Survivin: key regulator of mitosis and apoptosis and novel target for cancer therapeutics

Expression of survivin does not appear to influence breast cancer recurrence risk

BACKGROUND

Survivin is an inhibitor of apoptosis, and its expression associates with poor outcomes in multiple cancers. It may be a therapeutic target due to its unique expression in cancer cells.

METHODS

We estimated the association between nuclear and cytoplasmic survivin expression in primary tumors and breast cancer recurrence. In this case-control study, we included women age 35-69, diagnosed with stage I-III breast cancer between 1985 and 2001, and registered with the Danish Breast Cancer Group. We identified 541 patients with breast cancer recurrence with estrogen receptor-positive disease who were treated with tamoxifen for at least 1 year (ER+/TAM+) and 300 with estrogen receptor-negative carcinomas, not treated with tamoxifen, and who survived at least 1 year (ER-/TAM-). Controls were matched to cases on ER/TAM status, date of surgery, menopausal status, stage and county. Survivin expression was estimated by immunohistochemistry on tissue microarrays. We fit logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) associating nuclear and cytoplasmic survivin expression with recurrence.

RESULTS

Associations between nuclear and cytoplasmic survivin expression and breast cancer recurrence were near-null in both ER+/TAM + and ER-/TAM - strata. For the cytoplasmic to nuclear ratio (CNR) of survivin expression, we found a null association in the ER+/TAM + group comparing CNR ≥5 with CNR <5, but an association (OR =2.48, 95% CI: 1.15, 5.31) in the ER-/TAM - group.

CONCLUSIONS

Survivin expression was not associated with breast cancer recurrence in this study. The CNR ratio may warrant further investigation especially among ER - tumors.

Treatment with DHA Modifies the Response of MDA-MB-231 Breast Cancer Cells and Tumors from nu/nu Mice to Doxorubicin through Apoptosis and Cell Cycle Arrest

Background

Docosahexaenoic acid (DHA) has been shown to reduce growth of breast cancer cells in vitro and in vivo; it may also benefit the action of cytotoxic cancer drugs. The mechanisms for these observations are not completely understood.

Objectives

We sought to explore how pretreatment of MDA-MB-231 breast cancer cells with DHA alters gene expression with doxorubicin (DOX) treatment and confirm that feeding DHA to tumor-bearing nu/nu mice improves the efficacy of DOX.

Methods

MDA-MB-231 cells were subjected to 4 conditions: a control mixture of 40 μM linoleic and 40 μM oleic acid (OALA), DHA (60 μM plus OALA), OALA DOX (0.41 μM), or DHA DOX (plus OALA) and assessed for effects on viability and function. Female nu/nu mice (6 wk old) bearing MDA-MB-231 tumors were randomly assigned to a nutritionally complete diet (20 g ± 2.8 g DHA/100 g diet) containing a polyunsaturated:saturated fat ratio of 0.5, with or without injections 2 times/wk of 5 mg DOX/kg for 4 wk.

Results

Microarray and protein analysis indicated that DHA DOX cells, compared with OALA DOX, had upregulated expression of apoptosis genes, Caspase-10 (1.3-fold), Caspase-9 (1.4-fold), and Receptor (TNFRSF)-interacting serine-threonine kinase 1 (RIPK1) (1.2-fold), while downregulating cell cycle genes, Cyclin B1 (-2.1-fold), WEE1 (-1.6-fold), and cell division cycle 25 homolog C (CDC25C) (-1.8-fold) (P < 0.05). DHA DOX-treated mice had 50% smaller tumors than control mice (P < 0.05). Analysis of proapoptotic proteins from tumors of DHA DOX mice showed increased Caspase-10 (by 68%) and BH3 interacting domain death agonist (Bid) (by 50%), decreased B-cell CLL/lymphoma 2 (BCL2) (by 24%), and decreased cell cycle proteins Cyclin B1 and Cdc25c (both by 42%), compared with control mice (P < 0.05).

Conclusions

Supplementation with DHA facilitates the action of DOX in MDA-MB-231 cells and in nu/nu mice, which may occur via amplification of the effect of DOX on apoptosis and cell cycle genes.

Determining consistent prognostic biomarkers of overall survival and vascular invasion in hepatocellular carcinoma

Background: Potential prognostic biomarker candidates for hepatocellular carcinoma (HCC) are abundant, but their generalizability is unexplored. We cross-validated markers of overall survival (OS) and vascular invasion in independent datasets. Methods: The literature search yielded 318 genes related to survival and 52 related to vascular invasion. Validation was performed in three datasets (RNA-seq, n = 371; Affymetrix arrays, n = 91; Illumina gene chips, n = 135) by uni- and multivariate Cox regression and Mann-Whitney U-test, separately for Asian and Caucasian patients. Results: One hundred and eighty biomarkers remained significant in Asian and 128 in Caucasian subjects at p < 0.05. After multiple testing correction BIRC5 (p = 1.9 × 10^-10), CDC20 (p = 2.5 × 10^-9) and PLK1 (p = 3 × 10^-9) endured as best performing genes in Asian patients; however, none remained significant in the Caucasian cohort. In a multivariate analysis, significance was reached by stage (p = 0.0018) and expression of CENPH (p = 0.0038) and CDK4 (p = 0.038). KIF18A was the only gene predicting vascular invasion in the Affymetrix and Illumina cohorts (p = 0.003 and p = 0.025, respectively). Conclusion: Overall, about half of biomarker candidates failed to retain prognostic value and none were better than stage predicting OS. Impact: Our results help to eliminate biomarkers with limited capability to predict OS and/or vascular invasion.

Establishment of in vitro and in vivo anti-colon cancer efficacy of essential oils containing oleo-gum resin extract of Mesua ferrea

Proven the great potential of essential oils as anticancer agents, the current study intended to explore molecular mechanisms responsible for in vitro and in vivo anti-colon cancer efficacy of essential oil containing oleo-gum resin extract (RH) of Mesua ferrea. MTT cell viability studies showed that RH had broad spectrum cytotoxic activities. However, it induced more profound growth inhibitory effects towards two human colon cancer cell lines i.e., HCT 116 and LIM1215 with an IC₅₀ values of 17.38 ± 0.92 and 18.86 ± 0.80 μg/mL respectively. RH induced relatively less toxicity in normal human colon fibroblasts i.e., CCD-18co. Cell death studies conducted, revealed that RH induced characteristic morphological and biochemical changes in HCT 116. At protein level it down-regulated expression of multiple pro-survival proteins i.e., survivin, xIAP, HSP27, HSP60 and HSP70 and up-regulated expression of ROS, caspase-3/7 and TRAIL-R2 in HCT 116. Furthermore, significant reduction in invasion, migration and colony formation potential was observed in HCT 116 treated with RH. Chemical characterization by GC-MS and HPLC methods revealed isoledene and elemene as one the major compounds. RH showed potent antitumor activity in xenograft model. Overall, these findings suggest that RH holds a promise to be further studied for cheap anti-colon cancer naturaceutical development.

Acrofolione A and B, acetophenone dimers from Acronychia pendunculata, induce an apoptotic effect on human NALM-6 pre-B cell leukaemia cells

OBJECTIVES

We investigated the apoptotic activities of acrofolione A (1) and B (2) isolated from Acronychia pedunculata against a human pre-B cell leukaemia cell line (NALM-6) to explore the apoptosis-related signalling molecules targeted by 1 and 2.

METHODS

The apoptosis effects of 1 and 2 in NALM-6 cells were investigated by TUNEL staining, annexin V, mitochondria membrane potential and caspase 3/7 activity. We carried out a protein array to explore the signalling molecules involved in apoptosis comprehensively.

KEY FINDINGS

Acrofolione A (1) suppressed the growth of NALM-6, K562 and HPB-ALL cells (IC₅₀ 16.7 ± 1.9, 17.9 ± 0.3 and 10.1 ± 0.2 μm, respectively) more effectively than acrofolione B (2). Both compounds time-dependently increased the number of NALM-6 cells with abnormal nuclei, and increased the number of annexin V-positive cells and decreased the mitochondrial membrane potential of NALM-6 cells. Acrofolione A (1) markedly elevated caspase 3/7 activity and increased the number of TUNEL-positive cells. Cells treated with either compound showed enhanced expression of cleaved PARP and cleaved caspase 3 and 7, and reduced survivin protein levels.

CONCLUSIONS

Acrofolione A (1) and B (2) may be useful in the treatment of various types of leukaemia.

Interplay between Endoplasmic Reticular Stress and Survivin in Colonic Epithelial Cells

Sustained endoplasmic reticular stress (ERS) is implicated in aggressive metastasis of cancer cells and increased tumor cell proliferation. Cancer cells activate the unfolded protein response (UPR), which aids in cellular survival and adaptation to harsh conditions. Inhibition of apoptosis, in contrast, is a mechanism adopted by cancer cells with the help of the inhibitor of an apoptosis (IAP) class of proteins such as Survivin to evade cell death and gain a proliferative advantage. In this study, we aimed to reveal the interrelation between ERS and Survivin. We initially verified the expression of Survivin in Winnie (a mouse model of chronic ERS) colon tissues by using immunohistochemistry (IHC) and immunofluorescence (IF) in comparison with wild type Blk6 mice. Additionally, we isolated the goblet cells and determined the expression of Survivin by IF and protein validation. Tunicamycin was utilized at a concentration of 10 µg/mL to induce ERS in the LS174T cell line and the gene expression of the ERS markers was measured. This was followed by determination of inflammatory cytokines. Inhibition of ERS was carried out by 4Phenyl Butyric acid (4PBA) at a concentration of 10 mM to assess whether there was a reciprocation effect. The downstream cell death assays including caspase 3/7, Annexin V, and poly(ADP-ribose) polymerase (PARP) cleavage were evaluated in the presence of ERS and absence of ERS, which was followed by a proliferative assay (EdU click) with and without ERS. Correspondingly, we inhibited Survivin by YM155 at a concentration of 100 nM and observed the succeeding ERS markers and inflammatory markers. We also verified the caspase 3/7 assay. Our results demonstrate that ERS inhibition not only significantly reduced the UPR genes (Grp78, ATF6, PERK and XBP1) along with Survivin but also downregulated the inflammatory markers such as IL8, IL4, and IL6, which suggests a positive correlation between ERS and the inhibition of apoptosis. Furthermore, we provided evidence that ERS inhibition promoted apoptosis in LS174T cells and shortened the proliferation rate. Moreover, Survivin inhibition by YM155 led to a comparable effect as that of ERS inhibition, which includes attenuation of ERS genes and inflammatory markers as well as the promotion of programmed cell death via the caspase 3/7 pathway. Together, our results propose the interrelation between ERS and inhibition of apoptosis assigning a molecular and therapeutic target for cancer treatment.

Metformin and JQ1 synergistically inhibit obesity-activated thyroid cancer

Compelling epidemiological evidence shows a strong positive correlation of obesity with thyroid cancer. In vivo studies have provided molecular evidence that high-fat-diet-induced obesity promotes thyroid cancer progression by aberrantly activating leptin-JAK2-STAT3 signaling in a mouse model of thyroid cancer (Thrb^PV/PVPten^+/- mice). The Thrb^PV/PVPten^+/- mouse expresses a dominantly negative thyroid hormone receptor β (denoted as PV) and a deletion of one single allele of the Pten gene. The Thrb^PV/PVPten^+/- mouse spontaneously develops follicular thyroid cancer, which allows its use as a preclinical mouse model to test potential therapeutics. We recently showed that inhibition of STAT3 activity by a specific inhibitor markedly delays thyroid cancer progression in high-fat-diet-induced obese Thrb^PV/PVPten^+/- mice (HFD-Thrb^PV/PVPten^+/- mice). Further, metformin, a widely used antidiabetic drug, blocks invasion and metastasis, but not thyroid tumor growth in HFD-Thrb^PV/PVPten^+/- mice. To improve efficacy in reducing thyroid tumor growth, we treated HFD-Thrb^PV/PVPten^+/- with JQ1, a potent inhibitor of the activity of bromodomain and extraterminal domain (BET) and with metformin. We found that the combined treatment synergistically suppressed thyroid tumor growth by attenuating STAT3 and ERK signaling, resulting in decreased anti-apoptotic key regulators such as Mcl-1, Bcl-2 and survivin and increased pro-apoptotic regulators such as Bim, BAD and cleave caspase 3. Furthermore, combined treatment of JQ1 and metformin reduced cMyc protein levels to suppress vascular invasion, anaplasia and lung metastasis. These findings indicate that combined treatment is more effective than metformin alone and suggest a novel treatment modality for obesity-activated thyroid cancer.

RecQL4-Aurora B kinase axis is essential for cellular proliferation, cell cycle progression, and mitotic integrity

Human RecQL4 helicase plays critical roles in the maintenance of genomic stability. Mutations in RecQL4 helicase results in three clinically related autosomal recessive disorders: Rothmund–Thomson syndrome (RTS), RAPADILINO, and Baller–Gerold syndrome. In addition to several premature aging features, RTS patients are characterized by aneuploidy involving either loss or gain of a single chromosome. Chromosome mosaicism and isochromosomes involving chromosomes 2, 7, and 8 have been reported in RecQL4-deficient RTS patients, but the precise role of RecQL4 in chromosome segregation/stability remains to be elucidated. Here, we demonstrate that RecQL4 physically and functionally interacts with Aurora B kinase (AURKB) and stabilizes its expression by inhibiting its ubiquitination process. Our study indicates that the N-terminus of RecQL4 interacts with the catalytic domain of AURKB. Strikingly, RecQL4 suppression reduces the expression of AURKB leading to mitotic irregularities and apoptotic cell death. RecQL4 suppression increases the proportion of cells at the G2/M phase followed by an extensive cell death, presumably owing to the accumulation of mitotic irregularities. Both these defects (accumulation of cells at G2/M phase and an improper mitotic exit to sub-G1) are complemented by the ectopic expression of AURKB. Finally, evidence is provided for the requirement of both human telomerase reverse transcriptase and RecQL4 for stable immortalization and longevity of RTS fibroblasts. Collectively, our study suggests that the RecQL4–AURKB axis is essential for cellular proliferation, cell cycle progression, and mitotic stability in human cells.

Butein induces apoptotic cell death of human cervical cancer cells

Butein is a chalcone, a flavonoid that is widely biosynthesized in plants. Butein has been identified to possess varied pharmacological activity and is extractable from traditional Chinese medicinal herbs, therefore applicable for disease treatment. Recently, in vitro and in vivo studies have shown that butein may induce apoptotic cell death in various human cancer cells. In this study we investigated the apoptotic effect of butein and the underlying mechanisms in human cervical cancer cells. Two cell lines, C-33A and SiHa cells, were treated with butein at different dosages for different durations. The effect of butein on cell viability was assessed by MTT assay, which revealed that butein exerted cytotoxicity in both cervical cancer cells in a dose- and time-dependent fashion. Apoptotic pathway-related factors in the butein-treated cervical cancer cells were then examined. JC-1 flow cytometry, cytochrome c assay, and caspase activity assays demonstrated that butein disturbed mitochondrial transmembrane potential, and increased cytosolic cytochrome c levels and caspase activities in both cervical cancer cells. Western blot analysis revealed that butein downregulated anti-apoptotic protein Bcl-xL and led to proteolytic cleavage of poly (ADP-ribose) polymerase. In addition, butein decreased expressions of the inhibitor of apoptosis (IAP) proteins, including X-linked IAP, survivin, and cellular IAP-1. The findings of this study suggest that butein can decrease cervical cancer cell viability via a pro-apoptotic effect, which involves inhibition of the IAP proteins and activation of both extrinsic and intrinsic pro-apoptotic pathways. Therefore, butein may be applicable for cervical cancer treatment.

Kaempferol, a natural dietary flavonoid, suppresses 17β-estradiol-induced survivin expression and causes apoptotic cell death in endometrial cancer

Endometrioid endometrial carcinoma, commonly known as type 1 endometrial cancer, accounts for >80% of endometrial carcinomas and is dependent on estrogen. We recently reported on the prognostic significance of the BIRC5 survivin gene in endometrial cancer. Estradiol induces survivin expression in estrogen receptor-positive, but not in estrogen receptor-negative, cancer cells. Kaempferol, a bioflavonoid, reportedly inhibits estrogen receptor-α (ERα) in hormone receptor-positive breast cancer cells. However, whether kaempferol-mediated inhibition of ERα suppresses survivin and induces cell death in endometrial cancer remains unclarified. The present study evaluated the antitumor effects of kaempferol on endometrial cancer cells. Cell viability assays, flow cytometry analysis, western blotting and annexin V analyses were used to analyze the antitumor effects of kaempferol. The results demonstrated that kaempferol successfully suppressed the viability of two ER-positive endometrial cancer cell lines, with IC₅₀ values of 83 and 65 µM. In addition, kaempferol induced sub-G1 cell accumulation and apoptotic cell death (P<0.01) in a dose-dependent manner. Treatment of cells with estradiol significantly induced co-expression of nuclear ERα and survivin proteins (P<0.001). Further evaluation revealed that kaempferol causes apoptotic cell death largely by suppressing ERα, survivin and Bcl-2 protein. Therefore, the results of the present study suggested that targeting ERα and survivin with kaempferol may be a novel therapeutic option against endometrial carcinoma.

Cytotoxicity of AMANTADIG - a semisynthetic digitoxigenin derivative - alone and in combination with docetaxel in human hormone-refractory prostate cancer cells and its effect on Na+/K+-ATPase inhibition

Cardiac glycosides (CGs) are natural compounds used to treat congestive heart failure. They have garnered attention as a potential cancer treatment option, especially because they bind to Na⁺/K⁺-ATPase as a target and activate intracellular signaling pathways leading to a variety of cellular responses. In this study we evaluated AMANTADIG, a semisynthetic cardenolide derivative, for its cytotoxic activity in two human androgen-insensitive prostate carcinoma cell lines, and the potential synergistic effects with docetaxel. AMANTADIG induced cytotoxic effects in both cell lines, and a combination with docetaxel showed a moderate and strong synergism in DU145 and PC-3 cells, respectively, at concentrations considerably lower than their IC₅₀ values. Cell cycle analyses showed that AMANTADIG and its synergistic combination induced G2/M arrest of DU145 and PC-3 cells by modulating Cyclin B1, CDK1, p21 and, mainly, survivin expression, a promising target in cancer therapy. Furthermore, AMANTADIG presented reduced toxicity toward non-cancerous cell type (PBMC), and computational docking studies disclosed high-affinity binding to the Na⁺/K⁺-ATPase α subunit, a result that was experimentally confirmed by Na⁺/K⁺-ATPase inhibition assays. Hence, AMANTADIG inhibited Na⁺/K⁺-ATPase activity in PC-3 cells, as well as in purified pig kidney at nanomolar range. Altogether, these data highlight the potent effects of AMANTADIG in combination with docetaxel and offer important insights for the development of more effective and selective therapies against prostate cancer.

Berbamine suppresses cell proliferation and promotes apoptosis in ovarian cancer partially via the inhibition of Wnt/β-catenin signaling

Ovarian cancer is a common and lethal cancer affecting women globally. Berbamine is a natural compound from the plant Berberis amurensis, which is used in Chinese traditional medicine. Recent studies have shown the anti-tumor effects of berbamine in several types of cancers but not in ovarian cancer. In the present study, we investigated the potential anti-tumor effects of berbamine in ovarian cancer and explored the underlying molecular mechanisms. Berbamine suppressed the cell viability of ovarian cancer cells in a concentration-dependent manner as revealed by methyl thiazolyl tetrazolium assay. Berbamine also suppressed the cell growth and invasion of ovarian cancer cells as measured by colony formation and cell invasion assays, respectively. Flow cytometry experiments showed that berbamine increased cell apoptotic rate and induced cell cycle arrest at G0/G1 phase in ovarian cancer cells. Western blot analysis showed that berbamine increased the protein levels of cleaved caspase-3, cleaved caspase-9, Bax, and decreased the protein level of Bcl-2 in ovarian cancer cells. Quantitative real-time PCR and western blot analysis demonstrated that berbamine treatment inhibited the Wnt/β-catenin signaling in ovarian cancer cells. The inhibitory effects of berbamine on cell viability and invasion of ovarian cancer cells can be partially reversed by lithium chloride (LiCl) treatment. Growth of tumors developed from SKOV3 cells was significantly suppressed in berbamine-treated group, and berbamine treatment enhanced caspase-3 and -9 cleavage and reduced β-catenin protein level in tumor tissues. In summary, berbamine exerts its anti-cancer effects in vitro and in vivo via induction of apoptosis, partially associated with the inhibition of Wnt/β-catenin signaling.

Hairpin-Hairpin Molecular Beacon Interactions for Detection of Survivin mRNA in Malignant SW480 Cells

Cancer biomarkers offer unique prospects for the development of cancer diagnostics and therapy. One of such biomarkers, protein survivin (Sur), exhibits strong antiapoptotic and proliferation-enhancing properties and is heavily expressed in multiple cancers. Thus, it can be utilized to provide new modalities for modulating the cell-growth rate, essential for effective cancer treatment. Herein, we have focused on the development of a new survivin-based cancer detection platform for colorectal cancer cells SW480 using a turn-on fluorescence oligonucleotide molecular beacon (MB) probe, encoded to recognize Sur messenger RNA (mRNA). Contrary to the expectations, we have found that both the complementary target oligonucleotide strands as well as the single- and double-mismatch targets, instead of exhibiting the anticipated simple random conformations, preferentially formed secondary structure motifs by folding into small-loop hairpin structures. Such a conformation may interfere with, or even undermine, the biorecognition process. To gain better understanding of the interactions involved, we have replaced the classical Tyagi-Kramer model of interactions between a straight target oligonucleotide strand and a hairpin MB with a new model to account for the hairpin-hairpin interactions as the biorecognition principle. A detailed mechanism of these interactions has been proposed. Furthermore, in experimental work, we have demonstrated an efficient transfection of malignant SW480 cells with SurMB probes containing a fluorophore Joe (SurMB-Joe) using liposomal nanocarriers. The green emission from SurMB-Joe in transfected cancer cells, due to the hybridization of the SurMB-Joe loop with Sur mRNA hairpin target, corroborates Sur overexpression. On the other hand, healthy human-colon epithelial cells CCD 841 CoN show only negligible expression of survivin mRNA. These experiments provide the proof-of-concept for distinguishing between the cancer and normal cells by the proposed hairpin-hairpin interaction method. The single nucleotide polymorphism sensitivity and a low detection limit of 26 nM (S/N = 3σ) for complementary targets have been achieved.

Resveratrol Sensitizes Carfilzomib-Induced Apoptosis via Promoting Oxidative Stress in Multiple Myeloma Cells

The proteasome inhibitor is a target therapy for multiple myeloma (MM) patients, which has increased the overall survival rate of multiple myeloma in clinic. However, relapse and toxicity are major challenges for almost all MM patients. Thus, there is an urgent need for an effective and less toxic combination therapy. Here, we demonstrated that a natural compound, resveratrol (RSV) displayed anti-proliferative activity in a dose- and time-dependent manner in a panel of MM cell lines. More importantly, a low concentration of RSV was synergistic with a low dose of the proteasome inhibitor carfilzomib (CFZ) to induce apoptosis in myeloma cells. Further studies showed that mitochondria was a key regulatory site after RSV/CFZ combination treatment. RSV induced the release of second mitochondria-derived activator of caspase (Smac) in a dose-dependent manner and kept the Smac in a high level after combination with CFZ. Also, RSV was additive with CFZ to increase reactive oxygen species (ROS) production. Moreover, a stress sensor SIRT1, with deacetylase enzyme activity, was remarkably downregulated after RSV/CFZ combination, thereby significantly decreasing its target protein, survivin in MM cells. Simultaneously, autophagy was invoked after RSV/CFZ combination treatment in myeloma cells. Further inhibition of autophagy could increase more ROS production and apoptosis, indicating a close linkage between autophagy and proteasome to modulate the oxidative stress. Together, these findings suggest that induction of multiple stress responses after RSV/CFZ combination is a major mechanism to synergistically inhibit MM cell growth and reduce the toxicity of CFZ in MM cells. This study also provides an important rationale for the clinic to consider an autophagy inhibitor for the combination therapy in MM patients.

Polychlorinated biphenyl 138 exposure-mediated lipid droplet enlargement endows adipocytes with resistance to TNF-α-induced cell death

Although epidemiological reports have shown the association between polychlorinated biphenyls (PCBs) and obesity, the molecular mechanism of PCB-induced obesity is mostly unknown. The aim of the present study was to further dissect the significance of lipid droplet (LD) enlargement in PCB-induced obesity. For this aim, we hypothesized that PCB-induced LD enlargement endows adipocytes with resistance to cell death, inhibiting the natural loss of adipocytes. Four types of PCBs were screened, and the detailed molecular mechanism was investigated by using PCB-138. We observed that PCB-138-conferred cell death resistance to hypertrophic adipocytes with enlarged LDs. We further observed that PCB-138 prevents Tumour necrosis factor-α (TNF-α)-induced apoptosis and necroptosis in 3T3-L1 adipocytes and increases the expression of anti-apoptotic proteins, including survivin, in vitro and in vivo. In addition, we demonstrated that fat-specific protein 27 (Fsp27), perilipin, and survivin endow adipocytes with resistance to TNF-α-induced cell death through sustaining enlarged LDs. Thus, the present study suggests that PCB-138-induced LD enlargement endows adipocytes with resistance to TNF-α-induced cell death and that Fsp27, perilipin, and survivin, at least in part, help adipocytes to sustain enlarged LDs, contributing to the induction of obesity.

Synthesis and characterization of radioiodinated 3-phenethyl-2-indolinone derivatives for SPECT imaging of survivin in tumors

Survivin, overexpressed in most cancers, is associated with poor prognosis and resistance to radiation therapy and chemotherapy. Herein, we report the synthesis of three 3-phenethyl-2-indolinone derivatives and their application as in vivo imaging agents for survivin. Of these, 3-(2-(benzo[d][1,3]dioxol-5-yl)-2-oxoethyl)-3-hydroxy-5- iodoindolin-2-one (IPI-1) showed the highest binding affinity (K_d = 68.3 nM) to recombinant human survivin, as determined by quartz crystal microbalance (QCM). In vitro studies demonstrated that the [¹²⁵I]IPI-1 binding in survivin-positive MDA-MB-231 cells was significantly higher than that in survivin-negative MCF-10A cells. In addition, uptake of [¹²⁵I]IPI-1 by MDA-MB-231 cells decreased in a dose-dependent manner in the presence of the high-affinity survivin ligand S12; this is indicative of specific binding of [¹²⁵I]IPI-1 to cellular survivin protein in vitro. Biodistribution studies in MDA-MB-231 tumor-bearing mice demonstrated the moderate uptake of [¹²⁵I]IPI-1 in the tumor tissue (1.37% ID/g) at 30 min that decreased to 0.32% ID/g at 180 min. Co-injection of S12 (2.5 mg/kg) slightly reduced tumor uptake and the tumor/muscle ratio of [¹²⁵I]IPI-1. Although further structural modifications are necessary to improve pharmacokinetic properties, our results indicate that PI derivatives may be useful as tumor-imaging probes targeting survivin.

Natural Borneol Enhances Paclitaxel-Induced Apoptosis of ESCC Cells by Inactivation of the PI3K/AKT

Paclitaxel (PTX) has been used in a variety of malignancies for inhibiting tumor development and improving survival. However, its clinical application is limited due to poor solubility, drug resistance, and gastrointestinal reactions. Natural borneol (NB), as a promoter, could help to improve drug absorption. Therefore, the aims of the present study were to investigate the ability of NB to synergize with PTX to induce human esophageal squamous cell carcinoma (ESCC) cells apoptosis and the underlying mechanism of synergistic effects. In this study, our findings showed that NB could effectively synergize with PTX to inhibit the survival of ESCC cells by inducing apoptosis. The molecular mechanism by western blotting elucidated that combination treatment with PTX and NB significantly activated apoptotic pathway by triggering upregulation of cleaved caspase-3 expression and downregulation of survivin and P-AKT expression. These results demonstrated that NB could strongly potentiate PTX-induced apoptosis in ESCC cells through suppressing PI3K/AKT pathway. Thus, the combination therapy with NB and PTX might be a promising treatment strategy for human esophageal cancer.

PRACTICAL APPLICATION

Esophageal cancer is one of the most common cancers in the world. It has brought about a major public health problem. Many natural agents have been employed in the synergized treatments of esophageal cancer. This study provides a comprehensive way to investigate the ability of borneol to synergize with paclitaxel to induce human esophageal squamous cell carcinoma cells apoptosis and the underlying mechanism of synergistic effects. The research showed that the combination treatment with some natural agents might be a promising treatment strategy for human esophageal cancer.

Survivin knockdown induces senescence in TTF‑1-expressing, KRAS-mutant lung adenocarcinomas

Survivin plays a key role in regulating the cell cycle and apoptosis, and is highly expressed in the majority of malignant tumors. However, little is known about the roles of survivin in KRAS-mutant lung adenocarcinomas. In the present study, we examined 28 KRAS-mutant lung adenocarcinoma tissues and two KRAS-mutant lung adenocarcinoma cell lines, H358 and H441, in order to elucidate the potential of survivin as a therapeutic target. We found that 19 (68%) of the 28 KRAS-mutant lung adenocarcinomas were differentiated tumors expressing thyroid transcription factor-1 (TTF-1) and E-cadherin. Patients with tumors immunohistochemically positive for survivin (n=18) had poorer outcomes than those with survivin-negative tumors (n=10). In the H358 and H441 cells, which expressed TTF-1 and E-cadherin, survivin knockdown alone induced senescence, not apoptosis. However, in monolayer culture, the H358 cells and H441 cells in which survivin was silenced, underwent significant apoptosis following combined treatment with ABT-263, a Bcl-2 inhibitor, and trametinib, a MEK inhibitor. Importantly, the triple combination of survivin knockdown with ABT-263 and trametinib treatment, clearly induced cell death in a three-dimensional cell culture model and in an in vivo tumor xenograft model. We also observed that the growth of the H358 and H441 cells was slightly, yet significantly suppressed in vitro when TTF-1 was silenced. These findings collectively suggest that the triple combination of survivin knockdown with ABT-263 and trametinib treatment, may be a potential strategy for the treatment of KRAS-mutant lung adenocarcinoma. Furthermore, our findings indicate that the well-differentiated type of KRAS-mutant lung tumors depends, at least in part, on TTF-1 for growth.

Proliferation of hepatic stellate cells, mediated by YAP and TAZ, contributes to liver repair and regeneration after liver ischemia-reperfusion injury

Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) are key regulators of cell proliferation and organ size; however, their physiological contribution after liver injury has not been fully understood. In this study, we sought to determine the role of YAP and TAZ during liver recovery after ischemia-reperfusion (I/R). A murine model of partial (70%) I/R was used to induce liver injury and study the reparative and regenerative response. After liver injury, there was marked activation and proliferation of hepatic stellate cells. The Hippo pathway components, large tumor suppressor 1 (LATS1) and its adapter protein, Mps one binder 1 (MOB1), were inactivated during liver repair, and YAP and TAZ were activated selectively in hepatic stellate cells. Concurrently, the expression of connective tissue growth factor and survivin, both of which are YAP and TAZ target genes, were upregulated. Hepatic stellate cell expansion and concomitant activation of YAP and TAZ occurred only in the injured liver and were not observed in the nonischemic liver. Treatment of mice with verteporfin, an inhibitor of YAP and TAZ, decreased hepatic stellate cell proliferation, survivin, and cardiac ankyrin repeat protein expression. These changes were associated with a significant decrease in hepatocyte proliferation. The data suggest that liver repair and regeneration after I/R injury are dependent on hepatic stellate cell proliferation, which is mediated by YAP and TAZ. NEW & NOTEWORTHY This study is the first to assess the proliferation of hepatic stellate cells (HSCs) after ischemia-reperfusion (I/R) injury and their role in the reparative and regenerative process. Here we show that the Hippo pathway is inactivated after I/R and that Yes-associated protein/transcriptional coactivator with PDZ-binding motif (YAP/TAZ) activation is detected in HSC. HSC proliferation and expansion are prominent during liver recovery after I/R injury. Inhibition of YAP/TAZ activation with verteporfin reduces HSC proliferation and target gene expression and attenuates hepatocyte proliferation.

Polygodial analog induces apoptosis in LNCaP prostate cancer cells

Prostate cancer (PCa) is the second leading cause of death in American men. The chemotherapeutic treatment strategies are generally not effective and can lead to side effects. Hence, there is an urgent need to identify novel chemotherapeutic agents. The aim of this study was to synthesize and evaluate the therapeutic effects of a synthetic analog of polygodial (PG), a pungent constituent abundantly present in mountain pepper, water pepper and dorrigo pepper, on LNCaP PCa cell line and its anti-cancer mechanisms in a preclinical study. We evaluated the anti-cancer potential of the PG analog namely DRP-27 using various assays such as cell viability by MTT assay, anchorage independent growth by soft agar assay, reactive oxygen species generation by 2',7'-dichlorofluorescein probe-based fluorescence assay, and apoptosis by Annexin-V and TUNEL assays respectively. Western blot analysis was performed to identify the molecular mechanism of DRP-27-induced cell death. Our results showed that DRP-27 significantly inhibited LNCaP cell proliferation in a dose-dependent manner at 48 h treatment in vitro. In addition, DRP-27 potently inhibited anchorage-independent growth of these cells. Flow cytometry, Annexin-V and TUNEL assays confirmed that DRP-27 induces apoptosis in LNCaP cells. DRP-27 also induced the activation of intracellular reactive oxygen species. Western blot analysis revealed that DRP-27 downregulated the expression of survivin, while activating Bax and DNA damage marker pH₂AX in LNCaP cells. In conclusion, our study suggests that DRP-27 might be an effective anti-cancer agent for PCa.

Ginsenoside Rg3 Sensitizes Colorectal Cancer to Radiotherapy through Downregulation of Proliferative and Angiogenic Biomarkers

Background

Radiation therapy is an important mode of colorectal cancer treatment. However, most people die of local recurrence after tumors become resistant to radiotherapy, and little progress has been made in treating radiotherapy-resistant colorectal cancer. Hence, novel agents that are nontoxic and can sensitize colorectal cancer to radiotherapy are urgently needed. Ginsenoside Rg3, a saponin extracted from ginseng, shows cytotoxicity against a variety of cancer cells through suppression of pathways linked to oncogenesis, including cell survival, proliferation, invasion, and angiogenesis. In this article, we investigated whether Rg3 can sensitize colorectal cancer to radiation in vivo.

Methods and Materials

We established CT-26 xenografts in BALB/c mice and treated them with vehicle, Rg3, radiation, and combined Rg3 + radiation. Mouse quality of life, survival, tumor volumes, and inhibitive rates were estimated. NF-κB activation was ascertained using electrophoretic mobility shift assay and immunohistochemistry. We also tested for markers of proliferation, angiogenesis, and invasion using immunohistochemistry and Western blot analysis.

Results

Rg3 significantly enhanced the efficacy of fractionated radiotherapy by improving the quality of life of mice. Moreover, tumors from mice xenografted with CT-26 cells and treated with combined Rg3 + radiotherapy showed significantly lower tumor volumes (P < 0.01 versus controls; P < 0.05 versus radiation alone), NF-κB activation, and expression of NF-κB-regulated gene products (cyclin D1, survivin, cyclooxygenase-2 (COX-2), and vascular endothelial growth factor (VEGF)) compared with controls. The combination treatment was also effective in suppressing angiogenesis, as indicated by lower CD31⁺ microvessel density compared with controls (P < 0.05).

Conclusion

Our results suggest that Rg3 enhances the antitumor effects of radiotherapy for colorectal cancer by suppressing NF-κB and NF-κB-regulated gene products, leading to inhibition of tumors and prolongation of the lifespan of CT-26 xenograft BALB/c mice.

Survivin as a novel target protein for reducing the proliferation of cancer cells

Survivin, also known as baculoviral inhibitor of apoptosis repeat-containing 5, is a novel member of the inhibitor of apoptosis protein family. Survivin is highly expressed in tumors and embryonic tissues and is associated with tumor cell differentiation, proliferation, invasion and metastasis; however, survivin is expressed at low levels in normal terminally differentiated adult tissues. Meanwhile, the expression level of survivin is also a negative prognostic factor for patients with cancer. These unique characteristics of survivin make it an exciting potential therapeutic target for cancer treatment. This review will discuss the biological characteristics of survivin and its potential use as a treatment target to reduce cancer cell proliferation.

Inhibitor of apoptosis proteins, NAIP, cIAP1 and cIAP2 expression during macrophage differentiation and M1/M2 polarization

Monocytes and macrophages constitute the first line of defense of the immune system against external pathogens. Macrophages have a highly plastic phenotype depending on environmental conditions; the extremes of this phenotypic spectrum are a pro-inflammatory defensive role (M1 phenotype) and an anti-inflammatory tissue-repair one (M2 phenotype). The Inhibitor of Apoptosis (IAP) proteins have important roles in the regulation of several cellular processes, including innate and adaptive immunity. In this study we have analyzed the differential expression of the IAPs, NAIP, cIAP1 and cIAP2, during macrophage differentiation and polarization into M1 or M2. In polarized THP-1 cells and primary human macrophages, NAIP is abundantly expressed in M2 macrophages, while cIAP1 and cIAP2 show an inverse pattern of expression in polarized macrophages, with elevated expression levels of cIAP1 in M2 and cIAP2 preferentially expressed in M1. Interestingly, treatment with the IAP antagonist SMC-LCL161, induced the upregulation of NAIP in M2, the downregulation of cIAP1 in M1 and M2 and an induction of cIAP2 in M1 macrophages.

Salicylate •Phenanthroline copper (II) complex induces apoptosis in triple-negative breast cancer cells

In this study, we investigated anti-tumor activity and associated molecular mechanism of action of Salicylate ●Phenanthroline Copper (II) Complex in triple-negative breast cancer. Salicylate ●Phenanthroline Copper (II) Complex inhibited the growth of four breast cancer cell lines (MCF-7, T47D, MDA-MB-231 and BT-20) and induced apoptosis in a concentration-dependent manner. The effect was more profound in MDA-MB-231 and BT-20 triple-negative breast cancer cell lines. Western blot showed that the expression of the apoptosis-related protein Bcl-2, Bcl-xl and survivin was significantly reduced in MDA-MB-231 after treatment with Salicylate ●Phenanthroline Copper (II) Complex. In vivo, Salicylate ●Phenanthroline Copper (II) Complex administration significantly attenuated tumor growth of MDA-MB-231 xenografts, and the expression levels of Bcl-2, Bcl-xL and survivin were reduced as measured by immunohistochemical staining. These data suggest that Salicylate ●Phenanthroline Copper (II) Complex is a promising novel therapeutic drug for triple-negative breast cancer and warrants further study.

Cabazitaxel inhibits proliferation and potentiates the radiation response of U87MG glioblastoma cells

Cabazitaxel is a second-generation semisynthetic taxane. The recognized anti-neoplastic effect of Cabazitaxel is cell cycle perturbation by inducing arrest at G2/M. Since glioblastoma tumors have a relatively high expression of P-gp, it is encouraging to find a treatment that is effective against these tumors. This study was conducted to examine the radiosensitizing potential of Cabazitaxel against U87MG cells. In order to evaluate the effect of Cabazitaxel, cells were treated with different concentrations of the drug at different time intervals and then cytotoxicity and cell cycle were assessed using MTT and flow cytometry assays, respectively. Annexin/PI and real-time polymerase chain reaction (PCR) assays were used to evaluate the extent of apoptosis. Cabazitaxel exerted a consistent G2/M arrest and resulted in a concentration- and time-dependent toxicity. Cabazitaxel enhanced the cytotoxicity response of U87MG cells to radiation. Apoptosis increased following Cabazitaxel-IR administration. At the same time, these results were further supported by apoptotic genes regulation. This study provides the first preclinical evidence supporting that Cabazitaxel can render U87MG cells more susceptible to the cytotoxicity of radiation and could potentially be administered in combination modalities as a promising cell cycle-specific radiosensitizer for the future steps of in vivo evaluation.

Covalent Strategies for Targeting Messenger and Non-Coding RNAs: An Updated Review on siRNA, miRNA and antimiR Conjugates

Oligonucleotide-based therapy has become an alternative to classical approaches in the search of novel therapeutics involving gene-related diseases. Several mechanisms have been described in which demonstrate the pivotal role of oligonucleotide for modulating gene expression. Antisense oligonucleotides (ASOs) and more recently siRNAs and miRNAs have made important contributions either in reducing aberrant protein levels by sequence-specific targeting messenger RNAs (mRNAs) or restoring the anomalous levels of non-coding RNAs (ncRNAs) that are involved in a good number of diseases including cancer. In addition to formulation approaches which have contributed to accelerate the presence of ASOs, siRNAs and miRNAs in clinical trials; the covalent linkage between non-viral vectors and nucleic acids has also added value and opened new perspectives to the development of promising nucleic acid-based therapeutics. This review article is mainly focused on the strategies carried out for covalently modifying siRNA and miRNA molecules. Examples involving cell-penetrating peptides (CPPs), carbohydrates, polymers, lipids and aptamers are discussed for the synthesis of siRNA conjugates whereas in the case of miRNA-based drugs, this review article makes special emphasis in using antagomiRs, locked nucleic acids (LNAs), peptide nucleic acids (PNAs) as well as nanoparticles. The biomedical applications of siRNA and miRNA conjugates are also discussed.

Therapeutic significance of targeting survivin in cervical cancer and possibility of combination therapy with TRAIL

Loss of p53 function due to human papillomavirus (HPV) infection induces resistance to apoptosis in cervical cancer cells. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which induces apoptosis in a p53-independent manner, may provide an alternative strategy for treating cervical cancer. Survivin, an antiapoptotic protein that is highly expressed in cancer cells, regulates apoptosis and the cell cycle. Here, we investigated the therapeutic potential of targeting survivin, while focusing on the TRAIL-induced apoptosis pathway. The viability and cell cycle of HPV16-positive CaSki and SiHa cells were assessed after survivin knockdown by small interfering RNA (si-survivin). E-cadherin expression was also assessed after si-survivin treatment, using western blotting. SiHa (a TRAIL-resistant cell line) was used for further studies. The small molecule YM155 and resveratrol (RVT; a polyphenol with the potential to suppress survivin expression) were used as survivin inhibitors. The effects of si-survivin and survivin inhibitors on TRAIL- or cisplatin (CDDP)-induced apoptosis were analyzed by annexin-V staining. si-survivin treatment decreased cell viability and led to G2/M arrest, accompanied by morphological changes and E-cadherin upregulation in both CaSki and SiHa cells. si-survivin and YM155 synergistically sensitized TRAIL-resistant SiHa cells to TRAIL-induced apoptosis (p < 0.05). However, si-survivin and YM155 only slightly increased CDDP-induced apoptosis. RVT markedly enhanced TRAIL-induced apoptosis by suppressing survivin expression. Targeting of survivin expression might be an ideal strategy for cervical cancer treatment as it would decrease viable cell number and enhance apoptosis sensitivity. Further, combination therapy with TRAIL, rather than CDDP, may be compatible with the proposed survivin-targeting strategy.

Survivin-targeting miR-542-3p overcomes HER3 signaling-induced chemoresistance and enhances the antitumor activity of paclitaxel against HER2-overexpressing breast cancer

Elevated expression of HER3, which interacts with HER2 in breast cancer cells, confers chemoresistance via phosphoinositide 3-kinase (PI-3K)/Akt-dependent upregulation of Survivin. However, the underlying mechanism is not clear. Ectopic expression or specific knockdown of HER3 in HER2-overexpressing breast cancer cells did not alter Survivin mRNA levels and Survivin protein stability, supporting the notion that HER3 signaling may regulate specific miRNAs that target Survivin to alter its protein translation. Here we showed that overexpression and specific knockdown of HER3 reduced and enhanced expression of two Survivin-targeting miRNAs, miR-203 and miR-542-3p, in breast cancer cells, respectively. While the specific inhibitor of either miR-203 or miR-542-3p attenuated an anti-HER3 antibody-induced downregulation of Survivin, inhibition of miR-542-3p exhibited a better efficacy than miR-203 inhibition did. Consistently, miR-542-3p mimic was much more effective than miR-203 mimic not only in inhibition of Survivin, but also in enhancement of paclitaxel-induced apoptosis in HER2-overexpressing breast cancer cells. Moreover, the combination of miR-542-3p mimic and paclitaxel, as compared with either agent alone, significantly inhibited in vivo tumor growth of HER2-overexpressing breast cancer cells. Collectively, our data indicated that the HER3/PI-3K/Akt signaling upregulates Survivin via suppression of miR-203 and miR-542-3p. Because miR-542-3p has three binding sites on the 3'-UTR of Survivin mRNA, its mimic was able to effectively downregulate Survivin in vitro and in vivo. Thus, miR-542-3p-replacement therapy is an excellent approach to overcome HER3-mediated paclitaxel resistance and significantly enhances the antitumor activity of paclitaxel against HER2-overexpressing breast cancer.

Identification of Inhibitors against Metastasis Protein "Survivin:" In silico Discovery Using Virtual Screening and Molecular Docking Studies

Background:

In experimental therapy of cancer, survivin is considered to be one of the well-established targets. Studies have found that it is overexpression in most of the human tumors, but it is rarely found in normal tissues. It is having varied structural and functional role. It controls cell division and cellular stress response and also regulates metastasis and migration of cancerous cells. It has also been recognized as a biomarker which makes it unconventional drug target. In spite of being one of the centrally active components in metastasis and invasion, their clinical use is minimal. To increase the therapeutic efficiency of cancer and its various stages, it is important to survey novel reagents targeting the pathways and mechanism involving survivin.

Objective:

The aim of this study was to identify novel survivin inhibitor candidates using in silico screening.

Materials and Methods:

In this course of work, virtual screening on a dataset of natural compounds retrieved from ZINC and other libraries were performed. Comparative analysis of the protein was done by studying the binding affinity of inhibitors that are already available. The best interacting complex was set for molecular dynamics simulation for 25 ns to validate the stability of system. These molecules were checked for their toxicity and absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties using OSIRIS and pre-ADMET tools.

Results:

We discovered ten such candidates with better binding efficiency with survivin in comparison to marketed chemical against the same. Furthermore, these inhibitor candidates did not induce cell toxicity. Binding affinity of reference molecules was varied from −6.8 to −8.5 kcal/mol while that of top scoring compound ZINC00689728 is −9.3 kcal/mol binding energy. Good placement and strong bond formation of selected molecule was observed during course of work. It is also having permissible ADMET property.

Conclusion:

Considering all the parameters, the screened molecule can be considered as a potential lead compound for designing new drug against survivin. Further investigation and testing will be required to make it to the final stage.

SUMMARY

Survivin is one of the important protein of metastasis. Inhibiting survivin might led to the increased therapeutic efficiency of cancer. In this work we are screening library of natural compounds in view of finding some potent inhibitor against survivin.

Abbreviations used: MD: Molecular dynamics, LogS: Aqueous solubility, Acceptor HB: Hydrogen bond acceptor, Donor HB: Donor hydrogen bond donor, ADMET: Absorption, distribution, metabolism, excretion, and toxicity, RCSB: Research Collaboratory for Structural Bioinformatics, OPLS: Optimized potentials for liquid simulations, RMSD: Root-mean-square deviation.

Survivin is a novel transcription regulator of KIT and is downregulated by miRNA-494 in gastrointestinal stromal tumors

Gain-of-function mutations of KIT are pathognomonic in sporadic gastrointestinal stromal tumors (GISTs). Several microRNAs have been shown to be dysregulated in GISTs and impact KIT expression. Little is known though on KIT-independent targets of KIT-regulating mRNAs. We sought to investigate how miR-494 inhibits GIST proliferation and to identify novel target gene. We used microarray-based gene expression analyses to identify pathways and target genes affected by miR-494. The expressional relationship between survivin and miR-494 was determined in 35 GIST tissues. Cell proliferation assay, FACS analysis, colony formation assay, promoter assays and chromatin immunoprecipitation (ChiP) were performed to clarify the roles of survivin in GIST progression. Gene expression microarray analysis revealed that miR-494 inhibited GISTs by affecting multiple genes in the cell cycle pathway. Survivin (BIRC5) was a key target of miR-494, and its expression showed an inverse correlation with miR-494 expression in 35 GIST tissues (Pearson's correlation coefficient, r = -0.418, p = 0.012). Downregulation of survivin inhibited proliferation and colony formation, and resulted in cell cycle alteration. Induced survivin overexpression relieved miR-494-mediated inhibition of GIST progression. Targeting PI3K effectively suppressed proliferation of GISTs with downregulation of survivin. Survivin also regulated KIT expression at the transcription level. Immunohistochemical analysis using 113 GISTs revealed that survivin expression was significantly correlated with overall survival of GIST patients (p = 0.004). Our findings indicated that miR-494 synergistically suppressed GISTs by concomitantly targeting survivin and KIT.

Clinicopathological and functional implications of the inhibitor of apoptosis proteins survivin and XIAP in esophageal cancer

Based on their overexpression and important roles in progression and therapy-resistance in malignant diseases, the inhibitor of apoptosis protein family (IAP) members, survivin and X-linked inhibitor of apoptosis protein (XIAP), represent attractive candidates for targeted therapy. The present study investigated the prognostic and biological relevance of survivin and XIAP in esophageal squamous-cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Survivin and XIAP expression was analyzed by immunohistochemistry using tissue microarrays containing 120 ESCC and 90 EAC samples as well as the corresponding non-neoplastic esophageal mucosa samples. IAP expression levels were then correlated to clinicopathological parameters and overall survival to identify any associations. In addition, esophageal cancer cell lines were treated with the survivin inhibitor YM155, and the XIAP inhibitors Birinapant and GDC-0152 in vitro. Survivin and XIAP expression were significantly increased in EAC and ESCC when compared with tumor-adjacent mucosa. In patients with ESCC XIAP expression was associated with female gender and advanced tumor stages, and nuclear survivin expression was associated with poor grading. High XIAP expression was identified as an independent negative prognostic marker in ESCC. By contrast, XIAP inhibitors did not affect cancer cell viability in vitro, and the small molecule survivin inhibitor YM155 significantly reduced cell viability and proliferation in esophageal cancer cell lines. Western blot analysis revealed a dose dependent decrease of survivin accompanied by an increased poly (adenosine diphosphate-ribose) polymerase cleavage following YM155 treatment. These findings underline the potential role of survivin and XIAP in the oncogenesis of esophageal cancer and provide a rationale for future clinical studies investigating the therapeutic efficacy of IAP directed therapies in patients with esophageal cancer.

Identification of a new gene regulatory circuit involving B cell receptor activated signaling using a combined analysis of experimental, clinical and global gene expression data

To discover new regulatory pathways in B lymphoma cells, we performed a combined analysis of experimental, clinical and global gene expression data. We identified a specific cluster of genes that was coherently expressed in primary lymphoma samples and suppressed by activation of the B cell receptor (BCR) through αIgM treatment of lymphoma cells in vitro. This gene cluster, which we called BCR.1, includes numerous cell cycle regulators. A reduced expression of BCR.1 genes after BCR activation was observed in different cell lines and also in CD10⁺ germinal center B cells. We found that BCR activation led to a delayed entry to and progression of mitosis and defects in metaphase. Cytogenetic changes were detected upon long-term αIgM treatment. Furthermore, an inverse correlation of BCR.1 genes with c-Myc co-regulated genes in distinct groups of lymphoma patients was observed. Finally, we showed that the BCR.1 index discriminates activated B cell-like and germinal centre B cell-like diffuse large B cell lymphoma supporting the functional relevance of this new regulatory circuit and the power of guided clustering for biomarker discovery.

Tumorigenic proteins upregulated in the MYCN-amplified IMR-32 human neuroblastoma cells promote proliferation and migration

Childhood neuroblastoma is one of the most common types of extra-cranial cancer affecting children with a clinical spectrum ranging from spontaneous regression to malignant and fatal progression. In order to improve the clinical outcomes of children with high-risk neuroblastoma, it is crucial to understand the tumorigenic mechanisms that govern its malignant behaviors. MYCN proto-oncogene, bHLH transcription factor (MYCN) amplification has been implicated in the malignant, treatment-evasive nature of aggressive, high-risk neuroblastoma. In this study, we used a SILAC approach to compare the proteomic signatures of MYCN-amplified IMR-32 and non-MYCN-amplified SK-N-SH human neuroblastoma cells. Tumorigenic proteins, including fatty-acid binding protein 5 (FABP5), L1-cell adhesion molecule (L1-CAM), baculoviral IAP repeat containing 5 [BIRC5 (survivin)] and high mobility group protein A1 (HMGA1) were found to be significantly upregulated in the IMR-32 compared to the SK-N-SH cells and mapped to highly tumorigenic pathways including, MYC, MYCN, microtubule associated protein Tau (MAPT), E2F transcription factor 1 (E2F1), sterol regulatory element binding transcription factor 1 or 2 (SREBF1/2), hypoxia-inducible factor 1α (HIF-1α), Sp1 transcription factor (SP1) and amyloid precursor protein (APP). The transcriptional knockdown (KD) of MYCN, HMGA1, FABP5 and L1-CAM significantly abrogated the proliferation of the IMR-32 cells at 48 h post transfection. The early apoptotic rates were significantly higher in the IMR-32 cells in which FABP5 and MYCN were knocked down, whereas cellular migration was significantly abrogated with FABP5 and HMGA1 KD compared to the controls. Of note, L1-CAM, HMGA1 and FABP5 KD concomitantly downregulated MYCN protein expression and MYCN KD concomitantly downregulated L1-CAM, HMGA1 and FABP5 protein expression, while survivin protein expression was significantly downregulated by MYCN, HMGA1 and FABP5 KD. In addition, combined L1-CAM and FABP5 KD led to the concomitant downregulation of HMGA1 protein expression. On the whole, our data indicate that this inter-play between MYCN and the highly tumorigenic proteins which are upregulated in the malignant IMR-32 cells may be fueling their aggressive behavior, thereby signifying the importance of combination, multi-modality targeted therapy to eradicate this deadly childhood cancer.

Predictive bioinformatics identifies novel regulators of proliferation in a cancer stem cell model

The cancer stem cell model postulates that tumors are hierarchically organized with a minor population, the cancer stem cells, exhibiting unlimited proliferative potential. These cells give rise to the bulk of tumor cells, which retain a limited ability to divide. Without successful targeting of cancer stem cells, tumor reemergence after therapy is likely. However, identifying target pathways essential for cancer stem cell proliferation has been challenging. Here, using a transcriptional network analysis termed GAMMA, we identified 50 genes whose correlation patterns suggested involvement in cancer stem cell division. Using RNAi depletion, we found that 21 of these target genes showed preferential growth inhibition in a breast cancer stem cell model. More detailed initial analysis of 6 of these genes revealed 4 with clear roles in the fidelity of chromosome segregation. This study reveals the strong predictive potential of transcriptional network analysis in increasing the efficiency of successful identification of novel proliferation dependencies for cancer stem cells.

Chromosomal instability induced by increased BIRC5/Survivin levels affects tumorigenicity of glioma cells

Background

Survivin, belonging to the inhibitor of apoptosis (IAP) gene family, is abundantly expressed in tumors. It has been hypothesized that Survivin facilitates carcinogenesis by inhibition of apoptosis resulting in improved survival of tumorigenic progeny. Additionally, Survivin plays an essential role during mitosis. Together with its molecular partners Aurora B, Borealin and inner centromere protein it secures bipolar chromosome segregation. However, whether increased Survivin levels contribute to progression of tumors by inducing chromosomal instability remains unclear.

Methods

We overexpressed Survivin in U251-MG, SVGp12, U87-MG, HCT116 and p53-deficient U87-MG^shp53 and HCT116^p53−/− cells. The resulting phenotype was investigated by FACS-assisted cell cycle analysis, Western Blot analysis, confocal laser scan microscopy, proliferation assays, spectral karyotyping and in a U251-MG xenograft model using immune-deficient mice.

Results

Overexpression of Survivin affected cells with knockdown of p53, cells harboring mutant p53 and SV40 large T antigen, respectively, resulting in the increase of cell fractions harboring 4n and >4n DNA contents. Increased γH2AX levels, indicative of DNA damage were monitored in all Survivin-transduced cell lines, but only in p53 wild type cells this was accompanied by an attenuated S-phase entry and activation of p21^waf/cip. Overexpression of Survivin caused a DNA damage response characterized by increased appearance pDNA-PKcs foci in cell nuclei and elevated levels of pATM S1981 and pCHK2 T68. Additionally, evolving structural chromosomal aberrations in U251-MG cells transduced with Survivin indicated a DNA-repair by non-homologous end joining recombination. Subcutaneous transplantation of U251-MG cells overexpressing Survivin and mycN instead of mycN oncogene alone generated tumors with shortened latency and decreased apoptosis. Subsequent SKY-analysis of Survivin/mycN-tumors revealed an increase in structural chromosomal aberrations in cells when compared to mycN-tumors.

Conclusions

Our data suggest that increased Survivin levels promote adaptive evolution of tumors through combining induction of genetic heterogeneity with inhibition of apoptosis.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3932-y) contains supplementary material, which is available to authorized users.

Phase I clinical trial of a novel autologous modified-DC vaccine in patients with resected NSCLC

BACKGROUND

The primary aim of this study was to evaluate the safety of a novel dendritic cell (DC) vaccine pulsed with survivin and MUC1, silenced with suppressor of cytokine signaling 1 (SOCS1), and immune stimulated with flagellin for patients with stage I to IIIA non-small cell lung cancer (NSCLC) in a phase I open-label, uncontrolled, and dose-escalation trial. Moreover, we evaluate the potential efficacy of this modified DC vaccine as secondary aim.

METHODS

The patients were treated with the vaccine at 1 × 106, 1 × 107and the maximum dose 8 × 107 at day 7, 14, and 21 after characterization of the vaccine phenotype by flow cytometry. The safety of the vaccine was assessed by adverse events, and the efficacy by the levels of several specific tumor markers and the patient quality of life.

RESULTS

The vaccine was well tolerated without dose-limiting toxicity even at higher doses. The most common adverse event reported was just grade 1 flu-like symptoms without unanticipated or serious adverse event. A significant decrease in CD3 + CD4 + CD25 + Foxp3+ T regulatory (Treg) cell number and increase in TNF-α and IL-6 were observed in two patients. Two patients showed 15% and 64% decrease in carcino-embryonic antigen and CYFRA21, respectively. The vaccination with the maximum dose significantly improved the patients'quality of life when administered at the highest dose. More importantly, in the long-term follow-up until February 17, 2017, 1 patient had no recurrence, 1 patients had a progressive disease (PD), and 1 patient was died in the low dose group. In the middle dose group, all 3 patients had no recurrence. In the high dose group, 1 patient was died, 1 patient had a PD, and the other 7 patients had no recurrence.

CONCLUSIONS

We provide preliminary data on the safety and efficacy profile of a novel vaccine against non-small cell lung cancer, which was reasonably well tolerated, induced modest antitumor activity without dose-limiting toxicity, and improved patients' quality of life. Further more, the vaccine maybe a very efficacious treatment for patients with resected NSCLC to prevent recurrence. Our findings on the safety and efficacy of the vaccine in this phase I trial warrant future phase II/III clinical trial.

Identification of survivin as a promising target for the immunotherapy of adult B-cell acute lymphoblastic leukemia

B-cell acute lymphoblastic leukemia (B-ALL) is a rare heterogeneous disease characterized by a block in lymphoid differentiation and a rapid clonal expansion of immature, non-functioning B cells. Adult B-ALL patients have a poor prognosis with less than 50% chance of survival after five years and a high relapse rate after allogeneic haematopoietic stem cell transplantation. Novel treatment approaches are required to improve the outcome for patients and the identification of B-ALL specific antigens are essential for the development of targeted immunotherapeutic treatments.

We examined twelve potential target antigens for the immunotherapy of adult B-ALL. RT-PCR indicated that only survivin and WT1 were expressed in B-ALL patient samples (7/11 and 6/11, respectively) but not normal donor control samples (0/8). Real-time quantitative (RQ)-PCR showed that survivin was the only antigen whose transcript exhibited significantly higher expression in the B-ALL samples (n = 10) compared with healthy controls (n = 4)(p = 0.015). Immunolabelling detected SSX2, SSX2IP, survivin and WT1 protein expression in all ten B-ALL samples examined, but survivin was not detectable in healthy volunteer samples. To determine whether these findings were supported by the analyses of a larger cohort of patient samples, we performed metadata analysis on an already published microarray dataset. We found that only survivin was significantly over-expressed in B-ALL patients (n = 215) compared to healthy B-cell controls (n = 12)(p = 0.013).

We have shown that survivin is frequently transcribed and translated in adult B-ALL, but not healthy donor samples, suggesting this may be a promising target patient group for survivin-mediated immunotherapy.

Epithelial-mesenchymal crosstalk induces radioresistance in HNSCC cells

Objective

Epithelial-mesenchymal crosstalk (EMC) contributes to tumor progression, chemoresistance and acquisition of a mesenchymal phenotype (EMT) of cancer cells. This study aims to investigate the effects of EMC on radioresistance in head and neck squamous cell carcinoma (HNSCC) cells.

Methods

In tumor cell lines, the response of HNSCC cells, stimulated with EMC conditioned medium (CM), to irradiation was evaluated with viability and clonogenic assays. Dose modifying factors (DMF) were calculated from the results of clonogenic assays. Potential pathways involved in radioresistance were analyzed with quantitative Real-Time PCR and western blot.

Results

CM significantly reduced the doubling time of SCC-25 cells (from 32.8 hours to 16.8 hours, p=0.0001) and Detroit 562 cells (from 88.5 hours to 29.6 hours, p=0.014). Further it increased clonogenic survival after irradiation. The DMF of CM was 2.04 ± 0.43 (mean ± standard deviation) for SCC-25 cells (p=0.015) and 2.14 ± 0.34 for Detroit 562 cells (p=0.008). Treatment with CM more than tripled the ERCC1 and survivin gene expression in SCC-25 cells.

Conclusion

EMC induced pathways involved in cell survival and DNA repair and led to increased radioresistance in HNSCC cells.

Therapeutic effects of histone deacetylase inhibitors on kidney disease

Increasing evidence has shown the involvement of histone deacetylases (HDACs) in the development and progression of various renal diseases, highlighting its inhibition as a promising therapeutic strategy to prevent kidney diseases. Accordingly, numerous studies have shown that HDAC inhibitors protect the kidneys from various diseases through their effects on multiple pathways, such as suppression of transforming growth factor-β signaling pathway and nuclear factor-κB signaling pathways, augmentation of apoptosis, and inhibition of angiogenesis. To develop more effective and less toxic isoform-selective HDAC inhibitors and further improve clinical outcomes, it is necessary to identify and understand the mechanisms involved in the pathogenesis and progression of renal diseases. This review focuses on the roles of HDAC inhibitors and the mechanisms involved in their therapeutic effects in experimental models of kidney diseases including glomerulosclerosis, tubulointerstitial fibrosis, glomerular and tubulointerstitial inflammation, lupus nephritis, polycystic kidney disease, and renal cell carcinoma (RCC).

Knockdown of microRNA-29a regulates the expression of apoptosis-related genes in MCF-7 breast carcinoma cells

MicroRNA (miR), as non-coding small RNA, are key regulators of cancer-related biological cell processes and contribute to tumor growth through regulation of groups of pro- and anti-apoptotic genes. The present study aimed to investigate the effects of miR-29a on the expression of genes involved in apoptosis, including p21, B-cell lymphoma 2 (BCL-2), p53 and survivin. The MCF-7 breast cancer cell line was transfected with anti-miR-29a and treated with Taxol in subdivided treatment groups including: Scramble; anti-miR-29a; anti-miR-29a + Taxol; Taxol; and control. Expression levels of p21, BCL-2, p53 and survivin were evaluated using reverse transcription-quantitative polymerase chain reaction. miR-29a knockdown resulted in p21 and p53 upregulation and a decrease in survivin expression. These results indicated that miR-29a inhibition regulates apoptosis. The present data suggested that miR-29a inhibition may be a promising strategy for the induction of apoptosis of tumor cells.

Elucidating respective functions of two domains BIR and C-helix of human IAP survivin for precise targeted regulating mitotic cycle, apoptosis and autophagy of cancer cells

Survivin was the smallest member of the IAP family, which was over expressed in many different cancers, and considered to be a promising hot target for cancer therapy, and our previous study demonstrated that multiple dominant negative mutants from full-length survivin could have many complex effects on cancer cells, such as cell cycle, apoptosis, and autophagy. But it was not yet known what role the two main domains played in those functions, which would be very important for the design of targeted anticancer drugs and for the interpretation of their molecular mechanisms. In this study, based on preparation the two parts (BIR domain and CC domain) of survivin by genetic engineering and cell characterization assay, we discovered that BIR (T34A)-domain peptide could inhibit Bcap-37 cells growth in a dose- and time-dependent manner, increase the proportion of G2/M phase, and induce caspase-dependent apoptosis via the mitochondrial pathway. While CC (T117A)-domain peptide increased the proportion of S-phase cells and increased the level of the autophagy marker protein LC3B significantly. These further experiments confirmed that TAT-BIR (T34A) peptide could be used to inhibit cell proliferation, promote apoptosis, and block mitosis, and TAT-CC (T117A) peptide showed mainly to promote autophagy, process of DNA replication, and mitosis to breast cancer cells. This research will lay the foundation for interpreting the multifunction mechanism of survivin in cell fates, further make senses in developing the anticancer drugs targeting it precisely and efficiently.

Tumor cell-targeted delivery of CRISPR/Cas9 by aptamer-functionalized lipopolymer for therapeutic genome editing of VEGFA in osteosarcoma

Osteosarcoma (OS) is a highly aggressive pediatric cancer, characterized by frequent lung metastasis and pathologic bone destruction. Vascular endothelial growth factor A (VEGFA), highly expressed in OS, not only contributes to angiogenesis within the tumor microenvironment via paracrine stimulation of vascular endothelial cells, but also acts as an autocrine survival factor for tumor cell themselves, thus making it a promising therapeutic target for OS. CRISPR/Cas9 is a versatile genome editing technology and holds tremendous promise for cancer treatment. However, a major bottleneck to achieve the therapeutic potential of the CRISPR/Cas9 is the lack of in vivo tumor-targeted delivery systems. Here, we screened an OS cell-specific aptamer (LC09) and developed a LC09-functionalized PEG-PEI-Cholesterol (PPC) lipopolymer encapsulating CRISPR/Cas9 plasmids encoding VEGFA gRNA and Cas9. Our results demonstrated that LC09 facilitated selective distribution of CRISPR/Cas9 in both orthotopic OS and lung metastasis, leading to effective VEGFA genome editing in tumor, decreased VEGFA expression and secretion, inhibited orthotopic OS malignancy and lung metastasis, as well as reduced angiogenesis and bone lesion with no detectable toxicity. The delivery system simultaneously restrained autocrine and paracrine VEGFA signaling in tumor cells and could facilitate translating CRISPR-Cas9 into clinical cancer treatment.

The contemporary role and impact of urine-based biomarkers in bladder cancer

Despite advances in the surgical and medical treatment of bladder cancer, there have only been minor improvements in mortality and morbidity rates over the past decades. Urine-based markers help to improve diagnosing bladder cancer with the aim of complementing or probably in future replacing cystoscopy. Biomarkers may allow individualized risk stratification and support decision-making regarding therapy and follow-up. This review summarizes the existing urine-based biomarkers in bladder cancer. We conducted a comprehensive review of the literature. We conducted a PubMed/Medline based research on English language articles and selected original articles and review articles that provided both description and assessment of urinary markers at time of screening, initial diagnosis, monitoring and prognostic evaluation of urothelial bladder cancer. Our research covered studies published between 2000 and 2017. The aim of this study was to give clinicians keys to understand the existing or promising urinary markers that may become alternatives to cytology/cystoscopy pair in the near future. Many urinary markers are now available, often with superior sensitivity to cytology. Their uses have been evaluated in numerous clinical situations in addition to the time of initial diagnosis and surveillance such as cases of isolated macroscopic hematuria or atypical cytology discordant with the rest of the explorations. However, their superiority over the cytology/cystoscopy association is not demonstrated. These new markers are lacking for the most part of standardization and simplicity making their use in common practice difficult. the types and forms of these new markers are very heterogeneous among themselves and between the studies that evaluate them. Well-designed protocols and prospective, controlled trials are needed to provide the basis to determine whether integration of urine- and blood-based biomarkers into clinical decision-making will be of value for bladder cancer detection and screening in the future.

Honokiol Radiosensitizes Squamous Cell Carcinoma of the Head and Neck by Downregulation of Survivin

Purpose: Previous studies revealed diverging results regarding the role of survivin in squamous cell carcinoma of the head and neck (SCCHN). This study aimed to evaluate the clinical significance of survivin expression in SCCHN; the function of survivin in DNA-damage repair following ionizing radiation therapy (RT) in SCCHN cells; and the potential of honokiol to enhance RT through downregulation of survivin.Experimental Design: Expression of survivin in SCCHN patient primary tumor tissues (n = 100) was analyzed and correlated with clinical parameters. SCCHN cell lines were used to evaluate the function of survivin and the effects of honokiol on survivin expression in vitro and in vivoResults: Overexpression of survivin was significantly associated with lymph nodes' metastatic status (P = 0.025), worse overall survival (OS), and disease-free survival (DFS) in patients receiving RT (n = 65, OS: P = 0.024, DFS: P = 0.006) and in all patients with SCCHN (n = 100, OS: P = 0.002, DFS: P = 0.003). In SCCHN cells, depletion of survivin led to increased DNA damage and cell death following RT, whereas overexpression of survivin increased clonogenic survival. RT induced nuclear accumulation of survivin and its molecular interaction with γ-H2AX and DNA-PKCs. Survivin specifically bound to DNA DSB sites induced by I-SceI endonuclease. Honokiol (which downregulates survivin expression) in combination with RT significantly augmented cytotoxicity in SCCHN cells with acquired radioresistance and inhibited growth in SCCHN xenograft tumors.Conclusions: Survivin is a negative prognostic factor and is involved in DNA-damage repair induced by RT. Targeting survivin using honokiol in combination with RT may provide novel therapeutic opportunities. Clin Cancer Res; 24(4); 858-69. ©2017 AACR.