MicroRNA profiling in human breast cancer cell lines exposed to the anti-neoplastic drug cediranib

EV-miRNAs from breast cancer patients of plasma as potential prognostic biomarkers of disease recurrence

Background

Extracellular vesicles (EVs), ubiquitously released by blood cells, facilitate intercellular communication. In cancer, tumor-derived EVs profoundly affect the microenvironment, promoting tumor progression and raising the risk of recurrence. These EVs contain miRNAs (EV-miRNAs), promising cancer biomarkers. Characterizing plasma EVs and identifying EV-miRNAs associated with breast cancer recurrence are crucial aspects of cancer research since they allow us to discover new biomarkers that are effective for understanding tumor biology and for being used for early detection, disease monitoring, or approaches to personalized medicine. This study aimed to characterize plasma EVs in breast cancer (BC) patients and identify EV-miRNAs associated with BC recurrence.

Methods

This retrospective observational study included 24 BC patients divided into recurrence (n= 11) and non-recurrence (n= 13) groups. Plasma EVs were isolated and characterized. Total RNA from EVs was analyzed for miRNA expression using NanoString's nCounter® miRNA Expression Assays panel. MicroRNA target prediction used mirDIP, and pathway interactions were assessed via Reactome.

Results

A stronger presence of circulating EVs was found to be linked with a less favorable prognosis (p = 0.0062). We discovered a distinct signature of EV-miRNAs, notably including miR-19a-3p and miR-130b-3p, which are significantly associated with breast cancer recurrence. Furthermore, miR-19a-3p and miR-130b-3p were implicated in the regulation of PTEN and MDM4, potentially contributing to breast cancer progression.A notable association emerged, indicating a high concentration of circulating EVs predicts poor prognosis (p = 0.0062). Our study found a distinct EV-miRNA signature involving miR-19a-3p and miR-130b-3p, strongly associated with disease recurrence. We also presented compelling evidence for their regulatory roles in PTEN and MDM4 genes, contributing to BC development.

Conclusion

This study revealed that increased plasma EV concentration is associated with BC recurrence. The prognostic significance of EVs is closely tied to the unique expression profiles of miR-19a-3p and miR-130b-3p. These findings underscore the potential of EV-associated miRNAs as valuable indicators for BC recurrence, opening new avenues for diagnosis and treatment exploration.

Preclinical Evaluation of Ixabepilone in Combination with VEGF Receptor and PARP Inhibitors in Taxane-Sensitive and Taxane-Resistant MDA-MB-231 Breast Cancer Cells

Long-term use of cytotoxic agents promotes drug-resistance in triple-negative breast cancer (TNBC). The identification of new drug combinations with efficacy against drug-resistant TNBC cells in vitro is valuable in developing new clinical strategies to produce further cancer remissions. We undertook combination analysis of the cytotoxic agent ixabepilone with small molecule inhibitors of vascular endothelial growth factor receptor (VEGFR) and poly (ADP-ribose) polymerase (PARP) in taxane-sensitive (231C) and taxane-resistant (TXT) MDA-MB-231-derived cells. As single agents, the VEGFR inhibitors cediranib and bosutinib decreased both 231C and TXT cell viability, but four other VEGFR inhibitors and two PARP inhibitors were less effective. Combinations of ixabepilone with either cediranib or bosutinib synergistically decreased 231C cell viability. However, only the ixabepilone/cediranib combination was synergistic in TXT cells, with predicted 15.3-fold and 1.65-fold clinical dose reductions for ixabepilone and cediranib, respectively. Flow cytometry and immunoblotting were used to further evaluate the loss of cell viability. Thus, TXT cell killing by ixabepilone/cediranib was enhanced over ixabepilone alone, and expression of proapoptotic cleaved caspase-3 and the Bak/Bcl-2 protein ratio were increased. These findings suggest that the synergistic activity of the ixabepilone/cediranib combination in taxane-sensitive and taxane-resistant cells may warrant clinical evaluation in TNBC patients.

Integrated analysis of mRNA and miRNA profiles revealed the role of miR-193 and miR-210 as potential regulatory biomarkers in different molecular subtypes of breast cancer

BACKGROUND

Breast cancer is the most frequently diagnosed malignancy among women. However, the role of microRNA (miRNA) expression in breast cancer progression is not fully understood. In this study we examined predictive interactions between differentially expressed miRNAs and mRNAs in breast cancer cell lines representative of the common molecular subtypes. Integrative bioinformatics analysis identified miR-193 and miR-210 as potential regulatory biomarkers of mRNA in breast cancer. Several recent studies have investigated these miRNAs in a broad range of tumors, but the mechanism of their involvement in cancer progression has not previously been investigated.

METHODS

The miRNA-mRNA interactions in breast cancer cell lines were identified by parallel expression analysis and miRNA target prediction programs. The expression profiles of mRNA and miRNAs from luminal (MCF-7, MCF-7/AZ and T47D), HER2 (BT20 and SK-BR3) and triple negative subtypes (Hs578T e MDA-MB-231) could be clearly separated by unsupervised analysis using HB4A cell line as a control. Breast cancer miRNA data from TCGA patients were grouped according to molecular subtypes and then used to validate these findings. Expression of miR-193 and miR-210 was investigated by miRNA transient silencing assays using the MCF7, BT20 and MDA-MB-231 cell lines. Functional studies included, xCELLigence system, ApoTox-Glo triplex assay, flow cytometry and transwell inserts were performed to determine cell proliferation, cytotoxicity, apoptosis, migration and invasion, respectively.

RESULTS

The most evident effects were associated with cell proliferation after miR-210 silencing in triple negative subtype cell line MDA-MB-231. Using in silico prediction algorithms, TNFRSF10 was identified as one of the potential regulated downstream targets for both miRNAs. The TNFRSF10C and TNFRSF10D mRNA expression inversely correlated with the expression levels of miR-193 and miR210 in breast cell lines and breast cancer patients, respectively. Other potential regulated genes whose expression also inversely correlated with both miRNAs were CCND1, a known mediator on invasion and metastasis, and the tumor suppressor gene RUNX3.

CONCLUSIONS

In summary, our findings identify miR-193 and miR-210 as potential regulatory miRNA in different molecular subtypes of breast cancer and suggest that miR-210 may have a specific role in MDA-MB-231 proliferation. Our results highlight important new downstream regulated targets that may serve as promising therapeutic pathways for aggressive breast cancers.

New emerging roles of microRNAs in breast cancer

BACKGROUND

MicroRNAs constitute a large family of non-coding RNAs, which actively participate in tumorigenesis by regulating a set of mRNAs of distinct signaling pathways. An altered expression of these molecules has been found in different tumorigenic processes of breast cancer, the most common type of cancer in the female population worldwide.

PURPOSE

The objective of this review is to discuss how miRNAs become master regulators in breast tumorigenesis.

METHODS

An integrative review of miRNAs and breast cancer literature from the last 5 years was done on PubMed. We summarize recent works showing that the defects on the biogenesis of miRNAs are associated with different breast cancer characteristics. Then, we show several examples that demonstrate the link between cellular processes regulated by miRNAs and the hallmarks of breast cancer. Finally, we examine the complexity in the regulation of these molecules as they are modulated by other non-coding RNAs and the clinical applications of miRNAs as they could serve as good diagnostic and classification tools.

CONCLUSION

The information presented in this review is important to encourage new directed studies that consider microRNAs as a good tool to improve the diagnostic and treatment alternatives in breast cancer.

MiR-449a suppresses cell migration and invasion by targeting PLAGL2 in breast cancer

BACKGROUND

Breast cancer is one of the most common malignancies worldwide. However, the detailed molecular mechanisms underlying breast cancer metastasis are still incompletely clear. MicroRNAs (miRNAs) play a crucial role in cancer metastasis. In this study, we aimed to analyze the expression and function of miR-449a in breast cancer.

MATERIAL AND METHODS

A total of 15 human primary breast cancer tissues and adjacent non-cancerous tissues (10 pairs) were obtained. MiR-449a was examined in tumor tissues and adjacent nontumorous tissues of breast cancer patients and cell lines by real-time PCR. The protein expression levels were analyzed by western blot and immunohistochemistry staining. Luciferase reporter assays was used to validate the target of miR-449a. The effect of miR-449a on breast cancer cell migration and invasion were studied in vitro and in vivo.

RESULTS

The expression levels of miR-449a were significantly decreased in breast cancer tissues and cell lines. Overexpression of miR-449a suppressed breast cancer cell proliferation, clone formation, migration, invasion and metastasis in vitro and in vivo. Pleomorphic adenoma gene like-2 (PLAGL2) was identified as a major target of miR-449a. Both overexpression of miR-449a inhibited the expression of PLAGL2 significantly and the knockdown of PLAGL2 expression inhibited the breast cancer cell proliferation and metastasis.

CONCLUSION

We demonstrate the miR-449a tumor suppressor role in breast cancer cell migration and invasion via targeting PLAGL2. These findings suggesting that miR-449a/PLAGL2 could serve as a therapeutic strategy for targeting breast cancer.

MicroRNA expression profiles in benign prostatic hyperplasia

Although alterations in microRNA (miRNA) expression have been previously investigated prostate cancer, the expression of miRNAs specifically in benign prostate hyperplasia (BPH) of the prostatic stroma remains to be fully elucidated. In the present study, miRNAs and gene expression profiles were investigated using microarray analysis and reverse transcription quantitative‑polymerase chain reaction (RT‑qPCR) in BPH tissue to clarify the associations between miRNA expression and target genes. Prostate tissue samples from five patients with BPH and five healthy men were analyzed using human Affymetrix miRNA and mRNA microarrays and differentially expressed miRNAs were validated using RT‑qPCR with 30 BPH and 5 healthy control samples. A total of 8 miRNAs, including miRNA (miR)‑96‑5p, miR‑1271‑5p, miR‑21‑3p, miR‑96‑5p, miR‑181a‑5p, miR‑143‑3p, miR‑4428 and miR‑106a‑5p were upregulated and 8 miRNAs (miR‑16‑5p, miR‑19b‑5p, miR‑940, miR‑25, miR‑486‑3p, miR‑30a‑3p, let‑7c and miR‑191) were downregulated. Additionally, miR‑96‑5p was demonstrated to have an inhibitory effect on the mRNA expression levels of the following genes: Mechanistic target of rapamycin (MTOR), RPTOR independent companion of MTOR complex 2, syntaxin 10, autophagy‑related protein 9A, zinc finger E‑box binding homeobox 1, caspase 2 and protein kinase c ε. Additionally, 16 differentially expressed miRNAs were identified using RT‑qPCR analysis. This preliminary study provides a solid basis for a further functional study to investigate the underlying regulatory mechanisms of BPH.

Up-regulation of microRNA-202-3p in first trimester placenta of pregnancies destined to develop severe preeclampsia, a pilot study

MicroRNA (miRNA) expression has not been studied during placentation in pregnancies that develop preeclampsia, when it likely manifests. In this pilot study, miRNA expression in late first trimester placenta from four pregnancies that developed severe preeclampsia matched to controls using the Affymetrix GeneChip® miRNA 3.0 Array identified 9 miRNAs differentially expressed, with miR-202-3p the most significantly overexpressed in severe preeclampsia. Real-time reverse transcription polymerase chain reaction (qRT-PCR) confirmed overexpression of miR-202-3p in a validation cohort, with a 7-fold increase in pregnancies that developed severe preeclampsia (p≤0.05). Differential miRNA expression, specifically miR-202-3p, is seen in first trimester placenta in severe preeclampsia.