Ribonucleic acid-binding protein CPSF6 promotes glycolysis and suppresses apoptosis in hepatocellular carcinoma cells by inhibiting the BTG2 expression

m6A-mediated regulation of CPSF6 by METTL3 promotes oxaliplatin resistance in colorectal cancer through enhanced glycolysis

Oxaliplatin resistance poses a significant challenge in colorectal cancer (CRC) treatment. Recent studies have implicated CPSF6 in cancer progression and drug resistance, although its role in chemotherapy resistance and regulatory mechanisms is unclear. This study investigates CPSF6's involvement in oxaliplatin resistance in CRC and its regulation via m6A methylation by METTL3. We assessed CPSF6 expression in oxaliplatin-resistant (OxR) CRC cell lines (HT29-OxR and HCT116-OxR) compared to sensitive counterparts using qRT-PCR and Western blotting. CPSF6 was significantly upregulated in OxR cells, and its knockdown reduced cell viability, colony formation, and glycolytic activity while increasing apoptosis. m6A modification of CPSF6 mRNA was elevated in OxR cells, correlating with increased METTL3 expression. METTL3 knockdown decreased CPSF6 levels and m6A enrichment, enhancing mRNA degradation, while its overexpression stabilized CPSF6 mRNA, promoting resistance. Xenograft experiments showed that CPSF6 knockdown suppressed tumor growth and glycolysis. Thus, CPSF6 is identified as a mediator of oxaliplatin resistance in CRC, regulated by the METTL3/m6A axis, suggesting potential therapeutic targets to overcome resistance.

HIV-1-induced translocation of CPSF6 to biomolecular condensates

Cleavage and polyadenylation specificity factor subunit 6 (CPSF6, also known as CFIm68) is a 68 kDa component of the mammalian cleavage factor I (CFIm) complex that modulates mRNA alternative polyadenylation (APA) and determines 3' untranslated region (UTR) length, an important gene expression control mechanism. CPSF6 directly interacts with the HIV-1 core during infection, suggesting involvement in HIV-1 replication. Here, we review the contributions of CPSF6 to every stage of the HIV-1 replication cycle. Recently, several groups described the ability of HIV-1 infection to induce CPSF6 translocation to nuclear speckles, which are biomolecular condensates. We discuss the implications for CPSF6 localization in condensates and the potential role of condensate-localized CPSF6 in the ability of HIV-1 to control the protein expression pattern of the cell.

Follicular fluid exosomes inhibit expression of BTG2 and promote glucose uptake in granulosa cells by delivering miR-21-5p

Glucose metabolism in granulosa cells (GCs) is essential for follicle development and oocyte maturation. Porcine follicular fluid exosomes promote the proliferation of porcine GCs and the synthesis of steroid hormones. However, their role in regulating glucose uptake in GCs is unclear. The objective of this study was to elucidate the effects of porcine follicular fluid exosomes on glucose uptake in porcine GCs and the intrinsic mechanisms involved. First, transcriptome sequencing revealed that glucose metabolism-related pathways were altered in GCs treated with follicular fluid exosomes. Next, in vitro culture experiments showed that glucose uptake was increased and the IRS1/AKT signaling pathway was activated in GCs after treatment with follicular fluid exosomes. Finally, miRNA sequencing of follicular fluid exosomes revealed that miR-21-5p was the most abundant miRNA. Subsequent investigations indicated that miR-21-5p promoted glucose uptake in GCs by targeting BTG2, which activated the IRS1/AKT signaling pathway. In conclusion, the findings of this study indicate that porcine follicular fluid exosomes promote glucose uptake in porcine GCs by delivering miR-21-5p, which inhibits the expression of BTG2, activating the IRS1/AKT signaling pathway.

Mitochondrial Pyruvate Carrier 1 as a Novel Prognostic Biomarker in Non-Small Cell Lung Cancer

BACKGROUND

Abnormal mitochondrial pyruvate carrier 1 (MPC1) expression plays a key role in tumor metabolic reprogramming and progression. Understanding its significance in non-small cell lung cancer (NSCLC) is crucial for identifying therapeutic targets.

METHODS

TIMER 2.0 was utilized to assess the expression of MPC1 in both normal and cancer tissues in pan-cancer. Overall survival (OS) differences between high and low MPC1 expression were analyzed in NSCLC using the Cancer Genome Atlas (TCGA) datasets. We also examined the expression of MPC1 in NSCLC cell lines using western blotting and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). In addition, the tissue samples and clinical information of 80 patients with NSCLC from our hospital were collected. Immunohistochemistry (IHC) was used to assess MPC1 expression, and OS was evaluated using Kaplan-Meier curves and the log-rank test. Univariate and multivariate Cox regression analyses were conducted to evaluate the prognostic values of the clinical characteristics and MPC1expression.

RESULTS

Analysis of public databases suggested that MPC1 was downregulated in NSCLC compared to that in normal lung tissue and predicted poor prognosis. In addition, the expression of MPC1 in NSCLC cell lines was lower than that in human bronchial epithelial (HBE) cells at both protein and mRNA levels. Further clinical analysis suggested that MPC1 expression was correlated with age, tumor T stage, and TNM stage. Kaplan-Meier analysis revealed that NSCLC patients with high MPC1 expression had a better prognosis, particularly in lung adenocarcinoma (LUAD), whereas no survival benefit was observed in lung squamous cell carcinoma (LUSC). Univariate and multivariate analyses suggested that MPC1 was an independent prognostic factor for patients with NSCLC.

CONCLUSIONS

MPC1 is poorly expressed in NSCLC, particularly in LUAD, which predicts a poor prognosis and may serve as an independent prognostic factor. Further studies on MPC1 may reveal new targets for the treatment of NSCLC.

Circular RNAs hsa_circ_0001438 and hsa_circ_0000417 are downregulated and upregulated, respectively, in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most predominant type of liver cancer and is frequently fatal. Alpha-fetoprotein, alpha-fetoprotein-L3, and protein induced by vitamin K absence or antagonist-II are used as biomarkers to diagnose HCC. However, these biomarkers are not highly specific, especially for early-stage HCC diagnosis; therefore, more specific biomarkers are needed. Recently, circular RNA (circRNA) biomarkers have been used to diagnose several intractable diseases. In this study, we sought to identify circRNA biomarkers for the specific diagnosis of HCC. To this end, we compared the expression levels of circRNAs in primary HCC and normal tissues using publicly available RNA-seq data. Our analysis revealed that the expression levels of eight circRNAs were altered in primary HCC tissues compared with normal tissues. To confirm our findings, we examined the expression levels of selected circRNAs in HCC cell lines and normal hepatocytes. The expression level of hsa_circ_0001438, a circRNA that was downregulated in primary HCC, was lower in poorly and well-differentiated HCC cell lines than in normal hepatocytes. By contrast, the expression level of hsa_circ_0000417, which was increased in primary HCC, was strongly upregulated in a well-differentiated HCC cell line compared with normal hepatocytes. Thus, hsa_circ_0001438 and hsa_circ_0000417 might be potential biomarkers for the specific diagnosis of HCC. The experimental strategy described here, using publicly available RNA-seq data, is a useful and cost-effective method of identifying circRNA biomarkers.

The roles of CPSF6 in proliferation, apoptosis and tumorigenicity of lung adenocarcinoma

Cleavage and polyadenylation specific factor 6 (CPSF6), a member of serine/arginine-rich protein family, is implicated in HIV-1-infection and replication. Overexpression of CPSF6 predicts poor prognostic outcomes of breast cancer. However, the expression and possible function of CPSF6 in lung adenocarcinoma (LUAD) still needs to be explored. Here, we found that CPSF6 is significantly higher expressed in tumor tissues than normal tissues in multiple cancer types. Besides, CPSF6 plays a significant risky role in LUAD that is associated with overall survival (HR=1.337, P=0.051) and disease-specific survival (HR=1.4739, P=0.042). CPSF6 mRNA was up-regulated in LUAD tissues by analyzing publicly available datasets from Gene Expression Omnibus (GEO). Further survival analysis on The Cancer Genome Atlas (TCGA) dataset suggested a close correlation between CPSF6 expression and overall survival, and disease-free survival of LUAD patients. Inhibition of CPSF6 expression by lentivirus-mediated RNA interference (RNAi) in two LUAD cell lines (A549 and NCH-H1299) caused a significant reduction in cell proliferation, colony formation and a notable induction in apoptotic rate. CPSF6 knockdown in xenograft tumors inhibited LUAD cell growth in vivo. Moreover, we identified differentially expressed genes with CPSF6 inhibition by Microarray analysis, and pathway analyses revealed that CPSF6 knockdown resulted in the dysregulation of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway. Collectively, our results are the first to demonstrate that CPSF6 functions as an oncoprotein by regulating cancer-related pathways in LUAD.

Construction of a prognostic risk model based on apoptosis-related genes to assess tumor immune microenvironment and predict prognosis in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a serious malignant disease with high incidence, high mortality and poor prognosis. This study aimed to establish a novel signature based on apoptosis-related genes (ARGs) to predict the prognosis of HCC.

METHODS

Expression data of HCC from TCGA database and the list of 160 ARGs from MSigDB were downloaded. The genes included in apoptosis-related signature were selected by univariate Cox regression analysis and lasso Cox regression analysis. Subsequently, a prognostic risk model for scoring patients was developed, and then separates patients into two groups. Kaplan-Meier and receiver operating characteristic analysis were performed to evaluate the prognostic value of the model in TCGA, GEO and ICGC databases. The characteristics of immune cell infiltration between two groups of HCC were investigated. Finally, a nomogram was plotted to visualize the prognosis prediction.

RESULTS

Nine genes (CDC25B, DAP3, ETF1, GSR, LGALS3, MGMT, PPP2R5B, SQSTM1 and VDAC2) were included in the prognostic risk model. Survival was lower in the high-risk group. Surprisingly, the high-risk group was significantly more in immune cell infiltration and with higher immunoscore and stromalscore than in the low-risk group. In addition, the risk score was an independent prognostic factor for HCC.

CONCLUSIONS

Prognostic signature comprising nine ARGs could be used as a potential prognostic factor for HCC. It also provides an important idea for further understanding the immunotherapy of HCC.