Triple-negative breast cancer (TNBC) is one of the most difficult subtypes of breast cancer to treat due to its distinct clinical and molecular characteristics. Patients with TNBC face a high recurrence rate, an increased risk of metastasis, and lower overall survival compared to other breast cancer subtypes. Despite advancements in targeted therapies, traditional chemotherapy (primarily using platinum compounds and taxanes) continues to be the standard treatment for TNBC, often with limited long-term efficacy. TNBC tumors are heterogeneous, displaying a diverse mutation profile and considerable chromosomal instability, which complicates therapeutic interventions. The development of chemoresistance in TNBC is frequently associated with the process of epithelial–mesenchymal transition (EMT), during which epithelial tumor cells acquire a mesenchymal-like phenotype. This shift enhances metastatic potential, while simultaneously reducing the effectiveness of standard chemotherapeutics. It has also been suggested that EMT plays a central role in the development of cancer stem cells. Hence, there is growing interest in exploring small-molecule inhibitors that target the EMT process as a future strategy for overcoming resistance and improving outcomes for patients with TNBC. This review focuses on the progression and drug resistance of TNBC with an emphasis on the role of EMT in these processes. We present TNBC-specific and EMT-related molecular features, key EMT protein markers, and various signaling pathways involved. We also discuss other important mechanisms and factors related to chemoresistance in TNBC within the context of EMT, highlighting treatment advancements to improve patients’ outcomes.
Green tea contains a variety of biologically active constituents that are widely used in the pharmaceutical and food industries. Among them, simple catechins constitute a major group of compounds that is primarily responsible for the high biologic activity of green tea extracts. Therefore, the application of optimized extraction conditions may result in obtaining high value extracts. The main purpose of the study was to compare the content of polyphenols, mainly catechins, and the antioxidant activity of green tea extracts obtained by three different extraction methods: simple maceration, ultrasound extraction and accelerated solvent extraction using six various solvent systems. The quality of the extracts was evaluated by LC-ESI-Q-TOF-MS methodologies and spectrophotometric determinations. The obtained results revealed that catechins’ extraction efficiency was identical for the three techniques studied. However, larger quantitative differences among the samples were observed when using different solvents. The total content of major catechins and gallic acid was within a very wide range of 10.2–842 mg/L. Ethyl acetate was by far the least effective extractant, regardless of the extraction technique used. After all, the solvent system composed of ethanol:water (1:1 v/v) was proven to be the best to recover catechins and to deliver extracts with the highest antiradical activity.
Head and neck cancers (HNCs) are heterogeneous and aggressive tumors of the upper aerodigestive tract. Although various histological types exist, the most common is squamous cell carcinoma (HNSCC). The incidence of HNSCC is increasing, making it an important public health concern. Tumor resistance to contemporary treatments, namely, chemo- and radiotherapy, and the recurrence of the primary tumor after its surgical removal cause huge problems for patients. Despite recent improvements in these treatments, the 5-year survival rate is still relatively low. HNSCCs may develop local lymph node metastases and, in the most advanced cases, also distant metastases. A key process associated with tumor progression and metastasis is epithelial–mesenchymal transition (EMT), when poorly motile epithelial tumor cells acquire motile mesenchymal characteristics. These transition cells can invade different adjacent tissues and finally form metastases. EMT is governed by various transcription factors, including the best-characterized TWIST1 and TWIST2, SNAIL, SLUG, ZEB1, and ZEB2. Here, we highlight the current knowledge of the process of EMT in HNSCC and present the main protein markers associated with it. This review focuses on the transcription factors related to EMT and emphasizes their role in the resistance of HNSCC to current chemo- and radiotherapies. Understanding the role of EMT and the precise molecular mechanisms involved in this process may help with the development of novel anti-cancer therapies for this type of tumor.
1 September 2019 in Cancer Management and Research
Introduction: Histone deacetylase inhibitors (HDIs) are a group of compounds that exhibit anticancer activity, but their significance and usefulness in breast cancer (BC) treatment are still controversial. The ability of cancer cells to invade and migrate is augmented by the acquisition of a mesenchymal phenotype – a process known as epithelial-to-mesenchymal transition (EMT). Changes in the expression level of different cadherins, so-called cadherin switches, have been used to monitor the EMT process in development and tumor progression, in particular migration and invasion potential. The aim of this study was to analyze the influence of two HDIs – valproic acid (VPA) and vorinostat (SAHA) – on the migration potential of different BC cell types, as well as on EMT, or its reverse process – mesenchymal-to-epithelial transition, progression by means of shift in epithelial and mesenchymal marker expression. Methods: HDI treatment-induced expression of E- and N-cadherin at the mRNA and protein levels was evaluated by qPCR, Western blotting and immunostaining methods, respectively. BC cell proliferation and migration were assessed by BrdU, xCELLigence system and wound-healing assay. Results: VPA and SAHA inhibited the proliferation and migration in a dose- and time-dependent manner, regardless of the BC cell type. Unawares, BC cells having a more mesenchymal phenotype (MDA-MB-468) were found to overexpress N-cadherin, whereas BC lines having an epithelial phenotype (T47D, MCF7) responded to HDI treatment by a significant increase of E-cadherin expression. Discussion: We suggest that HDAC inhibition results in a more relaxed chromatin concomitant to an increase in the expression of already expressing genes. Conclusion: By using multiple cancer cell lines, we conclude that HDI induction or reversal of EMT is not a universal mechanism, yet inhibition of cell migration is, and thus EMT should not be considered as the only measurement for tumor aggressiveness.
Inflammation is a protective reaction of the innate immune system as a response to imbalances caused by a specific stimulus, a disease or a pathogen. A prolonged inflammatory condition may lead to the development of metabolic syndrome, which affects more than one-fourth of the world’s population. This condition leads to the development of multi-organ disorders based on disrupted blood lipid and sugar levels, hypertension and oxidative stress. The review aims to present Zingiber officinale Rosc. as a plant that exhibits a variety of healing properties and restores the organism’s equilibrium. Ginger (GI) rhizomes have been commonly used in traditional medicine to treat arthritis, stomach ache, nonalcoholic fatty liver disease, rheumatism, nervous system syndromes, asthma, diabetes and nausea caused by pregnancy or chemotherapy. This review gathers together data from in vivo experiments related to the application of ginger for the treatment of inflammatory conditions, obesity, diabetes and other related disorders as a consequence of metabolic syndrome, including the confirmed molecular mechanisms of action.