title: Down regulation of 3p genes, LTF, SLC38A3 and DRR1, upon growth of human chromosome 3-mouse fibrosarcoma hybrids in severe combined immunodeficiency mice.
abstract: We have applied a functional test for tumour antagonizing genes based on human chromosome 3 (chr3)-mouse fibrosarcoma A9 MCHs that were studied in vitro and after growth as tumours in severe combined immunodeficiency (SCID) mice. Previously, we reported that 9 out of the 36 SCID-tumours maintained the transferred chr3 ("chr3+" tumours), but lost the expression of the known human TSG fragile histidine triad gene (FHIT) in contrast to 14 other 3p-genes examined. Here we report the results of the duplex RT-PCR analysis of 9 "chr3+" tumours and 3 parental MCHs. We have examined the expression of 34 human 3p-genes from known cancer-related regions of instability, including 13 genes from CER1 defined by us previously at 3p21.33-p21.31 and 10 genes from the LUCA region at 3p21.31. We have found that in addition to FHIT, expression of the LTF gene from CER1 at 3p21.33-p21.31 was lost in all 9 tumours analyzed. The transcript of the solute carrier family 38 member 3 gene (SLC38A3) gene from LUCA region at 3p21.31 was not found in 8 and was greatly reduced in 1 out of these 9 tumours. Expression of the down-regulated in renal cell carcinoma gene (DRR1) gene at 3p14.2 was lost in 7 and down regulated in 2 "chr3+" tumours. In the SCID-tumour derived cell lines treatment with 5-aza-2'-deoxycytidine restored the mRNA expression of LTF, indicating the integrity of DNA sequences. Notably that transcription of the LTF and 2 flanking genes, LRRC2 and TMEM7, as well as transcription of the SLC38A3 gene, were also impaired in all 5 RCC cell lines analyzed. Our data indicate these genes as putative tumour suppressor genes.
authors.affiliation: Microbiology and Tumour Biology Center, Karolinska Institute, Stockholm, Sweden.
authors.forename: Irina D
authors.initials: ID
authors.lastname: Kholodnyuk
authors.forename: Svetlana
authors.initials: S
authors.lastname: Kozireva
authors.forename: Maria
authors.initials: M
authors.lastname: Kost-Alimova
authors.forename: Vladimir
authors.initials: V
authors.lastname: Kashuba
authors.forename: George
authors.initials: G
authors.lastname: Klein
authors.forename: Stefan
authors.initials: S
authors.lastname: Imreh
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002893:Chromosomes, Human, Pair 3; D015536:Down-Regulation; D005354:Fibrosarcoma / Q000235:genetics*; D016147:Genes, Tumor Suppressor; D006801:Humans; D007781:Lactoferrin / Q000235:genetics*; D026901:Membrane Transport Proteins / Q000235:genetics*; D051379:Mice; D016513:Mice, SCID; D009687:Nuclear Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019831:Sodium-Calcium Exchanger / Q000235:genetics*
chemical_list: C403503:FAM107A protein, human; D026901:Membrane Transport Proteins; D009687:Nuclear Proteins; C101832:SLC38A3 protein, human; D019831:Sodium-Calcium Exchanger; D007781:Lactoferrin