Current Pharmaceutical Biotechnology - Volume 12, Issue 11, 2011

Matrix metalloproteinases (MMPs) have been implicated in both normal and pathologic processes. In cancer in particular, in vitro and animal studies showed an involvement of MMPs in many stages of cancer progression. This led to the development of MMP inhibitors that in most cases failed in clinical trials. In this review we go over the role of MMPs in the different stages of cancer progression and try to understand why the early generation of MMP inhibitors failed. The analysis of the lessons from this first experience, plus the review of the current knowledge that shows that MMPs may be pro-or anti-tumorigenic may set the stage for a future success for this therapeutic strategy in cancer.

Tumor metastasis is a main contributor to death in cancer patients. In the last years, a new class of molecules that reduces the metastatic propensity has been identified: metastasis suppressors. These proteins regulate multiple steps in the metastatic cascade, including cell invasion, survival in the vascular and lymphatic circulation, and colonization of distant organ sites. As a consequence, they are very important therapeutic targets. This review discusses our current understanding of metastasis suppressors and how this knowledge might be useful to improve the treatment of cancer patients.

In the last years, PKC has become an attractive target for the treatment of cancer patients given its widely described role in carcinogenesis and tumor promotion. Despite the extensive research conducted on these phorbol ester receptors there is only limited knowledge about the contribution of each individual PKC isozyme in malignant transformation, mainly due to the different roles of each isozyme and their tissue-specificity. This diversity provides the unique opportunity to develop specific pharmacological agents, but the complex nature of the signaling pathways activated by different PKCs challenges selective drug therapies. Currently, several classes of PKC inhibitors including small molecule kinase inhibitors, biologic modulators, and anti-sense oligonucleotides are being evaluated for the treatment of different cancers where PKC isozymes were found to be deregulated as lung, colon, skin, prostate, and breast malignancies. In this article we will review which PKC isoforms are deregulated in different human cancers and summarize the mechanism of action of some of the major PKC modulators, analyzing the strengths and weaknesses of each one in the clinical setting.

Metastatic disease is responsible for most of cancer lethality. A main obstacle for therapy of advanced cancers is that the outcome of metastasis depends on a complex interplay between malignant and host cells. The perioperative period represents an underutilized window of opportunity for cancer treatment where tumor-host interactions can be modulated, reducing the risk of local recurrences and distant metastases. Blood-saving agents are attractive compounds to be administered during tumor surgery. Desmopressin (DDAVP) is a safe and convenient hemostatic peptide with proved antimetastastic properties in experimental models and veterinary clinical trials. The compound seems to induce a dual angiostatic and antimetastatic effect, breaking the cooperative function of cancer cells and endothelial cells during residual tumor progression. DDAVP is therefore an interesting lead compound to develop novel synthetic peptide analogs with enhanced antitumor properties.