Epidermal Growth Factor Receptor Axis Research Articles

Chitinase 3-like-1 (CHI3L1) in the pathogenesis of epidermal growth factor receptor mutant non-small cell lung cancer

Non-small cell lung cancer (NSCLC) accounts for 85 % of all lung cancers. In NSCLC, 10–20 % of Caucasian patients and 30–50 % of Asian patients have tumors with activating mutations in the Epidermal Growth Factor Receptor (EGFR). A high percentage of these patients exhibit favorable responses to treatment with tyrosine kinase inhibitors (TKI). Unfortunately, a majority of these patients develop therapeutic resistance with progression free survival lasting 9–18 months. The mechanisms that underlie the tumorigenic effects of EGFR and the ability of NSCLC to develop resistance to TKI therapies, however, are poorly understood. Here we demonstrate that CHI3L1 is produced by EGFR activation of normal epithelial cells, transformed epithelial cells with wild type EGFR and cells with cancer-associated, activating EGFR mutations. We also demonstrate that CHI3L1 auto-induces itself and feeds back to stimulate EGFR and its ligands via a STAT3-dependent mechanism(s). Highly specific antibodies against CHI3L1 (anti-CHI3L1/FRG) and TKI, individually and in combination, abrogated the effects of EGFR activation on CHI3L1 and the ability of CHI3L1 to stimulate the EGFR axis. Anti-CHI3L1 also interacted with osimertinib to reverse TKI therapeutic resistance and induce tumor cell death and inhibit pulmonary metastasis while stimulating tumor suppressor genes including KEAP1. CHI3L1 is a downstream target of EGFR that feeds back to stimulate and activate the EGFR axis. Anti-CHI3L1 is an exciting potential therapeutic for EGFR mutant NSCLC, alone and in combination with osimertinib or other TKIs.

Structural insights into the role and targeting of EGFRvIII

The epidermal growth factor receptor (EGFR) is a well-known oncogenic driver in lung and other cancers. In glioblastoma multiforme (GBM), the EGFR deletion variant III (EGFRvIII) is frequently found alongside EGFR amplification. Agents targeting the EGFR axis have shown limited clinical benefits in GBM and the role of EGFRvIII in GBM is poorly understood. To shed light on the role of EGFRvIII and its potential as a therapeutic target, we determined X-ray crystal structures of a monomeric EGFRvIII extracellular region (ECR). The EGFRvIII ECR resembles the unliganded conformation of EGFR, including the orientation of the C-terminal region of domain II. Domain II is mostly disordered, but the ECR structure is compact. We selected a nanobody with preferential binding to EGFRvIII relative to EGFR and structurally defined an epitope on domain IV that is occluded in the unliganded intact EGFR. These findings suggest new avenues for EGFRvIII targeting in GBM.

Long noncoding RNA XIST promotes cell proliferation and migration in diabetic foot ulcers through the miR-126-3p/EGFR axis

BackgroundThe prevalence of diabetic foot ulcers (DFUs) has caused serious harm to human health. To date, a highly effective treatment is lacking. Long noncoding RNA X-inactive specific transcript (lncRNA XIST) has been the subject of mounting research studies, all of which have found that it serves as a protective factor against certain diseases; however, its function in DFUs is not entirely understood. This study was performed to determine the importance of the lncRNA XIST in the pathogenesis and biological function of DFUs.MethodsDiabetic ulcer skin from rats was analysed using haematoxylin-eosin (HE), Masson’s trichrome, and immunohistochemistry (IHC) staining. The differences in the expression of genes and proteins were examined with real-time quantitative polymerase chain reaction (RT–qPCR) and Western blotting. Next, the interaction was verified with a dual luciferase gene reporter assay. In addition, CCK-8, Transwell, and wound healing assays were used to assess the proliferation and migration of HaCaT cells.ResultsThe lncRNA XIST and epidermal growth factor receptor (EGFR) were downregulated, while microRNA-126-3p (miR-126-3p) was increased in diabetic ulcer rat skin tissues and high glucose-induced HaCaT cells. In addition, we found that the lncRNA XIST binds to miR-126-3p and that EGFR is directly targeted by miR‑126‑3p. Silencing XIST contributed to upregulated miR-126-3p expression, thus lowering EGFR levels and inhibiting the proliferative and migratory abilities of high glucose-treated HaCaT cells; however, the miR-126-3p inhibitor and overexpression of EGFR reversed this effect.ConclusionDecreased lncRNA XIST expression inhibits the proliferative and migratory abilities of high glucose-induced HaCaT cells by modulating the miR-126-3p/EGFR axis, causing delayed wound healing.

Retracted: Long Noncoding RNA HLA Complex Group 18 Improves the Cell Proliferation of Myocardial Fibroblasts by Regulating the Hsa-microRNA-133a/Epidermal Growth Factor Receptor Axis.

[This retracts the article DOI: 10.1155/2022/2668239.].

Circ_0001955 promotes the progression of non-small cell lung cancer via miR-769-5p/EGFR axis

ABSTRACT To elaborate on the role of circular RNA 0001955 (circ_0001955) on the proliferation and apoptosis of non-small cell lung cancer (NSCLC) cells and its underlying mechanism. Circ_0001955 expression in NSCLC was screened out through bioinformatics analysis based on GEO database. Circ_0001955, microRNA-769-5p (miR-769-5p), and epidermal growth factor receptor (EGFR) expression in NSCLC tissues and cell lines was examined using quantitative real-time PCR (qRT-PCR) and Western blot. Cell proliferation and apoptosis were examined using the CCK-8 method, BrdU experiment and flow cytometry analysis, respectively. Bioinformatics prediction, dual-luciferase reporter gene experiment and RNA immunoprecipitation (RIP) experiments were applied to validate the targeting relationship between miR-769-5p and circ_0001955 and the 3’ UTR of EGFR. Pearson’s correlation analysis was employed to validate the correlations among them. Circ_0001955 expression was up-regulated in NSCLC tissues and cell lines, and its overexpression was strongly associated with increased tumor TNM stage and lymph node metastasis. Circ_0001955 overexpression enhanced the proliferation and restrained the apoptosis in NSCLC cells, whereas knocking down circ_0001955 exerted the opposite effects. Circ_0001955 directly targeted miR-769-5p and negatively regulated its expression. EGFR, a target gene of miR-769-5p, could be indirectly and positively regulated by circ_0001955. Correlation analysis indicated that circ_0001955 was negatively correlated with miR-769-5p expression, while circ_0001955 was positively correlated with EGFR expression. Circ_0001955 facilitates the proliferation and represses the apoptosis of NSCLC cells by modulating miR-769-5p/EGFR axis.

Long Noncoding RNA HLA Complex Group 18 Improves the Cell Proliferation of Myocardial Fibroblasts by Regulating the Hsa-microRNA-133a/Epidermal Growth Factor Receptor Axis.

Hsa-microRNA (has-miR)-133a inactivates the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway and suppresses the cell proliferation of myocardial fibroblasts by downregulation of the epidermal growth factor receptor (EGFR) expression. Bioinformatics analysis exhibits extended noncoding RNA HLA complex group 18 (lncRNA-HCG18) binds to hsa-miR-133a. The purpose of the current experiment is to explore whether lncRNA-HCG18 adsorbed hsa-miR-133a through sponging, resulting in decreased inhibition of hsa-miR-133a on EGFR and ultimately promoting the proliferation of myocardial fibroblasts. To verify and study the correlation and mechanism between lncRNA-HCG18, hsa-miR-133a, and their target genes. Firstly, after overexpression/silencing of lncRNA-HCG18 in myocardial fibroblasts, the level of hsa-miR-133a expression was evaluated by quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and the EGFR, ERK1/2, and p-ERK1/2 expression levels were assessed by Western blotting to confirm that upregulation of EGFR and p-ERK1/2 protein levels by overexpression of lncRNA-HCG18, siRNA lncRNA-HCG18 (siHCG18) reduced the EGFR and p-ERK1/2 protein levels. Then, the luciferase reporter gene system was used to verify that lncRNA-HCG18 regulated EGFR expression by inhibiting the function of the hsa-miR-133a regulatory target gene. Then, a RAP assay was used to confirm that lncRNA-HCG18 interacted with hsa-miR-133a. Finally, the analysis of CCK-8 results indicated that the cell proliferation of myocardial fibroblasts was significantly reduced by siHCG18 while reversed by overexpression of lncRNA-HCG18. Thus, lncRNA-HCG18 inhibited cell viability of cardiac fibroblasts via the hsa-miR-133a/EGFR axis, which was regarded as a regulator of cell proliferation of cardiac fibroblasts in cardiovascular diseases.

Tumor profiling of KRAS, BRAF, and NRAS gene mutations in patients with colorectal cancer: A Lebanese major center cohort study

BackgroundIn the era of precision medicine, treatment schemes for advanced Colorectal (CRC) disease include monoclonal antibodies which block the epidermal growth factor receptor (EGFR) implicated in tumor proliferation, invasion, migration and neovascularization. Resistance to these agents has been correlated with activating downstream mutations in KRAS, BRAF and NRAS genes, among others, leading to constitutive activation of the EGFR axis bypassing EGFR blockade. The assessment of tumor RASandBRAFmutational status has thus become standard clinical practice. While multiple investigations reported roughly mutations rates of 40% in KRAS, 7% in NRAS and 5–15 % in BRAF, numbers vary across different populations with limited data specifically from the Middle East. MethodsThis is a retrospective observational Laboratory information system (LIS) chart review of all the patients with pathologically confirmed colorectal carcinoma (CRC) or metastatic CRC who underwent KRAS, NRAS and/or BRAF mutational analysis testing at the Molecular Diagnostics Laboratory of the American University of Beirut Medical Center (AUBMC) from January 2012 to December 2018, inclusive. Data retrieved included the results of mutation testing performed for KRAS, NRAS and BRAF genes, the age, gender, and tumor location for each patient. Analysis of the mutations was performed using polymerase chain reaction (PCR) hybridization StripAssay® (ViennaLab, Vienna, Austria). Results130 (47.6%) out of 273 histologically confirmed CRC cases, had positive KRAS mutations, namely in codons 12 (82%), 13 (17%), 146 (1.5%), 117 (0.75%), or 61 (0.75%). Two patients had two concomitant mutations: 12 + 12 (different mutations) and 12 + 146. Of 203 CRC cases tested for NRAS mutations, 16 (7.8%) were found to be positive for a mutation in codon 12 (37.5%), 61 (37.5%), or 13 (12.5%). Two patients had two concomitant mutations: 12 + 13 and 59 + 61. Of 172 CRC cases tested for BRAF mutations, 2 (1.2 %) were positive for the V600E -. ConclusionThis retrospective study is the first to report the frequencies of KRAS, NRAS and BRAF gene mutations in a Lebanese CRC cohort diagnosed and managed at a tertiary care center. The frequencies of the studied somatic gene mutations were similar to previously reported cohorts in other populations however the rate of BRAF mutation was lower in this cohort than expected.

Circular RNA ZNF609 promotes laryngeal squamous cell carcinoma progression by upregulating epidermal growth factor receptor via sponging microRNA-134-5p

ABSTRACT Emerging evidence has revealed that aberrantly expressed circular RNAs (circRNAs) play vital roles in tumorigenesis and progression of diverse human malignancies. CircZNF609 was found to be involved in hepatocellular carcinoma, but the role and underlying mechanism of circZNF609 in laryngeal squamous cell carcinoma (LSCC) remain unclear. This study aimed to explore the molecular mechanism of circZNF609 in LSCC. qRT-qPCR was performed to detect the expression of circZNF609 and microRNA-134-5p (miR-134-5p) in LSCC. Colony formation assay, CCK-8 assay, BrdU incorporation assay, clone formation assay, transwell invasion assay and Western blot analysis were performed to evaluate LSCC cell proliferation, as well as the expression of proliferating cell nuclear antigen (PCNA) and MMP-2. Luciferase reporter assay, target gene prediction and screening were used to validate downstream target genes of circZNF609 and miR-134-5p. EGFR expression was detected by Western blot analysis and RT-qPCR. Nude mice were used to detect tumor changes. CircZNF609 was upregulated in LSCC and associated with poor survival of LSCC patients. Knockdown of circZNF609 inhibited LSCC proliferation, invasion and the expression of PCNA and matrix matalloproteinases-2 (MMP-2). CircZNF609 can regulate miR-134-5p to upregulate epidermal growth factor receptor (EGFR). In addition, knockdown of EGFR or overexpression of miR-134-5p could reverse the tumor-promoting effects of circZNF609 in LSCC. In LSCC tissues, circZNF609 was negatively correlated with miR-134-5p and positively correlated with EGFR. CircZNF609 promotes the progression of LSCC via the miR-134-5p/EGFR axis, which might be the therapeutic target of LSCC.

Upregulated circ_0002141 facilitates oral squamous cell carcinoma progression via the miR-1231/EGFR axis.

The dysregulation of circular RNAs (circRNAs) is implicated in the progression of various cancers. This study was aimed at expounding the role and mechanism of hsa_circ_0002141 in the OSCC progression. Circ_0002141 expression was examined in 52 pairs of OSCC tissues and matched adjacent tissue samples by quantitative real-time polymerase chain reaction (qRT-PCR) assay. After circ_0002141 was overexpressed or knocked down in OSCC cell lines, cell counting kit-8 (CCK-8) assay, Transwell assay, flow cytometry, and Western blotting were conducted to detect the changes in the growth, migration, invasion and apoptosis of OSCC cells. Western blot assay, qRT-PCR and dual-luciferase reporter assay were performed to clarify the interplay among circ_0002141, miR-1231, and epidermal growth factor receptor (EGFR). Circ_0002141 expression was significantly upregulated in OSCC tissues and cell lines. Circ_0002141 overexpression markedly promoted the proliferation, migration, and invasion of OSCC cells whereas reduced the apoptotic of OSCC cells. Also, circ_0002141knockdown suppressed the malignant characteristics of OSCC cells. EGFR was validated as the target of miR-1231. Besides, circ_0002141 could sponge miR-1231 and upregulate EGFR expression in OSCC cells. Circ_0002141/miR-1231/EGFR axis is involved in the progression of OSCC.

RNA N6-methyladenosine modulates endothelial atherogenic responses to disturbed flow in mice.

Atherosclerosis preferentially occurs in atheroprone vasculature where human umbilical vein endothelial cells are exposed to disturbed flow. Disturbed flow is associated with vascular inflammation and focal distribution. Recent studies have revealed the involvement of epigenetic regulation in atherosclerosis progression. N6-methyladenosine (m6A) is the most prevalent internal modification of eukaryotic mRNA, but its function in endothelial atherogenic progression remains unclear. Here, we show that m6A mediates the epidermal growth factor receptor (EGFR) signaling pathway during EC activation to regulate the atherosclerotic process. Oscillatory stress (OS) reduced the expression of methyltransferase like 3 (METTL3), the primary m6A methyltransferase. Through m6A sequencing and functional studies, we determined that m6A mediates the mRNA decay of the vascular pathophysiology gene EGFR which leads to EC dysfunction. m6A modification of the EGFR 3' untranslated regions (3'UTR) accelerated its mRNA degradation. Double mutation of the EGFR 3'UTR abolished METTL3-induced luciferase activity. Adenovirus-mediated METTL3 overexpression significantly reduced EGFR activation and endothelial dysfunction in the presence of OS. Furthermore, thrombospondin-1 (TSP-1), an EGFR ligand, was specifically expressed in atheroprone regions without being affected by METTL3. Inhibition of the TSP-1/EGFR axis by using shRNA and AG1478 significantly ameliorated atherogenesis. Overall, our study revealed that METTL3 alleviates endothelial atherogenic progression through m6A-dependent stabilization of EGFR mRNA, highlighting the important role of RNA transcriptomics in atherosclerosis regulation.

Long non-coding RNA HLA complex group 18 promotes gastric cancer progression by targeting microRNA-370-3p expression.

Our research was aimed at investigating the biological character of human leukocyte antigen complex group 18 (HCG18) on gastric cancer (GC) progression and its potential mechanisms. The expression characteristics and prognostic values of HCG18 in GC were evaluated through the GEPIA database and Kaplan-Meier plotter database. Quantitative real-time PCR and Western blot were used for quantification of messenger RNA expression, microRNA (miRNA) expression and protein expression. Cell proliferation, migration and invasion were detected by cell counting kit-8 assay, 5'-bromo-2'-deoxyuridine assay and Transwell assay, respectively. Dual-luciferase reporter gene assay and RNA immunoprecipitation assay were used for examination of the interactions among HCG18, miR-370-3p and epidermal growth factor receptor (EGFR) 3'UTR. HCG18 expression was up-regulated in GC tissues, and its high expression was closely associated with increased tumour size, advanced TNM stage, poor differentiation of tumour tissues and unfavourable prognosis of patients with GC. Additionally, HCG18 overexpression promoted the proliferation, migration and invasion of GC cells, and its knockdown suppressed the malignant phenotypes of GC cells. Furthermore, HCG18 served as a miRNA sponge to repress miR-370-3p and indirectly up-regulated EGFR expression in GC cells. HCG18 served as a tumour-promoting factor in GC progression by modulating the miR-370-3p/EGFR axis.

LncRNA PITPNA-AS1 stimulates cell proliferation and suppresses cell apoptosis in glioblastoma via targeting miR-223-3p/EGFR axis and activating PI3K/AKT signaling pathway

ABSTRACT Glioblastoma (GBM) is a kind of malignant primary brain tumor, which is difficult to cure. Continuous researches have underlined that long non-coding RNAs (lncRNAs) get widely involved in the occurrence and progression of tumors, and glioblastoma is included. In this paper, we identified lncRNA PITPNA antisense RNA 1 (PITPNA-AS1) and explored its in-depth regulatory mechanism in glioblastoma cells. Firstly, RT-qPCR examined that PITPNA-AS1 was highly expressed in glioblastoma. Then, PITPNA-AS1 role in glioblastoma was assessed via functional assays. The results demonstrated that depletion of PITPNA-AS1 inhibited the proliferation and promoted the apoptosis of glioblastoma cells. After confirming that PITPNA-AS1 mainly existed in cell cytoplasm, we conducted mechanism assays which disclosed that PITPNA-AS1 sequestered microRNA-223-3p (miR-223-3p) and modulated epidermal growth factor receptor (EGFR) expression, thereby participating in the activation of PI3K/AKT signaling pathway. Eventually, rescue assays validated PITPNA-AS1 sponged miR-223-3p to promote EGFR expression, thus activating PI3K/AKT signaling pathway to accelerate proliferation and inhibit apoptosis of GBM cells. Overall, PITPNA-AS1 played an oncogenic role in glioblastoma which might be developed as a potential biomarker for glioblastoma diagnosis and treatment in the future.

The epidermal growth factor receptor axis and kidney fibrosis.

The aim of this study was to summarize recent findings about the role of the epidermal growth factor receptor (EGFR) in acute kidney injury and in progression of chronic kidney injury. There is increasing evidence that EGFR activation occurs as a response to either ischemic or toxic kidney injury and EGFR signalling plays an important role in recovery of epithelial integrity. However, with incomplete recovery or in conditions predisposing to progressive glomerular and tubulointerstitial injury, aberrant persistent EGFR signalling is a causal mediator of progressive fibrotic injury. New studies have implicated activation of HIPPO/YAP signalling as a component of EGFR's actions in the kidney. There is also new evidence for sex disparities in kidney EGFR expression and activation after injury, with a male predominance that is mediated by androgens. There is increasing evidence for an important role for EGFR signalling in mediation of kidney injury, raising the possibility that interruption of the signalling cascade could limit progression of development of progressive kidney fibrosis.

Long non-coding RNA CASC9 promotes the progression and development of gastric cancer via regulating miR-370/EGFR axis

lncRNA cancer susceptibility 9 (CASC9) is a pivotal modulator in various cancers, such as colorectal cancer, breast cancer and esophageal cancer. However, its exact role in gastric cancer (GC) has not been systematically studied. Here, using a combination of molecular and cell biology approaches, we found that CASC9 also acts as a factor promoting the progression of GC. First, mRNA and protein expression levels were quantified by real-time quantitative reverse transcription PCR (qRT-PCR) and western blot, respectively. Second, CCK-8 assay, colony formation assay and cell cycle analysis were performed to compare the cell growth abilities when CASC9 was knocked down. Third, the proliferative cells were determined by labeling Edu and the regulatory effect of CASC9 on miR-370 was detected by RNA-protein pull-down and luciferase reporter assays. Finally, in vivo mice model was established to verify the role of CASC9 in promoting GC progression. Our results showed that CASC9 was up-regulated significantly in both GC tissues and cell lines. Conversely, CASC9 knockdown inhibited GC growth in vitro. Further analysis indicated that CASC9 directly targeted miR-370 and negatively regulated miR-370 expression in GC. Besides, EGFR (epidermal growth factor receptor) was identified as a direct target gene of miR-370. Taken together our results support a model in which CASC9 promotes GC progression through miR-370/EGFR/ERK/AKT pathway. Finally, in vivo CASC9 knockdown resulted in impaired GC growth. In sum, this study firstly demonstrates that lncRNA CASC9 acts as an oncogene through altering EGFR expression level via negatively regulating miR-370 expression.

Long non-coding RNA TRPM2-AS sponges microRNA-138-5p to activate epidermal growth factor receptor and PI3K/AKT signaling in non-small cell lung cancer.

BackgroundLong non-coding RNAs (lncRNAs) can play pivotal roles in tumor progression by acting as microRNA (miRNA) sponges. This study aimed to investigate the association of a novel lncRNA, TRPM2-AS, with the miR-138-5p/EGFR axis in the development of non-small cell lung cancer (NSCLC).MethodsSixty NSCLC tissues and paired adjacent non-tumor tissues were analyzed. The relative expression levels of TRPM2-AS, miR138-5p, and epidermal growth factor receptor (EGFR) and the interactions between them were analyzed. The NSCLC cell lines NCI-H1299 and A549 were transfected with TRPM2-AS shRNA/pcDNA, and miR-138-5p mimics. Cell proliferation, migration, invasion, and apoptosis were examined in response to different transfection conditions. Dual-luciferase reporter assay was performed to identify the target interactions between TRPM2-AS, miR-138-5p, and EGFR. A549 cells stably transfected with shRNA were injected into BALB/c null nude mice to establish a tumor xenograft model.ResultsTRPM2-AS was up-regulated in NSCLC tumors and cell lines. Cell proliferation, migration, and invasion were inhibited in NSCLC cells treated with sh-TRPM2-AS, while apoptosis was induced. The targeting of TRPM2-AS by miR138-5p and miR138-5p by EGFR were validated with dual-luciferase reporter assay. TRPM2-AS was found to be negatively correlated with miR138-5p but positively correlated with EGFR. PI3K/AKT/mTOR was activated by pcDNA-EGFR but inactivated by miR-138-5p mimics. In the tumor xenograft mouse model, sh-TRPM2-AS suppressed tumor formation, reduced the expression of EGFR and Ki67, and promoted tumor cell apoptosis.ConclusionsOur results suggested that TRPM2-AS can increase the levels of EGFR via sponging miR-138-3p; this promoted NSCLC cell proliferation, migration, and invasion in vitro, and exacerbated tumors in vivo. These findings highlight TRPM2-AS/miR-138-5p as a potential target for reducing drug resistance in patients with NSCLC.

Knockdown of Circ_0081143 Mitigates Hypoxia-Induced Migration, Invasion, and EMT in Gastric Cancer Cells Through the miR-497-5p/EGFR Axis.

Background: Gastric cancer is one of the most common malignancies. Circular RNAs (circRNAs) are emerging as new players in the cancer paradigm. In the present study, the authors aimed to further explore the role and mechanism of circ_0081143 in GC progression under hypoxia. Materials and Methods: The expression levels of circ_0081143, miR-497-5p, and EGFR (epidermal growth factor receptor) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell migration and invasion abilities were determined by Transwell assay. The levels of vimentin, N-cadherin, E-cadherin, and EGFR were evaluated using Western blot. Dual-luciferase reporter assay was performed to confirm the targeted correlation between miR-497-5p and circ_0081143 or EGFR. Results: These data indicated that circ_0081143 expression was increased in GC tissues and cells. The knockdown of circ_0081143 relieved hypoxia-induced GC cell migration, invasion, and epithelial/mesenchymal transition (EMT). Moreover, circ_0081143 regulated the abundance of miR-497-5p through sponging miR-497-5p. The alleviative effects of circ_0081143 knockdown on GC cell migration, invasion, and EMT under hypoxia were mediated by miR-497-5p. Furthermore, miR-497-5p directly targeted EGFR, and miR-497-5p overexpression ameliorated hypoxia-induced GC cell migration, invasion, and EMT by downregulating EGFR. In addition, circ_0081143 modulated EGFR expression via acting as a competing endogenous RNA (ceRNA) of miR-497-5p in hypoxia-induced GC cells. Conclusion: The present work suggested that circ_0081143 knockdown ameliorated hypoxia-induced migration, invasion, and EMT in GC cells at least partly by the miR-497-5p/EGFR axis, illuminating a novel molecular target for GC treatment.

CiRS-7 Promotes the Proliferation and Migration of Papillary Thyroid Cancer by Negatively Regulating the miR-7/Epidermal Growth Factor Receptor Axis.

Purpose The incidence of papillary thyroid cancer (PTC) is increasing, and traditional diagnostic methods are unsatisfactory. Therefore, identifying novel prognostic markers is very important. ciRS-7 has been found to play an important role in many cancers, but its role in PTC has not been reported. This study was performed to evaluate the biological role and mechanism of ciRS-7 in PTC. Material and Methods. The expression of ciRS-7 in PTC tissues and the matched adjacent tissues was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The PTC cell lines (TPC-1 and BCPAP) were used to evaluate the role of ciRS-7. ciRS-7-siRNA and overexpression plasmid were constructed and transfected into PTC cells. A CCK-8 assay and colony formation assay were performed to explore the effects of ciRS-7 on cell proliferation. Annexin V/PI staining and FACS detection were used to detect cell apoptosis. Wound healing assay was performed to detect cell migration. A transwell assay was conducted to explore the effects of ciRS-7 on invasion and migration. Western blotting was performed to evaluate protein expression. The luciferase reporter system was used to determine the underlying mechanism of miR-7. Result ciRS-7 was highly expressed in PTC tissues and cell lines compared with the corresponding controls. In vitro study showed that ciRS-7 silencing suppressed proliferation, migration, and invasion of TPC-1 and BCPAP. Mechanistically, the effects of ciRS-7 on invasion and migration may be related to epithelial-mesenchymal transition (EMT). ciRS-7 silencing could attenuate effects on PTC cells induced by miR-7 knockdown. Epidermal growth factor receptor (EGFR), which was demonstrated to be a target of miR-7, decreased significantly in ciRS-7-siRNA PTC cells. Overexpression of EGFR also attenuated effects of PTC cells induced by silencing ciRS-7. Conclusion ciRS-7 was significantly upregulated in PTC tissues, and it promoted the progression of PTC by regulating the miR-7/EGFR axis. ciRS-7 is a promising prognostic biomarker and therapeutic target in PTC.

Targeted therapy and drug resistance in triple-negative breast cancer: the EGFR axis.

Targeting of estrogen receptor is commonly used as a first-line treatment for hormone-positive breast cancer patients, and is considered as a keystone of systemic cancer therapy. Likewise, HER2-targeted therapy significantly improved the survival of HER2-positive breast cancer patients, indicating that targeted therapy is a powerful therapeutic strategy for breast cancer. However, for triple-negative breast cancer (TNBC), an aggressive breast cancer subtype, there are no clinically approved targeted therapies, and thus, an urgent need to identify potent, highly effective therapeutic targets. In this mini-review, we describe general strategies to inhibit tumor growth by targeted therapies and briefly discuss emerging resistance mechanisms. Particularly, we focus on therapeutic targets for TNBC and discuss combination therapies targeting the epidermal growth factor receptor (EGFR) and associated resistance mechanisms.

Silencing of KCNK15-AS1 inhibits lung cancer cell proliferation via upregulation of miR-202 and miR-370.

Lung cancer is the most common cause of cancer-associated mortality globally. Long non-coding RNAs (lncRNAs) are transcripts with a length of >200 nucleotides, which are not translated into proteins. Growing evidence has indicated that certain lncRNAs are associated with various biological processes in cancer. However, the functions of KCNK15 and WISP2 antisense RNA 1 (KCNK15-AS1) in lung cancer carcinogenesis and progression have remained elusive. The present study indicated that KCNK15-AS1 was overexpressed in lung adenocarcinoma tissues compared with paracancerous normal tissues, and the high expression of KCNK15-AS1 was significantly associated with poor prognosis compared with the patients with low expression (P<0.001). Furthermore, the knockdown of KCNK15-AS1 was performed in A549 and H460 lung cancer cells with small interfering RNA, resulting in a significant inhibition of the proliferation, a decrease in the mRNA and protein expression of cyclin D1 (CCND1) and epidermal growth factor receptor (EGFR), in addition to the phosphorylation of protein kinase B, with a concomitant increase in the expression of microRNA (miR)-202 and miR-370 compared with negative control group. Rescue experiments demonstrated that the inhibition of miR-202 or miR-370 partially recovered the EGFR and CCND1 expression and the proliferation rates, which were reduced by KCNK15-AS1 silencing. In conclusion, these results suggested that KCNK15-AS1 functions as an oncogene via regulating the miR-202/miR-370/EGFR axis in lung cancer and may provide a potential target for lung cancer treatment.

Genetic mapping of pancreatic cancer by targeted next-generation sequencing in a cohort of patients managed with nab-paclitaxel-based chemotherapy or agents targeting the EGFR axis: a retrospective analysis of the Hellenic Cooperative Oncology Group (HeCOG)

Pancreatic cancer is one of the most fatal malignancies ranking fourth among the leading causes of cancer death with diagnosis at late stages carrying a dismal prognosis. The aim of our retrospective study was to describe the nature and the incidence of gene mutations and genomic instability in advanced pancreatic adenocarcinomas of a Greek patient population fully annotated with clinicopathological data. We used a targeted next-generation sequencing (NGS) panel encompassing genes commonly mutated in pancreatic tumours in a patient population managed with either nab-paclitaxel regimens or targeted compounds modulating the epidermal growth factor receptor (EGFR)/AKT/mTOR axis. We identified KRAS, TP53, SMAD4 and CDKN2A as being the most prevalent mutations in the study population with the exception of an intriguingly lower incidence regarding KRAS mutants. Homologous recombination gene mutations were found to be mutually exclusive with CDKN2A mutations. The coexistence of both KRAS and TP53 mutation seems to adversely affect the outcome of the patients whether treated with targeted therapy against EGFR/Akt/mTOR axis or cytotoxic drugs. The poor prognosis observed, correlated to late presentation, specific molecular mutations and to high mutational load warrant prospective validating studies and research into the mechanistic pathophysiology of pancreatic tumours for more effective therapeutic targeting.