Phospho-ERK and AKT status, but not KRAS mutation status, are associated with outcomes in rectal cancer treated with chemoradiotherapy

<p>Abstract</p> <p>Background</p> <p><it>KRAS </it>mutations may predict poor response to radiotherapy. Downstream events from <it>KRAS</it>, such as activation of <it>BRAF</it>, AKT and ERK, may also confer prognostic information but have not been tested in rectal cancer (RC). Our objective was to explore the relationships of <it>KRAS </it>and <it>BRAF </it>mutation status with p-AKT and p-ERK and outcomes in RC.</p> <p>Methods</p> <p>Pre-radiotherapy RC tumor biopsies were evaluated. <it>KRAS </it>and <it>BRAF </it>mutations were assessed by pyrosequencing; p-AKT and p-ERK expression by immunohistochemistry.</p> <p>Results</p> <p>Of 70 patients, mean age was 58; 36% stage II, 56% stage III, and 9% stage IV. Responses to neoadjuvant chemoradiotherapy: 64% limited, 19% major, and 17% pathologic complete response. 64% were <it>KRAS </it>WT, 95% were <it>BRAF </it>WT. High p-ERK levels were associated with improved OS but not for p-AKT. High levels of p-AKT and p-ERK expression were associated with better responses. <it>KRAS </it>WT correlated with lower p-AKT expression but not p-ERK expression. No differences in OS, residual disease, or tumor downstaging were detected by <it>KRAS </it>status.</p> <p>Conclusions</p> <p><it>KRAS </it>mutation was not associated with lesser response to chemoradiotherapy or worse OS. High p-ERK expression was associated with better OS and response. Higher p-AKT expression was correlated with better response but not OS.</p

Impact Study: MK-0646 (Dalotuzumab), Insulin Growth Factor 1 Receptor Antibody Combined with Pemetrexed and Cisplatin in Stage IV Metastatic Non-squamous Lung Cancer.

BackgroundInsulin-like growth factor 1 receptor (IGF-1R) regulates cell growth, proliferation, and apoptosis. Adenocarcinoma and never-smokers have a higher expression of IGF-1R, which is associated with worse overall survival. Dalotuzumab-MK0646 (D) is a humanized monoclonal antibody that targets IGF-1R. Pemetrexed (P) has higher activity in non-squamous lung cancer (NSQL). We initiated a randomized phase II trial to test the combination of P and Cisplatin (C) ± D in NSQL.MethodsEligibility criteria were untreated NSQL stage IV, ECOG 0 or 1, measurable disease, adequate renal, hepatic and hematologic function, and no other intercurrent illness. P at 500 mg/m(2) and C at 75 mg/m(2) IV were given every 3 weeks. D was given at 10 mg/kg IV weekly on days 1, 8, and 15 of every 3-week cycle in the experimental group. The patients had a radiographic assessment after every two cycles and were treated for a maximum of six cycles if there was a response or stable disease. The primary objective of the study was to compare the clinical response rates of PC vs. PC + D.ResultsFrom 1/2009 to 2/2011, the study accrued 26 subjects: 16 male and 10 female, with a median age of 59; 14 were treated with PC and 12 were treated with PC + D. We observed two partial responses (PR), seven stable disease (SD), three progressive disease (PD), and two not evaluable (NE) in the PC arm. In comparison, for the PC + D arm, there were three PR, four SD, four PD, and one NE. The hematologic toxicity was similar in both groups. There was higher incidence of hyperglycemia in the experimental group; four cases with grade 3 and one case with grade 4.ConclusionPC + D had a similar response rate compared to PC, with a higher rate of hyperglycemia. Identification of responders using predictive markers would be key to continuing the study of D in NSQL.Trial registrationNCT00799240, clinicaltrials.gov

Neprilysin Null Mice Develop Exaggerated Pulmonary Vascular Remodeling in Response to Chronic Hypoxia

Neprilysin is a transmembrane metalloendopeptidase that degrades neuropeptides that are important for both growth and contraction. In addition to promoting carcinogenesis, decreased levels of neprilysin increases inflammation and neuroendocrine cell hyperplasia, which may predispose to vascular remodeling. Early pharmacological studies showed a decrease in chronic hypoxic pulmonary hypertension with neprilysin inhibition. We used a genetic approach to test the alternate hypothesis that neprilysin depletion increases chronic hypoxic pulmonary hypertension. Loss of neprilysin had no effect on baseline airway or alveolar wall architecture, vessel density, cardiac function, hematocrit, or other relevant peptidases. Only lung neuroendocrine cell hyperplasia and a subtle neuropeptide imbalance were found. After chronic hypoxia, neprilysin-null mice exhibited exaggerated pulmonary hypertension and striking increases in muscularization of distal vessels. Subtle thickening of proximal media/adventitia not typically seen in mice was also detected. In contrast, adaptive right ventricular hypertrophy was less than anticipated. Hypoxic wild-type pulmonary vessels displayed close temporal and spatial relationships between decreased neprilysin and increased cell growth. Smooth muscle cells from neprilysin-null pulmonary arteries had increased proliferation compared with controls, which was decreased by neprilysin replacement. These data suggest that neprilysin may be protective against chronic hypoxic pulmonary hypertension in the lung, at least in part by attenuating the growth of smooth muscle cells. Lung-targeted strategies to increase neprilysin levels could have therapeutic benefits in the treatment of this disorder