Bacterial Etiology and Antimicrobial Resistance Pattern of Pediatric Bloodstream Infections in Beijing, 2015-2019.

Purpose: Bloodstream infections (BSIs) was an essential cause of morbidity and mortality in children. Empiric broad-spectrum treatment of BSIs may be costly and unable to effectively eliminate the correct pathogenic microbes, resulting in downstream antimicrobial resistance. The purpose was to provide evidence for diagnosis and treatment of bloodstream infections in pediatrics, by revealing the pathogen distribution and antibiotic resistance pattern of BSIs. Methods: In this 5-year study, a total of 2544 pathogenic bacteria stains, isolated from 2368 patients with BSI, were retrospectively analyzed, to define the species distribution and the antimicrobial resistance pattern in Beijing. Results: The most frequently isolated pathogenic bacteria were K. pneumoniae (12.1%), S. aureus (11.5%), E. coli (11.2%), and E. faecium (11.2%). Hematological malignancies were the most common disease among patients with underlying conditions. Methicillin resistance was detected in 30.0% of S. aureus and 81.7% of coagulase-negative Staphylococcus (CoNS), respectively. The detection rates of carbapenem-resistant-E. coli (CRECO) and carbapenem-resistant-K. pneumoniae (CRKPN) were 10.8% and 50.8%, respectively. In terms of 122 isolates of S. pneumonia, 5 isolates (4.1%) were penicillin-resistant Streptococcus pneumoniae (PRSP); meanwhile, 50 isolates (41.0%) were penicillin-intermediate Streptococcus pneumoniae (PISP). Among the non-fermentative gram-negative bacilli isolates, 22.8% and 26.9% of the P. aeruginosa, were resistant to imipenem and meropenem. Furthermore, the resistance rates of A. baumannii to imipenem and meropenem both were 54.5%. Conclusion: In the study, we demonstrated the characteristics of bloodstream infections and antimicrobial susceptibility pattern of pediatrics in Beijing. Gram positive bacteria were the main pathogens of BSIs. CoNS strains presented even higher resistance to multiple antibiotics, including methicillin, than S. aureus. K. pneumoniae and E. coli represent the most common isolated gram-negative bacteria and exhibited high resistance to a variety of antimicrobial agents. Therefore, it was of critical importance to implement appropriate antimicrobial medication according to pathogen distribution and drug susceptibility test.

Characterization of N-Terminal Asparagine Deamidation and Clipping of a Monoclonal Antibody.

This study presents a novel degradation pathway of a human immunoglobulin G (IgG) molecule featuring a light chain N-terminal asparagine. We thoroughly characterize this pathway and investigate its charge profiles using cation exchange chromatography (CEX) and capillary isoelectric focusing (cIEF). Beyond the well-documented asparagine deamidation into isoaspartic acid, aspartic acid, and succinimide intermediate, a previously unreported clipping degradation pathway is uncovered. This newly identified clipped N-terminal IgG variant exhibits a delayed elution in CEX, categorized as a "basic variant", while retaining the same main peak isoelectric point (pI) in cIEF. The influence of temperature and pH on N-terminal asparagine stability is assessed across various stressed conditions. A notable correlation between deamidation percentage and clipped products is established, suggesting a potential hydrolytic chemical reaction underlying the clipping process. Furthermore, the impact of N-terminal asparagine modifications on potency is evaluated through ELISA binding assays, revealing minimal effects on binding affinity. Sequence alignment reveals homology to a human IgG with the germline gene from Immunoglobulin Lambda Variable 6-57 (IGLV6-57), which has implications for amyloid light-chain (AL) amyloidosis. This discovery of the N-terminal clipping degradation pathway contributes to our understanding of immunoglobulin light chain misfolding and amyloid fibril deposition under physiological conditions.

FARSB serves as a novel hypomethylated and immune cell infiltration related prognostic biomarker in hepatocellular carcinoma.

PURPOSE: Hepatocellular carcinoma (HCC) is a prevalent tumor with high morbidity, and an unfavourable prognosis. FARSB is an aminoacyl tRNA synthase, and plays a key role in protein synthesis in cells. Furthermore, previous reports have indicated that FARSB is overexpressed in gastric tumor tissues and is associated with a poor prognosis and tumorigenesis. However, the function of FARSB in HCC has not been studied. RESULTS: The results showed that FARSB mRNA and protein levels were upregulated in HCC and were closely related to many clinicopathological characteristics. Besides, according to multivariate Cox analysis, high FARSB expression was linked with a shorter survival time in HCC and may be an independent prognostic factor. In addition, the FARSB promoter methylation level was negatively associated with the expression of FARSB. Furthermore, enrichment analysis showed that FARSB was related to the cell cycle. And TIMER analysis revealed that the FARSB expression was closely linked to tumor purity and immune cell infiltration. The TCGA and ICGC data analysis suggested that FARSB expression is greatly related to m6A modifier related genes. Potential FARSB-related ceRNA regulatory networks were also constructed. What's more, based on the FARSB-protein interaction network, molecular docking models of FARSB and RPLP1 were constructed. Finally, drug susceptibility testing revealed that FARSB was susceptible to 38 different drugs or small molecules. CONCLUSIONS: FARSB can serve as a prognostic biomarker for HCC and provide clues about immune infiltration, and m6A modification.

A Retrospective Study of the Use of Antibiotic Lock Therapy and Cluster Nursing Management in Infections in Children with Short Bowel Syndrome or Solid Abdominal Tumours Treated with Totally Implantable Venous Access Ports.

Objective: To explore the effective response strategies for infections in infants with short bowel syndrome and solid abdominal tumours, treated with totally implantable venous access ports (TIVAPs). Methods: A total of 210 children who were treated with a TIVAP in our department from 2020 to 2021 were selected for this retrospective study. Eight of these children diagnosed with a catheter-related bloodstream infection were studied in this study; antibiotic lock therapy (ALT) and cluster nursing management were used for treatment, and their effects on the infection outcome were observed. Results: Among the eight children, seven access ports were successfully protected, and one catheter was removed from the right chest wall port due to repeated infection. In this one child, the left side was re-implanted. Conclusion: The use of the ALT combined with cluster-based nursing can better treat infections of TIVAPs, improve the children's healing time, and has important clinical significance in the prevention of complications from the infection and improving the treatment and nursing of the patients diagnosed with these infections.

The antagonistic potential of peanut endophytic bacteria against Sclerotium rolfsii causing stem rot.

Peanut stem rot caused by Sclerotium rolfsii Sacc. is the most common disease of peanut worldwide and has become increasingly serious in recent years. This study is aimed at obtaining peanut endophytic bacteria with high antagonistic/protective effects against peanut stem rot. In total, 45 bacterial strains were isolated from healthy peanut plants from a severely impacted area. Of these, 6 exhibited antagonistic activity against S. rolfsii, including F-1 and R-11 with the most robust activity with an inhibition zone width of 20.25 and 15.49 mm, respectively. These two were identified as Bacillus sp. and Burkholderia sp., respectively, based on morphological, physiological, and biochemical characteristics and 16S rDNA sequencing. To the best of our knowledge, this is the first study to report the Burkholderia sp. antagonistic effect on S. rolfsii as a biological control agent for peanut stem rot. Their culture filtrates potently inhibited the hyphal growth, sclerotial formation, and germination of S. rolfsii. Also, the strain-produced volatile compounds inhibited the fungal growth. Pot experiments showed that F-1 and R-11 significantly reduced the peanut stem rot disease with the efficacy of 77.13 and 64.78%, respectively, which was significantly higher compared with carbendazim medicament (35.22%; P < 0.05). Meanwhile, F-1 and R-11 improved the activity of plant defense enzymes such as phenylalaninase (PAL), polyphenol oxidase (PPO), and peroxidase (POD) enhancing the systemic resistance of the peanut plants. This study demonstrated that Bacillus sp. F-1 and Burkholderia sp. R-11, with a strong antagonistic effect on S. rolfsii, can be potential biocontrol agents for peanut stem rot.

Comprehensive analysis of prognostic value, relationship to cell cycle, immune infiltration and m6A modification of ZSCAN20 in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a common tumor across the globe with a high mortality rate. ZSCAN20 is a ZNF transcription factor, a key determinant of gene expression. Nonetheless, the mechanism of ZSCAN20 as a potential clinical biomarker and therapeutic target for HCC is not understood. Here, TIMER, TCGA, ICGC databases and immunohistochemical (IHC) and Western Blot found ZSCAN20 mRNA and protein levels were upregulated. Additionally, Kaplan-Meier Plotter, GEPIA and TCGA databases showed high ZSCAN20 expression was related to the short survival time of HCC patients. Multivariate Cox analysis exposed that ZSCAN20 can act as an independent prognostic factor. We observed methylation level of ZSCAN20 was associated with the clinicopathological characteristics and prognosis of HCC patients through UALCAN. Furthermore, enrichment examination exposed functional association between ZSCAN20 and cell cycle, immune infiltration. Functional experiments showed that interference with ZSCAN20 significantly reduced the invasion, migration and proliferation abilities of HCC cells. An immune infiltration analysis showed that ZSCAN20 was associated with immune cells, particularly T cells. The expression of ZSCAN20 was correlated with poor prognosis in the Regulatory T-cell. And Real-Time RT-PCR analysis found interference with ZSCAN20 significantly reduced the expression of some chemokines. Finally, the TCGA and ICGC data analysis suggested that the ZSCAN20 expression was greatly related to m6A modifier related genes. In conclusion, ZSCAN20 can serve as a prognostic biomarker for HCC and provide clues about cell cycle, immune infiltration, and m6A modification.

ZNF320 is a hypomethylated prognostic biomarker involved in immune infiltration of hepatocellular carcinoma and associated with cell cycle.

Hepatocellular carcinoma (HCC) is one of the most deadly and common malignant cancers around the world, and the prognosis of HCC patients is not optimistic. ZNF320 belongs to Krüppel like zinc finger gene family. However, no studies have focused on the influence of ZNF320 in HCC. We first analyzed ZNF320 expression in HCC by using data from TCGA and ICGC, then conducted a joint analysis with TIMER and UALCAN, and validated by immunohistochemistry in clinical HCC samples. Then we applied UALCAN to explore the correlation between ZNF320 expression and clinicopathological characteristics. Consequently, using Kaplan-Meier Plotter analysis and the Cox regression, we can predict the prognostic value of ZNF320 for HCC patients. Next, the analysis by GO, KEGG, and GSEA revealed that ZNF320 was significantly correlated to cell cycle and immunity. Finally, TIMER and GEPIA analysis verified that ZNF320 expression is closely related to tumor infiltrating immune cells (TIIC), including B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells. The analysis of the TCGA and ICGC data sets revealed that ZNF320 expression was significantly correlated with m6A related genes (RBMX, YTHDF1, and METTL3). In conclusion, ZNF320 may be a prognostic biomarker related to immunity as a candidate for liver cancer.

MND1 functions as a potential prognostic biomarker associated with cell cycle and immune infiltration in kidney renal clear cell carcinoma.

Kidney renal clear cell carcinoma (KIRC) is a common and invasive subtype of renal tumors, which has poor prognosis and high mortality. MND1 is a meiosis specific protein that participates in the progress of diverse cancers. Nonetheless, its function in KIRC was unclear. Here, TIMER, TCGA, GEO databases and IHC found MND1 expression is upregulated in KIRC, leading to poor overall survival, and MND1 can serve as an independent prognostic factor. Moreover, enrichment analysis revealed the functional relationship between MND1 and cell cycle, immune infiltration. EdU and transwell assays confirmed that MND1 knockdown surely prohibited the proliferation, migration, and invasion of KIRC cells. Additionally, immune analysis showed that MND1 displayed a strong correlation with various immune cells. Interference with MND1 significantly reduces the expression of chemokines. TCGA and GEO databases indicated that MND1 expression is significantly related to two m6A modification related gene (METTL14, IGF2BP3). Finally, the drug sensitivity analysis revealed 7 potentially sensitive drugs for KIRC patients with high MND1 expression. In conclusion, MND1 can be used as a prognostic biomarker for KIRC and provides clues regarding cell cycle, immune infiltrates and m6A. Sensitive drugs may be an effective treatment strategy for KIRC patients with high expression of MND1.

The deubiquitinase OTUB1 fosters papillary thyroid carcinoma growth through EYA1 stabilization.

Deubiquitinating enzyme OTU domain-containing ubiquitin aldehyde-binding proteins 1 (OTUB1) has been shown to have an essential role in multiple carcinomas. However, the function of OTUB1 in papillary thyroid cancer (PTC) and the underlying mechanisms regulating PTC cells proliferation remain poorly understood. In this study, OTUB1 was significantly upregulated in papillary thyroid carcinoma tissues and cells. Through in vitro and in vivo experiments, knockdown of OTUB1 suppressed PTC cells growth whereas OTUB1 overexpression enhanced the proliferation ability of PTC cells. Moreover, the eyes absent homologue 1 (EYA1) was recognized as a potential target of OTUB1 through mass spectrometry analysis, and we further verified that EYA1 protein level was positively correlated with OTUB1 expression in PTC cells and clinical samples. Mechanistically, OTUB1 could interact with EYA1 directly and deubiquitinate EYA1 to stabilize it. At last, EYA1 was found to play an essential role in OTUB1-derived PTC cells growth. Overall, our investigation reveals that OTUB1 is a previously unrecognized oncogenic factor in PTC cells proliferation and suggests that OTUB1 might be a novel therapeutic target in PTC.

Deubiquitinase ZRANB1 drives hepatocellular carcinoma progression through SP1-LOXL2 axis.

Deubiquitinase (DUB) zinc finger RANBP2-type containing 1 (ZRANB1) has been reported to have a close relationship with cancers. However, its underlying role and molecular mechanisms in hepatocellular carcinoma (HCC) remain elusive. In this study, we demonstrated that ZRANB1 was highly expressed in HCC tissues. Additionally, ZRANB1 overexpression was correlated with poorer survival and ZRANB1 could be an independent predictor of poor prognosis for HCC patients. Through gain- and loss-of-function assays, we examined the oncogenic role of ZRANB1 in regulating HCC cell growth and metastasis in vitro and in vivo. To identify the downstream targets of ZRANB1 in regulating HCC tumorigenesis, we performed RNA-seq and demonstrated that Lysyl oxidase-like 2 (LOXL2) was the most significantly downregulated gene after ZRANB1 knockdown. Furthermore, the scatter plots indicated a significant positive correlation between ZRANB1 and LOXL2 expression in clinical HCC specimens. We also demonstrated that ZRANB1 knockdown downregulated the expression of LOXL2 and suppressed HCC growth and metastasis in vitro and in vivo. The effects of ZRANB1 knockdown were reversed by LOXL2 overexpression. More importantly, ZRANB1 regulated LOXL2 through specificity protein 1 (SP1) and SP1 overexpression rescued the suppression of HCC growth and metastasis induced by ZRANB1 knockdown. Mechanistically, ZRANB1 bound with SP1 directly and stabilized the SP1 protein by deubiquitinating it. The expression patterns of ZRANB1, SP1 and LOXL2 were evaluated in HCC patients. In summary, our research highlights a novel role of ZRANB1 in the tumorigenesis of HCC and suggests a new candidate prognostic biomarker for HCC treatment.

The deubiquitinase OTUD3 stabilizes ACTN4 to drive growth and metastasis of hepatocellular carcinoma.

OTU domain-containing protein 3 (OTUD3), a deubiquitinating enzyme, has been shown to participate in progression of multiple malignancies. The accurate function of OTUD3 in hepatocellular carcinoma (HCC) progression remains elusive. We found that OTUD3 was significantly overexpressed in HCC, and higher OTUD3 expression was correlated with larger tumor size, more distant metastasis, and worse TNM stage. A series of gain- and loss-of-function assays were also performed to examine the oncogenic function of OTUD3 in promoting HCC cell growth and metastasis in vitro. Using a xenograft mouse model, we showed that OTUD3 accelerated HCC progression in vivo. Furthermore, alpha-actinin 4 (ACTN4) was identified as a downstream target of OTUD3 through mass spectrometry analysis, and the ACTN4 protein level was significantly related to OTUD3 expression. Additionally, OTUD3 directly bound with ACTN4 and deubiquitinated ACTN4 to stabilize it. Finally, ACTN4 was found to be essential for OTUD3-mediated HCC proliferation and metastasis in vitro and in vivo. Collectively, our findings identify the oncogenic role of OTUD3 in HCC and suggest that OTUD3 can be considered as a pivotal prognostic biomarker and a potential therapeutic target.

The deubiquitinating enzyme ATXN3 promotes the progression of anaplastic thyroid carcinoma by stabilizing EIF5A2.

Ataxin-3 (ATXN3) is a ubiquitous deubiquitinating enzyme that plays an essential role in the carcinogenesis of numerous tumors and stabilizes the expression of substrates by deubiquitination. However, the functional role of ATXN3 in anaplastic thyroid carcinoma (ATC) remains unknown. In this research, we report that ATXN3 was overexpressed in ATC compared to that in paracancerous samples. Moreover, various gain/loss functional assays were performed to indicate that ATXN3 overexpression enhanced ATC cell proliferation and metastasis. We also found that ATXN3 and eukaryotic translation initiation factor 5A2 (EIF5A2) protein levels in ATC tissues are positively correlated, and ATXN3 promotes the proliferation and metastasis of ATC cells through EIF5A2. Mechanistically, ATXN3 promotes EIF5A2 expression by directly binding to EIF5A2 to reduce its ubiquitination and degradation. Therefore, for the first time, we clarified the role of ATXN3 in the carcinogenesis of ATC cells, which provides novel insights into potential therapeutic targets for ATC progression.

Integrated analysis of RNA-binding proteins in thyroid cancer.

Recently, the incidence of thyroid cancer (THCA) has been on the rise. RNA binding proteins (RBPs) and their abnormal expression are closely related to the emergence and pathogenesis of tumor diseases. In this study, we obtained gene expression data and corresponding clinical information from the TCGA database. A total of 162 aberrantly expressed RBPs were obtained, comprising 92 up-regulated and 70 down-regulated RBPs. Then, we performed a functional enrichment analysis and constructed a PPI network. Through univariate Cox regression analysis of key genes and found that NOLC1 (p = 0.036), RPS27L (p = 0.011), TDRD9 (p = 0.016), TDRD6 (p = 0.002), IFIT2 (p = 0.037), and IFIT3 (p = 0.02) were significantly related to the prognosis. Through the online website Kaplan-Meier plotter and multivariate Cox analysis, we identified 2 RBP-coding genes (RPS27L and IFIT3) to construct a predictive model in the entire TCGA dataset and then validate in two subsets. In-depth analysis revealed that the data gave by this model, the patient's high-risk score is very closely related to the overall survival rate difference (p = 0.038). Further, we investigated the correlation between the model and the clinic, and the results indicated that the high-risk was in the male group (p = 0.011) and the T3-4 group (p = 0.046) was associated with a poor prognosis. On the whole, the conclusions of our research this time can make it possible to find more insights into the research on the pathogenesis of THCA, this could be beneficial for individualized treatment and medical decision making.

CSN5 Promotes Carcinogenesis of Thyroid Carcinoma Cells Through ANGPTL2.

COP9 signalosome subunit 5 (CSN5) plays a key role in carcinogenesis of multiple cancers and contributes to the stabilization of target proteins through deubiquitylation. However, the underlying role of CSN5 in thyroid carcinoma has not been reported. In this research, our data showed that CSN5 was overexpressed in thyroid carcinoma tissues compared with paracancerous tissues. Furthermore, a series of gain/loss functional assays were performed to demonstrate the role of CSN5 in facilitating thyroid carcinoma cell proliferation and metastasis. Additionally, we found there was a positive correlation between CSN5 and angiopoietin-like protein 2 (ANGPTL2) protein levels in thyroid carcinoma tissues and that CSN5 promoted thyroid carcinoma cell proliferation and metastasis through ANGPTL2. We also identified the underlying mechanism that CSN5 elevated ANGPTL2 protein level by directly binding it, decreasing its ubiquitination and degradation. Overall, our results highlight the significance of CSN5 in promoting thyroid carcinoma carcinogenesis and implicate CSN5 as a promising candidate for thyroid carcinoma treatment.

The 14-3-3η/GSK-3ß/ß-catenin complex regulates EndMT induced by 27-hydroxycholesterol in HUVECs and promotes the migration of breast cancer cells.

Endothelial-mesenchymal transition (EndMT) is the transformation of endothelial cell morphology to mesenchymal cell morphology, accompanied by decline of endothelial function and enhancement of mesenchymal function, which promotes tumor progression and tumor cell invasion and metastasis. 27-Hydroxycholesterol (27-HC) is a cholesterol metabolite, which has a high content in human blood. 27-HC promotes breast cancer cell proliferation, invasion, and migration. We previously showed that 27-HC promotes EndMT; however, the underlying mechanism still needs to be further explored. We studied the role of the 14-3-3η/GSK-3ß/ß-catenin complex in EndMT. Our results show that 27-HC induces oxidative stress in HUVECs and activates the p38 signaling pathway, thereby inhibiting the binding of 14-3-3η/GSK-3ß/ß-catenin, promoting the increase of free ß-catenin and nuclear translocation, and finally inducing EndMT. Treatment with N-acetylcysteine (NAC) blocked 27-HC-induced ROS generation and p38 signaling pathway activation, prevented ß-catenin from release from binding, and inhibited EndMT. Blocking ROS production or p38 signaling or knocking down 14-3-3η inhibited 27-HC-induced EndMT and inhibited breast cancer cell metastasis. These findings indicate 14-3-3η is necessary for interactions between the p38 kinase and the GSK-3ß/ß-catenin complex and serves as an adaptor to transmit the upstream kinase signal to the downstream signal, thereby promoting EndMT and breast cancer cell migration.

Clinical Characteristics and Prognostic Analysis of Patients With Signet Ring Cell Gastric Carcinoma.

We do not know the clinical and prognostic factors that influence the survival of patients with gastric signet ring cell carcinoma (SRC). Therefore, a retrospective review was undertaken of 219 patients with SRC who had undergone gastrectomy between January 2009 and December 2012 in our hospital. Patient age, sex, TNM stage, vessel carcinoma embolus, perineural invasion, tumor site and operation type, postoperative chemotherapy, and five-year overall survival were recorded and evaluated. In our study, 93 cases (42.5%) were signet ring cell carcinoma only, and 126 cases (57.5%) were signet ring cell carcinoma coexisting with other components (such as adenocarcinoma or mucus adenocarcinoma). Eighty-three patients were female, 136 were male, 46 occurred at the gastroesophageal junction (21.0%), 63 at the fundus/body (28.8%), 80 were antrum/pylorus (36.5%), and 30 were whole stomach (13.7%). The prognosis of gastric antrum/ pylorus cancer was the best (P < 0.05). There were 133 patients (60.7%) with stage III, and the single factor analysis showed that the earlier the stage, the better the prognosis. The overall five-year survival rate was 30.1% in all patients. One-hundred and 41 patients (64.4%) received D2 radical surgery, 64 (29.2%) received D1 radical operation, and 14 (6.4%) received palliative resection, and the patients who received D2 had the best overall survival (P < 0.05). The survival time of the paclitaxel-based regimen in postoperative adjuvant chemotherapy tended to be prolonged. There was no statistical difference in overall survival between the percentage of signet-ring cells and sex. In summary, age, tumor stage, and surgical resection combined with D2 lymphadenectomy were independent prognostic factors for SRC. Adjuvant chemotherapy with a paclitaxel-based regimen may improve the survival of patients with SRC.

[Clinical and Pathological Characteristics of Blastic Plasmacytoid Dendritic Cell Neoplasm].

OBJECTIVE: To explore the clinical manifestation, pathological features and treatment regimen of blastic plasmacytoid dendritic cell neoplasm (BPDCN). METHODS: The clinical and pathologic features, diagnosis, treatment and prognosis of 5 BPDCN patients were analyzed retrospectively. RESULTS: 5 patients had skin lesions, and bone marrow involvement. The immunohistochemical staining showed that the CD56 expression was observed in 5 patients, CD4 and CD123 in 4 patients, and CD43 expressed in 3 patients. After initial treatment, 3 patients achieved complete remission and 1 patient did not. One patient showed disease progression after partial remission for 1 month. Two young patients underwent sibling allo-PBHSCT, and then achieved long-term survival. CONCLUSION: BPDCN often presents skin lesions as the first symptom, moreover, soft tissues, lymph nodes and bone marrow were involved, which suggested the disease progresses. There is currently no uniform treatment protocol for this disease. Active allogeneic peripheral blood hematopoietic stem cell transplantation in the CR1 phase for appropriate patients may increase their chances for long-term survival.

27-Hydroxycholesterol-induced EndMT acts via STAT3 signaling to promote breast cancer cell migration by altering the tumor microenvironment.

Objective: The endothelial to mesenchymal transition (EndMT) plays a major role in cancer metastasis by regulating the complexity of the tumor microenvironment (TME). Here, we investigated whether 27-hydroxycholesterol (27HC) induces EndMT in endothelial cells (ECs). Methods: EndMT markers in the human microvascular endothelial cell-1 (HMEC-1) cell line and human umbilical vein endothelial cells (HUVECs) stimulated with 27HC were evaluated with Western blot. Epithelial to mesenchymal transition (EMT) markers in breast cancer (BC) cells cultured in conditioned medium were investigated with quantitative real time polymerase chain reaction (qRT-PCR). The MMP-2 and MMP-9 mRNA expression and activity were detected with qRT-PCR and gelatin zymography assays, respectively. The effect of activated STAT3 on 27HC-induced EndMT was validated by Western blot, immunofluorescence staining, and cell transfection assays. The migration ability of BC cells was evaluated with Transwell assays. Results: We found that 27HC induced EndMT in HMEC-1 and HUVECs, and 27HC-induced EndMT facilitated EMT and BC cell migration. The 27HC-induced EMT of BC cells also promoted EndMT and HUVEC migration. Investigation of the underlying molecular mechanisms revealed that STAT3 knockdown repressed EndMT in HUVECs as well as migration in BC cells induced with 27HC. In addition, C646 and resveratrol, inhibitors of STAT3 acetylation, repressed the expression of Ac-STAT3, p-STAT3, and EndMT markers in HUVECs exposed to 27HC; these HUVECs in turn attenuated the migration ability of BC cells in 27HC-induced EndMT. Conclusions: Cross-talk between 27HC-induced EndMT and EMT was observed in the TME. Moreover, activation of STAT3 signaling was found to be involved in 27HC-induced EndMT.

Resveratrol inhibits the proliferation of estrogen receptor-positive breast cancer cells by suppressing EZH2 through the modulation of ERK1/2 signaling.

Enhancer of zeste homolog 2 (EZH2) is frequently overexpressed in breast cancer and plays an important role in maintaining the cell proliferative capacity. However, the mechanisms underlying the transcriptional regulation of EZH2 in estrogen receptor (ER)-positive breast cancer cells remain unclear. The antitumor effects of resveratrol have been reported. However, whether EZH2 was involved in these effects needs further exploration. Here, we showed that EZH2 is required for estrogen-induced cell proliferation in ER-positive breast cancer. Exposure to 17ß-estradiol (E2) upregulated EZH2 via ERα signaling, and this effect was blocked by U0126, a MEK inhibiter. Resveratrol inhibited the proliferation and colony formation in ER-positive breast cancer cells and downregulated EZH2 through inhibition of phospho-ERK1/2. These findings indicated that ERK1/2 and ER signaling-mediated EZH2 upregulation is crucial for the proliferation of ER-positive breast cancer cells. The suppression of EZH2 expression by ERK1/2 dephosphorylation is important for the antiproliferative activities of resveratrol against ER-positive breast cancer cells.