations of various downstream signaling agents, such as p53, which fail to respond to TGF-beta1 stimulation. TGF-beta1 could also suppress T-cell-mediated anticancer immunity. We aimed at a comparison between cancer expressions of apoptosis regulators, such as p53, BCL-2-associated X protein (Bax), and B-cell leukemia/lymphoma extra-long protein (Bcl-xL), with TGF-beta1 in malignant and adjacent inflammatory cells in immunohistochemical evaluations of 108 colorectal cancers. Cytoplasm compartment of cancer cells was overloaded with TGF-beta1, and 87% of all cancers were TGF-beta1 positive (94/108). A very strong pattern of staining was detected for TGF-beta1 in cytoplasm of inflammatory cells at tumor margins. TGF-beta1 correlated with Bcl-xL and Bax in all colorectal cancers (P < 0.001, r= 0.473 and P < 0.001, r= 0.435, respectively) and subgroups of different clinicopathological features, especially in deeply invading cancers (pT3+pT4) instead of superficially growing tumors (pT1+pT2). Expression of TGF-beta1 in inflammatory infiltrates correlated with immunoreactivities to Bcl-xL of cancer cells (P= 0.024, r= 0.217). TGF-beta1 did not associate with p53, nor did TGF-beta1 of inflammatory cells correlate with Bax expression in cancer cells. Lack of correlations between TGF-beta1 and p53 proteins could indicate mutations at the TGF-beta1-dependent apoptotic pathway. Dominant positive linkage between TGF-beta1 and Bcl-xL and selective lack of association with Bax suggest TGF-beta1 could support colorectal cancer cell survival. The pattern of correlations seems to confirm a remarkable shift from TGF-beta1-dependent suppression of cancer growth by apoptosis to inhibition of anticancer immunity by TGF-beta1.

Relations of TGF-beta1 with HIF-1 alpha, GLUT-1 and longer survival of colorectal cancer patients

AIMS AND METHODS

During colorectal carcinogenesis, transforming growth factor beta 1 (TGF-beta1) undergoes a functional change from suppression of cancer cell proliferation to inhibition of T cell mediated anti-cancer immunity. We aimed to evaluate relations among TGF-beta1 and cancer cell survival factors hypoxia inducible factor-1 alpha (HIF-1 alpha) and glucose transporter 1 (GLUT-1) by immunohistochemistry in 108 colorectal cancers.

RESULTS

TGF-beta1 was detected in 87% (94/108), HIF-1 alpha in 85% (92/108), and GLUT-1 in 65% (70/108) of colorectal cancers. Not only did TGF-beta1 accumulate in cytoplasm of cancer cells but also there was strong immunoreactivity to TGF-beta1 in adjacent inflammatory cells. GLUT-1 was visualised in a membranous fashion while HIF-1 was expressed in a paranuclear pattern and occasionally in nuclei of malignant cells. Cancer immunoreactivities to TGF-beta1 correlated with HIF-1 alpha (p < 0.001, r = 0.516) and GLUT-1 (p < [corrected] 0.001, r = 0.355) in general and subgroups of different clinicopathological traits. TGF-beta1 expressions of inflammatory infiltrates correlated with longer patient survival (p = 0.05, r = 0.449) and immunoreactivities to HIF-1 alpha of cancer cells (p = 0.008, r = 0.254) particularly in node positive and deeply invading cancers but failed to associate significantly with GLUT-1.

CONCLUSIONS

HIF-1 alpha and GLUT-1 could cooperate with TGF-beta1, and TGF-beta1 might mediate cross-talk between the inflammatory environment and tumour with a favourable impact on patient survival.

Laryngologist Leon Zamenhof—Brother of Dr. Esperanto

Purpose

To reconstruct the biography of the Polish otorhinolaryngologist Leon Zamenhof (1875–1934), a brother of Ludwik Zamenhof, who is famous for invention of the international language Esperanto.

Method

Biographical information was collected from pre-World War II resources.

Results

Zamenhof developed several important new forms of treatment to help the hearing impaired. Zamenhof was especially interested in the education of deaf children and the therapy necessary to facilitate their integration into society. His significant achievements were a phonetic method of therapy for the hearing impaired and an automatic device for ear insufflation that was considered indispensable in the management of pyorrhea. In addition, Zamenhof initiated various forms of social support among physicians within the medical community of Warsaw, Poland; made health care available to children with hearing impairments; and organized a Jewish school for deaf children. Zamenhof tried to change public attitudes toward deafness, working to promote the integration of the deaf into wider society. He also translated Polish literature into Esperanto.

Conclusions

With similar aims to his brother Ludwik, Leon Zamenhof strived to enhance and broaden communication among people who could not hear and to persuade people to change their attitudes about deafness.

Dr Adam Zamenhof (1888-1940) and his insight into ophthalmology

Adam Zamenhof was greatly influenced by his father, Ludwik Zamenhof, who designed the international language Esperanto. Like his father, he became an ophthalmologist and joined the Esperanto movement. He published in the field of ophthalmology and was soon chosen as head of an ophthalmology department. He subsequently became Chief of the Orthodox Jewish Hospital at Czystem in Warsaw. He was active in the leadership of the Bialystok-Warsaw Chamber of Medical Doctors. He perished in the Nazi Holocaust (Shoah) but all Zamenhof's ideals that Adam served as a doctor and social activist remain still alive.

[Structure and physiological function of connexin proteins]

Connexins are integral transmembrane proteins which form specialized hemichannels (connexons) in the plasma membrane. These structures make up gap junctions in adjacent cells which allow for rapid propagation of action potential and slow diffusion of nonorganic ions, secondary messengers, and other small water-soluble molecules (<1.0-2.0 kDa). Connexin proteins are crucial for the formation of gap junctions. Twenty human and 21 murine connexin isoforms (23-64 kDa) have been described so far. Traditional nomenclature in the CxMW format takes into account only the molecular weight of a given connexin. A more recent classification is based on structural gene similarities, their homology and sequence, as well as the length of connexins' cytoplasmic domains. Connexins, as all proteins, have a unique amino-acid sequences and molecular weights and exhibit specific biochemical properties. However, all of them have a common 3-D structure with four hydrophobic transmembrane domains (TM1-TM4), one cytoplasmic (CL) and two extracellular (E1-2) loops, and C- and N-terminal cytoplasmic regions. The cytoplasmic loop and C-terminal regions bind other structural proteins, creating a protein complex crucial for synchronized intercellular communication.

Comparison of STAT3 with HIF-1alpha, Ob and ObR expressions in human endometrioid adenocarcinomas

Signal transducer and activator of transcription (STAT3) maintained invasiveness of endometrial cancer cell line. STAT3 mediated signaling for oncogenic growth stimulated by leptin (Ob) and hypoxia-inducible factor 1 (HIF-1). Therefore, we studied STAT3 in relation with HIF-1alpha, Ob, leptin receptor (ObR) and clinical and pathological variables with immunohistochemistry in 48 human endometrioid adenocarcinomas. Nuclear location was a proof of activity of STAT3 and HIF-1 and it was mainly characteristic for granular anti-STAT3 staining and rarely for diffuse HIF-1alpha expression. HIF-1alpha, Ob and ObR presented cytoplasmic granular immunoreactivities. Positive staining for STAT3, HIF-1, Ob and ObR occurred in 75%, 79%, 60% and 31% of cancers, respectively. Anti-STAT3 staining did not significantly vary with grading, staging and patients' age. STAT3 correlated with Ob (p=0.048, r=0.290) and with HIF-1alpha (p=0.004, r=0.407) in all cancers but it failed to associate with ObR at all. In opposition to the absence of significant relationship between STAT3 and Ob, STAT3 correlated with HIF-1alpha in well differentiated cancers (G1), poorly differentiated tumors (G3), pT1b neoplasms, compound group of pT1c, pT2a, pT2b tumors, and older patients over their sixties. STAT3 mediated signaling pathways that engage leptin and HIF-1alpha could only be partially reflected in correlations between STAT3 and Ob or STAT3 and HIF-1alpha in the examined neoplasms. Nevertheless, STAT3 failed to mark cancer advancement, so progressive significance of STAT3 is questionable in endometrioid adenocarcinomas.

Erythropoietin and erythropoietin receptor in colorectal cancer

Erythropoietin via erythropoietin receptor effectively prevents anemia, giving reasons for a clinical use of erythropoietin in patients with colorectal cancers. However, erythropoietin seems to promote survival of the neoplastic cells in hypoxic environment. The aim of this study was to evaluate immunohistochemically the expression of erythropoietin and erythropoietin receptor in 136 primary colorectal cancers with a correlation to different anatomo-clinical features. Erythropoietin correlated with erythropoietin receptor in colorectal cancers (r = 0.547, P < .00001). Erythropoietin and erythropoietin receptor expressions were statistically higher in adenocarcinomas versus mucinous carcinomas (P = .05 and P = .03, respectively) and in moderately (G2) versus poorly differentiated (G3) tumors (P = .001 and P = .02, respectively). This in vivo study is the first study that provides evidences for the presence of erythropoietin and erythropoietin receptor in human colorectal cancer. The expressions of these proteins strictly depended on grading because the better histological differentiation probably comes from trophic influence of erythropoietin and erythropoietin receptor.

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.

Tadeus Reichstein, co-winner of the Nobel Prize for Physiology or Medicine: on the occasion of the 110th anniversary of his birth in Poland

Tadeus Reichstein (1897-1996) was the first scientist born in Poland to receive the Nobel Prize in Medicine or Physiology (1950) for the "discovery of hormones of the adrenal cortex, their structure and biological effects", as stated by the Nobel Prize Committee. His family being deeply devoted to Polish cultural and historical heritage, his first name was given to him after Tadeus Kosciuszko, a chief commander of the 18th century Polish uprising named the Kosciuszko Insurrection. As a child, he emigrated with his family to Switzerland, where he was much later to become involved in numerous research studies on steroids on an international scale. It was Tadeus Reichstein who isolated and synthesized desoxycorticosterone, which still remains the drug of first choice in the treatment of Addison's disease. Additionally, thanks to his strategy for the mass production of Vitamin C, the cost of this agent was drastically reduced thus enabling its widespread therapeutic use. In our divided world so often torn by tremendous conflicts, there is a great need to both remember and commemorate such distinguished people as Tadeus Reichstein who, despite the apparent "borders" between different nationalities and cultures, have demonstrated through their work the huge need for harmonious collaboration in the development of science.

Cumulative expression of HIF-1-alpha, Bax, Bcl-xL and P53 in human colorectal cancer

AIMS AND METHODS

Hypoxia-inducible factor (HIF-1) which contains oxygen regulated HIF-1alpha subunit maintains cytoprotective defence against hypoxic injury by induction of numerous genes. However, apoptotic regulators such as Bcl-xL, Bax and P53 have not been associated with HIF-1 dependent regulation in immunohistochemical evaluation of human colorectal cancer tumours so far. Thus, we visualised these proteins immunohistochemically and using Spearman's test compared for the first time their expression in regard to different clinicopathological traits in 123 (113 for P53 evaluation) human colorectal cancers.

RESULTS

HIF-1alpha correlated with Bcl-xL or Bax in all patients and particularly in node negative and node positive cancers, deeper intramural tumours (pT3+pT4) and adenocarcinomas. There was no significance in a small group of tumours with lesser extent through intestinal walls (pT1+pT2). In addition HIF-1alpha associated with Bcl-xL in mucinous cancers. Moreover, HIF-1alpha correlated with Bcl-xL or Bax in moderately (G2) and poorly differentiated (G3) cancers, rectal and colonic tumours and in different sex and age groups. P53 correlated only with Bax exclusively in younger patients.

CONCLUSIONS

HIF-1alpha may influence expression of Bax or Bcl-xL, at least indirectly, as correlations between HIF-1alpha and Bax or Bcl-xL occur constantly.

Overexpression of the obesity hormone leptin in human colorectal cancer

BACKGROUND

Leptin is an adipocyte-derived neurohormone, high levels of which are found in obese individuals. Leptin controls energy expenditure, acting in the brain, and regulates different processes in peripheral organs. Recent studies have suggested that leptin may be involved in cancer development and progression.

AIMS

To analyse leptin expression in human colorectal cancer as well as in colorectal mucosa and colorectal adenomas.

METHODS

Leptin expression was assessed by immunohistochemistry in 166 colorectal cancers, 101 samples of colorectal mucosa and 41 adenomas. Leptin concentration in colorectal cancer was correlated with selected clinicopathological features.

RESULTS

Immunoreactivity for leptin was observed in 51.2% (85/166) of primary colorectal cancers. In adenomas leptin expression was observed in 14.6% (6/41) of studied cases. In normal mucosa, leptin was present at low levels, except in tumour bordering areas where its concentration appeared to reflect levels in the adjacent cancer tissue. Leptin expression in colorectal cancer significantly correlated with tumour G2 grade (p = 0.002) as well as with histological type (adenocarcinoma) of tumours (p = 0.044).

CONCLUSIONS

Results indicate that leptin is overexpressed in human colorectal cancer, which suggests that the hormone might contribute to colorectal cancer development and progression.

STAT1 and STAT3 as intracellular regulators of vascular remodeling

The roles of signal transducers and activators of transcription (STAT) proteins are widely discussed in the pathogenesis of cardiovascular diseases. It is highly probable that STAT1 and STAT3 are activated during proliferation and inflammation inside atheromatous plaques. Luminal surfaces of endothelium become thrombogenic because of STAT1-dependent induction of MHC II and STAT3-regulated recruitment of phospholipase A2. As with STAT1, STAT3 seems to mediate stimulation of vascular wall cells by VEGF, HGF, and Ang II. STAT3 can contribute to counteracting apoptosis by eventual cooperation with c-fos and the bcl-xl gene. As pharmacological agents called statins are reported to regulate activities of STAT proteins, these signal messenger proteins could serve as targets for anti-atherogenic therapy. We attempted to review the role of STAT1 and STAT3 proteins in vascular remodeling.

The effect of chemotherapy on Ki-67, Bcl-2 and Bak expression in primary tumors and lymph node metastases of breast cancer

The aim of this study was the analysis of Ki-67, Bcl-2 and Bak expression in primary tumor and axillary lymph node metastases of breast cancer as well as an attempt to assess preoperative chemotherapy influence on the mentioned markers with regard to changes in the morphological appearance of the primary tumor and its metastases. Immunohistochemical examinations of Ki-67, Bcl-2 and Bak expression were conducted on sections collected from 135 patients treated surgically on invasive ductal breast cancer. Sixty-four of these patients were administered preoperative chemotherapy, whilst on 71 patients the surgery was performed without initial chemotherapy. In the group of patients without preoperative chemotherapy positive correlation in Ki-67 and Bcl-2 expression between primary tumors and lymph node metastases (p<0.0001, r=0.707; p<0.0001, r=0.604, respectively) was observed. In the group of patients after chemotherapy positive correlation between primary tumors and lymph node metastases in case of Bcl-2 and Bak proteins (p<0.04, r=0.424; p<0.02, r=0.478, respectively) was observed. It was also found that preoperative chemotherapy has an influence on the expression of proteins connected with proliferation and apoptosis and thus, it can influence neoplastic process biology. It does not have any significant impact on the proapoptotic Bak protein expression either in primary tumor or in lymph node metastases of breast cancer. However, it is related to lower expression of antiapoptotic Bcl-2 protein (p<0.0005) and of Ki-67 proliferation marker (p<0.03) in primary tumors, which indirectly indicates a beneficial influence of preoperative chemotherapy on the primary tumor. Concurrently, the influence of neoadjuvant therapy on lymph node metastases seems to be relatively small, which can limit its effectiveness.

Expression of leptin, leptin receptor, and hypoxia-inducible factor 1 alpha in human endometrial cancer

Recent studies suggested that Ob (Ob) and its receptor (ObR) could be involved in the pathogenesis of various human malignancies, among others in endometrial cancer. Moreover, hypoxia, which is associated with solid tumors, might stimulate, through hypoxia-inducible factor 1alpha (HIF-1alpha), expression of Ob and ObR. In this article, we analyzed by immunohistochemistry the expression of Ob, ObR, and HIF-1alpha in 60 cases of human endometrial cancer tissues as well as in 25 cases of normal endometria. Additionally, we assessed correlations among studied proteins as well as relationships with selected clinicopathological features of endometrial cancer. Immunoreactivity for Ob, ObR, and HIF-1alpha protein was observed in 56.7%, 30.0%, and 78.3% of endometrial cancers, respectively. The expression of HIF-1alpha showed a significant positive correlation with Ob (P < 0.0001, r = 0.573) and ObR (P = 0.020, r = 0.299). Moreover, we noted positive correlation between Ob and ObR (P = 0.001, r = 0.429). No statistically significant relationship was revealed between Ob, ObR, and HIF-1alpha protein in regard to patient's age, histological grade, and extent of tumor growth (pT). In conclusion, HIF-1alpha, which is related to tissue hypoxia in endometrial cancer, seems to be associated with overexpression of Ob and ObR. Ob could exert autocrine effect to stimulate endometrial cancer progression. Thus the autocrine Ob loop should be taken into consideration as a novel potential target in endometrial cancer prevention and treatment.

To heal the mind's eye of hate--Dr. Ludwik Zamenhof

Ludwik Zamenhof (1859-1917), born in Poland, invented and propagated Esperanto - an artificial, easy-to-learn language. Literally meaning "language of hope," Esperanto was constructed to avoid misunderstandings, establish communication and facilitate harmony among different nationalities. Simply, he wanted people to accept one another despite observed differences. He was a skilled ophthalmologist, but figuratively, he wished to heal the eyes of humankind to look without hate, just as the biblical Tobias removed the cataract from the corners of his father's eyes to restore his sight.

Rudolph Weigl (1883-1957)--a scientist in Poland in wartime plus ratio quam vis

Rudolph Weigl gained a high estimation for his spectacular invention of the first efficient vaccine against typhus fever. Although born a German native speaker, he changed into a great Pole with Polish education and upbringing in a patriotic atmosphere. His scientific career developed in the Universities of Lvov, Cracow and Poznan. For him, academic employment was a constant exploration of practical truths and a response to human needs, and this remained a deep obligation during his lifetime. His vaccine saved millions, particularly during World War II. Despite many nominations, he was never awarded the Nobel Prize.

Insulin-like growth factor-I receptor correlates with connexin 26 and Bcl-xL expression in human colorectal cancer

Insulin-like growth factor (IGF) and its receptor (IGF-IR) play an important role in mitogenesis, apoptosis, growth, and proliferation of several types of cancers. Overexpression of IGF-IR in colorectal cancer is associated with increase of cancer cell proliferation and migration as well as inhibition of apoptosis. In our previous reports we demonstrated correlations between IGF-IR and apoptosis. Moreover, we observed relationships between connexin26 (Cx26) expression and apoptotic markers in human colorectal cancer. Recently, it has been shown that expression of connexins and gap junction (GJ) functions are also regulated by growth factors, including IGF-I. Therefore, in this study we have focused on the relationships between IGF-IR and Cx26 as well as Bcl-xL expression. A total number of 115 cases of colorectal cancer were examined by immunohistochemistry, using the avidin-biotin-peroxidase method. Associations among the above proteins were assessed in the entire group of colorectal cancer patients and its subgroups, depending on lymph node involvement (N0 and N1), histological grade (G2 and G3), extent of tumor growth (pT1+pT2 and pT3+pT4), histopathologic type (adenocarcinoma and mucinous carcinoma), sex, age (<or=60 and>60), and tumor site (colon and rectum). The expression of IGF-IR, Cx26, and Bcl-xL was noted in 47%, 56.5%, and 75.6% of the tumors, respectively. In the entire group of patients we found a positive correlation between IGF-IR and Cx26 (P<0.0001, r=0.374) as well as between IGF-IR and Bcl-xL (P<0.0001, r=0.344). Our results may suggest that the insulin-like growth system is involved in regulation of apoptosis and probably connexin expression in colorectal cancer cells.

Clinicopathological significance and linkage of the distribution of HIF-1alpha and GLUT-1 in human primary colorectal cancer

HIF-1alpha induces GLUT-1 expression, and their presence has been evaluated in colorectal cancer. However, the expressions of GLUT-1 and HIF-1alpha have not been investigated together with reference to clinicopathological characteristics in human colorectal cancer. The aim of our study was to compare the expression of HIF-1alpha and GLUT-1 with various clinicopathological features of colorectal cancer. The presence of HIF-1alpha and GLUT-1 was visualized immunohistochemically in 123 primary tumors. Membranous localization of GLUT-1 was found in multifocally necrotizing cancer samples, while pure cytoplasmic perinuclear, mostly supranuclear GLUT-1 accumulation was characteristic of cancer fields with lack of necrosis. HIF-1alpha was located in the cytoplasm and occasionally in the nuclei of cancer cells. Immunoreactivity to GLUT-1 was significantly higher in node-positive cancers compared with nodenegative ones (p=0.04), confirming our earlier results obtained on a larger number of patients. Non-mucinous adenocarcinomas expressed GLUT-1 and HIF-1alpha with significantly greater frequency than mucinous adenocarcinomas (p=0.002, p=0.0002, respectively). GLUT-1 and HIF-1alpha expression did not differ in relation to tumor stage, location, or patients' age or gender. In contrast to that of GLUT-1, expression of HIF-1alpha correlated with grade (p=0.00003) without difference with regard to pN status. HIF-1alpha expression correlated with GLUT-1 expression in the whole patient population, as well as in all clinicopathological groups except for the pT1+pT2 group. Although the coexpression of cytoplasmic HIF-1alpha and GLUT-1 does not directly prove the dependence between HIF-1 as a nuclear transcriptional factor and GLUT-1 as its downstream protein, it is evidence of their simultaneous upregulation. The extranuclear accumulation of HIF-1alpha and GLUT-1 requires further studies to explain its significance in colorectal cancer.

The effect of chemotherapy on status of estrogen receptors in primary tumors and lymph node metastases of human ductal breast cancer

The aim of the study was the evaluation of ERalpha and ERbeta expression in primary tumors and lymph node metastases of breast cancer as well as the assessment of the influence of preoperative chemotherapy on these receptors with regard to changes in morphological appearance of primary tumors and their metastases. Immunohistochemical examinations were conducted on surgically removed ductal invasive breast cancers and their lymph node metastases of 135 patients. Seventy-one patients were spared preoperative chemotherapy which was administered to other 64 patients. Primary breast cancers with preoperative chemotherapy showed lower mean percentage of cells with a positive reaction to ERalpha and ERbeta as compared to primary tumors without preoperative chemotherapy. There were positive correlations among primary tumors and lymph node metastases regardless of preoperative chemotherapy applied. On the other hand, ERalpha and ERbeta expressions were negatively correlated in primary tumors without chemotherapy in contrast to primary tumors after chemotherapy. Furthermore, it was observed that preoperative chemotherapy was responsible for significantly less damage to lymph node metastases of breast cancer in comparison to primary tumors. In cases of such advanced damage of primary tumors that made determination of estrogen receptor expression impossible, their evaluation was performed on metastases to regional lymph nodes. Although preoperative chemotherapy did not severely impair estrogen receptor expression, presented changes of their distribution are a sufficient reason for simultaneous labeling of estrogen receptors in both primary tumors and metastases due to various sensitivity to chemotherapy of primary cancers in comparison with involved lymph nodes.

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.

STAT3, HIF-1alpha, EPO and EPOR - signaling proteins in human primary ductal breast cancers

STAT3 upregulates expression of HIF-1 induced EPO. Receptor EPOR was reported to activate STAT3. Our study was aimed at demonstration of tissue immunoreactivities of those proteins and determination of their relationships in reference to clinicopathological variables of breast cancers. We detected STAT3, HIF-1alpha, EPO and EPOR in specimens of 76 human, female, ductal breast cancers by immunohistochemistry. STAT3 was detected in 38 of 76 cancers (50%). HIF-1alpha was found in 55 cases (72%). EPO positive tumors comprised 89% of all the cancers (68 cases). EPOR was also visualized in 55 cases (72%). Anti-HIF-1alpha and anti-STAT3 stained nuclei and cytoplasm of breast cancer cells in diffuse and finely granular fashion. Strong membranous expressions of EPO and EPOR were distributed in cytoplasmic and membranous granularity or diffuse staining. STAT3 correlated with HIF-1 in general (r=0.4012, p<0.0001) and in different patients' subgroups. STAT3 was significantly associated with EPO and EPOR in all the cancers (r=0.2370, p=0.039 and r=0.3336, p=0.003, respectively). Besides a correlation between STAT3 and EPOR in node negative ones, STAT3 wasn't related to EPO and EPOR in remaining subgroups. HIF-1alpha correlated with EPO and EPOR in most of analyzed groups. Immunoreactivity to EPO generally was associated with EPOR (r=0.3520, p=0.002). Statistically analyzed distributions of the proteins reflected functional dependences among STAT3, HIF-1alpha, EPO and EPOR in cellular signal conduction.

Increased expression of gap junction protein--connexin 32 in lymph node metastases of human ductal breast cancer

Gap junctions are specialized cell membrane channels composed of connexins (Cxs), which mediate the direct passage of small molecules between adjacent cells. They are involved in the regulation of cell cycle, cell signaling and differentiation as well as probably invasion and metastasis. Up to now, Cx32 status in human breast cancer has not been studied. Consequently, the aim of the present study was the evaluation of the expression of connexin 32 (Cx32) in primary breast tumors (PTs) and matched-paired metastases to lymph nodes (MLNs) in correlation with selected clinicopathological features. Tissue samples from 79 women were examined by immunohistochemistry, using the streptavidin-biotin-peroxidase complex technique for Cx32. Cytoplasmic expression of Cx32 was detected in 31 of 79 breast cancers (39.2%). Both epithelial and myoepithelial cells of normal ducts adjacent to the tumor did not express Cx32. Increased expression of studied Cx was observed in metastases to lymph nodes relative to primary tumors. Additionally, Cx32-negative primary tumors developed Cx32-positive metastases. Statistical comparisons of Cx32 expression in the matched pairs indicate that this protein significantly increased in lymph node metastases compared to primary tumors (p<0.001). The expression of Cx32 in primary breast cancer was not statistically associated with age of patients, tumor size, lymph node status, but we observed a tendency toward association between Cx32 expression and histological differentiation. In conclusion, transformed cells may have an ability to produce Cxs also atypical for normal cells. Increased expression of Cx32 in metastases to the lymph nodes might reflect alteration in connexin gene transcription during breast carcinogenesis and finally, it may be a sign of more malignant phenotype of cancerous cells.

Significant Coexpression of GLUT-1, Bcl-xL, and Bax in Colorectal Cancer

Hypoxic cancer cells overexpress Glucose transporter 1 (GLUT-1) to accelerate glucose intake mainly for low effective, anaerobic respiration, so that they would not die of oxygen deficiency. Ischemic cell injury triggers apoptosis. Regulators of cell suicide like Bax and Bcl-xL combine their functions to cause apoptosis or to rescue cells from death. GLUT-1, Bax, and Bcl-xL are of prognostic significance in colorectal cancer but they have not been compared, yet. Thus, we aimed to determine eventual correlations between GLUT-1, Bax, and Bcl-xL in association with different clinicopathological features of colorectal cancer patients. Expressions of the proteins were evaluated in specimens of 150 colorectal patients by immunohistochemistry. The levels of tissue expressions were statistically analyzed with Spearman's correlation test. As in group of all the patients, GLUT-1 matched Bcl-xL and Bax in statistically significant manner regardless of different node status, grade of histological differentiation, histopathological type, tumor site, gender and age of patients. GLUT-1 correlated highly with Bcl-xL in both groups of various tumor growth extent: pT1 + pT2 and pT3 + pT4 tumors (P < 0.016, r = 0.6340, P < 0.0001, r = 0.5204, respectively). Bax correlated with GLUT-1 (P < 0.0001, r = 0.4284) and Bcl-xL (P < 0.0001, r = 0.5233) in pT3 and pT4 tumors without any statistical significance in a homologous comparison at pT1 and pT2 stage (P > 0.173, r = 0.1078, P > 0.744, r = 0.1, respectively). Significant coexpression of GLUT-1, Bcl-xL, and Bax could point to cooperation of these regulatory proteins in elimination due to irreversible injury, adaptation to hypoxia, reduction of further damage, and survival of colorectal cancer cells.

Expression of leptin and its receptor in female breast cancer in relation with selected apoptotic markers

Leptin and its receptor may be engaged in pathogenesis of breast cancer among various human tumors. In vitro investigations showed leptin-mediated escalation of estrogen synthesis and boosted activity of estrogen receptor ERalpha. Furthermore, leptin induced growth of malignant cells, counteracted apoptosis and stimulated cell migration as well as overexpression of angiogenic factors and degrading enzymes that split network of intercellular matrix. On the other side, leptin has been reported to favor apoptosis, lately. Proapoptotic effect of leptin action was revealed in interstitial cells of bone marrow and adipocytes. Our past reports provide evidences for overexpression of leptin and its receptor in breast cancer in comparison with benign mammary lesions. In current study we aimed at assessment of eventual relationships between leptin, leptin receptor and selected protein regulators of apoptosis in breast cancer. We applied immunohistochemistry for leptin, leptin receptor, anti-apoptotic Bcl-2 and Bcl-xL as well as pro-apoptotic Bak and Bax expression assessment in 106 cases of human breast cancers. The immunoreaction was graded and statistically evaluated. Expression of leptin was positively correlated with Bcl-xL, Bak and Bax (p<0.001, r=0.614; p<0.001, r=0.518; p<0.001, r=0.511, respectively). Statistical significances were noted between expression of leptin receptor and Bcl-xL or Bax (p=0.011, r=0.210; p<0.001, r=0.313, respectively). No correlation was encountered between leptin and Bcl-2, either leptin receptor and Bcl-2 or leptin receptor and Bak. On the basis of obtained results, leptin system could interfere in balance among expressions of pro- and anti-apoptotic proteins and regulate cell turnover and--by means of it--facilitate breast cancer progression.

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.

Leptin--from regulation of fat metabolism to stimulation of breast cancer growth

Leptin restricts intake of calories as a satiety hormone. It probably stimulates neoplastic proliferation in breast cancer, too. Growth of malignant cells could be regulated by various leptin-induced second messengers like STAT3 (signal transducers and activators of transcription 3), AP-1 (transcription activator protein 1), MAPK (mitogen-activated protein kinase) and ERKs (extracellular signal-regulated kinases). They seem to be involved in aromatase expression, generation of estrogens and activation of estrogen receptor alpha (ERalpha) in malignant breast epithelium. Leptin may maintain resistance to antiestrogen therapy. Namely, it increased activation of estrogen receptors, therefore, it was suspected to reduce or even overcome the inhibitory effect of tamoxifen on breast cell proliferation. Although several valuable reviews have been focused on the role of leptin in breast cancer, the status of knowledge in this field changes quickly and our insight should be continuously revised. In this summary, we provide refreshed interpretation of intensively reported scientific queries of the topic.

Increased expression of leptin and the leptin receptor as a marker of breast cancer progression: possible role of obesity-related stimuli

PURPOSE

Recent in vitro studies suggested that the autocrine leptin loop might contribute to breast cancer development by enhancing cell growth and survival. To evaluate whether the leptin system could become a target in breast cancer therapy, we examined the expression of leptin and its receptor (ObR) in primary and metastatic breast cancer and noncancer mammary epithelium. We also studied whether the expression of leptin/ObR in breast cancer can be induced by obesity-related stimuli, such as elevated levels of insulin, insulin-like growth factor-I (IGF-I), estradiol, or hypoxic conditions.

EXPERIMENTAL DESIGN

The expression of leptin and ObR was examined by immunohistochemistry in 148 primary breast cancers and 66 breast cancer metastases as well as in 90 benign mammary lesions. The effects of insulin, IGF-I, estradiol, and hypoxia on leptin and ObR mRNA expression were assessed by reverse transcription-PCR in MCF-7 and MDA-MB-231 breast cancer cell lines.

RESULTS

Leptin and ObR were significantly overexpressed in primary and metastatic breast cancer relative to noncancer tissues. In primary tumors, leptin positively correlated with ObR, and both biomarkers were most abundant in G3 tumors. The expression of leptin mRNA was enhanced by insulin and hypoxia in MCF-7 and MDA-MB-231 cells, whereas IGF-I and estradiol stimulated leptin mRNA only in MCF-7 cells. ObR mRNA was induced by insulin, IGF-I, and estradiol in MCF-7 cells and by insulin and hypoxia in MDA-MB-231 cells.

CONCLUSIONS

Leptin and ObR are overexpressed in breast cancer, possibly due to hypoxia and/or overexposure of cells to insulin, IGF-I, and/or estradiol.

Evaluation of Apoptosis Markers in Conjunctival and Eyelid Benign and Malignant Tumors

The balance between cell proliferation and programmed cell death plays a crucial role in malignant development. Bcl-2 family proteins, including proapoptosis protein Bak and antiapoptosis protein Bcl-2, regulate the apoptotic process. Mutation of the p53 gene, which results in P53 protein accumulation, was observed in many types of human cancer. The aim of our study was to evaluate immunohistochemical Bcl-2, Bak, and P53 protein expression and the relation between these proteins in conjunctival and eyelid benign and malignant tumors. We examined a series of 42 papillomas (CEP), 12 squamous cell cancers (SCC), and 19 cases of basal cell cancer (BCC). The age in the CEP group ranged from 18-94 years, and in the SCC and BCC groups from 42-87 years. Staining patterns were correlated with sex, age, and tumor localization. P53 protein-positive immunostaining was observed in 71% of cases, Bcl-2 in 83.9%, and Bak in 74.2 cases in the SCC and BCC groups. In the CEP group, P53 overexpression was observed in 90.5% of cases, Bcl-2 in 71.4%, and Bak in 76.2%. No statistically significant correlation was found between examined protein expression and sex, age, and tumor localization. An inverse correlation was observed between P53 and Bak protein expression in the CEP group. No statistically significance correlation was noted between Bcl-2 and P53 and Bcl-2 and Bak protein expression in both examined groups. The obtained data suggests that P53 and Bcl-2 protein expression coupled with decreasing Bak expression are associated with apoptosis and proliferation as well as malignant progression in conjunctival and eyelid tumors.

Analysis of the relationship between cancer procoagulant activity and PCNA and Ki-67 expression in cases of common and cellular uterine leiomyomas

PURPOSE

Histological subtypes of uterine leiomyomas may substantially differ in their cellular biology, including the intensity of synthesis of cancer markers and expression of cell proliferation markers. The present investigation aimed to determine the activity of cancer procoagulant (CP) in subtypes of leiomyomas, including cellular leiomyomas, and to verify whether these activities correlate with immunoexpression of cell proliferation markers: the proliferating cell nuclear antigen (PCNA) and Ki-67.

MATERIALS AND METHODS

Preoperative peripheral venous blood and postoperative tissue material were obtained from 24 women operated on in a tertiary referral academic department. The activity of CP in serum was measured with the use of a coagulative method according to Gordon and Benson, and in tissue homogenates with the use of a spectrophotometric method according to Colucci et al. The control serum values were obtained from 20 healthy women without any gynecological disease, and the control solid tissue values from histologically confirmed postoperative normal reproductive tissues obtained from six patients. PCNA and Ki-67 expression were determined immunohistochemically using monoclonal antibodies.

RESULTS

Both the tissue and serum activity for CP was considerably higher for common leiomyomas and cellular leiomyomas than for control tissues, but did not differ significantly between the leiomyoma subtypes. Intratumor CP activity significantly correlated with PCNA expression but not with Ki-67 expression.

CONCLUSIONS

Cellular leiomyomas do not differ substantially in the serum and intratumor CP activity from common leiomyomas. There is a relationship of intratumor CP activity with PCNA expression, a finding which requires further investigation.

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 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.

Connexins 26 and 43 correlate with Bak, but not with Bcl-2 protein in breast cancer

Apoptosis is a process associated with development and progression of breast cancer. The association between connexins and programmed cell death has only been demonstrated in a few studies. The aim of the present study was the evaluation of Cx26 and Cx43 expression in breast cancer in correlation with Bcl-2 and Bak proteins as well as with selected clinicopathological features. Tissue samples from 71 women were examined by immunohistochemistry, using the streptavidin-biotin-peroxidase complex technique for Cx26, Cx43, Bak and Bcl-2. Cytoplasmic expression of Cx26 and Cx43 was detected in 34 (47.9%) and 61 (85.9%) of breast cancers, respectively. Bcl-2 and Bak expression was found in 59 (83%) and 50 (70%) of studied cases, respectively. We found a positive correlation between Cx26 and Bak expression (r=0.541, p<0.0001) as well as between Cx43 and Bak (r=0.589, p<0.0001), but not between the studied connexins and Bcl-2. The expression of Cx26 was not associated with age, tumor size, lymph node status or histological grade. However, we observed an association between Cx43 expression and histological grade G3 (p<0.04). Cytoplasmic localization of evaluated connexins supports the concept of alterations in connexins expression in breast cancer cells. The associations of evaluated connexins with Bak protein could suggest that connexins localized in the cytoplasm may participate in signaling apoptotic pathways.

Evaluation of serum cathepsin B and D in relation to clinicopathological staging of colorectal cancer

AIM: Proteolytic degradation of the extracellular matrix facilitates cancer invasion and promotes metastasis. The study aims at evaluation of preoperative and postoperative serum cathepsins B and D levels in correlation with selected anatomoclinical features of colorectal cancer.

METHODS: Blood samples were collected from 63 colorectal cancer patients before curative operation of the tumor 10 d later. Blood that was obtained from 20 healthy volunteers, served as a control. The activity of cathepsin B was measured with Bz-DL-arginine-pNA as a substrate at pH 6.0, while cathepsin D activity was determined with urea-denatured hemoglobin (pH 4.0).

RESULTS: The preoperative and postoperative activities of cathepsin B were significantly (P < 0.00001) lower in serum of colorectal cancer patients than in control group. However, postoperative values of this protease were significantly increased in comparison with preoperative ones (P = 0.031). Activity of cathepsin D appeared to be significantly higher in colorectal cancer sera (P < 0.00001) compared with controls. No statistically significant differences between preoperative and postoperative activity of cathepsin D were noted (P = 0.09). We revealed a strong linkage of cathepsins’ levels with lymph node status and pT stage of colorectal cancer.

CONCLUSION: Blood serum activities of cathepsin B and D depend on the time of sampling, tumor size and lymph node involvement. Significantly, increased activity of cathepsin D could indicate a malignant condition of the large intestine. In our work, the serum postoperative decrease of cathepsin B activity appears as an obvious concomitant of local lymph node metastasis-the well-known clinicopathological feature of poor prognosis.

Alterations in connexin26 expression during colorectal carcinogenesis

BACKGROUND

Gap junctional intercellular communication (GJIC) is a mechanism for direct cell-to-cell signalling and is mediated by gap junctions, which consist of transmembrane proteins called connexins (Cxs). Human colorectal epithelial cells express Cx32 and Cx43.

METHODS

Tissue samples (152 from colorectal cancer and 75 from adenoma) were investigated by immunohistochemistry, using the antibody for Cx26. Moreover, Cx26 was assessed in normal epithelium of the colon and rectum, adjacent to colorectal cancer.

RESULTS

In normal epithelium and adenomas, intercellular, punctate staining for Cx26 was observed. In adenomas with severe dysplasia, focally decreased expression of Cx26 was observed. Among 152 colorectal cancers, 55.9% classified only as adenocarcinoma stained positive for Cx26, but mainly cytoplasmic staining was found. We observed a positive correlation between Cx26 expression and tumor G2 grade (p < 0.005). The expression of Cx26 did not correlate with age, sex of patients, tumor localization, lymph node status or tumor size.

CONCLUSIONS

Our results show that during colorectal carcinogenesis, loss of normal intercellular Cx expression occurs. Furthermore, the cytoplasmic presence of Cx26 could indicate a different role of Cx26 in neoplastic cells than participation in GJIC.

Expression of insulin-like growth factor-I receptor, estrogen receptor alpha, Bcl-2 and Bax proteins in human breast cancer

Disturbance in expression of estrogen receptors together with changing influence of growth factor receptors and apoptosis associated proteins plays a role in breast cancer development and progression. However, immunohistochemical detection and relationships among these proteins were not often considered in relation to breast cancer and a few evaluations of expression provided mismatching results and conclusions. Consequently, we examined by immunohistochemistry the expression of the insulin-like growth factor-I receptor (IGF-IR), estrogen receptor alpha (ERalpha) and apoptosis-associated proteins, Bcl-2 and Bax, in human primary breast cancer, as well as analyzing the relationships among these proteins. The positive immunostaining for IGF-IR, ERalpha, Bcl-2 and Bax was noted in 56, 63.8, 82.8 and 50% of tumors, respectively. We observed that IGF-IR negatively correlated with ERalpha in the group of all tumors and in axillary node negative cancer (p<0.03, p<0.05, respectively), but not in the subgroup of node positive cancer. Expression of ERalpha correlated positively with Bcl-2 and negatively with Bax proteins (p<0.0001, p<0.05, respectively). We did not note significant relationships between IGF-IR and Bcl-2, or IGF-IR and Bax proteins. We found that increased Bax expression was associated with positive lymph node status, pT2 stage and G3 grade of tumors. Knowledge about alterations in the IGF-IR expression and relations of the receptor to other biological factors could help in our understanding of breast cancer biology and the importance of the IGF-IR in cancer progression as well as in effective management of breast cancer.

Expression of the insulin-like growth factor-I receptor and proapoptotic Bax and Bak proteins in human colorectal cancer

Insulin-like growth factor-I (IGF-I) and IGF-I receptor (IGF-IR), despite their well-known roles in cell survival and proliferation, can also weakly enhance apoptosis. To study the relationships between the IGF-IR and Bax as well as Bak, 144 cases of colorectal cancer were examined by immunohistochemistry, using the avidin-biotin-peroxidase method. The results were correlated with selected clinicopathological features of colorectal cancer and with the expression of IGF-IR, Bax, and Bak in normal colon mucosa. In Bax-, Bak-, or IGF-IR-positive cancers, the adjacent colorectal mucosa revealed positive immunostaining for these proteins. In the majority of Bax-, Bak-, or IGF-IR-negative tumors, we observed no staining for these proteins in adjacent mucosa. The strong immunostaining for IGF-IR, Bax, and Bak was noted in 50.8, 55.5, and 49.3% of tumors, respectively. We observed positive correlations between IGF-IR and Bax (P < 0.002, r = 0.302), between IGF-IR and Bak (P < 0.0001, r = 0.407), and between Bax and Bak (P < 0.0001, r = 0.474). No relationship was noted between IGF-IR expression and tumor grade, stage, or lymph node status. We found negative associations between Bax, Bak, and tumor grade (P < 0.01 and P < 0.003, respectively), but no relationships between Bax and Bak and tumor stage or between Bax and Bak and lymph node status. Our results demonstrate that, in addition to overexpressed IGF-IR, there are relationships between IGF-IR and proapoptotic proteins in colorectal carcinomas that could contribute to increased cell turnover and the progression of colorectal cancer.

Connexin 26 correlates with Bcl-xL and Bax proteins expression in colorectal cancer

AIM: To evaluate of Cx26 in correlation with Bcl-xL and Bax proteins in colorectal cancer.

METHODS: Immunohistochemical staining using specific antibodies was performed to evaluate the protein expression of Cx26, Bax and Bcl-xL in 152 colorectal cancer samples and the correlations among studied proteins as well as the relationships between the expression of Cx26, Bax, Bcl-xL and clinicopathological features were analyzed.

RESULTS: Both normal epithelial cells and carcinoma cells expressed Cx26, Bax and Bcl-xL, but Cx26 in cancer cells showed aberrant, mainly cytoplasmic staining. Expression of Cx26, Bax and Bcl-xL was observed in 55.9%, 55.5% and 72.4% of evaluated colorectal cancers respectively. We found the positive correlation between Cx26 and Bax expression (r = 0.561, P<0.0001), Cx26 and Bcl-xL (r = 0.409, P<0.0001) as well as between Bax and Bcl-xL (r = 0.486, P<0.0001). Association of Cx26, Bax and Bcl-xL expression with histological G2 grade of tumors was noted (P<0.005, P<0.001 and P<0.002 respectively).

CONCLUSION: Cytoplasmic presence of Cx26 and its association with apoptotic markers could indicate a distinct role from physiological functions of Cx26 in cancer cells and it could suggest that connexins might be a target point for modulations of apoptosis with therapeutic implications.