Metastasizing Tumor Cells Research Articles

Arginine Methylation of DDX3 by PRMT1 Mediates Mitochondrial Homeostasis to Promote Breast Cancer Metastasis.

Dysregulated mitochondrial dynamics and metabolism play important roles in tumorigenesis. Metastasizing tumor cells predominantly utilize mitochondrial metabolism, and regulators of metabolic reprogramming may provide reliable biomarkers for diagnosing cancer metastasis. Here, we identified a type I arginine methyltransferase-DEAD-box polypeptide 3, X-linked (PRMT1-DDX3) axis that promotes breast cancer metastasis by coordinating mitochondrial biogenesis and mitophagy to ensure mitochondrial quality control. Mechanistically, PRMT1 induces arginine methylation of DDX3, which enhances its protein stability and prevents proteasomal degradation. DDX3 mediates mitochondrial homeostasis by translocating to mitochondria where it facilitates phosphatase and tensin homology-induced kinase 1 translation in response to mitochondrial stress. Inhibition of DDX3 suppresses mitochondrial biogenesis and mitophagy, resulting in diminished cancer stemness and metastatic properties. Overall, this study uncovers a mechanism by which the PRMT1-DDX3 axis regulates mitochondrial homeostasis to support breast cancer metastasis, suggesting strategies for targeting metabolic vulnerabilities to treat metastatic breast cancer. Significance: DDX3 is stabilized by PRMT1-mediated arginine methylation and coordinates mitophagy and mitochondrial biogenesis by upregulating PINK1 to facilitate breast cancer progression.

Multifunctional Nanoprobe Au@Gd-SiO2-HA-Lyp-1/DOX with Dual-Targeting Functions Derived from HA and LyP-1: Diagnostic and Therapeutic Potential for Tumor Lymphatic Metastasis.

To address lymphatic metastasis in lung cancer, we developed the Au@Gd-SiO2-HA-LyP-1 nanoprobe, assessing its diagnostic and therapeutic capabilities. This nanoprobe integrates a Au core with a Gd-SiO2 shell and dual-targeting HA-LyP-1 molecules. We evaluated its size, shape, and functional properties using various characterization techniques, alongside in vivo and in vitro toxicity tests. The spherical nanoprobes have a 50 nm diameter and contain 1.37% Gd. They specifically target lymphatic metastasis sites and tumor cells, showing enhanced MRI contrast and effective, targeted DOX delivery with reduced normal tissue toxicity. The Au@Gd-SiO2-HA-LyP-1 nanoprobe is a promising tool for diagnosing and treating lung cancer lymphatic metastasis, featuring dual-targeting and superior imaging capabilities.

Abstract 1490: Elucidating the effect of glutamine metabolism in breast to bone metastasis

Abstract Bone-metastatic lesions will develop in approximately 65-75% of patients with metastatic breast cancer and are associated with high morbidity and mortality. Despite our limited understanding of how breast-to-bone metastases form, the recent emergence of metabolic adaptation as a critical factor in metastasis is a promising development. Breast cancer cells are particularly reliant on glutamine, a key amino acid that is metabolized by the enzyme glutaminase (GLS) to facilitate many downstream metabolic processes. Bone-tropic breast cancer cell lines significantly enhance their glutamine uptake, suggesting that glutamine metabolism may be a significant factor in bone metastasis. In addition to tumor cells, glutamine metabolism is critical for osteoblasts, important bone-resident cells that contribute to the “vicious cycle” of bone destruction during metastatic outgrowth in the bone niche. In this study, we sought to evaluate the role of glutamine metabolism in breast cancer bone metastasis by examining the effect of GLS function in metastasizing tumor cells and bone-native osteoblasts. Using an intracardiac inoculation model of bone metastasis, we found that breast cancer cells lacking GLS (GLS KO) failed to effectively form bone metastatic tumors. We also observed that GLS KO bone tumors show a reduction in osteolysis using a direct intratibial injection model. Mechanistically, we have found that GLS KO breast cancer cells develop a “senescence-like” phenotype that may limit metastatic outgrowth within the bone. To investigate the importance of glutamine metabolism in the bone niche, we developed a conditional genetic mouse model to delete GLS in osterix-expressing in osteoblast progenitors and mature osteoblasts (GLSOBKO). Remarkably, we observed reduced bone destruction in GLSOBKO mice after intratibial injection of syngeneic breast cancer cells. We also report a reduction in the number of osteoclasts at the bone/tumor interface in these mice, suggesting that loss of osteoblast GLS could temporarily halt the “vicious cycle” of bone metastasis. Together, this work suggests that glutamine metabolism may promote breast-to-bone metastasis via both intrinsic and extrinsic mechanisms. These findings raise the possibility of using pre-existing cancer therapies targeting glutamine metabolism to ameliorate bone metastatic burden in breast cancer. Citation Format: Breelyn A. Karno, Yoonha Hwang, Rachelle Johnson, Jin Chen, Deanna Edwards. Elucidating the effect of glutamine metabolism in breast to bone metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1490.

Abstract 6267: Evaluating estrogen receptor signaling modifications at bone marrow related stiffnesses in metastatic breast cancer

Abstract Bone metastasis is highly prevalent in breast cancer (BC) patients with metastatic disease and can increase the risk of hypercalcemia and pathological fractures. Several studies have evaluated the mechanisms of metastasized BC cells’ involvement in bone destruction, but how the bone marrow (BM) microenvironment contributes to this process remains ambiguous. Recent studies have shown that as BC cells experience increased stiffnesses outside of the primary microenvironment, there is higher expression of epithelial-to-mesenchymal transition (EMT) markers, increased expression of osteolytic proteins, and decreased drug responses. However, these changes have not been evaluated at stiffnesses relative to the BM. Estrogen receptor (ER) status also plays a pivotal role in BC patient survival. Clinical studies have indicated that the majority of ER+ patients with metastatic disease have more incidences of bone metastases compared to ER- patients. There is some evidence that suggests that the physical properties can also affect estrogen receptor signaling at the primary site, however, there is minimal work to establish how the physical factors of the BM can affect ER sensitivity after metastasis. We hypothesize that higher stiffness ranges of the BM can alter the estrogen receptor sensitivity of metastasized tumor cells and increase osteolysis. To analyze this question, we seeded ER+ BC cell lines (MCF7s and T47Ds) on CytoSoft® Rigidity Plates that mimicked the stiffness of the BM (0.5 - 32 kPa). After 2 days in culture, we probed the expression of downstream estrogen signaling factors, GREB1, PGR, and TIFF1, to evaluate estrogen activity using western blot. Our results show an increase in downstream estrogen signaling at higher stiffnesses (32 kPa) compared to lower stiffnesses (0.5 kPa) at the protein level but not at the transcriptional level. In the future, we will analyze factors associated with osteolysis (ITGB3, TGFB-RII, and PTHLH). Additionally, we plan to conduct RNA sequencing to analyze any larger transcriptional changes at different stiffnesses. Overall, this work gives insight into how estrogen signaling changes in the BM compared to the primary site. It will also give us insight into potential therapeutic targets for ER+ BC after metastasis to the bone. Citation Format: Logan Alexander Northcutt, Marjan Rafat, Julie Rhoades. Evaluating estrogen receptor signaling modifications at bone marrow related stiffnesses in metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6267.

Bone marrow adipocytes and lung cancer bone metastasis: unraveling the role of adipokines in the tumor microenvironment.

Bone is a common site of metastasis for lung cancer. The "seed and soil" hypothesis suggests that the bone marrow microenvironment ("soil") may provide a conducive survival environment for metastasizing tumor cells ("seeds"). The bone marrow microenvironment, comprising a complex array of cells, includes bone marrow adipocytes (BMAs), which constitute about 70% of the adult bone marrow volume and may play a significant role in tumor bone metastasis. BMAs can directly provide energy for tumor cells, promoting their proliferation and migration. Furthermore, BMAs participate in the tumor microenvironment's osteogenesis regulation, osteoclast(OC) regulation, and immune response through the secretion of adipokines, cytokines, and inflammatory factors. However, the precise mechanisms of BMAs in lung cancer bone metastasis remain largely unclear. This review primarily explores the role of BMAs and their secreted adipokines (leptin, adiponectin, Nesfatin-1, Resistin, chemerin, visfatin) in lung cancer bone metastasis, aiming to provide new insights into the mechanisms and clinical treatment of lung cancer bone metastasis.

Platelets induce CD39 expression in tumor cells to facilitate tumor metastasis.

Tumor cells continue to evolve the metastatic potential in response to signals provided by the external microenvironment during metastasis. Platelets closely interact with tumor cells during hematogenous metastasis and facilitate tumor development. However, the molecular mechanisms underlying this process are not fully understood. RNA-sequencing was performed to screen differentially expressed genes mediated by platelets. The effects of platelet and CD39 on tumor metastasis were determined by experimental metastasis models with WT, NCG and CD39-/- mice. RNA-sequencing results showed that platelets significantly up-regulated CD39 expression in tumor cells. CD39 is a novel immune checkpoint molecule and a key driver of immunosuppression. Our data provided evidence that the expression of CD39 was enhanced by platelets in a platelet-tumor cell contact dependent manner. Although the role of CD39 expressed by immune cells is well established, the effect of CD39 expressed by tumor cells on tumor cell behavior, anti-tumor immunity and tumor metastasis is unclear. We found that CD39 promoted tumor cell invasion, but had no effect on proliferation and migration. Notably, we showed that the ability of platelets to prime tumor cells for metastasis depends on CD39 in the experimental tumor metastasis model. CD39 silencing resulted in fewer experimental metastasis formation, and this anti-metastasis effect was significantly reduced in platelet-depleted mice. Furthermore, overexpression of CD39 in tumor cells promoted metastasis. In order to eliminate the effect of CD39 expressed in cells other than tumor cells, we detected tumor metastasis in CD39-/- mice and obtained similar results. Moreover, overexpression of CD39 in tumor cells inhibited antitumor immunity. Finally, the data from human samples also supported our findings. Our study shows that direct contact with platelets induces CD39 expression in tumor cells, leading to immune suppression and promotion of metastasis.

Lung endothelium exploits susceptible tumor cell states to instruct metastatic latency

In metastasis, cancer cells travel around the circulation to colonize distant sites. Due to the rarity of these events, the immediate fates of metastasizing tumor cells (mTCs) are poorly understood while the role of the endothelium as a dissemination interface remains elusive. Using a newly developed combinatorial mTC enrichment approach, we provide a transcriptional blueprint of the early colonization process. Following their arrest at the metastatic site, mTCs were found to either proliferate intravascularly or extravasate, thereby establishing metastatic latency. Endothelial-derived angiocrine Wnt factors drive this bifurcation, instructing mTCs to follow the extravasation–latency route. Surprisingly, mTC responsiveness towards niche-derived Wnt was established at the epigenetic level, which predetermined tumor cell behavior. Whereas hypomethylation enabled high Wnt activity leading to metastatic latency, methylated mTCs exhibited low activity and proliferated intravascularly. Collectively the data identify the predetermined methylation status of disseminated tumor cells as a key regulator of mTC behavior in the metastatic niche.

Regional anesthesia for pain control in children with solid tumors-a review of case reports.

Around seventy percent of all childhood cancer patients suffer from severe pain. This pain can arise from various sources, including tumors themselves, pain caused by metastasizing tumor cells or as the outcome of therapy meant to deal with tumors. If managed inadequately, such pain can lead to many hazardous sequelae. However, there are extreme cases when pain does not respond to standard treatment. For such cases, regional anesthesia or nerve blocks are utilized as the utmost pain control measure. Blocks are used to treat pain in patients who no longer respond to conventional opioid-based treatment or whose worsened condition makes it impossible to receive any other therapy. The data regarding the use of regional anesthesia for such cases in the children population is limited. For this review we searched for case reports in Scopus and PubMed from inception to 2023. The descriptive search items included terms related to childhood cancer and the description of each block. The inclusion criteria for review include children (0-18 years old) receiving oncology-related surgical procedures or palliative care. The data collection was limited to solid tumor-related cases only. We analyzed a total of 38 studies that included case reports and one retrospective study. It was concluded that nerve blocks, although rarely performed, are a safe and efficient way of pain control in children with solid tumors. The major settings for block performance are postoperative pain control and palliative care. We observed that block indication and its outcomes depend on unique health circumstances in which they should be performed. Patients with similar diagnoses had differing outcomes while receiving the same block treatment.

Exploring the Role of Circulating Tumor Cells in Contralateral Neck Metastasis

Background: The management of neck nodes in oral cavity cancers discernibly depends on the approach adopted for the primary tumor. There are abundant literature and consensus guidelines established for ipsilateral neck metastasis in small lateralized oral cavity cancers. However, the literature on the mechanism of contralateral neck metastasis and their management in recurrent settings is sparse. The current analysis aims at elucidating the role of circulating tumor cells (CTCs) in contralateral neck metastasis and the incidence of the same. Materials and Methods: We performed a retrospective cohort study to include all the patients with recurrent ipsilateral oral cavity squamous cell carcinoma who underwent treatment between January 2016 and October 2021. Various parameters were analyzed, and the data were curated to arrive at a conclusion. Results: The analysis of several parameters, including demographics of the patient, tumor site, individual tumor, lymph node, metastasis (TNM) category, depth of invasion (DOI), extra-nodal extension (ENE) status, CTCs, adjuvant treatment received after first surgery followed by TNM category, DOI, worst pattern of invasion, ENE, type of neck dissection, histological grading of tumor, perineural invasion, lymphovascular invasion, nodal yield, and number of nodes positive in the contralateral neck were studied in detail. Conclusion: The study showed a significant correlation between contralateral neck metastasis and CTCs.

The emerging role of breast cancer derived extracellular vesicles-mediated intercellular communication in ovarian cancer progression and metastasis.

Breast cancer is one of the most occurring cancer types in women worldwide and metastasizes to several organs such as bone, lungs, liver, brain, and ovaries. Extracellular vesicles (EVs) mediate intercellular signaling which has a profound effect on tumor development and metastasis. Recent developments in the field of EVs provide an opportunity to investigate the roles of EVs released from tumor cells in metastasis. In this study, we compared the effects of metastatic breast cancer-derived EVs on both nonluteinized granulosa HGrC1 and ovarian cancer OVCAR-3 cells in terms of proliferation, invasion, apoptosis, and gene expression levels. EVs were isolated from the culture medium of metastatic breast cancer cell line MDA-MB-231 by ultracentrifugation. Cell proliferation, apoptosis, cell cycle, invasion, and cellular uptake analysis were performed to clarify the roles of tumor-derived EVs in both cells. 6.85 × 108 nanoparticles of BCD-EVs were markedly increased cell proliferation as well as invasion capacity. Exposing the cells with BCD-EVs for 24h, resulted in an accumulation of both cells in G2/M phase as determined by flow cytometry. The apoptosis assay results were consistent with cell proliferation and cell cycle results. The uptake of the BCD-EVs was efficiently internalized by both cells. In addition, marked variations in fatty acid composition between cells were observed. BCD-EVs appeared new fatty acids in HGrC1. Besides, BCD-EVs upregulated epithelial-mesenchymal transition (EMT) and proliferation-related genes. In conclusion, an environment of tumor-derived EVs changes the cellular phenotype of cancer and noncancerous cells and may lead to tumor progression and metastasis.

Peri Cruiser CAR-T: An innovative platform to reduce on-target off-tumor toxicity of CAR-T therapy.

2539 Background: On-target off-tumor toxicity is a significant concern in Chimeric Antigen Receptor (CAR)-T therapies, especially for solid tumors, leading to adverse effects on normal tissues and impacting on treatment efficacy. To address this challenge, a modified form of CAR-T cells named Peri Cruiser CAR-T has been developed by using miRNA technology to knock down three adhesion genes that mediate T cell transendothelial migration to normal tissues, aiming to block the extravasation of CAR-T cells so that the on-target off-tumor toxicity could be prevented without compromising anti-tumor efficacy. In this study, we provided a proof of concept by using the epithelial cell adhesion molecule (EpCAM) as a targeting tumor-associated antigen (TAA). Methods: An miRNA cassette was incorporated into the vectors of anti-human or mouse EpCAM CARs. The knockdown efficiency, endothelial adhesion efficiency, effector functions and memory phenotypes in vitro were evaluated. To determine the toxicity in vivo, the anti-mouse EpCAM CAR-T cells were administered to non-tumor bearing NSG mice, and the body weight and T cell infiltration in normal tissues was evaluated. Anti-tumor efficacy was also evaluated in NSG mice with subcutaneous and metastatic tumor models by anti-human EpCAM CAR-T cells. Results: Our Peri Cruiser CAR-T platform was capable to effectively downregulate the target genes by 10 folds. The knockdown is stable after extended culture and antigen engagement in vitro. This knockdown of targeted genes significantly decreased T cell adhesion to endothelial cells and corresponding ligands, but did not affect T cell activation or effector functions such as cytotoxicity and IFN gamma release. Surprisingly, lowering the levels of these adhesion molecules improved the memory phenotypes of CAR-T cells as indicated by increased portion of CCR7+CD45RO+ cells. In vivo studies showed that conventional EpCAM CAR-T-injected mice experienced severe weight loss and all had to be sacrificed before day 8, the IHC staining of CD3 revealing massive infiltration of T cells in lung, liver, and kidney. However, the incorporation of the miRNA cassette prevented T cell infiltration in normal tissues, reversed the toxicity, and ensured the survival of all mice. The anti-tumor efficacy of these T cells was evaluated in vivo and found to decrease metastasis as effectively as the conventional CAR-T cells in a metastasis model of HCT116-Luc, although there was a slightly but not significantly decreased efficacy in a subcutaneous model of HCT116. Conclusions: The Peri Cruiser CAR-T platform can significantly improve the safety of CAR-T cells without compromising their efficacy to eliminate tumor cells in primary site and metastasis. This technology opens another avenue to safely target a variety of other TAA by CAR-T even when there is the potential of on-target off-tumor toxicity in normal tissues for those antigens.

Clonogenicity-based radioresistance determines the expression of immune suppressive immune checkpoint molecules after hypofractionated irradiation of MDA-MB-231 triple-negative breast cancer cells.

Only a subset of patients with triple-negative breast cancer (TNBC) benefits from a combination of radio- (RT) and immunotherapy. Therefore, we aimed to examine the impact of radioresistance and brain metastasizing potential on the immunological phenotype of TNBC cells following hypofractionated RT by analyzing cell death, immune checkpoint molecule (ICM) expression and activation of human monocyte-derived dendritic cells (DCs). MDA-MB-231 triple-negative breast cancer tumor cells were used as model system. Apoptosis was the dominant cell death form of brain metastasizing tumor cells, while Hsp70 release was generally significantly increased following RT and went along with necrosis induction. The ICMs PD-L1, PD-L2, HVEM, ICOS-L, CD137-L and OX40-L were found on the tumor cell surfaces and were significantly upregulated by RT with 5 x 5.2 Gy. Strikingly, the expression of immune suppressive ICMs was significantly higher on radioresistant clones compared to their respective non-radioresistant ones. Although hypofractionated RT led to significant cell death induction and release of Hsp70 in all tumor cell lines, human monocyte-derived DCs were not activated after co-incubation with RT-treated tumor cells. We conclude that radioresistance is a potent driver of immune suppressive ICM expression on the surface of TNBC MDA-MB-231 cells. This mechanism is generally known to predominantly influence the effector phase, rather than the priming phase, of anti-tumor immune responses.

Abstract 1242: Single cell multiomic map reveals regulatory landscape of human brain metastases

Abstract Capturing comprehensive brain metastasis landscape is critical to the establishment of effective anti-tumor strategies. This study took advantage of single-cell multiomics sequencing to profile the molecular and cellular dynamics in tumor cells and associated microenvironment during brain metastasis. Among different primary cancer types, our data suggest that there are conserved yet distinct tumor cell subpopulations, governed by specific changes in gene expression, chromatin accessibility and tumor-stroma interactions. We characterized the conserved tumor subpopulations of brain metastasis with features of: (1) dormancy, (2) enhanced translation and migration, (3) cell death and (4) high proliferation rate. Dormant tumor cells in brain metastasis appear to limit cell-cell interactions with the surrounding microenvironment. In line with previous observations, dormant cells exhibit distinct stimulation for interferon, oxidative phosphorylation and HIPPO signaling. Despite a pronounced cell plasticity, trajectory analysis uncovered a cell progression pattern and its major sequential states and driving genes. Importantly, the tumor trajectory provides new insights into the regulatory landscape controlling the transition from dormant to proliferating tumor cells. Our findings also point to a valuable use of matched isolated circulating tumor cells and cell-free DNA to map the molecular and cellular dynamics of brain metastases. This work demonstrated that despite a pronounced intratumoral heterogeneity, brain metastases present conserved tumor subpopulations regardless of the patient and primary type. A novel and key finding in this study is the multiomics characterization of the regulatory landscape shaping human brain metatastases. Thus, we believe further understanding of these key regulatory elements could lead to novel tumor targets with broad translational potential. Citation Format: Remi Klotz, Alexis Zukowski, Mohamed Kamal, Frank Attenelo, Srinivas Ramachandran, Min Yu. Single cell multiomic map reveals regulatory landscape of human brain metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1242.

Abstract 5788: Single-cell and spatial transcriptomic mapping of human renal cell carcinoma brain metastases uncovers actionable immune-resistance targets

Abstract Introduction: The discovery of immune checkpoint inhibitors has revolutionized metastatic renal cell carcinoma (RCC) treatment. However, in patients with RCC brain metastases, response rates are low and survival outcomes poor. To understand the tumor microenvironmental differences between primary kidney tumors, extracranial metastases, and brain metastases, we developed a detailed single-cell atlas of RCC brain metastases along with their matched extracranial and primary tumors. Methods: We performed single-nucleus RNA-seq on 27 samples (nearly 200,000 cells) from RCC patients; samples included 14 brain metastases, 8 matched primary kidney tumors, and 5 matched extracranial metastases. We performed multiplex IHC to validate selected transcriptomic findings. We used Nanostring CosMx 960-plex RNA spatial molecular imaging technique on selected samples to validate cellular interactions in a spatial context. Results: We established a multi-tissue single-cell atlas of RCC brain metastases by identifying 9 major and 37 minor malignant, immune, and stromal cell clusters. Brain metastases had higher neuronal and glial cells interacting with immune and tumor cells. Brain metastasis tumor cells were also transcriptomically reprogrammed to adapt to the brain microenvironment through enrichment of MYC targets, MTORC1 signaling, epithelial-mesenchymal transition, fatty-acid metabolism, oxidative phosphorylation, and reactive oxygen species pathways. Moreover, cell-to-cell communication and downstream target gene expression analyses showed that brain metastasis tumor cells expressed ligands and receptors that induce tumor cell proliferation in both autocrine and paracrine fashions. Among T-cell populations, we found fewer proliferating cytotoxic T lymphocytes in the brain than in other sites. Moreover, T cells in brain metastases expressed higher levels of several targetable inhibitory checkpoints than did extracranial metastases. In addition, we found that naïve/memory T cells in brain metastases were a favorable prognostic marker for overall survival after craniotomy. Our characterization of myeloid cell populations across the 3 disease sites found fewer dendritic cells and monocytes in the brain compared to other sites. Macrophages in brain metastases more highly expressed an M2 immunosuppressive gene signature than did those in primary RCC tumors. Conclusion: Our findings from the largest single-cell atlas of RCC brain metastases with matched primary and extracranial metastases suggest several unique targetable, immunosuppressive biological mechanisms in the brain microenvironment. These results provide a foundation for a deeper understanding of RCC brain metastasis biology and can serve as a resource for the scientific community to further explore therapeutically targetable tumor and immune-related mechanisms. Citation Format: Elshad Hasanov, Truong Nguyen Anh Lam, Jerome Lin, Patrick K. Reville, Merve Hasanov, Anna K. Casasent, David Shih, Sahin Hanalioglu, Mehmet Asim Bilen, Omar Alhalabi, Berrin Babaoglu, Baylar Baylarov, Adeboye O. Osunkoya, Lisa M. Norberg, Joy Gumin, Tuan M. Tran, Jianzhuo Li, Anh G. Hoang, Haidee D. Chancoco, Brittany C. Parker Kerrigan, Erika J. Thompson, Betty YS Kim, Dima Suki, Melike Mut, Figen Soylemezoglu, Giannicola Genovese, Kadir C. Akdemir, Hussain A. Tawbi, Nizar M. Tannir, Florencia McAllister, Michael A. Davies, Padmanee Sharma, Jason Huse, Frederick Lang, Nicholas Navin, Eric Jonasch. Single-cell and spatial transcriptomic mapping of human renal cell carcinoma brain metastases uncovers actionable immune-resistance targets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5788.

Adaptive activation of EFNB2/EPHB4 axis promotes post-metastatic growth of colorectal cancer liver metastases by LDLR-mediated cholesterol uptake

The microenvironment of distant organ plays vital roles in regulating tumor metastases. However, little is known about the crosstalk between metastasized tumor cells and target organs. Herein, we found that EFNB2 expression was upregulated in liver metastases (LM) of colorectal cancer (CRC), but not in pulmonary metastases (PM) or primary CRC tumors. EFNB2 played a tumor-promoting role in CRC LM in vitro and in vivo. Through forward signaling, EFNB2-promoted CRC LM by interacting with the EPHB4 receptor. EFNB2/EPHB4 axis enhances LDLR-mediated cholesterol uptake in CRC LM. Subsequently, EFNB2/EPHB4 axis promotes LDLR transcription by regulating STAT3 phosphorylation. Blocking LDLR reversed the role of the EFNB2/EPHB4 axis in promoting CRC LM. Using clinical data, survival analysis revealed that the survival time of patients with CRC LM was decreased in patients with high EFNB2 expression, compared with low EFNB2 expression. Inhibition of the EFNB2/EPHB4 axis markedly prolonged the survival time of BALB/c nude mice with CRC LM with a high cholesterol diet. These findings revealed a key step in the regulation of cholesterol uptake by EFNB2/EPHB4 axis and its tumor-promoting role in CRC LM.

From bioinformatic screening of genetic markers to low invasive lymph node metastases diagnosis in patients with cervical cancer

Background. The problem of lymph nodes metastases diagnosing in cervical cancer remains relevant and not fully resolved. The last decade studies results have shown the great potential of molecular markers in lymph nodes metastasis prediction, however, additional studies for their implementation in clinical practice are required.
 Aim. Bioinformatic and laboratory screening of molecular markers of cervical tumors regional metastasis for its low invasive diagnosis.
 Material and methods. The study was performed on 400 patients with cervical cancer and 40 donors without oncological pathology. To identify potential molecular markers of lymph node metastatic lesions, the Cancer Genome Atlas database was initially analyzed. The identified markers were validated by the Real-Time-polymerase chain reaction in tumor cell samples (extracted using laser microdissection) and extracellular deoxyribonucleic acid (DNA). The MannWhitney test was used to assess the differences; the Bonferroni correction was used to account for multiple comparisons.
 Results. At the bioinformation stage, the change in the copy number of 5493 genes was analyzed, of which 79 genes were selected that most often change their copy number. During the data validation, it was found that primary tumor cells and tumor cells of metastases from the lymph nodes differ from normal cervix cells in the level of gene copies. The copy number of the CCND1 and PPARGC1A genes has the highest potential for regional lymph nodes metastases diagnosing in patients with cervical cancer; the PIK3CA, SPEN, ERBB3, APC, MUC4, CASP8, HLA-A, IGSF1 and TMTC1 loci have a lower potential. The EP300, TTN, DMD, DST, LAMP3, TORC2, TP53 and FOXO3 genes can be used to diagnose cervical cancer, whether metastatic or not. Additional validation of markers was carried out on extracellular DNA of blood plasma of cervical cancer patients and conditionally healthy donors. The presence of a differential copy number of PIK3CA, SPEN, ERBB3, APC, CCND1, HLA-A, TTN, MUC4, DST, PPARGC1A genes was found in two groups of patients with cervical cancer with and without metastatic lesions of the lymph nodes.
 Conclusion. The study made it possible to form a list of potential molecular markers for low invasive diagnostics of cervical cancer in general (EP300, LAMP3, TORC2, FOXO3, TP53) and cervical cancer with metastatic lesions of regional lymph nodes (PIK3CA/DST, APC/PPARGC1A, ERBB3/HLA-A and LAMP3/MUC4).

Peptide-Functionalized Nanoparticles for the Targeted Delivery of Cytotoxins to MMP-14-Expressing Cancer Cells

As 90% of cancer-patient deaths are due to metastasis, novel therapeutics that selectively target and kill metastatic cells are desperately needed. Matrix metalloproteinase-14 (MMP-14), which plays a critical role in digesting the basement membrane and in inducing cancer cell migration, has been found to be expressed at the cell surface of circulating and metastasized tumor cells in various human cancers. We have recently shown that the IVS4 peptide, which mimics the minimal binding motif of the hemopexin-like (PEX) domain of MMP-14, interrupts MMP-14 dimerization and decreases MMP-14-mediated cell invasion. In this study, cancer-homing nanocarriers were assembled by linking IVS4 to polysaccharide-based nanoparticles (NPs), followed by the encapsulation of a pharmaceutical agent. IVS4-NPs efficiently prevented MMP-14-mediated cell migration and conferred an uptake advantage compared to the control peptide in an MMP-14-dependent manner. While the IVS4-NPs alone were not cytotoxic, drug-encapsulated NPs were shown to effectively target MMP-14-expressing cancer cells. This novel nanotherapeutic is capable of inhibiting MMP-14-mediated functions and efficiently killing MMP-14-expressing cancer cells, without affecting the viability of non-cancer cells.

The role of RHAMM in cancer: Exposing novel therapeutic vulnerabilities.

Receptor for hyaluronic acid-mediated motility (RHAMM) is a cell surface receptor for hyaluronic acid that is critical for cell migration and a cell cycle protein involved in microtubule assembly and stability. These functions of RHAMM are required for cellular stress responses and cell cycle progression but are also exploited by tumor cells for malignant progression and metastasis. RHAMM is often overexpressed in tumors and is an independent adverse prognostic factor for a number of cancers such as breast and prostate. Interestingly, pharmacological or genetic inhibition of RHAMM in vitro and in vivo ablates tumor invasiveness and metastatic spread, implicating RHAMM as a potential therapeutic target to restrict tumor growth and improve patient survival. However, RHAMM’s pro-tumor activity is dependent on its subcellular distribution, which complicates the design of RHAMM-directed therapies. An alternative approach is to identify downstream signaling pathways that mediate RHAMM-promoted tumor aggressiveness. Herein, we discuss the pro-tumoral roles of RHAMM and elucidate the corresponding regulators and signaling pathways mediating RHAMM downstream events, with a specific focus on strategies to target the RHAMM signaling network in cancer cells.

Ectopic ACTH-producing neuroendocrine tumor occurring with large recurrent metastatic pheochromocytoma: a case report

BackgroundEctopic ACTH-dependent Cushing syndrome is rarely caused by pheochromocytoma (PCC). Glucocorticoid-regulated positive feedback loops in ACTH and catecholamines were proposed in some similar cases.Case presentationWe present here an 80-year-old man who had previously undergone surgery for a left adrenal PCC and newly developed severe hypertension, hypokalemia, and typical Cushingoid manifestations. Investigations revealed hyperglycemia, hypokalemia, and extremely high catecholamines and their metabolites, ACTH and cortisol. Imaging modalities showed a recurrent large left adrenal mass positively visualized with 123I-metaiodobenzylguanidine as well as somatostatin receptor scintigraphy. Surgical interventions were not indicated; thus, metyrapone, phentolamine, and doxazocin were initiated, which successfully controlled his symptoms and biochemical conditions. With the evidence that metyrapone administration decreased ACTH and catecholamine levels, the existence of positive feedback loops was speculated. During the terminal stages of the disease, additional metyrosine treatment successfully stabilized his physiological and biochemical conditions. Upon the patient’s death, pathological autopsy was performed. Immunohistochemical analysis indicated that the tumor appeared to be co-positive with tyrosine hydroxylase (TH) as well as ACTH in most tumor cells in both PCC and liver metastasis. Most cells were clearly positive for somatostatin receptor 2 staining in the membrane compartment. The dense immunostaining of ACTH, TH, dopamine-β-hydroxylase and the large tumor size with positive feedback loops may be correlated with high levels of ACTH and catecholamines in the circulation.ConclusionsWe experienced a case of severe ectopic ACTH producing the largest reported recurrent malignant left PCC with liver metastases that presented positive feedback loops in the ACTH/cortisol and catecholamine/cortisol axes. Clinicians should be aware of the paradoxical response of ACTH on metyrapone treatment and possible steroid-induced catecholamine crisis.

Acute T-Cell-Driven Inflammation Requires the Endoglycosidase Heparanase-1 from Multiple Cell Types.

It has been accepted for decades that T lymphocytes and metastasising tumour cells traverse basement membranes (BM) by deploying a battery of degradative enzymes, particularly proteases. However, since many redundant proteases can solubilise BM it has been difficult to prove that proteases aid cell migration, particularly in vivo. Recent studies also suggest that other mechanisms allow BM passage of cells. To resolve this issue we exploited heparanase-1 (HPSE-1), the only endoglycosidase in mammals that digests heparan sulfate (HS), a major constituent of BM. Initially we examined the effect of HPSE-1 deficiency on a well-characterised adoptive transfer model of T-cell-mediated inflammation. We found that total elimination of HPSE-1 from this system resulted in a drastic reduction in tissue injury and loss of target HS. Subsequent studies showed that the source of HPSE-1 in the transferred T cells was predominantly activated CD4+ T cells. Based on bone marrow chimeras, two cellular sources of HPSE-1 were identified in T cell recipients, one being haematopoiesis dependent and the other radiation resistant. Collectively our findings unequivocally demonstrate that an acute T-cell-initiated inflammatory response is HPSE-1 dependent and is reliant on HPSE-1 from at least three different cell types.