Overexpression of miR-506-3p reversed doxorubicin resistance in drug-resistant osteosarcoma cells.

Background and objective: Osteosarcoma is a common primary malignant tumor of bone, and doxorubicin is one of the most widely used therapeutic drugs. While the problem of doxorubicin resistance limits the long-term treatment benefits in osteosarcoma patients. The role of miRNAs and their target genes in osteosarcoma have become increasingly prominent. Currently, there is no report on miR-506-3p reversing doxorubicin resistance by targeting STAT3 in osteosarcoma. The purpose of this study was to investigate the molecular mechanism that overexpression of miR-506-3p reverses doxorubicin resistance in drug-resistant osteosarcoma cells. Methods: Doxorubicin-resistant osteosarcoma cells (U-2OS/Dox) were constructed by intermittent stepwise increasing stoichiometry. The target genes of miR-506-3p were predicted by bioinformatics approach and the targeting relationship between miR-506-3p and STAT3 was detected using dual luciferase reporter assay. U-2OS/Dox cells were treated with miR-506-3p overexpression and STAT3 silencing respectively. Then Western blot and RT-qPCR were used to detect the protein and mRNA expression levels of JAK2/STAT3 signaling pathway, drug-resistant and apoptotic associated molecules. The migration and invasion were assessed by cell scratch assay and transwell assay. The cell proliferative viability and apoptosis were investigated by CCK8 assay and flow cytometry assay. Results: U-2OS/Dox cells were successfully constructed with a 14.4-fold resistance. MiR-506-3p is directly bound to the 3'-UTR of STAT3 mRNA. Compared with U-2OS cells, the mRNA expression of miR-506-3p was reduced in U-2OS/Dox cells. Overexpression of miR-506-3p decreased the mRNA expression levels of JAK2, STAT3, MDR1/ABCB1, MRP1/ABCC1, Survivin and Bcl-2, and decreased the protein expression levels of p-JAK2, STAT3, MDR1/ABCB1, MRP1/ABCC1, Survivin and Bcl-2, and conversely increased Bax expression. It also inhibited the proliferation, migration and invasion of U-2OS/Dox cells and promoted cells apoptosis. The results of STAT3 silencing experiments in the above indicators were consistent with that of miR-506-3p overexpression. Conclusion: Overexpression of miR-506-3p could inhibit the JAK2/STAT3 pathway and the malignant biological behaviors, then further reverse doxorubicin resistance in drug-resistant osteosarcoma cells. The study reported a new molecular mechanism for reversing the resistance of osteosarcoma to doxorubicin chemotherapy and provided theoretical support for solving the clinical problems of doxorubicin resistance in osteosarcoma.

Study on the effect of artificial joint replacement for osteosarcoma.

Osteosarcoma is one of the most prevalent primary malignant bone tumors that affects teenagers more than adults. In recent years, artificial femoral replacement has become more and more common. The use of artificial total femoral replacement surgery prevents the need for amputating the damaged limb, preserves the patient's ability to move and bear weight on the leg, lessens the severity of the psychological trauma, and significantly raises the patient's quality of life. To explore the treatment methods and therapeutic effects of artificial femoral replacement in the treatment of femoral osteosarcoma. The clinical data of 11 patients with femoral malignant tumors who underwent artificial femoral replacement from January 2019 to March 2022 were retrospectively analyzed. Among them, 7 males and 4 females, 11 to 40 years old, average 19.36 ± 9.44 years old. The disease duration is 2 to 7 months, with an average of 4.7 months. Before and 3 months after operation, the patients who had tumors were given a score on the visual analog scale, and their quality of life was also measured. At the most recent follow-up, both the Musculoskeletal Tumor Society score and the Harris hip score were analyzed. Eleven patients were followed up for 6 to 58 months, and an average of 21 months. Complications such as wound infection, joint dislocation, and nerve damage did not occur. In 1 patient, popliteal vein thrombus formation, and in 2 patients with osteosarcoma died from tumor progression. Visual analog scale score at 3 months after surgery and the quality-of-life scores were 3.68 ± 1.39 and 40.04 ± 4.31, respectively, which were significantly improved compared to before surgery (5.94 ± 1.19 and 22.42 ± 3.63, respectively, P < .05). At the last interview, Musculoskeletal Tumor Society score is scored from 18 to 29 points, average 22.5 ± 5.9 points, and Harris hip score is scored from 42 to 90 points, with an average score of 69.0 ± 14.7. Artificial total femoral replacement is an effective limb salvage operation in the treatment of osteosarcoma.

High miR-3609 expression is associated with better prognosis in TNBC based on mining using systematic integrated public sequencing data.

MicroRNAs (miRNAs/miRs) are small endogenous RNAs that regulate gene expression post-transcriptionally. Abnormal miR-3609 expression is associated with the occurrence of pancreatic cancer, glioma and other diseases, such as polycystic ovary syndrome. However, the prognostic potential of miR-3609 has been reported in breast cancer. Thus, the present study aimed to investigate the differential expression and prognostic value of miR-3609 in patients with breast cancer from the UALCAN, cBioportal and Kaplan-Meier Plotter databases, respectively. Furthermore, the co-expression genes of miR-3609 in breast cancer were investigated using data from the LinkedOmics database, and functional enrichment analysis was performed using the LinkInterpreter module in LinkedOmics. The co-expression gene network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins database, and the cytoHubba plug-in was used to identify the hub genes, which were visualized using Cytoscape software. The prognoses of the hub genes were performed using the Kaplan-Meier Plotter database. The Cell Counting Kit-8 and cell cycle assays were performed to confirm the functions of miR-3609 mimics transfection in MDA-MB-231 cells. Survival analysis using the Kaplan-Meier Plotter database demonstrated that high miR-3609 expression in triple-negative breast cancer (TNBC) was associated with a better prognosis. Furthermore, the experimental results indicated that high miR-3609 expression inhibited the proliferation of TNBC cells and induced cell cycle arrest of TNBC cells in the G0/G1 phase. Taken together, the results of the present study suggest that miR-3609 plays a vital role in mediating cell cycle arrest and inhibiting the proliferation of TNBC cells.

Identification of Five Immune-Related lncRNAs Predicting Survival and Tumor Microenvironment Characteristics in Breast Cancer.

A common cancer in females, breast cancer (BRCA) mortality has been recently reduced; however, the prognosis of BRCA patients remains poor. This study attempted to develop prognostic immune-related long noncoding RNAs (lncRNAs) for BRCA and identify the effects of these lncRNAs on the tumor microenvironment (TME). Gene expression data from The Cancer Genome Atlas (TCGA) database were collected in order to select differentially expressed lncRNAs. Immune-related lncRNAs were downloaded from the ImmLnc database, where 316 immune-related lncRNAs were identified, 12 of which were found to be significantly related to the prognosis of BRCA patients. Multivariate cox regression analysis was then applied to construct prognostic immune-related lncRNAs as the risk model, including C6orf99, LINC00987, SIAH2-AS1, LINC01010, and ELOVL2-AS1. High-risk and low-risk groups were distinguished according to the median of immune-related risk scores. Accordingly, the overall survival (OS) in the high-risk group was observed to be shorter than that in the low-risk group. qRT-PCR analysis demonstrated that lncRNA expression levels in BRCA cell lines were in basic agreement with predictions except for LINC00987. By validating numerous clinical samples, lncRNA C6orf99 was shown to be highly expressed in the advanced stage, while LINC01010 and SIAH2-AS1 decreased in the advanced T-stage and M-stage. Moreover, the expression of LINC0098 was found to be significantly decreased among the groups (>50 years old). Gene set enrichment analysis (GSEA) was applied to analyze the cancer hallmarks and immunological characteristics of the high-risk and low-risk groups. Importantly, the TIMER database demonstrated that this immune-related lncRNA risk model for breast cancer is related to the infiltration of immune cells. In conclusion, the results indicated that five immune-related lncRNAs could be used as a prognostic model and may even accelerate immunotherapy for BRCA patients.