Prospective studies focusing on EGFR inhibitors in African Americans with NSCLC have not been previously performed. In this phase II randomized study, 55 African Americans with NSCLC received erlotinib 150mg/day or a body weight adjusted dose with subsequent escalations to the maximum allowable, 200mg/day, to achieve rash. Erlotinib and OSI-420 exposures were lower compared to previous reports, consistent with CYP3A pharmacogenetics implying higher metabolic activity. Tumor genetics revealed only two EGFR mutations, EGFR amplification in 17/47 samples, 8 KRAS mutations and 5 EML4-ALK translocations. Although absence of rash was associated with shorter time to progression (TTP), disease control rate, TTP, and 1-year survival were not different between the two dose groups, indicating the dose-to-rash strategy failed to increase clinical benefit. Observed low incidence of toxicity and low erlotinib exposure suggest standardized and maximum allowable dosing may be suboptimal in African Americans.
EGFR; Erlotinib; African American; Pharmacokinetics; Pharmacogenetics
Alveolar rhabdomyosarcoma that harbors the PAX3/FOXO1 fusion gene (t-ARMS) is a common and lethal subtype of this childhood malignancy. Improvement in clinical outcomes in this disease is predicated upon the identification of novel therapeutic targets.
Robust mouse models were used for in vivo analysis, and molecular studies were performed on xenografts treated in parallel. Two independent patient sets (n=101 and 124) of clinically-annotated tumor specimens were used for analysis of FANCD2 levels and its association with clinical and molecular characteristics and outcomes.
Our xenograft studies reveal a selective suppression of FANCD2 by m-TOR kinase inhibition and radiosensitization of the t-ARMS line only. In the initial patient set, we show FANCD2 transcript levels are prognostic in univariate analysis, and are significantly associated with metastatic disease and that the co-presence of the translocation and high expression of FANCD2 is independently prognostic. We also demonstrate a significant and non-random enrichment of mTOR-associated genes that correlate with FANCD2 gene expression within the t-ARMS samples, but not within other cases. In the second patient set, we show that on a protein level, FANCD2 expression correlates with PAX3/FOXO1 fusion gene and is strongly associated with phospho-P70S6K expression in cases with the fusion gene.
Our data demonstrate that FANCD2 may have a significant role in the radiation resistance and virulence of t-ARMS. Indirectly targeting this DNA repair protein, through mTOR inhibition, may represent a novel and selective treatment strategy.
rhabdomyosarcoma; PAX3/FOXO1 fusion gene; FANCD2; mTOR; radioresistance
Molecular selection has led to the successful use of novel tyrosine kinase inhibitors (TKIs) in non-small-cell lung cancers (NSCLCs). For instance, mutations in EGFR and translocations and fusions in ALK render tumor cells sensitive to some TKIs, leading to substantial clinical benefits. Molecular testing such as DNA sequencing or fragment analysis following PCR, and evaluation of copy number and gene positioning by FISH, have been developed and used clinically to identify mutations/fusions. Meanwhile, TKIs to target actionable mutations/fusions in several other oncogenes are being evaluated. High-throughput sequencing can provide therapy-predictive information as well as identify novel targetable genomic alterations. In this article, we report our experience enabling single-gene testing, and our evolution to panel-based next-generation sequencing.
ALK; BRAF; EGFR; next-generation sequencing; NSCLC; targeted exon capture
We performed a genome-wide association (GWA) study in 434 sporadic Creutzfeldt-Jakob disease (sCJD) patients and 1939 controls from the United Kingdom, Germany and The Netherlands. The findings were replicated in an independent sample of 1109 sCJD and 2264 controls provided by a multinational consortium. From the initial GWA analysis we selected 23 SNPs for further genotyping in 1109 sCJD cases from seven different countries. Five SNPs were significantly associated with sCJD after correction for multiple testing. Subsequently these five SNPs were genotyped in 2264 controls. The pooled analysis, including 1543 sCJD cases and 4203 controls, yielded two genome wide significant results: rs6107516 (p-value=7.62x10-9) a variant tagging the prion protein gene (PRNP); and rs6951643 (p-value=1.66x10-8) tagging the Glutamate Receptor Metabotropic 8 gene (GRM8). Next we analysed the data stratifying by country of origin combining samples from the pooled analysis with genotypes from the 1000 Genomes Project and imputed genotypes from the Rotterdam Study (Total n=12967). The meta-analysis of the results showed that rs6107516 (p-value=3.00x10-8) and rs6951643 (p-value=3.91x10-5) remained as the two most significantly associated SNPs. Rs6951643 is located in an intronic region of GRM8, a gene that was additionally tagged by a cluster of 12 SNPs within our top100 ranked results. GRM8 encodes for mGluR8, a protein which belongs to the metabotropic glutamate receptor family, recently shown to be involved in the transduction of cellular signals triggered by the prion protein. Pathway enrichment analyses performed with both Ingenuity Pathway Analysis and ALIGATOR postulates glutamate receptor signalling as one of the main pathways associated with sCJD. In summary, we have detected GRM8 as a novel, non-PRNP, genome-wide significant marker associated with heightened disease risk, providing additional evidence supporting a role of glutamate receptors in sCJD pathogenesis.
Functional alterations in Rad51C are the cause of the Fanconi anemia complementation group O (FANCO) gene disorder. We have identified novel splice variants of Rad51C mRNA in colorectal tumors and cells. The alternatively spliced transcript variants are formed either without exon-7 (variant 1), without exon 6 and 7 (variant 2) or without exon 7 and 8 (variant 3).
Real time PCR analysis of nine pair-matched colorectal tumors and non-tumors showed that variant 1 was overexpressed in tumors compared to matched non-tumors. Among 38 colorectal tumor RNA samples analyzed, 18 contained variant 1, 12 contained variant 2, 14 contained variant 3, and eight expressed full length Rad51C exclusively. Bisulfite DNA sequencing showed promoter methylation of Rad51C in tumor cells. 5-azacytidine treatment of LS-174T cells caused a 14 fold increase in variant 1, a 4.8 fold increase for variant 3 and 3.4 fold for variant 2 compared to 2.5 fold increase in WT.
Expression of Rad51C variants is associated with FANCD2 foci positive colorectal tumors and is associated with microsatellite stability in those tumors. Further investigation is needed to elucidate differential function of the Rad51C variants to evaluate potential effects in drug resistance and DNA repair.
Rad51C isoform overexpression; Promoter methylation; Colorectal tumors
Second-line chemotherapy for advanced non-small cell lung cancer (NSCLC) improves survival modestly but new strategies are needed. This trial was designed to evaluate an antivascular endothelial growth factor strategy with or without standard chemotherapy in previously treated NSCLC.
Patients with stage IIIB/IV NSCLC with performance status 0 to 1 progressive after first-line chemotherapy were eligible for randomization to pemetrexed, sunitinib, or the combination. Patients were stratified by performance status, stage, and sex. Primary objective was 18-week progression-free survival (PFS) rate; secondary objectives included response, overall survival (OS), and toxicity. Target accrual was 225. The study was terminated early because of decreasing accrual rates.
Between April 2008 and September 2011, 130 patients were registered and randomized; of this, 125 patients were treated. Baseline characteristics in the three arms were well balanced. Toxicity was higher in the sunitinib-containing arms. The 18-week PFS rate in the pemetrexed, sunitinib, and combination arms was 54% (95% confidence interval [CI], 40–71), 37% (95% CI, 25–54), and 48% (95% CI, 35–66), respectively (p= 0.25). Median PFS in the pemetrexed, sunitinib, and combination arms in months was 4.9 (2.1–8.8), 3.3 (2.3–4.2), and 3.7 (2.5–5.8), respectively (p= 0.18). There was an overall statistically significant difference in OS between the three arms: median OS in months was 10.5 (8.3–20.2) for pemetrexed, 8.0 (6.8–13.5) for sunitinib, and 6.7 (4.1–10.1) for the combination (p= 0.03).
Pemetrexed had a superior toxicity profile to either sunitinib or the combination of pemetrexed and sunitinib. The 18-week PFS rate was not significantly different between the arms. OS was significantly better with pemetrexed alone compared with the two sunitinib-containing arms, with the doublet performing worst for OS.
CALGB 30704; Lung cancer
Familial Alzheimer’s disease (AD), mostly associated with early onset, is caused by mutations in three genes (APP, PSEN1, and PSEN2) involved in the production of the amyloid β peptide. In contrast, the molecular mechanisms that trigger the most common late onset sporadic AD remain largely unknown. With the implementation of an increasing number of case-control studies and the upcoming of large-scale genome-wide association studies there is a mounting list of genetic risk factors associated with common genetic variants that have been associated with sporadic AD. Besides apolipoprotein E, that presents a strong association with the disease (OR∼4), the rest of these genes have moderate or low degrees of association, with OR ranging from 0.88 to 1.23. Taking together, these genes may account only for a fraction of the attributable AD risk and therefore, rare variants and epistastic gene interactions should be taken into account in order to get the full picture of the genetic risks associated with AD. Here, we review recent whole-exome studies looking for rare variants, somatic brain mutations with a strong association to the disease, and several studies dealing with epistasis as additional mechanisms conferring genetic susceptibility to AD. Altogether, recent evidence underlines the importance of defining molecular and genetic pathways, and networks rather than the contribution of specific genes.
Alzheimer; epistasis; exome; GWAS; neurodegeneration; rare variants; risk factors; somatic mutations
Owing to the need of lifelong immunosuppression, solid-organ transplant recipients are known to have an increased risk of posttransplant malignancies including lung cancer. Posttransplant neoplastic transformation of donor-derived cells giving rise to hematopoietic malignancies, Kaposi sarcoma, and basal cell carcinoma in nongraft tissues has been reported. The goal of this study was to assess the cell origin (donor versus recipient derived) of posttransplant non–small cell lung carcinomas (NSCLCs) in kidney and heart transplant recipients. An institutional database search identified 2557 kidney and heart transplant recipients in 8 consecutive years. Among this cohort, 20 (0.8%) renal and 18 (0.7%) heart transplant recipients developed NSCLC. The study cohort comprised 6 of 38 NSCLCs arising in donor-recipient sex-mismatched transplant patients. The tumor cell origin was evaluated by chromogenic in situ hybridization with Y-chromosome probe on formalin-fixed, paraffin-embedded tissues. Y-chromosome was identified in 97% ± 1% (range from 92% to 99%) of all types of nucleated cells in male control tissues. In all 5 NSCLCs from male recipients of female donor organ, Y-chromosome was identified in 97% ± 2% (range from 92% to 100%) of tumor cells, statistically equivalent to normal control (P < .001). No Y-chromosome was identified in NSCLC cells from a female recipient of male kidney. These findings suggest a recipient derivation of NSCLC arising in kidney and heart transplant recipients. A combination of histologic evaluation and chromogenic in situ hybridization with Y-chromosome analysis allows reliable determination of tissue origin in sex-mismatched solid-organ transplant recipients and may aid in management of posttransplant malignancy in such cases.
Post–solid-organ transplantation lung cancer; Chromogenic in situ hybridization for Y-chromosome
The Shoc2 protein has been implicated in the positive regulation of the Ras-ERK pathway by increasing the functional binding interaction between Ras and Raf, leading to increased ERK activity. Here we found that Shoc2 overexpression induced sustained ERK phosphorylation, notably in the case of EGF stimulation, and Shoc2 knockdown inhibited ERK activation. We demonstrate that ectopic overexpression of human Shoc2 in PC12 cells significantly promotes neurite extension in the presence of EGF, a stimulus that induces proliferation rather than differentiation in these cells. Finally, Shoc2 depletion reduces both NGF-induced neurite outgrowth and ERK activation in PC12 cells. Our data indicate that Shoc2 is essential to modulate the Ras-ERK signaling outcome in cell differentiation processes involved in neurite outgrowth.
Mitomycin C (MMC) produces significant upregulation of thymidine phosphorylase, a principal determinant of the therapeutic index of capecitabine-based treatment, starting 4–6 days after treatment. On the basis of the time-dependency of this upregulation, we performed a phase I dose escalation study of capecitabine and MMC in patients with gastrointestinal malignancies.
A total of 29 patients with advanced gastrointestinal malignancies received MMC at 6 mg/m2 on day 1 and capecitabine escalated in four successive patient cohorts of doses 500–1,000 mg/m2/day twice daily on days 8–21, every 28 days. MMC was capped at 36 mg/m2.
A total of 29 patients were enrolled and 90% had at least one prior treatment in the metastatic setting. There was one DLT, grade 3 hand and foot syndrome, at dose level four. The most common toxicity was fatigue (61%). No patients experienced grade 4 toxicities. Nine patients experienced prolonged stability of disease.
Capecitabine in combination with MMC in the proposed schedule is well-tolerated with evidence of preliminary activity. The recommended dose for phase II studies are MMC at 6 mg/m2 on day 1 of a 28-day cycle with the dose capped at 36 mg/m2, in combination with capecitabine at 1,000 mg/m2 twice daily on days 8–21.
Capecitabine; Mitomycin C; Gastrointestinal malignancies
We have shown the feasibility of administering inhaled doxorubicin to patients with cancer. This study evaluated inhaled doxorubicin combined with cisplatin and docetaxel in patients with non–small cell lung cancer. The principal objective was to determine safety and, secondarily, efficacy.
Patients who had chemo-naïve advanced non–small cell lung cancer were enrolled in the study. Adequate organ and pulmonary function was required: diffusing capacity for carbon monoxide/forced expiratory volume in 1 second/forced vital capacity ≥50%, resting/exercise O2 saturation ≥90%/85%. In phase I, doxorubicin was escalated: dose level 1 (6 mg/m2) and level 2 (7.5 mg/m2). Escalation was permitted if ≤2 of 6 patients experienced pulmonary dose-limiting toxicity (grade 2 Radiation Therapy Oncology Group lung morbidity; resting O2 saturation of <85%; decrease in diffusing capacity for carbon monoxide, forced vital capacity, or forced expiratory volume in 1 second of ≥20% from baseline or ≤30% of predicted; or grade 3 Common Terminology Criteria for Adverse Events version 3.0 pulmonary toxicity). Doses of cisplatin and docetaxel were 75 mg/m2. Treatments and pulmonary function tests were repeated every 21 days, with up to eight cycles for responding patients.
Twenty-eight patients were treated at level 1 and eight patients at level 2. Doxorubicin was escalated to 7.5 mg/m2, however, after two patients developed pulmonary dose-limiting toxicity; the remainder were treated at 6.0 mg/m2. Twenty-four evaluable patients received at least two courses or had progressive disease following the first course at the phase II dose. Toxicity was associated with i.v. chemotherapy although one patient had delayed pulmonary toxicity responding to corticosteroids and oxygen. Seven (29%) evaluable patients responded (six partial responses and one complete response) and 13 (54%) patients had stable disease for up to eight cycles.
Although this combination was safe, the primary objective was not met and will not be pursued further.
Sporadic Creutzfeldt-Jakob disease (sCJD) might be transmitted by surgery. The purpose of this study was to investigate potential susceptibility to sCJD from surgery at juvenile age and in early adulthood.
From Danish and Swedish national registries we identified 167 definite and probable sCJD cases with onset from 1987 through 2003, and 835 age-, sex- and residence-matched controls along with their surgical histories. Main, anatomically or etiologically classified surgical procedures followed by a ≥20-year lag were analyzed using logistic regression, and stratified by age at first-registered surgical discharge.
The risk of having a diagnosis of CJD depended strongly on age at first surgery with odds ratio (OR) of 12.80 (95% CI 2.56–64.0) in patients <30 years, 3.04 (95% 1.26–7.33) in 30–39 years, and 1.75 (95% CI 0.89–3.45) in ≥40 years, for anatomically classified surgical procedures. Similar figures were obtained for etiologically classified surgical procedures.
Risk of surgical-acquired sCJD depends on age at exposure; this pattern is similar to age-specific profiles reported for CJD accidentally transmitted by human pituitary-derived growth hormone and susceptibility curves for variant CJD estimated after adjustment for dietary exposure to bovine spongiform encephalopathy. There might be an age-at-exposure-related susceptibility to acquire all CJD forms, including sCJD from routine surgery.
Restoration of p53 function in tumor cells would be an attractive strategy for lung cancer therapy because p53 mutations are found in more than 50% of lung cancers. The small molecule PRIMA-1 has been shown to restore the tumor suppression function of p53 and to induce apoptosis in human tumor cells. The mechanism of apoptosis induced by PRIMA-1 remains unclear. We investigated the effects of PRIMA-1 in apoptosis with Western immunoblot analysis, TaqMan microRNA real-time PCR, cell viability analysis and flow cytometry using human lung cancer cell lines containing mutant (H211 and H1155), wild-type (A549) or null (H1299) p53. PRIMA-1 induced massive apoptosis in the H211 and H1155 cells, but was less toxic to the A549 and H1299 cells. Western immunoblot analysis showed cleavage of PARP in H211 and H1155 cells but not in A549 and H1299 cells following treatment with PRIMA-1. In addition, p53 protein was also phosphorylated in H211 and H1155 cells. TaqMan microRNA assay showed that the expression of microRNA-34a was increased in the H211 and H1155 cells posttreatment. Knockdown microRNA-34a decreased the rate of apoptosis caused by PRIMA-1. The above results suggest that microRNA-34a is one of the important components of PRIMA-1-induced apoptotic network in the cancer cells harboring mutant p53.
microRNA-34; PRIMA-1; apoptosis; lung cancer
Lung cancer (LC) and colorectal cancer (CRC) are the first and second deadliest types of cancer worldwide. EGFR-based therapy has been used in the treatment of these cancers with variable success. Presence of mutations in the KRAS driver oncogene, possibly induced by environmental factors such as carcinogens in diet and cigarette smoke, may confer worse prognosis and resistance to treatment for reasons not fully understood. Data on possible associations between KRAS mutational status and clinical and metabolic parameters, which may help in clinical management, as well as in identifying risk factors for developing these cancers, are limited in the current literature. We sequenced the KRAS gene and investigated the associations of variations in 108 patients with non-small cell lung carcinoma (NSCLC), the most common form of LC, and in 116 patients with CRC. All of the mutations originated from the guanosine nucleotide and over half of all transversions in NSCLC and CRC were c.34 G>T and c.35 G>T, respectively. c.35 G>A was the most frequent type of transition in both cancers. Excluding smoking, the clinical and metabolic parameters in patients carrying mutant and wild type KRAS were similar except that the CRC patients with transversion mutations were 8.6 years younger than those carrying the transitions (P < 0.01). Dyslipidemia, hypertension, family cancer history, and age of diagnosis older than 60 years were more frequent in NSCLC than CRC (P ≤ 0.04). These results suggest that most of the clinical and metabolic parameters investigated in this study are probably not associated with the more aggressive phenotype and differences in response to EGFR-based treatment previously reported in patients with KRAS mutations. However, the increased rates of abnormal metabolic parameters in patients with NSCLC in comparison to CRC indicate that these parameters may be more important in the management of NSCLC. CRC patients carrying transition mutations are older than those carrying transversions, suggesting that age may determine the type of KRAS mutation in CRC patients.
KRAS; non-small cell lung carcinoma; colorectal cancer; transition; transversion
Cigarette smoking is one of the most significant public health issues and the most common environmental cause of preventable cancer deaths worldwide. EGFR (Epidermal Growth Factor Receptor)-targeted therapy has been used in the treatment of LC (lung cancer), mainly caused by the carcinogens in cigarette smoke, with variable success. Presence of mutations in the KRAS (Kirsten rat sarcoma viral oncogene homolog) driver oncogene may confer worse prognosis and resistance to treatment for reasons not fully understood. NQO1 (NAD(P)H:quinone oxidoreductase), also known as DT-diaphorase, is a major regulator of oxidative stress and activator of mitomycins, compounds that have been targeted in over 600 pre-clinical trials for treatment of LC. We sequenced KRAS and investigated expression of NQO1 and five clinically relevant proteins (DNMT1, DNMT3a, ERK1/2, c-MET, and survivin) in 108 patients with non-small cell lung carcinoma (NSCLC). NQO1, ERK1/2, DNMT1, and DNMT3a but not c-MET and survivin expression was significantly more frequent in patients with KRAS mutations than those without, suggesting the following: (1) oxidative stress may play an important role in the pathogenesis, worse prognosis, and resistance to treatment reported in NSCLC patients with KRAS mutations, (2) selecting patients based on their KRAS mutational status for future clinical trials may increase success rate, and (3) since oxidation of nucleotides also specifically induces transversion mutations, the high rate of KRAS transversions in lung cancer patients may partly be due to the increased oxidative stress in addition to the known carcinogens in cigarette smoke.
lung cancer; non-small cell lung carcinoma; oxidative stress; KRAS; mutation; NQO1; DNA methyl transferase; ERK1/2; c-MET; survivin
The emergence of novel drugs corresponds with the determination of the effectiveness of the current treatments used in clinical practice. A retrospective observational study was conducted to evaluate the effectiveness of first-line treatments and to test the influence of the prognostic factors established using the Memorial Sloan-Kettering Cancer Center (MSKCC) and the analysis of Mekhail’s study for two or more metastatic sites. The primary endpoints were median progression-free survival (mPFS) and median overall survival (mOS) times. A total of 65 patients were enrolled and the mPFS and mOS of the patients treated with sunitinib (n=51) were 9.0 and 20.1 months, respectively, and for the patients treated with temsirolimus (n=14) these were 3.0 and 6.2 months, respectively. In the poor-prognosis (PP) group, a difference of 1.2 months (P=0.049) was found in mPFS depending on the first-line treatment. A difference of 4.1 months (P=0.023) was also found in mPFS when classified by histology (clear verses non-clear cell) in the sunitinib-treatment group. When stratified by the prognostic group, differences of >7 months (P<0.001) were found between the groups. Therefore, it was concluded that the effectiveness of the treatments was reduced compared to previous studies and differences were found in the PP group when classified by first-line drug and histology. Additionally, the influence of prognostic factors on OS and the value of stratifying patients using these factors have been confirmed.
renal cell cancer; effectiveness; sunitinib; temsirolimus; prognosis
A major mechanism of DNA repair related to homologous recombination is the Fanconi Anemia pathway (FA). FA genes collaborate with BRCA genes to form foci of DNA repair on chromatin following DNA damage, or during S phase of the cell cycle. Our goal was to develop a method capable of evaluating the functional status of the pathway in patients’ tumor tissue, which could also be practically incorporated to large scale screening. In order to develop this method, we first used Western immunoblot to detect FANCD2 protein mono-ubiquitination in fresh tumor specimens of ovarian cancer patients undergoing surgery, and stained formalin fixed paraffin embedded (FFPE) tumor tissue simultaneously with DAPI, FANCD2 and Ki67 antibodies, eventually extending this method to other solid tumors. This triple stain permitted evaluation of the presence, or lack thereof, of FANCD2 subnuclear repair foci in proliferating cells by immunofluorescence microscopy. Overall, we evaluated 156 FFPE tumor samples using the FA triple staining immunofluorescence (FATSI) method. The ratios of FANCD2 foci negative tumors in ovarian, lung, and breast tumor samples were 21%, 20%, and 29.4%, respectively. Our studies have led to the development of a suitable method for screening, capable of identifying tumors with somatic functional defects in the FA pathway. The use of paraffin embedded tissues renders the reported method suitable for large scale screening to select patients for treatment with DNA interstrand crosslinking agents, PARP inhibitors or their combination.
patient selection; DNA repair foci
Targeted cancer therapies often induce “outlier” responses in molecularly defined patient subsets. One patient with advanced-stage lung adenocarcinoma, who was treated with oral sorafenib, demonstrated a near-complete clinical and radiographic remission for 5 years. Whole-genome sequencing and RNA sequencing of primary tumor and normal samples from this patient identified a somatic mutation, ARAF S214C, present in the cancer genome and expressed at high levels. Additional mutations affecting this residue of ARAF and a nearby residue in the related kinase RAF1 were demonstrated across 1% of an independent cohort of lung adenocarcinoma cases. The ARAF mutations were shown to transform immortalized human airway epithelial cells in a sorafenib-sensitive manner. These results suggest that mutant ARAF is an oncogenic driver in lung adenocarcinoma and an indicator of sorafenib response.
Between 2005 and 2008, we conducted separate phase II clinical testing of 3 distinct anti-VEGF therapies for patients with relapsed/refractory CLL. Collectively, 46 patients were accrued to trials of single-agent anti-VEGF antibody (bevacizumab, n=13) or 1 of 2 receptor tyrosine kinase inhibitors (AZD2171, n=15; sunitinib malate, n=18). All patients have completed treatment. Patients received a median of 2 cycles of bevacizumab, AZD2171, or sunitinib malate. All 3 trials were closed early due to lack of efficacy. No complete or partial remissions were observed. Individually and collectively, these studies indicate single-agent anti-VEGF therapy has minimal clinical activity for patients with relapsed/refractory CLL.
chronic lymphocytic leukemia; angiogenesis; vascular endothelial growth factor (VEGF); therapy; bevacizumab; receptor tyrosine kinase inhibitor
A combinatorial library of 6 × 106 cyclic peptides was synthesized in the one bead-two compound format, with each bead displaying a unique cyclic peptide on its surface and a linear peptide encoding tag in its interior. Screening of the library against K-Ras identified compounds that bound K-Ras with submicromolar affinity and disrupted its interaction with effector proteins.
This phase II single-arm trial of docetaxel and capecitabine in previously untreated non-small cell lung cancer (NSCLC) patients was designed to evaluate response rate of this regimen based on promising efficacy data from phase II testing in pre-treated NSCLC patients. The trial also evaluated the correlation between peripheral blood dihydropyrimidine dehydrogenase (DPD) expression and efficacy/toxicity.
Patients with advanced NSCLC (metastatic, including malignant pleural effusion) without prior chemotherapy were enrolled. Baseline DPD screening was performed; patients with baseline DPD level < 0.07 nmol/min/mg protein were considered ineligible for the study. Treatment included a 28-day cycle of docetaxel 36 mg/m2 days 1, 8, 15 and capecitabine 1250 mg/m2/day in divided doses on days 5–18. Overall response rate (RR) was the primary endpoint with a target RR of 50%. Correlative studies included evaluation of DPD activity levels in peripheral blood and correlation with clinical responses.
Twenty-eight patients received 86 cycles of treatment (median 3 cycles) and were evaluable for response. The RR was 18% (5 patients); RR did not meet the pre-specified efficacy endpoint and the trial was stopped. 14 patients had stable disease (SD - 50%) and 4 pts had SD > 12 weeks. Median time to progression was 3.3 months (95% CI 1.5 – 4.6 months). Median overall survival was 10.5 months (95% CI: 3.2 – 15 months). Main toxicities included fatigue, stomatitis and leukopenia. DPD levels ranged from 0.06 to 0.26 nmol/min/mg. The majority of responders (4/5) had DPD levels ≤ 0.1 nmol/min/mg. Most of the responders (4/5) experienced grade 3 toxicities including leukopenia, dehydration, fatigue, and diarrhea. None of the patients (0/4) with higher DPD levels (>0.2 nmol/min/mg) had a response.
The response rate for the regimen did not demonstrate sufficient activity and further study of this regimen in this setting is not indicated. Interestingly, the results suggest that low DPD expression may be associated with response to capecitabine but also with increased toxicity.
non-small cell lung cancer; dihydropyrimidine deficiency; capecitabine
The Fanconi anemia (FA) pathway is a major mechanism of homologous recombination DNA repair. The functional readout of the pathway is activation through mono-ubiquitination of FANCD2 leading to nuclear foci of repair. We have recently developed an FA triple-staining immunofluorescence based method (FATSI) to evaluate FANCD2 foci formation in formalin fixed paraffin-embedded (FFPE) tumor samples. DNA-repair deficiencies have been considered of interest in lung cancer prevention, given the persistence of damage produced by cigarette smoke in this setting, as well as in treatment, given potential increased efficacy of DNA-damaging drugs. We screened 139 non-small cell lung cancer (NSCLC) FFPE tumors for FANCD2 foci formation by FATSI analysis. Among 104 evaluable tumors, 23 (22%) were FANCD2 foci negative, thus repair deficient. To evaluate and compare novel-targeted agents in the background of FA deficiency, we utilized RNAi technology to render several lung cancer cell lines FANCD2 deficient. Successful FANCD2 knockdown was confirmed by reduction in the FANCD2 protein. Subsequently, we treated the FA defective H1299D2-down and A549D2-down NSCLC cells and their FA competent counterparts (empty vector controls) with the PARP inhibitors veliparib (ABT-888) (5 μM) and BMN673 (0.5 μM), as well as the CHK1 inhibitor Arry-575 at a dose of 0.5 μM. We also treated the FA defective small cell lung cancer cell lines H719D2-down and H792D2-down and their controls with the BCL-2/XL inhibitor ABT-263 at a dose of 2 μM. The treated cells were harvested at 24, 48, and 72 h post treatment. MTT cell viability analysis showed that each agent was more cytotoxic to the FANCD2 knock-down cells. In all tests, the FA defective lung cancer cells had less viable cells as comparing to controls 72 h post treatment. Both MTT and clonogenic analyses comparing the two PARP inhibitors, showed that BMN673 was more potent compared to veliparib. Given that FA pathway plays essential roles in response to DNA damage, our results suggest that a subset of lung cancer patients are likely to be more susceptible to DNA cross-link based therapy, or to treatments in which additional repair mechanisms are targeted. These subjects can be identified through FATSI analysis. Clinical trials to evaluate this therapeutic concept are needed.
lung cancer; Fanconi anemia; pathway dysfunction; therapeutic target; FATSI
First-in-man study of KOS-1584, a second generation epothilone.
Patients with advanced solid malignancies received KOS-1584 every 3
weeks until disease progression. Using a modified Fibonacci dose escalation
scheme, one patient was enrolled at each dose level until the first instance
of grade 2 toxicity. Thereafter, a standard 3 + 3 design was
Sixty-six patients in 14 cohorts were dosed from 0.8 to 48
mg/m2. Diarrhea, arthralgias, and encephalopathy were
dose-limiting toxicities (DLTs) at doses ≥36 mg/m2. At
the recommended phase II dose (RP2D), the most common adverse effects were
peripheral neuropathy (low grade), fatigue, arthralgias/myalgias, and
diarrhea (31, 6%). The incidence of neutropenia was low. The overall
clearance, volume of distribution, and half-life of KOS-1584 were 11
± 6.17 L/h/m2, 327 ± 161 L/m2, and
21.9 ± 8.75 h, respectively. The half-life for the seco-metabolite
(KOS-1891) was 29.6 ± 13.8 h. KOS-1584 exhibited linear
pharmacokinetics. A dose-dependent increase in microtubulin bundle formation
was observed at doses ≥27 mg/m2. Two patients achieved
partial responses and 24 patients had stable disease (SD).
The RP2D of KOS-1584 is 36 mg/m2. The lack of severe
neurologic toxicity, diarrhea, neutropenia, or hypersensitivity reactions;
favorable pharmacokinetic profile; and early evidence of activity support
Epothilone; KOS-1584; Phase I; Solid tumors
Protein arginine methyltransferase-5 (PRMT5) is a chromatin-modifying enzyme capable of methylating histone and non-histone proteins, and is involved in a wide range of cellular processes that range from transcriptional regulation to organelle biosynthesis. As such, its overexpression has been linked to tumor suppressor gene silencing, enhanced tumor cell growth and survival.
Material and methods
Quantitative real-time polymerase chain reaction, Western immunoblot and immunohistochemistry were used to characterize PRMT5 expression in lung cancer cell lines and human tumors. Clinicopathological findings of tissue microarray based samples from 229 patients with non-small cell lung carcinomas (NSCLC) and 133 cases with pulmonary neuroendocrine tumors (NET) were analyzed with regard to nuclear and cytoplasmic PRMT5 expression.
There was statistically significant difference in PRMT5 messenger RNA expression between tumors and nonneoplastic lung tissues. Immunoblot experiments showed abundant expression of PRMT5 and its symmetric methylation mark H4R3 in lung carcinoma but not in non-neoplastic human pulmonary alveolar and bronchial epithelial cell lines. More than two thirds of lung tumors expressed PRMT5. High levels of cytoplasmic PRMT5 were detected in 20.5% of NSCLC and in 16.5% of NET; high levels of nuclear PRMT5 were detected in 38.0% of NSCLC and 24.0% of NET. Cytoplasmic PRMT5 was associated with high grade in both NSCLC and pulmonary NET while nuclear PRMT5 was more frequent in carcinoid tumors (p < 0.05).
The observed findings support the role of PRMT5 in lung tumorigenesis and reflect its functional dichotomy in cellular compartments.
The virtual slides for this article can be found here:
Protein arginine methyltransferase-5; Lung carcinoma; Neuroendocrine tumors