Pedro D. Zapata

Copper inducing effect on laccase production of white rot fungi native from Misiones (Argentina)

Fungi may be selected as models for gene expression studies and further adaptation for biotechnological enzyme production. The aim of this work was to evaluate laccase production and to analyze the effect of Cu(2+) on selected fungi natives of Misiones, Ganoderma applanatum (strain F), Peniophora sp. (BAFC 633), Pycnoporus sanguineus (BAFC 2126) and Coriolus versicolor f. antarcticus (BAFC 266). Fungi secretion system of G. applanatum, Peniophora sp., P. sanguineus and C. versicolor f. antarcticus is sensitive to stimulation by copper. Biomass values of G. applanatum, Peniophora sp. and C. versicolor f. antarcticus did not show differences between treatments. P. sanguineus biomass underwent a dramatic growth inhibition with 1mM Cu(2+) and marked delay in growth with 0.5mM Cu(2+). Proteins were increased with copper in Peniophora sp., C. versicolor and G. applanatum. G. applanatum and Peniophora sp. reached the highest enzyme activity at 10th day equivalent to 49.2-fold and 19.7-fold higher than the control samples, respectively. Copper produced an increase of constitutive laccases in all fungi and an additional inducible isoenzyme in Peniophora sp., C. versicolor f. antarcticus and G. applanatum.

Tumoral prostate shows different expression pattern of somatostatin receptor 2 (SSTR2) and phosphotyrosine phosphatase SHP-1 (PTPN6) according to tumor progression.

Prostate proliferation is dependent of androgens and many peptide hormones. Recent reports suggest that SSTR2 and SHP-1 were two fundamental components on antiproliferative effect of somatostatin. Many studies on SHP-1 revealed that the expression of this protein was diminished or abolished in several of the cancer cell lines and tissues examined. However, it is necessary to confront the cell lines data with real situation in cancer cases. Our studies have shown that epithelial expressions of both proteins, SHP-1 and SSTR2, in normal and benign hyperplasia are localized in the luminal side of duct and acinar cells. Also, SSTR2 is expressed in stromal cells. In malignant prostate tissue, SHP-1 was diminished in 28/45 cases or absent in 12/45 cases, whereas SSTR2 epithelial was diminished in 38/45 cases or lost in only 2/45 cases. The intensity of immunostained was highly negative correlated with Gleason grade for two proteins.

White Rot Fungi Laccases for Biotechnological Applications

White rot fungi have an enzymatic system producing oxidative and hydrolytic enzymes that act on the degradation of certain components of the cell wall. They can be applied in several technological processes, such as paper industry, bio-fuels and environmental pollution. Laccases are multi-copper enzymes of wide substrate specificity and high non-specific oxidation capacity that use molecular oxygen to oxidize various aromatic compounds, and are highly relevant biotechnological applications. In this review, we present some significant patents on laccase production and recombinant DNA technology for diverse biotechnology applications.

Phosphotyrosine Phosphatases in Cancer Diagnostic and Treatment

The activation of proteins by post-translational modification represents an important cellular mechanism for regulating most aspects of biological organization and control, including growth, development, homeostasis, and cellular communication. The complexity of protein modification includes phosphorylation and dephosphorylation, on proteins of different signaling pathways corresponding to growth, development, disease states, and aging. Current patents in phosphotyrosine phosphatases signaling pathway are focusing in diagnosis, prognosis and treatment. Many, new diagnosis techniques detect changes in mRNA expression with microarray technologies and others introduced specific antibodies for detection proteins changes, introducing to Biomedicine at Transcriptomic and Proteomic era. Many recent invent development alternative therapy with antibodies and inhibitors to PTPs that demonstrate the need to deepen understanding of the molecular mechanisms involved in the development of cancer.

Recent Patents Related to Phosphorylation Signaling Pathway on Cancer

Phosphorylation and dephosphorylation play an important role in the regulation of growth factor and cytokine signal transduction to modulate cell proliferation, differentiation, survival, and apoptosis. In some cellular systems, the information suggests that EGFR, somatostatin receptors, SHP-1, Akt and PI3K can regulate carcinogenesis implied process through regulated the activity of NF-κB. Current patents related to signaling pathway that includes somatostatin receptors, phosphotyrosine phosphatases, tyrosine kinases, AKT/PKB and PI3K are focusing in diagnosis, prognosis and treatment. Many recent patented techniques include inhibition, antagonism or alternative therapeutic methods. Furthermore, it is necessary to deepen understanding of the molecular mechanisms involved in cancer to develop other alternative therapies focusing not only on new inhibitors.

Preliminary studies of new strains of Trametes sp. from Argentina for laccase production ability

Oxidative enzymes secreted by white rot fungi can be applied in several technological processes within the paper industry, biofuel production and bioremediation. The discovery of native strains from the biodiverse Misiones (Argentina) forest can provide useful enzymes for biotechnological purposes. In this work, we evaluated the laccase and manganese peroxidase secretion abilities of four newly discovered strains of Trametes sp. that are native to Misiones. In addition, the copper response and optimal pH and temperature for laccase activity in culture supernatants were determined. The selected strains produced variable amounts of laccase and MnP; when Cu2+ was added, both enzymes were significantly increased. Zymograms showed that two isoenzymes were increased in all strains in the presence of Cu2+. Strain B showed the greatest response to Cu2+ addition, whereas strain A was more stable at the optimal temperature and pH. Strain A showed interesting potential for future biotechnological approaches due to the superior thermo-stability of its secreted enzymes.

α6β4 Integrin Genetic Variations (A380T and R1281W) and Breast Cancer Risk in an Argentinian Population

The α6β4 integrin is composed of the α6 and β4 subunits that are encoded by the ITGα6 and the ITGβ4 genes, respectively. The α6β4 main function is to intervene in lamination and epithelia integrity maintenance by cell-matrix interactions. This integrin appears to have importance in breast cancer malignancy, as well as other epithelial carcinomas. The aim of this work was to investigate the potential role of ITGα6 (A380T) and ITGβ4 (R1281W) genetic variations in breast cancer susceptibility, in a female population from the northeast region of Argentina (Misiones). We performed a case-control study of 85 breast cancer patients and 113 cancer-free controls. Genotyping was performed by RFLP-PCR. For ITGα6 (A380T) single nucleotide polymorphism, a high frequency of heterozygous genotype GA in cases compared to controls was observed, achieving values of 48% and 49%, respectively. No association between the A380T SNP and breast cancer development was found (Odds Ratio = 0.92; 95% Confidence Interval = 0.52–1.63; p = 0.884). In conclusion, we did not find evidence of an association between A380T (ITGα6) and the risk of developing breast cancer. The results represent the first report of these genetic variations in breast cancer; therefore, they are an important contribution to the literature.