Browsing by Author "Kemik, A.S."

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Colon Cancer and Midkine
(Springer Netherlands, 2012) Kemik, O.; Kemik, A.S.; Dülger, A.C.
Midkine, a heparin-binding growth factor, promotes the growth, survival, and migration of various cell populations, and it is over-expressed in many malignant human tumors. Midkine expression is generally increased in colon carcinomas compared to normal colon tissue. Additionally, colon adenomas with medium-to severe-dysplasia exhibit increased midkine expression. Therefore, midkine is expressed during the early stages of colon carcinogenesis and is likely to be involved in the oncogenic process, presumably by promoting tumor cell growth and survival. In the advanced tumor stages, midkine is expected to contribute to tumor progression by promoting tumor angiogenesis. A truncated form of midkine mRNA, which lacks the sequence encoding the N-terminal domain, is expressed in colon cancers in a cancer-specific manner. Detection of this sequence might help to detect micro metastases. Furthermore, the truncated midkine mRNA appears to contribute to colon carcinogenesis because a genetic variant favoring its formation is more frequently found in patients with colon carcinoma compared to unaffected controls. Finally, midkine inhibitors are expected to be valuable in colon cancer treatment; antisense oligo-DNA has been proven to suppress cancer growth in experimental systems. © 2012 Springer Science+Business Media Dordrecht. All rights reserved.
Preoperative Serum Il-6 Levels: Clinical Importance in Gastric Carcinoma With Lymph Node Metastasis
(TIP ARASTIRMALARI DERNEGI, 2010) Kemik, Ö.; Sümer, A.; Kemik, A.S.; Cumhur Dülger, A.; Hasirci, I.; Adaş, M.; Tüzün, S.
Aim: The interleukin-6 (IL-6) pathway is one of the mechanisms that link inflammation and angiogenesis. The purpose of this study was to investigate the preoperative serum levels of IL-6 in gastric carcinoma with lymph node metastasis, and to correlate them with disease status. Method: A total of 100 patients who underwent gastrectomy were enrolled in this study. Serum levels of IL-6 were assessed enzyme linked immunosorbent assay (ELISA). Histological findings included tumor size, depth of tumor invasion, lymph node (LN) metastasis, and TNM stage. Result:Increases in cancer invasion and staging are generally associated with increases in preoperative serum IL-6 levels. IL-6 levels were correlated with invasion depth (p<0.001), LN metastasis (p<0.001), and TNM stage. The presence of peritoneal seeding metastasis is associated with IL-6 levels (p<0.001). Conclusion: Preoperative serum IL-6 levels might be markers of tumor invasion, LN metastasis, and TNM stage. These results suggest that IL-6 levels are potential molecular markers that predict lymphatic involvement in gastric carcinoma.
Relationship Between Clinicopathologic Variables and Serum and Tissue Levels of Dickkopf-1 in Patients With Rectal Cancer
(BMJ Publishing Group, 2011) Kemik, O.; Kemik, A.S.; Sumer, A.; Begenik, H.; Purisa, S.; Tuzun, S.; Kotan, C.
The major biomarker for rectal cancer is the pathologic development of the tumor. In our study, we identified Dikkopf-1 (DKK1) as a novel biomarker and a therapeutic target for rectal cancer. To emphasize the biological and clinicopathologic significance, we performed tumor tissue and serum analysis of 150 rectal cancer samples with enzymelinked immunosorbent assay. Serum DKK-1 levels are found significantly higher in controls, in poor differentiation, and depth of invasion (in pT3 and pT4), present lymph node metastasis, and TNM stage (in pT3 and pT4) according to good differentiation, depth of invasion (in pT1 and pT2), absent lymph node metastasis, and TNM stage (in pT1 and pT2; P < 0.001 and P < 0.0001, respectively). Tissue DKK-1 levels are found in patients with rectal cancer than in control tissues (P < 0.0001). Dikkopf-1 correlated significantly with depth of invasion (P = 0.009), lymph node metastasis (P = 0.028), venous involvement (P = 0.019), and advanced pTNM stage (P = 0.001). There was no correlation between DKK-1 and age or sex (P > 0.05). This marker is also a potential candidate for development of rectal cancer cells and cancer progression. Copyright © 2011 by The American Federation for Medical Research.
Serum Level of Soluble Vascular Adhesion Molecule 1 in Patients With Rectal Cancer
(TIP ARASTIRMALARI DERNEGI, 2011) Kemik, O.; Kemik, A.S.; Hasirci, I.; Adaş, M.; Purisa, S.; Dülger, A.C.; Tüzün, S.
Aim: Vascular adhesion molecule 1 (VCAM-1) plays an important role in solid tumor enlargement and/or metastases. This study evaluated the clinical significance of measuring serum levels of soluble VCAM-1 in rectal cancer and aimed to clarify the biologic significance of its local expression. Method: Serum was collected from 90 patients with rectal cancer and 40 healthy volunteers. Cancer tissue was collected from 84 patients. The level of soluble VCAM-1 in serum and cancer tissue was measured enzyme linked immunosorbent assay.Result: The mean soluble VCAM-1 level in patients was significantly higher than that in control subjects. Elevated serum soluble VCAM-1 was significantly associated with clinicopathologic paramaters such as tumor size, lymph node metastasis, distant metastasis, and poor prognosis. The prognosis for stage 2 patients positive for soluble VCAM-1 level was comparable to that for stage 3 patients. In addition, the serum level of soluble VCAM-1 level was not found correlation with the cancer tissue level. Conclusion: The preoperative level of soluble VCAM-1 level reflected disease progression and was a sensitive biomarker for rectal cancer.
Serum Thymidine Kinase Is Associated With Gastric Adenocarcinoma
(2011) Kemik, O.; Kemik, A.S.; Purisa, S.; Tuzun, S.
Thymidine kinase (TK) plays an essential role in the processing of thymidine within the cell and therefore it is an important marker of proliferation, particularly in tumor cells. The aim of our study was to determine the diagnostic and prognostic importance of TK measurement in gastric adenocarcinoma. The serum level of TK was measured in 72 patients with gastric adenocarcinoma. Serum levels of TK were significantly elevated in gastric adenocarcinoma in comparison with healthy individuals. Also, we have found that there are significant variations in TK serum concentrations when measured that correlate with important variations in clinico-pathological features and prognostic significance.
Transforming Growth Factor Beta-1 in Human Colorectal Cancer Patients
(TIP ARASTIRMALARI DERNEGI, 2011) Kemik, O.; Kemik, A.S.; Purisa, S.; Hasirci, I.; Dülger, A.C.; Adaş, M.; Tüzün, S.
Aim: Colorectal cancer patients are treated with surgery and sometimes radiotherapy and chemotherapy. Transforming growth factor beta-1 (TGF-β1) acts both as an inhibitor of tumor growth and as a promoter of tumor progression. The aim of this study was to determine the levels of TGF-β1 in plasma in colorectal cancer patients and relate these to the effect of clinicopathological variables. Method: One hundred patients scheduled for colorectal cancer surgery were included. Blood samples were taken during surgery and later assayed with enzyme linked immunsorbent assay for total TGF-β1 and active TGF-β1. Result: Total and active TGF-β1 was higher in tumor samples compared to controls (p<0.001).Total TGF-β1 was higher in patients with metastases compared to patients without. Active TGF-β1 levels were not found statistically different in patients with metastases. Conclusion: Higher levels of total TGF-β1 in plasma at surgery may be indicate of distant metastases, Measurement of total TGF-β1 in colorectal cancer patients may be of clinical use in the future.