Understanding the role of biased taste T1R2/T1R3 G protein-coupled receptors (GPCR) agonists on glycosylated receptor signaling may provide insights into the opposing effects mediated by artificial and natural sweeteners, particularly in cancer and metastasis. Sweetener-taste GPCRs can be activated by several active states involving either biased agonism, functional selectivity, or ligand-directed signaling. However, there are increasing arrays of sweetener ligands with different degrees of allosteric biased modulation that can vary dramatically in binding- and signaling-specific manners. Here, emerging evidence proposes the involvement of taste GPCRs in a biased GPCR signaling crosstalk involving matrix metalloproteinase-9 (MMP-9) and neuraminidase-1 (Neu-1) activating glycosylated receptors by modifying sialic acids. The findings revealed that most natural and artificial sweeteners significantly activate Neu-1 sialidase in a dose-dependent fashion in RAW-Blue and PANC-1 cells. To confirm this biased GPCR signaling crosstalk, BIM-23127 (neuromedin B receptor inhibitor, MMP-9i (specific MMP-9 inhibitor), and oseltamivir phosphate (specific Neu-1 inhibitor) significantly block sweetener agonist-induced Neu-1 sialidase activity. To assess the effect of artificial and natural sweeteners on the key survival pathways critical for pancreatic cancer progression, we analyzed the expression of epithelial-mesenchymal markers, CD24, ADLH-1, E-cadherin, and N-cadherin in PANC-1 cells, and assess the cellular migration invasiveness in a scratch wound closure assay, and the tunneling nanotubes (TNTs) in staging the migratory intercellular communication. The artificial and natural sweeteners induced metastatic phenotype of PANC-1 pancreatic cancer cells to promote migratory intercellular communication and invasion. The sweeteners also induced the downstream NFκB activation using the secretory alkaline phosphatase (SEAP) assay. These findings elucidate a novel taste T1R2/T1R3 GPCR functional selectivity of a signaling platform in which sweeteners activate downstream signaling, contributing to tumorigenesis and metastasis via a proposed NFκB-induced epigenetic reprogramming modeling.

Cytokines can promote various cancer processes, such as angiogenesis, epithelial to mesenchymal transition (EMT), invasion, and tumor progression, and maintain cancer stem-cell-like (CSCs) cells. The mechanism(s) that continuously promote(s) tumors to progress in the TME still need(s) to be investigated. The data in the present study analyzed the inflammatory, angiogenic, fibrogenic, and angiostatic cytokine profiles in the host serum during tumor development in a mouse model of human pancreatic cancer. Pancreatic MiaPaCa-2-eGFP cancer cells were subcutaneously implanted in RAG2xCγ double mutant mice. Blood samples were collected before cancer cell implantation and every week until the end point of the study. The extracted serum from the blood of each mouse at different time points during tumor development was analyzed using a Bio-Plex microarray analysis and a Bio-Plex 200 system for proinflammatory (IL-1β, IL-10, IFN-γ, and TNF-α) and angiogenic and fibrogenic (IL-15, IL-18, basic FGF, LIF, M-CSF, MIG, MIP-2, PDGF-BB, and VEGF) cytokines. Here, we find that during cancer cell colonization for tumor development, host angiogenic, fibrogenic, and proinflammatory cytokine profiling in the tumor-bearing mice has been shown to significantly reduce host angiostatic and proinflammatory cytokines that restrain tumor development and increase those for tumor growth. The proinflammatory cytokines IL-15, IL-18, and IL-1β profiles reveal a significant host serum increase after day 35 when the tumor began to progress in growth. In contrast, the angiostatic cytokine profiles of TNFα, MIG, M-CSF, IL-10, and IFNγ in the host serum revealed a dramatic and significant decrease after day 5 post-implantation of cancer cells. OP treatment of tumor-bearing mice on day 35 maintained high levels of angiostatic and fibrogenic cytokines. The data suggest an entirely new regulation by cancer cells for tumor development. The findings identify for the first time how pancreatic cancer cells use host cytokine profiling to orchestrate the initiation of tumor development.

Background/Objectives: The significance of cytokine signaling on cancer progression and metastasis has raised interest in cancer research over the last few decades. Here, we analyzed the effects of three cytokines that we previously reported are significantly upregulated rapidly after the surgical removal of primary breast, colorectal, and prostate cancer. We also investigated the regulation of their cognate receptors. Methods: All experiments were conducted using the PANC-1, SW620, and MCF-7 cell lines, treated with three different cytokines (TGF-β1, HGF, and IL-6). The effect of these cytokines on the expression of epithelial–mesenchymal transition (EMT) cell surface markers and neuraminidase-1 activity was measured via fluorescent microscopy and image analysis software. Results: The findings show that these cytokines increase the expression of mesenchymal markers while reducing epithelial markers, corresponding to the EMT process. A strong link between cytokine receptor signaling and the Neu-1-MMP-9-GPCR crosstalk was identified, suggesting that cytokine receptor binding leads to increased Neu-1 activity and subsequent signaling pathway activation. Oseltamivir phosphate (OP) prevented sialic acid hydrolysis by neuraminidase-1 (Neu-1), leading to the downregulation of these signaling cascades. Conclusions: In concert with the previous work revealing the role of Neu-1 in regulating other glycosylated receptors implicated in cancer cell proliferation and EMT, targeting Neu-1 may provide effective treatment against a variety of malignancies. Most significantly, the treatment of patients with specific inhibitors of Neu-1 soon after primary cancer surgery may improve our ability to cure early-stage cancer by inhibiting the EMT process and disrupting the ability of any residual cancer cell population to metastasize.

Metastasizing cancer cells surreptitiously can adapt to metabolic activity during their invasion. By initiating their communications for invasion, cancer cells can reprogram their cellular activities to initiate their proliferation and migration and uniquely counteract metabolic stress during their progression. During this reprogramming process, cancer cells’ metabolism and other cellular activities are integrated and mutually regulated by tunneling nanotube communications to alter their specific metabolic functional drivers of tumor growth and progression. Here, we investigated the in vitro effects of the synthetic CB1 cannabinoids AM-404, arvanil, and olvanil on human pancreatic PANC-1 and colorectal SW-620 cancer cell lines to understand further cellular behaviors and the potential risks of their use in cancer therapy. For the first time, the synthetic CB1 cannabinoids AM-404, arvanil, and olvanil significantly altered cancer cells in forming missile-like shapes to induce tunneling nanotube (TNT) communications in PANC-1 cells. Oseltamivir phosphate (OP) significantly prevented TNT formation. To assess the key survival pathways critical for pancreatic cancer progression, we used the AlamarBlue assay to determine synthetic CB1 cannabinoids to induce the cell’s metabolic viability drivers to stage migratory intercellular communication. The synthetic CB1 cannabinoids significantly increased cell viability compared to the untreated control for PANC-1 and SW-620 cells, and this response was significantly reduced with the NMBR inhibitor BIM-23127, neuraminidase-1 inhibitor OP, and MMP-9 inhibitor (MMP-9i). CB1 cannabinoids also significantly increased N-cadherin and decreased E-cadherin EMT markers compared to the untreated controls, inducing the process of metastatic phenotype for invasion. BIM-23127, MMP9i, and OP significantly inhibited CB1 agonist-induced NFκB-dependent secretory alkaline phosphatase (SEAP) activity. To confirm this concept, we investigated the migratory invasiveness of PANC-1 and SW-620 cancer cells treated with the synthetic CB1 cannabinoids AM-404, arvanil, and olvanil in a scratch wound assay. CB1 cannabinoids significantly induced the rate of migration and invasiveness of PANC-1 cancer cells, whereas they had minimal effect on the rate of migration of already metastatic SW-620 cancer cells. Interestingly, olvanil-treated SW-620 cells significantly enhanced the migration rate and invasiveness of these cells. The data support the cellular and molecular mechanisms of the synthetic CB1 cannabinoids, orchestrating intercellular conduits to enhance metabolic drivers to stage migratory intercellular communication in pancreatic cancer cells.

Background /Objectives: The SARS-CoV-2’s high mutations and replication rates contribute to its high infectivity and resistance to current vaccinations and treatments. The primary cause of resistance to most current treatments aligns within the coding regions for the spike S protein of SARS-CoV-2 that has mutated. As a potential novel immunotherapy, we generated a novel fusion protein composed of a soluble ACE2 (sACE2) linked to llama-derived anti-CD16 that targets different variants of spike proteins and enhances natural killer cells to target infected cells. Methods: Here, we generated a novel sACE2-AntiCD16VHH fusion protein using a Gly4Ser linker, synthesized and cloned into the pLVX-EF1alpha-IRES-Puro vector, and further expressed in ExpiCHO-S cells and purified using Ni⁺NTA chromatography. Results: The fusion protein significantly blocked SARS-CoV-2 alpha, beta, delta, gamma, and omicron S-proteins binding and activating angiotensin-converting enzyme receptor-2 (ACE2) on ACE2-expressing RAW-Blue macrophage cells and the secretion of several key inflammatory cytokines, G-CSF, MIP-1A, and MCP-1, implicated in the cytokine release storm (CRS). The sACE2-Anti-CD16VHH fusion protein also bridged NK cells to ACE2-expressing human lung carcinoma A549 cells and significantly activated NK-dependent cytotoxicity. Conclusions: The findings show that a VHH directed against CD16 could be an excellent candidate to be linked to soluble ACE2 to generate a bi-specific molecule (sACE2-AntiCD16VHH) suitable for bridging effector cells and infected target cells to inhibit SARS-CoV-2 variant spike proteins binding to the ACE2 receptor in the RAW-Blue cell line and pro-inflammatory cytokines and to activate natural killer cell cytotoxicity.

Background: When tumors are surgically removed, an immediate rise in circulating tumor cells is often observed, accompanied by several postoperative changes that can enable these cells to evade immune detection and metastasize. The perioperative period following tumor resection can often promote the formation of new distant micrometastatic foci triggered by upregulation of distinct molecules. Our lab previously reported an increase in distinct inflammatory cytokine molecules following surgical resection in prostate, breast, and colorectal cancer patients, and the secretion of these signals begins as early as 2–24 h after surgery. Here, we investigated whether these distinct cytokines could orchestrate the formation of tunneling nanotube (TNT) conduits to enhance cancer cell migration. Methods and Results: Here, we provide supporting evidence that specific pro-inflammatory cytokines upregulated following cancer surgery may be potential triggers of disease recurrence and migration through TNT formation. In the tumor microenvironment, TNTs act as conduits between cancer and normal cells, facilitating the transfer of organelles that contribute to cancer cell survival and metastasis. Here, The effects of TGF-β1, IL-6, and HGF cytokines on the development of TNT conduits between adjacent cancer cells, as well as the effects of oseltamivir phosphate (OP) treatment, were measured using fluorescent microscopy and image analysis software. In PANC-1 pancreatic cancer cells, the addition of these cytokines significantly increased (p < 0.009) the quantity and extent of TNTs compared with untreated control cells. MCF-7 breast cancer cells yielded comparable results, with a significant increase in TNT observed in cells treated with TGFβ-1, IL-6, and HGF. In contrast, SW620 colorectal cancer cells did not express TNTs in response to any of the three cytokines tested. OP treatment with cytokines significantly reduced TNT formation in pancreatic and breast cancer cells, with no effect on the colorectal SW620 cancer cell line. Cell migration in response to cytokines was assessed using the scratch wound assay. Out of the three cell lines analyzed, the PANC-1 cells fully closed after 12 h of the wound gap. In contrast, the SW620 and MCF-7 cells had no significant change in wound closure rate following cytokine treatment. The SW620 cells exhibited a slight but insignificant increase in the wound closure rate with TGFβ-1 and HGF treatment, while IL-6 in the SW620 cells and all three cytokines in the MCF-7 cells were comparable to the control. OP significantly reduced the scratch wound closure rate on PANC-1, SW620, and MCF-7 cells treated with these cytokines. Conclusions: These findings further support the link between perioperative cytokine activity and increased metastatic potential by promoting the formation of intercellular tunneling nanotube conduits. OP, a specific inhibitor of the mammalian neuraminidase-1 (NEU-1) enzyme, disrupts this process.