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

Signal Transducers and Activators of Transcription: Insights into the Molecular Basis of Oral Cancer

Recent efforts on developing more direct and effective targets for cancer therapy have revolved around a family of transcription factors known as STATs (signal transducers and activators of transcription). STAT proteins are latent cytoplasmic transcription factors that become activated in response to extracellular signaling proteins. STAT proteins have been convincingly reported to possess oncogenic properties in a plethora of human cancers, including oral and oropharyngeal cancer. Signal transduction pathways mediated by these oncogenic transcription factors and their regulation in oral cancer are the focus of this review.

Systemic treatment of locally advanced nonmetastatic cutaneous squamous cell carcinoma: a review of the literature

BACKGROUND

There is a small subset of locally advanced nonmetastatic cutaneous squamous cell carcinoma (cSCC) for which local therapy is not curative or feasible, making systemic therapy a possible treatment option.

OBJECTIVES

To calculate overall response rates (ORR), median time to response (TTR) and median duration of response (DOR) of locally advanced nonmetastatic cSCC to systemic therapy [targeted agents, biological response modifiers (BRM) and chemotherapy].

PATIENTS AND METHODS

Medline and PubMed were searched for reports of nonmetastatic locally advanced cSCC treated with systemic therapy from 1970 to 2011. No limits were placed on study design. ORR, TTR and DOR were calculated for systemic therapy overall and for each treatment category.

RESULTS

Twenty-eight observational studies yielded 119 patients for analysis. The ORR for systemic therapy was 72% (TTR 9 weeks, DOR 42 weeks). Targeted therapy and BRM achieved ORR of 100% (TTR 12 weeks, DOR 20 weeks) and 86% (TTR 10 weeks, DOR 20 weeks), respectively, and oral chemotherapy, intravenous chemotherapy and intra-arterial chemotherapy achieved ORR of 20% (TTR 10 weeks, DOR 24 weeks), 68% (TTR 3 weeks, DOR 44 weeks) and 100% (TTR 15 weeks, DOR 112 weeks), respectively. A limitation of this study was that no controlled data were identified and sample sizes were small.

CONCLUSIONS

Systemic treatment leads to objective responses in locally advanced cutaneous SCC that are not amenable to local cure.

Phase 2 Bioadjuvant Study of Interferon Alfa-2a, Isotretinoin, and Vitamin E in Locally Advanced Squamous Cell Carcinoma of the Head and Neck

OBJECTIVE

To evaluate the long-term effects of the combination of isotretinoin, interferon alfa-2a, and vitamin E in locally advanced squamous cell carcinoma of the head and neck.

DESIGN

Phase 2 prospective study.

SETTING

Tertiary care academic medical centers.

PATIENTS

Forty-five patients entered this study. All patients had stage III or IV squamous cell carcinoma of the head and neck and had been treated with surgical resection, radiation, or both. All patients were then treated with bioadjuvant chemopreventive treatment for 12 months. We previously reported a 24-month median follow-up of this phase 2 trial of the combination of isotretinoin, interferon alfa-2a, and vitamin E as bioadjuvant therapy after definitive local therapy. In that study, all 45 patients completed treatment, but 1 patient was excluded from analysis of recurrence and development of second primary tumors. Main Outcome Measure Longer-term (49.4-month median) follow-up.

RESULTS

Among the 45 patients treated under the protocol, only 7 patients (16%) had died. Nine (20%) of 45 patients experienced progressive disease. Only 1 second primary tumor (acute promyelocytic leukemia) occurred during follow-up, and no aerodigestive second primary tumors occurred among the 45 patients. The 5-year progression-free survival and overall survival percentages were 80% (95% confidence interval, 65.1%-89.1%) and 81.3% (95% confidence interval, 63.7%-90.9%), respectively. These results are significantly better than the historical 5-year overall survival for advanced squamous cell carcinoma of the head and neck (approximately 40%).

CONCLUSION

The bioadjuvant combination is highly effective in preventing recurrence and second primary tumors, and its role as standard therapy in advanced squamous cell carcinoma of the head and neck is being investigated in a randomized phase 3 study.

Altered chemical and biological activities of all-trans retinoic acid incorporated in solid lipid nanoparticle powders

The principal aim of this study was to investigate whether the solid lipid nanoparticle (SLN) powder formulation of all-trans retinoic acid (ATRA) can favorably alter the chemical stability and biological activities of ATRA. SLN powder formulation of ATRA was obtained by freeze-drying of SLN dispersions. The chemical stability of ATRA was determined by HPLC analysis. The anticancer efficacy of ATRA was determined by evaluating antiproliferative effects of ATRA on cancer cell lines. Hemolytic potential of ATRA was spectrophotometrically determined after incubation with red blood cells (RBCs) in vitro. ATRA could be efficiently incorporated in SLN powder without impairing the physical stability of lipid nanoparticles. After 3 months of storage, >90% ATRA remained intact in SLN powder, indicating that the chemical stability of ATRA was substantially improved by incorporation in SLN powder. The antiproliferative effects of SLN powder formulation of ATRA on a wide range of cancer cell lines were not significantly different from that of free ATRA. Furthermore, the incorporation of ATRA in SLN powder significantly reduced the hemolytic potential of ATRA. Taken together, the molecular characteristics that currently appear to limit the clinical efficacy of ATRA were greatly improved by preparing SLN powder formulation. SLN powder formulation of ATRA may have a potential in enhancing the efficacy of ATRA in cancer chemoprevention and therapeutics.

Phospholipid-based microemulsion formulation of all-trans-retinoic acid for parenteral administration

All-trans-retinoic acid (ATRA) shows anti-cancer activities, especially in patients with acute promyelocytic leukemia. Due to the highly variable bioavailability of ATRA and induction of its own metabolism after oral treatment, development of alternative parenteral dosage form is required. The principal aim of this study was to develop a parenteral formulation of ATRA by overcoming its solubility limitation by utilizing phospholipid-based microemulsion system as a carrier. Microemulsion was prepared with pharmaceutically acceptable ingredients such as soybean oil and phospholipids. The mean particle diameter and polydispersity of ATRA microemulsion could be decreased to be applicable for parenteral administration by modulation of composition of microemulsion. The loading concentration of ATRA in microemulsion increased by increasing the oil contents and also by inclusion of distearoylphosphatidyl-ethanolamine-N-poly(ethyleneglycol) 2000 (DSPE-PEG). Furthermore, loading of ATRA in microemulsion improved the chemical stability of ATRA. The pharmacokinetic profile of ATRA after intravenous injection of microemulsion formulation to rats was similar to that of sodium ATRA. The growth inhibitory effects of ATRA on human cancer HL-60 and MCF-7 cell lines were also similar between free ATRA and microemulsion formulation of ATRA, suggesting that its anti-cancer activity was not impaired by loading in microemulsion. Our study herein demonstrates that phospholipid-based microemulsion may provide an alternative parenteral formulation of ATRA.

Effects of 13-cis-retinoic acid on chemoimmunotherapy of metastatic renal cell carcinoma--results of a retrospective analysis

Chemoimmunotherapy (CIT) with interleukin-2, interferon-alpha2a, and 5-fluorouracil is an accepted treatment option of metastatic renal cell carcinoma (mRCC). Because of the enhancement of the antiproliferative effects of interferon-alpha2a, 13-cis-retinoic acid (13-CRA) might be of potential usefulness for immunotherapy. We have investigated the effect of 13-CRA in patients treated with chemoimmunotherapy. Seventy-two patients with mRCC and a Karnofsky performance index > or = 80% were retrospectively analyzed. Thirty-six patients received chemoimmunotherapy and 36 other patients were treated similarly but with addition of daily 60 mg 13-CRA. Response was assessed according to the UICC criteria. Survival was calculated by Kaplan Meier estimation and compared with the log-rank test. In the CIT group objective remissions occurred in 34.3% (95% CI 19.1-52.2) and stabilizations in 42.9% (median follow-up 16 months). In the CIT plus 13-CRA group, objective remissions were seen in 26.4% (95% CI 12.9-44.4) and stabilizations in 50% (median follow-up 17 months). One- and three-year survival rates were 76% and 32% in the CIT group and 82% and 37% in the CIT plus 13-CRA group. The combination of CIT and 13-CRA did not significantly differ in objective remissions and estimated survival compared with CIT. Our retrospective data suggest that 13-CRA does not enhance the therapeutic efficacy of CIT in mRCC patients with a good performance status.

Effect of all-trans-retinoic acid on the hypercoagulable state of patients with breast cancer

To evaluate whether all-trans-retinoic acid (ATRA) is able to modulate the hemostatic system in patients with solid tumors, we studied patients with locally advanced breast cancer who were enrolled in a Phase Ib study of ATRA +/- Tamoxifen (Tam). In this study, two groups of 15 patients/each were treated for 21 days before operation with ATRA at three doses (15, 45, or 75 mg/m(2)/day on alternate days) given alone (group 1) or in combination with Tam (group 2). One additional group received Tam alone. Plasma samples were evaluated for hypercoagulation markers (FVIIa, F1+2, TAT, D-dimer), fibrinolysis proteins (t-PA, PAI-1), and coagulation inhibitors (protein C, AT). At baseline, cancer patients had FVIIa, F1+2, TAT, and PAI-1 significantly greater than control subjects. During treatment, in the patients given ATRA alone, hypercoagulation markers appeared unmodified. Instead, subjects given Tam alone had a significant elevation of FVIIa, F1+2, and TAT versus baseline. However, in the ATRA + Tam groups, hypercoagulation markers were decreased compared with Tam alone. These results suggest that in selected conditions, pre-operative ATRA may modulate the hypercoagulable state of breast cancer patients.

Advanced carcinoma of the pancreas: phase II study of combined chemotherapy, beta-interferon, and retinoids

Because of the poor response of pancreatic cancer to conventional therapy, the authors performed a phase II pilot study to evaluate whether beta-interferon and retinoids, added to active chemotherapeutic agents, could increase response rate and survival in a group of patients who had metastatic disease. Twenty-three chemotherapy-naive patients were treated as follows: epirubicin, 60 mg/m2, and mitomycin C, 10 mg/m2, intravenously on day 1; folinic acid, 200 mg/m2, and 5-fluorouracil (5-FU), 370 mg/m2, intravenously for 5 consecutive days. beta-Interferon, 1 x 10(6) IU/m2, subcutaneously three times a week, and retinol palmitate, 50,000 IU orally twice a day, were given between chemotherapy cycles. Patients having responses and disease stabilization were maintained with the same dose of beta-interferon and retinol palmitate. Treatment was given every 4 weeks for four courses or until onset of progression. A median of three courses of chemotherapy was delivered to each patient. All patients were evaluable. Eight patients responded (35%) and 8 (35%) had stable disease. Median time to progression and survival for all patients were, respectively, 6.1 months and 11 months. Toxicity was severe: 60% of patients had hematologic toxicity, 40% had gastrointestinal toxicity, 13% had cardiac toxicity, and 1 patient had a hemolitic-uremic syndrome. The combination of chemotherapy, beta-interferon, and retinoids shows activity in metastatic pancreatic carcinoma. Toxicity was high but patients who had responses and disease stabilization had prolonged symptom palliation.

An Eastern Cooperative Oncology Group phase I trial of all-trans-retinoic acid and interferon-alpha: E2Y92

The Eastern Cooperative Oncology Group conducted a Phase I trial to determine the maximally tolerated doses of combination therapy with alpha interferon (IFN-alpha) and all-trans-retinoic acid (tRA). Fifty patients with incurable malignancies received IFN-alpha administered subcutaneously three times weekly, and tRA administered by mouth at bedtime. Doses were escalated between patient groups, starting at tRA dose level of 45 mg/m2 and 3 million units of IFN-alpha. Major, dose-limiting toxicities were attributable to either the tRA (rash, chelitis) or IFN (constitutional symptoms), and were observed only at tRA dose levels of 224 mg/m2 and 291 mg/m2, or 6 million units of IFN-alpha. The maximally tolerated dose level of 172.5 mg/m2 of tRA and 3 million units of IFN-alpha was well-tolerated, with no grade 3 or 4 toxicities attributable to therapy. One patient at the third dose level (75 mg/m2 of tRA and 3 million units of IFN-alpha) developed acute hepatic and renal failure and a metabolic encephalopathy of unclear etiology. We conclude that tRA and IFN-alpha may be safely administered together at the maximally tolerated dose of tRA as a single agent without unexpected side effects. The recommended doses of IFN-alpha and tRA for Phase II trials are 3 million units of IFN-alpha and 172.5 mg/m2 of tRA.

The effects of 13-cis retinoic acid and interferon-alpha in chronic myelogenous leukemia cells in vivo in patients

The effects of the administration of a 3-day course of 13-cis retinoic acid in combination with interferon a [RA/IFN] on the leukemia cells was measured in vivo in 43 patients with chronic myelogenous leukemia. The administration of RA/IFN was associated with a significant fall in the white blood cell count of patients with chronic-phase disease and with a fall in the percentage S-phase cells in CML patients regardless of the stage of their leukemia. In two thirds of the patients studied the administration of RA/IFN was also associated with an increase in marrow apoptosis. The cytokine combination also suppressed bcl-2 and myc expression in a minority of patients and such expression appears to be associated with response to a treatment regimen which includes RA/IFN. These studies are the first to directly assess the effects of the combination of RA/IFN on chronic myelogenous leukemia cells in vivo in patients. These effects, if seen in other malignant diseases, could account for the therapeutic benefit which has been associated with the administration of this combination of biological agents to patients with malignant disease.

Synergistic effect between doxorubicin and a low dose of all-trans-retinoic acid in MCF-7 breast cancer cell line

The effect of doxorubicin (DOX) used in combination with a low dose (10(-7) M) of all-trans-retinoic acid (tRA) was tested on MCF-7 breast carcinoma cell line. Both drugs are able to inhibit cell proliferation in these cells in a dose-dependent way. The combined treatment with DOX and tRA was more effective in inhibiting cell growth than each of the two compounds alone. This was evidenced in the following experimental conditions: pre-treatments with tRA, for 72 h or 18 h, before DOX incubation; post-treatment with tRA for 18 h after DOX incubation. A consistent synergism was reached by 72 h pre-treatment with tRA and also with brief pre- and post-treatments, but only if tRA was also present during DOX incubation (co-treatments). The mechanisms involved in this interaction between chemotherapeutics and differentiating agents are as yet unclear and should be evaluated further.

Clinical and in vitro response to 13-cis-retinoic acid in interferon-alpha resistant renal cell carcinoma

Retinoids are known to control many important biological processes, including differentiation, morphogenesis, growth and tissue homeostasis. More recently, clinical and pre-clinical results provide evidence for an antiproliferative effect of 13-cis-retinoic acid (13cRA) in interferon-alpha (IFN-alpha) treated renal cell carcinoma patients. The manner in which 13cRA augments antitumor effects and modulates biologic and clinical responses of renal cell carcinoma to IFN-alpha remains elusive. In the present study, we report induction of apoptosis and objective tumor regression in response to 13cRA in advanced renal cell carcinoma patients refractory to IFN-alpha. Among 21 patients treated there were one complete and four partial remissions (objective response rate, 24%; median response duration 8+ months). Preliminary evidence suggests that 13cRA acid may reverse IFN-alpha resistance in renal cell carcinoma.

Clinical pharmacokinetics of tretinoin

Recent reports of the dramatic antitumour effect of tretinoin (all-trans retinoic acid) in patients with acute promyelocytic leukaemia (APL) have generated a great deal of interest in the use of this drug as a chemopreventive and therapeutic agent. However, the biological efficacy of tretinoin is greatly impaired by (presumably) an induced hypercatabolism of the drug leading to reduced tretinoin sensitivity and resistance. Several pharmacokinetic studies have shown that plasma drug exposure [as measured by the plasma area under the concentration-time curve (AUC infinity)] declines substantially and rapidly when the drug is administered in a long term daily tretinoin regimen. These observations led to the hypothesis that the rapid development of acquired clinical resistance to tretinoin may have a pharmacological basis and result from an inability to present an effective drug concentration to the leukaemic cells during continuous treatment. The principal mechanisms proposed to explain the increased disappearance of tretinoin from plasma include: (i) decreased intestinal absorption; (ii) enhanced enzymatic catabolism; and (iii) the induction of cytoplasmic retinoic acid binding proteins (CRABP), which leads to increased drug sequestration. The most favoured explanation is that continuous tretinoin treatment acts to induce drug catabolism by cytochrome P450 (CYP) enzymes. Several strategies aimed at preventing or overcoming induced tretinoin resistance have been, and are being, planned. These strategies include intermittent dose administration, administration of pharmacological inhibitors of CYP oxidative enzymes, combination with interferon-alpha and intravenous administration of liposome-encapsulated tretinoin. As these strategies are now under investigation and the number of patients enrolled is small, further studies are needed to determine the efficacy and toxicity of these new schedules of drug administration. In this article we provide an overview of the relevant aspects of tretinoin physiology and pharmacokinetics, and summarise the current status of knowledge to help in the better optimisation of tretinoin administration.

Effects of all-trans-retinoic acid and 13-cis-retinoic acid on breast-cancer cell lines: growth inhibition and apoptosis induction

Interest has been increasingly focused on all-trans-retinoic acid (tRA) and 13-cis-retinoic acid (13cRA) in cancer chemoprevention and treatment. We have examined the in vitro effects of these 2 retinoic acids (RAs) on human breast-cancer cell lines MCF-7 and ZR-75.1 (both estrogen-receptor-positive, ER+) and MDA-MB-231 (estrogen-receptor-negative, ER-), in terms of inhibition of proliferation and induction of apoptosis. Both retinoic acids exerted an evident dose-dependent growth inhibition, although in the ER- cell line the anti-proliferative effect was obtained only with the highest concentration used; the anti-proliferative activity of tRA was more evident than 13cRA on all 3 tested cell lines. tRA and 13cRA induced apoptosis in MCF-7 and MDA-MB-231 cell lines, but not in ZR-75.1. The apoptotic phenomenon was clearly time-dependent, and in our experience it was not related to the arrest in a specific phase of cell cycle. After treatment with RAs the levels of bcl-2 were reduced in MCF-7, while in ZR-75.1 and in MDA-MB-231 no treatment-related modifications were observed. An analysis of estrogen-receptor status, used as a marker of differentiation, demonstrated that after treatment with RAs the levels of estrogen receptor (ER) decreased in ZR-75.1 only. Our study indicates that the anti-proliferative effects of RAs are sustained by induction of apoptosis in MCF-7 and MDA-MB-231 cells, while in ZR-75.1 cells an induction of differentiation without apoptosis was the prevalent mechanism of growth inhibition. Our results encourage further studies on in vivo effects of these retinoids in breast cancer.

Antiproliferative effects of the arotinoid Ro 40-8757 in human gastrointestinal and pancreatic cancer cell lines: combinations with 5-fluorouracil and interferon-alpha

The arotinoid Ro 40-8757 was previously shown to inhibit the growth of a variety of human cancer cell lines derived from breast, lung and uterus. In view of the high incidence of human digestive cancers, and the slow progress in the development of new therapy, we examined in this paper several combinations between the new arotinoid Ro 40-8757, 5-fluorouracil (5FU) and interferon alpha-2a on the growth of nine human cancer cell lines derived from the gastrointestinal and pancreatic system. Half-maximal inhibition of cell proliferation by Ro 40-8757 was observed at concentrations ranging between 0.18 and 0.57 microM, and increased up to 4.7 microM in retinoid-resistant CAPAN 620 pancreatic cells. All-trans-retinoic acid was 70 times less potent. The sensitivity of HT29-5FU-resistant colonic cells was similar to that observed in the parental cells, suggesting an action independent of pyrimidine metabolism. Ro 40-8757 did not induce any differentiation on HT29 cells, as suggested by ultrastructural analysis. The arotinoid did not interact with receptor signal transduction pathways under the control of serum components, such as growth factors as half-maximal inhibiton of growth was similar in HT29-S-B6 cells cultured in the absence or presence of serum. Cell cycle analysis showed that Ro 40-8757 was not acting at a phase-specific transition in HT29 cells and, accordingly, did not induce overexpression of the protein kinase C (PKC)alpha isoform, or conversion of hyperphosphorylated p105 Rb into hypophosphorylated forms. However, the arotinoid induced significant accumulation of the dephosphorylated, active form of the tumour-suppressor protein. Combinations of Ro 40-8757 with 5FU and interferon alpha 2a resulted in an additive but not synergistic antiproliferative action in HT29 cells. Our data support the interest in Ro 40-8757 as a potent anti-cancer drug, especially in combination therapy with 5FU and interferon, in gastrointestinal and pancreatic cancers, where new active therapeutic modalities are urgently needed.

Cell, tissue and organ culture as in vitro models to study the biology of squamous cell carcinomas of the head and neck

In vitro models are currently being used to study head and neck squamous cell carcinoma (HNSCC). Several hundred HNSCC cell lines have been established by various investigators and used to study a broad spectrum of questions related to head and neck cancer. The head and neck model with respect to multistage carcinogenesis is now complete. Several techniques exist for the culture of normal epithelial cells from the upper aerodigestive tract (UADT). The biology of these UADT cells (oral cavity, oropharynx, hypopharynx and larynx) is being studied. Successful culture of premalignant lesions (dysplastic mucosa, leukoplakia, erythroplakia) has resulted in establishment of a limited number of premalignant cell lines and cell cultures. HPV infection of normal oral epithelial cells for immortalization (approximately premalignant cells) coupled with transformation with carcinogens (malignant cells) has established an experimental model for progression. Two in vivo models for oral carcinogenesis, the 7,12 dimethylbenz(a)anthracene-induced hamster cheek pouch model and the 4-nitroquinoline-N-oxide rat oral model, have been established in culture. Thus, multistage carcinogenesis models have been established from both human tissues and animal models and include cultures of normal, premalignant and malignant cells. Culture techniques for growing dissociated primary tumor cells for short term experimental analysis are being used. The culture of normal or tumor tissue as organ/explant cultures allows for the maintenance of normal cell-cell and cell-matrix interaction, but limits experimentation since these cultures cannot be propagated. Several three dimensional model systems are being used to obtain this histological complexity but allow for experimentation. The ability to culture normal, premalignant and malignant cells coupled with the use of a variety of culture techniques, should allow for the continued growth and experimentation in head and neck cancer research.

Combined effects of 13-cis-retinoic acid, tamoxifen and interferon on the growth of human breast cancer cells

We studied the effect of 13-cis-retinoic acid (13-cRA) alone and in combination with interferons (IFNs) and tamoxifen (TAM) in two established human breast cancer cell lines: the estrogen-sensitive CG-5 and the estrogen-insensitive MDA-MB-453 cells. 13-cRA (10(-9)-10(-5) M) significantly reduced the growth of both cell lines in a dose-dependent fashion, after 3 and 6 days of treatment. When the retinoid (10(-9)-10(-5) M) was combined with natural beta-IFN (100-1000 IU/ml) for 6 days, we observed a growth inhibition more pronounced than that produced by each of the two single agents in both CG-5 and MDA-MB-453 cells. Only in the former model was the inhibitory effect synergistic at all the drug concentrations used. Association of 13-cRA (10(-9)-10(-5) M) and recombinant alpha2a-IFN (100-1000 IU/ml) or TAM (10(-7)-10(-6) M) did not determine an additive or synergistic effect on the growth of CG-5 cells.