PIWI-interacting RNA-YBX1 inhibits proliferation and metastasis by the MAPK signaling pathway via YBX1 in triple-negative breast cancer.

Breast cancer is the second leading cause of death in women worldwide, with triple-negative breast cancer (TNBC) having the worst prognosis. Although there are numerous studies on TNBC, there is no effective treatment for it, and it is still a major problem today. Studies on PIWI-interacting RNAs (piRNAs) are increasing and investigating the mechanism of piRNAs in the proliferation and metastasis of TNBC may lead to new potential treatment targets. Here, we identified a novel piRNA, piR-YBX1, which was downregulated in TNBC compared to matched normal breast tissue. Overexpression of piR-YBX1 significantly inhibited the proliferation, migration, invasion ability of TNBC cells both in vivo and in vitro. Mechanistically, piR-YBX1 could bind directly to mRNA of Y-box binding protein 1 (YBX1) and overexpression of piR-YBX1 downregulated YBX1 in both mRNA and protein levels, while the function of piR-YBX1 could be partly rescued by overexpression of YBX1. In addition, YBX1 could bind to RAF1 which is the key molecule in the MAPK signaling pathway, and overexpression of piR-YBX1 inhibited the p-MEK and p-ERK1/2, which can be reverted by YBX1. In conclusion, our findings discovered that the piR-YBX1/YBX1/MAPK axis suppresses the proliferation and metastasis of TNBC and therefore piR-YBX1 has the potential to be an effective therapeutic agent for breast cancer.

Association of FTH1-Expressing Circulating Tumor Cells With Efficacy of Neoadjuvant Chemotherapy for Patients With Breast Cancer: A Prospective Cohort Study.

BACKGROUND: The association between different phenotypes and genotypes of circulating tumor cells (CTCs) and efficacy of neoadjuvant chemotherapy (NAC) remains uncertain. This study was conducted to evaluate the relationship of FTH1 gene-associated CTCs (F-CTC) with/without epithelial-mesenchymal transition (EMT) markers, or their dynamic changes with the efficacy of NAC in patients with non-metastatic breast cancer. PATIENTS AND METHODS: This study enrolled 120 patients with non-metastatic breast cancer who planned to undergo NAC. The FTH1 gene and EMT markers in CTCs were detected before NAC (T0), after 2 cycles of chemotherapy (T1), and before surgery (T2). The associations of these different types of CTCs with rates of pathological complete response (pCR) and breast-conserving surgery (BCS) were evaluated using the binary logistic regression analysis. RESULTS: F-CTC in peripheral blood ≥1 at T0 was an independent factor for pCR rate in patients with HER2-positive (odds ratio [OR]=0.08, 95% confidence interval [CI], 0.01-0.98, P = .048). The reduction in the number of F-CTC at T2 was an independent factor for BCS rate (OR = 4.54, 95% CI, 1.14-18.08, P = .03). CONCLUSIONS: The number of F-CTC prior to NAC was related to poor response to NAC. Monitoring of F-CTC may help clinicians formulate personalized NAC regimens and implement BCS for patients with non-metastatic breast cancer.

EIF4A3-induced circZFAND6 promotes breast cancer proliferation and metastasis through the miR-647/FASN axis.

AIMS: Circular RNAs (circRNAs) are important regulators in breast cancer progression. However, the underlying mechanism of circRNAs functions in breast cancer remain largely unclear. MAIN METHODS: To investigate the circRNAs expression pattern in breast cancer, high-throughput circRNA microarray assay was used. The top up-regulated circRNA, circZFAND6, was submitted to further experiments, including cell counting kit-8 (CCK-8) assay, colony formation assay, transwell assay and mouse xenograft assay. To investigate the underlying mechanism of circZFAND6 function in breast cancer progression, luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted. KEY FINDINGS: We found a novel circRNA, circZFAND6, was up-regulated in breast cancer tissues and cell lines. Inhibition of circZFAND6 reduced proliferation and metastasis of breast cancer. Mechanically, circZFAND6 acted as a competing endogenous RNA (ceRNA) to sponge miR-647 and increase fatty acid synthase (FASN) expression. And eukaryotic translation initiation factor 4A3 (EIF4A3) was found to bind to circZFAND6 pre-mRNA transcript upstream region, leading to the high expression of circZFAND6 in breast cancer. Inhibition of EIF4A3 also suppressed proliferation and metastasis of breast cancer. SIGNIFICANCE: EIF4A3-induced circZFAND6 up-regulation promoted proliferation and metastasis of breast cancer through the miR-647/FASN axis. Our results uncovered a possible mechanism underlying breast cancer progression and might provide a breast cancer treatment target.

A 10-miRNA risk score-based prediction model for pathological complete response to neoadjuvant chemotherapy in hormone receptor-positive breast cancer.

Patients with hormone receptor (HR)-positive tumors breast cancer usually experience a relatively low pathological complete response (pCR) to neoadjuvant chemotherapy (NAC). Here, we derived a 10-microRNA risk score (10-miRNA RS)-based model with better performance in the prediction of pCR and validated its relation with the disease-free survival (DFS) in 755 HR-positive breast cancer patients (273, 265, and 217 in the training, internal, and external validation sets, respectively). This model, presented as a nomogram, included four parameters: the 10-miRNA RS found in our previous study, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) status, and volume transfer constant (Ktrans). Favorable calibration and discrimination of 10-miRNA RS-based model with areas under the curve (AUC) of 0.865, 0.811, and 0.804 were shown in the training, internal, and external validation sets, respectively. Patients who have higher nomogram score (>92.2) with NAC treatment would have longer DFS (hazard ratio=0.57; 95%CI: 0.39-0.83; P=0.004). In summary, our data showed the 10-miRNA RS-based model could precisely identify more patients who can attain pCR to NAC, which may help clinicians formulate the personalized initial treatment strategy and consequently achieves better clinical prognosis for patients with HR-positive breast cancer.

Autophagy-associated circRNA circCDYL augments autophagy and promotes breast cancer progression.

BACKGROUND: Although both circular RNAs (circRNAs) and autophagy are associated with the function of breast cancer (BC), whether circRNAs regulate BC progression via autophagy remains unknown. In this study, we aim to explore the regulatory mechanisms and the clinical significance of autophagy-associated circRNAs in BC. METHODS: Autophagy associated circRNAs were screened by circRNAs deep sequencing and validated by qRT-PCR in BC tissues with high- and low- autophagic level. The biological function of autophagy associated circRNAs were assessed by plate colony formation, cell viability, transwells, flow cytometry and orthotopic animal models. For mechanistic study, RNA immunoprecipitation, circRNAs pull-down, Dual luciferase report assay, Western Blot, Immunofluorescence and Immunohistochemical staining were performed. RESULTS: An autophagy associated circRNA circCDYL was elevated by 3.2 folds in BC tissues as compared with the adjacent non-cancerous tissues, and circCDYL promoted autophagic level in BC cells via the miR-1275-ATG7/ULK1 axis; Moreover, circCDYL enhanced the malignant progression of BC cells in vitro and in vivo. Clinically, increased circCDYL in the tumor tissues and serum of BC patients was associated with higher tumor burden, shorter survival and poorer clinical response to therapy. CONCLUSIONS: circCDYL promotes BC progression via the miR-1275-ATG7/ULK1-autophagic axis and circCDYL could act as a potential prognostic and predictive molecule for breast cancer patients.

Construction of an immune-related genes nomogram for the preoperative prediction of axillary lymph node metastasis in triple-negative breast cancer.

Immune system disorder is associated with metastasis of triple-negative breast cancers (TNBCs). A robust, individualized immune-related genes (IRGs)-based classifier was aimed to develop and validate in our study to precisely estimate the axillary lymph node (ALN) status preoperatively in patients with early-stage TNBC. We first analyzed RNA sequencing profiles in TNBC patients from The Cancer Genome Atlas database by using bioinformatics approaches, and screened 23 differentially expressed IRGs. A 9-gene panel was generated with an area under the curve (AUC) of 0.77 [95% confidence interval (95% CI), 0.68-0.87]. We detected the 9 ALN-status-related IRGs in the training set (n = 133) and developed a reduced and optimized five-IRGs signature, which effectively distinguished TNBC patients with ALN metastasis (AUC, 0.80; 95% CI, 0.65-0.86), and was superior to preoperative ultrasound-based ALN status (AUC, 0.73; 95% CI, 0.53-0.93). Predictive efficiency (AUC, 0.77; 95% CI 0.61-0.93) of this five-IRGs signature was validated in the validation set (n = 81). Furthermore, IRGs nomogram incorporated IRGs signature with US-based ALN status showed higher ALN status prediction efficacy than US-based ALN status and five-IRGs signature alone in both training and validation sets. IRGs nomogram may aid in identifying patients who can be exempted from axillary surgery.Novelty and impact: An immune-related genes (IRGs) nomogram was first developed and externally validated in our study, which incorporated the IRGs signature with ultrasound (US)-based axillary lymph nodes (ALN) status. IRGs nomogram is superior to IRGs signature alone for preoperative estimation of ALN metastasis in patients with triple-negative breast cancer (TNBC). It is a favourable biomarker for preoperatively predicting ALN metastasis risk and may aid in clinical decision-making in early-stage TNBCs.

Incorporating MicroRNA into Molecular Phenotypes of Circulating Tumor Cells Enhances the Prognostic Accuracy for Patients with Metastatic Breast Cancer.

BACKGROUND: The molecular phenotype of circulating tumor cells (CTCs) was associated with clinical outcome of patients with breast cancer. CTCs isolated from patients with metastatic breast cancer (MBC) display a unique microRNA (miRNA) expression profile. The aim of this study was to enhance the prognostic accuracy of the CTC phenotype in patients with MBC, by incorporating miRNA into a combined prediction model. SUBJECTS, MATERIALS, AND METHODS: CTCs were detected by CellSearch and enriched by magnetic cell sorting. miRNA deep sequencing and quantitative polymerase chain reaction were used to screen and verify potentially CTC-specific miRNA candidates. Patients with MBC were enrolled from two independent cohorts, and overall survival (OS) and chemotherapy response were analyzed. RESULTS: We screened and identified that miR-106b was an upregulated molecule in patients with MBC with CTC ≥5/7.5 mL (n = 16) compared with patients with CTC = 0/7.5 mL (n = 16) and healthy donors (n = 8). The expression of CTC-specific miR-106b correlated with vimentin and E-cadherin in CTC and acted as an independent factor for predicting OS (hazard ratio 2.157, 95% confidence interval [CI] 1.098-4.239, p = .026). Although CTC-specific miR-106b, E-cadherin, and vimentin showed a prognostic potential independently, the prognostic performance for OS based on the combination of three markers was significantly enhanced in Cohort 1 (area under the curve [AUC] 0.752, 95% CI 0.658-0.847, n = 128) and further validated in Cohort 2 (AUC 0.726, 95% CI 0.595-0.856, n = 91). Besides, a combined model incorporating miR-106b was associated with therapy response. CONCLUSION: The phenotypic assemblies of CTC incorporating miR-106b show enhanced prognostic accuracy of overall survival in patients with MBC. IMPLICATIONS FOR PRACTICE: In order to enhance the prognostic accuracy of the circulating tumor cell (CTC) phenotype in patients with metastatic breast cancer (MBC), this study screened and identified a CTC-specific microRNA (miRNA), miR-106b, as an upregulated molecule based on the comparison of miRNA profile between CTCs, primary tumors, and healthy blood donors. By incorporating miR-106b into a combined prediction model, the prognostic accuracy of the CTC phenotype for patients with MBC was greatly improved in both the training and validation cohorts. This work provides clinical evidence supporting the prognostic potential of CTC-specific miRNA for patients with MBC. These results indicate that developing CTC-specific miRNAs as new biomarkers will help to further optimize personalized therapy.

Metformin mediates induction of miR-708 to inhibit self-renewal and chemoresistance of breast cancer stem cells through targeting CD47.

Breast cancer stem cells (BCSCs) have been considered responsible for cancer progression, recurrence, metastasis and drug resistance. However, the mechanisms by which cells acquire self-renewal and chemoresistance properties are remaining largely unclear. Herein, we evaluated the role of miR-708 and metformin in BCSCs, and found that the expression of miR-708 is significantly down-regulated in BCSCs and tumour tissues, and correlates with chemotherapy response and prognosis. Moreover, miR-708 markedly inhibits sphere formation, CD44+ /CD24- ratio, and tumour initiation and increases chemosensitivity of BCSCs. Mechanistically, miR-708 directly binds to cluster of differentiation 47 (CD47), and regulates tumour-associated macrophage-mediated phagocytosis. On the other hand, CD47 is essential for self-renewal, tumour initiation and chemoresistance of BCSCs, and correlates with the prognosis of breast cancer patients. In addition, the anti-type II diabetes drug metformin are found to be involved in the miR-708/CD47 signalling pathway. Therefore, our study demonstrated that miR-708 plays an important tumour suppressor role in BCSCs self-renewal and chemoresistance, and the miR-708/CD47 regulatory axis may represent a novel therapeutic mechanism of metformin in BCSCs.

BCL11A enhances stemness and promotes progression by activating Wnt/ß-catenin signaling in breast cancer.

Background: Breast cancer has become the most common malignant disease threatening women's health. The cancer stem cell (CSC) has been recognized as a small subpopulation of cancer cells possesses stem cell properties, which is crucial in tumorigenicity, tumor invasion, drug resistance, and metastasis. The BCL11A plays a crucial role in breast cancer progression. To investigate the effect of BCL11A, a functional oncogene, we focused on its maintenance ability of stemness in breast cancer stem cells. Methods: We assessed the BCL11A expression level in tumor and non-tumor tissues using RT-qPCR and IHC. We subsequently established BCL11A-modulating breast cancer cell lines MDA-MB-231 and MCF-7. CCK8, colony formation assays, and xenograft model were used to determine the effect of BCL11A on tumorigenicity. Transwell assay and lung metastasis model in vivo were conducted to validate its function in metastasis. Its effect on stemness was assessed by flow cytometry and mammosphere formation. Western blot further characterized the importance of Wnt/ß-catenin signaling in BCL11A-regulated cancer cell stemness. Results: A higher level of BCL11A was detected in clinical breast cancer samples. BCL11A promoted tumor formation, cancer cell mobility, spheroid forming, and epithelial-mesenchymal transition by activating the Wnt/ß-catenin signaling. In addition, BCL11A was associated with lung metastasis and increased the breast cancer cells stemness. BCL11A high expression (BCL11Ahigh) cancer cells exhibited stem cell-like properties compared with BCL11Alow cells, including a higher percentage of CD24low/CD44high subpopulation, self-renewal spheroids formation, and higher tumorigenicity. Our studies demonstrated that the Wnt/ß-catenin signaling activated by BCL11A plays a potential role in the initiation of the renewal of breast cancer stem cells. Conclusions: BCL11A not only functions in breast cancer carcinogenesis but also enhanced the stemness of breast cancer through activating Wnt/ß-catenin signaling, and may become a potential target for breast cancer treatment.

Oncologic outcomes and radiation safety of nipple-sparing mastectomy with intraoperative radiotherapy for breast cancer.

BACKGROUND: Nipple-sparing mastectomy combined with breast reconstruction helps to optimize the contour of the breast after mastectomy. However, the indications for nipple-sparing mastectomy are still controversial. Local radiation to the nipple-areola complex may play some roles in improving the oncological safety of this procedure. METHODS: From January 2014 to December 2017, 41 consecutive patients who underwent nipple-sparing mastectomy combined with Intrabeam intraoperative radiotherapy to the nipple-areola complex flap and breast reconstruction were enrolled in this prospective study. The prescribed radiation dose at the surface of the spherical applicator was 16 Gy. RESULTS: In eight cases, carcinomas were in the central portion of the breast. Partial necrosis of the nipple-areola complex occurred in three cases. Over 90% of patients reported "no or poor sensation" of the nipple-areola complex postoperatively. With a median follow-up time of 26 months, no recurrences or metastases were identified; however, breast-cancer mortality occurred in one patient. Pathologic evaluation of paraffin-embedded sections showed ductal carcinoma in situ in the remaining tissues deep to the nipple-areola complex flap in two patients. Although no further treatment was administered to the nipple-areola complexes postoperatively, no recurrences or metastases were identified 20 months and 24 months later, respectively. Optical microscopy and transmission electron microscopy revealed changes in some normal tissues immediately after Intrabeam intraoperative radiotherapy. Karyopyknosis were observed in gland tissues, and the collagenous fibers became sparse and arranged chaotically. As assessed by thermoluminescence, radiation doses at different sites in the nipple-areola complex flap varied considerably and were about 10 Gy at the areola surface. No Intrabeam intraoperative radiotherapy-related acute or chronic radiation injuries of the lung, heart or bone marrow were identified. CONCLUSIONS: Our findings indicate that Intrabeam intraoperative radiotherapy during nipple-sparing mastectomy combined with breast reconstruction is safe and feasible. TRIAL REGISTRATION: The current study was approved by the Ethics Committee of the First Affiliated Hospital of Guangzhou Medical University (registering order 201750). All participants gave their written informed consent.

circEPSTI1 regulates ovarian cancer progression via decoying miR-942.

Increasing studies show that circular RNAs (circRNAs) play vital roles in tumour progression. But, how circRNAs function in ovarian cancer is mostly unclear. Here, we detected the expression of circEPSTI1 in ovarian cancer and explored the function of circEPSTI1 in ovarian cancer via a series of experiments. Then, we performed luciferase assay and RNA immunoprecipitation (RIP) assay to explore the competing endogenous RNA (ceRNA) function of circEPSTI1 in ovarian cancer. qRT-PCR verified that circEPSTI1 was overexpressed in ovarian cancer. Inhibition of circEPSTI1 suppressed ovarian cancer cell proliferation, invasion but promoted cell apoptosis. Luciferase assays and RIP assay showed that circEPSTI1 and EPSTI1 (epithelial stromal interaction 1) could directly bind to miR-942. And circEPSTI1 could regulate EPSTI1 expression via sponging miR-942. In summary, circEPSTI1 regulated EPSTI1 expression and ovarian cancer progression by sponging miR-942. circEPSTI1 could be used as a biomarker and therapeutic target in ovarian cancer.

miR-145-5p Suppresses Breast Cancer Progression by Inhibiting SOX2.

BACKGROUND: In this study, we aimed to investigate the expression and clinical significance of miR-145-5p and its tumor-suppressive effect in breast cancer patients. METHODS: We used luciferase reporter assay, real-time quantitative reverse transcription polymerase chain reaction and Western blot to identify sex-determining region Y-box2 (SOX2) as the target gene of miR-145-5p. Their expression levels in breast cancer tissues (n = 122) were detected by real-time quantitative polymerase chain reaction. We also applied 3-(4,5-dimethyl- 2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay and flow cytometry to reveal the effect of miR-145-5p on proliferation in breast cancer. RESULTS: miR-145-5p expression is downregulated in breast cancer tissues and negatively correlated with SOX2 expression. Decreased miR-145-5p expression was significantly associated with larger tumor size, distal metastasis, higher Ki67 expression level, and shorter overall survival. miR-145-5p inhibits breast cancer cell proliferation via targeting SOX2, and multivariate regression showed that both miR-145-5p and SOX2 were unfavorable prognostic factors. CONCLUSIONS: miR-145-5p played a suppressive role in the proliferation of breast cancer cells by targeting SOX2, and miR-145-5p is a putative biomarker for risk assessment in patients with breast cancer.

Circular RNA hsa_circ_001783 regulates breast cancer progression via sponging miR-200c-3p.

Increasing evidence suggests circular RNAs (circRNAs) exert critical functions in tumor progression via sponging miRNAs (microRNAs). However, the role of circRNAs in breast cancer remains unclear. Here we systematically analyzed the circular RNAs in breast cancer based on their characteristic in sponging disease-specific miRNAs and identified hsa_circ_001783 as a top ranked circRNA in our computation and verified its high expression in both breast cancer cells and cancer tissue. A higher level of hsa_circ_001783 was significantly correlated with heavier tumor burden and poorer prognosis of patients with breast cancer. Knockdown of this circRNA remarkably inhibited the proliferation and invasion of breast cancer cells. Importantly, hsa_circ_001783 promoted progression of breast cancer cells via sponging miR-200c-3p. Taken together, hsa_circ_001783 may serve as a novel prognostic and therapeutic target for breast cancer.

MicroRNAs and cancer: Key paradigms in molecular therapy.

MicroRNAs (miRNAs) are a type of small non-coding RNA molecule that performs an important role in post-transcriptional gene regulation. Since miRNAs were first identified in 1993, a number of studies have demonstrated that they act as tumor suppressors or oncogenes in human cancer, including colorectal, lung, brain, breast and liver cancer, and leukemia. Large high-throughput studies have previously revealed that miRNA profiling is critical for the diagnosis and prognosis of patients with cancer, while certain miRNAs possess the potential to be used as diagnostic and prognostic biomarkers or therapeutic targets in cancer. The present study reviews the studies and examines the roles of miRNAs in cancer diagnosis, prognosis and treatment, and discusses the potential therapeutic modality of exploiting miRNAs.

Preoperative prediction nomogram based on primary tumor miRNAs signature and clinical-related features for axillary lymph node metastasis in early-stage invasive breast cancer.

More than half patients who undergo axillary lymph node (ALN) surgery are ALN negative in early-stage invasive breast cancer (EIBC). Thus, to avoid excessive treatment, we aim to establish and validate a novel nomogram model for the preoperative diagnosis of ALN status in patients with EIBC. In total, 864 patients with EIBC from two independent centers were enrolled in our study. For the discovery set, miRNAs expression profiling with functional roles in ALN metastasis was discovered by microarray analysis and validated by quantitative polymerase chain reaction (PCR). For the training and validation cohorts, we used PCR to quantify miRNAs expression in a model development cohort and assessed miRNAs signature in an internal validation cohort and external independent validation cohort. Multivariable logistic regression analyses were used to establish a nomogram model for the likelihood of ALN metastasis from miRNAs signature and clinical variables. A signature of nine-miRNA was significantly associated with ALN status. The predictive ability of our nomogram that included miRNAs signature and clinical-related variables (age, tumor size, tumor location and axillary ultrasound-reported ALN status) was significantly greater than a model that only considered clinical-related factors (concordance index: 0.856, 0.796) and also performed well in the two validation cohorts (concordance index: 0.841, 0.747). Our nomogram is a reliable prediction method that can be conveniently used to preoperatively predict ALN status in patients with EIBC. Therefore, after further confirmation in prospective and multicenter clinical trial, omission of axillary surgery may be feasible for some patients with EIBC in the future.

A combination of Nottingham prognostic index and IHC4 score predicts pathological complete response of neoadjuvant chemotherapy in estrogen receptor positive breast cancer.

Pathologic complete response (pCR) prediction after neoadjuvant chemotherapy (NAC) is important for clinical decision-making in breast cancer. This study investigated the predictive value of Nottingham prognostic index (NPI), Immunohistochemical four (IHC4) score and a new predictive index combined with them in estrogen-positive (ER+) breast cancer following NAC. We retrospectively gathered clinical data of 739 ER+ breast cancer patients who received NAC from two cancer centers. We developed a new predictive biomarker named NPI+IHC4 to predict pCR in ER+ breast cancer in a training set (n=443) and validated it in an external validation set (n=296). The results showed that a lower IHC4 score, NPI and NPI+IHC4 were significantly associated a high pCR rate in the entire cohort. In the study set, NPI+IHC4 showed a better sensitivity and specificity for pCR prediction (AUC 0.699, 95% CI 0.626-0.772) than IHC4 score (AUC 0.613, 95% CI 0.533-0.692), NPI (AUC 0.576, 95% CI 0.494-0.659), tumor size (AUC 0.556, 95% CI 0.481-0.631) and TNM stage (AUC 0.521, 95% CI 0.442-0.601). In the validation set, NPI+IHC4 had a better predictive value for pCR (AUC 0.665, 95% CI 0.579-0.751) than IHC4 score or NPI alone. In addition, ER+ patients with lower IHC4, NPI and NPI+IHC4 scores had significantly better DFS in both study and validation sets. In summary, NPI+IHC4 can predict pCR following NAC and prognosis in ER+ breast cancer, which is cost-effect and potentially more useful in guiding decision-making regarding NAC in clinical practice. Further validation is needed in prospective clinical trials with larger cohorts of patients.

Diagnostic and prognostic value of serum MACC1 in breast cancer patients.

Metastasis-associated in colon cancer-1 (MACC1) promotes colorectal cancer progression and predicts prognosis. The aim of our study was to determine the diagnostic and prognostic value of preoperative serum MACC1 levels in breast cancer patients. Serum MACC1 levels were measured in 378 breast cancer patients, 120 patients with benign breast disease, and 40 healthy volunteers using an ELISA. Serum MACC1 levels were higher in breast cancer patients than patients with benign disease or healthy volunteers. Increased serum MACC1 was associated with breast cancer TNM stage (P < 0.001), tumor size (P < 0.001), lymph node metastasis (P < 0.001), and Ki-67 status (P = 0.014). Serum MACC1 measurement successfully discriminated breast cancer patients from normal and healthy controls (AUC = 0.785, 95% CI: 0.746-0.825) with an optimal cut-off value of 38.35 pg/ml (sensitivity = 0.725, specificity = 0.696). Moreover, serum MACC1 exhibited significant prognostic value in breast cancer (AUC = 0.757, 95% CI: 0.700-0.814), and high MACC1 was associated with poor disease-free survival (HR 5.63, 95% CI: 3.51-9.04; P < 0.001). Our findings demonstrated that circulating MACC1 could serve as a reliable diagnostic and prognostic biomarker for breast cancer.

Prognostic Value of a BCSC-associated MicroRNA Signature in Hormone Receptor-Positive HER2-Negative Breast Cancer.

PURPOSE: Breast cancer patients with high proportion of cancer stem cells (BCSCs) have unfavorable clinical outcomes. MicroRNAs (miRNAs) regulate key features of BCSCs. We hypothesized that a biology-driven model based on BCSC-associated miRNAs could predict prognosis for the most common subtype, hormone receptor (HR)-positive, HER2-negative breast cancer patients. PATIENTS AND METHODS: After screening candidate miRNAs based on literature review and a pilot study, we built a miRNA-based classifier using LASSO Cox regression method in the training group (n=202) and validated its prognostic accuracy in an internal (n=101) and two external validation groups (n=308). RESULTS: In this multicenter study, a 10-miRNA classifier incorporating miR-21, miR-30c, miR-181a, miR-181c, miR-125b, miR-7, miR-200a, miR-135b, miR-22 and miR-200c was developed to predict distant relapse free survival (DRFS). With this classifier, HR+HER2- patients were scored and classified into high-risk and low-risk disease recurrence, which was significantly associated with 5-year DRFS of the patients. Moreover, this classifier outperformed traditional clinicopathological risk factors, IHC4 scoring and 21-gene Recurrence Score (RS). The patients with high-risk recurrence determined by this classifier benefit more from chemotherapy. CONCLUSIONS: Our 10-miRNA-based classifier provides a reliable prognostic model for disease recurrence in HR+HER2- breast cancer patients. This model may facilitate personalized therapy-decision making for HR+HER2- individuals.

Estrogen receptor beta as a prognostic factor in breast cancer patients: A systematic review and meta-analysis.

BACKGROUND: The prognostic role of estrogen receptor beta (ERß) in early-stage breast cancer is unclear. We performed a systematic review and meta-analysis to evaluate the prognostic value of ERß in early-stage breast cancer patients. METHOD: We searched Medline, Embase, and the Web of Science for studies published between 1990 and 2015 that assessed ERß status in breast cancer patients. A total of 25 studies comprising 9919 patients fitting our inclusion and exclusion criteria were included. The hazard ratios of ERß status were extracted for diseases free survival (DFS)/ ) and overall survival (OS). Random or fixed-effects models were used when appropriate, and between-study heterogeneity was assessed. RESULTS: In the 20 studies that assessed ERß status using immunohistochemical (IHC) methods, we observed significantly improved DFS in patients positive for ERß-1 (HR=0.56, 95%CI 0.40-0.78, P=0.0007) and ERß-2 (HR=0.67, 95%CI 0.45-1.00, P=0.05). Improved OS was associated with a positive status for pan-ERß (HR=0.60, 95%CI 0.45-0.80, P=0.0004) and ERß-2 (HR=0.44, 95%CI 0.31-0.62, P<0.0001). In ERα-positive patients, ERß positivity was not associated with DFS (HR=0.77, 95%CI 0.46-1.27, P=0.31) or OS (HR=0.64, 95%CI 0.37-1.11, P=0.11). In contrast, ERß expression was significantly associated with increased DFS (HR=0.37, 95%CI 0.14-0.93, P=0.03) or OS (HR=0.44, 95%CI 0.30-0.65, P<0.0001) in ERα-negative patients. We did not observe an association between ERß mRNA levels and DFS and OS. CONCLUSION: In this study, we showed that IHC ERß status, rather than mRNA levels, is a prognostic factor that is associated with DFS and OS in breast cancer patients. The prognostic value of ERß may be higher in ERα-negative patients than in ERα-positive patients.

Potentiated DNA Damage Response in Circulating Breast Tumor Cells Confers Resistance to Chemotherapy.

Circulating tumor cells (CTCs) are seeds for cancer metastasis and are predictive of poor prognosis in breast cancer patients. Whether CTCs and primary tumor cells (PTCs) respond to chemotherapy differently is not known. Here, we show that CTCs of breast cancer are more resistant to chemotherapy than PTCs because of potentiated DNA repair. Surprisingly, the chemoresistance of CTCs was recapitulated in PTCs when they were detached from the extracellular matrix. Detachment of PTCs increased the levels of reactive oxygen species and partially activated the DNA damage checkpoint, converting PTCs to a CTC-like state. Inhibition of checkpoint kinases Chk1 and Chk2 in CTCs reduces the basal checkpoint response and sensitizes CTCs to DNA damage in vitro and in mouse xenografts. Our results suggest that DNA damage checkpoint inhibitors may benefit the chemotherapy of breast cancer patients by suppressing the chemoresistance of CTCs and reducing the risk of cancer metastasis.