A deep learning model to predict Ki-67 positivity in oral squamous cell carcinoma

Anatomical pathology is undergoing its third revolution, transitioning from analogical to digital pathology and incorporating new artificial intelligence technologies into clinical practice. Aside from classification, detection, and segmentation models, predictive models are gaining traction since they can impact diagnostic processes and laboratory activity, lowering consumable usage and turnaround time. Our research aimed to create a deep-learning model to generate synthetic Ki-67 immunohistochemistry from Haematoxylin and Eosin (H&E) stained images. We used 175 oral squamous cell carcinoma (OSCC) from the University Federico II's Pathology Unit's archives to train our model to generate 4 Tissue Micro Arrays (TMAs). We sectioned one slide from each TMA, first stained with H&E and then re-stained with anti-Ki-67 immunohistochemistry (IHC). In digitised slides, cores were disarrayed, and the matching cores of the 2 stained were aligned to construct a dataset to train a Pix2Pix algorithm to convert H&E images to IHC. Pathologists could recognise the synthetic images in only half of the cases in a specially designed likelihood test. Hence, our model produced realistic synthetic images. We next used QuPath to quantify IHC positivity, achieving remarkable levels of agreement between genuine and synthetic IHC. Furthermore, a categorical analysis employing 3 Ki-67 positivity cut-offs (5%, 10%, and 15%) revealed high positive-predictive values. Our model is a promising tool for collecting Ki-67 positivity information directly on H&E slides, reducing laboratory demand and improving patient management. It is also a valuable option for smaller laboratories to easily and quickly screen bioptic samples and prioritise them in a digital pathology workflow.

Salivary biomarkers for early detection of oral squamous cell carcinoma (OSCC) and head/neck squamous cell carcinoma (HNSCC): A systematic review and network meta-analysis

Oral cancer became a very common condition. WHO estimates that there are 4 cases of lip and oral cavity cancer for every 100,000 people worldwide. The early diagnosis of cancers is currently a top focus in the health sector. Recent systematic reviews and meta-analyses have identified promising biomarkers for early detection in several original research investigations. However, it is still unclear the quality of these evidence and which biomarker performs the best in terms of early detection. Therefore, the objective was, to map the methodological and reporting quality of available oral squamous cell carcinoma (OSCC) or head/neck squamous cell carcinoma (HNSCC) systematic reviews and meta-analysis. Secondly, to evaluate diagnostic accuracy of salivary biomarkers for common craniofacial cancers and to compare the diagnostic value of different salivary biomarkers. PubMed, Scopus, Web of Science, Embase and Cochrane Library electronic databases were used to map the methodological and reporting quality of the systematic reviews and meta-analysis conducted on the HNSCC, OSCC using the AMSTAR-2 checklist. The inclusion criteria were systematic reviews and meta-analysis published in the topic of HNSCC and OSCC biomarkers. Exclusion criteria were no animal studies; original primary studies, due to limitation of competency in other languages articles with language other than English were excluded. The sensitivity and specificity were calculated for salivary biomarkers and ranked according to network meta-analysis principles. A total of N = 5893 patients were included from four meta-analysis studies. All together, these included n = 37 primary studies. n = 94 biomarkers were pooled from these four meta-analyses and categorised into the stages at which they were detected (I-IV). In OSCC, Chemerin and MMP-9 displayed the highest sensitivity, registering 0.94 (95% CI 0.78, 1.00) and a balanced accuracy of 0.93. Phytosphingosine closely followed, with a sensitivity of 0.91 (95% CI 0.68, 0.99) and a balanced accuracy of 0.87. For HNSCC, the top three biomarkers are Actin, IL-1β Singleplex, and IL-8 ELISA. Actin leads with a sensitivity of 0.91 (95% CI 0.68-0.99), a specificity of 0.67, and an overall accuracy of 0.79. Subsequently, IL-1β Singleplex exhibits a sensitivity of 0.62 (95% CI 0.30-0.88), a specificity of 0.89, and an accuracy of 0.75, followed by IL-8 ELISA with a sensitivity of 0.81 (95% CI 0.54-0.97), a specificity of 0.59, and an accuracy of 0.70. In conclusion, there was highest sensitivity for MMP-9 and chemerin salivary biomarkers. There is need of further more studies to identify biomarkers for HNSCC and OSCC.

Insights into the role of the N6-methyladenosine reader IGF2BP3 in the progression of oral squamous cell carcinoma and its connection to cell-cycle control

The genome of oral squamous cell carcinoma (OSCC) has been extensively characterized via bulk sequencing, revealing a multitude of genetic changes. The gene IGF2BP3, which encodes for the insulin-like growth factor 2 mRNA-binding protein 3, has been observed to be highly expressed in several types of cancer. This finding suggests that IGF2BP3 may play a significant role in the initiation and advancement of cancer. Nevertheless, the mechanisms by which IGF2BP3 contribute to OSCC are yet to be fully understood. In this study, we have observed that IGF2BP3 exhibits overexpression in OSCC. Based on our findings from bulk sequencing analysis, we have concluded that IGF2BP3 could potentially serve as a biomarker for predicting poor prognosis in OSCC. Moreover, it has been demonstrated that IGF2BP3 exhibits a significant association with the initiation and advancement of tumors both in vivo and in vitro. The evaluation of IGF2BP3 expression levels in relation to the cell cycle stage was conducted using single-cell RNA sequencing data. Tumor cells characterized by elevated IGF2BP3 expression demonstrated a higher percentage of cells in the G2/M transition phase. This study presents new findings indicating that the molecular target IGF2BP3 can serve as a prognostic indicator for tumors and has an impact on the development and progression of OSCC by influencing the regulation of the cell cycle.

Potential targets of diosgenin for the treatment of oral squamous cell carcinoma and their bioinformatics and transcriptional profiling analyses

Diosgenin can inhibit the proliferation and cause apoptosis of various tumor cells, and its inhibitory effect on oral squamous cell carcinoma (OSCC) and its mechanism are still unclear. In this study, we predicted the targets of diosgenin for the treatment of OSCC through the database, then performed bioinformatics analysis of the targets, and further verified the effect of diosgenin on the activity of OSCC cell line HSC-3, the transcriptional profile of the targets and the molecular docking of the targets with diosgenin. The results revealed that there were 146 potential targets of diosgenin for OSCC treatment, which involved signaling pathways such as Ras, TNF, PI3K-AKT, HIF, NF-κB, and could regulate cellular activity through apoptosis, autophagy, proliferation and differentiation, inflammatory response, DNA repair, etc. Diosgenin significantly inhibited HSC-3 cell activity. The genes such as AKT1, MET1, SRC1, APP1, CCND1, MYC, PTGS2, AR, NFKB1, BIRC2, MDM2, BCL2L1, MMP2, may be important targets of its action, not only their expression was regulated by diosgenin but also their proteins had a high binding energy with diosgenin. These results suggest that diosgenin may have a therapeutic effect on OSCC through AKT1, MMP2 and other targets and multiple signaling pathways, which is of potential clinical value.

IL-1α facilitates GSH synthesis to counteract oxidative stress in oral squamous cell carcinoma under glucose-deprivation

Understanding the intrinsic mechanisms underpinning cancer metabolism and therapeutic resistance is of central importance for effective nutrition-starvation therapies. Here, we report that Interleukin 1A (IL1A) mRNA and IL-1α protein facilitate glutathione (GSH) synthesis to counteract oxidative stress and resistance against nutrition-starvation therapy in oral squamous cell carcinoma (OSCC). The expression of IL1A mRNA was elevated in the case of OSCC associated with unfavorable clinical outcomes. Both IL1A mRNA and IL-1α protein expression were increased under glucose-deprivation in vitro and in vivo. The transcription of IL1A mRNA was regulated in an NRF2-dependent manner in OSCC cell lines under glucose-deprivation. Moreover, the IL-1α conferred resistance to oxidative stress via GSH synthesis in OSCC cell lines. The intratumoral administration of siRNAs against IL1A mRNA markedly reversed GSH production and sensitized OSCC cells to Anlotinib in HN6 xenograft models. Overall, the current study demonstrates novel evidence that the autocrine IL-1α favors endogenous anti-oxidative process and confers therapeutic resistance to nutrition-starvation in OSCCs.

Histomorphometric Image Classifier of Different Grades of Oral Squamous Cell Carcinoma Using Transfer Learning and Convolutional Neural Network

BACKGROUND

Machine learning is an emerging technology in health care field with aim of fundamentally revamping the traditional system and aiding medical practitioners. The histopathological analysis of oral cancers is crucial for pathologist to ascertain its grading. Therefore, this study attempts to grade the various stained tissue samples of OSCC (Oral Squamous Cell Carcinoma) patients using different deep-learning models.

METHODS

A dataset of 120 histopathological images of OSCC was collected and classified as well-differentiated (40), moderately differentiated (40), and poorly differentiated (40) according to Broders' grading system. The CNN (Convoluted neural networks) architectures were based on the pre-trained neural network models VGG16 (Visual Geometry Group16), VGG19 (Visual Geometry Group19), RESNET50 (Residual Network50), and DENSENET121 (Dense Network121) models for image analysis.

RESULTS

At a magnification of 4x, all four models achieved the highest test accuracy of 66.67%. DENSENET121 scored the highest validation accuracy of 81%. At 10x, RESNET50, VGG19, and DENSENET121 achieved the highest test accuracy of 90.9% and VGG19 achieved the highest validation accuracy of 83.3%. At 40x, the highest test accuracy of 70% was achieved by RESNET50 and DENSENET121. The validation accuracy was comparable between RESNET50, VGG16, and VGG19.

CONCLUSION

The grading of tissues with the help of deep learning in digital imaging and computational aid in the diagnosis can help in timely and effective prognosis and multi-modal treatment protocols for oral cancer patients, thus reducing the operational workload of pathologists. By systematically evaluating model performance and addressing concerns about overfitting, we develop robust models suitable for medical diagnosis.

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

Background

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.

Methods

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.

Findings

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).

Interpretation

OSCC patients with a higher number of CD8+ T lymphocyte infiltration in tumor tissue exhibited an improved prognosis.

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.

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.

LDL Receptor-Related Protein 1B Polymorphisms Associated with Increased Risk of Lymph Node Metastasis in Oral Cancer Group with Diabetes Mellitus

Oral cancer ranks fourth among malignancies among Taiwanese men and is the eighth most common cancer among men worldwide in terms of general diagnosis. The purpose of the current study was to investigate how low-density lipoprotein receptor-related protein 1B (LDL receptor related protein 1B; LRP1B) gene polymorphisms affect oral squamous cell carcinoma (OSCC) risk and progression in individuals with diabetes mellitus (DM). Three LRP1B single-nucleotide polymorphisms (SNPs), including rs10496915, rs431809, and rs6742944, were evaluated in 311 OSCC cases and 300 controls. Between the case and control groups, we found no evidence of a significant correlation between the risk of OSCC and any of the three specific SNPs. Nevertheless, in evaluating the clinicopathological criteria, individuals with DM who possess a minimum of one minor allele of rs10496915 (AC + CC; p = 0.046) were significantly associated with tumor size compared with those with homozygous major alleles (AA). Similarly, compared to genotypes homologous for the main allele (GG), rs6742944 genotypes (GA + AA; p = 0.010) were more likely to develop lymph node metastases. The tongue and the rs6742944 genotypes (GA + AA) exhibited higher rates of advanced clinical stages (p = 0.024) and lymph node metastases (p = 0.007) when compared to homozygous alleles (GG). LRP1B genetic polymorphisms appear to be prognostic and diagnostic markers for OSCC and DM, as well as contributing to genetic profiling research for personalized medicine.

Supramolecular nanodrug targeting CDK4/6 overcomes BAG1 mediated cisplatin resistance in oral squamous cell carcinoma

Chemoresistance to cisplatin remains a significant challenge affecting the prognosis of advanced oral squamous cell carcinoma (OSCC). However, the specific biomarkers and underlying mechanisms responsible for cisplatin resistance remain elusive. Through comprehensive bioinformatic analyses, we identified a potential biomarker, BCL2 associated athanogene-1 (BAG1), showing elevated expression in head and neck squamous cell carcinoma (HNSCC). Since OSCC represents the primary pathological type of HNSCC, we investigated BAG1 expression in human tumor tissues and cisplatin resistant OSCC cell lines, revealing that silencing BAG1 induced apoptosis in cisplatin-resistant cells both in vitro and in vivo. This effect led to impaired cell viability of cisplatin resistant OSCC cells and indicated a positive correlation between BAG1 expression and the G1/S transition during cell proliferation. Based on these insights, the administration of a CDK4/6 inhibitor in combination with cisplatin effectively overcame cisplatin resistance in OSCC through the CDK4/6-BAG1 axis. Additionally, to enable simultaneous drug delivery and enhance synergistic antitumor efficacy, we developed a novel supramolecular nanodrug LEE011-FFERGD/CDDP, which was validated in an OSCC orthotopic mouse model. In summary, our study highlights the potential of a combined administration of CDK4/6 inhibitor and cisplatin as a promising therapeutic regimen for treating advanced or cisplatin resistant OSCC.

LRRC59 promotes the progression of oral squamous cell carcinoma by interacting with SRP pathway components and enhancing the secretion of CKAP4-containing exosomes

Background

As a ribosome receptor, LRRC59 was thought to regulate mRNA translation on the ER membrane. Evidence suggests that LRRC59 is overexpressed in a number of human malignancies and is associated with poor prognoses, but its primary biological function in the development of oral squamous cell carcinoma (OSCC) remains obscure.

Objective

The purpose of this study is to investigate at the expression changes and functional role of LRRC59 in OSCC.

Methods

LRRC59 gene expression and correlation with prognosis of OSCC patients were first examined using the data from The Cancer Genome Atlas (TCGA) databases. Following that, a series of functional experiments, including cell counting kit-8, cell cycle analysis, wound healing assays, and transwell assays, were carried out to analyze the biological roles of LRRC59 in tumor cells. Mechanistically, we employed Tandem Affinity Purification-Mass Spectrometry (TAP-MS) approach to isolate and identify protein complexes of LRRC59. Downstream regulatory proteins of LRRC59 were verified through immunoprecipitation and immunofluorescence experiments. Furthermore, we isolated exosomes from OSCC cell supernatant and conducted co-culture experiments to examine the effect of LRRC59 knockdown on OSCC cells.

Results

In samples from OSCC patients, LRRC59 was highly expressed and correlated with poor prognoses. Moreover, the gene sets analysis based on TCGA RNA-seq data indicated that LRRC59 seemed to be strongly related with protein secretory and OSCC migration. Upregulated levels of LRRC59 are more prone to lymph node metastasis in OSCC patients. LRRC59 knockdown impaired the ability of OSCC cell proliferation, migration, and invasion invitro. Mechanistically, our TAP-MS data situate LRRC59 in a functional nexus for mRNA translation regulation via interactions with SRP pathway components, translational initiation factors, CRD-mediated mRNA stabilization factors. More importantly, we found that LRRC59 interacted with cytoskeleton-associated protein 4 (CKAP4) and promoted the formation of CKAP4-containing exosomes. We also revealed that the LRRC59-CKAP4 axis was a crucial regulator of CKAP4-containing exosome secretion in OSCC cells for migration and invasion.

Conclusions

Therefore, based on our findings, LRRC59 may serve as a potential biomarker for OSCC patients, and LRRC59-induced exosome secretion via the CKAP4 axis may serve as a potential therapeutic target for OSCC.

Interplay of p62-mTORC1 and EGFR signaling promotes cisplatin resistance in oral cancer

Cisplatin resistance poses a major challenge in the treatment of oral squamous cell carcinoma (OSCC). Deeper investigations into the mechanisms underlying this drug resistance is of great importance. Here, we used cellular assays and clinical immunohistochemistry to examine molecular pathways involved in both innate and acquired cisplatin resistance. We demonstrated that the p62-mTORC1 signaling complex plays a pivotal role, and is driven by the EGFR signaling network, specifically through the PI3K-Akt axis and the transcription factor C/EBP-β. Elevated p-mTOR expression was associated with cancer relapse and poor prognosis among oral cancer patients. Additionally, we illustrated that mTOR inhibitors enhance the cytotoxic effect of cisplatin, by employing cancer stem cell characteristics. Our work unveils fundamental mechanisms for cisplatin resistance, thereby presenting therapeutic implications for OSCC.

Lipid droplets-related Perilipin-3: potential immune checkpoint and oncogene in oral squamous cell carcinoma

BACKGROUND

Lipid droplets (LDs) as major lipid storage organelles are recently reported to be innate immune hubs. Perilipin-3 (PLIN3) is indispensable for the formation and accumulation of LDs. Since cancer patients show dysregulated lipid metabolism, we aimed to elaborate the role of LDs-related PLIN3 in oral squamous cell carcinoma (OSCC).

METHODS

PLIN3 expression patterns (n = 87), its immune-related landscape (n = 74) and association with B7-H2 (n = 51) were assessed by immunohistochemistry and flow cytometry. Real-time PCR, Western blot, Oil Red O assay, immunofluorescence, migration assay, spheroid-forming assay and flow cytometry were performed for function analysis.

RESULTS

Spotted LDs-like PLIN3 staining was dominantly enriched in tumor cells than other cell types. PLIN3high tumor showed high proliferation index with metastasis potential, accompanied with less CD3+CD8+ T cells in peripheral blood and in situ tissue, conferring immunosuppressive microenvironment and shorter postoperative survival. Consistently, PLIN3 knockdown in tumor cells not only reduced LD deposits and tumor migration, but benefited for CD8+ T cells activation in co-culture system with decreased B7-H2. An OSCC subpopulation harbored PLIN3highB7-H2high tumor showed more T cells exhaustion, rendering higher risk of cancer-related death (95% CI 1.285-6.851).

CONCLUSIONS

LDs marker PLIN3 may be a novel immunotherapeutic target in OSCC.

Resection status and margin control in intraoperative frozen sectioning analysis of oral squamous cell carcinoma

PURPOSE

Intraoperative frozen section analysis (IFSA) is a well-established procedure for determining the intraoperative soft tissue resection status in patients with oral squamous cell carcinoma (OSCC). Margin status is a major predictor of the patient´s outcome, histologically free margins of ≥ 5 mm are demanded. This study evaluates the accuracy of IFSA, the impact of margin status and the impact of intraoperative margin revision on disease-free survival (DFS) and overall survival (OS).

METHODS

This retrospective study included 213 patients with OSCC. IFSA results were compared with definitive histopathological reports, Kaplan-Meier analysis was performed. Cut-off values were calculated for resection margins considering known risk factors.

RESULTS

IFSA showed positive margins in 8 cases (3.8%). Kaplan-Meier analysis revealed no significant differences for OS or DFS if R0-status was achieved by initial resection or immediate re-resection. Final histopathological evaluation revealed false-positive IFSA in 3/8 cases (37.5%) and false-negative IFSA in 1/205 cases (0.5%). Sensitivity was 83.3% and specificity was 98.6%. Analysis of optimal cut-off values showed no general need for larger resection margins in patients with risk factors. Cut-off values were slightly higher for patients with the risk factor alcohol consumption (7 mm for OS and DFS) or pN + ECS- disease (7 mm for DFS). Optimal cut-off values for tumour-margin-distance were around 6 mm.

CONCLUSION

IFSA provides a valuable assessment method for intraoperative soft tissue resection margins. Risk factors seemingly do not significantly influence the extent of tumour resection.

Analysis of the effect of CCR7 on the microenvironment of mouse oral squamous cell carcinoma by single-cell RNA sequencing technology

BACKGROUND

Studies have shown that CCR7, an important inflammatory factor, can promote the proliferation and metastasis of oral squamous cell carcinoma (OSCC), but its role in the tumor microenvironment (TME) remains unclear. This paper explores the role of CCR7 in the TME of OSCC.

METHODS

In this work, we constructed CCR7 gene knockout mice and OSCC mouse models. Single-cell RNA sequencing (scRNA-seq) and bioinformatics were used to analyze the differences in the OSCC microenvironment between three CCR7 gene knockout mice (KO) and three wild-type mice (WT). Immunohistochemistry, immunofluorescence staining, and flow cytometry were used to analyze the expression of key genes in significantly different cell types between the KO and WT groups. An in vitro experiment was used to verify the effect of CCR7 on M2 macrophage polarization.

RESULTS

In the mouse OSCC models, the tumor growth rate in the KO group was significantly lower than that in the WT group. Eight main cell types (including tumor cells, fibroblasts, macrophages, granulocytes, T cells, endothelial cells, monocytes, and B cells) were identified by Seurat analysis. The scRNA-seq results showed that the proportion of tumor cells was lower, but the proportion of inflammatory cells was significantly higher in the KO group than in the WT group. CellPhoneDB analysis results indicated a strong interaction relationship between tumor cells and macrophages, T cells, fibroblasts, and endothelial cells. Functional enrichment results indicated that the expression level of the Dusp1 gene in the KO group was generally higher than that in the WT group in various cell types. Macrophage subclustering results indicated that the proportion of M2 macrophages in the KO group was lower than that in the WT group. In vitro experimental results showed that CCR7 can promote M2 macrophage polarization, thus promoting the proliferation, invasion and migration of OSCC cells.

CONCLUSIONS

CCR7 gene knockout can significantly inhibit the growth of mouse oral squamous cell carcinoma by promoting the polarization of M2 macrophages.

Second primary squamous cell carcinoma of the oral cavity - a retrospective cohort study of therapeutic procedures and oncological outcome

OBJECTIVES

In the presented study, the occurrence rates of second primary oral carcinomas and their prognostic relevance were analyzed.

MATERIALS AND METHODS

All patients with surgically treated oral squamous cell carcinomas within the years 2010 and 2022 in our department were included in this retrospective cohort study. Two groups were designed including patients with second primary carcinomas and patients with local tumor recurrences. Occurrence rates, tumor stages and applied therapies were assessed. Primary outcome was overall survival in dependence of the index tumor. Secondary outcomes were overall survival in dependence of local recurrences or second primary tumors.

RESULTS

An overall number of 908 patients was included in the analysis. 98 patients (10.8%) developed a second primary oral squamous cell carcinoma. Patients with second primary tumors presented significantly (p < 0.001) better overall survival in dependence of the index tumor compared to patients suffering from local recurrences. There was no significant difference in overall survival (p = 0.4) in dependence of the date of second primary tumor or local recurrence. Patients with second primary tumors were more likely to receive surgery-based therapy compared to patients with local recurrences who more frequently received definitive radiotherapy.

CONCLUSION

Our data indicates different clinical courses in terms of therapy and survival of patients suffering from second primary tumors compared to patients with local tumor recurrences. This may be due to a more aggressive biology of local recurrences and earlier detection of second primaries due to oncological follow-up of the index tumor.

CLINICAL RELEVANCE

The differentiation of local tumor recurrences and second primary tumors is of clinical relevance, as applicable therapies and resulting prognosis may differ significantly.

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

OBJECTIVE

The aim was to research ACTL6A's role in oral squamous cell carcinoma (OSCC).

METHODS

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.

RESULTS

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.

CONCLUSION

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

AIMS

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Acetyl-11-keto-beta-boswellic acid inhibits cell proliferation and growth of oral squamous cell carcinoma via RAB7B-mediated autophagy

Natural products can overcome the limitations of conventional chemotherapy. Acetyl-11-keto-beta-boswellic acid (AKBA) as a natural product extracted from frankincense, exhibited chemotherapeutic activities in different cancers. However, whether AKBA exerts inhibiting effect of oral squamous cell carcinoma (OSCC) cells growth and the mechanism need to be explored. We attempted to investigate the therapeutic effects of AKBA against OSCC and explore the mechanism involved. Here we attempt to disclose the cell-killing effect of AKBA on OSCC cell lines and try to figure out the specifical pathway. The presence of increase autophagosome and the production of mitochondrial reactive oxygen species were confirmed after the application of AKBA on OSCC cells, and RAB7B inhibition enhanced autophagosome accumulation. Though the increase autophagosome was detected induced by AKBA, autophagic flux was inhibited as the failure fusion of autophagosome and lysosome. Cal27 xenografts were established to verify the role of anti-OSCC cells of AKBA in vivo. Based above findings, we speculate that natural product AKBA suppresses OSCC cells growth via RAB7B-mediated autophagy and may serve as a promising strategy for the therapy of OSCC.

Beta-defensin index: A functional biomarker for oral cancer detection

There is an unmet clinical need for a non-invasive and cost-effective test for oral squamous cell carcinoma (OSCC) that informs clinicians when a biopsy is warranted. Human beta-defensin 3 (hBD-3), an epithelial cell-derived anti-microbial peptide, is pro-tumorigenic and overexpressed in early-stage OSCC compared to hBD-2. We validate this expression dichotomy in carcinoma in situ and OSCC lesions using immunofluorescence microscopy and flow cytometry. The proportion of hBD-3/hBD-2 levels in non-invasively collected lesional cells compared to contralateral normal cells, obtained by ELISA, generates the beta-defensin index (BDI). Proof-of-principle and blinded discovery studies demonstrate that BDI discriminates OSCC from benign lesions. A multi-center validation study shows sensitivity and specificity values of 98.2% (95% confidence interval [CI] 90.3-99.9) and 82.6% (95% CI 68.6-92.2), respectively. A proof-of-principle study shows that BDI is adaptable to a point-of-care assay using microfluidics. We propose that BDI may fulfill a major unmet need in low-socioeconomic countries where pathology services are lacking.

Enigma of Acantholytic and Clear Cell Changes in Oral Squamous Cell Carcinoma

Only limited cases have been reported about the clear cell variant of squamous cell carcinoma occurring in the oral cavity. The present study regards the case showing the histopathological features of both the clear cell and acantholytic variants of oral squamous cell carcinoma. A review of the literature has been done to understand the pathogenesis of those changes. Also, a hypothesis has been given that the clear cell changes could be the consequences of the cascades of the acantholytic process and not a separate entity. Therefore, more research is required to confirm this hypothesis and understand the prognosis of the lesion.

Impact of LINC00312 gene polymorphism coupled with habitual risks on buccal mucosa cancer

Oral squamous cell carcinoma (OSCC) is a prevalent and lethal malignancy with a diverse etiology. LINC00312 is a long intergenic non-coding RNA that functions as a signal hub to regulate the progression and treatment of head and neck cancer. The aim of this study was to evaluate the effect of LINC00312 single nucleotide polymorphisms (SNPs) on the development of oral cancer. Two LINC00312 SNPs, namely rs12497104 and rs164966, were investigated among 469 male patients with cancer of buccal mucosa and 1194 gender- and age-matched controls. No significant correlation was observed between these two SNPs and the occurrence of OSCC in the case and control groups. While assessing the clinicopathological features, carriers of at least one minor allele of rs164966 (GA and GG) were less prone to develop lymph node metastasis (adjusted odds ratio [AOR], 0.666; 95% confidence interval [CI], 0.447-0.991; p=0.045) in comparison with homozygous carriers of the major allele (AA). Subsequent stratifying surveys revealed that this genetic association with nodal spread was seen only in cases who habitually chewed betel quid (AOR, 0.616; 95% CI, 0.386-0.985; p=0.042) or smoked cigarettes (AOR, 0.612; 95% CI, 0.393-0.953; p=0.029), but undetected in cases free of these main behavioral risks. Our results indicate an interactivity of LINC00312 rs164966 with lifestyle-related risks on modulating OSCC progression.

Prediction of prognosis in oral squamous cell carcinoma using infrared microspectroscopy

BACKGROUND

Estimation of prognosis of oral squamous cell carcinoma (OSCC) is inaccurate prior to surgery, only being effected following subsequent pathological analysis of the primary tumour and excised lymph nodes. Consequently, a proportion of patients are overtreated, with an increase in morbidity, or undertreated, with inadequate margins and risk of recurrence. We hypothesise that it is possible to accurately characterise clinical outcomes from infrared spectra arising from diagnostic biopsies. In this first step, we correlate survival with IR spectra derived from the primary tumour.

METHODS

Infrared spectra were collected from tumour tissue from 29 patients with OSCC and subject to classification modelling.

RESULTS

The model had a median AUROC of 0.89 with regard to prognosis, a median specificity of 0.83, and a hazard ratio of 6.29 in univariate Cox proportional hazard modelling.

CONCLUSION

The data suggest that FTIR spectra may be a useful early biomarker of prognosis in OSCC.

Oral squamous cell carcinoma gene patterns connected with RNA methylation for prognostic prediction

OBJECTIVES

To determine whether m6A/m1A/m5C/m7G/m6Am/Ψ-related genes influence the prognosis of a patient with oral squamous cell carcinoma.

MATERIALS AND METHODS

We investigated the changes in regulatory genes using publicly available data from The Cancer Genome Atlas. Consensus clustering by RNA methylation-related regulators was used to describe oral squamous cell carcinomas (OSCCs). Then, we developed the prediction model. The tumor microenvironment was investigated using ESTIMATE. Gene set enrichment analysis was used to determine whether pathways or cell types were enriched in different groups. The association between the model and immune-related risk scores was investigated using correlation analysis.

RESULTS

We found 22 gene signatures in this analysis and then developed a predictive model that reveals the genes that are highly connected to the overall survival of OSCC patients. The survival and death rates were substantially different in the two groups (high and low risk) classified by the risk scores. The validation cohort verified the phenotypic diversity and prognostic effects of these genes.

CONCLUSION

Our data reveal that immune cell infiltration, genetic mutation, and survival potential in OSCC patients are linked to m6A/m1A/m5C/m7G/m6Am/Ψ-related genes, and we constructed a dependable prognostic model for OSCC patients.

SOD2 confers anlotinib resistance via regulation of mitochondrial damage in OSCC

OBJECTIVE

Previous studies had revealed that anlotinib had outstanding anti-tumor efficacy on oral squamous cell carcinoma. However, the underlying mechanism is still unclear.

MATERIALS AND METHODS

Anlotinib resistant OSCC cells were established and analyzed by RNA-sequencing. The correlations between SOD2 expression and anlotinib resistance were investigated in OSCC cells and PDX models. Functional assays were performed to verify the SOD2 expression and anlotinib resistance in OSCC cells.

RESULTS

Anlotinib resistant genes were enriched in the biological processes of mitochondrion organization and the gene pathway of reactive oxygen species. SOD2 expression level was positively correlated with the resistance of anlotinib in OSCC cells and PDX models. Higher SOD2 expression of OSCC cells was more resistant to anlotinib. Anlotinib induced ROS generation, apoptosis and mitochondrial damage in OSCC cells, which can be enhanced by SOD2 knockdown and decreased by SOD2 overexpression. Mitochondrial damage was identified as swelling and cristae disappearance morphology under TEM, decreased mitochondrial membrane potential and lower MFN2 expression.

CONCLUSIONS

SOD2 may be capable of protecting mitochondria by downregulating ROS generation, which contributes to the resistance of anlotinib in OSCC cells. SOD2 can be utilized as a potential therapeutic target to improve the anti-cancer efficacy of anlotinib in OSCC.

Immune checkpoint CD161/LLT1-associated immunological landscape and diagnostic value in oral squamous cell carcinoma

An active host adaptive response is characterized by the existence of programmed cell death protein 1 (PD-1)+ /IFN-γ+ cytotoxic T cells and IFN-γ-induced PD-L1+ tumor cells (TCs), which predicts high response rate to anti-PD-1/L1 therapy. Recently, CD161 and its ligand LLT1 (CLEC2D) have been identified as an emerging checkpoint for immunotherapy. Clarifying its heterogeneous clinical expression pattern and its immune landscape is a prerequisite for maximizing the response rate of CD161 blockade therapy in a specific population of oral squamous cell carcinoma (OSCC) patients. Here, we investigated the expression pattern of CD161/LLT1 and its association with major immunocytes (T cells, B cells, NK cells, and macrophages) by multiplex immunofluorescence, immunohistochemistry, and flow cytometry in 109 OSCC tissues and 102 peripheral blood samples. TCs showed higher LLT1 levels than tumor infiltrating lymphocytes (TILs), whereas CD161 was highly expressed in CD8+ T cells at the tumor front, which was decreased in paracancerous tissue. High expression of TC-derived LLT1 (LLT1TC ) conferred poor clinical outcomes, whereas higher CD161+ and LLT1+ TILs were associated with better prognosis. Meanwhile, patients with high LLT1TC showed a decreased ratio of CD8+ /Foxp3+ T cells in situ, but CD161+ TILs correlated with more peripheral CD3+ T cells. Interestingly, treatment of OSCC patients with nivolumab (anti-PD-1) could restore tumoral CD161/LLT1 signal. Furthermore, an OSCC subgroup characterized by high LLT1+ TCs and low CD161+ CD8+ T cells showed fewer peripheral T cells and a higher risk of lymph node metastasis, leading to a shorter 5-year survival time (29%). More LLT1TC at the invasive front was another risk characteristic of exhausted T cells. In conclusion, in view of this heterogeneity, the LLT1/CD161 distribution pattern should be determined before CD161-based immunotherapy.

A novel lysosome-related prognostic signature associated with prognosis and immune infiltration landscape in oral squamous cell carcinoma

Background

Predicting the outcome of oral squamous cell carcinoma (OSCC) is challenging due to its diverse nature and intricate causes. This research explores how lysosome-associated genes (LRGs) might forecast overall survival (OS) and correlate with immune infiltration in OSCC patients.

Methods

We analyzed OSCC patients' LRGs' mRNA expression data and clinical details from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). Through univariate Cox regression, we pinpointed LRGs with prognostic potential. A signature comprising 12 LRGs linked to prognosis was developed via the Least Absolute Shrinkage and Selection Operator (LASSO) in a training dataset. Patients were classified as higher or lower risk based on their risk scores, and the prognostic independence of the risk score was assessed using multivariate analysis. The model's robustness and precision were confirmed through bioinformatics in the GEO test set. Differential gene expression analysis between risk groups highlighted functional disparities, while various immune evaluation methods elucidated immune differences.

Results

The prognostic framework utilized 12 LRGs (SLC46A3, MANBA, NEU1, SDCBP, BRI3, TMEM175, CD164, GPC1, SFTPB, TPP1, Biglycan (BGN) and TMEM192), showing that higher risk was associated with poorer OS. This set of genes independently predicted OS in OSCC, linking LRGs to cellular adhesion and extracellular matrix involvement. Initial assessments using ssGSEA and CIBERSORT suggested that the adverse outcomes in the higher-risk cohort may be tied to immune system deregulation.

Conclusion

Twelve-LRGs signature has been identified for OSCC prognosis prediction, offering novel directions for lysosome-targeted therapies against OSCC.

State of the Art in the Diagnosis and Assessment of Oral Malignant and Potentially Malignant Disorders: Present Insights and Future Outlook-An Overview

Oral Potentially Malignant Disorder (OPMD) is a significant concern for clinicians due to the risk of malignant transformation. Oral Squamous Cell Carcinoma (OSCC) is a common type of cancer with a low survival rate, causing over 200,000 new cases globally each year. Despite advancements in diagnosis and treatment, the five-year survival rate for OSCC patients remains under 50%. Early diagnosis can greatly improve the chances of survival. Therefore, understanding the development and transformation of OSCC and developing new diagnostic methods is crucial. The field of oral medicine has been advanced by technological and molecular innovations, leading to the integration of new medical technologies into dental practice. This study aims to outline the potential role of non-invasive imaging techniques and molecular signatures for the early detection of Oral Malignant and Potentially Malignant Disorders.

Neoadjuvant Radiochemotherapy Alters the Immune and Metabolic Microenvironment in Oral Cancer-Analyses of CD68, CD163, TGF-β1, GLUT-1 and HIF-1α Expressions

BACKGROUND

The first-line treatment of oral squamous cell carcinoma (OSCC) involves surgical tumor resection, followed by adjuvant radio(chemo)therapy (R(C)T) in advanced cases. Neoadjuvant radio- and/or chemotherapy has failed to show improved survival in OSCC. Recently, neoadjuvant immunotherapy has shown promising therapeutic efficacy in phase 2 trials. In this context, the addition of radio- and chemotherapy is being reconsidered. Therefore, a better understanding of the tumor-biologic effects of neoadjuvant RCT would be beneficial. The current study was conducted on a retrospective cohort of patients who received neoadjuvant RCT for the treatment of oral cancer. The aim of the study was to evaluate the influence of neoadjuvant RCT on the immunological tumor microenvironment (TME) and hypoxic and glucose metabolisms.

METHODS

A cohort of 45 OSSC tissue samples from patients were analyzed before and after RCT (total 50.4 Gy; 1.8 Gy 5× weekly; Cisplatin + 5-Fluorouracil). Immunohistochemistry for CD68, CD163, TGF-β, GLUT-1 and HIF-1α was performed using tissue microarrays and automated cell counting. Differences in expression before and after RCT and associations with histomorphological parameters (T-status, N-status) were assessed using the Mann-Whitney U test.

RESULTS

Tumor resection specimens after neoadjuvant RCT showed a significant decrease in CD68 infiltration and a significant increase in CD163 cell density. The CD68/CD163 ratio was significantly lower after RCT, indicating a shift toward M2 polarization. The GLUT-1 and HIF-1α expressions were significantly lower after RCT. Larger tumors (T3/T4) showed a lower GLUT-1 expression. Other biomarkers were not associated with the T- and N-status.

CONCLUSIONS

Neoadjuvant RCT with 50.4 Gy induced a shift toward the M2 polarization of macrophages in the TME. This change in immune composition is not favorable and may be prognostically negative and counteract immunotherapeutic approaches. In addition, the decreased expressions in GLUT-1 and HIF-1α indicate reductions in the glucose metabolism and hypoxic energy metabolism in response to "high dose" neoadjuvant RCT, which may be therapeutically desirable.

Ubiquitin-specific protease 14 targets PFKL-mediated glycolysis to promote the proliferation and migration of oral squamous cell carcinoma

Aberrant upregulation of the ubiquitin-specific protease 14 (USP14) has been found in some malignant tumors, including oral squamous cell carcinoma (OSCC). In this study, we further demonstrated that aberrantly overexpressed USP14 was also closely related to adverse clinicopathological features and poor prognosis in patients with OSCC, so we hypothesized that USP14 might act as a tumor-promoting factor during the progression of OSCC. Notably, we originally proved that USP14 is a deubiquitinating enzyme for phosphofructokinase-1 liver type (PFKL), a key rate-limiting enzyme involved in the glycolytic pathway. USP14 interacts with PFKL and enhances its stability through deubiquitination in OSCC cells, which in turn enhances PFKL-mediated glycolytic metabolism and ultimately promote cellular proliferation, migration, and tumorigenesis. In this work, we have also demonstrated for the first time that USP14 is a critical regulator of glycolysis in OSCC and verified a novel mechanism whereby it is involved in tumor metastasis and growth. Collectively, our findings provide novel insights into the tumor-promoting role of USP14 and establish mechanistic foundations for USP14-targeting therapies.

NANOS1 restricts oral cancer cell motility and TGF-ß signaling

Oral squamous cell carcinoma (OSCC) is the most frequent type of cancer of the head and neck area accounting for approx. 377,000 new cancer cases every year. The epithelial-to-mesenchymal transition (EMT) program plays an important role in OSCC progression and metastasis therefore contributing to a poor prognosis in patients with advanced disease. Transforming growth factor beta (TGF-ß) is a powerful inducer of EMT thereby increasing cancer cell aggressiveness. Here, we aimed at identifying RNA-binding proteins (RBPs) that affect TGF-ß-induced EMT. To this end we treated oral cancer cells with TGF-ß and identified a total of 643 significantly deregulated protein-coding genes in response to TGF-ß. Of note, 19 genes encoded RBPs with NANOS1 being the most downregulated RBP. Subsequent cellular studies demonstrated a strong inhibitory effect of NANOS1 on migration and invasion of SAS oral cancer cells. Further mechanistic studies revealed an interaction of NANOS1 with the TGF-ß receptor 1 (TGFBR1) mRNA, leading to increased decay of this transcript and a reduced TGFBR1 protein expression, thereby preventing downstream TGF-ß/SMAD signaling. In summary, we identified NANOS1 as negative regulator of TGF-ß signaling in oral cancer cells.

Metabolomics and metagenomics reveal the impact of γδ T inhibition on gut microbiota and metabolism in periodontitis-promoting OSCC

During the process of periodontitis-promoting oral squamous cell carcinoma (OSCC), the periodontitis microbiota can facilitate OSCC development by activating γδ T cells. Inhibiting γδ T cells through immunotherapy has been shown to significantly alleviate various types of cancer. However, the underlying mechanism by which inhibiting γδ T cells influenced cancer treatment has not been fully elucidated. In this study, a mouse model of OSCC with periodontitis was established, and γδ T cells were inhibited by antibodies. Gut samples from the mice were collected and analyzed by metabolomics, metagenomics, and 16S rRNA. Integrative analysis of the gut metabolome and microbiome revealed that targeting γδ T resulted in changes in the levels of metabolites associated with cancer in the gut. Although there was no difference in the α diversity of microbiota, β diversity was significantly different, with a more heterogeneous community structure in the mice receiving targeted γδ T immunotherapy. Statistical analysis of the gut microbiota at the species level revealed a significant enrichment of Lactobacillus murinus, which was significantly correlated with γδ T abundance. The functional analysis revealed that inhibiting γδ T could impact the functional gene. A comprehensive analysis revealed that L. murinus is especially associated with changes in adenine, which also had connection with the concentration of IL-17 and the abundance of γδ T.IMPORTANCEThis study revealed the effect of γδ T cells on gut microbial dysbiosis and identify potential links between gut microbiota and metabolism, providing new insights into the role of γδ T during the process of periodontitis-induced OSCC, and identifying relevant biomarkers for future research and clinical monitoring protocol development.

Ubiquitination, SUMOylation, and NEDDylation related genes serve as prognostic and therapeutic biomarkers for oral squamous cell carcinoma

BACKGROUND

Ubiquitination, small ubiquitin-related modifiers, and NEDDylation are now found to function in cancer biology; however, its role in the oral cancer patients remains unclear.

METHODS

A set of bioinformatic tools was integrated to analyze the expression and prognostic significance of ubiquitin and ubiquitin-like (UB/UBL) genes. A UB/UBL-related risk score was developed via correlation analyses, univariate Cox regression, and multivariate Cox regression. Nomogram analysis evaluates the model's prediction performance. The drug sensitivity analysis, immune profiles of UB/UBL-classified oral squamous cell carcinoma (OSCC) patients, and their related function pathway were investigated, and the role of UB/UBL-related genes in drug therapy was analyzed.

RESULTS

A total of six prognostic UB/UBL-related genes were obtained. PSMD3, PCGF2, and H2BC10 were significantly downregulated in OSCC tissue and associated with longer survival time. OSCC patients in the high-risk group showed a significantly lower overall survival and enriched in cancer-related pathways. The prognostic potential of genes associated with UB/UBL was discovered, and patients with high-risk scores showed an increase of protumor immune infiltrates and a high expression of immune checkpoints. Moreover, the area under the curve of the annual survival rate was 0.616, 0.671, and 0.673, respectively. Besides, patients in the high-risk group are more sensitive to docetaxel, doxorubicin, and methotrexate therapy.

CONCLUSIONS

We construct a prognosis model for OSCC patients with UB/UBL-related genes and try to find a new approach to treating oral cancer patients. The UB/UBL-related signature is helpful in developing new tumor markers, prognostic prediction, and in guiding treatment for OSCC patients.

Impact of tumor subsite on survival outcomes in oral squamous cell carcinoma: A retrospective cohort study from 2000 to 2019

BACKGROUND

Oral squamous cell carcinoma (OSCC) is responsible for high morbidity and mortality worldwide. Although the oral cavity encompasses different anatomical subsites, it is unclear whether subsite localization of carcinoma influences outcome.

METHODS

This retrospective cohort study examined overall survival (OS), recurrence-free survival (RFS) and local recurrence-free survival (L-RFS) at different subsites by Kaplan-Meier survival curves. Cox proportional hazards regression analysis was performed to investigate the impact of subsite on overall death, locoregional recurrence, and local recurrence.

RESULTS

The cohort included 1702 patients treated with curative intent for OSCC according to standardized national guidelines. The 5-year OS was superior in oral tongue to retromolar trigone as well as in both oral tongue and floor-of-mouth (FOM) compared to tumors involving multiple locations. The 3-year RFS in oral tongue and FOM was superior to tumors involving multiple locations, and in FOM compared to retromolar trigone. The 3-year L-RFS in oral tongue and FOM was higher than gingiva, retromolar trigone and tumors involving multiple locations. Adjusting for relevant covariables using oral tongue as reference, tumors involving multiple locations was the only category presenting higher risk for locoregional recurrence, while risk of local recurrence was higher in gingiva, retromolar trigone, hard palate and to tumors involving multiple locations. The study found no difference in risk of death between subsites.

CONCLUSION

The study found differences in survival outcomes between subsites. After adjusting for covariables, subsite mainly had significant impact on local recurrence, with no distinct pattern of influence on overall death or locoregional recurrence.

TLR9 activation induces immunosuppression and tumorigenesis via PARP1/PD-L1 signaling pathway in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer, and metastasis and immunosuppression are responsible for the poor prognosis of OSCC. Previous studies have shown that poly(ADP-ribose) polymerase (PARP)1 plays a key role in the pathogenesis of OSCC. Therefore, PARP1 may serve as an important research target for the potential treatment of OSCC. Here, we aimed to investigate the role of PARP1 in the tumorigenesis of OSCC and elucidate the key molecular mechanisms of its upstream and downstream regulation in vivo and in vitro. In human OSCC tissues and cells, Toll-like receptor (TLR)9 and PD-L1 were highly expressed and PARP1 was lowly expressed. Suppression of TLR9 remarkably repressed CAL27 and SCC9 cell proliferation, migration, and invasion. After coculture, we found that low expression of TLR9 inhibited PD-L1 expression and immune escape. In addition, TLR9 regulated PD-L1 expression through the PARP1/STAT3 pathway. PARP1 mediated the effects of TLR9 on OSCC cell proliferation, migration, and invasion and immune escape. Additionally, in vivo experiments further verified that TLR9 promoted tumor growth and immune escape by inhibiting PARP1. Collectively, TLR9 activation induced immunosuppression and tumorigenesis via PARP1/PD-L1 signaling pathway in OSCC, providing important insights for subsequent in-depth exploration of the mechanism of OSCC.NEW & NOTEWORTHY In this research, we took PARP1 as the key target to explore its regulatory effect on oral squamous cell carcinoma (OSCC). The key molecular mechanisms involved in its upstream and downstream regulation were elucidated in OSCC cell lines in vitro and tumor-bearing mice in vivo, combined with clinical OSCC tissues.

Prognostic effect of programmed cell death ligand 1/programmed cell death 1 expression in cancer stem cells of human oral squamous cell carcinoma

The relationship between cancer stem cells (CSCs) in oral squamous cell carcinoma (OSCC) and programmed cell death ligand 1 (PD-L1)/programmed cell death 1 (PD-1) remains unclear. Therefore, the present study aimed to clarify the association between the CD44v3high/CD24low immunophenotype of CSCs in OSCC and PD-L1/PD-1 co-expression, and to assess the prognostic effect of CSCs in terms of immune checkpoint molecules. Formalin-fixed, paraffin-embedded tissue samples and clinicopathological data from 168 patients with OSCC were retrospectively retrieved. Immunohistochemical staining and reverse transcription quantitative polymerase chain reaction were applied to a tissue microarray of the invasive front of each case. Semi-automated cell counting was used to assess CD44v3, CD24, PD-L1 and PD-1 expression by immunohistochemistry (IHC) using a digital image analysis program. Associations between immunological markers and clinicopathological variables were estimated. Patients with the CSC immunophenotype CD44v3high/CD24low, and patients with a high PD-L1/PD-1-positive cell density in the tumor parenchyma and stroma had significantly lower survival rates. Furthermore, patients with the CSC immunophenotype (CD44v3high/CD24low) and high PD-L1/PD-1 co-expression had even lower survival rates (P<0.01, log-rank test). Notably, there was a positive correlation between CD44v3 and PD-L1 expression (τ=0.1096, P=0.0366, Kendall rank correlation coefficient) and a negative correlation between CD24 and PD-1 expression (τ=-0.1387, P=0.0089, Kendall rank correlation coefficient). Additionally, the high CD44v3 expression group, as determined by IHC, exhibited significantly decreased expression of U2 small nuclear RNA auxiliary factor 1 (U2AF1) at the mRNA level compared with that in the low CD44v3 expression group (P<0.001, Mann-Whitney U test), and U2AF1 and PD-L1 mRNA expression exhibited a significant negative correlation (τ=-0.3948, P<0.001, Kendall rank correlation coefficient). In conclusion, CSCs in OSCC may evade host immune mechanisms and maintain CSC stemness via PD-L1/PD-1 co-expression, resulting in unfavorable clinical outcomes.

Cell fusion between tumor cells and macrophages promotes the metastasis of OSCC patient through the activation of the chemokine signaling pathway

BACKGROUND

Tumor metastasis is responsible for the high mortality rate of patients with oral squamous cell carcinoma (OSCC). Although many hypotheses have been proposed to elucidate the mechanism of tumor metastasis, the origin of the metastatic tumor cells remains unclear. In this study, we explored the role of cell fusion in the formation of OSCC metastatic tumor cells.

METHODS

Murine OSCC tumor cells and macrophages were fused in vitro, and the cell proliferation, migration, and phagocytosis abilities of hybrid cells and parental cells were compared. Subsequently, we compared the transcriptome differences between hybrid and parental cells.

RESULTS

Murine OSCC tumor cells and macrophages were successfully fused in vitro. The cytological and molecular experimental results revealed that OSCC tumor cells obtained a migration-related phenotype after fusion with macrophages, and the migration ability of hybrid cells was related to the activation of the "chemokine signal pathway".

CONCLUSION

After fusion with macrophages, the chemokine signaling pathway in OSCC tumor cells was activated, leading to metastasis.

Nrf2/HO-1 Alleviates Disulfiram/Copper-Induced Ferroptosis in Oral Squamous Cell Carcinoma

Accumulating evidence indicates that the disulfiram/copper complex (DSF/Cu) has been shown to have potent antitumor activity against various cancers. This research evaluated the effects and probable mechanisms of DSF/Cu on oral squamous cell carcinoma (OSCC). In this study, we report the toxicity of the DSF/Cu to OSCC both in vitro and in vivo. Our study showed that DSF/Cu reduced the proliferation and clonogenicity of OSCC cells. DSF/Cu also induced ferroptosis. Importantly, we confirmed that DSF/Cu could increase the free iron pool, enhance lipid peroxidation, and eventually result in ferroptosis cell death. Inhibition of NRF2 or HO-1 enhances the sensitivity of OSCC cells to DSF/Cu-induced ferroptosis. DSF/Cu inhibited the xenograft growth of OSCC cells by suppressing the expression of Nrf2/HO-1. In conclusion, these results provide experimental evidence that Nrf2/HO-1 alleviates DSF/Cu-induced ferroptosis in OSCC. We propose that this therapy could be a novel strategy for treating OSCC.

CaCO3 Nanoparticles Delivering MicroRNA-200c Suppress Oral Squamous Cell Carcinoma

MicroRNA (miR)-200c suppresses the initiation and progression of oral squamous cell carcinoma (OSCC), the most prevalent head and neck cancer with high recurrence, metastasis, and mortality rates. However, miR-200c-based gene therapy to inhibit OSCC growth has yet to be reported. To develop an miR-based gene therapy to improve the outcomes of OSCC treatment, this study investigates the feasibility of plasmid DNA (pDNA) encoding miR-200c delivered via nonviral CaCO3-based nanoparticles to inhibit OSCC tumor growth. CaCO3-based nanoparticles with various ratios of CaCO3 and protamine sulfate (PS) were used to transfect pDNA encoding miR-200c into OSCC cells, and the efficiency of these nanoparticles was evaluated. The proliferation, migration, and associated oncogene production, as well as in vivo tumor growth for OSCC cells overexpressing miR-200c, were also quantified. It was observed that, while CaCO3-based nanoparticles improve transfection efficiencies of pDNA miR-200c, the ratio of CaCO3 to PS significantly influences the transfection efficiency. Overexpression of miR-200c significantly reduced proliferation, migration, and oncogene expression of OSCC cells, as well as the tumor size of cell line-derived xenografts (CDX) in mice. In addition, a local administration of pDNA miR-200c using CaCO3 delivery significantly enhanced miR-200c transfection and suppressed tumor growth of CDX in mice. These results strongly indicate that the nanocomplexes of CaCO3/pDNA miR-200c may potentially be used to reduce oral cancer recurrence and improve clinical outcomes in OSCC treatment, while more comprehensive examinations to confirm the safety and efficacy of the CaCO3/pDNA miR-200c system using various preclinical models are needed.

Prognostic value of 18 F-FDG PET radiomics and sarcopenia in patients with oral squamous cell carcinoma

BACKGROUND

Oral cancer is one of the most common malignancies in the head and neck region. Approximately 90% of oral cancers are oral squamous cell carcinomas (OSCC). 18 F-FDG PET/CT has been used in OSCC patients for its high value in detecting metastatic lymph nodes and distant metastases. PET radiomics and sarcopenia can be measured on the PET and CT components of 18 F-FDG PET/CT.

PURPOSE

This study aimed to investigate the prognostic value of radiomics and sarcopenia measured on the PET and CT components of pre-operation 18 F-FDG PET/CT in OSCC.

METHODS

A total of 116 patients eventually enrolled in our study were randomly divided into two cohorts: training cohort (n = 58) and validation cohort (n = 58). The Cox model combined with the least absolute shrinkage and selection operator (LASSO) algorithm was applied to construct the radiomics score (Rad_score). The third lumber skeletal muscle index (L3 SMI) was calculated to identify sarcopenia. Univariate and multivariate Cox regression analyses were performed to identify the independent prognostic factors. Based on the clinical factors, the clinical model was constructed, and the combined model was developed through the combination of the clinical model and Rad_score. C index, time-dependent C-index curves, receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis were used to evaluate the performance of prediction models.

RESULTS

Three radiomics features constitute the Rad_score for overall survival (OS) and progression-free survival (PFS), respectively. Multivariate Cox regression analysis revealed that Rad_score was an independent prognostic factor, whereas sarcopenia was not. The combined models showed satisfactory performance in both the training cohort (C-index: OS:0.836, PFS:0.776) and the validation cohort (C-index: OS:0.744, PFS:0.712). The combined models were visualized as nomograms. Nomogram scores can realize the risk stratification of OSCC patients. Lower nomogram score is significantly related to the poorer OS (training cohort: p < 0.0001, validation cohort: p < 0.0001, overall cohort: p < 0.0001) and PFS (training cohort: p < 0.0001, validation cohort: p = 0.00017, overall cohort: p < 0.0001).

CONCLUSIONS

Rad_score, but not sarcopenia, was an independent prognostic factor for patients with OSCC. The nomograms had a satisfactory performance, which might be helpful for OSCC patients and clinicians in personalized prognostic prediction and treatment decision-making.

Near-infrared-responsive GE11-CuS@Gal nanoparticles as an intelligent drug release system for targeting therapy against oral squamous cell carcinoma

Galangin (Gal) is a natural plant flavonoid. More and more evidence shows that Gal can achieve anti-tumor effects by regulating various mechanisms. However, its poor water solubility, low bioavailability, and insufficient lesion targeting limit its clinical application. To overcome these shortcomings, we designed and developed a mesoporous nanosystem (GE11-CuS) that actively located the target area and photo-controlled drug release, which promoted the rapid accumulation of drugs in tumor tissues under NIR irradiation, thus achieving positive effects against cancer. In this study, we explored the application of the Gal-loaded nanometer system (GE11-CuS@Gal) in the treatment of oral squamous cell carcinoma (OSCC) both in vitro and in vivo. The results exhibited that GE11-CuS@Gal had excellent targeting ability and could accumulate efficiently in tumor cells (HSC-3). Meanwhile, the temperature of GE11-CuS@Gal increasing rapidly under NIR illumination damaged the integrity of the carrier and allowed Gal molecules to escape from the pores of the nanoparticles. When the accumulation of Gal in the nidus reached a certain level, the intracellular ROS level could be significantly increased and the antioxidative stress pathway mediated by Nrf2/OH-1 was effectively blocked, to inhibit the growth and migration of tumors. In conclusion, the GE11-CuS improved the antitumor activity of Gal in the body, which laid a foundation for the treatment of OSCC with traditional Chinese medicine ingredients.

[Oral squamous cell carcinoma in the background of oral submucous fibrosis - a systematic review]

Oral squamous cell carcinoma (OSCC) in the background of oral submucous fibrosis (OSMF) is one of the most common presentations of oral cancer among Asian population. OSCC arising in the background of OSMF (OSCC with OSMF) has been a topic of interest among researchers recently and a few studies have considered this to be a distinct clinicopathological entity. This systematic review analyses the demographic and clinicopathological variations of OSCC with OSMF from conventional OSCC to evaluate the distinctiveness of OSCC with OSMF. A comprehensive search from PubMed, Google scholar and manual search were carried out and 4 articles were retrieved and analysed systematically. Out of the total 377 OSCC with OSMF cases and 542 conventional OSCC, males were found to be predominantly affected (82.7% and 73.6%). 47% of the OSCC with OSMF cases were well differentiated squamous cell carcinomas as against 33.4% in conventional OSCC. Lymph node metastases were seen predominantly in conventional OSCC (49.1%) than OSCC with OSMF cases (40.7%). OSCC with OSMF were more prevalent in males and showed better tumour differentiation and lesser lymph node metastasis. Even though the present results inculpate OSCC with OSMF as a distinct clinicopathological entity, there is a dire need for thorough investigation.

The role of podoplanin inhibitors in controlling oral cancer progression

OBJECTIVE

In this article, we review the current studies on the role of podoplanin in oral cancer and the potential application of podoplanin inhibitors as a therapeutic agent for oral cancer.

DESIGN

The narrative review approach was conducted, providing a comprehensive perspective of related literature. Publications addressing podoplanin and its inhibitors in the context of oral cancer were retrieved from PubMed and Scopus databases.

RESULTS

Podoplanin has emerged as a biomarker and therapeutic agent for oral cancer. Numerous studies have reported high podoplanin expression in oral cancer and pre-cancerous lesions compared to normal cells. A specific inhibitor targeting podoplanin may have the potential to prevent oral carcinogenesis via interfering with the pathway of cancerous cells involved in cell proliferation and metastasis. Antibodies, chimeric antigen receptor (CAR)-T cells, cancer-specific mAb (CasMab), synthetic molecules, and lectins are among the materials used as anticancer agents targeting podoplanin. Plant-derived lectins appear to demonstrate a unique advantage against alternative candidates.

CONCLUSIONS

The use of podoplanin inhibitors in place of existing therapeutic approaches could be a promising and novel approach to the prevention and treatment of oral cancer. Nevertheless, further research is required to investigate the practical application of such inhibitors.

Usnic acid attenuates 7,12-dimethylbenz[a] anthracene (DMBA) induced oral carcinogenesis through inhibiting oxidative stress, inflammation, and cell proliferation in male golden Syrian hamster model

In this study, we investigated the chemopreventive efficacy of usnic acid (UA), an effective secondary metabolite component of lichens, against 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral squamous cell carcinoma (OSCC) in the hamster model. Initially, the buccal pouch carcinogenesis was induced by administering 0.5% DMBA to the HBP (hamster buccal pouch) region about three times a week until the 10th week. Then, UA was orally treated with different concentrations (25, 50, 100 mg/kg b.wt) on alternative days of DMBA exposure, and the experimental process ended in the 16th week. After animal experimentation, we observed 100% tumor incidence with well-differentiated OSCC, dysplasia, and hyperplasia lesions in the DMBA-induced HBP region. Furthermore, the UA treatment of DMBA-induced hamster effectively inhibited tumor growth. In addition, UA upregulated antioxidant levels, interfered with the elevated lipid peroxidation by-product of thiobarbituric acid reactive substances, and changed the activities of the liver detoxification enzyme (Phase I and II) in DMBA-induced hamsters. Furthermore, immunohistochemical staining of inflammatory markers (iNOS and COX-2) and proliferative cell markers (cyclin-D1 and PCNA) were upregulated in the buccal pouch part of hamster animals induced with DMBA. Notably, the oral administration of UA significantly suppressed these markers during DMBA-induced hamsters. Collectively, our findings revealed that UA exhibits antioxidant, anti-inflammatory, antitumor, and apoptosis-inducing characteristics, demonstrating UA's protective properties against DMBA-induced HBP carcinogenesis.

Transcriptomic Profiling of OSCC Patients in an Indian Subset

BACKGROUND

Tumor-specific biomarkers are needed for accomplishing antidote in early detection, as well as prognosis and designing therapeutic strategies. Comprehensive transcriptome profiling offers critical insights into the disease and reveal new avenue for drug discovery.

METHODS

Total 5 cancerous and histopathological normal tissue pairs of 5 OSCC patients included in the petite study. Transcriptome sequencing was performed using Roche's 454 sequencing platform followed by CLC Genomics Workbench was used to examine gene expression in OC development.

RESULTS

A total 2082 genes were differentially expressed across all the five tumor-control pairs collected from the OC patients during the surgery. From these 1092 upregulated and 273 downregulated genes, whereas 717 genes were found to be non-significant. The genes with pvalue <0.05 and log2foldchange > 1 or log2foldchange < -1 were considered for further enrichment analysis. Topfunn was used for gene enrichment analysis to identify gene enrichment pathway analysis found some cancer related pathways such as TNF signaling, p53 signaling pathway, cGMP-PKG signaling pathway, Apelin signaling pathway and IL-17 signaling pathway were strikingly involved in proliferation and apoptosis of tumor cells. The PPI network construction was performed and identified 8 best protein interactions.

CONCLUSION

The current study reports molecular biomarkers including INHBA, FJX1, OLR1, CDK2, IGHM, CXCL11, SH2D5 and FABP5 associated with cancer that can led to identify potential therapeutic targets for the better prognosis of the cancer patients. The signature candidate can be translated to clinical practice to increase early diagnostic accuracy.

Wound healing after therapy of oral potentially malignant disorders with a 445-nm semiconductor laser: a randomized clinical trial

OBJECTIVES

Oral potentially malignant disorders (OPMDs) are the most clinically relevant precursor lesions of the oral squamous cell carcinoma (OSCC). OSCC is one of the 15 most common cancers worldwide. OSCC is with its high rate of mortality an important cause of death worldwide. The diagnosis and therapy of clinically relevant precursor lesions of the OSCC is one of the main parts of prevention of this malignant disease. Targeted therapy is one of the main challenges concerning an oncologically safe tissue removal without overwhelming functional and aesthetic impairment.

MATERIALS AND METHODS

In this randomized controlled trial, a newly introduced intraoral 445-nm semiconductor laser (2W; cw-mode; SIROLaser Blue, Dentsply Sirona, Bensheim, Germany) was used in the therapy of OPMDs. Duration and course of wound healing, pain, and scar tissue formation were compared to classical cold blade removal with primary suture by measuring remaining wound area, tissue colorimetry, and visual analogue scale. The study includes 40 patients randomized using a random spreadsheet sequence in two groups (n1 = 20; n2 = 20).

RESULTS

This comparative analysis revealed a significantly reduced remaining wound area after 1, 2, and 4 weeks in the laser group compared to the cold blade group (p < 0.05). In the laser group, a significantly reduced postoperative pain after 1 week was measured (p < 0.05).

CONCLUSION

Laser coagulation of OPMDs with the investigated 445-nm semiconductor laser is a safe, gentle, and predictable surgical procedure with beneficial wound healing and reduced postoperative discomfort.

CLINICAL RELEVANCE

Compared to the more invasive and bloody cold blade removal with scalpel, the 445-nm semiconductor laser could be a new functional less traumatic tool in the therapy of OPMDs. The method should be further investigated with regard to the identification of further possible indications.

TRAIL REGISTRATION

German Clinical Trials Register No: DRKS00032626.

Synergetic impact of combined navoximod with cisplatin mitigates chemo-immune resistance via blockading IDO1+ CAFs-secreted Kyn/AhR/IL-6 and pol ζ-prevented CIN in human oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most prevalent aggressive form of HNSC and treated with platinum-based chemotherapy as initial therapy. However, the development of acquired resistance and neurotoxicity to platinum agents poses a significant challenge to treat locally advanced OSCC. Notably, IDO1+ CAFs could promote immunosuppressive TME for OSCC progression. Therefore, we developed a potent IDO1 inhibitor navoximod to overcome chemo-immune resistance via an antitumor immune effect synergized with cisplatin in SCC-9 co-cultured IDO1+/IDO1- CAFs and SCC-7/IDO1+ CAFs-inoculated mice. The in vitro biological assays on IDO1+ CAFs co-cultured OSCC cancer cells supported that combined navoximod with cisplatin could mitigate chemo-immune resistance through blockading IDO1+ CAFs-secreted kynurenine (Kyn)-aryl hydrocarbon receptor (AhR)-IL-6 via suppressing p-STAT3/NF-κB signals and ceasing AhR-induced loss of pol ζ-caused chromosomal instability (CIN). Moreover, the combination elicited antitumor immunity via reducing IDO1+ CAFs-secreted Kyn/AhR and conferring pol ζ in SCC-7/IDO1+ CAFs-inoculated BALB/c mice. Meanwhile, the combination could block cisplatin-induced neurotoxicity and not interfere with chemotherapy. Taken together, the study investigated the promising therapeutic potential of combined navoximod with cisplatin to mitigate tumoral immune resistance via alleviating IDO1+ CAFs-secreted immune-suppression and CIN-caused cisplatin resistance, providing a paradigm for combined chemo-immunotherapy to prolong survival in patients with OSCC.

Does surgery affect systemic immune response? a perioperative analysis of TGF-β, IL-8 and CD45RO

Background

The options of (neo-)adjuvant immunotherapy in addition to surgery in the treatment of oral squamous cell carcinoma (OSCC) are steadily increasing, but patients do not always respond to therapy as intended. The objectives of this study were to investigate the systemic perioperative course of the biomarkers CD45RO, TGF-β, and IL-8 in non-tumor-related minor and tumor-related major maxillofacial surgery and to perform association analyses with demographic and histomorphologic parameters. A deeper understanding of surgery-related changes in various of different immune biomarkers could help to better understand the immunologic consequences of surgery which could influence immunotherapeutic protocols.

Methods

Peripheral whole blood from 38 patients was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR) at five different timepoints before and after maxillofacial surgery to detect changes in mRNA expression of the biomarkers TGF-β, IL-8 and CD45RO. All patients underwent general anesthesia to undergo either resection and free flap reconstruction for OSCC or minor maxillofacial surgery (controls). Statistical analysis was done using Mann-Whitney-U test, Wilcoxon test, and Spearman's correlation.

Results

Compared to the preoperative expression, there was a significant postoperative downregulation of CD45RO, TGF-β and IL-8 until the 4th postoperative day (p ≤ 0.003) in OSCC patients. For TGF-β and IL-8, the reduction in expression was significant (p ≤ 0.004) compared to controls. By postoperative day 10, all analyzed parameters converged to baseline levels. Only CD45RO still showed a significant downregulation (p=0.024). Spearman analysis revealed a significant correlation between increased duration of surgery and perioperative reduction in peripheral blood expression of CD45RO, TGF-β and IL-8 (p ≤ 0.004). Perioperative changes in TGF-β and PD-L1 expression were shown to be not correlated. Preoperative TGF-β expression was significantly lower in patients with lymph node metastases (p=0.014).

Conclusion

With regard to the analyzed parameters, major oncologic head-and-neck surgery does not seem to have long-lasting systemic immunologic effects. Reduced CD45RO might be an expression of transient systemic immunosuppression in response to major surgery. The association of duration of surgery with expression changes of immunologic markers supports efforts to keep the duration of surgery as short as possible. As perioperative TGF-β and PD-L1 expression changes are not associated, these results support further investigation of a combined perioperative anti-PD-1 and anti-TGF-β immunotherapy.