The effects of computer-assisted cognitive rehabilitation on cognitive impairment after stroke: A systematic review and meta-analysis.

OBJECTIVES: To determine the effectiveness of computer-assisted cognitive rehabilitation in improving cognitive function in patients with post-stroke cognitive impairment. BACKGROUND: In recent years, computer-assisted cognitive rehabilitation has been accepted as a good substitute or supplement for traditional cognitive rehabilitation. Some clinical randomised controlled trials have been carried out, but no relevant systematic evaluations have been performed. Therefore, we conducted a systematic review of studies involving computer-assisted cognitive rehabilitation to provide evidence-based data for its promotion and application. METHODS: Nine databases (Cochrane Library, PubMed, Web of Science, Embase, OVID, Wanfang Data, CNKI, VIP and SinoMed databases) were systematically searched. Randomised controlled trials that assessed computer-assisted cognitive rehabilitation for patients with post-stroke cognitive impairment were included. Two reviewers appraised the risks of bias through the Cochrane Collaboration's tool and performed the meta-analysis, including the assessment of heterogeneity. We follow the PRISMA 2020 guidelines. RESULTS: Thirty-two studies comprising 1837 participants were included. Compared with conventional therapy alone, the addition of computer-assisted cognitive rehabilitation significantly improved the global cognition of patients, evaluated using the Montreal cognitive assessment, mini-mental state examination and Loewenstein occupational therapy cognitive assessment (p < .01 for all tests). The therapy also significantly improved activities of daily living, assessed using the Barthel index, modified Barthel index and functional independence measure (p < .05 for all tests). CONCLUSION: Computer-assisted cognitive rehabilitation significantly improved the cognitive function and activities of daily living of patients with post-stroke cognitive impairment. RELEVANCE TO CLINICAL PRACTICE: Computer-assisted cognitive rehabilitation can be a valuable technique for cognitive rehabilitation after stroke. It is advantageous for improving patient cognition and restoring the overall functional state of patients. Moreover, the research findings can provide suggestions and inspiration for researchers to implement the proposal, which is conducive to the design of more rigorous and high-quality randomised controlled trials.

The N-terminal polypeptide derived from vMIP-II exerts its antitumor activity in human breast cancer through CXCR4/miR-7-5p/Skp2 pathway.

Breast cancer is a malignant tumor with the highest incidence in women of the world. CXCR4 and Skp2 are highly expressed in breast cancer cells and CXCR4 was positively correlated with Skp2 by interference or overexpression. The microRNA array was used to detect the differentially expressed spectrum of micro RNAs in breast cancer cells the changes of miR-7-5p after CXCR4 inhibitor (NT21MP) treatment to block the CXCR4/SDF-1 pathway was founded. MiR-7-5p has been found to be correlated with Skp2 in various tumors in the literature, and Skp2 expression can be regulated by transfection with miR-7-5p mimics or inhibitors. The expression level of miR-7-5p was upregulated or downregulated after CXCR4 interference or overexpression. Combined with the correlation between CXCR4 and miR-7-5p in the chip results, CXCR4 may regulate Skp2 through miR-7-5p. Epithelial cells have the morphological characteristics of mesenchymal cells for some reason called epithelial-mesenchymal transformation (EMT). Transfection of miR-7-5p mimics into drug-resistant cells reduced Skp2 levels, decreased the expression of Vimentin, Snail, and slug, and increased the expression of E-cadherin. CXCR4 inhibitor (NT21MP) can reverse the EMT changes caused by miR-7-5p inhibitor. Similarly, in vivo results suggesting that CXCR4 inhibitors can reverse the EMT phenotype of drug-resistant breast cancer cells through the CXCR4/miR-7-5p/Skp2 pathway. In summary, the CXCR4/miR-7-5p/Skp2 signaling pathway plays an important role in the progression of breast cancer. This study provides a theoretical basis for the treatment of breast cancer by targeting the CXCR4 pathway.

Long noncoding RNA H19 acts as a miR-340-3p sponge to promote epithelial-mesenchymal transition by regulating YWHAZ expression in paclitaxel-resistant breast cancer cells.

Breast cancer (BC) is the leading cause of cancer-related death in women worldwide and one of the most prevalent malignancy. In recent years, increasing evidence had illuminated that long noncoding RNAs (lncRNAs) serve as critical factors in multiple tumor progression, including BC. Emerging references had indicated that the lncRNA H19 acts as significant roles in tumor progression and epithelial-mesenchymal transition (EMT). However, the underlying molecular mechanisms and biological roles of H19 in BC invasion, metastasis and EMT are still unclear. In this study, it was detected that the expression level of H19 was increased in BC paclitaxel-resistant (PR) cells subline (MCF-7/PR) in comparison with MCF-7 parental cells. In vitro, there were demonstrated that H19 overexpression promoted BC cells proliferation, metastasis, invasion and EMT procedures, and suppressed cells apoptosis. Whereas, H19 suppression resulted in the contrary biological effects. Besides, bioinformatics tools and dual-luciferase reporters assays indicated that miR-340-3p could act as a potential target gene of H19, the underlying mechanism studies proved that H19 could act as a competing endogenous RNA (ceRNA) via competitively binding miR-340-3p to promote BC cell proliferation, metastasis and EMT by regulating tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) and potentiate the Wnt/ß-catenin signaling in BC cells. In summary, our findings demonstrated that H19 could act as a ceRNA in BC progression, metastasis and EMT through modulating miR-340-3p/YWHAZ axis and activating the canonical Wnt/ß-catenin signaling pathway, indicating that H19 might act as an underlying therapeutic target and prognostic biomarker for BC therapy.

Long noncoding RNA AC073284.4 suppresses epithelial-mesenchymal transition by sponging miR-18b-5p in paclitaxel-resistant breast cancer cells.

Breast cancer (BC) is the most prevalent malignant cancer in the world, is the leading cause of cancer-related death female. Recently, there is accumulating evidence that long noncoding RNAs (lncRNAs) might as an important role in the progression of BC. (epithelial-mesenchymal transition (EMT) is considered to play a vital role in tumor cells migration and invasion. Nevertheless, the entire biological mechanisms and functions of lncRNAs in tumor migration, invasion, and EMT remain uncertain. In the present research, we observed that the expression of lncRNA AC073284.4 was downregulated in BC paclitaxel-resistant (PR) cells (MCF-7/PR) and tissues. Bioinformatics analysis predicted that miR-18b-5p was a direct target of AC073284.4, which has been validated by dual-luciferase reporter gene assay. We further proved that AC073284.4 could directly bind to miR-18b-5p and relieve the suppression for dedicator of cytokinesis protein 4 (DOCK4). Furthermore, the underlying functional experiments demonstrated that AC073284.4 might sponge miR-18b-5p to attenuate the invasion, metastasis, and EMT of BC cell through upregulating DOCK4 expression. In summary, AC073284.4 might serve as a competing endogenous RNA (ceRNA) in BC progression via modulating miR-18b-5p/DOCK4 axis, which weakens EMT and migration of BC. These results suggesting that AC073284.4 might function as a potential novel diagnostic biomarker in the progression of BC.

Curcumin-Loaded Solid Lipid Nanoparticles Enhanced Anticancer Efficiency in Breast Cancer.

Curcumin (Cur) has been widely used in medicine, due to its antibacterial, anti-inflammatory, antioxidant, and antitumor effects. However, its clinic application is limited by its instability and poor solubility. In the present wok, curcumin was loaded into solid lipid nanoparticles (SLNs), in order to improve the therapeutic efficacy for breast cancer. The results measured using transmission electron microscopy (TEM) indicated that Cur-SLNs have a well-defined spherical shape; the size was about 40 nm with a negative surface charge. The drug loading and encapsulation efficiency in SLNs reached 23.38% and 72.47%, respectively. The Cur-SLNs showed a stronger cytotoxicity against SKBR3 cells. In vitro cellular uptake study demonstrated a high uptake efficiency of the Cur-SLNs by SKBR3 cells. Moreover, Cur-SLNs induced higher apoptosis in SKBR3 cells, compared to cells treated by free drug. In addition, Western blot analysis revealed that Cur-SLNs could promote the ratio of Bax/Bcl-2, but decreased the expression of cyclin D1 and CDK4. These results suggested that Cur-SLNs could be a potential useful chemotherapeutic formulation for breast cancer therapy.

Anticancer Effects of Resveratrol-Loaded Solid Lipid Nanoparticles on Human Breast Cancer Cells.

In this study, resveratrol-loaded solid lipid nanoparticles (Res-SLNs) were successfully designed to treat MDA-MB-231 cells. The Res-SLNs were prepared using emulsification and low-temperature solidification method. The Res-SLNs were spherical, with small size, negative charge, and narrow size distribution. Compared with free resveratrol, the Res-SLNs displayed a superior ability in inhibiting the proliferation of MDA-MB-231 cells. In addition, Res-SLNs exhibited much stronger inhibitory effects on the invasion and migration of MDA-MB-231 cells. Western blot analysis revealed that Res-SLNs could promote the ratio of Bax/Bcl-2 but decreased the expression of cyclinD1 and c-Myc. These results indicate that the Res-SLN may have great potential for breast cancer treatment.

[Effects of lncRNA RP11-770J1.3 and TMEM25 expression on paclitaxel resistance in human breast cancer cells].

OBJECTIVE: To investigate the effects of long non-coding RNA(lncRNA) RP11-770J1.3 and transmembrane protein 25 (TMEM25) on paclitaxel resistance in human breast cancer MCF-7/PR cell line. METHODS: The expression of lncRNA RP11-770J1.3 and TMEM25 in human breast cancer MCF-7(paclitaxel sensitive) and MCF-7/PR(paclitaxel resistant) cells were detected by quantitative RT-PCR. The synthetic interfering fragments of lncRNA RP11-770J1.3 and TMEM25 were transfected into MCF-7/PR cells. Sulforhodamine B assay was used to detect the sensitivity of MCF-7/PR cells to paclitaxel after interference of lncRNA RP11-770J1.3 and TMEM25. The expression of multidrug-resistance genes and proteins were detected by qRT-PCR and Western blot, respectively. RESULTS: lncRNA RP11-770J1.3 and TMEM25 were highly expressed in MCF-7/PR cells, and were significantly down-regulated after transfection of synthetic interfering fragments. Down-regulation of lncRNA RP11-770J1.3 and TMEM25 enhanced the sensitivity of MCF-7/PR cells to paclitaxel, and inhibited the expression of MRP, BCRP and MDR1/P-gp (all P<0.05). Such effects were more significant when lncRNA RP11-770J1.3 and TMEM25 were both down-regulated (all P<0.05). CONCLUSIONS: lncRNA RP11-770J1.3 and TMEM25 are highly expressed in MCF-7/PR cells, and the down-regulation of lncRNA RP11-770J1.3 and TMEM25 can enhance paclitaxel sensitivity in MCF-7/PR cells.

[CXC chemokine receptor 4 regulates breast cancer cell cycle through S phase kinase associated protein 2].

OBJECTIVE: To investigate the effect of CXC chemokine receptor 4 (CXCR4) on cell cycle of breast cancer and its molecular mechanisms. METHODS: The expression of CXCR4 and S phase kinase associated protein 2 (Skp2) was detected by real-time fluorescence quantitative PCR (fqRT-PCR) and Western blot in breast cancer cells. The expression of signal proteins and the downstream genes of Skp2 was detected by Western blot. The effect of CXCR4, PI3K/Akt pathway inhibitor LY294002 and ERK pathway inhibitor U0126 on cell cycle of breast cancer was detected by propidium iodide staining. RESULTS: Skp2 was significantly down-regulated in CXCR4-downregulated cells and up-regulated in CXCR4-upregulated cells. CXCR4 also regulated the expression of Skp2 and other downstream genes by signaling protein. The proportion of cells in G0/G1 phase increased and that in S phase declined in CXCR4-downregulated cell, and the effect was more significant when combined with the use of LY294002 or U0126. CONCLUSIONS: CXCR4 can affect cell cycle and inhibit the proliferation of breast cancer cells by regulating Skp2 gene expression through PI3K/Akt and ERK signaling pathway.

[Effects of miRNA-21 on paclitaxel-resistance in human breast cancer cells].

OBJECTIVE: To investigate the effects of miR-21 on paclitaxel-resistance in human breast cancer MCF-7/PR and SKBR-3/PR cells. METHODS: Paclitaxel-resistant human breast cancer cell lines MCF-7/PR and SKBR-3/PR were established by stepwise selection in increasing concentration of paclitaxel. Cellular morphology, mRNA and protein level of MDR1, BCRP and MRP1 in MCF-7/PR and SKBR-3/PR cells were determined. The expression of Bax, Bcl-2 and miR-21 in parental and paclitaxel-resistant cells was detected by RT-PCR and Western blotting. The synthetic miR-21 inhibitor or miR-21 mimic were transfected into MCF-7/PR, SKBR-3/PR and MCF-7, SKBR-3 cells with Lipofectamine 2000. The miR-21 levels were determined by RT-PCR, and P-gp, Bcl-2 and Bax protein levels were examined by Western blotting. MTT assay was used to measure the cell viability, and flow cytometry was performed to analyze the cell cycle and apoptosis. RESULTS: The levels of MDR1, BCRP, MRP1, Bcl-2/Bax and miR-21 in MCF-7/PR and SKBR-3/PR cells were significantly higher than those in MCF-7 and SKBR-3 cells. The protein levels of P-gp, Bcl-2 were up-regulated, and Bax was down-regulated compared with parental cells. MiR-21 was significantly down-regulated after miR-21 inhibitor was transfected; and the levels of MDR1, BCRP, MRP1 and Bcl-2/Bax (P <0.05) were also down-regulated. MiR-21 inhibitors significantly suppressed G0/G1 transition of the cell cycle, and induced cell apoptosis in MCF-7/PR and SKBR-3/PR cells. MTT results showed that miR-21 inhibitors induced sensitivity of MCF-7/PR and SKBR-3/PR cells to paclitaxel. And miR-21 mimic can increase the expression of MDR1, Bcl-2/Bax and change cell morphology from parental cells to resistant cells. RESULTS: The established MCF-7/PR and SKBR-3/PR breast cancer cells show typical multidrug resistance characteristics, which can be used as the model for drug resistance study. Down-regulated miR-21 expression in MCF-7/PR and SKBR-3/PR breast cancer cells can enhance cell sensitivity to paclitaxel.

Layered Double Hydroxide-Loaded miR-30a for the Treatment of Breast Cancer In Vitro and In Vivo.

MicroRNAs (miRNAs) play an essential role in cancer therapy, but the disadvantages of its poor inherent stability, rapid clearance, and low delivery efficiency affect the therapeutic efficiency. Loading miRNAs by nanoformulations can improve their bioavailability and enhance therapeutic efficiency, which is an effective miRNA delivery strategy. In this study, we synthesized layered double hydroxides (LDH), which are widely used as carriers of drugs or genes due to the characteristics of good biocompatibility, high loading capacity, and pH sensitivity. We loaded the suppressor oncogene miR-30a on LDH nanomaterials (LDH@miR-30a) and determined the mass ratio of miRNA binding to LDH by agarose gel electrophoresis. LDH@miR-30a was able to escape the lysosomal pathway and was successfully phagocytosed by breast cancer SKBR3 cells and remained detectable in the cells after 24 h of co-incubation. In vitro experiments showed that LDH@miR-30a-treated SKBR3 cells showed decreased proliferation and cell cycle arrest in the G0/G1 phase and LDH@miR-30a was able to regulate the epithelial-mesenchymal transition (EMT) process and inhibit cell migration and invasion by targeting SNAI1. Meanwhile, in vivo experiments showed that nude mice treated with LDH@miR-30a showed a significant reduction in their solid tumors and no significant impairment of vital organs was observed. In conclusion, LDH@miR-30a is an effective drug delivery system for the treatment of breast cancer.

Layered Double Hydroxides-Loaded Sorafenib Inhibit Hepatic Stellate Cells Proliferation and Activation In Vitro and Reduce Fibrosis In Vivo.

A core feature of liver fibrosis is the activation of hepatic stellate cells (HSCs), which are transformed into myofibroblasts and lead to the accumulation of extracellular matrix (ECM) proteins. In this study, we combined in vitro cellular efficacy with in vivo antifibrosis performance to evaluate the outcome of sorafenib (SRF) loaded layered double hydroxide (LDH) nanocomposite (LDH-SRF) on HSCs. The cellular uptake test has revealed that sorafenib encapsulated LDH nanoparticles were efficiently internalized by the HSC-T6 cells, synergistically inducing apoptosis of hepatic stellate cells. Moreover, the apoptosis rate and the migration inhibition rate induced by LDHs-SRF were 2.5 and 1.7 times that of SRF. Western Blot showed that the TGF-ß1/Smad/EMT and AKT signaling pathway was significantly inhibited in HSC-T6 cells treated with LDHs-SRF. For the in vivo experiment, LDHs-SRF were administered to rat models of CCl4-induced liver fibrosis. H&E, masson and sirius red staining showed that LDHs-SRF could significantly reduce inflammatory infiltrate and collagen fiber deposition and immunohistochemical results found that LDHs-SRF treatment significantly inhibited the protein expressions of α-SMA in the liver, these results suggesting that LDHs-SRF exhibited better anti-fibrotic effect than SRF alone and significantly inhibited the proliferation and activation of rat hepatic stellate cells and collagen fiber synthesis.

MiR-155-3p acts as a tumor suppressor and reverses paclitaxel resistance via negative regulation of MYD88 in human breast cancer.

MiR-155-3p, which is derived from the same pre-miRNA as miR-155-5p, the latter has been reported to be dysregulated in multiple tumor tissues and associated with clinicopathologic markers, tumor subtypes, and poor survival rates. However, the biological effects of miR-155-3p are rarely explored. In this study, we find that miR-155-3p was down-regulated in breast cancer and MYD88 was validated as the target for miR-155-3p. Moreover, miR-155-3p showed a negative effect on apoptosis, invasion and metastasis, reverses paclitaxel resistance by suppression of the corresponding target gene MYD88 in vitro and in vivo experiments. Taking together, our studies suggest that miR-155-3p, which serve as a negative regulatory mechanism for breast cancer development. The mechanism further complicates the regulatory network in human breast cancer.

[Quality of methodology and reporting of Meta-analyses on acupuncture treating ischemic stroke in China].

OBJECTIVE: To evaluate the quality of methodology and reporting of Meta-analyses on acupuncture treating ischemic stroke in China. METHODS: The domestic literature of systematic reviews (SRs) on acupuncture treating ischemic stroke was retrieved from CBM, VIP, CNKI and WANFANG databases. The quality of methodology and reporting was measured by A Measurement Tool to Assess Systematic Reviews (AMSTAR) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). RESULTS: Seven studies involving 6 papers in Chinese and 1 paper in English were chosen from 402 papers. The deficiencies of methodology mainly contained incomplete retrieval strategy, less attention to the publication bias and the heterogeneity, etc. The shortages of reporting was on retrieval strategy reporting, the studies features and the risk of bias reporting and evidence strength level reporting, etc. CONCLUSION: At present the quality of methodology and reporting of SRs on acupuncture treating ischemic stroke in China has flaws, which needs improvement.

NT21MP negatively regulates paclitaxel-resistant cells by targeting miR­155­3p and miR­155-5p via the CXCR4 pathway in breast cancer.

Evidence has shown that microRNAs (miRNAs) are vital in cell growth, migration, and invasion by inhibiting their target genes. A previous study demonstrated that miRNA (miR)-155­3p and miR­155-5p exerted opposite effects on cell proliferation, apoptosis, migration and invasion in breast cancer cell lines. An miRNA microarray was used to show that miR­155­3p was downregulated whereas miR­155-5p was upregulated in paclitaxel-resistant (PR) cells compared with parental breast cancer cells. However, the role of miR­155 in breast cancer cell invasion and metastasis remains to be elucidated. A 21-residue peptide derived from the viral macrophage inflammatory protein II (NT21MP), competes with the ligand of CXC chemokine receptor 4 (CXCR4) and its ligand stromal cell-derived factor-1α, inducing cell apoptosis in breast cancer. The present study aimed to identify the underlying mechanism of action of miR­155­3p/5p and NT21MP in PR breast cancer cells. Quantitative polymerase chain reaction, western blotting, wound-healing, cell cycle and apoptosis assays, and Cell Counting kit-8 assay were used to achieve this goal. The combined overexpression of miR­155­3p with NT21MP decreased the migration and invasion ability and increased the number of apoptotic and arrested cells in the G0/G1 phase transition in vitro. The knockdown of miR­155-5p combined with NT21MP had a similar effect on PR breast cancer cells. Furthermore, the ectopic expression of their target gene myeloid differentiation primary response gene 88 (MYD88) or tumor protein 53-induced nuclear protein 1 (TP53INP1) combined with NT21MP enhanced the sensitivity of the breast cancer cells to paclitaxel. Taken together, these findings suggested that miR­155­3p/5p and their target genes MYD88 and TP53INP1 may serve as novel biomarkers for NT21MP therapy through the CXCR4 pathway for improving sensitivity to paclitaxel in breast cancer.

The N-terminal polypeptide derived from vMIP-II exerts its anti-tumor activity in human breast cancer by regulating lncRNA SPRY4-IT1.

Accumulating evidence demonstrates that long non-coding RNA (lncRNA) sprouty4-intron transcript 1 (lncRNA SPRY4-IT1) plays a vital role in the development of breast cancer. However, the underlying mechanism has not been eventually illuminated. We aimed to explore the biological activity of lncRNA SPRY4-IT1 in breast cancer cells and whether N-terminal polypeptide derived from viral macrophage inflammatory protein II (NT21MP) could exert its anti-tumor effect by regulating lncRNA SPRY4-IT1 and its target gene SKA2 Real-time RT-PCR, Western blotting, wound healing, and invasion assays were used to achieve this goal. We found that lncRNA SPRY4-IT1 was highly expressed in breast cancer cells. Moreover, NT21MP markedly inhibited biological effects of breast cancer cells by regulating lncRNA SPRY4-IT1, which was partially achieved through SKA2. Our findings suggested that lncRNA SPRY4-IT1 could serve as a novel biomarker by NT21MP for breast cancer.

[Low expression of lncRNA-GAS5 promotes epithelial-mesenchymal transition of breast cancer cells in vitro].

OBJECTIVE: To investigate the role of long non-coding RNA growth arrest-specific transcript 5 (lncRNA-GAS5) in breast cancer progression and epithelial-mesenchymal transition (EMT) of the cancer cells. METHODS: Real-time quantitative PCR (qRT-PCR) was used to detect the expression of lncRNA-GAS5 in 37 pairs of breast cancer and adjacent non-tumor tissues and in parental MCF-7 cells and paclitaxel-resistant MCF-7 (MCF-7/PR) cells, and the correlation of lncRNA-GAS5 expression with the clinical stage and lymph node metastasis of breast cancer was investigated. The expressions of the genes related with cell cycle and EMT at both the mRNA and protein levels were detected using qRT-PCR, Western blotting and immunohistochemistry. The changes in the biological behaviors and morphology of breast cancer cells with either lncRNA-GAS5 knockdown or overexpression were observed. Nude mouse models were established bearing breast cancer xenografts derived from MCF-7/PR cells or MCF-7/PR cells over-expressing lncRNA-GAS5, and the inhibitory effect of paclitaxel on tumor growth was evaluated. RESULTS: The transcriptional levels of lncRNA-GAS5 were significantly lower in breast cancer tissues than in the adjacent non-tumor tissues (P<0.05), and decreased lncRNA-GAS5 expression was significantly correlated with TNM stage and lymph node metastasis of breast cancer (P<0.05). lncRNA-GAS5 expression was also significantly lowered in paclitaxel-resistant breast cancer cells and showed a positive correlation with P21 expression and a negative correlation with CDK6. MCF-7 cells during EMT presented with a lowered expression of lncRNA-GAS5, whereas lncRNA-GAS5 over-expression strongly suppressed MCF-7/PR cell migration and invasion, and increased the susceptibility of the cells to paclitaxel. In the tumor-bearing nude mouse models, lncRNA-GAS5 overexpression in the tumor cells obviously enhanced the inhibitory effect of paclitaxel on tumor growth and lung metastasis by reversing the EMT marker proteins. CONCLUSION: A decreased expression of lncRNA-GAS5 promotes lung metastasis of breast cancer by inducing EMT, suggesting the potential of lncRNA-GAS5 as a therapeutic target in breast cancer.

N-peptide of vMIP-â ¡ reverses paclitaxel-resistance by regulating miRNA-335 in breast cancer.

Acquisition of resistance to paclitaxel is one of the most important problems in treatment of breast cancer patients, but the molecular mechanisms underlying sensitivity to paclitaxel remains elusive. Emerging evidence has demonstrated that microRNAs (miRNAs) play important roles in regulation of cell growth, migration and invasion through inhibiting the expression of its target genes. In our previous studies, we have shown that microRNA-335 (miR­335) decreased obviously between paclitaxel-resistant (PR) and parental breast cancer cells through miRNA microarray. However, the roles of miR­335 in breast cancer progression and metastasis are still largely unknown. NT21MP was designed and synthesized as an antagonist with CXCR4 to inhibit cellular proliferation and induce apoptosis. Therefore, the aim of this study was to explore the underlying mechanism of miR­335 and NT21MP in reverse PR in breast cancer cells. In this study, we found that miR­335 expression is significantly lower in PR MCF­7 and SKBR-3 cells (MCF­7/PR and SKBR-3/PR) compared with their parental MCF­7 and SKBR-3 cells. Functional experiments showed that overexpression of miR­335 and NT21MP increased the number of apoptosis cells, arrested cells in G0/G1 phase transition, and suppressed cell migration and invasion in vitro. Dual luciferase assays revealed that SETD8 is a direct target gene of miR­335. Furthermore, miR­335 markedly inhibited expression of SETD8 via Wnt/ß­catenin signaling and subsequently inhibited the expression of its downstream genes cyclin D1, and c­Myc. Additionally, ectopic expression of miR­335 or depletion of its target gene SETD8 could enhance the sensitivity of PR cells to paclitaxel. Taken together, these date elucidated that NT21MP and miR­335 mediated PR of breast cancer cells partly through regulation of Wnt/ß­catenin signaling pathway. Activation of miR­335 or inactivation of SETD8 could be a novel approach for the treatment of breast cancer.

Involvement of miR-451 in resistance to paclitaxel by regulating YWHAZ in breast cancer.

MicroRNAs (miRNAs) have been identified as major post-transcriptional regulators of the initiation and progression of human cancers, including breast cancer. However, the detail role of miR-451 has not been fully elucidated in breast cancer. In this study, we aimed to investigate the biological role and molecular mechanisms of miR-451 in drug resistance in breast cancer cell lines and in xenograft model. We show that miR-451 is decreased in human breast cancer specimens and in paclitaxel-resistant (PR) cells. Ectopic expression of miR-451 could inhibit the cell migration and invasion, promoted apoptosis, induced cell-cycle arrest Furthermore, tyrosine3-monooxygenase/tryptophan5-monooxygenase activation protein zeta (YWHAZ) was identified as a direct target of miR-451. Remarkably, the expression of YWHAZ is inversely correlated with the level of miR-451 in human breast cancer samples. Co-treatment with miR-451 mimics and YWHAZ-siRNA significantly enhanced YWHAZ knockdown in both SKBR3/PR and MCF-7/PR cells Moreover, miR-451 markedly inhibited expression of ß-catenin via YWHAZ and subsequently inhibited downstream gene cyclin D1, c-Myc expression. The results of xenograft model in vivo showed that intratumor injection of miR-451 agomir induced a tumor-suppressive effect in SKBR3/PR drug-resistant xenograft model. Taken together, our findings suggested that miR-451 might be considered as important and potential target in paclitaxel-resistant breast cancer treatment.

N-terminal polypeptide derived from vMIP-II exerts its antitumor activity by inhibiting the CXCR4 pathway in human glioma.

Emerging evidence demonstrates that the stromal derived factor-1 (SDF-1α)/CXCR4 axis is associated with tumor aggressiveness and metastasis, including glioma, the most common brain cancer. In the present study, we demonstrated that a novel designed peptide NT21MP of viral macrophage inflammatory protein II, targeting CXCR4 inhibits SDF-1α-induced activation in glioma. The effects of NT21MP on CXCR4 expression, cell survival and migration were assessed on the human glioma cell line U251 and SHG-44 exposed to SDF-1α, by western blotting, MTT assay, flow cytometry and transwell migration assay. Our results illustrated that NT21MP inhibited SDF-1α induced proliferation, migration and invasion by upregulated pro-apoptotic genes (Bak1 and caspase-3) and downregulated Bcl-2/Bax as well as cell cycle regulators (cyclin D1 and CDK4) to arrest cell cycle in G0/G1 phase and promote apoptosis. By RT-qPCR and immunofluorescence we found that CXCR4 was highly expressed in SHG-44 cells. Our results from wound healing and transwell invasion assays indicated silencing of CXCR4 significantly inhibited the SDF-1α­induced migration and invasion; similarly, flow cytometry showed that treatment with si-CXCR4 affected cell cycle and induced cell apoptosis in SHG-44. However, these effects were significantly weakened by NT21MP. In conclusion, the present study indicates that NT21MP plays a regulatory role in the SDF-1α/CXCR4 axis and further manages the invasion, migration, apoptosis and cell cycle of glioma cells. Thus, NT21MP might represent a novel therapeutic approach against glioma.

The N-terminal polypeptide derived from viral macrophage inflammatory protein II reverses breast cancer epithelial-to-mesenchymal transition via a PDGFRα-dependent mechanism.

NT21MP, a 21-residue peptide derived from the viral macrophage inflammatory protein II, competed effectively with the natural ligand of CXC chemokine receptor 4 (CXCR4), stromal cell-derived factor 1-alpha, to induce apoptosis and inhibit growth in breast cancer. Its role in tumor epithelial-to-mesenchymal transition (EMT) regulation remains unknown. In this study, we evaluated the reversal of EMT upon NT21MP treatment and examined its role in the inhibition of EMT in breast cancer. The parental cells of breast cancer (SKBR-3 and MCF-7) and paclitaxel-resistant (SKBR-3 PR and MCF-7 PR) cells were studied in vitro and in combined immunodeficient mice. The mice injected with SKBR-3 PR cells were treated with NT21MP through the tail vein or intraperitoneally with paclitaxel or saline. Sections from tumors were evaluated for tumor weight and EMT markers based on Western blot. In vitro, the effects of NT21MP, CXCR4 and PDGFRα on tumor EMT were assessed by relative quantitative real-time reverse transcription-polymerase chain reaction, western blot and biological activity in breast cancer cell lines expressing high or low levels of CXCR4. Our results illustrated that NT21MP could reverse the phenotype of EMT in paclitaxel-resistant cells. Furthermore, we found that NT21MP governed PR-mediated EMT partly due to controlling platelet-derived growth factors A and B (PDGFA and PDGFB) and their receptor (PDGFRα). More importantly, NT21MP down-regulated AKT and ERK1/2 activity, which were activated by PDGFRα, and eventually reversed the EMT. Together, these results indicated that CXCR4 overexpression drives acquired paclitaxel resistance, partly by activating the PDGFA and PDGFB/PDGFRα autocrine signaling loops that activate AKT and ERK1/2. Inhibition of the oncogenic EMT process by targeting CXCR4/PDGFRα-mediated pathways using NT21MP may provide a novel therapeutic approach towards breast cancer.