Predicting time to castration resistance in hormone sensitive prostate cancer by a personalization algorithm based on a mechanistic model integrating patient data.

BACKGROUND: Prostate cancer (PCa) is a leading cause of cancer death of men worldwide. In hormone-sensitive prostate cancer (HSPC), androgen deprivation therapy (ADT) is widely used, but an eventual failure on ADT heralds the passage to the castration-resistant prostate cancer (CRPC) stage. Because predicting time to failure on ADT would allow improved planning of personal treatment strategy, we aimed to develop a predictive personalization algorithm for ADT efficacy in HSPC patients. METHODS: A mathematical mechanistic model for HSPC progression and treatment was developed based on the underlying disease dynamics (represented by prostate-specific antigen; PSA) as affected by ADT. Following fine-tuning by a dataset of ADT-treated HSPC patients, the model was embedded in an algorithm, which predicts the patient's time to biochemical failure (BF) based on clinical metrics obtained before or early in-treatment. RESULTS: The mechanistic model, including a tumor growth law with a dynamic power and an elaborate ADT-resistance mechanism, successfully retrieved individual time-courses of PSA (R(2) = 0.783). Using the personal Gleason score (GS) and PSA at diagnosis, as well as PSA dynamics from 6 months after ADT onset, and given the full ADT regimen, the personalization algorithm accurately predicted the individual time to BF of ADT in 90% of patients in the retrospective cohort (R(2) = 0.98). CONCLUSIONS: The algorithm we have developed, predicting biochemical failure based on routine clinical tests, could be especially useful for patients destined for short-lived ADT responses and quick progression to CRPC. Prospective studies must validate the utility of the algorithm for clinical decision-making.

Role of AKT-glycogen synthase kinase axis in monocyte activation in human beings with and without type 2 diabetes.

Monocyte activation by chemokines is a vital trigger for initiation of atherosclerotic process. Circulating levels of platelet activating factor (PAF), a recognized chemokine, is known to be increased in type 2 diabetes that is linked to accelerated atherosclerosis. To explore the molecular basis we examined the signalling pathways involved in PAF induced monocyte activation. PAF increased migration in monocytes obtained from THP-1 cells, nondiabetic and diabetic subjects. This effect was blocked by AKT inhibition. It did so by phosphorylation of glycogen synthase kinase (GSK)-3betaS(9), which was completely blocked by AKT inhibition. Additionally, PAF induced GSK-3beta phosphorylation was linked to Rac-1 activation and Rho-A inactivation leading to migration. Paradoxically, inhibition of GSK-3beta phosphorylation also augmented monocyte migration in THP-1, ND and diabetic monocytes through phosphorylation of AKT and activation of Rho-A that was independent of GSK. This was validated when (i) overexpression of dominant negative mutants of Rho-A reversed GSK inhibitor induced monocyte migration and (ii) AKT inhibition blocked GSK inhibitor induced Rho-A activity. Constitutively active ARAP3 (Rho-GAP) appears to have a regulatory role in monocyte activity during GSK inhibition. Finally, inhibition of monocyte GSK-3beta activity (by inhibitors and genetic manipulation) led to enhanced migration in diabetes compared to persons without diabetes. We conclude that diabetic monocytes show increased migratory capacity in response to GSK-3beta inhibition. GSK inhibitors developed to treat the metabolic complications of diabetes should therefore be used with caution.

Whole blood defensin mRNA expression is a predictive biomarker of docetaxel response in castration-resistant prostate cancer.

This study tested the potential of circulating RNA-based signals as predictive biomarkers for docetaxel response in patients with metastatic castration-resistant prostate cancer (CRPC). RNA was analyzed in blood from six CRPC patients by whole-transcriptome sequencing (total RNA-sequencing) before and after docetaxel treatment using the Illumina's HiSeq platform. Targeted RNA capture and sequencing was performed in an independent cohort of ten patients with CRPC matching the discovery cohort to confirm differential expression of the genes. Response to docetaxel was defined on the basis of prostate-specific antigen levels and imaging criteria. Two-way analysis of variance was used to compare differential gene expression in patients classified as responders versus nonresponders before and after docetaxel treatment. Thirty-four genes with two-fold differentially expressed transcripts in responders versus nonresponders were selected from total RNA-sequencing for further validation. Targeted RNA capture and sequencing showed that 13/34 genes were differentially expressed in responders. Alpha defensin genes DEFA1, DEFA1B, and DEFA3 exhibited significantly higher expression in responder patients compared with nonresponder patients before administration of chemotherapy (fold change >2.5). In addition, post-docetaxel treatment significantly increased transcript levels of these defensin genes in responders (fold change >2.8). Our results reveal that patients with higher defensin RNA transcripts in blood respond well to docetaxel therapy. We suggest that monitoring DEFA1, DEFA1B, and DEFA3 RNA transcripts in blood prior to treatment will be helpful to determine which patients are better candidates to receive docetaxel chemotherapy.

Exosomal miR-1290 and miR-375 as prognostic markers in castration-resistant prostate cancer.

BACKGROUND: Extracellular microRNAs (miRNAs) embedded in circulating exosomes may serves as prognostic biomarkers in cancer. OBJECTIVE: To identify and evaluate plasma exosomal miRNAs for prognosis in castration-resistant prostate cancer (CRPC). DESIGN, SETTING, AND PARTICIPANTS: RNA sequencing was performed to identify candidate exosomal miRNAs associated with overall survival in a screening cohort of 23 CRPC patients. Candidate miRNAs were further evaluated for prognosis using quantitative real-time polymerase chain reaction in a follow-up cohort of 100 CRPC patients. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Cox regression and Kaplan-Meier survival analyses were used to evaluate survival association using candidate miRNAs along with clinical prognostic factors. RESULTS AND LIMITATIONS: RNA sequencing in screening cohort generated approximately 6.80 million mappable reads per patient. Of those with normalized read counts ≥ 5, 43% were mapped to miRNAs for a total of 375 known and 57 novel miRNAs. Cox regression analysis identified an association of miR-1290, -1246, and -375 with overall survival (false discover rate < 0.05). Of those, higher levels of miR-1290 and -375 were significantly associated with poor overall survival (p < 0.004) in the follow-up cohort. Incorporation of miR-1290/-375 into putative clinical prognostic factors-based models in CRPC stage significantly improved predictive performance with a time-dependent area under the curve increase from 0.66 to 0.73 (p = 6.57 × 10(-6)). CONCLUSIONS: Plasma exosomal miR-1290 and miR-375 are promising prognostic biomarkers for CRPC patients. Prospective validation is needed for further evaluation of these candidate miRNAs. PATIENT SUMMARY: In this study, we evaluated whether small RNAs circulating in blood could be used to predict clinical outcomes in late-stage prostate cancer patients. We identified two blood-based small RNAs whose levels showed significant association with survival. Our results warrant further investigation because the noninvasive blood-based test has great potential in the management of late-stage prostate cancer.

Plasma genetic and genomic abnormalities predict treatment response and clinical outcome in advanced prostate cancer.

Liquid biopsies, examinations of tumor components in body fluids, have shown promise for predicting clinical outcomes. To evaluate tumor-associated genomic and genetic variations in plasma cell-free DNA (cfDNA) and their associations with treatment response and overall survival, we applied whole genome and targeted sequencing to examine the plasma cfDNAs derived from 20 patients with advanced prostate cancer. Sequencing-based genomic abnormality analysis revealed locus-specific gains or losses that were common in prostate cancer, such as 8q gains, AR amplifications, PTEN losses and TMPRSS2-ERG fusions. To estimate tumor burden in cfDNA, we developed a Plasma Genomic Abnormality (PGA) score by summing the most significant copy number variations. Cox regression analysis showed that PGA scores were significantly associated with overall survival (p < 0.04). After androgen deprivation therapy or chemotherapy, targeted sequencing showed significant mutational profile changes in genes involved in androgen biosynthesis, AR activation, DNA repair, and chemotherapy resistance. These changes may reflect the dynamic evolution of heterozygous tumor populations in response to these treatments. These results strongly support the feasibility of using non-invasive liquid biopsies as potential tools to study biological mechanisms underlying therapy-specific resistance and to predict disease progression in advanced prostate cancer.

The effect of liraglutide on endothelial function in patients with type 2 diabetes.

This single-centre, 12-week, double-blind, placebo-controlled trial assessed how the human glucagon-like-peptide 1 analogue liraglutide impacted endothelial function in adult patients (n = 49) with type 2 diabetes and no overt cardiovascular disease. Patients were randomized to liraglutide, placebo or glimepiride. At baseline and Week 12, venous occlusion plethysmography was used to measure forearm blood flow (FBF) in response to acetylcholine (ACh) and sodium nitroprusside (SNP) before and after (L)-N(G)-monomethyl arginine (L-NMMA) infusion. At Week 12, ACh-mediated FBF increased with liraglutide and decreased with placebo; however, the between-treatment difference was not significant (p = 0.055). Inhibition of ACh-mediated FBF after L-NMMA infusion increased with liraglutide and decreased with placebo; this between-treatment difference was also not significant (p = 0.149). No change in FBF was observed with SNP. Liraglutide did not significantly impact endothelium-dependent vasodilation after 12 weeks; however, additional investigations looking at the effect of liraglutide on endothelial function in alternative vasculature and during the postprandial period are warranted.

Diurnal pattern of insulin action in type 1 diabetes: implications for a closed-loop system.

We recently demonstrated a diurnal pattern to insulin action (i.e., insulin sensitivity [SI]) in healthy individuals with higher SI at breakfast than at dinner. To determine whether such a pattern exists in type 1 diabetes, we studied 19 subjects with C-peptide-negative diabetes (HbA1c 7.1 ± 0.6%) on insulin pump therapy with normal gastric emptying. Identical mixed meals were ingested during breakfast, lunch, and dinner at 0700, 1300, and 1900 h in randomized Latin square of order on 3 consecutive days when measured daily physical activity was equal. The triple tracer technique enabled measurement of glucose fluxes. Insulin was administered according to the customary insulin:carbohydrate ratio for each participant. Although postprandial glucose excursions did not differ among meals, insulin concentration was higher (P < 0.01) and endogenous glucose production less suppressed (P < 0.049) at breakfast than at lunch. There were no differences in meal glucose appearance or in glucose disappearance between meals. Although there was no statistical difference (P = 0.34) in SI between meals in type 1 diabetic subjects, the diurnal pattern of SI taken across the three meals in its entirety differed (P = 0.016) from that of healthy subjects. Although the pattern in healthy subjects showed decreasing SI between breakfast and lunch, the reverse SI pattern was observed in type 1 diabetic subjects. The results suggest that in contrast to healthy subjects, SI diurnal pattern in type 1 diabetes is specific to the individual and cannot be extrapolated to the type 1 diabetic population as a whole, implying that artificial pancreas algorithms may need to be personalized.

The effect of walking on postprandial glycemic excursion in patients with type 1 diabetes and healthy people.

OBJECTIVE: Physical activity (PA), even at low intensity, promotes health and improves hyperglycemia. However, the effect of low-intensity PA captured with accelerometery on glucose variability in healthy individuals and patients with type 1 diabetes has not been examined. Quantifying the effects of PA on glycemic variability would improve artificial endocrine pancreas (AEP) algorithms. RESEARCH DESIGN AND METHODS: We studied 12 healthy control subjects (five males, 37.7 ± 13.7 years of age) and 12 patients with type 1 diabetes (five males, 37.4 ± 14.2 years of age) for 88 h. Participants performed PA approximating a threefold increase over their basal metabolic rate. PA was captured using a PA-monitoring system, and interstitial fluid glucose concentrations were captured with continuous glucose monitors. In random order, one meal per day was followed by inactivity, and the other meals were followed by walking. Glucose and PA data for a total of 216 meals were analyzed from 30 min prior to meal ingestion to 270 min postmeal. RESULTS: In healthy subjects, the incremental glucose area under the curve was 4.5 mmol/L/270 min for meals followed by walking, whereas it was 9.6 mmol/L/270 min (P = 0.022) for meals followed by inactivity. The corresponding glucose excursions for those with type 1 diabetes were 7.5 mmol/L/270 min and 18.4 mmol/L/270 min, respectively (P < 0.001). CONCLUSIONS: Walking significantly impacts postprandial glucose excursions in healthy populations and in those with type 1 diabetes. AEP algorithms incorporating PA may enhance tight glycemic control end points.

Diurnal pattern to insulin secretion and insulin action in healthy individuals.

Evaluation of the existence of a diurnal pattern of glucose tolerance after mixed meals is important to inform a closed-loop system of treatment for insulin requiring diabetes. We studied 20 healthy volunteers with normal fasting glucose (4.8 ± 0.1 mmol/L) and HbA(1c) (5.2 ± 0.0%) to determine such a pattern in nondiabetic individuals. Identical mixed meals were ingested during breakfast, lunch, or dinner at 0700, 1300, and 1900 h in randomized Latin square order on 3 consecutive days. Physical activity was the same on all days. Postprandial glucose turnover was measured using the triple tracer technique. Postprandial glucose excursion was significantly lower (P < 0.01) at breakfast than lunch and dinner. ß-Cell responsivity to glucose and disposition index was higher (P < 0.01) at breakfast than lunch and dinner. Hepatic insulin extraction was lower (P < 0.01) at breakfast than dinner. Although meal glucose appearance did not differ between meals, suppression of endogenous glucose production tended to be lower (P < 0.01) and insulin sensitivity tended to be higher (P < 0.01) at breakfast than at lunch or dinner. Our results suggest a diurnal pattern to glucose tolerance in healthy humans, and if present in type 1 diabetes, it will need to be incorporated into artificial pancreas systems.

Growth factor mediated signaling in pancreatic pathogenesis.

Functionally, the pancreas consists of two types of tissues: exocrine and endocrine. Exocrine pancreatic disorders mainly involve acute and chronic pancreatitis. Acute pancreatitis typically is benign, while chronic pancreatitis is considered a risk factor for developing pancreatic cancer. Pancreatic carcinoma is the fourth leading cause of cancer related deaths worldwide. Most pancreatic cancers develop in the exocrine tissues. Endocrine pancreatic tumors are more uncommon, and typically are less aggressive than exocrine tumors. However, the endocrine pancreatic disorder, diabetes, is a dominant cause of morbidity and mortality. Importantly, different growth factors and their receptors play critical roles in pancreatic pathogenesis. Hence, an improved understanding of how various growth factors affect pancreatitis and pancreatic carcinoma is necessary to determine appropriate treatment. This chapter describes the role of different growth factors such as vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), platelet derived growth factor (PDGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), and transforming growth factor (TGF) in various pancreatic pathophysiologies. Finally, the crosstalk between different growth factor axes and their respective signaling mechanisms, which are involved in pancreatitis and pancreatic carcinoma, are also discussed.

Effect of hyperglycemia on human monocyte activation.

Our recent study defined the chemokine-induced human monocyte signaling under normoglycemic condition. To explore the hyperglycemia-induced monocyte signaling, we performed adhesion, migration, and transmigration assays on human monocytes obtained from THP-1 cell line in the presence of normal (5 mM) and high (10 and 20 mM) glucose concentrations without chemokines. We observed augmented (P < 0.01) monocyte adhesion to human umbilical vein endothelial cell monolayer at 10 than 5 mM glucose with no further increase at 20-mM glucose concentration (P < 0.07 vs 10 mM; P < 0.01 vs 5 mM). But incremental increases in monocyte migration (P < 0.01), transmigration (P < 0.01), and stress fiber response (P < 0.01) were observed at 10- and 20-mM glucose concentrations in comparison to 5-mM glucose concentrations. We found gradational increase (P < 0.01) in phosphorylation of Akt(S473) and glycogen synthase kinase (GSK3ß(S9)) in hyperglycemia (10 and 20 mM) when compared with 5 mM glucose. Furthermore, hyperglycemia (both 10 and 20 mM)-treated monocyte showed up-regulated phosphorylation of p101 and p110γ subunits of PI-3 kinase in comparison to 5 mM glucose. Hyperglycemia-induced monocyte migration was restored to basal levels in the presence of PI-3 kinase inhibitor, LY. These observations imply that modest hyperglycemia per se, as is commonly observed in diabetic individuals, is a potent stimulator of monocyte activity even without chemokines.

Both vascular endothelial growth factor and soluble Flt-1 are increased in type 2 diabetes but not in impaired fasting glucose.

OBJECTIVE: Inadequate vascular remodeling is contributory to increased cardiovascular events in people with type 2 diabetes mellitus (DM) and impaired fasting glucose (IFG). Vascular endothelial growth factor (VEGF) and its regulatory molecule soluble Flt-1(sFlt-1) play important roles in atherogenesis. RESEARCH DESIGN: We measured fasting plasma concentrations of VEGF and sFlt-1 in 11 nondiabetic (ND) (aged 46.1 +/- 2.1 years; body mass index [BMI], 26.1 +/- 0.9 kg/m; glucose, 5.0 +/- 0.1 mM), 15 IFG (aged 52.9 +/- 1.8 years; BMI, 32.7 +/- 1.3 kg/m; glucose, 6.4 +/- 0.1 mM), and 8 DM (aged 55.8 +/- 3.2 years; BMI, 30.0 +/- 1.0 kg/m; glucose, 9.3 +/- 0.5 mM) subjects. RESULTS: Plasma VEGF (42.1 +/- 4.0 vs 24.2 +/- 0.9 vs 29.4 +/- 3.8 pg/mL, respectively) and sFlt-1 (119.4 +/- 4.9 vs 58.9 +/- 3.2 vs 56.7 +/- 1.2 pg/mL, respectively) concentrations were higher (P < 0.04) in DM than IFG and ND subjects. Whereas VEGF concentrations were significantly lower (P < 0.05) in IFG than in ND subjects, sFlt-1 concentrations did not differ between the IFG and ND subjects. CONCLUSIONS: Although plasma VEGF concentrations were higher (35%) in DM than in ND subjects, VEGF action on vascular remodeling was likely attenuated by higher sFlt-1 concentrations in DM. In contrast, IFG subjects did not have major perturbations in either VEGF or sFlt-1 levels. Further studies defining the roles of these mediators in DM and IFG are necessary to extend these observations.

RGS-GAIP-interacting protein controls breast cancer progression.

Although the importance of RGS-GAIP-interacting protein (GIPC) in the biology of malignant cells is well known, the molecular mechanism of GIPC in the inhibition of tumor progression has not been identified. This study focused on elucidating the molecular role of GIPC in breast cancer progression. By using a human breast tumor specimen, an in vivo mouse model, and breast cancer cell lines, we showed for the first time that GIPC is involved in breast cancer progression through regulation of breast cancer cell proliferation, survival, and invasion. Furthermore, we found that the Akt/Mdm2/p53 axis, insulin-like growth factor-1 receptor, matrix metalloproteinase-9, and Cdc42 were downstream of GIPC signaling in breast cancer cells. Moreover, we showed that wild-type p53 reduced GIPC-induced breast cancer cell survival, whereas mutant p53 inhibited GIPC-induced cell invasion. Finally, we demonstrated that an N-myristoylated GIPC peptide (CR1023, N-myristoyl-PSQSSSEA) capable of blocking the PDZ domain of GIPC successfully inhibited MDA-MB-231 cell proliferation, survival, and further in vivo tumor growth. Taken together, these findings demonstrate the importance of GIPC in breast tumor progression, which has a potentially significant impact on the development of therapies against many common cancers expressing GIPC, including breast and renal cancer.

Neuropilin-1 upholds dedifferentiation and propagation phenotypes of renal cell carcinoma cells by activating Akt and sonic hedgehog axes.

Expression of neuropilin-1 (NRP-1) has been shown in many cancer cells, but its molecular effect on tumorigenesis is largely unknown. In this report, we show that in aggressive types of renal cell carcinoma (RCC), NRP-1 is expressed at a high level. We show that after knockdown of NRP-1 by short hairpin RNA, RCC cells express significantly lower levels of MDM-2 and p63 proteins but higher levels of p53, and exhibit reduced migration and invasion. When implanted in mice, RCC cells with a reduced NRP-1 level have a statistically significant smaller tumor-forming ability than control cells. Also, NRP-1 knockdown RCC cells exhibit a more differentiated phenotype, as evidenced by the expression of epithelial-specific and kidney-specific cadherins, and the inhibition of sonic hedgehog expression participated in this effect. Inhibition of sonic hedgehog expression can be reversed by DeltaNp63alpha overexpression. Our study reveals that NRP-1 helps maintain an undifferentiated phenotype in cancer cells.

Lack of an effect of pioglitazone or glipizide on lipoprotein-associated phospholipase A2 in type 2 diabetes.

OBJECTIVE: To study the effects of pioglitazone, a peroxisome proliferator-activated receptor-y agonist with vascular beneficial effects, and glipizide, an insulin secretagogue, on novel inflammatory vascular risk markers in subjects with and without type 2 diabetes. METHODS: We studied 11 subjects without diabetes and 19 matched subjects with diabetes. The subjects with diabetes were randomly assigned to receive either 45 mg daily of pioglitazone (N = 8) or 10 mg daily of glipizide (N = 11) (median dose) for 12 weeks. Lipoprotein-associated phospholipase A2 (LpPLA2), vascular cell adhesion molecule (VCAM-1), intracellular adhesion molecule (ICAM-1), and e-selectin were measured by established techniques before and after therapy with either agent. The subjects without diabetes were studied only once. RESULTS: The study subjects with diabetes had higher (P<0.05) LpPLA2, e-selectin, and VCAM-1 levels than did those without diabetes. ICAM-1 levels tended to be higher (P = 0.07) in the study subjects with than in those without diabetes. Neither pioglitazone nor glipizide therapy significantly altered LpPLA2 or VCAM-1 concentrations. While pioglitazone therapy reduced (P<0.05) eselectin concentrations, glipizide therapy reduced (P<0.03) ICAM-1 concentrations. CONCLUSION: Type 2 diabetes is associated with elevated concentrations of the novel vascular risk marker LpPLA2 and inflammatory risk markers e-selectin and VCAM-1. Neither pioglitazone nor glipizide significantly altered LpPLA2, VCAM-1, or highly sensitive C-reactive protein levels after 12 weeks of therapy. In study subjects with type 2 diabetes, e-selectin concentrations declined significantly with pioglitazone therapy, whereas ICAM-1 concentrations decreased significantly with glipizide therapy.