GAS5 regulated by FTO-mediated m6A modification suppresses cell proliferation via the IGF2BP2/QKI axis in breast cancer.

BACKGROUND: The lncRNA growth arrest-specific 5 (GAS5) is involved in regulating breast cancer progression. In this study, we aimed to elucidate the function and mechanism of GAS5 in breast cancer. METHODS: The expressions of GAS5, fat mass and obesity-associated protein (FTO), insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), and Quaking (QKI) were assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot. The m6A modification level of GAS5 was detected using m6A immunoprecipitation assay (MeRIP). The interaction between IGF2BP2 and GAS5 or QKI was detected using RNA immunoprecipitation assay (RIP) and dual luciferase reporter assay. Cell proliferation was measured using the Cell Counting Kit-8 (CCK-8) assay. The biological functions of the FTO/GAS5/IGF2BP2/QKI axis was assessed using the tumor xenograft assay. RESULTS: LncRNA GAS5 expression decreased in breast cancer and was regulated by FTO-mediated m6A modification in an IGF2BP2-dependent manner, resulting in decreased GAS5 stability and expression. GAS5 recruited IGF2BP2 to target QKI and upregulated QKI expression in breast cancer cells. GAS5 suppressed breast cancer growth via IGF2BP2/QKI, and this inhibitory effect was modulated by FTO both in vitro and in vivo. CONCLUSIONS: GAS5 regulated by FTO-mediated m6A modification represses the growth of breast cancer via the IGF2BP2/QKI pathway, suggesting that the FTO/GAS5/IGF2BP2/QKI pathway can be a potential target for breast cancer treatment.

A novel twelve-gene signature to predict neoadjuvant chemotherapy response and prognosis in breast cancer.

Background: Accurate evaluation of the response to neoadjuvant chemotherapy (NAC) provides important information about systemic therapies for breast cancer, which implies pharmacological response, prognosis, and guide further therapy. Gene profiles overcome the shortcomings of the relatively limited detection indicators of the classical pathological evaluation criteria and the subjectivity of observation, but are complicated and expensive. Therefore, it is essential to develop a more accurate, repeatable, and economical evaluation approach for neoadjuvant chemotherapy responses. Methods: We analyzed the transcriptional profiles of chemo-resistant breast cancer cell lines and tumors of chemo-resistant breast cancer patients in the GSE25066 dataset. We preliminarily screened out common significantly differentially expressed genes and constructed a NAC response risk model using LASSO regression and univariate and multivariate analyses. The differences in bioinformatic features of tumor cells, immune characteristics, and prognosis were compared between high and low-risk group. The potential drugs that could reverse chemotherapy resistance in breast cancer were screened by the CMap database. Results: Thirty-six genes were commonly up/down-regulated in both NAC chemo-resistant tumors and cells compared to the sensitive tumors and wild-type cells. Through LASSO regression, we obtained a risk model composed of 12 genes. The risk model divided patients into high and low-risk groups. Univariate and multivariate Cox regression analyses suggested that the risk score is an independent prognostic factor for evaluating NAC response in breast cancer. Tumors in risk groups exhibited significant differences in molecular biological characteristics, tumor-infiltrating lymphocytes, and immunosuppressive molecule expression. Our results suggested that the risk score was also a good prognostic factor for breast cancer. Finally, we screened potential drugs that could reverse chemotherapy resistance in breast cancer. Conclusion: A novel 12 gene-signature could be used to predict NAC response and predict prognosis in breast cancer.

Huaier polysaccharides suppress triple-negative breast cancer metastasis and epithelial-mesenchymal transition by inducing autophagic degradation of Snail.

BACKGROUND: Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, and the targeted therapies are lacking for this type of cancer. We previously demonstrated that Huaier effectively improve 5-year OS and DFS in stage III TNBC patients, and the polysaccharides of Huaier (PS-T) have been identified as the major components of Huaier. However, the mechanisms of anti-tumor action of PS-T is unclear. This study aimed to investigate the effect of PS-T on TNBC cell invasion and migration. RESULTS: This study showed that PS-T inhibited cell invasion and migration both in vitro and in vivo by inducing autophagy to suppress epithelial-mesenchymal transition (EMT). Autophagy inhibitor LY294002 or knockdown of ATG5 suppressed the inhibitory effects of PS-T. In addition, as a key transcription factor controlling EMT initiation, Snail was found to be degraded by PS-T induced autophagy. In addition, overexpression of Snail reversed the inhibitory effects of PS-T. Furthermore, it was confirmed that the expression of Snail was inversely correlated with LC3 and associated with poor prognosis using immunohistochemistry and TCGA database analysis, respectively. CONCLUSIONS: This study demonstrated that PS-T could inhibit EMT in breast cancer cells by inducing autophagy to degrade Snail protein, thus improving the prognosis of TNBC, offering potential treatment alternatives for TNBC patients.

m6A RNA Methylation Regulator YTHDF1 Correlated With Immune Microenvironment Predicts Clinical Outcomes and Therapeutic Efficacy in Breast Cancer.

Objective: Increasing evidence highlights the roles of N6-methyladenosine (m6A) and its regulators in oncogenesis. Herein, this study observed the associations of m6A regulators with breast cancer. Methods: RNA-seq profiles of breast cancer were retrieved from the Cancer Genome Atlas (TCGA) database. The expression of m6A regulators was analyzed in tumor and normal tissues. Their expression correlations were analyzed by Spearson test. Overall survival (OS) analysis of these regulators was then presented. Gene set enrichment analysis (GSEA) was performed in high and low YTHDF1 expression groups. The correlations of YTHDF1 expression with immune cells and tumor mutation burden (TMB) were calculated in breast cancer samples. Somatic variation was assessed in high and low YTHDF1 expression groups. Results: Most of m6A regulators were abnormally expressed in breast cancer compared to normal tissues. At the mRNA levels, there were closely relationships between them. Among them, YTHDF1 up-regulation was significantly related to undesirable prognosis (p = 0.025). GSEA results showed that high YTHDF1 expression was associated with cancer-related pathways. Furthermore, YTHDF1 expression was significantly correlated with T cells CD4 memory activated, NK cells activated, monocytes, and macrophages. There were higher TMB scores in YTHDF1 up-regulation group than its down-regulation group. Missense mutation and non-sense mutation were the most frequent mutation types. Conclusion: Our findings suggested that dysregulated m6A regulator YTHDF1 was predictive of survival outcomes as well as response to immunotherapy of breast cancer, and were closely related to immune microenvironment.

Speed Sensorless Control of Linear Ultrasonic Motors Based on Stator Vibration Amplitude Compensation.

In some applications of linear ultrasonic motors (LUSMs), not installing speed/position sensors can reduce the size and cost of the system, changes in load will cause fluctuations in the speed of the LUSM. To eliminate the influence of load changes on speed, a speed sensorless control scheme based on stator vibration amplitude compensation (SSCBVC) is proposed. This scheme is implemented under the framework of the stator vibration amplitude-based speed control (VBSC) and frequency tracking. Based on the stator vibration amplitude-speed and the output force-speed curves of the LUSM, the relationship between the load changes and stator vibration amplitude (SVA) to be compensated is established, realizing a speed sensorless control of the LUSM under variable load conditions. The experimental results show that the maximum fluctuation of the speed is about 2.2% when the output force changes from 0 to 6 N with SSCBVC. This scheme can effectively reduce the influence of load changes on the speed of the LUSM without using speed/position sensors.

Supraclavicular lymph node dissection with radiotherapy versus radiotherapy alone for operable breast cancer with synchronous ipsilateral supraclavicular lymph node metastases: a real-world cohort study.

BACKGROUND: The role of supraclavicular lymph node dissection (SCLD) in the treatment of breast cancer with ipsilateral supraclavicular lymph node metastasis (ISLM) remains controversial. We evaluated the role of SCLD in the treatment of breast cancer with ISLM and identified patients who may benefit from SCLD. METHODS: Data on patients presenting with breast cancer to the Breast Disease Center, Southwest Hospital, The Army Medical University from January 2004 and December 2017 were retrospectively screened. The median duration of follow-up was 36 months (2-175 months). 305 patients who were recently diagnosed with ISLM were eligible for the analysis. RESULTS: Overall, 9,236 women presented with breast cancer during the study period. Among the patients included, 146 and 159 received SCLD with radiotherapy (RT) and RT alone, respectively. Synchronous ISLM without distant metastases were present in 3.6% cases. The 3- and 5-year overall survival (OS) and disease-free survival (DFS) rates were 79.5% and 73.9%, respectively, and 67.5% and 54.8%, respectively. However, SCLD with RT was not associated with superior survival on both univariate and multivariate analyses. On stratified analyses, patients with non-luminal A tumors with 4-9 positive axillary lymph nodes who underwent SCLD with RT had both superior OS (HR =5.296; 95% CI: 1.857-15.107; P=0.001) and DFS (HR =5.331; 95% CI: 2.348-12.108; P<0.001) compared with those who received RT alone. CONCLUSIONS: SCLD may not beneficial in improving survival for unselected breast cancer patients with ISLNM. There is less of a tendency to perform SCLD in the luminal A group.

[GPER silence inhibits the stimulation of growth and inhibition of apoptosis induced by tamoxifen in breast cancer-associated fibroblasts].

OBJECTIVE: To construct a lentiviral vector (Lenti-GPER-shRNA) targeting G-protein coupled estrogen receptor (GPER) and explore the role of GPER in the effect of tamoxifen on cell proliferation and apoptosis in breast cancer associated fibroblasts (BCAFs). METHODS: The target sequence of GPER gene and negative control were cloned into lentiviral vectors. The recombinant lentivirus and control were extracted after HEK293T cells were transfected with the recombinant vector and helper vectors. After infection of BCAFs with the GPER lentiviral vector under the best interfering condition, GPER expression was detected by real-time quantitative PCR and Western blotting. BCAFs were divided into negative control group, GPER-RNAi group, negative control combined with tamoxifen (10(-8) mmol/L) group and GPER-RNAi combined with tamoxifen (10(-8) mmol/L) group. CCK-8 assay was used to detect the proliferation and annexin V-fluorescein isothiocyanate/propidium iodide (annexin V-FITC/PI) combined with flow cytometry was used to detect the apoptosis of BCAFs after the treatment of tamoxifen. RESULTS: Lenti-GPER-shRNA significantly interfered the expression of GPER in BCAFs. Tamoxifen promoted the growth of BCAFs, which could be attenuated by knockdown of GPER. Moreover, the apoptosis of BCAFs was reduced by tamoxifen, which was also reversed by knockdown of GPER. CONCLUSION: Lenti-GPER-shRNA could effectively silence the GPER expression in BCAFs. The ability of tamoxifen to accelerate cell proliferation and decrease cell apoptosis could be weakened by knockdown of GPER.

GPER mediates enhanced cell viability and motility via non-genomic signaling induced by 17ß-estradiol in triple-negative breast cancer cells.

Triple-negative breast cancer (TNBC) is an aggressive breast cancer with a generally poor prognosis. Due to lack of specific targets for its treatment, an efficient therapy is needed. G protein-coupled estrogen receptor (GPER), a novel estrogen receptor, has been reported to be expressed in TNBC tissues. In this study, we investigated the effects of blocking non-genomic signaling mediated by the estrogen/GPER pathway on cell viability and motility in the TNBC cells. GPER was strongly expressed in the TNBC cell lines MDA-MB-468 and MDA-MB-436, and the estrogen-mediated non-genomic ERK signaling activated by GPER was involved in cell viability and motility of TNBC cells. Treatment with 17ß-estradiol (E2), the GPER-specific agonist G-1 and tamoxifen (TAM) led to rapid activation of p-ERK1/2, but not p-Akt. Moreover, estrogen/GPER/ERK signaling was involved in increasing cell growth, survival, and migration/invasion by upregulating expression of cyclinA, cyclinD1, Bcl-2, and c-fos associated with the cell cycle, proliferation, and apoptosis. Immunohistochemical analysis of TNBC specimens showed a significantly different staining of p-ERK1/2 between GPER-positive tissues (58/66, 87.9%) and GPER-negative tissues (13/30, 43.3%). The positivity of GPER and p-ERK1/2 displayed a strong association with large tumor size and poor clinical stage, indicating that GPER/ERK signaling might also contribute to tumor progression in TNBC patients which corresponded with in vitro experimental data. Our findings suggest that inhibition of estrogen/GPER/ERK signaling represents a novel targeted therapy in TNBC.