The biology and management of uveal melanoma

Laparoscopic distal pancreatectomy for metastatic melanoma originating from the choroidal membrane: a case report

Background

Metastatic melanoma originating from the choroidal membrane is extremely rare. Here, we report a case of laparoscopic distal pancreatectomy for malignant melanoma that developed after heavy-particle therapy for malignant choroidal melanoma.

Case presentation

A 43-year-old Japanese woman underwent 70 Gy heavy-particle radiotherapy for a right choroidal malignant melanoma. Positron emission tomography-computed tomography examination was performed 4 years after treatment, when contrast accumulation was observed on the posterior wall of the stomach. Endoscopic ultrasonography and computed tomography showed a mass with contrast enhancement in contact with the stomach wall. Based on the imaging findings, a gastrointestinal stromal tumor of the posterior wall of the lower gastric corpus with extramural growth was suspected. Laparoscopic surgery was performed under general anesthesia. A black-pigmented tumor originating from the pancreas was discovered. Following an intraoperative diagnosis of metastasis of malignant melanoma, a laparoscopic distal pancreatectomy was performed. The pathological diagnosis was pancreatic metastasis of malignant melanoma. The patient was treated with adjuvant immune checkpoint inhibitors and chemotherapy after surgery, which led to long-term survival.

Conclusions

Including this case, only eight case reports on pancreatic resection for metastatic ocular malignant melanoma have been reported. The ocular malignant melanoma with distant metastasis has a poor prognosis. Therefore, in our case, careful follow-up is required. A single pancreatic metastasis from a malignant melanoma of the choroid can be successfully managed by laparoscopic radical resection of the pancreas, and molecularly targeted adjuvant chemotherapy.

The Role of HGF/MET Signaling in Metastatic Uveal Melanoma

Simple Summary

Hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (MET) signaling plays an important role in the metastatic formation and therapeutic resistance to uveal melanoma. Here, we review the various functions of MET signaling contributing to metastatic formation, as well as review resistance to treatments in metastatic uveal melanoma.

Abstract

Hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (MET) signaling promotes tumorigenesis and tumor progression in various types of cancer, including uveal melanoma (UM). The roles of HGF/MET signaling have been studied in cell survival, proliferation, cell motility, and migration. Furthermore, HGF/MET signaling has emerged as a critical player not only in the tumor itself but also in the tumor microenvironment. Expression of MET is frequently observed in metastatic uveal melanoma and is associated with poor prognosis. It has been reported that HGF/MET signaling pathway activation is the major mechanism of treatment resistance in metastatic UM (MUM). To achieve maximal therapeutic benefit in MUM patients, it is important to understand how MET signaling drives cellular functions in uveal melanoma cells. Here, we review the HGF/MET signaling biology and the role of HGF/MET blockades in uveal melanoma.

Molecular Insights and Emerging Strategies for Treatment of Metastatic Uveal Melanoma

Uveal melanoma (UM) is the most common intraocular cancer. In recent decades, major advances have been achieved in the diagnosis and prognosis of UM allowing for tailored treatments. However, nearly 50% of patients still develop metastatic disease with survival rates of less than 1 year. There is currently no standard of adjuvant and metastatic treatment in UM, and available therapies are ineffective resulting from cutaneous melanoma protocols. Advances and novel treatment options including liver-directed therapies, immunotherapy, and targeted-therapy have been investigated in UM-dedicated clinical trials on single compounds or combinational therapies, with promising results. Therapies aimed at prolonging or targeting metastatic tumor dormancy provided encouraging results in other cancers, and need to be explored in UM. In this review, the latest progress in the diagnosis, prognosis, and treatment of UM in adjuvant and metastatic settings are discussed. In addition, novel insights into tumor genetics, biology and immunology, and the mechanisms underlying metastatic dormancy are discussed. As evident from the numerous studies discussed in this review, the increasing knowledge of this disease and the promising results from testing of novel individualized therapies could offer future perspectives for translating in clinical use.

PARP Inhibition Increases the Response to Chemotherapy in Uveal Melanoma

Uveal melanoma (UM) remains without effective therapy at the metastatic stage, which is associated with BAP-1 (BRCA1 associated protein) mutations. However, no data on DNA repair capacities in UM are available. Here, we use UM patient-derived xenografts (PDXs) to study the therapeutic activity of the PARP inhibitor olaparib, alone or in combination. First, we show that the expression and the activity of PARP proteins is similar between the PDXs and the corresponding patient’s tumors. In vivo experiments in the PDX models showed that olaparib was not efficient alone, but significantly increased the efficacy of dacarbazine. Finally, using reverse phase protein arrays and immunohistochemistry, we identified proteins involved in DNA repair and apoptosis as potential biomarkers predicting response to the combination of olaparib and dacarbazine. We also observed a high increase of phosphorylated YAP and TAZ proteins after dacarbazine + olaparib treatment. Our results suggest that PARP inhibition in combination with the alkylating agent dacarbazine could be of clinical interest for UM treatment. We also observe an interesting effect of dacarbazine on the Hippo pathway, confirming the importance of this pathway in UM.

Adjuvant Ipilimumab in High-Risk Uveal Melanoma

Uveal melanoma is a common intraocular malignant tumor that is uniformly fatal once metastatic. No effective adjuvant therapy currently exists to reduce the risk of distant metastasis after definitive treatment of the primary lesion. Immunotherapy has been used effectively in the adjuvant setting in locally advanced cutaneous melanoma. We performed a Phase I/II clinical trial of adjuvant ipilimumab in high-risk primary uveal melanoma with distant metastasis-free survival (DMFS) as the primary objective. A total of 10 patients with genomically high-risk disease were treated: three at a dose of 3 mg/kg and seven at 10 mg/kg. Two of the seven patients at the higher dose had to discontinue therapy secondary to grade 3 toxicity. At 36 months follow-up, 80% of patients had no evidence of distant disease (95% CI, 58.7–100). With recent advancements in CTLA-4 inhibition, PD-1 inhibition, and combined checkpoint blockade, immunotherapy is a promising avenue of treatment in uveal melanoma. Further clinical trials are needed to elucidate the role of immunotherapy in the adjuvant setting.

Reprogramming Cells for Synergistic Combination Therapy with Nanotherapeutics against Uveal Melanoma

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults and around half of the patients develop metastasis and die shortly after because of the lack of effective therapies for metastatic UM. Consequently, new therapeutic approaches to this disease are welcome. In this regard, microRNAs have been shown to have a key role in neoplasia progression and have the potential to be used as therapeutic tools. In addition, in different cancers including UM, a particular microRNA signature appears that is different from healthy cells. Thus, restoring the regular levels of microRNAs could restore the normal behavior of cells. In this study, four microRNAs downregulated in UM have been chosen to reprogram cancer cells, to promote cell death or increase their sensitivity to the chemotherapeutic SN38. Furthermore, to improve the internalization, stability and/or solubility of the therapeutic molecules employed in this approach, gold nanoparticles (AuNPs) were used as carriers. Remarkably, this study found a synergistic effect when the four oligonucleotides were employed and when the chemotherapeutic drug was added.

Somatostatin Receptors as Molecular Targets in Human Uveal Melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults, with an incidence of 4–5 cases per million. The prognosis of UM is very poor. In the present study, our aim was to investigate the expression of mRNA and protein for somatostatin receptor types-1, -2, -3, -4, -5 (SSTR-1–5) in human UM tissue samples and in OCM-1 and OCM-3 human UM cell lines by qRT-PCR, western blot and ligand competition assay. The mRNA for SSTR-2 showed markedly higher expression in UM tissues than SSTR-5. The presence of SSTRs was demonstrated in 70% of UM specimens using ligand competition assay and both human UM models displayed specific high affinity SSTRs. Among the five SSTRs, the mRNA investigated for SSTR-2 and SSTR-5 receptors was strongly expressed in both human UM cell lines, SSTR-5 showing the highest expression. The presence of the SSTR-2 and SSTR-5 receptor proteins was confirmed in both cell lines by western blot. In summary, the expression of somatostatin receptors in human UM specimens and in OCM-1 and OCM-3 human UM cell lines suggests that they could serve as a potential molecular target for therapy of UM using modern powerful cytotoxic SST analogs targeting SSTR-2 and SSTR-5 receptors.

Robot-assisted laparoscopic surgery for abdominal metastatic melanoma mimicking a gastrointestinal stromal tumor: A case report and review of the literature

RATIONALE

Uveal melanoma is the most common primary intraocular malignancy, which could metastasize at an early stage of the disease and associated with poor prognoses. Liver, small bowel, stomach, and colon are the most common locations for metastatic visceral melanoma, however, solitary abdominal metastasis from uveal melanoma is extremely rare.

PATIENT CONCERNS

The current study reports the case of a 33-year-old man with history of treated choroidal melanoma of the left eye that developed metastasis to the abdomen, preoperative endoscopic ultrasonography and computed tomography strongly suggested as a gastrointestinal stromal tumor (GIST).

DIAGNOSES

The patient was diagnosed with abdominal metastatic melanoma according to his medical history and histopathological results.

INTERVENTIONS

The young adult underwent robot-assisted laparoscopic surgery.

OUTCOMES

The patient finally got the definite diagnosis with his medical history and histopathological results and he has been living disease free for nearly 3 years after the surgery.

LESSONS

Although rare, the possibility of abdominal metastatic melanoma presenting with the clinical picture of gastrointestinal stromal tumor must be always considered by the surgeon especially the patients with a history of primary malignant melanoma.

Targeted silencing of the ADP-ribosyltransferase 3 gene inhibits the migration ability of melanoma cells

Melanoma is the most common primary intraocular malignancy and metastasis of melanoma to other organs often results in a poor prognosis. ADP-ribosyltransferase 3 (ART3) is involved in cell division and DNA repair. However, its biological function in melanoma remains unclear. In the present study, it was identified that ART3 is highly expressed in melanoma cells and melanoma tissues compared with the normal RPE cell line, and adjacent normal tissue, respectively. Small interfering RNA and short hairpin RNA were used to silence ART3 gene expression, and the results revealed that the silencing of ART3 inhibits the migratory ability of melanoma cells. The present study indicates that ART3 serves a notable role in the metastasis of melanoma and provides a potential therapeutic target for this disease.

Long non-coding RNA FTH1P3 facilitates uveal melanoma cell growth and invasion through miR-224-5p

Growing evidences indicated that Long noncoding RNAs (lncRNAs) played important roles in tumor initiation and progression. However, the function and mechnism of lncRNA ferritin heavy chain 1 pseudogene 3 (FTH1P3) remain unknown in uveal melanoma. We showed that the expression level of FTH1P3 was upregulated in uveal melanoma cell lines and tissues. Elevated expression of FTH1P3 promoted uveal melanoma cell proliferation, cell cycle and migration. Moreover, we found that FTH1P3 was a direct target gene of miR-224-5p in uveal melanoma cell. Overexpression of FTH1P3 suppressed miR-224-5p expression and promoted the expression of Rac1 and Fizzled 5, which were the direct target genes of miR-224-5p. Furthermore, we showed that miR-224-5p expression level was downregulated in uveal melanoma cell lines and tissues. FTH1P3 expression was inversely correlated with the miR-224-5p expression in uveal melanoma tissues. Ectopic expression of miR-224-5p decreased uveal melanoma cell proliferation, cell cycle and migration. Elevated expression of FTH1P3 enhanced uveal melanoma cell proliferation and migration by inhibiting miR-224-5p expression. These results suggest that lncRNA FTH1P3 plays a crucial role in uveal melanoma. Investigation of the underlying mechanism may be a target for the treatment of uveal melanoma.

Evaluation of p53 gene expression and prognosis characteristics in uveal melanoma cases

Objective

The objective of this study was to evaluate the correlation between the expression of p53 gene and the prognosis after local excision in uveal melanoma.

Materials and methods

Real-time polymerase chain reaction (RT-PCR) test and Western blot were used to detect the expression of p53 in C918, MUM-2B, and D78 cell lines at the levels of messenger RNA (mRNA) and protein. Immunohistochemistry staining was done in the tissues of 68 patients, which were diagnosed with uveal melanoma. Furthermore, the effects of p53 protein on the invasion abilities of both the cell lines were studied by transinfection of p53 small interfering RNA. The clinical and prognostic data regarding the effect of p53 protein on the patient’s prognosis were calculated and further analyzed by Kaplan–Meier univariate analysis method.

Results

The results of RT-PCR and Western blot revealed that p53 mRNAs were highly expressed in C918 and MUM-2B cells. The high expression rate of p53 among the 88 uveal melanoma tissues was 77.27%. Transinfection of p53 serine could inhibit the expression of p53 in uveal melanoma and the invasion ability of the cells. This study found that the high expression of p53 and the prognosis of uveal melanoma patients were statistically correlated.

Conclusion

The expression of p53 protein in uveal melanoma was unusual and was associated with the invasion ability of uveal melanoma. This indicates that the highest expression of p53 protein indicates worse prognosis of uveal melanoma patients.

Uveal melanoma: epidemiology, etiology, and treatment of primary disease

Uveal melanoma (UM) is the most common intraocular malignancy and arises from melanocytes in the iris, ciliary body, or choroid. Early diagnosis and local treatment is crucial, as survival correlates with primary tumor size. However, approximately 50% of patients will develop metastatic disease with 6-12 months' survival from metastatic diagnosis. Genomic analyses have led to the development of gene-expression profiles that effectively predict metastatic progression; unfortunately, no adjuvant therapy has been shown to prolong survival to date. New insights into the molecular biology of UM have found frequent activating mutations in genes encoding for the G-protein α-subunit, GNAQ and GNA11, and improved understanding of the downstream signaling pathways MAPK, PI3K/Akt, and Hippo have afforded an array of new targets for treatment of this disease. Studies are under way with rationally developed regimens targeting these pathways, and novel agents are under development. We review the diagnosis, management, and surveillance of primary UM and the adjuvant therapy trials under way.

Immunotherapy for uveal melanoma

Uveal melanoma (UM) is a rare cancer with a high mortality rate. In comparison to cutaneous melanoma, UM has unique immunological features. Arising in the immune suppressive environment of the eye, it maintains immune resistance once metastatic. This is considered a major obstacle for successful immunotherapy in UM. However, a growing body of evidence suggests strategies that may abrogate resistance and enhance antitumor immunity in UM. Recently, three new immune agents have been approved for melanoma. While these drugs demonstrate durable clinical responses with long-term remissions in metastatic cutaneous melanoma, only limited data exist in metastatic UM. In this review, immunological aspects of UM and data from clinical studies of immunotherapeutic agents and regimens for UM will be discussed.

Establishment and Characterization of Orthotopic Mouse Models for Human Uveal Melanoma Hepatic Colonization

Uveal melanoma (UM) is a rare type of melanoma, although it is the most common primary ocular malignant tumor in adults. Nearly one-half the patients with primary UM subsequently develop systemic metastasis, preferentially to the liver. Currently, no treatment is effective for UM hepatic metastasis, and the prognosis is universally poor. The main challenge in designing a treatment strategy for UM hepatic metastasis is the lack of suitable animal models. We developed two orthotopic mouse models for human UM hepatic metastases: direct hepatic implantation model (intrahepatic dissemination model) and splenic-implantation model (hematogenous dissemination model) and investigated the tumorgenesis in the liver. A human UM cell line, established from a hepatic metastasis and nonobese diabetic severe combined immunodeficient γ mice, were used for development of in vivo tumor models. In the direct hepatic implantation model, a localized tumor developed in the liver in all cases and intrahepatic dissemination was subsequently seen in about one-half of cases. However, in the splenic implantation model, multiple hepatic metastases were observed after splenic implantation. Hepatic tumors subsequently seeded intra-abdominal metastasis; however, lung metastases were not seen. These findings are consistent with those observed in human UM hepatic metastases. These orthotopic mouse models offer useful tools to investigate the biological behavior of human UM cells in the liver.

MicroRNA-454 functions as an oncogene by regulating PTEN in uveal melanoma

MicroRNAs (miRNAs) regulate gene expression by targeted repression of transcription and translation, and are involved in carcinogenesis. In this study, we demonstrated that the expression of miR-454 was up-regulated in uveal melanoma tissues compared to normal tissues. Ectopic expression of miR-454 resulted in significant promotion of cell proliferation, colony formation, invasion and induction of cell cycle in uveal melanoma cells. Furthermore, we identified PTEN as a direct target of miR-454. Our data revealed that ectopic expression of PTEN restored the effects of miR-454 on cell proliferation and invasion in uveal melanoma cells. These findings support an oncogene role of miR-454 in development of uveal melanoma.

MiR-144 Inhibits Uveal Melanoma Cell Proliferation and Invasion by Regulating c-Met Expression

MicroRNAs (miRNAs) are a group endogenous small non-coding RNAs that inhibit protein translation through binding to specific target mRNAs. Recent studies have demonstrated that miRNAs are implicated in the development of cancer. However, the role of miR-144 in uveal melanoma metastasis remains largely unknown. MiR-144 was downregulated in both uveal melanoma cells and tissues. Transfection of miR-144 mimic into uveal melanoma cells led to a decrease in cell growth and invasion. After identification of two putative miR-144 binding sites within the 3' UTR of the human c-Met mRNA, miR-144 was proved to inhibit the luciferase activity inMUM-2B cells with a luciferase reporter construct containing the binding sites. In addition, the expression of c-Met protein was inhibited by miR-144. Furthermore, c-Met-mediated cell proliferation and invasion were inhibited by restoration of miR-144 in uveal melanoma cells. In conclusion, miR-144 acts as a tumor suppressor in uveal melanoma, through inhibiting cell proliferation and migration. miR-144 might serve as a potential therapeutic target in uveal melanoma patients.

Double-blinded, randomized phase II study using embolization with or without granulocyte-macrophage colony-stimulating factor in uveal melanoma with hepatic metastases

PURPOSE

To investigate the effects of immunoembolization with granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with uveal melanoma (UM) with liver-only metastasis.

MATERIALS AND METHODS

In this double-blind phase II clinical trial, patients were randomized to undergo immunoembolization or bland embolization (BE). Lobar treatment was performed with GM-CSF or normal saline solution mixed with ethiodized oil followed by embolization with gelatin sponge emulsified with iodinated contrast medium. Fifty-two patients (immunoembolization, n = 25; BE, n = 27) were enrolled. Response was assessed after every two treatments. The primary endpoint was overall response rate (ORR) of liver metastases. Progression-free survival (PFS), overall survival (OS), and immunologic responses were secondary endpoints.

RESULTS

There were five partial responses in the immunoembolization group (ORR, 21.2%; 90% confidence interval [CI], 10.3%-30.5%) and three in the BE group (ORR, 16.7%; 90% CI, 6.3%-26.9%). Stable disease was seen in 12 patients in the immunoembolization group and 19 in the BE group. OS times were 21.5 months (95% CI, 18.5-24.8 mo) with immunoembolization and 17.2 months (95% CI, 11.9-22.4 mo) with BE. The degree of proinflammatory cytokine production was more robust after immunoembolization and correlated with time to "systemic" extrahepatic progression. In the immunoembolization group, interleukin (IL)-6 levels at 1 hour (P = .001) and IL-8 levels at 18 hours after the procedure (P < .001) were significant predictors of longer systemic PFS. Moreover, a dose-response pattern was evident between posttreatment serum cytokine concentrations and systemic PFS.

CONCLUSIONS

Immunoembolization induced more robust inflammatory responses, which correlated with the delayed progression of extrahepatic systemic metastases.

Epigenetics and ocular diseases: from basic biology to clinical study

Epigenetics is an emerging field in ophthalmology and has opened a new avenue for understanding ocular development and ocular diseases related to aging and environment. Epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and deployment of non-coding RNAs, result in the heritable silencing of gene expression without any change in DNA sequence. Accumulating evidence suggests a potential link between gene expression, chromatin structure, non-coding RNAs, and cellular differentiation during ocular development. Disruption of the balance of epigenetic networks could become the etiology of several ocular diseases. Here, we summarized the current knowledge about epigenetic regulatory mechanisms in ocular development and diseases.

Uveal melanoma: evaluation of extrascleral extension using thin-section MR of the eye with surface coils

PURPOSE

This study was done to evaluate the role of high-resolution magnetic resonance (MR) imaging with special surface coils in selecting the correct therapeutic approach (eye enucleation or follow-up) in patients with suspected extrascleral extension of uveal melanoma.

MATERIALS AND METHODS

This prospective study involved 12 patients with suspected extrascleral extension of uveal melanoma on orbital ultrasonography. All patients were studied with thin-section MR imaging of the eye using surface coils.

RESULTS

High-resolution MR imaging of the eye excluded extrascleral extension of disease in 8/12 patients: in 4/8 cases it revealed vascular ectasia and in the other 4/8 cases the linear hypointensity of the sclera was unbroken. Seven of these eight patients were followed up by ultrasound, which showed stability of melanoma for at least 2 years, while the last patient underwent enucleation, and the histological examination confirmed the MR diagnosis. In 4/12 patients, high-resolution MR suggested a diagnosis of extrascleral extension of melanoma, which was confirmed at histological examination after enucleation.

CONCLUSION

High-resolution MR imaging of the eye with surface coils allowed us to evaluate extrascleral extension of uveal melanoma and choose the correct therapeutic approach, avoiding unnecessary enucleation in 7/12 patients.

Expression of insulin-like growth factor-1 receptor in metastatic uveal melanoma and implications for potential autocrine and paracrine tumor cell growth

We investigated the importance of the insulin-like growth factor-1 receptor (IGF-1R) in hepatic metastases of uveal melanoma. The expression pattern of IGF-1R in archival tissue samples of hepatic metastasis from 24 patients was analyzed by immunohistochemistry. All the samples of hepatic metastases stained positive for IGF-1R. To investigate the biological role of IGF-1R on the growth of metastatic uveal melanoma, a long-term cell line obtained from a hepatic metastasis (TJU-UM001) was evaluated. TJU-UM001 expressed cell surface IGF-1R (>90%) and proliferated in response to exogenous and endogenous insulin-like growth factor-1 (IGF-1). Correlatively, anti-IGF-1R antibody completely blocked IGF-1-induced growth of TJU-UM001 cells. IGF-1 preferentially induced phosphorylation of Akt (S473) in quiescent TJU-UM001 cells, and this was blocked by anti-IGF-1R antibody. This study suggests that autocrine and paracrine mechanisms underlie IGF-1-induced growth of metastatic uveal melanoma and underscore the potential benefit of IGF-1 or IGF-1R antagonism in treatment for metastatic uveal melanoma.

Host pigment epithelium-derived factor (PEDF) prevents progression of liver metastasis in a mouse model of uveal melanoma

Uveal melanoma (UM) has a 30 % 5-year mortality rate, primarily due to liver metastasis. Both angiogenesis and stromagenesis are important mechanisms for the progression of liver metastasis. Pigment epithelium-derived factor (PEDF), an anti-angiogenic and anti-stromagenic protein, is produced by hepatocytes. Exogenous PEDF suppresses metastasis progression; however, the effects of host-produced PEDF on metastasis progression are unknown. We hypothesize that host PEDF inhibits liver metastasis progression through a mechanism involving angiogenesis and stromagenesis. Mouse melanoma cells were injected into the posterior ocular compartment of PEDF-null mice and control mice. After 1 month, the number, size, and mean vascular density (MVD) of liver metastases were determined. The stromal component of hepatic stellate cells (HSCs) and the type III collagen they produce was evaluated by immunohistochemistry. Host PEDF inhibited the total area of liver metastasis and the frequency of macrometastases (diameter >200 μm) but did not affect the total number of metastases. Mice expressing PEDF exhibited significantly lower MVD and less type III collagen production in metastases. An increase in activated HSCs was seen in the absence of PEDF, but this result was not statistically significant. In conclusion, host PEDF inhibits the progression of hepatic metastases in a mouse model of UM, and loss of PEDF is accompanied by an increase in tumor blood vessel density and type III collagen.

Somatostatin receptor scintigraphy in patients with metastatic uveal melanoma

As uveal melanoma originates in the neural crest, we aimed to explore whether somatostatin receptor (SSTR) expression is present and plays any role in these patients. Heavily pretreated metastatic uveal melanoma patients were tested with somatostatin receptor scintigraphy (SRS). Planar images of the whole body complemented by single-photon emission computed tomography on suspected sites were acquired between 4 and 24 h after an intravenous administration of 185-222 MBq (5-6 mCi) of indium-octeotride. SSTR expression in metastatic tissues was confirmed by immunohistochemistry. In seven patients, sandostatin LAR was used with therapeutic intention. Thirty white patients were tested. All had extensive metastatic disease and the median number of previous treatments was three. SRS was found to be positive in 14 (46%) of the patients, but was not related to sex, type of previous treatments, tumor site, or histological type. In 10 patients, sufficient tumor specimens were available to perform immunohistochemical staining for SSTR. All cases with positive SSTR-2A staining were also positive by SRS. Two of the seven patients who received sandostatin LAR died within a month after receiving the first dose, whereas another two (28.5%) had stable disease for more than 5 months. The median time to progression after starting sandostatin was 2.1 months (range: 0.2-5.5 months). Approximately 50% of the uveal melanoma patients with extensive metastatic disease were positive for SSR, which was consistent with immunohistochemical staining for SSTR-2A. Therapeutic approaches targeting SSTR might be beneficial in patients with metastatic uveal melanoma.

Occupational cooking and risk of uveal melanoma: a meta-analysis

BACKGROUND

Many observational studies have assessed the possible association between occupational cooking and uveal melanoma risk, but reported results are controversial. Our goal was to evaluate the association between occupational cooking and uveal melanoma risk by conducting a meta-analysis of observational studies.

METHODS

PubMed, EMBASE, and Web of Science were searched through June 2012 to identify all eligible studies. The pooled odds ratio (OR) with its 95% confidence interval (95%CI) was used to evaluate this association. Either a fixed- or a random-effects model were used to calculate pooled ORs.

RESULTS

Five case-control studies involving a total of 1,199 cases and 6,927 controls were included in the meta-analysis. Overall, occupational cooking was associated with an increased risk of uveal melanoma (OR: 1.81, 95%CI 1.33-2.46, P < 0.001). Subgroup analysis by gender suggested occupational cooking was associated with increased risk of uveal melanoma in both men (OR: 2.16, 95%CI 1.06-4.40, P = 0.034) and women (OR: 1.92, 95%CI 1.19-3.10, P = 0.008).

CONCLUSION

This meta-analysis suggests that occupational cooking is associated with an increased risk of uveal melanoma in both men and women.

p63 is an alternative p53 repressor in melanoma that confers chemoresistance and a poor prognosis

p63 is up-regulated in melanoma and prevents nuclear accumulation of p53.

The role of apoptosis in melanoma pathogenesis and chemoresistance is poorly characterized. Mutations in TP53 occur infrequently, yet the TP53 apoptotic pathway is often abrogated. This may result from alterations in TP53 family members, including the TP53 homologue TP63. Here we demonstrate that TP63 has an antiapoptotic role in melanoma and is responsible for mediating chemoresistance. Although p63 was not expressed in primary melanocytes, up-regulation of p63 mRNA and protein was observed in melanoma cell lines and clinical samples, providing the first evidence of significant p63 expression in this lineage. Upon genotoxic stress, endogenous p63 isoforms were stabilized in both nuclear and mitochondrial subcellular compartments. Our data provide evidence of a physiological interaction between p63 with p53 whereby translocation of p63 to the mitochondria occurred through a codependent process with p53, whereas accumulation of p53 in the nucleus was prevented by p63. Using RNA interference technology, both isoforms of p63 (TA and ΔNp63) were demonstrated to confer chemoresistance, revealing a novel oncogenic role for p63 in melanoma cells. Furthermore, expression of p63 in both primary and metastatic melanoma clinical samples significantly correlated with melanoma-specific deaths in these patients. Ultimately, these observations provide a possible explanation for abrogation of the p53-mediated apoptotic pathway in melanoma, implicating novel approaches aimed at sensitizing melanoma to therapeutic agents.

Eyes on DNA methylation: current evidence for DNA methylation in ocular development and disease

Epigenetic modulation of chromatin states constitutes a vital component of the cellular repertoire of transcriptional regulatory mechanisms. The development of new technologies capable of generating genome-wide maps of chromatin modifications has re-energized the field. We are now poised to determine how species- and tissue-specific patterns of DNA methylation, in concert with other chromatin modifications, function to establish and maintain cell- and tissue-specific patterns of gene expression during normal development, cellular differentiation, and disease. This review addresses our current understanding of the major mechanisms and function of DNA methylation in vertebrates with a historical perspective and an emphasis on what is known about DNA methylation in eye development and disease.

[Genomic techniques used in uveal melanoma: a literature review]

Genome study and expression profiling of the tumor seem to be the most significant biologic prognostic factor in uveal melanoma. Many cytogenetic and molecular tests are reported; our aim was to assess their ability to detect high metastatic risk patients through a literature review. Standard karyotyping, fluorescence in situ hybridization and microsatellite analysis are not adequate. DNA-based genome techniques must analyse the entire genome (comparative genomic hybridization [CGH]) and, optimally, detect chromosome 3 isodisomy ("single-nucleotid polymorphism" SNP-array). Multiplex ligation-dependent probe amplification (MLPA) is less expensive than array-CGH, but its interpretation may be delicate. Gene expression profiling is the most accurate molecular test for predicting metastatic death in patient with uveal melanoma even if it remains a costly technique. These prognostic tests could be useful to identify high-risk patients in future adjuvant therapy protocols.

Expression of connexin 43 and E-cadherin in choroidal melanoma

AIM

To investigate the expression of connexin 43 and epithelial cadherin (E-cadherin) in choroidal melanoma, to explore the clinical and pathological implications of expression of these proteins, and to determine their relations with malignant features.

METHODS

The expression of connexin 43 and E-cadherin in choroidal melanoma were detected by immunohistochemistry and correlated with clinicopathological features.

RESULTS

Positive rates of connexin 43 in choroidal melanomas and benign pigmented nevus tissues were 75% and 40% respectively with significant differences between the two groups (χ(2)=5.607, P=0.009). Positive rates of E-cadherin in choroidal melanomas and benign pigmented nevus tissues were 40% and 75% respectively with significant differences between the two groups (χ(2)=5.214, P=0.010). Significant overexpression of connexin 43 and reduction of E-cadherin expression was associated with the invasion to the sclera, and there were respectively significant differences between without and with scleral invasion groups (χ(2)=2.880, P=0.040; χ(2)=2.778, P=0.046). Overexpression of connexin 43 were correlated with tumor cell types and the expression of connexin 43 and E-cadherin may be correlated with each other.

CONCLUSION

The increased expression of connexin 43 and the decreased expression of E-cadherin may be involved in the process of invasion of choroidal melanoma. The overepression of connexin 43 and reduction of E-cadherin may contribute to the development of choroidal melanoma.

Basonuclin-2 requirements for zebrafish adult pigment pattern development and female fertility

Relatively little is known about the generation of adult form. One complex adult trait that is particularly amenable to genetic and experimental analysis is the zebrafish pigment pattern, which undergoes extensive remodeling during post-embryonic development to form adult stripes. These stripes result from the arrangement of three classes of neural crest-derived pigment cells, or chromatophores: melanophores, xanthophores, and iridophores. Here, we analyze the zebrafish bonaparte mutant, which has a normal early pigment pattern but exhibits a severe disruption to the adult stripe pattern. We show that the bonaparte mutant phenotype arises from mutations in basonuclin-2 (bnc2), encoding a highly conserved, nuclear-localized zinc finger protein of unknown function. We show that bnc2 acts non-autonomously to the melanophore lineage and is expressed by hypodermal cells adjacent to chromatophores during adult pigment pattern formation. In bonaparte (bnc2) mutants, all three types of chromatophores differentiate but then are lost by extrusion through the skin. We further show that while bnc2 promotes the development of two genetically distinct populations of melanophores in the body stripes, chromatophores of the fins and scales remain unaffected in bonaparte mutants, though a requirement of fin chromatophores for bnc2 is revealed in the absence of kit and colony stimulating factor-1 receptor activity. Finally, we find that bonaparte (bnc2) mutants exhibit dysmorphic ovaries correlating with infertility and bnc2 is expressed in somatic ovarian cells, whereas the related gene, bnc1, is expressed within oocytes; and we find that both bnc2 and bnc1 are expressed abundantly within the central nervous system. These findings identify bnc2 as an important mediator of adult pigment pattern formation and identify bonaparte mutants as an animal model for dissecting bnc2 functions.