BAC-FISH assays delineate complex chromosomal rearrangements in a case of post-Chernobyl childhood thyroid cancer.

Abstract

Structural chromosome aberrations are known hallmarks of many solid tumors. In the papillary form of thyroid cancer (PTC), for example, activation of the receptor tyrosine kinase (RTK) genes, RET and neurotrophic tyrosine kinase receptor type I (NTRK1) by intra-and interchromosomal rearrangements has been suggested as a cause of the disease. However, many phenotypically similar tumors do not carry an activated RET or NTRK-1 gene or express abnormal ret or NTRK-1 transcripts. Thus, we hypothesize that other cellular RTK-type genes are aberrantly expressed in these tumors. Using fluorescence in situ hybridization-based methods, we are studying karyotype changes in a relatively rare subgroup of PTCs, i.e., tumors that arose in children following the 1986 nuclear accident in Chernobyl, Ukraine. Here, we report our technical developments and progress in deciphering complex chromosome aberrations in case S48TK, an aggressively growing PTC cell line, which shows an unusual high number of unbalanced translocations.

Kinase Expression and Chromosomal Rearrangements in Papillary Thyroid Cancer Tissues: Investigations at the Molecular and Microscopic Levels

“…2A), the cell line S48TK had shown numerous translocations among them several complex translocations including two marker chromosomes, m1 and m2, that carried chromosome 9 derived material (6, 20, 22). Our SKY analysis suggested that m1 is the product of a t(7;9;15), while m2 might have been the results of insertion of chromosome 9 material into a der(8)t(8;15) (Fig.…”

“…A preliminary molecular cytogenetic analysis of rearrangements involving the long arm of chromosome 1 in cell line S48TK has been published recently (20). Hybridization of BAC probes that bound either proximal or distal of the two candidate genes NTRK1 and TPM3 could demonstrate two marker chromosomes, one that appear to carry an inversion of the critical region between 144 Mbp and 155 Mbp, while the second marker chromosome showed hybridization pattern indicative of multiple copies of the same region (20). Further fine mapping and delineation of the chromosome 1-specific breakpoints has been initiated.…”

“…For initial screening of S48TK metaphases, we selected six BAC clones for the chromosome 9 from the Roswell Park Cancer Institute (RPCI) library RP11 (Table 1) using information in publicly available databases (http://genome.ucsc.edu/ and http://www.ncbi.nlm.nih.gov/gquery/gquery.fcgi) (25). For DNA isolation and preparation of DNA probes from individual clones, BAC DNA was isolated from 10 ml bacterial overnight cultures containing 12.5 μg/ml chloramphenicol (Sigma, St. Louis, MO) using an alkaline lysis protocol and precipitation in 2-propanol DNA (15, 20, 24). Then, the DNA was extracted once with phenol: chloroform, precipitated again with 2-propanol, and resuspended in 20-40 μl sterile water.…”

“…Like NTRK1, TPM3 also maps to chromosome 1q. We previously described some of our cytogenetic studies of chromosome 1 rearrangements in PTC (12, 20-21), and in this communication we will touch only briefly on these relatively rare changes involving the long arm of chromosome 1 in chPTC (18-19). …”

Supremacy of modern morphometry in typing renal oncocytoma and malignant look-alikes

“…Immunohistochemistry has gained a leading role in tumour typing and prognostication (Kwan et al 2009;Sun et al 2014;Huber et al 2014). Numerous protein targets are currently available for a multitude of different tumours.…”