A Rare Complex BRAF Mutation Involving Codon V600 and K601 in Primary Cutaneous Melanoma: Case Report

Clinical and Paraclinical Considerations Regarding ki67's Role in the Management of Differentiated Thyroid Carcinoma-A Literature Review

Background and Objectives: The ki67 nuclear protein is a tool for diagnosis and prognosis in oncology that is used to evaluate cell proliferation. Differentiated thyroid carcinoma is usually a slow-growing neoplasm, the most common type being the papillary form. Some clinical and pathological aspects may predict aggressive behaviour. There are reported cases of recurrence without clinico-pathological findings of aggressiveness. To obtain better predictions of the disease outcome in thyroid carcinoma, many immunohistochemical markers have been studied. The aim of this narrative literature review is to identify the benefits that ki67 may add to the management of patients with differentiated thyroid carcinoma, according to the latest evidence. Materials and Methods: We performed a search on the PubMed and Google Scholar databases using controlled vocabulary and keywords to find the most suitable published articles. A total number of sixty-eight items were identified, and five other articles were selected from other sources. After refining the selection, the inclusion criteria and exclusion criteria were applied, and a total number of twenty-nine articles were included in this literature review. Results and Discussion: The studies consist of retrospective studies (89.66%), case reports (6.9%) and literature reviews (3.45%), evaluating the role, implications and other parameters of ki67 as a diagnostic and/or prognostic tool. The statistical correlations between ki67 and other features were systematized as qualitative results of this review in order to improve the treatment strategies presented in the included articles. Conclusions: The included studies present converging data regarding most of the aspects concerning ki67. The ki67 proliferation index is a diagnostic/prognostic tool of interest in differentiated thyroid carcinoma and a good predictor of disease-free survival, disease recurrence and metastatic development. Prospective studies on large cohorts may add value for ki67 as a specific tool in the management strategy of differentiated thyroid carcinoma.

DNA Sequencing of CD138 Cell Population Reveals TP53 and RAS-MAPK Mutations in Multiple Myeloma at Diagnosis

Multiple myeloma is a hematologic neoplasm caused by abnormal proliferation of plasma cells. Sequencing studies suggest that plasma cell disorders are caused by both cytogenetic abnormalities and oncogene mutations. Therefore, it is necessary to detect molecular abnormalities to improve the diagnosis and management of MM. The main purpose of this study is to determine whether NGS, in addition to cytogenetics, can influence risk stratification and management. Additionally, we aim to establish whether mutational analysis of the CD138 cell population is a suitable option for the characterization of MM compared to the bulk population. Following the separation of the plasma cells harvested from 35 patients newly diagnosed with MM, we performed a FISH analysis to detect the most common chromosomal abnormalities. Consecutively, we used NGS to evaluate NRAS, KRAS, BRAF, and TP53 mutations in plasma cell populations and in bone marrow samples. NGS data showed that sequencing CD138 cells provides a more sensitive approach. We identified several variants in BRAF, KRAS, and TP53 that were not previously associated with MM. Considering that the presence of somatic mutations could influence risk stratification and therapeutic approaches of patients with MM, sensitive detection of these mutations at diagnosis is essential for optimal management of MM.

BRAFV600E;K601Q metastatic melanoma patient-derived organoids and docking analysis to predict the response to targeted therapy

The V600E mutation in BRAF is associated with increased phosphorylation of Erk1/2 and high sensitivity to BRAFi/MEKi combination in metastatic melanoma. In very few patients, a tandem mutation in BRAF, V600 and K601, causes a different response to BRAFi/MEKi combination. BRAF^V600E;K601Q patient-derived organoids (PDOs) were generated to investigate targeted therapy efficacy and docking analysis was used to assess BRAF^V600E;K601Q interactions with Vemurafenib. PDOs were not sensitive to Vemurafenib and Cobimetinib given alone and sensitive to their combination, although not as responsive as BRAF^V600E PDOs. The docking analysis justified such a result showing that the tandem mutation in BRAF reduced the affinity for Vemurafenib. Tumor analysis showed that BRAF^V600E;K601Q displayed both increased phosphorylation of Erk1/2 at cytoplasmic level and activation of Notch resistance signaling. This prompted us to inhibit Notch signaling with Nirogacestat, achieving a greater antitumor response and providing PDOs-based evaluation of treatment efficacy in such rare metastatic melanoma.

A dual identification strategy based on padlock ligation and CRISPR/Cas14a for highly specific detection of BRAF V600E mutation in clinical samples

BRAF V600E mutation is a single-nucleotide variation (SNV) that is widely found in various cancers and has been demonstrated to have a strong association with the prognosis and development of some diseases. Thus, we developed a strategy based on rolling circle amplification (RCA) and CRISPR/Cas14a to meet the great need for detecting highly specific BRAF V600E mutation in fine-needle biopsy samples. In this study, a padlock probe was designed to recognize and trigger subsequent ligase chain reactions (LCR). And due to the Taq DNA ligase, a great number of ligated annular padlock probes were generated in the presence of BRAF V600E mutation, subsequently generating long repeated single-strand DNA by RCA. The obtained amplicons were activators triggering the trans-cleavage of CRISPR/Cas14a. CRISPR/Cas14a shows outstanding performance in identifying ssDNA with single base mutation, which significantly increases the specificity of mutation discrimination. Under the optimal conditions, our strategy can identify BRAF V600E mutation down to 0.307 fM with a wide linear range from 1 fM to 10 pM. On the other hand, the dual identification strategy endows the method with terrific specificity for the detection of SNV. Furthermore, our method has been successfully employed to identify BRAF V600E mutation in clinical fine-needle aspiration samples, proving great potential for ultra-specific identification of low abundance BRAF V600E mutation and providing a novel method for diagnosis and treatment of cancer.

Acetylation-dependent regulation of BRAF oncogenic function

Aberrant BRAF activation, including the BRAF^V600E mutation, is frequently observed in human cancers. However, it remains largely elusive whether other types of post-translational modification(s) in addition to phosphorylation and ubiquitination-dependent regulation also modulate BRAF kinase activity. Here, we report that the acetyltransferase p300 activates the BRAF kinase by promoting BRAF K601 acetylation, a process that is antagonized by the deacetylase SIRT1. Notably, K601 acetylation facilitates BRAF dimerization with RAF proteins and KSR1. Furthermore, K601 acetylation promotes melanoma cell proliferation and contributes to BRAF^V600E inhibitor resistance in BRAF^V600E harboring melanoma cells. As such, melanoma patient-derived K601E oncogenic mutation mimics K601 acetylation to augment BRAF kinase activity. Our findings, therefore, uncover a layer of BRAF regulation and suggest p300 hyperactivation or SIRT1 deficiency as potential biomarkers to determine ERK activation in melanomas.

In tumor cells, hyperactivation of the BRAF protein kinase propels uncontrolled cell proliferation. BRAF hyperactivation is also achieved through several post-translational mechanisms. Dai et al. present an acetylation-dependent regulation of BRAF kinase function in melanoma cells, which serves to enhance BRAF oncogenic function and contributes to BRAF inhibitor resistance.

Cutaneous Melanoma Classification: The Importance of High-Throughput Genomic Technologies

Cutaneous melanoma is an aggressive tumor responsible for 90% of mortality related to skin cancer. In the recent years, the discovery of driving mutations in melanoma has led to better treatment approaches. The last decade has seen a genomic revolution in the field of cancer. Such genomic revolution has led to the production of an unprecedented mole of data. High-throughput genomic technologies have facilitated the genomic, transcriptomic and epigenomic profiling of several cancers, including melanoma. Nevertheless, there are a number of newer genomic technologies that have not yet been employed in large studies. In this article we describe the current classification of cutaneous melanoma, we review the current knowledge of the main genetic alterations of cutaneous melanoma and their related impact on targeted therapies, and we describe the most recent high-throughput genomic technologies, highlighting their advantages and disadvantages. We hope that the current review will also help scientists to identify the most suitable technology to address melanoma-related relevant questions. The translation of this knowledge and all actual advancements into the clinical practice will be helpful in better defining the different molecular subsets of melanoma patients and provide new tools to address relevant questions on disease management. Genomic technologies might indeed allow to better predict the biological - and, subsequently, clinical - behavior for each subset of melanoma patients as well as to even identify all molecular changes in tumor cell populations during disease evolution toward a real achievement of a personalized medicine.