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Wingless Type (WNT) signaling pathway is an evolutionarily conserved pathway that is crucial for the cell fate determination, survival and expansion of lymphocyte progenitors. It has been demonstrated that deregulated WNT signaling is one of the participating mechanism underlying lymphoid leukemogenesis. Inactivating mutations and methylation in Adenomatous Polyposis Coli (APC) gene, a negative regulator of WNT pathway, can cause ligand independent WNT pathway simulation. In this study, promoter methylation and expression of the APC gene is evaluated in childhood lymphoid and myeloid acute leukemia patients (n= 118) and representative cell lines by using methylation specific PCR (MS-PCR) and real time quantitative PCR (QRT-PCR). APC gene promoter found hypermethylated in the 56% of childhood acute leukemia patients [49.2% of B-cell acute lymphoblastic leukemia (B-ALL), 62.5% of T-cell acute lymphoblastic leukemia (T-ALL) and 64.1% of Acute myeloid leukemia (AML)]. To evaluate the reflection of promoter methylation, APC mRNA levels were examined and found that all acute lymphoblastic leukemia subgroups have statistically lower APC expression levels compared to controls. Although there was no association with clinical parameters, promoter hypermethylation of APC gene seems to be a common epigenetic event in acute leukemia and leading to differential expression levels among different acute leukemia phenotypes. [ABSTRACT FROM AUTHOR]

The aim of this study is to search critical renin-angiotensin system (RAS) elements in myeloid leukemic cell lines. Human acute myeloid leukemia (AML) cell lines, KG-1 and HL-60, were cultured. We searched for the gene expression of the major RAS components in KG-1 and HL-60 cell lines by quantitative real-time polymerase chain reaction analysis (qRT-PCR). Angiotensin-converting enzyme I (ACE I) and ACE II mRNA expressions were detected in KG-1 AML cell line. Relative expression of ACE I was higher than ACE II expression in this myeloid leukemic cells. Likewise, RENIN, angiotensinogen (ANGTS), and ACE I mRNA expressions were detected in HL-60 promyelocytic cell line. Relative RENIN expression was the highest, whereas ACE I expression was the lowest in HL- 60 neoplastic myeloid cells. These findings indicate that there is a biologically active local RAS in the hematopoietic system in normal and pathological states. [ABSTRACT FROM AUTHOR]

We aimed to investigate the frequency of c-erb-B2 expression rate and its association with clinicopathological parameters in our gastric carcinoma series to make a contribution to emerging data on this oncogene. One hundred thirty-nine gastric adenocarcinoma patients underwent total gastrectomy between years 2006 and 2011 were selected to the study. C-erb-B2 expressions were determined by using immunohistochemical and/or chromogenic in situ hybridisation methods in tumor tissues. A total of 16 (11.5%) gastric adenocarcinoma cases were found positive for c-erb-B2 expression. Out of 16 positive cases, 13 had intestinal type adenocarcinomas. C-erb-B2 overexpression was significantly associated with histologic subtype (p= 0.001), and histologic tumor grade (p= 0.001). The frequency of overexpression in intestinal subtype (21.7%) was comparable with the known rates of overexpression in breast cancer. This results indicate that C-erb-B2 expression may identify a subgroup in gastric carcinoma cases which may benefit from targeted treatment modalities among Turkish population. [ABSTRACT FROM AUTHOR]