Accumulating evidence suggests a role for microRNAs in human carcinogenesis as novel types of tumor suppressors or oncogenes. However, their precise biological role remains largely elusive. In the ...present study, we aimed to identify microRNA species involved in the regulation of cell proliferation. Using quantitative RT-PCR analysis, we demonstrated that miR-34a was highly up-regulated in a human colon cancer cell line, HCT 116, treated with a DNA-damaging agent, adriamycin. Transient introduction of miR-34a into two human colon cancer cell lines, HCT 116 and RKO, caused complete suppression of cell proliferation and induced senescence-like phenotypes. Moreover, miR-34a also suppressed in vivo growth of HCT 116 and RKO cells in tumors in mice when complexed and administered with atelocollagen for drug delivery. Gene-expression microarray and immunoblot analyses revealed down-regulation of the E2F pathway by miR-34a introduction. Up-regulation of the p53 pathway was also observed. Furthermore, 9 of 25 human colon cancers (36%) showed decreased expression of miR-34a compared with counterpart normal tissues. Our results provide evidence that miR-34a functions as a potent suppressor of cell proliferation through modulation of the E2F signaling pathway. Abrogation of miR-34a function could contribute to aberrant cell proliferation, leading to colon cancer development.
Exosomal microRNAs (miRNAs) have been attracting major interest as potential diagnostic biomarkers of cancer. The aim of this study was to characterize the miRNA profiles of serum exosomes and to ...identify those that are altered in colorectal cancer (CRC). To evaluate their use as diagnostic biomarkers, the relationship between specific exosomal miRNA levels and pathological changes of patients, including disease stage and tumor resection, was examined.
Microarray analyses of miRNAs in exosome-enriched fractions of serum samples from 88 primary CRC patients and 11 healthy controls were performed. The expression levels of miRNAs in the culture medium of five colon cancer cell lines were also compared with those in the culture medium of a normal colon-derived cell line. The expression profiles of miRNAs that were differentially expressed between CRC and control sample sets were verified using 29 paired samples from post-tumor resection patients. The sensitivities of selected miRNAs as biomarkers of CRC were evaluated and compared with those of known tumor markers (CA19-9 and CEA) using a receiver operating characteristic analysis. The expression levels of selected miRNAs were also validated by quantitative real-time RT-PCR analyses of an independent set of 13 CRC patients.
The serum exosomal levels of seven miRNAs (let-7a, miR-1229, miR-1246, miR-150, miR-21, miR-223, and miR-23a) were significantly higher in primary CRC patients, even those with early stage disease, than in healthy controls, and were significantly down-regulated after surgical resection of tumors. These miRNAs were also secreted at significantly higher levels by colon cancer cell lines than by a normal colon-derived cell line. The high sensitivities of the seven selected exosomal miRNAs were confirmed by a receiver operating characteristic analysis.
Exosomal miRNA signatures appear to mirror pathological changes of CRC patients and several miRNAs are promising biomarkers for non-invasive diagnosis of the disease.
Cancers arising from the biliary tract are refractory to conventional therapies, requiring the development of novel therapeutics. However, only a limited number of genetically engineered mouse models ...have been created, partly because of time-consuming work required. Besides, liver-specific gene manipulation mostly resulted in concurrent development of hepatocellular carcinoma, another type of liver cancer, and gallbladder-restricted gene targeting is still not feasible. Consequently, establishment of cancer type-specific disease modeling remains a technical challenge. To address this issue, we took an alternative cell-based approach to quickly induce tumorigenesis ex vivo. Specifically, murine primary organoids from liver and gallbladder were transduced with lentiviral vectors to reconstitute genetic alterations common in biliary tract cancers, followed by inoculation in immunodeficient mice. Although any single genetic alteration did not induce tumors, mutant Kras and repression of major tumor suppressors cooperated for tumor development within 2 months. Induced lesions varied among normal, dysplastic and papillary lesions to adenocarcinoma, recapitulating multistep tumorigenesis even in a heterotopic situation. We further demonstrated that two putative oncogenes in intrahepatic cholangiocellular carcinoma, mutant Pik3ca and FGFR2-AHCYL1 fusion, were rather modest drivers for liver-derived organoids, probably requiring additional mutations or hepatic niche to robustly induce full-blown tumors. Thus, we showed that cancer cells could be readily generated from primary cells in the biliary tract, at least in cases where genetic factors play dominant roles. Collectively, this study will likely contribute to gaining mechanistic insights into biliary carcinogenesis and providing valuable resources for drug discovery.
Social trust in medical students is trust in the cluster of medical students and not individual medical students. Social trust in medical students seems critical in clinical practice since citizens ...often face unknown medical students for the first time. However, most previous research has focused on interpersonal trust in particular medical professions, and social trust in medical students has not been addressed sufficiently. In social science, the Salient Value Similarity model has demonstrated that the value similarity between professionals and citizens is associated with social trust. This research aimed to explore the relationship between social trust in medical students and the perception of value similarity. This study also aimed to determine whether the information of medical students strengthens social trust in them.
We conducted a cross-sectional study to investigate how the perception of value similarity affects social trust. The participants answered the social trust questionnaires before and after reading a brief summary of the medical education curriculum and certification via the internet in Japan. The model structure of social trust in medical students, including the perception of value similarity, was investigated using SEM. A paired t-test was used to examine the effect of informing citizens about the knowledge, skills, and professionalism requirements of students attending medical school on social trust by reading the brief summary.
The study included 658 participants, who all answered a web questionnaire. Social trust in medical students was associated with the perception of ability and value similarity. Social trust in medical students, the perception of ability, and value similarity were improved by information about medical students.
The perception of ability and value similarity seem to affect social trust in medical students. Information on medical education regarding the knowledge, skills, and professionalism of medical students may improve social trust in these students. Further research is required to sophisticate the model of social trust in medical students by exploring social trust in the medical students' supervisors in clinical settings.
Objective Vaccination technique is a crucial skill for medical trainees to learn, especially in the current coronavirus disease 2019 pandemic. To this end, validated assessment tools are essential in ...teaching appropriate techniques. However, valid instruments for assessing vaccine administration skills have not yet been developed. We therefore explored the development and validation of an assessment tool for vaccination techniques based on expert consensus. Methods We implemented a modified Delphi process to develop a vaccination technique assessment tool. We then conducted a validation study to establish the reliability and validity of the tool. Results Two rounds of the modified Delphi process were performed to generate a 19-item, vaccination performance assessment checklist. In the validation study, the linear weighted kappa value for inter-rater reliability of the overall checklist score was 0.725. Spearman's correlation coefficient between the mean checklist score and the global rating was 0.98 (p<0.01). Conclusions This is a pioneering study examining the development and validation of an assessment tool for vaccine administration techniques. The tool will be widely used in vaccination-related education.
Introduction
An understanding of social determinants of health (SDH) and patients' social circumstances is recommended to deliver contextualised care. However, the processes of patient care related ...to SDH in clinical settings have not been described in detail. Observable practice activities (OPAs) are a collection of learning objectives and activities that must be observed in daily practice and can be used to describe the precise processes for professionals to follow in specific situations (process OPA.)
Methods
We used a modified Delphi technique to generate expert consensus about the process OPA for patient care related to SDH in primary care settings. To reflect the opinions of various stakeholders, the expert panel comprised clinical professionals (physicians, nurses, public health nurses, social workers, pharmacists and medical clerks), residents, medical students, researchers (medical education, health care, sociology of marginalised people), support members for marginalised people and patients. The Delphi rounds were conducted online. In Round 1, a list of potentially important steps in the processes of care was distributed to panellists. The list was modified, and one new step was added. In Round 2, all steps were acknowledged with few modifications.
Results
Of 63 experts recruited, 61 participated, and all participants completed the Delphi rounds. A total of 14 observable steps were identified, which were divided into four components: communication, practice, maintenance and advocacy. The importance of ongoing patient–physician relationships and collaboration with professionals and stakeholders was emphasised for the whole process of care.
Discussion
This study presents the consensus of a variety of experts on the process OPA for patient care related to SDHs. Further research is warranted to investigate how this Communication–Practice–Maintenance–Advocacy framework could affect medical education, quality of patient care, and patient outcomes.
This study illustrates a means of improving curricula by showing the Communication‐Practice‐Maintenance‐Advocacy (CPMA) framework to be useful for incorporating social determinants of health into healthcare to enhance education.
Objective The Mini-Z 2.0 is a new, simple, and nonproprietary tool for assessing physician well-being and burnout. To date, a non-English version of the Mini-Z 2.0 survey has not been validated. ...Therefore, we aimed to develop a Japanese version of the Mini-Z 2.0 and to evaluate its validity and reliability using survey data from physicians affiliated with an internal medicine academic society. Methods The Mini-Z 2.0 survey was translated into Japanese using a forward-backward translation method. The participants belonged to the American College of Physicians' Japan Chapter. The translated version of the Mini-Z 2.0 survey was distributed to participants using an electronic mailing list. Convergent validity was assessed between burnout and other items using Pearson's product-moment statistic. Structural validity was evaluated using an exploratory factor analysis and confirmatory factor analysis, and reliability was assessed using internal consistency. Results Of the 1,255 physicians and medical residents contacted, 283 responded (22.5%). Burnout was present in 34.6% of the participants, with 48.8% reporting high stress levels. Convergent validity was demonstrated, with satisfactory correlations between burnout and satisfaction, value alignment, work control, and stress. An exploratory factor analysis identified two factors (i.e., Well-Being and Relationships and Work-Related Stressors); however, the three models evaluated using the confirmatory factor analysis revealed a poor fit. Cronbach's alpha for the sample was 0.80. Conclusion The Japanese version of the Mini-Z 2.0 demonstrated good internal consistency and convergent validity. Despite its inadequate structural validity, it can be used to measure physician well-being and related workplace conditions in Japan.
Objective To evaluate the change in the prevalence of burnout during the COVID-19 pandemic among internists and primary care physicians in Japan, and to identify factors associated with the ...exacerbation of burnout among these populations during this period. Methods This was a cross-sectional study based on two web-based surveys conducted in January 2020 (before the declaration of the COVID-19 pandemic) and June 2020 (during the pandemic). The participants were internists and primary care physicians of the Japanese Chapter of the American College of Physicians. The main outcome was the change in the prevalence of burnout between before and during the "first wave" of the pandemic. We also examined factors associated with the exacerbation of burnout during this period. Results Among the 283 respondents in the first survey and 322 in the second survey, 98 (34.6%) and 111 (34.5%) reported symptoms of burnout, respectively. In June 2020, 82 respondents (25.5%) reported that their level of burnout exacerbated compared to January 2020. Only the experience of self-quarantine was associated with the exacerbation of burnout odds ratio (OR) 3.12; 95% confidence interval (CI) 1.49-6.50; p=0.002, while being a woman, being a resident physician, and an experience of having worked in a prefecture under a state of emergency were not. Conclusions No marked change in the prevalence of burnout among internists and primary care physicians in Japan was observed during the COVID-19 pandemic as a whole. However, self-quarantine was associated with the exacerbation of the burnout level.
Epithelial cells in the biliary system can develop refractory types of cancers, which are often associated with inflammation caused by viruses, parasites, stones, and chemicals. Genomic studies have ...revealed recurrent genetic changes and deregulated signaling pathways in biliary tract cancer (BTC). The causal roles have been at least partly clarified using various genetically engineered mice. Technical advances in Cre-LoxP technology, together with hydrodynamic tail injection, CRISPR/Cas9 technology, in vivo electroporation, and organoid culture have enabled more precise modeling of BTC. Organoid-based genetic modeling, combined with implantation in mice, has recently drawn attention as a means to accelerate the development of BTC models. Although each model may not perfectly mimic the disease, they can complement one another, or two different approaches can be integrated to establish a novel model. In addition, a comparison of the outcomes among these models with the same genotype provides mechanistic insights into the interplay between genetic alterations and the microenvironment in the pathogenesis of BTCs. Here, we review the current status of genetic models of BTCs in mice to provide information that facilitates the wise selection of models and to inform the future development of ideal disease models.
Abstract
The organoid culture technique has been recently applied to modeling carcinogenesis in several organs. To further explore its potential and gain novel insights into tumorigenesis, we here ...investigated whether pancreatic ductal adenocarcinoma (PDA) could be generated as subcutaneous tumors in immunocompromised nude mice, by genetic engineering of normal organoids. As expected, acute induction of KrasG12Din vitro occasionally led to development of tiny nodules compatible with early lesions known as pancreatic intraepithelial neoplasia (PanIN). KrasG12D-expressing cells were enriched after inoculation in the subcutis, yet proved rather declined during culture, suggesting that its advantage might depend on surrounding environments. Depletion of growth factors or concurrent Trp53 deletion resulted in its robust enrichment, invariably leading to development of PanIN or large high-grade adenocarcinoma, respectively, consistent with in vivo mouse studies for the same genotype. Progression from PanIN was also recapitulated by subsequent knockdown of common tumor suppressors, whereas the impact of Tgfbr2 deletion was only partially recapitulated, illustrating genotype-dependent requirement of the pancreatic niche for tumorigenesis. Intriguingly, analysis of tumor-derived organoids revealed that KrasG12D-expressing cells with spontaneous deletion of wild-type Kras were positively selected and exhibited an aging-related mutation signature in nude mice, mirroring the pathogenesis of human PDA, and that the sphere-forming potential and orthotopic tumorigenicity in syngenic mice were significantly augmented. These observations highlighted the relevance of the subcutis of nude mice in promoting PDA development despite its ectopic nature. Taken together, pancreatic carcinogenesis could be considerably recapitulated with organoids, which would probably serve as a novel disease model.
We showed that Kras-dependent pancreatic carcinogenesis can be essentially, albeit not perfectly, reconstituted even in a completely ex vivo setting, providing an alternative model to decipher its pathogenesis by comparing with in vivo models, and valuable resources for translational studies.
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