Experience in the use of sunitinib given as a single agent in metastatic chemoresistant and castration-resistant prostate cancer patients

Revisiting prostate cancer metabolism: From metabolites to disease and therapy

Prostate cancer (PCa), one of the most commonly diagnosed cancers worldwide, still presents important unmet clinical needs concerning treatment. In the last years, the metabolic reprogramming and the specificities of tumor cells emerged as an exciting field for cancer therapy. The unique features of PCa cells metabolism, and the activation of specific metabolic pathways, propelled the use of metabolic inhibitors for treatment. The present work revises the knowledge of PCa metabolism and the metabolic alterations that underlie the development and progression of the disease. A focus is given to the role of bioenergetic sources, namely, glucose, lipids, and glutamine sustaining PCa cell survival and growth. Moreover, it is described as the action of oncogenes/tumor suppressors and sex steroid hormones in the metabolic reprogramming of PCa. Finally, the status of PCa treatment based on the inhibition of metabolic pathways is presented. Globally, this review updates the landscape of PCa metabolism, highlighting the critical metabolic alterations that could have a clinical and therapeutic interest.

Differential sensitivity of prostate tumor derived endothelial cells to sorafenib and sunitinib

Background

Prostate cancer is the second leading cause of male cancer death in developed countries. Although the role of angiogenesis in its progression is well established, the efficacy of anti-angiogenic therapy is not clearly proved. Whether this could depend on differential responses between tumor and normal endothelial cells has not been tested.

Methods

We isolated and characterized three lines of endothelial cells from prostate cancer and we tested the effect of Sunitinib and Sorafenib, and the combined treatment with the anti-androgen Casodex, on their angiogenic functions.

Results

Endothelial cells isolated from prostate tumors showed angiogenic properties and expression of androgen and vascular endothelial cell growth factor receptors. Sunitinib affected their proliferation, survival and motility while Sorafenib only showed a minor effect. At variance, Sunitinib and Sorafenib showed similar cytotoxic and anti-angiogenic effects on normal endothelial cells. Sorafenib and Sunitinib inhibited vascular endothelial cell growth factor receptor2 phosphorylation of prostate cancer endothelial cells, while they differentially modulated Akt phosphorylation as no inhibitory effect of Sorafenib was observed on Akt activation. The combined treatment of Casodex reverted the observed resistance to Sorafenib both on cell viability and on Akt activation, whereas it did not modify the response to Sunitinib.

Conclusions

Our study demonstrates a resistant behavior of endothelial cells isolated from prostate cancer to Sorafenib, but not Sunitinib. Moreover, it shows the benefit of a multi-target therapy combining anti-angiogenic and anti-hormonal drugs to overcome resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-939) contains supplementary material, which is available to authorized users.

Skeletal metastasis: treatments, mouse models, and the Wnt signaling

Skeletal metastases result in significant morbidity and mortality. This is particularly true of cancers with a strong predilection for the bone, such as breast, prostate, and lung cancers. There is currently no reliable cure for skeletal metastasis, and palliative therapy options are limited. The Wnt signaling pathway has been found to play an integral role in the process of skeletal metastasis and may be an important clinical target. Several experimental models of skeletal metastasis have been used to find new biomarkers and test new treatments. In this review, we discuss pathologic process of bone metastasis, the roles of the Wnt signaling, and the available experimental models and treatments.

Progress of molecular targeted therapies for prostate cancers

Prostate cancer remains the most commonly diagnosed malignancy and the second leading cause of cancer-related deaths in men in the United States. The current standard of care consists of prostatectomy and radiation therapy, which may often be supplemented with hormonal therapies. Recurrence is common, and many develop metastatic prostate cancer for which chemotherapy is only moderately effective. It is clear that novel therapies are needed for the treatment of the malignant forms of prostate cancer that recur after initial therapies, such as hormone refractory (HRPC) or castration resistant prostate cancer (CRPC). With advances in understanding of the molecular mechanisms of cancer, we have witnessed unprecedented progress in developing new forms of targeted therapy. Several targeted therapeutic agents have been developed and clinically used for the treatment of solid tumors such as breast cancer, non-small cell lung cancer, and renal cancer. Some of these reagents modulate growth factors and/or their receptors, which are abundant in cancer cells. Other reagents target the downstream signal transduction, survival pathways, and angiogenesis pathways that are abnormally activated in transformed cells or metastatic tumors. We will review current developments in this field, focusing specifically on treatments that can be applied to prostate cancers. Finally we will describe aspects of the future direction of the field with respect to discovering biomarkers to aid in identifying responsive prostate cancer patients.