Cigdem Aydin

Surface TRAIL decoy receptor-4 expression is correlated with TRAIL resistance in MCF7 breast cancer cells

BackgroundTumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) selectively induces apoptosis in cancer cells but not in normal cells. Despite this promising feature, TRAIL resistance observed in cancer cells seriously challenged the use of TRAIL as a death ligand in gene therapy. The current dispute concerns whether or not TRAIL receptor expression pattern is the primary determinant of TRAIL sensitivity in cancer cells. This study investigates TRAIL receptor expression pattern and its connection to TRAIL resistance in breast cancer cells. In addition, a DcR2 siRNA approach and a complementary gene therapy modality involving IKK inhibition (AdIKKβKA) were also tested to verify if these approaches could sensitize MCF7 breast cancer cells to adenovirus delivery of TRAIL (Ad5hTRAIL).MethodsTRAIL sensitivity assays were conducted using Molecular Probes Live/Dead Cellular Viability/Cytotoxicity Kit following the infection of breast cancer cells with Ad5hTRAIL. The molecular mechanism of TRAIL induced cell death under the setting of IKK inhibition was revealed by Annexin V binding. Novel quantitative Real Time RT-PCR and flow cytometry analysis were performed to disclose TRAIL receptor composition in breast cancer cells.ResultsMCF7 but not MDA-MB-231 breast cancer cells displayed strong resistance to adenovirus delivery of TRAIL. Only the combinatorial use of Ad5hTRAIL and AdIKKβKA infection sensitized MCF7 breast cancer cells to TRAIL induced cell death. Moreover, novel quantitative Real Time RT-PCR assays suggested that while the level of TRAIL Decoy Receptor-4 (TRAIL-R4) expression was the highest in MCF7 cells, it was the lowest TRAIL receptor expressed in MDA-MB-231 cells. In addition, conventional flow cytometry analysis demonstrated that TRAIL resistant MCF7 cells exhibited substantial levels of TRAIL-R4 expression but not TRAIL decoy receptor-3 (TRAIL-R3) on surface. On the contrary, TRAIL sensitive MDA-MB-231 cells displayed very low levels of surface TRAIL-R4 expression. Furthermore, a DcR2 siRNA approach lowered TRAIL-R4 expression on surface and this sensitized MCF7 cells to TRAIL.ConclusionThe expression of TRAIL-R4 decoy receptor appeared to be well correlated with TRAIL resistance encountered in breast cancer cells. Both adenovirus mediated IKKβKA expression and a DcR2 siRNA approach sensitized MCF7 breast cancer cells to TRAIL.

Increased serum sTRAIL levels were correlated with survival in bevacizumab-treated metastatic colon cancer

BackgroundColorectal cancer is the third most common cancer and the third leading cause of cancer-related death. Bevacizumab is a humanized monoclonal antibody developed against vascular endothelial growth factor (VEGF) for the treatment of metastatic cancer. The parameters of RECIST (Response Evaluation Criteria for Solid Tumors) are not adequate to detect important treatment effects and response. Our goal was to evaluate the possibility of using sTRAIL (serum-soluble TNF-related apoptosis-inducing ligand) and VEGF as markers of treatment efficacy and prognosis in patients with metastatic colon cancer.MethodssTRAIL and VEGF levels were measured by ELISA in the sera of 16 bevacizumab-treated metastatic colon cancer patients and 10 presumably healthy age-matched controls. The measurements were taken before and after treatment for comparison purposes.ResultsElevated levels of sTRAIL were found in seven out of 16 patients after bevacizumab treatment. Although these patients had a median survival time of 20.6 months, the remaining bevacizumab-treated patients who did not show an increase in sTRAIL had a median survival time of 9.4 months. As expected, serum VEGF levels were decreased in all patients who received bevacizumab therapy and showed no correlation between serum VEGF levels and patient survival (data not shown).ConclusionsSerum sTRAIL levels might be a useful predictor of prognosis in metastatic colon cancer, in the early evaluation stages following bevacizumab treatment.

NF-κB targeting by way of IKK inhibition sensitizes lung cancer cells to adenovirus delivery of TRAIL.

BackgroundLung cancer causes the highest rate of cancer-related deaths both in men and women. As many current treatment modalities are inadequate in increasing patient survival, new therapeutic strategies are required. TNF-related apoptosis-inducing ligand (TRAIL) selectively induces apoptosis in tumor cells but not in normal cells, prompting its current evaluation in a number of clinical trials. The successful therapeutic employment of TRAIL is restricted by the fact that many tumor cells are resistant to TRAIL. The goal of the present study was to test a novel combinatorial gene therapy modality involving adenoviral delivery of TRAIL (Ad5hTRAIL) and IKK inhibition (AdIKKβKA) to overcome TRAIL resistance in lung cancer cells.MethodsFluorescent microscopy and flow cytometry were used to detect optimum doses of adenovirus vectors to transduce lung cancer cells. Cell viability was assessed via a live/dead cell viability assay. Luciferase assays were employed to monitor cellular NF-κB activity. Apoptosis was confirmed using Annexin V binding.ResultsNeither Ad5hTRAIL nor AdIKKβKA infection alone induced apoptosis in A549 lung cancer cells, but the combined use of Ad5hTRAIL and AdIKKβKA significantly increased the amount of A549 apoptosis. Luciferase assays demonstrated that both endogenous and TRAIL-induced NF-κB activity was down-regulated by AdIKKβKA expression.ConclusionsCombination treatment with Ad5hTRAIL and AdIKKβKA induced significant apoptosis of TRAIL-resistant A549 cells, suggesting that dual gene therapy strategy involving exogenous TRAIL gene expression with concurrent IKK inhibition may be a promising novel gene therapy modality to treat lung cancer.

Correlation of binge eating disorder with level of depression and glycemic control in type 2 diabetes mellitus patients

OBJECTIVE It is reported that eating disorders and depression are more common in patients with type 2 diabetes mellitus (T2DM). In this study, we aimed to determine the prevalence of binge eating disorder (BED) in T2DM patients and examine the correlation of BED with level of depression and glycemic control. METHOD One hundred fifty-two T2DM patients aged between 18 and 75 years (81 females, 71 males) were evaluated via a Structured Clinical Interview for DSM-IV Axis I Disorder, Clinical Version in terms of eating disorders. Disordered eating attitudes were determined using the Eating Attitudes Test (EAT) and level of depression was determined using the Beck Depression Scale. Patients who have BED and patients who do not were compared in terms of age, gender, body mass index, glycosylated hemoglobin (HbA1c) levels, depression and EAT scores. RESULTS Eight of the patients included in the study (5.26%) were diagnosed with BED. In patients diagnosed with BED, depression and EAT scores were significantly high (P<.05). A positive correlation was found between EAT scores and depression scores (r = +0.196, P<.05). No significant difference was found in HbA1c levels between patients with BED and those without (P<.05). CONCLUSIONS T2DM patients should be examined in terms of the presence of BED and disordered eating attitudes. Psychiatric treatments should be organized for patients diagnosed with BED by taking into consideration comorbid depression.

TRAIL and DcR1 Expressions Are Differentially Regulated in the Pancreatic Islets of STZ- versus CY-Applied NOD Mice

TNF-related apoptosis-inducing ligand (TRAIL) is an important component of the immune system. Although it is well acknowledged that it also has an important role in Type 1 Diabetes (T1D) development, this presumed role has not yet been clearly revealed. Streptozotocin (STZ) and Cyclophosphamide (CY) are frequently used agents for establishment or acceleration of T1D disease in experimental models, including the non-obese diabetic (NOD) mice. Although such disease models are very suitable for diabetes research, different expression patterns for various T1D-related molecules may be expected, depending on the action mechanism of the applied agent. We accelerated diabetes in female NOD mice using STZ or CY and analyzed the expression profiles of TRAIL ligand and receptors throughout disease development. TRAIL ligand expression followed a completely different pattern in STZ- versus CY-accelerated disease, displaying a prominent increase in the former, while appearing at reduced levels in the latter. Decoy receptor 1 (DcR1) expression also increased significantly in the pancreatic islets in STZ-induced disease. Specific increases observed in TRAIL ligand and DcR1 expressions may be part of a defensive strategy of the beta islets against the infiltrating leukocytes, while the immune-suppressive agent CY may partly hold down this defense, contributing further to diabetes development.

Diabetes-Resistant NOR Mice Are More Severely Affected by Streptozotocin Compared to the Diabetes-Prone NOD Mice: Correlations with Liver and Kidney GLUT2 Expressions

Nonobese Diabetic (NOD) mice are susceptible strains for Type 1 diabetes development, and Nonobese Diabetes-Resistant (NOR) mice are defined as suitable controls for NOD mice in non-MHC-related research. Diabetes is often accelerated in NOD mice via Streptozotocin (STZ). STZ is taken inside cells via GLUT2 transmembrane carrier proteins, the major glucose transporter isoforms in pancreatic beta cells, liver, kidneys, and the small intestine. We observed severe adverse effects in NOR mice treated with STZ compared to NOD mice that were made diabetic with a similar dose. We suggested that the underlying mechanism could be differential GLUT2 expressions in pancreatic beta cells, yet immunofluorescent and immunohistochemical studies revealed similar GLUT2 expression levels. We also detected GLUT2 expression profiles in NOD and NOR hepatic and renal tissues by western blot analysis and observed considerably higher GLUT2 expression levels in liver and kidney tissues of NOR mice. Although beta cell GLUT2 expression levels are frequently evaluated as a marker predicting STZ sensitivity in animal models, we report here very different diabetic responses to STZ in two different animal strains, in spite of similar initial GLUT2 expressions in beta cells. Furthermore, use of NOR mice in STZ-mediated experimental diabetes settings should be considered accordingly.

Previously Unreported Chromosomal Aberrations of t(3;3)(q29;q23), t(4;11)(q21;q23), and t(11;18)(q10;q10) in a Patient with Accelerated Phase Ph+ CML.

Chronic myelogenous leukemia (CML) is a clonal hematological disorder, which is characterized by the presence of the classical or variant Philadelphia translocations. During the progression to blastic phase of the disease secondary chromosomal abnormalities may emerge. Such secondary chromosomal abnormalities are nonrandom, the more frequent ones being trisomy 8 and 19, supernumerary i(17q), and extra Philadelphia chromosomes. Furthermore, a minor percentage of the patients may acquire different secondary chromosomal abnormalities including translocations between other chromosomes. We report here a patient with Ph+ CML presenting secondary chromosomal abnormalities including t(4;11)(q21;q23), t(3;3)(q29;q23) and t(11;18)(q10;q10) during the course of CML progression.

Investigation Of Mdm2 Oncogene Copy Number Alterations in Cases With Chronic Lymphocytic Leukemia

MDM2 gene amplification was investigated by the fluorescence in situ hybridization (FISH) method in 40 patients with CLL and 20 patients with Ph+ chronic myeloid leukemia as a control group. Informed consent was received. The modified Rai staging system was used for staging our patients. Conventional cytogenetic analysis and FISH analysis using CLL-specific FISH probes for 17p13.1 (TP53), 13q14 (RB), 6q22-q23 (MYB), 11q22.3 (ATM), and chromosome 12 centromere were applied for all patients. The cytogenetic analysis revealed abnormal karyotypes in 3 of 40 patients. 47,XX,inv(9)(p11q13),del(13)(q14),+21[2],46,XY,del (7) (q31),dup(12)(q21q21)[8], and 46,XY,del(20)(q12)[6] karyotypes were observed in these patients. MDM2 gene amplification could not be detected in either the patient or the control group. FISH analysis results were as follows in CLL cases: deletion of 17p13.1 in 16 cases (40%), 13q14 deletion in 13 cases (32.5%), trisomy 12 in 12 cases (30%), 11q22.3 deletion in 6 cases (15%), and 6q23 deletion in 1 case (2.5%). Frequencies of molecular cytogenetic findings are presented in Figure 1A. Compared to the literature, where the frequency of deletion of 17p13.1 in early-stage CLL was reported between 7% and 10% [7,8], the higher rate observed in 75% of our CLL patients might be due to differences in the methods and probes used, variability of laboratory cut-off values, or the limited number of cases in this study. The clinical implication of having 17p13.1 deletions in CLL cases might be more dependent on the extent of 17p13.1 deletion than the stage of the disease [9]. In the present study, only 4 patients had 17p13.1 deletion in >20 cells. Two of them died because of progressive disease and the other two were lost to follow-up. If evaluated from this perspective, the high level of 17p13.1 deletion was observed in 10% of our cases. It has been observed that patients with 17p13.1 and 11q2.3 deletion have a poor prognosis, and patients with isolated 13q14 deletion were found to have slower progression and longer survival time

Coexistence of deletion, ring, and monosomy of chromosome 7 in a patient with MDS-RAEB-2

The myelodysplastic syndromes (MDS) are a group of hematologic diseases affecting primarily elderly people and there is a high risk of developing into acute myeloid leukemia (AML). MDS is characterized by ineffective and dysplastic hematopoiesis in bone marrow. The clinical course of the disease is highly variable. Many of patients may survive with disease for several years, or cytopenias or leukemic development can cause death within a few months. The median age at diagnosis is 60 to 75 years in adult MDS (1,2). The incidence of cytogenetic abnormalities is about 35–60% in MDS patient. -5/del(5q), -7/del(7q), +8, del(20q) and –Y are the most frequent abnormalities are determined by conventional cytogenetics and FISH (3).