109 research outputs found
Effect of priming with granulocyte colony-stimulating factor on the outcome of chemotherapy for acute myeloid leukemia
BACKGROUND: Sensitization of leukemic cells with hematopoietic growth
factors may enhance the cytotoxicity of chemotherapy in acute myeloid
leukemia (AML). METHODS: In a multicenter randomized trial, we assigned
patients (age range, 18 to 60 years) with newly diagnosed AML to receive
cytarabine plus idarubicin (cycle 1) and cytarabine plus amsacrin (cycle
2) with granulocyte colony-stimulating factor (G-CSF) (321 patients) or
without G-CSF (319). G-CSF was given concurrently with chemotherapy only.
Idarubicin and amsacrin were given at the end of a cycle to allow the
cell-cycle-dependent cytotoxicity of cytarabine in the context of G-CSF to
have a greater effect. The effect of G-CSF on disease-free survival was
assessed in all patients and in cytogenetically distinct prognostic
subgroups. RESULTS: After induction chemotherapy, the rates of response
were not significantly different in the two groups. After a median
follow-up of 55 months, patients in complete remission after induction
chemotherapy plus G-CSF had a higher rate of disease-free survival than
patients who did not receive G-CSF (42 percent vs. 33 percent at four
years, P=0.02), owing to a reduced probability of relapse (relative risk,
0.77; 95 percent confidence interval, 0.61 to 0.99; P=0.04). G-CSF did not
significantly improve overall survival (P=0.16). Although G-CSF did not
improve the outcome in the subgroup with an unfavorable prognosis, the 72
percent of patients with standard-risk AML benefited from G-CSF therapy
(overall survival at four years, 45 percent, as compared with 35 percent
in the group that did not receive G-CSF [relative risk of death, 0.75; 95
percent confidence interval, 0.59 to 0.95; P=0.02]; disease-free survival,
45 percent vs. 33 percent [relative risk, 0.70]; 95 percent confidence
interval, 0.55 to 0.90; P=0.006). CONCLUSIONS: Sensitization of leukemic
cells with growth factors is a clinically applicable means of enhancing
the efficacy of chemotherapy in patients with AML
Multitarget Stool DNA Test Performance in an Average-Risk Colorectal Cancer Screening Population
INTRODUCTION: We set out to evaluate the performance of a multitarget stool DNA (MT-sDNA) in an average-risk colonoscopy-controlled colorectal cancer (CRC) screening population. MT-sDNA stool test results were evaluated against fecal immunochemical test (FIT) results for the detection of different lesions, including molecularly defined high-risk adenomas and several other tumor characteristics. METHODS: Whole stool samples (n = 1,047) were prospectively collected and subjected to an MT-sDNA test, which tests for KRAS mutations, NDRG4 and BMP3 promoter methylation, and hemoglobin. Results for detecting CRC (n = 7), advanced precancerous lesions (advanced adenoma [AA] and advanced serrated polyps; n = 119), and non-AAs (n = 191) were compared with those of FIT alone (thresholds of 50, 75, and 100 hemoglobin/mL). AAs with high risk of progression were defined by the presence of specific DNA copy number events as measured by low-pass whole genome sequencing. RESULTS: The MT-sDNA test was more sensitive than FIT alone in detecting advanced precancerous lesions (46% (55/119) vs 27% (32/119), respectively, P < 0.001). Specificities among individuals with nonadvanced or negative findings (controls) were 89% (791/888) and 93% (828/888) for MT-sDNA and FIT testing, respectively. A positive MT-sDNA test was associated with multiple lesions (P = 0.005), larger lesions (P = 0.03), and lesions with tubulovillous architecture (P = 0.04). The sensitivity of the MT-sDNA test or FIT in detecting individuals with high-risk AAs (n = 19) from individuals with low-risk AAs (n = 52) was not significantly different. DISCUSSION: In an average-risk screening population, the MT-sDNA test has an increased sensitivity for detecting advanced precancerous lesions compared with FIT alone. AAs with a high risk of progression were not detected with significantly higher sensitivity by MT-sDNA or FIT
Synthesis of a Dual Functional Anti-MDR Tumor Agent PH II-7 with Elucidations of Anti-Tumor Effects and Mechanisms
Multidrug resistance mediated by P-glycoprotein in cancer cells has been a major issue that cripples the efficacy of chemotherapy agents. Aimed for improved efficacy against resistant cancer cells, we designed and synthesized 25 oxindole derivatives based on indirubin by structure-activity relationship analysis. The most potent one was named PH II-7, which was effective against 18 cancer cell lines and 5 resistant cell lines in MTT assay. It also significantly inhibited the resistant xenograft tumor growth in mouse model. In cell cycle assay and apoptosis assay conducted with flow cytometry, PH II-7 induced S phase cell cycle arrest and apoptosis even in resistant cells. Consistently revealed by real-time PCR, it modulates the expression of genes related to the cell cycle and apoptosis in these cells, which may contributes to its efficacy against them. By side-chain modification and FITC-labeling of PH II-7, we were able to show with confocal microscopy that not only it was not pumped by P-glycoprotein, it also attenuated the efflux of Adriamycin by P-glycoprotein in MDR tumor cells. Real-time PCR and western blot analysis showed that PH II-7 down-regulated MDR1 gene via protein kinase C alpha (PKCA) pathway, with c-FOS and c-JUN as possible mediators. Taken together, PH II-7 is a dual-functional compound that features both the cytotoxicity against cancer cells and the inhibitory effect on P-gp mediated drug efflux
Melanoma: A model for testing new agents in combination therapies
Treatment for both early and advanced melanoma has changed little since the introduction of interferon and IL-2 in the early 1990s. Recent data from trials testing targeted agents or immune modulators suggest the promise of new strategies to treat patients with advanced melanoma. These include a new generation of B-RAF inhibitors with greater selectivity for the mutant protein, c-Kit inhibitors, anti-angiogenesis agents, the immune modulators anti-CTLA4, anti-PD-1, and anti-CD40, and adoptive cellular therapies. The high success rate of mutant B-RAF and c-Kit inhibitors relies on the selection of patients with corresponding mutations. However, although response rates with small molecule inhibitors are high, most are not durable. Moreover, for a large subset of patients, reliable predictive biomarkers especially for immunologic modulators have not yet been identified. Progress may also depend on identifying additional molecular targets, which in turn depends upon a better understanding of the mechanisms leading to response or resistance. More challenging but equally important will be understanding how to optimize the treatment of individual patients using these active agents sequentially or in combination with each other, with other experimental treatment, or with traditional anticancer modalities such as chemotherapy, radiation, or surgery. Compared to the standard approach of developing new single agents for licensing in advanced disease, the identification and validation of patient specific and multi-modality treatments will require increased involvement by several stakeholders in designing trials aimed at identifying, even in early stages of drug development, the most effective way to use molecularly guided approaches to treat tumors as they evolve over time
Splenic Ly6C(hi) monocytes contribute to adverse late post-ischemic left ventricular remodeling in heme oxygenase-1 deficient mice
Chemotherapy elicits pro-metastatic extracellular vesicles in breast cancer models
Cytotoxic chemotherapy is an effective treatment for invasive breast cancer. However, experimental studies in mice also suggest that chemotherapy has pro-metastatic effects. Primary tumours release extracellular vesicles (EVs), including exosomes, that can facilitate the seeding and growth of metastatic cancer cells in distant organs, but the effects of chemotherapy on tumour-derived EVs remain unclear. Here we show that two classes of cytotoxic drugs broadly employed in pre-operative (neoadjuvant) breast cancer therapy, taxanes and anthracyclines, elicit tumour-derived EVs with enhanced pro-metastatic capacity. Chemotherapy-elicited EVs are enriched in annexin A6 (ANXA6), a Ca2+-dependent protein that promotes NF-κB-dependent endothelial cell activation, Ccl2 induction and Ly6C+CCR2+ monocyte expansion in the pulmonary pre-metastatic niche to facilitate the establishment of lung metastasis. Genetic inactivation of Anxa6 in cancer cells or Ccr2 in host cells blunts the prometastatic effects of chemotherapy-elicited EVs. ANXA6 is detected, and potentially enriched, in the circulating EVs of breast cancer patients undergoing neoadjuvant chemotherapy
Vitamin A derivatives in the prevention and treatment of human cancer.
Vitamin A is essential for normal cellular growth and differentiation. A vast amount of laboratory data have clearly demonstrated the potent antiproliferative and differentiation-inducing effects of vitamin A and the synthetic analogues (retinoids). Recent in-vitro work has led to the exciting proposal that protein kinase-C may be centrally involved in many of retinoids' anticancer actions including the effects on ornithine decarboxylase induction, intracellular polyamine levels, and epidermal growth factor receptor number. Several intervention trials have clearly indicated that natural vitamin A at clinically tolerable doses has only limited activity against human neoplastic processes. Therefore, clinical work has focused on the synthetic derivatives with higher therapeutic indexes. In human cancer prevention, retinoids have been most effective for skin diseases, including actinic keratosis, keratoacanthoma, epidermodysplasia verruciformis, dysplastic nevus syndrome, and basal cell carcinoma. Several noncutaneous premaligancies, however, are currently receiving more attention in retinoid trials. Definite retinoid activity has been documented in oral leukoplakia, laryngeal papillomatosis, superficial bladder carcinoma, cervical dysplasia, bronchial metaplasia, and preleukemia. Significant therapeutic advances are also occurring with this class of drugs in some drug-resistant malignancies and several others that have become refractory, including advanced basal cell cancer, mycosis fungoides, melanoma, acute promyelocytic leukemia, and squamous cell carcinoma of the skin and of the head and neck. This report comprehensively presents the clinical data using retinoids as anticancer agents in human premalignant disorders and outlines the ongoing and planned studies with retinoids in combination and adjuvant therapy
New animal models of progressive neurodegeneration: tools for identifying targets in predictive diagnostics and presymptomatic treatment
Diagnostic image (92). A man with fever during chemotherapy. Invasive pulmonary mycosis
A 64-year-old male was treated for acute myeloid leukemia with idarubicin and cytarabin. He developed pulmonary mycosis (radiologically consistent with aspergillosis), which responded to intravenous amphotericin B.</p
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