Satellite cells are skeletal muscle stem cells capable of self-renewal and differentiation after transplantation, but whether they contribute to endogenous muscle fiber repair has been unclear. The transcription factor Pax7 marks satellite cells and is critical for establishing the adult satellite cell pool. By using a lineage tracing approach, we show that after injury, quiescent adult Pax7(+) cells enter the cell cycle; a subpopulation returns to quiescence to replenish the satellite cell compartment, while others contribute to muscle fiber formation. We demonstrate that Sprouty1 (Spry1), a receptor tyrosine kinase signaling inhibitor, is expressed in quiescent Pax7(+) satellite cells in uninjured muscle, downregulated in proliferating myogenic cells after injury, and reinduced as Pax7(+) cells re-enter quiescence. We show that Spry1 is required for the return to quiescence and homeostasis of the satellite cell pool during repair. Our results therefore define a role for Spry1 in adult muscle stem cell biology and tissue repair.
The van der Waerden theorem in Ramsey theory states that, for every k and t and sufficiently large N , every k -colouring of [N] contains a monochromatic arithmetic progression of length t . Motivated by this result, Radoičić conjectured that every equinumerous 3-colouring of [3 n ] contains a 3-term rainbow arithmetic progression, i.e. , an arithmetic progression whose terms are coloured with distinct colours. In this paper, we prove that every 3-colouring of the set of natural numbers for which each colour class has density more than 1/6, contains a 3-term rainbow arithmetic progression. We also prove similar results for colourings of . Finally, we give a general perspective on other anti-Ramsey-type problems that can be considered.
Supplementary Data from Acquired Resistance to EZH2 Inhibitor GSK343 Promotes the Differentiation of Human DLBCL Cell Lines toward an ABC-Like Phenotype
Supplementary Data from Acquired Resistance to EZH2 Inhibitor GSK343 Promotes the Differentiation of Human DLBCL Cell Lines toward an ABC-Like Phenotype
Abstract Abstract: Sarcopenia, a condition characterized by the loss of muscle mass, strength and function with age, is highly prevalent in cancer survivors. The relationship between sarcopenia and prognosis among cancer survivors is not well understood. Methods: From the Third National Health and Nutrition Examination Survey (NHANES III), we identified 946 participants who were diagnosed with cancer (mean age 60.6 years); the most common disease sites were breast, prostate, colon and melanoma. We assembled an age, sex and race-matched cohort of 1,857 participants without cancer (mean age, 60.2 years). Sarcopenia was defined by appendicular lean mass and body height (men <7.26 kg/m2, women <5.45 kg/m2). Proportional-hazard models were used to assess whether sarcopenia was associated with all cause and CVD-specific time to death after taking into account baseline age, sex, race/ethnicity, smoking status, and energy intake for each cohort. In the cancer survivor cohort, models were additionally adjusted for a history of having more than one cancer and time since diagnosis. Mortality was ascertained from the National Center for Health Statistics Linked Mortality Files. Results: There were 321 deaths among cancer survivors (33.9% of the cohort) during a median follow-up of 10.5 years versus 495 deaths among participants without cancer (26.7% of the cohort) during a median follow-up of 10.9 years. Deaths from cardiovascular disease (CVD) were observed in 58 (6.1%) cancer survivors versus 122 (6.6%) participants without cancer. Overall, sarcopenia was more prevalent among cancer survivors versus the matched cohort (22.2% versus 19.7% respectively). Rates of CVD death were more than twice higher among cancer survivors with versus without sarcopenia (adjusted hazard ratio, 2.17, 95% confidence interval [CI], 1.16 to 4.05). All-cause mortality was 79% higher (adjusted hazard ratio, 1.79; 95% CI, 1.36 to 2.36) among cancer survivors with versus without sarcopenia. No significant associations were seen between sarcopenia and rates of death from all causes and CVD specifically among participants without cancer. Conclusion: Cancer survivors with sarcopenia have an increased risk of all-cause and CVD-specific mortality. In contrast, sarcopenia was not a major predictor of these outcomes in the matched cohort without cancer. Citation Format: Dejana Braithwaite, Shama Karanth, Christiaan Leeuwenburgh, Todd M. Manini, Meghann Wheeler, Danting Yang, Livingstone Aduse-Poke, Stephen Anton, Frank Penedo, Erin M. Siegel, Jonathan D. Licht, Dongyu Zhang. Elevated all-cause and cardiovascular mortality in cancer survivors with sarcopenia [abstract]. In: Proceedings of the AACR Special Conference: Aging and Cancer; 2022 Nov 17-20; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_1):Abstract nr B001.
Eradication of acute promyelocytic leukemia (APL) in mice depends on two events: derepressing the differentiation pathway and ridding the APL cell of the fusion oncoprotein that sustains it.
