Background: Castration-resistant prostate cancer (PCa; CRPC) has a poor response to androgen deprivation therapy and is considered an incurable disease. MicroRNA (miR)-lethal 7c (let-7c) was implied to be a tumor suppressor in PCa, and treatment with exogenous let-7c targets both cancer cells and their associated mesenchymal stem cells (MSCs) to prevent CRPC progression and metastasis. Exosomes are nanometer-sized membrane-bound vesicles which have an absolute predominance in biocompatibility for drug delivery and gene therapy by mediating cell-to-cell communication. By utilizing the intrinsic tumor-targeting property of MSCs, this study aimed to investigate the feasibility of MSC-derived exosomes as an exogenous miR delivery system to target CRPC, using miR let-7c as an example. Methods: Bioinformatics analysis was performed to observe miR-let-7c expression in clinical samples by utilizing the GEO database. MSCderived exosomes were collected from a human bone marrow-derived MSC cell line after cell transfection with either a pre-miR negative control or pre-miR-let-7c, and further characterized through nanoparticle tracking analysis and Western blotting. miR-let-7c expression was determined using RT-qPCR, and the phenotypic effects of both naked and MSC-exosome-encapsulated let-7c on CRPC cells (PC3 and CWR22Rv1) were determined by WST-1 cell proliferation assay and wound healing migration assay. Results: miR-let-7c was downregulated in metastatic PCa and high grade group patients. miR-let-7c expression was confirmed to be downregulated in PCa cell lines, with massively decreased in most metastatic CRPC-like cells. Exogenous miR-let-7c can be successfully packaged into MSC exosomes. Treatment with either naked or MSC-exosome-encapsulated miR-let-7c resulted in significant reductions in cell proliferation and migration in CRPC-like PC3 and CWR22Rv1 cells. Conclusions: MSC-derived exosomes could serve as a therapeutic let-7c delivery system to target CRPC.

Breast care after childbirth so that the breasts are clean, and not Intervared.According to the Indonesian Demographic and Health Survey, the IDHS showedthat 20% of mothers had mastitis, breast abscess and sore nipples. The purpose ofthe study was to determine the knowledge of postpartum mothers about the impactof not doing breast care.The research method uses descriptive. The sample in this study were 25postpartum mothers. The sampling technique used was non-probability,accidental sampling. The data measurement tool uses a closed questionnaire.Data analysis used univariate analysis with percentage formula.The results of postpartum mothers' knowledge about breast care were in the goodcategory, namely 8 respondents (32.00%), and the category was sufficient for 12respondents (48.00%). And the category of less than 5 respondents (20.00%).The conclusion of the research is that the majority of postpartum mothers'knowledge about breast care for postpartum mothers is sufficient

Teaching Natural Sciences classes should be done creatively using natural resources as the learning media because the interaction between teachers and students without any media and learning sources will lead to students' lack of interest and low learning outcomes. Additionally, intensive communication between teachers and students needs to be taken into consideration to maximize the teaching-learning process. This study aimed at investigating the difference and the effect of teaching Natural Sciences using local natural resources through a lesson study-based scientific approach to student interest and learning outcomes at SMP Negeri 3 Sungai Raya. This study used quasi- experimental and nonequivalent control group designs. The samples were selected using a purposive sampling technique. The instruments were tests, questionnaires, and observation. The data were statistically analyzed using U-Mann Whitney. The results of the U-Mann Whitney test showed the value of students learning outcomes was 0,000 <0.05 and the value of students' interest was 0,000 <0.05. Besides, the value of the Effect Size of students learning outcomes reached 73.4% and the value of the Effect Size of students learning interest was 55.4%. In conclusion, students learning outcomes and learning interest increase significantly after taught using local natural resources through a lesson study-based scientific approach.