Alberto Villanueva

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MicroRNAs (miRNAs) are small, noncoding RNAs that can contribute to cancer development and progression by acting as oncogenes or tumor suppressor genes. Recent studies have also linked different sets of miRNAs to metastasis through either the promotion or suppression of this malignant process. Interestingly, epigenetic silencing of miRNAs with tumor(More)
microRNAs (miRNAs) are small noncoding RNAs that regulate gene expression by targeting messenger RNA (mRNA) transcripts. Recently, a miRNA expression profile of human tumors has been characterized by an overall miRNA downregulation. Explanations for this observation include a failure of miRNA post-transcriptional regulation, transcriptional silencing(More)
Exosomes are secreted by all cell types and contain proteins and nucleic acids. Here, we report that breast cancer associated exosomes contain microRNAs (miRNAs) associated with the RISC-Loading Complex (RLC) and display cell-independent capacity to process precursor microRNAs (pre-miRNAs) into mature miRNAs. Pre-miRNAs, along with Dicer, AGO2, and TRBP,(More)
Notch has been linked to beta-catenin-dependent tumorigenesis; however, the mechanisms leading to Notch activation and the contribution of the Notch pathway to colorectal cancer is not yet understood. By microarray analysis, we have identified a group of genes downstream of Wnt/beta-catenin (down-regulated when blocking Wnt/beta-catenin) that are directly(More)
Epithelial-mesenchymal (EMT) and mesenchymal-epithelial (MET) transitions occur in the development of human tumorigenesis and are part of the natural history of the process to adapt to the changing microenvironment. In this setting, the miR-200 family is recognized as a master regulator of the epithelial phenotype by targeting ZEB1 and ZEB2, two important(More)
UNLABELLED Recently, there has been an increasing interest in the development and characterization of patient-derived tumor xenograft (PDX) models for cancer research. PDX models mostly retain the principal histologic and genetic characteristics of their donor tumor and remain stable across passages. These models have been shown to be predictive of clinical(More)
The global impairment of mature microRNAs (miRNAs) is emerging as a common feature of human tumors. One interesting scenario is that defects in the nuclear export of precursor miRNAs (pre-miRNAs) might occur in transformed cells. Exportin 5 (XPO5) mediates pre-miRNA nuclear export and herein we demonstrate the presence of XPO5-inactivating mutations in a(More)
Disruption of the histone modification patterns is one of the most common features of human tumors. However, few genetic alterations in the histone modifier genes have been described in tumorigenesis. Herein we show that the histone methyltransferase SETDB1 undergoes gene amplification in non-small and small lung cancer cell lines and primary tumors. The(More)
RATIONALE Identification of risk factors for lung cancer can help in selecting patients who may benefit the most from smoking cessation interventions, early detection, or chemoprevention. OBJECTIVE To evaluate whether the presence of emphysema on low-radiation-dose CT (LDCT) of the chest is an independent risk factor for lung cancer. METHODS The study(More)
Nuclear functions for IkappaB kinase (IKK), including phosphorylation of histone H3 and nuclear corepressors, have been recently described. Here, we show that IKK is activated in colorectal tumors concomitant with the presence of phosphorylated SMRT (silencing mediator of retinoic acid and thyroid hormone receptor) corepressor that is aberrantly localized(More)