Suppression of ACADM-Mediated Fatty Acid Oxidation Promotes Hepatocellular Carcinoma via Aberrant CAV1/SREBP1 Signaling.

Lipid accumulation exacerbates tumor development, as it fuels the proliferative growth of cancer cells. The role of medium-chain acyl-CoA dehydrogenase (ACADM), an enzyme that catalyzes the first step of mitochondrial fatty acid oxidation, in tumor biology remains elusive. Therefore, investigating its mode of dysregulation can shed light on metabolic dependencies in cancer development. In hepatocellular carcinoma (HCC), ACADM was significantly underexpressed, correlating with several aggressive clinicopathologic features observed in patients. Functionally, suppression of ACADM promoted HCC cell motility with elevated triglyceride, phospholipid, and cellular lipid droplet levels, indicating the tumor suppressive ability of ACADM in HCC. Sterol regulatory element-binding protein-1 (SREBP1) was identified as a negative transcriptional regulator of ACADM. Subsequently, high levels of caveolin-1 (CAV1) were observed to inhibit fatty acid oxidation, which revealed its role in regulating lipid metabolism. CAV1 expression negatively correlated with ACADM and its upregulation enhanced nuclear accumulation of SREBP1, resulting in suppressed ACADM activity and contributing to increased HCC cell aggressiveness. Administration of an SREBP1 inhibitor in combination with sorafenib elicited a synergistic antitumor effect and significantly reduced HCC tumor growth in vivo. These findings indicate that deregulation of fatty acid oxidation mediated by the CAV1/SREBP1/ACADM axis results in HCC progression, which implicates targeting fatty acid metabolism to improve HCC treatment. SIGNIFICANCE: This study identifies tumor suppressive effects of ACADM in hepatocellular carcinoma and suggests promotion of ß-oxidation to diminish fatty acid availability to cancer cells could be used as a therapeutic strategy.

Outpatient subcutaneous interleukin-2 and interferon-alpha for metastatic renal cell cancer: five-year follow-up of the Cytokine Working Group Study.

PURPOSE: A phase II trial of outpatient subcutaneous (SC) interleukin-2 (rIL-2) plus interferon-alpha (IFN-alpha 2B) was performed in patients with metastatic renal cell cancer. A 5-year follow-up of that Cytokine Working Group study is presented. PATIENTS AND METHODS: Forty-seven patients meeting eligibility criteria of previous Cytokine Working Group studies were treated on an outpatient basis with SC rIL-2 (Chiron, Emeryville, CA), 5 x 10(6) IU/m2/dose q 8 hr x 3, then daily, 5 days per week, and IFN-alpha 2B (Schering-Plough, Kenilworth, NJ), 5 x 10(6) IU/m2/dose three times weekly for 4 weeks. After a 2- to 4-week break, patients were scheduled to continue treatment for up to six cycles. RESULTS: There were two complete and six partial responders (17% response rate, 95% CI: 8%-31%). Median duration of response was 12 months (range 1-49+ months), with complete responses of 15 and 49+ months. Responding sites of disease included lung, nodes, soft tissue, bone, and liver. Dose and schedule were adjusted to control toxicity at grade 2/3 levels, with 50% requiring dosage alterations. Grade 2/3 toxicity included fatigue, nausea/vomiting, diarrhea, anorexia, fluid overload, rash, CNS, injection site pain, chest pain/palpitations (including atrial fibrillation requiring treatment, two patients), and hypotension. Grade 4 toxicity included dehydration (seven patients), vomiting (one patient), and irreversible renal failure with crescentic glomerulonephritis requiring dialysis (one patient). CONCLUSION: SC rIL-2 plus IFN-a2B is tolerated in the outpatient setting with frequent dose adjustments. The overall response rate of this regimen is similar to that seen with high-dose rIL-2 alone; however, the response duration appears to be shorter.

Concurrent phase I trials of intravenous interleukin 6 in solid tumor patients: reversible dose-limiting neurological toxicity.

Interleukin 6 (IL-6) has antitumor activity comparable to IL-2 in murine models with less toxicity. Because the biological effects of intermittent and continuous infusions may differ, we conducted two concurrent Phase I trials of daily x5, 1-h, and continuous 120-h i.v. infusions to determine the toxicity, biological effects, and maximum tolerated dose of i.v. IL-6. Cohorts of six patients with advanced cancer received escalating doses (1, 3, 10, 30, 100, and 150 microgram/kg/day) of recombinant human IL-6 on days 1-5 and 8-12 of each 28-day course (1-h trial) or on days 1-5 of each 21-day course (120-h trial). Treatment was administered in regular inpatient wards and in outpatient clinics and was withheld in the event of grade 3 toxicity. Sixty-nine patients (1-h trial, n = 40; 120-h trial, n = 29) were enrolled, including 27 with renal cancer and 16 with melanoma. All were ambulatory, and 40 were asymptomatic. Fever (97%), anemia (78%), fatigue (56%), nausea or vomiting (49%), and elevated serum transaminase levels (42%) were the most frequent toxicities. Transient hypotension developed in 23 patients (33%). There were three deaths during the study due to progressive disease and/or infection. There were no objective responses. Dose-related increases in platelet counts and C-reactive protein levels were detected in most patients. Principal dose-limiting toxicities included atrial fibrillation (1 episode in the 1-h trial and 4 episodes in the 120-h trial) and neurological toxicities (3 episodes in the 1-h trial and 4 episodes in the 120-h trial). The neurological toxicities included confusion, slurred speech, blurred vision, proximal leg weakness, paraparesis, and ataxia. These effects were transient and reversed when IL-6 was discontinued. IL-6 can be given by i.v. infusion at biologically active doses with acceptable toxicity. Dose-limiting toxicities consisted mainly of a spectrum of severe but transient neurological toxicities and occasional episodes of atrial fibrillation. The maximum tolerated doses recommended for use with these i.v. schedules in Phase II trials are 100 microgram/kg/day by daily x5 1-h infusion and 30 microgram/kg/day by 120-h infusion. Phase II trials will be performed to determine the antitumor activity of IL-6 and better define its toxicity. Patients in these and other IL-6 studies should be monitored closely for neurological and cardiac effects.

A carboplatin-based regimen for the treatment of patients with advanced transitional cell carcinoma of the urothelium.

BACKGROUND: Many patients with advanced transitional cell carcinoma are unable to receive cisplatin-based therapy. The efficacy and toxicity of a carboplatin-based regimen in the treatment of patients with advanced transitional cell carcinoma was therefore evaluated. METHODS: Twenty-three patients with advanced transitional cell carcinoma were treated. Metastatic disease was present in 19 of 23 patients (83%) whereas 4 patients with T4, and/or N1, disease were treated. Patients were treated every 28 days with methotrexate, 30 mg/m2 intravenously (i.v.) on Days 1 and 15, along with leucovorin, 15 mg/m2 orally every 6 hours, 3 times daily beginning 24 hours after each methotrexate dose; vinblastine, 3 mg/m2 i.v. on Days 1 and 15; mitoxantrone, 15 mg/m2 i.v. on Day 1; and carboplatin, 300 mg/m2 i.v. on Day 1, adjusted for creatinine clearance (MVNCa). Dosage in subsequent cycles was adjusted according to hematologic toxicity. RESULTS: Median age was 70 years (range, 52-83 years) and median pretreatment creatinine clearance was 50 mL/min (range, 30-106 mL/min). Of 23 patients, 8 (34.8%) obtained a complete response, and 5 (21.7%) obtained a partial response. The overall response proportion was 56.5% (95% confidence interval, 34.5-76.8%). Median survival was 10 months (range, 1-44+ months). Toxicity was moderate. Grade 4 neutropenia occurred in 10 of 107 (9.3%) administered treatment cycles; Grade 4 thrombocytopenia occurred in 11 of 107, (10.3%). There were 4 episodes of febrile neutropenia (3.7% of cycles). Renal, neurologic, or otic toxicity were not observed. Age older than 70 did not appear to impact on response proportion, survival, and toxicity. CONCLUSIONS: The carboplatin-based MVNCa regimen is active in the treatment of patients with advanced transitional cell carcinoma and is well tolerated. Therapy with this regimen may be a less toxic alternative for patients for whom treatment with cisplatin is not an option.

Multiinstitutional phase II trial of intensive combination chemoimmunotherapy for metastatic melanoma.

PURPOSE: To evaluate the activity and toxicity of combined high-dose cisplatin, dacarbazine (DTIC), and tamoxifen chemotherapy and high-dose bolus interleukin-2 (IL-2) in patients with metastatic melanoma. PATIENTS AND METHODS: Patients with metastatic melanoma, Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and normal organ function were enrolled onto this multiinstitutional Cytokine Working Group trial. Patients received intensive chemoimmunotherapy consisting of cisplatin (50 mg/m2) and DTIC (350 mg/m2) intravenously (IV) on days 1 to 3 and 43 to 45, IL-2 600,000 IU/kg IV every 8 hours on days 12 to 16 and 26 to 30 (maximum, 28 doses), and tamoxifen 20 mg orally each day. Patients were evaluated for response at day 63 of each cycle, and responding patients were given a second cycle of therapy beginning on day 71 to 85. RESULTS: Thirty-eight patients were entered onto this study. Toxicities were as expected for the chemotherapy and immunotherapy components of this regimen. Overlapping toxicity consisted primarily of thrombocytopenia (76% of patients required platelet transfusions), neutropenia, anemia, fatigue, and weight loss. Despite these cytopenias, bleeding and infectious complications were rare. There were no treatment-related deaths. Three patients achieved a complete response (CR; 8%), and 13 achieved a partial response (PR). The overall objective response rate was 42% (95% confidence interval [CI], 26% to 58%). Six additional patients had greater than 50% tumor reduction at day 63, which did not persist until a subsequent evaluation. The median duration of response was 5 months (range, 2 to 20+), and the median survival duration was 11 months. CONCLUSION: This intensive treatment regimen appears to possess activity in metastatic melanoma comparable, but not superior, to that of other less intensive cisplatin- and IL-2-based chemoimmunotherapy regimens. Although the toxicity and complexity of this regimen make it unsuitable for phase III testing and impractical for more widespread use, the results of this study support a potential favorable interaction between IL-2 and chemotherapy in this disease and highlight the need for appropriately designed phase III trials.

A phase I/II study of alternating constant rate infusion floxuridine with constant rate infusion vinblastine for the treatment of metastatic renal cell carcinoma.

BACKGROUND: Metastatic renal cell carcinoma (RCC) is largely chemoresistant. The efficacy of cell cycle specific chemotherapeutic agents, particularly those with short half-lives, may be enhanced by the use of constant rate infusion schedules. Infusional floxuridine has been demonstrated to have a response rate of approximately 20%. Infusional vinblastine has not been tested extensively in patients with metastatic RCC. The sequential use of these agents was designed to increase efficacy and limit toxicity. METHODS: Fifteen patients with metastatic RCC were treated with constant rate infusion floxuridine, 0.075 mg/kg/day for 14 days, followed by a constant rate infusion of vinblastine, 0.7 mg/m2/day for 14 days. The cycle repeated every 28 days and floxuridine and vinblastine doses were incrementally increased until the maximum tolerated dose (MTD) for each patient was reached. RESULTS: Four patients had partial responses (27%), which were maintained for 3, 9, 16 and 19+ months, whereas five patients had stable disease for 3-15 months. Median survival from initiation of therapy was 379 days. Three of four responses occurred in nonpulmonary locations, and all responses occurred in patients who had a prior nephrectomy. MTD for floxuridine was 0.1 mg/kg/day and for vinblastine, 0.7 mg/m2/day. Toxic reaction to floxuridine was limited to diarrhea, whereas the principle dose-limiting toxic reaction for vinblastine was neutropenia. Catheter-related complications were also observed. CONCLUSIONS: Alternating constant rate infusion floxuridine and constant rate infusion vinblastine is active in the treatment of metastatic RCC. Whether this regimen is superior to infusional floxuridine is undetermined. Although the toxicity associated with this regimen is manageable, it appears to be more severe than that reported with infusional floxuridine alone.

Phase II studies of recombinant human interleukin-4 in advanced renal cancer and malignant melanoma.

Interleukin (IL-4) is a pluripotent cytokine that stimulates proliferation of activated T-cells and has antineoplastic activity against human renal tumors in animal systems. In phase I trials, IL-4 could be tolerated at doses up to 20 micrograms/kg, with dose-limiting toxicities consisting of fever, fluid retention, nasal congestion, and mucositis. We report the results of two separate Phase II trials of IL-4 in 30 patients with metastatic malignant melanoma and 19 patients with advanced renal cancer. IL-4 was administered intravenously every 8 h for 14 doses in two 5-day courses separated by a 9-day interval. The first 27 patients were treated at a dose of 800 micrograms/m2, but after three of these patients developed cardiac toxicities, the dose was decreased to 600 micrograms/m2. One complete response occurred in a patient with metastatic melanoma (duration > or = 30 months). No responses were seen among the patients with renal cancer. The most frequent side effects were fever, nausea, malaise, nasal congestion, and diarrhea. Reversible hepatic and renal dysfunction were also common. Hypotension was infrequent, but transient weight gain due to fluid retention was common. The major life-threatening toxicities were cardiac and gastrointestinal. Suspected cardiac ischemia was observed in two patients, pericarditis in one, and arrhythmias in two. Three patients had major upper gastrointestinal bleeding without evidence of local tumor. We conclude that IL-4, when given as a single agent on this schedule at maximum tolerated dose, does not possess meaningful activity in renal cancer or melanoma.

Randomized phase III trial of treatment with high-dose interleukin-2 either alone or in combination with interferon alfa-2a in patients with advanced melanoma.

PURPOSE: To compare the response rate, survival, and toxicity of treatment with high-dose intravenous (IV) bolus interleukin-2 (IL-2) plus interferon alfa-2a (IFN-alpha) with high-dose IL-2 alone in patients with advanced melanoma in a randomized phase III trial design. PATIENTS AND METHODS: Eighty-five patients with advanced melanoma were randomly assigned to receive IL-2 6 X 10(6) U/m2 per dose every 8 hours as tolerated for a maximum of 14 doses on days 1 through 5 and 15 through 19, or IL-2 4.5 X 10(6) U/m2 per dose, plus IFN-alpha 3 X 10(6) U/m2 using an identical schedule. A planned interim analysis was performed after 85 patients were entered, which forms the basis for this report. RESULTS: Partial response (PR) occurred in two of 44 patients (5%; 95% confidence interval, 1% to 15%) receiving IL-2 alone, compared with four of 41 patients (10%; 95% confidence interval, 3% to 23%) receiving IL-2/IFN-alpha (P = .30). There were no complete responses (CRs). The median duration of response was 11.5 months (range, 2.0 to 15.7+). There was no significant difference in the median survival duration for patients receiving IL-2 alone (10.2 months) compared with patients receiving IL-2/IFN-alpha (9.7 months). The median and mean number of doses of IL-2 were equivalent in both groups, as was toxicity. There were three treatment-related deaths, two in the IL-2-alone arm and one in the IL-2/IFN-alpha arm. The trial was terminated after the first interim analysis based on predefined early-stopping rules, which included termination if the response rate in the IL-2/IFN-alpha arm was less than 25%. CONCLUSION: Using the preparation, dose, and schedule of IL-2 in our trial, IFN-alpha failed to enhance significantly the response rate to high-dose IL-2 in the treatment of patients with advanced melanoma.

A phase II study of constant-infusion floxuridine for the treatment of metastatic renal cell carcinoma.

BACKGROUND: Twenty-nine patients with metastatic renal cell carcinoma (RCC) were treated with constant-infusion floxuridine (FUdR, Roche Laboratories, Nutley, NJ). METHODS: The initial dosage was 0.075 mg/kg/day for 14 days every 28 days and was increased or decreased by 0.025-mg/kg/day increments at each subsequent cycle until the maximum tolerated dose (MTD) was achieved. RESULTS: All patients were fully assessable. One (4%) patient had a complete response, 5 (17%) had a partial response, 13 (50%) had stabilized disease, and 10 (34%) had progressive disease. The treatment-limiting toxic effect was diarrhea, and the median tolerated dosage was 0.1 mg/kg/day for 14 days every 28 days (range, 0.05-0.275 mg/kg/day). Five of the six responses occurred at a dosage of 0.1 mg/kg/day or less, which was achievable in most patients. Patients who reached their MTD without achieving a complete or partial response were switched to circadian-infusion floxuridine to determine whether an increased dose intensity could be administered and whether this would translate into additional responses. A higher median tolerated dosage of 0.15 mg/kg/day was achieved with circadian administration; however, no additional responses were observed. The median survival time was 891 days after the diagnosis of metastatic RCC and 445 days after the institution of floxuridine therapy. CONCLUSIONS: Constant-infusion floxuridine is active against metastatic RCC and produces a response rate that appears to be comparable to that of circadian administration of floxuridine.

Hypogonadal impotence treated by transdermal testosterone.

The transdermal therapeutic system for testosterone (TTS-T) (ALZA Corp.), applied to the scrotal skin for twenty-two hours daily, was tested for twelve weeks on 4 men with hypogonadal impotence; 2 of these men wore TTS-T for as long as twenty-six months. The 40 cm2 system delivered a daily dose of 2.8 +/- 0.16 (S.E.) mg (nominal dose 2.4 mg) and the 60 cm2 system delivered a dose of 3.99 +/- 0.24 mg (nominal dose 3.6 mg). Both systems promptly increased serum testosterone and dihydrotestosterone (DHT) to physiologic levels, restoring normal erectile activity with an increased frequency of ejaculation and a positive effect on both mood and energy. There were no changes in serum sex binding globulin and estradiol, prostate or breast size, hematologic or liver function measures, or urinary flow and frequency. There were no significant changes in serum cholesterol or low-density lipoproteins, but high-density lipoproteins tended to decline slightly. There were no dermatologic problems associated with the system. The tenfold increase in DHT over baseline levels was attributed to 5-alpha reduction of testosterone in the scrotal skin. The TTS-T is convenient, reliable, and mimics normal physiologic testosterone secretion and levels more closely than conventional methods of testosterone replacement.