Poly(vinyl alcohol)-pyrene-anti-metadherin (PVA-Py-(Anti-MTDH)), a novel antibody based water soluble probe containing both fluorescent and target sites in the structure for in vitro imaging of breast cancer cells is reported here. Since breast cancer cells have an excess of MDTH protein expressed on the surface, a PVA-Py prepared by "Click chemistry" approach is targeted by Anti-MTDH antibody and applied to the MCF-7 cell line. After characterization, the designed architecture was evaluated in terms of cell incorporation efficiency and compared with a non-targeted structure (PVA-Py). Atomic force microscopy (AFM) and fluorescence microscopy images of cells after incubation of the probe molecules were also obtained to monitor the interaction of the probes with the cancerous cells.

(1) Background: Tumor hypoxia leads to metastasis and certain immune responses, and interferes with normal biological functions. It also affects glucose intake, down-regulates oxidative phosphorylation, and inhibits fatty-acid desaturation regulated by hypoxia-inducible factor 1α (HIF-1α). Although tumor hypoxia has been found to promote tumor metastasis, the roles of HIF-1α-regulated genes and their application are not completely integrated in clinical practice. (2) Methods: We examined the correlation between HIF-1α, metadherin (MTDH), and interleukin (IL)-10 mRNA expression, as well as their expression patterns in the prognosis of breast cancer using the Gene Expression Profiling Interactive Analysis (GEPIA) databases via a web interface; tissue microarrays (TMAs) were stained for MTDH and IL-10 protein expression using immunohistochemistry. (3) Results: HIF-1α, MTDH, and IL-10 mRNA expression are highly correlated and strongly associated with poor prognosis. MTDH and IL-10 protein expression of breast cancer patients usually harbored negative estrogen receptor (ER) or progesterone receptor (PR) status, and late-stage tumors have higher IL-10 expression. With regard to MTDH and IL-10 protein expression status for using univariate and multivariate analysis, the results showed that the protein expression of MTDH and IL-10 in ER-negative or PR-negative breast cancer patients have the worse prognosis. (4) Conclusions: we propose a new insight into hypoxia tumors in the metabolism and immune evidence for breast cancer therapy.

Keywords: IL-10; MTDH; breast cancer; hypoxia; survival.

Astrocyte-elevated gene-1 (AEG-1), also known as metadherin (MTDH) and lysine-rich CEACAM1 coisolated (LYRIC), has emerged as an important oncogene that regulates key cellular processes including apoptosis, migration, invasion, proliferation, and differentiation. It was reported that AEG-1 enhanced breast cancer cells migration in a NF-κB-dependent manner. Also, AEG-1 contributed cell proliferation through the PI3K-Akt/cyclin pathway. Besides, AEG-1 is implicated in diverse physiological and pathological diseases of the central nervous system (CNS), such as brain tumors, neuroblastomas, neurodegeneration, and neuronal development. However, the role of AEG-1 in the process of peripheral nervous regeneration after injury remains virtually unknown. In this study, we investigated the spatiotemporal expression of AEG-1 in a rat sciatic nerve crush model. At its peak expression, AEG-1 was expressed mainly in Schwann cells of the distal sciatic nerve segment from injury, but had few colocalizations in axons. Besides, the peak expression of AEG-1 was in parallel with proliferating cell nuclear antigen (PCNA). In vitro, we detected the increased expression of AEG-1 during the process of tumor necrosis factor α (TNF-α)-induced Schwann cell proliferation. Meanwhile, interference of AEG-1 inhibited both proliferation and migration of Schwann cells. In conclusion, we speculated that AEG-1 is involved in biochemical and physiological responses after sciatic nerve crush (SNC).

Neuroendocrine tumors respond poorly to radiation and conventional chemotherapy, hence surgical removal of the neoplastic tissue is still the most effective way of treatment. In an attempt to find new therapeutic plant extracts of Christia vespertilionis (CV) their antitumor potential in human medullary thyroid carcinoma (MTC) and human small intestinal neuroendocrine tumor (SI-NET) cell lines were tested. Proliferation and viability were analyzed using cell counting and WST-1 assay. Apoptosis was determined by microscopy, luminescence assays for caspases 3/7, and expression studies of apoptosis-related genes. CV extracts showed antiproliferative and proapoptotic effects in all MTC and SI-NET cell lines, whereby high growth inhibition was observed by treatment with the ethylacetate-extracts (CV-45) in tumor cell lines but not in normal human fibroblasts. Furthermore CV-45 treatment resulted in alterations of gene expression of PDCD5, MTDH and TNFRSF10b in MTC as well as in SI-NET cells. The results indicate that Christia vespertilionis could serve as an anticancer therapeutic for treatment of neuroendocrine tumors.

MicroRNAs (miRNAs/miRs) serve important roles in regulating gene expression by directly binding to the 3'‑untranslated regions of target genes. Multiple miRNAs are dysregulated in retinoblastoma (RB) and their dysregulation is closely related to RB malignancy. Therefore, exploring the detailed roles of miRNAs in RB is valuable to facilitate the development of effective therapeutic targets for patients with this disease. miRNA‑874‑3p (miR‑874) has been recently reported to be downregulated in several types of human cancer and serves an essential role in cancer progression. However, the expression pattern and detailed roles of miR‑874 in RB, as well as the underlying molecular mechanisms in RB, have not been clearly elucidated. Therefore, this study detected miR‑874 expression in RB tissues and cell lines. The biological roles of miR‑874 in RB were determined and the underlying mechanisms of its actions in RB cells were also examined. This study revealed that miR‑874 expression was aberrantly underexpressed in RB tissues and cell lines. However, returning miR‑874 expression restricted the proliferative and invasive abilities of RB cells. In terms of the underlying mechanism, metadherin (MTDH) was validated as a direct target gene of miR‑874 in RB cells. MTDH inhibition could imitate the inhibitory roles of miR‑874 overexpression in RB cells. Furthermore, forced MTDH expression partially reversed the suppressive effects of miR‑874 on RB cells. In conclusion, this study revealed that miR‑874 may inhibit RB progression by directly targeting MTDH. Restoration of miR‑874 expression may be a novel strategy for preventing the rapid growth and metastasis of RB cells.

Macrophages in the intestinal mucosa can rapidly engage Toll-like receptor (TLR)-mediated inflammatory responses to defect against pathogen invasion, but these same innate immune responses can also drive the induction of colitis. Our previous research revealed that metadherin (MTDH), is overexpressed in multiple cancers and plays vital roles in tumor progression. However, the role of MTDH in intestinal inflammation is largely unknown. In this study, we found the MTDH expression in colonic lamina propria (CLP) macrophages was positively correlated with inflammatory colitis severity. MTDH -/- mice were protected against the symptoms of DSS-induced colitis, however, adoptive transfer of MTDH wild-type (WT) monocytes partially restored the susceptibility of MTDH -/- mice to DSS-induced colitis. TLR stimulation was sufficient to induce the expression of MTDH, whereas the absence of MTDH was sufficient to suppress TLR-induced production of inflammatory cytokines by macrophages. From a mechanistic perspective, MTDH recruited TRAF6 to TAK1, leading to TRAF6-mediated TAK1 K63 ubiquitination and phosphorylation, ultimately facilitating TLR-induced NF-κB and MAPK signaling. Taken together, our results indicate that MTDH contributes to colitis development by promoting TLR induced proinflammatory cytokines production in CLP macrophages and might represent a potential therapeutic approach for intestine inflammation intervention.

Various literatures have demonstrated that overexpression of Metadherin (MTDH) is correlated with tumor metastasis and it can predict poor survival outcomes in female reproduction malignancies. In order to enhance the statistical power and reach a recognized conclusion, we conducted a systematic review and meta-analysis to thoroughly investigate the association of MTDH expression with tumor metastasis and survival outcomes following PRISMA guidelines. Odds ratios (ORs) and hazard ratios (HRs) were used to demonstrate the impact of MTDH on tumor metastasis and prognosis respectively. Data were pooled with appropriate effects model on STATA12.0. Our results indicated that high MTDH expression is significantly correlated with higher mortality for breast, ovarian and cervical cancer. High immunohistochemical expression of MTDH is remarkably associated with shorter disease-free survival (DFS) in breast cancer but not in ovarian cancer. The pooled results suggested that high level of MTDH significantly predicted distant metastasis and lymph node metastasis in breast cancer. Strong associations were observed between MTDH expression and lymph node metastasis in ovarian and cervical cancer. In conclusion, MTDH might be a novel biomarker which can effectively reflect metastasis status and prognosis of breast cancer. However, its application in clinical practice needs more prospective studies with large samples.

Resectable esophageal adenocarcinoma (EAC) patients often receive chemoradiation followed by surgery. However, most patients experience recurrences. Overexpression of MTDH, an oncoprotein with multiple functions, has been found to be associated with poor prognosis in breast cancer, glioblastoma, melanoma and various gastrointestinal malignancies, but not in EAC. We sought to establish its role in resistant EAC (post-treatment residual EAC). MTDH was assessed by immunohistochemistry in resected EAC, and results were correlated with clinical outcomes. MTDH expression was detectable in 72.5% (50/69) of patients, while expression levels were high (positive) in 50.7% (35/69). Of 69 patients analyzed, 25 had no relapse and 44 patients had a relapse (8 with local-regional and 36 with distant). The median follow-up duration was 3 years (0.4-11.6). The median overall survival was not associated with MTDH status (2.79 years for MTDH-negative and 3.60 years for MTDH-positive patients, p = 0.121). In addition, MTDH was not associated with either the type of relapse (local or distant), baseline clinical stage, tumor grade, presence of signet ring cells, surgical (yp) stage, percentage of residual EAC or presence of lymphovascular invasion. Our data reveal that MTDH is not a prognostic biomarker in resistant EAC after trimodality therapy.

Metadherin (MTDH), also known as astrocyte elevated gene-1 (AEG-1), is an oncoprotein closely related to the development of breast cancer. However, few studies have been done on the expression and clinical significance of MTDH in human epidermal growth factor receptor-2 (HER-2) positive breast cancer patients.This study aimed to investigate the expression of MTDH in locally advanced HER-2 positive breast cancer, and evaluate the clinical significance of MTDH in predicting the prognosis of patients with HER-2 positive advanced breast cancer who received the neoadjuvant chemotherapy plus trastuzumab.In 144 HER-2 positive breast cancer tissues, 79 cases showed high expression of MTDH and 65 cases showed low expression. The expression of MTDH in locally advanced HER-2 positive breast cancer tissues was correlated with TNM stage, lymph node metastasis, Miller-Payne (MP) grade, and pathologic complete response (pCR) status (P < .05), but was not correlated with patient age, estrogen receptor (ER) expression level, progesterone receptor (PR) expression level, and Ki-67 expression level (P > .05). Kaplan-Meier univariate analysis revealed a negative correlation between MTDH expression and the disease-free survival (DFS) and overall survival (OS) in the post-operative patients with locally advanced HER-2 positive breast cancer (log rank test: P < .001). By using the COX proportional hazard regression model, it was found that MTDH expression, TNM stage, lymph node metastasis, and Ki-67 expression were closely related to DFS in patients. The hazard ratio (HR) of high MTDH expression was 1.816 (95% CI: 1.165-2.829). In addition, MTDH expression, TNM stage, and lymph node metastasis were also closely related to the OS of patient. The HR of the high expression of MTDH was 2.512 (95% CI: 1.472-4.286). The expression of MTDH in tumor tissues of patients with HER2-positive locally advanced breast cancer was significantly elevated, which was related to the poor pathological features.High MTDH expression was closely correlated with poor prognosis of patients and was an important factor affecting tumor progression.

Astrocyte elevated gene-1 (AEG-1) and E-cadherin are associated with tumorigenesis and progression. The aim of this study is to investigate the expression of AEG-1 and E-cadherin in human gallbladder cancer (GBC) and explore their clinical and pathological significance. The expression of AEG-1 and E-cadherin protein were detected in 71 cases of human GBC and 22 cases of tumor-adjacent tissue by the immunohistochemical method. Our results demonstrate that the positive expression (high expression) rate of AEG-1 was 62.0% in human GBC which was higher than that in tumor-adjacent tissues (13.6%), P<0.001. The positive expression of AEG-1 protein was correlated with tumor TNM classification, histologic grade, and lymph node metastasis (P=0.037, P=0.033 and P=0.020, respectively). The positive expression rate of E-cadherin was 40.8% in GBC, which was lower than that in tumor-adjacent tissues (77.3%), P=0.003. Negative expression (Low expression) of E-Cadherin was significantly related with tumor TNM classification, histologic grade and lymphatic metastasis (P=0.028, P=0.003 and P=0.040, respectively). The expression of AEG-1 was negatively correlated with the expression of E-Cadherin (r=0.530, P<0.001). The log-rank test statistical analysis suggested that patients with positive expression of AEG-1 or negative expression of E-Cadherin protein had shorter overall survival time. Cox multivariate analysis showed that tumor TNM classification, histologic grade and lymphatic metastasis, AEG-1 and E-cadherin expression were independent factors for prognosis of GBC (P=0.013, P=0.019, P=0.001, P=0.011 and P=0.025 respectively). In conclusion, positive expression of AEG-1 and negative expression of E-Cadherin are markedly correlated with tumor TNM classification, histologic grade and lymphatic metastasis. The expression of AEG-1 was negatively correlated with the expression of E-Cadherin. Cox multivariate analysis showed that tumor TNM classification, histologic grade and lymphatic metastasis, positive expression of AEG-1 and negative expression of E-Cadherin were risk factors for prognosis of GBC. Detection of AEG-1 and E-Cadherin may be helpful to evaluate prognosis and infiltrative capability of gallbladder carcinoma.

Adult neurogenesis, the lifelong production of new neurons in the adult brain, is under complex genetic control but many of the genes involved remain to be identified. In this study, we have integrated publicly available gene expression data from the BXD and CXB recombinant inbred mouse lines to discover genes co-expressed in the adult hippocampus with Nestin, a common marker of the neural precursor cell population. In addition, we incorporated spatial expression information to restrict candidates to genes with high differential gene expression in the hippocampal dentate gyrus. Incorporating data from curated protein-protein interaction databases revealed interactions between our candidate genes and those already known to be involved in adult neurogenesis. Enrichment analysis suggested a link to the Wnt/β-catenin pathway, known to be involved in adult neurogenesis. In particular, our candidates were enriched in targets of Lef1, a modulator of the Wnt pathway. In conclusion, our combination of bioinformatics approaches identified six novel candidate genes involved in adult neurogenesis; Amer3, Eya3, Mtdh, Nr4a3, Polr2a, and Tbkbp1. Further, we propose a role for Lef1 transcriptional control in the regulation of adult hippocampal precursor cell proliferation.

Since its initial cloning in 2002, a plethora of studies in a vast number of cancer indications, has strongly established AEG-1 as a bona fide oncogene. In all types of cancer cells, overexpression and knockdown studies have demonstrated that AEG-1 performs a seminal role in regulating proliferation, invasion, angiogenesis, metastasis and chemoresistance, the defining cancer hallmarks, by a variety of mechanisms, including protein-protein interactions activating diverse oncogenic pathways, RNA-binding promoting translation and regulation of inflammation, lipid metabolism and tumor microenvironment. These findings have been strongly buttressed by demonstration of increased tumorigenesis in tissue-specific AEG-1 transgenic mouse models, and profound resistance of multiple types of cancer development and progression in total and conditional AEG-1 knockout mouse models. Additionally, clinicopathologic correlations of AEG-1 expression in a diverse array of cancers establishing AEG-1 as an independent biomarker for highly aggressive, chemoresistance metastatic disease with poor prognosis have provided a solid foundation to the mechanistic and mouse model studies. In this review a comprehensive analysis of the current and up-to-date literature is provided to delineate the clinical significance of AEG-1 in cancer highlighting the commonality of the findings and the discrepancies and discussing the implications of these observations.

Keywords: AEG-1; MTDH; biomarker; cancer.

BACKGROUND

Drug resistance of paclitaxel (TAX), the first-line chemotherapy drug for breast cancer, was reported to develop in 90% of patients with breast cancer, especially metastatic breast cancer. Investigating the mechanism of TAX resistance of breast cancer cells and developing the strategy improving its therapeutic efficiency are crucial to breast cancer cure.

RESULTS

We here report an elegant nanoparticle (NP)-based technique that realizes efficient breast cancer treatment of TAX. Using lentiviral vector-mediated gene knockdown, we first demonstrated that TAX therapeutic efficiency was closely correlated with metadherin (MTDH) gene expression in breast cancer cell lines. This finding was also supported by efficacy of TAX treatment in breast cancer patients from our clinical studies. Specifically, TAX treatment became more effective when MTDH expression was decreased in MCF-7 cancer cells by the blocking nuclear factor-kappa B (NF-κB) pathway. Based on these findings, we subsequently synthesized a polymeric NP that could co-deliver MTDH-small interfering RNA (MTDH-siRNA) and TAX into the breast cancer tumors in tumor-bearing mice. The NPs were composed of a cationic copolymer, which wrapped TAX in the inside and adsorbed the negatively charged siRNA on their surface with high drug-loading efficiency and good stability.

CONCLUSIONS

NP-based co-delivery approach can effectively knock down the MTDH gene both in vitro and in vivo, which dramatically inhibits breast tumor growth, achieving effective TAX chemotherapy treatment without overt side effects. This study provides a potential therapeutic strategy for the treatment of a wide range of solid tumors highly expressing MTDH.

Glioblastoma multiforme is a common malignant brain tumor that portends extremely poor patient survival. Recent studies reveal that glioma stem-like cells (GSC) are responsible for glioblastoma multiforme escape from chemo-radiotherapy and mediators of tumor relapse. Previous studies suggest that AEG-1 (MTDH), an oncogene upregulated in most types of cancers, including glioblastoma multiforme, plays a focal role linking multiple signaling pathways in tumorigenesis. We now report a crucial role of AEG-1 in glioma stem cell biology. Primary glioblastoma multiforme cells were isolated from tumor specimens and cultured as neurospheres. Using the surface marker CD133, negative and positive cells were separated as nonstem and stem populations by cell sorting. Tissue samples and low passage cells were characterized and compared with normal controls. Functional biological assays were performed to measure stemness, self-renewal, differentiation, adhesion, protein-protein interactions, and cell signaling. AEG-1 was upregulated in all glioblastoma multiforme neurospheres compared with normal neural stem cells. Expression of AEG-1 was strongly associated with stem cell markers CD133 and SOX2. AEG-1 facilitated β-catenin translocation into the nucleus by forming a complex with LEF1 and β-catenin, subsequently activating Wnt signaling downstream genes. Through an AEG-1/Akt/GSK3β signaling axis, AEG-1 controlled phosphorylation levels of β-catenin that stabilized the protein.

This study discovers a previously unrecognized role of AEG-1 in GSC biology and supports the significance of this gene as a potential therapeutic target for glioblastoma multiforme. Mol Cancer Res; 15(2); 225-33. ©2016 AACR.

MicroRNAs (miRS) are a class of small non-coding RNAs which perform a crucial function in posttranscriptional gene regulation. Dysregulation of this microRNAs are associated with many types of cancer progression. In tumorigenesis, downregulated microRNAs might function as tumour suppressor by repressing onco- genes, whereas overexpressed miRs might function as oncogenes by suppressing tumour suppressor. Similarly, Metadherin (also known AEG-1/ LYRIC), is an oncogene, whose levels are found to be very high in various cancers and plays a crucial role in proliferation of cells and invasion. Our review focuses on the study which shows alteration of microRNA expression profile and suppression of carcinogenesis when MTDH/AEG-1 is targeted. It summarises about the studies where downregulation and upregulation AEG-1 and microRNAs respectively, alter the biological functions of the cell, such as proliferation and apoptosis. Studies have reported that AEG-1 can be direct or indirect target of microRNA which could provide a new-insight to know the underlying molecular mechanism and might contribute to the progress of new therapeutic strategies for the disease.

Keywords: AEG-1/MTDH/LYRIC; CRC; Colorectal cancer; biomarker; microRNA; oncogene.

SND1 is a multifunctional oncoprotein overexpressed in breast cancer. Binding of MTDH to SND1 results in the stabilization of SND1 and is important in the initiation and progression of breast cancer. Disruption of such interaction is a potential therapeutics for breast cancer. SN1/2 domain of SND1 was used as bait in a phage display screening to identify a 12-amino acid peptide 4-2. The activity of peptide 4-2 was evaluated by ELISA, co-immunoprecipitation, MTS, Western blot and xenograft mouse model. Peptide 4-2 could disrupt SND1-MTDH interaction. Cell penetrating derivative of peptide 4-2 (CPP-4-2) could penetrate and kill breast cancer cells by disrupting SND1-MTDH interaction and degrading SND1. Tryptophan 10 (W10) of peptide 4-2 was essential in mediating cytotoxicity, SND1 interaction, SND1-MTDH disruption and SND1 degradation. CPP-4-2 could inhibit the growth of breast cancer in xenograft mouse model. The SND1-interacting peptide 4-2 could kill breast cancer cells both in vitro and in vivo by interacting with SND1, disrupting SND1-MTDH interaction and inducing SND1 degradation. W10 was an essential amino acid in the activity of peptide 4-2.

Primary or acquired resistant mechanisms prevent the employment of individualized therapy with target drugs like the mTOR inhibitor everolimus (EVE) in hepatocellular carcinoma (HCC). The current study evaluated the effect of 1,25(OH)₂Vitamin D (VitD) treatment on EVE sensitivity in established models of HCC cell lines resistant to everolimus (EveR). DNA content and colony formation assays, which measure the proliferative index, revealed that VitD pre-treatment re-sensitizes EveR cells to EVE treatment. The evaluation of epithelial and mesenchymal markers by western blot and immunofluorescence showed that VitD restored an epithelial phenotype in EveR cells, in which prolonged EVE treatment induced transition to mesenchymal phenotype. Moreover, VitD treatment prompted hepatic miRNAs regulation, evaluated by liver miRNA finder qPCR array. In particular, miR-375 expression was up-regulated by VitD in EveR cells, in which miR-375 was down-regulated compared to parental cells, with consequent inhibition of oncogenes involved in drug resistance and epithelial-mesenchymal transition (EMT) such as MTDH, YAP-1 and c-MYC. In conclusion, the results of the current study demonstrated that VitD can re-sensitize HCC cells resistant to EVE treatment triggering miR-375 up-regulation and consequently down-regulating several oncogenes responsible of EMT and drug resistance.

Alternative splicing is a major contributor to transcriptome and proteome diversity in eukaryotes. Comparing to normal samples, about 30% more alternative splicing events were recently identified in 32 cancer types included in The Cancer Genome Atlas database. Some alternative splicing isoforms and their encoded proteins contribute to specific cancer hallmarks. In this review, we will discuss recent progress regarding the contributions of alternative splicing to breast cancer metastasis. We plan to dissect the role of MTDH, CD44 and their interaction with other mRNA splicing factors. We believe an in-depth understanding of the mechanism underlying the contribution of splicing to breast cancer metastasis will provide novel strategies to the management of breast cancer.

Purpose: DARS antisense RNA 1 (DARS-AS1) is a long non-coding RNA that has been validated as a critical regulator in several human cancer types. Our study aimed to determine the expression profile of DARS-AS1 in prostate cancer (PCa) tissues and cell lines. Functional experiments were conducted to explore the detailed roles of DARS-AS1 in regulating PCa carcinogenesis. Furthermore, the detailed mechanisms by which DARS-AS1 regulates the oncogenicity of PCa cells were uncovered.

Methods: Reverse transcription quantitative polymerase chain reaction was performed to analyze DARS-AS1 expression in PCa tissues and cell lines. Cell Counting Kit-8 assays, flow cytometry analyses, Transwell assays, and tumor xenograft experiments were conducted to determine the regulatory effects of DARS-AS1 knockdown on the malignant phenotype of PCa cells. Bioinformatics analysis was performed to identify putative microRNAs (miRNAs) targeting DARS-AS1, and the direct interaction between DARS-AS1 and miR-628-5p was verified using RNA immunoprecipitation and luciferase reporter assays.

Results: DARS-AS1 was highly expressed in PCa tissues and cell lines. In vitro functional experiments demonstrated that DARS-AS1 depletion suppressed PCa cell proliferation, promoted cell apoptosis, and restricted cell migration and invasion. In vivo studies revealed that the downregulation of DARS-AS1 inhibited PCa tumor growth in nude mice. Mechanistic investigation verified that DARS-AS1 functioned as an endogenous miR-628-5p sponge in PCa cells and consequently promoted the expression of metadherin (MTDH). Furthermore, the involvement of miR-628-5p/MTDH axis in DARS-AS1-mediated regulatory actions in PCa cells was verified using rescue experiments.

Conclusion: DARS-AS1 functioned as a competing endogenous RNA in PCa by adsorbing miR-628-5p and thereby increasing the expression of MTDH, resulting in enhanced PCa progression. The identification of a novel DARS-AS1/miR-628-5p/MTDH regulatory network in PCa cells may offer a new theoretical basis for the development of promising therapeutic targets.

Keywords: DARS antisense RNA 1; ceRNA theory; non-coding RNA; target therapy.

OBJECTIVE

MTDH/AEG-1 could act as an oncogene by regulating cellular transformation, proliferation, invasion, metastasis, and angiogenesis. This study aims to explore the mechanism by which MTDH/AEG-1 inhibits cancer growth and metastasis and enhances chemosensitivity.

METHODS

Mouse model was established using orally immunized mice exposed to attenuated Salmonella containing vectors carrying full length MTDH/AEG-1 gene, and we were able to enhance the immune response and inhibit the growth and metastasis of prostate cancer through activation of cellular and humoral immunities and induction of CD8+ T cells. Immunohistochemistry and TUNEL assay, CD4+ and CD8+ T cell analysis by flow cytometry, HE staining, RT-PCR analysis, Western-blot analysis and quantitative polymerase chain reaction were performed.

RESULTS

The MTDH/AEG-1 gene vaccine induced the anti-tumor function of cytotoxic T lymphocytes and CD8+ T cells and inhibited tumor growth and metastasis of prostate cancer. In the therapy model, the MTDH/AEG-1 gene vaccine significantly enhanced chemosensitivity to paclitaxel, inhibited tumor growth, promoted tumor cell apoptosis, and prolonged the survival time of tumor-bearing mice without any apparent side effects.

CONCLUSIONS

Our results demonstrated that MTDH/AEG-1-based DNA vaccines could used for the treatment of prostate cancer in terms of the inhibition of tumor growth, the lifespan of tumor-bearing animals. Combined with chemotherapy, MTDH/AEG-1-based DNA vaccines may produce highly favorable outcomes in the prevention and treatment of prostate cancer, suggesting the immune efficacy of MTDH/AEG-1-based DNA should be further analyzed in other cancers.

Metadherin (MTDH) is widely recognized as a promising molecular marker for tumor recurrence and poor survival in many cancers. By multiple pathways, MTDH promotes oncogenesis, metastasis, and chemoresistance. This study investigated the role of MTDH in papillary thyroid carcinoma (PTC) to determine its potential association with aggressive clinical and pathologic features, including its relation in tumors harboring a BRAF (V600E) mutation.

Expression of MTDH was assessed by immunohistochemistry in 96 cases of PTC, including primary thyroid malignancies and lymph node metastases. The status of BRAF (V600E) mutation was determined by real-time polymerase chain reaction.

Overexpression of MTDH was observed in 26 % (23/88) of primary PTC cases. High-intensity staining was observed in 75 % (6/8) of lymph nodes with metastatic PTC and moderate staining in 25 % (2/8) of cases. Normal adjacent thyroid tissue and benign thyroid controls were found to have significantly lower MTDH expression than cancer tissue (p < 0.05). Apical staining of MTDH was observed in 19 % of thyroid tumors and not observed in normal thyroid tissue. Interestingly, MTDH expression was associated with extrathyroidal extension (p < 0.05) and not associated with age, gender, overall tumor stage, or BRAF (V600E) mutation status.

In a subset of PTC patients, MTDH was overexpressed and associated with extrathyroidal extension. Further studies are warranted to explore the utility of MTDH to improve risk stratification of current molecular panels for PTC.

Triple negative breast cancer (TNBC) is aggressive in nature, resistant to conventional therapy and often ends in organ specific metastasis. In this study, publicly available datasets were used to identify miRNA, mRNA and lncRNA hubs. Using validated mRNA-miRNA, mRNA-mRNA and lncRNA-miRNA interaction information obtained from various databases, RNA interaction networks for TNBC and its subtype specific as well as organ tropism regulated metastasis were generated. Further, miRNA-mRNA-lncRNA triad classification was performed using social network analysis from subnetworks and visualized using Cytoscape. Survival analysis of the RNA hubs, oncoprint analysis for mRNAs and pathway analysis of the lncRNAs were also performed. Results indicated that two lncRNAs (NEAT1 and CASC7) and four miRNAs (hsa-miR-106b-5p, hsa-miR-148a-3p, hsa-miR-25-3p and hsa-let-7i-5p) were common between hubs identified in TNBC and TNBC associated metastasis. The exclusive hubs for TNBC associated metastasis were hsa-miR-200b-3p, SP1, HSPA4 and RAB1B. HMGA1 was the top ranked hub in mesenchymal subtype associated lung metastasis, while hsa-miR-27a-3p was identified as the top ranked hub mRNA in luminal androgen receptor subtype associated bone metastasis. When lncRNA associated pathway analysis was performed, Hs Cytoplasmic Ribosomal Protein pathway was found to be the most significant and among the selected hubs, CTNND1, SON and hsa-miR-29c emerged as TNBC survival markers. TP53, FOXA1, MTDH and HDGF were found as the top ranked mRNAs in oncoprint analysis. The pipeline proposed for the first time in this study with validated RNA interaction data integration and graph-based learning for miRNA-mRNA-lncRNA triad classification from RNA hubs may aid experimental cost reduction and its successful execution will allow it to be extended to other diseases too.

Keywords: Lehmann classification; Network analysis; Triad classification; Triple negative breast cancer; lncRNA; mRNA; miRNA.