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Updated: Aug 20, 2026
miRNA Expression Analyses in Prostate Cancer Clinical Tissues
Published on: September 8, 2015
Relative concentrations of hK2/PSA mRNA in benign and malignant prostatic tissue
Susanna Lintula1, Jakob Stenman, Anders Bjartell
1Department of Clinical Chemistry, Helsinki University Central Hospital, Helsinki, Finland. susanna.lintula@hus.fi
Background:
Prostate-specific antigen (PSA/KLK3) and human kallikrein 2 (hK2/KLK2) belong to the human kallikrein gene family. These two highly homologous genes are specifically expressed in the prostate under androgen control. Expression of these is regulated by similar mechanisms but changes in their relative expression have been observed in prostate cancer.
Methods:
We determined the relative levels of PSA and hK2 mRNA in benign and malignant prostate tissue using a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method. The mRNA of PSA and hK2 are reverse transcribed and amplified in one reaction with the same primers.
Results:
The variation in the ratio of hK2/PSA mRNA was remarkably small, the difference between the highest and lowest values being three-fold. The ratio was significantly higher in WHO grade 2 compared to normal or benign prostatic hyperplasia tissue (P = 0.032 and P = 0.035, respectively) and in grade 3 compared to normal or benign prostatic hyperplasia tissue (P = 0.006 in both).
Conclusions:
The new quantitative RT-PCR technique facilitates very accurate quantitation of the relative mRNA levels of homologous genes. Using this method we have shown that the ratio of hK2/PSA mRNA is higher in cancerous than in benign prostatic tissue.
Insights
The ratio of human kallikrein 2 (hK2) mRNA to prostate-specific antigen (PSA) mRNA is higher in cancerous prostate tissue than in benign tissue. This finding utilizes a novel quantitative reverse transcription-polymerase chain reaction (RT-PCR) method.
Area of Science:
- Molecular Biology
- Genetics
- Oncology
Background:
- Prostate-specific antigen (PSA/KLK3) and human kallikrein 2 (hK2/KLK2) are homologous genes within the human kallikrein gene family.
- Both genes are prostate-specific and androgen-controlled, with similar regulatory mechanisms.
- Altered relative expression of PSA and hK2 has been noted in prostate cancer.
Purpose of the Study:
- To quantify the relative mRNA levels of PSA and hK2 in benign and malignant prostate tissues.
- To investigate changes in the hK2/PSA mRNA ratio in relation to prostate cancer.
- To evaluate a novel quantitative reverse transcription-polymerase chain reaction (RT-PCR) method for analyzing homologous gene expression.
Main Methods:
- Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was employed to determine relative PSA and hK2 mRNA levels.
- A single-step RT-PCR reaction was used for simultaneous reverse transcription and amplification of both PSA and hK2 mRNA.
- The hK2/PSA mRNA ratio was calculated for benign and malignant prostate tissue samples.
Main Results:
- The hK2/PSA mRNA ratio exhibited minimal variation across samples, with a three-fold difference between the highest and lowest values.
- A statistically significant increase in the hK2/PSA mRNA ratio was observed in WHO grade 2 prostate cancer compared to normal or benign prostatic hyperplasia (BPH) tissue (P = 0.032 and P = 0.035).
- Similarly, WHO grade 3 prostate cancer showed a significantly higher hK2/PSA mRNA ratio compared to normal or BPH tissue (P = 0.006 for both).
Conclusions:
- The developed quantitative RT-PCR technique enables precise measurement of relative mRNA levels for homologous genes.
- The study demonstrates that the hK2/PSA mRNA ratio is elevated in cancerous prostate tissue compared to benign prostatic tissue.
- This finding suggests that the hK2/PSA mRNA ratio could serve as a potential biomarker in prostate cancer diagnostics.
