The molecular basis for stability of heterochromatin-mediated silencing in mammals.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.The archetypal epigenetic phenomenon of position effect variegation (PEV) in Drosophila occurs when a gene is brought abnormally close to heterochromatin, resulting in stochastic silencing of the affected gene in a proportion of cells that would normally express it. PEV has been instrumental in unraveling epigenetic mechanisms. Using an in vivo mammalian model for PEV we have extensively investigated the molecular basis for heterochromatin-mediated gene silencing. Here we distinguish 'epigenetic effects' from other cellular differences by studying ex vivo cells that are identical, apart from the expression of the variegating gene which is silenced in a proportion of the cells. By separating cells according to transgene expression we show here that silencing appears to be associated with histone H3 lysine 9 trimethylation (H3K9me3), DNA methylation and the localization of the silenced gene to a specific nuclear compartment enriched in these modifications. In contrast, histone H3 acetylation (H3Ac) and lysine 4 di or tri methylation (H3K4me2/3) are the predominant modifications associated with expression where we see the gene in a euchromatic compartment. Interestingly, DNA methylation and inaccessibility, rather than H3K9me3, correlated most strongly with resistance to de-repression by cellular activation. These results have important implications for understanding the contribution of specific factors involved in the establishment and maintenance of gene silencing and activation in vivo.Peer Reviewe

A dominant-negative FGF1 mutant (the R50E mutant) suppresses tumorigenesis and angiogenesis.

Fibroblast growth factor-1 (FGF1) and FGF2 play a critical role in angiogenesis, a formation of new blood vessels from existing blood vessels. Integrins are critically involved in FGF signaling through crosstalk. We previously reported that FGF1 directly binds to integrin αvβ3 and induces FGF receptor-1 (FGFR1)-FGF1-integrin αvβ3 ternary complex. We previously generated an integrin binding defective FGF1 mutant (Arg-50 to Glu, R50E). R50E is defective in inducing ternary complex formation, cell proliferation, and cell migration, and suppresses FGF signaling induced by WT FGF1 (a dominant-negative effect) in vitro. These findings suggest that FGFR and αvβ3 crosstalk through direct integrin binding to FGF, and that R50E acts as an antagonist to FGFR. We studied if R50E suppresses tumorigenesis and angiogenesis. Here we describe that R50E suppressed tumor growth in vivo while WT FGF1 enhanced it using cancer cells that stably express WT FGF1 or R50E. Since R50E did not affect proliferation of cancer cells in vitro, we hypothesized that R50E suppressed tumorigenesis indirectly through suppressing angiogenesis. We thus studied the effect of R50E on angiogenesis in several angiogenesis models. We found that excess R50E suppressed FGF1-induced migration and tube formation of endothelial cells, FGF1-induced angiogenesis in matrigel plug assays, and the outgrowth of cells in aorta ring assays. Excess R50E suppressed FGF1-induced angiogenesis in chick embryo chorioallantoic membrane (CAM) assays. Interestingly, excess R50E suppressed FGF2-induced angiogenesis in CAM assays as well, suggesting that R50E may uniquely suppress signaling from other members of the FGF family. Taken together, our results suggest that R50E suppresses angiogenesis induced by FGF1 or FGF2, and thereby indirectly suppresses tumorigenesis, in addition to its possible direct effect on tumor cell proliferation in vivo. We propose that R50E has potential as an anti-cancer and anti-angiogenesis therapeutic agent ("FGF1 decoy")

Potential Role of the Intratumoral Microbiota in Prognosis of Head and Neck Cancer

The tumor microbiome, a relatively new research field, affects tumor progression through several mechanisms. The Cancer Microbiome Atlas (TCMA) database was recently published. In the present study, we used TCMA and The Cancer Genome Atlas and examined microbiome profiling in head and neck squamous cell carcinoma (HNSCC), the role of the intratumoral microbiota in the prognosis of HNSCC patients, and differentially expressed genes in tumor cells in relation to specific bacterial infections. We investigated 18 microbes at the genus level that differed between solid normal tissue (n = 22) and primary tumors (n = 154). The tissue microbiome profiles of Actinomyces, Fusobacterium, and Rothia at the genus level differed between the solid normal tissue and primary tumors of HNSCC patients. When the prognosis of groups with rates over and under the median for each microbe at the genus level was examined, rates for Leptotrichia which were over the median correlated with significantly higher overall survival rates. We then extracted 35 differentially expressed genes between the over- and under-the-median-for-Leptotrichia groups based on the criteria of >1.5 fold and p < 0.05 in the Mann–Whitney U-test. A pathway analysis showed that these Leptotrichia-related genes were associated with the pathways of Alzheimer disease, neurodegeneration-multiple diseases, prion disease, MAPK signaling, and PI3K-Akt signaling, while protein–protein interaction analysis revealed that these genes formed a dense network. In conclusion, probiotics and specific antimicrobial therapy targeting Leptotrichia may have an impact on the prognosis of HNSCC.Hamada M., Inaba H., Nishiyama K., et al. Potential Role of the Intratumoral Microbiota in Prognosis of Head and Neck Cancer. International Journal of Molecular Sciences 24, 15456 (2023); https://doi.org/10.3390/ijms242015456

Establishment of a new myeloid cell line with i(17q) as the sole chromosomal anomaly from the bone marrow of a patient with myelodysplastic syndrome

A new myeloid cell line, MTO-94, was established from the bone marrow of a patient with myelodysplastic syndrome (MDS). MTO-94 cells matured in culture medium without the addition of growth factors, and yielded neutrophils with pseudo-Pelger Hue&#776;t anomaly or hypersegmentation until 6 months. Ten months after the start of cell cultivation, MTO-94 consisted of myeloblasts. Surface phenotypes were as follows: CD7 90.3%, CD13 99.6%, CD33 75.6%, HLA-DR 96.3% and CD34 0.9%. The karyotype was 46, XY, i(17q). The proliferation of MTO-94 cells was enhanced by rhlL-3, G-CSF, rhGM-CSF and rhSCF but not by rhlL-6 and erythropoietin. MTO-94 cells with i(17q) might be useful in the study of biological aspects of not only MDS, but also hematological malignancies with i(17q) as the sole chromosomal anomaly.</p

Counseling for hemodialysis outpatients.

Maintenance hemodialysis outpatients must limit salt and water intake to maintain electrolyte balance and blood pressure. In Kawashima Hospital, nationally registered dietitians provide hemodialysis patients with monthly nutritional counseling. We investigated whether nutritional counseling affects interdialytic weight gain (IDWG) and blood pressure. We investigated 48 hemodialysis patients whose monthly average IDWG ratio to dry weight exceeded 5.1% and who had not had a long-term hospital admittance of ＞1 month. After the 48-month nutritional counseling period, the IDWG ratio had improved in 37 of the patients (77.1%), significantly decreasing from 6.0±0.7 to 5.3±0.9%. Estimated salt and water intake decreased significantly from 13.3±2.7 to 11.8±2.4 g/day and 2528±455 to 2332±410 ml/day, respectively. During the intervention period, normalized protein catabolic rate and body mass index did not change substantially. Pre-hemodialysis systolic and diastolic blood pressures had significantly decreased from 149±19 to 134±18 mmHg, and 82±13 to 75±10 mmHg for 48 months after study initiation, respectively. The dosage of antihypertensive drugs had significantly decreased in the group that experienced improvement in the IDWG ratio. Long-term nutritional counseling by nationally registered dietitians may improve the IDWG ratio and blood pressure of hemodialysis patients by decreasing their salt and water intake

Establishment of a New Cell Line(MTT-95) Showing Basophilic Differentiation from the Bone Marrow of a Patient with Acute Myelogenous Leukemia (M7)

A new myeloid cell line, MTT-95, was established from the bone marrow of a patient with acute myelogenous leukemia (AML, M7). MTT-95 cells differentiate into mature basophilic cells in culture medium with no chemical component or cytokine. Surface phenotypes were as follows: CD11b 79.3%, CD13 92.4%, CD33 99.8%, CD34 87.9%, CD41a 77.6% and HLA-DR 0.3%. MTT-95 cells were strongly positive for glycoprotein IIb/IIIa by immunohistochemical staining and revealed metachromatic granules. MTT-95 cells seem to possess characteristics of both megakaryocytes and basophils. These findings suggest that MTT-95 cells are basophil progenitors. MTT-95 cells might be useful in the study not only of the biological aspects of basophils, but also of the diversities of AML (M7).</p

Muscle mass, quality, and strength; physical function and activity; and metabolic status in cachectic patients with head and neck cancer

Background & aims: Cancer cachexia is commonly associated with poor prognosis in patients with head and neck cancer (HNC). However, its pathophysiology and treatment are not well established. The current study aimed to assess the muscle mass/quality/strength, physical function and activity, resting energy expenditure (REE), and respiratory quotient (RQ) in cachectic patients with HNC. Methods: This prospective cross-sectional study analyzed 64 patients with HNC. Body composition was measured via direct segmental multifrequency bioelectrical impedance analysis, and muscle quality was assessed using echo intensity on ultrasonography images. Muscle strength was investigated utilizing handgrip strength and isometric knee extension force (IKEF). Physical function was evaluated using the 10-mwalking speed test and the five times sit-to-stand (5-STS) test. Physical activity was examined using a wearable triaxial accelerometer. REE and RQ were measured via indirect calorimetry. These parameters were compared between the cachectic and noncachectic groups. Results: In total, 23 (36%) patients were diagnosed with cachexia. The cachectic group had a significantly lower muscle mass than the noncachectic group. Nevertheless, there was no significant difference in terms of fat between the two groups. The cachectic group had a higher quadriceps echo intensity and a lower handgrip strength and IKEF than the noncachectic group. Moreover, they had a significantly slower normal and maximum walking speed and 5 STS speed. The number of steps, total activity time, and time of activity (<3 Mets) did not significantly differ between the two groups. The cachectic group had a shorter time of activity (≥3 Mets) than the noncachectic group. Furthermore, the cachectic group had a significantly higher REE/body weight and REE/fat free mass and a significantly lower RQ than the noncachectic group. Conclusions: The cachectic group had a lower muscle mass/quality/strength and physical function and activity and a higher REE than the noncachectic group. Thus, REE and physical activity should be evaluated to determine energy requirements. The RQ was lower in the cachectic group than that in the noncachectic group, indicating changes in energy substrate. Further studies must be conducted to examine effective nutritional and exercise interventions for patients with cancer cachexia