Folate receptor in adenocarcinoma and squamous cell carcinoma of the lung: potential target for folate-linked therapeutic agents

Moving beyond traditional therapies: the role of nanomedicines in lung cancer

Amidst a global rise in lung cancer occurrences, conventional therapies continue to pose substantial side effects and possess notable toxicities while lacking specificity. Counteracting this, the incorporation of nanomedicines can notably enhance drug delivery at tumor sites, extend a drug's half-life and mitigate inadvertent toxic and adverse impacts on healthy tissues, substantially influencing lung cancer's early detection and targeted therapy. Numerous studies signal that while the nano-characteristics of lung cancer nanomedicines play a pivotal role, further interplay with immune, photothermal, and genetic factors exist. This review posits that the progression towards multimodal combination therapies could potentially establish an efficacious platform for multimodal targeted lung cancer treatments. Current nanomedicines split into active and passive targeting. Active therapies focus on a single target, often with unsatisfactory results. Yet, developing combination systems targeting multiple sites could chart new paths in lung cancer therapy. Conversely, low drug delivery rates limit passive therapies. Utilizing the EPR effect to bind specific ligands on nanoparticles to tumor cell receptors might create a new regime combining active-passive targeting, potentially elevating the nanomedicines' concentration at target sites. This review collates recent advancements through the lens of nanomedicine's attributes for lung cancer therapeutics, the novel carrier classifications, targeted therapeutic modalities and their mechanisms, proposing that the emergence of multi-target nanocomposite therapeutics, combined active-passive targeting therapies and multimodal combined treatments will pioneer novel approaches and tools for future lung cancer clinical therapies.

Data-Driven Identification of Targets for Fluorescence-Guided Surgery in Non-Small Cell Lung Cancer

PURPOSE

Intraoperative identification of lung tumors can be challenging. Tumor-targeted fluorescence-guided surgery can provide surgeons with a tool for real-time intraoperative tumor detection. This study evaluated cell surface biomarkers, partially selected via data-driven selection software, as potential targets for fluorescence-guided surgery in non-small cell lung cancers: adenocarcinomas (ADC), adenocarcinomas in situ (AIS), and squamous cell carcinomas (SCC).

PROCEDURES

Formalin-fixed paraffin-embedded tissue slides of resection specimens from 15 patients with ADC and 15 patients with SCC were used and compared to healthy tissue. Molecular targets were selected based on two strategies: (1) a data-driven selection using > 275 multi-omics databases, literature, and experimental evidence; and (2) the availability of a fluorescent targeting ligand in advanced stages of clinical development. The selected targets were carbonic anhydrase 9 (CAIX), collagen type XVII alpha 1 chain (collagen XVII), glucose transporter 1 (GLUT1), G protein-coupled receptor 87 (GPR87), transmembrane protease serine 4 (TMPRSS4), carcinoembryonic antigen (CEA), epithelial cell adhesion molecule (EpCAM), folate receptor alpha (FRα), integrin αvβ6 (αvβ6), and urokinase-type plasminogen activator receptor (uPAR). Tumor expression of these targets was assessed by immunohistochemical staining. A total immunostaining score (TIS, range 0-12), combining the percentage and intensity of stained cells, was calculated. The most promising targets in ADC were explored in six AIS tissue slides to explore its potential in non-palpable lesions.

RESULTS

Statistically significant differences in TIS between healthy lung and tumor tissue for ADC samples were found for CEA, EpCAM, FRα, αvβ6, CAIX, collagen XVII, GLUT-1, and TMPRSS4, and of these, CEA, CAIX, and collagen XVII were also found in AIS. For SCC, EpCAM, uPAR, CAIX, collagen XVII, and GLUT-1 were found to be overexpressed.

CONCLUSIONS

EpCAM, CAIX, and Collagen XVII were identified using concomitant use of data-driven selection software and clinical evidence as promising targets for intraoperative fluorescence imaging for both major subtypes of non-small cell lung carcinomas.

Advances in Lung Cancer Treatment Using Nanomedicines

Carcinoma of the lungs is among the most menacing forms of malignancy and has a poor prognosis, with a low overall survival rate due to delayed detection and ineffectiveness of conventional therapy. Therefore, drug delivery strategies that may overcome undesired damage to healthy cells, boost therapeutic efficacy, and act as imaging tools are currently gaining much attention. Advances in material science have resulted in unique nanoscale-based theranostic agents, which provide renewed hope for patients suffering from lung cancer. Nanotechnology has vastly modified and upgraded the existing techniques, focusing primarily on increasing bioavailability and stability of anti-cancer drugs. Nanocarrier-based imaging systems as theranostic tools in the treatment of lung carcinoma have proven to possess considerable benefits, such as early detection and targeted therapeutic delivery for effectively treating lung cancer. Several variants of nano-drug delivery agents have been successfully studied for therapeutic applications, such as liposomes, dendrimers, polymeric nanoparticles, nanoemulsions, carbon nanotubes, gold nanoparticles, magnetic nanoparticles, solid lipid nanoparticles, hydrogels, and micelles. In this Review, we present a comprehensive outline on the various types of overexpressed receptors in lung cancer, as well as the various targeting approaches of nanoparticles.

Investigation of Serum Folate-Receptor-1 Levels in Patients with Non-Small Cell Lung Cancer

Objective: Histopathological overexpression of folate receptor-1 (FOLR1) involved in folate transport in cell growth has been reported in various cancers. Increased serum FOLR1(sFOLR1) has also been reported in epithelial ovarian cancer. The aim was to investigate sFOLR1 levels in non-small cell lung cancer (NSCLC) patients and the response prediction of the standard chemotherapy targeting folic acid metabolism. Method: In this prospective study, sFOLR1 levels were investigated in 30 healthy individuals and 60 patients with stage4 malign metastatic NSCLC before and after standard chemotherapy. The commercial immunoassay (ELISA) kit used for analysis of sFOLR1. Serum carcinoembryonic antigen (CEA), vitamin B12, and folate levels were also investigated. Result: In NSCLC patients sFOLR1 levels were significantly higher(p

Transbronchial real-time lung tumor localization with folate receptor-targeted near-infrared molecular imaging: A proof of concept study in animal models

OBJECTIVE

The diagnostic yield of bronchoscopy is not satisfactory, even with recent navigation technologies, especially for tumors located outside of the bronchial lumen. Our objective was to perform a preclinical assessment of folate receptor-targeted near-infrared imaging-guided bronchoscopy to detect peribronchial tumors.

METHODS

Pafolacianine, a folate receptor-targeted molecular imaging agent, was used as a near-infrared fluorescent imaging agent. An ultra-thin composite optical fiberscope was used for laser irradiation and fluorescence imaging. Subcutaneous xenografts of KB cells in mice were used as folate receptor-positive tumors. Tumor-to-background ratio was calculated by the fluorescence intensity value of muscle tissues acquired by the ultra-thin composite optical fiberscope system and validated using a separate spectral imaging system. Ex vivo swine lungs into which pafolacianine-laden KB tumors were transplanted at various sites were used as a peribronchial tumor model.

RESULTS

With the in vivo murine model, tumor-to-background ratio observed by ultra-thin composite optical fiberscope peaked at 24 hours after pafolacianine injection (tumor-to-background ratio: 2.56 at 0.05 mg/kg, 2.03 at 0.025 mg/kg). The fluorescence intensity ratios between KB tumors and normal mouse lung parenchyma postmortem were 6.09 at 0.05 mg/kg and 5.08 at 0.025 mg/kg. In the peribronchial tumor model, the ultra-thin composite optical fiberscope system could successfully detect fluorescence from pafolacianine-laden folate receptor-positive tumors with 0.05 mg/kg at the carina and those with 0.025 mg/kg and 0.05 mg/kg in the peripheral airway.

CONCLUSIONS

Transbronchial detection of pafolacianine-laden folate receptor-positive tumors by near-infrared imaging was feasible in ex vivo swine lungs. Further in vivo preclinical assessment is needed to confirm the feasibility of this technology.

CD44/Folate Dual Targeting Receptor Reductive Response PLGA-Based Micelles for Cancer Therapy

In this study, a novel poly (lactic-co-glycolic acid) (PLGA)-based micelle was synthesized, which could improve the therapeutic effect of the antitumor drug doxorubicin hydrochloride (DOX) and reduce its toxic and side effects. The efficient delivery of DOX was achieved by active targeting mediated by double receptors and stimulating the reduction potential in tumor cells. FA-HA-SS-PLGA polymer was synthesized by amidation reaction, and then DOX-loaded micelles were prepared by dialysis method. The corresponding surface method was used to optimize the experimental design. DOX/FA-HA-SS-PLGA micelles with high drug loading rate and encapsulation efficiency were prepared. The results of hydrophilic experiment, critical micelle concentration determination, and hemolysis test all showed that DOX/FA-HA-SS-PLGA micelles had good physicochemical properties and biocompatibility. In addition, both in vitro reduction stimulus response experiment and in vitro release experiment showed that DOX/FA-HA-SS-PLGA micelles had reduction sensitivity. Molecular docking experiments showed that it can bind to the target protein. More importantly, in vitro cytology studies, human breast cancer cells (MCF-7), human non-small cell lung cancer cells (A549), and mouse colon cancer cells (CT26) were used to demonstrate that the dual receptor-mediated endocytosis pathway resulted in stronger cytotoxicity to tumor cells and more significant apoptosis. In and in vivo antitumor experiment, tumor-bearing nude mice were used to further confirm that the micelles with double targeting ligands had better antitumor effect and lower toxicity. These experimental results showed that DOX/FA-HA-SS-PLGA micelles have the potential to be used as chemotherapeutic drugs for precise tumor treatment.

Near-Infrared Fluorescence Tumor-Targeted Imaging in Lung Cancer: A Systematic Review

Lung cancer is the most common cancer type worldwide, with non-small cell lung cancer (NSCLC) being the most common subtype. Non-disseminated NSCLC is mainly treated with surgical resection. The intraoperative detection of lung cancer can be challenging, since small and deeply located pulmonary nodules can be invisible under white light. Due to the increasing use of minimally invasive surgical techniques, tactile information is often reduced. Therefore, several intraoperative imaging techniques have been tested to localize pulmonary nodules, of which near-infrared (NIR) fluorescence is an emerging modality. In this systematic review, the available literature on fluorescence imaging of lung cancers is presented, which shows that NIR fluorescence-guided lung surgery has the potential to identify the tumor during surgery, detect additional lesions and prevent tumor-positive resection margins.

Emerging roles for folate receptor FOLR1 in signaling and cancer

Folates are B vitamins that function in one-carbon metabolism. Folate receptors are one of three major types of folate transporters. The folate receptors FOLR1 and FOLR2 are overexpressed in multiple cancers. The overexpression of FOLR1 is often associated with increased cancer progression and poor patient prognosis. There is emerging evidence that FOLR1 is involved in signaling pathways that are independent of one-carbon metabolism. Recent publications implicate a direct role of FOLR1 in three signaling pathways: JAK-STAT3, ERK1/2, and as a transcription factor. Six other signaling pathways have been proposed to include FOLR1, but these currently lack sufficient data to infer a direct signaling role for FOLR1. We discuss the data that support noncanonical roles for FOLR1, and its limitations.

Folate Receptor Alpha Is Preferentially Expressed in the Carcinoma Component of Endometrial Carcinosarcomas: A Potential Target for Adjuvant Therapy

Carcinosarcomas (CSs) of the endometrium are biphasic malignancies, composed of high-grade carcinomatous and sarcomatous components. Surgical stage and pathologic characteristics are the most important prognostic findings, with a 5-yr survival of 15% to 30% in advance stage disease. Folate receptor alpha (FRA) overexpression has been observed in endometrial carcinomas and not yet studied in CSs. This study evaluates semiquantitative expression of FRA in both carcinomatous and sarcomatous components of CSs on whole tissue sections. Immunohistochemistry for FRA expression was performed and extent and intensity of staining were recorded for each case for both histologic components. A total of 46 cases were stained for FRA. The majority of these (40/46, 87%) showed FRA staining at variable intensity in the carcinomatous component, stronger in serous carcinomas and high-grade endometrioid, while only a small subset of tumors demonstrated weak staining in the sarcomatous component (2/46, 4.35%). CS is known to be associated with poor prognosis and adjuvant therapy is recommended even in low stage disease. Serous and high-grade endometrioid carcinomas are the most common carcinomatous components of CSs and are known to show consistently high FRA expression. Folate plays a role in tumor cell migration and loss of cellular adhesion, which are key steps in epithelial-mesenchymal transition, the process by which CS develops from carcinoma cells. Our study shows expression of FRA in the carcinomatous component of almost all CS cases (87%), further favoring FRA as a target for adjuvant treatment. While expression of FRA in the sarcomatous component was rarely observed, the carcinomatous component being associated with metastatic potential underscores the importance of anti-FRA therapy for systemic disease control.

Ligand-mediated delivery of RNAi-based therapeutics for the treatment of oncological diseases

RNA interference (RNAi)-based therapeutics (miRNAs, siRNAs) have great potential for treating various human diseases through their ability to downregulate proteins associated with disease progression. However, the development of RNAi-based therapeutics is limited by lack of safe and specific delivery strategies. A great effort has been made to overcome some of these challenges resulting in development of N-acetylgalactosamine (GalNAc) ligands that are being used for delivery of siRNAs for the treatment of diseases that affect the liver. The successes achieved using GalNAc-siRNAs have paved the way for developing RNAi-based delivery strategies that can target extrahepatic diseases including cancer. This includes targeting survival signals directly in the cancer cells and indirectly through targeting cancer-associated immunosuppressive cells. To achieve targeting specificity, RNAi molecules are being directly conjugated to a targeting ligand or being packaged into a delivery vehicle engineered to overexpress a targeting ligand on its surface. In both cases, the ligand binds to a cell surface receptor that is highly upregulated by the target cells, while not expressed, or expressed at low levels on normal cells. In this review, we summarize the most recent RNAi delivery strategies, including extracellular vesicles, that use a ligand-mediated approach for targeting various oncological diseases.

Decitabine Sensitizes the Radioresistant Lung Adenocarcinoma to Pemetrexed Through Upregulation of Folate Receptor Alpha

Chemotherapy is the backbone of subsequent treatment for patients with lung adenocarcinoma (LUAD) exhibiting radiation resistance, and pemetrexed plays a critical role in this chemotherapy. However, few studies have assessed changes in the sensitivity of LUAD cells to pemetrexed under radioresistant circumstances. Therefore, the objectives of this study were to delineate changes in the sensitivity of radioresistant LUAD cells to pemetrexed and to elucidate the related mechanisms and then develop an optimal strategy to improve the cytotoxicity of pemetrexed in radioresistant LUAD cells. Our study showed a much lower efficacy of pemetrexed in radioresistant cells than in parental cells, and the mechanism of action was the significant downregulation of folate receptor alpha (FRα) by long-term fractionated radiotherapy, which resulted in less cellular pemetrexed accumulation. Interestingly, decitabine effectively reversed the decrease in FRα expression in radioresistant cells through an indirect regulatory approach. Thereafter, we designed a combination therapy of pemetrexed and decitabine and showed that the activation of FRα by decitabine sensitizes radioresistant LUAD cells to pemetrexed both in vitro and in xenografts. Our findings raised a question regarding the administration of pemetrexed to patients with LUAD exhibiting acquired radioresistance and accordingly suggested that a combination of pemetrexed and decitabine would be a promising treatment strategy.

Phenol-Boronic surface functionalization of gold nanoparticles; to induce ROS damage while inhibiting the survival mechanisms of cancer cells

The natural phenolic molecule caffeic acid, show promising effects on biological systems as an anti/pro-oxidant, anti-cancer, and anti-inflammatory agent. In nanoparticle functionalization designs, most organic nanoparticle coatings are utilized only for their ability to carry chemotherapeutics and targeting ligand. In this study, UV-light and auto-oxidation polymerization of caffeic acid on top of as-prepared gold nanoparticles was utilized to bring about a 5 nm multifunctional coating. The resulting polycaffeic acid (PCA) coating was used to conjugate both boronic acid containing compounds, chemotherapeutic bortezomib (BTZ) and cancer targeting ligand folate, while inducing mitochondrial reactive oxygen species that can damage intracellular proteins and DNA. This complements the drug payload, bortezomib's cell survival inhibition properties. The drug, targeting ligand, and coating complexation are all pH cleavable under acidic pH condition (<5.0) which can be found in a tumor and endosomal microenvironment. The in vitro and in vivo experiments demonstrated cancer cytotoxicity and tumor inhibiting properties of the developed nanomedicine.

MicroRNAs (miRNAs) and Long Non-Coding RNAs (lncRNAs) as New Tools for Cancer Therapy: First Steps from Bench to Bedside

Non-coding RNAs represent a significant proportion of the human genome. After having been considered as 'junk' for a long time, non-coding RNAs are now well established as playing important roles in maintaining cellular homeostasis and functions. Some non-coding RNAs show cell- and tissue-specific expression patterns and are specifically deregulated under pathological conditions (e.g. cancer). Therefore, non-coding RNAs have been extensively studied as potential biomarkers in the context of different diseases with a focus on microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) for several years. Since their discovery, miRNAs have attracted more attention than lncRNAs in research studies; however, both families of non-coding RNAs have been established to play an important role in gene expression control, either as transcriptional or post-transcriptional regulators. Both miRNAs and lncRNAs can regulate key genes involved in the development of cancer, thus influencing tumour growth, invasion, and metastasis by increasing the activation of oncogenic pathways and limiting the expression of tumour suppressors. Furthermore, miRNAs and lncRNAs are also emerging as important mediators in drug-sensitivity and drug-resistance mechanisms. In the light of these premises, a number of pre-clinical and early clinical studies are exploring the potential of non-coding RNAs as new therapeutics. The aim of this review is to summarise the latest knowledge of the use of miRNAs and lncRNAs as therapeutic tools for cancer treatment.

Is carrot consumption associated with a decreased risk of lung cancer? A meta-analysis of observational studies

Findings of epidemiological studies regarding the association between carrot consumption and lung cancer risk remain inconsistent. The present study aimed to summarise the current epidemiological evidence concerning carrot intake and lung cancer risk with a meta-analysis. We conducted a meta-analysis of case-control and prospective cohort studies, and searched PubMed and Embase databases from their inception to April 2018 without restriction by language. We also reviewed reference lists from included articles. Prospective cohort or case-control studies reporting OR or relative risk with the corresponding 95 % CI of the risk lung cancer for the highest compared with the lowest category of carrot intake. A total of eighteen eligible studies (seventeen case-control studies and one prospective cohort study) were included, involving 202 969 individuals and 5517 patients with lung cancer. The pooled OR of eighteen studies for lung cancer was 0·58 (95 % CI 0·45, 0·74) by comparing the highest category with the lowest category of carrot consumption. Based on subgroup analyses for the types of lung cancer, we pooled that squamous cell carcinoma (OR 0·52, 95 % CI 0·19, 1·45), small-cell carcinoma (OR 0·43, 95 % CI 0·12, 1·59), adenocarcinoma (OR 0·34, 95 % CI 0·15, 0·79), large-cell carcinoma (OR 0·40, 95 % CI 0·10, 1·57), squamous and small-cell carcinoma (OR 0·85, 95 % CI 0·45, 1·62), adenocarcinoma and large-cell carcinoma (OR 0·20, 95 % CI 0·02, 1·70) and mixed types (OR 0·61, 95 % CI 0·46, 0·81). Exclusion of any single study did not materially alter the pooled OR. Integrated epidemiological evidence from observational studies supported the hypothesis that carrot consumption may decrease the risk of lung cancer, especially for adenocarcinoma.

Quantifying Carcinoembryonic Antigen-like Cell Adhesion Molecule-Targeted Liposome Delivery Using Imaging Flow Cytometry

Carcinoembryonic antigen-like cell adhesion molecules (CEACAMs) are human cell-surface proteins that can exhibit increased expression on tumor cells and are thus a potential target for novel tumor-seeking therapeutic delivery methods. We hypothesize that engineered nanoparticles containing a known interaction partner of CEACAM, Neisseria gonorrhoeae outer membrane protein Opa, can be used to deliver cargo to specific cellular targets. In this study, the cell association and uptake of protein-free liposomes and Opa proteoliposomes into CEACAM-expressing cells were measured using imaging flow cytometry. A size-dependent internalization of liposomes into HeLa cells was observed through endocytic pathways. Opa-dependent, CEACAM1-mediated uptake of liposomes into HeLa cells was observed, with limited colocalization with endosomal and lysosomal trafficking compartments. Given the overexpression of CEACAM1 on several distinct cancers and interest in using CEACAM1 as a component in treatment strategies, these results support further pursuit of investigating Opa-dependent specificity and the internalization mechanism for therapeutic delivery.

Rapid, label-free genetic detection of enteropathogens in stool without genetic isolation or amplification

Current genetic detection methods require gene isolation, gene amplification and detection with a fluorescent-tagged probe. They typically require sophisticated equipment and expensive fluorescent probes, rendering them not widely available for rapid acute infection diagnoses at the point of care to ensure timely treatment of the diseases. Here we report a rapid genetic detection method that can detect the bacterial gene directly from patient stools using a piezoelectric plate sensor (PEPS) in conjunction with a continuous flow system with two temperature zones. With stools spiked with sodium dodecyl sulfate (SDS) in situ bacteria lysing and DNA denaturation occurred in the high-temperature zone whereas in situ specific detection of the denatured DNA by the PEPS occurred in the lower-temperature zone. The outcome was a rapid genetic detection method that directly detected bacterial genes from stool in < 40 min without the need of gene isolation, gene amplification, or expensive fluorescent tag but with polymerase chain reaction (PCR) sensitivity. In 40 blinded patient stools, it detected the toxin B gene of Clostridium difficile with 95% sensitivity and 95% specificity. The all-electrical, label-free nature of the detection further supports its potential as a low-cost genetic test that can be used at the point of care.

Nanotechnology in the diagnosis and treatment of lung cancer

Lung cancer is an umbrella term for a subset of heterogeneous diseases that are collectively responsible for the most cancer-related deaths worldwide. Despite the tremendous progress made in understanding lung tumour biology, advances in early diagnosis, multimodal therapy and deciphering molecular mechanisms of drug resistance, overall curative outcomes remain low, especially in metastatic disease. Nanotechnology, in particular nanoparticles (NPs), continue to progressively impact the way by which tumours are diagnosed and treated. The unique physicochemical properties of materials at the nanoscale grant access to a diverse molecular toolkit that can be manipulated for use in respiratory oncology. This realisation has resulted in several clinically approved NP formulations and many more in clinical trials. However, NPs are not a panacea and have yet to be utilised to maximal effect in lung cancer, and medicine in a wider context. This review serves to: describe the complexity of lung cancer, the current diagnostic and therapeutic environment, and highlight the recent advancements of nanotechnology based approaches in diagnosis and treatment of respiratory malignancies. Finally, a brief outlook on the future directions of nanomedicine is provided; presently the full potential of the field is yet to be realised. By gleaning lessons and integrating advancements from neighbouring disciplines, nanomedicine can be elevated to a position where the current barriers that stymie full clinical impact are lifted.

Is Targeting the Folate Receptor in Ovarian Cancer Coming of Age?

Prognosis for women with epithelial ovarian cancer remains poor. One new molecular target in epithelial ovarian cancer is folate receptor alpha (FRα). This commentary discusses the characteristics that contribute to its attractiveness as a candidate for therapeutic intervention.

FolamiRs: Ligand-targeted, vehicle-free delivery of microRNAs for the treatment of cancer

MicroRNAs are small RNAs that negatively regulate gene expression posttranscriptionally. Because changes in microRNA expression can promote or maintain disease states, microRNA-based therapeutics are being evaluated extensively. Unfortunately, the therapeutic potential of microRNA replacement is limited by deficient delivery vehicles. In this work, microRNAs are delivered in the absence of a protective vehicle. The method relies on direct attachment of microRNAs to folate (FolamiR), which mediates delivery of the conjugated microRNA into cells that overexpress the folate receptor. We show that the tumor-suppressive FolamiR, FolamiR-34a, is quickly taken up both by triple-negative breast cancer cells in vitro and in vivo and by tumors in an autochthonous model of lung cancer and slows their progression. This method delivers microRNAs directly to tumors in vivo without the use of toxic vehicles, representing an advance in the development of nontoxic, cancer-targeted therapeutics.

An open label trial of folate receptor-targeted intraoperative molecular imaging to localize pulmonary squamous cell carcinomas

BACKGROUND

Clinical applicability of folate receptor-targeted intraoperative molecular imaging (FR-IMI) has been established for surgically resectable pulmonary adenocarcinoma. A role for FR-IMI in other lung cancer histologies has not been studied. In this study, we evaluate feasibility of FR-IMI in patients undergoing pulmonary resection for squamous cell carcinomas (SCCs).

METHODS

In a human clinical trial (NCT02602119), twelve subjects with pulmonary SCCs underwent FR-IMI with a near-infrared contrast agent that targets the folate receptor-α (FRα), OTL38. Near-infrared signal from tumors and benign lung was quantified to calculate tumor-to-background ratios (TBR). Folate receptor-alpha expression was characterized, and histopathologic correlative analyses were performed to evaluate patterns of OTL38 accumulation. An exploratory analysis was performed to determine patient and histopathologic variables that predict tumor fluorescence.

RESULTS

9 of 13 SCCs (in 9 of 12 of subjects) displayed intraoperative fluorescence upon NIR evaluation (median TBR, 3.9). OTL38 accumulated within SCCs in a FRα-dependent manner. FR-IMI was reliable in localizing nodules as small as 1.1 cm, and prevented conversion to thoracotomy for nodule localization in three subjects. Upon evaluation of patient and histopathologic variables, in situ fluorescence was associated with distance from the pleural surface, and was independent of alternative variables including tumor size and metabolic activity.

CONCLUSIONS

This work demonstrates that FR-IMI is potentially feasible in 70% of SCC patients, and that molecular imaging can improve localization during minimally invasive pulmonary resection. These findings complement previous data demonstrating that ∼98% of pulmonary adenocarcinomas are localized during FR-IMI and suggest broad applicability for NSCLC patients undergoing resection.

New Folate-Grafted Chitosan Derivative To Improve Delivery of Paclitaxel-Loaded Solid Lipid Nanoparticles for Lung Tumor Therapy by Inhalation

Inhaled chemotherapy for the treatment of lung tumors requires that drug delivery systems improve selectivity for cancer cells and tumor penetration and allow sufficient lung residence. To this end, we developed solid lipid nanoparticles (SLN) with modified surface properties. We successfully synthesized a new folate-grafted copolymer of polyethylene glycol (PEG) and chitosan, F-PEG-HTCC, with a PEG-graft ratio of 7% and a molecular weight range of 211-250 kDa. F-PEG-HTCC-coated, paclitaxel-loaded SLN were prepared with an encapsulation efficiency, mean diameter, and zeta potential of about 100%, 250 nm, and +32 mV, respectively. The coated SLN entered folate receptor (FR)-expressing HeLa and M109-HiFR cells in vitro and M109 tumors in vivo after pulmonary delivery. The coated SLN significantly decreased the in vitro half-maximum inhibitory concentrations of paclitaxel in M109-HiFR cells (60 vs 340 nM, respectively). We demonstrated that FR was involved in these improvements, especially in M109-HiFR cells. After pulmonary delivery in vivo, the coated SLN had a favorable pharmacokinetic profile, with pulmonary exposure to paclitaxel prolonged to up to 6 h and limited systemic distribution. Our preclinical findings therefore demonstrated the positive impact of the coated SLN on the delivery of paclitaxel by inhalation.

Targeting folate receptor alpha for cancer treatment

Promising targeted treatments and immunotherapy strategies in oncology and advancements in our understanding of molecular pathways that underpin cancer development have reignited interest in the tumor-associated antigen Folate Receptor alpha (FRα). FRα is a glycosylphosphatidylinositol (GPI)-anchored membrane protein. Its overexpression in tumors such as ovarian, breast and lung cancers, low and restricted distribution in normal tissues, alongside emerging insights into tumor-promoting functions and association of expression with patient prognosis, together render FRα an attractive therapeutic target. In this review, we summarize the role of FRα in cancer development, we consider FRα as a potential diagnostic and prognostic tool, and we discuss different targeted treatment approaches with a specific focus on monoclonal antibodies. Renewed attention to FRα may point to novel individualized treatment approaches to improve the clinical management of patient groups that do not adequately benefit from current conventional therapies.

Targeting tumor microenvironment to curb chemoresistance via novel drug delivery strategies

INTRODUCTION

Tumor is a heterogeneous mass of malignant cells co-existing with non-malignant cells. This co-existence evolves from the initial developmental stages of the tumor and is one of the hallmarks of cancer providing a protumorigenic niche known as tumor microenvironment (TME). Proliferation, invasiveness, metastatic potential and maintenance of stemness through cross-talk between tumors and its stroma forms the basis of TME.

AREAS COVERED

The article highlights the developmental phases of a tumor from dysplasia to the formation of clinically detectable tumors. The authors discuss the mechanistic stages involved in the formation of TME and its contribution in tumor outgrowth and chemoresistance. The authors have reviewed various approaches for targeting TME and its hallmarks along with their advantages and pitfalls. The authors also highlight cancer stem cells (CSCs) that are resistant to chemotherapeutics and thus a primary reason for tumor recurrence thereby, posing a challenge for the oncologists.

EXPERT OPINION

Recent understanding of the cellular and molecular mechanisms involved in acquired chemoresistance has enabled scientists to target the tumor niche and TME and modulate and/or disrupt this communication leading to the transformation from a tumor-supportive niche environment to a tumor-non-supporting environment and give synergistic results towards an effective management of cancer.

Assessment of folate receptor alpha and beta expression in selection of lung and pancreatic cancer patients for receptor targeted therapies

A number of folate receptor (FR) targeted small molecular drugs and monoclonal antibodies have been introduced into clinical trials to treat FR positive cancers. Because the therapeutic efficacy of these drugs depends prominently on the level of FR-α expression on the cancer cells, patients have been commonly selected for FR-targeted therapies based on the intensity of a folate-targeted radioimaging agent. Unfortunately, uptake of such imaging agents can be mediated by both major isoforms of the folate receptor, FR-α and FR-β. Logically, if the FR positive cell population in a tumor mass is dominated by FR-β positive macrophages, patients could be selected for therapy that have few FR-expressing cancer cells. Although several IHC studies have examined expression of either FR-α or FR-β, no study to date has investigated expression of both FR-α and FR-β in the same tumor mass. Herein, we utilize monoclonal antibodies specific for FR-α (mAb343) and FR-β (m909) to query each isoform's expression in a range of cancers. We show that lung and pancreatic adenocarcinomas express the full spectrum of FR-α and FR-β combinations with ~76% of lung adenocarcinomas expressing both FR-α and FR-β while pancreatic cancers express primarily FR-β. Thus, while folate-targeted imaging of lung cancer patients might accurately reflect the expression of FR-α on lung cancer cells, imaging of pancreatic cancer patients could mislead a physician into treating a nonresponding patient. Overall, these data suggest that an independent analysis of both FR-α and FR-β should be obtained to predict the potential efficacy of a folate-targeted drug.

Identification of a Folate Receptor-Targeted Near-Infrared Molecular Contrast Agent to Localize Pulmonary Adenocarcinomas

Non-small cell lung cancer (NSCLC) is the number one cancer killer in the United States. Despite attempted curative surgical resection, nearly 40% of patients succumb to recurrent disease. High recurrence rates may be partially explained by data suggesting that 20% of NSCLC patients harbor synchronous disease that is missed during resection. In this report, we describe the use of a novel folate receptor-targeted near-infrared contrast agent (OTL38) to improve the intraoperative localization of NSCLC during pulmonary resection. Using optical phantoms, fluorescent imaging with OTL38 was associated with less autofluorescence and greater depth of detection compared to traditional optical contrast agents. Next, in in vitro and in vivo NSCLC models, OTL38 reliably localized NSCLC models in a folate receptor-dependent manner. Before testing intraoperative molecular imaging with OTL38 in humans, folate receptor-alpha expression was confirmed to be present in 86% of pulmonary adenocarcinomas upon histopathologic review of 100 human pulmonary resection specimens. Lastly, in a human feasibility study, intraoperative molecular imaging with OTL38 accurately identified 100% of pulmonary adenocarcinomas and allowed for identification of additional subcentimeter neoplastic processes in 30% of subjects. This technology may enhance the surgeon's ability to identify NSCLC during oncologic resection and potentially improve long-term outcomes.

Heterologous expression of Homo sapiens alpha-folate receptors in E. coli by fusion with a trigger factor for enhanced solubilization

The role of Alpha folate receptors (FRα) in folate metabolism and cancer development has been extensively studied. The reason for this is not only associated to its direct relation to disease development but also to its potential use as a highly sensitive and specific biomarker for cancers therapies. Over the recent years, the crystal structures of human FRα complexed with different ligands were described relying on an expensive and time-consuming production process. Here, we constructed an efficient system for the expression and purification of a human FRα in E. coli. Unlike a conventional expression method we used a specific protein fusion expressing the target protein together with a trigger factor (TF). This factor is a chaperone from E. coli that assists the correct folding of newly synthesized polypeptide chains. The activity of rTFFRα was comparable to glycosylphosphatidylinositol (GPI) anchored proteins extracted from HeLa tumor cells. Our work demonstrates a straightforward and versatile approach for the production of active human FRα by heterologous expression; this approach further enhances the development of inhibition studies and biotechnological applications. The purified product was then conjugated to liposomes, obtaining a 35% higher signal from densitometry measurement on the immunoblotting assay in the contruct containing the Ni-NTA tag, as a mimesis of an exosome, which is of vital importance to nanotherapeutic techniques associated to treatment and diagnosis of tumors.

Pulmonary delivery of nanoparticle chemotherapy for the treatment of lung cancers: challenges and opportunities

Lung cancer is the second most prevalent and the deadliest among all cancer types. Chemotherapy is recommended for lung cancers to control tumor growth and to prolong patient survival. Systemic chemotherapy typically has very limited efficacy as well as severe systemic adverse effects, which are often attributed to the distribution of anticancer drugs to non-targeted sites. In contrast, inhalation routes permit the delivery of drugs directly to the lungs providing high local concentrations that may enhance the anti-tumor effect while alleviating systemic adverse effects. Preliminary studies in animals and humans have suggested that most inhaled chemotherapies are tolerable with manageable pulmonary adverse effects, including cough and bronchospasm. Promoting the deposition of anticancer drugs in tumorous cells and minimizing access to healthy lung cells can further augment the efficacy and reduce the risk of local toxicities caused by inhaled chemotherapy. Sustained release and tumor localization characteristics make nanoparticle formulations a promising candidate for the inhaled delivery of chemotherapeutic agents against lung cancers. However, the physiology of respiratory tracts and lung clearance mechanisms present key barriers for the effective deposition and retention of inhaled nanoparticle formulations in the lungs. Recent research has focused on the development of novel formulations to maximize lung deposition and to minimize pulmonary clearance of inhaled nanoparticles. This article systematically reviews the challenges and opportunities for the pulmonary delivery of nanoparticle formulations for the treatment of lung cancers.

Concordance of folate receptor-α expression between biopsy, primary tumor and metastasis in breast cancer and lung cancer patients

Folate receptor alpha (FRα) is known to be upregulated in a variety of cancers, including non-small cell lung cancer (NSCLC) and breast cancer. To ensure reliable implementation of diagnostic- and therapeutic agents, concordance of FRα expression between biopsy, primary tumor and metastases is important. Using immunohistochemistry (Mab 26B3.F2) these concordances were investigated in 60 NSCLC and 40 breast cancer patients. False positivity of FRα expression on breast and lung cancer biopsies was limited to less than 5%. In NSCLC, FRα expression was shown in 21/34 adenocarcinomas and 4/26 squamous cell carcinomas (SCC). Concordance of FRα expression between biopsy and primary tumor was achieved in respectively 83% and 91% of adenocarcinomas and SCCs. Approximately 80% of all local and distant metastases of NSCLC patients showed concordant FRα expression as their corresponding primary tumor. In breast cancer, FRα positivity was shown in 12/40 biopsies, 20/40 lumpectomies and 6/20 LN metastases, with concordance of 68% between biopsy and primary tumor and 60% between primary tumor and LN metastases. In conclusion, this study shows high concordance rates of FRα expression between biopsies and metastases compared to primary NSCLC and breast cancers, underscoring the applicability of FRα-targeted agents in these patients.

Facile synthesis of biocompatible MoSe2 nanoparticles for efficient targeted photothermal therapy of human lung cancer

A schematic illustration of FA–PL–MoSe₂ nanoparticles preparation and tumor targeted photothermal therapy.

Polymersome-based drug-delivery strategies for cancer therapeutics

Polymersomes are stable vesicles prepared from amphiphilic polymers and are more stable compared with liposomes. Although these nanovesicles have many attractive properties for in vitro/in vivo applications, liposome-based drug delivery systems are still prevalent in the market. In order to expedite the translational potential and to provide medically valuable formulations, the polymersomes need to be biocompatible and biodegradable. In this review, recent developments for biocompatible and biodegradable polymersomes, including the design of intelligent, targeted, and stimuli-responsive vesicles are summarized.

Development and evaluation of well-tolerated and tumor-penetrating polymeric micelle-based dry powders for inhaled anti-cancer chemotherapy

Despite the direct access to the lung offered by the inhalation route, drug penetration into lung tumors could remain an important issue. In this study, folate-polyethylene glycol-hydrophobically-modified dextran (F-PEG-HMD) micelles were developed as an effective pulmonary drug delivery system to reach and penetrate lung tumors and cancer cells. The F-PEG-HMD micelles were able to enter HeLa and M109-HiFR, two folate receptor-expressing cancer cell lines, in vitro, and in vivo after administration by inhalation to orthotopic M109-HiFR lung tumor grafted mice. Paclitaxel-loaded F-PEG-HMD micelles characterized in PBS by a Z-average diameter of ∼50 nm and a zeta potential of ∼-4 mV were prepared with an encapsulation efficiency of ∼100%. The loaded micelles reduced HeLa and M109-HiFR cell growth, with half maximal inhibitory concentrations of 37 and 150 nM, respectively. Dry powders embedding the paclitaxel-loaded F-PEG-HMD micelles were developed by spray-drying. In vitro, good deposition profiles were obtained, with a fine particle fraction of up to 50% and good ability to re-disperse the micelles in physiological buffer. A polymeric micelle-based dry powder without paclitaxel was well-tolerated in vivo, as assessed in healthy mice by determination of total protein content, cell count, and cytokine IL-1β, IL-6, and TNF-α concentrations in bronchoalveolar lavage fluids.

Folate Receptor α Expression Level Correlates With Histologic Grade in Lung Adenocarcinoma

CONTEXT

-Folate receptor α (FRA) is a glycosylphosphatidylinositol-anchored high-affinity folate receptor that localizes to the apical surface of epithelia when it is expressed in normal tissue. Unlike normal tissues, FRA may localize to the basolateral side in tumors. These features make FRA an attractive drug target, and several FRA-targeted drugs have been developed and are in phases of clinical testing. Folate receptor α protein expression shows intertumoral variability that may correlate with response to therapy and to clinicopathologic parameters. Using immunohistochemistry, a recent study of breast carcinomas found FRA protein expression was associated with triple-negative status and high histologic grade in breast cancer. Although a prior study of lung adenocarcinomas found the expression level of the gene encoding FRA, FOLR1, was significantly increased in low-histologic-grade tumors compared to high-histologic-grade tumors, the relationship between FRA protein expression and histologic grade has not been reported for lung adenocarcinomas.

OBJECTIVE

-To investigate the relationship between FRA protein expression level and clinicopathologic parameters in lung adenocarcinomas, including histologic grade, by performing immunohistochemistry for FRA on a cohort of non-small cell lung carcinomas.

DESIGN

-High-density tissue microarrays constructed from 188 non-small cell lung carcinomas and used in prior studies were immunostained with FRA-specific antibody clone 26B3. Folate receptor α membranous staining intensity was given a semiquantitative score from 0 to 3+ for triplicate cores of tumor and averaged for each tumor. An average semiquantitative score from 0 to 1.4 was considered low expression, and an average semiquantitative score greater than 1.4 was considered high expression.

RESULTS

-The majority (60 of 78; 77%) of lung adenocarcinomas and a minority (4 of 41; 10%) of lung squamous cell carcinomas were positive for FRA. Folate receptor α expression in lung adenocarcinomas compared with squamous cell carcinomas was statistically different (P < .001, χ(2) test). In lung adenocarcinomas, FRA expression level correlated with histologic grade (P = .005, χ(2) test for trend), but no other clinicopathologic parameter. The majority (23 of 27; 85%) of grade 1 adenocarcinomas had high FRA protein expression, whereas approximately half of grade 2 (10 of 19; 53%) and grade 3 (12 of 25; 48%) adenocarcinomas had high FRA protein expression. Out of adenocarcinomas with lepidic growth pattern, 16 of 20 (80%) showed high FRA protein expression. Out of adenocarcinomas with solid growth pattern, 2 of 6 (33%) showed high FRA protein expression. In lung adenocarcinomas, FRA expression level did not correlate with thyroid transcription factor 1, napsin A, or survival.

CONCLUSIONS

-Folate receptor α protein was expressed in the majority of lung adenocarcinomas and a minority of lung squamous cell carcinomas. Folate receptor α protein expression correlated with histologic grade for lung adenocarcinomas, and the greatest difference was observed between grade 1 and grade 3. Our results indicate that poorly differentiated adenocarcinomas or focuses of poor differentiation in a heterogeneous tumor may lack FRA protein expression and be more likely to be resistant to FRA-targeting drugs.

Next-Generation Sequencing of a Cohort of Pulmonary Large Cell Carcinomas Reclassified by World Health Organization 2015 Criteria

CONTEXT

The classification of pulmonary large cell carcinoma has undergone a major revision with the recent World Health Organization (WHO) 2015 Classification. Many large cell carcinomas are now reassigned to either adenocarcinoma with solid pattern or nonkeratinizing squamous cell carcinoma based on immunopositivity for adenocarcinoma markers or squamous cell carcinoma markers, respectively. Large cell carcinomas that are negative for adenocarcinoma and squamous cell carcinoma immunomarkers are now classified as large cell carcinoma with null immunohistochemical features (LCC-N). Although a few studies investigated the mutation profile of large cell carcinomas grouped by immunostain profile before the publication of the new WHO classification, investigation of tumors previously diagnosed as large cell carcinoma and reclassified according to the 2015 WHO classification has not, to our knowledge, been reported.

OBJECTIVE

To determine the mutation profiles of pulmonary large cell carcinomas reclassified by WHO 2015 criteria.

DESIGN

Archival cases of non-small cell lung carcinoma with large cell carcinoma morphology (n = 17) were reclassified according to 2015 WHO criteria. To determine mutation profile, we employed Ion Torrent (Life Technologies, Carlsbad, California)-based next-generation sequencing (50 genes; more than 2800 mutations) in addition to real-time quantitative reverse transcription polymerase chain reaction for ALK translocation detection.

RESULTS

Two of 17 cases (12%) were reclassified as LCC-N, and both had mutations-BRAF D594N in one case and KRAS G12C in the other case. Seven of 17 cases (41%) were reclassified in the adenocarcinoma with solid pattern group, which showed one KRAS G12C and one EGFR E709K + G719C double mutation in addition to mutations in TP53. Eight of 17 cases (47%) were reclassified in the nonkeratinizing squamous cell carcinoma group, which showed mutations in PIK3CA, CDKN2A, and TP53. No ALK translocations or amplifications were detected.

CONCLUSIONS

The adenocarcinoma with solid pattern group showed mutations typical of adenocarcinoma, whereas the nonkeratinizing squamous cell carcinoma group showed mutations typical of squamous cell carcinoma. Both LCC-N cases had mutations associated with adenocarcinoma, supporting the hypothesis that LCC-N is related to adenocarcinoma.

A current review of folate receptor alpha as a potential tumor target in non-small-cell lung cancer

Lung cancer remains the leading common cause of cancer-related death, with non-small-cell lung cancer (NSCLC) accounting for 80% of all cases. To date, platinum-based doublet chemotherapy is the cornerstone of first-line therapy. However, these agents have limited use in patients who have relapsed and have metastatic disease. Therefore, novel strategies are required to improve the clinical outcome. Folate receptor alpha (FRA) is overexpressed in the majority of NSCLC, particularly in lung adenocarcinomas. FRA is largely absent from normal tissue, making it an attractive therapeutic target. In this review, we discuss FRA expression in NSCLC, conjugated FRA agents, monoclonal antibody, and FRA-specific T-cell-based therapeutic strategies aiming to improve the cure rate of FRA-expressing NSCLC.

Nanotechnology approaches for inhalation treatment of lung diseases

Local administration of therapeutics by inhalation for treatment of lung diseases has the ability to deliver drugs, nucleic acids and peptides specifically to the site of their action and therefore enhance the efficacy of the treatment, limit the penetration of nebulized therapeutic agent(s) into the bloodstream and consequently decrease adverse systemic side effects of the treatment. Nanotechnology allows for a further enhancement of the treatment efficiency. The present review analyzes modern therapeutic approaches of inhaled nanoscale-based pharmaceutics for the detection and treatment of various lung diseases.

New dry powders for inhalation containing temozolomide-based nanomicelles for improved lung cancer therapy

Besides the numerous advantages of a chemotherapy administered by the inhalation route for lung cancer therapy, dry powder for inhalation (DPI) offers many advantages compared to other techniques and seems to be a technique that is well-adapted to an anticancer treatment. DPI formulations were developed using the cytotoxic drug temozolomide and a new folate-grafted self-assembling copolymer, a conjugate of three components, folate-polyethylene glycol-hydrophobically-modified dextran (F-PEG-HMD). F-PEG-HMD was synthesized using carbodiimide-mediated coupling chemistry in three main steps. F-PEG-HMD was characterized by 1H-NMR, mass spectrometry and thermal analysis. F-PEG-HMD presented a critical micellar concentration in water of 4x10-7 M. F-PEG-HMD nanomicelles were characterized by a trimodal particle size distribution with Z-average diameter of 83±1 nm in water. Temozolomide-loaded nanomicelles were prepared by solubilization of F-PEG-HMD in the presence of temozolomide. Temozolomide solubility in water was increased in the presence of F-PEG-HMD (2-fold increase in molar solubility) which could potentially lead to increased local concentrations in the tumor site. The temozolomide-loaded F-PEG-HMD nanomicelles were characterized by a Z-average diameter of ~50 to ~60 nm, depending on the F-PEG-HMD concentration used. The nanomicelles were then spray-dried to produce dry powders. Temozolomide remained stable during all the formulation steps, confirmed by similar in vitro anticancer properties for the DPI formulations and a raw temozolomide solution. Two of the developed DPI formulations were characterized by good aerodynamic properties (with a fine particle fraction of up to 50%) and were able to release the F-PEG-HMD nanomicelles quickly in aqueous media. Moreover, in vitro, the two DPI formulations showed wide pulmonary deposition in the lower respiratory tract where adenocarcinomas are more often found. The present study, therefore, shows that F-PEG-HMD-based dry powders for inhalation could constitute an interesting drug delivery system able to release nanomicelles that are useful in adenocarcinomas that overexpress folate receptors.

Targeting the de novo biosynthesis of thymidylate for the development of a PET probe for pancreatic cancer imaging

The development of cancer-specific probes for imaging by positron emission tomography (PET) is gaining impetus in cancer research and clinical oncology. One of the hallmarks of most cancer cells is incessant DNA replication, which requires the continuous synthesis of nucleotides. Thymidylate synthase (TSase) is unique in this context because it is the only enzyme in humans that is responsible for the de novo biosynthesis of the DNA building block 2'-deoxy-thymidylate (dTMP). TSase catalyzes the reductive methylation of 2'-deoxy-uridylate (dUMP) to dTMP using (R)-N(5),N(10)-methylene-5,6,7,8-tetrahydrofolate (MTHF) as a cofactor. Not surprisingly, several human cancers overexpress TSase, which makes it a common target for chemotherapy (e.g., 5-fluorouracil). We envisioned that [(11)C]-MTHF might be a PET probe that could specifically label cancerous cells. Using stable radiotracer [(14)C]-MTHF, we had initially found increased uptake by breast and colon cancer cell lines. In the current study, we examined the uptake of this radiotracer in human pancreatic cancer cell lines MIAPaCa-2 and PANC-1 and found predominant radiolabeling of cancerous versus normal pancreatic cells. Furthermore, uptake of the radiotracer is dependent on the intracellular level of the folate pool, cell cycle phase, expression of folate receptors on the cell membrane, and cotreatment with the common chemotherapeutic drug methotrexate (MTX, which blocks the biosynthesis of endogenous MTHF). These results point toward [(11)C]-MTHF being used as PET probe with broad specificity and being able to control its signal through MTX co-administration.

Gefitinib loaded folate decorated bovine serum albumin conjugated carboxymethyl-beta-cyclodextrin nanoparticles enhance drug delivery and attenuate autophagy in folate receptor-positive cancer cells

BACKGROUND

Active targeting endocytosis mediated by the specific interaction between folic acid and its receptor has been a hotspot in biological therapy of many human cancers. Various studies have demonstrated that folate and its conjugates could facilitate the chemotherapeutic drug delivery into folate receptor (FR)-positive tumor cells in vitro and in vivo. In order to utilize FA-FR binding specificity to achieve targeted delivery of drugs into tumor cells, we prepared Gefitinib loaded folate decorated bovine serum albumin conjugated carboxymethyl-β-cyclodextrin nanoparticles for enhancing drug delivery in cancer cells. On this context, the aim of our study was to develop a novel nano-delivery system for promoting tumor-targeting drug delivery in folate receptor-positive Hela cells.

RESULTS

We prepared folic acid (FA)-decorated bovine serum albumin (BSA) conjugated carboxymethyl-β-cyclodextrin (CM-β-CD) nanoparticles (FA-BSA-CM-β-CD NPs) capable of entrapping a hydrophobic Gefitinib. It was observed that nanoparticles are monodisperse and spherical nanospheres with an average diameter of 90.2 nm and negative surface charge of -18.6 mV. FA-BSA-CM-β-CD NPs could greatly facilitate Gefitinib uptake and enhance the toxicity to folate receptor-positive Hela cells. Under the reaction between FA and FR, Gefitinib loaded FA-BSA-CM-β-CD NPs induced apoptosis of Hela cells through elevating the expression of caspase-3 and inhibited autophagy through decreasing the expressing of LC3. It also confirmed that clathrin-mediated endocytosis and macropinocytosis exerted great influence on the internalization of both NPs.

CONCLUSIONS

These results demonstrated that FA may be an effective targeting molecule and FA-BSA-CM-β-CD NPs provided a new strategy for the treatment of human cancer cells which over-expressed folate receptors.

Beyond chemotherapy and targeted therapy: adoptive cellular therapy in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is an intractable disease for which effective treatment approaches are urgently needed. The ability to induce antigen-specific immune responses in patients with lung cancer has led to the development of immunotherapy as a novel concept for the treatment of NSCLC. Adoptive cellular therapy (ACT) represents an important advancement in cancer immunotherapy with the utilization of tumor infiltrating lymphocytes, cytokine-induced killer cells, natural killer cells and γδ T cells. In this study, we review recent advances in ACT for NSCLC in clinical trials and provide a perspective on the improvement in ACT and potential therapeutic approaches using engineered T cell therapy for NSCLC.

In vivo optical imaging of folate receptor-β in head and neck squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

Folate receptor (FR) expression, although known to be elevated in many types of cancer and inflammatory cells, has not been well characterized in head and neck squamous cell carcinoma (HNSCC). We hypothesized that tumor infiltrating inflammatory cells expressing FR-β could allow fluorescent visualization of HNSCC tumors using folate conjugated dyes even when FR expression in cancer cells is low.

STUDY DESIGN

Retrospective review of clinical pathologic specimens and in vivo animal study.

METHODS

A tissue microarray with tumor and tumor-free tissue from 22 patients with HNSCC was stained with antibodies to FR-α and FR-β. We characterized FR-β(+) cells by examining CD45, CD68, CD206, and transforming growth factor (TGF)-β expression. To investigate fluorescent imaging, mice with orthotopic tumor xenografts were imaged in vivo after intravenous injections of folate conjugated fluorescein isothiocyanate (folate-FITC) and were histologically evaluated ex vivo.

RESULTS

All tumor samples demonstrated significant FR-β staining and negligible FR-α staining. FR-β(+) cells found in tumors coexpressed CD68 and had increased expression of CD206 and TGF-β characteristic of tumor-associated macrophages. In the xenograft models, tumors showed strong in vivo fluorescence after folate-FITC injection in contrast to surrounding normal tissues. Histologic examination of the xenograft tissue similarly showed folate-FITC uptake in areas of inflammatory cellular infiltrate.

CONCLUSIONS

Although HNSCC tumor cells do not express FR, HNSCC tumors contain a significant population of FR-β-expressing macrophages. Folate conjugated fluorescent dye is able to specifically target and label tumor xenografts to permit macroscopic fluorescence imaging due to FR-β expression on the infiltrating inflammatory cells.