Continued Poor Survival in Metastatic Uveal Melanoma: Implications for Molecular Prognostication, Surveillance Imaging, Adjuvant Therapy, and Clinical Trials

PAK1 and Therapy Resistance in Melanoma

Malignant melanoma claims more lives than any other skin malignancy. While primary melanomas are usually cured via surgical excision, the metastatic form of the disease portents a poor prognosis. Decades of intense research has yielded an extensive armamentarium of anti-melanoma therapies, ranging from genotoxic chemo- and radiotherapies to targeted interventions in specific signaling pathways and immune functions. Unfortunately, even the most up-to-date embodiments of these therapies are not curative for the majority of metastatic melanoma patients, and the need to improve their efficacy is widely recognized. Here, we review the reports that implicate p21-regulated kinase 1 (PAK1) and PAK1-related pathways in the response of melanoma to various therapeutic modalities. Ample data suggest that PAK1 may decrease cell sensitivity to programmed cell death, provide additional stimulation to growth-promoting molecular pathways, and contribute to the creation of an immunosuppressive tumor microenvironment. Accordingly, there is mounting evidence that the concomitant inhibition of PAK1 enhances the potency of various anti-melanoma regimens. Overall, the available information suggests that a safe and effective inhibition of PAK1-dependent molecular processes would enhance the potency of the currently available anti-melanoma treatments, although considerable challenges in implementing such strategies still exist.

Identification of Immune-Related lncRNAs for Predicting Prognosis and Immune Landscape Characteristics of Uveal Melanoma

Immune-related genes and long noncoding RNAs (lncRNAs) have a significant impact on the prognostic value and immunotherapeutic response of uveal melanoma (UM). Therefore, we tried to develop a prognostic model on the basis of irlncRNAs for predicting prognosis and response on immunotherapy of UM patients. We identified 1,664 immune-related genes and 2,216 immune-related lncRNAs (irlncRNAs) and structured a prognostic model with 3 prognostic irlncRNAs by co-expression analysis, univariable Cox, LASSO, and multivariate Cox regression analyses. The Kaplan–Meier analysis indicated that patients in the high-risk group had a shorter survival time than patients in the low-risk group. The ROC curves demonstrated the high sensitivity and specificity of the signature for survival prediction, and the one-, three-, and five-year AUC values, respectively, were 0.974, 0.929, and 0.941 in the entire set. Cox regression analysis, C-index, DCA, PCA analysis, and nomogram were also applied to assess the validity and accuracy of the risk model. The GO and KEGG enrichment analyses indicated that this signature is significantly related to immune-related pathways and molecules. Finally, we investigated the immunological characteristics and immunotherapy of the model and identified various novel potential compounds in the model for UM. In summary, we constructed a new model on the basis of irlncRNAs that can accurately predict prognosis and response on immunotherapy of UM patients, which may provide valuable clinical applications in antitumor immunotherapy.

Genetic Landscape and Emerging Therapies in Uveal Melanoma

Despite successful treatment of primary uveal melanoma, up to 50% of patients will develop systemic metastasis. Metastatic disease portends a poor outcome, and no adjuvant or metastatic therapy has been FDA approved. The genetic landscape of uveal melanoma is unique, providing prognostic and potentially therapeutic insight. In this review, we discuss our current understanding of the molecular and cytogenetic mutations in uveal melanoma, and the importance of obtaining such information. Most of our knowledge is based on primary uveal melanoma and a better understanding of the mutational landscape in metastatic uveal melanoma is needed. Clinical trials targeting certain mutations such as GNAQ/GNA11, BAP1, and SF3B1 are ongoing and promising. We also discuss the role of liquid biopsies in uveal melanoma in this review.

Percutaneous hepatic melphalan perfusion: Single center experience of procedural characteristics, hemodynamic response, complications, and postoperative recovery

Background

Percutaneous hepatic melphalan perfusion (PHMP) for the selective treatment of hepatic metastases is known to be associated with procedural hypotension and coagulation disorders. Studies on anesthetic management, perioperative course, complications, and postoperative recovery in the intensive care unit (ICU) have not been published.

Methods

In a retrospective observational study, we analyzed consecutive patients who were admitted for PHMP over a 6-year period (2016–2021). Analyses included demographic, treatment, and outcome data with regard to short-term complications until ICU discharge.

Results

Fifty-three PHMP procedures of 16 patients were analyzed. In all of the cases, procedure-related hypotension required the median (range) highest noradrenaline infusion rate of 0.5 (0.17–2.1) μg kg min^-1 and fluid resuscitation volume of 5 (3–14) liters. Eighty-four PHMP-related complications were observed in 33 cases (62%), of which 9 cases (27%) involved grade III and IV complications. Complications included airway constriction (requiring difficult airway management), vascular catheterization issues (which resulted in the premature termination of PHMP, as well as to the postponement of PHMP and to the performance of endovascular bleeding control after PHMP), and renal failure that required hemodialysis. Discharge from the ICU was possible after one day in most cases (n = 45; 85%); however, in 12 cases (23%), prolonged mechanical ventilation was required. There were no procedure-related fatalities.

Conclusions

PHMP is frequently associated with challenging cardiovascular conditions and complications that require profound anesthetic skills. For safety reasons, PHMP should only be performed in specialized centers that provide high-level hospital infrastructures and interdisciplinary expertise.

Macrophage polarization contributes to the efficacy of an oncolytic HSV-1 targeting human uveal melanoma in a murine xenograft model

Uveal melanoma (UM), the most common primary malignant tumor of the eye in adults, is difficult-to-treat. UM has a relatively high mortality secondary to distant metastasis and poor overall survival with existing therapies. The oncolytic virus herpes simplex virus type-1 (HSV-1) has been approved for clinical use in melanoma. This double-stranded DNA virus was suspected to directly activate lysis specifically in neoplastic cells. We tested the antitumor efficacy of recombinant oncolytic HSV-1-EGFP (oHSV-EGFP) in UM and characterized the local and systemic antitumor innate immune response in a murine xenograft model. We first determined the efficacy of the oncolytic virus in 92.1, MUM2B and MP41 cell lines. In murine xenograft models, oHSV-EGFP reduced intraocular tumors as well as systemic subcutaneous tumors. A significant change in cytokines was observed in viral infected cells, especially a rise in IFNγ. In vivo analyses showed increased anti-tumorigenic M1 macrophages and decreased pro-tumorigenic M2 macrophages in peripheral blood, and intraocular and distant tumors after intravitreal viral treatment. Increased infiltration of natural killer cells and mature dendritic cells was also detected after viral treatment. In addition, no virus was detected in major organs after the treatment. Our data support that oHSV-EGFP is effective, neoplasm specific, immune active and safe, providing possible clinical translatable options to treat ocular and metastatic UM.

MiR-9-5p Inhibits the Proliferation, Migration and Invasion of Choroidal Melanoma by Targeting BRAF

Objective:

According to different reports, miR-9-5p either facilitates or suppresses the occurrence of tumors. BRAF is a serine/threonine kinase involved in the MAPK pathway and is a proto-oncogene promoting the progression of many tumors, especially melanoma. The present study aimed to reveal the mechanism of action of miR-9-5p and BRAF in choroidal melanoma (CM).

Methods:

RT-qPCR was used to detect the expression of miR-9-5p in CM cells after transfection with miR-9-5p mimics and inhibitor. EdU assay and Transwell assay, respectively, showed the proliferation, migration and invasion of CM cells after transfection with miR-9-5p mimics and inhibitor. A bioinformatics website was used for target prediction and the dual luciferase reporter assay was used to verify the interaction between miR-9-5p and BRAF. RT-qPCR and Western blot were performed to examine the expression of BRAF mRNA and protein, respectively. The BRAF protein was knocked down by siRNAs and then examined by Western blot. The effects of BRAF in CM cells were investigated by EdU assay and Transwell assay. Overexpressing BRAF and transfecting miR-9-5p mimics into choroidal melanoma cells confirmed the interaction between miR-9-5p and BRAF.

Results:

miR-9-5p could bind to the BRAF mRNA 3’UTR and inhibit the transcription and translation of BRAF, thereby suppressing the proliferation, migration and invasion of CM cell lines. Moreover, silencing BRAF inhibited the progression of CM cells.

Conclusions:

In conclusion, this study is the first to investigate the association among BRAF, miR-9-5p and the progression of CM cells. In addition, the interaction between BRAF and miR-9-5p was explored for the first time in CM. Thus, our study suggests that miR-9-5p, BRAF and their interaction may act as potential therapeutic targets for CM.

Antitumor efficacy of oncolytic HSV-1 expressing cytosine deaminase is synergistically enhanced by DPD down-regulation and EMT inhibition in uveal melanoma xenograft

Uveal melanoma (UM) is the most common intraocular tumor in adults and has a high incidence of metastases. Possible treatments remain limited in UM with enucleation and radiation, leading to poor prognosis in this chemo-resistant carcinoma. Thus, urging demand for novel treatment is needed. We examined the antitumor efficacy of a new recombinant oncolytic herpes simplex virus type 1 (oHSV-1) armed with E.coli cytosine deaminase (CD). We determined the efficacy of the oncolytic virus in UM cell lines. In vivo experiments showed that oHSV-CD/5-fluorocytosine (5-FC) treatment reduce tumor volume and prolonged survival. We further demonstrated the molecular mechanisms of oHSV-CD/5-FC treatment. The oncolytic virus down-regulated IL-6 expression and thereby reversed the epithelial-mesenchymal transition (EMT) phenotype. Dihydropyrimidine dehydrogenase (DPD), the rate-limiting enzyme in 5-fluorouracil (5-FU) metabolism, was also down-regulated. Therefore, the efficacy of oHSV-CD/5-FC was synergistically enhanced by DPD down-regulation and EMT inhibition. This study provides solid evidence for the antitumor efficacy of oHSV-CD/5-FC treatment in vitro and in vivo. The molecular mechanisms of this treatment may bring a new therapeutic approach for future treatment of UM.

An Outcome Assessment of a Single Institution's Longitudinal Experience with Uveal Melanoma Patients with Liver Metastasis

There is no FDA-approved treatment for metastatic uveal melanoma (UM) and overall outcomes are generally poor for those who develop liver metastasis. We performed a retrospective single-institution chart review on consecutive series of UM patients with liver metastasis who were treated at Thomas Jefferson University Hospital between 1971–1993 (Cohort 1, n = 80), 1998–2007 (Cohort 2, n = 198), and 2008–2017 (Cohort 3, n = 452). In total, 70% of patients in Cohort 1 received only systemic therapies as their treatment modality for liver metastasis, while 98% of patients in Cohort 2 and Cohort 3 received liver-directed treatment either alone or with systemic therapy. Median Mets-to-Death OS was shortest in Cohort 1 (5.3 months, 95% CI: 4.2–7.0), longer in Cohort 2 (13.6 months, 95% CI: 12.2–16.6) and longest in Cohort 3 (17.8 months, 95% CI: 16.6–19.4). Median Eye Tx-to-Death OS was shortest in Cohort 1 (40.8 months, 95% CI: 37.1–56.9), and similar in Cohort 2 (62.6 months, 95% CI: 54.6–71.5) and Cohort 3 (59.4 months, 95% CI: 56.2–64.7). It is speculated that this could be due to the shift of treatment modalities from DTIC-based chemotherapy to liver-directed therapies. Combination of liver-directed and newly developed systemic treatments may further improve the survival of these patients.

Heterogeneity of GNAQ/11 mutation inversely correlates with the metastatic rate in uveal melanoma

PURPOSE

To determine whether the GNAQ/11 mutation correlated with the outcome of patients with uveal melanoma (UM) when genetic heterogeneity was considered.

METHODS

We performed a retrospective study of sixty-seven patients with UM. The heterogeneity of GNAQ/11 was examined by using droplet digital PCR. The correlation between metastasis and heterogeneity of the GNAQ/11 mutation was analysed. Disease free survival curves were constructed using the Kaplan-Meier method, and the Wilcoxon log-rank test was used to compare the curves.

RESULTS

The GNAQ/11 mutation ratio was varied between each case. Among these patients, 28.35% of them harboured homogeneous mutation of GNAQ/11, 62.69% present heterogeneous mutation and 8.96% didn't present either GNAQ or GNA11 mutation. The tumour with heterogeneous mutation of GNAQ/11 has a higher metastatic rate than that with homogeneous mutation (13/29 vs 1/18, p=0.027). In Kaplan-Meier analysis, metastasis-free survival was not significantly associated with either homogeneous or heterogeneous mutation of GNAQ/11.

CONCLUSION

The mutation ratio of GNAQ/11 in UM was quite variable. The tumour with heterogeneous mutation of GNAQ/11 is more likely to develop a poor prognosis than that with homogeneous mutation of GNAQ/11.