Non-Receptor Tyrosine Kinases: Their Structure and Mechanistic Role in Tumor Progression and Resistance.

Protein tyrosine kinases (PTKs) function as key molecules in the signaling pathways in addition to their impact as a therapeutic target for the treatment of many human diseases, including cancer. PTKs are characterized by their ability to phosphorylate serine, threonine, or tyrosine residues and can thereby rapidly and reversibly alter the function of their protein substrates in the form of significant changes in protein confirmation and affinity for their interaction with protein partners to drive cellular functions under normal and pathological conditions. PTKs are classified into two groups: one of which represents tyrosine kinases, while the other one includes the members of the serine/threonine kinases. The group of tyrosine kinases is subdivided into subgroups: one of them includes the member of receptor tyrosine kinases (RTKs), while the other subgroup includes the member of non-receptor tyrosine kinases (NRTKs). Both these kinase groups function as an "on" or "off" switch in many cellular functions. NRTKs are enzymes which are overexpressed and activated in many cancer types and regulate variable cellular functions in response to extracellular signaling-dependent mechanisms. NRTK-mediated different cellular functions are regulated by kinase-dependent and kinase-independent mechanisms either in the cytoplasm or in the nucleus. Thus, targeting NRTKs is of great interest to improve the treatment strategy of different tumor types. This review deals with the structure and mechanistic role of NRTKs in tumor progression and resistance and their importance as therapeutic targets in tumor therapy.

hTERT Epigenetics Provides New Perspectives for Diagnosis and Evidence-Based Guidance of Chemotherapy in Cancer.

Strong epigenetic pan-cancer biomarkers are required to meet several current, urgent clinical needs and to further improve the present chemotherapeutic standard. We have concentrated on the investigation of epigenetic alteration of the hTERT gene, which is frequently epigenetically dysregulated in a number of cancers in specific developmental stages. Distinct DNA methylation profiles were identified in our data on early urothelial cancer. An efficient EpihTERT assay could be developed utilizing suitable combinations with sequence-dependent thermodynamic parameters to distinguish between differentially methylated states. We infer from this data set, the epigenetic context, and the related literature that a CpG-rich, 2800 bp region, a prominent CpG island, surrounding the transcription start of the hTERT gene is the crucial epigenetic zone for the development of a potent biomarker. In order to accurately describe this region, we have named it "Acheron" (Ἀχέρων). In Greek mythology, this is the river of woe and misery and the path to the underworld. Exploitation of the DNA methylation profiles focused on this region, e.g., idiolocal normalized Methylation Specific PCR (IDLN-MSP), opens up a wide range of new possibilities for diagnosis, determination of prognosis, follow-up, and detection of residual disease. It may also have broad implications for the choice of chemotherapy.

Epigenetics Meets CAR-T-Cell Therapy to Fight Cancer.

Based on the impressive success of Car-T-cell therapy in the treatment of hematological malignancies, a broad application for solid tumors also appears promising. However, some important hurdles need to be overcome. One of these is certainly the identification of specific target antigens on cancer cells. Hypomethylation is a characteristic epigenetic aberration in many tumor entities. Genome-wide screenings for consistent DNA hypomethylations in tumors enable the identification of aberrantly upregulated transcripts, which might result in cell surface proteins. Thus, this approach provides a new perspective for the discovery of potential new Car-T-cell target antigens for almost every tumor entity. First, we focus on this approach as a possible treatment for prostate cancer.

Use of small intestine submucosa as ureteral allograft in pigs

PURPOSE: The aim of the present study was to evaluate the biocompatibility of small intestine submucosa (SIS) in the reconstruction of the ureter in swine. MATERIALS AND METHODS: An experimental study was performed in 10 half-breed pigs weighing between 20 and 30 K, in which a previously prepared segment of SIS measuring approximately 2.0 cm was implanted in the upper third part of the right ureter. RESULTS: Of the 10 operated animals, one died 14 days after the surgery due to a dehiscence on the suture line of the implanted graft. The remaining 9 animals were submitted to ultrasound examination of the urinary tract and were sacrificed on the 40th postoperative day. The macroscopic evaluation showed no calculus, incrustation, fistula, abscesses or adhesions in the ureters with the graft. Microscopic evaluation with hematoxylin-eosin and Sirius red showed in the experimental area (graft) the presence of urothelium in 100 percent of the cases, collagen in 100 percent of the cases, and smooth muscle layer in 87.5 percent of the animals. In the area adjacent to the graft (proximal and distal), we observed 92.86 percent of urothelium, 42.86 percent of collagen and 71.43 percent of smooth muscle. In the contralateral ureter, it was found 100 percent of urothelium and smooth muscle and just 11.11 percent of collagen. The microscopic analysis of the kidneys whose ureters received the graft of SIS evidenced congestion in 55.55 percent, pelvic edema in 66.66 percent and interstitial nephritis in 77.78 percent. Hydronephrosis was present in 33.33 percent and chronic pyelonephritis in 44 percent. Only 1 animal presented total absence of glomerulus in the renal parenchyma. CONCLUSION: The SIS graft behaved as a biological tissue support, allowing the regeneration of the urothelium and smooth muscle grow, despite of chronic inflammatory process.