Antitumor effects of curcumin in pediatric rhabdomyosarcoma in combination with chemotherapy and phototherapy in vitro.

Rhabdomyosarcoma (RMS), the most common pediatric soft tissue sarcoma, has an unfavorable outcome in advanced tumor stages with less than 30% failure­free survival. Curcumin (CUR) is a promising drug in complementary oncology with few side effects but proven efficacy in various adult oncological entities. The present study analyzed the effects of CUR on pediatric (RMS) cell lines in vitro. RMS cell lines (RD and RH30), and skeletal muscle cells (SKMC) were treated with different doses of CUR (1.5­30 µM) alone, with phototherapy (PDT, 488 nm) or in combination with vincristine (VCR) or dactinomycin (DAC). MTT assays were used for analysis of RMS tumor cell viability. Clonal cell growth was assessed via colony forming assays and migration of the cells was analyzed with scratch tests. Annexin V staining was used to determine apoptosis in flow cytometry. Possible RMS resistance towards CUR after long­term treatment was analyzed with MTT assays. CUR decreased cell viability in all assessed RMS cell lines in a concentration­dependent manner with IC50=14­20 µM. CUR enhanced the effects of the cytotoxic drugs VCR or DAC, and led to reduced migration and increased cell apoptosis. In combination with PDT, CUR decreased the cell viability in minute quantities with up to a 10­fold lower IC50 than without PDT. CUR effectively inhibited the malignant properties of pediatric RMS cells and should be focused on as a useful additional agent in standard chemotherapy of RMS in children.

Análisis de impacto presupuestal de tecnologías para el manejo complementario de quimioterapia en Colombia / Budget impact analysis of technologies for the complementary management of chemotherapy in Colombia

INTRODUCCIÓN: El análisis de impacto presupuestal (AIP) de los medicamentos quimioterapéuticos para el tratamiento de cáncer en Colombia, se desarrolló en el marco del mecanismo técnico científico para la ampliación progresiva del Plan de Beneficios en Salud con cargo a la UPC (PBSUPC) y la definición de la lista de exclusiones, establecido en el artículo 15 de la Ley 1751 de 2015. La quimioterapia tiene un gran impacto en el tratamiento oncológico, la cual es indispensable por su valor terapéutico en varios tipos de cáncer. Esta tecnología puede ser usada sola o junto con otros tratamientos, tales como la cirugía o la radioterapia. La quimioterapia engloba a una gran variedad de fármacos y su objetivo es destruir las células tumorales con el fin de lograr la reducción de la enfermedad, los medicamentos empleados en este tipo de tratamiento se les denomina fármacos antineoplásicos. Cada tipo de tumor canceroso tiene una determinada sensibilidad a estos medicamentos, por lo tanto, es frecuente que el mismo fármaco se pueda emplear en el tratamiento de distintos tumores, variando las dosis o asociándolo a otros fármacos distintos. La quimioterapia puede ser administrada con fines curativos o para aliviar los síntomas y prolongar la supervivencia. La forma de administración de la quimioterapia es por ciclos y esto se logra alternando los periodos de tratamiento con periodos de descanso. Un ciclo es, por lo tanto, el periodo de administración del tratamiento y el de descanso hasta la siguiente administración. El objetivo de este análisis de impacto presupuestal (AIP) es estimar el esfuerzo financiero necesario para la adopción de la quimioterapia en el tratamiento de pacientes con cáncer en Colombia, en un horizonte temporal de tres años. Este documento está conformado por cuatro secciones: en la primera se identifican las tecnologías a evaluar, en la segunda sección se especifica la perspectiva, horizonte temporal y la población sobre la cual se realizó el AIP; en la sección tres se detallan los costos utilizados en el modelo, además de los escenarios planteados por los investigadores; por último, en la sección cuatro se exponen los resultados en los diferentes escenarios planteados Este documento describe la metodología desarrollada para realizar el análisis de impacto presupuestal de 21 tecnologías para el manejo quimioterapéutico del cáncer en Colombia Este informe, sigue los lineamientos propuestos en el Manual para la Elaboración de Análisis de Impacto Presupuestal y en Manual de Participación y Deliberación publicados por IETS. Insumos y método: Esta sección presenta los supuestos, parámetros y métodos utilizados para el modelo de estimación del impacto presupuestal describiendo la siguiente información: Perspectiva: La perspectiva de este AIP es la del tercer pagador el cual en nuestro contexto es el Sistema General de Seguridad Social en Salud (SGSSS). Horizonte temporal: El horizonte temporal de este AIP en el caso base corresponde a un año. Adicionalmente se reportan las estimaciones del impacto presupuestal para los años 2 y 3, bajo el supuesto de inclusión en el PBS en el año 1. Población total: Para el desarrollo de este AIP se parte de la población general afiliada al SGSSS colombiano sin distinción de sexo o edad. ESCENARIOS: Se consideró para la formulación de los escenarios de adopción de las tecnologías evaluadas los siguientes aspectos: 1. Los medicamentos evaluados no son alternativas terapéuticas para las patologías observadas, estas tecnologías sanitarias hacen parte de los protocolos de tratamiento con evidencia científica suficiente que garantizan su efectividad y seguridad clínica y que actualmente se encuentran en las opciones de tratamiento utilizados en la práctica clínica colombiana. 2. Al ser esquemas de tratamiento que hacen parte de protocolos estandarizados de aplicación, sí alguno de los medicamentos es sujeto de recobros ante ADRES, este trámite puede generar barreras de acceso al tratamiento hasta que se efectué la respectiva aprobación. Por lo tanto, no hay certeza de la efectividad clínica si los esquemas de tratamiento son suministrados de forma parcial o incompleta. 3. La elección del esquema de tratamiento obedece a criterios clínicos y a las características evaluadas en el paciente, no se espera una sustitución entre los diferentes esquemas sí se realiza un cambio en el mecanismo de financiamiento. 4. La adopción de las tecnologías evaluadas en este AIP no se espera que se modifiquen de manera importante, debido a que estas tecnologías hacen parte integral de los esquemas de tratamiento y su incorporación en la práctica clínica habitual en el contexto internacional y nacional, data de aproximadamente 10 a 5 años. Tambieén son parte de las opciones de primera línea de tratamiento para estadios tempranos, avanzados y localmente avanzados del paciente diagnosticado con câncer. De acuerdo a las anteriores consideraciones, al incorporar los medicamentos evaluados al PBS con cargo a la UPC, se espera la misma composición del mercado con la adopción de los nuevos medicamentos en el 100% de los tratamientos esperados en la siguiente anualidad. Los resultados esperados en el sistema de salud, en este cambio de financiamiento, se esperan obtener en dos puntos: a) En una mejor oportunidad de acceso a los esquemas de tratamiento en el SGSSS (25). b) En una mejora en la cobertura efectiva de los tratamientos de quimioterapia en pacientes con diagnóstico de cáncer. RESULTADOS: Se muestra el resultado consolidado para las ventiun tecnologías objeto del Análisis de Impacto Presupuestal. La tecnología que genera un mayor impacto es Oxaliplatino, con un valor por persona de $2.363.250,76 usada en 3170 pacientes, para un total de $7.491.504.923,90. El Megestrol es la tecnología con menor impacto, con un costo por persona de $ 383.791,06 y siendo usada en 34 pacientes, tiene un valor total de $ 13.048.896,00. La tretinoina es la tecnología más económica por paciente, con un valor de $ 97.996,50, es usada en 242 personas para un total de $ 23.715.153,00. DISCUSIÓN: En la práctica actual existe un volumen amplio de recobros en el caso de estos medicamentos por usos UNIRS. En algunos casos, los cambios en el mercado farmacéutico, ya sea por el retiro de medicamentos o la llegada de ellos, hace que se modifique indicaciones ya existentes en los registros y que pueden llegar a impactar estos. usos, por ejemplo aquellos casos en los que existe la indicación antineplásico y se cambian por indicaciones especificas, que pueden no considerar condiciones de salud de baja incidencia. Como se ha caracterizado con anterioridad, el mercado de tecnologías sanitarias que se encuentran incluidas al plan de beneficios en salud con cargo a la UPC difiere sustancialmente al mercado de tecnologías sanitarias aún no financiadas por dicho mecanismo. La existencia de las Empresas Administradoras de Planes de Beneficios (EAPB) presume la existencia de un actor que al maximizar su beneficio, es un buen negociador que en cumplimiento de los principios del SGSSS, llega a un precio de equilibrio que maximiza el beneficio social. En cambio, los medicamentos que son sujetos a recobros al ADRES presume un precio fuera de aquel nivel en donde se maximiza al beneficio social, en la medida que no hay una función clara de monopsonio que coteje y negocie un precio de adquisición. En algunos casos puede llegar asumir sobrecostos que las EAPB al ser intermediarias, no tienen incentivos para efectuar un adecuado control. Con el objetivo de estimar el resultado de la incorporación de estos medicamentos al PBS con cargo a la UPC, se asumieron dos escenarios en los cuales la población objetivo del AIP se consideró constante y se asumieron los siguientes supuestos: En el primer escenario se asume que los precios observados en recobros serán el promedio de todas las transacciones de compra en la siguiente anualidad. En el segundo escenario los precios promedio de adquisición de los medicamentos evaluados, corresponden al promedio observado en SISMED como predictor de los precios de equilibrio que pueden generar las EAPB como ente negociador. Se asume que, en promedio, las EAPB son negociadores eficientes que se acercan a un precio de equilibrio que maximiza el bienestar social. Se asume que la población objetivo corresponde al total de posibles pacientes que requieren las tecnologías sanitarias en evaluación, sin que exista demanda insatisfecha para estos esquemas de tratamiento. Para su cálculo, como se presenta en la tabla 09 de los servicios prestados durante el año 2015 y recobrados al FOSYGA en los años 2015 y 2016, se calculó un valor per-cápita de acuerdo con el identificador (cedula de ciudadanía anonimizada) registrado en cada recobro. Luego, este valor es indexado a precios 2016 con el IPC reportado por el DANE a diciembre 31 del año 2015. Este valor será el comparador del precio calculado para cada uno de los medicamentos a partir de SISMED 2016.

Gestational trophoblastic disease II: classification and management of gestational trophoblastic neoplasia.

Gestational trophoblastic neoplasia (GTN) includes invasive mole, choriocarcinoma, placental site trophoblastic tumor, and epithelioid trophoblastic tumor. The overall cure rate in treating these tumors is currently >90%. Thorough evaluation and staging allow selection of appropriate therapy that maximizes chances for cure while minimizing toxicity. Nonmetastatic (stage I) and low-risk metastatic (stages II and III, score <7) GTN can be treated with single-agent chemotherapy resulting in a survival rate approaching 100%. High-risk GTN (stages II-IV, score ≥7) requires initial multiagent chemotherapy with or without adjuvant radiation and surgery to achieve a survival rate of 80-90%.

30 years' experience in the treatment of low-risk gestational trophoblastic neoplasia in Hungary.

OBJECTIVE: To review the clinical experience in the treatment of patients with low-risk gestational trophoblastic neoplasia (GTN) over the past 30 years in a national trophoblastic disease center. STUDY DESIGN: Between January 1, 1977, and December 31, 2007, 302 patients with low-risk GTN were treated. The patients were directed to our institution from all parts of Hungary. The patients were 14 to 53 years of age with an average age of 28.3 years. Methotrexate (MTX)/folinic acid or actinomycin-D (Act-D) primary chemotherapy was selected based upon the patient's stage and prognostic score of GTN. RESULTS: Among 218 low-risk patients, 210 (96.3%) achieved remission as a result of MTX therapy. In 8 patients (3.7%), MTX-Act-D-cyclophosphamide (MAC) combination chemotherapy was needed to achieve complete remission, in some cases assisted by operation. Among 84 patients, 81 (96.4%) achieved remission as a result of Act-D therapy. In 3 cases (3.6%) complete remission was achieved by MAC combination chemotherapy. We detected metastases in 22.8% (69/302) of our low-risk patients. Chemotherapy, surgical intervention or other supplementary treatments resulted in 100% remission in cases of low-risk nonmetastatic and metastatic disease. CONCLUSION: Our data indicate that MTX/folinic acid or Act-D should be the primary treatment in patients with nonmetastatic or metastatic low-risk GTN. Importantly, patients with resistance to single-agent chemotherapy regularly achieve complete remission with MAC combination chemotherapy. Results show that patient care under the direction of experienced clinicians serves to optimize the opportunity for cure and minimize morbidity.

Isolated limb infusion with melphalan and actinomycin D in melanoma patients: factors predictive of acute regional toxicity.

IMPORTANCE OF THE FIELD: Isolated limb infusion (ILI) is a simple, minimally invasive technique of delivering high concentrations of cytotoxic drugs to a diseased limb for achieving disease control in that limb. Recent studies have suggested that mild hyperthermic (38 degrees C) ILI might be the best initial treatment for extensively recurrent limb melanoma given its simplicity, low morbidity and a complete response rate of 30 - 40%. AREAS COVERED IN THIS REVIEW: Since 1994 when ILI was first described by Thompson et al., the procedure has been adopted by several centres around the world; research and improvements in the technique have resulted in reduction in limb toxicity without reducing its clinical efficacy. The pharmacokinetics of melphalan and the clinical efficacy and adverse effects of ILI from various centres are summarised. Minor but possibly important differences in the ILI techniques used in different institutions may be important in improving its efficacy and reducing the toxic effects. WHAT THE READER WILL GAIN: An understanding of the efficacy and toxicity associated with ILI with cytotoxic drugs in melanoma patients and of methods to optimise regional therapy for malignant disease in a limb. TAKE HOME MESSAGE: ILI with mild hyperthermia (38 degrees C) is well tolerated with tumour remission rates in melanoma patients similar to those achieved by isolated limb perfusion. Mild (grade I - II) and moderate/severe (grade > or = III) limb toxicities occur in 58 - 68% and 32 - 41% of patients, respectively, but long-term morbidity is rare. A high peak and high final melphalan concentration in the infusate, the AUC of melphalan concentration in the infusate and an increased postoperative serum creatine phosphokinase concentration are factors predictive of acute regional toxicity. Drug dose adjusted for ideal body weight and gender may reduce acute toxicity following ILI. It has been suggested that the use of papaverine prior to the infusion of melphalan might increase its efficacy, but it may also increase toxicity. Large prospective studies are needed to more accurately define the perioperative factors that influence acute regional toxicity after ILI and to establish strategies to optimise clinical outcome.

Wogonin sensitizes resistant malignant cells to TNFalpha- and TRAIL-induced apoptosis.

TNFalpha has previously been used in anticancer therapy. However, the therapeutic application of TNFalpha was largely limited due to its general toxicity and the fact that it activates the NF-kappaB-family transcription factors, which are proinflammatory and antiapoptotic. To overcome this problem in vitro, specific NF-kappaB inhibitors or transcription or protein synthesis inhibitors such as actinomycin D and cycloheximide are usually used in combination to increase TNFalpha killing of tumor cells. However, these agents also cause harmful side effects in vivo. We show here that wogonin, derived from the popular Chinese herb Huang-Qin, attenuates NF-kappaB activity by shifting TNFalpha-induced free radical .O(2)(-) to a more reduced nonradical product, H(2)O(2), and thereby sensitizes TNFalpha-resistant leukemia cells to TNFalpha-induced apoptosis. Importantly, wogonin does not affect the viability of normal peripheral blood T cells. Wogonin also sensitizes TRAIL-induced apoptosis. Our data suggest a potential use of wogonin as a TNFalpha or TRAIL adjuvant for cancer treatment. Our data also demonstrate how a herbal compound enhances killing of tumor cells with reduced side effects compared with other treatments.

Treatment of refractory chromomycosis by isolated limb infusion with melphalan and actinomycin D.

BACKGROUND: Chromomycosis is frequently resistant to systemic and local therapies, and advanced bulky disease can compromise limb function. METHODS: A man developed extensive chromomycosis of the left arm, refractory to multiple systemic and local treatments. Regional chemotherapy with the isolated limb infusion (ILI) technique using melphalan and actinomycin D markedly reduced disease bulk and greatly improved function of the arm over the next 2 months. Repeat ILI was performed 10 months later, again with good improvement in mobility of the elbow and significant debulking of disease. At the present time, there is some persistent but stable disease, which is controlled by heat therapy with disposable pocket warmers. The patient declined any further systemic therapy. CONCLUSION: ILI rapidly reduced disease bulk, restoring the limb to normal function within a few weeks. Although not curative, ILI could be an effective adjunctive treatment for severe chromomycosis in patients resistant to or intolerant of other therapies.

Sensitization of human colon cancer cells to TRAIL-mediated apoptosis.

TNF-related apoptosis-inducing ligand (TRAIL), a novel member of the tumor necrosis factor (TNF) family, is thought to induce apoptosis preferentially in cancer cells; however, increasing evidence suggests that a number of cancers are resistant to TRAIL treatment. FLICE-like inhibitory protein (FLIP), which structurally resembles caspase-8, can act as an inhibitor of apoptosis when expressed at high levels in certain cancer cells. The purpose of our present study was to determine whether human colon cancer cells are sensitive to TRAIL treatment and, if not, to identify potential mechanisms of resistance. Colon cancer cells of different metastatic potential (KM12C, KML4A, and KM20) were found to be resistant to the effects of TRAIL when used as a single agent. FLIP expression levels were increased in all three KM cell lines. Treatment with either actinomycin D (Act D;10 :g/ml) or cycloheximide (CHX; 10 :g/ml) decreased FLIP expression levels in all three cell lines. The decrease in cellular levels of FLIP was associated with sensitization to TRAIL-mediated apoptosis, as demonstrated by enhanced cell death and caspase-3 activity compared with either Act D or CHX alone. Our findings suggest that reduction of FLIP levels by Act D or CHX renders TRAIL-resistant human colon cancer cells sensitive to TRAIL-mediated apoptosis. The combination of TRAIL along with agents such as Act D or CHX, which target proteins that prevent cell death, may provide a more effective and less toxic regimen for treatment of resistant colon cancers.

Management of high-risk gestational trophoblastic disease.

Multimodality therapy with combination chemotherapy employing etoposide, high-dose methotrexate, actinomycin D, cyclophosphamide and vincristine (EMA-CO), and adjuvant radiotherapy and surgery, when indicated, has resulted in cure rates of 80-90% in patients with high-risk metastatic gestational trophoblastic tumors. However, approximately 25-30% of high-risk patients will have an incomplete response to first-time chemotherapy or will relapse from remission. Most of these patients will have a clinicopathologic diagnosis of choriocarcinoma, metastases to sites other than the lung and vagina, more than eight metastases and/or failed inappropriate previous chemotherapy, resulting in very high World Health Organization scores. Salvage chemotherapy with cisplatin/etoposide, usually in conjunction with bleomycin or ifosfamide, as well as surgical resection of sites of resistant disease in selected patients, will result in a cure in most patients. New technology, such as the use of colony-stimulating factors to prevent treatment delays and dose reductions or high-dose chemotherapy with or without autologous bone marrow transplantation or peripheral blood stem cell support, may play an important role in the future management of patients who develop drug resistance.

Inhibition by actinomycin D of neurogenic mouse ear oedema.

We have investigated the effects of actinomycin D on mouse ear oedema induced by capsaicin, neuropeptides, and established inflammatory mediators. Actinomycin D (0.5 mg/kg, i.v.) significantly (P < 0.01) inhibited ear oedema induced by topical application of capsaicin, while adriamycin (6.0 mg/kg, i.v.) and cycloheximide (6.0 mg/kg, i.v.) had no effect on oedema. The ear oedema induced by intradermal injection of neuropeptides such as mammalian tachykinins, calcitonin gene-related peptide (CGRP), and vasoactive intestinal peptide (VIP), was markedly (P < 0.05, P < 0.01 or P < 0.001) suppressed by actinomycin D. The drug was also effective (P < 0.01 or P < 0.001) in inhibiting bradykinin (BK)- and compound 48/80-induced ear oedema, but did not inhibit oedema induced by histamine, 5-HT, leukotriene C4 (LTC4), and platelet activating factor (PAF) at a dose of 1 mg/kg. In mast cell-deficient W/WV mice, actinomycin D (1.0 mg/kg, i.v.) failed to inhibit substance P (SP)-induced ear oedema whereas spantide (0.5 mg/kg, i.v.) was an effective (P < 0.01) inhibitor of oedema formation. Furthermore, actinomycin D (10-100 microM) dose-dependently prevented histamine release from rat peritoneal mast cells evoked by SP, compound 48/80, and the ionophore A23182, respectively. These results strongly suggest that an inhibitory effect of actinomycin D on neurogenic inflammation is due primarily to the prevention of mast cell activation mediated by neuropeptides, rather than an interaction with DNA or receptors of neuropeptides.

Safe, compact and portable system for regional chemotherapeutic hyperthermic perfusion procedures.

Perfusion techniques utilizing hyperthermic chemotherapy have been established as a successful modality of therapy for isolated metastatic malignant melanoma. The combination of chemotherapeutic agents (Dactinomycin, thiotepa and Mechlorethamine HCl) given in high doses, not possible systemically, combined with hyperthermia (40-42 degrees C) in an isolated extremity has shown greater tumor regression compared with systemic medication only. Many of the isolated limb perfusion procedures are performed in non-cardiac centers, especially at specialized cancer institutions. This often presents new obstacles for the perfusionist including lack of adequate perfusion equipment and disposables. Other obstacles include unfamiliarity of the operating room staff with the heart-lung machine and inappropriate and/or unsafe handling of the perfusion circuit. In order to overcome these obstacles and enhance safety, portability and effectiveness, the authors have developed an isolated limb perfusion system. The purpose of this study was to compare the parameters of treatment and long term outcomes demonstrated by our system and method, to previously published data. The qualitative comparative analysis was performed between eight treatments with this type of perfusion system and outcome data previously published. It is the authors' conclusion that the portable isolated limb perfusion system achieved all of the required parameters to provide safe and effective treatment for this type of melanoma. No demonstrated variation of the long term clinical results in our patient population was seen when compared to previously published data.

Circumvention of pleiotropic drug resistance in subcutaneous tumours in vivo with verapamil and clomipramine.

The development of pleiotropic drug resistance (PDR) in vivo in solid tumour models suggests that a similar process may occur in the clinic. A subline of the Ridgway osteogenic sarcoma (ROS)--a murine subcutaneously-growing solid tumour--with moderate resistance (1.5 fold) to actinomycin D was selected by repeated suboptimal treatment with this drug in vivo. This subline (ROS/ADX/G2) showed cross-resistance to vincristine (3.5 fold) and etoposide (over 5.1 fold) but not to doxorubicin. The resistance could in all cases be partly or completely overcome by treatment with non-cytotoxic doses of verapamil or clomipramine. Resistance to actinomycin in this model was associated with lower (up to 3.2 fold) drug accumulation into tumours which could be increased (up to 2.8 fold) by treatment with 25 micrograms/g verapamil. These data support clinical trials of the use of membrane-active agents to overcome PDR.

Cytocidal activity of a synthetic isoprenoid, N-solanesyl-N,N'-bis(3,4-dimethoxybenzyl)ethylenediamine, and its potentiation of antitumor drugs against multidrug-resistant and sensitive cells in vitro.

A synthetic isoprenoid, N-solanesyl-N,N'-bis(3,4-dimethoxybenzyl)ethylenediamine (SDB-ethylenediamine), inhibited the colony formation of multidrug-resistant mutant cell lines derived from Chinese hamster V79 (V79/ADM) and human hepatoma PLC/PRF/5 (PLC/COL) cells to a greater extent than that of the parental cells. When combined with other clinically useful antitumor agents, it potentiated the cytotoxic activity of almost all kinds of drugs tested including adriamycin (ADM), actinomycin D, vincristine, cytosine arabinoside, and 5-fluorouracil (5-FU), and the potentiation ratios were higher against V79/ADM cells than against V79/S cells. Among the antitumor agents tested, the activities of bleomycin-group antibiotics were more strongly enhanced by SDB-ethylenediamine and the potentiation was higher in the parental cells than in V79/ADM cells. SDB-ethylenediamine enhanced the uptake of ADM and daunorubicin into V79/ADM and its parental cells, but it did not increase the uptake of 5-FU or peplomycin, indicating that different mechanisms operate for potentiation in the cases of the latter drugs, i.e., not simply an increase of intracellular drug uptake. Two fragments of SDB-ethylenediamine, solanesol (polyprenoid moiety) and the diamine component (verapamil-like moiety), showed neither cytotoxic activity nor potentiator activity, even if they were mixed together, indicating that the steric conformation of intact SDB-ethylenediamine molecule is important for these two activities.

Potentiation of vincristine and actinomycin D by a new synthetic imidazole anti-tumor agent YM534 active against human cancer cells and multidrug-resistant cells.

Ethyl 6-p-5-(l-imidazolyl) pentyloxyphenoxy-2, 2-dimethylhexanoate hydrochloride (YM534) is a new synthetic anti-tumor compound. Combinations of YM534 with other anti-cancer agents were examined to ascertain whether YM534 potentiated other anti-cancer agents against the KB cell line and its multidrug-resistant counterpart, VJ-300. YM534 potentiated the cytotoxic action of vincristine and actinomycin D about 2-fold against KB cells, but not those of daunomycin and adriamycin. By contrast, YM534 only slightly reversed drug-resistance to adriamycin and daunomycin in VJ-300 while it reversed 5-fold vincristine resistance and 60-fold actinomycin D resistance in VJ-300. The reversal effect of YM534 on actinomycin D and vincristine-resistance in VJ-300 cells appeared to be due to enhanced accumulation of [3H] actinomycin D and [3H] vincristine in VJ-300 cells by YM534. YM534 inhibited efflux of actinomycin D and vincristine from VJ-300 cells, and it also enhanced cellular uptake of these anti-cancer agents. YM534 enhanced cellular accumulation of both actinomycin D and vincristine in the sensitive KB cells. YM534 is thus a unique anti-cancer agent since combinations of other anti-cancer agents with YM534 are expected to augment anti-tumor activity of them. By contrast, YM212, a carboxy analog of YM534, had much less activity to potentiate vincristine and actinomycin D). YM534 at 100-1000 microM almost completely inhibited the photoaffinity labeling of [3H] azidopine to the 170-kD P-glycoprotein of VJ-300 cell membranes, but YM212 showed much less inhibitory action on the photoaffinity labeling. YM534 could also inhibit the photoaffinity labeling of deglycosylated P-glycoprotein.

A new antitumor antibiotic, chounghwamycin A. I. Taxonomy, isolation and characterization.

Chounghwamycin A, a new antitumor antibiotic produced by a strain of Streptomyces sp. No. PL-D-5, was isolated and characterized. It appeared to belong to the actinomycin group of antibiotics from physico-chemical studies and has an empirical formula of C63H88N11O21. The antibiotic is extractable into an organic solvent from the fermentation broth, possessing potent antileukemic activity against P388 mouse leukemia in mice and antimicrobial activity against Gram-positive bacteria with MIC values about 0.1-0.4 microgram/ml, but showed no activity on Gram-negative bacteria, yeast and fungi tested.

[Effect of androgens on the development of leukemia in AKR-strain mice]. / Vliianie androgenov na razvitie leikoza u myshei linii AKR.

A possibility of the androgen's correction of spontaneous and transplanted leukogenesis has been investigated in AKR mice. Prolongation of life was observed in the animals treated with the hormone at early stages of the leukemia development. The obtained results may be related to the stem hemopoietic precursors differentiation change under the testosterone influence manifested by erythropoiesis stimulation and the reduction of granulocytic colonies determined by the growth in the cellulose-acetate membranes (CFUcam).

Screening for induction of differentiation and toxicity to blast cells by chemotherapeutic compounds in human myeloid leukemia.

Bone marrow cells from 9 patients with acute myeloid leukemia and 1 patient with a blast crisis of chronic myeloid leukemia were cultured to determine their ability to be induced to differentiate by different chemotherapeutic compounds. Five of these 10 patients showed differentiation to granulocytic and/or monocytic cells by culture with medium containing the myeloid cell differentiation-inducing protein MGI-2. Actinomycin D induced differentiation in cells from 2 of the patients who did not show differentiation with MGI-2 containing medium. In these 7 patients there was an increase in the ratio of differentiated myeloid cells to blasts. None of these 10 patients showed induction of differentiation by cytosine arabinoside, adriamycin, or daunomycin, but treatment with these compounds showed in some patients an increase in the ratio of differentiated myeloid cells to blasts. The results indicate that this ratio can be increased by differentiation and also in some patients by toxicity to blast cells. With dexamethasone or vinblastine there was no induction of differentiation and no increase in this ratio in any of the 10 patients tested. After in vivo chemotherapy with low dose cytosine arabinoside, cells from one patient showed a similar response in culture to actinomycin D as cells before chemotherapy, whereas in another patient the cells had acquired the ability to respond to actinomycin D. In contrast, after high-dose in vivo chemotherapy with cytosine arabinoside and daunomycin, cells from a third patient seemed to have lost the ability to differentiate in vitro by MGI-2 containing medium or actinomycin D. The results indicate that pre-screening for differentiation-inducing compounds and compounds that show toxicity to blast cells should be useful to select the appropriate compounds to be used for therapy, and that it is advisable to screen the cells both before and after initiation of therapy.

[Inhibitor interaction in the suppression of ribosomal RNA synthesis in Ehrlich ascites carcinoma cells]. / Vzaimodeistvie ingibitorov pri podavlenii sinteza ribosomnoi RNK v kletkakh astsitnoi kartsinomy Erlikha.

Kinetic analysis of inhibitory action of papaverine, 2,4-dinitrophenol (DNP) and actinomycin D on RNA synthesis in the intact Ehrlich ascites carcinoma cells has shown that the action of these agents is mediated by their effect on the same step of rRNA synthesis.

An update on the anticancer effects of a combination of chemotherapy and hyperthermia.

Hyperthermia combined with chemotherapy is a complicated and poorly understood area, but one that portends great biological and clinical interest. The interrelationship of heat to vascular supply of tumor and normal organs that metabolize chemotherapy agents is complicated. The evocation of thermotolerance by chemical agents is a largely unexplored area. A class of chemotherapy agents that increase in cytotoxicity linearly with increasing temperature are the alkylating agents cisplatinum, mitomycin C, and mitoxantrone. A class of chemotherapy agents that increase in cytotoxicity only after a threshold temperature above 42 degrees are Adriamycin, bleomycin, and actinomycin D. Time sequencing of heat and Adriamycin affects cytotoxicity, implying a membrane effect of the heat and drug interaction. A new class of drugs thought not to be chemotherapy drugs because they are not cytotoxic at 37 degrees but are cytotoxic at greater than 41.5 degrees provides a new area of research. Chemotherapy agents that do not change in cytotoxicity with heat include the Vinca alkaloids, amsacrine, and 5-fluorouracil. In order to examine the complex interaction of heat and chemotherapy agents, whole animal models of tumor and normal tissue effects are extremely important.

New possibilities of cytostatic drug testing on patient tumor cells by flow cytometry.

A new assay for cytostatic drug testing is described which can be automated. Pleural effusions and ascites are cultured as such for one week. Cells of solid tumors are cultured in the patients own serum for the same time. The cells are then stained with the esterase and intracellular pH-indicator dye 1,4-diacetoxy-2,3-dicyano-benzene (ADB) to label vital cells. They are simultaneously stained with propidium iodide (PI) as an indicator for dead cells. Monosized fluorescent latex particles are added as concentration, volume and fluorescence standard. Inflammatory cells can be distinguished in the assay from tumor cells because of their small cell volume. The number of dead and surviving cells is counted by the flow cytometer and a therapeutic index is calculated as ratio between the surviving inflammatory to surviving tumor cells. An important feature of the assay is that the DNA-distribution of the dead cells (e.g. aneuploidy) as well as the functional state of the surviving tumor cells and inflammatory cells can be judged from intracellular esterase activity and intracellular pH.