Related Experiment Video
Updated: Jun 2, 2026
Detection and Isolation of Cancer in Prostate Biopsies Using Stimulated Raman Histology and Artificial Intelligence
Published on: June 10, 2025
Detection of RB, p16/CDKN2 and p15(INK4B) gene alterations with immunohistochemical studies in human prostate
N Konishi1, Y Hiasa, T Tsuzuki
1MIE UNIV,FAC MED,DEPT PATHOL,TSU,MIE 514,JAPAN. CHIBA UNIV,SCH MED,DEPT UROL,CHUO KU,CHIBA 260,JAPAN. CTR DIS CONTROL,DIV HIV AIDS,HEMATOL DIS BRANCH,ATLANTA,GA 30333.
Abstract:
To examine the status of cell cycle-inhibitory genes in human prostate carcinoma, we investigated alterations of RE (retinoblastoma), p16/CDKN2 and p15(INK4B) genes in 32 adenocarcinomas with immunohistochemistry. PCR-single-strand conformation polymorphism (SSCP) was used to examine all 27 exons of the RE gene, exons 1 to 3 of the p16/CDKN2 gene and exons 1 and 2 of the p15(INK4B) gene for mutations. Loss of heterozygosity (LOH) for the RE gene was probed by restriction fragment length polymorphism (RFLP) analysis. In addition, coordinate samples were subjected to immunohistochemical studies for reactivity to RE and p16 protein. The RE gene alterations were detected in 5 of the 32 tumors (16%); of these, only one mutation, a missense substitution, occurred within an exon. The remaining four single base insertions or deletions were found within introns of the RE gene and no mutational event was detected in its promoter region. LOH involving intron 17 of RB was detected in three cases of 10 informative tumors (30%). Intragenic mutations were also present in 3 of the 32 tumors in the p16/CDKN2 gene. In contrast, no mutational events were found in the p15(INK4B) gene in the tumors. Only one tumor had both a p16/CDKN2 mutation and LOH of the RE gene. Expression of pRB was absent or reduced in 16 cancers, while p16 expression was present in all cases to varying degrees. The results suggest that p16/CDKN2 gene mutations occur rarely and intragenic mutation, but not LOH,of the RE gene is not required in prostatic tumorigenesis.
Insights
Investigating cell cycle genes in prostate cancer revealed rare p16/CDKN2 mutations and infrequent RB gene alterations. Intragenic RB mutations, not LOH, are not required for prostate tumorigenesis.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Prostate carcinoma is a significant health concern.
- Cell cycle regulation is crucial in cancer development.
- Alterations in cell cycle-inhibitory genes are implicated in tumorigenesis.
Purpose of the Study:
- To investigate alterations in retinoblastoma (RB), p16/CDKN2, and p15(INK4B) genes in human prostate carcinoma.
- To determine the role of these genes in prostate cancer development.
Main Methods:
- Analysis of 32 prostate adenocarcinomas.
- PCR-single-strand conformation polymorphism (SSCP) for mutation detection.
- Restriction fragment length polymorphism (RFLP) for loss of heterozygosity (LOH) analysis.
- Immunohistochemistry for RB and p16 protein expression.
Main Results:
- RB gene alterations detected in 16% of tumors, primarily intronic mutations.
- Loss of heterozygosity (LOH) for RB found in 30% of informative cases.
- Intragenic mutations in p16/CDKN2 observed in 3 tumors; no mutations in p15(INK4B).
- Reduced or absent pRB expression in 16 cancers; p16 expression present in all.
Conclusions:
- p16/CDKN2 gene mutations are rare in prostate carcinoma.
- Intragenic RB mutations, not LOH, are not essential for prostate tumorigenesis.
- The study clarifies the status of key cell cycle-inhibitory genes in prostate cancer.
