Atelocollagen-mediated intravenous siRNA delivery specific to tumor tissues orthotopically xenografted in prostates of nude mice and its anticancer effects

The Delivery of Mimic miRNA-7 into Glioblastoma Cells and Tumour Tissue by Graphene Oxide Nanosystems

Purpose

The use of nanotechnology in medicine has gained attention in developing drug delivery systems. GO has the potential to deliver microRNA (miRNA) mimics or antisense structures. MiRNAs regulate gene expression and their dysregulation is implicated in diseases, including cancer. This study aims to observe changes in morphology, viability, mRNA expression of mTOR/PI3K/Akt and PTEN genes in U87, U118, U251, A172 and T98 glioblastoma cells and xenograft models after GO self-assembly with mimic miRNA-7.

Methods

Colloidal suspension of graphene oxide (GO) was used for obtaining the GO-mimic miRNA-7 nanosystems by self-assembly method. The ultrastructure, size distribution and ATR-FTIR and UV-Vis spectrum were analyzed. The Zeta potential was measured to verify the stability of obtained nanosystem. The entrapment efficiency, loading capacity and released kinetics of mimic miRNA-7 form GO-mimic miRNA-7 nanosystems were analyzed. The transfection efficiency into the glioblastoma cell lines U87, U118, U251, A172 and T98 of mimic miRNA-7 delivered by GO nanosystems was measure by confocal microscopy and flow cytometry. The changes at mRNA expression level of mTOR, PI3K, AKT1 and PTEN genes was measured by qPCR analysis. The xenograft model of U87 and A172 tumour tissue was performed to analyze the effect at tumor size and volume after GO- mimic miRNA-7 nanosystem administration.

Results

The ultrastructure of GO-mimic miRNA-7 nanosystems showed high affinity of mimic miRNA into the GO. The results of transfection efficiency, cell morphology and viability showed that GO -miRNA-7 effectively deliver mimics miRNA-7 into U87, U118, U251, A172 and T98 glioblastoma cells. This approach can reverse miRNA-7 expression's downstream effects and target the mTOR PI3K/Akt pathway observed at gene expression level, reducing xenograft tumour size and volume.

Conclusion

The findings of the study could have significant implications for the development of advanced and precise GO based nanosystems specifically designed for miRNA therapy in cancer treatment.

Long Noncoding RNA HOTAIR Promotes Epithelial-Mesenchymal Transition and Is a Suitable Target to Inhibit Peritoneal Dissemination in Human Scirrhous Gastric Cancers

OBJECTIVES

Scirrhous gastric cancer, which accounts for approximately 10% of all gastric cancers, often disseminates to the peritoneum, leading to intractable cases with poor prognosis. There is an urgent need for new treatment approaches for this difficult cancer.

METHODS

We previously established an original cell line, HSC-60, from a scirrhous gastric cancer patient and isolated a peritoneal-metastatic cell line, 60As6, in nude mice following orthotopic inoculations. In the present study, we focused on the expression of long noncoding ribonucleic acid (RNA) (lncRNA) in the cell lines and investigated the mechanism on peritoneal dissemination.

RESULTS

We demonstrated that an lncRNA, HOX transcript antisense RNA (HOTAIR), is expressed significantly more highly in 60As6 than HSC-60 cells. Then, using both HOTAIR knockdown and overexpression experiments, we showed that high-level expression of HOTAIR promotes epithelial-mesenchymal transition (EMT) in 60As6 cells. By luciferase assay, we found that HOTAIR directly targets and binds to miR-217, and that miR-217 directly binds to Zinc finger E-box-binding homeobox 1 (ZEB1). The knockdown of HOTAIR in 60As6 cells significantly reduced the invasion activity and peritoneal dissemination - and significantly prolonged the survival - in the orthotopic tumor mouse model.

CONCLUSION

An EMT-associated pathway (the HOTAIR-miR-217-ZEB1 axis) appears to inhibit peritoneal dissemination and could lead to a novel therapeutic strategy against scirrhous gastric cancer in humans.

Progress in Delivery of siRNA-Based Therapeutics Employing Nano-Vehicles for Treatment of Prostate Cancer

Prostate cancer (PCa) accounts for a high number of deaths in males with no available curative treatments. Patients with PCa are commonly diagnosed in advanced stages due to the lack of symptoms in the early stages. Recently, the research focus was directed toward gene editing in cancer therapy. Small interfering RNA (siRNA) intervention is considered as a powerful tool for gene silencing (knockdown), enabling the suppression of oncogene factors in cancer. This strategy is applied to the treatment of various cancers including PCa. The siRNA can inhibit proliferation and invasion of PCa cells and is able to promote the anti-tumor activity of chemotherapeutic agents. However, the off-target effects of siRNA therapy remarkably reduce its efficacy in PCa therapy. To date, various carriers were designed to improve the delivery of siRNA and, among them, nanoparticles are of importance. Nanoparticles enable the targeted delivery of siRNAs and enhance their potential in the downregulation of target genes of interest. Additionally, nanoparticles can provide a platform for the co-delivery of siRNAs and anti-tumor drugs, resulting in decreased growth and migration of PCa cells. The efficacy, specificity, and delivery of siRNAs are comprehensively discussed in this review to direct further studies toward using siRNAs and their nanoscale-delivery systems in PCa therapy and perhaps other cancer types.

siRNA-Based Drug Targeting Human Bcl-xL Against Cancers

The 2006 discovery of the process of RNA interference opened the door to application of this phenomenon for disease treatments. Short interfering RNA (siRNA) can be used to induce RNA interference, and this approach has generated much interest as a new type of nucleic acid-based drugs in humans and other mammals. However, despite the great potential of siRNA-based drugs in cancer therapy, some drawbacks of siRNAs, such as their instability in vivo and poor cellular uptake, remain unresolved. Here, we review the development of siRNA-based drugs targeting the human Bcl-xL gene, an anti-apoptotic factor overexpressed in many cancers, including prostate cancers. We also introduce a novel application of the biomaterial atelocollagen as a vehicle to functionally deliver tumor-specific siRNA molecules in nude mice. Here, we introduce an orthotopic tumor inoculation model in nude mice: the resulting orthotopic tumors more closely replicate the clinical conditions in humans-including the metastasis mode-than ectopic subcutaneously inoculated tumors.

MicroRNAs Associated with Epithelial-Mesenchymal Transition Can Be Targeted to Inhibit Peritoneal Dissemination of Human Scirrhous Gastric Cancers

OBJECTIVES

Scirrhous gastric cancers grow rapidly, and frequently invade the peritoneum. Such peritoneal dissemination properties markedly reduce patient survival. Thus, an effective means for inhibiting peritoneal dissemination is urgently required.

METHODS

We previously established a cell line, HSC-58, from a scirrhous gastric cancer patient, and further successfully isolated a metastatic line, 58As9, in nude mice upon orthotopic inoculation. Using the lines, we examined the mechanism underlying peritoneal dissemination from the viewpoint of microRNA (miRNA) expression.

RESULTS

miRNA array and qRT-PCR analysis showed that the expressions of epithelial-mesenchymal transition (EMT)-associated miRNAs such as miR-200c and miR-141 were significantly low in 58As9. Using 58As9 with stably overexpressing miR-200c, miR-141, or both, together with a luciferase reporter assay, we found that miR-200c targeted zinc finger E-box-binding homeobox 1 (ZEB1) and miR-141 targeted ZEB2. The overexpressed lines reversed the EMT status from mesenchymal to epithelial in 58As9, and significantly reduced the invasion activity and peritoneal dissemination for a significant prolongation of survival in the orthotopic tumor models in nude mice.

CONCLUSIONS

EMT-associated miRNAs such as miR-200c and miR-141 and their target genes ZEB1/ZEB2 have good potential for antiperitoneal dissemination therapy in patients with scirrhous gastric cancers.

Theranostic hollow/mesoporous organosilica nanospheres enhance the therapeutic efficacy of anticancer drugs in metastatic hormone-resistant prostate cancer

Hollow mesoporous silica materials have received intensive interest in the field of cancer treatment owing to their large drug loading capacity, controlled release property and excellent biocompatibility.

siRNA Versus miRNA as Therapeutics for Gene Silencing

Discovered a little over two decades ago, small interfering RNAs (siRNAs) and microRNAs (miRNAs) are noncoding RNAs with important roles in gene regulation. They have recently been investigated as novel classes of therapeutic agents for the treatment of a wide range of disorders including cancers and infections. Clinical trials of siRNA- and miRNA-based drugs have already been initiated. siRNAs and miRNAs share many similarities, both are short duplex RNA molecules that exert gene silencing effects at the post-transcriptional level by targeting messenger RNA (mRNA), yet their mechanisms of action and clinical applications are distinct. The major difference between siRNAs and miRNAs is that the former are highly specific with only one mRNA target, whereas the latter have multiple targets. The therapeutic approaches of siRNAs and miRNAs are therefore very different. Hence, this review provides a comparison between therapeutic siRNAs and miRNAs in terms of their mechanisms of action, physicochemical properties, delivery, and clinical applications. Moreover, the challenges in developing both classes of RNA as therapeutics are also discussed.