No abstract

Medical treatment of metastatic adrenal cancer is largely unsuccessful and has considerable toxicity. We previously demonstrated the activity of the plant toxin gossypol against human adrenal cancers in nude mice. We therefore examined the efficacy and toxicity of oral gossypol as a treatment for adrenal cancer in humans. Twenty-one patients with metastatic adrenal cancer received oral gossypol at doses of 30-70 mg/day. Patients were monitored for side effects of gossypol, changes in hormone secretion, and tumor response. Eighteen patients completed at least 6 weeks of gossypol treatment. Three of these patients, whose tumors were refractory to other chemotherapeutic agents, had partial tumor responses (> or = 50% decrease in tumor volume) that lasted from several months to over 1 yr. One patient had a minor response followed by resection of her remaining disease, 1 patient had stable disease, and 13 patients had disease progression. Three patients died of their disease without receiving sufficient gossypol to achieve detectable drug levels, and were eliminated from the final analysis. The side effects of gossypol were generally well tolerated; the only serious side effect was abdominal ileus that resolved when the drug was temporarily withheld and restarted at a lower dose. We conclude that oral gossypol can be used relatively safely on an outpatient basis for the treatment of metastatic adrenal cancer. The response rate is similar to the other agents currently available for adrenal cancer, and responses were seen in patients who had failed other chemotherapeutic regimens. This study provides the first indication that gossypol may have activity against cancer in humans, suggesting the need for further investigation of gossypol as an antitumor agent.

Summary The antiproliferative effects of gossypol on human MCF-7 mammary cancer cells and cyclin Dl-transfected HT-1060 human fibrosarcoma cells were investigated by cell cycle analysis and effects on the cell cycle regulatory proteins Rb and cyclin Dl. Flow cytometry of MCF-7 cells at 24 h indicated that 10 gm gossypol inhibited DNA synthesis by producing a G,/S block. Western blot analysis using antihuman Rb antibodies and anti-human cyclin Dl antibodies in MCF-7 cells and high-and low-expression cyclin Dl-transfected fibrosarcoma cells indicated that, after 6 h exposure, gossypol decreased the expression levels of these proteins in a dose-dependent manner. Gossypol also decreased the ratio of phosphorylated to unphosphorylated Rb protein in human mammary cancer and fibrosarcoma cell lines. Gossypol (10 gM) treated also decreased cyclin D1-associated kinase activity on histone Hi used as a substrate in MCF-7 cells. These results suggest that gossypol might suppress growth by modulating the expression of cell cycle regulatory proteins Rb and cyclin Dl and the phosphorylation of Rb protein.

To better understand the use of narcotic analgesics, the hydromorphone concentration was measured in serum samples from 43 patients with chronic severe pain who were receiving this drug. At the time of blood sampling, pain intensity, mood, and cognitive performance were assessed. There was large individual variation in the dose-drug level relationship. Seven patients with bone or soft tissue pain and drug levels of greater than or equal to 4 ng/ml had good pain control, whereas 10 did not. None of 15 patients with levels less than 4 ng/ml had pain control, despite drug doses similar to those given patients with higher levels. Thus 60% of the patients without control of their pain had hydromorphone levels below the lowest level that produced pain control. No patient with pain from nerve infiltration or compression had good pain control, irrespective of the drug level or dose. Poor mood correlated with high pain intensity and low drug level. Impaired cognitive performance was not related to drug level. Knowing that there is a low concentration of narcotic in the blood of a patient with chronic severe pain who is receiving high drug doses and who shows lack of both efficacy and side effects may reassure health care professionals that further narcotic dosage escalation is appropriate.