Apolipoprotein M (ApoM) and the
vitamin D receptor (VDR) are
apolipoproteins predominantly presenting in
high-density lipoprotein (HDL) and a karyophilic
protein belonging to the steroid‑thyroid receptor superfamily, respectively. Previous studies have demonstrated that ApoM and VDR are associated with
cholesterol metabolism, immune and
colorectal cancer regulation. In order to investigate whether ApoM affected the expression of VDR in
colorectal cancer cells, a single‑tube duplex fluorescence reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) system was developed to simultaneously detect the
mRNA levels of VDR and GAPDH in HT‑29 cells overexpressing ApoM. The results demonstrated that the amplification products were confirmed as the specific fragment of VDR/GAPDH using the
DNA sequencing instrument. The sensitivity, linear range, correlation coefficient, amplification efficiency, intra‑assay and inter‑assay coefficients of variation were 40 copies/µl, 4.00x101‑4.00x105 copies/µl, 0.999, 92.42%, 0.09‑0.34% and 0.32‑0.65% for VDR, and 40 copies/µl, 4.00x101‑4.00x105 copies/µl, 0.999, 98.07%, 0.19‑0.43% and 0.40‑0.75% for GAPDH, respectively. The results indicated that the expression of VDR
mRNA was significantly higher in HT‑29 cells overexpressing ApoM, compared with the negative control group (P<0.05). In conclusion, the current study successfully developed the single‑tube duplex RT‑qPCR to simultaneously detect VDR and GAPDH expression in
colorectal cancer cells. The methodology results demonstrated that the duplex RT‑qPCR system with high sensitivity and specificity could ensure the objectivity and credibility of the detection. The present study confirmed that ApoM significantly increased the expression of VDR in HT‑29 cells. In addition, it was hypothesized that ApoM may be involved in
antineoplastic activity via the upregulation of VDR expression, which may provide novel directions for the investigation of ApoM in
cancer.