Cyclin A1 and P450 aromatase promote metastatic homing and growth of stem-like prostate cancer cells in the bone marrow

Bone metastasis is a leading cause of morbidity and mortality in prostate cancer (PCa). While cancer stem-like cells have been implicated as a cell of origin for PCa metastases, the pathways which enable metastatic development at distal sites remain largely unknown. In this study, we illuminate pathways relevant to bone metastasis in this disease. We observed that cyclin A1 (CCNA1) protein expression was relatively higher in PCa metastatic lesions in lymph node, lung, and bone/bone marrow. In both primary and metastatic tissues, cyclin A1 expression was also correlated with aromatase (CYP19A1), a key enzyme that directly regulates the local balance of androgens to estrogens. Cyclin A1 overexpression in the stem-like ALDHhigh subpopulation of PC3M cells, one model of PCa, enabled bone marrow integration and metastatic growth. Further, cells obtained from bone marrow metastatic lesions displayed self-renewal capability in colony forming assays. In the bone marrow, Cyclin A1 and aromatase enhanced local bone marrow-releasing factors, including androgen receptor, estrogen and matrix metalloproteinase MMP9 and promoted hte metastatic growth of PCa cells. Moreover, ALDHhigh tumor cells expressing elevated levels of aromatase stimulated tumor/host estrogen production and acquired a growth advantage in the presence of host bone marrow cells. Overall, these findings suggest that local production of steroids and MMPs in the bone marrow may provide a suitable microenvironment for ALDHhigh PCa cells to establish metastatic growths, offering new approaches to therapeutically target bone metastases

Metadherin: A Therapeutic Target in Multiple Cancers

Altered expression of many genes and proteins is essential for cancer development and progression. Recently, the affected expression of metadherin (MTDH), also known as AEG-1 (Astrocyte Elevated Gene 1) and Lyric, has been implicated in various aspects of cancer progression and metastasis. Elevated expression of MTDH/AEG-1 has been reported in many cancers including breast, prostate, liver, and esophageal cancers, whereas its expression is low or absent in non-malignant tissues. These expression studies suggest that MTDH may represent a potential tumor associated antigen. MTDH also regulates multiple signaling pathways including PI3K/Akt, NF-κB, Wnt/β-catenin, and MAPK which cooperate to promote the tumorigenic and metastatic potential of transformed cells. Several microRNA have also been found to be associated with the increased MTDH expression in different cancers. Increased MTDH levels were linked to the tumor chemoresistance making it an attractive novel therapeutic target. In this review, we summarize data on MTDH function in various cancers

Regulation of normal and cancer cells as a base for cell cycle-targeted therapy

The majority of current treatments used for treatment of prostate cancer (PCa) and leukemia are often limited to a narrow subsets of treated patients. As such, there still remains a significant scope for gaining deeper understanding of molecular mechanisms underlying cancer metastasis for improvement of targeted treatment. Elevated expression of a cell cycle regulator cyclin A1 initiated leukemia in transgenic mice and also promoted metastasis of prostate cancer cells in xenograft mouse model. Cyclin A1/CDK1 complexes play an essential role in G2/M cell cycle transition in male germ cells. My thesis work is focused on several specific aims: i) to investigate whether promoter methylation patterns in several key cellular regulators are altered in leukemic cells; ii) to elucidate cyclin A1 function in normal hematopoietic stem and progenitor cells (HSPC) and their interaction with stem cell niches; iii) to study the role of cyclin A1 in proliferation and treatment response of cancer stem cells; iv) to study the role of CDK1, a major kinase partner of cyclin A1, in treatment response of leukemic cells. In these studies we used patient materials, cancer cell lines, and knockout and xenograft mouse models. We show that promoter methylation patterns are changed in several key genes, in particular p16 in leukemic cells compared to their normal counterparts, and that such epigenetic changes are also associated with treatment response to therapeutic drugs. Next, we show that cyclin A1 function is required for HSPC to home to and interact with niche regions under steady state condition and upon γ-irradiation treatment. The regulation of HSPC numbers and their interaction with the niches by cyclin A1 are critical for protection of the bone marrow from injury. We further show that the introduction of cyclin A1 overexpression promotes expansion of ALDH-positive population representing cancer stem cells in cell lines, increase their ability to form tumor spheres in vitro, and to metastasize in xenograft mice. Overexpression of cyclin A1 reduced sensitivity of ALDH-positive population within PCa cells to avastin and docetaxel combination treatment. Finally, we show that cyclin A1 associated CDK1 and its associated network proteins in particular RARγ are responsible for cell cycle progression through G0/G1 and G2/M phases. CDK1 and RARγ function are required to facilitate ATRA-effect on leukemic cells. Our findings unravel cellular mechanism underlying proliferation and survival of normal stem cells and cancer stem cells under steady state condition and upon treatment. Our novel findings shield light for designing novel treatment strategies to overcome drug-resistance of cancer cells

Therapeutic Editing of the TP53 Gene: Is CRISPR/Cas9 an Option?

The TP53 gene encodes the transcription factor and oncosuppressor p53 protein that regulates a multitude of intracellular metabolic pathways involved in DNA damage repair, cell cycle arrest, apoptosis, and senescence. In many cases, alterations (e.g., mutations of the TP53 gene) negatively affect these pathways resulting in tumor development. Recent advances in genome manipulation technologies, CRISPR/Cas9, in particular, brought us closer to therapeutic gene editing for the treatment of cancer and hereditary diseases. Genome-editing therapies for blood disorders, blindness, and cancer are currently being evaluated in clinical trials. Eventually CRISPR/Cas9 technology is expected to target TP53 as the most mutated gene in all types of cancers. A majority of TP53 mutations are missense which brings immense opportunities for the CRISPR/Cas9 system that has been successfully used for correcting single nucleotides in various models, both in vitro and in vivo. In this review, we highlight the recent clinical applications of CRISPR/Cas9 technology for therapeutic genome editing and discuss its perspectives for editing TP53 and regulating transcription of p53 pathway genes

DNA Methylation in ATRA-treated Leukemia Cell Lines Lacking a PML-RAR Chromosome Translocation.

A deficient retinoic acid signaling has been suggested to be an important cause of the clinical inefficacy of all-trans retinoic acid (ATRA) therapy in non-promyelocytic (non-PML) forms of acute myeloid leukemia (AML). The general aim of the present work was to explore novel ways to take advantage of the anti-leukemic potential of ATRA, and, specifically, to search for a synergism between ATRA and epigenetic drugs. Because previous reports have found no major influence of ATRA on DNA methylation, we investigated whether ATRA-mediated differentiation of the U937 and HL-60 AML cell lines, both lacking a PML-retinoic acid receptor (RAR) fusion product, is accompanied by early-appearing and weak changes in CpG methylation. We report that in HL-60 cells, by using a highly quantitative analysis of a set of genes found to be abnormally expressed in AML, polymerase chain reaction (PCR)-amplified p16 gene promoter molecules (each with 15 CpG sites), exhibited a CpG methylation level of 0-4% in untreated cells, which increased to 4-21% after treatment with ATRA for seven days. In contrast to HL-60 cells, U937 cells exhibited a very high CpG methylation level in p16, and ATRA did not influence the promoter methylation of this gene. In the total CCGG sites of the genome, analysed using a methylation-sensitive restriction enzyme, CpG methylation was significantly lower in ATRA-treated HL-60 (p<0.01) and U937 cells (p<0.05) than in controls. Taken together, our findings show that ATRA can influence DNA methylation, and suggest that future research should investigate whether epigenetic modulation may evoke a clinical effect of ATRA in leukemia

Comparative cytotoxicity of kaolinite, halloysite, multiwalled carbon nanotubes and graphene oxide

This study aimed at comparative examining of the interactions between conventionally used clay and carbon nanomaterials and human lung adenocarcinoma cells (A549 cells). The following platy and tubular nanomaterials were tested: carbon nanoparticles, i.e. multi-walled carbon nanotubes (MWCNTs) and graphene oxide nanosheets (GO) as well as nanoclays, i.e. halloysite nanotubes (HNTs) and kaolinite nanosheets (Kaol). Nanoparticle physicochemical properties and their internalization into cells were examined using dynamic light scattering as well as atomic force, 3D laser scanning confocal and darkfield hyperspectral microscopies. Biological aspects of the nanomaterial-cell interaction included assessment of cellular toxicity, DNA damage, metabolic activity, and physical parameters of the cells. Regardless of a shape, carbon nanomaterials demonstrated cell surface adsorption, but negligible penetration into cells compared to nanoclays. However, carbon nanomaterials were found to be the most toxic for cells as probed by the MTS assay. They also turned out to be the most genotoxic for cells compared to nanoclays as revealed by the DNA-Comet assay. GO significantly increased the fraction of apoptotic cells and was the most cytotoxic and genotoxic nanomaterial. Comparison of flow cytometry and MTS data indicated that a cytotoxic effect of MWCNTs was not associated with increased cell death, but was rather due to a decrease in cell metabolic activity and/or proliferation. Finally, no significant effect of the shape of the tested nanomaterials on their internalization and cytotoxicity was revealed

A transient peak of infections during onset of rheumatoid arthritis: a 10-year prospective cohort study.

The role of infection in rheumatoid arthritis (RA) has not been determined. We aimed to document the infectious burden and some aspects of antibacterial immunity in a large and prospective cohort study of RA patients in the early and late stages of the disease and in their relatives predisposed to RA

Advancing CAR T-Cell Therapy for Solid Tumors: Lessons Learned from Lymphoma Treatment

Chimeric antigen receptor (CAR) immunotherapy is one of the most promising modern approaches for the treatment of cancer. To date only two CAR T-cell products, Kymriah&reg; and Yescarta&reg;, have been approved by the Food and Drug Administration (FDA) for the treatment of lymphoblastic leukemia and B-cell lymphoma. Administration of CAR T-cells to control solid tumors has long been envisaged as one of the most difficult therapeutic tasks. The first two clinical trials conducted in sarcoma and neuroblastoma patients showed clinical benefits of CAR T-cells, yet multiple obstacles still hold us back from having accessible and efficient therapy. Why did such an effective treatment for relapsed and refractory hematological malignancies demonstrate only relatively modest efficiency in the context of solid tumors? Is it due to the lucky selection of the &ldquo;magic&rdquo; CD19 antigen, which might be one of a kind? Or do lymphomas lack the immunosuppressive features of solid tumors? Here we review the existing knowledge in the field of CAR T-cell therapy and address the heterogeneity of solid tumors and their diverse strategies of immunoevasion. We also provide an insight into prospective developments of CAR T-cell technologies against solid tumors