[Construction of CD138-targeted chimeric antigen receptor- modified T cells and their effect in multiple myeloma therapy].

Objective: To construct a novel chimeric antigen receptor T (CAR-T) cell targeting CD138 and to investigate its cytotoxicity against myeloma cells. Methods: The hybridoma strain that can stably secrete the CD138 monoclonal antibody (mAb) was prepared and obtained through monoclonal antibody screening technology. The hybridoma strain cells were intraperitoneally injected into mice to produce ascites containing monoclonal antibodies, which were then collected and purified to obtain pure CD138 mAb. Further examinations were performed to assess the biological characteristics of CD138 mAb. The variable region sequence of this antibody was amplified through reverse transcription polymerase chain reaction and was used as the antigen recognition domain of CD138 CAR, which was subsequently expressed on the surface of T cells by lentiviral infection. Flow cytometry was employed to assess the phenotype of CD138 CAR-T cells. In vitro cytotoxicity and degranulation assays were performed to evaluate their antitumor effects. Results: ① We successfully prepared anti-human CD138 antibody hybridoma cell lines and screened a hybridoma cell strain, 5G2, which could persistently and stably secrete the anti-CD138 antibody. ② The purified CD138 (5G2) mAb can especially recognize CD138(+) cells with a binding affinity constant (K(D)) of 6.011×10(-9) mol/L and showed no significant binding activity with CD138(-) cells. ③The variable region sequence of the CD138 (5G2) antibody was obtained using molecular cloning technology, and CD138 (5G2) CAR was successfully constructed and expressed on T cells through lentivirus infection and, concurrently, demonstrated effective binding to recombinant human CD138 protein.④ The proliferation of T cells transduced with the CD138 (5G2) CAR was highly efficient. The phenotype analysis revealed that CD138 (5G2) CAR-T cells exhibited a greater tendency to differentiate into central memory T cells and memory stem T cells, with a reduced proportion of terminally differentiated effector memory subsets. ⑤CD138 (5G2) CAR-T cells demonstrated specific cytotoxicity against CD138(+) myeloma cell line H929, whereas CD138(-) cell line K562 remained unaffected. The percentage of residual H929 cells was (12.92±8.02) % after co-culturing with CD138 (5G2) CAR-T cells, while (54.25±15.79) % was left in the Vector-T group (E∶T=1∶2; P<0.001). ⑥Results of degranulation assays demonstrated a significant activation of CD138 (5G2) CAR-T cells after co-culture with the H929 cell line, whereas no significant activation was observed in Vector-T cells [ (25.78±3.35) % vs (6.13±1.30) %, P<0.001]. ⑦After co-culturing with CD138(+) cells, CD138 (5G2) CAR-T cells exhibited a significant increase in cytokine secretion compared to the Vector-T group [interleukin-2: (1 697.52±599.05) pg/ml vs (5.07±1.17) pg/ml, P<0.001; interferon-γ: (3 312.20±486.38) pg/ml vs (9.28±1.46) pg/ml, P<0.001; and tumor necrosis factor-α: (1 837.43±640.49) pg/ml vs (8.75±1.65) pg/ml, P<0.001]. However, no significant difference was observed in cytokine secretion levels between the two groups after co-culturing with CD138(-) cells. Conclusion: This study successfully prepared a novel monoclonal antibody against CD138, and CAR-T cells constructed with the antigen recognition domain derived from this 5G2 mAb demonstrated effective antitumor activity against myeloma cells. This can be used as a new option for the detection of the CD138 antigen and proposes a novel strategy for multiple myeloma immunotherapy.

[Different methods in predicting mortality of pediatric intensive care units sepsis in Southwest China].

Objective: To investigate the value of systemic inflammatory response syndrome (SIRS), pediatric sequential organ failure assessment (pSOFA) and pediatric critical illness score (PCIS) in predicting mortality of pediatric sepsis in pediatric intensive care units (PICU) from Southwest China. Methods: This was a prospective multicenter observational study. A total of 447 children with sepsis admitted to 12 PICU in Southwest China from April 2022 to March 2023 were enrolled. Based on the prognosis, the patients were divided into survival group and non-survival group. The physiological parameters of SIRS, pSOFA and PCIS were recorded and scored within 24 h after PICU admission. The general clinical data and some laboratory results were recorded. The area under the curve (AUC) of the receiver operating characteristic curve was used to compare the predictive value of SIRS, pSOFA and PCIS in mortality of pediatric sepsis. Results: Amongst 447 children with sepsis, 260 patients were male and 187 patients were female, aged 2.5 (0.8, 7.0) years, 405 patients were in the survival group and 42 patients were in the non-survival group. 418 patients (93.5%) met the criteria of SIRS, and 440 patients (98.4%) met the criteria of pSOFA≥2. There was no significant difference in the number of items meeting the SIRS criteria between the survival group and the non-survival group (3(2, 4) vs. 3(3, 4) points, Z=1.30, P=0.192). The pSOFA score of the non-survival group was significantly higher than that of the survival group (9(6, 12) vs. 4(3, 7) points, Z=6.56, P<0.001), and the PCIS score was significantly lower than that of the survival group (72(68, 81) vs. 82(76, 88) points, Z=5.90, P<0.001). The predictive value of pSOFA (AUC=0.82) and PCIS (AUC=0.78) for sepsis mortality was significantly higher than that of SIRS (AUC=0.56) (Z=6.59, 4.23, both P<0.001). There was no significant difference between pSOFA and PCIS (Z=1.35, P=0.176). Platelet count, procalcitonin, lactic acid, albumin, creatinine, total bilirubin, activated partial thromboplastin time, prothrombin time and international normalized ratio were all able to predict mortality of sepsis to a certain degree (AUC=0.64, 0.68, 0.80, 0.64, 0.68, 0.60, 0.77, 0.75, 0.76, all P<0.05). Conclusion: Compared with SIRS, both pSOFA and PCIS had better predictive value in the mortality of pediatric sepsis in PICU.

[Research progress on exosomes and exosomal microRNAs in the occurrence and development of diabetic peripheral neuropathy].

Diabetic peripheral neuropathy (DPN) is one of the chronic complications of diabetic neuropathy, and also the main cause of chronic wounds and disability. Exosomes and exosomal-microRNAs (miRNAs) are closely related to DPN and participate in the signal transduction and protein expression of the peripheral nervous system by mediating intercellular communication. However, the specific role and mechanism of EVs and exosomal-miRNAs in the occurrence and development of DPN in high-glucose environments are not fully understood. This article reviews the promotion of EVs and exosomal-miRNAs in the occurrence and development of DPN in inhibiting axon growth, promoting inflammatory response, and inducing vascular injury in a high glucose environment.

[Research progress of Eubacterium and its metabolite short-chain fatty acids in regulating type 2 diabetes mellitus].

Intestinal flora and its metabolites are closely related to the progression of type 2 diabetes mellitus(T2DM). Eubacterium is one of the dominant intestinal flora, and its metabolites short-chain fatty acids (SCFAs) play a leading role in regulating intestinal metabolic balance. It has been reported that SCFAs can regulate the secretion of glucagon-like peptide-1, improve the function of pancreatic ß cells, participate in bile acids metabolism and regulate the production of inflammatory factors in T2DM. Based on the above research background, this article mainly reviews the relationship between Eubacterium and its metabolite SCFAs and T2DM and its regulatory mechanism.

The impact of an annual major recreational boating event on water quality in the Solent Strait.

A long-term historical analysis of the impacts of recreational boating on marine surface water quality during a regatta (Cowes Week) in an internationally crucial waterway, the Solent Strait (Hampshire, UK) is presented. Water quality indicators studied included nitrogen concentration, bacterial indicators, and oxygen saturation, at three sampling sites at/near Cowes during 2001-2019. Findings include that sewage discharge from recreational boats is the key contributor to localised faecal contamination of marine surface waters, putting bathers and shellfisheries at risk. Bathing water quality monitoring and pollution warning systems should be strengthened prior to and during this type of regatta and access to bathing water areas may need to be restricted. These findings have implications for the regulation, future monitoring and management strategies for discharges from recreational boats during extended regattas. Adequate and affordable local facilities for recovering sewage wastewater from recreational boats should be provided alongside appropriate mechanisms for communication to sailors.

[Analysis of FBN1 genemutations in a pedigree with Marfan syndrome].

Mutations in fibrillin-1 (FBN1) were detected in an autosomal dominant Marfan syndrome (MFS) pedigree. The related phenotypes and the significance of mutation screening were discussed. Complete medical and cardiovascular examinations for all pedigree members were performed. Whole exons sequencing (WES) was used to sequence the DNA of the patients and their relatives. The potential pathogenic mutation sites were screened by bioinformatics method. Sanger sequencing was used to verify the mutation sites in the pedigree. The results showed that FBN1 missense mutation was c.6806 T>C in exon 56, resulting in isoleucine being replaced by threonine (p. Ile2269Thr). This mutation has not been reported in Chinese Han population. The occurrence of the mutations strongly correlated with the phenotypes of the patients. The results expand the mutation spectrum of FBN1, and it is helpful to further explore the molecular pathogenesis of MFS and MFS related diseases.

[The molecular mechanism of oxaliplatin-induced peripheral neuropathic pain].

Objective: To investigate the molecular mechanism of oxaliplatin-induced chemotherapy-induced peripheral neuropathic pain (CIPNP). Methods: A total of 16 male Sprague-Dawley rats of specific pathogen-free grade were randomly divided into two groups: oxaliplatin experimental group (2.4 mg/kg oxaliplatin dissolved in 5.0% glucose solution, n=8) and control group (equal volume 5% glucose solution, n=8). The rat model of CIPNP was established by continuous administration with oxaliplatin. In addition, mechanical allodynia, thermal hyperalgesia and cold hyperalgesia were measured and compared between the two groups. To explore the molecular mechanism of oxaliplatin-induced CIPNP, the gene expression of dorsal root ganglia (DRG) from the rat model of CIPNP was analyzed using RNA sequencing (RNA-Seq). Results: Mechanical and thermal hypersensitivity was exhibited on day 7 and a stronger hypersensitivity was observed on day 14. A total of 20 152 genes were quantified by RNA-Seq, and 379 differentially expressed genes (DEGs) were obtained with absolute fold change cut-offs ≥ 2 and P value<0.05. There were 7 genes (Npy, Car3, Cdkn1a, Nts, Prc1, Ms4a7 and Ecel1) that were involved in peripheral nerve injury-related neuropathic pain. Gene ontology (GO) functional enrichment analyses indicated that the DEGs induced by oxaliplatin were involved in oxygen transport, cell division, intermediate, centromere, oxygen transporter activity, oxygen binding. Moreover, the result of Kyoto Encyclopedia of genes and genomes (KEGG) analyses highlighted that the DEGs induced by oxaliplatin were involved in malaria, African trypanosomiasis, primary immunodeficiency, peroxisome proliferator activated receptor (PPAR) signaling pathway. Conclusion: Oxaliplatin induces CIPNP via pain-related genes and signaling pathways.

[Construction of a new anti-CD123 chimeric antigen receptor T cells and effect of anti-acute myeloid leukemia].

Objective: To construct a new CD123- specific chimeric antigen receptor in order to provide a foundation for immunotherapy of CD123 positive leukemia. Methods: A hybridoma strain (6E11) capable of stably secreting CD123 antibody was obtained by a monoclonal screening technique, and the hybridoma cells were expanded and injected intraperitoneally to the pretreated Balb/c mice. Ascites was collected and purified to obtain the monoclonal antibody (mAb) . The affinity and specificity of 6E11 mAb were measured. The variable regions of the heavy and light chains of the 6E11 mAb were cloned by RT-PCR from the 6E11 mouse hybridoma. We generated a new CD123 specific chimeric antigen receptor with a scFv fragment derived from 6E11 antibody, designated as 6E11 CAR. T cells were transduced with lentiviral supernatant from 293T cells transfected with 6E11 CAR plasmid to generate 6E11 CAR-T cells. The specific cytotoxicity of 6E11 CAR-T against CD123(+) acute myeloid leukemia (AML) cell lines and primary AML cells in vitro were evaluated by co-culture experiments, degranulation experiments and cytokine releasing assay. Results: ① A hybridoma cell line 6E11 stably secreting anti-human CD123 antibody was developed and its variable region sequences were obtained. ② The 6E11 mAb has high affinity for CD123 protein (Kd value: 2.1 nmol/L) . The 6E11 mAb specifically recognizes CD123(+) cell line THP-1 cells and does not respond to CD123(-) cell line Jurkat cells. ③ 6E11 CAR-T cells were successfully generated with a CAR expression rate higher than 60%. ④ 6E11 CAR-T cells could specifically kill CD123(+) MV4-11 cell line but had no killing effect on the CD123(-) K562 cell line. Compared with vector-T cells, 6E11 CAR-T cells have higher killing rate to MV4-11 cells[ (98.60±1.20) %vs (20.28±6.74) %, P<0.001]. ⑤ MV4-11 cells activated 6E11 CAR-T cells significantly but not Vector-T cells[ (26.33±3.30) %vs (1.17±0.06) %, P<0.001]. ⑥ 6E11 CAR-T cells released more cytokines than vector-T cells when co-cultured with MV4-11[IL-2: (92.90±1.51) pg/ml vs (6.05±3.41) pg/ml, P<0.001; TNF-α: (1 407.20±91.95) pg/ml vs (7.86±0.85) pg/ml, P<0.001; IFN-γ: (5 614.60±170.17) pg/ml vs (8.42±2.70) pg/ml, P<0.001]. The IFN-γ, IL-2 and TNF-α in the 6E11 CAR-T group were similar to those in the Vector-T group when co-cultured with K562. ⑦ 6E11 CAR-T cells could be activated by bone marrow mononuclear cells (BMMNC) derived from CD123(+) AML patients and effectively kill these BMMNC cells from CD123(+) AML patients. Conclusion: 6E11 hybridoma cell line can stably secrete highly specific monoclonal antibodies against human CD123, which can be used to detect the expression of human CD123. It can also be used to target human CD123 protein in tumor immunotherapy. CD123 CAR-T cells with 6E11 Ig variable region sequence have specific anti-leukemic activity in vitro, which may provide a new option for further clinical research of AML.

Developing Children's Oral Health Assessment Toolkits Using Machine Learning Algorithm.

OBJECTIVES: Evaluating children's oral health status and treatment needs is challenging. We aim to build oral health assessment toolkits to predict Children's Oral Health Status Index (COHSI) score and referral for treatment needs (RFTN) of oral health. Parent and Child toolkits consist of short-form survey items (12 for children and 8 for parents) with and without children's demographic information (7 questions) to predict the child's oral health status and need for treatment. METHODS: Data were collected from 12 dental practices in Los Angeles County from 2015 to 2016. We predicted COHSI score and RFTN using random Bootstrap samples with manually introduced Gaussian noise together with machine learning algorithms, such as Extreme Gradient Boosting and Naive Bayesian algorithms (using R). The toolkits predicted the probability of treatment needs and the COHSI score with percentile (ranking). The performance of the toolkits was evaluated internally and externally by residual mean square error (RMSE), correlation, sensitivity and specificity. RESULTS: The toolkits were developed based on survey responses from 545 families with children aged 2 to 17 y. The sensitivity and specificity for predicting RFTN were 93% and 49% respectively with the external data. The correlation(s) between predicted and clinically determined COHSI was 0.88 (and 0.91 for its percentile). The RMSEs of the COHSI toolkit were 4.2 for COHSI (and 1.3 for its percentile). CONCLUSIONS: Survey responses from children and their parents/guardians are predictive for clinical outcomes. The toolkits can be used by oral health programs at baseline among school populations. The toolkits can also be used to quantify differences between pre- and post-dental care program implementation. The toolkits' predicted oral health scores can be used to stratify samples in oral health research. KNOWLEDGE TRANSFER STATEMENT: This study creates the oral health toolkits that combine self- and proxy- reported short forms with children's demographic characteristics to predict children's oral health and treatment needs using Machine Learning algorithms. The toolkits can be used by oral health programs at baseline among school populations to quantify differences between pre and post dental care program implementation. The toolkits can also be used to stratify samples according to the treatment needs and oral health status.

Molecular cloning and functional characterisation of duck (Anas platyrhynchos) tumour necrosis factor receptor-associated factor 3.

1. Tumour necrosis factor receptor-associated factor 3 (TRAF3) is a key regulator of innate immunity and acquired immunity, and has a salient anti-viral role. 2. In this experiment, the duck TRAF3 (DuTRAF3) gene was cloned according to the Anas platyrhynchos TRAF3 sequence to explore its function. The TRAF3 open reading frame contains 1704 bp that encode a protein of 567 amino acids, which contain a RING finger domain, two zinc finger motifs, a coiled-coil region, and a MATH domain. 3. Reverse transcription-polymerase chain reaction showed that DuTRAF3 was expressed in all the examined tissues, with a comparatively higher expression in the spleen and brain tissues. 4. In HEK293T cells, DuTRAF3 overexpression resulted in a significantly increased NF-κB activity and interferon (IFN)-ß promoter activation. 5. Following resiquimod (R848) and poly(I:C) stimulation of duck peripheral blood mononuclear cells (PBMCs), the expressions of TRAF3 and IFN-ß were significantly upregulated; in addition, following R848 stimulation, the mRNA levels of IL-6, IL-8 and IL-10 were also significantly upregulated. After infection with the Newcastle Disease Virus LaSota vaccine strain, the mRNA levels of IL-6 and IL-10 were significantly upregulated, while that of TRAF3 was downregulated. 6. These results suggest that DuTRAF3 has an important role to play in innate antiviral immune responses.

Child and Parent Demographic Characteristics and Oral Health Perceptions Associated with Clinically Measured Oral Health.

OBJECTIVE: To examine child and parent reports about the child's oral health and assess the associations of these reports with clinical assessments of oral health status by dental examiners. METHODS: Surveys with 139 items for children and 133 items for parents were administered by Audio Computer-Assisted Self-Interview Software. In addition, the Children's Oral Health Status Index (COHSI) was computed from a dental examination. RESULTS: A total of 334 families with children ages 8 to 17 y participated at 12 dental practices in Los Angeles County. Ordinary least squares regression models were estimated separately for child and parent surveys to identify items uniquely associated with the COHSI. Ten of 139 items the children reported regarding their oral health were associated with the COHSI. The strongest associations were found for child's age, aesthetic factors (straight teeth and pleased with teeth), and cognitive factors related to perception of dental appearance (pleased/happy with the look of the child's mouth, teeth, and jaws). Nine of 133 parent items about the child's oral health were associated with the COHSI in the parent model, notably being a single parent, parent's gender, parent born in the United States, pleased or happy with the look of their child's teeth, and accessing the Internet. CONCLUSION: These child and parent survey items have potential to be used to assess oral health status for groups of children in programs and practices in lieu of dental screenings. KNOWLEDGE TRANSLATION STATEMENT: The paper's results inform the development of a toolkit that can be used by schools, public health agencies, and dental programs to identify children with low oral health status based on parents' and children's responses to survey items across demographic, physical, mental, and social domains. These survey items can be used to inform parents of the desirability of proactively addressing inadequacies in their child's oral health status, enabling them to more rationally address dental needs.

Mediation of inflammation, obesity and fatty liver disease by advanced glycation endoproducts.

OBJECTIVE: Fatty liver may induce various complications including chronic hepatitis or liver cirrhosis, and is frequently occurred in obesity individuals. Advanced glycosylation end products (AGEs) were known to play a critical role in multiple liver diseases. This study, therefore, aimed to study the effect of AGEs on obesity, related liver cirrhosis and inflammation, on an obesity fatty liver rat model. MATERIALS AND METHODS: A total of 60 Sprague Dawley (SD) rats were randomly divided into control, model and AGEs inhibitor groups (n=20 each). AGEs level, body weight and liver function were examined in each animal, followed by hematoxylin-eosin (HE) staining to detect the pathological change of liver. Further Real-time PCR and enzyme-linked immunosorbent assay (ELISA) were employed to detect inflammatory cytokine levels including tumor necrosis factor (TNF)-α and interleukin (IL)-6. RESULTS: AGEs level was significantly elevated in obesity fatty liver model rats, which also had higher total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL-C) and high-density lipoprotein (HDL-C) levels, along with deteriorated liver function and higher TNF-α and IL-6 levels. The application of AGEs inhibitor aminoguanidine significantly improved liver functions and lower TNF-α or IL-6 levels when compared to the model group (p<0.05 in all cases). CONCLUSIONS: Obesity fatty liver can promote AGEs level, further causing pathological changes and increased secretion of inflammatory cytokines. The inhibition of AGEs can improve the metabolism of fatty acids, decrease inflammatory cytokines and benefit the treatment of obesity fatty liver.

[The expression of IL-22 in nasal polyps tissues].

Objective:To analyze the expression of IL-22 in nasal polyps and the expression of Th22 cells. Method:The concentrations of IL-22 in nasal polyps were determined by ELISA. The mononuclear cells infiltrated in nasal polyps were separated and flow cytometry was used to analyze the expression of IL-22 in CD4+ T cells and the counts of Th22 cells. Result:Compared with the control group, the expression of IL-22 in nasal polyps did not change significantly, however the expression of IL-22 in CD4+ T cells increased. Furthermore the number of Th22 cells in the tissue increased significantly. Conclusion:The expression of Th22 cells in nasal polyps is significantly increased, which may play an important role in local chronic inflammatory mucosal immunity.

An let-7 KRAS rs712 polymorphism increases hepatocellular carcinoma risk.

KRAS, also known as V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog, acts as an intracellular signal transducer. The oncogenic KRAS mutation is an essential step in the development of many types of human cancers, including hepatocellular carcinoma. Here we aimed to investigate the relationship between KRAS rs712 polymorphisms and hepatocellular carcinoma susceptibility. Five-hundred-and-fourteen participants were enrolled in a case-control study (262 cases and 252 normal subjects). The variants were distinguished using polymerase chain reaction-restriction fragment length polymorphism. Significantly increased HCC risk was observed to be associated with the T allele of the rs712 locus (P = 0.049, OR = 1.35, 95%CI = 1.01-1.78). Further, HCC risk with the GT genotype (P = 0.015, OR = 1.64, 95%CI = 1.08-2.50) and the TT genotype (P = 0.015, OR = 2.56, 95%CI = 1.05-6.25) in a codominant model was significantly higher than that with the GG genotype. In a dominant model, significantly increased HCC susceptibility was also associated with T allele carriers (P = 0.006, OR = 1.75, 95%CI = 1.16-2.63). Moreover, we found that the frequency of the KRAS rs712 TT genotype was significantly higher in HBV-positive HCC patients than in HBV-negative HCC patients.

Inhibitory effects of indirubin derivative PHII-7 on invasion and migration in metastatic cancer.

UNLABELLED: PHII-7, a derivative of indirubin, showed significant anti-cancer activities in vivo and in vitro. We asked whether treating human metastatic cancers and multidrug resistant cancer with PHII-7 would inhibit their invasion and migration. Cell growth was tested by MTT assay and colony formation assay. Apoptosis was examined by flow cytometry. Transwell-based assay and wound healing assay were used to examine cell invasion and migration. Real-time PCR assay and western blot assay were performed to test gene expression on mRNA and protein level, respectively. Firstly, we confirmed that MCF-7/ADR cells showed more invasive and migratory properties compared with MCF-7 cells which were associated with several EMT markers, such as E-cadherin, Slug and vimentin. Secondly, we found that slightly toxic doses of PHII-7 decreased the number of cells that invaded a model epithelial basement membrane and that migrated by switching the molecular signature of the cells from mesenchymal to epithelial. And PHII-7 significantly regulated expression of several epithelial-mesenchymal transition (EMT)-related genes, including E-cadherin, Slug, ß-catenin and vimentin. Thirdly, compared with control, PHII-7 inhibited cell proliferation in a time- and dose-dependent manner. Higher doses of PHII-7 also induced apoptosis through activating PARP, caspase-9 and caspase-3. PHII-7 significantly inhibited invasion and migration in both metastatic cancers and multidrug resistant cancer. Our results may provide several data for future application of PHII-7 on drug design and patients treatment. KEYWORDS: PHII-7, invasion, migration, multidrug resistance, epithelial-mesenchymal transition.

Soil organic carbon stock and distribution in cultivated land converted to grassland in a subtropical region of China.

Land-use change from one type to another affects soil carbon (C) stocks which is associated with fluxes of CO2 to the atmosphere. The 10-years converted land selected from previously cultivated land in hilly areas of Sichuan, China was studied to understand the effects of land-use conversion on soil organic casrbon (SOC) sequestration under landscape position influences in a subtropical region of China. The SOC concentrations of the surface soil were greater (P\0.001) for converted soils than those for cultivated soils but lower (P\0.001) than those for original uncultivated soils. The SOC inventories (1.90­1.95 kg m-2) in the 0­15 cm surface soils were similar among upper, middle, and lower slope positions on the converted land, while the SOC inventories (1.41­1.65 kg m-2) in this soil layer tended to increase from upper to lower slope positions on the cultivated slope. On the whole, SOC inventories in this soil layer significantly increased following the conversion from cultivated land to grassland (P\0.001). In the upper slope positions, converted soils (especially in 0­5 cm surface soil) exhibited a higher C/N ratio than cultivated soils (P = 0.012), implying that strong SOC sequestration characteristics exist in upper slope areas where severe soil erosion occurred before land conversion. It is suggested that landscape position impacts on the SOC spatial distribution become insignificant after the conversion of cultivated land to grassland, which is conducive to the immobilization of organic C. We speculate that the conversion of cultivated land to grassland would markedly increase SOC stocks in soil and would especially improve the potential for SOC sequestration in the surface soil over a moderate period of time (10 years).

The miR-106b~25 cluster promotes bypass of doxorubicin-induced senescence and increase in motility and invasion by targeting the E-cadherin transcriptional activator EP300.

Resistance to chemotherapeutic treatment, which is indirectly responsible for many cancer deaths, is normally associated with an aggressive phenotype including increased cell motility and acquisition of invasive properties. Here we describe how breast cancer cells overcome doxorubicin-induced senescence and become drug resistant by overexpression of the microRNA (miR)-106b~25 cluster. Although all three miRs in the cluster contribute to the generation of doxorubicin resistance, miR-25 is the major contributor to this phenotype. All three miRs in this cluster target EP300, a transcriptional activator of E-cadherin, resulting in cells acquiring a phenotype characteristic of cells undergoing epithelial-to-mesenchymal transition (EMT), including an increase in both cell motility and invasion, as well as the ability to proliferate after treatment with doxorubicin. These findings provide a novel drug resistance/EMT regulatory pathway controlled by the miR-106b~25 cluster by targeting a transcriptional activator of E-cadherin.