Identification of a novel interleukin-15 (IL-15) transcript isoform generated by alternative splicing in human small cell lung cancer cell lines.
IL-15 is a cytokine promoting growth and differentiation of T, B and NK lymphocytes. By RT-PCR analysis, using primers allowing amplification of the entire IL-15 mRNA coding region, 9/11 small cell lung cancer (SCLC) cell lines displayed detectable IL-15 gene expression. In addition to the expected band sizing 524 bp, a larger band was also observed. Cloning and sequence analysis of the larger cDNA from two SCLC cell lines revealed a size of 643 hp due to the presence of additional 119 hp within the previously reported IL-15 cDNA sequence. The 119 hp sequence matched with an IL-15 genomic sequence downstream the IL-15 second coding exon and may represent a previously unreported alternative exon (exon A). The SCLC-associated IL-15 mRNA isoform has a shorter open reading frame (ORF) due to stop codons in exon A, followed by a new AUG codon. The predicted IL-15 precursor protein displays a shorter signal peptide but shares the same aminoacidic composition of mature IL-15 protein. A possible functional role of IL-15, different from 'IL-2-like' activity, in human tumours, is suggested.
Meazza
R
R
Instituto Nazionale per la Ricerca sul Cancro, Genova Italy.
Verdiani
S
S
Biassoni
R
R
Coppolecchia
M
M
Gaggero
A
A
Orengo
A M
AM
Colombo
M P
MP
Azzarone
B
B
Ferrini
S
S
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D018288:Carcinoma, Small Cell / Q000235:genetics* / Q000378:metabolism*; D005091:Exons; D006801:Humans; D019409:Interleukin-15; D007378:Interleukins / Q000096:biosynthesis* / Q000235:genetics*; D007536:Isomerism; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D019409:Interleukin-15; D007378:Interleukins; D012333:RNA, Messenger