Early developmental expression of a normally tumor-associated and drug-inhibited cell surface-located NADH oxidase (ENOX2) in non-cancer cells

Ecto-NOX Disulfide-Thiol Exchanger 2 (ENOX2/tNOX) Is a Potential Prognostic Marker in Primary Malignant Melanoma and May Serve as a Therapeutic Target

With an increasing incidence of malignant melanoma, new prognostic biomarkers for clinical decision making have become more important. In this study, we evaluated the role of ecto-NOX disulfide-thiol exchanger 2 (ENOX2/tNOX), a cancer- and growth-associated protein, in the prognosis and therapy of primary malignant melanoma. We conducted a tissue microarray analysis of immunohistochemical ENOX2 protein expression and The Cancer Genome Atlas (TCGA) ENOX2 RNA expression analysis, as well as viability assays and Western blots of melanoma cell lines treated with the ENOX2 inhibitor phenoxodiol (PXD) and BRAF inhibitor (BRAFi) vemurafenib. We discovered that high ENOX2 expression is associated with decreased overall (OS), disease-specific (DSS) and metastasis-free survival (MFS) in primary melanoma (PM) and a reduction in electronic tumor-infiltrating lymphocytes (eTILs). A gradual rise in ENOX2 expression was found with an increase in malignant potential from benign nevi (BNs) via PMs to melanoma metastases (MMs), as well as with an increasing tumor thickness and stage. These results highlight the important role of ENOX2 in cancer growth, progression and metastasis. The ENOX2 expression was not limited to malignant cell lines but could also be found in keratinocytes, fibroblasts and melanocytes. The viability of melanoma cell lines could be inhibited by PXD. A reduced induction of phospho-AKT under PXD could prevent the development of acquired BRAFi resistance. In conclusion, ENOX2 may serve as a potential prognostic marker and therapeutic target in malignant melanoma.

Capsaicinoids and Their Effects on Cancer: The "Double-Edged Sword" Postulate from the Molecular Scale

Capsaicinoids are a unique chemical species resulting from a particular biosynthesis pathway of hot chilies (Capsicum spp.) that gives rise to 22 analogous compounds, all of which are TRPV1 agonists and, therefore, responsible for the pungency of Capsicum fruits. In addition to their human consumption, numerous ethnopharmacological uses of chili have emerged throughout history. Today, more than 25 years of basic research accredit a multifaceted bioactivity mainly to capsaicin, highlighting its antitumor properties mediated by cytotoxicity and immunological adjuvancy against at least 74 varieties of cancer, while non-cancer cells tend to have greater tolerance. However, despite the progress regarding the understanding of its mechanisms of action, the benefit and safety of capsaicinoids' pharmacological use remain subjects of discussion, since CAP also promotes epithelial-mesenchymal transition, in an ambivalence that has been referred to as "the double-edge sword". Here, we update the comparative discussion of relevant reports about capsaicinoids' bioactivity in a plethora of experimental models of cancer in terms of selectivity, efficacy, and safety. Through an integration of the underlying mechanisms, as well as inherent aspects of cancer biology, we propose mechanistic models regarding the dichotomy of their effects. Finally, we discuss a selection of in vivo evidence concerning capsaicinoids' immunomodulatory properties against cancer.

ENOX2 NADH Oxidase: A BCR-ABL1-Dependent Cell Surface and Secreted Redox Protein in Chronic Myeloid Leukemia

Objective

Chronic myeloid leukemia (CML) is a disease caused by the acquisition of BCR-ABL1 fusion in hematopoietic stem cells. In this study, we focus on the oncofetal ENOX2 protein as a potential secretable biomarker in CML.

Materials and Methods

We used cell culture, western blot, quantitative RT-PCR, ELISA, transcriptome analyses, and bioinformatics techniques to investigate ENOX2 mRNA and protein expression.

Results

Western blot analyses of UT-7 and TET-inducible Ba/F3 cell lines demonstrated the upregulation of the ENOX2 protein. BCR-ABL1 was found to induce ENOX2 overexpression in a kinase-dependent manner. We confirmed increased ENOX2 mRNA expression in a cohort of CML patients at diagnosis. In a series of CML patients, ELISA assays showed a highly significant increase of ENOX2 protein levels in the plasma of patients with CML compared to controls. Reanalyzing the transcriptomic dataset confirmed ENOX2 mRNA overexpression in the chronic phase of the disease. Bioinformatic analyses identified several genes whose mRNA expressions were positively correlated with ENOX2 in the context of BCR-ABL1. Some of them encode proteins involved in cellular functions compatible with the growth deregulation observed in CML.

Conclusion

Our results highlight the upregulation of a secreted redox protein in a BCR-ABL1-dependent manner in CML. The data presented here suggest that ENOX2, through its transcriptional mechanism, plays a significant role in BCR-ABL1 leukemogenesis.

The role of isoflavones in augmenting the effects of radiotherapy

Cancer is one of the major health problems and the second cause of death worldwide behind heart disease. The traditional soy diet containing isoflavones, consumed by the Asian population in China and Japan has been identified as a protective factor from hormone-related cancers. Over the years the research focus has shifted from emphasizing the preventive effect of isoflavones from cancer initiation and promotion to their efficacy against established tumors along with chemo- and radiopotentiating effects. Studies performed in mouse models and results of clinical trials emphasize that genistein or a mixture of isoflavones, containing in traditional soy diet, could be utilized to both potentiate the response of cancer cells to radiotherapy and reduce radiation-induced toxicity in normal tissues. Currently ongoing clinical research explores a potential of another significant isoflavone, idronoxil, also known as phenoxodiol, as radiation enhancing agent. In the light of the recent clinical findings, this article reviews the accumulated evidence which support the clinically desirable interactions of soy isoflavones with radiation therapy resulting in improved tumor treatment. This review discusses important aspects of the development of isoflavones as anticancer agents, and mechanisms potentially relevant to their activity in combination with radiation therapy of cancer. It gives a critical overview of studies characterizing isoflavone targets such as topoisomerases, ENOX2/PMET, tyrosine kinases and ER receptor signaling, and cellular effects on the cell cycle, DNA damage, cell death, and immune responses.

X-linked congenital ptosis and associated intellectual disability, short stature, microcephaly, cleft palate, digital and genital abnormalities define novel Xq25q26 duplication syndrome

Submicroscopic duplications along the long arm of the X-chromosome with known phenotypic consequences are relatively rare events. The clinical features resulting from such duplications are various, though they often include intellectual disability, microcephaly, short stature, hypotonia, hypogonadism and feeding difficulties. Female carriers are often phenotypically normal or show a similar but milder phenotype, as in most cases the X-chromosome harbouring the duplication is subject to inactivation. Xq28, which includes MECP2 is the major locus for submicroscopic X-chromosome duplications, whereas duplications in Xq25 and Xq26 have been reported in only a few cases. Using genome-wide array platforms we identified overlapping interstitial Xq25q26 duplications ranging from 0.2 to 4.76 Mb in eight unrelated families with in total five affected males and seven affected females. All affected males shared a common phenotype with intrauterine- and postnatal growth retardation and feeding difficulties in childhood. Three had microcephaly and two out of five suffered from epilepsy. In addition, three males had a distinct facial appearance with congenital bilateral ptosis and large protruding ears and two of them showed a cleft palate. The affected females had various clinical symptoms similar to that of the males with congenital bilateral ptosis in three families as most remarkable feature. Comparison of the gene content of the individual duplications with the respective phenotypes suggested three critical regions with candidate genes (AIFM1, RAB33A, GPC3 and IGSF1) for the common phenotypes, including candidate loci for congenital bilateral ptosis, small head circumference, short stature, genital and digital defects.

Mitochondria and reactive oxygen species. Which role in physiology and pathology?

Oxidative stress is among the major causes of toxicity due to interaction of Reactive Oxygen Species (ROS) with cellular macromolecules and structures and interference with signal transduction pathways. The mitochondrial respiratory chain, specially from Complexes I and III, is considered the main origin of ROS particularly under conditions of high membrane potential, but several other sources may be important for ROS generation, such as mitochondrial p66(Shc), monoamine oxidase, α-ketoglutarate dehydogenase, besides redox cycling of redox-active molecules. ROS are able to oxidatively modify lipids, proteins, carbohydrates and nucleic acids in mitochondria and to activate/inactivate signalling pathways by oxidative modification of redox-active factors. Cells are endowed with several defence mechanisms including repair or removal of damaged molecules, and antioxidant systems, either enzymatic or non-enzymatic. Oxidative stress is at the basis of ageing and many pathological disorders, such as ischemic diseases, neurodegenerative diseases, diabetes, and cancer, although the underlying mechanisms are not always completely understood.

hnRNP F directs formation of an exon 4 minus variant of tumor-associated NADH oxidase (ENOX2)

HUVEC or mouse 3T3 cells infected with SV-40 generate within 3 to 5 days post-infection an ENOX2 species corresponding to the exon-4 minus splice variant of a tumor-associated NADH oxidase (ENOX2 or tNOX) expressed at the cancer cell surface. This study was to seek evidence for splicing factors that might direct formation of the exon 4 minus ENOX2 splice variant. To determine if silencing of ENOX2 exon 4 occurs because of motifs located in exon 4, transfections were performed on MCF-10A (mammary non-cancer), BT-20 (mammary cancer), and HeLa (cervical cancer) cells using a GFP minigene construct containing either a constitutively spliced exon (albumin exon 2) or the alternatively spliced ENOX2 exon 4 between the two GFP halves. Removal of exon 4 from the processed RNA of the GFP minigene construct occurred with HeLa and to a lesser extent with BT-20 but not in non-cancer MCF-10A cells. The Splicing Rainbow Program was used to identify all of the possible hnRNPs binding sites of exon 4 of ENOX2. There are 8 Exonic Splicing Silencers (ESSs) for hnRNP binding in the exon 4 sequences. Each of these sites were mutated by site-directed mutagenesis to test if any were responsible for the splicing skip. Results showed MutG75 ESS mutation changed the GFP expression which is a sign of splicing silence, while other mutations did not. As MutG75 changed the ESS binding site for hnRNP F, this result suggests that hnRNP F directs formation of the exon 4 minus variant of ENOX2.

Flavonoids, phenoxodiol, and a novel agent, triphendiol, for the treatment of pancreaticobiliary cancers

Flavonoids, in particular the isoflavones, are naturally occurring compounds found in soy and textured vegetables that have antiproliferative effects on a variety of cancer types. Phenoxodiol is a derivative of the isoflavone genisten that is 5-20 times more potent than genisten. Triphendiol is a derivative of phenoxodiol that has superior anticancer activity against pancreatic and bile duct cancers. This review will focus on the mechanisms of action and activity of two isoflavone derivatives, phenoxodiol and triphendiol, in various tumor types, especially pancreaticobiliary cancers. Triphendiol induces apoptosis in pancreatic cell lines by both caspase-mediated and caspase-independent mechanisms. The addition of triphendiol to gemcitabine is synergistic in in vitro and in vivo models of pancreatic cancer and represents a novel combination of drugs for pancreatic cancer patients.