Recent advances in the exploration of oxazolidinone scaffolds from compound development to antibacterial agents and other bioactivities.

Bacterial infections cause a variety of life-threatening diseases, and the continuous evolution of drug-resistant bacteria poses an increasing threat to current antimicrobial regimens. Gram-positive bacteria (GPB) have a wide range of genetic capabilities that allow them to adapt to and develop resistance to practically all existing antibiotics. Oxazolidinones, a class of potent bacterial protein synthesis inhibitors with a unique mechanism of action involving inhibition of bacterial ribosomal translation, has emerged as the antibiotics of choice for the treatment of drug-resistant GPB infections. In this review, we discussed the oxazolidinone antibiotics that are currently on the market and in clinical development, as well as an updated synopsis of current advances on their analogues, with an emphasis on innovative strategies for structural optimization of linezolid, structure-activity relationship (SAR), and safety properties. We also discussed recent efforts aimed at extending the activity of oxazolidinones to gram-negative bacteria (GNB), antitumor, and coagulation factor Xa. Oxazolidinone antibiotics can accumulate in GNB by a conjugation to siderophore-mediated ß-lactamase-triggered release, making them effective against GNB.

Design, synthesis and antibacterial evaluation of low toxicity amphiphilic-cephalosporin derivatives.

Global public health is facing a serious problem as a result of the rise in antibiotic resistance and the decline in the discovery of new antibiotics. In this study, two series of amphiphilic-cephalosporins were designed and synthesized, several of which showed good antibacterial activity against both Gram-positive and Gram-negative bacteria. Structure-activity relationships indicated that the length of the hydrophobic alkyl chain significantly affects the antibacterial activity against Gram-negative bacteria. The best compound 2d showed high activity against drug-susceptible Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) with MICs of 0.5 and 2-4 µg/mL, respectively. Furthermore, 2d remained active in complex mammalian body fluids and had a longer post-antibiotic effect (PAE) than vancomycin. Mechanism studies indicated that compound 2d lacks membrane-damaging properties and can target penicillin-binding proteins to disrupt bacterial cell wall structure, inhibit the metabolic activity and induce the accumulation of reactive oxygen species (ROS) in bacteria. Compound 2d showed minimal drug resistance and was nontoxic to HUVEC and HBZY-1 cells with CC50 > 128 µg/mL. These findings suggest that 2d is a promising drug candidate for treating bacterial infections.

Effective ciprofloxacin cationic antibacterial agent against persister bacteria with low hemolytic toxicity.

With the widespread use of antibiotics, bacterial resistance has developed rapidly. To make matters worse, infections caused by persistent bacteria and biofilms often cannot be completely eliminated, which brings great difficulties to clinical medication. In this work, three series of quinolone pyridinium quaternary ammonium small molecules were designed and synthesized. Most of the compounds showed good antibacterial activity against Gram-positive bacteria (S. aureus and E. faecalis) and Gram-negative bacteria (E. coli and S. maltophilia). The activity of the para-pyridine quaternary ammonium salt was better than that of the meta-pyridine. 3f was the optimal compound with good stability in body fluids and was unlikely to induce bacterial resistance. The hemolysis rate of erythrocytes at 1280 µg/mL for 3f was only 5.1%. Encouragingly, 3f rapidly killed bacteria within 4 h at 4 × MIC concentration and was effective in killing persistent bacteria in biofilms. The antibacterial mechanism experiments showed that 3f could cause disorder of bacterial membrane potential, increase bacterial membrane permeability, dissolve and destroy the membrane. Incomplete bacterial membranes lead to leakage of bacterial genetic material, concomitant production of ROS, and bacterial death due to these multiple effects.

Downregulation of miR­7 and miR­153 is involved in Helicobacter pylori CagA induced gastric carcinogenesis and progression.

Helicobacter pylori (H. pylori) infection plays a pivotal role in the development of gastric cancer (GC). However, the association between aberrant microRNAs (miRNAs/miRs) expression and H. pylori­induced GC remains poorly understood. The present study reported that repeated infection of H. pylori caused the oncogenicity of GES­1 cells in BALB/c Nude mice. miRNA sequencing revealed that both miR­7 and miR­153 were significantly decreased in the cytotoxin­associated gene A (CagA) positive GC tissues and this was further confirmed in a chronic infection model of GES­1/HP cells. Further biological function experiments and in vivo experiments validated that miR­7 and miR­153 can promote apoptosis and autophagy, inhibit proliferation and inflammatory response in GES­1/HP cells. All the associations between miR­7/miR­153 and their potential targets were revealed via bioinformatics prediction and dual­luciferase reporter assay. Particularly, downregulation of both miR­7 and miR­153 obtained an improved sensitivity and specificity in diagnosing H. pylori (CagA+)­induced GC. The present study identified that the combination of miR­7 and miR­153 may be regarded as novel therapeutic targets in H. pylori CagA (+)­associated GC.

Identification and validation of a novel ubiquitination-related gene UBE2T in Ewing's sarcoma.

Background: Ewing's sarcoma (ES) is one of the most prevalent malignant bone tumors worldwide. However, the molecular mechanisms of the genes and signaling pathways of ES are still not well sufficiently comprehended. To identify candidate genes involved in the development and progression of ES, the study screened for key genes and biological pathways related to ES using bioinformatics methods. Methods: The GSE45544 and GSE17618 microarray datasets were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified, and functional enrichment analysis was performed. A protein-protein interaction (PPI) network was built, and key module analysis was performed using STRING and Cytoscape. A core-gene was gained and was validated by the validation dataset GSE67886 and immunohistochemistry (IHC). The diagnostic value and prognosis evaluation of ES were executed using, respectively, the ROC approach and Cox Regression. Results: A total of 187 DEGs, consisting of 56 downregulated genes and 131 upregulated genes, were identified by comparing the tumor samples to normal samples. The enriched functions and pathways of the DEGs, including cell division, mitotic nuclear division, cell proliferation, cell cycle, oocyte meiosis, and progesterone-mediated oocyte maturation, were analyzed. There were 149 nodes and 1246 edges in the PPI network, and 15 hub genes were identified according to the degree levels. The core gene (UBE2T) showed high expression in ES, validated by using GSE67886 and IHC. The ROC analysis revealed UBE2T had outstanding diagnostic value in ES (AUC = 0.75 in the training set, AUC = 0.90 in the validation set). Kaplan-Meier (analysis of survival rate) and Cox Regression analyses indicated that UBE2T was a sign of adverse results for sufferers with ES. Conlusion: UBE2T was a significant value biomarker for diagnosis and treatment of ES, thereby presenting a novel potential therapeutic target for ES as well as a new perspective for assessing the effect of treatment and prognostic prediction.

Huntingtin-associated protein 1 is a potential tumor suppressor for gastric cancer.

BACKGROUND: Gastric cancer is heterogeneous cancer and the causes of this disease are complex. New diagnostic and therapeutic targets are urgently needed to explore. Huntingtin-associated protein 1 (HAP1) is directly related to Huntington's disease (HD). However, patients with Huntington's disease have a lower incidence of cancer. Therefore, we are committed to studying the correlation between HAP1 and gastric carcinogenesis and development. METHODS AND RESULTS: Immunohistochemical staining, western blot analysis, and RT-qPCR were conducted to explore the localization and expression of HAP1 in gastric cancer. To study the biological significance of HAP1, we overexpressed HAP1 in both MKN28 and AGS cell lines by lentivirus infection. To explore the role of HAP1 in cell proliferation, the cells counting assay, EdU incorporation assay, and colony formation assay were carried out. We performed the wound healing assay and transwell assay to study the cell migration and invasion. To further investigate whether HAP1 could regulate gastric cancer cell death during glucose deprivation, Annexin V-FITC/PI staining was performed. In our study, we elucidated that HAP1 was downregulated in gastric cancer. What's more, overexpressing HAP1 inhibited cell proliferation, cell migration and invasion, and triggered apoptosis during glucose deprivation. More importantly, the antitumor properties and mechanisms of HAP1 have been elucidated further in gastric cancer. CONCLUSIONS: Taken together, the available evidence implies that HAP1 may serve as a potential tumor suppressor, making it a significant target in preventing and treating gastric cancer. This research provides a theoretical basis for the early diagnosis, clinical targeted therapy, and prognosis evaluation of gastric cancer.

The value of Angipoietin-2 as a biomarker for the prognosis of osteosarcoma: A protocol for systematic review and meta-analysis.

BACKGROUND: The function of Angipoietin-2 (Agn2) in osteosarcoma has not been fully explored and exists controversial. Therefore, we conducted a meta-analysis to investigate the role of Agn2 in the prognosis of osteosarcoma. In addition, bioinformatics analysis was carried out to reveal the mechanism and related pathways of Agn2 in osteosarcoma. METHODS: Literature search was operated on databases up to July 2021, including PubMed, Web of Science, China National Knowledge Infrastructure, China Biology Medicine disc, and Wan Fang Data. The relation between Agn2 expression and survival outcome was estimated by hazard ratio and 95% confidence interval. Meta-analysis was performed on the Stata 16.0. Being obtained from The Cancer Genome Atlas, the original data were used to further verify the prognostic role of Agn2 in osteosarcoma. Gene set enrichment analysis was applied to predict the potential mechanism of Agn2. The correlation between Agn2 and osteosarcoma immune infiltration was analyzed by TIMER database. RESULTS: The results of this meta-analysis would be submitted to peer-reviewed journals for publication. CONCLUSION: This study will provide evidence for the exploration of the relationship between Agn2 and the prognosis of osteosarcoma and its mechanism. ETHICS AND DISSEMINATION: The private information from individuals will not be published. This systematic review also should not damage participants' rights. Ethical approval is not available. The results will be published in a peer-reviewed journal or disseminated in relevant conferences. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/GWQ53.

Insight into the influence of donor-acceptor system on graphitic carbon nitride nanosheets for transport of photoinduced charge carriers and photocatalytic H2 generation.

The rapid recombination of photogenerated charges is one of the main restriction for promoting the photocatalytic H2 generation of graphitic carbon nitride (CN) material. Herein, donor-acceptor (D-A) system was introduced into CN nanosheets by oxygen and/or phenyl doping (DA-CN) strategy to facilitate the transport of photoinduced charge carriers and H2 generation. Experimental and theoretical results revealed that the nanosheet structure of DA-CN shortened the photoexcited charges transport length to the surface, and the D-A system embedded in DA-CN provided the dipole-induced internal electric field for charges transport. As a consequence, compared with pristine CN, DA-CN samples performed the improved transport of photogenerated charges and photocatalytic H2 evolution. Notably, DA-CN-OP (oxygen and phenyl co-doping) with the strongest dipole-induced internal electric field originated from D-A system displayed the highest photocatalytic H2 evolution rate at 7.394 mmol g-1h-1, which was 7.67 times as that of pristine CN (0.964 mmol g-1h-1). This work not only provides a simple strategy to construct highly efficient CN nanosheet photocatalyst with D-A system, but also promote the deep insight into the effect of molecular dipole originated from D-A system on the transport of photoinduced charge carriers and photocatalytic activity for CN material.

PDGF-BB promotes angiogenesis of human osteosarcoma through exosomes / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To explore whether PDGF-BB can be transmitted through exosome and verify its angiogenic function in human osteosarcoma. Methods: Exosomes from a variety of human osteosarcoma cells were isolated. The expression of PDGF-BB in cells and exosomes was detected by WB. Exosomes derived from osteosarcoma SJSA-1 cells were co-incubated with HUVEC, and the pattern of exosomal PDGF-BB entering HUVEC was observed using Immunofluorescence and confocal scanning microscope. SJSA-1 cell lines with PDGF-BB over-expression or knockdown were constructed by lentiviral infection, and the exosomes derived from transfected SJSA-1 cells were isolated and incubated with HUVEC. Microtubule formation experiment was conducted to detect their effects on angiogenesis; SJSA-1 cell transplanted xenograft model was established in nude mice, and the exosomes derived from SJSA-1 cells with PDGF-BB over-expression or knockdown were infused into nude mice to observe their effects on tumor growth. Results: The exosomes derived from osteosarcoma cells were successfully isolated, in which a large amount of PDGF-BB was confirmed. The exosomes entered HUVEC by endocytosis. The SJSA-1 cell lines with PDGF-BB over-expression or knockdown were successfully constructed, and the corresponding exosomes were isolated. Compared with the control group, exosomes with high PDGF-BB content significantly promoted HUVEC angiogenesis (P < 0.01 , t=13.51) and tumor growth (P < 0.01 ), while exosomes with low PDGF-BB content reduced the angiogenesis ability of HUVEC (P < 0.01 , t=8.226) and inhibited tumor growth (P < 0.01 ). Conclusion: The exosomal PDGF-BB secreted by osteosarcoma cells can be directly absorbed by HUVEC and induce tumor angiogenesis, further promoting the growth of osteosarcoma.

Bone marrow mesenchymal stem cells induce M2 microglia polarization through PDGF-AA/MANF signaling.

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) are capable of shifting the microglia/macrophages phenotype from M1 to M2, contributing to BMSCs-induced brain repair. However, the regulatory mechanism of BMSCs on microglia/macrophages after ischemic stroke is unclear. Recent evidence suggests that mesencephalic astrocyte-derived neurotrophic factor (MANF) and platelet-derived growth factor-AA (PDGF-AA)/MANF signaling regulate M1/M2 macrophage polarization. AIM: To investigate whether and how MANF or PDGF-AA/MANF signaling influences BMSCs-mediated M2 polarization. METHODS: We identified the secretion of MANF by BMSCs and developed transgenic BMSCs using a targeting small interfering RNA for knockdown of MANF expression. Using a rat middle cerebral artery occlusion (MCAO) model transplanted by BMSCs and BMSCs-microglia Transwell coculture system, the effect of BMSCs-induced downregulation of MANF expression on the phenotype of microglia/macrophages was tested by Western blot, quantitative reverse transcription-polymerase chain reaction, and immunofluorescence. Additionally, microglia were transfected with mimics of miR-30a*, which influenced expression of X-box binding protein (XBP) 1, a key transcription factor that synergized with activating transcription factor 6 (ATF6) to govern MANF expression. We examined the levels of miR-30a*, ATF6, XBP1, and MANF after PDGF-AA treatment in the activated microglia. RESULTS: Inhibition of MANF attenuated BMSCs-induced functional recovery and decreased M2 marker production, but increased M1 marker expression in vivo or in vitro. Furthermore, PDGF-AA treatment decreased miR-30a* expression, had no influence on the levels of ATF6, but enhanced expression of both XBP1 and MANF. CONCLUSION: BMSCs-mediated MANF paracrine signaling, in particular the PDGF-AA/miR-30a*/XBP1/MANF pathway, synergistically mediates BMSCs-induced M2 polarization.

Phenyl-Bridged Graphitic Carbon Nitride with a Porous and Hollow Sphere Structure to Enhance Dissociation of Photogenerated Charge Carriers and Visible-Light-Driven H2 Generation.

Graphitic carbon nitride (CN) suffers from rapid recombination of photoexcited charges due to the existing highly symmetrical tri-s-triazine ring and long charge diffusion path, resulting in moderate photocatalytic activity. The bridged phenyl embedded in the CN structure was used to reduce the symmetry of the tri-s-triazine ring. In addition, the CN material was constructed with a porous and hollow sphere structure to shorten the diffusion path of charge carriers. Herein, simple thermal polymerization of a trimesic acid-doped melamine-cyanuric acid (MCA) supramolecular was employed to construct phenyl-bridged graphitic carbon nitride (Ph-CN-MCA) with a hollow sphere structure composed of porous nanosheets for visible-light catalytic H2 evolution. The porous and hollow sphere-structured Ph-CN-MCA possessed increased degree of polymerization, more negative conduction band potential, enlarged Brunauer-Emmett-Teller (BET) surface area, and shortened charge diffusion path. In addition, bridged phenyl embedded in the Ph-CN-MCA structure not only accelerated the dissociation of photogenerated carriers but also narrowed the band gap and extended the visible-light absorption. Further, the separated highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of Ph-CN-MCA facilitated the spatial dissociation of photogenerated charges, which was also confirmed by theoretical calculations. As a consequence, compared with the reference CN-MA catalyst prepared from melamine, Ph-CN-MCA showed approximately 48.42 times the photocatalytic H2 evolution under visible-light irradiation. The developed synthetic method herein highlights that phenyl-bridged graphitic carbon nitride with a porous and hollow sphere structure could provide an efficient platform to boost the dissociation of photoexcited charge carriers and photocatalytic H2 evolution.

Hypoxia regulates angeogenic-osteogenic coupling process via up-regulating IL-6 and IL-8 in human osteoblastic cells through hypoxia-inducible factor-1α pathway.

Inappropriate angiogenesis and osteogenesis are considered as the crucial factors of osteoporotic fracture. Hypoxia is a primary driving force for regulating the angiogenic-osteogenic coupling process. Our recent results indicated that hypoxia could improve angiogenesis as well as differentiation and activity of osteoblastic cells via up-regulating VEGF through HIF-1α pathway. Here we demonstrated that in human osteoblastic MG-63, U2-OS and Saos-2 cells, besides VEGF, the other two pro-angiogenic factors IL-6 and IL-8 were also up-regulated by hypoxia and CoCl2 (a mimic of hypoxia). Mechanism studies indicated overexpression of HIF-1α (generated from transfection with a plasmid encoding sense HIF-1α) markedly increased the levels of IL-6 and IL-8 in osteoblastic cells. Furthermore, a luciferase reporter assay was performed using the reporter vector containing the IL-6 or IL-8 promoter sequence to illustrate observably increased activity of hypoxia-induced IL-6 and IL-8 promoter caused by overexpression of HIF-1α. Additionally, chromatin immune-precipitation analysis showed hypoxia increased the DNA binding ability of HIF-1α to IL-6 or IL-8 promoter. Analysis in vitro by MTT test and Boyden chamber assay showed exogenous IL-6 and IL-8 (a relatively short period of treatment with recombinant IL-6 or IL-8 equivalent to the autocrine levels) could significantly promote the proliferation of human osteoblastic, endothelial and monocytic cells, as well as the migration of human endothelial cells. Taken together, these results indicate that IL-6 and IL-8 in osteoblastic cells may also contribute to the angiogenic-osteogenic coupling process via HIF-1α pathway. Besides VEGF, IL-6- or IL-8-targeted adjunctive therapy maybe a new strategy to improve the treatment of osteoporosis.

Phase-dependent Fano-shape optomechanically induced transparency.

We present a detailed study of a three-mode-coupling cavity optomechanical system where one mechanical mode and two optical whispering-gallery modes are coupled together. We extend the earlier investigation of regular optomechanically induced transparency (OMIT) [Science330, 1520 (2010)SCIEAS0036-807510.1126/science.1195596] in a more general case. A complete analytical description of the present system is obtained, and quantitative analyses of the Fano-shape OMIT spectrum are provided. It is clearly shown that a sharp and asymmetric Fano-shape OMIT lineshape, which is decided by the phase difference between the probe field and the mechanical driving, can be observed from the probe output.

Salidroside accelerates fracture healing through cell-autonomous and non-autonomous effects on osteoblasts.

Salidroside (SAL), a major active component of Rhodiola rosea L., exhibits diverse pharmacological effects. However, the direct roles of SAL in fracture healing remain largely unknown. Here, we demonstrate that SAL significantly promotes proliferation by altering the cell-cycle distribution of osteoblastic cells. SAL also greatly stimulates osteoblast differentiation and mineralization by inducing the expression of Runx2 and Osterix. In addition to its osteoblast-autonomous effects, SAL can activate the HIF-1α pathway coupling of angiogenesis and osteogenesis through cell-non-autonomous effects. Our in vitro results suggest that SAL significantly up-regulates HIF-1α expression at the mRNA and protein levels. Furthermore, the nuclear translocation and transcriptional activity of HIF-1α and the HIF-responsive gene VEGF increase following SAL treatment. Our mechanistic study revealed that the regulation of osteoblastic proliferation and HIF-1α expression partly involves MAPK/ERK and PI3K/Akt signaling. Our in vivo analysis also demonstrated that SAL can promote angiogenesis within the callus and accelerate fracture healing. Thus, SAL promotes skeletal regeneration in cell-autonomous and cell-non-autonomous ways and might be a potential therapy for accelerating fracture healing.

Protective effect of salidroside against bone loss via hypoxia-inducible factor-1α pathway-induced angiogenesis.

Hypoxia-inducible factor (HIF)-1α plays a critical role in coupling angiogenesis with osteogenesis during bone development and regeneration. Salidroside (SAL) has shown anti-hypoxic effects in vitro and in vivo. However, the possible roles of SAL in the prevention of hypoxia-induced osteoporosis have remained unknown. Two osteoblast cell lines, MG-63 and ROB, were employed to evaluate the effects of SAL on cell viability, apoptosis, differentiation and mineralization in vitro. Rats subjected to ovariectomy-induced bone loss were treated with SAL in vivo. Our results showed that pre-treatment with SAL markedly attenuated the hypoxia-induced reductions in cell viability, apoptosis, differentiation and mineralization. SAL down-regulated HIF-1α expression and inhibited its translocation; however, SAL increased its transcriptional activity and, consequently, up-regulated vascular endothelial growth factor (VEGF). In vivo studies further demonstrated that SAL caused decreases in the mineral, alkaline phosphatase (ALP), and BGP concentrations in the blood of ovariectomized (OVX) rats. Moreover, SAL improved the trabecular bone microarchitecture and increased bone mineral density in the distal femur. Additionally, SAL administration partially ameliorated this hypoxia via the HIF-1α-VEGF signalling pathway. Our results indicate that SAL prevents bone loss by enhancing angiogenesis and osteogenesis and that these effects are associated with the activation of HIF-1α signalling.

Biological function of hpsh4590 localized in the plasticity zone of Helicobacter pylori.

The aim of this study was to determine the biological function of hpsh4590 in Helicobacter pylori. After Hpsh4590 was expressed using a prokaryotic expression system, the cytotoxic effects and IL-8 production of Hpsh4590 were analyzed by co-culturing with GES-1 cells. Meanwhile, the antibody of rHpsh4590, produced by immunizing rabbit, was used for localization and protein interaction studies. Hpsh4590 fusion protein was expressed successfully in Escherichia coli Rosetta (DE3), and the polyclonal antibody was produced at high titers. The MTT assay showed that the inhibition ratio of GES-1 cells cultured with 0.1 µg/mL rHpsh4590 (3.02% ± 0.02%) was significantly lower than that of 20 µg/mL rHpsh4590 (57.57% ± 0.03%, p < 0.01), while DAPI staining showed the cytotoxic effects of rHpsh4590 for GES-1 cells. The up-regulation of cleaved caspase-3 and cleaved PARP was observed after GES-1 cells co-cultured with rHpsh4590 by Western blot. Co-culturing of GES-1 cells with rHpsh0459 (20 µg/mL) led to significant production of IL-8 at 12 h(1097.74 ± 212.37 pg/mL) and 24 h (1379.55 ± 209.58 pg/mL) then at 6 h(134.68 ± 14.64 pg/mL, p < 0.01). These observations suggest that the cytotoxicity of Hpsh4590 occurred in a concentration dependent manner, which is related with IL-8 secretion from gastric mucosal epithelial cells. Hpsh4590 was found localized in the membrane and the periplasm of H. pylori, interacted with zinc finger protein and methionine ABC transporter ATP-binding protein, and potentially regulates DNA uptake or transfer.

Endometrial Mesenchymal Stem Cells Isolated from Menstrual Blood by Adherence.

Objective. To find a convenient and efficient way to isolate MSCs from human menstrual blood and to investigate their biological characteristics, proliferative capacity, and secretion levels. Methods. MSCs were isolated from menstrual blood of 3 healthy women using adherence. Cell immunological phenotype was examined by flow cytometry; the adipogenic, osteogenic, and chondrogenic differentiation of MSCs was examined by Oil-Red-O staining, ALP staining, and Alcian Blue staining, respectively; and the secretion of cytokines, including vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and insulin-like growth factor-1 (IGF-1), was detected using enzyme-linked immunosorbent assay. Results. MB-MSCs were successfully isolated from human menstrual blood using adherence. They were positive for CD73, CD105, CD29, and CD44, but negative for CD31 and CD45. The differentiated MB-MSCs were positive for ALP staining, Oil-Red-O staining, and Alcian Blue staining. In addition, they could secrete antiapoptotic cytokines, such as VEGF, IGF-1, and HGF. Conclusion. It is feasible to isolate MSCs from human menstrual blood, thus avoiding invasive procedures and ethical controversies. Adherence could be a promising alternative to the density gradient centrifugation for the isolation of MSCs from menstrual blood.

IL6 induces TAM resistance via kinase-specific phosphorylation of ERα in OVCA cells.

About 40-60% of ovarian cancer (OVCA) cases express ERα, but only a small proportion of patients respond clinically to anti-estrogen treatment with estrogen receptor (ER) antagonist tamoxifen (TAM). The mechanism of TAM resistance in the course of OVCA progression remains unclear. However, IL6 plays a critical role in the development and progression of OVCA. Our recent results indicated that IL6 secreted by OVCA cells may promote the resistance of these cells to TAM via ER isoforms and steroid hormone receptor coactivator-1. Here we demonstrate that both exogenous (a relatively short period of treatment with recombinant IL6) and endogenous IL6 (generated as a result of transfection with a plasmid encoding sense IL6) increases expression of pERα-Ser118 and pERα-Ser167 in non-IL6-expressing A2780 cells, while deleting endogenous IL6 expression in IL6-overexpressing CAOV-3 cells (by transfection with a plasmid encoding antisense IL6) reduces expression of pERα-Ser118 and pERα-Ser167, indicating that IL6-induced TAM resistance may also be associated with increased expression of pERα-Ser118 and pERα-Ser167 in OVCA cells. Results of further investigation indicate that IL6 phosphorylates ERα at Ser118 and Ser167 by triggering activation of MEK/ERK and phosphotidylinositol 3 kinase/Akt signaling, respectively, to activate the ER pathway and thereby induce OVCA cells resistance to TAM. These results indicate that IL6 secreted by OVCA cells may also contribute to the refractoriness of these cells to TAM via the crosstalk between ER and IL6-mediated intracellular signal transduction cascades. Overexpression of IL6 not only plays an important role in OVCA progression but also promotes TAM resistance. Our results indicate that TAM-IL6-targeted adjunctive therapy may lead to a more effective intervention than TAM alone.

Autocrine production of interleukin-6 confers ovarian cancer cells resistance to tamoxifen via ER isoforms and SRC-1.

Although 40-60% of ovarian cancer (OVCA)s express estrogen receptor (ER)α, only a minor proportion of patients respond to anti-estrogen treatment with ER antagonist tamoxifen (TAM). The mechanism underlying TAM resistance in the course of OVCA progression is incompletely understood. However, interleukin-6 (IL-6) plays a critical role in the development and progression of OVCA. Here we explore an association between IL-6 and TAM resistance. We demonstrate that both exogenous (a relatively short period of treatment with recombinant IL-6) and endogenous IL-6 (by transfecting with plasmid encoding for sense IL-6) induce TAM resistance in non-IL-6-expressing A2780 cells, while deleting of endogenous IL-6 expression in IL-6-overexpressing CAOV-3 cells (by transfecting with plasmid encoding for antisense IL-6) promotes the sensitivity of these cells to TAM. Further investigation indicates that TAM resistance caused by IL-6 is associated with the alteration of ERα, ERß and steroid hormone receptor coactivator (SRC)-1 expression levels, the protein interactions between SRC-1 and ERα, but not ERß, as well as blockage of estrogen-induced ER receptor nuclear translocation. These results show that IL-6 secreted by OVCA cells may contribute to the refractoriness of these cells to TAM via ER isoforms and SRC-1. Overexpression of IL-6 not only plays an important role in OVCA progression but also contributes to TAM resistance. Our studies suggest that TAM-IL-6-targeted adjunctive therapy may lead to a more effective intervention than TAM alone.