Aberrant Expression Of PDCD4/eIF4A1 Signal Predicts Postoperative Recurrence For Early-Stage Oral Squamous Cell Carcinoma

Annexin A5 is a novel prognostic biomarker in oral squamous cell carcinoma

BACKGROUND

ANXA5, a notable tumor marker, displays irregular expression in diverse solid cancers, and links to local recurrence and metastasis rates. We aimed study the expression of ANXA5 in oral squamous cell carcinoma (OSCC) and its diagnostic and prognostic values.

METHODS

520 head and neck squamous cell carcinoma (HNSCC) patients in TCGA database and 124 OSCC patients in Nanjing stomatology hospital were enrolled in our study. Immunohistochemical analyses were performed using ANXA5 antibodies. Chi-square test was used to analyze the clinicopathological features. Survival rates were determined using the Kaplan-Meier method and log-rank test.

RESULTS

Our results showed significantly elevated ANXA5 at the gene and protein levels in HNSCC and OSCC compared to non-tumor tissues. Histopathologically, ANXA5 was broadly present in OSCC tumor cells and fibroblast-like cells but absent in tumor-infiltrating lymphocytes, particularly at the invasive tumor front. Patients exhibiting high ANXA5 expression in these cells demonstrated poor differentiation, aggressive invasion patterns, and heightened lymph node metastasis risk, contributing to poorer postoperative outcomes. Remarkably, ANXA5 in fibroblast-like cells emerged as an independent risk factor impacting survival in OSCC patients. Gene set enrichment analysis (GSEA) highlighted ANXA5's involvement in key pathways like epithelial-mesenchymal transformation (EMT), TGF-beta signaling, and hypoxia, which correlated with adverse clinical outcomes in OSCC.

CONCLUSION

ANXA5 emerges as a significant prognostic biomarker for OSCC, potentially influencing its metastasis via the EMT pathway.

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.

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.

Eukaryotic translation initiation factor 4A1 in the pathogenesis and treatment of cancers

Abnormal translate regulation is an important phenomenon in cancer initiation and progression. Eukaryotic translation initiation factor 4A1 (eIF4A1) protein is an ATP-dependent Ribonucleic Acid (RNA) helicase, which is essential for translation and has bidirectional RNA unwinders function. In this review, we discuss the levels of expression, regulatory mechanisms and protein functions of eIF4A1 in different human tumors. eIF4A1 is often involved as a target of microRNAs or long non-coding RNAs during the epithelial-mesenchymal transition, associating with the proliferation and metastasis of tumor cells. eIF4A1 protein exhibits the promising biomarker for rapid diagnosis of pre-cancer lesions, histological phenotypes, clinical staging diagnosis and outcome prediction, which provides a novel strategy for precise medical care and target therapy for patients with tumors at the same time, relevant small molecule inhibitors have also been applied in clinical practice, providing reliable theoretical support and clinical basis for the development of this gene target.

ICOSLG-associated immunological landscape and diagnostic value in oral squamous cell carcinoma: a prospective cohort study

Background: We previously reported that stroma cells regulate constitutive and inductive PD-L1 (B7-H1) expression and immune escape of oral squamous cell carcinoma. ICOSLG (B7-H2), belongs to the B7 protein family, also participates in regulating T cells activation for tissue homeostasis via binding to ICOS and inducing ICOS+ T cell differentiation as well as stimulate B-cell activation, while it appears to be abnormally expressed during carcinogenesis. Clarifying its heterogeneous clinical expression pattern and its immune landscape is a prerequisite for the maximum response rate of ICOSLG-based immunotherapy in a specific population. Methods: This retrospective study included OSCC tissue samples (n = 105) to analyze the spatial distribution of ICOSLG. Preoperative peripheral blood samples (n = 104) and independent tissue samples (n = 10) of OSCC were collected to analyze the changes of immunocytes (T cells, B cells, NK cells and macrophages) according to ICOSLG level in different cellular contents. Results: ICOSLG is ubiquitous in tumor cells (TCs), cancer-associated fibroblasts (CAFs) and tumor infiltrating lymphocytes (TILs). Patients with high ICOSLGTCs or TILs showed high TNM stage and lymph node metastasis, which predicted a decreased overall or metastasis-free survival. This sub-cohort was featured with diminished CD4+ T cells and increased Foxp3+ cells in invasive Frontier in situ, and increased absolute numbers of CD3+CD4+ and CD8+ T cells in peripheral blood. ICOSLG also positively correlated with other immune checkpoint molecules (PD-L1, CSF1R, CTLA4, IDO1, IL10, PD1). Conclusion: Tumor cell-derived ICOSLG could be an efficient marker of OSCC patient stratification for precision immunotherapy.

High expression of eIF4A1 predicts unfavorable prognosis in clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is a worldwide malignancy with high morbidity and mortality. Translation initiation factor 4A1 (eIF4A1), which is an ATP-dependent RNA helicase as a part of eIF4F complex, has been linked to malignant transformation and progression, and a variety of cancers display dysregulation of this enzyme. However, its role in ccRCC remains unclear. In our study, we examined its potential effects in ccRCC.

METHODS

Based on Proteomic data, TCGA and ONCOMINE database, RCC cell lines and tissues, the expression of eIF4A1 between ccRCC and normal tissues were investigated. A correlation was evaluated between the prognostic model for OS and ccRCC progression. Analysis of functional enrichment and PPI network were performed. After examining differentially expressed genes between the eIF4A1 high and low-expression groups, we performed GSEA analysis. Furthermore, we investigated immune cell infiltration of eIF4A1. Then we determined eIF4A1 functions in the establishment and maintenance of cell viability, migration and invasion of cell lines. Flow cytometry was utilized to detect cell cycle.

RESULTS

The eIF4A1 was up-regulated in ccRCC tissues and cell lines. An increased level of eIF4A1 was linked to lower survival rates and impaired immunity. Depletion of eIF4A1 could arrest tumor cells in G1 phase, so as to seriously limit cell proliferation and weaken the capacity of cell migration.

CONCLUSION

ccRCC patients with high eIF4A1 expression are at increased risk of poor prognosis, furthermore eIF4A1 plays a prominent role in facilitating tumor cell proliferation and migration which may further be a potential prognostic biomarker and therapeutic target.

Lipid Droplet-Related PLIN2 in CD68+ Tumor-Associated Macrophage of Oral Squamous Cell Carcinoma: Implications for Cancer Prognosis and Immunotherapy

Background

PLIN2 (adipose differentiation-related protein) belongs to the perilipin family and is a marker of lipid droplets (LDs). Numerous types of tumor exhibit a high PLIN2 level, but its tumorigenic or tumor-suppressive role has been in debate. Recently, LDs serve as innate immune hubs and show antimicrobial capacity. We here aimed to investigate the heterogeneous functions of PLIN2 in the tumor microenvironment and immune regulation.

Methods

This retrospective study included 96 oral squamous cell carcinoma (OSCC) samples and analyzed the spatial distribution of PLIN2 by immunohistochemistry (IHC) and LD level by oil red O staining. A total of 21 serial sections were obtained to analyze the relationship between PLIN2 and immune cells by IHC and immunofluorescence (IF). Single-cell sequencing was used to analyze the cell locations of PLIN2. The values of diagnosis and prognosis of PLIN2 were also evaluated. Tumor Immune Estimation Resource (TIMER), cBioPortal databases, and IHC analysis were used to investigate the relationship between PLIN2 and OSCC immune microenvironment.

Results

PLIN2 was mainly expressed in tumor-infiltrating immunocytes (TIIs) of OSCC. Patients with high PLIN2 harbored more cytoplastic LDs. CD68⁺ tumor-associated macrophages (TAMs), instead of T cells and B cells, were found to be the main resource of PLIN2 in OSCC stroma and lung, pancreas, prostate, and testis. However, CD56⁺ NK cells also showed less extent of PLIN2 staining in OSCC. Moreover, patients with a high PLIN2 level in immune cells had a higher TNM stage and were susceptible to postoperative metastasis, but the escalated PLIN2 level in invasive tumor front independently predicted shorter metastasis-free survival. Furthermore, a high PLIN2 presentation in the microenvironment induced immune suppression which was featured as less infiltration of CD8⁺ T cells and more CD68⁺ TAMs and Foxp3⁺ Tregs, accompanied by more immune checkpoint molecules such as CSF1R, LGALS9, IL-10, CTLA-4, and TIGIT.

Conclusion

CD68⁺ TAM-derived PLIN2 might participate in regulating immune balance of OSCC patients, which provides new insight into immune checkpoint therapy.

Hematoporphyrin monomethyl ether mediated photodynamic therapy inhibits oral squamous cell carcinoma by regulating the P53-miR-21-PDCD4 axis via singlet oxygen

The objective of this study was to determine the mechanism and effect of hematoporphyrin monomethyl ether mediated photodynamic therapy (HMME-PDT) on oral squamous cell carcinoma (OSCC). Human OSCC CAL-27 cells were randomly divided into four groups: control group, HMME group, laser group, and HMME-PDT group. Cell viability was detected by the CCK-8 method. Cell cycle distribution was evaluated by flow cytometry. GEO database was used to screen differentially expressed microRNAs (DEMs), and TCGA database was performed to verify DEM expression in OSCC and normal tissues. The effects of HMME-PDT on DEM expression were assayed by real-time PCR, and the expressions of miRNAs target genes were measured by western blot. Fluorescence probes were used to determine the production of singlet oxygen (¹O₂). Compared with the other three groups, HMME-PDT dramatically inhibited CAL-27 cell proliferation and induced G0/G1 cycle arrest. The expressions of miR-21 and miR-155 were significantly upregulated in OSCC. HMME-PDT downregulated the expression of miR-21 but had no obvious effect on miR-155. HMME-PDT remarkably upregulated the levels of P53 and miR-21 target proteins, such as PDCD4, RECK, and SPRY2. ¹O₂ was generated during HMME-PDT, and inhibition of ¹O₂ production could reverse the regulation of HMME-PDT on P53, miR-21, and its target proteins, thus restoring cell viability. HMME-PDT can significantly inhibit the growth of OSCC cells, and the mechanism of this effect is related to the regulation of the P53-miR-21-PDCD4 axis via ¹O₂ induced by HMME-PDT.

Expression and Functional Roles of Eukaryotic Initiation Factor 4A Family Proteins in Human Cancers

The dysregulation of mRNA translation is common in malignancies and may lead to tumorigenesis and progression. Eukaryotic initiation factor 4A (eIF4A) proteins are essential for translation, exhibit bidirectional RNA helicase function, and act as RNA-dependent ATPases. In this review, we explored the predicted structures of the three eIF4A isoforms (eIF4A1, eIF4A2, and eIF4A3), and discussed possible explanations for which function during different translation stages (initiation, mRNA localization, export, and mRNA splicing). These proteins also frequently served as targets of microRNAs (miRNAs) or long noncoding RNAs (lncRNAs) to mediate epithelial-mesenchymal transition (EMT), which was associated with tumor cell invasion and metastasis. To define the differential expression of eIF4A family members, we applied the Tumor Immune Estimation Resource website. We figured out that the eIF4A family genes were differently expressed in specific cancer types. We also found that the level of the eIF4A family genes were associated with abundant immune cells infiltration and tumor purity. The associations between eIF4A proteins and cancer patient clinicopathological features suggested that eIF4A proteins might serve as biomarkers for early tumor diagnosis, histological classification, and clinical grading/staging, providing new tools for precise and individualized cancer treatment.

Identification and Validation of PLOD2 as an Adverse Prognostic Biomarker for Oral Squamous Cell Carcinoma

Background: Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2), a key enzyme that catalyzes the hydroxylation of lysine, plays a crucial role in the progression of several solid tumors. However, its spatial expression profile and prognostic significance in oral squamous cell carcinoma (OSCC) have not been revealed. Materials: Mass spectrometry was used to explore amino acid perturbations between OSCC tumor tissues and paired normal tissues of 28 patients. Then, PLOD2 mRNA and protein levels were assessed using several public databases and 18 pairs of OSCC patients’ tissues. Additionally, PLOD2 spatial expression profiles were investigated in 100 OSCC patients by immunohistochemistry and its diagnostic and prognostic values were also evaluated. Lastly, gene set enrichment analysis (GSEA) was used to investigate the potential functions of PLOD2 in OSCC. Results: Lysine was significantly elevated in OSCC tissues and could effectively distinguish tumor from normal tissues (AUC = 0.859, p = 0.0035). PLOD2 mRNA and protein levels were highly increased in tumor tissues of head and neck squamous cell carcinoma (HNSCC) (p < 0.001) and OSCC compared with those in nontumor tissues (p < 0.001). Histopathologically, PLOD2 was ubiquitously expressed in tumor cells (TCs) and fibroblast-like cells (FLCs) of OSCC patients but absent in tumor-infiltrating lymphocytes (TILs). Patients with highly expressed PLOD2 in TCs (PLOD2^TCs) and FLCs (PLOD2^FLCs) showed poor differentiation, a worse pattern of invasion (WPOI) and more lymph node metastasis (LNM), contributing to higher postoperative metastasis risk and poor survival time. However, PLOD2^FLCs rather than PLOD2^TCs was an independent risk factor for survival outcomes in OSCC patients. Molecularly, GSEA demonstrated highly expressed PLOD2 was mainly enriched in epithelial–mesenchymal transformation (EMT), TGF-beta signaling and hypoxia pathway, which are associated with poor clinical outcomes of OSCC patients. Conclusions: PLOD2 was a poor prognostic biomarker for OSCC patients and may affect the metastasis of OSCC through EMT pathway. These findings might shed novel sights for future research in PLOD2 targeted OSCC therapy.

The Hidden Treasures of Preoperative Blood Assessment in Oral Cancer: A Potential Source of Biomarkers

Simple Summary

In this study, we assess the prognostic potential of immune and inflammatory elements determined preoperatively in the peripheral blood of patients with oral squamous cell carcinoma (OSCC). Preoperative plasma fibrinogen (Fib) and platelet-to-lymphocyte ratio (PLR) show strong correlations with patients’ outcomes. Analyzed together, in a new parameter named Fibrinogen-PLR Algorithm (FiPLA), predictive power increases significantly. Clinicians can use this new, easy, cost-effective, and globally available tool for risk stratification of patients with OSCC, as early as from the moment of diagnosis.

Abstract

(1) Background: Oral squamous cell carcinoma (OSCC) is a common malignancy, and the impact of immune and inflammatory mechanisms in its development and progression are of major interest. The aim of our study is to assess the prognostic potential of circulating immune and inflammatory elements determined preoperatively in patients with OSCC, as well as the development of a new compound parameter with predictive value. (2) Methods: We assessed preoperative fibrinogen (Fib) and the platelet-to-lymphocyte ratio (PLR) in 111 OSCC patients. Using a mathematic algorithm, we determined a composite parameter with cumulative information from Fib and PLR, named Fibrinogen-PLR Algorithm (FiPLA). Survival analysis, followed by bivariate and multivariate analyses, was subsequently conducted. (3) Results: Increased preoperative Fib and PLR levels were associated with poor outcome in OSCC (p = 0.0001 and p = 0.0015, respectively). Preoperative FiPLA values were also associated with poor patient survival (p < 0.0001). Multivariate analysis confirmed the independent prognostic role for FiPLA only (CI95% 1.232–67.770, p = 0.03), showing the superior predictive value of FiPLA compared to its individual components. (4) Conclusions: Preoperative assessments of circulating immune and inflammatory elements can provide high-quality prognostic information, and they represent valuable tools in clinical practice, facilitating the early risk stratification of patients with OSCC.

CD38 Multi-Functionality in Oral Squamous Cell Carcinoma: Prognostic Implications, Immune Balance, and Immune Checkpoint

Background

CD38 belongs to the ribosyl cyclase family and is expressed on various hematological cells and involved in immunosuppression and tumor promotion. Although targeting CD38 antibodies has been approved for treatment of multiple myeloma, the function of CD38 in solid tumor, oral squamous cell carcinoma (OSCC) etc., has not been investigated.

Methods

This retrospective study included 92 OSCC samples and analyzed the spatial distribution of CD38 by immunohistochemistry (IHC). The values of diagnosis and prognosis of CD38 were evaluated. Additionally, 53 OSCC preoperative peripheral blood samples were used to be analyzed by flow cytometry. Tumor Immune Estimation Resource (TIMER) and cBioPortal databases were used to study CD38 level in various tumors and its correlation with tumor immune microenvironment in head and neck squamous cell carcinoma (HNSCC).

Results

CD38 ubiquitously presented in tumor cells (TCs), fibroblast-like cells (FLCs), and tumor-infiltrating lymphocytes (TILs). Patients with highly expressed CD38 in TCs (CD38^TCs) had higher TNM stage and risk of lymph node metastasis. Upregulation of CD38 in FLCs (CD38^FLCs) was significantly associated with poor WPOI. Escalated CD38 in TILs (CD38^TILs) led to higher Ki-67 level of tumor cells. Moreover, patients with enhanced CD38^TCs were susceptible to postoperative metastasis occurrence, and those with highly expressed CD38^TILs independently predicted shorter overall and disease-free survival. Strikingly, patients with highly expressed CD38^TILs, but not CD38^TCs and CD38^FLCs, had significantly lower CD3⁺CD4⁺ T cells and higher ratio of CD3^-CD16⁺CD56⁺NK cells. The imbalance of immune system is attributed to dysregulated immune checkpoint molecules (VISTA, PD-1, LAG-3, CTLA-4, TIGIT, GITR) as well as particular immune cell subsets, which were positively correlated with CD38 expression in HNSCC.

Conclusion

CD38 is a poor prognostic biomarker for OSCC patients and plays a vital role in governing immune microenvironment and circulating lymphocyte homeostasis. Co-expression between CD38 and immune checkpoint molecules provides new insight into immune checkpoint therapy.