Silencing of ZRF1 impedes survival of estrogen receptor positive MCF-7 cells and potentiates the effect of curcumin

Metallo-protease Peptidase M84 from Bacillusaltitudinis induces ROS-dependent apoptosis in ovarian cancer cells by targeting PAR-1

We have purified Peptidase M84 from Bacillus altitudinis in an effort to isolate anticancer proteases from environmental microbial isolates. This metallo-protease had no discernible impact on normal cell survival, but it specifically induced apoptosis in ovarian cancer cells. PAR-1, a GPCR which is reported to be overexpressed in ovarian cancer cells, was identified as a target of Peptidase M84. We observed that Peptidase M84 induced PAR-1 overexpression along with activating its downstream signaling effectors NF-κB and MAPK to promote excessive reactive oxygen species (ROS) generation. This evoked apoptotic death of the ovarian cancer cells through the intrinsic route. In in vivo set-up, weekly intraperitoneal administration of Peptidase M84 in syngeneic mice significantly diminished ascites accumulation, increasing murine survival rates by 60%. Collectively, our findings suggested that Peptidase M84 triggered PAR-1-mediated oxidative stress to act as an apoptosis inducer. This established Peptidase M84 as a drug candidate for receptor mediated targeted-therapy of ovarian cancer.

Neuronal Differentiation-Related Epigenetic Regulator ZRF1 Has Independent Prognostic Value in Neuroblastoma but Is Functionally Dispensable In Vitro

Simple Summary

Neuroblastoma is the most common pediatric solid tumor occurring outside the brain, and it is thought to arise from cells that acquire errors during the normal process of embryonal development. Today, we know that embryonal development is regulated by epigenetics, a mechanism that determines which genes need to be expressed in each cell type and developmental step. Epigenetic errors, therefore, are considered contributory to the appearance and progression of tumors such as neuroblastoma. Here, we aimed at finding whether ZRF1, a known epigenetic regulator, could play a significant role in the aggressiveness of neuroblastoma. Our results suggest that ZRF1 does not seem to have any relevant function in neuroblastoma cells; however, the levels of this epigenetic regulator are related to the prognostic of neuroblastoma patients and could be used to predict their progression and improve the diagnosis.

Abstract

Neuroblastoma is a pediatric tumor of the peripheral nervous system that accounts for up to ~15% of all cancer-related deaths in children. Recently, it has become evident that epigenetic deregulation is a relevant event in pediatric tumors such as high-risk neuroblastomas, and a determinant for processes, such as cell differentiation blockade and sustained proliferation, which promote tumor progression and resistance to current therapies. Thus, a better understanding of epigenetic factors implicated in the aggressive behavior of neuroblastoma cells is crucial for the development of better treatments. In this study, we characterized the role of ZRF1, an epigenetic activator recruited to genes involved in the maintenance of the identity of neural progenitors. We combined analysis of patient sample expression datasets with loss- and gain-of-function studies on neuroblastoma cell lines. Functional analyses revealed that ZRF1 is functionally dispensable for those cellular functions related to cell differentiation, proliferation, migration, and invasion, and does not affect the cellular response to chemotherapeutic agents. However, we found that high levels of ZRF1 mRNA expression are associated to shorter overall survival of neuroblastoma patients, even when those patients with the most common molecular alterations used as prognostic factors are removed from the analyses, thereby suggesting that ZRF1 expression could be used as an independent prognostic factor in neuroblastoma.

Bioengineered ethosomes encapsulating AgNPs and Tasar silk sericin proteins for non melanoma skin carcinoma (NMSC) as an alternative therapeutics

Rising cases of Non melanoma skin carcinoma (NMSC) and escalating levels of ultraviolet radiations have underlined a profound correlation with the elevating levels of environmental detoriation and increasing health issues. However, the availability of therapeutics has not aided in controlling the recurrence rates of skin carcinoma. Frequent administration of therapeutics with higher chances of facial deformity escalates the patient's treatment expenses. Thus, this study initiates a low cost effective and biodegradable therapy by exploring four formulations with combinations of silver nanoparticles (AgNPs), sericin (isolated from cocoons of Antherea mylitta) and chitosan. Subsequently, various ethosomal formulations were evaluated as a platform for transdermal delivery vehicle for efficient skin intervention therapeutics. Characterization using UV visible spectroscopy, Dynamic light scattering, Fourier Infrared spectroscopy, X-ray dispersion, Transmission electron microscopy, Fluorescence assisted cell sorting and in vitro studies were done and it was inferenced that equal combination of AgNPs and sericin facilitated to combat the morphological and cellular deformation of the epidermoid A431skin carcinoma cells. The overproduction of superoxide (O^2.) and nitric oxide (NO) radicals consequently depolarized the mitochondrial membrane potential triggering apoptosis and necrosis. The in vivo experiments exhibited the stimulation of IgM secretion with T cell-mediated immune response. Therefore, this study proposes a novel approach for treatment of NMSC using biocompatible formulations delivered through ethosomes.

Overexpression of ZRF1 is related to tumor malignant potential and a poor outcome of gastric carcinoma

Zuotin-related factor 1 (ZRF1) is a recently characterized epigenetic factor involved in transcriptional regulation and is highly overexpressed in several malignancies, but it is not known whether it plays a role in gastric cancer (GC). In this study, we investigated whether ZRF1 acts as a cancer-promoting gene through its activation/overexpression in GC. We analyzed five GC cell lines and 133 primary tumors, which had been curatively resected in our hospital between 2001 and 2003. Overexpression of ZRF1 was detected in GC cell lines (four out of five lines, 80.0%) and was detected in primary tumor samples of GC (52 out of 133 cases, 39.1%) and significantly correlated with differentiated histological type, venous invasion, lymphatic invasion, advanced stage and a higher recurrence rate. ZRF1-overexpressing tumors had a worse survival rate than those with non-expressing tumors (P < 0.01, log-rank test). ZRF1 positivity was independently associated with a worse outcome in the multivariate analysis (P < 0.01; hazard ratio 4.92; 95% confidence interval: 1.6-21.1). In ZRF1-overexpressing GC cells, knockdown of ZRF1 using specific siRNAs inhibited the cell proliferation, migration and invasion and induced apoptosis in a p53-dependent manner. These findings suggest that ZRF1 plays a crucial role in tumor malignant potential through its overexpression and highlight its usefulness as a prognostic factor and potential therapeutic target in GC.

Role for the transcriptional activator ZRF1 in early metastatic events in breast cancer progression and endocrine resistance

Breast cancer is one of the most common malignancies among women which is often treated with hormone therapy and chemotherapy. Despite the improvements in detection and treatment of breast cancer, the vast majority of breast cancer patients are diagnosed with metastatic disease either at the beginning of the disease or later during treatment. Still, the molecular mechanisms causing a therapy resistant metastatic breast cancer are still elusive. In the present study we addressed the function of the transcriptional activator ZRF1 during breast cancer progression. We provide evidence that ZRF1 plays an essential role for the early metastatic events in vitro and acts like a tumor suppressor protein during the progression of breast invasive ductal carcinoma into a more advanced stage. Hence, depletion of ZRF1 results in the acquisition of metastatic behavior by facilitating the initiation of the metastatic cascade, notably for cell adhesion, migration and invasion. Furthermore absence of ZRF1 provokes endocrine resistance via misregulation of cell death and cell survival related pathways. Taken together, we have identified ZRF1 as an important regulator of breast cancer progression that holds the potential to be explored for new treatment strategies in the future.

In vitro Biological Effects of Sulforaphane (SFN), Epigallocatechin-3-gallate (EGCG), and Curcumin on Breast Cancer Cells: A Systematic Review of the Literature

Much of the recent research in neoplasia has been focusing on the epigenetics of cancer cells, particularly as regards the search for potential molecular biomarkers that could be used for early diagnosis, effective treatment, and prognosis of several types of cancer. Carcinogenesis often starts with mutations in oncogenes and tumor suppressor genes, and it leads to anomalies in cellular processes as vital as cell cycle regulation and apoptosis. Because malignant changes arise as a result of genetic as well as epigenetic mechanisms, one possible means of intervention involves reprogramming gene expression, so as to-at least in part-revert the molecular alterations. DNA methylation and demethylation, acetylation and deacetylation of histones, and microRNAs are a few examples of the epigenetic mechanisms responsible for tumor development and progression. Many biologically active compounds present in food-including sulforaphane, curcumin, and epigallocatechin-have been found to modulate those processes. We here systematically review information on the effects of such bioactive dietary compounds on human breast cancer cell lines, and explore the mechanisms underlying those effects with a view to their potential therapeutic application.

Zinc oxide nanoparticle energy band gap reduction triggers the oxidative stress resulting into autophagy-mediated apoptotic cell death

The physico-chemical properties of nanoparticle (NP), such as particle size, surface defects, crystallinity and accessible surface, affect NP photocatalytic activity that in turn defines the NP cytotoxic propensity. Since zinc oxide nanoparticle (ZnONP) energy band gap falls in a range of a semiconductor, the particle possesses photocatalytic activity. Hence, the study correlates energy band gap with cytotoxic propensity of ZnONP. To this end, ZnONPs with varying energy band gap are fabricated by varying calcination temperature. Cytotoxic propensity of the fabricated ZnONPs against HT1080 cell indicates that the particle with least energy band gap shows highest cytotoxicity. The data also indicate that the cytotoxicity is triggered primarily through reactive oxygen species (ROS)-mediated pathway. Additionally, the comet assay and γH2AX activity assay reveal that decreasing energy band gap of the particle increases DNA damaging propensity. Furthermore, cell cycle analysis indicates that the cell treatment with decreasing energy band gap ZnONP results in significant increase in cell population fraction in subG₁ phase. Whereas, acridine orange binding assay and increased expression level of LC3II indicate that the cell tries to recover the stress by scavenging damaged cellular biomolecules and ROS using autophagosomes. Nevertheless, cell with the non-recoverable damages led into apoptotic cell death, as confirmed by Annexin V apoptosis assay, DNA fragmentation assay and 4,6-Diamidino-2-phenylindole dihydrochloride (DAPI) staining.

Two chaperones locked in an embrace: structure and function of the ribosome-associated complex RAC

Chaperones, which assist protein folding are essential components of every living cell. The yeast ribosome-associated complex (RAC) is a chaperone that is highly conserved in eukaryotic cells. The RAC consists of the J protein Zuo1 and the unconventional Hsp70 homolog Ssz1. The RAC heterodimer stimulates the ATPase activity of the ribosome-bound Hsp70 homolog Ssb, which interacts with nascent polypeptide chains to facilitate de novo protein folding. In addition, the RAC-Ssb system is required to maintain the fidelity of protein translation. Recent work reveals important details of the unique structures of RAC and Ssb and identifies how the chaperones interact with the ribosome. The new findings start to uncover how the exceptional chaperone triad cooperates in protein folding and maintenance of translational fidelity and its connection to extraribosomal functions.

Biofilm Impeding AgNPs Target Skin Carcinoma by Inducing Mitochondrial Membrane Depolarization Mediated through ROS Production

Reactive oxygen species (ROS) are a double-edged sword that possesses both beneficial and harmful effects. Although basic research on skin cancer prevention has undergone a huge transformation, cases of recurrence with higher rates of drug resistance are some of its drawbacks. Therefore, targeting mitochondria by ROS overproduction provides an alternate approach for anticancer therapy. In the present study, green-synthesized silver nanoparticles (AgNPs) were explored for triggering the ROS production in A431 skin carcinoma cells. The synthesized AgNPs were characterized for size, charge, morphology, and phase through high-throughput DLS, Fe-SEM, XRD, and ATR-FTIR techniques. Their physiochemical properties with hemoglobin and blood plasma were screened through hemolysis, hemagglutination assay, and circular dichroism spectroscopy confirmed their nontoxic nature. The AgNPs also exhibited additional efficacy in inhibiting biofilm produced by V. cholerae and B. subtilis, thereby facilitating better applicability in wound-healing biomaterials. The depolarization of mitochondrial membrane potential ΔΨm through excess ROS production was deduced to be the triggering force behind the apoptotic cell death mechanism of the skin carcinoma. Subsequent experimentation through DNA fragmentation, comet tail formation, cell membrane blebbing, and reduced invasiveness potentials through scratch assay confirmed the physiological hallmarks of apoptosis. Thus, depolarizing mitochondrial membrane potential through green-synthesized AgNPs provides an economic, nontoxic, specific approach for targeting skin carcinoma with additional benefits of antibacterial activities.