To identify the genetic factors that influence overall survival in never smokers who have non-small cell lung cancer (NSCLC), we performed a consistency meta-analysis study utilizing genome-wide association approaches for overall survival in 327 never smoker NSCLC patients from the MD Anderson Cancer Center and 293 cases from the Mayo Clinic. We then performed a two-pronged validation of the top 25 variants that included additional validation in 1,256 NSCLC patients from Taiwan and assessment of expression quantitative trait loci (eQTL) and differential expression of genes surrounding the top loci in 70 tumors and matched normal tissues. A total of 94 loci were significant for overall survival in both MD Anderson and Mayo studies in the consistency meta-analysis phase, with the top 25 variants reaching a p-value of 10−6. Two variants of these 25 were also significant in the Taiwanese population: rs6901416 (HR:1.44, 95%CI:1.01-2.06) and rs10766739 (HR:1.23, 95%CI:1.00-1.51). These loci resulted in a reduction in median survival time of at least 8 and 5 months in three populations, respectively. An additional six variants (rs4237904, rs7976914, rs4970833, rs954785, rs485411, and rs10906104) were validated through eQTL analysis that identified significant correlations with expression levels of six genes (LEMD3, TMBIM, ATXN7L2, SHE, ITIH2, and NUDT5, respectively) in normal lung tissue. These genes were also significantly differentially expressed between the tumor and normal lung. These findings identify several novel, candidate prognostic markers for NSCLC in never smokers, with eQTL analysis suggesting a potential biological mechanism for a subset of these observed associations.
After neoadjuvant chemoradiation (CXRT) for esophageal cancer, surgery has traditionally been recommended to be performed within 8 weeks. However, surgery is often delayed for various reasons. Data from other cancers suggests that delaying surgery may increase the pathologic complete response rate. However, there are theoretical concerns that waiting longer after radiation may lead to a more difficult operation and more complications. The optimal timing of esophagectomy after CXRT is unknown.
From a prospective database, we analyzed 266 patients with resected esophageal cancer who were treated with neoadjuvant CXRT from 2002–2008. Salvage resections were excluded from this analysis. We compared patients who had surgery within 8 weeks of CXRT and those who had surgery after 8 weeks. We used multivariable analysis to determine whether increased interval between chemoradiation and surgery was independently associated with perioperative complication, pathologic response, or overall survival.
150 patients were resected within 8 weeks and 116 were resected greater than 8 weeks after completing CXRT. Mean length of operation, intraoperative blood loss, anastomotic leak rate, and perioperative complication rate were similar for the two groups. Pathologic complete response rate and overall survival were also similar for the two groups (p=NS). In multivariable analysis, timing of surgery was not an independent predictor of perioperative complication, pathologic complete response, or overall survival.
The timing of esophagectomy after neoadjuvant CXRT is not associated with perioperative complication, pathologic response, or overall survival. It may be reasonable to delay esophagectomy beyond 8 weeks for patients who have not yet recovered from chemoradiation.
Adjuvant/neoadjuvant therapy; Esophageal Cancer; Radiation Therapy; Esophageal Surgery
Given the density of single nucleotide polymorphisms (SNPs) in the human genome and the sensitivity of single nucleotide changes in microRNA (miRNA) functionality and processing, we asked whether polymorphisms within miRNA processing pathways and binding sites may influence non-small cell lung cancer (NSCLC) patients’ prognosis. We genotyped 240 miRNA-related SNPs in 535 stage I and II NSCLC patients to determine associations with overall recurrence and survival, as well as effect in specific treatment subgroups. After correcting for multiple comparisons, the G allele of FZD4:rs713065 displayed a significant association with decreased risk of death in surgery-only patients (HR:0.46, 95%CI:0.32-0.65). DROSHA:rs6886834 variant A allele (HR:6.38, 95%CI:2.49-16.31) remained significant for increased risk of recurrence in the overall and surgery-only populations, respectively. FAS:rs2234978 G allele remained significantly associated with survival in all patients (HR:0.59, 95%CI:0.44-0.77), while borderline significant in subgroups (surgery only: HR:0.59, 95%CI:0.42-0.84; surgery plus chemo: HR:0.19, 95%CI:0.07-0.46). Luciferase assays demonstrated that the FAS SNP created a miR-651 functional binding site. Survival tree analysis was performed to classify patients into distinct risk subgroups based on their risk genotype combinations. These results indicate that miRNA-related polymorphisms may be associated with NSCLC patients’ clinical outcomes through altered miRNA regulation of target genes.
NSCLC; recurrence; overall survival; early stage; miRNA; binding site; single nucleotide polymorphism
RNA-dependent protein kinase (PKR) is an independent prognostic variable in patients with non-small cell lung cancer (NSCLC). In the present study, we investigated the correlation between PKR and 25 other biomarkers for NSCLC, identified the markers that could further improve the prognostic significance of PKR, and elucidated the mechanisms of interaction between these markers and PKR.
Tissue microarray samples obtained from 218 lung cancer patients were stained with an anti-PKR antibody and antibodies against 25 biomarkers. Immunohistochemical expression was scored and used for Kaplan-Meier survival analysis. The interaction between PKR and EphA2 in NSCLC cell lines was examined.
We found that PKR was associated with EphA2 and that the prognostic information regarding NSCLC provided by the combination of PKR and EphA2 (P/E) was significantly more accurate than that provided by either marker alone. The 5-year overall survival rate in PKRlow/EphA2high patients (20%) was significantly lower than that of PKRhigh/EphA2low patients (74%), PKRhigh/EphA2high patients (55%), and PKRlow/EphA2low patients (55%) (p< 0.0001). We also found that the PKR:EphA2 (P/E) ratio was significantly associated with prognosis (p< 0.0001). Univariate and multivariate Cox analyses revealed that this P/E combination or ratio was an independent predictor of overall survival. In addition, induction of PKR expression reduced EphA2 protein expression levels in NSCLC cell lines.
PKR/EphA2 is a significant predictor of prognosis for NSCLC. PKR/EphA2 may be a promising approach to improving screening efficiency and predicting prognosis in NSCLC patients.
PKR; EphA2; Biomarker; Lung cancer
Phenotypic biomarkers of DNA damage repair may enhance cancer risk prediction. The γ-H2AX formed at the sites of double strands break (DSB) after ionizing radiation (IR) is a specific marker of DNA damage.
In an ongoing case-control study, the baseline and IR-induced γ-H2AX levels in peripheral blood lymphocytes (PBLs) from frequency-matched 306 untreated lung cancer patients and 306 controls were measured by a laser scanning cytometer-based immunocytochemical method. The ratio of IR-induced γ-H2AX level to the baseline was used to evaluate inter-individual variation of DSB damage response and to assess the risk of lung cancer by using unconditional multivariable logistic regression with adjustment of age, sex, ethnicity, smoking status, family history of lung cancer, dust exposure and emphysema.
The mean γ-H2AX ratio was significantly higher in cases than controls (1.46±0.14 vs. 1.41±0.12, P < 0.001). Dichotomized at the median in controls, high γ-H2AX ratio was significantly associated with increased risk of lung cancer (OR = 2.43, 95% CI: 1.66–3.56). There was also a significant dose-response relationship between γ-H2AX ratio and lung cancer risk in quartile analysis. Analysis of joint effects with other epidemiological risk factors revealed elevated risk with increasing number of risk factors.
γ-H2AX activity as shown by measuring DSB damage in IR-irradiated PBLs may be a novel phenotypic marker of lung cancer risk.
γ-H2AX assay is a robust and quantifiable image-based cytometer method that measures mutagen-induced DSB response in PBLs as a potential biomarker in lung cancer risk assessment.
Double strands break; γ-H2AX; mutagen sensitivity; lung cancer risk
The approach of RNA interference (RNAi)- using antisense DNA or RNA oligonucleotides to silence activity of a specific pathogenic gene transcript and reduce expression of the encoded protein- is very useful in dissecting genetic function and holds significant promise as a molecular therapeutic. A major obstacle in achieving gene silencing with RNAi technology is the systemic delivery of therapeutic oligonucleotides. Here we demonstrate an engineered gold nanoshell (NS)-based therapeutic oligonucleotide delivery vehicle, designed to release its cargo on demand upon illumination with a near-infrared (NIR) laser. A poly(L)lysine peptide (PLL) epilayer covalently attached to the NS surface (NS-PLL) is used to capture intact, single-stranded antisense DNA oligonucleotides, or alternatively, double-stranded short-interfering RNA (siRNA) molecules. Controlled release of the captured therapeutic oligonucleotides in each case is accomplished by continuous wave NIR laser irradiation at 800 nm, near the resonance wavelength of the nanoshell. Fluorescently tagged oligonucleotides were used to monitor the time-dependent release process and light-triggered endosomal release. A green fluorescent protein (GFP)-expressing human lung cancer H1299 cell line was used to determine cellular uptake and gene silencing mediated by the NS-PLL carrying GFP gene-specific single-stranded DNA antisense oligonucleotide (AON-GFP), or a double-stranded siRNA (siRNA-GFP), in vitro. Light-triggered delivery resulted in ∼ 47% and ∼49% downregulation of the targeted GFP expression by AON-GFP and siRNA-GFP, respectively. Cytotoxicity induced by both the NS-PLL delivery vector and by laser irradiation is minimal, as demonstrated by a XTT cell proliferation assay.
Plasmon; nanoshell; antisense oligonucleotide; siRNA; Gene therapy; controlled drug release; polylysine
TUSC2-defective gene expression is detected in the majority of lung cancers and is associated with worse overall survival. We analyzed the effects of TUSC2 re-expression on tumor cell sensitivity to the AKT inhibitor, MK2206, and explored their mutual signaling connections, in vitro and in vivo. TUSC2 transient expression in three LKB1-defective non-small cell lung cancer (NSCLC) cell lines combined with MK2206 treatment resulted in increased repression of cell viability and colony formation, and increased apoptotic activity. In contrast, TUSC2 did not affect the response to MK2206 treatment for two LKB1-wild type NSCLC cell lines. In vivo, TUSC2 systemic delivery, by nanoparticle gene transfer, combined with MK2206 treatment markedly inhibited growth of tumors in a human LKB1-defective H322 lung cancer xenograft mouse model. Biochemical analysis showed that TUSC2 transient expression in LKB1-defective NSCLC cells significantly stimulated AMP-activated protein kinase (AMPK) phosphorylation and enzymatic activity. More importantly, AMPK gene knockdown abrogated TUSC2-MK2206 cooperation, as evidenced by reduced sensitivity to the combined treatment. Together, TUSC2 re-expression and MK2206 treatment was more effective in inhibiting the phosphorylation and kinase activities of AKT and mTOR proteins than either single agent alone. In conclusion, these findings support the hypothesis that TUSC2 expression status is a biological variable that potentiates MK2206 sensitivity in LKB1-defective NSCLC cells, and identifies the AMPK/AKT/mTOR signaling axis as an important regulator of this activity.
We recently showed that IGFBP2 is overexpressed in primary lung cancer tissues. This study aims to determine whether IGFBP2 is elevated in blood samples of lung cancer patients and whether its level is associated with clinical outcomes.
Plasma IGFBP2 levels were determined blindly by enzyme-linked immunosorbent assay in 80 lung cancer patients and 80 case-matched healthy controls for comparison. We analyzed blood samples for IGFBP2 levels from an additional 84 patients with lung cancer and then tested for associations between blood IGFBP2 levels and clinical parameters in all 164 lung cancer patients. All statistical tests were two-sided and differences with p<0.05 were considered significant. The mean plasma concentration of IGFBP2 in lung cancer patients was significantly higher than that in healthy controls (388.12±261.00 ng/ml vs 219.30±172.84 ng/ml, p<0.001). IGFBP2 was increased in all types of lung cancer, including adenocarcinoma, squamous cell cancer, and small-cell cancer, regardless of patients’ age, sex, or smoking status. IGFBP2 levels were mildly but significantly associated with tumor size and were significantly higher in stage IV than stage I or III disease. A multivariate analysis showed that lung cancer patients whose blood IGFBP2 was higher than 160.9 ng/ml had a poor survival outcome, with a hazard ratio of 8.76 (95% CI 1.12-68.34, p=0.038 after adjustment for tumor size, pathology, and stage). The median survival time for patients with blood IGFBP2 >160.9 ng/ml is 15.1 months; whereas median survival time was 128.2 months for the patients whose blood IGFBP2 was ≤160.9 ng/ml (p =0.0002).
Blood IGFBP2 is significantly increased in lung cancer patients. A high circulating level of IGFBP2 is significantly associated with poor survival, suggesting that blood IGFBP2 levels could be a prognostic biomarker for lung cancer.
With the proliferation of high-throughput technologies, genome-level data analysis has become common in molecular biology. Bioinformaticians are developing extensive resources to annotate and mine biological features from high-throughput data. The underlying database management systems for most bioinformatics software are based on a relational model. Modern non-relational databases offer an alternative that has flexibility, scalability, and a non-rigid design schema. Moreover, with an accelerated development pace, non-relational databases like CouchDB can be ideal tools to construct bioinformatics utilities. We describe CouchDB by presenting three new bioinformatics resources: (a) geneSmash, which collates data from bioinformatics resources and provides automated gene-centric annotations, (b) drugBase, a database of drug-target interactions with a web interface powered by geneSmash, and (c) HapMap-CN, which provides a web interface to query copy number variations from three SNP-chip HapMap datasets. In addition to the web sites, all three systems can be accessed programmatically via web services.
NoSQL database; copy number variation; drug-target interaction; data integration
NSC-743380 is a novel STAT3 inhibitor that suppresses the growth of several NCI-60 cancer cell lines derived from different tissues and induces regression of xenograft tumors in vivo at various doses. To evaluate the antitumor activity of NSC-743380 in lung cancer cells, we analyzed the susceptibility of 50 NSCLC cell lines to this compound using cell viability assay. About 32% (16 of 50) of these cell lines were highly susceptible to this compound, with a 50% inhibitory concentration (IC50) of <1 µM. In mechanistic studies, the increased numbers of apoptotic cells as well as increased PARP cleavage showed that cytotoxic effects correlate with apoptosis induction. Treatment with NSC-743380 inhibited transcription factor STAT3 activation and induced ROS production in sensitive human lung cancer cell lines but not in resistant cells. Blocking ROS generation with the antioxidant NDGA dramatically abolished NSC-743380-induced growth suppression and apoptosis, but had minimal effect on NSC-743380-induced STAT3 inhibition, suggesting that STAT3 inhibition is not caused by ROS production. Interestingly, knockdown of STAT3 with use of shSTAT3 induced ROS generation and suppressed tumor cell growth. Moreover, scavenging ROS induced by STAT3 inhibition also diminished antitumor activity of STAT3 inhibition. In vivo administration of NSC-743380 suppressed tumor growth and p-STAT3 in lung tumors. Our results indicate that NSC-743380 is a potent anticancer agent for lung cancer and that its apoptotic effects in lung cancer cells are mediated by induction of ROS through STAT3 inhibition.
Drug development; Lung Cancer; STAT3; Reactive oxygen species
Early-stage non–small cell lung cancer (NSCLC) is potentially curable, however, many patients develop recurrent disease. Therefore, identification of biomarkers that can be used to predict patient’s risk of recurrence and survival is critical. Genetic polymorphisms or single-nucleotide polymorphisms (SNP) of DNA- and histone-modifying genes, particularly those of O6-methylguanine DNA-methyltransferase (MGMT), have been linked to an increased risk of lung cancer as well as treatment outcomes in other tumors.
We assessed the association of 165 SNPs in selected epigenetic enzyme genes, DNA methyltransferases, and methyl-CpG–binding proteins with cancer recurrence in 467 patients with stage I or II NSCLC treated with either surgery alone (N = 340) or surgery plus (neo)-adjuvant chemotherapy (N = 127).
We found several SNPs to be strongly correlated with tumor recurrence. We identified 10 SNPs that correlated with the outcome in patients treated with surgery alone but not in patients treated with surgery and adjuvant chemotherapy, which suggested that the addition of platinum-based chemotherapy could reverse the high genetic risk of recurrence. We also identified 10 SNPs that predicted the risk of recurrence in patients treated with surgery plus adjuvant chemotherapy but not in patients treated with surgery alone. The cumulative effect of these SNPs significantly predicted outcomes with P-values of 10−9and 10−6, respectively.
The first set of genotypes may be used as novel predictive biomarkers to identify patients with stage I NSCLC, who could benefit from adjuvant chemotherapy, and the second set of SNPs might predict response to adjuvant chemotherapy.
The optimal treatment for locally advanced superior sulcus tumors is not clear. The authors report long-term results of a trial examining the safety and efficacy of surgery followed by concurrent chemoradiation therapy for this disease.
Thirty-two patients with resectable or marginally resectable superior sulcus tumors at The University of Texas MD Anderson Cancer Center from 1994 to 2010 were enrolled in a prospective trial. Surgery involved segmentectomy or lobectomy with en bloc resection of the involved chest wall and complete nodal staging; radiation therapy (RT) began 14 to 42 days later to a dose of 60 grays (Gy) in 50 1.2-Gy fractions if surgical margins were negative or 64.8 Gy in 54 1.2-Gy fractions if margins were positive. Two cycles of etoposide (50 mg/ m2) and cisplatin (50 mg/m2) were given during RT, and another 3 cycles were given after RT. Eleven patients underwent prophylactic cranial irradiation (PCI).
The protocol completion rate was 78%. Gross total resection was accomplished in all 32 patients; 28% underwent R1 resection. Operative mortality was 0%. The most common surgical complication was postoperative pneumonia (25%). At a median follow-up time of 53.4 months (range, 2–154 months), the 2-year, 5-year, and 10-year rates of locoregional control were 84%, 76%, and 76%; distant metastasis-free survival, 52%, 48%, and 48%; disease-free survival, 49%, 45%, and 45%; and overall survival, 72%, 50%, and 45%, respectively. The brain was the most common site of distant failure (n =5), but no patient who received PCI experienced brain metastasis.
Surgery followed by postoperative chemoradiation is safe and effective for the treatment of marginally resectable superior sulcus tumors.
Pancoast tumor; lung neoplasms; adjuvant radiotherapy; adjuvant chemotherapy; chemoradiation
Pathologic downstaging following chemotherapy for stage III-N2 NSCLC is a well-known positive prognostic indicator. However, the predictive factors for locoregional recurrence (LRR) in these patients are largely unknown.
Between 1998 and 2008, 153 patients with clinically or pathologically staged III-N2 NSCLC from two cancer centers in the United States were treated with induction chemotherapy and surgery. All had pathologic N0-1 disease, and none received postoperative radiotherapy. LRR were defined as recurrence at the surgical site, lymph nodes (levels 1–14 including supraclavicular), or both.
Median follow-up was 39.3 months. Pretreatment N2 status was confirmed pathologically (18.2 %) or by PET/CT (81.8 %). Overall, the 5-year LRR rate was 30.8 % (n = 38), with LRR being the first site of failure in 51 % (22/+99877943). Five-year overall survival for patients with LRR compared with those without was 21 versus 60.1 % (p < 0.001). Using multivariate analysis, significant predictors for LRR were pN1 disease at time of surgery (p < 0.001, HR 3.43, 95 % CI 1.80–6.56) and a trend for squamous histology (p = 0.072, HR 1.93, 95 % CI 0.94–3.98). Five-year LRR rate for pN1 versus pN0 disease was 62 versus 20 %. Neither single versus multistation N2 disease (p = 0.291) nor initial staging technique (p = 0.306) were predictors for LRR. N1 status also was predictive for higher distant recurrence (p = 0.021, HR 1.91, 95 % CI 1.1–3.3) but only trended for poorer survival (p = 0.123, HR 1.48, 95 % CI 0.9–2.44).
LRR remains high in resected stage III-N2 NSCLC patients after induction chemotherapy and nodal downstaging, particularly in patients with persistent N1 disease.
Electronic supplementary material
The online version of this article (doi:10.1245/s10434-012-2800-x) contains supplementary material, which is available to authorized users.
The CACNA2D2 gene, a new subunit of the Ca2+-channel complex, was identified in the homozygous deletion region of chromosome 3p21.3 in human lung and breast cancers. Expression deficiency of the CACNA2D2 in cancer cells suggests a possible link of it to Ca2+ signaling in the pathogenesis of lung cancer and other cancers. We investigated the effects of overexpression of CACNA2D2 on intracellular Ca2+ contents, mitochondria homeostasis, cell proliferation, and apoptosis by adenoviral vector-mediated wild-type CACNA2D2 gene transfer in 3p21.3-deficient nonsmall cell lung cancer cell lines. Exogenous expression of CACNA2D2 significantly inhibited tumor cell growth compared with the controls. Overexpression of CACNA2D2 induced apoptosis in H1299 (12.5%), H358 (13.7%), H460 (22.3%), and A549 (50.1%) cell lines. Levels of intracellular free Ca2+ were elevated in AdCACNA2D2-transduced cells compared with the controls. Mitochondria membrane depolarization was observed prior to apoptosis in Ad-CACNA2D2 and Adp53-transduced H460 and A549 cells. Release of cyt c into the cytosol, caspase 3 activation, and PARP cleavage were also detected in these cells. Together, these results suggest that one of the pathways in CACNA2D2-induced apoptosis is mediated through disruption of mitochondria membrane integrity, the release of cyt c, and the activation of caspases, a process that is associated with regulation of cytosolic free Ca2+ contents.
tumor suppressor genes; apoptosis; calcium channel proteins; human chromosome 3p21.3; lung cancer
A group of candidate tumor suppressor genes (designated CACNA2D2, PL6, 101F6, NPRL2, BLU, RASSF1, FUS1, HYAL2, and HYAL1) has been identified in a 120-kb critical tumor homozygous deletion region (found in lung and breast cancers) of human chromosome 3p21.3. We studied the effects of six of these 3p21.3 genes (101F6, NPRL2, BLU, FUS1, HYAL2, and HYAL1) on tumor cell proliferation and apoptosis in human lung cancer cells by recombinant adenovirus-mediated gene transfer in vitro and in vivo. We found that forced expression of wild-type FUS1, 101F6, and NPRL2 genes significantly inhibited tumor cell growth by induction of apoptosis and alteration of cell cycle processes in 3p21.3 120-kb region-deficient (homozygous) H1299 and A549 cells but not in the 3p21.3 120-kb region-heterozygous H358 and the normal human bronchial epithelial cells. Intratumoral injection of Ad-101F6, Ad-FUS1, Ad-NPRL2, and Ad-HYAL2 vectors or systemic administration of protamine-complexed vectors significantly suppressed growth of H1299 and A549 tumor xenografts and inhibited A549 experimental lung metastases in nu/nu mice. Together, our results, coupled with other studies demonstrating a tumor suppressor role for the RASSSF1A isoform, suggest that multiple contiguous genes in the 3p21.3 120-kb chromosomal region may exhibit tumor suppressor activity in vitro and in vivo.
Persistent pathologic mediastinal nodal involvement after induction chemotherapy and surgical resection is a negative prognostic factor for stage III-N2 non-small cell lung cancer patients. This population has high rates of local-regional failure and distant failure, yet the effectiveness of additional therapies is not clear. We assessed the role of consolidative therapies (postoperative radiation therapy and chemotherapy) for such patients.
In all, 179 patients with stage III-N2 non-small cell lung cancer at MD Anderson Cancer Center were treated with induction chemotherapy followed by surgery from 1998 through 2008; 61 patients in this cohort had persistent, pathologically confirmed, mediastinal nodal disease, and were treated with postoperative radiation therapy. Local-regional failure was defined as recurrence at the surgical site or lymph nodes (levels 1 to 14, including supraclavicular), or both. Overall survival was calculated using the Kaplan-Meier method, and survival outcomes were assessed by log rank tests. Univariate and multivariate Cox proportional hazards models were used to identify factors influencing local-regional failure, distant failure, and overall survival.
All patients received postoperative radiation therapy after surgery, but approximately 25% of the patients also received additional chemotherapy: 9 (15%) with concurrent chemotherapy, 4 (7%) received adjuvant sequential chemotherapy, and 2 (3%) received both. Multivariate analysis indicated that additional postoperative chemotherapy significantly reduced distant failure (hazard ratio 0.183, 95% confidence interval: 0.052 to 0.649, p = 0.009) and improved overall survival (hazard ratio 0.233, 95% confidence interval: 0.089 to 0.612, p = 0.003). However, additional postoperative chemotherapy had no affect on local-regional failure.
Aggressive consolidative therapies may improve outcomes for patients with persistent N2 disease after induction chemotherapy and surgery.
We evaluated the ability of histopathologic response criteria to predict overall survival (OS) and disease-free survival (DFS) in patients with surgically resected non-small cell lung cancer (NSCLC) treated with or without neoadjuvant chemotherapy.
Tissue specimens from 358 patients with NSCLC were evaluated by pathologists blinded to the patient treatment and outcome. The surgical specimens were reviewed for various histopathologic features in the tumor including percentage of residual viable tumor cells, necrosis, and fibrosis. The relationship between the histopathologic findings and OS was assessed.
The percentage of residual viable tumor cells and surgical pathologic stage were associated with OS and DFS in 192 patients with NSCLC receiving neoadjuvant chemotherapy in multivariate analysis (p = 0.005 and p = 0.01, respectively). There was no association of OS or DFS with percentage of viable tumor cells in 166 patients with NSCLC who did not receive neoadjuvant chemotherapy (p = 0.31 and p = 0.45, respectively). Long-term OS and DFS were significantly prolonged in patients who had ≤10% viable tumor compared with patients with >10% viable tumor cells (5 years OS, 85% versus 40%, p < 0.0001 and 5 years DFS, 78% versus 35%, p < 0.001).
The percentages of residual viable tumor cells predict OS and DFS in patients with resected NSCLC after neoadjuvant chemotherapy even when controlled for pathologic stage. Histopathologic assessment of resected specimens after neoadjuvant chemotherapy could potentially have a role in addition to pathologic stage in assessing prognosis, chemotherapy response, and the need for additional adjuvant therapies.
Lung cancer; Neoadjuvant chemotherapy; Histopathology
Clinical factors predicting pulmonary complications after lung resection have been well described, whereas the role of genetics is unknown. The vascular endothelial growth factor (VEGF) signaling pathway has been linked to acute lung injury. We hypothesized that genetic variations in this pathway may be associated with postoperative pulmonary complications after lung resection.
One hundred ninety-six single nucleotide polymorphisms (SNPs) in 17 genes in the VEGF pathway were genotyped in a discovery set of 264 patients and a replication set of 264 patients who underwent lobectomy for lung cancer. Multivariable analysis adjusting for baseline clinical factors was used to identify SNPs associated with pulmonary complications. Cumulative and classification and regression tree (CART) analyses were used to further stratify risk groups.
The overall number of pulmonary complications was 164/528 (31%). The effects of 6 SNPs were consistent in the discovery and replication sets (pooled p value < 0.05). The rs9319425 SNP in the VEGF receptor gene FLT1 resulted in a 1.50-fold increased risk (1.15–1.96; p = 0.003). A cumulative effect for the number of risk genotypes and complications was also evident (p < 0.01). Patients carrying 5 risk genotypes had a 5.76-fold increase in risk (2.73–12.16; p = 4.44 × 10−6). Regression tree analysis identified potential gene-gene interactions between FLT1:rs9319425 and RAF1:rs713178. The addition of the 6 SNPs to the clinical model increased the area under the receiver operating characteristic curve by 6.8%.
Genetic variations in the VEGF pathway are associated with risk of pulmonary complications after lobectomy. This may offer insight into the underlying biological mechanisms of pulmonary complications.
Small cell lung cancer (SCLC) is a highly malignant cancer for which there is no curable treatment and novel therapies are therefore in high demand. In the present study we investigated the therapeutic effect of transcriptionally targeted suicide gene therapy for SCLC based on the yeast cytosine deaminase (YCD) gene alone or fused with the yeast uracil phosphoribosyl transferase (YUPRT) gene followed by administration of 5-fluorocytosine (5-FC) prodrug
The YCD gene or the YCD-YUPRT gene was placed under regulation of the SCLC-specific promoter Insulinoma-associated 1 (INSM1). Therapeutic effect was evaluated in vitro in SCLC cell lines and in vivo in SCLC xenografted nude mice using the non-viral nanoparticle, DOTAP:Cholesterol for transgene delivery.
INSM1-YCD/5-FC and INSM1-YCD-YUPRT/5-FC therapy induced high cytotoxicity in a range of SCLC cell lines. The highest therapeutic effect was obtained from the YCD-YUPRT fusion gene strategy. No cytotoxicity was induced after treatment of cell lines of other origin than SCLC. In addition the INSM1-YCD-YUPRT/5-FC therapy was superior to an established suicide gene system consisting of the Herpes Simplex Virus Thymidine Kinase (HSVTK) gene and prodrug Ganciclovir (GCV). The superior effect was in part due to massive bystander cytotoxicity of YCD-YUPRT-produced toxins. Finally, INSM1-YCD-YUPRT/5-FC therapy induced significant tumor growth delay in SCLC xenografts compared to control treated xenografts.
The current study is the first to test cytosine deaminase-based suicide gene therapy for SCLC and the first to demonstrate an anti-tumor effect from the delivery of suicide gene therapeutics for SCLC in vivo.
gene therapy; transcriptional targeting; Insulinoma-associated 1 promoter; small cell lung cancer; suicide genes
Many cancers can become resistant to repeated administration of even the most effective therapeutic agents. In developing adenoviral mda-7/IL-24 (Ad-mda-7/IL-24) therapy for lung cancer, we have anticipated this potential clinical problem by attempting to identify the molecular mechanisms of Ad-mda7/IL-24 resistance in several Ad-mda7/IL-24-resistant lung cancer cell lines that we have developed. For the present study, we established four Ad-mda7-resistant cell lines by repeated selection of resistant clones of parental Ad-mda7-sensitive A549 cells: two lines (A549R1 and A549R2) resistant to both adenoviral vector and the mda-7 gene and two (A549R3 and A549R4) resistant to the therapeutic mda-7 gene only. As shown by western blot analysis of several known anti-apoptotic proteins, parental A549 and resistant A549R3 cells expressed similar levels of AKT and phosphorylated AKT (p-AKT), whereas resistant A549R3 and A549R4 cells expressed higher levels of bcl-2 and lower levels of bcl-xL than did their parental cells. As shown by flow-cytometric analysis, treating resistant A549R3 and A549R4 cells with a combination of Ad-mda7 and 17-allylamino-17-demethoxygeldanamycin (17AAG) (50 nM) for 48 hours enhanced apoptosis. Together, these in vitro findings indicate that an antiapoptotic mechanism may underlie Ad-mda7 resistance and that such resistance can be overcome by addition of 17AAG. Further investigations along these lines are warranted.
resistant cell lines; apoptosis; MDA-7; adenovirus; gene therapy
Retinoids have shown antiproliferative and chemopreventive activity. We analyzed data from a randomized, placebo-controlled chemoprevention trial to determine whether a 3-month treatment with either 9-cis-retinoic acid (RA) or 13-cis-RA and α-tocopherol reduced Ki-67, a proliferation biomarker, in the bronchial epithelium.
Former smokers (n = 225) were randomly assigned to receive 3 months of daily oral 9-cis-RA (100 mg), 13-cis-RA (1 mg/kg) and α-tocopherol (1200 IU), or placebo. Bronchoscopic biopsy specimens obtained before and after treatment were immunohistochemically assessed for changes in the Ki-67 proliferative index (i.e., percentage of cells with Ki-67–positive nuclear staining) in the basal and parabasal layers of the bronchial epithelium. Per-subject and per–biopsy site analyses were conducted. Multicovariable analyses, including a mixed-effects model and a generalized estimating equations model, were used to investigate the treatment effect (Ki-67 labeling index and percentage of bronchial epithelial biopsy sites with a Ki-67 index ≥ 5%) with adjustment for multiple covariates, such as smoking history and metaplasia. Coefficient estimates and 95% confidence intervals (CIs) were obtained from the models. All statistical tests were two-sided.
In per-subject analyses, Ki-67 labeling in the basal layer was not changed by any treatment; the percentage of subjects with a high Ki-67 labeling in the parabasal layer dropped statistically significantly after treatment with 13-cis-RA and α-tocopherol treatment (P = .04) compared with placebo, but the drop was not statistically significant after 9-cis-RA treatment (P = .17). A similar effect was observed in the parabasal layer in a per-site analysis; the percentage of sites with high Ki-67 labeling dropped statistically significantly after 9-cis-RA treatment (coefficient estimate = −0.72, 95% CI = −1.24 to −0.20; P = .007) compared with placebo, and after 13-cis-RA and α-tocopherol treatment (coefficient estimate = −0.66, 95% CI = −1.15 to −0.17; P = .008).
In per-subject analyses, treatment with 13-cis-RA and α-tocopherol, compared with placebo, was statistically significantly associated with reduced bronchial epithelial cell proliferation; treatment with 9-cis-RA was not. In per-site analyses, statistically significant associations were obtained with both treatments.
Stereotactic ablative radiotherapy (SABR) can achieve excellent local control rates in early-stage non-small cell lung cancer (NSCLC) and has emerged as a standard treatment option for patients who cannot undergo surgery or those with isolated recurrences. However, factors that may predict toxicity or survival are largely unknown. We sought here to identify predictors of survival and pneumonitis after SABR for NSCLC in a relatively large single-institution series.
Subjects were 130 patients with stage I NSCLC treated with four-dimensional computed tomography (4D CT) –planned, on-board volumetric image–guided SABR to 50 Gy in 4 fractions. Disease was staged by positron emission tomography/computed tomography (PET/CT) and scans were obtained again at the second follow-up after SABR.
At a median follow-up time of 26 months, the 2-year local control rate was 98.5%. The median overall survival (OS) time was 60 months, and OS rates were 93.0% at 1 year, 78.2% at 2 years, and 65.3% at 3 years. No patient experienced grade 4–5 toxicity; 15 had radiation pneumonitis (12 [9.3%] grade 2 and 3 [2.3%] grade 3). Performance status, standardized uptake value (SUV)max on staging PET/CT, tumor histology, and disease operability were associated with OS on univariate analysis, but only staging SUVmax was independently predictive on multivariate analysis (P = 0.034). Dosimetric factors were associated with radiation pneumonitis on univariate analysis, but only mean ipsilateral lung dose ≥9.14 Gy was significant on multivariate analysis (P = 0.005).
OS and radiation pneumonitis after SABR for stage I NSCLC can be predicted by staging PET SUVmax and ipsilateral mean lung dose, respectively.
Stereotactic body radiotherapy; Stereotactic ablative radiotherapy; Non-small cell lung cancer; F-fluorodeoxyglucose positron emission tomography; Toxicity; Predictive factors
The requirement of frozen tissues for microarray experiments limits the clinical usage of genome-wide expression profiling using microarray technology. The goal of this study is to test the feasibility of developing lung cancer prognosis gene signatures using genome-wide expression profiling of formalin-fixed paraffin-embedded (FFPE) samples, which are widely available and provide a valuable rich source for studying the association of molecular changes in cancer and associated clinical outcomes.
We randomly selected 100 Non-Small-Cell lung cancer (NSCLC) FFPE samples with annotated clinical information from the UT-Lung SPORE Tissue Bank. We micro dissected tumor area from FFPE specimens, and used Affymetrix U133 plus 2.0 arrays to attain gene expression data. After strict quality control and analysis procedures, a supervised principal component analysis was used to develop a robust prognosis signature for NSCLC. Three independent published microarray data sets were used to validate the prognosis model.
This study demonstrated that the robust gene signature derived from genome-wide expression profiling of FFPE samples is strongly associated with lung cancer clinical outcomes, can be used to refine the prognosis for stage I lung cancer patients and the prognostic signature is independent of clinical variables. This signature was validated in several independent studies and was refined to a 59-gene lung cancer prognosis signature.
We conclude that genome-wide profiling of FFPE lung cancer samples can identify a set of genes whose expression level provides prognostic information across different platforms and studies, which will allow its application in clinical settings.
Lung Cancer Prognosis; Gene Expression Signature; Formalin Fixed Paraffin Embedded Samples
Activating enhancer-binding protein-2β (AP2β) is a transcription factor involved in apoptosis. The purpose of the current study was to assess the cellular location and level of AP2β in Non-Small Cell Lung Cancer (NSCLC) and normal lung tissue and investigate whether the level and localization of AP2β expression is predictive of overall survival in patients with stage I NSCLC.
We performed immunohistochemical analysis of tissue microarrays (TMAs) prepared from stage I NSCLC specimens with adjacent normal lung tissue from two independent sets of patients who underwent lung resection with curative intent at our institution. AP2β intensity was assessed in TMAs, and AP2β staining patterns were classified as either diffuseor nucleolar in the TMAs. AP2β intensity and localization were analyzed for correlation with patients' survival.
Immunohistochemical analysis of TMAs showed that the intensity of AP2β immunohistochemical staining did not correlate with overall survival. When location of AP2β was analyzed in TMAs, all of the normal lung tissue had diffuse pattern of AP2β. In the first set of NSCLC, patients with nucleolar pattern had a significantly lower 5-year survival rate than patients with diffuse pattern (67% vs. 100%; P = 0.004); this finding was confirmed in the second set (64% vs. 91%; P = 0.02). Multivariate analysis revealed that nucleolar pattern was an independent predictor of poor overall survival in both sets.
The AP2β which is located in the nucleoplasm in normal lung tissue is found in either nucleoplasm or nucleoli in NSCLC. The patients with AP2β in the nucleoli had poor survival compared to patients with AP2β in the cytoplasm.
Lung cancer biology; survival analysis
AZD6244 is a small molecule inhibitor of the MEK kinase pathway currently in clinical trials. However, the mechanisms mediating intrinsic resistance to MEK inhibition are not fully characterized. To define molecular mechanisms of MEK inhibitor resistance, we analyzed responses of 38 lung cancer cell lines following AZD6244 treatment and their genome-wide gene expression profiles and identified a panel of genes correlated with sensitivity or resistance to AZD6244 treatment. In particular, Ingenuity pathway analysis revealed that activation of the STAT3 pathway was associated with MEK inhibitor resistance. Inhibition of this pathway by JSI-124, a STAT3-specific small molecule inhibitor, or with STAT3-specific siRNA sensitized lung cancer cells to AZD6244 and induced apoptosis. Moreover, combining a STAT3 inhibitor with AZD6244 induced expression of BIM and polyADP-ribose polymerase (PARP) cleavage, whereas activation of the STAT3 pathway inhibited BIM expression and elicited resistance to MEK inhibitors. We found that the STAT3-regulated microRNA miR-17 played a critical role in MEK inhibitor resistance, such that miR-17 inhibition sensitized resistant cells to AZD6244 by inducing BIM and PARP cleavage. Together, these results indicated that STAT3-mediated overexpression of miR-17 blocked BIM expression and caused resistance to AZD6244. Our findings suggest novel approaches to overcome resistance to MEK inhibitors by combining AZD6244 with STAT3 or miR-17 inhibitors.
Gene expression profiling; MEK inhibitor resistance; AZD6244; STAT3 pathway; miR-17