Prevalence, antimicrobial resistance, and enterotoxin gene profiles of Staphylococcus aureus isolated from mobile phones of the food vendors in Phayao province, Thailand.

BACKGROUND: Mobile phones are widely used and may cause bacterial pathogens to spread among various professionals. Staphylococcus aureus from the mobile phones can contaminate the hands of food vendors and food during the cooking or packaging process. This research aimed to determine the prevalence, enterotoxin genes, and antimicrobial resistance (AMR) profiles of S. aureus contaminating the vendors' mobile phones. METHODS: In this study, 266 mobile phone samples were randomly collected from food vendors selling food on walking streets (n = 139) and in food centers (n = 127) in Phayao province. All samples were identified as S. aureus by the conventional culture method and confirmed species-specific gene by polymerase chain reaction (PCR). Then, all identified S. aureus isolates were tested for antimicrobial susceptibility by broth microdilution method and for the presence of staphylococcal enterotoxin (SE) genes by PCR. RESULTS: The results showed that 12.8% of the mobile phones collected were contaminated with S. aureus. Of 49 S. aureus isolates obtained, 30 (61.2%) were positive for SE genes. The most common SE gene was sea followed by sec, seb, sem, seq, and sel. Moreover, S. aureus was most frequently resistant to penicillin, followed by chloramphenicol and tetracycline, erythromycin, clindamycin, and gentamicin. Methicillin-resistant S. aureus (MRSA), vancomycin-resistant S. aureus (VRSA), and multidrug-resistant (MDR) strains were also detected. CONCLUSIONS: This study showed that mobile phones were an intermediate surface for the transmission of S. aureus, including MDR variants. It indicates that hand hygiene and the decontamination of mobile phones are essential to prevent cross-contamination of S. aureus in food settings.

Anti-Influenza with Green Tea Catechins: A Systematic Review and Meta-Analysis.

Influenza is one of the most serious respiratory viral infections worldwide. Although several studies have reported that green tea catechins (GTCs) might prevent influenza virus infection, this remains controversial. We performed a systematic review and meta-analysis of eight studies with 5,048 participants that examined the effect of GTC administration on influenza prevention. In a random-effects meta-analysis of five RCTs, 884 participants treated with GTCs showed statistically significant effects on the prevention of influenza infection compared to the control group (risk ratio (RR) 0.67, 95%CIs 0.51-0.89, P = 0.005) without evidence of heterogeneity (I2= 0%, P = 0.629). Similarly, in three cohort studies with 2,223 participants treated with GTCs, there were also statistically significant effects (RR 0.52, 95%CIs 0.35-0.77, P = 0.001) with very low evidence of heterogeneity (I2 = 3%, P = 0.358). Additionally, the overall effect in the subgroup analysis of gargling and orally ingested items (taking capsules and drinking) showed a pooled RR of 0.62 (95% CIs 0.49-0.77, P = 0.003) without heterogeneity (I2= 0%, P = 0.554). There were no obvious publication biases (Egger's test (P = 0.138) and Begg's test (P = 0.103)). Our analysis suggests that green tea consumption is effective in the prophylaxis of influenza infections. To confirm the findings before implementation, longitudinal clinical trials with specific doses of green tea consumption are warranted.

Stiffening of Cancer Cell Membranes Is a Key Biophysical Mechanism of Primary and Tertiary Cancer Prevention with Green Tea Polyphenols.

Over the past 30 years, research of green tea polyphenols, especially (-)-epigallocatechin gallate (EGCG), has revealed that consumption of green tea is a practical and effective primary cancer prevention method for the general population. More recently, we believe that green tea polyphenols are beneficial for tertiary cancer prevention using green tea alone or combined with anticancer drugs because EGCG has the potential to inhibit metastatic progression and stemness, and enhance antitumor immunity. In an effort to identify a common underlying mechanism responsible for EGCG's multifunctional effects on various molecular targets, we studied the biophysical effects of EGCG on cell stiffness using atomic force microscopy. We found that EGCG acts to stiffen the membranes of cancer cells, leading to inhibition of signaling pathways of various receptors. Stiffening of membranes with EGCG inhibited AXL receptor tyrosine kinase, a stimulator of cell softening, motility and stemness, and expression of programmed cell death-ligand 1. This review covers the following: i) primary cancer prevention using EGCG or green tea, ii) tertiary cancer prevention by combining EGCG and anticancer drugs, iii) inhibition of metastasis with EGCG by stiffening the cell membrane, iv) inhibition of AXL receptor tyrosine kinase, a stimulator of cell softening and motility, with EGCG, v) inhibition of stemness properties with EGCG, and vi) EGCG as an alternative chemical immune checkpoint inhibitor. Development of new drugs that enhance stiffening of cancer cell membranes may be an effective strategy for tertiary cancer prevention and treatment.

Green Tea Catechin Is an Alternative Immune Checkpoint Inhibitor that Inhibits PD-L1 Expression and Lung Tumor Growth.

The anticancer activity of immune checkpoint inhibitors is attracting attention in various clinical sites. Since green tea catechin has cancer-preventive activity in humans, whether green tea catechin supports the role of immune checkpoint inhibitors was studied. We here report that (-)-epigallocatechin gallate (EGCG) inhibited programmed cell death ligand 1 (PD-L1) expression in non⁻small-cell lung cancer cells, induced by both interferon (IFN)-γ and epidermal growth factor (EGF). The mRNA and protein levels of IFN-γ⁻induced PD-L1 were reduced 40⁻80% after pretreatment with EGCG and green tea extract (GTE) in A549 cells, via inhibition of JAK2/STAT1 signaling. Similarly, EGF-induced PD-L1 expression was reduced about 37⁻50% in EGCG-pretreated Lu99 cells through inhibition of EGF receptor/Akt signaling. Furthermore, 0.3% GTE in drinking water reduced the average number of tumors per mouse from 4.1 ± 0.5 to 2.6 ± 0.4 and the percentage of PD-L1 positive cells from 9.6% to 2.9%, a decrease of 70%, in lung tumors of A/J mice given a single intraperitoneal injection of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In co-culture experiments using F10-OVA melanoma cells and tumor-specific CD3+ T cells, EGCG reduced PD-L1 mRNA expression about 30% in F10-OVA cells and restored interleukin-2 mRNA expression in tumor-specific CD3+ T cells. The results show that green tea catechin is an immune checkpoint inhibitor.

Antispasmodic Activity of Light-Roasted Coffee Extract and Its Potential Use in Gastrointestinal Motility Disorders.

Antispasmodic agents are crucial in managing gastrointestinal motility disorders by modulating muscle contractions and reducing symptoms like cramping and diarrhea. This study investigated the antispasmodic potential of different coffee bean extracts, including light coffee (LC), medium coffee (MC), and dark coffee (DC), on ileum contractions induced by potassium chloride (KCl), and elucidated their mechanisms of action using in vitro isolated tissue techniques. The results demonstrated that all coffee extracts reduced spontaneous contractions of rat ileum tissue in a dose-dependent manner. Among these, LC showed the most significant reduction in ileum contractions, particularly at higher concentrations. The key findings reveal that LC at 5 mg/mL significantly reduced CaCl2-induced contractions in isolated rat ileum tissue, indicating that LC may inhibit calcium influx or interfere with calcium signaling pathways. The presence of nifedipine, propranolol, and N-nitro-L-arginine methyl ester (L-NAME) have been confirmed in their involvement; they block calcium influx and calcium channels and activate ß-adrenergic pathways as part of LC's mechanism of action. The presence of their active compounds, particularly chlorogenic acid and caffeine, likely contributes to the observed antispasmodic effects. These findings suggest that LC exerts its antispasmodic effects by targeting key mechanisms involved in muscle spasms and intestinal motility, providing a potential for managing such conditions.

Suppressive Effect of Coffee Leaves on Lipid Digestion and Absorption In Vitro.

BACKGROUND: Coffee leaves are a major source of bioactive components and are used as ethnomedicine. However, despite their traditional medicinal use, information about their effects on antihyperlipidemia remains limited. METHODS: The aims of this study were to evaluate the main components of leaf extracts from Arabica and Robusta coffees and to examine the potential of these coffee leaves in reducing lipid digestion and absorption in vitro. RESULTS: Coffee leaf extracts from Arabica coffee contain a high amount of caffeine, whereas extracts from Robusta coffee contain high amounts of chlorogenic acid (CGA) and caffeine. Additionally, leaf extracts from Arabica and Robusta coffee demonstrated the inhibition of pancreatic lipase, decreased micellar cholesterol solubility, and reduced bile acid binding. Furthermore, these extracts resulted in a reduction in cholesterol uptake in Caco-2 cells. Molecular docking experiments supported this discovery, showing CGA and caffeine binding to Niemann-Pick C1-like 1 (NPC1L1), a key protein in cholesterol absorption. The results indicated that CGA and caffeine can competitively bind to NPC1L1 at the cholesterol binding pocket, reducing its cholesterol binding rate. These findings suggest that coffee leaves might help suppress lipid absorption and digestion, highlighting their potential use in preventing and treating hyperlipidemia.

Development of Biocellulose Sheet Incorporating Aloe vera Gel Extract for Diabetic Wound Healing.

In this study, a biocellulose (BC) sheet containing Aloe vera gel extract (AE) was developed for application in healing chronic wounds, such as diabetic wounds. The BC sheet was produced by Acetobacter xylinum and then lyophilized to obtain dried sheets. A. vera gel was extracted by precipitation in 35% ammonium sulfate, lyophilized, dried, and incorporated into the BC sheet. The protein content of the AE was 12.32 ± 3.4% w/w, with a molecular weight of ∼20 kDa. The release of TNF-α from lipopolysaccharide-induced RAW264.7 cells was reduced by treatment with AE in a dose-dependent manner. The physicochemical and biological properties of the developed sheet were investigated. Morphological examination of the BC/AE sheet using scanning electron microscopy revealed the 3D construction of nanofibrils, which showed high porosity. The BC/AE sheet exhibited water absorption at 74%, and the release of proteins in the AE reached 97.23% at 4 h. The BC sheet incorporated with proteins in the AE at 283.78 ± 7.7 µg/cm2 can promote the wound healing in streptozotocin-induced diabetic rats. The recovering skin in diabetic wounds treated with the BC/AE sheet exhibited a normal cell arrangement without fibrosis, as revealed by histological staining. The research findings indicate that the BC/AE sheet has potential for applications in wound dressings.

Restoring Ampicillin Sensitivity in Multidrug-Resistant Escherichia coli Following Treatment in Combination with Coffee Pulp Extracts.

Escherichia coli, particularly multidrug-resistant (MDR) strains, is a serious cause of healthcare-associated infections. Development of novel antimicrobial agents or restoration of drug efficiency is required to treat MDR bacteria, and the use of natural products to solve this problem is promising. We investigated the antimicrobial activity of dried green coffee (DGC) beans, coffee pulp (CP), and arabica leaf (AL) crude extracts against 28 isolated MDR E. coli strains and restoration of ampicillin (AMP) efficiency with a combination test. DGC, CP, and AL extracts were effective against all 28 strains, with a minimum inhibitory concentration (MIC) of 12.5-50 mg/ml and minimum bactericidal concentration of 25-100 mg/ml. The CP-AMP combination was more effective than CP or AMP alone, with a fractional inhibitory concentration index value of 0.01. In the combination, the MIC of CP was 0.2 mg/ml (compared to 25 mg/ml of CP alone) and that of AMP was 0.1 mg/ml (compared to 50 mg/ml of AMP alone), or a 125-fold and 500-fold reduction, respectively, against 13-drug resistant MDR E. coli strains. Time-kill kinetics showed that the bactericidal effect of the CP-AMP combination occurred within 3 h through disruption of membrane permeability and biofilm eradication, as verified by scanning electron microscopy. This is the first report indicating that CP-AMP combination therapy could be employed to treat MDR E. coli by repurposing AMP.

Anticancer and Antimutagenic Properties of Pogonatherum paniceum on Colorectal Cancer Cells.

Background: Pogonatherum paniceum (P. paniceum) (Lam.) Hack. plays an important role in detoxification. However, its anticancer activity has not yet been elucidated. The aim of our study was to examine the suppressive proliferation, anti-migration and mutagenic/antimutagenic properties of P. paniceum. Moreover, we set out to determine the cellular mechanism underlying its antiproliferation. Methods: To investigate P. paniceum's anticancer ability, HCT116 and HT29 cell lines were treated with a water extract containing P. paniceum, and then the cell viability was examined using the trypan blue exclusion method which were compared to HEK293 (non-cancerous cells). The anticancer effects were investigated by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) and colony formation assay. Apoptosis induction, cell cycle distribution, and migration abilities were assessed by cell death detection enzyme-linked immunoassay (ELISA), flow cytometry, and wound healing assay. Finally, the mutagenicity and antimutagenicity were evaluated using the micronucleus assay. Results: Treatment with P. paniceum caused a loss of cell viability in HCT116 and HT29 cells (not found in HEK293), which had an IC50 (half-maximal inhibitory concentration) of 1,156.2 and 1,207.0 µg/mL, respectively. We found that P. paniceum significantly inhibited the proliferative function of HCT116 and HT29 cells. To find the mechanism that exerts a suppressive proliferation effect on P. paniceum, we determined the DNA fragmentation and cell cycle distribution. We also found that P. paniceum treatment increased apoptosis and arrested of the cell cycle at G0/G1 remarkably when compared with the control group. Moreover, P. paniceum could decrease the migration of HCT116 and HT29 cancer cells. Finally, the treatment of P. paniceum did not induce micronucleus formation but did decrease the micronucleus frequency against mutagen-mitomycin C. Conclusions: P. paniceum did not possess any toxicity (cytotoxic and mutagenic) but has the potential for anticancer activity against human colorectal cells by increasing apoptosis, which leads to the suppression of cell proliferation. P. paniceum also inhibits cell migration and exerts antimutagenicity, thereby suggesting that P. paniceum might be useful for colorectal cancer treatment.

Dinactin: A New Antitumor Antibiotic with Cell Cycle Progression and Cancer Stemness Inhibiting Activities in Lung Cancer.

Lung cancer, especially non-small cell lung cancer (NSCLC), is one of the most complex diseases, despite the existence of effective treatments such as chemotherapy and immunotherapy. Since cancer stem cells (CSCs) are responsible for chemo- and radio-resistance, metastasis, and cancer recurrence, finding new therapeutic targets for CSCs is critical. Dinactin is a natural secondary metabolite produced by microorganisms. Recently, dinactin has been revealed as a promising antitumor antibiotic via various mechanisms. However, the evidence relating to cell cycle progression regulation is constrained, and effects on cancer stemness have not been elucidated. Therefore, the aim of this study is to evaluate the new function of dinactin in anti-NSCLC proliferation, focusing on cell cycle progression and cancer stemness properties in Lu99 and A549 cells. Flow cytometry and immunoblotting analyses revealed that 0.1-1 µM of dinactin suppresses cell growth through induction of the G0/G1 phase associated with down-regulation of cyclins A, B, and D3, and cdk2 protein expression. The tumor-sphere forming capacity was used to assess the effect of dinactin on the cancer stemness potential in NSCLC cells. At a concentration of 1 nM, dinactin reduced both the number and size of the tumor-spheres. The quantitative RT-PCR analyses indicated that dinactin suppressed sphere formation by significantly reducing expression of CSC markers (i.e., ALDH1A1, Nanog, Oct4, and Sox2) in Lu99 cells. Consequently, dinactin could be a promising strategy for NSCLC therapy targeting CSCs.

Antimicrobial Activity of the Green Tea Polyphenol (-)-Epigallocatechin-3-Gallate (EGCG) against Clinical Isolates of Multidrug-Resistant Vibrio cholerae.

The spread of multidrug-resistant (MDR) Vibrio cholerae necessitates the development of novel prevention and treatment strategies. This study aims to evaluate the in vitro antibacterial activity of green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) against MDR V. cholerae. First, MIC and MBC values were evaluated by broth microdilution techniques against 45 V. cholerae strains. The checkerboard assay was then used to determine the synergistic effect of EGCG and tetracycline. The pharmaceutical mode of action of EGCG was clarified by time-killing kinetics and membrane disruption assay. Our results revealed that all of the 45 clinical isolates were susceptible to EGCG, with MIC and MBC values in the range of 62.5-250 µg/mL and 125-500 µg/mL, respectively. Furthermore, the combination of EGCG and tetracycline was greater than either treatment alone, with a fractional inhibitory concentration index (FICI) of 0.009 and 0.018 in the O1 and O139 representative serotypes, respectively. Time-killing kinetics analysis suggested that EGCG had bactericidal activity for MDR V. cholerae after exposure to at least 62.5 µg/mL EGCG within 1 h. The mode of action of EGCG might be associated with membrane disrupting permeability, as confirmed by scanning electron microscopy. This is the first indication that EGCG is a viable anti-MDR V. cholerae treatment.

Potential Antimicrobial Properties of Coffee Beans and Coffee By-Products Against Drug-Resistant Vibrio cholerae.

Vibrio cholerae is the causative organism of the cholera epidemic, and it remains a serious global health problem, particularly the multidrug-resistant strain, despite the development of several generic drugs and vaccines over time. Natural products have long been exploited for the treatment of various diseases, and this study aimed to evaluate the in vitro antibacterial activity of coffee beans and coffee by-products against V. cholerae antimicrobial resistant strains. A total of 9 aqueous extracts were investigated, including light coffee (LC), medium coffee (MC), dark coffee (DC), dried green coffee (DGC), dried red coffee (DRC), fresh red coffee (FRC), Arabica leaf (AL), Robusta leaf (RL), and coffee pulp (CP). The influential coffee phytochemicals, i.e., chlorogenic acid (CGA), caffeic acid (CA), and caffeine, were determined using HPLC. The antibacterial properties were tested by agar well-diffusion techniques, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were further determined against 20 V. cholerae isolates. The results revealed that all tested strains were sensitive to coffee extracts, with MIC and MBC values in the range of 3.125-25.0 mg/mL and 12.5-50.0 mg/mL, respectively. With a MIC of 6.25 mg/mL, DGC, DRC, and CP appeared to be the most effective compounds against 65, 60, and 55% of clinical strains, respectively. The checkerboard assay revealed that the combination of coffee extract and tetracycline was greater than either treatment alone, with the fractional inhibitory concentration index (FICI) ranging from 0.005 to 0.258. It is important to note that CP had the lowest FICI (0.005) when combined with tetracycline at 60 ng/mL, which is the most effective dose against V. cholerae six-drug resistance strains (azithromycin, colistin, nalidixic acid, sulfamethoxazole, tetracycline, and trimethoprim), with a MIC of 47.5 µg/mL (MIC alone = 12.5 mg/mL). Time killing kinetics analysis suggested that CA might be the most effective treatment for drug-resistant V. cholerae as it reduced bacterial growth by 3 log10 CFU/mL at a concentration of 8 mg/mL within 1 h, via disrupting membrane permeability, as confirmed by scanning electron microscopy (SEM). This is the first report showing that coffee beans and coffee by-product extracts are an alternative for multidrug-resistant V. cholerae treatment.

(-)-Epigallocatechin gallate inhibits stemness and tumourigenicity stimulated by AXL receptor tyrosine kinase in human lung cancer cells.

Cancer stem cells (H1299-sdCSCs) were obtained from tumour spheres of H1299 human lung cancer cells. We studied low stiffness, a unique biophysical property of cancer cells, in H1299-sdCSCs and parental H1299. Atomic force microscopy revealed an average Young's modulus value of 1.52 kPa for H1299-sdCSCs, which showed low stiffness compared with that of H1299 cells, with a Young's modulus value of 2.24 kPa. (-)-Epigallocatechin gallate (EGCG) reversed the average Young's modulus value of H1299-sdCSCs to that of H1299 cells. EGCG treatment inhibited tumour sphere formation and ALDH1A1 and SNAI2 (Slug) expression. AXL receptor tyrosine kinase is highly expressed in H1299-sdCSCs and AXL knockdown with siAXLs significantly reduced tumour sphere formation and ALDH1A1 and SNAI2 (Slug) expression. An AXL-high population of H1299-sdCSCs was similarly reduced by treatment with EGCG and siAXLs. Transplantation of an AXL-high clone isolated from H1299 cells into SCID/Beige mice induced faster development of bigger tumour than bulk H1299 cells, whereas transplantation of the AXL-low clone yielded no tumours. Oral administration of EGCG and green tea extract (GTE) inhibited tumour growth in mice and reduced p-AXL, ALDH1A1, and SLUG in tumours. Thus, EGCG inhibits the stemness and tumourigenicity of human lung cancer cells by inhibiting AXL.

Cancer Prevention with Green Tea and Its Principal Constituent, EGCG: from Early Investigations to Current Focus on Human Cancer Stem Cells.

Cancer preventive activities of green tea and its main constituent, (-)-epigallocatechin gallate (EGCG) have been extensively studied by scientists all over the world. Since 1983, we have studied the cancer chemopreventive effects of EGCG as well as green tea extract and underlying molecular mechanisms. The first part of this review summarizes ground-breaking topics with EGCG and green tea extract: 1) Delayed cancer onset as revealed by a 10-year prospective cohort study, 2) Prevention of colorectal adenoma recurrence by a double-blind randomized clinical phase II trial, 3) Inhibition of metastasis of B16 melanoma cells to the lungs of mice, 4) Increase in the average value of Young's moduli, i.e., cell stiffness, for human lung cancer cell lines and inhibition of cell motility and 5) Synergistic enhancement of anticancer activity against human cancer cell lines with the combination of EGCG and anticancer compounds. In the second part, we became interested in cancer stem cells (CSCs). 1) Cancer stem cells in mouse skin carcinogenesis by way of introduction, after which we discuss two subjects from our review on human CSCs reported by other investigators gathered from a search of PubMed, 2) Expression of stemness markers of human CSCs compared with their parental cells, and 3) EGCG decreases or increases the expression of mRNA and protein in human CSCs. On this point, EGCG inhibited self-renewal and expression of pluripotency-maintaining transcription factors in human CSCs. Human CSCs are thus a target for cancer prevention and treatment with EGCG and green tea catechins.

Human cancer stem cells are a target for cancer prevention using (-)-epigallocatechin gallate.

PURPOSE: Our previous experiments show that the main constituent of green-tea catechins, (-)-epigallocatechin gallate (EGCG), completely prevents tumor promotion on mouse skin initiated with 7,12-dimethylbenz(a)anthracene followed by okadaic acid and that EGCG and green tea extract prevent cancer development in a wide range of target organs in rodents. Therefore, we focused our attention on human cancer stem cells (CSCs) as targets of cancer prevention and treatment with EGCG. METHODS: The numerous reports concerning anticancer activity of EGCG against human CSCs enriched from cancer cell lines were gathered from a search of PubMed, and we hope our review of the literatures will provide a broad selection for the effects of EGCG on various human CSCs. RESULTS: Based on our theoretical study, we discuss the findings as follows: (1) Compared with the parental cells, human CSCs express increased levels of the stemness markers Nanog, Oct4, Sox2, CD44, CD133, as well as the EMT markers, Twist, Snail, vimentin, and also aldehyde dehydrogenase. They showed decreased levels of E-cadherin and cyclin D1. (2) EGCG inhibits the transcription and translation of genes encoding stemness markers, indicating that EGCG generally inhibits the self-renewal of CSCs. (3) EGCG inhibits the expression of the epithelial-mesenchymal transition phenotypes of human CSCs. (4) The inhibition of EGCG of the stemness of CSCs was weaker compared with parental cells. (5) The weak inhibitory activity of EGCG increased synergistically in combination with anticancer drugs. CONCLUSIONS: Green tea prevents human cancer, and the combination of EGCG and anticancer drugs confers cancer treatment with tissue-agnostic efficacy.

Phorbol esters in seed oil of Jatropha curcas L. (saboodam in Thai) and their association with cancer prevention: from the initial investigation to the present topics.

PURPOSE: In 1988, we first reported the complete chemical structure of a new type of phorbol ester, abbreviated to DHPB, found in seed oil of Jatropha curcas L. (Saboodam in Thai) and its tumor-promoting activity on mouse skin. Although this seed oil contains toxic phorbol ester, it was planned to use it as a feasible renewable oil and the extracted seed cake as fertilizer. This utilization value opened a new science of Jatropha curcas. METHODS: The main experimental results are cited from our publications, and the relevant literature screened from journals and PubMed. RESULTS AND DISCUSSION: This paper begins with our original work on the structural elucidation of a new phorbol ester, 12-deoxy-16-hydroxyphorbol (DHPB): its tumor-promoting activity was compared with that of TPA. We think that it is timely to review the following research advances with Jatropha curcas, so numerous topics are classified as follows: (1) historical development of phorbol esters in seed oil; (2) toxicity of phorbol ester based on various bioassays; (3) degradation of phorbol ester; (4) a new pharmaceutical compound in seed; and (5) tumor promotion and progression with endogeneous tumor promoters in human carcinogenesis. The discovery of phorbol ester in seed oil raised awareness of the danger of public use of seed oil and seed cake in Thailand, and also indicated the necessity of discussing the concept of primary and tertiary cancer preventions. CONCLUSION: It is worthwhile to study the future benefits and cancer risks of globally distributed Jatropha curcas L.

Cell softening in malignant progression of human lung cancer cells by activation of receptor tyrosine kinase AXL.

To study the role of cell softening in malignant progression, Transwell assay and atomic force microscope were used to classify six human non-small cell lung cancer cell lines into two groups: a high motility-low stiffness (HMLS) group and a low motility-high stiffness (LMHS) group. We found a significant role of activity of the AXL receptor tyrosine kinase, which belongs to the TAM (Tyro3, AXL, Mer) family, in the stimulation of motility and cell softening. HMLS cells expressed higher AXL levels than LMHS cells and contained phosphorylated AXL. H1703 LMHS cells transfected with exogenous AXL exhibited increased motility and decreased stiffness, with low levels of actin stress fibre formation. Conversely, the AXL-specific inhibitor R428 and AXL-targeting siRNA reduced motility and increased stiffness in H1299 HMLS cells. Knockdown of AXL stimulated actin stress fibre formation, which inhibited tumour formation in a mouse xenograft model. The Ras/Rac inhibitor SCH 51344, which blocks disruption of actin stress fibres, exerted similar effects to AXL inactivation. We therefore propose that the Ras/Rac pathway operates downstream of AXL. Thus, AXL activation-induced cell softening promotes malignant progression in non-small cell lung cancer and represents a key biophysical property of cancer cells.

Down-regulation of histone deacetylase 4, -5 and -6 as a mechanism of synergistic enhancement of apoptosis in human lung cancer cells treated with the combination of a synthetic retinoid, Am80 and green tea catechin.

(-)-Epigallocatechin gallate (EGCG), a green tea catechin, acts as a synergist with various anticancer drugs, including retinoids. Am80 is a synthetic retinoid with a different structure from all-trans-retinoic acid: Am80 is now clinically utilized as a new drug for relapsed and intractable acute promyelocytic leukemia patients. Our experiments showed that the combination of EGCG and Am80 synergistically induced both apoptosis in human lung cancer cell line PC-9 and up-regulated expressions of growth arrest and DNA damage-inducible gene 153 (GADD153), death receptor 5, and p21waf1 genes in the cells. To understand the mechanisms of synergistic anticancer activity of the combination, we gave special attention to the lysine acetylation of proteins. Proteomic analysis using nanoLC-ESI-MS/MS revealed that PC-9 cells treated with the combination contained 331 acetylated proteins, while nontreated cells contained 553 acetylated proteins, and 59 acetylated proteins were found in both groups. Among them, the combination increased acetylated-p53 and acetylated-α-tubulin through reduction of histone deacetylase (HDAC) activity in cytosol fraction, although the levels of acetylation in histones H3 or H4 did not change, and the combination reduced protein levels of HDAC4, -5 and -6 by 20% to 80%. Moreover, we found that a specific inhibitor of HDAC4 and -5 strongly induced p21waf1 gene expression, and that of HDAC6 induced both GADD153 and p21waf1 gene expression, which resulted in apoptosis. All results demonstrate that EGCG in combination with Am80 changes levels of acetylation in nonhistone proteins via down-regulation of HDAC4, -5 and -6 and stimulates apoptotic induction.