TITLE:
Molecular Profile of Human Serine Palmitoyltransferase-1 Proximate of Chromosome 9 Disease Susceptibility Gene Cluster in Inflammatory Cancer Cell Lines
AUTHORS:
Tokunbo Yerokun, Tamra Neblett, Chénel Johnson
KEYWORDS:
Cytogenetic Band, Functional Genomics, Human Chromosome 9, Microsatellite Instability, Serine Palmitoyltransferase-1
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.5 No.10,
September
4,
2014
ABSTRACT:
Background: Over 1100
genes have been annotated for human chromosome 9, including disease genes
implicated in inflammation, atherosclerosis, cancer and neurodegeneration. The
serine palmitoyltransferase-1, SPTLC1, gene is at the 9q22.2 cytogenetic band,
a high G+C content region with common genetic alterations sufficient to modify
cellular behavior. The sequence is highly conserved among diverse species from
bacteria to humans, including a recently discovered 126 nucleotide alternate
open reading frame, AltORF. The protein encoded by the reading frames has
domains of biological interest and considerable overlapping molecular functions
associated with cellular behavior and cancer progression. Methods: Here we
examined molecular features of SPTLC1 in a group of inflammation associated
cancer cell lines SKN-SH, MDA-PCa, Glioma LN18, PC3 and 647V. Subcellular
localization of SPTLC1 was assessed by immunofluorescence microscopy and
recombinant green fluorescent protein expression. In addition, PCR, DNA
sequencing and bioinformatics analysis were used for molecular profiling of the
SPTLC1 genomic and reverse transcribed cDNA fragments. Results: SPTLC1 is detected
in all cell lines examined, with intense peri-nuclear staining, consistent with
localization in the cytoplasm. Genomic DNA sample, but not the cD NA of SKN
cells could be amplified with an AltORF primer set. The PC3 and MDA-PCa cancer
cell lines which are both of prostate origin, show differences in SPTLC1 PCR
amplification. Similar levels of SPTLC1 AltORF transcripts were detected by
quantitative RT-PCR in all cell lines, except the PC3 cell line with low
transcript level whose cDNA did not generate nucleotide base sequence
information. Conclusions: This is the first reported transcriptional expression
of the SPTLC1 AltORF for the inflammation associated human cancer cell lines.
Interestingly, it is proximate of oncogenic cancer susceptibility genes and distal
of tumor suppressor genes, the high content of short nucleotide repeats in the
SPTLC1 AltORF sequence suggesting the region may be genetically unstable. This
nominal functional genomics report on the human SPTLC1 AltORF will contribute
to compiling a more detailed SPTLC1 gene ontology and is expected to help shed
more insight into unique molecular attributes of SPTLC1 in the context of
cancer cell behavior, malignant progression and the design of treatment for
inflammation associated cancers.