ZD1839, a selective epidermal growth factor receptor tyrosine kinase inhibitor, alone and in combination with radiation and chemotherapy as a new therapeutic strategy in non-small cell lung cancer

X-ray-controllable release of carbon monoxide potentiates radiotherapy by ultrastable hybrid nanoreservoirs

Carbon monoxide (CO) exhibits unique abilities in sensitizing cancer radiotherapy (RT). However, the development of a highly stable CO-delivery nanosystem with sustained CO release in tumor tissues and the prevention of CO leakage into normal tissues remains a challenge. Herein, an organic-inorganic hybrid strategy is proposed to create ultrastable CO nanoreservoirs by locking an unstable iron carbonyl (FeCO) prodrug in a stable mesoporous silica matrix. Different from traditional FeCO-loading nanoplatforms, FeCO-bridged nanoreservoirs not only tethered labile FeCO in the framework to prevent unwanted FeCO leakage, but also achieved sustained CO release in response to X-ray and endogenous H2O2. Importantly, FeCO-bridged nanoreservoirs exhibited the sequential release of CO and Fe2+, thereby performing highly efficient chemodynamic therapy. Such a powerful combination of RT, gas therapy, and chemodynamic therapy boosts robust immunogenic cell death, thus enabling the elimination of deeply metastatic colon tumors with minimal side effects. The proposed organic-inorganic hybrid strategy opens a new window for the development of stable nanoreservoirs for the on-demand delivery of unstable gases and provides a feasible approach for the sequential release of CO and metal ions from metal carbonyl complexes.

The treatment in patients with unresectable locally advanced non-small cell lung cancer: Explorations on hot issues

The treatment efficacy for patients with unresectable, locally advanced non-small-cell lung cancer (LA-NSCLC) stagnated for a long time until the advent of immunotherapy. Immune checkpoint inhibitors, particularly programmed cell death protein 1/programmed death-ligand 1 inhibitors, have thrived, reshaping the treatment landscape for patients with lung cancer. Based on the results of the PACIFIC trial, concurrent chemoradiotherapy followed by durvalumab has become the standard of care for patients with unresectable LA-NSCLC; however, numerous issues are yet to be resolved. Currently, several clinical trials are exploring an optimal treatment paradigm, and we have summarized them for comparison to eliminate barriers. In addition, we discuss better predictive biomarkers, therapeutic options for specific populations, and other challenges to identify directions for future research design.

Symptomatic Radiation Pneumonitis in NSCLC Patients Receiving EGFR-TKIs and Concurrent Once-daily Thoracic Radiotherapy: Predicting the Value of Clinical and Dose-volume Histogram Parameters

BACKGROUND

The incidence of symptomatic radiation pneumonitis (RP) and its relationship with dose-volume histogram (DVH) parameters in non-small cell lung cancer (NSCLC) patients receiving epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and concurrent once-daily thoracic radiotherapy (TRT) remain unclear. We aim to analyze the values of clinical factors and dose-volume histogram (DVH) parameters to predict the risk for symptomatic RP in these patients.

METHODS

Between 2011 and 2019, we retrospectively analyzed and identified 85 patients who had received EGFR-TKIs and once-daily TRT simultaneously (EGFR-TKIs group) and 129 patients who had received concurrent chemoradiotherapy (CCRT group). The symptomatic RP was recorded according to the Common Terminology Criteria for Adverse Event (CTCAE) criteria (grade 2 or above). Statistical analyses were performed using SPSS 26.0.

RESULTS

In total, the incidences of symptomatic (grade≥2) and severe RP (grade≥3) were 43.5% (37/85) and 16.5% (14/85) in EGFR-TKIs group vs 27.1% (35/129) and 10.1% (13/129) in CCRT group respectively. After 1:1 ratio between EGFR-TKIs group and CCRT group was matched by propensity score matching, chi-square test suggested that the incidence of symptomatic RP in the MATCHED EGFR-TKIs group was higher than that in the matched CCRT group (χ2=4.469, P=0.035). In EGFR-TKIs group, univariate and multivariate analyses indicated that the percentage of ipsilateral lung volume receiving ≥30 Gy (ilV30) [odds ratio (OR): 1.163, 95%CI: 1.036-1.306, P=0.011] and the percentage of total lung volume receiving ≥20 Gy (tlV20) (OR: 1.171, 95%CI: 1.031-1.330, P=0.015), with chronic obstructive pulmonary disease (COPD) or not (OR: 0.158, 95%CI: 0.041-0.600, P=0.007), were independent predictors of symptomatic RP. Compared to patients with lower ilV30/tlV20 values (ilV30 and tlV20<cut-off point values) and without COPD, patients with higher ilV30/tlV20 values (ilV30 and tlV20>cut-off point values) and COPD had a significantly higher risk for developing symptomatic RP, with a hazard ratio (HR) of 1.350 (95%CI: 1.190-1.531, P<0.001).

CONCLUSIONS

Patients receiving both EGFR-TKIs and once-daily TRT were more likely to develop symptomatic RP than patients receiving concurrent chemoradiotherapy. The ilV30, tlV20, and comorbidity of COPD may predict the risk of symptomatic RP among NSCLC patients receiving EGFR-TKIs and conventionally fractionated TRT concurrently.

Targeted Sequencing of Circulating Cell Free DNA Can Be Used to Monitor Therapeutic Efficacy of Tyrosine Kinase Inhibitors in Non-small Cell Lung Cancer Patients

BACKGROUND/AIM

Circulating tumor DNA (ctDNA) bears specific mutations derived from tumor cells. The amount of mutant ctDNA may reflect tumor burden. In this study, we detected epidermal growth factor receptor (EGFR) mutations in ctDNA as a monitoring marker for the response of non-small cell lung cancer (NSCLC) patients to tyrosine kinase inhibitors (TKIs).

PATIENTS AND METHODS

Serial plasma samples from eight NSCLC patients during TKI treatment were collected. Libraries with barcoded adapters were constructed from ctDNA of these plasma samples using a PCR-based targeted DNA panel. The libraries were then sequenced for measuring EGFR mutations. In addition, carcinoembryonic antigen (CEA) was also measured in these patients.

RESULTS

In six patients who suffered disease progression (PD), five had elevated EGFR mutation reads before PD. In the two patients who did not develop PD, EGFR mutations remained undetectable in their plasma. The CEA levels were higher than the cutoff value in most samples and had a poor correlation with disease status.

CONCLUSION

The mutation count of tumor-specific mutations can be a monitoring marker of TKI treatment in NSCLC patients.

Effect of 4,5-diazafluorene derivative on γδ T cell-mediated cytotoxicity against renal cell carcinoma

AIMS

This study aimed to investigate the effect of previously synthesized 4,5-diazafluorene derivative (14c) on γδ T cell-mediated cytotoxicity against renal cell carcinoma (RCC).

MATERIALS AND METHODS

A real-time cell analyzer monitored cell proliferation, and Cell Counting Kit-8 determined cell viability. A reverse transcription-polymerase chain reaction analyzed gene expression, and protein expression was determined by cellular immunofluorescence analysis and Western blot.

KEY FINDINGS

The compound 14c induced the expression of immunomodulatory molecules, such as natural killer group 2, member D ligands (NKG2DLs), fibroblast-associated (Fas) death receptor, and tumor necrosis factor-related apoptosis-inducing ligand receptors (TRAILRs) in RCC. In addition, 14c induced DNA damage responses in RCC. Blocking DNA damage by KU-55933 reduced the effect of γδ T cells on 14c-treated RCC, suggesting that DNA damage responses were involved in the augmentation of γδ T cell-mediated cytotoxicity. Treating 786-O cells with a nitrogen-containing bisphosphonate prodrug further enhanced the anti-tumor effect of γδ T cell plus 14c combination treatment.

SIGNIFICANCE

The present evidence indicates that 14c induced DNA damage responses in RCC and augmented γδ T cell-mediated cytotoxicity primarily through NKG2D/NKG2DLs pathways, suggesting potential cancer immunotherapy for harnessing γδ T cells and small compounds that induce DNA damage responses.

EGFR tyrosine kinase inhibitors in non-small cell lung cancer: treatment paradigm, current evidence, and challenges

Therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) for patients with EGFR-mutated non-small cell lung cancer (NSCLC) has been shown to have superior outcomes when compared to chemotherapy. First-generation EGFR TKI, including gefitinib and erlotinib, and second-generation EGFR TKI, including afatinib and dacomitinib, proved to be effective in patients with NSCLC harboring EGFR-sensitizing mutation. Later, resistance mutations were identified. Consequently, osimertinib, a third-generation EGFR TKI, was studied and demonstrated activity against EGFR-sensitizing and resistant mutations. Osimertinib moved recently to the first-line setting with the positive results of the FLAURA (AZD9291 Versus Gefitinib or Erlotinib in Patients With Locally Advanced or Metastatic Non-small Cell Lung Cancer) trial. The use of these drugs is limited by their cost and availability mainly in middle- to low-income countries.

Targeting Molecular Mechanisms Underlying Treatment Efficacy and Resistance in Osteosarcoma: A Review of Current and Future Strategies

Osteosarcoma is the most common primary malignant bone tumour in children and adolescents. Due to micrometastatic spread, radical surgery alone rarely results in cure. Introduction of combination chemotherapy in the 1970s, however, dramatically increased overall survival rates from 20% to approximately 70%. Unfortunately, large clinical trials aiming to intensify treatment in the past decades have failed to achieve higher cure rates. In this review, we revisit how the heterogenous nature of osteosarcoma as well as acquired and intrinsic resistance to chemotherapy can account for stagnation in therapy improvement. We summarise current osteosarcoma treatment strategies focusing on molecular determinants of treatment susceptibility and resistance. Understanding therapy susceptibility and resistance provides a basis for rational therapy betterment for both identifying patients that might be cured with less toxic interventions and targeting resistance mechanisms to sensitise resistant osteosarcoma to conventional therapies.

PNA Clamping in Nucleic Acid Amplification Protocols to Detect Single Nucleotide Mutations Related to Cancer

This review describes the application of peptide nucleic acids (PNAs) as clamps that prevent nucleic acid amplification of wild-type DNA so that DNA with mutations may be observed. These methods are useful to detect single-nucleotide polymorphisms (SNPs) in cases where there is a small amount of mutated DNA relative to the amount of normal (unmutated/wild-type) DNA. Detecting SNPs arising from mutated DNA can be useful to diagnose various genetic diseases, and is especially important in cancer diagnostics for early detection, proper diagnosis, and monitoring of disease progression. Most examples use PNA clamps to inhibit PCR amplification of wild-type DNA to identify the presence of mutated DNA associated with various types of cancer.

Polyphyllin VI Induces Caspase-1-Mediated Pyroptosis via the Induction of ROS/NF-κB/NLRP3/GSDMD Signal Axis in Non-Small Cell Lung Cancer

Trillium tschonoskii Maxim (TTM), a traditional Chinese medicine, has been demonstrated to have a potent anti-tumor effect. Recently, polyphyllin VI (PPVI), a main saponin isolated from TTM, was reported by us to significantly suppress the proliferation of non-small cell lung cancer (NSCLC) via the induction of apoptosis and autophagy in vitro and in vivo. In this study, we further found that the NLRP3 inflammasome was activated in PPVI administrated A549-bearing athymic nude mice. As is known to us, pyroptosis is an inflammatory form of caspase-1-dependent programmed cell death that plays an important role in cancer. By using A549 and H1299 cells, the in vitro effect and action mechanism by which PPVI induces activation of the NLRP3 inflammasome in NSCLC were investigated. The anti-proliferative effect of PPVI in A549 and H1299 cells was firstly measured and validated by MTT assay. The activation of the NLRP3 inflammasome was detected by using Hoechst33324/PI staining, flow cytometry analysis and real-time live cell imaging methods. We found that PPVI significantly increased the percentage of cells with PI signal in A549 and H1299, and the dynamic change in cell morphology and the process of cell death of A549 cells indicated that PPVI induced an apoptosis-to-pyroptosis switch, and, ultimately, lytic cell death. In addition, belnacasan (VX-765), an inhibitor of caspase-1, could remarkably decrease the pyroptotic cell death of PPVI-treated A549 and H1299 cells. Moreover, by detecting the expression of NLRP3, ASC, caspase-1, IL-1β, IL-18 and GSDMD in A549 and h1299 cells using Western blotting, immunofluorescence imaging and flow cytometric analysis, measuring the caspase-1 activity using colorimetric assay, and quantifying the cytokines level of IL-1β and IL-18 using ELISA, the NLRP3 inflammasome was found to be activated in a dose manner, while VX-765 and necrosulfonamide (NSA), an inhibitor of GSDMD, could inhibit PPVI-induced activation of the NLRP3 inflammasome. Furthermore, the mechanism study found that PPVI could activate the NF-κB signaling pathway via increasing reactive oxygen species (ROS) levels in A549 and H1299 cells, and N-acetyl-L-cysteine (NAC), a scavenger of ROS, remarkably inhibited the cell death, and the activation of NF-κB and the NLRP3 inflammasome in PPVI-treated A549 and H1299 cells. Taken together, these data suggested that PPVI-induced, caspase-1-mediated pyroptosis via the induction of the ROS/NF-κB/NLRP3/GSDMD signal axis in NSCLC, which further clarified the mechanism of PPVI in the inhibition of NSCLC, and thereby provided a possibility for PPVI to serve as a novel therapeutic agent for NSCLC in the future.

RLIP controls receptor-ligand signaling by regulating clathrin-dependent endocytosis

RLIP (Ral-interacting protein) is a multifunctional protein that couples ATP hydrolysis with the movement of substances. Its primary function appears to be in the plasma membrane, where it catalyzes the ATP-dependent efflux of glutathione-conjugates (GS-Es), as well as un-metabolized drugs and toxins. In the plasma membrane, its interaction with the clathrin adaptor protein AP2 localizes it to endocytic vesicle, where its GS-E-stimulated ATPase and transport activity are required for clathrin-dependent endocytosis (CDE). CDE is an essential mechanism for internalizing ligand-receptor complexes that signal proliferation (EGF, insulin, IGF1), apoptosis (TNFα, TRAIL, Fas-L), and differentiation and morphogenesis (TGFβ, WNT, Notch, SHH). Aberrant functioning of these pathways appears crucial for most cancer cells to evade apoptosis, invade surrounding tissues, and metastasize. Internalization of receptor-ligand complexes by CDE begins a sequence of events that can terminate, initiate, or modulate downstream signaling; the consequences of signaling through these downstream pathways may be inherently different in cancer and normal cells, a view supported by numerous basic and clinical observations. In this review, we will discuss the GS-E transport activity of RLIP, which determines the rate of ligand endocytosis, and how the inhibition and/or depletion of RLIP globally disrupts in ligand-receptor signaling.

The impact of systemic precision medicine and immunotherapy treatments on brain metastases

Metastases from melanoma, lung and breast cancer are among the most common causes of intracranial malignancy. Standard of care for brain metastases include a combination of surgical resection, stereotactic radiosurgery, and whole-brain radiation. However, evidence continues to accumulate regarding the efficacy of molecularly-targeted systemic treatments and immunotherapy. For non-small cell lung cancer (NSCLC), numerous clinical trials have demonstrated intracranial activity for inhibitors of EGFR and ALK. Patients with melanoma brain metastases may benefit from systemic therapy using BRAF-inhibitors with and without trametinib. Several targeted options are available for breast cancer brain metastases that overexpress HER2, although agents with intracranial activity are still needed for other molecular subtypes. Immune checkpoint inhibitors including anti-CTLA-4 and anti-PD-1/PD-L1 antibodies are yielding impressive responses in intracranial manifestations of metastatic melanoma and NSCLC. Given the promising early results with these emerging therapies, management of eligible patients will require increased multidisciplinary discussion incorporating novel systemic treatment approaches prior or in addition to local therapy.

Point-of-Care Systems for Rapid DNA Quantification in Oncology

The development of new powerful applications and the improvement in fabrication techniques are promising an explosive growth in lab-on-chip use in the upcoming future. As the demand reaches significant levels, the semiconductor industry may enter in the field, bringing its capability to produce complex devices in large volumes, high quality and low cost. The lab-on-chip concept, when applied to medicine, leads to the point-of-care concept, where simple, compact and cheap instruments allow diagnostic assays to be performed quickly by untrained personnel directly at the patient's side. In this paper, some practical and economical considerations are made to support the advantages of point-of-care testing. A series of promising technologies developed by STMicroelectronics on lab-on-chips is also presented, mature enough to enter in the common medical practice. The possible use of these techniques for cancer research, diagnosis and treatment are illustrated together with the benefits offered by their implementation in point-of-care testing.

Targeted therapy of brain metastases: latest evidence and clinical implications

Brain metastases (BM) occur in 20-40% of patients with cancer and 60-75% of patients with BM become symptomatic. Due to an aging population and advances in the treatment of primary cancers, patients are living longer and are more likely to experience complications from BM. The diagnosis of BM drastically worsens long-term survival rates, with multiple metastases being a poor prognostic factor. Until recently, the mainstay of treatment consisted of stereotactic radiosurgery (SRS), surgical resection, whole brain radiation therapy (WBRT), or a combination of these modalities. Systemic chemotherapy has been felt largely ineffective in the treatment of BM due to the presence of the blood-brain barrier (BBB), which includes efflux pumps on brain capillaries. Over the past decade however, researchers have identified therapeutic agents that are able to cross the BBB. These findings could make a multimodality treatment approach possible, consisting of surgery, radiation, immunotherapy, and targeted therapy, which could lead to better disease control in this patient population and prolong survival. In this review, we discuss present evidence on available targeted therapies and their role in the treatment of BM from primary tumors with the highest prevalence of central nervous system (CNS) involvement, specifically non-small cell lung cancer (NSCLC), breast cancer melanoma, and renal cell carcinoma.

Gefitinib (ZD1839, Iressa®): a selective epidermal growth factor receptor-tyrosine kinase inhibitor

Objective: To provide a comprehensive review of the clinical pharmacology and toxicology of gefitinib, with particular attention to its use in early clinical trials.

Data source: A PubMed search was conducted using the terms ZD1839, gefitinib, and epidermal growth factor receptor (EGFR). All data from this search were reviewed and other relevant papers identified. The abstracts from the annual meetings of the American Society of Clinical Oncology were also reviewed.

Data extraction: The aim of the review was to be comprehensive and descriptive. The authors reviewed studies and case reports containing information deemed to be of interest.

Conclusions: EGFR is expressed, overex-pressed, or disregulated in a variety of human solid tumors, resulting in an enhancement of tumor growth. Gefitinib is a selective reversible inhibitor of EGFR that has shown activity in several tumor types. As an oral agent, it is extensively metabolized in the liver through the cytochrome P450 enzyme system, particularly the isoenzyme CYP3A4. In the phase II, IDEAL 1 and 2 trials, gefitinib has shown a response rate of 8.8% -18.4% in refractory lung cancer. Clinical trials in various other nonlung cancer patients include studies of gefitinib as a monotherapy or in combination with various chemotherapy, radiation, and/or hormone therapy regimens. Skin and gastrointestinal toxi-cities are the most frequent adverse events of gefitinib. Recently, interstitial pneumonia has emerged as one of the serious adverse effects among gefitinib patients. In summary, the role of gefitinib in combination or as a monotherapy for a variety of cancers is still evolving.

Gefitinib Therapy for Advanced Non–Small-Cell Lung Cancer

OBJECTIVE:

To review the pharmacology, pharmacokinetics, clinical efficacy, and toxicity of gefitinib in non–small-cell lung cancer (NSCLC).

DATA SOURCES:

Primary literature search through MEDLINE and CANCERLIT, and abstract presentations (1966–May 2003).

STUDY SELECTION AND DATA EXTRACTION:

All published trials and abstracts citing gefitinib were evaluated, and all information deemed relevant was included in this article.

DATA SYNTHESIS:

NSCLC is known to overexpress epidermal growth factor receptor (EGFR). Gefitinib is a selective EGFR tyrosine kinase inhibitor. Based on the Phase I/II trial results, the optimal dose is 250 mg/d orally. It is well tolerated, with minimal and reversible toxicity. Skin rash and diarrhea are the most common adverse effects. Recent trials have shown that gefitinib provided a 10% tumor response rate and improved disease-related symptoms in patients with refractory, advanced NSCLC.

CONCLUSIONS:

Gefitinib, with a unique mechanism of action and favorable toxicity profile, has demonstrated clinical activity in NSCLC patients with chemotherapy-refractory disease. It provides a valuable addition to the treatment options as monotherapy in patients with advanced NSCLC after failure of both platinum-based and docetaxel chemotherapies. Further research is required to evaluate the use of gefitinib in different clinical settings.

Recent Advances and Prospects for Multimodality Therapy in Pancreatic Cancer

The outcomes for treatment of pancreatic cancer have not improved dramatically in many decades. However, the recent promising results with combination chemotherapy regimens for metastatic disease increase optimism for future treatments. With greater control of overt or occult metastatic disease, there will likely be an expanding role for local treatment modalities, especially given that nearly a third of pancreatic cancer patients have locally destructive disease without distant metastatic disease at the time of death. Technical advances have allowed for the safe delivery of dose-escalated radiation therapy, which can then be combined with chemotherapy, targeted agents, immunotherapy, and nanoparticulate drug delivery techniques to produce novel and improved synergistic effects. Here we discuss recent advances and future directions for multimodality therapy in pancreatic cancer.

Personalized treatment of early-stage non-small-cell lung cancer: the challenging role of EGFR inhibitors

Adjuvant cisplatin-based chemotherapy significantly improves outcomes of completely resected early-stage non-small-cell lung cancer (NSCLC) patients. However, its effect on overall survival is limited and may be unsuitable for many patients due to toxicity. Targeted therapies and individualization of adjuvant treatment offer the potential to improve curability and extend survival of these patients while decreasing toxicity. Here we review Phase II and III studies examining the role of EGF receptor inhibitors, including tyrosine kinase inhibitors and the monoclonal antibody cetuximab, as adjuvant therapy in resected patients or as part of multimodality treatment for stage III NSCLC. Recent results from genotype-directed adjuvant tyrosine kinase inhibitors trials including early-stage NSCLC patients with EGFR mutations are promising, but more data are needed to support their use in this setting.

The epidermal growth factor receptor (EGRF) in lung cancer

In the last decade, important advances have been made in understanding of cancer biology, particularly non-small-cell lung cancer (NSCLC) with the discovery of oncogenic drivers of the disease. The epidermal growth factor receptor (EGFR) gene and its pathways was the first oncogenic driver discovered to be mutated and treatable in lung cancer. Treatment with EGFR tyrosine kinase inhibitors (TKIs) is the standard of care for molecularly selected EGFR-mutant patients, while its role in unselected lung cancer patients is nowadays controversial. This review will provide an overview of the EGFR pathway and options for its treatment of lung cancer.

[Clinical developments for the EGFR-TKI combined with radiotherapy in advanced non-small cell lung cancer]

肺癌是全球最常见的恶性肿瘤之一，严重威胁人类生命。近年来，以表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor tyrosine kinase inhibitors, EGFR-TKIs）为首的靶向药物在肺癌治疗中取得巨大进展。因其具有高选择性和低毒性的优势，目前已成为Ⅳ期非小细胞肺癌（non-small cell lung cancer, NSCLC）EGFR突变患者的一线治疗方案。然而随着临床的广泛应用，继发耐药成为临床亟待解决的问题。近年来，基础研究证实，EGFR-TKI具有放射增敏性，理论上二者联合不但可以解决放疗后期肿瘤的放射抵抗以及EGFR-TKI继发耐药，还可以增加对肿瘤杀伤能力，同时副反应较同步放化疗小。因此，EGFR-TKI与放疗联合成为晚期NSCLC（Ⅲb期/Ⅳ期）极具探索的治疗模式。本文就EGFR-TKI与放疗联合治疗晚期NSCLC的基础与临床研究进展进行综述。

Chemoradiation for definitive, preoperative, or postoperative therapy of locally advanced non-small cell lung cancer

Over the last few decades, the integration of chemotherapy and radiation has played a crucial role in the management of locally advanced non-small cell lung cancer (NSCLC). Locally advanced NSCLC is a very heterogeneous disease. Because of this heterogeneity, advanced NSCLC can be managed in various ways depending on the bulk of disease, the comorbidities of the patient, and the expertise and resources of the treating physicians and facilities. This review describes the evolution of current treatment strategies and predicted future changes for the management of locally advanced NSCLC.

Epidermal growth factor receptor: is it a feasible target for the treatment of osteosarcoma?

Purpose

Features of epidermal growth factor receptor (EGFR) expression in osteosarcoma and in vitro efficacies of EGFR inhibitors against osteosarcoma cells were evaluated.

Materials and Methods

Thirty biopsy samples of osteosarcoma patients were retrospectively analyzed for EGFR protein expression by immunohistochemistry. Relationships between EGFR expression and clinicopathologic characteristics and treatment outcomes were evaluated. Four osteosarcoma cell lines were analyzed for EGFR and p-EGFR expression by western blotting. Efficacies of gefitinib and BIBW2992 on osteosarcoma cells were evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Tyrosine kinase domains in exons 18 to 21 were sequenced and gene expression analyses of EGFR and PTEN were performed in four osteosarcoma cell lines.

Results

EGFR protein was expressed in 27 (90%) samples (6 low, 12 intermediate, 9 high) and in three cell lines. Intermediate or high staining for EGFR was related to a tumor volume<150 mL (p<0.001) and histologic subtype other than osteoblastic type (p=0.03). However, EGFR expression was not associated with histologic response to preoperative chemotherapy or survival. Gefitinib and BIBW 2992 did not have any significant inhibitory effect on cell viabilities. DNA sequencing analysis revealed three osteosarcoma cell lines have single base changes at codon 2361 of exon 20 (G to A), without affecting translation results. Furthermore, no mutation was found to be associated with constitutive EGFR activation.

Conclusion

In the present study, gefitinib and BIBW2992 were not effective against osteosarcoma cells. However, as osteosarcoma cells express EGFR, further studies are necessary to explore the potential of other therapeutic agents targeting EGFR.

Novel approaches of chemoradiotherapy in unresectable stage IIIA and stage IIIB non-small cell lung cancer

Approximately one third of patients with non-small cell lung cancer have unresectable stage IIIA or stage IIIB disease, and appropriate patients are candidates for chemoradiotherapy with curative intent. The optimal treatment paradigm is currently undefined. Concurrent chemoradiotherapy, compared with sequential chemotherapy and thoracic radiation therapy (TRT), results in superior overall survival outcomes as a result of better locoregional control. Recent trials have revealed efficacy for newer chemotherapy combinations similar to that of older chemotherapy combinations with concurrent TRT and a lower rate of some toxicities. Ongoing phase III trials will determine the roles of cisplatin and pemetrexed concurrent with TRT in patients with nonsquamous histology, cetuximab, and the L-BLP25 vaccine. It is unlikely that bevacizumab will have a role in stage III disease because of its toxicity. Erlotinib, gefitinib, and crizotinib have not been evaluated in stage III patients selected based on molecular characteristics. The preliminary results of a phase III trial that compared conventionally fractionated standard-dose TRT (60 Gy) with high-dose TRT (74 Gy) revealed an inferior survival outcome among patients assigned to the high-dose arm. Hyperfractionation was investigated previously with promising results, but adoption has been limited because of logistical considerations. More recent trials have investigated hypofractionated TRT in chemoradiotherapy. Advances in tumor targeting and radiation treatment planning have made this approach more feasible and reduced the risk for normal tissue toxicity. Adaptive radiotherapy uses changes in tumor volume to adjust the TRT treatment plan during therapy, and trials using this strategy are ongoing. Ongoing trials with proton therapy will provide initial efficacy and safety data.

Tailored cancer immunotherapy using combinations of chemotherapy and a mixture of antibodies against EGF-receptor ligands

Growth factors are implicated in several processes essential for cancer progression. Specifically, growth factors that bind to ErbB family receptors have been implicated in cell proliferation and in resistance of solid tumors to chemotherapy. We quantified ligand secretion by several human cancer cell lines, and generated mAbs against two ligands, namely TGF-alpha and heparin-binding EGF-like growth factor. These growth factors are frequently secreted by pancreatic tumor cell lines, including BxPC3 cells. The monoclonal antibodies were tested for their antigen specificity and ability to inhibit growth of BxPC3 cells in vitro. Combining the two antibodies resulted in enhanced inhibition of BxPC3 cell growth, both in vitro and in tumor-bearing animals. Hence, we combined the two antibodies with gemcitabine, an effective chemotherapeutic drug commonly used to treat pancreatic cancer patients. Because treatment with a combination of two monoclonal antibodies enhanced the ability of chemotherapy to inhibit BxPC3 tumors in mice, we propose a general cancer therapeutic strategy that entails profiling the repertoire of growth factors secreted by a tumor, and combining with chemotherapy several antibodies capable of blocking autocrine ligands.

Impaired SHP2-mediated extracellular signal-regulated kinase activation contributes to gefitinib sensitivity of lung cancer cells with epidermal growth factor receptor-activating mutations

Most non-small cell lung cancers (NSCLC) display elevated expression of epidermal growth factor receptor (EGFR), but response to EGFR kinase inhibitors is predominantly limited to NSCLC harboring EGFR-activating mutations. These mutations are associated with increased activity of survival pathways, including phosphatidylinositol 3-kinase/AKT and signal transducer and activator of transcription 3/5. We report that EGFR-activating mutations also surprisingly lead to decreased ability to activate extracellular signal-regulated kinase (ERK) compared with wild-type EGFR. In NSCLC cells and mouse embryonic fibroblasts expressing mutant EGFR, this effect on ERK correlates with decreased EGFR internalization and reduced phosphorylation of SHP2, a tyrosine phosphatase required for the full activation of ERK. We further show that ERK activation levels affect cellular response to gefitinib. NSCLC cells with EGFR mutation display reduced gefitinib sensitivity when ERK activation is augmented by expression of constitutively active mutants of mitogen-activated protein kinase/ERK kinase (MEK). Conversely, in a NSCLC cell line expressing wild-type EGFR, gefitinib treatment along with or following MEK inhibition increases death response compared with treatment with gefitinib alone. Our results show that EGFR-activating mutations may promote some survival pathways but simultaneously impair others. This multivariate alteration of the network governing cellular response to gefitinib, which we term "oncogene imbalance," portends a potentially broader ability to treat gefitinib-resistant NSCLC.

A phase I/II trial of gefitinib given concurrently with radiotherapy in patients with nonmetastatic prostate cancer

PURPOSE

To estimate the safety and tolerability of daily administration of 250 mg of gefitinib given concurrently with three-dimensional conformal radiotherapy for patients with nonmetastatic prostate cancer.

METHODS AND MATERIALS

A total of 42 patients with T2-T3N0M0 tumors were treated in a nonrandomized single-center study. A prostate-specific antigen (PSA) level of <20 and a good performance status (WHO, 0-1) were required. Adjuvant or neoadjuvant hormone treatments were not allowed. A daily regimen of 250 mg of gefitinib was started 1 week before radiation therapy began and lasted for the duration of radiation therapy. A dose of 50.4 Gy (1.8 Gy/day) was administered to the tumor, prostate, and seminal vesicles, followed by a 22-Gy booster (2 Gy/day) for a total dose of 72.4 Gy. Correlative studies included analysis of epidermal growth factor receptor (EGFR), EGFRvIII, and phosphorylated EGFR in tumors and tumor necrosis factor, interleukin-1alpha (IL-1alpha), and IL-6 in serum.

RESULTS

Maximum tolerated dose was not reached in phase I (12 patients), and 30 additional patients were treated in phase II. Thirty (71.4%) patients completed trial medication. Dose-limiting toxicities were recorded for 16 (38.1%) patients, the most common of which was a grade 3 to 4 increase in transaminase (6 patients). After a median follow-up of 38 months, there were no deaths due to prostate cancer. The estimated PSA relapse-free survival rate at 4 years (Kaplan-Meier) was 97%, the salvage therapy-free survival rate was 91%, and the overall survival rate was 87%. These figures compared favorably with those of matched patients treated with radiation only at higher doses.

CONCLUSIONS

The combination of gefitinib and radiation is reasonably well tolerated and has promising activity against nonmetastatic prostate cancer.

The Role of Gefitinib in Lung Cancer Treatment

Gefitinib (Iressa) is a novel targeted therapy that inhibits the tyrosine kinase activity of the epidermal growth factor receptor by competitively blocking the ATP binding site. In preclinical studies gefitinib has shown potent activity in a number of tumor models, including several lung cancer cell lines and xenografts. Two large randomized Phase II studies (IDEAL 1 and IDEAL 2) in pretreated non-small cell lung cancer reported a response rate approaching 20% in second-line patients and approximately 10% in those pretreated with two or more chemotherapy regimens. The median survival in these two studies approached 6-8 months. As a first-line therapy, gefitinib has been assessed in combination with two different chemotherapy regimens in two large randomized studies (INTACT 1 and INTACT 2). Both studies failed to show an improvement in survival on a total patient accrual of >1000 patients in each study. Other end points (e.g., time to progression and response rate) were also not improved by the addition of gefitinib. Additional studies are indicated to assess the possible role of gefitinib in the maintenance of patients who received chemotherapy or chemoradiotherapy. Studies investigating gefitinib as first-line monotherapy are also required.

ANXA8 down-regulation by EGF-FOXO4 signaling is involved in cell scattering and tumor metastasis of cholangiocarcinoma

BACKGROUND & AIMS

The sarcomatoid change in cholangiocarcinoma (CC) contributes to more aggressive intrahepatic spread and widespread metastasis. Therefore, the aim of this study was to identify the molecular mechanisms of CC metastasis during tumor progression and sarcomatoid change.

METHODS

Using the subtraction suppression hybridization (SSH) method, we identified altered expression of the candidate gene ANXA8 and epidermal growth factor receptor (EGFR) in sarcomatoid CC cells. We assessed ANXA8 expression during the progression of CC in cells and tissues and examined its functional significance by performing in vitro cell experiments and using in vivo animal models.

RESULTS

ANXA8 is highly expressed in human and hamster CCs but is down-regulated with tumor dedifferentiation. ANXA8 is transcriptionally down-regulated by epidermal growth factor (EGF), which is correlated with the morphologic changes of the epithelial-to-mesenchymal transition (EMT) in the CC cells. Furthermore, ectopic ANXA8 reverses the morphology of cells, and this is associated with focal adhesion kinase expression and altered F-actin dynamics. EGFR and its downstream targets, phosphatidylinositol-3-kinase and Akt, are linked to the phosphorylation of FOXO4, which leads to the inhibition of ANXA8 transcription. In addition, an in vitro cell invasion assay and in vivo spontaneous metastasis assay reveal that ANXA8 inhibits the cell migratory and metastatic characteristics of CC cells.

CONCLUSIONS

These findings suggest that FOXO4 and ANXA8 play key roles in growth factor-mediated tumor progression and metastasis during the EMT change in CC.

Phosphorylated epidermal growth factor receptor and cyclooxygenase-2 expression in localized non-small cell lung cancer

PURPOSE

The prognostic significance of epidermal growth factor receptor (EGFR) and cyclooxygenase-2 (COX-2) expression remains unestablished, although EGFR and COX-2 are frequently overexpressed in non-small cell lung cancer (NSCLC). Considering the importance of EGFR activation after ligand binding, however, the expression of phosphorylated EGFR (p-EGFR) may have more significance in predicting tumor aggressiveness in NSCLC than either EGFR or COX-2 expression.

PATIENTS AND METHODS

We studied the relationships between p-EGFR, EGFR, and COX-2 overexpression and examined their association with prognosis in localized NSCLC. The expression of p-EGFR, EGFR, and COX-2 was studied by immunohistochemistry in 77 surgically-resected stage I/II NSCLC cases. EGFR mutational status was determined by sequencing exons 18-21. Correlation of expression with clinical outcome and other biomarkers, including Ki-67 and microvessel density (MVD), was also examined.

RESULTS

Out of the 77 patients, EGFR overexpression was observed in 37 (48.1%), p-EGFR expression was found in 22 (28.6%), and COX-2 overexpression was seen in 45 (58.4%). Expression of p-EGFR was associated with COX-2 overexpression (P = 0.047), but not EGFR overexpression or high Ki-67 (P = 0.087 and P = 0.092, respectively). COX-2 overexpression was significantly associated with high Ki-67 (P = 0.011). Expression of p-EGFR correlated with lower disease-free survival (P = 0.045), but not overall survival. Neither EGFR nor COX-2 overexpression was associated with prognosis.

CONCLUSION

p-EGFR appears to be a better indicator for lower disease-free survival than EGFR overexpression itself in localized NSCLC. Pathways other than EGFR activation may influence COX-2 overexpression.

Basic evidence of molecular targeted therapy for oral cancer and salivary gland cancer

BACKGROUND

Recently, attention has been focused on molecular targeted cancer therapy in various tumors. Although there is no single consistent molecular target specific for oral squamous cell carcinoma (OSCC) and salivary gland cancer (SGC), there are a number of promising candidate proteins. The aim of this review is to introduce the basic evidences to support the molecular targeting for OSCC and SGC.

METHODS

We focused on the 4 molecules, epidermal growth factor receptor (EGFR), cyclooxygenase-2 (COX-2), peroxisome proliferator-activated receptor gamma (PPARgamma), and progesterone receptor, that are, respectively, associated with the proliferation and the differentiation of OSCC and SGC.

RESULTS

Gefitinib ("Iressa," ZD1839), a small molecule EGFR tyrosine kinase inhibitor, can inhibit the proliferation of OSCC cell lines in a dose- and time-dependent manner and lead to cell cycle arrest with accumulation of cells in the G1 phase, and a decrease of cells in S phase. The agent suppressed tumor metastasis in the animal model. Furthermore, a cooperative antiproliferative effect was obtained when cancer cells were treated with radiation followed by gefitinib. While radiation alone did not significantly affect p38 mitogen-activated protein kinase and MAP kinase kinase (MEK)1/2 autophosphorylation, the combination of gefitinib and radiation completely inhibited the downstream signaling of EGFR. Gefitinib enhanced tumor radioresponsiveness by multiple mechanisms, including the growth inhibition and effects on DNA repair after exposure to radiation. Next, the level of COX-2 expression correlated inversely with increased tumor radiation sensitivity. Treatment with celecoxib, a COX-2 selective inhibitor, enhanced the radioresponsiveness of HSC-2 cells, which constitutively expressed COX-2. Another promising molecular target is the PPARgamma, which is a member of the nuclear receptor superfamily of ligand-activated transcription factors. Recent studies have demonstrated that PPARgamma ligands induce cellular differentiation and inhibit cell growth in carcinomas of various types. These data suggest that synthetic PPARgamma ligands may be useful for molecular targeting of oral cancer. Finally, the possibility of using molecular targeted therapy directed at hormone receptors in the treatment of advanced SGCs was described.

CONCLUSION

The basic data strongly suggested the possibility of tumor suppression by targeting these molecules. Studies of different targeted agents alone or with more conventional treatment modalities are needed to fully determine what role the targeted therapy will play in the management of patients with OSCC and SGC.

EGFR gene copy number in adenocarcinoma of the lung by FISH analysis: investigation of significantly related factors on CT, FDG-PET, and histopathology

It has been suggested that a high EGFR gene copy number may be an indicator of good response to EGFR tyrosine kinase inhibitor therapy and a marker of poor prognosis in NSCLC. However, imaging features related to EGFR gene copy number status in adenocarcinoma are still unknown. We therefore retrospectively analyzed CT, FDG-PET, and histopathologic slides of surgical resected lung adenocarcinoma in 132 patients. Tumor characteristics on preoperative chest-CT, such as, GGO proportions, tumor diameters, and cavitation; FDG-PET SUV(max); and histopathologically determined differentiation degrees and tumor subtypes were evaluated. EGFR gene copy number status was categorized as FISH-positive or -negative. FISH-positivity was found in 53 patients (40.2%) and was significantly more frequent in tumors with a SUV(max)>7.0 (P=0.007). Furthermore, FISH-negativity was found to be more frequent in tumors with a GGO>50% (P=0.023) and diameter <15.5mm (P=0.006) on CT, or a well-differentiated histopathology (P=0.002). Moreover, the frequency of FISH-positivity increased as SUV(max) increased (P=0.0008) and as the proportion of GGO decreased (P=0.01). SUV(max)>7.0 was an independent predictor of FISH-positive results (odds ratio, 3.941; 95% CI, 1.691-9.182; P=0.01). In conclusion, a high SUV(max) on FDG-PET was significantly related to FISH-positive results. A high proportion of GGO, small tumor diameter on CT, and a well-differentiated histopathology were more frequent in FISH-negative adenocarcinomas.

The use of xenograft models for the selection of cancer treatments with the EGFR as an example

Mouse models of cancer have consistently been used to qualify new anti-cancer drugs for development of human clinical trials. The most used models are xenografts of human tumors grown subcutaneously in immunodeficient mice such as athymic (nude) or severe combined immune deficient (SCID) mice. However, the number of anti-cancer agents that fail in the clinic far outweighs those considered effective, suggesting that the selection procedure for progression of molecules into the clinic requires improvement. This has provoked considerable skepticism about the value of using such preclinical models. As a result, a shift has occurred towards developing and using spontaneous mouse tumor arising in transgenic and/or knockout mice engineered to recapitulate various genetic alterations thought to be causative of specific types of human cancers. Alternatively, the option has been to improve human tumor xenograft models by using orthotopic transplantation and, therefore, promotion of metastatic spread of the resultant 'primary' tumors. Here we review the value and the limitations of xenograft models and their role in developing new anti-cancer treatments.

Hypersensitivity reactions to biological drugs

OBJECTIVES

To review the current evidence regarding hypersensitivity reactions related to the administration of biological drugs in the management of cancer, and to provide the nurse with appropriate interventions related to the management of hypersensitivity reactions.

DATA SOURCES

Review articles and research studies from the medical and nursing literature.

CONCLUSION

Current evidence is available regarding the types of reactions that are associated with the administration of biological drugs in the management of cancer. Medical and nursing studies that review the most effective management of hypersensitivity reactions related to the administration of biological drugs. A review of "best practice" is offered in this article regarding the management of hypersensitivity reactions related to the administration of biological drugs.

IMPLICATIONS FOR NURSING PRACTICE

Nurses play a key role in the early identification of hypersensitivity reactions. Management of hypersensitivity reactions must be rapid for optimal patient outcomes.

Molecular changes of epidermal growth factor receptor (EGFR) and KRAS and their impact on the clinical outcomes in surgically resected adenocarcinoma of the lung

Recent studies have reported that clinical response to epidermal growth factor receptor (EGFR) inhibitors is associated with somatic changes of EGFR in the advanced stage of lung cancer. However, there is no clear data demonstrating whether such molecular changes of EGFR per se can affect the clinical outcome of early stage cancer after surgical resection. DNA mutations of EGFR and KRAS were investigated in 71 adenocarcinoma patients who received surgical resection. Fluorescence in situ hybridization (FISH) of EGFR gene amplification was performed in 48 samples. We detected EGFR mutations in 25 patients (35.2%). EGFR mutation was more frequently found in cases with BAC features (13/22 (59.1%):13/49 (26.5%); p=0.008) and in non-smokers (19/41 (46.3%):7/30 (23.3%); p=0.047). However, the EGFR mutation was not associated with age, gender, or clinical stage. The amplification of EGFR copy was frequently observed in the female gender (12/29 (41.4%):3/19 (15.8%); p=0.061) and in the advanced stage (> or =Stage IIIA, 9/19 (47.4%):6/29 (20.7%); p=0.051). KRAS mutations were present in five patients (7.0%) and none of them showed EGFR mutation. KRAS mutations (p=0.000), male gender (p=0.001), absence of BAC feature (p=0.003), advanced stage (p=0.039), and smoking history (p=0.030) were poor prognostic factors for overall survival, whereas EGFR mutation (p=0.184) and amplification (p=0.756) were not. The presence of EGFR mutation was not a prognostic factor of the clinical outcome of early lung cancer after surgical resection. This result provides an important message for the protocol design of future trials of EGFR inhibitors in early lung cancer. As the KRAS mutation was a poor prognostic factor and it presents reciprocally with EGFR mutation, KRAS mutation should be investigated in such trials. DNA mutations of EGFR and KRAS were investigated in 71 adenocarcinoma patients who received surgical resection. Whereas KRAS mutation was a poor prognostic factor, EGFR mutation was not, and its presence per se did not affect the clinical outcome of early lung cancer after surgical resection.

Insulin receptor substrate-1 involvement in epidermal growth factor receptor and insulin-like growth factor receptor signalling: implication for Gefitinib ('Iressa') response and resistance

Classically the insulin receptor substrate-1 (IRS-1) is an essential component of insulin-like growth factor type 1 receptor (IGF-IR) signalling, providing an interface between the receptor and key downstream signalling cascades. Here, however, we show that in tamoxifen-resistant MCF-7 (Tam-R) breast cancer cells, that are highly dependent on epidermal growth factor receptor (EGFR) for growth, IRS-1 can interact with EGFR and be preferentially phosphorylated on tyrosine (Y) 896, a Grb2 binding site. Indeed, phosphorylation of this site is greatly enhanced by exposure of these cells, and other EGFR-positive cell lines, to EGF. Importantly, while IGF-II promotes phosphorylation of IRS-1 on Y612, a PI3-K recruitment site, it has limited effect on Y896 phosphorylation in Tam-R cells. Furthermore, EGF and IGF-II co-treatment, reduces the ability of IGF-II to phosphorylate Y612, whilst maintaining Y896 phosphorylation, suggesting that the EGFR is the dominant recruiter of IRS-1 in this cell line. Significantly, challenge of Tam-R cells with the EGFR-selective tyrosine kinase inhibitor gefitinib, for 7 days, reduces IRS-1/EGFR association and IRS-1 Y896 phosphorylation, while promoting IRS-1/IGF-IR association and IRS-1 Y612 phosphorylation. Furthermore, gefitinib significantly enhances IGF-II-mediated phosphorylation of IRS-1 Y612 and AKT in Tam-R cells. Importantly, induction of this pathway by gefitinib can be abrogated by inhibition/downregulation of the IGF-IR. Our data would therefore suggest a novel association exists between the EGFR and IRS-1 in several EGFR-positive cancer cell lines. This association acts to promote phosphorylation of IRS-1 at Y896 and drive MAPK signalling whilst preventing recruitment of IRS-1 by the IGF-IR and inhibiting signalling via this receptor. Treatment with gefitinib alters the dynamics of this system, promoting IGF-IR signalling, the dominant gefitinib-resistant growth regulatory pathway in Tam-R cells, thus, potentially limiting its efficacy.

Small molecule signal transduction inhibitors for the treatment of solid tumors

A greater understanding of the pathogenesis of malignancy has led to the development of novel therapies designed to target aberrant molecular pathways that characterize and distinguish cancer cells from normal tissue. Small molecules are being designed to interfere with specific steps along the deregulated signaling cascade from the cytoplasmic membrane to the nucleus. Viable targets include growth factor receptors and their downstream second messengers, modulators of the cell cycle or apoptosis, regulators of protein trafficking and degradation, and transcription regulators. This review will discuss the small molecule signal transduction inhibitors in various stages of development and address the strategic issues relating to clinical trial design with these novel targeted agents.

In vitro responsiveness of glioma cell lines to multimodality treatment with radiotherapy, temozolomide, and epidermal growth factor receptor inhibition with cetuximab

BACKGROUND

The majority of glioblastoma multiforme (GBM) cells express the epidermal growth factor receptor (EGFR). The present study evaluates the combination of temozolomide (TMZ), EGFR inhibition, and radiotherapy (RT) in GBM cell lines.

METHODS AND MATERIALS

Human GBM cell lines U87, LN229, LN18, NCH 82, and NCH 89 were treated with various combinations of TMZ, RT, and the monoclonal EGFR antibody cetuximab. Responsiveness of glioma cells to the combination treatment was measured by clonogenic survival.

RESULTS

Overall, double and triple combinations of RT, TMZ, and cetuximab lead to additive cytotoxic effects (independent toxicity). A notable exception was observed for U87 and LN 18 cell lines, where the combination of TMZ and cetuximab showed substantial antagonism. Interestingly, in these two cell lines, the combination of RT with cetuximab resulted in a substantial increase in cell killing over that expected for independent toxicity. The triple combination with RT, cetuximab, and TMZ was nearly able to overcome the antagonism for the TMZ/cetuximab combination in U87, however only marginally in LN18, GBM cell lines.

CONCLUSION

It appears that EGFR expression is not correlated with cytotoxic effects exerted by cetuximab. Combination treatment with TMZ, cetuximab and radiation resulted in independent toxicity in three out of five cell lines evaluated, the antagonistic effect of the TMZ/cetuximab combination in two cell lines could indicate that TMZ preferentially kills cetuximab-resistant cells, suggesting for some cross-talk between toxicity mechanisms. Expression of EGFR was no surrogate marker for responsiveness to cetuximab, alone or in combination with RT and TMZ.

Dose scheduling of the dual VEGFR and EGFR tyrosine kinase inhibitor vandetanib (ZD6474, Zactima) in combination with radiotherapy in EGFR-positive and EGFR-null human head and neck tumor xenografts

PURPOSE

Vandetanib (ZD6474, Zactima) is a novel, orally available inhibitor of vascular endothelial growth factor receptor-2 (VEGFR2) tyrosine kinase activity with additional activity against epidermal growth factor receptor (EGFR) tyrosine kinase. Vandetanib has demonstrated enhanced efficacy in combination with radiation therapy (RT) in human tumor models. This study aimed to evaluate the schedule-dependent interaction of clinically relevant dosing of vandetanib with RT in human head and neck cancer models that had been characterized as EGFR positive (EGFR+) or negative (EGFR-) in order to begin differentiating vandetanib and RT interactions at the level of antitumor (EGFR) or antivascular (VEGFR2) activities.

METHODS

The human head and neck squamous cell carcinoma (HNSCC) cell lines UMSCC2 (EGFR+) and UMSCC10 (EGFR(-)) are sensitive and resistant to EGFR inhibitors, respectively, while having similar sensitivity to ionizing radiation. Nude mice with UMSCC2 or UMSCC10 tumor xenografts were treated with vandetanib or RT alone, or with combinations of concomitant and sequential therapy. Vandetanib was dosed at 30 mg kg(-1) day(-1) based on pharmacokinetic studies in nude mice showing that this dose results in drug exposure similar to that seen in humans at clinical doses. RT was dosed at 3 Gy twice a week for two consecutive weeks for a total dose of 12 Gy.

RESULTS

Vandetanib alone caused regression in EGFR+ but not EGFR- tumors and RT therapy alone was similar in both tumor types. Combinations of vandetanib and RT showed concomitant use of vandetanib and RT was superior to RT followed by vandetanib or visa versa in EGFR- tumors. Therapeutic response of EGFR+ tumors was similar regardless of treatment sequencing.

CONCLUSIONS

The combination of vandetanib and RT is active in both EGFR+ and EGFR- HNSCC tumor xenografts, however, vandetanib alone is only active in EGFR+ xenografts. EGFR+ tumor response to vandetanib and RT was independent of treatment sequencing, but concomitant treatment was superior to sequencing in EGFR- tumors. These results suggest that the anti-VEGFR2 antitumor activity of vandetanib is enhanced by RT as presumably the activity seen in EGFR- tumors is due to antiangiogenic activity, whereas the anti-EGFR antitumor activity dominates in EGFR+ tumors such that RT enhancement is not observed.

Radiation-induced cell signaling: inside-out and outside-in

Exposure of tumor cells to clinically relevant doses of ionizing radiation causes DNA damage as well as mitochondria-dependent generation of reactive oxygen species. DNA damage causes activation of ataxia telangiectasia mutated and ataxia telangiectasia mutated and Rad3-related protein, which induce cell cycle checkpoints and also modulate the activation of prosurvival and proapoptotic signaling pathways, such as extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun NH(2)-terminal kinase 1/2, respectively. Radiation causes a rapid reactive oxygen species-dependent activation of ERBB family and other tyrosine kinases, leading to activation of RAS proteins and multiple protective downstream signaling pathways (e.g., AKT and ERK1/2), which alter transcription factor function and the apoptotic threshold of cells. The initial radiation-induced activation of ERK1/2 can promote the cleavage and release of paracrine ligands, which cause a temporally delayed reactivation of receptors and intracellular signaling pathways in irradiated and unirradiated bystander cells. Hence, signals from within the cell can promote activation of membrane-associated receptors, which signal back into the cytosol: signaling from inside the cell outward to receptors and then inward again via kinase pathways. However, cytosolic signaling can also cause release of membrane-associated paracrine factors, and thus, paracrine signals from outside of the cell can promote activation of growth factor receptors: signaling from the outside inward. The ultimate consequence of these signaling events after multiple exposures may be to reprogram the irradiated and affected bystander cells in terms of their expression levels of growth-regulatory and cell survival proteins, resulting in altered mitogenic rates and thresholds at which genotoxic stresses cause cell death. Inhibition of signaling in one and/or multiple survival pathways enhances radiosensitivity. Prolonged inhibition of any one of these pathways, however, gives rise to lineages of cells, which have become resistant to the inhibitor drug, by evolutionary selection for the clonal outgrowth of cells with point mutations in the specific targeted protein that make the target protein drug resistant or by the reprogramming of multiple signaling processes within all cells, to maintain viability. Thus, tumor cells are dynamic with respect to their reliance on specific cell signaling pathways to exist and rapidly adapt to repeated toxic challenges in an attempt to maintain tumor cell survival.

Technology insight: pharmacoproteomics for cancer--promises of patient-tailored medicine using protein microarrays

Patient-tailored medicine can be defined as the selection of specific therapeutics to treat disease in a particular individual based on genetic, genomic or proteomic information. While individualized treatments have been used in medicine for years, advances in cancer treatment have now generated a need to more precisely define and identify those patients who will derive the most benefit from new-targeted agents. Cellular signaling pathways are a protein-based network, and the intended drug effect is to disrupt aberrant protein phosphorylation-based enzymatic activity and epigenetic phenomena. Pharmacoproteomics, or the tailoring of therapy based on proteomic knowledge, will begin to take a central role in this process. A new type of protein array platform, the reverse-phase protein microarray, shows potential for providing detailed information about the state of the cellular 'circuitry' from small samples such as patient biopsy specimens. Measurements of hundreds of specific phosphorylated proteins that span large classes of important signaling pathways can be obtained at once from only a few thousand cells. Clinical implementation of these new proteomic tools to aid the clinical, medical and surgical oncologist in making decisions about patient care will now require thoughtful communication between practicing clinicians and research scientists.

Gefitinib is effective against juvenile pilocytic astrocytoma in vitro

BACKGROUND

Juvenile pilocytic astrocytomas (JPAs) are the most common central nervous system tumors in children. If completely resected, JPAs are associated with an excellent outcome. However, there is need for additional therapeutic approaches for those JPAs which are incompletely resected and fail subsequent standard chemotherapy/radiation. To explore the possibility for a novel therapeutic approach we measured the effect of the epidermal growth factor receptor (EGFR) small molecule tyrosine kinase inhibitor gefitinib on five JPA primary cell-cultures.

PROCEDURE

Due to a lack of established cell-lines of JPA very few in vitro drug sensitivity assays have been performed. In this study we have succeeded in propagating short-term primary cell-cultures established from surgical specimens. The effect of gefitinib on proliferation in JPA derived primary cell-cultures was measured by a standard tritiated thymidine incorporation assay. The level of expression of EGFR, the intended target of gefitinib, was measured by immunohistochemistry, flow cytometry and RT-PCR.

RESULTS

Gefitinib was shown to inhibit proliferation in all five JPA cell-cultures tested, with IC-50's between 1.6 and 9.6 microM. However, EGFR protein and mRNA expression was undetectable. Further studies with cetuximab, an EGFR-specific inhibitory monoclonal antibody, showed no effect on proliferation in JPA.

CONCLUSIONS

Based on these preclinical data, gefitinib may be a suitable salvage chemotherapy drug to explore further in those patients with JPA who have recurred after primary chemotherapy. Of interest, it appears that the anti-tumor effect of gefitinib in JPA cell-cultures may be mediated through a pathway other than EGFR inhibition.

Targeting of EGFR tyrosine kinase by ZD1839 ("Iressa") in androgen-responsive prostate cancer in vitro

EGFR, highly expressed in a variety of human malignancies, is correlated with poor tumour differentiation, high tumour growth and metastatic rate. EGF and several other ligands, such as transforming growth factor-alpha, amphiregulin, heparin-binding EGF, and betacellulin, activate Ras/Raf mitogen-activated protein kinases (MAPKs) and phosphatidyl inositol 3'-kinase (PI3K)/Akt signalling pathways. Therefore, EGFR can regulate multiple processes, i.e., gene expression, cellular proliferation, angiogenesis, and inhibition of apoptosis, which contribute to the development of malignancy. In this review, we discuss the inhibition of EGFR by the specific tyrosine kinase inhibitor Iressa (ZD1839) focusing on its effects in prostate cancer.

Treatment of non-small cell lung cancer with intensity-modulated radiation therapy in combination with cetuximab: the NEAR protocol (NCT00115518)

BACKGROUND

Even today, treatment of Stage III NSCLC still poses a serious challenge. So far, surgical resection is the treatment of choice. Patients whose tumour is not resectable or who are unfit to undergo surgery are usually referred to a combined radio-chemotherapy. However, combined radio-chemotherapeutic treatment is also associated with sometimes marked side effects but has been shown to be more efficient than radiation therapy alone. Nevertheless, there is a significant subset of patients whose overall condition does not permit administration of chemotherapy in a combined-modality treatment. It could be demonstrated though, that NSCLCs often exhibit over-expression of EGF-receptors hence providing an excellent target for the monoclonal EGFR-antagonist cetuximab (Erbitux) which has already been shown to be effective in colorectal as well as head-and-neck tumours with comparatively mild side-effects.

METHODS/DESIGN

The NEAR trial is a prospective phase II feasibility study combining a monoclonal EGF-receptor antibody with loco-regional irradiation in patients with stage III NSCLC. This trial aims at testing the combination's efficacy and rate of development of distant metastases with an accrual of 30 patients. Patients receive weekly infusions of cetuximab (Erbitux) plus loco-regional radiation therapy as intensity-modulated radiation therapy. After conclusion of radiation treatment patients continue to receive weekly cetuximab for 13 more cycles.

DISCUSSION

The primary objective of the NEAR trial is to evaluate toxicities and feasibility of the combined treatment with cetuximab (Erbitux) and IMRT loco-regional irradiation. Secondary objectives are remission rates, 3-year-survival and local/systemic progression-free survival.

Chemopreventive effects of cyclooxygenase-2 inhibitor and epidermal growth factor-receptor kinase inhibitor on rat urinary bladder carcinogenesis

OBJECTIVE

To examine the chemopreventive effects of a selective cyclooxygenase (COX)-2 inhibitor, meloxicam, and a selective epidermal growth factor (EGF)-receptor tyrosine kinase inhibitor, gefitinib (as a single agent) on a carcinogen-induced rodent bladder carcinogenesis model.

MATERIALS AND METHODS

The study comprised 103 male Fisher-344 rats (8 weeks old); after initial carcinogen treatment for 8 weeks with 0.05%N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in drinking water, the rats were divided into five groups, i.e. group 1, control (vehicle only); group 2, gefitinib high-dose (15 mg/kg by gavage once daily); group 3, gefitinib low-dose (5 mg/kg); group 4, meloxicam high-dose (1.8 mg/kg by gavage once daily); and group 5, meloxicam low-dose (0.6 mg/kg). Twelve weeks later the rats were killed; after fixing the bladder in 10% formalin, the number and size of hyperplasia and carcinoma foci were recorded microscopically in sections stained with haematoxylin and eosin, submitted entirely as multiple strips.

RESULTS

The incidence of carcinoma, confirmed microscopically, was: control 14/20 (70%); high-dose gefitinib, 7/20 (35%); low-dose gefitinib, 7/20 (35%); high-dose meloxicam 7/21 (33%); and low-dose meloxicam, 12/20 (60%). The mean numbers of carcinomas per bladder in groups 1-5 were 1.2, 0.5, 0.4, 0.5 and 1.1, respectively. The incidence and the mean number of carcinomas per bladder were significantly lower in the treatment groups (P < 0.05) than in the control group, except in the low-dose meloxicam group. There were no significant adverse effects.

CONCLUSION

Both meloxicam and gefitinib have inhibitory effects on rat bladder carcinogenesis with no significant adverse effects. A combination of these drugs would be worth studying for their synergistic effects.

Increased toxicity with gefitinib, capecitabine, and radiation therapy in pancreatic and rectal cancer: phase I trial results

PURPOSE

Overexpression of epidermal growth factor receptor (EGFR) has been associated with aggressive tumor phenotypes, chemotherapy, and radiation resistance, as well as poor survival in preclinical and clinical models. The EGFR inhibitor gefitinib potentiates chemotherapy and radiation tumor cytotoxicity in preclinical models, including pancreatic and colorectal cancer. We initiated two phase I trials assessing the combination of gefitinib, capecitabine, and radiation in patients with localized pancreatic and rectal cancer.

PATIENTS AND METHODS

Patients with pathologically confirmed adenocarcinoma of the pancreas and rectum were eligible. Pretreatment staging included computed tomography, endoscopic ultrasound, and surgical evaluation. Patients received 50.4 Gy of external-beam radiation therapy to the tumor in 28 fractions. Capecitabine and gefitinib were administered throughout the radiation course. Following completion, patients were restaged and considered for resection. Primary end points included determination of dose-limiting toxicity (DLT) and a phase II dose; secondary end points included determination of non-DLTs and preliminary radiographic and pathologic response rates.

RESULTS

Ten patients were entered in the pancreatic study and six in the rectal study. DLT was seen in six of 10 patients in the pancreatic study and two of six patients in the rectal study. The primary DLT in both studies was diarrhea. Two patients developed arterial thrombi.

CONCLUSION

The combination of gefitinib, capecitabine, and radiation in pancreatic and rectal cancer patients resulted in significant toxicity. A recommended phase II dose was not determined in either of our studies. Further investigation with this combination should be approached with caution.

Chemoradiotherapy for lung cancer

Chemoradiotherapy is a standard treatment for both unresectable locally advanced non-small cell lung cancer and limited-stage small cell lung cancer. Cisplatin-based chemotherapy with concurrent thoracic radiotherapy yields a 5-year survival rate of approximately 15% for patients with unresectable locally advanced non-small cell lung cancer. The state-of-the-art treatment for limited-stage small cell lung cancer is four cycles of chemotherapy with cisplatin plus etoposide combined with early concurrent twice-daily thoracic irradiation and prophylactic cranial irradiation after complete remission. A 5-year survival rate of approximately 25% is expected among patients treated for limited-stage small cell lung cancer. The incorporation of new agents, including target-based drugs, is one of the most promising strategies for improving the survival of patients.