Combination Of Cytostatic Drugs Research Articles

Perspectives of Cell Sensitivity/Resistance Assay in Soft Tissue Sarcomas Chemotherapy.

Treatment of highly malignant soft tissue sarcomas (STSs) requires multicomponent therapy including surgery, radiotherapy, and chemotherapy. Despite the advancements in targeted cancer therapies, cytostatic drug combinations remain the gold standard for STS chemotherapy. The lack of algorithms for personalized selection of STS chemotherapy leads to unhelpful treatment of chemoresistant tumors, causing severe side effects in patients. The goal of our study is to assess the applicability of in vitro chemosensitivity/resistance assays (CSRAs) in predicting STS chemoresistance. Primary cell cultures were obtained from 148 surgery samples using enzymatic and mechanical disaggregation. CSRA was performed using resazurin-based metabolic activity measurement in cells cultured with doxorubicin, ifosfamide, their combination and docetaxel, gemcitabine, and also their combination for 7 days. Both the clinical data of patients and the CSRA results demonstrated a higher resistance of some cancer histotypes to specific drugs and their combinations. The correlation between the CSRA results for doxorubicin and ifosfamide and clinical responses to the combination chemotherapy with these drugs was demonstrated via Spearman rank order correlation. Statistically significant differences in recurrence-free survival were also shown for the groups of patients formed, according to the CSRA results. Thus, CSRAs may help both practicing physicians to avoid harmful and useless treatment, and researchers to study new resistance markers and to develop new STS drugs.

Abstract A032: Targeting pancreatic cancer senescence with ImmunoPET

Abstract Pancreatic cancer is the fourth leading cause of cancer-related deaths for men and women, with five-year overall survival rates around 10 percent. Despite years of cancer research and new immunotherapy solutions, pancreatic cancer is still mainly treated by chemotherapies, starting with gemcitabine. Many cytostatic drug combinations have been shown, in a wide range of cancers, to induce senescence, a persistent, anti-apoptotic process characterized almost exclusively by beta galactosidase activity. Studies inducing senescence with the combination of trametinib and palbociclib (TP) have linked several tumorigenic and pro-metastatic factors in murine pancreatic cancer models to the senescence-associated secretory profile (SASP), giving rise to new antigen targets during the induction of senescence. Accordingly, senescence has recently been elevated as a new hallmark of cancer. There is thus a critical need for antigen-based tools to noninvasively identify markers of senescence in vivo. Senescence targets comprise of shed antigens (VEGF and IL-6) in the context of senescence-inducing therapy with trametinib and palbociclib (TP), when membrane bounds targets such as urokinase plasminogen activated receptor (uPAR) are potentially enriched. We show that VEGF and IL-6 targeting antibodies labeled with zirconium-89 deferoxamine (89Zr-DFO) bind cells treated with TP though in vivo, marked reduction in tumor targeting is seen. Preloading and targeting antigen shed are being actively considered as alternative imaging approaches. For membrane bound antigens associated with senescence, here we report the latest work developing uPAR immunoPET agents. First, we have shown that attachment of 89Zr-DFO preserves the binding function of both murine (muPAR) and human uPAR (huPAR) antibodies with high cross-reactivity of the murine uPAR (muPAR) antibody with huPAR. Cell uptake was increased two-fold in murine KPC cells with senescence-inducing TP treatment. In vivo, accumulation in subcutaneously implanted murine KPC pancreatic tumors was observed with TP-treated mice; however lower liver and blood activity was imaged by PET/CT and confirmed by terminal biodistribution at 144h. Human uPAR-targeting antibody in nude mice bearing flank MiaPaCa2 tumors showed strong antibody uptake by 144 h, with increased tumor uptake for mice undergoing TP therapy. Preloading studies at 10 µg, 40 µg, and 100µg at 4h prior to injection of 40µg 89Zr-DFO-huPAR showed improved tumor uptake kinetics with the highest preloading level, though overall tumor uptake was decreased at the higher radiolabeled antibody dose used, thus more optimization is needed. The development and optimization of 89Zr-DFO-uPAR antibodies for human and murine targets provides a superior means of identifying pancreatic cancer and pancreatic cancer senescence than that afforded by shed antigens. Future directions include further dose optimization and testing uptake in other pancreatic models, senescence-inducing drug combinations, and possible antibody-conjugated senolytic or endoradiotherapy strategies. Citation Format: Edwin C. Pratt, Riccardo Mezzadra, Tara Viray, Spencer Kaminsky, Scott W. Lowe, Jason S. Lewis. Targeting pancreatic cancer senescence with ImmunoPET [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A032.

Synergistic Antitumor Interaction of Risedronate Sodium and Standard Anticancer Agents in Canine (D-17) and Human Osteosarcoma (U-2 OS) Cell Lines.

Simple SummaryThe study investigated canine (D-17) and human (U-2 OS) osteosarcoma exposition to risedronate sodium and chosen standard anticancer drugs concurrently used in vitro. Risedronate sodium is frequently used in the therapy of bone tissue disorders. Our study demonstrated increased efficiency of cytostatic drugs in the presence of risedronate. During the incubation, testing and evaluation the standard protocols were used. MTT and TUNEL assays were employed to estimate changes in cell viability and percentage of apoptosis. We found that a combination of doxorubicin and cisplatin with risedronate sodium produced the strongest cytotoxic effects in both cell cultures. The cytotoxicity against both types of osteosarcoma was concentration-dependent and the cytostatic drugs and risedronate sodium were found to act synergistically.The study discusses in vitro cytotoxicity of a combination of cytostatic drugs (doxorubicin, cisplatin, carboplatin, etoposide) and risedronate sodium against canine and human osteosarcoma (D-17 and U-2 OS). Standard protocols were used for the preparation of cell cultures and evaluation of their viability and apoptosis. MTT assay assessed the culture viability and EC50, while the apoptotic effect of the drugs was checked with a TUNEL assay. Doxorubicin alone showed the strongest cytotoxicity against D-17 (0.056 ± 0.019 µg/mL) and U-2 OS (0.051 ± 0.003 µg/mL), while the lowest cytotoxicity was observed for carboplatin (D-17, 6.45 ± 0.2 µg/mL and U2-OS, 27.5 ± 2.3 µg/mL). Risedronate sodium at 100, 10 and 1 µg/mL lowered viability in OS cell lines by 53.38 ± 1.46 and 49.56 ± 0.7%, 97.08 ± 3.32 and 74.92 ± 4.01%, and 102.67 ± 3.56 and 94.56 ± 3.52%, respectively. In all analyzed drug combinations, risedronate sodium significantly (* p < 0.05) increased the cytotoxicity against tested osteosarcoma cell lines. The decrease in cell viability caused by the studied compound combinations was weaker in canine than in human cell cultures. A combination of doxorubicin (all concentrations), cisplatin (1 µg/mL) and etoposide (1 µg/mL) with 100 µg/mL of risedronate sodium significantly improved the cytotoxicity of the drugs against canine and human osteosarcoma. Administration of carboplatin (1 µg/mL) and risedronate sodium (100 µg/mL), compared to carboplatin per se, produced no significant differences in cytotoxicity against the D-17 cell culture but significantly enhanced cytotoxicity in the U-2 OS line. The strongest apoptosis in both lines was detected for 0.01 µg/mL doxorubicin combined with 100 µg/mL risedronate sodium or 1 µg/mL cisplatin and 100 µg/mL risedronate sodium. In all combinations, the tested compounds revealed a synergistic mechanism of action.

Proimmunogenic impact of MEK inhibition synergizes with agonist anti-CD40 immunostimulatory antibodies in tumor therapy

Cancer types with lower mutational load and a non-permissive tumor microenvironment are intrinsically resistant to immune checkpoint blockade. While the combination of cytostatic drugs and immunostimulatory antibodies constitutes an attractive concept for overcoming this refractoriness, suppression of immune cell function by cytostatic drugs may limit therapeutic efficacy. Here we show that targeted inhibition of mitogen-activated protein kinase (MAPK) kinase (MEK) does not impair dendritic cell-mediated T cell priming and activation. Accordingly, combining MEK inhibitors (MEKi) with agonist antibodies (Abs) targeting the immunostimulatory CD40 receptor results in potent synergistic antitumor efficacy. Detailed analysis of the mechanism of action of MEKi shows that this drug exerts multiple pro-immunogenic effects, including the suppression of M2-type macrophages, myeloid derived suppressor cells and T-regulatory cells. The combination of MEK inhibition with agonist anti-CD40 Ab is therefore a promising therapeutic concept, especially for the treatment of mutant Kras-driven tumors such as pancreatic ductal adenocarcinoma.

PB1995 THE EFFECTS OF ANTITUMOR THERAPY ON BONE REMODELING IN PATIENTS WITH HODGKIN'S LYMPHOMA

Background:Cures have been achieved in a significant proportion of patients with Hodgkin lymphoma (HL) for many years. Treatment for HL has been associated with adverse late effects. One of those consequences of antitumor therapy may be a change in bone mineral density (BMD). Hemoblastosis is considered as a strong risk factor for secondary osteoporosis and major low‐energy fractures. The decrease in BMD can be associated with polychemotherapy, including various combinations of cytostatic drugs and glucocorticoids, as well as with hypogonadism caused by toxic effects of radiotherapy and chemotherapy, tumor process, low physical activity and other factors.Aims:To assess the bone mineral density (BMD) in patients with HL.Methods:The study included 103 patients with HL from the City Hematology Center of Novosibirsk, from 19 to 72 years of age (median 49 years [33;55]). The disease was staged according to the Ann Arbor staging system: 55 patients had early stage disease and 48 patients had advanced stage disease (stage III to IV). All subjects received first‐line regimens (ABVD, BEACOPP‐14, et al.). Eighteen patients with advanced stages and unfavorable prognosis obtained second‐line regimens (DHAP, ESHAP). Radiotherapy was performed in 57 (55,3%) individuals. Complete remission was achieved in 60 of 103 patients (58,2%), and partial remission was recorded in 32 ones (31%). The BMD was assessed by dual‐energy X‐ray absorptiometry with GE Lunar Prodigy densitometer (USA). The assessed variables were BMD and T‐ or Z‐criterion (when appropriate) at the lumbar spine (L1–L4), proximal femur, femoral neck and forearm of a non‐dominant arm. Fracture Risk Assessment Tool (WHO FRAX, web version 3.8, adjusted for Russia) was used to determine the risk of major osteoporotic fractures.Results:The decreased BMD was revealed in 47 observed HL subjects (45,6%), 30 of them diagnosed osteoporosis. The decline in BMD was more frequent in patients aged ≥50 years as compared to younger ones (χ2 = 5,75; p = 0,02). More patients with radiotherapy in anamnesis had decreased BMD compared to patients who received chemotherapy only (χ2 = 8,82; p = 0,003) More than half of the patients (60 %) receiving regimens containing glucocorticosteroids had BMD decrease. Based on FRAX assessment, the 10‐year risk of major low‐energy fractures and the hip fractures was expectedly higher in patients with osteoporosis and osteopenia as compared to subjects with normal BMD (p &lt; 0,05). A comparative analysis revealed that patients younger than 50 years old had more often lower values of BMD and Z‐score of the lumbar spine. In turn, the femoral neck was the most frequent localization of osteoporosis in patients older 50 years and postmenopausal women.Summary/Conclusion:The study demonstrates high prevalence of decreased BMD in patients with HL. The decrease in BMD is associated with radiotherapy and chemotherapy with glucocorticoids.

NK cell-mediated cytotoxicity contributes to tumor control by a cytostatic drug combination.

Molecularly targeted therapies aim to obstruct cell autonomous programs required for tumor growth. We show that mitogen-activated protein kinase (MAPK) and cyclin-dependent kinase 4/6 inhibitors act in combination to suppress the proliferation of KRAS-mutant lung cancer cells while simultaneously provoking a natural killer (NK) cell surveillance program leading to tumor cell death. The drug combination, but neither agent alone, promotes retinoblastoma (RB) protein-mediated cellular senescence and activation of the immunomodulatory senescence-associated secretory phenotype (SASP). SASP components tumor necrosis factor-α and intercellular adhesion molecule-1 are required for NK cell surveillance of drug-treated tumor cells, which contributes to tumor regressions and prolonged survival in a KRAS-mutant lung cancer mouse model. Therefore, molecularly targeted agents capable of inducing senescence can produce tumor control through non-cell autonomous mechanisms involving NK cell surveillance.

FACTORS AFFECTING BONE REMODELING IN PATIENTS WITH HODGKIN’S LYMPHOMA (REVIEW)

Hodgkin’s lymphoma is considered a potentially curable disease. Chemotherapy-based salvage regimens can achieve responses in 90 % of patients with Hodgkin’s lymphoma. The possibility of achieving persistent disease-free survival poses a problem of ensuring a satisfactory quality of life and preventing the long-term consequences of antitumor therapy. One of those consequences may be a change in bone mineral density. Currently, a number of researchers have established that the risk of osteoporosis and osteopenia is highest in patients with Hodgkin’s lymphoma as compared to patients with other lymphoproliferative disorders. The decrease in bone mineral density can be associated with polychemotherapy including various combinations of cytostatic drugs and glucocorticoids, hypogonadism caused by toxic effects of radiotherapy and chemotherapy, tumor process, low physical activity and other factors. The high importance of the problem of osteoporosis is determined from social consequences - fractures of the vertebral bodies and fractures of the peripheral skeleton. That leads to economic risks in the health care area and causing a high level of disability. The aim of the study was to reveal the main regularities of bone remodeling in patients with Hodgkin’s lymphoma.

Management of recurrent or metastatic endometrial cancer in Germany: results of the nationwide AGO pattern of care studies from the years 2013, 2009 and 2006.

The available literature on the treatment options for recurrent or metastatic endometrial cancer (EC) is full of controversies. Therefore, we explore the results of the AGO pattern of care studies from the years 2013, 2009 and 2006. A questionnaire was developed and sent to all 682 German gynecological departments in 2013 (775 in 2009, 500 in 2006, respectively). The results of the questionnaires were compared with each other using Fisher's exact test. Responses were available in 40.0 % in 2013, 33.3 % in 2009 and 35.8 % in 2006. In 2013 the most preferred endocrine drug was progestin (79.8 %), followed by tamoxifen (42.8 %), aromatase inhibitor (19.8 %), fulvestrant (16.3 %) and a combination (3.9 %) (p < 0.001). 65.3, 59.8, 51.7 and 38.2 % of the participants used platinum, taxane, a combination of cytostatic drugs, anthracycline in metastatic EC, respectively (p = 0.215). 96.2, 92.7, 49.8 and 60.9 % of the participants performed an operation, radiotherapy, endocrine therapy and chemotherapy in 2013 because of a local recurrence, respectively (p < 0.001). Compared to 2009 and 2006 these rates remained stable (no p value <0.05). Because of a distant metastasis 50.4, 64.2, 78.5 and 90.8 % of the participants performed an operation, radiotherapy, endocrine therapy and chemotherapy in 2013, respectively (p < 0.001). Compared to 2009 and 2006 more participants performed an operation or radiotherapy and less an endocrine treatment. Whereas progestin was the favorite drug, the participants of this study did not prefer a specific cytostatic drug for metastatic EC in 2013. This might have reflected the available literature, which did not provide a real standard of care.

THE ANTITUMOR EFFICACY OF CISPLATIN IN COMBINATION WITH TRIPTORELIN AND EXEMESTANE THERAPY FOR AN OVARIAN CANCER ASCITES MODEL IN WISTAR RATS

To study antitumor activity of triptorelin - agonist of gonadotropin-releasing hormone and exemestane - inhibitor of aromatase in combination with cisplatin on the model of receptor-positive for estrogens and progesterone malignant transplantable ascites ovarian tumor (OT); to assess tumor response to treatment and VEGF expression in tumor cells under different combinations of cytostatic and hormonal drugs. 36 female Wistar rats, which underwent intraperitoneal transplantation of ascites OT (5×10(6) cells per animal), have been involved in the study. Rats were distributed into 4 groups (9 rats in each group): group 1 - animals, which received combination of cisplatin and triptorelin; group 2 - rats treated with combination of cisplatin and exemestane; group 3 - animals, which were administered with combination of cisplatin, triptorelin and exemestane; group 4 - rats, which received combination of triptorelin and exemestane. Histological study with assessment of treatment pathomorphosis in OT and immunohistochemical study have been carried out to analyze VEGF expression in OT cells. Survival of animals has been evaluated. Combination of cytostatic agent with triptorelin or exemestane has demonstrated significantly higher rates of treatment pathomorphosis (10.1 ± 0.1% and 16.2 ± 0.3%, respectively) and antiangiogenic activity in OT (21.4 ± 1.4% and 15.0 ± 1.3%, respectively), as well as the highest survival of animals (100.0 and 85.7%, respectively) as compared with the same in rats treated in regimen of monotherapy with cisplatin, triptorelin, exemestane or by combination of hormonal drugs. Among animals treated by combination of cytostatic drug with triptorelin, two were cured (22.2%), and among rats, which received cisplatin and exemestane, one animal (11.1%) was cured. Triptorelin and exemestane increase antitumor activity of cisplatin in respect to the transplantable malignant ascites OT and significantly increase survival of animals, especially when triptorelin and cisplatin are used in combination.

G2/M Arrest Sensitises Erythroid Leukemia Cells to TRAIL-induced Apoptosis

Erythroidl eukemia is a heterogeneous disease with very poor prognosis. It may arise de novo, secondary to myelodysplastic syndrome, blast crisis phase of chronic myeloid leukemia, or after cytotoxic therapy of acute myeloid leukemia. The current mainstream treatment of erythroleukemia is cytarabine and anthracyclin-based chemotherapy or bone marrow transplantation. In the current study we found that cytarabine or inhibition of the DNA-damage-activated protein kinase, ATM, induce G2/M arrest and sensitised K562 erythro leukemia cells to tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). Arresting cells in G2/M with microtubule-disrupting drugs also enhanced TRAIL-sensitivity. Synchronisation or separation of the leukemia cells in different stages of the cell cycle by elutriation confirmed that the cells in G1 and G2/M were sensitive to TRAIL. Interestingly, this sensitivity was associated with cell cycle-dependent oscillation of cFLIP expression. In summary, we found that combination of cytostatic drugs with TRAIL can be an effective treatment for erythroid leukemia

P0126 Cytolytic virus activation therapy for epstein-barr virus driven tumours

Background Epstein-Barr virus (EBV) is causal in WHO-III nasopharyngeal carcinoma (NPC) and 10% of gastric cancers (GC) worldwide. Since all tumour cells carry EBV, the virus itself is a potential target for therapy. However, EBV expresses few non-immunogenic gene products essential for EBV-DNA maintenance and tumour growth. We developed a cytolytic virus activation (CLVA) therapy, reactivating latent EBV into the lytic cycle, triggering immune recognition and inducing susceptibility to antiviral therapy. Methods CLVA combines a cytostatic drug with valproic acid (VPA) for virus reactivation with (val) ganciclovir (GCV) as an antiviral drug preventing virus replication and killing reactivated tumour cells. CLVA treatment was validated in cell lines and mouse models and in a phase-1/2 clinical trial with Dutch NPC patients refractory to conventional treatment. A similar trial is about to start in Indonesia. Findings In NPC and GC cell lines, various cytostatic drug combinations induce the EBV lytic cycle, which is enhanced by VPA. Addition of GCV resulted in higher viable cell elimination. CLVA therapy eliminated NPC tumours in nude mice more efficiently and completely than single drugs alone. Using 131FIAU, CLVA responsive tumours in mice could be visualised by PET scan and DNA load in blood, mRNA profiling, and in situ staining confirmed in vivo virus reactivation. A phase 1/2 study with six cycles of CLVA treatment showed that CLVA was well-tolerated in 11 patients with end-stage NPC. Patients showed increased viral DNA in blood with lytic mRNA in nasopharyngeal brushings during treatment. Treatment showed a good response in five patients, two patients developed stable disease and in four patients no (early) effect was seen and therapy was ended. Approval for a phase 1/2 trial for NPC was obtained in Yogyakarta, Indonesia. Interpretation CLVA successfully activated EBV from latency in NPC and GC tumour cell lines in vitro and cleared NPC tumours from nude mice. In patients, CLVA was well tolerated and showed a biological effect. This new virus-specific CLVA therapy could open a generic approach for treatment of multiple EBV-associated malignancies.

Inhibition of Monocarboxylate Transporter 2 Induces Senescence-Associated Mitochondrial Dysfunction and Suppresses Progression of Colorectal Malignancies In Vivo

Senescence, an inherent tumor suppressive mechanism, is a critical determinant for chemotherapy. In the present study, we show that the monocarboxylate transporter 2 (MCT2) protein was tumor-selectively expressed in human colorectal malignancies and knockdown of MCT2 induces mitochondrial dysfunction, cell-cycle arrest, and senescence without additional cellular stress in colorectal cancer cell lines. Moreover, the reactive oxygen species (ROS) scavenger, N-acetylcysteine, blocked MCT2 knockdown-induced growth arrest and cellular senescence, indicating a pivotal role of ROS in this pathway. Dramatic induction of mitochondrial superoxide generation and decrease in ATP production was observed, indicating that mitochondrial dysfunction is the major mechanism underlying MCT2 knockdown-induced ROS generation. Senescence-associated DNA damage was also evident from the increase in promyelocytic leukemia bodies, γH2AX foci, and SAHF. Conversely, overexpression of MCT2 prevented doxorubicin-induced ROS accumulation (P = 0.0002) and cell growth inhibition (P = 0.001). MCT2 knockdown suppressed KRAS mutant colorectal tumor growth in vivo. In addition, MCT2 knockdown and cytostatic drug combination further enhanced the antitumor effect. These findings support the use of MCT2 as a promising target for inhibition of colorectal cancer.

Diagnostic Platform for Personalized Chemosensitivity Assays - Robust Results via Process Automation

Diagnostic Platform for Personalized Chemosensitivity Assays - Robust Results via Process Automation

Assessment of anti-inflammatory tumor treatment efficacy by longitudinal monitoring employing sonographic micro morphology in a preclinical mouse model

BackgroundWith the development of increasingly sophisticated three-dimensional volumetric imaging methods, tumor volume can serve as a robust and reproducible measurement of drug efficacy. Since the use of molecularly targeted agents in the clinic will almost certainly involve combinations with other therapeutic modalities, the use of volumetric determination can help to identify a dosing schedule of sequential combinations of cytostatic drugs resulting in long term control of tumor growth with minimal toxicity. The aim of this study is to assess high resolution sonography imaging for the in vivo monitoring of efficacy of Infliximab in pancreatic tumor.MethodsIn the first experiment, primary orthotopic pancreatic tumor growth was measured with Infliximab treatment. In the second experiment, orthotopic tumors were resected ten days after inoculation of tumor cells and tumor recurrence was measured following Infliximab treatment. Tumor progression was evaluated using 3D high resolution sonography.ResultsSonography measurement of tumor volume in vivo showed inhibitory effect of Infliximab on primary tumor growth in both non-resected and resected models. Measurement of the dynamics of tumor growth by sonography revealed that in the primary tumor Infliximab is effective against established tumors while in the resection model, Infliximab is more effective at an early stage following tumor resection. Infliximab treatment is also effective in inhibiting tumor growth growth as a result of tumor cell contamination of the surgical field.ConclusionsClinical application of Infliximab is feasible in both the neoadjuvant and adjuvant setting. Infliximab is also effective in slowing the growth of tumor growth under the peritoneum and may have application in treating peritoneal carcinomatosis. Finally the study demonstrates that high resolution sonography is a sensitive imaging modality for the measurement of pancreatic tumor growth.

Nonpegylated liposomal doxorubicin is highly active in patients with B and T/NK cell lymphomas with cardiac comorbidity or higher age

We used nonpegylated liposomal doxorubicin (NPLD) in cytostatic drug combinations to treat 37 patients with non-Hodgkin's lymphoma and pre-existing cardiac disorder or elderly patients with reduced physical state who were ineligible for conventional anthracycline-containing therapy. High remission rates were observed in this poor-risk population: Complete remission rates were 75% for diffuse large B cell lymphoma (DLBCL) and 55% for T/NK cell neoplasm (overall response rate of 80% and 89%, respectively). Twenty-seven patients (73%) are still alive after a median observation time of 14 months. No major cardiac or gastrointestinal toxicity was observed. Extravasation of NPLD in two patients resulted in mild inflammation without tissue damage. Hematologic toxicity was comparable to that of conventional anthracycline-containing regimens. We conclude that NPLD is highly active in combination chemotherapy for lymphoma with low cardiac toxicity in patients with pre-existing cardiac disorders or higher age. Moreover, we also observed remarkable efficacy in T/NK cell lymphomas.

Involvement of drug transporters in the synergistic action of FOLFOX combination chemotherapy

FOLFOX is a cytostatic drug combination for adjuvant treatment of colorectal cancer (CRC) consisting of 5-fluorouracil (5-FU), leucovorin, and oxaliplatin. The mechanism of synergistic interaction of these drugs is poorly understood and little is known concerning the role of drug transporters and the impact of oxaliplatin metabolites oxalate and dichloro-diaminocyclohexane platinum. We therefore investigated the influence of FOLFOX components on drug transporter expression by quantitative real-time polymerase chain reaction and on the efficacy of each FOLFOX component by proliferation assay in the CRC model cell line LS180. Control experiments with transporter over-expressing cell lines were used to assess the significance of important transporters for the cytostatic activity of FOLFOX components. Moreover, we assessed the pharmacological contribution of the oxalato-ligand to the effect of oxaliplatin. FOLFOX components led to several alterations in expression of drug transporters. For instance, 5-FU significantly suppressed ATP7B and human organic cation transporter 2 and increased multidrug resistance-associated protein (MRP) 2 mRNA expression (5.8-fold). This was accompanied by a significant sensitisation to oxaliplatin. Over-expression of certain ABC-transporters (BCRP/ABCG2, MRP2/ABCC2 or MRP3/ABCC3) was demonstrated to be beneficial for the efficacy of oxaliplatin. The results obtained indicate that both down- and up-regulations of drug transporters could favour synergistic action of this drug combination. Moreover, oxaliplatin metabolite oxalate seems to positively modulate oxaliplatin's action as elucidated by median effect analysis. In conclusion, we propose as one mechanism for FOLFOX synergism the 5-FU mediated suppression of ATP7B, the over-expression of glutathione exporters such as MRP2/ABCC2 and the decrease of glutathione levels by oxalate.

Synergistic induction of apoptosis in neuroblastoma cells using a combination of cytostatic drugs with interferon-γ and TRAIL

The majority of high-risk neuroblastomas lack the expression of caspase-8 due to gene silencing which suggest a mechanism for the selection of tumour cells that are refractory to multiple cytotoxic drugs including tumour necrosis factor-related apoptosis-inducing ligand (TRAIL). Inhibitors of DNA methyltransferases and IFN-gamma induce expression of caspase-8, and sensitise some neuroblastoma cells to TRAIL-mediated apoptosis. Here we demonstrate that a combination of cytostatic drugs with IFN-gamma and TRAIL synergistically induces neuroblastoma cell death, which may have implications for future therapy of children with neuroblastoma. Treatment of neuroblastoma cells with IFN-gamma induced caspase-8 expression in all cell lines investigated. In five of the neuroblastoma cell lines (SHEP-1, SK-N-AS, SK-N-FI, SH-SY-5Y and Kelly), IFN-gamma promoted TRAIL-mediated cleavage of caspase-8, initiating a caspase cascade involving caspase-7 and PARP followed by apoptosis. IFN-gamma-mediated facilitation of apoptosis was inhibited by the pan-caspase inhibitor zVAD-fmk and the caspase-8 specific inhibitor zIEDT-fmk, indicating an important role of caspase-8 in mediating sensitation by IFN-gamma in neuroblastoma cells. In three of the cell lines [SK-N-BE(2), SK-N-DZ and IMR-32] caspase-8 expression was induced by IFN-gamma, but the cells were still resistant to TRAIL-mediated apoptosis. The pattern of basal TRAIL receptor expression, decoy receptors, FLIP and FADD could not be correlated with resistance or sensitivity to TRAIL-induced apoptosis. Importantly, treatment of neuroblastoma cell lines with cytostatic drugs increased apoptosis in the TRAIL-sensitive cell lines whereas the resistant cell lines were susceptible to TRAIL-mediated apoptosis in the presence of the anticancer drugs. The mechanism of the increased susceptibility to apoptosis might results from drug-mediated up-regulation of the death receptors DR4 and DR5.

Supra-Additive Cytotoxic Effects of a Combination of Cytostatic Drugs and Antibody-Induced Complement Activation on Tumor Cells in vitro

Chemotherapy with cytostatic and cytotoxic drugs is the main treatment modality for disseminated cancer. However, despite initial clinical responses seen in certain histotypes, such as small cell lung cancer, relapses mostly occur with chemoresistant phenotypes. In order to prolong the relapse-free period, a combination of chemo- and immunotherapy might offer a new treatment strategy. Here, we have tested our hypothesis that complement activation, induced by monoclonal antibodies, in combination with cytostatic drugs may result in additive cytotoxicity in vitro. Doxorubicin, cisplatinum and etoposide were tested in combination with human complement and a murine monoclonal antibody (MAb F12) directed against the tumor-associated ganglioside antigen fucosyl GM1 on a rat hepatoma (H4-II-E) cell line which was used as tumor model. Using the MTT assay to measure cell survival, supra-additive (i.e. synergistic) cytotoxic effects were seen with each of the cytostatic drugs, the strongest being observed with doxorubicin. These results show promise for further research exploring possible prognostically favorable interactions between cytostatic drugs and monoclonal antibodies in the treatment of cancer.

Therapeutic options in the treatment of multiple myeloma: pharmacoeconomic and quality-of-life considerations.

A review of current treatment options in multiple myeloma is presented, including data on health-related quality of life and pharmacoeconomics. For induction chemotherapy, no combination of cytostatic drugs has been shown to be consistently superior to the simple cyclic oral treatment with melphalan and prednisone that has been available for 30 years. The total resource consumption and direct costs per patient treated with melphalan and prednisone is approximately $US10,000 (1995 values). As median survival is prolonged from less than a year in untreated patients to 30 to 36 months, this treatment must be considered cost effective. Interferon-alpha has a modest effect on progression-free and overall survival when added to chemotherapy regimens. However, the high cost and toxicity of this drug results in an unfavourable cost-utility ratio, estimated to be between $US50,000 to $US100,000 per quality-adjusted life-year gained. Clinical trials suggest that high dose chemotherapy followed by autologous stem cell support administered to patients who have achieved disease stabilisation or objective response to conventional induction chemotherapy, prolongs median survival by about 1.5 years. Preliminary cost-utility analyses suggest a cost per life-year gained of $US30,000 to $US40,000. Further potential improvements of this therapeutic modality are under way. Several bisphosphonates have been tested for the ability to prevent the skeletal complications of multiple myeloma. Monthly infusions of pamidronate have been shown in 1 randomised trial to significantly reduce the rate of skeletal complications. Unfortunately, the rapid and widespread acceptance of this therapy seems to preclude further prospective, placebo-controlled trials with cost-utility evaluation.

Is the progress in cancer treatment results adequate or are we confronted with a more or less worldwide stagnation?

Recent results of ongoing multicenter cooperative studies on patients treated with multimodality therapies of small-cell bronchial carcinoma are used as an example to demonstrate the definite progress of treatment results. This was possible only after a gradual development of aggressive intermittent long-term chemotherapy by different combinations of cytostatic drugs combined with various other kinds of therapy during the last three decades. The evaluation of results was only feasible after a step-by-step development of the international uniform pTNM staging system. This example is also useful to demonstrate the possible increased impact of these results, in spite of a very selected small number of patients, on the overall statistical survival with the assumption that the evaluable methods will be applied by a greater number of cooperative groups and in general practice. The life-table curves of pTNM-I-staged patients show a plateau of over 60% for the 4-year-survival rate, demonstrating much better results by comparison with non-surgical combined modality (radio- and chemotherapy) treatments. They are also much better than generally expected, which in turn demonstrates the great discrepancy in importance between the results from a scientific theoretical and a practical point of view. Only since the TNM staging system was developed has it been possible to distinguish the stages based on clinical diagnostic procedures, with a lower grade of certainty, from those with the precise pTNM staging based on the pathohistological findings.