Molecular mapping of the chromosome 11 breakpoint of t(11;17)(q13;q21) in a t(11;14)(q13;q32)-positive B non-Hodgkin's lymphoma

Regulation of apoptosis by fau revealed by functional expression cloning and antisense expression

Functional expression cloning is a powerful strategy for identifying critical steps in biological pathways independently of prior assumptions. It is particularly suitable for the identification of molecules crucial to the control of apoptosis. Our screen for sequences suppressing T-cell apoptosis isolated a sequence antisense to fau (Finkel-Biskis-Reilly murine sarcoma virus (FBR-MuSV)-associated ubiquitously expressed gene). The fox gene in FBR murine osteosarcoma virus is also antisense to fau and several reports have indicated that fau displays tumour suppressor and oncogenic properties in different contexts. Our observations indicate that the fau antisense sequence suppresses expression of endogenous fau mRNA and produces resistance to apoptosis induced both by the glucocorticoid analogue dexamethasone' by ultraviolet radiation, and by the anticancer drug cisplatin. In all cases, colony-forming ability is protected, indicating that fau affects the critical events prior to commitment to cell death. Overexpression of fau in the sense orientation induces cell death, which is inhibited both by Bcl-2 and by inhibition of caspases, in line with its proposed role in apoptosis.

Identification and molecular characterization of TM7SF2 in the FAUNA gene cluster on human chromosome 11q13

In this report, the identification and molecular characterization of a novel gene, designated TM7SF2, is reported. This gene was found in the FAU neighboring area (FAUNA) to which other genes have been mapped previously. The FAUNA gene cluster is located at chromosome 11q13 between landmarks H4B and D11S2196E. The TM7SF2 gene contains eight coding exons, and their splice site consensus sequences are consistent with AG/GT rule. Northern blot analysis with a cDNA probe corresponding to TM7SF2 revealed varying expression levels of a 1.7-kb transcript in adult human heart, brain, pancreas, lung, liver, skeletal muscle, kidney, ovary, prostate, and testis, but no detectable expression in placenta, spleen, thymus, small intestine, colon (mucosal lining), or peripheral blood leukocytes. The open reading frame in the cDNA sequence codes for a protein of 590 amino acids that is rich in glycine (23%) and arginine (17%) residues in its amino-terminal half and contains seven transmembrane domains in its carboxy-terminal half. The transmembrane region of the putative TM7SF2 protein shows amino acid sequence similarity to those of the lamin B receptor and the C14/C24 sterol reductase.

Optimization of non-isotopic in situ hybridization: detection of the Y chromosome in paraformaldehyde-fixed, wax-embedded cat retina

A technique was developed to detect the Y chromosome in paraformaldehyde-fixed diethylglycoldiesterate-embedded cat retina. The Y chromosome specific DNA probe was labeled with digoxigenin through polymerase chain reaction incorporation. After treatment of paraformaldehyde-fixed, diethylglycoldiesterate-embedded tissue sections with deoxyribonucleic acid decondensation and proteolytic digestion, non-fluorescent, non-isotopic in situ hybridization was performed on the retina sections. Most extensive treatment was required for the outer nuclear layer while the inner nuclear layer required more extensive treatment than the retinal pigment epithelial cells. Under optimal pretreatment conditions, the male cat retina displayed black spots which specifically localized at the periphery of the nuclei, while the female cat retina showed negative staining for the Y chromosome specific probe. The technique allows observation of the Y chromosome signal with preservation of retinal morphology and thus may be a valuable tool to discriminate donor cells in retinal pigment epithelial cell and photoreceptor cell transplants.

Molecular breakpoints of t(11;14)(q13;q32) in multiple myeloma

We found a t(11;14)(q13;q32) translocation in six patients with multiple myeloma (MM) or plasma cell leukemia. In five of them, rearrangements of BCL1 and PRAD1 could be studied. Two patients showed a rearrangement only with the Prad1 probe, located 120 kb telomeric of the major translocation cluster. The three other patients lacked rearrangements with both Bcl1 and Prad1.

Cytogenetic abnormalities in the leukemic phase of non-Hodgkin lymphoma

We have carried out chromosome analysis in a series of 16 non-Hodgkin Lymphoma (NHL) cases in leukemic phase. The diagnoses in these patients based on histology and immunologic markers were as follows: follicular lymphoma (FL), 3 cases; mantle cell lymphoma (Mc), 4 cases; lymphoplasmacytic lymphoma (LPL), 8 cases, and large cell lymphoma, 1 case. We have shown that the t(14;18), t(11;14), and trisomy 12 retained their subtype association with FL, Mc, and LPL, respectively, as in their nonleukemic counterparts with one case of FL showing t(1;19)(q23;p13). Among the four LPL cases without trisomy 12, one case each showed t(12;14)(q13;q32), trisomy 14, t(1;3)(p34;q21), and del(3)(q21). The t(1;19) and t(12;14) may represent rare events in FL and LPL, respectively, and may be uniquely associated with the leukemic phase. The breakpoint 14q32 was the most common single breakpoint involved, sometimes involving both chromosome 14 homologues depicting its association with primary and secondary genetic events in the disease progression. In addition to the main abnormalities, we have shown additional complex abnormalities in 14 of 16 cases. Among these, chromosome 3 was the most commonly involved, affecting the short or long arm or the whole chromosome; 5 of the 16 cases involved breakpoint 3q21. The high incidence of additional abnormalities in these NHL in leukemic phase suggest an association with the development of leukemia and progression of the disease.