Association of VEGF Gene Family Variants with Central Macular Thickness and Visual Acuity after Aflibercept Short-Term Treatment in Diabetic Patients: A Pilot Study

Predictive factors for treatment outcomes with intravitreal anti-vascular endothelial growth factor injections in diabetic macular edema in clinical practice

BACKGROUND

Intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections are the standard of care for diabetic macular edema (DME), a common complication of diabetes. This study aimed to identify factors influencing DME intravitreal anti-VEGF treatment outcomes in real-world practice.

METHODS

This was a multi-center retrospective observational study using medical chart review of participants receiving anti-VEGF injections for DME (N = 248). Demographic and clinical variables were assessed for association with best corrected visual acuity (BCVA) and central macular thickness (CMT) outcomes using regression models.

RESULTS

There was a significant improvement in BCVA (p < 0.001) and CMT (p < 0.001) after 12 months of treatment, although 21% of participants had decreased BCVA, and 41% had a < 10% CMT reduction at 12 months. Higher baseline BCVA (p = 0.022, OR=-0.024, 95% CI=-0.046,-0.004) and longer duration of diabetic retinopathy (p = 0.048, OR=-0.064, 95% CI=-0.129,-0.001) were negative predictors for BCVA response, whereas Aflibercept treatment (p = 0.017, OR = 1.107, 95% CI = 0.220,2.051) compared with other drugs and a positive "early functional response" (p < 0.001, OR=-1.393, 95% CI=-1.946,-0.857) were positive predictors. A higher baseline CMT (p < 0.001, OR = 0.019, 95% CI = 0.012,0.0261) and an "early anatomical response", (p < 0.001, OR=-1.677, 95% CI=-2.456, -0.943) were predictors for greater reduction in CMT. Overall, the variables could predict only 23% of BCVA and 52% of CMT response.

CONCLUSIONS

The study shows a significant proportion of DME patients do not respond to anti-VEGF therapy and identifies several clinical predictors for treatment outcomes.

TRIAL REGISTRATION

The study was approved through the Human Research Ethics Committee, University of Tasmania (approval number H0012902), and the Southern Adelaide Clinical Human Research Ethics Committee (approval number 86 - 067).

Dual anti-angiogenic and anti-metastatic activity of myriocin synergistically enhances the anti-tumor activity of cisplatin

PURPOSE

Tumor microenvironment consists of various kind of cells, forming complex interactions and signal transductions for tumor growth. Due to this complexity, targeting multiple kinases could yield improved clinical outcomes. In this study, we aimed to investigate the potential of myriocin, from Mycelia sterilia, as a novel dual-kinase inhibitor and suggest myriocin as a candidate for combined chemotherapy.

METHODS

We initially evaluated the anti-tumor and anti-metastatic effect of myriocin in mouse allograft tumor models. We examined the effects of myriocin on angiogenesis and tumor vasculature using in vitro, in vivo, and ex vivo models, and also tested the anti-migration effect of myriocin in in vitro models. Next, we explored the effects of myriocin alone and in combination with cisplatin on tumor growth and vascular normalization in mouse models.

RESULTS

We found that myriocin inhibited tumor growth and lung metastasis in mouse allograft tumor models. Myriocin induced normalization of the tumor vasculature in the mouse models. We also found that myriocin suppressed angiogenesis through the VEGFR2/PI3K/AKT pathway in endothelial cells (ECs), as well as cancer cell migration by blocking the IκBα/NF-κB(p65)/MMP-9 pathway. Finally, we found that myriocin enhanced the drug delivery efficacy of cisplatin by increasing the integrity of tumor vasculature in the mouse models, which synergistically increased the anti-tumor activity of cisplatin.

CONCLUSION

We suggest that myriocin is a novel potent anti-cancer agent that dually targets both VEGFR2 in ECs and IκBα in cancer cells, and exerts more pronounced anti-tumor effects than with either kinase being inhibited alone.

Identifying Genetic Biomarkers Predicting Response to Anti-Vascular Endothelial Growth Factor Injections in Diabetic Macular Edema

Intraocular anti-vascular endothelial growth factor (VEGF) therapies are the front-line treatment for diabetic macular edema (DME); however, treatment response varies widely. This study aimed to identify genetic determinants associated with anti-VEGF treatment response in DME. We performed a genome-wide association study on 220 Australian patients with DME treated with anti-VEGF therapy, genotyped on the Illumina Global Screening Array, and imputed to the Haplotype Reference Consortium panel. The primary outcome measures were changes in central macular thickness (CMT in microns) and best-corrected visual acuity (BCVA in ETDRS letters) after 12 months. Association between single nucleotide polymorphism (SNP) genotypes and DME outcomes were evaluated by linear regression, adjusting for the first three principal components, age, baseline CMT/BCVA, duration of diabetic retinopathy, and HbA1c. Two loci reached genome-wide significance (p < 5 × 10−8) for association with increased CMT: a single SNP on chromosome 6 near CASC15 (rs78466540, p = 1.16 × 10−9) and a locus on chromosome 12 near RP11-116D17.1 (top SNP rs11614480, p = 2.69 × 10−8). Four loci were significantly associated with reduction in BCVA: two loci on chromosome 11, downstream of NTM (top SNP rs148980760, p = 5.30 × 10−9) and intronic in RP11-744N12.3 (top SNP rs57801753, p = 1.71 × 10−8); one near PGAM1P1 on chromosome 5 (rs187876551, p = 1.52 × 10−8); and one near TBC1D32 on chromosome 6 (rs118074968, p = 4.94 × 10−8). In silico investigations of each locus identified multiple expression quantitative trait loci and potentially relevant candidate genes warranting further analysis. Thus, we identified multiple genetic loci predicting treatment outcomes for anti-VEGF therapies in DME. This work may potentially lead to managing DME using personalized treatment approaches.

VEGF and eNOS genes polymorphism features in patients with diabetes mellitus with and without initial non-proliferative diabetic retinopathy

The endothelial NO synthase (eNOS) and vascular endothelial growth factor (VEGF) imbalance and the polymorphism of these genes may be the predisposition for diabetic retinopathy (DR) development and progression.The aim: to analyze VEGF (rs699947 and rs3025039) and eNOS (rs2070744) genes polymorphism and their combinations in patients with type 2 diabetes mellitus (DM2) with and without initial non-proliferative DR.Materials and methods. The study included 200 patients with type 2 diabetes (155 women and 45 men, age – 43–70 years): 111 people without and 89 people with DR. The polymorphism of the regulatory regions of VEGF (rs699947 and rs3025039) and eNOS (rs2070744) genes was studied using restriction fragment length polymorphism analysis and TaqMan Real-Time PCR by. Statistical processing was carried out using the software packages Statistica 10.0, SPSS Statistics 23 and the package of original programs for volumetric processing of bioinformation.Results. The VEGF-2578 heterozygosity and two complex genotypes – VEGF-2578CA:VEGF+936CC and NOS3-786CT:VEGF-2578CA:VEGF+936CC – signifi cantly decreased in patients with DR. The predisposition to early DR development to minor genotype of eNOS gene in the NOS3-786CC:VEGF+936CT complex and signifi cantly decreased the homozygous wild-type eNOS genotype in DM2 patients with ophthalmopathology were shown. NOS3-86TT:VEGF2578AA genotype signifi cantly decreased in group with retinopathy developing and the glycated hemoglobin high level.Conclusion. Along with the clinical risk factors for the development of DR in DM2, the genetic polymorphism of the regulatory regions of the genes analyzed by us has a signifi cant weight. When analyzing potential genetic markers, it is important to consider possible joint epistatic/hypostatic effects. The complex analysis of polymorphic gene can help early prognosis of the DR development.

Long Non-Coding RNAs Gene Variants as Molecular Markers for Diabetic Retinopathy Risk and Response to Anti-VEGF Therapy

BACKGROUND

Long non-coding RNAs (lncRNAs) play essential roles in molecular diagnosis and therapeutic response in several diseases.

PURPOSE

For the first time, we aimed to evaluate the association of four lncRNAs TUG1 (rs7284767G/A), MIAT (rs1061540T/C), MALAT1 (rs3200401C/T), and SENCR (rs12420823C/T) variants with susceptibility to diabetic retinopathy (DR), disease severity, and early therapeutic response to intravitreous anti-vascular endothelial growth factor aflibercept therapy.

PATIENTS AND METHODS

This case-control study enrolled 126 adult patients with type 2 diabetes. TaqMan assays using Real-Time PCR were run for genotyping. Multivariable regression analyses were applied to assess the role of each polymorphism after the adjustment of covariates.

RESULTS

Carriers of TUG1 A/G and MIAT T/C and C/C genotypes were more likely to develop DR [OR=3.15 (95% CI=1.15-8.64), and OR=4.31 (95% CI=1.78-10.47)], while MALAT1 T/C conferred protection (OR=0.40, 95% CI=0.16-0.99). For TUG1, MALAT1, MIAT, and SENCR genotype combinations, GTCT and GCCC had a higher disease risk (P=0.012). For disease severity, MIAT T/T homozygosity was associated with higher DR grade [33.3% (T/T) vs 10% (C/C) and 4.2% (C/T) carriers, P=0.012]. Otherwise, patients with the SENCR T variant exhibited better pre-treatment best-corrected visual acuity level (p=0.021). Following aflibercept administration, carrying the TUG1 A or MIAT T/C was associated with a poor therapeutic response (OR=5.02, 95% CI=1.60-15.76, and OR=10.23, 95% CI=1.51-69.15, respectively).

CONCLUSION

The lncRNAs TUG1 (rs7284767G/A) and MIAT (rs1061540T/C) were associated with increased DR susceptibility and poor response to aflibercept treatment, while MALAT1 (rs3200401C/T) conferred protection to DR. These genetic determinants could be useful in DR risk stratification and pharmacogenetics after validation in large-scale studies.