The epithelial type of ovarian cancer is a lethal disease with an overall survival rate of less than 70% five years after diagnosis. High grade serous ovarian carcinomas is the most common type. Although highly responsive to chemotherapy following surgery, relapse and the eventual failure of treatment is very common. Currently there are no screening programs for the detection of ovarian cancer. The disease is often diagnosed at late stage when there has been extensive spread within the peritoneal cavity. These factors have contributed to the poor overall survival.The etiology is unknown. However, up to 15% of all cases of high grade serous ovarian carcinomas occur in women who have inherited a mutation in either of the BRCA1 or BRCA2 cancer susceptibility genes, that also predispose to breast cancer. Although new hereditary factors have been discovered, their role in ovarian cancer is unknown. Thus the etiology for the majority of high grade serous ovarian carcinomas is unknown.

I study the role of hereditary and somatic genetic factors in high grade serous ovarian carcinomas. Research programs involve the characterization of genes in the germline of women with the hereditary form of ovarian cancer or in cancer specimens. The study of genetic events has improved our understanding of the biology ovarian cancer as well as provided biomarkers for clinical management. A successful example of this approach has been the contribution to the discoveries BRCA1 and BRCA2, and their application (genetic testing) to the health care management of women at high risk for inherited predisposition to breast and ovarian cancers.

Major themes of study include the following areas of research:

  1. Investigating the contribution of known cancer susceptibility genes, such as BRCA1 and BRCA2, in hereditary cancer families that feature ovarian and breast cancers, particularly in the French Canadian population of Quebec.

  2. Investigating the significance of specific somatic molecular genetic events occurring in ovarian cancer cells using various established techniques (mutation screening, loss of heterozygosity analyses, gene expression microarray analyses) and high throughput genotyping technologies (whole genome SNP array, exome sequencing) available through the McGill University and Genome Quebec Innovation Centre.

  3. Molecular genetic characterization of a uniquely developed ovarian cancer cell line model which was rendered non-tumorigenic as a consequence of transfer or normal genes in order to identify molecular pathways important in high grade serous ovarian carcinomas.

 

Understanding ovarian cancer biology through the study of

hereditary and somatic cell genetics

Patricia N. Tonin, PhD


Associate Professor,

Departments of Medicine & Human Genetics, McGill University


Scientist,

Department of Medical Genetics, McGill University Health Centre


Cancer Axis Co-Leader,

The Research Institute of the McGill University Health Centre

Mailing Address

Medical Genetics (L10-132)

Montreal General Hospital

1650 Cedar Avenue

Montreal, Quebec, Canada

H3A 1A4

patricia.tonin@mcgill.ca

Contributions

  1. Identification of the BRCA1 and BRCA2 breast and ovarian cancer susceptibility genes

  2. Specific BRCA1 and BRCA2 mutations recur in Quebec French Canadian cancer families

  3. Developed a unique genetically modified ovarian cancer cell line model for characterizing pathways implicated in ovarian cancer

  4. Identified genomic signatures enriched in TP53 mutation-positive ovarian cancers harboring in missense versus null p53 mutations