Down-regulation of METTL5 inhibits proliferation, migration and invasion of triple-negative breast cancer cells through Wnt/6-catenin signaling pathway / 中国药理学通报

Aim To investigate the role and potential mechanism of methyltransferase-like 5 (METTL5) in triple-negative breast cancer (TNBC) . Methods The expression of METTL5 in TNBC tumor tissues and cell lines was detected by immunohistochemistry and Western blot. After shRNA targeting METTL5 (shRNAMETTL5) was transfected into TNBC cells, cell proliferation, migration and invasion were detected by CCK-8, colony formation, wound healing and Transwell assays, respectively. Western blot was used to detect the expression of Wnt/p-catenin signaling-related key proteins. A xenograft tumor model was constructed to verify the effect of METTL5 knockdown on the growth of TNBC cells and Wnt/p-catenin signaling activity in vivo. Results The expression of METTL5 was up-regulated in TNBC tumor tissues and cell lines (P < 0. 01) . Knockdown of METTL5 significantly inhibited the proliferation, migration and invasion of TNBC cells and reduced the expression of Wnt/p-catenin signaling molecules (3-catenin, cyclin Dl, matrix metalloproteinase (MMP) -2 and MMP-7 (all P < 0. 01) . Knockdown of METTL5 reduced tumor growth and Wnt/pcatenin signaling activity in vivo. Conclusions Knockdown of METTL5 can inhibit the proliferation, migration and invasion of TNBC cells, which may be related to the inhibition of Wnt/p-catenin signaling pathway.

A molecular approach to triple-negative breast cancer: targeting the Notch signaling pathway

ABSTRACT Introduction Triple-negative breast cancer is an aggressive subtype of breast cancer characterized by the absence of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression. This phenotype renders triple-negative breast cancer cells refractory to conventional therapies, resulting in poor clinical outcomes and an urgent need for novel therapeutic approaches. Recent studies have implicated dysregulation of the Notch receptor signaling pathway in the development and progression of triple-negative breast cancer. Objective This study aimed to conduct a comprehensive literature review to identify potential therapeutic targets of the Notch pathway. Our analysis focused on the upstream and downstream components of this pathway to identify potential therapeutic targets. Results Modulating the Notch signaling pathway may represent a promising therapeutic strategy to treat triple-negative breast cancer. Several potential therapeutic targets within this pathway are in the early stages of development, including upstream (such as Notch ligands) and downstream (including specific molecules involved in triple-negative breast cancer growth). These targets represent potential avenues for therapeutic intervention in triple-negative breast cancer. Comments Additional research specifically addressing issues related to toxicity and improving drug delivery methods is critical for the successful translation of these potential therapeutic targets into effective treatments for patients with triple-negative breast cancer.

Programmed cell death protein 1 is a marker for neoadjuvant chemotherapy response in triple-negative breast cancer

SUMMARY OBJECTIVE: Tumor-infiltrating lymphocytes are detectable in up to 75% of triple-negative breast cancer. The composition of these infiltrates may influence prognosis and is not known regarding regulatory or effector lymphocytes. The objectives of this study were to describe and quantify the composition of the tumor-infiltrating lymphocytes before and after chemotherapy (neoadjuvant chemotherapy) and to evaluate their association with complete pathological response and overall survival. METHODS: This was a retrospective observational study. Clinical and pathological data from 38 triple-negative breast cancer patients treated with neoadjuvant chemotherapy at the University Hospital (HUCFF/UFRJ), between November 2004 and November 2018, were analyzed. The Stromal tumor-infiltrating lymphocytes (Stromal tumor-infiltrating lymphocytes) have been identified on hematoxylin and eosin-stained sections according to the guidelines of the "International tumor-infiltrating lymphocytes Working Group." Immunohistochemistry studies were performed to identify T-cell subsets (i.e., CD3, CD4, CD8, and FOXP3) and T-cell exhaustion (i.e., programmed cell death protein 1). RESULTS: Statistically significant changes in stromal tumor-infiltrating lymphocyte categories were observed before and post-neoadjuvant chemotherapy, with 32% of intermediate cases becoming high. The correlation between pre-neoadjuvant chemotherapy stromal tumor-infiltrating lymphocytes and pathological response, pre-neoadjuvant chemotherapy and post-neoadjuvant chemotherapy, and stromal tumor-infiltrating lymphocytes and overall survival was not statistically significant. However, we noticed an increase of cells that favor the antitumor activity (i.e., CD3, CD8, and CD8/FOXP3 ratio) and decreased levels of cells inhibiting tumor activities (i.e., FOXP3 and programmed cell death protein 1) post-neoadjuvant chemotherapy. Importantly, programmed cell death protein 1 expression pre-neoadjuvant chemotherapy showed an association with pathological response. CONCLUSION: In this study, we observed that chemotherapy significantly increases stromal tumor-infiltrating lymphocytes, CD8 T cells, as well as CD8/FoxP3 ratio. Most importantly, programmed cell death protein 1 expression before neoadjuvant chemotherapy positively correlates with pathological response suggesting the use of programmed cell death protein 1 as a prognostic marker before neoadjuvant chemotherapy.

CLINICOPATHOLOGICAL STUDY IN TRIPLE NEGATIVE BREAST CANCER

Background and Objectives: - Carcinoma Breast is most common malignancy in females in USA and second among cases deaths in females (after lung cancer). There is considerable geographic , ethnic and racial variability in Breast cancer in evidence with about 5 fold variation throughout the world. Triple negative breast cancer is a heterogonous disease diagnosed by Immune Histo Chemistry (IHC).Triple Negative Breast cancer is characterized by tumor that do not express ER or PR and HER2neu . Proto typical Triple Negative Brest cancer is aggressive in nature and associate with poor prognosis. The Objectives of this study is to analyse the clinical and Pathological features of Triple Negative Breast Cancer and compare the result with similar studies in literature. Fifty Methods:- cases Triple negative Breast Cancer were included in this study. Clinical and pathological features and treatment were noted. Incidence Result:- of Triple Negative Breast Cancer was 35%. The median age of presentation was 45yrs. There were 4% males Triple negative Breast cancer cases out of female patients, most of patients were Pre (or) Perimenopausal(65%). 4% patients had family history of malignantly. Most common stage of presentation was stage III (46%). In Stage IV, Lung and bone metastasis was common. Ten Patients received Neoadjuvant chemo therapy (NACJ) and disease progressed in 4% while on Neoadjuvant chemotherapy, Even though 45 patients had surgery only 34 were eligible to received Adjuvant Radiotherapy. Total of 18% Patients had either progressive disease while on treatment (8%) (or) recurrence 10%. Eighteen percent patients died due to the disease. 33% patients on follow up. There were more Invasive Duct Cell carcinoma (IDCC) cases with medullary differentiations (or) Purse medullary Carcinomas (12%). No deaths Occur in the medullary variants TNBC. Majority of the tumor were high grade margins were negative in most of the cases. Incidence of Tri Inclusion:- ple negative breast cases was higher than western literature but comparable to Indian Studies. The age of Presentation was about 10 years younger than western data. Triple Negative Breast cancer was more common in young, pre (or) perimenopausal women. Small number of patients had family history, majority were state II (or) III. There was high number of progressive disease, recurrence and death while on the study (or) within less than 1 yr of treatment. Triple Negative Breast cancer is very aggressive disease with relatively better prognosis in the medullary variant Triple Negative Breast Cancer.

Carcinoma de mama triple negativo. Estudio anatomo-estadístico / Triple- negative breast cancer. An anatomical and statistical study

Introducción: El carcinoma de mama triple negativo se asocia a un comportamiento biológico más agresivo y de desfavorable pronóstico. Objetivo: Determinar la incidencia del subtipo molecular triple negativo en carcinomas mamarios y su relación con otras variables clínico-patológicas de valor pronóstico. Método: Se realizó un estudio descriptivo y retrospectivo, en el Hospital Universitario Docente «Celestino Hernández Robau» de Villa Clara, en el período comprendido de enero de 2017 a junio de 2019, con el fin de determinar la incidencia de los tumores triples negativos y su relación con las variables edad, talla tumoral, tipo y grado histológicos e índice de proliferación. Resultados: Se determinó la incidencia del subtipo molecular triple negativo en carcinomas mamarios y su relación con las formas histológicas moderada y poco diferenciadas. Conclusiones: El subtipo molecular triple negativo en carcinomas mamarios está asociado con frecuencia a: la edad posmenopáusica, el tipo histológico ductal, el grado histológico alto, altos índices de Ki-67 y talla tumoral mayor de 2 cm.

Introduction: triple-negative breast cancer has a more aggressive biological behaviour and is associated with an unfavourable prognosis. Objective: to determine the incidence of triple- negative breast cancer molecular subtypes and its relationship with other clinical and pathological variables of prognostic value. Methods: a descriptive and retrospective study was carried out at "Celestino Hernández Robau" University Teaching Hospital from Villa Clara between January 2017 and June 2019 in order to determine the incidence of triple- negative tumors and its relationship with the variables: age, tumor size, histological type and grade as well as proliferative index. Results: the incidence of triple- negative breast cancer molecular subtype and its relationship with moderate and poorly differentiated histological forms were determined. Conclusions: triple- negative breast cancer molecular subtype is frequently associated with postmenopausal age, ductal histological type, high histological grade, high Ki-67 indices and tumor size greater than 2 cm.

BRCA1 promoter methylation & its immunohistochemical correlation in sporadic breast cancer

Background & objectives: Studies have shown that apart from hereditary breast carcinomas, breast cancer susceptibility gene 1 (BRCA1) mutations conferring to its loss are seen in sporadic breast carcinomas (SBC) as well. The aim of the present study was to assess BRCA1 methylation in females presenting at King George’s Medical University, Lucknow, with SBC by both immunohistochemistry (IHC) and methylation PCR with respect to hormonal profile and various morphological prognostic parameters. The primary objective was to look for the association between BRCA1 protein expression and DNA promoter methylation. Methods: 81 mastectomy specimens from SBC of invasive breast carcinoma (no special type) were included in this study. After a detailed morphological assessment, formalin fixed paraffin embedded tissue from a representative tumour area was selected for BRCA1 IHC by heat-mediated antigen retrieval under high pH and DNA extraction and further bisulphate treatment. BRCA1 was studied for methylation by methylated and unmethylated PCR-specific primers. Results: BRCA1 promoter methylation was present in 42/81 (51.9%) participants, with significant BRCA1 protein loss (72.7%; P=0.002). A significant association between BRCA1 loss and hormonal profile was found (P=0.001); maximum in triple negative breast carcinoma (TNBC) (72%; 18/25). Most of the TNBC also harboured methylation (68%). Although not significant grade II and III tumours, lymph vascular invasion, ductal carcinoma in situ, and nodal metastasis (?3) were seen in a higher percentage in methylated tumours. Mortality in SBC was significantly associated with BRCA1 loss (30.3%; P=0.024). Interpretation & conclusions: Study results highlight the concept of “BRCAness” in SBC as well. Hence, we can confer that identification of BRCA1 loss in SBC can make it a perfect candidate for poly ADP- ribose polymerase inhibitors or cisplatin-based therapy like hereditary ones.

Expression of long non-coding RNA FRAPT in triple-negative breast cancer and its biological significance / 中国生物制品学杂志

@#Objective To investigate the expression of long non-coding RNA FRAPT(lncRNA FRAPT) in triple-negative breast cancer(TNBC) cells and analyze its effects on proliferation,cell cycle and drug resistance of TNBC cells.Methods Using scRNASeqDB and TCGA on-line bioinformatics database,the expression of lncRNA FRAPT in TNBC and its correlation with prognosis were detected;TNBC cell line MDA-MB-231 was transfected with si-lncRNA FRAPT and si-Ctrl(negative control) by using Lipofectamine~(TM) 2000 respectively,of which the proliferation and cell cycle changes after transfection were detected by SRB test and flow cytometry,and the drug resistance to chemotherapy drug paclitaxel(PTX)was detected.Results The expression of lncRNA FRAPT was up-regulated in TNBC tissues and cells,and its high expression was positively correlated with the poor prognosis of TNBC patients(Hazard Ratio=1.66,P=0.047).Silencing lncRNA FRAPT significantly inhibited the proliferation of TNBC cells,with the cell cycle arrested in G1 phase,while increased the sensitivity of TNBC cells to PTX.Conclusion LncRNA FRAPT was highly expressed in TNBC and related to tumor prognosis-Silencing lncRNA FRAPT inhibited proliferation and cell cycle of TNBC,and increased the sensitivity to chemotherapy drug PTX.

Effect of transcription factor NFIB on cell proliferation and invasion in breast cancer / 中国医师杂志

Objective:To investigate the effect of transcription factor nuclear factor IB (NFIB) on cell proliferation and invasion in breast cancer.Methods:The lentivirus pLKO.1-shNFIB plasmid was constructed, packaged and infected with human estrogen receptor positive (ER + ) breast cancer cell line MCF-7 and triple-negative breast cancer (TNBC) cell line MDA-MB-231, respectively, NFIB was stably knocked down and verified by Western blot method; Cell count test (CCK-8) and clone formation test were used to investigate the effect of knockdown NFIB on the growth and proliferation of breast cancer cells; The transwell experiment and Western blot method were performed to detect the expression of epithelial mesenchymal transition protein markers. The effect of knockdown NFIB on the invasive ability of triple-negative breast cancer cells was explored; Kaplan-Meier survival was used to analyze web data (http: //kmplot.com/analysis/) to explore the effect of NFIB on the prognosis of ER + breast cancer and triple-negative breast cancer patients. Results:In MCF-7 and MDA-MB-231 breast cancer cells, knocking down NFIB inhibited cell growth and proliferation; In triple-negative breast cancer MDA-MB-231 cells, knocking down NFIB promoted the expression of interstitial marker fibronectin and promoted cell invasion; The lower the expression of NFIB, the worse the prognosis of triple negative breast cancer patients, while the expression of NFIB had no effect on the prognosis of ER + breast cancer patients. Conclusions:Knocking down NFIB inhibits the proliferation of MCF-7 cells, and the expression level of NFIB is not related to the prognosis of ER + breast cancer patients; Knocking down NFIB inhibits the proliferation of MDA-MB-231 cells but promotes their invasion; The low expression of NFIB is associated with the poor prognosis of triple-negative breast cancer patients.

Research progress of p53 protein in the development mechanism of triple negative breast cancer / 中国医师杂志

Tumor suppressor gene p53 plays an important role in regulating cell cycle, controlling apoptosis and repairing damaged DNA. Mutation of this gene is closely related to the occurrence, development and drug resistance of various tumors. The mutant p53 protein is closely related to the growth and metastasis of triple negative breast cancer (TNBC) with higher malignancy and higher risk of metastasis. This paper expounds the mechanism of p53 protein participating in the occurrence, development and metastasis of TNBC, introduces the effect of interfering with mouse dual-microbody gene 2 (MDM2), activated T cell nuclear factor 1 (NFAT1) and other proteins on p53, as well as small molecular targeted drugs closely related to p53 protein, and provides a new direction and theoretical basis for targeted treatment of TNBC.

Long non-coding RNA00461 regulates apoptosis in triple-negative breast cancer cells by combining with the proto-oncogene c-Myc / 中华内分泌外科杂志

Objective:To investigate the effect of long non-coding RNA00461 (LINC00461) on apoptosis of triple negative breast cancer cells.Methods:RT-qPCR was used to detect the expression of LINC00461 in normal breast epithelial cells MCF-10A, TNBC cell lines MDA-MB-231 and MDA-MB-468. The apoptosis rate was detected by Annexin V-FITC/PI double staining cell apoptosis kit. Western blot was used to detect apoptosis-associated protein. The localization of LINC00461 in cells was detected by FISH. RNA pulldown and RIP were used to detect the interaction between LINC00461 and c-Myc. The effect of LINC00461 on TNBC apoptosis was verified by subcutaneous tumorigenesis in nude mice.Results:Compared with MCF-10A, LINC00461 expression in MDA-MB-231 and MDA-MB-468 cells was significantly increased. Interference with LINC00461 significantly reduced the expression of LINC00461 and c-Myc protein. Overexpression of LINC00461 significantly decreased the expression level of apoptosis-related protein. Overexpression of LINC00461 significantly reduced the apoptosis rate by 50%-70%, with a statistically significant difference. FISH results showed that LINC00461 was mainly localized in the cytoplasm. RNA pulldown results showed that LINC00461 interacted with c-Myc. RIP results showed that the concentration of LINC00461 in c-Myc group was more than 400%, and the difference was statistically significant. In addition, overexpression of c-Myc reduced the promotion effect of knockdown LINC00461 on the apoptosis rate of 30%-50%. In animal experiments, overexpression of LINC00461 significantly increased tumor volume (50%-80%) and tumor weight (30%-50%) .Conclusion:LINC00461, mainly located in the cytoplasm, regulates the apoptosis of TNBC cells, and its molecular mechanism may be that LINC00461 interacts with c-Myc protein to play an important role in regulating the apoptosis of TNBC cells.

Relationships between PIK3CA gene status and clinical features and prognosis in triple-negative breast cancer / 国际肿瘤学杂志

Objective:To detect the status of PIK3CA in triple-negative breast cancer (TNBC) , and to analyze the relationships between PIK3CA mutation and clinical features and its impact on prognosis.Methods:From January 1, 2016 to December 31, 2018, 50 patients with primary TNBC admitted to Xinxiang Central Hospital of Henan Province were collected. The PIK3CA mutation status was detected, and the relationships between PIK3CA mutation and clinical characteristics of patients with TNBC and its impact on prognosis were analyzed.Results:PIK3CA gene mutation was detected in 9 of 50 TNBC patients, with a mutation frequency of 18.0%. H1047R mutation was found in 4 cases, E545K mutation in 3 cases and E542K mutation in 2 cases. PIK3CA gene mutation was not associated with age ( χ2=3.55, P=0.060) , tumor location ( χ2=1.01, P=0.315) , tumor size ( χ2<0.01, P>0.999) , lymph node status ( χ2=0.76, P=0.385) , clinical stage ( χ2=0.65, P=0.420) , Ki-67 value ( χ2<0.01, P>0.999) , P53 status ( χ2=0.02, P=0.894) and human epidermal growth factor receptor-2 (HER-2) status ( χ2=1.65, P=0.200) . Prognostic analysis showed that 3-year disease-free survival rates of wild-type PIK3CA patients was significantly higher than that of mutant PIK3CA patients (80.5% vs. 11.1%, χ2=28.23, P<0.001) . Conclusion:The frequency of PIK3CA gene mutation is higher in TNBC patients. There is no correlation between PIK3CA mutation and clinicopathologic features in TNBC patients. PIK3CA gene mutation may be significantly associated with poor prognosis of TNBC patients.

Risk Factors and Predictive Model for Severe Myelosuppression due to Chemotherapy in Triple-negative Breast Cancer / 中山大学学报(医学科学版)

ObjectiveTo investigate the risk factors and construct a predictive model for severe myelosuppression due to chemotherapy in triple negative breast cancer （TNBC）. MethodsPatients with TNBC who received anthracycline combined with cyclophosphamide sequential paclitaxel chemotherapy regimen at the Second Affiliated Hospital of Nanchang University from September 2， 2016 to September 2， 2021 were selected and assigned to severe myelosuppression group and no/mild myelosuppression group. The χ2 test and binary logistic regression were used to analyze the risk factors for severe myelosuppression due to chemotherapy and to develop a prediction model. Hosmer-Lemeshow test and receiver operating characteristic （ROC） curve were used to evaluate the predictive efficiency of the regression model. Kappa consistency test was used to verify the regression model externally. ResultsA total of 207 patients who met the inclusion were enrolled and 106 patients （51%） had severe myelosuppression. Binary logistic regression multivariate analysis showed that age 40 to 60 years （OR = 3.463， 95% CI： 1.144 to 10.486， P = 0.028）， age >60 years （OR = 3.474， 95% CI： 1.004 to 12.020， P = 0.049）， body mass index （BMI） 18.5 to 24.0 （OR = 1.445， 95% CI： 0.686 to 3.087， P = 0.328）， BMI <18.5 （OR = 3.582， 95% CI： 1.260 to 10.182， P = 0.017）， tumor TNM stage Ⅱ （OR = 1.698， 95% CI： 0.831 to 3.468， P = 0.146）， tumor TNM stage Ⅲ （OR = 2.943， 95% CI： 1.199 to 7.227， P = 0.019）， previous diabetes （OR = 2.441， 95% CI： 1.076 to 5.539， P = 0.033）， low pre-treatment albumin level （OR = 2.759， 95% CI： 1.141 to 6.669， P = 0.024） and low pre-treatment lymphocytes （OR = 3.428， 95% CI： 1.689 to 6.958， P = 0.001） were independent risk factors for severe myelosuppression due to chemotherapy. The χ2 value for the logistic regression model Hosmer-Lemeshow test was 11.507， P= 0.175， the area under the ROC curve was 0.763， standard error 0.033， 95% CI： 0.698-0.828， P=0.000. External validation showed that the prediction model had a specificity of 88% and a sensitivity of 80%； the kappa value was 0.679， standard error 0.081， P=0.000. conclusionThis logistic regression model had high predictive efficacy and is useful for clinicians to predict whether patients with TNBC develop severe myelosuppression.

Effect of Chaihu Guizhitang on Triple-negative Breast Cancer Cells： Based on HIF-1α/VEGFA Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Chaihu Guizhitang on triple-negative breast cancer （TNBC） cells based on hypoxia-inducible factor-1α （HIF-1α）/vascular endothelial growth factor A （VEGFA） signaling pathway. MethodTNBC xenograft model was established and the cells were randomized into model group， capecitabine group （0.2 mg·kg-1）， Chaihu Guizhitang low-dose group， medium-dose group， and high-dose group （10.62， 21.23， 42.46 g·kg-1）， with 10 mice in each group. After 21 days of medication， the content of tumor necrosis factor-α （TNF-α） in serum was detected by enzyme-linked immunosorbent assay （ELISA）. The expression of HIF-1α mRNA was detected by real-time fluorogenic quantitative polymerase chain reaction （real-time PCR）. Immunohistochemistry （IHC） was employed to detect the expression of HIF-1α， TNF-α， and VEGFA in tumor tissues， and CD34 staining to examine the angiogenesis in tumor tissues. Microvessel density （MVD） was calculated， and the protein expression of HIF-1α， VEGFA， and epidermal growth factor receptor （EGFR） in tumor tissues was measured by Western blot. ResultCompared with the model group， the rest four groups showed low levels of TNF-α （P<0.01）， HIF-1α mRNA （P<0.01）， expression of HIF-1α， TNF-α， VEGFA， and CD34 in cells， and MVD （P<0.05， P<0.01）， and low protein levels of HIF-1α， VEGFA， and EGFR （P<0.01）. Compared with capecitabine group， medium-dose and high-dose Chaihu Guizhitang decreased the level of TNF-α （P<0.01）， HIF-1α mRNA （P<0.01）， expression of HIF-1α， TNF-α， and VEGFA in cells （P<0.01）， CD34 expression， MVD， and protein levels of HIF-1α， VEGFA， and EGFR （P<0.01）. ConclusionChaihu Guizhitang may inhibit the angiogenesis in TNBC cells by regulating the expression of HIF-1α/VEGFA signaling pathway， thus exerting anti-tumor effect.

Silencing RAB27a inhibits proliferation, invasion and adhesion of triple-negative breast cancer cells / 南方医科大学学报

OBJECTIVE@#To investigate the effect of inhibition of RAB27 protein family, which plays a pivotal role in exosome secretion, on biological behaviors of triple-negative breast cancer cells.@*METHODS@#Quantitative real-time PCR and Western blotting were used to examine the expressions of RAB27 family and exosome secretion in 3 triple-negative breast cancer cell lines (MDA-MB-231, MDA-MB-468, and Hs578T) and a normal breast epithelial cell line (MCF10A). The effect of small interfering RNA (siRNA)-mediated silencing of RAB27a and RAB27b on exosome secretion in the 3 breast cancer cell lines was detected using Western blotting, and the changes in cell proliferation, invasion and adhesion were evaluated.@*RESULTS@#Compared with normal breast epithelial cells, the 3 triple-negative breast cancer cell lines exhibited more active exosome secretion (P < 0.001) and showed significantly higher expressions of RAB27a and RAB27b at both the mRNA and protein levels (P < 0.01). Silencing of RAB27a in the breast cancer cells significantly down-regulated exosome secretion (P < 0.001), while silencing of RAB27b did not significantly affect exosome secretion. The 3 breast cancer cell lines with RAB27a silencing-induced down-regulation of exosome secretion showed obvious inhibition of proliferation, invasion and adhesion (P < 0.01) as compared with the cell lines with RAB27b silencing.@*CONCLUSION@#RAB27a plays central role in the exosome secretion in triple-negative breast cancer cells, and inhibiting RAB27a can inhibit the proliferation, invasion and adhesion of the cells.

Inhibition of CD36 and Nogo-B expression inhibited the proliferation and migration of triple negative breast cancer cells / 生物工程学报

Cluster of differentiation 36 (CD36) is a membrane glycoprotein receptor capable of binding and transporting fatty acid. Nogo-B regulates the metabolism of fatty acids in the liver and affects the development of liver cancer. To date, it remains unclear whether the interaction between CD36 and Nogo-B affects the proliferation and migration of breast cancer cells. In the current study, we aimed to determine whether the interference of CD36 and Nogo-B affects the proliferation and migration of triple-negative breast cancer (TNBC) cells. The results showed that inhibition of CD36 or Nogo-B alone can inhibit the proliferation and migration of TNBC cells, and the inhibitory effect was more pronounced when CD36 and Nogo-B were inhibited simultaneously. Meanwhile, it was found that inhibition of CD36 and Nogo-B expression can inhibit the expression of Vimentin, B-cell lympoma-2 (BCL2) and proliferating cell nuclear antigen (PCNA). In vivo, knockdown of CD36 or Nogo-B in E0771 cells reduced its tumorigenic ability, which was further enhanced by knockdown of CD36 and Nogo-B simultaneously. Mechanistically, inhibition of CD36 and Nogo-B expression can decrease fatty acid binding protein 4 (FABP4) and fatty acid transport protein 4 (FATP4) expression. Moreover, overexpression of CD36 and Nogo-B-induced cell proliferation was attenuated by FABP4 siRNA, indicating that inhibition of CD36 and Nogo-B expression could inhibit the absorption and transport of fatty acids, thereby inhibiting the proliferation and migration of TNBC. Furthermore, inhibition of CD36 and Nogo-B expression activated the P53-P21-Rb signaling pathway which contributed to the CD36 and Nogo-B-inhibited proliferation and migration of TNBC. Taken together, the results suggest that inhibition of CD36 and Nogo-B can reduce the proliferation and migration of TNBC, which provides new targets for the development of drugs against TNBC.

Effect of ACE2 on the prognosis of breast cancer and its potential mechanism / 中国药科大学学报

@#This study aims to investigate the effect of transmembrane protein angiotensin converting enzyme 2 (ACE2) on the prognosis of breast cancer and its potential mechanism.Public databases were used to analyze ACE2 expression and its relationship with clinicopathological features and prognosis of breast cancer patients, combined with in vitro experiments to analyze the mechanism of action and immune relevance of ACE2 in breast cancer.Results showed that the expression of ACE2 in breast cancer tissues was significantly lower than that in normal breast tissues, and that its expression was negatively correlated with age, M stage and N1mi stage of breast cancer patients (P < 0.05).Patients with Luminal type breast cancer with high ACE2 expression had poor prognosis, while in the triple-negative breast cancer (TNBC) subtype, ACE2 showed different prognostic significance.In addition, ACE2 is closely associated with the metabolic and immune microenvironment of tumor tissue.In vitro experiments have shown that ACE2 is lowly expressed in MDA-MB-231 cells and may inhibit cell progress by downregulating matrix metalloproteinase 2（MMP2）.The results suggest that the low expression of ACE2 in breast cancer is closely associated with patient prognosis as well as metabolic and immune microenvironment, and that ACE2 may inhibit TNBC cell progress through the MMP2 pathway.

Research progress on immunotherapy for triple-negative breast cancer / 中国临床药理学与治疗学

Triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). It is highly aggressive, easy to relapse, and chemotherapy remains its mainstay treatment due to the lack of therapeutic targets. In recent years, many advances have been made in the development of immunotherapy for TNBC. This review summarizes the primary modalities of immunotherapy for TNBC, including immune checkpoint inhibitors, adoptive immune cell therapy, tumor vaccines and oncolytic virus. We present the latest research progress on each treatment from the perspective of clinical study and fundamental research, while introducing the potential predictive biomarkers and resistance mechanisms of immunotherapy for TNBC.

Engineering cannabidiol synergistic carbon monoxide nanocomplexes to enhance cancer therapy via excessive autophagy

Although carbon monoxide (CO)-based treatments have demonstrated the high cancer efficacy by promoting mitochondrial damage and core-region penetrating ability, the efficiency was often compromised by protective autophagy (mitophagy). Herein, cannabidiol (CBD) is integrated into biomimetic carbon monoxide nanocomplexes (HMPOC@M) to address this issue by inducing excessive autophagy. The biomimetic membrane not only prevents premature drugs leakage, but also prolongs blood circulation for tumor enrichment. After entering the acidic tumor microenvironment, carbon monoxide (CO) donors are stimulated by hydrogen oxide (H2O2) to disintegrate into CO and Mn2+. The comprehensive effect of CO/Mn2+ and CBD can induce ROS-mediated cell apoptosis. In addition, HMPOC@M-mediated excessive autophagy can promote cancer cell death by increasing autophagic flux via class III PI3K/BECN1 complex activation and blocking autolysosome degradation via LAMP1 downregulation. Furthermore, in vivo experiments showed that HMPOC@M+ laser strongly inhibited tumor growth and attenuated liver and lung metastases by downregulating VEGF and MMP9 proteins. This strategy may highlight the pro-death role of excessive autophagy in TNBC treatment, providing a novel yet versatile avenue to enhance the efficacy of CO treatments. Importantly, this work also indicated the applicability of CBD for triple-negative breast cancer (TNBC) therapy through excessive autophagy.

Macrophage-camouflaged epigenetic nanoinducers enhance chemoimmunotherapy in triple negative breast cancer

Chemoimmunotherapy has been approved as standard treatment for triple-negative breast cancer (TNBC), but the clinical outcomes remain unsatisfied. Abnormal epigenetic regulation is associated with acquired drug resistance and T cell exhaustion, which is a critical factor for the poor response to chemoimmunotherapy in TNBC. Herein, macrophage-camouflaged nanoinducers co-loaded with paclitaxel (PTX) and decitabine (DAC) (P/D-mMSNs) were prepared in combination with PD-1 blockade therapy, hoping to improve the efficacy of chemoimmunotherapy through the demethylation of tumor tissue. Camouflage of macrophage vesicle confers P/D-mMSNs with tumor-homing properties. First, DAC can achieve demethylation of tumor tissue and enhance the sensitivity of tumor cells to PTX. Subsequently, PTX induces immunogenic death of tumor cells, promotes phagocytosis of dead cells by dendritic cells, and recruits cytotoxic T cells to infiltrate tumors. Finally, DAC reverses T cell depletion and facilitates immune checkpoint blockade therapy. P/D-mMSNs may be a promising candidate for future drug delivery design and cancer combination therapy in TNBC.

Self-assembly of CXCR4 antagonist peptide-docetaxel conjugates for breast tumor multi-organ metastasis inhibition

As a representative chemotherapeutic drug, docetaxel (DTX) has been used for breast cancer treatment for decades. However, the poor solubility of DTX limits its efficacy, and the DTX based therapy increases the metastasis risk due to the upregulation of C-X-C chemokine receptor type 4 (CXCR4) expression during the treatment. Herein, we conjugated CXCR4 antagonist peptide (CTCE) with DTX (termed CTCE-DTX) as an anti-metastasis agent to treat breast cancer. CTCE-DTX could self-assemble to nanoparticles, targeting CXCR4-upregulated metastatic tumor cells and enhancing the DTX efficacy. Thus, the CTCE-DTX NPs achieved promising efficacy on inhibiting both bone-specific metastasis and lung metastasis of triple-negative breast cancer. Our work provided a rational strategy on designing peptide-drug conjugates with synergistic anti-tumor efficacy.