High therapeutic efficacy of 5-Fluorouracil-loaded exosomes against colon cancer cells.

The successful chemotherapeutic regime required for the clinical management of different cancers largely depends on the efficient drug delivery within the cancer cells. Exosomes have emerged as an enticing candidate for exploring their role as delivery vehicles. Exosomes are reported to be intrinsically nanosized vesicles competent for efficient delivery across the cellular membrane. In the present study, we assessed the feasibility of an autologous exosome-based drug delivery platform for delivering 5-Fluorouracil (5-FU) against human colon cancer HCT116 cells. Autologous exosomes have shown probable tropism toward the tumor microenvironment, which makes them the most competitive vehicle for drug delivery. It was observed that the autologous exosomes loaded with 5-FU showed an enhanced rate of drug release under acidic conditions. The result of the cell viability assay showed that treatment of 5-FU-loaded exosomes (equivalent to 5 µg 5-FU) resulted in enhanced cytotoxic effect in HCT116 cells as compared to an equivalent amount of free 5-FU (5 µg), which elucidated the efficient delivery of the 5-FU by exosomes inside the cancer cells. Subsequently, 5-FU-loaded exosomes led to increased nuclear condensation and fragmentation along with increased ROS production. In addition, 5-FU-loaded exosomes caused enhanced dissipation of mitochondrial membrane potential and caspase-3 activation, resulting in increased apoptosis induction. Our study also revealed that 5-FU-loaded exosomes upsurged the arrest in the cell cycle at the G0/G1 stage in HCT-116 cells and it was found to be associated with decreased CDK4 and Cyclin D1 expression concomitantly with the upregulation of CDK inhibitor, p21Cip1 expression. Thus, the findings from the present study highlight the advantages of autologous exosomes as a natural drug carrier which could efficiently deliver chemotherapeutic drugs to cancer cells.

Ethanolic extract of Coleus aromaticus leaves impedes the proliferation and instigates apoptotic cell death in liver cancer HepG2 cells through repressing JAK/STAT cascade.

Liver cancer or hepatocellular carcinoma (HCC) has become a leading cause for cancer burden across the globe, and incidences have tripled since the last two decades. Poor diagnosis of primary liver cancer and limited treatment strategies aggravate the challenges. Researchers globally have shown a steep inclination toward the exploration of plant-based compounds for their nutraceutical and anticancer potential to fit into the role of novel chemotherapeutics. Coleus aromaticus is a well-known culinary herb that earlier has been reported for several medicinal attributes. The current investigation deals with exploring the anticancer potential of ethanolic leaf extract of C. aromaticus (CoL-EtOH) against hepatocellular carcinoma HepG2 cell line. The observations made it evident that CoL-EtOH extract impeded the viability of HepG2 at 400 µg/ml (p < .01). Additionally, the extract also succeeded in escalating ROS production (p < .01) which aided dissipation of mitochondrial membrane potential and disruption of nuclear morphology. CoL-EtOH further activated caspase-8, -9, and -3 which was reaffirmed by increase in apoptosis at 400 µg/ml (p < .01). Moreover, post treatment with CaLEt-OH extract significantly reduced the expression of JAK-1 & STAT-3 genes (p < .01) along with regulated expression of Mcl1, Bcl-2, cyclinD1, p21, and p27 within HepG2 cells. This evidence portrays the promising anticancer potential of CoL-EtOH projecting it as a novel chemotherapeutic agent against HCC. PRACTICAL APPLICATIONS: The herb Coleus aromaticus belonging to Lamiaceae family and Coleus genus is known by various names in different regions of the world and several language-specific vernacular names. The herb has been used in therapeutic and medicinal applications as well as in culinary preparations. Various attributes of the nutritional strength and functional characteristics of the leaves in terms of carotenoids, minerals, phenols, dietary fiber, and antioxidant activity have been reported by several researchers. Carvacrol and thymol are majorly found in the plant, while chlorogenic acid and rosmarinic acid etc. as the phenolic components. The herb has been used in therapeutic and medicinal implications as well as in culinary preparations.

Repolarization of glioblastoma macrophage cells using non-agonistic Dectin-1 ligand encapsulating TLR-9 agonist: plausible role in regenerative medicine against brain tumor.

AIM OF THE STUDY: Glioblastoma multiforme (GBM) is the most severe forms of brain cancer, eventually becoming the leading cause of brain cancer-related death worldwide. Owing to the bleak surgical interventions and resistance to the different treatment regime, GBM is a parlous disease demanding newer therapeutical perspective for its treatment. Toll-like receptors (TLRs) are well-known members of pathogen recognition receptors (PRRs) and have been extensively explored for their therapeutic and prophylactic potential in an array of disease including cancer. Recent trends in drug delivery research has shown shift towards delivering short DNA sequences (CpG DNA) to endosomal TLR9 within immune cells (macrophages, dendritic cells, etc.) for the activation of desired inflammatory response using non-agonistic ß-glucan particles; a well-known ligand for Dectin-1 receptors. Our study is therefore focused to explore the role of nano-encapsulated CpG ODN as critical players in polarizing M2 scavenging to much desired pro-inflammatory type. MATERIALS AND METHODS: The nanoparticles entrapping CpG ODN 1826 were prepared by using a fungal polymer Schizophyllan (SPG). The constructed nanoparticles were characterized and assessed for their efficacy on rat glioblastoma cells (C6). RESULTS: The constructed Schizophyllan (SPG) nanoparticles entrapping CpG ODN 1826 (95.3%) were of 25.49 nm in diameter and thus capable of crossing blood-brain barrier. The rat glioblastoma (C6) cells evaluated for intracellular oxidative burst and cytokine levels pre- and post-incubation with nanoparticles exhibited marked elevation in the expression of intracellular ROS and IFN-γ as well as IL-1ß post treatment. CONCLUSION: The findings indicate towards potentiality of repolarizing the M2 macrophages to much desired M1 phase by inducing higgh levels of oxidative burst and inflammatory cytokines. Consequently, the apoptosis was induced in glioblastoma cells establishing the suitablity of CpG ODN carrying nanoformulations as emerging therapeutic intervention for GBM.

Leishmanial CpG DNA nanovesicles: A propitious prophylactic approach against visceral leishmaniasis.

Unmethylated CpG motifs with phosphothioate backbone trigger TLR9 to elicit innate immune response characterized by the production of Th1 cytokines. The use of CpG DNA as an adjuvant has established its role in potentiating the humoral and cell mediated vaccine specific immune response. However, none of the synthetic oligodeoxynucleotides (ODNs) know and used till date are associated with the parasite itself. Our group identified a novel CG rich sequence of 14 base pairs from Leishmania donovani genome (Ld CpG ODN) and established it as a TLR9 agonist. The present study was designed to ascertain the adjuvanticity of Ld CpG ODN with soluble leishmanial antigen in experimental model of L. donovani. During the study Schizophyllan (SPG), a fungal polymer was used for encapsulating Ld CpG ODN for efficient endosomal delivery. The synthesized nanovehicles were of nearly 100 nm and localized within endosomes as confirmed by confocal microscopy. Immunization studies displayed the superior ability of synthesized nanovehicles co-administered with parasite antigen in augmenting innate immune response in comparison to ODN, nanoparticles or soluble antigen alone. The response included generation of ROS, NO and iNOS expression followed by proinflammatory cytokine milieu with reduced parasitic load within liver, spleen and bone marrow. These immune-tailored particles in combination with parasitic antigens elicited significant generation of cell mediated response owing to the presence of high levels of CD8+ T-cells and lymphocyte proliferation. Moreover, vaccination regime with synthesized adjuvant also activated humoral immunity by escalating the levels of IgG2 followed by reduced levels of anti-leishmanial IgG and IgG1 antibodies. The findings support the efficacy of Ld CpG ODN as a potential adjuvant against visceral leishmaniasis.

Jab1-siRNA Induces Cell Growth Inhibition and Cell Cycle Arrest in Gall Bladder Cancer Cells via Targeting Jab1 Signalosome.

BACKGROUND: The aberrant alteration in Jab1 signalosome (COP9 Signalosome Complex Subunit 5) has been proven to be associated with the progression of several carcinomas. However the specific role and mechanism of action of Jab1 signalosome in carcinogenesis of gall bladder cancer (GBC) are poorly understood. OBJECTIVE: The main objective of our study was to elucidate the role and mechanism of Jab1 signalosome in gall bladder cancer by employing siRNA. METHODS: Jab1 overexpression was identified in gall bladder cancer tissue sample. The role of Jab1-siRNA approach in cell growth inhibition and apoptotic induction was then examined by RT-PCR, Western Blotting, MTT, ROS, Hoechst and FITC/Annexin-V staining. RESULTS: In the current study, we have shown that overexpression of Jab1 stimulated the proliferation of GBC cells; whereas downregulation of Jab1 by using Jab1-siRNA approach resulted incell growth inhibition and apoptotic induction. Furthermore, we found that downregulation of Jab1 induces cell cycle arrest at G1 phase and upregulated the expression of p27, p53 and Bax gene. Moreover, Jab1-siRNA induces apoptosis by enhancing ROS generation and caspase-3 activation. In addition, combined treatment with Jab1-siRNA and gemicitabine demonstrated an enhanced decline in cell proliferation which further suggested increased efficacy of gemcitabine at a very lower dose (5µM) in combination with Jab1-siRNA. CONCLUSION: In conclusion, our study strongly suggests that targeting Jab1 signalosome could be a promising therapeutic target for the treatment of gall bladder cancer.

Elucidation of the Chemopreventive Role of Stigmasterol Against Jab1 in Gall Bladder Carcinoma.

BACKGROUND: Plant sterols have proven a potent anti-proliferative and apoptosis inducing agent against several carcinomas including breast and prostate cancers. Jab1 has been reported to be involved in the progression of numerous carcinomas. However, antiproliferative effects of sterols against Jab1 in gall bladder cancer have not been explored yet. OBJECTIVE: In the current study, we elucidated the mechanism of action of stigmasterol regarding apoptosis induction mediated via downregulation of Jab1 protein in human gall bladder cancer cells. METHODS: In our study, we performed MTT and Trypan blue assay to assess the effect of stigmasterol on cell proliferation. In addition, RT-PCR and western blotting were performed to identify the effect of stigmasterol on Jab1 and p27 expression in human gall bladder cancer cells. We further performed cell cycle, Caspase-3, Hoechst and FITC-Annexin V analysis, to confirm the apoptosis induction in stigmasterol treated human gall bladder cancer cells. RESULTS: Our results clearly indicated that stigmasterol has up-regulated the p27 expression and down-regulated Jab1 gene. These modulations of genes might occur via mitochondrial apoptosis signaling pathway. Caspase-3 gets activated with the apoptotic induction. Increase in apoptotic cells and DNA were confirmed through annexin V staining, Hoechst staining, and cell cycle analysis. CONCLUSION: Thus, these results strongly suggest that stigmasterol has the potential to be considered as an anticancerous therapeutic agent against Jab1 in gall bladder cancer.