Prospective validation of a blood-based 9-miRNA profile for early detection of breast cancer in a cohort of women examined by clinical mammography

Plasma microRNA ratios associated with breast cancer detection in a nested case-control study from a mammography screening cohort

Mammographic breast cancer screening is effective in reducing breast cancer mortality. Nevertheless, several limitations are known. Therefore, developing an alternative or complementary non-invasive tool capable of increasing the accuracy of the screening process is highly desirable. The objective of this study was to identify circulating microRNA (miRs) ratios associated with BC in women attending mammography screening. A nested case-control study was conducted within the ANDROMEDA cohort (women of age 46-67 attending BC screening). Pre-diagnostic plasma samples, information on life-styles and common BC risk factors were collected. Small-RNA sequencing was carried out on plasma samples from 65 cases and 66 controls. miR ratios associated with BC were selected by two-sample Wilcoxon test and lasso logistic regression. Subsequent assessment by RT-qPCR of the miRs contained in the selected miR ratios was carried out as a platform validation. To identify the most promising biomarkers, penalised logistic regression was further applied to candidate miR ratios alone, or in combination with non-molecular factors. Small-RNA sequencing yielded 20 candidate miR ratios associated with BC, which were further assessed by RT-qPCR. In the resulting model, penalised logistic regression selected seven miR ratios (miR-199a-3p_let-7a-5p, miR-26b-5p_miR-142-5p, let-7b-5p_miR-19b-3p, miR-101-3p_miR-19b-3p, miR-93-5p_miR-19b-3p, let-7a-5p_miR-22-3p and miR-21-5p_miR-23a-3p), together with body mass index (BMI), menopausal status (MS), the interaction term BMI * MS, life-style score and breast density. The ROC AUC of the model was 0.79 with a sensitivity and specificity of 71.9% and 76.6%, respectively. We identified biomarkers potentially useful for BC screening measured through a widespread and low-cost technique. This is the first study reporting circulating miRs for BC detection in a screening setting. Validation in a wider sample is warranted.Trial registration: The Andromeda prospective cohort study protocol was retrospectively registered on 27-11-2015 (NCT02618538).

Bone Marrow Mesenchymal Cells (BMSCs) on Breast Cancer Cell Proliferation and Metastasis by Regulating Phosphatase and Tensin Homolog 12

Among the newly diagnosed cancers in women, breast cancer metastasis is a key factor contributing to the poor prognosis. BMSCs are critical components for the malignant microenvironment. Studies have shown that the interaction between tumor cells and BMSCs support breast cancer progression. However, BMSCs’ effect on breast cancer cells is not yet clear. BMSCs and breast cancer cell MCF-7 were co-cultured to analyze tumor cell proliferation and apoptosis along with analysis of E-cadherin and Vimentin expression by real-time PCR, interleukin-6 and matrix protease-2 and PTEN12 expression. Co-culture of BMSCs promoted breast cancer cell proliferation, decreased apoptosis-related Caspase 3 activity and downregulated the expression of EMT related factors, upregulated IL-6 secretion and MMP-2, and downregulated PTEN12 expression (P < 0.05). In conclusion, BMSCs can promote breast cancer cell proliferation and survival and affect breast cancer transformation possibly through inhibiting the expression of PTEN12.

Development and validation of a circulating microRNA panel for the early detection of breast cancer

BACKGROUND

Mammography is widely used for breast cancer screening but suffers from a high false-positive rate. Here, we perform the largest comprehensive, multi-center study to date involving diverse ethnic groups, for the identification of circulating miRNAs for breast cancer screening.

METHODS

This study had a discovery phase (n = 289) and two validation phases (n = 374 and n = 379). Quantitative PCR profiling of 324 miRNAs was performed on serum samples from breast cancer (all stages) and healthy subjects to identify miRNA biomarkers. Two-fold cross-validation was used for building and optimising breast cancer-associated miRNA panels. An optimal panel was validated in cohorts with Caucasian and Asian samples. Diagnostic ability was evaluated using area under the curve (AUC) analysis.

RESULTS

The study identified and validated 30 miRNAs dysregulated in breast cancer. An optimised eight-miRNA panel showed consistent performance in all cohorts and was successfully validated with AUC, accuracy, sensitivity, and specificity of 0.915, 82.3%, 72.2% and 91.5%, respectively. The prediction model detected breast cancer in both Caucasian and Asian populations with AUCs ranging from 0.880 to 0.973, including pre-malignant lesions (stage 0; AUC of 0.831) and early-stage (stages I-II) cancers (AUC of 0.916).

CONCLUSIONS

Our panel can potentially be used for breast cancer screening, in conjunction with mammography.

Elevated circRNAs circ_0000745, circ_0001531 and circ_0001640 in human whole blood: Potential novel diagnostic biomarkers for breast cancer

BACKGROUND AND OBJECTIVES

Increasing studies have shown that circular RNAs (circRNAs) have great diagnostic potential in cancer. Here, we examined whether the blood circRNAs could be promising candidates as diagnostic biomarkers in breast cancer.

METHODS

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to detect levels of five circRNAs (circ_0000501, circ_0000745, circ_0001531, circ_0001640 and circ_0001978) in 129 patients with breast cancer, 19 patients with benign breast tumor and 13 healthy controls. The diagnostic accuracy of circRNAs was assessed using the receiver operating characteristic (ROC) curve. A circRNA-miRNA-mRNA network was constructed based on bioinformatic analysis.

RESULTS

QRT-PCR validated that circ_0000745, circ_0001531 and circ_0001640 were upregulated in breast cancer, compared with benign tumor and healthy control. ROC curve analysis revealed that circ_0000745, circ_0001531 and circ_0001640 had good diagnostic potential. Notably, a signature comprising the three circRNAs showed better diagnostic potential, with the area under curve (AUC) of 0.9130 (P < 0.0001). And a circRNA-miRNA-mRNA network revealed that the circRNAs could participate in complex regulated network and thus involve in cancer development and progression.

CONCLUSIONS

Taken together, our findings support the potential of circ_0000745, circ_0001531, circ_0001640 and the three-circRNA signature as biomarkers for breast cancer diagnosis.

miR-934 promotes breast cancer metastasis by regulation of PTEN and epithelial-mesenchymal transition

Breast cancer (BC) is the most commonly diagnosed malignancy and the leading cause of cancer-related mortality among females. Over 90 % of the cases of death in BC patients are attributed to tumor cell metastasis. Therefore, it is urgently needed to investigate the molecular mechanisms of BC metastasis. The expression of miRNA in BC was evaluated by qRT-PCR and bioinformatics analysis. Clone formation, EdU assays, and subcutaneous xenograft model were used to test the growth of BC cells. Wound healing, transwell assays, and lung-metastasis model were used to explore the effect of miR-934 knockdown on cell metastasis. The miR-934 targets in BC were identified through bioinformatics analysis and luciferase reporter assays. The expression of protein was tested by western blot. The binding of mRNA and RNA-binding-protein was verified using RIP assays. miR-934 expression was significantly elevated in BC tissues, especially in those with lymph node metastasis and associated with poor patient prognosis. Experiments in vitro and in vivo showed that that upregulated miR-934 was not necessarily required for the growth of BC cells. However, miR-934 knockdown significantly inhibited the migration and invasion abilities of BC cells. Moreover, PTEN as identified as the direct target of miR-934 in BC, and miR-934 could promote BC cell metastasis by regulation of PTEN and epithelial-mesenchymal transition (EMT). Our results suggested that targeting miR-934 may be a practical treatment for BC cell metastasis.

Significant Changes in Serum MicroRNAs after High Tibial Osteotomy in Medial Compartmental Knee Osteoarthritis: Potential Prognostic Biomarkers

High tibial osteotomy (HTO) is an effective alternative for medial compartmental knee osteoarthritis (OA). Circulating microRNAs (miRNAs) are known to serve as OA-related biomarkers. The present study investigated the differential expression of serum miRNAs before and after HTO to identify potential miRNAs as prognostic biomarkers. miRNA-polymerase chain reaction (PCR) arrays were used to screen for miRNAs in the serum at preoperative and 6-month postoperative time points from six patients, and the differentially expressed miRNAs identified in the profiling stage were validated using real-time PCR at post-operative months 6 and 18 in 27 other HTO-treated patients. Among 84 miRNAs involved in the inflammatory process, three (miR-19b-3p, miR-29c-3p, and miR-424-5p) showed differential expression patterns in the profiling stage (p = 0.011, 0.015, and 0.021, respectively). Levels of these three and four other miRNAs (miR-140-3p, miR-454-3p, miR-let-7e-5p, and miR-885-5p) known to be related to OA progression were evaluated in the serum of 27 patients. Only four miRNAs (miR-19b-3p, miR-140-3p, miR-454-3p, and miR-let-7e-5p) were significantly upregulated at postoperative month 6 (p = 0.003, 0.005, 0.004, and 0.004, respectively), and only miR-140-3p was significantly upregulated up to 18 months after operation (p = 0.003). Together, this study reveals the significantly upregulated serum miRNAs after HTO as potential prognostic biomarkers; however, further studies are warranted to elucidate their clinical implications.

Recent Discoveries of Macromolecule- and Cell-Based Biomarkers and Therapeutic Implications in Breast Cancer

Breast cancer is the most commonly diagnosed cancer type and the leading cause of cancer-related mortality in women worldwide. Breast cancer is fairly heterogeneous and reveals six molecular subtypes: luminal A, luminal B, HER2+, basal-like subtype (ER−, PR−, and HER2−), normal breast-like, and claudin-low. Breast cancer screening and early diagnosis play critical roles in improving therapeutic outcomes and prognosis. Mammography is currently the main commercially available detection method for breast cancer; however, it has numerous limitations. Therefore, reliable noninvasive diagnostic and prognostic biomarkers are required. Biomarkers used in cancer range from macromolecules, such as DNA, RNA, and proteins, to whole cells. Biomarkers for cancer risk, diagnosis, proliferation, metastasis, drug resistance, and prognosis have been identified in breast cancer. In addition, there is currently a greater demand for personalized or precise treatments; moreover, the identification of novel biomarkers to further the development of new drugs is urgently needed. In this review, we summarize and focus on the recent discoveries of promising macromolecules and cell-based biomarkers for the diagnosis and prognosis of breast cancer and provide implications for therapeutic strategies.

miR-365 (microRNA): Potential Biomarker in Oral Squamous Cell Carcinoma Exosomes and Extracellular Vesicles

Introduction: miR-365 is a non-coding microRNA that regulates transcription and has been demonstrated to promote oncogenesis and metastasis in some cancers, while suppressing these effects in others. Many microRNAs are produced and then exported extracellularly in exosomes, which are small extracellular vesicles ranging from 30 to 100 nm that are found in eukaryotic fluids and facilitate many cellular functions. Exosomes and extracellular vesicles are produced by many cell types, including oral cancer cells—although no study to date has evaluated miR-365 and oral cancer exosomes or extracellular vesicles. Based on this information, our research question was to evaluate whether oral cancers produce exosomes or extracellular vesicles containing miR-365. Materials and Methods: Two commercially available oral cancer cell lines (SCC25 and CAL27) and a normal oral keratinocyte (OKF4) were grown in serum-free media, supplemented with exosome-depleted fetal bovine serum. Extracellular vesicles and exosomes were then isolated using the Invitrogen total exosome RNA and protein isolation kit for processing using the hsa-miR-365a-5p microRNA qPCR assay kit. Results: RNA was successfully isolated from the exosome-depleted supernatant from each cell line—SCC9, SCC15, SCC25, and CAL27 (oral squamous cell carcinomas) and OKF4 (oral epithelial cell line). Relative concentrations of RNA were similar among each cell line, which were not significantly different, p = 0.233. RNA quality was established by A260:A280 absorbance using a NanoDrop, revealing purity ranging 1.73–1.86. Expression of miR-16 was used to confirm the presence of microRNA from the extracted exosomes and extracellular vesicles. The presence of miR-365 was then confirmed and normalized to miR-16 expression, which demonstrated an increased level of miR-365 in both CAL27 and SCC25. In addition, the normalized relative quantity (RQ) for miR-365 exhibited greater variation among SCC25 (1.382–4.363) than CAL27 cells (1.248–1.536). Conclusions: These results confirm that miR-365 is not only expressed in oral cancer cell lines, but also is subsequently exported into exosomes and extracellular vesicles derived from these cultures. These data may help to contextualize the potential for this microRNA to contribute to the phenotypes and behaviors of oral cancers that express this microRNA. Future research will begin to investigate these potential mechanisms and pathways and to determine if miR-365 may be useful as an oral cancer biomarker for salivary or liquid biopsies.

Significant changes in synovial fluid microRNAs after high tibial osteotomy in medial compartmental knee osteoarthritis: Identification of potential prognostic biomarkers

High tibial osteotomy (HTO) is a well-established treatment for medial compartmental knee osteoarthritis. Several microRNAs (miRNAs) are involved in osteoarthritis progression and are useful as osteoarthritis-related biomarkers. In this prospective study, we investigated differentially expressed microRNAs in the synovial fluid (SF) before and after HTO in patients with medial compartmental knee osteoarthritis to identify microRNAs that can be used as prognostic biomarkers. We used miRNA-PCR arrays to screen for miRNAs in SF samples obtained preoperatively and 6 months postoperatively from 6 patients with medial compartmental knee osteoarthritis who were treated with medial open wedge HTO. Differentially expressed miRNAs identified in the profiling stage were validated by real-time quantitative PCR in 22 other patients who had also been treated with HTO. All patients radiographically corresponded to Kellgren-Lawrence grade II or III with medial compartmental osteoarthritis. These patients were clinically assessed using a visual analogue scale and Western Ontario McMaster Universities scores. Mechanical axis changes were measured on standing anteroposterior radiographs of the lower limbs assessed preoperatively and at 6 months postoperatively. Among 84 miRNAs known to be involved in the inflammatory process, 14 were expressed in all SF specimens and 3 (miR-30a-5p, miR-29a-3p, and miR-30c-5p) were differentially expressed in the profiling stage. These 3 miRNAs, as well as 4 other miRNAs (miR-378a-5p, miR-140-3p, miR-23a-3p, miR-27b-3p), are related to osteoarthritis progression. These results were validated in the SF from 22 patients. Clinical and radiological outcomes improved after HTO in all patients, and only 2 miRNAs (miR-30c-5p and miR-23a-3p) were significantly differentially expressed between preoperative and postoperative 6-month SF samples (p = 0.006 and 0.007, respectively). Of these two miRNAs, miR-30c-5p correlated with postoperative pain relief. This study provides potential prognostic miRNAs after HTO and further investigations should be considered to determine clinical implications of these miRNAs.

Circulating miRNAs as Diagnostic and Prognostic Biomarkers in Common Solid Tumors: Focus on Lung, Breast, Prostate Cancers, and Osteosarcoma

An early cancer diagnosis is essential to treat and manage patients, but it is difficult to achieve this goal due to the still too low specificity and sensitivity of classical methods (imaging, actual biomarkers), together with the high invasiveness of tissue biopsies. The discovery of novel, reliable, and easily collectable cancer markers is a topic of interest, with human biofluids, especially blood, as important sources of minimal invasive biomarkers such as circulating microRNAs (miRNAs), the most promising. MiRNAs are small non-coding RNAs and known epigenetic modulators of gene expression, with specific roles in cancer development/progression, which are next to be implemented in the clinical routine as biomarkers for early diagnosis and the efficient monitoring of tumor progression and treatment response. Unfortunately, several issues regarding their validation process are still to be resolved. In this review, updated findings specifically focused on the clinical relevance of circulating miRNAs as prognostic and diagnostic biomarkers for the most prevalent cancer types (breast, lung, and prostate cancers in adults, and osteosarcoma in children) are described. In addition, deep analysis of pre-analytical, analytical, and post-analytical issues still affecting the circulation of miRNAs' validation process and routine implementation is included.

Clinical Translatability of "Identified" Circulating miRNAs for Diagnosing Breast Cancer: Overview and Update

The effective management of patients with breast cancer (BC) depends on the early diagnosis of the disease. Currently, BC diagnosis is based on diagnostic imaging and biopsy, while the use of non-invasive circulating biomarkers for diagnosis remains an unmet need. Among the plethora of proposed non-invasive biomarkers, circulating microRNAs (miRNAs) have been considered promising diagnostic molecules because they are very stable in biological fluids and easily detectable. Although the discovery of miRNAs has opened a new avenue for their clinical application, the clinical translatability of these molecules remains unclear. This review analyses the role of circulating miRNAs as BC diagnostic biomarkers and focuses on two essential requirements to evaluate their clinical validity: i) Specificity and ii) consistent expression between the blood and tissue. These two issues were analyzed in depth using the Human miRNA Disease Database (HMDD v3.0) and the free search engine PubMed. One hundred and sixty three BC-associated miRNAs were selected and analyzed for their specificity among all human pathologies that shared deregulation (291) and consistent expression in the bloodstream and the tissue. In addition, we provide an overview of the current clinical trials examining miRNAs in BC. In conclusion, we highlight pitfalls in the translatability of circulating miRNAs into clinical practice due to the lack of specificity and a consistent expression pattern between the tissue and blood.

Evaluation of miRNA-9 and miRNA-34a as potential biomarkers for diagnosis of breast cancer in Iranian women

PURPOSE

MicroRNAs are involved in diverse biological processes and their dysregulation is a common event in various diseases including breast cancer. Breast cancer is a major threat to women's health. This study was designed to examine the expression levels of miR-9 and miR-34a in breast tumor tissue samples and plasma of breast cancer patients, compare their expression pattern between tissue samples and plasma samples of patients and analyze their relationship with tumor clinical features. Also, the potential of these miRNAs as diagnostic biomarkers for breast cancer was investigated.

MATERIALS AND METHODS

The expression levels of miR-9, miR-34a and CDH1 were measured by real-time reverse transcription polymerase chain reaction and ΔΔct method. Data were analyzed using t-test and one-way ANOVA. The sensitivity and specificity of miRNAs were determined by receiver operating characteristic (ROC) curve.

RESULTS AND DISCUSSION

The expression levels of miR-9 and miR-34a were significantly down-regulated in tumor tissues compared to healthy tissues (fold change = 0.26, p = 0.0051 for miR-9 and fold change = 0.55, p = 0.021 for miR-34a). While no significant difference was observed in the expression levels of miR-9 (p = 0.205) and miR-34a (p = 0.132) in plasma samples of patients compared to normal plasma. CDH1 expression in tumor tissue was not significantly different from normal tissue (p = 0.33). We found that expression level of miR-9 in patients with tumor size larger than 5 cm (p = 0.026) and expression level of miR-34a in patients with higher stage (lll & lV, p = 0.03) were significantly down-regulated. Also miR-34a expression level was positively correlated with patient's age (p = 0.03).

CONCLUSION

According to the ROC curves, the area under the curve (AUC) of miR-9 in tissue was 0.71 (p = 0.009) with sensitivity 83.33% and specificity 70.37%. The AUC for miR-34a in tissue was 0.72 (p = 0.007) with sensitivity 72% and specificity 76%. Thus miR-9 and miR-34a have the capability for distinguishing tumor tissues from healthy tissues and the study of their expression levels in tissue may be used as a biomarker for the diagnosis of breast cancer patients from healthy women.

Biomarker significance of plasma and tumor miR-21, miR-221, and miR-106a in osteosarcoma

Osteosarcoma is the most common malignant bone tumor in children and young adults. Despite the use of surgery and multi-agent chemotherapy, osteosarcoma patients who have a poor response to chemotherapy or develop relapses have a dismal outcome. Identification of biomarkers for active disease may help to monitor tumor burden, detect early relapses, and predict prognosis in these patients. In this study, we examined whether circulating miRNAs can be used as biomarkers in osteosarcoma patients. We performed genome-wide miRNA profiling on a discovery cohort of osteosarcoma and control plasma samples. A total of 56 miRNAs were upregulated and 164 miRNAs were downregulated in osteosarcoma samples when compared to control plasma samples. miR-21, miR-221 and miR-106a were selected for further validation based on their known biological importance. We showed that all three circulating miRNAs were expressed significantly higher in osteosarcoma samples than normal samples in an independent cohort obtained from the Children’s Oncology Group. Furthermore, we demonstrated that miR-21 was expressed significantly higher in osteosarcoma tumors compared with normal bone controls. More importantly, lower expressions of miR-21 and miR-221, but not miR-106a, significantly correlated with a poor outcome. In conclusion, our results indicate that miR-21, miR-221 and miR-106a were elevated in the circulation of osteosarcoma patients, whereas tumor expressions of miR-21 and miR-221 are prognostically significant. Further investigation of these miRNAs may lead to a better prognostic method and potential miRNA therapeutics for osteosarcoma.

Circulating cell-free microRNAs as clinical cancer biomarkers

MicroRNAs (miRNAs) are non-coding small RNAs that are master regulators of genic expression and consequently of many cellular processes. But their expression is often deregulated in human tumors leading to cancer development. Recently miRNAs were discovered in body fluids (serum, plasma and others) and their levels have often been reported to be altered in patients. Circulating miRNAs became one of the most promising biomarkers in oncology for early diagnosis, prognosis and therapeutic response prediction. Here we describe the origins and roles of miRNAs, and summarize the most recent studies focusing on their usefulness as cancer biomarkers in lung, breast, colon, prostate, ovary cancers and melanoma. Lastly, we describe the main methodologies related to miRNA detection, which should be standardized for their use in clinical practice.

Prospective validation of a blood-based 9-miRNA profile for early detection of breast cancer in a cohort of women examined by clinical mammography

Mammography is the predominant screening method for early detection of breast cancer, but has limitations and could be rendered more accurate by combination with a blood-based biomarker profile. Circulating microRNAs (miRNAs) are increasingly recognized as strong biomarkers, and we previously developed a 9-miRNA profile using serum and LNA-based qPCR that effectively stratified patients with early stage breast cancer vs. healthy women. To further develop the test into routine clinical practice, we collected serum of women examined by clinical mammography (N = 197) according to standard operational procedures (SOPs) of the Danish Cancer Biobank. The performance of the circulating 9-miRNA profile was analyzed in 116 of these women, including 36 with breast cancer (aged 50-74), following a standardized protocol that mimicked a routine clinical set-up. We confirmed that the profile is significantly different between women with breast cancer and controls (p-value <0.0001), with an AUC of 0.61. Significantly, one woman whose 9-miRNA profile predicted a 73% probability of having breast cancer indeed developed the disease within one year despite being categorized as clinically healthy at the time of blood sample collection and mammography. We propose that this miRNA profile combined with mammography will increase the overall accuracy of early detection of breast cancer.