TGF-β-Induced TMEPAI Attenuates the Response of Triple-Negative Breast Cancer Cells to Doxorubicin and Paclitaxel

An EMT-Related Gene Signature to Predict the Prognosis of Triple-Negative Breast Cancer

INTRODUCTION

Epithelial-mesenchymal transition (EMT) is an important biological process in tumor invasion and metastasis, and thus a potential indicator of the progression and drug resistance of breast cancer. This study comprehensively analyzed EMT-related genes in triple-negative breast cancer (TNBC) to develop an EMT-related prognostic gene signature.

METHODS

With the application of The Cancer Genome Atlas (TCGA) database, Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), and the Genotype-Tissue Expression (GTEx) database, we identified EMT-related signature genes (EMGs) by Cox univariate regression and LASSO regression analysis. Risk scores were calculated and used to divide patients with TNBC into high-risk group and low-risk groups by the median value. Kaplan-Meier (K-M) and receiver operating characteristic (ROC) curve analyses were applied for model validation. Independent prognostic predictors were used to develop nomograms. Then, we assessed the risk model in terms of the immune microenvironment, genetic alteration and DNA methylation effects on prognosis, the probability of response to immunotherapy and chemotherapy, and small molecule drugs predicted by The Connectivity Map (Cmap) database.

RESULTS

Thirteen EMT-related genes with independent prognostic value were identified and used to stratify the patients with TNBC into high- and low-risk groups. The survival analysis revealed that patients in the high-risk group had significantly poorer overall survival than patients in the low-risk group. Populations of immune cells, including CD4 memory resting T cells, CD4 memory activated T cells, and activated dendritic cells, significantly differed between the high- and low-risk groups. Moreover, some therapeutic drugs to which the high-risk group might show sensitivity were identified.

CONCLUSIONS

Our research identified the significant impact of EMGs on prognosis in TNBC, providing new strategies for personalizing TNBC treatment and improving clinical outcomes.

siRNA and targeted delivery systems in breast cancer therapy

Recently, nucleic acid drugs have been considered as promising candidates in treatment of various diseases, especially cancer. Because of developing resistance to conventional chemotherapy, use of genetic tools in cancer therapy appears inevitable. siRNA is a RNAi tool with capacity of suppressing target gene. Owing to overexpression of oncogenic factors in cancer, siRNA can be used for suppressing those pathways. This review emphasizes the function of siRNA in treatment of breast tumor. The anti-apoptotic-related genes including Bcl-2, Bcl-xL and survivin can be down-regulated by siRNA in triggering cell death in breast cancer. STAT3, STAT8, Notch1, E2F3 and NF-κB are among the factors with overexpression in breast cancer that their silencing by siRNA paves the way for impairing tumor proliferation and invasion. The oncogenic mechanisms in drug resistance development in breast tumor such as lncRNAs can be suppressed by siRNA. Furthermore, siRNA reducing P-gp activity can increase drug internalization in tumor cells. Because of siRNA degradation at bloodstream and low accumulation at tumor site, nanoplatforms have been employed for siRNA delivery to suppress breast tumor progression via improving siRNA efficacy in gene silencing. Development of biocompatible and efficient nanostructures for siRNA delivery can make milestone progress in alleviation of breast cancer patients.

Nanomaterial-assisted CRISPR gene-engineering - A hallmark for triple-negative breast cancer therapeutics advancement

Triple-negative breast cancer (TNBC) is the most violent class of tumor and accounts for 20–24% of total breast carcinoma, in which frequently rare mutation occurs in high frequency. The poor prognosis, recurrence, and metastasis in the brain, heart, liver and lungs decline the lifespan of patients by about 21 months, emphasizing the need for advanced treatment. Recently, the adaptive immunity mechanism of archaea and bacteria, called clustered regularly interspaced short palindromic repeats (CRISPR) combined with nanotechnology, has been utilized as a potent gene manipulating tool with an extensive clinical application in cancer genomics due to its easeful usage and cost-effectiveness. However, CRISPR/Cas are arguably the efficient technology that can be made efficient via organic material-assisted approaches. Despite the efficacy of the CRISPR/Cas@nano complex, problems regarding successful delivery, biodegradability, and toxicity remain to render its medical implications. Therefore, this review is different in focus from past reviews by (i) detailing all possible genetic mechanisms of TNBC occurrence; (ii) available treatments and gene therapies for TNBC; (iii) overview of the delivery system and utilization of CRISPR-nano complex in TNBC, and (iv) recent advances and related toxicity of CRISPR-nano complex towards clinical trials for TNBC.

Curcumin Modulates Oxidative Stress, Fibrosis, and Apoptosis in Drug-Resistant Cancer Cell Lines

In cancer management, drug resistance remains a challenge that reduces the effectiveness of chemotherapy. Several studies have shown that curcumin resensitizes cancer cells to chemotherapeutic drugs to overcome resistance. In the present study, we investigate the potential therapeutic role of curcumin in regulating the proliferation of drug-resistant cancers. Six drug-sensitive (MCF7, HCT116, and A549) and -resistant (MCF7/TH, HCT116R, and A549/ADR) cancer cell lines were treated with curcumin followed by an analysis of cytotoxicity, LDH enzyme, total reactive oxygen species, antioxidant enzymes (SOD and CAT), fibrosis markers (TGF-β1 protein, fibronectin, and hydroxyproline), and expression of cellular apoptotic markers (Bcl-2, Bax, Bax/Bcl-2 ratio, Annexin V, cytochrome c, and caspase-8). Additionally, the expression of cellular SIRT1 was estimated by ELISA and RT-PCR analysis. Curcumin treatment at doses of 2.7–54.3 µM significantly reduced the growth of sensitive and resistant cells as supported with decreased viability and increased cellular LDH enzyme of treated cells compared to controls non-treated cells. Curcumin also at doses of 2.7 and 54.3 µM regulated the fibrogenesis by reducing the expression of fibrotic markers in treated cells. Analysis of apoptotic markers indicated increased Bax, Bax, Bax/Bcl-2 ratio, Annexin V, caspase-8, and cytochrome c expression, while Bcl-2 expressions were significantly reduced. In curcumin-treated cells at 2.7 μM, non-significant change in ROS with significant increase in SOD and CAT activity was observed, whereas an increase in ROS with a reduction in respective antioxidant enzymes were seen at higher concentrations along with significant upregulation of SIRT1. In conclusion, the present study shows that curcumin induces anticancer activity against resistant cancer cell lines in a concentration- and time-dependent manner. The protective activities of curcumin against the growth of cancer cells are mediated by modulating oxidative stress, regulating fibrosis, SIRT1 activation, and inducing cellular apoptosis. Therefore, curcumin could be tested as an auxiliary therapeutic agent to improve the prognosis in patients with resistant cancers.

At the Intersection of Cardiology and Oncology: TGFβ as a Clinically Translatable Therapy for TNBC Treatment and as a Major Regulator of Post-Chemotherapy Cardiomyopathy

Simple Summary

Specific/targeted therapies have been shown to be effective in the treatment of certain cancers. Unfortunately, there is currently no targeted therapy for the treatment of triple-negative breast cancer (TNBC), which is why this subtype of breast cancer is associated with poor patient prognosis. While there is an immense focus on the development of new therapies, the issue of cardiotoxicity following chemotherapeutic treatment is commonly overlooked, despite its role as a leading cause of mortality in cancer survivors. This review aims to discuss the connection of TGF-β signaling and its role in modulating cardiac fibrosis and remodeling, as well as its role in TNBC tumor progression, cancer stem cell enrichment, chemoresistance and relapse. Together, we highlight the modulation of TGF-β as a method to target two of the greatest causes of morbidity and mortality in breast cancer patients.

Abstract

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that accounts for the majority of breast cancer-related deaths due to the lack of specific targets for effective treatments. While there is immense focus on the development of novel therapies for TNBC treatment, a persistent and critical issue is the rate of heart failure and cardiomyopathy, which is a leading cause of mortality and morbidity amongst cancer survivors. In this review, we highlight mechanisms of post-chemotherapeutic cardiotoxicity exposure, evaluate how this is assessed clinically and highlight the transforming growth factor-beta family (TGF-β) pathway and its significance as a mediator of cardiomyopathy. We also highlight recent findings demonstrating TGF-β inhibition as a potent method to prevent cardiac remodeling, fibrosis and cardiomyopathy. We describe how dysregulation of the TGF-β pathway is associated with negative patient outcomes across 32 types of cancer, including TNBC. We then highlight how TGF-β modulation may be a potent method to target mesenchymal (CD44⁺/CD24⁻) and epithelial (ALDH^high) cancer stem cell (CSC) populations in TNBC models. CSCs are associated with tumorigenesis, metastasis, relapse, resistance and diminished patient prognosis; however, due to plasticity and differential regulation, these populations remain difficult to target and continue to present a major barrier to successful therapy. TGF-β inhibition represents an intersection of two fields: cardiology and oncology. Through the inhibition of cardiomyopathy, cardiac damage and heart failure may be prevented, and through CSC targeting, patient prognoses may be improved. Together, both approaches, if successfully implemented, would target the two greatest causes of cancer-related morbidity in patients and potentially lead to a breakthrough therapy.

Optimizing sgRNA to Improve CRISPR/Cas9 Knockout Efficiency: Special Focus on Human and Animal Cell

During recent years, clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) technologies have been noticed as a rapidly evolving tool to deliver a possibility for modifying target sequence expression and function. The CRISPR/Cas9 tool is currently being used to treat a myriad of human disorders, ranging from genetic diseases and infections to cancers. Preliminary reports have shown that CRISPR technology could result in valued consequences for the treatment of Duchenne muscular dystrophy (DMD), cystic fibrosis (CF), β-thalassemia, Huntington's diseases (HD), etc. Nonetheless, high rates of off-target effects may hinder its application in clinics. Thereby, recent studies have focused on the finding of the novel strategies to ameliorate these off-target effects and thereby lead to a high rate of fidelity and accuracy in human, animals, prokaryotes, and also plants. Meanwhile, there is clear evidence indicating that the design of the specific sgRNA with high efficiency is of paramount importance. Correspondingly, elucidation of the principal parameters that contributed to determining the sgRNA efficiencies is a prerequisite. Herein, we will deliver an overview regarding the therapeutic application of CRISPR technology to treat human disorders. More importantly, we will discuss the potent influential parameters (e.g., sgRNA structure and feature) implicated in affecting the sgRNA efficacy in CRISPR/Cas9 technology, with special concentration on human and animal studies.

The involvement of epithelial-to-mesenchymal transition in doxorubicin resistance: Possible molecular targets

Considering the fact that cancer cells can switch among various molecular pathways and mechanisms to ensure their progression, chemotherapy is no longer effective enough in cancer therapy. As an anti-tumor agent, doxorubicin (DOX) is derived from Streptomyces peucetius and can induce cytotoxicity by binding to topoisomerase enzymes to suppress DNA replication, leading to apoptosis and cell cycle arrest. However, efficacy of DOX in suppressing cancer progression is restricted by development of drug resistance. Cancer cells elevate their metastasis in triggering DOX resistance. The epithelial-to-mesenchymal transition (EMT) mechanism participates in transforming epithelial cells into mesenchymal cells that have fibroblast-like features. The EMT diminishes intercellular adhesion and enhances migration of cells that are necessary for carcinogenesis. Various oncogenic molecular pathways stimulate EMT in cancer. EMT can induce DOX resistance, and in this way, upstream mediators such as ZEB proteins, microRNAs, Twist1 and TGF-β play a significant role. Identification of molecular pathways involved in EMT regulation and DOX resistance has resulted in using gene therapy such as microRNA transfection and siRNA in overcoming chemoresistance. Furthermore, curcumin and formononetin, owing to their cytotoxicity against cancer cells, can suppress EMT in mediating DOX sensitivity. For promoting efficacy in DOX sensitivity, nanoparticles have been developed for boosting ability in EMT inhibition.

TGF-β-Induced TMEPAI Promotes Epithelial-Mesenchymal Transition in Doxorubicin-Treated Triple-Negative Breast Cancer Cells via SMAD3 and PI3K/AKT Pathway Alteration

Introduction

Epithelial–mesenchymal transition (EMT) and overexpression of drug efflux transporters have been reported to cause doxorubicin resistance. Our previous study indicated that TMEPAI (transmembrane prostate androgen-induced protein) attenuated doxorubicin sensitivity in triple-negative breast cancer cells. However, how TMEPAI contributes to doxorubicin resistance in TNBC remains unclear. Thus, the present study aimed to elucidate the mechanism of TMEPAI in doxorubicin resistance in triple-negative breast cancer cells.

Methods

We used BT549, triple-negative cells wild type (WT), and BT549 TMEPAI knock-out. Both cells were treated with TGF-β 2 ng/mL for 24 hours, followed by TGF-β 2 ng/mL and doxorubicin 12.9 nM for another 24 hours. Afterward, the cells were harvested and counted. Cells were further lysed and used for RT-PCR and Western blot analysis. We determined the expression levels of proliferation, apoptosis, EMT markers, and drug efflux transporters. Additionally, we investigated the expressions of PI3K as well as SMAD3 and AKT phosphorylation.

Results

TNBC cells were shown to be less sensitive to doxorubicin in the presence of TMEPAI. TMEPAI was shown to alleviate the mRNA expressions of apoptosis markers: Bax, Bcl2, Caspase-3, and Caspase-9. Our results indicated that the presence of TMEPAI greatly amplifies EMT and increases drug efflux transporter expressions after doxorubicin treatment. Furthermore, our findings demonstrated that TMEPAI reduced the action of doxorubicin in inhibiting SMAD3 phosphorylation. TMEPAI was also shown to modify the effect of doxorubicin by reducing PI3K expressions and Akt phosphorylation in triple-negative breast cancer cells.

Conclusion

Our findings indicate that TMEPAI promotes EMT and drug efflux transporters at least in part by shifting doxorubicin action from SMAD3 phosphorylation reduction to PI3K/AKT inhibition in triple-negative breast cancer cells.

PMEPA1 Stimulates the Proliferation, Colony Formation of Pancreatic Cancer Cells via the MAPK Signaling Pathway

BACKGROUND

Prostate transmembrane protein androgen-induced 1 (PMEPA1) is reportedly highly expressed in pancreatic cancer (PC). However, its biological role and associated mechanisms have not been addressed in PC progression.

METHODS

PMEPA1 mRNA expression and survival outcome of PC patients were evaluated via the GEPIA website. Lentiviral-mediated shRNA knockdown and ectopic expression of PMEPA1 were implemented in the pancreatic cancer cell line PANC1 cells. CCK-8 and colony formation assays were carried out to assess the biological function of PMEPA1 in PANC1 proliferation and viability. Dual-luciferase reporter assays and RT-qPCR were used to assess the interactive relationship between PMEPA1 and the MAPK signaling pathway.

RESULTS

By analyzing the data from GEPIA, we found that PMEPA1 mRNA expression is overexpressed in PC tissues compared with matched nontumor tissues. PMEPA1-high PC patients are predicted to have a worse prognosis than PMEPA1-low PC patients. We found that PMEPA1 shRNA suppressed PANC1 proliferation and colony formation capacity, while enforced expression of PMEPA1 yielded the opposite results. Mechanical investigations showed that PMEPA1 exerts its tumor-promoting function in pancreatic cancer via activation of the MAPK signaling pathway.

CONCLUSION

PMEPA1 promotes the progression of PC at least partially by activating the MAPK signaling pathway; thus, the PMEPA1/MAPK axis may be a potential therapeutic target in pancreatic cancer.

CRISPR/Cas9 based genome editing for targeted transcriptional control in triple-negative breast cancer

Breast cancer (BC) is the most common type of cancer in women at the global level and the highest mortality rate has been observed with triple-negative breast cancer (TNBC). Accumulation of genetic lesions an aberrant gene expression and protein degradation are considered to underlie the onset of tumorigenesis and metastasis. Therefore, the challenge to identify the genes and molecules that could be potentially used as potent biomarkers for personalized medicine against TNBC with minimal or no associated side effects. Discovery of the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein 9 (Cas9) arrangement and an increasing repertoire of its new variants has provided a much-needed fillip towards editing TNBC genomes. In this review, we discuss the CRISPR/Cas9 genome editing, CRISPR Technology for diagnosis of (Triple-negative breast cancer) TNBC, Drug Resistance, and potential applications of CRISPR/Cas9 and its variants in deciphering or engineering intricate molecular and epigenetic mechanisms associated with TNBC. Furthermore, we have also explored the TNBC and CRISPR/Cas9 genome editing potential for repairing, genetic modifications in TNBC.

Role of non-coding RNAs in modulating the response of cancer cells to paclitaxel treatment

Paclitaxel is a chemotherapeutic substance that is administered for treatment of an extensive spectrum of human malignancies. In spite of its potent short-term effects against tumor cells, resistance to paclitaxel occurs in a number of patients precluding its long-term application in these patients. Non-coding RNAs have been shown to influence response of cancer cells to this chemotherapeutic agent via different mechanisms. Mechanistically, these transcripts regulate expression of several genes particularly those being involved in the apoptotic processes. Lots of in vivo and in vitro assays have demonstrated the efficacy of oligonucleotide-mediated microRNAs (miRNA)/ long non-coding RNAs (lncRNA) silencing in enhancement of response of cancer cells to paclitaxel. Therefore, targeted therapies against non-coding RNAs have been suggested as applicable modalities for combatting resistance to this agent. In the present review, we provide a summary of studies which assessed the role of miRNAs and lncRNAs in conferring resistance to paclitaxel.

Toward Regulatory Effects of Curcumin on Transforming Growth Factor-Beta Across Different Diseases: A Review

Immune response, proliferation, migration and angiogenesis are juts a few of cellular events that are regulated by transforming growth factor-β (TGF-β) in cells. A number of studies have documented that TGF-β undergoes abnormal expression in different diseases, e.g., diabetes, cancer, fibrosis, asthma, arthritis, among others. This has led to great fascination into this signaling pathway and developing agents with modulatory impact on TGF-β. Curcumin, a natural-based compound, is obtained from rhizome and roots of turmeric plant. It has a number of pharmacological activities including antioxidant, anti-inflammatory, anti-tumor, anti-diabetes and so on. Noteworthy, it has been demonstrated that curcumin affects different molecular signaling pathways such as Wnt/β-catenin, Nrf2, AMPK, mitogen-activated protein kinase and so on. In the present review, we evaluate the potential of curcumin in regulation of TGF-β signaling pathway to corelate it with therapeutic impacts of curcumin. By modulation of TGF-β (both upregulation and down-regulation), curcumin ameliorates fibrosis, neurological disorders, liver disease, diabetes and asthma. Besides, curcumin targets TGF-β signaling pathway which is capable of suppressing proliferation of tumor cells and invading cancer cells.

Controlled Drug Delivery Vehicles in Veterinary Oncology: State-of-the-Art and Future Directions

Controlled drug delivery systems can be used to carry several anticancer agents, including classical chemotherapeutic agents such as doxorubicin, paclitaxel or cisplatin, and are also used for the encapsulation of tyrosine kinase inhibitors and monoclonal antibodies. Usually, the controlled systems are used to decrease drug toxicity, increase local drug concentration or target specific organs or systems. In dogs, liposomal doxorubicin is the most known controlled drug delivery vehicle in veterinary medicine. However, several antitumor drugs can be encapsulated within these systems. Since the delivery vehicles are a relatively new topic in veterinary oncology, this review aims to discuss the current knowledge regarding the controlled drug delivery vehicles and discuss the current challenges and future direction of its use in veterinary oncology.