Oral Squamous Cell Carcinoma Patients Research Articles

Survival analysis of Sudanese oral squamous cell carcinoma patients with field of cancerization.

The late presentation and diagnosis of OSCC account for the large number of patients with the advanced form of the disease. In Sudan, cases with delayed presentation, particularly those with risk factors such as Toombak dipping and alcohol consumption, frequently present with extensive lesions and a wide area of Field cancerization which characterized by the presence of genetic and epigenetic changes in histologically normal-appearing tissues, and have increased risk for recurrent and second primary tumors. This necessitates more aggressive treatment and is usually associated with poorer outcomes. The present study aims to investigate the survival of oral squamous cell carcinoma patients with a wide field of cancerization. This prospective longitudinal study includes ninety-three oral cancer patients with extensive fields of cancerization who underwent surgical treatment at Khartoum Teaching Dental Hospital (KTDH) conducted from 2019 to 2023. These patients were regularly assessed for clinical changes such as recurrence, the development of second primary tumours, and overall survival over a period of one year. Out of the 93 patients, 57 (61.3%) were males, and 36 (38.7%) were females. The majority of the patients (82%) had stage IV tumours, and 62.3% had nodal metastasis. Twenty-eight (30%) patients developed recurrences, and 14 (15%) developed second primary tumours. The overall one-year survival rate was 89%, and all deceased patients passed away within 12 months. The survival rate for patients with different types of recurrences varied, with patients who had regional, local, and locoregional recurrences having survival rates of 87%, 74%, and 72%, respectively. Patients who did not experience a recurrence had a one-year survival rate of 92%. Patients who developed second primary tumours had an 86% survival rate. The survival rates for OSCC patients at stages III, IVa, and IVb were 90%, 90%, and 71%, respectively. In this study, 62% of patients had nodal metastasis, 30% developed recurrence, and 15% developed second primary tumours. The overall one-year survival rate was 89%, although the development of recurrences and second primary tumours had a negative impact on the survival rate.

Expression of Toll-like receptors in oral squamous cell carcinoma.

Almost 380,000 new cases of oral cancer were reported worldwide in 2020. Oral squamous cell carcinoma (OSCC) accounts for 90% of all types of oral cancers. Emerging studies have shown association of Toll-like receptors (TLRs) in carcinogenesis. The present study aimed to investigate the expression levels and tissue localization of TRL1 to TRL10 and NF-κB between OSCC and healthy oral mucosa, as well as effect of Candida colonization in TRL expression in OSCC. Full thickness biopsies and microbial samples from 30 newly diagnosed primary OSCC patients and 26 health controls were collected. The expression of TLR1 to TLR10 and NF-κB was analyzed by immunohistochemistry. Microbial samples were collected from oral mucosa to detect Candida. OSCC epithelium showed lower staining intensity of TRL1, TRL2 TRL5, and TRL8 as compared to healthy controls. Similarly, staining intensity of TRL3, TRL4, TRL7, and TRL8 were significantly decreased in basement membrane (BM) zone. Likewise, OSCC endothelium showed lower staining intensity of TLR4, TLR7 and TLR8. Expression of NF-κB was significantly stronger in normal healthy tissue compared to OSCC sample. Positive correlation was found between the expression of NF-κB, TRL9 and TRL10 in basal layer of the infiltrative zone OSCC samples (P = 0.04 and P = 0.002, respectively). Significant increase in TRL4 was seen in BM zone of sample colonized with Candida (P = 0.01). According to the limited number of samples, our data indicates downregulation of TLRs and NF-κB in OSCC, and upregulation of TLR4 expression with presence of Candida.

Increased V-ATPase activity can lead to chemo-resistance in oral squamous cell carcinoma via autophagy induction: new insights.

Oral squamous cell carcinoma (OSCC) is a cancer type with a high rate of recurrence and a poor prognosis. Tumor chemo-resistance remains an issue for OSCC patients despite the availability of multimodal therapy options, which causes an increase in tumor invasiveness. Vacuolar ATPase (V-ATPase), appears to be one of the most significant molecules implicated in MDR in tumors like OSCC. It is primarily responsible for controlling the acidity in the solid tumors' microenvironment, which interferes with the absorption of chemotherapeutic medications. However, the exact cellular and molecular mechanisms V-ATPase plays in OSCC chemo-resistance have not been understood. Uncovering these mechanisms can contribute to combating OSCC chemo-resistance and poor prognosis. Hence, in this review, we suggest that one of these underlying mechanisms is autophagy induced by V-ATPase which can potentially contribute to OSCC chemo-resistance. Finally, specialized autophagy and V-ATPase inhibitors may be beneficial as an approach to reduce drug resistance to anticancer therapies in addition to serving as coadjuvants in antitumor treatments. Also, V-ATPase could be a prognostic factor for OSCC patients. However, in the future, more investigations are required to demonstrate these suggestions and hypotheses.

EFFECT OF BETEL NUTS AND TOBACCO DERIVATIVES ON ANTIOXIDANTS AND MICRONUTRIENTS IN ORAL SUBMUCOUS FIBROSIS AND ORAL CANCER PATIENTS IN GUJARAT POPULATION

Objective: In our previous study, we have find the significance of biochemical markers between precancerous and cancerous subject with normal healthy individuals in Gujarat population, taking into consideration the severity of biochemical markers in cancerous condition. We felt that other than comparison, effect of betel nuts and tobacco derivatives on antioxidants and micronutrients has required further evaluation to develop a better understanding. The objective of the present study is to measure the interdependence of antioxidants and micronutrients in oral submucous fibrosis and oral cancer patients and find its significance. Method: In this study, a total of 150 patients in which 50 diagnosed PMD patients and 50 diagnosed oral cancer patients with 50 healthy non-tobacco consuming were selected as a control group. Five to seven milliliters of venous blood was collected under aseptic precautions with patients consent. All the parameters were analyzed by standard methods using fully auto-analyzed with a ready-to-use kit. Result: This research was conducted on 150 patients, out of which 50 diagnosed potential malignant disorder patients and 50 oral squamous cell carcinoma patients matched with 50 healthy control individuals. Average age of patients with PMD and OSCC was 55.6±9.74-and that of control group was 35.83±8.90 years. Student t-test showed that there was a significant difference between the two groups with regard to age. Of the 100 patients with PMD, 72 (72% of total) were men and 28 (28% of total) were women. Among the individuals in the control group (n=50), 35 persons (70% of total) were men and 15 (30% of total) were women. Chi-square test showed that there was no significant difference between the two groups in terms of sex (p=0.891). The copper levels of PMD and OSCC, respectively, were 153.57±7.68 and 164.43±15.75. The value was statistically compared with OSCC which had significantly higher levels than healthy control (102.53±22.1). The iron levels of PMD and OSCC, respectively, were 77.62±15.27 and 50.04±19.97. The value was statistically compared with OSCC which had significantly lower levels than (138.4±13.2) healthy control. The Vitamin C levels of PMD and OSCC, respectively, are 0.55±0.10 and 0.44±0.9. The value was statistically compared to the OSCC which had significantly lower than 1.09±0.17 control. The Vitamin E levels of PMD and OSCC, respectively, 1.18±0.16 and 0.8±0.12 values were statistically compared the OSCC which had significantly lower levels than (1.39±3.64) healthy control. Conclusion: In our finding, Vitamin C showed positive correlation with serum iron and serum copper with malignant disorders. Trace elements and antioxidants exhibited interdependence in both physiologic and pathologic states such as oral cancer.

Abstract LB379: HLA-DQB1*05:02: An independent genetic marker for oral cavity squamous cell carcinoma susceptibility

Abstract Environmental exposure to carcinogens causes mucosal damage in the upper aerodigestive tract, which can lead to cancers. The genetic basis of head and neck cancer is controversial. To identify susceptibility genes in head and neck cancers, we enrolled patients with early-onset disease in Taiwan. This case-control study included 54 young male patients with oral squamous cell carcinoma (OSCC) who were treated between March 1996 and December 2016, as well as 2,400 healthy controls. A single-nucleotide polymorphism (SNP) array was used to determine genetic loci that increase susceptibility to OSCC. Sequencing-based typing (TBG Biotechnology Corp., Taipei, Taiwan) was used to determine the HLA-DQB1 genotype in another cohort of 147 OSCC patients. We analyzed the allele frequencies of 664,994 autosomal SNPs in the 54 OSCC cases. In a genome-wide association analysis, four SNPs within loci on chromosomes 6, 7, 9, and 12 were significantly different between OSCC patients and controls (corrected P < 1.0 × 10−6). HLA-DQB1 was closest to rs28451423 on chromosome 6. HLA-DQB1*05:02 in OSCC (18.5%) was significantly different from normal population (7.0%) (P = 0.009). The influence of disease onset was independently significant after adjusting cigarette smoking, alcohol drinking and areca-quid chewing (P = 0.015, OR: 3.922, 95% confidence interval: 1.311 - 11.734). Furthermore, HLA-DQB1*05:02 was associated with early-onset OSCC (P = 0.004). HLA-DQB1*05:02 is associated with OSCC independent of environmental exposures. HLA-DQB1*05:02 is also related with early onset of OSCC. It provides evidence of a genetic basis for OSCC. Citation Format: Shiang-Fu Huang, Huei-Tzu Chien, Chi-Kuan Young, Yun-Shien Lee, Chun-Ta Liao, Kai-Lun Cho, Ching-Han Chen. HLA-DQB1*05:02: An independent genetic marker for oral cavity squamous cell carcinoma susceptibility [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB379.

Abstract LB329: Interleukin6 as a Potential Prognostic Marker and Therapeutic Target in Oral Squamous Cell Carcinoma

Abstract This study investigates the role of interleukin (IL)-6 in oral squamous cell carcinoma (OSCC), evaluating its potential as a prognostic marker and therapeutic target. This study involved 95 untreated OSCC patients, with pre-surgical serum IL-6 levels measured by Electro chemiluminescence immunoassay (ECLIA). Patients were categorized into high (78 patients) and low (17 patients) IL-6 groups based on a cutoff value of 8 pg/mL.A strong correlation was observed between higher IL-6 levels and lower overall survival (P<0.0001) and disease-free survival (P=0.0283). Serum IL-6 levels also showed a strong positive correlation with certain blood test markers such as neutrophil and lymphocyte fractions and C-reactive protein (CRP), and a negative correlation with albumin levels. These findings suggest a link between systemic inflammation, malnutrition, and the Inflammation-based prognostic score (IBPS).Further analysis through microarray assessed the gene expression in primary tumor tissues, revealing 513 genes with more than a two-fold change in the high IL-6 group compared to controls. Gene Ontology analysis indicated increased metabolic activity in the high IL-6 group and suppressed inflammation and immune-related molecules in the low IL-6 group.Immunohistochemical staining for IL-6 in tumor tissues showed its presence mainly in the stroma, particularly in cancer-associated fibroblasts (CAFs) identified by vimentin and α-SMA positivity. Both OSCC cell lines and CAFs established from OSCC tissues demonstrated high IL-6 secretion, especially in cell lines derived from lymph node metastases. Furthermore, cell lines from primary, lymph node, and lung metastases exhibited high IL-6 secretion, with HRAS mutations also identified. Knockdown of HRAS using siRNA reduced IL-6 secretion.Finally, in vivo experiments using an anti-IL-6 receptor antibody showed that blocking IL-6 signaling reduced the proliferation of OSCC cell lines.The study concludes that IL-6 is a useful prognostic and therapeutic target in OSCC. The wide applicability of IL-6 testing and the clinical use of anti-human IL-6R antibody drugs, combined with aggressive nutritional intervention, suggest a potential paradigm shift in OSCC treatment. Citation Format: Hiroyuki Goda, Tomoko Adachi, Koh-ichi Nakashiro, Nobuyuki Kuribayashi, Daisuke Uchida. Interleukin6 as a Potential Prognostic Marker and Therapeutic Target in Oral Squamous Cell Carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB329.

Abstract LB290: Whole exome analysis of oral squamous cell carcinoma in local patients at tertiary care hospitals in Peshawar, Pakistan

Abstract The Precision Medicine Lab (PML) has been mandated by the Federal Government in 2018 to pilot precision medicine in Pakistan using genomics in oral cancer. With the Indian subcontinent as its capital, oral squamous cell carcinoma (OSCC), also dubbed as ‘poor man’s cancer', constitutes 90% of all head and neck cancers and is the highest incidence cancer found in Pakistani males. Backed by a bio-repository of clinical samples as well as a catalogue of primary cell clines, PML takes a multi-omic approach to discovering new, actionable biomarkers for diagnostic, prognostic and therapeutic applications. With all necessary ethical approvals obtained from IRBs at each site along with written informed consent from each patient, treatment-naive biopsy-confirmed patients of OSCC were recruited in two main tertiary care hospitals in Peshawar, Pakistan. Our cohort was predominantly older with 37.84% between 41-60 years, late-stage with 78.46% presenting in stage IV and self-reportedly non-alcohol consuming (96.9%). About 44.6% reported the use of smokeless tobacco while 30.8% reported the use of both smoked and smokeless tobacco. Majority of the tumours were located in the buccal mucosa (29.2%), alveolar region (27.7%) or the vestibular region (24.6%). We obtained blood and tumour samples for matched-pair whole exome sequencing, transcriptomics and metabolomics as well as generation of primary cell lines. We also obtained saliva samples for oral microbiome analysis. Combined with the patient’s clinical history and digital histopathology images, this helps us create a multi-omic stack that we intend to make available for integrated machine learning experiments. With our whole exome sequencing now complete, we undertook a preliminary analysis for this late breaking abstract. Raw reads were aligned to the GRCh38.p14 reference genome and were called for germline and somatic SNPs and INDELs using GATK (v4.5). Mutational analysis was conducted using the maftools (v2.18.0) package in R (v4.3) by comparing against the COSMIC SBS Signature database (v3.2). We report MUC12 (100%), ZNF717 (100%), FOLR3 (86%), EPPK1 (79%) and SPATA31A6 (79%) as the top mutated genes in the subset of exomes analysed thus far for our cohort. Genes reported previously including TP53, NOTCH1 and PIK3CA appear to rank lower on the list. In terms of cancer-related pathways, RTK-RAS (92.8%), Hippo (92.8%) and Notch (78.5%) were affected in most of the samples. To our knowledge, we describe for the first time the mutational landscape in an OSCC cohort from the Pakistani population. We also go beyond whole exomes as our multi-omic approach offers the potential on machine learning experiments to identify putative mutational signatures and biomarkers for OSCC that can be of diagnostic, prognostic and therapeutic value to the local (Pakistani and Afghan) patient population. With the availability of primary cell lines for every patient, we also intend to undertake experimental validation of high priority targets using primary patient-derived cell lines in the lab. Citation Format: Hina Zamir, Khudeja Salim, Madina Sherdil, Aqsa Hussain, Yusra Ilyas, Arsalan Riaz, Momal Agha, Zainab Jahan, Khadim Shah, Yasir Rehman Khattak, Fahim Uddin, Zahid Qayyum Shah, Zubair Durrani, Muhammad Mushtaq Khattak, Johar Ali, Faisal F. Khan. Whole exome analysis of oral squamous cell carcinoma in local patients at tertiary care hospitals in Peshawar, Pakistan [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB290.

The metabolic reprogramming of γ-aminobutyrate in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common head and neck malignancy. The oncometabolites have been studied in OSCC, but the mechanism of metabolic reprogramming remains unclear. To identify the potential metabolic markers to distinguish malignant oral squamous cell carcinoma (OSCC) tissue from adjacent healthy tissue and study the mechanism of metabolic reprogramming in OSCC. We compared the metabolites between cancerous and paracancerous tissues of OSCC patients by 1HNMR analysis. We established OSCC derived cell lines and analyzed their difference of RNA expression by RNA sequencing. We investigated the metabolism of γ-aminobutyrate in OSCC derived cells by real time PCR and western blotting. Our data revealed that much more γ-aminobutyrate was produced in cancerous tissues of OSCC patients. The investigation based on OSCC derived cells showed that the increase of γ-aminobutyrate was promoted by the synthesis of glutamate beyond the mitochondria. In OSCC cancerous tissue derived cells, the glutamate was catalyzed to glutamine by glutamine synthetase (GLUL), and then the generated glutamine was metabolized to glutamate by glutaminase (GLS). Finally, the glutamate produced by glutamate-glutamine-glutamate cycle was converted to γ-aminobutyrate by glutamate decarboxylase 2 (GAD2). Our study is not only benefit for understanding the pathological mechanisms of OSCC, but also has application prospects for the diagnosis of OSCC.

Increased SEC14L2 expression is associated with clinicopathological features and worse prognosis in oral squamous cell carcinoma.

Abnormal expression of SEC14L2 has been implicated in many human cancers. However, the role of SEC14L2 in oral squamous cell carcinoma (OSCC) remains unclear. Therefore, this study aimed to evaluate the expression and prognostic roles of SEC14L2 in OSCC. OSCC tumors and adjacent non-tumors were collected from OSCC patients and used for SEC14L2 mRNA expression by quantitative reverse transcription PCR (RT-qPCR). Additionally, the expression of SEC14L2 was further analyzed using The Cancer Genome Atlas-Head Neck Squamous Cell Carcinoma (TCGA-HNSCC) dataset to identify its relationship with HNSCC clinical characteristics. The Kaplan-Meier plot was used to assess survival rates, and the Tumor Immune Estimation Resource (TIMER) database was used to examine the correlation between SEC14L2 expression and tumor immune cell infiltration. In silico tools also looked at SEC14L2 involvement in cancer pathways through its protein network. The mRNA and protein levels of SEC14L2 are notably higher in both OSCC and HNSCC tissues compared to adjacent normal tissues. Upregulation of SEC14L2 was associated with advanced tumor stages, grades, metastasis, HPV-negative, and TP53 mutations in cancer patients. In addition, the high expression of SEC14L2 was negatively correlated with the poor survival of cancer patients and the infiltration of diverse immune cells in cancer patients. According to the findings of this investigation, SEC14L2 is significantly elevated in OSCC/HNSCC patients and associated with a worse prognosis. More investigation and clinical studies are required to completely understand the therapeutic potential of SEC14L2 in HNSCC and convert these findings into better patient outcomes.

Prognostic Significance of Lymph Node Ratio in Predicting the Outcome of Oral Squamous Cell Carcinoma – A Retrospective Study

Abstract Introduction: The lymph node status is a very important prognostic factor in head-and-neck cancer. The presence of metastatic lymph nodes will reduce the overall survival by 50%. Lymph node ratio (LNR) is defined as the ratio of the number of positive lymph nodes to the total number of lymph nodes dissected. The aim of the study was to investigate the prognostic value of LNR in oral squamous cell carcinoma (OSCC). Materials and Methods: Medical records of pathologically confirmed OSCC patients who reported with loco-regional recurrence from January 2017 to January 2022 were analysed. LNR and disease-free survival (DFS) were calculated for each patient. The endpoint of the study was disease-free survival. Spearman’s correlation was used to establish a correlation between DFS and LNR. Results: A total of 33 patients were included in the study. DFS was calculated for all the patients. LNR was calculated in patients with pathological N+ neck. There was a negative significant moderate correlation between LNR and DFS (Spearman’s rho = −0.593, P < 0.001). A higher LNR value of more than 0.01 was associated with a shorter DFS period. T4 tumour stage had significantly higher LNR. A positive significant moderate correlation was found between LNR and tumour stage (Spearman’s rho = 0.703, P = 0.01). As the T stage increased, the LNR ratio also increased. In the present study, tumour subsite tongue was associated with significantly higher LNR (P = 0.001). Discussion: LNR can be considered an independent prognostic parameter for DFS in OSCC patients with cervical lymph node metastasis.

The Role of Infiltrated T Lymphocyte in Oral Squamous Cell Carcinoma: Insights into Clinicopathological Characteristics and Prognosis.

To compare and analyze the presence of CD4+ and CD8 + lymphocyte infiltrates in Oral squamous cell carcinoma (OSCC) tissue versus adjacent tissue and their clinical significance. We enrolled a total of 152 patients diagnosed with OSCC, all of whom had confirmed diagnoses through pathological reports. Clinical and demographics data were extracted from medical records. Tissue microarrays were constructed and immunohistochemical staining for CD4 and CD8 was performed. The average number of infiltrating CD4+ T cells in OSCC tumor tissue was 1026.22±1163.36 cells/mm2, which did not significantly differ from the count in adjacent tissue, which was 1163.36±1013.23 cells/mm2. However, the number of CD8+ T cell infiltration in tumor tissue was significantly higher than in adjacent tissue (655.25±705.70 vs 504.56±659.26 cells/mm2, p = 0.026). We observed that, among patients who consumed alcohol, the CD4+ T cell infiltration in tumor tissue being significantly lower than that in adjacent tissue (P=0.036). Moreover, the CD8+ T cell infiltration in cancer tissue was significantly higher than in adjacent tissue for T1-2 patients (p=0.005). Patients with higher CD8+ T cell in tumor tissue exhibited significantly improved overall survival (p = 0.043). Multivariate analyses revealed that alcohol consumption had a significant impact on the number of CD4+T lymphocytes in tumor tissue (OR = 0.403, P = 0.033) while T stage was the independent factor affecting CD8+ T lymphocyte infiltration in tumor tissue (OR = 0.459, P = 0.031). OSCC patients with a higher number of CD8+ T lymphocyte infiltration in tumor tissue exhibited an improved prognosis.

Evaluation of Site And Location of Oral Squamous Cell Carcinoma among Patients Visiting at Tertiary Care Hospital Hyderabad

Background: Oral Squamous Cell Carcinoma (OSCC), a prevalent form of oral cancer, is marked by its aggressive nature and potential for metastasis. With a global five-year survival rate below 50%, the incidence of OSCC presents a significant public health challenge. The highest incidence rates are observed in Southeast Asia, correlating with the cultural practices of betel-quid and tobacco consumption. Objective: To evaluate the common sites and locations of OSCC among patients attending a tertiary care hospital in Hyderabad, with a view to identifying patterns that may guide early detection and targeted interventions. Methods: This cross-sectional study included 100 clinically diagnosed OSCC patients from Liaquat Medical University Hospital, Hyderabad, from January 2021 to February 2022. Following informed consent, detailed patient examinations were performed. Data on demographic variables, habits, and lesion sites and locations were collected using a structured proforma and analyzed using SPSS Version 25. The study adhered to the ethical guidelines of the Declaration of Helsinki. Results: The patient cohort exhibited a male predominance (77%) with a mean age of 44.28 ± 13.065 years. Betel Nut (47%) and Gutka (27%) were the most common habits among the patients. The tongue was the most frequently involved site (38%), followed by buccal/labial mucosa (27%) and gingiva (10%). OSCC was more commonly found in the maxilla (75%) than in the mandible (43%). Conclusion: The results indicate a higher occurrence of OSCC in the maxilla with the tongue being the most common site of manifestation. These findings underscore the need for targeted educational and preventive strategies at the primary healthcare level, emphasizing early diagnosis and intervention.

High expression of ACTL6A leads to poor prognosis of oral squamous cell carcinoma patients through promoting malignant progression.

The aim was to research ACTL6A's role in oral squamous cell carcinoma (OSCC). OSCC and normal samples were obtained from patients and public databases. GSEA was performed. CIBERSORT was utilized to analyze immune landscape. Kaplan-Meier survival analysis and multivariate Cox regression analysis were conducted. After knocking down ACTL6A, we performed MTT assay, transwell assays, and flow cytometry to detect the impact of knockdown. ACTL6A expressed higher in OSCC samples than normal samples. The CNV and mutation rate of TP53 was higher in ACTL6A high-expression group. TFs E2F7 and TP63 and miRNA hsa-mir-381 were significantly related to ACTL6A. ACTL6A could influence immune microenvironment of OSCC. Knockdown of ACTL6A inhibited OSCC cells' proliferation, migration, and invasion. ACTL6A was able to predict OSCC prognosis independently. ACTL6A expressed higher in OSCC than normal samples and it could be used as an independent prognostic marker in OSCC patients.

Chemerin promotes invasion of oral squamous cell carcinoma by stimulating IL-6 and TNF-α production via STAT3 activation.

Elevated levels of adipokine chemerin have been identified in oral squamous cell carcinoma (OSCC) and found to be associated with metastasis to the cervical lymph nodes. The underlying mechanism through which chemerin affects OSCC progression is unclear. The aims of this study were firstly to determine chemerin levels and cytokine concentrations in serum from patients with OSCC and in OSCC cell cultures, and secondly to observe chemerin effects on OSCC cell cytokine secretion, migration, and invasion in vitro. Serum samples were collected from 20 patients diagnosed with OSCC, including groups with (LN+) and without (LN-) cervical lymph node metastasis. A Luminex liquid suspension assay was used to quantify serum concentrations of 27 types of cytokines. Correlations between chemerin and cytokines (i.e., IL-6, IL-15, GM-CSF, RANTES, TNF-α, and VEGF) were analyzed. ELISAs (enzyme-linked immunosorbent assays) were used to determine concentrations of chemerin and selected cytokines in serum and in supernatants of OSCC cell cultures (SCC9 and SCC25 cell lines). OSCC cells were stimulated with human recombinant chemerin, STAT3 inhibitor, or IL-6 together with TNF-α neutralizing antibodies. Phosphorylated STAT3 protein levels were measured with western blot analysis. OSCC cell migration and invasion were investigated with Transwell assays. Compared to the LN- group, OSCC patients with cervical lymph node metastasis had higher levels of IL-6 (P = 0.006), IL-15 (P = 0.020), GM-CSF (P = 0.036), RANTES (P = 0.032), TNF-α (P = 0.005), VEGF (P = 0.006), and chemerin (P = 0.001). Patients' serum chemerin levels correlated directly with IL-6, GM-CSF, TNF-α, and VEGF levels in OSCC patients. Exogenous recombinant chemerin treatment promoted secretion of IL-6 and TNF-α via activation of STAT3 in OSCC cells. Chemerin induced OSCC-cell migration and invasion, and these effects were reduced by IL-6 and TNF-α neutralizing antibodies. Our findings indicate that chemerin may play a role in advancing OSCC progression by increasing production of IL-6 and TNF-α, perhaps via a mechanism involving STAT3 signaling.

Abstract 6843: Comprehensive multi-omics approaches for identification of genetic alterations in head and neck squamous cell carcinoma

Abstract Background: Head and neck squamous cell carcinoma (HNSCC) is one of the most difficult and challenging malignancies, with a high level of heterogeneity and a wide range of treatment responses, regardless of the clinical stage. Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer and accounts for over 90% of cancers that develop in the mucosal epithelium of the oral cavity. Additional carcinogenic risk factors, including tobacco, alcohol, and HPV infection are also associated with the pathogenesis of oral carcinogenesis. Unfortunately, today the failure of standard treatment modalities such as surgery, radiotherapy, and chemotherapy underscore the need for comprehensive genomic profiling to provide a better picture of the genetic alterations and gain an improved understanding of the complex signaling networks involved in the development of potential treatment resistance as well as the identification of novel biomarkers that discriminate between smokers and non-smokers. Methods: A retrospective analysis was performed on biopsied Formalin-Fixed Paraffin-Embedded (FFPE) samples from OSCC patients with and without a history of smoking and treated +/- chemotherapy. Patient samples representing matched normal tissue to serve as controls were compared to tumor squamous cell carcinoma samples and profiled using a single assay panel that includes 517 genes by both DNA and RNA NGS, microsatellite instability (MSI), and tumor mutational burden (TMB). Further analysis was also performed using the NanoString nCounter® PanCancer Immune Profiling Panel (PCIP), 770-comprehensive gene expression panel Results: The Neo ComprehensiveTM Solid Tumor pan cancer assay enabled simultaneously analysis of both DNA and RNA in one integrated workflow with an accompanying DragenTM bioinformatics analysis platform and provided comprehensive genomic profiling of sequence and structural variants, as well as genomic signatures such as TMB and MSI in OSCC patients. Utility of the NanoString PCIP highlighted immune-relevant gene expression changes within the different sample cohorts. The detailed molecular information highlighted by our study emphasizes the need for improved patient classification based on smoking status in the management of OSCC and also in establishing potential therapeutic options based on the many altered cell signaling pathways that we identified. By combining a multi-omics approach with expression data for immune-related genes and associated overall survival data, we provide an effective strategy and workflow for the identification of prognostic biomarkers in OSCC. Citation Format: Kirsteen Maclean, Qinqin Zha, Lakshmi Chandramohan, Anna Juncker-Jensen. Comprehensive multi-omics approaches for identification of genetic alterations in head and neck squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6843.

Abstract 1727: Silencing of novel m6A reader PRRC2A as a therapeutic strategy for oral cancer

Abstract Background: Oral squamous cell carcinoma (OSCC) poses a substantial global health challenge characterized by limited treatment options and unfavorable prognoses. Recent research has illuminated the pivotal role of N6-methyladenosine (m6A) modification and its regulators in cancer biology. However, the precise involvement of a novel m6A regulator (m6A reader), PRCC2A in OSCC remains inadequately understood. Objective: This study aims to unravel the role of PRCC2A in OSCC and ascertain its potential as both a diagnostic biomarker and a therapeutic target. Methods: We collected 76 OSCC tumor samples and 38 adjacent non-tumor samples from OSCC patients. Comprehensive analyses, including RT-qPCR, western blotting, histopathological examination, and associations with clinicopathological features, were performed to assess PRRC2A expression in cancer tissues. Furthermore, we explored its links with key factors like metastasis and its implications for patient prognosis. In vitro experiments were conducted using OSCC cell lines and human normal oral keratinocytes (NOKs). PRCC2A knockdown in OSCC cell lines was assessed for its effects on cell proliferation, apoptosis, cell cycle, migration, invasion, and sphere-forming abilities. The study also delved into its impact on immune cell infiltration and involvement in biological pathways. Results: Our investigation unveiled significant overexpression of PRCC2A in OSCC tissue samples and cell lines, relative to adjacent non-tumor tissues and NOKs (P < 0.001). These findings were further validated by the Cancer Genome Atlas - Head and Neck Squamous Cell Carcinoma (TCGA-HNSC) dataset. PRCC2A expression displayed significant correlations with nodal metastasis, higher tumor grades, and advanced cancer stages in OSCC samples, suggesting its crucial role in driving cancer progression and aggressiveness. Silencing PRCC2A in vitro led to reduced metastasis, diminished tumor colony formation, and increased apoptosis in oral cancer cell lines. Furthermore, the study uncovered PRCC2A intricate connections with immune regulatory genes, highlighting its potential to influence the tumor immune microenvironment. Conclusion: PRCC2A emerges as a promising candidate for both diagnosis and therapeutic intervention in OSCC. Its pronounced overexpression in oral cancer tissues, coupled with its associations with metastasis and intricate interactions with immune regulatory networks, underscores its significance in the context of oral cancer malignancies. This research offers valuable insights into the multifaceted role of PRCC2A in OSCC and lays the groundwork for future investigations and potential clinical applications. Citation Format: Balachander Kannan, Vijayashree Priyadharsini Jayaseelan, Senthil MuruganM, Paramasivam Arumugam. Silencing of novel m6A reader PRRC2A as a therapeutic strategy for oral cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1727.

Abstract 5494: Spatial organization between claudin and the tumor microenvironment in head and neck squamous cell carcinomas

Abstract Background: Head and neck squamous cell carcinoma (HNSCC) is the sixth leading form of cancer worldwide and one of the most difficult and challenging malignancies, with a high level of heterogeneity and a wide range of treatment responses. Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer and accounts for over 90% of cancers that develop within the mucosal epithelium of the oral cavity. Additional carcinogenic risk factors, including tobacco, alcohol and HPV infection are also associated with the pathogenesis of oral carcinogenesis. Unfortunately, today the failure of standard treatment modalities, such as surgery, radiotherapy, and chemotherapy underscore the need to identify better biomarkers of this disease. Advances, especially in spatial technology have created unprecedented opportunities to identify cell types and biomarkers of disease processes, revealing important relationships within the tumor microenvironment (TME) that allow a detailed characterization of specific cell phenotypes defined by co- or lack of expression of multiple markers that may help in predicting clinical responses and mechanisms of resistance to therapy. Recent findings indicate that abnormal expression of claudins (CLDNs) is closely related to the occurrence, progression and prognosis of many solid tumors. Specifically, CLDN6 is expressed in numerous tumors but rarely found in adult normal tissues making it a potential therapeutic target in head and neck tumor types. To investigate this further, expression of CLDN6 and the its relationship with changes within the TME of cohort OSCC tumors was determined using a proprietary comprehensive spatial workflow and gene expression analysis. Methods: A retrospective analysis was performed on biopsied Formalin-Fixed Paraffin-Embedded (FFPE) samples from OSCC patients with and without a history of smoking and treated +/- chemotherapy. Patient samples representing matched normal tissue to serve as controls were compared to samples derived from OSCC tumors. In order to perform a comprehensive expression profiling of the TME from OSCC tumors we used the spatial MultiOmyx™ immunofluorescence (IF) multiplexing assay with transcriptomic information from bulk mRNA gene expression acquired using the NanoString nCounter® PanCancer IO 360™ panel that includes the Tumor Inflammation Signature (TIS), as well as targets that characterize immune hot, desert, and cold regions in the stroma and tumor epithelium. Results: We characterized the expression of CLDN6 across the different cohorts of OSCC samples and further investigated the relationship within the tumor immune microenvironment coupled to genes related to the prognosis of OSCC. A better understanding of the TME and gene expression profiling of OSCC tumors and the effect of smoking will allow us to tailor the treatment of patients to continue to improve outcomes. Citation Format: Kirsteen Maclean, Lakshmi Chandramohan, Maryam Rohafza, Harry Nunns, Erinn Parnell, Qingyan Au, Anna Juncker-Jensen. Spatial organization between claudin and the tumor microenvironment in head and neck squamous cell carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5494.

Abstract 2451: Investigation of SIRT6 usefulness as a novel biomarker for oral cancer

Abstract Introduction: SIRT6 is one of the seven human sirtuin genes and is known to function as an onco-suppressor gene in colorectal and ovarian cancers, although it is up-regulated in other cancers. Thus, SIRT6 is considered performing both tumor-suppressing and promoting roles. However, the association of SIRT6 with oral squamous cell carcinoma (OSCC) and its role in OSCC pathogenesis are currently unclear. Currently, SCC or CYFRA are used as a tumor marker to assist in the diagnosis of OSCC in a clinical setting whereas its sensitivity is low. Therefor the development of a novel biomarker for early diagnosis and identification of new therapeutic targets is critical to resolve the pressing clinical issues related to the management of OSCC. This study aimed to investigate the expression and the relevance of SIRT6 in patients with OSCC and its potential as a biomarker for early detection and prognosis prediction. Materials and Methods: This study enrolled 78 patients with OSCC and 9 patients with carcinoma in situ (CIS). The OSCC patients had undergone surgery or chemoradiotherapy (51 surgery and 27 chemoradiotherapy). The CIS patients had undergone surgery. Samples were also obtained from 10 patients with oral potentially malignant disorders (OPMDs). Biopsied or surgical resected samples were used for the study. We obtained 21 noncancerous tissues as normal tissues from the adjacent noncancerous tissues after tumor resection. Immunohistochemistry, quantitative real-time RT-PCR, and microarray analyses were performed to determine SIRT6 expression and its association with clinicopathological features in OSCC, CIS, and OPMDs using clinical paraffin embedded specimens. Results: SIRT6 mRNA levels were higher in OSCC tissues than those in noncancerous tissues (p<0.05). And SIRT6 protein expression levels were higher in OSCC, CIS and OPMDs tissues than those in noncancerous tissues (p<0.05). SIRT6 expression was predominant in patients aged ≥65 years and significantly correlated with shorten overall survival. In the microarray analysis, some SIRT6-associated genes, such as ANXA2 was significantly up-regulated, and PIGC and RGPD4 were down-regulated in OSCC. Conclusion: SIRT6 plays a role in tumor homeostasis, leading to a poor prognosis in OSCC. SIRT6 may represent a novel target not only for the treatment, but also as a prognostic marker in OSCC. Citation Format: Haruka Yoshii, Ami Shimoda, Kenji Mitsudo, Mitomu Kioi. Investigation of SIRT6 usefulness as a novel biomarker for oral cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2451.

Abstract 1181: Therapeutic efficacy by Streptococcus salivarius as a probiotic in a preclinical model of oropharyngeal carcinoma

Abstract Streptococcus salivarius is a gram-positive, non-pathogenic bacteria found in the oral cavity and upper respiratory tract. This bacterium has been shown to possess antimicrobial properties with the potential to cause activation of natural killer (NK) cells and induction of anti-tumorigenic cytokines such as interferon-gamma and interleukin-12 (IL-12). There is a high abundance of this bacteria in the saliva in oral squamous cell carcinoma patients. Moreover, Streptococcus-reactive cytotoxic T cells were associated with recurrence-free survival. Nevertheless, there is a considerable lack of information regarding the impact of S. salivarius on intratumoral immune responses and its potential as a cancer therapeutic. This study aimed to characterize the immune responses in the tumor microenvironment by S. salivarius in combination with programmed cell death protein 1 (anti-PD-1) therapy and its therapeutic efficacy. We expect that S. salivarius will cooperate with immune checkpoint inhibitors, activating antitumor immune responses. For this project, we used a preclinical murine model where an HPV+ oropharyngeal cancer cell line named mEER was implanted subcutaneously or in the tongue of the mice. We treated with or without S. salivarius and/or anti-PD-1. First, S. salivarius was administered intratumorally on subcutaneous tumors and treated or not with anti-PD-1 therapy administered intraperitoneally. We measured tumor volume and quantified different immune cells by flow cytometry. While anti-PD-1 treated mice showed a continuous increase in tumor volume, the ones treated with anti-PD-1 and S. salivarius reduced the growth rate starting at day 20. Mice treated with anti-PD1 and S. salivarius showed increased CD4+ T cells and myeloid-derived suppressor cells (MDSCs) compared to anti-PD-1 treatment alone. Secondly, we implanted the mice with tongue tumors and applied S. salivarius topically in the oral cavity with or without anti-PD-1. The use of S. salivarius contributed to an increase in CD4+T cells and activation of CD8+T cells and NK cells. The combination of anti-PD-1 with S. salivarius did not further enhance the activation of these cells. Nevertheless, 80% of mice receiving anti-PD-1 with S. salivarius responded to the therapy, whereas 63% responded while receiving only anti-PD-1. In conclusion, Streptococcus salivarius as a probiotic, affected tumor development and immune cell infiltration in oropharyngeal cancer. Future analyses will allow us to explore the effect of the probiotic on the tumor microenvironment and improve colonization in the oral cavity. Citation Format: Jennifer Diaz, Michael Rivera, Kamila A. Del Valle, Edna E. Piñero, Filipa Vitorino, Jorge R. Ortiz, Stephanie M. Estremera. Therapeutic efficacy by Streptococcus salivarius as a probiotic in a preclinical model of oropharyngeal carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1181.

Abstract 3783: Oral squamous carcinoma, LN metastasis

Abstract Due to genetically unstable nature of cancer cells, they give rise to genetically different variant subclones inside a single tumor. To enable the development of more efficacious therapies, it is crucial to understand cancer heterogeneity and subclone characteristics. Oral squamous cell carcinoma (OSCC) has high heterogeneity and plasticity. C-X3-C motif ligand 1 (CX3CL1) is the chemokine with anti- and pro-tumor functions. Our study reported CX3CL1 functions on cancer subclones with different phenotypes, both in vivo and in vitro. We found that Mouse OSCC (MOC) 1 and MOC2 cells responded in similar manners to CX3CL1 in vitro. However, in vivo, CX3CL1 increases cellular differentiation in indolent cancer (MOC1) while increasing metastasis in aggressive cancer (MOC2). These phenomena are influenced by different phenotypic tumor microenvironments created by indolent and aggressive cancer. From there, we established that when aggressive cancer cells gain CX3CL1 expression, they stimulate protumor immune system, promoting cancer metastasis via lymphatic vessels. A similar phenomenon was observed in metastatic OSCC patient samples, where CX3CL1 expression became intense in metastasis regions, consistent with aggressive subclone (MOC2) character; we correctly predicted patient outcomes by using CX3CL1 as prognostic indicator for long-term follow-up in metastatic OSCC patients. In conclusion, CX3CL1 is the key factor for stimulating aggressive cancer subclones to create new lymphatic networks for lymph node metastasis. Citation Format: Hotaka Kawai, Htoo Shwe Eain, Toshiaki Ohara, May Wathone Oo, Yamin So, Hitoshi Nagatsuka. Oral squamous carcinoma, LN metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3783.