Continuous Low-dose-rate Irradiation of Iodine-125 Seeds Inhibiting Perineural Invasion in Pancreatic Cancer.

Background: Perineural invasion (PNI) is a histopathological characteristic of pancreatic cancer (PanCa). The aim of this study was to observe the treatment effect of continuous low-dose-rate (CLDR) irradiation to PNI and assess the PNI-related pain relief caused by iodine-125 ( 125 I) seed implantation.

Methods: The in vitro PNI model established by co-culture with dorsal root ganglion (DRG) and cancer cells was interfered under 2 and 4 Gy of 125 I seeds CLDR irradiation.

Continuous and low-energy 125I seed irradiation changes DNA methyltransferases expression patterns and inhibits pancreatic cancer tumor growth.

Background: Iodine 125 (125I) seed irradiation is an effective treatment for unresectable pancreatic cancers. However, the radiobiological mechanisms underlying brachytherapy remain unclear. Therefore, we investigated the influence of continuous and low-energy 125I irradiation on apoptosis, expression of DNA methyltransferases (DNMTs) and cell growth in pancreatic cancers.

[The relationship between methylenetetrahydrofolate reductase gene polymorphism and microsatellite instability in gastric cancer].

Objective: To explore the relationship between methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and microsatellite instability (MSI) in patients with gastric cancer.

Methods: MTHFR gene C677T and A1298C polymorphism were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and MSI was examined with PCR.

Results: MTHFR gene C677T and A1298C polymorphisms were analyzed on 122 gastric cancers and 110 normal controls The genotype frequencies of MTHFR 677CC, 677CT and 677TT were 47.

[Antisense DNMT1 gene fragment in the sensitivity change of SMMC-7721 cells to tumor necrosis factor related apoptosis inducing ligand and its mechanism].

Objective: To observe the sensitivity change of SMMC-7721 cells transfected with antisense DNMT1 gene fragment to tumor necrosis factor related apoptosis inducing ligand (TRAIL) and its mechanism.

Methods: Cell survival rate was measured by trypan blue, apoptosis rate by TUNEL method and the expression of bcl-2, bax and bad by flow cytometry.

Results: Cell survival rate of SMMC-7721 cells transfected with antisense DNMT1 gene fragment was markedly lower than that transfected with sense DNMT1 gene fragment or empty vector (P < 0.

[Cooperative anti-tumor effect of aspirin and TNF-related apoptosis-inducing ligand].

Objective: To observe the anti-tumor effect of combination TNF-related apoptosis-inducing ligand (TRAIL) with aspirin on liver cancer cell line, SMMC-7721.

Methods: The survival fraction of SMMC-7721 cells was measured by MTT assay, apoptosis rate and cell cycle was determined by flow cytometry, and the expression of apoptosis-related gene was identified by western blot.

Results: The survival fraction of SMMC-7721 cells treated with 300 ng/ml TRAIL, 3 mmol/L or 10 mmol/L aspirin alone was 82.