Survivin: a new target for anti-cancer therapy

Survivin mRNA expression in blood as a predictor of the response to EGFR-tyrosine kinase inhibitors and prognosis in patients with non-small cell lung cancer

The epidermal growth factor receptor (EGFR) mutations have been proven to be a reliable predictive marker for the response to EGFR-tyrosine kinase inhibitors (TKIs) in patients with non-small cell lung cancer (NSCLC). However, the responses to EGFR-TKIs vary even among patients with EGFR mutation. Recent study showed that survivin overexpression attenuated EGFR-TKI-induced apoptosis and inhibited the antitumor effect of EGFR-TKIs on EGFR mutation NSCLC cells. We investigated the role of survivin mRNA expression in peripheral blood on predicting response and prognosis in NSCLC patients treated with EGFR-TKIs. Survivin mRNA expression levels in blood was detected using quantitative real-time-PCR assay in 62 patients with advanced NSCLC before (D0) and 4 weeks after treatment of EGFR-TKIs (D4w). The associations between survivin mRNA expression in blood and tumor response to treatment, time to progression (TTP), and overall survival (OS) were analyzed. Blood survivin mRNA levels at D0 and D4w were significantly higher in patients with progressive disease than in those with partial response and stable disease. The detections of blood survivin mRNA positivity at D0 and D4w were associated with unfavorable response to EGFR-TKIs treatment and shorter TTP and OS. Multivariate Cox analysis showed that blood survivin mRNA positivity before and 4 weeks after EGFR-TKIs treatment were independent predictor for worse TTP and OS. In conclusion, Blood survivin mRNA positivity was strongly related to a poor treatment outcome of EGFR-TKIs and may be a potential non-invasive biomarker for NSCLC treatment.

Survivin beyond physiology: orchestration of multistep carcinogenesis and therapeutic potentials

Survivin, a member of the inhibitor of apoptosis protein family, has been associated with protection from cell apoptosis and regulation of mitosis. Survivin exhibits low to undetectable expression in most finally differentiated adult tissues but is abundantly over-expressed in almost all cancers. The aberrant high expression of survivin in cancers is associated with advanced disease, increased rate of tumor recurrence, abbreviated overall survival and resistance to chemo- and radio- therapy. Survivin touches nearly every aspect of cancer and is involved in the initiation, maintenance and development of tumor. Therefore, its significance in cancer dictates the pursuit for anti-survivin cancer therapies.

The effects of STAT3 and Survivin silencing on the growth of human bladder carcinoma cells

Despite accumulating evidence suggesting a critical role of signal transducer and activator of transcription 3 (STAT3) and Survivin in human bladder cancer, the effects of silencing these genes on the proliferation of T24 bladder carcinoma cells remain unknown. Here, we investigated the inhibitory effects of STAT3 or Survivin silencing on the in vitro and in vivo growth of human T24 bladder carcinoma cells. Small interfering RNA (siRNA) vectors targeting STAT3, Survivin, or both genes were designed and synthesized. The recombinant plasmid DNA constructs were confirmed by DNA sequencing. They were then transiently transfected into T24 cells, and the mRNA and protein expressions of STAT3 and Survivin were determined using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot, respectively. Cell proliferation was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The in vivo growth-inhibition effects of the siRNA vectors were assessed using a bladder cancer mouse model. The tumor weight and size was recorded 4 weeks post-inoculation. We successfully synthesized four siRNA vectors targeting STAT3 and four vectors targeting Survivin. The STAT3-3 and Survivin-4 siRNA constructs were most efficient in reducing STAT3 or Survivin expression, respectively. We then constructed a vector containing these two sequences together (STAT3-Survivin siRNA) and found that the single vector efficiently silenced STAT3 and Survivin expression. Moreover, silencing of STAT3 or Survivin significantly suppressed the in vitro and in vivo proliferation of T24 cells compared to the controls (P<0.05). Our findings indicated that the downregulation of STAT3 or Survivin can suppress the proliferation of T24 bladder cancer cells. Moreover, no additive effects were observed when STAT3 and Survivin were knocked down together, suggesting that they work in the same signaling pathway in T24 cells. These results provide valuable insights into understanding the pathways involved during the tumorigenesis of bladder cancer.

Survivin and YM155: how faithful is the liaison?

Survivin belongs to the family of apoptosis inhibitors (IAPs), which antagonizes the induction of cell death. Dysregulated expression of IAPs is frequently observed in cancers, and the high levels of survivin in tumors compared to normal adult tissues make it an attractive target for pharmacological interventions. The small imidazolium-based compound YM155 has recently been reported to block the expression of survivin via inhibition of the survivin promoter. Recent data, however, question that this is the sole and main effect of this drug, which is already being tested in ongoing clinical studies. Here, we critically review the current data on YM155 and other new experimental agents supposed to antagonize survivin. We summarize how cells from various tumor entities and with differential expression of the tumor suppressor p53 respond to this agent in vitro and as murine xenografts. Additionally, we recapitulate clinical trials conducted with YM155. Our article further considers the potency of YM155 in combination with other anti-cancer agents and epigenetic modulators. We also assess state-of-the-art data on the sometimes very promiscuous molecular mechanisms affected by YM155 in cancer cells.

IAP family of cell death and signaling regulators

Inhibitor of apoptosis (IAP) proteins interface with, and regulate a large number of, cell signaling pathways. If there is a common theme to these pathways, it is that they are involved in the development of the immune system, immune responses, and unsurprisingly, given their name, cell death. Beyond that it is difficult to discover an underlying logic because sometimes IAPs are required to inhibit or prevent signaling, whereas in other cases they are required for signaling to take place. In whatever role they play, they are recruited into signaling complexes and function as ubiquitin E3 ligases, via their RING domains. This review discusses IAP regulation of signaling pathways and focuses on the mammalian IAPs, XIAP, c-IAP1, and c-IAP2, with a particular emphasis on techniques and methods that were used to uncover their roles. We also provide a perspective on targeting IAP proteins for therapeutic intervention and methods used to define the clinical relevance of IAP proteins.

Survivin gene expression increases gastric cancer cell lymphatic metastasis by upregulating vascular endothelial growth factor-C expression levels

The aim of this study was to investigate the correlation between the expression of survivin and vascular endothelial growth factor‑C (VEGF‑C) in gastric cancer and the pathway by which survivin may affect gastric cancer lymphatic metastasis. The study may provide novel targets for treating gastric cancer lymphatic metastasis and distal dissemination. Survivin and VEGF‑C expression in gastric carcinoma and peri‑carcinoma (2 cm away from the carcinoma) tissues, obtained from 195 patients who underwent curative gastrectomy surgery (130 cases presented with lymph node metastasis and 65 cases presented without metastasis), was examined immunohistochemically using a tissue microarray. Plasmids containing survivin and VEGF‑C shRNA were constructed and transfected into SGC‑7901 gastric cancer cells. The expression levels of the two genes were examined using western blot analysis and qPCR, and the results were statistically analyzed. The expression levels of survivin and VEGF‑C were 51.3 and 55.4%, respectively, in gastric carcinoma. Survivin and VEGF‑C were located mainly in the cytoplasm of the tumor cells. The expression levels of survivin and VEGF‑C were significantly higher in patients with lymph node metastasis than in those without metastasis (P=0.008 and 0.001, respectively). Patients with high expression levels of survivin and VEGF‑C showed significantly less favorable survival rates compared with patients with low expression levels of those two genes (P=0.003 and 0.039, respectively). Moreover, patients with co‑expression of the two genes usually had a poorer prognosis (P=0.003). However, multivariate analysis demonstrated that neither of the two genes were an independent prognostic determinant. The levels of VEGF‑C expression may be regulated by survivin expression. Conversely, inhibiting VEGF‑C gene expression by shRNA did not reduce survivin expression at the mRNA or protein levels. Survivin and VEGF‑C were expressed in gastric cancer cells and were significantly associated with lymphatic metastasis. Survivin may be a regulator of VEGF‑C expression in gastric cancer cells, and is essential in invasion and lymphatic metastasis. Moreover, survivin may be able to serve as a chemotherapy target for gastric cancer.

Prognostic value of a nine-gene signature in glioma patients based on mRNA expression profiling

INTRODUCTION

Gliomas are the most common primary brain tumors in adults and a significant cause of cancer-related mortality. A 9-gene signature was identified as a novel prognostic model reflecting survival situation obviously in gliomas.

AIMS

To identify an mRNA expression signature to improve outcome prediction for patients with different glioma grades.

RESULTS

We used whole-genome mRNA expression microarray data of 220 glioma samples of all grades from the Chinese Glioma Genome Atlas (CGGA) database (http://www.cgga.org.cn) as a discovery set and data from Rembrandt and GSE16011 for validation sets. Data from every single grade were analyzed by the Kaplan-Meier method with a two-sided log-rank test. Univariate Cox regression and linear risk score formula were applied to derive a gene signature with better prognostic performance. We found that patients who had high risk score according to the signature had poor overall survival compared with patients who had low risk score. Highly expressed genes in the high-risk group were analyzed by gene ontology (GO) and gene set variation analysis (GSVA). As a result, the reason for the divisibility of gliomas was likely due to cell life processes and adhesion.

CONCLUSION

This 9-gene-signature prediction model provided a more accurate predictor of prognosis that denoted patients with high risk score have poor outcome. Moreover, these risk models based on defined molecular profiles showed the considerable prospect in personalized cancer management.

Regulation of angiogenesis via Notch signaling in breast cancer and cancer stem cells

Breast cancer angiogenesis is elicited and regulated by a number of factors including the Notch signaling. Notch receptors and ligands are expressed in breast cancer cells as well as in the stromal compartment and have been implicated in carcinogenesis. Signals exchanged between neighboring cells through the Notch pathway can amplify and consolidate molecular differences, which eventually dictate cell fates. Notch signaling and its crosstalk with many signaling pathways play an important role in breast cancer cell growth, migration, invasion, metastasis and angiogenesis, as well as cancer stem cell (CSC) self-renewal. Therefore, significant attention has been paid in recent years toward the development of clinically useful antagonists of Notch signaling. Better understanding of the structure, function and regulation of Notch intracellular signaling pathways, as well as its complex crosstalk with other oncogenic signals in breast cancer cells will be essential to ensure rational design and application of new combinatory therapeutic strategies. Novel opportunities have emerged from the discovery of Notch crosstalk with inflammatory and angiogenic cytokines and their links to CSCs. Combinatory treatments with drugs designed to prevent Notch oncogenic signal crosstalk may be advantageous over λ secretase inhibitors (GSIs) alone. In this review, we focus on the more recent advancements in our knowledge of aberrant Notch signaling contributing to breast cancer angiogenesis, as well as its crosstalk with other factors contributing to angiogenesis and CSCs.

Arsenic trioxide induces apoptosis in B-cell chronic lymphocytic leukemic cells through down-regulation of survivin via the p53-dependent signaling pathway

Arsenic trioxide (As2O3) can induce apoptosis in many tumors. However, the associated mechanisms are not clearly understood. We found that As2O3 significantly inhibited the proliferation of WSU-CLL cells and induced apoptosis in dose- and time-dependent manners. WSU-CLL cells treated with 2μM As2O3 showed survivin down-regulation and p53 up-regulation. Survivin siRNA combined with As2O3 further inhibited the proliferation of WSU-CLL cells. p53 inhibition by siRNA prevented the down-regulation of survivin by As2O3 and prevented the As2O3-induced cytotoxicity of WSU-CLL cells. These results suggest that As2O3 may be of therapeutic value for chronic lymphocytic leukemia.

Rational design of multifunctional upconversion nanocrystals/polymer nanocomposites for cisplatin (IV) delivery and biomedical imaging

By combining upconversion nanoparticles with the cisplatin (IV) prodrug we have demonstrated that a stable and multifunctional drug delivery system can be designed that will both reduce the drawbacks of cisplatin and give insight in to its in vitro/in vivo imaging. The up/down-conversion fluorescence are detectable and show obvious co-localization, demonstrating that the nanoparticles are rather stable inside cells and retain the UCNPs and block copolymer.

Overcoming IGF1R/IR resistance through inhibition of MEK signaling in colorectal cancer models

PURPOSE

Results from clinical trials involving resistance to molecularly targeted therapies have revealed the importance of rational single-agent and combination treatment strategies. In this study, we tested the efficacy of a type 1 insulin-like growth factor receptor (IGF1R)/insulin receptor (IR) tyrosine kinase inhibitor, OSI-906, in combination with a mitogen-activated protein (MAP)-ERK kinase (MEK) 1/2 inhibitor based on evidence that the MAP kinase pathway was upregulated in colorectal cancer cell lines that were resistant to OSI-906.

EXPERIMENTAL DESIGN

The antiproliferative effects of OSI-906 and the MEK 1/2 inhibitor U0126 were analyzed both as single agents and in combination in 13 colorectal cancer cell lines in vitro. Apoptosis, downstream effector proteins, and cell cycle were also assessed. In addition, the efficacy of OSI-906 combined with the MEK 1/2 inhibitor selumetinib (AZD6244, ARRY-142886) was evaluated in vivo using human colorectal cancer xenograft models.

RESULTS

The combination of OSI-906 and U0126 resulted in synergistic effects in 11 of 13 colorectal cancer cell lines tested. This synergy was variably associated with apoptosis or cell-cycle arrest in addition to molecular effects on prosurvival pathways. The synergy was also reflected in the in vivo xenograft studies following treatment with the combination of OSI-906 and selumetinib.

CONCLUSIONS

Results from this study demonstrate synergistic antiproliferative effects in response to the combination of OSI-906 with an MEK 1/2 inhibitor in colorectal cancer cell line models both in vitro and in vivo, which supports the rational combination of OSI-906 with an MEK inhibitor in patients with colorectal cancer. Clin Cancer Res; 19(22); 6219-29. ©2013 AACR.

Down-Regulation of Survivin by Nemadipine-A Sensitizes Cancer Cells to TRAIL-Induced Apoptosis

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor family of cytokines. TRAIL selectively induces apoptotic cell death in various tumors and cancer cells, but it has little or no toxicity in normal cells. Agonism of TRAIL receptors has been considered to be a valuable cancer-therapeutic strategy. However, more than 85% of primary tumors are resistant to TRAIL, emphasizing the importance of investigating how to overcome TRAIL resistance. In this report, we have found that nemadipine-A, a cell-permeable L-type calcium channel inhibitor, sensitizes TRAIL-resistant cancer cells to this ligand. Combination treatments using TRAIL with nemadipine-A synergistically induced both the caspase cascade and apoptotic cell death, which were blocked by a pan caspase inhibitor (zVAD) but not by autophagy or a necrosis inhibitor. We further found that nemadipine-A, either alone or in combination with TRAIL, notably reduced the expression of survivin, an inhibitor of the apoptosis protein (IAP) family of proteins. Depletion of survivin by small RNA interference (siRNA) resulted in increased cell death and caspase activation by TRAIL treatment. These results suggest that nemadipine-A potentiates TRAIL-induced apoptosis by down-regulation of survivin expression in TRAIL resistant cells. Thus, combination of TRAIL with nemadipine-A may serve a new therapeutic scheme for the treatment of TRAIL resistant cancer cells, suggesting that a detailed study of this combination would be useful.

Inhibition of gastric cancer cell growth in vivo by overexpression of adeno-associated virus-mediated survivin mutant C84A

Survivin is overexpressed in most of human cancer cells and tissues. Its overexpression is associated with apoptosis inhibition, drug resistance, and poor prognosis. In this study, we investigated the effect of adeno-associated virus (AAV)-mediated survivin mutant Cys84Ala [rAAV-Sur-Mut(C84A)] on gastric cancer growth. Sur-Mut(C84A) was subcloned into the AAV expression vector pAM/CAG to generate recombinant (r)AAV-Sur-Mut(C84A) virus. Cell survival was determined by the MTT method. Apoptosis was measured by FACS analysis and TUNEL. Tumor growth was assessed using a xenograft mouse model. Results showed that treatment of rAAV-Sur-Mut(C84A) virus significantly reduced cell survival, induced apoptosis, and sensitized gastric cancer cells to 5-fluorouracil in vitro. Furthermore, treatment of rAAV-Sur-Mut(C84A) virus markedly induced apoptosis and inhibited gastric cancer growth in vivo. Moreover, rAAV-Sur-Mut(C84A) treatment strongly enhanced the antitumor activity of 5-fluorouracil. Our results suggest that the combination of rAAV-Sur-Mut(C84A) with chemotherapy may be a promising strategy for gastric cancer therapy.

Effects of quercetin on the proliferation of breast cancer cells and expression of survivin in vitro

Quercetin is a hydrophobic agent with potential anticancer activity. The aim of the present study was to observe the effects of quercetin on the proliferation of the breast cancer cell line MCF-7 and the gene expression of survivin. The molecular mechanism underlying the antiproliferative effect of quercetin was also investigated. MCF-7 breast cancer cells were treated with various concentrations of quercetin. The inhibitory effect of quercetin on proliferation was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and the inhibition rate was calculated. Cellular apoptosis was detected by immunocytochemistry and survivin mRNA expression levels were observed using reverse transcription-polymerase chain reaction (RT-PCR). Western blot analysis was used to analyze changes in the expression levels of survivin protein. Quercetin induced the apoptosis of MCF-7 cells and inhibited the proliferation of the MCF-7 breast cancer cells in a time- and concentration-dependent manner. The mRNA and protein expression levels of survivin were reduced as the concentration of quercetin increased. Quercetin inhibited the growth of MCF-7 cells and promoted apoptosis by inducing G0/ G1 phase arrest. It also regulated the expression of survivin mRNA in MCF-7 cells, which may be the mechanism underlying its antitumor effect.

Withanone as an inhibitor of survivin: a potential drug candidate for cancer therapy

Survivin, the smallest inhibitor of apoptosis protein, which has been reported to be highly expressed in almost all known cancers, plays a dual role in survival as well as the proliferation of cancer cells. It inhibits apoptosis by inhibiting caspases as well as facilitating mitosis by becoming a part of chromosomal passenger complex through its BIR5 domain. Docking studies carried out with herbal ligand withanone derived from roots of Withania somnifera have shown strong binding affinity of -19.1088 kJ/mol with BIR5 domain of survivin and in turn interferes with inhibitory action against caspases and may lead to apoptosis. Binding of withanone at BIR5 domain of survivin may also interfere with chromosomal passenger complex and lead to halt the mitotic process within the cancer cell. Docking studies support various experimental outcomes and suggest withanone as a potential candidate molecule in cancer therapy.

Multifunctional nanocarrier based on clay nanotubes for efficient intracellular siRNA delivery and gene silencing

RNA interference-mediated gene silencing relating to disease has recently emerged as a powerful method in gene therapy. Despite the promises, effective transport of siRNA with minimal side effects remains a challenge. Halloysites are cheap and naturally available aluminosilicate clay nanotubes with high mechanical strength and biocompatibility. In this study, a novel multifunctional nanocarrier based on functionalized halloysite nanotubes (f-HNTs) has been developed via electrostatic layer-by-layer assembling approach for loading and intracellular delivery of therapeutic antisurvivin siRNA and simultaneously tracking their intracellular transport, in which PEI-modified HNTs are used as gene vector, antisurvivin siRNA as gene therapeutic agent, and mercaptoacetic acid-capped CdSe quantum dots as fluorescent labeling probes. The successful assembly of the f-HNTs-siRNA complexes was systematically characterized by transmission electron microscopy (TEM), UV-visible spectrophotometry, Zeta potential measurement, fluorescence spectrophotometry, and electrochemical impedance spectroscopy. Confocal microscopy, biological TEM, and flow cytometry studies revealed that the complexes enabled the efficient intracellular delivery of siRNA for cell-specific gene silencing. MTT assays exhibited that the complexes can enhance antitumor activity. Furthermore, Western blot analysis showed that f-HNTs-mediated siRNA delivery effectively knocked down gene expression of survivin and thereby decreased the levels of target proteins of PANC-1 cells. Therefore, this study suggested that the synthesized f-HNTs were a new effective drug delivery system for potential application in cancer gene therapy.

Exploring the role of post-translational modifications on protein-protein interactions with survivin

Survivin is a member of the inhibitor of apoptosis protein (IAP) family with crucial roles in apoptosis and cell cycle regulation. Post-translational modifications (PTMs) have a ubiquitous role in the regulation of a diverse range of proteins' cellular functions and survivin is not an exception. Phosphorylation, acetylation and ubiquitination seem to regulate survivin anti-apoptotic and mitotic roles and also its nuclear localization. In the present review we explore the role of PTMs on protein-protein interactions focused on survivin to provide new insights into the functions and cell localization of this IAP in pathophysiological conditions, which might help the envisioning of novel targeted therapies for diseases characterized by impaired survivin activity. Protein-protein interaction analysis was performed with bioinformatics tools based on published data aiming to give an integrated perspective of this IAP's role in the cell.

Design, synthesis and biological studies of survivin dimerization modulators that prolong mitotic cycle

Survivin, a member of the inhibitor of apoptosis protein (IAP) family proteins, has essential roles in cell division and inhibition of apoptosis. Several clinical studies in cancer patients have shown that the elevated levels of survivin correlate with aggressiveness of the disease and resistance to radiation and chemotherapeutic treatments. Survivin is an integral component of chromosomal passenger complex (CPC) where it binds to borealin and INCENP through its dimerization interface. Thus, disruption of functional survivin along its dimer interface with a small molecule is hypothesized to inhibit the proliferation of cancer cells and sensitize them to therapeutic agents and radiation. Recently, a small molecule (Abbott8) was reported to bind at the dimerization interface of survivin. Further development of this compound was accomplished by computational modeling of the molecular interactions along the dimerization interface, which has led to the design of promising survivin dimerization modulators. Two of the most potent survivin modulators, LLP3 and LLP9 at concentrations between 50 and 100nM, caused delay in mitotic progression and major mitotic defects in proliferating human umbilical vein endothelial cells (HUVEC) and prostate cancer cells (PC3).

RecQL4 helicase amplification is involved in human breast tumorigenesis

Breast cancer occur both in hereditary and sporadic forms, and the later one comprises an overwhelming majority of breast cancer cases among women. Numerical and structural alterations involving chromosome 8, with loss of short arm (8p) and gain of long arm (8q), are frequently observed in breast cancer cells and tissues. In this study, we show that most of the human breast tumor cell lines examined display an over representation of 8q24, a chromosomal locus RecQL4 is regionally mapped to, and consequently, a markedly elevated level of RecQL4 expression. An increased RecQL4 mRNA level was also observed in a majority of clinical breast tumor samples (38/43) examined. shRNA-mediated RecQL4 suppression in MDA-MB453 breast cancer cells not only significantly inhibit the in vitro clonogenic survival and in vivo tumorigenicity. Further studies demonstrate that RecQL4 physically interacts with a major survival factor-survivin and its protein level affects survivin expression. Although loss of RecQL4 function due to gene mutations causally linked to occurrence of human RTS with features of premature aging and cancer predisposition, our studies provide the evidence that overexpression of RecQL4 due to gene amplification play a critical role in human breast tumor progression.

Enhanced inhibition of bladder cancer cell growth by simultaneous knockdown of antiapoptotic Bcl-xL and survivin in combination with chemotherapy

The overexpression of antiapoptotic genes, such as Bcl-xL and survivin, contributes to the increased survival of tumor cells and to the development of treatment resistances. In the bladder cancer cell lines EJ28 and J82, the siRNA-mediated knockdown of survivin reduces cell proliferation and the inhibition of Bcl-xL sensitizes these cells towards subsequent chemotherapy with mitomycin C and cisplatin. Therefore, the aim of this study was to analyze if the simultaneous knockdown of Bcl-xL and survivin might represent a more powerful treatment option for bladder cancer than the single inhibition of one of these target genes. At 96 h after transfection, reduction in cell viability was stronger after simultaneous inhibition of Bcl-xL and survivin (decrease of 40%-48%) in comparison to the single target treatments (decrease of 29% at best). Furthermore, simultaneous knockdown of Bcl-xL and survivin considerably increased the efficacy of subsequent chemotherapy. For example, cellular viability of EJ28 cells decreased to 6% in consequence of Bcl-xL and survivin inhibition plus cisplatin treatment whereas single target siRNA plus chemotherapy treatments mediated reductions down to 15%-36% only. In conclusion, the combination of simultaneous siRNA-mediated knockdown of antiapoptotic Bcl-xL and survivin-a multitarget molecular-based therapy-and conventional chemotherapy shows great potential for improving bladder cancer treatment.

Differences in gene expression profiles and carcinogenesis pathways involved in cisplatin resistance of four types of cancer

Cisplatin-based chemotherapy is the standard therapy used for the treatment of several types of cancer. However, its efficacy is largely limited by the acquired drug resistance. To date, little is known about the RNA expression changes in cisplatin-resistant cancers. Identification of the RNAs related to cisplatin resistance may provide specific insight into cancer therapy. In the present study, expression profiling of 7 cancer cell lines was performed using oligonucleotide microarray analysis data obtained from the GEO database. Bioinformatic analyses such as the Gene Ontology (GO) and KEGG pathway were used to identify genes and pathways specifically associated with cisplatin resistance. A signal transduction network was established to identify the core genes in regulating cancer cell cisplatin resistance. A number of genes were differentially expressed in 7 groups of cancer cell lines. They mainly participated in 85 GO terms and 11 pathways in common. All differential gene interactions in the Signal-Net were analyzed. CTNNB1, PLCG2 and SRC were the most significantly altered. With the use of bioinformatics, large amounts of data in microarrays were retrieved and analyzed by means of thorough experimental planning, scientific statistical analysis and collection of complete data on cancer cell cisplatin resistance. In the present study, a novel differential gene expression pattern was constructed and further study will provide new targets for the diagnosis and mechanisms of cancer cisplatin resistance.

Systemic delivery of sticky siRNAs targeting the cell cycle for lung tumor metastasis inhibition

RNA interference allows the design of new inhibitors that target deregulated pathways in cancer. However systemic delivery of siRNA for the treatment of solid tumors still remains an issue. In our study, in order to suppress the progression of lung cancer metastasis in mice, we developed sticky siRNA (ssiRNA) to inhibit survivin and cyclin B1, two candidates involved in cell survival and proliferation. We exploited the linear polyethylenimine (PEI) as potent non-viral carrier to efficiently deliver our inhibitors. As a proof of concept, we have chosen a very aggressive mammary adenocarcinoma model (TSA-Luc cells), which forms lung metastases upon systemic cell injection. We confirmed in vitro, that the ssiRNAs delivered with PEI are not only able to inhibit our target genes at the mRNA and protein levels, but are also able to block the cell cycle and cell proliferation through a mechanism of RNA interference. More importantly, we showed in vivo by luciferase dosage, bioimaging and tissue section, an inhibition of lung tumor metastases after systemic delivery of cyclin B1 and survivin ssiRNA complexed with PEI. Alternating treatment with cisplatin and ssiRNA/PEI showed an additive effect between the two anticancer drugs on lung tumor inhibition leading to a significant increase in animal survival. Moreover a promising window between activity (IC₅₀) and toxicity (LD₅₀), essential for therapeutic application, was observed. Our data show that systemic delivery of ssiRNA/PEI complexes targeting the cell cycle is a valuable strategy for the treatment of lung tumor metastasis and that it can be combined with chemotherapy.

Early gene expression changes by Epstein-Barr virus infection of B-cells indicate CDKs and survivin as therapeutic targets for post-transplant lymphoproliferative diseases

Lymphoproliferative diseases (LPDs) associated with Epstein-Barr virus (EBV) infection cause significant morbidity and mortality in bone marrow and solid organ transplant recipients. To gain insight into LPD pathogenesis and to identify potential effective therapeutic approaches, we investigated early molecular events leading to B-cell transformation by gene expression profiling of EBV-infected B-cells from tonsils by Affymetrix microarray 72 hr postinfection when the B-cells hyperproliferation phase starts. Cell cycle and apoptosis were the most significantly affected pathways and enriched gene sets. In particular, we found significantly increased expression of cyclin-dependent kinase (CDK)1 and CCNB1 (cyclin B1) and of one of their downstream targets BIRC5 (survivin). Importantly, the strong upregulation of the antiapoptotic protein survivin was confirmed in lymphoblastoid cell lines (LCLs) and 71% of EBV-positive post-transplant EBV-LPD lesions scored positive for survivin. The validity of early transforming events for the identification of therapeutic targets for EBV-LPD was confirmed by the marked antiproliferative effect of the CDK inhibitor flavopiridol on LCLs and by the strong induction of apoptosis by survivin inhibition with YM155 or terameprocol. Our results suggest that targeting of CDKs and/or survivin in post-transplant EBV-LPD by specific inhibitors might be an important approach to control and eliminate EBV-transformed B-cells that should be further considered.

Loss of Survivin influences liver regeneration and is associated with impaired Aurora B function

The chromosomal passenger complex (CPC) acts as a key regulator of mitosis, preventing asymmetric segregation of chromosomal material into daughter cells. The CPC is composed of three non-enzymatic components termed Survivin, the inner centromere protein (INCENP) and Borealin, and an enzymatic component, Aurora B kinase. Survivin is necessary for the appropriate separation of sister chromatids during mitosis and is involved in liver regeneration, but its role in regenerative processes is incompletely elucidated. Whether Survivin, which is classified as an inhibitor of apoptosis protein (IAP) based on domain composition, also has a role in apoptosis is controversial. The present study examined the in vivo effects of Survivin ablation in the liver and during liver regeneration after 70% hepatectomy in a hepatocyte-specific knockout mouse model. The absence of Survivin caused a reduction in the number of hepatocytes in the liver, together with an increase in cell volume, macronucleation and polyploidy, but no changes in apoptosis. During liver regeneration, mitosis of hepatocytes was associated with mislocalization of the members of the CPC, which were no longer detectable at the centromere despite an unchanged protein amount. Furthermore, the loss of survivin in regenerating hepatocytes was associated with reduced levels of phosphorylated Histone H3 at serine 28 and abolished phosphorylation of CENP-A and Hec1 at serine 55, which is a consequence of decreased Aurora B kinase activity. These data indicate that Survivin expression determines hepatocyte number during liver development and liver regeneration. Lack of Survivin causes mislocalization of the CPC members in combination with reduced Aurora B activity, leading to impaired phosphorylation of its centromeric target proteins and inappropriate cytokinesis.

Antiviral and antitumor T-cell immunity in patients treated with GM-CSF-coding oncolytic adenovirus

PURPOSE

Multiple injections of oncolytic adenovirus could enhance immunologic response. In the first part of this article, the focus was on immunologic aspects. Sixty patients previously naïve to oncolytic virus and who had white blood cells available were treated. Thirty-nine of 60 were assessed after a single virus administration, whereas 21 of 60 received a "serial treatment" consisting of three injections within 10 weeks. In the second part, we focused on 115 patients treated with a granulocyte macrophage colony-stimulating factor (GM-CSF)-coding capsid chimeric adenovirus, CGTG-102.

RESULTS

Following serial treatment, both increase and decrease in antitumor T cells in blood were seen more frequently, findings which are compatible with induction of T-cell immunity and trafficking of T cells to tumors, respectively. Safety was good in both groups. In 115 patients treated with CGTG-102 (Ad5/3-D24-GMCSF), median overall survival was 111 days following single and 277 days after serial treatment in nonrandomized comparison. Switching the virus capsid for avoiding neutralizing antibodies in a serial treatment featuring three different viruses did not impact safety or efficacy. A correlation between antiviral and antitumor T cells was seen (P = 0.001), suggesting that viral oncolysis can result in epitope spreading and breaking of tumor-associated immunologic tolerance. Alternatively, some patients may be more susceptible to induction of T-cell immunity and/or trafficking.

CONCLUSIONS

These results provide the first human data linking antiviral immunity with antitumor immunity, implying that oncolytic viruses could have an important role in cancer immunotherapy.

Prognostic value of proliferation markers expression in breast cancer

In this study, immunohistochemical expression of five proliferation markers: Ki-67, aurora-A kinase, survivin, B-Myb and cyclin B1, was analyzed. Consecutive 215 tumor samples from breast cancer patients operated from 2002 to 2003 were analyzed using the TMA ("tissue microarray") method. The median follow-up was 95 months (from 7.8 to 107 months). Statistically significant correlations between expression levels in five proliferation markers, and correlations between some of the proliferation markers and traditional prognostic factors were found. Statistically significant prognostic influence of aurora-A kinase, survivin and B-Myb expression levels on overall and disease-free survival was found, and cyclin B1 expression level on disease-free survival. A multivariate analysis confirmed survivin and B-Myb expression as independent prognostic factors of overall (p = 0.0195; p = 0.0004) and disease-free survival (p = 0.0107 and p = 0.0205) in breast cancer patients.

OCT4 increases BIRC5 and CCND1 expression and promotes cancer progression in hepatocellular carcinoma

Background

OCT4 and BIRC5 are preferentially expressed in human cancer cells and mediate cancer cell survival and tumor maintenance. However, the molecular mechanism that regulates OCT4 and BIRC5 expression is not well characterized.

Methods

By manipulating OCT4 and BIRC5 expression in hepatocellular carcinoma (HCC) cell lines, the regulatory mechanism of OCT4 on BIRC5 and CCND1 were investigated.

Results

Increasing or decreasing OCT4 expression could enhance or suppress BIRC5 expression, respectively, by regulating the activity of BIRC5 promoter. Because there is no binding site for OCT4 within BIRC5 promoter, the effect of OCT4 on BIRC5 promoter is indirect. An octamer motif for OCT4 in the CCND1 promoter has directly and partly participated in the regulation of CCND1 promoter activity, suggesting that OCT4 also could upregulated the expression of CCND1. Co-suppression of OCT4 and BIRC5 induced cancer cell apoptosis and cell cycle arrest, thereby efficiently inhibiting the proliferative activity of cancer cells and suppressing the growth of HCC xenogrfts in nude mice.

Conclusion

OCT4 can upregulate BIRC5 and CCND1 expression by increasing their promoter activity. These factors collusively promotes HCC cell proliferation, and co-suppression of OCT4 and BIRC5 is potentially beneficial for HCC treatment.

Suicide gene therapy for hepatocellular carcinoma cells by survivin promoter-driven expression of the herpes simplex virus thymidine kinase gene

The aim of this study was to investigate the selective killing effect of the herpes simplex virus-thymidine kinase/ganciclovir (TK/GCV) suicide gene system controlled by the survivin promoter on hepatocellular carcinoma (HCC) cells in vitro. Recombinant plasmid vectors driven by the survivin promoter were constructed. HepG2 HCC and LO2 normal human liver cells were transfected with the recombinant plasmids, green fluorescent protein (GFP)/pSURV, TK/pSURV and TAT-TK/pSURV. GFP expression was detected by fluoroscopy and flow cytometry (FCM). TK gene expression was detected using RT-PCR and western blot analysis. The selective killing effects after GCV application were evaluated by tetrazolium assay, FCM and western blot analysis. Statistical analysis was performed by ANOVA. After transfection with GFP/pSURV, TK/pSURV and TAT-TK/pSURV for 48 h, GFP expression was observed in the HepG2 cells, but not in the L02 cells and TK gene expression was evidently detected by RT-PCR and western blot analysis in the HepG2 cells. Three stably transfected cell lines (HepG2/pSURV, HepG2/TK/pSURV and HepG2/TAT-TK/pSURV) were successfully established. Compared with the HepG2/TK/pSURV group, a significant ‘bystander effect’ was observed in the HepG2/TAT-TK/pSURV group with the incorporation of unmodifed HepG2 cells at different ratios. Following transfection with TK/pSURV and TAT-TK/pSURV, the growth of HepG2 cells in the presence of GCV was markedly inhibited. This finding was further corroborated by FCM and immunoblot analysis revealed the repressed expression of proliferating cell nuclear antigen (PCNA). Our results showed that the plasmid vectors carrying the TK and TAT-TK fusion protein gene driven by the survivin promoter were successfully constructed and their specific expression in HepG2 cells provided the basis for the targeted gene therapy of HCC.

Markedly additive antitumor activity with the combination of a selective survivin suppressant YM155 and alemtuzumab in adult T-cell leukemia

Adult T-cell leukemia (ATL) is an aggressive malignancy of CD4(+)CD25(+) lymphocytes caused by human T-cell lymphotropic virus type 1. Currently, there is no accepted curative therapy for ATL. In gene expression profiling, the antiapoptotic protein survivin (BIRC5) demonstrated a striking increase in ATL, and its expression was increased in patient ATL cells resistant to the anti-CD52 monoclonal antibody alemtuzumab (Campath-1H). In this study, we investigated the antitumor activity of a small-molecule survivin suppressant YM155 alone and in combination with alemtuzumab in a murine model of human ATL (MET-1). Both YM155 alone and its combination with alemtuzumab demonstrated therapeutic efficacy by lowering serum soluble IL-2Rα (sIL-2Rα) levels (P < .001) and prolonged the survival of tumor-bearing mice (P < .0001). Moreover, the combination of YM155 with alemtuzumab demonstrated markedly additive antitumor activity by significantly lowering serum sIL-2Rα levels and improving the survival of leukemia-bearing mice compared with monotherapy with either YM155 (P < .001) or alemtuzumab (P < .05). More significantly, all mice that received the combination therapy survived and were tumor free >6 months after treatment. Our data support a clinical trial of the combination of YM155 with alemtuzumab in ATL. This trial was registered at www.clinicaltrials.gov as #NCT00061048.

BIRC5 expression is a poor prognostic marker in Ewing sarcoma

BACKGROUND

BIRC5 (Survivin), an inhibitor of apoptosis protein (IAP), is over-expressed in several human cancers and increased expression is associated with poor prognosis. The goal of the current study was to evaluate the role of BIRC5 in Ewing sarcoma (ES), the second most common pediatric bone sarcoma.

PROCEDURE

BIRC5 protein expression was determined in ES cell lines using Western Blot analysis. Functional role of survivin on growth and viability of ES cells was assessed by siRNA knockdown of BIRC5 and by using a small molecule inhibitor YM155. Immunohistochemical analysis for BIRC5 protein was performed on patient tumor samples using an anti-survivin antibody. The degree of BIRC5 protein expression was correlated with clinical parameters and patient outcome.

RESULTS

BIRC5 is over-expressed in a panel of ES cell lines. Gene silencing of BIRC5 in the ES cell line TC-71 decreases cell growth by more than 50% for each BIRC5 siRNA construct compared to non-silencing siRNA control constructs. YM155 also reduces ES cell growth and viability with an EC(50) ranging from 2.8 to 6.2 nM. BIRC5 protein is expressed in majority of the ES tumor samples with minimal expression in normal tissue (P < 0.005). Tumors with more than 50% expression are associated with worse overall survival than tumors with less than 50% expression (Hazard Ratio: 6.05; CI: 1.7-21.4; P = 0.04).

CONCLUSION

BIRC5 is over-expressed in ES cell lines and tumor samples. Further, it plays an important role in cell growth and viability in vitro. Higher degree of expression in patients is an independent poor prognostic factor.

Survivin selective inhibitor YM155 induce apoptosis in SK-NEP-1 Wilms tumor cells

Background

Survivin, a member of the family of inhibitor of apoptosis proteins, functions as a key regulator of mitosis and programmed cell death. YM155, a novel molecular targeted agent, suppresses survivin, which is overexpressed in many tumor types. The aim of this study was to determine the antitumor activity of YM155 in SK-NEP-1 cells.

Methods

SK-NEP-1 cell growth in vitro and in vivo was assessed by MTT and nude mice experiments. Annexin V/propidium iodide staining followed by flow cytometric analysis was used to detect apoptosis in cell culture. Then gene expression profile of tumor cells treated with YM155 was analyzed with real-time PCR arrays. We then analyzed the expression data with MEV (Multi Experiment View) cluster software. Datasets representing genes with altered expression profile derived from cluster analyses were imported into the Ingenuity Pathway Analysis tool.

Results

YM155 treatment resulted in inhibition of cell proliferation of SK-NEP-1cells in a dose-dependent manner. Annexin V assay, cell cycle, and activation of caspase-3 demonstrates that YM155 induced apoptosis in SK-NEP-1 cells. YM155 significantly inhibited growth of SK-NEP-1 xenografts (YM155 5 mg/kg: 1.45 ± 0.77 cm³; YM155 10 mg/kg: 0.95 ± 0.55 cm³) compared to DMSO group (DMSO: 3.70 ± 2.4 cm³) or PBS group cells (PBS: 3.78 ± 2.20 cm³, ANOVA P < 0.01). YM155 treatment decreased weight of tumors (YM155 5 mg/kg: 1.05 ± 0.24 g; YM155 10 mg/kg: 0.72 ± 0.17 g) compared to DMSO group (DMSO: 2.06 ± 0.38 g) or PBS group cells (PBS: 2.36 ± 0.43 g, ANOVA P < 0.01). Real-time PCR array analysis showed between Test group and control group there are 32 genes significantly up-regulated and 54 genes were significantly down-regulated after YM155 treatment. Ingenuity pathway analysis (IPA) showed cell death was the highest rated network with 65 focus molecules and the significance score of 44. The IPA analysis also groups the differentially expressed genes into biological mechanisms that are related to cell death, cellular function maintenance, cell morphology, carbohydrate metabolism and cellular growth and proliferation. Death receptor signaling (3.87E-19), TNFR1 signaling, induction of apoptosis by HIV1, apoptosis signaling and molecular mechanisms of cancer came out to be the top four most significant pathways. IPA analysis also showed top molecules up-regulated were BBC3, BIRC3, BIRC8, BNIP1, CASP7, CASP9, CD5, CDKN1A, CEBPG and COL4A3, top molecules down-regulated were ZNF443, UTP11L, TP73, TNFSF10, TNFRSF1B, TNFRSF25, TIAF1, STK17A, SST and SPP1, upstream regulator were NR3C1, TP53, dexamethasone , TNF and Akt.

Conclusions

The present study demonstrates that YM155 treatment resulted in apoptosis and inhibition of cell proliferation of SK-NEP-1cells. YM155 had significant role and little side effect in the treatment of SK-NEP-1 xenograft tumors. Real-time PCR array analysis firstly showed expression profile of genes dyes-regulated after YM155 treatment. IPA analysis also represents new molecule mechanism of YM155 treatment, such as NR3C1 and dexamethasone may be new target of YM155. And our results may provide new clues of molecular mechanism of apoptosis induced by YM155.

What is recent in pancreatic cancer immunotherapy?

Pancreatic cancer (PC) represents an unresolved therapeutic challenge, due to the poor prognosis and the reduced response to currently available treatments. Pancreatic cancer is the most lethal type of digestive cancers, with a median survival of 4-6 months. Only a small proportion of PC patients is curative by surgical resection, whilst standard chemotherapy for patients in advanced disease generates only modest effects with considerable toxic damages. Thus, new therapeutic approaches, specially specific treatments such as immunotherapy, are needed. In this paper we analyze recent preclinical and clinical efforts towards immunotherapy of pancreatic cancer, including passive and active immunotherapy approaches, designed to target pancreatic-cancer-associated antigens and to elicit an antitumor response in vivo.

Drugging the undruggable: transcription therapy for cancer

Transcriptional regulation is often the convergence point of oncogenic signaling. It is not surprising, therefore, that aberrant gene expression is a hallmark of cancer. Transformed cells often develop a dependency on such a reprogramming highlighting the therapeutic potential of rectifying cancer-associated transcriptional abnormalities in malignant cells. Although transcription is traditionally considered as undruggable, agents have been developed that target various levels of transcriptional regulation including DNA binding by transcription factors, protein-protein interactions, and epigenetic alterations. Some of these agents have been approved for clinical use or entered clinical trials. While artificial transcription factors have been developed that can theoretically modulate expression of any given gene, the emergence of reliable reporter assays greatly facilitates the search for transcription-targeted agents. This review provides a comprehensive overview of these developments, and discusses various strategies applicable for developing transcription-targeted therapeutic agents.

Levels of effectiveness of gene therapies targeting survivin and its splice variants in human breast cancer cells

In order to develop an effective strategy of breast cancer therapy targeting survivin and its splice variants survivin-ΔEx3 and survivin-2B, the present study constructed four expression vectors by fusing the survivin antisense gene, the survivin (T34A) gene, the survivin-ΔEx3 antisense gene, and the survivin-2B gene with the enhanced green fluorescent protein (eGFP) gene. Each of these vectors was transiently transfected into the B-Cap-37 human breast cancer cell line. The effects of these four vectors with diverse genes on the proliferation and apoptosis of B-Cap-37 breast cancer cells were examined and compared in vitro using MTT and flow cytometry assays. Results of the MTT assay indicated that all four gene therapy plasmids were most effective at inhibiting the proliferation of B-Cap-37 cells 72 h after transfection. However, the four gene therapies had different rates of cell inhibition. pcDNA3.1(+)-egfp-anti-survivin and pcDNA3.1(+)-survivin (T34A)-egfp had almost equivalent or better effectiveness at suppressing cell growth. pcDNA3.1(+)-egfp-anti-survivin-ΔEx3 moderately inhibited the growth of B-Cap-37 cells. In contrast, pcDNA3.1(+)-survivin-2B-egfp had limited inhibition of cell growth. Similar profile of effectiveness of four gene therapies in soliciting cell apoptosis was also observed. These results suggest the relative importance of targeting survivin and its splice variant survivin-ΔEx3 in breast cancer treatment.

ZNF385B and VEGFA are strongly differentially expressed in serous ovarian carcinomas and correlate with survival

BACKGROUND

The oncogenesis of ovarian cancer is poorly understood. The aim of this study was to identify mRNAs differentially expressed between moderately and poorly differentiated (MD/PD) serous ovarian carcinomas (SC), serous ovarian borderline tumours (SBOT) and superficial scrapings from normal ovaries (SNO), and to correlate these mRNAs with clinical parameters including survival.

METHODS

Differences in mRNA expression between MD/PD SC, SBOT and SNO were analyzed by global gene expression profiling (n = 23), validated by RT-qPCR (n = 41) and correlated with clinical parameters.

RESULTS

Thirty mRNAs differentially expressed between MD/PD SC, SBOT and SNO were selected from the global gene expression analyses, and 21 were verified (p<0.01) by RT-qPCR. Of these, 13 mRNAs were differentially expressed in MD/PD SC compared with SNO (p<0.01) and were correlated with clinical parameters. ZNF385B was downregulated (FC = -130.5, p = 1.2×10(-7)) and correlated with overall survival (p = 0.03). VEGFA was upregulated (FC = 6.1, p = 6.0×10(-6)) and correlated with progression-free survival (p = 0.037). Increased levels of TPX2 and FOXM1 mRNAs (FC = 28.5, p = 2.7×10(-10) and FC = 46.2, p = 5.6×10(-4), respectively) correlated with normalization of CA125 (p = 0.03 and p = 0.044, respectively). Furthermore, we present a molecular pathway for MD/PD SC, including VEGFA, FOXM1, TPX2, BIRC5 and TOP2A, all significantly upregulated and directly interacting with TP53.

CONCLUSIONS

We have identified 21 mRNAs differentially expressed (p<0.01) between MD/PD SC, SBOT and SNO. Thirteen were differentially expressed in MD/PD SC, including ZNF385B and VEGFA correlating with survival, and FOXM1 and TPX2 with normalization of CA125. We also present a molecular pathway for MD/PD SC.

Clinicopathological and prognostic significance of survivin over-expression in patients with esophageal squamous cell carcinoma: a meta-analysis

Background

The prognostic significance of survivin for survival of patients with esophageal squamous cell carcinoma (ESCC) remains controversial. Thus, meta-analysis of the literatures was performed in order to demonstrate its expression impact on ESCC clinicopathological features and prognosis.

Methodology

Relevant literatures were searched using PubMed, EMBASE and Medline Databases. Revman5.0 software was used to pool eligible studies and summary hazard ratio (HR). Correlation between survivin expression and clinicopathological features of ESCC was analyzed.

Principal Findings

Final analysis of 523 patients from 7 eligible studies was performed. Combined HR of survivin location in nuclei suggested that survivin expression has an unfavorable impact on ESCC patients' survival (n = 277 in 3 studies; HR = 1.89, 95% CI: 1.45–2.96; Z = 4.69; P<0.0001). Nevertheless, combined HR of survivin location in cytoplasm displayed that survivin expression has no significance for prognosis of ESCC patients (n = 113 in 2 studies; HR = 0.96, 95% CI: 0.96–5.69; Z = 0.04; P = 0.97); Combined odds ratio (OR) of survivin location in cytoplasm indicated that survivin expression is associated with ESCC advanced stage (n = 113 in 2 studies; OR = 0.36, 95% CI: 0.14–0.93; Z = 2.10; P = 0.04). Whereas, combined OR of survivin location in nuclei exhibited that survivin over-expression has no correlation with cell differentiation grade, lymph node status, depth of invasion, stage, and metastasis of ESCC.

Conclusions

This study showed that survivin expression detected by immunohistochemistry seems to be associated with a worse prognosis of ESCC patients. Survivin subcellular location may be an important factor impacting on ESCC development. Larger prospective studies should be performed to evaluate the status of survivin in predicting prognosis of patients with ESCC.

Improving the efficacy and safety of engineered T cell therapy for cancer

Adoptive T-cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) is a powerful immunotherapeutics approach against metastatic melanoma. The success of TIL therapy has led to novel strategies for redirecting normal T cells to recognize tumor-associated antigens (TAAs) by genetically engineering tumor antigen-specific T cell receptors (TCRs) or chimeric antigen receptor (CAR) genes. In this manner, large numbers of antigen-specific T cells can be rapidly generated compared with the longer term expansion of TILs. Great efforts have been made to improve these approaches. Initial clinical studies have demonstrated that genetically engineered T cells can mediate tumor regression in vivo. In this review, we discuss the development of TCR and CAR gene-engineered T cells and the safety concerns surrounding the use of these T cells in patients. We highlight the importance of judicious selection of TAAs for modified T cell therapy and propose solutions for potential "on-target, off-organ" toxicity.

Kalanchoe tubiflora extract inhibits cell proliferation by affecting the mitotic apparatus

Background

Kalanchoe tubiflora (KT) is a succulent plant native to Madagascar, and is commonly used as a medicinal agent in Southern Brazil. The underlying mechanisms of tumor suppression are largely unexplored.

Methods

Cell viability and wound-healing were analyzed by MTT assay and scratch assay respectively. Cell cycle profiles were analyzed by FACS. Mitotic defects were analyzed by indirect immunofluoresence images.

Results

An n-Butanol-soluble fraction of KT (KT-NB) was able to inhibit cell proliferation. After a 48 h treatment with 6.75 μg/ml of KT, the cell viability was less than 50% of controls, and was further reduced to less than 10% at higher concentrations. KT-NB also induced an accumulation of cells in the G2/M phase of the cell cycle as well as an increased level of cells in the subG1 phase. Instead of disrupting the microtubule network of interphase cells, KT-NB reduced cell viability by inducing multipolar spindles and defects in chromosome alignment. KT-NB inhibits cell proliferation and reduces cell viability by two mechanisms that are exclusively involved with cell division: first by inducing multipolarity; second by disrupting chromosome alignment during metaphase.

Conclusion

KT-NB reduced cell viability by exclusively affecting formation of the proper structure of the mitotic apparatus. This is the main idea of the new generation of anti-mitotic agents. All together, KT-NB has sufficient potential to warrant further investigation as a potential new anticancer agent candidate.

BIRC6 (APOLLON) is down-regulated in acute myeloid leukemia and its knockdown attenuates neutrophil differentiation

Background

Inhibitors of apoptosis (IAPs) were intensively investigated in the context of cancer where they promote tumor growth and chemoresistence. Overexpression of the IAP BIRC6 is associated with unfavorable clinical features and negatively impacts relapse-free survival in childhood acute myeloid leukemia (AML). Currently, BIRC6 levels in adult primary AML have not been compared to the expression in normal myeloid cells. Thus, we compared for the first time BIRC6 levels in adult primary AML patient samples to normal myeloid cells and studied its regulation and function during neutrophil differentiation.

Findings

We found significantly lower BIRC6 levels in particular AML subtypes as compared to granulocytes from healthy donors. The lowest BIRC6 expression was found in CD34⁺ progenitor cells. Moreover, BIRC6 expression significantly increased during neutrophil differentiation of AML cell lines and knocking down BIRC6 in NB4 acute promyelocytic leukemia (APL) cells significantly impaired neutrophil differentiation, but not cell viability.

Conclusion

Together, we found an association of low BIRC6 levels with an immature myeloid phenotype and describe a function for BIRC6 in neutrophil differentiation of APL cells.

Histone methylase MLL1 has critical roles in tumor growth and angiogenesis and its knockdown suppresses tumor growth in vivo

Mixed lineage leukemias (MLL) are human histone H3 lysine-4 specific methyl transferases that play critical roles in gene expression, epigenetics, and cancer. Herein, we demonstrated that antisense-mediated knockdown of MLL1 induced cell cycle arrest and apoptosis in cultured cells. Intriguingly, application of MLL1-antisense specifically knocked down MLL1 in vivo and suppressed the growth of xenografted cervical tumor implanted in nude mouse. MLL1-knockdown downregulated various growth and angiogenic factors such as HIF1α, VEGF and CD31 in tumor tissue affecting tumor growth. MLL1 is overexpressed along the line of vascular network and localized adjacent to endothelial cell layer expressing CD31, indicating potential roles of MLL1 in vasculogenesis. MLL1 is also overexpressed in the hypoxic regions along with HIF1α. Overall, our studies demonstrated that MLL1 is a key player in hypoxia signaling, vasculogenesis, and tumor growth, and its depletion suppresses tumor growth in vivo, indicating its potential in novel cancer therapy.

Cannabidiol treatment ameliorates ischemia/reperfusion renal injury in rats

AIMS

To investigate the protective effect of cannabidiol, the major non-psychotropic Cannabis constituent, against renal ischemia/reperfusion injury in rats.

MAIN METHODS

Bilateral renal ischemia was induced for 30 min followed by reperfusion for 24h. Cannabidiol (5mg/kg, i.v.) was given 1h before and 12h following the procedure.

KEY FINDINGS

Ischemia/reperfusion caused significant elevations of serum creatinine and renal malondialdehyde and nitric oxide levels, associated with a significant decrease in renal reduced glutathione. Cannabidiol significantly attenuated the deterioration in the measured biochemical parameters induced by ischemia/reperfusion. Histopathological examination showed that cannabidiol ameliorated ischemia/reperfusion-induced kidney damage. Immunohistochemical analysis revealed that cannabidiol significantly reduced the expression of inducible nitric oxide synthase, tumor necrosis factor-α, cyclooxygenase-2, nuclear factor-κB, Fas ligand and caspase-3, and increased the expression of survivin in ischemic/reperfused kidney tissue.

SIGNIFICANCE

Cannabidiol, via its antioxidant and anti-inflammatory properties, may represent a potential therapeutic option to protect against ischemia/reperfusion renal injury.