Definitive (chemo)radiotherapy is a curative alternative for standard of care in advanced stage squamous cell carcinoma of the oral cavity

Induction chemotherapy with paclitaxel, carboplatin, and cetuximab (PCE) followed by chemoradiotherapy for unresectable locoregional recurrence after curative surgery in patients with squamous cell carcinoma of the head and neck

Background

The significance of induction chemotherapy (IC) in the treatment of squamous cell carcinoma of the head and neck (SCCHN) with unresectable locoregional recurrence after curative surgery has not been clarified. The aim of this study was to evaluate the efficacy of IC followed by chemoradiotherapy (CRT) in these patients.

Methods

Among patients with unresectable locoregional recurrent SCCHN who had not undergone prior irradiation and were eligible for cisplatin, we conducted a retrospective analysis of patients who received CRT following IC with paclitaxel, carboplatin, or cetuximab (IC-PCE group) and those who received CRT without prior IC (CRT group) between June 2013 and August 2021.

Result

Forty-two patients were included. The CRT group and IC-PCE group consisted of 15 and 27 patients, respectively. Primary site was the oral cavity (n=25), oropharynx (n=3), hypopharynx (n=13) and larynx (n=1). Objective response rate (ORR) with IC-PCE was 55.6%; 24 patients (88.9%) subsequently received CRT. ORR after completion of CRT was significantly better in the IC-PCE group (95.8% in the IC-PCE group vs. 66.7% in the CRT group, p=0.024). Progression-free survival (PFS) of the total population on median follow-up of 2.4 years (range: 0.8-7.3) tended to be better in the IC-PCE group (2-year PFS: 55.6% in the IC-PCE group vs. 33.3% in the CRT group, log-rank p=0.176), especially in oral cancer (2-year PFS: 37.5% in the IC-PCE group vs. 0% in the CRT group, log-rank p=0.015).

Conclusion

Therapeutic strategies including IC-PCE in patients with unresectable locoregional recurrent SCCHN after curative surgery may contribute to improved prognosis, especially in oral cancer.

SP2-induced circPUM1 modulates chemoresistance and nature killer cell toxicity in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a type of tumour found in the cavity that is characterized by differentiation and metastasis to the lymph nodes. Although diagnosis strategy and clinical treatment have recently improved, the outcomes for OSCC patients remain unsatisfactory. This study verified the characteristics of circPUM1 in OSCC cells, subsequently generating dysregulated circPUM1 cell models, showing that circPUM1 promoted chemoresistance and natural killer (NK) cell toxicity. Furthermore, the transcription factor SP2 regulated the expression of circPUM1 in OSCC cells, circPUM1 acted as a molecular sponge for miR-770-5p. Moreover, Nucleosome Assembly Protein 1 Like 1 (NAP1L1) is a downstream target for miR-770-5p and essential for circPUM1-mediated cisplatin resistance and NK cell cytotoxicity in OSCC cells. The network composed of SP2, circPUM1, miR-770-5p and NAP1L1 in OSCC appears to be a promising avenue for the development of novel targets for diagnosing or treating OSCC.

Comprehensive Characterization of Immune Landscape Based on Tumor Microenvironment for Oral Squamous Cell Carcinoma Prognosis

Objective: This study aims to identify an immune-related signature to predict clinical outcomes of oral squamous cell carcinoma (OSCC) patients. Methods: Gene transcriptome data of both tumor and normal tissues from OSCC and the corresponding clinical information were downloaded from The Cancer Genome Atlas (TCGA). Tumor Immune Estimation Resource algorithm (ESTIMATE) was used to calculate the immune/stromal-related scores. The immune/stromal scores and associated clinical characteristics of OSCC patients were evaluated. Univariate Cox proportional hazards regression analyses, least absolute shrinkage, and selection operator (LASSO) and receiver operating characteristic (ROC) curve analyses were performed to assess the prognostic prediction capacity. Gene Set Enrichment Analysis (GSEA) and Gene Ontology (GO) function annotation were used to analysis the functions of TME-related genes. Results: Eleven predictor genes were identified in the immune-related signature and overall survival (OS) in the high-risk group was significantly shorter than in the low-risk group. An ROC analysis showed the TME-related signature could predict the total OS of OSCC patients. Moreover, GSEA and GO function annotation proved that immunity and immune-related pathways were mainly enriched in the high-risk group. Conclusions: We identified an immune-related signature that was closely correlated with the prognosis and immune response of OSCC patients. This signature may have important implications for improving the clinical survival rate of OSCC patients and provide a potential strategy for cancer immunotherapy.

Incidence and prognostic significance of extranodal extension in isolated nodal recurrence of oral squamous cell carcinoma

BACKGROUND

Extranodal extension (ENE) is a crucial prognostic factor of oral squamous cell carcinoma (OSCC). However, the role of ENE in regional recurrence (rENE) remains unclear. The purpose of our study is to assess the salvage outcome according to the presence of rENE in oral cancer patients with isolated nodal recurrence.

METHODS

Oral cancer patients diagnosed with isolated nodal recurrence at the National Taiwan University Hospital between January 2010 and December 2015 were reviewed. All patients were classified into two groups: with and without rENE. The treatment included salvage neck dissection (ND) ± metronomic chemotherapy, salvage ND and radiation (RT)/concurrent chemoradiation (CCRT), Salvage RT/CCRT alone, metronomic chemotherapy, or supportive care.

RESULTS

We analyzed 198 patients, 156 with rENE and 42 without rENE. rENE presented more frequently in patients with initial ENE+ (OR = 3.17, p = 0.04), prior RT+ (OR = 2.96, p = 0.02), initial N2/N3 (OR = 2.76, p = 0.01), and recurrent LN size >1.5 cm (OR = 2.33, p = 0.03). The extent of rENE were also significantly different in these patients. The 2-year disease-free survival for patients with and without rENE were 15.7% and 31.7%, respectively (p = 0.002). The 2-year overall survival for patients with and without rENE were 19.6% and 43.9%, respectively (p = 0.004). For patients without rENE, those received salvage ND had better survival outcome (p < 0.001). By contrast, for patients with rENE, those received salvage RT/CCRT had better survival outcome (p < 0.001).

CONCLUSION

The rENE is frequently present (78.79%) in OSCC patients with isolated nodal recurrence. Individualized treatment modalities based on the presence of rENE should be recommended to achieve better salvage outcomes.

Therapeutic Options in Unresectable Oral Squamous Cell Carcinoma: A Systematic Review

Purpose

This review describes the current scientific evidence of therapeutic options in unresectable oral squamous cell carcinoma.

Methods

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We searched MEDLINE (Via PubMed) to identify studies assessing treatments for unresectable oral squamous cell carcinoma. The methodological quality assessment of the included studies was performed using the Joanna Briggs Institute (JBI) checklist tool. The evidence was organized and presented using tables and narrative synthesis.

Results

Thirty-three studies met the eligibility criteria. Most studies had an observational design. The sample size varied from 16 to 916 participants. The methodology quality of the included studies ranged from 2.5 to 10 using the JBI tool. Overall, the optimal treatment of patients with unresectable oral cancer is challenging, so there is a sprinkling of studies assessing a variety of therapeutic options, such as radiotherapy, chemotherapy, concurrent chemoradiotherapy, immunotherapy, targeted therapy plus chemotherapy or radiotherapy, and gene therapy plus chemotherapy.

Conclusion

There is lacking evidence about the benefits of some therapeutic options for unresectable oral squamous cell carcinoma. Overall, these patients can be treated using a multimodal approach such as concurrent chemoradiotherapy or induction chemotherapy followed by chemoradiotherapy, which have shown good clinical outcomes. However, other options could be considered depending on the assessment of risk/benefits, tumor extension, and patient values and preferences.

MiRNA-128 and MiRNA-142 Regulate Tumorigenesis and EMT in Oral Squamous Cell Carcinoma Through HOXA10

Background

Oral squamous cell carcinoma (OSCC) accounts for more than 90% of all oral cavity cancers, and the 5-year survival rate for OSCC patients remains unsatisfactory. MiRNA-128/miRNA-142 has been reported to work as a tumor suppressor in diverse tumors. However, the biological function of miR-128/miR-142 in OSCC is still unknown.

Methods

The expression of miR-128/miR-142 and homeobox A10 (HOXA10) in OSCC tissues and cells was measured by quantitative real-time polymerase chain reaction (RT-qPCR). The effects of miR-128/miR-142 or HOXA10 on proliferation, migration, invasion and apoptosis were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), transwell and flow cytometry assays, respectively. The expression levels of epithelial–mesenchymal transition (EMT)-associated proteins (E-cadherin, N-cadherin and Vimentin), proliferation-associated protein ki-67 and HOXA10 were detected by Western blot assay. The interaction between HOXA10 and miR-128/miR-142 was predicted by TargetScan, and then confirmed by dual-luciferase reporter assay.

Results

MiR-128/miR-142 was downregulated in OSCC tissues and cells. Overexpression of miR-128/miR-142 inhibited proliferation, migration, invasion and EMT and induced apoptosis in OSCC cells. HOXA10 as the target of miR-128/miR-142 was verified in OSCC cells. Knockdown of HOXA10 also repressed proliferation, migration, invasion and EMT and boosted apoptosis in OSCC cells. Upregulation of miR-128/miR-142 hindered the expression level of HOXA10, while introduction of HOXA10 weakened the effect.

Conclusion

MiR-128/miR-142 suppressed OSCC tumorigenesis and metastasis by targeting HOXA10, providing a new promising therapeutic approach for OSCC patient diagnosis and treatment.

Knockdown of LINC00662 represses AK4 and attenuates radioresistance of oral squamous cell carcinoma

Background

LncRNAs play crucial roles in the development of carcinomas. However, the investigation of LINC00662 in Oral squamous cell carcinoma (OSCC) is still elusive.

Methods

qRT-PCR assay tested the expression levels of LINC00662, hnRNPC and AK4. With exposure to irradiation, CCK-8, colony formation, flow cytometry and western blot experiments, respectively determined the function of LINC00662 in the radiosensitivity of OSCC cells. Then RIP and western blot assays affirmed the interaction between hnRNPC protein and LINC00662 or AK4. Finally, rescue assays validated the regulation mechanism of LINC00662 in the radioresistance of OSCC.

Results

In the present report, LINC00662 was overexpressed in OSCC and its silencing could alleviate radioresistance of OSCC. Furthermore, the interaction between hnRNPC protein and LINC00662 or AK4 was uncovered. Besides, LINC00662 regulated AK4 mRNA stability through binding to hnRNPC protein. To sum up, LINC00662 modulated the radiosensitivity of OSCC cells via hnRNPC-modulated AK4.

Conclusion

The molecular mechanism of the LINC00662/hnRNPC/AK4 axis was elucidated in OSCC, which exhibited a promising therapeutic direction for patients with OSCC.

MiR-4282 inhibits tumor progression through down-regulation of ZBTB2 by targeting LIN28B in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most aggressive type of head and neck cancer with an unsatisfactory 5-year survival rate. MicroRNAs are a group of small noncoding RNAs reported to serve important roles in carcinogenesis, inhibiting certain gene expression via targeting the 3'-untranslated region of messenger RNAs (mRNAs). MiR-4282 has been newly discovered to be a tumor suppressor in colorectal cancer, but it has never been studied in OSCC. The present study aimed to uncover the role of miR-4282 in OSCC. We first confirmed that miR-4282 was downregulated in OSCC and validated its prognostic significance. Through gain-of-function assays, miR-4282 was discovered to inhibit proliferation, migration, and epithelial-to-mesenchymal transition, and induce apoptosis. By mechanistic research, we predicted via bioinformatics tools and confirmed by luciferase reporter and pulldown assays that miR-4282 targeted LIN28B, an RNA-binding protein, which has been reported to regulate RNA stability in cancers. Furthermore, we confirmed the interaction between LIN28B and zinc finger and BTB domain containing 2 (ZBTB2), and validated that miR-4282 regulated mRNA stability of ZBTB2 by inhibiting LIN28B. Rescue assays proved that miR-4282 inhibited tumor progression through LIN28B/ZBTB2 axis. In vivo assays proved that miR-4282 inhibited tumor growth in OSCC. In conclusion, the present study revealed that miR-4282 inhibited tumor progression through downregulation of ZBTB2 by targeting LIN28B in OSCC cells, indicating miR-4282 as a novel biomarker for OSC.

The potential influence of long non-coding RNA PRKG1-AS1 on oral squamous cell carcinoma: A comprehensive study based on bioinformatics and in vitro validation

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the most frequent malignancies in oral cancer. Herein, we aimed to investigate the influence of lncRNA protein kinase cGMP-dependent type I-Antisense RNA 1 (PRKG1-AS1) in OSCC progression.

METHODS

Basing on the data acquired from TCGA database, the expression and prognostic value of PRKG1-AS1 in OSCC patients were assessed. The expression of PRKG1-AS1 in OSCC cells was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell growth was evaluated by Cell Counting Kit-8 (CCK8) and colony-forming assays. Transwell assay was employed to test cell invasion and migration. The protein expression of epithelial-mesenchymal transition (EMT)-related markers was detected by Western blotting.

RESULTS

The consequences displayed that PRKG1-AS1 was highly expressed in OSCC tissues and high expression of PRKG1-AS1 predicted poor outcomes. The expression of PRKG1-AS1 was higher in CAL27, SCC-9, and SCC-4 than that in normal human oral keratinocytes (NHOK). The results of biological experiments showed that deficiency of PRKG1-AS1 suppressed cell growth, invasion, and migration in CAL27 cells, and over-expression of PRKG1-AS1 accelerated cell growth, invasion, and migration in SCC-4 cells. Finally, silencing of PRKG1-AS1 obviously facilitated the protein expression levels of E-cadherin and reduced levels of N-cadherin, Vimentin, and Snail in CAL27 cells whereas over-expression of PRKG1-AS1 led to opposite results in SCC-4 cells.

CONCLUSION

These outcomes indicated that PRKG1-AS1 functioned as a facilitator in OSCC cell growth, migration, and invasion, which all might be achieved by regulating EMT.

Long noncoding RNA OIP5-AS1 promotes the progression of oral squamous cell carcinoma via regulating miR-338-3p/NRP1 axis

Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1), a novel identified long noncoding RNA (lncRNA), has been suggested to serve as oncogene in multiple cancers. However, the functional involvement of OIP5-AS1 in oral squamous cell carcinoma (OSCC) was still unknown. The aims of this study were to investigate the functional role of OIP5-AS1 in OSCC and explore its potential mechanism. We found that OIP5-AS1 was up-regulated in OSCC tissues compared with adjacent non-tumor tissues. Loss-of-function experiments revealed that OIP5-AS1 knockdown significantly inhibited OSCC cell proliferation, migration and invasion in vitro, and retarded tumor growth in vivo. Mechanistically, OIP5-AS1 serves as a competing endogenous RNA of miR-338-3p and modulates the expression of neuropilin1 (NRP1), which has been identified as a downstream target gene of miR-338-3p in OSCC. Moreover, downregulation of miR-338-3p or overexpression of NRP1 partly reversed the inhibitory effect of OIP5-AS1 depletion on cell proliferation, migration and invasion. The current results provide evidences for the role of OIP5-AS1 in promoting OSCC progression by regulating miR-338-3p/NRP1 axis and suggest OIP5-AS1 as a potential therapy target for OSCC.

Long non-coding RNA SNHG20 promotes the tumorigenesis of oral squamous cell carcinoma via targeting miR-197/LIN28 axis

Long non‐coding RNA (lncRNA) has been verified to participate in the tumour regulation, including oral squamous cell carcinoma (OSCC). Nevertheless, the role of lncRNA SNHG20 on OSCC still remains elusive. Here, we investigate the physiopathologic functions of lncRNA SNHG20 in OSCC tumorigenesis and explore its potential mechanism. LncRNA SNHG20 was up‐regulated in OSCC tissue compared with adjacent non‐tumour tissue. Meanwhile, SNHG20 was overexpressed in cancer stem‐like cells. In vitro and in vivo, loss‐of‐function experiments showed that lncRNA SNHG20 knockdown inhibited proliferative ability, mammosphere‐forming ability, ALDH1 expression, stem factors (LIN28, Nanog, Oct4, SOX2) and tumour growth. Bioinformatics and luciferase reporter assay revealed that miR‐197 targeted the 3′‐untranslated regions of SNHG20 and LIN28 by complementary binding. Validation experiments confirmed the associated functions of SNHG20/miR‐197/LIN28 axis on OSCC proliferation and stemness. In summary, our results reveal the important function of SNHG20/miR‐197/LIN28 axis in the oncogenesis and stemness of OSCC, suggesting the vital role of SNHG20 in OSCC tumorigenesis.

Comparative genomic analysis of oral versus laryngeal and pharyngeal cancer

OBJECTIVE

Locally advanced oral squamous cell carcinoma (OSCC) shows lower locoregional control and disease specific survival rates than laryngeal and pharyngeal squamous cell carcinoma (L/P-SCC) after definitive chemoradiotherapy treatment. Despite clinical factors, this can point towards a different tumor biology that could impact chemoradiotherapy response rates. This prompted us to compare the mutational profiles of OSCC with L/P-SCC.

METHODS

We performed target capture DNA sequencing on 111 HPV-negative HNSCC samples (NKI dataset), 55 oral and 56 laryngeal/pharyngeal, and identified somatic point mutations and copy number aberrations. We next expanded our analysis with 276 OSCC and 134 L/P-SCC sample data from The Cancer Genome Atlas (TCGA dataset). We focused our analyses on genes that are frequently mutated in HNSCC.

RESULTS

The mutational profiles of OSCC and L/P-SCC showed many similarities. However, OSCC was significantly enriched for CASP8 (NKI: 15% vs 0%; TCGA: 17% vs 2%) and HRAS (TCGA: 10% vs 1%) mutations. LAMA2 (TCGA: 5% vs 19%) and NSD1 (TCGA: 7% vs 25%) mutations were enriched in L/P-SCC. Overall, we find that OSCC had fewer somatic point mutations and copy number aberrations than L/P-SCC. Interestingly, L/P-SCC scored higher in mutational and genomic scar signatures associated with homologous recombination DNA repair defects.

CONCLUSION

Despite showing a similar mutational profile, our comparative genomic analysis revealed distinctive features in OSCC and L/P-SCC. Some of these genes and cellular processes are likely to affect the cellular response to radiation or cisplatin. Genomic characterizations may guide or enable personalized treatment in the future.