circNFIB decreases synthesis of arachidonic acid and inhibits breast tumor growth and metastasis.

We identified circNFIB (hsa_circ_0086376) as a down-regulated circRNA in breast cancer but its effect is unclear. We aimed to explore the roles of circNFIB in breast cancer. The expression levels of circNFIB in breast cancer tissues and cells were detected. Both in vitro and in vivo experiments were used to assess the effects and mechanisms of circNFIB. circNFIB was down-regulated in 29 breast cancer tissues compared to adjacent normal tissues. circNFIB is a highly conserved circRNA and mainly located in cytoplasm of breast cancer cells. In vitro experiments showed that overexpression of circNFIB inhibited proliferation and invasion of breast cancer cells, whereas knockdown of circNFIB induced proliferation and invasion. Animal experiments indicated that circNFIB inhibited tumor growth and metastasis in vivo. Bioinformatics analysis showed that circNFIB contained an open reading frame (ORF) spanning its spliced junction, an internal ribosome entry site (IRES) and a N6-methyladenosine (m6A) site, suggesting circNFIB had the potential to encode a 56 amino acid (aa) protein, which was then confirmed by experiments. Metabonomics analysis results indicated that circNFIB may inhibit synthesis of arachidonic acid (AA) by regulating phospholipase. EIF4A3 and U2AF65 may regulate circNFIB expression by binding to the flanking sequence of circNFIB. In conclusion, circNFIB is a down-regulated circRNA in breast cancer tissues and encodes a 56 aa protein. circNFIB down-regulates AA in breast cancer cells, thus decreasing AA metabolites. Based on reported evidences of AA metabolites on cancer, we speculated that circNFIB may inhibit breast tumor growth and metastasis partly by inhibiting AA.

CD44 is a potential immunotherapeutic target and affects macrophage infiltration leading to poor prognosis.

CD44 plays a key role in the communication of CSCs with the microenvironment and the regulation of stem cell properties. UALCAN was used to analyze the expression of CD44 in bladder cancer (BLCA) and normal tissue. The UALCAN was utilized to analyze the prognostic value of CD44 in BLCA. The TIMER database was used to explore the relationship between CD44 and PD-L1; CD44 and tumor-infiltrating immune cells. The regulatory effect of CD44 on PD-L1 was verified by cell experiments in vitro. IHC confirmed the results of the bioinformatics analysis. GeneMania and Metascape were used to analyze protein-protein interaction (PPI) investigations and functional enrichment analysis. We found that BLCA patients with high CD44 expression had worse survival than those with low CD44 expression (P < 0.05). IHC and the TIMER database results showed that CD44 expression was positively correlated with PD-L1 expression (P < 0.05). At the cellular level, the expression of PD-L1 was significantly inhibited after CD44 expression was inhibited by siRNA. Immune infiltration analysis showed that CD44 expression levels in BLCA were significantly correlated with immune infiltration levels of different immune cells. IHC staining results further confirmed that the expression of CD44 in tumor cells was positively associated with the number of CD68+ macrophages and CD163+ macrophages (P < 0.05). Our results suggest that CD44 is a positive regulator of PD-L1 in BLCA and may be a key regulator of tumor macrophages infiltration and may be involved in M2 macrophage polarization. Our study provided new insights into the prognosis and immunotherapy of BLCA patients through macrophage infiltration and immune checkpoints.

Dioscin modulates macrophages polarization and MDSCs differentiation to inhibit tumorigenesis of colitis-associated colorectal cancer.

It has been reported that colitis is one of risk factors in colorectal cancer (CRC). Intervention of intestinal inflammation and in the early stage of tumorigenesis is of great significance to control the incidence and mortality of CRC. In recent years, natural active products of traditional Chinese medicine have been confirmed that they had made great progress in disease prevention. Here, we showed that Dioscin, a natural active product of Dioscorea nipponica Makino, inhibited initiation and tumorigenesis of AOM/DSS-induced colitis-associated colon cancer (CAC), including alleviating colonic inflammation, improving intestinal barrier function and decreasing tumor burden. In addition, we also explored the immunoregulatory effect of Dioscin on mice. The results showed that Dioscin modulated M1/M2 macrophages phenotype in spleen and decreased monocytic myeloid-derived suppressor cells (M-MDSCs) population in blood and spleen of mice. The in vitro assay demonstrated that Dioscin promoted M1 as well as inhibited M2 macrophages phenotype in LPS- or IL-4-induced bone marrow-derived macrophages (BMDMs) model. Based on the plasticity of MDSCs and its ability to differentiate into M1/M2 macrophages, we here found that Dioscin increased M1- and decreased M2-like phenotype during the process of MDSCs differentiation in vitro, suggesting Dioscin promoted MDSCs differentiate into M1 as well as inhibited its differentiation into M2 macrophages. Taken together, our study indicated that Dioscin had the inhibitory effect on the initial of tumorigenesis at early stage of CAC via the ant-inflammatory effect, which provided a natural active candidate for effective prevention of CAC.

High-performance carboxymethyl cellulose-based composite film tailored by versatile zeolitic imidazolate framework.

Robust biopolymer-based composite film with multifunctional performances significantly contributes to the packaging field. Herein, we proposed a sort of carboxymethyl cellulose (CMC) based composite film via incorporating versatile zeolitic imidazolate framework (ZIF) materials. Compared to pristine CMC film, the OTR, WVTR, and tensile strength of CMC/ZIF composite film with 1 wt ‰ Zn/Co-ZIF were improved from 64.89 cm3*µm/(m2*d*kPa), 1579.21 g/(m2*24h) and 16.9 MPa to 20.79 cm3*µm/(m2*d*kPa), 1209.58 g/(m2*24h) and 70.1 MPa, respectively. Notably, owing to the reduced band gap and intrinsic chemical and thermal stability of Zn/Co-ZIF, the fabricated Zn/Co-ZIF/CMC composite film presented well UV protection capability within the whole UV region and excellent UV-blocking durability after being exposed to UV-light at 365 nm for 12 h. In practice, the photocatalytic degradation of RhB solutions under UV light could be effectively suppressed when using Zn/Co-ZIF/CMC film as UV protection layer. Our findings proposed the potential application of these versatile ZIF materials as functional nanofiller within biopolymer substances for UV protection and transparent packaging area.

High-performance carboxymethyl cellulose-based hydrogel film for food packaging and preservation system.

Most traditional food packaging and preservation films suffer from limited stretchability and relatively simple functionality, which severely restricts their practical application. In this study, a highly stretchable and versatile sodium carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA)/poly(ethylene imine) (PEI)/tannic acid (TA) hydrogel film was elaborately designed and demonstrated as an efficient food packaging and preservation system. The dynamic reversible non-covalent within three-dimensional (3D) network structures served as sacrificial bonds to dissipate the loaded energy and endowed the hydrogel film with excellent elongation ~400 %, which is much larger than that of conventional food packaging films (<50 %). Furthermore, the optimized CMC/PVA/PEI/TA3 hydrogel film delivers versatile performances, including self-healing, whole UV-blocking (<400 nm), strong adhesive strength (234.08 KPa), antioxidation virtues, oxygen barrier (32.64 cm3*µm/(m2*d*KPa)) and water vapor barrier (642.92 g/(m2*24 h)). Notably, the shelf life of fresh strawberries, mangoes, and cherries was prolonged by at least one week under ambient conditions when the packaging box was covered by the fabricated CMC/PVA/PEI/TA3 film. Thus, our work not only provides a highly stretchable and versatile hydrogel film but also boosts the in-depth comprehension and rational design of robust food packaging and preservation films.

High-performance cellulose acetate-based gas barrier films via tailoring reduced graphene oxide nanosheets.

Improving the gas molecule barrier performance and structural stability of bio-plastic films dramatically contribute to packaging and protective fields. Herein, we proposed a novel nanocomposite film consisting of cellulose acetate (CA)/polyethyleneimine (PEI)/reduced graphene oxide (rGO)-NiCoFeOx) with high gas barrier property by applying "molecular glue" and "nano-patching" strategies. Systematical investigations demonstrated that the CA/rGO interfacial interaction was effectively enhanced due to the "molecular glue" role of PEI chains via physical/chemical bonds and the defective regions in rGO plane were nano-patched through hydrophilic interactions between edged oxygen-containing functional groups and ultrafine NiCoFeOx nanoparticles (~3 nm). As a result, the oxygen and moisture transmission rates of the prepared CA/PEI/rGO-NPs hybrid film were significantly reduced to 0.31 cm3 ∗ µm/(m2 ∗ d ∗ kPa) and 314.23 g/m2 ∗ 24 h, respectively, which were 99.60% and 54.69% lower than pristine CA films. Meanwhile, the tensile strength of hybrid film was increased from 25.90 MPa to 40.67 MPa. More importantly, the designed nanocomposite film possesses excellent structural stability without obvious GO layer shedding and hydrophobicity attenuation after persistent bending at least 100 times. The exceptional robust and high gas barrier film displays great promising application in food, agriculture, pharmaceuticals and electronic instruments packaging industry.

The m6A-related gene signature for predicting the prognosis of breast cancer.

N6-methyladenosine (m6A) modification has been shown to participate in tumorigenesis and metastasis of human cancers. The present study aimed to investigate the roles of m6A RNA methylation regulators in breast cancer. We used LASSO regression to identify m6A-related gene signature predicting breast cancer survival with the datasets downloaded from Gene Expression Omnibus and The Cancer Genome Atlas (TCGA). RNA-Seq data of 3409 breast cancer patients from GSE96058 and 1097 from TCGA were used in present study. A 10 m6A-related gene signature associated with prognosis was identified from 22 m6A RNA methylation regulators. The signature divided patients into low- and high-risk group. High-risk patients had a worse prognosis than the low-risk group. Further analyses indicated that IGF2BP1 may be a key m6A RNA methylation regulator in breast cancer. Survival analysis showed that IGF2BP1 is an independent prognostic factor of breast cancer, and higher expression level of IGF2BP1 is associated with shorter overall survival of breast cancer patients. In conclusion, we identified a 10 m6A-related gene signature associated with overall survival of breast cancer. IGF2BP1 may be a key m6A RNA methylation regulator in breast cancer.

The role of long non-coding RNAs in drug resistance of cancer.

Long non-coding RNAs (lncRNAs), a class of long RNAs, are longer than 200 nucleotides in length but lack protein-coding capacity. LncRNAs, as critical genomic regulators, are involved in genomic imprinting regulation, histone modification and gene expression regulation as well as tumor initiation and progression. However, it is also found that lncRNAs are associated with drug resistance in several types of cancer. Drug resistance is an important reason for clinical chemotherapy failure, and the molecular mechanism of tumor resistance is complex, which is a process of multi-cause, multi-gene and multi-signal transduction pathway interaction. Then comprehending the mechanisms of chemoresistance will help find ways to control the tumor progression effectively. Therefore, in this review, we will construct lncRNAs /drug resistance interaction network and shed light on the role of lncRNAs in drug resistance.

Identification and validation of prognostic signature for breast cancer based on genes potentially involved in autophagy.

We aimed to identify prognostic signature based on autophagy-related genes (ARGs) for breast cancer patients. The datasets of breast cancer were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Least absolute shrinkage and selection operator (LASSO) Cox regression was conducted to construct multiple-ARG risk signature. In total, 32 ARGs were identified as differentially expressed between tumors and adjacent normal tissues based on TCGA. Six ARGs (IFNG, TP63, PPP1R15A, PTK6, EIF4EBP1 and NKX2-3) with non-zero coefficient were selected from the 32 ARGs using LASSO regression. The 6-ARG signature divided patients into high-and low-risk group. Survival analysis indicated that low-risk group had longer survival time than high-risk group. We further validated the 6-ARG signature using dataset from GEO and found similar results. We analyzed the associations between ARGs and breast cancer survival in TCGA and nine GEO datasets, and obtained 170 ARGs with significant associations. EIF4EBP1, FOS and FAS were the top three ARGs with highest numbers of significant associations. EIF4EBP1 may be a key ARG which had a higher expression level in patients with more malignant molecular subtypes and higher grade breast cancer. In conclusion, our 6-ARG signature was of significance in predicting of overall survival of patients with breast cancer. EIF4EBP1 may be a key ARG associated with breast cancer survival.

Identification of circRNA-miRNA networks for exploring an underlying prognosis strategy for breast cancer.

Aim: Circular RNAs (circRNAs) still have many potential functions in the process of tumor development that are not completely understood. The study aims to explore novel circRNAs and their mechanisms of action in breast cancer (BCa). Materials & methods: A combination strategy of RNA-sequencing (RNA-seq) technique, quantitative real-time PCR and bioinformatic analysis was employed to identify the potential mechanisms involving differentially expressed circRNAs in the serum exosomes and tissues of BCa patients. Results: The expression levels of hsa-circRNA-0005795 and hsa-circRNA-0088088 were significantly different both in serum exosomes and tissues and might function as competing endogenous RNAs and play vital roles in BCa development. Conclusion: We constructed two circRNA-miRNA networks and provided new insight into the prognosis and therapy of BCa using circRNAs from serum exosomes.

Circular RNA circVAPA regulates breast cancer cell migration and invasion via sponging miR-130a-5p.

Aim: We aimed to explore the roles of circular RNA, circVAPA in regulating cell migration and invasion of breast cancer. Materials & methods: CircVAPA expression was detected in breast cancer tissues and cells. The role of circVAPA was evaluated by MTT assay, wound-healing and transwell assay. The relationship between circVAPA and miR-130a-5p and the location of circVAPA were explored. Results: We discovered that circVAPA was dysregulated in breast cancer tissues and cells. Ectopic circVAPA regulated breast cancer migration, invasion and proliferation. CircVAPA was mainly expressed in the cytoplasm and could act as a miRNA sponge for miR-130a-5p, but did not regulate its parental gene. Conclusion: CircVAPA may promote migration and invasion capacity of breast cancer via harboring miR-130a-5p.

Microenvironment-induced TIMP2 loss by cancer-secreted exosomal miR-4443 promotes liver metastasis of breast cancer.

We aimed to investigate the role of exosomal miR-4443 in metastasis of breast cancer (BCa). In vitro wound-healing assay and transwell invasion assay were used to investigate effect of miR-4443 on BCa cells. Animal experiments were performed to confirm its effects in vivo. miR-4443 promotes the metastasis of BCa cells through downregulating tissue inhibitors of metalloproteinase 2 (TIMP2) and upregulating matrix metalloproteinases (MMPs). Highly invasive BCa cells have a higher expression of miR-4443 in both cells and exosomes. The exosomes derived from highly invasive BCa cells mainly gather in the primary tumor and liver. In vivo, overexpression of miR-4443 in noninvasive BCa cells induces liver metastasis, accompanied with downregulated TIMP2, and upregulated MMP-2 in both the primary tumor and liver. When we armed MCF-10A exosomes with miR-4443 inhibitors to treat mice bearing high-miR-4443 tumors, exosomes accumulated in the primary tumor, and liver following the upregulation of TIMP2 and downregulation of MMP2, and the metastasis was inhibited. Highly invasive BCa cells destroy natural barriers against metastasis by delivering exosomal miR-4443 to stromal cells of the primary tumor and impairing TIMP2, consequently activating MMP; circulating exosomal miR-4443 might promote BCa cells lodging in future metastatic sites through the similar mechanisms.

Clinical and transcriptional signatures of human CD204 reveal an applicable marker for the protumor phenotype of tumor-associated macrophages in breast cancer.

BACKGROUND: Tumor-associated macrophages in human breast cancer are poorly understood. Specific tumor-associated macrophage-related molecular mechanisms among different intrinsic molecular subtypes remain unclear. Here, we have identified and explored the roles of the tumor-associated macrophages novel marker: CD204 in different subtypes of breast cancer. RESULTS: CD204 was upregulated in four subtypes of breast cancer, and this was associated with poor survival outcomes. CD204 could promote tumor cell proliferation, migration, and invasion and was involved in immune system-related pathways among all subtypes. Special pathways in each subtype were also found. High CD204 mRNA expressions were associated with high proportions of protumor immune cell populations, and most immunoinhibitors positive correlated with CD204 expression in all subtypes. CONCLUSIONS: These findings contribute to a better understanding and managing the protumor phenotype of tumor-associated macrophages in different subtypes of breast cancer. METHODS: The expression of CD204 and its clinical outcome were analyzed. The roles of CD204 in the regulation of tumor cell proliferation, migration, and invasion were studied. Potential pathways influenced by CD204 were displayed. Immune cell infiltration in different CD204 mRNA expression status and correlations between CD204 and immunoinhibitors were also analyzed.

Identification of internal control genes for circular RNAs.

OBJECTIVE: At present, no studies have established internal control genes for circular RNA (circRNA) analyses. We aimed to identify reference circRNAs for real-time quantitative PCR (RT-qPCR). RESULTS: After analyzing the RNA-seq data, we obtained 50 circRNAs that were expressed in all samples. We ranked these 50 circRNAs according to their stability and obtained the six most stable circRNAs. We further evaluated the stability of the six circRNAs and three linear control genes (i.e., GAPDH, ß-actin and 18S rRNA) in 22 cell lines. Our results indicated that hsa_circ_0000284 (circHIPK3) and hsa_circ_0000471 (circN4BP2L2) were the two most stable genes. After removing linear RNAs or including the cells treated with Adriamycin, NH4Cl and shikonin, the two most stable genes were hsa_circ_0000471 and hsa_circ_0000284. The amplification efficiency was 100% for hsa_circ_0000471 and 95% for hsa_circ_0000284. CONCLUSIONS: In conclusion, since the stability of circRNAs is higher than that of linear RNAs, hsa_circ_0000284 and hsa_circ_0000471 may be used as reference genes not only for circRNAs but also for other kinds of RNAs. The findings in the present study fill the gap of lacking reference genes in the detection of circRNAs.

The emerging role of circular RNAs in breast cancer.

Breast cancer (BCa) is one of the most frequently diagnosed cancers and leading cause of cancer deaths among females worldwide. Circular RNAs (circRNAs) are a new class of endogenous regulatory RNAs characterized by circular shape resulting from covalently closed continuous loops that are capable of regulating gene expression at transcription or post-transcription levels. With the unique structures, circRNAs are resistant to exonuclease RNase R and maintain stability more easily than linear RNAs. Recently, an increasing number of circRNAs are discovered and reported to show different expression in BCa and these dysregulated circRNAs were correlated with patients' clinical characteristics and grade in the progression of BCa. CircRNAs participate in the bioprocesses of carcinogenesis of BCa, including cell proliferation, apoptosis, cell cycle, tumorigenesis, vascularization, cell invasion, migration as well as metastasis. Here we concentrated on biogenesis and function of circRNAs, summarized their implications in BCa and discussed their potential as diagnostic and therapeutic targets for BCa.

Clinical and pathological significance of Homo sapiens ceramide synthase 2 (CerS-2) in diverse human cancers.

Homo sapiens ceramide synthase 2 (CerS-2) plays an important role in inhibiting invasion and metastasis of tumor cells and has been reported as a tumor metastasis suppressor gene in diverse cancers. Thus, low level of CerS-2 protein might suggest a bad prognosis and up-regulation of CerS-2 protein might act as a promising therapeutic strategy for malignant tumors. In this review, we discussed the expression, as well as the clinical and pathological significance of CerS-2 in diverse human cancers. The pathological processes and molecular pathways regulated by CerS-2 were also summarized.

Circular RNA expression in exosomes derived from breast cancer cells and patients.

AIM: We aimed to explore the roles of circular RNAs (circRNAs) in breast cancer (BCa). MATERIALS & METHODS: RNA was extracted from exosomes and BCa cells and analyzed using the RNA sequencing technique or microarray. RESULTS: Compared with controls, 1147 and 1195 circRNAs were dysregulated in exosomes from metastatic and localized BCa patients, respectively. A total of 480 dysregulated circRNAs were found in metastatic patients compared with localized patients, and these dysregulated circRNAs were enriched in eight pathways. Compared with MCF-7 cells and their exosomes, there were 5842 and 1137 dysregulated circRNAs in MDA-MB-231 cells and exosomes, respectively, and 5 circRNAs were confirmed using real-time quantitative PCR. CONCLUSION: We identified a number of dysregulated circRNAs in exosomes from BCa cells and patients.

Circular RNA circASS1 is downregulated in breast cancer cells MDA-MB-231 and suppressed invasion and migration.

AIM: The study aimed to investigate the role of circular RNA circASS1 in breast cancer cells. MATERIALS & METHODS: Circular RNAs microarray expression profile were analyzed in MCF-7, MDA-MB-231, and qRT-PCR and western blotting were used to quantify expression of circASS1 and its parental gene ASS1. Wound healing, migration and invasion assay were performed. Luciferase assay system was used to detect harbored miRNA. RESULTS: CircASS1 in MDA-MB-231 is downregulated comparing to MCF-7, and overexpression of circASS1 could suppress invasion and migration. While silence, it could promote invasion and migration. MiR-4443 functioning as a tumor promoter gene could be captured by circASS1. ASS1 is upregulated in loss-of-function experiments, while downregulated in gain-of-function experiments. CONCLUSION: CircASS1 suppresses invasion and migration capacity of breast cancer cells and harbored miR-4443.

Identification of genes associated with survival of breast cancer patients.

BACKGROUND: We aimed to investigate the potential of microRNA expression profiles to predict survival in breast cancer. METHODS: MicroRNA and mRNA expression data of breast cancer were downloaded from The Cancer Genome Atlas. LASSO regression was used to identify microRNAs signature predicting survival of breast cancer patients. Transfection experiment was conducted to explore the influence of microRNAs on their potential targets. RESULTS: We identified 56 differentially expressed microRNAs in breast cancer tissues compared to adjacent normal tissues. 10 microRNAs with non-zero coefficient were selected from the 56 microRNAs using LASSO Cox regression. After predicting the targets for the 10 microRNAs, we further obtained 155 targets that were associated with overall survival of breast cancer patients. Spearman's correlation analysis found that the expression of SCUBE2, SCRN3, YTHDF3, ITFG1, ITPRIPL2, and JAK1 was an inversely correlated with their microRNAs. Transfection experiment showed that YTHDF3 was down-regulated in cells transfected with miR-106b-5p mimics compared with those transfected with negative control of mimics (fold change 4.21; P < 0.01). CONCLUSIONS: In conclusion, we identified a 10-miRNA signature associated with prognosis of breast cancer patients. The expression of YTHDF3 was down-regulated by miR-106b-5p.

Exosome: a novel mediator in drug resistance of cancer cells.

Exosomes are small membrane vesicles with a diameter of 40-100 nm, which are released into the intracellular environment. Exosomes could influence the genetic and epigenetic changes of receptor cells by promoting the horizontal transfer of various proteins or RNAs, especially miRNAs. Moreover, exosomes also play an important role in tumor microenvironment. Exosomes could promote the short- and long-distance exchanges of genetic information by acting as mediators of cell-to-cell communication. In addition, exosomes participate in drug resistance of tumor cells by genetic exchange between cells. It is reported that exosomes could be absorbed by recipient cells and transmit chemoresistance from drug-resistant tumor cells to sensitive ones. Then understanding the mechanisms of chemotherapy failure and controlling tumor progression effectively will be a major challenge for us. Therefore, in this review, we will briefly reveal the role of exosomes in drug resistance.