Dual targeted therapy with p53 siRNA and Epigallocatechingallate in a triple negative breast cancer cell model

Arene Ruthenium Complexes Specifically Inducing Apoptosis in Breast Cancer Cells

Monocationic arene ruthenium complexes (RuL1–RuL4) incorporating phenothiazinyl-hydrazinyl-thiazole ligands (L1–L4) have been synthesized, characterized and evaluated as anticancer agents. Their cytotoxicity, antiproliferative activity and alteration of apoptotic gene expression were studied on three cancer cell lines, a double positive breast cancer cell line MCF-7 and two triple negative breast cancer cell lines Hs578T and MDA-MB-231. All arene ruthenium complexes were able to reduce the viability of the breast cancer cell lines, with the highest cytotoxicities being recorded for the [(p-cymene)RuL3Cl]+ (RuL3) complex on the MCF-7 (IC50 = 0.019 µM) and Hs578T cell lines (IC50 = 0.095 µM). In the double positive MCF-7 breast cancer cells, the complexes [(p-cymene)RuL1Cl]+ (RuL1) and [(p-cymene)RuL2Cl]+ (RuL2) significantly upregulated pro-apoptotic genes including BAK, FAS, NAIP, CASP8, TNF, XIAP and BAD, while downregulating TNFSF10. In the triple negative breast cancer cell line Hs578T, RuL1 reduced TNFSF-10 and significantly upregulated BAK, CASP8, XIAP, FADD and BAD, while complex RuL2 also increased BAK and CASP8 expression, but had limited effects on other genes. The triple negative MDA-MB-231 cancer cells treated with RuL1 upregulated NOD1 and downregulated p53, while RuL2 significantly downregulated p53, XIAP and TNFSF10, with minor changes in other genes. The significant alterations in the expression of key apoptotic genes suggest that such complexes have the potential to target cancer cells.

SMAR1 and p53-regulated lncRNA RP11-431M3.1 enhances HIF1A translation via miR-138 in colorectal cancer cells under oxidative stress

Eukaryotic cells respond to stress by altering coding and non-coding gene expression programs. Alongside many approaches and regulatory mechanisms, long non-coding RNAs (lncRNA) are finding a significant place in gene regulation, suggesting an involvement in various cellular processes and pathophysiology. LncRNAs are regulated by many transcription factors, including SMAR1 and p53, which are tumor suppressor genes. SMAR1 inhibits cancer cell metastasis and invasion and is also known to inhibit apoptosis during low-dose stress in coordination with p53. Data mining analysis suggested that these tumor suppressor genes might coregulate the lncRNA RP11-431M3.1 in colon cancer cells. Importantly, RP11-431M3.1 expression was found to be negatively correlated with patient survival rates in a number of cancers. Oxidative stress occurs when an imbalance in the body is caused by reactive oxygen species (ROS). This imbalance is known to be important in the development/pathogenesis of colon cancer. We are researching the role and control of this lncRNA in HCT116 cells under conditions of oxidative stress. We observed a dose-dependent differential expression of lncRNA upon H2O2 treatment and found that p53 and SMAR1 bind differentially to the promoter in response to the dose of stress inducer used. RP11-431M3.1 was observed to sponge miR-138 which has an important target gene, hypoxia-inducible factor (HIF1A). miR-138 was observed to bind differentially to RP11-431M3.1 and HIF1A RNA depending on the dose of oxidative stress. Furthermore, the knockdown of RP11-431M3.1 decreased the migration and proliferation of colon cancer cells. Our results suggest a previously undescribed regulatory mechanism through which RP11-431M3.1 is transcriptionally regulated by SMAR1 and p53, target HIF1A through miR-138, and highlight its potential as a therapeutic and diagnostic marker for cancer.

Therapeutic delivery of siRNA for the management of breast cancer and triple-negative breast cancer

Breast cancer is the leading cause of cancer-related deaths among women globally. The difficulties with anticancer medications, such as ineffective targeting, larger doses, toxicity to healthy cells and side effects, have prompted attention to alternate approaches to address these difficulties. RNA interference by small interfering RNA (siRNA) is one such tactic. When compared with chemotherapy, siRNA has several advantages, including the ability to quickly modify and suppress the expression of the target gene and display superior efficacy and safety. However, there are known challenges and hurdles that limits their clinical translation. Decomposition by endonucleases, renal clearance, hydrophilicity, negative surface charge, short half-life and off-target effects of naked siRNA are obstacles that hinder the desired biological activity of naked siRNA. Nanoparticulate systems such as polymeric, lipid, lipid-polymeric, metallic, mesoporous silica nanoparticles and several other nanocarriers were used for effective delivery of siRNA and to knock down genes involved in breast cancer and triple-negative breast cancer. The focus of this review is to provide a comprehensive picture of various strategies utilized for delivering siRNA, such as combinatorial delivery, development of modified nanoparticles, smart nanocarriers and nanocarriers that target angiogenesis, cancer stem cells and metastasis of breast cancer.

Harnessing the nutriceutics in early-stage breast cancer: mechanisms, combinational therapy, and drug delivery

BACKGROUND

Breast cancer (BC) is a significant health challenge, ranking as the second leading cause of cancer-related death and the primary cause of mortality among women aged 45 to 55. Early detection is crucial for optimal prognosis. Among various treatment options available for cancer, chemotherapy remains the predominant approach. However, its patient-friendliness is hindered by cytotoxicity, adverse effects, multi-drug resistance, potential for recurrence, and high costs. This review explores extensively studied phytomolecules, elucidating their molecular mechanisms. It also emphasizes the importance of combination therapy, highlighting recent advancements in the exploration of diverse drug delivery systems and novel routes of administration. The regulatory considerations are crucial in translating these approaches into clinical practices.

RESULTS

Consequently, there is growing interest in exploring the relationship between diet, cancer, and complementary and alternative medicine (CAM) in cancer chemotherapy. Phytochemicals like berberine, curcumin, quercetin, lycopene, sulforaphane, resveratrol, epigallocatechin gallate, apigenin, genistein, thymoquinone have emerged as promising candidates due to their pleiotropic actions on target cells through multiple mechanisms with minimal toxicity effects. This review focuses on extensively studied phytomolecules, elucidating their molecular mechanisms. It also emphasizes the importance of combination therapy, highlighting recent advancements in the exploration of diverse drug delivery systems and novel routes of administration. The regulatory considerations are crucial in translating these approaches into clinical practices.

CONCLUSION

The present review provides a comprehensive understanding of the molecular mechanisms, coupled with well-designed clinical trials and adherence to regulatory guidelines, which pave the way for nutrition-based combination therapies to become a frontline approach in early-stage BC treatment.

Advances in siRNA Drug Delivery Strategies for Targeted TNBC Therapy

Among breast cancers, triple-negative breast cancer (TNBC) has been recognized as the most aggressive type with a poor prognosis and low survival rate. Targeted therapy for TNBC is challenging because it lacks estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Chemotherapy, radiation therapy, and surgery are the common therapies for TNBC. Although TNBC is prone to chemotherapy, drug resistance and recurrence are commonly associated with treatment failure. Combination therapy approaches using chemotherapy, mAbs, ADC, and antibody-siRNA conjugates may be effective in TNBC. Recent advances with siRNA-based therapy approaches are promising for TNBC therapy with better prognosis and reduced mortality. This review discusses advances in nanomaterial- and nanobiomaterial-based siRNA delivery platforms for TNBC therapy exploring targeted therapy approaches for major genes, proteins, and TFs upregulated in TNBC tumors, which engage in molecular pathways associated with low TNBC prognosis. Bioengineered siRNA drugs targeting one or several genes simultaneously can downregulate desired genes, significantly reducing disease progression.

Epigallocatechin-3-gallate and cancer: focus on the role of microRNAs

MicroRNAs (miRNAs) are a group of small non-coding RNAs that affect gene expression. The role of miRNAs in different types of cancers has been published and it was shown that several miRNAs are inappropriately expressed in different cancers. Among the mechanisms that can cause this lack of proper expression are epigenetics, chromosomal changes, polymorphisms or defects in processing proteins. Recent research shows that phytochemicals, including epigallocatechin-3-gallate (EGCG), exert important epigenetic-based anticancer effects such as pro-apoptotic or anti proliferative through miRNA gene silencing. Given that EGCG is able to modulate a variety of cancer-related process i.e., angiogenesis, proliferation, metastasis and apoptosis via targeting various miRNAs such as let-7, miR-16, and miR-210. The discovery of new miRNAs and the differences observed in their expression when exposed to EGCG provides evidence that targeting these miRNAs may be beneficial as a form of treatment. In this review, we aim to provide an overview, based on current knowledge, on how phytochemicals, including epigallocatechin-3-gallate, can be considered as potential miRNAs modulator to improve efficacy of current cancer treatments.

The Potential Role of Epigallocatechin-3-Gallate (EGCG) in Breast Cancer Treatment

Breast cancer is one of the most diagnosed cancers worldwide, with an incidence of 47.8%. Its treatment includes surgery, radiotherapy, chemotherapy, and antibodies giving a mortality of 13.6%. Breast tumor development is driven by a variety of signaling pathways with high heterogeneity of surface receptors, which makes treatment difficult. Epigallocatechin-3-gallate (EGCG) is a natural polyphenol isolated as the main component in green tea; it has shown multiple beneficial effects in breast cancer, controlling proliferation, invasion, apoptosis, inflammation, and demethylation of DNA. These properties were proved in vitro and in vivo together with synergistic effects in combination with traditional chemotherapy, increasing the effectiveness of the treatment. This review focuses on the effects of EGCG on the functional capabilities acquired by breast tumor cells during its multistep development, the molecular and signal pathways involved, the synergistic effects in combination with current drugs, and how nanomaterials can improve its bioavailability on breast cancer treatment.

New Visions on Natural Products and Cancer Therapy: Autophagy and Related Regulatory Pathways

Macroautophagy (autophagy) has been a highly conserved process throughout evolution and allows cells to degrade aggregated/misfolded proteins, dysfunctional or superfluous organelles and damaged macromolecules, in order to recycle them for biosynthetic and/or energetic purposes to preserve cellular homeostasis and health. Changes in autophagy are indeed correlated with several pathological disorders such as neurodegenerative and cardiovascular diseases, infections, cancer and inflammatory diseases. Conversely, autophagy controls both apoptosis and the unfolded protein response (UPR) in the cells. Therefore, any changes in the autophagy pathway will affect both the UPR and apoptosis. Recent evidence has shown that several natural products can modulate (induce or inhibit) the autophagy pathway. Natural products may target different regulatory components of the autophagy pathway, including specific kinases or phosphatases. In this review, we evaluated ~100 natural compounds and plant species and their impact on different types of cancers via the autophagy pathway. We also discuss the impact of these compounds on the UPR and apoptosis via the autophagy pathway. A multitude of preclinical findings have shown the function of botanicals in regulating cell autophagy and its potential impact on cancer therapy; however, the number of related clinical trials to date remains low. In this regard, further pre-clinical and clinical studies are warranted to better clarify the utility of natural compounds and their modulatory effects on autophagy, as fine-tuning of autophagy could be translated into therapeutic applications for several cancers.

Effects of matcha tea extract on cell viability and peroxisome proliferator-activated receptor γ expression on T47D breast cancer cells

PURPOSE

In the following work, we investigated the nuclear peroxisome proliferator-activated receptor gamma (PPARγ)-dependent proliferation behavior of breast cancer cells after stimulation with matcha green tea extract (MTE).

METHODS

T47D cells were stimulated with MTE at concentrations of 5, 10 and 50 µg/ml. Cell viability was assessed using a WST-1 assay after an incubation time of 72 h. PPARγ expression was quantified at the gene level by real-time polymerase chain reaction (PCR). A western blot (WB) was carried out for the qualitative assessment of the expression behavior of on a protein level.

RESULTS

The WST-1 test showed a significant inhibition of viability in T47D cells after 72 h at 5, 10 and 50 µg/ml. The PCR showed an overexpression of PPARγ in T47D cells in all concentrations. At the concentration of 50 µg/ml the expression was significantly increased (p < 0.05). The WB demonstrated a significant quantitative increase of PPARγ at protein level with MTE concentrations of 10 and 50 µg/ml. In addition, there was a negative correlation between the overexpression of PPAR γ and the inhibition of proliferation.

CONCLUSION

MTE decreases the cell viability of T47D cells and furthermore leads to an overexpression of PPARγ on protein and mRNA level.

Epigallocatechin 3-gallate: From green tea to cancer therapeutics

Epigallocatechin 3-gallate (EGCG) possesses various biological functions, including anti-cancer and anti-inflammatory properties. EGCG is an abundant polyphenolic component originating from green tea extract that has exhibited versatile bioactivities in combating several cancers. This review highlights the pharmacological features of EGCG and its therapeutic implications in cancer and other metabolic diseases. It modulates numerous signaling pathways, regulating cells' undesired survival and proliferation, thus imparting strong tumor chemopreventive and therapeutic effects. EGCG initiates cell death through the intrinsic pathway and causes inhibition of EGFR, STAT3, and ERK pathways in several cancers. EGCG alters and inhibits ERK1/2, NF-κB, and Akt-mediated signaling, altering the Bcl-2 family proteins ratio and activating caspases in tumor cells. This review focuses on anti-cancer, anti-oxidant, anti-inflammatory, anti-angiogenesis, and apoptotic effects of EGCG. We further highlighted the potential of EGCG in different types of cancer, emphasizing clinical trials formulations that further improve our understanding of the therapeutic management of cancer and inflammatory diseases.

Distinct Classes of Flavonoids and Epigallocatechin Gallate, Polyphenol Affects an Oncogenic Mutant p53 Protein, Cell Growth and Invasion in a TNBC Breast Cancer Cell Line

Mutant p53(s) are widely considered as oncogenes and promote several gain-of-function oncogenic activities. p53 mutations correlate with higher rates of metastasis and poor survival; therefore, it is paramount to inhibit mutant p53 protein either directly or indirectly. Although some compounds have been developed, none of them have achieved a desirable level of specificity. Some of these compounds only targeted specific mutations. In search of less-toxic compounds, we tested plant-derived compounds on mutant p53 triple-negative breast cancer cell lines. Here, we show that the compounds tested reduced the protein levels of one of the more frequent oncogenic p53 mutants (R249S; hot spot mutation), and its important targets that promote invasion and metastasis, including GMPS and IMPDH1. All compounds tested perturbed the invasion potential of the breast cancer cell line. These compounds downregulated several nucleotide metabolism genes (NMGs) which are essential for cell cycle progression. We observed S-phase arrest correlating to reduced cell proliferation and increased replication stress. Moreover, we also show a reduction of key ETS transcription family members including ETS2, ETS1, ETV1, and ETV4, which are involved in invasion and metastasis. We propose that these compounds may inhibit invasion by interfering with multiple pathways. Our findings exemplify that these tested compounds could inhibit invasion and cell growth in TNBC in a nucleotide-dependent manner.

Protective Effects of Epigallocatechin Gallate (EGCG) on Endometrial, Breast, and Ovarian Cancers

Green tea and its major bioactive component, (-)-epigallocatechin gallate (EGCG), possess diverse biological properties, particularly antiproliferation, antimetastasis, and apoptosis induction. Many studies have widely investigated the anticancer and synergistic effects of EGCG due to the side effects of conventional cytotoxic agents. This review summarizes recent knowledge of underlying mechanisms of EGCG on protective roles for endometrial, breast, and ovarian cancers based on both in vitro and in vivo animal studies. EGCG has the ability to regulate many pathways, including the activation of nuclear factor erythroid 2-related factor 2 (Nrf2), inhibition of nuclear factor-κB (NF-κB), and protection against epithelial-mesenchymal transition (EMT). EGCG has also been found to interact with DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), which affect epigenetic modifications. Finally, the action of EGCG may exert a suppressive effect on gynecological cancers and have beneficial effects on auxiliary therapies for known drugs. Thus, future clinical intervention studies with EGCG will be necessary to more and clear evidence for the benefit to these cancers.

Advanced Nanovehicles-Enabled Delivery Systems of Epigallocatechin Gallate for Cancer Therapy

Epigallocatechin gallate (EGCG) is the most abundant polyphenolic constituent derived from green tea extract, which has demonstrated versatile bioactivities in combating cardiovascular diseases, neurodegenerative diseases, diabetes, and cancer. In light of its anticancer activity, increasing attention has been paid to developing potent strategies involving EGCG in cancer chemotherapy. However, the poor bioavailability and stability of EGCG limits its effectiveness and practicality in real biomedical applications. To overcome this drawback, nanotechnology-facilitated drug delivery systems have been introduced and intensively explored to enhance the bioavailability and therapeutic efficacy of EGCG in cancer treatments and interventions. This review briefly discusses the anticancer mechanisms of EGCG, and then summarizes recent advances in engineering nanovehicles for encapsulating and delivering EGCG toward cancer therapy. In addition, we also highlight successful integrations of EGCG delivery with other chemotherapies, gene therapies, and phototherapies in one nanostructured entity for a combination therapy of cancers. To conclude, the current challenges and future prospects of the nanovehicle-based transportation systems of EGCG for cancer therapy are also discussed.

Epigenetic Regulation and Dietary Control of Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) represents a highly heterogeneous group of breast cancers, lacking expression of the estrogen (ER) and progesterone (PR) receptors, and human epidermal growth factor receptor 2 (HER2). TNBC are characterized by a high level of mutation and metastasis, poor clinical outcomes and overall survival. Here, we review the epigenetic mechanisms of regulation involved in cell pathways disrupted in TNBC, with particular emphasis on dietary food components that may be exploited for the development of effective strategies for management of TNBC.

Bioengineered siRNA-Based Nanoplatforms Targeting Molecular Signaling Pathways for the Treatment of Triple Negative Breast Cancer: Preclinical and Clinical Advancements

Triple negative breast cancer (TNBC) is one of the most aggressive types of breast cancer. Owing to the absenteeism of hormonal receptors expressed at the cancerous breast cells, hormonal therapies and other medications targeting human epidermal growth factor receptor 2 (HER2) are ineffective in TNBC patients, making traditional chemotherapeutic agents the only current appropriate regimen. Patients' predisposition to relapse and metastasis, chemotherapeutics' cytotoxicity and resistance and poor prognosis of TNBC necessitates researchers to investigate different novel-targeted therapeutics. The role of small interfering RNA (siRNA) in silencing the genes/proteins that are aberrantly overexpressed in carcinoma cells showed great potential as part of TNBC therapeutic regimen. However, targeting specificity, siRNA stability, and delivery efficiency cause challenges in the progression of this application clinically. Nanotechnology was highlighted as a promising approach for encapsulating and transporting siRNA with high efficiency-low toxicity profile. Advances in preclinical and clinical studies utilizing engineered siRNA-loaded nanotherapeutics for treatment of TNBC were discussed. Specific and selective targeting of diverse signaling molecules/pathways at the level of tumor proliferation and cell cycle, tumor invasion and metastasis, angiogenesis and tumor microenvironment, and chemotherapeutics' resistance demonstrated greater activity via integration of siRNA-complexed nanoparticles.

The Role of Epigallocatechin-3-Gallate in Autophagy and Endoplasmic Reticulum Stress (ERS)-Induced Apoptosis of Human Diseases

Tea containing abundant catechins is a popular non-alcoholic beverage worldwide. Epigallocatechin-3-gallate (EGCG) is the predominately active substance in catechins, exhibiting a wide range of functional properties including cancer suppression, neuroprotective, metabolic regulation, cardiovascular protection, stress adjustment, and antioxidant in various diseases. Autophagy, a basic cell function, participates in various physiological processes which include clearing away abnormally folded proteins and damaged organelles, and regulating growth. EGCG not only regulates autophagy via increasing Beclin-1 expression and reactive oxygen species generation, but also causing LC3 transition and decreasing p62 expression. EGCG-induced autophagy is involved in the occurrence and development of many human diseases, including cancer, neurological diseases, diabetes, cardiovascular diseases, and injury. Apoptosis is a common cell function in biology and is induced by endoplasmic reticulum stress (ERS) as a cellular stress response which is caused by various internal and external factors. ERS-induced apoptosis of EGCG influences cell survival and death in various diseases via regulating IRE1, ATF6, and PERK signaling pathways, and activating GRP78 and caspase proteins. The present manuscript reviews that the effect of EGCG in autophagy and ERS-induced apoptosis of human diseases.

Breast Tumor Microenvironment: Emerging target of therapeutic phytochemicals

Triple negative breast cancer (TNBC) is the most aggressive and challenging form of breast cancers. Tumor microenvironment (TME) of TNBC is associated with induction of metastasis, immune system suppression, escaping immune detection and drug resistance. TME is highly complex and heterogeneous, consists of tumor cells, stromal cells and immune cells. The rapid expansion of tumors induce hypoxia, which concerns the reprogramming of TME components. The reciprocal communication of tumor cells and TME cells predisposes cancer cells to metastasis by modulation of developmental pathways, Wnt, notch, hedgehog and their related mechanisms in TME. Dietary phytochemicals are non-toxic and associated with various human health benefits and remarkable spectrum of biological activities. The phytochemicals serve as vital resources for drug discovery and also as a source for breast cancer therapy. The novel properties of dietary phytochemicals propose platform for modulation of tumor signaling, overcoming drug resistance, and targeting TME. Therefore, TME could serve as promising target for the treatment of TNBC. This review presents current status and implications of experimentally evaluated therapeutic phytochemicals as potential targeting agents of TME, potential nanosystems for targeted delivery of phytochemicals and their current challenges and future implications in TNBC treatment. The dietary phytochemicals especially curcumin with significant delivery system could prevent TNBC development as it is considered safe and well tolerated in phase II clinical trials.

Current shreds of evidence on the anticancer role of EGCG in triple negative breast cancer: an update of the current state of knowledge

Triple-Negative Breast Cancer (TNBC), represents a subtype of breast cancer in which the estrogens receptor (ER) negative, the progesterone receptor (PR) negative and the human epidermal growth factor receptor 2 (HER2) negative, are not expressed. Thusly, TNBC does not respond to hormonal therapies or to those targeting the HER2 protein receptors. To overcome this flawed issue, new alternative therapies based on the use of natural substances, as the (-) - epigallocatechin 3-gallate (EGCG), has been proposed. It is largely documented that EGCG, the principal constituent of green tea, has suppressive effects on different types of cancer, including breast cancer, through the regulation of different signaling pathways. Thus, is reasonable to assume that EGCG could be viewed as a therapeutic option for the prevention and the treatment of TNBC. Here, we summarizing these promising results with the scope of turn a light on the potential roles of EGCG in the treatment of TNBC patients.

Advanced Nanovehicles-Enabled Delivery Systems of Epigallocatechin Gallate for Cancer Therapy

Epigallocatechin gallate (EGCG) is the most abundant polyphenolic constituent derived from green tea extract, which has demonstrated versatile bioactivities in combating cardiovascular diseases, neurodegenerative diseases, diabetes, and cancer. In light of its anticancer activity, increasing attention has been paid to developing potent strategies involving EGCG in cancer chemotherapy. However, the poor bioavailability and stability of EGCG limits its effectiveness and practicality in real biomedical applications. To overcome this drawback, nanotechnology-facilitated drug delivery systems have been introduced and intensively explored to enhance the bioavailability and therapeutic efficacy of EGCG in cancer treatments and interventions. This review briefly discusses the anticancer mechanisms of EGCG, and then summarizes recent advances in engineering nanovehicles for encapsulating and delivering EGCG toward cancer therapy. In addition, we also highlight successful integrations of EGCG delivery with other chemotherapies, gene therapies, and phototherapies in one nanostructured entity for a combination therapy of cancers. To conclude, the current challenges and future prospects of the nanovehicle-based transportation systems of EGCG for cancer therapy are also discussed.

Securidaca-saponins are natural inhibitors of AKT, MCL-1, and BCL2L1 in cervical cancer cells

Introduction

Scientific research is beginning to prove the connection between claims by African traditional medicine and the natural chemical specifics contained in medicinal plant Securidaca longipedunculata. Our previous studies showed that two natural saponin fractions (4A3 and 4A4) identified in the plant as triterpenoid glycosides are capable of activating apoptosis on cervical tumor cell lines. Considering this and some critical roles of human papillomavirus (HPV) E6 oncogene on cervical cells, by promoting carcinogenesis and cell survival, it became necessary to investigate the possible pathways for apoptosis transmission.

Methods

Tests conducted on relevant cervical tumor cell lines such as Caski and Bu25TK included the following: MTT assay; scratch assay (to determine cell migration/invasion); fluorescence microscopy with Annexin V–fluorescein isothiocyanate, muscle progenitor cell) and propidium iodide staining; and finally reverse transcriptase quantitative PCR (RT-qPCR) for gene analysis.

Results

Reduced cell proliferation was observed due to activities of 4A3 and 4A4 fractions, with half-maximal inhibitory concentration (IC₅₀) of 7.03 and 16.39 μg/mL, respectively, on Caski cell line. A significant reduction in cell migration occurred within 48 and 72 hours, respectively, for Caski and Bu25TK cell lines. Late apoptosis was activated by 4A3, staining both Annexin V and PI, in contrast to 4A4’s early apoptosis. RT-qPCR data revealed a fold change (FC) inhibition of antiapoptotic proteins such as MCL-1 and BCL2L1, with diminished level of AKT-3, VEGFA, MALAT1, etc. The expression of p53, proapoptotic BAD, and caspase-8 was nonsignificant.

Conclusion

The low expression of AKT-3 and antiapoptotic proteins (MCL-1 and BCL2L1), as well as VEGFA, could simply be an indication for possible suppression of cell survival mechanisms via multiple channels. We therefore conclude that 4A3 and 4A4 fractions mediate activity via the inhibition of phosphatidylinositol-3-OH kinase (PI3K)-AKT/mTOR/NF-kB-dependent antiapoptotic stimuli. Further studies are ongoing to reveal the chemical structures and compositions of these two fractions.

The Epigenetics of Triple-Negative and Basal-Like Breast Cancer: Current Knowledge

Breast cancer has the highest incidence among all malignancies diagnosed in women. Therapies have significantly improved over the years due to extensive molecular and clinical research; in a large number of cases, targeted therapies have provided better prognosis. However, one specific subtype remains elusive to targeted therapies–the triple-negative breast cancer. This immunohistochemically defined subtype is resistant to both endocrine and targeted therapies, leading to its poor prognosis. A field that is of great promise in current cancer research is epigenetics. By studying the epigenetic mechanisms underlying tumorigenesis–DNA methylation, histone modifications, and noncoding RNAs–advances in cancer treatment, diagnosis, and prevention are possible. This review aims to synthesize the epigenetic discoveries that have been made related to the triple-negative breast cancer.

p53 and metabolism: from mechanism to therapeutics

The tumor cell changes itself and its microenvironment to adapt to different situations, including action of drugs and other agents targeting tumor control. Therefore, metabolism plays an important role in the activation of survival mechanisms to keep the cell proliferative potential. The Warburg effect directs the cellular metabolism towards an aerobic glycolytic pathway, despite the fact that it generates less adenosine triphosphate than oxidative phosphorylation; because it creates the building blocks necessary for cell proliferation. The transcription factor p53 is the master tumor suppressor; it binds to more than 4,000 sites in the genome and regulates the expression of more than 500 genes. Among these genes are important regulators of metabolism, affecting glucose, lipids and amino acids metabolism, oxidative phosphorylation, reactive oxygen species (ROS) generation and growth factors signaling. Wild-type and mutant p53 may have opposing effects in the expression of these metabolic genes. Therefore, depending on the p53 status of the cell, drugs that target metabolism may have different outcomes and metabolism may modulate drug resistance. Conversely, induction of p53 expression may regulate differently the tumor cell metabolism, inducing senescence, autophagy and apoptosis, which are dependent on the regulation of the PI3K/AKT/mTOR pathway and/or ROS induction. The interplay between p53 and metabolism is essential in the decision of cell fate and for cancer therapeutics.

Natural Compounds from Herbs that can Potentially Execute as Autophagy Inducers for Cancer Therapy

Accumulated evidence indicates that autophagy is a response of cancer cells to various anti-cancer therapies. Autophagy is designated as programmed cell death type II, and is characterized by the formation of autophagic vacuoles in the cytoplasm. Numerous herbs, including Chinese herbs, have been applied to cancer treatments as complementary and alternative medicines, supplements, or nutraceuticals to dampen the side or adverse effects of chemotherapy drugs. Moreover, the tumor suppressive actions of herbs and natural products induced autophagy that may lead to cell senescence, increase apoptosis-independent cell death or complement apoptotic processes. Hereby, the underlying mechanisms of natural autophagy inducers are cautiously reviewed in this article. Additionally, three natural compounds—curcumin, 16-hydroxycleroda-3,13-dien-15,16-olide, and prodigiosin—are presented as candidates for autophagy inducers that can trigger cell death in a supplement or alternative medicine for cancer therapy. Despite recent advancements in therapeutic drugs or agents of natural products in several cancers, it warrants further investigation in preclinical and clinical studies.

Nutrigenomics in cancer: Revisiting the effects of natural compounds

Nutrigenomics effects have an important role in the manipulation of dietary components for human benefit, particularly in cancer prevention or treatment. The impact of dietary components, including phytochemicals, is largely studied by nutrigenomics, looking at the gene expression and molecular mechanisms interacting with bioactive compounds and nutrients, based on new 'omics' technologies. The high number of preclinical studies proves the relevant role of nutrigenomics in cancer management. By deciphering the network of nutrient-gene connections associated with cancer, relevant data will be transposed as therapeutic interventions for this devastating pathology and for fulfilling the concept of personalized nutrition. All these are presented under the nutrigenomics canopy for a better comprehension of the relation between ingested phytochemicals and chemoprevention or chemotherapy. The profits from the nutrigenomics progress, with a particular focus on the coding and noncoding genes related to the exposure of natural compounds need to be validated. A precise attention receives the evaluation of the role of natural compounds in tandem with conventional therapy using genomic approaches, with emphasis on the capacity to inhibit drug resistance mechanisms. All these relevant nutrigenomics aspects are summarized in the present review paper. It is concluded that further nutrigenomics studies are required to improve our understanding related to the complex mechanisms of action of the natural compounds and for their appropriate application as gears in cancer therapy.

Epigallocatechin-3-gallate promotes apoptosis in human breast cancer T47D cells through down-regulation of PI3K/AKT and Telomerase

BACKGROUND

Green tea has antioxidant, anti-tumor and anti-bacterial properties. Epigallocatechin-3-gallate (EGCG) in green tea is highly active as a cancer chemopreventive agent. In this study, we designed a series of experiments to examine the effects of EGCG on proliferation and apoptosis of estrogen receptor α-positive breast cancer (T47D) cells.

METHODS

Cells were treated with EGCG (0-80μM) and tamoxifen (0-20μM), as the positive control, up to 72h. Cell viability was determined by MTT assay. Apoptosis investigated by real time PCR of apoptosis and survival (Bax, Bcl-2, p21, p53, PTEN, PI3K, AKT, caspase3 and caspase9 and hTERT) genes and by western blot of Bax/Bcl-2 proteins expressions.

RESULTS

The results showed that EGCG decreased cell viability as concentration- and time-dependently. IC₅₀ values were 14.17μM for T47D and 193.10μM for HFF cells, as compared with 3.39μM and 32.75μM for tamoxifen after 72h treatment, respectively. Also, EGCG (80μM) significantly increased the genes of PTEN, CASP3, CASP9 and decreased AKT approximately equal to tamoxifen. In gene expression, EGCG (80μM) significantly increased Bax/Bcl-2 ratio to 8-fold vise 15-fold in tamoxifen (20μM)-treated T47D cells during 72h. In protein expression of Bax/Bcl-2, EGCG significantly increased 6-fold while this ratio augmented 10-fold in tamoxifen group. EGCG significantly decreased 0.8, 0.4 and 0.3 gene expression of hTERT in 24, 48 and 72h, respectively.

CONCLUSIONS

This study suggests that EGCG may be a useful adjuvant therapeutic agent for the treatment of breast cancer.

Genome-wide effects of MELK-inhibitor in triple-negative breast cancer cells indicate context-dependent response with p53 as a key determinant

Triple-negative breast cancer (TNBC) is an aggressive, highly recurrent breast cancer subtype, affecting approximately one-fifth of all breast cancer patients. Subpopulations of treatment-resistant cancer stem cells within the tumors are considered to contribute to disease recurrence. A potential druggable target for such cells is the maternal embryonic leucine-zipper kinase (MELK). MELK expression is upregulated in mammary stem cells and in undifferentiated cancers, where it correlates with poor prognosis and potentially mediates treatment resistance. Several MELK inhibitors have been developed, of which one, OTSSP167, is currently in clinical trials. In order to better understand how MELK and its inhibition influence TNBC, we verified its anti-proliferative and apoptotic effects in claudin-low TNBC cell lines MDA-MB-231 and SUM-159 using MTS assays and/or trypan blue viability assays together with analysis of PARP cleavage. Then, using microarrays, we explored which genes were affected by OTSSP167. We demonstrate that different sets of genes are regulated in MDA-MB-231 and SUM-159, but in both cell lines genes involved in cell cycle, mitosis and protein metabolism and folding were regulated. We identified p53 (TP53) as a potential upstream regulator of the regulated genes. Using western blot we found that OTSSP167 downregulates mutant p53 in all tested TNBC cell lines (MDA-MB-231, SUM-159, and BT-549), but upregulates wild-type p53 in the luminal A subtype MCF-7 cell line. We propose that OTSSP167 might have context-dependent or off-target effects, but that one consistent mechanism of action could involve the destabilization of mutant p53.

Knocking down of p53 triggers apoptosis and autophagy, concomitantly with inhibition of migration on SSC-4 oral squamous carcinoma cells

Oral squamous cell carcinoma (OSCC) is a malignancy with elevated prevalence and somber prognosis due to the fact that most of the patients are diagnosed at an advanced stage. p53 has a crucial role in proliferation and apoptosis during the occurrence and development of numerous malignant tumors. The impact of mutated p53 on the development and progression of OSCC is unclear and might have therapeutic implications. Using an in vitro RNA interference experiment, we have evaluated the impact of p53 knockdown on cell viability, apoptosis, migration, and gene expression for key genes involved in apoptosis and angiogenesis. We observed that inhibiting the expression of p53 decreased the proliferation ability and induced apoptosis/autophagy in SSC-4 cells. Moreover, we observed that this has decreased migration and has blocked the expression of VEGF. In conclusion, our research provides a proof that a direct connection between p53 knockdown and OSCC cell death can be established, therefore opening new potential directions in OSCC molecular therapeutics and management.

Oligonucleotide-based theranostic nanoparticles in cancer therapy

Theranostic approaches, combining the functionality of both therapy and imaging, have shown potential in cancer nanomedicine. Oligonucleotides such as small interfering RNA and microRNA, which are powerful therapeutic agents, have been effectively employed in theranostic systems against various cancers. Nanoparticles are used to deliver oligonucleotides into tumors by passive or active targeting while protecting the oligonucleotides from nucleases in the extracellular environment. The use of quantum dots, iron oxide nanoparticles and gold nanoparticles and tagging with contrast agents, like fluorescent dyes, optical or magnetic agents and various radioisotopes, has facilitated early detection of tumors and evaluation of therapeutic efficacy. In this article, we review the advantages of theranostic applications in cancer therapy and imaging, with special attention to oligonucleotide-based therapeutics.

Histone deacetylase inhibitors suppress mutant p53 transcription via HDAC8/YY1 signals in triple negative breast cancer cells

There is an urgent need to investigate the potential targeted therapy approach for triple-negative breast cancer (TNBC). Our present study reveals that histone deacetylase inhibitors (HDACIs) suberoyl anilide hydroxamic acid (SAHA) and sodium butyrate (NaB) significantly inhibit cell proliferation, arrest cell cycle at G0/G1 phase, and induce mitochondrial related apoptosis of TNBC cells. Further, SAHA and NaB decrease the phosphorylation, protein and mRNA levels of mutant p53 (mtp53) in TNBC cells. While SAHA or NaB has no similar inhibition effect on wild type p53 (wtp53). The inhibition apparently occurs at the level of transcription because the down regulation of precursor p53 transcription is much more rapid (less than 2h) and sharp than that of mature p53. The knockdown of HDAC8, while not HDAC6, inhibits the transcription of mtp53 in TNBC cells. The luciferase assay and ChIP analysis reveal that both SAHA and NaB can reduce the binding of transcription factor Yin Yang 1 (YY1) with the -102 to -96 position of human p53 promoter. Knockdown of YY1 also significantly inhibits the transcription of mtp53 in TNBC cells. Further, SAHA and NaB can inhibit the association of HDAC8 and YY1, increase acetylation of residues 170-200 of YY1, then decrease its transcription activities, and finally suppress YY1 induced p53 transcription. Together, our data establish that SAHA and NaB can be considered as drug candidates for TNBC patients, and HDAC8/YY1/mtp53 signals act as an important target for TNBC treatment.

Chemoprevention of Breast Cancer by Dietary Polyphenols

The review will discuss in detail the effects of polyphenols on breast cancer, including both the advantages and disadvantages of the applications of these natural compounds. First, we focus on the characterization of the main classes of polyphenols and then on in vitro and in vivo experiments carried out in breast cancer models. Since the therapeutic effects of the administration of a single type of polyphenol might be limited because of the reduced bioavailability of these drugs, investigations on combination of several polyphenols or polyphenols with conventional therapy will also be discussed. In addition, we present recent data focusing on clinical trials with polyphenols and new approaches with nanoparticles in breast cancer. Besides the clinical and translational findings this review systematically summarizes our current knowledge about the molecular mechanisms of anti-cancer effects of polyphenols, which are related to apoptosis, cell cycle regulation, plasma membrane receptors, signaling pathways and epigenetic mechanisms. At the same time the effects of polyphenols on primary tumor, metastasis and angiogenesis in breast cancer are discussed. The increasing enthusiasm regarding the combination of polyphenols and conventional therapy in breast cancer might lead to additional efforts to motivate further research in this field.