Clinical Utility of Functional RNA Analysis for the Reclassification of Splicing Gene Variants in Hereditary Cancer.

BACKGROUND: Classification of splicing variants (SVs) in genes associated with hereditary cancer is often challenging. The aim of this study was to investigate the occurrence of SVs in hereditary cancer genes and the clinical utility of RNA analysis. MATERIAL AND METHODS: 1518 individuals were tested for cancer predisposition, using a Next Generation Sequencing (NGS) panel of 36 genes. Splicing variant analysis was performed using RT-PCR and Sanger Sequencing. RESULTS: In total, 34 different SVs were identified, 53% of which were classified as pathogenic or likely pathogenic. The remaining 16 variants were initially classified as Variant of Uncertain Significance (VUS). RNA analysis was performed for 3 novel variants. CONCLUSION: The RNA analysis assisted in the reclassification of 20% of splicing variants from VUS to pathogenic. RNA analysis is essential in the case of uncharacterized splicing variants, for proper classification and personalized management of these patients.

Protective effect of mesenchymal stem cell-conditioned medium on hepatic cell apoptosis after acute liver injury.

The aim of this study was to investigate the role of Mesenchymal Stem Cell (MSC) conditioned medium (CM(MSC)) on apoptosis of cultured mouse primary hepatocytes after in vivo carbon tetrachloride (CCl4)-induced acute liver injury. The acute liver injury was induced by injecting CCl4 intraperitoneally in C57/BL6 mice. Hepatocytes were isolated by liver perfusion, cultured in a defined medium to maintain their differentiation and characterized by reverse transcriptase polymerase chain reaction (RT-PCR) using the hepatic cell specific genes albumin, hepatocyte nuclear factor 4 (HNF4) and cytokeratin 18 (CK18). CM(MSC) was generated from cultured bone marrow-derived MSCs (BM-MSCs). BM-MSCs were positive for CD73, CD90, CD44 by flow cytometry and able to differentiate into chondrocytes, adipocytes and osteocytes. Apoptosis was evaluated by both annexin V. CM(MSC) were examined by flow cytometry to detect MSC-derived annexin V- and CD54/CD44-positive microparticles (MPs). In the CCl4-CM(MSC) treated hepatocytes, interleukin-6 (IL-6) was increased on the first day of culture compared to control and CCl4 and was followed by upregulation of fibroblast-like-protein (FGL1) expression after 48 hrs. This was associated with a significant decrease of annexin V positive CCl4-CM(MSC) treated hepatocytes at day 3 post plating. Recombinant IL-6 was induced FGL1 expression in hepatocytes derived from CCl4-treated mice suggesting that CM(MSC), which is enriched also in microparticles, attenuates CCl4-induced early apoptosis in hepatocytes through activation of FGL1.

Establishment of an animal model for Waldenström's macroglobulinemia.

OBJECTIVE: Waldenström's macroglobulinemia (WM) is a low-grade lymphoplasmacytoid lymphoma characterized by production of monoclonal immunoglobulin M (IgM). The present study was undertaken with the aim of developing a novel nonobese diabetic/severe combined immunodeficient (NOD/SCID) mouse model of WM. MATERIALS AND METHODS: Pairs of bone particles derived from adult humans were successfully implanted intramuscularly in NOD/SCID mice. Each mouse was implanted with a bone fragment taken from a neoplastic disease-free individual in the one hind limb and with a different biopsy taken from a WM patient in the other. RESULTS: All mice implanted with the bone marrow core biopsies had increased levels of serum IgM 1 month following the implantation onward. Histopathologic and immunohistochemical analysis showed that in approximately half of the mice WM cells metastasized from the WM bone implant to the distantly implanted non-WM bone. Serum IgM value records of all mice correlated with histopathological observations and immunohistochemical analysis for neoplastic cell density and metastatic growth. CONCLUSION: Results obtained in the present study suggest that IgM-producing WM cells not only retained viability in the bone marrow of the WM bone biopsy, but also metastasized to the normal bone marrow of the distant bone implant. The mouse model reported here improves on existing models of WM by recapitulating the adult human bone marrow microenvironment of abnormal WM neoplastic cells.

Infection--an underappreciated cause of bone pain in multiple myeloma.

Bone pain, especially back pain, is a common presenting feature of myeloma patients. We report three multiple myeloma patients with exacerbations of back pain and referred shoulder pain resulting from vertebral infections. Two patients were treated with surgery, and one patient had computerized tomography-guided percutaneous needle aspiration for diagnostic purposes. All three patients received a prolonged course of antibiotics. Vertebral infection resolved with this treatment in all three patients without any recurrence. Previous dexamethasone therapy, together with an episode of bacteraemia, appears to be a predisposing factor for vertebral infection. Magnetic resonance imaging enabled the diagnosis in all three patients.