Long non-coding RNA SNHG22 facilitates the malignant phenotypes in triple-negative breast cancer via sponging miR-324-3p and upregulating SUDS3.

BACKGROUND: Increasing evidence has indicated the important role of long non-coding RNAs (lncRNAs) in regulating the development and progression of cancers, including triple-negative breast cancer (TNBC). Small nucleolar RNA host gene 22 (SNHG22) is a novel lncRNA that has been identified as tumor-contributor in ovarian carcinoma. However, its function has not been explored in TNBC. METHODS: qRT-PCR was used to identify gene expression at mRNA level while western blot was utilized to analyze the protein level. Functional assays were implemented to identify changes on the proliferation, apoptosis and motility of TNBC cells under different conditions. Additionally, mechanistic assays, such as RIP assay, RNA pull down assay and luciferase reporter assay, were applied to assess relationships between molecules. RESULTS: SNHG22 represented a high expression level in TNBC tissues and cells. Besides, SNHG22 silencing restrained the proliferation, migration and invasion of TNBC cells. Furthermore, miR-324-3p that was lowly expressed in TNBC cells was conformed to be sponged by SNHG22. Moreover, upregulated miR-324-3p inhibited cell proliferation and motility in TNBC. Subsequently, we identified that SUDS3, a tumor-facilitator with elevated expression in TNBC, was the downstream target of SNHG22/miR-324-3p axis. Of note, miR-324-3p repression or SUDS3 overexpression could rescue the anti-tumor effect of SNHG22 silencing on the malignant phenotypes of TNBC cells. CONCLUSION: LncRNA SNHG22 facilitated cell growth and motility in TNBC via sponging miR-324-3p and upregulating SUDS3, highlighting a new promising road for TNBC treatment development.

Correlation of radiotherapy with prognosis of elderly patients with hormone receptor-positive breast cancer according to immunohistochemical subtyping.

OBJECTIVE: The present study examined the effect of radiotherapy on recurrence and survival in elderly patients with hormone receptor-positive early breast cancer. METHODS: A retrospective analysis of 327 patients aged ≥65 years, with stage I-II, hormone receptor-positive breast cancer who underwent breast-conserving surgery and received endocrine therapy (ET) or radiotherapy plus endocrine therapy (ET+RT) was performed. Both groups were divided into luminal A type and luminal B type subgroups. Evaluation criteria were 5-year disease-free survival (DFS), local relapse rate (LRR), overall survival (OS), and distant metastasis rate (DMR). RESULTS: There were significant differences in 5-year DFS [hazard ratio (HR)=1.59, 95% confidence interval (95% CI), 1.15-2.19; P=0.005] and LRR (HR=3.33, 95% CI, 1.51-7.34; P=0.003), whereas there were no significant differences in OS and DMR between ET group and ET+RT group. In luminal A type, there was no significant difference in 5-year DFS, LRR, OS and DMR between ET group and ET+RT group. In luminal B type, there were statistically significant differences in 5-year DFS (HR=2.19, 95% CI, 1.37-3.49; P=0.001), LRR (HR=5.45, 95% CI, 1.65-17.98; P=0.005), and OS (HR=1.75, 95% CI, 1.01-3.05; P=0.048) between ET group and ET+RT group. In the ET group, there were significant differences between luminal A type and luminal B type in 5-year DFS (HR=1.84, 95% CI, 1.23-2.75; P=0.003) and OS (HR=1.76, 95% CI, 1.07-2.91; P=0.026). CONCLUSIONS: After breast-conserving surgery, radiotherapy can reduce the LRR and improve the DFS and OS of luminal B type elderly patients, whereas luminal A type elderly patients do not benefit from radiotherapy. Without radiotherapy, luminal A type patients have better DFS and OS than luminal B type patients.

Beam shaping system based on a prism array for improving the throughput of a dispersive spectrometer.

A beam shaping system (BSS) for improving the throughput of a dispersive spectrometer is presented by employing two anamorphic lenses and a prism array to segment the beam. The BSS was designed based on the inverse method of beam shaping for laser diode bars and the means of an optical slicer. In an experiment, a BSS was set up so that the incident light of a neon lamp with a circular spot from an input fiber was transformed into an elliptical spot coupled into a slit of a spectrometer without a change of divergence. Spectral measurement results demonstrate that the throughput of the dispersive spectrometer was doubled without loss of spectral resolution. The BSS can be combined with the existing dispersive spectrometer to improve the luminous flux and signal-to-noise ratio.

MicroRNA-566 activates EGFR signaling and its inhibition sensitizes glioblastoma cells to nimotuzumab.

BACKGROUND: Epidermal growth factor receptor (EGFR) is amplified in 40% of human glioblastomas. However, most glioblastoma patients respond poorly to anti-EGFR therapy. MicroRNAs can function as either oncogenes or tumor suppressor genes, and have been shown to play an important role in cancer cell proliferation, invasion and apoptosis. Whether microRNAs can impact the therapeutic effects of EGFR inhibitors in glioblastoma is unknown. METHODS: miR-566 expression levels were detected in glioma cell lines, using real-time quantitative RT-PCR (qRT-PCR). Luciferase reporter assays and Western blots were used to validate VHL as a direct target gene of miR-566. Cell proliferation, invasion, cell cycle distribution and apoptosis were also examined to confirm whether miR-566 inhibition could sensitize anti-EGFR therapy. RESULTS: In this study, we demonstrated that miR-566 is up-regulated in human glioma cell lines and inhibition of miR-566 decreased the activity of the EGFR pathway. Lentiviral mediated inhibition of miR-566 in glioblastoma cell lines significantly inhibited cell proliferation and invasion and led to cell cycle arrest in the G0/G1 phase. In addition, we identified von Hippel-Lindau (VHL) as a novel functional target of miR-566. VHL regulates the formation of the ß-catenin/hypoxia-inducible factors-1α complex under miR-566 regulation. CONCLUSIONS: miR-566 activated EGFR signaling and its inhibition sensitized glioblastoma cells to anti-EGFR therapy.

Dispersive element based on grating and tunable Fabry-Perot filter in miniature spectrometer.

We present a new design for the integration of a tunable Fabry-Perot (FP) filter and the grating etched on top of the cavity (IGFP) in the miniature spectrometer. It is based on the predispersion of the grating with the capacity of spatial separation of the spectral component and filter effect of the tunable FP filter. The free spectral range (FSR) of the IGFP is determined by the FSR of the grating, and its resolution depends on the filtering capacity of the FP filter. In the experiment, the high-resolution and wavelength scanning process of the IGFP were demonstrated with a narrowband and broadband light source, respectively. The results of the sub-nanometer resolution agree well with those from a commercial optical spectrum analyzer. Further, the IGFP provides an effective approach to solve the problem of the decrease of spectral resolution in the miniaturization process.

Efficacy and prognosis of HER2-Low and HER2-Zero in triple-negative breast cancer after neoadjuvant chemotherapy.

Mounting evidence showed that HER2-Low breast cancer patients could benefit from the novel anti-HER2 antibody-drug conjugates (ADCs) treatment, which pointed the way towards better therapy for HER2-Low patients. The purpose of this study was to describe the clinicopathological features, along with chemotherapeutic effects and survival outcomes of HER2-Low and HER2-Zero in TNBC who received neoadjuvant chemotherapy (NACT). We retrospectively evaluated 638 triple-negative breast cancer patients who were treated with neoadjuvant chemotherapy between August 2014 and August 2022. Pathologic complete response (pCR) and survival outcomes were analyzed in HER2-Low cohort, HER2-Zero cohort and the overall patients, respectively. In the entire cohort, 342 (53.6%) patients were HER2-Low and 296 (46.4%) patients were HER2-Zero. No significant difference was found between HER2-Low and HER2-Zero patients based on all the clinical-pathological characteristics. 143 cases (22.4%) achieved pCR after NACT in the overall TNBC patients. The pCR rate of the HER2-Low patients and the HER2-Zero patients was 21.3% and 23.6%, respectively, exhibiting no statistical difference (p = 0.487). The survival of pCR group after NACT significantly improved compared to non-pCR group either in HER2-Low patients or in HER2-Zero patients. Although we found that patients with HER2-Low had longer DFS than patients with HER2-Zero, there was no considerable difference (p = 0.068). However, HER2-Low patients had a dramatically longer OS than HER2-Zero patients (p = 0.012). The data from present study confirmed the clinical importance of HER2-Low expression in TNBC. Further effort is needed to determine whether HER2-Low could be a more favorable prognostic marker for individual treatment.

Co-encapsulation of granzyme B and perforin in nanocapsules for tumour therapy: biomimicking immune cells.

Granzyme B (GrB)-based immunotherapy is of interest for cancer treatment. However, insufficient cellular uptake and a lack of targeting remain challenges to make use of GrB for solid tumour therapy. As GrB induced cell death requires the help of perforin (PFN), we designed a system (nGPM) for the co-delivery of GrB and PFN. Therefore, GrB and PFN were loaded in a porous polymeric nanocapsule rich in acetylcholine analogues and matrix metalloproteinase-2 (MMP-2) responsive peptides. The neutrally charged nGPM nanocapsules showed as long circulating time and accumulated at the tumour sites. Once in the tumour the outside shell of nanocapsules became degraded by overexpressed MMP-2 proteases, resulting in the release of GrB and PFN. We found that the PFN complex formed small pores on the surface of tumour cells which allow GrB to enter the cytoplasm of tumour cells inducing cell apoptosis and tumour suppression significantly.

Facile Preparation of High-Performance Reduced Graphene Oxide (RGO)/Copper (Cu) Composites Based on Pyrolysis of Copper Formate.

Graphene has attracted much interest in many scientific fields because of its high specific surface area, Young's modulus, fracture strength, carrier mobility and thermal conductivity. In particular, the graphene oxide (GO) prepared by chemical exfoliation of graphite has achieved low-cost and large-scale production and is one of the most promising for Cu matrix composites. Here, we prepared a high strength, high electrical conductivity and high thermal conductivity reduced graphene oxide (RGO)/Cu composite by directly heating the GO/copper formate. The oxygen-containing functional groups and defects of RGO are significantly reduced compared with those of GO. The tensile yield strength and thermal conductivity of RGO/Cu composite with RGO volume fraction of 0.49 vol.% are as high as 553 MPa and 364 W/(m·K) at room temperature, respectively. The theoretical value of the tensile yield strength of the composite is calculated according to the strengthening mechanism, and the result shows that it agrees with the experimental value. After hot-rolling treatment, the ductility and conductivity of the composite materials have been greatly improved, and the ductility of the RGO/Cu composite with RGO volume fraction of 0.49 vol.% has been increased to four times the original. This work provides a highly efficient way to fabricate a high-performance RGO-reinforced Cu composite for commercial application.

Evaluation of predictive and prognostic value of androgen receptor expression in breast cancer subtypes treated with neoadjuvant chemotherapy.

BACKGROUND: Neoadjuvant chemotherapy is the standard treatment for local advanced breast cancer administered to shrink tumors and destroy undetected metastatic cells, thereby facilitating subsequent surgery. Previous studies have shown that AR may be used as a prognostic predictor in breast cancers, but its role in neoadjuvant therapy and the relationship with prognosis of different molecular subtypes of breast cancer need to be further explored. METHODS: We retrospectively evaluated 1231 breast cancer patients with complete medical records at Tianjin Medical University Cancer Institute and Hospital who were treated with neoadjuvant chemotherapy between January 2018 to December 2021. All the patients were selected for prognostic analysis. The follow-up time ranged from 12 to 60 months. We first analyzed the AR expression in different subtypes of breast cancer and its correlation with clinicopathological features. Meanwhile, the association of AR expression and pCR of different breast cancer subtypes was investigated. Finally, the effect of AR status on the prognosis of different subtypes of breast cancer after neoadjuvant therapy was analyzed. RESULTS: The positive rates of AR expression in HR + /HER2-, HR + /HER2 +, HR-/HER2 + and TNBC subtypes were 82.5%, 86.9%, 72.2% and 34.6%, respectively. Histological grade III (P = 0.014, OR = 1.862, 95% CI 1.137 to 2.562), ER positive expression (P = 0.002, OR = 0.381, 95% CI 0.102 to 0.754) and HER2 positive expression (P = 0.006, OR = 0.542, 95% CI 0.227 to 0.836) were independent related factors for AR positive expression. AR expression status was associated with pCR rate after neoadjuvant therapy only in subtype of TNBC. AR positive expression was independent protective factor for recurrence and metastasis in HR + /HER2- (P = 0.033, HR = 0.653, 95% CI 0.237 to 0.986) and HR + /HER2 + breast cancer (P = 0.012, HR = 0.803, 95% CI 0.167 to 0.959), but was independent risk factors for recurrence and metastasis in TNBC (P = 0.015, HR = 4.551, 95% CI 2.668 to 8.063). AR positive expression is not an independent predictor of HR-/HER2 + breast cancer. CONCLUSIONS: AR expressed the lowest in TNBC, but it could be a potential marker for the prediction of pCR in neoadjuvant therapy. AR negative patients had a higher pCR rate. AR positive expression was an independent risk factor for pCR in TNBC after neoadjuvant therapy (P = 0.017, OR = 2.758, 95% CI 1.564 to 4.013). In HR + /HER2- subtype and in HR + /HER2 + subtype, the DFS rate in AR positive patients and AR negative patients was 96.2% vs 89.0% (P = 0.001, HR = 0.330, 95% CI 0.106 to 1.034) and was 96.0% vs 85.7% (P = 0.002, HR = 0.278, 95% CI 0.082 to 0.940), respectively. However, in HR-/HER2 + and TNBC subtypes, the DFS rate in AR positive patients and AR negative patients was 89.0% vs 95.9% (P = 0.102, HR = 3.211, 95% CI 1.117 to 9.224) and 75.0% vs 93.4% (P < 0.001, HR = 3.706, 95% CI 1.681 to 8.171), respectively. In HR + /HER2- and HR + /HER2 + breast cancer, AR positive patients had a better prognosis, however in TNBC, AR-positive patients have a poor prognosis.

The putative tumor suppressor miR-524-5p directly targets Jagged-1 and Hes-1 in glioma.

Notch pathway plays critical role in stem cell maintenance and angiogenesis, as well as cell fate decisions of cancer. However, concrete mechanisms of notch pathway regulation in glioma were not well known, especially mediated by microRNAs. In this study, we identified a brain-specific miRNA, miR-524-5p, which was associated with the pathological grade and overall survival of gliomas. Restorated expression of miR-524-5p in glioma suppressed cell proliferation and invasion both in vitro and in vivo. Using bioinformatics and biological approaches, we found that Jagged-1 and Hes-1, two key components of notch pathway, were direct targets of miR-524-5p. Knocking down of Jagged-1 or Hes-1 partially phenocopied miR-524-5p re-expression, whereas forced expression of Jagged-1 or Hes-1 reversed the effects of miR-524-5p on proliferation and invasion of glioma. Moreover, miR-524-5p levels in glioma samples were inversely correlated with Jagged-1 and Hes-1 and their overexpressions were associated with poor survival. Thus, we have identified that miR-524-5p behaves as a tumor suppressor by negatively targeting Jagged-1 and Hes-1 and provides an additional option to inhibit this oncogene in gliomas.

High level of miR-221/222 confers increased cell invasion and poor prognosis in glioma.

BACKGROUND: MiR-221 and miR-222 (miR-221/222), upregulated in gliomas, can regulate glioma cell cycle progression and apoptosis, respectively. However, the association of miR-221/222 with glioma cell invasion and survival remains unknown. METHODS: Invasion capability of miR-221/222 was detected by mutiple analyses, including diffusion tensor imaging (DTI), transwell, wound healing and nude mouse tumor xenograft model assay. Further, the target of miR-221/222 was determined by luciferase reporter, western blot and gene rescue assay. The association of miR-221/222 with outcome was examined in fifty glioma patients. RESULTS: MiR-221/222 expression was significantly increased in high-grade gliomas compared with low-grade gliomas, and positively correlated with the degree of glioma infiltration. Over-expression of miR-221/222 increased cell invasion, whereas knockdown of miR-221/222 decreased cell invasion via modulating the levels of the target, TIMP3. Introduction of a TIMP3 cDNA lacking 3' UTR abrogated miR-221/222-induced cell invasion. In addition, knockdown of miR-221/222 increased TIMP3 expression and considerably inhibited tumor growth in a xenograft model. Finally, the increased level of miR-221/222 expression in high-grade gliomas confers poorer overall survival. CONCLUSIONS: The present data indicate that miR-221 and miR-222 directly regulate cell invasion by targeting TIMP3 and act as prognostic factors for glioma patients.

Sequence-dependent synergistic inhibition of human glioma cell lines by combined temozolomide and miR-21 inhibitor gene therapy.

Down-regulation of microRNA-21 (miR-21) can induce cell apoptosis and reverse drug resistance in cancer treatments. In this study, we explored the most effective schedule of the miR-21 inhibitor (miR-21i) and Temozolomide (TMZ) combined treatment in human glioma cells. Three tumor cell lines, U251 phosphatase and tensin homologue (PTEN) mutant, LN229 (PTEN wild-type), and U87 (PTEN loss of function), were subjected to evaluate the antitumor effects of deigned treatments (a predose of miR-21i for 4/8 h and then a subsequent TMZ treatment, a predose of TMZ for 4/8 h and then a subsequent miR-21i treatment, or a concomitant treatment) in vitro. A synergistic antiproliferative and proapoptotic activity was only obtained in U251 and U87 cells when a predose was administered for 4 h before the treatment of the other therapeutic agent, while the best antitumor effect in LN229 cells was achieved by using the concomitant treatment. Our data indicate that the effect of sequence and timing of administration is dependent on the PTEN status of cell lines. The best suppression effect was achieved by a maximal inhibition of STAT3 and phosphorylated STAT3, in PTEN loss of function cells. Our results reveal that both the sequence and the timing of administration are crucial in glioma combination therapy.

A novel Granzymes and miRNA nanocapsules co-delivery system for tumor suppression.

Granzymes-based immunotherapy for the treatment of solid tumors has gained great success and played more and more important effect in clinical studies. However, the antitumor effect of Granzymes still requires improvements owing to the cell evasion and metastasis of cancer. To overcome these limitations, synergistic combinatorial anti-tumor effect of Granzyme B (GrB) and miR-21 inhibitor (miR-21i) for breast cancer therapy through a new co-delivery system was investigated in present study. GrB was covalently bonded with miR-21i by disulfide bond and encapsulated in a nanocapsule formed byin situpolymerization of N -(3-aminopropyl) methacrylamide (APM), ethylene glycol dimethacrylate (EGDMA) and 2-Methacryloyloxyethyl phosphorylcholine (MPC). The nanocapsules possessed spherical and uniform diameter size as well as pH responsiveness in various environments. MTT and flow cytometry analysis showed that a synergistic anti-proliferation and promoting apoptosis effect was achieved when the nanocapsules were added into breast cancer cell lines. More importantly, the cell evasion ability was markedly inhibited using the nanocapusles detected through transwell invasion assay. Also thein vivoanti-tumor therapeutic efficacy of GrB-miR-21i nanocapusles was evaluated in a mouse tumor model. In conclusion, the nanocapsules for simultaneously delivery of GrB and miR-21i produce a synergistic effect in human breast cancer therapy.

Deciphering the performance of polo-like kinase 1 in triple-negative breast cancer progression according to the centromere protein U-phosphorylation pathway.

In general, the lack of effective therapeutic targets has led to the poor prognosis of triple-negative breast cancer (TNBC). Polo-like kinase 1 (PLK1) has been studied extensively as an effective therapeutic objective for the progression of tumor. Although the fundamental strategy and function of PLK1 in TNBC are still unclear. Here, we demonstrated that PLK1 upregulation was significantly correlated with poor prognosis in breast cancer cases utilizing the TCGA database. Additionally, ectopic PLK1 expression promoted TNBC cell proliferation, VEGFA production, and endothelial cell tube formation, whereas PLK1 knockdown induced the opposite effects. Moreover, expression of PLK1 K82R, the kinase-dead mutant of PLK1, completely inhibited PLK1-mediated cell proliferation, VEGFA production, and tube formation. Gene Set Enrichment Analysis (GSEA) showed that PLK1 expression significantly correlated with mitosis and the VEGF signaling pathway. We further observed that PLK1 phosphorylated centromere protein U (CENPU) at residue T78, thereby regulating the signaling pathway of COX-2/HIF-1α/VEGFA and the metaphase-anaphase transition of mitosis. The mechanism underlying the activity of PLK1 was also determined using a TNBC xenograft mouse model. Moreover, a PLK1 inhibitor effectively inhibited TNBC progression. Taken together, our results revealed that PLK1 plays an important role in TNBC progression via its kinase activity and phosphorylation of CENPU. Thus, PLK1 is an effective therapeutic objective for TNBC.

Chidamide Combined With Doxorubicin Induced p53-Driven Cell Cycle Arrest and Cell Apoptosis Reverse Multidrug Resistance of Breast Cancer.

The multidrug-resistant (MDR) phenotype is usually accompanied by an abnormal expression of histone deacetylase (HDAC). Given that HDAC is vital in chromatin remodeling and epigenetics, inhibiting the role of HDAC has become an important approach for tumor treatment. However, the effect of HDAC inhibitors on MDR breast cancer has not been elucidated. This study aim to demonstrate the potential of chidamide (CHI) combined with the chemotherapy drug doxorubicin (DOX) to overcome chemotherapeutic resistance of breast cancer in vitro and in vivo, laying the experimental foundation for the next clinical application. The results showed that, CHI combined with DOX showed significant cytotoxicity to MDR breast cancer cells in vitro and in vivo compared with the CHI monotherapy. The cell cycle distribution results showed that CHI caused G0/G1 cell cycle arrest and inhibited cell growth regardless of the addition of DOX. At the same time, annexin V staining and TUNEL staining results showed that CHI enhanced the number of cell apoptosis in drug-resistant cells. The western blot analysis found that p53 was activated in the CHI-treated group and combined treatment group, and then the activated p53 up-regulated p21, apoptosis regulator recombinant protein (Puma), and pro-apoptotic protein Bax, down-regulated the apoptotic proteins Bcl-xL and Bcl-2, and activated the caspase cascade to induce apoptosis.

Over-Expression of Centromere Protein U Participates in the Malignant Neoplastic Progression of Breast Cancer.

The expression of Centromere Protein U (CENP-U) is closely related to tumor malignancy. Till now, the role of CENP-U in the malignant progression of breast cancer remains unclear. In this study, we found that CENP-U protein was highly expressed in the primary invasive breast cancer tissues compared to the paired adjacent histologically normal tissues and ductal carcinoma in situ (DCIS) tissues. After CENP-U was knocked down, the proliferation and colony-forming abilities of breast cancer cells were significantly suppressed, whereas the portion of apoptotic cells was increased. Meanwhile, the PI3K/AKT/NF-κB pathway was significantly inhibited. In vivo studies showed that, the inhibition of CENP-U repressed the tumor growth in orthotopic breast cancer models. Therefore, our study demonstrated that the CENP-U might act as an oncogene and promote breast cancer progression via activation of the PI3K/AKT/NF-κB pathway, which suggests a promising direction for targeting therapy in breast cancer.

Chemotherapy-elicited exosomal miR-378a-3p and miR-378d promote breast cancer stemness and chemoresistance via the activation of EZH2/STAT3 signaling.

BACKGROUND: Not all breast cancer (BC) patients who receive neoadjuvant chemotherapy achieve a pathologic complete response (pCR), but the reasons for this are unknown. Previous studies have shown that exosomes produced in the tumor microenvironment in response to chemotherapy promote a chemotherapy-resistant phenotype in tumors. However, the role of BC chemotherapy-elicited exosomes in regulating chemoresistance is poorly understood. METHODS: Using commercial kits, serum exosomes were extracted from patients before neoadjuvant chemotherapy, after one cycle of chemotherapy and after four cycles of chemotherapy consisting of doxorubicin (DOX) and paclitaxel (PTX). Their miRNAs were sequenced, and the correlation between the sequencing results and chemotherapy effects was further verified by RT-qPCR using patient serum exosomes. Cell Counting Kit-8 (CCK-8) was used to detect chemosensitivity. Stemness was assessed by CD44+/CD24- population analysis and mammosphere formation assays. Chromatin immunoprecipitation (ChIP) experiments were performed to verify the binding of signal transducer and activator of transcription 3 (STAT3) to the promoter of miRNAs. RESULTS: Here, we provide clinical evidence that chemotherapy-elicited exosomal miR-378a-3p and miR-378d are closely related to the chemotherapy response and that exosomes produced by BC cells after stimulation with DOX or PTX deliver miR-378a-3p and miR-378d to neighboring cells to activate WNT and NOTCH stemness pathways and induce drug resistance by targeting Dickkopf 3 (DKK3) and NUMB. In addition, STAT3, which is enhanced by zeste homolog 2 (EZH2), bound to the promoter regions of miR-378a-3p and miR-378d, thereby increasing their expression in exosomes. More importantly, chemotherapeutic agents combined with the EZH2 inhibitor tazemetostat reversed chemotherapy-elicited exosome-induced drug resistance in a nude mouse tumor xenograft model. CONCLUSION: This study revealed a novel mechanism of acquired chemoresistance whereby chemotherapy activates the EZH2/STAT3 axis in BC cells, which then secrete chemotherapy-elicited exosomes enriched in miR-378a-3p and miR-378d. These exosomes are absorbed by chemotherapy-surviving BC cells, leading to activation of the WNT and NOTCH stem cell pathways via the targeting of DKK3 and NUMB and subsequently resulting in drug resistance. Therefore, blocking this adaptive mechanism during chemotherapy may reduce the development of chemotherapy resistance and maximize the therapeutic effect.

MiR-221 and miR-222 target PUMA to induce cell survival in glioblastoma.

BACKGROUND: MiR-221 and miR-222 (miR-221/222) are frequently up-regulated in various types of human malignancy including glioblastoma. Recent studies have reported that miR-221/222 regulate cell growth and cell cycle progression by targeting p27 and p57. However the underlying mechanism involved in cell survival modulation of miR-221/222 remains elusive. RESULTS: Here we showed that miR-221/222 inhibited cell apoptosis by targeting pro-apoptotic gene PUMA in human glioma cells. Enforced expression of miR-22/222 induced cell survival whereas knockdown of miR-221/222 rendered cells to apoptosis. Further, miR-221/222 reduced PUMA protein levels by targeting PUMA-3'UTR. Introducing PUMA cDNA without 3'UTR abrogated miR-221/222-induced cell survival. Notably, knockdown of miR-221/222 induces PUMA expression and cell apoptosis and considerably decreases tumor growth in xenograft model. Finally, there was an inverse relationship between PUMA and miR-221/222 expression in glioma tissues. CONCLUSION: To our knowledge, these data indicate for the first time that miR-221/222 directly regulate apoptosis by targeting PUMA in glioblastoma and that miR-221/222 could be potential therapeutic targets for glioblastoma intervention.

Centromere protein U (CENPU) enhances angiogenesis in triple-negative breast cancer by inhibiting ubiquitin-proteasomal degradation of COX-2.

Triple-negative breast cancer (TNBC) is characterized by high vascularity, but anti-angiogenic therapies show poor efficacy. Centromere protein U (CENPU), a centromere component essential for mitosis, is associated with tumorigenesis in multiple cancers; however, little is known of its role in breast cancer. Here, we investigate its expression and function of promoting angiogenesis in TNBC. Immunohistochemical staining revealed high CENPU expression in TNBC tissue and high CENPU levels correlated significantly with poor distant metastasis-free and overall survival. Knockdown of CENPU in TNBC cells inhibited vascular endothelial growth factor A (VEGFA) production and significantly reduced tube formation and migration of human umbilical vein endothelial cells in vitro. In a mouse xenograft model, CENPU knockdown reduced TNBC tumor growth concomitant with a reduction in CD31 + microvessel density. Mechanistic studies revealed that CENPU promoted angiogenesis by inhibiting the ubiquitination and proteasomal degradation of cyclooxygenase-2 (COX-2), leading to increased activation of the COX-2-p-ERK-HIF-1α-VEGFA signaling pathway. Taken together, our results demonstrate a critical role for CENPU in COX-2-mediated signaling for angiogenesis, and identify a role of CENPU in regulating angiogenesis in TNBC.

A novel Granzyme B nanoparticle delivery system simulates immune cell functions for suppression of solid tumors.

Cell-based immunotherapy for the treatment of hematologic malignancies, such as leukemia and lymphoma, has seen much success and played an increasingly important role in clinical studies. Nevertheless, the efficacy of immunotherapy in solid tumors still needs improvements due to the immunosuppressive properties of tumor cells and the microenvironment. To overcome these limitations, we prepared a novel tumor-targeting delivery system based on the underlying mechanism of immune-targeted cell death that encapsulated granzyme B protein within a porous polymeric nanocapsule. Methods: A cell-penetrating peptide TAT was attached onto granzyme B (GrB) to enhance its transmembrane transport efficiency and potency to induce cell apoptosis. The endocytosis and internalization pathways of GrB-TAT (GrB-T) were analyzed in comparison with perforin by confocal microscopy and flow cytometry. Furthermore, the positively charged GrB-T was wrapped into nanoparticles by p-2-methacryloyloxy ethyl phosphorylcholine (PMPC)-modified HA (hyaluronic acid). The nanoparticles (called TCiGNPs) were characterized in terms of zeta potential and by transmission electron microscopy (TEM). The in vitro anti-tumor effects of GrB-T were examined by cell apoptosis assay and Western blotting analysis. The in vivo anti-tumor therapeutic efficacy of TCiGNPs was evaluated in a mouse tumor model. Results: The TAT peptide could play a role similar to perforin to mediate direct transmembrane transfer of GrB and improve GrB-induced cell apoptosis. The TCiGNPs were successfully synthesized and accumulated in the solid tumor through enhanced permeability and retention (EPR) effect. In the tumor microenvironment, TCiGNPs could be degraded by hyaluronidase and triggered the release of GrB-T. The TAT peptide enabled the translocation of GrB across the plasma membrane to induce tumor cell apoptosis in vivo.Conclusion: We successfully developed a granzyme B delivery system with a GrB-T core and a PMPC/HA shell that simulated CTL/NK cell-mediated cancer immunotherapy mechanism. The GrB delivery system holds great promise for cancer treatment analogous to the CTL/NK cell-induced immunotherapy.