Pharmacogenomic strategies for developing customized chemotherapy in non-small cell lung cancer

Quercetin Inhibits the Proliferation and Metastasis of Human Non-Small Cell Lung Cancer Cell Line: The Key Role of Src-Mediated Fibroblast Growth Factor-Inducible 14 (Fn14)/ Nuclear Factor kappa B (NF-κB) pathway

Background

Quercetin (Que) is reported to induce apoptosis of lung cancer cells. Src is closely related to the progression of non-small cell lung cancer (NSCLC) and can be modulated by Que in macrophages. In the current study, the interaction between Que and Src signaling in NSCLC cells was explored to explain the anti-NSCLC function of Que.

Material/Methods

NSCLC cell line HCC827 was subjected to the administrations of Que at different concentrations. The effect of Que on tumor cell proliferation was detected using MTT and colony formation assays. Then the effect on the migration and invasion abilities was assessed using scratch and Transwell assays. At molecular level, the changes in Src/Fn14/NF-κB signaling were determined using western blotting assays. The role of Src in the function of Que was further explored by inducing the expression of Src gene in NSCLC cells before Que administration. The results of the in vitro assays were verified using a NSCLC mice model.

Results

Que inhibited the proliferation and anchorage-independent growth of NSCLC cells. Additionally, Que delayed in the gap closure rate in scratch assays and decreased the membrane-penetrating cell number in Transwell assays. At a molecular level, Que suppressed the expression of Src, which subsequently inhibited Fn14/NF-κB signaling. In in vivo assays, Que inhibited the growth of solid tumors. After the overexpression of Src in NSCLC cells, the anti-NSCLC effect of Que was blocked by inducing NSCLC proliferation and metastasis, and by activating Fn14/NF-κB signaling. Moreover, the induced level of Src promoted the growth and metastasis potential of solid tumors in mice.

Conclusions

Que exerted the anti-NSCLC effect by inhibiting Src-mediated Fn14/NF-κB pathway both in vitro and in vivo.

Src Promotes Metastasis of Human Non-Small Cell Lung Cancer Cells through Fn14-Mediated NF-κB Signaling

Background

Src and Fn14 are implicated in the aggressiveness of non-small cell lung cancer (NSCLC) cells, yet the molecular mechanism is not fully understood.

Material/Methods

The proliferation, migration, and invasion of HCC827 cells with Src knockdown were examined in vitro. The expression of Fn14 and the activation of NF-κB signaling pathway in Src-silenced HCC827 cells were detected by western blot. The role of Fn14 in Src-regulated cell migration/invasion and activation of NF-κB signaling was investigated by overexpressing Fn14 in Src knockdown NSCLC cells. Furthermore, the pro-metastatic role of Src was validated in a NSCLC metastasis mouse model.

Results

Knockdown of Src inhibited the proliferation, migration, and invasion of HCC827 cells, which was associated with reduced levels of Fn14, p-IκBα, p-IKKβ, and nuclear NF-κB p65. Overexpression of Fn14 restored the potential of migration and invasion as well as the activation of NF-κB signaling in Src-silenced NSCLC cells. In addition, silencing of Src suppressed lung metastasis of HCC827 cells in mice, and inhibited the expression of Fn14 and nuclear translocation of NF-κB p65 in vivo.

Conclusions

The data demonstrated that the Src/Fn14/NF-κB axis plays a critical role in NSCLC metastasis.

Nucleolin-Targeting AS1411-Aptamer-Modified Graft Polymeric Micelle with Dual pH/Redox Sensitivity Designed To Enhance Tumor Therapy through the Codelivery of Doxorubicin/TLR4 siRNA and Suppression of Invasion

In this article, a novel graft polymeric micelle with targeting function ground on aptamer AS1411 was synthesized. The micelle was based on chitosan-ss-polyethylenimine-urocanic acid (CPU) with dual pH/redox sensitivity and targeting effects. This micelle was produced for codelivering Toll-like receptor 4 siRNA (TLR4-siRNA) and doxorubicin (Dox). In vitro investigation revealed the sustained gene and drug release from Dox-siRNA-loaded micelles under physiological conditions, and this codelivery nanosystem exhibited high dual pH/redox sensitivity, rapid intracellular drug release, and improved cytotoxicity against A549 cells in vitro. Furthermore, the micelles loaded with TLR4-siRNA inhibited the migration and invasion of A549. Excellent tumor penetrating efficacy was also noted in the A549 tumor spheroids and solid tumor slices. In vivo, multiple results demonstrated the excellent tumor-targeting ability of AS1411-chitosan-ss-polyethylenimine-urocanic acid (ACPU) micelle in tumor tissues. The micelles exhibited excellent antitumor efficacy and low toxicity in the systemic circulation in lung-tumor-bearing BALB/c mice. These results conclusively demonstrated the great potential of the new graft copolymer micelle with targeting function for the targeted and efficient codelivery of chemotherapeutic drugs and genes in cancer treatment.

IL-6 and TNF-α promote metastasis of lung cancer by inducing epithelial-mesenchymal transition

The characteristics of cancer cells, such as invasiveness, are affected by the tumor microenvironment. Studies have shown that interleukin (IL)-6 and tumor necrosis factor (TNF)-α regulate the proliferation of lung cancer. However, few studies have focused on the effects of IL-6 and TNF-α on metastasis of lung cancer. The present study was designed to investigate whether IL-6 and TNF-α can promote metastasis of non-small cell lung cancer (NSCLC). Sixty-five tumor and matched adjacent tissue samples from patients with NSCLC and corresponding serum samples were collected. Thirty serum samples from healthy subjects were selected as controls. Real-time PCR and western blot analysis were used to measure IL-6, TNF-α, vimentin, E-cadherin, and N-cadherin expression in tissue samples; ELISA was used to measure IL-6 and TNF-α expression in serum samples. The correlation of serum levels of IL-6 and TNF-α with the clinical stage was analyzed; the correlation of IL-6 and TNF-α levels in serum with these tissues was analyzed; the correlation of serum levels of IL-6 and TNF-α with lymph node metastasis and distant metastasis was analyzed. Expression of IL-6 and TNF-α were significantly increased compared with controls in both serum and tissue; IL-6 and TNF-α levels were positively correlated with lymph node metastasis and distant metastasis; IL-6 and TNF-α levels were negatively correlated with E-cadherin level and were positively correlated with N-cadherin and vimentin levels. In conclusion, IL-6 and TNF-α can induce epithelial-mesenchymal transition, and subsequently promote metastasis of lung cancer. Anti-inflammation should be considered for the treatment of lung cancer.

ERCC1, RRM1 and TUBB3 mRNA expression on the tumor response and overall survival of non-small cell lung cancer treated with platinum-based chemotherapy

Objective: We aimed to analyze the expression of ERCC1, RRM1 and TUBB3 in 305 patients with advanced non-small cell lung cancer (NSCLC) and investigate whether these genes can be used as biomarkers for predicting tumor response and clinical outcome.

Methods: Total 305 patients with unresectable and locally advanced NSCLC were collected between January 2007 and December 2008. cDNA of ERCC1, RRM1 and TUBB3 was isolated by a fluorescence-based real-time detection method.

Results: All the patients were followed up until December 2012. One hundred seventy five patients showed good response and 130 patients showed poor response to chemotherapy. 126 patients died and 166 patients showed progressive disease during the follow-up period. The median levels of ERCC1, RRM1 and TUBB3 mRNA were 0.53±0.13, 0.31±0.15 and 0.18±0.16, respectively. We found that patients with low ERCC1 expression showed a significantly higher rate of good tumor response, and the adjusted OR (95% CI) was 2.16(1.32-3.45). By Cox regression analysis. We also found that low ERCC1 expression level were correlated with longer overall survival of NSCLC patients, with the adjusted HR (95% CI) was 2.15 (1.26–3.35).

Conclusion: This study showed that ERCC1 mRNA expression can not affect the response to chemotherapy and clinical outcome of advanced non-small cell lung cancer (NSCLC) patients.

A prospective study of biomarker-guided chemotherapy in patients with non-small cell lung cancer

PURPOSE

To assess the therapeutic value of biomarker-guided chemotherapy in patients with advanced non-small cell lung cancer (NSCLC).

METHODS

Eighty-five NSCLC patients at stage IIIb or IV were divided into two groups based on the feasibility of biomarker analysis. Group A included patients with biomarker data (n = 41); Group B were patients without biomarker results (n = 44). Tumor samples obtained by fiberoptic bronchoscopy and computerized tomography-guided needle biopsy were analyzed by immunohistochemistry for intratumoral level of excision repair cross-complementing gene 1 (ERCC1), ribonucleotide reductase M1 (RRM1), and β-tubulin III. Chemotherapy regimens in Group A were determined according to the status of molecular signatures, whereas a standard gemcitabine plus cisplatin regimen was used for Group B. Tumor response, patient survival, and adverse effects were monitored for both groups.

RESULTS

The overall response rate, defined as complete response plus partial response, was 56.1% for Group A, significantly higher than that in Group B (31.8%; P = 0.024). The median progression-free survival (PFS) time was 5.2 months for Group A, significantly longer than that of Group B (4.1 months; P = 0.026). The 1-year survival rate of Group A was 65.9%, significantly higher than that of Group B (40.9%; P = 0.021), whereas the median overall survival times were 13.5 versus 12.5 months for Groups A and B, respectively (P = 0.483). The adverse effects in the two groups were essentially the same.

CONCLUSIONS

Biomarker-tailored chemotherapy based on ERCC1, RRM1, and β-tubulin III expression showed significantly increased response rate, median PFS time, and 1-year survival rate in patients with NSCLC.

Cinnamaldehyde/chemotherapeutic agents interaction and drug-metabolizing genes in colorectal cancer

Cinnamaldehyde is an active monomer isolated from the stem bark of Cinnamomum cassia, a traditional oriental medicinal herb, which is known to possess marked antitumor effects in vitro and in vivo. The aim of the present study was to examine the potential advantages of using cinnamaldehyde in combination with chemotherapeutic agents commonly used in colorectal carcinoma (CRC) therapy, as well as to investigate the effect of cinnamaldehyde on chemotherapeutic-associated gene expression. The synergistic interaction of cinnamaldehyde and chemotherapeutic agents on human CRC HT-29 and LoVo cells was evaluated using the combination index (CI) method. The double staining with Annexin V conjugated to fluorescein-isothiocyanate and phosphatidylserine was employed for apoptosis detection. The expression of drug-metabolizing genes, including excision repair cross‑complementing 1 (ERCC1), orotate phosphoribosyltransferase (OPRT), thymidylate synthase (TS), breast cancer susceptibility gene 1 (BRCA1) and topoisomerase 1 (TOPO1), all in HT-29 and LoVo cells, with or without the addition of cinnamaldehyde, was examined by quantitative polymerase chain reaction (PCR). Cinnamaldehyde had a synergistic effect on the chemotherapeutic agents cytotoxicity in HT-29 and LoVo cells. In addition, cinnamaldehyde suppressed BRCA1, TOPO1, ERCC1 and TS mRNA expression, except for OPRT expression, which was markedly upregulated. Our findings indicate that cinnamaldehyde appears to be a promising candidate as an adjuvant in combination therapy with 5-fluorouracil (5-FU) and oxaliplatin (OXA), two chemotherapeutic agents used in CRC treatment. The possible mechanisms of its action may involve the regulation of drug‑metabolizing genes.

High expression levels of class III β-tubulin in resected non-small cell lung cancer patients are predictive of improved patient survival after vinorelbine-based adjuvant chemotherapy

The aim of the present study was to determine the frequency and predictive value of the expression of tumor microtubule components in patients with resected non-small cell lung cancer (R-NSCLC) subsequently treated with vinorelbine-based adjuvant chemotherapy. The expression of the microtubule components was evaluated in 85 R-NSCLC tumor samples using immunohistochemistry. All patients received vinorelbine-based chemotherapy. The predictive value of microtubule protein expression for disease-free survival (DFS) and overall survival (OS) was assessed. The expression of the microtubule components was not associated with any baseline clinicopathological factors in the R-NSCLC patients. High tumor expression levels of class III β-tubulin were correlated with an improved DFS (P=0.033) and a trend towards a longer OS (P=0.226). Class II and IV β-tubulins were not correlated with patient outcome. Multivariate analysis of factors, including gender, age, histology, stage and class II, III and IV β-tubulin expression demonstrated that high levels of class III β-tubulin expression were correlated independently with DFS (P= 0.031). These findings suggest that high class III β-tubulin expression levels in resected tumors are predictive of improved DFS in R-NSCLC patients receiving vinorelbine-based chemotherapy.

The herb medicine formula "chong lou fu fang" increases the cytotoxicity of chemotherapeutic agents and down-regulates the expression of chemotherapeutic agent resistance-related genes in human gastric cancer cells in vitro

The herb medicine formula “Chong Lou Fu Fang” (CLFF) has efficacy in inhibiting the proliferation of human gastric cancer in vitro and in vivo. To explore the potentially useful combination of CLFF with chemotherapeutic agents commonly used in gastric cancer therapy, we assess the interaction between CLFF and these chemotherapeutic agents in both SGC-7901 cell lines and BGC-823 cell lines using a median effect analysis and apoptosis analysis, and we also investigate the influence of CLFF on chemotherapeutic agent-associated gene expression. The synergistic analysis indicated that CLFF had a synergistic effect on the cytotoxicity of 5-fluorouracil (5-FU) in a relative broad dose inhibition range (20–95% fraction affected in SGC-7901cell lines and 5–65% fraction affected in BGC-823 cell lines), while the synergistic interaction between CLFF and oxaliplatin or docetaxel only existed in a low dose inhibition range (≤50% fraction affected in both cell lines). Combination of CLFF and chemotherapeutic agents could also induce apoptosis in a synergistic manner. After 24 h, CLFF alone or CLFF combination with chemotherapeutic agents could significantly suppress the levels of expression of chemotherapeutic agent resistance related genes in gastric cancer cells. Our findings indicate that there are useful synergistic interactions between CLFF and chemotherapeutic agents in gastric cancer cells, and the possible mechanisms might be partially due to the down-regulation of chemotherapeutic agent resistance related genes and the synergistic apoptotic effect.

[Advances of drug resistance marker of gemcitabine for non-small cell lung cancer]

随着药物基因组学、药物遗传学的发展，基因指导下个体化治疗成为提高非小细胞肺癌（non-small cell lung cancer, NSCLC）化疗疗效的有效途径之一。确定药物的相关预测性分子标志物从而指导临床治疗、提高疗效被广泛关注。吉西他滨是目前NSCLC常用化疗药物之一，本文主要阐述了近年来吉西他滨药物耐药相关基因在NSCLC个体化治疗方面的研究进展。

Concomitant chemoradiotherapy using pemetrexed and carboplatin for unresectable stage III non-small cell lung cancer (NSCLC): preliminary results of a phase II study

BACKGROUND

Concomitant chemoradiotherapy is the standard treatment of unresectable stage III non-small cell lung cancer (NSCLC). However, the optimal chemotherapy regimen is still controversial. We have conducted a phase II clinical trial in a Chinese population to evaluate concomitant treatment using pemetrexed/carboplatin chemotherapy and thoracic radiotherapy followed by pemetrexed/carboplatin consolidation chemotherapy in these patients. The purpose of this study is to evaluate the feasibility and activity, and also assess its impact on progression-free survival (PFS).

PATIENTS AND METHODS

A total of 21 patients were enrolled between January 2008 and October 2009. Patients received concomitant pemetrexed 500 mg/m(2), carboplatin area under the curve (AUC) 5 chemotherapy on day 1 repeated every 3 weeks for 2 cycles and thoracic radiotherapy, followed by pemetrexed/carboplatin for 3 cycles as consolidation therapy. Objective response rate according to the RECIST criteria was recorded and toxicity was evaluated using the NCI Common Toxicity Criteria. The Kaplan-Meier method was used to evaluate patient survival. Univariate analysis of patient characteristics and tumor responses was conducted using the Chi-square and Fisher's exact test.

RESULTS

Five (23.8%) and 13 patients (61.9%) had a complete or partial response, respectively, while 2 patient's disease remained stable and 1 patient had progression of the disease. The overall response rate (85.7%, 95% confidence interval (CI): 61-97%) exceeded the goal per study design. The median PFS was 12.0 months (95% CI: 10.6-13.4 months). The statistical analysis of predictive factors of efficacy revealed that the response rate and PFS seemed to a trend favoring adenocarcinoma histology. Main toxicity (grade 3 or greater, %): neutropenia 6 (28.5%); thrombocytopenia 4 (19%); anaemia 5 (23.8%); nausea/vomiting 1 (4.8%); anorexia 1 (4.8%), dysphagia 2 (9.5%), radiation pneumonitis 1 (4.8%) and fatigue 2 (9.5%).

CONCLUSION

This data suggests that concomitant treatment with pemetrexed/carboplatin at full systemic doses and thoracic radiotherapy was well tolerated, with promising activity in a Chinese population with unresectable stage III NSCLC. Better outcomes were observed in patients with adenocarcinoma in this study. Although the data presented herewith appears promising, this study is relatively small, and more data from randomized trials are needed to further validate this regimen.

Effects of Src kinase inhibition induced by dasatinib in non-small cell lung cancer cell lines treated with cisplatin

c-Src is a tyrosine kinase involved in tumor proliferation, migration, and angiogenesis and has been shown to modulate the cytotoxicity following cisplatin-induced DNA damages. c-Src is frequently activated in non-small cell lung cancer (NSCLC) tissues and cell lines, but no preclinical data regarding the effects of the novel potent Src inhibitor, dasatinib (BMS-354825), in the modulation of cisplatin resistance are currently available. The present study reports that treatment with dasatinib completely abrogated Src phosphorylation in the majority of the NSCLC cell lines tested (n = 7), with modest effects on cell proliferation and survival. In five cell lines, a higher cytotoxicity was observed delivering cisplatin in combination with dasatinib: the most evident effects were found in the squamous H520 cells due to the effective block of cisplatin-induced Src phosphorylation. Moreover, dasatinib treatment significantly blocked cisplatin-induced transcription of a panel of DNA repair and synthesis genes. In addition, a real-time PCR analysis done on tumor and matched normal lung specimens from 44 surgically resected NSCLC patients showed that Src transcripts are significantly upregulated in 23% of cases. In conclusion, Src-directed therapeutic strategies could interfere with cisplatin resistance, possibly allowing to reduce cisplatin doses, thus improving its efficacy. The data of this study support further clinical studies aimed to evaluate the efficacy of Src-inhibiting agents in combination with cisplatin in the treatment of NSCLC.

Pemetrexed in first-line treatment of non-small cell lung cancer

Pemetrexed is an antitumor agent traditionally used as monotherapy for the second-line treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) as well as in combination with cisplatin for the treatment of chemonaïve patients with unresectable malignant pleural mesothelioma. Recently, pemetrexed has been approved in combination with cisplatin for the first-line treatment of patients with locally advanced or metastatic NSCLC other than predominantly squamous cell histology. Studies that support the development of this indication are detailed in this review. We performed a PubMed/Medline database search to identify relevant literature from 1998 until August 2008. Bibliographies from identified references were searched, as well as were abstracts from the most relevant congresses in lung cancer area (American Society of Clinical Oncology Congress, World Conferences of Lung Cancer). We detailed pemetrexed studies in the first-line setting of NSCLC treatment, in monotherapy, in combination with platinum and also, with other agents. Data regarding efficacy differences related to different histologic types were also analyzed.

Susceptibility loci involved in cisplatin-induced cytotoxicity and apoptosis

OBJECTIVES

Cisplatin is a widely used chemotherapeutic agent; however, nephrotoxicity and neuropathy are obstacles for drug efficacy. Little is known about the genes or genetic variants contributing to the risk of developing these toxicities or chemotherapeutic response. Thus, we have applied a cell-based model to identify and characterize previously unknown genes that may be involved in cellular susceptibility to cisplatin.

METHODS

Lymphoblastoid cell lines from 27 large Centre d'Etude du Polymorphisme Humain pedigrees were used to elucidate the genetic contribution to cisplatin-induced cytotoxicity. Phenotype was defined as cell growth inhibition following exposure of cell lines to increasing concentrations of cisplatin for 48 h.

RESULTS

Significant heritability, ranging from 0.32 to 0.43 (P<10), was found for the cytotoxic effects of each concentration (1, 2.5, 5, 10, and 20 micromol/l) and IC50, the concentration required for 50% cell growth inhibition. Linkage analysis revealed 11 genomic regions on six chromosomes with logarithm of odds (LOD) scores above 1.5 for cytotoxic phenotypes. The highest LOD score was found on chromosome 4q21.3-q35.2 (LOD=2.65, P=2.4x10(-4)) for 5 micromol/l cisplatin. Quantitative transmission disequilibrium tests were performed using 191973 nonredundant single nucleotide polymorphisms (SNPs) located in the 1 LOD confidence interval of these 11 regions. Twenty SNPs, with 10 SNPs located in five genes, were significantly associated with cisplatin-induced cytotoxicity (P

CONCLUSIONS

Our results suggest that genetic factors involved in cytotoxicity also contribute to cisplatin-induced apoptosis. These cell lines provide a paradigm to identify previously unknown pharmacogenetic variants associated with drug cytotoxicity.

Collapse

Key Words

• apoptosis
• association
• centre d'etude du polymorphisme humain
• cisplatin
• cytotoxicity
• heritability
• linkage

Collapse

MESH Headings

• Antineoplastic Agents/toxicity
• Apoptosis/drug effects
• Apoptosis/genetics
• Cell Line, Transformed
• Cell Proliferation/drug effects
• Cisplatin/toxicity
• Drug Resistance, Neoplasm/genetics
• Genetic Linkage
• Genetic Predisposition to Disease
• Genetic Variation
• Genotype
• Humans
• Lymphocytes/cytology
• Lymphocytes/drug effects
• Pharmacogenetics
• Polymorphism, Single Nucleotide

Collapse

Grants

• R24 GM061374 NIGMS NIH HHS
• U01 GM061393 NIGMS NIH HHS
• GM61374 NIGMS NIH HHS
• GM61393 NIGMS NIH HHS
• U01 GM061374 NIGMS NIH HHS

Collapse

Affiliation(s)

Sunita J. Shukla Department of Human Genetics, University of Chicago, Chicago Illinois, USA
Shiwei Duan Department of Medicine, University of Chicago, Chicago Illinois, USA
Judith A. Badner Department of Psychiatry, University of Chicago, Chicago Illinois, USA
Xiaolin Wu Department of Medicine, University of Chicago, Chicago Illinois, USA
M. Eileen Dolan Department of Medicine, University of Chicago, Chicago Illinois, USA Committee on Cancer Biology University of Chicago, Chicago Illinois, USA Department of Committee on Clinical Pharmacology and Pharmacogenomics, University of Chicago, Chicago Illinois, USA

Collapse

Collaborators Collapse

Class III beta-tubulin expression and benefit from adjuvant cisplatin/vinorelbine chemotherapy in operable non-small cell lung cancer: analysis of NCIC JBR.10

PURPOSE

High class III beta-tubulin (bTubIII) expression in advanced non-small cell lung cancer is known to correlate with reduced response rates and inferior survival with anti-microtubule agents. JBR.10 showed a 12% and 15% improvement in 5-year recurrence-free survival (RFS) and overall survival (OS), respectively, with the addition of cisplatin and vinorelbine following resection of stage IB-II non-small cell lung cancer. We sought to determine the effect of bTubIII on patient outcome and benefit from adjuvant chemotherapy in the JBR.10 trial.

EXPERIMENTAL DESIGN

We did a semiquantitative immunohistochemical assay for bTubIII on primary tumor tissue available from 265 of the 482 patients in JBR.10. Tumors were classified as bTubIII "low" or "high" using a validated method. We examined the prognostic effect of bTubIII in patients treated with or without chemotherapy and the survival benefit from chemotherapy in low versus high bTubIII subgroups.

RESULTS

High bTubIII expression was associated with poorer RFS and OS in patients treated with surgery alone but not in patients treated with adjuvant chemotherapy. The RFS and OS benefits of adjuvant chemotherapy were greater in high versus low tubulin expressors. However, with Cox regression, the interaction between bTubIII status and chemotherapy treatment in predicting RFS or OS did not reach statistical significance.

CONCLUSIONS

Chemotherapy seemed to overcome the negative prognostic effect of high bTubIII expression. Greater benefit from adjuvant chemotherapy was seen in patients with high bTubIII expression. This is contrary to what has been seen in the setting of advanced disease; possible reasons for this difference are being explored.

Gene Expression and Polymorphisms of DNA Repair Enzymes: Cancer Susceptibility and Response to Chemotherapy

Platinum compounds play a central role in cancer chemotherapy. Although treatment is limited by side effects, they continue to have widespread application. One of the main aims of clinical or translational research in cancer is the search for genetic factors that could foresee treatment outcomes, in biologic activity and toxic effects. This genetic analysis might allow selection of patients who will have the greatest benefit from chemotherapy. Furthermore, a better knowledge of the underlying molecular profile of the host and the tumor will facilitate screening for lung cancer susceptibility and tailoring of chemotherapy in individual patients, choosing those most likely to respond, adjusting doses more precisely in order to reduce less adverse effects, and establishing safety profiles based on individual genetic analyses. Herein, we discuss current knowledge regarding gene expression and polymorphisms of DNA repair enzymes in regard to cancer susceptibility and response to chemotherapy.

Synergistic interaction between tetrandrine and chemotherapeutic agents and influence of tetrandrine on chemotherapeutic agent-associated genes in human gastric cancer cell lines

PURPOSE

Tetrandrine (Tet), a bis-benzylisoquinoline alkaloid that was isolated from the dried root of Hang-Fang-Chi (Stephania tetrandra S. Moore), is well known as processing a marked antitumor effect in vitro and in vivo. The aim of this study was to assess the interaction between tetrandrine and chemotherapeutic agents widely used in gastric cancer treatment, and to investigate the influence of tetrandrine on chemotherapeutic agent-associated gene expression and apoptosis.

METHODS

Synergistic interaction on human gastric cancer BGC-823 and MKN-28 cells was evaluated using the combination index (CI) method. The double staining with both Annexin-V-FITC and PI was employed to distinguish the apoptotic cells from living cells. Expression of chemotherapeutic agent-associated genes, i.e., excision repair cross-complementing 1 (ERCC1), thymidylate synthase (TS), class III beta-tubulin (beta-tubulin III) and tau, of BGC-823 cells with or without tetrandrine treatment were measured by real-time quantitative PCR.

RESULTS

Tetrandrine had a synergistic effect on the cytotoxicity of chemotherapeutic agents in both two gastric cancer cell lines. The combination of tetrandrine and chemotherapeutic agents could also induce apoptosis in a synergistic manner. Tetrandrine could suppress the mRNA expression of ERCC1, TS, beta-tubulin III and tau. Most prominently, ERCC1, TS and beta-tubulin III mRNA levels were markedly suppressed at 0.29-, 0.12- and 0.60-fold, respectively, by the presentation of tetrandrine.

CONCLUSION

Tetrandrine appears a promising candidate for combining with three chemotherapeutic agents. The possible mechanisms might be the synergistic apoptotic effect and the downregulation of chemotherapeutic agent-associated genes.

Identification of MMS19 domains with distinct functions in NER and transcription

Nucleotide excision repair (NER) and RNA polymerase II (Pol II) transcription are essential cellular processes which are intimately intertwined. They share an indispensable multiprotein complex, TFIIH, and impairments in either process can impact the efficiency of the other. Like TFIIH, MMS19 is required for NER and Pol II transcription, but its precise role in each process is unknown. We showed previously that the human MMS19 gene originates multiple splice variants, some of which may encode distinct MMS19 protein isoforms. Here we characterize a novel MMS19 transcript and demonstrate for the first time that MMS19 splice variants are conserved across species and are functionally distinct. Expression of human MMS19 splice variants in mms19-deleted yeast cells produced unique patterns of thermosensitivity and ultraviolet radiation-sensitivity that point to three MMS19 structural domains with distinct in vivo functions. MMS19 polypeptides lacking domain A are able to fulfill the role of full-length MMS19 in NER but not in transcription. MMS19 polypeptides lacking part of domain B are efficient in transcription but not in NER. MMS19 polypeptides lacking domain C (HEAT repeats) are unable to fulfill either function. Our data suggest that the MMS19 HEAT repeat domain is essential for MMS19 function in NER and transcription, while domains A and B, within MMS19 N-terminus, modulate the balance between DNA repair and transcription. Our results highlight the functional significance of MMS19 transcripts and the possible contribution of MMS19 isoforms to regulate the switch between NER and transcription. Furthermore, our work associates for the first time specific protein domains with MMS19's role in NER and transcription.

Proteasome inhibitors in lung cancer

Proteasome inhibition is a novel therapeutic approach that is being investigated in non-small cell and small cell lung cancer (NSCLC and SCLC). Proteasome inhibition affects a range of intracellular signals and disrupts the levels of numerous proteins, causing apoptosis via multiple pathways. Importantly, malignant cells are more sensitive to proteasome inhibition than normal cells. A number of proteasome inhibitors have demonstrated activity in preclinical studies, both as single agents and in combination with conventional and novel antineoplastic agents. However, only bortezomib, a dipeptide boronic acid analog, has been investigated in lung cancer clinical trials, in which it has shown activity as a single agent and in combination regimens. Numerous preclinical and clinical studies are ongoing in both NSCLC and SCLC. Proteasome inhibition could potentially play a significant role in the future management of these conditions.

Second-Line Treatment Options in Non–Small Cell Lung Cancer: A Comparison of Cytotoxic Agents and Targeted Therapies

Current options for the second-line treatment of non-small cell lung cancer (NSCLC) include cytotoxic drugs, such as docetaxel and pemetrexed, and targeted therapies. Docetaxel was approved in the United States and Europe in 2000 after two phase III trials showed drug superiority versus best supportive care alone and versus alternative single-agent chemotherapy. Pemetrexed was approved in the United States and Europe in 2004 after a phase III trial showed that, compared with docetaxel, it had comparable activity (median survival time of approximately 8 months in both arms) and a more favorable toxicity profile: grade 3-4 neutropenia was observed in 5.3% versus 40.2% of patients in the pemetrexed and docetaxel arms, respectively, while febrile neutropenia was observed in 1.9% versus 12.7% of patients, respectively. In the United States, gefitinib and erlotinib have also been approved for the treatment of recurrent NSCLC (in 2003 and 2004, respectively), while in Europe the registration of these agents is currently under evaluation. This review focuses on the use of docetaxel and pemetrexed for the second-line treatment of NSCLC and compares these drugs with targeted therapies, highlighting the latest developments in pharmacogenomics that might lead to a more tailored approach to treatment.

Pharmacogenetics and pharmacogenomics in oncology therapeutic antibody development

Pharmacogenetics and pharmacogenomics are keys to the success of personalized medicine, prescribing drugs based on a patien's individual genetic and biological profile. In this review, we will focus on the application of pharmacogenetics and pharmacogenomics in developing monoclonal antibody (MAb) therapeutics in oncology. The significance of pharmacogenomics in MAb therapeutics is highlighted by the association between polymorphisms in Fc receptors and clinical response to anti-CD20 MAb rituximab (Rituxan®) or anti-ganglioside GD2 MAb 3F8, as well as the potential link between polymorphisms in HER2 and cardiac toxicity in patients treated with the anti-HER2 MAb trastuzumab (Herceptin®). The dependence on gene copy number or expression levels ofHER2 and epidermal growth factor receptor (EGFR) for therapeutic efficacy of trastuzumab and cetuximab (Erbitux®), respectively, supports the importance of selecting suitable patient populations based on their pharmacogenetic profile. In addition, a better understanding of target mutation status and biological consequences will benefit MAb development and may guide clinical development and use of these innovative therapeutics. The application of pharmacogenetics and pharmacogenomics in developing MAb therapeutics will be largely dependent on the discovery of novel surrogate biomarkers and identification of disease- and therapeutics-relevant polymorphisms. Challenges and opportunities in biomarker discovery and validation, and in implementing clinical pharmacogenetics and pharmacogenomics in oncology MAb development and clinical practice will also be discussed.

Antiapoptotic signaling pathways in non-small-cell lung cancer: biology and therapeutic strategies

One of the hallmarks of lung cancer is the deregulation of apoptotic or programmed cell death mechanisms usually found in normal cells that allow for corrupted cells to undergo cellular suicide. This includes mechanisms that attenuate proapoptotic pathways and/or amplify antiapoptotic pathways. Increasing evidence suggests that lung cancer cells use multiple and perhaps redundant pathways to maintain survival. Increasing knowledge of these pathways offers a better understanding of the biology of lung cancer as well as novel therapeutic strategies that can enhance lung cancer cell death. This review discusses the apoptotic machinery and signal transduction pathways that regulate apoptosis, methods of identifying the presence of activated survival signaling pathways in human lung cancers, and the clinical significance and relevance for therapy for patients with lung cancer.

Gene expression as a predictive marker of outcome in stage IIB-IIIA-IIIB non-small cell lung cancer after induction gemcitabine-based chemotherapy followed by resectional surgery

PURPOSE

The first suggestions of a relationship between gene mRNA expression and differential sensitivity to gemcitabine/cisplatin are now emerging. ERCC1, RRM1, and XPD are involved in the nucleotide excision repair pathways, and tumor up-regulation of these genes leads to chemotherapy failure. In the present study, we have examined the potential correlation and predictive value of ERCC1, RRM1, and XPD mRNA expression in resected specimens from 67 stage IIB, IIIA, and IIIB non-small cell lung cancer patients treated with neoadjuvant gemcitabine/platinum followed by surgery.

EXPERIMENTAL DESIGN

ERCC1, RRM1, and XPD expression was quantified using real-time quantitative reverse transcription-PCR.

RESULTS

A good correlation was found between mRNA expression levels of the three genes. For RRM1 levels, patients in the bottom quartile had a decreased risk of death compared with those in the top quartile (risk ratio = 0.30; P = 0.033). Median survival for the 17 patients in the bottom quartile was 52 months, whereas for the 15 in the top quartile, it was 26 months (P = 0.018). When the characteristics of these 17 patients were compared with all of the other 50 patients, no differences in initial staging were observed. However, the 17 patients in the bottom quartile had better outcomes, including more radiographic responses (65% versus 54%; P = 0.24), complete resections (94% versus 72%; P = 0.03), lobectomies (71% versus 34%; P = 0.004), and pathological complete responses (29% versus 0%; P = 0.00001).

CONCLUSIONS

Patients with RRM1 levels in the bottom quartile benefited significantly from gemcitabine/cisplatin neoadjuvant chemotherapy, leading us to conclude that RRM1 mRNA levels should be additionally validated to proceed with tailored chemotherapy.

The biology of non-small-cell lung cancer: identifying new targets for rational therapy

Lung cancer, and in particular non-small-cell lung cancer (NSCLC), remains the leading cause of cancer death throughout the world. Almost three decades ago, the major concern was to identify whether cisplatin or cisplatin-based chemotherapy enhanced survival in metastatic NSCLC, and whether any survival benefit compensated for cisplatin-related toxicity. Over the last 10 years, significant advances have been achieved in molecular biology, including the identification of critical genes related to the pathogenesis of NSCLC, which have formed the basis for new targeted therapeutic approaches. These new approaches include novel agents against established chemotherapeutic targets such as thymidylate synthetase as well as agents that inhibit novel targets such as growth factor receptors and proteins important in angiogenesis. With the advent of genomic technologies that can identify patterns of gene expression, the hope is that therapy will be tailored to the genetic pattern of the patients's tumor, and individualized treatments that minimize toxicity and maximize efficacy can be developed.

Gene Expression Profiling in Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the most common cause of premature death from malignant disease in western countries. A better understanding of the molecular mechanisms underlying NSCLC etiology, pathogenesis, and therapeutics will lead to improved clinical outcomes. Recent technological advances in gene expression profiling (in particular, with cDNA and oligonucleotide microarrays) allow the simultaneous analysis of the expression of thousands of genes. In this review, the technology of global gene expression profiling is discussed, and the progress made thus far with it in NSCLC is reviewed. A new molecular classification of NSCLC has been developed, which has provided important insights into etiology and pathogenesis. Other studies have found potential biomarkers for NSCLC that may be of use in diagnosis, screening, and assessing the effectiveness of therapy. Finally, advances have been made in the understanding of the molecular mechanisms of NSCLC progression and the molecular mechanisms of action of currently used cytotoxic drugs. This may facilitate the improvement of current therapeutics and the identification of novel targets. Taken together, these advances hold the promise of an improved understanding of the molecular biology of NSCLC and its treatment, which in turn will lead to improved outcomes for this deadly disease.

Pharmacogenomic strategies for developing customized chemotherapy in non-small cell lung cancer

In this review, we deal with six groups of cytotoxic drugs commonly used in the treatment of non-small cell lung cancer (NSCLC). Although there are many reviews of thymidylate synthase (TS) and antifolate inhibitors, in this article, we have tried to highlight aspects that are more important for medical oncologists to consider when treating NSCLC patients. There is compelling evidence that TS gene transcripts and TS polymorphisms could be used to decide which patients can best benefit from adjuvant chemotherapy approaches, especially in colorectal cancer, and not less importantly, to tailor chemotherapy in metastatic NSCLC when using drugs akin to fluorouracil, such as pemetrexed. Secondly, cisplatin is central to chemotherapy combinations and evidence indicates that DNA repair capacity influences response to cisplatin-based regimens. ERCC1 gene transcript stands out as a predictive marker of cisplatin sensitivity. Thirdly, preliminary studies indicate that upregulation of beta-tubulin III correlates with response to paclitaxel and vinorelbine. Fourthly, overexpression of ribonucleotide reductase can influence response to gemcitabine. Fifthly, we describe mechanisms of resistance to topoisomerase I inhibitors, although this subject has not yet been completely elucidated. Finally, to understand the mechanisms of resistance to EGF-R inhibitors, which have been shown to be useful in many different types of cancer, the Src-STAT signaling pathways are described here in detail. Hopefully, the assessment of Src and of STAT-3 can be implemented as predictive markers.

Molecular markers and targeted therapy with novel agents: prospects in the treatment of non-small cell lung cancer

Detection of genomic differences predictive of drug response or resistance in individual patients may allow therapy to be customized to the characteristics of particular tumors. Preliminary findings are that non-small cell lung cancer patients overexpressing ERCC1 mRNA have lower response to cisplatin chemotherapy, while those overexpressing ribonucleotide reductase mRNA have limited benefit from gemcitabine. In addition, overexpression of beta-tubulin III and stathmin can influence the sensitivity to microtubule interacting drugs, like vinorelbine and paclitaxel. The introduction of biological agents which target highly specific intracellular pathways offers the promise of enhancing the efficacy of cytotoxic chemotherapy. Among many promising biological agents is the monoclonal antibody C225, which blocks the EGFR receptor. The addition of C225 appears to induce responses in a proportion of colon cancer patients refractory to 5-FU or irinotecan, supporting pre-clinical evidence of synergistic activity. It also appears from xenograft data that C225 enhances the sensitivity of tumors to radiation and docetaxel or the combination.