Retinoic acid-induced apoptosis and regression of a refractory Epstein-Barr virus-containing T cell lymphoma expressing multidrug-resistance phenotypes

Oral isotretinoin for the treatment of dermatologic conditions other than acne: a systematic review and discussion of future directions

While isotretinoin has been the gold-standard of therapy for severe acne since its approval in 1982, its anti-inflammatory properties makes it a potentially applicable and versatile therapy for a wide variety of dermatologic conditions yet to be explored. This systematic review comprehensively recounts the success of oral isotretinoin in non-acne cutaneous diseases and provide insight into future directions of isotretinoin utility. A systematic literature review was performed using PubMed. Search terms included "isotretinoin" OR "accutane" AND "skin" OR "dermatology" OR "hair" OR "nails" OR "rosacea" OR "psoriasis" OR "pityriasis rubra pilaris" OR "condyloma acuminata" OR "granuloma annulare" OR "darier's disease" OR "non-melanoma skin cancer" OR "frontal fibrosing alopecia" OR "cutaneous lupus erythematosus" OR "hidradenitis suppurativa" OR "photodamaged skin" OR "skin aging" OR "wart" OR "flat warts" OR "plane warts" OR "lichen planus" OR "dissecting cellulitis" OR "folliculitis decalvans" OR "sebaceous hyperplasia" OR "cutaneous t-cell lymphoma" OR "mycosis fungoides." A total of 169 studies discuss the use of oral isotretinoin for 16 non-acne dermatologic conditions, the most common being non-melanoma skin cancers (0.2-8.2 mg/kg/day), cutaneous T-cell lymphomas (0.5-2 mg/kg/day), and rosacea (0.22-1 mg/kg/day). Inflammatory conditions such as rosacea, granuloma annulare, and hidradenitis suppurativa benefit from lower oral isotretinoin dosage of 0.3-1 mg/kg/day, whereas, hyperkeratotic diseases such as psoriasis and pityriasis rubra pilaris, consistently respond better to higher dosages of up to 2-4 mg/kg/day for lesion clearance. Recurrence of disease following discontinuation of isotretinoin have been reported for rosacea, psoriasis, granuloma annulare, Darier's disease, dissecting cellulitis, and non-melanoma skin cancers. Disease exacerbation was reported in some patients with hidradenitis suppurativa. Off-label isotretinoin is an effective treatment choice for dermatological conditions beyond acne. Further prospective, randomized human trials are needed to clarify when and how to prescribe off-label isotretinoin for maximum efficacy and safety.

Glutathione S-transferase π: a potential role in antitumor therapy

Glutathione S-transferase π (GSTπ) is a Phase II metabolic enzyme that is an important facilitator of cellular detoxification. Traditional dogma asserts that GSTπ functions to catalyze glutathione (GSH)-substrate conjunction to preserve the macromolecule upon exposure to oxidative stress, thus defending cells against various toxic compounds. Over the past 20 years, abnormal GSTπ expression has been linked to the occurrence of tumor resistance to chemotherapy drugs, demonstrating that this enzyme possesses functions beyond metabolism. This revelation reveals exciting possibilities in the realm of drug discovery, as GSTπ inhibitors and its prodrugs offer a feasible strategy in designing anticancer drugs with the primary purpose of reversing tumor resistance. In connection with the authors' current research, we provide a review on the biological function of GSTπ and current developments in GSTπ-targeting drugs, as well as the prospects of future strategies.

Stage IV CD30+ anaplastic large cell lymphoma: response to acitretin and interferon-alpha

Retinoids and interferon (IFN)-alpha induce differentiation, affect cell proliferation and alter various immune parameters. In combination, their effects may be additive or even synergistic in the treatment of malignancy. We present a 53-year-old woman with stage IV CD30+ anaplastic large cell lymphoma with brain, lung and skin involvement. The patient had been on methotrexate for rheumatoid arthritis. After a combination of oral acitretin 50 mg daily and IFN-alpha 3 million units subcutaneously 3 times per week, the skin lesions cleared within 2 months, lung lesions by 5 months and brain lesions by 7 months. Although we cannot exclude that methotrexate played a role in the development of this lymphoma and that its withdrawal contributed to the clearance of lesions, we propose that the patient's disease responded to the combination of acitretin and IFN-alpha.

Cyclophosphamide plus somatostatin, bromocriptin, retinoids, melatonin and ACTH in the treatment of low-grade non-Hodgkin's lymphomas at advanced stage: results of a phase II trial

PURPOSE

Somatostatin, prolactin, retinoids, melatonin and ACTH have been shown to influence the lymphatic growth, and the action of the cyclophosphamide in lymphoproliferative disorders is well known. This provided the rationale to conduct, in patients with low-grade non-Hodgkin's lymphomas (NHL), a phase II trial of a combined association of cyclophosphamide, somatostatin, bromocriptin, retinoids, melatonin and ACTH.

PATIENTS AND METHODS

Twenty patients with a diagnosis of low-grade NHL, stage III or IV, were included in this study. Patients received for one month the following treatment: cyclophosphamide, somatostatin, bromocriptin, retinoids, melatonin, and ACTH. The therapy was continued for two additional months in patients with stable or responding disease. After three months, the responding patients continued the therapy for three months and more.

RESULTS

Twenty patients were assessable for toxicity and response; 70% (14 of 20 patients; 95% confidence interval [CI], 50% to 90%) had a partial response; 20% (4 of 20) had stable disease, and 10% (2 of 20) progressed on therapy. Going on with the treatment, none of the 14 patients with partial response had a disease progression (average follow-up time of 21 months, range, 7 to 25), and 50% of these patients had a complete response; among 4 patients with stable disease, 25% (1 of 4) had a partial response and 75% (3 of 4) progressed on therapy (mean time to progression [TTP] 14.3 months, range, 7 to 21). The toxicity was very mild, the most common side effects being drowsiness, diarrhea and hyperglycemia.

CONCLUSIONS

The association of cyclophosphamide, somatostatin, bromocriptin, retinoids, melatonin, and ACTH is well tolerated and effective in treatment of low-grade NHL at advanced stage.

Retinoic acid-induced apoptotic pathway in T-cell lymphoma: Identification of four groups of genes with differential biological functions

Retinoic acid (RA) has been used to induce the regression of refractory T-cell lymphoma. In vitro and in vivo studies have shown that RA exerts this effect through the induction of apoptosis. This study was designed to investigate the molecular pathway of RA-induced apoptosis in T-lymphoma cell lines.RA-induced apoptosis was verified by morphology, flow cytometry, and DNA ladder analysis. Differential display method using a combination of 12 poly(A)-anchored primers and 20 arbitrary primers was adopted for gene cloning. Total RNAs were extracted from H9 cell line at 0, 6, 12, and 24 hours after All-trans RA (ATRA) treatment and the serial expression patterns of the candidate fragments were recognized. The cloned gene fragments were then analyzed and confirmed by Northern blot analysis on H9 and SR786 cell lines.ATRA-induced apoptosis of T-cell lymphoma was protein synthesis-dependent. The execution or irreversible phase of apoptosis appeared to occur at 6-12 hours of RA treatment. Among the 60,000 arbitrarily displayed bands, 25 of 250 candidate fragments were selected for further cloning and sequencing. A total of 14 clones could be matched to known genes and were categorized into four groups: A) transcription factors: prothymosin, CA150, p78 serine/threonine kinase, IL-1beta-stimulating gene, glucocorticoid receptor, MLN64/CAB1, gastrin-binding protein, and polypeptide from glioblastoma; B) chaperone: 90 kDa heat shock protein; C) ion channel: chloride channel protein 3; and D) cytoskeleton: cytovillin2/ezrin and vimentin. Another two clones of genes were of unrecognized functions. The remaining 11 clones belonged to unmatched or novel genes. The expression of these genes varied, either upregulated or downregulated, in response to ATRA treatment.RA-induced apoptosis may involve a cascade of genes that are related to transcription regulation, stress response, housekeeping, and the execution of apoptosis. The clarification of the RA-induced apoptotic pathway will help us to understand the molecular mechanism of cancer differentiation agents.

Release from apoptosis correlates with tumor progression in the AKR lymphoma

Disturbance of apoptosis is an established factor in tumorigenesis. The role of apoptosis in tumor progression is not yet clear. In the present study we compared the tendency to spontaneous apoptosis (and the proliferative capacity) of tumor cells derived from primary (PT) and metastatic tumor (MT) cells of several AKR lymphoma variants. Apoptosis-related gene expression was also compared. Our results indicate that release from apoptosis has a role in the tumor progression of this T cell lymphoma. At the cellular level, a markedly lower apoptotic tendency was observed in MT than in PT cells. The existence of macrophages only in PT also supports the presence of apoptotic cells in local but not in MTs. By contrast, proliferative capacity does not determine tumor aggressiveness in this system. At the molecular level, we found a higher staining intensity for bcl-2 in MT than in PT cells, suggesting that bcl-2 might be responsible for the reduced apoptosis in MT compared to PT cells. Evidence for p53 overexpression was found in the MT cells of one of the variants but in none of the PT. Comparison of Fas receptor, unexpectedly showed an increased expression in MT versus PT cells, possibly indicating resistance to Fas-induced apoptosis in the MT cells.

Priming with G-CSF effectively enhances low-dose Ara-C-induced in vivo apoptosis in myeloid leukemia cells

We investigated the role of apoptosis in chemotherapy for hematologic malignancies. Twelve consecutive patients with acute myelogenous leukemia (AML) or refractory anemia with excess of blasts in transformation (RAEB-t) who were not tolerable for standard-dose chemotherapy were treated with CAG regimen (low-dose cytosine arabinoside [Ara-C] plus aclarubicin with concurrent administration of granulocyte colony-stimulating factor [G-CSF]). Bone marrow mononuclear cells obtained before the commencement of the chemotherapy were cultured with various concentrations (0-10(-5) M) of Ara-C in the presence or absence of 10 ng/mL of G-CSF, and the resultant cell proliferation/cytotoxicity was assayed. In all but one patient, half killing concentration (LC50) of Ara-C was significantly reduced in the presence of G-CSF (by 400- and 1.45-fold, median: 21-fold). Furthermore, LC(50) values in responders assayed in the presence of 10 ng/mL of G-CSF were significantly lower than those in nonresponders (p = 0.02). In vitro killing tests using a G-CSF-dependent leukemic cell line suggested that addition of G-CSF potentiates Ara-C-induced cytotoxicity through the mechanism of apoptosis. We thus assayed apoptosis in peripheral blood leukemic cells during CAG chemotherapy by flow cytometry using 7-amino-actinomycin D. Peak percentages of apoptosis in responders were significantly higher than those in nonresponders (p = 0.02). These results collectively suggest that apoptosis plays an important role for eradicating leukemic cells by CAG chemo-therapy.

Retinoid regulation of interleukin-2 receptors on human T-cells

The ability of retinoids to regulate interleukin-2 receptor (IL-2R) levels on human T-cells may play a fundamental role in the immunomodulating effects of these compounds. As a cell line model for studying this phenomenon, we tested the effects of retinoic acid (RA) on the expression of IL-2Ralpha and IL-2Rbeta in Hut78 cells, a mature T-cell line derived from a Sezary T-cell leukemia. Our results demonstrated 4- to 20-fold increases in the surface expression and mRNA levels of both of these receptor components at RA concentrations starting at 10(-10) M with maximal induction at 1 microM RA. RA-induced upregulation of IL-2Rbeta was found to be transcriptionally mediated in a protein-synthesis-independent fashion; however, activation of the IL-2Rbeta promoter could not be demonstrated in transient transfection experiments utilizing reporter gene constructs containing all currently known regulatory elements of the IL-2Rbeta promoter. Enhancement of IL-2Ralpha/beta by RA was accompanied by upregulation of the expression of CD38, CD69, CD45RO, and HLA-DR, surface molecules known to be associated with T-cell activation. Parallel effects were induced by RA on T-blasts generated from primary human lymphocytes suggesting the physiologic relevance of the Hut78 cell line model. Taken together, our findings demonstrate the ability of RA to upregulate IL-2R expression and enhance the activation state of Hut78 cells. The dramatic enhancing ability of RA on IL-2Rbeta expression does not appear to be mediated through interaction with currently defined regions of the IL-2Rbeta promoter.