Cancer stem cell-derived CHI3L1 activates the MAF/CTLA4 signaling pathway to promote immune escape in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) development may be associated with tumor immune escape. This study explores whether the CHI3L1/MAF/CTLA4/S100A4 axis affects immune escape in TNBC through interplay with triple-negative breast cancer stem cells (TN-BCSCs).

OBJECTIVE

The aim of this study is to utilize single-cell transcriptome sequencing (scRNA-seq) to uncover the molecular mechanisms by which the CHI3L1/MAF/CTLA4 signaling pathway may mediate immune evasion in triple-negative breast cancer through the interaction between tumor stem cells (CSCs) and immune cells.

METHODS

Cell subsets in TNBC tissues were obtained through scRNA-seq, followed by screening differentially expressed genes in TN-BCSCs and B.C.s (CD44+ and CD24-) and predicting the transcription factor regulated by CHI3L1. Effect of CHI3L1 on the stemness phenotype of TNBC cells investigated. Effects of BCSCs-231-derived CHI3L1 on CTLA4 expression in T cells were explored after co-culture of BCSCs-231 cells obtained from microsphere culture of TN-BCSCs with T cells. BCSCs-231-treated T cells were co-cultured with CD8+ T cells to explore the resultant effect on T cell cytotoxicity. An orthotopic B.C. transplanted tumor model in mice with humanized immune systems was constructed, in which the Role of CHI3L1/MAF/CTLA4 in the immune escape of TNBC was explored.

RESULTS

Eight cell subsets were found in the TNBC tissues, and the existence of TN-BCSCs was observed in the epithelial cell subset. CHI3L1 was related to the stemness phenotype of TNBC cells. TN-BCSC-derived CHI3L1 increased CTLA4 expression in T cells through MAF, inhibiting CD8+ T cell cytotoxicity and inducing immunosuppression. Furthermore, the CTLA4+ T cells might secrete S100A4 to promote the stemness phenotype of TNBC cells.

CONCLUSIONS

TN-BCSC-derived CHI3L1 upregulates CTLA4 expression in T cells through MAF, suppressing the function of CD8+ T cells, which promotes the immune escape of TNBC.

Circ_0004676 exacerbates triple-negative breast cancer progression through regulation of the miR-377-3p/E2F6/PNO1 axis

BACKGROUND

The significant roles of circular RNAs (circRNAs) in different cancers and diseases have been reported. We now focused on the possible role of a newly recognized circRNA, circ_0004674 in triple-negative breast cancer (TNBC), and the related downstream mechanism.

METHODS

The expression of circ_0004674 in TNBC tissues and cells was determined followed by analysis of the correlation between circ_0004674 and TNBC patients' prognosis. The interaction between circ_0004674, miR-377-3p, E2F6, and PNO1 was then identified using bioinformatics analysis combined with FISH, RIP, RNA pull-down, RT-qPCR, and Western blot analysis. Using gain-of-function and loss-of-function methods, we analyzed the effect of circ_0004674, miR-377-3p, E2F6, and PNO1 on TNBC in vivo and in vitro.

RESULTS

Increased circ_0004674 and E2F6 but decreased miR-377-3p were observed in TNBC tissues and MDA-MB-231 TNBC cells, all of which findings were associated with poor prognosis in patients with TNBC. Silencing of circ_0004676 remarkably suppressed the proliferation, cell cycle progression, and migration of TNBC cells in vitro, as well as inhibiting tumorigenesis and metastasis in vivo. Additionally, circ_0004676 served as a sponge of miR-377-3p which bound to the transcription factor E2F6. In the presence of overexpression of circ_0004676, E2F6 expression and its target PNO1 expression were elevated, while miR-377-3p expression was decreased. Interestingly, overexpression of E2F6 could reverse the inhibitory effect on tumor growth caused by downregulation of circ_0004676.

CONCLUSION

Our study highlighted the carcinogenic effect of circ_0004676 on TNBC through regulation of the miR-377-3p/E2F6/PNO1 axis. 1. Circ_0004674 is highly expressed in TNBC tissues and cells. 2. Circ_0004674 upregulates the expression of E2F6 by sponging miR-377-3p. 3. E2F6 upregulates PNO1 by binding to the PNO1 promoter. 4. Circ_0004674 favors TNBC progression by regulating the miR-377-3p/E2F6/PNO1 axis. 5. This study provides a new target for the treatment of TNBC.

Dexmedetomidine inhibits cerebral nerve cell apoptosis after cerebral hemorrhage in rats via the Nrf2/HO-1/NQO1 signaling pathway

OBJECTIVE

To investigate the effect of dexmedetomidine on the apoptosis of cerebral nerve cells after cerebral hemorrhage (CH) in rats and its molecular mechanism.

MATERIALS AND METHODS

The rat model of CH was established by autologous blood injection. A total of 60 specific pathogen-free (SPF)-grade rats were randomly divided into sham-operation group, model group and dexmedetomidine group, and each group involved 20 rats. Rat brain water content was compared among the three groups. Besides, rat neurological function of the three groups was evaluated at 3, 5 and 7 d after operation by neurological function scoring. Western blotting assay was adopted to detect protein levels of apoptosis-related genes [B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax)] in rat brain tissues in the three groups. Moreover, the apoptosis level in the brain tissues in the groups was measured through terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Biochemical tests were conducted to determine activities of reduced glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) in the brain tissues among the three groups. Furthermore, the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1)/NAD(P)H quinone oxidoreductase 1 (NQO1) signaling pathway in the brain tissues of the three groups of rats was examined via Western blotting assay. An in vitro oxygen-glucose deprivation (OGD) model was prepared using SH-SY5Y cells. In addition, Nrf2 was intervened in SH-SY5Y cells by small hairpin ribonucleic acid (shRNA) transfection. Finally, flow cytometry and Annexin V/PI assay were performed to detect the response of cells to dexmedetomidine in OGD + dexmedetomidine + sh-Nrf2 group.

RESULTS

The brain water content and the neurological function score at 3, 5 and 7 d after operation were remarkably reduced in dexmedetomidine group compared with those in model group. The results of Western blotting and TUNEL assays indicated that dexmedetomidine group had a notably lowered apoptosis level in the brain tissues. Additionally, the biochemical test results manifested that activities of GSH and SOD were enhanced and that of MDA decreased in the brain tissues of dexmedetomidine group. Protein levels of Nrf2, HO-1 and NQO1 in the brain tissues were distinctly higher in dexmedetomidine group than those in model group. According to the results of flow cytometry, the apoptosis rate in OGD + dexmedetomidine + sh-Nrf2 group rose prominently compared with that in OGD + dexmedetomidine group.

CONCLUSIONS

Dexmedetomidine inhibits the nerve cell apoptosis in rat brain tissues by activating the Nrf2/HO-1/NQO1 signaling pathway in rat CH models.

Genome-wide identification studies - A primer to explore new genes in plant species

Genome data have accumulated rapidly in recent years, doubling roughly after every 6 months due to the influx of next-generation sequencing technologies. A plethora of plant genomes are available in comprehensive public databases. This easy access to data provides an opportunity to explore genome datasets and recruit new genes in various plant species not possible a decade ago. In the past few years, many gene families have been published using these public datasets. These genome-wide studies identify and characterize gene members, gene structures, evolutionary relationships, expression patterns, protein interactions and gene ontologies, and predict putative gene functions using various computational tools. Such studies provide meaningful information and an initial framework for further functional elucidation. This review provides a concise layout of approaches used in these gene family studies and demonstrates an outline for employing various plant genome datasets in future studies.

Differences in the dielectric properties of various benign and malignant thyroid nodules

PURPOSE

This experiment was conducted to investigate the dielectric properties of different types of thyroid nodules. Our goal was to find a simple and fast method to detect thyroid diseases at different stages from the dielectric properties of thyroid nodules.

METHODS

We used the open-ended coaxial line method to measure the dielectric permittivities of thyroid tissues from 155 patients at frequencies ranging from 1 to 4000 MHz. Tissues that were investigated included normal thyroid tissue and benign and malignant thyroid nodules (nodular goiter, follicular adenoma, papillary carcinoma, and follicular carcinoma), as determined from pathological reports. Differences in dielectric properties were measured between each nodule and the surrounding 1 cm of tissue.

RESULTS

The analysis results revealed that the dielectric permittivity and conductivity values were positively correlated with the degree of malignancy of the nodule (normal < benign < malignant; all differences P < 0.05). This was more obvious at frequencies within 20~70 MHz, following the order normal tissue < nodular goiter < follicular adenoma < papillary carcinoma < follicular carcinoma. A significant difference (P < 0.05) in dielectric permittivity and conductivity was found when comparing these nodules with the surrounding 1 cm of tissue.

CONCLUSIONS

Normal, benign, and malignant nodules were successfully distinguished from one another, and dielectric permittivity was found to be a more sensitive parameter than conductivity. In particular, different disease types can be distinguished at a stimulation frequency of 20~70 MHz, which shows that dielectric properties have application prospects for the detection and diagnosis of cancer. At the same time, the dielectric parameter differences between the surrounding 1 cm of tissue and the diseased nodule can distinguish the tumor and its surrounding tissues in real time during surgery to determine the tumor boundary.

MicroRNA-15a inhibits inflammatory response and apoptosis after spinal cord injury via targeting STAT3

OBJECTIVE

To clarify the function of microRNA-15a in the spinal cord injury (SCI) and its potential mechanism.

PATIENTS AND METHODS

The plasma levels of microRNA-15a and signal transducer and activator of transcription 3 (STAT3) in SCI patients were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The correlation between the expressions of microRNA-15a and STAT3 was analyzed. The in vitro SCI model was established in H2O2-induced C8-D1A and C8B4 cells, and in vivo SCI model was established in mice by hitting T10. The mRNA and protein expressions of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) were detected in the SCI model. The apoptosis was examined by flow cytometry or TUNEL staining, respectively. The motor function of mouse hindlimb was evaluated using the Basso Beattie Bresnahan (BBB) standard scale. The target gene of microRNA-15a was predicted by bioinformatics and further verified by dual-luciferase reporter gene assay. The expression changes of target genes in C8-D1A and C8B4 cells with microRNA-15a overexpression or knockdown were examined by qRT-PCR and Western blot. Finally, rescue experiments were performed to evaluate the regulatory effects of microRNA-15a and STAT3 on cell apoptosis.

RESULTS

MicroRNA-15a was lowly expressed in plasma of SCI patients, while STAT3 was highly expressed with a negative correlation to microRNA-15a. Identically, microRNA-15a was lowly expressed in H2O2-induced C8-D1A and C8B4 cells, and STAT3 was highly expressed. MicroRNA-15a overexpression downregulated mRNA and protein levels of TNF-α and IL-6 in C8-D1A and C8B4 cells. BBB score was markedly low in SCI mice relative to controls. SCI mice injected with microRNA-15a mimics had higher BBB score than those injected with negative control. Besides, SCI mice with microRNA-15a overexpression had downregulated expressions of STAT3, TNF-α, and IL-6 in the impaired spinal cord tissues, as well as lower apoptotic rate. Through bioinformatics, we found binding sites between STAT3 and microRNA-15a. Their binding conditions were further verified by dual-luciferase reporter gene assay. Moreover, STAT3 expression was negatively regulated by microRNA-15a. Finally, rescue experiments showed that STAT3 overexpression could reverse the regulatory effects of microRNA-15a on expressions of TNF-α and IL-6, as well as apoptosis.

CONCLUSIONS

MicroRNA-15a expression decreases in the SCI model, which participates in the process of SCI by regulating inflammatory response and cell apoptosis via targeting STAT3.

lncRNA CASC9 positively regulates CHK1 to promote breast cancer cell proliferation and survival through sponging the miR‑195/497 cluster

Accumulating evidence has demonstrated that long non-coding RNAs (lncRNAs) play important roles in the pathogenesis and development of diverse types of human disorders. Cancer susceptibility candidate 9 (CASC9), a gene encoding a lncRNA, has frequently been reported to be dysregulated and has been implicated in multiple types of human malignancies. However, the biological role of lncRNA CASC9 in breast cancer (BC) remains largely unknown. The present study aimed to investigate the role of lncRNA CASC9 in BC and to elucidate the potential molecular mechanisms involved. In the present study, lncRNA CASC9 was found to be significantly upregulated in both BC tissues and cell lines. Furthermore, functional analyses revealed that lncRNA CASC9 accelerated BC cell proliferation, promoted cell cycle progression and suppressed cell apoptosis. Moreover, mechanical experiments demonstrated that lncRNA CASC9 positively regulated checkpoint kinase 1 (CHK1) by competitively binding to the miR-195/497 cluster in BC cells. Additionally, the knockdown of lncRNA CASC9 was observed to suppress breast tumor growth in vivo. Taken together, the results of this study indicate that lncRNA CASC9 plays an oncogenic role in BC through sponging the miR-195/497 cluster, and that lncRNA CASC9 may be used as a novel therapeutic target and as a potential diagnostic marker for BC.

Parathyroid Hormone-Related Protein (1-40) Enhances Calcium Uptake in Rat Enterocytes Through PTHR1 Receptor and Protein Kinase Cα/β Signaling

BACKGROUND/AIMS

Parathyroid hormone-related protein (PTHrP) is implicated in regulating calcium homeostasis in vertebrates, including sea bream, chick, and mammals. However, the molecular mechanism underlying the function of PTHrP in regulating calcium transport is still not fully investigated. This study aimed to investigate the effect of PTHrP on the calcium uptake and its underlying molecular mechanism in rat enterocytes.

METHODS

The rat intestinal epithelial cell line (IEC-6) was used. Calcium uptake was determined by using the fluo-4 acetoxymethyl ester fluorescence method. The expression levels of RNAs and proteins was assessed by RT-PCR and Western-blot, respectively.

RESULTS

PTHrP (1-40) induced rapid calcium uptake in enterocytes in a dose-dependent manner. PTHrP (1-40) up-regulated parathyroid hormone 1 receptor (PTHR1) protein but not 1,25D3-MARRS receptor. Pre-treatment of anti- PTHR1 antibody abolished the PTHrP (1-40)-induced calcium uptake. PTHrP (1-40) significantly up-regulated four transcellular calcium transporter proteins, potential vanilloid member 6 (TRPV6), calbindin-D9k (CaBP-D9k), sodium-calcium exchanger 1 (NCX1) and plasma membrane calcium ATPase 1 (PMCA1), in a dose- and time-dependent manner. Pre-treatment with TRPV6 or CaBP-D9k antibodies or knockout of rat TRPV6 or CaBP-D9k markedly inhibited PTHrP (1-40)-induced calcium uptake, whereas inhibition of NCX or PMCA1 by antibodies or inhibitors had no effect on PTHrP(1-40)-induced calcium uptake. Furthermore, PTHrP (1-40) treatment up-regulated protein levels of protein kinase C (PKC α/β) and protein kinase A (PKA). Pretreatment of PKC α/β inhibitor (but not PKA inhibitor) inhibited PTHrP (1-40)-induced calcium uptake.

CONCLUSION

PTHrP (1-40) stimulates calcium uptake via PTHR1 receptor and PKC α/β signaling pathway in rat enterocytes, and calcium transporters TRPV6 and CaBP-D9k are necessary for this stimulatory effect.

Transarterial chemoembolisation for breast cancer with liver metastasis: A systematic review

BACKGROUND

There is limited data on the impact of transarterial chemoembolisation (TACE) on survival in patients of breast cancer with liver metastasis (BCLM).

METHODS

A systematic review was conducted to assess TACE effect on BCLM patients. A search for clinical studies published since 1/1/2000 to 1/1/2017 was performed. Survival data from all studies were extracted to evaluate the efficacy of TACE, including overall survival, disease free survival and response rate. Toxic side effects data were also extracted to assess the safety of TACE.

RESULTS

A total of 10 studies with 519 BCLM patients were identified. 78.0% patients were treated with TACE, 9.9% were treated with TACE plus systematic chemotherapy and 12.1% were treated with systematic chemotherapy alone. Pooled median overall survival of patients who received TACE ranged from 7.3 to 47.0 months, median disease free survival ranged from 2.9 to 17.0 months and response rates ranged from 7.0 to 73.5%. Pooled Grade 3 and 4 side effects (blood toxicities, liver toxicity and post-embolization syndrome) ranged from 0.0 to 17.4%.

CONCLUSIONS

TACE is one of an effective treatment for BCLM and whether a specific patient is appropriate to receive TACE depends on a multiple disciplinary team discussion.

Cancer-Associated Fibroblasts Autophagy Enhances Progression of Triple-Negative Breast Cancer Cells

BACKGROUND Cancer-associated fibroblasts (CAFs) are key factors in malignant tumor initiation, progression, and metastasis. However, the effect of CAFs autophagy on triple-negative breast cancer (TNBC) cells is not clear. In this study, the growth effect of TNBC cells regulated by CAFs autophagy was evaluated. MATERIAL AND METHODS CAFs were obtained from invasive TNBC tumors and identified by Western blot and immunofluorescence staining assay. CAFs were co-cultured with TNBC cells, and migration and invasion were evaluated by Matrigel-coated Transwell and Transwell inserts. TNBC cells growth was detected by MTT assay, and epithelial-mesenchymal transition (EMT) regulated by CAFs was evaluated by Western blot assay. RESULTS CAFs were identified by the high expression of α-smooth muscle actin (α-SMA) protein. Autophagy-relevant Beclin 1 and LC3-II/I protein conversion levels in CAFs were higher than those in NFs (P<0.05). TNBC cells migration, invasion, and proliferation levels were significantly improved in the CAFs-conditioned medium (CAFs-CM) group, compared with the other 3 groups (P<0.05). TNBC cells vimentin and N-cadherin protein levels were upregulated and E-cadherin protein level was downregulated in the CAFs-CM group compared with the control group (P<0.05). Further study indicated b-catenin and P-GSK-3β protein levels, which are the key proteins in the Wnt/β-catenin pathway, were upregulated in the CAFs-CM group compared with the control group (P<0.05). CONCLUSIONS Our data demonstrated CAFs autophagy can enhance TNBC cell migration, invasion, and proliferation, and CAFs autophagy can induce TNBC cells to engage in the EMT process through the Wnt/β-catenin pathway.

Protein arginine methyltransferase 5 functions as an epigenetic activator of the androgen receptor to promote prostate cancer cell growth

Protein arginine methyltransferase 5 (PRMT5) is an emerging epigenetic enzyme that mainly represses transcription of target genes via symmetric dimethylation of arginine residues on histones H4R3, H3R8 and H2AR3. Accumulating evidence suggests that PRMT5 may function as an oncogene to drive cancer cell growth by epigenetic inactivation of several tumor suppressors. Here, we provide evidence that PRMT5 promotes prostate cancer cell growth by epigenetically activating transcription of the androgen receptor (AR) in prostate cancer cells. Knockdown of PRMT5 or inhibition of PRMT5 by a specific inhibitor reduces the expression of AR and suppresses the growth of multiple AR-positive, but not AR-negative, prostate cancer cells. Significantly, knockdown of PRMT5 in AR-positive LNCaP cells completely suppresses the growth of xenograft tumors in mice. Molecular analysis reveals that PRMT5 binds to the proximal promoter region of the AR gene and contributes mainly to the enriched symmetric dimethylation of H4R3 in the same region. Mechanistically, PRMT5 is recruited to the AR promoter by its interaction with Sp1, the major transcription factor responsible for AR transcription, and forms a complex with Brg1, an ATP-dependent chromatin remodeler, on the proximal promoter region of the AR gene. Furthermore, PRMT5 expression in prostate cancer tissues is significantly higher than that in benign prostatic hyperplasia tissues, and PRMT5 expression correlates positively with AR expression at both the protein and mRNA levels. Taken together, our results identify PRMT5 as a novel epigenetic activator of AR in prostate cancer. Given that inhibiting AR transcriptional activity or androgen synthesis remains the major mechanism of action for most existing anti-androgen agents, our findings also raise an interesting possibility that targeting PRMT5 may represent a novel approach for prostate cancer treatment by eliminating AR expression.

The role of video-assisted thoracoscopic surgery in management of the multiple ground-glass nodules

OBJECTIVE

We investigated the outcomes of patients with multiple ground-glass nodules (GGNs) to identify the role of video-assisted thoracoscopic surgery (VATS) in diagnosis and treatment.

PATIENTS AND METHODS

We included patients with multiple GGNs who were qualified for thoracoscopic surgery resection and analyzed the statistics.

RESULTS

Fifty-one GGNs were detected in 21 patients. There were 40 pure GGNs and 11 part-solid ones. Around 46 of the 51 lesions were resected via VATS. Four pure GGNs <10 mm and deep in the lung were proceeded with continuous follow-up. One pure GGN measuring 16 mm considered as subnodule and also deep in the lung underwent stereotactic ablative radiotherapy. Resection methods included lobectomy (1), segmentectomy (1), lobectomy + segmentectomy (6), lobectomy + wedge resection (10), and segmentectomy + wedge resection (3). Of the 46 resected lesions, 4 (8.7%) were atypical adenomatous hyperplasia (AAH), 23 (50%) were adenocarcinoma in situ(AIS), 15 (32.7%) were minimally invasive adenocarcinoma (MIA), 2 (4.3%) were invasive adenocarcinoma, one was pulmonary sclerosing hemangioma, and one was nonspecific fibrosis. Intersegmental lymph node metastasis was found in one of the 21 patients. No postoperational complication occurred in any of the patients.

CONCLUSION

Multiple GGNs were generally independent primary lung cancers, mainly including AAH, AIS, MIA, rather than intrapulmonary metastasis. VATS was superior to thoracotomy for less invasive and shorter hospital stay.

Anti-inflammatory effects of three kinds of traditional Mongolian medicine monomer and its combination on LPS-stimulated RAW264.7 macrophages

OBJECTIVE

Traditional Mongolian Medicine (TMM) exhibits useful biological activities including antifungal, antibacterial, and anti-inflammatory actions. The mechanisms of TMM in anti-inflammation were still unclear. The aim of this study was to investigate the effects of the three main monomers (geniposide, gallate, berberine hydrochloride and a mixture of them) of a traditional Mongolian medicine on cell survival and the proinflammatory cytokines signaling pathways which are activated by bacterial lipopolysaccharides (LPS).

MATERIALS AND METHODS

Mouse macrophage-like cell line RAW264.7 was used as a model of inflammation to investigate the anti-inflammatory effects of three TMM momomers and their combination. RT-PCR and Western blot was used to quantify the change of mRNA and protein levels of cytokines, Toll-like receptor-4 (TLR4) and Nuclear Factor-κB (NF-κB) and its inhibitor IκB. The non-radioactive electrophoresis mobility shift assay (EMSA) was used to evaluate the binding activity of NF-κB.

RESULTS

The monomers and their combination exhibited a potent anti-inflammatory effect for suppressing the LPS-evoked secretion of proinflammatory cytokines IL-1β, IL-6 and TNFα. Furthermore, the monomers and their combination attenuated activation of NF-κB and expression of TLR4 at both mRNA and protein levels, the upstream player of the LPS-TLR4-cytokines/ NF-κB signaling pathway.

CONCLUSIONS

The Mongolia herbal compound exerts a potent anti-inflammatory effect and could potentially be developed as a useful agent for the chemo-prevention of inflammatory diseases.

Complex doping chemistry owing to Mn incorporation in nanocrystalline anatase TiO2 powders

Mn-doped TiO2 powders with a wide range of nominal doping levels were fabricated using a one-step hydrothermal method followed by 400 °C annealing. Anatase powders with a uniform size distribution below 10 nm were obtained. The maximum solubility of Mn in the TiO2 lattice was around 30%, beyond which the Mn3O4 compound appeared as a secondary phase. The optical absorption edges for Mn-doped anatase TiO2 were red-shifted effectively through increasing Mn content. Alloying chemistry and associated elemental valences were elaborated through combining X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and theoretical simulation in the framework of density functional theory (DFT). The results showed that the Mn species exhibited mixed valence states of 3+ and 4+ in anatase TiO2, with the latter being the key to remarkable photocatalytic performance.

DNAzyme-based probe for circulating microRNA detection in peripheral blood

BACKGROUND

The recent discovery of microRNAs (miRNAs) and their extracellular presence suggest a potential role of these regulatory molecules in defining the metastatic potential of cancer cells and mediating the cancer-host communication. This study aims to improve the sensitivity of miRNA detection via DNAzyme-based method and enhance the selectivity by using the DNAzyme-based probe to reduce nonspecific amplification.

METHODS

The miRNA probes were chemically synthesized with a phosphate at the 5' end and purified by polyacrylamide gel electrophoresis. Exosomal RNA from peripheral blood was isolated. Carboxylated magnetic microsphere beads (MBs) were functionalized with streptavidin (SA) according to a previously reported method with some modification. T capture probe-coated SA-MBs (DNA-MBs) were also prepared. The fluorescent spectra were measured using a spectrofluorophotometer.

RESULTS

We designed an incomplete DNAzyme probe with two stems and one bubble structure as a recognition element for the specific detection of miRNA with high sensitivity. The background effects were decreased with increase of the added of DNA-MBs and capturing times. Therefore, 20 minutes was selected as the optimal concentration in the current study. The fluorescence intensity increases as the hybridization time changed and reached a constant level at 40 minutes, and 1 μM is the optimum signal probe concentration for self-assembled DNA concatemers formation. In the presence of miRNA, the fluorescence of the solution increased with increasing miRNA concentration. There is no obvious fluorescence in the presence of 10 mM of other nontarget DNA.

CONCLUSION

A simple, rapid method with high performance has been constructed based on identified circulating miRNA signatures using miRNA-induced DNAzyme. This assay is simple, inexpensive, and sensitive, enabling quantitative detection of as low as 10 fM miRNA.

The latest progress in research on triple negative breast cancer (TNBC): risk factors, possible therapeutic targets and prognostic markers

Triple negative breast cancer (TNBC) is one type of breast cancer (BC), which is defined as negative for estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (Her2). Its origins and development seem to be elusive. And for now, drugs like tamoxifen or trastuzumab which specifically apply to ER, PR or Her2 positive BC seem unforeseeable in TNBC clinical treatment. Due to its extreme malignancy, high recurrence rate and poor prognosis, a lot of work on the research of TNBC is needed. This review aims to summarize the latest findings in TNBC in risk factors, possible therapeutic targets and possible prognostic makers.

Endoscopic axillary lymphadenectomy combined with laparoscopically harvested pedicled omentum for immediate breast reconstruction

BACKGROUND

To determine the therapeutic and cosmetic outcomes of patients with breast cancer treated with endoscopic axillary lymphadenectomy (EAL) combined with laparoscopically harvested pedicled omentum (LHPO) for immediate breast reconstruction.

METHODS

Forty patients with early breast cancer underwent EAL, followed by quadrantectomy and LHPO for immediate breast reconstruction. All patients were evaluated for operating time, blood loss, postoperative hospital stay, complications, etc. The cosmetic outcomes were evaluated 6 months after the surgery, according to the Harris criteria.

RESULTS

The average operating time was 308 min, including 39 min for EAL, 63 min for quadrantectomy, and 58 min for LHPO. The average blood loss was 70 ml, and was mainly incurred during breast resection. On average, the patients were discharged 9.5 days after the surgery. Partial graft necrosis and omental fat liquefaction occurred in one patient each. No other complications occurred after the surgery. No local recurrence or distant metastasis was found during the follow-up. The cosmetic results were mostly satisfactory. No size reduction of the reconstructed breast occurred after radiation therapy. Esthetic evaluation of the reconstructed breast showed that the cosmetic outcome was "excellent" in 35 patients, "good" in 4 patients, and "fair" in 1 patient.

CONCLUSIONS

EAL combined with LHPO for breast reconstruction is a viable, safe procedure that causes minimal surgical trauma and results in a soft, shapely breast postoperatively.

K63-linked ubiquitination of FANCG is required for its association with the Rap80-BRCA1 complex to modulate homologous recombination repair of DNA interstand crosslinks

DNA interstrand crosslinks (ICLs) are extremely deleterious lesions that are repaired by homologous recombination (HR) through coordination of Fanconi anemia (FA) proteins and breast cancer susceptibility gene 1 (BRCA1) product, but the exact role these proteins have remains unclear. Here we report that FANCG was modified by the addition of lysine63-linked polyubiquitin chains (K63Ub) in response to DNA damage. We show that FANCG K63Ub was dispensable for monoubiquitination of FANCD2, but was required for FANCG to interact with the Rap80-BRCA1 (receptor-associated protein 80-BRCA1) complex for subsequent modulation of HR repair of ICLs induced by mitomycin C. Mutation of three lysine residues within FANCG to arginine (K182, K258 and K347, 3KR) reduced FANCG K63Ub modification, as well as its interaction with the Rap80-BRCA1 complex, and therefore impeded HR repair. In addition, we demonstrated that K63Ub-modified FANCG was deubiquitinated by BRCC36 complex in vitro and in vivo. Inhibition of BRCC36 resulted in increased K63Ub modification of FANCG. Taken together, our results identify a new role of FANCG in HR repair of ICL through K63Ub-mediated interaction with the Rap80-BRCA1 complex.

Analysis of survival factors in patients with intermediate-advanced hepatocellular carcinoma treated with transcatheter arterial chemoembolization combined with sorafenib

PURPOSE

To retrospectively analyze the efficacy and safety of transcatheter arterial chemoembolization (TACE) in combination with sorafenib for the treatment of patients with intermediate-advanced hepatocellular carcinoma (HCC) and assess the prognostic impact of baseline characteristics.

METHODS

Patients with intermediate-advanced HCC received TACE combined with sorafenib in this Phase 2 clinical trial. The primary outcome was median time to disease progression (mTTP). Secondary outcomes were median overall survival (mOS), the disease benefit rate and the sorafenib-related adverse events (AEs). Baseline characteristics' impacts on prognosis were analyzed by univariate COX proportional hazards regression model.

RESULTS

From June 2008 to June 2013, 75 patients were enrolled. At the end of the study, 54 patients were dead or lost to follow-up and 21 patients survived. This combination therapy resulted in a mTTP of 7.09 months (95 % CI, 1.5-45 months) and a mOS of 11.44 months (95 % CI, 1.5-45 months). The disease benefit rate was 88 %. Child-Pugh score (P = 0.000), Eastern Cooperative Oncology Group performance status (P = 0.001), Barcelona Clinic Liver Cancer stage (P = 0.000), sorafenib treatment regimen (P = 0.001), presence of extrahepatic metastasis (P = 0.002), and type of tumor (P = 0.027) were significantly correlated with OS. Multivariate analysis revealed Child-Pugh score (P = 0.001) and BCLC stage (P = 0.002) as significant independent prognostic predictors for OS. AEs were HFSR (18.7 %), gastrointestinal reactions (13.3 %), liver dysfunction (6.7 %), myelosuppression (5.3 %), fatigue (4 %), and hypertension (1.3 %).

CONCLUSIONS

TACE in combination with sorafenib might have acceptable safety and efficiency in the treatment of intermediate-advanced HCC.

Novel ZnO nanorod films by chemical solution deposition for planar device applications

Smooth and continuous ZnO films consisting of densely packed ZnO nanorods (NRs), which can be used for electronic device fabrication, were synthesized using a hydro-thermo-chemical solution deposition method. Such devices would have the novelty of high performance, benefiting from the inherited unique properties of the nanomaterials, and can be fabricated on these smooth films using a conventional, low cost planar process. Photoluminescence measurements showed that the NR films have much stronger shallow donor to valence band emissions than those from discrete ZnO NRs, and hence have the potential for the development of ZnO light emission diodes and lasers, etc. The NR films have been used to fabricate large area surface acoustic wave devices by conventional photolithography. These demonstrated two well-defined resonant peaks and their potential for large area device applications. The chemical solution deposition method is simple, reproducible, scalable and economic. These NR films are suitable for large scale production on cost-effective substrates and are promising for various fields such as sensing systems, renewable energy and optoelectronic applications.

Downregulation of miRNA-128 sensitises breast cancer cell to chemodrugs by targeting Bax

miR-128 is more highly expressed in drug-resistant breast cancer samples than in drug-sensitive samples. We have confirmed that Bax is the target of miR-128 by negative post-transcriptional regulation. miR-128 and Bax were detected in the breast cancer cell line, MDA-MB-231, which was then transfected with miR-128 MIMIC (precursor of miR-128) or AMO (antisense-miR-128 oligonucleotides). After transfection, the chemosensitivity of MDA-MB-231 cell was up-regulated with increasing of Bax and inhibition of miR-128.

Abstract P6-04-12: Novel selective estrogen receptors degraders regress tumors in pre-clinical models of endocrine-resistant breast cancer

80% of all breast cancers express the estrogen receptor alpha (ERα) and thus are treated with anti-hormonal therapies that directly block ER function (e.g. Tamoxifen) or hormone synthesis (Aromatase Inhibitors). While these therapies are initially effective, acquired resistance invariably emerges. Importantly, the majority of these tumors continue to depend on ERα for growth and survival. The emerging evidence that ERα can signal in both a ligand-dependent and ligand-independent manner supports the development of agents that are not only competitive ERα antagonists but also reduce steady state levels of the receptor and thus limit both modes of signaling.

We have identified novel, non-steroidal ERα antagonists that induce degradation of ERα in breast cancer cell lines at picomolar concentrations resulting in significant reduction in steady state ERα protein levels. Using peptide-based conformational profiling, we show that these Selective Estrogen Receptor Degraders (SERDs) induce estrogen receptor conformations that are distinct from both fulvestrant and tamoxifen indicating a unique mechanism of action. This unique biological profile coupled with good oral pharmacokinetics produces tumor regressions in both tamoxifen-sensitive and -resistant models of breast cancer in vivo. Recent pre-clinical and clinical data indicate that PI3K pathway signaling can contribute to the endocrine resistant state. In a preclinical model of tamoxifen resistant breast cancer in which SERD monotherapy only produces tumor growth inhibition, SERD therapy in combination with torc1/2 inhibition results in frank tumor regressions. These orally bioavailable SERDs hold promise as a next generation therapy for the treatment of ER+ breast cancer as monotherapy, as well as in combination with agents that target other pathways involved in both intrinsic and acquired endocrine resistance.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-04-12.

Investigation of the hydrogen bonding in ice Ih by first-principles density function methods

It is a well recognized difficult task to simulate the vibrational dynamics of ices using the density functional theory (DFT), and there has thus been rather limited success in modelling the inelastic neutron scattering (INS) spectra for even the simplest structure of ice, ice Ih, particularly in the translational region below 400 cm(-1). The reason is partly due to the complex nature of hydrogen bonding (H-bond) among water-water molecules which require considerable improvement of the quantum mechanical simulation methods, and partly owing to the randomness of protons in ice structures which often requires simulation of large super-lattices. In this report, we present the first series of successful simulation results for ice Ih using DFT methods. On the basis of the recent advancement in the DFT programs, we have achieved for the first time theoretical outcomes that not only reproduce the rotational frequencies between 500 to 1200 cm(-1) for ice Ih, but also the two optic peaks at ∼240 and 320 cm(-1) in the translational region of the INS spectra [J. C. Li, J. Chem. Phys 105, 6733 (1996)]. Besides, we have also investigated the impact of pairwise configurations of H(2)O molecules on the H-bond and found that different proton arrangements of pairwise H(2)O in the ice Ih crystal lattice could not alter the nature of H-bond as significantly as suggested in an early paper [J. C. Li and D. K. Ross, Nature (London) 365, 327 (1993)], i.e., reproducing the two experimental optic peaks do not need to invoke the two H-bonds as proposed in the previous model which led to considerable debates. The results of this work suggest that the observed optic peaks may be attributed to the coupling between the two bands of H-O stretching modes in H(2)O. The current computational work is expected to shed new light on the nature of the H-bonds in water, and in addition to offer a new approach towards probing the interaction between water and biomaterials for which H-bond is essential.

Expression of SP-C and Ki67 in lungs of preterm infants dying from respiratory distress syndrome

This study aimed at exploring the expression of Surfactant protein-C (SP-C) and Ki67 in autopsy lung tissues of premature infants dying from respiratory distress syndrome (RDS) who were exposed to mechanical ventilation and elevated oxygen concentrations. The possible influence of pulmonary surfactant (PS) on the expression of SP-C and Ki67 was also investigated. Thirty preterm infants were selected who were histologically and clinically diagnosed as RDS. Preterm infants with RDS were divided into 4 groups, according to the time of death: infants ventilated for 1–3 days, 4–8 days, 9–16 days and >6 days. Five premature infants died within 1 day after delivery for non- pulmonary reasons served as controls. The expression of SP-C and Ki67 in lungs was detected by immunohistochemistry. Compared with the control group, the expression of SP-C and Ki67 in RDS infants decreased significantly after 1–3 days of ventilation, but increased after 4 days and reached peak value after 9–16 days. No significant difference in the expression of SP-C and Ki67 was found between infants treated with PS and those without. Thus our results suggest SP-C and Ki67 may have participated in the pulmonary pathological process in ventilated/oxygen treated preterm infants with RDS, and exogenous surfactant had no effect on the expression of SP-C and Ki67 in the lungs of ventilated/oxygen treated preterm infants with RDS.

Metastable Phase Transformations in Ti-40Al-10V Alloy

The microstructures in arc melted ingots and melt spun ribbons have been investigated by electron microscopy and thermodynamic modelling has been used to study the phase transformations. In the ingot, solidification starts with the bcc β phase and at room temperature the structure consists of B2, ωordered, γ and α2 phases. The calculated equilibrium phase transformation sequence during cooling is L → L+ β→β→β + α→β2+α → α+β2+γ → α2+γ + B2. The phase transformation sequence is dramatically changed by rapid quenching from the melt. Athermal ordered w phase is formed in metastable B2 and the α→α2 ordering process is completely suppressed in the melt spun ribbons. The volume fraction of the α precipitates is also dependent on cooling rates.

Calculation of Phase Competition and Selection in Solidification Using a Combined Nucleation and Calphad Approach

Thermodynamic data derived by the CALPHAD method has been extended to undercooled melts to study phase competition and the role of time dependent and steady state nucleation in rapidly solidified materials. The theoretical predictions made about phase competition between hcp α, bcc β and Ll0 γ in some Al(Ti,V) alloys are compared with experimental results. It is shown that high melt cooling rates introduce significant transient nucleation effects on phase nucleation.

Use of chemical characteristics to predict the relative bioavailability of supplemental organic manganese sources for broilers1

Twelve organic Mn sources and MnSO4 were evaluated by polarographic analysis and via solubility in buffers (pH 5 and 2) and deionized water. Fractions from solubility tests were evaluated by gel filtration chromatography for structural integrity. Organic Mn sources included five Mn methionine complexes (Mn Met A to Mn Met E), two Mn proteinates (Mn Pro A and Mn Pro B), and five Mn amino acids (Mn AA A to Mn AA E). Sources varied considerably in chemical characteristics. Chelation strength (Qf) ranged from weak (1.9 Qf-values) to strong complexes (115.4 Qf-values). No complexed Mn was found in filtrates at pH 2.0 or 5.0. A 42-d bioassay was used to estimate relative bioavailability of Mn sources for chicks fed diets supplemented with 60, 120, or 180 mg Mn/kg. Bone Mn, heart Mn, heart manganese-superoxide dismutase activity (MnSOD), and heart MnSOD mRNA increased (P < 0.001) as dietary Mn increased. Only heart MnSOD mRNA tended (P < 0.10) to differ among dietary Mn sources. For bioassays of Mn, the MnSOD mRNA level in heart was more sensitive than the MnSOD activity in heart or other indices. Relative to MnSO4 (assigned 100%), slope ratios of MnSOD mRNA levels in heart gave bioavailabilities of 99, 132, and 113% for Mn Met E, Mn AA B, and Mn AA C sources with weak, moderate, and strong chelation strength, respectively. The bioavailability of Mn was more closely related to chelation strength as measured by polarography than to chemical traits assessed by solubility or structural integrity.

[Imaging evaluation and interventional therapy of hepatic metastases from small intestinal leiomyosarcoma]

OBJECTIVE

To evaluate the imaging appearances and the short-term curative effect of hepatic metastases from small intestine leiomyosarcoma treated by interventional methods.

METHODS

Seven cases with 46 lesions of hepatic metastases from small intestinal leiomyosarcoma were analyzed retrospectively. The diameters of the metastases were from 2 cm to 18 cm. CT triphasic scan and hepatoarterial angiography were performed in all cases. The interventional therapy methods included transcatheter arterial chemoembolization (TACE) (all 7 cases), percutaneous left subclavian artery port-catheter system implantation (PCS) (1 case). Three cases were also treated with percutaneous tumor necrosis drainage (PTND) because of obvious liquefaction necrosis within the tumor.

RESULTS

The lesions were substantial occupation and some were mixed density with cystic component. The cystic component increased in the larger tumor. The hepatic metastases were enhanced remarkably during the hepatic arterial-dominant phase scan and had abundant tumor vascular and tumor stain on hepatoarterial angiography. The size of tumor in 4 cases was reduced after TACE. The tumor in the patient who was treated with PCS had no changed. The size of the tumor in 3 cases was slightly enlarged. The tumors in the 3 patients treated with PTND were reduced remarkably.

CONCLUSIONS

The predominant blood-supply of the hepatic metastases from small intestinal leiomyosarcoma is the hepatic artery abundant in blood vessels. TACE, PCS and PTND are effective methods to treat hepatic metastases from small intestinal leiomyosarcoma.

Ligand-dependent degradation of retinoid X receptors does not require transcriptional activity or coactivator interactions

Cells utilize ubiquitin-mediated proteolysis to regulate the activity of numerous proteins involved in signal transduction, cell cycle control, and transcriptional regulation. For a number of transcription factors, there appears to be a direct correlation between transcriptional activity and protein instability, suggesting that cells use targeted destruction as one method to down-regulate or attenuate gene expression. In this report we demonstrate that retinoid X receptors (RXRs) which function as versatile mediators of nuclear hormone-dependent gene expression are marked for destruction upon binding agonist ligands. Interestingly, when RXR serves as a heterodimeric partner for retinoic acid (RAR) or thyroid hormone (TR) receptors, binding of agonists by RAR or TR leads to degradation of both the transcriptionally active RAR or TR subunits as well as the transcriptionally inactive RXR subunit. Furthermore, using a series of mutants in the ligand-dependent activation domain (activation function 2), we demonstrate that agonist-stimulated degradation of RXR does not require corepressor release, coactivator binding, or transcriptional activity. Taken together, the data suggest a model for targeted destruction of transcription factors based on structural or conformational signals as opposed to functional coupling with gene transcription.

An efficient room-temperature silicon-based light-emitting diode

There is an urgent requirement for an optical emitter that is compatible with standard, silicon-based ultra-large-scale integration (ULSI) technology. Bulk silicon has an indirect energy bandgap and is therefore highly inefficient as a light source, necessitating the use of other materials for the optical emitters. However, the introduction of these materials is usually incompatible with the strict processing requirements of existing ULSI technologies. Moreover, as the length scale of the devices decreases, electrons will spend increasingly more of their time in the connections between components; this interconnectivity problem could restrict further increases in computer chip processing power and speed in as little as five years. Many efforts have therefore been directed, with varying degrees of success, to engineering silicon-based materials that are efficient light emitters. Here, we describe the fabrication, using standard silicon processing techniques, of a silicon light-emitting diode (LED) that operates efficiently at room temperature. Boron is implanted into silicon both as a dopant to form a p-n junction, as well as a means of introducing dislocation loops. The dislocation loops introduce a local strain field, which modifies the band structure and provides spatial confinement of the charge carriers. It is this spatial confinement which allows room-temperature electroluminescence at the band-edge. This device strategy is highly compatible with ULSI technology, as boron ion implantation is already used as a standard method for the fabrication of silicon devices.

[Relationship between CYP1A1, GSTM1 genetic polymorphisms and susceptibility to esophageal squamous cell carcinoma]

OBJECTIVE

To investigate the association between susceptibility of esophageal squamous cell carcinoma and the genetic polymorphisms of CYP1A1 and GSTM1.

METHODS

Subjects were comprised of 107 esophageal cancer patients and 111 healthy controls. Genotyping of both CYP1A1 and GSTM1 were performed in cancer tissues of all 107 patients and peripheral blood leukocytes taken from the controls by polymerase chain reaction.

RESULTS

There were no significant differences in the frequency distribution of CYP1A1 polymorphisms between esophageal cancer patients and healthy controls although the frequency of CYP1A1 with at least one allele of Val showed slightly higher in individuals with esophageal cancer. However, significant difference was observed in the frequency of GSTM1-nulled individuals with esophageal cancer comparing with the controls (P < 0.05). When subjects were categorized by both CYP1A1 genotype and GSTM1 genotype, GSTM1 (-) became markedly expressed in patients with CYP1A1 (I/I) than in the corresponding controls (67% versus 40%, P < 0.01). The frequency of CYP1A1 genotype with at least one allele of Val (I/V and V/V) was also statistically higher in patients with GSTM1 (+), comparing to the corresponding controls (64% versus 41%, P < 0.05).

CONCLUSIONS

It was suggested that: genetic polymorphisms of CYP1A1 and GSTM1 were susceptible to esophageal cancer; individuals who are GSTM1-null have an increased risk of developing esophageal cancer; individuals with combined CYP1A1 (I/I) and GSTM1 (-) or with combined CYP1A1 (I/V, V/V) and GSTM1 (+) were more susceptible, when comparing to those with combined CYP1A1 (I/I) and GSTM1 (+).

Three amino acids specify coactivator choice by retinoid X receptors

Binding of agonists to nuclear receptors results in a conformational change in receptor structure that promotes interaction between activated receptors and coactivators. Receptor-coactivator interactions are mediated by the agonist-dependent formation of a hydrophobic pocket on the part of receptors, and short leucine-rich sequences termed LxxLL motifs or nuclear receptor boxes present in coactivators. RXR-PPARgamma (retinoid X receptor-peroxisome proliferator-activated receptor-gamma) heterodimers play important roles in adipocyte and macrophage differentiation and have been implicated as therapeutic targets in diabetes, atherosclerosis, and cancer. Analysis of interactions between RXR-PPARgamma heterodimers and coactivator nuclear receptor boxes suggests that RXR and PPARgamma can distinguish among coactivators by recognizing distinct structural features of nuclear receptor boxes. The results also indicate that coactivator choice by RXR is mediated by three nonconserved amino acids of the nuclear receptor box. The ability of an optimized seven-amino acid nuclear receptor box to specifically interact with RXR and function as a selective inhibitor suggests the coactivator-binding pocket may serve as a new target for drug discovery.

China's forest policy for the 21st century

A half-century policy of forest exploitation and monoculture in China has led to disastrous consequences, including degradation of forests and landscapes, loss of biodiversity, unacceptable levels of soil erosion, and catastrophic flooding. A new forest policy had been adopted in China called the Natural Forest conservation Program (NFCP), which emphasizes expansion of natural forests and increasing the productivity of forest plantations. Through locally focused management strategies, biodiversity and forest resources will be sustained, and downstream regions will be better protected from flooding. This new policy is being implemented with a new combination of policy tools, including technical training and education, land management planning, mandatory conversion of marginal farmlands to forest, resettlement and retaining of forest dwellers, share in private ownership, and expanded research. These policy tools may have wider relevance for other countries, particularly developing countries.