Steroidogenic factor-1 (SF-1/Ad4BP; NR5A1), a nuclear receptor transcription factor, has a pivotal role in adrenal and gonadal development in humans and mice. A frequent feature of childhood adrenocortical tumors is SF-1 amplification and overexpression. Here we show that an increased SF-1 dosage can by itself augment human adrenocortical cell proliferation through concerted actions on the cell cycle and apoptosis. This effect is dependent on an intact SF-1 transcriptional activity. Gene expression profiling showed that an increased SF-1 dosage regulates transcripts involved in steroid metabolism, the cell cycle, apoptosis, and cell adhesion to the extracellular matrix. Consistent with these results, increased SF-1 levels selectively modulate the steroid secretion profile of adrenocortical cells, reducing cortisol and aldosterone production and maintaining dehydroepiandrosterone sulfate secretion. As a model to understand the mechanisms of transcriptional regulation by increased SF-1 dosage, we studied FATE1, coding for a cancer-testis antigen implicated in the control of cell proliferation. Increased SF-1 levels increase its binding to a consensus site in FATE1 promoter and stimulate its activity through modulation of the recruitment of specific cofactors. On the other hand, sphingosine, which can compete with phospholipids for binding to SF-1, had no effect on the SF-1 dosage-dependent increase of adrenocortical cell proliferation and expression of the FATE1 promoter. In mice, increased Sf-1 dosage produces adrenocortical hyperplasia and formation of tumors expressing gonadal markers (Amh, Gata-4), which originate from the subcapsular region of the adrenal cortex. Gene expression profiling revealed that genes involved in cell adhesion and the immune response and transcription factor signal transducer and activator of transcription-3 (Stat3) are differentially expressed in Sf-1 transgenic mouse adrenals compared with wild-type adrenals. Our studies reveal a critical role for SF-1 dosage in adrenocortical tumorigenesis and constitute a rationale for the development of drugs targeting SF-1 transcriptional activity for adrenocortical tumor therapy.

NKX3.1 is a prostate-specific homeoprotein and tumor suppressor that is affected by the loss of 8p21 in prostate cancer. In mice, Nkx3.1 haploinsufficiency results in prostatic dysplasia and complements cancer formation induced by loss of other suppressor genes. However, NKX3.1 expression can be immunohistochemically detected in most primary prostate cancers. We examined the relationship between suppressor gene haploinsufficiency, methylation, and quantitative NKX3

One-third of all estrogen receptor (ER)-positive breast tumors treated with endocrine therapy fail to respond, and the remainder is likely to relapse in the future. Almost all data on endocrine resistance has been obtained in models of invasive ductal carcinoma (IDC). However, invasive lobular carcinomas (ILC) comprise up to 15% of newly diagnosed invasive breast cancers each year and, whereas the incidence of IDC has remained relatively constant during the last 20 years, the prevalence of ILC continues to increase among postmenopausal women. We report a new model of Tamoxifen (TAM)-resistant invasive lobular breast carcinoma cells that provides novel insights into the molecular mechanisms of endocrine resistance. SUM44 cells express ER and are sensitive to the growth inhibitory effects of antiestrogens. Selection for resistance to 4-hydroxytamoxifen led to the development of the SUM44/LCCTam cell line, which exhibits decreased expression of ERA and increased expression of the estrogenrelated receptor ; (ERR;). Knockdown of ERR; in SUM44/ LCCTam cells by siRNA restores TAM sensitivity, and overexpression of ERR; blocks the growth-inhibitory effects of TAM in SUM44 and MDA-MB-134 VI lobular breast cancer cells. ERR;-driven transcription is also increased in SUM44/ LCCTam, and inhibition of activator protein 1 (AP1) can restore or enhance TAM sensitivity. These data support a role for ERR;/AP1 signaling in the development of TAM resistance and suggest that expression of ERR; may be a marker of poor TAM response. [Cancer Res 2008;68(21):8908-17]

Southern Brazil has one of the highest incidences of childhood adrenocortical tumors (ACTs), occurring 10-15 times more frequently than worldwide estimates. The reasons for this increase remain elusive. In an attempt to further characterize the genetic changes in childhood ACTs, we recently detected a consistent gain of 9q (or a portion of it) in eight of nine cases of pediatric ACTs and amplification of 9q34 in the majority of these cases using comparative genomic hybridization. Other studies involving both childhood and adult ACTs have corroborated these findings. To follow up on these results, we examined whether the steroidogenic factor 1 (SF-1) gene, which is located in this chromosomal region and plays an important role in the development and function of the adrenal cortex is amplified in these ACT cases. We detected increased copy number of the SF-1 gene in all eight cases with 9q gain, suggesting an association between an increased copy number of the SF-1 gene and adrenocortical tumorigenesis.

No abstract

Triple Negative Breast Cancer (TNBC), a clinically aggressive subtype of breast cancer, disproportionately affects African American (AA) women when compared to non-Hispanic Whites (NHW). MiRNAs(miRNAs) play a critical role in these tumors, through the regulation of cancer driver genes. In this study, our goal was to characterize and compare the patterns of miRNA expression in TNBC of AA (n = 27) and NHW women (n = 30). A total of 256 miRNAs were differentially expressed between these groups, and distinct from the ones observed in their respective non-TNBC subtypes. Fifty-five of these miRNAs were mapped in cytobands carrying copy number alterations (CNAs); 26 of them presented expression levels concordant with the observed CNAs. Receiving operating characteristic (ROC) analysis showed a good power (AUC ≥ 0.80; 95% CI) for over 65% of the individual miRNAs and a high combined power with superior sensitivity and specificity (AUC = 0.88 (0.78−0.99); 95% CI) of the 26 miRNA panel in discriminating TNBC between these populations. Subsequent miRNA target analysis revealed their involvement in the interconnected PI3K/AKT, MAPK and insulin signaling pathways. Additionally, three miRNAs of this panel were associated with early age at diagnosis. Altogether, these findings indicated that there are different patterns of miRNA expression between TNBC of AA and NHW women and that their mapping in genomic regions with high levels of CNAs is not merely physical, but biologically relevant to the TNBC phenotype. Once validated in distinct cohorts of AA women, this panel can potentially represent their intrinsic TNBC genome signature.

No abstract

MicroRNAs (miRNAs) are critical modulators of endothelial homeostasis, which highlights their involvement in vascular diseases, including the ones caused by virus infections. Our main objective was to identify miRNAs involved in the endothelial function and determine their expression in post-mortem lung biopsies of COVID-19 patients with severe respiratory injuries and thrombotic events. Based on functional enrichment analysis, miR-26a-5p, miR-29b-3p, and miR-34a-5p were identified as regulators of mRNA targets involved in endothelial, and inflammatory signaling pathways as well as in viral diseases. A miRNA/mRNA network, constructed based on protein-protein interactions of the miRNA targets and the inflammatory biomarkers characterized in the patients, revealed a close interconnection of these miRNAs with relevance to the endothelial activation/dysfunction. Reduced expression levels of selected miRNAs were observed in the lung biopsies of COVID-19 patients (n=9) compared to the Controls (n=10)(P<0.01-0.0001). MiR-26a-5p and miR-29b-3p presented the best power to discriminate these groups (AUC=0.8286, and AUC=0.8125, respectively). The correlation analysis of the miRNAs with inflammatory biomarkers in the COVID-19 patients was significant for miR-26a-5p [IL-6 (r2=0.5414), and ICAM-1(r2=0.5624)], and miR-29b-3p [IL-4 (r2=0.8332), and IL-8 (r2=0.2654)]. Altogether, these findings demonstrate the relevance and the non-random involvement of miR-26a-5p, miR-29b-3p, and miR-34a-5p in endothelial dysfunction and inflammatory response in patients with SARS-CoV-2 infection and the occurrence of severe lung injury and immunothrombosis.