Effects of HPV-16 infection on hypopharyngeal squamous cell carcinoma and FaDu cells

Expression and molecular regulation of non-coding RNAs in HPV-positive head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent malignancy worldwide. Accumulating evidence suggests that persistent HPV infection is closely related to a subset of HNSCC types, and the incidence of human papillomavirus (HPV)-positive HNSCC has been annually increasing in recent decades. Although the carcinogenesis of HPV-positive HNSCC has not been completely elucidated, it has been well confirmed that E6 and E7, the main viral oncoproteins are responsible for the maintenance of malignant transformation, promotion of cell proliferation, and increase in tumor invasion. Moreover, compared with HPV-negative HNSCC, HPV-positive HNSCC shows some special clinical-pathological features, which are possibly related to HPV infection and their specific regulatory mechanisms. Non-coding RNA (ncRNA) is a class of RNA lacking the protein-coding function and playing a critical regulatory role via multiple complex molecular mechanisms. NcRNA is an important regulatory pattern of epigenetic modification, which can exert significant effects on HPV-induced tumorigenesis and progression by deregulating downstream genes. However, the knowledge of ncRNAs is still limited, hence, a better understanding of ncRNAs could provide some insights for exploring the carcinogenesis mechanism and identifying valuable biomarkers in HPV-positive HNSCC. Therefore, in this review, we mainly focused on the expression profile of ncRNAs (including lncRNA, miRNA, and circRNA) and explored their regulatory role in HPV-positive HNSCC, aiming to clarify the regulatory mechanism of ncRNAs and identify valuable biomarkers for HPV-positive HNSCC.

Antitumor effects of valdecoxib on hypopharyngeal squamous carcinoma cells

The antitumoral effects of valdecoxib (Val), an United States Food and Drug Administration-approved anti-inflammatory drug that was withdrawn due to the side effects of increased risk of cardiovascular adverse events, were investigated in hypopharyngeal squamous cell carcinoma cells by performing a cell viability assay, transwell assay, immunofluorescence imaging, and Western blotting. Val markedly inhibited cell viability with an IC50 of 67.3 μM after 48 h of treatment, and also downregulated cell cycle proteins such as Cdks and their regulatory cyclin units. Cell migration and invasion were severely suppressed by inhibiting integrin α4/FAK expression. In addition, Val activated the cell cycle checkpoint CHK2 in response to excessive DNA damage, which led to the activation of caspase-3/9 and induced caspase-dependent apoptosis. Furthermore, the signaling cascades of the PI3K/AKT/mTOR and mitogen-activated protein kinase pathways were significantly inhibited by Val treatment. Taken together, our results indicate that Val can be used for the treatment of hypopharyngeal squamous cell carcinoma.

Human papillomavirus E6 and E7: What remains?

Decades of research on the human papillomavirus oncogenes, E6 and E7, have given us huge amounts of data on their expression, functions and structures. We know much about the very many cellular proteins and pathways that they influence in one way or another. However, much of this information is quite discrete, referring to one activity examined under one condition. It is now time to join the dots to try to understand a larger picture: how, where and when do all these interactions occur... and why? Examining these questions will also show how many of the yet obscure cellular processes work together for cellular and tissue homeostasis in health and disease.

Salivary microRNAs identified by small RNA sequencing as potential predictors of response to intensity-modulated radiotherapy in head and neck cancer patients

PURPOSE

Progress in radiation therapy of head and neck squamous cell carcinomas (HNSCCs) is logically linked to the development of molecular predictors that would help to enhance individually tailored treatment. MicroRNA (miRNA) expression profiles in tumors have repeatedly been tested to optimize the molecular diagnostics of HNSCC. In addition to tumor tissues, miRNAs are stably present in body fluids, including saliva, and can thus be collected non-invasively. The aim of our current study was to evaluate whether salivary miRNAs have potential as response predictors in HNSCC patients treated with intensity modulated radiation therapy (IMRT).

METHODS

In total 48 HNSCC patients treated by definitive IMRT were enrolled in our prospective study. To identify predictive salivary miRNAs, we used small RNA sequencing in 14 saliva samples of HNSCC patients and qRT-PCR validation of selected miRNA candidates in an independent set of 34 patients.

RESULTS

We found that salivary miR-15a-5p and miR-15b-5p exhibited differential levels between patients with and without complete remission (p = 0.025 and p = 0.028, respectively). Subsequent Kaplan-Meier analysis confirmed that patients with higher levels of miR-15a-5p reached a significantly longer locoregional progression-free survival (LPFS) than those with low levels (p = 0.024). Finally, multivariate Cox regression analysis revealed that miR-15a-5p may serve as an independent predictive biomarker of LPFS in HNSCC patients treated with IMRT (HR 0.104; 95% CI 0.004-0.911; p = 0.04).

CONCLUSIONS

We conclude that salivary miR-15a-5p may represent a potential biomarker for individualized treatment decision-making in HNSCC patients.

A 3-miRNA signature predicts survival of patients with hypopharyngeal squamous cell carcinoma after post-operative radiotherapy

Since the prognosis of hypopharyngeal squamous cell carcinoma (HSCC) remains poor, identification of miRNA as a potential prognostic biomarker for HSCC may help improve personalized therapy. In the 2 cohorts with a total of 511 patients with HSCC (discovery: N = 372 and validation: N = 139) after post-operative radiotherapy, we used miRNA microarray and qRT-PCR to screen out the significant miRNAs which might predict survival. Associations of miRNAs and the signature score of these miRNAs with survival were performed by Kaplan-Meier survival analysis and multivariate Cox hazard model. Among 9 candidate, miRNAs, miR-200a-3p, miR-30b-5p, miR-3161, miR-3605-5p, miR-378b and miR-4451 were up-regulated, while miR-200c-3p, miR-429 and miR-4701 were down-regulated after validation. Moreover, the patients with high expression of miR-200a-3p, miR-30b-5p and miR-4451 had significantly worse overall survival (OS) and disease-specific survival (DSS) than did those with low expression (log-rank P < .05). Patients with a high-risk score had significant worse OS and DSS than those with low-risk score. Finally, after adjusting for other important prognostic confounders, patients with high expression of miR-200a-3p, miR-30b-5p and miR-4451 had significantly high risk of overall death and death owing to HSCC and patients with a high-risk score has approximately 2-fold increased risk in overall death and death owing to HSCC compared with those with a low-risk score. These findings indicated that the 3-miRNA-based signature may be a novel independent prognostic biomarker for patients given surgery and post-operative radiotherapy, supporting that these miRNAs may jointly predict survival of HSCC.

miR‑490‑5p regulates the proliferation, migration, invasion and epithelial‑mesenchymal transition of pharyngolaryngeal cancer cells by targeting mitogen‑activated protein kinase kinasekinase 9

MicroRNA (miRNA/miR) has been identified to be a promising tool in treating pharyngolaryngeal cancer. The present study aimed to investigate the role of miR‑490‑5p in the regulation of proliferation, migration, invasion and epithelial‑mesenchymal transition (EMT) of pharyngolaryngeal cancer cells. The data of miR‑490‑5p expression levels of 45 cases were obtained from the People's Hospital of Xinjiang Uygur Autonomous Region, and the prediction of the target of miR‑490‑5p was conducted by bioinformatics and verified using a luciferase assay. Cell viability was determined by cell counting kit‑8. Migration and invasion rates were measured by wound healing test and Transwell apparatus, respectively. Colony formation rate was measured by plate colony formation assay. mRNA and protein levels were determined by quantitative polymerase chain reaction and western blotting, respectively. miR‑490‑5p expression was significantly depressed in primary pharyngolaryngeal cancer tissues and cell lines, leading to an unfavorable prognosis. Evidently, miR‑490‑5p overexpression decreased the cell viabilities of BICR 18 and FaDu cells. Mechanically, miR‑490‑5p could target mitogen‑activated protein kinase kinasekinase 9 (MAP3K9). The overexpression of MAP3K9 could promote cell viability, migration and invasion rates, EMT process and ability of cloning, miR‑490‑5p could target MAP3K9 and further modulate the proliferation, migration, invasion and EMT of pharyngolaryngeal cancer cells. The results of the present study provide a novel entry point to the treatment of pharyngolaryngeal cancer.

miR-15a induces cell apoptosis by targeting BCL2L2 and BCL2 in HPV-positive hypopharyngeal squamous cell carcinoma

Aberrant expression of miR-15a was recently reported in several types of cancers; however, its role in HPV-positive hypopharyngeal squamous cell carcinoma (HSCC) remains obscure. In the present study, we investigated the mechanism by which miR-15a induces HPV-positive HSCC apoptosis. Synthetic miR-15a mimics were transfected into FaDu cells (HPV-negative), and the miR-15a inhibitor was transfected into HPV-positive HSCC cells. miR-15a expression was analyzed by RT-PCR, and BCL2L2 and BCL2 were analyzed by western blotting. The Hochest 33342/propidium iodide (PI) and caspase-3/-9 assays, and Annexin V staining were used to assess the effect of miR-15a on apoptosis. After transfection, overexpression of miR-15a in the FaDu cells was associated with significantly decreased BCL2L2 and BCL2 expression and a significant increase in the apoptosis rate. The opposite results were observed in HPV-positive HSCC, where downregulation of miR-15a suppressed apoptosis. These findings indicate that miR-15a acts as a tumor suppressor in HPV-positive HSCC.