Parathyroid Tumorigenesis - A Role For The Newly Identified Putative Tumour Suppressor HRPT2
Funder
National Health and Medical Research Council
Funding Amount
$432,750.00
Summary
Primary hyperparathyroidism is one of the most common tumour associated diseases of hormone secreting glands affecting 0.1-0.5% of adults and up to 3.4% of post-menopausal women. It can occur in family members, either alone or with other tumours, and can also occur with no family history (sporadic). Hyperparathyroidism is caused by secretion of excessive levels of parathyroid hormone. Amongst other problems, this causes significant bone disease that can lead to fracture. What is going wrong at t ....Primary hyperparathyroidism is one of the most common tumour associated diseases of hormone secreting glands affecting 0.1-0.5% of adults and up to 3.4% of post-menopausal women. It can occur in family members, either alone or with other tumours, and can also occur with no family history (sporadic). Hyperparathyroidism is caused by secretion of excessive levels of parathyroid hormone. Amongst other problems, this causes significant bone disease that can lead to fracture. What is going wrong at the genetic level to cause this disease is, in most cases, poorly understood. In Hyperparathyroidism Jaw Tumour Syndrome (HPT-JT), one form of familial hyperparathyroidism, we and our international collaborators have recently identified mutations in the gene HRPT2 predicted to lead to loss of function of this gene. HRPT2 has no known similarities to other genes that may give hints as to its function. The overall aim of this project is to test our theory that HRPT2 has an important role in abnormal growth of parathyroid tissue that, in some cases, will lead to cancer. Further, we hypothesise that this gene will have a role in both familial and sporadic presentations of parathyroid disease. We will investigate this gene in parathyroid tumour specimens from patients with familial and sporadic disease for gene mutations and also different levels of gene expression. We will also explore a mechanism for how these mutations may function to cause disease and look at the effect of reduced HRPT2 expression on expression of thousands of other genes using a technique known as microarray analysis. The expected outcomes of this study include the identification of individuals at risk of developing cancer whose treatment will be tailored to their genetic profile. Characterisation of HRPT2, and the genes its expression influence, may lead to the identification of suitable targets for future treatment of hyperparathyroidism and its effects on bone disease.Read moreRead less
The Identification Of Novel Genes Involved In The Initiation And Development Of Thyroid Neoplasia
Funder
National Health and Medical Research Council
Funding Amount
$227,545.00
Summary
Thyroid cancer is the most frequently diagnosed endocrine malignancy, comprising 1% of all human malignancy. However, its actual occurrence indicated by autopsy studies may be as high as 10%. To date, a number of genes, both oncogenes (genes that are inappropriately switched on and take part in the process of tumour development) and tumour suppressor genes (genes that are switched off and lose their protective role against tumour development), have been implicated in the development of thyroid c ....Thyroid cancer is the most frequently diagnosed endocrine malignancy, comprising 1% of all human malignancy. However, its actual occurrence indicated by autopsy studies may be as high as 10%. To date, a number of genes, both oncogenes (genes that are inappropriately switched on and take part in the process of tumour development) and tumour suppressor genes (genes that are switched off and lose their protective role against tumour development), have been implicated in the development of thyroid cancer. However mutations, mistakes in the genetic code, of these genes account for only a small percentage of thyroid tumours and none of these genes have been shown to be useful as clear prognostic markers for tumour progression or aggressiveness. The merging of the 2 fields of cytogenetics (the study of chromosomes) and molecular genetics (the study of genes at the DNA and RNA level) has strengthened our ability to understand the process of tumour development. We are proposing use of a technique called Comparative Genomic Hybridisation to aid in the identification of new genes associated with tumour development in both benign and malignant thyroid disease. This technique has already been used to aid in the location of genes with a role in ovarian and brain cancer and in some familial syndromes characterised by breast and gastrointestinal malignancies. This method involves the detection of regions of chromosomal amplifications or deletions in tumour DNA that is fluorescently labelled (green), mixed with normal human DNA also fluorescently labelled (red). If the tumour contains regions of amplification (likely housing an oncogene), analyses show increased green fluorescence and if deletions are present (likely housing a tumour suppressor gene), analyses show increased red fluorescence. Chromosomal regions identified by this method will be further analysed to identify the precise genes they contain and establish a role for these genes in the development of thyroid tumours.Read moreRead less