Contemporary Approach to Locally Advanced Oral Cavity Squamous Cell Carcinoma

METTL3-Mediated Maturation of miR-99a-5p Promotes Cell Migration and Invasion in Oral Squamous Cell Carcinoma by Targeting ZBTB7A

METTL3 is an important methyltransferase in N(6)-methyladenosine (m6A) modification. Recently, METTL3 mediates methylation of pri-microRNA (miRNA) to accelerate miRNA maturation, regulating tumor development. This study explored whether METTL3 mediated miR-99a-5p to influence oral squamous cell carcinoma (OSCC) cell metastasis. MiR-99a-5p, ZBTB7A, and MATTL3 expression was measured using quantitative real-time PCR. Biological behaviors were assessed using cell counting kit-8, flow cytometry, Transwell assay, as well as western blot. Luciferase reporter assay evaluated the interaction between miR-99a-5p and ZBTB7A. METTL3-regulated pri-miR-99a-5p processing was determined by RNA binding protein immunoprecipitation (RIP) and methylated RNA immunoprecipitation (MeRIP) assays. The consequences clarified that miR-99a-5p was upregulated in OSCC cells. Downregulation of miR-99a-5p suppressed cellular viability, migration, invasion, and epithelial-mesenchymal transition (EMT), and induced apoptosis. ZBTB7A acted as a miR-99a-5p target and reversed the effects on cellular behaviors induced by miR-99a-5p inhibitor. m6A content and METTL3 expression were increased in OSCC cells. METTL3 promoted the m6A modification of pri-miR-99a-5p and thereby facilitated miR-99a-5p processing. Moreover, knockdown of METTL3 inhibited OSCC metastasis by downregulating miR-99a-5p. Taken together, METTL3 promoted miR-99a-5p maturation in an m6A-dependent manner, which further targets ZBTB7A to accelerate the progression of OSCC. These findings suggest potential targets for OSCC therapy.

Management and outcome of locally advanced oral squamous cell carcinoma

Management of locally advanced OSCC is multimodal. No single therapy has been proved to be efficacious. However there is a trend towards surgical intervention in operable disease. In this review we appraise the various therapies used for the management of locally advanced OSCC. We review the literature with regards to the various treatment options for locally advanced OSCC. We categorically divided the manuscript into resectable, unresectable and technically unresectable disease. Surgery is the ideal treatment modality for resectable disease. For unresectable disease concurrent chemoradiation appears to improve survival compared to radiotherapy alone. Induction therapy might downstage tumors in the unresectable category. Targeted and Immunotherapy is reserved for recurrent, metastatic or platinum refractory OSCC. Management of locally advanced OSCC is multimodal with surgery playing the primary role. In the event where the tumor is in operable concurrent chemoradiotherapy is regarded as the best treatment modality. Induction chemotherapy currently cannot be recommended for resectable or even unresectable oral squamous cell carcinomas. However for technically unresectable disease it might play a role in improving respectability but it depends on the response of the tumor. Targeted therapy and immunotherapy is currently used for recurrent, metastatic and/or platinum refractory Head and Neck cancers. Currently it is not recommended for initial management of locally advanced disease.

Hsa_circ_0005050 regulated the progression of oral squamous cell carcinoma via miR-487a-3p/CHSY1 axis

Background/purpose

Circular RNAs (circRNAs) have been identified as potential functional modulators of the cellular physiology processes. This study aims to learn the potential molecular mechanisms of hsa_circ_0005050 (circ_0005050) in oral squamous cell carcinoma (OSCC).

Materials and methods

Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to examine the expression of circ_0005050, miR-487a-3p, and chondroitin sulfate synthase 1 (CHSY1). Dual-luciferase reporter system, RNA pull-down, and RNA Immunoprecipitation (RIP) assays were used to determine the binding between miR-487a-3p and circ_0005050 or CHSY1. Colony formation experiment and EdU assay were used to investigate proliferation. Wound-healing and transwell assays were used to detect the migration of cells. The apoptosis rate of OSCC cells was tested by flow cytometry. Protein levels of related factors were determined by Western blot. Tumor xenograft was established to determine the regulatory role of circ_0005050 on tumor growth in vivo, and Ki-67 expression was detected in this xenograft using Immunohistochemical (IHC).

Results

We implicated that circ_0005050 was apparently upregulated in OSCC tissues cells. In function experiments, repressing of circ_0005050 remarkably retarded OSCC growth in vitro. Furthermore, we conducted dual-luciferase reporter assays and RNA pull-down assays to verify that circ_0005050 sponged miR-487a-3p. Suppression of miR-487a-3p rescued the inhibition of proliferation in SCC15 and SCC25 cells induced by circ_0005050 knockdown. In addition, we found that overexpression of CHSY1 also reversed the inhibitory effect of circ_0005050 silencing on cell proliferation. Moreover, circ_0005050 knockdown inhibited tumor growth in vivo.

Conclusion

Circ_0005050 acted as an oncogenic factor in OSCC progression through miR-487a-3p/CHSY1 axis.

Risk Stratification in Oral Cancer: A Novel Approach

Background

Oral squamous cell carcinoma (OSCC) is a common head and neck cancer with high morbidity and mortality. Currently, treatment decisions are guided by TNM staging, which omits important negative prognosticators such as lymphovascular invasion, perineural invasion (PNI), and histologic differentiation. We proposed nomogram models based on adverse pathological features to identify candidates suitable for treatment escalation within each risk group according to the National Comprehensive Cancer Network (NCCN) guidelines.

Methods

Anonymized clinicopathologic data of OSCC patients from 5 tertiary healthcare institutions in Asia were divided into 3 risk groups according to the NCCN guidelines. Within each risk group, nomograms were built to predict overall survival based on histologic differentiation, histologic margin involvement, depth of invasion (DOI), extranodal extension, PNI, lymphovascular, and bone invasion. Nomograms were internally validated with precision–recall analysis and the Kaplan–Meier survival analysis.

Results

Low-risk patients with positive pathological nodal involvement and/or positive PNI should be considered for adjuvant radiotherapy. Intermediate-risk patients with gross bone invasion may benefit from concurrent chemotherapy. High-risk patients with positive margins, high DOI, and a high composite score of histologic differentiation, PNI, and the American Joint Committee on Cancer (AJCC) 8th edition T staging should be considered for treatment escalation to experimental therapies in clinical trials.

Conclusion

Nomograms built based on prognostic adverse pathological features can be used within each NCCN risk group to fine-tune treatment decisions for OSCC patients.

CircZDBF2 up-regulates RNF145 by ceRNA model and recruits CEBPB to accelerate oral squamous cell carcinoma progression via NFκB signaling pathway

Background

Oral squamous cell carcinoma (OSCC), as one of the commonest malignancies showing poor prognosis, has been increasingly suggested to be modulated by circular RNAs (circRNAs). Through GEO (Gene Expression Omnibus) database, a circRNA derived from ZDBF2 (circZDBF2) was uncovered to be with high expression in OSCC tissues, while how it may function in OSCC remains unclear.

Methods

CircZDBF2 expression was firstly verified in OSCC cells via qRT-PCR. CCK-8, along with colony formation, wound healing, transwell and western blot assays was performed to assess the malignant cell behaviors in OSCC cells. Further, RNA pull down assay, RIP assay, as well as luciferase reporter assay was performed to testify the interaction between circZDBF2 and RNAs.

Results

CircZDBF2 expressed at a high level in OSCC cells and it accelerated OSCC cell proliferation, migration, invasion as well as EMT (epithelial-mesenchymal transition) process. Further, circZDBF2 sponged miR-362-5p and miR-500b-5p in OSCC cells to release their target ring finger protein 145 (RNF145). RNF145 expressed at a high level in OSCC cells and circZDBF2 facilitated RNF145 transcription by recruiting the transcription factor CCAAT enhancer binding protein beta (CEBPB). Moreover, RNF145 activated NFκB (nuclear factor kappa B) signaling pathway and regulated IL-8 (C-X-C motif chemokine ligand 8) transcription.

Conclusion

CircZDBF2 up-regulated RNF145 expression by sponging miR-362-5p and miR-500b-5p and recruiting CEBPB, thereby promoting OSCC progression via NFκB signaling pathway. The findings recommend circZDBF2 as a probable therapeutic target for OSCC.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03347-1.

Anlotinib Suppresses Oral Squamous Cell Carcinoma Growth and Metastasis by Targeting the RAS Protein to Inhibit the PI3K/Akt Signalling Pathway

Oral squamous cell carcinoma (OSCC) is a malignant tumour originating from the mucosal lining of the oral cavity. Its characteristics include hidden onset, high recurrence, and distant metastasis after operation. At present, clinical treatment usually includes surgery, chemotherapy, radiotherapy, or the joint use of these modalities. Unfortunately, multidrug resistant is one of the important obstacles that causes cancer chemotherapy failure. Anlotinib, which has recently been proven to have good antitumour effects, is a novel multitargeted tyrosine kinase inhibitor. However, there are few studies of the anlotinib-associated mechanism in OSCC and its underlying molecular mechanism. In our study, in vitro models of human oral squamous cell carcinoma HSC-3 cells were used to determine the efficacy of anlotinib. On the one hand, we showed that anlotinib treatment significantly reduced the viability and proliferation of HSC-3 cells and decreased cell migration by inhibiting the activation of the Akt phosphorylation pathway. On the other side, anlotinib inhibited PI3K/Akt/Bad phosphorylation and promoted apoptosis of HSC-3 cells by activating RAS protein expression. In brief, these results indicated that anlotinib had prominent antitumour activity in OSCC, mainly by inhibiting the PI3K/Akt phosphorylation pathway. This work provides evidences and a basic principle for using anlotinib to treat patients with OSCC for clinical research.

Advanced Lung Cancer Inflammation Index Predicts Survival Outcomes of Patients With Oral Cavity Cancer Following Curative Surgery

Aim

The aim of our study was to investigate the prognostic value of preoperative advanced lung cancer inflammation index (ALI) and to establish prognostic nomograms for the prediction of survival outcomes in patients with oral cavity squamous cell carcinoma (OSCC).

Materials and Methods

A total of 372 patients who received primary curative surgery for OSCC during 2008–2017 at a tertiary referral center were enrolled. We used the receiver operating characteristic curve to determine the optimal cutoff point of ALI. Through a Cox proportional hazards model and Kaplan–Meier analysis, we elucidated the ALI–overall survival (OS) and ALI–disease-free survival (DFS) associations. Prognostic nomograms based on ALI and the results of multivariate analysis were created to predict the OS and DFS. We used the concordance indices (C-indices) and calibration plots to assess the discriminatory and predictive ability.

Results

The results revealed that the ALI cutoff was 33.6, and 105 and 267 patients had ALI values of <33.6 and ≥33.6, respectively. ALI < 33.6 significantly indicated lower OS (44.0% vs. 80.1%, p < 0.001) and DFS (33.6% vs. 62.8%; p < 0.001). In multivariate analysis, ALI < 33.6 was independently associated with poor OS and DFS (both p < 0.001). The C-indices of established nomograms were 0.773 and 0.674 for OS and DFS, respectively; moreover, the calibration plots revealed good consistency between nomogram-predicted and actual observed OS and DFS.

Conclusion

ALI is a promising prognostic biomarker in patients undergoing primary surgery for OSCC; moreover, ALI-based nomograms may be a useful prognostic tool for individualized OS and DFS estimations.

miR-29a-3p enhances the radiosensitivity of oral squamous cell carcinoma cells by inhibiting ADAM12

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor in the head and neck, and radiotherapy is the main approach for this disease, while irradiation resistance is a huge challenge that influences radiosensitivity. This study aims to determine the role and function of miR-29a-3p and ADAM12 in the radiosensitivity of OSCC cells. The expression pattern of ADAM12 in OSCC cells was searched in TCGA database. The binding of miR-29a-3p and ADAM12 was predicted by Starbase and verified using dual luciferase reporter gene assay. The RNA or protein expressions of miR-29a-3p and ADAM12 were measured by RT-qPCR or western blot. OSCC cell lines were treated by various γ-ray irradiation dosages before the alteration on miR-29a-3p expression and on the cell viability, proliferation, migration and cell apoptosis was detected. ADAM12 was highly expressed in OSCC cells, whose expression in resistant cells was positively correlated with irradiation dosage. Overexpression of ADAM12 in OSCC cells lead to increased cell proliferation and migration ability as well as inhibited cell apoptosis. miRNAs potentially binding ADAM12 in PITA, microT, miRmap and targetscan were screened, among which miR-29a-3p had the maximum differential expression levels in OSCC cells determined by RT-qPCR. Overexpression of miR-29a-3p resulted in suppressed cell viability, proliferation, migration ability and increased cell apoptosis, while this expression pattern can be partially counteracted by ADAM12 overexpression in OSCC cells. miR-29a-3p through targeting and inhibiting AMDM12 enhances the radiosensitivity of OSCC cells.

Oral Squamous Cell Carcinoma Bone Invasion: Possible Roles of E-Cadherin in Osteoclastogenesis and Bone Infiltration

INTRODUCTION

Squamous cell carcinoma is the most common cancer of the oral cavity. When the tumor invades the bone tissue, the prognostic and survival rates decrease a lot, and the treatment becomes more aggressive, with several damages to the patient and health system. Many of the molecular mechanisms of bone invasion process are not understood yet, but it is already known that one of central processes of tumor evolution - adjacent tissues invasion and metastasis - is a large spectrum of phenotypic changes in epithelial cells to mesenchymal, in a process named as epithelial-mesenchymal transition (EMT). Loss of E-cadherin, an important epithelial cell adhesion protein, is a hallmark of this phenomenon. The objective of this retrospective study is to evaluate the expression of E-cadherin protein, comparing its distribution with clinical characteristics of the patients and possibly relation to EMT.

METHODS

Sixty-two cases with respective clinical data were analyzed by comparing immunohistochemical, H and E staining, and clinical data, observing the tumor-bone interface (TBI) and the surrounding tumor that had no direct contact with the bone surface (ST).

RESULTS

Forty cases were positive for E-cadherin (64%) with a heterogeneous pattern. Statistical analysis showed a significant difference between the presence of E-cadherin expression and tobacco smokers. Also, the equal or weaker protein expression in the ST than TBI is related to a worse overall survival. No statistically significant difference in other prognostic factors was observed.

CONCLUSION

Our results suggest that the tumor cells that interact with the bone tissue could gain molecular changes, like partial EMT and osteoclastogenesis induction, which facilitate their migration and increase the bone resorption, resulting in a worse patient's prognosis.

Promotion of ubiquitination-dependent survivin destruction contributes to xanthohumol-mediated tumor suppression and overcomes radioresistance in human oral squamous cell carcinoma

Background

Overexpression of survivin plays a crucial role in tumorigenesis and correlates with poor prognosis in human malignancies. Thus, survivin has been proposed as an attractive target for new anti-tumor interventions.

Methods

A natural product library was used for natural compound screening through MTS assay. The expression of survivin in oral squamous cell carcinoma (OSCC) and the inhibitory effect of xanthohumol (XN) on OSCC were examined by anchorage-dependent and -independent growth assays, immunoblot, immunofluorescence, immunohistochemical staining, ubiquitination analysis, co-immunoprecipitation assay, CRISPR-Cas9-based gene knockout, and xenograft experiment.

Results

Survivin is highly expressed in OSCC patient-derived tissues and cell lines. Knockout of survivin reduced the tumorigenic properties of OSCC cells in vitro and in vivo. With a natural compound screening, we identified that xanthohumol inhibited OSCC cells by reducing survivin protein level and activating mitochondrial apoptotic signaling. Xanthohumol inhibited the Akt-Wee1-CDK1 signaling, which in turn decreased survivin phosphorylation on Thr34, and facilitated E3 ligase Fbxl7-mediated survivin ubiquitination and degradation. Xanthohumol alone or in combination with radiation overcame radioresistance in OSCC xenograft tumors.

Conclusion

Our findings indicate that targeting survivin for degradation might a promising strategy for OSCC treatment.