Quercetin Impairs the Growth of Uveal Melanoma Cells by Interfering with Glucose Uptake and Metabolism

Monosomy 3 in uveal melanoma (UM) increases the risk of lethal metastases, mainly in the liver, which serves as the major site for the storage of excessive glucose and the metabolization of the dietary flavonoid quercetin. Although primary UMs with monosomy 3 exhibit a higher potential for basal glucose uptake, it remains unknown as to whether glycolytic capacity is altered in such tumors. Herein, we initially analyzed the expression of n = 151 genes involved in glycolysis and its interconnected branch, the "pentose phosphate pathway (PPP)", in the UM cohort of The Cancer Genome Atlas Study and validated the differentially expressed genes in two independent cohorts. We also evaluated the effects of quercetin on the growth, survival, and glucose metabolism of the UM cell line 92.1. The rate-limiting glycolytic enzyme PFKP was overexpressed whereas the ZBTB20 gene (locus: 3q13.31) was downregulated in the patients with metastases in all cohorts. Quercetin was able to impair proliferation, viability, glucose uptake, glycolysis, ATP synthesis, and PPP rate-limiting enzyme activity while increasing oxidative stress. UMs with monosomy 3 display a stronger potential to utilize glucose for the generation of energy and biomass. Quercetin can prevent the growth of UM cells by interfering with glucose metabolism.

Monosomy-3 Alters the Expression Profile of the Glucose Transporters GLUT1-3 in Uveal Melanoma

Monosomy-3 in uveal melanoma (UM) cells increases the risk of fatal metastases. The gene encoding the low-affinity glucose transporter GLUT2 resides on chromosome 3q26.2. Here, we analyzed the expression of the glucose transporters GLUT1, GLUT2, and GLUT3 with regard to the histological and clinical factors by performing immunohistochemistry on the primary tumors of n = 33 UM patients. UMs with monosomy-3 exhibited a 57% lower immunoreactivity for GLUT2 and a 1.8×-fold higher ratio of GLUT1 to total GLUT1-3. The combined levels of GLUT1-3 proteins were reduced in the irradiated but not the non-irradiated tumors with monosomy-3. GLUT3 expression was stronger in the irradiated samples with disomy-3 versus monosomy-3, but the ratio of the GLUT3 isoform to total GLUT1-3 did not differ with regard to the monosomy-3 status in the irradiated or non-irradiated subgroups. Systemic metastases were associated with the presence of monosomy-3 in the primary and circulating tumor cells as well as a higher GLUT1 ratio. Upregulation of the high-affinity glucose transporter GLUT1 possibly as a compensation for the low-affinity isoform GLUT2 may be enhancing the basal glucose uptake in the UM cells with monosomy-3. Prevention of hyperglycemia might, therefore, be a valuable approach to delay the lethal UM metastases.

Lower Levels of Adiponectin and Its Receptor Adipor1 in the Uveal Melanomas With Monosomy-3

Purpose

Adiponectin is an insulin-sensitizing and anticarcinogenic hormone that is encoded by a gene on chromosome 3. Here, we analyzed the expression of adiponectin and its receptor Adipor1 in primary uveal melanoma (UM) with regard to the monosomy-3 status and clinical factors, as well as the physiological response of UM cells to adiponectin.

Methods

Immunohistochemistry was performed on the primary UM of 34 patients. Circulating melanoma cells (CMC) were isolated by immunomagnetic enrichment. Monosomy-3 was evaluated by Immuno-FISH. Gene expression was analyzed using the RNAseq data of The Cancer Genome Atlas study. Cultures of choroidal melanocytes and UM were established from the samples of two patients. The proliferative potential of the UM cell lines Mel-270 and OMM-2.5 was determined by immunocytochemistry, immunoblotting, cell cycle analysis, nucleolar staining, and adenosine triphosphate (ATP) levels.

Results

UM with monosomy-3 exhibited a lower immunoreactivity for adiponectin and Adipor1, which was associated with monosomy-3-positive CMC and the development of extraocular growth or metastases. Both proteins were more abundant in the irradiated tumors and present in the cultured cells. Gene expression profile indicated the impairment of adiponectin-mediated signaling in the monosomy-3 tumors. Adiponectin induced a significant decline in the ATP levels, Ki-67 expression, cells in the G2/M phase, and nucleolar integrity in UM cultures.

Conclusions

Adiponectin deficiency appears to enhance the metastatic potential of the UM cells with monosomy-3 and the termination of tumor dormancy. Counteracting insulin resistance and improving the serum adiponectin levels might therefore be a valuable approach to prevent or delay the UM metastases.

SAT0194 LACK OF EFFICACY OF RIVAROXABAN IN THE TREATMENT OF ANTIPHOSPHOLIPID SYNDROME AND CLINICAL SIGNIFICANCE OF ANTIPHOSPHOLIPID ANTIBODIES

Background:

Chronic anticoagulation with vitamin K antagonists (VKA) is the standard treatment to prevent thrombotic events in antiphospholipid syndrome (APS). But in recent years treatment schemes began to include rivaroxaban. Use of direct oral anticoagulants (DOAC) is an attractive and often preferred alternative to VKAs in other medical settings owing to greater ease of use, fewer food and drug interactions, and lower bleeding risks [1].However, according to last guidelines, rivaroxaban should not be used in patients with triple aPL positivity due to the high risk of recurrent events [2].

Objectives:

1.To determine the risk of recurrent thrombosis in single or double positive APS patients treated with rivaroxaban.

2.Find out possible association between presence of particular antiphospholipid antibodies or high level of lupus anticoagulant (LA) and type of vascular events.

Methods:

33 patients with confirmed APS (25 female (75.8%), 8 male (24.2%), mean age 43.2±11.6 years) were included in the study. 17 (51.5%) of investigated patients had primary APS, in remaining 16 (48.5%) APS was included in the framework of SLE. 18 (54.5%) patients were treated with warfarin 2.5-7.5 mg/daily, 15 (45.5%) patients - with rivaroxaban 20mg/daily for a follow-up period of 12 months. The data is introduced as odds ratios (OR) with 95% confidence interval (CI). The results were considered significant when p <0.05.

Results:

At baseline 21 (63.6%) patients had history of arterial thrombosis, 10 (30.3%) - venous thrombosis, 17 (51.5%) - pregnancy loss. According to results of serum immunology check, 29 (87.9%) patients were anticardiolipin antibody (ACA) positive, 9 (27.3%) - LA positive, 19 (57.6%) - anti-ß2-glycoprotein antibodies (anti-ß2-gp) positive; 20 (60.6%) patients were double positive (12 (36.4%) of them had positive ACA and anti-ß2-gp, 6 (18.2%) - ACA and LA, and 2 (6.1%) - anti-ß2-gp and LA), 4 (12.1%) patients were triple positive.

No association between vascular event and/or pregnancy loss in patients with single positive ACA was found. We have found positive association between arterial thrombosis and single positive anti-ß2-gp (OR /CI 95%/ = 5.0 /2.08 – 23.06/, p< 0.05), positive association between positive LA and venous thrombosis (OR /CI 95%/ = 10 /1.7-57.7/, p< 0.05), strong positive association between positive LA and thromboembolism of pulmonary artery (OR /CI 95%/ = 46.0 /4.0-525.1/, p< 0.001), negative association between positive LA and pregnancy loss (OR /CI 95%/ =0.06 /0.03 – 0.1/, p< 0.01).

Risk of thrombosis and/or pregnancy loss was not significantly increased in double positive patients, but triple positive patients had increased risk of venous thrombosis (OR /CI 95%/ =9.4 /3.2 – 105.8/, p<0.04).

Recurrent thrombosis was detected in 16 patients: 2 patients (12.5%) were on warfarin, 14 (87.5%) - on rivaroxaban (10 (71.4%) arterial thrombosis, 4 (28.6%) venous thrombosis).

No association between warfarin 2.5-7.5 mg/daily and occurrence of recurrent thrombosis was detected. An association between use of warfarin and increased risk of bleeding was found, but the risk was not significant (OR /CI 95%/ = 7.0 /0.7 – 66/, p= 0.09). Rivaroxaban 20 mg/daily was associated with recurrent thrombosis not only for triple positive patients (p< 0.02), but also in double positive patients (OR /CI 95%/ = 21.3 /1.8 – 251/, p< 0.04).

Conclusion:

Rivaroxaban does not prevent recurrent thrombosis not only in triple positive patients, but also in single and double positive APS patients. Type of antiphospholipid antibodies can be predictive for the type of further vascular event.

References:

[1]Vittorio Pengo, Gentian Denas, Giacomo Zoppellaro et al.Rivroxaban vs warfarin in high risk patients with antiphospholipid syndrome, Blood. 2018 Sep 27; 132(13); 1357-1358.

[2]EULAR recommendations for the management of antiphospholipid syndrome in adults, Annals of the Rheumatic Diseases/ Volume 78: Issue 10:1296-1304.

Disclosure of Interests:

None declared

THU0440 LOW DOSE COLCHICINE COMBINED WITH SPORADIC INTRAMUSCULAR INJECTIONS OF BETAMETHASONE – EFFICIENT AND SUSTAINED TREATMENT OF ACUTE GOUTY ARTHRITIS

Background:

Gouty arthritis is a common, potentially disabling and increasingly prevalent disease [1]. The main goals of treatment are to treat acute arthritis, decrease uric acid (UA) levels and prevent occurrence of further attacks. According to 2016 updated EULAR evidence-based recommendations for the management of gout, the most common and efficient options include prescription of colchicine (up to 6 mg during the first day) and intra-articular injections of glucocorticoids (GC) [2]. First option often causes diarrhea, the latter is extremely traumatic and painful in this group of patients.

Objectives:

The aim of this study was to determine the efficacy of sustainability of anti-inflammatory effect of combination of low dose colchicine with sporadic intramuscular injections of betamethasone in the treatment of acute gouty arthritis.

Methods:

41 treatment naïve patients with acute gouty arthritis (27 male /65,9 %/, 14 female /34,1 %/, mean age 55,9 ± 13,7 years, mean disease duration 5,9 ± 4,4 years) were recruited in the study. On the first visit all the patients were prescribed 1.5 mg of colchicine per day and 2 intramuscular injections of betamethasone preparation (7mg-1ml) with an interval of 4 days. On the second visit (30thday) daily dose of colchicine was decreased to 1.0 mg, urate-lowering therapy (ULT) was begun. 21 patients (51,2%) received febuxostat 80 mg/day, 20 patients (48,8%) – allopurinol 100-150 mg/day.

Routine investigation included accurate collection of disease history, objective examination with determining the disease activity (Gout Activity Score /GAS/) and visual analogue scale (VAS patient), CBC, CRP, measurement of serum UA and creatinine level, urinalysis and other examinations [4]. GAS, VAS, CRP and uric acid were measured 3 times: at baseline, on 30thand 60thday of follow-up period.

Results:

Investigation had shown the following results at baseline: sUA1- 9,2 ± 1,5 mg/dl, CRP1- 24,3 ± 21,5 mg/L, VAS1- 8,3 ± 1,3 cm, GAS16,3 ± 0,7. All enrolled patients completed 60 days of treatment. Preparations were well tolerated, no serious adverse events occurred: mild dyspepsia was observed in 4 (9,8%) patients, mild hypertension – in 7 (17,1%), 10 (24,4%) patients had transient diarrhea. Only in 14 out of 41 patients (34,1 %) there was a necessity to add NSAIDs to the main scheme of treatment.

On the second visit (30thday) all investigated measures with exception for UA (sUA2- 8,8 ± 1,9 mg/dl, p>0.05) had shown significantly lower results: CRP2- 4,9±3,5 mg/dl, VAS2– 4,2±1,2 cm, GAS2- 4,9 ± 0,7 (p<0.001).

On the third visit (60thday) the following results were obtained: sUA3- 4,7 ± 1,3 mg/dl, CRP3- 3,5±2,0 mg/L, VAS3- 3,3±2,1 cm, GAS3- 3,7±0,9. All the measures were significantly lower than at baseline (p<0,001).

During all the follow-up period recurrent attacks of arthritis were observed in 6 patients (14,6%), particularly, only 2 patients experienced arthritis after the prescription of ULT.

Conclusion:

Low dose colchicine in combination with sporadic (1-2) intramuscular injections of betamethasone can present as an efficient, non-traumatic, safe and cost-effective option for the treatment of acute gouty arthritis. Moreover, according to results of our study, anti-inflammatory effect was stable even after the prescription of ULT.

References:

[1]Kuo C-F, Grainge MJ, Zhang W, et al. Global epidemiology of gout: prevalence, incidence and risk factors. Nat Rev Rheumatol 2015;11:649–62. doi:10.1038/nrrheum.2015.91

[2]Richette P, et al. 2016 updated EULAR evidence-based recommendations for the management of gout Ann Rheum Dis 2017;76:29–42. doi:10.1136/annrheumdis-2016-209707

[3]Scirè, Carlo A et al. “Development and First Validation of a Disease Activity Score for Gout.” Arthritis care & research vol. 68,10 (2016): 1530-7. doi:10.1002/acr.22844

Disclosure of Interests: :

None declared