miR-602 Mediates the RASSF1A/JNK Pathway, Thereby Promoting Postoperative Recurrence in Nude Mice with Liver Cancer

The study on circRNA profiling uncovers the regulatory function of the hsa_circ_0059665/miR-602 pathway in breast cancer

Abnormal expression of circRNAs has been observed in different types of carcinomas, and they play significant roles in the biology of these cancers. Nevertheless, the clinical relevance and functional mechanisms of the majority of circRNAs implicated in breast cancer progression remain unclear. The primary objective of our investigation is to uncover new circRNAs in breast cancer and elucidate the underlying mechanisms by which they exert their effects. The circRNA expression profile data for breast cancer and RNA-sequencing data were acquired from distinct public databases. Differentially expressed circRNAs and mRNA were identified through fold change filtering. The establishment of the competing endogenous RNAs (ceRNAs) network relied on the interplay between circular RNAs, miRNAs, and mRNAs. The hub genes were identified from the protein-protein interaction (PPI) regulatory network using the CytoHubba plugin in Cytoscape. Moreover, the expression levels and prognostic value of these hub genes in the PPI network were assessed using the GEPIA and Kaplan-Meier plotter databases. Fluorescence in situ hybridization (FISH) was used to identified the expression and intracellular localization of hsa_circ_0059665 by using the tissue microarray. Transwell analysis and CCK-8 analysis were performed to assess the invasion, migration, and proliferation abilities of breast cancer cells. Additionally, we investigated the interactions between hsa_circ_0059665 and miR-602 through various methods, including FISH, RNA-binding protein immunoprecipitation (RIP), and luciferase reporter assay. Rescue experiments were conducted to determine the potential regulatory role of hsa_circ_0059665 in breast cancer progression. A total of 252 differentially expressed circRNAs were identified. Among them, 246 circRNAs were up-regulated, while 6 circRNAs were down-regulated. Based on prediction and screening of circRNA-miRNA and miRNA-mRNA binding sites, we constructed a network consisting of circRNA-miRNA-mRNA interactions. In addition, we constructed a Protein-Protein Interaction (PPI) network and identified six hub genes. Moreover, the expression levels of these six hub genes in breast cancer tissues were found to be significantly lower. Furthermore, the survival analysis results revealed a significant correlation between low expression levels of KIT, FGF2, NTRK2, CAV1, LEP and poorer prognosis in breast cancer patients. The FISH experiment results indicated that hsa_circ_0059665 exhibits significant downregulation in breast cancer, and its decreased expression is linked to poor prognosis in breast cancer patients. Functional in vitro experiments revealed that overexpression of hsa_circ_0059665 can inhibit proliferation, migration and invasion abilities of breast cancer cells. Further molecular mechanism studies showed that hsa_circ_0059665 exerts its anticancer gene role by acting as a molecular sponge for miR-602. In our study, we constructed and analyzed a circRNA-related ceRNA regulatory network and found that hsa_circ_0059665 can act as a sponge for miR-602 and inhibit the proliferation, invasion and migration of breast cancer cells.

Upregulation of lncRNA HITT promotes cell apoptosis by suppressing the maturation of miR-602 in gastric cancer

It has been reported that HITT can inhibit colon cancer. However, the role of HITT in gastric cancer (GC) is unknown. Our preliminary sequencing data revealed the altered expression of HITT in GC and its close correlation with miR-602, suggesting the involvement of HITT and its potential interaction with miR-602 in GC. This study explored the role of HITT and its crosstalk with miR-602 in GC. In this study, the expression of HITT, premature and mature miR-602 in paired GC and normal tissues (62 patients) was detected by RT-qPCR. RNA pull-down assay was performed to evaluate the direct interaction between HITT and mature miR-602. The subcellular location of HITT was assessed by nuclear fractionation assay. The role of HITT in regulating miR-602 maturation was explored by overexpression assay. Cell apoptosis was analyzed by flow cytometry. Our data illustrated that HITT was highly upregulated and mature miR-602 was downregulated in GC. No alteration in premature miR-602 in GC was observed. HITT was located in both nucleus and cytoplasm, and it can directly interact with miR-602. In addition, overexpression of HITT in GC cells increased the expression levels of mature miR-602 but not premature miR-602. Overexpression of HITT further increased GC cell apoptosis and suppressed the role of miR-602 in inhibiting GC cell apoptosis. In conclusion, HITT may promote GC cell apoptosis by suppressing the maturation of miR-602.

miR-602 Activates NRF2 Antioxidant Pathways to Protect HBMECs from OGD/R-Induced Oxidative Stress via Targeting KEAP1 and HRD1

Blood brain barrier (BBB) dysfunction is a critical complication of diabetes mellitus type 2 (T2DM), and the oxidative stress-induced apoptosis of human brain microvascular endothelial cells (HBMECs) is a main cause of BBB dysfunction. In this study, oxygen and glucose deprivation/reoxygenation (OGD/R) models were established with HBMECs to analyze the effects of miR-602 on the apoptosis of HMBECs. Western Blot, qRT-PCR, CCK-8, flow cytometry assay, ROS detection assay, and dual-luciferase reporter gene assay were used to measure the expression levels of corresponding factors and changes in intracellular environment. The results showed that miR-602 was overexpressed in HBMECs after OGD/R treatment, and miR-602 could reduce ROS level of OGD/R-induced HBMECs and promote cells survival via increasing the expression level of NRF2 and the transcription activity of NRF2/ARE. Besides, it was found that KEAP1 and HRD1 were downstream factors of miR-602, and the increase of both KEAP1 and HRD1 could reverse the effects of miR-602 on the OGD/R-induced HMBECs. Therefore, miR-602 may be a potential target for research and treatment of the oxidative stress injury induced by apoptosis in HMBECs.

Regulation of RASSF by non-coding RNAs in different cancers

Ras-association domain family (RASSF) proteins are tumor suppressors and have gained phenomenal limelight because of their mechanistic role in the prevention/inhibition of carcinogenesis and metastasis. Decades of research have demystified wide ranging activities of RASSF molecules in multiple stages of cancers. Although major fraction of RASSF molecules has tumor suppressive roles, yet there is parallel existence of proof-of-concept about moonlighting activities of RASSF proteins as oncogenes. RASSF proteins tactfully rewire signaling cascades for prevention of cancer and metastasis but circumstantial evidence also illuminates oncogenic role of different RASSF proteins in different cancers. In this review we have attempted to provide readers an overview of the complex interplay between non-coding RNAs and RASSF proteins and how these versatile regulators shape the landscape of carcinogenesis and metastasis.

Autophagy and Hepatic Tumor Microenvironment Associated Dormancy

The goal of successful cancer treatment is targeting the eradication of cancer cells. Although surgical removal of the primary tumors and several rounds of chemo- and radiotherapy reduce the disease burden, in some cases, asymptomatic dormant cancer cells may still exist in the body. Dormant cells arise from the disseminated tumor cells (DTCs) from the primary lesion. DTCs escape from immune system and cancer therapy and reside at the secondary organ without showing no sign of proliferation. However, under some conditions. dormant cells can be re-activated and enter a proliferative state even after decades. As a stress response mechanism, autophagy may help the adaptation of DTCs at this futile foreign microenvironment and may control the survival and re-activation of dormant cells. Studies indicate that hepatic microenvironment serves a favorable condition for cancer cell dormancy. Although, no direct study was pointing out the role of autophagy in liver-assisted dormancy, involvement of autophagy in both liver microenvironment, health, and disease conditions has been indicated. Therefore, in this review article, we will summarize cancer dormancy and discuss the role and importance of autophagy and hepatic microenvironment in this context.

GRP75-mediated upregulation of HMGA1 stimulates stage I lung adenocarcinoma progression by activating JNK/c-JUN signaling

Background

Recurrence is a major challenge in early‐stage lung adenocarcinoma (LUAD) treatment. Here, we investigated the role and mechanism of high‐mobility group AT‐hook 1 (HMGA1) and glucose‐regulated protein 75‐kDa (GRP75) in stage I LUAD and evaluated their potential as biomarkers for predicting the recurrence and prognosis of stage I LUAD.

Methods

The TCGA dataset was used to investigate the clinical significance of HMGA1 and GRP75 in early‐stage LUAD. The biological functions of HMGA1 and GRP75 in LUAD were investigated both in vitro and in vivo through overexpression and knockdown experiments. The interaction and regulation between HMGA1 and GRP75 were evaluated with coimmunoprecipitation and ubiquitination assays. The downstream signaling pathway of the GRP75/HMGA1 axis was investigated by mRNA‐sequencing analysis.

Results

Both HMGA1 expression levels and GRP75 expression levels were associated with recurrence in stage I LUAD patients. In particular, HMGA1 had potential as an independent prognostic factor in stage I LUAD patients. Overexpression of GRP75 or HMGA1 significantly stimulated LUAD cell growth and metastasis, while silencing GRP75 or HMGA1 inhibited LUAD cell growth and metastasis in vitro and in vivo. Importantly, GRP75 inhibited ubiquitination‐mediated HMGA1 degradation by directly binding to HMGA1, thereby causes HMGA1 upregulation in LUAD. In addition, the GRP75/HMGA1 axis played its role by activating JNK/c‐JUN signaling in LUAD.

Conclusions

The activation of GRP75/HMGA1/JNK/c‐JUN signaling is an important mechanism that promotes the progression of stage I LUAD, and a high level of HMGA1 is a novel biomarker for predicting recurrence and a poor prognosis in stage I LUAD patients.

Interaction between non-coding RNAs and JNK in human disorders

Jun N-terminal Kinase (JNK) signaling pathway is a conserved cascade among species with particular roles in diverse processes during embryogenesis and normal life. These kinases regulate functions of neurons and the immune system by affecting the expression of genes, modulating the arrangement of cytoskeletal proteins, and regulating apoptosis/survival pathways. They are also involved in carcinogenesis. Several miRNAs and lncRNAs have a functional relationship with JNKs. This interaction contributes to the pathogenesis of traumatic brain injury, ulcerative colitis, hepatic ischemia/ reperfusion injury, acute myocardial infarction, and a number of other disorders. Lung cancer, hepatocellular carcinoma, gall bladder cancer, melanoma, and colon cancer are among malignant conditions in which JNK-related miRNAs/ lncRNAs contribute. The current review aims at depicting the functional interaction between JNKs and lncRNAs/ miRNAs and describing the role of these regulatory transcripts in the pathobiology of human disorders.

Integrative Analysis of Multi-Omics Data Based on Blockwise Sparse Principal Components

The recent development of high-throughput technology has allowed us to accumulate vast amounts of multi-omics data. Because even single omics data have a large number of variables, integrated analysis of multi-omics data suffers from problems such as computational instability and variable redundancy. Most multi-omics data analyses apply single supervised analysis, repeatedly, for dimensional reduction and variable selection. However, these approaches cannot avoid the problems of redundancy and collinearity of variables. In this study, we propose a novel approach using blockwise component analysis. This would solve the limitations of current methods by applying variable clustering and sparse principal component (sPC) analysis. Our approach consists of two stages. The first stage identifies homogeneous variable blocks, and then extracts sPCs, for each omics dataset. The second stage merges sPCs from each omics dataset, and then constructs a prediction model. We also propose a graphical method showing the results of sparse PCA and model fitting, simultaneously. We applied the proposed methodology to glioblastoma multiforme data from The Cancer Genome Atlas. The comparison with other existing approaches showed that our proposed methodology is more easily interpretable than other approaches, and has comparable predictive power, with a much smaller number of variables.