Tumor development is initiated by an accumulation of numerous genetic and epigenetic alterations that promote tumor initiation, invasion and metastasis. Astrocyte elevated gene-1 [AEG-1; also known as Metadherin (MTDH) and Lysine-rich CEACAM1 co-isolated (LYRIC)] has emerged in recent years as a potentially crucial mediator of tumor malignancy, and a key converging point of a complex network of oncogenic signaling pathways. AEG-1/MTDH has a multifunctional role in tumor development that has been found to be involved in the following signaling cascades: i) The Ha-Ras and PI3K/Akt pathways; ii) the nuclear factor-κB signaling pathway; iii) the ERK/mitogen-activated protein kinase and Wnt/β-catenin pathways; and iv) the Aurora-A kinase signaling pathway. Studies have established that AEG-1/MTDH is crucial in tumor progression, including transformation, the evasion of apoptosis, invasion, angiogenesis and metastasis. In addition, recent clinical studies have convincingly associated AEG-1/MTDH with tumor progression and poor prognosis in a number of cancer types, including hepatocellular, esophageal squamous cell, gallbladder and renal cell carcinomas, breast, non-small cell lung, prostate, gastric and colorectal cancers, and glioma, melanoma, neuroblastoma and osteosarcoma. AEG-1/MTDH may be used as a biomarker to identify subgroups of patients who require more intensive treatments and who are likely to benefit from AEG-1/MTDH-targeted therapies. The therapeutic targeting of AEG-1/MTDH may simultaneously block metastasis, suppress tumor growth and enhance the efficacy of chemotherapeutic treatments.

The development of systemic therapy drug resistance for breast cancer treatment is an ongoing problem, thus, so are the potential molecular mechanisms of it. AZD6244 is a novel ATP-uncompetitive inhibitor to MAP/ERK kinase (MEK) 1/2 which has been demonstrated to be potent, selective and safe in the clinical trials and previous studies. However, the precise role of resistance to AZD6244 is largely unknown. We and other groups have reported that the novel oncogene Metadherin (MTDH) is associated with multiple drug resistance, but there is no report about its role in treatment of AZD6244. Here we report that the resistance to AZD6244 can be reserved by downregulating MTDH in breast cancer cell lines. When the MTDH was downregulated, the breast cancer cells exhibited a significantly increased sensitivity to AZD6244 as measured by MTT assay. After treated with AZD6244 the MTDH-knockdown cells showed more apoptosis rate and growth inhibition. We also showed that knockdown of MTDH cannot only increase expression of FOXO3a but also activate it by promoting its translocation via MTDH/ERK1/2/FOXO3a pathway rather than MTDH/AKT/FOXO3a pathway. In conclusion knockdown MTDH can enhance the breast cancer cells sensitivity to AZD6244 via regulating the expression and activity of FOXO3a. These indicate us that MTDH is a candidate marker to predict the clinical efficacy of AZD6244 and targeting MTDH could overcome the resistance to AZD6244 in breast cancer cells.

BACKGROUND

Ductal carcinoma in situ (DCIS) accounts for approximately 20% of mammographically detected breast cancers. Although DCIS is generally highly curable, some women with DCIS will develop life-threatening invasive breast cancer, but the determinants of progression to infiltrating ductal cancer (IDC) are largely unknown.

METHODS

In the current study, we used multiplex ligation-dependent probe amplification (MLPA), a multiplex PCR-based test, to compare copy numbers of 21 breast cancer related genes between laser-microdissected DCIS and adjacent IDC lesions in 39 patients. Genes included in this study were ESR1, EGFR, FGFR1, ADAM9, IKBKB, PRDM14, MTDH, MYC, CCND1, EMSY, CDH1, TRAF4, CPD, MED1, HER2, CDC6, TOP2A, MAPT, BIRC5, CCNE1 and AURKA.

RESULTS

There were no significant differences in copy number for the 21 genes between DCIS and adjacent IDC. Low/intermediate-grade DCIS showed on average 6 gains/amplifications versus 8 in high-grade DCIS (p = 0.158). Furthermore, alterations of AURKA and CCNE1 were exclusively found in high-grade DCIS, and HER2, PRDM14 and EMSY amplification was more frequent in high-grade DCIS than in low/intermediate-grade DCIS. In contrast, the average number of alterations in low/intermediate and high grade IDC was similar, and although EGFR alterations were exclusively found in high grade IDC compared to low/intermediate-grade IDC, there were generally fewer differences between low/intermediate-grade and high-grade IDC than between low/intermediate-grade and high-grade DCIS.

CONCLUSIONS

In conclusion, there were no significant differences in copy number for 21 breast cancer related genes between DCIS and adjacent IDC, indicating that DCIS is genetically as advanced as its invasive counterpart. However, high grade DCIS showed more copy number changes than low/intermediate grade DCIS with specifically involved genes, supporting a model in which different histological grades of DCIS are associated with distinct genomic changes that progress to IDC in different routes. These high grade DCIS specific genes may be potential targets for treatment and/or predict progression.

Although several studies have shown a dysregulation of microRNA (miRNA) expression profiles in cutaneous melanoma, there has been little research on the miRNA machinery itself. In this study, we investigated the mRNA expression profiles of different miRNA machinery components in primary cutaneous malignant melanoma (PCMM), cutaneous malignant melanoma metastases (CMMM) and benign melanocytic nevi (BMN). Patients with PCMM (n = 7), CMMM (n = 6) and BMN (n = 7) were included in the study. Punch biopsies were harvested from the centers of tumors (lesional) and from BMN (control). In contrast to previous reports exploring specific clusters of miRNAs in PCMM, the present study investigates mRNA expression levels of Dicer, Drosha, Exp5, DGCR8 and the RISC components PACT, argonaute-1, argonaute-2, TARBP1, TARBP2, MTDH and SND1, which were detected by TaqMan real-time reverse transcription polymerase chain reaction (RT-PCR). Argonaute-1, TARBP2 and SND1 expression levels were significantly higher in BMN compared to PCMM (p < 0.05). TARBP2 expression levels were significantly higher in CMMM compared to PCMM (p < 0.05). SND1 expression levels were significantly higher in CMMM compared to PCMM and BMN (p < 0.05). Dicer, Drosha, DGCR8, Exp5, argonaute-2, PACT, TARBP1 and MTDH expression levels showed no significant differences within groups (p>> 0.05). The results of this study show that the miRNA machinery components argonaute-1, TARBP2 and SND1 are dysregulated in PCMM and CMMM compared to BMN and may play a role in the process of malignant transformation.

Dysregulated microRNAs play important pathological roles in carcinogenesis that are yet to be fully elucidated. This study was performed to investigate the biological functions of microRNA-320a (miR-320a) in breast cancer and the underlying mechanisms. Function analyses for cell proliferation, cell cycle, and cell invasion/migration, were conducted after miR-320a silencing and overexpression. The specific target genes of miR-320a were predicted by TargetScan algorithm and then determined by dual luciferase reporter assay and rescue experiment. The relationship between miR-320a and its target genes was explored in human breast cancer tissues. We found that miR-320a overexpression could inhibit breast cancer invasion and migration abilities in vitro, while miR-320a silencing could enhance that. In addition, miR-320a could suppress activity of 3'-untranslated region luciferase of metadherin (MTDH), a potent oncogene. The rescue experiment revealed that MTDH was a functional target of miR-320a. Moreover, we found that MTDH was negatively correlated with miR-320a expression, and it was related to clinical outcomes of breast cancer. Further xenograft experiment also showed that miR-320a could inhibit breast cancer metastasis in vivo. Our findings clearly demonstrate that miR-320a suppresses breast cancer metastasis by directly inhibiting MTDH expression. The present study provides a new insight into anti-oncogenic roles of miR-320a and suggests that miR-320a/MTDH pathway is a putative therapeutic target in breast cancer.

Since the initial discovery of AEG-1/MTDH/LYRIC, our appreciation for this novel protein's involvement in cancer has increased dramatically over the past few years. AEG-1/MTDH/LYRIC is a key functional target of the 8q22 genomic gain that is frequently observed in poor-prognosis breast cancer, where it plays a dual role in promoting chemoresistance and metastasis. Beyond this, growing evidence from clinical research indicates a strong correlation between AEG-1/MTDH/LYRIC expression and the pathogenesis of a large spectrum of cancer types, and multiple studies employing in vitro cell culture systems and in vivo xenograft models have revealed multifaceted roles of AEG-1/MTDH/LYRIC in cancer biology, including tumor cell proliferation, apoptosis, angiogenesis, and autophagy. With increasing mechanistic understanding of AEG-1/MTDH/LYRIC, discovery of agents that can block AEG-1/MTDH/LYRIC and its regulated pathways will be beneficial to cancer patients with aberrant expression of AEG-1/MTDH/LYRIC.

Overexpression of metadherin (MTDH) has been reported in many solid tumors and implicated in chemoresistance. This study aimed to examine MTDH expression in cervical cancer tissues and explore its role in chemoresistance of cervical cancer. MTDH expression in cervical cancer biopsies and several cervical cancer cell lines was detected by immunoblotting and immunohistochemisty. MTDH expression level was experimentally modulated in HeLa cells to determine the effects on chemoresistance to cisplatin. The results showed that MTDH expression was higher in tissues from both cervical squamous carcinoma and cervical adenocarcinoma, compared to normal cervical tissues. MTDH expression was not correlated to patient age or cervical cancer grade, although nuclear MTDH expression was correlated with poor differentiation of cervical cancer. In SiHa, HeLa, CasKi, and C33A cells, MTDH expression level was positively correlated with chemoresistance to cisplatin. MTDH increased autophagy in HeLa cells, which was associated with decreased cleavage of Caspase-3 and the activation of EER/NF-κB pathway. In conclusion, MTDH expression is high in cervical cancer, and it contributes to chemoresistance of cervical cancer. MTDH could be utilized as a therapeutic target to overcome chemoresistance of cervical cancer.

Accumulating evidence indicates that aberrant expression of microRNAs is involved in tumorigenesis, tumor progression and response to therapy. MicroRNA-375 (miR-375) is an important cancer-associated RNA that is downregulated in multiple types of cancer. In the present study, the potential effects of and underlying molecular mechanism for miR-375 in esophageal cancer were investigated. The expression of miR-375 in paired esophageal squamous cell carcinoma (ESCC) and non-tumor tissues from 10 patients was quantified using the reverse transcription-quantitative polymerase chain reaction. The miR-375 levels in the ESCC cell line EC109 and a normal esophageal epithelial cell line, Het-1A, were also detected. The effect of miR-375 on ESCC cell growth and invasion was determined using Cell Counting kit-8, flow cytometry and invasion assays. A luciferase assay was conducted for target identification. The results of the present study revealed that miR-375 was downregulated in ESCC tumor tissue and EC109 cells compared with normal tissue and Het-1A cells (P<0.01). Overexpression of miR-375 inhibited EC109 cell growth and invasion, and induced cell cycle arrest. In addition, metadherin (MTDH) was demonstrated to be a direct target of miR-375 (P<0.01). The overexpression of miR-375 downregulated MTDH (P<0.01), cyclin D1 (P<0.05) and vascular endothelial growth factor (P<0.01) expression, while upregulating epithelial cadherin (P<0.01) expression, which may account for its effect on ESCC cell proliferation and invasion. The results of the present study suggest that the miR-375/MTDH axis represents a target for the treatment of ESCC.

Lung cancer is the third most frequent human malignant tumour and the leading cause of cancer-associated mortality worldwide. Emerging lines of evidence have demonstrated that microRNAs (miRNAs) are upregulated or downregulated in non-small cell lung cancer (NSCLC), and this phenomenon is involved in the regulation of various processes during tumorigenesis and progression, including tumour groWTh, apoptosis, cell invasion, and tumour metastasis. Therefore, understanding the molecular mechanism that associates abnormally expressed miRNAs with NSCLC formation and development may lead to the identification of novel diagnostic, and therapeutic targets for patients with NSCLC. miRNA-584 (miR-584) functions as a tumour suppressor in several types of cancer. However, the expression pattern, detailed biological function and underlying molecular mechanism of miR-584 in NSCLC remain unclear. Therefore, the present study detected the expression of miR-584 in NSCLC, investigated its role in NSCLC cells and determined its underlying molecular mechanism. In the current study, it was demonstrated that miR-584 was downregulated in NSCLC tissues and cell lines. Low miR-584 expression was correlated with tumour size, tumour node metastasis stage and distant metastasis. Overexpression of miR-584 inhibited cell proliferation and invasion in NSCLC. Additionally, metadherin was identified as a direct target gene of miR-584 in NSCLC as confirmed by a series of experiments. Moreover, upregulation of miR-584 was involved in the regulation of the phosphatase and tensin homolog/Akt serine/threonine kinase signalling pathway in NSCLC. Thus, miR-584 may serve as a tumor-suppressor, and the results of the present study provide a reference for future research into the potential mechanisms underlying NSCLC progression.

Metadherin (MTDH) overexpression in diverse cancer types has been linked to poor clinical outcomes, but definitive genetic proof of its contributions to cancer remains incomplete. In particular, the degree to which MTDH may contribute to malignant progression in vivo is lacking. Here, we report that MTDH is amplified frequently in human prostate cancers where its expression levels are tightly correlated with prostate cancer progression and poor disease-free survival. Furthermore, we show that genetic ablation of MTDH in the transgenic adenomcarcinoma of mouse prostate (TRAMP) transgenic mouse model of prostate cancer blocks malignant progression without causing defects in the normal development of the prostate. Germline deletion of Mtdh in TRAMP mice prolonged tumor latency, reduced tumor burden, arrested progression of prostate cancer at well-differentiated stages, and inhibited systemic metastasis to distant organs, thereby decreasing cancer-related mortality ∼10-fold. Consistent with these findings, direct silencing of Mtdh in prostate cancer cells decreased proliferation in vitro and tumor growth in vivo, supporting an epithelial cell-intrinsic role of MTDH in prostate cancer. Together, our findings establish a pivotal role for MTDH in prostate cancer progression and metastasis and define MTDH as a therapeutic target in this setting. Cancer Res; 74(18); 5336-47. ©2014 AACR.

Cell-free circular RNAs (circRNAs) stably and abundantly exist in body fluids. In this study we aimed to investigate the potential of urinary cell-free circRNAs as a novel class of noninvasive disease biomarkers for diagnosis of bladder cancer. Differentially expressed circRNAs from 10 normal and 10 bladder cancer urine samples were firstly detected by microarray. Hsa_circ_0137439 was then screened and validated in 30 normal and 116 bladder cancer samples. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of hsa_circ_0137439. The Kaplan-Meier method was used to evaluate the significance of hsa_circ_0137439 in the prognosis of bladder cancer. We found that hsa_circ_0137439 was significantly upregulated in bladder cancer samples. Moreover, increased expression of hsa_circ_0137439 was correlated with higher tumor stage, higher tumor grade, higher lymph node status, and history of muscle-invasive bladder cancer (MIBC). Also, urinary cell-free hsa_circ_0137439 could not only differentiate bladder cancer from normal controls but also distinguish MIBC from non-muscle-invasive bladder cancer (NMIBC). Additionally, hsa_circ_0137439 in urine supernatant could serve as an independent prognostic predicator of recurrence-free survival and overall survival for patients with bladder cancer. Cell assays showed that hsa_circ_0137439 knockdown contributed to the inhibition of cell proliferation and migration via hsa_circ_0137439/miR-142-5p/ MTDH axis. In conclusion, urinary cell-free hsa_circ_0137439 could be a promising biomarker for tumor diagnosis and prognostic assessment of bladder cancer patients.

OBJECTIVE

Gastric cancer is the third most frequent cause of cancer mortality worldwide. In Iran, it is one of the leading causes at the national level. Localized at chromosome 8q22, the human MTDH gene has been reported to be over-expressed in a spectrum of malignancies. However, since there is a lack of data concerning with expression in gastric cancer at the transcriptional level, in this study we evaluated MTDH expression in Iranian cases.

METHODS

Totally, thirty paired gastric samples were examined by quantitative real-time RT-PCR.

RESULTS

Although the mRNA expression was significantly elevated in 46.6% of the examined tumor tissues; its expression was low in others (36.6%). Moreover, there was only a marginal statistical difference between the MTDH gene expression of all tumor specimens compared to their paired non-tumor ones and no statistically significant association with the grades and types of the tumors.

CONCLUSIONS

Taken together, our results demonstrated that expression of MTDH at the transcriptional level may be increased in gastric cancer tissue samples but with considerable heterogeneity. Due to this, it may have the potential to be used as a target for diagnostic/therapeutic purposes only in a subset of patients.

MTDH (metadherin), an important oncogene that is widely overexpressed in various cancers, is a potential biomarker of tumor malignancy. Variants in MTDH have been associated with susceptibility to breast cancer. However, no studies assessing MTDH gene polymorphisms and their potential relationship to ovarian cancer susceptibility have been reported. Thus, we investigated the association of MTDH (-470G>A) polymorphism with ovarian cancer development in 145 ovarian cancer patients and 254 matched control subjects, using sequence analysis. We found that the MTDH (-470G>A) polymorphism was statistically correlated with ovarian cancer risk (under the additive genetic model, GG vs. GA vs AA, P = 0.042). Compared with genotypes containing the G allele (GG and GA), the AA genotype may decrease the risk of ovarian cancer (P = 0.0198, OR = 0.33, 95% CI [0.12∼0.78]). Compared with the G allele, the A allele is protective against ovarian cancer risk (P = 0.01756, OR = 0.66, 95% CI [0.46∼0.93]). Furthermore, a statistically significant association between the GG and GA+AA genotypes and the clinical stage was observed (P = 0.038). These data suggest that MTDH (-470G>A) could be a useful molecular marker for assessing ovarian cancer risk and for predicting ovarian cancer patient prognosis.

OBJECTIVE

Carcinoma of the bladder is the fifth most common cancer whose incidence continues to rise. MTDH/AEG-1 is associated with the initiation and progression of many cancers including breast, hepatocellular, ovarian, and colorectal carcinomas. However, the expression and functional importance of MTDH/AEG-1 in bladder cancer remains unknown. The present study was aimed at exploring the functional role of MTDH/AEG-1 in selected bladder cancer cell lines.

METHODS

The relative expression of MTDH/AEG-1 was assessed by real-time quantitative reverse transcription-polymerase chain reaction in several human bladder cancer cell lines as well as cancerous and benign bladder tissues. Then, expression of MTDH/AEG-1 in RT112 and 647V bladder cancer cell lines was knocked down by an RNA interference strategy. Cell viability and apoptosis were determined after treatment with specific interfering RNA. Potential effects of MTDG/AEG-1 specific interfering RNA on the cell cycle were investigated by flow cytometry. We also performed anchorage-independent growth and wound-healing assays to study MTDH/AEG-1 function.

RESULTS

Down-regulation of MTDH/AEG-1 did not significantly affect the cell cycle distribution but rather reduced cell viability via apoptosis, as evidenced by increased annexin V staining and caspase 3/7 activities as well as mitochondrial potential disruption. Of note, serum starvation did not exacerbate the effects of MTDH/AEG-1 knockdown. Furthermore, MTDH/AEG-1 down-regulation significantly decreased anchorage-independent growth and migration of bladder carcinoma cells.

CONCLUSIONS

Overexpression of MTDH/AEG-1 contributes to the neoplastic phenotype of bladder cancer cells by promoting survival, clonogenicity, and migration.

BACKGROUND

Trastuzumab resistance is almost inevitable in the management of human epidermal growth factor receptor (HER) 2 positive breast cancer, in which phosphatase and tensin homolog deleted from chromosome 10 (PTEN) loss is implicated. Since metadherin (MTDH) promotes malignant phenotype of breast cancer, we sought to define whether MTDH promotes trastuzumab resistance by decreasing PTEN expression through an NFκB-dependent pathway.

METHODS

The correlations between MTDH and PTEN expressions were analyzed both in HER2 positive breast cancer tissues and trastuzumab resistant SK-BR-3 (SK-BR-3/R) cells. Gene manipulations of MTDH and PTEN levels by knockdown or overexpression were utilized to elucidate molecular mechanisms of MTDH and PTEN implication in trastuzumab resistance. For in vivo studies, SK-BR-3 and SK-BR-3/R cells and modified derivatives were inoculated into nude mice alone or under trastuzumab exposure. Tumor volumes, histological examinations as well as Ki67 and PTEN expressions were revealed.

RESULTS

Elevated MTDH expression indicated poor clinical benefit, shortened progression free survival time, and was negatively correlated with PTEN level both in HER2 positive breast cancer patients and SK-BR-3/R cells. MTDH knockdown restored PTEN expression and trastuzumab sensitivity in SK-BR-3/R cells, while MTDH overexpression prevented SK-BR-3 cell death under trastuzumab exposure, probably through IκBα inhibition and nuclear translocation of p65 which subsequently decreased PTEN expression. Synergized effect of PTEN regulation were observed upon MTDH and p65 co-transfection. Forced PTEN expression in SK-BR-3/R cells restored trastuzumab sensitivity. Furthermore, decreased tumor volume and Ki67 level as well as increased PTEN expression were observed after MTDH knockdown in subcutaneous breast cancer xenografts from SK-BR-3/R cells, while the opposite effect were found in grafts from MTDH overexpressing SK-BR-3 cells.

CONCLUSIONS

MTDH overexpression confers trastuzumab resistance in HER2 positive breast cancer. MTDH mediates trastuzumab resistance, at least in part, by PTEN inhibition through an NFκB-dependent pathway, which may be utilized as a promising therapeutic target for HER2 positive breast cancer.

Ductal carcinoma in situ (DCIS) accounts for approximately 20% of mammographically detected breast cancers. Although DCIS is generally highly curable, some women with DCIS will develop life-threatening invasive breast cancer, but the determinants of progression to infiltrating ductal cancer (IDC) are largely unknown. In the current study, we used multiplex ligation-dependent probe amplification (MLPA), a multiplex PCR-based test, to compare copy numbers of 21 breast cancer related genes between laser-microdissected DCIS and adjacent IDC lesions in 39 patients. Genes included in this study were ESR1, EGFR, FGFR1, ADAM9, IKBKB, PRDM14, MTDH, MYC, CCND1, EMSY, CDH1, TRAF4, CPD, MED1, HER2, CDC6, TOP2A, MAPT, BIRC5, CCNE1 and AURKA.There were no significant differences in copy number for the 21 genes between DCIS and adjacent IDC. Low/intermediate-grade DCIS showed on average 6 gains/amplifications versus 8 in high-grade DCIS (p=0.158). Furthermore, alterations of AURKA and CCNE1 were exclusively found in high-grade DCIS, and HER2, PRDM14 and EMSY amplification was more frequent in high-grade DCIS than in low/intermediate-grade DCIS. In contrast, the average number of alterations in low/intermediate and high-grade IDC was similar, and although EGFR alterations were exclusively found in high-grade IDC compared to low/intermediate-grade IDC, there were generally fewer differences between low/intermediate-grade and high-grade IDC than between low/intermediate-grade and high-grade DCIS.In conclusion, there were no significant differences in copy number for 21 breast cancer related genes between DCIS and adjacent IDC, indicating that DCIS is genetically as advanced as its invasive counterpart. However, high-grade DCIS showed more copy number changes than low/intermediate-grade DCIS with specifically involved genes, supporting a model in which different histological grades of DCIS are associated with distinct genomic changes that progress to IDC in different routes. These high-grade DCIS specific genes may be potential targets for treatment and/or predict progression.

MicroRNAs have been integrated into tumorigenic programs as either oncogenes or tumor suppressor genes. The miR-630 was reported to be deregulated and involved in tumor progression of several human malignancies. However, its expression regulation shows diversity in different kinds of cancers and its potential roles remain greatly elusive. Herein, we demonstrate that miR-630 is significantly suppressed in human breast cancer specimens, as well as in various breast cancer cell lines. In aggressive MDA-MB-231-luc and BT549 breast cancer cells, ectopic expression of miR-630 strongly inhibits cell motility and invasive capacity in vitro. Moreover, lentivirus delivered miR-630 bestows MDA-MB-231-luc cells with the ability to suppress cell colony formation in vitro and pulmonary metastasis in vivo. Further studies identify metadherin (MTDH) as a direct target gene of miR-630. Functional studies shows that MTDH contributes to miR-630-endowed effects including cell migration and invasion as well as colony formation in vitro. Taken together, these findings highlight an important role for miR-630 in the regulation of metastatic potential of breast cancer and suggest a potential application of miR-630 in breast cancer treatment.

We describe a new imaging method for detecting prostate cancer, whether localized or disseminated and metastatic to soft tissues and bone. The method relies on the use of imaging reporter genes under the control of the promoter of AEG-1 (MTDH), which is selectively active only in malignant cells. Through a systemic, nanoparticle-based delivery of the imaging construct, lesions can be identified through bioluminescence imaging and single-photon emission computed tomography in the PC3-ML murine model of prostate cancer at high sensitivity. This approach is applicable for the detection of prostate cancer metastases, including bone lesions for which there is no current reliable agent for noninvasive clinical imaging. Furthermore, the approach compares favorably with accepted and emerging clinical standards, including PET with [(18)F]fluorodeoxyglucose and [(18)F]sodium fluoride. Our results offer a preclinical proof of concept that rationalizes clinical evaluation in patients with advanced prostate cancer.

Astrocyte-elevated gene-1 (AEG-1/MTDH/LYRIC) is a potent oncogene that regulates key cellular processes underlying disease of the central nervous system (CNS). From its involvement in human immunodeficiency virus (HIV)-1 infection to its role in neurodegenerative disease and malignant brain tumors, AEG-1/MTDH/LYRIC facilitates cellular survival and proliferation through the control of a multitude of molecular signaling cascades. AEG-1/MTDH/LYRIC induction by HIV-1 and TNF highlights its importance in viral infection, and its incorporation into viral vesicles supports its potential role in active viral replication. Overexpression of AEG-1/MTDH/LYRIC in the brains of Huntington's disease patients suggests its function in neurodegenerative disease, and its association with genetic polymorphisms in large genome-wide association studies of migraine patients suggests a possible role in the pathogenesis of migraine headaches. In the field of cancer, AEG-1/MTDH/LYRIC promotes angiogenesis, migration, invasion, and enhanced tumor metabolism through key oncogenic signaling cascades. In response to external stress cues and cellular mechanisms to inhibit further growth, AEG-1/MTDH/LYRIC activates pathways that bypass cell checkpoints and potentiates signals to enhance survival and tumorigenesis. As an oncogene that promotes aberrant cellular processes within the CNS, AEG-1/MTDH/LYRIC represents an important therapeutic target for the treatment of neurological disease.

BACKGROUND

About 70% of human breast cancers express estrogen receptor α (ERα) and in this kind of breast cancer estrogen plays an important role. Estrogen independent growth has been reported to promote resistance to one of the selective estrogen receptor modulators (SERMs) tamoxifen which is clinically the first line treatment for patients with ERα-positive breast cancer. The resistance of tamoxifen is a major problem in the clinical management of breast cancer.

METHODS

We used MCF-7 cells with ectopic expression of MDTH in this study. MTT, clone formation and tumor formation in nude mice methods were utilized to confirm the role of MTDH in estrogen-independent growth and tamoxifen resistance. Flow cytometry, western blot and siRNA were used to study the detailed mechanisms.

RESULTS

We found that MTDH could mediate estrogen-independent growth and induce resistance to tamoxifen in ERα-positive breast cancer cells. MTDH could reduce the expression of PTEN, up-regulate AKT and BCL2 and inhibit the apoptosis induced by tamoxifen.

CONCLUSIONS

Our study indicated that MTDH was a candidate marker to predict the clinical efficacy of tamoxifen and targeting MTDH would overcome the resistance to tamoxifen in breast cancer cells.

OBJECTIVE

MicroRNAs (miRNAs) are small, non-coding RNAs that have been increasingly shown important roles in various classes of cancers. However, miR-1269 has not been comprehensively studied in hepatocellular carcinoma (HCC). Thus, the purpose of the study was to evaluate the relationship between the expression of miR-1269 and clinicopathological parameters in HCC patients, and to predict its potential target genes.

METHODS

Total RNA was extracted from 95 pairs of HCC and matching adjacent non-cancerous tissues. The level of miR-1269 expression was detected by using quantitative real-time RT-PCR and calculated with the 2(-ΔCq) method. Eighteen online biological databases were used for targets prediction.

RESULTS

MiR-1269 expression was up-regulated in HCC tissues (1.9264±0.7160) compared to their non-tumor livers (1.5518±0.7273, P < 0.001). Level of miR-1269 was positively correlated to tumor nodes (r = 0.206, P = 0.046), metastasis (r = 0.203, P = 0.049), portal vein tumor embolus (r = 0.247, P = 0.016), vaso-invasion (r = 0.273, P = 0.008), tumor capsular infiltration (r = 0.407, P < 0.001) and expression of MTDH (r = 0.211, P = 0.005). Finally, 7 databases could be applied for the target prediction successfully. There were 9 targeted genes which had been shown concurrently by at least 4 databases: AGAP1, AGK, BPTF, C16orf74, DACT1, LIX1L, RBMS3, ZNF706 and BMPER.

CONCLUSIONS

MiR-1269 may be possibly involved in the tumorigenesis and progress of HCC. MiR-1269 could also act as a potential biomarker for the prognosis prediction for HCC.

Metformin, a drug approved for diabetes type II treatment, has been associated with a reduction in the incidence of breast cancer and metastasis and increased survival in diabetic breast cancer patients. High levels of miR-26a expression have been proposed as one of the possible mechanisms for this effect; likewise, this miRNA has also been associated with survival/apoptosis processes in breast cancer. Our aim was to evaluate if miR-26a and some of its targets could mediate the effect of metformin in breast cancer. The viability of MDA-MB-231, MDA-MB-468, and MCF-7 breast cancer cell lines was evaluated with an MTT assay after ectopic overexpression and/or downregulation of miR-26a. Similarly, the expression levels of the miR-26a targets CASP3, CCNE2, ABL2, APAF1, XIAP, BCL-2, PTEN, p53, E2F3, CDC25A, BCL2L1, MCL-1, EZH2, and MTDH were assessed by quantitative polymerase chain reaction (PCR). The effect of metformin treatment on breast cancer cell viability and miR-26a, BCL-2, PTEN, MCL-1, EZH2, and MTDH modulation were evaluated. Wound healing experiments were performed to analyze the effect of miR-26a and metformin treatment on cell migration. MiR-26a overexpression resulted in a reduction in cell viability that was partially recovered by inhibiting it. E2F3, MCL-1, EZH2, MTDH, and PTEN were downregulated by miR-26a and the PTEN (phosphatase and tensin homolog) protein was also reduced after miR-26a overexpression. Metformin treatment reduced breast cancer cell viability, increased miR-26a expression, and led to a reduction in BCL-2, EZH2, and PTEN expression. miR-26a inhibition partly prevents the metformin viability effect and the PTEN and EZH2 expression reduction. Our results indicate that metformin effectively reduces breast cancer cell viability and suggests that the effects of the drug are mediated by an increase in miR-26a expression and a reduction of its targets, PTEN and EHZ2 Thus, the use of metformin in breast cancer treatment constitutes a promising potential breast cancer therapy.

Cancer initiation and progression is characterized by (epi)genetic aberrations. However, little is known about the changes that occur during breast cancer metastasis. In the present study, multiplex ligation-dependent probe amplification was used to compare copy numbers of 21 established oncogenes and tumor suppressor genes between 55 primary breast cancer samples and corresponding distant metastases. Distant breast cancer metastases generally showed similar gene copy number aberrations compared to their corresponding primary tumors. The few genes that showed differences between primary tumor and metastasis (PRDM14, MED1, CCNE1, TRAF4, MTDH, CDH1) have been implicated in the development of therapy resistance.

A new architecture has been designed by the conjugation of [(18)F]2-fluoro-2-deoxy-D-glucose ((18)F-FDG), gold nanoparticles (AuNPs), and anti-metadherin (Anti-MTDH) antibody which is specific to the metadherin (MTDH) over-expressed on the surface of breast cancer cells. Mannose triflate molecule is used as a precursor for synthesis of (18)F-FDG by nucleophilic fluorination. For the conjugation of (18)F-FDG and AuNPs, cysteamine was first bound to mannose triflate (Man-CA) before synthesizing of (18)F-FDG which has cysteamine sides ((18)FDG-CA). Then, (18)FDG-CA was reacted with HAuCl(4) to obtain AuNPs and with NaBH(4) for reduction of AuNPs. At the end of this procedure, AuNPs were conjugated to (18)F-FDG via disulphide bonds ((18)FDG-AuNP). For the conjugation of Anti-MTDH, 1,1'-carbonyl diimidazol (CDI) was bound to the (18)FDG-AuNP, and Anti-MTDH was conjugated via CDI ((18)FDG-AuNP-Anti-MTDH). This procedure was also performed by using Na(19)F to obtain non-radioactive conjugates ((19)FDG-AuNP-Anti-MTDH). Scanning electron microscopy (SEM) images demonstrated that synthesized particles were in nano sizes. (18)FDG-AuNP-Anti-MTDH conjugate was characterized and used as a model probe containing both radioactive and optical labels together as well as the biological target. The (18)FDG-AuNP-Anti-MTDH conjugate was applied to MCF7 breast cancer cell line and apoptotic cell ratio was found to be increasing from 2% to 20% following the treatment. Hence, these results have promised an important application potential of this conjugate in cancer research.