[Correlation analysis of Poor Prognosis and Immunotherapy of lncRNAs Related with m 6A Modification in Cervical Cancer].

Objective: To study the correlation between N 6-methyladenosine (m 6A)-modification-associated long non-coding RNAs (lncRNAs) and poor prognosis and immunotherapy in cervical cancer based on data mining of The Cancer Genome Atlas (TCGA) cervical cancer dataset, so as to assess effectively the prognosis of cervical cancer patients and the feasibility of immunotherapy. Methods: We identified m 6A-modification-associated lncRNAs correlated to the prognosis of cervical cancer by conducting bioinformatics analysis of cervical cancer samples from the TCGA datasets and constructed a prognostic risk model of cervical cancer accordingly. Results: A total of 343 m 6A-modification-associated lncRNAs were identified from the samples of 304 cervical cancer patients. Univariate Cox regression analysis showed that 26 out of the 343 m 6A-modification-associated lncRNAs were significantly associated with the prognosis of cervical cancer patients. We identified 7 m 6A-modification-associated lncRNAs, including DLEU1, AC099850.4, DDN-AS1, EP300-AS1, AC131159.1, AL441992.2, and AL021707.6 through Lasso regression analysis and then developed a prognostic risk model based on them. According to the Kaplan-Meier survival analysis, cervical cancer patients in the low-risk group exhibited significantly improved overall survival (OS) in comparison with those in the high-risk group ( P<0.001). The area under the curve ( AUC) of receiver operating characteristic (ROC) curve analysis demonstrated the high sensitivity and credibility of the risk model. Multivariate Cox analysis showed that the risk score was an independent prognostic factor of cervical cancer patients. Tumor immune dysfunction and exclusion (TIDE) analysis predicted that the high-risk group would benefit more from immunotherapy. In addition, we found that immune checkpoint PD1 was associated with the expression of m6A-modification-related lncRNAs such as DDN-AS1, and the expression was higher in the high-risk group ( P<0.05). Conclusion: The prognostic risk model constructed on the basis of the aforementioned 7 m 6A-modification-associated lncRNAs can be used to effectively predict the prognosis of cervical cancer patients and assess the efficacy of immunotherapy targeting PD1.

[Increased TRIM5 is associated with a poor prognosis and immune infiltration in glioma patients].

Tripartite motif 5 (TRIM5) plays a significant function in autophagy and involves in immune and tumor processes. While the function of TRIM5 remains poorly understood in glioma. We purpose to evaluate the possible prognostic role of TRIM5 in glioma via bioinformatics analyses. The database clinical samples of glioma in this study included low grade glioma (LGG) and glioblastoma multiforme (GBM). TRIM5 expression in glioma tissues were explored in Oncomine, GEPIA and The Cancer Genome Atlas (TCGA) databases. Survival analysis and the multivariate Cox regression analysis of TRIM5 based on TCGA were used to evaluate the prognostic role of TRIM5. The protein networks of TRIM5 was detected by STRING database. KEGG enrichment analyses were performed to predict the potential molecular pathways of TRIM5 in glioma. In addition, immune infiltration analysis was conducted by CIBERSORT and TIMER databases. We found that TRIM5 was strongly increased in glioma samples compared with normal samples in Oncomine, GEPIA and TCGA databases. Higher TRIM5 was significantly contributed to worse overall survival (OS) in LGG+GBM patients and LGG patients, while was no correlated with OS of GBM patients. Interaction networks analysis identified that IRF3, IRF7, OAS1, OAS2, OAS3, OASL, GBP1, PML, BTBD1 and BTBD2 proteins were contacted with TRIM5. Moreover, KEGG revealed that apoptosis and cancer- and immune-related pathways were enriched with elevated TRIM5. Specifically, TRIM5 could influence the immune infiltration levels, such as activated NK cells, monocytes, activated mast cells and macrophages in glioma. In conclusion, our data indicated that TRIM5 was upregulated in glioma tissues and associated with poor prognosis and immune infiltration. TRIM5 may be acted as a biomarker in prognosis and immunotherapy guidance of glioma.

Cytochrome c oxidase IV isoform 1 (COX4-1) regulates the proliferation, migration and invasion of trophoblast cells via modulating mitochondrial function.

INTRODUCTION: Spontaneous miscarriage is a common complication of early pregnancy. Previous studies have shown that mitochondrial function plays an important role in establishment of a successful pregnancy. Cytochrome c oxidase subunit 4 isoform 1 (COX4I1), a component of electron transport chain complex Ⅳ, is required for coupling the rate of ATP production to energetic requirements. However, there is very limited research on its role in trophoblast biology and how its dysfunction may contribute to spontaneous miscarriage. METHODS: Placental villi (7-10 weeks gestational age) collected from either induced termination of pregnancy or after spontaneous miscarriage were examined for expression of COX4I1. COX4I1 was knocked down by siRNA transfection of primary isolates of EVT cells. Real-time cell analysis (RTCA) and 5-Ethynyl-2'-deoxyuridine (EdU) were used to detect changes in proliferation ability after COX4I1 knockdown of EVT cells. Migration and invasion indices were determined by RTCA. Mitochondrial morphology was observed via MitoTracker staining. Oxidative phosphorylation, ATP production, and glycolysis in COX4I1-deficient cells and controls were assessed by a cellular energy metabolism analyzer (Seahorse). RESULTS: In placental villous tissue, COX4I1 expression was significantly decreased in the spontaneous miscarriage group. Knockdown of COX4I1 inhibited EVT cell proliferation, increased the migration and invasion ability and mitochondrial fusion of EVT cells. Mitochondrial respiration and glycolysis were impaired in COX4I1-deficient EVT cells. Knockdown of MMP1 could rescue the increased migration and invasion induced by COX4I1 silencing. DISCUSSION: Low expression of COX4I1 leads to mitochondrial dysfunction in EVT, resulting in altered trophoblast function, and ultimately to pregnancy loss.

DDX39B protects against sorafenib-induced ferroptosis by facilitating the splicing and cytoplasmic export of GPX4 pre-mRNA in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the main histological subtype of primary liver cancer and remains one of the most common solid malignancies globally. Ferroptosis was recently defined as an iron-catalyzed form of regulated necrosis. Because cancer cells exhibit higher iron requirements than noncancer cells, treatment with ferroptosis-inducing compounds may be a feasible strategy for cancer therapy. However, cancer cells develop acquired resistance to evade ferroptosis, and the mechanisms responsible for ferroptosis resistance are not fully clarified. In the current study, we reported that DDX39B was downregulated during sorafenib-induced ferroptosis in a dose- and time-dependent manner. Exogenous introduction of DDX39B ensured the survival of HCC cells upon exposure to sorafenib, while the opposite phenomenon was observed in DDX39B-silenced HCC cells. Mechanistically, we demonstrated that DDX39B increased GPX4 levels by promoting the splicing and cytoplasmic translocation of GPX4 pre-mRNA, which was sufficient to detoxify sorafenib-triggered excess lipid ROS production, lipid peroxidation accumulation, ferrous iron levels, and mitochondrial damage. Inhibition of DDX39B ATPase activity by CCT018159 repressed the splicing and cytoplasmic export of GPX4 pre-mRNA and synergistically assisted sorafenib-induced ferroptotic cell death in HCC cells. Taken together, our data uncover a novel role for DDX39B in ferroptosis resistance by modulating the maturation of GPX4 mRNA via a posttranscriptional approach and suggest that DDX39B inhibition may be a promising therapeutic strategy to enhance the sensitivity and vulnerability of HCC cells to sorafenib.

DDX17 induces epithelial-mesenchymal transition and metastasis through the miR-149-3p/CYBRD1 pathway in colorectal cancer.

DEAD box helicase 17 (DDX17) has been reported to be involved in the initiation and development of several cancers. However, the functional role and mechanisms of DDX17 in colorectal cancer (CRC) malignant progression and metastasis remain unclear. Here, we reported that DDX17 expression was increased in CRC tissues compared with noncancerous mucosa tissues and further upregulated in CRC liver metastasis compared with patient-paired primary tumors. High levels of DDX17 were significantly correlated with aggressive phenotypes and worse clinical outcomes in CRC patients. Ectopic expression of DDX17 promoted cell migration and invasion in vitro and in vivo, while the opposite results were obtained in DDX17-deficient CRC cells. We identified miR-149-3p as a potential downstream miRNA of DDX17 through RNA sequencing analysis, and miR-149-3p displayed a suppressive effect on the metastatic potential of CRC cells. We demonstrated that CYBRD1 (a ferric reductase that contributes to dietary iron absorption) was a direct target of miR-149-3p and that miR-149-3p was required for DDX17-mediated regulation of CYBRD1 expression. Moreover, DDX17 contributed to the metastasis and epithelial to mesenchymal transition (EMT) of CRC cells via downregulation of miR-149-3p, which resulted in increased CYBRD1 expression. In conclusion, our findings not only highlight the significance of DDX17 in the aggressive development and prognosis of CRC patients, but also reveal a novel mechanism underlying DDX17-mediated CRC cell metastasis and EMT progression through manipulation of the miR-149-3p/CYBRD1 pathway.

DDX39B facilitates the malignant progression of hepatocellular carcinoma via activation of SREBP1-mediated de novo lipid synthesis.

PURPOSE: The detailed molecular mechanisms of aberrant lipid metabolism in HCC remain unclear. Herein, we focused on the potential role of DDX39B in aberrant lipogenesis and malignant development in HCC. METHODS: DDX39B expression in HCC and para-cancer tissues was measured by immunohistochemistry. CCK-8, colony formation and Transwell assays were utilized to detect HCC cell proliferation, migration and invasion in vitro. Oil red O and Nile red staining and triglyceride and cholesterol detection were used to measure lipogenesis. Coimmunoprecipitation was used to detect interactions between DDX39B and SREBP1. Immunofluorescence assays were performed to investigate the impact of DDX39B on SREBP1 nuclear translocation. A luciferase assay was used to explore the transcriptional activity of SREBP1. The subcutaneous and orthotopic xenograft models in nude mice were generated to verify the contribution of the DDX39B/SREBP1 axis to tumor growth, lung metastasis and lipid synthesis in vivo. RESULTS: DDX39B is upregulated in HCC tissues and predicts a worse prognosis. Upregulated DDX39B contributes to the proliferation, metastasis and lipogenesis of HCC cells. Mechanistically, DDX39B directly interacts with SREBP1, and silencing DDX39B impairs the stabilization of the SREBP1 protein through FBXW7-mediated ubiquitination and degradation of SREBP1. Furthermore, DDX39B deficiency decreases the nuclear translocation and activation of SREBP1 and transcription of SREBP1 downstream genes, resulting in reduced lipid accumulation. CONCLUSIONS: Our study reveals a novel mechanism by which DDX39B facilitates the malignant progression of HCC via activation of SREBP1-mediated de novo lipogenesis, implicating DDX39B as both a potential predictor of recurrence and prognosis and a promising therapeutic target.

DDX39B drives colorectal cancer progression by promoting the stability and nuclear translocation of PKM2.

Metastasis is a major cause of colorectal cancer (CRC) mortality, but its molecular mechanisms are still not fully understood. Here, we show that upregulated DDX39B correlates with liver metastases and aggressive phenotypes in CRC. DDX39B is an independent prognostic factor associated with poor clinical outcome in CRC patients. We demonstrate that Sp1 potently activates DDX39B transcription by directly binding to the GC box of the DDX39B promoter in CRC cells. DDX39B overexpression augments the proliferation, migration, and invasion of CRC cells, while the opposite results are obtained in DDX39B-deficient CRC cells. Mechanistically, DDX39B interacts directly with and stabilizes PKM2 by competitively suppressing STUB1-mediated PKM2 ubiquitination and degradation. Importantly, DDX39B recruits importin α5 to accelerate the nuclear translocation of PKM2 independent of ERK1/2-mediated phosphorylation of PKM2, leading to the transactivation of oncogenes and glycolysis-related genes. Consequently, DDX39B enhances glucose uptake and lactate production to activate Warburg effect in CRC. We identify that Arg319 of DDX39B is required for PKM2 binding as well as PKM2 nuclear accumulation and for DDX39B to promote CRC growth and metastasis. In addition, blocking PKM2 nuclear translocation or treatment with glycolytic inhibitor 2-deoxy-D-glucose efficiently abolishes DDX39B-triggered malignant development in CRC. Taken together, our findings uncover a key role for DDX39B in modulating glycolytic reprogramming and aggressive progression, and implicate DDX39B as a potential therapeutic target in CRC.

Loss of TRIM31 promotes breast cancer progression through regulating K48- and K63-linked ubiquitination of p53.

Breast cancer is the most common cancer in the world. Relapse and metastasis are important factors endangering the life of breast cancer patients, but the mechanism is still unclear. The stabilization of p53 is essential for preventing carcinogenesis, and ubiquitination is one of the main ways to regulate the stability of p53. Tripartite motif-containing 31 (TRIM31) is a new member of the TRIM family and functions as an E3 ubiquitin ligase. It acts as a cancer promoter or suppressor in the malignant processes of multiple cancers. However, the function of TRIM31 in breast cancer progression remains unknown. In this study, we showed that TRIM31 is downregulated in breast cancer tissues and negatively correlated with breast cancer progression. Both gain- and loss-of-function assays indicated that TRIM31 inhibits the proliferation, colony formation, migration, and invasion of breast cancer cells. Further investigation demonstrated that TRIM31 directly interacts with p53, and inducing the K63-linked ubiquitination of p53 via its RING domain, Meanwhile, TRIM31 suppresses the MDM2-mediated K48-linked ubiquitination of p53 through competitive inhibiting the interaction of MDM2 and p53, leading to the p53 stabilization and activation. Knockdown of p53 reversed the inhibitory effects of TRIM31 on the growth and metastasis of breast cancer cells. Moreover, we found that the RING and coiled-coil (C-C) domains of TRIM31 were essential for its tumor suppressor function. Taken together, our findings reveal a novel mechanism by which TRIM31 suppresses breast cancer development through the stabilization and activation of p53 and define a promising therapeutic strategy for restoring TRIM31 to treat breast cancer.