A novel bioinformatic approach reveals cooperation between Cancer/Testis genes in basal-like breast tumors

Archive ouverte

Laisné, Marthe | Rodgers, Brianna | Benlamara, Sarah | Wicinski, Julien | Nicolas, André | Djerroudi, Lounes | Gupta, Nikhil | Ferry, Laure | Kirsh, Olivier | Daher, Diana | Philippe, Claude | Okada, Yuki | Charafe-Jauffret, Emmanuelle | Cristofari, Gael | Meseure, Didier | Vincent-Salomon, Anne | Ginestier, Christophe | Defossez, Pierre-Antoine

Edité par CCSD ; Nature Publishing Group [1987-....] -

International audience. Breast cancer is the most prevalent type of cancer in women worldwide. Within breast tumors, the basal-like subtype has the worst prognosis, prompting the need for new tools to understand, detect, and treat these tumors. Certain germline-restricted genes show aberrant expression in tumors and are known as Cancer/Testis genes; their misexpression has diagnostic and therapeutic applications. Here we designed a new bioinformatic approach to examine Cancer/Testis gene misexpression in breast tumors. We identify several new markers in Luminal and HER-2 positive tumors, some of which predict response to chemotherapy. We then use machine learning to identify the two Cancer/Testis genes most associated with basal-like breast tumors: HORMAD1 and CT83. We show that these genes are expressed by tumor cells and not by the microenvironment, and that they are not expressed by normal breast progenitors; in other words, their activation occurs de novo. We find these genes are epigenetically repressed by DNA methylation, and that their activation upon DNA demethylation is irreversible, providing a memory of past epigenetic disturbances. Simultaneous expression of both genes in breast cells in vitro has a synergistic effect that increases stemness and activates a transcriptional profile also observed in double-positive tumors. Therefore, we reveal a functional cooperation between Cancer/Testis genes in basal breast tumors; these findings have consequences for the understanding, diagnosis, and therapy of the breast tumors with the worst outcomes.

Suggestions

Du même auteur

Non-canonical functions of UHRF1 maintain DNA methylation homeostasis in cancer cells

Archive ouverte | Yamaguchi, Kosuke | CCSD

International audience. Abstract DNA methylation is an essential epigenetic chromatin modification, and its maintenance in mammals requires the protein UHRF1. It is yet unclear if UHRF1 functions solely by stimulati...

Genetic screens reveal mechanisms for the transcriptional regulation of tissue-specific genes in normal cells and tumors

Archive ouverte | Naciri, Ikrame | CCSD

International audience. The proper tissue-specific regulation of gene expression is essential for development and homeostasis in metazoans. However, the illegitimate expression of normally tissue-restricted genes-li...

A genetic screen identifies BEND3 as a regulator of bivalent gene expression and global DNA methylation

Archive ouverte | Yakhou, Lounis | CCSD

International audience. Epigenetic mechanisms are essential to establish and safeguard cellular identities in mammals. They dynamically regulate the expression of genes, transposable elements and higher-order chroma...

Chargement des enrichissements...