Human Squamous Cell Carcinoma Research Articles

Effect of plasma-induced oxidation on NK cell immune checkpoint ligands: A computational-experimental approach

Non-thermal plasma (NTP) shows promise as a potent anti-cancer therapy with both cytotoxic and immunomodulatory effects. In this study, we investigate the chemical and biological effects of NTP-induced oxidation on several key, determinant immune checkpoints of natural killer (NK) cell function. We used molecular dynamics (MD) and umbrella sampling simulations to investigate the effect of NTP-induced oxidative changes on the MHC-I complexes HLA-Cw4 and HLA-E. Our simulations indicate that these chemical alterations do not significantly affect the binding affinity of these markers to their corresponding NK cell receptor, which is supported with experimental read-outs of ligand expression on human head and neck squamous cell carcinoma cells after NTP application. Broadening our scope to other key ligands for NK cell reactivity, we demonstrate rapid reduction in CD155 and CD112, target ligands of the inhibitory TIGIT axis, and in immune checkpoint CD73 immediately after treatment. Besides these transient chemical alterations, the reactive species in NTP cause a cascade of downstream cellular reactions. This is underlined by the upregulation of the stress proteins MICA/B, potent ligands for NK cell activation, 24 h post treatment. Taken together, this work corroborates the immunomodulatory potential of NTP, and sheds light on the interaction mechanisms between NTP and cancer cells.

Differential molecular characterization of human papillomavirus-associated oropharyngeal squamous cell carcinoma and its prognostic value.

Human papillomavirus (HPV) infection is a causative factor in the occurrence and progression of oropharyngeal squamous cell carcinoma (OPSCC). In recent years, clinical studies have found that HPV-positive OPSCC patients may present a better prognosis than HPV-negative patients, yet the underlying causes are unclear. This study aimed to investigate the relevance of HPV infection and the prognosis of OPSCC. On this basis, we aimed to establish a prediction model to accurately predict the prognosis and guide clinical practice. We analysed the records of 233 patients with OPSCC. Cox regression was applied to identify factors associated with survival. Moreover, variables with significant discrepancies were integrated into a nomogram model to predict prognosis. The results showed that HPV was an independent prognostic factor for OS and PFS. Immunoglobulin Heavy Constant Mu (IGHM) mRNA was significantly upregulated in patients with HPV-positive OPSCC. Crucially, IGHM expression was associated with better prognosis. The receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis both confirmed that the prognostic model exhibits good performance. In summary, HPV infection were independent prognostic factors for OPSCC. IGHM may be the key contributors to the prognostic differences in HPV-associated OPSCC. This nomogram model was able to accurately predict the prognosis of patients.

200 (PB188): Cornulin, detected through electroporation based molecular sampling, discriminates between human basal cell carcinoma and squamous cell carcinoma

200 (PB188): Cornulin, detected through electroporation based molecular sampling, discriminates between human basal cell carcinoma and squamous cell carcinoma

Collagen prolyl 4-hydroxylase subunit α member-induced head and neck squamous cell carcinoma aggressiveness is antagonized by LLGL2 via reduced expression of occludin.

There are three isoforms of human collagen prolyl 4-hydroxylases (C-P4Hs), each of which has been reported to play an important role in regulating the progression of a variety of human cancers. By analyzing TGCA datasets on human head and neck squamous cell carcinoma (HNSC), we find that a higher expression of all three C-P4HAs (the α subunit of C-P4Hs) is a superior prognostic indicator than a higher expression of two or a single C-P4HA. Unexpectedly, some patients with higher levels of three C-P4HAs survive longer than patients whose tumors have lower expression of C-P4HAs. Therefore, there may be molecule(s) that can negate the deleterious effects of overexpressing C-P4HAs during cancer progression. By constructing a functional protein interaction network of C-P4HAs and analyzing molecules whose expressions are correlated significantly with that of C-P4HAs, we identify scribble cell polarity complex component 2 (LLGL2) as a factor that antagonizes the effects of overexpressed C-P4HAs on HNSC. Silencing of LLGL2 in the human oral squamous cell line Cal-27 upregulates the expression of occludin and increases cancer cell invasion and migration. In contrast, knocking down C-P4HA alone inhibits cell migration and invasion. Furthermore, simultaneously downregulating three C-P4HAs has more pronounced effects on inhibiting cell migration and invasion. Accordingly, high LLGL2 expression is also a marker indicating improved prognosis in patients with HNSC. These results suggest that the interplay between LLGL2 and C-P4HAs may be targeted to mitigate HNSC tumorigenesis and progression.

The expression of immune checkpoint proteins PD-L1 and TIM3 in mouse and human head and neck squamous cell carcinoma.

The aim of this study was to examine the expression of programmed death-ligand 1 (PD-L1) and of T cell immunoglobulin and mucin domain-containing protein (TIM3) in oral epithelial dysplasia and head and neck squamous cell carcinoma (HNSCC). Mouse HNSCC was induced with 4-nitroquinoline-1 oxide (4NQO). Oral epithelial dysplastic lesions, carcinoma in situ and HNSCC lesions were stained with anti-PD-L1 and TIM3 antibodies. The expression of PD-L1 and TIM3 in tumor cells and immune cells was semiquantitatively measured and compared. In parallel, human dysplasia and HNSCC were stained with anti-PD-L1 and anti-TIM3. The expression pattern of PD-L1+ and TIM3+ cells was further compared. In human and mouse samples both PD-L1 and TIM3 were found to be expressed in neoplastic and immune cells in HNSCC, but not in dysplasia. There was no significant difference in PD-L1 and TIM3 expression between metastatic and nonmetastatic HNSCC. We conclude that the 4NQO-induced mouse HNSCC model may be an excellent preclinical model for immune checkpoint therapy.

Exploring a specific type of tissue-resident natural killer cell involved in the anti-tumor and immunotherapy response in human papillomavirus-positive head and neck squamous cell carcinoma using scRNA-seq

Exploring a specific type of tissue-resident natural killer cell involved in the anti-tumor and immunotherapy response in human papillomavirus-positive head and neck squamous cell carcinoma using scRNA-seq

The critical role of Gαi3 in oral squamous cell carcinoma cell growth.

The identification of novel and effective therapeutic targets for oral squamous cell carcinoma (OSCC) is of paramount importance. This study investigates the expression, potential functions, and mechanistic insights of G protein inhibitory subunit 3 (Gαi3) in OSCC. Gαi3 is found to be upregulated in human OSCC tissues as well as in various primary and established OSCC cells. In different OSCC cells, silencing of Gαi3 through shRNA resulted in inhibited cell proliferation and migration, while also inducing apoptosis. Knockout (KO) of Gαi3 via the CRISPR/Cas9 method produced significant anti-cancer effects in OSCC cells. Conversely, ectopic overexpression of Gαi3 enhanced OSCC cell growth, promoting cell proliferation and migration. Gαi3 plays a crucial role in activating the Akt-mTOR signaling pathway in OSCC cells. Silencing or KO of Gαi3 led to decreased phosphorylation levels of Akt and S6K, whereas overexpression of Gαi3 increased their phosphorylation. Restoration of Akt-mTOR activation through a constitutively active mutant Akt1 mitigated the anti-OSCC effects induced by Gαi3 shRNA. In vivo, Gαi3 silencing significantly suppressed the growth of subcutaneous OSCC xenografts in nude mice, concomitant with inactivation of the Akt-mTOR pathway and induction of apoptosis. Collectively, these findings underscore the critical role of Gαi3 in OSCC cell growth both in vitro and in vivo.

Cytotoxic Effect of Bajong LN Rice Methanol Extract on Human Squamous Cell Carcinoma, ORL-48

Oral squamous cell carcinoma (OSCC), a major oral cancer, significantly challenges treatments and impacts patient quality of life; current therapies often cause severe side effects, highlighting the urgent need for gentler alternatives. Rice stands as one of the primary cereal grains providing the daily caloric intake for more than half of the global population. Extensive research has demonstrated the significant health benefits derived from rice, attributed to its abundance of bioactive compounds. This study endeavours to explore the potential cytotoxic effects of Bajong LN rice, a pigmented purple rice indigenous to Sarawak, on human squamous cell carcinoma, ORL-48 cells. Cells were cultured in complete DMEM/F-12 media and incubated under standard culture conditions. Upon reaching 80% confluency, the cells were treated to varied concentrations (ranging from 0 μg/ml to 2000 μg/ml) of Bajong LN rice methanol extract (BLN-ME) and cisplatin. Subsequently, the cells were incubated for 48 and 72 hours, and their cytotoxicity was assessed using the MTS assay. Results demonstrated that cisplatin inhibited ORL-48 cells with an IC50 of 7.483 μg/ml and 3.877 μg/ml; and an IC80 of 40.649 μg/ml; and 17.543 μg/ml for 48 and 72 hours, respectively. Correspondingly, BLN-ME exhibited a notable cytotoxic effect against ORL-48 cells at 48- and 72-hour intervals, with an IC50 of 354.4 μg/ml and 342.0 μg/ml; and an IC80 of 450.3 μg/ml and 423.63 μg/ml, respectively. The cytotoxic activity of BLN-ME against ORL-48 cells was observed in both a time and dose-dependent manner. Morphological analysis and the Trypan blue exclusion assay corroborated the MTS assay's findings. Our preliminary findings provide the first scientific evidence of the cytotoxic effect of BLN-ME specifically against human squamous cell carcinoma, ORL-48 cells. This study suggests the potential of BLN-ME as a promising anti-cancer agent, presenting opportunities for further investigation into its underlying cytotoxic mechanisms.

Apoptotic effect of betulinic acid in FaDu human head and neck squamous cell carcinomas

Apoptotic effect of betulinic acid in FaDu human head and neck squamous cell carcinomas

Cancer Cell-Selective Inhibition of Migration by Styrenic Catiomer Emulsions.

Cancer metastasis remains the most formidable cause of mortality and morbidity in cancer patients. Developing an effective and economical method toward cancer antimetastatic strategy demands immediate attention in anticancer therapy. Herein, we followed a cost-effective greener method for preparing a small family of amphiphilic catiomers with varied styrene content (45, 63, and 83%), which revealed the unique potential of promoting normal cell migration while retarding cancer metastasis. The styrenic polymers formed micellar self-assembly in aqueous phase and exhibited a cationic charge. Polymers were quite nontoxic up to 200 μg/mL concentration toward human embryonic kidney cell HEK293 as well as human, triple negative breast cancer cell MDAMB-231, mouse melanoma cell B16F10, and human oral squamous carcinoma cell FaDu. Confocal imaging and fluorescence activated cell sorting (FACS) showed effective incorporation of polymers within cells. Interestingly, the polymer-treated HEK293 cells underwent prominent wound healing in scratch assay. However, the as-synthesized polymer-treated cancer cells resisted migration as analyzed from the scratch assay. A mechanistic study using immunoblotting assay established upregulation of migratory proteins vimentin and TGF-β and downregulation of E-cadherin in normal HEK293 cells. Remarkably, this trend was completely reversed in cancer cell MDAMB-231. This study describes the extraordinary potential of styrenic catiomers as wound healers for normal cells while inhibiting cancer metastasis.

Betaine Induces Apoptosis and Inhibits Invasion in OSCC Cell Lines.

Betaine, known as trimethylglycine, is a non-toxic natural substance reported to affect cancer cell responses. This study delves into the impact of betaine on the survival, proliferation, and invasion of oral squamous cell carcinoma (OSCC) cells in vitro. Human OSCC cells (HSC-4 and HSC-7) were subjected to varying concentrations of betaine, and their viability and proliferation were assessed through colourimetric MTT and colony-forming unit assays. Cell cycle progression and cell apoptosis were also investigated using flow cytometry, while cell migration and invasion were examined using a transwell migration assay, and the mRNA expression was evaluated by a quantitative polymerase chain reaction. Finally, proteomic analysis was conducted through liquid chromatography-tandem mass spectrometry on the extracted protein component of the cells. Results indicate that betaine effectively suppressed OSCC proliferation and colony formation. It triggered early apoptosis without disrupting cell cycle progression, reduced cell migration, and inhibited invasion. Betaine exposure led to significantly decreased mRNA levels of MMP1, MMP2, and MMP9 while downregulating FN1, a gene linked to epithelial-to-mesenchymal transition. Proteomic analysis revealed 9240 differentially expressed up/downregulated proteins in cells treated with betaine. The significantly upregulated proteins were associated with ATP-binding cassette (ABC) transporters, while the down-regulated proteins were associated with G protein-coupled receptors (GPCR) ligand binding. In conclusion, betaine exhibits potent anti-cancer properties by attenuating OSCC cell proliferation and mitigating invasion. Exploring this natural product as an adjunct for managing oral squamous cell carcinoma shows promise, although further investigations are needed to fully elucidate its functionality.

Inhibition of Oral Pathogenic Bacteria, Suppression of Bacterial Adhesion and Invasion on Human Squamous Carcinoma Cell Line (HSC-4 Cells), and Antioxidant Activity of Plant Extracts from Acanthaceae Family.

Medicinal plants have traditionally been used to treat various human diseases worldwide. In this study, we evaluated the leaf extracts of plants from the Acanthaceae family, specifically Clinacanthus nutans (Burm.f.) Lindau, Thunbergia laurifolia Lindl., and Acanthus ebracteatus Vahl., for their compounds and antioxidant activity. The ethanolic extracts of A. ebracteatus showed the highest total phenolic content at 22.55 mg GAE/g extract and the strongest antioxidant activities, with IC50 values of 0.24 mg/mL and 3.05 mg/mL, as determined by DPPH and ABTS assays. The antibacterial efficacy of these extracts was also tested against Streptococcus pyogenes, Streptococcus mutans, Staphylococcus aureus, and Klebsiella pneumoniae. The diameters of the inhibition zones ranged from 14.7 to 17.3 mm using the agar well diffusion method, with MIC and MBC values ranging from 7.81 to 250 mg/mL. Anti-biofilm formation, antibacterial adhesion, and antibacterial invasion assays further demonstrated that these medicinal plant extracts can inhibit bacterial biofilm formation and prevent the adhesion and invasion of oral pathogenic bacteria on the human tongue squamous cell carcinoma-derived cell line (HSC-4 cells). The ethanolic extracts of C. nutans and A. ebracteatus were able to inhibit the gtfD and gbp genes, which facilitate biofilm formation and bacterial adherence to surfaces. These findings provide new insights into the antibacterial and antioxidant properties of plant extracts from the Acanthaceae family. These activities could enhance the clinical and pharmaceutical applications of plant extracts as an alternative therapy for bacterial infections and a dietary supplement.

Landscape of epithelial cell subpopulations in the human esophageal squamous cell carcinoma microenvironment

AimsWe sought to reveal the landscape of epithelial cell subpopulations in the human esophageal squamous cell carcinoma microenvironment and investigate their parts on esophageal squamous carcinoma (ESCC) development. BackgroundEpithelial cells play an important role in the occurrence and development of ESCC through multiple mechanisms. While the landscape of epithelial cell subpopulations in ESCC, remains unclear. ObjectiveExploring the role of epithelial cell subpopulations in ESCC progression. MethodsSeurat R package was used for single-cell RNA sequencing (scRNA-seq) data filtering, dimensionality reduction, clustering and differentially expressed genes analysis. Cellmarker database was adopted for cell cluster annotation. Functional enrichment analysis was carried out by Gene Ontology (GO) analysis. InferCNV package was conducted for copy number variation (CNV) of epithelial cell subpopulations in all chromosomal regions. Pseudotime trajectory analysis was implemented for exploring differentiation trajectory of epithelial cells subgroups during the cancer progression. CellChat analysis was used for probing the interactions between epithelial cells and NK/T cells. cellular experiments were performed using Quantitative Real-Time Polymerase Chain Reaction (RT-qPCR), Wound-Healing Assay and transwell. Results11 major cell subpopulations were identified in ESCC and adjunct tissues. Further reclassification of epithelial cells uncovered 4 subpopulations. Enrichment analysis revealed that highly expressed genes in 4 epithelial cell subpopulations were related to cell proliferation, immune response and angiogenesis. CNV analysis found that UBD + epithelial cells and GAS2L3+ epithelial cells had a higher proportion of CNV. Cell differentiation trajectories disclosed that KRT6C+ and GSTA1+ epithelial cells were in an intermediate state of differentiation, while UBD+ and GAS2L3+ epithelial cells are in an end state of differentiation during ESCC progression. Finally, we found that four epithelial cell subpopulations all inhibited NK/T cells through NECTIN2-TIGIT and CLEC2B-KLRB1. Low ATF3 and DDIT3 mRNA expression inhibited ESCC cell migration and invasion. ConclusionHere, we obtained a through epithelial cell atlas of ESCC at single-cell resolution, explored the role of epithelial cell in ESCC progression, and unveiled immunosuppressive signals to NK/T cells in promoting ESCC. Our findings expand the comprehension of epithelial cells and offer a theoretical guidance for future anti-epithelial cell treatment of ESCC.

The cytotoxic effect of 4 different wavelengths of Low-level laser therapy on squamous cell carcinoma – An invitro study

Background: Low-level laser therapy is a noninvasive method with the potential ability to change the balance of cell mediators and gene expressions. It affects cellular function resulting in beneficial clinical effects. This study aims to assess the effect of low-level light therapy (LLLT) using four different laser wavelengths on oral carcinoma cell viability in vitro. Methods and Material: HN5 human head and neck squamous cell carcinoma cell lines (HNSCC) were cultured and irradiated using four wavelengths of blue (485 nm), green (532nm), red (660 nm), and near Infra-red (810 nm) in a continuous mode with a dose of 1 J/cm2 (0.1W, 10sec) every 24hours for five consecutive days. Cell viability was assessed by evaluating mitochondrial activity by MTT assay. Results: All the wavelengths resulted in reduced viability of these cells compared to the controls. (P<0.05) There were statistically significant differences in cell viability between different wavelengths (P<0.001). The 810 nm laser irradiation showed the highest percentage of cell survival (55.92%) while 660 nm induced the lowest (36.02%). Conclusion: Different laser wavelengths may result in different effects on irradiated cells and red irradiation showed the lowest cell viability and the infrared laser had the highest cell viability results.

Establishment and biological characteristics of a human buccal mucosa squamous cell carcinoma cell line SCC117

Objective: To establish a human buccal mucosa squamous cell carcinoma (BMSCC) cell line SCC117 in China, analyze and identify its basic biological characteristics. Methods: A 59-year-old Chinese male patient with BMSCC in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology in January 2011 was included in this study, his surgical specimens were primary cultured in vitro by improved tissue block culture method. The BMSCC cell line SCC117 was established after continuous passage and stable growth. The morphological characteristics of the cells were observed by light and electron microscope, and their basic biological characteristics were analyzed by growth curve, chromosome karyotype and xenotransplantation tumorigenicity in nude mice experiment. The expressions of cytokeratin (CK14), tumor-related proteins retinoblastoma tumor suppressor protein (RB), P53, E-cadherin, P21, phosphatase and tensin homolog deleted on chromosome ten (PTEN) were detected by immunohistochemical and human papilloma virus (HPV) were tested by PCR. SCC117 was identified by short tandem repeat (STR) analysis of genomic DNA. Results: SCC117, a human BMSCC cell line, had been continuously subcultured in vitro for more than 150 generations. The cells grew in polygonal mosaic and lost contact inhibition, the typical desmosomes and tensional fibrils were observed by electron microscope, and CK14 was positive by immunohistochemistry. The doubling time was 40.16 h, the chromosome mode of the cell line was concentrated between 67 and 69, hypo-triploid. All 4 nude mice inoculated with SCC117 cells developed tumors, indicating that the SCC117 cell line had the ability of xenogeneic tumorigenesis. The histopathological type of the transplanted tumor in nude mice was consistent with that of the primary tumor tissue, both of which were squamous cell carcinoma. The immunohistochemical results showed that in both human primary tumor and the transplanted tumor tissue in nude mice, RB, P53, and E-cadherin were all positive, P21 was weakly positive, while PTEN was negative. SCC117 was tested negative for the presence of HPV. STR sequence analysis showed that SCC117 cell line originated from primary tumor tissue and was not cross-contaminated by other cell lines. Conclusions: The human BMSCC cell line SCC117 was successfully established in China, which could provide a new experimental model for the study of oral SCC without HPV infection, especially BMSCC.

Preparation of Composite Hydrogels Based on Cysteine-Silver Sol and Methylene Blue as Promising Systems for Anticancer Photodynamic Therapy.

In this study, a novel supramolecular composite, "photogels", was synthesized by mixing of cysteine-silver sol (CSS) and methylene blue (MB). A complex of modern physico-chemical methods of analysis such as viscosimetry, UV spectroscopy, dynamic and electrophoretic light scattering, scanning electron microscopy and energy-dispersive X-ray spectroscopy showed that MB molecules are uniformly localized mainly in the space between fibers of the gel-network formed by CSS particles. Molecules of the dye also bind with the surface of CSS particles by non-covalent interactions. This fact is reflected in the appearance of a synergistic anticancer effect of gels against human squamous cell carcinoma even in the absence of light irradiation. A mild toxic influence of hydrogels was observed in normal keratinocyte cells. Photodynamic exposure significantly increased gel activity, and there remained a synergistic effect. The study of free-radical oxidation in cells has shown that gels are not only capable of generating reactive oxygen species, but also have other targets of action. Flow cytometric analysis allowed us to find out that obtained hydrogels caused cell cycle arrest both without irradiation and with light exposure. The obtained gels are of considerable interest both from the point of view of academics and applied science, for example, in the photodynamic therapy of superficial neoplasms.

Dendritic cells and vascular endothelial growth factor-C in human oral squamous cell carcinoma

ObjectiveDendritic cells (DCs) are antigen-presenting cells that can activate naive T cells and thus play a role in tumor immunity. Vascular endothelial growth factors (VEGFs) produced and secreted by various cancers have been reported to inhibit DC differentiation from progenitor cells. However, the relationship between VEGF-C and DCs in oral squamous cell carcinoma (OSCC) remains unclear. MethodsFormalin-fixed paraffin-embedded samples of 172 OSCCs were studied. Immunohistological staining was performed to determine the density of S100- and CD1a- positive DCs, D2–40-positive lymphatic vessels, and the grade of VEGF-C expression in OSCCs. OSCC cell lines were cultured and examined for VEGF-C secretion using ELISA. ResultsIn comparison to pathological lymph node-negative (PN-) cases, the density of DCs in cancer tissues was significantly lower in PN-positive (PN+) cases, whereas the lymphatic vessel density of cancer tissues was significantly higher in PN+ cases. The density of DCs decreased significantly with increasing VEGF-C expression, indicating a weak inverse relationship. There was a strong positive correlation between VEGF-C expression and lymphatic vessel density. ELISA revealed VEGF-C secretion in various OSCC cell lines, particularly HSC-3, and this increased over time. ConclusionsThese results indicate that VEGF-C expressed by OSCC may increase lymphangiogenesis and create an environment that promotes lymph node metastasis.

Indocyanine green uptake by human tumor and non‑tumor cell lines and tissue.

Indocyanine green (ICG) is a potential promising dye for a better intraoperative tumor border definition and an improved patient outcome by potentially improving tumor border visualization compared with traditional white light guided surgery. Here, the cellular uptake of ICG in human squamous cell carcinoma (SCC026) and immortalized non-cancer skin (HaCaT) cell lines was evaluated to study the tumor-specific cellular uptake of ICG. The spatial distribution of ICG inside tumor tissue was investigated in tissue sections of head and neck squamous cell carcinoma at a microscopic level. ICG uptake and internalization was observed in living cells after 2.5 h and in the nucleus after 24 h. In dead cells, higher and faster uptake was observed. In the tissue sections, higher ICG signal intensity could be detected in connective tissue and surrounding clusters and blood vessels. In conclusion, no distinct ICG uptake by tumor cells was detected in cancer cell lines and tumor tissue. ICG localization in certain regions of tumor tissue appears to be a result of enhanced tissue permeability and retention, but not specific to tumor cells.

Antihypertensive agent losartan promotes tongue squamous cell carcinoma cell proliferation via EGFR/ERK1/2/cyclin D1 signaling axis

ObjectiveTo study the effects of losartan, an angiotensin II receptor blocker, in the SCC4 and SCC25 human tongue squamous cell carcinoma cell lines. MethodsCell proliferation was measured by MTS/PMS activity and trypan blue exclusion assays. The levels of the cell proliferation marker, cyclin D1, were analyzed by western blotting. Apoptosis was assessed by caspase-3 activation and Annexin V-FITC/propidium iodide double staining. Activation of epidermal growth factor receptor (EGFR) and ERK1/2 was validated by western blotting. ResultsModerate concentrations of losartan enhanced the proliferation of SCC4 and SCC25 cells. However, high losartan concentrations induced apoptosis in SCC4 cells. Losartan activated the EGFR/ERK1/2/cyclin D1 signaling axis, which in turn promoted cell proliferation. Afatinib (EGFR inhibitor) and U0126 (ERK1/2 inhibitor) abolished losartan-induced cell proliferation. In contrast, UC2288 (p21 inhibitor) enhanced it. ConclusionsLosartan exhibited dual effects on tongue squamous cell carcinoma cells. Moderate losartan concentrations facilitated cell proliferation, whereas high concentrations induced cytotoxicity in tongue carcinoma cells.

Effect of Agkistrodon acutus venom (AAVC-I) on apoptosis through modulation of the Keap1/Nrf2 pathway in HSC-3 oral squamous cell carcinoma cells.

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor in the oral and maxillofacial regions. Patients with OSCC exhibit a poor response to conventional chemoradiotherapies, which are associated with severe side effects. Therefore, it is essential to identify an effective therapeutic method to treat patients with OSCC. An anti-tumor compound, Agkistrodon acutus venom component I (AAVC-I), purified from Agkistrodon acutus venom, has demonstrated anticancer activity both in vitro and in vivo. However, the mechanism of AAVC-I's anticancer activity in cancer cells has yet to be established. This study aimed to investigate the mechanism of AAVC-I-induced apoptosis in HSC-3 OSCC cells and explore its regulatory effect on oxidative stress. Survival rates of human OSCC cell HSC-3 were detected by Cell Counting Kit-8 (CCK-8). The reactive oxygen species (ROS) level was analyzed by flow cytometry and fluorescence microscopy. The mitochondrial membrane potential was analyzed by cytometry and fluorescent microplate reader. Apoptosis of HSC-3 cells was analyzed using flow cytometry. The oxidative stress level was evaluated using glutathione (GSH), superoxide dismutase (SOD), and malondialdehyde (MDA) kits. In addition, the target proteins were analyzed by western blot. AAVC-I reduced HSC-3 cells' survival rates in a dose-dependent manner with a 50% inhibiting concentration (IC50) of 8.86 µg/mL. It induced apoptosis of HSC-3 cells and the expression of cleaved caspase-3, cleaved caspase-9, and Cyt-c increased significantly, whereas the expression level of Bcl-2 decreased in AAVC-I-treated HSC-3 cells. Thus, AAVC-I caused apoptosis of HSC-3 via the activation of the intrinsic apoptotic pathway. In addition, AAVC-I reduced the mitochondrial membrane potential in HSC-3, enhanced intracellular ROS, and increased intracellular oxidative stress levels in comparison to that of untreated control cells. Furthermore, AAVC-I increased the expression of Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2 (Keap1/Nrf2) levels. These findings demonstrate the inhibitory effects and associated mechanisms of AAVC-I on the HSC-3 OSCC cell line. This insight could be valuable for investigating AAVC-I as a potential therapeutic option for patients with OSCC.