Resina Draconis extract exerts anti-HCC effects through METTL3-m6A-Survivin axis.

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Herbal medicines have become an important treasure reservoir for anti-HCC drugs because of their high efficiency and low toxicity. Herein, we investigated whether a 75% ethanol extract from Resina Draconis (ERD) exhibited comprehensive anti-HCC effects both in vivo and in vitro. We revealed that ERD effectively inhibited proliferation and triggered apoptosis of HCC cells in a dose- and time-dependent maner, posing no apparent apoptotic toxicity to normal liver cells. Moreover, ERD significantly inhibited the migration, invasion and metastasis of HCC cells. Importantly, ERD treatment effectively inhibited the growth of xenograft HCC in nude mice with low toxicity and low side effects. Molecular mechanism analysis showed that ERD strongly reduced the expression of anti-apoptotic protein Survivin, ultimately leading to the cleavage activation of apoptosis executive proteins such as Caspase 3 and Poly (ADP-ribose) polymerase (PARP). Survivin gene silencing apparently sensitized the apoptotic effect induced by ERD. Further experiments revealed that ERD inhibited N6-methyladenosine (m6 A) modification in Survivin mRNA by downregulating Methyltransferase-like 3 (METTL3) expression and reducing the binding rate of METTL3 and Survivin mRNA. Together, our findings suggest that ERD can be severed as a novel anti-HCC natural product by targeting METTL3-m6 A-Survivin axis.

Two-color fluorescent proteins reporting survivin regulation in breast cancer cells for high throughput drug screening.

Reporter gene assay is widely used for high throughput drug screening and drug action mechanism evaluation. In this study, we developed a robust dual-fluorescent reporter assay to detect drugs repressing the transcription of survivin, a cancer biomarker from the inhibitor of apoptosis family, in breast cancer cells cultured in three-dimensional (3D) microbioreactors. Survivin is overexpressed in numerous malignancies but almost silent in normal tissue cells and is considered a lead target for cancer therapy. Breast cancer MCF-7 cells were engineered to express enhanced green fluorescent protein driven by a survivin promoter and red fluorescent protein driven by a cytomegalovirus promoter as internal control to detect changes in survivin expression in cells as affected by drugs. This 3D dual-fluorescent reporter assay was validated with YM155 and doxorubicin, which were known to downregulate survivin in cancer cells, and further evaluated with two widely used anticancer compounds, cisplatin, and epigallocatechin gallate, to evaluate their effects on survivin expression. The results showed that the 3D dual-fluorescent reporter assay was robust for high throughput screening of drugs targeting survivin in breast cancer cells.

Preclinical Investigation of Trifluoperazine as a Novel Therapeutic Agent for the Treatment of Pulmonary Arterial Hypertension.

Trifluoperazine (TFP), an antipsychotic drug approved by the Food and Drug Administration, has been show to exhibit anti-cancer effects. Pulmonary arterial hypertension (PAH) is a devastating disease characterized by a progressive obliteration of small pulmonary arteries (PAs) due to exaggerated proliferation and resistance to apoptosis of PA smooth muscle cells (PASMCs). However, the therapeutic potential of TFP for correcting the cancer-like phenotype of PAH-PASMCs and improving PAH in animal models remains unknown. PASMCs isolated from PAH patients were exposed to different concentrations of TFP before assessments of cell proliferation and apoptosis. The in vivo therapeutic potential of TFP was tested in two preclinical models with established PAH, namely the monocrotaline and sugen/hypoxia-induced rat models. Assessments of hemodynamics by right heart catheterization and histopathology were conducted. TFP showed strong anti-survival and anti-proliferative effects on cultured PAH-PASMCs. Exposure to TFP was associated with downregulation of AKT activity and nuclear translocation of forkhead box protein O3 (FOXO3). In both preclinical models, TFP significantly lowered the right ventricular systolic pressure and total pulmonary resistance and improved cardiac function. Consistently, TFP reduced the medial wall thickness of distal PAs. Overall, our data indicate that TFP could have beneficial effects in PAH and support the view that seeking new uses for old drugs may represent a fruitful approach.

Efficient Stable Cell Line Generation of Survivin as an In Vitro Model for Specific Functional Analysis in Apoptosis and Drug Screening.

Recognizing proteins that lead to a decreased efficiency of treatment in cancer cells constitutes a main goal for biomedical and biotechnological research and applications. Establishing recombinant cells that overexpress a gene of interest stably is important for treatment studies and drug/compound screening. Survivin is an anti-apoptotic protein which can be a potential candidate for regulating cell death and survival. To investigate the association between survivin increment and apoptosis rate, survivin-reconstituted HEK (HEK-S) cell was developed as in vitro model. RT-PCR and Western blot demonstrated that survivin was constitutively overexpressed in HEK-S cells. Both morphological observation and survival assay showed that HEK-S cells were significantly resistant to apoptotic stimuli. Survivin overexpression led to a decrease in caspase 3/7 activity, whereas YM155 led to a corresponding enhance of caspase activity. ROS level was decreased but ATP content increased in HEK-S cells. Also, HEK-S showed less red- fluorescence and reduced cell proliferation compared to HEK after stimulation. Resistance to laser irradiation was clearly visible as compared with control. Moreover, scratching analysis demonstrated the ability of survivin to cause neighboring cells to increase resistance to drug, whereas YM155 enhanced apoptotic rate and declined invasion in HEK-S cells.

Evaluation of antioxidant, anti-inflammatory and anticancer activities of diosgenin enriched Paris polyphylla rhizome extract of Indian Himalayan landraces.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional medicinal plants have gained attention as a potential therapeutic agent to combat cancer and inflammation. Diosgenin rich fresh extracts of Paris polyphylla rhizome from Indian Himalaya is traditionally used as wound healing, anti-bleeding, anti-inflammatory and anti-cancer agent by the folk healers. AIM OF THE STUDY: Present study was aimed to prepare two types of extracts from Paris polyphylla rhizome of Indian Himalayan landraces - 1. ethanolic extract of Paris polyphylla rhizome (EEPPR) and 2. Diosgenin enriched Paris polyphylla rhizome extract (DPPE), quantification of diosgenin content, and to evaluate their in vitro anti-oxidant, in vivo anti-inflammatory and in vitro cytotoxicity and anti-cancer activities of the DPPE. MATERIALS AND METHODS: Diosgenin content of EEPPR was quantified through GC-MS while diosgenin content of DPPE was quantified through HPTLC, and the diosgenin yield from EEPPR and DPPE were compared. In vitro antioxidant activities of DPPE were performed using DPPH, NOD, RP and SOD assay while in vivo anti-inflammatory activity of DPPE were evaluated in dextran induced hind paw edema in rats. In vitro cytotoxicity and anti-cancer activities of DPPE were evaluated in human breast cancer cell lines (MCF-7, MDA-MB-231), cervical cancer cell lines (HeLa) and Hep-2 cell lines. RESULTS: EEPPR obtained through cold extraction method using 70% ethanol showed maximum diosgenin content of 17.90% quantified through GC-MS while similar compounds pennogenin (3.29%), 7ß-Dehydrodiosgenin (1.90%), 7-Ketodiosgenin acetate (1.14%), and 7 ß-hydroxydiosgenin (0.55%) were detected in low concentration, and thus confirmed diosgenin as major and lead phytochemical. However, DPPE obtained through both cold and repeated hot extraction with the same solvent (70% ethanol) showed diosgenin content of 60.29% which is significantly higher (p < 0.001) than the diosgenin content in EEPPR. DPPE demonstrated significant in vitro antioxidant activities by dose-dependently quenched (p < 0.001) SOD free radicals by 76.66%, followed by DPPH (71.43%), NOD (67.35%), and RP (63.74%) at a max concentration of 2 µg/µl of ascorbic acid and test drugs with remarkable IC50 values (p < 0.01). Further, DPPE also showed potent anti-inflammatory activities by dose-dependently suppressed dextran induced paw edema in rats (p < 0.01) from 2 h to 4 h. DPPE suppressed the proliferation of MCF-7, MDA-MB-231, Hep-2 and HeLa cell lines. Maximum activity was observed in MCF-7 cells. The DPPE also induced apoptosis in MCF-7 cell lines as measured by AO/PI and DAPI staining, as well as DNA laddering, cell cycle analysis and phosphatidylserine externalization assay. The growth-inhibitory effect of DPPE on MCF-7 breast cancer cells was further confirmed from the colony-formation assay. DPPE upregulated expression of Bax and downregulated Bcl-2 and survivin mRNA transcripts. CONCLUSION: DPPE obtained through both cold and repeated hot extraction using ethanol showed significantly higher content of diosgenin than the diosgenin content detected in EEPPR. However, diosgenin yield of both the extracts (EEPPR & DPPE) clearly confirmed diosgenin as major and lead phytochemical of Paris polyphylla rhizome of Indian Himalayan landraces. Further, DPPE also demonstrated potent in vitro anti-oxidative and in vivo anti-inflammatory activities and showed in vitro cytotoxicity and significant anti-cancer (apoptosis) effects in MCF-7 breast cancer cells.

Involvement of mTOR/Survivin signaling pathway in TUA(2ß, 3ß, 23-trihydroxy-urs-12-ene-28-olic acid)-induced apoptosis in human gastric cancer cell line BGC823 cells.

ETHNO-PHARMACOLOGICAL RELEVANCE: A natural ursolic compound, 2ß,3ß,23-trihydroxy-urs-12-ene-28-olic acid (TUA) was isolated from the root of Actinidiafulvicoma Hance. (A.fulvicoma Radix), which is used as a traditional hebal medicine to cure innominate inflammation of unknown origin of the digestive tract in the She nationality. AIM OF THE STUDY: The aim of present study was to investigate the effects of TUA on gastric cancer and to clarify the potential mechanisms in human gastric cancer cell line BGC823 cells in vitro and in vivo. MATERIALS AND METHODS: Cell proliferation, apoptosis, cell cycle, autophagy were all measured by MTS assay, flow cytometry following exposure to TUA. The mRNA expressions of PI3K, AKT, mTOR, P70S6K, Survivin and the protein expressions of p-PI3K, p-AKT, p-mTOR, p-P70S6K, Survivin were determined by qRT-PCR and Western blotting analysis, respectively. In vivo antitumor activity of TUA was assessed in a xenograft model. RESULTS: In vitro studies showed that TUA significantly suppressed the viability of BGC823 cells in a concentration- and time-dependent manner but not GES-1 non-tumorigenic human gastric epithelial cells. TUA also significantly increased the apoptosis rate and the sub G2 population by cell cycle analysis in a concentration dependent manner. Exposure to TUA decreased PI3K, AKT, mTOR, P70S6K, Survivin mRNA, inhibited the phosphorylation of major receptors involved in autophagy and apoptosis, such as PI3K, AKT, mTOR and P70S6K, while reduced the expression of Survivin in BGC cells. In vivo studies showed that TUA decreased tumor volume and tumor weight and also down regulated the autophagy-related proteins expression. CONCLUSIONS: TUA occupies underlying antitumor effects, the potential mechanisms may involve the suppression of mTOR/Survivin pathways connected to autophagy and the activation of apoptotic pathways in gastric cancer cells.

Role of the Transcription Factor Yin Yang 1 and Its Selectively Identified Target Survivin in High-Grade B-Cells Non-Hodgkin Lymphomas: Potential Diagnostic and Therapeutic Targets.

B-cell non-Hodgkin lymphomas (B-NHLs) are often characterized by the development of resistance to chemotherapeutic drugs and/or relapse. During drug-induced apoptosis, Yin Yang 1 (YY1) transcription factor might modulate the expression of apoptotic regulators genes. The present study was aimed to: (1) examine the potential oncogenic role of YY1 in reversing drug resistance in B-NHLs; and (2) identify YY1 transcriptional target(s) that regulate the apoptotic pathway in B-NHLs. Predictive analyses coupled with database-deposited data suggested that YY1 binds the promoter of the BIRC5/survivin anti-apoptotic gene. Gene Expression Omnibus (GEO) analyses of several B-NHL repositories revealed a conserved positive correlation between YY1 and survivin, both highly expressed, especially in aggressive B-NHLs. Further validation experiments performed in Raji Burkitt's lymphomas cells, demonstrated that YY1 silencing was associated with survivin downregulation and sensitized the cells to apoptosis. Overall, our results revealed that: (1) YY1 and survivin are positively correlated and overexpressed in B-NHLs, especially in BLs; (2) YY1 strongly binds to the survivin promoter, hence survivin may be suggested as YY1 transcriptional target; (3) YY1 silencing sensitizes Raji cells to drug-induced apoptosis via downregulation of survivin; (4) both YY1 and survivin are potential diagnostic markers and therapeutic targets for the treatment of resistant/relapsed B-NHLs.

Epoxyazadiradione exhibit activities in head and neck squamous cell carcinoma by targeting multiple pathways.

The head and neck squamous cell carcinoma (HNSCC) constitute about 90% of all head and neck cancers. HNSCC falls in the top 10 cancers in men globally. Epoxyazadiradione (EPA) and Azadiradione (AZA) are the limonoids derived from the medicinal plant Azadirachta indica (popularly known as Neem). Whether or not the limonoids exhibit activities against HNSCC and the associated mechanism remains elusive. Herein, we demonstrate that EPA exhibits stronger activity in HNSCC in comparison to AZA. The limonoids obeyed the Lipinski's rule of 5. EPA exhibited activities in a variety of HNSCC lines like suppression of the proliferation and the induction of apoptosis. The limonoid suppressed the level of proteins associated with anti-apoptosis (survivin, Bcl-2, Bcl-xL), proliferation (cyclin D1), and invasion (MMP-9). Further, the expression of proapoptotic Bax and caspase-9 cleavage was induced by the limonoid. Exposure of EPA induced reactive oxygen species (ROS) generation in the FaDu cells. N-acetyl-L-cysteine (ROS scavenger) abrogated the down-regulation of tumorigenic proteins caused by EPA exposure. EPA induced NOX-5 while suppressing the expression of programmed death-ligand 1 (PD-L1). Further, hydrogen peroxide induced NF-κB-p65 nuclear translocation and EPA inhibited the translocation. Finally, EPA modulated the expression of lncRNAs in HNSCC lines. Overall, these results have shown that EPA exhibit activities against HNSCC by targeting multiple cancer related signalling molecules. Currently, we are evaluating the efficacy of this molecule in mice models.

Broussoflavonol B from Broussonetia kazinoki Siebold Exerts Anti-Pancreatic Cancer Activity through Downregulating FoxM1.

Pancreatic cancer has a high mortality rate due to poor rates of early diagnosis. One tumor suppressor gene in particular, p53, is frequently mutated in pancreatic cancer, and mutations in p53 can inactivate normal wild type p53 activity and increase expression of transcription factor forkhead box M1 (FoxM1). Overexpression of FoxM1 accelerates cellular proliferation and cancer progression. Therefore, inhibition of FoxM1 represents a therapeutic strategy for treating pancreatic cancer. Broussoflavonol B (BF-B), isolated from the stem bark of Broussonetia kazinoki Siebold has previously been shown to inhibit the growth of breast cancer cells. This study aimed to investigate whether BF-B exhibits anti-pancreatic cancer activity and if so, identify the underlying mechanism. BF-B reduced cell proliferation, induced cell cycle arrest, and inhibited cell migration and invasion of human pancreatic cancer PANC-1 cells (p53 mutated). Interestingly, BF-B down-regulated FoxM1 expression at both the mRNA and protein level. It also suppressed the expression of FoxM1 downstream target genes, such as cyclin D1, cyclin B1, and survivin. Cell cycle analysis showed that BF-B induced the arrest of G0/G1 phase. BF-B reduced the phosphorylation of extracellular signal-regulated kinase ½ (ERK½) and expression of ERK½ downstream effector c-Myc, which regulates cell proliferation. Furthermore, BF-B inhibited cell migration and invasion, which are downstream functional properties of FoxM1. These results suggested that BF-B could repress pancreatic cancer cell proliferation by inactivation of the ERK/c-Myc/FoxM1 signaling pathway. Broussoflavonol B from Broussonetia kazinoki Siebold may represent a novel chemo-therapeutic agent for pancreatic cancer.

Fridericia platyphylla (Cham.) L.G. Lohmann root extract exerts cytotoxic and antiproliferative effects on gastric tumor cells and downregulates BCL-XL, BIRC5, and MET genes.

Fridericia platyphylla (Cham.) L.G. Lohmann (FP) has cytotoxic, anti-inflammatory, and analgesic properties. We aimed to characterize the cytotoxic and antiproliferative effects of FP extract on normal (GAS) and tumor-derived (ACP02 and HepG2) cell lines. The effective concentrations (EC50s) by tetrazolium bromide assay (MTT) were 56.16, 43.68, and 42.57 µg mL-1 and 69.38, 41.73, and 52.39 µg mL-1 by neutral red assay for GAS, ACP02, and HepG2 cells, respectively. The extract decreased nuclear division indices, which was not reflected in cell proliferation curves. Flow cytometric analyses showed that even 30 µg mL-1 extract (shown to be noncytotoxic by MTT assay) increased the sub-G1 population, indicating cell death due to apoptosis and necrosis. A cytokinesis-block micronucleus cytome assay showed that 30 µg mL-1 of the extract increased the frequency of nuclear buds in tumor cells. Real-time quantitative polymerase chain reaction showed CCND1 upregulation in doxorubicin-treated GAS cells and BCL-XL, BIRC5, and MET downregulation in 5 or 30 µg mL-1 in FP extract-treated ACP02 cells. In conclusion, FP extract modulated apoptosis- and cell cycle-related genes and presented selective cytotoxicity toward tumor cells that deserves further investigation by testing other cell types. Our results demonstrated that even medicinal plants exert adverse effects depending on the extract concentrations used and tissues investigated.

mRNA Guided Intracellular Self-Assembly of DNA-Gold Nanoparticle Conjugates as a Precise Trigger to Up-Regulate Cell Apoptosis and Activate Photothermal Therapy.

The size of nanoparticles was generally accepted to have a close relationship with the penetration and retention properties among tumor sites, which is one of the most significant issues during nanomedicine delivery. Despite the outstanding stealth property when circulating and the penetration ability in tumor tissue, small nanoparticles still have the problem of inadequate retention time. Taking advantage of the precise self-assembly of DNA-nanoparticle conjugates, we developed an intracellular assembly system to realize the change of nanoparticle size from small to large as well as activation of therapeutic function inside cancer cells. A duplex sequence of cancer-cell-specific mRNA, survivin, was selected to hybridize with complementary sequence of gold nanoparticle-DNA (AuNP-DNA) conjugates in cancer cell cytoplasm, resulting in the specific and precise formation of intracellular assemblies. Enhanced retention behavior of AuNPs inside cancer cells was shown to be achieved because of the increased nanoparticle size. Meanwhile, an up-regulation effect of cell apoptosis and an activated photothermal therapy function were also created by the formation of AuNP aggregations, and eventually contributed to a high rate of cancer cells death up to 93.33%. In contrast, it exhibited almost no toxicity toward normal cells because of the absence of survivin-induced assembly. Therefore, this mRNA guided intracellular assembly system exhibited its potential as a new precise cancer therapy strategy, and also broadened the application field of DNA-conjugated nanoparticle assembly.

An engineered mouse embryonic stem cell model with survivin as a molecular marker and EGFP as the reporter for high throughput screening of embryotoxic chemicals in vitro.

Embryonic stem cell test (EST) is the only generally accepted in vitro method for assessing embryotoxicity without animal sacrifice. However, the implementation and application of EST for regulatory embryotoxicity screening are impeded by its technical complexity, long testing period, and limited endpoint data. In this study, a high throughput embryotoxicity screening based on mouse embryonic stem cells (mESCs) expressing enhanced green fluorescent protein (EGFP) driven by a human survivin promoter and a human cytomegalovirus promoter, respectively, was developed. These EGFP expressing mESCs were cultured in three-dimensional (3D) fibrous scaffolds in microbioreactors on a multiwell plate with EGFP fluorescence signals as cell responses to chemicals monitored noninvasively in a high throughput manner. Nine chemicals with known developmental toxicity were used to validate the survivin-based embryotoxicity assay, which showed that strongly embryotoxic compounds such as 5-fluorouracil, retinoic acid, and methotrexate downregulated survivin expression by more than 50% in 3 days, while weakly embryotoxic compounds such as boric acid, methoxyacetic acid, and tetracyclin showed modest downregulation effect and nonembryotoxic saccharin, penicillin G, and acrylamide had negligible downregulation effect on survivin expression, confirming that survivin can be used as a molecular endpoint for high throughput screening of embryotoxicants. The potential developmental toxicity of three Chinese herbal medicines were also evaluated using this assay, demonstrating its application in in vitro developmental toxicity test for drug safety assessment.

The concurrent effect of acyclovir and rosemary on glioblastoma cell culture.

Human cytomegalovirus (HCMV) is a beta herpesvirus which large amount of people in world has interacted with. Recent studies indicated that CMV DNA is associated with several cancer types including "Glioblastoma (GBM)" which is the most common and aggressive type of primary brain cancer. In clinical studies it was shown that several antiviral medicines prolonged life span of glioblastoma patients. One of them is Acyclovir (ACV) which is a type of nucleoside analog, used to cure viral infections and might be a potential treatment supplement for Glioblastoma. In this study we aimed to investigate if ACV had cytotoxic effect on glioblastoma cell line U87 MG and also the effect of ACV on healthy cells. Furthermore it was aimed to search the effect of Rosmarinus Officinalis also known as rosemary which is an aromatic, perennial plant concurrent with ACV on glioblastoma and healthy cells.

Calebin-A induced death of malignant peripheral nerve sheath tumor cells by activation of histone acetyltransferase.

BACKGROUND: Neurofibromatosis type 1 (NF1) is one of the most common hereditary neurocutaneous disorders. The malignant peripheral nerve sheath tumor (MPNST), transformed from NF1 related plexiform neurofibroma, is a rapidly growing and highly invasive tumor. No effective chemotherapeutic agent is currently available. Calebin-A is a derivative from turmeric Curcuma longa. Given the anti-inflammatory and anticancer potentials of curcumin, whether Calebin-A also had the tumoricidal effect upon MPNST cells is still elusive. PURPOSE: To determine whether Calebin-A has the potential for anti-MPNST effect. METHODS: The MTT and FACS analysis of normal Schwann (HSC) and MPNST cells have been employed to determine the tumoricidal effect of Calebin-A. The expression of the signal pathway molecules was assessed by Western blotting. The CHIP with quantitative PCR assay was performed to quantify the promoter DNA binding to acetylated histone 3 (acetyl H3). The enzyme activities of histone acetyltransferase (HAT) and deacetylase (HDAC) have been evaluated by commercial kits. The measurements of tumor size of the xenograft mouse model were also performed. RESULTS: Calebin-A inhibited the proliferation of MPNST and primary neurofibroma cells in a dose-dependent manner. The flow cytometry analysis of the MPNST cells after treatment of 25 µm of Calebin-A demonstrated an increase of population in the G0/G1 phase but decrease in G2/M phase. Before treatment, the expression of Axl, Tyro3, and acetyl H3 was significantly higher in MPNST cells when compared to HSC. The expression of phosphorylated-AKT, -ERK1/2, survivin, hTERT, and acetyl H3 proteins were reduced after treatment. The CHIP assay shows the promoter DNA copies of survivin (BRIC5) and hTERT genes are significantly reduced post-treatment. The enzyme activity of HAT was significantly reduced, but not that of HDAC. Two HAT inhibitors, epigallocatechin-3-gallate (EGCG) and anacardic acid (AA) have also demonstrated a significant inhibitory effect on MPNST cells. Finally, the measurements of tumor size showed a significant reduction of the xenograft tumors after treatment of Calebin-A. CONCLUSION: Both in vitro and in vivo studies showed Calebin-A could inhibit the proliferation of MPNST with suppression of survivin and hTERT. The reduced expression of these two factors might be through the epigenetic histone modification resulting from the decreased activity of HAT.

Cucurbitacin B Induces Hypermethylation of Oncogenes in Breast Cancer Cells.

Breast cancer is a complex disease driven by multiple factors including both genetic and epigenetic alterations. Recent studies revealed that abnormal gene expression induced by epigenetic changes including aberrant promoter methylation plays a critical role in human breast carcinogenesis. Cucurbitacin B has antiproliferative activity against various human breast cancer cells, but the molecular mechanism is not completely understood. In this study, we explore the influence of cucurbitacin B from Trichosanthes cucumerina on the methylation status at the promoter of oncogenes c-Myc, cyclin D1, and survivin in breast cancer cell lines. Growth inhibitory effect of cucurbitacin B on breast cancer cells was assessed by MTT assay and colony formation assay. Methylation status of genomic DNA was determined by methylation-specific PCR. Gene and protein expression levels of all genes studied were analyzed by real-time RT-PCR and western blot. The results indicated that cucurbitacin B could inhibit cell growth in breast cancer cells. The oncogene promoters are usually hypomethylated in cancer cells. Upon cucurbitacin B treatment, upregulation of DNMT1 and obvious heavy methylation in the promoters of c-Myc, cyclin D1, and survivin, which consequently downregulated the expression of all these oncogenes, were observed. Hence, cucurbitacin B proved to be a potential cancer therapeutic agent, in part by inducing hypermethylation and silences the oncogenic activation.

Scrophularia Atropatana Extract Reverses TP53 Gene Promoter Hypermethylation and Decreases Survivin Antiapoptotic Gene Expression in Breast Cancer Cells

Background: In many cases of breast cancer, the aberrant methylation of TP53 gene leads to uncontrolled cell proliferation and apoptosis inhibition. Moreover, expression of oncogenes which are under the control of P53 protein could be altered. Survivin as a conspicuous example of this category plays important roles in tumorigenesis, drug resistance and apoptosis inhibition. The present study was done to reveal the effects of Scrophularia atropatana extract on epigenetic situation of TP53 gene promoter and the expression levels of anti-apoptotic gene, survivin and its potential for production of cancer epi-drugs. Methods: Cytotoxic effect of dichloromethane extracts of Scrophularia plant on MCF-7 cell line was assessed in our previous study. Cell death ELISA (enzyme-linked immunosorbent assay) and TUNEL (Terminal deoxynucleotidyl transferase dUTP nick end labeling) tests were used to investigate the occurrence of apoptosis in the treated cells. Methylation Specific PCR (MSP) was employed to assess the changes in methylation status of the TP53 gene promoter. Furthermore, quantitative real time PCR was utilized to evaluate the resulting changes in TP53 and survivin genes expression. Results: Cell death ELISA and TUNEL assays confirmed the occurrence of apoptosis. MSP test revealed a significant change in the methylation status of TP53 promoter. QRT-PCR showed an increased TP53 gene expression in the treated cells while a significant decrease in survivin mRNA was evident. Conclusions: According to the outcomes, dichloromethane extract of S. atropatana returned the TP53 gene promoter hypermethylation to normal state. This plant could be a promising source for production of epi-drugs due to its apoptotic effects and reversal of TP53 epigenetic alterations.

Procyanidin-B2 enriched fraction of cinnamon acts as a proteasome inhibitor and anti-proliferative agent in human prostate cancer cells.

Altered activity of the proteolytic machine-the 26S proteasome is observed in many disease conditions. Hence, either inhibition or activation of the 26S proteasome is thought to be a novel therapy for treatment of certain diseases such as cancer and neurodegenerative disorders. In this study, we tested the potential of cinnamon and one of its active ingredients, procyanidin-B2 (PCB2), in inhibiting the catalytic activities of the proteasome and suppressing prostate cancer cell growth. Proteasome activities were measured using fluorogenic substrates specific for the different enzymatic activities of the 26S proteasome by flourometry. Cell viability was assessed using the 3-[4, 5-dimethylthiazol-2-yl]-2.5-diphenyl-tetrazolium bromide assay, while apoptosis was examined by Hoechst and propidium iodide staining and caspase-3 activity. Both, the cinnamon extract and its PCB2-enriched F2 fraction inhibited the catalytic activities of the purified proteasome and the proteasome in cancer cells but not in normal cells. Furthermore, cinnamon and its active component decreased cell proliferation of human prostate cancer cells but not normal lung cells, decreased expression of anti-apoptotic and angiogenic markers in prostate cancer cell lysates. These results demonstrate that cinnamon extract and its PCB2-enriched fraction act as proteasome inhibitors and have prospects as anti-cancer agents. © 2018 IUBMB Life, 70(5):445-457, 2018.

Yin Yang 1 (YY1): Regulation of Survivin and Its Role In Invasion and Metastasis.

Despite significant clinical and basic science advancements, cancer remains a devastating disease that affects people of all ages, races, and backgrounds. The pathogenesis of cancer has recently been described to result from eight biological capabilities or hallmarks and two enabling characteristics. These eight hallmarks are: deregulation of cellular energetics, avoiding immune destruction, enabling replicative immortality, inducing angiogenesis, sustaining proliferative signaling, evading growth suppressors, resisting cell death, and activating invasion and metastasis. The enabling characteristics are: genome instability and mutation and tumor-promoting inflammation. Survivin, the fourth most common transcript found in cancer cells, is a protein that is thought to be involved in the enhanced proliferation, survival, and metastasis and possibly other key hallmarks of cancer cells. Understanding how this gene is turned on and off is vitally important for attempt improving cancer management and therapy. Our work has identified a novel transcriptional regulator of survivin called Yin Yang 1 (YY1), which has been observed to activate some gene promoters and repress others and is gaining increasing interest as a target of cancer therapy. Our work shows for the first time that YY1 represses survivin transcription by physically interacting with the survivin promoter. Furthermore, YY1 appears to contribute to basal survivin transcriptional activity, indicating that disruption of its binding may in part contribute to survivin overexpression after cellular stress events including chemotherapy and radiotherapy.