Recent Patents on DNA & Gene Sequences (Discontinued) - Volume 4, Issue 1, 2010

Type 2 diabetes mellitus has become a world wide extended disease, and while insulin insensitivity is an early phenomenon partly related to obesity, pancreas β-cell function declines gradually over time already before the onset of clinical hyperglycaemia. Therefore, drugs able to stimulate or enhance insulin secretion will moderate hyperglycemia and then reduce the occurrence of later complication of the disease. Current strategies in type 2 diabetes include sulphonylurea compounds, GLP1, exendin 4 and DPP4 inhibitors and GK activators. Since many diabetic patients still exhibit poor glycemic control, other fail to respond to the treatment, and some develop serious complications, more effective treatments for diabetes than those mentioned above remain challenging for modern research. Then, the present review will focus on existing approaches and novel patents targeting β-cell, with special emphasis in those related with the glucoseinduced insulin secretion process. The management of this disease includes not only diet and exercise, but also utilization of antihyperglycemic new drugs, gene therapy strategies and combinations of novel insulin releasers and secretagogues.

Research on antimicrobial peptides has gained pace to exploit their potential and ability to replace conventional antibiotics. Antimicrobial peptides are important members of the host defense system, as they have a broad ability to kill microbes. Antimicrobial peptides and proteins form an important means of host defense in eukaryotes. Large antimicrobial proteins (> 100 a.a.), are often lytic, nutrient-binding proteins or specifically target the microbial macromolecules. Small antimicrobial peptides act by disrupting the structure or function of microbial cell membranes. A multitude of antimicrobial peptides has been found in the epithelial layers, phagocytes, and body fluids of multicellular animals including humans. Aside from their role as endogenous antibiotics, antimicrobial peptides have functions in inflammation, wound repair, and regulation of the adaptive immune system. In this review, we discuss recent patents relating to antimicrobial peptides. These patents are related to the method of identifying peptides that have antimicrobial activity, including the papillosin antimicrobial peptide and its encoding gene, the antimicrobial peptide isolated from Halocynthia aurantium, retrocyclins, and the use of cathelicidin LL-37 and its derivatives for wound healing. These patents provide valuable information that could be useful in the identification of antimicrobial peptides and the exploitation of their therapeutic potential.

The importance of RNA in vital cellular events like gene expression, transport, self-splicing catalytic activity etc., renders them an alternative target for drugs and other specific RNA binding ligands. RNA targets gain significance for the fact that targeting DNA with therapeutics sooner leads to drug resistance and severe side effects by impairing essential function of the genes. However the unique structural features of the RNA facilitate targeting in two different approaches: 1) targeting the catalytic activity of the RNA (ribozyme) 2) exploiting the catalytic functions of ribozyme to target other cellular RNA of our interest. The first strategy leads to the inhibition of ribozyme catalysis by small molecule drugs or RNA binders. This would be very much effective in terms of unique target for specific RNA binders as ribozymes are present in certain pathogens and nonexistent in humans. Apart from targeting ribozymes by therapeutics the second strategy explores that ribozymes by itself can act as therapeutics to correct the defective cellular RNA by transsplicing activity and are renowned as equivalent as that of any gene therapy for genetic disorders or it can be a “gene inhibitor” as it can cleave the target RNA. In this series many trans-splicing ribozymes are engineered and patented for their vital catalytic activity. However here the focus has been given to recent patents on group I intron-derived transsplicing ribozymes, and their catalytic functions as therapeutics are discussed.

The antiproliferative and antitumor effect of leaf ribonuclease was tested in vitro on the human ML-2 tumor cell line and in vivo on athymic nude mice bearing human melanoma tumors. The antiproliferative activity of this plant ribonuclease in vitro studies was negligible. In the experiments in vivo a significant decrease of the tumor size, however was observed. From nucleases the mung bean nuclease (PhA) was studied first from nucleases. The antitumor effect of this enzyme on ML2 human tumor cell line was almost non-effective. However, significant antitumor activity was detected on human melanoma tumors in vivo. The antitumor effect of black pine pollen nuclease (PN) tested in vitro was also negligible. On the other side, in the experiments in vivo a significant decrease of the human melanoma tumor size was observed too. Recombinant plant nucleases of tomato (TBN1) and hop (HBN1) (submitted to patenting under no. PV 2008-384;Z7585) were isolated to homogeneity and examined for their antitumor effects and cytotoxicity. Although antiproliferative effects of both recombinant nucleases were not significant on the ML-2 cell culture in vitro, the nucleases were strongly cytostatic in vivo after their administration intravenously as stabilized conjugates with polyethylene glycol (PEG). Recombinant both nucleases were as effective against human melanoma tumors as previously studied pine pollen (PN) and mung bean nucleases and their effects were reached at about ten times lower concentrations compared to the use of bovine seminal RNase (BS-RNase).

Cancer has long been viewed as a heterogeneous population of cells. Cancerous cells may often originate from the transformation of normal stem cells, similar signaling pathways may regulate self-renewal in stem cells and cancer cells. The concept that cancer might arise from a rare population of cells with stem cell properties was proposed for more than a century. Cancer stem cell hypothesis has began to be accepted recently due to the advances in stem cell biology and the development of new animal models to measure self-renewal that drive tumorigenesis. Cancer stem cells have been identified and purified in a variety of tumors (blood, breast, brain, colon, lung, pancreas) using unique stem cell markers such as CD44, CD133 and aldehyde dehydrogenases. Cancer stem cell gene signatures have been examined. This review will discuss the evolution of cancer stem cell research and summarize the recent patents related to the cancer stem cell markers, the methods to detect and modulate cancer stem cells and cancer stem cell-targeted treatment. With the advances in cancer stem cell research, the new patent applications, particularly the new drugs on cancer stem cells treatments are expected to be increasing.

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.

Chemokines, a group of proinflammatory chemotactic cytokines, function to recruit leukocytes to inflammation sites, but they also play important roles in tumor growth, angiogenesis, organ sclerosis, and autoimmunity. In recent years, increasing evidence has accumulated to support the concept that thyroid epithelial cells (TEC) as well as the lymphocytes infiltrating into the thyroid are capable of producing CC and CXC chemokines. They, in turn, promote the initiation and maintenance of an inflammatory response, resulting in the development of autoimmune thyroiditis. This review focused on the role of chemokines in the pathogenesis in the two well-defined murine models of autoimmune thyroiditis, experimentally autoimmune thyroiditis (EAT) in DBA/1 and CBA/J mice and iodine-induced spontaneous autoimmune thyroiditis (SAT) in NOD.H-2h4 mice. Recent patents which focus on chemokines as novel therapeutic targets in autoimmune thyroiditis were also discussed in this review. Such study might improve our knowledge about the roles of chemokines in autoimmune thyroiditis.

ColE1-like plasmids constitute the most popular vectors for recombinant protein expression. ColE1 plasmid replication is tightly controlled by an antisense RNA mechanism that is highly dynamic, tuning plasmid metabolic burden to the physiological state of the host. Plasmid homeostasis is upset upon induction of recombinant protein expression because of non-physiological levels of expression and because of the frequently biased amino acid composition of recombinant proteins. Disregulation of plasmid replication is the main cause of collapse of plasmid-based expression systems because of a simultaneous increase in the metabolic burden (due to increased average copy number) and in the probability of generation of plasmid-free cells (due to increased copy number variation). Interference between regulatory elements of co-resident plasmids causes comparable effects on plasmid stability (plasmid incompatibility). Modulating plasmid copy number for recombinant gene expression aims at achieving a high gene dosage while preserving the stability of the expression system. Here I present strategies targeting plasmid replication for optimizing recombinant gene expression. Specifically, I review approaches aimed at modulating the antisense regulatory system (as well as their implications for plasmid incompatibility) and innovative strategies involving modulation of host factors, of R-loop formation, and of the timing of recombinant gene expression.

The patents annotated in this section have been selected from various patent databases. These recent patents are relevant to the articles published in this journal issue, categorized by significant fields of gene therapy methods, process and techniques involved.