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1.
Oncogene ; 43(22): 1714-1725, 2024 May.
Article in English | MEDLINE | ID: mdl-38605214

ABSTRACT

Colorectal cancer (CRC) has a high degree of heterogeneity and identifying the genetic information of individual tumor cells could help enhance our understanding of tumor biology and uncover potential therapeutic targets for CRC. In this study, we identified LPCAT2+ tumor cell populations with less malignancy than LPCAT2- tumor cells in human and mouse CRC tissues using scRNA-seq. Combining in vitro and in vivo experiments, we found that LPCAT2 could inhibit the proliferation of CRC cells by inducing ferroptosis. Mechanistically, LPCAT2 arrested PRMT1 in cytoplasm of CRC cells via regulating acetylation of PRMT1 at the K145 site. In turn, PRMT1 enhanced SLC7A11 promoter activity. Thus, LPCAT2 attenuated the positive regulatory effect of PRMT1 on SLC7A11 promoter. Notably, SLC7A11 acts as a ferroptosis regulator. Furthermore, in LPCAT2 knockout mice (LPCAT2-/-) colon cancer model, we found that LPCAT2-/- mice exhibited more severe lesions, while PRMT1 or SLC7A11 inhibitors delayed the progression. Altogether, we elucidated that LPCAT2 suppresses SLC7A11 expression by inhibiting PRMT1 nuclear translocation, thereby inducing ferroptosis in CRC cells. Moreover, inhibitors of the PRMT1/SLC7A11 axis could delay tumor progression in CRC with low LPCAT2 expression, making it a potentially effective treatment for CRC.


Subject(s)
Amino Acid Transport System y+ , Colorectal Neoplasms , Disease Progression , Protein-Arginine N-Methyltransferases , Animals , Humans , Mice , Amino Acid Transport System y+/genetics , Amino Acid Transport System y+/metabolism , Cell Line, Tumor , Cell Proliferation , Colorectal Neoplasms/pathology , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/drug therapy , Ferroptosis/genetics , Ferroptosis/drug effects , Gene Expression Regulation, Neoplastic , Mice, Knockout , Protein-Arginine N-Methyltransferases/metabolism , Protein-Arginine N-Methyltransferases/genetics , Protein-Arginine N-Methyltransferases/antagonists & inhibitors , Repressor Proteins/genetics , Repressor Proteins/metabolism
3.
Clin Transl Med ; 14(2): e1558, 2024 02.
Article in English | MEDLINE | ID: mdl-38299307

ABSTRACT

There have been contradictory reports on the biological role of transforming growth factor-ßs (TGFßs) in breast cancer (BC), especially with regard to their ability to promote epithelial-mesenchymal transition (EMT). Here, we show that TGFß2 is preferentially expressed in mesenchymal-like BCs and maintains the EMT phenotype, correlating with cancer stem cell-like characteristics, growth, metastasis and chemo-resistance and predicting worse clinical outcomes. However, this is only true in ERα- BC. In ERα+ luminal-type BC, estrogen receptor interacts with p-Smads to block TGFß signalling. Furthermore, we also identify a microRNAs (miRNAs) signature (miRNAsTGFß2 ) that is weakened in TGFß2-overexpressing BC cells. We discover that TGFß2-Snail1 recruits enhancer of zeste homolog-2 to convert miRNAsTGFß2 promoters from an active to repressive chromatin configuration and then repress miRNAsTGFß2 transcription, forming a negative feedback loop. On the other hand, miRNAsTGFß2 overexpression reverses the mesenchymal-like traits in agreement with the inhibition of TGFß2-Snail1 signalling in BC cells. These findings clarify the roles of TGFß2 in BC and suggest novel therapeutic strategies based on the TGFß2-Snail1-miRNAsTGFß2 loop for a subset type of human BCs.


Subject(s)
Breast Neoplasms , MicroRNAs , Humans , Female , Breast Neoplasms/genetics , MicroRNAs/genetics , Estrogen Receptor alpha/genetics , Transforming Growth Factor beta/genetics , Signal Transduction/genetics
4.
Cell Death Dis ; 14(6): 348, 2023 06 03.
Article in English | MEDLINE | ID: mdl-37270643

ABSTRACT

The cytidine deaminase, Apolipoprotein B mRNA editing enzyme catalytic subunit 3B (APOBEC3B, herein termed A3B), is a critical mutation driver that induces genomic instability in cancer by catalyzing cytosine-to-thymine (C-to-T) conversion and promoting replication stress (RS). However, the detailed function of A3B in RS is not fully determined and it is not known whether the mechanism of A3B action can be exploited for cancer therapy. Here, we conducted an immunoprecipitation-mass spectrometry (IP-MS) study and identified A3B to be a novel binding component of R-loops, which are RNA:DNA hybrid structures. Mechanistically, overexpression of A3B exacerbated RS by promoting R-loop formation and altering the distribution of R-loops in the genome. This was rescued by the R-loop gatekeeper, Ribonuclease H1 (RNASEH1, herein termed RNH1). In addition, a high level of A3B conferred sensitivity to ATR/Chk1 inhibitors (ATRi/Chk1i) in melanoma cells, which was dependent on R-loop status. Together, our results provide novel insights into the mechanistic link between A3B and R-loops in the promotion of RS in cancer. This will inform the development of markers to predict the response of patients to ATRi/Chk1i.


Subject(s)
Neoplasms , R-Loop Structures , Humans , Mutation , Neoplasms/genetics , Cytidine Deaminase/genetics , Cytidine Deaminase/metabolism , Minor Histocompatibility Antigens/genetics , Ataxia Telangiectasia Mutated Proteins/genetics , Ataxia Telangiectasia Mutated Proteins/metabolism
5.
Biochim Biophys Acta Mol Basis Dis ; 1869(5): 166671, 2023 06.
Article in English | MEDLINE | ID: mdl-36858323

ABSTRACT

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) induced coronavirus disease 2019 (COVID-19) has recently caused a pandemic. Patients with COVID-19 presented with a wide spectrum of symptoms for the disease, from entirely asymptomatic disease to full-blown pneumonia and multiorgan failures. More evidence emerged, showing the production of interferons (IFNs) in the severe cases were significantly lower than their milder counterparts, suggesting linkage of COVID-19 to impaired innate immunity. This review presents a brief overview of how coronaviruses evade innate immunity, according to the current studies about SARS-CoV and middle-east respiratory syndrome-coronavirus (MERS-CoV). The coronaviruses manage to block, escape, or dampen the innate immune response by antagonizing double-stranded RNA (dsRNA) sensor, mitochondrial antiviral-signaling protein (MAVS) and stimulator of IFN genes (STING) pathways, epigenetic modification, posttranslational modifications, and host mRNA translation. We provide novel insights into a comprehensive therapy to combat SARS-CoV-2 infection.


Subject(s)
COVID-19 , Middle East Respiratory Syndrome Coronavirus , Humans , SARS-CoV-2 , Immunity, Innate
6.
Adv Sci (Weinh) ; 10(10): e2205835, 2023 04.
Article in English | MEDLINE | ID: mdl-36739602

ABSTRACT

Cytotoxic chemotherapy is a primary treatment modality for many patients with advanced cancer. Increasing preclinical and clinical observations indicate that chemotherapy can exacerbate tumor metastasis. However, the underlying mechanism remains unclear. Here, it is attempted to identify the mechanisms underlying chemotherapy-induced cancer recurrence and metastasis. It is revealed that a small subpopulation of "near-death cells" (NDCs) with compromised plasma membranes can reverse the death process to enhance survival and repopulation after exposure to lethal doses of cytotoxins. Moreover, these NDCs acquire enhanced tumorigenic and metastatic capabilities, but maintain chemosensitivity in multiple models. Mechanistically, cytotoxin exposure induces activating transcription factor 4 (ATF4)-dependent nonclassical NF-κB signaling activation; ultimately, this results in nuclear translocation of p52 and RelB in NDCs. Deletion of ATF4 in parental cancer cells significantly reduces colony formation and metastasis of NDCs, whereas overexpression of ATF4 activates the nonclassical NF-κB signaling pathway to promote chemotherapy-induced metastasis of NDCs. Overall, these results provide novel mechanistic insights into the chemotherapy-induced metastasis and indicate the pivotal role of NDCs in mediating tumor relapse after cytotoxic therapy. This study also suggests that targeting ATF4 may be an effective approach in improving the efficacy of chemotherapy.


Subject(s)
Antineoplastic Agents , NF-kappa B , Humans , NF-kappa B/metabolism , Activating Transcription Factor 4/metabolism , Neoplasm Recurrence, Local , Signal Transduction
7.
Clin Transl Med ; 13(1): e1166, 2023 01.
Article in English | MEDLINE | ID: mdl-36639835

ABSTRACT

BACKGROUND: Tumour repopulation initiated by residual tumour cells in response to cytotoxic therapy has been described clinically and biologically, but the mechanisms are unclear. Here, we aimed to investigate the mechanisms for the tumour-promoting effect in dying cells and for tumour repopulation in surviving tongue cancer cells. METHODS: Tumour repopulation in vitro and in vivo was represented by luciferase activities. The differentially expressed cytokines in the conditioned medium (CM) were identified using a cytokine array. Gain or loss of function was investigated using inhibitors, neutralising antibodies, shRNAs and ectopic overexpression strategies. RESULTS: We found that dying tumour cells undergoing cytotoxic therapy increase the growth of living tongue cancer cells in vitro and in vivo. Dying tumour cells create amphiregulin (AREG)- and basic fibroblast growth factor (bFGF)-based extracellular environments via cytotoxic treatment-induced endoplasmic reticulum stress. This environment stimulates growth by activating lysine acetyltransferase 6B (KAT6B)-dependent nuclear factor-kappa B (NF-κB) signalling in living tumour cells. As direct targets of NF-κB, miR-22 targets KAT6B to repress its expression, but long noncoding RNAs (lncRNAs) (XLOC_003973 and XLOC_010383) counter the effect of miR-22 to enhance KAT6B expression. Moreover, we detected increased AREG and bFGF protein levels in the blood of tongue cancer patients with X-box binding protein-1 (XBP1) activation in tumours under cytotoxic therapy and found that XBP1 activation is associated with poor prognosis of patients. We also detected activation of miR-22/lncRNA/KAT6B/NF-κB signalling in recurrent cancers compared to paired primary tongue cancers. CONCLUSIONS: We identified the molecular mechanisms of cell death-induced tumour repopulation in tongue cancer. Such insights provide new avenues to identify predictive biomarkers and effective strategies to address cancer progression.


Subject(s)
MicroRNAs , RNA, Long Noncoding , Tongue Neoplasms , Humans , NF-kappa B/genetics , NF-kappa B/metabolism , RNA, Long Noncoding/genetics , Tongue Neoplasms/drug therapy , Tongue Neoplasms/genetics , Neoplasm Recurrence, Local , Cytokines , MicroRNAs/genetics , MicroRNAs/metabolism , Histone Acetyltransferases , X-Box Binding Protein 1/genetics
8.
Cancer Res ; 82(21): 3974-3986, 2022 11 02.
Article in English | MEDLINE | ID: mdl-36069931

ABSTRACT

Resistance to HER2-targeted therapy represents a significant challenge for the successful treatment of patients with breast cancer with HER2-positive tumors. Through a global mass spectrometry-based proteomics approach, we discovered that the expression of the N6-methyladenosine (m6A) demethylase ALKBH5 was significantly upregulated in HER2-targeted therapy-resistant breast cancer cells. Elevated expression of ALKBH5 was sufficient to confer resistance to HER2-targeted therapy, and specific knockdown of ALKBH5 rescued the efficacy of trastuzumab and lapatinib in resistant breast cancer cells. Mechanistically, ALKBH5 promoted m6A demethylation of GLUT4 mRNA and increased GLUT4 mRNA stability in a YTHDF2-dependent manner, resulting in enhanced glycolysis in resistant breast cancer cells. In breast cancer tissues obtained from patients with poor response to HER2-targeted therapy, increased expression of ALKBH5 or GLUT4 was observed and was significantly associated with poor prognosis in the patients. Moreover, suppression of GLUT4 via genetic knockdown or pharmacologic targeting with a specific inhibitor profoundly restored the response of resistant breast cancer cells to trastuzumab and lapatinib, both in vitro and in vivo. In conclusion, ALKBH5-mediated m6A demethylation of GLUT4 mRNA promotes resistance to HER2-targeted therapy, and targeting the ALKBH5/GLUT4 axis has therapeutic potential for treating patients with breast cancer refractory to HER2-targeted therapies. SIGNIFICANCE: GLUT4 upregulation by ALKBH5-mediated m6A demethylation induces glycolysis and resistance to HER2-targeted therapy and represents a potential therapeutic target for treating HER2-positive breast cancer.


Subject(s)
Breast Neoplasms , Female , Humans , AlkB Homolog 5, RNA Demethylase/genetics , Breast Neoplasms/pathology , Demethylation , Glycolysis , Lapatinib/therapeutic use , RNA, Messenger/genetics , Trastuzumab/therapeutic use
9.
J Biochem Mol Toxicol ; 36(11): e23176, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35968984

ABSTRACT

The current study was set out to investigate the mechanism by which silenced long noncoding RNA (lncRNA) colon cancer-associated transcript 2 (CCAT2) modulates the cell growth, migration, invasion, and drug sensitivity of breast cancer (BC) cells to 5-fluorouracil (5-Fu) with the involvement of miR-145 and p53. First, high CCAT2 expression was presented in BC cells and tissues. Subsequently, the links between CCAT2 expression and BC clinicopathological features were analyzed. Highly-expressed CCAT2 was linked to lymph node metastasis, positive progesterone receptor, estrogen receptor, and Ki-67 of BC cells. Then, the gain- and loss-of-function approaches were performed to measure the regulatory role of CCAT2 in the biological processes of BC cells. Silencing of CCAT2 suppressed in vitro cell growth, proliferation, invasion, migration abilities, and epithelial-mesenchymal transformation, increased cell apoptosis, and enhanced drug sensitivity of BC cells. Silencing of CCAT2 upregulated miR-145, which was poorly expressed in drug-resistant BC cells. p53 can bind to the miR-145 promoter region and increase miR-145 expression. Upregulation of miR-145 induced by silencing of CCAT2 can be invalidated by p53-siRNA. To conclude, p53-induced activation of miR-145 could be inhibited by CCAT2, while overexpression of CCAT2 could improve the drug resistance of BC cells to 5-Fu.


Subject(s)
Antimetabolites, Antineoplastic , Breast Neoplasms , Drug Resistance , Fluorouracil , Humans , Apoptosis/genetics , Cell Line, Tumor , Cell Proliferation/genetics , Colonic Neoplasms/genetics , Drug Resistance/genetics , Fluorouracil/pharmacology , Gene Expression Regulation, Neoplastic , MicroRNAs/genetics , MicroRNAs/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Antimetabolites, Antineoplastic/pharmacology
10.
Int J Biol Sci ; 18(11): 4497-4512, 2022.
Article in English | MEDLINE | ID: mdl-35864957

ABSTRACT

YAP (gene symbol YAP1) as a potential oncoprotein, is positively correlated with the malignancy of various tumors. However, overexpression of YAP alone in multiple normal tissue cells has failed to induce tumor formation and the underlying mechanism is poorly understood. Herein, we show that YAP activation directly induces transcription of its negative regulator, SAV1, to constitute a negative feedback loop, which plays a vital role in maintaining lung epithelial cell homeostasis and was dysregulated in non-small cell lung cancer (NSCLC). Notably, smoking promotes the hypermethylation of the SAV1 promoter region, which disrupts YAP negative feedback by inactivating the Hippo pathway. Besides, exogenous overexpression of SAV1 can act as a traffic protein, activating the Hippo signaling and concurrently inhibiting the WNT pathway to decrease cancer cell growth. Furthermore, using the lung cancer organoids, we found that lentivirus-mediated SAV1 gene transfer combined with methylation inhibitor and YAP-TEAD inhibitor is a potential feasible clinical medication regimen for the lung cancer patient, especially among the smoking population. Thus, this SAV1 mediated feedback loop provides an efficient mechanism to establish the robustness and homeostasis of YAP regulation and as a potential target of gene therapy for the smoking NSCLC population.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Cell Cycle Proteins , Lung Neoplasms , Smoke , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Carcinoma, Non-Small-Cell Lung/genetics , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Feedback , Humans , Lung Neoplasms/genetics , Phosphoproteins/metabolism , Promoter Regions, Genetic/genetics , Smoke/adverse effects , Transcription Factors/genetics , Transcription Factors/metabolism
11.
Cell Commun Signal ; 20(1): 92, 2022 06 17.
Article in English | MEDLINE | ID: mdl-35715860

ABSTRACT

BACKGROUND: Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer with poor prognosis and limited treatment. As a major component of the tumor microenvironment, tumor-associated macrophages (TAMs) play an important role in facilitating the aggressive behavior of TNBC. This study aimed to explore the novel mechanism of TAMs in the regulation of epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties in TNBC. METHODS: Expression of the M2-like macrophage marker CD163 was evaluated by immunohistochemistry in human breast cancer tissues. The phenotype of M2 macrophages polarized from Tohoku-Hospital-Pediatrics-1 (THP1) cells was verified by flow cytometry. Transwell assays, wound healing assays, western blotting, flow cytometry, ELISA, quantitative polymerase chain reaction (qPCR), luciferase reporter gene assays, and immunofluorescence assays were conducted to investigate the mechanism by which TAMs regulate EMT and CSC properties in BT549 and HCC1937 cells. RESULTS: Clinically, we observed a high infiltration of M2-like tumor-associated macrophages in TNBC tissues and confirmed that TAMs were associated with unfavorable prognosis in TNBC patients. Moreover, we found that conditioned medium from M2 macrophages (M2-CM) markedly promoted EMT and CSC properties in BT549 and HCC1937 cells. Mechanistically, we demonstrated that chemokine (C-C motif) ligand 2 (CCL2) secretion by TAMs activated Akt signaling, which in turn increased the expression and nuclear localization of ß-catenin. Furthermore, ß-catenin knockdown reversed TAM-induced EMT and CSC properties. CONCLUSIONS: This study provides a novel mechanism by which TAMs promote EMT and enhance CSC properties in TNBC via activation of CCL2/AKT/ß-catenin signaling, which may offer new strategies for the diagnosis and treatment of TNBC. Video Abstract.


Subject(s)
Chemokine CCL2 , Epithelial-Mesenchymal Transition , Neoplastic Stem Cells , Proto-Oncogene Proteins c-akt , Triple Negative Breast Neoplasms , Tumor-Associated Macrophages , beta Catenin , Cell Line, Tumor , Cell Movement , Cell Proliferation , Chemokine CCL2/metabolism , Humans , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/pathology , Tumor Microenvironment , Tumor-Associated Macrophages/metabolism , Tumor-Associated Macrophages/pathology , beta Catenin/metabolism
12.
Oncogenesis ; 11(1): 19, 2022 Apr 22.
Article in English | MEDLINE | ID: mdl-35459265

ABSTRACT

Previously, our lab explored that tongue cancer resistance-associated protein (TCRP1) plays a central role in cancer chemo-resistance and progression. Absolutely, TCRP1 was significantly increased in lung cancer. But the mechanism is far from elucidated. Here, we found that TCRP1 was increased in p53-mutant non-small-cell lung cancer (NSCLC), comparing to that in NSCLC with wild type p53. Further study showed that mutant p53 couldn't bind to the promoter of TCRP1 to inhibit its expression. While the wild type p53 did so. Next, loss-and gain-of-function assays demonstrated that TCRP1 promoted cell proliferation and tumor growth in NSCLC. Regarding the mechanism, TCRP1 encouraged AKT phosphorylation and blocked FOXO3a nuclear localization through favoring FOXO3a ubiquitination in cytoplasm, thus, promoted cell cycle progression. Conclusionly, TCRP1 was upregulated in NSCLC cells with mutant p53. TCRP1 promoted NSCLC progression via regulating cell cycle.

13.
Front Cell Dev Biol ; 9: 670854, 2021.
Article in English | MEDLINE | ID: mdl-34136486

ABSTRACT

Glioma is the most common primary brain tumor with poor prognosis and high mortality. The purpose of this study was to use the epigenetic signature to predict prognosis and evaluate the degree of immune infiltration in gliomas. We integrated gene expression profiles and DNA methylation data of lower-grade glioma and glioblastoma to explore epigenetic differences and associated differences in biological function. Cox regression and lasso analysis were used to develop an epigenetic signature based on eight DNA methylation sites to predict prognosis of glioma patients. Kaplan-Meier analysis showed that the overall survival time of high- and low-risk groups was significantly separated, and ROC analysis verified that the model had great predictive ability. In addition, we constructed a nomogram based on age, sex, 1p/19q status, glioma type, and risk score. The epigenetic signature was obviously associated with tumor purity, immune checkpoints, and tumor-immune infiltrating cells (CD8+ T cells, gamma delta T cells, M0 macrophages, M1 macrophages, M2 macrophages, activated NK cells, monocytes, and activated mast cells) and thus, it may find application as a guide for the evaluation of immune infiltration or in treatment decisions in immunotherapy.

14.
Nat Commun ; 12(1): 2699, 2021 05 11.
Article in English | MEDLINE | ID: mdl-33976188

ABSTRACT

Resistance to Herceptin represents a significant challenge for successful treatment of HER2-positive breast cancer. Here, we show that in Herceptin-sensitive cells, FOXO3a regulates specific miRNAs to control IGF2 and IRS1 expression, retaining basic IGF2/IGF-1R/IRS1 signaling. The basic activity maintains expression of PPP3CB, a subunit of the serine/threonine-protein phosphatase 2B, to restrict FOXO3a phosphorylation (p-FOXO3a), inducing IGF2- and IRS1-targeting miRNAs. However, in Herceptin-resistant cells, p-FOXO3a levels are elevated due to transcriptional suppression of PPP3CB, disrupting the negative feedback inhibition loop formed by FOXO3a and the miRNAs, thereby upregulating IGF2 and IRS1. Moreover, we detect significantly increased IGF2 in blood and IRS1 in the tumors of breast cancer patients with poor response to Herceptin-containing regimens. Collectively, we demonstrate that the IGF2/IGF-1R/IRS1 signaling is aberrantly activated in Herceptin-resistant breast cancer via disruption of the FOXO3a-miRNA negative feedback inhibition. Such insights provide avenues to identify predictive biomarkers and effective strategies overcoming Herceptin resistance.


Subject(s)
Breast Neoplasms/genetics , Forkhead Box Protein O3/genetics , Insulin Receptor Substrate Proteins/genetics , Insulin-Like Growth Factor II/genetics , MicroRNAs/genetics , Receptor, ErbB-2/genetics , Receptor, IGF Type 1/genetics , Animals , Antineoplastic Agents, Immunological/pharmacology , Breast Neoplasms/metabolism , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Calcineurin/genetics , Calcineurin/metabolism , Cell Line, Tumor , Drug Resistance, Neoplasm/genetics , Feedback, Physiological , Female , Forkhead Box Protein O3/metabolism , Gene Expression Regulation, Neoplastic , Humans , Insulin Receptor Substrate Proteins/metabolism , Insulin-Like Growth Factor II/metabolism , Mice , Mice, Nude , MicroRNAs/metabolism , Phosphorylation , Receptor, ErbB-2/metabolism , Receptor, IGF Type 1/metabolism , Signal Transduction , Survival Analysis , Trastuzumab/pharmacology , Tumor Burden/drug effects
15.
Cell Biosci ; 11(1): 68, 2021 Apr 05.
Article in English | MEDLINE | ID: mdl-33820555

ABSTRACT

OBJECTIVE: Breast cancer (BC) remains a public-health issue on a global scale. Long non-coding RNAs (lncRNAs) play functional roles in BC. This study focuses on effects of NEAT1 on BC cell invasion, migration and chemotherapy resistance via microRNA (miR)-141-3p and KLF12. METHODS: After extraction and identification of serum extracellular vesicles (EVs), NEAT1 expression in EVs was detected and its association with clinical characteristics of BC patients was analyzed. Besides, the gain-of function was performed to investigate the roles of NEAT1 and miR-141-3p in BC, and levels of NEAT1, miR-141-3p, KLF12 and MDR1 after EV treatment were detected by RT-qPCR and Western blot analysis. Furthermore, the in vitro findings were confirmed via lung metastases in nude mice. RESULTS: NEAT1 expression in serum EVs was high and related to lymph node metastasis, progesterone receptor, estrogen receptor and Ki-67 in BC patients. After EV treatment, NEAT1 and KLF12 levels were increased, miR-141-3p expression was decreased, the abilities of proliferation, invasion, migration and in vivo metastasis were enhanced, and the sensitivity of cells to cisplatin, paclitaxel and 5-fluorouracil was decreased. After NEAT1 interference, NEAT1 and KLF12 levels in BC cells treated with EVs were decreased, miR-141-3p expression was increased, cell proliferation, invasion, migration and in vivo metastasis were decreased, and drug resistance sensitivity was increased. NEAT1 can bind to miR-141-3p and upregulates KLF12 expression. CONCLUSIONS: EVs inhibit the regulation of KLF12 by miR-141-3p by transporting NEAT1 to BC cells, thus promoting BC cell invasion, migration, and chemotherapy resistance.

16.
Cancer Cell Int ; 21(1): 236, 2021 Apr 26.
Article in English | MEDLINE | ID: mdl-33902601

ABSTRACT

Recent technical advances have led to the discovery of novel functions of extrachromosomal DNA (ecDNA) in multiple cancer types. Studies have revealed that cancer-associated ecDNA shows a unique circular shape and contains oncogenes that are more frequently amplified than that in linear chromatin DNA. Importantly, the ecDNA-mediated amplification of oncogenes was frequently found in most cancers but rare in normal tissues. Multiple reports have shown that ecDNA has a profound impact on oncogene activation, genomic instability, drug sensitivity, tumor heterogeneity and tumor immunology, therefore may offer the potential for cancer diagnosis and therapeutics. Nevertheless, the underlying mechanisms and future applications of ecDNA remain to be determined. In this review, we summarize the basic concepts, biological functions and molecular mechanisms of ecDNA. We also provide novel insights into the fundamental role of ecDNA in cancer.

17.
Oncogene ; 40(4): 777-790, 2021 01.
Article in English | MEDLINE | ID: mdl-33262463

ABSTRACT

Metastasis remains the major obstacle to improved survival for breast cancer patients. Downregulation of FOXO3a transcription factor in breast cancer is causally associated with the development of metastasis through poorly understood mechanisms. Here, we report that FOXO3a is functionally related to the inhibition of VEGF-A/NRP1 signaling and to the consequent suppression of breast cancer metastasis. We show that FOXO3a directly induces miR-29b-2 and miR-338 expression. Ectopic expression of miR-29b-2/miR-338 significantly suppresses EMT, migration/invasion, and in vivo metastasis of breast cancer. Moreover, we demonstrate that miR-29b-2 directly targets VEGF-A while miR-338 directly targets NRP1, and show that regulation of miR-29b-2 and miR-338 mediates the ability of FOXO3a to suppress VEGF-A/NRP1 signaling and breast cancer metastasis. Clinically, our results show that the FOXO3a-miR-29b-2/miR-338-VEGF-A/NRP1 axis is dysregulated and plays a critical role in disease progression in breast cancer. Collectively, our findings propose that FOXO3a functions as a metastasis suppressor, and define a novel signaling axis of FOXO3a-miRNA-VEGF-A/NRP1 in breast cancer, which might be potential therapeutic targets for breast cancer.


Subject(s)
Breast Neoplasms/pathology , Forkhead Box Protein O3/physiology , MicroRNAs/physiology , Neuropilin-1/physiology , Vascular Endothelial Growth Factor A/physiology , Adult , Aged , Animals , Cell Line, Tumor , Female , Humans , Mice , Middle Aged , Neoplasm Invasiveness , Neoplasm Metastasis , Signal Transduction/physiology
18.
Cancer Lett ; 498: 152-164, 2021 02 01.
Article in English | MEDLINE | ID: mdl-33130316

ABSTRACT

Long non-coding RNAs (lncRNAs) have been potentially identified as new diagnostic markers, prognostic factors and therapeutic targets in cancer. The acquisition of a mesenchymal (MES) phenotype in glioblastomas (GBMs) results into therapeutic resistance and poor clinical outcomes. The correlation between lncRNAs and MES differentiation remains elusive. Here, we report that LINC01057 as a lncRNA is overexpressed in GBMs, especially in MES subtype. LINC01057 knockdown suppresses proliferation, invasion and radioresistance of GBM cells in vitro, and tumor growth in vivo. LINC01057 knockdown leads to loss of MES signature in MES subpopulation of GBM cells, but LINC01057 overexpression promotes MES differentiation in proneural (PN) subpopulation. LINC01057 interacts with IKKα and maintains IKKα nucleus localization, leading to effective chromatin accessibility at NF-κB responsive promoters via histone modification and final NF-κB activation. IKKα knockdown disrupts the effect of LINC01057 overexpression on PN to MES transition (PMT). LINC01057 level is negatively correlated with patient prognosis in MES-subtype GBM. Collectively, our findings uncover LINC01057 as a regulator of NF-κB signaling to promote MES differentiation and a potential target for therapeutic intervention for MES-subtype GBM.


Subject(s)
Brain Neoplasms/genetics , Cell Differentiation/genetics , Glioblastoma/genetics , Mesenchymal Stem Cells/pathology , NF-kappa B/genetics , RNA, Long Noncoding/genetics , Signal Transduction/genetics , Brain Neoplasms/pathology , Cell Line , Cell Line, Tumor , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic/genetics , Glioblastoma/pathology , HEK293 Cells , Humans , Neoplastic Stem Cells/pathology , Prognosis
19.
Am J Cancer Res ; 10(11): 3752-3764, 2020.
Article in English | MEDLINE | ID: mdl-33294265

ABSTRACT

TAS-102/Lonsurf is a new oral anti-tumor drug consisting of trifluridine and tipiracil in a 1:0.5 molar ratio. Lonsurf has been approved globally, including US, Europe Union, and China, to treat patients with advanced colorectal cancer. Ongoing clinical trials are currently conducted for the treatment of other solid cancers. However, the therapeutic potential of TAS-102 in hematological malignancies has not been explored. In this study, we investigate the therapeutic efficacy of TAS-102 in multiple myeloma both in vitro and in vivo. We demonstrate that TAS-102 treatment inhibits tumor cell proliferation in six human myeloma cell lines with IC50 values in a range from 0.64 to 9.10 µM. Dot blotting and immunofluorescent staining show that trifluridine is predominately incorporated into genomic DNAs of myeloma cells. TAS-102 treatment induces myeloma cell apoptosis through cell cycle arrest in G1 phase and activation of cGAS-STING signaling in myeloma cells. In the human myeloma xenograft models, TAS-102 treatment reduces tumor progression and prolongs mouse survival. TAS-102 has shown its efficacies in the drug-resistant myeloma cells, and the combination of TAS-102 and bortezomib has a synergistic anti-myeloma activity. Our preclinical studies indicate that TAS-102 is a potential novel agent for myeloma therapy.

20.
J Thorac Dis ; 12(5): 2569-2582, 2020 May.
Article in English | MEDLINE | ID: mdl-32642165

ABSTRACT

BACKGROUND: Lung squamous cell carcinoma (LUSC), as the second frequent subtype of lung cancer, causes lots of mortalities primarily due to a lack of precise prognostic markers and timely treatment intervention. Previous studies have constructed several risk prognostic models based on DNA methylation sites in multiple tumors, whereas, DNA methylation signature of LUSC remains to be built, and its predictive value need to be evaluated. METHODS: The genome-wide DNA methylation data of LUSC samples was obtained from The Cancer Genome Atlas dataset. Univariate Cox analysis and the least absolute shrinkage and selection operator (LASSO) were implemented to identify DNA methylation sites related to overall survival of LUSC patients. Thus, we performed multivariate Cox regression to establish a DNA methylation signature. The Kaplan-Meier (K-M) survival curves and time-dependent receiver operating characteristic (ROC) curves were plotted to estimate the prognostic power of the signature. Comparison with other known prognostic biomarkers, our DNA methylation signature showed higher predictive specificity and sensitivity. In addition, multivariate Cox regression screened out independent prognostic factors and constructed a nomogram. RESULTS: Several statistical methods were performed to construct an 11-DNA methylation signature. LUSC patients were divided into low- and high-risk group based on risk score, and high-risk group had a shorter survival time. According to the results of K-M and ROC analyses, the 11-DNA methylation signature showed significant sensitivity and specificity in predicting the LUSC patients' overall survival. Finally, we integrated some independent prognostic factors (risk score, metastasis stage, and tobacco smoking history) to construct a nomogram, which has excellent prognostic power and may provide guidance for the therapeutic strategies. CONCLUSIONS: We constructed the first risk prognosis model based on DNA methylation site in LUSC, which showed better predictive ability. In addition, a nomogram integrating the DNA methylation signature, metastasis stage, and tobacco smoking history was developed.

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