Cholangiocarcinoma, a prevalent hepatic malignancy, exhibits a progressively rising incidence. While Eukaryotic translation initiation factor 3 subunit B (EIF3B) has been implicated in the occurrence and development of various cancers, its specific roles in cholangiocarcinoma remain unexplored. Immunohistochemical (IHC) analysis was employed to detect EIF3B/PCNA expression in cholangiocarcinoma. Cells were manipulated using short hairpin RNA (shRNA)-mediated lentiviruses or overexpression plasmids. Statistical significance was assessed using the Student\'s t-test and one-way ANOVA, with P < 0.05 considered statistically significant. EIF3B exhibited robust expression in cholangiocarcinoma, demonstrating a significant correlation with the pathological grade of cholangiocarcinoma patients. Furthermore, modulation of EIF3B expression, either depletion or elevation, demonstrated the ability to inhibit or enhance cholangiocarcinoma cell survival and migration in vitro. Mechanistically, we identified Proliferating Cell Nuclear Antigen (PCNA) as a downstream gene of EIF3B, driving cholangiocarcinoma. EIF3B stabilized PCNA by inhibiting PCNA ubiquitination, a process mediated by E3 ligase SYVN1. Similar to EIF3B, PCNA levels were also abundant in cholangiocarcinoma, and knocking down PCNA impeded cholangiocarcinoma development. Intriguingly, silencing PCNA attenuated the promotion induced by EIF3B overexpression. Furthermore, the elevated P21 protein level in shEIF3B RBE cells was partially attenuated after UC2288 (P21 signaling pathway inhibitor) treatment. Our findings underscored the potential of EIF3B as a therapeutic target for cholangiocarcinoma. Unraveling its functions holds promise for the development of more specific and effective targeted therapy strategies.

N6-methyladenosine (m6A) modification orchestrates cancer formation and progression by affecting the tumor microenvironment (TME). For hepatocellular carcinoma (HCC), immune evasion and angiogenesis are characteristic features of its TME. The role of YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), as an m6A reader, in regulating HCC TME are not fully understood. Herein, it is discovered that trimethylated histone H3 lysine 4 and H3 lysine 27 acetylation modification in the promoter region of YTHDF2 enhanced its expression in HCC, and upregulated YTHDF2 in HCC predicted a worse prognosis. Animal experiments demonstrated that Ythdf2 depletion inhibited spontaneous HCC formation, while its overexpression promoted xenografted HCC progression. Mechanistically, YTHDF2 recognized the m6A modification in the 5\'-untranslational region of ETS variant transcription factor 5 (ETV5) mRNA and recruited eukaryotic translation initiation factor 3 subunit B to facilitate its translation. Elevated ETV5 expression induced the transcription of programmed death ligand-1 and vascular endothelial growth factor A, thereby promoting HCC immune evasion and angiogenesis. Targeting YTHDF2 via small interference RNA-containing aptamer/liposomes successfully both inhibited HCC immune evasion and angiogenesis. Together, this findings reveal the potential application of YTHDF2 in HCC prognosis and targeted treatment.

Malignant melanoma (MM) is a neoplasm that develops from human melanocytes. It was reported that eukaryotic translation initiation factor 3 subunit B (EIF3B) is associated with multiple types of cancers, but its role in MM has not been reported. In the present study, we found that EIF3B was abundantly expressed in MM and was strongly related to lymphatic metastasis and pathological stage of MM patients. In addition, EIF3B depletion could block the progression of MM in vitro and in vivo. In contrast, EIF3B overexpression increased cell proliferation and migration in melanoma cells. More importantly, we identified that EIF3B\'s driver role in MM was mediated by PTGS2. In detail, we found that EIF3B stabilized PTGS2 expression by inhibiting PTGS2 ubiquitination, which is mediated by the E3 ligase MDM2. Moreover, like EIF3B, silencing PTGS2 could suppress MM development, and more interestingly, it could reverse the situation caused by overexpression of EIF3B in vitro and in vivo. Furthermore, the proliferation and migration inhibited by silencing of EIF3B were also partially recovered by overexpression of PTGS2. Overall, our findings revealed the potential of EIF3B as a therapeutic target for MM. Identification of EIF3B\'s function in MM may pave the way for future development of more specific and more effective targeted therapy strategies against MM.

Adult muscle stem cells, also known as satellite cells (SCs), play pivotal roles in muscle regeneration, and long non-coding RNA (lncRNA) functions in SCs remain largely unknown. Here, we identify a lncRNA, Lockd, which is induced in activated SCs upon acute muscle injury. We demonstrate that Lockd promotes SC proliferation; deletion of Lockd leads to cell-cycle arrest, and in vivo repression of Lockd in mouse muscles hinders regeneration process. Mechanistically, we show that Lockd directly interacts with RNA helicase DHX36 and the 5\'end of Lockd possesses the strongest binding with DHX36. Furthermore, we demonstrate that Lockd stabilizes the interaction between DHX36 and EIF3B proteins; synergistically, this complex unwinds the RNA G-quadruplex (rG4) structure formed at Anp32e mRNA 5\' UTR and promotes the translation of ANP32E protein, which is required for myoblast proliferation. Altogether, our findings identify a regulatory Lockd/DHX36/Anp32e axis that promotes myoblast proliferation and acute-injury-induced muscle regeneration.

Ulceration and immune status are independent prognostic factors for survival in melanoma patients. Herein univariate Cox regression analysis revealed 53 ulcer-immunity-related DEGs. We performed consensus clustering to divide The Cancer Genome Atlas (TCGA) cohort (n = 467) into three subtypes with different prognosis and biological functions, followed by validation in three merged Gene Expression Omnibus (GEO) cohorts (n = 399). Multiomics approach was used to assess differences among the subtypes. Cluster 3 showed relatively lesser amplification and expression of immune checkpoint genes. Moreover, Cluster 3 lacked immune-related pathways and immune cell infiltration, and had higher proportion of non-responders to immunotherapy. We also constructed a prognostic model based on ulceration and immune related genes in melanoma. EIF3B was a hub gene in the intersection between genes specific to Cluster 3 and those pivotal for melanoma growth (DepMap, https://depmap.org/portal/download/). High EIF3B expression in TCGA and GEO datasets was related to worst prognosis. In vitro models revealed that EIF3B knockdown inhibited melanoma cell migration and invasion, and decreased TGF-β1 level in supernatant compared with si-NC cells. EIF3B expression was negatively correlated with immune-related signaling pathways, immune cell gene signatures, and immune checkpoint gene expression. Moreover, its low expression could predict partial response to anti-PD-1 immunotherapy. To summarize, we established a prognostic model for melanoma and identified the role of EIF3B in melanoma progression and immunotherapy resistance development.

Background: Pancreatic cancer (PC) is a malignant tumor with hidden incidence, high degree of malignancy, rapid disease progression, and poor prognosis. Eukaryotic translation initiation factor 3 subunit B (EIF3B) is necessary for tumor growth, which is an alternative therapeutic target for many cancers. However, little is known about the relationship between EIF3B and PC. Methods: The expression of EIF3B in PC was detected by immunohistochemistry. EIF3B knockdown cell models were constructed by lentivirus infection. The MTT assay, the wound-healing assay, the transwell assay, the flow cytometry, and the Human Apoptosis Antibody Array was used to detect the effects of EIF3B knockdown on cell proliferation, cell migration, cell apoptosis, and cell cycle in vitro. Also, the effects of EIF3B knockdown on the tumor growth of PC were determined in vivo. Results: This study showed that the expression level of EIF3B was significantly up-regulated in PC tumor tissues and associated with pathological grade. In vitro, EIF3B knockdown inhibited the PC cell proliferation and migration, and the apoptosis levels were obviously promoted by regulating apoptosis-related proteins including Bcl-2, HSP27, HSP60, Survivin, sTNF-R2, TNF-α, TNF-β, TRAILR-3, TRAILR-4, and XIAP. Furthermore, the tumor growth of PC was inhibited after the knockdown of EIF3B in vivo. Conclusion: EIF3B was up-regulated in PC and was a promoter in the development and progression of PC, which could be considered as a therapeutic target for the treatment of PC.

UNASSIGNED: This study aimed to analyze the relative expression of Eukaryotic Translation Initiation Factor 3 Subunit B (EIF3B) in pancreatic cancer and elucidate its contribution to this disease.
UNASSIGNED: Relative expression of EIF3B in pancreatic cancer was analyzed by immunohistochemistry. Cell viability was determined by the MTT assay and cell proliferation was measured by direct cell counting. Cell apoptosis was detected by Annexin V staining followed by flow cytometry analysis, and cell cycle was analyzed by PI staining. The differential expression gene analysis was performed by microarray. Tumor progression in response to EIF3B deficiency in vivo was investigated using the xenograft tumor model.
UNASSIGNED: We found aberrantly high expression of EIF3B in pancreatic cancer, which associated with unfavorable prognosis. Knockdown of EIF3B greatly compromised cell viability and proliferation in both SW1990 and PANC-1 cells. Furthermore, EIF3B deficiency induced cell cycle arrest and spontaneous apoptosis. In vivo tumor progression was significantly suppressed by EIF3B silencing in the xenograft mouse model. Mechanistically, we characterized down-regulation of CDH1 and IRS1 and up-regulation of DDIT3, PTEN and CDKN1B, in response to EIF3B knockdown, which might mediate the oncogenic effect of EIF3B in pancreatic cancer.
UNASSIGNED: Our data uncovered the oncogenic role of EIF3B in pancreatic cancer.

OBJECTIVE: To investigate the functions of eIF3b in chronic myelogenous leukemia (CML).
METHODS: The expression of eIF3b was inhibited by transfecting aspecifically designed shRNA into the CML cell lines of TK-6 and K562. The CCK8 assay was conducted to determine cell viability, and flow cytometry was used to examine the change in the cell cycle and cell apoptosis. RNAsequencing was applied to screen the candidate targets of eIF3b to identify the underlying mechanisms of eIF3b.An in vivo tumour xenograft mouse model was established by injecting shRNA transfected cells into the NCG mice. The tumour size and body weight of mice were monitored every other day. The mice were sacrificed 2 weeks after the tumour cell injection. The expression of eIF3b and target genes in the tumour tissues were determined by immunohistochemical staining and Western blotting.
RESULTS: The group with inhibited expression of eIF3b led to about 50% lower cell viability compared with that of the control group (P < 0.05). Flow cytometry suggested that the percentage of increase in apoptotic cells was eight times higher than those in control group for TK-6 and K562 cells (P < 0.05). However, the difference between the cell amounts in the S phase for the experiment and control groups was not significant. After RNAsequencing and further validation via qPCR, C3G was screened as the potential target of eIF3b involved in the cell proliferation and apoptosis of CML cell lines. Subsequent in vivo analysis proved that the inhibition of eIF3b suppressed tumour formation and decreased C3G expression, thereby indicating that C3G was the potential target of eIF3b.
CONCLUSIONS: eIF3b is correlated with the cell proliferation and cell apoptosis of CML. Moreover, eIF3b regulation most probably occurs via regulating the expression of C3G.

A newly identified lncRNA designated as RP11-284P20.2 has been identified to be up-regulated in hepatocellular carcinoma (HCC), but its role in HCC remain poorly understood. Quantitative PCR and immunocytochemical analysis were performed using the HCC tissues to identify the potential interaction partners of RP11-284P20.2. Moreover, RP11-284P20.2 was knocked down in HCC cell lines, HepG2 and SMMC7721, to investigate the influence of this lncRNA on cell growth properties. Additionally, RNA fluorescence in situ hybridization and immunofluorescence, RNA immunoprecipitation, and RNA pull-down assays were performed to determine the interaction of RP11-284P20.2 with c-met mRNA and eukaryotic translation initiation factor 3b (EIF3b). Silencing RP11-284P20.2 inhibited cell viability, migration, invasion, and colony formation, and increased apoptosis. Overexpression of c-met abolished these effects of RP11-284P20.2 in HCC cells. Histopathological examination showed that HCC tissues with high RP11-284P20.2 expression had higher c-met protein level than that in HCC tissues with low RP11-284P20.2 expression. However, there was no positive correlation between the expression levels of RP11-284P20.2 and c-met mRNA. RP11-284P20.2 knockdown led to a decease in c-met protein expression level, but did not affect the c-met mRNA expression level. These data suggest that RP11-284P20.2 regulates c-met protein expression level, which is independent of c-Met mRNA expression level. It was also confirmed that RP11-284P20.2 has high affinity toward both c-met mRNA and EIF3b protein, and hence RP11-284P20.2 probably recruits EIF3b protein to c-met mRNA and further facilitates its translation. RP11-284P20.2 promotes cell proliferation and invasion in hepatocellular carcinoma by recruiting EIF3b to induce c-met protein synthesis.

The study aimed to investigate the effect of eukaryotic translation initiation factor 3 subunit B (EIF3B) on cell proliferation, migration, and apoptosis as well as the underlying mechanism in acute myeloid leukemia (AML). EIF3B expression was detected in AML-193, HL-60, OCI-AML2, and KG-1 cell lines and human primary bone marrow mononuclear cells (BMMC). EIF3B knockdown was realized by transfecting EIF3B ShRNA plasmids, and EIF3B knockdown and WNT2 overexpression were established by transfecting EIF3B ShRNA plasmids and WNT2 overexpression plasmids into KG-1 cells. The effect of EIF3B knockdown, and EIF3B knockdown plus WNT2 overexpression on cell proliferation, apoptosis, migration, glycogen synthase kinase 3B (GSK3B) and catenin beta 1 (CTNNB1) was assessed. EIF3B mRNA and protein expression were higher in AML-193, OCL-AML2 and KG-1 cell lines, but unchanged in the HL-60 cell line compared with human primary BMMC. The expression of WNT2 was decreased by EIF3B downregulation, while it had no effect on EIF3B expression. As for cell activities, EIF3B knockdown inhibited the cell proliferation and migration but promoted apoptosis by inhibiting WNT2 expression. In addition, EIF3B knockdown downregulated the expression of CTNNB1 but upregulated the expression of GSK3B by blocking WNT2 expression in AML, implying an inhibitory effect of EIF3B downregulation on WNT signaling pathway. EIF3B is upregulated and its knockdown inhibits cell proliferation, and migration, while promoting apoptosis by downregulating the WNT signaling pathway in AML.