Oncogenic signaling in tumorigenesis and applications of siRNA nanotherapeutics in breast cancer

Overexpression of oncogenes and cross-talks of the oncoproteins-regulated signaling cascades with other intracellular pathways in breast cancer could lead to massive abnormal signaling with the consequence of tumorigenesis. The ability to identify the genes having vital roles in cancer development would give a promising therapeutics strategy in combating the disease. Genetic manipulations through siRNAs targeting the complementary sequence of the oncogenic mRNA in breast cancer is one of the promising approaches that can be harnessed to develop more efficient treatments for breast cancer. In this review, we highlighted the effects of major signaling pathways stimulated by oncogene products on breast tumorigenesis and discussed the potential therapeutic strategies for targeted delivery of siRNAs with nanoparticles in suppressing the stimulated signaling pathways

Cytotoxic, antiproliferative and apoptosis-inducing activity of L-amino acid oxidase from Malaysian Calloselasma rhodostoma on human colon cancer cells

The aim of this study was to investigate the cytotoxic, antiproliferative activity and the induction of apoptosis by L-amino acid oxidase isolated from Calloselasma rhodostoma crude venom (CR-LAAO) on human colon cancer cells. CR-LAAO was purified using three chromatographic steps: molecular exclusion using G-50 gel filtration resin, ion-exchange by MonoQ columnand desalted on a G25 column. The purity and identity of the isolated CR-LAAO was confirmed by SDS-PAGE and LC-MS/MS. CR-LAAO demonstrated time- and dose-dependent cytotoxic activity on SW480 (primary human colon cancer cells) andSW620 (metastatic human colon cancer cells) with an EC50 values of 6 lg/ml and 7 lg/ml at 48 hr, respectively. Quantification of apoptotic cells based on morphological features demonstrated significant increase in apoptotic cell population in both SW480 and SW620 cells which peaked at 48 hr. Significant increase in caspase-3 activity and reduction in Bcl-2 levels were demonstrated following CR-LAAO treatment. These data provide evidence on the potential anticancer activity of CR-LAAO from the venom of C. rhodostoma for therapeutic intervention of human colon cancer

Cytotoxicity Enhancement in Breast Cancer Cells with Carbonate Apatite-Facilitated Intracellular Delivery of Anti-Cancer Drugs

Pharmacotherapy as the mainstay in the management of breast cancer has demonstrated various drawbacks, including non-targeted bio distribution and narrow therapeutic and safety windows. Thus, enhancements in pharmacodynamic and pharmacokinetic profiles of the classical anti-cancer drugs could lead to improved efficacy against cancer cells. Therefore, inorganic pH-dependent carbonate apatite (CA) nanoparticles were utilized to efficiently deliver various drugs into cancer cells. Following characterization and various modifications in the structure of CA complexes with different drugs, lifted outcomes were achieved. Markedly, complexing paclitaxel with CA resulted in 20.71 ± 4.34% loading efficiency together with 24.14 ± 2.21% enhancement in cytotoxicity on MCF-7 cells plus superior in vivo anti-tumour efficacy compared to free paclitaxel

Nanoparticles-facilitated intracellular transport of siRNAs against individual integrin subunits inhibits growth of breast cancer cells

For cells and tissues, cell–cell and cell–extracellular matrix adhesion is important for proliferation, differentiation, and response to mechanical stimuli. This adhesion is provided by various cell adhesion molecules (CAMs). However, in breast cancer, depending upon the type and stage, this adherence is dysregulated where the expression of these cell adhesion molecules is either overregulated or unregulated, triggering essential oncogenic pathways. Thus, to control the invasiveness of tumor cells, and reduce metastasis, regulating the homophilic and heterophilic interaction of these molecules and controlling the essential cell pathways is important. In this study, we targeted critical CAMs- integrins to regulate their aberrated behavior via siRNAs delivery. However, as due to charge repulsion and propensity to be degraded by nucleases prior to reaching the target site, naked siRNAs are unable to cross plasma membrane, use of a suitable carrier vehicle is essential. Thus, we employed carbonate apatite (CA), to deliver the selected siRNAs targeting integrin αv, α6, β1, β3, β4, β5, and β6 subunits to various breast cancer cell lines and 4T1-breast cancer induced murine model. Delivery of individual integrin siRNAs complexed with CA nanoparticles (NPs) reduced cell viability and caused decrease in tumor burden. To check the gene knockdown effects on phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and extracellular signal–regulated kinases/mitogen-activated protein kinase (ERK/MAPK) pathways, Western blot analysis was performed, revealing downregulation of the signaling molecules. Thus, CA-facilitated gene therapy targeting various integrins could poise potential therapeutic modality against breast cancer

Purification of transcriptionally active multimeric plasmid DNA using zwitterionic detergent and carbonate apatite nano-particles.

Plasmid DNA is one of the indispensable components in molecular biology research and a potential biomaterial for gene therapy and DNA vaccination. Both quality and quantity of extracted plasmid DNA are of the great interests in cloning and subsequent expression of genes in vitro and in vivo for basic research and therapeutic interventions. Bacteria with extremely short generation times are the valuable source of plasmid DNA that can be isolated through a number of existing techniques. However, the current methods have some limitations in isolating high quality plasmid DNA since the multimeric plasmid which is believed to be more efficiently transcribed by RNA polymerase than the monomeric form, is almost lost during the extraction process. Recently, we developed a rapid isolation technique for multimeric plasmid based on generation of a ‘protein aggregate’ using a zwitterionic detergent and alkali. Here we have investigated the roles of different parameters in the whole extraction process to optimise the production of high quality multimeric plasmid DNA. Moreover, we have showed the advantageous effects of nanoparticles to effectively sediment the ‘protein aggregate’ for smooth elution of multimeric plasmid DNA from it. Finally, quality assessment study has revealed that the isolated multimeric DNA is at least 10 times more transcriptionally active than the monomeric form isolated by the commercially available Qiaget kit