Downregulation of matriptase suppresses the PAR‑2/PLCγ2/PKC‑mediated invasion and migration abilities of MCF‑7 breast cancer cells

In silico analysis to explore the therapeutic potential of propolis-derived small molecules as matriptase inhibitors to suppress breast cancer growth and metastasis

Breast cancer is a major cause of death in women, and various drug therapies are used for its treatment. However, current therapies have many side effects and limitations. Propolis, a resinous product of bee hives, possesses a variety of biological activities, including anticancer and chemo-protective properties. The present study aimed to investigate the potential suitability of propolis-derived compounds to inhibit matriptase (MT-SP1), a potential protein target for breast cancer treatment, through comprehensive computational analysis. The MT-SP1 protein structure (PDB ID: 1EAX) was retrieved, energy-minimized, and validated. Five propolis-derived compounds with the highest binding energies to MT-SP1 were selected after virtual screening. Molecular docking of these selected ligands revealed binding energies ranging from -8.4 to -9.1 kcal/mol. Stable complex formation was validated by an additional 250 ns of molecular dynamics simulations. The HOMO-LUMO and DFT characteristics provided further evidence of the chemical reactivity and stability of these five ligands at the MT-SP1 active site. Screening of compounds for drug-likeness, pharmacokinetics (ADMET profiles), and toxicity identified two promising small molecules (PubChem IDs of ligands 72307 and 129827386) as potential drug candidates for inhibiting MT-SP1. However, experimental validation through in vitro or in vivo studies is necessary to confirm these computational findings and explore their therapeutic potential for breast cancer treatment.

Protease-activated receptor 2: A promising therapeutic target for women's cancers

Cancers affecting women, such as breast, uterine, ovarian, endometrial, and cervical cancers, have become increasingly prevalent. The growing incidence and death rates associated with these cancers warrant the development of innovative and alternative approaches to current treatments. This article investigates the association of women's cancers with a molecular target known as protease-activated receptor 2 (PAR2), a G protein-coupled receptor that is expressed on the surface of cancer cells. Expression levels of the PAR2 gene were curated from publicly available databases, and PAR2 was found to be significantly overexpressed in tissues from patients with breast, uterine, ovarian, endometrial, or cervical cancer compared with normal tissues. PAR2 overexpression has been previously linked to tumor progression and, in some cases, tumor growth. Activation of PAR2 by either endogenous proteases or synthetic agonists triggers certain downstream intracellular signaling pathways that have been associated with tumor progression, cell migration and invasion, angiogenesis, and apoptosis of cancer cells. Although recent advances have led to identification of several PAR2 antagonists, none has yet been developed for human use. Additionally, PAR2 inhibition has been shown to increase the efficacy of chemotherapeutic drugs, allowing them to be potentially used at less toxic doses in combination therapies for cancer. The present work briefly summarizes the current status of PAR2 as a potential therapeutic target for treating women's cancers. SIGNIFICANCE STATEMENT: This article highlights potential roles for protease-activated receptor 2 (PAR2) in cancers affecting women. Overexpression of the PAR2 gene in women's cancers is associated with various oncogenic processes, such as tumor progression, cell migration, and invasion, ultimately contributing to poorer patient prognoses. Given the increasing incidence of women's cancers, there is an urgent need to develop novel therapeutic drugs, and PAR2 represents a promising target for developing new treatments.

Role of NOX1 and NOX5 in protein kinase C/reactive oxygen species‑mediated MMP‑9 activation and invasion in MCF‑7 breast cancer cells

NADPH oxidases (NOXs) are a family of membrane proteins responsible for intracellular reactive oxygen species (ROS) generation by facilitating electron transfer across biological membranes. Despite the established activation of NOXs by protein kinase C (PKC), the precise mechanism through which PKC triggers NOX activation during breast cancer invasion remains unclear. The present study aimed to investigate the role of NOX1 and NOX5 in the invasion of MCF‑7 human breast cancer cells. The expression and activity of NOXs and matrix metalloprotease (MMP)‑9 were assessed by reverse transcription‑quantitative PCR and western blotting, and the activity of MMP‑9 was monitored using zymography. Cellular invasion was assessed using the Matrigel invasion assay, whereas ROS levels were quantified using a FACSCalibur flow cytometer. The findings suggested that NOX1 and NOX5 serve crucial roles in 12‑O‑tetradecanoylphorbol‑13‑acetate (TPA)‑induced MMP‑9 expression and invasion of MCF‑7 cells. Furthermore, a connection was established between PKC and the NOX1 and 5/ROS signaling pathways in mediating TPA‑induced MMP‑9 expression and cellular invasion. Notably, NOX inhibitors (diphenyleneiodonium chloride and apocynin) significantly attenuated TPA‑induced MMP‑9 expression and invasion in MCF‑7 cells. NOX1‑ and NOX5‑specific small interfering RNAs attenuated TPA‑induced MMP‑9 expression and cellular invasion. In addition, knockdown of NOX1 and NOX5 suppressed TPA‑induced ROS levels. Furthermore, a PKC inhibitor (GF109203X) suppressed TPA‑induced intracellular ROS levels, MMP‑9 expression and NOX activity in MCF‑7 cells. Therefore, NOX1 and NOX5 may serve crucial roles in TPA‑induced MMP‑9 expression and invasion of MCF‑7 breast cancer cells. Furthermore, the present study indicated that TPA‑induced MMP‑9 expression and cellular invasion were mediated through PKC, thus linking the NOX1 and 5/ROS signaling pathways. These findings offer novel insights into the potential mechanisms underlying their anti‑invasive effects in breast cancer.

Melitoxin Inhibits Proliferation, Metastasis, and Invasion of Glioma U251 Cells by Down-regulating F2RL1

As the principal active component of bee venom, melittin has an anti-cancer effect in different cancers. This study was aimed to investigate the effect of melittin in glioma and explore whether F2RL1 is closely involved in glioblastoma cells proliferation. TCGA and GES databases were used to evaluate the role of F2RL1 in gliomas. The U251 cells were divided into a control lentivirus + PBS group (NC-PBS), F2RL1 intervention lentivirus + PBS group (KD-PBS), control lentivirus + melittin group (NC-melittin), and F2RL1 intervention lentivirus + melittin group (KD-melittin). Cell proliferation was detected by MTT and EDU staining assays. The apoptosis rate was assessed by flow cytometry. Expressions of genes related to apoptosis, cycle arrest, migration, and invasion were detected by qRT-PCR. Cellular LDH concentrations were detected by ELISA. The subcutaneous tumor volume of nude mice was analyzed by xenograft method. F2RL1 was significantly overexpressed in glioma tissues and were reduced in the melittin-treated group compared to the blank group. F2RL1 knockdown and melittin alone or in combination increased the proportion of cells in the G1-phase, and the combination was more pronounced. The KD-melittin group showed a decrease in the number of viable cells at 24, 48, 72, and 96 h compared to the NC-PBS group. The number of cell migration and invasion was decreased in the KD-melittin group compared to the other groups. Moreover, the genes related to cell cycle arrest and apoptosis were significantly changed in the KD-melittin group. At weeks 4, 5, and 6, the tumor volume in the KD-melittin group was smaller than that in the KD-PBS group and NC-melittin group. Interference with the target gene F2RL1 inhibited the proliferation of glioma U251 cells, and melittin treatment inhibited the proliferation of glioma U251 cells. Melittin inhibited the proliferation of glioma U251 cells by suppressing the expression of target gene F2RL1.

The Progress of Platelets in Breast Cancer

Breast cancer is the most common female cancer and the sixth leading cause of death, seriously affecting the quality of life of women. Platelets, one of the fragments derived from megakaryocytes, are being increasingly investigated by tumor researchers because of their anticoagulant function. According to relevant studies, platelets, as the key source of circulating angiogenesis-related factors, can regulate tumor angiogenesis and vascular integrity, and they can also affect the tumor microenvironment, thereby facilitating the proliferation and differentiation of tumor cells. By covering or transferring normal MHC I molecules to tumor cells, platelets can protect tumor cells from being killed by the immune system and facilitate tumor cell metastasis. However, details on the mechanisms involved have remained elusive. This paper reviews and analyzes studies of the role of platelets in tumorigenesis, tumor cell proliferation, tumor metastasis, and cancer treatment to provide readers with a better understanding of the relevant studies.

BTK Isoforms p80 and p65 Are Expressed in Head and Neck Squamous Cell Carcinoma (HNSCC) and Involved in Tumor Progression

Here, we describe the expression of Bruton's Tyrosine Kinase (BTK) in head and neck squamous cell carcinoma (HNSCC) cell lines as well as in primary HNSCC samples. BTK is a kinase initially thought to be expressed exclusively in cells of hematopoietic origin. Apart from the 77 kDa BTK isoform expressed in immune cells, particularly in B cells, we identified the 80 kDa and 65 kDa BTK isoforms in HNSCC, recently described as oncogenic. Importantly, we revealed that both isoforms are products of the same mRNA. By investigating the mechanism regulating oncogenic BTK-p80/p65 expression in HNSSC versus healthy or benign tissues, our data suggests that the epigenetic process of methylation might be responsible for the initiation of BTK-p80/p65 expression in HNSCC. Our findings demonstrate that chemical or genetic abrogation of BTK activity leads to inhibition of tumor progression in terms of proliferation and vascularization in vitro and in vivo. These observations were associated with cell cycle arrest and increased apoptosis and autophagy. Together, these data indicate BTK-p80 and BTK-p65 as novel HNSCC-associated oncogenes. Owing to the fact that abundant BTK expression is a characteristic feature of primary and metastatic HNSCC, targeting BTK activity appears as a promising therapeutic option for HNSCC patients.

Downregulation of Matriptase Inhibits Porphyromonas gingivalis Lipopolysaccharide-Induced Matrix Metalloproteinase-1 and Proinflammatory Cytokines by Suppressing the TLR4/NF-κB Signaling Pathways in Human Gingival Fibroblasts

Matriptases are cell surface proteolytic enzymes belonging to the type II transmembrane serine protease family that mediate inflammatory skin disorders and cancer progression. Matriptases may affect the development of periodontitis via protease-activated receptor-2 activity. However, the cellular mechanism by which matriptases are involved in periodontitis is unknown. In this study, we examined the antiperiodontitis effects of matriptase on Porphyromonas gingivalis-derived lipopolysaccharide (PG-LPS)-stimulated human gingival fibroblasts (HGFs). Matriptase small interfering RNA-transfected HGFs were treated with PG-LPS. The mRNA and protein levels of proinflammatory cytokines and matrix metalloproteinase 1 (MMP-1) were evaluated using the quantitative real-time polymerase chain reaction (qRT-PCR) and an enzyme-linked immunosorbent assay (ELISA), respectively. Western blot analyses were performed to measure the levels of Toll-like receptor 4 (TLR4)/interleukin-1 (IL-1) receptor-associated kinase (IRAK)/transforming growth factor β-activated kinase 1 (TAK1), p65, and p50 in PG-LPS-stimulated HGFs. Matriptase downregulation inhibited LPS-induced proinflammatory cytokine expression, including the expression of IL-6, IL-8, tumor necrosis factor-α (TNF-α), and IL-Iβ. Moreover, matriptase downregulation inhibited PG-LPS-stimulated MMP-1 expression. Additionally, we confirmed that the mechanism underlying the effects of matriptase downregulation involves the suppression of PG-LPS-induced IRAK1/TAK1 and NF-κB. These results suggest that downregulation of matriptase PG-LPS-induced MMP-1 and proinflammatory cytokine expression via TLR4-mediated IRAK1/TAK1 and NF-κB signaling pathways in HGFs.

Methamphetamine induces transcriptional changes in cultured HIV-infected mature monocytes that may contribute to HIV neuropathogenesis

HIV-associated neurocognitive impairment (HIV-NCI) persists in 15-40% of people with HIV (PWH) despite effective antiretroviral therapy. HIV-NCI significantly impacts quality of life, and there is currently no effective treatment for it. The development of HIV-NCI is complex and is mediated, in part, by the entry of HIV-infected mature monocytes into the central nervous system (CNS). Once in the CNS, these cells release inflammatory mediators that lead to neuroinflammation, and subsequent neuronal damage. Infected monocytes may infect other CNS cells as well as differentiate into macrophages, thus contributing to viral reservoirs and chronic neuroinflammation. Substance use disorders in PWH, including the use of methamphetamine (meth), can exacerbate HIV neuropathogenesis. We characterized the effects of meth on the transcriptional profile of HIV-infected mature monocytes using RNA-sequencing. We found that meth mediated an upregulation of gene transcripts related to viral infection, cell adhesion, cytoskeletal arrangement, and extracellular matrix remodeling. We also identified downregulation of several gene transcripts involved in pathogen recognition, antigen presentation, and oxidative phosphorylation pathways. These transcriptomic changes suggest that meth increases the infiltration of mature monocytes that have a migratory phenotype into the CNS, contributing to dysregulated inflammatory responses and viral reservoir establishment and persistence, both of which contribute to neuronal damage. Overall, our results highlight potential molecules that may be targeted for therapy to limit the effects of meth on HIV neuropathogenesis.