Circulating cytokines and monocyte subpopulations as biomarkers of outcome and biological activity in sunitinib-treated patients with advanced neuroendocrine tumours

BACKGROUND

Sunitinib is approved worldwide for treatment of advanced pancreatic neuroendocrine tumours (pNET), but no validated markers exist to predict response. This analysis explored biomarkers associated with sunitinib activity and clinical benefit in patients with pNET and carcinoid tumours in a phase II study.

METHODS

Plasma was assessed for vascular endothelial growth factor (VEGF)-A, soluble VEGF receptor (sVEGFR)-2, sVEGFR-3, interleukin (IL)-8 (n=105), and stromal cell-derived factor (SDF)-1α (n=28). Pre-treatment levels were compared between tumour types and correlated with response, progression-free (PFS), and overall survival (OS). Changes in circulating myelomonocytic and endothelial cells were also analysed.

RESULTS

Stromal cell-derived factor-1α and sVEGFR-2 levels were higher in pNET than in carcinoid (P=0.003 and 0.041, respectively). High (above-median) baseline SDF-1α was associated with worse PFS, OS, and response in pNET, and high sVEGFR-2 with longer OS (P⩽0.05). For carcinoid, high IL-8, sVEGFR-3, and SDF-1α were associated with shorter PFS and OS, and high IL-8 and SDF-1α with worse response (P⩽0.05). Among circulating cell types, monocytes showed the largest on-treatment decrease, particularly CD14+ monocytes co-expressing VEGFR-1 or CXCR4.

CONCLUSIONS

Interleukin-8, sVEGFR-3, and SDF-1α were identified as predictors of sunitinib clinical outcome. Putative pro-tumorigenic CXCR4+ and VEGFR-1+ monocytes represent novel candidate markers and biologically relevant targets explaining the activity of sunitinib.

A cytokine and angiogenic factor (CAF) analysis in plasma for selection of sorafenib therapy in patients with metastatic renal cell carcinoma

BACKGROUND

We investigated cytokines and angiogenic factors (CAFs) in patients with metastatic renal cell carcinoma (mRCC) treated in a randomized phase II clinical trial of sorafenib versus sorafenib+ interferon-α (IFN-α) that yielded no differences in progression-free survival (PFS). We aimed to link the CAF profile to PFS and select candidate predictive and prognostic markers for further study.

METHODS

The concentrations of 52 plasma CAFs were measured pretreatment (n = 69), day 28, and day 56 using multiplex bead arrays and enzyme-linked immunosorbent assay. We investigated the association between baseline levels of CAFs with PFS and posttreatment changes.

RESULTS

Unsupervised CAF clustering analysis revealed two distinct mRCC patient groups with elevated proangiogenic or proinflammatory mediators. A six-marker baseline CAF signature [osteopontin, vascular endothelial growth factor (VEGF), carbonic anhydrase 9, collagen IV, VEGF receptor-2, and tumor necrosis factor-related apoptosis-inducing ligand] correlated with PFS benefit (hazard ratio 0.20 versus 2.25, signature negative versus positive, respectively; P = 0.0002). While changes in angiogenic factors were frequently attenuated by the sorafenib+ IFN combination, most key immunomodulatory mediators increased.

CONCLUSIONS

Using CAF profiling, we identified two mRCC patient groups, a candidate plasma signature for predicting PFS benefit, and distinct marker changes occurring with each treatment. This platform may provide valuable insights into renal cell carcinoma biology and the molecular consequences of targeted therapies.

Cytokine and angiogenic factor (CAF) profiling for identification of markers associated with response to cediranib in metastatic renal cell carcinoma (mRCC)

362

Background: Cediranib is a highly potent and selective signaling inhibitor of vascular endothelial growth factor (VEGF) receptors−1, −2, −3 and c-Kit. In a phase II trial, patients (pts) with mRCC were randomized 3:1 to treatment with cediranib or placebo to primarily assess the difference in change in tumor size at 12 weeks. Cediranib resulted in a significant reduction in tumor size vs. placebo (Mulders et al. ESMO. 2009). Here we investigated soluble biomarkers in serum and concentration changes during treatment.

Methods: Pts received cediranib 45 mg/day PO or placebo for the first 12 weeks on treatment. At that time (or upon progression if earlier), treatment was unblinded and pts on placebo were given the option of receiving cediranib. Serum was collected from 61 pts at baseline (BL; cediranib 46, placebo 15), from 50 pts on day (D) 28, and from 45 pts on D84. Multiplex bead suspension arrays and ELISA were used to measure CAF concentrations including VEGF, placental growth factor (PlGF), sVEGFR-2, PDGFbb, HGF, MMP-9, multiple chemokines and interleukins (IL). The objectives of this exploratory analysis were to assess whether baseline CAFs were associated with changes in tumor size after 12 weeks of treatment and whether CAF levels changed while on treatment.

Results: Of 39 CAFs available at BL, lower than median (‘low') concentrations of IL-10, VEGF, PlGF, stem cell factor (SCF), and monokine-induced by interferon-gamma (MIG) were associated with larger decreases in tumor size than high concentrations (independent of treatment arm), whereas the opposite trend was observed for IL-5 and TRAIL. Consistent with inhibition of VEGF signaling, cediranib treatment resulted in changes over time in VEGF (increase), sVEGFR-2 (decrease) and PlGF (increase) concentrations. In addition, SCF, a c-Kit ligand and M-CSF decreased, while VCAM-1 and TRAIL increased during cediranib treatment.

Conclusions: Candidate CAFs associated with response to cediranib in mRCC such as IL-10 and VEGF were identified. Patients treated with cediranib showed distinct CAF changes compared with placebo. These results require independent validation in a larger trial.

[Table: see text]

Dominant versus recessive traits conveyed by allelic mutations - to what extent is nonsense-mediated decay involved?

Mutations in ROR2, encoding a receptor tyrosine kinase, can cause autosomal recessive Robinow syndrome (RRS), a severe skeletal dysplasia with limb shortening, brachydactyly, and a dysmorphic facial appearance. Other mutations in ROR2 result in the autosomal dominant disease, brachydactyly type B (BDB1). No functional mechanisms have been delineated to effectively explain the association between mutations and different modes of inheritance causing different phenotypes. BDB1-causing mutations in ROR2 result from heterozygous premature termination codons (PTCs) in downstream exons and the conveyed phenotype segregates as an autosomal dominant trait, whereas heterozygous missense mutations and PTCs in upstream exons result in carrier status for RRS. Given that the distribution of PTC mutations revealed a correlation between the phenotype and the mode of inheritance conveyed, we investigated the potential role for the nonsense-mediated decay (NMD) pathway in the abrogation of possible aberrant effects of selected mutant alleles. Our experiments show that triggering or escaping NMD may cause different phenotypes with a distinct mode of inheritance. We generalize these findings to other disease-associated genes by examining PTC mutation distribution correlation with conveyed phenotype and inheritance patterns. Indeed, NMD may explain distinct phenotypes and different inheritance patterns conveyed by allelic truncating mutations enabling better genotype-phenotype correlations in several other disorders.

20p12.3 microdeletion predisposes to Wolff-Parkinson-White syndrome with variable neurocognitive deficits

BACKGROUND

Wolff-Parkinson-White syndrome (WPW) is a bypass re-entrant tachycardia that results from an abnormal connection between the atria and ventricles. Mutations in PRKAG2 have been described in patients with familial WPW syndrome and hypertrophic cardiomyopathy. Based on the role of bone morphogenetic protein (BMP) signalling in the development of annulus fibrosus in mice, it has been proposed that BMP signalling through the type 1a receptor and other downstream components may play a role in pre-excitation.

METHODS AND RESULTS

Using the array comparative genomic hybridisation (CGH), we identified five individuals with non-recurrent deletions of 20p12.3. Four of these individuals had WPW syndrome with variable dysmorphisms and neurocognitive delay. With the exception of one maternally inherited deletion, all occurred de novo, and the smallest of these harboured a single gene, BMP2. In two individuals with additional features of Alagille syndrome, deletion of both JAG1 and BMP2 were identified. Deletion of this region has not been described as a copy number variant in the Database of Genomic Variants and has not been identified in 13 321 individuals from other cohort examined by array CGH in our laboratory.

CONCLUSIONS

Our findings demonstrate a novel genomic disorder characterised by deletion of BMP2 with variable cognitive deficits and dysmorphic features and show that individuals bearing microdeletions in 20p12.3 often present with WPW syndrome.

Effect of feed restriction early in life on humoral and cellular immunity of two commercial broiler strains under heat stress conditions

1. An experiment was carried out to evaluate the effect of early feed restriction (FR) on immunocompetence of Ross and Arian chickens with separated sexes under heat stress (HS) conditions. 2. Chickens consumed feed ad libitum (AL) or were restricted on alternate days from 11 to 20 d of age. From 35 to 41 d of age, the HS groups were exposed to a high ambient temperature of 39 +/- 1 degreesC for 7 h each day, while the thermoneutral groups (TN) were at 33 degrees C. 3. At 21 and 42d of age, the percentage of CD4+ (helper T cells) and CD8+ (cytotoxic T cells) were determined by flow cytometry. Antibody response to sheep red blood cells (SRBC) and heterophil/lymphocyte (H/L) ratio were determined on d 21 and 42. 4. On d 21, FR elevated the CD4+, antibody titre and H/L ratio, but it decreased the CD8+ T cells. On d 42, HS decreased CD4+, CD8+, and antibody titre, but it increased H/L ratio. Under TN conditions, FR chickens had higher CD4+ than AL chickens. On d 42, FR/HS chickens had higher CD4+ and antibody titre, but they had lower CD8+ and H/L ratio than AL/HS chickens. 5. On d 42, the TN-Ross strain had lower CD4+, but they had higher CD8+ and antibody titres than the TN-Arian strain. On d 42, the HS-Arian strain had higher antibody titres and a lower H/L ratio than the HS-Ross strain. 6. Male chickens had higher CD4+, CD8+, antibody titres and H/L ratios 25 in all treatment groups. 7. In conclusion, FR early in life reduced some of the negative effects of the heat stress on the immune system of broiler chickens when exposed to high environmental temperatures later in life.

Alcohol dehydrogenase polymorphism and Parkinson's disease

A particular alcohol dehydrogenase (ADH) polymorphism (allele A1) in the promoter region of the gene has been recently demonstrated to be associated with increased risk of Parkinson's disease (PD). In a case control study, we examine frequencies of ADH A1 allele in 100 PD patients (i.e. 200 alleles), 100 diseased controls (i.e. 200 alleles), and 194 healthy controls (i.e. 388 alleles). In addition, we study possible association of a combined non-amyloid component of plaque (NACP-Rep 1) allele and ADH A1 allele with risk of PD. There was no statistical significance of the frequencies of ADH A1 allele between PD patients 12/200 (6%), diseased controls 13/200 (6.5%), and healthy controls 20/388 (5.2%). No strong evidence of an association was found between ADH A1 allele and PD susceptibility in our study patients. There was also no suggestion of linkage disequilibrium between NACP-Rep 1 and ADH A1 alleles.

"Mitotic drive" of expanded CTG repeats in myotonic dystrophy type 1 (DM1)

In myotonic dystrophy type 1 (DM1), an expanded CTG repeat shows repeat size instability in somatic and germ line tissues with a strong bias toward further expansion. To investigate the mechanism of this expansion bias, 29 DM1 and six normal lymphoblastoid cell lines (LBCLs) were single-cell cloned from blood cells of 18 DM1 patients and six normal subjects. In all 29 cell lines, the expanded CTG repeat alleles gradually shifted toward further expansion by "step-wise" mutations. Of these 29 cell lines, eight yielded a rapidly proliferating mutant with a gain of large repeat size that became the major allele population, eventually replacing the progenitor allele population. By mixing cell lines with different repeat expansions, we found that cells with larger CTG repeat expansion had a growth advantage over those with smaller expansions in culture. This growth advantage was attributable to increased cell proliferation mediated by Erk1,2 activation, which is negatively regulated by p21(WAF1). This phenomenon, which we designated "mitotic drive" , is a novel mechanism which can explain the expansion bias of DM1 CTG repeat instability at the tissue level, on a basis independent of the DNA-based expansion models. The lifespans of the DM1 LBCLs were significantly shorter than normal cell lines. Thus, we propose a hypothesis that DM1 LBCLs drive themselves to extinction through a process related to increased proliferation.

A "dystrophic" variant of autosomal recessive myotonia congenita caused by novel mutations in the CLCN1 gene

OBJECTIVES

To identify the disease-causing mutation and its molecular consequence for a clinically distinct type of myotonic myopathy.

BACKGROUND

The authors encountered a unique myotonic disorder of early onset in a 37-year-old man and his 47-year-old sister.

METHODS

After examining known loci of inherited myotonic disorders, the authors looked for mutations within the CLCN1 gene using single strand conformation polymorphism and direct sequencing. To investigate the disease mechanism, reverse transcriptase PCR analyses of total RNA were performed.

RESULTS

In the proband and his affected sister, two novel mutations comprising a compound heterozygous state in the CLCN1 gene were identified: 1) a base (G) insertion in exon 7 generating a premature termination codon (fs289X) in the D5 domain, and 2) a C-to-T substitution in exon 23 resulting in a missense mutation (P932L). These mutations accompanied a clinical phenotype that is distinguishable from recessive myotonia congenita by progressive generalized muscle weakness, severe distal muscle atrophy, joint contractures, high serum creatine kinase levels, and conspicuous myopathic changes on muscle histopathology. Reverse transcriptase PCR analyses detected only the P932L mutant mRNA in skeletal muscle, suggesting that the fs289X mRNA is degraded rapidly.

CONCLUSIONS

These data suggest that fs289X is a null mutation, rendering the patients with the compound heterozygous genotype of fs289X/P932L to exclusively express P932L homomeric channels that may have caused the "dystrophic" phenotype.

Large expansion of the ATTCT pentanucleotide repeat in spinocerebellar ataxia type 10

Spinocerebellar ataxia type 10 (SCA10; MIM 603516; refs 1,2) is an autosomal dominant disorder characterized by cerebellar ataxia and seizures. The gene SCA10 maps to a 3.8-cM interval on human chromosome 22q13-qter (refs 1,2). Because several other SCA subtypes show trinucleotide repeat expansions, we examined microsatellites in this region. We found an expansion of a pentanucleotide (ATTCT) repeat in intron 9 of SCA10 in all patients in five Mexican SCA10 families. There was an inverse correlation between the expansion size, up to 22.5 kb larger than the normal allele, and the age of onset (r2=0.34, P=0.018). Analysis of 562 chromosomes from unaffected individuals of various ethnic origins (including 242 chromosomes from Mexican persons) showed a range of 10 to 22 ATTCT repeats with no evidence of expansions. Our data indicate that the new SCA10 intronic ATTCT pentanucleotide repeat in SCA10 patients is unstable and represents the largest microsatellite expansion found so far in the human genome.

Variability and validity of polymorphism association studies in Parkinson's disease

BACKGROUND

In recent years, interest in gene-environment interactions has spurred a great number of association studies on polymorphism of different genes.

OBJECTIVE

To review case-control studies of genetic polymorphisms in PD, and perform meta-analysis of individual gene polymorphism.

METHODS

The authors searched the Medline database (PubMed) for publications (English language) from January 1966 to November 1999 for association studies in PD. The key words used were "PD" and "polymorphism." The authors supplemented the search with relevant references quoted in these published articles. Those with four or more independent studies of a specific gene polymorphism were subjected to meta-analysis, with the exception of cytochrome-P450 enzyme polymorphisms, for which meta-analyses results were already available in the literature.

RESULTS

The authors identified 84 studies on 14 genes, including dopamine receptors (DRD2 and DRD4), dopamine transporter (DAT), monoamine oxidase (MAOA and MAOB), catechol-O-methyltransferase (COMT), N-acetyltransferase 2 (NAT2), APOE, glutathione transferase (GSTT1, GSTM1, GSTP1, and GSTZ1), and mitochondrial genes (tRNAGlu and ND2). Four polymorphisms showed significant association with PD: slow acetylator genotypes of NAT2 (PD:control OR = 1.36), allele >188bp of the MAOB (GT)n polymorphism (OR = 2.58), the deletion allele of GSTT1 (OR = 1.34), and A4336G of tRNAGlu (OR = 3.0). No significant differences were found for the other genes.

CONCLUSION

Significant associations with PD were found in polymorphisms of NAT2, MAOB, GSTT1, and tRNAGlu. Although significant association does not imply a causal relationship between the presence of the polymorphisms and PD pathogenesis, their pathophysiologic significance should be studied further.

Polymorphism of NACP-Rep1 in Parkinson's disease: an etiologic link with essential tremor?

An allele (263bp) of the nonamyloid component of plaques (NACP)-Repl polymorphism has shown association with sporadic PD in a German population. The authors studied this polymorphism in 100 American PD patients and 100 healthy controls. The authors also studied 46 essential tremor (ET) and 55 Huntington's disease (HD) patients. Allele 263bp was significantly higher in PD patients (OR = 3.86) and ET patients (OR = 6.42) but not HD patients, compared with healthy controls. The association of allele 263bp with PD and ET suggests a possible etiologic link between these two conditions.

Mapping of the gene for a novel spinocerebellar ataxia with pure cerebellar signs and epilepsy

We investigated a family with a new type of autosomal dominant cerebellar ataxia (ADCA) in which pure cerebellar ataxia is often accompanied with epilepsy. No CAG repeat expansions were detected at the spinocerebellar ataxia (SCA) type 1, 2, 3, 6, or 7 locus, and SCAs 4 and 5 were excluded by linkage analysis. We found linkage between the disease locus and D22S274 (Zmax = 3.86 at theta = 0.00) and two other makers in 22q13-qter. Haplotype analysis of the crossover events and the multipoint linkage mapping localized the disease locus to an 8.8-cM region between D22S1177 and D22S1160.

The G209A mutation in the alpha-synuclein gene is not detected in familial cases of Parkinson disease in non-Greek and/or Italian populations

OBJECTIVE

To determine whether the G-to-A substitution at nucleotide 209 (G209A) mutation in the alpha-synuclein gene is responsible for familial Parkinson disease (PD) in the US population.

DESIGN

Polymerase chain reaction-based DNA analysis of consecutive patients with PD and family history of PD.

SETTING

A university-affiliated movement disorder clinic and a Veterans Affairs clinical research laboratory.

PATIENTS

Forty-four patients with PD and family history of PD and 29 patients with sporadic PD, all with no known Greek and/or Italian background.

RESULTS

None of the DNA samples showed the G209A mutation.

CONCLUSION

The G209A mutation is rare in US patients with familial PD.

Outcomes of therapy for Cushing's disease due to adrenocorticotropin-secreting pituitary macroadenomas

We reviewed our experience with 21 patients who had Cushing's disease due to ACTH-secreting macroadenomas to clarify the natural history of this disease. All patients had typical clinical and biochemical features of ACTH-dependent hypercortisolism. Their mean maximal tumor diameter was 1.6 +/- 0.1 cm, and the range was 1.0-2.7 cm. Six patients had cavernous sinus invasion, three had invasion of the floor of their sella, and nine had suprasellar extension. The observed remission rate was significantly lower in macroadenoma patients than in microadenoma patients (67% vs. 91%; chi 2 = 5.7; P < 0.02). Cavernous sinus invasion (odds ratio, 35; 95% confidence interval, 2.6-475; P < 0.008) and presence of a maximum tumor diameter 2.0 cm or more (odds ratio, 12.9; 95% confidence interval, 1.4-124; P < 0.02) emerged as the only predictors of residual disease after surgery. The observed recurrence rate was significantly higher in macroadenoma patients than in microadenoma patients (36% vs. 12%; chi 2 = 4.2; P < 0.05). Macroadenoma patients tended to suffer from recurrences earlier than did microadenoma patients (16 vs. 49 months). Stepwise multiple logistic regression did not identify any predictors of disease recurrence in macroadenoma patients. Eight macroadenoma patients underwent a total of nine repeat surgical procedures, but none of these resulted in clinical remissions. Only four of seven (57%) patients followed for a sufficient period of time achieved normal urinary free cortisol levels after conventional radiotherapy. Three (75%) of these four patients had re-recurrent hypercortisolism after brief periods of eucortisolism. Pharmacological agents and adrenalectomy were effective in the management of hypercortisolism in patients with residual and recurrent disease. Our results indicate that ACTH-secreting macroadenomas are more refractory to conventional treatments than are ACTH-secreting microadenomas.