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PubMed1994

The prediction of human exons by oligonucleotide composition and discriminant analysis of spliceable open reading frames.

Discriminant analysis is applied to the problem of recognition 5'-, internal and 3'-exons in human DNA sequences. Specific recognition functions were developed for revealing exons of particular types. The method based on a splice site prediction algorithm that uses the linear Fisher discriminant to combine the information about significant triplet frequencies of various functional parts of splice site regions and preferences of oligonucleotides in protein coding and intron regions (Solovyev, Lawrence, 1994). The accuracy of our splice site recognition function is about 97%. A discriminant function for 5'-exon prediction includes hexanucleotide composition of upstream region, triplet composition around the ATG codon, ORF coding potential, donor splice site potential and composition of downstream intron region. For internal exon prediction, we combine in a discriminant function the characteristics describing the 5'-intron region, donor splice site, coding region, acceptor splice site and 3'-intron region for each open reading frame flanked by GT and AG base pairs. The accuracy of precise internal exon recognition on a test set of 451 exon and 246693 pseudoexon sequences is 77% with a specificity of 79% and a level of pseudoexon ORF prediction of 99.96%. The recognition quality computed at the level of individual nucleotides is 89% for exon sequences and 98% for intron sequences. A discriminant function for 3'-exon prediction includes octanucleotide composition of upstream intron region, triplet composition around the stop codon, ORF coding potential, acceptor splice site potential and hexanucleotide composition of downstream region.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Simulation↗

PubMed1994

An improved system for exon recognition and gene modeling in human DNA sequences.

A new version of the GRAIL system (Uberbacher and Mural, 1991; Mural et al., 1992; Uberbacher et al., 1993), called GRAIL II, has recently been developed (Xu et al., 1994). GRAIL II is a hybrid AI system that supports a number of DNA sequence analysis tools including protein-coding region recognition, PolyA site and transcription promoter recognition, gene model construction, translation to protein, and DNA/protein database searching capabilities. This paper presents the core of GRAIL II, the coding exon recognition and gene model construction algorithms. The exon recognition algorithm recognizes coding exons by combining coding feature analysis and edge signal (acceptor/donor/translation-start sites) detection. Unlike the original GRAIL system (Uberbacher and Mural, 1991; Mural et al., 1992), this algorithm uses variable-length windows tailored to each potential exon candidate, making its performance almost exon length-independent. In this algorithm, the recognition process is divided into four steps. Initially a large number of possible coding exon candidates are generated. Then a rule-based prescreening algorithm eliminates the majority of the improbable candidates. As the kernel of the recognition algorithm, three neural networks are trained to evaluate the remaining candidates. The outputs of the neural networks are then divided into clusters of candidates, corresponding to presumed exons. The algorithm makes its final prediction by picking the best canadidate from each cluster. The gene construction algorithm (Xu, Mural and Uberbacher, 1994) uses a dynamic programming approach to build gene models by using as input the clusters predicted by the exon recognition algorithm. Extensive testing has been done on these two algorithms.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗

PubMed1993

Chromosome mapping and organization of the human beta-galactoside alpha 2,6-sialyltransferase gene. Differential and cell-type specific usage of upstream exon sequences in B-lymphoblastoid cells.

The human beta-galactoside alpha 2,6-sialyltransferase (EC 2.4.99.1) (SiaT-1) gene is localized to human chromosome 3 (q21-q28) by Southern analysis of somatic cell hybrids and by in situ hybridization of metaphase chromosomes. Comparative analysis between the human and the previously reported rat SiaT-1 genomic sequences demonstrates precise conservation of the intron/exon boundaries throughout the coding domains. Furthermore, there is extensive inter-species sequence similarity in some of the exons that contain information only for the 5'-leader regions. Human genomic sequences were also analyzed to reconcile reported differences in the 5'-untranslated region in SiaT-1 mRNAs. In cultured cell lines of the B-lineage, Reh, Nalm-6, Jok-1, Ball-1, Daudi, and Louckes, the study demonstrates that three upstream exons, Exons(Y+Z) and Exon(X), are mutually exclusively utilized, resulting in at least two distinct populations of SiaT-1 mRNA being synthesized. None of these exons is present in the SiaT-1 mRNA isotype expressed in HepG2 human hepatoma cells. In all B-lymphoblastoid cell lines examined, the basal level SiaT-1 mRNA is maintained by the expression of an isotype containing the Exons(Y+Z) sequence. The slightly smaller SiaT-1 mRNA, which contains the Exon(X) sequence but not Exons(Y+Z) sequence, is synthesized at a high level and found only in Jok-1, Daudi, and Louckes, the cell lines with mature B-cell phenotype. The study also provides further evidence that induced SiaT-1 expression accompanies the appearance of CDw75, a putatively sialylated cell surface epitope and a marker of human mature B-lymphocytes. The SiaT-1 induction is the result of the appearance of a novel form of SiaT-1 mRNA isotype.

Animals↗

PubMed1995

Characterization of revertant muscle fibers in Duchenne muscular dystrophy, using exon-specific monoclonal antibodies against dystrophin.

Most Duchenne muscular dystrophy (DMD) patients have genetic deletions or point mutations in the dystrophin gene that alter the reading frame of dystrophin mRNA. This causes early termination of translation, and no dystrophin (or, less commonly, a truncated N-terminal dystrophin fragment) is produced. In many DMD patients, however, a small proportion of muscle fibers show strong dystrophin staining, and these "revertant fibers" are thought to arise by a mechanism that restores the reading frame. Exon-specific monoclonal antibodies (mAbs) have now been used to determine, for the first time, which exons are removed, in order to correct the reading frame in individual muscle fibers. Thus, 15 revertant fibers in a DMD patient with a frameshift deletion of exon 45 were shown to correct the frameshift by the additional deletion of exon 44 (or perhaps exon 46 in some fibers) from the dystrophin mRNA, but not by larger deletions. This result was consistent with reverse transcription (RT)-PCR and sequencing of a minor dystrophin mRNA with an exon 43/46 junction in this biopsy. In a DMD patient with a frameshift deletion of exons 42 and 43, however, larger deletions than the minimum necessary were used to correct the frameshift. In this patient, who produces a half-size N-terminal dystrophin fragment in all fibers, we were able to show that the revertant dystrophin replaces the truncated dystrophin in revertant-fiber sarcolemma. The results are consistent with somatic mutations in revertant-fiber nuclei, which result in removal of additional exons from dystrophin mRNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

PubMed1994

Accelerated exon skipping of IRF-1 mRNA in human myelodysplasia/leukemia; a possible mechanism of tumor suppressor inactivation.

The transcription factor IRF-1 has been shown to function as a tumor suppressor. Here we report that a significant proportion of the IRF-1 mRNA detected in normal human hematopoietic cells and cultured cell lines lacks exon 2 (containing the AUG initiation codon) and 3 as a result of exon skipping. Surprisingly, when we examined the bone marrow and peripheral mononuclear cells from patients with myelodysplastic syndrome (MDS) or leukemia secondary to MDS, we could still detect the exon-skipped form but little or none of the intact IRF-1 mRNA. This appears to be the result of accelerated exon skipping since we could find no mutations within the exons and splicing junctions from these patients. The exon-skipped form of IRF-1 lacking exons 2 and 3 displayed neither DNA binding nor tumor suppressive activities. Thus this accelerated exon skipping may cause the inactivation of IRF-1 and thereby contribute to the development of human hematopoietic malignancies.

Cell Line↗

PubMed1993

Alteration of splice site selection by an exon mutation in the human glycophorin A gene.

We report the identification in human glycophorin A gene of a novel exon mutation that affects splice site selection. DNA mapping showed that the mutation has abolished a unique MspI site marking the exon III-intron 3 splice junction (ACCG/GT). Genomic sequencing confirmed the occurrence of a single G-->A transition at the terminal nucleotide position of exon III. Analysis of the mRNA composition demonstrated a partial inactivation of the altered 5' splice site as well as skipping of exons involving the alternative use of other constitutive splice sites. The full-length transcript with the cognate A change encodes a variant glycophorin with an arginine replacing a glycine at position 59 and defining the ERIK epitope, whereas the exon III-deleted transcript specifies a shorter glycophorin carrying the Sta antigen. Also identified were the misspliced mRNA species with exon I-IV and exon I-V connections generated by selection of 5' splice sites far distant from the mutated site. Although having a correct translation frame, the predicted polypeptides of such exon-skipping products were not assembled on the erythrocyte membrane probably due to the severe truncation of the signal sequence required for targeting and translocation. These observations reveal a new mechanism for antigenic diversity of human glycophorins.

Alternative Splicing↗

PubMed1993

A complete description of the EGF-receptor exon structure: implication in oncogenic activation and domain evolution.

In this paper, we report that the chicken Epidermal Growth Factor Receptor (EGF-R), encoded by the proto-oncogene c-erbB, is comprised of 28 exons and spans over 75 Kb. The four previously identified domains which make up the extracellular ligand binding region of the receptor are coded for by two copies of a 300 amino acid repeat. We have demonstrated that the 3' end of each repeat coincides with the 3' end of the last exon making up the repeat. This alignment suggests that an exon-duplication may have occurred in the ligand-binding region of the gene. The transmembrane domain is encoded within a single exon and the exon boundaries of the catalytic domain closely match those defined by structural homology with other kinases. Along with the 54 chicken splice sites, the region 5' to the first exon was also sequenced. The proposed promoter region is greater than 70% GC, contains five repeats of the consensus Sp1 binding sequence and does not have a CCATT or TATA box. In addition to the presence of these characteristic housekeeping features, expression analysis confirms the promoter activity of this region and four sets of TCC repeats similar to those found in the human EGF-R promoter have been identified. To our knowledge this represents the first complete description of the exon-intron structure of the EGF-receptor family. The elucidation of the EGF-R exon structure provides insight into the domain evolution of the receptor-kinases and the mechanisms for the oncogenic conversion of EGF-R in erythroleukemias and glioblastomas.

Amino Acid Sequence↗

PubMed1995

Reconstitution of exon-bridging activity with purified U2AF and U1 snRNP components.

For pre-mRNAs containing multiple introns, the exon definition hypothesis has been proposed to account for the interactions that specify relatively short exons and prevent inappropriate exon-skipping [1]. Support for this hypothesis includes the finding that naturally occurring, or engineered mutations in 5' splice sites that weaken base complementary to U1 snRNA result in exon skipping due to a decrease in upstream 3' splice site activity. The reciprocal effect is also observed. For example, we found previously that the selection of the alternatively spliced rat preprotachykinin exon 4 is improved under conditions in which the adjacent 5' splice site is converted to a site with strengthened base pairing to U1 snRNA [2]. In the latter study, 3' splice site activity is improved in parallel with strengthened U1 snRNP binding to the downstream 5' splice site. Subsequent RNA-protein crosslinking experiments have provided evidence for exon bridging interactions between U2AF bound to the 3' splice site and U1 snRNP bound to the downstream 5' splice site in the preprotachykinin substrates [3]; see Figure 1. U2AF, a polypyrimidine tract binding protein composed of 65 and 35 kD subunits, is required for U2 snRNP binding to the adjacent branch site [4], [5]. In this work we have reconstituted exon bridging activity with purified components. These results show that U1 snRNP in addition to U2AF are the two components required to reconstitute full activity in vitro. The purified system has been used to test variants of U2AF and U1 snRNP. Our results show that the U1-A and U1-C proteins are dispensable for exon bridging activity. In addition, the 35 kD subunit of U2AF appears to be dispensable, at least under certain conditions.

Animals↗

PubMed1998

Alternative pre-mRNA splicing of the sterol 27-hydroxylase gene (CYP 27) caused by a G to A mutation at the last nucleotide of exon 6 in a patient with cerebrotendinous xanthomatosis (CTX).

A recently identified G to A mutation at the last nucleotide of exon 6 of the sterol 27-hydroxylase gene (CYP 27) in a patient with cerebrotendinous xanthomatosis (CTX) was shown here to cause alternative pre-mRNA splicing of the gene. Northern blot analysis of the patient's RNA revealed a broadened band in the human CYP 27 mRNA region compared to that of the normal sample, indicating that there may exist differently spliced mRNA species in the patient. RT-PCR produced three fragments in the patient, one was full-length size and the other two were of smaller sizes. Sequence analysis confirmed that the nucleotide of the full-length size was identical to that of the normal full-length cDNA, except for the G to A mutation at codon 362, which corresponds to the last nucleotide of exon 6. One of the smaller size species lacked exon 6 and the other was absent from the 3' terminal 88 bp of exon 6 due to the use of an activated cryptic 5' splice site in exon 6. The correctly spliced mRNA harbouring the G to A mutation was responsible for the deficiency of the sterol 27-hydroxylase activity, as confirmed by transfection experiment. Transfection of constructed minigenes, with or without the mutation, showed that correctly spliced mRNA was observed in the normal minigene while the mutant minigene was differently spliced. This is the first report of a G to A substitution at the last nucleotide of an exon resulting in both normal and abnormal pre-mRNA splicings, including exon skipping and activating of a coding region cryptic 5' splice site. The results reveal a new molecular basis for the CTX and provide information on aberrant splicing of pre-mRNA in multi-exon genes.

Adult↗

PubMed1999

Protein kinase C modulation of recombinant NMDA receptor currents: roles for the C-terminal C1 exon and calcium ions.

Protein kinase C (PKC) positively modulates NMDA receptor (NMDAR) currents. In contrast to previous reports, this study determines the importance of individual exons in the mechanism underlying the potentiation process by examining the complete set of eight naturally occurring splice variants expressed in Xenopus oocytes both as homomers and as heteromeric NR1/NR2A or NR1/NR2B complexes. After PKC stimulation, homomeric currents demonstrated a high level of potentiation ( approximately 500% of untreated baseline currents) that reduced to a lower level ( approximately 300% of baseline) in variants containing the first C-terminal exon (C1). An ANOVA showed that only C1 and no other exon or interaction of exons determined the degree of NMDAR current modulation by PKC. When recordings were performed in solutions in which barium replaces calcium, only the lower form of potentiation was observed, regardless of the splice variant exon composition. This suggested an important role for calcium in the PKC modulation of homomeric NMDA splice variant currents in which the C1 exon also participates. The effectiveness of the C1 exon to reduce the higher form of potentiation is modulated by heteromeric assemblies with NR2A heteromers yielding smaller levels of potentiation and a larger C1 exon effect compared with NR2B heteromers. The heteromers demonstrated the higher form of potentiation even in the absence of calcium. Furthermore, calcium had different effects in the potentiation of the heteromers depending on the NR2 subunit. This study refines the region of the NR1 subunit involved in a modulation crucial to the function of NMDA receptors and provides evidence that the NR2A and NR2B subunits realize this modulation differentially.

Animals↗

PubMed2006

Functional analysis of splicing mutations and of an exon 2 polymorphic variant of SERPING1/C1NH.

Several sequence changes have been reported in hereditary angioedema patients in intron 2 of the SERPING1/C1NH gene, but their consequences on splicing have not been determined. We examined in cell transfection assays the consequences at the mRNA level of splicing mutations affecting either the +3 or the +5 donor site positions, or the conserved canonical splicing signals of exon 2, using mutant C1 inhibitor minigene constructs. Both intron 2 mutations, c.51+3A>G and c.51+5G>A, resulted in marked exon 2 skipping in these assays, but also yielded a large fraction of normal transcripts. We show that the c.51+3A>G mutation cosegregates with low C1 inhibitor protein levels in one family. Moreover, the second base of exon 2 of the SERPING1/C1NH gene is the site of a polymorphic variant, which has been proposed as a modifier of disease severity. We found that the c.-21C allele at this position yields low but significant levels of exon 2 skipping in transfected Hep G2 or Hep 3B cells, suggesting that this allele may contribute, at the RNA level, to more severe forms of angioedema. Furthermore, we describe a previously not detected alternative splicing of exon 3, found in peripheral blood cell mRNA but not in the liver or in hepatoma cell lines and we show that, in cultured monocytes of a patient carrying the c.51+3A>G mutation, this alternative splicing is shifted from exon 3 exclusion to skipping of both exons 2 and 3. The latter finding suggests that mutations affecting splicing of exon 2 of the SERPING1/C1NH gene may have different consequences in monocytes versus other cell types.

Adolescent↗

PubMed1986

An isolated beta 1 exon next to the DR alpha gene in the HLA-D region.

A cosmid clone containing the DR alpha gene and a beta 1 exon of a DR beta-related gene was isolated from a human cosmid clone bank made from the consanguineous DR7 cell line MANN. No other DR beta-related exons were found on this clone. The beta 1 exon was located about 15 kb away from the DR alpha gene in a tail-to-tail (3' to 3') orientation. The exon contained several deleterious mutations: a defective splice site at the 5' end, two translational frame shifts (a 1 bp deletion and a 1 bp insertion), and three extra cysteine residues. Nucleotide and amino acid sequence comparisons of the beta 1 exon indicated that although it is substantially different from other class II beta-chain genes, it is slightly more related to DR than to any other class II gene. The DR beta-related sequence was on a DNA fragment which showed no polymorphism on a panel of cell lines with Eco RI or Pst I. These Southern blots, however, revealed a related, polymorphic sequence in the human genome. Nucleotide sequences in the intron flanking the beta 1 exon shared greater sequence homology than the beta 1 exon itself when compared with the DR beta genomic sequence. The exon may play a role in the generation of variation in expressed class II beta-chain genes and it may be a relic of a different subset of class II products.

Base Sequence↗

PubMed1985

Complete structure of the hamster alpha A crystallin gene. Reflection of an evolutionary history by means of exon shuffling.

The eye lens contains a structural protein, alpha crystallin, composed of two homologous primary gene products alpha A2 and alpha B2. In certain rodents, still another alpha crystallin polypeptide, alpha AIns, occurs, which is identical to alpha A2 except that it contains an insertion peptide between residues 63 and 64. In this paper we describe the complete alpha A crystallin gene that has been cloned from DNA isolated from Syrian golden hamster. Evidence is provided that the alpha A gene is present as a single copy in the hamster genome. The detailed organization of the gene has been established by means of DNA sequence analysis and S1 nuclease mapping, revealing that the gene consists of four exons. The first exon contains the information for the 68 base-pair long 5' non-coding region as well as the coding information for the first 63 amino acids. The second exon encodes the 23 amino acid insertion sequence, the third exon codes for amino acid 87 to 127 of the alpha AIns chain, whereas the last exon encodes the C-terminal 69 amino acids and contains the information for the 523 base-pair long 3' non-coding region. The second exon is bordered by a 3' splice junction (A X G/G X C), which deviates from the consensus for donor splice sites (A X G/G X T). This deviation is found in both hamster and mouse. An internal duplication was detected in the first exon by using a DIAGON-generated matrix for comparison. By means of similar DIAGON-generated matrices it was confirmed that the amino acids coded for by the third and fourth exons are homologous to the small heat-shock proteins of Drosophila, Caenorhabditis and soyabean. The implications of the differential splicing and the evolutionary aspects of the detected homologies are discussed.

Animals↗

PubMed1988

Isolation of the osteonectin gene: evidence that a variable region of the osteonectin molecule is encoded within one exon.

A complementary DNA clone for bovine osteonectin was used to isolate the osteonectin gene from two libraries of bovine genomic DNA fragments. Two overlapping clones were obtained whose relationship was determined by restriction mapping and sequence analysis. The two clones contain the entire osteonectin coding region spanning approximately 11 kilobases of genomic DNA. The coding region of the gene was determined, by electron microscopy and DNA sequencing, to reside in nine exons. In addition, there is at least one 5' exon interrupted by an intron in the 5'-nontranslated sequence of the gene. Excluding this 5' exon and the 3'-terminal exon, the exons are small and approximately uniform in size, averaging 130 +/- 17 base pairs. Three of the exons at the 5' end of the gene were sequenced and appear to encode discrete protein domains. For example, the putative exon 2 contains the coding region for the leader peptide of the molecule. The amino-terminal protein sequence was determined for osteonectin extracted from human, rabbit, and chicken bone and compared with those for bovine, mouse, and pig osteonectin. These data suggest that osteonectin is highly conserved between species, interspecies changes being seen primarily at the amino terminus of the protein and specifically in the region encoded by putative exon 3 in the bovine gene.

Amino Acid Sequence↗

PubMed1999

c-kit proto-oncogene exon 8 in-frame deletion plus insertion mutations in acute myeloid leukaemia.

Genomic DNA from 60 cases of acute myeloid leukaemia (AML) was screened for mutations in the c-kit gene. DNA from all 21 exons was subjected to polymerase chain reaction (PCR) amplification and analysis by conformation sensitive gel electrophoresis (CSGE); exons showing altered CSGE patterns were then sequenced. Mutations were identified only in those patients with inv(16) (3/7 cases) or t(8;21) (1/2 cases) and comprised three in-frame deletion plus insertion mutations (exon 8) and one point mutation (exon 10, GTA --> ATA, Val530Ile). Exons 8 and 10 were then analysed in 31 further cases of inv(16) (n = 14) and t(8;21) (n = 17), revealing four additional exon 8 in-frame deletion plus insertion mutations, all of which were in cases of inv(16). All exon 8 in-frame deletion plus insertion mutations (n = 7) involved the loss or replacement of the codon for Asp419 which is highly conserved cross species and is located in the receptor's extracellular domain. The high frequency of the c-kit proto-oncogene exon 8 deletion plus insertion mutations in AML suggests an essential role for this region of the receptor's extracellular domain. The association with inv(16) invites speculation as to the link between these two changes in the pathogenesis of AML.

Acute Disease↗

PubMed1992

Genomic structure of DNA encoding the lymphocyte homing receptor CD44 reveals at least 12 alternatively spliced exons.

The CD44 molecule is known to display extensive size heterogeneity, which has been attributed both to alternative splicing and to differential glycosylation within the extracellular domain. Although the presence of several alternative exons has been partly inferred from cDNA sequencing, the precise intron-exon organization of the CD44 gene has not been described to date to our knowledge. In the present study we describe the structure of the human CD44 gene, which contains at least 19 exons spanning some 50 kilobases of DNA. We have identified 10 alternatively spliced exons within the extracellular domain, including 1 exon that has not been previously reported. In addition to the inclusion or exclusion of whole exons, more diversity is generated through the utilization of internal splice donor and acceptor sites within 2 of the individual exons. The variation previously reported for the cytoplasmic domain is shown to result from the alternative splicing of 2 exons. The genomic structure of CD44 reveals a remarkable degree of complexity, and we confirm the role of alternative splicing as the basis of the structural and functional diversity seen in the CD44 molecule.

Alternative Splicing↗

PubMed1997

The structure of the gene for murine CTP:phosphocholine cytidylyltransferase, Ctpct. Relationship of exon structure to functional domains and identification of transcriptional start sites and potential upstream regulatory elements.

Phosphatidylcholine (PC) is the most abundant eukaryotic phospholipid and serves critical structural and cell-signaling functions. CTP:phosphocholine cytidylyltransferase (CT) is the rate-limiting enzyme in the CDP-choline pathway of PC biosynthesis, which is utilized by all tissues and is the sole or major PC biosynthetic pathway in all non-hepatic cells. Herein, we present the complete structure of the murine CT (Ctpct) gene. One P1 genomic clone and six subsequent plasmid subclones were isolated and analyzed for the exon-intron organization of the Ctpct gene. The gene spans approximately 26 kilobases and is composed of 9 exons and 8 introns. The exons match the distinct functional domains of the CT enzyme: exon 1 is untranslated; exon 2 codes for the nuclear localization signal domain; exons 4-7 encompass the catalytic domain; exon 8 codes for the alpha-helical membrane-binding domain; and exon 9 includes the C-terminal phosphorylation domain. Two transcriptional initiation sites, spaced 35 nucleotides apart, were identified using 5'-rapid amplification of cDNA ends polymerase chain reaction. The 5' natural flanking region was found to lack TATA or CAAT boxes and to contain GC-rich regions, which are features typical of promoters of housekeeping genes. Several sites that have the potential to interact with transcription regulatory factors, such as Sp1, AP1, AP2, AP3, Y1, and TFIIIA, were identified in the 5'-region of the gene and found to be distributed in two distinct clusters. These data will provide the basis for future studies on the cis- and trans-acting factors involved in Ctpct gene transcription and for the creation of induced mutant mouse models of altered CT activity.

Animals↗

PubMed2002

[Deletion of P16 gene exon 2 in bronchofibroscopic brush-off cells of human lung carcinoma]

OBJECTIVE: To analyze the relationship between deletion of P16 gene exon 2 and lung cancer and to evaluate the possibility of detecting P16 gene exon 2 deletion in brush-off cell instead of resected lung cancer mass. METHODS: P16 gene exon 2 deletion in bronchofibroscopic brush-off cells of lesion side and corresponding normal side was detected through PCR-electrophoresis-Image. Image value of P16 Vs beta-actin <0.6 was considered as P16 gene exon 2 deletion. RESULTS: The rate of P16 gene exon 2 deletion in normal side was 0 (0/19), whereas in lesion side was 35.5%(11/31), there is a significant statistical difference (P<0.01). In SCLC (small -cell lung carcinoma) samples, the rate of P16 gene exon 2 deletion was 0(0/7). whereas in NSCLC (non-small cell lung carcinoma) samples, that was 50%(11/12)(P<0.05). CONCLUSION: P16 gene exon 2 deletion might be related to the oncogenesis and development of lung carcinoma, especially NSCLC. Brush-off cell specimens may replace surgical specimens in Detecting P16 gene exon 2 deletion.

Journal Article↗