Profiling differential microRNA expression between in situ, infiltrative and lympho-vascular space invasive breast cancer: a pilot study

Should low-risk DCIS lose the cancer label? An evidence review

BACKGROUND

Population mammographic screening for breast cancer has led to large increases in the diagnosis and treatment of ductal carcinoma in situ (DCIS). Active surveillance has been proposed as a management strategy for low-risk DCIS to mitigate against potential overdiagnosis and overtreatment. However, clinicians and patients remain reluctant to choose active surveillance, even within a trial setting. Re-calibration of the diagnostic threshold for low-risk DCIS and/or use of a label that does not include the word 'cancer' might encourage the uptake of active surveillance and other conservative treatment options. We aimed to identify and collate relevant epidemiological evidence to inform further discussion on these ideas.

METHODS

We searched PubMed and EMBASE databases for low-risk DCIS studies in four categories: (1) natural history; (2) subclinical cancer found at autopsy; (3) diagnostic reproducibility (two or more pathologist interpretations at a single time point); and (4) diagnostic drift (two or more pathologist interpretations at different time points). Where we identified a pre-existing systematic review, the search was restricted to studies published after the inclusion period of the review. Two authors screened records, extracted data, and performed risk of bias assessment. We undertook a narrative synthesis of the included evidence within each category.

RESULTS

Natural History (n = 11): one systematic review and nine primary studies were included, but only five provided evidence on the prognosis of women with low-risk DCIS. These studies reported that women with low-risk DCIS had comparable outcomes whether or not they had surgery. The risk of invasive breast cancer in patients with low-risk DCIS ranged from 6.5% (7.5 years) to 10.8% (10 years). The risk of dying from breast cancer in patients with low-risk DCIS ranged from 1.2 to 2.2% (10 years). Subclinical cancer at autopsy (n = 1): one systematic review of 13 studies estimated the mean prevalence of subclinical in situ breast cancer to be 8.9%. Diagnostic reproducibility (n = 13): two systematic reviews and 11 primary studies found at most moderate agreement in differentiating low-grade DCIS from other diagnoses. Diagnostic drift: no studies found.

CONCLUSION

Epidemiological evidence supports consideration of relabelling and/or recalibrating diagnostic thresholds for low-risk DCIS. Such diagnostic changes would need agreement on the definition of low-risk DCIS and improved diagnostic reproducibility.

Collagen deposition within brain metastases is associated with leptomeningeal failure after cavity-directed radiosurgery

Background

Leptomeningeal failure (LMF) represents a devastating progression of disease following resection of brain metastases (BrM). We sought to identify a biomarker at time of BrM resection that predicts for LMF using mass spectrometry-based proteomic analysis of resected BrM and to translate this finding with histochemical assays.

Methods

We retrospectively reviewed 39 patients with proteomic data available from resected BrM. We performed an unsupervised analysis with false discovery rate adjustment (FDR) to compare proteomic signature of BrM from patients that developed LMF versus those that did not. Based on proteomic analysis, we applied trichrome stain to a total of 55 patients who specifically underwent resection and adjuvant radiosurgery. We used competing risks regression to assess predictors of LMF.

Results

Of 39 patients with proteomic data, FDR revealed type I collagen-alpha-1 (COL1A1, P = .045) was associated with LMF. The degree of trichrome stain in each block correlated with COL1A1 expression (β = 1.849, P = .001). In a cohort of 55 patients, a higher degree of trichrome staining was associated with an increased hazard of LMF in resected BrM (Hazard Ratio 1.58, 95% CI 1.11-2.26, P = .01).

Conclusion

The degree of trichrome staining correlated with COL1A1 and portended a higher risk of LMF in patients with resected brain metastases treated with adjuvant radiosurgery. Collagen deposition and degree of fibrosis may be able to serve as a biomarker for LMF.

miR-145, miR-205 and miR-451: potential tumor suppressors involved in the progression of in situ to invasive carcinoma of the breast

BACKGROUND

MicroRNAs (miRNAs) control diverse biologic processes during tumor progression. This study was conducted to identify miRNAs that are implicated in progression of in situ to invasive breast cancer (IBC) and to evaluate their association with clinicopathological features of ductal carcinoma in situ (DCIS).

METHODS

We performed miRNA microarray analyses to find differentially expressed miRNAs between DCIS and IBC in a test set, and validated expression levels of selected miRNAs using a different set of tumors. Finally, we evaluated the relationship between clinicopathological features and the expression of selected miRNAs in DCIS samples.

RESULTS

We found that miR-145-5p, miR-205-5p and miR-451a are significantly down-regulated in IBC compared to DCIS in the whole group, and in the estrogen receptor (ER)-positive and ER-negative subgroups. In a validation set, miR-145, miR-205, and miR-451 also showed lower expression levels in IBC than in DCIS, irrespective of ER status. Moreover, their expression levels were significantly lower in the invasive component compared to the in situ component within same tumors. MiR-145, miR-205 and miR-451 commonly showed lower expression levels in DCIS with positive HER2 status and high Ki-67 proliferation index. Especially, miR-145 and miR-205 showed lower expression levels in DCIS with microinvasion, compared to pure DCIS. In addition, lower miR-205 expression level was associated with high nuclear grade, comedo type necrosis, and hormone receptor negativity.

CONCLUSIONS

Our study showed that miR-145, miR-205 and miR-451 expression decreased in IBC compared to DCIS, and their expression levels were low in DCIS with high-risk features for progression, implying their contributions in the progression of DCIS to invasive carcinoma as tumor suppressors.

MicroRNAs: The Link between the Metabolic Syndrome and Oncogenesis

Metabolic syndrome (MetS) represents a cluster of disorders that increase the risk of a plethora of conditions, in particular type two diabetes, cardiovascular diseases, and certain types of cancers. MetS is a complex entity characterized by a chronic inflammatory state that implies dysregulations of adipokins and proinflammatory cytokins together with hormonal and growth factors imbalances. Of great interest is the implication of microRNA (miRNA, miR), non-coding RNA, in cancer genesis, progression, and metastasis. The adipose tissue serves as an important source of miRs, which represent a novel class of adipokines, that play a crucial role in carcinogenesis. Altered miRs secretion in the adipose tissue, in the context of MetS, might explain their implication in the oncogenesis. The interplay between miRs expressed in adipose tissue, their dysregulation and cancer pathogenesis are still intriguing, taking into consideration the fact that miRNAs show both carcinogenic and tumor suppressor effects. The aim of our review was to discuss the latest publications concerning the implication of miRs dysregulation in MetS and their significance in tumoral signaling pathways. Furthermore, we emphasized the role of miRNAs as potential target therapies and their implication in cancer progression and metastasis.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

Overexpression of miR-1225 promotes the progression of breast cancer, resulting in poor prognosis

Breast cancer is the most common cancer among women, with metastasis as the principal cause of mortality. MiR-1225 has been reported to play roles in the progression of various cancers, but its role in breast cancer was unclear. The expression of miR-1225 was investigated in breast cancer tissues and cells by quantitative real-time PCR. The role of miR-1225 in the cell process of OS was analyzed by CCK-8 assay and Transwell assay. The prognostic value of miR-1225 was evaluated by Kaplan-Meier survival curves and Cox regression analysis. miR-1225 was significantly upregulated in breast cancer tissues, which was associated with the TNM stage of breast cancer patients. The prognosis of patients with high miR-1225 expression was worse than that of patients with low miR-1225 expression, which indicated that miR-1225 acted as an independent factor for the prognosis of breast cancer. Additionally, the upregulation of miR-1225 promoted cell proliferation, migration, and invasion of breast cancer, which suggested miR-1225 might be involved in the progression of breast cancer. JAK1 was identified as the direct target of miR-1225, which was also involved in cell proliferation, migration, and invasion of breast cancer. The overexpression of miR-1225 in breast cancer indicates a poor prognosis of patients and promotes the progression of breast cancer by targeting JAK1. miR-1225 may be a biomarker and therapeutic target for the treatment of breast cancer.

Overexpression of SOX4 induces up-regulation of miR-126 and miR-195 in LNCaP prostate cancer cell line

The present study aims to investigate the association between SOX4, Wnt signaling, and miRNAs under Wnt3 induction via bioinformatics analysis and functional essays. To briefly explore the expression of SOX4 protein in various types of cancer, we used ONCOMINE, a highly reputable cancer database, for comparison of its expression in prostate carcinoma relative to normal prostate gland. Concomitantly, we used CCLE to plot the copy number of SOX4 against its mRNA expression status in various cancerous cell lines to confirm the carcinogenesis role of SOX4. Afterward, whole profiling expression of microRNA in SOX4-stably expressed LNCaP cell line under the effect of Wnt3A were demonstrated. After identifying microRNA targets, STRING database and MIROB were used to explore the functional connection between proteins and microRNA with proteins. The results from our study shows that over-expressed of SOX4 was confirmed in both carcinogenesis tissue and cancer cell lines in Oncomine and CCLE database. In addition, five miRNAs, miR-16, miR-19a, miR320, miR-195, and miR-126, were differentially expressed in LNCaP cell line induced by Wnt3a. Pathway analysis of these targets proposed interaction networks of SOX4, Wnt3a with miR-126 and miR-195. Altogether, the miRNAs involved in Wnt and SOX4-mediated prostate cancer such as miR-126 and miR-195 could be potential biomarkers in prostate cancer.

MicroRNA-628-5p inhibits invasion and migration of human pancreatic ductal adenocarcinoma via suppression of the AKT/NF-kappa B pathway

The biological function and underlying mechanism of microRNA-628-5p (miR-628-5p) remains to be clarified in the growth and progression of pancreatic ductal adenocarcinoma (PDAC). Here, the expression levels of miR-628-5p in PDAC tissues and cells were detected by quantitative reverse transcriptase polymerase chain reaction and in situ hybridization. The relationship between miR-628-5p expression and clinicopathologic characteristics was examined in human PDAC tissue samples. Gain- and loss-of-function and the putative targets of miR-628-5p were evaluated in PDAC cell lines. The upstream and downstream signals of miR-628-5p in PDAC were also examined. MiR-628-5p was lowly expressed in PDAC tissues and cell lines, and low miR-628-5p expression in PDAC tissues was associated with poor clinicopathological characteristics and shorter overall survival. Functionally, restoration of miR-628-5p expression decreased PDAC cell proliferation, migration, invasion, and promoted cell apoptosis, whereas miR-628-5p silencing abolished these biological behaviors. MiR-628-5p was found to target and negatively regulate phospholipid scramblase 1 and insulin receptor substrate 1 expression, which resulted in the inhibition of the AKT/NF-κB signaling pathway. MYC knockdown led to miR-628-5p upregulation, whereas MYC overexpression repressed miR-628-5p expression. These findings indicate that miR-628-5p functions as a tumor-suppressive microRNA in PDAC and implicate miR-628-5p as a potential therapeutic target for PDAC patients.

Emerging role of microRNA 628-5p as a novel biomarker for cancer and other diseases

MicroRNAs are a family of small, single-stranded RNAs that have key roles in regulating multiple signaling pathways within a cell. Studies have implicated aberrant expression of microRNAs in the development and progression of several pathologies including cancer. MicroRNAs are relatively stable and readily available in body fluids and tissues, making them desirable biomarkers for prognostic and diagnostic purposes in an array of diseases. MicroRNA 628 (5p/3p variants) is located in the 15q21.3 cancer-related region, and evidence suggests its association with various pathologies. The -5p mature variant, microRNA 628-5p, has been reported to be differentially expressed in various cancers, and its expression has been mostly associated with tumor suppression but there are few reports identifying its role in cancer progression. Several studies have also suggested its utility in diagnosis and prognosis of various cancers. Dysregulation of microRNA 628-5p has also been implicated in embryonal implantation defects, autism, immune modulation, myogenesis, cardiovascular disease, viral infection, and skeletal muscle repair. Here, we have provided a comprehensive review on available literature explaining the role of microRNA 628-5p as a potential cancer biomarker as well as briefly describe its function in other diseases and normal physiological conditions.

miR-106b-5p and miR-17-5p could predict recurrence and progression in breast ductal carcinoma in situ based on the transforming growth factor-beta pathway

PURPOSE

Ductal carcinoma in situ (DCIS) is well-known precursor of invasive ductal carcinoma (IDC). Parts of patients show recurrence as DCIS or IDC after local treatment, but there are no established markers predicting relapse. We analyzed changes in miRNA and oncogene expression during DCIS progression/evolution to identify potential markers predicting recurrence.

METHODS

Forty archival tissues diagnosed as primary or recurrent DCIS and DCIS adjacent to IDC were analyzed. MiRNA hierarchical clustering showed up-regulation of miR-17-5p and miR-106b-5p in recurrent DCIS and DCIS adjacent to IDC. Target genes were predicted based on pre-formed miRNA databases and PanCancer Pathway panel. MiRNAs were transfected into MCF-10A and MCF-7 cells; western blot analysis was performed with MCF-7 cell line to evaluate the effects on TGF-β downstream pathway.

RESULTS

miRNA hierarchical clustering showed 17 dysregulated miRNAs, including miR-17-5p and miR-106b-5p. Based on miRNA database and nCounter Pancancer pathway analysis, TGFβRII was selected as target of miR-106b-5p and miR-17-5p. MiR-106b-5p- and miR-17-5p-transfected MCF-7 cells showed decreased expression of TGFβRII, especially in cells transfected with both miRNAs.

CONCLUSION

miR-106b-5p and miR-17-5p might have a role in breast cancer recurrence and progression by suppressing TGF-β activity, leading to early breast cancer carcinogenesis.

Functional Role of miRNAs in the Progression of Breast Ductal Carcinoma in Situ

miRNAs are small RNAs that influence gene expression by targeting mRNAs. Depending on the function of their target genes, miRNAs may regulate the expression of oncogenes and tumor suppressors, thereby contributing to the promotion or inhibition of tumor progression. Ductal carcinoma in situ (DCIS), although often diagnosed as breast cancer, is a potential precursor to invasive ductal carcinoma. Many of the genetic events required for the invasive progression of DCIS occur at the preinvasive stage, and these events include changes in the expression of miRNAs. Aberrant expression of miRNAs can influence specific oncogenic or tumor-suppressive pathways required for breast cancer progression. miRNAs in DCIS have been shown to influence hormone signaling, cell-cell adhesion, epithelial-to-mesenchymal transition, transforming growth factor β signaling, maintenance of cancer stem cells, and modulation of the extracellular matrix. Additionally, extracellular DCIS miRNAs, such as those found in exosomes, may promote invasive progression by modifying the tumor microenvironment. Here, we review the miRNAs that have been identified in DCIS and how they may contribute to the progression to invasive disease. We also touch on the current state of miRNA therapy development, including the current challenges, and discuss the key future perspectives for research into miRNA function for the purpose of miRNA therapy development for DCIS.

Diagnostic and prognostic value of microRNA-628 for cancers

Background: Many studies manifested miRNA-628 (miR-628) was deregulated in various cancers, indicating that miR-628 might serve as a novel biomarker of cancer diagnosis and prognosis, but it's role was still uncertain. This study aimed to evaluate the value of miR-628 in various cancers for diagnosis and prognosis, as well as its predictive power in combination biomarkers.

Materials and Methods: A literature search was performed using Medline (via PubMed), Embase, Web of Science databases, and Ovid platform up to November 2017. Meta-analysis was performed to provide summative outcomes. Quality assessment of each included study was performed.

Results: Twelve articles with 20 studies were included in our meta-analysis, including 8 articles with 15 studies for diagnostic meta-analysis and 4 articles with 5 studies for prognostic meta-analysis. For the diagnostic meta-analysis of miR-628 alone, the overall pooled results for sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under the summary receiver operating characteristic (SROC) curve (AUC) were 0.81 (95% CI: 0.62-0.91), 0.72 (95% CI: 0.48-0.88), 2.90 (95% CI: 1.50-5.40), 0.27 (95% CI: 0.14-0.50), 11.0 (95% CI: 4.00-25.00), and 0.84 (95% CI: 0.80-0.87), respectively. For the diagnostic meta-analysis of miR-628-related combination biomarkers, the above six parameters were 0.89 (95% CI: 0.84-0.92), 0.93 (95% CI: 0.82-0.97), 12.30 (95% CI: 4.70-32.50), 0.12 (95% CI: 0.08-0.19), and 100.00 (95% CI: 28.00-354.00), 0.93 (95% CI: 0.90-0.95), respectively. For the prognostic meta-analysis, patients with lower miR-628 had significant shorter overall survival than high expression of miR-628 (HR = 1.553, 95% CI: 1.041-2.318, z = 2.16, P = 0.031).

Conclusions: This study confirms that miR-628 may be a promising biomarker for cancer diagnosis and prognosis. Expertly, microRNAs combination biomarkers could be a new alternative for clinical application.