Exosomal microRNA-92b Is a Diagnostic Biomarker in Breast Cancer and Targets Survival-Related MTSS1L to Promote Tumorigenesis.

Exosomal microRNAs (miRNAs) are novel, non-invasive biomarkers for facilitating communication and diagnosing cancer. However, only a few studies have investigated their function and role in the clinical diagnosis of breast cancer. To address this gap, we established a stable cell line, MDA-MB-231-CD63-RFP, and recruited 112 female participants for serum collection. We screened 88 exosomal miRNAs identified through microarray analysis of 231-CD63 and literature screening using real-time PCR; only exosomal miR-92b-5p was significantly increased in patients with breast cancer. It had a significant correlation with stage and discriminated patients from the control with an AUC of 0.787. Exosomal miR-92b-5p impacted the migration, adhesion, and spreading ability of normal human mammary epithelial recipient cells through the downregulation of the actin dynamics regulator MTSS1L. In clinical breast cancer tissue, the expression of MTSS1L was significantly inversely correlated with tissue miR-92b-5p, and high expression of MTSS1L was associated with better 10-year overall survival rates in patients undergoing hormone therapy. In summary, our studies demonstrated that exosomal miR-92b-5p might function as a non-invasive body fluid biomarker for breast cancer detection and provide a novel therapeutic strategy in the axis of miR-92b-5p to MTSS1L for controlling metastasis and improving patient survival.

Correlation of Beta2-Glycoprotein I With Tumor Prognosis in Breast Cancer Patients.

BACKGROUND/AIM: Beta2-glycoprotein I (ß2-GPI) is a plasma glycoprotein, which has been implicated in a variety of physiological functions. However, the connection between ß2-GPI and breast cancer is mostly unknown. Breast cancer is a malignant tumor that severely impairs women's health worldwide. The aim of the study was to investigate the role of ß2-GPI in tumor cells of breast cancer patients and its correlation with tumor prognosis. MATERIALS AND METHODS: A total of 125 female patients diagnosed with breast cancer were enrolled in the study. The expression of ß2-GPI in resected breast tissues was determined by immunohistochemistry (IHC) and correlated with clinicopathological variables by the Chi-squared test. The prognostic value of ß2-GPI for overall survival (OS) and disease-free survival (DFS) was determined by Kaplan-Meier estimates and the significance of differences was evaluated by the log-rank test. RESULTS: ß2-GPI staining was predominantly observed in tumor cells of breast cancer patients and significantly correlated with tumor stage and lymph node metastasis of breast cancer. High ß2-GPI expression was significantly correlated with better OS and DFS. Moreover, DFS was found to be significantly better in patients with higher ß2-GPI expression, especially those in the early tumor stage groups. CONCLUSION: High ß2-GPI expression levels in tumor cells of breast cancer patients were independent factors predicting a better OS and DFS. ß2-GPI activation in high-risk patients may be a potential strategy for reducing breast cancer progression.

Comprehensive Transcriptomic and Proteomic Analyses Identify a Candidate Gene Set in Cross-Resistance for Endocrine Therapy in Breast Cancer.

Endocrine therapy (ET) of selective estrogen receptor modulators (SERMs), selective estrogen receptor downregulators (SERDs), and aromatase inhibitors (AIs) has been used as the gold standard treatment for hormone-receptor-positive (HR+) breast cancer. Despite its clinical benefits, approximately 30% of patients develop ET resistance, which remains a major clinical challenge in patients with HR+ breast cancer. The mechanisms of ET resistance mainly focus on mutations in the ER and related pathways; however, other targets still exist from ligand-independent ER reactivation. Moreover, mutations in the ER that confer resistance to SERMs or AIs seldom appear in SERDs. To date, little research has been conducted to identify a critical target that appears in both SERMs/SERDs and AIs. In this study, we conducted comprehensive transcriptomic and proteomic analyses from two cohorts of The Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA) to identify the critical targets for both SERMs/SERDs and AIs of ET resistance. From a treatment response cohort with treatment response for the initial ET regimen and an endocrine therapy cohort with survival outcomes, we identified candidate gene sets that appeared in both SERMs/SERDs and AIs of ET resistance. The candidate gene sets successfully differentiated progress/resistant groups (PD) from complete response groups (CR) and were significantly correlated with survival outcomes in both cohorts. In summary, this study provides valuable clinical implications for the critical roles played by candidate gene sets in the diagnosis, mechanism, and therapeutic strategy for both SERMs/SERDs and AIs of ET resistance for the future.

MOAI: a multi-outcome interaction identification approach reveals an interaction between vaspin and carcinoembryonic antigen on colorectal cancer prognosis.

Identifying and characterizing the interaction between risk factors for multiple outcomes (multi-outcome interaction) has been one of the greatest challenges faced by complex multifactorial diseases. However, the existing approaches have several limitations in identifying the multi-outcome interaction. To address this issue, we proposed a multi-outcome interaction identification approach called MOAI. MOAI was motivated by the limitations of estimating the interaction simultaneously occurring in multi-outcomes and by the success of Pareto set filter operator for identifying multi-outcome interaction. MOAI permits the identification for the interaction of multiple outcomes and is applicable in population-based study designs. Our experimental results exhibited that the existing approaches are not effectively used to identify the multi-outcome interaction, whereas MOAI obviously exhibited superior performance in identifying multi-outcome interaction. We applied MOAI to identify the interaction between risk factors for colorectal cancer (CRC) in both metastases and mortality prognostic outcomes. An interaction between vaspin and carcinoembryonic antigen (CEA) was found, and the interaction indicated that patients with CRC characterized by higher vaspin (≥30%) and CEA (≥5) levels could simultaneously increase both metastases and mortality risk. The immunostaining evidence revealed that determined multi-outcome interaction could effectively identify the difference between non-metastases/survived and metastases/deceased patients, which offers multi-prognostic outcome risk estimation for CRC. To our knowledge, this is the first report of a multi-outcome interaction associated with a complex multifactorial disease. MOAI is freely available at https://sites.google.com/view/moaitool/home.

The impact of age group in breast cancer survival outcome according to neoadjuvant treatment response: A matched case-control study.

This study aimed to investigate the effectiveness of neoadjuvant chemotherapy in patients with breast cancer in different age groups and evaluate the impact of age group on survival outcome according to different treatment responses. Data were retrospectively collected from the cancer registry database of Kaohsiung Medical University Hospital in Taiwan under an approved protocol. Overall, 96 elder patients (aged >50 years) and 96 younger controls (aged ≤50 years) who received neoadjuvant chemotherapy and breast surgical treatment were examined after 1:1 matching. Logistic regression analysis was used to investigate the effectiveness of treatment response in patients of different age groups. Additionally, the Kaplan-Meier estimator and log-rank test were performed to evaluate the effect of age group and treatment response on disease-free and overall survival (OS). Although no direct significant association was found between age group and treatment response, several significant results were found in treatment response stratification analysis. Among 16 pathological complete response (pCR) patients, elder patients showed significantly greater 5-year disease-free survival (DFS) than younger patients (DFS rate, 85.7% vs. 0%, p = 0.041). However, in 176 non-pCR patients, elder patients showed poor DFS compared to younger patients (DFS rate, 16.6% vs. 32.3%; log-rank test, p = 0.031). With limited sample size and study design, our study results demonstrate that patients aged >50 years who achieved pCR after neoadjuvant chemotherapy could obtain better survival outcome than younger patients. However, the younger patients showed no survival benefits regardless of pCR status.

DEHP mediates drug resistance by directly targeting AhR in human breast cancer.

Resistance to chemotherapy and hormonal therapy is a major clinical problem in breast cancer medicine, especially for cancer metastasis and recurrence. Di(2-ethylhexyl)phthalate (DEHP) affects drug resistance by an unknown mechanism of action. Here we analyzed breast cancer patients (N = 457) and found that Σ4MEHP (the sum of MEHP, MEHHP, MECPP and MEOHP concentrations) in urine was significantly higher (P = 0.018) in the recurrent breast cancer group compared with non-recurrent patients. Σ4MEHP-High was positively and significantly correlated with tumor stage (P = 0.005), lymph node status (P = 0.001), estrogen receptor status (P = 0.010), Her2/Neu status (P = 0.004), recurrence (P = 0.000) and tumor size (P = 0.002), as well as an independent prognostic marker (OR = 1.868; 95% CI = 1.424-2.451; P < 0.000) associated with poor survival rates based on a positive Her2/Neu status (P = 0.035). In addition, we found that DEHP inhibited paclitaxel and doxorubicin effects in breast cancer cell lines MCF-7 and MDA-MB-231 and in zebrafish and mouse tumor initiation models. DEHP induced trefoil factor 3 (TFF3) expression through the vinculin/aryl hydrocarbon receptor (AhR)/ERK signaling pathway and induced CYP2D6, CYP2C8 and CYP3A4 expression through the AhR genomic pathway to increase the epithelial-mesenchymal transition (EMT) and doxorubicin metabolism, respectably. DEHP mediated AhR-related alterations in estrogen receptor expression through the ubiquitination system, which decreased tamoxifen effects in AhR knockout mice. These findings suggest a novel therapeutic avenue by targeting AhR in drug-resistant and recurrent breast cancer.

Correction: Pan et al. Impact of FAK Expression on the Cytotoxic Effects of CIK Therapy in Triple-Negative Breast Cancer. Cancers 2020, 12, 94.

In the original article [...].

Utilizing NPWT improving skin graft taking in reconstruction for extended breast skin defects following mastectomy.

NPWT fulfill graft taking in complex breast wounds.

Comprehensive profiles and diagnostic value of menopausal-specific gut microbiota in premenopausal breast cancer.

In Western countries, breast cancer tends to occur in older postmenopausal women. However, in Asian countries, the proportion of younger premenopausal breast cancer patients is increasing. Increasing evidence suggests that the gut microbiota plays a critical role in breast cancer. However, studies on the gut microbiota in the context of breast cancer have mainly focused on postmenopausal breast cancer. Little is known about the gut microbiota in the context of premenopausal breast cancer. This study aimed to comprehensively explore the gut microbial profiles, diagnostic value, and functional pathways in premenopausal breast cancer patients. Here, we analyzed 267 breast cancer patients with different menopausal statuses and age-matched female controls. The α-diversity was significantly reduced in premenopausal breast cancer patients, and the ß-diversity differed significantly between breast cancer patients and controls. By performing multiple analyses and classification, 14 microbial markers were identified in the different menopausal statuses of breast cancer. Bacteroides fragilis was specifically found in young women of premenopausal statuses and Klebsiella pneumoniae in older women of postmenopausal statuses. In addition, menopausal-specific microbial markers could exhibit excellent discriminatory ability in distinguishing breast cancer patients from controls. Finally, the functional pathways differed between breast cancer patients and controls. Our findings provide the first evidence that the gut microbiota in premenopausal breast cancer patients differs from that in postmenopausal breast cancer patients and shed light on menopausal-specific microbial markers for diagnosis and investigation, ultimately providing a noninvasive approach for breast cancer detection and a novel strategy for preventing premenopausal breast cancer.

Simultaneous hyperbaric oxygen therapy during systemic chemotherapy reverses chemotherapy-induced peripheral neuropathy by inhibiting TLR4 and TRPV1 activation in the central and peripheral nervous system.

BACKGROUND AND OBJECTIVES: Chemotherapy-induced peripheral neuropathy (CIPN) is considered one of the most common sequelae in patients with cancer who experience consistent abnormal sensations or pain symptoms during or after paclitaxel (PAC) chemotherapy. Transient receptor potential vanilloid 1 (TRPV1) and toll-like receptor 4 (TLR4) have been reported to interact in the nervous system in patients with CIPN. The antinociceptive effects of hyperbaric oxygen therapy (HBOT) on CIPN was demonstrated in this study through behavior tests. Using a CIPN rat model, we examined the effects of simultaneous HBOT (SHBOT) administration during chemotherapy and discovered that SHBOT achieved better reversal effects than chemotherapy alone. MATERIALS AND METHODS: Twenty-four rats were randomly allocated to four groups: control, PAC, SHBOT, and HBOT after PAC groups. Behavior tests were performed to evaluate mechanical allodynia and thermal hyperalgesia status. Tissues from the spinal cord and dorsal root ganglions were collected, and TLR4 and TRPV1 expression and microglial activation were investigated through immunofluorescence (IF) staining. RESULTS: The mechanical and thermal behavior tests revealed that HBOT intervention during PAC treatment led to the early alleviation of CIPN symptoms and inhibited CIPN deterioration. IF staining revealed that TLR4, TRPV1, and microglial activation were all upregulated in PAC-injected rats and exhibited early and significant downregulation in SHBOT-treated rats. CONCLUSION: This study is the first to demonstrate that the use of SHBOT during PAC treatment has potential for the early suppression of CIPN initiation and deterioration, indicating that it can alleviate CIPN symptoms and may reverse CIPN in patients undergoing systemic chemotherapy.

Comprehensive Transcriptomic Analysis Identifies ST8SIA1 as a Survival-Related Sialyltransferase Gene in Breast Cancer.

Hypersialylation caused by the overexpression of sialyltransferases (STs) is a common feature in cancer that is associated with several characteristics of tumorigenesis. Thus, identifying cancer-associated STs is critical for cancer therapy. However, ST screening has been frequently conducted in cell line models. In this study, we conducted a comprehensive analysis of STs in the clinical database and identified the STs related with the survival of breast cancer patients. RNA sequencing (RNA-Seq) data of 496 patients were obtained from The Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA). Of the eight mapped STs, ST3GAL5, and ST8SIA1 met the acceptable area under the curve (AUC) criteria for overall survival (OS). Using Kaplan-Meier methods, we determined that high expression of ST8SIA1 was associated with poor 10-year OS in all patients, triple-negative breast cancer (TNBC), and non-TNBC patients, and poor disease-free survival (DFS) rates particularly in TNBC. ST8SIA1 also had superior AUC values in terms of OS/DFS. High ST8SIA1 levels showed a higher risk for poor OS in different groups of patients and a higher risk for poor DFS particularly in TNBC. In summary, we conducted a comprehensive analysis of STs from the clinical database and identified ST8SIA1 as a crucial survival-related ST, which might be a potential therapeutic target for breast cancer and TNBC patients.

Effect of Baseline Characteristics and Tumor Burden on Vaspin Expression and Progressive Disease in Operable Colorectal Cancer.

Colorectal cancer is a highly heterogeneous malignancy in the Asian population, and it is considered an important prognostic factor for baseline characteristics, tumor burden, and tumor markers. This study investigated the effect of baseline characteristics and tumor burden on tumor marker expression and progressive disease in colorectal cancer by using partial least squares variance-based path modeling (PLS-PM). PLS-PM can be used to evaluate the complex relationship between prognostic variables and progressive disease status with a small sample of measurements and structural models. A total of 89 tissue samples of colorectal cancer were analyzed. Our results suggested that the expression of visceral adipose tissue-derived serpin (vaspin) is a potential indicator of colorectal cancer progression and may be affected by baseline characteristics such as age, sex, body mass index, and diabetes mellitus. Moreover, according to the characteristics of tumor burden, the expression of vaspin was generally higher in each progressive disease patient. The overall findings suggest that vaspin is a potential indicator of the progressive disease and may be affected by the baseline characteristics of patients.

Activation of mitochondrial unfolded protein response is associated with Her2-overexpression breast cancer.

PURPOSE: Mitochondrial unfolding protein are abundant in breast cancer cells, but the mechanism by which breast cancer cells resist apoptosis is still not fully elucidated. In this study, we explored the role of mitochondrial unfolded protein response (mtUPR)-related proteins in four types of breast cancer tissues. METHODS: Mitochondrial fractions were taken from four breast cancer tissues (luminal A, luminal B, Her2 -overexpression, and TNBC) and the expression of mitochondrial polyubiquitinated proteins was observed by western blot and ELISA. In addition, the expression of hsp10, hsp60, and clpp in mitochondria was observed by western blot in breast cancer tissues and adjacent tissues, and confirmed by ELISA. The expression levels of hsp10 and hsp60 were correlated with clinicopathological parameters in 114 breast cancer patients. RESULTS: We found an increase in the performance of mitochondrial polyubiquitinated proteins in breast cancer tissues of luminal A, luminal B, Her2-overexpression, and TNBC. The mitochondrial hsp10, hsp60, and clpp are abundantly expressed in breast cancer tissues rather than adjacent noncancerous tissues. The expression levels of mitochondrial hsp10 and hsp60 were highest in histological grade 3 breast cancer tissues. Additionally, mitochondria with high hsp60 expression were more present in Her2-positive tumors. CONCLUSIONS: We observed that mtUPR was specifically activated in breast cancer tissues but inactivated in normal mammary tissue. MtUPR had also exhibited a particular increase in Her2-overexpression tumors but not in ER- or PR-positive tumors. Taken together, we suggested that mtUPR may act as a potential candidate for developing novel Her2-overexpression breast cancer therapy.

Cost-effectiveness of stereotactic vacuum-assisted biopsy for nonpalpable breast lesions.

PURPOSE: To examine the potential cost-savings of stereotactic vacuum-assisted biopsy (SVAB) over open surgical biopsy (OSB) in diagnosis of nonpalpable lesions on mammography and to estimate the cost-saving effect on lesions at different levels of malignant probability. METHODS: This retrospective study was approved by our Institutional Review Board. We retrospectively reviewed 276 (33.8 %) SVAB and 541 (66.2 %) OSB medical records at a medical center. Direct costs included patients' self-paid and national health insurance claim charges. Indirect costs were calculated using sick days, average salary, and age-adjusted employment rate. One-way and two-way sensitivity analyses were conducted. Lesion classification was determined by the assessment categories of Breast Imaging Reporting and Data System (BI-RADS), 4th or 5th editions. RESULTS: SVAB decreased the direct cost by $90.3 (10.1 %) per diagnosis. The indirect cost was decreased by $560.2 (96.0 %). Overall, SVAB saved 43.9 % of resource utilization for each biopsy. Taking the cost of the subsequent malignant surgery into account, from the healthcare providers' perspective, SVAB was cost-effective if a lesion had less than 19 % likelihood of malignancy. From the societal perspective, SVAB reduced productivity loss for all the lesions. Based on the positive predictive value of the BI-RADS categories, SVAB was more suitable for the lesions of category 4A and category 3, resulting in greater savings in both medical and societal resources. CONCLUSIONS: SVAB is a cost-effective diagnostic option for nonpalpable breast lesions. The cost-saving effect is greater for the lesions of category 4A and category 3.

Green Tea Catechin (-)-Epigallocatechin-3-Gallate (EGCG) Facilitates Fracture Healing.

Green tea drinking can ameliorate postmenopausal osteoporosis by increasing the bone mineral density. (-)-Epigallocatechin-3-gallate (EGCG), the abundant and active compound of tea catechin, was proven to be able to reduce bone loss and ameliorate microarchitecture in female ovariectomized rats. EGCG can also enhance the osteogenic differentiation of murine bone marrow mesenchymal stem cells and inhibit the osteoclastogenesis in RAW264.7 cells by modulation of the receptor activator of nuclear factor-kB (RANK)/RANK ligand (RANKL)/osteoprotegrin (OPG) (RANK/RANKL/OPG) pathway. Our previous study also found that EGCG can promote bone defect healing in the distal femur partially via bone morphogenetic protein-2 (BMP-2). Considering the osteoinduction property of BMP-2, we hypothesized that EGCG could accelerate the bone healing process with an increased expression of BMP-2. In this manuscript, we studied whether the local use of EGCG can facilitate tibial fracture healing. Fifty-six 4-month-old rats were randomly assigned to two groups after being weight-matched: a control group with vehicle treatment (Ctrl) and a study group with 10 µmol/L, 40 µL, EGCG treatment (EGCG). Two days after the operation, the rats were treated daily with EGCG or vehicle by percutaneous local injection for 2 weeks. The application of EGCG enhanced callus formation by increasing the bone volume and subsequently improved the mechanical properties of the tibial bone, including the maximal load, break load, stiffness, and Young's modulus. The results of the histology and BMP-2 immunohistochemistry staining showed that EGCG treatment accelerated the bone matrix formation and produced a stronger expression of BMP-2. Taken together, this study for the first time demonstrated that local treatment of EGCG can accelerate the fracture healing process at least partly via BMP-2.

Accuracy and outcomes of stereotactic vacuum-assisted breast biopsy for diagnosis and management of nonpalpable breast lesions.

Stereotactic vacuum-assisted biopsy (SVAB) is an alternative method of breast biopsy for nonpalpable lesions detected by mammography. Considering the diagnostic effectiveness, a direct comparison of SVAB and open surgical biopsy (OSB) is lacking. We performed a retrospective review of 276 (33.8%) SVAB and 541 (66.2%) OSB to compare the diagnostic accuracy and the total number of procedures the patients underwent. The negative predictive values of OSB and SVAB were 99.77% and 99.61%, and their false-negative rates were 0.96% and 4.76%, respectively. SVAB, as the first-line biopsy method, obviated 92.3% of operations. All malignancies diagnosed using SVAB could be treated with single therapeutic surgery. By contrast, 48% of malignancies of OSB group received two operations. Breast Imaging Reporting and Data System (BI-RADS) category used at the study correlated well with the percentage of malignancy and can thus be used to predict biopsy results. Our study concluded that SVAB is reliable for diagnosing nonpalpable breast lesions and is the better biopsy method for categories 3 and 4A lesions, which reduces the benign surgery rate. For lesions with a higher likelihood of malignancy, BI-RADS 4B, 4C and 5, SVAB has an advantage over OSB, which lowers the total number of operations for malignancy treatment.

New Insight on Solute Carrier Family 27 Member 6 (SLC27A6) in Tumoral and Non-Tumoral Breast Cells.

Long-chain fatty acids are the most abundant fatty acids and are essential for various physiological processes. Translocation of long-chain fatty acids across cell membrane is dependent on transport proteins. Solute carrier family 27 member 6 (SLC27A6) is a transport protein which mediates long-chain fatty acid uptake. The bioinformatic analysis revealed that the expression of SLC27A6 in non-tumoral breast tissue was higher than that in tumoral breast cancer in clinic samples. When SLC27A6 expression in non-tumorigenic cell H184B5F5/M10 was repressed, the fatty acids uptake capacity and cell proliferation was inhibited, and cell cycle was delayed. The protein expression of cell cycle regulators including cell division protein kinase 4 (CDK4), CDK6, and cyclin D1 was significantly decreased in SLC27A6-silenced H184B5F5/M10. By contrast, relatively low SLC27A6 expression in tumorigenic breast cancer cell Hs578T when compared to H184B5F5/M10. Repressing SLC27A6 expression did not affect these phenotypes in Hs578T. The interaction network of SLC27A6 was further investigated via STRING database. The function of these SLC27A6-associated proteins mainly involved in lipid biosynthesis, fatty acid metabolic process, and fatty acid transport. In conclusion, this study reveals inverse correlation between SLC27A6 expression and tumoral tissues and provides a new insight into SLC27A6-mediated cell growth and cell cycle regulation in non-tumorigenic breast cells.

Impact of FAK Expression on the Cytotoxic Effects of CIK Therapy in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is a special subtype of breast cancer in which several common diagnostic biomarkers are lost. Due to the loss of expression of receptors, treatment options for TNBC are limited. Therefore, finding safe and effective treatments for patients with TNBC is a major objective for clinicians. Previous studies suggested that cytokine-induced killer (CIK) cells may be beneficial for patients with a variety of tumor types. However, CIK therapy is not effective for all patients. In this study, we found that focal adhesion kinase (FAK), a non-receptor protein tyrosine kinase that regulates several cellular functions in different cells, has the potential to regulate tumor cells sensitized to CIK cells. Knockdown of FAK expression in TNBC cells or the treatment of TNBC cells with a FAK inhibitor followed by coculture with CIK cells increases death of TNBC cells, suggesting that FAK plays important roles in sensitizing tumor cells to CIK cells. This phenomenon could be regulated by a FAK-programmed death-ligand 1 (PD-L1)-related mechanism. Overall, our findings provide new insights into the cytotoxic effect of CIK cell therapy in TNBC treatment, and show that CIK cell therapy combined with FAK inhibitors may be a novel therapeutic strategy for patients with TNBC.

Solute Carrier Family 27 Member 4 (SLC27A4) Enhances Cell Growth, Migration, and Invasion in Breast Cancer Cells.

Fatty acid metabolism is important in the regulation of breast cancer progression. Some of the proteins involved in fatty acid transport have been demonstrated to promote the proliferation, migration, and invasion in breast cancer cells. Solute carrier family 27 member 4 (SLC27A4) is a fatty acid transporter protein and is related to very long chain acyl-CoA synthetase activity. In the present study, bioinformatic analysis revealed that relatively high SLC27A4 expression was observed in all subtypes of breast tumor tissues when compared to normal breast tissues. Silencing SLC27A4 expression significantly reduced uptake of free fatty acids in two breast cancer cell lines, Hs578T and MDA-MB-231. Cell growth inhibition was observed in SLC27A4-silenced Hs578T and cell cycle was arrested at G2/M. In addition, the capacity of migration and invasion decreased in both cell lines after knockdown of SLC27A4. The epithelial⁻mesenchymal transition signaling pathway was inhibited because protein expression of Slug, vimentin, α-smooth muscle actin, and other regulators was lower than that in control cells. Taken together, our results confirm that high SLC27A4 is associated with tumor progression in breast cancer cells. It is worth investigating whether SLC27A4 serves a diagnostic marker and therapeutic target in further studies.

Breast cancer is associated with methylation and expression of the a disintegrin and metalloproteinase domain 33 (ADAM33) gene affected by endocrine­disrupting chemicals.

A disintegrin and metalloproteinase domain 33 (ADAM33) gene is a transmembrane glycoprotein that mediates changes in cell adhesion and plays an important role in cancer progression. Since bisphenol A (BPA) and phthalates are epigenetically toxic, the purpose of this study was to examine whether BPA and phthalate metabolites, including monoethyl phthalate (MEP), mono­n­butyl phthalate (MBP), mono­isobutyl phthalate (MIBP), mono(2­ethylhexyl) phthalate (MEHP), mono(2­ethyl­5­hydroxyhexyl) phthalate (MEHHP), mono(2­ethyl­5­carboxypentyl) phthalate (MECPP), and mono(2­ethyl­5­oxohexyl) phthalate (MEOHP), have an epigenetic impact on ADAM33 and the incidence of breast cancer. CpG islands of breast cancer microarray datasets obtained from the Gene Expression Omnibus (GEO) were used to assess the ADAM33 methylation profile. We designed a case­control study including 44 cases and 22 age­matched controls to detect the methylation status of intron 1 in ADAM33 from peripheral blood mononuclear cells (PBMCs) in blood, using BSP, nested PCR, and bisulfite sequencing, and measured the in vivo gene expression of ADAM33 and the urinary concentrations of endocrine­disrupting chemicals (EDCs), using real­time PCR, high­performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC­MS). Only one dataset, GSE32393, reached significance (P=0.016). ADAM33 expression and methylation frequencies at CpG site 3 in intron 1 were higher in the control group. We found a positive association between intron 1 methylation level and ADAM33 expression as well as urinary concentrations of MEHHP, MECPP, MEOHP and Σ4MEHP (the sum of MEHP, MECPP, MEHHP, and MEOHP) in the cases. This study suggests that metabolites of phthalate such as MEHHP, MECPP, MEOHP and Σ4MEHP may increase the intron 1 methylation level to elevate ADAM33 gene expression and have a protective effect on reducing the risk of breast cancer.