Human Squamous Cell Carcinoma Research Articles

P27 specifically decreases in squamous carcinoma, and mediates NNK-induced transformation of human bronchial epithelial cells.

Lung cancer remains the leading cause of cancer-related deaths, with cigarette smoking being the most critical factor, linked to nearly 90% of lung cancer cases. NNK, a highly carcinogenic nitrosamine found in tobacco, is implicated in the lung cancer-causing effects of cigarette smoke. Although NNK is known to mutate or activate certain oncogenes, its potential interaction with p27 in modulating these carcinogenic effects is currently unexplored. Recent studies have identified specific downregulation of p27 in human squamous cell carcinoma, in contrast to adenocarcinoma. Additionally, exposure to NNK significantly suppresses p27 expression in human bronchial epithelial cells. Subsequent studies indicates that the downregulation of p27 is pivotal in NNK-induced cell transformation. Mechanistic investigations have shown that reduced p27 expression leads to increased level of ITCH, which facilitates the degradation of Jun B protein. This degradation in turn, augments miR-494 expression and its direct regulation of JAK1 mRNA stability and protein expression, ultimately activating STAT3 and driving cell transformation. In summary, our findings reveal that: (1) the downregulation of p27 increases Jun B expression by upregulating Jun B E3 ligase ITCH, which then boosts miR-494 transcription; (2) Elevated miR-494 directly binds to 3'-UTR of JAK1 mRNA, enhancing its stability and protein expression; and (3) The JAK1/STAT3 pathway is a downstream effector of p27, mediating the oncogenic effect of NNK in lung cancer. These findings provide significant insight into understanding the participation of mechanisms underlying p27 inhibition of NNK induced lung squamous cell carcinogenic effect.

Neural landscape is associated with functional outcomes in irradiated patients with oropharyngeal squamous cell carcinoma.

The incidence of human papilloma virus-mediated oropharyngeal squamous cell carcinoma (OPSCC) has increased over the past 40 years, particularly among young individuals with a favorable prognosis; however, current therapy often leads to unfortunate side effects, such as dysphagia. Despite the emphasis on dysphagia in previous studies, there is an important research gap in understanding the correlation between neuronal changes and patient-reported and functional outcomes in patients with OPSCC. To address this issue, we examined pathologic tissue samples from patients with OPSCC using multiplex immunofluorescence staining and machine learning to correlate tumor-associated neuronal changes with prospectively collected patient-reported and functional outcomes. We found that tumor enrichment of adrenergic (TH+) and CGRP+ sensory-afferent nerves correlated with poorer swallowing outcomes. Functional electromyography recordings showed correlations between growing (GAP43+) and immature cholinergic (ChAT+DCX+) nerves and denervation patterns in survivors of OPSCC. A murine model of radiation-induced dysphagia further confirmed that immature cholinergic and CGRP+ nerves were correlated with impaired swallowing. Preclinical interventional studies also supported the independent contributions of CGRP+ and cholinergic (ChAT+) nerves to dysphagia in treated mouse models of OPSCC. Our results suggest that CGRP+ and ChAT+ neuronal signaling play distinct roles in tumor- and radiation-induced dysphagia in OPSCC and offer a comprehensive dataset on the neural landscape of OPSCC. These insights may guide early interventions for swallow preservation and the repurposing of neurology-related drugs, such as CGRP blockers, in clinical oncology and survivorship.

Fucoxanthin Inhibits the Proliferation and Metastasis of Human Pharyngeal Squamous Cell Carcinoma by Regulating the PI3K/Akt/mTOR Signaling Pathway.

Human pharyngeal squamous cell carcinoma (HPSCC) is the most common malignancy in the head and neck region, characterized by high mortality and a propensity for metastasis. Fucoxanthin, a carotenoid isolated from brown algae, exhibits pharmacological properties associated with the suppression of tumor proliferation and metastasis. Nevertheless, its potential to inhibit HPSCC proliferation and metastasis has not been fully elucidated. This study represents the first exploration of the inhibitory effects of fucoxanthin on two human pharyngeal squamous carcinoma cell lines (FaDu and Detroit 562), as well as the mechanisms underlying those effects. The results showed dose-dependent decreases in the proliferation, migration, and invasion of HPSCC cells after fucoxanthin treatment. Further studies indicated that fucoxanthin caused a significant reduction in the expression levels of proteins in the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) pathway, as well as the downstream proteins matrix metalloproteinase (MMP)-2 and MMP-9. Specific activators of PI3K/AKT reversed the effects of fucoxanthin on these proteins, as well as on cell proliferation and metastasis, in FaDu and Detroit 562 cells. Molecular docking assays confirmed that fucoxanthin strongly interacted with PI3K, AKT, mTOR, MMP-2, and MMP-9. Overall, fucoxanthin, a functional food component, is a potential therapeutic agent for HPSCC.

Effect of ethyl pyruvate on human esophageal squamous cell carcinoma transplanted tumors in nude mice.

The objective of this study was to investigate the impact of ethyl pyruvate (EP), an HMGB1 inhibitor, on ESCC cells both in vitro and in vivo. The viability of ESCC cells was assessed using the MTT method to evaluate the correlation between EP and cell viability. A scratch test was used to investigate the relationship between EP and cell migration and invasion. The effects of EP on tumor growth and survival in cancerous nude mice were examined using a tumor formation model. Immunohistochemical staining was performed to evaluate the expression levels of HMGB1, TLR4, and MyD88 in tumor tissues. EP, an anti-HMGB1 inhibitor, inhibited ESCC cell proliferation and metastasis in vitro and in vivo. Furthermore, compared with the control treatment, EP improved the activity, diet, and drinking behaviour of nude mice; inhibited tumour growth; and led to lower protein expression levels of HMGB1, TLR4, and MyD88. EP has the potential to regulate the HMGB1/TLR4-MyD88 signaling pathway, thereby inhibiting the proliferation and metastasis of ESCC, suppressing tumor growth, improving quality of life, and serving as an effective drug for ESCC treatment.

BCAT1 promotes cell proliferation, migration, and invasion via the PI3K-Akt signaling pathway in oral squamous cell carcinoma.

To analyze the expression, biological function of branched chain amino-acid transaminase 1 (BCAT1) in oral squamous cell carcinoma (OSCC). Real-time PCR and immunohistochemistry were used to analyze the expression of BCAT1 protein in OSCC and normal oral tissues. Based on the clinicopathological information of patients, the relationship between the expression of BCAT1 protein and other clinicopathological factors was analyzed. Real-time PCR and western blot assays were used to analyze the expression of BCAT1 gene and protein in normal human oral keratinocytes (HOK) and human OSCC cells, respectively. After BCAT1 overexpression or knockdown, the proliferation, cell cycle, migration, and invasion of human OSCC cells were analyzed by CCK8, flow cytometry, wound healing, and transwell invasion assays, respectively. After adding the BCAT1 inhibitor EGR240 to OSCC cells, the changes in cell proliferation, migration, and invasion ability in OSCC cells were analyzed. Based on the TCGA database, the involved signal pathway in BCAT1-related and BCAT1-binding genes was obtained for Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, verified by western blot assays. After inhibiting PI3K, the effect of BCAT1 on the expression of the downstream phosphorylated protein of the PI3K-Akt signaling pathway was analyzed by western blot assays. The relationship between the expression of BCAT1 and EMT-related protein of OSCC cells was also analyzed. The expression of BCAT1 gene and protein were upregulated in OSCC tissue, which positively correlated with the pathological grade of patients with OSCC. Compared with normal oral keratinocytes, BCAT1 gene and protein were upregulated in OSCC cells. BCAT1 overexpression promoted the proliferation, migration, and invasion of OSCC cells. BCAT1 knockdown or inhibition could reduce the proliferation, migration, and invasion abilities of OSCC cells. The results of bioinformatics analysis and Western bolt showed that BCAT1 could regulate the activation of PI3K-Akt signaling pathway, and promote epithelial-mesenchymal transition (EMT) of OSCC cells. BCAT1 could promote the proliferation, migration, and invasion of OSCC cells via PI3K-Akt signaling pathway, which is a potential therapeutic target for OSCC.

Genomic analysis of BAX and Bcl-2 gene mutations in human papilloma virus-associated squamous cell carcinoma of the cervix

PurposeThe aim of the current study was to molecularly determine Bcl-2 and BAX gene mutations in HPV-associated squamous cell carcinoma of the cervix.MethodsFormalin-fixed, paraffin-embedded tissue blocks, all consisting of squamous cell carcinoma of the cervix, were used for this study. The nucleic acid amplification technique and various steps for DNA sequencing, including DNA extraction and polymerase chain reaction, were used.ResultsMutations were detected in the Bcl-2 gene of patients with squamous cell carcinoma of the cervix in the 10–860 bp region, while BAX gene mutations were detected in the 10–320 bp region. The nucleotide mutations in the Bcl-2 gene were A > G (50%), C > T (33.33%), and G > A > T (16.67%), while the BAX gene mutations were A > (16.67%), T > (16.67%), G > (16.67%), A > C (16.67%), T > G (16.67%), and T > C (16.67%). The mutations in the BAX gene were Indel (50%), Transversion (33.4%), and Transition (16.6%), while only the Transition mutation (100%) was detected in the Bcl-2 gene. The functional mutations in the BAX gene were only missense mutations (100%), but in the Bcl-2 gene, the functional mutations were missense (50%) and silent (50%) mutations.ConclusionOur findings revealed genomic mutations of different types and frequencies in the BAX and Bcl-2 genes in squamous cell carcinoma of the cervix, which should encourage further research to better understand these mutations and exploit them for clinical use.

Human papillomavirus-associated head and neck squamous cell carcinoma cells lose viability during triggered myocyte lineage differentiation

Head and neck squamous cell carcinoma (HNSCC) is a highly malignant disease, and death rates have remained at approximately 50% for decades. New tumor-targeting strategies are desperately needed, and a previous report indicated the triggered differentiation of HPV-negative HNSCC cells to confer therapeutic benefits. Using patient-derived tumor cells, we created a similar HNSCC differentiation model of HPV+ tumor cells from two patients. We observed a loss of malignant characteristics in differentiating cell culture conditions, including irregularly enlarged cell morphology, cell cycle arrest with downregulation of Ki67, and reduced cell viability. RNA-Seq showed myocyte-like differentiation with upregulation of markers of myofibril assembly. Immunofluorescence staining of differentiated and undifferentiated primary HPV+ HNSCC cells confirmed an upregulation of these markers and the formation of parallel actin fibers reminiscent of myoblast-lineage cells. Moreover, immunofluorescence of HPV+ tumor tissue revealed areas of cells co-expressing the identified markers of myofibril assembly, HPV surrogate marker p16, and stress-associated basal keratinocyte marker KRT17, indicating that the observed myocyte-like in vitro differentiation occurs in human tissue. We are the first to report that carcinoma cells can undergo a triggered myocyte-like differentiation, and our study suggests that the targeted differentiation of HPV+ HNSCCs might be therapeutically valuable.

Biopsy-verified vulvar lichen sclerosus and the risk of non-vulvar cancer: A nationwide cohort study.

Vulvar lichen sclerosus (VLS) is a chronic inflammatory mucocutaneous disease known to be associated with human papillomavirus-independent vulvar squamous cell carcinoma. Evidence on the association with other types of cancer, however, is sparce. We conducted a large nationwide cohort study examining the incidence of non-vulvar cancers among women with biopsy-verified VLS compared with the general female population. By using the nationwide Pathology Registry, we identified all women in Denmark with a biopsy-verified VLS diagnosis during 1978-2019 (n = 16,921). The cohort was followed up in the Danish Cancer Registry until 2022 for a subsequent non-vulvar cancer diagnosis. Standardized incidence ratios (SIRs) were computed with 95% confidence intervals (CIs) as relative risk estimates of all specific non-vulvar cancer sites. Compared with general female population rates, women with biopsy-verified VLS had decreased rates of several non-vulvar cancers, including HPV-related cancers (combined estimate: SIR = 0.5; 95% CI: 0.3-0.7), and lung (SIR = 0.6; 95% CI: 0.5-0.7), liver (SIR = 0.5; 95% CI: 0.2-0.9), and thyroid cancer (SIR = 0.5; 95% CI: 0.3-0.9). The decreased SIRs tended to sustain throughout the follow-up period following the VLS diagnosis. This large nationwide cohort study shows that women with biopsy-verified VLS may have a long-term reduced risk of developing HPV-related (cervical, vaginal, oropharyngeal, and anal) and smoking-associated cancers (lung, liver, and cervical) as well as thyroid cancer. Future studies focusing on the mechanisms behind the decreased cancer risk are needed.

A Food Odorant, α-Ionone, Inhibits Skin Cancer Tumorigenesis by Activation of OR10A6.

This study aims to investigate the anticancer properties of α-ionone in squamous cell carcinoma (SCC). The expression of OR10A6 together with olfactory receptor signaling components is demonstrated in A431 human SCC cells via RT-PCR and qRT-PCR analysis. OR10A6 activation in A431 cells using the ligand α-ionone inhibits proliferation and migration but induces apoptosis which is confirmed by proliferation assay, colony formation, and western blotting. The mechanism involves the core proteins of the Hippo pathway, where the phosphorylation of large tumor suppressor kinase (LATS), yes-associated protein (YAP), and transcriptional coactivator with PDZ-binding motif (TAZ) is confirmed by western blotting. However, the anticancer effects of α-ionone are abrogated in A431 cells with OR10A6 gene knockdown. In A431 xenograft mouse model, the injection of α-ionone suppresses tumor growth, induces apoptosis, and increases phosphorylation of the LATS-YAP-TAZ signaling axis in the Hippo pathway. None of these effects are observed in xenografted tumors with OR10A6 gene knockdown. These findings collectively demonstrate that activation of ectopic OR OR10A6 by α-ionone in SCC cells stimulates the Hippo pathway and suppresses tumorigenesis both in vitro and in vivo, suggesting a novel therapeutic candidate for the treatment of SCC.

Silencing CK19 regulates ferroptosis by affecting the expression of GPX4 and ACSL4 in oral squamous cell carcinoma in vivo and in vitro

To analyze the mechanism of how interfering with the cytokeratin 19 (CK19) pathway via the ferroptosis pathway affects tumor biological behaviors in the process of oral squamous cell carcinoma (OSCC) development. TCGA was used to analyze the expression of CK19 in pan-cancer and head and neck squamous cell carcinoma (HNSC) and to explore the ferroptosis-related genes related to HNSC. The effect of silencing CK19 on the migration ability of HSC-4 cells was verified by wound healing and migration assay. HSC-4 cells with silencing of CK19 and tumor-bearing nude mouse model were constructed. RT-qPCR, immunofluorescence and western blot were used to analyze the expression of ferroptosis-related genes. CK19 is highly expressed in human OSCC and nude mice. The migration ability of cells in the CK19-silenced group was lower than that of the control group. In vivo and in vitro, CK19 was negatively correlated with the expression of ACSL4 and positively correlated with the expression of GPX4. Compared with the control group, GPX4 expression was down-regulated and ACSL4 expression was up-regulated in the CK19-silenced group. Silencing CK19 also increased intracellular Fe2+ content and MDA content. Silencing CK19 can affect the expression of GPX4 and ACSL4 to regulate ferroptosis and at the same time increase the content of MDA, Fe2+ and ROS levels, thereby activating the regulation of ferroptosis pathway in the development of OSCC.

Diagnostic Impact of P53,P16, Retinoblastoma, and Bcl-2 Proteins in Human Papillomavirus-Associated Squamous Cell Carcinoma Cervical Lesions

Diagnostic Impact of P53,P16, Retinoblastoma, and Bcl-2 Proteins in Human Papillomavirus-Associated Squamous Cell Carcinoma Cervical Lesions

Immunological Signatures for Early Detection of Human Head and Neck Squamous Cell Carcinoma through RNA Transcriptome Analysis of Blood Platelets.

Although there has been a reduction in head and neck squamous cell carcinoma occurrence, it continues to be a serious global health concern. The lack of precise early diagnostic biomarkers and postponed diagnosis in the later stages are notable constraints that contribute to poor survival rates and emphasize the need for innovative diagnostic methods. In this study, we employed machine learning alongside weighted gene co-expression network analysis (WGCNA) and network biology to investigate the gene expression patterns of blood platelets, identifying transcriptomic markers for HNSCC diagnosis. Our comprehensive examination of publicly available gene expression datasets revealed nine genes with significantly elevated expression in samples from individuals diagnosed with HNSCC. These potential diagnostic markers were further assessed using TCGA and GTEx datasets, demonstrating high accuracy in distinguishing between HNSCC and non-cancerous samples. The findings indicate that these gene signatures could revolutionize early HNSCC identification. Additionally, the study highlights the significance of tumor-educated platelets (TEPs), which carry RNA signatures indicative of tumor-derived material, offering a non-invasive source for early-detection biomarkers. Despite using platelet and tumor samples from different individuals, our results suggest that TEPs reflect the transcriptomic and epigenetic landscape of tumors. Future research should aim to directly correlate tumor and platelet samples from the same patients to further elucidate this relationship. This study underscores the potential of these biomarkers in transforming early diagnosis and personalized treatment strategies for HNSCC, advocating for further research to validate their predictive and therapeutic potential.

Mutant Nrf2E79Q enhances the promotion and progression of a subset of oncogenic Ras keratinocytes and skin tumors

Squamous cell carcinomas (SCCs), including lung, head & neck, bladder, and skin SCCs often display constitutive activation of the KEAP1-NRF2 pathway. Constitutive activation is achieved through multiple mechanisms, including activating mutations in NFE2L2 (NRF2). To determine the functional consequences of Nrf2 activation on skin SCC development, we assessed the effects of mutant Nrf2E79Q expression, one of the most common activating mutations in human SCCs, on tumor promotion and progression in the mouse skin multistage carcinogenesis model using a DMBA-initiation/TPA-promotion protocol where the Hras A->T mutation (Q61L) is the canonical driver mutation. Nrf2E79Q expression was temporally and conditionally activated in the epidermis at two stages of tumor development: 1) after DMBA initiation in the epidermis but before cutaneous tumor development and 2) in pre-existing DMBA-initiated/TPA-promoted squamous papillomas. Expression of Nrf2E79Q in the epidermis after DMBA initiation but before tumor occurrence inhibited the development/promotion of 70% of squamous papillomas. However, the remaining papillomas often displayed non-canonical Hras and Kras mutations and enhanced progression to SCCs compared to control mice expressing wildtype Nrf2. Nrf2E79Q expression in pre-existing tumors caused rapid regression of 60% of papillomas. The remaining papillomas displayed the expected canonical Hras A->T mutation (Q61L) and enhanced progression to SCCs. These results demonstrate that mutant Nrf2E79Q enhances the promotion and progression of a subset of skin tumors and alters the frequency and diversity of oncogenic Ras mutations when expressed early after initiation.

Procaine induces cell cycle arrest, apoptosis and autophagy through the inhibition of the PI3K/AKT and ERK pathways in human tongue squamous cell carcinoma.

Procaine (PCA), a local anesthetic commonly used in stomatology, exhibits antitumor activity in some human malignancies. However, the precise mechanism underlying PCA activity remains unknown, and its antitumor effect in human tongue squamous carcinoma cells has not been reported. Flow cytometry and western blotting were used to assess the effects of PCA on mitochondrial membrane potential (ΔΨm), intracellular reactive oxygen species (ROS) production, cell cycle and apoptosis. The results suggested that PCA inhibits CAL27 and SCC-15 cell proliferation, and clone formation in a dose-dependent manner. CAL27 cells were more sensitive to PCA than SCC-15 cells. PCA also significantly inhibited cell migration, induced mitochondrial damage, reduced ΔΨm and increased intracellular ROS production. PCA causes G2/M cycle arrest and induces apoptosis. The possible mechanism for the inhibition of human tongue squamous carcinoma cell proliferation is through the regulation of ERK phosphorylation and PI3K/AKT-mediated signaling pathways. The results further suggested that autophagy occurs during PCA-induced apoptosis in CAL27 cells, and the addition of the autophagy inhibitor hydroxychloroquine sulfate further enhanced the sensitivity of PCA to inhibit cell proliferation, indicating that autophagy plays an important role in protecting cancer cells from apoptosis. PCA shows potential as an anticancer drug and its combination with autophagy inhibitors enhances its sensitivity.

The results of immunotherapy in patients with recurrent and metastatic human papilloma virus positive head and neck squamous cell carcinoma

The results of immunotherapy in patients with recurrent and metastatic human papilloma virus positive head and neck squamous cell carcinoma

Effects of α‑solanine on human head and neck squamous cell carcinoma cells and human umbilical vein endothelial cells in vitro.

α-solanine is a glycoalkaloid that is commonly found in nightshades (Solanum) and has a toxic effect on the human organism. Among other things, it is already known to inhibit tumor cell proliferation and induce apoptosis in tumor cell lines. Due to its potential as a tumor therapeutic, the current study investigated the effect of α-solanine on head and neck squamous cell carcinoma (HNSCC). In addition, genotoxic and antiangiogenic effects on human umbilical vein endothelial cells (HUVECs) were evaluated at subtoxic α-solanine concentrations. Cytotoxicity and apoptosis rates were measured in two human HNSCC cell lines (FaDu pharynx carcinoma cells and CAL-33 tongue carcinoma cells), as well as in HUVECs. MTT and Annexin V analyses were performed 24 h after α-solanine treatment at increasing doses up to 30 µM to determine cytotoxic concentrations. Furthermore, genotoxicity at subtoxic concentrations of 1, 2, 4 and 6 µM in HUVECs was analyzed using single-cell gel electrophoresis (comet assay). The antiangiogenic effect on HUVECs was evaluated in the capillary tube formation assay. The MTT assay indicated an induction of concentration-dependent viability loss in FaDu and CAL-33 cancer cell lines, whereas the Annexin V test revealed α-solanine-induced cell death predominantly independent from apoptosis. In HUVECs, the cytotoxic effect occurred at lower concentrations. No genotoxicity or inhibition of angiogenesis were detected at subtoxic doses in HUVECs. In summary, α-solanine had a cytotoxic effect on both malignant and non-malignant cells, but this was only observed at higher concentrations in malignant cells. In contrast to existing data in the literature, tumor cell apoptosis was less evident than necrosis. The lack of genotoxicity and antiangiogenic effects in the subtoxic range in benign cells are promising, as this is favorable for potential therapeutic applications. In conclusion, however, the cytotoxicity in non-malignant cells remains a severe hindrance for the application of α-solanine as a therapeutic tumor agent in humans.

Enhancement of Tumor Antigen-specific T-cell Responses by Immune Checkpoint Blockade in Human Papillomavirus-related Head and Neck Squamous Cell Carcinoma.

Human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) is clinically and immunologically distinct from HPV-negative HNSCC. Herein, we investigated the presence of tumor antigens HPV E6/E7 and wild-type p53-specific T-cell responses, and the impact of immune checkpoint blockade in patients with HPV-positive HNSCC. Peripheral blood mononuclear cells (PBMCs) from patients with HPV-positive HNSCC were stimulated with HPV E6/E7 or wild-type p53-derived peptide mixture and evaluated using the interferon-γ enzyme-linked immunosorbent spot assay. Flow cytometry was performed to analyze the proportion of T-cell subsets and T cells expressing immune checkpoint molecules. HPV E6/E7-specific T cells were detected in 22 (95.7%) of 23 patients, whereas wild-type p53-specific T cells were detected in 3 (15.0%) of 20 patients. Seven (43.8%) of 16 patients exhibited wild-type p53-specific T-cell responses, as determined using whole proteins instead of peptides. Immune checkpoint blockade enhanced wild-type p53-specific T-cell responses in 9 (45.0%) of 20 patients. Flow cytometric analysis of PBMCs revealed that responders exhibiting enhanced wild-type p53-specific T-cell responses following immune checkpoint blockade had a significantly higher proportion of Ki-67+CD4+ T cells, Ki-67+CD8+ T cells, regulatory T cells, PD-1+CD4+ T cells, and TIM-3+CD4+ T cells than non-responders. Our findings indicate that tumor antigen-specific T cells are present in the peripheral blood of patients with HPV-positive HNSCC. Blockade of checkpoint pathways can enhance T-cell responses in certain patients, probably via activated T cells, Tregs, and/or exhausted CD4+ T cells.

Interaction of the tumor suppressor SMAD4 and WNT signaling in progression to oral squamous cell carcinoma.

SMAD4 is a tumor suppressor mutated or silenced in multiple cancers, including oral cavity squamous cell carcinoma (OSCC). Human clinical samples and cell lines, mouse models and organoid culture were used to investigate the role that SMAD4 plays in progression from benign disease to invasive OSCC. Human OSCC lost detectable SMAD4 protein within tumor epithelium in 24% of cases, and this loss correlated with worse progression-free survival independent of other major clinical and pathological features. A mouse model engineered for KrasG12D expression in the adult oral epithelium induced benign papillomas, however the combination of KrasG12D with loss of epithelial Smad4 expression resulted in rapid development of invasive carcinoma with features of human OSCC. Examination of regulatory pathways in 3D organoid cultures of SMAD4+ and SMAD4- mouse tumors with Kras mutation found that either loss of SMAD4 or inhibition of TGFβ signaling upregulated the WNT pathway and altered the extracellular matrix. The gene signature of the mouse tumor organoids lacking SMAD4 was highly similar to the gene signature of human head and neck squamous cell carcinoma. In summary, this work has uncovered novel mechanisms by which SMAD4 acts as a tumor suppressor in OSCC. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Cytotoxic effects of the cigarette smoke extract of heated tobacco products on human oral squamous cell carcinoma: the role of reactive oxygen species and CaMKK2

BackgroundThe increasing prevalence of heated tobacco products (HTPs) has heightened concerns regarding their potential health risks. Previous studies have demonstrated the toxicity of cigarette smoke extract (CSE) from traditional tobacco’s mainstream smoke, even after the removal of nicotine and tar. Our study aimed to investigate the cytotoxicity of CSE derived from HTPs and traditional tobacco, with a particular focus on the role of reactive oxygen species (ROS) and intracellular Ca2+.MethodsA human oral squamous cell carcinoma (OSCC) cell line, HSC-3 was utilized. To prepare CSE, aerosols from HTPs (IQOS) and traditional tobacco products (1R6F reference cigarette) were collected into cell culture media. A cell viability assay, apoptosis assay, western blotting, and Fluo-4 assay were conducted. Changes in ROS levels were measured using electron spin resonance spectroscopy and the high-sensitivity 2ʹ,7ʹ-dichlorofluorescein diacetate assay. We performed a knockdown of calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) by shRNA lentivirus in OSCC cells.ResultsCSE from both HTPs and traditional tobacco exhibited cytotoxic effects in OSCC cells. Exposure to CSE from both sources led to an increase in intracellular Ca2+ concentration and induced p38 phosphorylation. Additionally, these extracts prompted cell apoptosis and heightened ROS levels. N-acetylcysteine (NAC) mitigated the cytotoxic effects and p38 phosphorylation. Furthermore, the knockdown of CaMKK2 in HSC-3 cells reduced cytotoxicity, ROS production, and p38 phosphorylation in response to CSE.ConclusionOur findings suggest that the CSE from both HTPs and traditional tobacco induce cytotoxicity. This toxicity is mediated by ROS, which are regulated through Ca2+ signaling and CaMKK2 pathways.Graphical

Identification of Regulatory RNA-Binding Proteins Associated with Immune Infiltration in Laryngeal Squamous Cell Carcinoma.

We analyzed bulk RNA sequencing and single-cell RNA sequencing (scRNA-seq) data to identify alternative splicing (AS) events and regulatory RNA-binding proteins (RBPs) associated with immune infiltration in human laryngeal squamous cell carcinoma (LSCC). Whole-transcriptome sequencing data of 20 human laryngeal cancer and paracancerous tissues were downloaded from the Gene Expression Omnibus public database, using newly published splicing-site usage variation analysis software to obtain highly conserved regulated AS (RAS) events, and scientific reverse convolution algorithm analysis was used to identify significantly different immune cells and perform a correlation analysis between the two. The software package edgeR was used to identify differentially expressed RBPs and the immune infiltration-related LSCC-RAS they may regulate. Finally, we present the expression profiles and survival curves of 117 human laryngeal cancer samples from The Cancer Genome Atlas dataset for the identified RBPs and LSCC-RAS. We also downloaded the gene set enrichment 150321 scRNA-seq data for two human LSCC tissue samples. The RBP expression pattern and the expression of prophase RBP genes were analyzed in different LSCC cell populations. RNA-binding motif protein 47 (RBM47) and filamin A, as well as the RBP-RAS events that were screened in both the fibulin 2 and fibronectin 1 genes, were all significantly associated with the prognosis, and the RBM47 gene was upregulated in myeloid cells. Because the prognosis was significantly associated with two RBP regulators and two LSCC-RAS events, they may be critical regulators of immune cell survival during laryngeal cancer progression, and RBM47 may regulate macrophage-associated AS and affect immunity.