Herpud1 modulates hypertrophic signals independently of calmodulin nuclear translocation in rat myocardium-derived H9C2 cells.

In this study, we aimed to analyze the role of the Homocysteine-responsive endoplasmic reticulum-resident ubiquitin-like domain member 1 (Herpud1) gene in the development of cardiomyocyte hypertrophy in association with Calmodulin (CaM) nuclear translocation and cytosolic Ca2+ levels. To observe the mobilization of CaM in cardiomyocytes, we stably expressed eGFP-CaM in rat myocardium-derived H9C2 cells. These cells were then treated with Angiotensin II (Ang II), which stimulates a cardiac hypertrophic response, or dantrolene (DAN), which blocks the release of intracellular Ca2+. To observe intracellular Ca2+ in the presence of eGFP fluorescence, a Rohd-3 Ca2+ sensing dye was used. To examine the effect of suppressing Herpud1 expression, Herpud1 small interfering RNA (siRNA) were transfected into H9C2 cells. To examine whether hypertrophy induced by Ang II could be suppressed by Herpud1 overexpression, a Herpud1-expressing vector was introduced into H9C2 cells. CaM translocation was observed using eGFP fluorescence. Nuclear translocation of Nuclear factor of activated T-cells, cytoplasmic 4 (NFATc4) and nuclear export of Histone deacetylase 4 (HDAC4) were also examined. First, Ang II induced H9C2 hypertrophy with nuclear translocation of CaM and elevation of cytosolic Ca2+, which were inhibited by DAN treatment. We also found that Herpud1 overexpression suppressed Ang II-induced cellular hypertrophy without preventing nuclear translocation of CaM or elevation of cytosolic Ca2+. Additionally, Herpud1 knockdown induced hypertrophy without the nuclear translocation of CaM, which was not inhibited by DAN treatment. Finally, Herpud1 overexpression suppressed Ang II-induced NFATc4 nuclear translocation but did not suppress Ang II-induced CaM nuclear translocation or HDAC4 nuclear export. Ultimately, this study lays the groundwork for elucidating the anti-hypertrophic effects of Herpud1 and the underlying mechanism of pathological hypertrophy.

Dantrolene reduces platelet-derived growth factor (PDGF)-induced vascular smooth muscle cell proliferation and neointimal formation following vascular injury in mice.

Dantrolene is a ryanodine receptor blocker that is used clinically for treatment of malignant hyperthermia. This study was conducted using murine aortic vascular smooth muscle cells (MOVAS) and a mouse arterial injury model to investigate the inhibitory effect of dantrolene on smooth muscle cell proliferation and migration. We investigated whether dantrolene suppressed platelet-derived growth factor (PDGF)-induced vascular smooth muscle cell proliferation and migration in vitro. The effect of dantrolene on smooth muscle phenotype was evaluated using immunostaining. In addition, smooth muscle cell proliferation and phenotype switching were tested by applying dantrolene around blood vessels using a mouse arterial injury model. Dantrolene inhibited PDGF-induced cell proliferation and migration of MOVAS. Dantrolene also inhibited the switch from contractile to synthetic phenotype both in vitro and in vivo. Dantrolene is effective at inhibiting vascular smooth muscle cell proliferation, migration, and neointimal formation following arterial injury in mice.

Disruption of Circulating Extracellular Vesicles as a Novel Therapeutic Strategy against Cancer Metastasis.

Metastasis is the main cause of cancer mortality for many types of cancer; however, difficulties remain in effectively preventing metastasis. It has been recently and widely reported that cancer-derived extracellular vesicles (EVs) contribute to cancer metastasis. Thus, therapeutic strategies targeting cancer-derived EVs hold great promise because of the possibility of EVs driving the cancer microenvironment toward metastasis. Here, we provide a novel strategy for therapeutic antibody treatment to target cancer-derived EVs and inhibit the metastasis of breast cancer in a mouse model, establishing a rationale for further clinical investigation. Treatment with human-specific anti-CD9 or anti-CD63 antibodies significantly decreased metastasis to the lungs, lymph nodes, and thoracic cavity, although no obvious effects on primary xenograft tumor growths were observed. In in vitro and in vivo experiments, the EVs incubated with the targeted antibodies were preferentially internalized by macrophages, suggesting that antibody-tagged cancer-derived EVs would be eliminated by macrophages. Our results suggested that therapeutic antibody administration effectively suppresses EV-triggered metastasis in cancer and that the removal of EVs could be a novel strategy for cancer therapy.

Micromanaging of tumor metastasis by extracellular vesicles.

Extracellular vesicles (EVs) are nanometer-sized membranous vesicles that are released by a variety of cell types into the extracellular space. In the past two decades, EVs have emerged as novel mediators of cancer biology. Many reports have demonstrated the contribution of EVs to cancer metastasis. Metastasis is a multistep process that is responsible for the majority of deaths in cancer patients. This process includes proliferation, angiogenesis, immune modulation, extravasation, intravasation, and colonization. EVs from cancer cells impact these steps through modulation of the host immune system, angiogenesis, and pre-/pro-metastatic niche formation. In this review, we summarize the function of EVs in cancer metastasis. In addition, we also discuss the hurdles to be overcome for further developing this research field.

RPN2-mediated glycosylation of tetraspanin CD63 regulates breast cancer cell malignancy.

BACKGROUND: The tetraspanin CD63 is a highly N-glycosylated protein that is known to regulate cancer malignancy. However, the contribution of glycosylation of CD63 to cancer malignancy remains unclear. Previously, we reported that ribophorin II (RPN2), which is part of an N-oligosaccharyle transferase complex, is responsible for drug resistance in breast cancer cells. In this study, we demonstrate that cancer malignancy associated with the glycosylation of CD63 is regulated by RPN2. RESULTS: Inhibition of RPN2 expression led to a reduction in CD63 glycosylation. In addition, the localization of CD63 was deregulated by knockdown of RPN2. Interestingly, multidrug resistance protein 1 (MDR1) localization was displaced from the cell surface in CD63-silenced cells. CD63 silencing reduced the chemoresistance and invasion ability of malignant breast cancer cells. Furthermore, the enrichment of CD63/MDR1-double positive cells was associated with lymph node metastasis. Taken together, these results indicated that high glycosylation of CD63 by RPN2 is implicated in clinical outcomes in breast cancer patients. CONCLUSIONS: These findings describe a novel and important function of RPN2-mediated CD63 glycosylation, which regulates MDR1 localization and cancer malignancy, including drug resistance and invasion.

Dark side of the exosome: the role of the exosome in cancer metastasis and targeting the exosome as a strategy for cancer therapy.

Cell-cell communication is essential for the regulation of various biological phenomena in multicellular organisms, including development and homeostasis. Deregulation of these interactions leads to inappropriate cell-cell communication, resulting in disease development. Cancer cells communicate closely with the cells in their microenvironment, and this communication promotes malignancy via abnormal growth, invasion, drug resistance and metastasis. Understanding cell-cell interactions in cancer is essential for the development of novel anticancer agents. As a result, discovering the communication tools used by cancer cells is important to understanding these interactions. In this review, we summarize the recent findings regarding exosome-mediated cancer development. In addition, we propose that targeting the exosome represents a novel strategy for cancer therapy.

4-Phenylbutyrate restores localization and membrane repair to human dysferlin mutations.

Dysferlinopathies are muscular dystrophies caused by recessive loss-of-function mutations in dysferlin (DYSF), a membrane protein involved in skeletal muscle membrane repair. We describe a cell-based assay in which human DYSF proteins bearing missense mutations are quantitatively assayed for membrane localization by flow cytometry and identified 64 localization-defective DYSF mutations. Using this platform, we show that the clinically approved drug 4-phenylbutryric acid (4-PBA) partially restores membrane localization to 25 mutations, as well as membrane repair to cultured myotubes expressing 2 different mutations. Two-day oral administration of 4-PBA to mice homozygous for one of these mutations restored myofiber membrane repair. 4-PBA may hold therapeutic potential for treating a subset of humans with muscular dystrophy due to dysferlin deficiency.

Herpud1 suppress angiotensin II induced hypertrophy in cardiomyocytes.

Purpose: The purpose of this study was to analyze the role of homocysteine-responsive endoplasmic reticulum-resident ubiquitin-like domain member 1 (Herpud1) gene in the development of cardiomyocyte hypertrophy. Method: In order to examine the effect of suppressing Herpud1 expression, Herpud1 small interfering RNA (siRNA) was introduced into H9C2 cells, which are cell lines derived from rat myocardium, and the degree of Herpud1 protein expression and cell hypertrophy in the Herpud1 siRNA-transfected group and the control group was compared by immunostaining 48 h after Herrpud1 siRNA introduction. To examine whether hypertrophy induced by angiotensin II (Ang II) can be suppressed by the overexpression of Herpud1, the green fluorescent protein (GFP)-Herpud1 plasmid was introduced into H9C2 cells, and the degree of cell hypertrophy was examined in the GFP-Herpud1-and control groups for 48 h. Nuclear translocation of nuclear factor of activated T-cells, cytoplasmic 4 (NFATc4), a transcription factor for hypertrophic genes, was also examined. Results: [1] Herpud1 siRNA-transfected cells showed decreased Herpud1 protein expression and hypertrophy formation compared to control cells [2]; Overexpression of Herpud1 suppresses Ang II-induced cell hypertrophy; and [3] Overexpression of Herpud1 inhibits nuclear translocation of NFATc4. Discussion: It was suggested that Herpud1 might be an anti-hypertrophic gene in Ang II induced cardiomyocytes hypertrophy.

Prediction of pathologic complete response to sequential paclitaxel and 5-fluorouracil/epirubicin/cyclophosphamide therapy using a 70-gene classifier for breast cancers.

BACKGROUND: Sequential administration of paclitaxel plus combined fluorouracil, epirubicin, and cyclophosphamide (P-FEC) is 1 of the most common neoadjuvant chemotherapies for patients with primary breast cancer and produces pathologic complete response (pCR) rates of 20% to 30%. However, a predictor of pCR to this chemotherapy has yet to be developed. The authors developed such a predictor by using a proprietary DNA microarray for gene expression analysis of breast tumor tissues. METHODS: Tumor samples were obtained from 84 patients with breast cancer by core-needle biopsy before the patients received P-FEC, and the gene expression profile was analyzed in those samples to construct a classifier for predicting pCR to P-FEC. In addition, the authors analyzed the gene expression profile of tumor tissues that were obtained at surgery from 105 patients with lymph node-negative and estrogen receptor-positive breast cancer who received adjuvant hormone therapy alone to determine the prognostic significance of the classifier. RESULTS: The 70-gene classifier for predicting pCR to P-FEC was constructed by using the training set (n = 50) and subsequently was validated successfully in the validation set (n = 34), revealing high sensitivity (88%; 95% confidence interval [CI], 47%-100%) and high negative predictive value (93%; 95% CI, 68%-100%). Specificity and positive predictive value were 54% (95% CI, 33%-73%) and 37% (95% CI, 16%-62%), respectively. Among the various parameters (estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and Ki-67 status, etc), the 70-gene classifier had the strongest association with pCR (P = .015). In an additional study, genetically assumed complete responders were associated significantly (P = .047) with a poor prognosis. CONCLUSIONS: The 70-gene classifier that was constructed for predicting pCR to P-FEC for breast tumors was successful, with high sensitivity and high negative predictive value. The classifier also appeared to be useful for predicting the prognosis of patients with lymph node-negative and estrogen receptor-positive breast cancer who receive adjuvant hormone therapy alone.

Development of 95-gene classifier as a powerful predictor of recurrences in node-negative and ER-positive breast cancer patients.

Our aim was to develop an accurate diagnostic system using gene expression analysis by means of DNA microarray for prognosis of node-negative and estrogen receptor (ER)-positive breast cancer patients in order to identify a subset of patients who can be safely spared adjuvant chemotherapy. A diagnostic system comprising a 95-gene classifier was developed for predicting the prognosis of node-negative and ER-positive breast cancer patients by using already published DNA microarray (gene expression) data (n = 549) as the training set and the DNA microarray data (n = 105) obtained at our institute as the validation set. Performance of the 95-gene classifier was compared with that of conventional prognostic factors as well as of the genomic grade index (GGI) based on the expression of 70 genes. With the 95-gene classifier we could classify the 105 patients in the validation set into a high-risk (n = 44) and a low-risk (n = 61) group with 10-year recurrence-free survival rates of 93 and 53%, respectively (P = 8.6e-7). Multivariate analysis demonstrated that the 95-gene classifier was the most important and significant predictor of recurrence (P = 9.6e-4) independently of tumor size, histological grade, progesterone receptor, HER2, Ki67, or GGI. The 95-gene classifier developed by us can predict the prognosis of node-negative and ER-positive breast cancer patients with high accuracy. The 95-gene classifier seems to perform better than the GGI. As many as 58% of the patients classified into the low-risk group with this classifier could be safely spared adjuvant chemotherapy.

Anti-Cancer Role and Therapeutic Potential of Extracellular Vesicles.

Cell-cell communication is an important mechanism in biological processes. Extracellular vesicles (EVs), also referred to as exosomes, microvesicles, and prostasomes, are microvesicles secreted by a variety of cells. EVs are nanometer-scale vesicles composed of a lipid bilayer and contain biological functional molecules, such as microRNAs (miRNAs), mRNAs, and proteins. In this review, "EVs" is used as a comprehensive term for vesicles that are secreted from cells. EV research has been developing over the last four decades. Many studies have suggested that EVs play a crucial role in cell-cell communication. Importantly, EVs contribute to cancer malignancy mechanisms such as carcinogenesis, proliferation, angiogenesis, metastasis, and escape from the immune system. EVs derived from cancer cells and their microenvironments are diverse, change in nature depending on the condition. As EVs are thought to be secreted into body fluids, they have the potential to serve as diagnostic markers for liquid biopsy. In addition, cells can encapsulate functional molecules in EVs. Hence, the characteristics of EVs make them suitable for use in drug delivery systems and novel cancer treatments. In this review, the potential of EVs as anti-cancer therapeutics is discussed.

Altered biodistribution of deglycosylated extracellular vesicles through enhanced cellular uptake.

Extracellular vesicles (EVs) from cancer are delivered both proximal and distal organs. EVs are highly glycosylated at the surface where EVs interact with cells and therefore has an impact on their properties and biological functions. Aberrant glycosylation in cancer is associated with cancer progression and metastasis. However, the biological function of glycosylation on the surface of EV is uncovered. We first demonstrated differential glycosylation profiles of EVs and their originated cells, and distinct glycosylation profiles in a brain-metastatic subline BMD2a from its parental human breast cancer cell line, MDA-MB-231-luc-D3H2LN by lectin blot. We then investigated the roles of surface glycoconjugates on EV uptake. N- and/or O-glycosylation removal of fluorescent-labelled BMD2a EVs enhanced cellular uptake to endothelial cells, suggesting that surface glycosylation has inhibitory effects on cellular uptake. Biodistribution of glycosylation-deprived BMD2a EVs administrated intravenously into mice was further analysed ex vivo using near-infrared lipophilic dye. EVs treated with O-deglycosylation enzymes enhanced the accumulation of EVs to the lungs after 24 h from the injection, while N-deglycosylation did not markedly alter biodistribution. As the lungs are first organs in which intravenous blood flows, we suggest that surface glycosylation of cancer-derived EVs avoid promiscuous adhesion to proximal tissues to be delivered to distant organs.

A novel platform for cancer therapy using extracellular vesicles.

Extracellular vesicles (EVs) are nanometer-sized membranous vesicles and are involved in cell-to-cell communication. EVs contain several types of functional molecules, such as proteins, mRNAs, and microRNAs (miRNAs). Over the past several years, EVs have emerged as potential tools for a drug delivery system (DDS) that can target organs or cells. EVs have a function of organ tropism and are naturally occurring from cells. Therefore, EVs have expected as naturally DDSs, which have the organ tropism and a low side effect. Actually, some reports showed that EVs delivered drugs to specific organ. However, despite observed the organ tropism, the mechanisms of organ tropism of EVs are still unclear. Moreover, preservation and efficient collection of EVs are desired to be investigated. Here, we provide an overview of the methods for using EVs as DDSs.

Brain metastatic cancer cells release microRNA-181c-containing extracellular vesicles capable of destructing blood-brain barrier.

Brain metastasis is an important cause of mortality in breast cancer patients. A key event during brain metastasis is the migration of cancer cells through blood-brain barrier (BBB). However, the molecular mechanism behind the passage through this natural barrier remains unclear. Here we show that cancer-derived extracellular vesicles (EVs), mediators of cell-cell communication via delivery of proteins and microRNAs (miRNAs), trigger the breakdown of BBB. Importantly, miR-181c promotes the destruction of BBB through the abnormal localization of actin via the downregulation of its target gene, PDPK1. PDPK1 degradation by miR-181c leads to the downregulation of phosphorylated cofilin and the resultant activated cofilin-induced modulation of actin dynamics. Furthermore, we demonstrate that systemic injection of brain metastatic cancer cell-derived EVs promoted brain metastasis of breast cancer cell lines and are preferentially incorporated into the brain in vivo. Taken together, these results indicate a novel mechanism of brain metastasis mediated by EVs that triggers the destruction of BBB.

Exosomes from bone marrow mesenchymal stem cells contain a microRNA that promotes dormancy in metastatic breast cancer cells.

Breast cancer patients often develop metastatic disease years after resection of the primary tumor. The patients are asymptomatic because the disseminated cells appear to become dormant and are undetectable. Because the proliferation of these cells is slowed, dormant cells are often unresponsive to traditional chemotherapies that exploit the rapid cell cycling of most cancer cells. We generated a bone marrow-metastatic human breast cancer cell line (BM2) by tracking and isolating fluorescent-labeled MDA-MB-231 cells that disseminated to the bone marrow in mice. Coculturing BM2 cells with bone marrow mesenchymal stem cells (BM-MSCs) isolated from human donors revealed that BM-MSCs suppressed the proliferation of BM2 cells, decreased the abundance of stem cell-like surface markers, inhibited their invasion through Matrigel Transwells, and decreased their sensitivity to docetaxel, a common chemotherapy agent. Acquisition of these dormant phenotypes in BM2 cells was also observed by culturing the cells in BM-MSC-conditioned medium or with exosomes isolated from BM-MSC cultures, which were taken up by BM2 cells. Among various microRNAs (miRNAs) increased in BM-MSC-derived exosomes compared with those from adult fibroblasts, overexpression of miR-23b in BM2 cells induced dormant phenotypes through the suppression of a target gene, MARCKS, which encodes a protein that promotes cell cycling and motility. Metastatic breast cancer cells in patient bone marrow had increased miR-23b and decreased MARCKS expression. Together, these findings suggest that exosomal transfer of miRNAs from the bone marrow may promote breast cancer cell dormancy in a metastatic niche.

Functional analysis of exosomal microRNA in cell-cell communication research.

Circulating microRNAs (miRNAs), also known as secretory miRNAs, are packaged in small membrane vesicles called exosomes. These exosomal miRNAs are secreted from various cell types and incorporated inside the recipient cells. The functions of exosomal miRNAs are poorly understood, but some reports have shown their essential roles in cancer development. Therefore, methods to study the function of exosomal miRNAs not only in vitro but also in vivo might be essential. We have analyzed the function of exosomal miRNAs by miRNA-enriched exosomes both in vitro and in vivo. In this chapter, the methods to concentrate the targeted miRNAs are provided. This simple and useful method enables the study of the precise mechanisms of exosomal miRNAs under physiological and pathological conditions.

Trash or Treasure: extracellular microRNAs and cell-to-cell communication.

Circulating RNAs in human body fluids are promising candidates for diagnostic purposes. However, the biological significance of circulating RNAs remains elusive. Recently, small non-coding RNAs, microRNAs (miRNAs), were isolated from multiple human body fluids, and these "circulating miRNAs" have been implicated as novel disease biomarkers. Concurrently, miRNAs were also identified in the extracellular space associated with extracellular vesicles (EVs), which are small membrane vesicles secreted from various types of cells. The function of these secreted miRNAs has been revealed in several papers. Circulating miRNAs have been experimentally found to be associated with EVs; however, other types of extracellular miRNAs were also described. This review discusses studies related to extracellular miRNAs, including circulating miRNAs and secreted miRNAs, to highlight the importance of studying not only secreted miRNAs, but also circulating miRNAs to determine the contribution of extracellular miRNAs especially in cancer development.

High genomic grade index associated with poor prognosis for lymph node-negative and estrogen receptor-positive breast cancers and with good response to chemotherapy.

BACKGROUND: The aim of the present study was to investigate the prognostic value of the genomic grade index for lymph node-negative and estrogen receptor (ER)-positive breast cancers of Japanese women treated with adjuvant hormonal therapy alone, as well as the relation between genomic grade index and pathological complete response (CR) to neoadjuvant chemotherapy. METHODS: Genomic grade index was determined by DNA microarray (U133plus2.0; Affymetrix, Santa Clara, Calif) in tumor tissues obtained from lymph node-negative and ER-positive breast cancers (n = 105) treated with adjuvant hormonal therapy alone or in breast tumor biopsy specimens (n = 84, Mammotome) obtained before neoadjuvant chemotherapy (paclitaxel followed by 5-fluorouracil/epirubicin/cyclophosphomide) to investigate the prognostic and predictive values of genomic grade index. RESULTS: Recurrence-free survival of patients with high genomic grade index tumors was significantly (P < .001) lower than that of patients with low genomic grade index tumors (55% vs 88%, 10 years after surgery). Multivariate analysis demonstrated that genomic grade index was the most important and significant predictive factor for disease recurrence (P = .013) independently of other prognostic factors, including tumor size, histological grade, progesterone receptor, human epidermal growth receptor 2, and Ki67. High genomic grade index tumors showed a significantly (P = .022) higher pathological CR rate for neoadjuvant chemotherapy than low genomic grade index tumors (31.9% [15 of 47] vs 10.8% [4 of 37]). CONCLUSIONS: Genomic grade index is a powerful prognostic factor for lymph node-negative and ER-positive tumors treated with adjuvant hormonal therapy alone, and high genomic grade index tumors are more likely to respond to chemotherapy. Genomic grade index also appears to be very useful for decision making regarding the need for adjuvant chemotherapy for lymph node-negative and ER-positive breast cancers.