In both males and females,
lung cancer is one of the most lethal
cancers worldwide and accounts for >30% of
cancer-related deaths. Despite advances in
biomarker analysis and
tumor characterization, there remains a need to find suitable
biomarker antigen targets for treatment in late-stage
lung cancer. Previous research on the salvage pathway
enzyme TK1 shows a unique relationship with
cancer patients as serum levels are raised according to
cancer grade. To expand this analysis, the other salvage pathway
enzymes were evaluated for possible upregulation within
lung cancer.
Adenine phosphoribosyltransferase,
deoxycytidine kinase, and
hypoxanthine guanine phosphoribosyltransferase (
HPRT) were assessed for their presentation on two
non-small-cell lung cancer cell lines NCI-H460 and A549. In the present study, we show that
deoxycytidine kinase and
adenine phosphoribosyltransferase have no significant relationship with the membrane of NCI-H460 cells. However, we found significant localization of
HPRT to the membrane of NCI-H460 and A549 cells. When treated with anti-
HPRT antibodies, the average fluorescence of the cell population increased by 24.3% and 12.9% in NCI-H460 and A549 cells, respectively, in comparison with controls. To ensure that expression was not attributed to cytoplasmic
HPRT, confocal microscopy was performed to visualize
HPRT binding on the plasma membrane. After staining NCI-H460 cells treated with both fluorescent
antibodies and a membrane-specific
dye, we observed direct overlap between
HPRT and the membrane of the
cancer cells. Additionally,
gold-conjugated
antibodies were used to label and quantify the amount of
HPRT on the cell surface using scanning electron microscopy and energy-dispersive analysis X-ray. Further confirming
HPRT presence, the
gold weight percentage of the sample increased significantly when NCI-H460 cells were exposed to
HPRT antibody (P=0.012) in comparison with isotype controls. Our results show that
HPRT is localized on the surface of these
non-small-cell lung cancer cell lines.