Protein kinase CK2 promotes cancer cell viability via up-regulation of cyclooxygenase-2 expression and enhanced prostaglandin E2 production

Augmented expression of protein kinase CK2 is associated with hyperproliferation and resistance to apoptosis in cancer cells. Effects of CK2 are at least partially linked to signaling via the Wnt/β-catenin pathway, which is dramatically enhanced in colon cancer. Cyclooxygenase-2 (COX-2), a Wnt/β-catenin target gene, has been associated with enhanced cancer progression and metastasis. However, the possibility that a connection may exist between CK2 and COX-2 has not been explored previously. Here we investigated changes in COX-2 expression and activity upon CK2 modulation and evaluated how these changes affected cell viability. COX-2 expression and cell viability decreased upon selective inhibition of COX-2 with SC-791 or CK2 with 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT), both in human colon (HT29-ATCC, HT29-US, DLD-1) and breast (ZR-75) cancer cells, as well as in human embryonic kidney (HEK-293T) cells. On the other hand, ectopic CK2α expression promoted up-regulation of COX-2 by activating the Wnt/β-catenin pathway in HEK-293T cells. Noteworthy, over-expression of either CK2α, β-catenin or COX-2, as well as supplementation of the medium with prostaglandin E2 (PGE2), all were individually sufficient to overcome limitations in cell viability triggered by CK2 inhibition either upon addition of DMAT or over-expression of a dominant negative CK2α variant. Altogether, these findings provide new insight to the role of CK2 in cancer by up-regulating COX-2 expression and thereby PGE2 production.     

A reference-quality,fully annotated genome from a Puerto Rican individual

Until 2019, the human genome was available in only one fully annotated version, GRCh38, which was the result of 18 years of continuous improvement and revision. Despite dramatic improvements in sequencing technology, no other genome was available as an annotated reference until 2019, when the genome of an Ashkenazi individual, Ash1, was released. In this study, we describe the assembly and annotation of a second individual genome, from a Puerto Rican individual whose DNA was collected as part of the Human Pangenome project. The new genome, called PR1, is the first true reference genome created from an individual of African descent. Due to recent improvements in both sequencing and assembly technology, and particularly to the use of the recently completed CHM13 human genome as a guide to assembly, PR1 is more complete and more contiguous than either GRCh38 or Ash1. Annotation revealed 37,755 genes (of which 19,999 are protein coding), including 12 additional gene copies that are present in PR1 and missing from CHM13. Fifty-seven genes have fewer copies in PR1 than in CHM13, 9 map only partially, and 3 genes (all noncoding) from CHM13 are entirely missing from PR1.     

Olomoucine II,but Not Purvalanol A,Is Transported by Breast Cancer Resistance Protein (ABCG2) and P-Glycoprotein (ABCB1)

Purine cyclin-dependent kinase inhibitors have been recognized as promising candidates for the treatment of various cancers; nevertheless, data regarding interaction of these substances with drug efflux transporters is still lacking. Recently, we have demonstrated inhibition of breast cancer resistance protein (ABCG2) by olomoucine II and purvalanol A and shown that these compounds are able to synergistically potentiate the antiproliferative effect of mitoxantrone, an ABCG2 substrate. In this follow up study, we investigated whether olomoucine II and purvalanol A are transported by ABCG2 and ABCB1 (P-glycoprotein). Using monolayers of MDCKII cells stably expressing human ABCB1 or ABCG2, we demonstrated that olomoucine II, but not purvalanol A, is a dual substrate of both ABCG2 and ABCB1. We, therefore, assume that pharmacokinetics of olomoucine II will be affected by both ABCB1 and ABCG2 transport proteins, which might potentially result in limited accumulation of the compound in tumor tissues or lead to drug-drug interactions. Pharmacokinetic behavior of purvalanol A, on the other hand, does not seem to be affected by either ABCG2 or ABCB1, theoretically favoring this drug in the potential treatment of efflux transporter-based multidrug resistant tumors. In addition, we observed intensive sulfatation of olomoucine II in MDCKII cell lines with subsequent active efflux of the metabolite out of the cells. Therefore, care should be taken when performing pharmacokinetic studies in MDCKII cells, especially if radiolabeled substrates are used; the generated sulfated conjugate may largely contaminate pharmacokinetic analysis and result in misleading interpretation. With regard to chemical structures of olomoucine II and purvalanol A, our data emphasize that even drugs with remarkable structure similarity may show different pharmacokinetic behavior such as interactions with ABC transporters or biotransformation enzymes.     

The Process-inducing Activity of Transmembrane Agrin Requires Follistatin-like Domains

Clustering or overexpression of the transmembrane form of the extracellular matrix proteoglycan agrin in neurons results in the formation of numerous highly motile filopodia-like processes extending from axons and dendrites. Here we show that similar processes can be induced by overexpression of transmembrane-agrin in several non-neuronal cell lines. Mapping of the process-inducing activity in neurons and non-neuronal cells demonstrates that the cytoplasmic part of transmembrane agrin is dispensable and that the extracellular region is necessary for process formation. Site-directed mutagenesis reveals an essential role for the loop between β-sheets 3 and 4 within the Kazal subdomain of the seventh follistatin-like domain of TM-agrin. An aspartic acid residue within this loop is critical for process formation. The seventh follistatin-like domain could be functionally replaced by the first and sixth but not by the eighth follistatin-like domain, demonstrating a functional redundancy among some follistatin-like domains of agrin. Moreover, a critical distance of the seventh follistatin-like domain to the plasma membrane appears to be required for process formation. These results demonstrate that different regions within the agrin protein are responsible for synapse formation at the neuromuscular junction and for process formation in central nervous system neurons and suggest a role for agrin''s follistatin-like domains in the developing central nervous system.     

Mutagenic effects of short term action of N-methyl-N’-nitro-N-nitrosoguanidine onChlamydomonas geitleri

A possible method of finding the best concentration of a chemical mutagen or a shortterm action is demonstrated by the results obtained withChlamydomonas geitleri. Mostly two cases occur. We must either use the shortest time of the mutagen action with a sufficiently high effect or utilize the whole limited time for this action using a suitable concentration with a similar effect. It is possible to choose such a structure of the doae of the chemical mutagen which in the mutation spectrum ensures either the optimal frequencies of all components or of only some of them chosen beforehand.     

The mode of action of Aescin and the release of prostaglandins

The horse-chestnut saponin Aescin, an anti-exudative compound, induces contraction of isolated portal vein of rat and rabbit. This effect appears to be mediated by Prostaglandins of F_α type.The ability of Aescin to stimulate generation and release of Prostaglandins has been demonstrated in isolated lung of the rat. Mass-fragmentographic analysis of the lung effluent indicate that when Aescin is perfused through this organ the release of PGF_2α is increased. The capability of Aescin to generate Prostaglandins is discussed in connection with its anti-exudative activity.     

Mouse model systems of autism spectrum disorder: Replicability and informatics signature

Phenotyping mouse model systems of human disease has proven to be a difficult task, with frequent poor inter‐ and intra‐laboratory replicability, particularly in behavioral domains such as social and cognitive function. However, establishing robust animal model systems with strong construct validity is of fundamental importance as they are central tools for understanding disease pathophysiology and developing therapeutics. To complete our studies of mouse model systems relevant to autism spectrum disorder (ASD), we present a replication of the main findings from our two published studies of five genetic mouse model systems of ASD. To assess the intra‐laboratory robustness of previous results, we chose the two model systems that showed the greatest phenotypic differences, the Shank3/F and Cntnap2, and repeated assessments of general health, activity and social behavior. We additionally explored all five model systems in the same framework, comparing all results obtained in this three‐yearlong effort using informatics techniques to assess commonalities and differences. Our results showed high intra‐laboratory replicability of results, even for those with effect sizes that were not particularly large, suggesting that discrepancies in the literature may be dependent on subtle but pivotal differences in testing conditions, housing enrichment, or background strains and less so on the variability of the behavioral phenotypes. The overall informatics analysis suggests that in our behavioral assays we can separate the set of tested mouse model system into two main classes that in some aspects lie on opposite ends of the behavioral spectrum, supporting the view that autism is not a unitary concept.