Effects of E2F1-cyclin E1-E2 circuit down regulation in hepatocellular carcinoma cells

Effects of weaning on intestinal longitudinal muscle-myenteric plexus function in piglets

Weaning piglets usually suffer from severe diarrhea (commonly known as postweaning diarrhea, PWD) along with intestinal motility disorder. Intestinal peristalsis is mainly regulated by the longitudinal muscle-myenteric plexus (LM-MP). To understand the relationship between intestinal LM-MP function and the development of PWD, we compared the intestinal electrical activity, and the transcriptional profile of the LM-MP between 21-day-old piglets (just weaned, n=7) and 24-day-old piglets (suffered the most severe weaning stress, n=7). The results showed that 24-day-old piglets exhibited different degrees of diarrhea. A significant increase in the slow-wave frequency in the ileum and colon was observed in 24-day-old piglets, while c-kit expression in the intestinal LM-MPs was significantly decreased, indicating that PWD caused by elevated slow-wave frequency may be associated with loss of c-kit. The real-time quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) showed that intestinal LM-MPs in 24-day-old piglets may undergo inflammation and oxidative stress. Significant increases in 8-hydroxy-2'-deoxyguanosine and decreases in thioredoxin suggest that weaning may lead to DNA damage in the LM-MP of 24-day-old piglets. In addition, activating transcription factor 3 was significantly upregulated, indicating nerve damage in the LM-MP of 24-day-old piglets. The transcriptomic results showed that most of the differentially expressed genes in the ileal LM-MP after weaning were downregulated and closely related to the cell cycle process. Subsequent RT-qPCR analysis showed that the relative expression of p21 was upregulated, while the expression of cyclin A2, cyclin B1, and proliferating cell nuclear antigen was downregulated in the ileal and colonic LM-MP of 24-day-old piglets, suggesting that weaning may inhibit cell proliferation and cause G1/S cell cycle arrest in ileal and colonic LM-MP. In conclusion, weaning may lead to cell cycle arrest by causing DNA damage in the LM-MP, impairing intestinal motility regulation, and ultimately leading to diarrhea in piglets.

Angiopoietin-1 Upregulates Cancer Cell Motility in Colorectal Cancer Liver Metastases through Actin-Related Protein 2/3

Resistance to anti-angiogenic therapy is a major challenge in the treatment of colorectal cancer liver metastases (CRCLMs). Vessel co-option has been identified as a key contributor to anti-angiogenic therapy resistance in CRCLMs. Recently, we identified a positive correlation between the expression of Angiopoietin1 (Ang1) in the liver and the development of vessel co-opting CRCLM lesions in vivo. However, the mechanisms underlying its stimulation of vessel co-option are unclear. Herein, we demonstrated Ang1 as a positive regulator of actin-related protein 2/3 (ARP2/3) expression in cancer cells, in vitro and in vivo, which is known to be essential for the formation of vessel co-option in CRCLM. Significantly, Ang1-dependent ARP2/3 expression was impaired in the cancer cells upon Tie2 or PI3K/AKT inhibition in vitro. Taken together, our results suggest novel mechanisms by which Ang1 confers the development of vessel co-option in CRCLM, which, targeting this pathway, may serve as promising therapeutic targets to overcome the development of vessel co-option in CRCLM.

5-Azacytidine Downregulates the Proliferation and Migration of Hepatocellular Carcinoma Cells In Vitro and In Vivo by Targeting miR-139-5p/ROCK2 Pathway

BACKGROUND

For hepatocellular carcinoma (HCC), effective therapeutic approaches are lacking. As aberrant gene methylation is a major contributor to HCC development, demethylating drugs such as 5-azacytidine (5-Aza) have been proposed. As most 5-Aza mechanisms of action are unknown, we investigated its phenotypic/molecular effects.

METHODS

5-Aza effects were examined in the human HCC cell lines JHH-6/HuH-7 and in the rat cell-line N1-S1. We also employed a xenograft mouse model (HuH-7), a zebrafish model (JHH-6), and an orthotopic syngeneic rat model (N1-S1) of HCC.

RESULTS

5-Aza downregulated cell viability/growth/migration/adhesion by upregulating miR-139-5p, which in turn downregulated ROCK2/cyclin D1/E2F1 and increased p27kip1, resulting in G1/G0 cell accumulation. Moreover, a decrease in cyclin B1 and an increase in p27kip1 led to G2/M accumulation. Finally, we observed a decrease in MMP-2 levels, a stimulator of HCC cell migration. Aza effects were confirmed in the mouse model; in the zebrafish model, we also demonstrated the downregulation of tumor neo-angiogenesis, and in the orthotopic rat model, we observed impaired N1-S1 grafting in a healthy liver.

CONCLUSION

We demonstrate for the first time that 5-Aza can impair HCC development via upregulation of miR-139-5p, which in turn impairs the ROCK2/cyclin D1/E2F1/cyclin B1 pro-proliferative pathway and the ROCK2/MMP-2 pro-migratory pathway. Thus, we provide novel information about 5-Aza mechanisms of action and deepen the knowledge about the crosstalk among ROCK2/cyclin D1/E2F1/cyclin B1/p27kip1/MMP-2 in HCC.

Cancer Cells Promote Phenotypic Alterations in Hepatocytes at the Edge of Cancer Cell Nests to Facilitate Vessel Co-Option Establishment in Colorectal Cancer Liver Metastases

Vessel co-option is correlated with resistance against anti-angiogenic therapy in colorectal cancer liver metastases (CRCLM). Vessel co-opting lesions are characterized by highly motile cancer cells that move toward and along the pre-existing vessels in the surrounding nonmalignant tissue and co-opt them to gain access to nutrients. To access the sinusoidal vessels, the cancer cells in vessel co-opting lesions must displace the hepatocytes and occupy their space. However, the mechanisms underlying this displacement are unknown. Herein, we examined the involvement of apoptosis, autophagy, motility, and epithelial-mesenchymal transition (EMT) pathways in hepatocyte displacement by cancer cells. We demonstrate that cancer cells induce the expression of the proteins that are associated with the upregulation of apoptosis, motility, and EMT in adjacent hepatocytes in vitro and in vivo. Accordingly, we observe the upregulation of cleaved caspase-3, cleaved poly (ADP-ribose) polymerase-1 (PARP-1) and actin-related protein 2/3 (ARP2/3) in adjacent hepatocytes to cancer cell nests, while we notice a downregulation of E-cadherin. Importantly, the knockdown of runt-related transcription factor 1 (RUNX1) in cancer cells attenuates the function of cancer cells in hepatocytes alterations in vitro and in vivo. Altogether, our data suggest that cancer cells exploit various mechanisms to displace hepatocytes and access the sinusoidal vessels to establish vessel co-option.

E2F transcription factor 1 (E2F1) promotes the transforming growth factor TGF-β1 induced human cardiac fibroblasts differentiation through promoting the transcription of CCNE2 gene

The differentiation of cardiac fibroblast to myofibroblast is the key process of cardiac fibrosis. In the study, we aimed to determine the function of E2F Transcription Factor 1 (E2F1) in human cardiac fibroblasts (HCFs) differentiation, search for its downstream genes and elucidate the function of them in HCFs differentiation. As a result, we found that E2F1 was up-regulated in TGF-β1-induced HCFs differentiation. Silencing the expression of E2F1 by siRNA in HCFs, we found that the expression of differentiation-related genes (Collagen-1, α-Smooth muscle actin, and Fibronectin-1) was significantly suppressed, combining with proliferation and migration assay, we determined that HCFs differentiation was decreased. Luciferase report assay and immunoprecipitation proved that the oncogene CCNE2 was a direct target gene of E2F1, overexpression of CCNE2 was found in differentiated HCFs, silencing the expression of CCNE2 by siRNA decreased HCFs differentiation. Our research suggested that E2F1 and its downstream target gene CCNE2 play a vital role in TGF-β1-induced HCFs differentiation, thus E2F1 and CCNE2 may be a potential therapeutic target for cardiac fibrosis.

Anti-Proliferative Effects of E2F1 Suppression in Glioblastoma Cells

Glioblastoma (GBM) is an aggressive malignant brain tumor; surgery, radiation, and temozolomide still remain the main treatments. There is evidence that E2F1 is overexpressed in various types of cancer, including GBM. E2F1 is a transcription factor that controls the cell cycle progression and regulates DNA damage responses and the proliferation of pluripotent and neural stem cells. To test the potentiality of E2F1 as molecular target for GBM treatment, we suppressed the E2F1 gene (siRNA) in the U87MG cell line, aiming to inhibit cellular proliferation and modulate the radioresistance of these cells. Following E2F1 suppression, associated or not with gamma-irradiation, several assays (cell proliferation, cell cycle analysis, neurosphere counting, and protein expression) were performed in U87MG cells grown as monolayer or neurospheres. We found that siE2F1-suppressed cells showed reduced cell proliferation and increased cell death (sub-G1 fraction) in monolayer cultures, and also a significant reduction in the number of neurospheres. In addition, in irradiated cells, E2F1 suppression caused similar effects, with reduction of the number of neurospheres and neurosphere cell numbers relative to controls; these results suggest that E2F1 plays a role in the maintenance of GBM stem cells, and our results obtained in neurospheres are relevant within the context of radiation resistance. Furthermore, E2F1 suppression inhibited or delayed GBM cell differentiation by maintaining a reasonable proportion of CD133+ cells when grown at differentiation condition. Therefore, E2F1 proved to be an interesting molecular target for therapeutic intervention in U87MG cells.

Xenograft Zebrafish Models for the Development of Novel Anti-Hepatocellular Carcinoma Molecules

Hepatocellular carcinoma (HCC) is the sixth most common type of tumor and the second leading cause of tumor-related death worldwide. Liver cirrhosis is the most important predisposing factor for HCC. Available therapeutic approaches are not very effective, especially for advanced HCC, which is the most common form of the disease at diagnosis. New therapeutic strategies are therefore urgently needed. The use of animal models represents a relevant tool for preclinical screening of new molecules/strategies against HCC. However, several issues, including animal husbandry, limit the use of current models (rodent/pig). One animal model that has attracted the attention of the scientific community in the last 15 years is the zebrafish. This freshwater fish has several attractive features, such as short reproductive time, limited space and cost requirements for husbandry, body transparency and the fact that embryos do not show immune response to transplanted cells. To date, two different types of zebrafish models for HCC have been developed: the transgenic zebrafish and the zebrafish xenograft models. Since transgenic zebrafish models for HCC have been described elsewhere, in this review, we focus on the description of zebrafish xenograft models that have been used in the last five years to test new molecules/strategies against HCC.

Runt related transcription factor-1 plays a central role in vessel co-option of colorectal cancer liver metastases

Colorectal cancer liver metastasis (CRCLM) has two major histopathological growth patterns: angiogenic desmoplastic and non-angiogenic replacement. The replacement lesions obtain their blood supply through vessel co-option, wherein the cancer cells hijack pre-existing blood vessels of the surrounding liver tissue. Consequentially, anti-angiogenic therapies are less efficacious in CRCLM patients with replacement lesions. However, the mechanisms which drive vessel co-option in the replacement lesions are unknown. Here, we show that Runt Related Transcription Factor-1 (RUNX1) overexpression in the cancer cells of the replacement lesions drives cancer cell motility via ARP2/3 to achieve vessel co-option. Furthermore, overexpression of RUNX1 in the cancer cells is mediated by Transforming Growth Factor Beta-1 (TGFβ1) and thrombospondin 1 (TSP1). Importantly, RUNX1 knockdown impaired the metastatic capability of colorectal cancer cells in vivo and induced the development of angiogenic lesions in liver. Our results confirm that RUNX1 may be a potential target to overcome vessel co-option in CRCLM.

E2F1 transcriptionally regulates CCNA2 expression to promote triple negative breast cancer tumorigenicity

BACKGROUND

Triple-negative breast cancer (TNBC) is a highly malignant breast cancer subtype with a poor prognosis. The cell cycle regulator cyclin A2 (CCNA2) plays a role in tumor development. Herein, we explored the role of CCNA2 in TNBC.

METHODS

We analyzed CCNA2 expression in 15 pairs of TNBC and adjacent tissues and assessed the relationship between CCNA2 expression using the tissue microarray cohort. Furthermore, we used two TNBC cohort datasets to analyze the correlation between CCNA2 and E2F transcription factor 1 (E2F1) and a luciferase reporter to explore their association. Through rescue experiments, we analyzed the effects of E2F1 knockdown on CCNA2 expression and cellular behavior.

RESULTS

We found that CCNA2 expression in TNBC was significantly higher than that in adjacent tissues with similar observations in MDA-MB-231 and MDA-MB-468 cells. E2F1 was highly correlated with CCNA2 as observed through bioinformatics analysis (R= 0.80, P< 0.001) and through TNBC tissue verification analysis (R= 0.53, P< 0.001). We determined that E2F1 binds the +677 position within the CCNA2 promoter. Moreover, CCNA2 overexpression increased cell proliferation, invasion, and migration owing to E2F1 upregulation in TNBC.

CONCLUSION

Our data indicate that E2F1 promotes TNBC proliferation and invasion by upregulating CCNA2 expression. E2F1 and CCNA2 are potential candidates that may be targeted for effective TNBC treatment.

LncRNA SNHG6 promotes G1/S-phase transition in hepatocellular carcinoma by impairing miR-204-5p-mediated inhibition of E2F1

Emerging evidence suggests that long noncoding RNAs (lncRNAs) function as competitive endogenous RNA (ceRNA) targeting proteins and genes; however, the role of lncRNAs in hepatocellular carcinoma (HCC) is not well understood. We investigated the mechanism by which lncRNA SNHG6 promotes the development of HCC. RT-qPCR revealed upregulated lncRNA SNHG6 in the HCC setting. Elevated SNHG6 expression was indicative of poor prognosis in patients with HCC. SNHG6 overexpression resulted in increased cyclin D1, cyclin E1, and E2F1 expression both in vitro and in vivo. SNHG6 also promoted HCC cell proliferation by enhancing G1-S phase transition in vitro. Dual luciferase reporter assays, RIP, and RNA pull-down assays demonstrated SNHG6 competitively bound to miR-204-5p and inhibited its expression preventing miR-204-5p from targeting E2F1. Overexpression of miR-204-5p abolished the effect of SNHG6. Our data suggest that SNHG6 functions as a ceRNA that targets miR-204-5p resulting in an increased E2F1 expression and enhanced G1-S phase transition, thereby promoting the tumorigenesis of HCC.

Targeted delivery of siRNAs against hepatocellular carcinoma-related genes by a galactosylated polyaspartamide copolymer

Given the lack of effective treatments for Hepatocellular carcinoma (HCC), the development of novel therapeutic approaches is very urgent. Here, siRNAs were delivered to HCC cells by a synthetic polymer containing α,β-poly-(N-2-hydroxyethyl)-D,L-aspartamide-(PHEA) derivatized with diethylene triamine (DETA) and bearing in the side chain galactose (GAL) linked via a polyethylene glycol (PEG) to obtain (PHEA-DETA-PEG-GAL, PDPG). The GAL residue allows the targeting to the asialo-glycoprotein receptor (ASGPR), overexpressed in HCC cells compared to normal hepatocytes. Uptake studies performed using a model siRNA or a siRNA targeted against the enhanced green fluorescence protein, demonstrated the PDPG specific delivery of siRNA to HuH7 cells, a human cellular model of HCC. GAL-free copolymer (PHEA-DETA-PEG-NH2, PDP) or the chemical block of ASGPR, impaired PDPG targeting effectiveness in vitro. The specificity of PDPG delivery was confirmed in vivo in a mouse dorsal skinfold window chamber assay. Functional studies using siRNAs targeting the mRNAs of HCC-related genes (eEF1A1, eEF1A2 and E2F1) delivered by PDPG, significantly decreased HuH7 vitality/number and down regulated the expression of the target genes. Only minor effectiveness was in contrast observed for PDP. In IHH, a human model of normal hepatocytes with reduced ASGPR expression, PDPG barely reduced cell vitality. In a subcutaneous xenograft mouse model of HCC, PDPG-siRNAs reduced HCC tumor growth compared to controls without significant toxic effects. In conclusion, our study demonstrates the valuable potentials of PDPG for the specific delivery of siRNAs targeting HCC-related genes.

Effects of eEF1A1 targeting by aptamer/siRNA in chronic lymphocytic leukaemia cells

BACKGROUND

The effectiveness of therapies for chronic lymphocytic leukemia (CLL), the most common leukemia in Western countries adults, can be improved via a deeper understanding of its molecular abnormalities. Whereas the isoforms of the eukaryotic elongation factor 1A (eEF1A1 and eEF1A2) are implicated in different tumors, no information are available in CLL.

METHODS

eEF1A1/eEF1A2 amounts were quantitated in the lymphocytes of 46 CLL patients vs normal control (real time PCR, western blotting). eEF1A1 role in CLL was investigated in a cellular (MEC-1) and animal model of CLL via its targeting by an aptamer (GT75) or a siRNA (siA1) delivered by electroporation (in vitro) or lipofection (in vivo).

RESULTS

eEF1A1/eEF1A2 were elevated in CLL lymphocytes vs control. eEF1A1 but not eEF1A2 levels were higher in patients which died during the study compared to those surviving. eEF1A1 targeting (GT75/siA1) resulted in MEC-1 viability reduction/autophagy stimulation and in vivo tumor growth down-regulation.

CONCLUSIONS

The increase of eEF1A1 in dead vs surviving patients may confer to eEF1A1 the role of a prognostic marker for CLL and possibly of a therapeutic target, given its involvement in MEC-1 survival. Specific aptamer/siRNA released by optimized delivery systems may allow the development of novel therapeutic options.

Strategies for Delivery of siRNAs to Ovarian Cancer Cells

The unmet need for novel therapeutic options for ovarian cancer (OC) deserves further investigation. Among the different novel drugs, small interfering RNAs (siRNAs) are particularly attractive because of their specificity of action and efficacy, as documented in many experimental setups. However, the fragility of these molecules in the biological environment necessitates the use of delivery materials able to protect them and possibly target them to the cancer cells. Among the different delivery materials, those based on polymers and lipids are considered very interesting because of their biocompatibility and ability to carry/deliver siRNAs. Despite these features, polymers and lipids need to be engineered to optimize their delivery properties for OC. In this review, we concentrated on the description of the therapeutic potential of siRNAs and polymer-/lipid-based delivery systems for OC. After a brief description of OC and siRNA features, we summarized the strategies employed to minimize siRNA delivery problems, the targeting strategies to OC, and the preclinical models available. Finally, we discussed the most interesting works published in the last three years about polymer-/lipid-based materials for siRNA delivery.

Small interfering RNA-mediated gene suppression as a therapeutic intervention in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the lethal and difficult-to-cure cancers worldwide. Owing to the late diagnosis and drug resistance of malignant hepatocytes, treatment of this cancer by conventional chemotherapy agents is challenging, and researchers are seeking new alternative treatment options to overcome therapy resistance in this neoplasm. RNA interference (RNAi) is a potent and specific approach in targeting gene expression and has emerged as a novel therapeutic tool for many diseases, including cancers. Small interfering RNA (siRNA) is a type of RNAi that is produced intracellularly from exogenous synthetic oligonucleotides and can selectively knock down target gene expression in a sequence-specific manner. Various factors play roles in the initiation and progression of HCC and provide multiple candidate targets for siRNA intervention. In addition, due to the liver's unique architecture and availability of some hepatic siRNA delivery methods, this organ has received much more attention as a target tissue for such oligonucleotide action. Recent advances in designing nanoparticle systems for the in vivo delivery of siRNAs have markedly enhanced the potency of siRNA-mediated gene silencing under clinical development for HCC therapy. The utility of siRNAs as anti-HCC agents is the subject of the current review. siRNA-based gene therapies could be one of the main feasible approaches for HCC therapy in the future.

Combined Used of Rheology and LF-NMR for the Characterization of PVP-Alginates Gels Containing Liposomes

PURPOSE

This paper is based on the characterization of the rheological and Low Field NMR (LF-NMR) properties of an interpenetrated hydrogel made up by poly(N-vinyl-2-pyrrolidone) and sodium alginate. The final aim is to use the hydrogel as a delivery matrix for liposomes, widely used tools in the drug delivery field.

METHODS

Rheology, LF-NMR, TEM, cryo-TEM, confocal laser scanning microscopy and release test were employed to characterize the interpenetrated hydrogel. Different theoretical approaches such as Flory, Chui, Scherer and Schurz theories were used to interpret the experimental results.

RESULTS

We found that the crosslinking mechanisms of the two polymers produced an anti-synergistic effect on the final mechanical properties of the interpenetrated hydrogel. Instead of creating a continuous network, alginate formed isolated, cross-linked, clusters embedded in a continuous network of poly(N-vinyl-2-pyrrolidone). Additionally, gel structure significantly influenced liposome delivery.

CONCLUSIONS

The rheological and LF-NMR characterization were confirmed and supported by the independent techniques TEM, cryo-TEM and release tests Thus, our findings reiterate the potentiality of both rheology and LF-NMR for the characterisation of soft materials such as interpenetrated polymeric networks.

Polymer-Mediated Delivery of siRNAs to Hepatocellular Carcinoma: Variables Affecting Specificity and Effectiveness

Despite the advances in anticancer therapies, their effectiveness for many human tumors is still far from being optimal. Significant improvements in treatment efficacy can come from the enhancement of drug specificity. This goal may be achieved by combining the use of therapeutic molecules with tumor specific effects and delivery carriers with tumor targeting ability. In this regard, nucleic acid-based drug (NABD) and particularly small interfering RNAs (siRNAs), are attractive molecules due to the possibility to be engineered to target specific tumor genes. On the other hand, polymeric-based delivery systems are emerging as versatile carriers to generate tumor-targeted delivery systems. Here we will focus on the most recent findings in the selection of siRNA/polymeric targeted delivery systems for hepatocellular carcinoma (HCC), a human tumor for which currently available therapeutic approaches are poorly effective. In addition, we will discuss the most attracting and, in our opinion, promising siRNA-polymer combinations for HCC in relation to the biological features of HCC tissue. Attention will be also put on the mathematical description of the mechanisms ruling siRNA-carrier delivery, this being an important aspect to improve effectiveness reducing the experimental work.

Functional characterization of E2F3b in human HepG2 liver cancer cell line

E2F3 is a transcription factor that has been shown to be overexpressed in hepatocellular carcinoma (HCC). It is well-known that the E2F3 gene encodes two proteins E2F3a and E2F3b. Therefore, the functions of the two distinct isoforms need to be clarified separately. To characterize the function of E2F3b in HCC, the effects of ectopic expression of E2F3b on cell proliferation, cell cycle, apoptosis and gene expression were investigated. E2F3b promoted G1/S phase transition and markedly increased cell proliferation, but had minor effect on apoptosis. Microarray analyses identified 366 differentially expressed genes (171 upregulated and 195 downregulated) in E2F3b- overexpressing cells. Differential expression of 16 genes relevant to cell cycle and cell proliferation were further verified by real-time PCR. Six genes, including CDC2, CCNE1, ARF, MAP4K2, MUSK, and PAX2 were confirmed to be upregulated by more than twofold; one gene, CCNA2 was validated to be downregulated by more than twofold. We also confirmed that E2F3b increased the protein levels of both cyclin E and Arf but did not affect cyclin D1 protein. These results suggest that E2F3b functions as an important promoter for cell proliferation and plays important roles in transcriptional regulation in HepG2 liver cancer cells.

Recent advances in smart biotechnology: Hydrogels and nanocarriers for tailored bioactive molecules depot

Over the past ten years, the global biopharmaceutical market has remarkably grown, with ten over the top twenty worldwide high performance medical treatment sales being biologics. Thus, biotech R&D (research and development) sector is becoming a key leading branch, with expanding revenues. Biotechnology offers considerable advantages compared to traditional therapeutic approaches, such as reducing side effects, specific treatments, higher patient compliance and therefore more effective treatments leading to lower healthcare costs. Within this sector, smart nanotechnology and colloidal self-assembling systems represent pivotal tools able to modulate the delivery of therapeutics. A comprehensive understanding of the processes involved in the self-assembly of the colloidal structures discussed therein is essential for the development of relevant biomedical applications. In this review we report the most promising and best performing platforms for specific classes of bioactive molecules and related target, spanning from siRNAs, gene/plasmids, proteins/growth factors, small synthetic therapeutics and bioimaging probes.

The hnRNP RALY regulates transcription and cell proliferation by modulating the expression of specific factors including the proliferation marker E2F1

The heterogeneous nuclear ribonucleoproteins (hnRNP) form a large family of RNA-binding proteins that exert numerous functions in RNA metabolism. RALY is a member of the hnRNP family that binds poly-U-rich elements within several RNAs and regulates the expression of specific transcripts. RALY is up-regulated in different types of cancer, and its down-regulation impairs cell cycle progression. However, the RALY's role in regulating RNA levels remains elusive. Here, we show that numerous genes coding for factors involved in transcription and cell cycle regulation exhibit an altered expression in RALY-down-regulated HeLa cells, consequently causing impairments in transcription, cell proliferation, and cell cycle progression. Interestingly, by comparing the list of RALY targets with the list of genes affected by RALY down-regulation, we found an enrichment of RALY mRNA targets in the down-regulated genes upon RALY silencing. The affected genes include the E2F transcription factor family. Given its role as proliferation-promoting transcription factor, we focused on E2F1. We demonstrate that E2F1 mRNA stability and E2F1 protein levels are reduced in cells lacking RALY expression. Finally, we also show that RALY interacts with transcriptionally active chromatin in both an RNA-dependent and -independent manner and that this association is abolished in the absence of active transcription. Taken together, our results highlight the importance of RALY as an indirect regulator of transcription and cell cycle progression through the regulation of specific mRNA targets, thus strengthening the possibility of a direct gene expression regulation exerted by RALY.

Potential Applications of Nanocellulose-Containing Materials in the Biomedical Field

Because of its high biocompatibility, bio-degradability, low-cost and easy availability, cellulose finds application in disparate areas of research. Here we focus our attention on the most recent and attractive potential applications of cellulose in the biomedical field. We first describe the chemical/structural composition of cellulose fibers, the cellulose sources/features and cellulose chemical modifications employed to improve its properties. We then move to the description of cellulose potential applications in biomedicine. In this field, cellulose is most considered in recent research in the form of nano-sized particle, i.e., nanofiber cellulose (NFC) or cellulose nanocrystal (CNC). NFC is obtained from cellulose via chemical and mechanical methods. CNC can be obtained from macroscopic or microscopic forms of cellulose following strong acid hydrolysis. NFC and CNC are used for several reasons including the mechanical properties, the extended surface area and the low toxicity. Here we present some potential applications of nano-sized cellulose in the fields of wound healing, bone-cartilage regeneration, dental application and different human diseases including cancer. To witness the close proximity of nano-sized cellulose to the practical biomedical use, examples of recent clinical trials are also reported. Altogether, the described examples strongly support the enormous application potential of nano-sized cellulose in the biomedical field.

Engineering approaches in siRNA delivery

siRNAs are very potent drug molecules, able to silence genes involved in pathologies development. siRNAs have virtually an unlimited therapeutic potential, particularly for the treatment of inflammatory diseases. However, their use in clinical practice is limited because of their unfavorable properties to interact and not to degrade in physiological environments. In particular they are large macromolecules, negatively charged, which undergo rapid degradation by plasmatic enzymes, are subject to fast renal clearance/hepatic sequestration, and can hardly cross cellular membranes. These aspects seriously impair siRNAs as therapeutics. As in all the other fields of science, siRNAs management can be advantaged by physical-mathematical descriptions (modeling) in order to clarify the involved phenomena from the preparative step of dosage systems to the description of drug-body interactions, which allows improving the design of delivery systems/processes/therapies. This review analyzes a few mathematical modeling approaches currently adopted to describe the siRNAs delivery, the main procedures in siRNAs vectors' production processes and siRNAs vectors' release from hydrogels, and the modeling of pharmacokinetics of siRNAs vectors. Furthermore, the use of physical models to study the siRNAs vectors' fate in blood stream and in the tissues is presented. The general view depicts a framework maybe not yet usable in therapeutics, but with promising possibilities for forthcoming applications.

Galactosylated polyaspartamide copolymers for siRNA targeted delivery to hepatocellular carcinoma cells

The limited efficacy of available treatments for hepatocellular carcinoma (HCC) requires the development of novel therapeutic approaches. We synthesized a novel cationic polymer based on α,β-poly-(N-2-hydroxyethyl)-d,L-aspartamide (PHEA) for drug delivery to HCC cells. The copolymer was synthesized by subsequent derivatization of PHEA with diethylene triamine (DETA) and with a polyethylene glycol (PEG) derivative bearing galactose (GAL) molecules, obtaining the cationic derivative PHEA-DETA-PEG-GAL. PHEA-DETA-PEG-GAL has suitable chemical-physical characteristics for a potential systemic use and can effectively deliver a siRNA (siE2F1) targeted against the transcription factor E2F1, a gene product involved in HCC. The presence of GAL residues in the polyplexes allows the targeting of HCC cells that express the asialo-glycoprotein receptor (ASGP-R). In these cells, but not in ASGP-R non-expressing cells, PHEA-DETA-PEG-GAL/siE2F1 polyplexes induce the reduction of the mRNA and protein levels of E2F1 and of E2F1-regulated genes, all involved in the promotion of the G1/S phase transition. This results in a decrease of cell proliferation with a G1/G0 phase cells accumulation. Notably, removal of GAL residue almost completely abrogates the targeting capacity of the developed polyplexes. In conclusion, the generated polyplexes demonstrate the potential to effectively contributing to the development of novel anti-HCC therapeutic approaches via a siRNA-targeted delivery.

Dissecting the role of the elongation factor 1A isoforms in hepatocellular carcinoma cells by liposome-mediated delivery of siRNAs

Eukaryotic elongation factor 1A (eEF1A), a protein involved in protein synthesis, has two major isoforms, eEF1A1 and eEF1A2. Despite the evidences of their involvement in hepatocellular carcinoma (HCC), the quantitative contribution of each of the two isoforms to the disease is unknown. We depleted the two isoforms by means of siRNAs and studied the effects in three different HCC cell lines. Particular care was dedicated to select siRNAs able to target each of the two isoform without affecting the other one. This is not a trivial aspect due to the high sequence homology between eEF1A1 and eEF1A2. The selected siRNAs can specifically deplete either eEF1A1 or eEF1A2. This, in turn, results in an impairment of cell vitality, growth and arrest in the G1/G0 phase of the cell cycle. Notably, these effects are quantitatively superior following eEF1A1 than eEF1A2 depletion. Moreover, functional tests revealed that the G1/G0 block induced by eEF1A1 depletion depends on the down-regulation of the transcription factor E2F1, a known player in HCC. In conclusion, our data indicate that the independent targeting of the two eEF1A isoforms is effective in reducing HCC cell growth and that eEF1A1 depletion may result in a more evident effect.

In vitro and ex vivo delivery of tailored siRNA-nanoliposomes for E2F1 silencing as a potential therapy for colorectal cancer

Tailored developed nanoliposomes loaded with a siRNA against the transcription factor E2F1 (siE2F1), were produced and delivered to human colorectal adenocarcinoma cell lines and to intestinal human biopsies. siE2F1 loaded nanoliposomes were produced through a dedicated ultrasound assisted technique producing particles with about 40nm size (Small Unilamellar Vesicles, SUVs) and 100% siRNA encapsulation efficiency. Compared to other production methods, the one proposed here can easily produce particles in the nanometric scale by suitable ultrasonic duty cycle treatments. Furthermore, SUVs have a high degree of size homogeneity, a relevant feature for uniform delivery behaviour. siE2F1-loaded SUVs demonstrated a very low cytotoxicity in cells when compared to a commercial transfection agent. Moreover, SUVs loaded with siE2F1 were effective in the down regulation of the target in cultured colon carcinoma cells and in the consequent reduction of cell growth. Finally, a remarkable uptake and target silencing efficiencies were observed in cultured human biopsy of colonic mucosa. In conclusion, whereas further studies in more complex models are required, the siE2F1-SUVs generated have the potential to contribute to the development of novel effective inflammatory bowel diseases-associated colorectal cancer therapies for a future personalized medicine.

Strategies to optimize siRNA delivery to hepatocellular carcinoma cells

hepatocellular carcinoma (hcc) is the predominant form of primary liver cancer and the second leading cause of cancer-associated mortality worldwide. available therapies for hcc have limited efficacy due to often late diagnosis and the general resistance of hcc to anti-cancer agents; therefore, the development of novel therapeutics is urgently required. small-interfering rna (sirna) molecules are short, double-stranded rnas that specifically recognize and bind the mrna of a target gene to inhibit gene expression. despite the great therapeutic potential of sirnas towards many human tumors including hcc, their use is limited by suboptimal delivery. Areas covered: In this review, we outline the current data regarding the therapeutic potential of siRNAs in HCC and describe the development of effective siRNA delivery systems. We detail the key problems associated with siRNA delivery and discuss the possible solutions. Finally, we provide examples of the various siRNA delivery strategies that have been employed in animal models of HCC and in human patients enrolled in clinical trials. Expert opinion: Despite the existing difficulties in siRNA delivery for HCC, the increasing scientific attention and breakthrough studies in this field is facilitating the design of novel and efficient technical solutions that may soon find practical applications.

Keratin14 mRNA expression in human pneumocytes during quiescence, repair and disease

The lung alveoli slowly self-renew pneumocytes, but their facultative regeneration capacity is rapidly efficient after an injury, so fibrosis infrequently occurs. We recently observed Keratin 14 (KRT14) expression during diffuse alveolar damage (DAD), but not in controls. We wonder if KRT14 may be a marker of pneumocyte transition from quiescence to regeneration. Quantitative PCR and Western blot analyses highlighted the presence of KRT14 (mRNA and protein) only in human lung samples with DAD or interstitial lung disease (ILD). In the exponentially growing cell lines A549 and H441, the mRNA and protein levels of KRT14 peaked at day one after cell seeding and decreased at day two, opposite to what observed for the proliferation marker E2F1. The inverse relation of KRT14 versus E2F1 expression holds true also for other proliferative markers, such as cyclin E1 and cyclin D1. Of interest, we also found that E2F1 silencing caused cell cycle arrest and increased KRT14 expression, whilst E2F1 stimulation induced cell cycle progression and decreased KRT14. KRT14 also increased in proliferative pneumocytes (HPAEpiC) just before transdifferentiation. Overall, our results suggest that KRT14 is a viable biomarker of pneumocyte activation, and repair/regeneration. The involvement of KRT14 in regenerative process may suggest a novel pharmaceutical target to accelerate lung repair.

A novel HMGA1-CCNE2-YAP axis regulates breast cancer aggressiveness

High Mobility Group A1 (HMGA1) is an architectural chromatin factor that promotes neoplastic transformation and progression. However, the mechanism by which HMGA1 exerts its oncogenic function is not fully understood. Here, we show that cyclin E2 (CCNE2) acts downstream of HMGA1 to regulate the motility and invasiveness of basal-like breast cancer cells by promoting the nuclear localization and activity of YAP, the downstream mediator of the Hippo pathway. Mechanistically, the activity of MST1/2 and LATS1/2, the core kinases of the Hippo pathway, are required for the HMGA1- and CCNE2-mediated regulation of YAP localization. In breast cancer patients, high levels of HMGA1 and CCNE2 expression are associated with the YAP/TAZ signature, supporting this connection. Moreover, we provide evidence that CDK inhibitors induce the translocation of YAP from the nucleus to the cytoplasm, resulting in a decrease in its activity. These findings reveal an association between HMGA1 and the Hippo pathway that is relevant to stem cell biology, tissue homeostasis, and cancer.

Aptamer targeting of the elongation factor 1A impairs hepatocarcinoma cells viability and potentiates bortezomib and idarubicin effects

The high morbidity and mortality of hepatocellular carcinoma (HCC) is mostly due to the limited efficacy of the available therapeutic approaches. Here we explore the anti-HCC potential of an aptamer targeting the elongation factor 1A (eEF1A), a protein implicated in the promotion of HCC. As delivery methods, we have compared the effectiveness of cationic liposome and cholesterol-mediated approaches. A75 nucleotide long aptamer containing GT repetition (GT75) was tested in three HCC cell lines, HepG2, HuH7 and JHH6. When delivered by liposomes, GT75 was able to effectively reducing HCC cells viability in a dose and time dependent fashion. Particular sensitive were JHH6 where increased apoptosis with no effects on cell cycle were observed. GT75 effect was likely due to the interference with eEF1A activity as neither the mRNA nor the protein levels were significantly affected. Notably, cholesterol-mediated delivery of GT75 abrogated its efficacy due to cellular mis-localization as proven by fluorescence and confocal microscopic analysis. Finally, liposome-mediated delivery of GT75 improved the therapeutic index of the anticancer drugs bortezomib and idarubicin. In conclusion, liposome but not cholesterol-mediated delivery of GT75 resulted in an effective delivery of GT75, causing the impairment of the vitality of a panel of HCC derived cells.

Therapeutic potential of small interfering RNAs/micro interfering RNA in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the predominant form of primary liver cancer and represents the third leading cause of cancer-related death worldwide. Current available therapeutic approaches are poorly effective, especially for the advanced forms of the disease. In the last year, short double stranded RNA molecules termed small interfering RNAs (siRNAs) and micro interfering RNAs (miRNA), emerged as interesting molecules with potential therapeutic value for HCC. The practical use of these molecules is however limited by the identification of optimal molecular targets and especially by the lack of effective and targeted HCC delivery systems. Here we focus our discussion on the most recent advances in the identification of siRNAs/miRNAs molecular targets and on the development of suitable siRNA/miRNAs delivery systems.

Development of a simple, biocompatible and cost-effective Inulin-Diethylenetriamine based siRNA delivery system

Small interfering RNAs (siRNAs) have the potential to be of therapeutic value for many human diseases. So far, however, a serious obstacle to their therapeutic use is represented by the absence of appropriate delivery systems able to protect them from degradation and to allow an efficient cellular uptake. In this work we developed a siRNA delivery system based on inulin (Inu), an abundant and natural polysaccharide. Inu was functionalized via the conjugation with diethylenetriamine (DETA) residues to form the complex Inu-DETA. We studied the size, surface charge and the shape of the Inu-DETA/siRNA complexes; additionally, the cytotoxicity, the silencing efficacy and the cell uptake-mechanisms were studied in the human bronchial epithelial cells (16HBE) and in the hepatocellular carcinoma derived cells (JHH6). The results presented here indicate that Inu-DETA copolymers can effectively bind siRNAs, are highly cytocompatible and, in JHH6, can effectively deliver functional siRNAs. Optimal delivery is observed using a weight ratio Inu-DETA/siRNA of 4 that corresponds to polyplexes with an average size of 600nm and a slightly negative surface charge. Moreover, the uptake and trafficking mechanisms, mainly based on micropinocytosis and clatrin mediated endocytosis, allow the homogeneous diffusion of siRNA within the cytoplasm of JHH6. Notably, in 16 HBE where the trafficking mechanism (caveolae mediated endocytosis) does not allow an even distribution of siRNA within the cell cytoplasm, no significant siRNA activity is observed. In conclusion, we developed a novel inulin-based siRNA delivery system able to efficiently release siRNA in JHH6 with negligible cytotoxicity thus opening the way for further testing in more complex in vivo models.

Polysaccharides for the Delivery of Antitumor Drugs

Among the several delivery materials available so far, polysaccharides represent very attractive molecules as they can undergo a wide range of chemical modifications, are biocompatible, biodegradable, and have low immunogenic properties. Thus, polysaccharides can contribute to significantly overcome the limitation in the use of many types of drugs, including anti-cancer drugs. The use of conventional anti-cancer drugs is hampered by their high toxicity, mostly depending on the indiscriminate targeting of both cancer and normal cells. Additionally, for nucleic acid based drugs (NABDs), an emerging class of drugs with potential anti-cancer value, the practical use is problematic. This mostly depends on their fast degradation in biological fluids and the difficulties to cross cell membranes. Thus, for both classes of drugs, the development of optimal delivery materials is crucial. Here we discuss the possibility of using different kinds of polysaccharides, such as chitosan, hyaluronic acid, dextran, and pullulan, as smart drug delivery materials. We first describe the main features of polysaccharides, then a general overview about the aspects ruling drug release mechanisms and the pharmacokinetic are reported. Finally, notable examples of polysaccharide-based delivery of conventional anti-cancer drugs and NABDs are reported. Whereas additional research is required, the promising results obtained so far, fully justify further efforts, both in terms of economic support and investigations in the field of polysaccharides as drug delivery materials.

Impairment of the Pin1/E2F1 axis in the anti-proliferative effect of bortezomib in hepatocellular carcinoma cells

BACKGROUND

The modest efficacy of available therapies for Hepatocellular carcinoma (HCC) indicates the need to develop novel therapeutic approaches. For the proteasome inhibitor Bortezomib (BZB), potentially attractive for HCC treatment, the mechanism of action is largely unknown. The BZB effect on E2Fs and the E2Fs control on the peptidylproline cis-trans isomerase (Pin1), prompted us to explore the BZB effect on the Pin1-E2F1 axis.

METHODS

The tumorigenic cell line HuH7 together with the non-tumorigenic cells IHH and the human pluripotent stem cell derived hepatocytes (hPSC-H), were used as cellular models of HCC and normal liver cells, respectively.

RESULTS

BZB reduces HuH7 growth as shown by cell counting, cell vitality test and cell cycle analysis; this is paralleled by the decrease of Pin1, E2F1, cyclin A2 and of the hyper-phosphorylated pRB. Pin1-E2F1 axis impairment justifies the anti-proliferative effect since Pin-E2F1 depletion decreases HuH7 growth while the over-expression rescues BZB-induced inhibition of proliferation. Moreover, Pin1-E2F1 promote HuH7 growth via the up-regulation of cyclin D1, cyclin E, cyclin A2, E2F2 and in part E2F3. Finally, in the control cells IHH and hPSC-H, BZB effect on cell vitality is not irrelevant, a fact correlated to the cellular proliferation rate. Thus, BZB effect on healthy liver tissue may not be entirely negligible hence caution should be exercised in its use in liver regeneration processes.

CONCLUSION

For the first time we prove the functional involvement of the Pin1-E2F1 axis in the anti-proliferative effect of BZB indicating Pin1-E2F as an attractive target to control HCC cell growth.

E2F1 downregulation by arsenic trioxide in lung adenocarcinoma

Lung cancer is one of the most common cancers worldwide. Arsenic trioxide (ATO) has been approved by the US Food and Drug Administration for the treatment of acute promyelocytic leukemia. Nonetheless preliminary data have suggested potential activity of ATO in solid tumors including lung cancer. This study aimed to examine the underlying mechanisms of ATO in the treatment of lung adenocarcinoma. Using a panel of 7 lung adenocarcinoma cell lines, the effects of ATO treatment on cell viability, expression of E2F1 and its downstream targets, phosphatidylserine externalization, mitochondrial membrane depolarization and alteration of apoptotic/anti-apoptotic factors were studied. Tumor growth inhibition in vivo was investigated using a nude mouse xenograft model. ATO decreased cell viability with clinically achievable concentrations (8 µM) in all cell lines investigated. This was accompanied by reduced expression of E2F1, cyclin A2, skp2, c-myc, thymidine kinase and ribonucleotide reductase M1, while p-c-Jun was upregulated. Cell viability was significantly decreased with E2F1 knockdown. Treatment with ATO resulted in phosphatidylserine externalization in H23 cells and mitochondrial membrane depolarization in all cell lines, associated with truncation of Bid, downregulation of Bcl-2, upregulation of Bax and Bak, caspase-9 and -3 activation and PARP cleavage. Using the H358 xenograft model, the tumor growth was suppressed in the ATO treatment group during 8 days of treatment, associated with downregulation of E2F1 and upregulation of truncated Bid and cleaved caspase-3. In conclusion, ATO has potent in vitro and in vivo activity in lung adenocarcinoma, partially mediated through E2F1 downregulation and apoptosis.

Synthesis and characterization of polyaspartamide copolymers obtained by ATRP for nucleic acid delivery

Nucleic acid molecules such as small interfering RNAs (siRNAs) and plasmidic DNAs (pDNAs) have been shown to have the potential to be of therapeutic value in different human diseases. Their practical use is however compromised by the lack of appropriate release systems. Delivered as naked molecules, siRNAs/pDNAs are rapidly degraded by extracellular nucleases thus considerably reducing the amount of molecule which can reach the target cells. Additionally, the anionic charge of the phosphate groups present on the siRNAs/pDNAs backbone, disfavors the interaction with the negatively charged surface of the cell membrane. In this paper we describe the generation of a novel polymer able to deliver both siRNAs and pDNAs. The combined release of these molecules is used in many different experimental settings such as the evaluation of the silencing efficiency of a given siRNA targeted against a given RNA, encoded by the pDNA. The possibility to use the same delivery system is very convenient from the technical point of view and it allows minimizing possible artifacts introduced by the use of different delivery agents for siRNAs and pDNA. The copolymer described here is based on α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) bearing positively chargeable side oligochains, with diethylamino ethyl methacrylate (DEAEMA) as monomer. Monomer polymerization has been obtained by atom transfer radical polymerization (ATRP), a technique which allows the precise polymerization of the monomer. In addition to the chemical-physical characterization of the polymer, we provide evidences of the polymer ability to delivery both siRNAs and pDNA to cultured cells. Whereas additional investigations are necessary to study the delivery mechanisms of this polyplex, the polymer generated represents a novel and convenient device for the delivery of both siRNAs and pDNA.

Bortezomib effect on E2F and cyclin family members in human hepatocellular carcinoma cell lines

AIM

To evaluate the effects of the proteasome inhibitor bortezomib (BZB) on E2Fs and related genes in hepatocellular carcinoma (HCC) cells.

METHODS

The mRNA levels of the E2F family members (pro-proliferative: E2F1-3 and anti-proliferative: E2F4-8) and of their related genes cyclins and cyclin-dependent kinases (cdks) were evaluated in two HCC cell lines following a single BZB administration. mRNA levels of the epithelial-mesenchymal transition (EMT) genes were also measured in both cell lines after BZB treatment. The BZB concentration (40 nmol/L) used was chosen to stay well below the maximal amount/cm² recommended for in vivo application, and 2 d incubation was chosen as this time point has been found optimal to detect BZB effects in our previous studies. The HCC cell lines, HepG2 and JHH6, were chosen as they display different phenotypes, hepatocyte-like for HepG2 and undifferentiated for JHH6, thus representing an in vitro model of low and high aggressive forms of HCC, respectively. The mRNA levels of the target genes were measured by two-color microarray-based gene expression analysis, performed according to Agilent Technologies protocol and using an Agilent Scan B. For the E2F family members, mRNA levels were quantified by real-time reverse transcription polymerase chain reaction (RT-PCR). Using small interfering RNA's, the effects of E2F8 depletion on cell number was also evaluated.

RESULTS

After BZB treatment, microarray analysis of the undifferentiated JHH6 revealed a significant decrease in the expression of the pro-proliferative E2F member E2F2. Quantitative RT-PCR data were in keeping with the microarray analysis, and showed a significant increase and decrease in E2F8 and E2F2 mRNA levels, respectively. In contrast, BZB treatment of the hepatocyte-like HCC cell line HepG2 had a significant impact on mRNA levels of 5 of the 8 E2F members. In particular, mRNA levels of the pro-proliferative E2F members E2F1, E2F2, and of the anti-proliferative member E2F8, decreased over 80%. Notably, a reduction in E2F8 expression in HepG2 and JHH6 cells following siRNA treatment had no impact on cell proliferation. As observed with JHH6, BZB treatment of HepG2 cells induced a significant increase in mRNA levels of an anti-proliferative E2F member, E2F6 in this case. As was observed with E2F's, more dramatic changes in mRNA levels of the E2F related genes cyclins and Cdks and EMT genes were observed after BZB treatment of HepG2 compared to JHH6.

CONCLUSION

The differential expression of E2Fs and related genes induced by BZB in diverse HCC cell phenotypes contribute to bortezomib's mechanism of action in hepatocellular carcinoma.

RITA inhibits growth of human hepatocellular carcinoma through induction of apoptosis

RBP-J-interacting and tubulin-associated (RITA) is a novel RBP-J-interacting protein that downregulates Notch-mediated transcription. The current study focuses on the antitumor effect of RITA in human hepatocellular carcinoma (HCC) and aims to explore its molecular mechanism. Thirty paired HCC and adjacent non-tumoral liver samples were analyzed by real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). RITA overexpression was induced by transfection of a pcDNA3.1-Flag-RITA plasmid into HepG2 cells. RITA knockdown was achieved by siRNA transfection. mRNA and protein expression of target genes were quantified by qRT-PCR and Western blotting, respectively. Cell proliferation and apoptosis were measured using MTT assay and flow cytometry. Our results demonstrate that adjacent nontumoral liver samples exhibited increased RITA expression compared to HCC tissues (p < 0.05); RITA levels were associated with tumor differentiation status. Overexpression of RITA suppressed cell proliferation and promoted early apoptosis, while its silencing promoted cell growth dramatically (p < 0.05). RITA overexpression upregulated p53 and reduced cyclin E levels, whereas silencing of RITA had the opposite effect on p53 and cyclin E expression. Our in vitro results represent the first evidence that RITA might suppress tumor growth and induce apoptosis in HCCs, and may be a potent antitumoral agent for HCC treatment that deserves further exploration.

Reversing multidrug-resistant by RNA interference through silencing MDR1 gene in human hepatocellular carcinoma cells subline Bel-7402/ADM

Multidrug resistance (MDR) in hepatocellular carcinoma (HC) significantly impedes the effect of chemotherapy and is considered as a primary reason leading to its recurrences and metastasis. The aim of present study was to explore new molecular targets for the reversal of MDR in HC by screening the adriamycin (ADM)-induced, human MDR-resistant HC cell subline Bel-7402/ADM. Small interfering RNAs (siRNAs) of four (MDR1si326, MDR1si1513, MDR1si2631 and MDR1si3071) targeting MDR1 were designed and transfected into Bel-7402/ADM cell strains. The experiments involved the following: mRNA expression of MDR1 gene by RT-PCR, P-glycoprotein (P-gp) expression by Western blot, intracellular ADM accumulation flow cytometry, and IC50 of ADM by a cytotoxic MTT assay. Four siRNAs reversed MDR in HC mediated by MDR1 to varying degrees. The expression level of MDR1 mRNA in cells of MDR1si326 or MDR1si2631 group (0.190 ± 0.038 or 0.171 ± 0.011) was more decreased. The expression level of P-gp in cells of MDR1si326 group was the lowest. The accumulation of ADM in cells of MDR1si326 or MDR1si2631 group (77.0 ± 3.5 or 75.4 ± 2.9) was more increased. The IC50 of cells to ADM was lowest in MDR1si326 group (11.32 ± 0.69 mg/L). Compared with other three siRNAs, MDR1si326 performed the optimal reversal effect of drug resistance in human HC Bel-7402/ADM.

The more basic isoform of eEF1A relates to tumour cell phenotype and is modulated by hyper-proliferative/differentiating stimuli in normal lymphocytes and CCRF-CEM T-lymphoblasts

The elongation factor 1A proteins (eEF1A1/A2) are known to play a role in tumours. We previously found that a more basic isoform of eEF1A (MBI-eEF1A) is present in the cytoskeletal/nuclear-enriched extracts of CCRF-CEM T-lymphoblasts but not in those of normal lymphocytes. To obtain deeper knowledge about MBI-eEF1A biology, we investigate from which of the eEF1A proteins, eEF1A1 or eEF1A2, MBI-eEF1A originates and the possibility that its appearance can be modulated by the differentiated or proliferative cell status. CCRF-CEM T-lymphoblasts and normal lymphocytes were cultured with or without differentiation/pro-proliferative stimuli (Phorbol 12-Myristate 13-Acetate (PMA) alone or the combination of phytohaemagglutinin (PHA) with PMA, respectively), and the presence of MBI-eEF1A evaluated together with that of the eEF1A1/A2 mRNAs. Our data indicate that the MBI-eEF1A may derive from eEF1A1 as eEF1A2 is not expressed in CCRF-CEM and normal lymphocytes. Moreover, MBI-eEF1A is inducible in normal lymphocytes upon hyper-proliferative stimuli application; in CCRF-CEM, its presence can be abrogated by PMA-induced differentiation. Finally, MBI-eEF1A may have a functional role in hyper-proliferating/tumour cells as its disappearance reduces the growth of CCRF-CEM and that of PHA/PMA-stimulated lymphocytes. The presented data suggest that MBI-eEF1A may be related to oncogenic cell phenotype, rising the possibility to use MBI-eEF1A as target for novel therapeutic strategies.

RNA-Seq profiling reveals novel hepatic gene expression pattern in aflatoxin B1 treated rats

Deep sequencing was used to investigate the subchronic effects of 1 ppm aflatoxin B1 (AFB1), a potent hepatocarcinogen, on the male rat liver transcriptome prior to onset of histopathological lesions or tumors. We hypothesized RNA-Seq would reveal more differentially expressed genes (DEG) than microarray analysis, including low copy and novel transcripts related to AFB1’s carcinogenic activity compared to feed controls (CTRL). Paired-end reads were mapped to the rat genome (Rn4) with TopHat and further analyzed by DESeq and Cufflinks-Cuffdiff pipelines to identify differentially expressed transcripts, new exons and unannotated transcripts. PCA and cluster analysis of DEGs showed clear separation between AFB1 and CTRL treatments and concordance among group replicates. qPCR of eight high and medium DEGs and three low DEGs showed good comparability among RNA-Seq and microarray transcripts. DESeq analysis identified 1,026 differentially expressed transcripts at greater than two-fold change (p<0.005) compared to 626 transcripts by microarray due to base pair resolution of transcripts by RNA-Seq, probe placement within transcripts or an absence of probes to detect novel transcripts, splice variants and exons. Pathway analysis among DEGs revealed signaling of Ahr, Nrf2, GSH, xenobiotic, cell cycle, extracellular matrix, and cell differentiation networks consistent with pathways leading to AFB1 carcinogenesis, including almost 200 upregulated transcripts controlled by E2f1-related pathways related to kinetochore structure, mitotic spindle assembly and tissue remodeling. We report 49 novel, differentially-expressed transcripts including confirmation by PCR-cloning of two unique, unannotated, hepatic AFB1-responsive transcripts (HAfT’s) on chromosomes 1.q55 and 15.q11, overexpressed by 10 to 25-fold. Several potentially novel exons were found and exon refinements were made including AFB1 exon-specific induction of homologous family members, Ugt1a6 and Ugt1a7c. We find the rat transcriptome contains many previously unidentified, AFB1-responsive exons and transcripts supporting RNA-Seq’s capabilities to provide new insights into AFB1-mediated gene expression leading to hepatocellular carcinoma.