Invasion Of MCF-7 Cells Research Articles

Activation of TMEM16A Ca2+-activated Cl− channels by ROCK1/moesin promotes breast cancer metastasis

IntroductionTransmembrane protein 16A (TMEM16A) is a Ca2+-activated chloride channel that plays a role in cancer cell proliferation, migration, invasion, and metastasis. However, whether TMEM16A contributes to breast cancer metastasis remains unknown. ObjectiveIn this study, we investigated whether TMEM16A channel activation by ROCK1/moesin promotes breast cancer metastasis. MethodsWound healing assays and transwell migration and invasion assays were performed to study the migration and invasion of MCF-7 and T47D breast cancer cells. Western blotting was performed to evaluate the protein expression, and whole-cell patch clamp recordings were used to record TMEM16A Cl− currents. A mouse model of breast cancer lung metastasis was generated by injecting MCF-7 cells via the tail vein. Metastatic nodules in the lung were assessed by hematoxylin and eosin staining. Lymph node metastasis, overall survival, and metastasis-free survival of breast cancer patients were assessed using immunohistochemistry and The Cancer Genome Atlas dataset. ResultsTMEM16A activation promoted breast cancer cell migration and invasion in vitro as well as breast cancer metastasis in mice. Patients with breast cancer who had higher TMEM16A levels showed greater lymph node metastasis and shorter survival. Mechanistically, TMEM16A promoted migration and invasion by activating EGFR/STAT3/ROCK1 signaling, and the role of the TMEM16A channel activity was important in this respect. ROCK1 activation by RhoA enhanced the TMEM16A channel activity via the phosphorylation of moesin at T558. The cooperative action of TMEM16A and ROCK1 was supported through clinical findings indicating that breast cancer patients with high levels of TMEM16A/ROCK1 expression showed greater lymph node metastasis and poor survival. ConclusionOur findings revealed a novel mechanism underlying TMEM16A-mediated breast cancer metastasis, in which ROCK1 increased TMEM16A channel activity via moesin phosphorylation and the increase in TMEM16A channel activities promoted cell migration and invasion. TMEM16A inhibition may be a novel strategy for treating breast cancer metastasis.

The Effect of Piperine on MMP-9, VEGF, and E-cadherin Expression in Breast Cancer MCF-7 Cell Line

Background: Vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), and E-cadherin play a vital role in the behavior of angiogenesis, metastasis, and invasion of breast tumor cells. Piperine, the main component of Piper Nigrum, has shown anti-cancer properties in various malignancies. This Study investigates the potential effect of piperine on MMP-9, E-cadherin, and VEGF expression in breast cancer MCF-7 cell line. Methods: MTT assay was applied to assess the viability of MCF-7 cells. The mRNA levels of MMP-9, VEGF, and E-cadherin were assayed by qRT-PCR. Western blot was performed to identify the protein level of MMP-9. Results: MTT assay results showed that piperine treatment (5, 10, 25, 50, 75, and 100 μM) for 24 hours effectively inhibited cell viability of MCF-7 cells as compared with the control group. Furthermore, the gene expression of VEGF, MMP-9, and E-cadherin was dose-dependently suppressed by piperine treatment (5, 10 and 25 μM) (P<0.05; P<0.01). The results also indicated that piperine (5, 10, and 25 μM) significantly suppressed MMP-9 protein expression after 24 hours of piperine treatment (P<0.01). Conclusion: These results suggest that piperine may prevent angiogenesis, migration, and invasion of MCF-7 cells by suppressing MMP-9 and VEGF, and by inducing E-cadherin expression. Hence, it may be a suitable candidate for designing new drugs in cancer therapy.

Oxidized Phospholipids in Tumor Microenvironment Stimulate Tumor Metastasis via Regulation of Autophagy.

Oxidized phospholipids are well known to play physiological and pathological roles in regulating cellular homeostasis and disease progression. However, their role in cancer metastasis has not been entirely understood. In this study, effects of oxidized phosphatidylcholines such as 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC) on epithelial-mesenchymal transition (EMT) and autophagy were determined in cancer cells by immunoblotting and confocal analysis. Metastasis was analyzed by a scratch wound assay and a transwell migration/invasion assay. The concentrations of POVPC and 1-palmitoyl-2-glutaroyl-sn-glycero-phosphocholine (PGPC) in tumor tissues obtained from patients were measured by LC-MS/MS analysis. POVPC induced EMT, resulting in increase of migration and invasion of human hepatocellular carcinoma cells (HepG2) and human breast cancer cells (MCF7). POVPC induced autophagic flux through AMPK-mTOR pathway. Pharmacological inhibition or siRNA knockdown of autophagy decreased migration and invasion of POVPC-treated HepG2 and MCF7 cells. POVPC and PGPC levels were greatly increased at stage II of patient-derived intrahepatic cholangiocarcinoma tissues. PGPC levels were higher in malignant breast tumor tissues than in adjacent nontumor tissues. The results show that oxidized phosphatidylcholines increase metastatic potential of cancer cells by promoting EMT, mediated through autophagy. These suggest the positive regulatory role of oxidized phospholipids accumulated in tumor microenvironment in the regulation of tumorigenesis and metastasis.

Cadmium promotes breast cancer cell proliferation, migration and invasion by inhibiting ACSS2/ATG5-mediated autophagy.

Cadmium (Cd), which is considered a carcinogenic metal, promotes breast cancer (BC) progression, but the precise mechanism remains unclear. Herein, MCF-7 and T47-D cells were treated with 0.1, 1, and 10μM cadmium chloride (CdCl2) for 24, 48 and 72h. In our study, Cd exposure significantly accelerated the proliferation, migration and invasion of MCF-7 and T47-D cells. Notably, Cd inhibited autophagic flux by suppressing ATG5-dependent autophagosome formation but had no significant effect on autophagosome-lysosome fusion and lysosomal function. The genetic enhancement of autophagy through ATG5 overexpression suppressed the Cd-mediated increases in proliferation, migration and invasion, which indicated a carcinogenic role of autophagy impairment in Cd-exposed BC cells. GSEA and GeneMANIA were utilized to demonstrate that the Cd-induced decrease in ACSS2 expression mechanistically inhibited ATG5-dependent autophagy in BC cells. Importantly, ACSS2 overexpression increased the level of H3K27 acetylation in the promoter region of ATG5, and this result maintained autophagic flux and abolished the Cd-induced increases in proliferation, migration and invasion. We also verified that the expression of ACSS2 in BC tissues was low and positively related to ATG5 expression. These findings indicated that the promoting effect of Cd on BC cell proliferation, migration and invasion through the impairment of ACSS2/ATG5-dependent autophagic flux suggests a new mechanism for BC cell proliferation and metastasis stimulated by Cd.

Circular RNA circPRMT5 is upregulated in breast cancer and is required for cell proliferation and migration

To evaluate the role of cyclic protein arginine methyltransferase 5 (circPRMT5) in the occurrence and development of breast cancer (BC). A total of 90 BC patients who underwent radical mastectomy and 40 age-matched healthy female controls were recruited in the Second People's Hospital of China Three Gorges University, Yichang Second People's Hospital from 2017 to 2020. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to detect the expression levels of circPRMT5 in BC tissues, serum, normal breast cell line (MCF-10A) and BC cell line (T47D, MCF-7, BT549, Hs-578T and MDA-MB-231, MDA-MB-468). The associations between circPRMT5 expression level and age, tumor size, degree of differentiation, TNM stage, distant metastasis, estrogen receptor (ER) or progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status were analyzed. BC cell lines with circPRMT5 knockdown or overexpression were subject to CCK-8 cell proliferation assay, and transwell cell invasion/migration assay. CircPRMT5 expression in BC tissue was higher than that in adjacent normal breast tissue. Consistently, the expression level of circPRMT5 was also elevated in serum samples collected from BC patients when compared with healthy controls. And in multiple breast cancer cell lines, circPRMT5 was upregulated as compared to normal breast epithelial MCF-10A cells. CircPRMT5 expression level was correlated with tumor size, TNM stage, lymph node metastasis distant metastasis, but no correlation was observed with ER, PR, HER2 status. Overexpression of circPRMT5 promoted the proliferation, invasion and migration of MCF7 cells; while the knockdown of circPRMT5 inhibited cell proliferation, invasion and migration. CircPRMT5 seems to act as an oncogene in the progression of BC. Our data suggest that CircPRMT5 may be used as a biomarker for the diagnosis, prognosis evaluation and targeted therapy of breast cancer.

Paclitaxel inhibits proliferation and invasion and promotes apoptosis of breast cancer cells by blocking activation of the PI3K/AKT signaling pathway.

Breast cancer has the highest incidence and mortality among all cancers in women. Paclitaxel (PTX) has a notable therapeutic effect on cancer in clinical practice. To explore the effect and mechanism of PTX on the proliferation, apoptosis and invasiveness of breast cancer cells. MCF-7 cells were treated with PTX (0 μM, 0.01 μM, 0.1 μM, 1 μM) for 48 h. Cell viability was detected using MTT assay and lactate dehydrogenase (LDH) assay; the cell proliferation rate was detected using 5-ethynyl-2'-deoxyuridine (EdU) assay to screen the most effective concentration of PTX. MCF-7 cells were then divided into 5 groups: control group, PTX group, oe-PI3K group, NC-PI3K group, and oe-PI3K+PTX group. Cell apoptosis and cell cycles were detected with flow cytometry; cell invasion was determined using a transwell assay; western blot and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) were used to measure the mRNA and protein expression level of cleaved caspase-3, Bax, Bcl-2, matrix metalloproteinase 9 (MMP-9), vascular endothelial growth factor (VEGF), p-AKT (Thr308), and p-AKT (Ser473). Paclitaxel inhibited cell viability and proliferation in a dose-dependent manner. In the PTX group, the apoptosis rate, the number of cells arrested in the G2/M phase and the expression levels of Cleaved caspase-3 and Bax were increased, but the number of invasive cells and the expression levels of Bcl-2, MMP-9, vascular endothelial growth factor (VEGF), p-AKT (Thr308), and p-AKT (Ser473) were decreased. However, PI3K upregulation can reverse the effects of PTX. Paclitaxel could inhibit MCF-7 cell proliferation and invasion, and promote MCF-7 cell apoptosis by downregulating the expression of p-AKT (Thr308) and p-AKT (Ser473) in the PI3K/AKT signaling pathway.

The miR-5694/AF9/Snail Axis Provides Metastatic Advantages and a Therapeutic Target in Basal-like Breast Cancer

Epigenetic deregulation, especially mutagenesis or the abnormal expression of epigenetic regulatory factors (ERFs), plays an important role in malignant tumorigenesis. To screen natural inhibitors of breast cancer metastasis, we adopted small interfering RNAs (siRNAs) to transiently knock down 591 ERF-coding genes in luminal breast cancer MCF-7 cells and found that depletion of AF9 significantly promoted MCF-7 cell invasion and migration. A mouse model of metastasis further confirmed the suppressive role of AF9 in breast cancer metastasis. RNA profiling revealed enrichment of AF9 targets genes in the epithelial-mesenchymal transition (EMT). Mechanistically, tandem mass spectrometry showed that AF9 interacts with Snail, which hampers Snail transcriptional activity in basal-like breast cancer (BLBC) cells. AF9 reconstitutes an activated state on the promoter of Snail, which is a master regulator of EMT, and derepresses genes by recruiting CBP or GCN5. Additionally, microRNA-5694 (miR-5694) targeted and degraded AF9 messenger RNA (mRNA) in BLBC cells, further enhancing cell invasion and migration. Notably, AF9 and miR-5694 expression in BLBC clinical samples correlated inversely. Hence, miR-5694 mediates downregulation of AF9 and provides metastatic advantages in BLBC. Restoring expression of the metastasis suppressor AF9 is a possible therapeutic strategy against metastatic breast cancer.

Long non-coding RNA TMPO-AS1 promotes tumor progression via sponging miR-140-5p in breast cancer.

Long non-coding RNAs (lncRNAs) are involved in carcinogenesis and tumor suppression, and are novel biological tumor regulators. However, the functional roles of lncRNAs and their underlying dysregulation mechanisms in breast cancer are not completely understood. The aim of the present study was to investigate the clinical significance and biological functions of lncRNA TMPO antisense RNA 1 (TMPO-AS1) in breast cancer. TMPO-AS1 levels were measured in human cancer tissues and breast cancer cell lines, and the functional roles of TMPO-AS1 in breast cancer cells were investigated by performing in vitro and in vivo assays. Additionally, luciferase reporter assays were conducted to detect the association between microRNA (miR)-140-5p and TMPO-AS1. TMPO-AS1 expression levels were significantly increased in breast cancer tissues and cell lines compared with adjacent non-cancerous tissues and MCF-10A cells, respectively. In vitro and in vivo studies indicated that TMPO-AS1 knockdown significantly suppressed breast cancer cell viability at 48 and 72 h compared with the small interfering (si)RNA negative control group (NC; siNC). TMPO-AS1 knockdown in vitro inhibited MCF-7 and T47D cell migration and invasion compared with the siNC group. TMPO-AS1 knockdown in metastatic breast cancer cells also decreased metastatic colonization in the mouse lung compared with the short hairpin RNA NC group. Mechanistically, TMPO-AS1 promoted cellular viability and migration as a competing endogenous RNA by sponging miR-140-5p. The results suggested that TMPO-AS1 may serve as a potential therapeutic target in patients with breast cancer.

Tryptanthrin exerts anti-breast cancer effects both in vitro and in vivo through modulating the inflammatory tumor microenvironment.

Tryptanthrin is an indole quinazoline alkaloid from the indigo-bearing plants, such as Isatis indigotica Fort. Typically, this natural compound shows a variety of pharmacological activities such as antitumor, antibacterial, anti-inflammatory and antioxidant effects. This study was conducted to assess the antitumor activity of tryptanthrin in breast cancer models both in vitro and in vivo, and to explore the important role of the inflammatory tumor microenvironment (TME) in the antitumor effects of tryptanthrin. Human breast adenocarcinoma MCF-7 cells were used to assess the antitumor effect of tryptanthrin in vitro. MTT assay and colony formation assay were carried out to monitor the antiproliferative effect of tryptanthrin (1.56~50.0 μmol L-1) on inhibiting the proliferation and colony formation of MCF-7 cells, respectively. The migration and invasion of MCF-7 cells were evaluated by wound healing assay and Transwell chamber assay, respectively. Moreover, the 4T1 murine breast cancer model was established to examine the pharmacological activity of tryptanthrin, and three groups with different doses of tryptanthrin (25, 50 and 100 mg kg-1) were set in study. Additionally, tumor volumes and organ coefficients were measured and calculated. After two weeks of tryptanthrin treatment, samples from serum, tumor tissue and different organs from tumor-bearing mice were collected, and the enzyme-linked immunosorbent assay (ELISA) was performed to assess the regulation of inflammatory molecules in mouse serum. Additionally, pathological examinations of tumor tissues and organs from mice were evaluated through hematoxylin and eosin (H&E) staining. The expression of inflammatory proteins in tumor tissues was measured by immunohistochemistry (IHC) and Western blotting. Tryptanthrin inhibited the proliferation, migration and invasion of MCF-7 cells, up-regulated the protein level of E-cadherin, and down-regulated those of MMP-2 and Snail, as suggested by the MCF-7 cell experiment. According to the results from in vivo experiment, tryptanthrin was effective in inhibiting tumor growth, and it showed favorable safety without inducing the fluctuations of body mass and organ coefficient (p > 0.05). In addition, tryptanthrin also suppressed the expression levels of NOS1, COX-2 and NF-κB in mouse tumor tissues, and regulated those of IL-2, IL-10 and TNF-α in the serum of tumor cells-transplanted mice. Tryptanthrin exerted its anti-breast cancer activities through modulating the inflammatory TME both in vitro and in vivo.

MRPL13 is a Prognostic Cancer Biomarker and Correlates with Immune Infiltrates in Breast Cancer.

ObjectiveTo study the expression of MRPL13 in breast cancer tissues using TCGA database, analyze the correlation between the expression and clinicopathological characteristics of patients, and explore the role of MRPL13 in the development of breast cancer (BC).MethodsThe BC mRNA data and clinical information were downloaded from TCGA database. The correlation between MRPL13 expression and clinicopathological parameters was analyzed. Cox regression multivariate analysis was used to explore the factors affecting the prognosis of BC patients. The UALCAN database was used to analyze the expression level of MRPL13 in BC and its relationship with clinical pathological factors. The GSEA method was used to predict the possible regulatory pathways of MRPL13. Immune responses of MRPL13 expression were analyzed using TISIDB and CIBERSORT. Additionally, GEPIA, K-M survival analysis and data from the HPA were used to validate the outcomes.ResultsThe expression of MRPL13 in BC tissues was significantly higher than normal counterparts, patients with low MRPL13 expression had a better survival prognosis, also indicated an independent prognostic factor. GSEA analysis showed that the regulation of cell migration, positive regulation of endothelial cell migration, and Notch signaling pathway were enriched in tissues with low expression of MRPL13. Additionally, depleting MRPL13 expression inhibited invasion in MCF-10A and MCF-7 cells. Furthermore, PCR showed that MRPL13 affected VEGFA and MMP gene expression. CIBERSORT analysis revealed that the amount of NK cells decreased when MRPL13 expression was high.ConclusionThe expression of MRPL13 mRNA is upregulated in BC tissues, and the expression level of MRPL13 is significantly related to the clinicopathological factors of patients. High MRPL13 expression is a poor prognostic factor for BC, and it can be used as a molecular marker for prognosis judgment and as a potential therapeutic target.

CACNA1B facilitates breast cancer cell growth and migration by regulating cyclin D1 and EMT: the implication of CACNA1B in breast cancer

Purpose This study mainly aimed to explore the influences of Calcium Voltage-Gated Channel Subunit Alpha1 B (CACNA1B) on the development of breast cancer and the related mechanism. Materials and methods The information of patients with breast cancer from TCGA database was used for analyses of CACNA1B expression and its prognostic value. Loss- and gain- of functions of CACNA1B were conducted in MCF7 and Bcap-37 cells, respectively. CCK-8, colony formation and transwell assays were applied for evaluating the cell viability and motility. Western blot was used for protein expression detection. Results We revealed that highly expressed CACNA1B in breast cancer tissues was related to poor prognosis according to the data gained from TCGA database. The outcomes of functional assays showed that depletion of CACNA1B restrained MCF7 cell growth, invasion and migration and high-expression of CACNA1B fortified the growth, invasion and migration in Bcap-37 cells. Finally, we manifested that silencing CACNA1B obviously raised the protein expression level of E-cadherin and reduced the protein levels of Cyclin D1, N-cadherin and Snail in MCF7 cells, whilst, over-expression of CACNA1B reduced the level of E-cadherin and increased the expression of Cyclin D1, N-cadherin and Snail in Bcap-37 cells. Conclusions These results identified CACNA1B as a forwarder of the growth, invasion and migration in breast cancer cells.

KDM3A regulates Slug expression to promote the invasion of MCF7 breast cancer cells in hypoxia.

Oxygen deprivation (hypoxia), which frequently occurs in the tumour microenvironment, is a strong driver of the phenotypic transition of cancer cells. An increase in metastatic potential such as cell invasion is a well-known phenotypical change induced in hypoxia. The present study demonstrated that lysine demethylase 3A (KDM3A), a Jumonji C domain-containing KDM, is involved in the hypoxia-induced invasion of MCF7 breast cancer cells. KDM3A depletion inhibits the induction of cell invasion without affecting MCF7 cell survival rate or proliferation under hypoxic conditions, whereas KDM3A overexpression enhances MCF7 cell invasion even under normoxic conditions. KDM3A suppresses E-cadherin expression, which is associated with epithelial-to-mesenchymal transition (EMT)-mediated cell invasion in hypoxia. In addition, KDM3A promotes the expression of Slug, an EMT transcription factor that negatively regulates E-cadherin expression. Consistent with this finding, the removal of the repressive transcription marker, dimethylated histone H3 at lysine 9 from the Slug promoter is dependent on hypoxia-induced recruitment of KDM3A. Collectively, the results of the present study suggest that KDM3A is a crucial transcriptional coactivator of Slug expression to induce MCF7 breast cancer cell invasion in hypoxia, and that inhibition of KDM3A may efficaciously prevent metastatic cancer development.

Clinical and biological impact of LINC02544 expression in breast cancer after neoadjuvant chemotherapy.

Analysis of breast cancer and cancer tissue after neoadjuvant chemotherapy (nCT) may be helpful to find new biomarkers. It is known that long non-coding RNAs (lncRNAs) are involved in the carcinogenic pathway and drug resistance of breast cancer. Our aim was to determine the role of LINC02544 in the behavior and outcome of post-nCT breast cancer. The expression level of LINC02544 in breast cancer and its effect on the survival time of patients were predicted by lnCAR database. In vitro, EdU, Wound-healing and transwell assays were used to detect the effects of LINC02544 on the proliferation, migration and invasion of MCF-7 cells, and the related regulatory networks were analyzed by the database. Quantitative Reverse Transcriptase-Polymerase Chain Reaction (QRT-PCR) was used to detect the expression of LINC02544 in 147 cases of nCT before and after treatment, and the relationship between the expression of LINC02544 and survival time and clinicopathological features was analyzed. LINC02544 was highly expressed in breast cancer and led to poor prognosis. Overexpression of LINC02544 promoted proliferation, invasion and migration of breast cancer cells. Compared with the residual tumor after nCT with low expression of LINC02544, the high expression of LINC02544 in the residual tumor after nCT was significantly correlated with overall survival and disease-free survival. In this study, it is suggested that LINC02544 has a potential application prospect as a biomarker and therapeutic target for breast cancer patients and neoadjuvant therapy patients.

ATP6AP2 is Overexpressed in Breast Cancer and Promotes Breast Cancer Progression.

BackgroundAdenosine triphosphatase H+ transporting accessory protein 2 (ATP6AP2), also known as (pro)renin receptor, is implicated in tumorigenesis and the progression of several types of cancer. This study investigated the role of ATP6AP2 in breast cancer.MethodsUALCAN and ONCOMINE datasets were utilized to compare transcript levels of ATP6AP2 in breast cancer and normal tissues. GOBO datasets were applied to examine ATP6AP2 expression in different breast cancer cell lines. We used the cBioPortal website to explore the gene alterations and copy number alterations of ATP6AP2 in breast cancer. Cell Counting Kit-8 and transwell assays were conducted to evaluate ATP6AP2 function in MCF-7 breast cancer cells. Finally, we used the cBioPortal website to establish the interaction network of ATP6AP2 in breast cancer and performed functional enrichment analysis based on Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways.ResultsATP6AP2 was overexpressed in breast cancer tissues and breast cancer cell lines in the UALCAN, ONCOMINE, and GOBO datasets. The major type of ATP6AP2 alteration was mRNA upregulation. Moreover, ATP6AP2 was most highly expressed in luminal type breast cancer. Finally, ATP6AP2 knockdown reduced MCF-7 cell proliferation, invasion and migration. Functional enrichment analysis suggested that ATP6AP2 regulates several cancer-related pathways, especially the Wnt/β-catenin signaling pathway.ConclusionApplying multi-dimensional analytical methods, we demonstrate that ATP6AP2 is upregulated in breast cancer and may promote its development and progression.

Effect of MicroRNA-766 Promotes Proliferation, Chemoresistance, Migration, and Invasion of Breast Cancer Cells

IntroductionBreast cancer (BCa) remains the most common cancer in women worldwide. It has been shown that microRNAs (miRs) play essential roles in tumorigenesis and progression in many types of cancers, including BCa. We assessed the role of miR-766 on the proliferation, chemosensitivity, migration, and invasion of BCa cells. Materials and MethodsThe effect of miR-766 on the proliferation of MCF-7 and T47D BCa cells was evaluated using the MTT assay. The function of miR-766 on the migration and invasion of MCF-7 and T47D cells was examined using Transwell migration and Matrigel invasion assays. Protein expression was evaluated by Western blot. The role of miR-766 on 5-fluorouracil–induced apoptosis in MCF-7 and T47D cells was determined using the Caspase-Glo3/7 assay. A subcutaneous tumor xenograft was performed to examine the effect of miR-766 on tumor growth in vivo. ResultsUpregulation of miR-766 improved the proliferation, invasion, and migration of BCa cells. Furthermore, miR-766 reduced the sensitivity of MCF-7 and T47D cells to 5-fluorouracil treatment. The tumor xenograft experiment showed that miR-766 promoted BCa growth in vivo. miR-766 decreased 5-flurouracil–induced apoptosis by regulation of BAX and Bcl-2 expression. miR-766 also affected the epithelial–mesenchymal transition by altering E-cadherin, N-cadherin, SNAIL, and vimentin expression in MCF-7 and T47D cells. Further study showed that the expression of phosphatase and tensin homolog and phosphorylated AKT in MCF-7 and T47D cells had changed after aberrant expression of miR-766.Conclusion: miR-766 displayed important roles in tumorigenesis and progression in BCa cells and might act as a potential biomarker to predict the chemotherapy response and progression in BCa.

Silencing DSCAM-AS1 suppresses the growth and invasion of ER-positive breast cancer cells by downregulating both DCTPP1 and QPRT.

Breast cancer (BC) remains a significant threat to the health of women; however, the mechanism underlying the initiation and progression of BC is poorly understood. We analyzed data from the Gene Expression Omnibus database and The Cancer Genome Atlas datasets to identify differentially expressed genes between BC and normal tissues. The roles of dCTP pyrophosphatase 1 (DCTPP1) and quinolinate phosphoribosyltransferase (QPRT) in BC cells were investigated after knocking down or overexpressing the genes. The regulatory effects of Down syndrome cell adhesion molecule antisense RNA 1 (DSCAM-AS1) on DCTPP1 and QPRT expression were determined using luciferase reporter, RNA immunoprecipitation, RNA pull-down, chromatin immunoprecipitation, and fluorescence in situ hybridization assays. DCTPP1 and QPRT were overexpressed in BC compared to normal tissues. Overexpression of DCTPP1 and QPRT was associated with poor BC progression and promoted growth, migration, and invasion of MCF7 and T47D cells but inhibited apoptosis. DSCAM-AS1 increased QPRT expression via competitively binding miRNA-150-5p and miRNA-2467-3p. DSCAM-AS1 promoted DCTPP1 gene transcription by affecting H3K27 acetylation and enhanced DCTPP1 mRNA stability by binding to the 3′ untranslated region, which collectively resulted in DCTPP1 overexpression. Overall, DSCAM-AS1 knockdown decreased both DCTPP1 and QPRT expression, inhibiting the growth, migration, and invasion of estrogen receptor-positive BC.

The Activation of Extracellular Signal-Regulated Kinase (ERK)/Mitogen-Activated Protein Kinase (MAPK) Signal Transduction Pathway on Invasive Growth of Breast Cancer

ERK/MAPK signal transduction pathway participates in occurrence and progression of breast cancer. This study utilized epidermal growth factor (EGF) and ERK antagonist PD98059 to analyze ERK/MAPK signal's role in breast cancer cells. Breast cancer MCF-7 cell line was separated into control group, EGF group, PD98059 group and EGF+ PD98059 group. Cell proliferation activity was assessed by MTT, whilst TUNEL was to describe cell apoptosis. Transwell assay was employed for cell invasion and migration. Protein expression of ERK1/2 and p-ERK1/2. Compared to control group, EGF treatment elevated cell proliferation or invasion/migration and decreased apoptosis at 6 h, 12 h and 24 h. PD98059 treatment decreased proliferation activity or cell invasion/migration, and enhanced apoptosis. Treatment of EGF plus PD98059 further decreased proliferation and invasion/migration compared to EGF group, but with higher level than PD98059 group (p < 0 05). EGF treatment elevated ERK1/2 and pERK1/2, PD98059 group had lower ERK1/2 or pERK1/2 expression, whilst EGF plus PD98059 treatment further decreased ERK1/2 and pERK1/2 expression (p < 0 05). EGF can regulate proliferation and invasion of breast cancer MCF-7 cells via ERK/MAPK signaling.

Silence of TPPP3 suppresses cell proliferation, invasion and migration via inactivating NF-κB/COX2 signal pathway in breast cancer cell.

Malignant phenotypes are leading causes of death in patients with breast cancer (BC). Previously, it has been proved that tubulin polymerization promoting protein 3 (TPPP3) participates in cell progressions in several human cancers. Little is known about the functions of TPPP3 in BC. Herein, we detected the expression of TPPP3 in 54 clinical BC tissues and two BC cell lines by immunohistochemistry and Western blot. CCK-8, wound healing, colony formation and Transwell assays were used to assess cell proliferation, clone formation, invasion and migration of MCF-7 and T47D cells after transfection with TPPP3 siRNA. Meanwhile, related-proteins expression was detected using Western blot. TPPP3 was found to be highly expressed in the tissues from the patients with BC. Poor outcomes were associated with the high expression of TPPP3 in all patients with BC. When MCF-7 and T47D cells receiving TPPP3 siRNA transfection, the capacities of proliferation, clone formation, invasion and migration were suppressed and the expression of MMP-2/-9 and NF-κB p65/COX2 was notably reduced. The dual-luciferase reporter assay indicated that the promoter regions of NF-κB p65 could combine to TPPP3. Overall, the present study demonstrated that TPPP3 played a significant role in BC, and its inhibition lead to the suppression of NF-κB/COX-2 signalling pathway along with the reduction of malignant phenotypes. SIGNIFICANCE OF THIS STUDY: Previously, it has been proved that tubulin polymerization promoting protein 3 (TPPP3) participates in cell progression in several human cancers. Little is known about the function of TPPP3 in BC. Our study was the first direct evidence to support the role of TPPP3 in tumorigenesis and metastasis of BC. Although the underlying mechanism has not been fully delineated, these findings suggested that TPPP3 was an important factor in the tumour progression and metastasis of BC cells and provided a molecular basis for potential therapeutic implications in the treatment of patients with BC.

TCDD-induced antagonism of MEHP-mediated migration and invasion partly involves aryl hydrocarbon receptor in MCF7 breast cancer cells

Evidence has shown that the activation of AhR (aryl hydrocarbon receptor) can promote cancer cell metastasis. However, limited studies have been carried out on mixed exposure to endocrine-disrupting chemicals (EDCs), especially in human breast cancer. Therefore, using MCF7 human breast cancer cells, we investigated the effects of coexposure to MEHP (mono 2-ethylhexyl phthalate) and TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) on cell migration and invasion, as well as the roles of AhR and the MMP/slug pathway. Our data suggest that MEHP or TCDD can induce migration and invasion in MCF7 cells, and the promotion is partly AhR dependent. We also observed that MEHP antagonized TCDD to reduce AhR-mediated CYP1A1 expression. Subsequently, we revealed that MEHP recruited AhR to dioxin response element (DRE) sequences and decreased TCDD-induced AhR-DRE binding in CYP1A1 genes. Overall, MEHP is a potential AHR agonist, capable of decreasing TCDD-induced AhR-DRE binding in CYP1A1 genes. The antagonizing effect of coexposure led to the inhibition of the epithelial–mesenchymal transition (EMT) in MCF7 cells. Our study provides new evidence for the potential mechanisms involved in EDCs exposure and their interactions in EMT.

TRPC1 inhibits the proliferation and migration of estrogen receptor-positive Breast cancer and gives a better prognosis by inhibiting the PI3K/AKT pathway.

Previous studies have indicated that transient receptor potential (TRP) channels can influence cancer development. The TRPC subfamily consists of seven subtypes, TRPC1 - TRPC7. Interestingly, the expression levels of TRPC1 have been shown to be totally different in different breast cancer cell lines. Nevertheless, the underlying mechanism remains unknown. In this study, we explore the significance of TRPC1 expression in breast cancer. Immunohistochemical TRPC1 staining was performed in 278 samples. TRPC1 expression in different breast tissues were examined. Then, the influence of TRPC1 on migration, invasion and proliferation was explored. We analyzed the protein of TRPC1 by Western blot to prove which pathway may be involved in. Finally, we use online database to predict the prognosis of TRPC1 in breast cancer. Through immunohistochemistry and in vitro experiments, we found that the expression level of TRPC1 was higher in breast cancer cells as compared with that in normal breast epithelial cells. Moreover, the expression level of TRPC1 was different between estrogen receptor-positive (ER +) and -negative (ER -) breast cancer. It was shown that TRPC1 inhibited MCF7 cell proliferation, migration, and invasion in vitro. Western blotting revealed that TRPC1 inhibited the PI3K/AKT pathway and epithelium-mesenchymal transformation, leading to subsequent inhibition of cell proliferation and metastasis. In luminal A and luminal B patients, those with high TRPC1 expression had a better prognosis. On the contrary, in basal-like and triple-negative breast cancer (TNBC) subtypes, patients with high-TRPC1 expression had a worse prognosis. We confirmed that TRPC1 was high expression in breast cancer. Overexpression of TRPC1 inhibits proliferation and migration of ER + breast cancer and gives a better prognosis by inhibiting PI3K/AKT pathway activation. TRPC1 may be an independent prognostic predictor in breast cancer patients.