Description: Lymph node (LN) metastasis is commonly associated with systemic distant organ metastasis in human breast cancer and is an important prognostic predictor for survival of breast cancer patients. However, whether tumor-draining LNs (TDLNs) play a significant role in modulating the malignancy of cancer cells for distant metastasis remains controversial. Using a syngeneic mouse mammary tumor model, we found that breast tumor cells derived from TDLN have higher malignancy and removal of TDLNs significantly reduced distant metastasis. Up-regulation of oncogenic Il-17rb in cancer cells derived from TDLNs contributes to their malignancy. TGF-β1 secreted from regulatory T cells (Tregs) in the TDLNs mediated the up-regulation of Il-17rb through downstream Smad2/3/4 signaling. These phenotypes can be abolished by TGF-β1 neutralization or depletion of Tregs. Consistently, clinical data showed that the up-regulation of IL-17RB in cancer cells from LN metastases correlated with the increased prevalence of Tregs as well as the aggressive growth of tumors in mouse xenograft assay. Together, these results indicate that Tregs in TDLNs play an important role in modulating the malignancy of breast cancer cells for distant metastasis. Blocking IL-17RB expression could therefore be a potential approach to curb the process. Treg-secreted TGF-β1 in the tumor-draining LN (TDLN) microenvironment up-regulates IL-17RB expression in breast cancer cells, thereby enhancing their metastatic potential.

Description: A series of confirmed and suspected dammed palaeo-lake sedimentary successions is scattered within the middle Yarlung Tsangpo valley in Tibet. However, the chronology, the genesis of the dam and its location, the water level of the dammed lake, the process of dam failure and the spatiotemporal relationships between the sedimentary successions remain controversial. Here, we focus on one sedimentary succession of the suspected dammed palaeo-lake at Xigazê. We measured the grain-size distribution, magnetic susceptibility, organic and inorganic carbon content, and δ 13 C org and δ 15 N total ratios of the sediments. In addition, we measured the δ 18 O shell and δ 13 C shell values of modern and fossil Radix sp. shells, and the δ 18 O water and δ 13 C DIC values of the ambient water with different hydrological regimes. The results indicate that the δ 18 O shell values of modern Radix sp. and the δ 18 O water of the ambient water body significantly depend on its hydrological status. In addition, a strong positive relationship was observed between δ 18 O shell values of modern Radix sp. shells and the δ 18 O water of the ambient water on the Tibetan Plateau. According to this correlation, the δ 18 O water values of the palaeo-water body are reconstructed using the δ 18 O shell values of Radix sp. fossil shells in the Xigazê section. Further, based on the δ 18 O shell values of fossil Radix sp., the reconstructed δ 18 O water of the palaeo-water body and the specific habitats of Radix sp., we infer that the sedimentary succession in the Xigazê broad valley was mainly formed within the backwater terminal zone of a dammed palaeo-lake and that the elevation of the water level of the lake was approximately 3811 m a.s.l. AMS 14 C dating indicates that the deposits of the dammed palaeo-lake were formed at about 33–22 cal. ka BP. Finally, the presence of Radix sp. fossil shells within the Xigazê section suggests that Radix sp. survived the late Last Glacial Period on the Tibetan Plateau.

Description: A multi-drug resistant Escherichia coli C21 was isolated from a chicken in China. It was shown to be positive for the presence of the bla TEM-1 , bla CTX-M-55 and rmtB genes by PCR. This strain was examined by phylogenetic grouping, conjugation experiments, plasmid analysis, PCR-based replicon typing and multi-locus sequence typed (MLST). The genetic environment of bla CTX-M-55 was investigated by PCR mapping. The strain belonged to phylogroup A, ST156. The bla CTX-M-55 and rmtB genes were found to be present in separate plasmids that belonged to the IncI1 and IncN families, respectively. These antibiotic-resistant plasmids could be transferred to the recipient strain alone or together. A new arrangement of IS Ecp1 Δ-IS 1294- ΔIS Ecp1-bla CTX-M-55 -ORF 477 , in which the IS Ecp1 element was disrupted by another IS 1294 element, was identified initially. Conjugative transfer and IS elements found in this study could lead to the rapid dissemination of bla CTX-M-55 and rmtB among strains of Enterobacteriaceae , which could pose a threat to animal husbandry and public health.