Additive Manufacturing in Orthopedics: A Review

Additive manufacturing is an advanced manufacturing manner that seems like the industrial revolution. It has the inborn benefit of producing complex formations, which are distinct from traditional machining technology. Its manufacturing strategy is flexible, including a wide range of materials, and its manufacturing cycle is short. Additive manufacturing techniques are progressively used in bone research and orthopedic operation as more innovative materials are developed. This Review lists the recent research results, analyzes the strengths and weaknesses of diverse three-dimensional printing strategies in orthopedics, and sums up the use of varying 3D printing strategies in surgical guides, surgical implants, surgical predictive models, and bone tissue engineering. Moreover, various postprocessing methods for additive manufacturing for orthopedics are described.

Reprogramming and targeting of cholesterol metabolism in tumor-associated macrophages

Cholesterol, as a major component of cell membranes, is closely related to the metabolic regulation of cells and organisms; tumor-associated macrophages play an important push role in tumor progression. We know that tumor-associated macrophages are polarized from macrophages, and the abnormalities of cholesterol metabolism that may be induced during their polarization are worth discussing. This manuscript focuses on metabolic abnormalities in tumor-associated macrophages, and first provides a basic summary of the regulatory mechanisms of abnormal macrophage polarization. Subsequently, it comprehensively describes the features of abnormal glucose, lipid and cholesterol metabolism in TAMs as well as the different regulatory pathways. Then, the paper also discusses the link between abnormal cholesterol metabolism in TAMs and tumors, chronic diseases and aging. Finally, the paper summarizes cancer therapeutic strategies targeting cholesterol metabolism that are already in clinical trials, as well as nanomaterials capable of targeting cholesterol metabolism that are in the research stage, in the hope of providing value for the design of targeting materials. Overall, elucidating metabolic abnormalities in tumor-associated macrophages, particularly cholesterol metabolism, could provide assistance in tumor therapy and the design of targeted drugs.

Potential prognosis and immunotherapy predictor TFAP2A in pan-cancer

BACKGROUND

TFAP2A is critical in regulating the expression of various genes, affecting various biological processes and driving tumorigenesis and tumor development. However, the significance of TFAP2A in carcinogenesis processes remains obscure.

METHODS

In our study, we explored multiple databases including TCGA, GTEx, HPA, cBioPortal, TCIA, and other well-established databases for further analysis to expound TFAP2A expression, genetic alternations, and their relationship with the prognosis and cellular signaling network alternations. GO term and KEGG pathway enrichment analysis as well as GSEA were conducted to examine the common functions of TFAP2A. RT-qPCR, Western Blot and Dual Luciferase Reporter assay were employed to perform experimental validation.

RESULTS

TFAP2A mRNA expression level was upregulated and its genetic alternations were frequently present in most cancer types. The enrichment analysis results prompted us to investigate the changes in the tumor immune microenvironment further. We discovered that the expression of TFAP2A was significantly associated with the expression of immune checkpoint genes, immune subtypes, ESTIMATE scores, tumor-infiltrating immune cells, and the possible role of TFAP2A in predicting immunotherapy efficacy. In addition, high TFAP2A expression significantly correlated with several ICP genes, and promoted the expression of PD-L1 on mRNA and protein levels through regulating its expression at the transcriptional level. TFAP2A protein level was upregulated in fresh colon tumor tissue samples compared to that in the adjacent normal tissues, which essentially positively correlated with the expression of PD-L1.

CONCLUSIONS

Our study suggests that targeting TFAP2A may provide a novel and effective strategy for cancer treatment.

Promoter Methylation Changes in DNA Damage-Response Genes in Ovarian Cancer and Their Correlation with Prognosis

Background: Ovarian cancer has a poor prognosis, and DNA damage-response (DDR) genes are associated with both its occurrence and prognosis. However, previous studies have mostly focused on genetic mutations, with no clear conclusions on epigenetic factors such as DNA methylation. Methods: In this study, we comprehensively investigated the relationship between promoter methylation of DDR genes and ovarian cancer prognosis. We performed combined multidata analysis of the promoter methylation, expression, homologous recombination defieiency (HRD) score, and drug sensitivity of 377 DDR genes in ovarian cancer by utilizing The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. We then validated abnormal promoter methylation and its relationship with overall survival in clinical samples. Results: Our analysis identified 52 methylation-driven DDR genes that exhibited abnormal expression due to abnormal promoter methylation. These genes are mostly related to BRCA1-related DNA damage repair and cell cycle regulatory pathways. Further studies revealed six of these genes, BRCA1, PTTG1, TTK, AURKA, CDC6, and E2F1, to be significantly associated with HRD scores. Among them, E2F1, PTTG1, and CDC6 are associated with drug sensitivity. Finally, we verified in 81 ovarian cancer samples that methylation of the promoter of these three genes was significantly associated with patient survival. Conclusions: Our study identified a large number of methylation-driven aberrantly expressed DDR genes in ovarian cancer, some of which affect disease prognosis. Levels of methylation of these gene promoters may serve as potential prognostic markers.

METTL1 Enhances RRP9 mRNA Stability Through m7G Modification to Drive Colorectal Tumorigenesis

METTL1, a well-established RNA methyltransferase for the N(7)-methylguanosine (m7G) methylation modification, is responsible for human tumorigenesis. Here, we aimed to examine the activity and molecular determinants of METTL1 in colorectal cancer (CRC) development. METTL1 and ribosomal RNA processing 9 (RRP9) mRNA analysis was performed by quantitative PCR. Protein expression was detected by immunoblotting and immunohistochemistry (IHC). Cell sphere formation, invasion, and proliferation were assessed by sphere formation, transwell, and MTT assays, respectively. Cell migration was tested by transwell and wound healing assays. Subcutaneous xenografts were produced to analyze the role in vivo. The influence of METTL1 in m7G methylation and stability of RRP9 mRNA was evaluated by methylated immunoprecipitation (MeRIP) assay and Actinomycin D (Act D) treatment, respectively. METTL1 was highly expressed in CRC tumors and cell lines. METTL1 depletion suppressed CRC cell proliferation, invasiveness, migratory ability, and sphere formation potential in vitro, while increased METTL1 expression had opposite effects. METTL1 positively correlated with RRP9 expression in CRC. Mechanistically, METTL1 promoted RRP9 mRNA stability by mediating its m7G methylation, and METTL1 regulated the PI3K/AKT signaling by RRP9. Increased RRP9 expression partially reversed the suppressive effects of METTL1 depletion on CRC cell phenotypes in vitro. METTL1 depletion impeded the growth of HCT-116 subcutaneous xenografts in vivo by RRP9. Our observations identified METTL1 as a crucial protumorigenic factor to drive growth, metastasis, and stemness of CRC cells through RRP9, offering new targets for combating CRC.

Epigenetic editing of BRCA1 promoter increases cisplatin and olaparib sensitivity of ovarian cancer cells

Drug resistance is the primary contributor to the high mortality rate of ovarian cancer (OC). The loss of BRCA1/2 function is linked to drug sensitivity in OC cells. The aim of this study is to enhance the drug sensitivity of OC cells by inducing BRCA1 dysfunction through promoter epigenetic editing. Epigenetic regulatory regions within the BRCA1 promoter, affecting gene expression, were initially discerned through analysis of clinical samples. Subsequently, we designed and rigorously validated epigenetic editing tools. Ultimately, we evaluated the cisplatin and olaparib sensitivity of the OC cells after editing. The BRCA1 promoter contains two CpG-rich regions, with methylation of the region covering the transcription start site (TSS) strongly correlating with transcription and influencing OC development, prognosis, and homologous recombination (HR) defects. Targeting this region in OC cells using our designed epigenetic editing tools led to substantial and persistent DNA methylation changes, accompanied by significant reductions in H3K27ac histone modifications. This resulted in a notable suppression of BRCA1 expression and a decrease in HR repair capacity. Consequently, edited OC cells exhibited heightened sensitivity to cisplatin and olaparib, leading to increased apoptosis rates. Epigenetic inactivation of the BRCA1 promoter can enhance cisplatin and olaparib sensitivity of OC cells through a reduction in HR repair capacity, indicating the potential utility of epigenetic editing technology in sensitization therapy for OC.