Congenital hepatoblastoma: Expanding knowledge, improving outcomes.

Hepatoblastoma (HB) is a rare liver tumour, and its congenital counterpart (CHB) is even less frequent. CHB has a clinically challenging management and a generally perceived worse outcome. This study aims to review the literature on CHB to better define presentation, diagnosis, available treatments and management options. The analysis of outcomes suggests that a significant portion of mortality is unrelated to the malignant nature of the tumour. Key factors influencing overall outcomes were identified: mortality linked to the 'mass effect' during both the prenatal (22%) and perinatal (32%) stages, as well as 'oncological' mortality encompassing tumour and/or treatment-related factors (46%). Overall, after birth, CHB does not seem to confer a worse oncological prognosis per se, and should be managed similarly to older children, if patients are stable enough to undergo proper staging and treatment. A deeper knowledge and better outcomes would come from a large, homogeneous, collection of data possibly allowing a global protocol, focusing on a comprehensive management of CHB.

Conventional vs. endoscopic-assisted curettage of benign bone tumours. An experimental study.

BACKGROUND: This experimental study aimed at directly comparing conventional and endoscopic-assisted curettage towards (1) amount of residual tumour tissue (RTT) and (2) differences between techniques regarding surgical time and surgeons' experience level. METHODS: Three orthopaedic surgeons (trainee, consultant, senior consultant) performed both conventional (4x each) and endoscopic-assisted curettages (4x each) on specifically prepared cortical-soft cancellous femur and tibia sawbone models. "Tumours" consisted of radio-opaque polyurethane-based foam injected into prepared holes. Pre- and postinterventional CT-scans were carried out and RTT assessed on CT-scans. For statistical analyses, percentage of RTT in relation to total lesion's volume was used. T-tests, Wilcoxon rank-sum tests, and Kruskal-Wallis tests were applied to assess differences between surgeons and surgical techniques regarding RTT and timing. RESULTS: Median overall RTT was 1% (IQR 1 - 4%). Endoscopic-assisted curettage was associated with lower amount of RTT (median, 1%, IQR 0 - 5%) compared to conventional curettage (median, 4%, IQR 0 - 15%, p = 0.024). Mean surgical time was prolonged with endoscopic-assisted (9.2 ± 2.9 min) versus conventional curettage (5.9 ± 2.0 min; p = 0.004). No significant difference in RTT amount (p = 0.571) or curetting time (p = 0.251) depending on surgeons' experience level was found. CONCLUSIONS: Endoscopic-assisted curettage appears superior to conventional curettage regarding complete tissue removal, yet at expenses of prolonged curetting time. In clinical practice, this procedure may be reserved for cases at high risk of recurrence (e.g. anatomy, histology).

The immunomodulatory ballet of tumour-derived extracellular vesicles and neutrophils orchestrating the dynamic CD73/PD-L1 pathway in cancer.

Head and neck squamous cell carcinoma (HNSCC) is a global cancer burden with a 5-year overall survival rate of around 50%, stagnant for decades. A tumour-induced immunosuppressive microenvironment contributes to HNSCC progression, with the adenosine (ADO) pathway and an upregulated expression of inhibitory immune checkpoint regulators playing a key role in this context. The correlation between high neutrophil-to-lymphocyte ratio (NLR) with advanced tumour staging suggests involvement of neutrophils (NØ) in cancer progression. Interestingly, we associated a high NLR with an increased intracellular PD-L1 localization in primary HNSCC samples, potentially mediating more aggressive tumour characteristics and therefore synergistically favouring tumour progression. Still, further research is needed to harness this knowledge for effective treatments and overcome resistance. Since it is hypothesized that the tumour microenvironment (TME) may be influenced by small extracellular vesicles (sEVs) secreted by tumours (TEX), this study aims to investigate the impact of HNSCC-derived TEX on NØ and blockade of ADO receptors as a potential strategy to reverse the pro-tumour phenotype of NØ. UMSCC47-TEX exhibited CD73 enzymatic activity involved in ADO signalling, as well as the immune checkpoint inhibitor PD-L1. Data revealed that TEX induce chemotaxis of NØ and the sustained interaction promotes a shift into a pro-tumour phenotype, dependent on ADO receptors (P1R), increasing CD170high subpopulation, CD73 and PD-L1 expression, followed by an immunosuppressive secretome. Blocking A3R reduced CD73 and PD-L1 expression. Co-culture experiments with HNSCC cells demonstrated that TEX-modulated NØ increase the CD73/PD-L1 axis, through Cyclin D-CDK4/6 signalling. To support these findings, the CAM model with primary tumour was treated with NØ supernatant. Moreover, these NØ promoted an increase in migration, invasion, and reduced cell death. Targeting P1R on NØ, particularly A3R, exhibited potential therapeutic strategy to counteract immunosuppression in HNSCC. Understanding the TEX-mediated crosstalk between tumours and NØ offers insights into immunomodulation for improving cancer therapies.

Canine ovarian epithelial tumours: histopathological and immunohistochemical evaluation with proposed histopathological classification system.

Canine ovarian epithelial tumours (OETs) are currently divided into ovarian adenomas and carcinomas, which are further inconsistently subclassified as papillary or cystic, whereas in human medicine, OETs are subdivided into several subtypes. This study aimed to establish clear morphological features enabling more consistent distinction between benign OETs and ovarian carcinomas (OvCas) as well as defining different histopathological patterns of canine OvCas. Analysis revealed a mitotic count threshold of >2 as a potential criterion for differentiating OvCas from benign OETs. Alongside ovarian adenomas, ovarian borderline tumours were introduced as a distinct category among benign OETs. OvCas exhibited five different histopathological patterns, namely papillary, solid with tubular differentiation, micropapillary, cystic and sarcomatous. Since some OvCas can morphologically overlap with other ovarian tumours, the expression of cytokeratin 7, a cytokeratin expressed in ovarian epithelium, was assessed and proved helpful, although it was not expressed in all cases. Furthermore, we investigated the expression of 14-3-3σ and cyclooxygenase 2 (COX-2). Based on the frequent expression of 14-3-3σ, this marker appears to have a role in canine OETs since it is not expressed in normal canine ovaries. The infrequent expression of COX-2 suggests that it is a poor candidate as a potential therapeutic target in canine OvCas.

Novel post-translational modifications of protein by metabolites with immune responses and immune-related molecules in cancer immunotherapy.

Tumour immunotherapy is an effective and essential treatment for cancer. However, the heterogeneity of tumours and the complex and changeable tumour immune microenvironment (TME) creates many uncertainties in the clinical application of immunotherapy, such as different responses to tumour immunotherapy and significant differences in individual efficacy. It makes anti-tumour immunotherapy face many challenges. Immunometabolism is a critical determinant of immune cell response to specific immune effector molecules, significantly affecting the effects of tumour immunotherapy. It is attributed mainly to the fact that metabolites can regulate the function of immune cells and immune-related molecules through the protein post-translational modifications (PTMs) pathway. This study systematically summarizes a variety of novel protein PTMs including acetylation, propionylation, butyrylation, succinylation, crotonylation, malonylation, glutarylation, 2-hydroxyisobutyrylation, ß-hydroxybutyrylation, benzoylation, lactylation and isonicotinylation in the field of tumour immune regulation and immunotherapy. In particular, we elaborate on how different PTMs in the TME can affect the function of immune cells and lead to immune evasion in cancer. Lastly, we highlight the potential treatment with the combined application of target-inhibited protein modification and immune checkpoint inhibitors (ICIs) for improved immunotherapeutic outcomes.

Evaluation of mRNA lipoplexes prepared using modified ethanol injection method as a tumour vaccine.

We have previously demonstrated that messenger RNA (mRNA) lipoplexes composed of N-hexadecyl-N,N-dimethylhexadecan-1-aminium bromide (DC-1-16), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and polyethylene glycol-cholesteryl ether (PEG-Chol) exhibited high protein expression in the lungs and spleen of mice after intravenous injection and induced high levels of antigen-specific IgG1 upon immunisation. In this study, we optimised PEG modification in mRNA lipoplexes to reduce mRNA accumulation in the lungs and evaluated the suppression of tumour growth in mice bearing mouse lymphoma E.G7-ovalbumin (OVA) tumours by immunising them with an intravenous injection of OVA mRNA lipoplexes. PEGylation of mRNA lipoplexes with 3 mol% PEG-Chol (LP-DC-1-16-3PCL) prevented agglutination of erythrocytes and reduced accumulation in the lungs. Intravenous injection of LP-DC-1-16-3PCL lipoplexes containing OVA mRNA into mice induced high levels of anti-OVA IgG1 (83,000 mU/mL) in serum, and exhibited a high cytotoxic activity (97%) against E.G7-OVA cells by the splenocytes of mice. Furthermore, immunisation with LP-DC-1-16-3PCL lipoplexes containing OVA mRNA suppressed E.G7-OVA tumour growth compared to control mRNA. Based on these results, LP-DC-1-16-3PCL lipoplexes may be an effective mRNA vaccine for inducing antibody- and cytotoxic cell-mediated immune responses to tumours through intravenous injection.

Emergency myelopoiesis in solid cancers.

Cells of the innate and adaptive immune systems are the progeny of haematopoietic stem and progenitor cells (HSPCs). During steady-state myelopoiesis, HSPC undergo differentiation and proliferation but are called to respond directly and acutely to various signals that lead to emergency myelopoiesis, including bone marrow ablation, infections, and sterile inflammation. There is extensive evidence that many solid tumours have the potential to secrete classical myelopoiesis-promoting growth factors and other products able to mimic emergency haematopoiesis, and to aberrantly re-direct myeloid cell development into immunosuppressive cells with tumour promoting properties. Here, we summarize the current literature regarding the effects of solid cancers on HSPCs function and discuss how these effects might shape antitumour responses via a mechanism initiated at a site distal from the tumour microenvironment.

Neuroanatomy of cerebellar mutism syndrome: the role of lesion location.

Approximately 25% of paediatric patients who undergo cerebellar tumour resection develop cerebellar mutism syndrome. Our group recently showed that damage to the cerebellar deep nuclei and superior cerebellar peduncles, which we refer to as the cerebellar outflow pathway, is associated with an increased risk of cerebellar mutism syndrome. Here, we tested whether these findings replicate in an independent cohort. We evaluated the relationship between lesion location and the development of cerebellar mutism syndrome in an observational study of 56 paediatric patients ranging from five months to 14 years of age who underwent cerebellar tumour resection. We hypothesized that individuals who developed cerebellar mutism syndrome after surgery, relative to those who did not, would have lesions that preferentially intersect with: (i) the cerebellar outflow pathway and (ii) a previously generated 'lesion-symptom map' of cerebellar mutism syndrome. Analyses were conducted in accordance with pre-registered hypotheses and analytic methods (https://osf.io/r8yjv/). We found supporting evidence for both hypotheses. Compared to patients who did not develop cerebellar mutism syndrome, patients with cerebellar mutism syndrome (n = 10) had lesions with greater overlap with the cerebellar outflow pathway (Cohen's d = 0.73, P = 0.05), and the cerebellar mutism syndrome lesion-symptom map (Cohen's d = 1.1, P = 0.004). These results strengthen the association of lesion location with the risk of developing cerebellar mutism syndrome and demonstrate generalizability across cohorts. These findings may help to inform the optimal surgical approach to paediatric cerebellar tumours.

Hypercalcaemia in gastrointestinal stromal tumour and sarcoidosis: a case report.

BACKGROUND: Hypercalcaemia is a common manifestation of sarcoidosis but is sparingly described in gastrointestinal stromal tumours (GISTs). We describe a case of acute kidney injury and hypercalcemia resulting from simultaneous diagnosis of GIST and sarcoidosis, the presentation of which has not yet been reported. CASE PRESENTATION: A 61-year-old male presented with acute kidney injury and hypercalcemia, with elevated 1,25-dihydroxyvitamin D levels. Investigations demonstrated a large gastric antral mass which was resected and proven to be GIST. Histopathology of incidentally found liver nodules revealed non-necrotising epithelioid granulomas consistent with concomitant sarcoidosis. The hypercalcemia was successfully treated with bisphosphonate therapy, resection of the GIST and a four month course of corticosteroids, which was truncated due to a mycobacterial infection. CONCLUSIONS: Our case report is the first to describe hypercalcemia due to GIST and biopsy-proven sarcoidosis, thereby raising the possibility of a common pathophysiological pathway relating the two entities. We review the literature describing the mechanisms of hypercalcaemia in GIST and the association between GIST and sarcoidosis.

Clinicopathologic and molecular study of superficial CD34-positive fibroblastic tumours mimicking atypical fibrous histiocytoma (dermatofibroma).

AIMS: Superficial CD34-positive fibroblastic tumour (SCD34FT) is an uncommon but distinctive low-grade neoplasm of the skin and subcutis that shows frequent CADM3 expression by immunohistochemistry (IHC). In this study, prompted by an index case resembling 'atypical fibrous histiocytoma (FH)' that was positive for CADM3 IHC, we systematically examined a cohort of tumours previously diagnosed as 'atypical FH' by applying CADM3 and fluorescence in situ hybridization (FISH) for PRDM10 rearrangement, to investigate the overlap between these tumour types. METHODS AND RESULTS: Forty cases of atypical FH were retrieved, including CD34-positive tumours (n = 20) and CD34-negative tumours (n = 20). All tumours were stained for CADM3. All CADM3-positive tumours were evaluated by FISH to assess for PRDM10 rearrangement. Eleven CD34-positive tumours (11/20, 55%) coexpressed CADM3 and were reclassified as SCD34FT. None (0/20) of the CD34-negative atypical FH were CADM3-positive. Reclassified SCD34FT (10/11) arose on the lower extremity, with frequent involvement of the thigh (n = 8). Features suggestive of atypical FH were observed in many reclassified cases including variable cellularity, spindled morphology, infiltrative tumour margins, collagen entrapment, epidermal hyperpigmentation, and acanthosis. Variably prominent multinucleate giant cells, including Touton-like forms, were also present. An informative FISH result was obtained in 10/11 reclassified tumours, with 60% (6/10) demonstrating PRDM10 rearrangement. CONCLUSION: A significant subset of tumours that histologically resemble atypical FH, and are positive for CD34, coexpress CADM3 and harbour PRDM10 rearrangement, supporting their reclassification as SCD34FT. Awareness of this morphologic overlap and the application of CADM3 IHC can aid the distinction between SCD34FT and atypical FH.

TP53 mutations in urothelial carcinoma: not all one and the same†.

Systemic therapy options for urothelial carcinoma have expanded in recent years, with both immunotherapy and cytotoxic chemotherapy being widely available. However, we lack biomarkers to select which drug is likely to work best in individual patients. A new article in this journal by Jin, Xu, Su, et al reports that disruptive versus non-disruptive TP53 mutations may guide these personalised therapy choices. Intriguingly, patients with disruptive TP53 tumour mutations had poor overall survival versus those with non-disruptive TP53 mutations or wild type TP53 but responded particularly well to immunotherapy. Of relevance, an increased tumour mutational burden and increased effector CD8+ T-cell infiltration was seen in tumours with disruptive mutations. The impact of different TP53 mutations on prognosis and therapy choices appears to be tumour- and therapy-type specific, with no clear consensus on overall tumour phenotype according to type of mutation. Nonetheless, profiling of specific types of TP53 mutation is increasingly clinically feasible with targeted sequencing or immunohistochemistry. There is an urgent need for additional studies in urothelial cancer clarifying how the type of TP53 mutation present within a tumour can best be used as a predictive biomarker. Further important remaining questions include the impact of TP53 mutations on other clinically important aspects of the tumour microenvironment, including cancer-associated fibroblasts. Furthermore, the impact of gain-of-function mutations in TP53 and other related genes signalling upstream or downstream of TP53 is of wide interest. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

A detailed insight into macrophages' role in shaping lung carcinogenesis.

Despite significant advancements in cancer treatment in recent decades, the high mortality rate associated with lung cancer remains a significant concern. The development and proper execution of new targeted therapies needs more deep knowledge regarding the lung cancer associated tumour microenvironment. One of the key component of that tumour microenvironment is the lung resident macrophages. Although in normal physiological condition the lung resident macrophages are believed to maintain lung homeostasis, but they may also initiate a vicious inflammatory response in abnormal conditions which is linked to lung cancer development. Depending on the activation pathway, the lung resident macrophages are either of M1 or M2 sub-type. The M1 and M2 sub-types differ significantly in various prospectuses, from phenotypic markers to metabolic pathways. In addition to this generalized classification, the recent advancement of the multiomics technology is able to identify some other sub-types of lung resident macrophages. Researchers have also observed that these different sub-types can manipulate the pathogenesis of lung carcinogenesis in a context dependent manner and can either promote or inhibit the development of lung carcinogenesis upon receiving proper activation. As proper knowledge about the role played by the lung resident macrophages' in shaping the lung carcinogenesis is limited, so the main purpose of this review is to bring all the available information under the same roof. We also elaborated the different mechanisms involved in maintenance of the plasticity of M1/M2 sub-type, as this plasticity can be a good target for lung cancer treatment.

Cell dehydration enables massive production of engineered membrane vesicles with therapeutic functions.

Extracellular vesicles (EVs) have emerged as promising biomaterials for the treatment of different disease. However, only handful types of EVs with clinical transformation potential have been reported to date, and their preparation on a large scale under biosafety-controlled conditions is limited. In this study, we characterize a novel type of EV with promising clinical application potential: dehydration-induced extracellular vesicles (DIMVs). DIMV is a type of micron-diameter cell vesicle that contains more bioactive molecules, such as proteins and RNA, but not DNA, than previously reported cell vesicles. The preparation of DIMV is extraordinarily straightforward, which possesses a high level of biosafety, and the protein utilization ratio is roughly 600 times greater than that of naturally secreted EVs. Additional experiments demonstrate the viability of pre- or post-isolation DIMV modification, including gene editing, nucleic acid encapsulation or surface anchoring, size adjustment. Finally, on animal models, we directly show the biosafety and immunogenicity of DIMV, and investigate its potential application as tumour vaccine or drug carrier in cancer treatment.

Baohuoside I chemosensitises breast cancer to paclitaxel by suppressing extracellular vesicle/CXCL1 signal released from apoptotic cells.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and chemotherapy is the cornerstone treatment for TNBC. Regrettably, emerging findings suggest that chemotherapy facilitates pro-metastatic changes in the tumour microenvironment. Extracellular vesicles (EVs) have been highly implicated in cancer drug resistance and metastasis. However, the effects of the EVs released from dying cancer cells on TNBC prognosis and corresponding therapeutic strategies have been poorly investigated. This study demonstrated that paclitaxel chemotherapy elicited CXCL1-enriched EVs from apoptotic TNBC cells (EV-Apo). EV-Apo promoted the chemoresistance and invasion of co-cultured TNBC cells by polarizing M2 macrophages through activating PD-L1 signalling. However, baohuoside I (BHS) remarkably sensitized the co-cultured TNBC cells to paclitaxel chemotherapy via modulating EV-Apo signalling. Mechanistically, BHS remarkably decreased C-X-C motif chemokine ligand 1 (CXCL1) cargo within EV-Apo and therefore attenuated macrophage M2 polarization by suppressing PD-L1 activation. Additionally, BHS decreased EV-Apo release by diminishing the biogenesis of intraluminal vesicles (ILVs) within multivesicular bodies (MVBs) of TNBC cells. Furthermore, BHS bound to the LEU104 residue of flotillin 2 (FLOT2) and interrupted its interaction with RAS oncogene family member 31 (RAB31), leading to the blockage of RAB31-FLOT2 complex-driven ILV biogenesis. Importantly, BHS remarkably chemosensitised paclitaxel to inhibit TNBC metastasis in vivo by suppressing EV-ApoCXCL1-induced PD-L1 activation and M2 polarization of tumour-associated macrophages (TAMs). This pioneering study sheds light on EV-ApoCXCL1 as a novel therapeutic target to chemosensitise TNBC, and presents BHS as a promising chemotherapy adjuvant to improve TNBC chemosensitivity and prognosis by disturbing EV-ApoCXCL1 biogenesis.

Hjernetegn.dk-The Danish Central Nervous System Tumor Awareness Initiative Digital Decision Support Tool: Design and Implementation Report.

BACKGROUND: Childhood tumors in the central nervous system (CNS) have longer diagnostic delays than other pediatric tumors. Vague presenting symptoms pose a challenge in the diagnostic process; it has been indicated that patients and parents may be hesitant to seek help, and health care professionals (HCPs) may lack awareness and knowledge about clinical presentation. To raise awareness among HCPs, the Danish CNS tumor awareness initiative hjernetegn.dk was launched. OBJECTIVE: This study aims to present the learnings from designing and implementing a decision support tool for HCPs to reduce diagnostic delay in childhood CNS tumors. The aims also include decisions regarding strategies for dissemination and use of social media, and an evaluation of the digital impact 6 months after launch. METHODS: The phases of developing and implementing the tool include participatory co-creation workshops, designing the website and digital platforms, and implementing a press and media strategy. The digital impact of hjernetegn.dk was evaluated through website analytics and social media engagement. IMPLEMENTATION (RESULTS): hjernetegn.dk was launched in August 2023. The results after 6 months exceeded key performance indicators. The analysis showed a high number of website visitors and engagement, with a plateau reached 3 months after the initial launch. The LinkedIn campaign and Google Search strategy also generated a high number of impressions and clicks. CONCLUSIONS: The findings suggest that the initiative has been successfully integrated, raising awareness and providing a valuable tool for HCPs in diagnosing childhood CNS tumors. The study highlights the importance of interdisciplinary collaboration, co-creation, and ongoing community management, as well as broad dissemination strategies when introducing a digital support tool.

Metabolic tumour area: a novel prognostic indicator based on 18F-FDG PET/CT in patients with diffuse large B-cell lymphoma in the R-CHOP era.

BACKGROUND: The metabolic tumour area (MTA) was found to be a promising predictor of prostate cancer. However, the role of MTA based on 18F-FDG PET/CT in diffuse large B-cell lymphoma (DLBCL) prognosis remains unclear. This study aimed to elucidate the prognostic significance of MTA and evaluate its incremental value to the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) for DLBCL patients treated with first-line R-CHOP regimens. METHODS: A total of 280 consecutive patients with newly diagnosed DLBCL and baseline 18F-FDG PET/CT data were retrospectively evaluated. Lesions were delineated via a semiautomated segmentation method based on a 41% SUVmax threshold to estimate semiquantitative metabolic parameters such as total metabolic tumour volume (TMTV) and MTA. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off values. Progression-free survival (PFS) and overall survival (OS) were the endpoints that were used to evaluate the prognosis. PFS and OS were estimated via Kaplan‒Meier curves and compared via the log-rank test. RESULTS: Univariate analysis revealed that patients with high MTA, high TMTV and NCCN-IPI ≥ 4 were associated with inferior PFS and OS (P < 0.0001 for all). Multivariate analysis indicated that MTA remained an independent predictor of PFS and OS [hazard ratio (HR), 2.506; 95% confidence interval (CI), 1.337-4.696; P = 0.004; and HR, 1.823; 95% CI, 1.005-3.310; P = 0.048], whereas TMTV was not. Further analysis using the NCCN-IPI model as a covariate revealed that MTA and NCCN-IPI were still independent predictors of PFS (HR, 2.617; 95% CI, 1.494-4.586; P = 0.001; and HR, 2.633; 95% CI, 1.650-4.203; P < 0.0001) and OS (HR, 2.021; 95% CI, 1.201-3.401; P = 0.008; and HR, 3.869; 95% CI, 1.959-7.640; P < 0.0001; respectively). Furthermore, MTA was used to separate patients with high NCCN-IPI risk scores into two groups with significantly different outcomes. CONCLUSIONS: Pre-treatment MTA based on 18F-FDG PET/CT and NCCN-IPI were independent predictor of PFS and OS in DLBCL patients treated with R-CHOP. MTA has additional predictive value for the prognosis of patients with DLBCL, especially in high-risk patients with NCCN-IPI ≥ 4. In addition, the combination of MTA and NCCN-IPI may be helpful in further improving risk stratification and guiding individualised treatment options. TRIAL REGISTRATION: This research was retrospectively registered with the Ethics Committee of the Third Affiliated Hospital of Soochow University, and the registration number was approval No. 155 (approved date: 31 May 2022).

Unravelling tumour cell diversity and prognostic signatures in cutaneous melanoma through machine learning analysis.

Melanoma, a highly malignant tumour, presents significant challenges due to its cellular heterogeneity, yet research on this aspect in cutaneous melanoma remains limited. In this study, we utilized single-cell data from 92,521 cells to explore the tumour cell landscape. Through clustering analysis, we identified six distinct cell clusters and investigated their differentiation and metabolic heterogeneity using multi-omics approaches. Notably, cytotrace analysis and pseudotime trajectories revealed distinct stages of tumour cell differentiation, which have implications for patient survival. By leveraging markers from these clusters, we developed a tumour cell-specific machine learning model (TCM). This model not only predicts patient outcomes and responses to immunotherapy, but also distinguishes between genomically stable and unstable tumours and identifies inflamed ('hot') versus non-inflamed ('cold') tumours. Intriguingly, the TCM score showed a strong association with TOMM40, which we experimentally validated as an oncogene promoting tumour proliferation, invasion and migration. Overall, our findings introduce a novel biomarker score that aids in selecting melanoma patients for improved prognoses and targeted immunotherapy, thereby guiding clinical treatment decisions.

A Novel Method for the Early Detection of Single Circulating, Metastatic and Self-Seeding Cancer Cells in Orthotopic Breast Cancer Mouse Models.

BACKGROUND: Metastasis is the main cause of cancer-related deaths, but efficient targeted therapies against metastasis are still missing. Major gaps exist in our understanding of the metastatic cascade, as existing methods cannot combine sensitivity, robustness, and practicality to dissect cancer progression. Addressing this issue requires improved strategies to distinguish early metastatic colonization from metastatic outgrowth. METHODS: Luciferase-labelled MDA-MB-231, MCF7, and 4T1 breast cancer cells were spiked into samples from tumour-naïve mice to establish the limit of detection for disseminated tumour cells. Luciferase-labelled breast cancer cells (±unlabelled cancer-associated fibroblasts; CAFs) were orthotopically implanted in immunocompromised mice. An ex vivo luciferase assay was used to quantify tumour cell dissemination. RESULTS: In vitro luciferase assay confirmed a linear and positive correlation between cancer cell numbers and the bioluminescence detected at single cell level in blood, brain, lung, liver, and mammary fat pad samples. Remarkably, single luciferase-labelled cancer cells were detectable in all of these sites, as the bioluminescence quantified in the analysed samples was substantially higher than background levels. Ex vivo, circulating tumour cells, metastasis, and tumour self-seeding were detected in all samples from animals implanted with highly metastatic luciferase-labelled MDA-MB-231 cells. In turn, detection of poorly metastatic luciferase-labelled MCF7 cells was scarce but significantly enhanced upon co-implantation with CAFs as early as 20 days after the experiment was initiated. CONCLUSIONS: These results demonstrate the feasibility of using an ultrasensitive luciferase-based method to dissect the mechanisms of early metastatic colonization to improving the development of antimetastatic therapies.

Pulmonary Adenocarcinoma with Cutaneous Metastasis in a Dog.

Primary lung cancer is rare in dogs and depending on the tumour stage and subtype, the prognosis can be poor. In this report, we describe a 10 year-old female intact Yorkshire terrier that presented progressive weight loss and chronic pain of unknown origin. Due to the poor condition of the dog, it was subsequently euthanized. Post-mortem evaluation revealed a single large mass in the left caudal lung lobe, with numerous pale, proliferative lesions of various sizes dispersed throughout all the lobes. Additionally, a solitary skin mass was palpated on the mid-thoracic body wall. Histopathological examination of the lung samples revealed multiple distinct, non-encapsulated, expansive neoplastic epithelial cell proliferations with dense cellularity, exhibiting growth patterns, ranging from papillary to micropapillary to solid, accompanied by central areas of necrosis. In some areas, microvilli-like structures were observed on the luminal cytoplasmic margins of the neoplastic cells. The histopathology of the skin mass closely resembled that of the lung. Electron microscopy of the skin samples revealed regions containing cells resembling the respiratory epithelium, along with cells exhibiting processes or microvilli indicative of cilia. The diagnosis was pulmonary adenocarcinoma with cutaneous metastasis. This is the first report of a canine with primary lung cancer that metastasized to the skin.