Concurrent use of vinorelbine and gefitinib induces supra-additive effect in head and neck squamous cell carcinoma cell lines

Caffeic Acid Phenethyl Ester Inhibits the Proliferation of HEp2 Cells by Regulating Stat3/Plk1 Pathway and Inducing S Phase Arrest

Caffeic acid phenethyl ester (CAPE), an active polyphenolic component of honeybee propolis, has been demonstrated to have many medicinal properties. However, the antitumor effect and mechanism of CAPE on laryngeal carcinoma cells have not been examined. In this study, we treated HEp2 cells with various concentration of CAPE, and the results showed that CAPE can reduce the viability of HEp2 cells with IC50 values of 23.8 ± 0.7 µM for 72 h. Meanwhile, CAPE significantly inhibited activation of signal transducer and activator of transcription (Stat)3 in a concentration dependent manner in HEp2 cells and regulated the expression and transcription of Plk1. AG490, a specific Stat3 inhibitor, not only inhibited the activation and expression of Stat3, but also inhibited the expression of Plk1 in HEp2 cells, so Stat3 was probably involved in the regulation of Plk1 in HEp2 cells. In addition, treatment of CAPE leaded to a blockage of cell cycle in S phase in HEp2 cells. Therefore, CAPE inhibited the proliferation of HEp2 Cells probably by regulating Stat3/Plk1 pathway and inducing S phase arrest.

Confirmation of Selected Synergistic Cancer Drug Combinations Identified in an HTS Campaign and Exploration of Drug Efflux Transporter Contributions to the Mode of Synergy

Systematic unbiased high-throughput screening (HTS) of drug combinations (DCs) in well-characterized tumor cell lines is a data-driven strategy to identify novel DCs with potential to be developed into effective therapies. Four DCs from a DC HTS campaign were selected for confirmation; only one appears in clinicaltrials.gov and limited preclinical in vitro data indicates that the drug pairs interact synergistically. Nineteen DC-tumor cell line sets were confirmed to interact synergistically in three pharmacological interaction models. We developed an imaging assay to quantify accumulation of the ABCG2 efflux transporter substrate Hoechst. Gefitinib and raloxifene enhanced Hoechst accumulation in ABCG2 (BCRP)-expressing cells, consistent with inhibition of ABCG2 efflux. Both drugs also inhibit ABCB1 efflux. Mitoxantrone, daunorubicin, and vinorelbine are substrates of one or more of the ABCG2, ABCB1, or ABCC1 efflux transporters expressed to varying extents in the selected cell lines. Interactions between ABC drug efflux transporter inhibitors and substrates may have contributed to the observed synergy; however, other mechanisms may be involved. Novel synergistic DCs identified by HTS were confirmed in vitro, and plausible mechanisms of action studied. Similar approaches may justify the testing of novel HTS-derived DCs in mouse xenograft human cancer models and support the clinical evaluation of effective in vivo DCs in patients.

Development and characterisation of acquired radioresistant breast cancer cell lines

BACKGROUND

Radiotherapy plays an important role in the multimodal treatment of breast cancer. The response of a breast tumour to radiation depends not only on its innate radiosensitivity but also on tumour repopulation by cells that have developed radioresistance. Development of effective cancer treatments will require further molecular dissection of the processes that contribute to resistance.

METHODS

Radioresistant cell lines were established by exposing MDA-MB-231, MCF-7 and ZR-751 parental cells to increasing weekly doses of radiation. The development of radioresistance was evaluated through proliferation and colony formation assays. Phenotypic characterisation included migration and invasion assays and immunohistochemistry. Transcriptomic data were also generated for preliminary hypothesis generation involving pathway-focused analyses.

RESULTS

Proliferation and colony formation assays confirmed radioresistance. Radioresistant cells exhibited enhanced migration and invasion, with evidence of epithelial-to-mesenchymal-transition. Significantly, acquisition of radioresistance in MCF-7 and ZR-751 cell lines resulted in a loss of expression of both ERα and PgR and an increase in EGFR expression; based on transcriptomic data they changed subtype classification from their parental luminal A to HER2-overexpressing (MCF-7 RR) and normal-like (ZR-751 RR) subtypes, indicating the extent of phenotypic changes and cellular plasticity involved in this process. Radioresistant cell lines derived from ER+ cells also showed a shift from ER to EGFR signalling pathways with increased MAPK and PI3K activity.

CONCLUSIONS

This is the first study to date that extensively describes the development and characterisation of three novel radioresistant breast cancer cell lines through both genetic and phenotypic analysis. More changes were identified between parental cells and their radioresistant derivatives in the ER+ (MCF-7 and ZR-751) compared with the ER- cell line (MDA-MB-231) model; however, multiple and likely interrelated mechanisms were identified that may contribute to the development of acquired resistance to radiotherapy.

Implementation of the NCI-60 Human Tumor Cell Line Panel to Screen 2260 Cancer Drug Combinations to Generate >3 Million Data Points Used to Populate a Large Matrix of Anti-Neoplastic Agent Combinations (ALMANAC) Database

Animal and clinical studies demonstrate that cancer drug combinations (DCs) are more effective than single agents. However, it is difficult to predict which DCs will be more efficacious than individual drugs. Systematic DC high-throughput screening (HTS) of 100 approved drugs in the National Cancer Institute's panel of 60 cancer cell lines (NCI-60) produced data to help select DCs for further consideration. We miniaturized growth inhibition assays into 384-well format, increased the fetal bovine serum amount to 10%, lengthened compound exposure to 72 h, and used a homogeneous detection reagent. We determined the growth inhibition 50% values of individual drugs across 60 cell lines, selected drug concentrations for 4 × 4 DC matrices (DCMs), created DCM master and replica daughter plate sets, implemented the HTS, quality control reviewed the data, and analyzed the results. A total of 2620 DCMs were screened in 60 cancer cell lines to generate 3.04 million data points for the NCI ALMANAC (A Large Matrix of Anti-Neoplastic Agent Combinations) database. We confirmed in vitro a synergistic drug interaction flagged in the DC HTS between the vinca-alkaloid microtubule assembly inhibitor vinorelbine (Navelbine) tartrate and the epidermal growth factor-receptor tyrosine kinase inhibitor gefitinib (Iressa) in the SK-MEL-5 melanoma cell line. Seventy-five percent of the DCs examined in the screen are not currently in the clinical trials database. Selected synergistic drug interactions flagged in the DC HTS described herein were subsequently confirmed by the NCI in vitro, evaluated mechanistically, and were shown to have greater than single-agent efficacy in mouse xenograft human cancer models. Enrollment is open for two clinical trials for DCs that were identified in the DC HTS. The NCI ALMANAC database therefore constitutes a valuable resource for selecting promising DCs for confirmation, mechanistic studies, and clinical translation.

Dual targeting of EGFR and ERBB2 pathways produces a synergistic effect on cancer cell proliferation and migration in vitro

Members of the epidermal growth factor receptor (EGFR/ERBB) gene family are frequently dysregulated in a range of human cancers, and therapeutics targeting these proteins are in clinical use. We hypothesized that similar pathways are involved in feline and canine tumours and that the same drugs may be of clinical use in veterinary patients. We investigated EGFR and ERBB2 targeting using a panel of feline and canine cell lines. EGFR and ERBB2 were targeted with siRNAs or tyrosine kinase inhibitors (TKIs) and their effect on cellular proliferation, colony formation and migration was investigated in vitro. Here we report that EGFR and ERBB2 combined siRNA targeting produced synergistic effects in feline and canine cell lines similar to that reported in human cell lines. We conclude that dual EGFR and ERBB2 targeting using TKIs should be further evaluated as a potential new therapeutic strategy in feline head and neck and mammary tumours and canine mammary tumours.

Phase I Study of Oral Vinorelbine in Combination with Erlotinib in Advanced Non-Small Cell Lung Cancer (NSCLC) Using Two Different Schedules

Purpose

This study aimed to evaluate the safety, tolerability and pharmacokinetics of the combination of oral vinorelbine with erlotinib using the conventional (CSV) and metronomic (MSV) dosing schedules in patients with advanced non-small cell lung cancer (NSCLC).

Methods

This was an open-label, multiple dose-escalation phase I study. An alternating 3+3 phase I design was employed to allow each schedule to enroll three patients sequentially at each dose level. Thirty patients with Stage IIIB/IV NSCLC were treated with escalating doses of oral vinorelbine starting at 40 mg/m² on day 1 and 8 in the CSV group (N = 16) and at 100 mg/week in the MSV group (N = 14). Erlotinib was administered orally daily.

Results

The maximum tolerated dose was vinorelbine 80 mg/m² with erlotinib 100 mg in the CSV group and vinorelbine 120 mg/week with erlotinib 100 mg in the MSV group. Grade 3/4 toxicities included neutropenia (N = 2; 13%) and hyponatremia (N = 1; 6%) in the CSV group, and neutropenia (N = 5; 36%) in the MSV group. Objective response was achieved in 38% and 29% in the CSV and MSV groups respectively. Vinorelbine co-administration did not significantly affect the pharmacokinetics of erlotinib and OSI-420 after initial dose. However, at steady-state, significantly higher C_max, higher C_min and lower CL/F of erlotinib were observed with increasing dose levels of vinorelbine in the CSV group. Significantly higher steady-state C_min, C_avg and AUC_ss of erlotinib were observed with increasing dose levels of vinorelbine in the MSV group.

Conclusions

Combination of oral vinorelbine with erlotinib is feasible and tolerable in both the CSV and MSV groups.

Trial Registration

ClinicalTrials.gov NCT00702182

Sequential use of vinorelbine followed by gefitinib enhances the antitumor effect in NSCLC cell lines poorly responsive to reversible EGFR tyrosine kinase inhibitors

Preclinical studies have suggested that combining cytotoxic agents with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) to treat EGFR-mutated tumors may increase their inhibitory effect depending on the order of drug administration. The antitumor efficacy of different treatment sequences using vinorelbine (VNB) and gefitinib (GEF) was investigated both in vitro and in vivo in non-small cell lung cancer (NSCLC) cell lines with the rationale of potentially translating these findings into the clinical setting. The EGFR-wild-type A549 and the EGFR-mutated (exon 21 L858R/exon 20 T790M) H1975 cell lines were treated as follows: GEF followed by VNB, VNB followed by GEF and the two drugs applied individually or concurrently. Results in vitro demonstrated that the sequence of VNB followed by GEF was significantly more active than single-agent treatments. The expression of activated EGFR and its downstream pathway genes indicated that the increased cytotoxic effect of the VNB and GEF treatment sequence was accompanied by inhibition of EGFR, AKT and ERK1/2. Moreover, the increased inhibition of tumor growth after treatment with VNB followed by GEF was also confirmed in CD1-nude mice that were xenotransplanted with H1975 cells (p < 0.0001). This effect was paralleled by a corresponding decrease in cancer glucose consumption, as assessed by micro-positron emission tomography scans (p < 0.05). These preclinical findings in NSCLC cell lines, which are poorly responsive to EGFR-TKIs, demonstrated that the sequential treatment of VNB followed by GEF induced a significant antitumor effect, which supports the translation of this treatment schedule into a clinical setting.

Safety of triazole antifungal drugs in patients with cancer

Triazole drugs are widely used in cancer patients for prophylaxis and treatment of life-threatening invasive fungal infections. Fluconazole, available for over two decades, is safe and effective in patients with cancer; however, the excellent safety profile of fluconazole may not be applicable to the newer triazoles. Itraconazole, voriconazole and posaconazole are associated with adverse events, and drug interactions frequently occur, particularly in cancer patients, since the triazoles and many drugs used in cancer chemotherapy are metabolized via a common metabolic pathway, the hepatic cytochrome P450 system. Close monitoring for drug interactions is needed when triazoles are used with anti-neoplastic drugs and dosage modification of the triazole or its discontinuation may be required. Monitoring of triazole serum concentrations is becoming an important aspect of management to minimize toxicity and ensure efficacy.

MASPIN's prognostic role in patients with advanced head and neck carcinoma treated with primary chemotherapy (carboplatin plus vinorelbine) and radiotherapy: preliminary evidence

CONCLUSIONS

Our very preliminary results support the hypothesis that MASPIN expression in primary head and neck squamous cell carcinoma (HNSCC) may be a valuable parameter for predicting patients' responses to a treatment based on carboplatin plus vinorelbine combined with radiotherapy.

OBJECTIVES

The roles of induction chemotherapy and combined chemoradiotherapy in the treatment of locally advanced unresectable HNSCCs have evolved rapidly. MASPIN has a unique tumour-suppressing activity. Experimental evidence has shown that MASPIN suppresses tumour growth, angiogenesis, invasion and metastasis. We investigated the potential prognostic roles of MASPIN and p53 in a series of HNSCCs treated with carboplatin plus vinorelbine combined with radiotherapy.

PATIENTS AND METHODS

Nineteen consecutive stage III or IV HNSCC patients were recruited. The treatment plan consisted of the administration of carboplatin on day 1 and vinorelbine on days 1 and 8. Four weeks later, carboplatin was administered concomitantly with radiation therapy. Expression of MASPIN and p53 was determined immunohistochemically in HNSCC diagnostic biopsies.

RESULTS

A significant inverse relation was found between MASPIN expression and cN staging (p = 0.003). From a prognostic viewpoint, MASPIN expression was directly correlated with chemoradiotherapy response (p = 0.041). Moreover, the log-rank test showed a significant relationship between higher MASPIN expression and longer disease-free survival (p = 0.03), overall survival (p = 0.006) and disease-specific survival (p = 0.007).