Ibrahim Sehitoglu

XRCC1 Gene Polymorphisms and Risk of Lung Cancer in Turkish Patients

Abstract Polymorphisms in the X-ray repair cross complementing 1 (XRCC1) gene have been found to be associated with susceptibility to various types of cancers. We investigated the association between the XRCC1 gene Arg399Gln polymorphism and the susceptibility to lung cancer in Turkish patients. To determine the association of this polymorphism with the risk of lung cancer in Turkish patients, a hospital-based case-control study was designed, involving 67 patients with lung cancer and 60 control subjects with no cancer history who were matched for age and gender. XRCC1 genotypes (Arg/Arg, Arg/Gln, and Gln/Gln) were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis on genomic DNA. No statistically significant relationship was determined between the lung cancer and control groups (p>0.05). Among the patients, 61% were Arg/Arg, 28% were Arg/Gln, and 11% were Gln/Gln. Among the controls, 50% were Arg/Arg, 38% were Arg/Gln, and 12% were Gln/Gln. There was no difference in the distribution of XRCC1 genotypes or the frequencies of the Arg (75% versus 69%) and Gln (25% versus 31%) alleles between the lung cancer patients and controls. Our results suggest that the XRCC1 gene Arg399Gln polymorphism is not associated with an increased risk for the development of lung cancer in Turkish patients.

The Role of p16, p21, p27, p53 and Ki-67 Expression in the Differential Diagnosis of Cutaneous Squamous Cell Carcinomas and Keratoacanthomas: An Immunohistochemical Study.

BACKGROUNDnDistinguishing squamous cell carcinoma (SCC) from keratoacanthoma (KA) by histopathological features may not be sufficient for a differential diagnosis, as KAs may, in some cases, imitate well-differentiated SCCs.nnnAIMSnIn this study, we investigated whether the expression of the p16, p21, p27, p53 genes and a Ki-67 proliferation index are useful in distinguishing between these two tumors.nnnSTUDY DESIGNnCross-sectional study.nnnMETHODSnImmunohistochemistry was used to investigate the expression of the p16, p21, p27, p53 genes and the Ki-67 proliferation index was investigated in well-differentiated SCC with KA-like features (n=40) and KA (n=30).nnnRESULTSnThe results of all of the examined markers, except for p27 (p16, p21, p53, and Ki-67) were found to be significantly different between the SCC and KA samples (p<0.05).nnnCONCLUSIONnIn well-differentiated SCC with KA-like features and KA cases where the differential diagnosis is difficult from a histopathological perspective, the use of p16, p21, p53 expression and a Ki-67 proliferation index can be useful for the differential diagnosis of SCCs and KAs.

Somatostatin receptor 2 and 5 expressions in gastroenteropancreatic neuroendocrine tumors in Turkey.

BACKGROUNDnGastroenteropancreatic neuroendocrine tumors (GNs) are slow growing and although their incidence has increased in recent years, they are relatively rarely seen. Somatostatin analogues are used in the treatment of GNs that express somatostatin receptor (SR). We aimed to investigate the expression of SR2 and SR5 in GNs.nnnMATERIALS AND METHODSnIn this study the expression of SR2 and SR5 was investigated immunohistochemically in 49 cases (26 males, 23 females) diagnosed and graded with GN according to the World Health Organization classification 2010.nnnRESULTSnThe percentage of SR2 staining was 91.0% in grade 1, 82.8% in grade 2 and 100% in grade 3. On the other hand, the percentage of SR5 staining was 81.8% % in grade 1, 60.0% in grade 2 and 0% in grade 3. According to the tumor localization, the percentages of SR2 expression were as follows: pancreas 85.7%, stomach 100%, small bowel 70%, appendix 85.7% and rectum 100%. The percentages of SR5 expression were: pancreas 61,9%, stomach 37.5%, small bowel 70%, appendix 71.5% and rectum 66.6%. There was a significant negative correlation between ki67 percentage and SR5 expression (r=-0.341, p=0.016).nnnCONCLUSIONSnIn this study, GNs were found to highly express SR2 and SR5. Although the expression of SR2 and SR5 changed according to tumor localization, the expression of SR2 was higher than the expression of SR5 in GN. There was a significant negative correlation between ki67 and SR5. Accordingly, SR5 may be a prognostic indicator of GN.

Relationships Between C-Kit Expression and Mean Platelet Volume in Benign, Preneoplastic and Neoplastic Endometrium

BACKGROUNDnc-Kit is a proto-oncogene that encodes a tyrosine kinase receptor (CD117). Mean platelet volume (MPV) is a useful marker for demonstrating thrombocyte function. We aimed to investigate whether c-kit is expressed in benign, preneoplastic and neoplastic endometrial tissues and whether MPV has a relation with c-kit expression and its intensity.nnnMATERIALS AND METHODSnc-Kit expression was investigated immunohistochemically in 10 samples of normal endometrium (n=10), simple endometrial hyperplasia (5 cases with atypia and 10 cases without atypia), complex endometrial hyperplasia (10 cases with atypia and 10 cases without atypia) and endometrial cancer (EC) (10 cases grade I and 10 cases grade II) and MPV of all cases was checked.nnnRESULTSnc-Kit expression was observed at very low rates in cases with normal endometrial tissues (NE) and in hyperplasia without atypia. c-Kit expression and immunostaining were strong in endometrial atypia and EC. MPV levels of complex atypical endometrial hyperplasia (CAEH) (p:0.002), EC grade I (ECG I) (p<0.001) and EC grade II (ECG II) (p<0.001) were significantly elevated when compared with the NE group. Both c-kit expression and intensity of immunostaining had a positive correlation with MPV level.nnnCONCLUSIONSnWhile c-kit expression and intensity of immunostaining were mildly positive in NE and hyperplasia without atypia, they were clearly observed in EC and hyperplasia with atypia. As c-kit expression is related to the mutagenesis a long-term follow- up may be needed in these cases. A high MPV level may be a good test for demonstrating c-kit expression and intensity of immunostaining.

Protective effects of tumor necrosis factor alpha inhibitors on methotrexate-induced pancreatic toxicity

BACKGROUNDnMethotrexate (MTX), a folate antagonist, is commonly used in the treatment of many different types of cancer and inflammatory diseases, including pancreatic cancer, although its side effects on the pancreas have not yet been researched. The mechanism of MTX-induced toxicity is not well known, and it has been reported in high-dose toxicity studies that the pancreas is sensitive to toxic effects.nnnOBJECTIVESnThe aim of our study was to determine whether adalimumab (ADA) has a preventive effect on MTX-induced pancreas toxicity in rats.nnnMATERIAL AND METHODSnThe rats were equally and randomly divided into 3 groups (Group 1 comprised the healthy controls, Group 2 was the MTX group, and Group 3 was the MTX + ADA group). The rats in Groups 2 and 3 received an intraperitoneal (ip.) single-dose injection of MTX (20 mg/kg). A single dose of 5 mg/kg ADA (REMICADE®) was administered ip. to Group 3. All the rats were sacrificed under anesthesia 5 days after receiving the MTX injection.nnnRESULTSnSignificantly higher mean edema, necrotic cell, and inflammatory scores were recorded in Groups 2 and 3 compared to those recorded in Group 1. Significantly decreased edema, number of necrotic cells, and inflammatory scores were noted in Group 3 than in Group 2. A decrease in islets of Langerhans cell insulin and somatostatin-positive interneurons was demonstrated after the administration of MTX. An increase in insulin and somatostatin-positive cells in islets of Langerhans, as well as a remodeling of the structure of the pancreas, was shown following treatment with ADA.nnnCONCLUSIONSnAdalimumab was demonstrated to have a protective effect against MTX-induced pancreatic injury in this study.