Exploration of prognostic factors and the value of adjuvant chemotherapy in T1a,bN0M0 triple-negative breast cancer: a prospective cohort study based on the SEER database.

Background: There are limited published studies on the prognostic predictors and the value of adjuvant chemotherapy (CT) in T1a,bN0M0 triple-negative breast cancer (TNBC) after local therapy. Therefore, the aim of the present study was to explore the prognostic predictors and the value of adjuvant CT in this population. Methods: We identified T1a,bN0M0 TNBC cases registered in the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2015. We analyzed associations between patient characteristics and overall survival (OS) and breast cancer-specific mortality (BCSM), and differences in OS and BCSM in a CT and no chemotherapy (no CT) cohort before and after propensity score matching. Results: Of the 3,065 SEER patients, 1,534 (50.0%) received adjuvant CT. The median follow up was 57 months (interquartile range: 39-75 months). The 5-year OS and cumulative BCSM were 93.6% and 3.3%, respectively. Younger age was not associated with lower OS or higher BCSM in the total and no CT cohorts. Higher histologic grade was associated with lower OS in the no CT cohort, and T1b tumors were associated with higher BCSM in the total cohort. Multivariable analysis showed no association between adjuvant CT and OS or BCSM. Conclusions: Patients with T1a,bN0M0 TNBC had an excellent prognosis with or without adjuvant CT. For this population, higher histologic grade and larger tumor size were predictors of poor prognosis, although the effect of age was complex. Our data did not support using adjuvant CT in patients with T1a,bN0M0 TNBC.

Simultaneous delivery of anti-miRNA and docetaxel with supramolecular self-assembled "chitosome" for improving chemosensitivity of triple negative breast cancer cells.

At present, treating of triple negative breast cancer (TNBC) mainly depends on chemotherapy with more toxic side effects, but the effect is limited and it is highly prone to drug resistance. Gene therapy using anti-microRNAs maybe one of alternative therapeutic strategies. Due to the poor cell permeability and significant in vivo decomposition rate of anti-microRNAs, which limits their clinical application, we developed a core-shell supramolecular nanovector of "chitosome" that were self-assembled from the synthetic amphiphilic chitosan derivatives. The constructed chitosomes could co-load hydrophilic anti-miR-21 and hydrophobic docetaxel (DTX) into one combo nanocarrier with entrapment efficiency of more than 80%, as well as spherical morphology and average particle size of 90 nm. In comparison with the naked ones, anti-miR-21 encapsulated with chitosomes showed significantly increased cellular transfection and stability against degradation by nuclease in serum. Compared with DTX or anti-miR-21 formulations used alone, the co-delivery of the two drugs with the combo chitosome obtained improved chemosensitivity of TNBC cells to DTX treatment through their synergistic mechanisms. Taken together, the developed chitosome could be a promising candidate for simultaneous delivery of insoluble chemotherapeutic drugs and gene agents for TNBC therapy. Graphical abstract.

miR-613 inhibits proliferation and invasion of breast cancer cell via VEGFA.

MicroRNAs (miRNAs) play important roles in the pathogenesis of many types of cancers by negatively regulating gene expression at posttranscriptional level. However, the role of microRNAs in breast cancer, has remained elusive. Here, we identified that miR-613 inhibits breast cancer cell proliferation by negatively regulates its target gene VEGFA. In breast cancer cell lines, CCK-8 proliferation assay indicated that the cell proliferation was inhibited by miR-613, while miR-613 inhibitor significantly promoted the cell proliferation. Transwell assay showed that miR-613 mimics significantly inhibited the migration and invasion of breast cancer cells, whereas miR-613 inhibitors significantly increased cell migration and invasion. Luciferase assays confirmed that miR-613 directly bound to the 3' untranslated region of VEGFA, and western blotting showed that miR-613 suppressed the expression of VEGFA at the protein levels. This study indicated that miR-613 negatively regulates VEGFA and inhibits proliferation and invasion of breast cancer cell lines. Thus, miR-613 may represent a potential therapeutic molecule for breast cancer intervention.

Transcription regulation network analysis of MCF7 breast cancer cells exposed to estradiol.

BACKGROUND: In breast cancer, estrogen receptors have been demonstrated to interact with transcription factors to regulate target gene expression. However, high-throughput identification of the transcription regulation relationship between transcription factors and their target genes in response to estradiol is still in its infancy. PURPOSE: Thus, the objective of our study was to interpret the transcription regulation network of MCF7 breast cancer cells exposed to estradiol. METHODS: In this work, GSE11352 microarray data were used to identify differentially expressed genes (DEGs). RESULTS: Our results showed that the MYB (v-myb myeloblastosis viral oncogene homolog [avian]), PGR (progesterone receptor), and MYC (v-myc myelocytomatosis viral oncogene homolog [avian]) were hub nodes in our transcriptome network, which may interact with ER and, in turn, regulate target gene expression. MYB can up-regulate MCM3 (minichromosome maintenance 3) and MCM7 expression; PGR can suppress BCL2 (B-cell lymphoma 2) expression; MYC can inhibit TGFB2 (transforming growth factor, beta 2) expression. These genes are associated with breast cancer progression via cell cycling and the TGFß signaling pathway. CONCLUSION: Analysis of transcriptional regulation may provide a better understanding of molecular mechanisms and clues to potential therapeutic targets in the treatment of breast cancer.