Ki-67 and PCNA expression in prostate cancer and benign prostatic hyperplasia

Clin Invest Med. 2008;31(1):E8-E15. doi: 10.25011/cim.v31i1.3136.


Objective: Ki-67 is a proliferation-associated nuclear antigen and is expressed in all cycling cells except for resting cells in the G0-phase. PCNA is an acidic nuclear protein and has been recognized as a histologic marker for the G1/S phase in the cell cycle. Ki-67and PCNA labeling indices are considered to reflect cell proliferation, particularly, growth fraction. The purpose of this study is to investigate the expression levels of Ki-67 and PCNA in prostate cancer (PCa) and benign prostatic hyperplasia (BPH) and their potential on the early diagnosis of PCa.

Methods: Human prostate cancer cell lines LNCaP and PC-3, human normal prostate epithelial cell line HuPEC, tissues from patients with PCa (121 cases) and BPH (45) and 36 normal cases were examined for the expression of Ki-67 and PCNA by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Then, the association of Ki-67 and PCNA expression with clinical grading of PCa was analyzed by immunohistochemistry staining.

Results: The ratios of PCNA and Ki-67 expression levels in LNCaP and PC-3 were higher (P < 0.05, P < 0.001) than that in HuPEC. The two markers were differentially expressed in three tissues and showed increased expression in PCa (P < 0.05) and BPH (P < 0.05), relative to human normal prostate tissues. Compared with BPH, the ratio of Ki-67 and PCNA expressed in tumour tissue was increased (P < 0.05). The increase of Ki-67 was greater than that of PCNA. Expression of the two markers increased after different grading of PCa cases. The values of Ki-67/PCNA were: 0.073 in grade I PCa tissues, 0.119 in grade IIa PCa tissues, 0.141 in grade IIa PCa tissues, 0.234 in grade III PCa tissues.

Conclusion: The combination of Ki-67 and PCNA, specific proliferative markers of PCa, may improve the accuracy of early diagnosis of prostatic cancer.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers, Tumor / biosynthesis*
  • Biomarkers, Tumor / genetics
  • Cell Line, Tumor
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Ki-67 Antigen / biosynthesis*
  • Ki-67 Antigen / genetics
  • Male
  • Proliferating Cell Nuclear Antigen / biosynthesis*
  • Proliferating Cell Nuclear Antigen / genetics
  • Prostatic Hyperplasia / diagnosis
  • Prostatic Hyperplasia / genetics
  • Prostatic Hyperplasia / metabolism*
  • Prostatic Neoplasms / diagnosis
  • Prostatic Neoplasms / genetics
  • Prostatic Neoplasms / metabolism*
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • RNA, Neoplasm / biosynthesis
  • RNA, Neoplasm / genetics
  • Reverse Transcriptase Polymerase Chain Reaction


  • Biomarkers, Tumor
  • Ki-67 Antigen
  • Proliferating Cell Nuclear Antigen
  • RNA, Messenger
  • RNA, Neoplasm