Stratigoula Sakellariou

Dual Function of p38α MAPK in Colon Cancer: Suppression of Colitis-Associated Tumor Initiation but Requirement for Cancer Cell Survival

Colorectal cancer is frequently associated with chronic inflammation, with the intestinal epithelial barrier playing an important protective role against the infections and injuries that cause colitis. The p38α pathway regulates inflammatory responses but can also suppress tumor initiation in epithelial cells. We have found that p38α signaling has a dual function in colorectal tumorigenesis. On one side, p38α protects intestinal epithelial cells against colitis-associated colon cancer by regulating intestinal epithelial barrier function. Accordingly, p38α downregulation results in enhanced colitis-induced epithelial damage and inflammation, which potentiates colon tumor formation. Surprisingly, inhibition of p38α in transformed colon epithelial cells reduces tumor burden. Thus, p38α suppresses inflammation-associated epithelial damage and tumorigenesis but contributes to the proliferation and survival of tumor cells.

Phosphorylated 4E-binding protein 1 (p-4E-BP1): a novel prognostic marker in human astrocytomas.

Korkolopoulou P, Levidou G, El‐Habr E A, Piperi C, Adamopoulos C, Samaras V, Boviatsis E, Thymara I, Trigka E‐A, Sakellariou S, Kavantzas N, Patsouris E & Saetta A A 
(2012) Histopathology 61, 293–305

pERK activation in esophageal carcinomas: Clinicopathological associations

MAPK (mitogen-activated protein kinase) pathway is considered a control regulator in various malignant tumors but its role in esophageal carcinomas remains elusive. In our study, we examined the possible prognostic significance of MAPK pathway in human esophageal cancer. We searched for mutations in exons 18-21 of EGFR gene, codons 12 and 13 of K-RAS gene and exon 15 of B-RAF gene by high resolution melting analysis (HRMA) and pyrosequencing in 44 esophageal carcinomas. Immunohistochemistry was performed in 29 cases in order to evaluate expression levels of pERK (extracellular-signal regulated kinase). In one laser microdissected squamous cell carcinoma, a somatic K-RAS mutation at codon 12 was detected, whereas none of the cases displayed mutations in EGFR and B-RAF genes. Elevated nuclear as well as cytoplasmic pERK expression (100% and 62% of cases respectively) was observed independently of EGFR and B-RAF mutational status. Increasing pERK nuclear and cytoplasmic expression as well as the intensity of nuclear staining was found to be significantly correlated with tumor grade in univariate and multivariate statistical analysis. Our findings depict the presence of activated ERK despite the low frequency of upstream alterations, implicating ERK activation in the acquisition of a more aggressive phenotype in esophageal cancer.

Bilateral adrenocortical carcinoma in a patient with multiple endocrine neoplasia type 1 (MEN1) and a novel mutation in the MEN1 gene

The incidence of adrenal involvement in MEN1 syndrome has been reported between 9 and 45%, while the incidence of adrenocortical carcinoma (ACC) in MEN1 patients has been reported between 2.6 and 6%. In the literature data only unilateral development of ACCs in MEN1 patients has been reported. We report a 31 years-old female MEN1-patient, in whom hyperplasia of the parathyroid glands, prolactinoma, non functioning pancreatic endocrine carcinoma and functioning bilateral adrenal carcinomas were diagnosed. Interestingly, a not previously described in the literature data, novel germline mutation (p.E45V) in exon 2 of MEN1 gene, was detected. The association of exon 2 mutation of the MEN1 gene with bilateral adrenal carcinomas in MEN1 syndrome, should be further investigated.

From diagnosis to treatment of hepatocellular carcinoma: An epidemic problem for both developed and developing world

Hepatocellular carcinoma (HCC) is the most frequent primary liver malignancy and the third cause of cancer-related death in the Western Countries. The well-established causes of HCC are chronic liver infections such as hepatitis B virus or chronic hepatitis C virus, nonalcoholic fatty liver disease, consumption of aflatoxins and tobacco smocking. Clinical presentation varies widely; patients can be asymptomatic while symptomatology extends from right upper abdominal quadrant paint and weight loss to obstructive jaundice and lethargy. Imaging is the first key and one of the most important aspects at all stages of diagnosis, therapy and follow-up of patients with HCC. The Barcelona Clinic Liver Cancer Staging System remains the most widely classification system used for HCC management guidelines. Up until now, HCC remains a challenge to early diagnose, and treat effectively; treating management is focused on hepatic resection, orthotopic liver transplantation, ablative therapies, chemoembolization and systemic therapies with cytotocix drugs, and targeted agents. This review article describes the current evidence on epidemiology, symptomatology, diagnosis and treatment of hepatocellular carcinoma.

VEGF and Id-1 in pancreatic adenocarcinoma: Prognostic significance and impact on angiogenesis

OBJECTIVES The significance of vascular endothelial growth factor (VEGF) and inhibitor of differentiation/DNA synthesis (Id-1) in tumor neoangiogenesis and tumor progression in pancreatic ductal adenocarcinoma (PDAC) is still unclear. Given the central role of VEGF in cancer angiogenesis and the inconclusive results on Id-1 expression in PDAC, it is of great interest to investigate whether Id-1 and VEGF expression are associated with angiogenesis and prognosis in PDAC. METHODS Paraffin-embedded specimens from 60 consecutive patients with PDAC were immunostained for VEGF, Id-1 and CD34 and staining quantification was assessed by Image analysis system. The correlations among the expression of individual angiogenic factors and microvessel density (MVD), clinicopathologic features and clinical prognosis were analyzed. RESULTS Id-1 and VEGF Positive Activity Indices (PAIs) closely correlated with each other. MVD positively correlated with both Id-1 and VEGF expression. More advanced T and N status correlated with more intense expression of Id-1, VEGF and higher MVD. With regard to prognostic significance higher Id-1 PAI (adjusted HR = 1.69, 95%CI: 1.10-2.59, p = 0.017), higher VEGF PAI (adjusted HR = 2.66, 95%CI: 1.09-6.50, p = 0.032), and MVD (adjusted HR = 1.55, 95%CI: 1.27-1.88, p < 0.001) were associated with poorer survival. CONCLUSIONS VEGF and Id-1 overexpression were found to be associated with high MVD and emerged as adverse prognostic factors in terms of patient survival in PDAC. The potential of selective anti-angiogenic targeting therapy for pancreatic malignancies should prompt further validation of the present findings in studies encompassing larger samples and more elaborate techniques.

Impact of androgen and dietary advanced glycation end products on female rat liver.

Background/Aims: Advanced glycation end products (AGEs) have been related to a wide range of liver disorders including hyperandrogenic states such as the Polycystic Ovary Syndrome (PCOS). The aim of the present study is to evaluate the potential impact of dietary glycotoxins exposure and androgen excess on hepatic histology and biochemistry in an androgenized female rat model. Methods: The study population consisted of 80 female Wistar rats, divided in 3 groups, a group of prepubertal (Group A, n=30) and adult rats (Group B, n=20) that were androgenized via subcutaneous implantation of dihydrotestosterone-containing pellets as well as a group of adult non-androgenized rodents (Group C, n=30). All groups were randomly assigned either to a high-AGE or low-AGE diet for 3 months. Results: Rats fed with a high-AGE diet exhibited significantly elevated levels of gamma-glutamyl transferase (γGT) (p≤0.0002) and indices of AGE immunostaining in liver tissue (p<0.01) when compared to the respective low-AGE group, while aspartate aminotransferase (AST) levels were affected only in non-androgenized animals (p=0.0002). Androgenization per se constitutes an aggravating factor as demonstrated by the elevated γGT levels in adult androgenized animals compared to non-androgenized, independent of diet content (p=0.0002) and by the elevated AST and alanine aminotransferase (ALT) levels in low-AGE subgroups (adult androgenized vs. non-androgenized, p=0.0002) followed by increased immunohistochemical AGE deposition in hepatocytes of the latter categories (p=0.0007). Conclusion: The present study suggests that androgens and glycotoxins may contribute synergistically to distort hepatic physiology and function as observed in hyperandrogenic conditions.

Time of acquisition of HCV infection in renal transplant recipients: a major prognostic factor for disease progression

This study aims to identify crucial factors affecting the evolution of liver disease in HCV‐infected renal transplant recipients.

Immunohistochemical and molecular analysis of PI3K/AKT/mTOR pathway in esophageal carcinoma.

Among the numerous signaling pathways involved in tumorigenesis, PI3K‐AKT‐mTOR is a key one that regulates diverse cellular functions. However, its prognostic value in esophageal carcinoma remains unclear. In our study, we examined the immunohistochemical expression of phosphorylated (p‐) AKT, mTOR, p70S6K and 4E‐BP1 along with the mutational status of PIK3CA and AKT1 genes by High Resolution Melting Analysis and Pyrosequencing in 44 esophageal carcinomas. The results were correlated with the clinicopathological characteristics of the patients in an effort to define their possible prognostic significance. Total p‐mTOR cytoplasmic expression, assessed in 10 random areas, was positively correlated with tumor stage (Kruskal–Wallis ANOVA, I/II vs III/IV, p = 0.0500). Μoreover, maximum p‐mTOR cytoplasmic immunoexpression, estimated in hot spot areas, was positively associated with tumor grade (Mann–Whitney U test, I/II vs III, p = 0.0565). Interestingly, p‐4E‐BP1 immunoreactivity was negatively correlated with tumor histological grade (Mann–Whitney U test, I/II vs III, p = 0.0427). No mutation was observed in exons 9 and 20 of PIK3CA gene and in exon 4 of AKT1 gene. In conclusion, our findings depict the presence of activated PI3K/AKT/mTOR pathway in esophageal cancer bringing forward p‐mTOR and p‐4E‐BP1 for their potential role in esophageal carcinogenesis. Additional studies are warranted to validate our findings.

Cyclin D1, p16INK4A and p27Kip1 in pancreatic adenocarcinoma: assessing prognostic implications through quantitative image analysis

The prognostic significance of cyclin D1, p16INK4A and p27Kip1 expression has been documented in several human malignancies; however, their prognostic potential in pancreatic adenocarcinoma is still unclear. This study aimed to assess the correlation of the aforementioned molecules with clinicopathological parameters and prognosis. Sixty patients with pancreatic ductal adenocarcinoma underwent surgical resection at a single institution; immunohistochemical staining of the studied markers was quantified by Ιmage analysis system. Cyclin D1 overexpression was positively associated with grade, neural infiltration and vascular invasion, whereas p27 positively correlated with age. Higher cyclin D1 expression indicated poorer survival (adjusted HR = 9.75, 95%CI: 1.48–64.31, p = 0.018, increment: one unit in H‐score), whereas a marginal trend toward an association between p16 positivity and improved survival was observed (adjusted HR = 0.58, 95%CI: 0.32–1.05, p = 0.072 regarding positive vs negative cases). No significant association with overall survival was noted regarding p27. In conclusion, cyclin D1 overexpression and possibly p16 loss of expression in pancreatic adenocarcinoma seem to be adverse prognostic factors, whereas p27 expression did not seem to possess such prognostic properties. Further validation of the present findings in studies encompassing larger samples seems to be needed.