Related Experiment Videos
[Analysis of p53 gene in gynecologic tumors]
Y Yaginuma1, T Yamashita, J C Duenas
1Department of Obstetrics & Gynecology, Asahikawa Medical College.
Abstract:
The inactivation of the tumor suppressor gene p53 has been demonstrated in a variety of human tumors. Herein, we performed a p53 gene analysis of human gynecologic tumor cell lines and tumor tissues. In the SK-OV-3 cell line, Southern analysis suggested the presence of sequence deletions/rearrangements in at least one allele of p53 gene. Transcripts were not detectable by either Northern or PCR analysis. Sequencing analysis of the entire coding region revealed mutations changing the p53 amino acid composition in all six endometrial carcinoma cell lines tested (Ishikawa, Hec1-A, Hec1-B, KLE, RL95-2, and AN-3), and four cell lines in ovarian carcinoma cell lines (Caov-3, -4, OVCAR-3, and Kuramochi). Of the seven cervical carcinoma cell lines, two (HT-3 and C-33A) contained p53 codon changes. We were unable to detect the human papilloma virus (HPV) in these two cell lines. By contrast, five HPV-positive cervical carcinoma cell lines (HeLa S-3, Caski, SiHa, C-41, and ME-180) contained wild-type p53 gene sequences. Examination of loss of heterozygosity (LOH) by PCR revealed that about 30% of the human ovarian carcinoma tissues has LOH at the locus of p53 gene. We suggest that, in the HPV-positive cervical tumors, p53 inactivation occurred via the known mechanism of viral E6/cellular p53 protein association, whereas in all other tumors (ovarian carcinoma, endometrial carcinoma, HPV-negative cervical carcinoma) p53 function was compromised by changes in the amino acid sequence.
Insights
Tumor suppressor gene p53 inactivation occurs through mutations in endometrial and ovarian cancers. Human papillomavirus (HPV)-negative cervical cancers show p53 gene mutations, while HPV-positive types utilize viral proteins for p53 inactivation.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Context:
- The tumor suppressor gene p53 plays a crucial role in preventing cancer development.
- p53 gene inactivation is a common event in various human malignancies.
- Understanding p53 alterations in gynecologic tumors is vital for targeted therapies.
Purpose:
- To investigate p53 gene alterations in human gynecologic tumor cell lines and tissues.
- To differentiate mechanisms of p53 inactivation in HPV-positive versus HPV-negative cervical cancers.
- To analyze p53 gene status in endometrial and ovarian carcinomas.
Summary:
- p53 gene analysis in gynecologic tumors revealed sequence deletions/rearrangements in SK-OV-3 cells.
- Mutations altering p53 amino acid composition were found in all tested endometrial and several ovarian carcinoma cell lines.
- HPV-negative cervical cancer cell lines (HT-3, C-33A) had p53 codon changes, unlike HPV-positive lines with wild-type p53.
- Loss of heterozygosity (LOH) at the p53 locus was observed in approximately 30% of ovarian carcinoma tissues.
Impact:
- p53 inactivation mechanisms vary by tumor type: HPV E6/p53 association in HPV-positive cervical cancers.
- Mutations compromising p53 function are prevalent in ovarian, endometrial, and HPV-negative cervical cancers.
- Findings highlight distinct pathways of p53 dysregulation in gynecologic malignancies, informing therapeutic strategies.