Prognostic and predictive significance of nuclear HIF1α expression in locally advanced HNSCC patients treated with chemoradiation with or without nimotuzumab

Background Anti-EGFR-based therapies have limited success in HNSCC patients. Predictive biomarkers are greatly needed to identify the patients likely to be benefited from these targeted therapies. Here, we present the prognostic and predictive association of biomarkers in HPV-negative locally advanced (LA) HNSCC patients.Methods Treatment-naive tumour tissue samples of 404 patients, a subset of randomised Phase 3 trial comparing cisplatin radiation (CRT) versus nimotuzumab plus cisplatin radiation (NCRT) were analysed to evaluate the expression of HIF1α, EGFR and pEGFR by immunohistochemistry and EGFR gene copy change by FISH. Progression-free survival (PFS), locoregional control (LRC) and overall survival (OS) were estimated by Kaplan–Meier method. Hazard ratios were estimated by Cox proportional hazard models.Results Baseline characteristics of the patients were balanced between two treatment groups (CRT vs NCRT) and were representative of the trial cohort. The median follow-up was of 39.13 months. Low HIF1α was associated with better PFS [HR (95% CI) = 0.62 (0.42–0.93)], LRC [HR (95% CI) = 0.56 (0.37–0.86)] and OS [HR (95% CI) = 0.63 (0.43–0.93)] in the CRT group. Multivariable analysis revealed HIF1α as an independent negative prognostic biomarker. For patients with high HIF1α, NCRT significantly improved the outcomes [PFS:HR (95% CI) = 0.55 (0.37–0.82), LRC:HR (95% CI) = 0.55 (0.36–0.85) and OS:HR (95% CI) = 0.54 (0.36–0.81)] compared to CRT. While in patients with low HIF1α, no difference in the clinical outcomes was observed between treatments. Interaction test suggested a predictive value of HIF1α for OS (P = 0.008).Conclusions High HIF1α expression is a predictor of poor clinical response to CRT in HPV-negative LA-HNSCC patients. These patients with high HIF1α significantly benefited with the addition of nimotuzumab to CRT.Clinical trial registration Registered with the Clinical Trial Registry of India (Trial registration identifier—CTRI/2014/09/004980).Subject terms: Tumour biomarkers, Head and neck cancer, Tumour biomarkers, Head and neck cancer, Predictive markers     

PAHs and PM2.5 emissions and female breast cancer incidence in metro Atlanta and rural Georgia

Environmental chemical exposure could be an important etiologic factor for geographic differences in breast cancer incidence. In this study, we examined emissions of polycyclic aromatic hydrocarbons (PAHs) and PM_2.5 in relation to breast cancer incidence in metro Atlanta and rural Georgia by analyzing data from the Surveillance, Epidemiology, and End Results Program and the Environmental Protection Agency. The results showed that metro Atlanta had a significantly higher age-adjusted annual incidence rate of female breast cancer than rural Georgia (132.6 vs. 113.7 per 100,000) for 1992–2011. Emissions of both PAHs [adjusted β = 0.568 (95 % CI: 0.209, 0.927); p = 0.004] and PM_2.5 [adjusted β = 2.964 (95 % CI: 0.468, 5.459); p = 0.023] were significantly associated with breast cancer incidence in metro Atlanta area. This study suggests that ambient air pollution, especially PAHs and PM_2.5, could have a significant impact on the increased incidence of female breast cancer in urban areas.     

Factors affecting compliance to intravitreal anti-vascular endothelial growth factor therapy in Indian patients with retinal vein occlusion,age-related macular degeneration,and diabetic macular edema

Purpose:To evaluate the rate of compliance and the reasons for loss to follow-up in Indian patients with diabetic macular edema (DME), age-related macular degeneration (AMD), and retinal vein occlusion (RVO) being treated with anti-vascular endothelial growth factor (VEGF) therapy.Methods:This was a retrospective single-center study. Patients with DME, AMD, or RVO were eligible if they initiated anti-VEGF therapy between January 2013 and December 2017. Patients'' data were obtained from hospital electronic records, including the number of injections received, visits, details of follow-up, missed appointments, and reasons for loss to follow-up (>365 days).Results:A total of 648 patients were eligible for the study, of which 334 (51.54%) patients were lost to follow-up. Overall, 343 (64.96%) were males and the overall mean (SD) age was 66.40 (7.44) years. A total of 376 (58.0%) patients had a history of diabetes and 364 (56.2%) patients had a history of hypertension. Further, 127 (38.0), 112 (33.5), and 95 (28.4) had DME, AMD, and RVO, respectively and were lost to follow-up. The most commonly reported reason for loss to follow-up was “non-affordability” (n = 120; 41.1%) followed by “no improvement in vision” (n = 83; 28.4%). “No improvement in vision” (42.2%) and “non-affordability” (37.5%) were higher among patients with DME. No association was found in gender- and treatment-wise distribution of reasons for loss to follow-up.Conclusion:The results showed that around half of the patients with DME, AMD, and RVO were lost to follow-up to intravitreal anti-VEGF therapy, and the most common factors were “non-affordability” and “no improvement in vision.”     

Drug discovery strategies for acute radiation syndrome

Introduction: There are at the minimum two major, quite different approaches to advance drug discovery. The first being the target-based drug discovery (TBDD) approach that is commonly referred to as the molecular approach. The second approach is the phenotype-based drug discovery (PBDD), also known as physiology-based drug discovery or empirical approach.

Area covered: The authors discuss, herein, the need for developing radiation countermeasure agents for various sub-syndromes of acute radiation syndromes (ARS) following TBDD and PBDD approaches. With time and continuous advances in radiation countermeasure drug development research, the expectation is to have multiple radiation countermeasure agents for each sub-syndrome made available to radiation exposed victims.

Expert opinion: The majority of the countermeasures currently being developed for ARS employ the PBDD approach, while the TBDD approach is clearly under-utilized. In the future, an improved drug development strategy might be a ‘hybrid’ strategy that is more reliant on TBDD for the initial drug discovery via large-scale screening of potential candidate agents, while utilizing PBDD for secondary screening of those candidates, followed by tertiary analytics phase in order to pinpoint efficacious candidates that target the specific sub-syndromes of ARS.     

PET imaging of the dopamine transporter with 18F-FECNT: a polar radiometabolite confounds brain radioligand measurements.

18F-2beta-Carbomethoxy-3beta-(4-chlorophenyl)-8-(2-fluoroethyl)nortropane (18F-FECNT), a PET radioligand for the dopamine transporter (DAT), generates a radiometabolite that enters the rat brain. The aims of this study were to characterize this radiometabolite and to determine whether a similar phenomenon occurs in human and nonhuman primate brains by examining the stability of the apparent distribution volume in DAT-rich (striatum) and DAT-poor (cerebellum) regions of the brain. METHODS: Two rats were infused with 18F-FECNT and sacrificed at 60 min. Extracts of brain and plasma were analyzed by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometric (LC-MS) techniques. Two human participants and 3 rhesus monkeys were injected with 18F-FECNT and scanned kinetically, with serial arterial blood analysis. RESULTS: At 60 min after the injection of rats, 18F-FECNT accumulated to levels about 7 times higher in the striatum than in the cortex and cerebellum. The radiometabolite was distributed at equal concentrations in all brain regions. The LC-MS techniques identified N-dealkylated FECNT as a major metabolite in the rat brain, and reverse-phase HPLC detected an equivalent amount of radiometabolite eluting with the void volume. The radiometabolite likely was 18F-fluoroacetaldehyde, the product expected from the N-dealkylation of 18F-FECNT, or its oxidation product, 18F-fluoroacetic acid. The distribution volume in the cerebellum increased up to 1.7-fold in humans between 60 and 300 min after injection and 2.0 +/- 0.1-fold (mean +/- SD; n = 3) in nonhuman primates between 60 and 240 min after injection. CONCLUSION: An 18F-fluoroalkyl metabolite of 18F-FECNT originating in the periphery confounded the measurements of DAT in the rat brain with a reference tissue model. Its uniform distribution across brain regions suggests that it has negligible affinity for DAT (i.e., it is an inactive radiometabolite). Consistent with the rodent data, the apparent distribution volume in the cerebellum of both humans and nonhuman primates showed a continual increase at late times after injection, a result that may be attributed to entry of the radiometabolite into the brain. Thus, reference tissue modeling of 18F-FECNT will be prone to more errors than analysis with a measured arterial input function.     

Characterization of the CXCR4 Signaling in Pancreatic Cancer Cells

CXCL12 and its receptor, CXCR4, are emerging as promising targets for modulating growth, angiogenesis, and metastasis in several human cancers. Indeed, blocking the receptor is sufficient to prevent metastasis and angiogenesis in experimental breast cancer xenografts. Recently, the biological effect of the CXCR4 in pancreatic cancer, one of the most deadly neoplastic diseases, has been reported. However, the molecular mechanism by which CXCR4 contributes to these properties is not completely understood. In this paper, we characterize the signaling pathways activated by CXCR4 in pancreatic cancer. We show that after CXCR4 activation, EGFR becomes tyrosine phosphorylated, and the kinase activity of this receptor, together with the activation of MMPs, Src, and PI3-Kinase, is required for CXCR4-mediated ERK activation. Analysis of this cascade in pancreatic cancer cells revealed that the ERK-mediated pathway regulates genes involved in angiogenesis, such as VEGF, CD44, HIF1α, and IL-8. Furthermore, ERK blockage inhibits the migration and tube formation of endothelial cells induced by CXCL12. Considering that inhibitors for several components of this pathway, including CXCR4 itself, are at different stages of clinical trials, this study provides theoretical justification for the clinical testing of these drugs in pancreatic cancer, thus extending the list of potential targets for treating this dismal disease.