Tumor Blood Vessels Research Articles

Abstract C039: The impact of antiangiogenic therapy on blood vessels and CD8 infiltration in renal cancer metastases is space, time, site, dose, and drug dependent

Abstract Clear cell renal cell carcinoma (ccRCC) is the most prevalent renal neoplasm, with bone as a major site for distant spread in 35% to 40% of the patients. These metastases are typically osteolytic, resistant to treatments, hence result in a variety of skeletal-related complications strongly contributing to mortality. A key feature of ccRCC is the loss of function of the von Hippel–Lindau (VHL) protein leading to extensive angiogenesis. Consequently, different anti-angiogenic tyrosine kinase inhibitors (TKIs) are used as the first or subsequent line of treatment for these patients as single agents or in combination with immune checkpoint inhibitors. However, limited data about their efficacy in bone metastasis is available, and their impact on the immune infiltrate, including effector CD8 cells, is unclear. We hypothesized that TKIs, by inhibiting angiogenesis, significantly reprogram the microenvironment and limit immune infiltration in space, time, dose, and drug dependent fashion. To test these hypotheses, we developed an immunocompetent mouse model of bone metastasis by orthotopical intratibial implantation of luciferase-GFP-positive mouse RENCA-VHL- cell line. Interestingly, intratibial injections gave rise to metastases in lungs, creating a unique opportunity to study two metastatic sites. Three different TKIs currently used in patients were tested and compared to control: axitinib (A), cabozantinib (C), and lenvantinib (L). Outcomes were monitored by macroscopic bioluminescence detection in vivo, 3D multiparametric spatial analysis of bones and lungs, in vivo, and ex vivo. Compared to control-treated mice, high doses of A, C, and L significantly reduced tumor progression in both tumor sites. Even though these TKIs are clinically considered equal, significant differences in their efficacy were noted. Spatial analysis of tumor cells and blood vessels showed a significant decrease in blood vessels formation in both an organ- and TKI-specific pattern over time. Additionally, the reduction of neo angiogenesis in treated tumors directly limited the infiltration of CD8 cells, which localized at the interface with tumor free bone/lung tissue. Interestingly, TKI dose reduction significantly improved CD8 infiltration, while controlling tumor size. TKI withdrawal, instead, led to rapid progression of tumor in both sites and significantly shortened mice survival. In conclusion, we established bone and lung metastatic models of ccRCC and characterized and compared the effects of three antiangiogenic TKIs on angiogenesis and CD8 infiltration. TKIs reduced tumor growth and progression, because of blood vessel formation inhibition. Furthermore, TKI treatment reduced the infiltration of effector T cells in tumors in a dose-dependent manner, an outcome that can have a major impact when TKIs are combined with immunotherapy, a preferential therapeutic regimen for ccRCC patients. Overall, we believe our studies provide important insights and efficacy predictions for innovative therapeutic applications in ccRCC bone metastatic patients. Citation Format: Stefan Maksimovic, Nina Costanza Boscolo, Ludovica La Posta, Matthew T. Campbell, Eleonora Dondossola. The impact of antiangiogenic therapy on blood vessels and CD8 infiltration in renal cancer metastases is space, time, site, dose, and drug dependent [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C039.

Unveiling the therapeutic potential of anthocyanin/cisplatin-loaded chitosan nanoparticles against breast and liver cancers

Abstract Background Liver and breast cancers are among the leading causes of cancer-related deaths worldwide, prompting researchers to seek natural anticancer agents and reduce chemotherapy side effects. Red beetroot (Beta vulgaris Linnaeus), rich in polyphenols and powerful antioxidants, has shown potential in cancer prevention. This study aimed to evaluate the impact of red beetroot-derived anthocyanin (Ant), Ant-loaded chitosan nanoparticles (Ant NPs), cisplatin (Cis), Cis-loaded chitosan (Cis NPs), and Cis + Ant-loaded chitosan NPs on human hepatoma HepG2 and breast adenocarcinoma MCF7 cell lines. Methods NPs preparation was evaluated by zeta potential, FTIR, and SEM. The cytotoxic, apoptotic, antioxidant, anti-inflammatory, anti-metastatic, and anti-angiogenic effects were assessed by MTT assay, qPCR, AO/EB staining, and flow cytometry. Results Treatment with Ant, Ant NPs, Cis, Cis NPs, and Cis + Ant NPs caused cytotoxicity in HepG2 and MCF7 with best effect in Cis-treated cells. The anticancer effects were attributed to mitochondrial-dependent apoptosis (with high Bax and low Bcl2 expression), chromatin disintegration, and cell cycle arrest in G2/M and S phases. All treatments inhibited migration by downregulating the migration-related gene MMP9 and upregulating the anti-migratory gene TIMP1 and decreased the angiogenesis-related gene VEGF and the inflammatory gene TNFα with best results in Cis NPs-treated cells. Interestingly, Ant, Ant NPs, and Cis + Ant NPs increased the antioxidant status (high GSH and upregulated expression of Nrf2 and OH-1) and decreased drug resistance-related MAPK1 and MDR1 genes compared to Cis and Cis NPs-treated cells. Conclusions Anthocyanin and cisplatin-loaded chitosan nanoparticles effectively combat breast and liver cancers by inducing cancer cell apoptosis, enhancing antioxidant defenses, and reducing inflammation. They also inhibit tumor spread and blood vessel formation through downregulation of MMP9 and VEGF, highlighting their therapeutic potential.

Iron-based MOF with Catalase-like activity improves the synergistic therapeutic effect of PDT/ferroptosis/starvation therapy by reversing the tumor hypoxic microenvironment.

Reversing the hypoxic microenvironment of tumors is an important method to enhance the synergistic effect of tumor treatment. In this work, we developed the nanoparticles called Ce6@HGMOF, which consists of a photosensitizer (Ce6), glucose oxidase (GOX), chemotherapy drugs (HCPT) and an iron-based metal-organic framework (MOF). Ce6@HGMOF can consume glucose in tumor cells through "starvation therapy", cut off their nutrition source, and produce gluconic acid and hydrogen peroxide (H2O2). Utilizing this feature, Ce6@HGMOF can produce oxygen through catalase-like catalytic activity, thereby reversing the hypoxic microenvironment of tumors. This strategy of changing the hypoxic environment can help to slow down the growth of tumor blood vessels and improve the drug-resistant microenvironment to some extent. Meanwhile, increasing the supply of oxygen can enhance the effect of photodynamic therapy (PDT) and enhance the oxidative stress damage caused by reactive oxygen species (ROS) in tumor cells. On the other hand, cancer cells usually produce higher levels of glutathione (GSH) to adapt to high oxidative stress and protect themselves. The Ce6@HGMOF we designed can also consume GSH and induce ferroptosis of tumor cells through Fenton reaction with H2O2, while enhancing the effect of PDT. This innovative synergistic strategy, the combination of PDT/ferroptosis /starvation therapy, can complement each other and enhance each other. It has great potential as a powerful new anti-tumor paradigm in the future.

Clotting promotes glioma growth and infiltration through activation of focal adhesion kinase.

The tumor architecture of high-grade gliomas is shaped by tumor cell necrosis, invasive growth and the leakage of a fibrin-rich edema from poorly organized tumor blood vessels. Here, we demonstrate a marked upregulation of clot formation in the interstitial spaces of tumor tissues from patients with glioblastoma while tumor-free brain is essentially devoid of fibrin. The accumulation of fibrin in tumor interstitial spaces is functionally relevant as we demonstrate increased infiltration and growth of primary glioblastoma cells after embedding in a 3-dimensional matrix made of fibrin ex vivo. Additionally, we detected accelerated tumor growth after implanting glioblastoma cells together with clotted plasma in brains of immune deficient mice while glioblastoma development in clotting-deficient hemophilia mice was delayed. Glioblastoma growth correlated with the outgrowth of invadopodia and their adhesive interactions with the 3-dimensional clot matrix, which was mediated by integrins β1 and β3 and their common downstream target focal adhesion kinase (FAK). Knocking down FAK with CRISPR Cas9 caused an upregulation of p21/p27 cell cycle inhibitors, strong growth inhibition in cultured glioblastoma cells and sustained anti-tumorigenic effects in orthotopic glioblastoma xenografts in vivo. These results go hand in hand with genomic data from The Cancer Genome Atlas that indicate increased clotting activity and reduced patient survival in glioma subgroups with high integrin β1 and β3 expression. We therefore conclude that clotting in glioma interstitial spaces provides tumor cells with a potent proliferative stimulus that can be reversed by targeting the adhesive machinery of glioblastoma cells via inhibition of FAK.

Enhancing Tumor Targeted Therapy: The Role of iRGD Peptide in Advanced Drug Delivery Systems

Chemotherapy remains the primary therapeutic approach in treating cancer. The tumor microenvironment (TME) is the complex network surrounding tumor cells, comprising various cell types, such as immune cells, fibroblasts, and endothelial cells, as well as ECM components, blood vessels, and signaling molecules. The often stiff and dense network of the TME interacts dynamically with tumor cells, influencing cancer growth, immune response, metastasis, and resistance to therapy. The effectiveness of the treatment of solid tumors is frequently reduced due to the poor penetration of the drug, which leads to attaining concentrations below the therapeutic levels at the site. Cell-penetrating peptides (CPPs) present a promising approach that improves the internalization of therapeutic agents. CPPs, which are short amino acid sequences, exhibit a high ability to pass cell membranes, enabling them to deliver drugs efficiently with minimal toxicity. Specifically, the iRGD peptide, a member of CPPs, is notable for its capacity to deeply penetrate tumor tissues by binding simultaneously integrins ανβ3/ανβ5 and neuropilin receptors. Indeed, ανβ3/ανβ5 integrins are characteristically expressed by tumor cells, which allows the iRGD peptide to home onto tumor cells. Notably, the respective dual-receptor targeting mechanism considerably increases the permeability of blood vessels in tumors, enabling an efficient delivery of co-administered drugs or nanoparticles into the tumor mass. Therefore, the iRGD peptide facilitates deeper drug penetration and improves the efficacy of co-administered therapies. Distinctively, we will focus on the iRGD mechanism of action, drug delivery systems and their application, and deliberate future perspectives in developing iRGD-conjugated therapeutics. In summary, this review discusses the potential of iRGD in overcoming barriers to drug delivery in cancer to maximize treatment efficiency while minimizing side effects.

Synthesis of heavy-atom-free thienoisoindigo dye as near-infrared photosensitizer for type I photodynamic therapy and photoacoustic imaging

Thienoisoindigo (TIIG) has been extensively employed as promising building block of near-infrared (NIR) dyes and organic semiconductor materials. Herein, heavy-atom-free TIIG-based NIR dye TIIGTPA is reported as photosensitizer for combinational photodynamic and photothermal therapy and photoacoustic imaging (PAI). By introducing two methoxy-substituted triphenylamines as the rotors and electron donors at the periphery sites of the electron-deficient TIIG core, dye TIIGTPA featuring Donor-Acceptor-Donor (D-AD) structure is constructed with intensive NIR absorption. Through co-assembly with amphipathic F-127, water-soluble TIIGTPA NPs were prepared with good superoxide anion radical (O2-•) production and high photothermal conversion efficiency (PCE) of 59.0 % under 730 nm photoirradiation. Additionally, the excellent photothermal effect enabled a superior photoacoustic response for tumor blood vessel visualization through PAI. All results indicated the favorable potential of TIIGTPA NPs for PAI-mediated combinational phototherapy.

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.

Targeting ESM1 via SOX4 promotes the progression of infantile hemangioma through the PI3K/AKT signaling pathway.

Infantile hemangioma (IH) is the most prevalent benign vascular tumor in children, yet its pathogenesis remains incompletely understood. Research has established a strong association between SOX4 and tumor blood vessel formation. The objective of this study was to investigate the function and underlying mechanism of SOX4 in IH development with the aim of identifying novel therapeutic targets. We identified the transcription factor SOX4 associated with IH through RNA-seq screening of IH microtumors and validated it in IH tissues. The effect of SOX4 on the biological behavior of CD31+hemangioma-derived endothelial cells (HemECs) was investigated via in vitro cell experiments. In addition, RNA-seq analysis was performed on CD31+HemECs with low expression levels of SOX4, and the target genes of SOX4 were identified. Finally, the effect of SOX4 on tumor angiogenesis was further elucidated through 3D microtumor and animal experiments. SOX4 is highly expressed in IH tissues and promotes the proliferation, migration, and angiogenesis of CD31+HemECs. In addition, SOX4 binds to the endothelial cell-specific molecule 1 (ESM1) promoter to promote the progression of the PI3K/AKT signaling pathway. Finally, through IH 3D microtumor and animal experiments, SOX4 and ESM1 are shown to be tumorigenic genes that independently promote tumor progression. SOX4 plays a crucial role in the progression of IH, and the SOX4/ESM1 axis may serve as a novel biomarker and potential therapeutic target for IH.

Losartan rewires the tumor-immune microenvironment and suppresses IGF-1 to overcome resistance to chemo-immunotherapy in ovarian cancer.

Ovarian cancer (OvCa) is the most lethal of the gynecologic malignancies. Immune checkpoint inhibitors, which have revolutionized the treatment of multiple malignancies, have had limited efficacy in OvCa patients. This lack of effectiveness is partly due to the abnormal ovarian tumor microenvironment (TME), displaying a desmoplastic, highly fibrotic extracellular matrix. High extracellular matrix deposition leads to a buildup of compressive forces that cause tumor blood vessel collapse, reduced vessel perfusion, poor delivery of drugs, and compromised trafficking of cytotoxic T-cells to these tumors. Using two syngeneic OvCa models, we tested the effect of losartan, a widely prescribed anti-hypertensive drug, on reprogramming the TME and chemosensitizing the cancer cells. Losartan treatment (i) reprograms the TME leading to increased vascular perfusion, and thus enhances drug delivery and immune effector cell intratumoral infiltration and function; and (ii) rewires the OvCa cells by suppressing the IGF-1 signaling, resulting in enhanced chemosensitivity. As a result of the combined tumor and stromal effects, losartan treatment enhances the efficacy of chemo-immunotherapy in OvCa models. The safety and low cost ( < $1-2/day) of losartan warrant rapid translation of our findings to patients with OvCa.

HCC spatial transcriptomic profiling reveals significant and potentially targetable cancer-endothelial interactions.

HCC is a highly vascular tumor, and many effective drug regimens target the tumor blood vessels. Prior bulk HCC subtyping data used bulk transcriptomes, which contained a mixture of parenchymal and stromal contributions. We utilized computational deconvolution and cell-cell interaction analyses to cell type-specific (tumor-enriched and vessel-enriched) spatial transcriptomic data collected from 41 resected HCC tissue specimens. We report that the prior Hoshida bulk transcriptional subtyping schema is driven largely by an endothelial fraction, show an alternative tumor-specific schema has potential prognostic value, and use spatially paired ligand-receptor analyses to identify known and novel (LGALS9 tumor-HAVCR2 vessel) signaling relationships that drive HCC biology in a subtype-specific and potentially targetable manner. Our study leverages spatial gene expression profiling technologies to dissect HCC heterogeneity and identify heterogeneous signaling relationships between cancer cells and their endothelial cells. Future validation and expansion of these findings may validate novel cancer-endothelial cell interactions and related drug targets.

Exposed Phosphatidylserine as a Biomarker for Clear Identification of Breast Cancer Brain Metastases in Mouse Models.

Brain metastasis is the most common intracranial malignancy in adults. The prognosis is extremely poor, partly because most patients have more than one brain lesion, and the currently available therapies are nonspecific or inaccessible to those occult metastases due to an impermeable blood-tumor barrier (BTB). Phosphatidylserine (PS) is externalized on the surface of viable endothelial cells (ECs) in tumor blood vessels. In this study, we have applied a PS-targeting antibody to assess brain metastases in mouse models. Fluorescence microscopic imaging revealed that extensive PS exposure was found exclusively on vascular ECs of brain metastases. The highly sensitive and specific binding of the PS antibody enables individual metastases, even micrometastases containing an intact BTB, to be clearly delineated. Furthermore, the conjugation of the PS antibody with a fluorescence dye, IRDye 800CW, or a radioisotope, 125I, allowed the clear visualization of individual brain metastases by optical imaging and autoradiography, respectively. In conclusion, we demonstrated a novel strategy for targeting brain metastases based on our finding that abundant PS exposure occurs on blood vessels of brain metastases but not on normal brain, which may be useful for the development of imaging and targeted therapeutics for brain metastases.

Sialyl Lewis X decorated integrin α3 on small extracellular vesicles promotes metastasis of bladder cancer via enhancing vascular permeability.

The permeability of blood vessels plays a crucial role in the spread of cancer cells, facilitating their metastasis at distant sites. Small extracellular vesicles (sEVs) are known to contribute to the metastasis of various cancers by crossing the blood vessel wall. However, the role of abnormal glycoconjugates on sEVs in tumor blood vessels remains unclear. Our study found elevated levels of fucosyltransferase VII (FUT7) and its product sialyl Lewis X (sLeX) in muscle-invasive bladder cancer (BLCA), with high levels of sLeX promoting the growth and invasion of BLCA cells. Further investigation revealed that sLeX was enriched in sEVs derived from BLCA. sLeX-decorated sEVs increased blood vessel permeability by disrupting the tight junctions of human umbilical vein endothelial cells (HUVECs). Using the glycoproteomics approach, we identified integrin α3 (ITGA3) as a sLeX-bearing glycoprotein in BLCA cells and their sEVs. Mechanically, sLeX modification stabilized ITGA3 by preventing its degradation in lysosomes. sEVs carrying sLeX-modified ITGA3 can be effectively internalized by HUVECs, leading to a decrease in the expression of tight junction protein. Conversely, silencing ITGA3 in sLeX-decorated sEVs restored tight junction proteins and reduced blood vessel permeability by inhibiting the MAPK pathway. Moreover, sLeX-modification of ITGA3 at Asn 265 in HUVECs promoted occludin dephosphorylation at Ser/Thr residues, followed by inducing its importin α1-mediated nuclear translocation, which resulted in the disruption of tight junctions. Our findings suggest a potential strategy for disrupting the formation of a metastatic microenvironment and preventing the spread of malignant bladder cancer.

The impact of Kirsten rat sarcoma (KRAS) status on local tumor progression after surgical ablation of colorectal liver metastases

BackgroundKirsten rat sarcoma mutation was reported to adversely affect local tumor control after percutaneous ablation of colorectal liver metastasis. Nevertheless, the effect of Kirsten rat sarcoma mutation on surgical ablation has not been investigated in the literature. The aim of this study is to analyze the impact of Kirsten rat sarcoma mutation on local recurrence after surgical ablation of colorectal liver metastasis. MethodsThis was an institutional review board–approved study of patients who underwent surgical ablation of colorectal liver metastasis between 2005 and 2023 at a single center and underwent Kirsten rat sarcoma testing with ≥1 year follow-up. Local recurrence was analyzed using univariate Kaplan–Meier and multivariate Cox hazard models. ResultsA total of 163 patients with 424 lesions fulfilled inclusion criteria. Fifty (30.7%) patients received radiofrequency ablation and 113 (69.3%) patients received microwave ablation. Fifty-seven patients (32.2%) with 177 lesions were found to have a Kirsten rat sarcoma mutation. Patients with Kirsten rat sarcoma mutation had a larger number of tumors, percentage of posteriorly located tumors, and tumor burden score compared with those with wild-type Kirsten rat sarcoma. Nevertheless, there was no difference between the groups regarding local recurrence per lesion (15% vs 17%, respectively, P = not significant). Independent predictors of local recurrence included tumor size, ablation margin, and blood vessel proximity for radiofrequency ablation compared with tumor size and ablation margin for microwave ablation. ConclusionThere was no effect of Kirsten rat sarcoma mutations on local recurrence after surgical radiofrequency ablation or microwave ablation of colorectal liver metastasis in this study. Tumor size and ablation margin remained as independent predictors.

Relationship between the white blood cell count and some lipid profile parameters in cancer patients with myocardial infarction

Hokkaido University (Tsumita T, 2022) researchers found that endothelial cells accumulate low-density lipoproteins (LDL) in tumor blood vessels. At the same time, the endothelium carries out neutrophil chemotaxis, which perform an immunosuppressive function contributing to cancer progression.Aim. To search for the relationship between the white blood cell (WBC) count and some lipid profile parameters in cancer patients with myocardial infarction (MI).Material and methods. We examined 319 patients who were treated at Dzhanelidze Research Institute of Emergency Medicine in 2018-2023, which were divided into three groups: MI in combination with an active cancer — 132 patients (Group I), MI+cancer in history — 58 patients (Group II), MI without cancer — 129 patients (Group III). Following laboratory data used in routine practice were assessed: WBC count, relative neutrophil count, total cholesterol, low-density lipoproteins.Results. Cancer patients with MI are characterized by higher WBC and neutrophil count than in other samples However, the total cholesterol level was significantly lower in this sample, and the LDL level was not significantly different. Patients with MI and previous cancer occupied an intermediate position between groups I and III in terms of studied parameters.Conclusion. In general, data on the role of cholesterol levels in cancer patients are contradictory. In particular, some studies have shown that elevated cholesterol levels are a potential risk factor for cancer. In our study, as in a number of others, no significant associations were identified between elevated cholesterol levels and the presence of cancer. Our study is a step towards understanding the connection between the cholesterol concentration and the immune response in cancer patients with MI.

Lymphatic and blood vessels in parathyroid tumors: Immunohistochemical study with LYVE-1 and von Willebrand factor.

Parathyroid tumors exhibit distinct histopathological features that differentiate benign from malignant lesions. This study aimed to study characteristic distribution of lymphatic and blood vessels in normal parathyroid gland and parathyroid tumors to distinguish cancer from benign tumors. Immunohistochemical staining for lymphatic and blood vessels and parathyroid hormone was performed with parathyroid proliferating lesions including adenoma, multiglandular multiple adenomas, atypical tumor, and carcinoma. Lymphatic vessels were immunostained with lymphatic vessel endothelial receptor 1 (LYVE-1) and blood vessels were immunostained with von Willebrand factor (vWf). Normal parathyroid gland contained several round blood vessels with less linear lymphatic vessels. The less parathormone-immunostained adenomas weighing less than 2 g revealed larger blood vessels with perivascular small linear lymphatic vessels, and the larger adenomas contained proportionally larger blood vessels. Smaller multiglandular multiple adenomas were like smaller adenomas with less parathormone staining and contained larger, round blood vessels with perivascular small linear lymphatic vessels. Larger multiglandular multiple adenomas weighing more than 4 g and one atypical tumor contained nodular pattern consisted of alternating strongly parathormone-positive lobes and negative lobes with numerous, dilated blood vessels and perivascular linear lymphatic vessels. Both primary and metastatic carcinomas were strongly and diffusely positive for parathyroid hormone with numerous lymphatic and blood vessels at the invading margin. Thus, normal parathyroid has rich blood vessels which provide accessibility of minced tissues seeding for auto-transplantation. Immunostaining patterns of parathyroid hormone, lymphatic and blood vessels help to distinguish carcinoma from benign parathyroid proliferating lesions. The negative immunohistochemical staining for parafibromin will detect carriers of hyperparathyroidism-jaw tumor (HPT-JT) syndrome and would help in diagnosing parathyroid cancer in both HPT-JT carriers and sporadic patients.

Modified C-type natriuretic peptide normalizes tumor vasculature, reinvigorates antitumor immunity, and improves solid tumor therapies.

Deficit of oxygen and nutrients in the tumor microenvironment (TME) triggers abnormal angiogenesis that produces dysfunctional and leaky blood vessels, which fail to adequately perfuse tumor tissues. Resulting hypoxia, exacerbation of metabolic disturbances, and generation of an immunosuppressive TME undermine the efficacy of anticancer therapies. Use of carefully scheduled angiogenesis inhibitors has been suggested to overcome these problems and normalize the TME. Here, we propose an alternative agonist-based normalization approach using a derivative of the C-type natriuretic peptide (dCNP). Multiple gene expression signatures in tumor tissues were affected in mice treated with dCNP. In several mouse orthotopic and subcutaneous solid tumor models including colon and pancreatic adenocarcinomas, this well-tolerated agent stimulated formation of highly functional tumor blood vessels to reduce hypoxia. Administration of dCNP also inhibited stromagenesis and remodeling of the extracellular matrix and decreased tumor interstitial fluid pressure. In addition, treatment with dCNP reinvigorated the antitumor immune responses. Administration of dCNP decelerated growth of primary mouse tumors and suppressed their metastases. Moreover, inclusion of dCNP into the chemo-, radio-, or immune-therapeutic regimens increased their efficacy against solid tumors in immunocompetent mice. These results demonstrate the proof of principle for using vasculature normalizing agonists to improve therapies against solid tumors and characterize dCNP as the first in class among such agents.

Successful pancreatectomy after conversion-intended chemotherapy using gemcitabine and nab-paclitaxel for unresectable adenosquamous carcinoma of the pancreas: a case report

BackgroundAdenosquamous carcinoma of the pancreas (ASCP) accounts for only 1–4% of all pancreatic exocrine cancers and has a particularly poor prognosis. The efficacy of chemotherapy for ASCP remains unknown because of the small number of cases, and few studies have evaluated conversion-intended chemotherapy.Case presentationA 76-year-old woman was referred to our hospital because of epigastric pain and nausea. A preoperative contrast-enhanced multidetector row computed tomography (MDCT) scan revealed a 17 × 17 mm low-density tumor with an ill-defined margin at the arterial phase in the pancreatic head. The tumor involved the common hepatic artery, left hepatic artery bifurcated from the common hepatic artery, and gastroduodenal artery, and was in contact with the portal vein. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed an uptake in the pancreatic head but no evidence of distant metastasis. The tumor was diagnosed as an adenocarcinoma of the pancreatic head and staged unresectable because the common and left hepatic arteries were involved. Hence, the patient underwent seven courses of conversion-intended chemotherapy using gemcitabine and nab-paclitaxel for pancreatic ductal adenocarcinoma over 7 months. After chemotherapy, the tumor shrank to 10 × 10 mm on contrast-enhanced MDCT. Consequently, the boundary between the tumor and major vessels of the common and left hepatic arteries and the portal vein became clear, and the involvement of the arteries with the tumor was evaluated to be released. The contact of the tumor to the portal vein also reduced to less than half the circumference of the portal vein. FDG-PET showed decreased accumulation in the tumor. Hence, the tumor was judged resectable, and pancreaticoduodenectomy was performed. The tumor and major blood vessels were easily dissected and R0 resection was achieved. The patient experienced no major complications and was discharged on postoperative day 28. The tumor was revealed as ASCP via pathological examination. The patient is alive and recurrence-free seven months after surgery. This is the first report of successful R0 resection for an initially unresectable ASCP following conversion-intended chemotherapy using gemcitabine and nab-paclitaxel regimen. ConclusionsConversion-intended chemotherapy using gemcitabine and nab-paclitaxel regimen may be effective for ASCP.

Theoretical study of discriminative electroporation effect between tumor and normal blood vessels by high-frequency bipolar and traditional monopolar pulses

Theoretical study of discriminative electroporation effect between tumor and normal blood vessels by high-frequency bipolar and traditional monopolar pulses

30 Synergistic systematic analysis with fully human tissue models andin silico modeling of “copycats” reveals mechanisms of T cell suppression in clear cell renal cell carcinoma

Abstract Background Immune checkpoint-inhibitors have become a standard treatment for clear cell renal cell carcinoma (ccRCC). However, responses to checkpoint-inhibition are heterogeneous and many patients are resistant or eventually develop resistance. A better understanding of functional mechanisms governing immune responses in ccRCC is needed to identify biomarkers for therapeutic responses and to unravel novel therapeutic targets to overcome primary or acquired resistance to therapies. Methods We developed a fully human explant model derived from freshly resected ccRCC tissue (Fig. 1A). Our tissue explant model preserves all components of the tumor microenvironment including not only tumor cells, but also the immune cell compartment as well as tumor-stroma and -vasculature in culture (Fig. 1B). Following treatment with combined checkpoint-inhibition (Nivolumab plus Ipilimumab) or an anti-CCR5 inhibitor (Maraviroc), the tissue explants were analyzed by immunohistochemistry staining and multiplex cytokine profiling of 50 cytokines. Spatial and functional insights were incorporated in an agent-based in silico model (PhysiCell, Ghaffarizadeh et al., PLoS Comput. Biol., 2018) for unlimited exploration of functional cellular dynamics in the tumor microenvironment (Fig. 1D). Results Immunohistochemical analyses and cytokine profiling of ccRCC-tissue explants showed heterogeneous immune responses among different patients and indicated an impaired cytotoxic T cell response following checkpoint-inhibition (Fig. 1C). Spatial analyses of immune cell populations revealed clusters of CD8+ T cells and CD163+ macrophages localized closely to CD31+ endothelial cells. Further characterization of the tumor microenvironment revealed high CCR5-expression in the tumor, particularly on the tumor blood vessels (Fig. 1B). Treatment of the tissue explants with the anti-CCR5 inhibitor Maraviroc led to an increase of CD8+ T cells and cytotoxic cytokines (Granzyme B, IFNgamma, TNFalpha, IFNalpha2) in the tumor in comparison to checkpoint-inhibition (Fig. 1C). Spatial and functional information from cultured ccRCC-tissue explants were integrated into an agent-based in silico model of the ccRCC tumor microenvironment, which includes tumor cells, T cells, macrophages and endothelial cells (Fig. 1D). In silico simulation of different immune cell modulating treatment conditions showed an increase of T cells and cytotoxic cytokines upon blockade of the interaction between T cells with endothelial cells or macrophages (Fig. 1E). Conclusions Our combined ex vivo and in silico analyses provide evidence for immunosuppression in the ccRCC tumor microenvironment mediated by macrophages and endothelial cells. CCR5 was shown to be a potential target to overcome immune resistance to checkpoint-inhibition in ccRCC. Further characterization of immune cell compositions and functional mechanisms in the perivascular area is imperative to enhance therapeutic responses to immunotherapies for ccRCC.

Normalization of Snai1-mediated vessel dysfunction increases drug response in cancer

Blood vessels in tumors are often dysfunctional. This impairs the delivery of therapeutic agents to and distribution among the cancer cells. Subsequently, treatment efficacy is reduced, and dose escalation can increase adverse effects on non-malignant tissues. The dysfunctional vessel phenotypes are attributed to aberrant pro-angiogenic signaling, and anti-angiogenic agents can ameliorate traits of vessel dysfunctionality. However, they simultaneously reduce vessel density and thereby impede drug delivery and distribution. Exploring possibilities to improve vessel functionality without compromising vessel density in the tumor microenvironment, we evaluated transcription factors (TFs) involved in epithelial-mesenchymal transition (EMT) as potential targets. Based on similarities between EMT and angiogenic activation of endothelial cells, we hypothesized that these TFs, Snai1 in particular, might serve as key regulators of vessel dysfunctionality. In vitro, experiments demonstrated that Snai1 (similarly Slug and Twist1) regulates endothelial permeability, permissiveness for tumor cell transmigration, and tip/stalk cell formation. Endothelial-specific, heterozygous knock-down of Snai1 in mice improved vascular quality in implanted tumors. This resulted in better oxygenation and reduced metastasis. Notably, the tumors in Snai1KD mice responded significantly better to chemotherapeutics as drugs were transported into the tumors at strongly increased rates and more homogeneously distributed. Thus, we demonstrate that restoring vessel homeostasis without affecting vessel density is feasible in malignant tumors. Combining such vessel re-engineering with anti-cancer drugs allows for strategic treatment approaches that reduce treatment toxicity on non-malignant tissues.