Efficient Inhibition of Ovarian Cancer by Truncation Mutant of FILIP1L Gene Delivered by Novel Biodegradable Cationic Heparin-Polyethyleneimine Nanogels

An insight of nanogels as novel drug delivery system with potential hybrid nanogel applications

Nanogels are cross-linked, nano-sized hydrogels with dimensions ranging from 20 to 200 nm. Nanogel-based nanoplatforms have proven to be an excellent choice for pharmaceutical formulations. Nanosystems have properties that are very useful in polymeric drug delivery applications, and their particular strength is that they have these nanosystemic properties and can thus merge with polymeric materials. Drug-carrier size is designed to be nano-sized in order to maintain optimal stability, resulting in more surface area and interior space. This also allows for a prolonged period of time for loaded pharmaceuticals to circulate. They can be classified by stimuli responsive or non-responsive behavior and type of linkages present in the network chains of gel structure. Nanogel can be synthesized by Photolithographic, modified pullulan, emulsion polymerization reverse microemulsion polymerization inverse miniemulsion polymerization and free radical crosslinking polymerization technique. Hybrid nanogels are different from conventional polymer nanoparticles often employed for drug administration. They can encapsulate bioactive medicines and regulate the release of such medications over time and in particular areas. The hybrid nanogels used to create a specific form of the hybrid, especially one geared towards increasing targeted drug delivery, enhance the effectiveness of ailment treatments, but perhaps the introduction of a multifunctional nanogel-based drug delivery system.

Clinically relevant aberrant Filip1l DNA methylation detected in a murine model of cutaneous squamous cell carcinoma

BACKGROUND

Cutaneous squamous cell carcinomas (cSCC) are among the most common and highly mutated human malignancies. Understanding the impact of DNA methylation in cSCC may provide avenues for new therapeutic strategies.

METHODS

We used reduced-representation bisulfite sequencing for DNA methylation analysis of murine cSCC. Differential methylation was assessed at the CpG level using limma. Next, we compared with human cSCC Infinium HumanMethylation BeadArray data. Genes were considered to be of major relevance when they featured at least one significantly differentially methylated CpGs (RRBS) / probes (Infinium) with at least a 30% difference between tumour vs. control in both a murine gene and its human orthologue. The human EPIC Infinium data were used to distinguish two cSCC subtypes, stem-cell-like and keratinocyte-like tumours.

FINDINGS

We found increased average methylation in mouse cSCC (by 12.8%, p = 0.0011) as well as in stem-cell like (by 3.1%, p=0.002), but not keratinocyte-like (0.2%, p = 0.98), human cSCC. Comparison of differentially methylated genes revealed striking similarities between human and mouse cSCC. Locus specific methylation changes in mouse cSCC often occurred in regions of potential regulatory function, including enhancers and promoters. A key differentially methylated region was located in a potential enhancer of the tumour suppressor gene Filip1l and its expression was reduced in mouse tumours. Moreover, the FILIP1L locus showed hypermethylation in human cSCC and lower expression in human cSCC cell lines.

INTERPRETATION

Deregulation of DNA methylation is an important feature of murine and human cSCC that likely contributes to silencing of tumour suppressor genes, as shown for Filip1l.

FUNDING

British Skin Foundation, Cancer Research UK.

Association of coding and UTR variants in the known regions with wet age-related macular degeneration in Han Chinese population

Age-related macular degeneration (AMD) is the leading cause worldwide of severe visual impairment among people older than 55 years of age. This study aimed to investigate the genetic association between coding and untranslated region (UTR) variants in previously reported loci and exudative age-related macular degeneration (wet AMD) in a Han Chinese population. Using our previously published whole exome sequencing dataset of 349 wet AMD patients and 1253 controls, we searched for associations between coding and UTR variants of the 72 genes located within the 47 reported wet AMD loci regions. From these, 25 variants in 18 of the 72 genes with P < 10 × 10^-3 were selected for the first replication of Sequenom mass-array genotyping in 885 wet AMD subjects and 562 controls. Next, four SNPs were selected for further validation by SNaPshot genotyping in a third Chinese cohort with 456 wet AMD subjects and 211 controls. As a result, we identified two new potential coding and UTR variant SNPs (rs189132250 in BBX located in 3q12.1 and rs144351944 in FILIP1L located in 3q12.1) that showed weak associations with wet AMD in the Han Chinese population. These findings provide new information regarding the coding and UTR variants of the known wet AMD loci in the studied Chinese cohort.

Filamin A interacting protein 1-like expression inhibits progression in colorectal cancer

Filamin A interacting protein 1-like (FILIP1L) expression, which is decreased in various cancers, may inhibit carcinogenesis. In this study, we evaluated the effects of FILIP1L on oncogenic behavior and prognosis in colorectal cancer. siRNA-mediated FILIP1L knockdown enhanced tumor cell migration and invasion and inhibited apoptosis and cell cycle arrest in COLO205 cells. pcDNA-myc vector-mediated FILIP1L overexpression suppressed tumor cell migration and invasion and induced apoptosis and cell cycle arrest in HCT116 cells. FILIP1L knockdown enhanced angiogenesis by increasing VEGF-A and HIF-1α levels and decreasing angiostatin level. FILIP1L overexpression suppressed angiogenesis by decreasing VEGF-A and -D l level and increasing angiostatin and endostatin levels. Phosphorylated β-catenin levels decreased and phosphorylated Akt and GSK-3β levels increased following FILIP1L knockdown. FILIP1L overexpression had the opposite effects. FILIP1L expression was associated with reductions in tumor size, cell differentiation, lymphovascular invasion, stage, invasion depth and lymph node metastasis, and with longer overall survival. Mean Ki-67 labeling indexes and microvessel density values were lower in FILIP1L-positive tumors than in FILIP1L-negative tumors. These results indicate that FILIP1L suppresses tumor progression by inhibiting cell proliferation and angiogenesis in colorectal cancer.

Enhanced antitumor effect of biodegradable cationic heparin-polyethyleneimine nanogels delivering FILIP1LΔC103 gene combined with low-dose cisplatin on ovarian cancer

FILIP1LΔC103 (COOH terminal truncation mutant 1-790 of Filamin A Interacting Protein 1-Like) has been identified to hold therapeutic potential for suppressing tumor growth. Cisplatin (DDP) is commonly used as a first-line drug in the treatment for ovarian cancer. The usage of polymeric nanoparticles to deliver functional genes intraperitoneally holds much promise as an effective therapy for ovarian cancer. In this study, a recombinant plasmid expressing FILIP1LΔC103 (FILIP1LΔC103-p) was constructed, and HPEI nanogels were prepared to deliver FILIP1LΔC103-p into SKOV3 cells. The expression of FILIP1LΔC103 in vitro and in vivo was determined using RT-PCR and Western Blotting. Moreover, in vivo treatment experiments were conducted on nude mice bearing SKOV3 ovarian cancer. The mice were treated with 5% glucose, HPEI+E-p, HPEI+FILIP1LΔC103-p, DDP or HPEI+FILIP1LΔC103-p plus DDP, respectively. Tumor weights were evaluated throughout the treatment duration. The cell proliferation and apoptosis were evaluated by Ki-67 immunochemical staining and TUNEL assay respectively, and the anti-angiogenic effect was assessed by CD31 immunochemical staining and alginate-encapsulated tumor cell assay. FILIP1LΔC103-p could be efficiently transfected into SKOV3 cells by HPEI nanogels. The combination of HPEI+FILIP1LΔC103-p with DDP exerted enhanced antitumor activity compared with HPEI+FILIP1LΔC103-p or DDP alone. Significant reduction of tumor cells proliferation, augmentation of tumor cells apoptosis and suppression of angiogenesis were observed in the combination group compared with controls. Our results demonstrated synergistic antineoplastic activity of combined FILIP1LΔC103 and low-dose DDP with no apparent toxicity, indicating a potential application of the combined approach in the treatment of ovarian cancer.

Efficient Inhibition of Ovarian Cancer by Gelonin Toxin Gene Delivered by Biodegradable Cationic Heparin-polyethyleneimine Nanogels

The use of toxins for cancer therapy has great promise. Gelonin, a potent plant toxin, causes cell death by inactivating the 60S ribosomal subunit. Recently, we developed a novel gene delivery system using biodegradable cationic heparin-polyethyleneimine (HPEI) nanogels. In the current study, the antitumor activity of a recombinant plasmid expressing gelonin (pGelonin) on human ovarian cancer was assessed. The application of HPEI nanogels, was also evaluated. Gelonin-cDNA was cloned into the pVAX1 plasmid vector and transfected into SKOV3 human ovarian cancer cells using biodegradable cationic HPEI nanogels. The expression of gelonin in vitro and in vivo was confirmed using RT-PCR and western blot analysis. Cell viability and apoptosis were examined using an MTT assay and flow cytometric analysis. For the in vivo study, an SKOV3 intraperitoneal ovarian carcinomatosis model was established, and nude mice were randomly assigned into four groups receiving i.p. administration of pGelonin/HPEI complexes, pVAX/HPEI complexes, HPEI alone and 5% glucose solution. The tumor weight was monitored, and a TUNEL assay and Ki-67 immunohistochemistry were performed to evaluate apoptosis and cell proliferation in the tumor tissue sections, respectively. Gelonin was efficiently expressed in SKOV3 cancer cells in vitro and in vivo using pGelonin incorporated with HPEI nanogels. The pGelonin/HPEI complexes inhibited cell viability and induced apoptosis in the cell culture. Treatment for intraperitoneal carcinomatosis with pGelonin/HPEI complexes reduced the tumor weight by ~58.55% compared to the control groups (P<0.05). The antitumor effect was accompanied by increased apoptosis and reduced cell proliferation (P<0.05). No significant side effects were observed with i.p. administration of the pGelonin/HPEI complexes. Our data indicate that HPEI nanogel-delivered pGelonin may have promising applications against human ovarian cancer.

Development of nanoscale approaches for ovarian cancer therapeutics and diagnostics

Ovarian cancer is the deadliest of all gynecological cancers and the fifth leading cause of death due to cancer in women. This is largely due to late-stage diagnosis, poor prognosis related to advanced-stage disease, and the high recurrence rate associated with development of chemoresistance. Survival statistics have not improved significantly over the last three decades, highlighting the fact that improved therapeutic strategies and early detection require substantial improvements. Here, we review and highlight nanotechnology-based approaches that seek to address this need. The success of Doxil, a PEGylated liposomal nanoencapsulation of doxorubicin, which was approved by the FDA for use on recurrent ovarian cancer, has paved the way for the current wave of nanoparticle formulations in drug discovery and clinical trials. We discuss and summarize new nanoformulations that are currently moving into clinical trials and highlight novel nanotherapeutic strategies that have shown promising results in preclinical in vivo studies. Further, the potential for nanomaterials in diagnostic imaging techniques and the ability to leverage nanotechnology for early detection of ovarian cancer are also discussed.

Filamin A interacting protein 1-like inhibits WNT signaling and MMP expression to suppress cancer cell invasion and metastasis

Identifying key mediators of cancer invasion and metastasis is crucial to the development of new and more effective therapies. We previously identified FILamin A Interacting Protein 1-Like (FILIP1L) as an important inhibitor of cell migration and invasion. FILIP1L expression was inversely correlated with the invasive potential of ovarian tumors. In our study, we established an orthotopic ovarian cancer model, wherein FILIP1L expression can be regulated in vivo. Using this model, we observed that expression of FILIP1L in ovarian cancer cells inhibited spontaneous lung metastasis. Experimental lung metastases (established via tail vein injection of cancer cells) as well as the extravasation step of metastasis were not inhibited by FILIP1L, suggesting that FILIP1L inhibits the earlier steps of metastasis such as invasion and intravasation. FILIP1L inhibited matrix metalloproteinase (MMP)-dependent invasion in vivo. MMP3, -7 and -9 were transcriptionally downregulated, and MMP9 protein expression and activity were inhibited in FILIP1L-expressing tumors. Importantly, overexpression of MMP9 compensated for the anti-invasive activity of FILIP1L. Furthermore, our studies suggest that FILIP1L regulates invasion and metastasis by inhibiting components of the WNT signaling pathway. FILIP1L expression reduced the induction of WNT target genes such as MMP3, -7 and -9, and β-catenin-directed transcriptional activity, suggesting inhibition of the canonical WNT pathway. Nuclear β-catenin, an indicator of an active canonical WNT pathway, was reduced in FILIP1L-expressing tumors. Overall, these findings suggest that FILIP1L reduces β-catenin levels, which may lead to the transcriptional downregulation of WNT target genes such as MMPs, resulting in inhibition of metastasis. Modulation of FILIP1L expression has the potential to be a target for cancer therapy.

Down-regulation of Filamin A interacting protein 1-like Is associated with promoter methylation and an invasive phenotype in breast, colon, lung and pancreatic cancers [corrected]

Identifying key mediators of cancer cell invasion and metastasis is critical to the development of more effective cancer therapies. We previously identified Filamin A interacting protein 1-like (FILIP1L) as an important inhibitor of cell migration and invasion in ovarian cancer. FILIP1L expression was inversely correlated with the invasive potential of ovarian cancer cell lines and ovarian cancer specimens. We also demonstrated that DNA methylation in the FILIP1L promoter was a mechanism by which FILIP1L was down-regulated in ovarian cancer. In our present study, we tested this observation in other cancer histologies: breast, colon, lung and pancreatic cancers. Both mRNA and protein expression of FILIP1L were down-regulated in these cancer cells compared with their normal epithelial cells. As in ovarian cancer, DNA methylation is a mechanism by which FILIP1L is down-regulated in these cancer histologies. Methylation status of the FILIP1L promoter was inversely correlated with FILIP1L expression. Reduced methylation in the FILIP1L promoter following treatment with a DNA demethylating agent was associated with restoration of FILIP1L expression in these cancer cells. Further, FILIP1L expression was inversely correlated with the invasive potential of these cancer cells. Re-expression of FILIP1L in FILIP1L-low expressing, highly-invasive cancer cell lines resulted in inhibition of cell invasion. Correspondingly, knockdown of FILIP1L in FILIP1L-high expressing, low-invasive cancer cell lines resulted in increase of cell invasion. Overall, these findings suggest that down-regulation of FILIP1L associated with DNA methylation is related with the invasive phenotype in various cancers. Thus, modulation of FILIP1L expression has the potential to be a target for cancer therapy.

Intraperitoneal delivery of nanoparticles for cancer gene therapy

Nanoparticle-based gene delivery systems may be more efficient for administration of therapeutic genes to solid tumors and cancer metastases, owing to the numerous advantages in terms of enhanced tissue penetrability, improved cellular uptake and targeted gene delivery to the cells of interest compared with other gene delivery systems. Intraperitoneal (IP) delivery of therapeutic agents offers special merits because of the anatomical situation of peritoneum for local cancer therapy. Via the IP administration route, it is possible to target the therapeutic agents exactly to the target cells and protect healthy tissues outside the peritoneal cavity from side effects. IP delivery could be applicable for the treatment of disorders of organs in the peritoneal cavity covered with peritoneum and subperitoneal connective tissue, including cancers such as ovarian and gastric. The goal of this article is to review the current state of IP delivery of nanoparticles for cancer gene therapy.

Efficient inhibition of ovarian cancer by recombinant CXC chemokine ligand 10 delivered by novel biodegradable cationic heparin-polyethyleneimine nanogels

Currently, great interest is focused on the anti-neoplastic effects of CXC chemokine ligand 10 (IP-10/CXCL10). IP-10 has shown significant antitumor and anti-metastatic properties via immunological, antiangiogenic and anti-neoplastic mechanisms. However, very few studies on the antitumor activity of IP-10 in human ovarian cancer have been reported. The use of polymeric nanoparticles to deliver functional genes intraperitoneally holds much promise as an effective therapy for ovarian cancer. In our study, a recombinant plasmid expressing IP-10 (pVITRO-IP-10) was constructed, and biodegradable cationic heparin-polyethyleneimine (HPEI) nanogels were prepared to deliver pVITRO-IP-10 into SKOV3 human ovarian cancer cells. Transfection efficiency was detected by expression profiling of green fluorescent protein. The expression of IP-10 was determined using RT-PCR and western blot analysis. In vitro, cell proliferation was evaluated by MTT assay. Apoptosis was examined by Hoechst33258/PI staining and flow cytometry assays. The effect on the inhibition of angiogenesis was evaluated by tube formation assay using human umbilical vein endothelial cells (HUVECs). Moreover, a SKOV3 intraperitoneal ovarian carcinomatosis model was established to investigate the antitumor activity of HPEI+pVITRO-IP-10 complexes in nude mice. Tumor weights were evaluated during the treatment course. Cell proliferation and apoptosis were evaluated by Ki-67 immunochemical staining and TUNEL assay, and the antiangiogenic effect of pVITRO-IP-10 was assessed by CD31 immunochemical staining and alginate-encapsulated tumor cell assay. pVITRO-IP-10 was efficiently transfected into SKOV3 cells by HPEI nanogels. Intraperitoneal administration of HPEI+pVITRO-IP-10 complexes led to effective growth inhibition of ovarian cancer, in which tumor weight decreased by ~69.92% in the treatment group compared with that in the empty vector control group. Meanwhile, decreased cell proliferation, increased tumor cell apoptosis and reduction in angiogenesis were observed in the HPEI+pVITRO-IP-10 group compared with those in the control groups. These results indicated that HPEI nanogel delivery of pVITRO-IP-10 may be of value in the treatment against human ovarian cancer.