The insulin-like growth factor type 1 receptor (IGF-1R) plays a key role in the development and progression of cancer; however, therapeutics targeting it have had disappointing results in the clinic. ...As a receptor tyrosine kinase (RTK), IGF-1R is traditionally described as an ON/OFF system, with ligand stabilizing the ON state and exclusive kinase-dependent signaling activation. Newly added to the traditional model, ubiquitin-mediated receptor downregulation and degradation was originally described as a response to ligand/receptor interaction and thus inseparable from kinase signaling activation. Yet, the classical model has proven over-simplified and insufficient to explain experimental evidence accumulated over the last decade, including kinase-independent signaling, unbalanced signaling, or dissociation between signaling and receptor downregulation. Based on the recent findings that IGF-1R “borrows” components of G-protein coupled receptor (GPCR) signaling, including β-arrestins and G-protein-related kinases, we discuss the emerging paradigm for the IGF-1R as a functional RTK/GPCR hybrid, which integrates the kinase signaling with the IGF-1R canonical GPCR characteristics. The contradictions to the classical IGF-1R signaling concept as well as the design of anti-IGF-1R therapeutics treatment are considered in the light of this paradigm shift and we advocate recognition of IGF-1R as a valid target for cancer treatment.
Background
Survival in metastasized cutaneous melanoma (CM) has been improved with the advent of inhibitors of immune checkpoints CTLA4 and PD‐1. In contrast, the response rate for inhibition of ...these checkpoints in uveal melanoma (UM) is very low. Other checkpoints including IDO and TIGIT may be targetable.
Methods
Sections from 6 patients with UM, who had undergone primary enucleation 1978—1995 and 6 paired liver metastases were stained immunohistochemically (SOX10, Melan‐A, IDO, TIGIT, and CD8). Four tumors from patients who did not develop metastasis during a mean follow‐up of 19 years, and 5 samples each of normal choroidal and liver tissue were included for comparison. The number of cells/mm2 expressing IDO, TIGIT and CD8 was counted with manual and digital image analysis methods. Retrospective data on patient and tumor characteristics was reviewed.
Results
The number of TIGIT positive cells was significantly higher in primary tumors from patients who eventually developed metastases (mean 4695 cells/mm2) than from patients who didn't (mean 1342 cells/mm2, P < 0.01) and paired metastases (463 cells/mm2, P < 0.01). The number of IDO positive cells was not significantly higher in metastatic tumors (P = 0.079), but the number of IDO and TIGIT positive cells/mm2 correlated in both hot spots (R2 = 0.24, P < 0.01) and full tumor sections (R2 = 0.35, P < 0.01).
Conclusion
The expression of immune checkpoint receptor TIGIT is increased in primary uveal melanomas that seed metastases, and correlates with the expression of checkpoint receptor IDO. Both may be future targets for therapy.
Expression of immune checkpoint receptors Indoleamine 2,3-dioxygenase and T cell Ig and ITIM domain is increased in primary choroidal melanomas from patients that later develop metastases. This may be a future target for adjuvant therapy with checkpoint inhibitors.
To develop a prognostic test based on a single blood sample obtained at the time of uveal melanoma diagnosis.
83 patients diagnosed with posterior uveal melanoma between 1996 and 2000 were included. ...Peripheral serum samples were obtained at diagnosis and kept at -80 °C until this analysis. Protein profiling of 84 cancer-related proteins was used to screen for potential biomarkers and a prognostic test that stratifies patients into metastatic risk categories was developed (serUM-Px) in a training cohort and then tested in a validation cohort.
Low serum leptin levels and high osteopontin levels were found to identify patients with poor prognosis and were therefore selected for inclusion in the final test. In the validation cohort, patient sex and American Joint Committee on Cancer stages were similarly distributed between the low, intermediate, and high metastatic risk categories. With increasing metastatic risk category, patients had shorter metastasis-free- and overall survival, as well as greater cumulative incidence of uveal melanoma-related mortality in competing risk analysis (P = 0.007, 0.018 and 0.029, respectively). In multivariate Cox regression, serUM-Px was an independent predictor of metastasis with tumor size and patient sex as covariates (hazard ratio 3.2, 95% CI 1.5-6.9).
A prognostic test based on a single peripheral venous blood sample at the time of uveal melanoma diagnosis stratifies patients into low, intermediate, and high metastatic risk categories. Prospective validation will facilitate its clinical utility.
To relate conjunctival melanoma characteristics to local control.
Retrospective, registry-based interventional study with data gathered from 10 ophthalmic oncology centres from 9 countries on 4 ...continents. Conjunctival melanoma patients diagnosed between January 2001 and December 2013 were enrolled in the study. Primary treatments included local excision, excision with cryotherapy and exenteration. Adjuvant treatments included topical chemotherapy, brachytherapy, proton and external beam radiotherapy (EBRT). Cumulative 5-year and 10-year Kaplan-Meier local recurrence rates were related to clinical and pathological T-categories of the eighth edition of the American Joint Committee on Cancer (AJCC) staging system.
288 patients had a mean initial age of 59.7±16.8 years. Clinical T-categories (cT) were cT1 (n=218,75.7%), cT2 (n=34, 11.8%), cT3 (n=15, 5.2%), cTx (n=21,7.3%) with no cT4. Primary treatment included local excision (n=161/288, 55.9%) followed by excision biopsy with cryotherapy (n=108/288, 37.5%) and exenteration (n=5/288, 1.7%). Adjuvant therapies included topical mitomycin (n=107/288, 37.1%), plaque-brachytherapy (n=55/288, 19.1%), proton-beam (n=36/288, 13.5%), topical interferon (n=20/288, 6.9%) and EBRT (n=15/288, 5.2%). Secondary exenteration was performed (n=11/283, 3.9%). Local recurrence was noted in 19.1% (median=3.6 years). Cumulative local recurrence was 5.4% (3.2-8.9%), 19.3% (14.4-25.5%) and 36.9% (26.5-49.9%) at 1, 5 and 10 years, respectively. cT3 and cT2 tumors were twice as likely to recur than cT1 tumours, but only cT3 had statistically significantly greater risk of local recurrence than T1 (p=0.013). Factors such as tumour ulceration, plica or caruncle involvement and tumour thickness were not significantly associated with an increased risk of local recurrence.
This multicentre international study showed that eighth edition of AJCC tumour staging was related to the risk of local recurrence of conjunctival melanoma after treatment. The 10-year cumulative local recurrence remains high despite current management.
To report the time trends in basic patient characteristics and the number of specimens received at a national referral center for ophthalmic pathology.
Data on patient sex, age at surgical resection ...and geographical location of the referring unit were obtained for all specimens received at the St. Erik Ophthalmic Pathology laboratory, Stockholm, Sweden, between January 1
, 1959, and December 31
, 2021.
A total of 33 057 specimens had been received, of which 14 560 (44%) came from men and 18 477 (56%) from women (for 20 patients, the sex was not specified). The average annual percent change (AAPC) in the number specimens received was + 10.5%, whereas the Swedish population increased with 0.5% per year. Patients became older throughout the period, with an average yearly increase of patient age at surgery of 0.3 years (AAPC 0.2%). Overall, women were three years older than men at surgery (59.4 versus 56.4 years, P < 0.0001) The number of specimens increased with patient age from the first to the 8
decade, after which it decreased to zero in the 11
decade. The largest portion of patients had undergone their surgery in one of the hospitals or clinics in the capital region, with four of the five largest sources corresponding to the most populous counties in the country.
During six decades, the growth in number of specimens sent to our national referral center for ophthalmic pathology has greatly outpaced the growth of the population, indicating an increasing demand for subspecialized services. Throughout the period, patients have become older, and a higher number of specimens have been submitted from female patients.
To evaluate the efficacy of intraocular injections with bevacizumab over 12 months in patients with macular edema (ME) secondary to central retinal vein occlusion (CRVO).
A prospective study ...including a randomized 6-month, sham injection-controlled, double-masked clinical trial followed by a 6-month open-label extension.
Sixty patients with ME secondary to CRVO.
At baseline, patients were randomized 1:1 to receive intraocular injections of bevacizumab or sham injections every 6 weeks for 6 months. From month 6, all patients received intraocular injections of bevacizumab every 6 weeks for 6 months.
The primary outcome measure was the proportion of patients gaining at least 15 letters at 12 months. Secondary outcome measures included mean change from baseline best-corrected visual acuity (BCVA), change in foveal thickness, and development of neovascular glaucoma.
At the end of follow-up, 18 of 30 patients (60.0%) in the bevacizumab/bevacizumab (bz/bz) group had gained ≥ 15 letters compared with 10 of 30 patients (33.3%) in the sham/bevacizumab (sh/bz) group (P < 0.05). The BCVA improved by 16.0 letters at 12 months in the bz/bz group compared with 4.6 letters in the sh/bz group (P < 0.05). In an unplanned retrospective analysis, patients aged >70 years had a significantly worse outcome when receiving delayed treatment, losing 1.4 letters (95% confidence interval CI, -9.7 to 8.4) in the sh/bz group compared with a gain of 20.1 letters (95% CI, 13.9-26.3) in the bz/bz group in patients aged <70 years (P < 0.003). The mean decrease in central retinal thickness (CRT) was 435 μm in the bz/bz group compared with 404 μm in the sh/bz group (P = not significant). No patients developed iris rubeosis during the 6-month open-label extension period. There were no events of endophthalmitis, retinal tear, or retinal detachment during the 12-month treatment period. No serious nonocular adverse events were reported.
Intraocular injections of bevacizumab given every 6 weeks for 12 months improve visual acuity (VA) and reduce ME significantly. Patients receiving delayed treatment have a limited visual improvement.
Proprietary or commercial disclosure may be found after the references.
β-Arrestins are multifunctional proteins that play central roles in G protein-coupled receptor (GPCR) trafficking and signaling. β-Arrestin1 is also recruited to the insulin-like growth factor-1 ...receptor (IGF-1R), a receptor tyrosine kinase (RTK), mediating receptor degradation and signaling. Because GPCR phosphorylation by GPCR-kinases (GRKs) governs interactions of the receptors with β-arrestins, we investigated the regulatory roles of the four widely expressed GRKs on IGF-1R signaling/degradation. By suppressing GRK expression with siRNA, we demonstrated that lowering GRK5/6 abolishes IGF1-mediated ERK and AKT activation, whereas GRK2 inhibition increases ERK activation and partially inhibits AKT signaling. Conversely, β-arrestin–mediated ERK signaling is enhanced by overexpression of GRK6 and diminished by GRK2. Similarly, we demonstrated opposing effects of GRK2 and -6 on IGF-1R degradation: GRK2 decreases whereas GRK6 enhances ligand-induced degradation. GRK2 and GRK6 coimmunoprecipitate with IGF-1R and increase IGF-1R serine phosphorylation, promoting β-arrestin1 association. Using immunoprecipitation, confocal microscopy, and FRET analysis, we demonstrated β-arrestin/IGF-1R association to be transient for GRK2 and stable for GRK6. Using bioinformatic studies we identified serines 1248 and 1291 as the major serine phosphorylation sites of the IGF-1R, and subsequent mutation analysis demonstrated clear effects on IGF-1R signaling and degradation, mirroring alterations by GRKs. Targeted mutation of S1248 recapitulates GRK2 modulation, whereas S1291 mutation resembles GRK6 effects on IGF-1R signaling/degradation, consistent with GRK isoform-specific serine phosphorylation. This study demonstrates distinct roles for GRK isoforms in IGF-1R signaling through β-arrestin binding with divergent functional outcomes.
To evaluate the efficacy of intraocular injections with bevacizumab in patients with macular edema (ME) secondary to central retinal vein occlusion (CRVO).
Prospective, randomized, sham ...injection-controlled, double-masked clinical trial.
Sixty patients with ME secondary to CRVO.
At baseline, patients were randomized 1:1 to receive intraocular injections of bevacizumab or sham injections every 6 weeks for 6 months.
The primary outcome measure was the proportion of patients gaining at least 15 letters at 6 months. Secondary outcome measures included mean change from baseline best-corrected visual acuity (BCVA), foveal thickness, and neovascular glaucoma.
At the end of follow-up, 18 of 30 patients (60.0%) in the study group had gained ≥15 letters compared with 6 of 30 patients (20.0%) in the control group (P=0.003). The BCVA improved by 14.1 letters at 24 weeks compared with a decrease of 2.0 letters in the control group (P < 0.003). The mean decrease in central retinal thickness (CRT) was significantly greater in the study group (426 μm) than in the control group (102 μm) at all time points up to week 24 (P < 0.001). No residual edema, defined as CRT <300 μm at 24 weeks, was found in 26 of 30 patients (86.7%) in the treatment group compared with 6 of 30 patients (20%) in the control group (P < 0.001). In the sham group, 5 of 30 patients (16.7%) had developed iris rubeosis at week 24. No patients in the study group had rubeosis at week 24 (P=0.052). There were no events of endophthalmitis, retinal tear, or retinal detachment during the 24-week treatment period. No serious non-ocular adverse events were reported.
Intraocular injections of bevacizumab given every 6 weeks for 6 months improve visual acuity (VA) and reduce ME significantly compared with sham.
Proprietary or commercial disclosure may be found after the references.
Uveal melanoma is the most common primary intraocular malignancy in adults, with nearly half of all patients eventually developing metastases, which are invariably fatal. Manual assessment of the ...level of expression of the tumor suppressor BRCA1-associated protein 1 (BAP1) in tumor cell nuclei can identify patients with a high risk of developing metastases, but may suffer from poor reproducibility. In this study, we verified whether artificial intelligence could predict manual assessments of BAP1 expression in 47 enucleated eyes with uveal melanoma, collected from one European and one American referral center. Digitally scanned pathology slides were divided into 8176 patches, each with a size of 256 × 256 pixels. These were in turn divided into a training cohort of 6800 patches and a validation cohort of 1376 patches. A densely-connected classification network based on deep learning was then applied to each patch. This achieved a sensitivity of 97.1%, a specificity of 98.1%, an overall diagnostic accuracy of 97.1%, and an F1-score of 97.8% for the prediction of BAP1 expression in individual high resolution patches, and slightly less with lower resolution. The area under the receiver operating characteristic (ROC) curves of the deep learning model achieved an average of 0.99. On a full tumor level, our network classified all 47 tumors identically with an ophthalmic pathologist. We conclude that this deep learning model provides an accurate and reproducible method for the prediction of BAP1 expression in uveal melanoma.
Background
In contrast to most other cancers, uveal melanoma (UM) is characterized by an absence of major improvements in patient survival during the last several decades. In this study, we examine ...changes in incidence rates, patient age and tumor size at diagnosis, treatment practices and survival for patients diagnosed in Sweden during the period 1960–2010.
Methods
All patients diagnosed with posterior UM between January 1st, 1960, and December 31st, 2009, in Sweden, were included (
n
= 3898). Trends in incidence, primary treatment modality, patient age and tumor size were analyzed. Disease-specific survival was plotted in Kaplan–Meier curves and the cumulative incidence of UM-related mortality was evaluated in competing risk analysis.
Results
Crude (6.5–11.6 cases/million/year) and age-standardized incidence rates (5.6–9.6 cases/million/year) varied between individual years during the study period, but both had a stable linear trend overall (
p
≥ 0.12). Gradually, plaque brachytherapy with ruthenium-106 replaced enucleation as the most common primary treatment. The mean patient age at diagnosis increased from 59.8 years in 1960 to 66.0 in 2009. Conversely, the mean tumor size became gradually smaller during the period. In linear regression, the basal diameter and tumor apical thickness decreased with a slope coefficient of −0.03 mm (
p
= 0.012) and −0.05 mm (
p
= 1.2 × 10
–5
) per year after 1960, respectively. Patients diagnosed after 1990 had significantly better disease-specific survival than patients diagnosed before 1990 (
p
= 2.0 × 10
–17
). Similarly, the cumulative incidence of UM-related mortality was highest for patients diagnosed 1960–1969 and 1970–1979, with slightly lower incidences for patients diagnosed 1980–1989 and even lower for those diagnosed after 1990 (
p
= 7.1 × 10
–13
). The incidence of mortality from other causes than UM did not differ between periods (
p
= 0.16).
Conclusion
In the period from 1960–2010, crude and age-standardized incidence rates of UM have remained stable in Sweden. Several other aspects have changed: Plaque brachytherapy with ruthenium-106 has replaced enucleation as the most common primary treatment modality; patients have become older and their tumors smaller at the time of diagnosis; and their survival has improved. This might indicate a beneficial survival effect of earlier diagnosis and treatment, but the potential influence from lead-time bias should be taken into consideration.
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