The anti-proliferative effects of 1α,25-dihydroxyvitamin D3 (1,25-D3, calcitriol, the active form of vitamin D) are mediated by the nuclear vitamin D receptor (VDR). In the present study, we characterized VDR expression in lung adenocarcinoma (AC).
We examined VDR mRNA expression using a quantitative real-time PCR (qRT-PCR) in 100 patients who underwent surgery for lung AC. In a subset of these patients (n = 89), we examined VDR protein expression using immunohistochemistry. We also examined the association of VDR protein expression with circulating serum levels of 25-hydroxyvitamin D3 (25-D3) and 1,25-D3. The antiproliferative effects and cell cycle arrest of 1,25-D3 were examined using lung cancer cell lines with high (SKLU-1) as well as low (A549) expression of VDR mRNA.
Higher VDR expression correlates with longer survival after adjusting for age, sex, disease stage and tumor grade (HR 0.73, 95% CI 0.58–0.91). In addition, there was a positive correlation (r = 0.38) between serum 1,25-D3 and tumor VDR protein expression. A greater anti-proliferative effect of 1,25-D3 was observed in high compared to low VDR-expressing cell lines; these effects corresponded to G1 cell cycle arrest; this was associated with a decline in cyclin D1, S-phase kinase protein 2 (Skp2), retinoblastoma (Rb) and minichromosome maintenance 2 (MCM2) proteins involved in S-phase entry.
Increased VDR expression in lung AC is associated with improved survival. This may relate to a lower proliferative status and G1 arrest in high VDR-expressing tumors.
VDR; Vitamin D; 1,25-D3; Lung Adenocarcinoma; Survival
This study aimed to (1) examine changes in dyspnea, global pulmonary function test (PFT) results, and functional activity on ventilation (V)/perfusion (Q) single-photon emission computerized tomography (SPECT) scans during the course of radiation (RT), and (2) factors associated with the changes in patients with non-small-cell lung cancer (NSCLC).
Methods and Materials
Fifty-six stage I to III NSCLC patients treated with definitive RT with or without chemotherapy were enrolled prospectively. Dyspnea was graded according to Common Terminology Criteria for Adverse Events version 3.0 prior to and weekly during RT. V/Q SPECT-computed tomography (CT) and PFTs were performed prior to and during RT at approximately 45 Gy. Functions of V and Q activities were assessed using a semiquantitative scoring of SPECT images.
Breathing improved significantly at the third week (mean dyspnea grade, 0.8 vs. 0.6; paired t-test p = 0.011) and worsened during the later course of RT (p > 0.05). Global PFT results did not change significantly, while regional lung function on V/Q SPECT improved significantly after ~45 Gy. The V defect score (DS) was 4.9 pre-RT versus 4.3 during RT (p = 0.01); Q DS was 4.3 pre-RT versus 4.0 during RT (p < 0.01). Improvements in V and Q functions were seen primarily in the ipsilateral lung (V DS, 1.9 pre-RT versus 1.4 during RT, p < 0.01; Q DS, 1.7 pre-RT versus 1.5 during RT, p < 0.01). Baseline primary tumor volume was significantly correlated with pre-RT V/Q DS (p < 0.01). Patients with central lung tumors had greater interval changes in V and Q than those with more peripheral tumors (p < 0.05 for both V and Q DS).
Regional ventilation and perfusion improved during RT at 45 Gy. This suggests that adaptive planning based on V/Q SPECT during RT may allow sparing of functionally recoverable lung tissue.
Non-small-cell lung cancer; Perfusion; Radiotherapy; Single-photon emission computerized tomography; Ventilation
This prospective study aimed to develop a robust and clinically-applicable method to identify high-risk early stage lung cancer patients and then to validate this method for use in future translational studies.
Patients and Methods
Three published Affymetrix microarray data sets representing 680 primary tumors were used in the survival-related gene selection procedure using clustering, Cox model and random survival forest (RSF) analysis. A final set of 91 genes was selected and tested as a predictor of survival using a qRT-PCR-based assay utilizing an independent cohort of 101 lung adenocarcinomas.
The RSF model built from 91 genes in the training set predicted patient survival in an independent cohort of 101 lung adenocarcinomas, with a prediction error rate of 26.6%. The mortality risk index (MRI) was significantly related to survival (Cox model p < 0.00001) and separated all patients into low, medium, and high-risk groups (HR = 1.00, 2.82, 4.42). The MRI was also related to survival in stage 1 patients (Cox model p = 0.001), separating patients into low, medium, and high-risk groups (HR = 1.00, 3.29, 3.77).
The development and validation of this robust qRT-PCR platform allows prediction of patient survival with early stage lung cancer. Utilization will now allow investigators to evaluate it prospectively by incorporation into new clinical trials with the goal of personalized treatment of lung cancer patients and improving patient survival.
Lung cancer; qRT-PCR; Prognosis
Perfusion (Q) single photon emission computerized tomography (SPECT) has been used to divert dose away from higher-functioning lung during radiation therapy (RT) planning. This study aimed to 1) study regional lung function through co-registered pulmonary ventilation/perfusion (V/Q) SPECT-CT, and 2) classify these defects for its potential value in radiation planning in patients with non-small cell lung cancer (NSCLC).
Patients with stages I-III NSCLC requiring radiation-based therapy were eligible for this prospective study. V/Q SPECT performed within 2 weeks prior to radiation start was interpreted by nuclear medicine physicians and then measured by a semi-quantitative score. The potential mechanism of V, Q defect was analyzed; the potential impact of V/Q SPECT over Q SPECT alone was completed through classified applications (high dose RT versus RT avoidance) during planning.
Images of 51 consecutive patients were analyzed. The V, Q defects were matched, reverse mismatched (V- defect greater than Q-defect), and mismatched (Q-defect greater than V-defect) in 61%, 31% and 8% patients, respectively. Tumor was the leading cause of the defects of ipsilateral lung in 73% patients. The defect scores of the ipsilateral lung were greater in patients with central primaries than those with peripheral primaries for both V- (2.3±1.1 vs. 1.5±0.8, p=0.017) and Q-SPECT (2.2±0.8 vs. 1.4±0.6, p=0.000). The patients with chronic obstructive pulmonary disease had greater defect scores in contralateral lung for both V- (1.5±0.7 vs. 1.0±0.8, p=0.006) and Q- SPECT (1.4±0.6 vs. 1.0±0.4, p=0.010). On assessing the potential value of SPECT on RT plan, 39% patients could have their RT plan if applying V/Q SPECT rather than Q SPECT alone.
V/Q SPECT provides a more comprehensive functional assessment, may provide additional value over Q-SPECT alone in assessing local pulmonary function and guide RT plan decisions in patients with NSCLC.
Non-small cell lung cancer; Ventilation; Perfusion; Single photon emission computerized tomography (SPECT); Radiotherapy
The active form of vitamin D, 1α,25-dihydroxyvitamin D3 (1,25-D3) exerts antiproliferative effects in cancers, including lung adenocarcinoma (AC). CYP24A1 is overexpressed in many cancers and catabolizes 1,25-D3. The purpose of our study was to assess CYP24A1 as a prognostic marker and to study its relevance to antiproliferative activity of 1,25-D3 in lung AC cells.
Tumors and corresponding normal specimens from 86 patients with lung AC (stages I–III) were available. AffymetrixR array data and subsequent confirmation by quantitative real time-PCR were used to determine CYP24A1 mRNA expression. A subsequent validation set of 101 lung AC was used to confirm CYP24A1 mRNA expression and its associations with clinical variables. The antiproliferative effects of 1,25-D3 were examined using lung cancer cell lines with high as well as low expression of CYP24A1 mRNA.
CYP24A1 mRNA was elevated 8–50 fold in lung AC (compared to normal nonneoplastic lung) and significantly higher in poorly-differentiated cancers. At 5 years of follow-up, the probability of survival was 42% (high CYP24A1, n = 29) versus 81% (low CYP24A1, n = 57) (P = 0.007). The validation set of 101 tumors showed that CYP24A1 was independently prognostic of survival (multivariate Cox model adjusted for age, gender and stage, P = 0.001). A549 cells (high CYP24A1) were more resistant to antiproliferative effects of 1,25-D3 compared with SKLU-1 cells (low CYP24A1).
CYP24A1 overexpression is associated with poorer survival in lung AC. This may relate to abrogation of antiproliferative effects of 1,25-D3 in high CYP24A1 expressing lung AC.
SRC is an oncogene with an essential role in the invasiveness and metastasis of solid tumors including small cell lung cancer (SCLC). Dasatinib is a potent inhibitor of SRC as well as other tyrosine kinases. The primary objective of this study was to determine the efficacy of second-line dasatinib in patients with chemo-sensitive (relapse or progression ≥90 days after completing first-line therapy) SCLC.
Patients and Methods:
Patients with measurable disease, performance status (PS) 0-1, no more than 1 prior platinum-based chemotherapy regimen, and adequate hematologic, hepatic, and renal function were eligible. Dasatinib was administered orally at 70 mg twice daily continuously (1 cycle = 21 days) until disease progression or unacceptable toxicity. Response was determined after every 2 cycles. Patients were followed until disease progression or death. The study was prospectively designed to simultaneously discriminate between complete plus partial response rates of 5% versus 20% and progression-free survival (PFS) rates at 6 weeks of 50% versus 70.7% in 53 evaluable patients with at least 92% power. The study was to be terminated early and declared negative if 1 or less objective response and 14 or fewer instances of PFS ≥ 6 weeks were observed among the initial 27 patients; however, patient accrual continued while the initial 27 patients were evaluated.
Between 4/2007 and 12/2008, 45 patients were enrolled, but one patient never received any protocol therapy and one patient was ineligible: male/female, 17/26; white/black/unknown, 40/2/1; median age, 64 (range, 35-84) years; and PS 0/1, 12/31. No objective response was recorded among the 43 eligible and treated patients. Among the initial 27 patients, only 13 instances of PFS ≥ 6 weeks were observed. With a median follow up time of 7.1 months, median estimated overall survival and PFS times for the 43 eligible and treated patients were 17.0 and 5.9 weeks, respectively. Common reasons for removal of patients from protocol treatment were progressive disease (65%) and adverse events (26%). Toxicity was generally mild to moderate: grade 3 events of >5% frequency included fatigue, and pleural and pericardial effusions; and no grade 4 or 5 events were encountered.
Dasatinib did not reach our specified efficacy criteria in this clinical setting, and the study was terminated.
Phase II; Dasatinib; Small cell lung cancer
African Americans have higher incidence and poorer response to lung cancer treatment compared with Caucasians. However, the underlying molecular mechanisms for the significant ethnic difference are not known. The present study examines the ethnic differences in the type and frequency of MET proto-oncogene (MET) mutation in lung cancer and correlated them with other frequently mutated genes such as epidermal growth factor receptor (EGFR), KRAS2, and TP53.
Using tumor tissue genomic DNA from 141 Asian, 76 Caucasian, and 66 African American lung cancer patients, exons coding for MET and EGFR were PCR amplified, and mutations were detected by sequencing. Mutation carriers were further screened for KRAS2 and TP53 mutations. Functional implications of important MET mutations were explored by molecular modeling and hepatocyte growth factor binding studies.
Unlike the frequently encountered somatic mutations in EGFR, MET mutations in lung tumors were germline. MET-N375S, the most frequent mutation of MET, occurred in 13% of East Asians compared with none in African Americans. The frequency of MET mutations was highest among male smokers and squamous cell carcinoma. The MET-N375S mutation seems to confer resistance to MET inhibition based on hepatocyte growth factor ligand binding, molecular modeling, and apoptotic susceptibility to MET inhibitor studies.
MET in lung cancer tissues contained nonsynonymous mutations in the semaphorin and juxtamembrane domains but not in the tyrosine kinase domain. All the MET mutations were germline. East Asians, African-Americans, and Caucasians had different MET genotypes and haplotypes. MET mutations in the semaphorin domain affected ligand binding.
Smoking is associated with both acute myeloid leukemia (AML) and lung cancer. We therefore searched our database for concomitant presentation of AML and lung cancer. Among 775 AML cases and 5225 lung cancer cases presenting to Roswell Park Cancer Institute between the years January 1992 and May 2008 we found 12 (1.5% of AML cases; 0.23% of lung cancer cases) cases (seven metachronous and five synchronous) with AML and lung cancer. All but one patient were smokers. There were no unique characteristic of either AML or lung cancer in these patients. Nine patients succumbed to AML, one died from an unrelated cause while undergoing treatment for AML, one died of lung cancer and one patient is alive after allogeneic transplantation for AML. In summary, this study supports the need for effective smoking cessation programs.
Acute myeloid leukemia; lung cancer; smoking
In Cancer and Leukemia Group B 39801, we evaluated whether induction chemotherapy before concurrent chemoradiotherapy would result in improved survival, and demonstrated no significant benefit from the addition of induction chemotherapy. The primary objective of this analysis was to dichotomize patients into prognostic groups using factors predictive of survival, and to investigate if induction chemotherapy was beneficial in either prognostic group.
Patients and Methods
A Cox proportional hazard model was used to assess the impact on survival of the following factors: (≥ 70 vs. < 70 years), gender, race, stage (IIIB vs. IIIA), hemoglobin (hgb) (< 13 vs. ≥13 g/dl), performance status (PS) (1 vs.0), weight loss (≥5% vs. < 5%), treatment arm, and the interaction between weight loss and hgb.
Factors predictive of decreased survival were weight loss ≥ 5%, age ≥ 70 years, PS of 1, and hgb < 13 g/dl (p<0.05). Patients were classified as having ≥2 poor prognostic factors (n=165) or ≤ 1 factor (n=166). The hazard ratio (HR) for overall survival for the patients with ≥ 2 versus patients with ≤ 1 was 1.88 (95% CI, 1.49 to 2.37; p= < 0.0001); median survival times observed were 9 (95% CI, 8 to 11) and 18 (95% CI, 16 to 24) months, respectively. There was no significant difference in survival between treatment arms in patients with ≥ 2 factors (HR=0.86, 95% CI, 0.63 to 1.17; p=0.34) or ≤1 factor (HR=0.97, 95% CI, 0.70 to 1.35; p=0.87)
There is no evidence that induction chemotherapy is beneficial in either prognostic group.
locally advanced non-small cell lung cancer; combined modality therapy; chemoradiation; CALGB; prognostic factors; induction chemotherapy
Lung tumor xenografts grown in immunocompromised mice provide a renewable source of tumor tissue for research and a means to study individualized response to chemotherapy. Critical to this utility is verification that the xenograft cells retain core phenotypic characteristics of the original tumor. We compared eight non-small cell lung carcinomas with their corresponding xenografts grown in mice with severe combined immunodeficiency by way of histology, immunohistochemistry, and microRNA expression profiling. Six of the eight xenografts closely resembled their original tumor by light microscopy. The xenografts also largely retained key immunophenotypic features. With expression profiling of human microRNAs, however, xenografts clustered separately from the original tumors. While this may be partly due to contamination by non-neoplastic human and mouse stroma, the results suggest that miRNA expression may be altered in xenografts and that this possibility should be further evaluated.
gene expression; immunophenotype; lung carcinoma; microRNA; xenografts
Growing evidence suggests that survivin expression in cancer cell nuclei may represent an important prognostic marker to predict disease outcome for cancer patients. Current reports in this research area, however, are inconsistent and propose opposing conclusions regarding the significance and prognostic value of survivin nuclear expression. The aim of our study is to review and discuss the data reported in the original publications. We have also provided new experimental data to support our view regarding the possible reasons for the observed inconsistencies in the literature. This would alert researchers to pay attention to potential pitfalls in the determination of nuclear or cytoplasmic expression of survivin for the future.
survivin expression; cancer; cytoplasmic; nuclear; immunohistochemistry; prognostic marker
Although it was observed that inhibition of the antiapoptotic protein survivin expression in lung cancer cells induces apoptosis, the expression and role of survivin variants (survivin-2B and survivin-ΔEx3) in lung cancer have not yet been characterized. We analyzed 24 non-small-cell lung cancer (NSCLC) samples by semi-quantitative RT-PCR. Surprisingly, our results revealed that high-level expression of survivin-2B is significantly associated with the patient category of “no relapse and alive” (p-value < 0.0001). In contrast, high-level expression of survivin-ΔEx3 is highly associated with the patient category of “relapse and dead” (p-value < 0.0001). Consistent with this observation, exogenous expression of survivin-2B in A549 lung cancer cells inhibited cell growth, disrupted the mitochondria potential, and induced apoptotic cell death, while expression of survivin-ΔEx3 protected the mitochondria potential and facilitated cell survival. These findings provide evidence that survivin-2B and survivin-ΔEx3 play opposite roles in disease relapse and NSCLC cell survival, which is likely through the differential modulation of mitochondrial potential. Thus, controlling the differential expression of survivin-2B and survivin-ΔEx3 may represent novel approaches for cancer therapeutics in NSCLC.
Survivin-2B; Survivin-ΔEx3; Non-small-cell lung cancer
MET receptor tyrosine kinase and its ligand hepatocyte growth factor (HGF) regulate a variety of cellular functions, many of which can be dysregulated in human cancers. Activated MET signaling can lead to cell motility and scattering, angiogenesis, proliferation, branching morphogenesis, invasion, and eventual metastasis. We performed systematic analysis of the expression of the MET receptor and its ligand HGF in tumor tissue microarrays (TMA) from human solid cancers. Standard immunohistochemistry and a computerized automated scoring system were used. DNA sequencing for MET mutations in both non-kinase and kinase domains was also performed. MET was differentially overexpressed in human solid cancers. The ligand HGF was widely expressed in both tumor, primarily intra-tumoral, and non-malignant tissues. The MET/HGF likely is functional and may be activated in autocrine fashion in vivo. MET and SCF were found to be positively stained in the bronchioalevolar junctions of lung tumors. A number of novel mutations of MET were identified, particularly in the extracellular semaphorin domain and the juxtamembrane domain. MET-HGF pathway can be assayed in TMAs and is often overexpressed in a wide variety of human solid cancers. MET can be activated through overexpression, mutation, or autocrine signaling in malignant cells. Mutations in the non-kinase regions of MET might play important role in tumorigenesis and tumor progression. MET would be an important therapeutic anti-tumor target to be inhibited, and in lung cancer, MET may represent a cancer early progenitor cell marker.
Calcitriol potentiates cisplatin-mediated activity in a variety of tumor models. We examine here, the effect of calcitriol and cisplatin pre-clinically and clinically in canine spontaneous tumors through in vitro studies on tumor cells and through a phase I study of calcitriol and cisplatin to identify the maximum-tolerated dosage (MTD) of this combination in dogs with cancer and to characterize the pharmacokinetic disposition of calcitriol in dogs.
Canine tumor cells were investigated for calcitriol/cisplatin interactions on proliferation using an MTT assay in a median-dose effect analysis; data were used to derive a combination index (CI). Cisplatin was given at a fixed dosage of 60 mg/m2. Calcitriol was given i.v. and the dosage was escalated in cohorts of three dogs until the MTD was defined. Serum calcitriol concentrations were quantified by radioimmunoassay.
In vitro, CIs<1.0 were obtained for all combinations of calcitriol/cisplatin examined. The MTD was 3.75 μg/kg calcitriol in combination with cisplatin, and hypercalcemia was the dose-limiting toxicosis. The relationship between calcitriol dosage and either Cmax or AUC was linear. Calcitriol dosages >1.5 μg/kg achieved Cmax ≥ 9.8 ng/mL and dosages >1.0 μg/kg achieved AUC ≥ 45 h ng/mL.
Calcitriol and cisplatin have synergistic antiproliferative effects on multiple canine tumor cells and high-dosages of i.v. calcitriol in combination with cisplatin can be safely administered to dogs. Cmax and AUC at the MTD 3.75 μg/kg calcitriol exceed concentrations associated with antitumor activity in a murine model, indicating this combination might have significant clinical utility in dogs.
Vitamin D; 1,25-Dihydroxyvitamin D3; Platinum; Canine; Cancer; Pharmacokinetics
Radiation pneumonitis is an unpredictable complication of radiotherapy for lung cancer and a condition which can cause significant morbidity. The ability to identify patients at a high risk of developing pneumonitis is critical, since it will enable the individualization of the treatment plan. Because the cytotoxic effect of radiation is propagated through ROS and ROS-driven oxidative stress, the role of anti-oxidant defense systems in radiation pneumonitis was investigated. Using the pneumonitis-sensitive C3H/HeN mice as a model, we demonstrated that the anti-oxidant response of the lung correlated well with that of RBC. We then proceeded to test whether differences of RBC anti-oxidant response would predict the pneumonitis development in patients. SOD, GPX, CAT activities and glutathione in RBC were measured at baseline and then weekly for 6 weeks of treatment in fifteen eligible patients receiving concurrent chemo-radiotherapy for unresectable stage III NSCLC. Striking differences were found in the anti-oxidant activities of RBC with respect to the pneumonitis development. Those who developed pneumonitis showed higher SOD and lower GPX activities at baseline compared to those who did not (3.7 vs. 6.8 unit/mg for median SOD, 16.5 vs. 10.7 nmol/min/mg for median GPX). The functional imbalance of SOD and GPX was displayed consistently throughout the treatment period. The sensitivity and specificity of pneumonitis prediction were further increased when the GPX/SOD ratio was analyzed (pre-treatment P = 0.0046). Our results provide a strong rationale to monitor SOD and GPX activities of RBC to identify patients who are at risk of developing pneumonitis, and to implement a strategy of increasing the GPX/SOD ratio in order to lower the risk.
Radiotherapy; Lung cancer; Radiation pneumonitis; RBC; Anti-oxidant system; SOD activity; GPX activity
Uncontrolled proliferation and increased motility are hallmarks of neoplastic cells, therefore markers of proliferation and motility may be valuable in assessing tumor progression and prognosis. MCM2 is a member of the minichromosome maintenance (MCM) protein family. It plays critical roles in the initiation of DNA replication and in replication fork movement, and is intimately related to cell proliferation. Ki-67 is a proliferation antigen that is expressed during all but G0 phases of the cell cycle. Gelsolin is an actin-binding protein that regulates the integrity of the actin cytoskeletal structure and facilitates cell motility. In this study, we assessed the prognostic significance of MCM2 and Ki-67, two markers of proliferation, and gelsolin, a marker of motility, in non-small cell lung cancer (NSCLC).
128 patients with pathologically confirmed, resectable NSCLC (stage I-IIIA) were included. Immunohistochemistry was utilized to measure the expressions of these markers in formalin-fixed, paraffin-embedded tumor tissues. Staining and scoring of MCM2, Ki-67 and gelsolin was independently performed. Analyses were performed to evaluate the prognostic significance of single expression of each marker, as well as the prognostic significance of composite expressions of MCM2 and gelsolin. Cox regression and Kaplan-Meier survival analysis were used for statistical analysis.
Of the three markers, higher levels of gelsolin were significantly associated with an increased risk of death (adjusted RR = 1.89, 95% CI = 1.17–3.05, p = 0.01), and higher levels of MCM2 were associated with a non-significant increased risk of death (adjusted RR = 1.36, 95% CI = 0.84–2.20, p = 0.22). Combined, adjusted analyses revealed a significantly poor prognostic effect for higher expression of MCM2 and gelsolin compared to low expression of both biomarkers (RR = 2.32, 95% CI = 1.21–4.45, p = 0.01). Ki-67 did not display apparent prognostic effect in this study sample.
The results suggest that higher tumor proliferation and motility may be important in the prognosis of NSCLC, and composite application of biomarkers might be of greater value than single marker application in assessing tumor prognosis.