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Molecular Biology and Genetics |
Laboratory of Cancer Genetics, Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104 [C-X. L., S. M., N. M. L., N. A. L.], and Hamon Center for Therapeutic Oncology Research, The University of Texas Southwestern Medical Center, Dallas, Texas 75235 [E. F., J. D. M.]
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ABSTRACT |
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INTRODUCTION |
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The identification of several tumor suppressor genes (such as RB, PTEN, BRCA2, P16, and DPC4) was significantly facilitated by the discovery of homozygous deletions, marking the exact location of a gene on a chromosome (6, 7, 8, 9, 10) . Earlier, using RDA, a powerful methodology for finding differences between human genomic DNA samples, we performed a genome-wide screening for homozygous deletions in cancer cell lines of different origin (11) . One RDA probe, which was homozygously deleted in kidney cancer cell line UOK124 and bladder cancer cell line VM-CUB-2, was located on chromosome 2q. In this study, we describe positional cloning and characterization of a new candidate tumor suppressor gene that spans the homozygously deleted region. Preliminary results of mutation analysis demonstrated that this gene is inactivated at considerable frequency by biallelic genetic alterations in NSCLC cell lines but not in SCLC cell lines. The predicted gene product is highly homologous to human LRP1, a gigantic receptor, which mediates endocytosis of multiple proteins from the surface of a cell (12) . The high level of homology to LRP1 supports the notion that the putative receptor, encoded by a new gene, which we called LRP-DIT, may suppress tumor invasion and metastasis by antagonizing extracellular proteolysis and/or cell motility.
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MATERIALS AND METHODS |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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Physical Mapping.
YACs and BACs spanning the deleted region were identified by screening
of commercial libraries (Research Genetics, Huntsville, AL) using
primers to probe UOK124-6 (11)
. Additional BACs from the
region were identified by PCR screening using primers to exons 1 and 4
(see below). BACs were purified by chromatography on Qiagen columns
(Qiagen), and the ends of the DNA inserts were directly sequenced using
T7 and SP6 sequencing primers according to standard protocols. Primers
derived from the obtained BAC sequences were used for mapping of the
deletions by PCR of genomic DNAs from cancer cell
lines.5
CEPH YACs were tested for the presence of exons 1, 5, and 35 by PCR,
using the following primer sets: EX1F, 5'-CACACACGCTCTGCCTCCTCTCTC-3'
and EX1R, 5'-CCCAGCAGGAA-AGCCAAGGAAGTCAG-3'; EX5F,
5'-GCCCAAGATAAAGCTGCTTAG-AAATGATGCC-3' and EX5R,
5'-CTCTCTCTTCAAAGTCCATATTTCTGCTATACC-3'; and EX35F,
5'-TTTTAAAAGGCCAGGAAATA-CATT-TGTTAACAC-3' and EX35R,
5'-AGATATTCTTGATTTTGTCTCA-GAC-ATTACAGC-3'. The PCR conditions
were 1 min at 94°C, 1 min at 68°C, and 2 min at 72°C for 30
cycles, preceded by 3 min at 94°C and followed by 10 min at 72°C.
PCR was performed in a thermal cycler 480 (Perkin-Perkin-Elmer Corp.,
Foster City, CA), using the buffer described previously
(11)
. The negative reactions were repeated two times.
cDNA Cloning and Analysis of Gene Expression.
Exon trapping was performed using an Exon Trapping System kit (Life
Technologies, Gaithersburg, MD) according to recommendations of the
manufacturer. BACs 118K13, 328 I2, and 283 I2 were digested with
EcoRI and ligated into the trapping vector pSPL3. MAX
EFFICIENCY HB101 competent cells were transfected with the ligates,
grown in 10 ml of liquid LB medium, and used for plasmid preparation.
One mg of each DNA preparation was transfected into COS-7 cells with
LIPOFECTACE reagent. Total RNAs extracted from transfected cells were
used for cDNA synthesis and RT-PCR. Primary PCR products digested with
BstXI were reamplified, subcloned into the cloning vector
pAM10, and sequenced. Primers derived from the identified exon were
used for the 5' and 3' RACE of Marathon-Ready cDNAs using
Advantage-cDNA PCR kit, as recommended by the supplier (Clontech, Palo
Alto, CA). PCR products were subcloned into the pCR II vector
(Invitrogen, Carlsbad, CA) and sequenced, and primers derived from the
obtained sequences were used for reiteration of RACE. Analysis of the
LRP-DIT gene expression was performed by PCR of QuickClone
cDNAs (Clontech), using the following primer set: I223F,
5'-GGTACATGCAGCCAGACCTGCAGAAACAC-3' and I223R,
5'-AGCCTTGCAAGATCTGTTGTCTGGCTGC-3'. Two ng of each cDNA was amplified
for 35–40 cycles under conditions described for physical mapping,
using Advantage-GC cDNA kit (Clontech). Northern blotting was performed
according to standard procedures.
Identification and Mapping of Homozygous Deletions.
Primers derived from the cDNA sequence were used for cloning of
exon-intron boundaries by exon connection and PCR-based genomic
walking, using Human GenomeWalker and Advantage Genomic PCR kits
(Clontech). The PCR products were sequenced directly. Screening of a
panel of tumor DNAs for homozygous losses was performed by PCR under
conditions described for physical mapping, using the LRP-DIT
primer sets EX1F/EX1R (exon 1), EX5F/EX5R (exon 5), and EX35F/EX35R
(exon 35; see above). Homozygous deletions in cancer cell lines were
mapped by PCR of genomic DNAs, using primers flanking
LRP-DIT exons 2, 4, 7, and 10: EX2F,
5'-GTACTGCTCGTTCTGCCCATGTTCAGATC-3' and EX2R,
5'-TTCACATGTAAGGTAAATCCGAATGGCATGA-3' (exon 2); EX3F,
5'-CTCTGAGAACAAGAGCAGCACTCTTACAG-3' and EX3R,
5'-GGCAGGTTATAGGTTTTCTTTGAACTTTC-ATTAC-3' (exon 3); EX4F,
5'-CCAATCATATAAACTTTCTGGGAGA-ACAATCG-3' and EX4R,
5'-CACTGTAGAGCACATGGTAGGTGCTC-3' (exon 4); EX7F,
5'-GGATCAGATGCTAGATTGCACCTGTGATTC-3' and EX7R,
5'-GTCTGTAGTCTTATTTTCCACAACAACACTTGTC-3' (exon 7); and EX10F,
5'-GGTTTACACTCTTTTGCATTCGATTATGGTGC-3' and EX10R,
5'-AGTCTCATGTTATGACTGATGTTGATGCTGC-3' (exon 10). Southern blot
hybridization was performed according to standard protocols.
EcoRI digests of genomic DNAs were resolved on a 1% gel and
transferred to nylon membranes. Genomic DNA fragments, containing exons
1 and 5, were PCR amplified from human DNA, labeled by random priming,
and consecutively hybridized to the blot.
Screening for Transcript Abnormalities.
Total RNAs were prepared from a panel of lung cancer cell lines using
TRIzol reagent (Life Technologies), and cDNAs were synthesized by
random priming using SuperScript preamplification system (Life
Technologies) as recommended by the supplier, taking 1 µg of total
RNA per 20-µl reaction. One µl of cDNA preparation was taken into
50 µl of RT-PCR reaction, and testing of the LRP-DIT
transcript for abnormalities was performed as described for the
analysis of gene expression. The LRP-DIT primer sets were:
F1F, 5'-GTCAAGACACACGGGCGT-CTCGCTCG-3' and F1R,
5'-CCTTCGTCATACCCATCTGGGCAGTCC-3' (the 5'-end of the coding sequence);
F8F, 5'-GTAGTACACTTTGCTTGGCTATCCCAGG-3' and F8R,
5'-CCATCACAGCGCCACAAATCAGGAACGC-3'; F10F,
5'-GTCTGTTCCTGCCCTGAAGGACTTCAAC-3' and F10R,
5'-CCACTCATAGAGGCAGATTCAATGCGAGG-3' (the middle part of the coding
sequence); and F29F, 5'-GAGGAACTTGCGTACCATCAGTTCT-AGG-3' and F29R,
5'-TTGCTCATATTCACACTACAAAGGAATACG-TTG-3' (the 3'-end of the coding
sequence). The Advantage-GC cDNA kit (Clontech) was used for the F1
primer set. The LRP-DIT primer sequences used for mapping of
homozygous deletions by RT-PCR were A1F,
5'-GATGGGGACCCTGACTGCCCTGATG-3' and A1R,
5'-CCTTCCACAATGTGCAACAAA-TGGCGGC-3'. Primers for detection of
LRP1 transcript were: LRP1F,
5'-AGTGCTGCTCAGACGCAGCTCAAGTGTG-3' and LRP1R,
5'-CACAATCTTGCTGTCGACGAGCTTGGTG-3'.
Mutation and LOH Analysis.
LOH analysis was performed according to standard protocols
(13)
. Five tetranucleotide repeats from the 2q21
region were amplified for 30 cycles from genomic DNAs (50 ng) of paired
normal and cancer cells in the presence of radiolabeled dCTP. The
following sets of PCR primers were used: Tetra 14F,
5'-GTTCTTTGCATTAAAACTTACGGAA-TCCTAC-3' and Tetra 14R,
5'-GCGAGACCTGCAATGTGTACATCTACAC-3'; Tetra 30F,
5'-GTGAGTTAGAAAGGTTCTCATGCCATTC-3' and Tetra 30R,
5'-CACACTCCAAAACTGCATTTTATGCTCTCCTTC-3'; and primers for Whitehead STS
markers CHLC.GATA3H09 (Tetra 46),
CHLC.GGAA9B02 (Tetra 79), and
CHLC.GATA72F07 (Tetra 80). The PCR conditions
were 1 min at 94°C, 1 min at 65°C, and 2 min at 72°C for 30
cycles, preceded by 3 min at 94°C and followed by 10 min at 72°C.
Obtained PCR products were mixed with denaturing buffer, heated,
separated by electrophoresis on denaturing polyacrylamide gels (6%),
and visualized by autoradiography. Cancer samples displaying LOH were
selected based on complete loss of one of two alleles present in paired
normal control.
Mutation analysis was performed by direct sequencing of RT-PCR products spanning the whole LRP-DIT coding region. Portions of the transcript were amplified using the following sets of primers: F1F/F1R; A1F/A1R (see above); A2F, 5'-CAGCCAGCTGCACTGGCACTAGACC-3' and A2R, 5'-CGT-CG-CCATCACATTTCCACCGAGCTTGG-3'; A3F, 5'-GTAGTACACTTTGCT-TGGCTATCCCAGG-3' and A3R, 5'-CCACTCATAGAGGCAGATTCAATGCGAGG-3'; A4F, 5'-CACCCCAGGGCCATTGCTTTGGACC-3' and A4R, 5'-GGGCTAAGTTTTGGTCTGCCCACCACAG-3'; A5F, 5'-TTATTGGAT-CAGTTCGGGGAATGGAACC-3' and A5R, 5'-CCTGAATACAGTAAATAGCCTTCATGCCTG-3'; A6F, 5'-CAGGGACAATGGTGGCTGTAAGCA-ACTC-3' and A6R, 5'-GAGTTGTCTCCGCAGTCATTTTCTCCATCAC-3'; A7F, 5'-GTGGAAATGGTGAGTGCATTGACTAC-CAGC-3' and A7R, 5'-CCCATCTGTACAGAGGCACTTGTAAGTCC-3'; A8F, 5'-TGCAAAAATGGCAGGTGCATTCCCAGTGG-3' and A8R, 5'-CCACGGTGTCACATTTCCACCAGAATGG-3'; A9F, 5'-GGTGGTTGCAGTCATTTGTGCCTTT-TAGC-3' and A9R, 5'-CAGCTTACCACCACA-GTGATCTTCATCTG-3'; A10F, 5'-TCCATCCACGAGACCTCACAGA-TGCAG-3' and A10R, 5'-GGCACACGTAGTACTGACATCTGTCTC-3'; and A11F, 5'-GAGGAACTTGCGTACCATCAGTTCTAGG-3' and A11R, 5'-TTGCTCATATTCACACTACAAAGGAATACGTTG-3'. RT-PCR products were gel purified using Qiaquick gel purification kit (Qiagen), and sequencing was carried out with automated DNA sequencers (Applied Biosystems; model 373A/377) and dye termination chemistry (Amersham Pharmacia Biotech, Piscataway, NJ).6 Sequences were analyzed using the MacVector program (Eastman-Kodak, Bridgeport, NJ). Homo sapiens mRNA for LRP-DIT protein was deposited as GenBank accession number AF176832.
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RESULTS |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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. To estimate the size of the minimal region of deletion, three BACs
containing the probe (118K13, 328 I2, and 283 I2) were isolated from a
human genomic library, and the sequences of clone ends were determined.
PCR testing of the presence of these STSs in DNAs from cancer cell
lines UOK124 and VM-CUB-2 indicated that a minimal region of homozygous
loss is located within BACs 118K13 and 328 I2 and its size is <100 kb
(Fig. 1)
.
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cDNA Cloning and Analysis of Gene Expression.
The sequence of the identified exon was extended in both directions by
5' RACE and 3' RACE, using cDNA samples from fetal and adult kidneys,
fetal brain, and adult lung. Assembly of sequences obtained by multiple
reiterations of RACE generated a 16.5-kb transcript. Two translation
start codons, located at positions 862 and 973 bp, were detected in the
open reading frame, but only the second codon occurs in a strong
context. Therefore, it is likely used in the translation process. The
sequence surrounding this codon (ACAATGT) fits Kozak’s rule, and the
5'-untranslated region contains a GC-rich sequence (891–921 bp) and an
in-frame stop codon at position 859 bp. The use of the initiation codon
at position 973 bp predicts a coding region of 13,797 bp, which ends
with a TAA stop codon at position 14,769 bp. No alternatively spliced
messages were found in any RACE products from various tissues,
suggesting that a single transcript of a new gene encodes a giant
protein of 4,599 amino acids, corresponding to a hypothetical molecular
weight 
500,000 for the unglycosylated polypeptide chain (Fig. 2)
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The results of RT-PCR analysis and Northern blotting demonstrated that the LRP-DIT mRNA is expressed in fetal and adult kidney and brain, lung, heart, and liver (data not shown). A search of the expressed sequence tag databases led to identification of perfect matches of LRP-DIT cDNA to 17 ESTs, which are expressed in skeletal muscle, thyroid gland, and in the brain lesions of patients affected by multiple sclerosis.
Identification and Mapping of Homozygous Deletions in
LRP-DIT in Cancer Cell Lines.
Analysis of the exon-intron structure of LRP-DIT
demonstrated that this gene contains 91 exons spread over a 500-kb DNA
region (the data will be reported elsewhere), which presents a serious
obstacle for mutation analysis. To screen for additional homozygous
deletions in LRP-DIT, we determined the sequences of
exon-intron boundaries located within the BAC contig and tested the
presence of exons 1 and 5 (I233R) in a panel of 133 genomic DNAs from
cancer cell lines of different origin (Fig. 1)
. The results of PCR
amplification suggested the presence of homozygous deletions in 4 of 39
lung cancer cell lines (23 NSCLCs and 16 SCLCs) but not in bladder,
kidney, colorectal, prostate, and breast cancer samples. All four
homozygous losses, including deletion of exon 1 in line SK-MES-1 and
deletion of exon 5 in lines H520, H2122, and SK-LC-6, were discovered
in NSCLC cell lines, indicating that the frequency of homozygous loss
in LRP-DIT in these lines is at least 17% (4 of 23).
Screening for LRP-DIT transcript abnormalities (see next
section) led to the detection of an additional deletion of exon 5 in
NSCLC cell line HCC95. Detailed analysis of the presence of individual
exons in identified cell lines demonstrated that the DNAs of all lines
except for one (SK-MES-1) contained intragenic homozygous deletions
within the region flanked by exons 2 and 10 (Fig. 1)
.
To eliminate the possibility of PCR artifacts, genomic DNAs from lines
anticipated to have a deletion were tested for the presence of exons 1
and 5 by Southern blot hybridization (Fig. 3A)
. The absence of the signal observed in cancer DNA samples
was in complete agreement with the results of PCR. PCR amplification of
available normal DNAs matching lines UOK124 and H2122 confirmed the
presence of exon 5 in two of two cases. These data indicated that
homozygous deletions in lines UOK124 and H2122 were acquired in the
process of cultivation of cancer cells or during tumor development. To
determine the exact location of allelic deletions, five cancer cell
lines were analyzed by RT-PCR of a portion of the LRP-DIT
transcript spanning exons 2–10. Only shortened RT-PCR products (in
absence of normal ones) were detected in lines UOK124, HCC95, and
H2122. Two products of different sizes observed in each of these lines
were directly sequenced. Analysis of obtained sequences indicated that
allelic deletions in lines UOK124 and H2122 result in frameshifts, and
the deletions in line HCC95 lead to translation of truncated and
probably inactive receptors, missing the first two ligand-binding
domains and two EGF-precursor domains (Table 1)
. No detectable RT-PCR products were observed in line SK-MES-1,
suggesting that homozygous loss of exon 1 in this line is likely to
span the transcription control sequence, which explains loss of
LRP-DIT expression. Finally, the full-length RT-PCR product
(as well as the shortened one) was detected in one of five tested lines
(VM-CUB-2). We reasoned that one allelic deletion in this line is
located entirely within an intron of LRP-DIT and probably
does not lead to gene inactivation.
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). Amplification of two additional regions of
LRP-DIT mRNA located in the middle part of the transcript
demonstrated the absence of one or both RT-PCR products in these cell
lines. These results indicated that abnormal transcripts missing
portions of the LRP-DIT mRNA are predominantly expressed in
a considerable fraction of NSCLC lines. No transcript alterations were
detected by RT-PCR of a corresponding portion of homologous
LRP1 transcript, which served as an mRNA quality control,
suggesting that they are not caused by mRNA degradation. To determine
whether intragenic homozygous deletions in LRP-DIT
contributed to expression of abnormal transcripts, we tested the
presence of exon 5 in genomic DNAs of six NSCLC lines that display
transcript abnormalities. A new homozygous deletion was detected in one
of these (HCC95), suggesting the existence of alternative, yet to be
identified mechanism of gene inactivation in the rest of the lines. Further screening for transcript abnormalities of lung cancer cell lines expressing both ends of the LRP-DIT was performed by RT-PCR of a portion of the transcript that spans the region of homozygous loss (exons 2–10). In several tested lines, we detected predominant normal RT-PCR products, as well as less abundant, shortened RT-PCR products (data not shown). Analysis of sequences of shortened products obtained from lines H345, HCC827, and H157 showed the absence of exons 7, 4–7, and 4–10, respectively, suggesting that these transcript abnormalities probably arise as a consequence of aberrant splicing or intragenic deletions.
Mutation Analysis of LRP-DIT.
If LRP-DIT is a tumor suppressor gene, the
LRP-DIT allele retained in lung tumor cells, displaying
allelic loss at the locus, should contain an inactivating mutation.
Analysis of 16 lung cancer cell lines revealed allelic losses at the
locus in nine lines (56%). To search for nucleotide substitutions in
LRP-DIT, we directly sequenced RT-PCR products spanning the
coding region in four NSCLC and five SCLC lines expressing the gene.
Two homozygous nucleotide substitutions (leading to a Leu
Phe change
at codon 766 and a nonconservative ArgCys change at codon 3157) were
identified in metastatic NSCLC cell line H1770 displaying LOH at 2q21
(Fig. 4)
. Sequencing of the corresponding PCR products amplified from genomic
DNAs demonstrated that both substitutions were present in tumor DNA but
not in paired lymphoblastoid DNA and the remaining cancer cell lines,
indicating that these changes represent acquired somatic
mutations.
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DISCUSSION |
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Studies of seven cancer cell lines containing homozygous
deletions within LRP-DIT demonstrated that all deletions
except for one (in bladder cancer cell line VM-CUB-2) are likely to
lead to complete gene inactivation attributable to loss of
transcription control elements, frameshifts, or translation of only
truncated and probably inactive receptor (Table 1)
. Although the exact
location of deletion breakpoints was not examined in two cases (NSCLC
lines SK-LC-6 and H520), homozygous losses of exons 4–5 in these lines
suggest inactivation of LRP-DIT attributable to protein
truncation and/or frameshifts.
Analysis of the location of two putative missense mutations
identified in NSCLC line H1770 indicates that the nonconservative
ArgCys change at codon 3157 of LRP-DIT resides within the stretch of
nine amino acids that is well conserved in the homologous LDL receptor.
Inherited missense mutations detected in this low-density lipoprotein
receptor sequence in patients with familial hypercholesterolemia were
shown to result in translation of a partially misfolded protein, which
is not transported from the endoplasmic reticulum to the Golgi
(15)
. Because there is a possibility that the ArgCys
substitution in LRP-DIT may lead to formation of an additional
disulfide bond causing protein misfolding, this mutation may result in
partial or complete absence of LRP-DIT on the cell surface. It is also
conceivable that the identified mutations in LRP-DIT are neutral. In
this case, homozygous deletions and changes in gene transcription are
predominant types of molecular alterations, leading to inactivation of
LRP-DIT. Such a mechanism of inactivation is not
unprecedented because it has already been demonstrated in the
DMBT1 and P16 genes (9
, 10)
.
Analysis of LRP-DIT expression by immunohistochemical methods is likely
to be useful for final evaluation of these possibilities.
Marked differences in the frequency of allelic losses at 2q between early and advanced NSCLC specimens (4) support the hypothesis that inactivation of LRP-DIT may play an important role at late stages of NSCLC progression or metastasis. Homology searches indicate that LRP-DIT codes for a new member of a family of gigantic cell surface receptors, which includes LRP1 and the evolutionary conserved protein LRP2/gp330/megalin (12) . A high level of homology of the LRP-DIT protein to LRP1 supports the notion that these endocytic receptors share many (or most) of their substrates, as was already demonstrated for LRP1 and LRP2 proteins (16) . Recent studies indicate that 1 of >20 known LRP1 ligands is urokinase plasminogen activator, a serine protease, which plays a key role in activation of extracellular proteolytic cascades and regulation of adhesion, motility, and chemotaxis of cancer cells during tumor invasion and metastasis (17) . This raises an intriguing possibility that the newly discovered receptor may suppress extracellular proteolysis and/or motility of cancer cells via endocytosis of urokinase plasminogen activator. Testing of this hypothesis in functional studies as well as identification of additional ligands of LRP-DIT are likely to be useful for elucidation of the role of this receptor in cell functioning.
In summary, we have demonstrated that nearly one-half of NSCLC cancer cell lines, which are routinely obtained from advanced lung tumors, are probably null for LRP-DIT as a consequence of genetic alterations or predominant expression of abnormal transcript. This frequency is likely to be an underestimate, since NSCLC cell lines were not systematically screened for homozygous deletions and transcript alterations because of the large size of the transcript. Screening for genetic alterations in LRP-DIT in fresh tumor specimens, functional studies of the gene encoded receptor, and analysis of the consequences of LRP-DIT inactivation in knock-out mice will be necessary for final evaluation of this candidate gene as a bona fide tumor suppressor.
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ACKNOWLEDGMENTS |
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FOOTNOTES |
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1 This work was supported by the NIH Grants
CA64534 (to N. A. L.), P50 CA70907 (to J. D. M.), and a grant from
the G. Harold and Leila Y. Matthews Foundation (to J. D. M.). 
2 To whom requests for reprints should be
addressed, at the University of Pennsylvania, 713 A
Stellar-Chance, 422 Curie Boulevard, Philadelphia, PA 19104-6100.
Phone: (215) 573-9575; Fax: (215) 573-7699; E-mail: lisitsyn{at}mail.med.upenn.edu
3 The abbreviations used are: NSCLC, non-small
cell lung cancer; LOH, loss of heterozygosity; RDA, representational
difference analysis; RACE, rapid amplification of cDNA ends; BAC,
bacterial artificial chromosome; YAC, yeast artificial chromosome; LRP,
lipoprotein receptor-related protein; LRP-DIT, LRP-deleted in tumors;
RT-PCR, reverse transcription-PCR; EGF, epidermal growth factor.
4 A list is available upon request.
5 Sequences are available upon request.
6 The list of internally located sequencing
primers is available upon request.
Received 10/12/99. Accepted 2/ 3/00.
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REFERENCES |
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TopABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSIONREFERENCES |
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2-macroglobulin receptor. Annals NY Acad. Sci., 737: 114-123, 1994.[Medline]
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Y. Li, J. M. Knisely, W. Lu, L. M. McCormick, J. Wang, J. Henkin, A. L. Schwartz, and G. Bu Low Density Lipoprotein (LDL) Receptor-related Protein 1B Impairs Urokinase Receptor Regeneration on the Cell Surface and Inhibits Cell Migration J. Biol. Chem., October 25, 2002; 277(44): 42366 - 42371. [Abstract] [Full Text] [PDF]
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C.-X. Liu, Y. Li, L. M. Obermoeller-McCormick, A. L. Schwartz, and G. Bu The Putative Tumor Suppressor LRP1B, a Novel Member of the Low Density Lipoprotein (LDL) Receptor Family, Exhibits Both Overlapping and Distinct Properties with the LDL Receptor-related Protein J. Biol. Chem., July 27, 2001; 276(31): 28889 - 28896. [Abstract] [Full Text] [PDF]
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