The aim of this thesis was to develop novel treatment strategies for different types of eye melanoma utilizing zebrafish models. We first establish orthotopic and ectopic xenograft models for uveal... Show moreThe aim of this thesis was to develop novel treatment strategies for different types of eye melanoma utilizing zebrafish models. We first establish orthotopic and ectopic xenograft models for uveal and conjunctival melanoma by engraftment of the immortalized cells derived from these tumors into zebrafish embryos. Next, we expanded these models with spheroids and zebrafish patient-derived xenografts for pre-clinical, personalized screening of anti-uveal melanoma drug responses. We demonstrated that these models can be harnessed to explore the in vivo interactions of the tumor cells with blood vessels and macrophages leading to angiogenic response. We finally apply the conjunctival melanoma model to clarify the inhibitory effects of ginsenosides and correlate their structures with potential antitumoral mechanisms. Show less
Ocular melanoma is a rare disease that originates from melanocytes in the eye. It is the most prevalent primary ocular malignancy in adults, and has a high metastatic rate. Two important questions... Show moreOcular melanoma is a rare disease that originates from melanocytes in the eye. It is the most prevalent primary ocular malignancy in adults, and has a high metastatic rate. Two important questions for good patient care are: 1) How to differentiate between (benign) nevi, and (malignant) melanoma?, and 2) How to treat this tumor best, particularly in cases with metastases?This thesis addresses two types of ocular melanoma: melanoma of the internal parts of the eye (uveal melanoma) and melanoma of the mucous membrane covering the eye (conjunctival melanoma). This thesis combines patient-related projects with projects from the lab.With new imaging techniques we demonstrate that oxygen values differ in eyes with melanoma compared to other eyes including those with a nevus. We use OCT-angiography to depict tumour vessels non-invasively in conjunctival and iris lesions. These two techniques may be used in the future to differentiate lesions, and to monitor patients after treatment.With studies in the lab we show that new drugs (immunotherapy) that are recently used in cutaneous melanoma, can also be used to treat conjunctival melanoma. We show that vascular growth in uveal melanoma is related to other (genetic and immunologic) characteristics, providing new clues for therapy. Show less
Recent developments in oncology have led to a better molecular and cellular understanding of cancer, and the introduction of novel therapies. Conjunctival melanoma (CoM) is a rare but potentially... Show moreRecent developments in oncology have led to a better molecular and cellular understanding of cancer, and the introduction of novel therapies. Conjunctival melanoma (CoM) is a rare but potentially devastating disease. A better understanding of CoM, leading to the development of novel therapies, is urgently needed. CoM is characterized by mutations that have also been identified in cutaneous melanoma, e.g. in BRAF, NRAS and TERT. These mutations are distinct from the mutations found in uveal melanoma (UM), affecting genes such as GNAQ, GNA11, and BAP1. Targeted therapies that are successful in cutaneous melanoma may therefore be useful in CoM. A recent breakthrough in the treatment of patients with metastatic cutaneous melanoma was the development of immunotherapy. While immunotherapy is currently sparsely effective in intraocular tumours such as UM, the similarities between CoM and cutaneous melanoma (including in their immunological tumour micro environment) provide hope for the application of immunotherapy in CoM, and preliminary clinical data are indeed emerging to support this use. This review aims to provide a comprehensive overview of the current knowledge regarding CoM, with a focus on the genetic and immunologic understanding. We elaborate on the distinct position of CoM in contrast to other types of melanoma, and explain how new insights in the pathophysiology of this disease guide the development of new, personalized, treatments. Show less
Zaks, O.; Gaber, D.; Ben-Yaakov, K.; Sharvit-Bader, M.; Goz, A.; Rotfogel, Z.; ... ; Aharoni-Simon, M. 2021
Uveal melanoma (UM) and conjunctival melanoma (CM) are ocular malignancies that give rise to life-threatening metastases. Although local disease can often be treated successfully, it is often... Show moreUveal melanoma (UM) and conjunctival melanoma (CM) are ocular malignancies that give rise to life-threatening metastases. Although local disease can often be treated successfully, it is often associated with significant vision impairment and treatments are often not effective against metastatic disease. Novel treatment modalities that preserve vision may enable elimination of small tumors and may prevent subsequent metastatic spread.Very few mouse models of metastatic CM and UM are available for research and for development of novel therapies. One of the challenges is to follow tumor growth in-vivo and to determine the right size for treatment, mainly of the posterior, choroidal melanoma. Hence, the purpose of this study was to establish a simple, noninvasive imaging tool that will simplify visualization and tumor follow-up in mouse models of CM and UM.Tumors were induced by inoculation of murine B16LS9 cells into the sub-conjunctival or the choroidal space of a C57BL/6 mouse eye under a surgical microscope. Five to ten days following injection, tumor size was assessed by Phoenix MicronIVTM image-guided Optical Coherence Tomography (OCT) imaging, which included a realtime camera view and OCT scan of the conjunctiva and the retina. In addition, tumor size was evaluated by ultrasound and histopathological examination of eye sections.Tumor growth was observed 5-9 days following sub-conjunctival or sub-retinal injection of seven-thousand or seventy-thousand cells, respectively. A clear tumor mass was detected at these regions using the MicronIVTM imaging system camera and OCT scans. Histology of eye sections confirmed the presence of tumor tissue. OCT allowed an accurate measurement of tumor size in the UM model and a qualitative assessment of tumor size in the CM model. Moreover, OCT enabled assessing the success rate of the choroidal tumor induction and importantly, predicted final tumor size already on the day of cell inoculation.In conclusion, by using a simple, non-invasive imaging tool, we were able to follow intraocular tumor growth of both CM and UM, and to define, already at the time of cell inoculation, a grading scale to evaluate tumor size. This tool may be utilized for evaluation of new mouse models for CM and UM, as well as for testing new therapies for these diseases. Show less
This thesis identifies specific targets, illustrates the role of these targets, and explores personalized therapeutic possibilities to inhibit tumor growth by using new treatment strategies.... Show moreThis thesis identifies specific targets, illustrates the role of these targets, and explores personalized therapeutic possibilities to inhibit tumor growth by using new treatment strategies. And the thesis describes a new animal model for CM. A proper model can mimic the human disorder and provide opportunities for studying tumor biology, and for seeking novel effective therapies to inhibit the dissemination of malignant cells. Subsequently, the potential role of immune checkpoint molecules and the presence of HLA class I antigens are studied. New animal models and therapeutic targets will broaden our understanding of CM, and help us to develop better treatments for primary and metastatic CM, thus prolonging patients’ survival. Show less
