Elisabeth Bloemena - research

Polycomb genes in differentiation patterns of silavary gland tumors

Polycomb (PcG) genes encode proteins that form DNA-binding complexes which suppress the transcription of genes, amongst which the Hox genes. By this, PcG proteins are important in development and maintenance of cell identity. During embryogenesis, PcG proteins are amongst the key regulators of proper spatial development of the embryo. More recently it has become clear that these proteins are also involved in the differentiation of haematopoietic cells throughout life. The expression of PcG proteins in adult human tissues is tightly regulated leading to different expression of PcG proteins in various tissues. At present, no data are available on the expression of these gene products in human salivary glands and salivary gland tumors. This project aims at identifying PcG protein expression patterns in normal salivary glands and salivary gland tumors.
adenoid cystic carcinoma
adenoid cystic carcinoma
Whartin tumor
Whartin tumor
mucoepidermoid carcinoma
mucoepidermoid carcinoma

Genomic profiling of salivary gland tumors

Tumourigenesis is a multistep process in which frequently structural abnormalities in the genome of the cells are observed leading to disruption of biological processes, e.g. loss of control of proliferation, and ultimately malignant transformation. In the last decade important progress has been made in the unravelling of the human genome and the availability of techniques to investigate chromosome- and genome wide alterations in tumour cells. High throughput tumour profiling at a whole genome scale can be performed by either micro-array based expression profiling, or by micro-array comparative genomic hybridisation (CGH), which provides information on DNA copy number changes.
This project aims at defining, by microarray CGH, DNA profiles of benign and malignant salivary gland tumors and investigates the use of this technique to predict the clinical course.
BMI 1 expression in adenoid cystic carcinoma
BMI 1 expressie in adenoid cytic carcinoma

Epstein Barr virus (EBV) in gastric cancer

In 7.2% of Dutch gastric adenocarcinomas nos (GC) Epstein Barr virus (EBV) is clonally present in the tumor cells. In this project we demonstrated, in a large cohort of Dutch GC cases (n=566) that EBV positive GC have less lymph node metastases than EBV negative GC and hence have a better disease free survival. In the EBV positive GC a more extensive lymfoid infiltrate is present compared to EBV negative GC, containing more T lymphocytes with an activated cytotoxic phenotype. Therefore, we hypothesize that in EBV positive GC an immune response is present, probably against an EBV associated protein which is capable of eradicating micrometastases.
This project aims at identifying the EBV protein responsible for the immune stimulation.
EBV positive gastric carcinoma
EBV positive gastric carcinoma

LMP1 and LMP2 specific T-cell stimulation and immunotherapy in EBV+ Hodgkin's disease

In 40-90% of Hodgkin's disease (HD) EBV is clonally present in the tumor cells. The EBV proteins EBNA1, LMP1 and LMP2 are expressed by the tumor. Despite a large lymfoid infiltrate and the presence of foreign proteins, the tumor is not eradicated by the immune system. In healthy EBV carriers only very weak T cell responses against LMP1 and 2 can be detected in a low percentage of donors.
This project aims at augmenting the immune response against immuno subdominant, tumor related EBV proteins by using dendritic cells as specialised antigen presenting cells.
microscoop