CircINTS4 Facilitates Chemoresistance of TNBC by Competitively Binding miR-129-5p/POM121 Axis.

Objectives: To detect the expression of circular RNA (circRNA) circINTS4 in triple-negative breast cancer (TNBC) and to analyze the relationship between the expression of circRNA circINTS4 and the clinicopathological characteristics and chemotherapy resistance of patients with TNBC. Methods: Bioinformatics was used to predict that circINTS4 and POM121 could bind to miR-129-5p, and dual luciferase reporter genes proved that circINTS4 could bind to miR-129-5p and miR-129-5p could bind to POM121. RNA immunoprecipitation (RIP) and RNA pull-down experiments confirmed that circINTS4 binds to miR-129-5p. The correlation among circINTS4, miR-129-5p, and POM121 was detected by qRT-PCR. Results: In ADR-resistant TNB cells, circINTS4 was significantly up-regulated, miR-129-5p was down-regulated, and POM121 protein expression was significantly up-regulated. Experimental results showed that circINTS4 knockdown inhibited proliferation, migration, invasion, and autophagy. Knocking down miR-129-5p or overexpression of POM121 reversed the inhibitory effect of sh-circints4 on the development of ADR-resistant TNBC cells. In addition, CIRCINTS4 regulates POM121 expression by sponge-adsorbed miR-129-5p. CIRCINTS4 knockdown prevents ADR-resistant tumor growth by regulating the miR-129-5p/POM121 axis in vivo. Conclusions: CircRNA circINTS4 may act as the ceRNA of miR-129-5p to regulate the expression of target gene POM121, thereby promoting the progress of TNBC molecular mechanism and providing scientific basis for circINTS4 as a new molecular target for clinical diagnosis and drug resistance therapy of TNBC.

Arbuscular mycorrhizal fungal diversity, root colonization, and soil alkaline phosphatase activity in response to maize-wheat rotation and no-tillage in North China.

Monitoring the effects of no-tillage (NT) in comparison with conventional tillage (CT) on soil microbes could improve our understanding of soil biochemical processes and thus help us to develop sound management strategies. The objective of this study was to compare the species composition and ecological function of soil arbuscular mycorrhizal (AM) fungi during the growth and rotation of crops under NT and CT. From late June 2009 to early June 2010, 32 topsoil (0-15 cm) samples from four individual plots per treatment (CT and NT) were collected at both the jointing and maturation stages of maize (Zea mays L.) and wheat (Triticum aestivum L.) from a long-term experimental field that was established in an Aquic Inceptisol in North China in June 2006. The AM fungal spores were isolated and identified and then used to calculate species diversity indices, including the Shannon- Wiener index (H'), Evenness (E), and Simpson's index (D). The root mycorrhizal colonization and soil alkaline phosphatase activity were also determined. A total of 34 species of AM fungi within nine genera were recorded. Compared with NT, CT negatively affected the soil AM fungal community at the maize sowing stage, leading to decreases in the average diversity indices (from 2.12, 0.79, and 0.82 to 1.79, 0.72, and 0.74 for H', E, and D, respectively), root mycorrhizal colonization (from 28% to 20%), soil alkaline phosphatase activity (from 0.24 to 0.19 mg/g/24 h) and available phosphorus concentration (from 17.4 to 10.5 mg/kg) at the maize jointing stage. However, reductions in diversity indices of H', E, and D were restored to 2.20, 0.81, and 0.84, respectively, at the maize maturation stage. CT should affect the community again at the wheat sowing stage; however, a similar restoration in the species diversity of AM fungi was completed before the wheat jointing stage, and the highest Jaccard index (0.800) for similarity in the species composition of soil AM fungi between CT and NT was recorded at the wheat maturation stage. Our results also demonstrated that NT resulted in the positive protection of the community structure of AM fungi and played an important role in maintaining their functionality especially for maize seedlings.

[Infusion of ex vivo expanded homologous CD4⁺;CD25⁺; regulatory T cells promotes the susceptibility to tumor in mice].

OBJECTIVE: To study the effects of adoptive transfer of ex vivo expanded homologous CD4⁺;CD25⁺; regulatory T cells (Tregs) on antitumor immunity in mice and explore the potential risk of this therapeutic method. METHODS: Marine CD4⁺;CD25⁺; Tregs were separated from spleens by magnetic activated cell sorting (MACS) and expanded by anti-CD3/CD28-coated microbeads and 1 000 U/mL interleukin 2 (IL-2) in vitro. The purity of fresh and expanded Tregs was determined by FACS. The cells were collected after two rounds of expansion (7 days each), and suppressive activity of expanded Tregs was tested by the mixed lymphocyte reaction (MLR) in vitro. Thereafter, the BALB/c mice were intravenously injected with 1 × 107 expanded Tregs and 24 hours later, they were inoculated intravenously with 1 × 106; B16;F10; tumor cells. The mice injected with tumor cells only were set as the control group. Fourteen days later, the percentage of CD4⁺;CD25⁺;Foxp3⁺; Tregs in peripheral blood was analyzed by flow cytometry and the numbers of pulmonary metastases were counted. Results The purity of expanded Tregs decreased from (96.3 ± 2.88)% to (87.73 ± 2.35)% compared with fresh Tregs, but there was no significant difference in the suppressive activity between fresh Tregs and expanded Tregs (P>0.05). The number of tumor nodules in lung of BALB/c mice was significantly elevated from 14 ± 5 to 73 ± 9 after injected 1 × 107; expanded Tregs compared with the control group (P=0.007), and the same with the mice that were inoculated with 2 × 106; B16;F10; cells alone (P=0.230). What's more, the number of pulmonary metastases was significantly raised from 70 ± 15 to over 300 (P<0.01) in 5 × 105; B16;F10; inoculated C57BL/6 mice if they were injected previously with 8 × 106; expanded Tregs. The percentage of Foxp3⁺; Tregs in peripheral blood significantly increased in the experimental group as compared with normal mice and control group (P<0.05). Conclusion Adoptive transfer of ex vivo expanded Tregs can induce the immune tolerance and inhibit the antitumor immunity at the same time. There was a potential risk in the clinical application of Tregs.

Arbuscular mycorrhizal fungus enhances P acquisition of wheat (Triticum aestivum L.) in a sandy loam soil with long-term inorganic fertilization regime.

The P efficiency, crop yield, and response of wheat to arbuscular mycorrhizal fungus (AMF) Glomus caledonium were tested in an experimental field with long-term (19 years) fertilizer management. The experiment included five fertilizer treatments: organic amendment (OA), half organic amendment plus half mineral fertilizer (1/2 OM), mineral fertilizer NPK, mineral fertilizer NK, and the control (without fertilization). AMF inoculation responsiveness (MIR) of wheat plants at acquiring P were estimated by comparing plants grown in unsterilized soil inoculated with G. caledonium and in untreated soil containing indigenous AMF. Without AMF inoculation, higher crop yields but lower colonization rates were observed in the NPK and two OA-inputted treatments, and NPK had significantly (P < 0.05) lower impacts on organic C and available P in soils and thereby P acquisition of wheat plants compared with OA and 1/2 OM. G. caledonium inoculation significantly (P < 0.05) increased colonization rates with the NPK and two P-deficient treatments but significantly (P < 0.05) increased vegetative biomass, crop yield, and P acquisition of wheat as well as soil alkaline phosphatase (ALP) activity, only with the NPK treatment. This gave an MIR of ca. 45% on total P acquisition of wheat plants. There were no other remarkable MIRs. It suggested that the MIR is determined by soil available P status, and rational combination of AMF with chemical NPK fertilizer can compensate for organic amendments by improving P-acquisition efficiency in arable soils.