Targeting the epidermal growth factor receptor in epithelial ovarian cancer: current knowledge and future challenges

Developments in Genetics: Better Management of Ovarian Cancer Patients

The purpose of this article is to highlight the new advancements in molecular and diagnostic genetic testing and to properly classify all ovarian cancers. In this article, we address statistics, histopathological classification, molecular pathways implicated in ovarian cancer, genetic screening panels, details about the genes, and also candidate genes. We hope to bring new information to the medical field so as to better prevent and diagnose ovarian cancer.

Liposomal delivery of gene therapy for ovarian cancer: a systematic review

OBJECTIVE

To systematically identify and narratively synthesize the evidence surrounding liposomal delivery of gene therapy and the outcome for ovarian cancer.

METHODS

An electronic database search of the Embase, MEDLINE and Web of Science from inception until July 7, 2023, was conducted to identify primary studies that investigated the effect of liposomal delivery of gene therapy on ovarian cancer outcomes. Retrieved studies were assessed against the eligibility criteria for inclusion.

RESULTS

The search yielded 564 studies, of which 75 met the inclusion criteria. Four major types of liposomes were identified: cationic, neutral, polymer-coated, and ligand-targeted liposomes. The liposome with the most evidence involved cationic liposomes which are characterized by their positively charged phospholipids (n = 37, 49.3%). Similarly, those with neutrally charged phospholipids, such as 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine, were highly researched as well (n = 25, 33.3%). Eight areas of gene therapy research were identified, evaluating either target proteins/transcripts or molecular pathways: microRNAs, ephrin type-A receptor 2 (EphA2), interleukins, mitogen-activated protein kinase (MAPK), human-telomerase reverse transcriptase/E1A (hTERT/EA1), suicide gene, p53, and multidrug resistance mutation 1 (MDR1).

CONCLUSION

Liposomal delivery of gene therapy for ovarian cancer shows promise in many in vivo studies. Emerging polymer-coated and ligand-targeted liposomes have been gaining interest as they have been shown to have more stability and specificity. We found that gene therapy involving microRNAs was the most frequently studied. Overall, liposomal genetic therapy has been shown to reduce tumor size and weight and improve survivability. More research involving the delivery and targets of gene therapy for ovarian cancer may be a promising avenue to improve patient outcomes.

Transient fluid flow improves photoimmunoconjugate delivery and photoimmunotherapy efficacy

Circulating drugs in the peritoneal cavity is an effective strategy for advanced ovarian cancer treatment. Photoimmunotherapy, an emerging modality with potential for the treatment of ovarian cancer, involves near-infrared light activation of antibody-photosensitizer conjugates (photoimmunoconjugates) to generate cytotoxic reactive oxygen species. Here, a microfluidic cell culture model is used to study how fluid flow-induced shear stress affects photoimmunoconjugate delivery to ovarian cancer cells. Photoimmunoconjugates are composed of the antibody, cetuximab, conjugated to the photosensitizer, and benzoporphyrin derivative. Longitudinal tracking of photoimmunoconjugate treatment under flow conditions reveals enhancements in subcellular photosensitizer accumulation. Compared to static conditions, fluid flow-induced shear stress at 0.5 and 1 dyn/cm2 doubled the cellular delivery of photoimmunoconjugates. Fluid flow-mediated treatment with three different photosensitizer formulations (benzoporphyrin derivative, photoimmunoconjugates, and photoimmunoconjugate-coated liposomes) led to enhanced phototoxicity compared to static conditions. This study confirms the fundamental role of fluid flow-induced shear stress in the anti-cancer effects of photoimmunotherapy.

Ligand-installed polymeric nanocarriers for combination chemotherapy of EGFR-positive ovarian cancer

Combination chemotherapeutic drugs administered via a single nanocarrier for cancer treatment provides benefits in reducing dose-limiting toxicities, improving the pharmacokinetic properties of the cargo and achieving spatial-temporal synchronization of drug exposure for maximized synergistic therapeutic effects. In an attempt to develop such a multi-drug carrier, our work focuses on functional multimodal polypeptide-based polymeric nanogels (NGs). Diblock copolymers poly (ethylene glycol)-b-poly (glutamic acid) (PEG-b-PGlu) modified with phenylalanine (Phe) were successfully synthesized and characterized. Self-assembly behavior of the resulting polymers was utilized for the synthesis of NGs with hydrophobic domains in cross-linked polyion cores coated with inert PEG chains. The resulting NGs were small (ca. 70 nm in diameter) and were able to encapsulate the combination of drugs with different physicochemical properties such as cisplatin and neratinib. Drug combination-loaded NGs exerted a selective synergistic cytotoxicity towards EGFR overexpressing ovarian cancer cells. Moreover, we developed ligand-installed EGFR-targeted NGs and tested them as an EGFR-overexpressing tumor-specific delivery system. Both in vitro and in vivo, ligand-installed NGs displayed preferential associations with EGFR (+) tumor cells. Ligand-installed NGs carrying cisplatin and neratinib significantly improved the treatment response of ovarian cancer xenografts. We also confirmed the importance of simultaneous administration of the dual drug combination via a single NG system which provides more therapeutic benefit than individual drug-loaded NGs administered at equivalent doses. This work illustrates the potential of our carrier system to mediate efficient delivery of a drug combination to treat EGFR overexpressing cancers.

Increased endogenous PKG I activity attenuates EGF-induced proliferation and migration of epithelial ovarian cancer via the MAPK/ERK pathway

The type I cGMP-dependent protein kinase (PKG I) is recognized as a tumor suppressor, but its role in EGFR regulated epithelial ovarian cancer (EOC) progression remains unclear. We evaluated the in vivo and in vitro effects of activated PKG I in EGF-induced EOC cell proliferation, migration, and invasion. The expressions of EGFR and PKG I were elevated, but the activated PKG I was decreased in EOC tissues of patients and cells lines. The addition of 8-Br-cGMP, a specific PKG I activator, attenuated the EGF-induced EOC cell proliferation, migration, and invasion in vitro. Similarly, activated PKG I also attenuated EOC progression in vivo using an EOC xenograft nude mouse model. The activated PKG I interacted with EGFR, causing increased threonine (693) phosphorylation and decreased tyrosine (1068) phosphorylation of EGFR, which resulted in disrupted EGFR-SOS1-Grb2 combination. Subsequently, the cytoplasmic phosphorylation of downstream proteins (c-Raf, MEK1/2, and ERK1/2) were declined, impeding the phosphorylated ERK1/2's nucleus translocation, and this reduction of phosphorylated tyrosine (1068) EGFR and ERK1/2 were also abolished by Rp-8-Br-cGMPS. Our results suggest that the activation of PKG I attenuates EGF-induced EOC progression, and the 8-Br-cGMP-PKG I-EGFR/MEK/ERK axis might be a potential target for EOC therapy.

The genetics of monogenic intestinal epithelial disorders

Monogenic intestinal epithelial disorders, also known as congenital diarrheas and enteropathies (CoDEs), are a group of rare diseases that result from mutations in genes that primarily affect intestinal epithelial cell function. Patients with CoDE disorders generally present with infantile-onset diarrhea and poor growth, and often require intensive fluid and nutritional management. CoDE disorders can be classified into several categories that relate to broad areas of epithelial function, structure, and development. The advent of accessible and low-cost genetic sequencing has accelerated discovery in the field with over 45 different genes now associated with CoDE disorders. Despite this increasing knowledge in the causal genetics of disease, the underlying cellular pathophysiology remains incompletely understood for many disorders. Consequently, clinical management options for CoDE disorders are currently limited and there is an urgent need for new and disorder-specific therapies. In this review, we provide a general overview of CoDE disorders, including a historical perspective of the field and relationship to other monogenic disorders of the intestine. We describe the genetics, clinical presentation, and known pathophysiology for specific disorders. Lastly, we describe the major challenges relating to CoDE disorders, briefly outline key areas that need further study, and provide a perspective on the future genetic and therapeutic landscape.

Fentanyl activates ovarian cancer and alleviates chemotherapy-induced toxicity via opioid receptor-dependent activation of EGFR

BACKGROUND

Fentanyl is an opioid analgesic and is widely used in ovarian cancer patients for pain management. Although increasing evidence has suggested the direct role of fentanyl on cancer, little is known on the effect of fentanyl on ovarian cancer cells.

METHODS

Proliferation, migration and apoptosis assays were performed in ovarian cancer cells after fentanyl treatment. Xenograft mouse model was generated to investigate the in vivo efficacy of fentanyl. Combination index was analyzed for the combination of fentanyl and chemotherapeutic drugs. Immunoblotting approach was used to analyze signaling involved in fentanyl's action focusing on EGFR.

RESULTS

Fentanyl at nanomolar concentration does-dependently increased migration and proliferation of a panel of ovarian cancer cell lines. Fentanyl at the same concentrations either did not or stimulated proliferation to a less extent in normal cells than in ovarian cancer cells. Consistently, fentanyl significantly promoted ovarian cancer growth in vivo. The combination of fentanyl with cisplatin or paclitaxel was antagonist in inhibiting cell proliferation. Although fentanyl did not affect cell apoptosis, it significantly alleviated ovarian cancer cell death induced by chemotherapeutic drugs. Mechanistically, fentanyl specifically activated EGFR and its-mediated downstream pathways. Knockdown of EGFR abolished the stimulatory effects of fentanyl on ovarian cancer cells. We finally demonstrated that the activation of EGFR by fentanyl is associated with opioid µ receptor system.

CONCLUSIONS

Fentanyl activates ovarian cancer via simulating EGFR signaling pathways in an opioid µ receptor-dependent manner. The activation of EGFR signaling by fentanyl may provide a new guide in clinical use of fentanyl in ovarian cancer patients.

Applications of Proteomics in Ovarian Cancer: Dawn of a New Era

The ability to identify ovarian cancer (OC) at its earliest stages remains a challenge. The patients present an advanced stage at diagnosis. This heterogeneous disease has distinguishable etiology and molecular biology. Next-generation sequencing changed clinical diagnostic testing, allowing assessment of multiple genes, simultaneously, in a faster and cheaper manner than sequential single gene analysis. Technologies of proteomics, such as mass spectrometry (MS) and protein array analysis, have advanced the dissection of the underlying molecular signaling events and the proteomic characterization of OC. Proteomics analysis of OC, as well as their adaptive responses to therapy, can uncover new therapeutic choices, which can reduce the emergence of drug resistance and potentially improve patient outcomes. There is an urgent need to better understand how the genomic and epigenomic heterogeneity intrinsic to OC is reflected at the protein level, and how this information could potentially lead to prolonged survival.

In Silico and In Vitro Evaluations of Fluorophoric Thiazolo-[2,3-b]quinazolinones as Anti-cancer Agents Targeting EGFR-TKD

Epidermal growth factor receptor tyrosine kinase domain (EGFR-TKD) plays a pivotal role in cellular signaling, growth, and metabolism. The EGFR-TKD is highly expressed in cancer cells and was endorsed as a therapeutic target for cancer management to overcome metastasis, cell proliferation, and angiogenesis. The novel thiazolo-[2,3-b]quinazolinones series were strategically developed by microwave-assisted organic synthesis and multi dominos reactions aimed to identify the potent thiazolo-[2,3-b]quinazolinone inhibitor against EGFR-TKD. This study explores the binding stability and binding strength of newly developed series via molecular docking, molecular dynamics simulation, and MM/PBSA and MM/GBSA calculations. The binding interaction was observed to be through the functional groups on aryl substituents at positions 3 and 5 of the thiazolo-[2, 3-b]quinazolinone scaffold. The methyl substituents at position 8 of the ligands had prominent hydrophobic interactions corroborating their bindings similar to the reference FDA-approved drug erlotinib in the active site. ADMET predictions reveal that derivatives 5ab, 5aq, and 5bq are drug-like and may be effective in in vitro study. Molecular dynamics simulation for 100 ns of docked complexes revealed their stability at the atomistic level. The ΔGbinding of thiazolo-[2,3-b]quinazolinone was found to be 5ab - 22.45, 5aq - 22.23, and 5bq - 20.76 similar to standard drug, and erlotinib - 24.11 kcal/mol was determined by MM/GBSA method. Furthermore, the anti-proliferative activity of leads of thiazolo-[2,3-b]quinazolinones (n = 3) was studied against breast cancer cell line (MCF-7) and non-small lung carcinoma cell line (H-1299). The highest inhibitions in cell proliferation were shown by 5bq derivatives, and the IC₅₀ was found to be 6.5 ± 0.67 µM against MCF-7 and 14.8 µM against H-1299. The noscapine was also taken as a positive control and showed IC₅₀ at higher concentrations 37 ± 1 against MCF-7 and 46.5 ± 1.2 against H-1299.

Biomarkers expression among paired serous ovarian cancer primary lesions and their peritoneal cavity metastases in treatment-naïve patients: A single-center study

Background

High‐grade serous ovarian carcinoma (HGSOC), the most common histologic subtype of ovarian epithelial cancer, is associated with treatment resistance, enhanced recurrence rates, and poor prognosis. HGSOCs often metastasize to the peritoneal cavity, while fluid cytology examination could identify such metastases. This retrospective study aimed to identify potential biomarker discrepancies between paired HGSOC primary tissues and metastatic peritoneal fluid cytology samples, processed as cell blocks (CBs).

Methods

Twenty‐four pairs of formalin‐fixed, paraffin‐embedded primary tissues and metastatic CBs from an equal number of treatment‐naïve patients were used, and immunohistochemistry (IHC) for epidermal growth factor receptor (EGFR), human epidermal growth factor receptor, programmed cell death‐1 ligand 1 (PD‐L1), and CD147 was applied.

Results

13/24 pairs showed discordant EGFR IHC results; in all these 13 patients, EGFR was positive (≥1+ membranous staining intensity found in at least 10% of the cancer cells) in the peritoneal, yet negative in the primary tissue samples. Notably, EGFR IHC was positive in 15/24 of the metastatic, whereas in just 2/24 of the primary HGSOC samples (p < 0.001). Although most PD‐L1 results were concordant, 5/24 and 6/24 pairs exhibited discordant results when stained with the E1L3N and 22C3 clones, respectively. Lastly, CD147 overexpression was found more often in the metastatic rather than the matched primary HGSOCs stained with CD147, though the difference was not significant.

Conclusions

Cytology from effusions could be considered for biomarker testing when present, even when tissue from the primary cancer is also available and adequately cellular, as it could provide additional information of potential clinical significance.

Gain-of-Function Mutant TP53 R248Q Overexpressed in Epithelial Ovarian Carcinoma Alters AKT-Dependent Regulation of Intercellular Trafficking in Responses to EGFR/MDM2 Inhibitor

As the most common gene mutation found in cancers, p53 mutations are detected in up to 96% of high-grade serous ovarian carcinoma (HGSOC). Meanwhile, mutant p53 overexpression is known to drive oncogenic phenotypes in cancer patients and to sustain the activation of EGFR signaling. Previously, we have demonstrated that the combined inhibition of EGFR and MDM2-p53 pathways, by gefitinib and JNJ-26854165, exerts a strong synergistic lethal effect on HGSOC cells. In this study, we investigated whether the gain-of-function p53 mutation (p53^R248Q) overexpression could affect EGFR-related signaling and the corresponding drug inhibition outcome in HGSOC. The targeted inhibition responses of gefitinib and JNJ-26854165, in p53^R248Q-overexpressing cells, were extensively evaluated. We found that the phosphorylation of AKT increased when p53^R248Q was transiently overexpressed. Immunocytochemistry analysis further showed that upon p53^R248Q overexpression, several AKT-related regulatory proteins translocated in unique intracellular patterns. Subsequent analysis revealed that, under the combined inhibition of gefitinib and JNJ-26854165, the cytonuclear trafficking of EGFR and MDM2 was disrupted. Next, we analyzed the gefitinib and JNJ-26854165 responses and found differential sensitivity to the single- or combined-drug inhibitions in p53^R248Q-overexpressing cells. Our findings suggested that the R248Q mutation of p53 in HGSOC caused significant changes in signaling protein function and trafficking, under EGFR/MDM2-targeted inhibition. Such knowledge could help to advance our understanding of the role of mutant p53 in ovarian carcinoma and to improve the prognosis of patients receiving EGFR/MDM2-targeted therapies.

Amphiregulin increases migration and proliferation of epithelial ovarian cancer cells by inducing its own expression via PI3-kinase signaling

The epidermal growth factor receptor (EGFR) is overexpressed in many types of cancer, including epithelial ovarian cancer (EOC), and its expression has been found to correlate with advanced stage and poor prognosis. The EGFR ligand amphiregulin (AREG) has been investigated as a target for human cancer therapy and is known to have an autocrine role in many cancers. A cytokine array identified AREG as one of several cytokines upregulated by EGF in a phosphatidylinositol 3-kinase (PI3-K) dependent manner in EOC cells. To investigate the functional role of AREG in EOC, its effect on cellular migration and proliferation was assessed in two EOC cells lines, OV167 and SKOV3. AREG increased both migration and proliferation of EOC cell line models through activation of PI3-K signaling, but independent of mitogen activated protein kinase (MAPK) signaling. Through an AREG autocrine loop mediated via PI3-K, upregulation of AREG led to increased levels of both AREG transcript and secreted AREG, while downregulation of endogenous AREG decreased the ability of exogenous AREG to induce cell migration and proliferation. Further, inhibition of endogenous AREG activity or metalloproteinase activity decreased EGF-induced EOC migration and proliferation, indicating a role for soluble endogenous AREG in mediating the functional effects of EGFR in inducing migration and proliferation in EOC.

An Overview of Ovarian Cancer: Molecular Processes Involved and Development of Target-based Chemotherapeutics

Ovarian cancer is one of the leading gynecologic diseases with a high mortality rate worldwide. Current statistical studies on cancer reveal that over the past two decades, the fifth most common cause of death related to cancer in females of the western world is ovarian cancer. In spite of significant strides made in genomics, proteomics and radiomics, there has been little progress in transitioning these research advances into effective clinical administration of ovarian cancer. Consequently, researchers have diverted their attention to finding various molecular processes involved in the development of this cancer and how these processes can be exploited to develop potential chemotherapeutics to treat this cancer. The present review gives an overview of these studies which may update the researchers on where we stand and where to go further. The unfortunate situation with ovarian cancer that still exists is that most patients with it do not show any symptoms until the disease has moved to an advanced stage. Undoubtedly, several targets-based drugs have been developed to treat it, but drug-resistance and the recurrence of this disease are still a problem. For the development of potential chemotherapeutics for ovarian cancer, however, some theoretical approaches have also been applied. A description of such methods and their success in this direction is also covered in this review.

p85β alters response to EGFR inhibitor in ovarian cancer through p38 MAPK-mediated regulation of DNA repair

EGFR signaling promotes ovarian cancer tumorigenesis, and high EGFR expression correlates with poor prognosis. However, EGFR inhibitors alone have demonstrated limited clinical benefit for ovarian cancer patients, owing partly to tumor resistance and the lack of predictive biomarkers. Cotargeting EGFR and the PI3K pathway has been previously shown to yield synergistic antitumor effects in ovarian cancer. Therefore, we reasoned that PI3K may affect cellular response to EGFR inhibition. In this study, we revealed PI3K isoform-specific effects on the sensitivity of ovarian cancer cells to the EGFR inhibitor erlotinib. Gene silencing of PIK3CA (p110α) and PIK3CB (p110β) rendered cells more susceptible to erlotinib. In contrast, low expression of PIK3R2 (p85β) was associated with erlotinib resistance. Depletion of PIK3R2, but not PIK3CA or PIK3CB, led to increased DNA damage and reduced level of the nonhomologous end joining DNA repair protein BRD4. Intriguingly, these defects in DNA repair were reversed upon erlotinib treatment, which caused activation and nuclear import of p38 MAPK to promote DNA repair with increased protein levels of 53BP1 and BRD4 and foci formation of 53BP1. Remarkably, inhibition of p38 MAPK or BRD4 re-sensitized PIK3R2-depleted cells to erlotinib. Collectively, these data suggest that p38 MAPK activation and the subsequent DNA repair serve as a resistance mechanism to EGFR inhibitor. Combined inhibition of EGFR and p38 MAPK or DNA repair may maximize the therapeutic potential of EGFR inhibitor in ovarian cancer.

Signaling pathways in cancer-associated fibroblasts and targeted therapy for cancer

To flourish, cancers greatly depend on their surrounding tumor microenvironment (TME), and cancer-associated fibroblasts (CAFs) in TME are critical for cancer occurrence and progression because of their versatile roles in extracellular matrix remodeling, maintenance of stemness, blood vessel formation, modulation of tumor metabolism, immune response, and promotion of cancer cell proliferation, migration, invasion, and therapeutic resistance. CAFs are highly heterogeneous stromal cells and their crosstalk with cancer cells is mediated by a complex and intricate signaling network consisting of transforming growth factor-beta, phosphoinositide 3-kinase/AKT/mammalian target of rapamycin, mitogen-activated protein kinase, Wnt, Janus kinase/signal transducers and activators of transcription, epidermal growth factor receptor, Hippo, and nuclear factor kappa-light-chain-enhancer of activated B cells, etc., signaling pathways. These signals in CAFs exhibit their own special characteristics during the cancer progression and have the potential to be targeted for anticancer therapy. Therefore, a comprehensive understanding of these signaling cascades in interactions between cancer cells and CAFs is necessary to fully realize the pivotal roles of CAFs in cancers. Herein, in this review, we will summarize the enormous amounts of findings on the signals mediating crosstalk of CAFs with cancer cells and its related targets or trials. Further, we hypothesize three potential targeting strategies, including, namely, epithelial-mesenchymal common targets, sequential target perturbation, and crosstalk-directed signaling targets, paving the way for CAF-directed or host cell-directed antitumor therapy.

MUC1 regulates AKT signaling pathway by upregulating EGFR expression in ovarian cancer cells

MUC1, a type I transmembrane glycoprotein, mediates tumor growth and cellular differentiation in various types of cancers. However, the mechanism of MUCI in ovarian cancer has not been fully clarified. In our study, we have observed that MUC1 can play a crucial role in the development and progression of ovarian cancer and act as a predictive marker. We also found that MUC1 could increase the expression of EGFR, and MUC1-EGFR co-administration could promote the cellular growth via the AKT pathway. Taxol is an important drug for treating ovarian cancer, which can prevent cancer recurrence and reduce mortality. Our data have collectively reflected that Taxol can prevent ovarian cancer with abnormal expression of MUC1.

Dual down-regulation of EGFR and ErbB2 by berberine contributes to suppression of migration and invasion of human ovarian cancer cells

The overexpression of EGFR and/or ErbB2 occurs frequently in ovarian cancers and is associated with poor prognosis. The purpose of this study was to examine the anticancer effects and molecular mechanisms of berberine on human ovarian cancer cells with different levels of EGFR and/or ErbB2. We found that berberine reduced the motility and invasiveness of ovarian cancer cells. Berberine depleted both EGFR and ErbB2 in ovarian cancer cells. Furthermore, berberine suppressed the activation of the EGFR and ErbB2 downstream targets cyclin D1, MMPs, and VEGF by down-regulating the EGFR-ErbB2/PI3K/Akt signaling pathway. The berberine-mediated inhibition of MMP-2 and MMP-9 activity could be rescued by co-treatment with EGF. Finally, we demonstrated that berberine induced ErbB2 depletion through ubiquitin-mediated proteasome degradation. In conclusion, the suppressive effects of berberine on the ovarian cancer cells that differ in the expression of EGFR and ErbB2 may be mediated by the dual depletion of EGFR and/or ErbB2.

RTK Inhibitors in Melanoma: From Bench to Bedside

MAPK (mitogen activated protein kinase) and PI3K/AKT (Phosphatidylinositol-3-Kinase and Protein Kinase B) pathways play a key role in melanoma progression and metastasis that are regulated by receptor tyrosine kinases (RTKs). Although RTKs are mutated in a small percentage of melanomas, several receptors were found up regulated/altered in various stages of melanoma initiation, progression, or metastasis. Targeting RTKs remains a significant challenge in melanoma, due to their variable expression across different melanoma stages of progression and among melanoma subtypes that consequently affect response to treatment and disease progression. In this review, we discuss in details the activation mechanism of several key RTKs: type III: c-KIT (mast/stem cell growth factor receptor); type I: EGFR (Epidermal growth factor receptor); type VIII: HGFR (hepatocyte growth factor receptor); type V: VEGFR (Vascular endothelial growth factor), structure variants, the function of their structural domains, and their alteration and its association with melanoma initiation and progression. Furthermore, several RTK inhibitors targeting the same receptor were tested alone or in combination with other therapies, yielding variable responses among different melanoma groups. Here, we classified RTK inhibitors by families and summarized all tested drugs in melanoma indicating the rationale behind the use of these drugs in each melanoma subgroups from preclinical studies to clinical trials with a specific focus on their purpose of treatment, resulted effect, and outcomes.

89Zr-Labeled Domain II-Specific scFv-Fc ImmunoPET Probe for Imaging Epidermal Growth Factor Receptor In Vivo

Simple Summary

Abundance of certain proteins such as epidermal growth factor receptor (EGFR) and their growth factors on cancer cells is in part responsible for their uncontrolled growth. Compounds that selectively bind to such proteins have diagnostic and/or therapeutic implications. EGFR has four binding domains (I-IV). Most anti-EGFR therapeutic antibodies bind to domain III. Compounds that bind to other domains have implications not only for diagnosis but also for monitoring therapy response. We describe the development of a diagnostic agent to be used with positron emission tomography (PET) that binds to domain II of EGFR. We developed ⁸⁹Zr-8709-scFv-Fc antibody PET agent and evaluated its binding characteristics in cancer cells and mouse models. The presence of a domain III-binding antibody such as nimotuzumab did not inhibit the binding of ⁸⁹Zr-8709-scFv-Fc, and vice versa. Therefore, ⁸⁹Zr-8709-scFv-Fc PET/CT can be used for diagnosis and monitoring therapy response in the presence of a domain III-binding agent.

Abstract

Epidermal growth factor receptor I (EGFR) is overexpressed in many cancers. The extracellular domain of EGFR has four binding epitopes (domains I- IV). All clinically approved anti-EGFR antibodies bind to domain III. Imaging agents that bind to domains other than domain III of EGFR are needed for accurate quantification of EGFR, patient selection for anti-EGFR therapeutics and monitoring of response to therapies. We recently developed a domain II-specific antibody fragment 8709. In this study, we have evaluated the in vitro and in vivo properties of ⁸⁹Zr-8709-scFv-Fc (105 kDa). We conjugated 8709-scFv-Fc with the deferoxamine (DFO) chelator and radiolabeled the DFO-8970-scFv with ⁸⁹Zr. We evaluated the binding of ⁸⁹Zr-DFO-8709-scFv-Fc in EGFR positive and negative cell lines DLD-1, MDA-MB-231 and MDA-MB-435, respectively, and in mouse xenograft models. Simultaneously, we have compared the binding of ⁸⁹Zr-8709-scFv-Fc with ¹¹¹In-nimotuzumab, a domain III anti-EGFR antibody. DFO-8709-scFv-Fc displayed similar cell binding specificity as 8709-scFv-Fc. Saturation cell binding assay and immunoreactive fraction showed that radiolabeling did not alter the binding of 8709-scFv-Fc. Biodistribution and microPET showed good uptake of ⁸⁹Zr-8709-scFv-Fc in xenografts after 120 h post injection (p.i). and was domain-specific to EGFR domain II. ⁸⁹Zr-8709-scFv-Fc did not compete for binding in vitro and in vivo with a known domain III binder nimotuzumab. The results show that ⁸⁹Zr-8709-scFv-Fc is specific to domain II of EGFR making it favorable for quantification of EGFR in vivo, hence, patient selection and monitoring of response to treatment with anti-EGFR antibodies.

Lung cancer molecular mutations and abnormal glycosylation as biomarkers for early diagnosis

Lung cancer is the leading cause of mortality and morbidity in tumor-related deaths in the world. Early detection of tumors can greatly improve the survival rate of patients. However, the lack of reliable blood biomarkers remains a major challenge for early diagnosis. The blood proteins secreted by the lung bronchi and bronchial arteries may have characteristic glycosylation patterns associated with tumors, which are different from normal physiological and pathological conditions. In this review, we outline the oncogenic drivers, signaling pathways related to KRAS, gene and protein mutations, and oncogenic regulation of protein glycosylation. Based on to the TCGA transcriptomics and antibody-based proteomics data, we discussed oncogene and glycoproteins detected in the blood as tumor biomarkers. We hypothesize that glycoproteins whose glycosylation can be reversed by targeted drugs may serve as potential tumor biomarkers.

Rose (Rosa gallica) Petal Extract Suppress Proliferation, Migration, and Invasion of Human Lung Adenocarcinoma A549 Cells through via the EGFR Signaling Pathway

We sought to investigate the effect of rose petal extract (RPE) on the proliferation, migration, and invasion of cancer cells. RPE significantly inhibited the growth of lung and colorectal cancer cell lines, with rapid suppression of A549 lung cancer cells at low concentrations. These effects occurred concomitantly with downregulation of the cell proliferation mediators PCNA, cyclin D1, and c-myc. In addition, RPE suppressed the migration and invasion of A549 cells by inhibiting the expression and activity of matrix metalloproteinase-2 and matrix metalloproteinase-9 (MMP-2 and -9). We hypothesize that the suppressive activity of RPE against lung cancer cell proliferation and early metastasis occurs via the EGFR-MAPK and mTOR-Akt signaling pathways. These early results highlight the significant potency of RPE, particularly for lung cancer cells, and warrant further investigation.

Peritoneal Spread of Ovarian Cancer Harbors Therapeutic Vulnerabilities Regulated by FOXM1 and EGFR/ERBB2 Signaling

Peritoneal spread is the primary mechanism of metastasis of ovarian cancer, and survival of ovarian cancer cells in the peritoneal cavity as nonadherent spheroids and their adherence to the mesothelium of distant organs lead to cancer progression, metastasis, and mortality. However, the mechanisms that govern this metastatic process in ovarian cancer cells remain poorly understood. In this study, we cultured ovarian cancer cell lines in adherent and nonadherent conditions in vitro and analyzed changes in mRNA and protein levels to identify mechanisms of tumor cell survival and proliferation in adherent and nonadherent cells. EGFR or ERBB2 upregulated ZEB1 in nonadherent cells, which caused resistance to cell death and increased tumor-initiating capacity. Conversely, Forkhead box M1 (FOXM1) was required for the induction of integrin β1, integrin-α V, and integrin-α 5 for adhesion of cancer cells. FOXM1 also upregulated ZEB1, which could act as a feedback inhibitor of FOXM1, and caused the transition of adherent cells to nonadherent cells. Strikingly, the combinatorial treatment with lapatinib [dual kinase inhibitor of EGFR (ERBB1) and ERBB2] and thiostrepton (FOXM1 inhibitor) reduced growth and peritoneal spread of ovarian cancer cells more effectively than either single-agent treatment in vivo. In conclusion, these results demonstrate that FOXM1 and EGFR/ERBB2 pathways are key points of vulnerability for therapy to disrupt peritoneal spread and adhesion of ovarian cancer cells. SIGNIFICANCE: This study describes the mechanism exhibited by ovarian cancer cells required for adherent cell transition to nonadherent form during peritoneal spread and metastasis. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/24/5554/F1.large.jpg.

Integrative network analysis identifies potential targets and drugs for ovarian cancer

BACKGROUND

Though accounts for 2.5% of all cancers in female, the death rate of ovarian cancer is high, which is the fifth leading cause of cancer death (5% of all cancer death) in female. The 5-year survival rate of ovarian cancer is less than 50%. The oncogenic molecular signaling of ovarian cancer are complicated and remain unclear, and there is a lack of effective targeted therapies for ovarian cancer treatment.

METHODS

In this study, we propose to investigate activated signaling pathways of individual ovarian cancer patients and sub-groups; and identify potential targets and drugs that are able to disrupt the activated signaling pathways. Specifically, we first identify the up-regulated genes of individual cancer patients using Markov chain Monte Carlo (MCMC), and then identify the potential activated transcription factors. After dividing ovarian cancer patients into several sub-groups sharing common transcription factors using K-modes method, we uncover the up-stream signaling pathways of activated transcription factors in each sub-group. Finally, we mapped all FDA approved drugs targeting on the upstream signaling.

RESULTS

The 427 ovarian cancer samples were divided into 3 sub-groups (with 100, 172, 155 samples respectively) based on the activated TFs (with 14, 25, 26 activated TFs respectively). Multiple up-stream signaling pathways, e.g., MYC, WNT, PDGFRA (RTK), PI3K, AKT TP53, and MTOR, are uncovered to activate the discovered TFs. In addition, 66 FDA approved drugs were identified targeting on the uncovered core signaling pathways. Forty-four drugs had been reported in ovarian cancer related reports. The signaling diversity and heterogeneity can be potential therapeutic targets for drug combination discovery.

CONCLUSIONS

The proposed integrative network analysis could uncover potential core signaling pathways, targets and drugs for ovarian cancer treatment.

An Overview of Promising Biomarkers in Cancer Screening and Detection

Applications of biomarkers have been proved in oncology screening, diagnosis, predicting response to treatment as well as monitoring the progress of the disease. Considering the crucial role played by them during different disease stages, it is extremely important to evaluate, validate, and assess them to incorporate them into routine clinical care. In this review, the role of few most promising and successfully used biomarkers in cancer detection, i.e. PD-L1, E-Cadherin, TP53, Exosomes, cfDNA, EGFR, mTOR with regard to their structure, mode of action, and reports signifying their pathological significance, are addressed. Also, an overview of some successfully used biomarkers for cancer medicine has been presented. The study also summarizes biomarker-driven personalized cancer therapy i.e., approved targets and indications, as per the US FDA. The review also highlights the increasingly prominent role of biomarkers in drug development at all stages, with particular reference to clinical trials. The increasing utility of biomarkers in clinical trials is clearly evident from the trend shown, wherein ~55 percent of all oncology clinical trials in 2019 were seen to involve biomarkers, as opposed to ~ 15 percent in 2001, which clearly proves the essence and applicability of biomarkers for synergizing clinical information with tumor progression. Still, there are significant challenges in the implementation of these possibilities with strong evidence in cost-- effective manner.

Advances in Targeted Gene Delivery

Gene therapy has the potential to treat both acquired and inherited genetic diseases. Generally, two types of gene delivery vectors are used - viral vectors and non-viral vectors. Non-viral gene delivery systems have attracted significant interest (e.g. 115 gene therapies approved for clinical trials in 2018; clinicaltrials.gov) due to their lower toxicity, lack of immunogenicity and ease of production compared to viral vectors. To achieve the goal of maximal therapeutic efficacy with minimal adverse effects, the cell-specific targeting of non-viral gene delivery systems has attracted research interest. Targeting through cell surface receptors; the enhanced permeability and retention effect, or pH differences are potential means to target genes to specific organs, tissues, or cells. As for targeting moieties, receptorspecific ligand peptides, antibodies, aptamers and affibodies have been incorporated into synthetic nonviral gene delivery vectors to fulfill the requirement of active targeting. This review provides an overview of different potential targets and targeting moieties to target specific gene delivery systems.

Epidermal Growth Factor Receptor and Its Role in Pancreatic Cancer Treatment Mediated by Nanoparticles

Pancreatic adenocarcinoma (PDAC) is a disease with a high incidence and a dreary prognosis. Its lack of symptomatology and late diagnosis contribute to the dearth and inefficiency of therapeutic schemes. Studies show that overexpressed epidermal growth factor receptor (EGFR) is a common occurrence, linking this to the progression of pancreatic cancer, although the association between its expression and the survival rate is rather controversial. EGFR-targeted therapy has not shown the results expected, leaving at hand more questions than answers; clearly, there is a need for a better understanding of the molecular pathways involved. Nanoparticles have been used in trying to improve the efficacy of antitumor treatment; thus, using EGFR's ligand, EGF, for nanoconjugation, showed promising results in increasing the cellular uptake mechanisms and apoptosis of the targeted cells.

Nuclear action of FGF members in endocrine-related tissues and cancer: Interplay with steroid receptor pathways

Dysregulation of the fibroblast growth factors/fibroblast growth factor receptor (FGF/FGFR) pathway has been implicated in a wide range of human disorders and several members have been localized in the nuclear compartment. Hormone-activated steroid receptors or ligand independent activated receptors form nuclear complexes that activate gene transcription. This review aims to highlight the interplay between the steroid receptor and the FGF/FGFR pathways and focuses on the current knowledge on nuclear action of FGF members in endocrine-related tissues and cancer. The nuclear trafficking and targets of FGF/FGFR members and the available evidence on the interplay with steroid hormones and receptors is described. Finally, the data on aberrant FGF/FGFR signaling is summarized and the nuclear action of FGF members on endocrine resistant breast cancer is highlighted. Identifying the mechanisms underlying FGF-induced endocrine resistance will be important to understand how to efficiently target endocrine-related diseases and even enhance or restore endocrine sensitivity in hormone receptor positive tumors.

Smart Targeting To Improve Cancer Therapeutics

Cancer is the second largest cause of death worldwide with the number of new cancer cases predicted to grow significantly in the next decades. Biotechnology and medicine can and should work hand-in-hand to improve cancer diagnosis and treatment efficacy. However, success has been frequently limited, in particular when treating late-stage solid tumors. There still is the need to develop smart and synergistic therapeutic approaches to achieve the synthesis of strong and effective drugs and delivery systems. Much interest has been paid to the development of smart drug delivery systems (drug-loaded particles) that utilize passive targeting, active targeting, and/or stimulus responsiveness strategies. This review will summarize some main ideas about the effect of each strategy and how the combination of some or all of them has shown to be effective. After a brief introduction of current cancer therapies and their limitations, we describe the biological barriers that nanoparticles need to overcome, followed by presenting different types of drug delivery systems to improve drug accumulation in tumors. Then, we describe cancer cell membrane targets that increase cellular drug uptake through active targeting mechanisms. Stimulus-responsive targeting is also discussed by looking at the intra- and extracellular conditions for specific drug release. We include a significant amount of information summarized in tables and figures on nanoparticle-based therapeutics, PEGylated drugs, different ligands for the design of active-targeted systems, and targeting of different organs. We also discuss some still prevailing fundamental limitations of these approaches, eg, by occlusion of targeting ligands.

Visualization of drug target interactions in the contexts of pathways and networks with ReactomeFIViz

The precision medicine paradigm is centered on therapies targeted to particular molecular entities that will elicit an anticipated and controlled therapeutic response. However, genetic alterations in the drug targets themselves or in genes whose products interact with the targets can affect how well a drug actually works for an individual patient. To better understand the effects of targeted therapies in patients, we need software tools capable of simultaneously visualizing patient-specific variations and drug targets in their biological context. This context can be provided using pathways, which are process-oriented representations of biological reactions, or biological networks, which represent pathway-spanning interactions among genes, proteins, and other biological entities. To address this need, we have recently enhanced the Reactome Cytoscape app, ReactomeFIViz, to assist researchers in visualizing and modeling drug and target interactions. ReactomeFIViz integrates drug-target interaction information with high quality manually curated pathways and a genome-wide human functional interaction network. Both the pathways and the functional interaction network are provided by Reactome, the most comprehensive open source biological pathway knowledgebase. We describe several examples demonstrating the application of these new features to the visualization of drugs in the contexts of pathways and networks. Complementing previous features in ReactomeFIViz, these new features enable researchers to ask focused questions about targeted therapies, such as drug sensitivity for patients with different mutation profiles, using a pathway or network perspective.

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.

Modulation of CD44, EGFR and RAC Pathway Genes (WAVE Complex) in Epithelial Cancers

Cancer hallmarks help in understanding the diversity of various neoplasms. Epithelial cancers play an immense role in the tumor biology through Epithelial-Mesenchymal Transition (EMT) process. Receptor tyrosine kinase, as well as phosphatidyl ionositol-3 kinase pathways, play an important role in the regulation of cell proliferation, survival, and differentiation during EMT. Till date, numerous studies have shown modulation in the expression profile of potential targets like CD44, EGFR, and Rac in epithelial cancers. CD44 interacts with EGFR and recruits other molecules which further activate the Rac pathway intermediates. This review mainly focused on modulation of genes like CD44, EGFR, and Rac pathway intermediates which play a crucial role in the tumor progression, metastasis, proliferation, and invasion characteristics in epithelial cancers with EMT properties. Hence, targeting Rac pathway might be a more strategically relevant approach in treating epithelial cancers.

Th1 cytokines sensitize HER-expressing breast cancer cells to lapatinib

The HER family of receptor tyrosine kinases has been linked to deregulation of growth and proliferation for multiple types of cancer. Members have therefore become thefocus of many drug and immune-based therapy innovations. The targeted anti-cancer agent, lapatinib, is a small molecule inhibitor that directly interferes with EGFR (HER-1)and HER-2 signaling, and indirectly reduces HER-3 signaling, thus suppressing important downstream events. A recently-developed dendritic cell-based vaccine against early breast cancer (ductal carcinoma in situ; DCIS) that generates strong Th1-dominated immunity against HER-2 has induced pathologic complete response in about one-third of immunized individuals. In vitro studies suggested cytokines secreted by Th1 cells could be major contributors to the vaccine effects including induction of apoptosis and suppression of HER expression. With a view toward improving complete response rates, we investigated whether the principle Th1 cytokines (IFN-γ and TNF-α) could act in concert with lapatinib to suppress activity of breast cancer lines in vitro. Lapatinib-sensitive SKBR3, MDA-MB-468 and BT474 cells were incubated with Th1 cytokines, lapatinib, or both. It was found that combined treatment maximized metabolic suppression(Alamar Blue assay), as well as cell death (Trypan Blue) and apoptosis(Annexin V/Propidium Iodide and TMRE staining). Combined drug plus cytokine treatment also maximized suppression of both total and phosphorylated forms of HER-2 and HER-3. Interestingly, when lapatinib resistant lines MDA-MB-453 and JIMT-1 were tested, it was found that the presence of Th1 cytokines appeared to enhance sensitivity for lapatinib-induced metabolic suppression and induction of apoptotic cell death, nearly abrogating drug resistance. These studies provide pre-clinical data suggesting the possibility that targeted drug therapy may be combined with vaccination to enhance anti-cancer effects, and furthermore that robust immunity in the form of secreted Th1 cytokines may have the capacity to mitigate resistance to targeted drugs.

Chemotherapy-induced apoptosis, autophagy and cell cycle arrest are key drivers of synergy in chemo-immunotherapy of epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is the most lethal of all gynecological malignancies in the UK. Recent evidence has shown that there is potential for immunotherapies to be successful in treating this cancer. We have previously shown the effective application of combinations of traditional chemotherapy and CAR (chimeric antigen receptor) T cell immunotherapy in in vitro and in vivo models of EOC. Platinum-based chemotherapy synergizes with ErbB-targeted CAR T cells (named T4), significantly reducing tumor burden in mice. Here, we show that paclitaxel synergizes with T4 as well, and look into the mechanisms behind the effectiveness of chemo-immunotherapy in our system. Impairment of caspase activity using pan-caspase inhibitor Z-VAD reveals this chemotherapy-induced apoptotic pathway as an essential factor in driving synergy. Mannose-6-phosphate receptor-mediated autophagy and the arrest of cell cycle in G2/M are also shown to be induced by chemotherapy and significantly contributing to the synergy. Increased expression of PD-1 on T4 CAR T cells occurred when these were in culture with ovarian tumor cells; on the other hand, EOC cell lines showed increased PD-L1 expression following chemotherapy treatment. These findings provided a rationale to look into testing PD-1 blockade in combination with paclitaxel and T4 immunotherapy. Combination of these three agents in mice resulted in significant reduction of tumor burden, compared to each treatment alone. In conclusion, the mechanism driving synergy in chemo-immunotherapy of EOC is multifactorial. A deeper understanding of such process is needed to better design combination therapies and carefully stratify patients.

Clinical significance of growth factor receptor EGFR and angiogenesis regulator VEGF‑R2 in patients with ovarian cancer at FIGO stages I-II

The aim of the present retrospective cohort study was to investigate the prognostic effect of epidermal growth factor receptor (EGFR) and the angiogenesis regulator vascular endothelial growth factor receptor 2 (VEGF‑R2) on disease-free survival (DFS) rate and recurrent disease, and their association with clinicopathological characteristics in 131 patients with International Federation of Gynecology and Obstetrics (FIGO) stages I-II epithelial ovarian cancer. The techniques of tissue microar-rays and immunohistochemistry were used for the positive detection of the markers. The frequency of positive staining in tumors for EGFR was 24% and for VEGF‑R2 was 77%. Across the cohort, there was a total of 34/131 recurrences (26%) and the 5‑year DFS rate was 68%. In a multivariate logistic regression analysis with recurrent disease as the endpoint, FIGO stage (OR=9.7), type (I/II) of tumor (OR=3.0) and VEGF‑R2 status (OR=0.2) were all found to be independent predictive factors in the cohort of patients (n=131). For patients with non‑serous tumors (n=78), the FIGO stage (OR=76), type (I/II) of tumor (OR=44), EGFR status (OR=0.05) and VEGF‑R2 status (OR=0.008) were all significant and independent predictive factors. On comparing the four subgroups, in terms of concomitant EGFR and VEGF‑R2 status, in a survival analysis, the subgroup of patients (n=21) with concomitant positive expression of EGFR and VEGF‑R2 had a 5‑year DFS rate of 100%. Therefore, the prognostic effect of EGFR and VEGF‑R2 for recurrent disease and survival rates was confirmed by the above findings. Certain results in the present study were not in line with results from previous studies on the prognostic effect of EGFR and VEGF‑R2. An increasing number of preclinical and clinical observations have shown that the process of angiogenesis remains to be fully elucidated. Therefore, one of the challenges for future ovarian cancer investigations is to identify which biomarkers may be used as predictive and prognostic markers.

EGFR Immunoexpression in Malignant Serous and Mucinous Ovarian Tumors

The epithelial growth factor receptor (EGFR) is involved in various stages of cancer growth such as tumor initiation, angiogenesis and metastasis, being an attractive target for oncogenic therapy. The present study aims to evaluate the EGFR expression in 54 cases of serous and mucinous ovarian borderline tumors and carcinomas. EGFR expression was present in more than half of the investigated tumors, more frequently in carcinomas than in borderline tumors, especially in the serous type. The highest values of the final staining score (FSS) were observed only in serous carcinomas in the advanced stages of the disease. As a result of frequent expression of EGFR in ovarian tumors, it is necessary to monitor EGFR inhibitors for ovarian cancer therapy, but probably after establishing more rigorous selection and stratification criteria for patients.

α2,3-sialyltransferase type I regulates migration and peritoneal dissemination of ovarian cancer cells

Epithelial ovarian cancer (EOC) has the highest mortality rate among gynecologic cancers due to advanced stage presentation, peritoneal dissemination, and refractory ascites at diagnosis. We investigated the role of α2,3-sialyltransferase type I (ST3GalI) by analyzing human ovarian cancer datasets and human EOC tissue arrays. We found that high expression of ST3GalI was associated with advanced stage EOC. Transwell migration and cell invasion assays showed that high ST3GalI expression enhanced migration of EOC cells. We also observed that there was a linear relation between ST3GalI expression and epidermal growth factor receptor (EGFR) signaling in EOC patients, and that high ST3GalI expression blocked the effect of EGFR inhibitors. Co-Immunoprecipitation experiments demonstrated that ST3GalI and EGFR were present in the same protein complex. Inhibition of ST3GalI using a competitive inhibitor, Soyasaponin I (SsaI), inhibited tumor cell migration and dissemination in the in vivo mouse model with transplanted MOSEC cells. Further, SsaI synergistically enhanced the anti-tumor effects of EGFR inhibitor on EOC cells. Our study demonstrates that ST3GalI regulates ovarian cancer cell migration and peritoneal dissemination via EGFR signaling. This suggests α2,3-linked sialylation inhibitors in combination with EGFR inhibitors could be effective agents for the treatment of EOC.

Cross-linked hyaluronan gel inhibits the growth and metastasis of ovarian carcinoma

BACKGROUND

The recurrence, metastasis and poor prognosis are important characteristics of ovarian carcinoma (OC), which are associated with exfoliation of cells from the primary tumor and colonization of the cells in pelvic cavity. On the other hand, the life quality of the patients undergoing surgical resection of OC was influenced by postoperative adhesions. Therefore, preventing postoperative implant tumor and adhesion may be effective methods to improve OC treatment. HyaRegen Gel, a cross-linked hyaluronan gel (CHAG), has been widely used as an anti-adhesive agent following pelvic operation in clinic. However, whether it can affect the implantation and growth of OC cells or not is still not clear.

METHODS

Migration and invasion assays were applied to detect the effect of CHAG on migration and invasion of OC cells. Western blotting was performed to detect the phosphorylation/activation of EGFR and ERK, and the expression of PCNA and MMP7. Pull down assay was used to analyze the effect of CHAG on the activation of small G protein Rac1. Nude mice implantation tumor model was applied to observe the effect of CHAG on implantation tumor of OC cells.

RESULTS

The results of in vitro experiments showed that CHAG suppressed both basic and EGF-induced migration and invasion of OC cells, blocked the activation of EGF-initiated EGFR activation, inhibited downstream signal transduction of EGFR, and decreased expression of proliferation and migration/invasion related proteins. Meanwhile, results of in vivo experiments showed that CHAG not only inhibited the formation of implantation tumor of OC cells but also delayed the of the growth of the tumors.

CONCLUSIONS

CHAG inhibited migration, invasion and proliferation of OC cells in vitro, and suppressed development of implantation tumor of OC in vivo. This made it as both anti-tumor and anti-adhesion agents.

Sprouty2 inhibits amphiregulin-induced down-regulation of E-cadherin and cell invasion in human ovarian cancer cells

Similar to Drosophila Sprouty (SPRY), mammalian SPRY proteins inhibit the receptor tyrosine kinase-mediated activation of cellular signaling pathways. SPRY2 expression levels have been shown to be down-regulated in human ovarian cancer, and patients with low SPRY2 expression have significantly poorer survival than those with high SPRY2 expression. In addition, epidermal growth factor receptor (EGFR) is overexpressed in human ovarian cancer and is associated with more aggressive clinical behavior and a poor prognosis. Amphiregulin (AREG), the most abundant EGFR ligand in ovarian cancer, binds exclusively to EGFR and stimulates ovarian cancer cell invasion by down-regulating E-cadherin expression. However, thus far, the roles of SPRY2 in AREG-regulated E-cadherin expression and cell invasion remain unclear. In the present study, we show that treatment with AREG up-regulated SPRY2 expression by activating the EGFR-mediated ERK1/2 signaling pathway in two human ovarian cancer cell lines, SKOV3 and OVCAR5. In addition, overexpression of SPRY2 attenuated the AREG-induced down-regulation of E-cadherin by inhibiting the induction of the E-cadherin transcriptional repressor, Snail. Moreover, SPRY2 overexpression attenuated AREG-stimulated cell invasion and proliferation. This study reveals that SPRY2 acts as a tumor suppressor in human ovarian cancer and illustrates the underlying mechanisms that can be used as possible targets for the development of novel therapeutics.

Combined effects of EGFR and hedgehog signaling blockade on inhibition of head and neck squamous cell carcinoma

Head and neck cancer, the sixth most common cancer, has poor prognosis and short survival. Anti-epidermal growth factor receptor (EGFR) therapies have been recently developed for the treatment of multiple cancer types. JK184, an inhibitor of Hedgehog pathway, prevents the growth of many tumor cell lines in several studies. Whether it enhances chemosensitivity to block EGFR expression by shEGFR plasmid and blocks the Hedgehog pathway by JK184 remains unclear in sinonasal tumors. The changes in cell apoptosis and proteins have been detected by flow cytometry and Western blotting, respectively. In vivo, the maxillary sinus model was established to detect the inhibition of tumor growth and tumor weight. A synergistic effect has been observed with JK184 combined with shEGFR, which is positively correlated with increased autophagy. The maxillary sinus model results demonstrated that the inhibitory rate of the combined therapy was higher than that of JK184 or shEGFR alone. Our findings suggest that JK184 in combination with shEGFR might have potential as a new therapeutic regimen against sinonasal tumors.

EGFR as a prognostic biomarker and therapeutic target in ovarian cancer: evaluation of patient cohort and literature review

Background

Limited effectiveness of therapeutic agents targeting epidermal growth factor receptor (EGFR) in clinical trials using unselected ovarian cancer patients has prompted efforts to more effectively stratify patients who might best benefit from these therapies. A series of studies that have evaluated immunohistochemical (IHC) staining of EGFR in ovarian cancer biopsies has produced unclear results as to the utility of this measure as a prognostic biomarker. Here, we used one of the largest, single institution cohorts to date to determine possible associations of EGFR expression with patient outcome.

Methods

We performed IHC staining of EGFR in tissue microarrays including nearly 500 patient tumor samples. Staining was classified by subcellular localization (membranous, cytoplasmic) or by automated image analysis algorithms. We also performed a literature review to place these results in the context of previous studies.

Results

No significant associations were found between EGFR subcellular localization or expression and histology, stage, grade, or outcome. These results were broadly consistent with the consensus of the reviewed literature.

Conclusions

These results suggest that IHC staining for EGFR may not be a useful prognostic biomarker for ovarian cancer patients. Future studies should pursue other staining methods or analysis in combination with other pathway mediators.

GALNT6 expression enhances aggressive phenotypes of ovarian cancer cells by regulating EGFR activity

Ovarian cancer is the most lethal of the gynecologic malignancies. N-acetylgalactosaminyltransferase 6 (GALNT6), an enzyme that mediates the initial step of mucin type-O glycosylation, has been reported to regulate mammary carcinogenesis. However, the expression and role of GALNT6 in ovarian cancer are still unclear. Here we showed that high GALNT6 expression correlates with increased recurrence, lymph node metastasis, and chemoresistance in ovarian endometrioid and clear cell carcinomas; and higher GALNT6 levels are significantly associated with poorer patient survivals. GALNT6 knockdown with two independent siRNAs significantly suppressed viability, migration, and invasion of ovarian cancer cells. Using phospho-RTK array and Western blot analyses, we identified EGFR as a critical target of GALNT6. GALNT6 knockdown decreased phosphorylation of EGFR, whereas GALNT6 overexpression increased the phosphorylation. Lectin pull-down assays with Vicia villosa agglutinin (VVA) indicated that GALNT6 was able to modify O-glycans on EGFR. Moreover, the GALNT6-enhanced invasive behavior was significantly reversed by erlotinib, an EGFR inhibitor. Our results suggest that GALNT6 expression is associated with poor prognosis of ovarian cancer and enhances the aggressive behavior of ovarian cancer cells by regulating EGFR activity.

Dacomitinib, a pan-inhibitor of ErbB receptors, suppresses growth and invasive capacity of chemoresistant ovarian carcinoma cells

Epithelial ovarian cancer (EOC) is the most lethal gynaecological malignancy worldwide. Development of chemoresistance and peritoneal dissemination of EOC cells are the major reasons for low survival rate. Targeting signal transduction pathways which promote therapy resistance and metastatic dissemination is the key to successful treatment. Members of the ErbB family of receptors are over-expressed in EOC and play key roles in chemoresistance and invasiveness. Despite this, single-targeted ErbB inhibitors have demonstrated limited activity in chemoresistant EOC. In this report, we show that dacomitinib, a pan-ErbB receptor inhibitor, diminished growth, clonogenic potential, anoikis resistance and induced apoptotic cell death in therapy-resistant EOC cells. Dacominitib inhibited PLK1-FOXM1 signalling pathway and its down-stream targets Aurora kinase B and survivin. Moreover, dacomitinib attenuated migration and invasion of the EOC cells and reduced expression of epithelial-to-mesenchymal transition (EMT) markers ZEB1, ZEB2 and CDH2 (which encodes N-cadherin). Conversely, the anti-tumour activity of single-targeted ErbB agents including cetuximab (a ligand-blocking anti-EGFR mAb), transtuzumab (anti-HER2 mAb), H3.105.5 (anti-HER3 mAb) and erlotinib (EGFR small-molecule tyrosine kinase inhibitor) were marginal. Our results provide a rationale for further investigation on the therapeutic potential of dacomitinib in treatment of the chemoresistant EOC.

Clinicopathology of EpCAM and EGFR in Human Epithelial Ovarian Carcinoma

The objective of this study was to explore the expression of EpCAM and EGFR in human epithelial ovarian cancer (EOC) and their correlation with clinicopathological parameters.

The protein expression levels of epithelial cell adhesion molecule (EpCAM) and epidermal growth factor receptor (EGFR) were evaluated by immunohistochemistry in formalin-fixed paraffin-embedded specimens from 30 patients with epithelial ovarian carcinoma and 15 normal ovary tissues. Clinicopathological characteristics were gathered by retrospective review of the patients’ files. The correlation between EpCAM and EGFR expression, as well as their association with clinical pathological parameters were investigated. The SPSS 17.0 package was used to perform statistical analyses.

The positive expression rates of EpCAM and EGFR were significantly elevated in epithelial ovarian cancer tissues than in normal ovary tissues. The positive expressions of EpCAM and EGFR in EOC were associated with International Federation of Gynecology and Obstetrics (FIGO) stage and tumor differentiation, lymph node metastasis. Spearman correlation analysis demonstrated a significant positive association between EpCAM and EGFR expression in EOC.

The co-expression of EpCAM and EGFR may play an important role in the carcinogenesis of EOC and might provide a promising molecular therapeutic target.

Chemoresistance and targeted therapies in ovarian and endometrial cancers

Gynecological cancers are known for being very aggressive at their advanced stages. Indeed, the survival rate of both ovarian and endometrial cancers is very low when diagnosed lately and the success rate of current chemotherapy regimens is not very efficient. One of the main reasons for this low success rate is the acquired chemoresistance of these cancers during their progression. The mechanisms responsible for this acquired chemoresistance are numerous, including efflux pumps, repair mechanisms, survival pathways (PI3K/AKT, MAPK, EGFR, mTOR, estrogen signaling) and tumor suppressors (P53 and Par-4). To overcome these resistances, a new type of therapy has emerged named targeted therapy. The principle of targeted therapy is simple, taking advantage of changes acquired in malignant cancer cells (receptors, proteins, mechanisms) by using compounds specifically targeting these, thus limiting their action on healthy cells. Targeted therapies are emerging and many clinical trials targeting these pathways, frequently involved in chemoresistance, have been tested on gynecological cancers. Despite some targets being less efficient than expected as mono-therapies, the combination of compounds seems to be the promising avenue. For instance, we demonstrate using ChIP-seq analysis that estrogen downregulate tumor suppressor Par-4 in hormone-dependent cells by directly binding to its DNA regulatory elements and inhibiting estrogen signaling could reinstate Par-4 apoptosis-inducing abilities. This review will focus on the chemoresistance mechanisms and the clinical trials of targeted therapies associated with these, specifically for endometrial and ovarian cancers.

NF-κB-Mediated CCL20 Reigns Dominantly in CXCR2-Driven Ovarian Cancer Progression

Ovarian cancer is an inflammation-associated malignancy with a high mortality rate. CXCR2 expressing ovarian cancers are aggressive with poorer outcomes. We previously demonstrated that CXCR2-driven ovarian cancer progression potentiated NF-κB activation through EGFR-transactivated Akt. Here, we identified the chemokine signature involved in CXCR2-driven ovarian cancer progression using a mouse peritoneal xenograft model for ovarian cancer spreading with CXCR2-negative (SKA) and positive (SKCXCR2) cells generated previously from parental SKOV-3 cells. Compared to SKA bearing mice, SKCXCR2 bearing mice had the following characteristics: 1) shorter survival time, 2) greater tumor spreading in the peritoneal cavity and 3) higher tumor weight in the omentum and pelvic site. Particularly, SKCXCR2-derived tumor tissues induced higher activation of the NF-κB signaling pathway, while having no change in EGFR-activated signaling such as Raf, MEK, Akt, mTOR and Erk compared to SKA-derived tumors. Chemokine PCR array revealed that CCL20 mRNA levels were significantly increased in SKCXCR2-derived tumor tissues. The CCL20 promoter activity was regulated by NF-κB dependent pathways. Interestingly, all three κB-like sites in the CCL20 promoter were involved in regulating CCL20 and the proximal region between -92 and -83 was the most critical κB-like site. In addition, SKCXCR2-derived tumor tissues maintained high CCL20 mRNA expression and induced greater CCL24 and CXCR4 compared to SKCXCR2 cells, indicating the shift of chemokine network during the peritoneal spreading of tumor cells via interaction with other cell types in tumor microenvironment. Furthermore, we compared expression profiling array between human ovarian cancer cell lines and tumor tissues based on GEO datasets. The expression profiles in comparison with cell lines revealed that dominant chemokines expressed in ovarian tumor tissues are likely shifted from CXCL1-3 and 8 to CCL20. Taken together, the progression of ovarian cancer in the peritoneal cavity involves NF-κB-mediated CCL20 as a main chemokine network, which is potentiated by CXCR2 expression.

Serine protease inhibitor Kazal type 1 (SPINK1) drives proliferation and anoikis resistance in a subset of ovarian cancers

Ovarian cancer represents the most lethal tumor type among malignancies of the female reproductive system. Overall survival rates remain low. In this study, we identify the serine protease inhibitor Kazal type 1 (SPINK1) as a potential therapeutic target for a subset of ovarian cancers. We show that SPINK1 drives ovarian cancer cell proliferation through activation of epidermal growth factor receptor (EGFR) signaling, and that SPINK1 promotes resistance to anoikis through a distinct mechanism involving protease inhibition. In analyses of ovarian tumor specimens from a Mayo Clinic cohort of 490 patients, we further find that SPINK1 immunostaining represents an independent prognostic factor for poor survival, with the strongest association in patients with nonserous histological tumor subtypes (endometrioid, clear cell, and mucinous). This study provides novel insight into the fundamental processes underlying ovarian cancer progression, and also suggests new avenues for development of molecularly targeted therapies.