Metastatic prolactinoma: case report with immunohistochemical assessment for p53 and Ki-67 antigens

A novel use of temozolomide in a patient with malignant prolactinoma

We report a 64-year-old male who presented to our department in 2007 with bitemporal hemianopia secondary to a large recurrent pituitary prolactinoma in the sellar region and metastatic deposits elsewhere in his neuraxis. He underwent a transphenoidal excision of the large pituitary adenoma which was uncomplicated, although he did suffer from diabetes insipidus post-operatively. He had initially been diagnosed with prolactinoma some years before and had undergone multiple craniotomies to debulk recurrent metastatic lesions. As the patient had already undergone radiotherapy in the past, a novel approach to adjuvant therapy was necessary and he was started on a course of oral chemotherapy, temozolomide, with good results.

Identification of genes differentially expressed between benign and osteopontin transformed rat mammary epithelial cells

Background

Osteopontin is a secreted, integrin-binding and phosphorylated acidic glycoprotein which has an important role in tumor progression.

Findings

In this study, we have utilized suppressive subtractive hybridization (SSH) to evaluate OPN regulated gene expression, using the Rama 37 benign non-invasive rat mammary cell line and a subclone, Rama 37-OPN. Rama 37-OPN was produced by stably transfecting Rama 37 with an OPN expression vector and it demonstrates increased malignant properties in vitro. Sequence and expression array analysis of the respective cDNA libraries of over 1600 subtracted cDNA fragments revealed 982 ESTs, 45 novel sequences and 659 known genes. The known up-regulated genes in the Rama 37-OPN library code for proteins with a variety of functions including those involved in metabolism, cell adhesion and migration, signal transduction and in apoptosis. Four of the most differentially expressed genes between the benign and in vitro malignant rat mammary cell lines are tumor protein translationally controlled I (TPTI), aryl hydrocarbon receptor nuclear translocator (ARNT), ataxia telangiectasia mutated (ATM) and RAN GTPase (RAN). The largest difference (ca 10,000 fold) between the less aggressively (MCF-7, ZR-75) and more aggressively malignant (MDA MB 231, MDA MB 435S) human breast cancer cell lines is that due to RAN, the next is that due to osteopontin itself.

Conclusion

The results suggest that enhanced properties associated with the malignant state in vitro induced by osteopontin may be due to, in part, overexpression of RAN GTPase and these biological results are the subject of a subsequent publication [1].