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.

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.

Advanced progress of spatial metabolomics in head and neck cancer research.

Head and neck cancer ranks as the sixth most prevalent malignancy, constituting 5 % of all cancer cases. Its inconspicuous onset often leads to advanced stage diagnoses, prompting the need for early detection to enhance patient prognosis. Currently, research into early diagnostic markers relies predominantly on genomics, proteomics, transcriptomics, and other methods, which, unfortunately, necessitate tumor tissue homogenization, resulting in the loss of temporal and spatial information. Emerging as a recent addition to the omics toolkit, spatial metabolomics stands out. This method conducts in situ mass spectrometry analyses on fresh tissue specimens while effectively preserving their spatiotemporal information. The utilization of spatial metabolomics in life science research offers distinct advantages. This article comprehensively reviews the progress of spatial metabolomics in head and neck cancer research, encompassing insights into cancer cell metabolic reprogramming. Various mass spectrometry imaging techniques, such as secondary ion mass spectrometry, stroma-assisted laser desorption/ionization, and desorption electrospray ionization, enable in situ metabolite analysis for head and neck cancer. Finally, significant emphasis is placed on the application of presently available techniques for early diagnosis, margin assessment, and prognosis of head and neck cancer.

[An analysis of the wall width before and after root canal therapy in mandibular second molars with C-shaped canals].

PURPOSE: To measure the wall width in mandibular second molars with C-shaped canals before and after root canal therapy using cone-beam CT(CBCT). METHODS: A total of 55 mandibular second molars from 38 patients which met the criteria for inclusion at Nanjing Stomatological Hospital, Affiliated Stomatological Hospital of Medical School of Nanjing University from January 2020 to July 2021 were analyzed．From this sample, ten teeth had been treated, while another 45 of them not. CT images of the teeth were reestablished by Mimics software 20.0. Then we made a section every 1mm perpendicular to the long axis of the teeth from apex to pulp floor. The first slice from apex to pulp chamber was named the slice 1. Along the slice 1 to crown 1 mm was called slice 1, and so forth. The wall thickness at different locations of all the slices was measured. The data was entered into SPSS 20.0 software package for analysis. RESULTS: Regardless of whether the teeth were treated or not, both the mesial and distal canal walls' average width were thicker than 1mm in all slices. At the same time, the mesial and distal canal walls' width were thicker than the width of buccal and lingual canal walls in all the slices from C-shaped root canal, except slices which were near pulp chamber(P＜0.05). As for the C-shaped root canals without root canal therapy, the width of lingual wall in the slice 1 to 4, as well as apex third root, was thinner than 1 mm. The width of buccal canal wall was thicker than the width of lingual canal wall in all slices except slice 11 and 12. As for the C-shaped root canals with root canal therapy, the width of buccal canal wall in slice 1 to 5, equivalent of apex half root, and the width of lingual wall in the slice 1 to 7, amount to apex two-thirds of root, was thinner than 1 mm. The width of buccal canal wall was thicker than the width of lingual wall in all slices except slice 1 and 9. There was no significant difference between the distal canal walls' width of C-shaped canals with and without root canal therapy(P＞0.05) . There was significant difference between the buccal canal walls' width of C-shaped canals with and without root canal therapy, as same as the mesial canal walls' width and the width of lingual canal wall (P＜0.05). CONCLUSIONS: The lingual canal walls' width in apex third root of C-shaped root canal were thin before canal preparation. The buccal walls' width in apex half root and the lingual canal walls' in apex two-thirds of root of C-shaped root canal were thin after canal preparation.

Oral tongue squamous cell carcinoma diagnosis from tissue metabolic profiling.

OBJECTIVE: Disease metabolomes have been studied for identifying diagnostic and predictive biomarkers of pathology. Oral tongue squamous cell carcinoma (OTSCC) is one of the most prevalent subtypes of head and neck squamous cell carcinoma, yet the profile and diagnostic value of its tissue metabolite are unclear. SUBJECTS AND METHODS: Tumor tissue samples and matched normal mucosal tissue samples were collected from 40 OTSCC patients. Untargeted metabolic analysis by liquid chromatography-mass spectrometry/mass spectrometry, in positive and negative ion modes, was used to identify dysregulated metabolites in OTSCC. Further, utilizing LASSO regression and receiver operating characteristic analyses, biomarker metabolites were selected and validated, and a diagnostic model was established. RESULTS: One hundred and ninety metabolites were detected. The OTSCC had a total of 89 dysregulated metabolites, of which 73 were elevated. A diagnostic panel of nine metabolites was subsequently created that could accurately identify OTSCC with 100% sensitivity of 100%, 100% specificity and an AUC of 1.00. CONCLUSIONS: This study identified distinct metabolic characteristics of OTSCC and established a diagnostic model. Our research also contributes to the investigation of the pathogenesis of OTSCC.

Lactobacillus gasseri LG08 and Leuconostoc mesenteroides LM58 exert preventive effect on the development of hyperuricemia by repairing antioxidant system and intestinal flora balance.

Introduction: Currently, hyperuricemia has shown a surprisingly rising trend, which attracts widespread attention due to potentially major health risks. Considering the inevitable side effects of long-term medicine, probiotics are emerging as potential therapeutics due to their ability to improve uric acid metabolism and superior safety. Methods: In our study, two strains of probiotics, Lactobacillus gasseri LG08 (LG08) and Leuconostoc mesenteroides LM58 (LM58) isolated from kimchi were evaluated for the prebiotic properties in vitro and uric-lowering effects in vivo. Here, hyperuricemia animal model and 16S rRNA gene amplicons analysis were further studied to investigate whether these probiotics exert different effects in prevention and treatment. Results: In vivo indicators and intestinal flora immunity revealed that both LG08 and LM58 significantly prevent the development and progression of hyperuricemia, repair the antioxidant system and maintain intestinal flora balance in healthy rats, especially LM58. After hyperuricemia was formed, although the effect of LG08 and LM58 could decrease the level of uric acid, the effect to reverse and repair antioxidant levels in the body was limited. Discussion: In our study, these findings have important implications for hyperuricemia prevention and therapy, and provided more mechanistic insights into the effect of probiotics in hyperuricemia.

Multiperspective quantitative tumor-stroma ratio reveals histological areas associated with poor outcomes in oral squamous cell carcinoma.

AIMS: Different regions of oral squamous cell carcinoma (OSCC) have particular histopathological characteristics, and the individual histological characteristics of the tumors are poorly understood. Therefore, calculating the proportion of tumor cells in different regions that allow assessment of the prognostic outcomes for OSCC patients would be of great clinical significance. METHODS AND RESULTS: We established an open-source software-based analytic pipeline that defines the inner tumor and invasive tumor front (ITF) in pancytokeratin-stained whole slide images (WSIs) and quantifies the tumor-stroma ratio (TSR) within the two regions. We applied this method to 114 patients with OSCC and predicted patient prognosis by the TSR. The proportion of tumor area in the inner tumor was generally higher than that in the ITF (p < 0.0001). TSR was an independent prognostic factor for overall survival (OS) (p = 0.016), disease-free survival (DFS) (p = 0.026), and relapse-free survival (RFS) (p = 0.037) in inner tumor, and TSR was an independent prognostic factor for OS (p = 0.00052), DFS (p = 0.035), and metastasis-free survival (MFS) (p = 0.038) in the ITF. Tumor-low status was associated with poorer prognosis. There was a significant correlation between the TSR and perineural invasion (PNI) in the inner tumor (p = 0.009). CONCLUSIONS: The histopathological characteristics of different regions of OSCC may be used to develop the potential prognostic markers. The TSR of the inner tumor is more targeted in predicting prognosis and accurately assesses the risk of PNI+.

The feasibility of discriminating BRONJ lesion bone with Raman spectroscopy.

Background: With the frequent use of Bisphosphonates (BPs), the morbidity of BP-related osteonecrosis of the jaw (BRONJ) is also increasing. However, the prevention and treatment of BRONJ is faced with enormous challenges. This study aimed to illuminate the influence of BP administration in the rat mandible and explore the feasibility of discriminating BRONJ lesion bone with Raman spectroscopy. Materials and methods: First, we explored the time- and mode-dependent effects of BP administration on the rat mandible with Raman spectroscopy. Second, the BRONJ rat model was constructed, and the lesion and healthy bone components were analyzed using Raman spectroscopy. Results: When only BPs were administered, no rats showed BRONJ symptoms, and no difference could be found in the Raman spectra. However, when combined with local surgery, six (6/8) rats showed BRONJ symptoms. The Raman spectra also showed a significant difference between the lesion and healthy bone. Conclusion: In the progression of BRONJ, BPs and local stimulation play an essential role. Both BPs administration and local stimulation need to be controlled to prevent BRONJ. Moreover, BRONJ lesion bone in rats could be discriminated with Raman spectroscopy. This novel method would become a complement in the treatment of BRONJ in the future.

IL-33/ST2 signaling promotes constitutive and inductive PD-L1 expression and immune escape in oral squamous cell carcinoma.

BACKGROUND: Loss-of-function of PD-L1 induces therapy resistance of anti-PD-1/L1 therapy, and the complex regulatory mechanisms are not completely understood. We previously reported that stroma-derived interleukin-33 (IL-33) promoted the progression of oral squamous cell carcinoma (OSCC). We here focused on the immune-regulation role of IL-33 and its receptor ST2 signaling in PD-L1-positive OSCC patients. METHODS: Activated T cells in in situ and peripheral blood were analyzed by IL-33/ST3 expression. Knockdown or overexpression of ST2 combined with IL-33/IFN-γ stimulation were performed to determine PD-L1 expression and PD-L1-dependent immune escape in OSCC/human T cells co-culture system, and OSCC orthotopic model based on humanized mouse with immune reconstitution and C57BL/6 mice models. RESULTS: High IL-33/ST2 correlated with less activated T cells infiltration in situ and peripheral blood. Knockdown of ST2 down-regulated constitutive PD-L1 expression, whereas ST2 also promoted IL-33-induced PD-L1 Mechanistically, IL-33/ST2 activated JAK2/STAT3 pathway to directly promoted PD-L1 expression, and also activated MyD88/NF-κB signaling to up-regulate IFN-γ receptor (IFN-γR), which indirectly strengthen IFN-γ-induced PD-L1. Furthermore, ST2 is required for PD-L1-mediated immune tolerance in vitro and in vivo. ST2high OSCC patients have more PD-L1 and IFN-γR level in situ. CONCLUSIONS: IL-33/ST2 signaling enhanced PD-L1-mediated immune escape, ST2high OSCC patients might benefit from anti-PD-1/L1 therapy.

A metagenome-wide association study of the gut microbiota in recurrent aphthous ulcer and regulation by thalidomide.

Recurrent aphthous ulcer (RAU), one of the most common diseases in humans, has an unknown etiology and is difficult to treat. Thalidomide is an important immunomodulatory and antitumor drug and its effects on the gut microbiota still remain unclear. We conducted a metagenomic sequencing study of fecal samples from a cohort of individuals with RAU, performed biochemical assays of cytokines, immunoglobulins and antimicrobial peptides in serum and saliva, and investigated the regulation effects of thalidomide administration and withdrawal. Meanwhile we constructed the corresponding prediction models. Our metagenome-wide association results indicated that gut dysbacteriosis, microbial dysfunction and immune imbalance occurred in RAU patients. Thalidomide regulated gut dysbacteriosis in a species-specific manner and had different sustainable effects on various probiotics and pathogens. A previously unknown association between gut microbiota alterations and RAU was found, and the specific roles of thalidomide in modulating the gut microbiota and immunity were determined, suggesting that RAU may be affected by targeting gut dysbacteriosis and modifying immune imbalance. In-depth insights into sophisticated networks consisting of the gut microbiota and host cells may lead to the development of emerging treatments, including prebiotics, probiotics, synbiotics, and postbiotics.

Identification of Biological Functions and Prognostic Value of NNMT in Oral Squamous Cell Carcinoma.

BACKGROUND: Nicotinamide N-methyltransferase (NNMT) is a metabolic enzyme that catalyzes the methylation of nicotinamide (NAM) to generate 1-methyl nicotinamide (MNAM). Although previous studies have shown that NNMT is frequently dysregulated to promote the onset and progression of many malignancies, its expression profile, prognostic value and function in oral squamous cell carcinoma (OSCC) are still unknown. METHODS: We used untargeted metabolomics based on mass spectrometry to analyze potential metabolite differences between tumors and matched adjacent normal tissues in 40 OSCC patients. Immunohistochemistry (IHC) was used to analyze the NNMT expression profile in OSCC, and the diagnostic and prognostic values of NNMT were evaluated. Next, qPCR and Western blot were used to compare the expression of NNMT in five OSCC cell lines. Stable transfected cell lines were constructed, and functional experiments were carried out to elucidate the effects of NNMT on the proliferation and migration of OSCC cells. Finally, gene set enrichment analysis (GSEA) was performed using The Cancer Genome Atlas (TCGA) data to investigate the potential functional mechanisms of NNMT in OSCC. RESULTS: We found that the nicotinamide metabolic pathway was abnormally activated in OSCC tumor tissues compared with normal tissues. NNMT was expressed ubiquitously in tumor cells (TCs) and fibroblast-like cells (FLCs) but was absent in tumor-infiltrating lymphocytes (TILs). OSCC patients with highly expressed NNMT in TCs had higher risk of lymph node metastasis and showed a worse pattern of invasion (POI). Moreover, patients with highly expressed NNMT were also susceptible to postoperative recurrence. Highly expressed NNMT can independently predict shorter disease-free survival and recurrence-free survival. Functionally, we demonstrated that the ectopic expression of NNMT promoted OSCC tumor cell proliferation and migration in vitro. Conversely, silencing exerted significantly opposite effects in vitro. In addition, GSEA showed that highly expressed NNMT was mainly enriched in the epithelial-mesenchymal transformation (EMT) pathway, which displayed a significant positive correlation with the six classic EMT markers. CONCLUSIONS: Our study uncovered that NNMT may be a critical regulator of EMT in OSCC and may serve as a prognostic biomarker for OSCC patients. These findings might provide novel insights for future research in NNMT-targeted OSCC metastasis and recurrence therapy.

Impact of preanalytical freezing delay time on the stability of metabolites in oral squamous cell carcinoma tissue samples.

INTRODUCTION: Metabolite stability is critical for tissue metabolomics. However, changes in metabolites in tissues over time from the operating room to the laboratory remain underexplored. OBJECTIVES: In this study, we evaluated the effect of postoperative freezing delay time on the stability of metabolites in normal and oral squamous cell carcinoma (OSCC) tissues. METHODS: Tumor and paired normal tissues from five OSCC patients were collected after surgical resection, and samples was sequentially quenched in liquid nitrogen at 30, 40, 50, 60, 70, 80, 90 and 120 min (80 samples). Untargeted metabolic analysis by liquid chromatography-mass spectrometry/mass spectrometry in positive and negative ion modes was used to identify metabolic changes associated with delayed freezing time. The trends of metabolite changes at 30-120 and 30-60 min of delayed freezing were analyzed. RESULTS: 190 metabolites in 36 chemical classes were detected. After delayed freezing for 120 min, approximately 20% of the metabolites changed significantly in normal and tumor tissues, and differences in the metabolites were found in normal and tumor tissues. After a delay of 60 min, 29 metabolites had changed significantly in normal tissues, and 84 metabolites had changed significantly in tumor tissues. In addition, we constructed three tissue freezing schemes based on the observed variation trends in the metabolites. CONCLUSION: Delayed freezing of tissue samples has a certain impact on the stability of metabolites. For metabolites with significant changes, we suggest that the freezing time of tissues be reasonably selected according to the freezing schemes and the actual clinical situation.

OXTRHigh stroma fibroblasts control the invasion pattern of oral squamous cell carcinoma via ERK5 signaling.

The Pattern Of Invasion (POI) of tumor cells into adjacent normal tissues clinically predicts postoperative tumor metastasis/recurrence of early oral squamous cell carcinoma (OSCC), but the mechanisms underlying the development of these subtypes remain unclear. Focusing on the highest score of POIs (Worst POI, WPOI) present within each tumor, we observe a disease progression-driven shift of WPOI towards the high-risk type 4/5, associated with a mesenchymal phenotype in advanced OSCC. WPOI 4-5-derived cancer-associated fibroblasts (CAFsWPOI4-5), characterized by high oxytocin receptor expression (OXTRHigh), contribute to local-regional metastasis. OXTRHigh CAFs induce a desmoplastic stroma and CCL26 is required for the invasive phenotype of CCR3+ tumors. Mechanistically, OXTR activates nuclear ERK5 transcription signaling via Gαq and CDC37 to maintain high levels of OXTR and CCL26. ERK5 ablation reprograms the pro-invasive phenotype of OXTRHigh CAFs. Therefore, targeting ERK5 signaling in OXTRHigh CAFs is a potential therapeutic strategy for OSCC patients with WPOI 4-5.

Corrigendum: Experimental Periodontitis Deteriorated Atherosclerosis Associated With Trimethylamine N-Oxide Metabolism in Mice.

[This corrects the article DOI: 10.3389/fcimb.2021.820535.].

Identification of Metabolism-Associated Biomarkers for Early and Precise Diagnosis of Oral Squamous Cell Carcinoma.

The 5-year survival rate for oral squamous cell carcinoma (OSCC), one of the most common head and neck cancers, has not improved in the last 20 years. Poor prognosis of OSCC is the result of failure in early and precise diagnosis. Metabolic reprogramming, including the alteration of the uptake and utilisation of glucose, amino acids and lipids, is an important feature of OSCC and can be used to identify its biomarkers for early and precise diagnosis. In this review, we summarise how recent findings of rewired metabolic networks in OSCC have facilitated early and precise diagnosis of OSCC.

Clinical application of indocyanine green fluorescence navigation technology to determine the safe margin of advanced oral squamous cell carcinoma.

Background: Advanced oral squamous cell carcinoma (OSCC) has large lesions and deep infiltration, and the control of safe surgical margins was difficult. If residual tumor remains after incomplete tumor resection, it can lead to local tumor recurrence or even distant metastasis. This study sought to investigate the clinical application of indocyanine green (ICG)-based near-infrared fluorescence (NIF) molecular imaging in the intraoperative detection of surgical margins of advanced OSCC. Methods: Twenty-nine patients with advanced OSCC treated at the First Ward of Oral and Maxillofacial Surgery, Nanjing Stomatological Hospital were divided into the ICG group and non-ICG group. In the ICG group, the tumors were removed with the assistance of ICG fluorescence navigation technology. In the non-ICG group, the tumors were removed with conventional methods, and the cutting-edge tissues of the two groups underwent frozen biopsies. The margin abnormality rates were calculated and compared. Results: Under the excitation of NIF in the ICG group, tumor fluorescence development was observable in all lesions, and the tumor boundary was clear. The abnormal rates of the incisional margin in the ICG group and non-ICG group were 0.78% and 6.25%, respectively (P<0.05). Conclusions: ICG-mediated NIF imaging technology provides a new method for observing and completely resecting tumors under direct vision during operation, and finding residual tumors at the cutting edge in time. These results will inform the treatment of advanced OSCC.

Worst Pattern of Perineural Invasion Redefines the Spatial Localization of Nerves in Oral Squamous Cell Carcinoma.

As a key histopathological characteristic of tumor invasion, perineural invasion (PNI) assists tumor dissemination, whereas the current definition of PNI by dichotomy is not accurate and the prognostic value of PNI has not reached consensus. To define PNI status in each patient when mixed types of PNI occurred simultaneously, we here further subclassified the traditional PNI in 183 patients with oral squamous cell carcinoma (OSCC). The spatial localization of nerves in OSCC microenvironment was thoroughly evaluated and successfully concluded into four types of PNI: 0, tumor cells away from nerves; 1, tumor cells encircling nerves less than 33%; 2, tumor cells encircling nerves at least 33%; and 3, tumor cells infiltrating into nerve sheathes. Sequentially, patients were stratified by single and mixed types of PNI. Traditionally, types 0 and 1 were defined as PNI-, while types 2 and 3 were PNI+, which predicted shorter survival time. When multiple types of PNI existed within one tumor, patients with higher score of PNI types tended to have a relatively worse prognosis. Therefore, to define the status of PNI more precisely, the new variable worst pattern of PNI (WPNI) was proposed, which was taken as the highest score of PNI types present in each patient no matter how focal. Results showed that patients with WPNI 1 had longest survival time, and WPNI 2 correlated with better overall survival (p = 0.02), local-regional recurrence-free survival (p = 0.03), and distant metastasis-free survival (p = 0.046) than WPNI 3. Multivariate Cox analysis confirmed that only WPNI 3 could independently predict patients' prognosis, which could be explained by a more damaged immune response in WPNI 3 patients with less CD3+CD8+ T cells and CD19+ B cells. Conclusively, WPNI by trichotomy provide more meticulous and precise pathological information for tumor-nerve interactions in OSCC patients.

Active Smoking Induces Aberrations in Digestive Tract Microbiota of Rats.

Cigarette smoking could have certain effects on gut microbiota. Some pioneering studies have investigated effects of active smoking on the microbiome in local segments of the digestive tract, while active smoking-induced microbiome alterations in the whole digestive tract have not been fully investigated. Here, we developed a rat model of active smoking and characterized the effects of active smoking on the microbiota within multiple regions along the digestive tract. Blood glucose and some metabolic factors levels, the microbial diversity and composition, relative abundances of taxa, bacterial network correlations and predictive functional profiles were compared between the control group and active smoking group. We found that active smoking induced hyperglycemia and significant reductions in serum insulin and leptin levels. Active smoking induced region-specific shifts in microbiota structure, composition, network correlation and metabolism function along the digestive tract. Our results demonstrated that active smoking resulted in a reduced abundance of some potentially beneficial genera (i.e. Clostridium, Turicibacter) and increased abundance of potentially harmful genera (i.e. Desulfovibrio, Bilophila). Functional prediction suggested that amino acid, lipid, propanoate metabolism function could be impaired and antioxidant activity may be triggered. Active smoking may be an overlooked risk to health through its potential effects on the digestive tract microbiota, which is involved in the cause and severity of an array of chronic diseases.

Accurately Locating Metastatic Foci in Lymph Nodes With Lugol's Iodine-Enhanced Micro-CT Imaging.

BACKGROUND: Accurate evaluation of lymph node (LN) status is the key factor to determine the treatment and evaluate prognosis for patients with cancer. However, traditional pathological examination resulted in a 30% false-negative rate of detection of metastases in LNs. This study aimed to utilize Lugol's iodine (I2-IK)-enhanced micro-CT imaging to reveal the 3-dimensional structure of regional LNs and decrease the false-negative rate in pathological examination. METHODS: To explore the feasibility of I2-IK-enhanced micro-CT imaging in locating metastatic lesion in LNs, nonmetastatic and metastatic LNs from mice were used to mimic the imaging process. Then, the LNs from oral squamous cell carcinoma (OSCC) patients were applied to verify the value of I2-IK-enhanced micro-CT imaging in revealing LN structure and locating metastatic lesions in LNs. The glycogen content in nonmetastatic and metastatic LNs was further detected by the use of a glycogen assay kit and periodic acid-Schiff (PAS) staining to explain the imaging differences between them. RESULTS: In nude mice, 0.5% I2-IK staining for 4 h was the best parameter for normal LN. The metastatic foci in metastatic LNs were also clearly outlined in this condition. For nonmetastatic LNs from patients with OSCC, 1% I2-IK staining for 12 h was the best parameter. However, due to the increased volume of metastatic LNs, the image effect of 3% I2-IK staining for 12 h was superior to 1% I2-IK staining [tumor background ratio (TBR), 3% vs. 1%, 1.89 ± 0.10 vs. 1.27 ± 0.07, p < 0.001]. Compared with subsequent pathological sections, we found the CT intensity of metastatic foci in LNs and muscle tissues was significantly higher than in nonmetastatic regions. Meanwhile, the glycogen content of metastatic foci in LNs detected was also significantly higher than in nonmetastatic region. CONCLUSIONS: I2-IK-enhanced micro-CT imaging could identify the spatial location of metastatic foci in LNs. This will be an effective method to assist in decreasing the LN false-negative rate for cancer pathology.