Quantitative determination of nuclear and cytoplasmic epidermal growth factor receptor expression in oropharyngeal squamous cell cancer by using automated quantitative analysis

LRG1 and SDR16C5 protein expressions differ according to HPV status in oropharyngeal squamous cell carcinoma

The increasing incidence of oropharyngeal squamous cell carcinoma (OPSCC) is primarily due to human papillomavirus, and understanding the tumor biology caused by the virus is crucial. Our goal was to investigate the proteins present in the serum of patients with OPSCC, which were not previously studied in OPSCC tissue. We examined the difference in expression of these proteins between HPV-positive and -negative tumors and their correlation with clinicopathological parameters and patient survival. The study included 157 formalin-fixed, paraffin-embedded tissue samples and clinicopathological data. Based on the protein levels in the sera of OPSCC patients, we selected 12 proteins and studied their expression in HPV-negative and HPV-positive OPSCC cell lines. LRG1, SDR16C5, PIP4K2C and MVD proteins were selected for immunohistochemical analysis in HPV-positive and -negative OPSCC tissue samples. These protein´s expression levels were compared with clinicopathological parameters and patient survival to investigate their clinical relevance. LRG1 expression was strong in HPV-negative whereas SDR16C5 expression was strong in HPV-positive tumors. Correlation was observed between LRG1, SDR16C5, and PIP4K2C expression and patient survival. High expression of PIP4K2C was found to be an independent prognostic factor for overall survival and expression correlated with HPV-positive tumor status. The data suggest the possible role of LRG1, SDR16C5 and PIP4K2C in OPSCC biology.

Gene alterations in the nuclear transport receptor superfamily: A study of head and neck cancer

In cancer cells, the nuclear transport system is often disrupted, leading to abnormal localization of nuclear proteins and altered gene expression. This disruption can arise from various mechanisms such as mutations in genes that regulate nuclear transport, altered expression of transport proteins, and changes in nuclear envelope structure. Oncogenic protein build-up in the nucleus due to the disturbance in nuclear transport can also boost tumor growth and cell proliferation. In this study, we performed bioinformatic analyses of 23 key nuclear transport receptors using genomic and transcriptomic data from pancancer and head and neck squamous cell carcinoma (HNSCC) datasets from The Cancer Genome Atlas (TCGA) and Cancer Cell Line Encyclopedia and found that the total alteration frequency of 23 nuclear transport receptors in 2691 samples of the PCAWG Consortium was 42.1% and a high levels of genetic alterations was significantly associated with poor overall survival. Amplification was the most common type of genetic alterations, and results in the overexpression of nuclear transport receptors in HNSCC compared to normal tissues. Furthermore, our study revealed that seven out of eight cell cycle genes (CDK1, CDK2, CDK4, CDK6, CCNA1, CCNB1, and CCNE2) were significantly and positively correlated with nuclear transport receptor genes in TCGA pancancer and CCLE datasets. Additionally, functional enrichment analysis showed that nuclear transport receptor genes were mainly enriched in the adhesion junction, cell cycle, ERBB, MAPK, MTOR and WNT signaling pathways.

The growth hormone receptor interacts with transcriptional regulator HMGN1 upon GH-induced nuclear translocation

Growth hormone (GH) actions are mediated through binding to its cell-surface receptor, the GH receptor (GHR), with consequent activation of downstream signalling. However, nuclear GHR localisation has also been observed and is associated with increased cancer cell proliferation. Here we investigated the functional implications of nuclear translocation of the GHR in the human endometrial cancer cell-line, RL95-2, and human mammary epithelial cell-line, MCF-10A. We found that following GH treatment, the GHR rapidly translocates to the nucleus, with maximal localisation at 5-10 min. Combined immunoprecipitation-mass spectrometry analysis of RL95-2 whole cell lysates identified 40 novel GHR binding partners, including the transcriptional regulator, HMGN1. Moreover, microarray analysis demonstrated that the gene targets of HMGN1 were differentially expressed following GH treatment, and co-immunoprecipitation showed that HMGN1 associates with the GHR in the nucleus. Therefore, our results suggest that GHR nuclear translocation might mediate GH actions via interaction with chromatin factors that then drive changes in specific downstream transcriptional programs.

The effect of P53 expression and smoking/alcohol in P16(+) and P16(-) oropharyngeal carcinoma and risk classification: the Turkish Society of Radiation Oncology Head & Neck Study Group 01-002

OBJECTIVE

The aim of this study is to categorize the risk groups of patients with oropharyngeal carcinoma (OPC) according to p16 and p53 status, smoking/alcohol consumption history, and other prognostic factors.

STUDY DESIGN

The immunostaining of p16 and p53 of 290 patients was retrospectively evaluated. The history of smoking/alcohol consumption of each patient was noted. p16 and p53 staining patterns were reviewed. The results were compared with demographic findings and prognostic factors. Risk groups have been classified for the p16 status of patients.

RESULTS

The median follow-up was 47 months (range 6-240). Five-year disease-free survival (DFS) rates for patients with p16 (+) and (-) were 76% and 36%, and overall survival rates were 83% vs 40%, respectively (HR = 0.34 [0.21-0.57], P < .0001), HR = 0.22 [0.12-0.40] P < .0001, respectively). p16(-), p53(+), heavy smoking/alcohol consumption, performance status; advanced T and N stages in patients with p16(-), and continuing smoking/alcohol consumption after treatment were found to be unfavorable risk factors. Five-year overall survival rates were 95%, 78%, and 36% for low, intermediate, and high-risk groups, respectively.

CONCLUSIONS

The results of our study have shown that p16 negativity in patients with oropharyngeal cancer was found to be an important prognostic factor, especially for those with lower p53 expression and not smoking/consuming alcohol.

Nuclear Epidermal Growth Factor Receptor Overexpression as a Survival Predictor in Oral Squamous Cell Carcinoma

The aim of this study was to determine, by immunohistochemical methods, the expression of nEGFR and markers of cell proliferation (Ki-67), cell cycle (mEGFR, p53, cyclin D1), and tumor stem cells (ABCG2) in 59 pathohistological samples of healthy oral mucosa, 50 oral premalignant changes (leukoplakia and erythroplakia), and 52 oral squamous cell carcinomas (OSCC). An increase in the expression of mEGFR and nEGFR was found with the development of the disease (p < 0.0001). In the group of patients with leukoplakia and erythroplakia, we found a positive correlation between nEGFR and Ki67, p53, cyclin D1, and mEGFR, whereas in the group of patients with OSCC, we found a positive correlation between nEGFR and Ki67, mEGFR (p < 0.05). Tumors without perineural (PNI) invasion had a higher expression of p53 protein than tumors with PNI (p = 0.02). Patients with OSCC and overexpression of nEGFR had shorter overall survival (p = 0.004). The results of this study suggest a potentially important independent role of nEGFR in oral carcinogenesis.

Recent findings on the impact of ErbB receptors status on prognosis and therapy of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer type, has often an aggressive course and is poorly responsive to current therapeutic approaches, so that 5-year survival rates for patients diagnosed with advanced disease is lower than 50%. The Epidermal Growth Factor Receptor (EGFR) has emerged as an established oncogene in HNSCC. Indeed, although HNSCCs are a heterogeneous group of cancers which differ for histological, molecular and clinical features, EGFR is overexpressed or mutated in a percentage of cases up to about 90%. Moreover, aberrant expression of the other members of the ErbB receptor family, ErbB2, ErbB3 and ErbB4, has also been reported in variable proportions of HNSCCs. Therefore, an increased expression/activity of one or multiple ErbB receptors is found in the vast majority of patients with HNSCC. While aberrant ErbB signaling has long been known to play a critical role in tumor growth, angiogenesis, invasion, metastatization and resistance to therapy, more recent evidence has revealed its impact on other features of cancer cells' biology, such as the ability to evade antitumor immunity. In this paper we will review recent findings on how ErbB receptors expression and activity, including that associated with non-canonical signaling mechanisms, impacts on prognosis and therapy of HNSCC.

Targeting Epidermal Growth Factor Receptor in Head and Neck Cancer

ABSTRACT

Head and neck squamous cell carcinomas are rising in incidence worldwide, and despite the advent of improved surgical and radiation techniques, a substantial proportion of patients have disease recurrence, where systemic therapies are the mainstay of management. Recent advances in systemic therapy include the development of epidermal growth factor receptor- and programmed death 1-targeting drugs, which have produced incremental improvements in disease outcomes. However, for most patients, responses to treatment remain elusive because of primary or acquired resistance. Novel drugs and rational drug combinations need to be tested based on biomarker identification and preclinical science that will ultimately advance outcomes for our patients. This review focuses on efforts untaken for epidermal growth factor receptor targeting in head and neck squamous cell carcinoma to date.

Downregulation of annexin A3 promotes ionizing radiation-induced EGFR activation and nuclear translocation and confers radioresistance in nasopharyngeal carcinoma

Radioresistance currently poses a significant challenge to successful disease control of nasopharyngeal carcinoma (NPC). We previously uncovered that annexin A3 (ANXA3), a calcium-dependent phospholipid binding protein, is underexpressed in radioresistant NPC cells and mouse xenografts. This study aims to further unravel the mechanistic basis underlying ANXA3-mediated radioresistance in NPC. We show that either innate ANXA3 downregulation or short hairpin RNA(shRNA)-based knockdown of ANXA3 confers resistance to ionizing radiation (IR) in NPC both in vitro and in mouse xenograft models in vivo, whereas radiosensitization was observed when ANXA3 was ectopically expressed. Mechanistically, ANXA3 knockdown dramatically enhances IR-induced epidermal growth factor receptor (EGFR) phosphorylation and nuclear translocation, leading to increased post-IR phosphorylation of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) concomitant with markedly accelerated DNA DSB repair. In addition, pretreatment with cetuximab efficiently abrogated the radioresistant phenotype of ANXA3-low cells as well as the ANXA3 knockdown-induced post-IR EGFR nuclear accumulation, suggesting that EGFR is an essential mediator for ANXA3 depletion-mediated radioprotection in NPC. Collectively, this work reveals for the first time a critical role of ANXA3 in radiation survival and DNA repair mechanism of NPC and provides mechanistic evidence to support ANXA3 as a potential therapeutic target to improve radiocurability for NPC.

EGFR signaling promotes nuclear translocation of plasma membrane protein TSPAN8 to enhance tumor progression via STAT3-mediated transcription

TSPAN family of proteins are generally considered to assemble as multimeric complexes on the plasma membrane. Our previous work uncovered that TSPAN8 can translocate into the nucleus as a membrane-free form, a process that requires TSPAN8 palmitoylation and association with cholesterol to promote its extraction from the plasma membrane and subsequent binding with 14-3-3θ and importin-β. However, what upstream signal(s) regulate(s) the nuclear translocation of TSPAN8, the potential function of TSPAN8 in the nucleus, and the underlying molecular mechanisms all remain unclear. Here, we demonstrate that, epidermal growth factor receptor (EGFR) signaling induces TSPAN8 nuclear translocation by activating the kinase AKT, which in turn directly phosphorylates TSPAN8 at Ser129, an event essential for its binding with 14-3-3θ and importin ß1. In the nucleus, phosphorylated TSPAN8 interacts with STAT3 to enhance its chromatin occupancy and therefore regulates transcription of downstream cancer-promoting genes, such as MYC, BCL2, MMP9, etc. The EGFR-AKT-TSPAN8-STAT3 axis was found to be hyperactivated in multiple human cancers, and associated with aggressive phenotype and dismal prognosis. We further developed a humanized monoclonal antibody hT8^Ab4 that specifically recognizes the large extracellular loop of TSPAN8 (TSPAN8-LEL), thus being able to block the extraction of TSPAN8 from the plasma membrane and consequently its nuclear localization. Importantly, both in vitro and in vivo studies demonstrated an antitumor effect of hT8^Ab4. Collectively, we discovered an unconventional function of TSPAN8 and dissected the underlying molecular mechanisms, which not only showcase a new layer of biological complexity of traditional membrane proteins, but also shed light on TSPAN8 as a novel therapeutic target for refractory cancers.

EGFR-Targeted Photodynamic Therapy

The epidermal growth factor receptor (EGFR) plays a pivotal role in the proliferation and metastatization of cancer cells. Aberrancies in the expression and activation of EGFR are hallmarks of many human malignancies. As such, EGFR-targeted therapies hold significant potential for the cure of cancers. In recent years, photodynamic therapy (PDT) has gained increased interest as a non-invasive cancer treatment. In PDT, a photosensitizer is excited by light to produce reactive oxygen species, resulting in local cytotoxicity. One of the critical aspects of PDT is to selectively transport enough photosensitizers to the tumors environment. Accordingly, an increasing number of strategies have been devised to foster EGFR-targeted PDT. Herein, we review the recent nanobiotechnological advancements that combine the promise of PDT with EGFR-targeted molecular cancer therapy. We recapitulate the chemistry of the sensitizers and their modes of action in PDT, and summarize the advantages and pitfalls of different targeting moieties, highlighting future perspectives for EGFR-targeted photodynamic treatment of cancer.

Network pharmacology reveals the potential mechanism of Baiying Qinghou decoction in treating laryngeal squamous cell carcinoma

Context: Baiying Qinghou as a traditional Chinese medicine decoction shows anticancer property on laryngeal squamous cell carcinoma. However, little is known about the precise mechanism of Baiying Qinghou detection against laryngeal squamous cell carcinoma.

Objective: This study was aimed to explore potential mechanism of therapeutic actions of Baiying Qinghou decoction on laryngeal squamous cell carcinoma.

Materials and Methods: The active chemical components of Baiying Qinghou decoction were predicted, followed by integrated analysis of network pharmacology and molecular docking approach. The network pharmacology approach included target protein prediction, protein-protein interaction network construction and functional enrichment analysis.

Results: Sitosterol and quercetin were predicted to be the overlapped active ingredients among three Chinese herbs of Baiying Qinghou decoction. The target proteins were closely associated with response to chemical, response to drug related biological process and cancer related pathways such as PI3K-Akt signaling, HIF-1 signaling and Estrogen signaling pathway. The target proteins of TP53, EGFR, PTGS2, NOS3 and IL1B as the key nodes in PPI network were cross-validated, among which EGFR, IL1B, NOS3 and TP53 were significantly correlated with the prognosis of patients with laryngeal squamous cell carcinoma. Finally, the binding modes of EGFR, IL1B, NOS3 and TP53 with quercetin were visualized.

Discussion and Conclusion: Quercetin of Baiying Qinghou decoction showed therapeutic effect against laryngeal squamous cell carcinoma by regulating TP53, EGFR, NOS3 and IL1B involved with drug resistance and PI3K-AKT signaling pathway. TP53, EGFR, NOS3 and IL1B may be the candidate targets for the treatment of laryngeal squamous cell carcinoma.

STEAP3 promotes cancer cell proliferation by facilitating nuclear trafficking of EGFR to enhance RAC1-ERK-STAT3 signaling in hepatocellular carcinoma

STEAP3 (Six-transmembrane epithelial antigen of the prostate 3, TSAP6, dudulin-2) has been reported to be involved in tumor progression in human malignancies. Nevertheless, how it participates in the progression of human cancers, especially HCC, is still unknown. In the present study, we found that STEAP3 was aberrantly overexpressed in the nuclei of HCC cells. In a large cohort of clinical HCC tissues, high expression level of nuclear STEAP3 was positively associated with tumor differentiation and poor prognosis (p < 0.001), and it was an independent prognostic factor for HCC patients. In HCC cell lines, nuclear expression of STEAP3 significantly promoted HCC cells proliferation by promoting stemness phenotype and cell cycle progression via RAC1-ERK-STAT3 and RAC1-JNK-STAT6 signaling axes. Through upregulating the expression and nuclear trafficking of EGFR, STEAP3 participated in regulating EGFR-mediated STAT3 transactivity in a manner of positive feedback. In summary, our findings support that nuclear expression of STEAP3 plays a critical oncogenic role in the progression of HCC via modulation on EGFR and intracellular signaling, and it could be a candidate for prognostic marker and therapeutic target in HCC.

Nuclear EGFR Expression Is Associated With Poor Survival in Laryngeal Carcinoma

The membrane EGFR (mEGFR) protein overexpression in the head and neck squamous cell carcinoma (SCC) is considered to cause increased EGFR activity which adds to tumorigenicity and therapy resistance. The mEGFR upon stimulation can translocate to the nucleus nuclear EGFR (nEGFR) where it has been associated with poor prognosis and worse survival in many cancers. The relevance of differentially located EGFR proteins in laryngeal lesions has not been studied enough and remains unclear. Aim of our study was to examine nEGFR and mEGFR protein expression as well as EGFR gene status and cell cycle proliferation markers in the laryngeal polyps, dysplasia, and SCC using immunohistochemistry and in situ hybridization. There was significantly higher frequency of strong nEGFR between SCC, dysplasia, and polyps (P<0.0001), and strong mEGFR in the SCC and laryngeal dysplasia comparing to polyps (P<0.0001). Gene amplification was confirmed only in relatively small number of SCC but not in non-neoplastic lesions. In dysplasia the statistically significant positive correlations between nEGFR, and Ki-67 (P=0.029), p53 (P=0.001), and cyclin D1 (P=0.031) were found. nEGFR and mEGFR expression showed statistically significant inverse correlation in the SCC (P=0.004) as well as nEGFR and cyclin D1 (P=0.032). Univariate statistical analysis showed statistically significant correlation between strong nEGFR protein expression and worse overall survival in laryngeal SCC, alone or in coexpression with strong cyclin D1 and high Ki-67 (P=0.025, P=0.046, P=0.043, respectively). Our data show that nEGFR cellular localization might influence biology of the laryngeal carcinogenesis and is indicator of poor survival.

Prognostic Impact of Membranous/Nuclear Epidermal Growth Factor Receptor Localization in Clear Cell Renal Cell Carcinoma

EGFR is overexpressed in the majority of clear cell renal cell carcinomas (CCRCCs). Although EGFR deregulation was found to be of great significance in CCRCC biology, the EGFR overexpression is not associated with EGFR-targeted therapy responsiveness. Moreover, the prognostic role of EGFR expression remains controversial. In the present study, we evaluated the role played by EGFR overexpression in CCRCC and its prognostic significance associated with different immunohistochemical localization patterns. In our study, the Total Score (TS) related to membranous-cytoplasmic EGFR expression showed a significant correlation with grade, pathologic stage (pT), and Stage, Size, Grade, and Necrosis (SSIGN) score, and a negative correlation with nuclear EGFR expression. No significant correlations were shown between nuclear EGFR and clinic-pathological features. Additionally, a correlation between SGLT1 expression levels and pT was described. Multivariate analysis identifies pT and SSIGN score as independent prognostic factors for CCRCC. A significantly increased survival rate was found in the case of positive expression of nuclear EGFR and SGLT1. Based on our findings, SGLT1 and nuclear EGFR overexpression defines a subgroup of CCRCC patients with good prognosis. Membranous-cytoplasmic EGFR expression was shown to be a poor prognostic factor and could define a CCRCC subgroup with poor prognosis that should be responsive to anti-EGFR therapies.

Immunotherapy-based targeting of MSLN+ activated portal fibroblasts is a strategy for treatment of cholestatic liver fibrosis

We investigated the role of mesothelin (Msln) and thymocyte differentiation antigen 1 (Thy1) in the activation of fibroblasts across multiple organs and demonstrated that Msln^-/- mice are protected from cholestatic fibrosis caused by Mdr2 (multidrug resistance gene 2) deficiency, bleomycin-induced lung fibrosis, and UUO (unilateral urinary obstruction)-induced kidney fibrosis. On the contrary, Thy1^-/- mice are more susceptible to fibrosis, suggesting that a Msln-Thy1 signaling complex is critical for tissue fibroblast activation. A similar mechanism was observed in human activated portal fibroblasts (aPFs). Targeting of human MSLN⁺ aPFs with two anti-MSLN immunotoxins killed fibroblasts engineered to express human mesothelin and reduced collagen deposition in livers of bile duct ligation (BDL)-injured mice. We provide evidence that antimesothelin-based therapy may be a strategy for treatment of parenchymal organ fibrosis.

Cell Plasticity and Prostate Cancer: The Role of Epithelial-Mesenchymal Transition in Tumor Progression, Invasion, Metastasis and Cancer Therapy Resistance

Simple Summary

Although epithelial-to-mesenchymal transition (EMT) is a well-known cellular process involved during normal embryogenesis and wound healing, it also has a dark side; it is a complex process that provides tumor cells with a more aggressive phenotype, facilitating tumor metastasis and even resistance to therapy. This review focuses on the key pathways of EMT in the pathogenesis of prostate cancer and the development of metastases and evasion of currently available treatments.

Abstract

Prostate cancer, the second most common malignancy in men, is characterized by high heterogeneity that poses several therapeutic challenges. Epithelial–mesenchymal transition (EMT) is a dynamic, reversible cellular process which is essential in normal embryonic morphogenesis and wound healing. However, the cellular changes that are induced by EMT suggest that it may also play a central role in tumor progression, invasion, metastasis, and resistance to current therapeutic options. These changes include enhanced motility and loss of cell–cell adhesion that form a more aggressive cellular phenotype. Moreover, the reverse process (MET) is a necessary element of the metastatic tumor process. It is highly probable that this cell plasticity reflects a hybrid state between epithelial and mesenchymal status. In this review, we describe the underlying key mechanisms of the EMT-induced phenotype modulation that contribute to prostate tumor aggressiveness and cancer therapy resistance, in an effort to provide a framework of this complex cellular process.

Estrogen receptor β and treatment with a phytoestrogen are associated with inhibition of nuclear translocation of EGFR in the prostate

Knockout of ERβ in the mouse leads to nuclear expression of epidermal growth factor receptor (EGFR) in the prostate. To examine whether ERβ plays a similar role in the human prostate, we used four cohorts of men: 1) a Swedish cohort of normal prostates and PCa (prostate cancer) of different Gleason grades; 2) men with benign prostatic hyperplasia (BPH) treated with the 5α-reductase inhibitor, finasteride, and finasteride together with the ERβ agonists, soy isoflavones; 3) men with PCa above Gleason grade 4 (GG4), treated with ADT (androgen deprivation therapy) and abiraterone (AA), the blocker of androgen synthesis for different durations; and 4) men with GG4 PCa on ADT or ADT with the AR (androgen receptor) blocker, enzalutamide, for 4 mo to 6 mo. In men with BPH, finasteride treatment induced EGFR nuclear expression, but, when finasteride was combined with isoflavones, EGFR remained on the cell membrane. In GG4 patients, blocking of AR for 4 mo to 6 mo resulted in loss of ERβ and PTEN expression and increase in patients with nuclear EGFR from 10 to 40%. In the men with GG4 PCa, blocking of adrenal synthesis of testosterone for 2 mo to 7 mo had the beneficial effect of increasing ERβ expression, but, on treatment longer than 8 mo, ERβ was lost and EGFR moved to the nucleus. Since nuclear EGFR is a predictor of poor outcome in PCa, addition of ERβ agonists together with abiraterone should be considered as a treatment that might sustain expression of ERβ and offer some benefit to patients.

Growth Factor Receptor Expression in Oropharyngeal Squamous Cell Cancer: Her1-4 and c-Met in Conjunction with the Clinical Features and Human Papillomavirus (p16) Status

Simple Summary

Growth factor expression is a negative prognostic factor in head and neck squamous cell carcinoma (HNSCC). Targeted therapy has a limited effect on the treatment of advanced stages due to evolving resistance mechanisms. The aim of this study was to assess the distribution of growth factor receptors in oropharyngeal squamous cell cancer (OPSCC) and evaluate their role in the context of the human papillomavirus status, prognosis and possible relevance for targeted therapy. Tissue microarrays of 78 primary OPSCC, 35 related lymph node metastasis, 6 distant metastasis and 9 recurrent tumors were manufactured to evaluate the expression of human epidermal growth factor receptor (EGFR/erbB/Her)1–4 and c-Met by immunohistochemistry. EGFR and c-Met are relevant negative prognostic factors especially in noxae-induced OPSCC. Thus, dual targeting of EGFR and c-Met could be a promising prospective target in OPSCC treatment. Frequent coexpression of assessed receptors represents a possible intrinsic resistance mechanism in targeted therapy.

Abstract

This study aimed to assess the distribution of growth factor receptors in oropharyngeal squamous cell cancer (OPSCC) and evaluate their role in the context of human papillomavirus (HPV) status, prognosis and potential relevance for targeted therapy. The protein expression of human epidermal growth factor receptor (Her)1–4 and c-Met were retrospectively assessed using semiquantitative immunohistochemistry on tissue microarrays and analyzed for correlations as well as differences in the clinicopathological criteria. Her1–4 and c-met were overexpressed compared to normal mucosa in 46%, 4%, 17%, 27% and 23%, respectively. Interestingly, most receptors were coexpressed. Her1 and c-Met were inversely correlated with p16 (p = 0.04; p = 0.02). Her2 and c-Met were associated with high tobacco consumption (p = 0.016; p = 0.04). High EGFR, Her3, Her4 and c-Met expression were associated with worse overall and disease-free survival (p ≤ 0.05). Furthermore, EGFR and c-Met expression showed raised hazard ratios of 2.53 (p = 0.02; 95% CI 1.24–5.18) and 2.45 (p = 0.02; 95% CI 1.13–5.35), respectively. Her4 was expressed less in distant metastases than in corresponding primary tumors and was correlated to a higher T category. EGFR and c-Met are relevant negative prognostic factors in OPSCC, independent of known clinicopathological parameters. We suggest dual targeting of EGFR and c-Met as a promising strategy for OPSCC treatment.

Annexin A1 promotes the nuclear localization of the epidermal growth factor receptor in castration-resistant prostate cancer

Epidermal growth factor receptor is a cancer driver whose nuclear localization has been associated with the progression of prostate cancer to the castration-resistant phenotype. Previous reports indicated a functional interaction between this receptor and the protein Annexin A1, which has also been associated with aggressive tumors. The molecular pathogenesis of castration-resistant prostate cancer remains largely unresolved, and herein we have demonstrated the correlation between the expression levels and localization of the epidermal growth factor receptor and Annexin A1 in prostate cancer samples and cell lines. Interestingly, a higher expression of both proteins was detected in castration-resistant prostate cancer cell lines and the strongest correlation was seen at the nuclear level. We verified that Annexin A1 interacts with the epidermal growth factor receptor, and by using prostate cancer cell lines knocked down for Annexin A1, we succeeded in demonstrating that Annexin A1 promotes the nuclear localization of epidermal growth factor receptor. Finally, we showed that Annexin A1 activates an autocrine signaling in castration-resistant prostate cells through the formyl peptide receptor 1. The inhibition of such signaling by Cyclosporin H inhibits the nuclear localization of epidermal growth factor receptor and its downstream signaling. The present work sheds light on the functional interaction between nuclear epidermal growth factor receptor and nuclear Annexin A1 in castration-resistant prostate cancer. Therefore, strategies to inhibit the nuclear localization of epidermal growth factor receptor through the suppression of the Annexin A1 autocrine loop could represent an important intervention strategy for castration-resistant prostate cancer.

Valproic Acid Synergizes With Cisplatin and Cetuximab in vitro and in vivo in Head and Neck Cancer by Targeting the Mechanisms of Resistance

Recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) is a devastating malignancy with a poor prognosis. The combination of cisplatin (CDDP) plus cetuximab (CX) is one of the standard first-line treatments in this disease. However, this therapeutic regimen is often associated with high toxicity and resistance, suggesting that new combinatorial strategies are needed to improve its therapeutic index. In our study, we evaluated the antitumor effects of valproic acid (VPA), a well-known antiepileptic agent with histone deacetylase inhibitory activity, in combination with CDDP/CX doublet in head and neck squamous cell carcinoma (HNSCC) models. We demonstrated, in HNSCC cell lines, but not in normal human fibroblasts, that simultaneous exposure to equitoxic doses of VPA plus CDDP/CX resulted in a clear synergistic antiproliferative and pro-apoptotic effects. The synergistic antitumor effect was confirmed in four different 3D-self-assembled spheroid models, suggesting the ability of the combined approach to affect also the cancer stem cells compartment. Mechanistically, VPA enhanced DNA damage in combination treatment by reducing the mRNA expression of ERCC Excision Repair 1, a critical player in DNA repair, and by increasing CDDP intracellular concentration via upregulation at transcriptional level of CDDP influx channel copper transporter 1 and downregulation of the ATPAse ATP7B involved in CDDP-export. Valproic acid also induced a dose-dependent downregulation of epidermal growth factor receptor (EGFR) expression and of MAPK and AKT downstream signaling pathways and prevent CDDP- and/or CX-induced EGFR nuclear translocation, a well-known mechanism of resistance to chemotherapy. Indeed, VPA impaired the transcription of genes induced by non-canonical activity of nuclear EGFR, such as cyclin D1 and thymidylate synthase. Finally, we confirmed the synergistic antitumor effect also in vivo in both heterotopic and orthotopic models, demonstrating that the combined treatment completely blocked HNSCC xenograft tumors growth in nude mice. Overall, the introduction of a safe and generic drug such as VPA into the conventional treatment for R/M HNSCC represents an innovative and feasible antitumor strategy that warrants further clinical evaluation. A phase II clinical trial exploring the combination of VPA and CDDP/CX in R/M HNSCC patients is currently ongoing in our institute.

Expression and localisation of epidermal growth factor receptors and their ligands in the lower genital tract of cycling cows

The epidermal growth factor receptor (ErbB) family and its ligands are essential for the regulation of multiple cellular processes required for mammalian reproduction. The objectives of this study were to investigate the expression and localisation of ErbB subtypes (ErbB1-4) and selected ligands, namely epidermal growth factor (EGF), amphiregulin (AREG) and neuregulin (NRG), in the cervix and vagina of cycling cows and to determine possible steroid hormone-dependence of their expression using immunohistochemistry. All four ErbBs and EGF, AREG and NRG proteins were found to be localised in the nucleus and cytoplasm of different cells in the cervix and vagina, and their expression differed during the oestrous cycle. During the follicular phase, in both the cervix and vagina, ErbB1, ErbB2, ErbB3, ErbB4 and EGF expression was higher in the luminal epithelium (LE) than in stromal and smooth muscle (SM) cells (P<0.05). During the luteal phase, the expression of ErbB1, ErbB3 and EGF in the LE was significantly different from that in stromal and SM cells in the cervix, whereas the expression of EGF and AREG differed in the vagina compared to the cervix (P<0.05). Throughout the oestrous cycle, in both the cervix and vagina, although ErbB2/human epidermal growth factor receptor 2 expression in the LE and SM cells was significantly higher than in the stromal cells (P<0.05), NRG expression was similar in the LE, stromal and SM cells (P>0.05). Overall, these results suggest that all four ErbBs and the EGF, AREG and NRG proteins may collectively contribute to several cellular processes in the bovine cervix and vagina during the oestrous cycle.

Nuclear receptor tyrosine kinase transport and functions in cancer

Signaling functions of plasma membrane-localized receptor tyrosine kinases (RTKs) have been extensively studied after they were first described in the mid-1980s. Plasma membrane RTKs are activated by extracellular ligands and cellular stress stimuli, and regulate cellular responses by activating the downstream effector proteins to initiate a wide range of signaling cascades in the cells. However, increasing evidence indicates that RTKs can also be transported into the intracellular compartments where they phosphorylate traditional effector proteins and non-canonical substrate proteins. In general, internalization that retains the RTK's transmembrane domain begins with endocytosis, and endosomal RTK remains active before being recycled or degraded. Further RTK retrograde transport from endosome-Golgi-ER to the nucleus is primarily dependent on membranes vesicles and relies on the interaction with the COP-I vesicle complex, Sec61 translocon complex, and importin. Internalized RTKs have non-canonical substrates that include transcriptional co-factors and DNA damage response proteins, and many nuclear RTKs harbor oncogenic properties and can enhance cancer progression. Indeed, nuclear-localized RTKs have been shown to positively correlate with cancer recurrence, therapeutic resistance, and poor prognosis of cancer patients. Therefore, understanding the functions of nuclear RTKs and the mechanisms of nuclear RTK transport will further improve our knowledge to evaluate the potential of targeting nuclear RTKs or the proteins involved in their transport as new cancer therapeutic strategies.

Targeted therapies for non-HPV-related head and neck cancer: challenges and opportunities in the context of predictive, preventive, and personalized medicine

Head and neck squamous cell carcinoma (HNSCC) develops in the mucosal lining of the upper aerodigestive tract, principally as a result of exposure to carcinogens present in tobacco products and alcohol, with oncogenic papillomaviruses also being recognized as etiological agents in a limited proportion of cases. As such, there is considerable scope for prevention of disease development and progression. However, despite multimodal approaches to treatment, tumor recurrence and metastatic disease are common problems, and clinical outcome is unsatisfactory. As our understanding of the genetics and biochemical aberrations in HNSCC has improved, so the development and use of molecularly targeted drugs to combat the disease have come to the fore. In this article, we review molecular mechanisms that alter signal transduction downstream of the epidermal growth factor receptor (EGFR) as well as those that perturb orderly cell cycle progression, such as p53 mutation, cyclin overexpression, and loss of cyclin-dependent kinase inhibitor function. We outline some of the tactics that have been employed to combat the altered biochemistry. These include blockade of the EGFR using humanized monoclonal antibodies such as cetuximab and small molecule tyrosine kinase inhibitors (TKIs) such as erlotinib/gefitinib and subsequent generations of TKIs, restoration of p53 function using MIRA compounds, and inhibition of cyclin-dependent kinase and aurora kinase activity using drugs such as palbociclib and alisertib. Knowledge of the underlying molecular mechanisms may be utilizable in order to predict disease behavior and tailor therapeutic interventions in a more personalized approach to improve clinical response. Use of liquid biopsy, omics platforms, and salivary diagnostics hold promise in this regard.

Safety and efficacy of nimotuzumab with concurrent chemoradiotherapy in unresectable locally advanced squamous cell carcinoma of head and neck: An Indian rural hospital experience

Context:

Nimotuzumab is the only anti-epidermal growth factor receptor monoclonal antibody which can be safely added to concurrent chemoradiotherapy (CRT) to improve efficacy in the management of unresectable, locally advanced squamous cell carcinoma of head and neck (LA-SCCHN). However, the evidence available on this is limited.

Aims:

We retrospectively investigated efficacy and safety of nimotuzumab when combined with chemoradiation for LA-SCCHN.

Settings and Design:

Hospital records of 39 patients from January 2012 to December 2016 diagnosed with locally advanced (Stage III-IVb), unresectable SCCHN, and treated with concurrent CRT with weekly nimotuzumab were reviewed retrospectively after fulfilling the inclusion/exclusion criteria.

Subjects and Methods:

Tumor response was calculated as per response evaluation criteria in solid tumors criteria 1.1. Association of tumor response with independent variables was assessed. Overall survival (OS) and progression-free survival (PFS) were calculated. All patients were assessed for toxicity as per common terminology criteria for adverse events Common Terminology Criteria for Adverse Events v 4.0 (U.S. Department of health and human services, National Institutes of Health, National Cancer Institute).

Results:

At 6 months after completion of treatment, objective response rate was 97.44% with 26 (66.67%) patients attaining Complete response (CR), 12 (30.77%) patients with Partial response (PR), and one patient (2.56%) had stable disease. Subgroup analysis did not show a significant association of tumor response with independent factors. OS at 1 and 2-year was 100% and 72.9%, while PFS at 1 and 2-year was 87% and 54.40%. The incidence of Grade I, II, III, and IV toxicity was 30%, 18.18%, 41.82%, and 10%, respectively. No grade V toxicity was observed. Common adverse events observed were mucositis (33.64%), skin reaction (24.55%), neutropenia (20.91%), vomiting (18.18%), and diarrhea (2.73%).

Conclusions:

Nimotuzumab is an efficacious and safe option when added to concurrent CRT in unresectable, LA-SCCHN.

Functional role of RBM10 in lung adenocarcinoma proliferation

Lung cancer is one of the most common causes of morbidity and mortality among malignant tumors worldwide. The poor prognosis of patients with lung adenocarcinomas is primarily due to its strong ability to invade and metastasize. Recent research has indicated that RNA‑binding protein 10 (RBM10) is mutated in lung adenocarcinoma, and is closely associated with tumor proliferation and apoptosis; however, the precise role of RBM10 in lung adenocarcinoma remains unclear. Our preliminary experiments (unpublished data) revealed that RBM10 expression was upregulated in lung adenocarcinoma cell lines and tissues. In this study, we first detected the protein expression level of RBM10 in lung adenocarcinoma cells and tissues, and we then examined the effects of RBM10 overexpression and downregulation (via small interfering RNA) on the proliferation and apoptosis of stable lung adenocarcinoma cells, along with its possible mechanisms of action. We also used clinical samples of lung adenocarcinomas to verify our results. We found that RBM10 protein was overexpressed in lung adenocarcinoma cells and tissues, and it reduced p53 expression (as detected by immunofluorescence assay and western blot analysis) in A549 cells and inhibited apoptosis (as shown by flow cytometric assay). RBM10 also promoted cell growth and proliferation in vitro and increased cell migration in a cell wound scratch assay. Furthermore, we found that RBM10 activated key proliferative signaling pathways [such as the epidermal growth factor receptor (EGFR), mitogen‑activated protein kinase (MAPK) and phosphoinositide 3‑kinase (PI3K)‑AKT pathways] and inhibited apoptotic pathways. In addition, we demonstrated that a high expression of RBM10 protein in patient tissue samples was associated with a shorter overall survival time and a poor prognosis. On the whole, the findings of this study indicate that RBM10 may function as an oncogene in lung cancer, and may thus prove to be a novel therapeutic target for the prophylaxis and treatment of lung adenocarcinomas.

Phase II study of induction chemotherapy with docetaxel, cisplatin, 5-fluorouracil followed by radioimmunotherapy with cetuximab and intensity-modulated radiotherapy in combination with a carbon ion boost for locally advanced tumors of the oro-, hypopharynx and larynx

•

Trimodal approach with carbon ions was tolerable and promising.

•

No high-grade radiation adverse events were documented.

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No adverse events resulted in death of patients.

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Quality of life recovered for most aspects until the last follow-up visit.

Purpose

This phase II trial was designed to evaluate efficacy and safety of a highly intensified therapy in locally advanced squamous cell carcinoma of the oro-, hypopharynx and larynx.

Methods

In this prospective, mono-centric, open-label, non-randomized phase II trial the single treatment arm consisted of a combined induction chemotherapy with docetaxel, cisplatin, 5-fluorouracil, followed by bioradiation with the monoclonal antibody cetuximab, carbon ion boost (24Gy(RBE) in 8 fractions) and IMRT (50 Gy in 25 fractions). The trial was closed early due to slow accrual.

Results

Eight patients (median age 52.5 years) were enrolled into the trial. The median follow-up was 13 months and the 12-months locoregional tumor control, progression-free survival and overall survival rates were 100.0% each. Complete remission was achieved in 7 patients. The most commonly late radiation adverse event was xerostomia (85.7% at 12 months). Five serious adverse events with recovery were documented in 4 patients: mucositis grade 3 (n = 2), decreased lymphocyte count grade 4, febrile neutropenia grade 4 and hypersensitivity grade 3 to cetuximab (n = 1 each). Most symptom scales had their worst value at the last treatment day and recovered until the 4th follow-up visit.

Conclusion

The study treatment was tolerable and promising. Reduced quality of life recovered for most aspects until the last follow-up visit.

[Nuclear EGFR: a new mode of oncogenic signalling in cancer]

EGFR (Epidermal Growth Factor Receptor) is one of the most studied molecules in biology. From its early identification and cloning to the discovery of its role in cancer, it has been at the forefront of our understanding of Receptor Tyrosine Kinase (RTK) and cell signals that induce homeostasis, but when overexpressed, facilitate tumorigenesis. While the biological functions of EGFR traditionally involve the activation of a signaling network from the plasma membrane that includes activation of the RAS/MAPK/ERK, PI3K/AKT and STATS pathways, a new mode of EGFR signaling has been progressively decoded in which membrane-associated EGFR is transported after endocytosis from cell surface to the nucleus through endocytosis, retrograde trafficking to the Golgi, the endoplasmic reticulum and the inner nuclear membrane through a series of proteic interactions. In the nucleus, EGFR acts as a transcriptional regulator, a kinase and a physical interactor, transmits signals and is involved in multiple biological functions, including cell proliferation, tumor progression, DNA repair and replication, and resistance to cancer therapies. In this review, we will summarize current knowledge of the EGFR nuclear signaling network, including how it is delivered to the nucleus, the functions it serves in the nucleus and how these functions affect cancer progression, survival and the response to treatment.

Prognostic value of localization of epidermal growth factor receptor in lung adenocarcinoma

Background

The nuclear translocation of epidermal growth factor receptor (EGFR) has been considered to play a role in carcinogenesis. However, the relevance of differentially located EGFR proteins in lung cancer remains unclear.

Methods

We examined 161 patients with primary lung adenocarcinoma to detect EGFR expression in lung cancer cells using immunohistochemistry and determined the correlations of EGFR expression with clinical characteristics, EGFR mutations, and survival time. Moreover, we graded complete membranous staining with strong intensity as high membranous EGFR (mEGFR) expression, and nuclear EGFR staining with strong intensity as high nuclear (nEGFR) expression.

Results

The prevalence of high mEGFR and nEGFR expression in lung adenocarcinoma was 42.86 and 39.13%, respectively. After multivariate analyses, high mEGFR expression was associated with a significantly reduced mortality risk in older patients, those with a history of smoking, and those without brain metastasis (hazard ratio[95% confidential interval], HR[95% CI] = 0.55[0.32~ 0.92]; 0.51[0.26~ 0.98] and 0.56[0.33~ 0.94], in overall survival, respectively). An association between high nEGFR expression and early recurrence was observed in patients with metastasis (HR[95% CI] =1.68[1.05~ 2.68], in progression-free survival). Notably, patients with low mEGFR and low nEGFR expression had the lowest survival rate in cases without brain metastasis (p = 0.018) and with a history of smoking (p = 0.062) and total EGFR (any high mEGFR or nEGFR) expression indicated a more favorable response to platinum-based chemotherapy regardless of EGFR mutations (HR[95% CI] =0.33[0.12–0.92]; adjusted HR[95% CI] = 0.36[0.13~ 1.02] with the use of tyrosine kinase inhibitor).

Conclusions

EGFR proteins at different cellular locations in lung adenocarcinoma might influence the biology of cancer cells and are an independent indicator of more favorable prognosis and treatment response.

Electronic supplementary material

The online version of this article (10.1186/s12929-018-0451-3) contains supplementary material, which is available to authorized users.

EGFR overexpression is not common in patients with head and neck cancer. Cell lines are not representative for the clinical situation in this indication

Background

Based on expression data, Epidermal Growth Factor Receptor (EGFR) emerged as therapeutic target in Head and Neck Cancer but clinical efficacy of EGFR inhibitors was very limited. We reinvestigated the EGFR expression and activation status necessary for response in cell lines and compared that to clinical samples.

Methods

Clinical samples of head and neck squamous cell carcinoma (HNSCC, n=63), mostly from late stage (IV) and poorly or undifferentiated character and cultured cell lines (n=14) were tested by immunohistochemistry (IHC) (n=55) and sandwich immunoassays (n=63) for expression and phosphorylation of EGFR (Tyrosine-1173). Response of 14 different HNSCC cell lines to Erlotinib was tested in proliferation assays.

Results

Most HNSCC cell lines respond to Erlotinib. EGFR is phosphorylated in these cell lines. Resistant cell lines display very low level EGFR expression and phosphorylation. EGFR activity in clinical samples is significantly below that observed in cell lines. In clinical samples, EGFR is not overexpressed on the single cellular level. We show similar levels of EGFR expression in growing keratinocytes and tumor cells.

Conclusions

Cell lines are not representative of the clinical situation in HNSCC. Larger studies should investigate whether patient subgroups with activating EGFR mutations or overexpression can be identified.

Prognostic and predictive value of EGFR in head and neck squamous cell carcinoma

EGFR is an extensively studied biomarker in head and neck squamous cell carcinoma (HNSCC). In this review, we discuss the prognostic and predictive role of EGFR in HNSCC, focusing on the different molecular alterations in specific treatment modalities such as radiotherapy alone (RT), combination of surgery, RT and chemotherapy (CT), EGFR inhibitors. We considered EGFR at different molecular levels: protein expression, protein activation, gene copy number, polymorphisms, mutation, EGFRvIII expression and EGFR ligand expression.

Considering RT alone, evidence supports the predictive and prognostic role of high EGFR expression only when evaluated by quantitative assays: this may help select the patients who can mostly benefit from accelerated treatment. Conversely, no predictive biomarkers are available when treatment is a combination of surgery, CT and RT. For this combined treatment, several studies indicate that EGFR expression represents a good prognostic parameter only when measured by a “quantitative” or at least semi-quantitative method. With respect to EGFR inhibitors, neither EGFR expression nor increased gene copy number represent prognostic/predictive factors.

If validated, nuclear EGFR, TGFα levels, EGFR phopshorylation and polymorphisms could represent additional prognostic factors in relation to combination of surgery, CT and RT, while EGFR polymorphisms and high amphiregulin levels could have prognostic value in patients treated with EGFR inhibitors.

Transcriptional Analysis Reveals Evidence of Chronically Impeded ECM Turnover and Epithelium-to-Mesenchyme Transition in Scar Tissue Giving Rise to Marjolin's Ulcer

Marjolin's ulcer (MU) is an aggressive malignancy arising within chronic wounds. A major cause is unhealed burn injuries. This results in well-differentiated squamous cell carcinoma (SCC). This study aimed to elucidate transcriptional changes leading to malignancy by investigating differentially expressed genes in squamous cells present in a SCC compared with MU. MU tumor cells were isolated from histologically confirmed biopsy of SCC within an unhealed burn scar. Epithelial cells (ECs) adjacent to the tumor were co-isolated and a SCC cell line was commercially purchased. mRNA from all three samples was isolated and its expression was quantified using RNASeq. A threshold of log2fold change >2-fold in either direction was considered "differentially expressed." Gene expression analysis revealed distinct differences in gene expression in MU cells compared with EC (665 genes), EC and SCC (1673 genes). Enrichment analysis confirmed that pathways most affected included 1) elevation of genes associated with extracellular matrix organization/degradation, 2) activation of DNA damage, and 3) activation of cytokine signaling. Our analysis revealed two key insights about chronic wound microenvironment conducive to ulceration. First, in EC vs. MU comparison, downregulation of Collagen and Matrix metalloproteinase families suggests chronically impaired extracellular matrix turnover giving rise to a fibrotic microenvironment. Second, in SCC vs. MU comparison, dysregulation of cadherin-mediated cell-cell adhesions is suggestive of epithelial-to-mesenchymal transitions, similar to those during development. Acquisition of epithelial-to-mesenchymal transition may underlie the high metastatic rate in MU tumors. Taken together, this sheds light on mechanisms that underlie the divergent clinical features of these cutaneous cancers.

An immunohistochemical score to predict the outcome for oral squamous cell carcinoma

BACKGROUND

Oral cancer is a major public health problem worldwide, with a poor survival. Our aim was to evaluate several protein markers in oral squamous cell carcinomas (OSCC) and analyse their prognostic value on patient's survival.

METHODS

We analysed the expression of EGFR, p53, p27, p16, cyclin D1, cyclin A2, COX-2, Ki-67, Bcl-2, VEGFR-1 and VEGFR-2, by immunohistochemistry on 67 primary OSCC. Cancer-specific survival (CSS) analysis was evaluated by the Cox regression model.

RESULTS

Markers showed variable expression between 27.9% and 95.2%. In univariate analysis for CSS, we found that four of the tested markers, namely high expression of p53 (P = .001), EGFR (P = .003), cyclin A2 (P = .005) and low expression of p16 (P = .019), along with clinical stage (P < .001), tumour size (P < .001), presence of nodal metastasis (P < .001) and perineural permeation (P = .039) were related to decreased survival. On the basis of these results, we constructed an immunohistochemical score hinging on the possibility that any tumour could express none of these four markers (score 0), one or two markers (score 1) and three or more markers (score 2). In multivariable analysis, this immunohistochemical score revealed an independent prognostic value on cancer-specific survival (P = .001; HR: 3.7: 95%CI 1.7-7.9). Moreover, we confirmed that in early-stage tumours (stage I or II) this score maintained its independent prognostic value (P = .025; HR: 7.9, 95%CI 1.3-49.1) on CSS.

CONCLUSION

The expression of the markers p53, p16, EGFR and cyclin A in OSCC, combined to give an immunohistochemical score, may identify high-risk subgroups for decreased survival and to further guide therapeutic decisions.

Intravesicular epidermal growth factor receptor subject to retrograde trafficking drives epidermal growth factor-dependent migration

The Epidermal Growth Factor Receptor (EGFR) is frequently mutated and overexpressed in metastatic cancer. Although EGFR is a transmembrane tyrosine kinase localized to the basolateral membrane in normal epithelium, it is frequently found intracellularly localized in transformed cells. We have previously demonstrated the epithelial adaptor protein mucin 1 (MUC1) alters trafficking of EGFR, inhibiting its degradation and promoting its translocation to the nucleus, where it can directly modulate gene transcription. Here, we demonstrate that MUC1 promotes the retention of EGF-bound EGFR in Early Endosome Antigen1 (EEA1)-positive vesicles while preventing its trafficking to the lysosome. These events result in the accumulation of endosomal vesicles harboring active receptor throughout the cell and a reorganization of the actin cytoskeleton. EGF-dependent cell migration and filopodia formation is reliant upon this altered trafficking, and can be prevented by blocking retrograde trafficking. Together, these results indicate that intracellular EGFR may play an essential role in cancer metastasis and a potential mechanism for the failure of therapeutic antibodies in EGFR-driven metastatic breast cancer.

EGFR-Targeted Magnetic Nanovectors Recognize, in Vivo, Head and Neck Squamous Cells Carcinoma-Derived Tumors

Head and neck squamous cell carcinomas (HNSCC) are a diverse group of tumors with high morbidity and mortality that have remained mostly unchanged over the past decades. The epidermal growth factor receptor (EGFR) is often overexpressed and activated in these tumors and strongly contributes to their pathogenesis. Still, EGFR-targeted therapies such as monoclonal antibodies and kinase inhibitors have demonstrated only limited improvements in the clinical outcome of this disease. Here, we take advantage of the extraordinary affinity of EGF for its cognate receptor to specifically target magnetite-containing nanoparticles to HNSCC cells and mediate, in vitro, their cellular upload. On the basis of this, we show efficient accumulation, in vivo, of such nanoparticles in subcutaneous xenograft tumor tissues in sufficient amounts to be able to mediate visualization by magnetic resonance imaging. Overall, our EGF-coated nanosystem may warrant, in the near future, novel and very efficient theranostic approaches to HNSCC.

Molecular-Targeted Therapies for Epidermal Growth Factor Receptor and Its Resistance Mechanisms

Cancer therapies targeting epidermal growth factor receptor (EGFR), such as small-molecule kinase inhibitors and monoclonal antibodies, have been developed as standard therapies for several cancers, such as non-small cell lung cancer, colorectal cancer, pancreatic cancer, breast cancer, and squamous cell carcinoma of the head and neck. Although these therapies can significantly prolong progression-free survival, curative effects are not often achieved because of intrinsic and/or acquired resistance. The resistance mechanisms to EGFR-targeted therapies can be categorized as resistant gene mutations, activation of alternative pathways, phenotypic transformation, and resistance to apoptotic cell death. Analysis of the processes that modulate EGFR signal transduction by EGFR-targeted inhibitors, such as tyrosine kinase inhibitors and monoclonal antibodies, has revealed new therapeutic opportunities and has elucidated novel mechanisms contributing to the discovery of more effective anticancer treatments. In this review, we discuss the roles of EGFR in cancer development, therapeutic strategies for targeting EGFR, and resistance mechanisms to EGFR-targeted therapies, with a focus on cancer therapies for individual patients.

The role of HER2, EGFR, and other receptor tyrosine kinases in breast cancer

Breast cancer affects approximately 1 in 8 women, and it is estimated that over 246,660 women in the USA will be diagnosed with breast cancer in 2016. Breast cancer mortality has decline over the last two decades due to early detection and improved treatment. Over the last few years, there is mounting evidence to demonstrate the prominent role of receptor tyrosine kinases (RTKs) in tumor initiation and progression, and targeted therapies against the RTKs have been developed, evaluated in clinical trials, and approved for many cancer types, including breast cancer. However, not all breast cancers are the same as evidenced by the multiple subtypes of the disease, with some more aggressive than others, showing differential treatment response to different types of drugs. Moreover, in addition to canonical signaling from the cell surface, many RTKs can be trafficked to various subcellular compartments, e.g., the multivesicular body and nucleus, where they carry out critical cellular functions, such as cell proliferation, DNA replication and repair, and therapeutic resistance. In this review, we provide a brief summary on the role of a selected number of RTKs in breast cancer and describe some mechanisms of resistance to targeted therapies.

Evaluation of FGFR3 as a Therapeutic Target in Head and Neck Squamous Cell Carcinoma

BACKGROUND

Although head and neck squamous cell carcinoma (HNSCC) is the sixth most common tumour entity worldwide, it remains a clinical challenge. Large-scale explorative genomic projects have identified several genes as potential targets for therapy, including fibroblast growth factor receptor 3 (FGFR3).

AIMS

The aim of this study was to investigate the biological significance of wild-type and mutated FGFR3 to evaluate its potential as a novel therapeutic target in HNSCC.

METHODS

FGFR3 protein expression was analysed in a large HNSCC tissue cohort (n = 536) and FGFR3 mRNA expression from The Cancer Genome Atlas (TCGA; n = 520). Moreover, FGFR3 wild-type and mutant versions were overexpressed in vitro, and both proliferation and migration was assessed with and without BGJ398 (a specific FGFR1-3 inhibitor) treatment.

RESULTS

Although FGFR3 expression for both cohorts decreased during tumour progression, high FGFR3 expression levels were observed in a small subset of patients. In vitro, FGFR3 overexpression led to increased proliferation, whereas migration was not altered. Moreover, FGFR3-overexpressing cells were more sensitive to BGJ398. Cells overexpressing FGFR3 mutant versions showed increased proliferation compared to wild-type FGFR3 under serum-reduced conditions and were largely as sensitive as the wild-type protein to BGJ398.

CONCLUSIONS

Taken together, the results of this study demonstrate that although FGFR3 expression decreases during HNSSC progression, it plays an important role in tumour cell proliferation and thus may be a potential target for therapy in selected patients suffering from this dismal tumour entity.

Expression and role of TYRO3 and AXL as potential therapeutical targets in leiomyosarcoma

Background:

Leiomyosarcoma (LMS) are 15% of adult sarcomas and remain seldom curable in metastatic phase. The TAM receptors and their ligands are overexpressed or activated in multiple malignancies, including LMS.

Methods:

The TAM receptor and ligand expression was evaluated in LMS cell lines and 358 sarcoma samples by either gene expression or immunohistochemistry. TYRO3 and AXL were knocked down. Crizotinib and foretinib were investigated in vitro.

Results:

High expression of TYRO3 and AXL was detected in LMS cell lines. TYRO3 or AXL gene knockdown reduced cell proliferation/colony formation. Crizotinib and foretinib decreased TYRO3 and AXL phosphorylation, apoptosis, G2/arrest and reduced colony formation. Immunohistochemistry performed in 107 sarcomas showed higher expression of TYRO3 and GAS6 in LMS vs other sarcomas and nuclear TYRO3 only in LMS. Microarray gene expression performed in 251 sarcomas revealed significantly higher expression of TYRO3 and GAS6 in LMS than other sarcomas. Leiomyosarcoma patients with high expression of GAS6 or PROS1 present a significantly worse PFS.

Conclusions:

Leiomyosarcoma patients, especially those whom develop metastasis, express higher levels of TYRO3 and GAS6. Crizotinib and foretinib showed effective antitumour activity in LMS through TYRO3 and AXL deactivation indicating that clinical trials using TYRO3 and AXL inhibitors are warranted in advanced LMS.

Biological determinants of radioresistance and their remediation in pancreatic cancer

Despite recent advances in radiotherapy, a majority of patients diagnosed with pancreatic cancer (PC) do not achieve objective responses due to the existence of intrinsic and acquired radioresistance. Identification of molecular mechanisms that compromise the efficacy of radiation therapy and targeting these pathways is paramount for improving radiation response in PC patients. In this review, we have summarized molecular mechanisms associated with the radio-resistant phenotype of PC. Briefly, we discuss the reversible and irreversible biological consequences of radiotherapy, such as DNA damage and DNA repair, mechanisms of cancer cell survival and radiation-induced apoptosis following radiotherapy. We further describe various small molecule inhibitors and molecular targeting agents currently being tested in preclinical and clinical studies as potential radiosensitizers for PC. Notably, we draw attention towards the confounding effects of cancer stem cells, immune system, and the tumor microenvironment in the context of PC radioresistance and radiosensitization. Finally, we discuss the need for examining selective radioprotectors in light of the emerging evidence on radiation toxicity to non-target tissue associated with PC radiotherapy.

Epidermal Growth Factor Receptor Cell Proliferation Signaling Pathways

The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is commonly upregulated in cancers such as in non-small-cell lung cancer, metastatic colorectal cancer, glioblastoma, head and neck cancer, pancreatic cancer, and breast cancer. Various mechanisms mediate the upregulation of EGFR activity, including common mutations and truncations to its extracellular domain, such as in the EGFRvIII truncations, as well as to its kinase domain, such as the L858R and T790M mutations, or the exon 19 truncation. These EGFR aberrations over-activate downstream pro-oncogenic signaling pathways, including the RAS-RAF-MEK-ERK MAPK and AKT-PI3K-mTOR pathways. These pathways then activate many biological outputs that are beneficial to cancer cell proliferation, including their chronic initiation and progression through the cell cycle. Here, we review the molecular mechanisms that regulate EGFR signal transduction, including the EGFR structure and its mutations, ligand binding and EGFR dimerization, as well as the signaling pathways that lead to G1 cell cycle progression. We focus on the induction of CYCLIN D expression, CDK4/6 activation, and the repression of cyclin-dependent kinase inhibitor proteins (CDKi) by EGFR signaling pathways. We also discuss the successes and challenges of EGFR-targeted therapies, and the potential for their use in combination with CDK4/6 inhibitors.

Epidermal Growth Factor Receptor Cell Proliferation Signaling Pathways

The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is commonly upregulated in cancers such as in non-small-cell lung cancer, metastatic colorectal cancer, glioblastoma, head and neck cancer, pancreatic cancer, and breast cancer. Various mechanisms mediate the upregulation of EGFR activity, including common mutations and truncations to its extracellular domain, such as in the EGFRvIII truncations, as well as to its kinase domain, such as the L858R and T790M mutations, or the exon 19 truncation. These EGFR aberrations over-activate downstream pro-oncogenic signaling pathways, including the RAS-RAF-MEK-ERK MAPK and AKT-PI3K-mTOR pathways. These pathways then activate many biological outputs that are beneficial to cancer cell proliferation, including their chronic initiation and progression through the cell cycle. Here, we review the molecular mechanisms that regulate EGFR signal transduction, including the EGFR structure and its mutations, ligand binding and EGFR dimerization, as well as the signaling pathways that lead to G1 cell cycle progression. We focus on the induction of CYCLIN D expression, CDK4/6 activation, and the repression of cyclin-dependent kinase inhibitor proteins (CDKi) by EGFR signaling pathways. We also discuss the successes and challenges of EGFR-targeted therapies, and the potential for their use in combination with CDK4/6 inhibitors.

Role of EGFR as prognostic factor in head and neck cancer patients treated with surgery and postoperative radiotherapy: proposal of a new approach behind the EGFR overexpression

In an era of personalized treatment, there is a great interest in identifying factors which might predict patient response to radiotherapy (RT). The role of epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinoma (HNSCC) remains still controversial. We performed a retrospective analysis on the prognostic value of EGFR in HNSCC patients treated with surgery and postoperative RT through a semiquantitative immunohistochemical analysis of EGFR membrane expression. We retrospectively analyzed 65 HNSCC patients treated in our Institute from 1997 to 2003 who underwent adjuvant RT after surgery. Median follow-up was 43.5 months (range 0.2-173 months). None of these patients were treated with postoperative concomitant chemotherapy. Tumor samples were obtained from surgical specimens. Membrane features (intensity, extension) of EGFR expression were evaluated, and a statistical analysis (univariate and multivariate) was conducted to correlate these parameters with overall survival (OS) and disease-free survival (DFS). Patients with an intense and complete labeling of EGFR presented worse OS and DFS compared with groups obtained by all other possible combination, and the difference was borderline statistically significant (P = 0.08 for OS and P = 0.006 for DFS). Moreover, a stratification of patients was performed considering EGFR expression on the tumor tissue and classifying its distribution as "homogeneous" or "heterogeneous." We found that patients showing an "heterogeneous" EGFR expression distribution had worse OS and DFS compared to the "homogeneous" group of patients. Based on our results, EGFR expression, especially referring to membrane features (semiquantitative analysis), might have a prognostic value for OS and DFS in locally advanced HNSCC treated with surgery and adjuvant RT. Prospective trials could be useful to confirm the prognostic role of EGFR expression and also to assess a predictive role to select that might benefit from more aggressive treatments.

Analysis of origin and protein-protein interaction maps suggests distinct oncogenic role of nuclear EGFR during cancer evolution

Receptor tyrosine kinase EGFR usually is localized on plasma membrane to induce progression of many cancers including cancers in children (Bodey et al. In Vivo. 2005, 19:931-41), but it contains a nuclear localization signal (NLS) that mediates EGFR nuclear translocation (Lin et al. Nat Cell Biol. 2001, 3:802-8). Here we report that NLS of EGFR has its old evolutionary origin. Protein-protein interaction maps suggests that nEGFR pathways are different from membrane EGFR and EGF is not found in nEGFR network while androgen receptor (AR) is found, which suggests the evolution of prostate cancer, a well-known AR driven cancer, through changes in androgen- or EGF-dependence. Database analysis suggests that nEGFR correlates with the tumor grades especially in prostate cancer patients. Structural predication analysis suggests that NLS can compromise the differential protein binding to EGFR through stretch linkers with evolutionary mutation from N to V. In experiment, elevation of nEGFR but not membrane EGFR was found in castration resistant prostate cancer cells. Finally, systems analysis of NLS and transmembrane domain (TM) suggests that NLS has old origin while NLS neighboring domain of TM has been undergone accelerated evolution. Thus nEGFR has an old origin resembling the cancer evolution but TM may interfere with NLS driven signaling for natural selection of survival to evade NLS induced aggressive cancers. Our data suggest NLS is a dynamic inducer of EGFR oncogenesis during evolution for advanced cancers. Our model provides novel insights into the evolutionary role of NLS of oncogenic kinases in cancers.

Expression and Function of the Epidermal Growth Factor Receptor in Physiology and Disease

The epidermal growth factor receptor (EGFR) is the prototypical member of a family of membrane-associated intrinsic tyrosine kinase receptors, the ErbB family. EGFR is activated by multiple ligands, including EGF, transforming growth factor (TGF)-α, HB-EGF, betacellulin, amphiregulin, epiregulin, and epigen. EGFR is expressed in multiple organs and plays important roles in proliferation, survival, and differentiation in both development and normal physiology, as well as in pathophysiological conditions. In addition, EGFR transactivation underlies some important biologic consequences in response to many G protein-coupled receptor (GPCR) agonists. Aberrant EGFR activation is a significant factor in development and progression of multiple cancers, which has led to development of mechanism-based therapies with specific receptor antibodies and tyrosine kinase inhibitors. This review highlights the current knowledge about mechanisms and roles of EGFR in physiology and disease.

High-throughput automated scoring of Ki67 in breast cancer tissue microarrays from the Breast Cancer Association Consortium

Automated methods are needed to facilitate high-throughput and reproducible scoring of Ki67 and other markers in breast cancer tissue microarrays (TMAs) in large-scale studies. To address this need, we developed an automated protocol for Ki67 scoring and evaluated its performance in studies from the Breast Cancer Association Consortium. We utilized 166 TMAs containing 16,953 tumour cores representing 9,059 breast cancer cases, from 13 studies, with information on other clinical and pathological characteristics. TMAs were stained for Ki67 using standard immunohistochemical procedures, and scanned and digitized using the Ariol system. An automated algorithm was developed for the scoring of Ki67, and scores were compared to computer assisted visual (CAV) scores in a subset of 15 TMAs in a training set. We also assessed the correlation between automated Ki67 scores and other clinical and pathological characteristics. Overall, we observed good discriminatory accuracy (AUC = 85%) and good agreement (kappa = 0.64) between the automated and CAV scoring methods in the training set. The performance of the automated method varied by TMA (kappa range= 0.37-0.87) and study (kappa range = 0.39-0.69). The automated method performed better in satisfactory cores (kappa = 0.68) than suboptimal (kappa = 0.51) cores (p-value for comparison = 0.005); and among cores with higher total nuclei counted by the machine (4,000-4,500 cells: kappa = 0.78) than those with lower counts (50-500 cells: kappa = 0.41; p-value = 0.010). Among the 9,059 cases in this study, the correlations between automated Ki67 and clinical and pathological characteristics were found to be in the expected directions. Our findings indicate that automated scoring of Ki67 can be an efficient method to obtain good quality data across large numbers of TMAs from multicentre studies. However, robust algorithm development and rigorous pre- and post-analytical quality control procedures are necessary in order to ensure satisfactory performance.

Molecular pathways in head and neck cancer: EGFR, PI3K, and more

The treatment of head and neck squamous cell carcinoma (HNSCC) is set to undergo rapid changes, as novel treatment targets informed by genomic profiling and novel molecularly targeted therapies continue to make strides. In this review we provide an overview of the latest developments regarding (1) EGFR targeting for HNSCC, (2) PI3K as a novel treatment target, and (3) newly described key genetic events in HNSCC such as NOTCH1 mutations and emerging candidate targets including ALK1 and hedgehog. The first molecular targeting strategy to demonstrate a survival advantage for patients with HNSCC has emerged in the context of EGFR biology. Cetuximab remains the only U.S. Food and Drug Administration (FDA)-approved targeted therapy available for HNSCC, but EGFR as a target has not been individualized in this disease. The PI3K-AKT pathway is downstream of EGFR and is emerging as potentially one of the most important pathways in HNSCC. PIK3CA is the most frequently mutated oncogene for HNSCC (approximately 20%) and may play a role for both HPV-negative and HPV-positive tumors. Multiple therapeutic strategies targeting PI3K are being explored, and multiple agents either alone or in combination are in development. NOTCH1 is a key tumor suppressor gene and its genetic alterations lead to abnormal pathway activation. ALK1 is a novel target involved in angiogenesis, and efficacy in patients with HNSCC was documented in an early inhibitor trial. The hedgehog pathway modulates EGFR dependence and epithelial to mesenchymal transition (EMT), a key invasion and drug-resistance mechanism in HNSCC.

Inner nuclear membrane localization of epidermal growth factor receptor (EGFR) in spontaneous canine model of invasive micropapillary carcinoma of the mammary gland

The epidermal growth factor receptor (EGFR) has been described in the nucleus of primary tumors. Accumulation of EGFR at the nucleus is linked to DNA synthesis and cell proliferation, but the pathological significance of nuclear EGFR is not completely understood. The aim of this study was to investigate the nuclear localization of EGFR in invasive micropapillary carcinoma (IMPC) that is an aggressive neoplasm of canine mammary gland. Confocal immunofluorescence of formalin and paraffin-embedded tissue was used to access the subcellular localization of EGFR. Our results demonstrated that EGFR co-localizes with the inner nuclear envelope marker, Lamin B1 in IMPC. Furthermore, EGFR was not localized within the nucleus or at the inner nuclear envelope membrane in mammary carcinoma in mixed tumor (CMT) that is associated with a better prognosis than other malignant histological types. This finding could be useful as a predictive biomarker of therapeutic response for IMPC.

EGFR and HER2 signaling in breast cancer brain metastasis

Breast cancer occurs in approximately 1 in 8 women and 1 in 37 women with breast cancer succumbed to the disease. Over the past decades, new diagnostic tools and treatments have substantially improved the prognosis of women with local diseases. However, women with metastatic disease still have a dismal prognosis without effective treatments. Among different molecular subtypes of breast cancer, the HER2-enriched and basal-like subtypes typically have higher rates of metastasis to the brain. Basal-like metastatic breast tumors frequently express EGFR. Consequently, HER2- and EGFR-targeted therapies are being used in the clinic and/or evaluated in clinical trials for treating breast cancer patients with brain metastases. In this review, we will first provide an overview of the HER2 and EGFR signaling pathways. The roles that EGFR and HER2 play in breast cancer metastasis to the brain will then be discussed. Finally, we will summarize the preclinical and clinical effects of EGFR- and HER2-targeted therapies on breast cancer metastasis.