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1.
Clin Cancer Res ; 21(15): 3442-52, 2015 Aug 01.
Article in English | MEDLINE | ID: mdl-25878330

ABSTRACT

PURPOSE: In early clinical testing, most novel targeted anticancer therapies have limited toxicities and limited efficacy, which complicates dose and schedule selection for these agents. Confirmation of target inhibition is critical for rational drug development; however, repeated tumor biopsies are often impractical and peripheral blood mononuclear cells and normal skin are often inadequate surrogates for tumor tissue. Based upon the similarities of tumor and wound stroma, we have developed a clinical dermal granulation tissue model to evaluate novel targeted therapies. EXPERIMENTAL DESIGN: A 4-mm skin punch biopsy was used to stimulate wound healing and a repeat 5-mm punch biopsy was used to harvest the resulting granulation tissue. This assay was performed at pretreatment and on-treatment evaluating four targeted therapies, bevacizumab, everolimus, erlotinib, and panitumumab, in the context of three different clinical trials. Total and phosphorylated levels VEGFR2, S6RP, and EGFR were evaluated using ELISA-based methodologies. RESULTS: Significant and consistent inhibition of the VEGF pathway (using VEGFR2 as the readout) was observed in granulation tissue biopsies from patients treated with bevacizumab and everolimus. In addition, significant and consistent inhibition of the mTOR pathway (using S6RP as the readout) was observed in patients treated with everolimus. Finally, significant inhibition of the EGFR pathway (using EGFR as the readout) was observed in patients treated with panitumumab, but this was not observed in patients treated with erlotinib. CONCLUSIONS: Molecular analyses of dermal granulation tissue can be used as a convenient and quantitative pharmacodynamic biomarker platform for multiple classes of targeted therapies.


Subject(s)
ErbB Receptors/antagonists & inhibitors , Granulation Tissue/drug effects , TOR Serine-Threonine Kinases/antagonists & inhibitors , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Vascular Endothelial Growth Factor Receptor-2/biosynthesis , Wound Healing/drug effects , Adult , Aged , Antibodies, Monoclonal/administration & dosage , Bevacizumab/administration & dosage , Biopsy, Needle , Clinical Trials as Topic , Disease-Free Survival , Drug Evaluation, Preclinical , ErbB Receptors/genetics , Erlotinib Hydrochloride/administration & dosage , Everolimus/administration & dosage , Female , Granulation Tissue/pathology , Humans , Male , Middle Aged , Panitumumab , Skin/drug effects , TOR Serine-Threonine Kinases/genetics , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor Receptor-2/genetics
2.
Mol Cancer Ther ; 14(4): 1048-56, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25695956

ABSTRACT

A novel combination of bevacizumab and everolimus was evaluated in refractory colorectal cancer patients in a phase II trial. In this retrospective analysis, plasma samples from 49 patients were tested for over 40 biomarkers at baseline and after one or two cycles of drug administration. Analyte levels at baseline and change on-treatment were correlated with progression-free survival (PFS) and overall survival (OS) using univariate Cox proportional hazard modeling. Multivariable analyses were conducted using Cox modeling. Significant changes in multiple markers were observed following bevacizumab and everolimus treatment. Baseline levels of six markers significantly correlated with PFS and OS, including CRP, Gro-α, IGFBP-1, TF, ICAM-1, and TSP-2 (P < 0.05). At C2D1, changes of IGFBP-3, TGFß-R3, and IGFBP-2 correlated with PFS and OS. Prognostic models were developed for OS and PFS (P = 0.0002 and 0.004, respectively). The baseline model for OS consisted of CRP, Gro-α, and TF, while the on-treatment model at C2D1 included IGFBP-2, IGFBP-3, and TGFß-R3. These data demonstrated that multiple biomarkers were significantly modulated in response to bevacizumab and everolimus. Several markers correlated with both PFS and OS. Interestingly, these markers are known to be associated with inflammation and IGF signaling, key modulators of mTOR biology.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/blood , Colorectal Neoplasms/drug therapy , Bevacizumab/administration & dosage , Biomarkers/blood , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , Everolimus/administration & dosage , Humans , Neoplasm Metastasis , Prognosis , Treatment Outcome
3.
Comput Biol Med ; 57: 123-9, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25553357

ABSTRACT

A proper internal validation is necessary for the development of a reliable and reproducible prognostic model for external validation. Variable selection is an important step for building prognostic models. However, not many existing approaches couple the ability to specify the number of covariates in the model with a cross-validation algorithm. We describe a user-friendly SAS macro that implements a score selection method and a leave-one-out cross-validation approach. We discuss the method and applications behind this algorithm, as well as details of the SAS macro.


Subject(s)
Biomarkers , Clinical Trials as Topic , Computer Simulation , Prognosis , Survival Analysis , Algorithms , Computational Biology , Humans , Reproducibility of Results
4.
Ann Surg ; 258(6): 879-86, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23657083

ABSTRACT

OBJECTIVE: To determine whether 1 of 2 vaccines based on dendritic cells (DCs) and poxvectors encoding CEA (carcinoembryonic antigen) and MUC1 (PANVAC) would lengthen survival in patients with resected metastases of colorectal cancer (CRC). BACKGROUND: Recurrences after complete resections of metastatic CRC remain frequent. Immune responses to CRC are associated with fewer recurrences, suggesting a role for cancer vaccines as adjuvant therapy. Both DCs and poxvectors are potent stimulators of immune responses against cancer antigens. METHODS: Patients, disease-free after CRC metastasectomy and perioperative chemotherapy (n = 74), were randomized to injections of autologous DCs modified with PANVAC (DC/PANVAC) or PANVAC with per injection GM-CSF (granulocyte-macrophage colony-stimulating factor). Endpoints were recurrence-free survival overall survival, and rate of CEA-specific immune responses. Clinical outcome was compared with that of an unvaccinated, contemporary group of patients who had undergone CRC metastasectomy, received similar perioperative therapy, and would have otherwise been eligible for the study. RESULTS: Recurrence-free survival at 2 years was similar (47% and 55% for DC/PANVAC and PANVAC/GM-CSF, respectively) (χ P = 0.48). At a median follow-up of 35.7 months, there were 2 of 37 deaths in the DC/PANVAC arm and 5 of 37 deaths in the PANVAC/GM-CSF arm. The rate and magnitude of T-cell responses against CEA was statistically similar between study arms. As a group, vaccinated patients had superior survival compared with the contemporary unvaccinated group. CONCLUSIONS: Both DC and poxvector vaccines have similar activity. Survival was longer for vaccinated patients than for a contemporary unvaccinated group, suggesting that a randomized trial of poxvector vaccinations compared with standard follow-up after metastasectomy is warranted. (NCT00103142).


Subject(s)
Cancer Vaccines , Carcinoembryonic Antigen , Colorectal Neoplasms/prevention & control , Dendritic Cells , Granulocyte-Macrophage Colony-Stimulating Factor , Immunization/methods , Membrane Glycoproteins , Mucin-1 , Neoplasm Recurrence, Local/prevention & control , Adult , Aged , Carcinoembryonic Antigen/genetics , Colorectal Neoplasms/pathology , Colorectal Neoplasms/surgery , Disease-Free Survival , Female , Humans , Male , Middle Aged , Mucin-1/genetics , Neoplasm Metastasis , Poxviridae/genetics
5.
Cancer Med ; 2(2): 234-42, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23634291

ABSTRACT

A novel combination of capecitabine, oxaliplatin, and bevacizumab was evaluated in colorectal cancer patients enrolled in a phase II clinical trial. In this retrospective analysis, plasma samples from patients receiving capecitabine, oxaliplatin, and bevacizumab were analyzed to investigate biomarkers of clinical benefit. Forty-one protein biomarkers were tested in 38 patients at baseline and after two cycles of drug administration. Correlations among analytes were evaluated by Spearman analysis. Analyte levels at baseline and changes on-treatment were correlated with progression-free survival (PFS) and overall survival (OS) by univariate analysis. Multivariate analyses were determined using the Cox proportional hazard model. Time to event analyses were evaluated by Kaplan-Meier analysis and compared by log-rank test. Baseline levels of vWF and Ang-2 significantly correlated with PFS, while levels of VCAM-1, vWF, TSP-2, IL-8, MMP-2, and Ang-2 correlated with OS (P < 0.05). The fold change of IGF-1 levels from baseline to the end of cycle 2 was correlated with PFS, while fold changes of Ang-2, TSP-2, and TGF-ß2 correlated with OS. A baseline signature of Ang-2, IGFBP-3, IL-6, and VCAM-1 identified a low-risk and high-risk group of patients (OS: 33.9 months vs. 18.1 months, respectively, P = 0.016). For treatment-related changes, a signature consisting of Ang-2, E-Cadherin, IL-6, MCP-1, OPN, and TGF-ß1 was able to stratify patients into high- and low-risk groups (PFS: 7.7 months vs. 15.5 months, P = 0.004). Multiplex analysis of patient plasma in this trial identified several baseline- and treatment-related biomarkers associated with clinical outcome. These findings merit further exploration in larger, controlled clinical trials.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers, Tumor/blood , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/metabolism , Adult , Aged , Aged, 80 and over , Angiogenesis Inhibitors/adverse effects , Angiogenesis Inhibitors/therapeutic use , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , Antimetabolites, Antineoplastic/adverse effects , Antimetabolites, Antineoplastic/therapeutic use , Antineoplastic Agents/adverse effects , Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bevacizumab , Capecitabine , Colorectal Neoplasms/genetics , Deoxycytidine/adverse effects , Deoxycytidine/analogs & derivatives , Deoxycytidine/therapeutic use , Disease-Free Survival , Female , Fluorouracil/adverse effects , Fluorouracil/analogs & derivatives , Fluorouracil/therapeutic use , Humans , Male , Middle Aged , Neovascularization, Pathologic , Organoplatinum Compounds/adverse effects , Organoplatinum Compounds/therapeutic use , Oxaliplatin , Retrospective Studies , Treatment Outcome , Young Adult
6.
J Gastrointest Oncol ; 4(1): 8-13, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23450004

ABSTRACT

BACKGROUND: Ampulla of Vater carcinomas are rare malignancies that have been traditionally treated with radical surgical resection. Given the mortality associated with pancreaticoduodenectomy, some patients may benefit from local resection. A single-institution outcomes analysis was performed to define the role of local resection. METHODS: Patients undergoing local resection (ampullectomy) for ampullary carcinomas at Duke University between 1976 and 2010 were analyzed retrospectively. Time-to-event analysis was conducted analyzing all patients undergoing surgery, with and without adjuvant chemoradiation therapy (CRT). Overall survival (OS), local control (LC), metastases-free survival (MFS), and disease-free survival (DFS) were studied using Kaplan-Meier analysis. RESULTS: A total of 17 patients with invasive carcinoma underwent ampullectomy. The 3-and 5-year LC, MFS, DFS and OS rates were 36% and 24%, 68% and 54%, 31% and 21%, and 35% and 21%, respectively. Patients receiving adjuvant CRT did not appear to have improved outcomes compared with surgery alone, although this group tended to have poorer histological grade, more advanced tumor staging and involved surgical margins. CONCLUSIONS: Ampullectomy for invasive ampullary adenocarcinomas is a safe procedure but does not offer satisfactory long-term results, mostly due to high local failure rates. Adjuvant CRT therapy does not appear to offer increased local control or survival benefit following ampullectomy, although these results may suffer from selection bias and small sample size. Local resection should be limited to benign ampullary lesions or patients with very small, early tumors with favorable histologic features where radical resection is not feasible.

7.
Langmuir ; 29(12): 3935-42, 2013 Mar 26.
Article in English | MEDLINE | ID: mdl-23421597

ABSTRACT

We report a rapid method of depositing phosphonic acid molecular groups onto conductive metal oxide surfaces. Solutions of pentafluorobenzyl phosphonic acid (PFBPA) were deposited on indium tin oxide, indium zinc oxide, nickel oxide, and zinc oxide by spray coating substrates heated to temperatures between 25 and 150 °C using a 60 s exposure time. Comparisons of coverage and changes in work function were made to the more conventional dip-coating method utilizing a 1 h exposure time. The data show that the work function shifts and surface coverage by the phosphonic acid were similar to or greater than those obtained by the dip-coating method. When the deposition temperature was increased, the magnitude of the surface coverage and work function shift was also found to increase. The rapid exposure of the spray coating was found to result in less etching of zinc-containing oxides than the dip-coating method. Bulk heterojunction solar cells made of polyhexylthiophene (P3HT) and bis-indene-C60 (ICBA) were tested with PFBPA dip and spray-modified ITO substrates as well as poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS)-modified ITO. The spray-modified ITO solar cells showed a similar open circuit voltage (VOC) and fill factor (FF) and a less than 5% lower short circuit current density (JSC) and power conversion efficiency (PCE) than the dip- and PEDOT:PSS-modified ITO. These results demonstrate a potential path to a scalable method to deposit phosphonic acid surface modifiers on metal oxides while overcoming the limitations of other techniques that require long exposure and post-processing times.

8.
ACS Appl Mater Interfaces ; 4(12): 6711-9, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23127918

ABSTRACT

Organic/inorganic multilayer barrier films play an important role in the semihermetic packaging of organic electronic devices. With the rise in use of flexible organic electronics, there exists the potential for mechanical failure due to the loss of adhesion/cohesion when exposed to harsh environmental operating conditions. Although barrier performance has been the predominant metric for evaluating these encapsulation films, interfacial adhesion between the organic/inorganic barrier films and factors that influence their mechanical strength and reliability has received little attention. In this work, we present the interfacial fracture toughness of a model organic/inorganic multilayer barrier (SiN(x)-PMMA). Data from four point bending (FPB) tests showed that adhesive failure occurred between the SiN(x) and PMMA, and that the adhesion increased from 4.8 to 10 J/m(2) by using a variety of chemical treatments to vary the surface energy at the interface. Moreover, the adhesion strength increased to 28 J/m(2) by creating strong covalent bonds at the interface. Overall, three factors were found to have the greatest impact on the interfacial fracture toughness which were (a) increasing the polar component of the surface energy, (b) creating strong covalent bonds at the organic/inorganic interface, and (c) by increasing the plastic zone size at the crack tip by increasing the thickness of the PMMA layer.

9.
J Neurooncol ; 107(1): 155-64, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21986722

ABSTRACT

We evaluated the efficacy of carboplatin, irinotecan, and bevacizumab among bevacizumab-naïve, recurrent glioblastoma (GBM) patients in a phase 2, open-label, single arm trial. Forty eligible patients received carboplatin (area under the plasma curve [AUC] 4 mg/ml-min) on day one, while bevacizumab (10 mg/kg) and irinotecan (340 mg/m(2) for patients on CYP3A-enzyme-inducing anti-epileptics [EIAEDs] and 125 mg/m(2) for patients not on EIAEDs) were administered on days 1 and 14 of every 28-day cycle. Patients were evaluated after each of the first two cycles and then after every other cycle. Treatment continued until progressive disease, unacceptable toxicity, non-compliance, or voluntary withdrawal. The primary endpoint was progression-free survival at 6 months (PFS-6) and secondary endpoints included safety and median overall survival (OS). All patients had progression after standard therapy. The median age was 51 years. Sixteen patients (40%) had a KPS of 90-100, while 27 (68%) were at first progression. The median time from original diagnosis was 11.4 months. The PFS-6 rate was 46.5% (95% CI: 30.4, 61.0%) and the median OS was 8.3 months [95% confidence interval (CI): 5.9, and 10.7 months]. Grade 4 events were primarily hematologic and included neutropenia and thrombocytopenia in 20 and 10%, respectively. The most common grade 3 events were neutropenia, thrombocytopenia, fatigue, and infection in 25, 20, 13, and 10%, respectively. Eleven patients (28%) discontinued study therapy due to toxicity and 17 patients (43%) required dose modification. One patient died due to treatment-related intestinal perforation. The addition of carboplatin and irinotecan to bevacizumab significantly increases toxicity but does not improve anti-tumor activity to that achieved historically with single-agent bevacizumab among bevacizumab-naïve, recurrent GBM patients. (ClinicalTrials.gov number NCT00953121).


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Brain Neoplasms/drug therapy , Glioblastoma/drug therapy , Adult , Aged , Antibodies, Monoclonal, Humanized/administration & dosage , Bevacizumab , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Camptothecin/administration & dosage , Camptothecin/analogs & derivatives , Carboplatin/administration & dosage , Female , Follow-Up Studies , Glioblastoma/mortality , Glioblastoma/pathology , Humans , Irinotecan , Male , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/mortality , Neoplasm Recurrence, Local/pathology , Survival Rate , Treatment Outcome
10.
Invest Ophthalmol Vis Sci ; 50(7): 3116-27, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19324860

ABSTRACT

PURPOSE: Several nonsyndromic high-grade myopia loci have been mapped primarily by microsatellite markers and a limited number of pedigrees. In this study, whole-genome linkage scans were performed for high-grade myopia, using single nucleotide polymorphisms (SNPs) in 254 families from five independent sites. METHODS: Genomic DNA samples from 1411 subjects were genotyped (Linkage Panel IVb; Illumina, San Diego, CA). Linkage analyses were performed on 1201 samples from 10 Asian, 12 African-American, and 221 Caucasian families, screening for 5744 SNPs after quality-control exclusions. Two disease states defined by sphere (SPH) and spherical equivalence (SE; sphere+cylinder/2) were analyzed. Parametric and nonparametric two-point and multipoint linkage analyses were performed using the FASTLINK, HOMOG, and MERLIN programs. Multiple stratified datasets were examined, including overall, center-specific, and race-specific. Linkage regions were declared suggestive if they had a peak LOD score >or= 1.5. RESULTS: The MYP1, MYP3, MYP6, MYP11, MYP12, and MYP14 loci were replicated. The novel region q34.11 on chromosome 9 (max NPL= 2.07 at rs913275) was identified. Chromosome 12, region q21.2-24.12 (36.59 cM, MYP3 locus) showed significant linkage (peak HLOD = 3.48) at rs337663 in the overall dataset by SPH and was detected by the Duke, Asian, and Caucasian subsets as well. Potential shared interval was race dependent-a 9.4-cM region (rs163016-rs1520724) driven by the Asian subset and a 13.43-cM region (rs163016-rs1520724) driven by the Caucasian subset. CONCLUSIONS: The present study is the largest linkage scan to date for familial high-grade myopia. The outcomes will facilitate the identification of genes implicated in myopic refractive error development and ocular growth.


Subject(s)
Genetic Linkage , Genome, Human , Myopia, Degenerative/genetics , Polymorphism, Single Nucleotide , Adolescent , Adult , Black or African American/genetics , Asian People/genetics , Chromosomes, Human, Pair 12/genetics , Chromosomes, Human, Pair 9/genetics , Female , Genotype , Humans , International Cooperation , Lod Score , Male , Middle Aged , Pedigree , Quantitative Trait Loci , White People/genetics , Young Adult
11.
Gynecol Oncol ; 112(3): 511-6, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19144394

ABSTRACT

OBJECTIVE: We sought to assess the accuracy of a preoperative grade 1 designation and role of lymphadenectomy in women with preoperative grade 1 endometrial cancer. METHODS: A retrospective analysis of patients diagnosed with preoperative grade 1 endometrial cancer from 1970 to 2006 was conducted. Inclusion criteria were preoperative grade 1 disease and hysterectomy with or without surgical staging. RESULTS: 581 patients who underwent surgery for preoperative grade 1 cancer were identified. Lymphadenectomy was performed in 46%. Pelvic and aortic node metastases were identified in 5.4% and 3.2% patients who underwent lymphadenectomy. 9.7% were upgraded intraoperatively and 25% were upgraded on final pathology with 22% having grade 2 and 3% grade 3 disease. 22.5% with grade 1 disease intraoperatively were upgraded on final pathology, with 21.1% having grade 2 and 1.4% grade 3 disease. 9% had advanced stage disease. 20% of patients with disease limited to the uterus had adverse features including high risk histologic variants, grade 3 disease, myometrial invasion >1/2, and/or cervical involvement. After adjusting for risk factors there was no significant difference in OS (HR 1.00, p=0.992) or PFS (HR 0.96, p=0.815) between the patients who did or did not undergo surgical staging. CONCLUSION: A substantial number of patients with grade 1 endometrial cancer based on preoperative and intraoperative assessments have higher grade disease on final pathology. Although lymphadenectomy does not affect survival in this group it may identify patients with advanced disease and assist in tailoring adjuvant therapy for those with adverse risk factors.


Subject(s)
Endometrial Neoplasms/surgery , Adult , Aged , Aged, 80 and over , Disease-Free Survival , Endometrial Neoplasms/pathology , Endometrial Neoplasms/therapy , Female , Humans , Lymph Node Excision , Lymph Nodes/pathology , Lymph Nodes/surgery , Middle Aged , Neoplasm Staging , Retrospective Studies , Risk Factors , Young Adult
12.
Invest Ophthalmol Vis Sci ; 50(4): 1552-8, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19098318

ABSTRACT

PURPOSE: X-linked high myopia with mild cone dysfunction and color vision defects has been mapped to chromosome Xq28 (MYP1 locus). CXorf2/TEX28 is a nested, intercalated gene within the red-green opsin cone pigment gene tandem array on Xq28. The authors investigated whether TEX28 gene alterations were associated with the Xq28-linked myopia phenotype. Genomic DNA from five pedigrees (with high myopia and either protanopia or deuteranopia) that mapped to Xq28 were screened for TEX28 copy number variations (CNVs) and sequence variants. METHODS: To examine for CNVs, ultra-high resolution array-comparative genomic hybridization (array-CGH) assays were performed comparing the subject genomic DNA with control samples (two pairs from two pedigrees). Opsin or TEX28 gene-targeted quantitative real-time gene expression assays (comparative CT method) were performed to validate the array-CGH findings. All exons of TEX28, including intron/exon boundaries, were amplified and sequenced using standard techniques. RESULTS: Array-CGH findings revealed predicted duplications in affected patient samples. Although only three copies of TEX28 were previously reported within the opsin array, quantitative real-time analysis of the TEX28 targeted assay of affected male or carrier female individuals in these pedigrees revealed either fewer (one) or more (four or five) copies than did related and control unaffected individuals. Sequence analysis of TEX28 did not reveal any variants associated with the disease status. CONCLUSIONS: CNVs have been proposed to play a role in disease inheritance and susceptibility as they affect gene dosage. TEX28 gene CNVs appear to be associated with the MYP1 X-linked myopia phenotypes.


Subject(s)
Color Vision Defects/genetics , Genetic Diseases, X-Linked/genetics , Membrane Proteins/genetics , Myopia, Degenerative/genetics , Retinal Cone Photoreceptor Cells/pathology , Retinal Diseases/genetics , Female , Gene Dosage , Gene Expression Profiling , Genotype , Humans , Male , Nucleic Acid Hybridization , Opsins/genetics , Pedigree , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction
13.
Mol Vis ; 14: 387-93, 2008 Mar 04.
Article in English | MEDLINE | ID: mdl-18334955

ABSTRACT

PURPOSE: The membrane-type frizzled-related protein (MFRP) gene is selectively expressed in the retinal pigment epithelium and ciliary body, and mutations of this gene cause nanophthalmos. The MFRP gene may not be essential for retinal function but has been hypothesized to play a role in ocular axial length regulation. The involvement of the MFRP gene in moderate to high hyperopic, isolated microphthalmic/anophthalmic, and high myopic patients was tested in two phases: a mutation screening/sequence variant discovery phase and a genetic association study phase. METHODS: Eleven hyperopic, ten microphthalmic/anophthalmic, and seven non-syndromic high-grade myopic patients of varying ages and 11 control subjects participated in the mutation screening phase. Sixteen primer pairs were designed to amplify the 13 exons of the MFRP gene including intron/exon boundaries. Polymerase chain reactions were performed, and amplified products were sequenced using standard techniques. Normal and affected individual DNA sequences were compared alongside the known reference sequence (UCSC genome browser) for the MFRP gene. The genetic association study included 146 multiplex non-syndromic high-grade myopia families. Seventeen intragenic and flanking single nucleotide polymorphisms (SNPs) were chosen for the MFRP gene and genotyped in the large data set using the Taqman allelic discrimination assay. The family-based association Pedigree Disequilibrium Test (PDT) and GenoPDT were performed. RESULTS: The average spherical refractive error of the hyperopic patient cohort was +4.21 diopters (D; range +2.00 to +9.25 D) and of the myopic patient cohort was -12.36 D (range -8.25 to -14.50 D). A total of 16 SNPs were identified by direct sequencing. No significant association was determined between the 16 MFRP gene SNPs and the moderate to high hyperopia, microphthalmia/anophthalmia affection status, and high myopia. Family based association analysis did not reveal any association between the 17 SNPs genotyped in the larger family data set for any refractive error type. CONCLUSIONS: Sequence variants of the MFRP gene do not appear to be associated with either the less severe forms of hyperopia, extreme forms of limited eye growth and development, or high myopia. These results indicate that the MFRP gene may not play a role in regulating ocular axial length in these phenotypes.


Subject(s)
Genetic Predisposition to Disease , Hyperopia/genetics , Membrane Proteins/genetics , Microphthalmos/genetics , Mutation/genetics , Myopia/genetics , Base Sequence , Chromosomes, Human, Pair 11/genetics , DNA Mutational Analysis , Exons/genetics , Family , Humans , Linkage Disequilibrium/genetics , Phenotype , Refractometry
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