ANXA2 expression in African American triple-negative breast cancer patients.

PURPOSE: Our aim was to determine the role of Annexin A2 (AnxA2), which we have previously found to contribute to the aggressiveness of TNBC, with AA TNBC patients and clinical outcome. METHODS: We analyzed TCGA breast cancer database (n = 1098) to observe AnxA2 expression within breast cancer subtypes and is correlation with overall survival. Further, we examined breast tissue specimens (n = 119) through chromogenic in situ hybridization (CISH) and specimen were scored independently by two pathologists in a blinded study. RESULTS: In our TCGA analysis, high expression of AnxA2 was correlated with poor survival in patients with TNBC. AnxA2 gene expression was not correlated with poor survival in other breast cancer subtypes. AnxA2 average CISH intensity score (CISH score = 0, null expression to 3, high expression) for TNBC was significantly higher in comparison to estrogen receptor and/or progesterone receptor positive, human epidermal growth factor positive, and non-malignant tissues. Furthermore, AnxA2 average score was significantly higher in AA TNBC patients (CISH average score = 2.45 ± 0.3266) in comparison to Caucasian TNBC patients (CISH average score = 1.1 ± 0.4069). CONCLUSION: AnxA2 is overexpressed in TNBC, implicating AnxA2 as a contributor to the aggressive biology of TNBC in AA women.

MicroRNA-940 suppresses prostate cancer migration and invasion by regulating MIEN1.

BACKGROUND: MicroRNAs (miRNAs) are crucial molecules that regulate gene expression and hence pathways that are key to prostate cancer progression. These non-coding RNAs are highly deregulated in prostate cancer thus facilitating progression of the disease. Among the many genes that have gained importance in this disease, Migration and invasion enhancer 1 (MIEN1), a novel gene located next to HER2/neu in the 17q12 amplicon of the human chromosome, has been shown to enhance prostate cancer cell migration and invasion, two key processes in cancer progression. MIEN1 is differentially expressed between normal and cancer cells and tissues. Understanding the regulation of MIEN1 by microRNA may enable development of better targeting strategies. METHODS: The miRNAs that could target MIEN1 were predicted by in silico algorithms and microarray analysis. The validation for miRNA expression was performed by qPCR and northern blotting in cells and by in situ hybridization in tissues. MIEN1 and levels of other molecules upon miRNA regulation was determined by Western blotting, qPCR, and immunofluorescence. The functional effects of miRNA on cells were determined by wound healing cell migration, Boyden chamber cell invasion, clonal and colony formation assays. For knockdown or overexpression of the miRNA or overexpression of MIEN1 3'UTR, cells were transfected with the oligomiRs and plasmids, respectively. RESULTS: A novel miRNA, hsa-miR-940 (miR-940), identified and validated to be highly expressed in immortalized normal cells compared to cancer cells, is a regulator of MIEN1. Analysis of human prostate tumors and their matched normal tissues confirmed that miR-940 is highly expressed in the normal tissues compared to its low to negligible expression in the tumors. While MIEN1 is a direct target of miR-940, miR-940 alters MIEN1 RNA, in a quantity as well as cell dependent context, along with altering its downstream effectors. The miR-940 inhibited migratory and invasive potential of cells, attenuated their anchorage-independent growth ability, and increased E-cadherin expression, implicating its role in mesenchymal-to-epithelial transition (MET). CONCLUSIONS: These results, for the first time, implicate miR-940, a regulator of MIEN1, as a promising novel diagnostic and prognostic tool for prostate cancer.

Exosomal Annexin II Promotes Angiogenesis and Breast Cancer Metastasis.

Tumor-derived exosomes are emerging mediators of tumorigenesis and tissue-specific metastasis. Proteomic profiling has identified Annexin II as one of the most highly expressed proteins in exosomes; however, studies focused on the biological role of exosomal Annexin II (exo-Anx II) are still lacking. In this study, mechanistic insight was sought regarding exo-Anx II and its function in angiogenesis and breast cancer metastasis. Multiple in vitro and in vivo techniques were used to study the role of exo-Anx II in angiogenesis. Using atomic force microscopy and Western blotting, exo-Anx II expression was characterized in normal and breast cancer cells. In addition, organ-specific metastatic breast cancer cells and animal models were used to define the role exo-Anx II in breast cancer metastasis. Results revealed that exo-Anx II expression is significantly higher in malignant cells than normal and premetastatic breast cancer cells. In vitro and in vivo studies demonstrated that exo-Anx II promotes tPA-dependent angiogenesis. Furthermore, in vivo analysis indicated that metastatic exosomes create a favorable microenvironment for metastasis, and exo-Anx II plays an important role in this process, as priming with Anx II-depleted exosomes reduces brain (∼4-fold) and lung (∼2-fold) metastasis. Upon delineating the mechanism, it was discovered that exo-Anx II causes macrophage-mediated activation of the p38MAPK, NF-κB, and STAT3 pathways and increased secretion of IL6 and TNFα. These data demonstrate an important role for exo-Anx II in breast cancer pathogenesis. IMPLICATIONS: Exosome-associated Annexin II plays an important role in angiogenesis and breast cancer metastasis, which can be exploited as a potential biomarker as well as a therapeutic target for diagnosis and treatment of metastatic breast cancer. Mol Cancer Res; 15(1); 93-105. ©2016 AACR.

MIEN1 promotes oral cancer progression and implicates poor overall survival.

Oral squamous cell carcinoma is a highly malignant tumor with the potential to invade local and distant sites and promote lymph node metastasis. Major players underlying the molecular mechanisms behind tumor progression are yet to be fully explored. Migration and invasion enhancer 1 (MIEN1), a novel protein overexpressed in various cancers, facilitates cell migration and invasion. In the present study we investigated the expression and role of MIEN1 in oral cancer progression using an in vitro model, patient derived oral tissues and existing TCGA data. Expression analysis using immortalized normal and cancer cells demonstrated increased expression of MIEN1 in cancer. Assays performed after MIEN1 knockdown in OSC-2 cells showed decreased migration, invasion and filopodia formation; while MIEN1 overexpression in DOK cells increased these characteristics and also up-regulated some Akt/NF-κB effectors, thereby suggesting an important role for MIEN1 in oral cancer progression. Immunohistochemical staining and analyses of oral tissue specimens, collected from patients over multiple visits, revealed significantly more staining in severe dysplasia and squamous cell carcinoma compared to mildly dysplastic or hyperplastic tissues. Finally, this was corroborated with the TCGA dataset, where MIEN1 expression was not only higher in intermediate and high grade cancer with significantly lower survival but also correlated with smoking. In summary, we demonstrate that MIEN1 expression not only positively correlates with oral cancer progression but also seems to be a critical molecular determinant in migration and invasion of oral cancer cells, thereby, playing a possible role in their metastatic dissemination.