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1.
Int J Mol Sci ; 20(8)2019 Apr 21.
Article in English | MEDLINE | ID: mdl-31010097

ABSTRACT

The majority of the human genome is made of transposable elements, giving rise to interspaced repeats, including Long INterspersed Element-1s (LINE-1s or L1s). L1s are active human transposable elements involved in genomic diversity and evolution; however, they can also contribute to genomic instability and diseases. L1s require host factors to complete their life cycles, whereas the host has evolved numerous mechanisms to restrict L1-induced mutagenesis. Restriction mechanisms in somatic cells include methylation of the L1 promoter, anti-viral factors and RNA-mediated processes such as small RNAs. microRNAs (miRNAs or miRs) are small non-coding RNAs that post-transcriptionally repress multiple target genes often found in the same cellular pathways. We have recently established that miR-128 functions as a novel restriction factor inhibiting L1 mobilization in somatic cells. We have further demonstrated that miR-128 functions through a dual mechanism; by directly targeting L1 RNA for degradation and indirectly by inhibiting a cellular co-factor which L1 is dependent on to transpose to new genomic locations (TNPO1). Here, we add another piece to the puzzle of the enigmatic L1 lifecycle. We show that miR-128 also inhibits another key cellular factor, hnRNPA1 (heterogeneous nuclear ribonucleoprotein A1), by significantly reducing mRNA and protein levels through direct interaction with the coding sequence (CDS) of hnRNPA1 mRNA. In addition, we demonstrate that repression of hnRNPA1 using hnRNPA1-shRNA significantly decreases de novo L1 retro-transposition and that induced hnRNPA1 expression enhances L1 mobilization. Furthermore, we establish that hnRNPA1 is a functional target of miR-128. Finally, we determine that induced hnRNPA1 expression in miR-128-overexpressing cells can partly rescue the miR-128-induced repression of L1's ability to transpose to different genomic locations. Thus, we have identified an additional mechanism by which miR-128 represses L1 retro-transposition and mediates genomic stability.


Subject(s)
Heterogeneous Nuclear Ribonucleoprotein A1/metabolism , Long Interspersed Nucleotide Elements/genetics , MicroRNAs/metabolism , RNA, Messenger/metabolism , Antagomirs/metabolism , Base Sequence , HeLa Cells , Heterogeneous Nuclear Ribonucleoprotein A1/antagonists & inhibitors , Heterogeneous Nuclear Ribonucleoprotein A1/genetics , Humans , MicroRNAs/antagonists & inhibitors , MicroRNAs/genetics , Open Reading Frames/genetics , RNA Interference , RNA, Small Interfering/metabolism , Sequence Alignment
2.
Oncotarget ; 9(17): 13244-13253, 2018 Mar 02.
Article in English | MEDLINE | ID: mdl-29568354

ABSTRACT

Telomerase is a unique cellular reverse transcriptase (RT) essential for maintaining telomere stability and required for the unlimited proliferation of cancer cells. The limiting determinant of telomerase activity is the catalytic component TERT, and TERT expression is closely correlated with telomerase activity and cancer initiation and disease progression. For this reason the regulation of TERT levels in the cell is of great importance. microRNAs (miRs) function as an additional regulatory level in cells, crucial for defining expression boundaries, proper cell fate decisions, cell cycle control, genome integrity, cell death and metastasis. We performed an anti-miR library screen to identity novel miRs, which participate in the control of telomerase. We identified the tumor suppressor miR (miR-128) as a novel endogenous telomerase inhibitor and determined that miR-128 significantly reduces the mRNA and protein levels of Tert in a panel of cancer cell lines. We further evaluated the mechanism by which miR-128 regulates TERT and demonstrated that miR-128 interacts directly with the coding sequence of TERT mRNA in both HeLa cells and teratoma cells. Interestingly, the functional miR-128 binding site in TERT mRNA, is conserved between TERT and the other cellular reverse transcriptase encoded by Long Interspersed Elements-1 (LINE-1 or L1), which can also contribute to the oncogenic phenotype of cancer. This finding supports the novel idea that miRs may function in parallel pathways to inhibit tumorigenesis, by regulating a group of enzymes (such as RT) by targeting conserved binding sites in the coding region of both enzymes.

3.
Diabetes Educ ; 43(1): 114-124, 2017 02.
Article in English | MEDLINE | ID: mdl-27831521

ABSTRACT

Purpose The purpose of this study was to examine the reliability and validity of a Spanish version of the Beliefs about Medicines Questionnaire (BMQ) as a measure to evaluate beliefs about medications and to differentiate adherent from nonadherent patients among low-income Latino patients with diabetes in the United States. Methods Seventy-three patients were administered the BMQ and surveyed for evidence of medication nonadherence. Internal consistency of the BMQ was assessed by Cronbach's alpha along with performing a confirmatory factor analysis. Criterion validity was assessed by comparing mean scores on 3 subscales of the BMQ (General Overuse, General Harm, and Specific Necessity-Concerns difference score) between adherent patients and patients reporting nonadherence for 3 different reasons (unintentional nonadherence, cost-related nonadherence, and nonadherence due to reasons other than cost) using independent samples t tests. Results The BMQ is a reliable instrument to examine beliefs about medications in this Spanish-speaking population. Construct validity testing shows nearly identical factor loading as the original construct map. General Overuse scores were significantly more negative for patients reporting each reason for nonadherence compared with their adherent counterparts. Necessity-Concerns difference scores were significantly more negative for patients reporting nonadherence for reasons other than cost compared with those who did not report this reason for nonadherence. Conclusion The Spanish version of the BMQ is appropriate to assess beliefs about medications in Latino patients with type 2 diabetes in the United States and may help identify patients who become nonadherent to medications for reasons other than out-of-pocket costs.


Subject(s)
Diabetes Mellitus, Type 2/psychology , Hispanic or Latino/psychology , Medication Adherence/psychology , Poverty/psychology , Surveys and Questionnaires/standards , Adult , Cross-Sectional Studies , Culture , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/ethnology , Female , Humans , Language , Male , Medication Adherence/ethnology , Middle Aged , Reproducibility of Results , Translations , United States
4.
Trials ; 16: 145, 2015 Apr 10.
Article in English | MEDLINE | ID: mdl-25873349

ABSTRACT

BACKGROUND: Low-income, Mexican-American patients with diabetes exhibit high rates of medication nonadherence, poor blood sugar control and serious complications, and often have difficulty communicating their concerns about the medication regimen to physicians. Interventions led by community health workers, non-professional community members who are trained to work with patients to improve engagement and communication during the medical visit, have had mixed success in improving outcomes. The primary objective of this project is to pilot test a prototype software toolkit called "EMPATHy" that a community health worker can administer to help patients identify the most important barriers to adherence that they face and discuss these barriers with their doctor. METHODS/DESIGN: The EMPATHy toolkit will be piloted in an ongoing intervention (Coached Care) in which community health workers are trained to be "coaches" to meet with patients before the medical visit and help them prepare a list of important questions for the doctor. A total of 190 Mexican-American patients with poorly controlled type 2 diabetes will be recruited from December 2014 through June 2015 and will be randomly assigned to complete either a single Coached Care intervention visit with no software tools or a Coached Care visit incorporating the EMPATHy software toolkit. The primary endpoints are (1) the development of a "contextualized plan of care" (i.e., a plan of care that addresses a barrier to medication adherence in the patient's daily life) with the doctor, determined from an audio recording of the medical visit, and (2) attainment of a concrete behavioral goal set during the intervention session, assessed in a 2-week follow-up phone call to the patient. The statistical analysis will include logistic regression models and is powered to detect a 50% increase in the primary endpoints. DISCUSSION: The study will provide evidence regarding the effectiveness and feasibility of a software tool to help patients communicate with doctors about problems they face with their medications. TRIAL REGISTRATION: ClinicalTrials.gov NCT02324036 Registered 16 December 2014.


Subject(s)
Communication , Community Health Workers , Diabetes Mellitus, Type 2/drug therapy , Health Knowledge, Attitudes, Practice , Hypoglycemic Agents/therapeutic use , Medication Adherence , Mexican Americans/psychology , Physician-Patient Relations , Software Design , Attitude of Health Personnel , California/epidemiology , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/ethnology , Drug Therapy, Combination , Empathy , Feasibility Studies , Female , Health Knowledge, Attitudes, Practice/ethnology , Health Status Disparities , Healthcare Disparities/ethnology , Humans , Male , Medication Adherence/ethnology , Patient Care Team , Patient Education as Topic , Pilot Projects , Research Design , Risk Factors , Time Factors , Treatment Outcome
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