Epidermal growth factor receptor (EGFR) as a target in cancer therapy: understanding the role of receptor expression and other molecular determinants that could influence the response to anti-EGFR drugs

Epidermal Growth Factor Receptor (EGFR) Inhibitors Screened from Autodisplayed Fv-Antibody Library

Inhibitors of the epithermal growth factor receptor (EGFR) were screened from an autodisplayed Fv-antibody library using an anti-EGF antibody. The Fv-antibody library was expressed on the outer membrane of Escherichia coli, which corresponds to the heavy chain VH region of immunoglobulin G. The library was constructed by randomizing the CDR3 region of expressed VH regions (11 amino acid residues) by site-directed mutagenesis. Using an anti-EGF antibody as a screening probe, amino acid sequences (CDR3 region) with antibody binding affinity were screened from the Fv-antibody library. These amino acid sequences were considered to have similar chemical properties to EGF, which can bind to EGFR. Two autodisplayed clones with Fv-antibodies against EGFR were screened from the Fv-antibody library, and the screened Fv-antibodies were expressed as soluble proteins. The binding affinity (KD) was estimated using an SPR biosensor, and the inhibitory activity of expressed Fv-antibodies was observed for PANC-1 pancreatic tumor cells and T98G glioblastoma cells using Western blot analysis of proteins in the EGFR-mediated signaling pathway. The viability of PANC-1 and T98G cells was observed to decrease via the inhibitory activity of expressed Fv-antibodies. Finally, interactions between Fv-antibodies and EGFR were analyzed by using molecular docking simulations.

Interpretation of Epidermal Growth Factor Receptor Status in Microscopic Tumor-Free Surgical Margins and Lymph Nodes in Patients with Oral Squamous Cell Carcinoma: An Analysis of 125 Margins

Background

Squamous cell carcinomas are the most common type of oral cancer contributing for around 90%. The overall survival is below 50% for these patients. There is a requirement for a non-invasive marker to predict the prognosis. The epidermal growth factor (EGF) and their receptors (EGFR, ErbB-1) are not only documented to play a critical and an influential role in cell growth and differentiation in normal/healthy tissues, but may also plays an important role in malignant disease progression and tumorigenesis.

Objective

This study was done to find the significance of EGF receptor expression on microscopic free tumour margins and lymph nodal margins to predict the survival of the patient in a 2-year follow-up.

Materials and Methods

A prospective cohort study of 25 patients was performed in biopsy proven oral squamous cell carcinoma patients who reported to our department from July 2017 to June 2019. The data were collected from their histopathological report, they were- pTNM staging, surgical margins (superior and inferior, anterior, posterior), nodal status and scoring of EGFR expression on wax blocks was done. Total of 125 wax blocks were analysed for the study. Follow-up of 2 years were recorded in the study to evaluate the survival of the patients.

Result

The expression of EGFR on microscopic tumour-free surgical margins and lymph nodes was p value 0.023 which was statistically significant. The level of significance between EGFR and status of patients after 2-year follow-up was having p value 0.031. Out of 25 patients, 5 patients were dead at a 2-year follow-up. Out of these 5 patients who were dead, 3 patients had a local recurrence and 2 patients had distant metastasis.

Conclusion

This cohort study concludes that EGFR is an important prognostic marker and must be analysed in all microscopic tumour-free margins and lymph nodes in advanced oral squamous cell carcinomas to predict the local recurrences affecting the survival of the patients and the need for addition of anti-EGFR agents in adjuvant treatment. Since the sample size is small, large scale studied must be done to validate the need for adding anti-EGFR agents in adjuvant treatment to improve the survival of patients.

Recent advances in nano/microfluidics-based cell isolation techniques for cancer diagnosis and treatments

Miniaturization has improved significantly in the recent decade, which has enabled the development of numerous microfluidic systems. Microfluidic technologies have shown great potential for separating desired cells from heterogeneous samples, as they offer benefits such as low sample consumption, easy operation, and high separation accuracy. Microfluidic cell separation approaches can be classified into physical (label-free) and biological (labeled) methods based on their working principles. Each method has remarkable and feasible benefits for the purposes of cancer detection and therapy, as well as the challenges that we have discussed in this article. In this review, we present the recent advances in microfluidic cell sorting techniques that incorporate both physical and biological aspects, with an emphasis on the methods by which the cells are separated. We first introduce and discuss the biological cell sorting techniques, followed by the physical cell sorting techniques. Additionally, we explore the role of microfluidics in drug screening, drug delivery, and lab-on-chip (LOC) therapy. In addition, we discuss the challenges and future prospects of integrated microfluidics for cell sorting.

The importance of cancer-associated fibroblasts in targeted therapies and drug resistance in breast cancer

Cancer-associated fibroblasts (CAFs) play a substantial role in the tumor microenvironment, exhibiting a strong association with the advancement of various types of cancer, including breast, pancreatic, and prostate cancer. CAFs represent the most abundant mesenchymal cell population in breast cancer. Through diverse mechanisms, including the release of cytokines and exosomes, CAFs contribute to the progression of breast cancer by influencing tumor energy metabolism, promoting angiogenesis, impairing immune cell function, and remodeling the extracellular matrix. Moreover, CAFs considerably impact the response to treatment in breast cancer. Consequently, the development of interventions targeting CAFs has emerged as a promising therapeutic approach in the management of breast cancer. This article provides an analysis of the role of CAFs in breast cancer, specifically in relation to diagnosis, treatment, drug resistance, and prognosis. The paper succinctly outlines the diverse mechanisms through which CAFs contribute to the malignant behavior of breast cancer cells, including proliferation, invasion, metastasis, and drug resistance. Furthermore, the article emphasizes the potential of CAFs as valuable tools for early diagnosis, targeted therapy, treatment resistance, and prognosis assessment in breast cancer, thereby offering novel approaches for targeted therapy and overcoming treatment resistance in this disease.

Structural Perspectives in the Development of Novel EGFR Inhibitors for the Treatment of NSCLC

Non-small cell Lung cancer (NSCLC) is the most common type of lung cancer, which is caused by high consumption of tobacco and smoking. It is an epithelial lung cancer that affects about 2.2 million people across the globe, according to International Agency for Research on Cancer (IARC). Non-small cell lung cancer is a malignant tumor caused by EGFR mutation that occurs in the in-frame deletion of exon 19 and L858R point mutation in exon 21. Presently, clinically available inhibitors of EGFR (including erlotinib, lapatinib, gefitinib, selumetinib, etc.) are not specific and responsible for undesirable adverse effects. Moreover, to solve this problem search for newer EGFR inhibitors is the utmost need for the treatment and/or management of increasing lung cancer burden. The discovery of therapeutic agents that inhibit the specific target in tumorous cells, such as EGFR, is one of the successful strategies in treating many cancer therapies, including lung cancer. The exhaustive literature survey (2018-2023) has shown the importance of medicinally privileged pyrimidine derivatives together, fused and/or clubbed with other heterocyclic rings to design and develop novel EGFR inhibitors. Pyrimidine derivatives substituted with phenylamine, indole, pyrrole, piperazine, pyrazole, thiophene, pyridine and quinazoline derivatives substituted with phenylamine, pyrimidine, morpholine, pyrrole, dioxane, acrylamide, indole, pyridine, furan, pyrimidine, pyrazole etc. are privileged heterocyclic rings shown promising activity by inhibiting EGFR and TKIs. The present review summarizes the structure-activity relationship (SAR) and enzyme inhibitory activity, including IC50 values, percentage inhibition, and kinetic studies of potential compounds from various literature. The review also includes various aspects of molecular docking studies with compounds under clinical trials and patents filed on pyrimidine-based EGFR inhibitors in treating non-small cell lung cancer. The present review may benefit the medicinal chemist for developing novel compounds such as EGFR inhibitors.

ImmunoPET Targeting Receptor Tyrosine Kinase: Clinical Applications

Receptor tyrosine kinases, or RTKs, are one large family of cell surface receptors involved in signal transduction, which represent an integral part of the signaling pathways. They play a crucial role in most important cellular processes, starting with the cell cycle, proliferation and differentiation, as well as cell migration, metabolism and survival. The introduction of ImmunoPET evaluating the expression of RTKs by specific monoclonal antibodies (mAbs) or antibody fragments is regarded as a promising tool for imaging treatment efficacy and developing anticancer therapeutics. Our review focuses mainly on the current clinical research regarding ImmunoPET targeting RTKs, with particular interest in the epidermal growth factor family, or HER family, and vascular endothelial-derived growth factor/receptor.

Machine Learning-Based Approach to Developing Potent EGFR Inhibitors for Breast Cancer-Design, Synthesis, and In Vitro Evaluation

The epidermal growth factor receptor (EGFR) is vital for regulating cellular functions, including cell division, migration, survival, apoptosis, angiogenesis, and cancer. EGFR overexpression is an ideal target for anticancer drug development as it is absent from normal tissues, marking it as tumor-specific. Unfortunately, the development of medication resistance limits the therapeutic efficacy of the currently approved EGFR inhibitors, indicating the need for further development. Herein, a machine learning-based application that predicts the bioactivity of novel EGFR inhibitors is presented. Clustering of the EGFR small-molecule inhibitor (∼9000 compounds) library showed that N-substituted quinazolin-4-amine-based compounds made up the largest cluster of EGFR inhibitors (∼2500 compounds). Taking advantage of this finding, rational drug design was used to design a novel series of 4-anilinoquinazoline-based EGFR inhibitors, which were first tested by the developed artificial intelligence application, and only the compounds which were predicted to be active were then chosen to be synthesized. This led to the synthesis of 18 novel compounds, which were subsequently evaluated for cytotoxicity and EGFR inhibitory activity. Among the tested compounds, compound 9 demonstrated the most potent antiproliferative activity, with 2.50 and 1.96 μM activity over MCF-7 and MDA-MB-231 cancer cell lines, respectively. Moreover, compound 9 displayed an EGFR inhibitory activity of 2.53 nM and promising apoptotic results, marking it a potential candidate for breast cancer therapy.

The mechanism of flavonoids from Cyclocarya paliurus on inhibiting liver cancer based on in vitro experiments and network pharmacology

Introduction: Cyclocarya paliurus (Batal.) Iljinsk., a subtropical tree belonging to the family Juglandaceae, is rich in polysaccharides, flavonoids, and terpenoids. It has important pharmacological effects such as lowering blood lipids, blood sugar, and blood pressure. However, little has been discerned regarding anti tumor effects and their potential mechanisms. Method: In vitro cell culture experiments were used to test the effect of C. paliurus total flavonoids (CTFs) extract on apoptosis mechanisms in HepG2 cells. Network pharmacology was applied to further explore the effects of CTFs on liver cancer as well as the mechanisms through which these effects might be achieved. Both 3 hydroxyflavone and luteolin were randomly selected to verify the effect on inducing apoptosis and inhibiting the proliferation of HepG2 cells. Results and Discussion: Network pharmacological analysis was applied to these 62 compounds and their targets, and 13 flavonoids were further screened for their potential anti liver cancer activity. These 13 flavonoids included: tangeretin, baicalein, 7,3'-dihydroxyflavone, velutin, 3-hydroxyflavone, chrysin, kumatakenin, tricin, luteolin, chrysoeriol, apigenin, pinocembrin, and butin. Together, these flavonoids were predicted to interact with AKT1, MAPK3, PIK3CA, EGFR, MAP2K1, SRC, IGF1R, IKBKB, MET, and MAPK14. It was predicted that the inhibitory effect on hepatocellular carcinoma would be accomplished by regulation of core proteins relating to such KEGG pathways as cancer, PI3K-Akt, proteoglycans in cancer, microRNAs in cancer, and endocrine resistance via core target proteins. Both 3-hydroxyflavone and luteolin were demonstrated to induce apoptosis and inhibit the proliferation of HepG2 cells. Our study provides scientific evidence supporting the use of CTFs for the treatment of liver cancer.

An ultra-performance LC-MS/MS method for determination of JRF103 in human plasma: application in first-in-patient study

Background: JRF103, a novel pan-HER inhibitor, has shown potent activity against HER1, HER2, HER4 and EGFR in vitro. To support its first-in-patient trial, a sensitive and rapid method was developed and validated using ultra-performance LC-MS/MS. Materials & methods: JRF103 was extracted from plasma using protein precipitation. Extracts were subjected to ultra-performance LC-MS/MS with electrospray ionization. Results: Separation of analyte was achieved using a 1.7-μm C₁₈ column (2.1 × 50-mm internal diameter) with a gradient elution. The developed method was fully validated following the international guides. Conclusion: The developed method was sensitive, specific and suitable for measuring JRF103 concentration in patients with advanced solid tumors in the first-in-patient study of JRF103.

Effect of cholesterol-lowering agents on soluble epidermal growth factor receptor level in type 2 diabetes and hypercholesterolemia

Soluble epidermal growth factor receptor (sEGFR) levels are elevated in patients with type 2 diabetes mellitus (T2DM) and positively correlate with blood glucose and cholesterol levels. However, how cholesterol-lowering treatment in patients with T2DM affects the sEGFR level is unknown. Therefore, we investigated the change of serum sEGFR after cholesterol-lowering treatment in type 2 diabetic patients with hypercholesterolemia. This study is a non-randomized, prospective observational study. A total of 115 patients were treated in either the rosuvastatin monotherapy group (R group, 5 mg/day, n = 59) or the rosuvastatin/ezetimibe combination therapy group (RE group, 5 mg/10 mg/day, n = 56) for 12 weeks. We measured serum levels of lipids and sEGFR using an ELISA kit before and after 12 weeks of treatment in each group. The low-density lipoprotein cholesterol (LDL-C) level was significantly reduced (from 130.27 ± 27.09 to 76.24 ± 26.82 mg/dL; P < .001) after 12 weeks of treatment and more so in the RE group than in the R group (from 131.68 ± 28.72 to 87.13 ± 27.04 mg/dL, P < .001 in the R group; from 128.78 ± 25.58 to 64.75 ± 21.52 mg/dL, P < .001 in the RE group; R vs RE group, P < .001). The sEGFR level was significantly decreased after 12 weeks of treatment (from 50.34 ± 13.31 to 45.75 ± 11.54 ng/mL; P = .007). The RE group only showed a significant reduction in the sEGFR level after treatment (from 50.94 ± 12.10 to 44.80 ± 11.36 ng/mL; P = .007). Moreover, the sEGFR level was significantly reduced only when the LDL-C level was significantly reduced (from 50.46 ± 10.66 to 46.24 ± 11.86 ng/mL; P = .043). The serum sEGFR level was significantly reduced by cholesterol-lowering treatment with rosuvastatin alone or rosuvastatin/ezetimibe. We suggested that sEGFR may play a significant role in insulin resistance (IR) and inflammation, which are central pathophysiological mechanisms. We confirmed the possibility of using sEGFR as a biomarker to predict a good response to lipid-lowering treatment in type 2 diabetes patients with hypercholesterolemia.

Exosomes at the crossroad between therapeutic targets and therapy resistance in head and neck squamous cell carcinoma

Head and neck squamous cell carcinomas (HNSCCs) are aggressive and clinically challenging tumours that require a multidisciplinary management approach. Despite significant therapy improvements, HNSCC patients have a poor prognosis with a 5-year survival rate of about 65%. As recently recognised key players in cancer, exosomes are extracellular vesicles (EVs) with a diameter of nearly 50-120 nm which transport information from one cell to another. Exosomes are actively involved in various aspects of tumour initiation, development, metastasis, immune regulation, therapy resistance, and therapeutic applications. However, current knowledge of the role of exosomes in the pathophysiological processes of HNSCC is still in its infancy, and additional studies are needed. In this review, we summarise and discuss the relevance of exosomes in mediating local immunosuppression and therapy resistance of HNSCC. We also review the most recent studies that have explored the therapeutic potential of exosomes as cancer vaccines, drug carriers or tools to reverse the drug resistance of HNSCC.

Multimodal targeting of glioma with functionalized nanoparticles

The most common and aggressive primitive intracranial tumor of the central nervous system is the glioma. The blood–brain barrier (BBB) has proven to be a significant obstacle to the effective treatment of glioma. To effectively treat glioma, different ways have been used to cross the BBB to deliver drugs to the brain. Drug delivery through nanocarriers proves to be an effective and non-invasive technique for the treatment of glioma and has great potential in the treatment of glioma. In this review, we will provide an overview of nanocarrier-mediated drug delivery and related glioma therapy. Nanocarrier-mediated drug delivery techniques to cross the BBB (liposomes, micelles, inorganic systems, polymeric nanoparticles, nanogel system, and biomimetic nanoparticles) are explored. Finally, the use of nanotherapeutic approaches in the treatment of glioblastoma including chemotherapy, radiotherapy, photothermal therapy, gene therapy, glioma genome editing, immunotherapy, chimeric antigen receptor (CAR) T-cells, immune checkpoint modulators, immune photothermal therapy, vaccine-based immunotherapy, and combination therapy is summarized. Furthermore, this article offers various views on the clinical applicability of nanomedicine.

Identification of EGFR as a Biomarker in Saliva and Buccal Cells from Oral Submucous Fibrosis Patients—A Baseline Study

Oral Submucous Fibrosis (OSMF) is a chronic debilitating disease more frequently encountered in the South-East Asian population. This disease represents a public health priority as it is grouped within oral potentially malignant disorders, with malignant transformation rates of around 7–19%. Hence, early identification of high-risk OSMF patients is of the utmost importance to prevent malignant transformation. Among various biomarkers, EGFR overexpression has an unfavorable clinical outcome, poor prognosis, and low survival rates in Oral Squamous Cell Carcinoma (OSCC). The current study aimed to evaluate the expression of EGFR in saliva and exfoliated buccal cells of OSMF. Immunoexpression of EGFR was observed in healthy controls (n = 11), OSCC (n = 106), and OPMD with dysplasia (n = 56), which showed significant expression with increasing grades of dysplasia and OSCC. EGFR expression was evaluated in saliva and exfoliated buccal cells of healthy controls (n = 15), OSMF (n = 24), and OSCC (n = 10) patients using ELISA, which revealed significant expression in OSMF and OSCC. Validation studies were also performed using real-time PCR (RT-PCR) to compare gene expression in healthy controls (n = 9), OSMF (n = 9), and OSCC (n = 25), which showed significant 18-fold upregulation in OSCC and three-fold upregulation in OSMF when compared to healthy controls. Hence, saliva and exfoliated buccal cells could be considered as potential non-invasive diagnostic samples for the evaluation of high-risk patients of OSMF using EGFR as a biomarker.

A recombinant scFv antibody-based fusion protein that targets EGFR associated with IMPDH2 downregulation and its drug conjugate show therapeutic efficacy against esophageal cancer

The present study aimed to evaluate the anti-tumor efficacy of the epidermal growth factor receptor (EGFR)-targeting recombinant fusion protein Fv-LDP-D3 and its antibody-drug conjugate Fv-LDP-D3-AE against esophageal cancer. Fv-LDP-D3, consisting of the fragment variable (Fv) of an anti-EGFR antibody, the apoprotein of lidamycin (LDP), and the third domain of human serum albumin (D3), exhibited a high binding affinity for EGFR-overexpressing esophageal cancer cells, inhibited EGFR phosphorylation and down-regulated inosine monophosphate dehydrogenase type II (IMPDH2) expression. Fv-LDP-D3 was taken up by cancer cells through intensive macropinocytosis; it inhibited the proliferation and induced the apoptosis of esophageal cancer cells. In vivo imaging revealed that Fv-LDP-D3 displayed specific tumor-site accumulation and a long-lasting retention over a 26-day period. Furthermore, Fv-LDP-D3-AE, a pertinent antibody-drug conjugate prepared by integrating the enediyne chromophore of lidamycin into the Fv-LDP-D3 molecule, displayed highly potent cytotoxicity, inhibited migration and invasion, induced apoptosis and DNA damage, arrested cells at G2/M phase, and caused mitochondrial damage in esophageal cancer cells. More importantly, both of Fv-LDP-D3 and Fv-LDP-D3-AE markedly inhibited the growth of esophageal cancer xenografts in athymic mice at well tolerated doses. The present results indicate that Fv-LDP-D3, and Fv-LDP-D3-AE exert prominent antitumor efficacy associated with targeting EGFR, suggesting their potential as promising candidates for targeted therapy against esophageal cancer.

Combinatorial cetuximab targeted polymeric nanocomplexes reduce PRC1 level and abrogate growth of metastatic hepatocellular carcinoma in vivo with efficient radionuclide uptake

Hepatocellular carcinoma (HCC) is the most aggressive form of cancer with poor drug responses. Developing an effective drug treatment remains a major unmet clinical need for HCC. We report a comprehensive study of combinatorial Cetuximab (Cet) targeted polymeric poly(D, L-lactide-co-glycolide)-b-poly(ethylene glycol) nanocomplexes delivery of Combretastatin A4 (CA4) and 2-Methoxyestradiol (2ME) (Cet-PLGA-b-PEG-CA4 NP + Cet-PLGA-b-PEG-2ME NP) against metastatic HCC in SCID mice. ¹²⁵I-Cet-PLGA-b-PEG NP showed potent accumulation and retention in HCC tumors with longer circulation time up to 48 h (18 ± 1.0% ID/g, P < .0001). Combinatorial treatment with targeted polymeric nanocomplexes presented significant tumor growth inhibition (85%, P < .0001) than the free drug combinatorial counterpart, effectively inhibited orthotopic HCC and prevented lung metastasis. Combinatorial nanocomplexes treatment significantly blocked PRC1, a novel target of therapeutic response against HCC. Thus, the combinatorial cetuximab-targeted polymeric nanocomplexes possess superior antitumor activity against metastatic HCC and provide supports for the clinical translation ahead.

Advances and challenges in the treatment of esophageal cancer

Esophageal cancer (EC) is one of the most common cancers with high morbidity and mortality rates. EC includes two histological subtypes, namely esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). ESCC primarily occurs in East Asia, whereas EAC occurs in Western countries. The currently available treatment strategies for EC include surgery, chemotherapy, radiation therapy, molecular targeted therapy, and combinations thereof. However, the prognosis remains poor, and the overall five-year survival rate is very low. Therefore, achieving the goal of effective treatment remains challenging. In this review, we discuss the latest developments in chemotherapy and molecular targeted therapy for EC, and comprehensively analyze the application prospects and existing problems of immunotherapy. Collectively, this review aims to provide a better understanding of the currently available drugs through in-depth analysis, promote the development of new therapeutic agents, and eventually improve the treatment outcomes of patients with EC.

Intracholecystic papillary neoplasm of the gallbladder diagnosed during follow-up of Menetrier's disease: A case report

Intracholecystic papillary neoplasm of the gallbladder (ICPN) is a type of intraductal papillary neoplasm of the bile duct that occurs in the gallbladder, and is a relatively newer concept. Therefore, there are few reports regarding ICPN. Menetrier's disease is a rare disease characterized by giant hypertrophy of the gastric folds that causes protein-losing gastroenteropathy (PLG). Although Menetrier's disease is a known risk factor for gastric adenocarcinoma, the association between Menetrier's disease and malignancy other than a malignancy of the stomach is unclear. A 69-year-old man presented to the Hokkaido Social Work Association Obihiro Hospital with gallbladder tumours diagnosed by ultrasonography at a previous institution. In addition, he had previously been diagnosed with PLG due to Menetrier's disease. Abdominal contrast-enhanced computed tomography (CT) revealed an irregular mass with a contrast effect at the fundus of the gallbladder on the free abdominal cavity side. Positron emission tomography-CT showed a tumour with a standard uptake value (SUV) of 8.28 at the fundus of the gallbladder. Cholecystectomy and resection of the gallbladder bed were performed. Based on the microscopy findings, the patient was diagnosed with ICPN. Although he had postoperative ileus, he was discharged 14 days postoperatively due to improvement through conservative treatment. Such cases of ICPN complicated with Menetrier's disease are extremely rare. However, patients with Menetrier's disease may need to be screened for malignancies.

The Impact of Long-Term Antibiotic Therapy of Cutaneous Adverse Reactions to EGFR Inhibitors in Colorectal Cancer Patients

Colorectal cancer (CRC) is an important public health issue, in terms of incidence and mortality, with approximately 1.8 million new cases reported worldwide in 2018. Advancements in understanding pathophysiological key steps in CRC tumorigenesis have led to the development of new targeted therapies such as those based on epidermal growth factor receptor inhibitors (EGFR inhibitors). The cutaneous adverse reactions induced by EGFR inhibitors, particularly papulopustular rash, often require long-term antibiotic treatment with tetracycline agents (mostly minocycline and doxycycline). However, this raises several issues of concern: possible occurrence of gut dysbiosis in already vulnerable CRC patients, selection of highly antibiotic resistant and/or virulent clones, development of adverse reactions related to tetracyclines, interference of antibiotics with the response to oncologic therapy, with a negative impact on disease prognosis etc. In the context of scarce information regarding these issues and controversial opinions regarding the role of tetracyclines in patients under EGFR inhibitors, our aim was to perform a thorough literature review and discuss the main challenges raised by long-term use of tetracyclines in advanced CRC patients receiving this targeted therapy.

Nanomedicines functionalized with anti-EGFR ligands for active targeting in cancer therapy: Biological strategy, design and quality control

Recently, active targeting using nanocarriers with biological ligands has emerged as a novel strategy for improving the delivery of therapeutic and/or imaging agents to tumor cells. The presence of active targeting moieties on the surface of nanomedicines has been shown to play an important role in enhancing their accumulation in tumoral cells and tissues versus healthy ones. This property not only helps to increase the therapeutic index but also to minimize possible side effects of the designed nanocarriers. Since the overexpression of epidermal growth factor receptors (EGFR) is a common occurrence linked to the progression of a broad variety of cancers, the potential application of anti-EGFR immunotherapy and EGFR-targeting ligands in active targeting nanomedicines is getting increasing attention. Henceforth, the EGFR-targeted nanomedicines were extensively studied in vitro and in vivo but exhibited both satisfactory and disappointing results, depending on used protocols. This review is designed to give an overview of a variety of EGFR-targeting ligands available for nanomedicines, how to conjugate them onto the surface of nanoparticles, and the main analytical methods to confirm this successful conjugation.

Nanomedicine to Overcome Multidrug Resistance Mechanisms in Colon and Pancreatic Cancer: Recent Progress

The development of drug resistance is one of the main causes of cancer treatment failure. This phenomenon occurs very frequently in different types of cancer, including colon and pancreatic cancers. However, the underlying molecular mechanisms are not fully understood. In recent years, nanomedicine has improved the delivery and efficacy of drugs, and has decreased their side effects. In addition, it has allowed to design drugs capable of avoiding certain resistance mechanisms of tumors. In this article, we review the main resistance mechanisms in colon and pancreatic cancers, along with the most relevant strategies offered by nanodrugs to overcome this obstacle. These strategies include the inhibition of efflux pumps, the use of specific targets, the development of nanomedicines affecting the environment of cancer-specific tissues, the modulation of DNA repair mechanisms or RNA (miRNA), and specific approaches to damage cancer stem cells, among others. This review aims to illustrate how advanced nanoformulations, including polymeric conjugates, micelles, dendrimers, liposomes, metallic and carbon-based nanoparticles, are allowing to overcome one of the main limitations in the treatment of colon and pancreatic cancers. The future development of nanomedicine opens new horizons for cancer treatment.

Cucurbitacin IIb induces apoptosis and cell cycle arrest through regulating EGFR/MAPK pathway

Epidermal growth factor receptor (EGFR) is considered as a valid target in the clinical trials of anticancer therapy and tyrosine kinase inhibitors (TKIs) of EGFR are approved for cancer treatments. In present work, cucurbitacin IIb (CuIIb) was confirmed to exhibit the proliferation inhibitory activity in A549 cells. CuIIb induced apoptosis via STAT3 pathway, which was mitochondria-mediated and caspase-dependent. CuIIb also suppressed the cell cycle and induced G2/M phase cell cycle arrest. CuIIb was capable of suppressing the signal transmitting of the EGFR/mitogen-activated protein kinase (MAPK) pathway which was responsible for the apoptosis and cell cycle arrest. Homogeneous time-resolved fluorescence (HTRF) analysis demonstrated that the kinase activity of EGFR was inhibited by CuIIb. Molecular docking suggested that the CuIIb-EGFR binding fundamentally depends on the contribution of both hydrophobic and hydrogen-bonding interactions. Hence CuIIb may serve as a potential EGFR TKI.

C-demethylation and 1, 2-amino shift in (E)-2-(1-(3-aminophenyl) ethylidene)hydrazinecarboxamide to (E)-2-(2-aminobenzylidene)hydrazinecarboxamide and their applications

A Novel (E)-2-(1-(3-aminophenyl)ethylidene)hydrazinecarboxamide 1 was synthesized by traditional method and converted to (E)-2-(2-aminobenzylidene)hydrazinecarboxamide 2 by single step in DMSO at room temperature. Synthesized compound 1 was analysed by spectroscopy (NMR and LC–MS) techniques and molecule 2 was characterized using single crystal X-ray diffraction and spectroscopy (NMR and GC–MS) techniques. These analytical technique results revealed that, C-demethylation and 1, 2 amino shift in phenyl ring of compound 1 gives molecule 2. DNA binding studies of compounds 1 and 2 was carried out by electronic absorption spectroscopy. This result revealed that, compounds 1 and 2 showed hyperchromism with bathochromic shift. Anticancer activity of compounds 1 and 2 is carried out by molecular docking with five receptors.Computer aided virtual screening demonstrated that the synthesized molecules possess ideal drug likeliness, pharmacokinetics features, toxicity profile for structure based drug discovery. The molecular docking studies revealed that the synthesized molecules are significant binding with the five selected cancer receptors with minimum binding energy (kcal/mol), number of hydrogen bonds, weak interaction, docking score and cluster RMS. The docking studies also suggested that the molecules showed interactions with DNA and the theoretical values of the binding are comparable with that of the experimental values. Hirshfeld surface analysis was used to analyze and quantify the intermolecular interactions in the crystal structure of compound 2.

Measurement of Serum EGFR mRNA Expression is a Reliable Predictor of Treatment Response and Survival Outcomes in Non- Small Cell Lung Cancer

Background:

EGFR over-expression plays a key role in the development and progression of lung cancer. However, its status as a prognostic biomarker for survival outcomes is unclear.

Objectives:

To evaluate the prognostic utility of serum EGFR mRNA expression in Non-Small cell lung cancer (NSCLC) for treatment response and survival.

Methods:

EGFR mRNA levels were determined in serum using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Based on ROC curve, a cut off value of 16.0-fold increase was selected to categorize patients into low EGFR (≤ 16.0) and high EGFR (> 16.0) groups.

Results:

A total of 350 subjects were included (78.3% males), with mean (± SD) age of 57.1 (± 11.2) years, and including 247 (70.6%) adenocarcinoma (ADC). Majority (73.1%) had metastatic (stage IV) disease. Patients had higher pre-treatment serum EGFR mRNA levels than controls [median fold-increase (min, max), 16.2 (1.9, 66.7). Serum EGFR mRNA levels significantly reduced in those who achieved objective response and disease control. Significantly longer OS and PFS was observed in subjects having baseline EGFR mRNA expression ≤ 16.0 fold- increase compared to those with > 16.0 fold- increase [median (95% CI) OS: 25.0 (14.9, NR) versus 7.7 (6.3, 8.9) months; HR (95% CI) 2.9 (2.3, 4.0), p< 0.001; and PFS: 9.9 (7.1, 11.5) versus 6.0 (4.1, 7.5) months; HR (95% CI) 1.8 (1.3, 2.4), p< 0.001].

Conclusion:

Serum EGFR mRNA expression is a useful parameter for predicting treatment response and survival outcomes in NSCLC.

Phase 2 study of cetuximab (Erbitux) in patients with progressive or recurrent endometrial cancer

INTRODUCTION

Overexpression of the epidermal growth factor receptor (EGFR) found in common subtypes of endometrial cancer has been associated with advanced stage disease and a poor prognosis. The purpose of this phase 2 study was to evaluate the efficacy and safety of cetuximab in patients with recurrent endometrial cancer.

METHODS

The study was an open-label phase 2 clinical trial conducted at two institutions. Patients with recurrent or progressive endometrial cancer of any histologic type with the exception of uterine sarcoma received cetuximab at an initial dose of 400 mg/m² IV followed by weekly doses of 250 mg/m². One cycle was considered 4 weeks of treatment. The primary efficacy endpoint was clinical benefit response, defined as a complete or partial response or prolonged stable disease (>8 weeks) by RECIST 1.0 criteria.

RESULTS

A total of 30 patients were enrolled with a median age of 64 years (range 42-83). Of the 20 evaluable patients, three (15%) had clinical benefit response (one complete response, two stable disease). The patient with a clinical benefit response received a total of 27 cycles and the two patients with stable disease were taken off the study due to progression after four and six cycles, respectively. Of the 10 inevaluable patients, nine received ≤1 cycle due to clinical deterioration and one had an anaphylactic reaction. One patient had a grade 3 rash which resolved after a delay in treatment. No dose reduction was reported.

CONCLUSIONS

In this cohort, single agent therapy with cetuximab was well tolerated and had a 15% clinical benefit response. Further studies are required to better identify patients who may respond to this treatment.

Induction of different cellular arrest and molecular responses in low EGFR expressing A549 and high EGFR expressing A431 tumor cells treated with various doses of 177Lu-Nimotuzumab

INTRODUCTION

Radioimmunotherapy (RIT) is a major anti-cancer therapy in cancer management multimodalities. ¹⁷⁷Lu-Nimotuzumab has been in the use for radioimmunotherapy of EGFR expressing tumors. This study focuses on understanding the differential cellular and molecular mechanisms of anti-tumor effects of ¹⁷⁷Lu-Nimotuzumab on low EGFR expressing A549 and high EGFR expressing A431 tumor cells.

MATERIALS AND METHODS

Nimotuzumab labeled with ¹⁷⁷Lu was characterized by SE-HPLC. Specificity of ¹⁷⁷Lu-Nimotuzumab to EGFR expressed on A549 and A431 cells was confirmed by competitive assay using increasing amounts of unlabeled Nimotuzumab. Cellular responses of A549 (low EGFR) and A431 (high EGFR) in response to different doses of ¹⁷⁷Lu-Nimotuzumab were determined by Viable count assay for cellular viability, cell-cycle analysis by DNA staining, apoptotic assay for cell death, and CFSE dilution assay for cellular proliferation capacity. The number of DNA DSBs formed was determined using γ-H2AX assay with PI staining. Transcription of genes involved in DNA damage response and repair (DRR) pathways was monitored by RT-qPCR.

RESULTS

¹⁷⁷Lu-Nimotuzumab characterized by SE-HPLC exhibited a radiochemical purity of 99.1 ± 0.6%. Cell binding competition studies with ¹⁷⁷Lu-Nimotuzumab showed specific binding of 34.3 ± 1.7% with A431 cells and 18.4 ± 1.9% with A549 cells which decreased when co-incubated with unlabeled Nimotuzumab. Cytotoxicity and DNA damage (DNA DSBs) increased with an increase in the dose of ¹⁷⁷Lu-Nimotuzumab. A549 displayed G2/M arrest while A431 showed G1 arrest. Apoptotic death was determined to be one of the modes of death of arrested A549 and A431 cells which increases with the increase in the dose of ¹⁷⁷Lu-Nimotuzumab. Loss of proliferation capacity was higher in A431 showed by CFSE staining at different doses of ¹⁷⁷Lu-Nimotuzumab. Transcription profile of most DRR genes in A431 and A549 showed a decrease in the transcription at 4 h followed by recovery at 16 h post-treatment. The degree of transcription of most DRR genes was similar, irrespective of ¹⁷⁷Lu-Nimotuzumab dose.

CONCLUSION

¹⁷⁷Lu-Nimotuzumab induces different cellular arrest and molecular responses in low EGFR expressing A549 and high EGFR expressing A431 tumor cells. This study would enable the development of integrative novel treatment strategies for radioimmunotherapy in low and high EGFR expressing tumors by ¹⁷⁷Lu-Nimotuzumab with therapeutic gains.

HS2ST1-dependent signaling pathways determine breast cancer cell viability, matrix interactions, and invasive behavior

Heparan sulfate proteoglycans (HSPGs) act as signaling co‐receptors by interaction of their sulfated glycosaminoglycan chains with numerous signaling molecules. In breast cancer, the function of heparan sulfate 2‐O‐sulfotransferase (HS2ST1), the enzyme mediating 2‐O‐sulfation of HS, is largely unknown. Hence, a comparative study on the functional consequences of HS2ST1 overexpression and siRNA knockdown was performed in the breast cancer cell lines MCF‐7 and MDA‐MB‐231. HS2ST1 overexpression inhibited Matrigel invasion, while its knockdown reversed the phenotype. Likewise, cell motility and adhesion to fibronectin and laminin were affected by altered HS2ST1 expression. Phosphokinase array screening revealed a general decrease in signaling via multiple pathways. Fluorescent ligand binding studies revealed altered binding of fibroblast growth factor 2 (FGF‐2) to HS2ST1‐expressing cells compared with control cells. HS2ST1‐overexpressing cells showed reduced MAPK signaling responses to FGF‐2, and altered expression of epidermal growth factor receptor (EGFR), E‐cadherin, Wnt‐7a, and Tcf4. The increased viability of HS2ST1‐depleted cells was reduced to control levels by pharmacological MAPK pathway inhibition. Moreover, MAPK inhibitors generated a phenocopy of the HS2ST1‐dependent delay in scratch wound repair. In conclusion, HS2ST1 modulation of breast cancer cell invasiveness is a compound effect of altered E‐cadherin and EGFR expression, leading to altered signaling via MAPK and additional pathways.

Current Perspectives on 89Zr-PET Imaging

⁸⁹Zr is an emerging radionuclide that plays an essential role in immuno-positron emission tomography (PET) imaging. The long half-life of ⁸⁹Zr (t_1/2 = 3.3 days) is favorable for evaluating the in vivo distribution of monoclonal antibodies. Thus, the use of ⁸⁹Zr is promising for monitoring antibody-based cancer therapies. Immuno-PET combines the sensitivity of PET with the specificity of antibodies. A number of studies have been conducted to investigate the feasibility of ⁸⁹Zr immuno-PET imaging for predicting the efficacy of radioimmunotherapy and antibody therapies, imaging target expression, detecting target-expressing tumors, and the monitoring of anti-cancer chemotherapies. In this review, we summarize the current status of PET imaging using ⁸⁹Zr in both preclinical and clinical studies by highlighting the use of immuno-PET for the targets of high clinical relevance. We also present ⁸⁹Zr-PET applications other than immuno-PET, such as nanoparticle imaging and cell tracking. Finally, we discuss the limitations and the ongoing research being performed to overcome the remaining hurdles.

Regulation of heterogeneous cancer-associated fibroblasts: the molecular pathology of activated signaling pathways

Accumulating evidence indicates that intratumoral heterogeneity contributes to the development of resistance to anticancer therapeutics. Fibroblasts, which are components of the paraneoplastic stroma, play a crucial role in the wound-healing process. Activated fibroblasts accumulate in the wound and are involved in many aspects of the tissue remodeling cascade that initiates the repair process and prevents further tissue damage. The pathophysiological roles of cancer-associated fibroblasts (CAFs) in the heterogeneous tumor microenvironment have attracted increasing interest. CAFs play crucial roles in tumor progression and the response to chemotherapy. Several cytokines and chemokines are involved in the conversion of normal fibroblasts into CAFs, and some of these form a feedback loop between cancer cells and CAFs. In addition, the physical force between tumor cells and CAFs promotes cooperative invasion or co-migration of both types of cells. Pro-inflammatory cytokines, such as leukemia inhibitory factor (LIF) and interleukin-6 (IL-6), are secreted by both cancer cells and CAFs, and mediate the epigenetic modification of CAFs. This enhances the pro-tumorigenic function of CAFs mediated by promoting actomyosin contractility and extracellular matrix remodeling to form the tracks used for collective cancer cell migration. The concept of intra-tumoral CAF heterogeneity refers to the presence of inflammatory CAFs with low levels of α-smooth muscle actin (α-SMA) and high levels of IL-6 expression, which are in striking contrast to transforming growth factor-β (TGF-β)-dependent myofibroblastic CAFs with high α-SMA expression levels. CAF populations that suppress tumor growth and progression through stroma-specific Hedgehog (Hh) activation have been detected in different murine tumor models including those of the bladder, colon, and pancreas. A new therapeutic strategy targeting CAFs is the "stromal switch," in which tumor-promoting CAFs are changed into tumor-retarding CAFs with attenuated stromal stiffness. Several molecular mechanisms that can be exploited to design personalized anticancer therapies targeting CAFs remain to be elucidated. Strategies aimed at targeting the tumor stroma as well as tumor cells themselves have attracted academic attention for their application in precision medicine. This novel review discusses the role of the activation of EGFR, Wnt/β-catenin, Hippo, TGF-β, and JAK/STAT cascades in CAFs in relation to the chemoresistance and invasive/metastatic behavior of cancer cells. For instance, although activated EGFR signaling contributes to collective cell migration in cooperation with CAFs, an activated Hippo pathway is responsible for stromal stiffness resulting in the collapse of neoplastic blood vessels. Therefore, identifying the signaling pathways that are activated under specific conditions is crucial for precision medicine.

CD44v3 protein-carrying tumor-derived exosomes in HNSCC patients' plasma as potential noninvasive biomarkers of disease activity

The molecular cargo of tumor-cell-derived exosomes (TEX) mimics that of parental tumor cells. Thus, TEX could potentially serve as noninvasive biomarkers of cancer progression. However, separation of TEX from non-TEX in patients’ plasma requires tumor antigen-specific detection reagents. CD44v3 has been of interest as a potential biomarker of disease progression in HNSCC, because its overexpression in tumor cells associates with poor outcome. Here, CD44v3+ TEX immunocaptured from plasma of 44 HNSCC patients and 7 healthy donors (HDs) were evaluated as potential biomarkers of disease activity and stage. Exosomes were isolated from plasma of by size exclusion chromatography. Using anti-CD44v3 or anti-CD3 mAbs on beads, CD44v3+ TEX CD3(-)TEX-enriched exosomes were immunocaptured from supernatants of nonmalignant or HNSCC cell lines and from patients’ plasma. On-bead flow cytometry was used for the detection of FAS-L, PD-L1, TGFF-β. CSPG4 or EGFR on exosomes. The TEX expression profiles were correlated to clinicopathological parameters. Relative florescence intensity (RFI) values for CD44v3 were higher (p < .01) on TEX from HNSCC cell lines or on CD44v3+ CD3(-) plasma-derived exosomes. RFI values of CD44v3 on CD3(-) exosomes were higher (p < .005) in patients than in HDs and correlated (p < .05) with the UICC stage and lymph node metastasis. In HNSCC patients, CD44v3+ exosomes higher levels of immunosuppressive proteins compared to CD44v3(-) exosomes (p < .05-p < .005), and RFI values for these markers correlated with higher disease stages and lymph node metastasis. Isolation of CD44v3+ exosomes by immunocapture allowed for enrichment of TEX which are potentially promising liquid biomarkers of the tumor burden and disease stage in HNSCC.

Down-regulation of USP8 Inhibits Cholangiocarcinoma Cell Proliferation and Invasion

Objective

Cholangiocarcinoma is the second most common primary hepatobiliary malignancy with high incidence and recurrence rate. Ubiquitin-specific protease 8 (USP8) is recently reported to be involved in tumor progression. Herein, we aimed to investigate the effects of USP8 on the growth and metastasis abilities of cholangiocarcinoma cells.

Methods

The siRNA interference was used to knock down USP8 in cholangiocarcinoma cell lines QBC939 and RBE; Hucct-1 cells were transfected with pcDNA3.1-USP8 to up-regulate its expression. The effects of USP8 on cholangiocarcinoma were detected by cell function assays. We analyzed the expressions of USP8, Bcl2, Bax, cleaved caspase-3, cleaved caspase-9, Akt, p-Akt, Cyclin D1 and P70S6K by Western blot analysis.

Results

We demonstrated that knockdown of USP8 significantly inhibited the proliferation, migration and invasion of QBC939 and RBE cells in vitro, while USP8 overexpression showed significant promoting effects on Hucct-1 cells. Moreover, silencing of USP8 also promoted apoptosis in cholangiocarcinoma cells by regulating the Bcl-2/Bax axis and Caspase cascade; up-regulation of USP8 decreased apoptosis in Hucct-1 cells. Importantly, knockdown of USP8 inhibited activation of the Akt signaling pathway by decreasing the phosphorylation level of Akt and up-regulated p53 expression, while USP8 overexpression increased activation of the Akt signaling pathway in Hucct-1 cells. Further, IGF-1 could reverse the inhibitory effects of USP8 knockdown on the Akt signaling pathway and the proliferation of QBC939 and RBE cells.

Conclusion

Taken together, our findings suggest that USP8 exerts an oncogenic role in the progression of cholangiocarcinoma and may be a potential therapeutic target for cholangiocarcinoma treatment.

Multifunctional nanomedicines for targeting epidermal growth factor receptor in colorectal cancer

Systemic administration of chemotherapeutics by nanocarriers (NCs) functionalized with targeting agents provides a localized accumulation of drugs in the target tissues and cells. Advanced nanoscaled medicaments can enter into the tumor microenvironment (TME) and overcome the uniquely dysregulated biological settings of TME, including highly pressurized tumor interstitial fluid in an acidic milieu. Such multimodal nanomedicines seem to be one of the most effective treatment modalities against solid tumors such as colorectal cancer (CRC). To progress and invade, cancer cells overexpress various oncogenes and molecular markers such as epidermal growth factor receptors (EGFRs), which can be exploited for targeted delivery of nanoscaled drug delivery systems (DDSs). In fact, to develop effective personalized multimodal nanomedicines, the type of solid tumor and status of the disease in each patient should be taken into consideration. While the development of such multimodal-targeted nanomedicines is largely dependent on the expression level of oncomarkers, the type of NCs and homing/imaging agents play key roles in terms of their efficient applications. In this review, we provide deep insights into the development of EGFR-targeting nanomedicines and discuss various types of nanoscale DDSs (e.g., organic and inorganic nanoparticles) for targeting of the EGFR-positive solid tumors such as CRC.

Evaluation of Nimotuzumab for the treatment of head and neck cancer: Meta-analysis of controlled trials

Nimotuzumab, humanized monoclonal antibody, directed against the epidermal growth factor receptor: highly expressed protein in malignant tumors of epithelial origin. It has been registered for head and neck tumors since 2002. To determine the effectiveness of Nimotuzumab in head and neck cancer through the combined meta-analysis technique. A search was conducted in PubMed, in an indexed magazine with the words “Nimotuzumab”, “head and neck,” 48 articles published by Cuban and foreign authors were detected between April 1, 2005, and July 31, 2019, in which the results of clinical studies conducted with the monoclonal antibody Nimotuzumab are described. Seven clinical trials conducted in Cuba from 2005-2019 with Nimotuzumab are described; three Phase I / II (with 14, 10 and 10 patients respectively), a Phase II / III with 106 patients, a Phase II with 37 patients, two Phase IV (with 386 and 225 patients each) and a study promoted by the Researcher with 17 patients. From these studies, the three controlled trials were selected by the PRISMA flow chart. The meta-analysis consisted of the construction of the Forest Plot graph, the sensitivity analysis and the cumulative analysis. The meta-analysis shows favorable results for Nimotuzumab, without heterogeneity (I2 = 0%). The sensitivity analysis reveals that the test that differs most from the others is Phase II / III. The cumulative analysis indicates that after the second trial, there is already sufficient evidence.

Targeting EGFR and RAS/RAF Signaling in the Treatment of Metastatic Colorectal Cancer: From Current Treatment Strategies to Future Perspectives

The epidermal growth factor receptor (EGFR) and RAS/RAF signaling pathway plays pivotal roles in tumor progression via proliferation, survival, invasion, and immune evasion. Two anti-EGFR monoclonal antibodies, cetuximab and panitumumab, have become essential components in the treatment of patients with metastatic colorectal cancer (mCRC). Treatment with these anti-EGFR antibodies has shown definite benefits when administered in all treatment lines and is strongly recommended as the preferred regimen to prolong survival, especially when administered in the first- and third-lines. Recent efforts have revealed not only mechanisms responsible for resistance to anti-EGFR antibodies, including expanded RAS mutations as a negative predictive biomarker, but also the possibility of continuing anti-EGFR antibody treatment in combination with chemotherapy. Furthermore, the challenges associated with the pharmaceutical development of treatments for patients with mutant-type BRAF mCRC are ongoing. In this review, we provide an overview of the EGFR and RAS/RAF signaling pathway and antitumor activity, focusing on practical aspects such as established treatments including patient selection, treatment strategies, and future perspectives for drug development targeting the EGFR and RAS/RAF signaling pathway.

Single-Cell Analysis of Circulating Tumor Cells: Why Heterogeneity Matters

Unlike bulk-cell analysis, single-cell approaches have the advantage of assessing cellular heterogeneity that governs key aspects of tumor biology. Yet, their applications to circulating tumor cells (CTCs) are relatively limited, due mainly to the technical challenges resulting from extreme rarity of CTCs. Nevertheless, recent advances in microfluidics and immunoaffinity enrichment technologies along with sequencing platforms have fueled studies aiming to enrich, isolate, and sequence whole genomes of CTCs with high fidelity across various malignancies. Here, we review recent single-cell CTC (scCTC) sequencing efforts, and the integrated workflows, that have successfully characterized patient-derived CTCs. We examine how these studies uncover DNA alterations occurring at multiple molecular levels ranging from point mutations to chromosomal rearrangements from a single CTC, and discuss their cellular heterogeneity and clinical consequences. Finally, we highlight emerging strategies to address key challenges currently limiting the translation of these findings to clinical practice.

Aberrant HER3 ligand heregulin-expressing head and neck squamous cell carcinoma is resistant to anti-EGFR antibody cetuximab, but not second-generation EGFR-TKI

The anti-epidermal growth factor receptor (EGFR) antibody cetuximab is standard therapy for head and neck squamous cell carcinoma (HNSCC). However, most HNSCC tumors are resistant to it and require alternative treatments. Here, we explored the mechanism of cetuximab resistance and evaluated its clinical relevance in HNSCC. An unbiased comprehensive transcriptome analysis was performed on cetuximab-resistant HNSCC FaDuCR cells. The causative resistance genome was knocked down with siRNA, cell signaling was immunologically analyzed, and drug efficacy was evaluated in vitro and in vivo. The mRNA in situ hybridization (ISH) of the causative genome was performed using 28 excised HNSCC tumors and its relationship with cetuximab efficacy was analyzed. FaDuCR cells were resistant to cetuximab, whereas parental FaDu cells were susceptible to it. FaDuCR cells expressed consistently higher levels of phosphorylated Akt than FaDu cells despite cetuximab exposure. A comprehensive transcriptome analysis revealed that the HER3-ligand heregulin was upregulated in FaDuCR cells compared to FaDu cells. Heregulin knockdown in FaDuCR cells repressed HER3 and Akt phosphorylation and recovered cetuximab anticancer efficacy. In contrast, pan-HER family tyrosine kinase inhibitors such as afatinib decreased HER3 and Akt phosphorylation in FaDuCR cells and inhibited FaDuCR tumor growth. Two of the 28 HNSCC tumor samples presented aberrant heregulin expression comparable to that of FaDuCR cells and were resistant to cetuximab therapy. In HNSCC, heregulin-mediated HER3-Akt activation causes resistance to cetuximab but not to second-generation EGFR-tyrosine kinase inhibitors. Subpopulations with aberrant heregulin-expressing HNSCC might be resistant to cetuximab.

Anti-EpCAM-conjugated adeno-associated virus serotype 2 for systemic delivery of EGFR shRNA: Its retargeting and antitumor effects on OVCAR3 ovarian cancer in vivo

Adeno-associated virus (AAV) is a promising vector for systemic delivery of siRNA because of its long-term expression ability without immunogenicity and pathogenicity. However, its broad host tropism and lack of tissue specificity have limited clinical applications such as cancer therapy. Therefore, redirecting the natural tropism of AAV vectors to unique cell surface antigens is an important requirement for in vivo RNAi-based cancer therapy. To use the overexpression property of epithelial cell adhesion molecule (EpCAM) in specific cancer types, we herein created anti-EpCAM antibody-conjugated AAV serotype 2 (AAV2) vectors through a streptavidin-biotin bridge. Upon intravenous injection, anti-EpCAM-conjugated AAV2 vectors showed prominent tumor-specific accumulation in EpCAM-positive tumor-bearing mice without undesirable sequestration in liver. In addition, when loaded with transgenes to express shRNA against epidermal growth factor receptor (EGFR), systemically injected anti-EpCAM-conjugated AAV2/shEGFR vectors induced significant downregulation of EGFR expression in tumors and eventually suppressed tumor growth even at the long dosing interval of two weeks. This in vivo antitumor effect represents the increased infection efficacy of tropism-modified AAV2 vectors and prolonged expression of EGFR shRNA in tumor tissues. Thus, this study suggests the great potential of anti-EpCAM-conjugated AAV2/shEGFR vectors as RNAi-based cancer therapeutics. STATEMENT OF SIGNIFICANCE: Adeno-associated virus (AAV) is a promising vector for systemic delivery of siRNA, but its broad host tropism has limited clinical applications. By using the overexpression property of epithelial cell adhesion molecule (EpCAM) on tumors, we demonstrate that anti-EpCAM-conjugated AAV2 vectors through a streptavidin-biotin bridge are redirected to EpCAM-positive tumors in vivo. In addition, when loaded with transgenes to express shRNA against epidermal growth factor receptor (EGFR), systemically injected anti-EpCAM-conjugated AAV2/shEGFR vectors significantly downregulate EGFR expression in tumors, eventually suppressing tumor growth for long periods. We herein suggest the potential of anti-EpCAM-AAV2/shEGFR vectors as an antitumor agent. Furthermore, redirection of AAV2 infection through EpCAM would provide a powerful means for systemic delivery of short hairpin RNA to tumor sites.

Targeted Therapies and Immune-Checkpoint Inhibition in Head and Neck Squamous Cell Carcinoma: Where Do We Stand Today and Where to Go?

With an increased understanding of the tumor biology of squamous cell carcinoma of the head and neck (SCCHN), targeted therapies have found their way into the clinical treatment routines against this entity. Nevertheless, to date platinum-based cytostatic agents remain the first line choice and targeting the epidermal growth factor-receptor (EGFR) with combined cetuximab and radiation therapy remains the only targeted therapy approved in the curative setting. Investigation of immune checkpoint inhibitors (ICI), such as antibodies targeting programmed cell death protein 1 (PD-1) and its ligand PD-L1, resulted in a change of paradigms in oncology and in the first approval of new drugs for treating SCCHN. Nivolumab and pembrolizumab, two anti-PD-1 antibodies, were the first agents shown to improve overall survival for patients with metastatic/recurrent tumors in recent years. Currently, several clinical trials investigate the role of ICI in different therapeutic settings. A robust set of biomarkers will be an inevitable tool for future individualized treatment approaches including radiation dose de-escalation and escalation strategies. This review aims to summarize achieved goals, the current status and future perspectives regarding targeted therapies and ICI in the management of SCCHN.

Analyses of the possible anti-tumor effect of yokukansan

The Kampo medicine yokukansan (YKS) has a wide variety of properties such as anxiolytic, anti-inflammatory and analgesic effects, and is also thought to regulate tumor suppression. In this study, we investigated the anti-tumor effect of YKS. We used Lewis lung carcinoma (LLC)-bearing mice that were fed food pellets containing YKS and then performed a fecal microbiota analysis, a microarray analysis for microRNAs (miRNAs) and an in vitro anti-tumor assay. The fecal microbiota analysis revealed that treatment with YKS partly reversed changes in the microbiota composition due to LLC implantation. Furthermore, a miRNA array analysis using blood serum showed that treatment with YKS restored the levels of miR-133a-3p/133b-3p, miR-1a-3p and miR-342-3p following LLC implantation to normal levels. A TargetScan analysis revealed that the epidermal growth factor receptor 1 signaling pathway is one of the major target pathways for these miRNAs. Furthermore, treatment with YKS restored the levels of miR-200b-3p and miR-200c-3p, a recognized mediator of cancer progression and controller of emotion, in the hypothalamus of mice bearing LLC. An in vitro assay revealed that a mixture of pachymic acid, saikosaponins a and d and isoliquiritigenin, which are all contained in YKS, exerted direct and additive anti-tumor effects. The present findings constitute novel evidence that YKS may exert an anti-tumor effect by reversing changes in the fecal microbiota and miRNAs circulating in the blood serum and hypothalamus, and the compounds found in YKS could have direct and additive anti-tumor effects.

Synthesis of Triazole-Substituted Quinazoline Hybrids for Anticancer Activity and a Lead Compound as the EGFR Blocker and ROS Inducer Agent

A series of triazole-substituted quinazoline hybrid compounds were designed and synthesized for anticancer activity targeting epidermal growth factor receptor (EGFR) tyrosine kinase. Most of the compounds showed moderate to good antiproliferative activity against four cancer cell lines (HepG2, HCT116, MCF-7, and PC-3). Compound 5b showed good antiproliferative activity (IC₅₀ = 20.71 μM) against MCF-7 cell lines. Molecular docking results showed that compound 5b formed hydrogen bond with Met 769 and Lys 721 and π-sulfur interaction with Met 742 of EGFR tyrosine kinase (PDB ID: 1M17). Compound 5b decreases the expression of EGFR and p-EGFR. It also induces apoptosis through reactive oxygen species generation, followed by the change in mitochondrial membrane potential.

Design, synthesis and evaluation of the osimertinib analogue (C-005) as potent EGFR inhibitor against NSCLC

Osimertinib has been approved as a first-line treatment for non-small-cell lung cancer (NSCLC) patients whose tumor carries EGFR activation and / or resistant mutations. To mitigate Osimertinib's toxicity caused by AZ5104, the N-demethylation metabolite of Osimertinib, we designed and synthesized a series of Osimertinib analogs with different headpieces. In vitro and in vivo analysis rendered a potential clinical candidate C-005 which had pyrrolo-pyridine headpiece. Biochemically, C-005 and its main human hepatocyte metabolite showed over 30 fold selectivity of L858R/T790M mutant EGFR over WT EGFR. Such selectivity profile was retained at cellular level. In general, C-005 is 2-14 fold more selective than Osimertinib in a panel of WT EGFR cancer cell lines. Furthermore, C-005 demonstrated robust antitumor efficacy and good tolerability in NCI-H1975, PC-9 and HCC827 xenograft mouse models, making it a potential candidate for human test in clinical.

WNT and NOTCH signaling pathways as activators for epidermal growth factor receptor in esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) is the most common histological type of esophageal cancer, with a poor prognosis. Deregulation of WNT and NOTCH signaling pathways is important in ESCC progression, which can be due to either malfunction of their components or crosstalk with other pathways. Therefore, identification of new crosstalk between such pathways may be effective to introduce new strategies for targeted therapy of cancer. A correlation study was performed to assess the probable interaction between growth factor receptors and WNT/NOTCH pathways via the epidermal growth factor receptor (EGFR) and Musashi1 (MSI1), respectively.

Methods

Levels of MSI1/EGFR mRNA expression in tumor tissues from 48 ESCC patients were compared to their corresponding normal tissues using real-time polymerase chain reaction.

Results

There was a significant correlation between EGFR and MSI1 expression (p = 0.05). Moreover, there was a significant correlation between EGFR/MSI1 expression and grade of tumor differentiation (p = 0.02).

Conclusion

This study confirms a direct correlation between MSI1 and EGFR and may support the important role of MSI1 in activation of EGFR through NOTCH/WNT pathways in ESCC.

A subset of esophageal squamous cell carcinoma patient-derived xenografts respond to cetuximab, which is predicted by high EGFR expression and amplification

Background

Epidermal growth factor receptor (EGFR) is reportedly overexpressed in most esophageal tumors, but most targeted therapies showed no efficacy in non-selected patients. This study aims at investigating the adaptive cetuximab subset in a cohort of esophageal squamous cell carcinoma (ESCC) patient-derived xenografts (PDXs).

Methods

A large panel of ESCC PDXs has been established. The copy number, mRNA expression and immunohistochemistry (IHC) of key EGFR pathways have been examined along with cetuximab response. A preclinical trial on a randomly selected cohort of 16 ESCC PDXs was conducted, and the genomic annotations of these models were compared against the efficacy readout of the mouse trial.

Results

The trial identified that 7 of 16 (43.8%) responded to cetuximab (ΔT/ΔC <0 as responders). The gene amplification and expression analysis indicated that EGFR copy number ≥5 (P=0.035), high EGFR mRNA expression (P=0.001) and IHC score of 2-3 (P=0.034) are associated with tumor growth inhibition by cetuximab, suggesting EGFR may function as a single predictive biomarker for cetuximab response in ESCC.

Conclusions

Overall, our results suggest that an ESCC subtype with EGFR amplification and overexpression benefits from cetuximab treatment, which warrants further clinical confirmation.

Prognostic impact of combined immunoprofiles in oropharyngeal squamous cell carcinoma patients with respect to AJCC 8th edition

OBJECTIVES

To examine combined immunoprofiles of epidermal growth factor receptor (EGFR), CD44, and p16 in oropharyngeal squamous cell carcinoma (OPSCC) and to correlate them with radiotherapy treatment outcomes and clinicopathological parameters. Prognostic impact of the American Joint Committee on Cancer (AJCC) 8th edition staging system in comparison with 7th edition was analyzed.

METHODS

The study included 77 OPSCC patients treated by definitive intensity-modulated radiotherapy (IMRT). Clinical staging was assessed according to the AJCC, both 7th and 8th edition. Immunohistochemical (IHC) analysis of CD44 and EGFR was performed on primary biopsy tumor tissues. To evaluate the HPV status, IHC detection of p16 was employed.

RESULTS

The AJCC 8th edition staging system revealed correlations between overall survival (OS), progression-free survival (PFS), locoregional control (LRC), and clinical stage. EGFR and CD44 positivity (+) and p16 negativity (-) were associated with clinical stage IV of the disease. CD44+ and EGFR+ OPSCC displayed worse OS and LRC, and these cases also showed the worst 3-year OS and LRC. Combined analysis of protein expressions identified an association between p16- and EGFR+, p16- and CD44+, EGFR+, and CD44+. Combined immunoprofiles CD44+/p16-, EGFR+/p16-, and EGFR+/CD44+ were associated with worst OS and LRC.

CONCLUSIONS

Combined immunoprofiles of p16, EGFR, and CD44 might provide valuable prognostic and predictive information for the individual OPSCC patients, especially in terms of response to IMRT and prediction of treatment outcomes. Application of the AJCC 8th edition staging for HPV+ OPSCC proved to improve hazard discrimination and prognostication of OPSCC.