Tumor Vasculature Research Articles

Molecular Testing Prevents Overdiagnosis of Epithelioid Hemangioma

Abstract Introduction/Objective Epithelioid hemangiomas (EH) are mostly solitary benign vascular tumors commonly involving the dermal and subcutaneous areas of the head and neck. However, reports of multifocality are increasing, specially in same anatomic region. Some reported cases of EH show morphologic features that may mimic malignant vascular tumors such as hemangioendotheliomas or angiosarcomas. However, there are no reported overlaps in the molecular characteristics of these tumors. We describe a multifocal EH with atypical features, suspicious for angiosarcoma, which needed molecular testing to resolve the diagnosis. Methods/Case Report The patient is a previously healthy 42-year-old male with a 5-month history of multiple growing painless penile nodules. Biopsy of one of the nodules was done. Histologic examination showed multifocal dermal- based ill-circumscribed nodules with interspersed inflammatory infiltrates and focal areas of necrosis. Tumor periphery shows vasoformative growth with intraluminal and extravasated red blood cells. Neoplastic cells were large and ovoid with abundant eosinophilic cytoplasm, large vesicular pleomorphic nuclei and prominent nucleoli. Immunohistochemical stains showed strong expression of ERG, FLI-1, and CD31 and negativity for AE1/AE3, CD34, HHV8 and EMA. The morphologic and immunohistochemical features of the specimen showed significant overlap of two primary differential diagnoses - epithelioid angiosarcoma and epithelioid hemangioma. Ultimately, molecular testing revealed ZFP36-FOSB fusion, confirming the diagnosis of EH. Results (if a Case Study enter NA) NA Conclusion Differentiating benign and malignant epithelioid vascular neoplasms can sometimes be challenging. There can be overlap in terms of architectural variety, presence of necrosis, vasoformation, inflammatory cell components and cytologic features, especially in EH with atypical features and epithelioid angiosarcoma (EA). Both of these tumors show positive immunoreactivity for CD31, CD34, FLI1 and ERG, and negativity for most keratins. Currently, the most reliable way to distinguish each tumor is molecular testing, with EH having FOS/FOSB rearrangements and EA with MYC or FLT4 amplification. Benign and malignant epithelioid vascular tumors can be indistinguishable morphologically and immunohistochemically. Molecular tests can help differentiate these neoplasms to better tailor patient management.

USING CCA-MRI TO PREDICT RESPONSE TO STEREOTACTIC RADIOSURGERY IN PATIENTS WITH BRAIN METASTASES

Abstract AIMS Brain metastases (BMs) from different primary cancers may have different radiosensitivity, for example melanoma and renal cell cancers are considered more radioresistant. Radiosensitivity is determined by the intrinsic radiobiological properties of tumours, which include vascularisation and oxygenation. Contrast Clearance Analysis (CCA)-MRI measures delayed contrast behaviour to offer a window into tumour vascularity. The CCA colour map shows areas of contrast accumulation (red), suggesting vascular damage, and rapid contrast clearance (blue), suggesting intact and increased vasculature. We aim to interrogate CCA-MRIs pre-stereotactic radiosurgery (SRS) for differences in contrast handling between BMs from different primaries. METHOD 10 patients, with 70 BMs, were included in the study. All had CCA-MRIs pre-SRS as part of their planning-MRIs. Radiotherapy-planning-CT scans were fused with the planning-post-contrast-T1-MRI, with consultant clinical oncologist-approved contoured targets, and the CCA-images. Threshold analysis was performed to obtain proportions of red and blue within the enhancing areas of each tumour. RESULTS There was a significant difference in the proportion of blue between BMs from different primaries (p=0.0294). In pairwise-comparisons, only the difference between lung and renal was significant (mean difference 37.65%, p=0.0390). The difference between the proportion of red was also significant overall (p=0.0084) (Figure 2). In pairwise comparisons, renal was significantly different from lung, breast and melanoma (mean difference 12.65%, p=0.0161; mean difference 12.97%, p=0.0154; and mean difference 11.29%, p=0.0169, respectively). CONCLUSION This study offers a novel insight into the vascularity of BMs from different primaries. Further research to explore if these findings can explain differential SRS outcomes is underway.

Rare Encounter: A Study of Oral Cavity Kaposi Sarcoma in Two Cases

Abstract Introduction/Objective Kaposi Sarcoma (KS) of the oral cavity, is an unusual vascular endothelial neoplasm and is the most common malignancy affecting the skin and internal organs in patients with AIDS. The tumor is caused by Human herpesvirus 8 (HHV-8). It rarely metastasizes and can be treated and totally cured by treating the AIDS disease. The oral cavity may be the only/ first site of KS, and therefore, is important in the diagnosis. The lesions present as multiple red-purple macules that develop into plaques or nodules. The hallmark microscopic features are spindle cell proliferation and irregular small, vascular slits, which often run parallel to the epithelium, as well as extravasated RBCs, with hemosiderin deposition and hyaline globules in 50% of lesions. HHV-8 nuclear staining is positive in all cases, which is crucial to differentiate it from other conditions with positivity for spindled cell markers: CD34, CD31, ERG, and FVIII R. The tumor can also be positive for lymphatic-specific markers (D2-40, LYVE-1, VEGFR3, and PROX1) Methods/Case Report We reviewed retrospectively archived cases from our TUH oral pathology database with available H&E slides diagnosed for Kaposi sarcoma between 2013 – 2023. We retrieved two confirmed cases, and we reviewed the slides and clinical information. Results (if a Case Study enter NA) Data were colleceted and analysed. Conclusion Incorporating Kaposi sarcoma into the differential diagnosis of pigmented red-purple vascular lesions in the oral cavity is of paramount importance. Detection of Kaposi sarcoma in this region bears significant prognostic implications, often serving as an initial sign of Kaposi sarcoma and indicating HIV infection. Lesions typically localize on the palate and gingiva. Heightened awareness of this clinical entity is crucial for facilitating early detection and treatment with antiretroviral drugs. Furthermore, the differential diagnosis for lesions with similar clinical presentations encompasses a broad spectrum, including benign conditions such as pyogenic granuloma, hemangioma, bacillary angiomatosis, and even granulation issue, as well as malignant tumors like angiosarcoma. It is noteworthy that considering Kaposi sarcoma in this context prompts pathologists to prioritize ordering stains for HHV-8. This diagnostic approach is supported by the exceptional sensitivity and specificity of HHV-8 stains, which exhibit 99% sensitivity and 100% specificity for diagnosing Kaposi sarcoma, while consistently yielding negative results in all other entities within the differential diagnosis.

Pseudomyogenic Hemangioendothelioma: A Case Report of a Rare Tumor with Unusual Presentation

Abstract Introduction/Objective Pseudomyogenic hemangioendothelioma (PHE) is an extremely rare neoplasm recently categorized by the World Health Organization (WHO) as an intermediate-grade vascular soft tissue tumor affecting young adults. While most documented cases exhibit local aggressiveness, we present a case with unusual presentation characterized by multiple pelvic and femoral lytic bone lesions associated with documented liver metastases. Methods/Case Report A mid-forties female presented with progressive left hip pain persisting for 2 weeks. Radiological assessments showed multiple lytic lesions in the left superior pubic ramus, right iliac wing, and left greater trochanter with associated pathologic fractures and soft tissue involvement. Additionally, multiple indeterminate hepatic and splenic hypodensities were noted. Histologic examination of the bone and liver biopsies revealed a neoplasm composed of spindled and epithelioid cells with hyperchromatic nuclei and eosinophilic cytoplasm. The neoplastic cells are arranged haphazardly and in short fascicles within a fibromyxoid stroma or sinusoidal spaces (in the liver) associated with scattered acute and chronic inflammation. Frequent mitoses are noted; however, no necrosis was identified. Tumor cells were positive for CD31, ERG, FOSB with equivocal staining for pankeratin and CK8/18. The top differential consideration was epithelioid hemangioendothelioma (EHE); however, sarcoma fusion next-generation sequencing panel exhibited features of a vascular neoplasm with WWTR1-FOSB, favoring PHE. Results (if a Case Study enter NA) NA Conclusion Pseudomyogenic hemangioendothelioma is a rare tumor that is prone for local recurrence and usually affect young adults (mean age: 30 years). Metastases are uncommon. To the best of our knowledge, we report a case of PHE with unusual presentation of early metastases to liver and possibly the spleen and highlights the complexity of PHE diagnosis.

Histology-specific clinical trial of lenvatinib and pembrolizumab in patients with sarcoma.

Survival of patients with metastatic sarcoma remains poor, and there is pressing need for new therapies. Most sarcoma subtypes are not responsive to immune checkpoint inhibition alone. Lenvatinib, a multi-receptor tyrosine kinase inhibitor targeting tumor vasculature, has immunomodulatory activity that contributes to its antitumor effects. Therefore we hypothesized that combination of lenvatinib and pembrolizumab would lead to improved clinical outcomes in patients with sarcoma. This was an open-label, single-arm study of lenvatinib and pembrolizumab in the following cohorts A: leiomyosarcoma, B: undifferentiated pleomorphic sarcoma (UPS), C: vascular sarcomas (angiosarcoma and epithelioid hemangioendothelioma), D: synovial sarcoma or malignant peripheral nerve sheath tumor (MPNST), and E: bone sarcomas (osteosarcoma and chondrosarcoma). The primary endpoint was best overall response (BOR) rate documented by RECIST v1.1 by 27 weeks in each cohort, with a threshold of ≥2 responses among 10 patients. Secondary endpoints included progression-free survival, overall survival, duration of response and safety. Forty-six patients were evaluable for the primary endpoint which was met in the UPS and MPNST/synovial cohorts (BOR rates by 27 weeks of 25% and 30%,respectively). There were 7 partial responses overall with additional responses noted in angiosarcoma and osteosarcoma. Treatment-related adverse events of any grade, and Grade 3 or higher, occurred in 50/51 (98%) and 29/51 (57%) of patients respectively. We observed durable responses in MPNST, synovial sarcoma and osteosarcoma. Patients with UPS and angiosarcoma also responded. Further exploration of this approach is warranted to confirm activity and determine optimal dosing schedules.

Case Report of Rectosigmoid Vascular Malformation

Abstract Introduction/Objective Gastrointestinal (GI) vascular malformations and hemangiomas, although infrequently encountered, can present with similar clinical symptoms as other more common causes of chronic hematochezia, such as hemorrhoids or inflammatory bowel disease (IBD, ex. Crohn’s disease, ulcerative colitis). Whereas hemangiomas are benign vascular tumors that grow quickly and often involute, vascular malformations consist of abnormal vasculature that grow in size as the individual ages without regression. Gastrointestinal vascular malformations can result in pain secondary to applied pressure on nearby tissues/organs and induce a chronic anemic state secondary to ongoing hematochezia. As surgery or sclerotherapy can often treat the condition, proper diagnosis is critical as it can impact treatment and quality of life. Among GI vascular malformations, rectosigmoid vascular malformations are uncommon, making up 5% of lower limb vascular malformations examined in recent published literature. In this case report, we highlight a case of rectosigmoid vascular malformation. Methods/Case Report A 41-year-old female, initially treated for inflammatory bowel disease (IBD), presents with multiple bloody bowel movements a day accompanied by nausea secondary to chronic proctosigmoiditis refractory to medications traditionally used in IBD: mesalamine derivatives, systemic corticosteroid, and biologics. While colonoscopy demonstrated some features suggestive of ulcerative colitis, CT and MR enterography showed severe rectal wall thickening with phleboliths, which was unchanged over many years, suggestive of a vascular malformation such as a hemangioma. Following rectosigmoid colon resection, a diagnosis of a 9 cm rectosigmoid vascular malformation was made, showing extensive bowel wall involvement by the malformed vasculature. On follow-up, the patient is doing well, and her symptoms have completely resolved. Results (if a Case Study enter NA) NA Conclusion Vascular malformations can be classified into various subtypes (capillary, venous, arterial, lymphatics, etc), found throughout the body, and vary in size. Our case consists of a mixed nature (artery, vein, and lymphatics), notable size (9.0 cm in greatest dimension) with extensive bowel wall involvement, and an unusual location (rectosigmoid region). This case represents an uncommon presentation of this entity, which appears to be clinically challenging. Though uncommon, this diagnosis should be on the differential of unusual etiologies of overt lower GI bleeding.

Kaposiform haemangioendothelioma: ultrasonographic features and risk factors for the Kasabach-Merritt phenomenon.

Kaposiform hemangioendothelioma (KHE) is a rare, locally aggressive vascular tumor with high morbidity and mortality. The aim of this study was to evaluate ultrasonographic findings associated with KHE.The clinical and ultrasonographic findings of a cohort of 64 cases with pathologically proven KHE were retrospectively reviewed and analyzed between November 2014 and February 2021. Two subtypes were divided according to the presence or absence of the Kasabach-Merritt phenomenon (KMP). The KMP risk factors in patients with KHE were analyzed statistically.Among the 64 cases of KHE, 43 (67.2%) were accompanied by KMP. There was a positive correlation between the appearance of KMP and tumor size. KHEs had an increased risk of developing KMP if the lesions measured were >6 cm and if they belonged to the deep or mixed subtype. On ultrasonography, all KHE lesions were heterogeneous, and 81.3% were hypoechoic; 93.8% of KHEs exhibited ill-defined margins, 68.7% had strands branching into the adjacent tissue, and 84.4% presented marked hypervascularity. Elastography showed that central hypoechogenic lesion areas were hard, and surrounding hyperechogenic lesion areas were soft.KHEs can occur in different parts of childrens' bodies. On ultrasonography, the main findings are heterogeneous low erosions, indistinct margins, branching strangulation into adjacent tissues, and obvious hypervascularity. Patients with lesions larger than 6 cm or belonging to deep or mixed subtypes (musculoskeletal infiltrates) are at risk for developing KMP, and clinicians should be vigilant.

A Rare Case Report of Cervical Hemangiomatous Polyp.

The uterine cervix is a rare site for cavernous hemangiomas. Cervical hemangiomas are slow-growing tumors with characteristic histological findings, including dilated vessels with increased endothelial cells. Although their pathophysiology remains unclear, hormones are believed to play an important role in the development of these vascular tumors. They may be asymptomatic due to their small size, but they can cause gynecological and obstetrical complications, including abnormal uterine bleeding and impaired fertility. Due to their small size, conservative treatment is the first line of management. Hysterectomy is considered for refractory cases or for patients who are not of childbearing age. We present a case report of a 62-year-old postmenopausal female with postmenopausal bleeding and a polypoid mass hanging over the anterior cervical wall through its stalk. The surgical biopsy revealed no signs of neoplastic changes, with the only notable finding being a polypoidal lesion representing a cavernous hemangiomatous cervical polyp.

Plasmodium infection downregulates hypoxia‑inducible factor 1α expression to suppress the vascularization and tumorigenesis of liver cancer.

Liver cancer is characterized by hypervascularization. Anti-angiogenic agents may normalize the tumor vasculature and improve the efficacy of other treatments. The present study aims to investigate the anti-angiogenic effect of Plasmodium infection in a mouse model of implanted liver cancer cells. HepG2 cells were injected into the left liver lobe of nude mice as a model of in situ hepatic tumorigenesis. Plasmodium yoelii parasitized erythrocytes were administered in the animal model of liver cancer to introduce Plasmodium infection. The tumor growth and microvascular density were determined in the presence or absence of Plasmodium infection. The expression levels of hypoxia-inducible factor 1α (HIF-1α) and angiogenesis-related factors were evaluated using western blotting and reverse transcription-quantitative PCR analysis. The results demonstrated that Plasmodium infection suppressed tumor growth and vascularization in the mouse model of implanted HepG2 cells. Plasmodium parasites reduced the expression of pro-angiogenic factors (vascular endothelial growth factor A and angiopoietin 2), matrix metalloproteinases [(MMP)2 and MMP9] and inflammatory cytokines [tumor necrosis factor α, interleukin 6 (IL)-6) and IL-1β] in both hepatic and tumor tissues. HIF-1α was downregulated in both hepatic and tumor tissues upon Plasmodium infection, and HIF-1α overexpression rescued angiogenesis and tumor growth under the condition of Plasmodium infection. In conclusion, the results of the present study demonstrated the anti-angiogenic and anti-tumorigenic effects of Plasmodium infection on liver cancer through downregulating HIF-1α expression, indicating that Plasmodium parasites could be developed as an intervention strategy to restrain neo-angiogenesis in liver cancer.

Kaposi Sarcoma as a Possible Cutaneous Adverse Effect of ChAdOx1 nCov-19 Vaccine: A Case Report

The COVID-19 pandemic prompted the rapid development of vaccines, including the ChAdOx1 nCov-19 (AstraZeneca) vaccine. While effective, adverse effects have been reported, including cutaneous manifestations. Kaposi sarcoma (KS), a vascular tumor linked to Kaposi sarcoma herpesvirus/human herpesvirus 8 (HHV-8), has seen increased detection during the pandemic. This study reports a case of classic cutaneous KS in a 79-year-old male following the first dose of the ChAdOx1 nCov-19 vaccine, without prior SARS-CoV-2 infection. The patient developed multiple reddish-blue papules on his legs and feet, confirmed as KS through histopathology. Treatment included radiotherapy and sequential chemotherapy with Doxorubicin. The potential reactivation of latent HHV-8 by the vaccine is explored through mechanisms involving the SARS-CoV-2 spike protein and adenovirus vector, which may induce immune responses and inflammatory pathways. Although establishing a direct causal link remains challenging, the case highlights the need for vigilance regarding KS reactivation post-vaccination. Further large-scale studies are warranted to elucidate the relationship between COVID-19 vaccines and latent virus reactivation, ensuring comprehensive safety assessments and informed public health decisions.

Dynamic susceptibility contrast‑enhanced perfusion magnetic resonance imaging parameters for predicting MGMT promoter methylation and prognostic value in newly diagnosed patients with glioblastoma.

O6-methylguanine DNA methyltransferase (MGMT) promoter methylation is an important clinical biomarker of newly diagnosed glioblastoma. Previous radiological studies using dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) perfusion have aimed to predict MGMT methylation status non-invasively in gliomas with radiological characteristics. The possibility of predicting MGMT methylation status using DSC-MRI perfusion with a radiological approach remains controversial. The present study aimed to evaluate the usefulness of MRI perfusion parameters as non-invasive markers to predict MGMT methylation status and prognosis in newly diagnosed glioblastoma patients. Thus, 50 patients with histologically confirmed primary glioblastoma, IDH-wildtype who underwent tumor resection at Osaka University Hospital (Suita, Japan) between January 2017 and January 2023 were included in this study. The mean cerebral blood volume (CBV) ratio (rCBV) and cerebral blood flow (CBF) ratio (rCBF) for tumors with MGMT methylation (mean rCBV:2.09 and mean rCBF:3.08) were significantly higher compared with those for tumors without MGMT methylation (mean rCBV:1.33 and mean rCBF:1.85; P<0.05). While patients with MGMT methylation had longer progression-free survival (PFS) compared with those without MGMT methylation (P<0.05), there was no significant difference in OS with or without MGMT methylation (P=0.06). By contrast, there was no association between MRI perfusion parameters and OS or PFS in patients with glioblastoma. Furthermore, the association between CBV, CBF, MGMT promotor methylation status, OS, and PFS were explored. There was no significant prognostic difference between low vascularity tumors (rCBV <1.3 or rCBF <1.8) with or without MGMT methylation. On the other hand, high vascularity tumors (rCBF ≥1.8) with MGMT promotor methylation were associated to longer OS and PFS compared with those without. However, there was no association between MGMT methylation status and OS or PFS in patients with high rCBV (rCBV ≥1.3). The present study indicated that CBV and CBF could be used to predict the MGMT methylation status in glioblastomas. However, the prognostic value of tumor vascularity and MGMT methylation status may be limited.

Fever of Unknown Origin in Children

Fever is a common symptom in children and fever of unknown origin (FUO) is not uncommon in paediatric age group. The FUO remains a challenging clinical problem and is an important cause of morbidity and mortality in children. These undifferentiated prolonged fevers need step-wise approach for diagnosis. Details and proper history taking, thorough serial physical examination, critical analysis of sign-symptoms diary and investigation reports are crucial to get a clue that led to the diagnosis. Though in some aspect more concerned with developing countries data, this article is based on reviewing of published papers from both developed and developing countries. Worldwide infection remains the most common cause of FUO in children, followed by collagen vascular diseases, neoplasm, miscellaneous diseases and undiagnosed illnesses. Indiscriminate use of antimicrobials and other medications may mask the real diagnosis. Awareness of primary-level healthcare providers about the cause and logical management approach of pediatric FUO is important for better outcome. Journal of Monno Medical College December, 2023; 9 (2):78-84

Multifunctional nanoparticles potentiate in-situ tumor vaccines via reversing insufficient Photothermal therapy by disrupting tumor vasculature

Photothermal therapy can trigger immunogenic cell death and release personalized in-situ tumor vaccine, activating immune responses to eliminate systemic tumors beyond the irradiated zone. However, the immune response of the in-situ tumor vaccines is often undermined by the residual tumor cells and their induced immunosuppressive tumor microenvironment (TME), which is attributed to insufficient photothermal effects stemming from the limited accumulation of photosensitizers. To overcome these limitations, we developed multi-functional nanoparticles (VI@Gd-NPs) that integrate a tumor vasculature-specific disrupting agent (Vadimezan, Phase III clinical drug), a photosensitizer (Indocyanine Green, ICG), and a magnetic resonance imaging contrast agent (Gadolinium, Gd) through chemical self-assembly. By selectively disrupting the tumor vasculature, these nanoparticles enhance the intratumoral delivery of photosensitizers (ICG and blood cells), and Gd. With the guidance of Gd-enhanced MRI, the improved delivery facilitates comprehensive photothermal ablation and regulates the TME, further initiating the in-situ tumor vaccine. Notably, this approach significantly enhances anti-tumor immune responses, improves survival rates, and reduces tumor recurrence and metastasis in various animal models. Moreover, depleting CD8+ T cells reverses these therapeutic benefits, highlighting the critical role of adaptive T cell immunity. Therefore, the VI@Gd-NPs treatment holds great potential for reigniting the in-situ tumor vaccine of photothermal therapy.

RNA Nanotechnology for Codelivering High-Payload Nucleoside Analogs to Cancer with a Synergetic Effect.

Nucleoside analogs are potent inhibitors for cancer treatment, but the main obstacles to their application in humans are their toxicity, nonspecificity, and lack of targeted delivery tools. Here, we report the use of RNA four-way junctions (4WJs) to deliver two nucleoside analogs, floxuridine (FUDR) and gemcitabine (GEM), with high payloads through routine and simple solid-state RNA synthesis and nanoparticle assembly. The design of RNA nanotechnology for the co-delivery of nucleoside analogs and the chemotherapeutic drug paclitaxel (PTX) resulted in synergistic effects and high efficacy in the treatment of Triple-Negative Breast Cancer (TNBC). The 4WJ-drug complexes were confirmed to have efficient tumor spontaneous targeting and no toxicity because the motility of RNA nanoparticles has been previously shown to enable these RNA-drug complexes to spontaneously accumulate in tumor blood vessels. The negative charge of RNA enables those RNA complexes that are not targeted to tumor vasculature to circulate in the blood and enter the urine through the kidney glomerulus, without accumulating in organs, therefore being nontoxic. Drug incorporation into RNA 4WJ can be precisely controlled with a defined loading amount, location, and ratio. The incorporation of nucleoside analogs into 4WJ only requires one step using nucleoside analogue phosphoramidites during solid-phase RNA synthesis, without the need for additional conjugation and purification processes.

Stimulating Soluble Guanylyl Cyclase with the Clinical Agonist Riociguat Restrains the Development and Progression of Castration-Resistant Prostate Cancer.

Castration-resistant prostate cancer (CRPC) is incurable and fatal, making prostate cancer the second-leading cancer-related cause of death for American men. CRPC results from therapeutic resistance to standard-of-care androgen deprivation (AD) treatments, through incompletely understood molecular mechanisms, and lacks durable therapeutic options. Here, we identified enhanced soluble guanylyl cyclase (sGC) signaling as a mechanism that restrains CRPC initiation and growth. Patients with aggressive, fatal CRPC exhibited significantly lower serum levels of the sGC catalytic product cyclic GMP (cGMP) compared to their castration-sensitive stage. In emergent castration-resistant cells isolated from castration-sensitive prostate cancer (CSPC) populations, the obligate sGC heterodimer was repressed via methylation of its beta subunit. Genetically abrogating sGC complex formation in CSPC cells promoted evasion of AD-induced senescence and concomitant castration-resistant tumor growth. In established castration-resistant cells, the sGC complex was present but in a reversibly oxidized and inactive state. Subjecting CRPC cells to AD regenerated the functional complex, and co-treatment with riociguat, an FDA-approved sGC agonist, evoked redox stress-induced apoptosis. Riociguat decreased castration-resistant tumor growth and increased apoptotic markers, with elevated cGMP levels correlating significantly with lower tumor burden. Riociguat treatment reorganized tumor vasculature and eliminated hypoxic tumor niches, decreasing CD44+ tumor progenitor cells and increasing the radiosensitivity of castration-resistant tumors. Thus, this study showed that enhancing sGC activity can inhibit CRPC emergence and progression through tumor cell-intrinsic and extrinsic effects. Riociguat can be repurposed to overcome CRPC, with noninvasive monitoring of cGMP levels as a marker for on-target efficacy.

DNA demethylation triggers cell free DNA release in colorectal cancer cells

BackgroundLiquid biopsy based on cell-free DNA (cfDNA) analysis holds significant promise as a minimally invasive approach for the diagnosis, genotyping, and monitoring of solid malignancies. Human tumors release cfDNA in the bloodstream through a combination of events, including cell death, active and passive release. However, the precise mechanisms leading to cfDNA shedding remain to be characterized. Addressing this question in patients is confounded by several factors, such as tumor burden extent, anatomical and vasculature barriers, and release of nucleic acids from normal cells. In this work, we exploited cancer models to dissect basic mechanisms of DNA release.MethodsWe measured cell loss ratio, doubling time, and cfDNA release in the supernatant of a colorectal cancer (CRC) cell line collection (N = 76) representative of the molecular subtypes previously identified in cancer patients. Association analyses between quantitative parameters of cfDNA release, cell proliferation, and molecular features were evaluated. Functional experiments were performed to test the impact of modulating DNA methylation on cfDNA release.ResultsHigher levels of supernatant cfDNA were significantly associated with slower cell cycling and increased cell death. In addition, a higher cfDNA shedding was found in non-CpG Island Methylator Phenotype (CIMP) models. These results indicate a positive correlation between lower methylation and increased cfDNA levels. To explore this further, we exploited methylation microarrays to identify a subset of probes significantly associated with cfDNA shedding and derive a methylation signature capable of discriminating high from low cfDNA releasers. We applied this signature to an independent set of 176 CRC cell lines and patient derived organoids to select 14 models predicted to be low or high releasers. The methylation profile successfully predicted the amount of cfDNA released in the supernatant. At the functional level, genetic ablation of DNA methyl-transferases increased chromatin accessibility and DNA fragmentation, leading to increased cfDNA release in isogenic CRC cell lines. Furthermore, in vitro treatment of five low releaser CRC cells with a demethylating agent was able to induce a significant increase in cfDNA shedding.ConclusionsMethylation status of cancer cell lines contributes to the variability of cfDNA shedding in vitro. Changes in methylation pattern are associated with cfDNA release levels and might be exploited to increase sensitivity of liquid biopsy assays.

From Cancer to Immune Organoids: Innovative Preclinical Models to Dissect the Crosstalk between Cancer Cells and the Tumor Microenvironment

Genomic-oriented oncology has improved tumor classification, treatment options, and patient outcomes. However, genetic heterogeneity, tumor cell plasticity, and the ability of cancer cells to hijack the tumor microenvironment (TME) represent a major roadblock for cancer eradication. Recent biotechnological advances in organotypic cell cultures have revolutionized biomedical research, opening new avenues to explore the use of cancer organoids in functional precision oncology, especially when genomics alone is not a determinant. Here, we outline the potential and the limitations of tumor organoids in preclinical and translational studies with a particular focus on lung cancer pathogenesis, highlighting their relevance in predicting therapy response, evaluating treatment toxicity, and designing novel anticancer strategies. Furthermore, we describe innovative organotypic coculture systems to dissect the crosstalk with the TME and to test the efficacy of different immunotherapy approaches, including adoptive cell therapy. Finally, we discuss the potential clinical relevance of microfluidic mini-organ technology, capable of reproducing tumor vasculature and the dynamics of tumor initiation and progression, as well as immunomodulatory interactions among tumor organoids, cancer-associated fibroblasts (CAFs) and immune cells, paving the way for next-generation immune precision oncology.

The Impact of Combined Chemotherapy and Intra-Tumoural Injection of Phosphorus-32 Microparticles on Vascularity in Locally Advanced Pancreatic Carcinoma.

Poor intra-tumoural vascularity contributes to a lack of response to chemotherapy in pancreatic cancers. Preliminary data suggest that the addition of endoscopic ultrasound (EUS)-guided intra-tumoural injection of phosphorus-32 (32P) microparticles to standard chemotherapy is potentially beneficial in locally advanced pancreatic cancer (LAPC). We aimed to assess changes in pancreatic tumour vascularity following 32P implantation, using contrast-enhanced EUS (CE-EUS). This was a prospective single-centre trial from January 2022 to 2024 of patients with unresectable, non-metastatic LAPC undergoing standard FOLFIRINOX chemotherapy and 32P implantation. We performed CE-EUS pre-implantation after two chemotherapy cycles and 4 and 12 weeks after implantation. Time-intensity curves were analysed for 90 s after IV contrast bolus to ascertain peak intensity and intensity gain. A total of 20 patients underwent 32P implantation, with 15 completing 12-week follow-up. The technical success of 32P implantation was 100%. The median primary tumour size reduced from 32 mm (IQR 27.5-38.75) pre-implantation to 24 mm (IQR 16-26) 12 weeks post-implantation (p < 0.001). Five patients (25%) had tumour downstaging, and four underwent resections. The baseline (pre-implantation, post-chemotherapy) median intensity gain of contrast enhancement within the tumour was 32.15 (IQR 18.08-54.35). This increased to 46.85 (IQR 35.05-76.6; p = 0.007) and 66.3 (IQR 54.7-76.3; p = 0.001) at 4 weeks and 12 weeks post-implantation, respectively. Over a median follow-up of 11.2 months (IQR 7.8-12.8), 15/20 (75%) of patients remained alive, with 3/20 (15%) demonstrating local disease progression. Overall survival was not significantly different between patients with or without an increased intensity of 10 a.u. or more at 12 weeks post-implantation. This is the first clinical study to demonstrate treatment-induced increased vascularity within pancreatic primary tumours, which followed 32P implantation and FOLFIRINOX chemotherapy. Larger comparative trials are warranted.

Towards a framework for predicting immunotherapy outcome: a hybrid multiscale mathematical model of immune response to vascular tumor growth.

Studying tumor immune microenvironment (TIME) is pivotal to understand the mechanism and predict the outcome of cancer immunotherapy. Systems biology mathematical models can consider and control various factors of TIME and therefore explore the anti-tumor immune response meticulously. However, the role of tumor vasculature in the recruitment of T cells and the mechanism of T cell migration through TIME have not been studied comprehensively. In this work, we developed a hybrid discrete-continuum multi-scale model to study TIME. The mathematical model includes angiogenesis and T cell recruitment via tumor vasculature. Moreover, solid tumor growth, vascular growth and remodeling, interstitial fluid flow, hemodynamics, and blood rheology are all considered in the model. In addition, different aspects of T cells, including their migration, proliferation, subtype conversion, and interaction with tumor cells are thoroughly included. The model reproduces spatiotemporal distribution of tumor infiltrating T cells that mimics histopathological patterns. Furthermore, TIME model robustly recapitulates different phases of tumor immunoediting. We also examined a number of biomarkers to predict the outcome of immune checkpoint blockade (ICB) treatment. The results demonstrated that although tumor mutational burden (TMB) may predict non-responders to ICB, a combination of different biomarkers is essential to predict the majority of the responders. Based on our results, the ICB response rate varies significantly from 28 to 89% depending on the values of different parameters, even in the cases with high TMB.

Sirolimus for kaposiform hemangioendothelioma: Potential mechanisms of action and resistance.

Kaposiform hemangioendotheliomas (KHEs) are vascular tumors that are considered borderline or locally aggressive and may lead to lethal outcomes. Traditional therapies, such as surgery and embolization, may be insufficient or technically impossible for patients with KHE. Sirolimus (or rapamycin), a specific inhibitor of mechanistic target of rapamycin, has recently been demonstrated to be very useful in the treatment of KHEs. Here, we highlight recent substantial progress regarding the effects of sirolimus on KHEs and discuss the potential mechanisms of action of sirolimus in treating this disease. The prevention of platelet activation and inflammation, along with antiangiogenic effects, the inhibition of lymphangiogenesis, the attenuation of fibrosis, or a combination of all these effects, may be responsible for the therapeutic effects of sirolimus. In addition, the mechanism of sirolimus resistance in some KHE patients is discussed. Finally, we review the somatic mutations that have recently been identified in KEH lesions, and discuss the potential of novel therapeutic targets based on these further understandings of the cellular and molecular pathogenesis of KHE.