miR-155 increases stemness and decitabine resistance in triple-negative breast cancer cells by inhibiting TSPAN5

Effective therapeutic targets for triple-negative breast cancer (TNBC), a special type of breast cancer (BC) with rapid metastasis and poor prognosis, are lacking, especially for patients with chemotherapy resistance. Decitabine (DCA) is a Food and Drug Administration-approved DNA methyltransferase inhibitor that has been proven effective for the treatment of tumors. However, its antitumor effect in cancer cells is limited by multidrug resistance. Cancer stem cells (CSCs), which are thought to act as seeds during tumor formation, regulate tumorigenesis, metastasis, and drug resistance through complex signaling. Our previous study found that miR-155 is upregulated in BC, but whether and how miR-155 regulates DCA resistance is unclear. In this study, we demonstrated that miR-155 was upregulated in CD24⁻CD44⁺ BC stem cells (BCSCs). In addition, the overexpression of miR-155 increased the number of CD24⁻CD44⁺ CSCs, DCA resistance and tumor clone formation in MDA-231 and BT-549 BC cells, and knockdown of miR-155 inhibited DCA resistance and stemness in BCSCs in vitro. Moreover, miR-155 induced stemness and DCA resistance by inhibiting the direct target gene tetraspanin-5 (TSPAN5). We further confirmed that overexpression of TSPAN5 abrogated the effect of miR-155 in promoting stemness and DCA resistance in BC cells. Our data show that miR-155 increases stemness and DCA resistance in BC cells by targeting TSPAN5. These data provide a therapeutic strategy and mechanistic basis for future possible clinical applications targeting the miR-155/TSPAN5 signaling axis in the treatment of TNBC.     

Decision-support models for empiric antibiotic selection in Gram-negative bloodstream infections

Objectives

Early empiric antibiotic therapy in patients can improve clinical outcomes in Gram-negative bacteraemia. However, the widespread prevalence of antibiotic-resistant pathogens compromises our ability to provide adequate therapy while minimizing use of broad antibiotics. We sought to determine whether readily available electronic medical record data could be used to develop predictive models for decision support in Gram-negative bacteraemia.

口腔感染的病原菌分布及药敏情况调查分析

目的分析口腔感染患者病原菌分布及药敏情况,为临床合理用药提供参考。方法选取口腔感染患者86例作为研究对象,收集口腔分泌物进行病原菌培养,并行药敏实验。结果本组86例患者中,≤15岁、≥56岁口腔感染患者比例较高,分别占30.2%、40.7%。共检出病原菌351株,其中厌氧菌236株,占67.2%,其在厌氧菌中黑色素普氏菌比例最高(50.4%),其次为口腔链球菌(16.5%);需氧菌115株,占32.8%。对苯唑西林、头孢唑肟、庆大霉素、环丙沙星的耐药较高,分别为49.2%、46.6%、42.0%、40.2%;对万古霉素、四环素、头孢曲松的敏感性较高,分别为98.3%、95.8%、93.6%。结论厌氧菌是口腔感染较为常见的菌种,可选用万古霉素、四环素、头孢曲松等敏感性高的药物治疗。