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Purpose In this study, we investigated the frequencies of mutations in DNA damage repair genes including BRCA1, BRCA2, homologous recombination genes and TP53 gene in ovarian high-grade serous carcinoma, alongside those of germline and somatic BRCA mutations, with the aim of improving the identification of patients suitable for treatment with poly(ADPribose) polymerase inhibitors. Materials and Methods Tissue samples from 77 Korean patients with ovarian high-grade serous carcinoma were subjected to next-generation sequencing. Pathogenic alterations of 38 DNA damage repair genes and TP53 gene and their relationships with patient survival were examined. Additionally, we analyzed BRCA germline variants in blood samples from 47 of the patients for comparison. Results BRCA1, BRCA2, and TP53 mutations were detected in 28.6%, 5.2%, and 80.5% of the 77 patients, respectively. Alterations in RAD50, ATR, MSH6, MSH2, and FANCA were also identified. At least one mutation in a DNA damage repair gene was detected in 40.3% of patients (31/77). Germline and somatic BRCA mutations were found in 20 of 47 patients (42.6%), and four patients had only somatic mutations without germline mutations (8.5%, 4/47). Patients with DNA damage repair gene alterations with or without TP53mutation, exhibited better disease-free survival than those with TP53 mutation alone. Conclusion DNA damage repair genes were mutated in 40.3% of patients with high-grade serous carcinoma, with somatic BRCAmutations in the absence of germline mutation in 8.5%. Somatic variant examination, along with germline testing of DNA damage repair genes, has potential to detect additional candidates for PARP inhibitor treatment. [ABSTRACT FROM AUTHOR]

Aims Fibulin-5 is an extracellular matrix (ECM) glycoprotein which has a role in the organisation and stabilisation of ECM structures and regulating cell proliferation and tumourigenesis. Here, the expression of fibulin-5 and its functional effects on the migration and invasion of ovarian cancer cells were assessed. Methods Expression of fibulin-5 was detected in 44 ovarian tumour tissues by qRT-PCR, Western blotting and immunohistochemistry. We performed cell migration and invasion assays, and cell cycle analysis in fibulin-5 transfected SKOV3 (SKOV3-FBLN5) cells and the parental SKOV3 cells. We further examined the expression of three tissue inhibitors of metalloproteinases (TIMPs) and seven matrix metalloproteinases (MMPs) by RT-PCR. Results mRNA and protein expression of fibulin-5 were down-regulated (0.05-fold and 0.1-fold) in ovarian carcinomas compared with control tissues (p<0.01 and p=0.022). In wound-healing and invasion assays, significantly fewer SKOV3-FBLN5 cells than SKOV3 control cells migrated and invaded (39.1%, p=0.046 and 70%, p=0.03, respectively), which was reversed by siRNA-treatment. Overexpression of fibulin-5 induced G2/M arrest and increased cyclin B1, CDC2 and CDC25C. Expression of TIMP-2 (0.56-fold), MMP-3 (0.43-fold) and MMP-13 (0.18-fold) was lower and MMP-9 expression (2.20-fold) was higher in SKOV3- FBLN5 cells than in control cells. Conclusions Fibulin-5 is significantly down-regulated in ovarian carcinoma and acts as a tumour suppressor by inhibiting the migration and invasion of ovarian cancer cells. [ABSTRACT FROM AUTHOR]

Perfect human stem cell genetic fidelity would prevent aging and cancer. However, perfection would be difficult to achieve, and aging is universal and cancers common. A hypothesis is that because mutations are inevitable over a human lifetime, downstream mechanisms have evolved to manage the deleterious effects of beneficial and lethal mutations. In the colon, a crypt stem cell architecture reduces the number of mitotic cells at risk for mutation accumulation, and multiple niche stem cells ensure that a lethal mutation within any single stem cell does not lead to crypt death. In addition, the architecture of the colon crypt stem cell niche may harness probability or chance to randomly discard many beneficial mutations that might lead to cancer. An analysis of somatic chromosome copy number alterations (CNAs) reveals a lack of perfect fidelity in individual normal human crypts, with age-related increases and higher frequencies in ulcerative colitis, a proliferative, inflammatory disease. The age-related increase in somatic CNAs appears consistent with relatively normal replication error and cell division rates. Surprisingly, and similar to point mutations in cancer genomes, the types of crypt mutations were more consistent with random fixation rather than selection. In theory, a simple "non-Darwinian" way to nullify selection is to reduce the size of the reproducing population. Fates are more determined by chance rather than selection in very small populations, and therefore selection may be minimized within small crypt niches. The desired effect is that many beneficial mutations that might lead to cancer are randomly lost by drift rather than fixed by selection. The subdivision of the colon into multiple very small stem cell niches may trade Darwinian evolution for non-Darwinian somatic cell evolution, capitulating to aging but reducing cancer risks. [ABSTRACT FROM AUTHOR]

Aims: Notch signalling plays diverse roles in malignant tumours as well as in normal tissue development. In this study we investigated the expression of Notch signalling pathway genes and their clinicopathological significance in gastric carcinomas. Methods and results: Notch1, Notch3, Jagged1, Jagged2 and Hes1 expression were analysed by quantitative real-time polymerase chain reaction (qRT-PCR) (n = 81) and immunohistochemistry (n = 103) in gastric carcinomas. MUC2 and MUC5AC expression were also assessed, using immunohistochemistry only. With qRT-PCR, Notch1, Notch3, Jagged1 and Jagged2 expression were increased significantly in tumour compared to normal tissue (P < 0.001, P = 0.002, P = 0.008 and P < 0.001, respectively). Overexpression of Notch3 and Jagged2 was associated with intestinal-type carcinomas (P = 0.024) and better histological differentiation (P = 0.047), respectively. Immunohistochemistry showed a reverse correlation between MUC2 and Notch3 or Jagged1 (P = 0.033 and P = 0.005, respectively) and between MUC5AC and Jagged1 or Hes1 (P = 0.004 and P = 0.002, respectively). Notch3 and Jagged2 gene overexpression related to a favourable outcome on univariate (P 0.046 and P = 0.042, respectively) and multivariate (P = 0.045, Notch3) analysis. Conclusions: The expression of Notch3 and Jagged2 is associated not only with gastric cancer development but also with the intestinal/glandular differentiation of gastric carcinoma cells, suggesting a role as a possible favourable prognostic indicator. [ABSTRACT FROM AUTHOR]

Kim T H, Kim Y K, Kwon Y, Heo J H, Kang H, Kim G & An H J (2010) Histopathology, 734-743 The pathological and clinical significance of aberrant miRNA expression in ovarian tumours has yet to be adequately documented. The aim of this study was to assess the differences in miRNA expression of human ovarian tumours according to histological subtype, and to determine whether miRNAs are potential diagnostic and prognostic markers in ovarian cancers. The miRNA expression profiles of 103 human ovarian tumours were evaluated. Via a bead-based miRNA microarray, five aberrant miRNAs were selected which were expressed differentially in malignant serous tumours from borderline and benign ovarian tumours, including miRNA (miR)-519a, miR-18b (up-regulation) and miR-153, miR-511 and miR-485-5p (down-regulation). We conducted quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) in order to confirm that these miRNAs are differentially expressed in different histological subtypes of ovarian tumours, and compared the expression profiles of these miRNAs between different clinical subsets. The expression of these miRNAs was correlated with clinicopathological parameters. miR-519a, miR-153 and miR-485-5p were differentially expressed in four major histotypes of ovarian cancers ( P < 0.05), which suggests that they might be of potential importance as diagnostic biomarkers. Down-regulation of miR-153 and miR-485-5p was correlated significantly with FIGO grade 3 ( P < 0.05). Down-regulation of miR-153 and up-regulation of miR-519a were correlated significantly with advanced clinical stage ( P < 0.05). The results of Kaplan-Meier survival analysis indicated that the higher expression of miR-519a in late stage serous carcinoma was associated significantly with poor progression-free survival ( P = 0.0058). A significant correlation was detected between the deregulation of specific types of miRNAs, such as miR-519a, miR-153 and miR-485-5p, and clinical variables as well as histological subtypes in ovarian cancers. Hence, these miRNAs may perform functions as diagnostic or prognostic biomarkers. [ABSTRACT FROM AUTHOR]

The amplification and overexpression ofHer2proto-oncogene have been found to be associated with the development and progression of human breast cancer. A polymorphic valine allele at codon 655 of theHer2gene (Her2V655) was suggested by some authors to be a susceptible genetic factor for the development of breast cancer. TheHer2polymorphism at codon 655 was investigated in 304 Korean women including 177 patients with breast cancer. The association betweenHer2genotype andHer2protein overexpression was also examined in breast cancers by immunohistochemistry.Her2V655 was not associated with a significant breast cancer risk (odds ratio (OR), 1.792; 95% confidence interval (CI), 0.459–6.991). The frequency of homozygous or heterozygous valine allele increased in stage 2 patients (OR, 1.67; 95% CI, 0.67–4.19), and patients in stages 3 and 4 (OR, 3.36; 95% CI, 0.85–13.42) compared to patients in stage 0. However, an association between the presence of the valine allele and the overexpression ofHer2protein could not be demonstrated. These results suggest thatHer2polymorphism at codon 655 is not associated with the development of breast cancer in Korean women. However, there is a possibility that the valine allele at codon 655 might be related to increased risk of breast cancer progression. [ABSTRACT FROM AUTHOR]