Ozgul Sagol

Differential expression of Caveolin-1 in hepatocellular carcinoma: correlation with differentiation state, motility and invasion

BackgroundCaveolin-1 is the main component of caveolae membrane structures and has different roles during tumorigenesis in different cancer types with varying expression profiles, indicating that the role of caveolin-1 varies according to tumor type. In this study, we investigated the role and expression of caveolin-1 in hepatocellular carcinogenesis.MethodsWe analyzed the expression of Caveolin-1 in 96 hepatocellular carcinoma (HCC), 29 cirrhosis, 20 normal liver tissues and 9 HCC cell lines by immunostaining and western blotting, respectively. After caveolin-1 was stably transfected to HepG2 and Huh7 cells, the effects of Caveolin-1 on the cellular motility, matrix invasion and anchorage-independent growth were studied. Also, caveolae structure was disrupted in endogenously caveolin expressing cells, SNU 449 and SNU 475 by addition of methyl-β-cyclodextrin and analyzed cellular motility and invasion.ResultsIn HCC cell lines, Caveolin-1 expression is correlated to differentiation and basal motility status of these cells. The percentage of Caveolin-1 positivity was found extremely low in normal liver tissue (5%) while it was increased in cirrhosis (45%) and in HCC (66%) (p = 0.002 and p = 0.001 respectively). Cav-1 expression in poorly differentiated HCC samples has been found significantly higher than well differentiated ones (p = 0.001). The caveolin-1 expression was found significantly higher in tumor cells than its peritumoral cirrhotic tissues in HCC samples (p < 0.001). Additionally, the patients with positive staining for Caveolin-1 had significantly higher portal vein invasion than those with negative staining (p = 0.02). Caveolin-1 overexpression increased motility and invasion of HepG2 and Huh7 cells. And disruption of caveolae results in a dramatic decline in both motility and invasion abilities in SNU-449 and SNU-475 cells. Furthermore, caveolin-1 overexpression resulted in down-regulation of E-cadherin while up-regulation of Vimentin. Also, it increased secreted MMP-2 and expression levels of MMP-9 and MT1-MMP. There was no significant difference in colony formation in soft agar between stable clones and parental ones.ConclusionIn conclusion, stepwise increase in Cav-1 expression in neoplastic stage with respect to pre-neoplastic stage during hepatocellular carcinogenesis and its ability to stimulate HCC cell motility and invasiveness indicate that this protein plays a crucial role in tumor progression.

The protective effects of carnosine and melatonin in ischemia-reperfusion injury in the rat liver.

The reperfusion following liver ischemia results in hepatocyte damage and apoptosis. The aim of this study was to investigate the effects of two antioxidant agents, carnosine and melatonin, in rat liver ischemia-reperfusion injury. Five study groups were formed; I. sham, II. ischemia-reperfusion, III. ischemia-reperfusion+melatonin, IV. ischemia-reperfusion+carnosine, V. ischemia-reperfusion+melatonin+carnosine. Then 250 mg/kg carnosine and 10 mg/kg melatonin were administered intraperitoneally 30 min before ischemia and immediately after the reperfusion. Sinusoidal dilatation, congestion and neutrophil infiltration were observed in the ischemia-reperfusion group while these symptoms were less pronounced in the treatment groups. Alanine aminotransferase, aspartate aminotransferase and myeloperoxidase levels were increased in the ischemia-reperfusion group while they were lowered in the treatment groups. Glutathione level was low in the ischemia-reperfusion group while it tended to increase in the ischemia-reperfusion+carnosine administered and ischemia-reperfusion+carnosine+melatonin administered groups. There was an increase in the number of apoptotic cells in the ischemia-reperfusion group while this number was lowered in the treatment groups. Carnosine was more effective than melatonin in the reversal of structural and biochemical alterations that resulted from ischemia-reperfusion injury. The administration of melatonin and carnosine together yielded better outcomes compared to the sole administration of each agent.

Immunohistochemical detection of pS2 protein and heat shock protein-70 in pancreatic adenocarcinomas. Relationship with disease extent and patient survival.

We investigated pS2 and HSP-70 protein expression in 36 pancreatic adenocarcinomas for their effect on disease extent and patient outcome. The cases were reviewed, histologically diagnosed, typed, graded, and staged. Lymphatic vessel, blood vessel and perineural invasion as well as lymph node, resection margin and adjacent organ involvements were re-evaluated. The standard streptavidin biotin immunperoxidase method was used for immunostaining with pS2 and HSP-70 antibodies. Cytoplasmic staining with both antibodies was scored semiquantitatively. The scores were compared with histopathological prognostic parameters using statistical methods. Standard prognostic parameters and staining scores were tested by survival analysis in terms of their effect on survival. All the tumors showed a positive cytoplasmic reaction with HSP-70 antibody. Seventy-seven percent of the tumors showed positive cytoplasmic staining with pS2 antibody (22.2% +, 13.9% ++ and 41.7% +++). There was a statistically significant difference between HSP-70 staining scores with N status and final stages of the tumors (Chi-square, p = 0.03 and p = 0.026, respectively), while neither direct nor inverse correlation was detected for both parameters. PS2 staining scores showed no statistically significant relationship with tumor grade T, M status, perineural invasion, lymph and blood vessel invasion. In tumors with extensive staining with pS2, tumor stage tended to be low (Chi square, p = 0.024, Kendall Tau-b, r: -0.336, p = 0.036). There was a statistically significant difference and inverse correlation between tumors with extensive pS2 staining and tumors with less intense staining in terms of lymph node metastasis (Chi-square, p = 0.041, Kendall Tau: p = 0.024, r = -0,373). In the R0 resection group, in univariate analysis, we found that with higher scores of HSP-70 staining, the prognosis of the patient tended to improve. (Cox regression, p = 0.013). In multivariate analysis, HSP-70 expression was found to be an independent prognostic factor. We found no relationship between pS2 staining and patient survival.

Cooperative interaction of MUC1 with the HGF/c-Met pathway during hepatocarcinogenesis.

BackgroundHepatocyte growth factor (HGF) induced c-Met activation is known as the main stimulus for hepatocyte proliferation and is essential for liver development and regeneration. Activation of HGF/c-Met signaling has been correlated with aggressive phenotype and poor prognosis in hepatocellular carcinoma (HCC). MUC1 is a transmembrane mucin, whose over-expression is reported in most cancers. Many of the oncogenic effects of MUC1 are believed to occur through the interaction of MUC1 with signaling molecules. To clarify the role of MUC1 in HGF/c-Met signaling, we determined whether MUC1 and c-Met interact cooperatively and what their role(s) is in hepatocarcinogenesis.ResultsMUC1 and c-Met over-expression levels were determined in highly motile and invasive, mesenchymal-like HCC cell lines, and in serial sections of cirrhotic and HCC tissues, and these levels were compared to those in normal liver tissues. Co-expression of both c-Met and MUC1 was found to be associated with the differentiation status of HCC. We further demonstrated an interaction between c-Met and MUC1 in HCC cells. HGF-induced c-Met phosphorylation decreased this interaction, and down-regulated MUC1 expression. Inhibition of c-Met activation restored HGF-mediated MUC1 down-regulation, and decreased the migratory and invasive abilities of HCC cells via inhibition of β-catenin activation and c-Myc expression. In contrast, siRNA silencing of MUC1 increased HGF-induced c-Met activation and HGF-induced cell motility and invasion.ConclusionsThese findings indicate that the crosstalk between MUC1 and c-Met in HCC could provide an advantage for invasion to HCC cells through the β-catenin/c-Myc pathway. Thus, MUC1 and c-Met could serve as potential therapeutic targets in HCC.

Expression of transforming growth factor-beta-1 and p27Kip1 in pancreatic adenocarcinomas: relation with cell-cycle-associated proteins and clinicopathologic characteristics

BackgroundThe purpose of our study was to investigate the immunohistochemical expression of TGF-β1 and p27 in pancreatic adenocarcinomas and to compare the findings with the clinicopathological features and survival. We also aimed to evaluate the expression of TGF-β1 and p27 in the context of other cell cycle and proliferation markers such as cyclin D1 and Ki-67.MethodsWe examined TGF-β1 and p27 expression immunohistochemically in 63 cases of invasive ductal adenocarcinoma of the pancreas. Standard streptavidin-biotin immunperoxidase method was used for immunostaining and the stained slides were examined microscopically using semiquantitative criteria.ResultsTGF-β1 stained the cytoplasms of the tumor cells in 43 cases [68.3%]. There was a statistically significant difference among TGF-β1 staining scores in terms of clinicopathologic factors such as blood vessel invasion, stage and distant metastasis [p < 0.05]. Of the 63 tumors evaluated 23 [36.5%] were positive for p27 within the nucleus. An inverse correlation was found between p27 immunoreactivity and grade [p < 0.05]. But no significant correlation was found between p27 and other parameters. Among the patients with survival data 27 patients had RO resections and these cases were considered in survival analysis. In the univariate analysis, neither TGF-β1 nor p27 expression was related with patient survival.ConclusionOur findings suggest that in pancreatic carcinoma, TGF-β1 expression is related to tumor growth and metastasis. But it is not associated with cell cycle proteins. p27 expression is reduced in pancreatic adenocarcinomas and decreased protein levels of p27 may play a role in the differentiation of pancreatic cancer.

Survivin, p53, and Ki-67 as predictors of histopathologic response in locally advanced rectal cancer treated with preoperative chemoradiotherapy

PurposeThe ability to predict response to chemoradiotherapy before the treatment may allow protecting poorly responding patients from the side effects of neoadjuvant treatment. Several molecular markers have been proposed to radio and chemosensitivity of rectal cancer. In this study, from pre-irradiation tumor biopsies, a novel and promising candidate factor survivin, and p53 and Ki-67 were assessed as predictors of response to preoperative chemoradiotherapy.Materials and methodsExpression of each marker was evaluated by immunohistochemistry on pretreatment biopsies from 37 patients having rectal cancer treated with preoperative chemoradiotherapy and curative surgery. Treatment response was assessed histopathologically in the resected surgical specimen.ResultsThere was no correlation between expression of p53, Ki-67, and survivin with response to preoperative chemoradiotherapy and prognosis.ConclusionsOur data suggest that these molecular markers are not helpful to identify patients who would have benefit from neoadjuvant treatment of rectal cancer. Further investigations are necessary to select patients for preoperative treatment based on analysis of the preoperative biopsies.

Genome-Wide Transcriptional Reorganization Associated with Senescence-to-Immortality Switch during Human Hepatocellular Carcinogenesis

Senescence is a permanent proliferation arrest in response to cell stress such as DNA damage. It contributes strongly to tissue aging and serves as a major barrier against tumor development. Most tumor cells are believed to bypass the senescence barrier (become “immortal”) by inactivating growth control genes such as TP53 and CDKN2A. They also reactivate telomerase reverse transcriptase. Senescence-to-immortality transition is accompanied by major phenotypic and biochemical changes mediated by genome-wide transcriptional modifications. This appears to happen during hepatocellular carcinoma (HCC) development in patients with liver cirrhosis, however, the accompanying transcriptional changes are virtually unknown. We investigated genome-wide transcriptional changes related to the senescence-to-immortality switch during hepatocellular carcinogenesis. Initially, we performed transcriptome analysis of senescent and immortal clones of Huh7 HCC cell line, and identified genes with significant differential expression to establish a senescence-related gene list. Through the analysis of senescence-related gene expression in different liver tissues we showed that cirrhosis and HCC display expression patterns compatible with senescent and immortal phenotypes, respectively; dysplasia being a transitional state. Gene set enrichment analysis revealed that cirrhosis/senescence-associated genes were preferentially expressed in non-tumor tissues, less malignant tumors, and differentiated or senescent cells. In contrast, HCC/immortality genes were up-regulated in tumor tissues, or more malignant tumors and progenitor cells. In HCC tumors and immortal cells genes involved in DNA repair, cell cycle, telomere extension and branched chain amino acid metabolism were up-regulated, whereas genes involved in cell signaling, as well as in drug, lipid, retinoid and glycolytic metabolism were down-regulated. Based on these distinctive gene expression features we developed a 15-gene hepatocellular immortality signature test that discriminated HCC from cirrhosis with high accuracy. Our findings demonstrate that senescence bypass plays a central role in hepatocellular carcinogenesis engendering systematic changes in the transcription of genes regulating DNA repair, proliferation, differentiation and metabolism.

Does angiogenesis predict recurrence in superficial transitional cell carcinoma of the bladder

OBJECTIVES To investigate the role of angiogenesis in predicting tumor recurrence and its correlation with established clinicopathologic prognostic factors in superficial transitional cell carcinoma of the bladder. METHODS The paraffin sections of 80 superficial papillary transitional cell bladder carcinoma specimens were stained with CD31 antibody to label the vascular endothelium using the standard streptavidin-biotin-immunoperoxidase method. The vascular surface density (VSD) equivalent to the vascular surface area per unit of tissue volume and number of vessels per square millimeter of stroma (NVES) were assessed by means of stereology, and these morphometric parameters of angiogenesis were statistically analyzed to interpret the relation to tumor recurrence in addition to tumor stage, grade, size, and number and the presence of carcinoma in situ. RESULTS VSD and NVES values showed no statistically significant difference between pTa and pT1 tumors or patients with and without recurrence. In contrast, VSD and NVES values were found to increase in higher grade tumors (P = 0.019). VSD values were also higher in patients with coexisting carcinoma in situ in pTa tumors (P <0.001). Tumor number and size and recurrence number and time to the first recurrence did not correlate with any vascular parameters. CONCLUSIONS Stereologic assessment of angiogenesis does not help to predict recurrence in superficial bladder cancer. Angiogenic parameters appeared to be well correlated with the conventional histologic grading system. Otherwise, the present study did not show any correlation of angiogenesis with any potential prognostic factors. This may be due to the diverse angiogenic pathways occurring in invasive and superficial tumors.

Gastrointestinal stromal tumor of the stomach with lymph node metastasis

BackgroundLymph node (LN) metastasis of gastrointestinal stromal tumors (GIST) is unusual. Unlike gastric adenocarcinomas, routine lymphadenectomy is not recommended unless there is no suspicion for LN metastasis. Herein, we report a case of GIST of the stomach with LN metastasis treated with distal gastrectomy with perigastric LN dissection followed by adjuvant imatinib therapy.Case presentationA 32-year-old female presented with anemia. Diagnostic investigations including thoracoabdominopelvic computed tomography (CT) scan and gastroscopy revealed a 8 cm gastric antral submucosal tumor without any metastasis. Enlarged periantral LNs were detected during laparotomy and patient underwent distal gastrectomy with en bloc perigastric LN dissection. Pathologic investigation revealed antral stromal tumor with high mitotic and Ki-67 index. Lymph node metastasis was observed in 7 of 12 resected perigastirc nodes. Immunohistochemically, tumor cells were positive for CD117. She was diagnosed as high grade gastric GIST due to the presence of LN metastasis, large tumor size and unfavorable histopathologic features thus underwent adjuvant imatinib treatment (400 mg, daily). No recurrence or metastasis has been detected during a 12-month of postoperative follow-up.ConclusionSurgery remains the mainstay of treatment in patients with localized, resectable GISTs. Although lymphatic metastasis rarely occurs in patients with GIST, LN dissection should be considered for patients with any suspicion of nodal metastasis. Adjuvant imatinib treatment is recommended according to the well defined prognostic factors.

Primary Non-Hodgkin's T-Cell Lymphoma of the Thyroid Gland Complicating Hashimoto's Thyroiditis: Case Report

This case report presents an extremely rare case of primary non-Hodgkins T-cell lymphoma of the thyroid gland complicating Hashimotos thyroiditis and discusses the clinical history, findings, treatment, and prognosis. Although the place of surgery in the treatment of thyroid lymphoma is controversial, in this case, surgery followed by three rounds of chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone, and radiation therapy to neck and mediastinum were a very effective treatment for the disease so that no relapse has been detected during 3-year follow-up.