The role of polyamines in interferon and retinoic acid mediated synergistic antiproliferative action

Combined interferon-alfa, 13-cis-retinoic acid, and alpha-tocopherol in locally advanced head and neck squamous cell carcinoma: novel bioadjuvant phase II trial

PURPOSE

Retinoids and interferons (IFNs) have single-agent and synergistic combined effects in modulating cell proliferation, differentiation, and apoptosis in vitro and clinical activity in vivo in the head and neck and other sites. Alpha-tocopherol has chemopreventive activity in the head and neck and may decrease 13-cis-retinoic acid (13-cRA) toxicity. We designed the present phase II adjuvant trial to prevent recurrence or second primary tumors (SPTs) using 13-cRA, IFN-alpha, and alpha-tocopherol in locally advanced-stage head and neck cancer.

PATIENTS AND METHODS

After definitive local treatment with surgery, radiotherapy, or both, patients with locally advanced SCCHN were treated with 13-cRA (50 mg/m(2)/d, orally, daily), IFN-alpha (3 x 10(6) IU/m(2), subcutaneous injection, three times a week), and alpha-tocopherol (1,200 IU/d, orally, daily) for 12 months, with a dose modification. Screening for recurrence or SPTs was performed every 3 months.

RESULTS

Tumors of 11 (24%) of the 45 treated patients were stage III, and 34 (76%) were stage IV. Thirty-eight (86%) of 44 patients completed the full 12-month treatment (doses modified as needed). Toxicity generally was consistent with previous IFN and 13-cRA reports and included mild to moderate mucocutaneous and flu-like symptoms; occasional significant fatigue (grade 3 in 7% of patients), mild to moderate hypertriglyceridemia in 30% of patients who continued treatment along with antilipid therapy, and mild hematologic side effects. Six patients did not complete the planned treatment because of intolerable toxicity or social problems. At a median 24-months of follow-up, our clinical end point rates were 9% for local/regional recurrence (four patients), 5% for local/regional recurrence and distant metastases (two patients), and 2% for SPT (one patient), which was acute promyelocytic leukemia (ie, not of the upper aerodigestive tract). Median 1- and 2-year rates of overall survival were 98% and 91%, respectively, and of disease-free survival were 91% and 84%, respectively.

CONCLUSION

The novel biologic agent combination of IFN-alpha, 13-cRA, and alpha-tocopherol was generally well tolerated and promising as adjuvant therapy for locally advanced squamous cell carcinoma of the head and neck. We are currently conducting a phase III randomized study of this combination (v no treatment) to confirm these phase II study results.

Phase II clinical trial of 13-cis-retinoic acid and interferon-alpha-2a in patients with advanced esophageal carcinoma

BACKGROUND

Interferon in combination with 5-fluorouracil has been shown to be active in squamous cell carcinoma (SCC) and adenocarcinoma (AC) of the esophagus. 13-cis-retinoic acid (CRA) has chemopreventive activity in SCC of the head and neck, and, in combination with interferon, has antitumor activity in SCC of the skin and cervix.

METHODS

The activity and toxicity of CRA and interferon-alpha-2a (IFN) in patients with advanced esophageal carcinoma was evaluated in a Phase II single institution trial. Patients had unresectable or metastatic AC or SCC of the esophagus. One prior chemotherapy regimen was allowed. IFN was given by daily subcutaneous injection at a dose of 3 million U and CRA was taken orally at a dose of 1 mg/kg/day in 2 divided doses. Treatment was given in cycles of 4 weeks and continued until documented disease progression.

RESULTS

Of the 19 patients entered, 15 were evaluable for response and toxicity. One patient was evaluable for response only and one patient was evaluable for toxicity only. Evaluable patients were predominantly male (15 patients), and had AC (13 patients). All had AJCC Stage IV disease and 12 were pretreated. Patients completed an average of two cycles of therapy (range, one to six cycles) prior to progression of disease. National Cancer Institute Common Toxicity Criteria Grade 3/4 toxicity was notable for nausea (25%) and fatigue (31%). No major objective responses were recorded. Eleven patients with AC and 3 patients with SCC had rapid progression of disease. One patient with AC was found to have a minor response for 22 weeks and 1 patient with AC had stable disease for 45 weeks.

CONCLUSIONS

This regimen had no significant activity in patients with advanced AC of the esophagus. Further evaluation of IFN plus CRA, using this dose and schedule, is not recommended. In comparison with prior trials of this therapy, a surprising amount of severe nausea and fatigue was observed in this trial.

Antiproliferative effects of interferon gamma in combination with alpha-difluoromethylornithine on human carcinoma cell cultures

The antiproliferative effects of human recombinant interferon gamma (IFN gamma) in combination with alpha-difluoromethylornithine (DFMO) or as single agents were assessed on human cell cultures derived from carcinomas of the breast (MCF-7), the ovary (EFO-27) or the kidneys (EGI-4). Results were obtained in proliferation assays by direct cell counting. The cell lines differed considerably in their sensitivities to the antiproliferative effect of IFN gamma as compared by the 50% inhibition doses of the growth (ID50). In contrast to the findings with IFN gamma, similar antiproliferative effects resulted from the application of comparable doses of DFMO. While IFN gamma induced cytotoxic effects in EGI-4 cells, DFMO produced only cytostatic actions in the cell lines analyzed. Synergistic growth inhibition resulted from the combined application of IFN gamma and DFMO in EFO-27 cell cultures. This finding was most pronounced after treatment with IFN gamma or DFMO doses below the respective ID50 values. However, antagonistic effects occurred in cells of the line EGI-4 after DFMO had been combined with IFN gamma at concentrations below the cytotoxic dose range. Within the sensitivity of our proliferation assay, no synergistic interactions were found in MCF-7 cell cultures. In the cell lines tested, no relation between the sensitivity for the single agents and the effectivity of the drug combination was identified. Despite promising synergistic effects in the moderately IFN gamma-sensitive ovarian carcinoma cell line EFO-27, the efficacy of the IFN gamma/DFMO combination was restrained by possible antagonistic effects as demonstrated in the highly IFN gamma-sensitive EGI-4 renal carcinoma cell cultures. We conclude that the differential interaction patterns in the cell cultures analyzed preclude general suggestions for clinical studies using IFN gamma and DFMO.

Antiproliferative and synergistic effect of interferon alpha-2a, retinoids and their association in established human cancer cell lines

The effect of 13-cis-retinoic acid (cRA) and all-trans-retinoic acid (tRA) used alone or in combination with interferon alpha-2a (alpha-IFN 2a) was tested on three established human cell lines: KB (epidermoid carcinoma of the oral cavity), SCC-25 (tongue squamous cell carcinoma) and MCF-7 (mammary carcinoma). Both retinoids significantly decreased cell proliferation (growth curves) and colony forming efficiency (CFE) in all cell lines, in a dose-dependent way (at a concentration ranging from 10(-5) to 10(-9) M) and differing from line to line, following the pattern: MCF-7 > SCC-25 > KB. Retinoids at any concentration (already at 10(-7) M) combined with alpha-IFN 2a (ranging from 100 to 500 IU/ml) were more effective in inhibiting cell proliferation than each of the two compounds alone. This was particularly evident with SCC-25 cells. Concerning MCF-7 cells, on the contrary, the effects produced by the association suggested a possible additive more than synergistic amplification of growth inhibition.

Retinoids in cancer prevention and therapy

Retinoids are a class of compounds structurally related to vitamin A. In preclinical studies, all-trans retinoic acid (tretinoin), 13-cis retinoic acid (isotretinoin) and the aromatic retinoids etretinate and acitretin have preventive and therapeutic effects on carcinogen-induced premalignant and malignant lesions. Clinically, chemoprevention with isotretinoin and etretinate has been tested with some degree of success in such indications as basal cell carcinomas, squamous cell carcinomas, superficial bladder tumors and second primary tumors in patients with squamous cell carcinoma of the head and neck. Limited therapeutic success has also been achieved with retinoid treatment of precancerous and cancerous conditions of the skin, oral cavity, larynx, lung, bladder and vulva. Dramatic therapeutic effects have been observed in the treatment of acute promyelocytic leukemia with tretinoin, which leads to very high rate of complete remission. Excellent results were recently reported in the treatment of squamous cell carcinomas of the skin and cervix with a combination of isotretinoin and recombinant interferon alfa-2a (rIFN alfa-2a, Roferon-A). The mechanism of action of retinoids is through modulation of cell proliferation and differentiation. Retinoids vary in their capacity to induce differentiation and to inhibit proliferation in a series of human transformed hematopoietic and epithelial cell lines. Some cytokines potentiate the retinoid-induced cell differentiation and act synergistically with retinoids to inhibit cell proliferation. The pattern of synergism is dependent upon the combination and tumor cell line tested. The discovery of nuclear retinoid receptors has contributed substantially to the understanding of the mechanism of action of retinoids at the molecular level. Further understanding of the molecular biology of retinoids is expected to contribute to a rational design of new retinoids in the future, which in turn may result in improvements in the prevention and therapy of cancer.

Antiproliferative activity of retinoids, interferon alpha and their combination in five human transformed cell lines

Tretinoin, isotretinoin and acitretin were examined for their capacity to modulate the proliferation of the cell lines: HL-60 (acute promyelocytic leukemia), MCF7 (mammary carcinoma), SCC4, SCC15 and A431 (squamous cell carcinomas). Retinoids inhibited proliferation to a varying extent in all 5 cell lines. The cytokine IFN alpha had a significant antiproliferative effect only on HL-60, SCC4 and SCC15. The combination of retinoids with IFN alpha led in all 5 cell lines to a more profound reduction in proliferation than either retinoids or IFN alpha alone.

Effects of interferon-gamma and its interaction with retinoic acid on human neuroblastoma differentiation

Differentiation-promoting effects of interferon-gamma (IFN-gamma), both alone and in combination with retinoic acid (RA), were studied on the human neuroblastoma cell line, LA-N-5. The results show that IFN-gamma inhibited the growth and induced morphological differentiation in a dose- and time-dependent manner with measurable effects appearing at 20-40 IU/ml after 3 to 4 days of treatment in vitro. Acetylcholinesterase activity, used as a biochemical index of neuroblastoma differentiation, increased up to 2.5-fold in the presence of IFN-gamma with a half maximal concentration of approximately 100 IU/ml. Concomitantly, modest IFN-induced increases (less than or equal to 2-fold) in choline acetyltransferase (ChAT) and tyrosine hydroxylase (TH) activities were seen. Combination treatment of cells with IFN-gamma and RA resulted in synergistic effects on morphological differentiation, growth inhibition and induction of ChAT. Reversal of IFN-gamma's ability to influence neuroblastoma cell growth as well as potentiate the anti-tumor effects of RA was obtained in the presence of an antibody against the IFN-gamma receptor, implying receptor-mediated physiological events. Taken together, these data confirm the differentiating effects of IFN-gamma on human neuroblastoma cells and suggest that combination therapy with RA may be beneficial in the treatment of this disease.