cyclin-d1 and Neutropenia

Cyclin D/CDK4/6 is critical in controlling the G1 to S checkpoint. CCND, the gene encoding cyclin D, is known to be amplified in a variety of solid tumors. Palbociclib is an oral CDK4/6 inhibitor, approved in advanced breast cancer in combination with endocrine therapy. We explored the efficacy of palbociclib in patients with nonbreast solid tumors containing an amplification in CCND1, 2, or 3.. Patients with tumors containing a CCND1, 2, or 3 amplification and expression of the retinoblastoma protein were assigned to subprotocol Z1B and received palbociclib 125 mg once daily for 21 days of a 28-day cycle. Tumor response was assessed every two cycles.. Forty patients were assigned to subprotocol Z1B; 4 patients had outside assays identifying the CCND1, 2, or 3 amplification and were not confirmed centrally; 3 were ineligible and 2 were not treated (1 untreated patient was also ineligible), leaving 32 evaluable patients for this analysis. There were no partial responses; 12 patients (37.5%) had stable disease as best response. There were seven deaths on study, all during cycle 1 and attributable to disease progression. Median progression-free survival was 1.8 months. The most common toxicities were leukopenia (n = 21, 55%) and neutropenia (n = 19, 50%); neutropenia was the most common grade 3/4 event (n = 12, 32%).. Palbociclib was not effective at treating nonbreast solid tumors with a CCND1, 2, or 3 amplification in this cohort. These data do not support further investigation of single-agent palbociclib in tumors with CCND1, 2, or 3 amplification.

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin D1; Female; Humans; Neutropenia; Piperazines; Pyridines

ABT-751 is a novel antimitotic agent that exerted cytotoxic effects in preclinical studies. Carboplatin has efficacy in treating advanced non-small cell lung cancer (NSCLC) in combination with other drugs.. Lung cancer cell lines were treated with ABT-751 and/or carboplatin to investigate their impact on cell growth. A phase I study with an expansion cohort was conducted in previously treated NSCLC patients. The primary objective was the maximum tolerated dose (MTD); secondary objectives were objective response rates, median survival, time to tumor progression, dose-limiting toxicities (DLTs), and pharmacodynamic evaluation of buccal swabs.. Combining ABT-751 with carboplatin significantly reduced growth and induced apoptosis of lung cancer cell lines. Twenty advanced NSCLC patients were enrolled. MTD was ABT-751 125 mg orally twice daily for 7 days with carboplatin AUC 6. DLTs included fatigue, ileus, neutropenia and pneumonitis. Two patients had confirmed partial responses. Median overall survival was 11.7 months (95% CI 5.9-27.0). Time to tumor progression was 2.8 months (95% CI 2.0-2.7). Four of 6 patients showed decreased cyclin D1 protein in posttreatment versus pretreatment buccal swabs.. Combining ABT-751 with carboplatin suppressed growth of lung cancer cell lines and had modest clinical antitumor activity in advanced NSCLC previously treated predominantly with carboplatin. Further studies of this combination are not recommended while investigations of biomarkers in different patient populations, alternative schedules and combinations may be pursued.

Topics: Administration, Oral; Aged; Antineoplastic Agents; Apoptosis; Area Under Curve; Carboplatin; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cyclin D1; Drug Therapy, Combination; Fatigue; Female; Humans; Ileus; Lung Neoplasms; Male; Middle Aged; Neutropenia; Pneumonia; Sulfonamides; Survival Rate

We demonstrate here that lymphoid enhancer-binding factor 1 (LEF-1) mediates the proliferation, survival and differentiation of granulocyte progenitor cells. We initially documented the importance of this transcription factor in the bone marrow of individuals with severe congenital neutropenia (CN) with a 'differentiation block' at the promyelocytic stage of myelopoiesis. LEF-1 expression was greatly reduced or even absent in CN arrested promyelocytes, resulting in defective expression of the LEF-1 target genes CCND1, MYC and BIRC5, encoding cyclin D1 (ref. 2), c-Myc and survivin, respectively. In contrast, healthy individuals showed highest LEF-1 expression in promyelocytes. Reconstitution of LEF-1 in early hematopoietic progenitors of two individuals with CN corrected the defective myelopoiesis and resulted in the differentiation of these progenitors into mature granulocytes. Repression of endogenous LEF-1 by specific short hairpin RNA inhibited proliferation and induced apoptosis of CD34(+) progenitors from healthy individuals and of cells from two myeloid lines (HL-60 and K562). C/EBPalpha, a key transcription factor in granulopoiesis, was directly regulated by LEF-1. These observations indicate that LEF-1 is an instructive factor regulating neutrophilic granulopoiesis whose absence plays a critical role in the defective maturation program of myeloid progenitors in individuals with CN.

Topics: Antigens, CD; Antigens, CD34; Antigens, Differentiation, Myelomonocytic; Base Sequence; Cyclin D1; Gene Expression Regulation; Granulocytes; Hematopoietic Stem Cells; HL-60 Cells; Humans; K562 Cells; Lymphoid Enhancer-Binding Factor 1; Molecular Sequence Data; Neutropenia; Neutrophils; Proto-Oncogene Proteins c-myc; Sialic Acid Binding Ig-like Lectin 3