Browsing by Subject "EGFR"
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- PublicationOpen AccessClinicopathological features and genomic analysis of bronchiolar adenoma(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2023) Bo, Jiaqi; Chen, Xue; Zhang, TingTing; Zhu, Xuyou; Zhang, Long; Liu, Yuting; Zhang, Haoyang; Wu, Caixia; Mou, Shunyan; Yi, Xianghua; Rui, Weiwei; Zeng, YuBackground. Bronchiolar adenoma (BA) is a rare tumor of the bronchioles with a double-layer structure, including the basal cell layer and the superficial cell layer, and it has a good prognosis. However, the concept of a putative variant of BA has been proposed in the recent literature. Methods. Data on 17 cases of BA were collected from our center. The clinical data, morphology, immunophenotype, and molecular changes were retrospectively analyzed. We also collected the molecular changes in BA reported in the previous literature and summarized the putative driver mutations of BA. Results. Out of 17 BAs, 13 were classic cases with a double-layer structure, including 9 proximal-type and 4 distal-type BAs. Of note, we also identified 3 cases that lacked a continuous basal cell layer, including 2 cases of mixed-type BA with monolayered lesions (basal cells were undetected in some areas) and 1 case of a monolayered BA-like lesion (basal cells were completely undetected). The immunohistochemical findings of monolayer cell lesions were closer to those of minimally invasive adenocarcinoma. We also found one case in which BA transformed into invasive adenocarcinoma accompanied by mutations in the TP53, JAK2, NF1 and RB1 genes. Combined with the previous literature, the most common putative driver gene mutations in 62 BA lesions were EGFR (25/62; 41.0%) and BRAF (21/62; 34.4%). Conclusion. Typical BA has a double-layer cell structure; however, there is also a putative variant of BA, which has a monolayer cell structure and lacks the basal cell layer. Transformation from BA into invasive adenocarcinoma is unusual but can occur
- PublicationOpen AccessEGFR, KRAS, BRAF, and PIK3CA characterization in squamous cell anal cancer(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2014) Martin, Vittoria; Zanellato, Elena; Franzetti-Pellanda, Alessandra; Molinari, Francesca; Movilia, Alessandra; Paganotti, Alessia; Deantonio, Letizia; De Dosso, Sara; Assi, Agnese; Crippa, Stefano; Boldorini, Renzo; Mazzucchelli, Luca; Saletti, Piercarlo; Frattini, MiloBackground: Combined chemoradiation therapy is the gold standard in the treatment of squamous cell anal cancer (SCAC). However, even if the response rate is very high, many patients eventually relapse or experience a recurrence, thus requiring an invasive surgical procedure that has severe side effects. Most SCAC tumors overexpress epidermal growth factor receptor (EGFR); therefore, it is reasonable to consider anti-EGFR drugs as a new treatment option, as demonstrated by anecdotal reports. Promising results obtained in other solid tumors, both squamous and non-squamous, have revealed that an increase in the EGFR gene copy number may predict the efficacy of anti-EGFR therapies, while the presence of mutations in downstream members of the EGFR pathway may confer resistance. These markers have been only sporadically considered in SCAC. Methods: We investigated the status of the EGFR gene using FISH and examined KRAS, BRAF, and PIK3CA hot-spots mutations using sequencing analysis in a cohort of 84 patients affected by SCAC. Results: Twenty-eight patients (34%) showed an increase in EGFR gene copy number due to amplification (4%) or to polysomy (30%). KRAS and PIK3CA gene mutations were found in 4 (5%) and 13 patients (16%), respectively. No mutations were found in the BRAF gene. Conclusions: The characterization of the EGFR pathway may help in identifying different subgroups of SCAC that have specific molecular features, which may have implications in what targeted therapies are used to treat each patient. Histol Histopathol 29, 513-521 (2014)
- PublicationOpen AccessEvidence for different expression profiles for c-Met, EGFR, PTEN and the mTOR pathway in low and high grade endometrial carcinomas in a cohort of consecutive women. Occurrence of PIK3CA and K-Ras mutations and microsatellite instability(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2014) Thoury, Anne; Descatoire, Véronique; Kotelevets, Larissa; Kannengiesser, Caroline; Bertrand, Guylène; Theou-Anton, Nathalie; Frey, Caroline; Genestie, Catherine; Raymond, Eric; Chastre, Eric; Lehy, Thérèse; Walker, FrancineMolecular and genetic investigations in endometrial carcinogenesis may have prognostic and therapeutic implications. We studied the expression of EGFR, c-Met, PTEN and the mTOR signalling pathway (phospho-AKT/phospho-mTOR/phospho-RPS6) in 69 consecutive tumours and 16 tissue microarrays. We also analysed PIK3CA, K-Ras mutations and microsatellite instability (MSI). We distinguished two groups: group 1 (grade 1 and 2 endometrioid cancers) and group 2 (grade 3 endometrioid and type II clear and serous cell cancers). We hypothesised that these histological groups might have different features. We found that a) survival was higher in group 1 with less aggressive tumours (P<0.03); b) EGFR (P=0.01), PTEN and the AKT/mTOR/RPS6 signalling pathway were increased in group 1 versus group 2 (P=0.05 for phospho-mTOR); c) conversely, cMet was higher (P<0.03) in group 2 than in group 1; d) In group 1, EGFR was correlated with c-Met, phosphomTOR, phospho-RPS6 and the global activity of the phospho-AKT/phospho-mTOR/phospho-RPS6 pathway. In group 2, EGFR was correlated only with the phosphoAKT/phospho-mTOR/phospho-RPS6 pathway, whereas c-Met was correlated with PTEN; e) survival was higher for tumours with more than 50% PTEN-positive cells; f) K-RAS and PIK3CA mutations occurred in 10-12% of the available tumours and MSI in 40.4%, with a loss of MLH1 and PMS2 expression. Our results for endometrial cancers provide the first evidence for a difference in status between groups 1 and 2. The patients may benefit from different targeted treatments, antiEGFR agents and rapamycin derivatives (anti-mTOR) for group 1 and an anti c-MET/ligand complex for group 2.
- PublicationOpen AccessInhibition of ubiquitin specific peptidase 8 is effective against 5-fluorouracil resistance in colon cancer via suppressing EGFR and EGFR-mediated signaling pathways(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2024) Xi, Changlei; Gong, Zhilin; Ye, Hui; Cao, Longlei; Yu, JieBackground. The identification of a sensitizing strategy to overcome 5-fluorouracil (5-FU) therapeutic resistance is needed in colon cancer. Recent studies highlight the oncogenic role of ubiquitin specific peptidase 8 (USP8) in many cancers. In line with these efforts, this work investigated the therapeutic potential of targeting USP8 in colon cancer. Methods. Immunohistochemistry was performed to determine USP8 expression level in colon cancer tissues and their adjacent normal tissues. Gain-of-function analysis via plasmid overexpression and loss-of-function analysis via siRNA knockdown were applied on cellular assays. The combinatory effects of USP8 inhibitor and cisplatin were determined using a colon xenograft mouse model. Immunoblotting was performed to investigate the molecular mechanism of USP8 inhibition in colon cancer cells. Results. Compared to normal counterparts, we showed that USP8 protein level was significantly higher in colon cancer tissues and cells. In addition, USP8 expression was not affected by prolonged exposure of colon cancer cells to 5-FU. USP8 was important for colon cancer cell growth and survival but not migration as assessed by loss-of-function and gain-of-function approaches. Pharmacological inhibition of USP8 using USP8 inhibitor is active against both sensitive and 5-FUresistant colon cancer cells. Of note, USP8 inhibitor significantly inhibited colon cancer formation and growth, and augmented in vivo efficacy of 5-FU without causing toxicity in mice. Mechanistic studies showed that USP8 inhibitor acted on colon cancer cells through suppressing EGFR and EGFR-mediated signalling pathways. Conclusions. Our work is the first to reveal the essential role of USP8 in colon cancer via EGFR oncogenic signalling pathways. Our findings provide a proof-of-concept that USP8 inhibitors are promising candidates to overcome 5-FU resistance in colon cancer
- PublicationOpen AccessModulation of EGFR gene transcription by secondary structures, a polymorphic repetitive sequence and mutations - a link between genetics and epigenetics(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2000) Gebhardt, F.; Bürger, H.; Brandt, B.The epidermal growth factor receptor (EGFR) plays a crucial role in growth, differentiation and motility of normal as well as tumor cells. The transduction of extracellular signals to the cytoplasm via the receptor not only depends on ligand binding, but is also determined by the receptor density on the cell surface. Therefore , in terms of cancer diagnosis and therapeutic approaches targeting EGFR it is decisive to know how the expression level of EGFR is controlled. We found that transcription activity declines with increasing numbers of CA dinucleotides of a highly polymorphic CA repeat in the first intron epidermal growth factor receptor gene. In vivo data from cultured cell lines support these findings, although other regulation mechanisms can compensate this effect. In addition, we showed that RNA elongation terminates at a site closely downstream of the simple sequence repeat (SSR) and that there are two separate major transcription start sites. Model calculations for the helical DNA conformation revealed a high bend ability in the EGFR polymorphic region, es pecially if the CA stretch is extended. These data suggest that the CA-SSR can act like a joint bringing the promoter in proximity to a putative repressor protein bound downstream of the CASSR. The data suggest that this polymorphism is a marker for cancer linking genetic and epigenetic risk. Furthermore in breast cancer, heterozygous tumours with short CA-SSR showed an elevated EGFR-expression in contrast to tumours with longer CA-SSR. Tumours with loss of heterozygosity in intron 1 of egfr revealed an increased EGFR expression if the longer allele was lost. Moreover, deceased egfr gene dosages were significantly correlated to poor prognosis in breast cancer.
- PublicationOpen AccessTau, downstream of IDH mut, inhibits the EGFR/NF-kB/TAZ mesenchymal axis, normalizing the vasculature and impairing glioma aggressiveness(American Association for the Advancement of Science, 2021-01-22) Gargini, Ricardo; Segura Collar, Berta; Herránz, Beatriz; García Escudero, Vega; Romero Bravo, Andrés; Núñez, Felipe J.; García Pérez, Daniel; Gutiérrez Guamán, Jacqueline; Ayuso Sacido, Ángel; Seoane, Joan; Pérez Núñez, Ángel; Sepúlveda Sánchez, Juan M.; Hernández Laín, Aurelio; Castro, María G.; García Escudero, Ramón; Ávila, Jesús; Sánchez Gómez, Pilar; Farmacología; Facultades de la UMU::Facultad de MedicinaMutant IDH1/2 gliomas represent a more indolent form of cancer. However, how this group of tumors progress, in a microenvironment-dependent manner, is still a pending question. Here we describe that the expression of Tau, a gene classically associated with neurodegenerative diseases, is epigenetically controlled by the balance between wild-type and mutant IDH1/2 in gliomas. Moreover, Tau is almost absent from tumors with EGFR mutations, whereas its expression is inversely correlated with overall survival in gliomas carrying wild-type or amplified EGFR. We demonstrate that the overexpression of Tau, through the stabilization of microtubules, impairs the mesenchymal/pericyte transformation of EGFRamp/wt glioma cells through the blockade of the EGFR-NFκB-TAZ axis. However, mutant EGFR induces a constitutive activation of this pathway, which is no longer sensitive to Tau. By inhibiting the phenotypic plasticity of EGFRamp/wt glioma cells, Tau protein inhibits angiogenesis and favors vascular normalization, decreasing tumor aggressiveness.