UGRP1, a Uteroglobin/Clara Cell Secretory Protein-Related Protein, Is a Novel Lung-Enriched Downstream Target Gene for the T/EBP/NKX2.1 Homeodomain Transcription Factor

A novel gene that is down-regulated in lungs of T/ebp/Nkx2.1-null mouse embryos has been identified using a suppressive-subtractive hybridization method. The gene product is a secreted protein, forms a homodimer, and exhibits an amino acid sequence similar to that seen in the uteroglobin/Clara cell secretory protein family of proteins. This gene, designated Ugrp1 (uteroglobin-related protein 1), consists of three exons and two introns and produces three transcripts by alternative splicing. The Ugrp1 gene was localized by fluorescence in situ hybridization to mouse chromosome 18 at region 18C-D; this region is homologous with human 5q31-34, where one of the asthma susceptibility genes has been assigned. UGRP1 mRNA is predominantly expressed in the lung, with low levels of expression in the thyroid. Expression in the lung is detectable as early as embryonic day 12.5 and increases markedly by embryonic day 16.5. In T/ebp/Nkx2.1-null embryo lungs, UGRP1 expression was significantly reduced as assessed by RT-PCR analysis. Cotransfection assays using a T/EBP/NKX2.1 expression construct with Ugrp1 promoter-luciferase reporter constructs confirmed that T/EBP/NKX2.1 regulates Ugrp1 gene activity at the transcriptional level. Thus, Ugrp1 is a downstream target gene for the T/EBP/NKX2.1 homeodomain transcription factor. Changes in UGRP1 mRNA levels in lungs from antigen-sensitized mice suggest the possible involvement of UGRP1 in inflammation

A Polymorphism in the Human UGRP1 Gene Promoter That Regulates Transcription Is Associated with an Increased Risk of Asthma

Several traits associated with asthma phenotypes, such as high total serum immunoglobulin E and bronchial hyperresponsiveness, have been linked by numerous genome-screen studies and linkage analyses to markers on human chromosome 5q31-q34. In the present article, we describe UGRP1 (encoding uteroglobin-related protein 1) as one of asthma-susceptibility genes that is located on chromosome 5q31-q32. UGRP1 is a homodimeric secretory protein of 17 kDa and is expressed only in lung and trachea. The G→A polymorphism was identified at −112 bp in the human UGRP1 gene promoter. The −112A allele is responsible for a 24% reduction in the promoter activity in relation to the −112G allele, as examined by transfection analysis. Electrophoretic mobility-shift analysis revealed that an unknown nuclear factor binds to the region around −112 bp. The binding affinity with the −112A oligonucleotide was reduced by approximately one half, as compared with the −112G oligonucleotide. In a case-control study using 169 Japanese individuals (84 patients with asthma and 85 healthy control individuals), those with a −112A allele (G/A or A/A) were 4.1 times more likely to have asthma than were those with the wild-type allele (G/G)

SMAD5 Gene Expression, Rearrangements, Copy Number, Amplification at Fragile Site FRA5C in Human Hepatocellular Carcinoma

AbstractSignaling by the transforming growth factor (TGF)family members is transduced from the cell surface to the nucleus by the Smad group of intracellular proteins. Because we detected alterations on the long arm of chromosome 5, we examined the status of the SMAD5 gene in human hepatocellular carcinoma (HCC) cell lines and primary HCC. In 16 cell lines, chromosome alterations of chromosome 5 were observed in nine cell lines by fluorescence in situ hybridization (FISH), an increase in SMAD5 gene copy number relative to the ploidy level was found in eight lines. The breakpoints in unbalanced translocations and deletions frequently occurred near the SMAD5 locus, but apparently did not cause loss of SMAD5. In one cell line, where comparative genomic hybridization showed DNA copy number gain confined to the region 5831, we detected by FISH high-level amplification of the SMAD5 gene located within the fragile site FRA5C. Semiquantitative polymerase chain reaction did not reveal changes in SMAD5 DNA levels in 15 of 17 primary HCC specimens. In 17 HCC cell lines, SMAD5 mRNA levels were either maintained or upregulated by an increase in gene dosage or another mechanism. Collectively, our results show that SMAD5 undergoes copy number gain and increased expression, rather than loss of expression, therefore suggest that this gene does not act as a tumorsuppressor gene in HCC. The Hep-40 HCC cell line with high-level amplification and significant overexpression of SMAD5 may be useful in studying the interaction of SMAD5 with other genes

CANCER RESEARCH 61, 8068 -- 8073, November 15, 2001]

We recently reported the cloning of WWOX, a gene that maps to the common fragile site FRA16D region in chromosome 16q23.3-24.1. It was observed that the genomic area spanned by WWOX is affected by chromosomal translocations and homozygous deletions. Furthermore, the high incidence of allelic loss in breast, ovarian, prostate, and other cancers affecting this region suggests that WWOX is a candidate tumor suppressor gene. Expression of WWOX is highly variable in breast cancer cell lines, with some cases showing low or undetectable levels of expression. In this report, we demonstrate that ectopic WWOX expression strongly inhibits anchorage-independent growth in soft agar of breast cancer cell lines MDA-MB-435 and T47D. Additionally, we observed that WWOX induces a dramatic inhibition of tumorigenicity of MDA-MB-435 breast cancer cells when tested in vivo. We also detected the common occurrence of aberrant WWOX transcripts with deletions of exons 5-- 8 or 6 -- 8 in various carcinoma cell lines, multiple myeloma cell lines, and primary breast tumors. These aberrant mRNA forms were not detected in normal tissues. Interestingly, we further observed that proteins encoded by such aberrant transcripts display an abnormal nuclear localization in contrast to the wild-type WWOX protein that localizes to the Golgi system. Our data indicate that WWOX behaves as a potent suppressor of tumor growth and suggest that abnormalities affecting this gene at the genomic and transcriptional level may be of relevance in carcinogenesis