CXCR4/SDF-1 axis is involved in lymph node metastasis of gastric carcinoma

AIM:To investigate the role of CXC chemokine receptor-4 (CXCR4) and stromal cell-derived factor-1 (SDF-1) in lymph node metastasis of gastric carcinoma.METHODS:In 40 cases of gastric cancer,expression of CXCR4 mRNA in cancer and normal mucous membrane and SDF-1 mRNA in lymph nodes around the stomach was detected using quantitative polymerase chain reaction (PCR) (TaqMan) and immunohistochemistric assay.SGC-7901 and MGC80-3 cancer cells were used to investigate the effect of SDF-1 on cell proliferation and migration.RESULTS:Quantitative reverse transcription PCR and immunohistochemistry revealed that the expression level of CXCR4 in gastric cancer was significantly higher than that in normal mucous membrane (1.6244 ± 1.3801 vs 1.0715 ± 0.5243,P < 0.05).The expression level of CXCR4 mRNA in gastric cancer with lymph node metastasis was also significantly higher than that without lymph node metastasis (0.823 ± 0.551 vs 0.392 ± 0.338,P < 0.05).CXCR4 expression was significantly related to poorly differentiated,high tumor stage and lymph node metastasis.Significant differences in the expression level of SDF-1 mRNA were found between lymph nodes in metastatic gastric cancer and normal nodes (0.5432 ± 0.4907 vs 0.2640 ± 0.2601,P < 0.05).The positive expression of SDF-1 mRNA in lymph nodes of metastatic gastric cancer was consistent with the positive expression of CXCR4 mRNA in gastric cancer (r=0.776,P < 0.01).Additionally,human gastric cancer cell lines expressed CXCR4 and showed vigorous proliferation and migratory responses to SDF-1.AMD3100 (a specific CXCR4 antagonist) was also found to effectively reduce the migration of gastric cancer cells.CONCLUSION:The CXCR4/SDF-1 axis is involved in the lymph node metastasis of gastric cancer.CXCR4 is considered as a potential therapeutic target in the treatment of gastric cancer.

Preliminary Outcome of Individualized Abdominoperineal Excision for Locally Advanced Low Rectal Cancer

Background： The introduction of individualized abdominoperineal excision （APE） may minimize operative trauma and reduce the rate of complications. The purpose of this study was to evaluate the safety and efficacy of individualized APE for low rectal cancer. Methods： Fifty-six patients who underwent individualized APE from June 2011 to June 2015 were evaluated retrospectively in Beijing Chaoyang Hospital, Capital Medical University. The main outcome measures were circumferential resection margin （CRM） involvement, intraoperative perforation, postoperative complications, and local recurrence. Statistical analysis was performed using SPSS version 16.0. Results： Fifty （89%） patients received preoperative chemoradiotherapy： 51 （91%） patients were treated with the sacrococcyx preserved; 27 （48%） patients with the levator ani muscle partially preserved bilaterally; 20 （36%） patients with the levator ani muscle partially preserved unilaterally and the muscle on the opposite side totally preserved; 7 （13%） patients with intact levator ani muscle and part of the ischioanal fat bilaterally dissected; and 2 （4%） patients with part of the ischioanal fat and intact lavator ani muscle dissected unilaterally and the muscle on the opposite side partially preserved. The most common complications included sexual dysfunction （12%）, perineal wound complications （13%）, urinary retention （7%）, and chronic perineal pain （5%）. A positive CRM was demonstrated in 3 （5%） patients, and intraoperative perforations occurred in 2 （4%） patients. On multiple logistic regression analysis, longer operative time （P = 0.032） and more intraoperative blood loss （P = 0.006） were significantly associated with perineal procedure-related complications. The local recurrence was 4% at a median follow-up of 53 months （range： 30–74 months）. Conclusion： With preoperative chemoradiotherapy, individualized APE may be a relatively safe and feasible approach for low rectal cancer with acceptable oncological outcomes.

Clay minerals in the Pliocene-Quaternary sediments of the southern Yangtze coast, China: Sediment sources and palaeoclimate implications

Clay mineralogy was used as an indicator of the sediment source and prevailing climate and five suites （I-V） were identified throughout the borehole. Smectite was dominant in the bottom suite of the borehole, indicating the sediment was mainly derived from the local basalt when the study area stood as uplands during the Pliocene. The sharp reduction of smectite in suites II and III （Early Pleistocene） reflects a broader sediment provenance due to neo-tectonic subsidence of the study area. Significant climate fluctuations are indicated by distinct variations in the ratios of illite versus smectite and kaolinite, and by the illite crystallinity in suites II and IV. Especially the suite IV, which forms mottled muddy sediments that underwent pedogenesis, possibly represents glacial/interglacial cycles during the Mid-Pleistocene climate transition （MPT）. The rare presence of smectite in suite V which formed during the Late Quaternary suggests a significant contribution of fine-grained sediment derived from the upstream of the Yangtze catchment. Such changes in sediment sources are consistent with the evolution of regional sedimentary environments, which evolved towards an open coast/ deltaic setting and imply that the study area became the depositional basin of the Yangtze fine-grained sediment due to the final submergence of the Wu-Nan-Sha and Fukien-Reinan Massifs since the Late Quaternary.