Response of tertiary centres to pressure changes. Is there a mechano-electrical association?

Potential Benefits of Green Tea in Prostate Cancer Prevention and Treatment: A Comprehensive Review

Prostate cancer is a prevalent and debilitating disease that necessitates effective prevention and treatment strategies. Green tea, a well-known beverage derived from the Camellia sinensis plant, contains bioactive compounds with potential health benefits, including catechins and polyphenols. This comprehensive review aims to explore the potential benefits of green tea in prostate cancer prevention and treatment by examining existing literature. Green tea possesses antioxidant, anti-inflammatory, and anti-carcinogenic properties attributed to its catechins, particularly epigallocatechin gallate. Epidemiological studies have reported an inverse association between green tea consumption and prostate cancer risk, with potential protection against aggressive forms of the disease. Laboratory studies demonstrate that green tea components inhibit tumor growth, induce apoptosis, and modulate signaling pathways critical to prostate cancer development and progression. Clinical trials and human studies further support the potential benefits of green tea. Green tea consumption has been found to be associated with a reduction in prostate-specific antigen levels, tumor markers, and played a potential role in slowing disease progression. However, challenges remain, including optimal dosage determination, formulation standardization, and conducting large-scale, long-term clinical trials. The review suggests future research should focus on combinatorial approaches with conventional therapies and personalized medicine strategies to identify patient subgroups most likely to benefit from green tea interventions.

Possible Side Effects of Polyphenols and Their Interactions with Medicines

Polyphenols are an important component of plant-derived food with a wide spectrum of beneficial effects on human health. For many years, they have aroused great interest, especially due to their antioxidant properties, which are used in the prevention and treatment of many diseases. Unfortunately, as with any chemical substance, depending on the conditions, dose, and interactions with the environment, it is possible for polyphenols to also exert harmful effects. This review presents a comprehensive current state of the knowledge on the negative impact of polyphenols on human health, describing the possible side effects of polyphenol intake, especially in the form of supplements. The review begins with a brief overview of the physiological role of polyphenols and their potential use in disease prevention, followed by the harmful effects of polyphenols which are exerted in particular situations. The individual chapters discuss the consequences of polyphenols’ ability to block iron uptake, which in some subpopulations can be harmful, as well as the possible inhibition of digestive enzymes, inhibition of intestinal microbiota, interactions of polyphenolic compounds with drugs, and impact on hormonal balance. Finally, the prooxidative activity of polyphenols as well as their mutagenic, carcinogenic, and genotoxic effects are presented. According to the authors, there is a need to raise public awareness about the possible side effects of polyphenols supplementation, especially in the case of vulnerable subpopulations.

Pharmacological Properties of 4', 5, 7-Trihydroxyflavone (Apigenin) and Its Impact on Cell Signaling Pathways

Plant bioactive compounds, particularly apigenin, have therapeutic potential and functional activities that aid in the prevention of infectious diseases in many mammalian bodies and promote tumor growth inhibition. Apigenin is a flavonoid with low toxicities and numerous bioactive properties due to which it has been considered as a traditional medicine for decades. Apigenin shows synergistic effects in combined treatment with sorafenib in the HepG2 human cell line (HCC) in less time and statistically reduces the viability of tumor cells, migration, gene expression and apoptosis. The combination of anti-cancerous drugs with apigenin has shown health promoting potential against various cancers. It can prevent cell mobility, maintain the cell cycle and stimulate the immune system. Apigenin also suppresses mTOR activity and raises the UVB-induced phagocytosis and reduces the cancerous cell proliferation and growth. It also has a high safety threshold, and active (anti-cancer) doses can be gained by consuming a vegetable and apigenin rich diet. Apigenin also boosted autophagosome formation, decreased cell proliferation and activated autophagy by preventing the activity of the PI3K pathway, specifically in HepG2 cells. This paper provides an updated overview of apigenin's beneficial anti-inflammatory, antibacterial, antiviral, and anticancer effects, making it a step in the right direction for therapeutics. This study also critically analyzed the effect of apigenin on cancer cell signaling pathways including the PI3K/AKT/MTOR, JAK/STAT, NF-κB and ERK/MAPK pathways.

Valorization of Onion Waste by Obtaining Extracts Rich in Phenolic Compounds and Feasibility of Its Therapeutic Use on Colon Cancer

In this study, the total phenolic content, the antioxidant and antiproliferative activities of onion waste extracts were characterized. Some phenolic compounds present in the extracts were also identified and quantified by HPLC-DAD. Additionally, an in-silico analysis was performed to identify the phenolic compounds with the highest intestinal absorption and Caco-2 permeability. The onion extract possessed a high amount of phenolic compounds (177 ± 9 mg/g extract) and had an effective antioxidant capacity measured by ABTS, FRAP and DPPH assays. Regarding the antiproliferative activity, the onion extracts produced cell cycle arrest in the S phase with p53 activation, intrinsic apoptosis (mitochondrial membrane potential modification) and caspase 3 activation. Likewise, onion waste increased intracellular ROS with possible NF-kB activation causing a proteasome down regulation. In addition, the extracts protected the intestine against oxidative stress induced by H₂O₂. According to the in-silico analysis, these results could be related to the higher Caco-2 permeability to protocatechuic acid. Therefore, this study provides new insights regarding the potential use of these types of extract as functional ingredients with antioxidant and antiproliferative properties and as medicinal agents in diseases related to oxidative stress, such as cancer. In addition, its valorization would contribute to the circular economy.

Comparative Cytotoxic Activity of Hydroxytyrosol and Its Semisynthetic Lipophilic Derivatives in Prostate Cancer Cells

A high adherence to a Mediterranean diet has been related to numerous beneficial effects in human health, including a lower incidence and mortality of prostate cancer (PCa). Olive oil is an important source of phenolic bioactive compounds, mainly hydroxytyrosol (HT), of this diet. Because of the growing interest of this compound and its derivatives as a cancer chemopreventive agent, we aimed to compare the in vitro effect of HT isolated from olive mill wastewaters and five semisynthetic alkyl ether, ester, and nitro-derivatives against prostate cancer (PCa) cell lines. The effect in cell proliferation was determined in RWPE-1, LNCaP, 22Rv1, and PC-3 cells by resazurin assay, the effect in cell migration by wound healing assay, and tumorsphere and colony formation were evaluated. The changes in key signaling pathways involved in carcinogenesis were assessed by using a phosphorylation pathway profiling array and by Western blotting. Antiproliferative effects of HT and two lipophilic derivatives [hydroxytyrosyl acetate (HT-Ac)/ethyl hydroxytyrosyl ether (HT-Et)] were significantly higher in cancerous PC-3 and 22Rv1 cells than in non-malignant RWPE-1 cells. HT/HT-Ac/HT-Et significantly reduced migration capacity in RWPE-1 and PC-3 and prostatosphere size and colony formation in 22Rv1, whereas only HT-Ac and HT-Et reduced these functional parameters in PC-3. The cytotoxic effect in 22Rv1 cells was correlated with modifications in the phosphorylation pattern of key proteins, including ERK1/2 and AKT. Consistently, HT-Ac and HT-Et decreased p-AKT levels in PC-3. In sum, our results suggest that HT and its lipophilic derivatives could be considered as potential therapeutic tools in PCa.

Tea bioactive components prevent carcinogenesis via anti-pathogen, anti-inflammation, and cell survival pathways

Cancer seriously impairs human health and survival. Many perturbations, such as increased oxidative stress, pathogen infection, and inflammation, promote the accumulation of DNA mutations, and ultimately lead to carcinogenesis. Tea is one of the most highly consumed beverages worldwide and has been linked to improvements in human health. Tea contains many active components, including tea polyphenols, tea polysaccharides, L-theanine, tea pigments, and caffeine among other common components. Several studies have identified components in tea that can directly or indirectly reduce carcinogenesis with some being used in a clinical setting. Many previous studies, in vitro and in vivo, have focused on the mechanisms that functional components of tea utilized to protect against cancer. One particular mechanism that has been well described is an improvement in antioxidant capacity seen with tea consumption. However, other mechanisms, including anti-pathogen, anti-inflammation and alterations in cell survival pathways, are also involved. The current review focuses on these anti-cancer mechanisms. This will be beneficial for clinical utilization of tea components in preventing and treating cancer in the future.

p53 Enhances Artemisia annua L. Polyphenols-Induced Cell Death Through Upregulation of p53-Dependent Targets and Cleavage of PARP1 and Lamin A/C in HCT116 Colorectal Cancer Cells

Plant-derived natural polyphenols exhibit anticancer activity without showing any noticeable toxicities to normal cells. The aim of this study was to investigate the role of p53 on the anticancer effect of polyphenols isolated from Korean Artemisia annua L. (pKAL) in HCT116 human colorectal cancer cells. We confirmed that pKAL induced reactive oxygen species (ROS) production, propidium iodide (PI) uptake, nuclear structure change, and acidic vesicles in a p53-independent manner in p53-null HCT116 cells through fluorescence microscopy analysis of DCF/PI-, DAPI-, and AO-stained cells. The pKAL-induced anticancer effects were found to be significantly higher in p53-wild HCT116 cells than in p53-null by hematoxylin staining, CCK-8 assay, Western blot, and flow cytometric analysis of annexin V/PI-stained cells. In addition, expression of ectopic p53 in p53-null cells was upregulated by pKAL in both the nucleus and cytoplasm, increasing pKAL-induced cell death. Moreover, Western bot analysis revealed that pKAL-induced cell death was associated with upregulation of p53-dependent targets such as p21, Bax and DR5 and cleavage of PARP1 and lamin A/C in p53-wild HCT116 cells, but not in p53-null. Taken together, these results indicate that p53 plays an important role in enhancing the anticancer effects of pKAL by upregulating p53 downstream targets and inducing intracellular cell death processes.

Marine alkaloid monanchoxymycalin C: a new specific activator of JNK1/2 kinase with anticancer properties

Monanchoxymycalin C (MomC) is a new marine pentacyclic guanidine alkaloid, recently isolated from marine sponge Monanchora pulchra by us. Here, anticancer activity and mechanism of action was investigated for the first time using a human prostate cancer (PCa) model. MomC was active in all PCa cell lines at low micromolar concentrations and induced an unusual caspase-independent, non-apoptotic cell death. Kinase activity screening identified activation of mitogen-activated protein kinase (MAPK) c-Jun N-terminal protein kinase (JNK1/2) to be one of the primary molecular mechanism of MomC anticancer activity. Functional assays demonstrated a specific and selective JNK1/2 activation prior to the induction of other cell death related processes. Inhibition of JNK1/2 by pretreatment with the JNK-inhibitor SP600125 antagonized cytotoxic activity of the marine compound. MomC caused an upregulation of cytotoxic ROS. However, in contrast to other ROS-inducing agents, co-treatment with PARP-inhibitor olaparib revealed antagonistic effects indicating an active PARP to be necessary for MomC activity. Interestingly, although no direct regulation of p38 and ERK1/2 were detected, active p38 kinase was required for MomC efficacy, while the inhibition of ERK1/2 increased its cytotoxicity. In conclusion, MomC shows promising activity against PCa, which is exerted via JNK1/2 activation and non-apoptotic cell death.

Anti-cancer effects of polyphenols via targeting p53 signaling pathway: updates and future directions

The anticancer effects of polyphenols are ascribed to several signaling pathways including the tumor suppressor gene tumor protein 53 (p53). Expression of endogenous p53 is silent in various types of cancers. A number of polyphenols from a wide variety of dietary sources could upregulate p53 expression in several cancer cell lines through distinct mechanisms of action. The aim of this review is to focus the significance of p53 signaling pathways and to provide molecular intuitions of dietary polyphenols in chemoprevention by monitoring p53 expression that have a prominent role in tumor suppression.

Antitumor Potential and Phytochemical Profile of Plants from Sardinia (Italy), a Hotspot for Biodiversity in the Mediterranean Basin

Sardinia (Italy), with its wide range of habitats and high degree of endemism, is an important area for plant-based drug discovery studies. In this work, the antitumor activity of 35 samples from Sardinian plants was evaluated on human osteosarcoma cells U2OS. The results showed that five plants were strongly antiproliferative: Arbutus unedo (AuL), Cynara cardunculus (CyaA), Centaurea calcitrapa (CcA), Smilax aspera (SaA), and Tanacetum audibertii (TaA), the latter endemic to Sardinia and Corsica. Thus, their ability to induce cell cycle arrest and apoptosis was tested. All extracts determined cell cycle block in G2/M phase. Nevertheless, the p53 expression levels were increased only by TaA. The effector caspases were activated mainly by CycA, TaA, and CcA, while AuL and SaA did not induce apoptosis. The antiproliferative effects were also tested on human umbilical vein endothelial cells (HUVEC). Except for AuL, all the extracts were able to reduce significantly cell population, suggesting a potential antiangiogenic activity. The phytochemical composition was first explored by 1H NMR profiling, followed by further purifications to confirm the structure of the most abundant metabolites, such as phenolic compounds and sesquiterpene lactones, which might play a role in the measured bioactivity.

Dietary Compounds as Epigenetic Modulating Agents in Cancer

Epigenetic mechanisms control gene expression during normal development and their aberrant regulation may lead to human diseases including cancer. Natural phytochemicals can largely modulate mammalian epigenome through regulation of mechanisms and proteins responsible for chromatin remodeling. Phytochemicals are mainly contained in fruits, seeds, and vegetables as well as in foods supplements. These compounds act as powerful cellular antioxidants and anti-carcinogens agents. Several dietary compounds such as catechins, curcumin, genistein, quercetin and resveratrol, among others, exhibit potent anti-tumor activities through the reversion of epigenetic alterations associated to oncogenes activation and inactivation of tumor suppressor genes. In this review, we summarized the actual knowledge about the role of dietary phytochemicals in the restoration of aberrant epigenetic alterations found in cancer cells with a particular focus on DNA methylation and histone modifications. Furthermore, we discussed the mechanisms by which these natural compounds modulate gene expression at epigenetic level and described their molecular targets in diverse types of cancer. Modulation of epigenetic activities by phytochemicals will allow the discovery of novel biomarkers for cancer prevention, and highlights its potential as an alternative therapeutic approach in cancer.

Anti-tumor activity and the mechanism of a green tea (Camellia sinensis) polysaccharide on prostate cancer

In this study, a homogeneous polysaccharide (GTP), with a molecular weight of 7.0 × 10⁴ Da, was isolated from Green tea, which was only composed of glucose. The antitumor effects of GTP on prostate cancer (PC) cell line along with the possible mechanism was examined. First, we investigate the potential role of microRNA-93 (miR-93) in PC progression. Our results showed that miR-93 was significantly upregulated in human PC tissues and several PC cell lines, and its overexpression was correlated with poor survival in PC patients. Furthermore, functional analysis showed that miR-93 overexpression promoted the migration, invasion and proliferation of PC-3 cells transfected with miR-93 mimics, while its knockdown displayed an opposite result in DU145 cells following miR-93 inhibitor transfection. Additionally, in vivo tumorigenic studies on nude mice confirmed that miR-93 mimic treatment accelerated the growth of PC-3 xenograft tumors. As expected, GTP (25, 50 and 100 μg/ml) inhibited growth of PC-3 cells via inducing apoptosis, which was achieved by elevation of bax/bcl-2 ratio and caspae-3 protein expression, as well as a decrease of miR-93. Thus, miR-93 may be a potential therapeutic target by GTP for PC therapy.

Perspectives on the recent developments with green tea polyphenols in drug discovery

INTRODUCTION

Increasing evidence has expanded the role of green tea from a traditional beverage to a source of pharmacologically active molecules with diverse health benefits. However, conclusive clinical results are needed to better elucidate the cancer-preventive and therapeutic effects of green tea polyphenols (GTPs). Areas covered: The authors describe GTPs' chemical compositions and metabolic biotransformations, and their recent developments in drug discovery, focusing on their cancer chemopreventive and therapeutic effects. They then review the recent development of GTP-loaded nanoparticles and GTP prodrugs. Expert opinion: GTPs possess potent anticarcinogenic activities through interfering with the initiation, development and progression phases of cancer. There are several challenges (e.g. poor bioavailability) in developing GTPs as therapeutic agents. Use of nanoparticle-based delivery systems has provided unique advantages over purified GTPs. However, there is still a need to determine the actual magnitude and pharmacological mechanisms of GTPs encapsulated in nanoparticles, in order to address newly emerging safety issues associated with the potential 'local overdose' effect. The use of Pro- epigallocatechin gallate (Pro-EGCG) as a prodrug appears to offer improved in vitro stability as well as better in vivo bioavailability and efficacies in a number of animal studies, suggesting its potential as a therapeutic agent for further study and development.

Tea polyphenols induce S phase arrest and apoptosis in gallbladder cancer cells

Gallbladder cancer (GBC) is the most common malignancy in the biliary tract. Without effective treatment, its prognosis is notoriously poor. Tea polyphenols (TPs) have many pharmacological and health benefits, including antioxidant, anti-inflammatory, anti-tumor, anti-thrombotic, antibacterial, and vasodilatory properties. However, the anti-cancer effect of TPs in human gallbladder cancer has not yet been determined. Cell viability and colony formation assay were used to investigate the cell growth. Cell cycle and apoptosis were evaluated by flow cytometry analysis. Western blot assay was used to detect the expression of proteins related to cell cycle and apoptosis. Human tumor xenografts were used to examine the effect of TPs on gallbladder cancer cells in vivo. TPs significantly inhibited cell growth of gallbladder cancer cell lines in a dose- and time-dependent manner. Cell cycle progression in GBC cells was blocked at the S phase by TPs. TPs also induced mitochondrial-related apoptosis in GBC cells by upregulating Bax, cleaved caspase-3, and cleaved PARP expressions and downregulating Bcl-2, cyclin A, and Cdk2 expressions. The effects of TPs on GBC were further proven in vivo in a mouse xenograft model. Our study is the first to report that TPs inhibit GBC cell growth and these compounds may have potential as novel therapeutic agents for treating gallbladder cancer.

Fruit Peel Polyphenolic Extract-Induced Apoptosis in Human Breast Cancer Cells Is Associated with ROS Production and Modulation of p38MAPK/Erk1/2 and the Akt Signaling Pathway

Polyphenols represent a large group of natural substances with different biological properties. Currently, polyphenols are well studied due to their free radicals' scavenging and antioxidant activities. However, some studies indicate that polyphenols also exhibit pro-oxidant properties. In this study, the possible involvement of the pro-oxidant activities of fruit polyphenols was investigated in relation to apoptosis induction. To determine the type of cell death induced by fruit polyphenols (Flavine; F7), we assessed a series of assays, including measurements of caspase-7 activation, membrane mitochondrial potential changes, reactive oxygen (ROS) and nitrogen species production, lipid peroxidation, antioxidant enzymes activities, and PARP cleavage. Moreover, the effect of F7 on selected pro- and antisurvival signaling pathways was determined. We demonstrated that fruit polyphenols induced caspase-dependent cell death associated with increased oxidative stress. We also showed fruit polyphenol-mediated release of mitochondrial pro- and antiapoptotic proteins of the Bcl-2 family and modulation activity of the Akt, p38 MAPK, and Erk 1/2 pathways as well as the signaling of ROS-mediated DNA damage. Our data demonstrated that fruit peel polyphenols suppressed breast cancer cell growth through increased intracellular oxidative stress and the activation of p38 MAPK and de-activation of the Erk 1/2 and Akt signaling pathways.

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.

Anticancer Natural Compounds as Epigenetic Modulators of Gene Expression

Accumulating evidence shows that hallmarks of cancer include: "genetic and epigenetic alterations leading to inactivation of cancer suppressors, overexpression of oncogenes, deregulation of intracellular signaling cascades, alterations of cancer cell metabolism, failure to undergo cancer cell death, induction of epithelial to mesenchymal transition, invasiveness, metastasis, deregulation of immune response and changes in cancer microenvironment, which underpin cancer development". Natural compounds as bioactive ingredients isolated from natural sources (plants, fungi, marine life forms) have revolutionized the field of anticancer therapeutics and rapid developments in preclinical studies are encouraging. Natural compounds could affect the epigenetic molecular mechanisms that modulate gene expression, as well as DNA damage and repair mechanisms. The current review will describe the latest achievements in using naturally produced compounds targeting epigenetic regulators and modulators of gene transcription in vitro and in vivo to generate novel anticancer therapeutics.

Gelsolin-like actin-capping protein is associated with patient prognosis, cellular apoptosis and proliferation in prostate cancer

AIM

To investigate the role of gelsolin-like actin-capping protein (CapG) in prostate cancer (PCa).

MATERIALS & METHODS

CapG expression and its correlation with clinicopathological characters and patient prognosis were analyzed in 76 cases of PCa by immunohistochemistry and qRT-PCR. Then, the influence of CapG downregulation on cell apoptosis and proliferation were assessed.

RESULTS

CapG expression in PCa was significantly higher compared with those in matched adjacent noncancerous prostate tissues, and significantly correlated with clinicopathological characters. Survival analysis indicated that CapG could be an independent prognostic factor in PCa. Moreover, CapG depletion significantly affected cellular proliferation and apoptosis by regulating Caspase 6/Caspase 9/Bcl-2/p-Akt/Akt signaling pathway.

CONCLUSION

CapG, as a potential biomarker in PCa, is associated with patient prognosis, cellular apoptosis and proliferation.

Tea polyphenol decreased growth and invasion in human ovarian cancer cells

Tea polyphenols (TP) are functional substances present in tea, which is one of the most promising preventive agents for cancer. This study was carried out to analyze the effects of TP on the ovarian cancer cells and possible mechanisms involved. TP led to inhibition of cell growth in a time- and dose-dependent manner, and promoted entry into the apoptosis-phase of the cell cycle. TP also decreased the invasion of ovarian cancer cells in vitro. In addition, TP treatment upregulated the mRNA expressions rate of Bax/Bcl-2 and downregulated Cyclin D and MMP2 mRNA expressions. Taken together, our data highlight that TP could be a potential therapeutic strategy for ovarian cancer. These findings also suggested that oncogens are involved in the anti-cancer effects of TP.

Liposome-mediated transfection of wild-type P53 DNA into human prostate cancer cells is improved by low-frequency ultrasound combined with microbubbles

Prostate cancer is a common type of cancer in elderly men. The aim of the present study was to evaluate the effects of ultrasound exposure in combination with SonoVue microbubbles on liposome-mediated transfection of wild-type P53 genes into human prostate cancer cells. PC-3 human prostate cancer cells were exposed to ultrasound; duty cycle was controlled at 20% (2 sec on, 8 sec off) for 5 min with and without SonoVue microbubble echo-contrast agent using a digital sonifier (frequency, 21 kHz; intensity, 46 mW/cm²). The cells were divided into eight groups, as follows: Group A (SonoVue + wild-type P53), group B (ultrasound + wild-type P53), group C (SonoVue + ultrasound + wild-type P53), group D (liposome + wild-type P53), group E (liposome + SonoVue + wild-type P53), group F (liposome + wild-type P53 + ultrasound), group G (liposome + wild-type P53 + ultrasound + SonoVue) and the control group (wild-type P53). Following treatment, a hemocytometer was used to measure cell lysis, reverse transcription-quantitative polymerase chain reaction and western blotting were performed to detect P53 gene transfection efficiency, Cell Counting Kit-8 was employed to reveal cell proliferation and Annexin V/propidium iodide staining was used to determine cell apoptosis. Cell lysis was minimal in each group. Wild-type P53 gene and protein expression were significantly increased in the PC-3 cells in group G compared with the control and all other groups (P<0.01). Cell proliferation was significantly suppressed in group G compared with the control group and all other groups (P<0.01). Cell apoptosis levels in group G were significantly improved compared with the control group and all other groups (P<0.01). Thus, the results of the present study indicate that the use of low-frequency and low-energy ultrasound in combination with SonoVue microbubbles may be a potent physical method for increasing liposome gene delivery efficiency.

Mangiferin blocks proliferation and induces apoptosis of breast cancer cells via suppression of the mevalonate pathway and by proteasome inhibition

Mangiferin is a natural xanthone glycoside with therapeutic potential.

HAX-1 inhibits apoptosis in prostate cancer through the suppression of caspase-9 activation

HS1 associated protein X-1 (HAX-1), a substrate of Src family tyrosine kinases, plays a critical role in cell apoptosis. However, its functions in prostate cancer remains unclear. The present study explored the role and mechanism of HAX-1 in cancer cell apoptosis. The mRNA and protein levels of HAX-1 in the prostate cancer cell lines PC-3, VCaP and DU145 were assessed. Cell proliferation, apoptosis and caspase-9 activities were assessed in DU145 after HAX-1 siRNA treatment. The mRNA and protein levels of HAX-1 in prostate cancer cell lines PC-3, VCaP and DU145 were significantly higher than those in the primary prostate epithelial cells, and DU145 possess the highest mRNA and protein levels compared to PC-3 and VCaP. When HAX-1 was knocked down in DU145, cell proliferation was significantly decreased, accompanied by a decrease in Ki67 protein expression. Compared with the control and control siRNA groups, HAX-1 siRNA promoted cell apoptosis and caspase-9 activation in DU145. Furthermore, prostate cancer cells co-transfected with HAX-1 and caspase-9 promoted viability and reduced apoptosis. In contract, co-transfection of caspase-9 and HAX-1 siRNA suppressed the cell viability and enhanced apoptosis. In summary, the present study demonstrated that HAX-1 inhibits cell apoptosis through caspase-9 inactivation.

Ovarian Cancer HO-8910 Cell Apoptosis Induced by Crocin in vitro

The effect and mechanism of ovarian cancer HO-8910 cell apoptosis induced by crocin. MTT assay was performed to detect the inhibitory action of crocin on the proliferation of HO-8910 cells. Flow cytometry was used to test the cell cycle distribution and apoptosis rate of ovarian cancer HO-8910 cells. Western blot analysis was utilized to measure the levels of apoptotic proteins such as p53, Fas/APO-1, and Caspase-3. MTT analysis revealed that crocin significantly inhibited the growth of HO-8910 cells. Additionally, flow cytometry illustrated that crocin raised the proportion of HO-8910 cells in the G0/G1 phase and increased their apoptosis rate. Furthermore, Western blot analysis revealed that crocin up-regulated the expression of p53, Fas/APO-1, and Caspase-3. The results of this study showed that crocin can significantly inhibit the growth of HO-8910 cells and arrest them in the G0/G1 phase. Crocin can also promote ovarian cancer HO-8910 cell apoptosis, most likely by increasing p53 and Fas/APO-1 expression, and then activating the apoptotic pathway regulated by Caspase-3.

Tumour suppressor HLJ1: A potential diagnostic, preventive and therapeutic target in non-small cell lung cancer

Lung cancer is the leading cause of cancer-related mortality throughout the world. Non-small cell lung cancer (NSCLC) accounts for 85% of all diagnosed lung cancers. Despite considerable progress in the diagnosis and treatment of the disease, the overall 5-year survival rate of NSCLC patients remains lower than 15%. The most common causes of death in lung cancer patients are treatment failure and metastasis. Therefore, developing novel strategies that target both tumour growth and metastasis is an important and urgent mission for the next generation of anticancer therapy research. Heat shock proteins (HSPs), which are involved in the fundamental defence mechanism for maintaining cellular viability, are markedly activated during environmental or pathogenic stress. HSPs facilitate rapid cell division, metastasis, and the evasion of apoptosis in cancer development. These proteins are essential players in the development of cancer and are prime therapeutic targets. In this review, we focus on the current understanding of the molecular mechanisms responsible for HLJ1’s role in lung cancer carcinogenesis and progression. HLJ1, a member of the human HSP 40 family, has been characterised as a tumour suppressor. Research studies have also reported that HLJ1 shows promising dual anticancer effects, inhibiting both tumour growth and metastasis in NSCLC. The accumulated evidence suggests that HLJ1 is a potential biomarker and treatment target for NSCLC.

Apigenin induces apoptosis by targeting inhibitor of apoptosis proteins and Ku70-Bax interaction in prostate cancer

Dysfunction of the apoptotic pathway in prostate cancer cells confers apoptosis resistance towards various therapies. A novel strategy to overcome resistance is to directly target the apoptotic pathway in cancer cells. Apigenin, an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms which are not fully explored. In the present study we provide novel insight into the mechanisms of apoptosis induction by apigenin. Treatment of androgen-refractory human prostate cancer PC-3 and DU145 cells with apigenin resulted in dose-dependent suppression of XIAP, c-IAP1, c-IAP2 and survivin protein levels. Apigenin treatment resulted in significant decrease in cell viability and apoptosis induction with the increase of cytochrome C in time-dependent manner. These effects of apigenin were accompanied by decrease in Bcl-xL and Bcl-2 and increase in the active form of Bax protein. The apigenin-mediated increase in Bax was due to dissociation of Bax from Ku70 which is essential for apoptotic activity of Bax. Apigenin treatment resulted in the inhibition of class I histone deacetylases and HDAC1 protein expression, thereby increasing the acetylation of Ku70 and the dissociation of Bax resulting in apoptosis of cancer cells. Furthermore, apigenin significantly reduced HDAC1 occupancy at the XIAP promoter, suggesting that histone deacetylation might be critical for XIAP downregulation. These results suggest that apigenin targets inhibitor of apoptosis proteins and Ku70-Bax interaction in the induction of apoptosis in prostate cancer cells and in athymic nude mouse xenograft model endorsing its in vivo efficacy.

Ellagic acid inhibits proliferation and induced apoptosis via the Akt signaling pathway in HCT-15 colon adenocarcinoma cells

Chemoprevention is regarded as one of the most promising and realistic approaches in the prevention of human cancer. Ellagic acid (EA) has been known for its chemopreventive activity against various cancers and numerous investigations have shown its apoptotic activity both in vivo and in vitro. The present study was focused to elucidate the anticancerous effect and the mode of action of EA against HCT-15 colon adenocarcinoma cells. Cell viability was assessed using trypan blue assay at different concentrations. EA also promoted cell cycle arrest substantially at G2/M phase in HCT-15 cells. The activities of alkaline phosphatase and lactate dehydrogenase were decreased upon EA treatment, which shows the antiproliferative and the cytotoxic effects, respectively. The production of reactive oxygen intermediates, which were examined by 2,7-dichlorodihydrofluorescein diacetate (H2DCF-DA), increased with time, after treatment with EA. In further studies, EA inhibited proliferation-associated markers proliferating cell nuclear antigen and cyclin D1. The induction of apoptosis was accompanied by a strong inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt pathway by EA. The expression of PI3K and pAkt was down-regulated in EA-treated cells, compared to normal cells. Further, EA promoted the expression of Bax, caspase-3, and cytochrome c, and suppression of Bcl-2 activity in HCT-15 cells that was determined by western blot analysis. Increased annexin V apoptotic cells and DNA fragmentation also accompanied EA-induced apoptosis. In conclusion, EA increased the production of ROS, decreased cell proliferation, and induced apoptosis in HCT-15 cells, and thus can be used as an agent against colon cancer.

Epigenetic effects of green tea polyphenols in cancer

Epigenetics describes heritable alterations of gene expression and chromatin organization without changes in DNA sequence. Both hypermethylation and hypomethylation of DNA can affect gene expression and the multistep process of carcinogenesis. Epigenetic changes are reversible and may be targeted by dietary interventions. Bioactive compounds from green tea (GT) such as (-)-epigallocatechin gallate have been shown to alter DNA methyltransferase activity in studies of esophageal, oral, skin, Tregs, lung, breast and prostate cancer cells, which may contribute to the chemopreventive effect of GT. Three out of four mouse model studies have confirmed the inhibitory effect of (-)-epigallocatechin gallate on DNA methylation. A human study demonstrated that decreased methylation of CDX2 and BMP-2 in gastric carcinoma was associated with higher GT consumption. It is the goal of this review to summarize our current knowledge of the potential of GT to alter epigenetic processes, which may be useful in chemoprevention.

miR-135b contributes to the radioresistance by targeting GSK3β in human glioblastoma multiforme cells

Radioresistance remains a major challenge in the treatment of glioblastoma multiforme (GBM). Recent data strongly suggests the important role of miRNAs in cancer progression and therapeutic response. Here, we have established a radioresistant human GBM cell line U87R derived from parental U87 and found miR-135b expression was upregulated in U87R cells. miR-135b knockdown reversed radioresistance of U87R cells, and miR-135b overexpression enhanced radioresistance of U87 cells. Mechanically, bioinformatics analysis combined with experimental analysis demonstrated GSK3β (Glycogen synthase kinase 3 beta) was a novel direct target of miR-135b. Moreover, GSK3β protein expression was downregulated in U87R cells and restored expression of GSK3β increased radiosensitivity of U87R cells. In addition, clinical data indicated that the expression of miR-135b or GSK3β was significantly association with IR resistance of GBM samples. Our findings suggest miR-135b is involved in the radioresistance of human GBM cells and miR-135b-GSK3β axis may be a novel candidate for developing rational therapeutic strategies for human GBM treatment.

Role of Bax/Bcl-2 family members in green tea polyphenol induced necroptosis of p53-deficient Hep3B cells

Green tea polyphenol (GTP) is one of the most promising chemopreventive agent for cancer; it can inhibit cancer cell proliferation and induce apoptosis through p53-dependent cell signaling pathways. Unfortunately, many tumor cells lack the functional p53, and little is known about the effect of GTP on the p53-deficient/mutant cancer cells. To understand the p53-independent mechanisms in GTP-treated p53-dificient/mutant cancer cells, we have now examined GTP-induced cytotoxicity in human hepatoma Hep3B cells (p53-deficient). The results showed that GTP could induce Bax and Bak activation, cytochrome c release, caspase activation, and necroptosis of Hep3B cells. Bax and Bak, two key molecules of mitochondrial permeability transition pore (MPTP), were interdependently activated by GTP, with translocation and homo-oligomerization on the mitochondria. Bax and Bak induce cytochrome c release. Importantly, cytochrome c release and necroptosis were diminished in Hep3B cells (Bax(-/-)) and Hep3B cells (Bak(-/-)). Furthermore, overexpression of Bcl-2 could ameliorate GTP-induced cytochrome c release and necroptosis. Together, the findings suggested that GTP-induced necroptosis was modulated by the p53-independent pathway, which was related to the translocation of Bax and Bak to mitochondria, release of cytochrome c, and activation of caspases.

Tea polyphenols induced apoptosis of breast cancer cells by suppressing the expression of Survivin

To study the mechanism of tea polyphenols (TP)-induced apoptosis of breast cancer cells. Proliferation of MCF-7 and SK-BR-3 cells was evaluated by MTT assays. Cellular ultrastructure was examined by electron microscopy. Apoptosis was detected by TUNEL. PCNA、 Cyclin D1、 Cyclin E and Survivin expression was measured by Western blot. Cell proliferation was significantly inhibited by TP. Spindle and round cells were loosely distributed with increased particles after TP treatment. Increased cell size, frequent nuclear atypia and a collapse of apoptosis were observed. The nucleus was pushed towards one side, while the cytoplasm was rich in free ribosome. The membrane of mitochondria was thickening, and the cell apoptotic body was observed. TP treated cells experienced significantly enhanced apoptosis compared with 5-Fu treated or control groups. The expression of survivin was downregulated by TP. To conclude, TP can inhibit cell growth and induce apoptosis through downregulating the expression of survivin in breast cancer.

²¹³Bi-anti-EGFR radioimmunoconjugates and X-ray irradiation trigger different cell death pathways in squamous cell carcinoma cells

INTRODUCTION

Treatment of patients with squamous cell carcinoma of head and neck is hampered by resistance of tumor cells to irradiation. Additional therapies enhancing the effect of X-ray irradiation may be beneficial. Antibodies targeting EGFR have been shown to improve the efficacy of radiation therapy. Therefore, we analyzed cytotoxicity of (213)Bi-anti-EGFR immunoconjugates in combination with X-ray irradiation.

METHODS

The monoclonal anti-EGFR antibody matuzumab was coupled to CHX-A"-DTPA forming stable complexes with (213)Bi. Cytotoxicity of X-ray radiation, of treatment with (213)Bi-anti-EGFR monoclonal antibodies (MAb) or of a combined treatment regimen was assayed using cell proliferation and colony formation assays in UD-SCC5 cells. Key proteins of cell-cycle arrest and cell death were examined by Western blot analysis. Cell cycle analysis was performed by flow cytometry. DNA double-strand breaks were detected via γH2AX and quantified using Definiens™ software.

RESULTS

Irradiation with X-rays or treatment with (213)Bi-anti-EGFR-MAb resulted in median lethal dose (LD50) values of 12 Gy or 130 kBq/mL, respectively. Treatment with 37 kBq/mL of (213)Bi-anti-EGFR-MAb or 2 Gy of X-rays had only little effect on colony formation of UD-SCC5 cells. In contrast, a combined treatment regimen (37 kBq/mL plus 2 Gy) significantly decreased colony formation and enhanced the formation of DNA double-strand breaks. As revealed by flow cytometry, radiation treatments caused accumulation of cells in the G0/G1 phase. Both treatment with (213)Bi-anti-EGFR immunoconjugates and application of the combined treatment regimen triggered activation of genes of signaling pathways involved in cell-cycle arrest and induction of apoptosis like p21/Waf, GADD45, Puma and Bax, which were only marginally modulated by X-ray irradiation of cells.

CONCLUSIONS

(213)Bi-anti-EGFR-MAb enhances cytotoxicity of X-ray irradiation in UD-SCC5 cells most probably due to effective induction of DNA double-strand breaks. Induction of genes involved in cell-cycle arrest and cell death is almost exclusively due to (213)Bi-anti-EGFR-MAb and seems to be independent of p53 function.