Effects of combined treatment with rapamycin and cotylenin A, a novel differentiation-inducing agent, on human breast carcinoma MCF-7 cells and xenografts

INTRODUCTION: Rapamycin, an inhibitor of the serine/threonine kinase target of rapamycin, induces G(1 )arrest and/or apoptosis. Although rapamycin and its analogues are attractive candidates for cancer therapy, their sensitivities with respect to growth inhibition differ markedly among various cancer cells. Using human breast carcinoma cell line MCF-7 as an experimental model system, we examined the growth-inhibitory effects of combinations of various agents and rapamycin to find the agent that most potently enhances the growth-inhibitory effect of rapamycin. METHOD: We evaluated the growth-inhibitory effect of rapamycin plus various agents, including cotylenin A (a novel inducer of differentiation of myeloid leukaemia cells) to MCF-7 cells, using either MTT assay or trypan blue dye exclusion test. The cell cycle was analyzed using propidium iodide-stained nuclei. Expressions of several genes in MCF-7 cells with rapamycin plus cotylenin A were studied using cDNA microarray analysis and RT-PCR. The in vitro results of MCF-7 cells treated with rapamycin plus cotylenin A were further confirmed in vivo in a mouse xenograft model. RESULTS: We found that the sensitivity of rapamycin to MCF-7 cells was markedly affected by cotylenin A. This treatment induced growth arrest of the cells at the G(1 )phase, rather than apoptosis, and induced senescence-associated β-galactosidase activity. We examined the gene expression profiles associated with exposure to rapamycin and cotylenin A using cDNA microarrays. We found that expressions of cyclin G(2), transforming growth factor-β-induced 68 kDa protein, BCL2-interacting killer, and growth factor receptor-bound 7 were markedly induced in MCF-7 cells treated with rapamycin plus cotylenin A. Furthermore, combined treatment with rapamycin and cotylenin A significantly inhibited the growth of MCF-7 cells as xenografts, without apparent adverse effects. CONCLUSION: Rapamycin and cotylenin A cooperatively induced growth arrest in breast carcinoma MCF-7 cells in vitro, and treatment with rapamycin and cotylenin A combined more strongly inhibited the growth of MCF-7 cells as xenografts in vivo than treatment with rapamycin or cotylenin A alone, suggesting that this combination may have therapeutic value in treating breast cancer. We also identified several genes that were markedly modulated in MCF-7 cells treated with rapamycin plus cotylenin A

Differentially expressed genes in a flock of Chinese local-breed chickens infected with a subgroup J avian leukosis virus using suppression subtractive hybridization

Avian leukosis virus subgroup J (ALV-J) is a new type of virus that mainly induces myeloid leukosis (ML) in chickens. To further elucidate the pathogenesis of ALV-J infection and tumor development, expression profiles from the bone marrow tissue of 15 infected and 18 non-infected birds from a local-breed poultry-farm under naturally infected conditions, were analyzed by suppression-subtractive hybridization. The birds were diagnosed as ML+ (or ML-) by specific ALV-J detection methods, involving serological tests for antigens and antibodies, and RT-PCR to detect viral RNA. A total of 59 partial gene sequences were revealed by differential screening of 496 forward and 384 reverse subtracted cDNA clones. Of these, 22 identified genes, including 8 up-regulated and 14 down-regulated, were related to immune functions, these genes being, MHC B-G antigen, translationally-controlled tumor protein (TPT1/TPTC), transferrin and ferritin, hemoglobin and Carbonic anhydrase. Four of the down-regulated genes were selected for further analysis, in view of their predicted roles in infection and immunity by real-time qRT-PCR, using RNA collected from the same birds as those used for SSH. The four genes were expressed at significantly lower levels (p < 0.001) in ALV-J infected birds than in non-infected ones

KPT-330 has antitumour activity against non-small cell lung cancer.

BackgroundWe investigated the biologic and pharmacologic activities of a chromosome region maintenance 1 (CRM1) inhibitor against human non-small cell lung cancer (NSCLC) cells both in vitro and in vivo.MethodsThe in vitro and in vivo effects of a novel CRM1 inhibitor (KPT-330) for a large number of anticancer parameters were evaluated using a large panel of 11 NSCLC cell lines containing different key driver mutations. Mice bearing human NSCLC xenografts were treated with KPT-330, and tumour growth was assessed.ResultsKPT-330 inhibited proliferation and induced cell cycle arrest and apoptosis-related proteins in 11 NSCLC cells lines. Moreover, the combination of KPT-330 with cisplatin synergistically enhanced the cell kill of the NSCLC cells in vitro. Human NSCLC tumours growing in immunodeficient mice were markedly inhibited by KPT-330. Also, KPT-330 was effective even against NSCLC cells with a transforming mutation of either exon 20 of EGFR, TP53, phosphatase and tensin homologue, RAS or PIK3CA, suggesting the drug might be effective against a variety of lung cancers irrespective of their driver mutation.ConclusionsOur results support clinical testing of KPT-330 as a novel therapeutic strategy for NSCLC

ASXL2 regulates hematopoiesis in mice and its deficiency promotes myeloid expansion

10.3324/haematol.2018.189928Haematologica103121980-199

Adiposity, dyslipidemia, and insulin resistance in mice with targeted deletion of phospholipid scramblase 3 (PLSCR3)

The phospholipid scramblases (PLSCR1 to PLSCR4) are a structurally and functionally unique class of proteins, which are products of a tetrad of genes conserved from Caenorhabditis elegans to humans. The best characterized member of this family, PLSCR1, is implicated in the remodeling of the transbilayer distribution of plasma membrane phospholipids but is also required for normal signaling through select growth factor receptors. Mice with targeted deletion of PLSCR1 display perinatal granulocytopenia due to defective response of hematopoietic precursors to granulocyte colony-stimulating factor and stem cell factor. To gain insight into the biologic function of another member of the PLSCR family, we investigated mice with targeted deletion of PLSCR3, a protein that like PLSCR1 is expressed in many blood cells but which, by contrast to PLSCR1, is also highly expressed in fat and muscle. PLSCR3(-/-) mice at 2 months of age displayed aberrant accumulation of abdominal fat when maintained on standard rodent chow, which was accompanied by insulin resistance, glucose intolerance, and dyslipidemia. Primary adipocytes and cultured bone-marrow-derived macrophages from PLSCR3(-/-) mice were engorged with neutral lipid, and adipocytes displayed defective responses to exogenous insulin. Plasma of PLSCR3(-/-) mice was elevated in non-high-density lipoproteins, cholesterol, triglycerides, nonesterified fatty acids, and leptin, whereas adiponectin was low. These data suggest that the expression of PLSCR3 may be required for normal adipocyte and/or macrophage maturation or function and raise the possibility that deletions or mutations affecting the PLSCR3(-/-) gene locus may contribute to the risk for lipid-related disorders in humans