Survivin Protein Levels Research Articles

RTID-04. A MULTICENTER, RANDOMIZED, CONTROLLED PHASE 2B TRIAL OF SURVIVIN VACCINE SURVAXM PLUS ADJUVANT TEMOZOLOMIDE FOR NEWLY-DIAGNOSED GLIOBLASTOMA (SURVIVE)

Abstract BACKGROUND Glioblastoma cells express high levels of survivin protein, whose presentation by MHC class I gets recognized by antibodies and cytotoxic T-lymphocytes (CTLs). A phase 2a trial (NCT02455557) demonstrated a median overall survival (OS) of 25.9 months in newly-diagnosed glioblastoma (nGBM) patients with 15-amino-acid-peptide-conjugate survivin vaccine (SurVaxM), which also stimulated production of survivin-directed antibodies and anti-tumor CTL. This phase 2b trial aims to further investigate efficacy and safety of SurVaxM plus adjuvant temozolomide (TMZ) for nGBM. METHODS SURVIVE is an ongoing, multicenter, randomized, placebo-controlled, investigator- and patient-blinded, phase 2b trial that randomizes nGBM patients receiving standard-of-care therapies to either SurVaxM (SurVaxM arm) or saline (control arm) in 3:2 ratio at 15 sites. Included patients have age ≥18 years, normal organ function, KPS≥70, and receive surgical resection with ≤1cm3 residual MRI contrast enhancement within 72 hours post-resection plus TMZ. Patients with recurrent, multicentric, brainstem- or cerebellar-origin GBM are excluded as well as patients on TTFields or other immunotherapies. All patients undergo 3 phases: (1) vaccine priming (VP) phase, starting ≤4 weeks after completing chemoradiation – 4 doses of SurVaxM or placebo administered q2weeks; (2) TMZ phase, started after ≥1 VP dose; and (3) vaccine maintenance phase, started 8 weeks after VP, with SurVaxM or placebo given q8weeks. TMZ phase overlaps with VP and VM phases. Primary endpoint is median OS. Assuming 1-year-OS of 75% in SurVaxM arm, based on prior trials, and 60% for control, the required sample size is N=228; 137 in SurVaxM and 91 in control arm. Accounting for dropouts, we aimed to enroll 239 patients. A log-rank test stratified by KPS (70-80 vs 90-100), MGMT methylation status, and IDH mutation status will be used for analysis. Secondary endpoints are OS and PFS at 15, 18, and 24 months, median PFS, and toxicity. A single sequential OS-driven interim analysis is planned when 50% of deaths occur. Trial is fully enrolled (NCT05163080).

Anthocyanin Oligomers Induce Apoptosis and Autophagy by Inhibiting the mTOR Signaling Pathway in Human Breast Cancer Cells.

Anthocyanin oligomers (AOs) are phytochemicals synthesized by fermenting anthocyanins extracted from grape skins and are more biologically active than monomeric anthocyanins. In this study, we evaluate the effects of an AO on triple-negative MDA-MB-231 and HER2-overexpressing SK-BR-3 breast cancer cells. The cell viability of MDA-MB-231 and SK-BR-3 cells was significantly inhibited in a concentration-dependent manner by AO treatment for 24 h, while delphinidin (a monomeric anthocyanin) had no effect on cell viability. In addition, the AO increased H2A.X phosphorylation (a marker of DNA damage), reduced RAD51 (a DNA repair protein) and survivin (a cell survival factor) protein levels, and induced apoptosis by caspase-3-dependent PARP1 cleavage in both cell lines. Surprisingly, the AO induced autophagy by increasing intracellular LC3-II puncta and LC3-II and p62 protein levels. In addition, the AO inhibited the mTOR pathway in MDA-MB-231 and SK-BR-3 cells by suppressing the HER2, EGFR1, and AKT pathways. These results demonstrate that the anti-cancer effect of the AO was due to the induction of apoptosis and autophagy via cleaved caspase-3-mediated PARP1 cleavage and mTOR pathway inhibition, respectively. Furthermore, our results suggest that anthocyanin oligomers could be considered potential candidates for breast cancer treatment.

Lead exposure induces neuronal apoptosis via NFκB p65/RBBP4/Survivin signaling pathway

Lead (Pb), as a heavy metal that is easily exposed in daily life, can cause damage to various systems of body. Apoptosis is an autonomous cell death process regulated by genes in order to maintain the stability of internal environment, which plays an important role in the development of nervous system. RB binding protein 4 (RBBP4) is one of the core histone binding subunits and is closely related to the apoptosis process of nervous system cells. However, it is not known whether RBBP4 can regulate neuronal apoptosis in lead-exposed environments. We exposed PC12 cells to 0 μM (control group), 1 μM, and 100 μM PbAc for 24 h to obtain cell samples. The female rats ingested drinking water containing 0, 0.5 g/L, and 2.0 g/L PbAc from the first day of pregnancy to three weeks after delivery to obtain hippocampal tissue samples from mammary rats. The results of TUNEL showed that lead exposure promoted the onset of apoptosis in cells and hippocampus. The mRNA and protein levels of the apoptosis-related protein Survivin were significantly reduced in the lead-exposed group compared to the control group. In addition, we found that lead exposure reduces the mRNA and protein levels of RBBP4 in PC12 cells and hippocampus, and increases the mRNA and protein levels of NFκB p65. Moreover, inhibiting NFκB p65 can reverse the decrease in RBBP4 expression in the lead exposure model. Overexpression of RBBP4 increased Survivin expression and reduced apoptosis induced by lead exposure. This suggests that lead exposure induces apoptosis through the NFκB p65/RBBP4/Survivin signaling pathway.

Effect of Aurora kinase B on polyploidy and decidualization in mouse uterus.

Decidualization is critical to the establishment of mouse normal pregnancy. The fibroblast-like stromal cells in the process form polyploid multinucleated cells. Aurora kinase B (Aurora B) has previously been shown to regulate polyploidy in various cells. However, whether Aurora B regulates the formation of decidual cell polyploidization and its regulatory mechanisms remain poorly understood. Establish decidualization model of mouse primary endometrial stromal cells in vitro. Construct pseudopregnancy mouse models and delayed-activation mouse models. Detect Aurora B and polyploidization related genes in mouse uteri treated by Aurora B specific inhibitor Barasertib and CPT. In this study, we found that Aurora B was strongly expressed in endometrial stromal cells after implantation. Additionally, Aurora B was remarkably up regulated in the stromal cells of oil-induced deciduomoa and in vitro decidualization. As an Aurora B specific inhibitor, Barasertib significantly inhibits the mRNA expression of Prl8a2, a marker of mouse decidualization. Furthermore, the protein levels of p-Plk1, Survivin and p-Cdk1 were inhibited by Barasertib. CPT-induced DNA damage suppressed Aurkb (encodes Aurora B) expression, thus resulting in polyploidization. Our data shows that Aurora B is expressed in decidual stromal cells of implantation sites and plays a key role for mouse decidualization. The protein of Plk1, Survivn, and Cdk1 may participate in formation of decidual cell polyploidization during mouse decidualization.

A novel EGFR inhibitor, HNPMI, regulates apoptosis and oncogenesis by modulating BCL-2/BAX and p53 in colon cancer.

Colorectal cancer (CRC) is the second most lethal disease, with high mortality due to its heterogeneity and chemo-resistance. Here, we have focused on the epidermal growth factor receptor (EGFR) as an effective therapeutic target in CRC and studied the effects of polyphenols known to modulate several key signalling mechanisms including EGFR signalling, associated with anti-proliferative and anti-metastatic properties. Using ligand- and structure-based cheminformatics, we developed three potent, selective alkylaminophenols, 2-[(3,4-dihydroquinolin-1(2H)-yl)(p-tolyl)methyl]phenol (THTMP), 2-[(1,2,3,4-tetrahydroquinolin-1-yl)(4-methoxyphenyl)methyl]phenol (THMPP) and N-[2-hydroxy-5-nitrophenyl(4'-methylphenyl)methyl]indoline (HNPMI). These alkylaminophenols were assessed for EGFR interaction, EGFR-pathway modulation, cytotoxic and apoptosis induction, caspase activation and transcriptional and translational regulation. The lead compound HNPMI was evaluated in mice bearing xenografts of CRC cells. Of the three alkylaminophenols tested, HNPMI exhibited the lowest IC50 in CRC cells and potential cytotoxic effects on other tumour cells. Modulation of EGFR pathway down-regulated protein levels of osteopontin, survivin and cathepsin S, leading to apoptosis. Cell cycle analysis revealed that HNPMI induced G0/G1 phase arrest in CRC cells. HNPMI altered the mRNA for and protein levels of several apoptosis-related proteins including caspase 3, BCL-2 and p53. HNPMI down-regulated the proteins crucial to oncogenesis in CRC cells. Assays in mice bearing CRC xenografts showed that HNPMI reduced the relative tumour volume. HNPMI is a promising EGFR inhibitor for clinical translation. HNPMI regulated apoptosis and oncogenesis by modulating BCL-2/BAX and p53 in CRC cell lines, showing potential as a therapeutic agent in the treatment of CRC.

Cullin7 induces docetaxel resistance by regulating the protein level of the antiapoptotic protein Survivin in lung adenocarcinoma cells.

Lung adenocarcinoma (LUAD) is the most common subtype of non-small cell lung cancer (NSCLC). Chemotherapy resistance is the main cause of chemotherapy failure. Cullin7 (Cul7) is highly expressed in LUAD and is associated with poor prognosis. Moreover, Cul7 is abnormally overexpressed in docetaxel-resistant LUAD cells. Therefore, further exploration of the role and molecular mechanism of Cul7 in LUAD docetaxel resistance is necessary. We established docetaxel-resistant cell lines (A549DTX and H358DTX cell lines) by exposing cells to gradually increasing concentrations of docetaxel. Cell (A549, A549DTX, H358, and H358DTX cell lines) sensitivity to docetaxel was determined via a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymmethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay. And then quantitative polymerase chain reaction (qPCR) and Western blotting were performed to measure the expression of Cul7 and Survivin in A549, A549DTX, H358, and H358DTX cell lines. Subsequently, we knocked down Cul7 in docetaxel-resistant cells and overexpressed Cul7 in parental cells via lentiviral transduction to further validate the correlation between Cul7 and docetaxel resistance, while exploring the molecular mechanism of docetaxel resistance it caused. Immunofluorescence and immunohistochemical (IHC) staining were also used to evaluate the expression and cellular localization of Cul7. To confirm the effect of Cul7 expression on cell apoptosis, we used flow cytometry to detect the apoptosis rate of A549 and A549DTX cells with the same drug concentration. Cul7 was highly expressed in A549DTX and H358DTX cells. However, when Cul7 expression was knocked down in A549DTX and H358DTX cells, cell sensitivity to docetaxel was significantly increased. In addition, we found that Cul7 was coexpressed with Survivin. Silencing Survivin reversed the docetaxel insensitivity caused by Cul7 overexpression. High expression of Cul7 and Survivin in docetaxel-resistant LUAD cells inhibited the intrinsic apoptosis pathway and promoted cell proliferation. Therefore, the Cul7/Survivin axis may play a role in inducing LUAD docetaxel chemoresistance. Cul7 and Survivin were both highly expressed in docetaxel-resistant LUAD cells. Our results suggest that Cul7 may inhibit apoptosis and promote the proliferation of LUAD cells by increasing the Survivin protein level, which in turn contributes to docetaxel chemoresistance in LUAD.

WIF1 was downregulated in cervical cancer due to promoter methylation.

Wnt inhibitory factor 1 (WIF1) is frequently downregulated in a variety of cancer due to promoter methylation. However, the methylation status of the WIF1 promoter in cervical cancer remains unclear. This study aimed to elucidate the mechanism by which WIF1 promoter methylation contributes to cervical cancer development. The expression of WIF1 in cervical cancer tissues was examined by immunohistochemistry. The methylation status of the WIF1 promoter in cervical cancer cells was detected by methylation specific PCR. WIF1 mRNA levels and protein levels were detected by PCR and Western blot analysis. We found that WIF1 expression was low in cervical cancer tissues compared to adjacent normal cervical tissues. The WIF1 promoter was methylated in the cervical cancer SiHa cell line but not in the normal cervical epithelial cell line Ect1. Correspondingly, WIF1 mRNA levels and protein levels were significantly lower in SiHa cells than in Ect1 cells. Treatment with 5-aza-2-deoxycytidine (AZA) led to the upregulation of WIF1 mRNA and protein levels in SiHa cells, but the effects were abrogated by treatment with WIF1 siRNA. In addition, AZA treatment induced apoptosis and inhibited the invasion of SiHa cells, and the effects were abrogated by WIF1 siRNA. The protein levels of survivin, c-myc and cyclinD1 were significantly lower in SiHa cells treated with AZA, but their levels were upregulated after treatment with WIF1 siRNA. In conclusion, the methylation of the WIF1 promoter leads to the downregulation of WIF1 and the activation of Wnt/β-catenin signaling in cervical cancer cells. WIF1 is a tumor suppressor that is inactivated in cervical cancer.

LncRNA RP11-521C20.3 Inhibits Cigarette Smoke Extract-Induced Apoptosis in A549 Cells by Targeting BMF Signaling.

LncRNAs are closely correlated with chronic obstructive pulmonary disease (COPD). We investigated the molecular mechanism of lncRNA RP11-521C20.3, which targets the action of the Bcl-2 modifying factor (BMF) signaling pathway in the apoptosis of cigarette smoke extract (CSE)-treated A549 cells. Lung tissues derived from cigarette smoke exposed rats (COPD group) and controls were examined using TUNEL assay for apoptotic cells and using immunohistochemistry for BMF expression levels. Overexpression and knockdown of BMF by lentiviral vector transfection were used to explore the role of BMF on the apoptosis of CSE-treated A549 cells. Overexpression and knockdown of RP11-521C20.3 were used to assess the effect of RP11-521C20.3 on the expression levels of BMF and apoptosis in CSE-treated A549 cells. Cell proliferation, mitochondrial morphology, and apoptosis were assessed in A549 cells. Real-time quantitative polymerase chain reactions and Western blotting detected the expression of apoptosis-related molecules. The number of apoptotic cells and the level of BMF protein were significantly increased in lung tissues of the COPD group compared to the control group. Overexpression of BMF or knockdown of RP11-521C20.3 in CSE-treated A549 cells increased apoptosis, inhibited cell proliferation, and exacerbated mitochondrial damage. There were also increased protein levels of p53, cleaved caspase-3, and cleaved caspase-7, and decreased protein levels of Bcl-2 and survivin. Knockdown of BMF or overexpression of RP11-521C20.3 in CSE-treated A549 cells attenuated apoptosis, promoted cell proliferation, and alleviated mitochondrial damage. Observed effects also included decreased protein levels of p53, cleaved caspase-3, and cleaved caspase-7, and increased protein levels of Bcl-2 and survivin. In CSE-treated A549 cells, overexpression of RP11-521C20.3 suppressed the expression of BMF mRNA and protein. In CSE-treated A549 cells, BMF promoted apoptosis and RP11-521C20.3 might target the BMF signaling axis to protect CSE-treated A549 cells from apoptosis.

Role of hypoxia-inducible factor-1α and survivin in breast cancer recurrence and prognosis

ObjectiveTo analyze the expression of hypoxia-inducible factor-1α (HIF-1α) and survivin in breast cancer, and different molecular subtypes of breast cancer and to assess their relationship with recurrence and prognosis. MethodsThe expression levels of HIF-1α and survivin genes in breast cancer were investigated using bioinformatics. Their protein expression levels were then verified through immunohistochemistry (IHC), and their relationship with recurrence and prognosis was assessed. ResultsExpression levels of HIF-1α and survivin genes and proteins were increased in breast cancer tissues compared with normal tissues. Both were associated with clinical features of breast cancer and differentially expressed in different molecular subtypes of breast cancer, and both are related to the signal pathway of breast cancer growth and invasion. HIF-1α and survivin gene and protein expression levels were correlated, and both were associated with breast cancer recurrence (R = 0.380, P < 0.05; R = 0.673, P < 0.05, respectively). According to The Cancer Genome Atlas (TCGA) database, HIF1A and BIRC5 gene were not associated with breast cancer prognosis (P ≥ 0.05); however, HIF-1α and survivin protein were associated with recurrence patient's overall survival (OS) (P < 0.05). ConclusionHIF-1α and survivin are highly expressed in breast cancer and can be used as potential biomarkers to predict recurrence and assess prognosis.

Trioleyl Pyridinium, a Cationic Transfection Agent for the Lipofection of Therapeutic Oligonucleotides into Mammalian Cells

One of the most significant limitations that therapeutic oligonucleotides present is the development of specific and efficient delivery vectors for the internalization of nucleic acids into cells. Therefore, there is a need for the development of new transfection agents that ensure a proper and efficient delivery into mammalian cells. We describe the synthesis of 1,3,5-tris[(4-oelyl-1-pyridinio)methyl]benzene tribromide (TROPY) and proceeded to the validation of its binding capacity toward oligonucleotides, the internalization of DNA into the cells, the effect on cell viability, apoptosis, and its capability to transfect plasmid DNA. The synthesis and chemical characterization of TROPY, which can bind DNA and transfect oligonucleotides into mammalian cells through clathrin and caveolin-mediated endocytosis, are described. Using a PPRH against the antiapoptotic survivin gene as a model, we validated that the complex TROPY-PPRH decreased cell viability in human cancer cells, increased apoptosis, and reduced survivin mRNA and protein levels. TROPY was also able to stably transfect plasmid DNA, as demonstrated by the formation of viable colonies upon the transfection of a dhfr minigene into dhfr-negative cells and the subsequent metabolic selection. TROPY is an efficient transfecting agent that allows the delivery of therapeutic oligonucleotides, such as PPRHs and plasmid DNA, inside mammalian cells.

PLK1 and AURKB phosphorylate survivin differentially to affect proliferation in racially distinct triple-negative breast cancer

Protein diversity due to alternative mRNA splicing or post-translational modifications (PTMs) plays a vital role in various cellular functions. The mitotic kinases polo-like kinase 1 (PLK1) and Aurora B (AURKB) phosphorylate survivin, an inhibitor of apoptosis (IAP) family member, thereby regulating cell proliferation. PLK1, AURKB, and survivin are overexpressed in triple-negative breast cancer (TNBC), an aggressive breast cancer subtype. TNBC is associated with high proliferative capacity, high rates of distant metastasis, and treatment resistance. The proliferation-promoting protein survivin and its activating kinases, PLK1 and AURKB, are overexpressed in TNBC. In this study, we investigated the role of survivin phosphorylation in racial disparities in TNBC cell proliferation. Analysis of TCGA TNBC data revealed higher expression levels of PLK1 (P = 0.026) and AURKB (P = 0.045) in African Americans (AAs; n = 41) than in European Americans (EAs; n = 86). In contrast, no significant racial differences in survivin mRNA or protein levels were observed. AA TNBC cells exhibited higher p-survivin levels than EA TNBC cells. Survivin silencing using small interfering RNAs significantly attenuated cell proliferation and cell cycle progression in AA TNBC cells, but not in EA TNBC cells. In addition, PLK1 and AURKB inhibition with volasertib and barasertib significantly inhibited the growth of AA TNBC xenografts, but not of EA TNBC tumors. These data suggest that inhibition of PLK1 and AURKB suppresses cell proliferation and tumor growth, specifically in AA TNBC. These findings suggest that targeting survivin phosphorylation may be a viable therapeutic option for AA patients with TNBC.

The prognostic effect of immunohistochemical staining rates in patients with non-muscle-invasive bladder cancer.

Despite the follow-up protocols developed in non-muscle-invasive bladder cancer patients, progression and recurrence could not be prevented. We aimed to investigate whether proteins such as OCT-4, CD47, p53, Ki-67, and Survivin, which increase in bladder cancer cells, can be used as prognostic markers for patients with non-muscle-invasive bladder cancer. The study included a total of 89 patients with newly diagnosed non-muscle-invasive bladder cancer between January 2015 and December 2020. Levels of OCT-4, CD47, p53, Kİ-67, and Survivin proteins in cancer cells were determined with a semi-quantitative immunohistochemical experiment. Pathological data and survival rates were compared according to the staining rates. Data obtained in the study were analyzed statistically with SPSS 22.0 (SPSS, Chicago, IL, USA). The mean age of the patients was 64.25 ± 9.91 years, and the median follow-up period was 55 months. Recurrence rate was determined to be 36% (n = 32), and the rate of progression at 40.4% (n = 36). The staining rates were stronger for each marker in the progression group and advanced-stage tumors (p < 0.001). The findings of the multivariate analysis carried out as part of the study showed that older age and higher tumor stage were independent risk factors for recurrence-free survival (HR = 1.048 and 7.074, respectively; P = 0.02). Also, higher tumor stages, diameters, and grades were associated with reduced progression-free survival (HR = 0.105, 0.395, 0.225, respectively; P < 0.05). Although immunohistochemical staining rates are promising, it is more appropriate to use tumor characteristics when assessing survival rate in patients with non-muscle-invasive bladder cancer.

Dioscin inhibiting EGFR-mediated Survivin expression promotes apoptosis in oral squamous cell carcinoma cells.

Overexpression of survivin plays a crucial role in tumorigenesis and correlates with poor prognosis in human malignancies, including oral squamous cell carcinoma (OSCC). Thus, survivin has been proposed as an attractive target for new antitumor interventions. In the present study, we found that a natural compound, Dioscin, inhibited OSCC cells by reducing the survivin protein level and activating apoptotic signaling. Dioscin inhibits survivin expression by interrupting EGFR binding to the AT-rich sequences (ATRSs) at the survivin promoter, eventually promoting survivin-mediated cell apoptosis. The in vivo study showed that Dioscin suppressed the tumor development of SCC25 cells. Furthermore, the immunohistochemistry (IHC) results revealed that treated with Dioscin reduced the protein levels of EGFR and survivin in SCC25 xenograft tumors. Overall, our findings indicate that targeting the EGFR-survivin axis might be a promising OSCC treatment strategy.

Butein promotes ubiquitination-mediated survivin degradation inhibits tumor growth and overcomes chemoresistance

Overexpression of survivin is frequently observed in human malignancies and is associated with poor prognosis. The present study found that survivin is highly expressed in nasopharyngeal carcinoma (NPC) tumor tissues. Depleting survivin with shRNA inhibited cell viability, colony formation, and in vivo tumorigenesis of NPC cells. With a natural product screening, we identified Butein as a potential anti-tumor compound for NPC by reducing survivin protein level. Butein shortened the half-life of survivin and enhanced ubiquitination-mediated degradation. The mechanism study showed that Butein promoted the interaction between survivin and E3 ligase Fbxl7, and the knockdown of Fbxl7 compromised Butein-induced survivin ubiquitination. Butein suppressed the Akt-Wee1-CDK1 signaling and decreased survivin Thr34 phosphorylation, facilitating E3 ligase Fbxl7-mediated survivin ubiquitination and degradation. Moreover, Butein exhibited a strong in vivo anti-tumor activity, as the tumor volume of Butein-treated xenografts was reduced significantly. Butein alone or combined with cisplatin (CDDP) overcame chemoresistance in NPC xenograft tumors. Overall, our data indicate that Butein is a promising anti-tumor agent for NPC treatment.

Co-inhibition of Aurora A and Haspin kinases enhances survivin blockage and p53 induction for mitotic catastrophe and apoptosis in human colorectal cancer

Colorectal cancer (CRC) is a leading cause and mortality worldwide. Aurora A and haspin kinases act pivotal roles in mitotic progression. However, the blockage of Aurora A and Haspin for CRC therapy is still unclear. Here we show that the Haspin and p-H3T3 protein levels were highly expressed in CRC tumor tissues of clinical patients. Overexpression of Haspin increased the protein levels of p-H3T3 and survivin in human CRC cells; conversely, the protein levels of p-H3T3 and survivin were decreased by the Haspin gene knockdown. Moreover, the gene knockdown of Aurora A induced abnormal chromosome segregation, mitotic catastrophe, and cell growth inhibition. Combined targeted by co-treatment of CHR6494, a Haspin inhibitor, and MLN8237, an Aurora A inhibitor, enhanced apoptosis and CRC tumor inhibition. MLN8237 and CHR6494 induced abnormal chromosome segregation and mitotic catastrophe. Meanwhile, MLN8237 and CHR6494 inhibited survivin protein levels but conversely induced p53 protein expression. Ectopic survivin expression by transfection with a survivin-expressed vector resisted the cell death in the MLN8237- and CHR6494-treated cells. In contrast, the existence of functional p53 increased the apoptotic levels by treatment with MLN8237 and CHR6494. Co-treatment of CHR6494 and MLN8237 enhanced the blockage of human CRC xenograft tumors in nude mice. Taken together, co-inhibition of Aurora A and Haspin enhances survivin inhibition, p53 pathway induction, mitotic catastrophe, apoptosis and tumor inhibition that may provide a potential strategy for CRC therapy.

(−)-Gossypol enhances the anticancer activity of epirubicin via downregulating survivin in hepatocellular carcinoma

Epirubicin (EPI)-based transarterial chemoembolization is an effective therapy for advanced hepatocellular carcinoma (HCC). However, EPI-induced survivin expression limits its tumor-killing potential in HCC. Interestingly, (−)-gossypol ((−)-Gsp), a male contraceptive, suppresses various malignancies. More importantly, (−)-Gsp also holds promise for enhancing the antitumor effects of chemotherapy in numerous cancer types. In the present study, we demonstrated for the first time that (−)-Gsp-sensitized EPI inhibited cell growth and induced apoptosis of HCC cells in vitro. Furthermore, (−)-Gsp sensitized EPI by attenuating the EPI-elevated survivin protein levels. Mechanistic studies showed that EPI stimulated survivin protein synthesis by promoting translation initiation, which was alleviated by (−)-Gsp mainly through suppressing the AKT-4EBP1/p70S6K-survivin and ERK-4EBP1-survivin pathways. HCC xenograft experiments in nude mice also showed that (−)-Gsp treatment acted synergistically with EPI to repress xenograft tumor growth. Overall, our proof-of-concept results may pave the way for novel strategies for the treatment of HCC based on the combination of EPI and (−)-Gsp.

Effects of radiofrequency radiation on apoptotic and antiapoptotic factors in colorectal cancer cells

ABSTRACT In this study, it is aimed to investigate the effect of radiofrequency radiation (RFR) on apoptotic and antiapoptotic factors under different exposure conditions in human colonic adenocarcinoma cells (Caco-2). We analyzed the effects of 2.5 GHz continuous wave and 3 GPP modulated radiofrequency radiation exposure (15 min on, 15 min off) for 1 h and (1 h on, 1 h off) for 3 hours on Caco-2 cell lines. The cell viability of Caco-2 cells was determined by XTT method. Then, the cells were analyzed by flow cytometry to determine the effects on apoptosis staining with AnnexinV-FITC and PI. Protein expression levels of Bcl-2, Bax, Caspase-3 and Survivin were subsequently analyzed by using flow cytometric methods. Bax, Caspase 8, and Survivin protein levels were also analyzed by western blot. The cell viability rates were not significantly different after 2.5 GHz of RFR exposure for 1 h, but RFR exposure for 3 h at 2.5 GHz frequencies caused a decrease on cell viability of Caco-2 cells. RFR exposure for 1 and 3 hours at 2.5 GHz frequencies resulted in an apoptotic response. Protein analyses of Bcl-2, Bax, Survivin, Caspase-3, and Caspase-8 showed that RFR led to increase the levels of proapoptotic Bax, Caspase-3, and Caspase 8 in Caco-2 cells under different exposure conditions. However, 3-h exposure caused a decrease in antiapoptotic survivin levels. The results of our study indicate that RFR exposure affects the cell death mechanism due to apoptotic pathway.

Regulation of p53 and survivin by Curcuma longa extract to caspase-3 dependent apoptosis in triple negative breast cancer cells.

Aim Triple negative breast cancer cells (TNBC) are the population of breast cancer cells that are responsible for cancer recurrence and apoptosis resistance. Unfortunately, current therapies have limited efficacy to TNBC population due to apoptosis resistance and chemoresistance. Tumour suppressor p53 and survivin are primary targets for TNBC therapy. Consequently, a search for a natural compound which targets p53 and survivin is needed to further advance TNBC treatment. Curcuma longa extract (CL), a natural compound induces apoptosis in several cancer cells by targeting various molecules and possess fewer side effects. However, a possible potential of CL as p53- and survivin modulating agent in TNBC cells has not been investigated. Methods MDAMB-231 cells were treated with several concentration of CL, after which, viability, p53 gene expression, surviving protein expression, and caspase-3 protein expression were evaluated. Results After 24-h treatment, CL possessed cytotoxic effect with IC50 value of 13 μg/mL. Treatment with 1.625, 3.25, 6.5, and 13 μg/mL of CL resulted in 2.70-25.80% increase in caspase-3 expression levels followed by 94.60 - 21.60% decrease in survivin protein levels. CL induced remarkably p53 gene expression ratio up to 5-fold at 13 μg/mL. Survivin protein levels were inversely proportional to p53 accumulation levels. Low survivin protein levels combined with high levels of p53 accumulation were correlated to higher apoptotic rates. Conclusion p53 and survivin as molecular targets of CL contribute to caspase-3-dependent apoptosis in TNBC cells and this compound represents an attractive p53- and survivin modulating agent in TNBC.

Elucidating the Anticancer Mechanism of Arachidin‐1 in Triple‐Negative Breast Cancer Cells

Triple‐negative breast cancer (TNBC) is one of the deadliest forms of breast cancer that affects women worldwide. TNBC is unresponsive to standard hormonal cancer treatments, leading to high mortality rates. Treatment resistance and low survival rates necessitate investigating alternative treatment options for this type of cancer. Plant natural products, such as the prenylated stilbenoid arachidin‐1 from peanut, have shown cytotoxicity to certain cancer cells. To this end, the goal of this study was to examine the apoptotic effects of arachidin‐1 in TNBC cell lines MDA‐MB‐231 and MDA‐MB‐436. To produce arachidin‐1, peanut hairy root cultures were co‐treated with elicitors, and arachidin‐1 was purified from extracts of the culture medium by semi‐preparative high performance liquid chromatography. The apoptotic effects of arachidin‐1 were studied via western blotting by checking the protein levels of PARP, caspase‐8, caspase‐9, and survivin. Vinculin and GAPDH were used as protein loading controls. Results showed that as arachidin‐1 concentration increased, the amount of cleaved PARP also increased. Similarly, the levels of cleaved caspase‐9 increased as concentrations of arachidin‐1 increased. Whereas the level of survivin, an apoptosis inhibitor protein, decreased at increasing concentrations of arachidin‐1. The increased expression of cleaved PARP, cleaved caspase‐9, and reduced surviving expression in TNBC cells treated with arachidin‐1 represents the activation of intrinsic apoptosis in the cells. This accentuates the importance of expanding our understanding of the connection between stilbenoids and triple‐negative breast cancer cells. In future research, we will study the effect of arachidin‐1 on signaling pathways in TNBC cell lines.

Helicobacter pylori-induced reactive oxygen species direct turnover of CSN-associated STAMBPL1 and augment apoptotic cell death

Deubiquitinylases (DUBs) are central regulators of the ubiquitin system involved in protein regulation and cell signalling and are important for a variety of physiological processes. Most DUBs are cysteine proteases, and few other proteases are metalloproteases of the JAB1/MPN +/MOV34 protease family (JAMM). STAM-binding protein like 1 (STAMBPL1), a member of the JAMM family, cleaves ubiquitin bonds and has a function in regulating cell survival, Tax-mediated nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and epithelial-mesenchymal transition. However, the molecular mechanism by which STAMBPL1 influences cell survival is not well defined, especially with regard to its deubiquitinylation function. Here, we show that reactive oxygen species (ROS) induced by chemotherapeutic agents or the human microbial pathogen Helicobacter pylori can induce cullin 1-RING ubiquitin ligase (CRL1) and 26S proteasome-dependent degradation STAMBPL1. Interestingly, STAMBPL1 has a direct interaction with the constitutive photomorphogenic 9 (COP9 or CSN) signalosome subunits CSN5 and CSN6. The interaction with the CSN is required for the stabilisation and function of the STAMBPL1 protein. In addition, STAMBPL1 deubiquitinylates the anti-apoptotic protein Survivin and thus ameliorates cell survival. In summary, our data reveal a previously unknown mechanism by which the deubiquitinylase STAMBPL1 and the E3 ligase CRL1 balance the level of Survivin degradation and thereby determine apoptotic cell death. In response to genotoxic stress, the degradation of STAMBPL1 augments apoptotic cell death. This new mechanism may be useful to develop therapeutic strategies targeting STAMBPL1 in tumours that have high STAMBPL1 and Survivin protein levels.