CLDN18.2 BiTE Engages Effector and Regulatory T Cells for Antitumor Immune Response in Preclinical Models of Pancreatic Cancer.

BACKGROUND & AIMS: BiTE (bispecific T-cell engager) immune therapy has demonstrated clinical activity in multiple tumor indications, but its influence in the tumor microenvironment remains unclear. CLDN18.2 is overexpressed in solid tumors including gastric cancer (GC) and pancreatic ductal adenocarcinoma (PDAC), both of which are characterized by the presence of immunosuppressive cells, including regulatory T cells (Tregs) and few effector T cells (Teffs). METHODS: We evaluated the activity of AMG 910, a CLDN18.2-targeted half-life extended (HLE) BiTE molecule, in GC and PDAC preclinical models and cocultured Tregs and Teffs in the presence of CLDN18.2-HLE-BiTE. RESULTS: AMG 910 induced potent, specific cytotoxicity in GC and PDAC cell lines. In GSU and SNU-620 GC xenograft models, AMG 910 engaged human CD3+ T cells with tumor cells, resulting in significant antitumor activity. AMG 910 monotherapy, in combination with a programmed death-1 (PD-1) inhibitor, suppressed tumor growth and enhanced survival in an orthotopic Panc4.14 PDAC model. Moreover, Treg infusion enhanced the antitumor efficacy of AMG 910 in the Panc4.14 model. In syngeneic KPC models of PDAC, treatment with a mouse surrogate CLDN18.2-HLE-BiTE (muCLDN18.2-HLE-BiTE) or the combination with an anti-PD-1 antibody significantly inhibited tumor growth. Tregs isolated from mice bearing KPC tumors that were treated with muCLDN18.2-HLE-BiTE showed decreased T cell suppressive activity and enhanced Teff cytotoxic activity, associated with increased production of type I cytokines and expression of Teff gene signatures. CONCLUSIONS: Our data suggest that BiTE molecule treatment converts Treg function from immunosuppressive to immune enhancing, leading to antitumor activity in immunologically "cold" tumors.

SUMOylation regulates Rb hyperphosphorylation and inactivation in uveal melanoma.

Small ubiquitin-like modifier (SUMO)ylation is one of the posttranslational modifications and is implicated in many tumor types. Modulation of SUMOylation can affect tumor progression, but the underlying mechanisms remain unclear. Here, we show that, for the first time, in uveal melanoma (UM), the most common intraocular malignancy in adults, global SUMOylation is upregulated and participates in tumor growth. Inhibition of SUMOylation in UM is sufficient to reduce tumor growth both in vitro and in vivo. Furthermore, we found that retinoblastoma protein (Rb) is a target protein and a critical downstream effector of the upregulated SUMOylation activity in UM. Increased SUMOylation of the Rb protein leads to its hyperphosphorylation and inactivation in UM cells, promoting UM cell proliferation. In summary, our results provide novel insight into the mechanism underlying SUMOylation-regulated tumor growth in UM.

Ocular toxicity of intravitreal melphalan for retinoblastoma in Chinese patients.

BACKGROUND: To evaluate the efficacy, complications, and clinical characteristics, including the ocular toxicity, of intravitreal melphalan(IVM) treatment for vitreous seeding in Chinese retinoblastoma patients. METHODS: This was a retrospective, non-comparative analysis including 30 consecutive eyes of 23 patients with viable persistent or recurrent vitreous seeding following retinoblastoma treatment. All of the eyes received IVM injections (20-33 µg). Vitreous seeding control, determination of the ocular toxicity, and the clinical characteristics of intravitreal melphalan treatments were observed. RESULTS: The mean patient age at the time of the injection was 28 months (median = 22 months, range = 12-50 months). In total, 80 injections were administered in 30 eyes, the overall enucleation-free survival rate was 83.3% (25/30). The complications included retinal pigment epithelium (RPE) and choroidal atrophy (19/30, 63.3%), pupillary synechiae (13/30, 43.3%), iris atrophy (12/30, 40%), retinal vascular occlusion (12/30, 40.0%), optic atrophy (6/30, 20%), vitreous hemorrhage (3/30, 10%), persistent hypotonia and phthisis bulbi (4/30 13.3%), and cataracts (8/30, 26.6%). Twelve eyes demonstrated grade 3 or greater IVM-associated retinal or anterior segment toxicity post injection. Mean dosage given showed significant difference between the groups. There were no significant differences in the retinal toxicity grades regarding the seed classification or seed regression patterns. CONCLUSIONS: Intravitreal melphalan is an effective treatment for refractory vitreous seeding from retinoblastoma, but exhibits both anterior and posterior segment toxicity in Chinese patients.

A Staged Procedure in the Treatment of Primary Lacrimal Sac Epithelial Malignancy: A Retrospective Cases Analysis.

PURPOSE: To determine the effect of a staged procedure in the treatment of primary lacrimal sac epithelial malignancy. METHODS: This is a retrospective case series of 18 consecutive patients with primary lacrimal sac epithelial malignancy treated at an orbital tumor referral center between 2002 and 2017. Study was conducted in compliance with the Declaration of Helsinki. All patients underwent biopsy of the mass to confirm the diagnosis pathologically. Chemotherapy concurrent with radiotherapy was delivered to the patients to reduce and concrete the tumor prior to surgery. En bloc resection of the lacrimal sac malignancy and nasolacrimal duct was followed. RESULTS: Eleven patients were male and 7 patients were female. The median follow-up time was 72.2 months. Nine patients had squamous cell carcinoma, 7 poorly differentiated carcinoma, 1 transitional cell carcinoma, and 1 adenoid cystic carcinoma. After chemotherapy and radiotherapy, the tumor volume was reduced significantly (p < 0.0001). En bloc resection of the lacrimal sac malignancy was performed in all patients with concurrent partial ethmoidectomy in 8 patients and medial maxillectomy in 5 patients. One patient (5.6%) suffered from adenoid cystic carcinoma died of metastatic disease. Two patients (11.1%) with local recurrence received reoperation, and 1 patient (5.6%) with pulmonary metastasis received gamma knife radiosurgery. These patients are alive with no evidence of tumor. Other patients are alive without evidence of disease at last follow up. No patient had new onset of lymph node enlargement during and after the treatment. CONCLUSIONS: The staged procedure is a promising method for the treatment of primary lacrimal sac epithelial malignancy with no postoperative lymph node metastasis.

Intraocular medulloepithelioma clinical features and management of 11 cases.

AIMS: To describe the clinical features, imaging characteristics, histopathology, treatment and outcomes of intraocular medulloepithelioma. METHODS: Medical records of 11 patients with clinically or histopathologically confirmed medulloepithelioma were retrieved and reviewed. Clinical features, diagnostic challenges, imaging characteristics, management, histopathology and prognosis were assessed. RESULTS: The median age of the patients at initial diagnosis was 4 years, with the most common manifestations being leukocoria (five eyes), loss of vision (four eyes), ocular pain (one eye) and ophthalmic screening (one eye). The clinical signs include a grey-white ciliary body lesion, cataract or lens subluxation, secondary glaucoma and evident cysts. The ultrasound biomicroscopy (UBM) imaging most commonly displays ciliary body mass with intratumoural cysts (nine eyes). Three patients underwent surgery for cataract or glaucoma while the tumours were incidentally found. Two of the three patients managed by eye preserve treatments eventually required enucleation because of local tumour recurrence or phthisis. One patient treated with intra-arterial chemotherapy and cryotherapy had successful tumour regression and globe salvage. CONCLUSIONS: Initial misdiagnosis, delay in diagnosis and subsequent misdirected management is not uncommon in medulloepithelioma. The presence of multiple cysts in the tumour and retrolental neoplastic cyclitic membrane detected by UBM can offer certain information. Selective intra-arterial melphalan may prevent further tumour growth, but longer follow-up is necessary until treatment efficacy is fully evaluated.

STING promotes invasion and migration of uveal melanoma through p38­MAPK signaling.

Uveal melanoma (UM) is the most common intraocular malignant tumor in adults, with a lack of effective treatment for metastasis and a poor prognosis. Stimulator of interferon genes (STING, also known as TMEM173) plays an important role in tumor development by regulating cell proliferation, metastasis and other cellular processes. However, the function of STING in UM remains unclear and requires further investigation. The present study analyzed the expression status of STING to elucidate the mechanisms underlying UM. The correlation between STING and the prognosis of UM was evaluated based on UM RNA­seq data and clinical information extracted from The Cancer Genome Atlas database. Quantification of STING in UM cell lines and tissues was performed using the Wes Separation protein immunoassay. The effects of STING on the proliferation, migration and invasion of UM cells were investigated using Cell Counting Kit­8, Transwell and wound healing experiments. Survival analysis demonstrated that high levels of STING in UM tissues indicated a poor prognosis. The expression of STING in UM tissues was higher than that in the choroid membranes. Furthermore, it was found that downregulation of STING expression in UM cells suppressed migration and invasion, whereas overexpression of STING significantly promoted migration and invasion. Notably, STING had no significant effect on UM cell proliferation. It was also identified that STING positively upregulated the phosphorylation of p38 mitogen­activated protein kinase (p38­MAPK) in UM cells, enhancing cell migration and invasion, which the p38­MAPK inhibitor SB203580 reversed. Finally, the results of the present study demonstrated that high STING expression in UM indicates a poor prognosis. STING was revealed to promote the migration and invasion of UM cells through p38­MAPK signaling.

Acute spontaneous vortex vein occlusion: clinical features, multimodal imaging and natural course.

AIMS: To describe the clinical features, multimodal imaging, treatments and natural course of acute spontaneous vortex vein occlusion. METHODS: Clinical data were collected on nine patients with acute vortex vein occlusion. The symptoms and signs, multimodal imaging, treatments and follow-up results were summarised. RESULTS: Six patients (66.7%) were men and three (33.3%) were women. The mean age was 47.8±15.4 years. Patients were initially misdiagnosed as having choroidal tumour (66.7%), scleritis (22.2%) and peripheral exudative haemorrhagic chorioretinopathy (11.1%). The related clinical characteristics included choroidal pseudo-tumour (100%), anterior segment injection (88.9%), acute ocular pain (77.8%), transient blurred vision (66.7%) and subsequent scleral icterus (66.7%). Six patients (66.7%) experienced a definite Valsalva manoeuvre prior to the onset. In acute phase, ultrasonography showed a low-to-medium reflective lesion without inside blood flow signal (mean thickness, 2.7±0.6 mm). Swept-source optical coherence tomography angiography (SS-OCTA) demonstrated the dilated vortex veins and ampulla with suprachoroidal haemorrhage and exudation. Indocyanine green angiography (ICGA) demonstrated choroidal circulation abnormalities in the affected quadrant. MRI showed a well-defined mass with enhancement. The main treatment was medical observation (44.5%). The choroidal pseudo-tumour spontaneously resolved with a mean course of 4.1±1.9 weeks. CONCLUSIONS: Acute vortex vein occlusion is a rare condition and initial misdiagnosis is not uncommon. It is mainly identified as an evanescent choroidal pseudo-tumour with acute pain, red eye and blurred vision. Widefield ICGA and SS-OCTA can offer valuable diagnostic clues. Medical observation may be a treatment option.

Semaphorin 3D promotes pancreatic ductal adenocarcinoma progression and metastasis through macrophage reprogramming.

Axon guidance molecules are frequently altered in pancreatic ductal adenocarcinoma (PDA) and influence PDA progression. However, the molecular mechanism remained unclear. Using genetically engineered mouse models to examine semaphorin 3D (SEMA3D), we identified a dual role for tumor- and nerve-derived SEMA3D in the malignant transformation of pancreatic epithelial cells and invasive PDA development. Pancreatic-specific knockout of the SEMA3D gene from the KRASG12D and TP53R172H mutation knock-in, PDX1-Cre(KPC) mouse model demonstrated delayed tumor initiation, prolonged survival, absence of metastasis, and reduced M2 macrophage expression. Mechanistically, tumor- and nerve-derived SEMA3D indirectly reprograms macrophages through KRASMUT-dependent ARF6 signaling in PDA cells, resulting in increased lactate production, which is sensed by GPCR132 on macrophages to stimulate protumorigenic M2 polarization. Multiplex immunohistochemistry demonstrated increased M2-polarized macrophages proximal to nerves in SEMA3D-expressing human PDA tissue. This study suggests that altered SEMA3D expression leads to an acquisition of cancer-promoting functions, and nerve-derived SEMA3D is "hijacked" by PDA cells to support growth and metastasis in a KRASMUT-dependent manner.

Preliminary proteomic analysis of human tears in lacrimal adenoid cystic carcinoma and pleomorphic adenoma.

AIM: To detect proteomic differences in tears between adenoid cystic carcinoma (ACC) and pleomorphic adenoma (PA). METHODS: Tear samples were collected from 4 patients with ACC, 5 with PA, and 4 control cases. Label-free analysis and parallel reaction monitoring (PRM) were used to screen and validate the tear proteome. Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) were conducted for bioinformatics analysis. RESULTS: In total, 1059 proteins in tear samples were identified by label-free analysis. Between ACC and PA, 415 differentially expressed proteins were detected. Based on the GO annotation, enzyme regulator activity and serine-type endopeptidase inhibitor activity in the molecular function category, blood microparticle and extracellular matrix in the cellular component category, and response to nutrient levels in the biological process category were most predominant. By KEGG pathway annotation, the different proteins between ACC and PA mainly participated in complement and coagulation cascades, amoebiasis, African trypanosomiasis and cholesterol metabolism. Eight proteins with mostly significant differences were verified by PRM, and five proteins with more than 10-fold increases in ACC compared with PA, including integrin ß, α-2-macroglobulin, epididymal secretory sperm binding protein Li 78p, RAB5C, and complement C5, were identified. CONCLUSION: The combined tools of label-free analysis and PRM are very effective and efficient, especially for samples such as tears. Some proteomic differences in tears between ACC and PA are identified and these protein candidates may be specific biomarkers for future exploration.

Tumor- and Nerve-Derived Axon Guidance Molecule Promotes Pancreatic Ductal Adenocarcinoma Progression and Metastasis through Macrophage Reprogramming.

Axon guidance molecules were found to be the gene family most frequently altered in pancreatic ductal adenocarcinoma (PDA) through mutations and copy number changes. However, the exact molecular mechanism regarding PDA development remained unclear. Using genetically engineered mouse models to examine one of the axon guidance molecules, semaphorin 3D (SEMA3D), we found a dual role for tumor-derived SEMA3D in malignant transformation of pancreatic epithelial cells and a role for nerve-derived SEMA3D in PDA development. This was demonstrated by the pancreatic-specific knockout of the SEMA3D gene from the KRAS G12D and TP53 R 172 H mutation knock-in, PDX1-Cre (KPC) mouse model which demonstrated a delayed tumor initiation and growth comparing to the original KPC mouse model. Our results showed that SEMA3D knockout skews the macrophages in the pancreas away from M2 polarization, providing a potential mechanistic role of tumor-derived SEMA3D in PDA development. The KPC mice with the SEMA3D knockout remained metastasis-free, however, died from primary tumor growth. We then tested the hypothesis that a potential compensation mechanism could result from SEMA3D which is naturally expressed by the intratumoral nerves. Our study further revealed that nerve-derived SEMA3D does not reprogram macrophages directly, but reprograms macrophages indirectly through ARF6 signaling and lactate production in PDA tumor cells. SEMA3D increases tumor-secreted lactate which is sensed by GPCR132 on macrophages and subsequently stimulates pro-tumorigenic M2 polarization in vivo. Tumor intrinsic- and extrinsic-SEMA3D induced ARF6 signaling through its receptor Plexin D1 in a mutant KRAS-dependent manner. Consistently, RNA sequencing database analysis revealed an association of higher KRAS MUT expression with an increase in SEMA3D and ARF6 expression in human PDAs. Moreover, multiplex immunohistochemistry analysis showed an increased number of M2-polarized macrophages proximal to nerves in human PDA tissue expressing SEMA3D. Thus, this study suggests altered expression of SEMA3D in tumor cells lead to acquisition of cancer-promoting functions and the axon guidance signaling originating from nerves is "hijacked" by tumor cells to support their growth. Other axon guidance and neuronal development molecules may play a similar dual role which is worth further investigation. One sentence summary: Tumor- and nerve-derived SEMA3D promotes tumor progression and metastasis through macrophage reprogramming in the tumor microenvironment. STATEMENT OF SIGNIFICANCE: This study established the dual role of axon guidance molecule, SEMA3D, in the malignant transformation of pancreatic epithelial cells and of nerve-derived SEMA3D in PDA progression and metastasis. It revealed macrophage reprogramming as the mechanism underlying bothroles. Together, this research elucidated how inflammatory responses promote invasive PDA progression and metastasis through an oncogenic process.

Pathological count of IgG4-positive plasmacytes suggests extraophthalmic involvement and relapse in patients with IgG4-related ophthalmic disease: a retrospective study.

BACKGROUND: IgG4-related ophthalmic disease (IgG4ROD) is a phenotype of IgG4-related disease (IgG4RD) with ophthalmic involvement. The pathological IgG4+ plasmacyte count has only been used for diagnosis. We aimed to explore its possible clinical value in the management of IgG4ROD. METHODS: Fifty-five pathologically diagnosed IgG4ROD patients were included, and their clinical, pathological, serological, and radiological findings and treatment outcomes were reviewed and analyzed. The pathological IgG4+ plasmacyte counts in lesions from different anatomic sites were compared, and their association with serum IgG4 concentrations, systemic involvement, and relapse risk was analyzed. RESULTS: The patients were divided into groups according to the anatomic site of their biopsied lesions, namely, the lacrimal gland, extraocular muscle, and orbital soft tissue. No significant difference was found in the pathological IgG4+ plasma cell counts among these groups (p = 0.975). The pathological IgG4+ plasmacyte count positively correlated with the IgG4 concentration in peripheral blood (R2 = 0.5469, p < 0.001). The serum IgG4 concentration and the pathological infiltrating IgG4+ plasmacyte count were significantly higher in patients with extraophthalmic involvement (p < 0.001 and p = 0.005, respectively). The areas under the receiver operating characteristic (ROC) curve (AUCs) of the serum IgG4 level and pathological IgG4+ plasmacyte count for identifying systemic involvement were 0.897 (p < 0.001) and 0.759 (p = 0.015), respectively. The patients with relapse had higher levels of serum IgG4, more germinal centers (GCs), and infiltrating IgG4+ plasmacytes in lesions. Multivariate Cox regression analysis revealed that a pathological IgG4+ plasmacyte count of > 150/high-power field (HPF) and an elevated serum IgG4 level of > 500 mg/dL were risk factors for relapse after steroid treatment. CONCLUSIONS: Lesions from different ophthalmic sites in IgG4ROD patients have similar counts of IgG4+ and IgG+ plasmacytes. The quantity of pathological IgG4+ plasmacytes corresponded to the serum IgG4 concentration in patients with IgG4ROD and could be meaningful in identifying systemic involvement and predicting subsequent relapse.

Lacrimal sac lymphoma: a case series and literature review.

AIM: To study the clinical and pathological characteristics of the lacrimal sac lymphoma, which is rare but it is the major type of non-epithelial malignant tumor in the lacrimal sac region. METHODS: Sixty-four cases of malignant lacrimal sac tumors in our hospital from 1986 to 2020 were retrospectively reviewed. Eight cases of lacrimal sac lymphoma were carefully reviewed. RESULTS: There were five mucosal-associated lymphoid tissue (MALT) lymphomas, one diffused large B-cell lymphoma, one NK/T cell lymphoma, and one mantle cell lymphoma. All eight patients represented symptoms of epiphora with swelling in the lacrimal sac for a certain period of time and showed no signs of systemic involvement at the first time of clinical visits. They had received either chemotherapy or radiotherapy after surgery. Long-term follow-up (from 11 to 220mo) showed that, except one patient with MALT lymphoma died for unknown reasons at 104mo after surgery, the other 7 patients were all alive with no signs of local recurrence, neither in other organs. CONCLUSION: Non-epithelial malignant tumors of the lacrimal sac are rare and lymphoma is the major subtype.

[Present status on studies of differentiation into retinal neurons and pigmented cell from induced pluripotent stem cells].

Somatic cells could be induced into pluripotent stem (iPS) cells through transferring special genes (Oct4, Sox2, c-myc and Klf4). This has brought a revolutionary change in stem cell study and application. The generation of iPS cells has great potential and enormous significance as it can resolve some insurmountable problems in stem cells research, such as ethical dilemma, immune rejection, etc. Because of these characteristics, it plays an important role in the repair of various tissues and organs. Rapid progress in this field during the past 3 years convinced us that iPS cells will be more and more applicable in tissue engineering. The present paper reviews the progress of pre-clinical study on iPS cells in the treatment of retinal and optic nerve diseases.

[Changes of neuroglia cells in human glaucoma and animal model of experimental glaucoma].

Glaucoma is one of the major ocular diseases that lead to blindness. It is characterized by optic disk cupping and visual field loss. Glaucoma is a multifactorial group of diseases with many different causes but one common endpoint, progressive loss of retinal ganglion cells. Hence most studies of glaucoma focused on retinal ganglion cells and their nosogenesis. But recent studies have showed that neuroglia cells, as another major kind of cells of nerve system, also undergo an activation process in glaucoma. Their activation is closely connected with the changes of retinal ganglion cells as well as the development of the disease. Therefore, more and more attention is focused on the changes of these cells. This review is a summary about the recent studies on the pathological changes of these four different kinds of neuroglia cells in human glaucoma and in several animal models of experimental glaucoma.

Calpastatin participates in the regulation of cell migration in BAP1-deficient uveal melanoma cells.

AIM: To detect how BRCA-associated protein 1 (BAP1) regulates cell migration in uveal melanoma (UM) cells. METHODS: Wound healing and transwell assays were performed to detect UM cell migration abilities. Protein chip, immunoprecipitations and surface plasmon resonance analyses were applied to identify BAP1 protein partners. Western blot and calpain activity assays were used to test the expression and function of calpastatin (CAST). RESULTS: CAST protein was confirmed as a new BAP1 protein partner, and loss of BAP1 reduced the expression and function of CAST in UM cells. The overexpression of CAST rescued the cell migration phenotype caused by BAP1 loss. CONCLUSION: BAP1 interacts with CAST in UM cells, and CAST and its subsequent calpain pathway may mediate BAP1-related cell migration regulation.

In Vivo Detection and Analysis of Rb Protein SUMOylation in Human Cells.

The post-translational modifications of proteins are critical for the proper regulation of intracellular signal transduction. Among these modifications, small ubiquitin-related modifier (SUMO) is a ubiquitin-like protein that is covalently attached to the lysine residues of a variety of target proteins to regulate cellular processes, such as gene transcription, DNA repair, protein interaction and degradation, subcellular transport, and signal transduction. The most common approach to detecting protein SUMOylation is based on the expression and purification of recombinant tagged proteins in bacteria, allowing for an in vitro biochemical reaction which is simple and suitable for addressing mechanistic questions. However, due to the complexity of the process of SUMOylation in vivo, it is more challenging to detect and analyze protein SUMOylation in cells, especially when under endogenous conditions. A recent study by the authors of this paper revealed that endogenous retinoblastoma (Rb) protein, a tumor suppressor that is vital to the negative regulation of the cell cycle progression, is specifically SUMOylated at the early G1 phase. This paper describes a protocol for the detection and analysis of Rb SUMOylation under both endogenous and exogenous conditions in human cells. This protocol is appropriate for the phenotypical and functional investigation of the SUMO-modification of Rb, as well as many other SUMO-targeted proteins, in human cells.

Human-specific CHRFAM7A protects against radiotherapy-induced lacrimal gland injury by inhibiting the p38/JNK signalling pathway and oxidative stress.

Radiotherapy-induced lacrimal gland injury often causes dry eye. Oxidative stress and local inflammation are the primary consequences of radiotherapy-induced injury. The most recent research shows that the human-specific gene CHRFAM7A plays an important role in inflammation. However, the effect of CHRFAM7A on radiotherapy-induced lacrimal gland injury remains unclear. In this study, humanized mice were successfully generated via the transplantation of human peripheral blood mononuclear cells that expressed human-specific genes. After radiation, the CHRFAM7A gene was highly expressed in the lacrimal glands of humanized mice, in which it protected the function of the lacrimal gland after radiotherapy. CHRFAM7A down-regulated radiotherapy-induced inflammation by suppressing p38/JNK signalling. CHRFAM7A also inhibited oxidative stress in the haematopoietic system after radiotherapy. Further signalling pathway analyses indicated that CHRFAM7A suppressed Akt (protein kinase B, PKB) phosphorylation. CHRFAM7A may therefore be a therapeutic target in radiation-induced lacrimal gland injury.

Clinicopathological Characteristics and Prognosis for Survival after Enucleation of Uveal Melanoma in Chinese Patients: Long-term Follow-up.

PURPOSE: To summarize the clinicopathological characteristics and prognosis of uveal melanoma (UM) after enucleation in Chinese patients. METHODS: Between 2003 and 2012, a series of 171 patients with UM received enucleation at the Eye & ENT Hospital of Fudan University in Shanghai. Patient clinical information was collected. Pathological examination and BAP1 staining of the enucleated eyes were conducted. Univariate and multivariate Cox proportional hazard regressions were conducted to determine the risk factors, and the survival rates were calculated and compared. RESULTS: The study included 83 (49%) men and 88 (51%) women, with a mean age of 48.6 years. The mean largest basal tumor diameter and mean largest tumor thickness were 11.8 and 8.6 mm, respectively. Ciliary body involvement was observed in 19 tumors (11%). Spindle and nonspindle patterns were observed in 100 (58%) and 71 eyes (42%), respectively. Extrascleral extension was observed in three eyes (2%). BAP1 staining was negative in 34% (53/156) of all tumors and 53% (19/36) of the cases with melanoma-related metastasis. The mean follow-up period was 63.4 months for all patients with the exception of 11 patients, who were excluded because they were lost during follow-up. A large basal tumor diameter, ciliary body involvement, nonspindle cell type, extrascleral extension, and negative BAP1 staining were associated with a worse prognosis. The survival curves significantly differed between the BAP1-negative and BAP1-positive groups (P = 0.004). According to Kaplan-Meier analysis, the 5- and 10-year metastasis-free survival rates were 80% and 70%, respectively. CONCLUSIONS: A large basal tumor diameter, ciliary body involvement, nonspindle cell type, extrascleral extension, and negative BAP1 staining may be risk factors for the prediction of the UM prognosis. A younger age at diagnosis and a similar prognosis between genders may be unique features in Asian patients compared to the Caucasian population.

SUMOylation of Rb enhances its binding with CDK2 and phosphorylation at early G1 phase.

Retinoblastoma protein (Rb) is a prototypical tumor suppressor that is vital to the negative regulation of the cell cycle and tumor progression. Hypo-phosphorylated Rb is associated with G0/G1 arrest by suppressing E2F transcription factor activity, whereas Rb hyper-phosphorylation allows E2F release and cell cycle progression from G0/G1 to S phase. However, the factors that regulate cyclin-dependent protein kinase (CDK)-dependent hyper-phosphorylation of Rb during the cell cycle remain obscure. In this study, we show that throughout the cell cycle, Rb is specifically small ubiquitin-like modifier (SUMO)ylated at early G1 phase. SUMOylation of Rb stimulates its phosphorylation level by recruiting a SUMO-interaction motif (SIM)-containing kinase CDK2, leading to Rb hyper-phosphorylation and E2F-1 release. In contrast, a SUMO-deficient Rb mutant results in reduced SUMOylation and phosphorylation, weakened CDK2 binding, and attenuated E2F-1 sequestration. Furthermore, we reveal that Rb SUMOylation is required for cell proliferation. Therefore, our study describes a novel mechanism that regulates Rb phosphorylation during cell cycle progression.