The BRAFV600E mutation, found in approximately 50% of melanoma cases, is associated with aggressive tumor behavior and poor prognosis. This study aimed to assess its impact on immunogenic cell death (ICD), a pivotal cytotoxic process triggering anti-tumor immune responses. Through comprehensive in silico analysis of The Cancer Genome Atlas data, we explored the association between the BRAFV600E mutation, immune subtype dynamics, and tumor mutation burden (TMB). Our findings revealed that the mutation correlated with a lower TMB, indicating a reduced generation of immunogenic neoantigens. Investigation into immune subtypes reveals an exacerbation of immunosuppression mechanisms in BRAFV600E-mutated tumors. To assess the response to ICD inducers, including doxorubicin and Me-ALA-based photodynamic therapy (PDT), compared to the non-ICD inducer cisplatin, we used distinct melanoma cell lines with wild-type BRAF (SK-MEL-2) and BRAFV600E mutation (SK-MEL-28, A375). We demonstrated a differential response to PDT between the WT and BRAFV600E cell lines. Further transcriptomic analysis revealed upregulation of IFNAR1, IFNAR2, and CXCL10 genes associated with the BRAFV600E mutation, suggesting their involvement in ICD. Using a gene reporter assay, we showed that PDT robustly activated the IFN-1 pathway through cGAS-STING signaling. Collectively, our results underscore the complex interplay between the BRAFV600E mutation and immune responses, emphasizing a putative correlation between tumors carrying the mutation and their responsiveness to therapies inducing the IFN-1 pathway, such as the ICD inducer PDT, possibly mediated by the elevated expression of IFNAR1/2 receptors.

Papillary thyroid carcinoma (PTC) accounts for approximately 85%-90% of all thyroid cancers. BRAFV600E mutation is a highly specific target for papillary thyroid carcinoma (PTC) and may have a reciprocal causative relationship with iodide-metabolizing genes. Here, we performed a review of studies published in the past 10 years to determine the relationship between iodine intake and BRAFV600E mutation in patients with PTC. We searched the MEDLINE, PubMed, and EMBASE databases for studies published from 2009 to 2019; seven partially matched the selection criteria and were suitable for review, and five passed all selection criteria. We divided the patients into three groups by iodine intake: low (urinary iodine concentration [UIC] <100 μg/L), adequate (UIC 100–200 μg/L), and high iodine intake groups (UIC ≥200 μg/L). Between-group analysis revealed no significant differences in the odds ratio of the prevalence of BRAFV600E mutation between the high and adequate/low iodine intake groups and between the adequate and low iodine intake groups. To further analyzed the results of studies, they exhibited U-shaped curves in the relation of deficient and excessive dietary iodine intake in BRAFV600E mutation. The results might suggest that iodine intake slightly influences the prevalence of BRAFV600E mutation in patients with PTC despite the heterogeneity of studies. Further research should explore potential mechanisms underlying the associations between iodine intake and BRAF mutation in PTC. The systematic review was registered in PROSPERO (CRD42021279462).

Aberrant glycosylation affects cancer progression and immune evasion. Approximately 15% of colorectal cancers (CRCs) demonstrate microsatellite instability (MSI) and display major differences in outcomes and therapeutic responses as compared to corresponding microsatellite stable (MSS) tumors. We compared the N-glycan profiles of stage II and IV MSI CRC tumors, further subdivided into BRAFV600E wild-type and mutated subgroups (n=10 in each subgroup), with each other and with those of paired non-neoplastic mucosal samples using mass spectrometry. Further, the N-glycans of BRAFV600E wild-type stage II MSI tumors were compared to corresponding MSS tumors (n=9). Multiple differences in N-glycan profiles were identified between MSI CRCs and control tissues, as well as between stage II MSI and MSS samples. MSI CRC tumors showed a lower relative abundance of high-mannose N-glycans than the control tissues or the MSS CRCs. Among MSI CRC subgroups, acidic N-glycans showed tumor stage and BRAF mutation status dependent variation. Especially large, sulfated/phosphorylated, and putative terminal N-acetylhexosamine containing acidic N-glycans differed between the MSI CRC subgroups, showing opposite changes in stage II and IV, when comparing BRAF mutated and wild-type tumors. Our results show that molecular subgroups of CRC have characteristic glycan profiles that may explain certain carcinogenic properties of MSI tumors.

We aimed to assess the prognostic value of BRAFV600E mutation in a series of 127 papillary thyroid carcinoma (PTC) cases as a single factor, as well as in synergic interaction with other standard risk factors. All cases were tested for BRAFV600E mutation by real-time PCR. Event-free survival (EFS) was calculated between the date of the first evaluation and the date of occurrence of an adverse event (tumor recurrence/distant metastasis) or the date of the last known status. The prevalence of BRAFV600E mutation was 57.2%. The Kaplan-Meyer analysis showed a significant reduction of EFS among cases harboring BRAFV600E mutation compared to non-mutated cases (p=0.010). In addition, BRAFV600E mutation was found to better predict adverse outcomes when associated with the following risk factors: age≥55 years-old (p<0.001), male gender (p<0.001), conventional (p=0.005) and tall cell (p=0.014) histology, tumor size&gt;40mm (p=0.001), extrathyroidal extension (p=0.001), multifocality (p=0.001) and lymph node metastasis (p&lt;0.001). In univariate analysis, a 3.74-fold increased risk for a reduced EFS (p=0.018) was found for BRAFV600E mutated cases. Our results highlight the prognostic value of BRAFV600E mutation in PTCs. Moreover, the synergic interaction between BRAFV600E mutation and other risk factors seems more valuable in terms of prognosis, compared to BRAFV600E mutation alone.

The Cancer Genome Atlas (TCGA) has classified papillary thyroid carcinoma (PTC) into indolent RAS-like and aggressive BRAF-like based on its distinct driver gene mutations. This study aimed to assess clinicopathology and pERK1/2 expression variations between BRAF-like and RAS-like PTCs and establish predictive models for BRAFV600E and RAS-mutated PTCs. A total of 222 PTCs underwent immunohistochemistry staining to assess pERK1/2 expression and Sanger sequencing to analyze the BRAF and RAS genes. Multivariate logistic regression was employed to develop prediction model. Independent predictors for the BRAFV600E mutation include a nuclear score of 3, the absence of capsules, an aggressive histology variant, and pERK1/2 levels exceeding 10% (X2=0.128, P&gt;0.05, AUC=0.734, P&lt;0.001). RAS mutation predictive model includes follicular histology variant and pERK1/2 expression &gt;10% (X2=0.174, P&gt;0.05, AUC=0.8, P&lt;0.001). We proposed using the prediction model concurrently with four potential combination group outcomes. PTC cases included in combination of low BRAFV600E-scoring group and high RAS-scoring group are categorized as RAS-like (adjOR=4.857, P=0.01, 95% CI=1.470-16.049). PTCs included in combination of high BRAFV600E-scoring group and low RAS-scoring group are categorized as BRAF-like PTCs (adjOR=3.091, P=0.001, 95% CI=1.594-5.995). The different prediction models indicate variations in biological behaviour between BRAF-like and RAS-like PTCs, necessitating adjustments in treatment approaches.

Papillary thyroid cancer (PTC) is the most common endocrine malignancy which diagnosis and recurrences still challenge clinicians. New perspectives to overcome those issues could come from the study of extracellular vesicles (EVs) populations and content. Here, we aimed to elucidate the heterogeneity of EVs circulating in tumor and the changes in their microRNA content during cancer progression. Using a mouse model expressing BRAF^V600E, we isolated and characterized EVs from thyroid tissue by ultracentrifugations and elucidated their microRNA content by small RNA sequencing. Cellular origin of EVs was investigated by ExoView and that of deregulated EV-microRNA by qPCR on FACS-sorted cell populations. We found that PTC released more EVs bearing epithelial and immune markers, as compared to healthy thyroid, and that changes in EV-microRNAs abundance were mainly due to their deregulated expression in thyrocytes. Pathway analysis showed that the more abundant EV-microRNAs could impact on immune processes. Altogether, our work provides a full description of in vivo-derived EVs produced by, and within, normal and cancerous thyroid. We elucidated the global EV-microRNAs signature, the dynamic loading of microRNAs in EVs upon BRAF^V600E induction, and their cellular origin. Thyroid tumor-derived EV-microRNAs could support the establishment of a permissive immune microenvironment.