Metastatic Growth Research Articles

Loss of Pip4k2c confers liver-metastatic organotropism through insulin-dependent PI3K-AKT pathway activation.

Liver metastasis (LM) confers poor survival and therapy resistance across cancer types, but the mechanisms of liver-metastatic organotropism remain unknown. Here, through in vivo CRISPR-Cas9 screens, we found that Pip4k2c loss conferred LM but had no impact on lung metastasis or primary tumor growth. Pip4k2c-deficient cells were hypersensitized to insulin-mediated PI3K/AKT signaling and exploited the insulin-rich liver milieu for organ-specific metastasis. We observed concordant changes in PIP4K2C expression and distinct metabolic changes in 3,511 patient melanomas, including primary tumors, LMs and lung metastases. We found that systemic PI3K inhibition exacerbated LM burden in mice injected with Pip4k2c-deficient cancer cells through host-mediated increase in hepatic insulin levels; however, this circuit could be broken by concurrent administration of an SGLT2 inhibitor or feeding of a ketogenic diet. Thus, this work demonstrates a rare example of metastatic organotropism through co-optation of physiological metabolic cues and proposes therapeutic avenues to counteract these mechanisms.

Single‑agent nintedanib suppresses metastatic osteosarcoma growth by inhibiting tumor vascular formation.

New therapeutic approaches are needed for osteosarcoma, which is the most common malignancy of the bone, especially for metastatic cases. Nintedanib is a potent, oral tyrosine kinase inhibitor approved for treating idiopathic pulmonary fibrosis, which blocks a variety of receptor signals, including fibroblast growth factor receptors, vascular endothelial growth factor receptors and platelet-derived growth factor receptors. The present study assessed the effect of nintedanib on previously developed mouse AXT osteosarcoma cells, and on AXT-derived osteosarcoma developed in C57BL/6 mice, which displays lethal tumors with osteoid formation and lung metastatic lesions that mimics human disease. In vitro analysis, including flow cytometry and immunoblotting, revealed that nintedanib inhibited AXT cell proliferation and cell cycle progression, induced apoptosis, and inactivated AKT and ERK1/2. Immunoblot analysis using tumor lysates demonstrated that nintedanib inhibited its target molecules in vivo. As a single agent, nintedanib decreased the size of primary AXT-derived osteosarcoma, and reduced circulating tumor cells and lung metastasis. Immunohistochemical findings indicated that nintedanib exerted antitumor activity mainly by inhibiting the formation of CD31-positive tumor vasculature, while αSMA-positive cells were still enriched in tumors after nintedanib treatment. In addition, nintedanib exhibited an anti-osteosarcoma effect on C57BL/6 severe combined immunodeficient mice in which T- and B-cell function is obsolete, suggesting that the antitumor effect of nintedanib was not attributable to antitumor immunity. Collectively, these findings indicated that nintedanib holds potential for treating osteosarcoma.

Suppression of metastatic organ colonization and antiangiogenic activity of the orally bioavailable lipid raft-targeted alkylphospholipid edelfosine

Metastasis is the leading cause of cancer mortality. Metastatic cancer is notoriously difficult to treat, and it accounts for the majority of cancer-related deaths. The ether lipid edelfosine is the prototype of a family of synthetic antitumor compounds collectively known as alkylphospholipid analogs, and its antitumor activity involves lipid raft reorganization. In this study, we examined the effect of edelfosine on metastatic colonization and angiogenesis. Using non-invasive bioluminescence imaging and histological examination, we found that oral administration of edelfosine in nude mice significantly inhibited the lung and brain colonization of luciferase-expressing 435-Lung-eGFP-CMV/Luc metastatic cells, resulting in prolonged survival. In metastatic 435-Lung and MDA-MB-231 breast cancer cells, we found that edelfosine also inhibited cell adhesion to collagen-I and laminin-I substrates, cell migration in chemotaxis and wound-healing assays, as well as cancer cell invasion. In 435-Lung and other MDA-MB-435-derived sublines with different organotropism, edelfosine induced G2/M cell cycle accumulation and apoptosis in a concentration- and time-dependent manner. Edelfosine also inhibited in vitro angiogenesis in human and mouse endothelial cell tube formation assays. The antimetastatic properties were specific to cancer cells, as edelfosine had no effects on viability in non-cancerous cells. Edelfosine accumulated in membrane rafts and endoplasmic reticulum of cancer cells, and membrane raft-located CD44 was downregulated upon drug treatment. Taken together, this study highlights the potential of edelfosine as an attractive drug to prevent metastatic growth and organ colonization in cancer therapy. The raft-targeted drug edelfosine displays a potent activity against metastatic organ colonization and angiogenesis, two major hallmarks of tumor malignancy.

Target-induced hot spot construction for sensitive and selective surface-enhanced Raman scattering detection of matrix metalloproteinase MMP-9

Studies have found that matrix metalloproteinase-9 (MMP-9) plays a significant role in cancer cell invasion, metastasis, and tumor growth. But it is a challenge to go for highly sensitive and selective detection and targeting of MMP-9 due to the similar structure and function of the MMP proteins family. Herein, a novel surface-enhanced Raman scattering (SERS) sensing strategy was developed based on the aptamer-induced SERS “hot spot” formation for the extremely sensitive and selective determination of MMP-9. To develop the nanosensor, one group of gold nanospheres was modified with MMP-9 aptamer and its complementary strand DNA1, while DNA2 (complementary to DNA1) and the probe molecule 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) were grafted on the surface of the other group of gold nanospheres. In the absence of MMP-9, DTNB located on the 13-nm gold nanospheres has only generated a very weak SERS signal. However, when MMP-9 is present, the aptamer preferentially binds to the MMP-9 to construct MMP-9–aptamer complex. The bare DNA1 can recognize and bind to DNA2, which causes them to move in close proximity and create a SERS hot spot effect. Due to this action, the SERS signal of DTNB located at the nanoparticle gap is greatly enhanced, achieving highly sensitive detection of MMP-9. Since the hot spot effect is caused by the aptamer that specifically recognizes MMP-9, the approach exhibits excellent selectivity for MMP-9 detection. Based on the benefits of both high sensitivity and excellent selectivity, this method was used to distinguish the difference in MMP-9 levels between normal and cancer cells as well as the expression of MMP-9 from cancer cells with different degrees of metastasis. In addition, this strategy can accurately reflect the dynamic changes in intracellular MMP-9 levels, stimulated by the MMP-9 activator and inhibitor. This strategy is expected to be transformed into a new technique for diagnosis of specific cancers related to MMP-9 and assessing the extent of cancer occurrence, development and metastasis.Graphical

ZC3H12A inhibits tumor growth and metastasis of breast cancer under hypoxic condition via the inactivation of IL-17 signaling pathway

ABSTRACT Hypoxia is a major contributor to tumor microenvironment (TME) and metastasis in most solid tumors. We seek to screen hypoxia-related genes affecting metastasis in breast cancer and to reveal relative potential regulatory pathway. Based on gene expression profiling of GSE17188 dataset, differential expressed genes (DEGs) were identified between highly metastatic breast cancer cells under hypoxia and samples under normoxia. The protein–protein interaction (PPI) network was utilized to determine hub genes. The gene expression profiling interactive analysis database (GEPIA2) and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) were employed to quantify hub genes. Moreover, overexpression of zinc finger CCCH-type containing 12A (ZC3H12A) was performed both in breast cancer cells and xenograft mouse model to determine the role of ZC3H12A. We identified 134 DEGs between hypoxic and normoxic samples. Based on PPI analysis, 5 hub genes interleukin (IL)-6, GALN (GAL), CD22 molecule (CD22), ZC3H12A and TNF receptor associated factor 1 (TRAF1) were determined; the expression levels of TRAF1, IL-6, ZC3H12A and GAL were remarkably downregulated while CD22 was upregulated in breast cancer cells. Besides, patients with higher expression of ZC3H12A had favorable prognosis. Overexpression of ZC3H12A could inhibit metastasis and tumor growth of breast cancer; overexpression of ZC3H12A downregulated the expression of IL-17 signaling pathway-related proteins such as IL-17 receptor A (IL-17RA), IL-17A and nuclear factor κB activator 1 (Act1). This study reveals ZC3H12A and IL-17 signaling pathway as potential therapeutic targets for hypoxic breast cancer.

Abstract C106: IMPACT restrains immuno-metabolic GCN1 signaling to govern pancreatic cancer metastasis

Abstract Introduction: Metastatic outgrowth and colonization requires that disseminated tumor cells simultaneously compensate for alterations in nutrient availability, counteract oxidative stress, and evade host innate and adaptive immune surveillance. The mechanistic underpinnings of how these vital processes are coordinated is not understood. Experimental procedures: Using intrasplenic injection (liver metastases) and tail vein injection (lung metastases), we employed a gain-of-function cDNA screen in mice to identify regulators of colonization. In doing so, we identified GCN1 signaling as indispensable to the disseminated pancreatic cancer cell. Summary of unpublished data: Specifically, we demonstrate that alterations in nutrient availability encountered in target organs (liver, lung) trigger pancreatic cancer cells to utilize GCN1 stress signaling to upregulate the expression of serine, folate, and methionine pathway biosynthetic enzymes together with amino acid transporters through the integrated stress response effector ATF4. These pathways act in concert to facilitate acquisition of metabolites critical for cellular functions including maintenance of redox homeostasis. Surprisingly, we found that GCN1 also functions in the nucleus, where it interacts with HNRNPK to destabilize the transcripts encoding natural killer (NK) cell activation ligands and key regulators of major histocompatibility complex (MHC) class I molecules. Intriguingly, we identified an endogenous protein rheostat, IMPACT, for GCN1’s dual functions and show that IMPACT expression is lost in human pancreatic metastases through DNA methylation. IMPACT overexpression in pancreatic cancer cell lines inhibited the integrated stress response effector ATF4 to retard nutrient uptake and activated the expression of NK cell ligands and MHC class I molecules to fuel anti-tumor immune responses. Conversely, IMPACT knockout enabled successful acquisition of metabolic intermediaries in response to nutrient alterations and suppressed anti-tumor immune response to accelerate metastatic outgrowth. Accordingly, bioinformatic analyses of human pancreatic cancer showed that while the expression of GCN1 increases in metastatic disease, the expression of IMPACT is lost, correlating with significantly shorter survival of GCN1-high, IMPACT-low expressing tumors. Finally, IMPACT overexpression synergized with immune checkpoint inhibitors in mice to eliminate macrometastases formation. Conclusion: In summary, we have identified IMPACT as an immunometabolic checkpoint that restrains GCN1-mediated metabolic plasticity and GCN1-mediated suppression of innate and adaptive immune surveillance. We propose that drugs that can restore IMPACT expression or IMPACT mimetic agents will have therapeutic value for patients with pancreatic cancer. Citation Format: Surajit Sinha, Abir Panda, Zeribe Nwosu, Rodrigo Neves Das, Xu Ke, Elke van Beek, Alexander J. Rossi, Reed I. Ayabe, James McDonald, Michael M. Wach, Samantha Ruff, Priyanka P. Desai, David Sun, Martha E. Teke, Emily A. Verbus, Areeba Saif, Shreya Gupta, Tahsin Khan, Leila Sarvestani, Carrie E. Ryan, Jacob Lambdin, Kirsten Remmert, Emily Smith, Kenneth Luberice, Stephie Lux, Imani A. Alexander, Tracey Pu, Allen Luna, Sarfraz R. Akmal, Shahyan Rehman, Ashley Rainey, Hanna Hong, Yuri Lin, Samantha Sevilla, Gasmi Billel, Sivasish Sindiri, Todd Prickett, King Chan, Eileen Li, Xiaolin Wu, Nicholas D. Klemen, Giorgio Trinchieri, Costas A. Lyssiotis, Jeremy Davis, Pankaj K. Singh, Steven A. Rosenberg, Michael B. Yaffe, Filippo Giancotti, Ethan M. Shevach, Jonathan M. Hernandez. IMPACT restrains immuno-metabolic GCN1 signaling to govern pancreatic cancer metastasis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C106.

Abstract B108: Integrated in vivo dissection of metastatic phenotypes and molecular programs in pancreatic ductal adenocarcinoma

Abstract The ability of pancreatic ductal adenocarcinoma (PDAC) cells to form tissue destructive metastases remains a critical impediment to therapy. Metastasis is a complex multistep process that is poorly understood and the molecular events and cellular states that enable cancer cells to overcome each step of the metastatic cascade remain elusive. To investigate the regulators of PDAC metastasis, we accrued and characterized a panel of 31 cell lines generated from mouse models of PDAC. Initial experiments indicated that these cell lines have an ~40-fold difference in their ability to form lung metastases after transplantation into immunocompetent recipient mice. To more accurately quantify the relationship between metastatic seeding, growth, organ tropism, and immune evasion across all cell lines in parallel, we tagged each cell line with a barcode that provides both cell line-level and subclonal-level resolution. We pooled all 31 barcoded cell lines, transplanted them to seed metastases in different organs, and performed barcode sequencing on DNA from the metastasis-bearing tissues after short (seeding) and long (expansion) time periods. Neither seeding nor metastatic outgrowth correlated with growth in culture. Metastatic seeding did not directly correlate with overall metastatic burden, indicating that these processes depend on distinct biological processes. Transplantation into syngeneic immune-competent and immune-deficient recipient mice quantified the impact of immune responses towards each cell line. Bulk and single cell RNA-sequencing uncovered unexpected intra- and inter-cell line heterogeneity. Future experiments will integrate the data on metastatic phenotypes with molecular information to uncover drivers and inhibitors of each step of the metastatic cascade. Broad-scale molecular profiling coupled with quantitative in vivo analysis of metastatic phenotypes will uncover the relationships between metastatic phenotypes, create a resource for the community, and reveal novel pathways that govern PDAC metastasis, which could have implications for developing novel therapeutic strategies. Citation Format: Saswati Karmakar, Anastasia Lyulina, Xiaochen Xiong, Yuning J. Tang, Steven Lopez, Nicolas William Hughes, Laura Attardi, Dmitri A. Petrov, Monte M. Winslow. Integrated in vivo dissection of metastatic phenotypes and molecular programs in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B108.

Abstract A018: Exercise stimulates anti-tumoral immunity in metastatic PDAC

Abstract The majority of pancreatic ductal adenocarcinoma (PDAC) patients are metastatic at presentation with limited treatment options and a poor overall 5-year survival of 3%. The liver is the predominant site of distant metastasis in PDAC. Our group has previously shown that aerobic exercise can inhibit tumorigenesis in a primary PDAC mouse model by promoting anti-tumor immunity, however, the effects of exercise in the metastatic setting have not been explored. As such, we developed a model of PDAC liver metastasis by isolating primary pancreatic and liver metastatic cell lines from 18–20-week-old LSL-KRasG12D/+; LSL-Trp53R172H/+; p48Cre; Rosa26LSL-tdTomato/+ (KPCTpancreas or KPCTliver, respectively) mice. KPCTpancreas cells were surgically implanted into the pancreata of syngeneic wild-type mice. One week after pancreatic implantation, KPCTliver cells were implanted into the liver either by direct injection into the parenchyma or via the portal vein. The portal vein method enables us to account for the extravasation step of the metastatic cascade, while the direct parenchymal injection offers a less invasive surgery. Both models preserve the spleen, which is the largest secondary lymphoid organ and essential to the immune response. Treadmill running was initiated in the aerobic exercise cohort 5 days per week for 2 weeks or mice were allowed to rest. Endpoint analysis revealed that aerobic exercise treatment decreased tumor burden in both primary tumors and liver metastasis as measured by tumor weights and tdTomato fluorescence imaging when compared to the rested controls. Immune profiling of the liver metastases revealed elevated IL-15Rɑ+ CD8+ T cells as well as CD19+ B cells in the exercise cohort. While identification of IL-15Rɑ+ CD8+ T cells is consistent with the immune changes we have previously reported in the primary pancreatic tumor of exercised mice, the latter changes reveal organ specific immune cell recruitment not observed in the primary pancreatic tumor of exercised mice. The combined immune profiling and phenotypic changes suggest that aerobic exercise reduces PDAC metastatic growth by modulating systemic and intra-tumoral immunity. The induction of an anti-tumorigenic immune response by aerobic exercise could open avenues for potential pharmacological intervention in downstream pathways to aid in the treatment of metastatic PDAC. Citation Format: Mansour E. Riachi, Carolina G. Alcantara Hirsch, Erica Ma, Beny Shapiro, Ammar Javed, Christopher L. Wolfgang, Dafna Bar-Sagi. Exercise stimulates anti-tumoral immunity in metastatic PDAC [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A018.

Genetically modified ZIKA virus as a microRNA-sensitive oncolytic virus against central nervous system tumors

Here we introduce a first-in-class microRNA-sensitive oncolytic Zika virus (ZIKV) for virotherapy application against central nervous system (CNS) tumors. The described methodology produced two synthetic modified ZIKV strains that are safe in normal cells, including neural stem cells, while preserving brain tropism and oncolytic effects in tumor cells. The microRNA-sensitive ZIKV introduces genetic modifications in two different virus sites: firstly, in the established 3’UTR region, and secondly, in the ZIKV protein coding sequence, demonstrating for the first time that the miRNA inhibition systems can be functional outside the UTR RNA sites. The total tumor remission in mice bearing human CNS tumors, including metastatic tumor growth, after intraventricular and systemic modified ZIKV administration, confirms the promise of this virotherapy as a novel agent against brain tumors - highly deadly diseases in urgent need of effective advanced therapies.

Abscisic acid signaling through LANCL2 and PPARγinduces activation of p38MAPK resulting indormancy of prostate cancer metastatic cells.

Prostate cancer (PCa) is one the most common malignancies in men. The high incidence of bone metastasis years after primary therapy suggests that disseminated tumor cells must become dormant, but maintain their ability to proliferate in the bone marrow. Abscisic acid (ABA) is a stress response molecule best known for its regulation of seed germination, stomal opening, root shoot growth and other stress responses in plants. ABA is also synthesized by mammalian cells and has been linked to human disease. The aim of the present study was to examine the role of ABA in regulating tumor dormancy via signaling through lanthionine synthetase C‑like protein 2 (LANCL2) and peroxisome proliferator activated receptor γ (PPARγ) receptors. ABA signaling in human PCa cell lines was studied using targeted gene knockdown (KD), western blotting, quantitative PCR, cell proliferation, migration, invasion and soft agar assays, as well as co‑culture assays with bone marrow stromal cells. The data demonstrated that ABA signaling increased the expression of p21, p27 and p16, while inhibiting viability, migration, invasion and colony size in a reversable manner without toxicity. ABA also induced p38MAPK activation and NR2F1 signaling. Targeted gene KD of LANCL2 and PPARγ abrogated the cellular responses to ABA. Taken together, these data demonstrate that ABA may induce dormancy in PCa cell lines through LANCL2 and PPARγ signaling, and suggest novel targets to manage metastatic PCa growth.

Nano formulated Resveratrol inhibits PD-L1 in oral cancer cells by deregulating the association between tumor associated macrophages and cancer associated fibroblasts through IL-6/JAK2/STAT3 signaling axis

Tumor associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) in the tumor microenvironment secrete several cytokines, which involved in tumor initiation, progression, metastatic outgrowth and angiogenesis. However, the association between TAMs and CAFs in the context of tumor development remain unclear. Here, we studied the relationship between TAMs and CAFs along with the involvement of cytokines in the production of cancer-stem-like-cells (CSCs) in oral cancer cells and explored the potential anticancer effects of Nano-formulated Resveratrol (Res-NP) using an activated macrophage-M1 (AM-M1) and activated fibroblast cells as the model system. IL-6 secretion was found to be enhanced in the conditioned-medium (CM) when AM-M1 cells + CAFs-like cells were cocultured together. CSCs-enriched population was developed after addition of CM of AM-M1 +CAFs in H-357 cells and patient-derived-primary-oral-cancer cells. AM-M1 cells+ CAFs-like cells secreted IL-6 enhanced CSCs growth, proliferation, metastasis, and angiogenesis. IL-6 was found to promote PD-L1 expression in CSCs-enriched cells via JAK2/STAT3 pathway, as evident from the enhanced expression of p-JAK2 and p-STAT3. Nevertheless, Res-NP inhibited CSCs proliferation and reduced the expression of metastatic and angiogenic markers, in ovo blood vascularization, NO production and MMPs expression. Res-NP delinked the association between AM-M1 and CAFs by blocking IL-6 production and also disrupted the potential connection between IL-6 and PD-L1 with considerable decrease in p-JAK2 and p-STAT3 expressions. IL-6 depletion inhibited stemness and angiogenesis in oral CSCs by downregulating PD-L1 via JAK2/STAT3 cascade. Similar observations were also observed in Res-NP treated xenograft mice. Thus, data demonstrate that CSCs growth is dependent on IL-6/PD-L1 axis. Res-NP deregulates the association between AM-M1 and CAFs along-with attenuates carcinogenesis in in vitro, in ovo, ex vivo and in vivo model systems by inhibiting PD-L1 via IL-6/JAK2/STAT3 axis.

Discovery of Novel Pyrimidine Based Small Molecule Inhibitors as VEGFR-2 Inhibitors: Design, Synthesis, and Anti-Cancer Studies.

Receptor tyrosine kinases (RTKs) are potent oncoproteins in cancer that, when mutated or overexpressed, can cause uncontrolled growth of cells, angiogenesis, and metastasis, making them significant targets for cancer treatment. Vascular endothelial growth factor receptor 2 (VEGFR2), is a tyrosine kinase receptor that is produced in endothelial cells and is the most crucial regulator of angiogenic factors involved in tumor angiogenesis. So, a series of new substituted N-(4-((2-aminopyrimidin-5-yl)oxy)phenyl)-N-phenyl cyclopropane1,1-dicarboxamide derivatives as VEGFR-2 inhibitors have been designed and synthesized. Utilizing H-NMR, C13-NMR, and mass spectroscopy, the proposed derivatives were produced and assessed. HT-29 and COLO-205 cell lines were used for the cytotoxicity tests. The effective compound was investigated further for the Vegfr-2 kinase inhibition assay, cell cycle arrest, and apoptosis. A molecular docking examination was also carried out with the Maestro-12.5v of Schrodinger. In comparison to the reference drug Cabozantinib (IC50 = 9.10 and 10.66 µM), compound SP2 revealed promising cytotoxic activity (IC50 = 4.07 and 4.98 µM) against HT-29 and COLO-205, respectively. The synthesized compound SP2 showed VEGFR-2 kinase inhibition activity with (IC50 = 6.82 µM) against the reference drug, Cabozantinib (IC50 = 0.045 µM). Moreover, compound SP2 strongly induced apoptosis by arresting the cell cycle in the G1 phase. The new compounds' potent VEGFR-2 inhibitory effect was noted with key amino acids Asp1044, and Glu883, and the hydrophobic interaction was also observed in the pocket of the VEGFR-2 active site by using a docking study. The results demonstrate that at the cellular and enzyme levels, the synthetic compounds SP2 are similarly effective as cabozantinib. The cell cycle and apoptosis data demonstrate the effectiveness of the suggested compounds. Based on the findings of docking studies, cytotoxic effects, in vitro VEGFR-2 inhibition, apoptosis, and cell cycle arrest, this research has given us identical or more effective VEGFR-2 inhibitors.

Combination of radiotherapy and Anlotinib enhances benefit from immunotherapy to liver metastasis and abscopal tumor from lung cancer

Many studies have shown that liver metastasis can weaken the efficacy of immunotherapy. Immunotherapy combined with radiotherapy or anti-angiogenic therapy has been proven to have synergistic anti-tumor effects. So we devote to explore whether the combination of the three therapies can exert effective anti-tumor effects on liver metastasis. The clinical information of 118 patients with liver metastasis were collected to compare the intrahepatic progression-free survival between immunotherapy and immunotherapy combined with other treatments. We used Lewis lung cancer (LLC) cell to establish a mouse liver metastasis tumor model and record tumor burden and survival. Tumor-infiltrating immune cells detected by flow cytometry. RNA sequencing was performed and the proportion of immune cells were analyzed by TIMER2.0 database. Compared with immunotherapy group, the combination therapy group showed a trend for longer median intrahepatic progression-free survival. Radiotherapy combined with PD-1 inhibitor and Anlotinib can inhibit liver metastasis and subcutaneous tumor growth and prolong the survival compared with other groups in vivo. Compared with the anti-PD-1 treatment group, triple therapy can increase CD4+T, CD8+T, and IFN-γ+CD8+T cells and decrease infiltration of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) in tumors. PPAR signaling pathway were significantly activated and CD8+T and dendritic cells (DC) were increased in the triple therapy group compared to the PD-1 inhibitor combined with Anlotinib group. Radiotherapy combined with PD-1 inhibitor and Anlotinib can effectively exert anti-tumor efficacy and reshape the tumor immune microenvironment by increasing the infiltration of anti-tumor immune cells and reducing the infiltration of immunosuppressive immune cells.

ALDH1A1 drives prostate cancer metastases and radioresistance by interplay with AR- and RAR-dependent transcription.

Rationale: Current therapies for metastatic osseous disease frequently fail to provide a durable treatment response. To date, there are only limited therapeutic options for metastatic prostate cancer, the mechanisms that drive the survival of metastasis-initiating cells are poorly characterized, and reliable prognostic markers are missing. A high aldehyde dehydrogenase (ALDH) activity has been long considered a marker of cancer stem cells (CSC). Our study characterized a differential role of ALDH1A1 and ALDH1A3 genes as regulators of prostate cancer progression and metastatic growth. Methods: By genetic silencing of ALDH1A1 and ALDH1A3 in vitro, in xenografted zebrafish and murine models, and by comparative immunohistochemical analyses of benign, primary tumor, and metastatic specimens from patients with prostate cancer, we demonstrated that ALDH1A1 and ALDH1A3 maintain the CSC phenotype and radioresistance and regulate bone metastasis-initiating cells. We have validated ALDH1A1 and ALDH1A3 as potential biomarkers of clinical outcomes in the independent cohorts of patients with PCa. Furthermore, by RNAseq, chromatin immunoprecipitation (ChIP), and biostatistics analyses, we suggested the molecular mechanisms explaining the role of ALDH1A1 in PCa progression. Results: We found that aldehyde dehydrogenase protein ALDH1A1 positively regulates tumor cell survival in circulation, extravasation, and metastatic dissemination, whereas ALDH1A3 plays the opposite role. ALDH1A1 and ALDH1A3 are differentially expressed in metastatic tumors of patients with prostate cancer, and their expression levels oppositely correlate with clinical outcomes. Prostate cancer progression is associated with the increasing interplay of ALDH1A1 with androgen receptor (AR) and retinoid receptor (RAR) transcriptional programs. Polo-like kinase 3 (PLK3) was identified as a transcriptional target oppositely regulated by ALDH1A1 and ALDH1A3 genes in RAR and AR-dependent manner. PLK3 contributes to the control of prostate cancer cell proliferation, migration, DNA repair, and radioresistance. ALDH1A1 gain in prostate cancer bone metastases is associated with high PLK3 expression. Conclusion: This report provides the first evidence that ALDH1A1 and PLK3 could serve as biomarkers to predict metastatic dissemination and radiotherapy resistance in patients with prostate cancer and could be potential therapeutic targets to eliminate metastasis-initiating and radioresistant tumor cell populations.

The tumour thiolome as a potential target for anticancer drug development - time for a re-valuation of this area of cancer research.

This review is concerned with the role of various thiol constituents of the eukaryote cellular thiolome, particularly the part they play in the metabolism of tumour cells. The thiolome can be divided into two sections of high and low molecular weight thiol moieties and these are discussed. The impact of the discovery of high concentrations of a new unknown low molecular weight thiol in a tumour thiolome is also discussed. Its presence may have important ramifications in the search for new and more effective chemotherapeutic drugs to treat metastatic tumour cell growths.

Numerical Solution of Metastatic Tumor Growth Models With Treatment

Numerical Solution of Metastatic Tumor Growth Models With Treatment

Environment-responsive dendrobium polysaccharide hydrogel embedding manganese microsphere as a post-operative adjuvant to boost cascaded immune cycle against melanoma.

Rationale: Surgical resection is a primary treatment for solid tumors, but high rates of tumor recurrence and metastasis post-surgery present significant challenges. Manganese (Mn2+), known to enhance dendritic cell-mediated cancer immunotherapy by activating the cGAS-STING pathway, has potential in post-operative cancer management. However, achieving prolonged and localized delivery of Mn2+ to stimulate immune responses without systemic toxicity remains a challenge. Methods: We developed a post-operative microenvironment-responsive dendrobium polysaccharide hydrogel embedded with Mn2+-pectin microspheres (MnP@DOP-Gel). This hydrogel system releases Mn2+-pectin microspheres (MnP) in response to ROS, and MnP shows a dual effect in vitro: promoting immunogenic cell death and activating immune cells (dendritic cells and macrophages). The efficacy of MnP@DOP-Gel as a post-surgical treatment and its potential for immune activation were assessed in both subcutaneous and metastatic melanoma models in mice, exploring its synergistic effect with anti-PD1 antibody. Result: MnP@DOP-Gel exhibited ROS-responsive release of MnP, which could exert dual effects by inducing immunogenic cell death of tumor cells and activating dendritic cells and macrophages to initiate a cascade of anti-tumor immune responses. In vivo experiments showed that the implanted MnP@DOP-Gel significantly inhibited residual tumor growth and metastasis. Moreover, the combination of MnP@DOP-Gel and anti-PD1 antibody displayed superior therapeutic potency in preventing either metastasis or abscopal brain tumor growth. Conclusions: MnP@DOP-Gel represents a promising drug-free strategy for cancer post-operative management. Utilizing this Mn2+-embedding and ROS-responsive delivery system, it regulates surgery-induced immune responses and promotes sustained anti-tumor responses, potentially increasing the effectiveness of surgical cancer treatments.

A Case Report of Follow-up about a Yorkshire Dog with Multinodular Bone Tumor with Development of Pulmonary Metastasis

The multinodular bone tumor is a slow-growing, locally invasive malignant tumor capable of metastasizing. Its occurrence is greater in the flat bones of the skull and hard palate. The clinical signs depend on the location of tumor and are generally related to compression of adjacent structures. This report describes the follow-up of a case of multinodular bone tumor in a currently thirteen-year-old dog, Yorkshire Terrier breed, which was initially treated with neoformation in a region overlapping the topography of the left zygomatic arch and the caudal portion of the left mandibular branch. After performing a skull radiographic evaluation, computed tomography and laboratory investigation, surgical removal and histopathological examination were performed, which confirmed the suspicion of a multinodular bone tumor. Two years after surgery, pulmonary metastasis was found on the left side of the lung. At the time of this publication, the animal is in good general condition and without respiratory symptoms, despite progressive metastatic growth.

In Vitro and In Vivo Systems to Study Tumor Dormancy and the Transition to Overt Metastases Induced by the Fibrotic Milieu.

Metastatic breast cancer is a major cause of mortality among breast cancer patients (Sauer et al. Front Oncol: 11:659963, 2021). It may emerge years or even decades after the initial treatment of the primary tumor. This latency in the manifestation of the disease is attributed to the presence of early disseminated tumor cells (DTCs) that lay quiescent (dormant) for years until they emerge as clinically overt metastases. Given that to date we have no treatment to cure metastatic disease, it is vital to investigate ways to eradicate dormant DTCs and/or prevent their emergence to overt metastases. Here, we present a modified 3-dimensional in vitro system to model the in vivo growth characteristics of several tumor cell lines that exhibit either dormant behavior (D2.0R, MCF7) or transient dormant metastatic behavior (D2A1) at a metastatic secondary site. Additionally, we present an in vitro and complementary in vivo system to study the switch from dormancy to metastatic growth driven by a fibrotic-like milieu enriched with the deposition of type I collagen.

Deep learning-enabled detection of rare circulating tumor cell clusters in whole blood using label-free, flow cytometry.

Metastatic tumors have poor prognoses for progression-free and overall survival for all cancer patients. Rare circulating tumor cells (CTCs) and rarer circulating tumor cell clusters (CTCCs) are potential biomarkers of metastatic growth, with CTCCs representing an increased risk factor for metastasis. Current detection platforms are optimized for ex vivo detection of CTCs only. Microfluidic chips and size exclusion methods have been proposed for CTCC detection; however, they lack in vivo utility and real-time monitoring capability. Confocal backscatter and fluorescence flow cytometry (BSFC) has been used for label-free detection of CTCCs in whole blood based on machine learning (ML) enabled peak classification. Here, we expand to a deep-learning (DL)-based, peak detection and classification model to detect CTCCs in whole blood data. We demonstrate that DL-based BSFC has a low false alarm rate of 0.78 events per min with a high Pearson correlation coefficient of 0.943 between detected events and expected events. DL-based BSFC of whole blood maintains a detection purity of 72% and a sensitivity of 35.3% for both homotypic and heterotypic CTCCs starting at a minimum size of two cells. We also demonstrate through artificial spiking studies that DL-based BSFC is sensitive to changes in the number of CTCCs present in the samples and does not add variability in detection beyond the expected variability from Poisson statistics. The performance established by DL-based BSFC motivates its use for in vivo detection of CTCCs. Using transfer learning, we additionally validate DL-based BSFC on blood samples from different species and cancer cell types. Further developments of label-free BSFC to enhance throughput could lead to critical applications in the clinical detection of CTCCs and ex vivo isolation of CTCC from whole blood with minimal disruption and processing steps.