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Colorectal cancer (CRC) is the most common gastrointestinal malignancy in the U.S.A. and approximately 50% of patients develop metastatic disease (mCRC). Despite our understanding of long non-coding RNAs (lncRNAs) in primary colon cancer, their role in mCRC and treatment resistance remains poorly characterized. Therefore, through transcriptome sequencing of normal, primary, and distant mCRC tissues we find 148 differentially expressed RNAs Associated with Metastasis ( RAMS ). We prioritize RAMS11 due to its association with poor disease-free survival and promotion of aggressive phenotypes in vitro and in vivo. A FDA-approved drug high-throughput viability assay shows that elevated RAMS11 expression increases resistance to topoisomerase inhibitors. Subsequent experiments demonstrate RAMS11 -dependent recruitment of Chromobox protein 4 (CBX4) transcriptionally activates Topoisomerase II alpha (TOP2α ) . Overall, recent clinical trials using topoisomerase inhibitors coupled with our findings of RAMS11- dependent regulation of TOP2α supports the potential use of RAMS11 as a biomarker and therapeutic target for mCRC. The role of long non-coding RNAs (lncRNAs) in metastatic colorectal cancer (mCRC) and treatment resistance is unclear. Here, the authors use transcriptome sequencing of matched normal, primary, and metastatic CRC tissues to discover and validate that lncRNA RAMS11 promotes metastasis and resistance to topoisomerase inhibitors in mCRC.

George Daley and colleagues show that Lin28 and Lin28B promote cellular transformation by repressing let-7 family members, leading to derepression of let-7 targets. They also find that LIN28 and LIN28B are overexpressed in ∼15% of primary human tumors and cancer cell lines and that their expression is associated with aggressive disease and poor prognosis across multiple tumor types. Multiple members of the let-7 family of miRNAs are often repressed in human cancers 1 , 2 , thereby promoting oncogenesis by derepressing targets such as HMGA2, K-Ras and c-Myc 3 , 4 . However, the mechanism by which let-7 miRNAs are coordinately repressed is unclear. The RNA-binding proteins LIN28 and LIN28B block let-7 precursors from being processed to mature miRNAs 5 , 6 , 7 , 8 , suggesting that their overexpression might promote malignancy through repression of let-7. Here we show that LIN28 and LIN28B are overexpressed in primary human tumors and human cancer cell lines (overall frequency ∼15%), and that overexpression is linked to repression of let-7 family miRNAs and derepression of let-7 targets. LIN28 and LIN28b facilitate cellular transformation in vitro , and overexpression is associated with advanced disease across multiple tumor types. Our work provides a mechanism for the coordinate repression of let-7 miRNAs observed in a subset of human cancers, and associates activation of LIN28 and LIN28B with poor clinical prognosis.

Background Adverse social exposome (indexed by high national Area Deprivation Index [ADI]) is linked to structural inequities and increased risk of clinical dementia diagnosis, yet linkage to ADRD neuropathology remains largely unknown. Early work from single site brain banks suggests a relationship, but assessment in large national cohorts is needed to increase generalizability and depth, particularly for rarer neuropathology findings. Objective Determine the association between adverse social exposome by ADI and ADRD neuropathology for brain donors from 21 Alzheimer’s Disease Research Center (ADRC) brain banks as part of the on‐going Neighborhoods Study. Methods All brain donors in participating sites with neuropathology data deposited at the National Alzheimer’s Coordinating Center (NACC) and identifiers for ADI linkage (N = 8,637; Figure 1) were included. Geocoded donor addresses were linked to time‐concordant national ADI percentiles for year of death, categorized into standard groupings of low (ADI 1‐19), medium (20‐49) and high (50‐100) ADI. Neuropathological findings were drawn from NACC and reflected standard assessment practices at time of donation. Logistic regression models, adjusted for sex and age at death, assessed relationships between high ADI and neuropathology findings. Results Of the N = 8,637 brain donors (Table 1), 2,071 of 2,366 assessed (88%) had AD pathology by NIA‐AA criteria; 4,197 of 6,929 assessed (61%) had cerebral amyloid angiopathy; 2582 of 8092 assessed (32%) had Lewy body pathology; 391 of 2351 assessed (17%) had non‐AD tauopathy; and 586 of 1680 assessed (35%) had TDP‐43 pathology. 2,126(25%) were high ADI; 3,171(37%) medium ADI and 3,340(38%) low ADI with 51% female and average age at death of 81.9 years. As compared to low ADI donors, high ADI brain donors had adjusted odds = 1.35 (95% CI = 0.98‐1.86, p‐value = 0.06) for AD pathology; 1.10 (0.98–1.25, p = 0.11) for cerebral amyloid angiopathy; 1.37 (1.21–1.55, p<0.01) for Lewy body; 1.09 (0.83–1.44, p = 0.53) for non‐AD tauopathy; and 1.40 (1.08‐1.81, p = 0.01) for TDP‐43 pathology (Table 2). Conclusions This first‐in‐field study provides evidence that the adverse social exposome (high ADI) is strongly associated with an increased risk of Lewy body, an increased risk of TDP‐43, and a trend towards increased AD pathology in a national cohort of brain donors.

Background Adverse social exposome (indexed by national Area Deprivation Index [ADI] 80‐100 or ‘high ADI’) is linked to structural inequities and increased risk of Alzheimer’s disease neuropathology. Twenty percent of the US population resides within high ADI areas, predominantly in inner cities, tribal reservations and rural areas. The percentage of brain donors from high ADI areas within the Alzheimer’s Disease Research Center (ADRC) brain bank system is unknown. Objective Determine ADI for brain donors from 21 ADRC sites as part of the on‐going Neighborhoods Study. Methods All brain donors in participating ADRC sites with NACC neuropathology data and personal identifiers for ADI linkage (N = 8,637) were included (Figure 1). Geocoded donor addresses were linked to time‐concordant ADI percentiles for year of death. Results Overall, only 5.6% of ADRC brain donors (N = 488) resided in a high ADI (disadvantaged) neighborhood at death. The remaining donors resided in more advantaged neighborhoods, with nearly 40% of donors living in the wealthiest quintile of neighborhoods, and over 300 brain donors originating from the wealthiest 1% of US neighborhoods (Figure 2). Donors from high ADI (disadvantaged) neighborhoods identified as 87% White (n = 424), 11% Black (55), 1% Multiracial (6) and <1% other/unknown race (3), with 1% Hispanic (5). None identified as American Indian/Alaska Native or Native Hawaiian/Pacific Islander/Asian. In comparison, donors from low ADI neighborhoods were 94% White (n = 7680), 3% Black (273), 1% Multiracial (75), <1% American Indian/Alaska Native (11), <1% Native Hawaiian/Pacific Islander/Asian (60), and <1% other/unknown race (50), with 3% Hispanic (230). Sex distribution was similar (54%, 51% female, respectively). Inclusion of high ADI donors varied dramatically across the 21 ADRC brain banks from a low of 0.6% to high of 20% of all a site’s donors (Figure 3). Conclusions ADI was determined for over 8,600 brain donors in the ADRC system, demonstrating a marked over‐representation of donors from very low ADI (extremely wealthy) neighborhoods, in addition to site‐to‐site variability. This is the first time a comprehensive cross‐sectional social exposome assessment of this nature has been performed, opening windows for additional mechanistic study of the social exposome on brain pathology. Life course ADI assessments are on‐going.

Sedentary behavior has been proposed as an independent cardio-metabolic risk factor even in adults who are physically active through recreational activity. Because little is known about the metabolic effects of sedentariness in seniors, the relationship between sedentary behavior and cardio-metabolic risk was examined in physically active older adults. Fifty-four community dwelling men and women > 65 years of age (mean 71.5 years) were enrolled in this cross-sectional observational study. Subjects were in good health and free of known diabetes. Activity levels (sedentary, light, moderate to vigorous activity time per day) were recorded with accelerometers worn continuously for 7 days. Cardio-metabolic risk factors measured consisted of the American Heart Association diagnostic criteria for metabolic syndrome (waist circumference, triglycerides, high-density lipoprotein, systolic blood pressure and fasting glucose) as well as low-density lipoprotein (LDL). The relationships between activity measures and cardio-metabolic risk factors were examined. Significant variables were then entered into a stepwise multivariate regression model. All but one subject achieved exercise levels recommended by the American College of Sports Medicine. The average proportion of time spent at a sedentary activity level each day was 72.7%. From the regression analysis, the only significant association found between cardio-metabolic risk outcomes and activity predictors was between LDL and sedentary time, with LDL detrimentally associated with average sedentary time per day (Standardized Beta Correlation Coefficient 0.302, p < 0.05). Sedentary behavior is associated with an adverse metabolic effect on LDL in seniors, even those who meet guideline recommendations for an active \"fit\" adult.

Multiple members of the let-7 family of miRNAs are often repressed in human cancers1,2, thereby promoting oncogenesis by de-repressing the targets K-Ras, c-Myc, and HMGA2 3,4. However, the mechanism by which let-7 miRNAs are coordinately repressed is unclear. The RNA-binding proteins Lin28 and Lin28B block let-7 precursors from being processed to mature miRNAs5–8, suggesting that over-expression of Lin28/Lin28B might promote malignancy via repression of let-7. Here we show that LIN28 and LIN28B are over-expressed in primary human tumors and human cancer cell lines (overall frequency ∼15%), and that over-expression is linked to repression of let-7 family miRNAs and de-repression of let-7 targets. Lin28/Lin28B facilitate cellular transformation in vitro, and over-expression is associated with advanced disease across multiple tumor types. Our work provides a mechanism for the coordinate repression of let-7 miRNAs observed in a subset of human cancers, and associates activation of LIN28/LIN28B with poor clinical prognosis.