Nuclear survivin promoted by acetylation is associated with the aggressive phenotype of oral squamous cell carcinoma

Targeting histone deacetylases in head and neck squamous cell carcinoma: molecular mechanisms and therapeutic targets

The onerous health and economic burden associated with head and neck squamous cell carcinoma (HNSCC) is a global predicament. Despite the advent of novel surgical techniques and therapeutic protocols, there is an incessant need for efficacious diagnostic and therapeutic targets to monitor the invasion, metastasis and recurrence of HNSCC due to its substantial morbidity and mortality. The differential expression patterns of histone deacetylases (HDACs), a group of enzymes responsible for modifying histones and regulating gene expression, have been demonstrated in neoplastic tissues. However, there is limited knowledge regarding the role of HDACs in HNSCC. Consequently, this review aims to summarize the existing research findings and explore the potential association between HDACs and HNSCC, offering fresh perspectives on therapeutic approaches targeting HDACs that could potentially enhance the efficacy of HNSCC treatment. Additionally, the Cancer Genome Atlas (TCGA) dataset, CPTAC, HPA, OmicShare, GeneMANIA and STRING databases are utilized to provide supplementary evidence on the differential expression of HDACs, their prognostic significance and predicting functions in HNSCC patients.

BIRC5 Gene Polymorphisms Are Associated with a Higher Stage of Local and Regional Disease in Oral and Oropharyngeal Squamous Cell Carcinomas

Oral squamous cell carcinoma (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC) are the most common types of cancers in the head and neck region (HNSCC). Despite very aggressive treatment modalities, the five-year survival rate has not changed for decades and is still around 60%. The search for potential specific biomarkers of aggressiveness or outcome indicators could be of great benefit in improving the treatment of these patients. One of the potential biomarkers is survivin, the protein product of the BIRC5 gene. In this study, we investigated the occurrence of BIRC5 gene polymorphisms in 48 patients with OSCC and OPSCC compared with healthy controls. A total of 18 polymorphisms were found, 11 of which occurred in HNSCC with a minor allele frequency (MAF) of more than 5%. Five polymorphisms (rs3764383, rs9904341, rs2071214, rs2239680, rs2661694) were significantly associated with tumor size, tumor stage, and advanced regional disease, but had no impact on survival.

NRF2/HO-1 axis, BIRC5, and TP53 expression in ESCC and its correlation with clinical pathological characteristics and prognosis

BACKGROUND

Many types of cancer exhibit high nuclear factor erythroid 2-related factor 2 (NRF2), which is effective in resisting drugs and radiation. However, the role of NRF2 gene expression in predicting the prognosis of esophageal squamous cell carcinoma (ESCC) remains unclear.

METHODS

The association between NRF2, heme oxygenase-1 (HO-1), baculovirus IAP repeat 5 (BIRC5), P53 gene expression levels and their relationship to immune-infiltrating cells were assessed using the Cancer Genome Atlas dataset, the Human Protein Atlas and the TISDB database. The expression of NRF2, HO-1, BIRC5, and TP53 in 118 ESCC patients was detected by immunohistochemistry, and the relationship between their expression level and clinicopathological parameters and prognosis was analyzed.

RESULTS

In ESCC, NRF2 overexpression was significantly associated with Han ethnicity, lymph node metastasis, and distant metastasis. HO-1 overexpression was significantly associated with differentiation, advanced clinical staging, lymph node metastasis, nerve invasion, and distant metastasis. BIRC5 overexpression was significantly associated with Han ethnicity and lymph node metastasis. TP53 overexpression was significantly associated with Han ethnicity and T staging. The NRF2/HO-1 axis expression was positively correlated with BIRC5 and TP53. Kaplan-Meier and multivariate Cox regression analysis showed that NRF2, BIRC5, and TP53 genes co-expression was an independent prognostic risk factor. TISIDB dataset analysis showed that immune-infiltrating cells were significantly negatively correlated with NRF2 and BIRC5.

CONCLUSION

NRF2, BIRC5, and TP53 axis gene expressions are predictors of poor prognosis for ESCC. The overexpression of the NRF2/HO-1/BIRC5 axis may not be related to immune-infiltrating cells.

Differential Expression of Potential Biomarkers of Oral Squamous Cell Carcinoma Development

To evaluate molecular epithelial changes, we investigated whether a profile of survivin, cyclin dependent kinase inhibitor 2A (CDKN2A), epidermal growth factor receptor (EGFR), polo like kinase 1 (PLK1), p63, p40 (Δnp63 isoform), cyclin D1 (CCND1) and BCL2 apoptosis regulator (BCL2) proteins could predict malignant transformation. Different tissue segments (tumor adjacent epithelium; dysplasia and tumor) from a total of 109 patients were analyzed by immunohistochemistry. An increased expression of survivin (p < 0.001), PLK1 (p = 0.001), and p63 (p < 0.001) in parallel to reduced immunostaining of p40 (p < 0.001) and BCL2 (p = 0.029) was observed among the tissue segments analyzed. Our study revealed that survivin, PLK1, p63, p40 and BCL2 play a role in oral tumorigenesis and represent promising biomarkers able to recognize mesenchymal phenotype induction in the transition from nonmalignant cells to tumor cells. These results reveals critical interaction between survivin, PLK1, p63, p40 promising proteins during invasive carcinoma development.

Targeting LSD1 suppresses stem cell-like properties and sensitizes head and neck squamous cell carcinoma to PD-1 blockade

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive tumor with poor clinical outcomes due to recurrence, metastasis, and treatment resistance. Cancer stem cells (CSCs), a small population among tumor cells, are proposed to be responsible for tumor initiation, progression, metastasis, drug resistance, and recurrence. Here we show that high LSD1 expression was a predictor of poor prognosis for HNSCC patients. We found that high expression of LSD1 is essential for the maintenance of the CSC properties by regulating Bmi-1 expression. Moreover, tumor LSD1 ablation suppresses CSC-like characteristics in vitro and inhibits tumorigenicity in vivo in immune-deficient xenografts. However, this deletion induces the upregulation of PDL1 levels, which compromises antitumor immunity and reduces antitumor efficacy in an immune-competent mouse model. Functionally, the combination of LSD1 inhibitor and anti-PD-1 monoclonal antibody can overcome tumor immune evasion and greatly inhibit tumor growth, which was associated with reduced Ki-67 level and augmented CD8⁺ T cell infiltration in immunocompetent tumor-bearing mouse models. In summary, these findings provide a novel and promising combined strategy for the treatment of HNSCC using a combination of LSD1 inhibition and PD-1 blockade.

A Novel Prognostic Model for Oral Squamous Cell Carcinoma: The Functions and Prognostic Values of RNA-Binding Proteins

PURPOSE

The biological roles and clinical significance of RNA-binding proteins (RBPs) in oral squamous cell carcinoma (OSCC) are not fully understood. We investigated the prognostic value of RBPs in OSCC using several bioinformatic strategies.

MATERIALS AND METHODS

OSCC data were obtained from a public online database, the Limma R package was used to identify differentially expressed RBPs, and functional enrichment analysis was performed to elucidate the biological functions of the above RBPs in OSCC. We performed protein-protein interaction (PPI) network and Cox regression analyses to extract prognosis-related hub RBPs. Next, we established and validated a prognostic model based on the hub RBPs using Cox regression and risk score analyses.

RESULTS

We found that the differentially expressed RBPs were closely related to the defense response to viruses and multiple RNA processes. We identified 10 prognosis-related hub RBPs (ZC3H12D, OAS2, INTS10, ACO1, PCBP4, RNASE3, PTGES3L-AARSD1, RNASE13, DDX4, and PCF11) and effectively predicted the overall survival of OSCC patients. The area under the receiver operating characteristic (ROC) curve (AUC) of the risk score model was 0.781, suggesting that our model exhibited excellent prognostic performance. Finally, we built a nomogram integrating the 10 RBPs. The internal validation cohort results showed a reliable predictive capability of the nomogram for OSCC.

CONCLUSION

We established a novel 10-RBP-based model for OSCC that could enable precise individual treatment and follow-up management strategies in the future.

Targeting Stress-Response Pathways and Therapeutic Resistance in Head and Neck Cancer

Head and neck cancer is the sixth leading cancer worldwide; head and neck squamous cell carcinoma (HNSCC) accounts for more than 90% of incident cases. In the US, cases of HNSCC associated with human papillomavirus (HPV) have been growing in proportion amongst a younger demographic with superior outcomes to the same treatments, relative to cases associated with tobacco. Yet failures to improve the long-term prognosis of advanced HNSCC over the last three decades persist in part due to intrinsic and acquired mechanisms of resistance. Deregulation of the pathways to respond to stress, such as apoptosis and autophagy, often contributes to drug resistance and tumor progression. Here we review the stress-response pathways in drug response and resistance in HNSCC to explore strategies to overcome these resistance mechanisms. We focus on the mechanisms of resistance to current standard cares, such as chemotherapy (i.e., cisplatin), radiation, and cetuximab. Then, we discuss the strategies to overcome these resistances, including novel combinations and immunotherapy.

Survivin Expression in Metastatic and Nonmetastatic Oral Squamous Cell Carcinoma: A Comparative Study

Aim:

Survivin is a multifunctional protein chiefly involved in apoptosis and cell cycle regulation. Increased expression of survivin in tumors and fetal tissue determines its antiapoptotic activity. The aim of the study is to identify the immunoexpression of survivin in metastatic and nonmetastatic oral squamous cell carcinoma (OSCC) and also to evaluate and compare the expression of survivin in metastatic and nonmetastatic OSCC of buccal mucosa.

Materials and Methods:

In total, 40 histopathologically proven cases of OSCC, including 20 metastatic and 20 nonmetastatic cases, are selected. Among the 20 metastatic and nonmetastatic cases, 10 well-differentiated and 10 moderately differentiated squamous cell carcinoma cases were included and were subjected to immunohistochemical staining for survivin expression. The results were analyzed by SPSS version 11.5 using chi-square test.

Results:

The expression of survivin in metastatic and nonmetastatic tumors is 15%–70% and 15%–60%, respectively. When comparing the cases of moderately differentiated squamous cell carcinoma in metastatic and nonmetastatic tumors, 70% cases show moderate staining intensity.

Conclusion:

The survivin expression was comparatively high in metastatic OSCC. Also based on the aforementioned results, survivin expression was high in increasing grades of OSCC.

EREG-driven oncogenesis of Head and Neck Squamous Cell Carcinoma exhibits higher sensitivity to Erlotinib therapy

Rationale: The oncogenesis of head and neck squamous cell carcinoma (HNSCC) is believed to result from oncogene activation and tumor suppressor inactivation. Here, we identified a new oncogenic role for the EREG gene in HNSCC. Methods: The TCGA database and immunohistochemistry assay were used to analyze expression of EREG in HNSCC tissues. Immunoblotting was performed to identify the EGFR-mediated pathways altered by EREG. The role of EREG in oncogenesis was investigated in vivo and in vitro. Results: Upregulated EREG expression predicted a poor prognosis and triggered HNSCC oncogenic transformation by activating the epidermal growth factor receptor (EGFR) signaling pathway. We also demonstrated the direct association of EREG with EGFR and that this binding required EGFR domains I and III and the N57 residue of EREG. Moreover, EREG overexpression was shown to promote HNSCC oncogenesis by inducing C-Myc expression, and the pharmacological inhibition of C-Myc rescued EREG-promoted HNSCC oncogenesis. Unlike other EGFR ligands, EREG could mimic EGFR mutations by sustaining the activation of the EGFR-Erk pathway, and high EREG expression was positively associated with the response to treatment with the EGFR inhibitor erlotinib. Furthermore, knockdown of EREG decreased sensitivity to erlotinib treatment in vitro and in vivo. Conclusions: These results identify the EREG-EGFR-C-Myc pathway as a crucial axis that drives HNSCC oncogenesis and show that EREG expression could be a predictive functional marker of sensitivity to erlotinib therapy in HNSCC.

Down-regulation and nuclear localization of survivin by sodium butyrate induces caspase-dependent apoptosis in human oral mucoepidermoid carcinoma

OBJECTIVE

Sodium butyrate (NaBu) is a histone deacetylase inhibitor that possesses an apoptotic ability. However, the molecular mechanism by which NaBu induces apoptosis in human oral mucoepidermoid carcinoma (MEC), a type of salivary gland tumor, remains unclear.

MATERIALS AND METHODS

The anticancer effects of NaBu and its related molecular mechanisms were determined by trypan blue exclusion assay, 4'-6-diamidino-2-phenylindole staining, live/dead assay, human apoptosis array, RT-PCR, western blotting, immunocytochemistry, preparation of nuclear fractions, and nude mice tumor xenograft.

RESULTS

In this study, we found that NaBu inhibited growth and induced apoptosis in the human oral MEC cell lines MC3 and YD15 with acetylation of histone proteins H2A and H3. NaBu apparently down-regulated survivin protein, as evidenced by the results of the human apoptosis antibody array, and modulated it at the post-translational process. Interestingly, NaBu caused nuclear translocation of survivin protein in both cell lines. NaBu also resulted in decreased expression levels of Bcl-xL mRNA and protein, leading to induction of caspase-dependent apoptosis in human oral MEC cell lines. In addition, NaBu administration inhibited tumor growth in vivo at a dosage of 500 mg/kg/day, but it did not cause any hepatic or renal toxicity.

CONCLUSION

This study provides new insights into the molecular mechanism of apoptotic actions by NaBu in human oral MEC and the basis of its clinical application for the treatment of human oral MEC.

High nuclear Survivin expression as a poor prognostic marker in pancreatic ductal adenocarcinoma

BACKGROUND

Survivin, one of the key regulators of mitosis and apoptosis, has long been well recognized to play important biological roles in many neoplasms, including pancreatic ductal adenocarcinoma (PDAC). However, its prognostic value in PDAC remains controversial.

PATIENTS AND METHODS

Nuclear expression of Survivin was detected, using tissue microarray-based immunohistochemistry, in paired-tumor and nontumor samples from 306 patients with radically resected PDAC. The staining H scores were further correlated with clinicopathologic features and disease-specific survival (DSS).

RESULTS

Nuclear Survivin expression was much higher in tumor than in nontumor tissues (P < 0.001). No significant association between tumoral Survivin expression and clinicopathologic variables was found. For prognosis, high Survivin expression was associated with shortened DSS in all eligible patients and four subgroups, that is, male and nondiabetic patients as well as those with head-located and G1-2 tumors, shown by univariate analyses. In addition, a statistically marginal significance was revealed in eight subgroups. For the entire cohort and two subgroups, nuclear Survivin expression was also multivariate identified as an independent predictor for DSS. For patients with G1-2 tumors, it was the single prognostic marker.

CONCLUSION

Our data suggest an association between high nuclear Survivin expression and poor prognosis in PDAC. However, further confirmation might be necessary.

Integrative Histologic and Bioinformatics Analysis of BIRC5/Survivin Expression in Oral Squamous Cell Carcinoma

Survivin is a well-known protein involved in the inhibition of apoptosis in many different cancer types. The aim of this study was to perform an integrated bioinformatic and histologic analysis in order to study the expression and prognostic role of Survivin and its related gene BIRC5 in oral cancer. Publicly available databases were accessed via Gene Expression Omnibus and Oncomine, in addition raw data from The Cancer Genome Atlas (TCGA) were also obtained in order to analyze the rate of gene mutation, expression and methylation in patients with oral squamous cells carcinoma (OSCC). Immunohistochemistry (IHC) was also performed in order to evaluate the nuclear and cytoplasmic expression of Survivin and their correlation with cell proliferation in samples from OSCC patients. Results of this study revealed that Survivin is rarely mutated in OSCC samples and upregulated when compared to non-cancerous tissue. A negative correlation between the methylation of the island cg25986496 and BIRC5 mRNA expression was detected from TCGA data. IHC staining revealed that cytoplasmic (and not nuclear) expression of Survivin is associated with poor overall survival in OSCC patients, while the nuclear expression correlates with higher proliferation rate. In addition, data from TCGA database revealed that BIRC5 gene expression is an independent prognostic factor for OSCC patients.

Hallmarks of Cancer-Related Newly Prognostic Factors of Oral Squamous Cell Carcinoma

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the sixth leading malignancy worldwide. OSCC is an aggressive tumor and its prognosis has exhibited little improvement in the last three decades. Comprehensive elucidation of OSCC's molecular mechanism is imperative for early detection and treatment, improving patient survival. Based on broadly accepted notions, OSCC arises from multiple genetic alterations caused by chronic exposure to carcinogens. In 2011, research revealed 10 key alterations fundamental to cancer cell development: sustaining proliferative signaling, evading growth suppressors, avoiding immune destruction, activating invasion and metastasis, tumor-promoting inflammation, enabling replicative immortality, inducing angiogenesis, genome instability and mutation, resisting cell death, and deregulating energetics. This review describes molecular pathological findings on conventional and novel hallmarks of OSCC prognostic factors. In addition, the review summarizes the functions and roles of several molecules as novel OSCC prognosticators.

EGFR activation induced Snail-dependent EMT and myc-dependent PD-L1 in human salivary adenoid cystic carcinoma cells

Epithelial-to-mesenchymal transition (EMT) confers cancer cells the ability of invasion and metastasis. However, how does EMT contribute to evasion of immune surveillance is unclear, especially in salivary adenoid cystic carcinoma (SACC). In this study, we investigated the molecular link between EGF-induced EMT and the immune checkpoint ligand programmed death-ligand 1 (PD-L1) by immunoprecipitation (IP) and Westernblot analysis. Cell migration and invasion activity was assayed by transwell assay. Immunohistochemical (IHC) staining analysis was performed for measurement of EMT markers and PD-L1 expression levels in tumor tissues. We found that EGF-induced EGFR activation stabilized Snail expression and induced EMT in SACC. Interestingly, EGFR activation induced simultaneously both EMT and PD-L1 in SACC. Importantly, knockdown of Snail greatly suppressed EGF-induced EMT, but not EGF-induced PD-L1 expression; whereas knockdown of c-Myc strongly repressed PD-L1 expression, but not snail expression and EMT. The molecular link is strongly supported by robust correlations between the EMT markers and PD-L1 expression in human cancer samples.These results suggest that EGFR activated EMT and PD-L1 via two distinct mechanisms. EGFR activation induced EMT and PD-L1 expression in SACC. Snail is required for EGF-induced EMT, but not PD-L1 expression; whereas c-Myc is required for EGFR-mediated PD-L1 upregulation but not EMT. Thus, targeting activated EGFR may inhibit both EMT and PD-L1, which may potentiate the therapeutic effect of PD-L1-based immunotherapy, especially in the malignant subgroups of SACC patients with activated EGFR.