Biology Direct

TIMM8B promotes oxidative phosphorylation and glycolysis by inhibiting the mtROS/ASK1/JNK signaling pathway in ovarian cancer

Ovarian cancer is a complicated and heterogeneous disease. In this study, we investigated the functional significance of the gene TIMM8B, which is differentially expressed in ovarian cancer to better understand the molecular processes involved in the development of this disease. RNA sequencing was performed on ovarian cancer tissues and adjacent noncancerous tissues. The mRNA expression profiles obtained from the sequencing data (transcripts), TCGA-OV, and GSE14407 were subsequently used to identify common DEGs. GO, KEGG pathway, and PPI network analyses of these common DEGs were conducted. The expression of TIMM8B was examined in ovarian cancer tissues and cell lines. The effects of TIMM8B on cellular behaviors, such as proliferation, apoptosis, migration, invasion, and energy metabolism, were assessed by conducting cell-based assays. Additionally, the regulation of these processes by TIMM8B through the mtROS/ASK1/JNK signaling pathway was investigated. A total of 233 common DEGs were identified in ovarian cancer. The results of the GO analysis revealed enrichment in extracellular matrix organization, collagen-containing extracellular matrix, and transmembrane transporter activity, among others. The results of the KEGG pathway analysis revealed the involvement of DEGs in pathways such as oxidative phosphorylation and glycolysis/gluconeogenesis. TIMM8B was upregulated in ovarian cancer tissues and cell lines. TIMM8B enhanced oxidative phosphorylation, glycolysis, proliferation, migration, and invasion and inhibited apoptosis in ovarian cancer cells. TIMM8B was found to exert its effects through the suppression of mtROS/ASK1/JNK signaling. TIMM8B may regulate the mtROS/ASK1/JNK pathways, leading to an increase in oxidative phosphorylation and glycolysis. Targeting TIMM8B and its associated signaling pathway may help in the development of new treatment approaches for ovarian cancer.

STAU1-mediated CNBP mRNA degradation by LINC00665 alters stem cell characteristics in ovarian cancer

Abstract Background To investigate the role of lncRNA LINC00665 in modulating ovarian cancer stemness and its influence on treatment resistance and cancer development. Methods We isolated ovarian cancer stem cells (OCSCs) from the COC1 cell line using a combination of chemotherapeutic agents and growth factors, and verified their stemness through western blotting and immunofluorescence for stem cell markers. Employing bioinformatics, we identified lncRNAs associated with ovarian cancer, with a focus on LINC00665 and its interaction with the CNBP mRNA. In situ hybridization, immunohistochemistry, and qPCR were utilized to examine their expression and localization, alongside functional assays to determine the effects of LINC00665 on CNBP. Results LINC00665 employs its Alu elements to interact with the 3’-UTR of CNBP mRNA, targeting it for degradation. This molecular crosstalk enhances stemness by promoting the STAU1-mediated decay of CNBP mRNA, thereby modulating the Wnt and Notch signaling cascades that are pivotal for maintaining CSC characteristics and driving tumor progression. These mechanistic insights were corroborated by a series of in vitro assays and validated in vivo using tumor xenograft models. Furthermore, we established a positive correlation between elevated CNBP levels and increased disease-free survival in patients with ovarian cancer, underscoring the prognostic value of CNBP in this context. Conclusions lncRNA LINC00665 enhances stemness in ovarian cancer by mediating the degradation of CNBP mRNA, thereby identifying LINC00665 as a potential therapeutic target to counteract drug resistance and tumor recurrence associated with CSCs.

Deciphering the role of SAMHD1 in endometrial cancer progression

Endometrial cancer (EC) presents significant clinical challenges due to its heterogeneity and complex pathophysiology. SAMHD1, known for its role as a deoxynucleotide triphosphate triphosphohydrolase, has been implicated in the progression of various cancers, including EC. This study focuses on elucidating the role of SAMHD1 in EC through its impact on TRIM27-mediated PTEN ubiquitination. Utilizing a combination of bioinformatics and cellular biology techniques, we investigated the interactions among SAMHD1, TRIM27, and PTEN. Our findings reveal that SAMHD1 modulates PTEN ubiquitination via TRIM27, impacting key pathways involved in EC pathogenesis. These interactions suggest a critical mechanism by which SAMHD1 could influence tumor behavior and progression in EC. The results from this study underscore the potential of targeting the SAMHD1-TRIM27-PTEN axis as a therapeutic strategy in EC. By providing new insights into the molecular mechanisms underlying EC progression, our research supports the development of novel therapeutic approaches that could contribute to improve treatment strategies for patients with EC.

hsa_circ_0020093 suppresses ovarian cancer progression by modulating LRPPRC activity and miR-107/LATS2 signaling

A substantive body of evidence has demonstrated the significant roles of circular RNA (circRNA) in cancer. However, the contribution of dysregulated circRNAs to ovarian cancer (OC) remains elusive. We aim to elucidate the critical roles and mechanisms of hsa_circ_0020093, which was demonstrated to be downregulated in OC tissues in our previous study. In this study, we confirmed the decreased expression of hsa_circ_0020093 in OC tissues and cell lines and demonstrated the negative correlation between its expression and FIGO stage, abdominal implantation and CA125 level of OC patients. Through gain and loss of function studies, we confirmed the inhibitory role of hsa_circ_0020093 in ovarian tumor growth in vitro and in vivo. Mechanistically, based on the peri-nuclear accumulation of hsa_circ_0020093, we discovered the interaction between hsa_circ_0020093 and the mitochondrial protein LRPPRC by RNA pull-down, mass spectrometry, RNA Binding Protein Immunoprecipitation. As a result, qRT-PCR and transmission electron microscopy results showed that the mitochondria mRNA expression and mitochondria abundance were decreased upon hsa_circ_0020093-overexpression. Meanwhile, we also unearthed the hsa_circ_0020093/miR-107/LATS2 axis in OC according to RNA-sequencing, RIP and luciferase reporter assay data. Furthermore, LRPPRC and LATS2 are both reported as the upstream regulators of YAP, our study also studied the crosstalk between hsa_circ_0020093, LRPPRC and miR-107/LATS2, and unearthed the up-regulation of phosphorylated YAP in hsa_circ_0020093-overexpressing OC cells and xenograft tumors. Collectively, our study indicated the novel mechanism of hsa_circ_0020093 in suppressing OC progression through both hsa_circ_0020093/LRPPRC and hsa_circ_0020093/miR-107/LATS2 axes, providing a potential therapeutic target for OC patients.

Comprehensive pan-cancer analysis indicates UCHL5 as a novel cancer biomarker and promotes cervical cancer progression through the Wnt signaling pathway

UCHL5 was initially recognized as a multifunctional molecule. While recent research has highlighted its involvement in tumor malignant biological behaviors, its specific role in promoting tumor cell apoptosis has drawn particular attention. However, the precise relationship between UCHL5 and various tumor types, as well as its influence within the immune microenvironment, remains unclear. The transcriptomic data and clinicopathological parameters across 33 cancer types were obtained from TCGA. Clinical pathological parameters of tumor patients, including gender, age, survival time, and staging, are utilized to evaluate the association between UCHL5 and pan-cancer characteristics. The prognostic significance of UCHL5 was evaluated through Cox analysis and Kaplan-Meier (K-M) methods. Protein expression data for UCHL5 were obtained from The Human Protein Atlas database, and its subcellular localization was further investigated. Additionally, potential correlations between UCHL5 and factors such as tumor-infiltrating immune cells, immunomodulators, microsatellite instability (MSI), and tumor mutation burden (TMB) were explored. The relationship between UCHL5 and immunotherapy efficacy was also assessed in independent cohorts, including IMvigor210, GSE78220, GSE67501, and GSE168204. Finally, the impact of UCHL5 on the malignant biological behavior of cervical cancer cells was investigated through in vitro experiments, along with an exploration of the underlying mechanisms. We observed that UCHL5 expression levels were elevated in 11 types of cancer tissues compared to their corresponding normal tissues, while levels were lower in five tumor types. Additionally, UCHL5 expression displayed a significant correlation with tumor stage in BRCA, KIRC, LUAD, and TGCT. Cox and K-M analysis indicated that UCHL5 expression was significantly associated with prognosis in KIRC, KICH, CESC, ACC, and UVM. UCHL5 expression was negatively associated with stromal and immune scores in certain cancers. In terms of immune cell infiltration, UCHL5 expression in UCEC, SKCM, and COAD showed a negative correlation with regulatory T cells (Tregs). Furthermore, UCHL5 was widely associated with three types of immunomodulators. It also demonstrated a significant relationship with MSI and TMB in certain cancers and was connected to the immunotherapy efficacy. Finally, in vitro experiments confirmed that UCHL5 knockout enhances apoptosis in cervical cancer cells and disrupts Wnt/β-catenin signaling. Pan-cancer analysis indicates that UCHL5 is dysregulated in various tumor tissues and is closely associated with survival prognosis, the tumor immune microenvironment, and the efficacy of immunotherapy in certain cancer types. UCHL5 shows promise as a predictive biomarker, and its specific regulatory mechanisms across different cancers warrant further investigation.

Equol exerts anti-tumor effects on choriocarcinoma cells by promoting TRIM21-mediated ubiquitination of ANXA2

Choriocarcinoma is a malignant cancer that belongs to gestational trophoblastic neoplasia (GTN). Herein, serum metabolomic analysis was performed on 29 GTN patients and 30 healthy individuals to characterize the metabolic variations during GTN progression. Ultimately 24 differential metabolites (DMs) were identified, of which, Equol was down-regulated in GTN patients, whose VIP score is the 3rd highest among the 24 DMs. As an intestinal metabolite of daidzein, the anticancer potential of Equol has been demonstrated in multiple cancers, but not choriocarcinoma. Hence, human choriocarcinoma cell lines JEG-3 and Bewo were used and JEG-3-derived subcutaneous xenograft models were developed to assess the effect of Equol on choriocarcinoma. The results suggested that Equol treatment effectively suppressed choriocarcinoma cell proliferation, induced cell apoptosis, and reduced tumorigenesis. Label-free quantitative proteomics showed that 136 proteins were significantly affected by Equol and 20 proteins were enriched in Gene Ontology terms linked to protein degradation. Tripartite motif containing 21 (TRIM21), a E3 ubiquitin ligase, was up-regulated by Equol. Equol-induced effects on choriocarcinoma cells could be reversed by TRIM21 inhibition. Annexin A2 (ANXA2) interacted with TRIM21 and its ubiquitination was modulated by TRIM21. We found that TRIM21 was responsible for proteasome-mediated degradation of ANXA2 induced by Equol, and the inhibitory effects of Equol on the malignant behaviors of choriocarcinoma cells were realized by TRIM21-mediated down-regulation of ANXA2. Moreover, β-catenin activation was inhibited by Equol, which also depended on TRIM21-mediated down-regulation of ANXA2. Taken together, Equol may be a novel candidate for the treatment for choriocarcinoma.

N6-methyladenosine methyltransferase KIAA1429 promoted ovarian cancer aerobic glycolysis and progression through enhancing ENO1 expression

Abstract Background Despite improvements in prognosis due to advances in treatment, including surgery, genetic screening, and molecular targeted therapy, the outcomes of ovarian cancer (OC) remain unsatisfactory. Internal mRNA modifications are extremely common in eukaryotes; N6-methyladenosine (m6A) alteration has significant effects on mRNA stability and translation, and it is involved in the pathophysiology of numerous diseases related to cancer. Methods Bioinformatics analysis, quantitative real-time polymerase chain reaction and Western blotting were used to detect the expression of vir-like m6A methyltransferase associated (KIAA1429) in OC tissues and cell lines. Several different cell models and animal models were established to determine the role of KIAA1429 in glucose metabolism reprogramming and the underlying molecular mechanism of OC. The mechanism of oncology functional assays, co-immunoprecipitation and a luciferase reporter gene was employed to ascertain how KIAA1429 interacts with important molecular targets. Results We reported that KIAA1429 was overexpressed in OC and predicted a poor prognosis. Functionally, KIAA1429 promoted cell growth by inducing proliferation and inhibiting necrosis. Mechanistically, KIAA1429 promoted tumor progression and glycolysis via stabilizing ENO1 mRNA in a way dependent on m6A. Furthermore, we investigated that the SPI1 transcription factor is the main transcription factor that regulates KIAA1429 transcription in OC. Conclusion Our findings revealed that SPI1/KIAA1429/ENO1 signaling is a novel molecular axis and raises awareness of the vital functions of the changes in KIAA1429 and m6A changes in the metabolic reprogramming of OC. These results identified new potential biomarkers and treatment targets for OC.

H3K27ac-activated EGFR-AS1 promotes cell growth in cervical cancer through ACTN4-mediated WNT pathway

Abstract Background Recently, extensive studies unveiled that lncRNAs exert critical function in the development and progression of cervical cancer (CC). EGFR-AS1 is a novel lncRNA which has not been well-explored in CC. Aims Our study aimed to research the function and molecular mechanism of EGFR-AS1 in CC cells. qRT-PCR analysis was performed to detect gene expression. Colony formation, EdU, flow cytometry, TUNEL, western blot and transwell assays were performed to assess the effect of EGFR-AS1 on CC cell growth. The regulatory mechanism of EGFR-AS1 was dug out through mechanism experiments. Results EGFR-AS1 was notably overexpressed in CC cell lines. Loss-of-functional experiments revealed that EGFR-AS1 promoted CC cell proliferation, migration and invasion, and suppressed cell apoptosis. Mechanistically, up-regulation of EGFR-AS1 was attributed to the activation of H3K27 acetylation (H3K27ac). Further, EGFR-AS1 was revealed to function as miR-2355-5p sponge. Additionally, miR-2355-5p was down-regulated in CC cells and ACTN4 was identified as a target gene of miR-2355-5p. Ultimately, overexpressed ACTN4 could reserve the suppressive role of EGFR-AS1 silencing in CC cell growth. Last but not least, EGFR-AS1 facilitated CC cell growth via ACTN4-mediated WNT pathway. Conclusions H3K27ac-activated EGFR-AS1 sponged miR-2355-5p and promoted CC cell growth through ACTN4-mediated WNT pathway.

LINC00885 promotes cervical cancer progression through sponging miR-3150b-3p and upregulating BAZ2A

Abstract Background Cervical cancer (CC) is one of the most common malignancies affecting female worldwide. Long non-coding RNAs (lncRNAs) are increasingly indicated as crucial participants and promising therapeutic targets in human cancers. The main objective of this study was to explore the functions and mechanism of LINC00885 in CC. Methods RT-qPCR and western blot were used to detect RNA and protein levels. Functional and mechanism assays were respectively done for the analysis of cell behaviors and molecular interplays. Results Long intergenic non-coding RNA 885 (LINC00885) was discovered to be upregulated in CC tissues and cell lines through bioinformatics analysis and RT-qPCR. Overexpression of LINC00885 promoted proliferation and inhibited apoptosis, whereas its silence exerted opposite effects. The cytoplasmic localization of LINC00885 was ascertained and furthermore, LINC00885 competitively bound with miR-3150b-3p to upregulate BAZ2A expression in CC cells. Rescue assays confirmed that LINC00885 regulated CC proliferation and apoptosis through miR-3150b-3p/BAZ2A axis. Finally, we confirmed that LINC00885 aggravated tumor growth through animal experiments. Conclusions LINC00885 exerted oncogenic function in CC via regulating miR-3150b-3p/BAZ2A axis. These findings suggested LINC00885 might serve as a potential promising therapeutic target for CC patients.

ALKBH5 activates CEP55 transcription through m6A demethylation in FOXP2 mRNA and expedites cell cycle entry and EMT in ovarian cancer

Centrosomal protein of 55 kDa (CEP55) overexpression has been linked to tumor stage, aggressiveness of the tumor, poor prognosis, and metastasis. This study aims to elucidate the action of CEP55 in ovarian cancer (OC) and the regulation by the alpha-ketoglutarate-dependent dioxygenase alkB homolog 5 (ALKBH5)/Forkhead box protein P2 (FOXP2) axis. Differentially expressed genes in OC were identified using in silico identification, followed by prognostic value assessment. Lentiviral vectors were constructed to downregulate CEP55 in OC cells, and colony formation, EdU, TUNEL, flow cytometry, Transwell assays, and Phalloidin staining were conducted. Transcription factors regulating CEP55 were predicted and verified, and rescue experiments were performed. The effect of ALKBH5-mediated demethylation on FOXP2 mRNA stability and OC cell cycle and EMT were analyzed. High expression of CEP55 in OC was linked to unsatisfactory prognosis of patients. Knockdown of CEP55 repressed proliferation, invasiveness, and epithelial-mesenchymal transition (EMT) while inducing apoptosis and cell cycle arrest in OC cells. FOXP2 bound to the promoter of CEP55 to repress CEP55 transcription. FOXP2 regulated transcriptional repression of CEP55 to impede the malignant progression of OC and inhibit tumor metastasis. ALKBH5-mediated demethylation modification induced mRNA degradation of FOXP2. Knockdown of ALKBH5 induced cell cycle arrest and inhibited EMT in OC cells. ALKBH5 hinders FOXP2-mediated transcriptional repression of CEP55 to promote the malignant progression of OC via cell cycle and EMT.

Functional genomic imaging (FGI), a virtual tool for visualization of functional gene expression modules in heterogeneous tumor samples