Georgia Sotiropoulou-Bonikou

Oestrogen receptor beta (ERβ) is abundantly expressed in normal colonic mucosa, but declines in colon adenocarcinoma paralleling the tumour's dedifferentiation

Oestrogen Receptor beta (ERbeta) may protect against prostate and mammary cell proliferation and malignant transformation. Epidemiological studies indicate that oestrogens may reduce colon cancer risk. Since ERalpha is minimally expressed in normal and malignant colon, the aim of this study was to investigate the expression of ERbeta in both normal colonic wall and colon cancer. ERbeta expression was evaluated by immunohistochemistry in 90 cases of colon adenocarcinoma and nearby (>30-cm away) normal colonic wall, using a monoclonal antibody. Moderate or strong nuclear immunostaining was detected in superficial and crypt epithelium, endothelial cells, vascular smooth muscle cells, lymphocytes, enteric neurons and smooth muscular cells of the normal colonic wall. Superficial epithelial cells in normal colon demonstrated a significantly higher ERbeta expression than colon adenocarcinoma cells in both genders. The decline in ERbeta expression paralleled the loss of differentiation of malignant colon cells, regardless of the tumours localisation. These findings suggest a protective role for ERbeta against colon carcinogenesis.

Expression of the 27-kDa heat shock protein (HSP27) in gastric carcinomas and adjacent normal, metaplastic, and dysplastic gastric mucosa, and its prognostic significance.

Abstract Purpose. The investigation of heat shock protein 27 (HSP27) expression in gastric cancer and adjacent normal, metaplastic, and dysplastic gastric mucosa and its correlation with clinicopathological parameters and survival of patients. Methods. Immunohistochemical methodology was performed on formalin-fixed paraffin-embedded sections by using a monoclonal anti-HSP27 antibody. HSP27 expression was screened and compared in 86 cases of gastric carcinoma and adjacent normal, metaplastic, and dysplastic gastric mucosa. Results. In the normal mucosa, HSP27 was detected in 68 out of 86 cases (79%) and was more intense in the surface and upper two-thirds of gastric foveolae. In dysplastic gastric mucosa, HSP27 immunoreactivity was usually higher than that of the adjacent normal epithelium and was parallel to the severity of dysplasia. HSP27 expression was found in 54 out of 86 (62.7%) gastric carcinomas and was significantly related to more than six metastatic lymph nodes (P =0.03). HSP27 expression was also higher in tumors of advanced stage and in those of female patients. HSP27 expression was associated with shorter overall survival in univariate analysis (P =0.04), but this relationship was not retained in multivariate analysis. Conclusions. Our findings indicate that: i) HSP27 is commonly expressed in normal gastric epithelium where it seems to exert a protective role; and ii) HSP27 is involved in gastric carcinogenesis and its expression appears to be associated with parameters of unfavorable prognosis and shorter overall survival.

PPAR-gamma is expressed and NF-kB pathway is activated and correlates positively with COX-2 expression in stromal myofibroblasts surrounding colon adenocarcinomas

Purpose: Accumulated evidence indicates that carcinogenesis is closely associated with the transformation of normal stroma into a ‘reactive’ stromal phenotype. The present study investigated the role of PPARγ, COX-2 and p-IkB-α—important molecular targets of colon cancer chemoprevention—in this stromal remodeling by evaluating and comparing the expression of these factors in stromal myofibroblasts, macrophages and endothelial cells that surround normal colonic mucosa and colon cancer. Methods: Immunohistochemical methodology was employed on archived paraffin-embedded sections prepared from tumors and adjacent normal colon from 45 patients with colon adenocarcinomas. Double immunostaining with the universal marker for myofibroblasts (alpha-smooth muscle actin/α-SMA) as second primary antibody was also performed. Results: Stromal macrophages and endothelial cells expressed these factors both in normal colonic mucosa and colon cancer. By contrast, stromal myofibroblasts expressed PPARγ, COX-2 and p-IkB-α only in colon adenocarcinomas (77.7%, 100% and 100% of cases, respectively) and not in normal colon. COX-2 and p-IkB-α expressions were strongly correlated in these cells (P<0.001). PPARγ, COX-2 and p-IkB-α expression did not correlate with the stage or differentiation of the adenocarcinomas. Conclusions: NF-kB pathway is activated and COX-2 expression is upregulated in stromal myofibroblasts surrounding colon adenocarcinomas compared to normal colon. Induction of COX-2 expression is primarily induced by NF-kB. NSAIDs, selective COX-2 inhibitors and PPARγ ligands may exert their chemoprophylactic properties through direct actions on these cells.

NF-κB/PPARγ and/or AP-1/PPARγ 'on/off' switches and induction of CBP in colon adenocarcinomas: correlation with COX-2 expression

Background and aimsSeveral studies indicate that peroxisome proliferator-activated receptor gamma (PPARγ) represses activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB) transcriptional activity and this negative cross-talk occupies an important role in carcinogenesis. The present study evaluated the differential expression profile of AP-1 constituents (c-FOS and phosphorylated-active pc-JUN), p-IκB-α (phosphorylated IκB-α, a signaling intermediate of NF-κB pathway), PPARγ, cyclic AMP-response element binding-binding protein (CBP, a known AP-1, NF-κB, and PPARγ transcriptional coactivator), epidermal growth factor receptor (EGF-R), p53, and COX-2 in normal colonic epithelial cells and colon adenocarcinoma cells.Materials and methodsImmunohistochemical methodology was performed on formalin-fixed, paraffin-embedded sections from 60 patients with colon adenocarcinomas. A molecular profile was created for each patient and the induction or down-regulation of each pathway from normal to cancer cells was documented. Relationships between transcription factors and downstream molecular targets were evaluated by Spearman’s rho correlation coefficient and validated by nonparametric Kruskal–Wallis test.Results/findingsP-IκB-α (P<0.001), CBP (P<0.001), c-FOS (P=0.047), pc-JUN (P=0.047), and EGF-R (P<0.001) were up-regulated in colon adenocarcinomas while PPARγ (P<0.001) was concomitantly down-regulated. p-IκB-α, CBP, pc-JUN, EGF-R, and p53 expression all correlated positively with COX-2 while PPARγ expression correlated inversely with COX-2.Interpretation/conclusionNF-κB/PPARγ and/or AP-1/PPARγ expressional ‘on/off’ switches are common molecular events during colorectal carcinogenesis. Down-regulation of PPARγ and induction of the CBP transcriptional coactivator can augment NF-κB and AP-1 transcriptional activities leading to up-regulation of COX-2 expression in colon adenocarcinoma cells. p-IκB-α, pc-JUN, and CBP could potentially provide the basis for future molecular-targeted anticancer therapies.

Inverse expression of estrogen receptor-β and nuclear factor-κB in urinary bladder carcinogenesis

Objectives:  To investigate the expression of nuclear factor‐κB (NF‐κB) and estrogen receptor‐β (ER‐β) signalling pathways in bladder urothelial carcinoma according to clinicopathological features, in order to elucidate their role during carcinogenesis.

EGF-R is Expressed and AP-1 and NF-κ:B Are Activated in Stromal Myofibroblasts Surrounding Colon Adenocarcinomas Paralleling Expression of COX-2 and VEGF

Background: COX-2 and VEGF are important triggers of colon cancer growth, metastasis and angiogenesis. Cox-2 promoter contains transcriptional regulatory elements for AP-1 and NF-κ:B transcription factors whilst vegf is a known AP-1 downstream target gene. We investigated whether stromal myofibroblasts surrounding colon adenocarcinomas express COX-2 and VEGF and whether activation of AP-1 and NF-κ:B, as well as expression of EGF-R parallel expression of COX-2 and VEGF in these cells. Methods: Immunohistochemical methodology was performed on archival sections from 40 patients with colon adenocarcinomas. We evaluated c-FOS, p-c-JUN (phosphorylated c-JUN), p-Iκ:B-α (phosphorylated Iκ:B-α), EGF-R, COX-2, NF-κ:B and VEGF expression in stromal myofibroblasts surrounding colon adenocarcinomas. Double immunostaining with a-smooth muscle actin and each antibody was done to verify the expression of these molecules in stromal myofibroblasts. Results: VEGF, p-Iκ:B-α, NF-κ:B, c-FOS, p-c-JUN, EGF-R and COX-2 were expressed in stromal myofibroblasts surrounding colon adenocarcinomas in the majority of cases. EGF-R, p-Iκ:B-α, NF-κ:B, c-FOS and p-c-JUN correlated positively with COX-2 and VEGF expression. Conclusion: Stromal myofibroblasts surrounding colon adenocarcinomas are an important source of VEGF and COX-2 production, while AP-1 and NF-κ:B transcription factors are activated and EGF-R is expressed in these cells and associated with COX-2 and VEGF production.

Estrogen receptor α/β, AIB1, and TIF2 in colorectal carcinogenesis: do coregulators have prognostic significance?

PurposeEstrogen receptor β (ERβ) is abundantly expressed in colorectal tissue, but its role in colorectal carcinogenesis remains elusive. Estrogen receptor coregulators, amplified in breast cancer 1 (AIB1) and transcription intermediary factor 2 (TIF2), have been well-characterized, but their expression in colorectal carcinomas has not been investigated.Materials and methodsEstrogen receptor α (ERα), ERβ, AIB1, and TIF2 protein expression were evaluated by immunohistochemistry in colorectal normal mucosa, adenomas, and adenocarcinomas from 110 patients with colorectal cancer.ResultsERα expression was rare in colorectal tissue and its expression does not appear to be associated with colorectal carcinogenesis. ERβ, AIB1, and TIF2 were detected in the nucleus of epithelial, endothelial, inflammatory, smooth muscle cells, and myofibroblasts. The expression of the three proteins was significantly increased in epithelial cells of carcinomas compared to normal mucosa. In carcinomas, a significant correlation between the levels of expression of AIB1 and TIF2 was noted. Although AIB1 overexpression was associated with local tumor invasion, it was also found to correlate independently with prolonged overall survival.ConclusionsERβ, AIB1, and TIF2 appear to be involved in colorectal tumorigenesis and might have prognostic significance.

Expression of ERα, ERβ and Co-Regulator PELP1/MNAR in Colorectal Cancer: Prognostic Significance and Clinicopathologic Correlations

Background: Estrogen receptor β (ERβ) is abundantly expressed in colorectal tissue, but its role in colorectal carcinogenesis remains elusive. ER novel co-regulator, proline-, glutamic acid- and leucine-rich protein 1 (PELP1/MNAR) has been characterized, but its expression in colorectal carcinomas has not been investigated. Methods: ERα, ERβ and PELP1/MNAR protein expression were evaluated by immunohistochemistry in colorectal normal mucosa, adenomas and adenocarcinomas from 113 patients with colorectal cancer. Results: ERα expression is extremely rare in colorectal tissue and its expression does not appear to be associated with colorectal carcinogenesis. ERβ and PELP1/MNAR were detected in the nucleus of epithelial, endothelial, inflammatory, smooth muscle cells and myofibroblasts. When intensity of staining was taken into account, the expression of both proteins was significantly increased in epithelial cells of carcinomas compared to normal mucosa. ERβ expression in epithelial cells was correlated with decreased disease progression – free survival. PELP1/MNAR overexpression in epithelial cells was found to be an independent favorable prognostic factor. Additionally, the expression of both proteins was significantly increased in stromal myofibroblasts of carcinomas compared to adenomas and normal mucosa. Conclusion: ERβ and PELP1/MNAR appear to be involved in colorectal tumorigenesis and might have prognostic significance.

Expression of estrogen receptor co-regulators NCoR and PELP1 in epithelial cells and myofibroblasts of colorectal carcinomas: cytoplasmic translocation of NCoR in epithelial cells correlates with worse prognosis

Proline-, glutamic acid-, and leukine-rich protein (PELP1) is a novel co-regulatory protein that modulates genomic and non genomic actions of estrogen receptors. Nuclear receptor co-repressor (NCoR) represses estrogen-receptor-dependent transcription. PELP1 and NCoR expression was evaluated in tissue sections from 107 formalin-fixed, paraffin-embedded colectomy specimens. Normal mucosa and adenomas were also evaluated in 77 and 29 cases, respectively. PELP1 was expressed in a dot-like pattern in the nuclei of epithelial and stromal cells. Statistical analysis revealed an increase in PELP1 expression in myofibroblasts from normal mucosa through adenomas to carcinomas. NCoR was expressed in the nuclei and the cytoplasm of epithelial cells. Nuclear expression was more common in normal mucosa, whereas cytoplasmic expression was higher in malignant epithelial cells. Additionally, NCoR was expressed in the cytoplasm of cancer-associated myofibroblasts, but was rarely noted in myofibroblasts of normal mucosa or adenomas. Cytoplasmic expression of NCoR in epithelial cells correlated with better disease-free and overall survival on univariate analysis and was an independent prognostic marker for disease-free survival on multivariate analysis. These findings suggest that deregulation of co-regulators expression in both epithelial cells and myofibroblasts may contribute to the initiation and progression of colorectal carcinoma.

Coordinated Upregulation of COX-2 and NF-κB Is a Steady Feature of Laryngeal Carcinogenesis

Background/Aims: Laryngeal cancer is the endpoint of a multistage process involving hyperplastic and dysplastic lesions, not adequately defined in their molecular aspect. Our objective was to evaluate the expression of the prostaglandin-synthesizing enzyme cyclooxygenase-2 (COX-2) and the chief transcription factor nuclear factor-ĸB (NF-ĸB) in laryngeal carcinomas and their precursors, as well as to explore any association between the two molecules. Methods: We performed paraffin section immunohistochemistry for COX-2 and the p65 subunit of NF-ĸB, in tissues from 129 patients with tumors or premalignancies. p65 cytoplasmic and nuclear immunostaining were listed individually. Results: COX-2 was positively correlated with histopathological grading from normal mucosa to carcinomas (Spearman’s coefficient rs = 0.286, p < 0.001). No association was revealed between COX-2 expression and tumor grade. p65 immunoreactivity, both of cytoplasmic and nuclear origin, increased along the carcinogenesis course, manifesting highest expression in invasive cancer (rs = 0.419, p < 0.001 and rs = 0.241, p < 0.001, respectively). Again, tumor grade had no influence on expression. COX-2 and p65 cytoplasmic, but no nuclear, expression showed a positive correlation (rs = 0.352, p < 0.001). Conclusions: This study demonstrates that lesional advance in the larynx towards cancer is marked by ongoing upregulation of COX-2 and NF-ĸB. Synchronism between individual expressions may denote a regulatory role of the latter in COX-2 transactivation.