Mitomycin C plasma levels after intravesical instillation with and without hyaluronidase

Intravesical treatments of bladder cancer: review

For bladder cancer, intravesical chemo/immunotherapy is widely used as adjuvant therapies after surgical transurethal resection, while systemic therapy is typically reserved for higher stage, muscle-invading, or metastatic diseases. The goal of intravesical therapy is to eradicate existing or residual tumors through direct cytoablation or immunostimulation. The unique properties of the urinary bladder render it a fertile ground for evaluating additional novel experimental approaches to regional therapy, including iontophoresis/electrophoresis, local hyperthermia, co-administration of permeation enhancers, bioadhesive carriers, magnetic-targeted particles and gene therapy. Furthermore, due to its unique anatomical properties, the drug concentration-time profiles in various layers of bladder tissues during and after intravesical therapy can be described by mathematical models comprised of drug disposition and transport kinetic parameters. The drug delivery data, in turn, can be combined with the effective drug exposure to infer treatment efficacy and thereby assists the selection of optimal regimens. To our knowledge, intravesical therapy of bladder cancer represents the first example where computational pharmacological approach was used to design, and successfully predicted the outcome of, a randomized phase III trial (using mitomycin C). This review summarizes the pharmacological principles and the current status of intravesical therapy, and the application of computation to optimize the drug delivery to target sites and the treatment efficacy.

Hyaluronan metabolism: a major paradox in cancer biology

Paradoxically, both hyaluronan (HA) and hyaluronidases, the enzymes that eliminate HA, can correlate with cancer progression. Levels of HA on the surface of tumor cells are indicators of poor outcome. Certain hyaluronidases, products of tumor suppressor genes eliminated in the course of tumor spread, are used clinically in anti-cancer chemotherapy regimens. Such information would indicate that cancer progression is inhibited by hyaluronidase. Yet progression of certain cancers correlates with levels of hyaluronidase activity. An attempt is made here to understand such apparent contradictions by examining details of HA metabolism. Anabolic and catabolic pathways are comprised of the HA synthases and hyaluronidases, respectively. There are several enzymes that synthesize HA, each under a different control mechanism, generating products of differing polymer size. The hyaluronidases degrade HA in step-wise fashion, the polymer decreasing in size in quantum steps, each size-specific polymer having a different biological activity. Superimposed on these are the potent hyaluronidase inhibitors, about which very little is known. These components of HA metabolism are reviewed here for possible roles in supporting or suppressing malignant transformation, growth, invasion and metastatic spread of tumors. Such a systematic approach may reveal mechanisms used in the course of cancer progression, resolve some of the apparent disparities, render new prognostic markers, and provide new targets for therapeutic intervention.

Secretion of bladder tumor-derived hyaluronidase activity by invasive bladder tumor cells

Hyaluronic acid (HA), a glycosaminoglycan, promotes tumor metastasis and its small fragments are angiogenic. These small fragments are generated by degradation of HA by hyaluronidase (HAase). We measured urinary HAase levels of 196 individuals using an ELISA-like assay. The urinary HAase levels (31.1 +/- 3.7 mU/mg) of intermediate (G2) to high-grade (G3) bladder cancer patients are five- to seven-fold elevated as compared to those of normal individuals and patients with other genitourinary conditions or low-grade (G1) bladder cancer. The increase in urinary HAase levels is due to the secretion of a tumor-derived HAase which is elevated eight-fold in G2/G3 tumor tissues. The HAase in bladder tumor tissues is secreted by tumor epithelial cells and is associated with the invasive/metastatic potential of the tumor cells.

Chromatographic analysis of anticancer drugs

The present review on the methods for the analysis of anticancer drugs should be seen as an addition to the excellent work of Eksborg and Ehrsson published half a decade ago in this journal (Vol. 340, p.31). The style and format have been followed closely, with the focus again on chromatographic techniques. We felt it important to add a list of compound (group) structures as a service to the reader. Methods have been reviewed for alkylating agents, platinum compounds, antitumour antibiotics, antimetabolites, alkaloids, suramin, 1-hydroxy-3-amino-propylidene-1,1-bisphosphonate and tamoxifen.

Metaphylactic effect of mitomycin C with and without hyaluronidase after transurethral resection of bladder cancer: randomized trial

In a randomized trial 2 groups of 28 patients who had undergone transurethral resection of bladder tumors were treated with 20 mg. mitomycin C alone or with 200,000 units hyaluronidase to determine whether adjuvant hyaluronidase would improve tumor recurrence rates. Patient groups were comparable statistically. In the group receiving additive hyaluronidase the percentage of tumor recurrences was decreased significantly (p less than 0.05). Side effects were not increased. Thus, adjuvant hyaluronidase appears to have a role in the metaphylaxis of bladder tumors. The potential reduction of the hyaluronidase dose without loss of protective action and the role of additive hyaluronidase in the systemic treatment of metastatic urothelial tumors remain to be investigated.