The nanoparticle has been designed to locate primary and hidden metastatic tumours and deliver the suppressor gene, which is known to play a key role in the pathogenesis of tumours.
Developments in the trial were presented at an American Association of Anatomists (AAA) scientific session by Esther Chang, who developed the nanoparticle with he colleagues at Georgetown University Medical Center's Lombardi Cancer Center.
The nanoparticle is essentially a fat droplet that envelops the p53 suppressor gene, with a tumour targeting antibody attached. Once the nanoparticle has reached a tumour the gene is delivered and the fat droplet biodegrades.
Currently there are six patients with a variety of cancers enrolled in the trial but this number is expected to rise to 14. Chang reported that early results from the trial are promising, with anti-tumour efficacy being demonstrated and safety data accumulated.
Promising preclinical trials
Extensive research has been undertaken into the role p53 plays in the formation of tumours, which has been built upon by preclinical trials investigating the effectiveness of the suppressor gene.
Chang’s research group used animal models to test the effectiveness of p53 against 16 different types of tumour, including prostate, pancreatic, melanoma, breast and head and neck cancer.
The gene was used in conjunction with conventional cancer therapy and “dramatically improved the efficacy”. By improving the effectiveness of the treatment the researchers believe that lower doses could be administered, which reduces side effects.
The role of p53
Normally functioning cells have two copies of the p53 gene, which produces a protein that can coordinate cell repair or induce cell death.
When p53 stops functioning normally malignant cell growth can occur and the gene’s malfunction has also been linked to the resistance of some tumours to chemotherapy and radiotherapy.