Bone Marrow Involvement in Melanoma. Potentials for Detection of Disseminated Tumor Cells and Characterization of Their Subsets by Flow Cytometry

Bone marrow metastases: a systematic review of a neglected involvement in malignant melanoma

The occurrence of bone marrow metastases (BMM) in melanoma patients is often underestimated, with only 7% detected during in-vivo staging procedures but rising to 45% in autopsy cases. This systematic review aims to shed light on the clinical and laboratory features of BMM in melanoma by analyzing 73 studies selected from 2 482 initially retrieved from PubMed, Embase , and Cochrane CENTRAL databases. Our findings reveal a slight male predominance, with a median age at BMM diagnosis of 56 years. Primary melanoma sites included the skin (52%), mucosa (8.8%), uvea (20.5%) and unidentified (19%). BMM was preceded by lymph node involvement in 36.5% of cases, whereas 63% showed no nodal metastases, with direct BMM occurring in 22.5% and metastases to other sites in 41%. Common BMM symptoms included pain (60.7%), anemia (80%), thrombocytopenia, leukoerythroblastosis, pancytopenia and leukopenia, while disseminated intravascular coagulation was detected in 11% of cases. In 23.6% of cases, BMM was amelanotic. The prognosis for BMM is grim, with a median survival of only 2 months. Conventional therapies for BMM remain largely ineffective, emphasizing the importance of considering bone marrow as a potential metastatic site in melanoma patients.

Tumor-derived small extracellular vesicles in cancer invasion and metastasis: molecular mechanisms, and clinical significance

The production and release of tumor-derived small extracellular vesicles (TDSEVs) from cancerous cells play a pivotal role in the propagation of cancer, through genetic and biological communication with healthy cells. TDSEVs are known to orchestrate the invasion-metastasis cascade via diverse pathways. Regulation of early metastasis processes, pre-metastatic niche formation, immune system regulation, angiogenesis initiation, extracellular matrix (ECM) remodeling, immune modulation, and epithelial-mesenchymal transition (EMT) are among the pathways regulated by TDSEVs. MicroRNAs (miRs) carried within TDSEVs play a pivotal role as a double-edged sword and can either promote metastasis or inhibit cancer progression. TDSEVs can serve as excellent markers for early detection of tumors, and tumor metastases. From a therapeutic point of view, the risk of cancer metastasis may be reduced by limiting the production of TDSEVs from tumor cells. On the other hand, TDSEVs represent a promising approach for in vivo delivery of therapeutic cargo to tumor cells. The present review article discusses the recent developments and the current views of TDSEVs in the field of cancer research and clinical applications.

Liquid biopsy for monitoring of tumor dormancy and early detection of disease recurrence in solid tumors

Cancer is one of the three leading causes of death worldwide. Even after successful therapy and achieving remission, the risk of relapse often remains. In this context, dormant residual cancer cells in secondary organs such as the bone marrow constitute the cellular reservoir from which late tumor recurrences arise. This dilemma leads the term of minimal residual disease, which reflects the presence of tumor cells disseminated from the primary lesion to distant organs in patients who lack any clinical or radiological signs of metastasis or residual tumor cells left behind after therapy that eventually lead to local recurrence. Disseminated tumor cells have the ability to survive in a dormant state following treatment and linger unrecognized for more than a decade before emerging as recurrent disease. They are able to breakup their dormant state and to readopt their proliferation under certain circumstances, which can finally lead to distant relapse and cancer-associated death. In recent years, extensive molecular and genetic characterization of disseminated tumor cells and blood-based biomarker has contributed significantly to our understanding of the frequency and prevalence of tumor dormancy. In this article, we describe the clinical relevance of disseminated tumor cells and highlight how latest advances in different liquid biopsy approaches can be used to detect, characterize, and monitor minimal residual disease in breast cancer, prostate cancer, and melanoma patients.

Biological and Clinical Aspects of Metastatic Spinal Tumors

Simple Summary

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Our literature review aimed to describe the up-to-date knowledge about the molecular pathways and biomarkers engaged in the spine’s metastatic processes. Moreover, we described current data regarding bone-targeted treatment, the emerging targeted therapies, radiotherapy, and immunotherapy used for the treatment of spine metastases. We hope that knowledge comprehensively presented in our review will contribute to the development of novel drugs targeting specific biomarkers and pathways. The more we learn about the molecular aspects of cancer metastasis, the easier it will be to look for treatment methods that will allow us to precisely kill tumor cells.

Abstract

Spine metastases are a common life-threatening complication of advanced-stage malignancies and often result in poor prognosis. Symptomatic spine metastases develop in the course of about 10% of malignant neoplasms. Therefore, it is essential for contemporary medicine to understand metastatic processes in order to find appropriate, targeted therapeutic options. Thanks to continuous research, there appears more and more detailed knowledge about cancer and metastasis, but these transformations are extremely complicated, e.g., due to the complexity of reactions, the variety of places where they occur, or the participation of both tumor cells and host cells in these transitions. The right target points in tumor metastasis mechanisms are still being researched; that will help us in the proper diagnosis as well as in finding the right treatment. In this literature review, we described the current knowledge about the molecular pathways and biomarkers engaged in metastatic processes involving the spine. We also presented a current bone-targeted treatment for spine metastases and the emerging therapies targeting the discussed molecular mechanisms.

CD133 Antigen as a Potential Marker of Melanoma Stem Cells: In Vitro and In Vivo Studies

Melanoma is the most dangerous type of skin cancer. Cancer stem cells (CSCs) are suspected to be responsible for the cancer recurrence and in the consequence for cancer therapy failure. CD133 is a potential marker for detection of melanoma CSCs. Experiments were performed on the B16-F10 mouse melanoma cell line. CD133+ cells were isolated using an immunomagnetic cell sorting technique. After isolation proliferative and clonogenic potential of CD133+, CD133- and CD133+/- were evaluated. The potential of CD133+ and CD133- cells for tumor induction was conducted on C57BL/6J mouse model. Three different cell quantities (100, 1000, 10000) were tested. Tumor morphology, number of mitoses, and tumor necrosis area were analyzed. Average 0.12% CD133+ cells were isolated. Compared to CD133- and unsorted CD133+/- cells, CD133+ cells were characterized by the higher proliferative and clonogenic potential. These properties were not confirmed in vivo, as both CD133+ and CD133- cells induced tumor growth in mouse model. No statistical differences in mitosis number and tumor necrosis area were observed. Simultaneous detection of CD133 antigen with other markers is necessary for accurate identification of these melanoma cancer stem cells.