Translational Regulation by eIFs and RNA Modifications in Cancer

eIF6 Promotes Gastric Cancer Proliferation and Invasion by Regulating Cell Cycle

OBJECTIVE

To investigate the role and function of eIF6 in gastric cancer (GC).

METHODS

The expression level of eIF6 in GC tissues and normal tissues was detected in different high-throughput sequencing cohorts. Survival analysis, gene differential analysis, and enrichment analysis were performed in the TCGA cohort. Biological networks centered on eIF6 were constructed through two different databases. Immunohistochemistry (IHC) and Western blot were used to detect protein expression of eIF6, and qRT-PCR was used to detect eIF6 mRNA expression. The correlation between the expression of eIF6 in GC tissues and clinicopathological parameters of GC was analyzed. siRNA knockout of eIF6 was used to study the proliferation, migration, and invasion. The effects of eIF6 on cell cycle and Cyclin B1 were detected by flow cytometry and Western blot.

RESULTS

eIF6 was significantly overexpressed in GC tissues and predicted poor prognosis. In addition, 113 differentially expressed genes were detected in cancer-related biological pathways and functions by differential analysis. Biological networks revealed interactions of genes and proteins with eIF6. The expression intensity of eIF6 in cancer tissues was higher than that in adjacent tissues (P = 0.0001), confirming the up-regulation of eIF6 expression in GC tissues. The expression level of eIF6 was statistically significant with pTNM stage (P = 0.006). siRNA knockout of eIF6 significantly reduced the proliferation, colony formation, migration, and invasion ability of GC cells. Silencing of eIF6 also inhibited the cell cycle of GC cells in G2/M phase and decreased the expression level of CyclinB1.

CONCLUSION

Our study suggests that eIF6 is up-regulated in GC and may promote the proliferation, migration, and invasion of GC by regulating cell cycle.

Genetic evidence supporting potential causal roles of EIF4 family in breast cancer: a two-sample randomized Mendelian study

Translational control plays a crucial role in the regulation of apoptosis, with the EIF4 family serving as one of the mRNA translation factors that modulate the process of mRNA translation based on mRNA characteristics. To address this potential causal role of EIF4 family proteins and breast cancer, Mendelian randomization was employed. The study incorporated four sets of genetics instrumental variables, namely EIF4E, EIF4B, EIF4A, and EIF4EBP2. The outcome variables selected for analysis were the BCAC consortium, which included estrogen receptor positive (ER+) and estrogen receptor negative (ER-) samples. To assess the potential violations of the MR assumption, the primary MR analysis employed inverse variance weighted (IVW), and several sensitivity analyses were conducted. The findings of the two-sample MR analysis indicate that EIF4E has an adverse effect on breast cancer risk (p = 0.028). However, the evidence for the relationship between EIF4E and ER status of breast cancer suggests a weak association with ER+ breast cancer (p = 0.054), but not with ER- breast cancer (p > 0.05). The study findings indicate that EIF4A is not causally linked to the risk of ER+ breast cancer, but is significantly associated with an elevated risk of ER- breast cancer (p = 0.028). However, the evidence is inadequate to support the effects of EIF4B and EIF4EBP2 on breast cancer (p > 0.05). Our results suggest that EIF4 may be a potential factor in the occurrence and development of breast cancer, which may lead to a better understanding of its causes and prevention.

Analysis of the Anticancer Mechanism of OR3 Pigment from Streptomyces coelicolor JUACT03 Against the Human Hepatoma Cell Line Using a Proteomic Approach

This study assessed OR3 pigment, derived from Streptomyces coelicolor JUACT03, for its anticancer potential on HepG2 liver cancer cells and its safety on HEK293 normal cells. OR3 induced apoptosis and inhibited HepG2 cell proliferation, confirmed by caspase activation, Sub-G1 phase cell cycle arrest, and reduced colony formation. Proteomic analysis revealed altered expression of proteins associated with ribosomal function, mRNA processing, nuclear transport, proteasome activity, carbohydrate metabolism, chaperone function, histone regulation, and vesicle-mediated transport. Downregulation of proteins in MAPKAP kinase1, EIF2, mTOR, and EIF4 pathways contributed to apoptosis and cell cycle arrest. Changes in c-MYC, FUBP1 target proteins and upregulation of Prohibitin-1 (PHB1) were also noted. Western blot analysis supported alterations in eIF2, mTOR, and RAN pathways, including downregulation of RAB 5, c-MYC, p38, MAPK1, and MAPK3. OR3 exhibited significant anti-angiogenic activity in the in ovo CAM assay. In summary, OR3 demonstrated strong anticancer effects, inducing apoptosis, hindering proliferation, and displaying antiangiogenic properties. These findings highlight OR3's potential as an anticancer drug candidate, warranting further in vivo exploration.

Recent advances in the potential role of RNA N4-acetylcytidine in cancer progression

N4-acetylcytidine (ac4C) is a highly conserved chemical modification widely found in eukaryotic and prokaryotic RNA, such as tRNA, rRNA, and mRNA. This modification is significantly associated with various human diseases, especially cancer, and its formation depends on the catalytic activity of N-acetyltransferase 10 (NAT10), the only known protein that produces ac4C. This review discusses the detection techniques and regulatory mechanisms of ac4C and summarizes ac4C correlation with tumor occurrence, development, prognosis, and drug therapy. It also comments on a new biomarker for early tumor diagnosis and prognosis prediction and a new target for tumor therapy. Video Abstract.

PEGylated Dmoc phosphoramidites for sensitive oligodeoxynucleotide synthesis

Sensitive oligodeoxynucleotides (ODNs) can be synthesized using Dmoc phosphoramidites, but only short ODNs were demonstrated. Here, we report the synthesis of much longer ODNs, which was made possible by the use of PEGylated Dmoc (pDmoc) phosphoramidites. The longer ODNs synthesized include those containing the sensitive 4acC epigenetic modification recently discovered in nature.

Signal Pathways and microRNAs in Osteosarcoma Growth and the Dual Role of Mesenchymal Stem Cells in Oncogenesis

The major challenges in Osteosarcoma (OS) therapy are its heterogeneity and drug resistance. The development of new therapeutic approaches to overcome the major growth mechanisms of OS is urgently needed. The search for specific molecular targets and promising innovative approaches in OS therapy, including drug delivery methods, is an urgent problem. Modern regenerative medicine focuses on harnessing the potential of mesenchymal stem cells (MSCs) because they have low immunogenicity. MSCs are important cells that have received considerable attention in cancer research. Currently, new cell-based methods for using MSCs in medicine are being actively investigated and tested, especially as carriers for chemotherapeutics, nanoparticles, and photosensitizers. However, despite the inexhaustible regenerative potential and known anticancer properties of MSCs, they may trigger the development and progression of bone tumors. A better understanding of the complex cellular and molecular mechanisms of OS pathogenesis is essential to identify novel molecular effectors involved in oncogenesis. The current review focuses on signaling pathways and miRNAs involved in the development of OS and describes the role of MSCs in oncogenesis and their potential for antitumor cell-based therapy.