E2F5 promotes proliferation and invasion of gastric cancer through directly upregulating UBE2T transcription

UBE2T promotes stage I lung adenocarcinoma progression through PBX1 ubiquitination and PBX1/RORA regulation

BACKGROUND

Post-translational modification pathway of protein ubiquitination is intricately associated with tumorigenesis. We previously reported elevated ubiquitin-conjugating enzyme 2T (UBE2T) as an independent risk factor in stage I lung adenocarcinoma and promoting cellular proliferation. However, its underlying mechanisms needed further investigation.

METHODS

Immunohistochemistry was used to assess the expression of UBE2T and retinoic acid receptor-related orphan receptor α (RORA) in stage I LUAD. Cell proliferation, migration, and invasion of LUAD cell lines were measured by Cell Counting Kit-8 assay (CCK-8), Colony-forming assay and Transwell assay, respectively. Western blot analysis was performed to determine the expression of epithelial-mesenchymal transition (EMT) markers. A xenograft model was established to evaluate the proliferative capacity of UBE2T and its interaction with RORA in promoting LUAD. Mechanistic insights into the promotion of early-stage LUAD by UBE2T were obtained through luciferase reporter assay, chromatin immunoprecipitation and co-immunoprecipitation.

RESULTS

UBE2T and RORA expression was significantly up- and down-regulated in early-stage LUAD patients which's proved to be associated with unfavorable outcomes, strengthened cell proliferation, migration, EMT and invasion through its interaction with RORA both in vivo and in vitro. The growth NSCLC xenografts was reduced by down-expression of UBE2T but was suppressed by RORA knockout. Mechanistically, UBE2T mediated the ubiquitination of the intermediate transcription factor PBX1, which played a transcriptional role in downstream regulation of RORA.

CONCLUSION

The oncogenic role of UBE2T and the UBE2T-PBX1-RORA axis in driving malignant progression in Stage I LUAD had been established. UBE2T might be a novel and promising therapeutic target for LUAD treatment.

E2F transcription factor 5, a new regulator in adipogenesis to mediate the role of Krüppel-like factor 7 in chicken preadipocyte differentiation and proliferation

E2F transcription factor 5 (E2F5) gene is a transcription factor, plays an important role in the development of a variety of cells. E2F5 is expressed in human and mouse adipocytes, but its specific function in adipogenesis is unclear. Krüppel-like factor 7 (KLF7) facilitates proliferation and inhibits differentiation in chicken preadipocytes. Our previous KLF7 chromatin immunoprecipitation-sequencing analysis revealed a KLF7-binding peak in the 3' flanking region of the E2F5, indicating a regulatory role of KLF7 in this region. In the present study, we investigated E2F5 potential role, the overexpression and knockdown analyses revealed that E2F5 inhibited the differentiation and promoted the proliferation of chicken preadipocytes. Moreover, we identified enhancer activity in the 3' flanking region (nucleotides +22661/+22900) of E2F5 and found that KLF7 overexpression increased E2F5 expression and luciferase activity in this region. Deleting the putative KLF7-binding site eliminated the promoting effect of KLF7 overexpression on E2F5 expression. Further, E2F5 reversed the KLF7-induced decrease in preadipocyte differentiation and increase in preadipocyte proliferation. Taken together, our findings demonstrate that KLF7 inhibits differentiation and promotes proliferation in preadipocytes by enhancing E2F5 transcription.

E2F5 Targeted by Let-7d-5p Facilitates Cell Proliferation, Metastasis and Immune Escape in Gallbladder Cancer

BACKGROUND

Gallbladder cancer (GBC) remains a serious cause of cancer-related mortality across the globe. E2F5 has been identified to as a known oncogene in various cancers. However, the special functions of E2F5 have not been investigated in GBC.

AIMS

To explore the regulatory functions of E2F5 and its related molecular regulatory mechanism in GBC progression.

METHODS

The expression of genes were examined through qRT-PCR, western blot and IHC assay. The cell proliferation was assessed through CCK-8 and EDU assays. The cytotoxicity was tested through LDH assay. The percentage of CD8+ T cells and cell apoptosis were evaluated through flow cytometry. The binding ability was detected through luciferase reporter assay. The tumor growth was assessed through in vivo assays.

RESULTS

In this study, it was demonstrated that E2F5 expression was evaluated in GBC, and resulted into poor prognosis. Bioinformatics analysis revealed E2F5 as a target for let-7d-5p, which when overexpressed, suppressed the metastasis and proliferation of GBC through the downregulation of E2F5. It was discovered that E2F5 activates JAK2/STAT3 signaling which is suppressed by let-7d-5p, implicating this pathway as one of the effectors of the oncogenic effects of ESF5 in GBC. E2F5 had been confirmed to aggravate tumor growth in vivo.

CONCLUSION

E2F5 targeted by let-7d-5p facilitated cell proliferation, metastasis and immune escape in GBC through the JAK2/STAT3 pathway.

Knockdown of RNA-binding protein IMP3 suppresses oral squamous cell carcinoma proliferation by destabilizing E2F5 transcript

The expression level of RNA-binding proteins (RBPs) is dysregulated in oral squamous cell carcinoma (OSCC) and other types of cancer. Among the RBPs, IMP3 is involved in the progression of OSCC. However, the regulation of mRNA fate by IMP3 in OSCC remains less understood. We analyzed the expression level of IMP3 and E2F5 in OSCC tissues and cell lines by immunohistochemistry, qRT-PCR and Western blot. Subsequently, to further investigate the effect of IMP3 on E2F5 expression, we used siRNAs to silence IMP3 expression in OSCC cell lines SCC-25 and SCC-4. The binding site of E2F5 mRNA and IMP3 was confirmed by RNA immunoprecipitation (RIP). Finally, the function of IMP3 and E2F5 was investigated in viro and in xenograft mouse models. Here we report a positive correlation between IMP3 and E2F5 expression in OSCC, which are involved in cell proliferation and cell cycle. Mechanistically, E2F5 mRNA is bound by IMP3 protein, and silencing it leads to a shortened mRNA half-life and reduced protein expression. Also, knockdown of IMP3 inhibited allograft tumor progression in vivo. These studies reveal the molecular mechanism by which IMP3 regulates E2F5 mRNA stability and identify IMP3/E2F5 as a potential therapeutic target in OSCC.

ELOA promotes tumor growth and metastasis by activating RBP1 in gastric cancer

BACKGROUND

Elongin A (ELOA), our previous work revealed, serves as a novel tumor suppressor in colorectal cancer. However, the function and mechanism of ELOA in other cancer types, including gastric cancer (GC), remain to be elucidated.

METHODS

The expression of ELOA was measured by quantitative reverse transcription-polymerase chain reaction and western blot. The effects of ELOA on GC growth and metastasis were assessed through a series of in-vitro and in-vivo assays. Furthermore, the potential mechanism of ELOA was revealed by RNA sequencing, dual luciferase reporter assay, chromatin immunoprecipitation, and rescue experiments in GC.

RESULTS

We uncovered increased expression of ELOA in GC tissues compared with paired normal tissues via bioinformatic analyses and our sample detection. Enhanced ELOA expression in GC tissues was obviously correlated with poor tumor differentiation, lymph node metastasis, advanced tumor stage, and a poor prognosis. A series of functional experiments showed that ELOA promoted the proliferation and metastasis of GC. Mechanistically, we revealed that the decreased levels of miR-490-3p caused the upregulation of ELOA in GC. Both RNA-seq and ChIP assays revealed that ELOA transcriptionally activated retinol-binding protein 1 (RBP1) by binding to its promotor. Furthermore, specific knockdown of RBP1 reduced the tumor-promoting ability of ELOA in GC cells.

CONCLUSIONS

In summary, our findings demonstrate that ELOA exerts oncogenic properties by activating RBP1 expression, providing the basis for a promising therapeutic target in GC.

Hsa_circ_0092887 targeting miR-490-5p/UBE2T promotes paclitaxel resistance in non-small cell lung cancer

BACKGROUND

Chemoresistance is a major contributing factor to cancer treatment failure. Emerging research reveals that circular RNA (circRNA) dysregulation is implicated in chemoresistance. Our current study aimed to investigate the involvement of hsa_circ_0092887 in paclitaxel (PTX) resistance in non-small cell lung cancer (NSCLC).

METHODS

RT-qPCR as well as western blotting were used for the analysis of hsa_circ_0092887, miR-490-5p and UBE2T expression in PTX-resistant NSCLC tumor tissues and cells. CCK-8 assay was done to determine the IC50 value of PTX. CCK-8 assay, wound healing assay, analysis of apoptosis related proteins (Bax and Bcl-2), and xenograft mouse models were utilized to investigate the role of hsa_circ_0092887 in PTX-resistance in NSCLC. The binding sites of miR-490-5p to hsa_circ_0092887 or UBE2T were predicted by bioinformatics tools and were verified by RIP and dual-luciferase assays.

RESULTS

Expression of hsa_Circ_0092887 was upregulated in NSCLC tumor samples/cell lines, and its expression was also higher in PTX-resistant tumor samples/cell lines when compared with their respective controls. Silencing of hsa_circ_0092887 in PTX-treated NSCLC cells inhibited cell proliferation and migration, induced apoptosis, and suppressed tumor growth in xenograft mouse models in vivo. MiR-490-5p was a direct target of hsa_circ_0092887, and UBE2T was a functional downstream target of hsa_circ_0092887/miR-490-5p axis. Hsa_circ_0092887 depletion-induced anti-cancer effects in PTX-treated NSCLC cells were reversed by miR-490-5p inhibitor. Furthermore, inhibition of miR-490-5p strengthened UBE2T expression, thereby attenuating the anti-cancer effects caused by UBE2T knockdown.

CONCLUSION

Hsa_circ_0092887 depletion alleviated PTX-resistance in NSCLC cells via modulating the miR-490-5p/UBE2T axis, and the targeted management of hsa_circ_0092887-mediated signaling axis might contribute to PTX-resistance intervention in NSCLC.

Increased Expression of SRSF1 Predicts Poor Prognosis in Multiple Myeloma

Background

Multiple myeloma (MM) is a clonal plasma cell disorder which still lacks sufficient prognostic factors. The serine/arginine-rich splicing factor (SRSF) family serves as an important splicing regulator in organ development. Among all members, SRSF1 plays an important role in cell proliferation and renewal. However, the role of SRSF1 in MM is still unknown.

Methods

SRSF1 was selected from the primary bioinformatics analysis of SRSF family members, and then we integrated 11 independent datasets and analyzed the relationship between SRSF1 expression and MM clinical characteristics. Gene set enrichment analysis (GSEA) was conducted to explore the potential mechanism of SRSF1 in MM progression. ImmuCellAI was used to estimate the abundance of immune infiltrating cells between the SRSF1^high and SRSF1^low groups. The ESTIMATE algorithm was used to evaluate the tumor microenvironment in MM. The expression of immune-related genes was compared between the groups. Additionally, SRSF1 expression was validated in clinical samples. SRSF1 knockdown was conducted to explore the role of SRSF1 in MM development.

Results

SRSF1 expression showed an increasing trend with the progression of myeloma. Besides, SRSF1 expression increased as the age, ISS stage, 1q21 amplification level, and relapse times increased. MM patients with higher SRSF1 expression had worse clinical features and poorer outcomes. Univariate and multivariate analysis indicated that upregulated SRSF1 expression was an independent poor prognostic factor for MM. Enrichment pathway analysis confirmed that SRSF1 takes part in the myeloma progression via tumor-associated and immune-related pathways. Several checkpoints and immune-activating genes were significantly downregulated in the SRSF1^high groups. Furthermore, we detected that SRSF1 expression was significantly higher in MM patients than that in control donors. SRSF1 knockdown resulted in proliferation arrest in MM cell lines.

Conclusion

The expression value of SRSF1 is positively associated with myeloma progression, and high SRSF1 expression might be a poor prognostic biomarker in MM patients.

ANLN and UBE2T are prognostic biomarkers associated with immune regulation in breast cancer: a bioinformatics analysis

OBJECTIVES

To screen and verify differential genes affecting the prognosis of breast cancer.

METHODS

Breast cancer gene expression datasets were downloaded from the GEO database, and original data were analyzed in R. The TIMER database was used to analyze the relationship between ANLN and UBE2T and immune cell infiltration.

RESULTS

Ten hub-key genes were identified, and survival analysis showed that UBE2T and ANLN were upregulated in breast cancer and their upregulation was associated with a poor prognosis. ANLN and UBE2T upregulation was associated with the prevalence of Th1 and Th2 cells, shifting the Th1/Th2 balance to Th2 in Basal and Luminal-B breast cancers, which indicates a poor prognosis (P < 0.05).

CONCLUSION

ANLN and UBE2T are potential biomarkers for predicting the prognosis of breast cancer.

LncRNA CASC11 Promotes Hepatocellular Carcinoma Progression via Upregulation of UBE2T in a m6A-Dependent Manner

Hepatocellular carcinoma (HCC) is one of the most frequent malignancies and the third leading cause of cancer-related deaths worldwide. Besides, it has been revealed that long non-coding RNA (LncRNA) cancer susceptibility candidate 11 (CASC11) is involved in cancer progression. However, the functional role and underlying mechanism of CASC11 in HCC remains largely unknown. In this context, here, it was found that CASC11 was upregulated in HCC tissues and associated with tumor grades, metastasis, and prognosis of HCC patients. Functionally, CASC11 facilitated HCC cell proliferation, migration, and invasion in vitro, and enhanced tumor growth and metastasis in vivo. Mechanistically, CASC11 associated with and stabilized Ubiquitin-conjugating enzyme E2T (UBE2T) mRNA. To be specific, it decreased UBE2T N⁶-methyladenosine (m⁶A) level via recruiting ALKBH5. Moreover, CASC11 inhibited the association between UBE2T mRNA and m⁶A reader protein YTHDF2. Taken together, our findings demonstrate the epigenetic mechanism of CASC11 in the regulation of UBE2T expression and possibly provide a novel therapeutic target for HCC treatment.