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Dive into the research topics where Mehmet Emin Kalender is active.

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Featured researches published by Mehmet Emin Kalender.


Oncology Research | 2009

Association between the Thr431Asn polymorphism of the ROCK2 gene and risk of developing metastases of breast cancer.

Mehmet Emin Kalender; Seniz Demiryürek; Serdar Oztuzcu; Ayşe Kizilyer; Abdullah T. Demiryürek; Alper Sevinc; Mustafa Dikilitas; Ramazan Yildiz; Celalettin Camci

The objective of this study was to analyze the genotype distributions and allele frequencies for ROCK2 Thr431Asn and Arg83Lys polymorphisms among breast cancer patients. In this case-control study, 223 patients with breast cancer were recruited and divided into two groups according to metastases (n = 128) and without metastases (n = 95). Genomic DNA from the patients and the control cases (n = 150) was analyzed by real-time PCR using a Light-Cycler. Neither genotype distributions nor the allele frequencies for the Arg83Lys polymorphism showed a significant difference between the groups. Although no marked changes were observed with nonmetastatic group, a statistically significant association was found between the control and metastatic group for the Thr431Asn polymorphism. Although homozygous carriers of the Thr431Thr genotype were more frequent, heterozygous carriers of the Thr431Asn genotype were less frequent among the metastatic patients than among controls. There was also an increase in Thr431 allele (60.5% in patients vs. 51.7% in controls) and decrease in Asn431 allele frequencies (48.3% in control vs. 39.5% in metastatic patients) in metastatic groups (p = 0.036). Our results demonstrate that Thr431Asn polymorphism of the ROCK2 gene could be a risk factor for the metastases of the breast cancer, and may help in predicting the prognosis.


Cancer Chemotherapy and Pharmacology | 2009

Detection of complete response to imatinib mesylate (Glivec ® /Gleevec ® ) with 18F-FDG PET/CT for low-grade endometrial stromal sarcoma

Mehmet Emin Kalender; Alper Sevinc; Mustafa Yilmaz; Coşkun Özsaraç; Celalettin Camci

Malignant mesenchymal tumors consist of approximately 10% of uterine tumors. The majority of uterine sarcomas are leiomyosarcoma and endometrial stromal sarcoma (ESS). Surgery, radiotherapy, chemotherapy, and hormonal therapy are used for the treatment of ESS. Imatinib mesylate is indicated in the management of gastrointestinal stromal tumor and chronic myelogeneus leukemia. There is an interest to use imatinib mesylate in the treatment of c-kit positive ESS. We reported a case of 42-year-old female low-grade ESS progressed on chemotherapy and presented with objective response to imatinib mesylate. The treatment response was evaluated with FDG PET/CT. Complete metabolic response was detected. FDG PET, a sensitive method for tumor response evaluation on the basis of tumor metabolism changes, is useful for the evaluation of imatinib treatment in low-grade ESS.


Pain Medicine | 2010

Leech Therapy for Symptomatic Relief of Cancer Pain

Mehmet Emin Kalender; Gazi Comez; Alper Sevinc; Ahmet Dirier; Celalettin Camci

OBJECTIVE Most patients with advanced stage cancer report moderate to severe pain. The leech (Hirudo medicinalis) is commonly used in traditional medicine for relief of localized pain. DESIGN We report a case of severe pain related to advanced stage cancer successfully treated by self-applied leeches. SETTING AND PATIENTS A 62-year-old male patient with synchronous renal cell carcinoma and leiomyosarcoma was admitted with severe pain in the lumbar region. The pain was refractory to radiotherapy, and systemic and epidural analgesic infusion. RESULTS Two months the patient came to the clinic in good condition free of pain. The patient reported outpatient self-treatment with seven leeches to the lumbar region in the interim that resulted in complete healing of pain. CONCLUSIONS This is the first report indicating possible activity of leeches in cancer pain.


Tumor Biology | 2013

Correlation between Rho-kinase pathway gene expressions and development and progression of glioblastoma multiforme.

Ibrahim Erkutlu; Ahmet Cigiloglu; Mehmet Emin Kalender; Mehmet Alptekin; A. Tuncay Demiryurek; Ali Suner; Esma Ozkaya; Mustafa Ulasli; Celalettin Camci

Glioblastoma multiforme (GBM) is the most common and the most aggressive primary malignant tumor of the brain. Prognostic factors in GBM can be sorted as age, tumor localization, tumor diameter, symptom period and type, the extent of surgery, postoperative tumor volume, and adjuvant radiotherapy and/or chemotherapy status. Besides the interactions between actin microfilaments, microtubules, and intermediate filaments, environmental factors and intracellular signals which regulate them affect the cell invasion. Rho proteins and therefore Rho-kinase activation play important role at these changes. The aim of this study is to evaluate the relationship between the Rho-kinase pathway gene expressions and prognosis in GBM. Ninety-eight patients diagnosed as GBM between 2001 and 2010 were enrolled into the study. RNA was obtained from the paraffinized tumor tissue of the patients with formalin-fixed, paraffin-embedded RNA isolation kit and the mRNA expressions of 26 genes were investigated. There was a statistically significant negative correlation between the ages at the diagnosis and survival. There was a significant relationship between the overexpression of Rho-kinase pathway-related genes LIMK1, CFL1, CFL2, and BCL2 and low expression of MAPK1 gene and the survival of the patients. These results demonstrate for the first time that there is a marked contribution of Rho-kinase pathway-related genes to the progression and survival of the GBM. The expression of these genes may be related to response of multimodal therapy or these parameters could be used to determine possible unresponsive patients before treatment.


Tumor Biology | 2010

CDC25A gene 263C/T, -350C/T, and -51C/G polymorphisms in breast carcinoma

Isik Didem Karagoz; Mehmet Ozaslan; Beyhan Cengiz; Mehmet Emin Kalender; Ibrahim Halil Kilic; Serdar Oztuzcu; Bulent Gogebakan; Abdullah T. Demiryürek

The family of cell division cycle 25 (CDC25) phosphatase is one of the important regulators of the cell cycle progression. In mammalian cells, three isoforms have been identified: CDC25A, CDC25B, and CDC25C. CDC25A is required to enter S time, and the overexpression of this phosphatase accelerates the entrance to S time. CDC25A overexpression could render tumor cells less sensitive to DNA replication checkpoints, thereby contributing to their genomic instability. We aimed to investigate, for the first time, the frequency of human CDC25A gene SNPs in metastatic and non-metastatic breast cancer. Total number of 281 eligible patients with histologically confirmed incident of breast cancer and 137 cancer-free controls were included. The detection of CDC25A gene polymorphisms was achieved with real-time polymerase chain reaction and restriction fragment length polymorphism techniques. We found that the 263C/T polymorphism was significantly associated with breast cancer and risk of metastasis. The -350C/T polymorphism in the promoter region of CDC25A gene was found to associate with neither breast cancer nor metastasis. The other promoter polymorphism -51C/G in the CDC25A gene associated with breast cancer but not associated with metastasis. These data suggest that 263C/T and -51C/G polymorphisms of CDC25A gene could be candidate markers for earlier diagnosis and targets for breast cancer therapy.


Tumor Biology | 2011

Peripheral blood guanylyl cyclase c (GCC) expressions are associated with prognostic parameters and response to therapy in colorectal cancer patients

Celalettin Camci; Akif Şahin; Alper Sevinc; Mehmet Emin Kalender; Serdar Oztuzcu; Ozlem Nuray Sever; Esma Ozkara; Abdullah T. Demiryürek

Guanylyl cyclase C (GCC) is expressed exclusively in normal intestinal mucosal cells, primary and metastatic colorectal cancers (CRC). The aim of this study was to determine the possible association between the GCC expressions in peripheral blood, prognostic parameters and response to chemotherapy in CRC patients. Fourty-nine metastatic CRC patients and 41 healthy controls with similar age and sex were included to this study. Peripheral blood GCC expressions are measured by the reverse transcriptase-polymerase chain reaction (RT-PCR) method. Interstingly, no GCC expression was measured in healthy controls but GCC expressions of the patients were detectable. Although there was a significant reduction in GCC expressions in 30 patients with regression (from 5.46 ± 4.12 to 0.06 ± 0.03, p < 0.0001), marked increase in GCC expressions was observed in 19 patients with progression following chemotherapy (from 0.43 ± 0.19 to 1.38 ± 0.52, p = 0.0174). Significant correlation was found between the GCC expressions and carbohydrate antigen 19–9 (CA19-9) levels (p = 0.0041) in 30 patients with regression before chemotherapy. Marked correlation was also detected between the GCC expressions and carcinoembryonic antigen (CEA) levels (p = 0.0072) in 19 patients with progression before chemotherapy. The results of the present study suggest that peripheral blood GCC expressions along with CEA and CA19-9 can be used to determine the early respose to chemotherapy in patients with metastatic CRC. These findings imply that higher expression of GCC in peripheral blood seems to be an indicator of good therapeutic response to chemotherapy and remission. Monitoring the peripheral blood GCC expressions may allow employing different treatment options to metastatic CRC patients.


OncoTargets and Therapy | 2016

Polymorphism of CYP3A4 and ABCB1 genes increase the risk of neuropathy in breast cancer patients treated with paclitaxel and docetaxel

Tulay Kus; Gokmen Aktas; Mehmet Emin Kalender; Abdullah T. Demiryürek; Mustafa Ulasli; Serdar Oztuzcu; Alper Sevinc; Seval Kul; Celaletdin Camci

Background Interindividual variability of pharmacogenetics may account for unpredictable neurotoxicities of taxanes. Methods From March 2011 to June 2015, female patients with operable breast cancer who had received docetaxel- or paclitaxel-containing adjuvant chemotherapy were included in this study. All patients were treated with single-agent paclitaxel intravenously (IV) 175 mg/m2 every 3 weeks for four cycles, or IV 80 mg/m2 weekly for 12 cycles, and IV 100 mg/m2 docetaxel for four cycles as adjuvant treatment. We evaluated the relationship between neurotoxicity of taxanes and single-nucleotide polymorphisms of ABCB1, CYP3A4, ERCC1, ERCC2, FGFR4, TP53, ERBB2, and CYP2C8 genes. Taxane-induced neurotoxicity during the treatment was evaluated according to the National Cancer Institute Common Toxicity Criteria version 4.03 prior to each cycle. Chi-squared tests were used to compare the two groups, and multivariate binary logistic regression models were used for determining possible risk factors of neuropathy. Results Pharmacogenetic analysis was performed in 219 females. ABCB1 3435 TT genotype had significantly higher risk for grade ≥2 neurotoxicity (odds ratio [OR]: 2.759, 95% confidence interval [CI]: 1.172–6.493, P: 0.017) compared to TC and CC genotype, and also CYP3A4 392 AA and AG genotype had significantly higher risk for grade ≥2 neurotoxicity (OR: 2.259, 95% CI: 1.033–4.941, P: 0.038) compared to GG genotype. For FDGF4 gene with AG and GG genotype, OR was 1.879 (95% CI: 1.001–3.525, P: 0.048) compared to AA genotype with regard to any grade of neuropathy risk. We could not find any other association of other genotypes with neurotoxicity grades. Conclusion ABCB1 3435 TT genotype and CYP3A4 392 AA/AG genotypes may be used as predictors of neurotoxicity during taxane chemotherapy.


Gene | 2016

High-throughput screening of Sirtuin family of genes in breast cancer.

Mehri Igci; Mehmet Emin Kalender; Ersin Borazan; Ibrahim Bozgeyik; Recep Bayraktar; Esra Bozgeyik; Celaletdin Camci; Ahmet Arslan

Mammalian Sirtuins have been shown to perform distinct cellular functions and deregulated expression of these genes was reported to be involved in the development of various malignancies including breast cancer. An increasing number of evidence indicates that Sirtuins have both tumor promoter and tumor suppressor functions. However, the roles of Sirtuins have not been well-reported in breast cancer. In the present study, quantitative expression levels of Sirtuins (SIRT1-7) in breast cancer patients and breast cancer cell lines (MCF-7 and SKBR3) and control cell line (CRL-4010) were assessed by using a high-throughput real-time PCR method. As a result, Sirtuins were found to be differentially expressed in breast cancer tissues and cancer cell lines. Particularly, expressions of SIRT1 and SIRT4 were found to be significantly down-regulated in breast cancer tissues and SKBR3 breast cancer cells. In contrast, SIRT2, SIRT3, and SIRT5 genes were shown to be up-regulated in our study. Although SIRT6 and SIRT7 were also up-regulated in breast cancer tissues, these expression changes were statistically insignificant. Additionally, SIRT2, SIRT3, SIRT5, SIRT6 and SIRT7 were found to be differentially expressed in breast cancer cell lines. Yet, these changes were not well-correlated with tissue expression levels. In conclusion, Sirtuin family of genes shows differential expressions in breast cancer tissues and cells and SIRT1 and SIRT4 seem to play key tumor suppressor roles in breast cancer development. Herein, we report expression levels of Sirtuin family of genes in both breast cancer tissues and cancer cell lines simultaneously.


Medical Science Monitor | 2014

The Relationship between Urotensin II and its Receptor and the Clinicopathological Parameters of Breast Cancer

Ozan Balakan; Mehmet Emin Kalender; Ali Suner; Beyhan Cengiz; Serdar Oztuzcu; Recep Bayraktar; Ersin Borazan; Taner Babacan; Celaletdin Camci

Background Urotensin II is a vasoactive polypeptide. It is known that some vasoactive polypeptides are produced and secreted by tumor cells, and act as a paracrine growth stimulant. The aim of this study was to examine the relationship between urotensin II and its receptor’s messenger RNA expression in breast cancer. Material/Methods Fifty-nine women with breast cancer were included in this study. The median age was 48 years. The relationships between urotensin II and urotensin II receptor mRNA expressions, which were derived from fresh breast cancer tissues and adjacent normal breast tissues, and clinical and pathological parameters, were assessed. Results We found expressions of urotensin II mRNA and its receptor in 55 of 59 breast cancer tissues and in 55 of 59 normal breast tissues. We found a positive significant correlation between urotensin II and its receptor (p=0.001, r=0.632), and found a negative, but insignificant, correlation between urotensin II and age (p=0.038, r=−0.281). Urotensin II levels were higher in the premenopausal group compared to the postmenopausal group (p<0.05). The mean urotensin II receptor expression was higher in the premenopausal group (p<0.05) compared to the postmenopausal group, and its expression was also higher in the group without extra-nodal invasion compared to that of the group with extra-nodal invasion (p=0.001). Urotensin II levels were higher in the group without lymphatic invasion compared to the group with lymphatic invasion (p=0.048). Conclusions This study is the first in the English medical literature to determine the urotensin II and its receptor mRNA expressions in breast cancer tissues. Consequently, urotensin II seems be associated with menopausal status, and extra-nodal and lymphatic invasion.


Clinical and Applied Thrombosis-Hemostasis | 2007

Thrombotic thrombocytopenic purpura and bone marrow necrosis as the initial presentation of lung cancer.

Alper Sevinc; Mehmet Emin Kalender; Yavuz Pehlivan; Ibrahim Sari; Celalettin Camci

Thrombotic thrombocytopenic purpura (TTP) is a disseminated form of thrombotic microangiopathy. Although most cases are held to be idiopathic, its association with malignancy is well recognized, and it usually occurs at the terminal stage of cancer. Bone marrow necrosis (BMN) is another rare disorder defined pathologically as the necrosis of myeloid tissue and medullary stroma with preservation of bone. Although hematologic malignancy is the most common underlying disease associated with BMN, it can also be caused by solid tumors. The occurrence of TTP with BMN associated with lung cancer has not been reported in the English literature. First described is a patient with the rare association of TTP and BMN displayed as the first manifestations of a lung cancer.

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Alper Sevinc

University of Gaziantep

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Ali Suner

University of Gaziantep

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Gokmen Aktas

University of Gaziantep

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Tulay Kus

University of Gaziantep

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Ozan Balakan

University of Gaziantep

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