[Distribution Characteristics and Source Analysis of Polycyclic Aromatic Hydrocarbons in Salinized Farmland Soil from the Oil Mining Area of the Yellow River Delta].

Eighty-nine soil samples were collected from the Binzhou oil mining area of the Yellow River Delta (including 83 farmland soil samples and 6 soil samples from an oil extraction area). A total of 16 US-EPA priority polycyclic aromatic hydrocarbons (PAHs) were measured by gas chromatography-mass spectrometry (GC-MS). Principal component analysis (PCA) and positive matrix factorization (PMF) were employed to investigate potential source apportionment of PAHs in the farmland soil. The total PAH concentrations ranged from 31.5 µg·kg-1 to 1399.4 µg·kg-1 (dry weight) with an arithmetic mean concentration of 119.4 µg·kg-1. The characteristics of PAHs showed that 4- to 6-ring PAHs were slightly dominant in this study area, and most of the PAHs were significantly correlated (P<0.01), which indicates that the sources of the PAHs had some similarities in this sampling area. Source apportionment results derived from two different models were similar, indicating that the sources of PAHs were coal combustion, biomass combustion, fossil fuel combustion, and diesel combustion. The results of the PMF were more detailed, with the following four factors being identified:gasoline combustion (24.05%), diesel combustion (6.17%), low-temperature pyrolysis processes (60.67%), and coal combustion (9.11%).

Reactivation of Syk gene by AZA suppresses metastasis but not proliferation of breast cancer cells.

Spleen tyrosine kinase (Syk) is reported to be involved in the suppression of proliferation and invasion of breast cancer. Methylation-mediated Syk gene silencing is found in a subset of breast cancer. In this study, we used a DNA methyltransferase inhibitor, 5-aza-2-deoxycytidine (AZA), to restore Syk expression of breast cancer cells. Surprisingly, we found that AZA treatment could reestablish the expression of Syk, but not affect the proliferation of breast cancer cells. Moreover, tumor formation in situ by MDA-MB-435s treated with (+) or without (-) AZA in a nude mice MFP (Mammary fat pad) model did not show significant difference, too. Interestingly, pulmonary metastasis was still significantly suppressed in MDA-MB-435s(+) group (1/9 vs. 7/9). Our findings suggested Syk may be more correlated to metastasis rather than proliferation. This study implied a potential use of Syk methylation as a valuable biomarker to detect high metastatic potential cancerous lesions and the prospect of AZA to join the arsenal of drug candidates to be developed as a new reagent for management of advanced breast cancer.

Correlation of tumor-positive ratio and number of perigastric lymph nodes with prognosis of patients with surgically-removed gastric carcinoma.

AIM: To evaluate the tumor-positive ratio and number of perigastric lymph nodes as prognostic factors of gastric carcinoma in surgically-treated patients. METHODS: The postoperative survival of 169 patients with gastric cancer who were performed D2 curative gastrectomy was analyzed with regard to its lymph node metastasis ratio and number. Meanwhile correlation of tumor-positive ratio and number of perigastric lymph nodes with pathological parameters of these patients was studied. RESULTS: The overall 5-year survival rate of all the patients studied was 29.6%. The 5-year cumulative survival rate in patients with 1%-20% and more than 20% of tumor-positive lymph nodes was 70.6% and 12.0% respectively, and 46.6% and 17.4% in those with 1-5 and more than 5 of tumor-positive lymph nodes respectively, which were significantly decreased with the increment of involved lymph nodes assessed by either numbers or ratio (P<0.05). Multiple stepwise regression analysis showed that both the positive ratio and number of tumor-involved lymph nodes were sensitive prognostic factors in these surgically-treated patients, which were also significantly correlated with tumor size and depth of submucosal invasion (P<0.05). CONCLUSION: Tumor-positive ratio and number of perigastric lymph nodes are associated with cancer progression and five-year survival rate, and may serve as valuable prognostic factors of gastric cancer in surgically-treated patients.