Dynamic Recruitment of Licensing Factor Cdt1 to Sites of DNA Damage

For genomic integrity to be maintained, the cell cycle and DNA damage responses must be linked. Cdt1, a G1-specific cell-cycle factor, is targeted for proteolysis by the Cul4-Ddb1Cdt2 ubiquitin ligase following DNA damage. Using a laser nanosurgery microscope to generate spatially restricted DNA damage within the living cell nucleus, we show that Cdt1 is recruited onto damaged sites in G1 phase cells, within seconds of DNA damage induction. PCNA, Cdt2, Cul4, DDB1 and p21Cip1 also accumulate rapidly to damaged sites. Cdt1 recruitment is PCNA-dependent, whereas PCNA and Cdt2 recruitment are independent of Cdt1. Fitting of fluorescence recovery after photobleaching profiles to an analytic reaction-diffusion model shows that Cdt1 and p21Cip1 exhibit highly dynamic binding at the site of damage, whereas PCNA appears immobile. Cdt2 exhibits both a rapidly exchanging and an apparently immobile subpopulation. Our data suggest that PCNA provides an immobile binding interface for dynamic Cdt1 interactions at the site of damage, which leads to rapid Cdt1 recruitment to damaged DNA, preceding Cdt1 degradation

Heat Shock Protein-27, -60 and -90 expression in gastric cancer: association with clinicopathological variables and patient survival

<p>Abstract</p> <p>Background</p> <p>Heat shock proteins (HSPs) are ubiquitous, highly conserved proteins across all the species and play essential roles in maintaining protein stability within the cells under normal conditions, while preventing stress-induced cellular damage. HSPs were also overexpressed in various types of cancer, being associated with tumor cell proliferation, differentiation and apoptosis. The aim of the present study was to evaluate the clinical significance of HSP -27, -60, and -90 expression in gastric carcinoma.</p> <p>Methods</p> <p>HSP -27, -60, and -90 proteins expression was assessed immunohistochemically in tumoral samples of 66 gastric adenocarcinoma patients and was statistically analyzed in relation to various clinicopathological characteristics, tumor proliferative capacity and patients' survival.</p> <p>Results</p> <p>HSP-27, -60, -90 proteins were abundantly expressed in gastric adenocarcinoma cases examined. HSP-27 expression was significantly associated with tumor size (pT, P = 0.026), the presence of organ metastases (pM, P = 0.046) and pStage (P = 0.041), while HSP-27 staining intensity with nodal status (pN, P = 0.042). HSP-60 expression was significantly associated with patients' sex (P = 0.011), while HSP-60 staining intensity with patients' age (P = 0.027) and tumor histopathological grade (P = 0.031). HSP-90 expression was not associated with any of the clinicopathological parameters examined; however, HSP-90 staining intensity was significantly associated with tumor size (pT, P = 0.020). High HSP-90 expression was significantly associated with longer overall survival times in univariate analysis (log-rank test, P = 0.033), being also identified as an independent prognostic factor in multivariate analysis (P = 0.026).</p> <p>Conclusion</p> <p>HSP-27, -60, and -90 were associated with certain clinicopathological parameters which are crucial for the management of gastric adenocarcinoma patient. HSP-90 expression may also be an independent prognostic indicator in gastric adenocarcinoma patients.</p

Gene expression profiles in human gastric cancer: expression of maspin correlates with lymph node metastasis

To seek for a candidate gene that would regulate tumour progression and metastasis in gastric cancer, we investigated gene expression profiles by using DNA microarray. Tumour tissue and adjacent normal tissue were obtained from 21 patients with gastric cancer and then examined for their gene expression profiles by the Gene Chip® Human U95Av2 array, which includes 12 000 human genes and EST sequences. A total of 25 genes were upregulated and two genes were downregulated by at least four-fold in the tumour tissue. In a further analysis according to lymph node metastasis, the expressed levels of maspin, as well as carcinoembryonic antigen and nonspecific crossreacting antigen were significantly higher in tumours with lymph node metastasis than in those without it. Maspin expression in 85 gastric cancer patients was further investigated by using immunohistochemistry. Maspin expression was not observed in normal gastric epithelia without intestinal metaplasia. In contrast, maspin was expressed in 74 of 85 tumour tissues. There was a significant correlation between the incidence of maspin-positive tumour staining and lymph node metastasis. These results suggest that maspin has a potential role for tumour metastasis in gastric cancer

Employment status and work-related difficulties in stomach cancer survivors compared with the general population

Little was known about work situation and work-related difficulties, including housework after stomach cancer diagnosis. We aimed to compare employment status and work-related difficulties between stomach cancer survivors and the general population. We enrolled 408 stomach cancer survivors from two hospitals 28 months after diagnosis and 994 representative volunteers from the general population from 15 geographic districts. Working was defined as being employed (including self-employed) and nonworking as being retired or a homemaker. Nonworking was significantly higher among stomach cancer survivors (46.6%) than in the general population (36.5%). Compared with the general population, the survivors had more fatigue in performing both housework (adjusted odds ratio (aOR)=2.08; 95% confidence interval (95% CI)=1.01–4.29) and gainful work (aOR=4.02; 2.55–6.33). More cancer survivors had reduced working hours (aOR=1.42; 95% CI=4.60–28.35) and reduced work-related ability (aOR=6.11; 95% CI=3.64–10.27) than did the general population. The association of nonworking with older age and being female was significantly more positive for survivors than for the general population. Among survivors, poorer Eastern Cooperation Oncology Group Performance Status and receiving total gastrectomy were positively associated with nonworking. Stomach cancer survivors experienced more difficulties in both housework and gainful employment than did the general population. Our findings on stomach cancer survivors' work-related difficulties and the predictors of nonworking will help physicians guide patients towards more realistic postsurgical employment plans

Hyperfibrinogenemia is associated with lymphatic as well as hematogenous metastasis and worse clinical outcome in T2 gastric cancer

BACKGROUND: Abnormal hemostasis in cancer patients has previously been described, however the correlation between the plasma fibrinogen level and cancer metastasis and prognosis has not been reported in a large-scale clinical study. METHODS: Preoperative plasma fibrinogen levels were retrospectively examined in 405 patients who underwent surgery for advanced gastric cancer. The association of fibrinogen levels with clinical/pathological findings and clinical outcome was evaluated. RESULTS: There was a positive correlation between plasma fibrinogen levels and the depth of invasion (p < 0.05). Hyperfibrinogenemia (>310 mg/dl) was independently associated with lymph node (Odds Ratio; 2.342, P = 0.0032) and liver (Odds Ratio; 2.933, P = 0.0147) metastasis, not with peritoneal metastasis in this series. Patients with hyperfibrinogenemia showed worse clinical outcome in T2 gastric cancer, however, there was no correlation of plasma fibrinogen level with prognosis in T3/T4 gastric cancer. CONCLUSION: Our results might support the idea that hyperfibrinogenemia can augment lymphatic and hematogeneous metastasis of advanced gastric cancer, which is major determinant of the prognosis in T2 gastric cancer. Therefore, in the situation without peritoneal involvement, hyperfibrinogenemia is a useful biomarker to predict the possible metastasis and worse clinical outcome in T2 gastric cancer