Showing papers in "Molecular Carcinogenesis in 2019"
TL;DR: This study provides the first evidence of the circ_0006528/miR‐7‐5p/Raf1/MEK/ERK regulatory network in the development of breast cancer and suggests that circ_Thousands6528 is a potential therapeutic target and prognostic predictor for breast cancer.
Abstract: Emerging research has indicated that circular RNAs (circRNAs), a novel class of non-coding RNAs, play a vital role in human tumorigenesis and progression. Our previous results suggested that hsa_circ_0006528 (circ_0006528), a circRNA with an unknown function, mediates adriamycin resistance in human breast cancer cells. However, the role of circ_0006528 in breast cancer progression remains unknown. Here, we investigated the probable involvement of circ_0006528 in breast cancer. We analyzed a cohort of 97 patients and found that circ_0006528 expression was significantly upregulated in human breast cancer tissues compared with that in adjacent non-tumorous tissues and was significantly associated with advanced tumor-node-metastasis (TNM) stage and poor prognosis. In addition, we found that in breast cancer cells, circ_0006528 could promote DNA synthesis and cell proliferation, invasion, and migration. Downregulating circ_0006528 induced G2 phase arrest and cell apoptosis. Further mechanistic studies revealed that circ_0006528 could sponge endogenous miR-7-5p and inhibit its activity. We also identified Raf1, which activates the MAPK/ERK signaling pathway, as a target of miR-7-5p and determined that circ_0006528 promotes breast cancer growth, invasion, and migration by promoting the expression of Raf1 and activates the MAPK/ERK pathway. Thus, this study provides the first evidence of the circ_0006528/miR-7-5p/Raf1/MEK/ERK regulatory network in the development of breast cancer and suggests that circ_0006528 is a potential therapeutic target and prognostic predictor for breast cancer.
95 citations
TL;DR: The lncRNA MALAT1 facilitates a pro‐metastatic phenotype in ovarian cancer by promoting alternative RNA processing and differential expression of anti‐apoptosis and epithelial to mesenchymal transition (EMT)‐related genes.
Abstract: Ovarian cancer metastasizes via direct seeding, whereby cancer cells shed from the primary site, resist cell death in the peritoneal cavity, then metastasize to peritoneal organs. We sought to identify molecular mechanisms that facilitate ovarian cancer cell anchorage independent survival. Gene expression profiling was performed on ovarian cancer cells grown in attached or forced suspension culture and confirmed by RT-qPCR. Anoikis was measured by Caspase 3/7 assay. Since the long non-coding RNA Metastasis Associated Lung Adenocarcinoma transcript 1 (MALAT1) was among the transcripts most highly increased in forced suspension culture, modified anti-sense oligonucleotides (ASO) were used to inhibit its expression. Knockdown of RBFOX2 and KIF1B was performed using shRNAs. Publically available datasets were analyzed for association of MALAT1 gene expression with clinicopathological variables. In multiple anoikis-resistant ovarian cancer cell lines MALAT1 expression increased after 24 and 48 h in forced suspension culture compared to attached culture. High MALAT1 is associated with increased stage, recurrence, and reduced survival in ovarian cancer, and in a small percentage of ovarian cancers MALAT1 is amplified. MALAT1 knockdown resulted in decreased proliferation, invasion, anchorage-independent growth, and increased anoikis. Suppression of MALAT1 also resulted in decreased expression of RBFOX2, and alternative processing of the pro-apoptotic tumor suppressor gene KIF1B. RBFOX2 suppression resulted in preferential splicing of the pro-apoptotic isoform of KIF1B (KIFB1B-beta) and increased anoikis. The lncRNA MALAT1 facilitates a pro-metastatic phenotype in ovarian cancer by promoting alternative RNA processing and differential expression of anti-apoptosis and epithelial to mesenchymal transition (EMT)-related genes.
87 citations
TL;DR: The data suggested that the crosstalk between bile acids and the gut microbiota mediated intestinal carcinogenesis, which might provide novel therapeutic strategies against intestinal tumor development, is suggested.
Abstract: The gut microbiota and the bile acid pool play pivotal roles in maintaining intestinal homeostasis. Bile acids are produced in the liver from cholesterol and metabolized in the intestine by the gut microbiota. Gut dysbiosis has been reported to be associated with colorectal cancer. However, the interplay between bile acid metabolism and the gut microbiota during intestinal carcinogenesis remains unclear. In the present study, we investigated the potential roles of bile acids and the gut microbiota in the cholic acid (CA; a primary bile acid)-induced intestinal adenoma-adenocarcinoma sequence. Apc min/+ mice, which spontaneously develop intestinal adenomas, were fed a diet supplemented with 0.4% CA for 12 weeks. Mice that were fed a normal diet were regarded as untreated controls. In CA-treated Apc min/+ mice, the composition of the gut microbiota was significantly altered, and CA was efficiently transformed into deoxycholic acid (a secondary bile acid) by the bacterial 7α-dehydroxylation reaction. The intestinal adenoma-adenocarcinoma sequence was observed in CA-treated Apc min/+ mice and was accompanied by an impaired intestinal barrier function and IL-6/STAT3-related low-grade inflammation. More importantly, microbiota depletion using an antibiotic cocktail globally compromised CA-induced intestinal carcinogenesis, suggesting a leading role for the microbiota during this process. Overall, our data suggested that the crosstalk between bile acids and the gut microbiota mediated intestinal carcinogenesis, which might provide novel therapeutic strategies against intestinal tumor development.
68 citations
TL;DR: It is found that the hypoxic cervical TME educated the recruited macrophages to transform into the M2 phenotype, and interfering with Nrp‐1 may be a potential therapeutic strategy in treating cervical cancer.
Abstract: To explore the mechanisms through which hypoxic tumor microenvironment (TME) modulates the transition of tumor-associated macrophages (TAMs). The migration ability of RAW264.7 macrophages was determined by transwell assay. Flow cytometric, western blot and immunofluorescence analyses of CD206 further validated the M2 polarization of macrophages. Immunofluorescence, western blot and qRT-PCR were performed to detect the expression of neuropilin-1 (Nrp-1) and carbonic anhydrase IX (CAIX). An intermittent hypobaric hypoxia (IH) animal model was established to evaluate the role of hypoxia in activating M2-like TAMs in vivo. We also used immunohistochemistry to analyze the association between CAIX, CD163+ macrophages and Nrp-1 in a series of 72 human cervical cancer specimens. We found that the hypoxic cervical TME educated the recruited macrophages to transform into the M2 phenotype. Nrp-1 expression was significantly increased in hypoxia-primed cervical cancer cells. Blocking Nrp-1 expression prevented hypoxic cells from recruiting and polarizing macrophages towards the M2 phenotype. Hypoxia exposure significantly increased the expression of Nrp-1 as well as the infiltration of macrophages in vivo. Consistently, immunochemical staining in serial tissue sections of cervical cancer revealed upregulated levels of Nrp-1 in CAIX-positive hypoxic regions along with a concurrent significant elevation of M2 macrophages. Nrp-1 and M2-like TAMs were related to the malignant properties of cervical cancer, such as the FIGO stage and lymph node metastasis. Nrp-1 plays critical roles in hypoxic TME-induced activation and pro-tumoral effects of TAMs in cervical cancer. Interfering with Nrp-1 may be a potential therapeutic strategy in treating cervical cancer.
66 citations
TL;DR: Mechanistic investigation indicated that vascular endothelial growth factor A (VEGF‐A, VEGF) plays a crucial role during DANCR inhibition of tumor angiogenesis in ovarian cancer, and results demonstrated that miR‐145 is the direct binding target of DAN CR during regulation of V EGF expression and tumor ang iogenesis in Ovarian cancer cells.
Abstract: Differentiation antagonizing non-protein coding RNA (DANCR) is a newly identified oncogenic long noncoding RNA found in various cancers. However, the functional role of DANCR in tumor angiogenesis and the underlying mechanisms are still unclear. The expression of DANCR was determined in ovarian malignant tissues and cell lines. The functional role of DANCR in tumor angiogenesis was revealed by the following methods: CD31 staining of ovarian tumor tissues, matrigel-plug assay tissues, HUVEC-related tube formation assay, and invasion assay. Enzyme-linked immunosorbent assay, Western blotting, luciferase assay, and rescue experiments were used to investigate the underlying mechanisms of DANCR-regulating angiogenesis. DANCR was upregulated in ovarian malignant tissues and ovarian cancer cells. Knockdown of DANCR efficiently impaired ovarian tumor growth through inhibition of tumor angiogenesis. Furthermore, the conditional culture medium from DANCR-knockdown ovarian cells significantly inhibited tube formation and invasion of HUVEC in vitro. Mechanistic investigation indicated that vascular endothelial growth factor A (VEGF-A, VEGF) plays a crucial role during DANCR inhibition of tumor angiogenesis in ovarian cancer. Further results demonstrated that miR-145 is the direct binding target of DANCR during regulation of VEGF expression and tumor angiogenesis in ovarian cancer cells. Collectively, DANCR plays a promotional role in tumor angiogenesis in ovarian cancer through regulation of miR-145/VEGF axis. Therefore, DANCR may be a novel therapy target for ovarian cancer.
63 citations
TL;DR: There was a significant negative correlation between CD82 expression in tissues and CD82 content in exosomes, which indicated thatCD82 expression was redistributed from tissues to the blood with the development and metastasis of breast cancer.
Abstract: CD82, a member of the tetraspanin superfamily, has been proposed to exert its activity via tetra-transmembrane protein enriched microdomains (TEMs) in exosomes. The present study aimed to explore the potential of the exosome protein CD82 in diagnosing breast cancers of all stages and various histological subtypes in patients. The results strongly suggest that CD82 expression in breast cancer tissue was significantly lower than that in healthy and benign breast disease tissues. There was a significant negative correlation between CD82 expression in tissues and CD82 content in exosomes, which indicated that CD82 expression was redistributed from tissues to the blood with the development and metastasis of breast cancer.
63 citations
TL;DR: It is demonstrated that Wnt signaling can mediate PARPi resistance in HGSOC and provides a clinical rationale for combining PARP and Wnt inhibitors.
Abstract: Epithelial ovarian cancer (EOC) has one of the highest death to incidence ratios among all cancers. High grade serous ovarian carcinoma (HGSOC) is the most common and deadliest EOC histotype due to the lack of therapeutic options following debulking surgery and platinum/taxane-based chemotherapies. For recurrent chemosensitive HGSOC, poly(ADP)-ribose polymerase inhibitors (PARPi; olaparib, rucaparib, or niraparib) represent an emerging treatment strategy. While PARPi are most effective in homologous recombination DNA repair-deficient (HRD) HGSOCs, recent studies have observed a significant benefit in non-HRD HGSOCs. However, all HGSOC patients are likely to acquire resistance. Therefore, there is an urgent clinical need to understand PARPi resistance and to introduce novel combinatorial therapies to manage PARPi resistance and extend HGSOC disease-free intervals. In a panel of HGSOC cell lines, we established matched olaparib sensitive and resistant cells. Transcriptome analysis of the matched olaparib-sensitive vs -resistant cells revealed activation of the Wnt signaling pathway and consequently increased TCF transcriptional activity in PARPi-resistant cells. Forced activation of canonical Wnt signaling in several PARPi-sensitive cells via WNT3A reduced olaparib and rucaparib sensitivity. PARPi resistant cells were sensitive to inhibition of Wnt signaling using the FDA-approved compound, pyrvinium pamoate, which has been shown to promote downregulation of β-catenin. In both an HGSOC cell line and a patient-derived xenograft model, we observed that combining pyrvinium pamoate with olaparib resulted in a significant decrease in tumor burden. This study demonstrates that Wnt signaling can mediate PARPi resistance in HGSOC and provides a clinical rationale for combining PARP and Wnt inhibitors.
62 citations
TL;DR: In vivo experiments showed that knockdown of DSCAM‐AS1 decreased the tumorigenesis of BC cells, increased the expression of miR‐204‐5p, and may serve as novel therapeutic targets for BC.
Abstract: Breast cancer (BC) is a common malignancy worldwide. More than 3 700 000 women die of BC every year. DSCAM-AS1 was overexpressed several kinds of cancer and miR-204-5p was lowly expressed, which indicated that miR-204-5p had anti-tumor activity and DSCAM-AS1 had pro-tumor activity. We intended to analyze DSCAM-AS1, miR-204-5p, and ribonucleotide reductase M2 (RRM2). Microarray analysis and quantitative Real Time fluorescence Polymerase Chain Reaction (qRT-PCR) were employed to determine DSCAM-AS1 and miR-204-5p expression. Luciferase reporter assay was applied to examine the target relationship between DSCAM-AS1, miR-204-5p, and RRM2. Cell Counting Kit-8 (CCK-8 assay), transwell assay, and flow cytometry were used to detect cell proliferation, invasion, and apoptosis. The expression of DSCAM-AS1, miR-204-5p, and RRM2 were confirmed by Western blot. We also conducted in vivo assay to verify the effect of DSCAM-AS1. DSCAM-AS1 was up-regulated, while miR-204-5p was down-regulated in BC tissues and cells. DSCAM-AS1 directly targeted miR-204-5p. DSCAM-AS1 promoted the proliferation and invasion of BC cells by reducing miR-204-5p and inhibiting miR-204-5p expression. DSCAM-AS1 expression was related to the expression of RRM2, and miR-204-5p could reverse the function of DSCAM-AS1. RRM2 was up-regulated in BC cells, and miR-204-5p inhibited RRM2 expression by targeting RRM2. Overexpression of RRM2 stimulated proliferation and cell invasion and impeded apoptosis. In vivo experiments showed that knockdown of DSCAM-AS1 decreased the tumorigenesis of BC cells, increased the expression of miR-204-5p. DSCAM-AS1 promoted proliferation and impaired apoptosis of BC cells by reducing miR-204-5p and enhancing RRM2 expression. DSCAM-AS1/miR-204-5p/RRM2 may serve as novel therapeutic targets for BC.
61 citations
TL;DR: A novel mechanism by which CCAT1 promotes cell proliferation and enhances drug resistance by regulating the miR‐143/PLK1/BUBR1 signaling axis both in vitro and in vivo is discovered.
Abstract: Recent evidence indicates that long noncoding RNA colon cancer-associated transcript-1 (lncRNA CCAT1) is abundantly expressed in esophageal cancer and is closely related to the occurrence, development, invasion, metastasis, and drug resistance of this disease. However, the role and molecular mechanisms of CCAT1 in the cell proliferation and chemoresistance of esophageal cancer are largely unknown. The correlation between CCAT1 expression and drug resistance to cisplatin (CDDP) in esophageal squamous cell carcinoma (ESCC) cells was analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and quantitative real-time polymerase chain reaction (qRT-PCR) assays. CCAT1 knockdown and miR-143 overexpression or inhibition were used to verify the effects on proliferation and drug resistance via MTT, western blotting, flow cytometry, and immunofluorescence assays. qRT-PCR and western blotting were applied to detect the potential regulatory relationship among CCAT1, miR-143, PLK1, and BUBR1. A xenograft tumor assay was performed to validate the role of CCAT1 in vivo. The expression of CCAT1 was positively correlated with drug resistance in several ESCC cell lines. CCAT1 knockdown and miR-143 overexpression inhibited cell proliferation and CDDP drug resistance. Moreover, the downstream target of CCAT1 was found to be miR-143, which can regulate the expression of PLK1 and BUBR1. In vivo assays showed that CCAT1 knockdown suppressed tumor growth and enhanced the sensitivity of tumors to CDDP in nude mice. Taken together, we discovered a novel mechanism by which CCAT1 promotes cell proliferation and enhances drug resistance by regulating the miR-143/PLK1/BUBR1 signaling axis both in vitro and in vivo. Our findings further suggest that lncRNA CCAT1 may be a potential therapeutic target for overcoming chemoresistance in esophageal cancer.
50 citations
TL;DR: Alantolactone, a natural sesquiterpene lactone, potently inhibited human pancreatic cancer cells and suppressed constitutively activated STAT3, and suggested that Alantolactsone could sensitize human pancreatIC cancer cells to EGFR inhibitors possibly through down‐regulating the STAT3 signaling.
Abstract: Several studies have implicated the feedback activation of signal transducer and activator of transcription 3 (STAT3) as a new cancer drug-resistance mechanism and linked it to the failure of epidermal growth factor receptor (EGFR)-targeted therapies. In this study, we discovered that Alantolactone, a natural sesquiterpene lactone, potently inhibited human pancreatic cancer cells and suppressed constitutively activated STAT3. In contrast, Alantolactone had little effect on the EGFR pathway. Moreover, combination of Alantolactone and an EGFR inhibitor, Erlotinib or Afatinib, demonstrated a remarkable synergistic anti-cancer effect against pancreatic cancer cells both in vitro and in vivo. Our results suggested that Alantolactone could sensitize human pancreatic cancer cells to EGFR inhibitors possibly through down-regulating the STAT3 signaling. Alantolactone, when combined with other EGFR targeted agents, could be further developed as a potential therapy for pancreatic cancer.
45 citations
TL;DR: The findings indicate that targeting the HA‐CD44/RHAMM signaling pathway could be a promising approach for the prevention and therapy of lung cancer.
Abstract: Although members of the hyaluronan (HA)-CD44/HA-mediated motility receptor (RHAMM) signaling pathway have been shown to be overexpressed in lung cancer, their role in lung tumorigenesis is unclear. In the present study, we first determined levels of HA and its receptors CD44 and RHAMM in human non-small cell lung cancer (NSCLC) cells and stromal cells as well as mouse lung tumors. Subsequently, we examined the role of HA-CD44/RHAMM signaling pathway in mediating the proliferation and survival of NSCLC cells and the cross-talk between NSCLC cells and normal human lung fibroblasts (NHLFs)/lung cancer-associated fibroblasts (LCAFs). The highest levels of HA and CD44 were observed in NHLFs/LCAFs followed by NSCLC cells, whereas THP-1 monocytes/macrophages showed negligible levels of both HA and CD44. Simultaneous silencing of HA synthase 2 (HAS2) and HAS3 or CD44 and RHAMM suppressed cell proliferation and survival as well as the EGFR/AKT/ERK signaling pathway. Exogenous HA partially rescued the defect in cell proliferation and survival. Moreover, conditioned media (CM) generated by NHLFs/LCAFs enhanced the proliferation of NSCLC cells in a HA-dependent manner as treatment of NHLFs and LCAFs with HAS2 siRNA, 4-methylumbelliferone, an inhibitor of HASs, LY2228820, an inhibitor of p38MAPK, or treatment of A549 cells with CD44 blocking antibody suppressed the effects of the CM. Upon incubation in CM generated by A549 cells or THP-1 macrophages, NHLFs/LCAFs secreted higher concentrations of HA. Overall, our findings indicate that targeting the HA-CD44/RHAMM signaling pathway could be a promising approach for the prevention and therapy of lung cancer.
TL;DR: It is demonstrated that GTP/EGCG mediate epigenetic reactivation of TIMP‐3 that plays a key role in suppressing invasiveness and cancer progression and restoring the MMP:TIMP balance suppresses prostate cancer progression.
Abstract: Green tea polyphenols (GTPs) and their major constituent, epigallocatechin-3-gallate (EGCG), have been reported to demonstrate many interesting biological activities, including anticancer properties. Recent studies on prostate cancer provide strong evidence that epigenetic mechanisms are major players in the regulation of matrix metalloproteinases (MMPs) and their binding partner tissue inhibitor of MMPs (TIMPs) involved in prostate cancer progression. Here we demonstrate that GTP/EGCG mediate epigenetic reactivation of TIMP-3 that plays a key role in suppressing invasiveness and cancer progression. Treatment of human prostate cancer DUPRO and LNCaP cells with 10 µg/mL GTP and 20 µM EGCG induced TIMP-3 mRNA and protein expression. This transcriptional activation of TIMP-3 was associated with the decrease in the expression of both enhancers of zeste homolog 2 (EZH2) and its catalytic product trimethylation of histone H3 at lysine 27 (H3K27me3) repressive marks at the TIMP-3 promoter with an accompanying increase in histone H3K9/18 acetylation. In addition, GTP/EGCG treatment significantly reduced class I histone deacetylase (HDAC) activity/expression and EZH2 and H3K27me3 levels in prostate cancer cells. EGCG/GTP exposure also reduced MMP-2/MMP-9 gelatinolytic activity and abrogated invasion and migration capabilities in these cells. Silencing of EZH2 and class I HDACs strikingly increased the expression of TIMP-3 independent of DNA methylation. Furthermore, clinical trials performed on patients undergoing prostatectomy consuming 800 mg EGCG (Polyphenon E) up to 6 weeks and grade-matched controls demonstrate an increase in plasma TIMP-3 levels. A marked reduction in class I HDACs activity/expression and EZH2 and H3K27me3 levels were noted in GTP-supplemented prostate tissue. Our findings highlight that TIMP-3 induction, as a key epigenetic event modulated by green tea in restoring the MMP:TIMP balance suppresses prostate cancer progression.
TL;DR: It is suggested that miR‐142‐3p within LAC EVs can be transferred from LAC cells to both endothelial and fibroblast cells to promote tumor associated changes.
Abstract: Extracellular vesicles (EVs) are mediators of communication between cancer cells and the surrounding tumor microenvironment. EV content is able to influence key tumorigenic changes including invasion, metastasis, and inducing pro-tumor changes in the stroma. MiR-142-3p is a known tumor suppressor in LAC and was recently shown to be enriched within LAC EVs, indicating its potential as a key signaling miRNA. Our research demonstrates the role EV associated miR-142-3p plays when transferred from LAC cells to both endothelial and fibroblast cells. We demonstrate that transfer of miR-142-3p in LAC EVs to endothelial cells promotes angiogenesis through inhibition of TGFβR1. Additionally, we show EV associated miR-142-3p promotes the cancer-associated fibroblast phenotype in lung fibroblast cells which we show is independent of TGFβ signaling. These findings suggest that miR-142-3p within LAC EVs can be transferred from LAC cells to both endothelial and fibroblast cells to promote tumor associated changes.
TL;DR: These findings suggest that Wnt signaling is initiated in cancer cells which then activate CAFs, and in turn perpetuate a paracrine signaling loop, which suggests that targeting WNT signaling in the TME is essential.
Abstract: Wnt pathway activation maintains the cancer stem cell (CSC) phenotype and promotes tumor progression, making it an attractive target for anti-cancer therapy. Wnt signaling at the tumor and tumor microenvironment (TME) front have not been investigated in depth in head and neck squamous cell carcinoma (HNSCC). In a cohort of 48 HNSCCs, increased Wnt signaling, including Wnt genes (AXIN2, LGR6, WISP1) and stem cell factors (RET, SOX5, KIT), were associated with a more advanced clinical stage. Key Wnt pathway proteins were most abundant at the cancer epithelial-stromal boundary. To investigate these observations, we generated three pairs of cancer-cancer associated fibroblast (CAF) cell lines derived from the same HNSCC patients. 3D co-culture of cancer spheres and CAFs mimicked these in vivo interactions, and using these we observed increased expression of Wnt genes (eg, WNT3A, WNT7A, WNT16) in both compartments. Of these Wnt ligands, we found Wnt3a, and less consistently Wnt16, activated Wnt signaling in both cancer cells and CAFs. Wnt activation increased CSC characteristics like sphere formation and invasiveness, which was further regulated by the presence of CAFs. Time lapse microscopy also revealed preferential Wnt activation of cancer cells. Wnt inhibitors, OMP-18R5 and OMP-54F28, significantly reduced growth of HNSCC patient-derived xenografts and suppressed Wnt activation at the tumor epithelial-stromal boundary. Taken together, our findings suggest that Wnt signaling is initiated in cancer cells which then activate CAFs, and in turn perpetuate a paracrine signaling loop. This suggests that targeting Wnt signaling in the TME is essential.
TL;DR: It is concluded that CDDP plus DAPT was able to sensitize CDDP‐resistant human OS cells to CDDP by downregulation of Notch signaling, and CDDP and D APT combination treatment may be effective and promising for advanced OS.
Abstract: Overcoming platinum drug resistance represents a major clinical challenge in osteosarcoma (OS) treatment. The high rates and patterns of therapeutic failure seen in patients are consistent with a steady accumulation of drug-resistant cancer stem cells (CSCs). Notch signaling is implicated in regulating CSCs and tumor resistance to platinum. Thus, we attempt to investigate whether inhibiting of Notch pathway could sensitize cisplatin (CDDP) to CDDP-resistant OS cells and the underlying molecular mechanisms. OS cell lines resistant to CDDP were treated with DAPT, CDDP or combination, we present evidences that DAPT enhances the cytotoxic effect of CDDP in resistant OS by inhibiting proliferation, resulting in G0/G1 cell-cycle arrest, inducing apoptosis, and reducing motility. In addition, DAPT targeting depletes OS stem cells (OSCs), thus increasing tumor sensitivity to platinum, which indicating that a dual combination targeting both OSCs and the bulk of tumor cells are needed for tumor eradication. We also found that the combination of CDDP and DAPT exhibit additive suppression on phosphorylated AKT and ERK, contributing to the anti-cancer effects. In animal model, this combination therapy inhibits the growth and metastasis of CDDP resistant tumor xenografts in nude mice to a greater extent than treatment with either reagent alone. Based on these results, we conclude that CDDP plus DAPT was able to sensitize CDDP-resistant human OS cells to CDDP by downregulation of Notch signaling. CDDP and DAPT combination treatment may be effective and promising for advanced OS.
TL;DR: Linc00161 regulated the drug resistance of ovarian cancer via modulating microRNA‐128/MAPK1 and inhibited the tumor growth by demonstrated by xenograft tumor model in vivo.
Abstract: This study aimed to investigate the regulatory mechanism of linc00161/miR-128/MAPK1 axis on drug resistance of ovarian cancer. Methods: the differentially expressed lncRNAs were screened based on microarray analysis. The expression of linc00161, miR-128 and MAPK1 in ovarian cancer-resistant tissues and cells was tested qRT-PCR, whereas MAPK1 protein expression was examined via western blot in the ovarian cancer resistant cells. The targeted relationship between miR-128 and linc00161 as well as the relationship between miR-128 and MAPK1 were testified by Dual luciferase gene reporter assay. The influence of miR-128 and MAPK1 on the proliferation of ovarian cancer-resistant cells was demonstrated by CCK-8 and colony formation assay. The effect of linc00161 on ovarian cancer was demonstrated by xenograft tumor model in vivo. Results: Linc00161 was highly expressed in ovarian cancer-resistant tissues and SKOV3/DDP cells while the miR-128 displayed a lower expression. Overexpression of linc00161 increased the colony formation ratio in SKOV3 cells, whereas sh-linc00161 reduced colony formation ratio in SKOV3/DDP cells. MAPK1 was highly expressed in ovarian cancer-resistant tissues and cells and could be regulated by linc00161 and miR-128. The proliferation ability of SKOV3 cell was enhanced after transfected with miR-128 inhibitor, whereas that of SKOV3/DDP cells was attenuated by miR-128 mimics. In addition, the colony formation ratio of SKOV3 cells co-transfected with DDP + MAPK1 + sh-linc00161 decreased. The colony formation ratio of SKOV3/DDP cells also declined after transfected with DDP+ MAPK1. Linc00161 regulated the drug resistance of ovarian cancer via modulating microRNA-128/MAPK1. In vivo, sh-linc00161 inhibited the tumor growth.
TL;DR: It is revealed that piR‐39980 has a strong anti‐tumor effect and hence could be a promising RNA‐based therapeutic agent for the malignancy of fibrosarcoma.
Abstract: P-element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a promising class of small regulatory RNAs, earlier believed to control transposable elements (TEs) activity in germlines are now reported in somatic and cancer cells. The aberrant expression of piRNAs has been documented in various cancers wherein they modulate tumorigenesis either as oncogenes or tumor suppressors by curbing target gene expression. However, there is no report yet on the association of piRNAs in fibrosarcoma, an early metastatic lethal tumor. For the first time, we reported a piRNA, piR-39980 in fibrosarcoma and investigated its potential role in malignancy by employing several methods such as qRT-PCR, MTT assay, transwell invasion and migration assay, wound healing assay, flow cytometric cell cycle analysis, Annexin V-PE apoptosis assay, AO/EB dual staining assay, and chromatin condensation assay. We observed that piR-39980 significantly attenuated proliferation, migration, invasion, and colony forming ability as well as induced apoptotic cell death of HT1080 fibrosarcoma cells when transiently overexpressed with its piRNA mimics. The dual luciferase reporter assay confirmed that piR-39980 promotes apoptosis and inhibits proliferation in fibrosarcoma by repressing RRM2 through direct targeting at its 3'UTR through extensive sequence complementary binding, unlike microRNA targeting. In summary, this study revealed that piR-39980 has a strong anti-tumor effect and hence could be a promising RNA-based therapeutic agent for the malignancy of fibrosarcoma.
TL;DR: It is demonstrated that the circ‐PKD2/miR‐204‐3p/APC2 axis represents a novel pathway involved in the pathogenesis of OSCC and may serve as a novel therapeutic target ofOSCC.
Abstract: Recent findings have shown that dysregulation of circular RNAs (circRNAs) is implicated in various cancers. However, the contribution of circRNAs in oral squamous cell carcinoma (OSCC) remains largely unexplored. We screened circRNA expression profiles using a circRNA microarray in paired OSCC and normal tissues and explored the clinical significance of a downregulated circRNA, circ-PKD2. Moreover, the biological function of circ-PKD2 in OSCC was investigated both in vitro and in vivo. We found that downregulation of circ-PKD2 in OSCC correlated significantly with aggressive characteristics. Further analysis revealed that overexpression of circ-PKD2 inhibited OSCC cell proliferation, migration and invasion, induced apoptosis and cell cycle arrest, which were promoted by knockdown of circ-PKD2. In addition, circ-PKD2 was identified as a sponge for miR-204-3p and upregulated the expression of adenomatous polyposis coli 2 (APC2), which was the functional target of miR-204-3p. Moreover, circ-PKD2 attenuated the oncogenic effects of miR-204-3p-mediated APC2 on OSCC progression via multiple signaling pathways. These results demonstrate that the circ-PKD2/miR-204-3p/APC2 axis represents a novel pathway involved in the pathogenesis of OSCC and may serve as a novel therapeutic target of OSCC.
TL;DR: Mechanistically, bioinformatic and luciferase reporter analysis identified Ras‐related C3 botulinum toxin substrate 1 (RAC1) as a direct target of miR‐365 and could inhibit HCC cells dedifferentiation and liver CSCs expansion by targeting RAC1 signaling.
Abstract: Liver cancer stem cells (CSCs) were involved in tumorigenesis, progression, recurrence, and drug resistance of hepatocellular carcinoma (HCC) miR-365 was downregulated in hepatocellular carcinoma and inhibited HCC cell proliferation and invasion However, the role of miR-365 in liver cancer stem cells was unknown Herein, we observed a remarkable decrease of miR-365 expression in CD133 or EpCAM-positive liver CSCs as well as in CSC-enriched hepatoma spheres Up-regulated miR-365 suppressed liver CSC expansion by inhibiting the dedifferentiation of hepatoma cells and decreasing the self-renewal ability of liver CSCs Mechanistically, bioinformatic and luciferase reporter analysis identified Ras-related C3 botulinum toxin substrate 1 (RAC1) as a direct target of miR-365 Overexpression of miR-365 in hepatoma cells downregulated the RAC1 mRNA and protein expression RAC1 also could promote the expansion of liver CSCs The special RAC1 inhibitor EHop-106 or RAC1 overexpression abolished the discrepancy in liver CSC proportion and the self-renewal capacity between miR-365 overexpression hepatoma cells and control cells, which further confirmed that RAC1 was required in miR-365-suppressed liver CSCs expansion miR-365 was downregulated in liver CSCs and could inhibit HCC cells dedifferentiation and liver CSCs expansion by targeting RAC1 signaling
TL;DR: LncRNA MALAT1/miR‐194‐5p/ACVR2B signaling was regarded as a candidate pathway for modulating KIRC progression and was associated with larger tumor size, advanced TNM stage and poor prognosis of KIRC patients.
Abstract: This investigation was purposed to extrapolate whether and how lncRNA MALAT1, miR-194-5p, and ACVR2B altered development of clear cell kidney carcinoma (KIRC). We totally gathered 318 pairs of KIRC tissues and adjacent normal tissues, and also purchased human KIRC cell lines and normal human proximal tubular epithelial cell line. Besides, si-MALAT1, pcDNA-MALAT1, miR-194-5p mimic, miR-194-5p inhibitor, and negative control (NC) were, respectively, transfected into KIRC cells. The viability, proliferation, and apoptosis of the cells were determined with CCK-8 assay, colony formation assay, and flow cytometry. Dual-luciferase reporter gene assay was implemented to validate the targeted relationships between MALAT1 and miR-194-5p, as well as between miR-194-5p and ACVR2B. The results showed that highly expressed MALAT1, ACVR2B, and lowly expressed miR-194-5p were associated with larger tumor size (≥4 cm), advanced TNM stage and poor prognosis of KIRC patients, when, respectively, compared with lowly expressed MALAT1, ACVR2B, and highly expressed miR-194-5p (P < 0.05). Transfection of pcDNA-MALAT1, miR-194-5p inhibitor, and pcDNA-ACVR2B conferred the KIRC cells with promoted viability and proliferation, as well as reduced apoptosis (P < 0.05). Treatment of rats with pcDNA-MALAT1, miR-194-5p inhibitor, or pcDNA-ACVR2B also contributed to larger tumor size growing in them (P < 0.05). Moreover, MALAT1 could directly target miR-194-5p to suppress its expression, and ACVR2B was the targeted molecule of miR-194-5p (P < 0.05). Finally, ACVR2B could reverse the effects exerted by miR-194-5p on viability, proliferation, and apoptosis of KIRC cells (P < 0.05). In conclusion, LncRNA MALAT1/miR-194-5p/ACVR2B signaling was regarded as a candidate pathway for modulating KIRC progression.
TL;DR: Evidence suggesting that TG2 has a role in human cancer is presented, what is known about the TG2 mechanism of action in a range of cancer types is summarized, and TG2 as a cancer therapy target is discussed.
Abstract: Transglutaminase 2 (TG2) has emerged as a key cancer cell survival factor that drives epithelial to mesenchymal transition, angiogenesis, metastasis, inflammation, drug resistance, cancer stem cell survival and stemness, and invasion and migration. TG2 can exist in a GTP-bound signaling-active conformation or in a transamidase-active conformation. The GTP bound conformation of TG2 contributes to cell survival and the transamidase conformation can contribute to cell survival or death. We present evidence suggesting that TG2 has a role in human cancer, summarize what is known about the TG2 mechanism of action in a range of cancer types, and discuss TG2 as a cancer therapy target.
TL;DR: A synopsis of the current landscape of telomeres and telomerase processing in cancer development and how this new knowledge may improve outcomes for patients with cancer is provided.
Abstract: Engaging a telomere maintenance mechanism during DNA replication is essential for almost all advanced cancers. The conversion from normal and premalignant somatic cells to advanced malignant cells often results (85%-90%) from the reactivation of the functional ribonucleoprotein holoenzyme complex, referred to as telomerase. Modulation of the human telomerase reverse transcriptase (hTERT) appears to be rate limiting to produce functional telomerase and engage a telomere maintenance mechanism. The remaining 10% to 15% of cancers overcome progressively shortened telomeres by activating an alternative lengthening of telomeres (ALT) maintenance mechanism, through a DNA recombination pathway. Exploration into the specific mechanisms of telomere maintenance in cancer have led to the development of drugs such as Imetelstat (GRN163L), BIBR1532, 6-thio-dG, VE-822, and NVP-BEZ235 being investigated as therapeutic approaches for treating telomerase and ALT tumors. The successful use of 6-thio-dG (a nucleoside preferentially recognized by telomerase) that targets and uncaps telomeres in telomerase positive but not normal telomerase silent cells has recently shown impressive effects on multiple types of cancer. For example, 6-thio-dG overcomes therapy-resistant cancers in a fast-acting mechanism potentially providing an alternative or additional route of treatment for patients with cancer. In this perspective, we provide a synopsis of the current landscape of telomeres and telomerase processing in cancer development and how this new knowledge may improve outcomes for patients with cancer.
TL;DR: This work identified LncRNAs associated with the immune system and showed the presence of prognostic subtypes of KIRC patients based on immune‐related LncRNA expression and identified a novel immune Lnc RNA based gene‐signature for K IRC patients’ prognostication.
Abstract: Kidney Renal Clear Cell Carcinoma (KIRC) is a significant cause of cancer-related deaths. Here, we aim to identify the LncRNAs associated with the immune system and characterise their clinical utility in KIRC. A total of 504 patients' data was used from TCGA-GDC. In silico correlation analysis identified 143 LncRNAs associated with immune-related genes (r > 0.7, P < 0.05). K-means consensus method clustered KIRC samples in three immune clusters, namely cluster C1, C2, and C3 based on the expression of 143 immune-related LncRNAs. Kaplan-Meier analysis showed that C3 patients survived significantly worse than the other two clusters (P < 0.0001). A comparison of TCGA miRNA, mRNA cluster with immune cluster showed the independence and robustness of immune clusters (HR = 2.02 and P = 2.12 × 10-8 ). The GSEA and CIBERSORT analysis showed high enrichment of poorly activated T-cells in C3 patients. To define LncRNA immune prognostic signature, we randomly divided the TCGA sample into discovery and validation sets. By utilising multivariate Cox regression analysis, we identified and validated a seven LncRNA immune prognostic signature score (LIPS score) (HR = 1.43 and P = 2.73 × 10-6 ) in KIRC. Comparison of LIPS score with all the clinical factors validated its independence and superiority in KIRC prognosis. In summary, we identified LncRNAs associated with the immune system and showed the presence of prognostic subtypes of KIRC patients based on immune-related LncRNA expression. We also identified a novel immune LncRNA based gene-signature for KIRC patients' prognostication.
TL;DR: This review discusses how molecular changes during adipose tissue dysregulation can result in oxidative stress and subsequent DNA damage, which represents one of the many critical steps connecting obesity and cancer since oxidative DNA lesions canresult in cancer‐associated genetic instability.
Abstract: Obesity, defined as a state of positive energy balance with a body mass index exceeding 30 kg/m2 in adults and 95th percentile in children, is an increasing global concern. Approximately one-third of the world's population is overweight or obese, and in the United States alone, obesity affects one in six children. Meta-analysis studies suggest that obesity increases the likelihood of developing several types of cancer, and with poorer outcomes, especially in children. The contribution of obesity to cancer risk requires a better understanding of the association between obesity-induced metabolic changes and its impact on genomic instability, which is a major driving force of tumorigenesis. In this review, we discuss how molecular changes during adipose tissue dysregulation can result in oxidative stress and subsequent DNA damage. This represents one of the many critical steps connecting obesity and cancer since oxidative DNA lesions can result in cancer-associated genetic instability. In addition, the by-products of the oxidative degradation of lipids (e.g., malondialdehyde, 4-hydroxynonenal, and acrolein), and gut microbiota-mediated secondary bile acid metabolites (e.g., deoxycholic acid and lithocholic acid), can function as genotoxic agents and tumor promoters. We also discuss how obesity can impact DNA repair efficiency, potentially contributing to cancer initiation and progression. Finally, we outline obesity-related epigenetic changes and identify the gaps in knowledge to be addressed for the development of better therapeutic strategies for the prevention and treatment of obesity-related cancers.
TL;DR: The results showed that the HOXC8‐MGP axis played an important role in the tumorigenesis of TNBC and might be a promising therapeutic target for TNBC treatment.
Abstract: Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype which accounts for 15%-20% of all breast cancer cases. The management of TNBC has remained a challenge due to its lack of targeted therapy. Previously, we reported that homeobox C8 (HOXC8) was involved in metastasis and migration of breast cancer cells. By chromatin immunoprecipitation and luciferase assays, we found that HOXC8 functioned as a transcription factor to activate the transcription of matrix Gla protein (MGP) gene, leading to an increase in the proliferation, anchorage-independent growth, and migration of TNBC cells. We further demonstrated that MGP expression promoted the epithelial-mesenchymal transition (EMT) process of TNBC cells, but not the other subtypes of breast cancer, suggesting that MGP induced EMT to promote proliferation and migration of TNBC cells. Moreover, we found that MGP was upregulated in clinical breast specimens compared to normal breast tissues and high MGP expression was statistically associated with poor, relapse-free survival for TNBC patients, indicating that MGP is probably a novel biomarker or therapeutic target for TNBC patients. Together, our results showed that the HOXC8-MGP axis played an important role in the tumorigenesis of TNBC and might be a promising therapeutic target for TNBC treatment.
TL;DR: It is shown that gemcitabine treatment induces EMT‐like changes that sustain invasion and chemoresistance in PC cells, and that inhibition of ERK1/2 phosphorylation or ZEB‐1 expression resulted in a decrease in Chemoresistance.
Abstract: Growing body of evidence suggests that epithelial-mesenchymal transition (EMT) is a critical process in tumor progression and chemoresistance in pancreatic cancer (PC). The aim of this study was to analyze the role of EMT-like changes in acquisition of resistance to gemcitabine in pancreatic cells of the mesenchymal or epithelial phenotype. Therefore, chemoresistant BxPC-3, Capan-2, Panc-1, and MiaPaca-2 cells were selected by chronic exposure to increasing concentrations of gemcitabine. We show that gemcitabine-resistant Panc-1 and MiaPaca-2 cells of mesenchymal-like phenotype undergo further EMT-like molecular changes mediated by ERK-ZEB-1 pathway, and that inhibition of ERK1/2 phosphorylation or ZEB-1 expression resulted in a decrease in chemoresistance. Conversely, gemcitabine-resistant BxPC-3 and Capan-2 cells of epithelial-like phenotype did not show such typical EMT-like molecular changes although the expression of the tight junction marker occludin could be found decreased. In pancreatic cancer patients, high ZEB-1 expression was associated with tumor invasion and tumor budding. In addition, tumor budding was essentially observed in patients treated with neoadjuvant chemotherapy. These findings support the notion that gemcitabine treatment induces EMT-like changes that sustain invasion and chemoresistance in PC cells.
TL;DR: It is shown that miR‐19a‐3p enhances the oncogenesis of ovarian cancer through inhibition of IGFBP‐3 expression, and which can be inhibited by NF‐κB, suggesting an NF‐kappaB/miR‐ 19a‐ 3p/IGF BP‐3 pathway in the onCogenesis of ovarian cancer, which expands the understanding of ovariancancer.
Abstract: Ovarian cancer is the most lethal gynecologic malignancy due to the lack of symptoms until advanced stages, and new diagnosis and treatment strategy is in urgent need. In this study, we found higher expression of miR-19a-3p in ovarian cancer tissues compared with that in the adjacent normal tissues. By chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA) analysis, we showed that nuclear factor-kappaB (NF-κB) binds to the promoter of miR-19a-3p, leading to reduced expression in ovarian cancer cells. Further study indicated that miR-19a-3p inhibits the expression of insulin-like growth factor binding protein-3 (IGFBP-3), resulting in enhanced growth and migration of ovarian cancer cells in vitro and tumor growth in vivo. These results showed that miR-19a-3p enhances the oncogenesis of ovarian cancer through inhibition of IGFBP-3 expression, and which can be inhibited by NF-κB, suggesting an NF-κB/miR-19a-3p/IGFBP-3 pathway in the oncogenesis of ovarian cancer, which expands our understanding of ovarian cancer and they may contribute to the development of new diagnosis and treatment of ovarian cancer.
TL;DR: It is shown that RAGE has direct association with K‐Ras following HMGB1 exposure in colorectal cancer (CRC) cells, and it is revealed that both of RAGE and Yap1 expression could predicted unfavorable prognosis in CRC patients.
Abstract: HMGB1-RAGE signaling plays an integral role in inflammation-driven carcinogenesis. In the present study, we showed that RAGE has direct association with K-Ras following HMGB1 exposure in colorectal cancer (CRC) cells. Immunofluorescence analysis revealed a significant co-localization between RAGE and K-Ras in HMGB1-exposed CRC cells. Moreover, we uncovered that HMGB1-mediated RAGE activation led to Yap1 accumulation in a Ras-dependent mechanism in CRC cells. HMGB1 activated the expression of Yap1 downstream stemness marker proteins CD44 and Sox2 in RAGE- and Ras-dependent manners. Furthermore, HMGB1 exposure led to the proliferation of CRC cells and the expansion of CRC stem cells. RAGE, Yap1 and CD44 were overexpressed in CRC specimens. Linear regression analysis revealed that the expression of RAGE was positively correlated with Yap1 in clinical CRC specimens. Both of RAGE and Yap1 expression were correlated with advanced histological grades, lymph node metastasis and TNM stages. Finally, we revealed that both of RAGE and Yap1 expression could predicted unfavorable prognosis in CRC patients. These findings implicated that HMGB1-RAGE signaling may promote Yap1 activation and CRC progression, shedding new light on the mechanisms underlying inflammation-driven CRC development.
TL;DR: It is found that miR‐20a was significantly downregulated under hypoxia in colon cancer cells, and overexpression of miR-20a alleviated hypoxIA‐induced autophagy, suggesting that hyp oxia‐mediated autophagic flux was regulated by miR•20a/ATG5/FI200 signaling pathway in CRC.
Abstract: Autophagy is a highly conserved lysosome-mediated protective cellular process in which cytosolic components, including damaged organelles and long-lived proteins, are cleared. Many studies have shown that autophagy was upregulated in hypoxic regions. However, the precise molecular mechanism of hypoxia-induced autophagy in colorectal cancer (CRC) is still elusive. In this study, we found that miR-20a was significantly downregulated under hypoxia in colon cancer cells, and overexpression of miR-20a alleviated hypoxia-induced autophagy. Moreover, miR-20a inhibits the hypoxia-induced autophagic flux by targeting multiple key regulators of autophagy, including ATG5 and FIP200. Furthermore, by dual-luciferase assay we demonstrated that miR-20a directly targeted the 3'-untranslated region of ATG5 and FIP200, regulating their messenger RNA and protein levels. In addition, reintroduction of exogenous ATG5 or FIP200 partially reversed miR-20a-mediated autophagy inhibition under hypoxia. A negative correlation between miR-20a and its target genes is observed in the hypoxic region of colon cancer tissues. Taken together, our findings suggest that hypoxia-mediated autophagy was regulated by miR-20a/ATG5/FI200 signaling pathway in CRC. miR-20a-mediated autophagy defect that might play an important role in hypoxia-induced autophagy during colorectal tumorigenesis.
TL;DR: It is shown that farnesylated DNAJA1 is a crucial chaperone in maintaining mutant p53 stabilization and targeting farnesyated DNA JA1 by atorvastatin will be critical for inhibiting p53 mutant cancer.
Abstract: Recent studies have indicated that using statins to inhibit the mevalonate pathway induces mutant p53 degradation by impairing the interaction of mutant p53 with DnaJ subfamily A member 1 (DNAJA1). However, the role of the C-terminus of DNAJA1 with a CAAX box for farnesylation in the binding, folding, and translocation of client proteins such as mutant p53 is not known. In the present study, we used a genetically engineered mouse model of pancreatic carcinoma and showed that atorvastatin significantly increased animal survival and inhibited pancreatic carcinogenesis. There was a dramatic decrease in mutant p53 protein accumulation in the pancreatic acini, pancreas intraepithelial neoplasia lesions, and adenocarcinoma. Supplementation with farnesyl pyrophosphate, a substrate for protein farnesylation, rescued atorvastatin-induced mutant p53 degradation in pancreatic cancer cells. Tipifarnib, a farnesyltransferase inhibitor, mirrored atorvastatin's effects on mutant p53, degraded mutant p53 in a dose-dependent manner, and converted farnesylated DNAJA1 into unfarnesylated DNAJA1. Farnesyltransferase gene knockdown also significantly promoted mutant p53 degradation. Coimmunoprecipitation either by an anti-DNAJA1 or p53 antibody confirmed the direct interaction of mutant p53 and DNAJA1 and higher doses of atorvastatin treatments converted more farnesylated DNAJA1 into unfarnesylated DNAJA1 with much less mutant p53 pulled down by DNAJA1. Strikingly, C394S mutant DNAJA1, in which the cysteine of the CAAX box was mutated to serine, was no longer able to be farnesylated and lost the ability to maintain mutant p53 stabilization. Our results show that farnesylated DNAJA1 is a crucial chaperone in maintaining mutant p53 stabilization and targeting farnesylated DNAJA1 by atorvastatin will be critical for inhibiting p53 mutant cancer.