Fluorescence In Situ Hybridization (FISH) in Multiple Myeloma

Hemophagocytic lymphohistiocytosis as an onset of diffuse large B‑cell lymphoma: A case report

A 53-year-old male presented with a 1-month history of hyperpyrexia. The clinical manifestations revealed hemophagocytic lymphohistiocytosis (HLH). Although a lymph node biopsy could not be obtained, a bone marrow biopsy revealed the activated B-cell subtype of diffuse large B-cell lymphoma (DLBCL). After being treated with HLH-1994 (dexamethasone and etoposide), a rituximab-containing chemotherapy and target agents involving bortezomib, the patient achieved remission. To understand the molecular profile of patient, next-generation sequencing and MYD88 L265P mutation examinations were performed, and the patient was determined to be positive for the MYD88 L265P mutation. Reports of DLBCL with plasmacytic differentiation and a MYD88 innate immune signal transduction adaptor L265P mutation concurrent with HLH are rare. Early recognition, precise diagnosis and timely therapy are pivotal in improving patient prognosis. Furthermore, molecular profiling enables researchers to develop potential therapies aimed at the activated NF-κB and endoplasmic reticulum stress signaling pathways. The present study highlights this pathogenesis and provides suggestions for further individualized therapeutics.

Identification of novel breakpoints for locus- and region-specific translocations in 293 cells by molecular cytogenetics before and after irradiation

The human kidney embryonic 293 cell line (293 cells) is extensively used in biomedical and pharmaceutical research. These cells exhibit a number of numerical and structural chromosomal anomalies. However, the breakpoints responsible for these structural chromosomal rearrangements have not been comprehensively characterized. In addition, it is not known whether chromosomes with structural rearrangement are more sensitive to external toxic agents, such as ionizing radiation. We used G-banding, spectral karyotyping (SKY), and locus- and region-specific fluorescence in situ hybridization (FISH) probes designed in our lab or obtained from commercial vendor to address this gap. Our G-banding analysis revealed that the chromosome number varies from 66 to 71, with multiple rearrangements and partial additions and deletions. SKY analysis confirmed 3 consistent rearrangements, two simple and one complex in nature. Multicolor FISH analysis identified an array of breakpoints responsible for locus- and region-specific translocations. Finally, SKY analysis revealed that radio-sensitivity of structurally rearranged chromosomes is dependent on radiation dose. These findings will advance our knowledge in 293 cell biology and will enrich the understanding of radiation biology studies.