İki küçük avcının korkunç sergüzeştleri

M. K.'nın Yeni Yol'da tefrika edilen İki Küçük Avcının Korkunç Sergüzeştleri adlı romanıArşivdeki eksikler nedeniyle romanın tam metni verilememiştir. Bkz. Tefrika bilgi form

The extracellular matrix protein ITIH5 is a novel prognostic marker in invasive node-negative breast cancer and its aberrant expression is caused by promoter hypermethylation

Inter-alpha-trypsin inhibitors (ITIs) are protease inhibitors stabilizing the extracellular matrix. ITIs consist of one light (bikunin) and two heavy chains (ITIHs). We have recently characterized ITIH5, a novel member of the ITIH gene family, and showed that its messenger RNA is lost in a high proportion of breast tumours. In the present study, an ITIH5-specific polyclonal antibody was generated, validated with western blot and used for immunohistochemical analysis on a tissue microarray; ITIH5 was strongly expressed in epithelial cells of normal breast (n=11/15), while it was lost or strongly reduced in 42% (92/217) of invasive breast cancers. ITIH5 expression in invasive carcinomas was associated with positive expression of oestrogen receptor (P=0.008) and histological grade (P=0.024). Correlation of ITIH5 expression with clinical outcome revealed that patients with primary tumours retaining abundant ITIH5 expression had longer recurrence-free survival (RFS; P=0.037) and overall survival (OS; P=0.044), compared to those with reduced expression (mean RFS: 102 vs 78 months; mean OS: 120 vs 105 months). Methylation-specific PCR analysis frequently showed strong methylation of the ITIH5 promoter in primary breast tumours (41%, n=109) and breast cancer cell lines (n=6). Methylation was significantly associated with mRNA loss (P<0.001; n=39), and ITIH5 expression was induced after treatment of tumour cell lines with the demethylating agent 5-aza-2'-deoxycytidine. Moreover, ITIH5 promoter methylation was significantly associated with reduced OS (P=0.008). The cellular function of ITIH5 was evaluated by forced expression of a full-length ITIH5 complementary DNA in the breast cancer cell line MDA-MB-231, which does not endogenously express ITIH5. ITIH5-expressing clones showed a 40% reduced proliferation rate compared to mock-transfected cells. Overall, these data show that promoter methylation-mediated loss of ITIH5 expression is associated with unfavourable outcome in breast cancer patients, and thus ITIH5 could be used as a prognostic marker, although this marker is not multivariate independent due to its close association with ER expression. Our data indicate that ITIH5 is a candidate class II tumour suppressor gene and could be involved in tumour progression, invasion and metastasis, as its absence is associated with increased proliferation rates and a prognostic value indicating poor clinical outcome